Impact of PACAP and PAC1 Receptor Deficiency on the Neurochemical and Behavioral Effects of Acute and Chronic Restraint Stress in Male C57BL/6 Mice

PubMed Central

Mustafa, Tomris; Jiang, Sunny Zhihong; Eiden, Adrian M.; Weihe, Eberhard; Thistlethwaite, Ian; Eiden, Lee E.

2016-01-01

Acute restraint stress (ARS) for 3 hours causes CORT elevation in venous blood, which is accompanied by Fos up-regulation in the paraventricular nucleus (PVN) of male C57BL/6 mice. CORT elevation by ARS is attenuated in PACAP-deficient mice, but unaffected in PAC1-deficient mice. Correspondingly, Fos up-regulation by ARS is greatly attenuated in PACAP-deficient mice, but much less so in PAC1-deficient animals. We noted that both PACAP- and PAC1-deficiency greatly attenuate CORT elevation after ARS when CORT measurements are performed on trunk blood following euthanasia by abrupt cervical separation: this latter observation is of critical importance in assessing the role of PACAP neurotransmission in ARS, based on previous reports in which serum CORT was sampled from trunk blood. Seven days of chronic restraint stress (CRS) induces non-habituating CORT elevation, and weight loss consequent to hypophagia, in wild-type male C57BL/6 mice. Both CORT elevation and weight loss following seven day CRS are severely blunted in PACAP-deficient mice, but only slightly in PAC1 deficient mice. However, longer periods of daily restraint (14–21 days) resulted in sustained weight loss and elevated CORT in wild-type mice, and these effects of long-term chronic stress were attenuated or abolished in both PACAP- and PAC1-deficient mice. We conclude that while a PACAP receptor in addition to PAC1 may mediate some of the PACAP-dependent central effects of acute restraint stress and short-term (<7 days) chronic restraint stress on the HPA axis, the PAC1 receptor plays a prominent role in mediating PACAP-dependent HPA axis activation, and hypophagia, during long-term (>7 days) chronic restraint stress. PMID:25853791

CHRONIC EXPOSURE TO ARSENITE IN DRINKING WATER IMPAIRS GLUCOSE TOLERANCE IN C57BL/6 MICE

EPA Science Inventory

Chronic exposures to inorganic arsenic (iAs) have been associated with increased prevalence of type 2 diabetes mellitus. This study examines in vivo diabetogenic effects of iAs in an animal model. Here, weanling male C57BL/6 mice received deionized water containing iAs(III) (25 ...

A model of chronic diabetic polyneuropathy: benefits from intranasal insulin are modified by sex and RAGE deletion

PubMed Central

de la Hoz, Cristiane L.; Cheng, Chu; Fernyhough, Paul

2017-01-01

Human diabetic polyneuropathy (DPN) is a progressive complication of chronic diabetes mellitus. Preliminary evidence has suggested that intranasal insulin, in doses insufficient to alter hyperglycemia, suppresses the development of DPN. In this work we confirm this finding, but demonstrate that its impact is modified by sex and deletion of RAGE, the receptor for advanced glycosylation end products. We serially evaluated experimental DPN in male and female wild-type mice and male RAGE null (RN) mice, each with nondiabetic controls, during 16 wk of diabetes, the final 8 wk including groups given intranasal insulin. Age-matched nondiabetic female mice had higher motor and sensory conduction velocities than their male counterparts and had lesser conduction slowing from chronic diabetes. Intranasal insulin improved slowing in both sexes. In male RN mice, there was less conduction slowing with chronic diabetes, and intranasal insulin provided limited benefits. Rotarod testing and hindpaw grip power offered less consistent impacts. Mechanical sensitivity and thermal sensitivity were respectively but disparately changed and improved with insulin in wild-type female and male mice but not RN male mice. These studies confirm that intranasal insulin improves indexes of experimental DPN but indicates that females with DPN may differ in their underlying phenotype. RN mice had partial but incomplete protection from underlying DPN and lesser impacts from insulin. We also identify an important role for sex in the development of DPN and report evidence that insulin and AGE-RAGE pathways in its pathogenesis may overlap. PMID:28223295

Chronic Trichuris muris infection causes neoplastic change in the intestine and exacerbates tumour formation in APC min/+ mice

PubMed Central

Cliffe, Laura J.; Bancroft, Alison J.; Forman, Simon P.; Thompson, Seona; Booth, Cath

2017-01-01

Incidences of infection-related cancers are on the rise in developing countries where the prevalence of intestinal nematode worm infections are also high. Trichuris muris (T. muris) is a murine gut-dwelling nematode that is the direct model for human T. trichiura, one of the major soil-transmitted helminth infections of humans. In order to assess whether chronic infection with T. muris does indeed influence the development of cancer hallmarks, both wild type mice and colon cancer model (APC min/+) mice were infected with this parasite. Parasite infection in wild type mice led to the development of neoplastic change similar to that seen in mice that had been treated with the carcinogen azoxymethane. Additionally, both chronic and acute infection in the APCmin/+ mice led to an enhanced tumour development that was distinct to the site of infection suggesting systemic control. By blocking the parasite induced T regulatory response in these mice, the increase in the number of tumours following infection was abrogated. Thus T. muris infection alone causes an increase in gut pathologies that are known to be markers of cancer but also increases the incidence of tumour formation in a colon cancer model. The influence of parasitic worm infection on the development of cancer may therefore be significant. PMID:28650985

Chronic Trichuris muris infection causes neoplastic change in the intestine and exacerbates tumour formation in APC min/+ mice.

PubMed

Hayes, Kelly S; Cliffe, Laura J; Bancroft, Alison J; Forman, Simon P; Thompson, Seona; Booth, Cath; Grencis, Richard K

2017-06-01

Incidences of infection-related cancers are on the rise in developing countries where the prevalence of intestinal nematode worm infections are also high. Trichuris muris (T. muris) is a murine gut-dwelling nematode that is the direct model for human T. trichiura, one of the major soil-transmitted helminth infections of humans. In order to assess whether chronic infection with T. muris does indeed influence the development of cancer hallmarks, both wild type mice and colon cancer model (APC min/+) mice were infected with this parasite. Parasite infection in wild type mice led to the development of neoplastic change similar to that seen in mice that had been treated with the carcinogen azoxymethane. Additionally, both chronic and acute infection in the APCmin/+ mice led to an enhanced tumour development that was distinct to the site of infection suggesting systemic control. By blocking the parasite induced T regulatory response in these mice, the increase in the number of tumours following infection was abrogated. Thus T. muris infection alone causes an increase in gut pathologies that are known to be markers of cancer but also increases the incidence of tumour formation in a colon cancer model. The influence of parasitic worm infection on the development of cancer may therefore be significant.

Adrenocortical and behavioural response to chronic restraint stress in neurokinin-1 receptor knockout mice.

PubMed

Delgado-Morales, Raúl; del Río, Eva; Gómez-Román, Almudena; Bisagno, Verónica; Nadal, Roser; de Felipe, Carmen; Armario, Antonio

2012-02-01

Brain substance P and its receptor (neurokinin-1, NK1) have a widespread brain distribution and are involved in an important number of behavioural and physiological responses to emotional stimuli. However, the role of NK1 receptors in the consequences of exposure to chronic stress has not been explored. The present study focused on the role of these receptors in the hypothalamic-pituitary-adrenal (HPA) response to daily repeated restraint stress (evaluated by plasma corticosterone levels), as well as on the effect of this procedure on anxiety-like behaviour, spatial learning and memory in the Morris water maze (MWM), a hippocampus-dependent task. Adult null mutant NK1-/- mice, with a C57BL/6J background, and the corresponding wild-type mice showed similar resting corticosterone levels and, also, did not differ in corticosterone response to a first restraint. Nevertheless, adaptation to the repeated stressor was faster in NK1-/- mice. Chronic restraint modestly increased anxiety-like behaviour in the light-dark test, irrespective of genotype. Throughout the days of the MWM trials, NK1-/- mice showed a similar learning rate to that of wild-type mice, but had lower levels of thigmotaxis and showed a better retention in the probe trial. Chronic restraint stress did not affect these variables in either genotype. These results indicate that deletion of the NK1 receptor does not alter behavioural susceptibility to chronic repeated stress in mice, but accelerates adaptation of the HPA axis. In addition, deletion may result in lower levels of thigmotaxis and improved short-term spatial memory, perhaps reflecting a better learning strategy in the MWM. Copyright © 2011 Elsevier Inc. All rights reserved.

Midlife stress alters memory and mood-related behaviors in old age: Role of locally activated glucocorticoids.

PubMed

Wheelan, Nicola; Kenyon, Christopher J; Harris, Anjanette P; Cairns, Carolynn; Al Dujaili, Emad; Seckl, Jonathan R; Yau, Joyce L W

2018-03-01

Chronic exposure to stress during midlife associates with subsequent age-related cognitive decline and may increase the vulnerability to develop psychiatric conditions. Increased hypothalamic-pituitary-adrenal (HPA) axis activity has been implicated in pathogenesis though any causative role for glucocorticoids is unestablished. This study investigated the contribution of local glucocorticoid regeneration by the intracellular enzyme 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1), in persisting midlife stress-induced behavioral effects in mice. Middle-aged (10 months old) 11β-HSD1-deficient mice and wild-type congenic controls were randomly assigned to 28 days of chronic unpredictable stress or left undisturbed (non-stressed). All mice underwent behavioral testing at the end of the stress/non-stress period and again 6-7 months later. Chronic stress impaired spatial memory in middle-aged wild-type mice. The effects, involving a wide spectrum of behavioral modalities, persisted for 6-7 months after cessation of stress into early senescence. Enduring effects after midlife stress included impaired spatial memory, enhanced contextual fear memory, impaired fear extinction, heightened anxiety, depressive-like behavior, as well as reduced hippocampal glucocorticoid receptor mRNA expression. In contrast, 11β-HSD1 deficient mice resisted both immediate and enduring effects of chronic stress, despite similar stress-induced increases in systemic glucocorticoid activity during midlife stress. In conclusion, chronic stress in midlife exerts persisting effects leading to cognitive and affective dysfunction in old age via mechanisms that depend, at least in part, on brain glucocorticoids generated locally by 11β-HSD1. This finding supports selective 11β-HSD1 inhibition as a novel therapeutic target to ameliorate the long-term consequences of stress-related psychiatric disorders in midlife. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

Control of acute, chronic, and constitutive hyperammonemia by wild-type and genetically engineered Lactobacillus plantarum in rodents.

PubMed

Nicaise, Charles; Prozzi, Deborah; Viaene, Eric; Moreno, Christophe; Gustot, Thierry; Quertinmont, Eric; Demetter, Pieter; Suain, Valérie; Goffin, Philippe; Devière, Jacques; Hols, Pascal

2008-10-01

Hyperammonemia is a common complication of acute and chronic liver diseases. Often accompanied with side effects, therapeutic interventions such as antibiotics or lactulose are generally targeted to decrease the intestinal production and absorption of ammonia. In this study, we aimed to modulate hyperammonemia in three rodent models by administration of wild-type Lactobacillus plantarum, a genetically engineered ammonia hyperconsuming strain, and a strain deficient for the ammonia transporter. Wild-type and metabolically engineered L. plantarum strains were administered in ornithine transcarbamoylase-deficient Sparse-fur mice, a model of constitutive hyperammonemia, in a carbon tetrachloride rat model of chronic liver insufficiency and in a thioacetamide-induced acute liver failure mice model. Constitutive hyperammonemia in Sparse-fur mice and hyperammonemia in a rat model of chronic hepatic insufficiency were efficiently decreased by Lactobacillus administration. In a murine thioacetamide-induced model of acute liver failure, administration of probiotics significantly increased survival and decreased blood and fecal ammonia. The ammonia hyperconsuming strain exhibited a beneficial effect at a lower dose than its wild-type counterpart. Improved survival in the acute liver failure mice model was associated with lower blood ammonia levels but also with a decrease of astrocyte swelling in the brain cortex. Modulation of ammonia was abolished after administration of the strain deficient in the ammonium transporter. Intestinal pH was clearly lowered for all strains and no changes in gut flora were observed. Hyperammonemia in constitutive model or after acute or chronic induced liver failure can be controlled by the administration of L. plantarum with a significant effect on survival. The mechanism involved in this ammonia decrease implicates direct ammonia consumption in the gut.

Antagonism of scavenger receptor CD36 by 5A peptide prevents chronic kidney disease progression in mice independent of blood pressure regulation

PubMed Central

Souza, Ana Carolina P.; Bocharov, Alexander V.; Baranova, Irina; Vishnyakova, Tatyana; Huang, Yuning G.; Wilkins, Kenneth J.; Hu, Xuzhen; Street, Jonathan M.; Alvarez-Prats, Alejandro; Mullick, Adam E.; Patterson, Amy P.; Remaley, Alan; Eggerman, Thomas L.; Yuen, Peter S.T.; Star, Robert A.

2016-01-01

Scavenger receptor CD36 participates in lipid metabolism and inflammatory pathways important for cardiovascular disease and chronic kidney disease (CKD). Few pharmacological agents are available to slow the progression of CKD. However, apolipoprotein AI-mimetic peptide 5A antagonizes CD36 in vitro. To test the efficacy of 5A, and to test the role of CD36 during CKD, we compared wild type to CD36 knockout mice and wild type mice treated with 5A, in a progressive CKD model that resembles human disease. Knockout and 5A-treated wild type mice were protected from CKD progression without changes in blood pressure and had reductions in cardiovascular risk surrogate markers that are associated with CKD. Treatment with 5A did not further protect CD36 knockout mice from CKD progression, implicating CD36 as its main site of action. In a separate model of kidney fibrosis, 5A-treated wild type mice had less macrophage infiltration and interstitial fibrosis. Peptide 5A exerted anti-inflammatory effects in the kidney and decreases renal expression of inflammasome genes. Thus, CD36 is a new therapeutic target for CKD and its associated cardiovascular risk factors. Peptide 5A may be a promising new agent to slow CKD progression. PMID:26994575

Pulmonary Hypertension in Wild Type Mice and Animals with Genetic Deficit in KCa2.3 and KCa3.1 Channels

PubMed Central

Sadda, Veeranjaneyulu; Nielsen, Gorm; Hedegaard, Elise Røge; Mogensen, Susie; Köhler, Ralf; Simonsen, Ulf

2014-01-01

Objective In vascular biology, endothelial KCa2.3 and KCa3.1 channels contribute to arterial blood pressure regulation by producing membrane hyperpolarization and smooth muscle relaxation. The role of KCa2.3 and KCa3.1 channels in the pulmonary circulation is not fully established. Using mice with genetically encoded deficit of KCa2.3 and KCa3.1 channels, this study investigated the effect of loss of the channels in hypoxia-induced pulmonary hypertension. Approach and Result Male wild type and KCa3.1−/−/KCa2.3T/T(+DOX) mice were exposed to chronic hypoxia for four weeks to induce pulmonary hypertension. The degree of pulmonary hypertension was evaluated by right ventricular pressure and assessment of right ventricular hypertrophy. Segments of pulmonary arteries were mounted in a wire myograph for functional studies and morphometric studies were performed on lung sections. Chronic hypoxia induced pulmonary hypertension, right ventricular hypertrophy, increased lung weight, and increased hematocrit levels in either genotype. The KCa3.1−/−/KCa2.3T/T(+DOX) mice developed structural alterations in the heart with increased right ventricular wall thickness as well as in pulmonary vessels with increased lumen size in partially- and fully-muscularized vessels and decreased wall area, not seen in wild type mice. Exposure to chronic hypoxia up-regulated the gene expression of the KCa2.3 channel by twofold in wild type mice and increased by 2.5-fold the relaxation evoked by the KCa2.3 and KCa3.1 channel activator NS309, whereas the acetylcholine-induced relaxation - sensitive to the combination of KCa2.3 and KCa3.1 channel blockers, apamin and charybdotoxin - was reduced by 2.5-fold in chronic hypoxic mice of either genotype. Conclusion Despite the deficits of the KCa2.3 and KCa3.1 channels failed to change hypoxia-induced pulmonary hypertension, the up-regulation of KCa2.3-gene expression and increased NS309-induced relaxation in wild-type mice point to a novel mechanism to counteract pulmonary hypertension and to a potential therapeutic utility of KCa2.3/KCa3.1 activators for the treatment of pulmonary hypertension. PMID:24858807

Analysis of Kalirin-7 Knockout Mice Reveals Different Effects in Female Mice

PubMed Central

Mazzone, Christopher M.; Larese, Taylor P.; Kiraly, Drew D.; Eipper, Betty A.

2012-01-01

Estradiol treatment of ovariectomized rodents is known to affect the morphology of dendritic spines and produce behavioral and cognitive effects. Kalirin-7 (Kal7), a postsynaptic density (PSD)-localized Rho-guanine nucleotide exchange factor, is important for dendritic spine formation and stability. Male Kal7 knockout [Kal7(KO)] mice exhibit a number of abnormal behavioral and biochemical phenotypes. Given that chronic 17β-estradiol (E2) replacement of ovariectomized rats enhanced Kal7 expression in the hippocampus and primary hippocampal cultures, we assessed the behavioral and biochemical effects of chronic E2 treatment of ovariectomized female wild-type and Kal7(KO) mice. Both intact and ovariectomized Kal7(KO) female mice exhibited decreased anxiety-like behavior compared with the corresponding wild type in the elevated zero maze and were unaffected by E2 treatment. Chronic E2 decreased locomotor activity in the open field and enhanced performance in a passive-avoidance fear conditioning task, which were both unaffected by genotype. Kal7(KO) female mice engaged in significantly more object exploration, both familiar and novel, than did wild-type females. E2 enhanced the acute locomotor response to cocaine, with no significant effect of genotype. Similar to Kal7(KO) males, Kal7(KO) females had decreased levels of N-methyl-d-aspartate receptor 2B in hippocampal PSD fractions with no effect of E2 treatment. The differing behavioral effects of Kal7 ablation in female and male mice may offer insight into the molecular underpinnings of these differences. PMID:22989522

Period 2 gene deletion abolishes β-endorphin neuronal response to ethanol

PubMed Central

Agapito, Maria; Mian, Nadia; Boyadjieva, Nadka I.; Sarkar, Dipak K.

2010-01-01

Background Ethanol exposure during early life has been shown to permanently alter the circadian expression of clock regulatory genes and the β-endorphin precursor proopiomelanocortin (POMC) gene in the hypothalamus. Ethanol also alters the stress- and immune-regulatory functions of β-endorphin neurons in laboratory rodents. Our aim was to determine whether the circadian clock regulatory Per2 gene modulates the action of ethanol on β-endorphin neurons in mice. Methods Per2 mutant (mPer2Brdml) and wild type (C57BL/6J) mice were used to determine the effect of Per2 mutation on ethanol-regulated β-endorphin neuronal activity during neonatal period using an in vitro mediobasal hypothalamic (MBH) cell culture model and an in vivo milk formula feeding animal model. The β-endorphin neuronal activity following acute and chronic ethanol treatments, was evaluated by measuring the peptide released from cultured cells or peptide levels in the MBH tissues, using enzyme-linked immunosorbent assay (ELISA). Results Per2 mutant mice showed a higher basal level of β-endorphin release from cultured MBH cells and a moderate increase in the peptide content in the MBH in comparison to control mice. However, unlike wild type mice, Per2 mutant mice showed no stimulatory or inhibitory β-endorphin secretory responses to acute and chronic ethanol challenges in vitro. Furthermore, Per2 mutant mice, but not wild type mice, failed to show the stimulatory and inhibitory responses of MBH β-endorphin levels to acute and chronic ethanol challenges in vivo. Conclusions These results suggest for the first time that the Per2 gene may be critically involved in regulating β-endorphin neuronal function. Furthermore, the data revealed an involvement of the Per2 gene in regulating β-endorphin neuronal responses to ethanol. PMID:20586752

Chronic mild stress impairs latent inhibition and induces region-specific neural activation in CHL1-deficient mice, a mouse model of schizophrenia.

PubMed

Buhusi, Mona; Obray, Daniel; Guercio, Bret; Bartlett, Mitchell J; Buhusi, Catalin V

2017-08-30

Schizophrenia is a neurodevelopmental disorder characterized by abnormal processing of information and attentional deficits. Schizophrenia has a high genetic component but is precipitated by environmental factors, as proposed by the 'two-hit' theory of schizophrenia. Here we compared latent inhibition as a measure of learning and attention, in CHL1-deficient mice, an animal model of schizophrenia, and their wild-type littermates, under no-stress and chronic mild stress conditions. All unstressed mice as well as the stressed wild-type mice showed latent inhibition. In contrast, CHL1-deficient mice did not show latent inhibition after exposure to chronic stress. Differences in neuronal activation (c-Fos-positive cell counts) were noted in brain regions associated with latent inhibition: Neuronal activation in the prelimbic/infralimbic cortices and the nucleus accumbens shell was affected solely by stress. Neuronal activation in basolateral amygdala and ventral hippocampus was affected independently by stress and genotype. Most importantly, neural activation in nucleus accumbens core was affected by the interaction between stress and genotype. These results provide strong support for a 'two-hit' (genes x environment) effect on latent inhibition in CHL1-deficient mice, and identify CHL1-deficient mice as a model of schizophrenia-like learning and attention impairments. Copyright © 2017 Elsevier B.V. All rights reserved.

Chronic exposure to low frequency noise at moderate levels causes impaired balance in mice.

PubMed

Tamura, Haruka; Ohgami, Nobutaka; Yajima, Ichiro; Iida, Machiko; Ohgami, Kyoko; Fujii, Noriko; Itabe, Hiroyuki; Kusudo, Tastuya; Yamashita, Hitoshi; Kato, Masashi

2012-01-01

We are routinely exposed to low frequency noise (LFN; below 0.5 kHz) at moderate levels of 60-70 dB sound pressure level (SPL) generated from various sources in occupational and daily environments. LFN has been reported to affect balance in humans. However, there is limited information about the influence of chronic exposure to LFN at moderate levels for balance. In this study, we investigated whether chronic exposure to LFN at a moderate level of 70 dB SPL affects the vestibule, which is one of the organs responsible for balance in mice. Wild-type ICR mice were exposed for 1 month to LFN (0.1 kHz) and high frequency noise (HFN; 16 kHz) at 70 dB SPL at a distance of approximately 10-20 cm. Behavior analyses including rotarod, beam-crossing and footprint analyses showed impairments of balance in LFN-exposed mice but not in non-exposed mice or HFN-exposed mice. Immunohistochemical analysis showed a decreased number of vestibular hair cells and increased levels of oxidative stress in LFN-exposed mice compared to those in non-exposed mice. Our results suggest that chronic exposure to LFN at moderate levels causes impaired balance involving morphological impairments of the vestibule with enhanced levels of oxidative stress. Thus, the results of this study indicate the importance of considering the risk of chronic exposure to LFN at a moderate level for imbalance.

Chronic Exposure to Low Frequency Noise at Moderate Levels Causes Impaired Balance in Mice

PubMed Central

Tamura, Haruka; Ohgami, Nobutaka; Yajima, Ichiro; Iida, Machiko; Ohgami, Kyoko; Fujii, Noriko; Itabe, Hiroyuki; Kusudo, Tastuya; Yamashita, Hitoshi; Kato, Masashi

2012-01-01

We are routinely exposed to low frequency noise (LFN; below 0.5 kHz) at moderate levels of 60–70 dB sound pressure level (SPL) generated from various sources in occupational and daily environments. LFN has been reported to affect balance in humans. However, there is limited information about the influence of chronic exposure to LFN at moderate levels for balance. In this study, we investigated whether chronic exposure to LFN at a moderate level of 70 dB SPL affects the vestibule, which is one of the organs responsible for balance in mice. Wild-type ICR mice were exposed for 1 month to LFN (0.1 kHz) and high frequency noise (HFN; 16 kHz) at 70 dB SPL at a distance of approximately 10–20 cm. Behavior analyses including rotarod, beam-crossing and footprint analyses showed impairments of balance in LFN-exposed mice but not in non-exposed mice or HFN-exposed mice. Immunohistochemical analysis showed a decreased number of vestibular hair cells and increased levels of oxidative stress in LFN-exposed mice compared to those in non-exposed mice. Our results suggest that chronic exposure to LFN at moderate levels causes impaired balance involving morphological impairments of the vestibule with enhanced levels of oxidative stress. Thus, the results of this study indicate the importance of considering the risk of chronic exposure to LFN at a moderate level for imbalance. PMID:22768129

Hepatic Metabolomics Investigation in Acute and Chronic Murine Toxoplasmosis.

PubMed

Chen, Xiao-Qing; Elsheikha, Hany M; Hu, Rui-Si; Hu, Gui-Xue; Guo, Shu-Ling; Zhou, Chun-Xue; Zhu, Xing-Quan

2018-01-01

Toxoplasma gondii poses a great threat to human health, with no approved vaccine available for the treatment of T. gondii infection. T. gondii infections are not limited to the brain, and may also affect other organs especially the liver. Identification of host liver molecules or pathways involved in T. gondii replication process may lead to the discovery of novel anti- T. gondii targets. Here, we analyzed the metabolic profile of the liver of mice on 11 and 30 days postinfection (dpi) with type II T. gondii Pru strain. Global metabolomics using liquid chromatography-tandem mass spectrometry (LC-MS/MS) identified 389 significant metabolites from acutely infected mice; and 368 from chronically infected mice, when compared with control mice. Multivariate statistical analysis revealed distinct metabolic signatures from acutely infected, chronically infected and control mice. Infection influenced several metabolic processes, in particular those for lipids and amino acids. Metabolic pathways, such as steroid hormone biosynthesis, primary bile acid biosynthesis, bile secretion, and biosynthesis of unsaturated fatty acids were perturbed during the whole infection process, particularly during the acute stage of infection. The present results provide insight into hepatic metabolic changes that occur in BALB/c mice during acute and chronic T. gondii infection.

Chronic hypersensitivity pneumonitis caused by Saccharopolyspora rectivirgula is not associated with a switch to a Th2 response

PubMed Central

Andrews, Kelly; Ghosh, Manik C.; Schwingshackl, Andreas; Rapalo, Gabriel; Luellen, Charlean; Waters, Christopher M.

2015-01-01

Hypersensitivity pneumonitis (HP) is an immune-mediated interstitial lung disease that develops following repeated exposure to inhaled environmental antigens. The disease results in alveolitis and granuloma formation and may progress to a chronic form associated with fibrosis; a greater understanding of the immunopathogenic mechanisms leading to chronic HP is needed. We used the Saccharopolyspora rectivirgula (SR) mouse model of HP to determine the extent to which a switch to a Th2-type immune response is associated with chronic HP. Exposure of wild-type (WT) and tlr2/9−/− mice to SR for 14 wk resulted in neutrophilic and lymphocytic alveolitis that was not dependent on Toll-like receptors (TLRs) 2 and 9. Long-term exposure of WT mice to SR resulted in a significant increase in collagen deposition, protein leakage, and IL-1α accompanied by a decrease in quasistatic compliance and total lung capacity compared with unexposed mice. This was associated with an increase in IL-17 but not IL-4 production or recruitment of Th2 cells. tlr2/9−/− mice exhibited an increase in protein leakage but less IL-1α and collagen deposition in the lungs compared with WT mice, yet they still displayed a decrease in quasistatic compliance, although total lung capacity was not affected. These mice exhibited an increase in both IL-13 and IL-17, which suggests that IL-13 may ameliorate some of the lung damage caused by long-term SR exposure. Our results suggest that lung pathology following long-term SR exposure in WT mice is associated with the IL-17 response and that TLRs 2 and 9 may inhibit the development of the IL-13/Th2 response. PMID:26719148

Secoisolariciresinol diglycoside, a flaxseed lignan, exerts analgesic effects in a mouse model of type 1 diabetes: Engagement of antioxidant mechanism.

PubMed

Hu, Pei; Mei, Qi-Yong; Ma, Li; Cui, Wu-Geng; Zhou, Wen-Hua; Zhou, Dong-Sheng; Zhao, Qing; Xu, Dong-Ying; Zhao, Xin; Lu, Qin; Hu, Zhen-Yu

2015-11-15

Peripheral painful neuropathy is one of the most common complications in diabetes and necessitates improved treatment. Secoisolariciresinol diglycoside (SDG), a predominant lignan in flaxseed, has been shown in our previous studies to exert antidepressant-like effect. As antidepressant drugs are clinically used to treat chronic neuropathic pain, this work aimed to investigate the potential analgesic efficacy of SDG against diabetic neuropathic pain in a mouse model of type 1 diabetes. We subjected mice to diabetes by a single intraperitoneal (i.p.) injection of streptozotocin (STZ, 200 mg/kg), and Hargreaves test or von Frey test was used to assess thermal hyperalgesia or mechanical allodynia, respectively. Chronic instead of acute SDG treatment (3, 10 or 30 mg/kg, p.o., twice per day for three weeks) ameliorated thermal hyperalgesia and mechanical allodynia in diabetic mice, and these analgesic actions persisted about three days when SDG treatment was terminated. Although chronic treatment of SDG to diabetic mice did not impact on the symptom of hyperglycemia, it greatly attenuated excessive oxidative stress in sciatic nerve and spinal cord tissues, and partially counteracted the condition of weight decrease. Furthermore, the analgesic actions of SDG were abolished by co-treatment with the reactive oxygen species donor tert-butyl hydroperoxide (t-BOOH), but potentiated by the reactive oxygen species scavenger phenyl-N-tert-butylnitrone (PBN). These findings indicate that chronic SDG treatment can correct neuropathic hyperalgesia and allodynia in mice with type 1 diabetes. Mechanistically, the analgesic actions of SDG in diabetic mice may be associated with its antioxidant activity. Copyright © 2015. Published by Elsevier B.V.

Regeneration of the Exocrine Pancreas Is Delayed in Telomere-Dysfunctional Mice

PubMed Central

von Figura, Guido; Wagner, Martin; Nalapareddy, Kodandaramireddy; Hartmann, Daniel; Kleger, Alexander; Guachalla, Luis Miguel; Rolyan, Harshvardhan; Adler, Guido; Rudolph, Karl Lenhard

2011-01-01

Introduction Telomere shortening is a cell-intrinsic mechanism that limits cell proliferation by induction of DNA damage responses resulting either in apoptosis or cellular senescence. Shortening of telomeres has been shown to occur during human aging and in chronic diseases that accelerate cell turnover, such as chronic hepatitis. Telomere shortening can limit organ homeostasis and regeneration in response to injury. Whether the same holds true for pancreas regeneration in response to injury is not known. Methods In the present study, pancreatic regeneration after acute cerulein-induced pancreatitis was studied in late generation telomerase knockout mice with short telomeres compared to telomerase wild-type mice with long telomeres. Results Late generation telomerase knockout mice exhibited impaired exocrine pancreatic regeneration after acute pancreatitis as seen by persistence of metaplastic acinar cells and markedly reduced proliferation. The expression levels of p53 and p21 were not significantly increased in regenerating pancreas of late generation telomerase knockout mice compared to wild-type mice. Conclusion Our results indicate that pancreatic regeneration is limited in the context of telomere dysfunction without evidence for p53 checkpoint activation. PMID:21364961

Impact of PACAP and PAC1 receptor deficiency on the neurochemical and behavioral effects of acute and chronic restraint stress in male C57BL/6 mice.

PubMed

Mustafa, Tomris; Jiang, Sunny Zhihong; Eiden, Adrian M; Weihe, Eberhard; Thistlethwaite, Ian; Eiden, Lee E

2015-01-01

Acute restraint stress (ARS) for 3 h causes corticosterone (CORT) elevation in venous blood, which is accompanied by Fos up-regulation in the paraventricular nucleus (PVN) of male C57BL/6 mice. CORT elevation by ARS is attenuated in PACAP-deficient mice, but unaffected in PAC1-deficient mice. Correspondingly, Fos up-regulation by ARS is greatly attenuated in PACAP-deficient mice, but much less so in PAC1-deficient animals. We noted that both PACAP- and PAC1-deficiency greatly attenuate CORT elevation after ARS when CORT measurements are performed on trunk blood following euthanasia by abrupt cervical separation: this latter observation is of critical importance in assessing the role of PACAP neurotransmission in ARS, based on previous reports in which serum CORT was sampled from trunk blood. Seven days of chronic restraint stress (CRS) induces non-habituating CORT elevation, and weight loss consequent to hypophagia, in wild-type male C57BL/6 mice. Both CORT elevation and weight loss following 7-day CRS are severely blunted in PACAP-deficient mice, but only slightly in PAC1-deficient mice. However, longer periods of daily restraint (14-21 days) resulted in sustained weight loss and elevated CORT in wild-type mice, and these effects of long-term chronic stress were attenuated or abolished in both PACAP- and PAC1-deficient mice. We conclude that while a PACAP receptor in addition to PAC1 may mediate some of the PACAP-dependent central effects of ARS and short-term (<7 days) CRS on the hypothalamo-pituitary-adrenal (HPA) axis, the PAC1 receptor plays a prominent role in mediating PACAP-dependent HPA axis activation, and hypophagia, during long-term (>7 days) CRS.

Identification of the key molecules involved in chronic copper exposure-aggravated memory impairment in transgenic mice of Alzheimer's disease using proteomic analysis.

PubMed

Yu, Jun; Luo, Xiaobin; Xu, Hua; Ma, Quan; Yuan, Jianhui; Li, Xuling; Chang, Raymond Chuen-Chung; Qu, Zhongsen; Huang, Xinfeng; Zhuang, Zhixiong; Liu, Jianjun; Yang, Xifei

2015-01-01

Alzheimer's disease (AD) is the most common neurodegenerative disease characterized by a progressive impairment of cognitive functions including spatial learning and memory. Excess copper exposure accelerates the development of AD; however, the potential mechanisms by which copper exacerbates the symptoms of AD remain unknown. In this study, we explored the effects of chronic copper exposure on cognitive function by treating 6 month-old triple AD transgenic (3xTg-AD) mice with 250 ppm copper sulfate in drinking water for 6 months, and identified several potential key molecules involved in the effects of chronic copper exposure on memory by proteomic analysis. The behavioral test showed that chronic copper exposure aggravated memory impairment of 3xTg-AD mice. Two-dimensional fluorescence difference gel electrophoresis (2D-DIGE) coupled with mass spectrometry revealed a total of 44 differentially expressed proteins (18 upregulated and 26 down-regulated) in hippocampus between the wild-type (WT) mice and non-exposed 3xTg-AD mice. A total of 40 differentially expressed proteins were revealed (20 upregulated and 20 down-regulated) in hippocampus between copper exposed and non-exposed 3xTg-AD mice. Among these differentially expressed proteins, complexin-1 and complexin-2, two memory associated proteins, were significantly decreased in hippocampus of 3xTg-AD mice compared with the WT mice. Furthermore, the expression of these two proteins was further down-regulated in 3xTg-AD mice when exposed to copper. The abnormal expression of complexin-1 and complexin-2 identified by proteomic analysis was verified by western blot analysis. Taken together, our data showed that chronic copper exposure accelerated memory impairment and altered the expression of proteins in hippocampus in 3xTg-AD mice. The functional analysis on the differentially expressed proteins suggested that complexin-1 and complexin-2 may be the key molecules involved in chronic copper exposure-aggravated memory impairment in AD.

Lack of stress responses to long-term effects of corticosterone in Caps2 knockout mice.

PubMed

Mishima, Yuriko; Shinoda, Yo; Sadakata, Tetsushi; Kojima, Masami; Wakana, Shigeharu; Furuichi, Teiichi

2015-03-10

Chronic stress is associated with anxiety and depressive disorders, and can cause weight gain. Ca(2+)-dependent activator protein for secretion 2 (CAPS2) is involved in insulin release. Caps2 knockout (KO) mice exhibit decreased body weight, reduced glucose-induced insulin release, and abnormal psychiatric behaviors. We chronically administered the stress hormone corticosterone (CORT), which induces anxiety/depressive-like behavior and normally increases plasma insulin levels, via the drinking water for 10 weeks, and we examined the stress response in KO mice. Chronic CORT exposure inhibited stress-induced serum CORT elevation in wild-type (WT) mice, but not in KO mice. Poor weight gain in CORT-treated animals was observed until week 6 in WT mice, but persisted for the entire duration of the experiment in KO mice, although there is no difference in drug*genotype interaction. Among KO mice, food consumption was unchanged, while water consumption was higher, over the duration of the experiment in CORT-treated animals, compared with untreated animals. Moreover, serum insulin and leptin levels were increased in CORT-treated WT mice, but not in KO mice. Lastly, both WT and KO mice displayed anxiety/depressive-like behavior after CORT administration. These results suggest that Caps2 KO mice have altered endocrine responses to CORT administration, while maintaining CORT-induced anxiety/depressive-like behavior.

Diabetes-causing gene, kruppel-like factor 11, modulates the antinociceptive response of chronic ethanol intake.

PubMed

Ou, Xiao-Ming; Udemgba, Chinelo; Wang, Niping; Dai, Xiaoli; Lomberk, Gwen; Seo, Seungmae; Urrutia, Raul; Wang, Junming; Duncan, Jeremy; Harris, Sharonda; Fairbanks, Carolyn A; Zhang, Xiao

2014-02-01

Alcohol (EtOH [ethanol]) is an antinociceptive agent, working in part, by reducing sensitivity to painful stimuli. The transcription factor Kruppel-like factor 11 (KLF11), a human diabetes-causing gene that also regulates the neurotransmitter metabolic enzymes monoamine oxidase (MAO), has recently been identified as an EtOH-inducible gene. However, its role in antinociception remains unknown. Consequently, we investigated the function of KLF11 in chronic EtOH-induced antinociception using a genetically engineered knockout mouse model. Wild-type (Klf11(+/+) ) and KLF11 knockout (Klf11(-/-) ) mice were fed a liquid diet containing EtOH for 28 days with increasing amounts of EtOH from 0% up to a final concentration of 6.4%, representing a final diet containing 36% of calories primarily from EtOH. Control mice from both genotypes were fed liquid diet without EtOH for 28 days. The EtOH-induced antinociceptive effect was determined using the tail-flick test before and after EtOH exposure (on day 29). In addition, the enzyme activity and mRNA levels of MAO A and MAO B were measured by real-time RT-PCR and enzyme assays, respectively. EtOH produced an antinociceptive response to thermal pain in Klf11(+/+) mice, as expected. In contrast, deletion of KLF11 in the Klf11(-/-) mice abolished the EtOH-induced antinociceptive effect. The mRNA and protein levels of KLF11 were significantly increased in the brain prefrontal cortex of Klf11(+/+) mice exposed to EtOH compared with control Klf11(+/+) mice. Furthermore, MAO enzyme activities were affected differently in Klf11 wild-type versus Klf11 knockout mice exposed to chronic EtOH. Chronic EtOH intake significantly increased MAO B activity in Klf11(+/+) mice. The data show KLF11 modulation of EtOH-induced antinociception. The KLF11-targeted MAO B enzyme may contribute more significantly to EtOH-induced antinociception. Thus, this study revealed a new role for the KLF11 gene in the mechanisms underlying the antinociceptive effects of chronic EtOH exposure. Copyright © 2013 by the Research Society on Alcoholism.

Diabetes Causing Gene, Kruppel-Like Factor 11, Modulates the Antinociceptive Response of Chronic Ethanol Intake

PubMed Central

Ou, Xiao-Ming; Udemgba, Chinelo; Wang, Niping; Dai, Xiaoli; Lomberk, Gwen; Seo, Seungmae; Urrutia, Raul; Wang, Junming; Duncan, Jeremy; Harris, Sharonda; Fairbanks, Carolyn A.; Zhang, Xiao

2017-01-01

Background Alcohol (ethanol) is an antinociceptive agent, working in part, by reducing sensitivity to painful stimuli. The transcription factor, Kruppel-like factor 11 (KLF11), a human diabetes-causing gene that also regulates the neurotransmitter-metabolic enzymes monoamine oxidase (MAOs), has recently been identified as an ethanol-inducible gene. However, its role in antinociception remains unknown. Consequently, we investigated the function of KLF11 in chronic ethanol-induced antinociception using a genetically engineered knockout mouse model. Methods Wild-type (Klf11+/+) and KLF11 knockout (Klf11−/−) mice were fed a liquid diet containing ethanol for 28 days with increasing amounts of ethanol from 0% up to a final concentration of 6.4%, representing a final diet containing 36% of calories primarily from ethanol. Control mice from both genotypes were fed liquid diet without ethanol for 28 days. The ethanol-induced antinociceptive effect was determined using the tail-flick test before and after ethanol exposure (on day 29). In addition, the enzyme activity and mRNA levels of MAO A and MAO B were measured by Real-time RT-PCR and enzyme assays, respectively. Results Ethanol produced an antinociceptive response to thermal pain in Klf11+/+ mice, as expected. In contrast, deletion of KLF11 in the Klf11−/− mice abolished the ethanol-induced antinociceptive effect. The mRNA and protein levels of KLF11were significantly increased in the brain prefrontal cortex of Klf11+/+ mice exposed to ethanol compared to control Klf11+/+ mice. Furthermore, MAO enzyme activities were affected differently in Klf11 wild-type versus Klf11 knockout mice exposed to chronic ethanol. Chronic ethanol intake significantly increased MAO-B activity in Klf1+/+ mice. Conclusions The data show KLF11 modulation of ethanol-induced antinociception. The KLF11-targeted MAO B enzyme, may contribute more significantly to ethanol-induced antinociception. Thus, this study revealed a new role for the KLF11 gene in the mechanisms underlying the antinociceptive effects of chronic ethanol exposure. PMID:24428663

Behavioral alterations in cystic fibrosis mice are prevented by cannabinoid treatment in infancy.

PubMed

Bregman, Tatiana; Fride, Ester

2011-06-17

Substantial data have been accumulated regarding the molecular basis of cystic fibrosis (CF) pathogenesis, whereas the influence of biochemical impairments on brain processes has been the focus of much less attention. We have studied some behavioral parameters, such as motor activity and anxiety level, in a mice model of CF. We have assumed that functioning of the endocannabinoid system could be impaired in CF (endocannabinoids are fatty acid derivatives, and fatty acid deficiency is considered a major factor in CF etiology). We have suggested that chronic treatment with cannabinoid receptors agonist during infancy would balance cannabinoid levels and prevent CF-related behavioral alterations. Motor activity and anxiety level were studied in naïve adult CF mice (cftr-deficient mice) and compared with wild-type mice and to CF mice treated chronically with Δ9-tetrahydrocannabinol (Δ9-THC; endocannabinoid receptor agonist) during infancy (from days 7 to 28). Motor activity was tested in the tetrad, and level of anxiety in the plus maze, a month after cessation of treatment. Motor activity decrease and elevated anxiety level were found in adult naïve CF mice compared with wild-type mice. CF mice treated with THC in infancy showed normal motor activity and anxiety levels in adulthood. Motor function alteration and elevated anxiety levels in CF can result from lack of CFTR-channel in neurons and disturbed activity of various brain areas, as well as being secondary and mediated by fatty acids deficiency, altered levels of endocannabinoids and their receptors. It can be suggested that chronic treatment during infancy restores endocannabinoid function and thus prevents behavioral alterations.

Mu-opioid receptors in nociceptive afferents produce a sustained suppression of hyperalgesia in chronic pain.

PubMed

Severino, Amie; Chen, Wenling; Hakimian, Joshua K; Kieffer, Brigitte L; Gaveriaux-Ruff, Claire; Walwyn, Wendy; Marvizon, Juan Carlos

2018-04-17

The latent sensitization model of chronic pain reveals that recovery from some types of long-term hyperalgesia is an altered state in which nociceptive sensitization persists but is suppressed by the ongoing activity of analgesic receptors such as µ-opioid receptors (MORs). To determine whether these MORs are the ones present in nociceptive afferents, we bred mice expressing Cre-recombinase under the Nav1.8 channel promoter (Nav1.8cre) with MOR-floxed mice (flMOR). These Nav1.8cre/flMOR mice had reduced MOR expression in primary afferents, as revealed by quantitative PCR, in situ hybridization and immunofluorescence colocalization with the neuropeptide CGRP. We then studied the recovery from chronic pain of these mice and their flMOR littermates. When Nav1.8cre/flMOR mice were injected in the paw with complete Freund's adjuvant they developed mechanical hyperalgesia that persisted for over two months, whereas the responses of flMOR mice returned to baseline after three weeks. We then used the inverse agonist naltrexone to assess ongoing MOR activity. Naltrexone produced a robust reinstatement of hyperalgesia in control flMOR mice, but produced no effect in the Nav1.8/flMOR males and a weak reinstatement of hyperalgesia in Nav1.8/flMOR females. Naltrexone also reinstated swelling of the hind paw in flMOR mice and female Nav1.8cre/flMOR mice, but not male Nav1.8cre/flMOR mice. The MOR agonist DAMGO inhibited substance P release in flMOR mice but not Nav1.8cre/flMOR mice, demonstrating a loss of MOR function at the central terminals of primary afferents. We conclude that MORs in nociceptive afferents mediate an ongoing suppression of hyperalgesia to produce remission from chronic pain.

Toll-like receptor 4 contributes to chronic itch, alloknesis and spinal astrocyte activation in male mice

PubMed Central

Liu, Tong; Han, Qingjian; Chen, Gang; Huang, Ya; Zhao, Lin-Xia; Berta, Temugin; Gao, Yong-Jing; Ji, Ru-Rong

2016-01-01

Increasing evidence suggests that Toll-like receptor 4 (TLR4) contributes importantly to spinal cord glial activation and chronic pain sensitization; however, its unique role in acute and chronic itch is unclear. In this study, we investigated the involvement of TLR4 in acute and chronic itch models in male mice using both transgenic and pharmacological approaches. Tlr4−/− mice exhibited normal acute itch induced by compound 48/80 and chloroquine, but these mice showed substantial reductions in scratching in chronic itch models of dry skin, induced by acetone and diethyether followed by water (AEW), contact dermatitis, and allergic contact dermatitis on the neck. Intrathecal (spinal) inhibition of TLR4 with lipopolysaccharide Rhodobacter sphaeroides (LPS-RS) did not affect acute itch but suppressed AEW-induced chronic itch. Compound 48/80 and AEW also produced robust alloknesis, a touch-elicited itch in wild-type mice, which was suppressed by intrathecal LPS-RS and Tlr4−/− deletion. AEW induced persistent upregulation of Tlr4 mRNA and increased TLR4 expression in GFAP-expressing astrocytes in spinal cord dorsal horn. AEW also induced TLR4-dependent astrogliosis (GFAP upregulation) in spinal cord. Intrathecal injection of astroglial inhibitor L-α-aminoadipate reduced AEW-induced chronic itch and alloknesis without affecting acute itch. Spinal TLR4 was also necessary for AEW-induced chronic itch in the cheek model. Interestingly, scratching plays an essential role in spinal astrogliosis, since AEW-induced astrogliosis was abrogated by putting Elizabethan Collars on the neck to prevent scratching the itchy skin. Our findings suggest that spinal TLR4 signaling is important for spinal astrocyte activation and astrogliosis that may underlie alloknesis and chronic itch. PMID:26645545

Effects of insulin resistance on skeletal muscle growth and exercise capacity in type 2 diabetic mouse models

PubMed Central

Ostler, Joseph E.; Maurya, Santosh K.; Dials, Justin; Roof, Steve R.; Devor, Steven T.; Ziolo, Mark T.

2014-01-01

Type 2 diabetes mellitus is associated with an accelerated muscle loss during aging, decreased muscle function, and increased disability. To better understand the mechanisms causing this muscle deterioration in type 2 diabetes, we assessed muscle weight, exercise capacity, and biochemistry in db/db and TallyHo mice at prediabetic and overtly diabetic ages. Maximum running speeds and muscle weights were already reduced in prediabetic db/db mice when compared with lean controls and more severely reduced in the overtly diabetic db/db mice. In contrast to db/db mice, TallyHo muscle size dramatically increased and maximum running speed was maintained during the progression from prediabetes to overt diabetes. Analysis of mechanisms that may contribute to decreased muscle weight in db/db mice demonstrated that insulin-dependent phosphorylation of enzymes that promote protein synthesis was severely blunted in db/db muscle. In addition, prediabetic (6-wk-old) and diabetic (12-wk-old) db/db muscle exhibited an increase in a marker of proteasomal protein degradation, the level of polyubiquitinated proteins. Chronic treadmill training of db/db mice improved glucose tolerance and exercise capacity, reduced markers of protein degradation, but only mildly increased muscle weight. The differences in muscle phenotype between these models of type 2 diabetes suggest that insulin resistance and chronic hyperglycemia alone are insufficient to rapidly decrease muscle size and function and that the effects of diabetes on muscle growth and function are animal model-dependent. PMID:24425761

Oral administration of aflatoxin G₁ induces chronic alveolar inflammation associated with lung tumorigenesis.

PubMed

Liu, Chunping; Shen, Haitao; Yi, Li; Shao, Peilu; Soulika, Athena M; Meng, Xinxing; Xing, Lingxiao; Yan, Xia; Zhang, Xianghong

2015-02-03

Our previous studies showed oral gavage of aflatoxin G₁ (AFG₁) induced lung adenocarcinoma in NIH mice. We recently found that a single intratracheal administration of AFG₁ caused chronic inflammatory changes in rat alveolar septum. Here, we examine whether oral gavage of AFG₁ induces chronic lung inflammation and how it contributes to carcinogenesis. We evaluated chronic lung inflammatory responses in Balb/c mice after oral gavage of AFG₁ for 1, 3 and 6 months. Inflammatory responses were heightened in the lung alveolar septum, 3 and 6 months after AFG₁ treatment, evidenced by increased macrophages and lymphocytes infiltration, up-regulation of NF-κB and p-STAT3, and cytokines production. High expression levels of superoxide dismutase (SOD-2) and hemoxygenase-1 (HO-1), two established markers of oxidative stress, were detected in alveolar epithelium of AFG₁-treated mice. Promoted alveolar type II cell (AT-II) proliferation in alveolar epithelium and angiogenesis, as well as increased COX-2 expression were also observed in lung tissues of AFG₁-treated mice. Furthermore, we prolonged survival of the mice in the above model for another 6 months to examine the contribution of AFG₁-induced chronic inflammation to lung tumorigenesis. Twelve months later, we observed that AFG₁ induced alveolar epithelial hyperplasia and adenocarcinoma in Balb/c mice. Up-regulation of NF-κB, p-STAT3, and COX-2 was also induced in lung adenocarcinoma, thus establishing a link between AFG₁-induced chronic inflammation and lung tumorigenesis. This is the first study to show that oral administration of AFG₁ could induce chronic lung inflammation, which may provide a pro-tumor microenvironment to contribute to lung tumorigenesis. Copyright © 2014. Published by Elsevier Ireland Ltd.

Constitutive glycogen synthase kinase-3α/β activity protects against chronic β-adrenergic remodelling of the heart

PubMed Central

Webb, Ian G.; Nishino, Yasuhiro; Clark, James E.; Murdoch, Colin; Walker, Simon J.; Makowski, Marcus R.; Botnar, Rene M.; Redwood, Simon R.; Shah, Ajay M.; Marber, Michael S.

2010-01-01

Aims Glycogen synthase kinase 3 (GSK-3) signalling is implicated in the growth of the heart during development and in response to stress. However, its precise role remains unclear. We set out to characterize developmental growth and response to chronic isoproterenol (ISO) stress in knockin (KI) mice lacking the critical N-terminal serines, 21 of GSK-3α and 9 of GSK-3β respectively, required for inactivation by upstream kinases. Methods and results Between 5 and 15 weeks, KI mice grew more rapidly, but normalized heart weight and contractile performance were similar to wild-type (WT) mice. Isolated hearts of both genotypes responded comparably to acute ISO infusion with increases in heart rate and contractility. In WT mice, chronic subcutaneous ISO infusion over 14 days resulted in cardiac hypertrophy, interstitial fibrosis, and impaired contractility, accompanied by foetal gene reactivation. These effects were all significantly attenuated in KI mice. Indeed, ISO-treated KI hearts demonstrated reversible physiological remodelling traits with increased stroke volume and a preserved contractile response to acute adrenergic stimulation. Furthermore, simultaneous pharmacological inhibition of GSK-3 in KI mice treated with chronic subcutaneous ISO recapitulated the adverse remodelling phenotype seen in WT hearts. Conclusion Expression of inactivation-resistant GSK-3α/β does not affect eutrophic myocardial growth but protects against pathological hypertrophy induced by chronic adrenergic stimulation, maintaining cardiac function and attenuating interstitial fibrosis. Accordingly, strategies to prevent phosphorylation of Ser-21/9, and consequent inactivation of GSK-3α/β, may enable a sustained cardiac response to chronic β-agonist stimulation while preventing pathological remodelling. PMID:20299330

IL-33 and Thymic Stromal Lymphopoietin Mediate Immune Pathology in Response to Chronic Airborne Allergen Exposure

PubMed Central

Iijima, Koji; Kobayashi, Takao; Hara, Kenichiro; Kephart, Gail M.; Ziegler, Steven F.; McKenzie, Andrew N.; Kita, Hirohito

2014-01-01

Humans are frequently exposed to various airborne allergens in the atmospheric environment. These allergens may trigger a complex network of immune responses in the airways, resulting in asthma and other chronic airway diseases. Here, we investigated the immunological mechanisms involved in the pathological changes induced by chronic exposure to multiple airborne allergens. Naïve mice were exposed intranasally to a combination of common airborne allergens, including the house dust mite, Alternaria, and Aspergillus, for up to 8 weeks. These allergens acted synergistically and induced robust eosinophilic airway inflammation, specific IgE antibody production, type 2 cytokine response and airway hyperreactivity (AHR) in 4 weeks, followed by airway remodeling in 8 weeks. Increased lung infiltration of T cells, B cells, and type 2 innate lymphoid cells (ILC2s) was observed. CD4+ T cells and ILC2s contributed to the sources of IL-5 and IL-13, suggesting involvement of both innate and adaptive immunity in this model. The lung levels of IL-33 increased quickly within several hours after allergen exposure and continued to rise throughout the chronic phase of inflammation. Mice deficient in IL-33 receptor (Il1rl1−/−) and TSLP receptor (Tslpr−/−) showed significant reduction in airway inflammation, IgE antibody levels and AHR. In contrast, mice deficient in IL-25 receptor or IL-1 receptor showed minimal differences as compared to wild-type animals. Thus, chronic exposure to natural airborne allergens triggers a network of innate and adaptive type 2 immune responses and airway pathology, and IL-33 and TSLP likely play key roles in this process. PMID:25015831

Effects on enantiomeric drug disposition and open-field behavior after chronic treatment with venlafaxine in the P-glycoprotein knockout mice model.

PubMed

Karlsson, Louise; Hiemke, Christoph; Carlsson, Björn; Josefsson, Martin; Ahlner, Johan; Bengtsson, Finn; Schmitt, Ulrich; Kugelberg, Fredrik C

2011-05-01

P-glycoprotein (P-gp) plays an important role in the efflux of drugs from the brain back into the bloodstream and can influence the pharmacokinetics and pharmacodynamics of drug molecules. To our knowledge, no studies have reported pharmacodynamic effects of any antidepressant drug in the P-gp knockout mice model. The aim of this study was to investigate the enantiomeric venlafaxine and metabolite concentrations in serum and brain of abcb1ab⁻/⁻ mice compared to wild-type mice upon chronic dosing, and to assess the effect of venlafaxine treatment on open-field behavior. P-gp knockout and wild-type mice received two daily intraperitoneal injections of venlafaxine (10 mg/kg) over ten consecutive days. Locomotor and rearing activities were assessed on days 7 and 9. After 10 days, drug and metabolite concentrations in brain and serum were determined using an enantioselective LC/MS/MS method. The brain concentrations of venlafaxine and its three demethylated metabolites were two to four times higher in abcb1ab⁻/⁻ mice compared to abcb1ab+/+ mice. The behavioral results indicated an impact on exploration-related behaviors in the open-field as center activity was increased, and rears were decreased by venlafaxine treatment. Our results show that P-gp at the blood-brain barrier plays an important role in limiting brain entry of the enantiomers of venlafaxine and its metabolites after chronic dosing. Taken together, the present pharmacokinetic and pharmacodynamic findings offer the possibility that the expression of P-gp in patients may be a contributing factor for limited treatment response.

Impact of small-molecule glucokinase activator on glucose metabolism and beta-cell mass.

PubMed

Nakamura, Akinobu; Terauchi, Yasuo; Ohyama, Sumika; Kubota, Junko; Shimazaki, Hiroko; Nambu, Tadahiro; Takamoto, Iseki; Kubota, Naoto; Eiki, Junichi; Yoshioka, Narihito; Kadowaki, Takashi; Koike, Takao

2009-03-01

We investigated the effect of glucokinase activator (GKA) on glucose metabolism and beta-cell mass. We analyzed four mouse groups: wild-type mice and beta-cell-specific haploinsufficiency of glucokinase gene (Gck(+/-)) mice on a high-fat (HF) diet. Each genotype was also treated with GKA mixed in the HF diet. Rodent insulinoma cells and isolated islets were used to evaluate beta-cell proliferation by GKA. After 20 wk on the above diets, there were no differences in body weight, lipid profiles, and liver triglyceride content among the four groups. Glucose tolerance was improved shortly after the GKA treatment in both genotypes of mice. beta-Cell mass increased in wild-type mice compared with Gck(+/-) mice, but a further increase was not observed after the administration of GKA in both genotypes. Interestingly, GKA was able to up-regulate insulin receptor substrate-2 (Irs-2) expression in insulinoma cells and isolated islets. The administration of GKA increased 5-bromo-2-deoxyuridine (BrdU) incorporation in insulinoma cells, and 3 d administration of GKA markedly increased BrdU incorporation in mice treated with GKA in both genotypes, compared with those without GKA. In conclusion, GKA was able to chronically improve glucose metabolism for mice on the HF diet. Although chronic GKA administration failed to cause a further increase in beta-cell mass in vivo, GKA was able to increase beta cell proliferation in vitro and with a 3-d administration in vivo. This apparent discrepancy can be explained by a chronic reduction in ambient blood glucose levels by GKA treatment.

Anti-FcεR1 antibody injections activate basophils and mast cells and delay Type I diabetes onset in NOD mice

PubMed Central

Larson, David; Torrero, Marina N.; Mueller, Ellen; Shi, Yinghui; Killoran, Kristin

2012-01-01

Mounting evidence suggests that helminth infections protect against autoimmune diseases. As helminths cause chronic IgE-mediated activation of basophils and mast cells we hypothesized that continuous activation of these cells could prevents diabetes onset in nonobese diabetic (NOD) mice in the absence of infection. Anti-FcεR1 activated basophils and mast cells and resulted in the release of IL-4 and histamine into the bloodstream. Anti-FcεR1-treated NOD mice showed a type 2 shift in insulin-specific antibody production and exhibited significant delays in diabetes onset. IL-4 responses played a partial role as the protective effect of anti-FcεR1 therapy was diminished in IL-4-deficient NOD mice. In contrast, histamine signaling was not required as anti-FcεR1-mediated protection was not reduced in mice treated with histamine receptor blockers. These results demonstrate that anti-FcεR1 therapy delays diabetes onset in NOD mice and suggest that chronic basophil and mast cell activation may represent a new avenue of therapy for Th1-associated autoimmune diseases. PMID:21920822

Swim stress reduces chronic pain in mice through an opioid mechanism.

PubMed

Carmody, J; Cooper, K

1987-03-09

Chronic nociception has been studied in male mice by means of the formalin test in which forelimb motor behaviour is scored after subcutaneous formalin injection. The rating remained above 2.0 for 30 min after the injection (scale range 0-3). The magnitude of the nociception has been compared with that reported in other animal types. Mice are more sensitive than rats, cats and monkeys. The stress of a swim of 3 min has been found to reduce nociception by up to 25%. This analgesia is wholly opioid in nature, being abolished by a moderate dose of naloxone (1 mg/kg).

Chronic liver injury in mice promotes impairment of skin barrier function via tumor necrosis factor-alpha.

PubMed

Yokoyama, Satoshi; Hiramoto, Keiichi; Koyama, Mayu; Ooi, Kazuya

2016-09-01

Alcohol is frequently used to induce chronic liver injury in laboratory animals. Alcohol causes oxidative stress in the liver and increases the expression of inflammatory mediators that cause hepatocellular damage. However, during chronic liver injury, it is unclear if/how these liver-derived factors affect distal tissues, such as the skin. The purpose of this study was to evaluate skin barrier function during chronic liver injury. Hairless mice were administered 5% or 10% ethanol for 8 weeks, and damages to the liver and skin were assessed using histological and protein-analysis methods, as well as by detecting inflammatory mediators in the plasma. After alcohol administration, the plasma concentration of the aspartate and alanine aminotransferases increased, while albumin levels decreased. In mice with alcohol-induced liver injury, transepidermal water loss was significantly increased, and skin hydration decreased concurrent with ceramide and type I collagen degradation. The plasma concentrations of [Formula: see text]/[Formula: see text] and tumor necrosis factor-alpha (TNF-α) were significantly increased in mice with induced liver injury. TNF receptor (TNFR) 2 expression was upregulated in the skin of alcohol-administered mice, while TNFR1 levels remained constant. Interestingly, the impairment of skin barrier function in mice administered with 10% ethanol was ameliorated by administering an anti-TNF-α antibody. We propose a novel mechanism whereby plasma TNF-α, via TNFR2 alone or with TNFR1, plays an important role in skin barrier function during chronic liver disease in these mouse models.

Obesity-induced DNA released from adipocytes stimulates chronic adipose tissue inflammation and insulin resistance.

PubMed

Nishimoto, Sachiko; Fukuda, Daiju; Higashikuni, Yasutomi; Tanaka, Kimie; Hirata, Yoichiro; Murata, Chie; Kim-Kaneyama, Joo-Ri; Sato, Fukiko; Bando, Masahiro; Yagi, Shusuke; Soeki, Takeshi; Hayashi, Tetsuya; Imoto, Issei; Sakaue, Hiroshi; Shimabukuro, Michio; Sata, Masataka

2016-03-01

Obesity stimulates chronic inflammation in adipose tissue, which is associated with insulin resistance, although the underlying mechanism remains largely unknown. Here we showed that obesity-related adipocyte degeneration causes release of cell-free DNA (cfDNA), which promotes macrophage accumulation in adipose tissue via Toll-like receptor 9 (TLR9), originally known as a sensor of exogenous DNA fragments. Fat-fed obese wild-type mice showed increased release of cfDNA, as determined by the concentrations of single-stranded DNA (ssDNA) and double-stranded DNA (dsDNA) in plasma. cfDNA released from degenerated adipocytes promoted monocyte chemoattractant protein-1 (MCP-1) expression in wild-type macrophages, but not in TLR9-deficient (Tlr9 (-/-) ) macrophages. Fat-fed Tlr9 (-/-) mice demonstrated reduced macrophage accumulation and inflammation in adipose tissue and better insulin sensitivity compared with wild-type mice, whereas bone marrow reconstitution with wild-type bone marrow restored the attenuation of insulin resistance observed in fat-fed Tlr9 (-/-) mice. Administration of a TLR9 inhibitory oligonucleotide to fat-fed wild-type mice reduced the accumulation of macrophages in adipose tissue and improved insulin resistance. Furthermore, in humans, plasma ssDNA level was significantly higher in patients with computed tomography-determined visceral obesity and was associated with homeostasis model assessment of insulin resistance (HOMA-IR), which is the index of insulin resistance. Our study may provide a novel mechanism for the development of sterile inflammation in adipose tissue and a potential therapeutic target for insulin resistance.

Vulnerable atherosclerotic plaque morphology in apolipoprotein E-deficient mice unable to make ascorbic Acid.

PubMed

Nakata, Yukiko; Maeda, Nobuyo

2002-03-26

Oxidative stress is thought to play an important role in atherogenesis, suggesting that antioxidants could prevent coronary artery disease. However, the efficacy of vitamin C in reducing atherosclerosis is debatable in humans and has not been tested rigorously in animals. Gulo(-/-)Apoe(-/-) mice were used to test a hypothesis that chronic vitamin C deficiency enhances the initiation and development of atherosclerosis. These mice are dependent on dietary vitamin C because of the lack of L-gulonolactone-gamma-oxidase and are prone to develop atherosclerosis because of lacking apolipoprotein E. Beginning at 6 weeks of age, the Gulo(-/-)Apoe(-/-) mice were fed regular chow or Western-type diets containing high fat and supplemented with either 0.033 g or 3.3 g/L of vitamin C in their drinking water. This regimen produced mice with chronically low vitamin C (average 1.5 microg/mL in plasma) or high vitamin C (average 10 to 30 microg/mL in plasma). Morphometric analysis showed that within each sex, age, and diet group, the sizes of the atherosclerotic plaques were not different between low vitamin C mice and high vitamin C mice. However, advanced plaques in the low vitamin C mice had significantly reduced amounts of Sirius red-staining collagen (36.4+/-2.2% versus 54.8+/-2.3%, P<0.0001), larger necrotic cores within the plaques, and reduced fibroproliferation and neovascularization in the aortic adventitia. Chronic vitamin C deficiency does not influence the initiation or progression of atherosclerotic plaques but severely compromises collagen deposition and induces a type of plaque morphology that is potentially vulnerable to rupture.

Interleukin-32γ attenuates ethanol-induced liver injury by the inhibition of cytochrome P450 2E1 expression and inflammatory responses.

PubMed

Lee, Dong Hun; Kim, Dae Hwan; Hwang, Chul Ju; Song, Sukgil; Han, Sang Bae; Kim, Youngsoo; Yoo, Hwan Soo; Jung, Young Suk; Kim, Soo Hyun; Yoon, Do Young; Hong, Jin Tae

2015-05-01

Alcohol abuse and alcoholism lead to alcoholic liver disease (ALD), which is a major type of chronic liver disease worldwide. Interleukin-32 (IL-32) is a novel cytokine involved in inflammation and cancer development. However, the role of IL-32 in chronic liver disease has not been reported. In the present paper, we tested the effect of IL-32γ on ethanol-induced liver injury in IL-32γ-overexpressing transgenic mice (IL-32γ mice) after chronic ethanol feeding. Male C57BL/6 and IL-32γ mice (10-12 weeks old) were fed on a Lieber-DeCarli diet containing 6.6% ethanol for 6 weeks. IL-32γ-transfected HepG2 and Huh7 cells, as well as primary hepatocytes from IL-32γ mice, were treated with or without ethanol. The hepatic steatosis and damage induced by ethanol administration were attenuated in IL-32γ mice. Ethanol-induced cytochrome P450 2E1 expression and hydrogen peroxide levels were decreased in the livers of IL-32γ mice, primary hepatocytes from IL-32γ mice and IL-32γ-overexpressing human hepatic cells. The ethanol-induced expression levels of cyclo-oxygenase-2 (COX-2) and IL-6 were reduced in the livers of IL-32γ mice. Because nuclear transcription factor κB (NF-κB) is a key redox transcription factor of inflammatory responses, we examined NF-κB activity. Ethanol-induced NF-κB activities were significantly lower in the livers of IL-32γ mice than in wild-type (WT) mice. Furthermore, reduced infiltration of natural killer cells, cytotoxic T-cells and macrophages in the liver after ethanol administration was observed in IL-32γ mice. These data suggest that IL-32γ prevents ethanol-induced hepatic injury via the inhibition of oxidative damage and inflammatory responses.

Chronic Treatment with Mood-Stabilizers Attenuates Abnormal Hyperlocomotion of GluA1-Subunit Deficient Mice

PubMed Central

Maksimovic, Milica; Vekovischeva, Olga Y.; Aitta-aho, Teemu; Korpi, Esa R.

2014-01-01

Abnormal excitatory glutamate neurotransmission and plasticity have been implicated in schizophrenia and affective disorders. Gria1−/− mice lacking GluA1 subunit (encoded by Gria1 gene) of AMPA-type glutamate receptor show robust novelty-induced hyperactivity, social deficits and heightened approach features, suggesting that they could be used to test for anti-manic activity of drugs. Here, we tested the efficacy of chronic treatment with established anti-manic drugs on behavioural properties of the Gria1−/− mice. The mice received standard mood stabilizers (lithium and valproate) and novel ones (topiramate and lamotrigine, used more as anticonvulsants) as supplements in rodent chow for at least 4 weeks. All drugs attenuated novelty-induced locomotor hyperactivity of the Gria1−/− mice, especially by promoting the habituation, while none of them attenuated 2-mg/kg amphetamine-induced hyperactivity as compared to control diet. Treatment with lithium and valproate reversed the elevated exploratory activity of Gria1−/− mice. Valproate treatment also reduced struggling behaviour in tail suspension test and restored reciprocally-initiated social contacts of Gria1−/− mice to the level shown by the wild-type Gria1+/+ mice. Gria1−/− mice consumed slightly more sucrose during intermittent sucrose exposure than the wild-types, but ran similar distances on running wheels. These behaviours were not consistently affected by lithium and valproate in the Gria1−/− mice. The efficacy of various anti-manic drug treatments on novelty-induced hyperactivity suggests that the Gria1−/− mouse line can be utilized in screening for new therapeutics. PMID:24932798

Gene Expression in Brain and Liver Produced by Three Different Regimens of Alcohol Consumption in Mice: Comparison with Immune Activation

PubMed Central

Osterndorff-Kahanek, Elizabeth; Ponomarev, Igor; Blednov, Yuri A.; Harris, R. Adron

2013-01-01

Chronically available alcohol escalates drinking in mice and a single injection of the immune activator lipopolysaccharide can mimic this effect and result in a persistent increase in alcohol consumption. We hypothesized that chronic alcohol drinking and lipopolysaccharide injections will produce some similar molecular changes that play a role in regulation of alcohol intake. We investigated the molecular mechanisms of chronic alcohol consumption or lipopolysaccharide insult by gene expression profiling in prefrontal cortex and liver of C57BL/6J mice. We identified similar patterns of transcriptional changes among four groups of animals, three consuming alcohol (vs water) in different consumption tests and one injected with lipopolysaccharide (vs. vehicle). The three tests of alcohol consumption are the continuous chronic two bottle choice (Chronic), two bottle choice available every other day (Chronic Intermittent) and limited access to one bottle of ethanol (Drinking in the Dark). Gene expression changes were more numerous and marked in liver than in prefrontal cortex for the alcohol treatments and similar in the two tissues for lipopolysaccharide. Many of the changes were unique to each treatment, but there was significant overlap in prefrontal cortex for Chronic-Chronic Intermittent and for Chronic Intermittent-lipopolysaccharide and in liver all pairs showed overlap. In silico cell-type analysis indicated that lipopolysaccharide had strongest effects on brain microglia and liver Kupffer cells. Pathway analysis detected a prefrontal cortex-based dopamine-related (PPP1R1B, DRD1, DRD2, FOSB, PDNY) network that was highly over-represented in the Chronic Intermittent group, with several genes from the network being also regulated in the Chronic and lipopolysaccharide (but not Drinking in the Dark) groups. Liver showed a CYP and GST centered metabolic network shared in part by all four treatments. We demonstrate common consequences of chronic alcohol consumption and immune activation in both liver and brain and show distinct genomic consequences of different types of alcohol consumption. PMID:23555817

Exacerbation of spontaneous autoimmune nephritis following regulatory T cell depletion in B cell lymphoma 2‐interacting mediator knock‐out mice

PubMed Central

Wang, Y. M.; Zhang, G. Y.; Wang, Y.; Hu, M.; Zhou, J. J.; Sawyer, A.; Cao, Q.; Wang, Y.; Zheng, G.; Lee, V. W. S.; Harris, D. C. H.

2017-01-01

Summary Regulatory T cells (Tregs) have been recognized as central mediators for maintaining peripheral tolerance and limiting autoimmune diseases. The loss of Tregs or their function has been associated with exacerbation of autoimmune disease. However, the temporary loss of Tregs in the chronic spontaneous disease model has not been investigated. In this study, we evaluated the role of Tregs in a novel chronic spontaneous glomerulonephritis model of B cell lymphoma 2‐interacting mediator (Bim) knock‐out mice by transient depleting Tregs. Bim is a pro‐apoptotic member of the B cell lymphoma 2 (Bcl‐2) family. Bim knock‐out (Bim–/–) mice fail to delete autoreactive T cells in thymus, leading to chronic spontaneous autoimmune kidney disease. We found that Treg depletion in Bim–/– mice exacerbated the kidney injury with increased proteinuria, impaired kidney function, weight loss and greater histological injury compared with wild‐type mice. There was a significant increase in interstitial infiltrate of inflammatory cells, antibody deposition and tubular damage. Furthermore, the serum levels of cytokines interleukin (IL)−2, IL‐4, IL‐6, IL‐10, IL‐17α, interferon (IFN)‐γ and tumour necrosis factor (TNF)‐α were increased significantly after Treg depletion in Bim–/– mice. This study demonstrates that transient depletion of Tregs leads to enhanced self‐reactive T effector cell function followed by exacerbation of kidney disease in the chronic spontaneous kidney disease model of Bim‐deficient mice. PMID:28152566

Behavioral effects of chronic stress in the Fmr1 mouse model for fragile X syndrome.

PubMed

Lemaire-Mayo, Valerie; Subashi, Enejda; Henkous, Nadia; Beracochea, Daniel; Pietropaolo, Susanna

2017-03-01

Fragile X Syndrome (FXS) is a pervasive developmental disorder due to a mutation in the FMR1 X-linked gene. Despite its clear genetic cause, the expression of FXS symptoms is known to be modulated by environmental factors, including stress. Furthermore, several studies have shown disturbances in stress regulatory systems in FXS patients and Fmr1 mice. These studies have mostly focused on the hormonal responses to stress, using the acute exposure to a single type of stressor. Hence, little is known about the behavioral effects of stress in FXS, and the importance of the nature of the stressing procedure, especially in the context of a repeated exposure that more closely resembles real life conditions. Here we evaluated the effects of chronic exposure to different types of stress (i.e., either repeated restraint or unpredictable stress) on the behavioral phenotype of adult Fmr1 mice. Our results demonstrated that chronic stress induced deficits in social interaction and working memory only in WT mice and the impact of stress depended on the type of stressors and the specific behavior tested. Our data suggest that the behavioral sensitivity to stress is dramatically reduced in FXS, opening new views on the impact of gene-environment interactions in this pathology. Copyright © 2016. Published by Elsevier B.V.

Simvastatin Attenuates Endothelial Activation through 15-Epi-Lipoxin A4 Production in Murine Chronic Chagas Cardiomyopathy.

PubMed

González-Herrera, Fabiola; Cramer, Allysson; Pimentel, Pollyana; Castillo, Christian; Liempi, Ana; Kemmerling, Ulrike; Machado, Fabiana S; Maya, Juan D

2017-03-01

Current treatments for chronic Chagas cardiomyopathy, a disease with high mortality rates and caused by the protozoan Trypanosoma cruzi , are unsatisfactory. Myocardial inflammation, including endothelial activation, is responsible for the structural and functional damage seen in the chronic phase. The clinical efficacy of benznidazole could be improved by decreasing chronic inflammation. Statins, which have anti-inflammatory properties, may improve the action of benznidazole. Here, the action of simvastatin in a murine model of chronic Chagas cardiomyopathy and the link with the production of the proresolving eicosanoid 15-epi-lipoxin A4, produced by 5-lipoxygenase, are evaluated. Simvastatin decreased the expression of the adhesion molecules E-selectin, intracellular adhesion molecule type 1 (ICAM-1), and vascular cell adhesion molecule type 1 (VCAM-1) in T. cruzi -infected mice. However, when this drug was administered to 5-lipoxygenase-deficient mice, the anti-inflammatory effect was not observed unless exogenous 15-epi-lipoxin A4 was administered. Thus, in chronic Chagas disease, 5-epi-lipoxin A4 induced by simvastatin treatment could improve the pathophysiological condition of patients by increasing the trypanocidal action of benznidazole. Copyright © 2017 American Society for Microbiology.

Development of an in vivo model of Chlamydia abortus chronic infection in mice overexpressing IL-10.

PubMed

Del Río, Laura; Murcia, Antonio; Buendía, Antonio J; Álvarez, Daniel; Ortega, Nieves; Navarro, José A; Salinas, Jesús; Caro, María Rosa

2018-01-01

Chlamydia abortus, like other members of the family Chlamydiaceae, have a unique intracellular developmental cycle that is characterized by its chronic nature. Infection of a flock can remain undetected for months, until abortion occurs the following reproductive season but, to date, neither the location nor the mechanisms that maintain this latent phase are fully understood. Studies have shown that IL-10 produced as a response to certain micro-organisms sustains the intracellular survival of pathogens and increases host susceptibility to chlamydial infections. In order to induce a sustained infection C. abortus, transgenic mice that constitutively express IL-10 were infected and the immunological mechanisms that maintain infection in these mice were compared with the mechanisms of a resistant wild-type mouse strain. Viable bacteria could be detected in different tissues of transgenic mice up to 28 days after infection, as analysed by bacterial isolation and immunohistochemistry. Chronic infection in these mice was associated with an impaired recruitment of macrophages, decreased iNOS activity at the site of infection and a more diffuse distribution of inflammatory cells in the liver. This murine model can be of great help for understanding the immunological and bacterial mechanisms that lead to chronic chlamydial infections. Copyright © 2017 Elsevier B.V. All rights reserved.

Up-regulation of nucleotide excision repair in mouse lung and liver following chronic exposure to aflatoxin B{sub 1} and its dependence on p53 genotype

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mulder, Jeanne E.; Bondy, Genevieve S.; Mehta, Rekha

Aflatoxin B{sub 1} (AFB{sub 1}) is biotransformed in vivo into an epoxide metabolite that forms DNA adducts that may induce cancer if not repaired. p53 is a tumor suppressor gene implicated in the regulation of global nucleotide excision repair (NER). Male heterozygous p53 knockout (B6.129-Trp53{sup tm1Brd}N5, Taconic) and wild-type mice were exposed to 0, 0.2 or 1.0 ppm AFB{sub 1} for 26 weeks. NER activity was assessed with an in vitro assay, using AFB{sub 1}-epoxide adducted plasmid DNA as a substrate. For wild-type mice, repair of AFB{sub 1}–N7-Gua adducts was 124% and 96% greater in lung extracts from mice exposedmore » to 0.2 ppm and 1.0 ppm AFB{sub 1} respectively, and 224% greater in liver extracts from mice exposed to 0.2 ppm AFB{sub 1} (p < 0.05). In heterozygous p53 knockout mice, repair of AFB{sub 1}–N7-Gua was only 45% greater in lung extracts from mice exposed to 0.2 ppm AFB{sub 1} (p < 0.05), and no effect was observed in lung extracts from mice treated with 1.0 ppm AFB{sub 1} or in liver extracts from mice treated with either AFB{sub 1} concentration. p53 genotype did not affect basal levels of repair. AFB{sub 1} exposure did not alter repair of AFB{sub 1}-derived formamidopyrimidine adducts in lung or liver extracts of either mouse genotype nor did it affect XPA or XPB protein levels. In summary, chronic exposure to AFB{sub 1} increased NER activity in wild-type mice, and this response was diminished in heterozygous p53 knockout mice, indicating that loss of one allele of p53 limits the ability of NER to be up-regulated in response to DNA damage. - Highlights: • Mice are chronically exposed to low doses of the mycotoxin aflatoxin B{sub 1} (AFB{sub 1}). • The effects of AFB{sub 1} and p53 status on nucleotide excision repair are investigated. • AFB{sub 1} increases nucleotide excision repair in wild type mouse lung and liver. • This increase is attenuated in p53 heterozygous mouse lung and liver. • Results portray the role of p53 in nucleotide excision repair after AFB{sub 1} exposure.« less

Characterization of the Impaired Glucose Homeostasis Produced in C57BL/6 Mice by Chronic Exposure to Arsenic and High-Fat Diet

PubMed Central

Paul, David S.; Walton, Felecia S.; Saunders, R. Jesse

2011-01-01

Background: Type 2 diabetes is characterized by glucose intolerance and insulin resistance. Obesity is the leading cause of type 2 diabetes. Growing evidence suggests that chronic exposure to inorganic arsenic (iAs) also produces symptoms consistent with diabetes. Thus, iAs exposure may further increase the risk of diabetes in obese individuals. Objectives: Our goal was to characterize diabetogenic effects of iAs exposure and high-fat diet (HFD) in weaned C57BL/6 mice. Methods: Mice were fed HFD or low-fat diet (LFD) while exposed to iAs in drinking water (25 or 50 ppm As) for 20 weeks; control HFD and LFD mice drank deionized water. Body mass and adiposity were monitored throughout the study. We measured glucose and insulin levels in fasting blood and in blood collected during oral glucose tolerance tests (OGTT) to evaluate the diabetogenic effects of the treatment. Results: Control mice fed HFD accumulated more fat, had higher fasting blood glucose, and were more insulin resistant than were control LFD mice. However, these diabetes indicators decreased with iAs intake in a dose-dependent manner. OGTT showed impaired glucose tolerance for both control and iAs-treated HFD mice compared with respective LFD mice. Notably, glucose intolerance was more pronounced in HFD mice treated with iAs despite a significant decrease in adiposity, fasting blood glucose, and insulin resistance. Conclusions: Our data suggest that iAs exposure acts synergistically with HFD-induced obesity in producing glucose intolerance. However, mechanisms of the diabetogenic effects of iAs exposure may differ from the mechanisms associated with the obesity-induced type 2 diabetes. PMID:21592922

Effect of treatment with cyclophosphamide in low doses upon the onset of delayed type hypersensitivity in mice chronically infected with Trypanosoma cruzi: involvement of heart interstitial dendritic cells.

PubMed

Thé, Torriceli Souza; Portella, Renata Siqueira; Guerreiro, Marcos Lázaro; Andrade, Sonia Gumes

2013-09-01

Acute infection with Trypanosoma cruzi results in intense myocarditis, which progresses to a chronic, asymptomatic indeterminate form. The evolution toward this chronic cardiac form occurs in approximately 30% of all cases of T. cruzi infection. Suppression of delayed type hypersensitivity (DTH) has been proposed as a potential explanation of the indeterminate form. We investigated the effect of cyclophosphamide (CYCL) treatment on the regulatory mechanism of DTH and the participation of heart interstitial dendritic cells (IDCs) in this process using BALB/c mice chronically infected with T. cruzi. One group was treated with CYCL (20 mg/kg body weight) for one month. A DTH skin test was performed by intradermal injection of T. cruzi antigen (3 mg/mL) in the hind-footpad and measured the skin thickness after 24 h, 48 h and 72 h. The skin test revealed increased thickness in antigen-injected footpads, which was more evident in the mice treated with CYCL than in those mice that did not receive treatment. The thickened regions were characterised by perivascular infiltrates and areas of necrosis. Intense lesions of the myocardium were present in three/16 cases and included large areas of necrosis. Morphometric evaluation of lymphocytes showed a predominance of TCD8 cells. Heart IDCs were immunolabelled with specific antibodies (CD11b and CD11c) and T. cruzi antigens were detected using a specific anti-T. cruzi antibody. Identification of T. cruzi antigens, sequestered in these cells using specific anti-T. cruzi antibodies was done, showing a significant increase in the number of these cells in treated mice. These results indicate that IDCs participate in the regulatory mechanisms of DTH response to T. cruzi infection.

Walnut phenolic extract inhibits nuclear factor kappaB signaling in intestinal epithelial cells, and ameliorates experimental colitis and colitis-associated colon cancer in mice.

PubMed

Koh, Seong-Joon; Choi, Youn-I; Kim, Yuri; Kim, Yoo-Sun; Choi, Sang Woon; Kim, Ji Won; Kim, Byeong Gwan; Lee, Kook Lae

2018-05-09

Walnuts (Juglans regia) are known to have anti-cancer and immunomodulatory effects. However, little information is available on the effects of walnut phenolic extract (WPE) on intestinal inflammation and colitis-associated colon cancer. COLO205 cells were pretreated with WPE and then stimulated with tumor necrosis factor (TNF)-α. In the acute colitis model, wild type mice (C57BL/6) were administered 4% dextran sulfate sodium (DSS) for 5 days. In the chronic colitis model, interleukin (IL)-10 -/- mice were administered with either the vehicle or WPE (20 mg/kg) by oral gavage daily for 2 weeks. In an inflammation-associated tumor model, wild type mice were administered a single intraperitoneal injection of azoxymethane followed by three cycles of 2% DSS for 5 days and 2 weeks of free water consumption. WPE significantly inhibited IL-8 and IL-1α expression in COLO205 cells. WPE attenuated both the TNF-α-induced IκB phosphorylation/degradation and NF-κB DNA binding activity. The administration of oral WPE significantly reduced the severity of colitis in both acute and chronic colitis models, including the IL-10 -/- mice. In immunohistochemical staining, WPE attenuated NF-κB signaling in the colons of both colitis models. Finally, WPE also significantly reduced tumor development in a murine model of colitis-associated colon cancer (CAC). WPE ameliorates acute and chronic colitis and CAC in mice, suggesting that WPE may have potentials for the treatment of inflammatory bowel disease.

A Novel ATM/TP53/p21-Mediated Checkpoint Only Activated by Chronic γ-Irradiation

PubMed Central

Sasatani, Megumi; Iizuka, Daisuke; Masuda, Yuji; Inaba, Toshiya; Suzuki, Keiji; Ootsuyama, Akira; Umata, Toshiyuki; Kamiya, Kenji; Suzuki, Fumio

2014-01-01

Different levels or types of DNA damage activate distinct signaling pathways that elicit various cellular responses, including cell-cycle arrest, DNA repair, senescence, and apoptosis. Whereas a range of DNA-damage responses have been characterized, mechanisms underlying subsequent cell-fate decision remain elusive. Here we exposed cultured cells and mice to different doses and dose rates of γ-irradiation, which revealed cell-type-specific sensitivities to chronic, but not acute, γ-irradiation. Among tested cell types, human fibroblasts were associated with the highest levels of growth inhibition in response to chronic γ-irradiation. In this context, fibroblasts exhibited a reversible G1 cell-cycle arrest or an irreversible senescence-like growth arrest, depending on the irradiation dose rate or the rate of DNA damage. Remarkably, when the same dose of γ-irradiation was delivered chronically or acutely, chronic delivery induced considerably more cellular senescence. A similar effect was observed with primary cells isolated from irradiated mice. We demonstrate a critical role for the ataxia telangiectasia mutated (ATM)/tumor protein p53 (TP53)/p21 pathway in regulating DNA-damage-associated cell fate. Indeed, blocking the ATM/TP53/p21 pathway deregulated DNA damage responses, leading to micronucleus formation in chronically irradiated cells. Together these results provide insights into the mechanisms governing cell-fate determination in response to different rates of DNA damage. PMID:25093836

Deletion of angiotensin II type 1 receptor gene or scavenge of superoxide prevents chronic alcohol-induced aortic damage and remodelling.

PubMed

Bai, Yang; Tan, Yi; Wang, Bo; Miao, Xiao; Chen, Qiang; Zheng, Yang; Cai, Lu

2012-10-01

To investigate whether chronic alcohol consumption induces vascular injury via angiotensin II (Ang II) type 1 (AT1) receptor-dependent superoxide generation, male transgenic mice with knockout of AT1 gene (AT1-KO) and age-matched wild-type (WT) C57BL/6 mice were pair-fed a modified Lieber-DeCarli alcohol or isocaloric maltose dextrin control liquid diet for 2 months. Ethanol content (%, W/V) in the diet was 4.8 (34% of total calories) at initiation, and gradually increased up to 5.4 (38% of total calories). For some WT mice with and without alcohol treatment, superoxide dismutase mimetic (MnTMPyP) was given simultaneously by intraperitoneal injection at 5 mg/kg body weight daily for 2 months. At the end of studies, aortas were harvested for histopathological and immunohistochemical examination. Significant increases in the wall thickness and structural disarrangement of aorta were found in alcohol group, along with significant increases in aortic oxidative and/or nitrosative damage, expressions of NADPH oxidases (NOXs), inflammatory response, cell death and proliferation, and remodelling (fibrosis). However, these pathological changes were completely attenuated in alcohol-treated AT1-KO mice or in alcohol-treated WT mice that were also simultaneously treated with MnTMPyP for 2 months. These results suggest that chronic alcohol consumption may activate NOX via Ang II/AT1 receptor, to generate superoxide and associated peroxynitrite that in turn causes aortic nitrosative damage, inflammation, cell death and proliferation, and remodelling. Therefore, blocking Ang II/AT1 system or scavenging superoxide may become a potential preventive and/therapeutic approach to alcoholic vascular damage. © 2012 The Authors Journal of Cellular and Molecular Medicine © 2012 Foundation for Cellular and Molecular Medicine/Blackwell Publishing Ltd.

GM-CSF modulates autoantibody production and skin blistering in experimental epidermolysis bullosa acquisita.

PubMed

Samavedam, Unni Krishna S R L; Iwata, Hiroaki; Müller, Susen; Schulze, Franziska S; Recke, Andreas; Schmidt, Enno; Zillikens, Detlef; Ludwig, Ralf J

2014-01-15

GM-CSF activates hematopoietic cells and recruits neutrophils and macrophages to sites of inflammation. Inhibition of GM-CSF attenuates disease activity in models of chronic inflammatory disease. Effects of GM-CSF blockade were linked to modulation of the effector phase, whereas effects on early pathogenic events, for example, Ab production, have not been identified. To evaluate yet uncharacterized effects of GM-CSF on early pathogenic events in chronic inflammation, we employed immunization-induced epidermolysis bullosa acquisita (EBA), an autoimmune bullous disease caused by autoantibodies to type VII collagen. Compared to wild-type mice, upon immunization, GM-CSF(-/-) mice produced lower serum autoantibody titers, which were associated with reduced neutrophil numbers in draining lymph nodes. The same effect was observed in neutrophil-depleted wild-type mice. Neutrophil depletion in GM-CSF(-/-) mice led to a stronger inhibition, indicating that GM-CSF and neutrophils have additive functions. To characterize the contribution of GM-CSF specifically in the effector phase of EBA, disease was induced by transfer of anti-type VII collagen IgG into mice. We observed an increased GM-CSF expression, and GM-CSF blockade reduced skin blistering. Additionally, GM-CSF enhanced reactive oxygen species release and neutrophil migration in vitro. In immunization-induced murine EBA, treatment with anti-GM-CSF had a beneficial effect on established disease. We demonstrate that GM-CSF modulates both autoantibody production and skin blistering in a prototypical organ-specific autoimmune disease.

Chronic Metabolic Acidosis Activates Renal Tubular Sodium Chloride Cotransporter through Angiotension II-dependent WNK4-SPAK Phosphorylation Pathway

PubMed Central

Fang, Yu-Wei; Yang, Sung-Sen; Cheng, Chih-Jen; Tseng, Min-Hua; Hsu, Hui-Min; Lin, Shih-Hua

2016-01-01

The mechanism by which chronic metabolic acidosis (CMA) regulates sodium (Na+)-chloride (Cl−) cotransporter (NCC) in the renal distal convoluted tubules remains unexplored. We examined the role of STE20/SPS1-related proline/alanine-rich kinase (SPAK) and with-no-lysine kinase 4 (WNK4) on expression of NCC in mouse models of CMA. CMA was induced by NH4Cl in wild type mice (WTA mice), SPAK, and WNK4 knockout mice. The quantities of Ncc mRNA, expression of total NCC, phosphorylated (p)-NCC, SPAK and WNK4 in the kidneys as well as NCC inhibition with hydrochlorothiazide and Na+ balance were evaluated. Relative to WT mice, WTA mice had similar levels of Ncc mRNA, but increased expression of total and p-NCC, SPAK, and WNK4 and an exaggerated response to hydrochlorothiazide which could not be observed in SPAK or WNK4 knockout mice with CMA. In WTA mice, increased plasma renin activity, aldosterone and angiotensin II concentrations accompanied by a significantly negative Na+ balance. High Na+ diet abolished the enhanced NCC expression in WTA mice. Furthermore, an angiotensin II type 1 receptor blocker rather than a mineralocorticoid receptor antagonist exerted a marked inhibition on Na+ reabsorption and NCC phosphorylation in WTA mice. CMA increases WNK4-SPAK-dependent NCC phosphorylation and appears to be secondary to previous natriuresis with volume-dependent angiotensin II activation. PMID:26728390

Regulation of inflammation-associated olfactory neuronal death and regeneration by the type II tumor necrosis factor receptor.

PubMed

Pozharskaya, Tatyana; Liang, Jonathan; Lane, Andrew P

2013-09-01

Olfactory loss is a debilitating symptom of chronic rhinosinusitis. To study the impact of inflammation on the olfactory system, the inducible olfactory inflammation (IOI) transgenic mouse was created in which inflammation can be turned on and off within the olfactory epithelium. In this study, the type II tumor necrosis factor (TNF) receptor (TNFR2) was knocked out, and the effect on the olfactory loss phenotype was assessed. IOI mice were bred to TNFR2 knockout mice to yield progeny IOI mice lacking the TNFR2 receptor (TNFR2(-/-) ). TNF-α expression was induced within the olfactory epithelium for 6 weeks to generate chronic inflammation. Olfactory function was assayed by electro-olfactogram (EOG), and olfactory tissue was processed for histology and immunohistochemical staining. Compared to IOI mice with wild-type TNFR2, IOI mice lacking the TNFR2 demonstrated similar levels of inflammatory infiltration and enlargement of the subepithelial layer. However, IOI-TNFR2(-/-) mice differed markedly in that the neuronal layer was largely preserved and active progenitor cell proliferation was present. Odorant responses were maintained in the IOI-TNFR2(-/-) mice, in contrast to IOI mice. TNFR2 is the minor receptor for TNF-α, but appears to play an important role in mediating TNF-induced disruption of the olfactory system. This finding suggests that neuronal death and inhibition of proliferation in CRS may be mediated by TNFR2 on olfactory neurons and progenitor cells. Further studies are needed to elucidate the subcellular pathways involved and develop novel therapies for treating olfactory loss in the setting of CRS. © 2013 ARS-AAOA, LLC.

Chronic Pelvic Pain Development and Prostate Inflammation in Strains of Mice With Different Susceptibility to Experimental Autoimmune Prostatitis.

PubMed

Breser, Maria L; Motrich, Ruben D; Sanchez, Leonardo R; Rivero, Virginia E

2017-01-01

Experimental autoimmune prostatitis (EAP) is an autoimmune inflammatory disease of the prostate characterized by peripheral prostate-specific autoimmune responses associated with prostate inflammation. EAP is induced in rodents upon immunization with prostate antigens (PAg) plus adjuvants and shares important clinical and immunological features with the human disease chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS). EAP was induced in young NOD, C57BL/6, and BALB/c male mice by immunization with PAg plus complete Freund́s adjuvant. Tactile allodynia was assessed using Von Frey fibers as a measure of pelvic pain at baseline and at different time points after immunization. Using conventional histology, immunohistochemistry, FACS analysis, and protein arrays, an interstrain comparative study of prostate cell infiltration and inflammation was performed. Chronic pelvic pain development was similar between immunized NOD and C57BL/6 mice, although the severity of leukocyte infiltration was greater in the first case. Coversely, minimal prostate cell infiltration was observed in immunized BALB/c mice, who showed no pelvic pain development. Increased numbers of mast cells, mostly degranulated, were detected in prostate samples from NOD and C57BL/6 mice, while lower total counts and resting were observed in BALB/c mice. Prostate tissue from NOD mice revealed markedly increased expression levels of inflammatory cytokines, chemokines, adhesion molecules, vascular endothelial growth factor, and metalloproteinases. Similar results, but to a lesser extent, were observed when analyzing prostate tissue from C57BL/6 mice. On the contrary, the expression of the above mediators was very low in prostate tissue from immunized BALB/c mice, showing significantly slight increments only for CXCL1 and IL4. Our results provide new evidence indicating that NOD, C57BL/6, and BALB/c mice develop different degrees of chronic pelvic pain, type, and amount of prostate cell infiltration and secretion of inflammatory mediators. Our results corroborate and support the notion that mice with different genetic background have different susceptibility to EAP induction. Prostate 77:94-104, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Phosphodiesterase-1b (Pde1b) knockout mice are resistant to forced swim and tail suspension induced immobility and show upregulation of Pde10a.

PubMed

Hufgard, Jillian R; Williams, Michael T; Skelton, Matthew R; Grubisha, Olivera; Ferreira, Filipa M; Sanger, Helen; Wright, Mary E; Reed-Kessler, Tracy M; Rasmussen, Kurt; Duman, Ronald S; Vorhees, Charles V

2017-06-01

Major depressive disorder is a leading cause of suicide and disability. Despite this, current antidepressants provide insufficient efficacy in more than 60% of patients. Most current antidepressants are presynaptic reuptake inhibitors; postsynaptic signal regulation has not received as much attention as potential treatment targets. We examined the effects of disruption of the postsynaptic cyclic nucleotide hydrolyzing enzyme, phosphodiesterase (PDE) 1b, on depressive-like behavior and the effects on PDE1B protein in wild-type (WT) mice following stress. Littermate knockout (KO) and WT mice were tested in locomotor activity, tail suspension (TST), and forced swim tests (FST). FST was also used to compare the effects of two antidepressants, fluoxetine and bupropion, in KO versus WT mice. Messenger RNA (mRNA) expression changes were also determined. WT mice underwent acute or chronic stress and markers of stress and PDE1B expression were examined. Pde1b KO mice exhibited decreased TST and FST immobility. When treated with antidepressants, both WT and KO mice showed decreased FST immobility and the effect was additive in KO mice. Mice lacking Pde1b had increased striatal Pde10a mRNA expression. In WT mice, acute and chronic stress upregulated PDE1B expression while PDE10A expression was downregulated after chronic but not acute stress. PDE1B is a potential therapeutic target for depression treatment because of the antidepressant-like phenotype seen in Pde1b KO mice.

Exacerbation of spontaneous autoimmune nephritis following regulatory T cell depletion in B cell lymphoma 2-interacting mediator knock-out mice.

PubMed

Wang, Y M; Zhang, G Y; Wang, Y; Hu, M; Zhou, J J; Sawyer, A; Cao, Q; Wang, Y; Zheng, G; Lee, V W S; Harris, D C H; Alexander, S I

2017-05-01

Regulatory T cells (T regs ) have been recognized as central mediators for maintaining peripheral tolerance and limiting autoimmune diseases. The loss of T regs or their function has been associated with exacerbation of autoimmune disease. However, the temporary loss of T regs in the chronic spontaneous disease model has not been investigated. In this study, we evaluated the role of T regs in a novel chronic spontaneous glomerulonephritis model of B cell lymphoma 2-interacting mediator (Bim) knock-out mice by transient depleting T regs . Bim is a pro-apoptotic member of the B cell lymphoma 2 (Bcl-2) family. Bim knock-out (Bim -/- ) mice fail to delete autoreactive T cells in thymus, leading to chronic spontaneous autoimmune kidney disease. We found that T reg depletion in Bim -/- mice exacerbated the kidney injury with increased proteinuria, impaired kidney function, weight loss and greater histological injury compared with wild-type mice. There was a significant increase in interstitial infiltrate of inflammatory cells, antibody deposition and tubular damage. Furthermore, the serum levels of cytokines interleukin (IL)-2, IL-4, IL-6, IL-10, IL-17α, interferon (IFN)-γ and tumour necrosis factor (TNF)-α were increased significantly after T reg depletion in Bim -/- mice. This study demonstrates that transient depletion of T regs leads to enhanced self-reactive T effector cell function followed by exacerbation of kidney disease in the chronic spontaneous kidney disease model of Bim-deficient mice. © 2017 British Society for Immunology.

Exposure to excess insulin (glargine) induces type 2 diabetes mellitus in mice fed on a chow diet.

PubMed

Yang, Xuefeng; Mei, Shuang; Gu, Haihua; Guo, Huailan; Zha, Longying; Cai, Junwei; Li, Xuefeng; Liu, Zhenqi; Cao, Wenhong

2014-06-01

We have previously shown that insulin plays an important role in the nutrient-induced insulin resistance. In this study, we tested the hypothesis that chronic exposure to excess long-acting insulin (glargine) can cause typical type 2 diabetes mellitus (T2DM) in normal mice fed on a chow diet. C57BL/6 mice were treated with glargine once a day for 8 weeks, followed by evaluations of food intake, body weight, blood levels of glucose, insulin, lipids, and cytokines, insulin signaling, histology of pancreas, ectopic fat accumulation, oxidative stress level, and cholesterol content in mitochondria in tissues. Cholesterol content in mitochondria and its association with oxidative stress in cultured hepatocytes and β-cells were also examined. Results show that chronic exposure to glargine caused insulin resistance, hyperinsulinemia, and relative insulin deficiency (T2DM). Treatment with excess glargine led to loss of pancreatic islets, ectopic fat accumulation in liver, oxidative stress in liver and pancreas, and increased cholesterol content in mitochondria of liver and pancreas. Prolonged exposure of cultured primary hepatocytes and HIT-TI5 β-cells to insulin induced oxidative stress in a cholesterol synthesis-dependent manner. Together, our results show that chronic exposure to excess insulin can induce typical T2DM in normal mice fed on a chow diet. © 2014 The authors.

Sex Differences in Ethanol's Anxiolytic Effect and Chronic Ethanol Withdrawal Severity in Mice with a Null Mutation of the 5α-Reductase Type 1 Gene.

PubMed

Tanchuck-Nipper, Michelle A; Ford, Matthew M; Hertzberg, Anna; Beadles-Bohling, Amy; Cozzoli, Debra K; Finn, Deborah A

2015-05-01

Manipulation of endogenous levels of the GABAergic neurosteroid allopregnanolone alters sensitivity to some effects of ethanol. Chronic ethanol withdrawal decreases activity and expression of 5α-reductase-1, an important enzyme in allopregnanolone biosynthesis encoded by the 5α-reductase-1 gene (Srd5a1). The present studies examined the impact of Srd5a1 deletion in male and female mice on several acute effects of ethanol and on chronic ethanol withdrawal severity. Genotype and sex did not differentially alter ethanol-induced hypothermia, ataxia, hypnosis, or metabolism, but ethanol withdrawal was significantly lower in female versus male mice. On the elevated plus maze, deletion of the Srd5a1 gene significantly decreased ethanol's effect on total entries versus wildtype (WT) mice and significantly decreased ethanol's anxiolytic effect in female knockout (KO) versus WT mice. The limited sex differences in the ability of Srd5a1 genotype to modulate select ethanol effects may reflect an interaction between developmental compensations to deletion of the Srd5a1 gene with sex hormones and levels of endogenous neurosteroids.

Sex Differences in Ethanol’s Anxiolytic Effect and Chronic Ethanol Withdrawal Severity in Mice With a Null Mutation of the 5α-Reductase Type 1 Gene

PubMed Central

Tanchuck-Nipper, Michelle A.; Ford, Matthew M.; Hertzberg, Anna; Beadles-Bohling, Amy; Cozzoli, Debra K.; Finn, Deborah A.

2015-01-01

Manipulation of endogenous levels of the GABAergic neurosteroid allopregnanolone alters sensitivity to some effects of ethanol. Chronic ethanol withdrawal decreases activity and expression of 5α-reductase-1, an important enzyme in allopregnanolone biosynthesis encoded by the 5α-reductase-1 gene (Srd5a1). The present studies examined the impact of Srd5a1 deletion in male and female mice on several acute effects of ethanol and on chronic ethanol withdrawal severity. Genotype and sex did not differentially alter ethanol-induced hypothermia, ataxia, hypnosis, or metabolism, but ethanol withdrawal was significantly lower in female versus male mice. On the elevated plus maze, deletion of the Srd5a1 gene significantly decreased ethanol’s effect on total entries versus wildtype (WT) mice and significantly decreased ethanol’s anxiolytic effect in female knockout (KO) versus WT mice. The limited sex differences in the ability of Srd5a1 genotype to modulate select ethanol effects may reflect an interaction between developmental compensations to deletion of the Srd5a1 gene with sex hormones and levels of endogenous neurosteroids. PMID:25355320

Role of adiponectin in the metabolic effects of cannabinoid type 1 receptor blockade in mice with diet-induced obesity

PubMed Central

Godlewski, Grzegorz; Earley, Brian J.; Zhou, Liang; Jourdan, Tony; Szanda, Gergö; Cinar, Resat; Kunos, George

2013-01-01

The adipocyte-derived hormone adiponectin promotes fatty acid oxidation and improves insulin sensitivity and thus plays a key role in the regulation of lipid and glucose metabolism and energy homeostasis. Chronic cannabinoid type 1 (CB1) receptor blockade also increases lipid oxidation and improves insulin sensitivity in obese individuals or animals, resulting in reduced cardiometabolic risk. Chronic CB1 blockade reverses the obesity-related decline in serum adiponectin levels, which has been proposed to account for the metabolic effects of CB1 antagonists. Here, we investigated the metabolic actions of the CB1 inverse agonist rimonabant in high-fat diet (HFD)-induced obese adiponectin knockout (Adipo−/−) mice and their wild-type littermate controls (Adipo+/+). HFD-induced obesity and its hormonal/metabolic consequences were indistinguishable in the two strains. Daily treatment of obese mice with rimonabant for 7 days resulted in significant and comparable reductions in body weight, serum leptin, free fatty acid, cholesterol, and triglyceride levels in the two strains. Rimonabant treatment improved glucose homeostasis and insulin sensitivity to the same extent in Adipo+/+ and Adipo−/− mice, whereas it reversed the HFD-induced hepatic steatosis, fibrosis, and hepatocellular damage only in the former. The adiponectin-dependent, antisteatotic effect of rimonabant was mediated by reduced uptake and increased β-oxidation of fatty acids in the liver. We conclude that reversal of the HFD-induced hepatic steatosis and fibrosis by chronic CB1 blockade, but not the parallel reduction in adiposity and improved glycemic control, is mediated by adiponectin. PMID:24381003

Sleep apneas are increased in mice lacking monoamine oxidase A.

PubMed

Real, Caroline; Popa, Daniela; Seif, Isabelle; Callebert, Jacques; Launay, Jean-Marie; Adrien, Joëlle; Escourrou, Pierre

2007-10-01

Alterations in the serotonin (5-HT) system have been suggested as a mechanism of sleep apnea in humans and rodents. The objective is to evaluate the contribution of 5-HT to this disorder. We studied sleep and breathing (whole-body plethysmography) in mutant mice that lack monoamine oxidase A (MAOA) and have increased concentrations of monoamines, including 5-HT. Compared to wild-type mice, the mutants showed similar amounts of slow wave sleep (SWS) and rapid eye movement sleep (REMS), but exhibited a 3-fold increase in SWS and REMS apnea indices. Acute administration of the MAOA inhibitor clorgyline decreased REMS amounts and increased the apnea index in wild-type but not mutant mice. Parachlorophenylalanine, a 5-HT synthesis inhibitor, reduced whole brain concentrations of 5-HT in both strains, and induced a decrease in apnea index in mutant but not wild-type mice. Our results show that MAOA deficiency is associated with increased sleep apnea in mice and suggest that an acute or chronic excess of 5-HT contributes to this phenotype.

A platelet-activating factor (PAF) receptor deficiency exacerbates diet-induced obesity but PAF/PAF receptor signaling does not contribute to the development of obesity-induced chronic inflammation.

PubMed

Yamaguchi, Masahiko; Matsui, Masakazu; Higa, Ryoko; Yamazaki, Yasuhiro; Ikari, Akira; Miyake, Masaki; Miwa, Masao; Ishii, Satoshi; Sugatani, Junko; Shimizu, Takao

2015-02-15

Platelet-activating factor (PAF) is a well-known phospholipid that mediates acute inflammatory responses. In the present study, we investigated whether PAF/PAF receptor signaling contributed to chronic inflammation in the white adipose tissue (WAT) of PAF receptor-knockout (PAFR-KO) mice. Body and epididymal WAT weights were higher in PAFR-KO mice fed a high-fat diet (HFD) than in wild-type (WT) mice. TNF-α mRNA expression levels in epididymal WAT and the infiltration of CD11c-positive macrophages into epididymal WAT, which led to chronic inflammation, were also elevated in HFD-fed PAFR-KO mice. HFD-fed PAFR-KO mice had higher levels of fasting serum glucose than HFD-fed WT mice as well as impaired glucose tolerance. Although PAF receptor signaling up-regulated the expression of TNF-α and lipopolysaccharide induced the expression of acyl-CoA:lysophosphatidylcholine acyltransferase 2 (LPCAT2) mRNA in bone marrow-derived macrophages, no significant differences were observed in the expression of LPCAT2 mRNA and PAF levels in epididymal WAT between HFD-fed mice and normal diet-fed mice. In addition to our previous finding in which energy expenditure in PAF receptor (PAFR)-deficient mice was low due to impaired brown adipose tissue function, the present study demonstrated that PAF/PAF receptor signaling up-regulated the expression of Ucp1 mRNA, which is essential for cellular thermogenesis, in 3T3-L1 adipocytes. We concluded that the marked accumulation of abdominal fat due to HFD feeding led to more severe chronic inflammation in WAT, which is associated with glucose metabolism disorders, in PAFR-KO mice than in WT mice, and PAF/PAF receptor signaling may regulate energy expenditure and adiposity. Copyright © 2015 Elsevier Inc. All rights reserved.

Dendritic cells and anergic type I NKT cells play a crucial role in sulfatide-mediated immune regulation in experimental autoimmune encephalomyelitis

PubMed Central

Maricic, Igor; Halder, Ramesh; Bischof, Felix; Kumar, Vipin

2014-01-01

CD1d-restricted NKT cells can be divided into two groups: type I NKT cells utilize a semi-invariant TCR whereas type II express a relatively diverse set of TCRs. A major subset of type II NKT cells recognizes myelin-derived sulfatides and is selectively enriched in the central nervous system tissue during experimental autoimmune encephalomyelitis (EAE). We have shown that activation of sulfatide-reactive type II NKT cells by sulfatide prevents induction of EAE. Here we have addressed the mechanism of regulation as well as whether a single immunodominant form of synthetic sulfatide can treat ongoing chronic and relapsing EAE in SJL/J mice. We have shown that the activation of sulfatide-reactive type II NKT cells leads to a significant reduction in the frequency and effector function of PLP139-151/I-As–tetramer+ cells in lymphoid and CNS tissues. In addition, type I NKT cells and dendritic cells in the periphery as well as CNS-resident microglia are inactivated following sulfatide administration, and mice deficient in type I NKT cells are not protected from disease. Moreover tolerized DCs from sulfatide-treated animals can adoptively transfer protection into naive mice. Treatment of SJL/J mice with a synthetic cis-tetracosenoyl sulfatide, but not αGalCer, reverses ongoing chronic and relapsing EAE. Our data highlight a novel immune regulatory pathway involving NKT subset interactions leading to inactivation of type I NKT cells, DCs, and microglial cells in suppression of autoimmunity. Since CD1 molecules are non-polymorphic, the sulfatide-mediated immune regulatory pathway can be targeted for development of non-HLA-dependent therapeutic approaches to T cell-mediated autoimmune diseases. PMID:24973441

Mice lacking the serotonin 5-HT2B receptor as an animal model of resistance to selective serotonin reuptake inhibitors antidepressants.

PubMed

Diaz, Silvina Laura; Narboux-Nême, Nicolas; Boutourlinsky, Katia; Doly, Stéphane; Maroteaux, Luc

2016-02-01

Depressive disorders are among the most prevalent neuropsychiatric dysfunctions worldwide, with high rates of resistance to antidepressant treatment. Genetic factors clearly contribute to the manifestation of depression as well as to the response to antidepressants. Transgenic mouse models appear as seminal tools to disentangle this complex disorder. Here, we analyzed new key aspects of the phenotype of knock-out mice for the gene encoding the serotonin 2B receptor (Htr(2B)(-/-)), including basal phenotype, ability to develop a depressive-like phenotype upon chronic isolation, and effect of chronic exposure to fluoxetine on chronically stressed Htr(2B)(-/-) mice. We find, here, that Htr(2B)(-/-) mice display an antidepressant-like phenotype, which includes reduced latency to feed in the novelty suppressed feeding test, basal increase in hippocampal BDNF levels, no change in TrkB and p75 protein levels, and an increased preference for sucrose consumption compared to wild type (Htr(2B)(+/+)) mice. Nevertheless, we show that these mice can develop depressive-like behaviors when socially isolated during four weeks. Selective serotonin reuptake inhibitors (SSRI) have been previously shown to be ineffective in non-stressed Htr(2B)(-/-) mice. We evaluated, here, the effects of the SSRI fluoxetine in chronically stressed Htr(2B)(-/-) mice and similarly no behavioral or plastic effect was induced by this antidepressant. All together, these results highlight the suitability to study resistance to SSRI antidepressants of this mouse model displaying panoply of conditions among which behavioral, neurotrophic and plastic causative factors can be analyzed. Copyright © 2015 Elsevier B.V. and ECNP. All rights reserved.

Sphingosine kinase 2-deficiency mediated changes in spinal pain processing.

PubMed

Canlas, Jastrow; Holt, Phillip; Carroll, Alexander; Rix, Shane; Ryan, Paul; Davies, Lorena; Matusica, Dusan; Pitson, Stuart M; Jessup, Claire F; Gibbins, Ian L; Haberberger, Rainer V

2015-01-01

Chronic pain is one of the most burdensome health issues facing the planet (as costly as diabetes and cancer combined), and in desperate need for new diagnostic targets leading to better therapies. The bioactive lipid sphingosine 1-phosphate (S1P) and its receptors have recently been shown to modulate nociceptive signaling at the level of peripheral nociceptors and central neurons. However, the exact role of S1P generating enzymes, in particular sphingosine kinase 2 (Sphk2), in nociception remains unknown. We found that both sphingosine kinases, Sphk1 and Sphk2, were expressed in spinal cord (SC) with higher levels of Sphk2 mRNA compared to Sphk1. All three Sphk2 mRNA-isoforms were present with the Sphk2.1 mRNA showing the highest relative expression. Mice deficient in Sphk2 (Sphk2(-/-)) showed in contrast to mice deficient in Sphk1 (Sphk1(-/-)) substantially lower spinal S1P levels compared to wild-type C57BL/6 mice. In the formalin model of acute peripheral inflammatory pain, Sphk2(-/-) mice showed facilitation of nociceptive transmission during the late response, whereas responses to early acute pain, and the number of c-Fos immunoreactive dorsal horn neurons were not different between Sphk2(-/-) and wild-type mice. Chronic peripheral inflammation (CPI) caused a bilateral increase in mechanical sensitivity in Sphk2(-/-) mice. Additionally, CPI increased the relative mRNA expression of P2X4 receptor, brain-derived neurotrophic factor and inducible nitric oxide synthase in the ipsilateral SC of wild-type but not Sphk2(-/-) mice. Similarly, Sphk2(-/-) mice showed in contrast to wild-type no CPI-dependent increase in areas of the dorsal horn immunoreactive for the microglia marker Iba-1 and the astrocyte marker Glial fibrillary acidic protein (GFAP). Our results suggest that the tightly regulated cell signaling enzyme Sphk2 may be a key component for facilitation of nociceptive circuits in the CNS leading to central sensitization and pain memory formation.

Knockout of the norepinephrine transporter and pharmacologically diverse antidepressants prevent behavioral and brain neurotrophin alterations in two chronic stress models of depression.

PubMed

Haenisch, Britta; Bilkei-Gorzo, Andras; Caron, Marc G; Bönisch, Heinz

2009-10-01

Diverse factors such as changes in neurotrophins and brain plasticity have been proposed to be involved in the actions of antidepressant drugs (ADs). However, in mouse models of depression based on chronic stress, it is still unclear whether simultaneous changes in behavior and neurotrophin expression occur and whether these changes can be corrected or prevented comparably by chronic administration of ADs or genetic manipulations that produce antidepressant-like effects such as the knockout of the norepinephrine transporter (NET) gene. Here we show that chronic restraint or social defeat stress induce comparable effects on behavior and changes in the expression of neurotrophins in depression-related brain regions. Chronic stress caused down-regulation of BDNF, nerve growth factor, and neurotrophin-3 in hippocampus and cerebral cortex and up-regulation of these targets in striatal regions. In wild-type mice, these effects could be prevented by concomitant chronic administration of five pharmacologically diverse ADs. In contrast, NET knock out (NETKO) mice were resistant to stress-induced depressive-like changes in behavior and brain neurotrophin expression. Thus, the resistance of the NETKO mice to the stress-induced depression-associated behaviors and biochemical changes highlight the importance of noradrenergic pathways in the maintenance of mood. In addition, these mice represent a useful model to study depression-resistant behaviors, and they might help to provide deeper insights into the identification of downstream targets involved in the mechanisms of antidepressants.

The effects of reduced dopamine transporter function and chronic lithium on motivation, probabilistic learning, and neurochemistry in mice: Modeling bipolar mania.

PubMed

Milienne-Petiot, Morgane; Kesby, James P; Graves, Mary; van Enkhuizen, Jordy; Semenova, Svetlana; Minassian, Arpi; Markou, Athina; Geyer, Mark A; Young, Jared W

2017-02-01

Bipolar disorder (BD) mania patients exhibit poor cognition and reward-seeking/hypermotivation, negatively impacting a patient's quality of life. Current treatments (e.g., lithium), do not treat such deficits. Treatment development has been limited due to a poor understanding of the neural mechanisms underlying these behaviors. Here, we investigated putative mechanisms underlying cognition and reward-seeking/motivational changes relevant to BD mania patients using two validated mouse models and neurochemical analyses. The effects of reducing dopamine transporter (DAT) functioning via genetic (knockdown vs. wild-type littermates), or pharmacological (GBR12909- vs. vehicle-treated C57BL/6J mice) means were assessed in the probabilistic reversal learning task (PRLT), and progressive ratio breakpoint (PRB) test, during either water or chronic lithium treatment. These tasks quantify reward learning and effortful motivation, respectively. Neurochemistry was performed on brain samples of DAT mutants ± chronic lithium using high performance liquid chromatography. Reduced DAT functioning increased reversals in the PRLT, an effect partially attenuated by chronic lithium. Chronic lithium alone slowed PRLT acquisition. Reduced DAT functioning increased motivation (PRB), an effect attenuated by lithium in GBR12909-treated mice. Neurochemical analyses revealed that DAT knockdown mice exhibited elevated homovanillic acid levels, but that lithium had no effect on these elevated levels. Reducing DAT functioning recreates many aspects of BD mania including hypermotivation and improved reversal learning (switching), as well as elevated homovanillic acid levels. Chronic lithium only exerted main effects, impairing learning and elevating norepinephrine and serotonin levels of mice, not specifically treating the underlying mechanisms identified in these models. Copyright © 2016 Elsevier Ltd. All rights reserved.

ARGININOSUCCINATE SYNTHASE CONDITIONS THE RESPONSE TO ACUTE AND CHRONIC ETHANOL-INDUCED LIVER INJURY IN MICE

PubMed Central

Yan, Wei; Morón-Concepción, Jose A.; Ward, Stephen C.; Ge, Xiaodong; de la Rosa, Laura Conde; Nieto, Natalia

2012-01-01

Background and Aim Argininosuccinate synthase (ASS) is the rate-limiting enzyme in both the urea and the l-citrulline/nitric oxide (NO·) cycles regulating protein catabolism, ammonia levels and NO· generation (1-2). Since a proteomics analysis identified ASS and nitric oxide synthase-2 (NOS2) as co-induced in rat hepatocytes by chronic ethanol consumption, which also occurred in alcoholic liver disease (ALD) and in cirrhotic patients, we hypothesized that ASS could play a role in ethanol binge and chronic ethanol-induced liver damage. Methods To investigate the contribution of ASS to the pathophysiology of ALD, wild-type (WT) and Ass+/− mice (Ass−/− are lethal due to hyperammonemia) were exposed to an ethanol binge or to chronic ethanol drinking. Results Compared with WT, Ass+/− mice given an ethanol binge exhibited decreased steatosis, lower NOS2 induction and less 3-nitrotyrosine (3-NT) protein residues, indicating that reducing nitrosative stress via the l-citrulline/NO· pathway plays a significant role in preventing liver damage. However, chronic ethanol treated Ass+/− mice displayed enhanced liver injury compared with WT mice. This was due to hyperammonemia, lower phosphorylated AMP-activated protein kinase (pAMPKα) to total AMPKα ratio, decreased sirtuin (Sirt-1) and peroxisomal proliferator-activated receptor coactivator-1α (Pgc1α) mRNAs, lower fatty acid β-oxidation due to down-regulation of carnitine palmitoyl transferase-II (CPT-II), decreased antioxidant defense and elevated lipid peroxidation end-products in spite of comparable nitrosative stress but likely reduced NOS3. Conclusion Partial Ass ablation protects only in acute ethanol-induced liver injury by decreasing nitrosative stress but not in a more chronic scenario where oxidative stress and impaired fatty acid β-oxidation are key events. PMID:22213272

Regulation of ethanol intake under chronic mild stress: roles of dopamine receptors and transporters.

PubMed

Delis, Foteini; Rombola, Christina; Bellezza, Robert; Rosko, Lauren; Grandy, David K; Volkow, Nora D; Thanos, Panayotis K

2015-01-01

Studies have shown that exposure to chronic mild stress decreases ethanol intake and preference in dopamine D2 receptor wild-type mice (Drd2 (+/+)), while it increases intake in heterozygous (Drd2 (+/-)) and knockout (Drd2 (-/-)) mice. Dopaminergic neurotransmission in the basal forebrain plays a major role in the reinforcing actions of ethanol as well as in brain responses to stress. In order to identify neurochemical changes associated with the regulation of ethanol intake, we used in vitro receptor autoradiography to measure the levels and distribution of dopamine D1 and D2 receptors and dopamine transporters (DAT). Receptor levels were measured in the basal forebrain of Drd2 (+/+), Drd2 (+/-), and Drd2 (-/-) mice belonging to one of four groups: control (C), ethanol intake (E), chronic mild stress exposure (S), and ethanol intake under chronic mild stress (ES). D2 receptor levels were higher in the lateral and medial striatum of Drd2 (+/+) ES mice, compared with Drd2 (+/+) E mice. Ethanol intake in Drd2 (+/+) mice was negatively correlated with striatal D2 receptor levels. D2 receptor levels in Drd2(+/-) mice were the same among the four treatment groups. DAT levels were lower in Drd2(+/-) C and Drd2 (-/-) C mice, compared with Drd2 (+/+) C mice. Among Drd2(+/-) mice, S and ES groups had higher DAT levels compared with C and E groups in most regions examined. In Drd2(-/-) mice, ethanol intake was positively correlated with DAT levels in all regions studied. D1 receptor levels were lower in Drd2(+/-) and Drd2(-/-) mice, compared with Drd2(+/+), in all regions examined and remained unaffected by all treatments. The results suggest that in normal mice, ethanol intake is associated with D2 receptor-mediated neurotransmission, which exerts a protective effect against ethanol overconsumption under stress. In mice with low Drd2 expression, where DRD2 levels are not further modulated, ethanol intake is associated with DAT function which is upregulated under stress leading to ethanol overconsumption.

Effect of Shenxinning decoction on ventricular remodeling in AT1 receptor-knockout mice with chronic renal insufficiency.

PubMed

Yang, Xuejun; Zhou, Hua; Qu, Huiyan; Liu, Weifang; Huang, Xiaojin; Shun, Yating; He, Liqun

2014-01-01

To observe the efficacy of Shenxinning Decoction (SXND) in ventricular remodeling in AT1 receptor-knockout (AT1-KO) mice with chronic renal insufficiency (CRI). AT1-KO mice modeled with subtotal (5/6) nephrectomy were intervened with SXND for 12 weeks. Subsequently, blood urea nitrogen (BUN), serum creatinine (SCr), brain natriuretic peptide (BNP), echocardiography (left ventricular end-diastolic diameter, LVDD; left ventricular end-systolic diameter, LVDS; fractional shortening, FS; and ejection fraction, EF), collagen types I and III in the heart and kidney, myocardial mitochondria, and cardiac transforming growth factor-β1 (TGF-β1) of the AT1-KO mice were compared with the same model with nephrectomy only and untreated with SXND. AT1-KO mice did not affect the process of CRI but it could significantly affect cardiac remodeling process. SXND decreased to some extent the AT1-KO mice's BUN, SCr, BNP, and cardiac LVDD, LVDS, and BNP, improved FS and EF, lowered the expression of collagen type I and III in heart and kidney, increased the quantity of mitochondria and ameliorated their structure, and down-regulated the expression of TGF-β1. SXND may antagonize the renin-angiotensin system (RAS) and decrease uremia toxins, thereby ameliorating ventricular remodeling in CRI. Furthermore, SXND has a mechanism correlated with the improvement of myocardial energy metabolism and the down-regulation of TGF-β1.

Caffeine does not affect susceptibility to cortical spreading depolarization in mice.

PubMed

Yalcin, Nilufer; Chen, Shih-Pin; Yu, Esther S; Liu, Tzu-Ting; Yen, Jiin-Cherng; Atalay, Yahya B; Qin, Tao; Celik, Furkan; van den Maagdenberg, Arn Mjm; Moskowitz, Michael A; Ayata, Cenk; Eikermann-Haerter, Katharina

2018-01-01

Several factors that modulate migraine, a common primary headache disorder, also affect susceptibility to cortical spreading depolarization (CSD). CSD is a wave of neuronal and glial depolarization and thought to underlie the migraine aura and possibly headache. Here, we tested whether caffeine, known to alleviate or trigger headache after acute exposure or chronic use/withdrawal, respectively, modulates CSD. We injected C57BL/6J mice with caffeine (30, 60, or 120 mg/kg; i.p.) once (acute) or twice per day for one or two weeks (chronic). Susceptibility to CSD was evaluated by measuring the electrical CSD threshold and by assessing KCl-induced CSD. Simultaneous laser Doppler flowmetry was used to assess CSD-induced cortical blood flow changes. Recordings were performed 15 min after caffeine/vehicle administration, or 24 h after the last dose of chronic caffeine in the withdrawal group. The latter paradigm was also tested in mice carrying the familial hemiplegic migraine type 1 R192Q missense mutation, considered a valid migraine model. Neither acute/chronic administration nor withdrawal of caffeine affected CSD susceptibility or related cortical blood flow changes, either in WT or R192Q mice. Hence, adverse or beneficial effects of caffeine on headache seem unrelated to CSD pathophysiology, consistent with the non-migrainous clinical presentation of caffeine-related headache.

Decreased number and increased volume with mitochondrial enlargement of cerebellar synaptic terminals in a mouse model of chronic demyelination.

PubMed

Nguyen, Huy Bang; Sui, Yang; Thai, Truc Quynh; Ikenaka, Kazuhiro; Oda, Toshiyuki; Ohno, Nobuhiko

2018-05-23

Impaired nerve conduction, axonal degeneration, and synaptic alterations contribute to neurological disabilities in inflammatory demyelinating diseases. Cerebellar dysfunction is associated with demyelinating disorders, but the alterations of axon terminals in cerebellar gray matter during chronic demyelination are still unclear. We analyzed the morphological and ultrastructural changes of climbing fiber terminals in a mouse model of hereditary chronic demyelination. Three-dimensional ultrastructural analyses using serial block-face scanning electron microscopy and immunostaining for synaptic markers were performed in a demyelination mouse model caused by extra copies of myelin gene (PLP4e). At 1 month old, many myelinated axons were observed in PLP4e and wild-type mice, but demyelinated axons and axons with abnormally thin myelin were prominent in PLP4e mice at 5 months old. The density of climbing fiber terminals was significantly reduced in PLP4e mice at 5 months old. Reconstruction of climbing fiber terminals revealed that PLP4e climbing fibers had increased varicosity volume and enlarged mitochondria in the varicosities at 5-month-old mice. These results suggest that chronic demyelination is associated with alterations and loss of climbing fiber terminals in the cerebellar cortex, and that synaptic changes may contribute to cerebellar phenotypes observed in hereditary demyelinating disorders.

[Modelling of viral-chemical carcinogenesis in chronic infection in mice caused by the herpes simplex type 2 virus].

PubMed

Kitsak, V Ia; Moĭsiadi, S A; Bocharov, A F

1979-01-01

The influence of chronic herpetic infection of white mice caused by herpes simplex virus type 2 (HSV-2) on the blastomogenic effect of a polycyclic hydro-carbon, 20-methylcholanthrene (20-MCA), was studied. Solid tumors developed in 20-MCA-treated mice on the side of the carcinogen administration within 81--89 days. The simultaneous administration of 70 intracerebral LD50 of HSV-2 subcutaneously into a hind leg pad and 0.1 mg 20-MCA subcutaneously into the inguinal area was accompanied by a synergistic action of the two factors. The number of tumors in the animals treated with HSV-2 in combination with 20-MCA at all intervals of observation was 1.5--2.5 times greater than in mice treated with 20-MCA alone. Mice weighing 10--12 g were more sensitive to the synergistic effect of HSV-2 and 20-MCA, whereas animals weighing 25--30 g were more sensitive to the carcinogenic effect of 20-MCA alone. No tumors developed in mice infected with HSV-2 alone by 167 days (the observation period). Mice weighing 10--12 g were found to be more sensitive to the fatal effect of HSV-2 and HSV-2 plus 20-MCA, particularly in the first 2--3 weeks after inoculation. Six months after inoculation with HSV-2 the virus was isolated from posterior root ganglia of the sacral and lumbar spinal cord by cocultivation of the ganglia with human embryo skin-muscle tissue cells.

Involvement of Smad3 phosphoisoform-mediated signaling in the development of colonic cancer in IL-10-deficient mice.

PubMed

Hachimine, Daisaku; Uchida, Kazushige; Asada, Masanori; Nishio, Akiyoshi; Kawamata, Seiji; Sekimoto, Go; Murata, Miki; Yamagata, Hideo; Yoshida, Katsunori; Mori, Shigeo; Tahashi, Yoshiya; Matsuzaki, Koichi; Okazaki, Kazuichi

2008-06-01

Chronic inflammation predisposes to cancer. Transforming growth factor (TGF)-beta, a multifunctional protein, suppresses the growth of normal colonic epithelial cells, whereas it stimulates the proliferation of cancer cells. Interleukin (IL)-10-deficient mice, which develop colitis and colorectal cancer, show an increased level of plasma TGF-beta. Although TGF-beta may be a key molecule in the development of colon cancer arising from chronic colitis in IL-10-deficient mice, the role of TGF-beta still remains unclear. TGF-beta activates not only TGF-beta type I receptor (TbetaRI) but also c-Jun N-terminal kinase (JNK), which converts the mediator Smad3 into two distinctive phosphoisoforms: C-terminally phosphorylated Smad3 (pSmad3C) and linker-phosphorylated Smad3 (pSmad3L). We studied C57BL/6-IL-10-deficient mice (n=18) at 4 to 32 weeks of age. We investigated histology, and pSmad2/3L, pSmad2/3C, and p53 by immunohistochemistry. pSmad3L staining was detected in the cancer cells in all 10 mice with colonic cancer and in the epithelial cells in 7 of 12 mice with colonic dysplasia, but not in the normal or colitic mice. pSmad3c was detected without any significant difference between stages. p53 was weakly stained in a few cancer cells in 5 out of 10 mice. Smad3L signaling plays an important role in the carcinogenesis of chronic colitis in IL-10-deficient mice.

Non-alcoholic fatty liver disease induces signs of Alzheimer's disease (AD) in wild-type mice and accelerates pathological signs of AD in an AD model.

PubMed

Kim, Do-Geun; Krenz, Antje; Toussaint, Leon E; Maurer, Kirk J; Robinson, Sudie-Ann; Yan, Angela; Torres, Luisa; Bynoe, Margaret S

2016-01-05

Non-alcoholic fatty liver disease (NAFLD) is a chronic liver disease afflicting about one third of the world's population and 30 % of the US population. It is induced by consumption of high-lipid diets and is characterized by liver inflammation and subsequent liver pathology. Obesity and consumption of a high-fat diet are known to increase the risk of Alzheimer's disease (AD). Here, we investigated NAFLD-induced liver inflammation in the pathogenesis of AD. WT and APP-Tg mice were fed with a standard diet (SD) or a high-fat diet (HFD) for 2, 5 months, or 1 year to induce NAFLD. Another set of APP-Tg mice were removed from HFD after 2 months and put back on SD for 3 months. During acute phase NAFLD, WT and APP-Tg mice developed significant liver inflammation and pathology that coincided with increased numbers of activated microglial cells in the brain, increased inflammatory cytokine profile, and increased expression of toll-like receptors. Chronic NAFLD induced advanced pathological signs of AD in both WT and APP-Tg mice, and also induced neuronal apoptosis. We observed decreased brain expression of low-density lipoprotein receptor-related protein-1 (LRP-1) which is involved in β-amyloid clearance, in both WT and APP-Tg mice after ongoing administration of the HFD. LRP-1 expression correlated with advanced signs of AD over the course of chronic NAFLD. Removal of mice from HFD during acute NAFLD reversed liver pathology, decreased signs of activated microglial cells and neuro-inflammation, and decreased β-amyloid plaque load. Our findings indicate that chronic inflammation induced outside the brain is sufficient to induce neurodegeneration in the absence of genetic predisposition.

Targeted activation of endothelin-1 exacerbates hypoxia-induced pulmonary hypertension

DOE Office of Scientific and Technical Information (OSTI.GOV)

Satwiko, Muhammad Gahan; Ikeda, Koji; Nakayama, Kazuhiko

Pulmonary arterial hypertension (PAH) is a fatal disease that eventually results in right heart failure and death. Current pharmacologic therapies for PAH are limited, and there are no drugs that could completely cure PAH. Enhanced activity of endothelin system has been implicated in PAH severity and endothelin receptor antagonists have been used clinically to treat PAH. However, there is limited experimental evidence on the direct role of enhanced endothelin system activity in PAH. Here, we investigated the correlation between endothelin-1 (ET-1) and PAH using ET-1 transgenic (ETTG) mice. Exposure to chronic hypoxia increased right ventricular pressure and pulmonary arterial wallmore » thickness in ETTG mice compared to those in wild type mice. Of note, ETTG mice exhibited modest but significant increase in right ventricular pressure and vessel wall thickness relative to wild type mice even under normoxic conditions. To induce severe PAH, we administered SU5416, a vascular endothelial growth factor receptor inhibitor, combined with exposure to chronic hypoxia. Treatment with SU5416 modestly aggravated hypoxia-induced pulmonary hypertension, right ventricular hypertrophy, and pulmonary arterial vessel wall thickening in ETTG mice in association with increased interleukin-6 expression in blood vessels. However, there was no sign of obliterative endothelial cell proliferation and plexiform lesion formation in the lungs. These results demonstrated that enhanced endothelin system activity could be a causative factor in the development of PAH and provided rationale for the inhibition of endothelin system to treat PAH. - Highlights: • Role of endothelin-1 in pulmonary arterial hypertension (PAH) was investigated. • The endothelin-1 transgenic (ETTG) and wild type (WT) mice were analyzed. • ETTG mice spontaneously developed PAH under normoxia conditions. • SU5416 further aggravated PAH in ETTG mice. • Enhanced endothelin system activity could be a causative factor in PAH development.« less

Lithium ameliorates altered glycogen synthase kinase-3 and behavior in a mouse model of fragile X syndrome.

PubMed

Yuskaitis, Christopher J; Mines, Marjelo A; King, Margaret K; Sweatt, J David; Miller, Courtney A; Jope, Richard S

2010-02-15

Fragile X syndrome (FXS), the most common form of inherited mental retardation and a genetic cause of autism, results from mutated fragile X mental retardation-1 (Fmr1). This study examined the effects on glycogen synthase kinase-3 (GSK3) of treatment with a metabotropic glutamate receptor (mGluR) antagonist, MPEP, and the GSK3 inhibitor, lithium, in C57Bl/6 Fmr1 knockout mice. Increased mGluR signaling may contribute to the pathology of FXS, and the mGluR5 antagonist MPEP increased inhibitory serine-phosphorylation of brain GSK3 selectively in Fmr1 knockout mice but not in wild-type mice. Inhibitory serine-phosphorylation of GSK3 was lower in Fmr1 knockout, than wild-type, mouse brain regions and was increased by acute or chronic lithium treatment, which also increased hippocampal brain-derived neurotrophic factor levels. Fmr1 knockout mice displayed alterations in open-field activity, elevated plus-maze, and passive avoidance, and these differences were ameliorated by chronic lithium treatment. These findings support the hypothesis that impaired inhibition of GSK3 contributes to the pathogenesis of FXS and support GSK3 as a potential therapeutic target.

Orexin signaling mediates the antidepressant-like effect of calorie restriction.

PubMed

Lutter, Michael; Krishnan, Vaishnav; Russo, Scott J; Jung, Saendy; McClung, Colleen A; Nestler, Eric J

2008-03-19

During periods of reduced food availability, animals must respond with behavioral adaptations that promote survival. Despite the fact that many psychiatric syndromes include disordered eating patterns as a component of the illness, little is known about the neurobiology underlying behavioral changes induced by short-term calorie restriction. Presently, we demonstrate that 10 d of calorie restriction, corresponding to a 20-25% weight loss, causes a marked antidepressant-like response in two rodent models of depression and that this response is dependent on the hypothalamic neuropeptide orexin (hypocretin). Wild-type mice, but not mice lacking orexin, show longer latency to immobility and less total immobility in the forced swim test after calorie restriction. In the social defeat model of chronic stress, calorie restriction reverses the behavioral deficits seen in wild-type mice but not in orexin knock-out mice. Additionally, chronic social defeat stress induces a prolonged reduction in the expression of prepro-orexin mRNA via epigenetic modification of the orexin gene promoter, whereas calorie restriction enhances the activation of orexin cells after social defeat. Together, these data indicate that orexin plays an essential role in mediating reduced depression-like symptoms induced by calorie restriction.

Essential Role of Protein-tyrosine Phosphatase 1B in the Modulation of Insulin Signaling by Acetaminophen in Hepatocytes*

PubMed Central

Mobasher, Maysa Ahmed; de Toro-Martín, Juan; González-Rodríguez, Águeda; Ramos, Sonia; Letzig, Lynda G.; James, Laura P.; Muntané, Jordi; Álvarez, Carmen; Valverde, Ángela M.

2014-01-01

Many drugs are associated with the development of glucose intolerance or deterioration in glycemic control in patients with pre-existing diabetes. We have evaluated the cross-talk between signaling pathways activated by acetaminophen (APAP) and insulin signaling in hepatocytes with or without expression of the protein-tyrosine phosphatase 1B (PTP1B) and in wild-type and PTP1B-deficient mice chronically treated with APAP. Human primary hepatocytes, Huh7 hepatoma cells with silenced PTP1B, mouse hepatocytes from wild-type and PTP1B-deficient mice, and a mouse model of chronic APAP treatment were used to examine the mechanisms involving PTP1B in the effects of APAP on glucose homeostasis and hepatic insulin signaling. In APAP-treated human hepatocytes at concentrations that did not induce death, phosphorylation of JNK and PTP1B expression and enzymatic activity were increased. APAP pretreatment inhibited activation of the early steps of insulin signaling and decreased Akt phosphorylation. The effects of APAP in insulin signaling were prevented by suramin, a PTP1B inhibitor, or rosiglitazone that decreased PTP1B levels. Likewise, PTP1B deficiency in human or mouse hepatocytes protected against APAP-mediated impairment in insulin signaling. These signaling pathways were modulated in mice with chronic APAP treatment, resulting in protection against APAP-mediated hepatic insulin resistance and alterations in islet alpha/beta cell ratio in PTP1B−/− mice. Our results demonstrate negative cross-talk between signaling pathways triggered by APAP and insulin signaling in hepatocytes, which is in part mediated by PTP1B. Moreover, our in vivo data suggest that chronic use of APAP may be associated with insulin resistance in the liver. PMID:25204659

Role of paraoxonase (PON1) status in pesticide sensitivity: genetic and temporal determinants.

PubMed

Furlong, Clement E; Cole, Toby B; Jarvik, Gail P; Pettan-Brewer, Christina; Geiss, Gary K; Richter, Rebecca J; Shih, Diana M; Tward, Aaron D; Lusis, Aldons J; Costa, Lucio G

2005-08-01

Individual differences in detoxication capacities for specific organophosphorous (OP) compounds are due largely to differences in catalytic efficiency or abundance of the HDL-associated enzyme, paraoxonase (PON1). First, we provide evidence that children less than 2 years of age represent a particularly susceptible population for OP exposure due to low abundance of PON1 and variable onset of plasma PON1 activity. Second, we describe studies examining the neurotoxic effects of chronic, low-level OP pesticide exposure in mice. PON1 knockout (PON1(-/-)) and wild-type mice were exposed chronically (PN4 to PN21) to low levels of chlorpyrifos oxon (CPO). Endpoints included cholinesterase activity, histopathology, gene expression, and behavior. Even at PN4, when PON1 levels were low in wild-type mice, PON1(-/-) mice were more sensitive to inhibition of brain cholinesterase by CPO. At PN22, and persisting as long as 4 months, chronic developmental exposure to 0.18 mg/kg/d or 0.25 mg/kg/d CPO resulted in perinuclear vacuolization of cells in a discrete area of the neocortex and irregular distribution of neurons in the cortical plate, with an increase in the number of affected cells at 0.25mg/kg/d. Third, we describe a transgenic mouse model in which human transgenes encoding either hPON1Q192 or hPON1R192 were expressed at equal levels in place of mouse PON1. The developmental onset of expression followed the mouse time course and was identical for the two transgenes, allowing these mice to be used to assess the importance of the Q192R polymorphism during development. Adult mice expressing hPON1R192 were significantly more resistant than hPON1Q192 mice to CPO toxicity. Our studies indicate that children less than 2 years old, especially those homozygous for PON1Q192, would be predicted to be particularly susceptible to CPO toxicity.

Morphine Tolerance and Physical Dependence Are Altered in Conditional HIV-1 Tat Transgenic Mice.

PubMed

Fitting, Sylvia; Stevens, David L; Khan, Fayez A; Scoggins, Krista L; Enga, Rachel M; Beardsley, Patrick M; Knapp, Pamela E; Dewey, William L; Hauser, Kurt F

2016-01-01

Despite considerable evidence that chronic opiate use selectively affects the pathophysiologic consequences of human immunodeficiency virus type 1 (HIV-1) infection in the nervous system, few studies have examined whether neuro-acquired immune deficiency syndrome (neuroAIDS) might intrinsically alter the pharmacologic responses to chronic opiate exposure. This is an important matter because HIV-1 and opiate abuse are interrelated epidemics, and HIV-1 patients are often prescribed opiates as a treatment of HIV-1-related neuropathic pain. Tolerance and physical dependence are inevitable consequences of frequent and repeated administration of morphine. In the present study, mice expressing HIV-1 Tat in a doxycycline (DOX)-inducible manner [Tat(+)], their Tat(-) controls, and control C57BL/6 mice were chronically exposed to placebo or 75-mg morphine pellets to explore the effects of Tat induction on morphine tolerance and dependence. Antinociceptive tolerance and locomotor activity tolerance were assessed using tail-flick and locomotor activity assays, respectively, and physical dependence was measured with the platform-jumping assay and recording of other withdrawal signs. We found that Tat(+) mice treated with DOX [Tat(+)/DOX] developed an increased tolerance in the tail-flick assay compared with control Tat(-)/DOX and/or C57/DOX mice. Equivalent tolerance was developed in all mice when assessed by locomotor activity. Further, Tat(+)/DOX mice expressed reduced levels of physical dependence to chronic morphine exposure after a 1-mg/kg naloxone challenge compared with control Tat(-)/DOX and/or C57/DOX mice. Assuming the results seen in Tat transgenic mice can be generalized to neuroAIDS, our findings suggest that HIV-1-infected individuals may display heightened analgesic tolerance to similar doses of opiates compared with uninfected individuals and show fewer symptoms of physical dependence. Copyright © 2015 by The American Society for Pharmacology and Experimental Therapeutics.

RLIP76 Protein Knockdown Attenuates Obesity Due to a High-fat Diet*

PubMed Central

Singhal, Sharad S.; Figarola, James; Singhal, Jyotsana; Reddy, Marpadga A.; Liu, Xueli; Berz, David; Natarajan, Rama; Awasthi, Sanjay

2013-01-01

Feeding a Western high-fat diet (HFD) to C57BL/6 mice induces obesity, associated with a chronic inflammatory state, lipid transport, and metabolic derangements, and organ system effects that particularly prominent in the kidneys. Here, we report that RLIP76 homozygous knock-out (RLIP76−/−) mice are highly resistant to obesity as well as these other features of metabolic syndrome caused by HFD. The normal increase in pro-inflammatory and fibrotic markers associated with HFD induced obesity in wild-type C57B mice was broadly and nearly completely abrogated in RLIP76−/− mice. This is a particularly striking finding because chemical markers of oxidative stress including lipid hydroperoxides and alkenals were significantly higher in RLIP76−/− mice. Whereas HFD caused marked suppression of AMPK in wild-type C57B mice, RLIP76−/− mice had baseline activation of AMP-activated protein kinase, which was not further affected by HFD. The baseline renal function was reduced in RLIP76−/− mice as compared with wild-type, but was unaffected by HFD, in marked contrast to severe renal impairment and glomerulopathy in the wild-type mice given HFD. Our findings confirm a fundamental role of RLIP76 in regulating the function of obesity-promoting pro-inflammatory cytokines, and provide a novel mechanism for targeted therapy of obesity and metabolic syndrome. PMID:23821548

Experimental transmission of systemic AA amyloidosis in autoimmune disease and type 2 diabetes mellitus model mice.

PubMed

Maeda, Mayuko; Murakami, Tomoaki; Muhammad, Naeem; Inoshima, Yasuo; Ishiguro, Naotaka

2016-11-01

AA amyloidosis is a protein misfolding disease characterized by extracellular deposition of amyloid A (AA) fibrils. AA amyloidosis has been identified in food animals, and it has been postulated that AA amyloidosis may be transmissible to different animal species. Since the precursor protein of AA fibrils is serum amyloid A (SAA), which is an inflammatory acute phase protein, AA amyloidosis is considered to be associated with inflammatory diseases such as rheumatoid arthritis. Chronic diseases such as autoimmune disease and type 2 diabetes mellitus could be potential factors for AA amyloidosis. In this study, to examine the relationship between the induction of AA amyloidosis and chromic abnormalities such as autoimmune disease or type 2 diabetes mellitus, amyloid fibrils from mice, cattle, or chickens were experimentally injected into disease model mice. Wild-type mice were used as controls. The concentrations of SAA, IL-6, and IL-10 in autoimmune disease model mice were higher than those of control mice. However, induction of AA amyloidosis in autoimmune disease and type 2 diabetes mellitus model mice was lower than that in control mice, and the amount of amyloid deposits in the spleens of both mouse models was lower than that of control mice according to Congo red staining and immunohistochemistry. These results suggest that factors other than SAA levels, such as an inflammatory or anti-inflammatory environment in the immune response, may be involved in amyloid deposition.

Thioredoxin reverses age-related hypertension by chronically improving vascular redox and restoring eNOS function

PubMed Central

Hilgers, Rob H. P.; Kundumani-Sridharan, Venkatesh; Subramani, Jaganathan; Chen, Leon C.; Cuello, Luis G.; Rusch, Nancy J.; Das, Kumuda C.

2017-01-01

The incidence of high blood pressure with advancing age is notably high, and it is an independent prognostic factor for the onset or progression of a variety of cardiovascular disorders. Although age-related hypertension is an established phenomenon, current treatments are only palliative but not curative. Thus, there is a critical need for a curative therapy against age-related hypertension, which could greatly decrease the incidence of cardiovascular disorders. We show that overexpression of human thioredoxin (TRX), a redox protein, in mice prevents age-related hypertension. Further, injection of recombinant human TRX (rhTRX) for three consecutive days reversed hypertension in aged wild-type mice, and this effect lasted for at least 20 days. Arteries of wild-type mice injected with rhTRX or mice with TRX overexpression exhibited decreased arterial stiffness, greater endothelium-dependent relaxation, increased nitric oxide production, and decreased superoxide anion (O2•−) generation compared to either saline-injected aged wild-type mice or mice with TRX deficiency. Our study demonstrates a potential translational role of rhTRX in reversing age-related hypertension with long-lasting efficacy. PMID:28179506

Intestinal epithelial cells as producers but not targets of chronic TNF suffice to cause murine Crohn-like pathology

PubMed Central

Roulis, Manolis; Armaka, Maria; Manoloukos, Menelaos; Apostolaki, Maria; Kollias, George

2011-01-01

TNF plays a crucial role in the pathogenesis of Crohn disease. Dysregulated TNF production in mice that bear the genetic deletion of the TNF AU-rich regulatory elements (ARE) (TnfΔARE/+ mice) results in TNF receptor I (TNFRI)-dependent spontaneous Crohn-like pathology. Current concepts consider intestinal epithelial cell (IEC) responses to TNF to be critical for intestinal pathology, but the potential contribution of IEC-derived TNF in disease pathogenesis has not been addressed. In this study we examined whether IEC are sufficient as cellular targets or sources of TNF in the development of intestinal pathology. Using IEC-specific reactivation of a hypomorphic TnfΔAREneo allele in mice, we show that selective chronic overproduction of TNF by IEC suffices to cause full development of Crohn-like pathology. Epithelial TNF overexpression leads to early activation of the underlying intestinal myofibroblast, a cell type previously identified as a sufficient target of TNF for disease development in the TnfΔARE model. By contrast, restricted TNFRI expression on IEC although sufficient to confer IEC apoptosis after acute exogenous TNF administration, fails to induce pathology following chronic specific targeting of IEC by endogenous TNF in TnfΔARE/+ mice. Our results argue against IEC being early and sufficient responders to chronic TNF-mediated pathogenic signals and suggest that proinflammatory aberrations leading to chronic TNF production by IEC may initiate pathology in Crohn disease. PMID:21402942

Chronic Trypanosoma cruzi infection potentiates adipose tissue macrophage polarization toward an anti-inflammatory M2 phenotype and contributes to diabetes progression in a diet-induced obesity model.

PubMed

Cabalén, María E; Cabral, María F; Sanmarco, Liliana M; Andrada, Marta C; Onofrio, Luisina I; Ponce, Nicolás E; Aoki, María P; Gea, Susana; Cano, Roxana C

2016-03-22

Chronic obesity and Chagas disease (caused by the protozoan Trypanosoma cruzi) represent serious public health concerns. The interrelation between parasite infection, adipose tissue, immune system and metabolism in an obesogenic context, has not been entirely explored. A novel diet-induced obesity model (DIO) was developed in C57BL/6 wild type mice to examine the effect of chronic infection (DIO+I) on metabolic parameters and on obesity-related disorders. Dyslipidemia, hyperleptinemia, and cardiac/hepatic steatosis were strongly developed in DIO mice. Strikingly, although these metabolic alterations were collectively improved by infection, plasmatic apoB100 levels remain significantly increased in DIO+I, suggesting the presence of pro-atherogenic small and dense LDL particles. Moreover, acute insulin resistance followed by chronic hyperglycemia with hypoinsulinemia was found, evidencing an infection-related-diabetes progression. These lipid and glucose metabolic changes seemed to be highly dependent on TLR4 expression since TLR4-/- mice were protected from obesity and its complications. Notably, chronic infection promoted a strong increase in MCP-1 producing macrophages with a M2 (F4/80+CD11c-CD206+) phenotype associated to oxidative stress in visceral adipose tissue of DIO+I mice. Importantly, infection reduced lipid content but intensified inflammatory infiltrates in target tissues. Thus, parasite persistence in an obesogenic environment and the resulting host immunometabolic dysregulation may contribute to diabetes/atherosclerosis progression.

Chronic ethanol consumption lessens the gain of body weight, liver triglycerides, and diabetes in obese ob/ob mice.

PubMed

Fromenty, Bernard; Vadrot, Nathalie; Massart, Julie; Turlin, Bruno; Barri-Ova, Nadège; Lettéron, Philippe; Fautrel, Alain; Robin, Marie-Anne

2009-10-01

Clinical studies suggest that moderate alcohol consumption can have beneficial effects, in particular regarding cardiovascular events, insulin resistance, and type 2 diabetes. In this study, lean and obese diabetic ob/ob mice were submitted or not to chronic ethanol intake via the drinking water for 6 months, which was associated with moderate levels of plasma ethanol. Plasma levels of alanine aminotransferase and aspartate aminotransferase were not increased by alcohol intake. Ethanol consumption progressively reduced the gain of body weight in ob/ob mice, but not in lean mice, and this was observed despite higher calorie intake. Increased plasma free fatty acids and glycerol in ethanol-treated ob/ob mice suggested peripheral lipolysis. Glycemia and insulinemia were significantly reduced, whereas adiponectinemia was increased in ethanol-treated ob/ob mice. Liver weight and triglycerides were significantly decreased in ethanol-treated ob/ob mice, and this was associated with less microvesicular steatosis. Hepatic levels of AMP-activated protein kinase and the phosphorylated form of acetyl-CoA carboxylase were higher in ethanol-treated ob/ob mice, suggesting better fatty acid oxidation. However, hepatic mRNA expression of several lipogenic genes was not reduced by ethanol consumption. Finally, mild oxidative stress was noticed in the liver of ethanol-treated mice, regardless of their genotype. Hence, our data are in keeping with clinical studies suggesting that moderate ethanol intake can have beneficial effects on type 2 diabetes and insulin sensitivity, at least in part through increased levels of plasma adiponectin. However, further studies are needed to determine whether long-term drinking of light-to-moderate amounts of ethanol is safe for the liver.

TRPM2 Channel Aggravates CNS Inflammation and Cognitive Impairment via Activation of Microglia in Chronic Cerebral Hypoperfusion.

PubMed

Miyanohara, Jun; Kakae, Masashi; Nagayasu, Kazuki; Nakagawa, Takayuki; Mori, Yasuo; Arai, Ken; Shirakawa, Hisashi; Kaneko, Shuji

2018-04-04

Chronic cerebral hypoperfusion is a characteristic seen in widespread CNS diseases, including neurodegenerative and mental disorders, and is commonly accompanied by cognitive impairment. Recently, several studies demonstrated that chronic cerebral hypoperfusion can induce the excessive inflammatory responses that precede neuronal dysfunction; however, the precise mechanism of cognitive impairment due to chronic cerebral hypoperfusion remains unknown. Transient receptor potential melastatin 2 (TRPM2) is a Ca 2+ -permeable channel that is abundantly expressed in immune cells and is involved in aggravation of inflammatory responses. Therefore, we investigated the pathophysiological role of TRPM2 in a mouse chronic cerebral hypoperfusion model with bilateral common carotid artery stenosis (BCAS). When male mice were subjected to BCAS, cognitive dysfunction and white matter injury at day 28 were significantly improved in TRPM2 knock-out (TRPM2-KO) mice compared with wild-type (WT) mice, whereas hippocampal damage was not observed. There were no differences in blood-brain barrier breakdown and H 2 O 2 production between the two genotypes at 14 and 28 d after BCAS. Cytokine production was significantly suppressed in BCAS-operated TRPM2-KO mice compared with WT mice at day 28. In addition, the number of Iba1-positive cells gradually decreased from day 14. Moreover, daily treatment with minocycline significantly improved cognitive perturbation. Surgical techniques using bone marrow chimeric mice revealed that activated Iba1-positive cells in white matter could be brain-resident microglia, not peripheral macrophages. Together, these findings suggest that microglia contribute to the aggravation of cognitive impairment by chronic cerebral hypoperfusion, and that TRPM2 may be a potential target for chronic cerebral hypoperfusion-related disorders. SIGNIFICANCE STATEMENT Chronic cerebral hypoperfusion is manifested in a wide variety of CNS diseases, including neurodegenerative and mental disorders that are accompanied by cognitive impairment; however, the underlying mechanisms require clarification. Here, we used a chronic cerebral hypoperfusion mouse model to investigate whether TRPM2, a Ca 2+ -permeable cation channel highly expressed in immune cells, plays a destructive role in the development of chronic cerebral hypoperfusion-induced cognitive impairment, and propose a new hypothesis in which TRPM2-mediated activation of microglia, not macrophages, specifically contributes to the pathology through the aggravation of inflammatory responses. These findings shed light on the understanding of the mechanisms of chronic cerebral hypoperfusion-related inflammation, and are expected to provide a novel therapeutic molecule for cognitive impairment in CNS diseases. Copyright © 2018 the authors 0270-6474/18/383521-14$15.00/0.

Thyroid epithelial cell hyperplasia in IFN-gamma deficient NOD.H-2h4 mice.

PubMed

Yu, Shiguang; Sharp, Gordon C; Braley-Mullen, Helen

2006-01-01

The role of inflammatory cells in thyroid epithelial cell (thyrocyte) hyperplasia is unknown. Here, we demonstrate that thyrocyte hyperplasia in IFN-gamma-/- NOD.H-2h4 mice has an autoimmune basis. After chronic exposure to increased dietary iodine, 60% of IFN-gamma-/- mice had severe thyrocyte hyperplasia with minimal or moderate lymphocyte infiltration, and thyroid dysfunction with reduced serum T4. All mice produced anti-thyroglobulin autoantibody. Some wild-type NOD.H-2h4 mice had isolated areas of thyrocyte hyperplasia with predominantly lymphocytic infiltration, whereas IL-4-/- and 50% of wild-type NOD.H-2h4 mice developed lymphocytic thyroiditis but no thyrocyte hyperplasia. Both thyroid infiltrating inflammatory cells and environmental factors (iodine) were required to induce thyrocyte hyperplasia. Splenocytes from IFN-gamma-/- mice with thyrocyte hyperplasia, but not splenocytes from naïve IFN-gamma-/- mice, induced hyperplasia in IFN-gamma-/- NOD.H-2h4.SCID mice. These results may provide clues for understanding the mechanisms underlying development of epithelial cell hyperplasia not only in thyroids but also in other tissues and organs.

Phenytoin promotes Th2 type immune response in mice

PubMed Central

Okada, K; Sugiura, T; Kuroda, E; Tsuji, S; Yamashita, U

2001-01-01

The effects of chronic administration of phenytoin, a common anticonvulsive drug, on immune responses were studied in mice. Anti-keyhole limpet haemocyanin (KLH) IgE antibody response after KLH-immunization was enhanced in phenytoin-treated mice. Proliferative responses of spleen cells induced with KLH, concanavalin A (ConA), lipopolysaccharide and anti-CD3 antibody were reduced in phenytoin-treated mice. Accessory function of spleen adherent cells on ConA-induced T cell proliferative response was reduced in phenytoin-treated mice. KLH-induced IL-4 production of spleen cells was enhanced, while IFN-γ production was reduced in phenytoin-treated mice. In addition, production of IL-1α, but not IL-6 and IL-12 by spleen adherent cells from phenytoin-treated mice was reduced. Natural killer cell activity was reduced in phenytoin-treated mice. These results suggest that phenytoin treatment preferentially induces a Th2 type response. We also observed that plasma ACTH and corticosterone levels were increased in phenytoin-treated mice, and speculated that phenytoin might act directly and indirectly, through HPA axis activation, on the immune system to modulate Th1/Th2 balance. PMID:11472401

Chronic Enhancement of CREB Activity in the Hippocampus Interferes with the Retrieval of Spatial Information

ERIC Educational Resources Information Center

Viosca, Jose; Malleret, Gael; Bourtchouladze, Rusiko; Benito, Eva; Vronskava, Svetlana; Kandel, Eric R.; Barco, Angel

2009-01-01

The activation of cAMP-responsive element-binding protein (CREB)-dependent gene expression is thought to be critical for the formation of different types of long-term memory. To explore the consequences of chronic enhancement of CREB function on spatial memory in mammals, we examined spatial navigation in bitransgenic mice that express in a…

An investigation into "two hit" effects of BDNF deficiency and young-adult cannabinoid receptor stimulation on prepulse inhibition regulation and memory in mice.

PubMed

Klug, Maren; van den Buuse, Maarten

2013-01-01

Reduced brain-derived neurotrophic factor (BDNF) signaling has been shown in the frontal cortex and hippocampus in schizophrenia. The aim of the present study was to investigate whether a BDNF deficit would modulate effects of chronic cannabis intake, a well-described risk factor for schizophrenia development. BDNF heterozygous mice (HET) and wild-type controls were chronically treated during weeks 6, 7, and 8 of life with the cannabinoid receptor agonist, CP55,940 (CP). After a 2-week delay, there were no CP-induced deficits in any of the groups in short-term spatial memory in a Y-maze task or novel object recognition memory. Baseline prepulse inhibition (PPI) was lower but average startle was increased in BDNF HET compared to wild-type controls. Acute CP administration before the PPI session caused a marked increase in PPI in male HET mice pre-treated with CP but not in any of the other male groups. In females, there were small increases of PPI in all groups upon acute CP administration. Acute CP administration furthermore reduced startle and this effect was greater in HET mice irrespective of chronic CP pre-treatment. Analysis of the levels of [(3)H]CP55,940 binding by autoradiography revealed a significant increase in the nucleus accumbens of male BDNF HET mice previously treated with CP but not in any of the other groups or in the caudate nucleus. These results show that BDNF deficiency and chronic young-adult cannabinoid receptor stimulation do not interact in this model on learning and memory later in life. In contrast, male "two hit" mice, but not females, were hypersensitive to the effect of acute CP on sensorimotor gating. These effects may be related to a selective increase of [(3)H]CP55,940 binding in the nucleus accumbens, reflecting up-regulation of CB1 receptor density in this region. These data could be of relevance to our understanding of differential "two hit" neurodevelopmental mechanisms in schizophrenia.

An investigation into “two hit” effects of BDNF deficiency and young-adult cannabinoid receptor stimulation on prepulse inhibition regulation and memory in mice

PubMed Central

Klug, Maren; van den Buuse, Maarten

2013-01-01

Reduced brain-derived neurotrophic factor (BDNF) signaling has been shown in the frontal cortex and hippocampus in schizophrenia. The aim of the present study was to investigate whether a BDNF deficit would modulate effects of chronic cannabis intake, a well-described risk factor for schizophrenia development. BDNF heterozygous mice (HET) and wild-type controls were chronically treated during weeks 6, 7, and 8 of life with the cannabinoid receptor agonist, CP55,940 (CP). After a 2-week delay, there were no CP-induced deficits in any of the groups in short-term spatial memory in a Y-maze task or novel object recognition memory. Baseline prepulse inhibition (PPI) was lower but average startle was increased in BDNF HET compared to wild-type controls. Acute CP administration before the PPI session caused a marked increase in PPI in male HET mice pre-treated with CP but not in any of the other male groups. In females, there were small increases of PPI in all groups upon acute CP administration. Acute CP administration furthermore reduced startle and this effect was greater in HET mice irrespective of chronic CP pre-treatment. Analysis of the levels of [3H]CP55,940 binding by autoradiography revealed a significant increase in the nucleus accumbens of male BDNF HET mice previously treated with CP but not in any of the other groups or in the caudate nucleus. These results show that BDNF deficiency and chronic young-adult cannabinoid receptor stimulation do not interact in this model on learning and memory later in life. In contrast, male “two hit” mice, but not females, were hypersensitive to the effect of acute CP on sensorimotor gating. These effects may be related to a selective increase of [3H]CP55,940 binding in the nucleus accumbens, reflecting up-regulation of CB1 receptor density in this region. These data could be of relevance to our understanding of differential “two hit” neurodevelopmental mechanisms in schizophrenia. PMID:24155701

Chronic subordination stress selectively downregulates the insulin signaling pathway in liver and skeletal muscle but not in adipose tissue of male mice

PubMed Central

Sanghez, Valentina; Cubuk, Cankut; Sebastián-Leon, Patricia; Carobbio, Stefania; Dopazo, Joaquin; Vidal-Puig, Antonio; Bartolomucci, Alessandro

2016-01-01

Abstract Chronic stress has been associated with obesity, glucose intolerance, and insulin resistance. We developed a model of chronic psychosocial stress (CPS) in which subordinate mice are vulnerable to obesity and the metabolic-like syndrome while dominant mice exhibit a healthy metabolic phenotype. Here we tested the hypothesis that the metabolic difference between subordinate and dominant mice is associated with changes in functional pathways relevant for insulin sensitivity, glucose and lipid homeostasis. Male mice were exposed to CPS for four weeks and fed either a standard diet or a high-fat diet (HFD). We first measured, by real-time PCR candidate genes, in the liver, skeletal muscle, and the perigonadal white adipose tissue (pWAT). Subsequently, we used a probabilistic analysis approach to analyze different ways in which signals can be transmitted across the pathways in each tissue. Results showed that subordinate mice displayed a drastic downregulation of the insulin pathway in liver and muscle, indicative of insulin resistance, already on standard diet. Conversely, pWAT showed molecular changes suggestive of facilitated fat deposition in an otherwise insulin-sensitive tissue. The molecular changes in subordinate mice fed a standard diet were greater compared to HFD-fed controls. Finally, dominant mice maintained a substantially normal metabolic and molecular phenotype even when fed a HFD. Overall, our data demonstrate that subordination stress is a potent stimulus for the downregulation of the insulin signaling pathway in liver and muscle and a major risk factor for the development of obesity, insulin resistance, and type 2 diabetes mellitus. PMID:26946982

Disruption of Fatty Acid Amide Hydrolase Activity Prevents the Effects of Chronic Stress on Anxiety and Amygdalar Microstructure

PubMed Central

Hill, Matthew N.; Kumar, Shobha Anil; Filipski, Sarah B.; Iverson, Moriah; Stuhr, Kara L.; Keith, John M.; Cravatt, Benjamin F.; Hillard, Cecilia J.; Chattarji, Sumantra; McEwen, Bruce S.

2014-01-01

Hyperactivation of the amygdala following chronic stress is believed to be one of the primary mechanisms underlying the increased propensity for anxiety-like behaviors and pathological states; however, the mechanisms by which chronic stress modulates amygdalar function are not well characterized. The aim of the current study was to determine the extent to which the endocannabinoid system, which is known to regulate emotional behavior and neuroplasticity, contributes to changes in amygdalar structure and function following chronic stress. To examine the hypothesis, we have exposed C57/Bl6 mice to chronic restraint stress which results in an increase in fatty acid amide hydrolase (FAAH) activity and a reduction in the concentration of the endocannabinoid N-arachidonylethanolamine (AEA) within the amygdala. Chronic restraint stress also increased dendritic arborization, complexity and spine density of pyramidal neurons in the basolateral nucleus of the amygdala (BLA) and increased anxiety-like behavior in wild-type mice. All of the stress-induced changes in amygdalar structure and function were absent in mice deficient in FAAH. Further, the anti-anxiety effect of FAAH deletion was recapitulated in rats treated orally with a novel pharmacological inhibitor of FAAH, JNJ5003 (50 mg/kg/day), during exposure to chronic stress. These studies suggest that FAAH is required for chronic stress to induce hyperactivity and structural remodeling of the amygdala. Collectively, these studies indicate that FAAH-mediated decreases in AEA occur following chronic stress and that this loss of AEA signaling is functionally relevant to the effects of chronic stress. These data support the hypothesis that inhibition of FAAH has therapeutic potential in the treatment of anxiety disorders, possibly by maintaining normal amygdalar function in the face of chronic stress. PMID:22776900

Gender dependent contribution of muscarinic receptors in memory retrieval under sub-chronic stress.

PubMed

Rashid, Habiba; Ahmed, Touqeer

2018-05-15

Stress induces retrograde amnesia in humans and rodents. Muscarinic antagonism under normal physiological conditions causes gender dependent impairment in episodic memory retrieval. We aimed to explore the gender dependent role of muscarinic receptors in memory retrieval under sub-chronic stress condition. Male and female mice were trained for Morris water maze test and contextual fear conditioning, followed by 3 h restraint stress per day for five days. Stress was either given alone or in combination with a daily subcutaneous injection of scopolamine (1 mg/kg) or donepezil (1 mg/kg). Control mice were given saline without any stress. Sub-chronic stress (induced for five days) impaired spatial memory retrieval in males (P < 0.005) but not in females (P > 0.05). Stress induced spatial memory recall deficit in male mice was independent of muscarinic receptor activity (P > 0.05). However, stress induced contextual fear memory recall impairment was reversed by donepezil treatment in male (P < 0.005) and female (P < 0.0001) mice. These findings suggest that differential role of muscarinic activity in retrieving different types of memories under stress depends on gender of subjects. Copyright © 2018 Elsevier B.V. All rights reserved.

Involvement of the mitochondrial permeability transition pore in chronic ethanol-mediated liver injury in mice

PubMed Central

King, Adrienne L.; Swain, Telisha M.; Mao, Zhengkuan; Udoh, Uduak S.; Oliva, Claudia R.; Betancourt, Angela M.; Griguer, Corrine E.; Crowe, David R.; Lesort, Mathieu

2013-01-01

Chronic ethanol consumption increases sensitivity of the mitochondrial permeability transition (MPT) pore induction in liver. Ca2+ promotes MPT pore opening, and genetic ablation of cyclophilin D (CypD) increases the Ca2+ threshold for the MPT. We used wild-type (WT) and CypD-null (CypD−/−) mice fed a control or an ethanol-containing diet to investigate the role of the MPT in ethanol-mediated liver injury. Ca2+-mediated induction of the MPT and mitochondrial respiration were measured in isolated liver mitochondria. Steatosis was present in WT and CypD−/− mice fed ethanol and accompanied by increased terminal deoxynucleotidyl transferase dUTP-mediated nick-end label-positive nuclei. Autophagy was increased in ethanol-fed WT mice compared with ethanol-fed CypD−/− mice, as reflected by an increase in the ratio of microtubule protein 1 light chain 3B II to microtubule protein 1 light chain 3B I. Higher levels of p62 were measured in CypD−/− than WT mice. Ethanol decreased mitochondrial respiratory control ratios and select complex activities in WT and CypD−/− mice. Ethanol also increased CypD protein in liver of WT mice. Mitochondria from control- and ethanol-fed WT mice were more sensitive to Ca2+-mediated MPT pore induction than mitochondria from their CypD−/− counterparts. Mitochondria from ethanol-fed CypD−/− mice were also more sensitive to Ca2+-induced swelling than mitochondria from control-fed CypD−/− mice but were less sensitive than mitochondria from ethanol-fed WT mice. In summary, CypD deficiency was associated with impaired autophagy and did not prevent ethanol-mediated steatosis. Furthermore, increased MPT sensitivity was observed in mitochondria from ethanol-fed WT and CypD−/− mice. We conclude that chronic ethanol consumption likely lowers the threshold for CypD-regulated and -independent characteristics of the ethanol-mediated MPT pore in liver mitochondria. PMID:24356880

Airway remodelling and inflammation in asthma are dependent on the extracellular matrix protein fibulin-1c.

PubMed

Liu, Gang; Cooley, Marion A; Nair, Prema M; Donovan, Chantal; Hsu, Alan C; Jarnicki, Andrew G; Haw, Tatt Jhong; Hansbro, Nicole G; Ge, Qi; Brown, Alexandra C; Tay, Hock; Foster, Paul S; Wark, Peter A; Horvat, Jay C; Bourke, Jane E; Grainge, Chris L; Argraves, W Scott; Oliver, Brian G; Knight, Darryl A; Burgess, Janette K; Hansbro, Philip M

2017-12-01

Asthma is a chronic inflammatory disease of the airways. It is characterized by allergic airway inflammation, airway remodelling, and airway hyperresponsiveness (AHR). Asthma patients, in particular those with chronic or severe asthma, have airway remodelling that is associated with the accumulation of extracellular matrix (ECM) proteins, such as collagens. Fibulin-1 (Fbln1) is an important ECM protein that stabilizes collagen and other ECM proteins. The level of Fbln1c, one of the four Fbln1 variants, which predominates in both humans and mice, is increased in the serum and airways fluids in asthma but its function is unclear. We show that the level of Fbln1c was increased in the lungs of mice with house dust mite (HDM)-induced chronic allergic airway disease (AAD). Genetic deletion of Fbln1c and therapeutic inhibition of Fbln1c in mice with chronic AAD reduced airway collagen deposition, and protected against AHR. Fbln1c-deficient (Fbln1c -/- ) mice had reduced mucin (MUC) 5 AC levels, but not MUC5B levels, in the airways as compared with wild-type (WT) mice. Fbln1c interacted with fibronectin and periostin that was linked to collagen deposition around the small airways. Fbln1c -/- mice with AAD also had reduced numbers of α-smooth muscle actin-positive cells around the airways and reduced airway contractility as compared with WT mice. After HDM challenge, these mice also had fewer airway inflammatory cells, reduced interleukin (IL)-5, IL-13, IL-33, tumour necrosis factor (TNF) and CXCL1 levels in the lungs, and reduced IL-5, IL-33 and TNF levels in lung-draining lymph nodes. Therapeutic targeting of Fbln1c reduced the numbers of GATA3-positive Th2 cells in the lymph nodes and lungs after chronic HDM challenge. Treatment also reduced the secretion of IL-5 and IL-13 from co-cultured dendritic cells and T cells restimulated with HDM extract. Human epithelial cells cultured with Fbln1c peptide produced more CXCL1 mRNA than medium-treated controls. Our data show that Fbln1c may be a therapeutic target in chronic asthma. Copyright © 2017 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd. Copyright © 2017 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Effect of Shenxinning decoction on ventricular remodeling in AT1 receptor-knockout mice with chronic renal insufficiency

PubMed Central

Yang, Xuejun; Zhou, Hua; Qu, Huiyan; Liu, Weifang; Huang, Xiaojin; Shun, Yating; He, Liqun

2014-01-01

Objective: To observe the efficacy of Shenxinning Decoction (SXND) in ventricular remodeling in AT1 receptor-knockout (AT1-KO) mice with chronic renal insufficiency (CRI). Materials and Methods: AT1-KO mice modeled with subtotal (5/6) nephrectomy were intervened with SXND for 12 weeks. Subsequently, blood urea nitrogen (BUN), serum creatinine (SCr), brain natriuretic peptide (BNP), echocardiography (left ventricular end-diastolic diameter, LVDD; left ventricular end-systolic diameter, LVDS; fractional shortening, FS; and ejection fraction, EF), collagen types I and III in the heart and kidney, myocardial mitochondria, and cardiac transforming growth factor-β1 (TGF-β1) of the AT1-KO mice were compared with the same model with nephrectomy only and untreated with SXND. Results: AT1-KO mice did not affect the process of CRI but it could significantly affect cardiac remodeling process. SXND decreased to some extent the AT1-KO mice's BUN, SCr, BNP, and cardiac LVDD, LVDS, and BNP, improved FS and EF, lowered the expression of collagen type I and III in heart and kidney, increased the quantity of mitochondria and ameliorated their structure, and down-regulated the expression of TGF-β1. Conclusion: SXND may antagonize the renin–angiotensin system (RAS) and decrease uremia toxins, thereby ameliorating ventricular remodeling in CRI. Furthermore, SXND has a mechanism correlated with the improvement of myocardial energy metabolism and the down-regulation of TGF-β1. PMID:25097276

Dexamethasone-Mediated Changes in Adipose Triacylglycerol Metabolism Are Exaggerated, Not Diminished, in the Absence of a Functional GR Dimerization Domain

PubMed Central

Roohk, Donald J.; Mascharak, Smita; Khambatta, Cyrus; Leung, Ho; Hellerstein, Marc

2013-01-01

The glucocorticoid (GC) receptor (GR) has multiple effector mechanisms, including dimerization-mediated transactivation of target genes via DNA binding and transcriptional repression mediated by protein-protein interactions. Much attention has been focused on developing selective GR modulators that would dissociate adverse effects from therapeutic anti-inflammatory effects. The GRdim/dim mouse has a mutation in the dimerization domain of GR and has been shown to have attenuated transactivation with intact repression. To understand the role of GR dimerization-dependent targets in multiple tissues, we measured metabolic fluxes through several disease-relevant GC target pathways using heavy water labeling and mass spectrometry in wild-type and GRdim/dim mice administered the potent GC dexamethasone (DEX). Absolute triglyceride synthesis was increased in both wild-type and GRdim/dim mice by DEX in the inguinal and epididymal fat depots. GRdim/dim mice showed an exaggerated response to DEX in both depots. De novo lipogenesis was also greatly increased in both depots in response to DEX in GRdim/dim, but not wild-type mice. In contrast, the inhibitory effect of DEX on bone and skin collagen synthesis rates was greater in wild-type compared with GRdim/dim mice. Wild-type mice were more sensitive to DEX-dependent decreases in insulin sensitivity than GRdim/dim mice. Wild-type and GRdim/dim mice were equally sensitive to DEX-dependent decreases in muscle protein synthesis. Chronic elevation of GCs in GRdim/dim mice results in severe runting and lethality. In conclusion, some metabolic effects of GC treatment are exaggerated in adipose tissue of GRdim/dim mice, suggesting that selective GR modulators based on dissociating GR transactivation from repression should be evaluated carefully. PMID:23493372

Chronic cannabidiol treatment improves social and object recognition in double transgenic APPswe/PS1∆E9 mice.

PubMed

Cheng, David; Low, Jac Kee; Logge, Warren; Garner, Brett; Karl, Tim

2014-08-01

Patients suffering from Alzheimer's disease (AD) exhibit a decline in cognitive abilities including an inability to recognise familiar faces. Hallmark pathological changes in AD include the aggregation of amyloid-β (Aβ), tau protein hyperphosphorylation as well as pronounced neurodegeneration, neuroinflammation, neurotoxicity and oxidative damage. The non-psychoactive phytocannabinoid cannabidiol (CBD) exerts neuroprotective, anti-oxidant and anti-inflammatory effects and promotes neurogenesis. CBD also reverses Aβ-induced spatial memory deficits in rodents. Thus we determined the therapeutic-like effects of chronic CBD treatment (20 mg/kg, daily intraperitoneal injections for 3 weeks) on the APPswe/PS1∆E9 (APPxPS1) transgenic mouse model for AD in a number of cognitive tests, including the social preference test, the novel object recognition task and the fear conditioning paradigm. We also analysed the impact of CBD on anxiety behaviours in the elevated plus maze. Vehicle-treated APPxPS1 mice demonstrated impairments in social recognition and novel object recognition compared to wild type-like mice. Chronic CBD treatment reversed these cognitive deficits in APPxPS1 mice without affecting anxiety-related behaviours. This is the first study to investigate the effect of chronic CBD treatment on cognition in an AD transgenic mouse model. Our findings suggest that CBD may have therapeutic potential for specific cognitive impairments associated with AD.

Heterozygous disruption of activin receptor-like kinase 1 is associated with increased renal fibrosis in a mouse model of obstructive nephropathy.

PubMed

Muñoz-Félix, José M; López-Novoa, José M; Martínez-Salgado, Carlos

2014-02-01

Tubulointerstitial fibrosis is characterized by an accumulation of extracellular matrix in the renal interstitium, myofibroblast activation, cell infiltration, and tubular cell apoptosis, leading to chronic renal failure. Activin receptor-like kinase 1 (ALK1) is a transforming growth factor-β1 type I receptor with a pivotal role in endothelial proliferation and migration, but its role in the development of renal fibrosis is unknown. To assess this we used the unilateral ureteral obstruction model of tubulointerstitial fibrosis in ALK1 haploinsufficient (ALK1(+/-)) and wild-type mice. After 15 days, there was an increase in extracellular matrix protein expression in the obstructed kidneys from both ALK1(+/+) and ALK1(+/-) mice, but obstructed kidneys from ALK1(+/-) mice showed significantly higher expression of type I collagen than those from wild-type mice. Ureteral obstruction increased kidney myofibroblasts markers (α-smooth muscle actin and S100A4), without differences between mouse genotypes. ALK1 expression was increased after ureteral obstruction, and this increased expression was located in myofibroblasts. Moreover, cultured renal fibroblasts from ALK1(+/-) mice expressed more collagen type I and fibronectin than fibroblasts derived from wild-type mice. Thus, ALK1 modulates obstruction-induced renal fibrosis by increased extracellular matrix synthesis in myofibroblasts, but without differences in myofibroblast number.

Chronic Anatabine Treatment Reduces Alzheimer's Disease (AD)-Like Pathology and Improves Socio-Behavioral Deficits in a Transgenic Mouse Model of AD.

PubMed

Verma, Megha; Beaulieu-Abdelahad, David; Ait-Ghezala, Ghania; Li, Rena; Crawford, Fiona; Mullan, Michael; Paris, Daniel

2015-01-01

Anatabine is a minor tobacco alkaloid, which is also found in plants of the Solanaceae family and displays a chemical structure similarity with nicotine. We have shown previously that anatabine displays some anti-inflammatory properties and reduces microgliosis and tau phosphorylation in a pure mouse model of tauopathy. We therefore investigated the effects of a chronic oral treatment with anatabine in a transgenic mouse model (Tg PS1/APPswe) of Alzheimer's disease (AD) which displays pathological Aβ deposits, neuroinflammation and behavioral deficits. In the elevated plus maze, Tg PS1/APPswe mice exhibited hyperactivity and disinhibition compared to wild-type mice. Six and a half months of chronic oral anatabine treatment, suppressed hyperactivity and disinhibition in Tg PS1/APPswe mice compared to Tg PS1/APPswe receiving regular drinking water. Tg PS1/APPswe mice also elicited profound social interaction and social memory deficits, which were both alleviated by the anatabine treatment. We found that anatabine reduces the activation of STAT3 and NFκB in the vicinity of Aβ deposits in Tg PS1/APPswe mice resulting in a reduction of the expression of some of their target genes including Bace1, iNOS and Cox-2. In addition, a significant reduction in microgliosis and pathological deposition of Aβ was observed in the brain of Tg PS1/APPswe mice treated with anatabine. This is the first study to investigate the impact of chronic anatabine treatment on AD-like pathology and behavior in a transgenic mouse model of AD. Overall, our data show that anatabine reduces β-amyloidosis, neuroinflammation and alleviates some behavioral deficits in Tg PS1/APPswe, supporting further exploration of anatabine as a possible disease modifying agent for the treatment of AD.

Near-infrared lymphatic imaging demonstrates the dynamics of lymph flow and lymphangiogenesis during the acute versus chronic phases of arthritis in mice.

PubMed

Zhou, Quan; Wood, Ronald; Schwarz, Edward M; Wang, Yong-Jun; Xing, Lianping

2010-07-01

To develop an in vivo imaging method to assess lymphatic draining function in the K/BxN mouse model of inflammatory arthritis. Indocyanine green, a near-infrared fluorescent dye, was injected intradermally into the footpads of wild-type mice, mouse limbs were illuminated with an 806-nm near-infrared laser, and the movement of indocyanine green from the injection site to the draining popliteal lymph node (LN) was recorded with a CCD camera. Indocyanine green near-infrared images were analyzed to obtain 5 measures of lymphatic function across time. Images of K/BxN arthritic mice and control nonarthritic littermates were obtained at 1 month of age, when acute joint inflammation commenced, and again at 3 months of age, when joint inflammation became chronic. Lymphangiogenesis in popliteal LNs was assessed by immunochemistry. Indocyanine green and its transport within lymphatic vessels were readily visualized, and quantitative measures were derived. During the acute phase of arthritis, the lymphatic vessels were dilated, with increased indocyanine green signal intensity and lymphatic pulses, and popliteal LNs became fluorescent quickly. During the chronic phase, new lymphatic vessels were present near the foot. However, the appearance of indocyanine green in lymphatic vessels was delayed. The size and area of popliteal LN lymphatic sinuses progressively increased in the K/BxN mice. Our findings indicate that indocyanine green near-infrared lymphatic imaging is a valuable method for assessing the lymphatic draining function in mice with inflammatory arthritis. Indocyanine green-near-infrared imaging of K/BxN mice identified 2 distinct lymphatic phenotypes during the acute and chronic phase of inflammation. This technique can be used to assess new therapies for lymphatic disorders.

Near infrared lymphatic imaging demonstrates the dynamics of lymph flow and lymphangiogenesis during the acute vs. chronic phases of arthritis in mice

PubMed Central

Zhou, Quan; Wood, Ronald; Schwarz, Edward M.; Wang, Yong-Jun; Xing, Lianping

2010-01-01

Objective Development of an in vivo imaging method to assess lymphatic draining function in the K/B×N mouse model of inflammatory arthritis. Methods Indocyanine green (ICG), a near-infrared (NIR) fluorescent dye, was injected intradermally into the footpad of wild-type mice, the limb was illuminated with an 806 nm NIR laser, and the movement of ICG from the injection site to the draining popliteal lymph node (PLN) was recorded with a CCD camera. ICG-NIR images were analyzed to obtain 5 measures of lymphatic function across time. K/B×N arthritic mice and control non-arthritic littermates were imaged at one-month of age when acute joint inflammation commenced, and repeated at 3 months when joint inflammation became chronic. Lymphangiogenesis in PLNs was assessed by immunochemistry. Results ICG and its transport within lymphatic vessels were readily visualized and quantitative measures derived. During the acute phase of arthritis, the lymphatic vessels were dilated with increased ICG signal intensity and lymphatic pulses, and PLNs became fluorescent quickly. During the chronic phase, new lymphatic vessels were present near the foot. However, ICG appearance in lymphatic vessels was delayed. The size and area of PLN lymphatic sinuses progressively increased in the K/B×N mice. Conclusion ICG-NIR lymphatic imaging is a valuable method to assess the lymphatic draining function in mice with inflammatory arthritis. ICG-NIR imaging of K/B×N mice identified two distinct lymphatic phenotypes during the acute and chronic phase of inflammation. This technique can be used to assess new therapies for lymphatic disorders. PMID:20309866

Increased pain and neurogenic inflammation in mice deficient of neutral endopeptidase.

PubMed

Krämer, Heidrun H; He, Lan; Lu, Bao; Birklein, Frank; Sommer, Claudia

2009-08-01

The complex regional pain syndrome (CRPS) is characterized by enhanced neurogenic inflammation, mediated by neuropeptides. Neutral endopeptidase (NEP) is a key enzyme in neuropeptide catabolism. We used NEP knock out (ko) mice to investigate whether NEP deficiency leads to increased pain behavior and signs of neurogenic inflammation after soft tissue trauma with and without nerve injury. After chronic constriction injury (CCI) of the right sciatic nerve, NEP ko mice were more sensitive to heat, to mechanical stimuli, and to cold than wild type mice. Tissue injury without nerve injury produced no differences between genotypes. After CCI, NEP ko mice showed increased hind paw edema but lower skin temperatures than wild type mice. Substance P (SP) and endothelin 1 (ET 1) determined by enzyme immuno assay (EIA) were increased in sciatic nerves from NEP ko mice after CCI. Tissue CGRP content did not differ between the genotypes. The results provide evidence that pain behavior and neurogenic inflammation are enhanced in NEP ko mice after nerve injury. These findings resemble human 'cold' CRPS and suggest that ET 1 plays an important role in the pathogenesis of CRPS with nerve injury.

Induction of Type I Interferons by Therapeutic Nanoparticle-Based Vaccination Is Indispensable to Reinforce Cytotoxic CD8+ T Cell Responses During Chronic Retroviral Infection

PubMed Central

Knuschke, Torben; Rotan, Olga; Bayer, Wibke; Kollenda, Sebastian; Dickow, Julia; Sutter, Kathrin; Hansen, Wiebke; Dittmer, Ulf; Lang, Karl S.; Epple, Matthias; Buer, Jan; Westendorf, Astrid M.

2018-01-01

T cell dysfunction and immunosuppression are characteristic for chronic viral infections and contribute to viral persistence. Overcoming these burdens is the goal of new therapeutic strategies to cure chronic infectious diseases. We recently described that therapeutic vaccination of chronic retrovirus infected mice with a calcium phosphate (CaP) nanoparticle (NP)-based vaccine carrier, functionalized with CpG and viral peptides is able to efficiently reactivate the CD8+ T cell response and improve the eradication of virus infected cells. However, the mechanisms underlying this effect were largely unclear. While type I interferons (IFNs I) are considered to drive T cell exhaustion by persistent immune activation during chronic viral infection, we here describe an indispensable role of IFN I induced by therapeutic vaccination to efficiently reinforce cytotoxic CD8+ T cells (CTL) and improve control of chronic retroviral infection. The induction of IFN I is CpG dependent and leads to significant IFN signaling indicated by upregulation of IFN stimulated genes. By vaccinating chronically retrovirus-infected mice lacking the IFN I receptor (IFNAR−/−) or by blocking IFN I signaling in vivo during therapeutic vaccination, we demonstrate that IFN I signaling is necessary to drive full reactivation of CTLs. Surprisingly, we also identified an impaired suppressive capability of regulatory T cells in the presence of IFNα, which implicates an important role for vaccine-induced IFNα in the regulation of the T cell response during chronic retroviral infection. Our data suggest that inducing IFN I signaling in conjunction with the presentation of viral antigens can reactivate immune functions and reduce viral loads in chronic infections. Therefore, we propose CaP NPs as potential therapeutic tool to treat chronic infections. PMID:29740425

Hepatitis virus infection affects DNA methylation in mice with humanized livers.

PubMed

Okamoto, Yasuyuki; Shinjo, Keiko; Shimizu, Yasuhiro; Sano, Tsuyoshi; Yamao, Kenji; Gao, Wentao; Fujii, Makiko; Osada, Hirotaka; Sekido, Yoshitaka; Murakami, Shuko; Tanaka, Yasuhito; Joh, Takashi; Sato, Shinya; Takahashi, Satoru; Wakita, Takaji; Zhu, Jingde; Issa, Jean-Pierre J; Kondo, Yutaka

2014-02-01

Cells of tumors associated with chronic inflammation frequently have altered patterns of DNA methylation, including hepatocellular carcinomas. Chronic hepatitis has also been associated with aberrant DNA methylation, but little is known about their relationship. Pyrosequencing was used to determine the methylation status of cultured Huh7.5.1 hepatoma cells after hepatitis C virus (HCV) infection. We also studied mice with severe combined immunodeficiency carrying the urokinase-type plasminogen activator transgene controlled by an albumin promoter (urokinase-type plasminogen activator/severe combined immunodeficient mice), in which up to 85% of hepatocytes were replaced by human hepatocytes (chimeric mice). Mice were given intravenous injections of hepatitis B virus (HBV) or HCV, liver tissues were collected, and DNA methylation profiles were determined at different time points after infection. We also compared methylation patterns between paired samples of hepatocellular carcinomas and adjacent nontumor liver tissues from patients. No reproducible changes in DNA methylation were observed after infection of Huh7.5.1 cells with HCV. Livers from HBV- and HCV-infected mice had genome-wide, time-dependent changes in DNA methylation, compared with uninfected urokinase-type plasminogen activator/severe combined immunodeficient mice. There were changes in 160 ± 63 genes in HBV-infected and 237 ± 110 genes in HCV-infected mice. Methylation of 149 common genes increased in HBV- and HCV-infected mice; methylation of some of these genes also increased in hepatocellular carcinoma samples from patients compared with nontumor tissues. Expression of Ifng, which is expressed by natural killer cells, increased significantly in chimeric livers, in concordance with induction of DNA methylation, after infection with HBV or HCV. Induction of Ifng was reduced after administration of an inhibitor of natural killer cell function (anti-asialo GM1). In chimeric mice with humanized livers, infection with HBV and HCV appears to activate a natural kill cell-dependent innate immune response. This contributes to the induction and accumulation of aberrant DNA methylation in human hepatocytes. Copyright © 2014 AGA Institute. Published by Elsevier Inc. All rights reserved.

[Upregulation of P2X3 receptors in dorsal root ganglion of TRPV1 knockout female mice].

PubMed

Fang, Xiao; Shi, Xiao-Han; Huang, Li-Bin; Rong, Wei-Fang; Ma, Bei

2014-08-25

The study was aimed to investigate the changes in mechanical pain threshold in the condition of chronic inflammatory pain after transient receptor potential vanilloid 1 (TRPV1) gene was knockout. Hind-paw intraplantar injection of complete freund's adjuvant (CFA, 20 μL) produced peripheral inflammation in wild-type and TRPV1 knockout female mice. The mechanical pain thresholds were measured during the 8 days after injection and pre-injection by using Von-Frey hair. Nine days after injection, mice were killed and the differences of expression of c-Fos and P2X3 receptor in the dorsal root ganglia (DRG) and spinal cord dorsal horn were examined by Western blotting between the two groups. Compared with that in wild-type mice, the mechanical pain threshold was increased significantly in TRPV1 knockout mice (P < 0.05); 3 days after CFA injection, the baseline mechanical pain threshold in the TRPV1 knockout mice group was significantly higher than that in the wild-type mice group (P < 0.05); The result of Western blotting showed that the expression of c-Fos protein both in DRG and spinal cord dorsal horn of TRPV1 knockout mice group was decreased significantly compared with that in wild-type mice group (P < 0.01, P < 0.05), while the expression of P2X3 receptor in DRG of TRPV1 knockout mice group was increased significantly compared with that in wild-type mice group (P < 0.05). Our findings indicate that TRPV1 may influence the peripheral mechanical pain threshold by mediating the expression of c-Fos protein both in DRG and spinal cord dorsal horn and changing the expression of P2X3 receptor in DRG.

Chronic alterations in growth hormone/insulin-like growth factor-I signaling lead to changes in mouse tendon structure.

PubMed

Nielsen, R H; Clausen, N M; Schjerling, P; Larsen, J O; Martinussen, T; List, E O; Kopchick, J J; Kjaer, M; Heinemeier, K M

2014-02-01

The growth hormone/insulin-like growth factor-I (GH/IGF-I) axis is an important stimulator of collagen synthesis in connective tissue, but the effect of chronically altered GH/IGF-I levels on connective tissue of the muscle-tendon unit is not known. We studied three groups of mice; 1) giant transgenic mice that expressed bovine GH (bGH) and had high circulating levels of GH and IGF-I, 2) dwarf mice with a disrupted GH receptor gene (GHR-/-) leading to GH resistance and low circulating IGF-I, and 3) a wild-type control group (CTRL). We measured the ultra-structure, collagen content and mRNA expression (targets: GAPDH, RPLP0, IGF-IEa, IGF-IR, COL1A1, COL3A1, TGF-β1, TGF-β2, TGF-β3, versican, scleraxis, tenascin C, fibronectin, fibromodulin, decorin) in the Achilles tendon, and the mRNA expression was also measured in calf muscle (same targets as tendon plus IGF-IEb, IGF-IEc). We found that GHR-/- mice had significantly lower collagen fibril volume fraction in Achilles tendon, as well as decreased mRNA expression of IGF-I isoforms and collagen types I and III in muscle compared to CTRL. In contrast, the mRNA expression of IGF-I isoforms and collagens in bGH mice was generally high in both tendon and muscle compared to CTRL. Mean collagen fibril diameter was significantly decreased with both high and low GH/IGF-I signaling, but the GHR-/- mouse tendons were most severely affected with a total loss of the normal bimodal diameter distribution. In conclusion, chronic manipulation of the GH/IGF-I axis influenced both morphology and mRNA levels of selected genes in the muscle-tendon unit of mice. Whereas only moderate structural changes were observed with up-regulation of GH/IGF-I axis, disruption of the GH receptor had pronounced effects upon tendon ultra-structure. © 2013.

GABAA Receptor Regulation of Voluntary Ethanol Drinking Requires PKCε

PubMed Central

Besheer, Joyce; Lepoutre, Veronique; Mole, Beth; Hodge, Clyde W.

2010-01-01

Protein kinase C (PKC) regulates a variety of neural functions, including ion channel activity, neurotransmitter release, receptor desensitization and differentiation. We have shown previously that mice lacking the ε-isoform of PKC (PKCε) self-administer 75% less ethanol and exhibit supersensitivity to acute ethanol and allosteric positive modulators of GABAA receptors when compared with wild-type controls. The purpose of the present study was to examine involvement of PKCε in GABAA receptor regulation of voluntary ethanol drinking. To address this question, PKCε null-mutant and wild-type control mice were allowed to drink ethanol (10% v/v) vs. water on a two-bottle continuous access protocol. The effects of diazepam (nonselective GABAA BZ positive modulator), zolpidem (GABAA α1 agonist), L-655,708 (BZ-sensitive GABAA α5 inverse agonist), and flumazenil (BZ antagonist) were then tested on ethanol drinking. Ethanol intake (grams/kg/day) by wild-type mice decreased significantly after diazepam or zolpidem but increased after L-655,708 administration. Flumazenil antagonized diazepam-induced reductions in ethanol drinking in wild-type mice. However, ethanol intake by PKCε null mice was not altered by any of the GABAergic compounds even though effects were seen on water drinking in these mice. Increased acute sensitivity to ethanol and diazepam, which was previously reported, was confirmed in PKCε null mice. Thus, results of the present study show that PKCε null mice do not respond to doses of GABAA BZ receptor ligands that regulate ethanol drinking by wild-type control mice. This suggests that PKCε may be required for GABAA receptor regulation of chronic ethanol drinking. PMID:16881070

Effect of Dietary Treatment with Dimethylarsinous Acid (DMAIII) on the Urinary Bladder Epithelium of Arsenic (+3 Oxidation State) Methyltransferase (As3mt) Knockout and C57BL/6 Wild Type Female Mice

EPA Science Inventory

Abstract Chronic exposure to inorganic arsenic (iAs) is carcinogenic to the human urinary bladder. It produces urothelial cytotoxicity and proliferation in rats and mice. DMAv, a major methylated urinary metabolite of iAs, is a rat bladder carcinogen, but without effects on the...

Tempol Supplementation Restores Diaphragm Force and Metabolic Enzyme Activities in mdx Mice

PubMed Central

Burns, David P.; Ali, Izza; Rieux, Clement; Healy, James; Jasionek, Greg; O’Halloran, Ken D.

2017-01-01

Duchenne muscular dystrophy (DMD) is characterized by striated muscle weakness, cardiomyopathy, and respiratory failure. Since oxidative stress is recognized as a secondary pathology in DMD, the efficacy of antioxidant intervention, using the superoxide scavenger tempol, was examined on functional and biochemical status of dystrophin-deficient diaphragm muscle. Diaphragm muscle function was assessed, ex vivo, in adult male wild-type and dystrophin-deficient mdx mice, with and without a 14-day antioxidant intervention. The enzymatic activities of muscle citrate synthase, phosphofructokinase, and lactate dehydrogenase were assessed using spectrophotometric assays. Dystrophic diaphragm displayed mechanical dysfunction and altered biochemical status. Chronic tempol supplementation in the drinking water increased diaphragm functional capacity and citrate synthase and lactate dehydrogenase enzymatic activities, restoring all values to wild-type levels. Chronic supplementation with tempol recovers force-generating capacity and metabolic enzyme activity in mdx diaphragm. These findings may have relevance in the search for therapeutic strategies in neuromuscular disease. PMID:29210997

Transmission and adaptation of chronic wasting disease to hamsters and transgenic mice: evidence for strains.

PubMed

Raymond, Gregory J; Raymond, Lynne D; Meade-White, Kimberly D; Hughson, Andrew G; Favara, Cynthia; Gardner, Donald; Williams, Elizabeth S; Miller, Michael W; Race, Richard E; Caughey, Byron

2007-04-01

In vitro screening using the cell-free prion protein conversion system indicated that certain rodents may be susceptible to chronic wasting disease (CWD). Therefore, CWD isolates from mule deer, white-tailed deer, and elk were inoculated intracerebrally into various rodent species to assess the rodents' susceptibility and to develop new rodent models of CWD. The species inoculated were Syrian golden, Djungarian, Chinese, Siberian, and Armenian hamsters, transgenic mice expressing the Syrian golden hamster prion protein, and RML Swiss and C57BL10 wild-type mice. The transgenic mice and the Syrian golden, Chinese, Siberian, and Armenian hamsters had limited susceptibility to certain of the CWD inocula, as evidenced by incomplete attack rates and long incubation periods. For serial passages of CWD isolates in Syrian golden hamsters, incubation periods rapidly stabilized, with isolates having either short (85 to 89 days) or long (408 to 544 days) mean incubation periods and distinct neuropathological patterns. In contrast, wild-type mouse strains and Djungarian hamsters were not susceptible to CWD. These results show that CWD can be transmitted and adapted to some species of rodents and suggest that the cervid-derived CWD inocula may have contained or diverged into at least two distinct transmissible spongiform encephalopathy strains.

Inhibition of G0/G1 Switch 2 Ameliorates Renal Inflammation in Chronic Kidney Disease.

PubMed

Matsunaga, Naoya; Ikeda, Eriko; Kakimoto, Keisuke; Watanabe, Miyako; Shindo, Naoya; Tsuruta, Akito; Ikeyama, Hisako; Hamamura, Kengo; Higashi, Kazuhiro; Yamashita, Tomohiro; Kondo, Hideaki; Yoshida, Yuya; Matsuda, Masaki; Ogino, Takashi; Tokushige, Kazutaka; Itcho, Kazufumi; Furuichi, Yoko; Nakao, Takaharu; Yasuda, Kaori; Doi, Atsushi; Amamoto, Toshiaki; Aramaki, Hironori; Tsuda, Makoto; Inoue, Kazuhide; Ojida, Akio; Koyanagi, Satoru; Ohdo, Shigehiro

2016-11-01

Chronic kidney disease (CKD) is a global health problem, and novel therapies to treat CKD are urgently needed. Here, we show that inhibition of G 0 /G 1 switch 2 (G0s2) ameliorates renal inflammation in a mouse model of CKD. Renal expression of chemokine (C-C motif) ligand 2 (Ccl2) was increased in response to p65 activation in the kidneys of wild-type 5/6 nephrectomy (5/6Nx) mice. Moreover, 5/6Nx Clk/Clk mice, which carry homozygous mutations in the gene encoding circadian locomotor output cycles kaput (CLOCK), did not exhibit aggravation of apoptosis or induction of F4/80-positive cells. The renal expression of G0s2 in wild-type 5/6Nx mice was important for the transactivation of Ccl2 by p65. These pathologies were ameliorated by G0s2 knockdown. Furthermore, a novel small-molecule inhibitor of G0s2 expression was identified by high-throughput chemical screening, and the inhibitor suppressed renal inflammation in 5/6Nx mice. These findings indicated that G0s2 inhibitors may have applications in the treatment of CKD. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

Maintenance of memory-type pathogenic Th2 cells in the pathophysiology of chronic airway inflammation.

PubMed

Hirahara, Kiyoshi; Shinoda, Kenta; Endo, Yusuke; Ichikawa, Tomomi; Nakayama, Toshinori

2018-01-01

Immunological memory is critical for long-standing protection against microorganisms; however, certain antigen-specific memory CD4 + T helper (Th) cells drive immune-related pathology, including chronic allergic inflammation such as asthma. The IL-5-producing memory-type Tpath2 subset is important for the pathogenesis of chronic allergic inflammation. This memory-type pathogenic Th2 cell population (Tpath2) can be detected in various allergic inflammatory lesions. However, how these pathogenic populations are maintained at the local inflammatory site has remained unclear. We performed a series of experiments using mice model for chronic airway inflammation. We also investigated the human samples from patients with eosinophilic chronic rhinosinusitis. We recently reported that inducible bronchus-associated lymphoid tissue (iBALT) was shaped during chronic inflammation in the lung. We also found that memory-type Tpath2 cells are maintained within iBALT. The maintenance of the Tpath2 cells within iBALT is supported by specific cell subpopulations within the lung. Furthermore, ectopic lymphoid structures consisting of memory CD4 + T cells were found in nasal polyps of eosinophilic chronic rhinosinusitis patients, indicating that the persistence of inflammation is controlled by these structures. Thus, the cell components that organize iBALT formation may be therapeutic targets for chronic allergic airway inflammation.

Chronic antioxidant therapy reduces oxidative stress in a mouse model of Alzheimer's disease.

PubMed

Siedlak, Sandra L; Casadesus, Gemma; Webber, Kate M; Pappolla, Miguel A; Atwood, Craig S; Smith, Mark A; Perry, George

2009-02-01

Oxidative modifications are a hallmark of oxidative imbalance in the brains of individuals with Alzheimer's, Parkinson's and prion diseases and their respective animal models. While the causes of oxidative stress are relatively well-documented, the effects of chronically reducing oxidative stress on cognition, pathology and biochemistry require further clarification. To address this, young and aged control and amyloid-beta protein precursor-over-expressing mice were fed a diet with added R-alpha lipoic acid for 10 months to determine the effect of chronic antioxidant administration on the cognition and neuropathology and biochemistry of the brain. Both wild type and transgenic mice treated with R-alpha lipoic acid displayed significant reductions in markers of oxidative modifications. On the other hand, R-alpha lipoic acid had little effect on Y-maze performance throughout the study and did not decrease end-point amyloid-beta load. These results suggest that, despite the clear role of oxidative stress in mediating amyloid pathology and cognitive decline in ageing and AbetaPP-transgenic mice, long-term antioxidant therapy, at levels within tolerable nutritional guidelines and which reduce oxidative modifications, have limited benefit.

Hepcidin regulation in wild-type and Hfe knockout mice in response to alcohol consumption: evidence for an alcohol-induced hypoxic response.

PubMed

Heritage, Mandy L; Murphy, Therese L; Bridle, Kim R; Anderson, Gregory J; Crawford, Darrell H G; Fletcher, Linda M

2009-08-01

Expression of Hamp1, the gene encoding the iron regulatory peptide hepcidin, is inappropriately low in HFE-associated hereditary hemochromatosis and Hfe knockout mice (Hfe(-/-)). Since chronic alcohol consumption is also associated with disturbances in iron metabolism, we investigated the effects of alcohol consumption on hepcidin mRNA expression in Hfe(-/-) mice. Hfe(-/-) and C57BL/6 (wild-type) mice were pair-fed either an alcohol liquid diet or control diet for up to 8 weeks. The mRNA levels of hepcidin and ferroportin were measured at the mRNA level by RT-PCR and protein expression of hypoxia inducible factor-1 alpha (HIF-1alpha) was measured by western blot. Hamp1 mRNA expression was significantly decreased and duodenal ferroportin expression was increased in alcohol-fed wild-type mice at 8 weeks. Time course experiments showed that the decrease in hepcidin mRNA was not immediate, but was significant by 4 weeks. Consistent with the genetic defect, Hamp1 mRNA was decreased and duodenal ferroportin mRNA expression was increased in Hfe(-/-) mice fed on the control diet compared with wild-type animals and alcohol further exacerbated these effects. HIF-1alpha protein levels were elevated in alcohol-fed wild-type animals compared with controls. Alcohol may decrease Hamp1 gene expression independently of the HFE pathway possibly via alcohol-induced hypoxia.

Overexpression of TGF-alpha increases lung tissue hysteresivity in transgenic mice.

PubMed

Pillow, J J; Korfhagen, T R; Ikegami, M; Sly, P D

2001-12-01

Increased transforming growth factor (TGF)-alpha has been observed in neonatal chronic lung disease. Lungs of transgenic mice that overexpress TGF-alpha develop enlarged air spaces and pulmonary fibrosis compared with wild-type mice. We hypothesized that these pathological changes may alter the mechanical coupling of viscous and elastic forces within lung parenchyma. Respiratory impedance was measured in open-chested, tracheostomized adult wild-type and TGF-alpha mice by using the forced oscillation technique (0.25-19.63 Hz) delivered by flexiVent (Scireq, Montreal, PQ). Estimates of airway resistance (Raw), inertance (I), and the coefficients of tissue damping (G(L)) and tissue elastance (H(L)) were obtained by fitting a model to each impedance spectrum. Hysteresivity (eta) was calculated as G(L)/H(L). There was a significant increase in eta (P < 0.01) and a trend to a decrease in H(L) (P = 0.07) of TGF-alpha mice compared with the wild-type group. There was no significant change in Raw, I, or G(L). Structural abnormality present in the lungs of adult TGF-alpha mice alters viscoelastic coupling of the tissues, as evidenced by a change in eta.

The role of CYP2A5 in liver injury and fibrosis: chemical-specific difference

PubMed Central

Hong, Feng; Si, Chuanping; Gao, Pengfei; Cederbaum, Arthur I.; Xiong, Huabao; Lu, Yongke

2015-01-01

Liver injuries induced by carbon tetrachloride (CCL4) or thioacetamide (TAA) are dependent on cytochrome P450 2E1 (CYP2E1). CYP2A5 can be induced by TAA but not by CCL4. In this study, liver injury including fibrosis induced by CCL4 or TAA were investigated in wild type (WT) mice and CYP2A5 knockout (cyp2a5−/−) mice as well as in CYP2E1 knockout (cyp2e1−/−) mice as a comparison. Acute and sub-chronic liver injuries including fibrosis were induced by CCL4 and TAA in WT mice but not in cyp2e1−/− mice, confirming the indispensable role of CYP2E1 in CCL4 and TAA hepatotoxicity. WT mice and cyp2a5−/− mice developed comparable acute liver injury induced by a single injection of CCL4 as well as sub-chronic liver injury including fibrosis induced by one month of repeated administration of CCL4, suggesting that CYP2A5 does not affect CCL4-induced liver injury and fibrosis. However, while 200 mg/kg TAA-induced acute liver injury was comparable in WT mice and cyp2a5−/− mice, 75 and 100 mg/kg TAA-induced liver injury were more severe in cyp2a5−/− mice than those found in WT mice. After multiple injections with 200 mg/kg TAA for one month, while sub-chronic liver injury as indicated by serum aminotransferases was comparable in WT mice and cyp2a5−/− mice, liver fibrosis was more severe in cyp2a5−/− mice than that found in WT mice. These results suggest that while both CCL4- and TAA-induced liver injuries and fibrosis are CYP2E1 dependent, under some conditions, CYP2A5 may protect against TAA-induced liver injury and fibrosis, but it doesn’t affect CCL4 hepatotoxicity. PMID:26363552

Relative adrenal insufficiency in mice deficient in 5α-reductase 1

PubMed Central

Livingstone, Dawn E W; Di Rollo, Emma M; Yang, Chenjing; Codrington, Lucy E; Mathews, John A; Kara, Madina; Hughes, Katherine A; Kenyon, Christopher J; Walker, Brian R; Andrew, Ruth

2014-01-01

Patients with critical illness or hepatic failure exhibit impaired cortisol responses to ACTH, a phenomenon known as ‘relative adrenal insufficiency’. A putative mechanism is that elevated bile acids inhibit inactivation of cortisol in liver by 5α-reductases type 1 and type 2 and 5β-reductase, resulting in compensatory downregulation of the hypothalamic–pituitary–adrenal axis and adrenocortical atrophy. To test the hypothesis that impaired glucocorticoid clearance can cause relative adrenal insufficiency, we investigated the consequences of 5α-reductase type 1 deficiency in mice. In adrenalectomised male mice with targeted disruption of 5α-reductase type 1, clearance of corticosterone was lower after acute or chronic (eightfold, P<0.05) administration, compared with WT control mice. In intact 5α-reductase-deficient male mice, although resting plasma corticosterone levels were maintained, corticosterone responses were impaired after ACTH administration (26% lower, P<0.05), handling stress (2.5-fold lower, P<0.05) and restraint stress (43% lower, P<0.05) compared with WT mice. mRNA levels of Nr3c1 (glucocorticoid receptor), Crh and Avp in pituitary or hypothalamus were altered, consistent with enhanced negative feedback. These findings confirm that impaired peripheral clearance of glucocorticoids can cause ‘relative adrenal insufficiency’ in mice, an observation with important implications for patients with critical illness or hepatic failure, and for patients receiving 5α-reductase inhibitors for prostatic disease. PMID:24872577

Obesity-induced endoplasmic reticulum stress causes chronic inflammation in adipose tissue.

PubMed

Kawasaki, Noritaka; Asada, Rie; Saito, Atsushi; Kanemoto, Soshi; Imaizumi, Kazunori

2012-01-01

Adipose tissue plays a central role in maintaining metabolic homeostasis under normal conditions. Metabolic diseases such as obesity and type 2 diabetes are often accompanied by chronic inflammation and adipose tissue dysfunction. In this study, we observed that endoplasmic reticulum (ER) stress and the inflammatory response occurred in adipose tissue of mice fed a high-fat diet for a period of 16 weeks. After 16 weeks of feeding, ER stress markers increased and chronic inflammation occurred in adipose tissue. We found that ER stress is induced by free fatty acid (FFA)-mediated reactive oxygen species (ROS) generation and up-regulated gene expression of inflammatory cytokines in 3T3-L1 adipocytes. Oral administration to obese mice of chemical chaperons, which alleviate ER stress, improved chronic inflammation in adipose tissue, followed by the suppression of increased body weight and improved insulin signaling. These results indicate that ER stress plays important pathophysiological roles in obesity-induced adipose tissue dysfunction.

Chronic treatment with LY341495 decreases 5-HT2A receptor binding and hallucinogenic effects of LSD in mice

PubMed Central

Moreno, José L.; Holloway, Terrell; Rayannavar, Vinayak; Sealfon, Stuart C.; González-Maeso, Javier

2013-01-01

Hallucinogenic drugs, such as lysergic acid diethylamide (LSD), mescaline and psilocybin, alter perception and cognitive processes. All hallucinogenic drugs have in common a high affinity for the serotonin 5-HT2A receptor. Metabotropic glutamate 2/3 (mGlu2/3) receptor ligands show efficacy in modulating the cellular and behavioral responses induced by hallucinogenic drugs. Here, we explored the effect of chronic treatment with the mGlu2/3 receptor antagonist 2S-2-amino-2-(1S,2S-2-carboxycyclopropan-1-yl)-3-(xanth-9-yl)-propionic acid (LY341495) on the hallucinogenic-like effects induced by LSD (0.24 mg/kg). Mice were chronically (21 days) treated with LY341495 (1.5 mg/kg), or vehicle, and experiments were carried out one day after the last injection. Chronic treatment with LY341495 down-regulated [3H]ketanserin binding in somatosensory cortex of wild-type, but not mGlu2 knockout (KO), mice. Head-twitch behavior, and expression of c-fos, egr-1 and egr-2, which are responses induced by hallucinogenic 5-HT2A agonists, were found to be significantly decreased by chronic treatment with LY341495. These findings suggest that repeated blockade of the mGlu2 receptor by LY341495 results in reduced 5-HT2A receptor-dependent hallucinogenic effects of LSD. PMID:23333599

[Radiation exposure of cultured tissue cells and animals (mice) within 10-kilometers zone of accident at Chernobyl nuclear plant. Effect on radiosensitivity to future radiation].

PubMed

Pelevina, I I; Afanasév, G G; Gotlib, V Ia; Alferovich, A A; Antoshchina, M M; Riabchenko, N I; Saenko, A S; Riabtsev, I A; Riabov, I N

1993-01-01

The effect of chronic low-level radiation exposure on radiosensitivity to posterior acute irradiation at high doses has been studied. Cells and mice were exposed within the ten-kilometer zone of Chernobyl disaster during various spaces of time (1-12 days), then over one or more days were additionally irradiated by doses of 1-4 Gy. It was shown that no adaptive response was developed under chronic exposure of cells and mice within the zone of disaster. On the contrary increased sensitivity to posterior irradiation was revealed. The number of cytogenetic damages of cultured tissue cells and marrow cells (chromosome aberrations and micronuclei) increases, the spectrum of aberrations being shifted to chromosome type, cells with multiaberration appearing. The decay of chromatine increases indicating an interphase death; the number of leucocytes in peripheral blood decreases.

Ethanol Induction of CYP2A5: Role of CYP2E1-ROS-Nrf2 Pathway

PubMed Central

Lu, Yongke; Zhang, Xu Hannah

2012-01-01

Chronic ethanol consumption was previously shown to induce CYP2A5 in mice, and this induction of CYP2A5 by ethanol was CYP2E1 dependent. In this study, the mechanisms of CYP2E1-dependent ethanol induction of CYP2A5 were investigated. CYP2E1 was induced by chronic ethanol consumption to the same degree in wild-type (WT) mice and CYP2A5 knockout (Cyp2a5 –/–) mice, suggesting that unlike the CYP2E1-dependent ethanol induction of CYP2A5, ethanol induction of CYP2E1 is not CYP2A5 dependent. Microsomal ethanol oxidation was about 25% lower in Cyp2a5 –/– mice compared with that in WT mice, suggesting that CYP2A5 can oxidize ethanol although to a lesser extent than CYP2E1 does. CYP2A5 was induced by short-term ethanol consumption in human CYP2E1 transgenic knockin (Cyp2e1 –/– KI) mice but not in CYP2E1 knockout (Cyp2e1 –/–) mice. The redox-sensitive transcription factor nuclear factor-erythroid 2-related factor 2 (Nrf2) was also induced by acute ethanol in Cyp2e1 –/– KI mice but not in Cyp2e1 –/– mice. Ethanol induction of CYP2A5 in Nrf2 knockout (Nrf2 –/–) mice was lower compared with that in WT mice, whereas CYP2E1 induction by ethanol was comparable in WT and Nrf2 –/– mice. Antioxidants (N-acetyl-cysteine and vitamin C), which blocked oxidative stress induced by chronic ethanol in WT mice and acute ethanol in Cyp2e1 –/– KI mice, also blunted the induction of CYP2A5 and Nrf2 by ethanol but not the induction of CYP2E1 by ethanol. These results suggest that oxidative stress induced by ethanol via induction of CYP2E1 upregulates Nrf2 activity, which in turn regulates ethanol induction of CYP2A5. Results obtained from primary hepatocytes, mice gavaged with binge ethanol or fed chronic ethanol, show that Nrf2-regulated ethanol induction of CYP2A5 protects against ethanol-induced steatosis. PMID:22552773

Diabetes accelerates retinal ganglion cell dysfunction in mice lacking sigma receptor 1.

PubMed

Ha, Yonju; Saul, Alan; Tawfik, Amany; Zorrilla, Eric P; Ganapathy, Vadivel; Smith, Sylvia B

2012-01-01

Sigma receptor 1 (σR1) is a non-opioid transmembrane protein that may act as a molecular chaperone at the endoplasmic reticulum-mitochondrial membrane. Ligands for σR1, such as (+)-pentazocine [(+)-PTZ], confer marked retinal neuroprotection in vivo and in vitro. Recently we analyzed the retinal phenotype of mice lacking σR1 (σR1 KO) and observed normal retinal morphology and function in young mice (5-30 weeks) but diminished negative scotopic threshold responses (nSTRs), retinal ganglion cell (RGC) loss, and disruption of optic nerve axons consistent with inner retinal dysfunction by 1 year. These data led us to test the hypothesis that σR1 may be critical in forestalling chronic retinal stress; diabetes was used as the model of chronic stress. To determine whether σR1 is required for (+)-PTZ neuroprotective effects, primary RGCs isolated from wild-type (WT) and σR1 KO mice were exposed to xanthine-xanthine oxidase (10 µM:2 mU/ml) to induce oxidative stress in the presence or absence of (+)-PTZ. Cell death was evaluated by terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) analysis. To assess effects of chronic stress on RGC function, diabetes was induced in 3-week C57BL/6 (WT) and σR1 KO mice, using streptozotocin to yield four groups: WT nondiabetic (WT non-DB), WT diabetic (WT-DB), σR1 KO non-DB, and σR1 KO-DB. After 12 weeks of diabetes, when mice were 15-weeks old, intraocular pressure (IOP) was recorded, electrophysiologic testing was performed (including detection of nSTRs), and the number of RGCs was counted in retinal histological sections. In vitro studies showed that (+)-PTZ could not prevent oxidative stress-induced death of RGCs harvested from σR1 KO mice but afforded robust protection against death of RGCs harvested from WT mice. In the studies of chronic stress induced by diabetes, the IOP measured in the four mouse groups was within the normal range; however, there was a significant increase in the IOP of σR1 KO-DB mice (16 ± 0.5 mmHg) compared to the other groups tested (σR1 KO non-DB, WT non-DB, WT-DB: ~12 ± 0.6 mmHg). Regarding electrophysiologic testing, the nSTRs of σR1 KO non-DB mice were similar to WT non-DB mice at 15 weeks; however, they were significantly lower in σR1 KO-DB mice (5 ± 1 µV) compared to the other groups, including, notably, σR1 KO-nonDB (12±2 µV). As expected, the number of RGCs in σR1 KO non-DB mice was similar to WT non-DB mice at 15 weeks, but under chronic stress of diabetes there were fewer RGCs in retinas of σR1 KO-DB mice. This is the first report showing unequivocally that the neuroprotective effects of (+)-PTZ require σR1. σR1 KO mice show normal retinal structure and function at young ages; however, when subjected to the chronic stress of diabetes, there is an acceleration of retinal functional deficits in σR1 KO mice such that ganglion cell dysfunction is observed at a much earlier age than nondiabetic σR1 KO mice. The data support the hypothesis that σR1 plays a key role in modulating retinal stress and may be an important target for retinal disease.

Upregulation of Cannabinoid Type 1 Receptors in Dopamine D2 Receptor Knockout Mice Is Reversed by Chronic Forced Ethanol Consumption

DOE Office of Scientific and Technical Information (OSTI.GOV)

Thanos, P.K.; Wang, G.; Thanos, P.K.

2011-01-01

The anatomical proximity of the cannabinoid type 1 (CNR1/CB1R) and the dopamine D2 receptors (DRD2), their ability to form CB1R-DRD2 heteromers, their opposing roles in locomotion, and their involvement in ethanol's reinforcing and addictive properties prompted us to study the levels and distribution of CB1R after chronic ethanol intake, in the presence and absence of DRD2. We monitored the drinking patterns and locomotor activity of Drd2+/+ and Drd2-/- mice consuming either water or a 20% (v/v) ethanol solution (forced ethanol intake) for 6 months and used the selective CB1 receptor antagonist [{sup 3}H]SR141716A to quantify CB1R levels in different brainmore » regions with in vitro receptor autoradiography. We found that the lack of DRD2 leads to a marked upregulation (approximately 2-fold increase) of CB1R in the cerebral cortex, the caudate-putamen, and the nucleus accumbens, which was reversed by chronic ethanol intake. The results suggest that DRD2-mediated dopaminergic neurotransmission and chronic ethanol intake exert an inhibitory effect on cannabinoid receptor expression in cortical and striatal regions implicated in the reinforcing and addictive properties of ethanol.« less

Experimental Paracoccidioidomycosis in Mice

PubMed Central

Linares, Leonor I.; Friedman, Lorraine

1972-01-01

Virulence and infectivity of nine strains of Paracoccidioides brasiliensis were investigated in groups of mice which were inoculated intranasally or intravenously, and some of each were treated with corticosteroids. Fatal infections were not often seen among untreated mice, but mortality usually occurred when corticosteroids were given, regardless of the route of fungus inoculation. Prior treatment did not uniformly increase the incidence of infection, however; only in the case of intranasally inoculated mice was this effect seen. Most strains appeared to be more virulent when administered intravenously, with the exception of a single strain which, under the influence of corticosteroids, repeatedly displayed greatest virulence when given intranasally. All animals that died early in the course of the disease, irrespective of route of inoculation, always had acute pulmonary lesions and usually no other organ was involved. Animals which died later or were sacrificed always had chronic lung lesions. Whether or not chronically diseased animals had additional organ involvement correlated with how the organisms were administered; intravenously inoculated animals usually had extrapulmonary as well as pulmonary lesions, but lesions of those inoculated intranasally were almost exclusively pulmonary. Corticosteroids did not alter the histologic characteristics of either the acute or the chronic type of lesion, but the lesions of treated animals were usually more extensive. Most of the survivors appeared healthy even when infection was extensive. Images PMID:4637603

Forebrain CRHR1 deficiency attenuates chronic stress-induced cognitive deficits and dendritic remodeling

PubMed Central

Wang, Xiao-Dong; Chen, Yuncai; Wolf, Miriam; Wagner, Klaus V.; Liebl, Claudia; Scharf, Sebastian H.; Harbich, Daniela; Mayer, Bianca; Wurst, Wolfgang; Holsboer, Florian; Deussing, Jan M.; Baram, Tallie Z.; Müller, Marianne B.; Schmidt, Mathias V.

2011-01-01

Chronic stress evokes profound structural and molecular changes in the hippocampus, which may underlie spatial memory deficits. Corticotropin-releasing hormone (CRH) and CRH receptor 1 (CRHR1) mediate some of the rapid effects of stress on dendritic spine morphology and modulate learning and memory, thus providing a potential molecular basis for impaired synaptic plasticity and spatial memory by repeated stress exposure. Using adult male mice with CRHR1 conditionally inactivated in the forebrain regions, we investigated the role of CRH-CRHR1 signaling in the effects of chronic social defeat stress on spatial memory, the dendritic morphology of hippocampal CA3 pyramidal neurons, and the hippocampal expression of nectin-3, a synaptic cell adhesion molecule important in synaptic remodeling. In chronically stressed wild-type mice, spatial memory was disrupted, and the complexity of apical dendrites of CA3 neurons reduced. In contrast, stressed mice with forebrain CRHR1 deficiency exhibited normal dendritic morphology of CA3 neurons and mild impairments in spatial memory. Additionally, we showed that the expression of nectin-3 in the CA3 area was regulated by chronic stress in a CRHR1-dependent fashion and associated with spatial memory and dendritic complexity. Moreover, forebrain CRHR1 deficiency prevented the down-regulation of hippocampal glucocorticoid receptor expression by chronic stress but induced increased body weight gain during persistent stress exposure. These findings underscore the important role of forebrain CRH-CRHR1 signaling in modulating chronic stress-induced cognitive, structural and molecular adaptations, with implications for stress-related psychiatric disorders. PMID:21296667

Antidepressant-like behavioral effects of impaired cannabinoid receptor type 1 signaling coincide with exaggerated corticosterone secretion in mice

PubMed Central

Steiner, Michel A; Marsicano, Giovanni; Nestler, Eric J; Holsboer, Florian; Lutz, Beat; Wotjak, Carsten T

2008-01-01

Summary Hypothalamic-pituitary-adrenocortical (HPA) axis hyperactivity is associated with major depressive disorders, and treatment with classical antidepressants ameliorates not only psychopathological symptoms, but also the dysregulation of the HPA axis. Here, we further elucidated the role of impaired cannabinoid type 1 (CB1) receptor signaling for neuroendocrine and behavioral stress coping in the mouse forced swim test (FST). We demonstrate that the genetic inactivation of CB1 is accompanied by increased plasma corticosterone levels both under basal conditions and at different time points following exposure to the FST. The latter effect could be mimicked in C57BL/6N mice by acute, subchronic and chronic administration of the selective CB1 antagonist SR141716. Further experiments confirmed the specificity of corticosterone-elevating SR141716 actions for CB1 in CB1-deficient mice. Subchronic and chronic pharmacological blockade of CB1, but not its genetic deletion, induced antidepressant-like behavioral responses in the FST that were characterized by decreased floating and/or increased struggling behavior. The antidepressant-like behavioral effects of acute desipramine treatment in the FST were absent in CB1-deficient mice, but the dampening effects of desipramine on FST stress-induced corticosterone secretion were not compromised by CB1-deficiency. However, antidepressant-like behavioral desipramine effects were intact in C57BL/6N mice pre-treated with SR141716, indicating potential developmental deficits in CB1-deficient mice. We conclude that pharmacological blockade of CB1 signaling shares antidepressant-like behavioral effects with desipramine, but reveals opposite effects on HPA axis activity. PMID:17976922

Male aromatase-knockout mice exhibit normal levels of activity, anxiety and "depressive-like" symptomatology.

PubMed

Dalla, C; Antoniou, K; Papadopoulou-Daifoti, Z; Balthazart, J; Bakker, J

2005-09-08

It is well known that estradiol derived from neural aromatization of testosterone plays a crucial role in the development of the male brain and the display of sexual behaviors in adulthood. It was recently found that male aromatase knockout mice (ArKO) deficient in estradiol due to a mutation in the aromatase gene have general deficits in coital behavior and are sexually less motivated. We wondered whether these behavioral deficits of ArKO males could be related to changes in activity, exploration, anxiety and "depressive-like" symptomatology. ArKO and wild type (WT) males were subjected to open field (OF), elevated plus maze (EPM), and forced swim tests (FST), after being exposed or not to chronic mild stress (CMS). CMS was used to evaluate the impact of chronic stressful procedures and to unveil possible differences between genotypes. There was no effect of genotype on OF, EPM and FST behavioral parameters. WT and ArKO mice exposed to CMS or not exhibited the same behavioral profile during these three types of tests. However, all CMS-exposed mice (ArKO and WT) spent less time in the center of the EPM. Additionally, floating duration measured in the FST increased between two tests in both WT and ArKO mice, though that increase was less prominent in mice previously subjected to CMS than in controls. Therefore, both ArKO and WT males displayed the same behavior and had the same response to CMS however CMS exposure slightly modified the behavior displayed by mice of both genotypes in the FST and EPM paradigms. These results show that ArKO males display normal levels of activity, exploration, anxiety and "depressive-like" symptomatology and thus their deficits in sexual behavior are specific in nature and do not result indirectly from other behavioral changes.

eRapa Restores A Normal Life Span in a FAP Mouse Model

PubMed Central

Hasty, Paul; Livi, Carolina B.; Dodds, Sherry G.; Jones, Diane; Strong, Randy; Javors, Martin; Fischer, Kathleen E.; Sloane, Lauren; Murthy, Kruthi; Hubbard, Gene; Sun, Lishi; Hurez, Vincent; Curiel, Tyler J.; Sharp, Zelton Dave

2014-01-01

Mutation of a single copy of the adenomatous polyposis coli (APC) gene results in familial adenomatous polyposis (FAP), which confers an extremely high risk for colon cancer. ApcMin/+ mice exhibit multiple intestinal neoplasia (MIN) that causes anemia and death from bleeding by 6 months. Mechanistic target of rapamycin complex 1 (mTORC1) inhibitors were shown to improve ApcMin/+ mouse survival when administered by oral gavage or added directly to the chow, but these mice still died from neoplasia well short of a natural life span. The National Institute of Aging Intervention Testing Program showed that enterically targeted rapamycin (eRapa) extended life span for wild type genetically heterogeneous mice in part by inhibiting age-associated cancer. We hypothesized that eRapa would be effective in preventing neoplasia and extend survival of ApcMin/+ mice. We show that eRapa improved survival for ApcMin/+ mice in a dose-dependent manner. Remarkably, and in contrast to previous reports, most of the ApcMin/+ mice fed 42 ppm eRapa lived beyond the median life span reported for wild type syngeneic mice. Furthermore, chronic eRapa did not cause detrimental immune effects in mouse models of cancer, infection or autoimmunity; thus, assuaging concerns that chronic rapamycin treatment suppresses immunity. Our studies suggest that a novel formulation (enteric targeting) of a well-known and widely used drug (rapamycin) can dramatically improve its efficacy in targeted settings. eRapa or other mTORC1 inhibitors could serve as effective cancer preventatives for people with FAP without suppressing the immune system, thus reducing the dependency on surgery as standard therapy. PMID:24282255

Evidence Suggesting that the Cardiomyocyte Circadian Clock Modulates Responsiveness of the Heart to Hypertrophic Stimuli in Mice

PubMed Central

Durgan, David J.; Tsai, Ju-Yun; Grenett, Maximiliano H.; Pat, Betty M.; Ratcliffe, William F.; Villegas-Montoya, Carolina; Garvey, Merissa E.; Nagendran, Jeevan; Dyck, Jason R.B.; Bray, Molly S.; Gamble, Karen L.; Gimble, Jeffrey M.; Young, Martin E.

2011-01-01

Circadian dyssynchrony of an organism (at the whole body level) with its environment, either through light/dark cycle or genetic manipulation of clock genes, augments various cardiometabolic diseases. The cardiomyocyte circadian clock has recently been shown to influence multiple myocardial processes, ranging from transcriptional regulation and energy metabolism, to contractile function. We therefore reasoned that chronic dyssychrony of the cardiomyocyte circadian clock with its environment would precipitate myocardial maladaptation to a circadian challenge (simulated shift work; SSW). To test this hypothesis, 2 and 20 month old wild-type and CCM (Cardiomyocyte Clock Mutant; a model with genetic temporal suspension of the cardiomyocyte circadian clock at the active-to-sleep phase transition) mice were subjected to chronic (16-wks) bi-weekly 12-hr phase shifts in the light/dark cycle (i.e., SSW). Assessment of adaptation/maladaptation at whole body homeostatic, gravimetric, humoral, histological, transcriptional, and cardiac contractile function levels revealed essentially identical responses between wild-type and CCM littermates. However, CCM hearts exhibit increased bi-ventricular weight, cardiomyocyte size, and molecular markers of hypertrophy (anf, mcip1) independent of aging and/or SSW. Similarly, a second genetic model of selective temporal suspension of the cardiomyocyte circadian clock (Cardiomyocyte-specific BMAL1 Knockout [CBK] mice) exhibits increased bi-ventricular weight and mcip1 expression. Wild-type mice exhibit 5-fold greater cardiac hypertrophic growth (and 6-fold greater anf mRNA induction) when challenged with the hypertrophic agonist isoproterenol at the active-to-sleep phase transition, relative to isoproterenol administration at the sleep-to-active phase transition. This diurnal variation was absent in CCM mice. Collectively, these data suggest that the cardiomyocyte circadian clock likely influences responsiveness of the heart to hypertrophic stimuli. PMID:21452915

1950 MHz Electromagnetic Fields Ameliorate Aβ Pathology in Alzheimer’s Disease Mice

PubMed Central

Jeong, Ye Ji; Kang, Ga-Young; Kwon, Jong Hwa; Choi, Hyung-Do; Pack, Jeong-Ki; Kim, Nam; Lee, Yun-Sil; Lee, Hae-June

2015-01-01

The involvement of radiofrequency electromagnetic fields (RF-EMF) in the neurodegenerative disease, especially Alzheimer’s disease (AD), has received wide consideration, however, outcomes from several researches have not shown consistency. In this study, we determined whether RF-EMF influenced AD pathology in vivo using Tg-5xFAD mice as a model of AD-like amyloid β (Aβ) pathology. The transgenic (Tg)-5xFAD and wild type (WT) mice were chronically exposed to RF-EMF for 8 months (1950 MHz, SAR 5W/kg, 2 hrs/day, 5 days/week). Notably, chronic RF-EMF exposure significantly reduced not only Aβ plaques, APP, and APP carboxyl-terminal fragments (CTFs) in whole brain including hippocampus and entorhinal cortex but also the ratio of Aβ42 and Aβ40 peptide in the hippocampus of Tg-5xFAD mice. We also found that parenchymal expression of β-amyloid precursor protein cleaving enzyme 1(BACE1) and neuroinflammation were inhibited by RF-EMF exposure in Tg-5xFAD. In addition, RF-EMF was shown to rescue memory impairment in Tg-5xFAD. Moreover, gene profiling from microarray data using hippocampus of WT and Tg-5xFAD following RF-EMF exposure revealed that 5 genes (Tshz2, Gm12695, St3gal1, Isx and Tll1), which are involved in Aβ, are significantly altered inTg-5xFAD mice, exhibiting different responses to RF-EMF in WT or Tg-5xFAD mice; RF-EMF exposure in WT mice showed similar patterns to control Tg-5xFAD mice, however, RF-EMF exposure in Tg-5xFAD mice showed opposite expression patterns. These findings indicate that chronic RF-EMF exposure directly affects Aβ pathology in AD but not in normal brain. Therefore, RF-EMF has preventive effects against AD-like pathology in advanced AD mice with a high expression of Aβ, which suggests that RF-EMF can have a beneficial influence on AD. PMID:26017559

Chronic Sleep Restriction Induces Cognitive Deficits and Cortical Beta-Amyloid Deposition in Mice via BACE1-Antisense Activation.

PubMed

Zhao, Hong-Yi; Wu, Hui-Juan; He, Jia-Lin; Zhuang, Jian-Hua; Liu, Zhen-Yu; Huang, Liu-Qing; Zhao, Zhong-Xin

2017-03-01

To clarify the correlation between chronic sleep restriction (CSR) and sporadic Alzheimer disease (AD), we determined in wild-type mice the impact of CSR, on cognitive performance, beta-amyloid (Aβ) peptides, and its feed-forward regulators regarding AD pathogenesis. Sixteen nine-month-old C57BL/6 male mice were equally divided into the CSR and control groups. CSR was achieved by application of a slowly rotating drum for 2 months. The Morris water maze test was used to assess cognitive impairment. The concentrations of Aβ peptides, amyloid precursor protein (APP) and β-secretase 1 (BACE1), and the mRNA levels of BACE1 and BACE1-antisense (BACE1-AS) were measured. Following CSR, impairments of spatial learning and memory consolidation were observed in the mice, accompanied by Aβ plaque deposition and an increased Aβ concentration in the prefrontal and temporal lobe cortex. CSR also upregulated the β-secretase-induced cleavage of APP by increasing the protein and mRNA levels of BACE1, particularly the BACE1-AS. This study shows that a CSR accelerates AD pathogenesis in wild-type mice. An upregulation of the BACE1 pathway appears to participate in both cortical Aβ plaque deposition and memory impairment caused by CSR. BACE1-AS is likely activated to initiate a cascade of events that lead to AD pathogenesis. Our study provides, therefore, a molecular mechanism that links CSR to sporadic AD. © 2017 John Wiley & Sons Ltd.

Commensal microbiota is hepatoprotective and prevents liver fibrosis in mice

PubMed Central

Mazagova, Magdalena; Wang, Lirui; Anfora, Andrew T.; Wissmueller, Max; Lesley, Scott A.; Miyamoto, Yukiko; Eckmann, Lars; Dhungana, Suraj; Pathmasiri, Wimal; Sumner, Susan; Westwater, Caroline; Brenner, David A.; Schnabl, Bernd

2015-01-01

Translocation of bacteria and their products across the intestinal barrier is common in patients with liver disease, and there is evidence that experimental liver fibrosis depends on bacterial translocation. The purpose of our study was to investigate liver fibrosis in conventional and germ-free (GF) C57BL/6 mice. Chronic liver injury was induced by administration of thioacetamide (TAA) in the drinking water for 21 wk or by repeated intraperitoneal injections of carbon tetrachloride (CCl4). Increased liver fibrosis was observed in GF mice compared with conventional mice. Hepatocytes showed more toxin-induced oxidative stress and cell death. This was accompanied by increased activation of hepatic stellate cells, but hepatic mediators of inflammation were not significantly different. Similarly, a genetic model using Myd88/Trif-deficient mice, which lack downstream innate immunity signaling, had more severe fibrosis than wild-type mice. Isolated Myd88/Trif-deficient hepatocytes were more susceptible to toxin-induced cell death in culture. In conclusion, the commensal microbiota prevents fibrosis upon chronic liver injury in mice. This is the first study describing a beneficial role of the commensal microbiota in maintaining liver homeostasis and preventing liver fibrosis.—Mazagova, M., Wang, L., Anfora, A. T., Wissmueller, M., Lesley, S. A., Miyamoto, Y., Eckmann, L., Dhungana, S., Pathmasiri, W., Sumner, S., Westwater, C., Brenner, D. A., Schnabl, B. Commensal microbiota is hepatoprotective and prevents liver fibrosis in mice. PMID:25466902

Losartan Decreases Cardiac Muscle Fibrosis and Improves Cardiac Function in Dystrophin-Deficient Mdx Mice

PubMed Central

Spurney, Christopher F.; Sali, Arpana; Guerron, Alfredo D.; Iantorno, Micaela; Yu, Qing; Gordish-Dressman, Heather; Rayavarapu, Sree; van der Meulen, Jack; Hoffman, Eric P.; Nagaraju, Kanneboyina

2014-01-01

Recent studies showed that chronic administration of losartan, an angiotensin II type I receptor antagonist, improved skeletal muscle function in dystrophin-deficient mdx mice. In this study, C57BL/10ScSn-Dmdmdx/J female mice were either untreated or treated with losartan (n = 15) in the drinking water at a dose of 600 mg/L over a 6-month period. Cardiac function was assessed via in vivo high frequency echocardiography and skeletal muscle function was assessed using grip strength testing, Digiscan monitoring, Rotarod timing, and in vitro force testing. Fibrosis was assessed using picrosirius red staining and Image J analysis. Gene expression was evaluated using real-time polymerized chain reaction (RT-PCR). Percentage shortening fraction was significantly decreased in untreated (26.9% ± 3.5%) mice compared to losartan-treated (32.2% ± 4.2%; P < .01) mice. Systolic blood pressure was significantly reduced in losartan-treated mice (56 ± 6 vs 69 ± 7 mm Hg; P < .0005). Percentage cardiac fibrosis was significantly reduced in losartan-treated hearts (P < .05) along with diaphragm (P < .01), extensor digitorum longus (P < .05), and gastrocnemius (P < .05) muscles compared to untreated mdx mice. There were no significant differences in skeletal muscle function between treated and untreated groups. Chronic treatment with losartan decreases cardiac and skeletal muscle fibrosis and improves cardiac systolic function in dystrophin-deficient mdx mice. PMID:21304057

Cell type-specific in vivo expression of genes encoding signalling molecules in the brain in response to chronic mild stress and chronic treatment with fluoxetine.

PubMed

Dong, Lu; Li, Baoman; Verkhratsky, Alexei; Peng, Liang

2015-08-01

Previously, we reported that chronic treatment with fluoxetine increased gene expression of 5-hydroxytryptamine receptor 2B (5-HT2BR), cytosolic phospholipase 2α (cPLA2α), glutamate receptor, ionotropic kainate 2 (GluK2) and adenosine deaminase acting on RNA 2 (ADAR2), in cultured astrocytes and astrocytes freshly isolated from transgenic mice tagged with an astrocyte-specific marker. In contrast, neurones isolated from transgenic mice tagged with a neurone-specific marker and exposed to fluoxetine showed an increase in gene expression of glutamate receptor, ionotropic kainate 4 (GluK4) and 5-hydroxytryptamine receptor 2C (5-HT2CR). In a mouse model of anhedonia, the downregulation of 5-HT2BR, cPLA2α, ADAR2 and GluK4 but not GluK2 and 5-HT2CR was detected. To investigate the effects of chronic mild stress (CMS) and/or fluoxetine treatment on gene expression of 5-HT2BR, 5-HT2CR, cPLA2α, ADAR2, GluK2 and GluK4 specifically in astrocytes and neurones. Transgenic mice tagged with either astrocyte- or neurone-specific markers were exposed to the CMS. Real-time PCR was applied to determine expression of messenger RNA (mRNA). We found that (i) mRNAs of the 5-HT2BR and cPLA2α in astrocytes and GluK4 in neurones were significantly reduced in mice that became anhedonic; the mRNA levels were restored by fluoxetine treatment; (ii) ADAR2 in astrocytes was decreased by the CMS but showed no response to fluoxetine in anhedonic animals; (iii) neither GluK2 expression in astrocytes nor 5-HT2CR expression in neurones were affected in anhedonic animals, although expression of 5-HT2CR mRNA was upregulated by fluoxetine. Our results indicate that the effects of chronic treatment with fluoxetine are not only dependent on the cell type studied but also on the development of anhedonia. This suggests that fluoxetine may affect major depression (MD) patients and healthy people in a different manner.

Impaired Leptomeningeal Collateral Flow Contributes to the Poor Outcome following Experimental Stroke in the Type 2 Diabetic Mice

PubMed Central

Akamatsu, Yosuke; Nishijima, Yasuo; Lee, Chih Cheng; Yang, Shih Yen; Shi, Lei; An, Lin; Wang, Ruikang K.; Tominaga, Teiji

2015-01-01

Collateral status is an independent predictor of stroke outcome. However, the spatiotemporal manner in which collateral flow maintains cerebral perfusion during cerebral ischemia is poorly understood. Diabetes exacerbates ischemic brain damage, although the impact of diabetes on collateral dynamics remains to be established. Using Doppler optical coherent tomography, a robust recruitment of leptomeningeal collateral flow was detected immediately after middle cerebral artery (MCA) occlusion in C57BL/6 mice, and it continued to grow over the course of 1 week. In contrast, an impairment of collateral recruitment was evident in the Type 2 diabetic db/db mice, which coincided with a worse stroke outcome compared with their normoglycemic counterpart db/+, despite their equally well-collateralized leptomeningeal anastomoses. Similar to the wild-type mice, both db/+ and db/db mice underwent collateral growth 7 d after MCA stroke, although db/db mice still exhibited significantly reduced retrograde flow into the MCA territory chronically. Acutely induced hyperglycemia in the db/+ mice did not impair collateral flow after stroke, suggesting that the state of hyperglycemia alone was not sufficient to impact collateral flow. Human albumin was efficacious in improving collateral flow and outcome after stroke in the db/db mice, enabling perfusion to proximal MCA territory that was usually not reached by retrograde flow from anterior cerebral artery without treatment. Our results suggest that the impaired collateral status contributes to the exacerbated ischemic injury in mice with Type 2 diabetes, and modulation of collateral flow has beneficial effects on stroke outcome among these subjects. PMID:25740515

miR-155 deficiency protects mice from experimental colitis by reducing T helper type 1/type 17 responses

PubMed Central

Singh, Udai P; Murphy, Angela E; Enos, Reilly T; Shamran, Haidar A; Singh, Narendra P; Guan, Honbing; Hegde, Venkatesh L; Fan, Daping; Price, Robert L; Taub, Dennis D; Mishra, Manoj K; Nagarkatti, Mitzi; Nagarkatti, Prakash S

2014-01-01

Inflammatory bowel disease (IBD), a chronic intestinal inflammatory condition that affects millions of people worldwide, results in high morbidity and exorbitant health-care costs. The critical features of both innate and adaptive immunity are to control inflammation and dysfunction in this equilibrium is believed to be the reason for the development of IBD. miR-155, a microRNA, is up-regulated in various inflammatory disease states, including IBD, and is a positive regulator of T-cell responses. To date, no reports have defined a function for miR-155 with regard to cellular responses in IBD. Using an acute experimental colitis model, we found that miR-155−/− mice, as compared to wild-type control mice, have decreased clinical scores, a reversal of colitis-associated pathogenesis, and reduced systemic and mucosal inflammatory cytokines. The increased frequency of CD4+ lymphocytes in the spleen and lamina propria with dextran sodium sulphate induction was decreased in miR-155−/− mice. Similarly, miR-155 deficiency abrogated the increased numbers of interferon-γ expressing CD4+ T cells typically observed in wild-type mice in this model. The frequency of systemic and mucosal T helper type 17-, CCR9-expressing CD4+ T cells was also reduced in miR-155−/− mice compared with control mice. These findings strongly support a role for miR-155 in facilitating pro-inflammatory cellular responses in this model of IBD. Loss of miR-155 also results in decreases in T helper type 1/type 17, CD11b+, and CD11c+ cells, which correlated with reduced clinical scores and severity of disease. miR-155 may serve as a potential therapeutic target for the treatment of IBD. PMID:24891206

Chronic Neuropathic Pain in Mice Reduces μ-Opioid Receptor-Mediated G-protein Activity in the Thalamus

PubMed Central

Hoot, Michelle R.; Sim-Selley, Laura J.; Selley, Dana E.; Scoggins, Krista L.; Dewey, William L.

2011-01-01

Neuropathic pain is a debilitating condition that is often difficult to treat using conventional pharmacological interventions and the exact mechanisms involved in the establishment and maintenance of this type of chronic pain have yet to be fully elucidated. The present studies examined the effect of chronic nerve injury on μ-opioid receptors and receptor-mediated G-protein activity within the supraspinal brain regions involved in pain processing of mice. Chronic constriction injury (CCI) reduced paw withdrawal latency, which was maximal at 10 days post-injury. [d-Ala2,(N-Me)Phe4, Gly5-OH] enkephalin (DAMGO)-stimulated [35S]GTPγS binding was then conducted at this time point in membranes prepared from the rostral ACC (rACC), thalamus and periaqueductal grey (PAG) of CCI and sham-operated mice. Results showed reduced DAMGO-stimulated [35S]GTPγS binding in the thalamus and PAG of CCI mice, with no change in the rACC. In thalamus, this reduction was due to decreased maximal stimulation by DAMGO, with no difference in EC50 values. In PAG, however, DAMGO Emax values did not significantly differ between groups, possibly due to the small magnitude of the main effect. [3H]Naloxone binding in membranes of the thalamus showed no significant differences in Bmax values between CCI and sham-operated mice, indicating that the difference in G-protein activation did not result from differences in μ-opioid receptor levels. These results suggest that CCI induced a region-specific adaptation of μ-opioid receptor-mediated G-protein activity, with apparent desensitization of the μ-opioid receptor in the thalamus and PAG and could have implications for treatment of neuropathic pain. PMID:21762883

Attenuated behavioural responses to acute and chronic cocaine in GASP-1-deficient mice.

PubMed

Boeuf, Julien; Trigo, José Manuel; Moreau, Pierre-Henri; Lecourtier, Lucas; Vogel, Elise; Cassel, Jean-Cristophe; Mathis, Chantal; Klosen, Paul; Maldonado, Rafael; Simonin, Frédéric

2009-09-01

G protein-coupled receptor (GPCR) associated sorting protein 1 (GASP-1) interacts with GPCRs and is implicated in their postendocytic sorting. Recently, GASP-1 has been shown to regulate dopamine (D(2)) and cannabinoid (CB1) receptor signalling, suggesting that preventing GASP-1 interaction with GPCRs might provide a means to limit the decrease in receptor signalling upon sustained agonist treatment. In order to test this hypothesis, we have generated and behaviourally characterized GASP-1 knockout (KO) mice and have examined the consequences of the absence of GASP-1 on chronic cocaine treatments. GASP-1 KO and wild-type (WT) mice were tested for sensitization to the locomotor effects of cocaine. Additional mice were trained to acquire intravenous self-administration of cocaine on a fixed ratio 1 schedule of reinforcement, and the motivational value of cocaine was then assessed using a progressive ratio schedule of reinforcement. The dopamine and muscarinic receptor densities were quantitatively evaluated in the striatum of WT and KO mice tested for sensitization and self-administration. Acute and sensitized cocaine-locomotor effects were attenuated in KO mice. A decrease in the percentage of animals that acquired cocaine self-administration was also observed in GASP-1-deficient mice, which was associated with pronounced down-regulation of dopamine and muscarinic receptors in the striatum. These data indicate that GASP-1 participates in acute and chronic behavioural responses induced by cocaine and are in agreement with a role of GASP-1 in postendocytic sorting of GPCRs. However, in contrast to previous studies, our data suggest that upon sustained receptor stimulation GASP-1 stimulates recycling rather than receptor degradation.

Endocannabinoid dysregulation in cognitive and stress-related brain regions in the Nrg1 mouse model of schizophrenia.

PubMed

Clarke, David J; Stuart, Jordyn; McGregor, Iain S; Arnold, Jonathon C

2017-01-04

The endocannabinoid system is dysregulated in schizophrenia. Mice with heterozygous deletion of neuregulin 1 (Nrg1 HET mice) provide a well-characterised animal model of schizophrenia, and display enhanced sensitivity to stress and cannabinoids during adolescence. However, no study has yet determined whether these mice have altered brain endocannabinoid concentrations. Nrg1 application to hippocampal slices decreased 2-arachidonoylglycerol (2-AG) signalling and disrupted long-term depression, a form of synaptic plasticity critical to spatial learning. Therefore we specifically aimed to examine whether Nrg1 HET mice exhibit increased 2-AG concentrations and disruption of spatial learning. As chronic stress influences brain endocannabinoids, we also sought to examine whether Nrg1 deficiency moderates adolescent stress-induced alterations in brain endocannabinoids. Adolescent Nrg1 HET and wild-type (WT) mice were submitted to chronic restraint stress and brain endocannabinoid concentrations were analysed. A separate cohort of WT and Nrg1 HET mice was also assessed for spatial learning performance in the Morris Water Maze. Partial genetic deletion of Nrg1 increased anandamide concentrations in the amygdala and decreased 2-AG concentrations in the hypothalamus. Further, Nrg1 HET mice exhibited increased 2-AG concentrations in the hippocampus and impaired spatial learning performance. Chronic adolescent stress increased anandamide concentrations in the amygdala, however, Nrg1 disruption did not influence this stress-induced change. These results demonstrate for the first time in vivo interplay between Nrg1 and endocannabinoids in the brain. Our results demonstrate that aberrant Nrg1 and endocannabinoid signalling may cooperate in the hippocampus to impair cognition, and that Nrg1 deficiency alters endocannabinoid signalling in brain stress circuitry. Copyright © 2016 Elsevier Inc. All rights reserved.

Protein quality control in protection against systolic overload cardiomyopathy: the long term role of small heat shock proteins

PubMed Central

Kumarapeli, Asangi R K; Horak, Kathleen; Wang, Xuejun

2010-01-01

Molecular chaperones represent the first line of defense of intracellular protein quality control. As a major constituent of molecular chaperones, heat shock proteins (HSP) are known to confer cardiomyocyte short-term protection against various insults and injuries. Previously, we reported that the small HSP αB-crystallin (CryAB) attenuates cardiac hypertrophic response in mice subjected to 2 weeks of severe pressure overload. However, the long-term role of small HSPs in cardiac hypertrophy and failure has rarely been studied. The present study investigates the cardiac responses to chronic severe pressure overload in CryAB/HSPB2 germ line ablated (KO) and cardiac-specific CryAB overexpressingtransgenic (TG) mice. Pressure overload was induced by transverse aortic constriction in KO, TG, and non-transgenic wild type (NTG) control mice and 10 weeks later molecular, cellular, and whole organ level hypertrophic responses were analyzed. As we previously described, CryAB/HSPB2 KO mice showed abnormal baseline cardiac physiology that worsened into a restrictive cardiomyopathic phenotype with aging. Severe pressure overload in these mice led to rapid deterioration of heart function and development of congestive cardiac failure. Contrary to their short term protective phenotype, CryAB TG mice showed no significant effects on cardiac hypertrophic responses and very modest improvement of hemodynamics during chronic systolic overload. These findings indicate that small HSPs CryAB and/or HSPB2 are essential to maintain cardiac structure and function but overex-pression of CryAB is not sufficient to confer a sustained protection against chronic systolic overload. PMID:20733949

Hippocampal structure and function are maintained despite severe innate peripheral inflammation.

PubMed

Süß, Patrick; Kalinichenko, Liubov; Baum, Wolfgang; Reichel, Martin; Kornhuber, Johannes; Loskarn, Sandra; Ettle, Benjamin; Distler, Jörg H W; Schett, Georg; Winkler, Jürgen; Müller, Christian P; Schlachetzki, Johannes C M

2015-10-01

Chronic peripheral inflammation mediated by cytokines such as TNFα, IL-1β, and IL-6 is associated with psychiatric disorders like depression and anxiety. However, it remains elusive which distinct type of peripheral inflammation triggers neuroinflammation and affects hippocampal plasticity resulting in depressive-like behavior. We hypothesized that chronic peripheral inflammation in the human TNF-α transgenic (TNFtg) mouse model of rheumatoid arthritis spreads into the central nervous system and induces depressive state manifested in specific behavioral pattern and impaired adult hippocampal neurogenesis. TNFtg mice showed severe erosive arthritis with increased IL-1β and IL-6 expression in tarsal joints with highly elevated human TNF-α levels in the serum. Intriguingly, IL-1β and IL-6 mRNA levels were not altered in the hippocampus of TNFtg mice. In contrast to the pronounced monocytosis in joints and spleen of TNFtg mice, signs of hippocampal microgliosis or astrocytosis were lacking. Furthermore, locomotion was impaired, but there was no locomotion-independent depressive behavior in TNFtg mice. Proliferation and maturation of hippocampal neural precursor cells as well as survival of newly generated neurons were preserved in the dentate gyrus of TNFtg mice despite reduced motor activity and peripheral inflammatory signature. We conclude that peripheral inflammation in TNFtg mice is mediated by chronic activation of the innate immune system. However, severe peripheral inflammation, though impairing locomotor activity, does not elicit depressive-like behavior. These structural and functional findings indicate the maintenance of hippocampal immunity, cellular plasticity, and behavior despite peripheral innate inflammation. Copyright © 2015 Elsevier Inc. All rights reserved.

Protein quality control in protection against systolic overload cardiomyopathy: the long term role of small heat shock proteins.

PubMed

Kumarapeli, Asangi R K; Horak, Kathleen; Wang, Xuejun

2010-07-21

Molecular chaperones represent the first line of defense of intracellular protein quality control. As a major constituent of molecular chaperones, heat shock proteins (HSP) are known to confer cardiomyocyte short-term protection against various insults and injuries. Previously, we reported that the small HSP alphaB-crystallin (CryAB) attenuates cardiac hypertrophic response in mice subjected to 2 weeks of severe pressure overload. However, the long-term role of small HSPs in cardiac hypertrophy and failure has rarely been studied. The present study investigates the cardiac responses to chronic severe pressure overload in CryAB/HSPB2 germ line ablated (KO) and cardiac-specific CryAB overexpressingtransgenic (TG) mice. Pressure overload was induced by transverse aortic constriction in KO, TG, and non-transgenic wild type (NTG) control mice and 10 weeks later molecular, cellular, and whole organ level hypertrophic responses were analyzed. As we previously described, CryAB/HSPB2 KO mice showed abnormal baseline cardiac physiology that worsened into a restrictive cardiomyopathic phenotype with aging. Severe pressure overload in these mice led to rapid deterioration of heart function and development of congestive cardiac failure. Contrary to their short term protective phenotype, CryAB TG mice showed no significant effects on cardiac hypertrophic responses and very modest improvement of hemodynamics during chronic systolic overload. These findings indicate that small HSPs CryAB and/or HSPB2 are essential to maintain cardiac structure and function but overex-pression of CryAB is not sufficient to confer a sustained protection against chronic systolic overload.

Chronic Exposure to Rifaximin Causes Hepatic Steatosis in Pregnane X Receptor-Humanized Mice

PubMed Central

Gonzalez, Frank, J.

2012-01-01

Rifaximin, a nonsystemic antibiotic that exhibits low gastrointestinal absorption, is a potent agonist of human pregnane X receptor (PXR), which contributes to its therapeutic efficacy in inflammatory bowel disease. To investigate the effects of long-term administration of rifaximin on the liver, PXR-humanized mice were administered rifaximin for 6 months; wild-type and Pxr-null mice were treated in parallel as controls. Histological analysis revealed time-dependent intense hepatocellular fatty degeneration and increased hepatic triglycerides in PXR-humanized mice and not in wild-type and Pxr-null mice. After long-term treatment, PXR target genes were induced in small intestine and liver, with significant up-regulation in the expression of hepatic genes related to triglyceride synthesis and lipid accumulation. However, no significant hepatic accumulation of rifaximin was found, even after 6 months of treatment, in PXR-humanized mice. Genes in the small intestine that are involved in the uptake of fatty acids and triglycerides were induced along with increased triglyceride accumulation in intestinal epithelial cells of PXR-humanized mice; this was not observed in wild-type and Pxr-null mice. These findings suggest that long-term administration of rifaximin could lead to PXR-dependent hepatocellular fatty degeneration as a result of activation of genes involved in lipid uptake, thus indicating a potential adverse effect of rifaximin on liver function after long-term exposure. PMID:22790967

Dietary restriction but not angiotensin II type 1 receptor blockade improves DNA damage-related vasodilator dysfunction in rapidly aging Ercc1Δ/- mice.

PubMed

Wu, Haiyan; van Thiel, Bibi S; Bautista-Niño, Paula K; Reiling, Erwin; Durik, Matej; Leijten, Frank P J; Ridwan, Yanto; Brandt, Renata M C; van Steeg, Harry; Dollé, Martijn E T; Vermeij, Wilbert P; Hoeijmakers, Jan H J; Essers, Jeroen; van der Pluijm, Ingrid; Danser, A H Jan; Roks, Anton J M

2017-08-01

DNA damage is an important contributor to endothelial dysfunction and age-related vascular disease. Recently, we demonstrated in a DNA repair-deficient, prematurely aging mouse model ( Ercc1 Δ/- mice) that dietary restriction (DR) strongly increases life- and health span, including ameliorating endothelial dysfunction, by preserving genomic integrity. In this mouse mutant displaying prominent accelerated, age-dependent endothelial dysfunction we investigated the signaling pathways involved in improved endothelium-mediated vasodilation by DR, and explore the potential role of the renin-angiotensin system (RAS). Ercc1 Δ/- mice showed increased blood pressure and decreased aortic relaxations to acetylcholine (ACh) in organ bath experiments. Nitric oxide (NO) signaling and phospho-Ser 1177 -eNOS were compromised in Ercc1 Δ / - DR improved relaxations by increasing prostaglandin-mediated responses. Increase of cyclo-oxygenase 2 and decrease of phosphodiesterase 4B were identified as potential mechanisms. DR also prevented loss of NO signaling in vascular smooth muscle cells and normalized angiotensin II (Ang II) vasoconstrictions, which were increased in Ercc1 Δ/- mice. Ercc1 Δ/ - mutants showed a loss of Ang II type 2 receptor-mediated counter-regulation of Ang II type 1 receptor-induced vasoconstrictions. Chronic losartan treatment effectively decreased blood pressure, but did not improve endothelium-dependent relaxations. This result might relate to the aging-associated loss of treatment efficacy of RAS blockade with respect to endothelial function improvement. In summary, DR effectively prevents endothelium-dependent vasodilator dysfunction by augmenting prostaglandin-mediated responses, whereas chronic Ang II type 1 receptor blockade is ineffective. © 2017 The Author(s). Published by Portland Press Limited on behalf of the Biochemical Society.

3xTgAD mice exhibit altered behavior and elevated Aβ after chronic mild social stress

PubMed Central

Rothman, Sarah M.; Herdener, Nathan; Camandola, Simonetta; Texel, Sarah J.; Mughal, Mohamed R.; Cong, Wei-Na; Martin, Bronwen; Mattson, Mark P

2014-01-01

Chronic stress may be a risk factor for developing Alzheimer’s disease (AD), but most studies of the effects of stress in models of AD utilize acute adverse stressors of questionable clinical relevance. The goal of this work was to determine how chronic psychosocial stress affects behavioral and pathological outcomes in an animal model of AD, and to elucidate underlying mechanisms. A triple-transgenic mouse model of AD (3xTgAD mice) and nontransgenic control mice were used to test for an affect of chronic mild social stress on blood glucose, plasma glucocorticoids, plasma insulin, anxiety and hippocampal Aβ, ptau and BDNF levels. Despite the fact that both control and 3xTgAD mice experienced rises in corticosterone during episodes of mild social stress, at the end of the 6 week stress period 3xTgAD mice displayed increased anxiety, elevated levels of Aβ oligomers and intraneuronal Aβ, and decreased BDNF levels, whereas control mice did not. Findings suggest 3xTgAD mice are more vulnerable than control mice to chronic psychosocial stress, and that such chronic stress exacerbates Aβ accumulation and impairs neurotrophic signaling. PMID:21855175

T-cell-dependent control of acute Giardia lamblia infections in mice.

PubMed

Singer, S M; Nash, T E

2000-01-01

We have studied immune mechanisms responsible for control of acute Giardia lamblia and Giardia muris infections in adult mice. Association of chronic G. lamblia infection with hypogammaglobulinemia and experimental infections of mice with G. muris have led to the hypothesis that antibodies are required to control these infections. We directly tested this hypothesis by infecting B-cell-deficient mice with either G. lamblia or G. muris. Both wild-type mice and B-cell-deficient mice eliminated the vast majority of parasites between 1 and 2 weeks postinfection with G. lamblia. G. muris was also eliminated in both wild-type and B-cell-deficient mice. In contrast, T-cell-deficient and scid mice failed to control G. lamblia infections, as has been shown previously for G. muris. Treatment of wild-type or B-cell-deficient mice with antibodies to CD4 also prevented elimination of G. lamblia, confirming a role for T cells in controlling infections. By infecting mice deficient in either alphabeta- or gammadelta-T-cell receptor (TCR)-expressing T cells, we show that the alphabeta-TCR-expressing T cells are required to control parasites but that the gammadelta-TCR-expressing T cells are not. Finally, infections in mice deficient in production of gamma interferon or interleukin 4 (IL-4) and mice deficient in responding to IL-4 and IL-13 revealed that neither the Th1 nor the Th2 subset is absolutely required for protection from G. lamblia. We conclude that a T-cell-dependent mechanism is essential for controlling acute Giardia infections and that this mechanism is independent of antibody and B cells.

Effects of Active Mastication on Chronic Stress-Induced Bone Loss in Mice

PubMed Central

Azuma, Kagaku; Furuzawa, Manabu; Fujiwara, Shu; Yamada, Kumiko; Kubo, Kin-ya

2015-01-01

Chronic psychologic stress increases corticosterone levels, which decreases bone density. Active mastication or chewing attenuates stress-induced increases in corticosterone. We evaluated whether active mastication attenuates chronic stress-induced bone loss in mice. Male C57BL/6 (B6) mice were randomly divided into control, stress, and stress/chewing groups. Stress was induced by placing mice in a ventilated restraint tube (60 min, 2x/day, 4 weeks). The stress/chewing group was given a wooden stick to chew during the experimental period. Quantitative micro-computed tomography, histologic analysis, and biochemical markers were used to evaluate the bone response. The stress/chewing group exhibited significantly attenuated stress-induced increases in serum corticosterone levels, suppressed bone formation, enhanced bone resorption, and decreased trabecular bone mass in the vertebrae and distal femurs, compared with mice in the stress group. Active mastication during exposure to chronic stress alleviated chronic stress-induced bone density loss in B6 mice. Active mastication during chronic psychologic stress may thus be an effective strategy to prevent and/or treat chronic stress-related osteopenia. PMID:26664256

Effects of Active Mastication on Chronic Stress-Induced Bone Loss in Mice.

PubMed

Azuma, Kagaku; Furuzawa, Manabu; Fujiwara, Shu; Yamada, Kumiko; Kubo, Kin-ya

2015-01-01

Chronic psychologic stress increases corticosterone levels, which decreases bone density. Active mastication or chewing attenuates stress-induced increases in corticosterone. We evaluated whether active mastication attenuates chronic stress-induced bone loss in mice. Male C57BL/6 (B6) mice were randomly divided into control, stress, and stress/chewing groups. Stress was induced by placing mice in a ventilated restraint tube (60 min, 2x/day, 4 weeks). The stress/chewing group was given a wooden stick to chew during the experimental period. Quantitative micro-computed tomography, histologic analysis, and biochemical markers were used to evaluate the bone response. The stress/chewing group exhibited significantly attenuated stress-induced increases in serum corticosterone levels, suppressed bone formation, enhanced bone resorption, and decreased trabecular bone mass in the vertebrae and distal femurs, compared with mice in the stress group. Active mastication during exposure to chronic stress alleviated chronic stress-induced bone density loss in B6 mice. Active mastication during chronic psychologic stress may thus be an effective strategy to prevent and/or treat chronic stress-related osteopenia.

Loss of Cdh1 and Trp53 in the uterus induces chronic inflammation with modification of tumor microenvironment.

PubMed

Stodden, G R; Lindberg, M E; King, M L; Paquet, M; MacLean, J A; Mann, J L; DeMayo, F J; Lydon, J P; Hayashi, K

2015-05-07

Type II endometrial carcinomas (ECs) are estrogen independent, poorly differentiated tumors that behave in an aggressive manner. As TP53 mutation and CDH1 inactivation occur in 80% of human endometrial type II carcinomas, we hypothesized that mouse uteri lacking both Trp53 and Cdh1 would exhibit a phenotype indicative of neoplastic transformation. Mice with conditional ablation of Cdh1 and Trp53 (Cdh1(d/d)Trp53(d/d)) clearly demonstrate architectural features characteristic of type II ECs, including focal areas of papillary differentiation, protruding cytoplasm into the lumen (hobnailing) and severe nuclear atypia at 6 months of age. Further, Cdh1(d/d)Trp53(d/d) tumors in 12-month-old mice were highly aggressive, and metastasized to nearby and distant organs within the peritoneal cavity, such as abdominal lymph nodes, mesentery and peri-intestinal adipose tissues, demonstrating that tumorigenesis in this model proceeds through the universally recognized morphological intermediates associated with type II endometrial neoplasia. We also observed abundant cell proliferation and complex angiogenesis in the uteri of Cdh1(d/d)Trp53(d/d) mice. Our microarray analysis found that most of the genes differentially regulated in the uteri of Cdh1(d/d)Trp53(d/d) mice were involved in inflammatory responses. CD163 and Arg1, markers for tumor-associated macrophages, were also detected and increased in the uteri of Cdh1(d/d)Trp53(d/d) mice, suggesting that an inflammatory tumor microenvironment with immune cell recruitment is augmenting tumor development in Cdh1(d/d)Trp53(d/d) uteri. Further, inflammatory mediators secreted from CDH1-negative, TP53 mutant endometrial cancer cells induced normal macrophages to express inflammatory-related genes through activation of nuclear factor-κB signaling. These results indicate that absence of CDH1 and TP53 in endometrial cells initiates chronic inflammation, promotes tumor microenvironment development following the recruitment of macrophages and promotes aggressive ECs.

Loss of Cdh1 and Trp53 in the uterus induces chronic inflammation with modification of tumor microenvironment

PubMed Central

Stodden, Genna R.; Lindberg, Mallory E.; King, Mandy L.; Paquet, Marilène; MacLean, James A.; Mann, Jordan L.; DeMayo, Francesco J.; Lydon, John P.; Hayashi, Kanako

2015-01-01

Type II endometrial carcinomas are estrogen independent, poorly differentiated tumors that behave in an aggressive manner. Since TP53 mutation and CDH1 inactivation occur in 80% of human endometrial type II carcinomas, we hypothesized that mouse uteri lacking both Trp53 and Cdh1 would exhibit a phenotype indicative of neoplastic transformation. Mice with conditional ablation of Cdh1 and Trp53 (Cdh1d/dTrp53d/d) clearly demonstrate architectural features characteristic of type II endometrial carcinomas, including focal areas of papillary differentiation, protruding cytoplasm into the lumen (hobnailing) and severe nuclear atypia at 6-mo of age. Further, Cdh1d/dTrp53d/d tumors in 12-mo old mice were highly aggressive, and metastasized to nearby and distant organs within the peritoneal cavity, such as abdominal lymph nodes, mesentery and peri-intestinal adipose tissues, demonstrating that tumorigenesis in this model proceeds through the universally recognized morphologic intermediates associated with type II endometrial neoplasia. We also observed abundant cell proliferation and complex angiogenesis in the uteri of Cdh1d/dTrp53d/d mice. Our microarray analysis found that most of the genes differentially regulated in the uteri of Cdh1d/dTrp53d/d mice were involved in inflammatory responses. CD163 and Arg1, markers for tumor-associated macrophages, were also detected and increased in the uteri of Cdh1d/dTrp53d/d mice, suggesting that an inflammatory tumor microenvironment with immune cell recruitment is augmenting tumor development in Cdh1d/dTrp53d/d uteri. Further, inflammatory mediators secreted from CDH1 negative, TP53 mutant endometrial cancer cells induced normal macrophages to express inflammatory related genes through activation of NFκB signaling. These results indicate that absence of CDH1 and TP53 in endometrial cells initiates chronic inflammation, promotes tumor microenvironment development following the recruitment of macrophages, and promotes aggressive endometrial carcinomas. PMID:24998851

Toxoplasma gondii as a possible causative pathogen of type-1 diabetes mellitus: Evidence from case-control and experimental studies.

PubMed

Nassief Beshay, Engy Victor; El-Refai, Samar A; Helwa, Mohamed A; Atia, Amany Fawzy; Dawoud, Marwa Mohammed

2018-05-01

Toxoplasma gondii is the causative parasite of an important worldwide disease. This obligate intracellular parasite can infect and replicate inside any nucleated cells including those of pancreas. Insulin is a hormone secreted by the pancreas and is responsible for controlling blood glucose concentration. Deficiency of insulin production accounts for the occurrence of type-1 diabetes mellitus (T1D). Thus, theoretically, toxoplasmosis could play a possible role in the development of T1D. However, the studies on this theory are still insufficient; therefore, this work was designed. Interestingly, in the case-control study, seropositivity of anti-Toxoplasma IgG was significantly higher among T1D (86.37%) in comparison with T2D (66.67%) and the control group (60%). Moreover, the odd ratio of chronic toxoplasmosis was 4.2 folds higher among T1D patients than among controls. The experimental study included acute and chronic Me49 T. gondii infected mice groups in addition to a control group. Pathological examination revealed the presence of T. gondii zoites adjacent to the islets of Langerhans and in pancreatic parenchyma of acutely infected mice. With chronic infection, there was a significant reduction of islets number and sizes in association with grade-1 insulitis. Additionally, the immunohistochemical study showed significant infiltration of the islets of chronically infected mice by CD8 + and CD45 + immune cells. In contrary to the control group, the islets of the chronic group showed significantly higher expression of the apoptotic marker caspase-3 and a significantly lower expression of the proliferation marker Ki69. Finally, a significant reduction of insulin expression in the islets of chronic infection group was detected in association with a significant increase in serum glucose concentrations; however, the establishment of diabetes did not occur throughout this work. Thus, this study presents an evidence for the probable role of chronic toxoplasmosis in the development of T1D which should be considered in further studies. Copyright © 2018 Elsevier Inc. All rights reserved.

Altered brain concentrations of citalopram and escitalopram in P-glycoprotein deficient mice after acute and chronic treatment.

PubMed

Karlsson, Louise; Carlsson, Björn; Hiemke, Christoph; Ahlner, Johan; Bengtsson, Finn; Schmitt, Ulrich; Kugelberg, Fredrik C

2013-11-01

According to both in vitro and in vivo data P-glycoprotein (P-gp) may restrict the uptake of several antidepressants into the brain, thus contributing to the poor success rate of current antidepressant therapies. The therapeutic activity of citalopram resides in the S-enantiomer, whereas the R-enantiomer is practically devoid of serotonin reuptake potency. To date, no in vivo data are available that address whether the enantiomers of citalopram and its metabolites are substrates of P-gp. P-gp knockout (abcb1ab (-/-)) and wild-type (abcb1ab (+/+)) mice underwent acute (single-dose) and chronic (two daily doses for 10 days) treatment with citalopram (10mg/kg) or escitalopram (5mg/kg) Serum and brain samples were collected 1-6h after the first or last i.p. injection for subsequent drug analysis by an enantioselective HPLC method. In brain, 3-fold higher concentrations of S- and R-citalopram, and its metabolites, were found in abcb1ab (-/-) mice than in abcb1ab (+/+) mice after both acute and chronic citalopram treatments. After escitalopram treatment, the S-citalopram brain concentration was 3-5 times higher in the knockout mice than in controls. The results provide novel evidence that the enantiomers of citalopram are substrates of P-gp. Possible clinical and toxicological implications of this finding need to be further elucidated. Copyright © 2013 Elsevier B.V. and ECNP. All rights reserved.

Circadian homeostatis of liver metabolism suppresses hepatocarcinogenesis

USDA-ARS?s Scientific Manuscript database

Chronic jet lag induces spontaneous hepatocellular carcinoma (HCC) in wild-type mice following a mechanism very similar to that observed in obese humans. The process initiates with non-alcoholic fatty liver disease (NAFLD) that progresses to steatohepatitis and fibrosis before HCC detection. This pa...

Influence of Chronic Exposure to Simulated Shift Work on Disease and Longevity in Disease-Prone Inbred Mice

PubMed Central

Toth, Linda A; Trammell, Rita A; Liberati, Teresa; Verhulst, Steve; Hart, Marcia L; Moskowitz, Jacob E; Franklin, Craig

2017-01-01

Shift work (SW) is viewed as a risk factor for the development of many serious health conditions, yet prospective studies that document such risks are rare. The current study addressed this void by testing the hypothesis that long-term exposure to repeated diurnal phase shifts, mimicking SW, will accelerate disease onset or death in inbred mice with genetic risk of developing cancer, diabetes, or autoimmune disease. The data indicate that 1) life-long exposure to simulated SW accelerates death in female cancer-prone AKR/J mice; 2) a significant proportion of male NON/ShiLtJ mice, which have impaired glucose tolerance but do not normally progress to type 2 diabetes, develop hyperglycemia, consistent with diabetes (that is, blood glucose 250 mg/dL or greater) after exposure to simulated SW for 8 wk; and 3) MRL/MpJ mice, which are prone to develop autoimmune disease, showed sex-related acceleration of disease development when exposed to SW as compared with mice maintained on a stable photocycle. Thus, long-term exposure to diurnal phase shifts that mimic SW reduces health or longevity in a wide variety of disease models. Our approach provides a simple way to assess the effect of chronic diurnal disruption in disease development in at-risk genotypes. PMID:28381312

Voluntary Exercise Produces Antidepressant and Anxiolytic Behavioral Effects in Mice

PubMed Central

Duman, Catharine H.; Schlesinger, Lee; Russell, David S.; Duman, Ronald S.

2008-01-01

Reports of beneficial effects of exercise on psychological health in humans are increasingly supported by basic research studies. Exercise is hypothesized to regulate antidepressant-related mechanisms and we therefore characterized the effects of chronic exercise in mouse behavioral paradigms relevant to antidepressant actions. Mice given free access to running wheels showed antidepressant-like behavior in learned helplessness, forced-swim (FST) and tail suspension paradigms. These responses were similar to responses of antidepressant drug-treated animals. When tested under conditions where locomotor activity was not altered, exercising mice also showed reduced anxiety compared to sedentary control mice. In situ hybridization analysis showed that BDNF mRNA was increased in specific subfields of hippocampus after wheel running. We chose one paradigm, the FST, in which to investigate a functional role for brain-derived neurotrophic factor (BDNF) in the behavioral response to exercise. We tested mice heterozygous for a deletion of the BDNF gene in the FST after wheel-running. Exercising wild-type mice showed the expected antidepressant-like behavioral response in the FST but exercise was ineffective in improving FST performance in heterozygous BDNF knockout mice. A possible functional contribution of a BDNF signaling pathway to FST performance in exercising mice was investigated using the specific MEK inhibitor PD184161 to block the MAPK signaling pathway. Subchronic administration of PD184161 to exercising mice blocked the antidepressant-like behavioral response seen in vehicle-treated exercising mice in the FST. In summary, chronic wheel-running exercise in mice results in antidepressant-like behavioral changes that may involve a BDNF related mechanism similar to that hypothesized for antidepressant drug treatment. PMID:18267317

Role of T Cell TGF-β Signaling in Intestinal Cytokine Responses and Helminthic Immune Modulation

PubMed Central

Ince, M. Nedim; Elliott, David E.; Setiawan, Tommy; Metwali, Ahmed; Blum, Arthur; Chen, Hung-lin; Urban, Joseph F.; Flavell, Richard A.; Weinstock, Joel V.

2010-01-01

Colonization with helminthic parasites induces mucosal regulatory cytokines, like IL-10 or TGF-β that are important in suppressing colitis. Helminths induce mucosal T cell IL-10 secretion and regulate lamina propria mononuclear cell Th1 cytokine generation in an IL-10 dependent manner in wild-type mice. Helminths also stimulate mucosal TGF-β release. As TGF-β exerts major regulatory effects on T lymphocytes, we investigated the role of T lymphocyte TGF-β signaling in helminthic modulation of intestinal immunity. T cell TGF-β signaling is interrupted in TGF-βRII DN mice by T cell-specific over-expression of a dominant negative TGF-β receptor II. We studied lamina propria mononuclear cell responses in wild-type and TGF-βRII DN mice that were uninfected or colonized with the nematode, Heligmosomoides polygyrus. Our results indicate an essential role of T cell TGF-β signaling in limiting mucosal Th1 and Th2 responses. Furthermore, we demonstrate that helminthic induction of intestinal T cell IL-10 secretion requires intact T cell TGF-β signaling pathway. Helminths fail to curtail robust, dysregulated intestinal Th1 cytokine production and chronic colitis in TGF-βRII DN mice. Thus, T cell TGF-β signaling is essential for helminthic stimulation of mucosal IL-10 production, helminthic modulation of intestinal interferon-γ generation and H. polygyrus-mediated suppression of chronic colitis. PMID:19544487

Continuing Treatment with Salvia miltiorrhiza Injection Attenuates Myocardial Fibrosis in Chronic Iron-Overloaded Mice

PubMed Central

Zhang, Ying; Wang, Hao; Cui, Lijing; Zhang, Yuanyuan; Liu, Yang; Chu, Xi; Liu, Zhenyi; Zhang, Jianping; Chu, Li

2015-01-01

Iron overload cardiomyopathy results from iron accumulation in the myocardium that is closely linked to iron-mediated myocardial fibrosis. Salvia miltiorrhiza (SM, also known as Danshen), a traditional Chinese medicinal herb, has been widely used for hundreds of years to treat cardiovascular diseases. Here, we investigated the effect and potential mechanism of SM on myocardial fibrosis induced by chronic iron overload (CIO) in mice. Kunming male mice (8 weeks old) were randomized to six groups of 10 animals each: control (CONT), CIO, low-dose SM (L-SM), high-dose SM (H-SM), verapamil (VRP) and deferoxamine (DFO) groups. Normal saline was injected in the CONT group. Mice in the other five groups were treated with iron dextran at 50 mg/kg per day intraperitoneally for 7 weeks, and those in the latter four groups also received corresponding daily treatments, including 3 g/kg or 6 g/kg of SM, 100 mg/kg of VRP, or 100 mg/kg of DFO. The iron deposition was estimated histologically using Prussian blue staining. Myocardial fibrosis was determined by Masson’s trichrome staining and hydroxyproline (Hyp) quantitative assay. Superoxide dismutase (SOD) activity, malondialdehyde (MDA) content and protein expression levels of type I collagen (COL I), type I collagen (COL III), transforming growth factor-β1 (TGF-β1) and matrix metalloproteinase-9 (MMP-9) were analyzed to investigate the mechanisms underlying the effects of SM against iron-overloaded fibrosis. Treatment of chronic iron-overloaded mice with SM dose-dependently reduced iron deposition levels, fibrotic area percentage, Hyp content, expression levels of COL I and COL III, as well as upregulated the expression of TGF- β1 and MMP-9 proteins in the heart. Moreover, SM treatment decreased MDA content and increased SOD activity. In conclusion, SM exerted activities against cardiac fibrosis induced by CIO, which may be attributed to its inhibition of iron deposition, as well as collagen metabolism and oxidative stress. PMID:25850001

Phenotypic Characterization of a Novel Virulence-Factor Deletion Strain of Burkholderia mallei That Provides Partial Protection against Inhalational Glanders in Mice.

PubMed

Bozue, Joel A; Chaudhury, Sidhartha; Amemiya, Kei; Chua, Jennifer; Cote, Christopher K; Toothman, Ronald G; Dankmeyer, Jennifer L; Klimko, Christopher P; Wilhelmsen, Catherine L; Raymond, Jolynn W; Zavaljevski, Nela; Reifman, Jaques; Wallqvist, Anders

2016-01-01

Burkholderia mallei (Bm) is a highly infectious intracellular pathogen classified as a category B biological agent by the Centers for Disease Control and Prevention. After respiratory exposure, Bm establishes itself within host macrophages before spreading into major organ systems, which can lead to chronic infection, sepsis, and death. Previously, we combined computational prediction of host-pathogen interactions with yeast two-hybrid experiments and identified novel virulence factor genes in Bm, including BMAA0553, BMAA0728 (tssN), and BMAA1865. In the present study, we used recombinant allelic exchange to construct deletion mutants of BMAA0553 and tssN (ΔBMAA0553 and ΔTssN, respectively) and showed that both deletions completely abrogated virulence at doses of >100 times the LD50 of the wild-type Bm strain. Analysis of ΔBMAA0553- and ΔTssN-infected mice showed starkly reduced bacterial dissemination relative to wild-type Bm, and subsequent in vitro experiments characterized pathogenic phenotypes with respect to intracellular growth, macrophage uptake and phagosomal escape, actin-based motility, and multinucleated giant cell formation. Based on observed in vitro and in vivo phenotypes, we explored the use of ΔTssN as a candidate live-attenuated vaccine. Mice immunized with aerosolized ΔTssN showed a 21-day survival rate of 67% after a high-dose aerosol challenge with the wild-type Bm ATCC 23344 strain, compared to a 0% survival rate for unvaccinated mice. However, analysis of histopathology and bacterial burden showed that while the surviving vaccinated mice were protected from acute infection, Bm was still able to establish a chronic infection. Vaccinated mice showed a modest IgG response, suggesting a limited potential of ΔTssN as a vaccine candidate, but also showed prolonged elevation of pro-inflammatory cytokines, underscoring the role of cellular and innate immunity in mitigating acute infection in inhalational glanders.

Phenotypic Characterization of a Novel Virulence-Factor Deletion Strain of Burkholderia mallei That Provides Partial Protection against Inhalational Glanders in Mice

PubMed Central

Bozue, Joel A.; Chaudhury, Sidhartha; Amemiya, Kei; Chua, Jennifer; Cote, Christopher K.; Toothman, Ronald G.; Dankmeyer, Jennifer L.; Klimko, Christopher P.; Wilhelmsen, Catherine L.; Raymond, Jolynn W.; Zavaljevski, Nela; Reifman, Jaques; Wallqvist, Anders

2016-01-01

Burkholderia mallei (Bm) is a highly infectious intracellular pathogen classified as a category B biological agent by the Centers for Disease Control and Prevention. After respiratory exposure, Bm establishes itself within host macrophages before spreading into major organ systems, which can lead to chronic infection, sepsis, and death. Previously, we combined computational prediction of host-pathogen interactions with yeast two-hybrid experiments and identified novel virulence factor genes in Bm, including BMAA0553, BMAA0728 (tssN), and BMAA1865. In the present study, we used recombinant allelic exchange to construct deletion mutants of BMAA0553 and tssN (ΔBMAA0553 and ΔTssN, respectively) and showed that both deletions completely abrogated virulence at doses of >100 times the LD50 of the wild-type Bm strain. Analysis of ΔBMAA0553- and ΔTssN-infected mice showed starkly reduced bacterial dissemination relative to wild-type Bm, and subsequent in vitro experiments characterized pathogenic phenotypes with respect to intracellular growth, macrophage uptake and phagosomal escape, actin-based motility, and multinucleated giant cell formation. Based on observed in vitro and in vivo phenotypes, we explored the use of ΔTssN as a candidate live-attenuated vaccine. Mice immunized with aerosolized ΔTssN showed a 21-day survival rate of 67% after a high-dose aerosol challenge with the wild-type Bm ATCC 23344 strain, compared to a 0% survival rate for unvaccinated mice. However, analysis of histopathology and bacterial burden showed that while the surviving vaccinated mice were protected from acute infection, Bm was still able to establish a chronic infection. Vaccinated mice showed a modest IgG response, suggesting a limited potential of ΔTssN as a vaccine candidate, but also showed prolonged elevation of pro-inflammatory cytokines, underscoring the role of cellular and innate immunity in mitigating acute infection in inhalational glanders. PMID:26955620

Migraine prophylaxis, ischemic depolarizations and stroke outcomes in mice

PubMed Central

Eikermann-Haerter, Katharina; Lee, Jeong Hyun; Yalcin, Nilufer; Yu, Esther Sori; Daneshmand, Ali; Wei, Ying; Zheng, Yi; Can, Anil; Sengul, Buse; Ferrari, Michel D.; van den Maagdenberg, Arn M. J. M.; Ayata, Cenk

2014-01-01

Background and Purpose Migraine with aura is an established stroke risk factor, and excitatory mechanisms such as spreading depression are implicated in the pathogenesis of both migraine and stroke. Spontaneous spreading depression waves originate within the peri-infarct tissue and exacerbate the metabolic mismatch during focal cerebral ischemia. Genetically enhanced spreading depression susceptibility facilitates anoxic depolarizations and peri-infarct spreading depressions and accelerates infarct growth, suggesting that susceptibility to spreading depression is a critical determinant of vulnerability to ischemic injury. Because chronic treatment with migraine prophylactic drugs suppresses spreading depression susceptibility, we tested whether migraine prophylaxis can also suppress ischemic depolarizations and improve stroke outcome. Methods We measured the cortical susceptibility to spreading depression and ischemic depolarizations, and determined tissue and neurological outcome after middle cerebral artery occlusion in wild type and familial hemiplegic migraine type 1 knock-in mice treated with vehicle, topiramate or lamotrigine daily for 7 weeks or as a single dose shortly before testing. Results Chronic treatment with topiramate or lamotrigine reduces the susceptibility to KCl- or electrical stimulation-induced spreading depressions as well as ischemic depolarizations in both wild-type and familial hemiplegic migraine type 1 mutant mice. Consequently, both tissue and neurological outcomes are improved. Notably, treatment with a single dose of either drug is ineffective. Conclusions These data underscore the importance of hyperexcitability as a mechanism for increased stroke risk in migraineurs, and suggest that migraine prophylaxis may not only prevent migraine attacks but also protect migraineurs against ischemic injury. PMID:25424478

FGF21 is dispensable for hypothermia induced by fasting in mice.

PubMed

Oishi, Katsutaka; Sakamoto, Katsuhiko; Konishi, Morichika; Murata, Yusuke; Itoh, Nobuyuki; Sei, Hiroyoshi

2010-01-01

Fibroblast growth factor 21 (FGF21) is a key metabolic regulator that is induced by peroxisome proliferator-activated receptor alpha (PPARalpha) activation in response to fasting. We recently reported that bezafibrate, a pan-agonist of PPARs, decreases body temperature late at night through hypothalamic neuropeptide Y (NPY) activation and others have shown that mice overexpressing FGF21 are prone to torpor. We examined whether FGF21 is essential for fasting-induced hypothermia using FGF21 knockout (KO) mice. Acute fasting decreased body temperature late at night accompanied by the induction of hepatic FGF21 and hypothalamic NPY expression in wild-type mice. A deficiency of FGF21 affected neither fasting-induced hypothermia nor hypothalamic NPY induction. Fasting enhanced locomotor activity in both genotypes. On the other hand, a deficiency of FGF21 significantly attenuated chronic hypothermia and hypoactivity induced by a ketogenic diet (KD). Our findings suggest that FGF21 is not essential for the hypothermia that is associated with the early stages of fasting, although it might be involved in the adaptive response of body temperature to chronic starvation.

Chronic Exposure to Anabolic Androgenic Steroids Alters Neuronal Function in the Mammalian Forebrain via Androgen Receptor- and Estrogen Receptor-Mediated Mechanisms

PubMed Central

Penatti, Carlos A A; Porter, Donna M; Henderson, Leslie P

2009-01-01

Anabolic androgenic steroids (AAS) can promote detrimental effects on social behaviors for which γ-aminobutyric acid type A (GABAA) receptor-mediated circuits in the forebrain play a critical role. While all AAS bind to androgen receptors (AR), they may also be aromatized to estrogens and thus potentially impart effects via estrogen receptors (ER). Chronic exposure of wild type male mice to a combination of chemically distinct AAS increased action potential (AP) frequency, selective GABAA receptor subunit mRNAs, and GABAergic synaptic current decay in the medial preoptic area (mPOA). Experiments performed with pharmacological agents and in AR-deficient Tfm mutant mice suggest that the AAS-dependent enhancement of GABAergic transmission in wild type mice is AR-mediated. In AR-deficient mice, the AAS elicited dramatically different effects, decreasing AP frequency, sIPSC amplitude and frequency and the expression of selective GABAA receptor subunit mRNAs. Surprisingly, in the absence of AR signaling, the data indicate that the AAS do not act as ER agonists, but rather suggest a novel in vivo action in which the AAS inhibit aromatase and impair endogenous ER signaling. These results show that the AAS have the capacity to alter neuronal function in the forebrain via multiple steroid signaling mechanisms and suggest that effects of these steroids in the brain will depend not only on the balance of AR- vs. ER-mediated regulation for different target genes, but also on the ability of these drugs to alter steroid metabolism and thus the endogenous steroid milieu. PMID:19812324

Anti-Inflammatory Properties of Brazilian Green Propolis Encapsulated in a γ-Cyclodextrin Complex in Mice Fed a Western-Type Diet.

PubMed

Rimbach, Gerald; Fischer, Alexandra; Schloesser, Anke; Jerz, Gerold; Ikuta, Naoko; Ishida, Yoshiyuki; Matsuzawa, Ryota; Matsugo, Seiichi; Huebbe, Patricia; Terao, Keiji

2017-05-26

Ageing is often accompanied by chronic inflammation. A fat- and sugar-rich Western-type diet (WTD) may accelerate the ageing phenotype. Cell culture studies have indicated that artepillin C-containing Brazilian green propolis exhibits anti-inflammatory properties. However, little is known regarding its anti-inflammatory potential in mouse liver in vivo. In this study, female C57BL/6NRj wild-type mice were fed a WTD, a WTD supplemented with Brazilian green propolis supercritical extract (GPSE) encapsulated in γ-cyclodextrin (γCD) or a WTD plus γCD for 10 weeks. GPSE-γCD did not affect the food intake, body weight or body composition of the mice. However, mRNA levels of the tumour necrosis factor α were significantly downregulated ( p < 0.05) in these mice compared to those in the WTD-fed controls. Furthermore, the gene expression levels of other pro-inflammatory markers, including serum amyloid P, were significantly ( p < 0.001) decreased following GPSE-γCD treatment. GPSE-γCD significantly induced hepatic ferritin gene expression ( p < 0.01), which may contribute to its anti-inflammatory properties. Conversely, GPSE-γCD did not affect the biomarkers of endogenous antioxidant defence, including catalase, glutathione peroxidase-4, paraoxonase-1, glutamate cysteine ligase and nuclear factor erythroid 2-related factor-2 (Nrf2). Overall, the present data suggest that dietary GPSE-γCD exhibits anti-inflammatory, but not antioxidant activity in mouse liver in vivo. Thus, GPSE-γCD has the potential to serve as a natural hepatoprotective bioactive compound for dietary-mediated strategies against chronic inflammation.

Differential effect of T-type voltage-gated Ca2+ channel disruption on renal plasma flow and glomerular filtration rate in vivo.

PubMed

Thuesen, Anne D; Andersen, Henrik; Cardel, Majken; Toft, Anja; Walter, Steen; Marcussen, Niels; Jensen, Boye L; Bie, Peter; Hansen, Pernille B L

2014-08-15

Voltage-gated Ca(2+) (Cav) channels play an essential role in the regulation of renal blood flow and glomerular filtration rate (GFR). Because T-type Cav channels are differentially expressed in pre- and postglomerular vessels, it was hypothesized that they impact renal blood flow and GFR differentially. The question was addressed with the use of two T-type Cav knockout (Cav3.1(-/-) and Cav3.2(-/-)) mouse strains. Continuous recordings of blood pressure and heart rate, para-aminohippurate clearance (renal plasma flow), and inulin clearance (GFR) were performed in conscious, chronically catheterized, wild-type (WT) and Cav3.1(-/-) and Cav3.2(-/-) mice. The contractility of afferent and efferent arterioles was determined in isolated perfused blood vessels. Efferent arterioles from Cav3.2(-/-) mice constricted significantly more in response to a depolarization compared with WT mice. GFR was increased in Cav3.2(-/-) mice with no significant changes in renal plasma flow, heart rate, and blood pressure. Cav3.1(-/-) mice had a higher renal plasma flow compared with WT mice, whereas GFR was indistinguishable from WT mice. No difference in the concentration response to K(+) was observed in isolated afferent and efferent arterioles from Cav3.1(-/-) mice compared with WT mice. Heart rate was significantly lower in Cav3.1(-/-) mice compared with WT mice with no difference in blood pressure. T-type antagonists significantly inhibited the constriction of human intrarenal arteries in response to a small depolarization. In conclusion, Cav3.2 channels support dilatation of efferent arterioles and affect GFR, whereas Cav3.1 channels in vivo contribute to renal vascular resistance. It is suggested that endothelial and nerve localization of Cav3.2 and Cav3.1, respectively, may account for the observed effects. Copyright © 2014 the American Physiological Society.

Exogenous Stimulation of Type I Interferon Protects Mice with Chronic Granulomatous Disease from Aspergillosis through Early Recruitment of Host-Protective Neutrophils into the Lung.

PubMed

Seyedmousavi, Seyedmojtaba; Davis, Michael J; Sugui, Janyce A; Pinkhasov, Tzvia; Moyer, Shannon; Salazar, Andres M; Chang, Yun C; Kwon-Chung, Kyung J

2018-03-27

Invasive aspergillosis (IA) remains the primary cause of morbidity and mortality in chronic granulomatous disease (CGD) patients, often due to infection by Aspergillus species refractory to antifungals. This motivates the search for alternative treatments, including immunotherapy. We investigated the effect of exogenous type I interferon (IFN) activation on the outcome of IA caused by three Aspergillus species, A. fumigatus , A. nidulans , and A. tanneri , in CGD mice. The animals were treated with poly(I):poly(C) carboxymethyl cellulose poly-l-lysine (PICLC), a mimetic of double-stranded RNA, 24 h preinfection and postinfection. The survival rates and lung fungal burdens were markedly improved by PICLC immunotherapy in animals infected with any one of the three Aspergillus species. While protection from IA was remarkable, PICLC induction of type I IFN in the lungs surged 24 h posttreatment and returned to baseline levels by 48 h, suggesting that PICLC altered early events in protection against IA. Immunophenotyping of recruited leukocytes and histopathological examination of tissue sections showed that PICLC induced similar cellular infiltrates as those in untreated-infected mice, in both cases dominated by monocytic cells and neutrophils. However, the PICLC immunotherapy resulted in a marked earlier recruitment of the leukocytes. Unlike with conidia, infection with A. nidulans germlings reduced the protective effect of PICLC immunotherapy. Additionally, antibody depletion of neutrophils totally reversed the protection, suggesting that neutrophils are crucial for PICLC-mediated protection. Together, these data show that prophylactic PICLC immunotherapy prerecruits these cells, enabling them to attack the conidia and thus resulting in a profound protection from IA. IMPORTANCE Patients with chronic granulomatous disease (CGD) are highly susceptible to invasive aspergillosis (IA). While Aspergillus fumigatus is the most-studied Aspergillus species, CGD patients often suffer IA caused by A. nidulans , A. tanneri , and other rare species. These non- fumigatus Aspergillus species are more resistant to antifungal drugs and cause higher fatality rates than A. fumigatus Therefore, alternative therapies are needed to protect CGD patients. We report an effective immunotherapy of mice infected with three Aspergillus species via PICLC dosing. While protection from IA was long lasting, PICLC induction of type I IFN surged but quickly returned to baseline levels, suggesting that PICLC was altering early events in IA. Interestingly, we found responding immune cells to be similar between PICLC-treated and untreated-infected mice. However, PICLC immunotherapy resulted in an earlier recruitment of the leukocytes and suppressed fungal growth. This study highlights the value of type I IFN induction in CGD patients.

Chronic administration of recombinant IL-6 upregulates lipogenic enzyme expression and aggravates high-fat-diet-induced steatosis in IL-6-deficient mice

PubMed Central

Vida, Margarita; Gavito, Ana Luisa; Pavón, Francisco Javier; Bautista, Dolores; Serrano, Antonia; Suarez, Juan; Arrabal, Sergio; Decara, Juan; Romero-Cuevas, Miguel; Rodríguez de Fonseca, Fernando; Baixeras, Elena

2015-01-01

ABSTRACT Interleukin-6 (IL-6) has emerged as an important mediator of fatty acid metabolism with paradoxical effects in the liver. Administration of IL-6 has been reported to confer protection against steatosis, but plasma and tissue IL-6 concentrations are elevated in chronic liver diseases, including fatty liver diseases associated with obesity and alcoholic ingestion. In this study, we further investigated the role of IL-6 on steatosis induced through a high-fat diet (HFD) in wild-type (WT) and IL-6-deficient (IL-6−/−) mice. Additionally, HFD-fed IL-6−/− mice were also chronically treated with recombinant IL-6 (rIL-6). Obesity in WT mice fed a HFD associated with elevated serum IL-6 levels, fatty liver, upregulation of carnitine palmitoyltransferase 1 (CPT1) and signal transducer and activator of transcription-3 (STAT3), increased AMP kinase phosphorylation (p-AMPK), and downregulation of the hepatic lipogenic enzymes fatty acid synthase (FAS) and stearoyl-CoA desaturase 1 (SCD1). The HFD-fed IL-6−/− mice showed severe steatosis, no changes in CPT1 levels or AMPK activity, no increase in STAT3 amounts, inactivated STAT3, and marked downregulation of the expression of acetyl-CoA carboxylase (ACCα/β), FAS and SCD1. The IL-6 chronic replacement in HFD-fed IL-6−/− mice restored hepatic STAT3 and AMPK activation but also increased the expression of the lipogenic enzymes ACCα/β, FAS and SCD1. Furthermore, rIL-6 administration was associated with aggravated steatosis and elevated fat content in the liver. We conclude that, in the context of HFD-induced obesity, the administration of rIL-6 might contribute to the aggravation of fatty liver disease through increasing lipogenesis. PMID:26035386

Chronic Anatabine Treatment Reduces Alzheimer’s Disease (AD)-Like Pathology and Improves Socio-Behavioral Deficits in a Transgenic Mouse Model of AD

PubMed Central

Verma, Megha; Beaulieu-Abdelahad, David; Ait-Ghezala, Ghania; Li, Rena; Crawford, Fiona; Mullan, Michael; Paris, Daniel

2015-01-01

Anatabine is a minor tobacco alkaloid, which is also found in plants of the Solanaceae family and displays a chemical structure similarity with nicotine. We have shown previously that anatabine displays some anti-inflammatory properties and reduces microgliosis and tau phosphorylation in a pure mouse model of tauopathy. We therefore investigated the effects of a chronic oral treatment with anatabine in a transgenic mouse model (Tg PS1/APPswe) of Alzheimer’s disease (AD) which displays pathological Aβ deposits, neuroinflammation and behavioral deficits. In the elevated plus maze, Tg PS1/APPswe mice exhibited hyperactivity and disinhibition compared to wild-type mice. Six and a half months of chronic oral anatabine treatment, suppressed hyperactivity and disinhibition in Tg PS1/APPswe mice compared to Tg PS1/APPswe receiving regular drinking water. Tg PS1/APPswe mice also elicited profound social interaction and social memory deficits, which were both alleviated by the anatabine treatment. We found that anatabine reduces the activation of STAT3 and NFκB in the vicinity of Aβ deposits in Tg PS1/APPswe mice resulting in a reduction of the expression of some of their target genes including Bace1, iNOS and Cox-2. In addition, a significant reduction in microgliosis and pathological deposition of Aβ was observed in the brain of Tg PS1/APPswe mice treated with anatabine. This is the first study to investigate the impact of chronic anatabine treatment on AD-like pathology and behavior in a transgenic mouse model of AD. Overall, our data show that anatabine reduces β-amyloidosis, neuroinflammation and alleviates some behavioral deficits in Tg PS1/APPswe, supporting further exploration of anatabine as a possible disease modifying agent for the treatment of AD. PMID:26010758

Antinociceptive and anti-exudative synergism between dexketoprofen and tramadol in a model of inflammatory pain in mice.

PubMed

Miranda, Hugo F; Romero, Maria Asunción; Puig, Margarita M

2012-06-01

Preclinical studies have demonstrated antinociceptive synergism between dexketoprofen (DEX) and tramadol (TRM) in acute animal models of nociception. The aim of the present study was to investigate the type of interaction between DEX and TRM in a chronic musculoskeletal pain model in mice, which fairly replicates the characteristics of chronic osteoarticular pain in humans. Inflammation was induced by a subplantar injection of complete Freund's adjuvant (CFA) in male CF1 mice. Nociceptive thresholds were evaluated using the hot plate, the nocifensive spontaneous behavior and the acetone tests, while plasma extravasation (PE) was assessed with Evan's blue. We used the following experimental groups: control (no inflammation), acute (1 day after CFA injection), and chronic inflammation (7 days after CFA). Dose-response curves for DEX and TRM, individually and combined in a 1 : 1 proportion based on their potency were obtained, and the doses that produced a 50% inhibition calculated. The isobolographic analysis revealed that in all groups of study (no inflammation, acute, and chronic inflammation), the combination of DEX : TRM was synergistic, for both the inhibition of nociception and the PE. The results suggest that the DEX : TRM (1 : 1) combination could be useful in the management of acute and chronic inflammatory musculoskeletal pains in humans; in addition, the synergistic interaction between the drugs observed both during acute and chronic inflammation suggests that less doses would be required of each drug to obtain effective analgesia. © 2011 The Authors Fundamental and Clinical Pharmacology © 2011 Société Française de Pharmacologie et de Thérapeutique.

Chronic treatment with LY341495 decreases 5-HT(2A) receptor binding and hallucinogenic effects of LSD in mice.

PubMed

Moreno, José L; Holloway, Terrell; Rayannavar, Vinayak; Sealfon, Stuart C; González-Maeso, Javier

2013-03-01

Hallucinogenic drugs, such as lysergic acid diethylamide (LSD), mescaline and psilocybin, alter perception and cognitive processes. All hallucinogenic drugs have in common a high affinity for the serotonin 5-HT(2A) receptor. Metabotropic glutamate 2/3 (mGlu2/3) receptor ligands show efficacy in modulating the cellular and behavioral responses induced by hallucinogenic drugs. Here, we explored the effect of chronic treatment with the mGlu2/3 receptor antagonist 2S-2-amino-2-(1S,2S-2-carboxycyclopropan-1-yl)-3-(xanth-9-yl)-propionic acid (LY341495) on the hallucinogenic-like effects induced by LSD (0.24mg/kg). Mice were chronically (21 days) treated with LY341495 (1.5mg/kg), or vehicle, and experiments were carried out one day after the last injection. Chronic treatment with LY341495 down-regulated [(3)H]ketanserin binding in somatosensory cortex of wild-type, but not mGlu2 knockout (KO), mice. Head-twitch behavior, and expression of c-fos, egr-1 and egr-2, which are responses induced by hallucinogenic 5-HT(2A) agonists, were found to be significantly decreased by chronic treatment with LY341495. These findings suggest that repeated blockade of the mGlu2 receptor by LY341495 results in reduced 5-HT(2A) receptor-dependent hallucinogenic effects of LSD. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Corticotropin Releasing Factor in the Bed Nucleus of the Stria Terminalis in Socially Defeated and Non-stressed Mice with a History of Chronic Alcohol Intake.

PubMed

Albrechet-Souza, Lucas; Viola, Thiago W; Grassi-Oliveira, Rodrigo; Miczek, Klaus A; de Almeida, Rosa M M

2017-01-01

Stress exposure has been identified as one risk factor for alcohol abuse that may facilitate the transition from social or regulated use to the development of alcohol dependence. Preclinical studies have shown that dysregulation of the corticotropin releasing factor (CRF) neurotransmission has been implicated in stress-related psychopathologies such as depression and anxiety, and may affect alcohol consumption. The bed nucleus of the stria terminalis (BNST) contains CRF-producing neurons which seem to be sensitive to stress. In this study, adult male C57BL/6 mice previously defeated in resident-intruder confrontations were evaluated in the elevated plus-maze and tail suspension test. Mice were also tested for sweet solution intake before and after social stress. After having had continuous access to ethanol (20% weight/volume) for 4 weeks, control and stressed mice had CRF type 1 (CRFR1) or type 2 (CRFR2) receptor antagonists infused into the BNST and then had access to ethanol for 24 h. In separate cohorts of control and stressed mice, we assessed mRNA levels of BNST CRF, CRFR1 and CRFR2 . Stressed mice increased their intake of sweet solution after ten sessions of social defeat and showed reduced activity in the open arms of the elevated plus-maze. When tested for ethanol consumption, stressed mice persistently drank significantly more than controls during the 4 weeks of access. Also, social stress induced higher BNST CRF mRNA levels. The selective blockade of BNST CRFR1 with CP376,395 effectively reduced alcohol drinking in non-stressed mice, whereas the selective CRFR2 antagonist astressin2B produced a dose-dependent increase in ethanol consumption in both non-stressed controls and stressed mice. The 10-day episodic defeat stress used here elicited anxiety- but not depressive-like behaviors, and promoted an increase in ethanol drinking. CRF-CRFR1 signaling in the BNST seems to underlie ethanol intake in non-stressed mice, whereas CRFR2 modulates alcohol consumption in both socially defeated and non-stressed mice with a history of chronic intake.

TRPV1 and the MCP-1/CCR2 Axis Modulate Post-UTI Chronic Pain.

PubMed

Rosen, John M; Yaggie, Ryan E; Woida, Patrick J; Miller, Richard J; Schaeffer, Anthony J; Klumpp, David J

2018-05-08

The etiology of chronic pelvic pain syndromes remains unknown. In a murine urinary tract infection (UTI) model, lipopolysaccharide of uropathogenic E. coli and its receptor TLR4 are required for post-UTI chronic pain development. However, downstream mechanisms of post-UTI chronic pelvic pain remain unclear. Because the TRPV1 and MCP-1/CCR2 pathways are implicated in chronic neuropathic pain, we explored their role in post-UTI chronic pain. Mice were infected with the E. coli strain SΦ874, known to produce chronic allodynia, and treated with the TRPV1 antagonist capsazepine. Mice treated with capsazepine at the time of SΦ874 infection failed to develop chronic allodynia, whereas capsazepine treatment of mice at two weeks following SΦ874 infection did not reduce chronic allodynia. TRPV1-deficient mice did not develop chronic allodynia either. Similar results were found using novelty-suppressed feeding (NSF) to assess depressive behavior associated with neuropathic pain. Imaging of reporter mice also revealed induction of MCP-1 and CCR2 expression in sacral dorsal root ganglia following SΦ874 infection. Treatment with a CCR2 receptor antagonist at two weeks post-infection reduced chronic allodynia. Taken together, these results suggest that TRPV1 has a role in the establishment of post-UTI chronic pain, and CCR2 has a role in maintenance of post-UTI chronic pain.

Bilirubin Increases Insulin Sensitivity in Leptin-Receptor Deficient and Diet-Induced Obese Mice Through Suppression of ER Stress and Chronic Inflammation

PubMed Central

Dong, Huansheng; Huang, Hu; Yun, Xinxu; Kim, Do-sung; Yue, Yinan; Wu, Hongju; Sutter, Alton; Chavin, Kenneth D.; Otterbein, Leo E.; Adams, David B.; Kim, Young-Bum

2014-01-01

Obesity-induced endoplasmic reticulum (ER) stress causes chronic inflammation in adipose tissue and steatosis in the liver, and eventually leads to insulin resistance and type 2 diabetes (T2D). The goal of this study was to understand the mechanisms by which administration of bilirubin, a powerful antioxidant, reduces hyperglycemia and ameliorates obesity in leptin-receptor-deficient (db/db) and diet-induced obese (DIO) mouse models. db/db or DIO mice were injected with bilirubin or vehicle ip. Blood glucose and body weight were measured. Activation of insulin-signaling pathways, expression of inflammatory cytokines, and ER stress markers were measured in skeletal muscle, adipose tissue, and liver of mice. Bilirubin administration significantly reduced hyperglycemia and increased insulin sensitivity in db/db mice. Bilirubin treatment increased protein kinase B (PKB/Akt) phosphorylation in skeletal muscle and suppressed expression of ER stress markers, including the 78-kDa glucose-regulated protein (GRP78), CCAAT/enhancer-binding protein (C/EBP) homologous protein, X box binding protein (XBP-1), and activating transcription factor 4 in db/db mice. In DIO mice, bilirubin treatment significantly reduced body weight and increased insulin sensitivity. Moreover, bilirubin suppressed macrophage infiltration and proinflammatory cytokine expression, including TNF-α, IL-1β, and monocyte chemoattractant protein-1, in adipose tissue. In liver and adipose tissue of DIO mice, bilirubin ameliorated hepatic steatosis and reduced expression of GRP78 and C/EBP homologous protein. These results demonstrate that bilirubin administration improves hyperglycemia and obesity by increasing insulin sensitivity in both genetically engineered and DIO mice models. Bilirubin or bilirubin-increasing drugs might be useful as an insulin sensitizer for the treatment of obesity-induced insulin resistance and type 2 diabetes based on its profound anti-ER stress and antiinflammatory properties. PMID:24424052

Monoacylglycerol Lipase Inhibitor JZL184 Improves Behavior and Neural Properties in Ts65Dn Mice, a Model of Down Syndrome

PubMed Central

Lysenko, Larisa V.; Kim, Jeesun; Henry, Cassandra; Tyrtyshnaia, Anna; Kohnz, Rebecca A.; Madamba, Francisco; Simon, Gabriel M.; Kleschevnikova, Natalia E.; Nomura, Daniel K.; Ezekowitz, R . Alan B.; Kleschevnikov, Alexander M.

2014-01-01

Genetic alterations or pharmacological treatments affecting endocannabinoid signaling have profound effects on synaptic and neuronal properties and, under certain conditions, may improve higher brain functions. Down syndrome (DS), a developmental disorder caused by triplication of chromosome 21, is characterized by deficient cognition and inevitable development of the Alzheimer disease (AD) type pathology during aging. Here we used JZL184, a selective inhibitor of monoacylglycerol lipase (MAGL), to examine the effects of chronic MAGL inhibition on the behavioral, biochemical, and synaptic properties of aged Ts65Dn mice, a genetic model of DS. In both Ts65Dn mice and their normosomic (2N) controls, JZL184-treatment increased brain levels of 2-arachidonoylglycerol (2-AG) and decreased levels of its metabolites such as arachidonic acid, prostaglandins PGD2, PGE2, PGFα, and PGJ2. Enhanced spontaneous locomotor activity of Ts65Dn mice was reduced by the JZL184-treatement to the levels observed in 2N animals. Deficient long-term memory was also improved, while short-term and working types of memory were unaffected. Furthermore, reduced hippocampal long-term potentiation (LTP) was increased in the JZL184-treated Ts65Dn mice to the levels observed in 2N mice. Interestingly, changes in synaptic plasticity and behavior were not observed in the JZL184-treated 2N mice suggesting that the treatment specifically attenuated the defects in the trisomic animals. The JZL184-treatment also reduced the levels of Aβ40 and Aβ42, but had no effect on the levels of full length APP and BACE1 in both Ts65Dn and 2N mice. These data show that chronic MAGL inhibition improves the behavior and brain functions in a DS model suggesting that pharmacological targeting of MAGL may be considered as a perspective new approach for improving cognition in DS. PMID:25474204

Glucocorticoid-mediated activation of GSK3β promotes tau phosphorylation and impairs memory in type 2 diabetes.

PubMed

Dey, Aditi; Hao, Shuai; Wosiski-Kuhn, Marlena; Stranahan, Alexis M

2017-09-01

Type 2 diabetes is increasingly recognized as a risk factor for Alzheimer's disease, but the underlying mechanisms remain poorly understood. Hyperphosphorylation of the microtubule-associated protein tau has been reported in rodent models of diabetes, including db/db mice, which exhibit insulin resistance and chronically elevated glucocorticoids due to leptin receptor insufficiency. In this report, we investigated endocrine mechanisms for hippocampal tau phosphorylation in db/db and wild-type mice. By separately manipulating peripheral and intrahippocampal corticosterone levels, we determined that hippocampal corticosteroid exposure promotes tau phosphorylation and activates glycogen synthase kinase 3β (GSK3β). Subsequent experiments in hippocampal slice preparations revealed evidence for a nongenomic interaction between glucocorticoids and GSK3β. To examine whether GSK3β activation mediates tau phosphorylation and impairs memory in diabetes, db/db and wild-type mice received intrahippocampal infusions of TDZD-8, a non-ATP competitive thiadiazolidinone inhibitor of GSK3β. Intrahippocampal TDZD-8 blocked tau hyperphosphorylation and normalized hippocampus-dependent memory in db/db mice, suggesting that pathological synergy between diabetes and Alzheimer's disease may involve glucocorticoid-mediated activation of GSK3β. Copyright © 2017 Elsevier Inc. All rights reserved.

Mice overexpressing latent matrix metalloproteinase-2 develop lung emphysema after short-term exposure to cigarette smoke extract.

PubMed

Onishi, Masahiro; Kobayashi, Tetsu; D'Alessandro-Gabazza, Corina N; Fujimoto, Hajime; Chelakkot-Govindalayathil, Ayshwarya-Lakshmi; Takahashi, Yoshinori; Yasuma, Taro; Nishihama, Kota; Toda, Masaaki; Takei, Yoshiyuki; Taguchi, Osamu; Gabazza, Esteban C

2018-02-26

Chronic obstructive pulmonary disease is the major growing cause of mortality and morbidity worldwide, and it is going to become the third most common cause of death by 2020. Chronic obstructive pulmonary disease is pathologically characterized by lung emphysema and small airway inflammation. Animal models are very important to get insights into the disease pathogenesis but current models of chronic obstructive pulmonary disease take a long time to develop. The need of a new model is compelling. In the present study we focus on the role of matrix metalloproteinases in the pathogenesis of chronic obstructive pulmonary disease and hypothesized that lung overexpression of latent matrix metalloproteinases-2 would allow the development of emphysema after short-term exposure to cigarette smoke extract inhalation. Human latent matrix metalloproteinases-2 transgenic mouse expressing high level of the protein in the lungs and wild type mouse were exposed to aerosolized cigarette smoke extract for two weeks. Transgenic mice showed significant lung emphysematous changes, increased infiltration of inflammatory cells and enhanced lung concentrations of inflammatory cytokines in the lungs compared to their wild type counterparts after inhalation of cigarette smoke extract. This novel mouse model will be a very useful tool for evaluating the mechanistic pathways and for development of novel therapies in cigarette smoke-associated lung emphysema. Copyright © 2018 Elsevier Inc. All rights reserved.

Chronic psychosocial stress causes delayed extinction and exacerbates reinstatement of ethanol-induced conditioned place preference in mice.

PubMed

Bahi, Amine; Dreyer, Jean-Luc

2014-01-01

We have shown previously, using an animal model of voluntary ethanol intake and ethanol-conditioned place preference (EtOH-CPP), that exposure to chronic psychosocial stress induces increased ethanol intake and EtOH-CPP acquisition in mice. Here, we examined the impact of chronic subordinate colony (CSC) exposure on EtOH-CPP extinction, as well as ethanol-induced reinstatement of CPP. Mice were conditioned with saline or 1.5 g/kg ethanol and were tested in the EtOH-CPP model. In the first experiment, the mice were subjected to 19 days of chronic stress, and EtOH-CPP extinction was assessed during seven daily trials without ethanol injection. In the second experiment and after the EtOH-CPP test, the mice were subjected to 7 days of extinction trials before the 19 days of chronic stress. Drug-induced EtOH-CPP reinstatement was induced by a priming injection of 0.5 g/kg ethanol. Compared to the single-housed colony mice, CSC mice exhibited increased anxiety-like behavior in the elevated plus maze (EPM) and the open field tests. Interestingly, the CSC mice showed delayed EtOH-CPP extinction. More importantly, CSC mice showed increased alcohol-induced reinstatement of the EtOH-CPP behavior. Taken together, this study indicates that chronic psychosocial stress can have long-term effects on EtOH-CPP extinction as well as drug-induced reinstatement behavior and may provide a suitable model to study the latent effects of chronic psychosocial stress on extinction and relapse to drug abuse.

Cardiovascular phenotype in Smad3 deficient mice with renovascular hypertension.

PubMed

Kashyap, Sonu; Warner, Gina; Hu, Zeng; Gao, Feng; Osman, Mazen; Al Saiegh, Yousif; Lien, Karen R; Nath, Karl; Grande, Joseph P

2017-01-01

Renovascular hypertension (RVH) has deleterious effects on both the kidney and the heart. TGF-β signaling through Smad3 directs tissue fibrosis in chronic injury models. In the 2-kidney 1-clip (2K1C) model of RVH, employing mice on the 129 genetic background, Smad3 deficiency (KO) protects the stenotic kidney (STK) from development of interstitial fibrosis. However, these mice have an increased incidence of sudden cardiac death following 2K1C surgery. The purpose of this study was to characterize the cardiovascular phenotype of these mice. Renal artery stenosis (RAS) was established in Wild-type (WT) and Smad3 KO mice (129 genetic background) by placement of a polytetrafluoroethylene cuff on the right renal artery. Mortality was 25.5% for KO mice with RAS, 4.1% for KO sham mice, 1.2% for WT with RAS, and 1.8% for WT sham mice. Myocardial tissue of mice studied at 3 days following surgery showed extensive myocyte necrosis in KO but not WT mice. Myocyte necrosis was associated with a rapid induction of Ccl2 expression, macrophage influx, and increased MMP-9 activity. At later time points, both KO and WT mice developed myocardial fibrosis. No aortic aneurysms or dissections were observed at any time point. Smad3 KO mice were backcrossed to the C57BL/6J strain and subjected to RAS. Sudden death was observed at 10-14 days following surgery in 62.5% of mice; necropsy revealed aortic dissections as the cause of death. As observed in the 129 mice, the STK of Smad3 KO mice on the C57BL/6J background did not develop significant chronic renal damage. We conclude that the cardiovascular manifestations of Smad3 deficient mice are strain-specific, with myocyte necrosis in 129 mice and aortic rupture in C57BL/6J mice. Future studies will define mechanisms underlying this strain-specific effect on the cardiovascular system.

Impaired ventilatory acclimatization to hypoxia in female mice overexpressing erythropoietin: unexpected deleterious effect of estradiol in carotid bodies.

PubMed

Gassmann, Max; Pfistner, Christine; Doan, Van Diep; Vogel, Johannes; Soliz, Jorge

2010-12-01

Apart from enhancing the production of red blood cells, erythropoietin (Epo) alters the ventilatory response when oxygen supply is reduced. We recently demonstrated that Epo's beneficial effect on the ventilatory response to acute hypoxia is sex dependent, with female mice being better able to cope with reduced oxygenation. In the present work, we hypothesized that ventilatory acclimatization to chronic hypoxia (VAH) in transgenic female mice (Tg6) harboring high levels of Epo in the brain and blood will also be improved compared with wild-type (WT) animals. Surprisingly, VAH was blunted in Tg6 female mice. To define whether this phenomenon had a central (brain stem respiratory centers) and/or peripheral (carotid bodies) origin, a bilateral transection of carotid sinus nerve (chemodenervation) was performed. This procedure allowed the analysis of the central response in the absence of carotid body information. Interestingly, chemodenervation restored the VAH in Tg6 mice, suggesting that carotid bodies were responsible for the blunted response. Coherently with this observation, the sensitivity to oxygen alteration in arterial blood (Dejour test) after chronic hypoxia was lower in transgenic carotid bodies compared with the WT control. As blunted VAH occurred in female but not male transgenic mice, the involvement of sex female steroids was obvious. Indeed, measurement of sexual female hormones revealed that the estradiol serum level was 4 times higher in transgenic mice Tg6 than in WT animals. While ovariectomy decreased VAH in WT females, this treatment restored VAH in Tg6 female mice. In line with this observation, injections of estradiol in ovariectomized Tg6 females dramatically reduced the VAH. We concluded that during chronic hypoxia, estradiol in carotid bodies suppresses the Epo-mediated elevation of ventilation. Considering the increased application of recombinant Epo for a variety of disorders, our data imply the need to take the patient's hormonal status into consideration.

Intestinal fungi contribute to development of alcoholic liver disease.

PubMed

Yang, An-Ming; Inamine, Tatsuo; Hochrath, Katrin; Chen, Peng; Wang, Lirui; Llorente, Cristina; Bluemel, Sena; Hartmann, Phillipp; Xu, Jun; Koyama, Yukinori; Kisseleva, Tatiana; Torralba, Manolito G; Moncera, Kelvin; Beeri, Karen; Chen, Chien-Sheng; Freese, Kim; Hellerbrand, Claus; Lee, Serene Ml; Hoffman, Hal M; Mehal, Wajahat Z; Garcia-Tsao, Guadalupe; Mutlu, Ece A; Keshavarzian, Ali; Brown, Gordon D; Ho, Samuel B; Bataller, Ramon; Stärkel, Peter; Fouts, Derrick E; Schnabl, Bernd

2017-06-30

Chronic liver disease with cirrhosis is the 12th leading cause of death in the United States, and alcoholic liver disease accounts for approximately half of all cirrhosis deaths. Chronic alcohol consumption is associated with intestinal bacterial dysbiosis, yet we understand little about the contribution of intestinal fungi, or mycobiota, to alcoholic liver disease. Here we have demonstrated that chronic alcohol administration increases mycobiota populations and translocation of fungal β-glucan into systemic circulation in mice. Treating mice with antifungal agents reduced intestinal fungal overgrowth, decreased β-glucan translocation, and ameliorated ethanol-induced liver disease. Using bone marrow chimeric mice, we found that β-glucan induces liver inflammation via the C-type lectin-like receptor CLEC7A on Kupffer cells and possibly other bone marrow-derived cells. Subsequent increases in IL-1β expression and secretion contributed to hepatocyte damage and promoted development of ethanol-induced liver disease. We observed that alcohol-dependent patients displayed reduced intestinal fungal diversity and Candida overgrowth. Compared with healthy individuals and patients with non-alcohol-related cirrhosis, alcoholic cirrhosis patients had increased systemic exposure and immune response to mycobiota. Moreover, the levels of extraintestinal exposure and immune response correlated with mortality. Thus, chronic alcohol consumption is associated with an altered mycobiota and translocation of fungal products. Manipulating the intestinal mycobiome might be an effective strategy for attenuating alcohol-related liver disease.

Chronic Cocaine Use Causes Changes in the Striatal Proteome Depending on the Endogenous Expression of Pleiotrophin.

PubMed

Vicente-Rodríguez, Marta; Herradón, Gonzalo; Ferrer-Alcón, Marcel; Uribarri, María; Pérez-García, Carmen

2015-07-20

The neurotrophic factor pleiotrophin (PTN) is upregulated in different brain areas after the administration of different drugs of abuse, including psychostimulants. PTN has been shown to prevent cocaine-induced cytotoxicity in NG108-15 and PC12 cells. We previously demonstrated that specific phosphoproteins related to neurodegeneration processes are differentially regulated in the mouse striatum by a single cocaine (15 mg/kg) administration depending on the endogenous expression of PTN. Since neurodegenerative processes are usually observed in patients exposed to toxicants for longer duration, we have now performed a striatal proteomic study using samples enriched in phosphorylated proteins from PTN knockout (PTN-/-) mice, from mice with transgenic PTN overexpression (PTN-Tg) in the brain, and from wild type (WT) mice after a chronic treatment with cocaine (15 mg/kg/day for 7 days). We have successfully identified 23 proteins significantly affected by chronic cocaine exposure, genotype, or both. Most of these proteins, including peroxiredoxin-6 (PRDX6), triosephosphate isomerase (TPI1), ubiquitin carboxyl-terminal hydrolase isozyme L1 (UCHL1), and annexins A5 (ANXA5) and A7 (ANXA7), may be of significant importance because they were previously identified in proteomic studies in animals treated with psychostimulants and/or because they are related to neurodegenerative disorders such as Parkinson's disease and Alzheimer's disease. The data support a protective role of PTN against chronic cocaine-induced neural alterations.

Chronic stress exacerbates tau pathology, neurodegeneration, and cognitive performance through a corticotropin-releasing factor receptor-dependent mechanism in a transgenic mouse model of tauopathy

PubMed Central

Carroll, Jenna C.; Iba, Michiyo; Bangasser, Debbie A.; Valentino, Rita J.; James, Michael J.; Brunden, Kurt R.; Lee, Virginia M.-Y.; Trojanowski, John Q.

2011-01-01

Since over-activation of the hypothalamic-pituitary-adrenal (HPA) axis occurs in Alzheimer’s disease (AD), dysregulation of stress neuromediators may play a mechanistic role in the pathophysiology of AD. However, the effects of stress on tau phosphorylation are poorly understood and the relationship between corticosterone and corticotropin-releasing factor (CRF) on both Aβ and tau pathology remain unclear. Therefore, we first established a model of chronic stress which exacerbates Aβ accumulation in Tg2576 mice and then extended this stress paradigm to a tau transgenic mouse model with the P301S mutation (PS19) which displays tau hyperphosphorylation, insoluble tau inclusions and neurodegeneration. We show for the first time that both Tg2576 and PS19 mice demonstrate a heightened HPA stress profile in the unstressed state. In Tg2576 mice, one month of restraint/isolation (RI) stress increased Aβ levels, suppressed microglial activation, and worsened spatial and fear memory compared to non-stressed mice. In PS19 mice, RI stress promoted tau hyperphosphorylation, insoluble tau aggregation, neurodegeneration and fear-memory impairments. These effects were not mimicked by chronic corticosterone administration but were prevented by pre-stress administration of a CRF receptor type 1 (CRF1) antagonist. The role for a CRF1-dependent mechanism was further supported by the finding that mice over-expressing CRF had increased hyperphosphorylated tau compared to wildtype littermates. Together, these results implicate HPA dysregulation in AD neuropathogenesis and suggest that prolonged stress may increase Aβ and tau hyperphosphorylation. These studies also implicate CRF in AD pathophysiology and suggest that pharmacological manipulation of this neuropeptide may be a potential therapeutic strategy for AD. PMID:21976528

Type III Neuregulin-1 is required for normal sensorimotor gating, memory related behaviors and cortico-striatal circuit components

PubMed Central

Chen, Ying-Jiun J.; Johnson, Madeleine A.; Lieberman, Michael D.; Goodchild, Rose E.; Schobel, Scott; Lewandowski, Nicole; Rosoklija, Gorazd; Liu, Ruei-Che; Gingrich, Jay A.; Small, Scott; Moore, Holly; Dwork, Andrew J.; Talmage, David A.; Role, Lorna W.

2008-01-01

Neuregulin-1 (Nrg1)/erbB signaling regulates neuronal development, migration, myelination, and synaptic maintenance. The Nrg1 gene is a schizophrenia susceptibility gene. To understand the contribution of Nrg1 signaling to adult brain structure and behaviors, we have studied the regulation of Type III Nrg1 expression and evaluated the effect of decreased expression of the Type III Nrg1 isoforms. Type III Nrg1 is transcribed by a promoter distinct from those for other Nrg1 isoforms and, in the adult brain, is expressed in the medial prefrontal cortex, ventral hippocampus and ventral subiculum, regions involved in the regulation of sensorimotor gating and short term memory. Adult heterozygous mutant mice with a targeted disruption for Type III Nrg1 (Nrg1tm1.1Lwr+/-) have enlarged lateral ventricles and decreased dendritic spine density on subicular pyramidal neurons. MRI imaging of Type III Nrg1 heterozygous mice revealed hypo-function in the medial prefrontal cortex and the hippocampal CA1 and subiculum regions. Type III Nrg1 heterozygous mice also have impaired performance on delayed alternation memory tasks, and deficits in prepulse inhibition (PPI). Chronic nicotine treatment eliminated differences in PPI between Type III Nrg1 heterozygous mice and their wild type littermates. Our findings demonstrate a role of Type III Nrg1-signaling in the maintenance of cortico-striatal components, and in the neural circuits involved in sensorimotor gating and short term memory. PMID:18596162

Nod2 deficiency protects mice from cholestatic liver disease by increasing renal excretion of bile acids

PubMed Central

Wang, Lirui; Hartmann, Phillipp; Haimerl, Michael; Bathena, Sai P.; Sjöwall, Christopher; Almer, Sven; Alnouti, Yazen; Hofmann, Alan F.; Schnabl, Bernd

2014-01-01

Background & aims Chronic liver disease is characterized by fibrosis that may progress to cirrhosis. Nucleotide oligomerization domain 2 (Nod2), a member of the Nod-like receptor (NLR) family of intracellular immune receptors, plays an important role in the defense against bacterial infection through binding to the ligand muramyl dipeptide (MDP). Here, we investigated the role of Nod2 in the development of liver fibrosis. Methods We studied experimental cholestatic liver disease induced by bile duct ligation or toxic liver disease induced by carbon tetrachloride in wild type and Nod2−/− mice. Results Nod2 deficiency protected mice from cholestatic but not toxin-induced liver injury and fibrosis. Most notably, the hepatic bile acid concentration was lower in Nod2−/− mice than wild type mice following bile duct ligation for 3 weeks. In contrast to wild type mice, Nod2−/− mice had increased urinary excretion of bile acids, including sulfated bile acids, and an upregulation of the bile acid efflux transporters MRP2 and MRP4 in tubular epithelial cells of the kidney. MRP2 and MRP4 were downregulated by IL-1β in a Nod2 dependent fashion. Conclusions Our findings indicate that Nod2 deficiency protects mice from cholestatic liver injury and fibrosis through enhancing renal excretion of bile acids that in turn contributes to decreased concentration of bile acids in the hepatocyte. PMID:24560660

Dietary fructose-induced hepatocellular carcinoma development manifested in mice lacking apoptosis inhibitor of macrophage (AIM).

PubMed

Ozawa, Takayuki; Maehara, Natsumi; Kai, Toshihiro; Arai, Satoko; Miyazaki, Toru

2016-12-01

The consumption of fructose, including the use of high-fructose corn syrup as a sweetener, has increased continuously in recent decades. Although the involvement of fructose in the development of metabolic diseases has been emphasized recently, whether fructose intake increases susceptibility to steatosis-associated hepatocellular carcinoma (HCC) is unclear. Here, we investigated this issue using mice lacking a circulating protein, apoptosis inhibitor of macrophage (AIM, encoded by cd5l). AIM does not induce carcinogenesis of hepatocytes, but provokes necrotic death specifically in AIM-bound cancer cells through complement cascade activation, thereby preventing HCC tumor development in wild-type mice. When subjected to a high-fructose diet (HFrD), AIM-deficient (AIM -/- ) mice showed liver steatosis and subsequent liver inflammation as well as fibrosis, but at much milder levels compared with mice fed a high-fat diet. However, AIM -/- mice were markedly susceptible to HCC tumor development, whereas no wild-type mice developed the disease. Systemic metabolic states, including obesity and insulin resistance, were similar in both types of mice after HFrD challenge, indicating no influence of AIM on HFrD-induced metabolic changes. Our results suggest that dietary fructose increases the risk for liver carcinogenesis and that individuals with low blood AIM levels may be susceptible to HCC under chronic fructose intake. © 2016 The Authors. Genes to Cells published by Molecular Biology Society of Japan and John Wiley & Sons Australia, Ltd.

Hypertension from chronic central sodium chloride in mice is mediated by the ouabain-binding site on the Na,K-ATPase α2-isoform

PubMed Central

Dostanic, Iva; Lingrel, Jerry B.; Hou, Xiaohong; Wu, Hengwei

2011-01-01

A chronic increase in the concentration of sodium chloride in the cerebrospinal fluid (CSF) (↑CSF [NaCl]) appears to be critically important for the development of salt-dependent hypertension. In agreement with this concept, increasing CSF [NaCl] chronically by intracerebroventricular (icv) infusion of NaCl-rich artificial CSF (aCSF-HiNaCl) in rats produces hypertension by the same mechanisms (i.e., aldosterone-ouabain pathway in the brain) as that produced by dietary sodium in salt-sensitive strains. We first demonstrate here that icv aCSF-HiNaCl for 10 days also causes hypertension in wild-type (WT) mice. We then used both WT and gene-targeted mice to explore the mechanisms. In WT mice with a ouabain-sensitive Na,K-ATPase α2-isoform (α2S/S), mean arterial pressure rose by ∼25 mmHg within 2 days of starting aCSF-HiNaCl (0.6 nmol Na/min) and remained elevated throughout the study. Ouabain (171 pmol/day icv) increased blood pressure to a similar extent. aCSF-HiNaCl or ouabain given at the same rates subcutaneously instead of intracerebroventricularly had no effect on blood pressure. The pressor response to icv aCSF-HiNaCl was abolished by an anti-ouabain antibody given intracerebroventricularly but not subcutaneously, indicating that it is mediated by an endogenous ouabain-like substance in the brain. We compared the effects of icv aCSF-HiNaCl or icv ouabain on blood pressure in α2S/S versus knockout/knockin mice with a ouabain-resistant endogenous α2-subunit (α2R/R). In α2R/R, there was no pressor response to icv aCSF-HiNaCl in contrast to WT mice. The α2R/R genotype also lacked a pressor response to icv ouabain. These data demonstrate that chronic ↑CSF [NaCl] causes hypertension in mice and that the blood pressure response is mediated by the ouabain-like substance in the brain, specifically by its binding to the α2-isoform of the Na,K-ATPase. PMID:21856907

Exposure to a Mycobacterial Antigen, ESAT-6, Exacerbates Granulomatous and Fibrotic Changes in a Multiwall Carbon Nanotube Model of Chronic Pulmonary Disease.

PubMed

Malur, Anagha; Barna, Barbara P; Patel, Janki; McPeek, Matthew; Wingard, Christopher J; Dobbs, Larry; Thomassen, Mary Jane

2015-12-01

Recent studies suggest additive effects of environmental pollutants and microbial antigens on respiratory disease. We established a granuloma model in which instilled multiwall carbon nanotubes (MWCNT) elicit granulomatous pathology. We hypothesized that mycobacterial antigen ESAT-6, a T cell activator associated with tuberculosis and sarcoidosis, might alter pathology. Wild-type C57Bl/6 mice received MWCNT with or without ESAT-6 peptide. Controls received vehicle (surfactant-PBS) or ESAT-6 alone. Mice were evaluated 60 days later for granulomas, fibrosis, and bronchoalveolar lavage (BAL) cell expression of inflammatory mediators (CCL2, MMP-12, and Osteopontin). Results indicated increased granulomas, fibrosis, and inflammatory mediators in mice receiving the combination of MWCNT+ESAT-6 compared to MWCNT or vehicle alone. ESAT-6 alone showed no significant effect on these pathological endpoints. However, CD3 (+) lymphocyte infiltration of lung tissue increased with MWCNT+ESAT-6 versus MWCNT alone. Findings suggest that concurrent exposure to microbial antigen and MWCNT exacerbates chronic pulmonary disease.

A study of hearing function and histopathologic changes in the cochlea of the type 2 diabetes model Tsumura Suzuki obese diabetes mouse.

PubMed

Tsuda, Junko; Sugahara, Kazuma; Hori, Takeshi; Kanagawa, Eiju; Takaki, Eiichi; Fujimoto, Mitsuaki; Nakai, Akira; Yamashita, Hiroshi

2016-11-01

This study used Tsumura Suzuki Obese Diabetes (TSOD) mice as a spontaneous type 2 diabetes model and Tsumura Suzuki Non-obesity (TSNO) mice as controls to investigate factors involved in the onset of hearing impairment. Body weight, blood glucose levels, and auditory brainstem responses (ABRs) were measured. The cochleae were excised and evaluated histopathologically. The TSOD mice showed significant hyperglycemia at 2-7 months and severe obesity at 5-10 months; significantly elevated ABR thresholds at 8-10 months; and the capillary lumens in the cochlea stria vascularis were narrower in the TSOD mice than in the TSNO mice. At 17 months, India ink vascular staining of the TSOD mice's cochleae revealed decreased capillary density in the stria vascularis. The vascular area of capillaries in the stria vascularis and the vascular area were significantly smaller in TSOD mice. Histopathological analysis showed vessel wall thickening in the modiolus and narrowed capillaries in the stria vascularis, suggesting reduced blood flow to the inner ear. The diabetes mice model used in our study showed early age-associated hearing loss, and histopathology showed findings of vessel wall thickening in the modiolus, narrowing of capillaries in the stria vascularis, and chronically reduced blood flow in the cochlea.

Absence of Wdr13 Gene Predisposes Mice to Mild Social Isolation – Chronic Stress, Leading to Depression-Like Phenotype Associated With Differential Expression of Synaptic Proteins

PubMed Central

Mitra, Shiladitya; Sameer Kumar, Ghantasala S.; Jyothi Lakshmi, B.; Thakur, Suman; Kumar, Satish

2018-01-01

We earlier reported that the male mice lacking the Wdr13 gene (Wdr13-/0) showed mild anxiety, better memory retention, and up-regulation of synaptic proteins in the hippocampus. With increasing evidences from parallel studies in our laboratory about the possible role of Wdr13 in stress response, we investigated its role in brain. We observed that Wdr13 transcript gets up-regulated in the hippocampus of the wild-type mice exposed to stress. To further dissect its function, we analyzed the behavioral and molecular phenotypes of Wdr13-/0 mice when subjected to mild chronic psychological stress, namely; mild (attenuated) social isolation. We employed iTRAQ based quantitative proteomics, real time PCR and western blotting to investigate molecular changes. Three weeks of social isolation predisposed Wdr13-/0 mice to anhedonia, heightened anxiety-measured by Open field test (OFT), increased behavior despair- measured by Forced swim test (FST) and reduced dendritic branching along with decreased spine density of hippocampal CA1 neurons as compared to wild-type counterparts. This depression-like-phenotype was however ameliorated when treated with anti-depressant imipramine. Molecular analysis revealed that out of 1002 quantified proteins [1% False discovery rate (FDR), at-least two unique peptides], strikingly, a significant proportion of synaptic proteins including, SYN1, CAMK2A, and RAB3A were down-regulated in the socially isolated Wdr13-/0 mice as compared to its wild-type counterparts. This was in contrast to the elevated levels of these proteins in non-stressed mutants as compared to the controls. We hypothesized that a de-regulated transcription factor upstream of the synaptic genes might be responsible for the observed phenotype. Indeed, in the socially isolated Wdr13-/0 mice, there was an up-regulation of GATA1 – a transcription factor that negatively regulates synaptic genes and has been associated with Major Depression (MD) in humans. The present study demonstrates significant genotype × enviornment interaction for Wdr13 gene as shown by the reversal in the expression levels of several synaptic proteins in the mutant vis-à-vis wild-type mouse when exposed to social isolation stress. PMID:29743870

Detection of genotoxic and non-genotoxic carcinogens in Xpc{sup −/−}p53{sup +/−} mice

DOE Office of Scientific and Technical Information (OSTI.GOV)

Melis, Joost P.M.; Leiden University Medical Center, Department of Toxicogenetics, Leiden; Speksnijder, Ewoud N.

2013-01-15

An accurate assessment of the carcinogenic potential of chemicals and pharmaceutical drugs is essential to protect humans and the environment. Therefore, substances are extensively tested before they are marketed to the public. Currently, the rodent two-year bioassay is still routinely used to assess the carcinogenic potential of substances. However, over time it has become clear that this assay yields false positive results and also has several economic and ethical drawbacks including the use of large numbers of animals, the long duration, and the high cost. The need for a suitable alternative assay is therefore high. Previously, we have proposed themore » Xpa*p53 mouse model as a very suitable alternative to the two-year bioassay. We now show that the Xpc*p53 mouse model preserves all the beneficial traits of the Xpa*p53 model for sub-chronic carcinogen identification and can identify both genotoxic and non-genotoxic carcinogens. Moreover, Xpc*p53 mice appear to be more responsive than Xpa*p53 mice towards several genotoxic and non-genotoxic carcinogens. Furthermore, Xpc*p53 mice are far less sensitive than Xpa*p53 mice for the toxic activity of DNA damaging agents and as such clearly respond in a similar way as wild type mice do. These advantageous traits of the Xpc*p53 model make it a better alternative for in vivo carcinogen testing than Xpa*p53. This pilot study suggests that Xpc*p53 mice are suited for routine sub-chronic testing of both genotoxic and non-genotoxic carcinogens and as such represent a suitable alternative to possibly replace the murine life time cancer bioassay. Highlights: ► The Xpc*p53 mouse model is able to identify genotoxic and non-genotoxic carcinogens. ► Time, animals and cost can be significantly reduced compared to the 2-year bioassay. ► Xpc*p53 mice are more advantageous for carcinogen identification than Xpa*p53 mice. ► Xpc*p53 mice exhibit a wild type response upon exposure to genotoxicants.« less

PKCepsilon overexpression, irrespective of genetic background, sensitizes skin to UVR-induced development of squamous-cell carcinomas.

PubMed

Sand, Jordan M; Aziz, Moammir H; Dreckschmidt, Nancy E; Havighurst, Thomas C; Kim, KyungMann; Oberley, Terry D; Verma, Ajit K

2010-01-01

Chronic exposure to UVR is the major etiologic factor in the development of human skin cancers including squamous-cell carcinoma (SCC). We have previously shown that protein Kinase C epsilon (PKCepsilon) transgenic mice on FVB/N background, which overexpress PKCepsilon protein approximately eightfold over endogenous levels in epidermis, exhibit about threefold more sensitivity than wild-type littermates to UVR-induced development of SCC. To determine whether it is PKCepsilon and not the mouse genetic background that determines susceptibility to UVR carcinogenesis, we cross-bred PKCepsilon FVB/N transgenic mice with SKH-1 hairless mice to generate PKCepsilon-overexpressing SKH-1 hairless mice. To evaluate the susceptibility of PKCepsilon SKH-1 hairless transgenic mice to UVR carcinogenesis, the mice were exposed to UVR (1-2 KJ m(-2)) three times weekly from a bank of six kodacel-filtered FS40 sunlamps. As compared with the wild-type hairless mice, PKCepsilon overexpression in SKH-1 hairless mice decreased the latency (12 weeks), whereas it increased the incidence (twofold) and multiplicity (fourfold) of SCC. The SKH hairless transgenic mice were observed to be as sensitive as FVB/N transgenic mice to UVR-induced development of SCC and expression of proliferative markers (proliferating cell nuclear antigen, signal transducers and activators of transcription 3, and extracellular signal-regulated kinase 1/2). The results indicate that PKCepsilon level dictates susceptibility, irrespective of genetic background, to UVR carcinogenesis.

Interferon-γ and Tumor Necrosis Factor-α Mediate the Upregulation of Indoleamine 2,3-Dioxygenase and the Induction of Depressive-Like Behavior in Mice in Response to Bacillus Calmette-Guérin

PubMed Central

O’Connor, Jason C.; André, Caroline; Wang, Yunxia; Lawson, Marcus A.; Szegedi, Sandra S.; Lestage, Jacques; Castanon, Nathalie; Kelley, Keith W.; Dantzer, Robert

2010-01-01

Although the tryptophan-degrading enzyme, indoleamine 2,3-dioxygenase (IDO), is a pivotal mediator of inflammation-induced depression, its mechanism of regulation has not yet been investigated in this context. Here, we demonstrate an essential role for interferon (IFN)γ and tumor necrosis factor (TNF)α in the induction of IDO and depressive-like behaviors in response to chronic immune activation. Wild-type (WT) control mice and IFNγR−/− mice were inoculated with an attenuated form of Mycobacterium bovis, bacille Calmette-Guérin (BCG). Infection with BCG induced an acute episode of sickness that was similar in WT and IFNγR−/− mice. Increased immobility during the forced swim and tail suspension tests occurred in WT mice 7 d after BCG inoculation but was entirely absent in IFNγR−/− mice. In WT mice, these indices of depressive-like behavior were associated with chronic upregulation of IFNγ, interleukin(IL)-1β, TNFα, and IDO. Proinflammatory cytokine expression was elevated in BCG-infected IFNγR−/− mice as well, but upregulation of lung and brain IDO mRNA was completely abolished. This was accompanied by an attenuation of BCG-induced TNFα mRNA and the lack of an increase in plasma kynurenine/tryptophan ratio in the BCG-inoculated IFNγR−/− mice compared with WT controls. Pretreatment of mice with the TNFα antagonist, etanercept, partially blunted BCG-induced IDO activation and depressive-like behavior. In accordance with these in vivo data, IFNγ and TNFα synergized to induce IDO in primary microglia. Together, these data demonstrate that IFNγ, with TNFα, is necessary for induction of IDO and depressive-like behavior in mice after BCG infection. PMID:19339614

Antinociceptive effects of fisetin against diabetic neuropathic pain in mice: Engagement of antioxidant mechanisms and spinal GABAA receptors.

PubMed

Zhao, Xin; Li, Xin-Lin; Liu, Xin; Wang, Chuang; Zhou, Dong-Sheng; Ma, Qing; Zhou, Wen-Hua; Hu, Zhen-Yu

2015-12-01

Peripheral painful neuropathy is one of the most common complications in diabetes and necessitates improved treatment. Fisetin, a naturally occurring flavonoid, has been reported to exert antidepressant-like effect in previous studies. As antidepressant drugs are employed clinically to treat neuropathic pain, this work aimed to investigate whether fisetin possess beneficial effect on diabetic neuropathic pain and explore the mechanism(s). We subjected mice to diabetes by a single intraperitoneal (i.p.) injection of streptozotocin (200mg/kg), and von Frey test or Hargreaves test was used to assess mechanical allodynia or thermal hyperalgesia, respectively. Chronic treatment of diabetic mice with fisetin not only ameliorated the established symptoms of thermal hyperalgesia and mechanical allodynia, but also arrested the development of neuropathic pain when given at low doses. Although chronic fisetin administration did not impact on the symptom of hyperglycemia in diabetic mice, it reduced exacerbated oxidative stress in tissues of spinal cord, dorsal root ganglion (DRG) and sciatic verve. Furthermore, the analgesic actions of fisetin were abolished by repetitive co-treatment with the reactive oxygen species (ROS) donor tert-butyl hydroperoxide (t-BOOH), but potentiated by the ROS scavenger phenyl-N-tert-butylnitrone (PBN). Finally, acute blockade of spinal GABAA receptors by bicuculline totally counteracted such fisetin analgesia. These findings indicate that chronic fisetin treatment can delay or correct neuropathic hyperalgesia and allodynia in mice with type 1 diabetes. Mechanistically, the present fisetin analgesia may be associated with its antioxidant activity, and spinal GABAA receptors are likely rendered as downstream targets. Copyright © 2015 Elsevier Ltd. All rights reserved.

Antibody targeting KIT as pretransplantation conditioning in immunocompetent mice.

PubMed

Xue, Xingkui; Pech, Nancy K; Shelley, W Christopher; Srour, Edward F; Yoder, Mervin C; Dinauer, Mary C

2010-12-09

Inherited hematologic defects that lack an in vivo selective advantage following gene correction may benefit from effective yet minimally toxic cytoreduction of endogenous hematopoietic stem cells (HSCs) prior to transplantation of gene-modified HSCs. We studied the efficacy of administering a novel sequential treatment of parenteral ACK2, an antibody that blocks KIT, followed by low-dose irradiation (LD-IR) for conditioning of wild-type and X-linked chronic granulomatous disease (X-CGD) mice. In wild-type mice, combining ACK2 and LD-IR profoundly decreased endogenous competitive long-term HSC repopulating activity, and permitted efficient and durable donor-derived HSC engraftment after congenic transplantation. ACK2 alone was ineffective. The combination of ACK2 and LD-IR was also effective conditioning in X-CGD mice for engraftment of X-CGD donor HSCs transduced ex vivo with a lentiviral vector. We conclude that combining ACK2 with LD-IR is a promising approach to effectively deplete endogenous HSCs and facilitate engraftment of transplanted donor HSCs.

Diabetes accelerates retinal ganglion cell dysfunction in mice lacking sigma receptor 1

PubMed Central

Ha, Yonju; Saul, Alan; Tawfik, Amany; Zorrilla, Eric P.; Ganapathy, Vadivel

2012-01-01

Purpose Sigma receptor 1 (σR1) is a non-opioid transmembrane protein that may act as a molecular chaperone at the endoplasmic reticulum–mitochondrial membrane. Ligands for σR1, such as (+)-pentazocine [(+)-PTZ], confer marked retinal neuroprotection in vivo and in vitro. Recently we analyzed the retinal phenotype of mice lacking σR1 (σR1 KO) and observed normal retinal morphology and function in young mice (5–30 weeks) but diminished negative scotopic threshold responses (nSTRs), retinal ganglion cell (RGC) loss, and disruption of optic nerve axons consistent with inner retinal dysfunction by 1 year. These data led us to test the hypothesis that σR1 may be critical in forestalling chronic retinal stress; diabetes was used as the model of chronic stress. Methods To determine whether σR1 is required for (+)-PTZ neuroprotective effects, primary RGCs isolated from wild-type (WT) and σR1 KO mice were exposed to xanthine–xanthine oxidase (10 µM:2 mU/ml) to induce oxidative stress in the presence or absence of (+)-PTZ. Cell death was evaluated by terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) analysis. To assess effects of chronic stress on RGC function, diabetes was induced in 3-week C57BL/6 (WT) and σR1 KO mice, using streptozotocin to yield four groups: WT nondiabetic (WT non-DB), WT diabetic (WT-DB), σR1 KO non-DB, and σR1 KO-DB. After 12 weeks of diabetes, when mice were 15-weeks old, intraocular pressure (IOP) was recorded, electrophysiologic testing was performed (including detection of nSTRs), and the number of RGCs was counted in retinal histological sections. Results In vitro studies showed that (+)-PTZ could not prevent oxidative stress-induced death of RGCs harvested from σR1 KO mice but afforded robust protection against death of RGCs harvested from WT mice. In the studies of chronic stress induced by diabetes, the IOP measured in the four mouse groups was within the normal range; however, there was a significant increase in the IOP of σR1 KO-DB mice (16±0.5 mmHg) compared to the other groups tested (σR1 KO non-DB, WT non-DB, WT-DB: ~12±0.6 mmHg). Regarding electrophysiologic testing, the nSTRs of σR1 KO non-DB mice were similar to WT non-DB mice at 15 weeks; however, they were significantly lower in σR1 KO-DB mice (5±1 µV) compared to the other groups, including, notably, σR1 KO-nonDB (12±2 µV). As expected, the number of RGCs in σR1 KO non-DB mice was similar to WT non-DB mice at 15 weeks, but under chronic stress of diabetes there were fewer RGCs in retinas of σR1 KO-DB mice. Conclusions This is the first report showing unequivocally that the neuroprotective effects of (+)-PTZ require σR1. σR1 KO mice show normal retinal structure and function at young ages; however, when subjected to the chronic stress of diabetes, there is an acceleration of retinal functional deficits in σR1 KO mice such that ganglion cell dysfunction is observed at a much earlier age than nondiabetic σR1 KO mice. The data support the hypothesis that σR1 plays a key role in modulating retinal stress and may be an important target for retinal disease. PMID:23233788

Chronic, not acute, skin-specific inflammation promotes thrombosis in psoriasis murine models.

PubMed

Golden, Jackelyn B; Wang, Yunmei; Fritz, Yi; Diaconu, Doina; Zhang, Xiufen; Debanne, Sara M; Simon, Daniel I; McCormick, Thomas S; Ward, Nicole L

2015-12-16

Psoriasis patients exhibit an increased risk of atherothrombotic events, including myocardial infarction and stroke. Clinical evidence suggests that psoriasis patients with early onset and more severe disease have the highest risk for these co-morbidities, perhaps due to the extent of body surface involvement, subsequent levels of systemic inflammation, or chronicity of disease. We sought to determine whether acute or chronic skin-specific inflammation was sufficient to promote thrombosis. We used two experimental mouse models of skin-specific inflammation generated in either an acute (topical Aldara application onto wild-type C57Bl/6 mice for 5 days) or chronic (a genetically engineered K5-IL-17C mouse model of psoriasiform skin inflammation) manner. Arterial thrombosis was induced using carotid artery photochemical injury (Rose Bengal-green light laser) and carotid artery diameters were measured post-clot formation. We also examined measures of clot formation including prothrombin (PT) and activated partial thromboplastin time (aPTT). Skin inflammation was examined histologically and we profiled plasma-derived lipids. The number of skin-draining lymph-node (SDLN) and splenic derived CD11b(+)Ly6C(high) pro-inflammatory monocytes and CD11b(+)Ly6G(+) neutrophils was quantified using multi-color flow cytometry. Mice treated with topical Aldara for 5 days had similar carotid artery thrombotic occlusion times to mice treated with vehicle cream (32.2 ± 3.0 vs. 31.4 ± 2.5 min, p = 0.97); in contrast, K5-IL-17C mice had accelerated occlusion times compared to littermate controls (15.7 ± 2.1 vs. 26.5 ± 3.5 min, p < 0.01) while carotid artery diameters were similar between all mice. Acanthosis, a surrogate measure of inflammation, was increased in both Aldara-treated and K5-IL-17C mice compared to their respective controls. Monocytosis, defined as elevated SDLN and/or splenic CD11b(+)Ly6C(high) cells, was significantly increased in both Aldara-treated (SDLN: 3.8-fold, p = 0.02; spleen: 2.0-fold, p < 0.01) and K5-IL-17C (SDLN: 3.4-fold, p = 0.02; spleen: 3.5-fold, p < 0.01) animals compared to controls while neutrophilia, defined as elevated SDLN and/or splenic CD11b(+)Ly6G(+) cells, was significantly increased in only the chronic K5-IL-17C model (SDLN: 11.6-fold, p = 0.02; spleen: 11.3-fold, p < 0.01). Plasma-derived lipid levels, PT and aPTT times showed no difference between the Aldara-treated mice or the K5-IL-17C mice and their respective controls. Chronic, but not acute, skin-specific inflammation was associated with faster arterial thrombotic occlusion. Increased numbers of splenic and SDLN monocytes were observed in both acute and chronic skin-specific inflammation, however, increased splenic and SDLN neutrophils were observed only in the chronic skin-specific inflammation model. Understanding the cellular response to skin-specific inflammation may provide insights into the cellular participants mediating the pathophysiology of major adverse cardiovascular events associated with psoriasis.

High fat diet-induced diabetes in mice exacerbates cognitive deficit due to chronic hypoperfusion

PubMed Central

Zuloaga, Kristen L; Johnson, Lance A; Roese, Natalie E; Marzulla, Tessa; Zhang, Wenri; Nie, Xiao; Alkayed, Farah N; Hong, Christine; Grafe, Marjorie R; Pike, Martin M; Raber, Jacob

2015-01-01

Diabetes causes endothelial dysfunction and increases the risk of vascular cognitive impairment. However, it is unknown whether diabetes causes cognitive impairment due to reductions in cerebral blood flow or through independent effects on neuronal function and cognition. We addressed this using right unilateral common carotid artery occlusion to model vascular cognitive impairment and long-term high-fat diet to model type 2 diabetes in mice. Cognition was assessed using novel object recognition task, Morris water maze, and contextual and cued fear conditioning. Cerebral blood flow was assessed using arterial spin labeling magnetic resonance imaging. Vascular cognitive impairment mice showed cognitive deficit in the novel object recognition task, decreased cerebral blood flow in the right hemisphere, and increased glial activation in white matter and hippocampus. Mice fed a high-fat diet displayed deficits in the novel object recognition task, Morris water maze and fear conditioning tasks and neuronal loss, but no impairments in cerebral blood flow. Compared to vascular cognitive impairment mice fed a low fat diet, vascular cognitive impairment mice fed a high-fat diet exhibited reduced cued fear memory, increased deficit in the Morris water maze, neuronal loss, glial activation, and global decrease in cerebral blood flow. We conclude that high-fat diet and chronic hypoperfusion impair cognitive function by different mechanisms, although they share commons features, and that high-fat diet exacerbates vascular cognitive impairment pathology. PMID:26661233

Increased anxiety, voluntary alcohol consumption and ethanol-induced place preference in mice following chronic psychosocial stress.

PubMed

Bahi, Amine

2013-07-01

Stress exposure is known to be a risk factor for alcohol use and anxiety disorders. Comorbid chronic stress and alcohol dependence may lead to a complicated and potentially severe treatment profile. To gain an understanding of the interaction between chronic psychosocial stress and drug exposure, we studied the effects of concomitant chronic stress exposure on alcohol reward using two-bottle choice and ethanol-conditioned place preference (CPP). The study consisted of exposure of the chronic subordinate colony (CSC) mice "intruders" to an aggressive "resident" mouse for 19 consecutive days. Control mice were single housed (SHC). Ethanol consumption using two-bottle choice paradigm and ethanol CPP acquisition was assessed at the end of this time period. As expected, CSC exposure increased anxiety-like behavior and reduced weight gain as compared to SHC controls. Importantly, in the two-bottle choice procedure, CSC mice showed higher alcohol intake than SHC. When testing their response to ethanol-induced CPP, CSC mice achieved higher preference for the ethanol-paired chamber. In fact, CSC exposure increased ethanol-CPP acquisition. Taken together, these data demonstrate the long-term consequences of chronic psychosocial stress on alcohol intake in male mice, suggesting chronic stress as a risk factor for developing alcohol consumption and/or anxiety disorders.

Enhanced Phospholipase A2 Group 3 Expression by Oxidative Stress Decreases the Insulin-Degrading Enzyme

PubMed Central

Yui, Daishi; Nishida, Yoichiro; Nishina, Tomoko; Mogushi, Kaoru; Tajiri, Mio; Ishibashi, Satoru; Ajioka, Itsuki; Ishikawa, Kinya; Mizusawa, Hidehiro; Murayama, Shigeo; Yokota, Takanori

2015-01-01

Oxidative stress has a ubiquitous role in neurodegenerative diseases and oxidative damage in specific regions of the brain is associated with selective neurodegeneration. We previously reported that Alzheimer disease (AD) model mice showed decreased insulin-degrading enzyme (IDE) levels in the cerebrum and accelerated phenotypic features of AD when crossbred with alpha-tocopherol transfer protein knockout (Ttpa -/-) mice. To further investigate the role of chronic oxidative stress in AD pathophysiology, we performed DNA microarray analysis using young and aged wild-type mice and aged Ttpa -/- mice. Among the genes whose expression changed dramatically was Phospholipase A2 group 3 (Pla2g3); Pla2g3 was identified because of its expression profile of cerebral specific up-regulation by chronic oxidative stress in silico and in aged Ttpa -/- mice. Immunohistochemical studies also demonstrated that human astrocytic Pla2g3 expression was significantly increased in human AD brains compared with control brains. Moreover, transfection of HEK293 cells with human Pla2g3 decreased endogenous IDE expression in a dose-dependent manner. Our findings show a key role of Pla2g3 on the reduction of IDE, and suggest that cerebrum specific increase of Pla2g3 is involved in the initiation and/or progression of AD. PMID:26637123

Long-term obestatin treatment of mice type 2 diabetes increases insulin sensitivity and improves liver function.

PubMed

Kołodziejski, Paweł A; Pruszyńska-Oszmałek, Ewa; Strowski, Mathias Z; Nowak, Krzysztof W

2017-06-01

Obestatin and ghrelin are peptides encoded by the preproghrelin gene. Obestatin inhibits food intake, in addition to regulation of glucose and lipid metabolism. Here, we test the ability of obestatin at improving metabolic control and liver function in type 2 diabetic animals (type 2 diabetes mellitus). The effects of chronic obestatin treatment of mice with experimentally induced type 2 diabetes mellitus on serum levels of glucose and lipids, and insulin sensitivity are characterized. In addition, alterations of hepatic lipid and glycogen contents are evaluated. Obestatin reduced body weight and decreased serum glucose, fructosamine, and β-hydroxybutyrate levels, as well as total and low-density lipoprotein fractions of cholesterol. In addition, obestatin increased high-density lipoproteins cholesterol levels and enhanced insulin sensitivity in mice with type 2 diabetes mellitus. Moreover, obestatin diminished liver mass, hepatic triglycerides and cholesterol contents, while glycogen content was higher in livers of healthy and mice with type 2 diabetes mellitus treated with obestatin. These changes were accompanied by reduction of increased alanine aminotransferase, aspartate aminotransferase, and gamma glutamyl transpeptidase in T2DM mice with type 2 diabetes mellitus. Obestatin increased adiponectin levels and reduced leptin concentration. Obestatin influenced the expression of genes involved in lipid and carbohydrate metabolism by increasing Fabp5 and decreasing G6pc, Pepck, Fgf21 mRNA in the liver. Obestatin increased both, AKT and AMPK phosphorylation, and sirtuin 1 (SIRT1) protein levels as well as mRNA expression in the liver. Obestatin improves metabolic abnormalities in type 2 diabetes mellitus, restores hepatic lipid contents and decreases hepatic enzymes. Therefore, obestatin could potentially have a therapeutic relevance in treating of insulin resistance and metabolic dysfunctions in type 2 diabetes mellitus.

Leptin deficiency-induced obesity exacerbates ultraviolet B radiation-induced cyclooxygenase-2 expression and cell survival signals in ultraviolet B-irradiated mouse skin

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sharma, Som D.; Katiyar, Santosh K., E-mail: skatiyar@uab.ed; Department of Dermatology, University of Alabama at Birmingham, Birmingham, AL 35294

Obesity has been implicated in several inflammatory diseases and in different types of cancer. Chronic inflammation induced by exposure to ultraviolet (UV) radiation has been implicated in various skin diseases, including melanoma and nonmelanoma skin cancers. As the relationship between obesity and susceptibility to UV radiation-caused inflammation is not clearly understood, we assessed the role of obesity on UVB-induced inflammation, and mediators of this inflammatory response, using the genetically obese (leptin-deficient) mouse model. Leptin-deficient obese (ob/ob) mice and wild-type counterparts (C57/BL6 mice) were exposed to UVB radiation (120 mJ/cm{sup 2}) on alternate days for 1 month. The mice were thenmore » euthanized and skin samples collected for analysis of biomarkers of inflammatory responses using immunohistochemistry, western blotting, ELISA and real-time PCR. Here, we report that the levels of inflammatory responses were higher in the UVB-exposed skin of the ob/ob obese mice than those in the UVB-exposed skin of the wild-type non-obese mice. The levels of UVB-induced cyclooxygenase-2 expression, prostaglandin-E{sub 2} production, proinflammatory cytokines (i.e., tumor necrosis factor-alpha, interleukin-1beta, interleukin-6), and proliferating cell nuclear antigen and cell survival signals (phosphatidylinositol-3-kinase and p-Akt-Ser{sup 473}) were higher in the skin of the ob/ob obese mice than the those in skin of their wild-type non-obese counterparts. Compared with the wild-type non-obese mice, the leptin-deficient obese mice also exhibited greater activation of NF-kappaB/p65 and fewer apoptotic cells in the UVB-irradiated skin. Our study suggests for the first time that obesity in mice is associated with greater susceptibility to UVB-induced inflammatory responses and, therefore, obesity may increase susceptibility to UVB-induced inflammation-associated skin diseases, including the risk of skin cancer.« less

The Fate of Nephrons in Congenital Obstructive Nephropathy: Adult Recovery is Limited by Nephron Number Despite Early Release of Obstruction.

PubMed

Sergio, Maria; Galarreta, Carolina I; Thornhill, Barbara A; Forbes, Michael S; Chevalier, Robert L

2015-11-01

Urinary tract obstruction and reduced nephron number often occur together as a result of maldevelopment of the kidneys and the urinary tract. We determined the role of nephron number on adaptation of the remaining nephrons of mice subjected to neonatal partial unilateral ureteral obstruction followed through adulthood. Wild-type and Os/+ mice (the latter with 50% fewer nephrons) underwent sham operation or partial unilateral ureteral obstruction in the first 2 days of life. Additional mice underwent release of unilateral ureteral obstruction at 7 days. All kidneys were harvested at 3 weeks (weaning) or 6 weeks (adulthood). Glomerular number and area, glomerulotubular junction integrity, proximal tubular volume fraction and interstitial fibrosis were measured by histomorphometry. In the obstructed kidney unilateral ureteral obstruction caused additional nephron loss in Os/+ but not in wild-type mice. Glomerular growth from 3 to 6 weeks was impaired by ipsilateral obstruction and not preserved by release in wild-type or Os/+ mice. Proximal tubular growth was impaired and interstitial collagen was increased by ipsilateral obstruction in all mice. These conditions were attenuated by release of unilateral ureteral obstruction in wild-type mice but were not restored in Os/+ mice. Unilateral ureteral obstruction increased interstitial collagen in the contralateral kidney while release of obstruction enhanced tubular growth and reduced interstitial collagen. Unilateral ureteral obstruction in early postnatal development impairs adaptation to reduced nephron number and induces additional nephron loss despite release of obstruction. Premature and low birth weight infants with congenital obstructive nephropathy are likely at increased risk for progression of chronic kidney disease. Copyright © 2015 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

Development of chronic colitis is dependent on the cytokine MIF.

PubMed

de Jong, Y P; Abadia-Molina, A C; Satoskar, A R; Clarke, K; Rietdijk, S T; Faubion, W A; Mizoguchi, E; Metz, C N; Alsahli, M; ten Hove, T; Keates, A C; Lubetsky, J B; Farrell, R J; Michetti, P; van Deventer, S J; Lolis, E; David, J R; Bhan, A K; Terhorst, C; Sahli, M A

2001-11-01

The cytokine macrophage-migration inhibitory factor (MIF) is secreted by a number of cell types upon induction by lipopolysaccharide (LPS). Because colitis is dependent on interplay between the mucosal immune system and intestinal bacteria, we investigated the role of MIF in experimental colitis. MIF-deficient mice failed to develop disease, but reconstitution of MIF-deficient mice with wild-type innate immune cells restored colitis. In addition, established colitis could be treated with anti-MIF immunoglobulins. Thus, murine colitis is dependent on continuous MIF production by the innate immune system. Because we found increased plasma MIF concentrations in patients with Crohn's disease, these data suggested that MIF is a new target for intervention in Crohn's disease.

Effects of Gabra2 Point Mutations on Alcohol Intake: Increased Binge-Like and Blunted Chronic Drinking by Mice.

PubMed

Newman, Emily L; Gunner, Georgia; Huynh, Polly; Gachette, Darrel; Moss, Stephen J; Smart, Trevor G; Rudolph, Uwe; DeBold, Joseph F; Miczek, Klaus A

2016-11-01

Alcohol use disorders are associated with single-nucleotide polymorphisms in GABRA2, the gene encoding the GABA A receptor α2-subunit in humans. Deficient GABAergic functioning is linked to impulse control disorders, intermittent explosive disorder, and to drug abuse and dependence, yet it remains unclear whether α2-containing GABA A receptor sensitivity to endogenous ligands is involved in excessive alcohol drinking. Male wild-type (Wt) C57BL/6J and point-mutated mice rendered insensitive to GABAergic modulation by benzodiazepines (BZD; H101R), allopregnanolone (ALLO) or tetrahydrodeoxycorticosterone (THDOC; Q241M), or high concentrations of ethanol (EtOH) (S270H/L277A) at α2-containing GABA A receptors were assessed for their binge-like, moderate, or escalated chronic drinking using drinking in the dark, continuous access (CA) and intermittent access (IA) to alcohol protocols, respectively. Social approach by mutant and Wt mice in forced alcohol abstinence was compared to approach by EtOH-naïve controls. Social deficits in forced abstinence were treated with allopregnanolone (0, 3.0, 10.0 mg/kg, intraperitoneal [i.p.]) or midazolam (0, 0.56, 1.0 mg/kg, i.p.). Mice with BZD-insensitive α2-containing GABA A receptors (H101R) escalated their binge-like drinking. Mutants harboring the Q241M point substitution in Gabra2 showed blunted chronic intake in the CA and IA protocols. S270H/L277A mutants consumed excessive amounts of alcohol but, unlike wild-types, they did not show forced abstinence-induced social deficits. These findings suggest a role for: (i) H101 in species-typical binge-like drinking, (ii) Q241 in escalated chronic drinking, and (iii) S270 and/or L277 in the development of forced abstinence-associated social deficits. Clinical findings report reduced BZD-binding sites in the cortex of dependent patients; the present findings suggest a specific role for BZD-sensitive α2-containing receptors. In addition, amino acid residue 241 in Gabra2 is necessary for positive modulation and activation of GABA A receptors by ALLO and THDOC; we postulate that neurosteroid action on α2-containing receptor may be necessary for escalated chronic EtOH intake. Copyright © 2016 by the Research Society on Alcoholism.

Inflammation has a role in urethane‑induced lung cancer in C57BL/6J mice.

PubMed

Xu, Cai; Zhou, Lingyu; Lu, Lei; Chen, Ting; Wei, Siyu; Lin, Xiaojing; Lian, Xuemei

2016-10-01

Lung cancer is a common and highly frequent cause of cancer‑associated mortality worldwide. Several studies have indicated that chronic inflammation is associated with an increased risk of several types of human cancer. The lung is vulnerable to various chemical and biological insults, and persistent exposure to these factors may result in the release of several inflammatory cytokines from inflammatory cells, thus leading to chronic inflammation and a risk of lung cancer. Due to the extensive application of C57BL/6J mice in lipid metabolism‑related research, it appears important to establish a lung cancer model based on C57BL/6J mice. Therefore, the present study designed an experimental model, in which C57BL/6J mice received several injections of urethane. The study aimed to explore whether inflammation has a role in this model of lung cancer. The results demonstrated that 10 weekly intraperitoneal injections of urethane induced a 100% lung tumor incidence, and urethane‑treated mice possessed higher numbers of immune cells. In addition, the expression levels of cytokines and chemokines in bronchoalveolar lavage fluid were significantly different between the two groups. Activation of the transcription factor nuclear factor‑κB was increased in the lung tissues of urethane‑treated mice, and its expression was upregulated in a time‑dependent manner. These results suggested that the accumulation of lung inflammation may be associated with the occurrence of lung cancer in C57BL/6J mice.

Angiotensin II receptor blocker telmisartan enhances running endurance of skeletal muscle through activation of the PPAR-δ/AMPK pathway

PubMed Central

Feng, Xiaoli; Luo, Zhidan; Ma, Liqun; Ma, Shuangtao; Yang, Dachun; Zhao, Zhigang; Yan, Zhencheng; He, Hongbo; Cao, Tingbing; Liu, Daoyan; Zhu, Zhiming

2011-01-01

Abstract Clinical trials have shown that angiotensin II receptor blockers reduce the new onset of diabetes in hypertensives; however, the underlying mechanisms remain unknown. We investigated the effects of telmisartan on peroxisome proliferator activated receptor γ (PPAR-δ) and the adenosine monophosphate (AMP)-activated protein kinase (AMPK) pathway in cultured myotubes, as well as on the running endurance of wild-type and PPAR-δ-deficient mice. Administration of telmisartan up-regulated levels of PPAR-δ and phospho-AMPKα in cultured myotubes. However, PPAR-δ gene deficiency completely abolished the telmisartan effect on phospho-AMPKαin vitro. Chronic administration of telmisartan remarkably prevented weight gain, enhanced running endurance and post-exercise oxygen consumption, and increased slow-twitch skeletal muscle fibres in wild-type mice, but these effects were absent in PPAR-δ-deficient mice. The mechanism is involved in PPAR-δ-mediated stimulation of the AMPK pathway. Compared to the control mice, phospho-AMPKα level in skeletal muscle was up-regulated in mice treated with telmisartan. In contrast, phospho-AMPKα expression in skeletal muscle was unchanged in PPAR-δ-deficient mice treated with telmisartan. These findings highlight the ability of telmisartan to improve skeletal muscle function, and they implicate PPAR-δ as a potential therapeutic target for the prevention of type 2 diabetes. PMID:20477906

Restoration of the type I IFN-IL-1 balance through targeted blockade of PTGER4 inhibits autoimmunity in NOD mice.

PubMed

Rahman, M Jubayer; Rodrigues, Kameron B; Quiel, Juan A; Liu, Yi; Bhargava, Vipul; Zhao, Yongge; Hotta-Iwamura, Chie; Shih, Han-Yu; Lau-Kilby, Annie W; Malloy, Allison Mw; Thoner, Timothy W; Tarbell, Kristin V

2018-02-08

Type I IFN (IFN-I) dysregulation contributes to type 1 diabetes (T1D) development, and although increased IFN-I signals are pathogenic at the initiation of autoimmune diabetes, IFN-I dysregulation at later pathogenic stages more relevant for therapeutic intervention is not well understood. We discovered that 5 key antigen-presenting cell subsets from adult prediabetic NOD mice have reduced responsiveness to IFN-I that is dominated by a decrease in the tonic-sensitive subset of IFN-I response genes. Blockade of IFNAR1 in prediabetic NOD mice accelerated diabetes and increased Th1 responses. Therefore, IFN-I responses shift from pathogenic to protective as autoimmunity progresses, consistent with chronic IFN-I exposure. In contrast, IL-1-associated inflammatory pathways were elevated in prediabetic mice. These changes correlated with human T1D onset-associated gene expression. Prostaglandin E2 (PGE2) and prostaglandin receptor 4 (PTGER4), a receptor for PGE2 that mediates both inflammatory and regulatory eicosanoid signaling, were higher in NOD mice and drive innate immune dysregulation. Treating prediabetic NOD mice with a PTGER4 antagonist restored IFNAR signaling, decreased IL-1 signaling, and decreased infiltration of leukocytes into the islets. Therefore, innate cytokine alterations contribute to both T1D-associated inflammation and autoimmune pathogenesis. Modulating innate immune balance via signals such as PTGER4 may contribute to treatments for autoimmunity.

Attitudes toward the use of animals in chronic versus acute pain research: results of a web-based forum.

PubMed

Ormandy, Elisabeth H; Griffin, Gilly

2016-09-01

When asked about the use of animals in biomedical research, people often state that the research is only acceptable if pain and distress are minimised. However, pain is caused when the aim is to study pain itself, resulting in unalleviated pain for many of the animals involved. Consequently, the use of animals in pain research is often considered contentious. To date, no research has explored people's views toward different types of animal-based pain research (e.g. chronic or acute pain). This study used a web-based survey to explore people's willingness to support the use of mice in chronic versus acute pain research. The majority of the participants opposed the use of mice for either chronic (68.3%) or acute (63.1%) pain research. There was no difference in the levels of support or opposition for chronic versus acute pain research. Unsupportive participants justified their opposition by focusing on the perceived lack of scientific merit, or the existence of non-animal alternatives. Supporters emphasised the potential benefits that could arise, with some stating that the benefits outweigh the costs. The majority of the participants were opposed to pain research involving mice, regardless of the nature and duration of the pain inflicted, or the perceived benefit of the research. A better understanding of public views toward animal use in pain research may provide a stronger foundation for the development of policy governing the use of animals in research where animals are likely to experience unalleviated pain. 2016 FRAME.

Time-dependent effects of CX3CR1 in a mouse model of mild traumatic brain injury.

PubMed

Febinger, Heidi Y; Thomasy, Hannah E; Pavlova, Maria N; Ringgold, Kristyn M; Barf, Paulien R; George, Amrita M; Grillo, Jenna N; Bachstetter, Adam D; Garcia, Jenny A; Cardona, Astrid E; Opp, Mark R; Gemma, Carmelina

2015-09-02

Neuroinflammation is an important secondary mechanism that is a key mediator of the long-term consequences of neuronal injury that occur in traumatic brain injury (TBI). Microglia are highly plastic cells with dual roles in neuronal injury and recovery. Recent studies suggest that the chemokine fractalkine (CX3CL1, FKN) mediates neural/microglial interactions via its sole receptor CX3CR1. CX3CL1/CX3CR1 signaling modulates microglia activation, and depending upon the type and time of injury, either protects or exacerbates neurological diseases. In this study, mice deficient in CX3CR1 were subjected to mild controlled cortical impact injury (CCI), a model of TBI. We evaluated the effects of genetic deletion of CX3CR1 on histopathology, cell death/survival, microglia activation, and cognitive function for 30 days post-injury. During the acute post-injury period (24 h-15 days), motor deficits, cell death, and neuronal cell loss were more profound in injured wild-type than in CX3CR1(-/-) mice. In contrast, during the chronic period of 30 days post-TBI, injured CX3CR1(-/-) mice exhibited greater cognitive dysfunction and increased neuronal death than wild-type mice. The protective and deleterious effects of CX3CR1 were associated with changes in microglia phenotypes; during the acute phase CX3CR1(-/-) mice showed a predominant anti-inflammatory M2 microglial response, with increased expression of Ym1, CD206, and TGFβ. In contrast, increased M1 phenotypic microglia markers, Marco, and CD68 were predominant at 30 days post-TBI. Collectively, these novel data demonstrate a time-dependent role for CX3CL1/CX3CR1 signaling after TBI and suggest that the acute and chronic responses to mild TBI are modulated in part by distinct microglia phenotypes.

Chronic administration of DSP-7238, a novel, potent, specific and substrate-selective DPP IV inhibitor, improves glycaemic control and beta-cell damage in diabetic mice.

PubMed

Furuta, Y; Horiguchi, M; Sugaru, E; Ono-Kishino, M; Otani, M; Sakai, M; Masui, Y; Tsuchida, A; Sato, Y; Takubo, K; Hochigai, H; Kimura, H; Nakahira, H; Nakagawa, T; Taiji, M

2010-05-01

The purpose of this study is to assess the in vitro enzyme inhibition profile of DSP-7238, a novel non-cyanopyrrolidine dipeptidyl peptidase (DPP) IV inhibitor and to evaluate the acute and chronic effects of this compound on glucose metabolism in two different mouse models of type 2 diabetes. The in vitro enzyme inhibition profile of DSP-7238 was assessed using plasma and recombinant enzymes including DPP IV, DPP II, DPP8, DPP9 and fibroblast activation protein alpha (FAPalpha) with fluorogenic substrates. The inhibition type was evaluated based on the Lineweaver-Burk plot. Substrate selectivity of DSP-7238 and comparator DPP IV inhibitors (vildagliptin, sitagliptin, saxagliptin and linagliptin) was evaluated by mass spectrometry based on the changes in molecular weight of peptide substrates caused by release of N-terminal dipeptides. In the in vivo experiments, high-fat diet-induced obese (DIO) mice were subjected to oral glucose tolerance test (OGTT) following a single oral administration of DSP-7238. To assess the chronic effects of DSP-7238 on glycaemic control and pancreatic beta-cell damage, DSP-7238 was administered for 11 weeks to mice made diabetic by a combination of high-fat diet (HFD) and a low-dose of streptozotocin (STZ). After the dosing period, HbA1c was measured and pancreatic damage was evaluated by biological and histological analyses. DSP-7238 and sitagliptin both competitively inhibited recombinant human DPP IV (rhDPP IV) with K(i) values of 0.60 and 2.1 nM respectively. Neither vildagliptin nor saxagliptin exhibited competitive inhibition of rhDPP IV. DSP-7238 did not inhibit DPP IV-related enzymes including DPP8, DPP9, DPP II and FAPalpha, whereas vildagliptin and saxagliptin showed inhibition of DPP8 and DPP9. Inhibition of glucagon-like peptide-1 (GLP-1) degradation by DSP-7238 was apparently more potent than its inhibition of chemokine (C-X-C motif) ligand 10 (IP-10) or chemokine (C-X-C motif) ligand 12 (SDF-1alpha) degradation. In contrast, vildagliptin and saxagliptin showed similar degree of inhibition of degradation for all the substrates tested. Compared to treatment with the vehicle, single oral administration of DSP-7238 dose-dependently decreased plasma DPP IV activity and improved glucose tolerance in DIO mice. In addition, DSP-7238 significantly decreased HbA1c and ameliorated pancreatic damage following 11 weeks of chronic treatment in HFD/STZ mice. We have shown in this study that DSP-7238 is a potent DPP IV inhibitor that has high specificity for DPP IV and substrate selectivity against GLP-1. We have also found that chronic treatment with DSP-7238 improves glycaemic control and ameliorates beta-cell damage in a mouse model with impaired insulin sensitivity and secretion. These findings indicate that DSP-7238 may be a new therapeutic agent for the treatment of type 2 diabetes.

Short-term modern life-like stress exacerbates Aβ-pathology and synapse loss in 3xTg-AD mice.

PubMed

Baglietto-Vargas, David; Chen, Yuncai; Suh, Dongjin; Ager, Rahasson R; Rodriguez-Ortiz, Carlos J; Medeiros, Rodrigo; Myczek, Kristoffer; Green, Kim N; Baram, Tallie Z; LaFerla, Frank M

2015-09-01

Alzheimer's disease (AD) is a progressive neurological disorder that impairs memory and other cognitive functions in the elderly. The social and financial impacts of AD are overwhelming and are escalating exponentially as a result of population aging. Therefore, identifying AD-related risk factors and the development of more efficacious therapeutic approaches are critical to cure this neurological disorder. Current epidemiological evidence indicates that life experiences, including chronic stress, are a risk for AD. However, it is unknown if short-term stress, lasting for hours, influences the onset or progression of AD. Here, we determined the effect of short-term, multi-modal 'modern life-like' stress on AD pathogenesis and synaptic plasticity in mice bearing three AD mutations (the 3xTg-AD mouse model). We found that combined emotional and physical stress lasting 5 h severely impaired memory in wild-type mice and tended to impact it in already low-performing 3xTg-AD mice. This stress reduced the number of synapse-bearing dendritic spines in 3xTg-AD mice and increased Aβ levels by augmenting AβPP processing. Thus, short-term stress simulating modern-life conditions may exacerbate cognitive deficits in preclinical AD by accelerating amyloid pathology and reducing synapse numbers. Epidemiological evidence indicates that life experiences, including chronic stress, are a risk for Alzheimer disease (AD). However, it is unknown if short stress in the range of hours influences the onset or progression of AD. Here, we determined the effect of short, multi-modal 'modern-lifelike'stress on AD pathogenesis and synaptic plasticity in mice bearing three AD mutations (the 3xTg-AD mouse model). We found that combined emotional and physical stress lasting 5 h severely impaired memory in wild-type mice and tended to impact it in already low-performing 3xTg-AD mice. This stress reduced the number of synapse-bearing dendritic spines in 3xTg-AD mice and increased Aβ levels by augmenting AβPP processing. Thus, short stress simulating modern-life conditions may exacerbate cognitive deficits in preclinical AD by accelerating amyloid pathology and reducing synapse numbers. © 2015 International Society for Neurochemistry.

Chronic potassium depletion increases adrenal progesterone production that is necessary for efficient renal retention of potassium.

PubMed

Elabida, Boutaïna; Edwards, Aurélie; Salhi, Amel; Azroyan, Anie; Fodstad, Heidi; Meneton, Pierre; Doucet, Alain; Bloch-Faure, May; Crambert, Gilles

2011-08-01

Modern dietary habits are characterized by high-sodium and low-potassium intakes, each of which was correlated with a higher risk for hypertension. In this study, we examined whether long-term variations in the intake of sodium and potassium induce lasting changes in the plasma concentration of circulating steroids by developing a mathematical model of steroidogenesis in mice. One finding of this model was that mice increase their plasma progesterone levels specifically in response to potassium depletion. This prediction was confirmed by measurements in both male mice and men. Further investigation showed that progesterone regulates renal potassium handling both in males and females under potassium restriction, independent of its role in reproduction. The increase in progesterone production by male mice was time dependent and correlated with decreased urinary potassium content. The progesterone-dependent ability to efficiently retain potassium was because of an RU486 (a progesterone receptor antagonist)-sensitive stimulation of the colonic hydrogen, potassium-ATPase (known as the non-gastric or hydrogen, potassium-ATPase type 2) in the kidney. Thus, in males, a specific progesterone concentration profile induced by chronic potassium restriction regulates potassium balance.

Cathepsin C Aggravates Neuroinflammation Involved in Disturbances of Behaviour and Neurochemistry in Acute and Chronic Stress-Induced Murine Model of Depression.

PubMed

Zhang, Yanli; Fan, Kai; Liu, Yanna; Liu, Gang; Yang, Xiaohan; Ma, Jianmei

2018-01-01

Major depression has been interpreted as an inflammatory disease characterized by cell-mediated immune activation, which is generally triggered by various stresses. Microglia has been thought to be the cellular link between inflammation and depression-like behavioural alterations. The expression of cathepsin C (Cat C), a lysosomal proteinase, is predominantly induced in microglia in neuroinflammation. However, little is known about the role of Cat C in pathophysiology of depression. In the present study, Cat C transgenic mice and wild type mice were subjected to an intraperitoneal injection of LPS (0.5 mg/kg) and 6-week unpredictable chronic mild stress (UCMS) exposure to establish acute and chronic stress-induced depression model. We examined and compared the behavioural and proinflammatory cytokine alterations in serum and depression-targeted brain areas of Cat C differentially expressed mice in stress, as well as indoleamine 2,3-dioxygenase (IDO) and 5-hydroxytryptamine (5HT) levels in brain. The results showed that Cat C overexpression (Cat C OE) promoted peripheral and central inflammatory response with significantly increased TNFα, IL-1β and IL-6 in serum, hippocampus and prefrontal cortex, and resultant upregulation of IDO and downregulation of 5HT expression in brain, and thereby aggravated depression-like behaviours accessed by open field test, forced swim test and tail suspension test. In contrast, Cat C knockdown (Cat C KD) partially prevented inflammation, which may help alleviate the symptoms of depression in mice. To the best of our knowledge, we are the first to demonstrate that Cat C aggravates neuroinflammation involved in disturbances of behaviour and neurochemistry in acute and chronic stress-induced murine model of depression.

Asthma progression to airway remodeling and bone marrow eosinophil responses in genetically distinct strains of mice.

PubMed

Hogan, Mary Beth; Piktel, Debra; Hubbs, Ann F; McPherson, Leslie E; Landreth, Kenneth S

2008-12-01

Patient factors that cause long-term airway remodeling are largely unidentified. This suggests that genetic differences may determine which asthmatic patients develop airway remodeling. A murine model with repeated allergen exposure leading to peribronchial fibrosis in complement factor 5 (C5)-deficient A/J mice has been used to study asthma progression. No studies have addressed the systemic effects of allergen sensitization or chronic allergen exposure on bone marrow eosinophilopoiesis in this mouse strain. To investigate bone marrow eosinophil responses during acute sensitization and chronic allergen exposure using genetically distinct mouse strains differing in persistent airway reactivity and remodeling. The C5-sufficient BALB/c and C5-deficient A/J mice were repetitively exposed to intranasal ovalbumin for 12 weeks. Subsequently, the mice were evaluated for airway eosinophilia, mucus-containing goblet cells, and peribronchial fibrosis. Both strains of mice were also acutely sensitized to ovalbumin. Bone marrow eosinophil progenitor cells and mature eosinophils were enumerated. BALB/c and A/J mice have similar bone marrow responses after acute allergen exposure, with elevations in bone marrow eosinophil progenitor cell and eosinophil numbers. After chronic allergen exposure, only C5-deficient A/J mice that developed peribronchial fibrosis exhibited bone marrow eosinophilia. BALB/c mice lacked peribronchial fibrosis and extinguished accelerated eosinophil production after long-term allergen challenge. Chronic airway remodeling after repeated allergen exposure in genetically different mice correlated with differences in long-term bone marrow eosinophilopoiesis. Preventing asthma from progressing to chronic airway remodeling with fibrosis may involve identifying genetically determined influences on bone marrow responses to chronic allergen exposure.

Evolution of the Immune Response to Chronic Airway Colonization with Aspergillus fumigatus Hyphae.

PubMed

Urb, Mirjam; Snarr, Brendan D; Wojewodka, Gabriella; Lehoux, Mélanie; Lee, Mark J; Ralph, Benjamin; Divangahi, Maziar; King, Irah L; McGovern, Toby K; Martin, James G; Fraser, Richard; Radzioch, Danuta; Sheppard, Donald C

2015-09-01

Airway colonization by the mold Aspergillus fumigatus is common in patients with underlying lung disease and is associated with chronic airway inflammation. Studies probing the inflammatory response to colonization with A. fumigatus hyphae have been hampered by the lack of a model of chronic colonization in immunocompetent mice. By infecting mice intratracheally with conidia embedded in agar beads (Af beads), we have established an in vivo model to study the natural history of airway colonization with live A. fumigatus hyphae. Histopathological examination and galactomannan assay of lung homogenates demonstrated that hyphae exited beads and persisted in the lungs of mice up to 28 days postinfection without invasive disease. Fungal lesions within the airways were surrounded by a robust neutrophilic inflammatory reaction and peribronchial infiltration of lymphocytes. Whole-lung cytokine analysis from Af bead-infected mice revealed an increase in proinflammatory cytokines and chemokines early in infection. Evidence of a Th2 type response was observed only early in the course of colonization, including increased levels of interleukin-4 (IL-4), elevated IgE levels in serum, and a mild increase in airway responsiveness. Pulmonary T cell subset analysis during infection mirrored these results with an initial transient increase in IL-4-producing CD4(+) T cells, followed by a rise in IL-17 and Foxp3(+) cells by day 14. These results provide the first report of the evolution of the immune response to A. fumigatus hyphal colonization. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Effect of combined treatment with diuretics and gabapentin on convulsive threshold in mice.

PubMed

Łukawski, Krzysztof; Swiderska, Grajyna; Czuczwar, Stanisław J

2013-01-01

Research data show that diuretics can have anticonvulsant properties. This study examined effects of ethacrynic acid, a loop diuretic, and hydrochlorothiazide, a thiazide-type diuretic, on the anticonvulsant activity of gabapentin, a newer antiepileptic drug, in the maximal electroshock seizure threshold test in mice. Diuretics were administered intraperitoneally (ip.) both acutely (single dose) and chronically (once daily for seven days). Electroconvulsions were produced by an alternating current (50 Hz, 500 V, 0.2 s stimulus duration) delivered via ear-clip electrodes by a generator. Additionally, the influence of combined treatment with the diuretics and gabapentin on motor performance in the chimney test has been assessed. In the current study, ethacrynic acid at the chronic dose of 12.5 mg/kg and the single dose of 100 mg/kg did not affect the anticonvulsant activity of gabapentin. Similarly, hydrochlorothiazide (100 mg/kg), both in acute and chronic experiments, had no effect on the gabapentin action. On the other hand, in the chimney test, the combined treatment with ethacrynic acid (100 mg/kg) and gabapentin (50 mg/kg) significantly impaired motor performance in mice. Based on the current preclinical findings, it can be suggested that the diuretics should not affect the anticonvulsant action of gabapentin in epileptic patients. However, the combination of ethacrynic acid with gabapentin may cause neurotoxicity.

Chronic effects of losartan on the muscles and the serologic profiles of mdx mice.

PubMed

Lee, Eun-Mi; Kim, Dae-Yong; Kim, Ah-Young; Lee, Eun-Joo; Kim, Sang-Hyeob; Lee, Myeong-Mi; Sung, Soo-Eun; Park, Jin-Kyu; Jeong, Kyu-Shik

2015-12-15

Losartan, an angiotensin II type 1 receptor blocker, attenuates transforming growth factor-β (TGF-β) signaling, which inhibits myogenic regeneration. Although many researchers have demonstrated that losartan has anti-fibrotic and protective effects on cardiac and skeletal muscles, for long-term administration to treat dystrophic disorders, it is essential to demonstrate not only the therapeutic effects of losartan on muscles but also its effects on other organs and on blood biochemistry. Mdx mice, an animal model of Duchenne muscular dystrophy (DMD), were fed losartan dissolved in tap water. After 44weeks, the skeletal (gastrocnemius), cardiac, and diaphragm muscles of mdx mice were removed. Tissue and blood samples were collected from all experimental animals. Effects of losartan on muscle regeneration, fibrosis, and blood enzymatic profiles were evaluated. In histopathological findings and serum biochemistry analyses, chronic losartan administration showed muscular protective effects and inhibited fibrosis in skeletal (gastrocnemius), cardiac, and diaphragmatic muscles. In addition, losartan had no effects on other solid organs. Interestingly, losartan had beneficial effects on serum HDL ratio. This study demonstrates the therapeutic effects of losartan on muscles and its effects on other organs and on blood biochemistry. In conclusion, our results provide useful information for consideration of chronic losartan administration be as a treatment of DMD. Copyright © 2015 Elsevier Inc. All rights reserved.

Immune response in the adipose tissue of lean mice infected with the protozoan parasite Neospora caninum

PubMed Central

Teixeira, Luzia; Moreira, João; Melo, Joana; Bezerra, Filipa; Marques, Raquel M; Ferreirinha, Pedro; Correia, Alexandra; Monteiro, Mariana P; Ferreira, Paula G; Vilanova, Manuel

2015-01-01

The adipose tissue can make important contributions to immune function. Nevertheless, only a limited number of reports have investigated in lean hosts the immune response elicited in this tissue upon infection. Previous studies suggested that the intracellular protozoan Neospora caninum might affect adipose tissue physiology. Therefore, we investigated in mice challenged with this protozoan if immune cell populations within adipose tissue of different anatomical locations could be differently affected. Early in infection, parasites were detected in the adipose tissue and by 7 days of infection increased numbers of macrophages, regulatory T (Treg) cells and T-bet+ cells were observed in gonadal, mesenteric, omental and subcutaneous adipose tissue. Increased expression of interferon-γ was also detected in gonadal adipose tissue of infected mice. Two months after infection, parasite DNA was no longer detected in these tissues, but T helper type 1 (Th1) cell numbers remained above control levels in the infected mice. Moreover, the Th1/Treg cell ratio was higher than that of controls in the mesenteric and subcutaneous adipose tissue. Interestingly, chronically infected mice presented a marked increase of serum leptin, a molecule that plays a role in energy balance regulation as well as in promoting Th1-type immune responses. Altogether, we show that an apicomplexa parasitic infection influences immune cellular composition of adipose tissue throughout the body as well as adipokine production, still noticed at a chronic phase of infection when parasites were already cleared from that particular tissue. This strengthens the emerging view that infections can have long-term consequences for the physiology of adipose tissue. PMID:25581844

Resveratrol (Trans-3,5,4′-trihydroxystilbene) Induces Silent Mating Type Information Regulation-1 and Down-Regulates Nuclear Transcription Factor-κB Activation to Abrogate Dextran Sulfate Sodium-Induced Colitis

PubMed Central

Singh, Udai P.; Singh, Narendra P.; Singh, Balwan; Hofseth, Lorne J.; Price, Robert L.; Nagarkatti, Mitzi

2010-01-01

Inflammatory bowel disease is a chronic, relapsing, and tissue-destructive disease. Resveratrol (3,4,5-trihydroxy-trans-stilbene), a naturally occurring polyphenol that exhibits beneficial pleiotropic health effects, is recognized as one of the most promising natural molecules in the prevention and treatment of chronic inflammatory disease and autoimmune disorders. In the present study, we investigated the effect of resveratrol on dextran sodium sulfate (DSS)-induced colitis in mice and found that it effectively attenuated overall clinical scores as well as various pathological markers of colitis. Resveratrol reversed the colitis-associated decrease in body weight and increased levels of serum amyloid A, tumor necrosis factor-α, interleukin (IL-6), and IL-1β. After resveratrol treatment, the percentage of CD4+ T cells in mesenteric lymph nodes (MLN) of colitis mice was restored to normal levels, and there was a decrease in these cells in the colon lamina propria (LP). Likewise, the percentages of macrophages in MLN and the LP of mice with colitis were decreased after resveratrol treatment. Resveratrol also suppressed cyclooxygenase-2 (COX-2) expression induced in DSS-exposed mice. Colitis was associated with a decrease in silent mating type information regulation-1 (SIRT1) gene expression and an increase in p-inhibitory κB expression and nuclear transcription factor-κB (NF-κB) activation. Resveratrol treatment of mice with colitis significantly reversed these changes. This study demonstrates for the first time that SIRT1 is involved in colitis, functioning as an inverse regulator of NF-κB activation and inflammation. Furthermore, our results indicate that resveratrol may protect against colitis through up-regulation of SIRT1 in immune cells in the colon. PMID:19940103

A Novel Bacterium Associated with Lymphadenitis in a Patient with Chronic Granulomatous Disease

PubMed Central

Greenberg, David E; Ding, Li; Zelazny, Adrian M; Stock, Frida; Wong, Alexandra; Anderson, Victoria L; Miller, Georgina; Kleiner, David E; Tenorio, Allan R; Brinster, Lauren; Dorward, David W; Murray, Patrick R; Holland, Steven M

2006-01-01

Chronic granulomatous disease (CGD) is a rare inherited disease of the phagocyte NADPH oxidase system causing defective production of toxic oxygen metabolites, impaired bacterial and fungal killing, and recurrent life-threatening infections. We identified a novel gram-negative rod in excised lymph nodes from a patient with CGD. Gram-negative rods grew on charcoal-yeast extract, but conventional tests could not identify it. The best 50 matches of the 16S rRNA (using BLAST) were all members of the family Acetobacteraceae, with the closest match being Gluconobacter sacchari. Patient serum showed specific band recognition in whole lysate immunoblot. We used mouse models of CGD to determine whether this organism was a genuine CGD pathogen. Intraperitoneal injection of gp91phox −/− (X-linked) and p47 phox −/− (autosomal recessive) mice with this bacterium led to larger burdens of organism recovered from knockout compared with wild-type mice. Knockout mouse lymph nodes had histopathology that was similar to that seen in our patient. We recovered organisms with 16S rRNA sequence identical to the patient's original isolate from the infected mice. We identified a novel gram-negative rod from a patient with CGD. To confirm its pathogenicity, we demonstrated specific immune reaction by high titer antibody, showed that it was able to cause similar disease when introduced into CGD, but not wild-type mice, and we recovered the same organism from pathologic lesions in these mice. Therefore, we have fulfilled Koch's postulates for a new pathogen. This is the first reported case of invasive human disease caused by any of the Acetobacteraceae. Polyphasic taxonomic analysis shows this organism to be a new genus and species for which we propose the name Granulobacter bethesdensis. PMID:16617373

Case Study: Polycystic Livers in a Transgenic Mouse Line

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lovaglio, Jamie A.; Artwohl, James E.; Ward, Christopher J.

Three mice (2 male, 1 female; age, 5 to 16 mo) from a mouse line transgenic for keratin 14 (K14)-driven LacZ expression and on an outbred Crl:CD1(ICR) background, were identified as having distended abdomens and livers that were diffusely enlarged by numerous cysts (diameter, 0.1 to 2.0 cm). Histopathology revealed hepatic cysts lined by biliary type epithelium and mild chronic inflammation, and confirmed the absence of parasites. Among 21 related mice, 5 additional affected mice were identified via laparotomy. Breeding of these 5 mice (after 5 mo of age) did not result in any offspring; the K14 mice with olycysticmore » livers failed to reproduce. Affected male mice had degenerative testicular lesions, and their sperm was immotile. Nonpolycystic K14 control male mice bred well, had no testicular lesions, and had appropriate sperm motility. Genetic analysis did not identify an association of this phenotype with the transgene or insertion site.« less

Chronic plus binge ethanol feeding induces myocardial oxidative stress, mitochondrial and cardiovascular dysfunction, and steatosis

PubMed Central

Matyas, Csaba; Varga, Zoltan V.; Mukhopadhyay, Partha; Paloczi, Janos; Lajtos, Tamas; Erdelyi, Katalin; Nemeth, Balazs T.; Nan, Mintong; Hasko, Gyorgy; Gao, Bin

2016-01-01

Alcoholic cardiomyopathy in humans develops in response to chronic excessive alcohol consumption; however, good models of alcohol-induced cardiomyopathy in mice are lacking. Herein we describe mouse models of alcoholic cardiomyopathies induced by chronic and binge ethanol (EtOH) feeding and characterize detailed hemodynamic alterations, mitochondrial function, and redox signaling in these models. Mice were fed a liquid diet containing 5% EtOH for 10, 20, and 40 days (d) combined with single or multiple EtOH binges (5 g/kg body wt). Isocalorically pair-fed mice served as controls. Left ventricular (LV) function and morphology were assessed by invasive pressure-volume conductance approach and by echocardiography. Mitochondrial complex (I, II, IV) activities, 3-nitrotyrosine (3-NT) levels, gene expression of markers of oxidative stress (gp91phox, p47phox), mitochondrial biogenesis (PGC1α, peroxisome proliferator-activated receptor α), and fibrosis were examined. Cardiac steatosis and fibrosis were investigated by histological/immunohistochemical methods. Chronic and binge EtOH feeding (already in 10 days EtOH plus single binge group) was characterized by contractile dysfunction (decreased slope of end-systolic pressure-volume relationship and preload recruitable stroke work), impaired relaxation (decreased time constant of LV pressure decay and maximal slope of systolic pressure decrement), and vascular dysfunction (impaired arterial elastance and lower total peripheral resistance). This was accompanied by enhanced myocardial oxidative/nitrative stress (3-NT; gp91phox; p47phox; angiotensin II receptor, type 1a) and deterioration of mitochondrial complex I, II, IV activities and mitochondrial biogenesis, excessive cardiac steatosis, and higher mortality. Collectively, chronic plus binge EtOH feeding in mice leads to alcohol-induced cardiomyopathies (National Institute on Alcohol Abuse and Alcoholism models) characterized by increased myocardial oxidative/nitrative stress, impaired mitochondrial function and biogenesis, and enhanced cardiac steatosis. PMID:27106042

Chronic plus binge ethanol feeding induces myocardial oxidative stress, mitochondrial and cardiovascular dysfunction, and steatosis.

PubMed

Matyas, Csaba; Varga, Zoltan V; Mukhopadhyay, Partha; Paloczi, Janos; Lajtos, Tamas; Erdelyi, Katalin; Nemeth, Balazs T; Nan, Mintong; Hasko, Gyorgy; Gao, Bin; Pacher, Pal

2016-06-01

Alcoholic cardiomyopathy in humans develops in response to chronic excessive alcohol consumption; however, good models of alcohol-induced cardiomyopathy in mice are lacking. Herein we describe mouse models of alcoholic cardiomyopathies induced by chronic and binge ethanol (EtOH) feeding and characterize detailed hemodynamic alterations, mitochondrial function, and redox signaling in these models. Mice were fed a liquid diet containing 5% EtOH for 10, 20, and 40 days (d) combined with single or multiple EtOH binges (5 g/kg body wt). Isocalorically pair-fed mice served as controls. Left ventricular (LV) function and morphology were assessed by invasive pressure-volume conductance approach and by echocardiography. Mitochondrial complex (I, II, IV) activities, 3-nitrotyrosine (3-NT) levels, gene expression of markers of oxidative stress (gp91phox, p47phox), mitochondrial biogenesis (PGC1α, peroxisome proliferator-activated receptor α), and fibrosis were examined. Cardiac steatosis and fibrosis were investigated by histological/immunohistochemical methods. Chronic and binge EtOH feeding (already in 10 days EtOH plus single binge group) was characterized by contractile dysfunction (decreased slope of end-systolic pressure-volume relationship and preload recruitable stroke work), impaired relaxation (decreased time constant of LV pressure decay and maximal slope of systolic pressure decrement), and vascular dysfunction (impaired arterial elastance and lower total peripheral resistance). This was accompanied by enhanced myocardial oxidative/nitrative stress (3-NT; gp91phox; p47phox; angiotensin II receptor, type 1a) and deterioration of mitochondrial complex I, II, IV activities and mitochondrial biogenesis, excessive cardiac steatosis, and higher mortality. Collectively, chronic plus binge EtOH feeding in mice leads to alcohol-induced cardiomyopathies (National Institute on Alcohol Abuse and Alcoholism models) characterized by increased myocardial oxidative/nitrative stress, impaired mitochondrial function and biogenesis, and enhanced cardiac steatosis. Copyright © 2016 the American Physiological Society.

Heterozygosity of mitogen-activated protein kinase organizer 1 ameliorates diabetic nephropathy and suppresses epithelial-to-mesenchymal transition-like changes in db/db mice.

PubMed

Loeffler, Ivonne; Liebisch, Marita; Daniel, Christoph; Amann, Kerstin; Wolf, Gunter

2017-12-01

Progressive diabetic nephropathy (DN) is characterized by tubulointerstitial fibrosis that is caused by accumulation of extracellular matrix. Induced by several factors, matrix-producing myofibroblasts may to some extent originate from tubular cells by epithelial-to-mesenchymal transition (EMT). Although previous data document that activation of hypoxia-inducible factor (HIF) signalling can be renoprotective in acute kidney disease, this issue remains controversial in chronic kidney injury. Here, we studied whether DN and EMT-like changes are ameliorated in a mouse model of type 2 diabetes mellitus with increased stability and activity of the HIF. We used db/db mice that were crossed with transgenic mice expressing reduced levels of mitogen-activated protein kinase organizer 1 (MORG1), a scaffold protein interacting with prolyl hydroxylase domain 3 (PHD3), because of deletion of one MORG1 allele. We found significantly reduced nephropathy in diabetic MORG1+/- heterozygous mice compared with the diabetic wild-types (db/dbXMORG1+/+). Furthermore, we demonstrated that EMT-like changes in the tubulointerstitium of diabetic wild-type MORG1+/+ mice are present, whereas diabetic mice with reduced expression of MORG1 showed significantly fewer EMT-like changes. These findings reveal that a deletion of one MORG1 allele inhibits the development of DN in db/db mice. The data suggest that the diminished interstitial fibrosis in these mice is a likely consequence of suppressed EMT-like changes. © The Author 2017. Published by Oxford University Press on behalf of ERA-EDTA. All rights reserved.

Activation of GPR30 attenuates chronic pain-related anxiety in ovariectomized mice.

PubMed

Liu, Shui-bing; Tian, Zhen; Guo, Yan-yan; Zhang, Nan; Feng, Bin; Zhao, Ming-gao

2015-03-01

Estrogen regulates neuroendocrine and inflammatory processes that play critical roles in neuroinflammation, anxiety, and chronic pain. Patients suffering from chronic pain often complain of anxiety. However, limited information is available regarding the neural circuitry of chronic pain-related anxiety and the related function of estrogen. Hindpaw injection of complete Freund's adjuvant (CFA) and chronic constriction injury (CCI) of the sciatic nerve induced notable pain sensitization and anxiety-like behavior in ovariectomized (OVX) mice. We found that the level of G-protein-coupled receptor 30 (GPR30), a membrane estrogen receptor, was significantly increased in the basolateral amygdala (BLA) of ovariectomized (OVX) mice suffering from chronic inflammatory and neuropathic pain. Subcutaneous injection or BLA local infusion of the GPR30 agonist G1 significantly reduced anxiety-like behavior in CFA-injected and CCI-OVX mice; however, this treatment did not alter the nociceptive threshold. GPR30 knock down by shRNA in the BLA of OVX mice inhibited the anxiolytic effects of GPR30 activation. G1 administration reversed the upregulation of GluR1 subunit in AMPA and NR2A-containing NMDA receptors and the downregulation of GABAA receptors in the BLA of CFA-injected and CCI-OVX mice. Electrophysiological recording revealed that GPR30 activation could prevent imbalance between excitatory and inhibitory transmissions in the BLA synapses of CFA-injected OVX mice. In conclusion, GPR30 activation induced anxiolytic effects but did not affect the nociceptive threshold of mice under chronic pain. The anxiolytic effects of GPR30 were partially due to maintaining the balance between excitatory and inhibitory transmissions in the BLA. Copyright © 2015 Elsevier Ltd. All rights reserved.

Effect of baclofen on morphine-induced conditioned place preference, extinction, and stress-induced reinstatement in chronically stressed mice.

PubMed

Meng, Shanshan; Quan, Wuxing; Qi, Xu; Su, Zhiqiang; Yang, Shanshan

2014-01-01

A stress-induced increase in excitability can result from a reduction in inhibitory neurotransmission. Modulation of gamma-aminobutyric acid (GABA)ergic transmission is an effective treatment for drug seeking and relapse. This study investigated whether baclofen, a GABA(B) receptor agonist, had an impact on morphine-induced conditioned place preference (CPP), extinction, and stress-induced relapse in chronically stressed mice. Chronic stress was induced by restraining mice for 2 h for seven consecutive days. We first investigated whether chronic stress influenced morphine-induced CPP, extinction, and stress-induced relapse in the stressed mice. Next, we investigated whether three different doses of baclofen influenced chronic stress as measured by the expression of morphine-induced CPP. We chose the most effective dose for subsequent extinction and reinstatement experiments. Reinstatement of morphine-induced CPP was induced by a 6-min forced swim stress. Locomotor activity was also measured for each test. Chronic stress facilitated the expression of morphine-induced CPP and prolonged extinction time. Forced swim stress primed the reinstatement of morphine-induced CPP in mice. Baclofen treatment affected the impact of chronic stress on different phases of morphine-induced CPP. Our results showed that baclofen antagonized the effects of chronic stress on morphine-induced CPP. These findings suggest the potential clinical utility of GABA(B) receptor-positive modulators as an anti-addiction agent in people suffering from chronic stress.

Epidermolysis Bullosa Acquitsita

PubMed Central

Gupta, Rishu; Woodley, David T.; Chen, Mei

2011-01-01

EBA is a rare, acquired, chronic subepidermal bullous disease of the skin and mucosa characterized by autoantibodies to type VII collagen structures, a major component of anchoring fibrils, that attach the epidermis onto the dermis. EBA patients have tissue-bound as well as circulating anti-type VII collagen autoantibodies that attack type VII collagen and result in a reduction or perturbation of normally functioning anchoring fibrils. Patients with EBA have skin fragility, blisters, erosions, scars, milia, and nail loss: all features reminiscent of genetic dystrophic epidermolysis bullosa. These anti-type VII collagen antibodies are “pathogenic” because when injected into mice, the mice develop an EBA-like blistering disease. In addition to the classical mechanobullous presentation, EBA also has several other distinct clinical syndromes similar to bullous pemphigoid, Brunsting-Perry pemphigoid, or cicatricial pemphigoid. Although treatment for EBA is often unsatisfactory, some therapeutic success has been achieved with colchicine, dapsone, plasmaphoresis, photopheresis, infliximab, and intravenous immunoglobulin. PMID:22137228

Sensitivity and dose dependency of radiation-induced injury in hematopoietic stem/progenitor cells in mice

PubMed Central

Guo, Chang-Ying; Luo, Lan; Urata, Yoshishige; Goto, Shinji; Huang, Wen-Jing; Takamura, Syu; Hayashi, Fumiko; Doi, Hanako; Kitajima, Yuriko; Ono, Yusuke; Ogi, Tomoo; Li, Tao-Sheng

2015-01-01

We evaluated the sensitivity and dose dependency of radiation-induced injury in hematopoietic stem/progenitor cells. Adult C57BL/6 mice were daily exposed to 0, 2, 10, 50, and 250 mGy γ-ray for 1 month in succession, respectively. The damage of hematopoietic stem/progenitor cells in bone marrow were investigated within 2 hours (acute phase) or at 3 months (chronic phase) after the last exposure. Daily exposure to over 10 mGy γ-ray significantly decreased the number and colony-forming capacity of hematopoietic stem/progenitor cells at acute phase, and did not completely recover at chronic phase with 250 mGy exposure. Interestingly, the daily exposure to 10 or 50 mGy γ-ray decreased the formation of mixed types of colonies at chronic phase, but the total number of colonies was comparable to control. Immunostaining analysis showed that the formation of 53BP1 foci in c-kit+ stem/progenitor cells was significantly increased with daily exposure to 50 and 250 mGy at acute phase, and 250 mGy at chronic phase. Many genes involved in toxicity responses were up- or down-regulated with the exposures to all doses. Our data have clearly shown the sensitivity and dose dependency of radiation-induced injury in hematopoietic stem/progenitor cells of mice with daily exposures to 2 ~ 250 mGy γ-ray. PMID:25623887

Miso (Japanese soybean paste) soup attenuates salt-induced sympathoexcitation and left ventricular dysfunction in mice with chronic pressure overload.

PubMed

Ito, Koji; Hirooka, Yoshitaka; Sunagawa, Kenji

2014-02-01

The hypothalamic mineralocorticoid receptor (MR)-angiotensin II type 1 receptor (AT1R) pathway is activated in mice with chronic pressure overload (CPO). When this activation is combined with high salt intake, it leads to sympathoexcitation, hypertension, and left ventricular (LV) dysfunction. Salt intake is thus an important factor that contributes to heart failure. Miso, a traditional Japanese food made from fermented soybeans, rice, wheat, or oats, can attenuate salt-induced hypertension in rats. However, its effects on CPO mice with salt-induced sympathoexcitation and LV dysfunction are unclear. Here, we investigated whether miso has protective effects in these mice. We also evaluated mechanisms associated with the hypothalamic MR-AT1R pathway. Aortic banding was used to produce CPO, and a sham operation was performed for controls. At 2 weeks after surgery, the mice were given water containing high NaCl levels (0.5%, 1.0%, and 1.5%) for 4 weeks. The high salt loading in CPO mice increased excretion of urinary norepinephrine (uNE), a marker of sympathetic activity, in an NaCl concentration-dependent manner; however, this was not observed in Sham mice. Subsequently, CPO mice were administered 1.0% NaCl water (CPO-H) or miso soup (1.0% NaCl equivalent, CPO-miso). The expression of hypothalamic MR, serum glucocorticoid-induced kinase-1 (SGK-1), and AT1R was higher in the CPO-H mice than in the Sham mice; however, the expression of these proteins was attenuated in the CPO-miso group. Although the CPO-miso mice had higher sodium intake, salt-induced sympathoexcitation was lower in these mice than in the CPO-H group. Our findings indicate that regular intake of miso soup attenuates salt-induced sympathoexcitation in CPO mice via inhibition of the hypothalamic MR-AT1R pathway.

Improvement of spatial memory function in APPswe/PS1dE9 mice after chronic inhibition of phosphodiesterase type 4D.

PubMed

Sierksma, A S R; van den Hove, D L A; Pfau, F; Philippens, M; Bruno, O; Fedele, E; Ricciarelli, R; Steinbusch, H W M; Vanmierlo, T; Prickaerts, J

2014-02-01

Phosphodiesterase type 4 inhibitors (PDE4-Is) have received increasing attention as cognition-enhancers and putative treatment strategies for Alzheimer's disease (AD). By preventing cAMP breakdown, PDE4-Is can enhance intracellular signal transduction and increase the phosphorylation of cAMP response element-binding protein (CREB) and transcription of proteins related to synaptic plasticity and associated memory formation. Unfortunately, clinical development of PDE4-Is has been seriously hampered by emetic side effects. The new isoform-specific PDE4D-I, GEBR-7b, has shown to have beneficial effects on memory at non-emetic doses. The aim of the current study was to investigate chronic cognition-enhancing effects of GEBR-7b in a mouse model of AD. To this extent, 5-month-old (5M) APPswe/PS1dE9 mice received daily subcutaneous injections with GEBR-7b (0.001 mg/kg) or vehicle for a period of 3 weeks, and were tested on affective and cognitive behavior at 7M. We demonstrated a cognition-enhancing potential in APPswe/PS1dE9 mice as their spatial memory function at 7M in the object location test was improved by prior GEBR-7b treatment. APPswe/PS1dE9 mice displayed lower levels of CREB phosphorylation, which remained unaltered after chronic GEBR-7b treatment, and higher levels of tau in the hippocampus. Hippocampal brain-derived neurotrophic factor levels and synaptic densities were not different between experimental groups and no effects were observed on hippocampal GSK3β and tau phosphorylation or Aβ levels. In conclusion, GEBR-7b can enhance spatial memory function in the APPswe/PS1dE9 mouse model of AD. Although the underlying mechanisms of its cognition-enhancing potential remain to be elucidated, PDE4D inhibition appears an interesting novel therapeutic option for cognitive deficits in AD. Copyright © 2013 Elsevier Ltd. All rights reserved.

Chronic alcohol consumption from adolescence-to-adulthood in mice--effect on growth and social behavior.

PubMed

Zou, Hong; Xie, Qinglian; Zhang, Manfang; Zhang, Chenghao; Zhao, Guoping; Jin, Meilei; Yu, Lei

2009-09-01

Experimentation with alcohol is common during adolescence. However the long-term consequences from moderate alcohol use during adolescence development are not clear. Using a two-bottle free-choice paradigm in the home-cage setting, we studied adolescent mice (4 weeks old) across a 6-week time span of the adolescence-to-adulthood development period. Adolescent mice readily reached a steady level of alcohol consumption and maintained this level throughout the 6-week period. Chronic alcohol consumption resulted in reduced growth in adolescent mice, as well as accelerated acclimation to a novel environment. During a social interaction test, similar levels of initial social investigation and subsequent habituation were observed in both the chronic alcohol and the water-only control groups. However, chronic alcohol self-administration resulted in impaired social recognition and decreased social play/fight behavior. Taken together, these results indicated that chronic alcohol consumption across adolescence development negatively impacted both physical growth and social behavior in mice, highlighting the detrimental consequences from prolonged alcohol drinking in adolescence.

Mice overexpressing corticotropin-releasing factor show brain atrophy and motor dysfunctions.

PubMed

Goebel, Miriam; Fleming, Sheila M; Million, Mulugeta; Stengel, Andreas; Taché, Yvette; Wang, Lixin

2010-03-31

Chronic stress and persistently high glucocorticoid levels can induce brain atrophy. Corticotropin-releasing factor (CRF)-overexpressing (OE) mice are a genetic model of chronic stress with elevated brain CRF and plasma corticosterone levels and Cushing's syndrome. The brain structural alterations in the CRF-OE mice, however, are not well known. We found that adult male and female CRF-OE mice had significantly lower whole brain and cerebellum weights than their wild type (WT) littermates (347.7+/-3.6mg vs. 460.1+/-4.3mg and 36.3+/-0.8mg vs. 50.0+/-1.3mg, respectively) without sex-related difference. The epididymal/parametrial fat mass was significantly higher in CRF-OE mice. The brain weight was inversely correlated to epididymal/parametrial fat weight, but not to body weight. Computerized image analysis system in Nissl-stained brain sections of female mice showed that the anterior cingulate and sensorimotor cortexes of CRF-OE mice were significantly thinner, and the volumes of the hippocampus, hypothalamic paraventricular nucleus and amygdala were significantly reduced compared to WT, while the locus coeruleus showed a non-significant increase. Motor functions determined by beam crossing and gait analysis showed that CRF-OE mice took longer time and more steps to traverse a beam with more errors, and displayed reduced stride length compared to their WT littermates. These data show that CRF-OE mice display brain size reduction associated with alterations of motor coordination and an increase in visceral fat mass providing a novel animal model to study mechanisms involved in brain atrophy under conditions of sustained elevation of brain CRF and circulating glucocorticoid levels. Copyright 2010 Elsevier Ireland Ltd. All rights reserved.

Dependence-induced ethanol drinking and GABA neurotransmission are altered in Alk deficient mice

PubMed Central

Schweitzer, Paul; Cates-Gatto, Chelsea; Varodayan, Florence P.; Nadav, Tali; Roberto, Marisa; Lasek, Amy W.; Roberts, Amanda J.

2016-01-01

Anaplastic lymphoma kinase (ALK) is a receptor tyrosine kinase that is expressed in the brain and implicated in alcohol abuse in humans and behavioral responses to ethanol in mice. Previous studies have shown an association of human ALK with acute responses to alcohol and alcohol dependence. In addition, Alk knockout (Alk −/−) mice consume more ethanol in a binge-drinking test and show increased sensitivity to ethanol sedation. However, the function of ALK in excessive drinking following the establishment of ethanol dependence has not been examined. In this study, we tested Alk −/− mice for dependence-induced drinking using the chronic intermittent ethanol-two bottle choice drinking (CIE-2BC) protocol. We found that Alk −/− mice initially consume more ethanol prior to CIE exposure, but do not escalate ethanol consumption after exposure, suggesting that ALK may promote the escalation of drinking after ethanol dependence. To determine the mechanism(s) responsible for this behavioral phenotype we used an electrophysiological approach to examine GABA neurotransmission in the central nucleus of the amygdala (CeA), a brain region that regulates alcohol consumption and shows increased GABA signaling after chronic ethanol exposure. GABA transmission in ethanol-naïve Alk −/− mice was enhanced at baseline and potentiated in response to acute ethanol application when compared to wild-type (Alk +/+) mice. Moreover, basal GABA transmission was not elevated by CIE exposure in Alk −/− mice as it was in Alk +/+ mice. These data suggest that ALK plays a role in dependence-induced drinking and the regulation of presynaptic GABA release in the CeA. PMID:26946429

Helminth infections predispose mice to pneumococcal pneumonia but not to other pneumonic pathogens.

PubMed

Apiwattanakul, Nopporn; Thomas, Paul G; Kuhn, Raymond E; Herbert, De'Broski R; McCullers, Jonathan A

2014-10-01

Pneumonia is the leading killer of children worldwide. Here, we report that helminth-infected mice develop fatal pneumonia when challenged with Streptococcus pneumoniae. Mice were chronically infected with either the flatworm Taenia crassiceps or the roundworm Heligmosomoides polygyrus. Upon challenge with a pneumonic type 3 strain of S. pneumoniae (A66.1), the worm-infected mice developed pneumonia at a rate and to a degree higher than age-matched control mice as measured by bioluminescent imaging and lung titers. This predisposition to pneumonia appears to be specific to S. pneumoniae, as worm-infected mice did not show evidence of increased morbidity when challenged with a lethal dose of influenza virus or sublethal doses of Staphylococcus aureus or Listeria monocytogenes. The defect was also present when worm-infected mice were challenged with a type 2 sepsis-causing strain (D39); an increased rate of pneumonia, decreased survival, and increased lung and blood titers were found. Pneumococcal colonization and immunity against acute otitis media were unaffected. Anti-helminthic treatment in the H. polygyrus model reversed this susceptibility. We conclude that helminth coinfection predisposes mice to fatal pneumococcal pneumonia by promoting increased outgrowth of bacteria in the lungs and blood. These data have broad implications for the prevention and treatment for pneumonia in the developing world, where helminth infections are endemic and pneumococcal pneumonia is common.

Chronic plus binge ethanol exposure causes more severe pancreatic injury and inflammation.

PubMed

Ren, Zhenhua; Yang, Fanmuyi; Wang, Xin; Wang, Yongchao; Xu, Mei; Frank, Jacqueline A; Ke, Zun-Ji; Zhang, Zhuo; Shi, Xianglin; Luo, Jia

2016-10-01

Alcohol abuse increases the risk for pancreatitis. The pattern of alcohol drinking may impact its effect. We tested a hypothesis that chronic ethanol consumption in combination with binge exposure imposes more severe damage to the pancreas. C57BL/6 mice were divided into four groups: control, chronic ethanol exposure, binge ethanol exposure and chronic plus binge ethanol exposure. For the control group, mice were fed with a liquid diet for two weeks. For the chronic ethanol exposure group, mice were fed with a liquid diet containing 5% ethanol for two weeks. In the binge ethanol exposure group, mice were treated with ethanol by gavage (5g/kg, 25% ethanol w/v) daily for 3days. For the chronic plus binge exposure group, mice were fed with a liquid diet containing 5% ethanol for two weeks and exposed to ethanol by gavage during the last 3days. Chronic and binge exposure alone caused minimal pancreatic injury. However, chronic plus binge ethanol exposure induced significant apoptotic cell death. Chronic plus binge ethanol exposure altered the levels of alpha-amylase, glucose and insulin. Chronic plus binge ethanol exposure caused pancreatic inflammation which was shown by the macrophages infiltration and the increase of cytokines and chemokines. Chronic plus binge ethanol exposure increased the expression of ADH1 and CYP2E1. It also induced endoplasmic reticulum stress which was demonstrated by the unfolded protein response. In addition, chronic plus binge ethanol exposure increased protein oxidation and lipid peroxidation, indicating oxidative stress. Therefore, chronic plus binge ethanol exposure is more detrimental to the pancreas. Copyright © 2016 Elsevier Inc. All rights reserved.

Agmatine reduces only peripheral-related behavioral signs, not the central signs, of morphine withdrawal in nNOS deficient transgenic mice.

PubMed

Aricioglu, Feyza; Paul, Ian A; Regunathan, Soundar

2004-01-09

Agmatine inhibits morphine tolerance/dependence and potentiates morphine analgesia. This study was designed to investigate whether neuronal nitric oxide mediates the actions of agmatine in morphine dependence by using mice lacking a functional form of this enzyme. Mice received agmatine just after the morphine pellet implantation for 3 days twice daily or single injection 30 min before naloxone. In both genotypes treated for 3 days with morphine pellets, naloxone administration precipitated clear signs of withdrawal. Both acute and chronic administration of agmatine reduced withdrawal signs in wild type mice and reduced only peripheral signs of morphine dependence in neuronal nitric oxide synthase knockout mice. Withdrawal signs, that are related to central nervous system activity were not affected. These findings indicate that neuronal nitric oxide synthase partly mediates the effects of agmatine in morphine physical dependence.

Gonadectomy prevents the increase in blood pressure and glomerular injury in angiotensin-converting enzyme 2 knockout diabetic male mice. Effects on renin-angiotensin system.

PubMed

Clotet, Sergi; Soler, María José; Rebull, Marta; Gimeno, Javier; Gurley, Susan B; Pascual, Julio; Riera, Marta

2016-09-01

Angiotensin-converting enzyme 2 (ACE2) deletion worsens kidney injury, and its amplification ameliorates diabetic nephropathy. Male sex increases the incidence, prevalence, and progression of chronic kidney disease in our environment. Here, we studied the effect of ACE2 deficiency and gonadectomy (GDX) on diabetic nephropathy and its relationship with fibrosis, protein kinase B (Akt) activation, and the expression of several components of the renin-angiotensin system (RAS).Mice were injected with streptozotocin to induce diabetes and followed for 19 weeks. Physiological and renal parameters were studied in wild-type and ACE2 knockout (ACE2KO) male mice with and without GDX. Diabetic ACE2KO showed increased blood pressure (BP), glomerular injury, and renal fibrosis compared with diabetic wild-type. Gonadectomized diabetic ACE2KO presented a decrease in BP. In the absence of ACE2, GDX attenuated albuminuria and renal lesions, such as mesangial matrix expansion and podocyte loss. Both, α-smooth muscle actin accumulation and collagen deposition were significantly decreased in renal cortex of gonadectomized diabetic ACE2KO but not diabetic wild-type mice. GDX also reduced circulating ACE activity in ACE2KO mice. Loss of ACE2 modified the effect of GDX on cortical gene expression of RAS in diabetic mice. Akt phosphorylation in renal cortex was increased by diabetes and loss of ACE2 and decreased by GDX in control and diabetic ACE2KO but not in wild-type mice. Our results suggest that GDX may exert a protective effect within the kidney under pathological conditions of diabetes and ACE2 deficiency. This renoprotection may be ascribed to different mechanisms such as decrease in BP, modulation of RAS, and downregulation of Akt-related pathways.

Both chronic treatments by epothilone D and fluoxetine increase the short-term memory and differentially alter the mood status of STOP/MAP6 KO mice.

PubMed

Fournet, Vincent; de Lavilléon, Gaetan; Schweitzer, Annie; Giros, Bruno; Andrieux, Annie; Martres, Marie-Pascale

2012-12-01

Recent evidence underlines the crucial role of neuronal cytoskeleton in the pathophysiology of psychiatric diseases. In this line, the deletion of STOP/MAP6 (Stable Tubule Only Polypeptide), a microtubule-stabilizing protein, triggers various neurotransmission and behavioral defects, suggesting that STOP knockout (KO) mice could be a relevant experimental model for schizoaffective symptoms. To establish the predictive validity of such a mouse line, in which the brain serotonergic tone is dramatically imbalanced, the effects of a chronic fluoxetine treatment on the mood status of STOP KO mice were characterized. Moreover, we determined the impact, on mood, of a chronic treatment by epothilone D, a taxol-like microtubule-stabilizing compound that has previously been shown to improve the synaptic plasticity deficits of STOP KO mice. We demonstrated that chronic fluoxetine was either antidepressive and anxiolytic, or pro-depressive and anxiogenic, depending on the paradigm used to test treated mutant mice. Furthermore, control-treated STOP KO mice exhibited paradoxical behaviors, compared with their clear-cut basal mood status. Paradoxical fluoxetine effects and control-treated STOP KO behaviors could be because of their hyper-reactivity to acute and chronic stress. Interestingly, both epothilone D and fluoxetine chronic treatments improved the short-term memory of STOP KO mice. Such treatments did not affect the serotonin and norepinephrine transporter densities in cerebral areas of mice. Altogether, these data demonstrated that STOP KO mice could represent a useful model to study the relationship between cytoskeleton, mood, and stress, and to test innovative mood treatments, such as microtubule-stabilizing compounds. © 2012 The Authors Journal of Neurochemistry © 2012 International Society for Neurochemistry.

Complement Component 5 Mediates Development of Fibrosis, via Activation of Stellate Cells, in 2 Mouse Models of Chronic Pancreatitis

PubMed Central

Sendler, Matthias; Beyer, Georg; Mahajan, Ujjwal M.; Kauschke, Vivien; Maertin, Sandrina; Schurmann, Claudia; Homuth, Georg; Völker, Uwe; Völzke, Henry; Halangk, Walter; Wartmann, Thomas; Weiss, Frank-Ulrich; Hegyi, Peter; Lerch, Markus M.; Mayerle, Julia

2015-01-01

Background & Aims Little is known about the pathogenic mechanisms of chronic pancreatitis. We investigated the roles of complement component 5 (C5) in pancreatic fibrogenesis in mice and patients. Methods Chronic pancreatitis was induced by ligation of the midpancreatic duct, followed by a single supramaximal intraperitoneal injection of cerulein, in C57Bl6 (control) and C5-deficient mice. Some mice were given injections of 2 different antagonists of the receptor for C5a over 21 days. In a separate model, mice were given injections of cerulein for 10 weeks to induce chronic pancreatitis. Direct effects of C5 were studied in cultured primary cells. We performed genotype analysis for the single-nucleotide polymorphisms rs 17611 and rs 2300929 in C5 in patients with pancreatitis and healthy individuals (controls). Blood cells from 976 subjects were analyzed by transcriptional profiling. Results During the initial phase of pancreatitis, levels of pancreatic damage were similar between C5-deficient and control mice. During later stages of pancreatitis, C5-deficient mice and mice given injections of C5a-receptor antagonists developed significantly less pancreatic fibrosis than control mice. Primary pancreatic stellate cells were activated in vitro by C5a. There were no differences in the rs 2300929 SNP between subjects with or without pancreatitis, but the minor allele rs17611 was associated with a significant increase in levels of C5 in whole blood. Conclusions In mice, loss of C5 or injection of a C5a-receptor antagonist significantly reduced the level of fibrosis of chronic pancreatitis, but this was not a consequence of milder disease in early stages of pancreatitis. C5 might be a therapeutic target for chronic pancreatitis. PMID:26001927

BTB and CNC homolog 1 (Bach1) deficiency ameliorates TNBS colitis in mice: role of M2 macrophages and heme oxygenase-1.

PubMed

Harusato, Akihito; Naito, Yuji; Takagi, Tomohisa; Uchiyama, Kazuhiko; Mizushima, Katsura; Hirai, Yasuko; Higashimura, Yasuki; Katada, Kazuhiro; Handa, Osamu; Ishikawa, Takeshi; Yagi, Nobuaki; Kokura, Satoshi; Ichikawa, Hiroshi; Muto, Akihiko; Igarashi, Kazuhiko; Yoshikawa, Toshikazu

2013-01-01

BTB and CNC homolog 1 (Bach1) is a transcriptional repressor of heme oxygenase-1 (HO-1), which plays an important role in the protection of cells and tissues against acute and chronic inflammation. However, the role of Bach1 in the gastrointestinal mucosal defense system remains little understood. HO-1 supports the suppression of experimental colitis and localizes mainly in macrophages in colonic mucosa. This study was undertaken to elucidate the Bach1/HO-1 system's effects on the pathogenesis of experimental colitis. This study used C57BL/6 (wild-type) and homozygous Bach1-deficient C57BL/6 mice in which colonic damage was induced by the administration of an enema of 2,4,6-trinitrobenzene sulfonic acid (TNBS). Subsequently, they were evaluated macroscopically, histologically, and biochemically. Peritoneal macrophages from the respective mice were isolated and analyzed. Then, wild-type mice were injected with peritoneal macrophages from the respective mice. Acute colitis was induced similarly. TNBS-induced colitis was inhibited in Bach1-deficient mice. TNBS administration increased the expression of HO-1 messenger RNA and protein in colonic mucosa in Bach1-deficient mice. The expression of HO-1 mainly localized in F4/80-immunopositive and CD11b-immunopositive macrophages. Isolated peritoneal macrophages from Bach1-deficient mice highly expressed HO-1 and also manifested M2 macrophage markers, such as Arginase-1, Fizz-1, Ym1, and MRC1. Furthermore, TNBS-induced colitis was inhibited by the transfer of Bach1-deficient macrophages into wild-type mice. Deficiency of Bach1 ameliorated TNBS-induced colitis. Bach1-deficient macrophages played a key role in protection against colitis. Targeting of this mechanism is applicable to cell therapy for human inflammatory bowel disease.

Acetaminophen hepatotoxicity in mice: Effect of age, frailty and exposure type

PubMed Central

Kane, Alice E.; Mitchell, Sarah J.; Mach, John; Huizer-Pajkos, Aniko; McKenzie, Catriona; Jones, Brett; Cogger, Victoria; Le Couteur, David G.; de Cabo, Rafael; Hilmer, Sarah N.

2018-01-01

Acetaminophen is a commonly used analgesic that can cause severe hepatotoxicity in overdose. Despite old age and frailty being associated with extensive and long-term utilization of acetaminophen and a high prevalence of adverse drug reactions, there is limited information on the risks of toxicity from acetaminophen in old age and frailty. This study aimed to assess changes in the risk and mechanisms of hepatotoxicity from acute, chronic and sub-acute acetaminophen exposure with old age and frailty in mice. Young and old male C57BL/6 mice were exposed to either acute (300 mg/kg via oral gavage), chronic (100 mg/kg/day in diet for six weeks) or sub-acute (250 mg/kg, t.i.d., for three days) acetaminophen, or saline control. Pre-dosing mice were scored for the mouse clinical frailty index, and after dosing serum and liver tissue were collected for assessment of toxicity and mechanisms. There were no differences with old age or frailty in the degree of hepatotoxicity induced by acute, chronic or subacute acetaminophen exposure as assessed by serum liver enzymes and histology. Age-related changes in the acetaminophen toxicity pathways included increased liver GSH concentrations, increased NQO1 activity and an increased pro- and anti-inflammatory response to acetaminophen in old age. Frailty-related changes included a negative correlation between frailty index and serum protein, albumin and ALP concentrations for some mouse groups. In conclusion, although there were changes in some pathways that would be expected to influence susceptibility to acetaminophen toxicity, there was no overall increase in acetaminophen hepatotoxicity with old age or frailty in mice. PMID:26615879

Metabolic Benefit of Chronic Caloric Restriction and Activation of Hypothalamic AGRP/NPY Neurons in Male Mice Is Independent of Ghrelin

PubMed Central

Rogers, Nicole H.; Walsh, Heidi; Alvarez-Garcia, Oscar; Park, Seongjoon; Gaylinn, Bruce; Thorner, Michael O.

2016-01-01

Aging is associated with attenuated ghrelin signaling. During aging, chronic caloric restriction (CR) produces health benefits accompanied by enhanced ghrelin production. Ghrelin receptor (GH secretagogue receptor 1a) agonists administered to aging rodents and humans restore the young adult phenotype; therefore, we tested the hypothesis that the metabolic benefits of CR are mediated by endogenous ghrelin. Three month-old male mice lacking ghrelin (Ghrelin−/−) or ghrelin receptor (Ghsr−/−), and their wild-type (WT) littermates were randomly assigned to 2 groups: ad libitum (AL) fed and CR, where 40% food restriction was introduced gradually to allow Ghrelin−/− and Ghsr−/− mice to metabolically adapt and avoid severe hypoglycemia. Twelve months later, plasma ghrelin, metabolic parameters, ambulatory activity, hypothalamic and liver gene expression, as well as body composition were measured. CR increased plasma ghrelin and des-acyl ghrelin concentrations in WT and Ghsr−/− mice. CR of WT, Ghsr−/−, and Ghrelin−/− mice markedly improved metabolic flexibility, enhanced ambulatory activity, and reduced adiposity. Inactivation of Ghrelin or Ghsr had no effect on AL food intake or food anticipatory behavior. In contrast to the widely held belief that endogenous ghrelin regulates food intake, CR increased expression of hypothalamic Agrp and Npy, with reduced expression of Pomc across genotypes. In the AL context, ablation of ghrelin signaling markedly inhibited liver steatosis, which correlated with reduced Pparγ expression and enhanced Irs2 expression. Although CR and administration of GH secretagogue receptor 1a agonists both benefit the aging phenotype, we conclude the benefits of chronic CR are a consequence of enhanced metabolic flexibility independent of endogenous ghrelin or des-acyl ghrelin signaling. PMID:26812158

Alcohol-induced tolerance and physical dependence in mice with ethanol insensitive α1 GABAA receptors

PubMed Central

Werner, David F.; Swihart, Andrew R.; Ferguson, Carolyn; Lariviere, William R.; Harrison, Neil L.; Homanics, Gregg E.

2009-01-01

Background Although many people consume alcohol (ethanol), it remains unknown why some become addicted. Elucidating the molecular mechanisms of tolerance and physical dependence (withdrawal) may provide insight into alcohol addiction. While the exact molecular mechanisms of ethanol action are unclear, γ-aminobutyric acid type A receptors (GABAA-Rs) have been extensively implicated in ethanol action. The α1 GABAA-R subunit is associated with tolerance and physical dependence, but its exact role remains unknown. In this report, we tested the hypothesis that α1-GABAA-Rs mediate in part these effects of ethanol. Methods Ethanol-induced behavioral responses related to tolerance and physical dependence were investigated in knockin mice that have ethanol-insensitive α1 GABAA-Rs and wildtype controls. Acute functional tolerance (AFT) was assessed using the stationary dowel and loss of righting reflex assays. Chronic tolerance was assessed on the loss of righting reflex, fixed speed rotarod, hypothermia, and radiant tail flick assays following ten consecutive days of ethanol exposure. Withdrawal-related hyperexcitability was assessed by handling-induced convulsions following 3 cycles of ethanol vapor exposure/withdrawal. Immunoblots were used to assess α1 protein levels. Results Compared to controls, knockin mice displayed decreased AFT and chronic tolerance to ethanol-induced motor ataxia, and also displayed heightened ethanol-withdrawal hyperexcitability. No differences between wildtype and knockin mice were seen in other ethanol-induced behavioral measures. Following chronic exposure to ethanol, control mice displayed reductions in α1 protein levels, but knockins did not. Conclusions We conclude that α1-GABAA-Rs play a role in tolerance to ethanol-induced motor ataxia and withdrawal-related hyperexcitability. However, other aspects of behavioral tolerance and physical dependence do not rely on α1-containing GABAA-Rs. PMID:19032579

Chronic hyperprolactinemia evoked by disruption of lactotrope dopamine D2 receptors impacts on liver and adipocyte genes related to glucose and insulin balance.

PubMed

Luque, Guillermina María; Lopez-Vicchi, Felicitas; Ornstein, Ana María; Brie, Belén; De Winne, Catalina; Fiore, Esteban; Perez-Millan, Maria Inés; Mazzolini, Guillermo; Rubinstein, Marcelo; Becu-Villalobos, Damasia

2016-12-01

We studied the impact of high prolactin titers on liver and adipocyte gene expression related to glucose and insulin homeostasis in correlation with obesity onset. To that end we used mutant female mice that selectively lack dopamine type 2 receptors (D2Rs) from pituitary lactotropes (lacDrd2KO), which have chronic high prolactin levels associated with increased body weight, marked increments in fat depots, adipocyte size, and serum lipids, and a metabolic phenotype that intensifies with age. LacDrd2KO mice of two developmental ages, 5 and 10 mo, were used. In the first time point, obesity and increased body weight are marginal, although mice are hyperprolactinemic, whereas at 10 mo there is marked adiposity with a 136% increase in gonadal fat and a 36% increase in liver weight due to lipid accumulation. LacDrd2KO mice had glucose intolerance, hyperinsulinemia, and impaired insulin response to glucose already in the early stages of obesity, but changes in liver and adipose tissue transcription factors were time and tissue dependent. In chronic hyperprolactinemic mice liver Prlr were upregulated, there was liver steatosis, altered expression of the lipogenic transcription factor Chrebp, and blunted response of Srebp-1c to refeeding at 5 mo of age, whereas no effect was observed in the glycogenesis pathway. On the other hand, in adipose tissue a marked decrease in lipogenic transcription factor expression was observed when morbid obesity was already settled. These adaptive changes underscore the role of prolactin signaling in different tissues to promote energy storage. Copyright © 2016 the American Physiological Society.

Regulation of bitter taste responses by tumor necrosis factor.

PubMed

Feng, Pu; Jyotaki, Masafumi; Kim, Agnes; Chai, Jinghua; Simon, Nirvine; Zhou, Minliang; Bachmanov, Alexander A; Huang, Liquan; Wang, Hong

2015-10-01

Inflammatory cytokines are important regulators of metabolism and food intake. Over production of inflammatory cytokines during bacterial and viral infections leads to anorexia and reduced food intake. However, it remains unclear whether any inflammatory cytokines are involved in the regulation of taste reception, the sensory mechanism governing food intake. Previously, we showed that tumor necrosis factor (TNF), a potent proinflammatory cytokine, is preferentially expressed in a subset of taste bud cells. The level of TNF in taste cells can be further induced by inflammatory stimuli. To investigate whether TNF plays a role in regulating taste responses, in this study, we performed taste behavioral tests and gustatory nerve recordings in TNF knockout mice. Behavioral tests showed that TNF-deficient mice are significantly less sensitive to the bitter compound quinine than wild-type mice, while their responses to sweet, umami, salty, and sour compounds are comparable to those of wild-type controls. Furthermore, nerve recording experiments showed that the chorda tympani nerve in TNF knockout mice is much less responsive to bitter compounds than that in wild-type mice. Chorda tympani nerve responses to sweet, umami, salty, and sour compounds are similar between TNF knockout and wild-type mice, consistent with the results from behavioral tests. We further showed that taste bud cells express the two known TNF receptors TNFR1 and TNFR2 and, therefore, are potential targets of TNF. Together, our results suggest that TNF signaling preferentially modulates bitter taste responses. This mechanism may contribute to taste dysfunction, particularly taste distortion, associated with infections and some chronic inflammatory diseases. Copyright © 2015 Elsevier Inc. All rights reserved.

Regulation of bitter taste responses by tumor necrosis factor

PubMed Central

Feng, Pu; Jyotaki, Masafumi; Kim, Agnes; Chai, Jinghua; Simon, Nirvine; Zhou, Minliang; Bachmanov, Alexander A.; Huang, Liquan; Wang, Hong

2015-01-01

Inflammatory cytokines are important regulators of metabolism and food intake. Over production of inflammatory cytokines during bacterial and viral infections leads to anorexia and reduced food intake. However, it remains unclear whether any inflammatory cytokines are involved in the regulation of taste reception, the sensory mechanism governing food intake. Previously, we showed that tumor necrosis factor (TNF), a potent proinflammatory cytokine, is preferentially expressed in a subset of taste bud cells. The level of TNF in taste cells can be further induced by inflammatory stimuli. To investigate whether TNF plays a role in regulating taste responses, in this study, we performed taste behavioral tests and gustatory nerve recordings in TNF knockout mice. Behavioral tests showed that TNF-deficient mice are significantly less sensitive to the bitter compound quinine than wild-type mice, while their responses to sweet, umami, salty, and sour compounds are comparable to those of wild-type controls. Furthermore, nerve recording experiments showed that the chorda tympani nerve in TNF knockout mice is much less responsive to bitter compounds than that in wild-type mice. Chorda tympani nerve responses to sweet, umami, salty, and sour compounds are similar between TNF knockout and wild-type mice, consistent with the results from behavioral tests. We further showed that taste bud cells express the two known TNF receptors TNFR1 and TNFR2 and, therefore, are potential targets of TNF. Together, our results suggest that TNF signaling preferentially modulates bitter taste responses. This mechanism may contribute to taste dysfunction, particularly taste distortion, associated with infections and some chronic inflammatory diseases. PMID:25911043

An immunohistochemistry-based study on aquaporin (AQP)-1, 3, 4, 5 and 8 in the parotid glands, submandibular glands and sublingual glands of Sjögren's syndrome mouse models chronically administered cevimeline.

PubMed

Nakamura, Moriyoshi; Saga, Tsuyoshi; Watanabe, Koichi; Takahashi, Nagahiro; Tabira, Yoko; Kusukawa, Jingo; Yamaki, Koh-Ichi

2013-01-01

Cevimeline is a muscarinic agonist that promotes saliva secretion and is used to treat Sjögren's syndrome (SS), an autoimmune disorder in which the exocrine glands that produce saliva are destroyed. Cevimeline is thought to affect the composition of saliva in part by regulating the localization of aquaporins (AQPs). In this study, we investigated the effects of chronic Cevimeline administration in the salivary glands of SS mice on the immunohistochemical localization of aquaporin (AQP)-1, 3, 4, 5 and 8. We used Cevimeline-untreated SS mice, treated SS mice, discontinued SS mice and untreated normal mice. AQP-5 was found in the apical and lateral membranes of acinar cells in the parotid and submandibular glands of cevimeline-treated SS mice and untreated normal mice. Saliva secretion and AQP-5 localization were sustained in SS mice who were chronically administered Cevimeline and at four weeks after discontinuation. Unlike AQP-5, the localization of AQP-1, 3, 4 and 8 were not affected by Cevimeline administration. Our findings demonstrated that administration of Cevimeline maintains the proper localization of AQP-5 in the acinar cells of the salivary gland, which may promote salivation in chronically treated SS mice. Clinically, this suggests that chronic Cevimeline administration may be useful therapeutically for SS patients suffering from a decrease in saliva secretion by improving the disordered AQP-5 localization.

Oligodendrocytes and Progenitors Become Progressively Depleted within Chronically Demyelinated Lesions

PubMed Central

Mason, Jeffrey L.; Toews, Arrel; Hostettler, Janell D.; Morell, Pierre; Suzuki, Kinuko; Goldman, James E.; Matsushima, Glenn K.

2004-01-01

To understand mechanisms that may underlie the progression of a demyelinated lesion to a chronic state, we have used the cuprizone model of chronic demyelination. In this study, we investigated the fate of oligodendrocytes during the progression of a demyelinating lesion to a chronic state and determined whether transplanted adult oligodendrocyte progenitors could remyelinate the chronically demyelinated axons. Although there is rapid regeneration of the oligodendrocyte population following an acute lesion, most of these newly regenerated cells undergo apoptosis if mice remain on a cuprizone diet. Furthermore, the oligodendrocyte progenitors also become progressively depleted within the lesion, which appears to contribute to the chronic demyelination. Interestingly, even if the mice are returned to a normal diet following 12 weeks of exposure to cuprizone, remyelination and oligodendrocyte regeneration does not occur. However, if adult O4+ progenitors are transplanted into the chronically demyelinated lesion of mice treated with cuprizone for 12 weeks, mature oligodendrocyte regeneration and remyelination occurs after the mice are returned to a normal diet. Thus, the formation of chronically demyelinated lesions induced by cuprizone appears to be the result of oligodendrocyte depletion within the lesion and not due to the inability of the chronically demyelinated axons to be remyelinated. PMID:15111314

Effects of Cholinergic Stimulation with Pyridostigmine Bromide on Chronic Chagasic Cardiomyopathic Mice

PubMed Central

de Cuba, Marília Beatriz; Ribeiro Machado, Marcus Paulo; Farnesi, Thais Soares; Alves, Angelica Cristina; Martins, Livia Alves; de Oliveira, Lucas Felipe; Capitelli, Caroline Santos; Leite, Camila Ferreira; Vinícius Silva, Marcos; Machado, Juliana Reis; Kappel, Henrique Borges; Sales de Campos, Helioswilton; Paiva, Luciano; da Silva Gomes, Natália Lins; Guimarães Faleiros, Ana Carolina; Britto, Constança Felicia de Paoli de Carvalho; Savino, Wilson; Moreira, Otacílio Cruz; Rodrigues Jr., Virmondes; Montano, Nicola; Lages-Silva, Eliane; Ramirez, Luis Eduardo; Dias da Silva, Valdo Jose

2014-01-01

The aim of the present study was to assess the effects of an anticholinesterase agent, pyridostigmine bromide (Pyrido), on experimental chronic Chagas heart disease in mice. To this end, male C57BL/6J mice noninfected (control:Con) or chronically infected (5 months) with Trypanosoma cruzi (chagasic:Chg) were treated or not (NT) with Pyrido for one month. At the end of this period, electrocardiogram (ECG); cardiac autonomic function; heart histopathology; serum cytokines; and the presence of blood and tissue parasites by means of immunohistochemistry and PCR were assessed. In NT-Chg mice, significant changes in the electrocardiographic, autonomic, and cardiac histopathological profiles were observed confirming a chronic inflammatory response. Treatment with Pyrido in Chagasic mice caused a significant reduction of myocardial inflammatory infiltration, fibrosis, and hypertrophy, which was accompanied by a decrease in serum levels of IFNγ with no change in IL-10 levels, suggesting a shift of immune response toward an anti-inflammatory profile. Lower nondifferent numbers of parasite DNA copies were observed in both treated and nontreated chagasic mice. In conclusion, our findings confirm the marked neuroimmunomodulatory role played by the parasympathetic autonomic nervous system in the evolution of the inflammatory-immune response to T. cruzi during experimental chronic Chagas heart disease in mice. PMID:25221388

Effects of cholinergic stimulation with pyridostigmine bromide on chronic chagasic cardiomyopathic mice.

PubMed

de Cuba, Marília Beatriz; Machado, Marcus Paulo Ribeiro; Farnesi, Thais Soares; Alves, Angelica Cristina; Martins, Livia Alves; de Oliveira, Lucas Felipe; Capitelli, Caroline Santos; Leite, Camila Ferreira; Silva, Marcos Vinícius; Machado, Juliana Reis; Kappel, Henrique Borges; de Campos, Helioswilton Sales; Paiva, Luciano; Gomes, Natália Lins da Silva; Faleiros, Ana Carolina Guimarães; Britto, Constança Felicia de Paoli de Carvalho; Savino, Wilson; Moreira, Otacílio Cruz; Rodrigues, Virmondes; Montano, Nicola; Lages-Silva, Eliane; Ramirez, Luis Eduardo; da Silva, Valdo Jose Dias

2014-01-01

The aim of the present study was to assess the effects of an anticholinesterase agent, pyridostigmine bromide (Pyrido), on experimental chronic Chagas heart disease in mice. To this end, male C57BL/6J mice noninfected (control:Con) or chronically infected (5 months) with Trypanosoma cruzi (chagasic:Chg) were treated or not (NT) with Pyrido for one month. At the end of this period, electrocardiogram (ECG); cardiac autonomic function; heart histopathology; serum cytokines; and the presence of blood and tissue parasites by means of immunohistochemistry and PCR were assessed. In NT-Chg mice, significant changes in the electrocardiographic, autonomic, and cardiac histopathological profiles were observed confirming a chronic inflammatory response. Treatment with Pyrido in Chagasic mice caused a significant reduction of myocardial inflammatory infiltration, fibrosis, and hypertrophy, which was accompanied by a decrease in serum levels of IFNγ with no change in IL-10 levels, suggesting a shift of immune response toward an anti-inflammatory profile. Lower nondifferent numbers of parasite DNA copies were observed in both treated and nontreated chagasic mice. In conclusion, our findings confirm the marked neuroimmunomodulatory role played by the parasympathetic autonomic nervous system in the evolution of the inflammatory-immune response to T. cruzi during experimental chronic Chagas heart disease in mice.

Mice with ablated adult brain neurogenesis are not impaired in antidepressant response to chronic fluoxetine.

PubMed

Jedynak, Paulina; Kos, Tomasz; Sandi, Carmen; Kaczmarek, Leszek; Filipkowski, Robert K

2014-09-01

The neurogenesis hypothesis of major depression has two main facets. One states that the illness results from decreased neurogenesis while the other claims that the very functioning of antidepressants depends on increased neurogenesis. In order to verify the latter, we have used cyclin D2 knockout mice (cD2 KO mice), known to have virtually no adult brain neurogenesis, and we demonstrate that these mice successfully respond to chronic fluoxetine. After unpredictable chronic mild stress, mutant mice showed depression-like behavior in forced swim test, which was eliminated with chronic fluoxetine treatment, despite its lack of impact on adult hippocampal neurogenesis in cD2 KO mice. Our results suggest that new neurons are not indispensable for the action of antidepressants such as fluoxetine. Using forced swim test and tail suspension test, we also did not observe depression-like behavior in control cD2 KO mice, which argues against the link between decreased adult brain neurogenesis and major depression. Copyright © 2014 Elsevier Ltd. All rights reserved.

Nest building is a novel method for indexing severity of alcohol withdrawal in mice.

PubMed

Greenberg, G D; Huang, L C; Spence, S E; Schlumbohm, J P; Metten, P; Ozburn, A R; Crabbe, J C

2016-04-01

Withdrawal after chronic ethanol (EtOH) affects body temperature, goal-directed behavior and motor function in mice and increases general central nervous system excitability. Nest-building tests have been used to assay these states but to this point have not been employed as measures of EtOH withdrawal severity. We first refined nest-scoring methods using a genetically heterogeneous stock of mice (HS/Npt). Mice were then made physically dependent following three days of chronic EtOH vapor inhalation to produce average blood EtOH concentrations (BECs) of 1.89 mg/mL. EtOH withdrawal affected the progression of nest building over time when mice were tested 2-4 days after removal from three days of chronic exposure to EtOH. In a separate group of mice, chronic EtOH vapor inhalation (BECs 1.84 mg/mL) suppressed nest building over days 1-2 but not days 2-3 of withdrawal. In a following experiment, EtOH withdrawal dose-dependently slowed recovery of nest building for up to 32 h. Finally, we determined that long-lasting nest-building deficits extend to mice undergoing withdrawal from a high dose (4 g/kg) of acute EtOH. Sex differences for nest building were absent following EtOH exposure. In mice naïve to EtOH treatments, male mice had lower pre-test body temperatures and increased nest scores across a two-day testing period compared to females. These results suggest that nest building can be used to assess chronic and acute EtOH withdrawal severity in mice. Published by Elsevier B.V.

Essential role of interleukin-6 in post-stroke angiogenesis

PubMed Central

Gertz, Karen; Kronenberg, Golo; Kälin, Roland E.; Baldinger, Tina; Werner, Christian; Balkaya, Mustafa; Eom, Gina D.; Hellmann-Regen, Julian; Kröber, Jan; Miller, Kelly R.; Lindauer, Ute; Laufs, Ulrich; Dirnagl, Ulrich; Heppner, Frank L.

2012-01-01

Ambivalent effects of interleukin-6 on the pathogenesis of ischaemic stroke have been reported. However, to date, the long-term actions of interleukin-6 after stroke have not been investigated. Here, we subjected interleukin-6 knockout (IL-6−/−) and wild-type control mice to mild brain ischaemia by 30-min filamentous middle cerebral artery occlusion/reperfusion. While ischaemic tissue damage was comparable at early time points, IL-6−/− mice showed significantly increased chronic lesion volumes as well as worse long-term functional outcome. In particular, IL-6−/− mice displayed an impaired angiogenic response to brain ischaemia with reduced numbers of newly generated endothelial cells and decreased density of perfused microvessels along with lower absolute regional cerebral blood flow and reduced vessel responsivity in ischaemic striatum at 4 weeks. Similarly, the early genomic activation of angiogenesis-related gene networks was strongly reduced and the ischaemia-induced signal transducer and activator of transcription 3 activation observed in wild-type mice was almost absent in IL-6−/− mice. In addition, systemic neoangiogenesis was impaired in IL-6−/− mice. Transplantation of interleukin-6 competent bone marrow into IL-6−/− mice (IL-6chi) did not rescue interleukin-6 messenger RNA expression or the early transcriptional activation of angiogenesis after stroke. Accordingly, chronic stroke outcome in IL-6chi mice recapitulated the major effects of interleukin-6 deficiency on post-stroke regeneration with significantly enhanced lesion volumes and reduced vessel densities. Additional in vitro experiments yielded complementary evidence, which showed that after stroke resident brain cells serve as the major source of interleukin-6 in a self-amplifying network. Treatment of primary cortical neurons, mixed glial cultures or immortalized brain endothelia with interleukin 6-induced robust interleukin-6 messenger RNA transcription in each case, whereas oxygen–glucose deprivation did not. However, oxygen–glucose deprivation of organotypic brain slices resulted in strong upregulation of interleukin-6 messenger RNA along with increased transcription of key angiogenesis-associated genes. In conclusion, interleukin-6 produced locally by resident brain cells promotes post-stroke angiogenesis and thereby affords long-term histological and functional protection. PMID:22492561

Characterisation of colonic dysplasia-like epithelial atypia in murine colitis

PubMed Central

Randall-Demllo, Sarron; Fernando, Ruchira; Brain, Terry; Sohal, Sukhwinder Singh; Cook, Anthony L; Guven, Nuri; Kunde, Dale; Spring, Kevin; Eri, Rajaraman

2016-01-01

AIM To determine if exacerbation of pre-existing chronic colitis in Winnie (Muc2 mutant) mice induces colonic dysplasia. METHODS Winnie mice and C57BL6 as a genotype control, were administered 1% w/v dextran sulphate sodium (DSS) orally, followed by drinking water alone in week-long cycles for a total of three cycles. After the third cycle, mice were killed and colonic tissue collected for histological and immunohistochemical evaluation. Inflammation and severity of dysplasia in the colonic mucosa were assessed in H&E sections of the colon. Epithelial cell proliferation was assessed using Ki67 and aberrant β-catenin signalling assessed with enzyme-based immunohistochemistry. Extracted RNA from colonic segments was used for the analysis of gene expression using real-time quantitative PCR. Finally, the distribution of Cxcl5 was visualised using immunohistochemistry. RESULTS Compared to controls, Winnie mice exposed to three cycles of DSS displayed inflammation mostly confined to the distal-mid colon with extensive mucosal hyperplasia and regenerative atypia resembling epithelial dysplasia. Dysplasia-like changes were observed in 100% of Winnie mice exposed to DSS, with 55% of these animals displaying changes similar to high-grade dysplasia, whereas high-grade changes were absent in wild-type mice. Occasional penetration of the muscularis mucosae by atypical crypts was observed in 27% of Winnie mice after DSS. Atypical crypts however displayed no evidence of oncogenic nuclear β-catenin accumulation, regardless of histological severity. Expression of Cav1, Trp53 was differentially regulated in the distal colon of Winnie relative to wild-type mice. Expression of Myc and Ccl5 was increased by DSS treatment in Winnie only. Furthermore, increased Ccl5 expression correlated with increased complexity in abnormal crypts. While no overall difference in Cxcl5 mucosal expression was observed between treatment groups, epithelial Cxcl5 protein appeared to be diminished in the atypical epithelium. CONCLUSION Alterations to the expression of Cav1, Ccl5, Myc and Trp53 in the chronically inflamed Winnie colon may influence the transition to dysplasia. PMID:27729740

Improve T Cell Therapy in Neuroblastoma

DTIC Science & Technology

2013-07-01

ear, and spleen of treated mice. Control mice showed evidence of chronic dermatitis , with moderate diffuse epithelial hyperplasia, hyperkeratosis and...treated mice. Control mice showed evidence of chronic dermatitis , with moderate diffuse epithelial hyperplasia, hyperkeratosis and marked multi- focal...in question to contact us about making the changes. Please note, however, that the manuscript would be held from further processing until this issue

Effects of the glucagon-like polypeptide-1 analogue (Val8)GLP-1 on learning, progenitor cell proliferation and neurogenesis in the C57B/16 mouse brain.

PubMed

McGovern, Stephen F J; Hunter, Kerry; Hölscher, Christian

2012-09-14

Type 2 diabetes (T2DM) has been identified as a risk factor for Alzheimer's disease. Here, we tested the properties of the glucagon-like polypetide-1 (GLP-1) analogue (Val8)GLP-1, a drug originally developed as a treatment for T2DM at a range of doses (2.5 nmol; 25 nmol; 100 nmol; or 250 nmol/kg bw ip.) in an acute memory study in wild type C57B/l6 mice. We also tested (Val8)GLP-1 and the GLP-1 receptor antagonist exendin (9-39) in a chronic study (3 weeks at 25 nmol/kg bw ip. once-daily). We found that (Val8)GLP-1 crossed the blood brain barrier readily and that peripheral injection increased levels in the brain 30 min post-injection ip. but not 2h post-injection in rats. In the acute study, the low dose of 2.5 nmol/kg ip. enhanced motor activity in the open field task, while total distance travelled, exploratory behaviour and anxiety was not affected at any dose. Learning an object recognition task was not affected either. In the chronic study, no effect was observed in the open field assessment. The antagonist exendin (9-39) impaired object recognition learning and spatial learning in a water maze task, demonstrating the importance of GLP-1 signalling in memory formation. Locomotor activity was also affected in some cases. Blood sugar levels and insulin sensitivity was not affected in chronically treated mice. Neuronal stem cells and neurogenesis was enhanced by (Val8)GLP-1 in the dentate gyrus of wild type mice. The results demonstrate that (Val8)GLP-1 is safe in a range of doses, crosses the BBB and has potentially beneficial effects in the CNS by enhancing neurogenesis. Copyright © 2012 Elsevier B.V. All rights reserved.

Endoplasmic Reticulum Stress-induced Hepatocellular Death Pathways Mediate Liver Injury and Fibrosis via Stimulator of Interferon Genes*

PubMed Central

Iracheta-Vellve, Arvin; Petrasek, Jan; Gyongyosi, Benedek; Satishchandran, Abhishek; Lowe, Patrick; Kodys, Karen; Catalano, Donna; Calenda, Charles D.; Kurt-Jones, Evelyn A.; Fitzgerald, Katherine A.; Szabo, Gyongyi

2016-01-01

Fibrosis, driven by inflammation, marks the transition from benign to progressive stages of chronic liver diseases. Although inflammation promotes fibrogenesis, it is not known whether other events, such as hepatocyte death, are required for the development of fibrosis. Interferon regulatory factor 3 (IRF3) regulates hepatocyte apoptosis and production of type I IFNs. In the liver, IRF3 is activated via Toll-like receptor 4 (TLR4) signaling or the endoplasmic reticulum (ER) adapter, stimulator of interferon genes (STING). We hypothesized that IRF3-mediated hepatocyte death is an independent determinant of chemically induced liver fibrogenesis. To test this, we performed acute or chronic CCl4 administration to WT and IRF3-, Toll/Interleukin-1R (TIR) domain-containing adapter-inducing interferon-β (TRIF)-, TRIF-related adaptor molecule (TRAM)-, and STING-deficient mice. We report that acute CCl4 administration to WT mice resulted in early ER stress, activation of IRF3, and type I IFNs, followed by hepatocyte apoptosis and liver injury, accompanied by liver fibrosis upon repeated administration of CCl4. Deficiency of IRF3 or STING prevented hepatocyte death and fibrosis both in acute or chronic CCl4. In contrast, mice deficient in type I IFN receptors or in TLR4 signaling adaptors, TRAM or TRIF, upstream of IRF3, were not protected from hepatocyte death and/or fibrosis, suggesting that the pro-apoptotic role of IRF3 is independent of TLR signaling in fibrosis. Hepatocyte death is required for liver fibrosis with causal involvement of STING and IRF3. Thus, our results identify that IRF3, by its association with STING in the presence of ER stress, couples hepatocyte apoptosis with liver fibrosis and indicate that innate immune signaling regulates outcomes of liver fibrosis via modulation of hepatocyte death in the liver. PMID:27810900

Late stage erythroid precursor production is impaired in mice with chronic inflammation.

PubMed

Prince, Olivier D; Langdon, Jacqueline M; Layman, Andrew J; Prince, Ian C; Sabogal, Miguel; Mak, Howard H; Berger, Alan E; Cheadle, Chris; Chrest, Francis J; Yu, Qilu; Andrews, Nancy C; Xue, Qian-Li; Civin, Curt I; Walston, Jeremy D; Roy, Cindy N

2012-11-01

We and others have shown previously that over-expression of hepcidin antimicrobial peptide, independently of inflammation, induces several features of anemia of inflammation and chronic disease, including hypoferremia, sequestration of iron stores and iron-restricted erythropoiesis. Because the iron-restricted erythropoiesis evident in hepcidin transgenic mice differs from the normocytic, normochromic anemia most often observed in anemia of inflammation, we tested the hypothesis that chronic inflammation may contribute additional features to anemia of inflammation which continue to impair erythropoiesis following the acute phase of inflammation in which hepcidin is active. We compared erythropoiesis and iron handling in mice with turpentine-induced sterile abscesses with erythropoiesis and iron handling in hepcidin transgenic mice. We compared erythrocyte indices, expression of genes in the hepcidin regulatory pathway, tissue iron distribution, expression of heme and iron transport genes in splenic macrophages, the phenotype of erythroid maturation and chloromethyl dichlorodihydrofluorescein diacetate, acetyl ester fluorescence. Mice with sterile abscesses exhibited an intense, acute inflammatory phase followed by a mild to moderate chronic inflammatory phase. We found that erythrocytes in mice with sterile abscesses were normocytic and normochromic in contrast to those in hepcidin transgenic mice. We also observed that although hypoferremia resolved in the late phases of inflammation, erythropoiesis remained suppressed, with evidence of inefficient maturation of erythroid precursors in the bone marrow of mice with sterile abscesses. Finally, we observed increased oxidative stress in erythroid progenitors and circulating erythrocytes of mice with sterile abscesses which was not evident in hepcidin transgenic mice. Our results suggest that chronic inflammation inhibits late stages of erythroid production in the turpentine-induced sterile abscess model and induces features of impaired erythropoiesis which are distinct from those in hepcidin transgenic mice.

Late stage erythroid precursor production is impaired in mice with chronic inflammation

PubMed Central

Prince, Olivier D.; Langdon, Jacqueline M.; Layman, Andrew J.; Prince, Ian C.; Sabogal, Miguel; Mak, Howard H.; Berger, Alan E.; Cheadle, Chris; Chrest, Francis J.; Yu, Qilu; Andrews, Nancy C.; Xue, Qian-Li; Civin, Curt I.; Walston, Jeremy D.; Roy, Cindy N.

2012-01-01

Background We and others have shown previously that over-expression of hepcidin antimicrobial peptide, independently of inflammation, induces several features of anemia of inflammation and chronic disease, including hypoferremia, sequestration of iron stores and iron-restricted erythropoiesis. Because the iron-restricted erythropoiesis evident in hepcidin transgenic mice differs from the normocytic, normochromic anemia most often observed in anemia of inflammation, we tested the hypothesis that chronic inflammation may contribute additional features to anemia of inflammation which continue to impair erythropoiesis following the acute phase of inflammation in which hepcidin is active. Design and Methods We compared erythropoiesis and iron handling in mice with turpentine-induced sterile abscesses with erythropoiesis and iron handling in hepcidin transgenic mice. We compared erythrocyte indices, expression of genes in the hepcidin regulatory pathway, tissue iron distribution, expression of heme and iron transport genes in splenic macrophages, the phenotype of erythroid maturation and chloromethyl dichlorodihydrofluorescein diacetate, acetyl ester fluorescence. Results Mice with sterile abscesses exhibited an intense, acute inflammatory phase followed by a mild to moderate chronic inflammatory phase. We found that erythrocytes in mice with sterile abscesses were normocytic and normochromic in contrast to those in hepcidin transgenic mice. We also observed that although hypoferremia resolved in the late phases of inflammation, erythropoiesis remained suppressed, with evidence of inefficient maturation of erythroid precursors in the bone marrow of mice with sterile abscesses. Finally, we observed increased oxidative stress in erythroid progenitors and circulating erythrocytes of mice with sterile abscesses which was not evident in hepcidin transgenic mice. Conclusions Our results suggest that chronic inflammation inhibits late stages of erythroid production in the turpentine-induced sterile abscess model and induces features of impaired erythropoiesis which are distinct from those in hepcidin transgenic mice. PMID:22581006

Pseudomonas aeruginosa biofilm aggravates skin inflammatory response in BALB/c mice in a novel chronic wound model.

PubMed

Trøstrup, Hannah; Thomsen, Kim; Christophersen, Lars J; Hougen, Hans P; Bjarnsholt, Thomas; Jensen, Peter Ø; Kirkby, Nikolai; Calum, Henrik; Høiby, Niels; Moser, Claus

2013-01-01

Chronic wounds are presumed to persist in the inflammatory state, preventing healing. Emerging evidence indicates a clinical impact of bacterial biofilms in soft tissues, including Pseudomonas aeruginosa (PA) biofilms. To further investigate this, we developed a chronic PA biofilm wound infection model in C3H/HeN and BALB/c mice. The chronic wound was established by an injection of seaweed alginate-embedded P. aeruginosa PAO1 beneath a third-degree thermal lesion providing full thickness skin necrosis, as in human chronic wounds. Cultures revealed growth of PA, and both alginate with or without PAO1 generated a polymorphonuclear-dominated inflammation early after infection. However, both at days 4 and 7, there were a more acute polymorphonuclear-dominated and higher degree of inflammation in the PAO1 containing group (p < 0.05). Furthermore, PNA-FISH and supplemented DAPI staining showed bacteria organized in clusters, resembling biofilms, and inflammation located adjacent to the PA. The chronic wound infection showed a higher number of PAO1 in the BALB/c mice at day 4 after infection as compared to C3H/HeN mice (p < 0.006). In addition, a higher concentration of interleukin-1beta in the chronic wounds of BALB/c mice was observed at day 7 (p < 0.02), despite a similar number of bacteria in the two mouse strains. The present study succeeded in establishing a chronic PA biofilm infection in mice. The results showed an aggravating impact of local inflammation induced by PA biofilms. In conclusion, our findings indicate that improved infection control of chronic wounds reduces the inflammatory response and may improve healing. © 2013 by the Wound Healing Society.

Transferrin Receptor 1 in Chronic Hypoxia-Induced Pulmonary Vascular Remodeling.

PubMed

Naito, Yoshiro; Hosokawa, Manami; Sawada, Hisashi; Oboshi, Makiko; Hirotani, Shinichi; Iwasaku, Toshihiro; Okuhara, Yoshitaka; Morisawa, Daisuke; Eguchi, Akiyo; Nishimura, Koichi; Soyama, Yuko; Fujii, Kenichi; Mano, Toshiaki; Ishihara, Masaharu; Tsujino, Takeshi; Masuyama, Tohru

2016-06-01

Iron is associated with the pathophysiology of several cardiovascular diseases, including pulmonary hypertension (PH). In addition, disrupted pulmonary iron homeostasis has been reported in several chronic lung diseases. Transferrin receptor 1 (TfR1) plays a key role in cellular iron transport. However, the role of TfR1 in the pathophysiology of PH has not been well characterized. In this study, we investigate the role of TfR1 in the development of hypoxia-induced pulmonary vascular remodeling. PH was induced by exposing wild-type (WT) mice and TfR1 hetero knockout mice to hypoxia for 4 weeks and evaluated via assessment of pulmonary vascular remodeling, right ventricular (RV) systolic pressure, and RV hypertrophy. In addition, we assessed the functional role of TfR1 in pulmonary artery smooth muscle cells in vitro. The morphology of pulmonary arteries did not differ between WT mice and TfR1 hetero knockout mice under normoxic conditions. In contrast, TfR1 hetero knockout mice exposed to 4 weeks hypoxia showed attenuated pulmonary vascular remodeling, RV systolic pressure, and RV hypertrophy compared with WT mice. In addition, the depletion of TfR1 by RNA interference attenuated human pulmonary artery smooth muscle cells proliferation induced by platelet-derived growth factor-BB (PDGF-BB) in vitro. These results suggest that TfR1 plays an important role in the development of hypoxia-induced pulmonary vascular remodeling. © American Journal of Hypertension, Ltd 2015. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Chronic plus binge ethanol exposure causes more severe pancreatic injury and inflammation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ren, Zhenhua

Alcohol abuse increases the risk for pancreatitis. The pattern of alcohol drinking may impact its effect. We tested a hypothesis that chronic ethanol consumption in combination with binge exposure imposes more severe damage to the pancreas. C57BL/6 mice were divided into four groups: control, chronic ethanol exposure, binge ethanol exposure and chronic plus binge ethanol exposure. For the control group, mice were fed with a liquid diet for two weeks. For the chronic ethanol exposure group, mice were fed with a liquid diet containing 5% ethanol for two weeks. In the binge ethanol exposure group, mice were treated with ethanolmore » by gavage (5 g/kg, 25% ethanol w/v) daily for 3 days. For the chronic plus binge exposure group, mice were fed with a liquid diet containing 5% ethanol for two weeks and exposed to ethanol by gavage during the last 3 days. Chronic and binge exposure alone caused minimal pancreatic injury. However, chronic plus binge ethanol exposure induced significant apoptotic cell death. Chronic plus binge ethanol exposure altered the levels of alpha-amylase, glucose and insulin. Chronic plus binge ethanol exposure caused pancreatic inflammation which was shown by the macrophages infiltration and the increase of cytokines and chemokines. Chronic plus binge ethanol exposure increased the expression of ADH1 and CYP2E1. It also induced endoplasmic reticulum stress which was demonstrated by the unfolded protein response. In addition, chronic plus binge ethanol exposure increased protein oxidation and lipid peroxidation, indicating oxidative stress. Therefore, chronic plus binge ethanol exposure is more detrimental to the pancreas. - Highlights: • Chronic plus binge alcohol drinking causes more pancreatic injury. • Chronic plus binge alcohol drinking induces more pancreatic inflammation. • Chronic plus binge alcohol causes more endoplasmic reticulum stress and oxidative stress.« less

Chronic social isolation and chronic variable stress during early development induce later elevated ethanol intake in adult C57BL/6J mice.

PubMed

Lopez, Marcelo F; Doremus-Fitzwater, Tamara L; Becker, Howard C

2011-06-01

Experience with stress situations during early development can have long-lasting effects on stress- and anxiety-related behaviors. Importantly, this can also favor drug self-administration. These studies examined the effects of chronic social isolation and/or variable stress experiences during early development on subsequent voluntary ethanol intake in adult male and female C57BL/6J mice. The experiments were conducted to evaluate the effect of chronic isolation between weaning and adulthood (Experiment 1), chronic isolation during adulthood (Experiment 2), and chronic variable stress (CVS) alone or in combination with chronic social isolation between weaning and adulthood (Experiment 3) on subsequent voluntary ethanol intake. Mice were born in our facility and were separated into two housing conditions: isolate housed (one mouse/cage) or group housed (four mice/cage) according to sex. Separate groups were isolated for 40 days starting either at time of weaning postnatal day 21 (PD 21) (early isolation, Experiments 1 and 3) or at adulthood (PD 60: late isolation, Experiment 2). The effects of housing condition on subsequent ethanol intake were assessed starting at around PD 65 in Experiments 1 and 3 or PD 105 days in Experiment 2. In Experiment 3, starting at PD 32, isolate-housed and group-housed mice were either subjected to CVS or left undisturbed. CVS groups experienced random presentations of mild stressors for 14 days, including exposure to an unfamiliar open field, restraint, physical shaking, and forced swim, among others. All mice were tested for ethanol intake for 14 days using a two-bottle choice (ethanol 15% vol/vol vs. water) for a 2-h limited access procedure. Early social isolation resulted in greater ethanol intake compared with the corresponding group-housed mice (Experiment 1). In contrast, social isolation during adulthood (late isolation) did not increase subsequent ethanol intake compared with the corresponding group-housed mice (Experiment 2). For mice that did not experience CVS, early social isolation resulted in greater ethanol intake compared with group-housed mice (Experiment 3). CVS subsequently resulted in a significant increase in ethanol intake in group-housed mice, but CVS failed to further increase ethanol intake in mice that experienced chronic social isolation early in life (Experiment 3). Overall, female mice consumed more ethanol than males, whether isolated (early or late) or group housed. These results indicate that early but not late social isolation can subsequently influence ethanol consumption in C57BL/6J mice. Thus, the developmental timing of chronic social isolation appears to be an important factor in defining later effects on ethanol self-administration behavior. In addition, experience with CVS early in life results in elevated ethanol intake later in adulthood. Taken together, these results emphasize the important role of early stress experiences that modulate later voluntary ethanol intake during adulthood. Copyright © 2011 Elsevier Inc. All rights reserved.

Exposure to a Mycobacterial Antigen, ESAT-6, Exacerbates Granulomatous and Fibrotic Changes in a Multiwall Carbon Nanotube Model of Chronic Pulmonary Disease

PubMed Central

Malur, Anagha; Barna, Barbara P; Patel, Janki; McPeek, Matthew; Wingard, Christopher J; Dobbs, Larry; Thomassen, Mary Jane

2016-01-01

Recent studies suggest additive effects of environmental pollutants and microbial antigens on respiratory disease. We established a granuloma model in which instilled multiwall carbon nanotubes (MWCNT) elicit granulomatous pathology. We hypothesized that mycobacterial antigen ESAT-6, a T cell activator associated with tuberculosis and sarcoidosis, might alter pathology. Wild-type C57Bl/6 mice received MWCNT with or without ESAT-6 peptide. Controls received vehicle (surfactant-PBS) or ESAT-6 alone. Mice were evaluated 60 days later for granulomas, fibrosis, and bronchoalveolar lavage (BAL) cell expression of inflammatory mediators (CCL2, MMP-12, and Osteopontin). Results indicated increased granulomas, fibrosis, and inflammatory mediators in mice receiving the combination of MWCNT+ESAT-6 compared to MWCNT or vehicle alone. ESAT-6 alone showed no significant effect on these pathological endpoints. However, CD3 (+) lymphocyte infiltration of lung tissue increased with MWCNT+ESAT-6 versus MWCNT alone. Findings suggest that concurrent exposure to microbial antigen and MWCNT exacerbates chronic pulmonary disease. PMID:27019768

Mechanical Stimulation by Postnasal Drip Evokes Cough

PubMed Central

Iwata, Toshiyuki; Ito, Isao; Niimi, Akio; Ikegami, Koji; Marumo, Satoshi; Tanabe, Naoya; Nakaji, Hitoshi; Kanemitsu, Yoshihiro; Matsumoto, Hisako; Kamei, Junzo; Setou, Mitsutoshi; Mishima, Michiaki

2015-01-01

Cough affects all individuals at different times, and its economic burden is substantial. Despite these widespread adverse effects, cough research relies on animal models, which hampers our understanding of the fundamental cause of cough. Postnasal drip is speculated to be one of the most frequent causes of chronic cough; however, this is a matter of debate. Here we show that mechanical stimuli by postnasal drip cause chronic cough. We distinguished human cough from sneezes and expiration reflexes by airflow patterns. Cough and sneeze exhibited one-peak and two-peak patterns, respectively, in expiratory airflow, which were also confirmed by animal models of cough and sneeze. Transgenic mice with ciliary dyskinesia coughed substantially and showed postnasal drip in the pharynx; furthermore, their cough was completely inhibited by nasal airway blockade of postnasal drip. We successfully reproduced cough observed in these mice by injecting artificial postnasal drip in wild-type mice. These results demonstrated that mechanical stimulation by postnasal drip evoked cough. The findings of our study can therefore be used to develop new antitussive drugs that prevent the root cause of cough. PMID:26581078

MyD88 signaling inhibits protective immunity to the gastrointestinal helminth parasite Heligmosomoides polygyrus.

PubMed

Reynolds, Lisa A; Harcus, Yvonne; Smith, Katherine A; Webb, Lauren M; Hewitson, James P; Ross, Ewan A; Brown, Sheila; Uematsu, Satoshi; Akira, Shizuo; Gray, David; Gray, Mohini; MacDonald, Andrew S; Cunningham, Adam F; Maizels, Rick M

2014-09-15

Helminth parasites remain one of the most common causes of infections worldwide, yet little is still known about the immune signaling pathways that control their expulsion. C57BL/6 mice are chronically susceptible to infection with the gastrointestinal helminth parasite Heligmosomoides polygyrus. In this article, we report that C57BL/6 mice lacking the adapter protein MyD88, which mediates signaling by TLRs and IL-1 family members, showed enhanced immunity to H. polygyrus infection. Alongside increased parasite expulsion, MyD88-deficient mice showed heightened IL-4 and IL-17A production from mesenteric lymph node CD4(+) cells. In addition, MyD88(-/-) mice developed substantial numbers of intestinal granulomas around the site of infection, which were not seen in MyD88-sufficient C57BL/6 mice, nor when signaling through the adapter protein TRIF (TIR domain-containing adapter-inducing IFN-β adapter protein) was also ablated. Mice deficient solely in TLR2, TLR4, TLR5, or TLR9 did not show enhanced parasite expulsion, suggesting that these TLRs signal redundantly to maintain H. polygyrus susceptibility in wild-type mice. To further investigate signaling pathways that are MyD88 dependent, we infected IL-1R1(-/-) mice with H. polygyrus. This genotype displayed heightened granuloma numbers compared with wild-type mice, but without increased parasite expulsion. Thus, the IL-1R-MyD88 pathway is implicated in inhibiting granuloma formation; however, protective immunity in MyD88-deficient mice appears to be granuloma independent. Like IL-1R1(-/-) and MyD88(-/-) mice, animals lacking signaling through the type 1 IFN receptor (i.e., IFNAR1(-/-)) also developed intestinal granulomas. Hence, IL-1R1, MyD88, and type 1 IFN receptor signaling may provide pathways to impede granuloma formation in vivo, but additional MyD88-mediated signals are associated with inhibition of protective immunity in susceptible C57BL/6 mice. Copyright © 2014 The Authors.

Environmental factors regulate Paneth cell phenotype and host susceptibility to intestinal inflammation in Irgm1-deficient mice.

PubMed

Rogala, Allison R; Schoenborn, Alexi A; Fee, Brian E; Cantillana, Viviana A; Joyce, Maria J; Gharaibeh, Raad Z; Roy, Sayanty; Fodor, Anthony A; Sartor, R Balfour; Taylor, Gregory A; Gulati, Ajay S

2018-02-07

Crohn's disease (CD) represents a chronic inflammatory disorder of the intestinal tract. Several susceptibility genes have been linked to CD, though their precise role in the pathogenesis of this disorder remains unclear. Immunity-related GTPase M ( IRGM ) is an established risk allele in CD. We have shown previously that conventionally raised (CV) mice lacking the IRGM ortholog, Irgm1 exhibit abnormal Paneth cells (PCs) and increased susceptibility to intestinal injury. In the present study, we sought to utilize this model system to determine if environmental conditions impact these phenotypes, as is thought to be the case in human CD. To accomplish this, wild-type and Irgm1 -/- mice were rederived into specific pathogen-free (SPF) and germ-free (GF) conditions. We next assessed how these differential housing environments influenced intestinal injury patterns, and epithelial cell morphology and function in wild-type and Irgm1 -/- mice. Remarkably, in contrast to CV mice, SPF Irgm1 -/- mice showed only a slight increase in susceptibility to dextran sodium sulfate-induced inflammation. SPF Irgm1 -/- mice also displayed minimal abnormalities in PC number and morphology, and in antimicrobial peptide expression. Goblet cell numbers and epithelial proliferation were also unaffected by Irgm1 in SPF conditions. No microbial differences were observed between wild-type and Irgm1 -/- mice, but gut bacterial communities differed profoundly between CV and SPF mice. Specifically, Helicobacter sequences were significantly increased in CV mice; however, inoculating SPF Irgm1 -/- mice with Helicobacter hepaticus was not sufficient to transmit a pro-inflammatory phenotype. In summary, our findings suggest the impact of Irgm1-deficiency on susceptibility to intestinal inflammation and epithelial function is critically dependent on environmental influences. This work establishes the importance of Irgm1 -/- mice as a model to elucidate host-environment interactions that regulate mucosal homeostasis and intestinal inflammatory responses. Defining such interactions will be essential for developing novel preventative and therapeutic strategies for human CD. © 2018. Published by The Company of Biologists Ltd.

Monocytes/Macrophages Control Resolution of Transient Inflammatory Pain

PubMed Central

Willemen, Hanneke L. D. M.; Eijkelkamp, Niels; Carbajal, Anibal Garza; Wang, Huijing; Mack, Matthias; Zijlstra, Jitske; Heijnen, Cobi J.; Kavelaars, Annemieke

2014-01-01

Insights into mechanisms governing resolution of inflammatory pain are of great importance for many chronic pain–associated diseases. Here we investigate the role of macrophages/monocytes and the anti-inflammatory cytokine interleukin-10 (IL-10) in the resolution of transient inflammatory pain. Depletion of mice from peripheral monocytes/macrophages delayed resolution of intraplantar IL-1β- and carrageenan-induced inflammatory hyperalgesia from 1 to 3 days to >1 week. Intrathecal administration of a neutralizing IL-10 antibody also markedly delayed resolution of IL-1β- and carrageenan-induced inflammatory hyperalgesia. Recently, we showed that IL-1β- and carrageenan-induced hyperalgesia is significantly prolonged in LysM-GRK2+/− mice, which have reduced levels of G-protein-coupled receptor kinase 2 (GRK2) in LysM+ myeloid cells. Here we show that adoptive transfer of wild-type, but not of GRK2+/−, bone marrow-derived monocytes normalizes the resolution of IL-1β-induced hyperalgesia in LysM-GRK2+/− mice. Adoptive transfer of IL-10−/− bone marrow-derived monocytes failed to normalize the duration of IL-1β-induced hyperalgesia in LysM-GRK2+/− mice. Mechanistically, we show that GRK2+/− macrophages produce less IL-10 in vitro. In addition, intrathecal IL-10 administration attenuated IL-1β-induced hyperalgesia in LysM-GRK2+/− mice, whereas it had no effect in wild-type mice. Our data uncover a key role for monocytes/macrophages in promoting resolution of inflammatory hyperalgesia via a mechanism dependent on IL-10 signaling in dorsal root ganglia. Perspective We show that IL-10-producing monocytes/macrophages promote resolution of transient inflammatory hyperalgesia. Additionally, we show that reduced monocyte/macrophage GRK2 impairs resolution of hyperalgesia and reduces IL-10 production. We propose that low GRK2 expression and/or impaired IL-10 production by monocytes/macrophages represent peripheral biomarkers for the risk of developing chronic pain after inflammation. PMID:24793056

Role of the nicotinic receptor β4 subunit in the antidepressant activity of novel N,6-dimethyltricyclo[5.2.1.0²,⁶]decan-2-amine enantiomers.

PubMed

Targowska-Duda, Katarzyna M; Jozwiak, Krzysztof; Arias, Hugo R

2013-10-11

The role of the nicotinic receptor β4 subunit in the antidepressant activity of N,6-dimethyltricyclo[5.2.1.0(2,6)]decan-2-amine enantiomers was investigated using wild-type (β4+/+) and knockout (β4-/-) mice. Mice were injected (i.p.) with saline (control) or with either enantiomer (1.0mg/kg base drug) daily for the first two weeks. Forced swim tests (FST) were performed on Day 1 to determine the acute effect of each enantiomer, and on Day 7 and 14, to determine the chronic activity. To examine the remnant effects after drug treatment, a withdrawal period of two more weeks was continued with FSTs performed on Day 21 and 28. Our results indicate that: (1) the acute antidepressant effect elicited by the (S,S)-enantiomer is observed in β4+/+ mice from both sexes, whereas the effect elicited by the (R,R)-enantiomer is only observed in male β4+/+ mice. There is no antidepressant effect for both novel compounds on male and female β4-/- mice, (2) the chronic antidepressant effect elicited by both enantiomers is observed in β4+/+, but not in β4-/-, mice from both sexes, and (3) the residual antidepressant effect mediated by each enantiomer after withdrawal was observed only in female β4+/+ mice. Our results clearly indicate that β4-containing AChRs are targets for the antidepressant activity of these compounds, and that this activity is gender-dependent. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Docosahexaenoic Acid Attenuated Experimental Chronic Colitis in Interleukin 10-Deficient Mice by Enhancing Autophagy Through Inhibition of the mTOR Pathway.

PubMed

Zhao, Jie; Dong, Jian-Ning; Wang, Hong-Gang; Zhao, Mingli; Sun, Jing; Zhu, Wei-Ming; Zuo, Lu-Gen; Gong, Jian-Feng; Li, Yi; Gu, Li-Li; Li, Ning; Li, Jie-Shou

2017-07-01

In the battle against Crohn's disease, autophagy stimulation is a promising therapeutic option-one both new and newly rediscovered. In experimental models, docosahexaenoic acid (DHA)-a long-chain polyunsaturated fatty acid-has been demonstrated to be useful in the treatment of inflammatory bowel disease through inhibition of the nuclear factor-κB pathway. However, the impact of DHA on autophagy in the colon remains unclear. Mice were divided into 3 groups: wild type (placebo), the interleukin 10 knockout group (IL-10 -/- , placebo), and the DHA group (IL-10 -/- , DHA). DHA was administered to IL-10 -/- mice by gavage at a dosage of 35.5 mg/kg/d for 2 weeks. The severity of colitis, expression of proinflammatory cytokines, expression/distribution of LC3B, and mTOR signaling pathway were evaluated in the proximal colon tissues collected from all mice at the end of the experiment. DHA administration ameliorated experimental colitis in the IL-10 -/- mice, as demonstrated by decreased proinflammatory cytokines (TNF-α and IFN-γ), reduced infiltration of inflammatory cells, and lowered histologic scores of the proximal colon mucosa. Moreover, in the DHA-treated mice, enhanced autophagy was observed to be associated with (1) increased expression and restoration of the distribution integrity of LC3B in the colon and (2) inhibition of the mTOR signaling pathway. This study showed that DHA therapy could attenuate experimental chronic colitis in IL-10 -/- mice by triggering autophagy via inhibition of the mTOR pathway.

Absence of stearoyl-CoA desaturase-1 does not promote DSS-induced acute colitis.

PubMed

Macdonald, Marcia L E; Bissada, Nagat; Vallance, Bruce A; Hayden, Michael R

2009-12-01

Absence of stearoyl-CoA desaturase-1 (SCD1) in mice leads to chronic inflammation of the skin and increased susceptibility to atherosclerosis, while also increasing plasma inflammatory markers. A recent report suggested that SCD1 deficiency also increases disease severity in a mouse model of inflammatory bowel disease, induced by dextran sulfate sodium (DSS). However, SCD1-deficient mice are known to consume increased amounts of water, which would also be expected to increase the intake of DSS-treated water. The aim of this study was to determine the effect of SCD1 deficiency on DSS-induced acute colitis with DSS dosing adjusted to account for genotype differences in fluid consumption. Wild-type controls were treated with 3.5% DSS for 5 days to induce moderately severe colitis, while the concentration of DSS given to SCD1-deficient mice was lowered to 2.5% to control for increased fluid consumption. Colonic inflammation was assessed by clinical and histological scoring. Although SCD1-deficient mice consumed a total intake of DSS that was greater than that of wild-type controls, colonic inflammation, colon length and fecal blood were not altered by SCD1-deficiency in DSS-induced colitis, while diarrhea and total weight loss were modestly improved. Despite SCD1 deficiency leading to chronic inflammation of the skin and increased susceptibility to atherosclerosis, it does not accelerate inflammation in the DSS-induced model of acute colitis when DSS intake is controlled. These observations suggest that SCD1 deficiency does not play a significant role in colonic inflammation in this model.

Constitutive TL1A expression under colitogenic conditions modulates the severity and location of gut mucosal inflammation and induces fibrostenosis.

PubMed

Barrett, Robert; Zhang, Xiaolan; Koon, Hon Wai; Vu, Michelle; Chang, Jyh-Yau; Yeager, Nicole; Nguyen, Mary Ann; Michelsen, Kathrin S; Berel, Dror; Pothoulakis, Charalabos; Targan, Stephan R; Shih, David Q

2012-02-01

Intestinal fibrostenosis is a hallmark of severe Crohn's disease and can lead to multiple surgeries. Patients with certain TNFSF15 variants overexpress TL1A. The aim of this study was to determine the effect of TL1A overexpression on intestinal inflammation and the development of fibrostenosis. We assessed the in vivo consequences of constitutive TL1A expression on gut mucosal inflammation and fibrostenosis using two murine models of chronic colitis. In the dextran sodium sulfate (DSS) and adoptive T-cell transfer models, there was proximal migration of colonic inflammation, worsened patchy intestinal inflammation, and long gross intestinal strictures in Tl1a transgenic compared to wild-type littermates. In the DSS model, myeloid- and T-cell-expressing Tl1a transgenic mice had increased T-cell activation markers and interleukin-17 expression compared to wild-type mice. In the T-cell transfer model, Rag1(-/-) mice receiving Tl1a transgenic T cells had increased interferon-γ expression but reduced T-helper 17 cells and IL-17 production. Narrowed ureters with hydronephrosis were found only in the Tl1a transgenic mice in all chronic colitis models. In human translational studies, Crohn's disease patients with higher peripheral TL1A expression also exhibited intestinal fibrostenosis and worsened ileocecal inflammation with relative sparing of rectosigmoid inflammation. These data show that TL1A is an important cytokine that not only modulates the location and severity of mucosal inflammation, but also induces fibrostenosis. Copyright © 2012 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.

A pivotal role of BEX1 in liver progenitor cell expansion in mice.

PubMed

Gu, Yuting; Wei, Weiting; Cheng, Yiji; Wan, Bing; Ding, Xinyuan; Wang, Hui; Zhang, Yanyun; Jin, Min

2018-06-15

The activation and expansion of bipotent liver progenitor cells (LPCs) are indispensable for liver regeneration after severe or chronic liver injury. However, the underlying molecular mechanisms regulating LPCs and LPC-mediated liver regeneration remain elusive. Hepatic brain-expressed X-linked 1 (BEX1) expression was evaluated using microarray screening, real-time polymerase chain reaction, immunoblotting and immunofluorescence. LPC activation and liver injury were studied following a choline-deficient, ethionine-supplemented (CDE) diet in wild-type (WT) and Bex1 -/- mice. Proliferation, apoptosis, colony formation and hepatic differentiation were examined in LPCs from WT and Bex1 -/- mice. Peroxisome proliferator-activated receptor gamma was detected in Bex1-deficient LPCs and mouse livers, and was silenced to analyse the expansion of LPCs from WT and Bex1 -/- mice. Hepatic BEX1 expression was increased during CDE diet-induced liver injury and was highly elevated primarily in LPCs. Bex1 -/- mice fed a CDE diet displayed impaired LPC expansion and liver regeneration. Bex1 deficiency inhibited LPC proliferation and enhanced LPC apoptosis in vitro. Additionally, Bex1 deficiency inhibited the colony formation of LPCs but had no effect on their hepatic differentiation. Mechanistically, BEX1 inhibited peroxisome proliferator-activated receptor gamma to promote LPC expansion. Our findings indicate that BEX1 plays a pivotal role in LPC activation and expansion during liver regeneration, potentially providing novel targets for liver regeneration and chronic liver disease therapies.

Effects of Melittin Treatment in Cholangitis and Biliary Fibrosis in a Model of Xenobiotic-Induced Cholestasis in Mice.

PubMed

Kim, Kyung-Hyun; Sung, Hyun-Jung; Lee, Woo-Ram; An, Hyun-Jin; Kim, Jung-Yeon; Pak, Sok Cheon; Han, Sang-Mi; Park, Kwan-Kyu

2015-08-25

Cholangiopathy is a chronic immune-mediated disease of the liver, which is characterized by cholangitis, ductular reaction and biliary-type hepatic fibrosis. There is no proven medical therapy that changes the course of the disease. In previous studies, melittin was known for attenuation of hepatic injury, inflammation and hepatic fibrosis. This study investigated whether melittin provides inhibition on cholangitis and biliary fibrosis in vivo. Feeding 3,5-diethoxycarbonyl-1,4-dihydrocollidine (DDC) to mice is a well-established animal model to study cholangitis and biliary fibrosis. To investigate the effects of melittin on cholangiopathy, mice were fed with a 0.1% DDC-containing diet with or without melittin treatment for four weeks. Liver morphology, serum markers of liver injury, cholestasis markers for inflammation of liver, the degree of ductular reaction and the degree of liver fibrosis were compared between with or without melittin treatment DDC-fed mice. DDC feeding led to increased serum markers of hepatic injury, ductular reaction, induction of pro-inflammatory cytokines and biliary fibrosis. Interestingly, melittin treatment attenuated hepatic function markers, ductular reaction, the reactive phenotype of cholangiocytes and cholangitis and biliary fibrosis. Our data suggest that melittin treatment can be protective against chronic cholestatic disease in DDC-fed mice. Further studies on the anti-inflammatory capacity of melittin are warranted for targeted therapy in cholangiopathy.

Effects of Melittin Treatment in Cholangitis and Biliary Fibrosis in a Model of Xenobiotic-Induced Cholestasis in Mice

PubMed Central

Kim, Kyung-Hyun; Sung, Hyun-Jung; Lee, Woo-Ram; An, Hyun-Jin; Kim, Jung-Yeon; Pak, Sok Cheon; Han, Sang-Mi; Park, Kwan-Kyu

2015-01-01

Cholangiopathy is a chronic immune-mediated disease of the liver, which is characterized by cholangitis, ductular reaction and biliary-type hepatic fibrosis. There is no proven medical therapy that changes the course of the disease. In previous studies, melittin was known for attenuation of hepatic injury, inflammation and hepatic fibrosis. This study investigated whether melittin provides inhibition on cholangitis and biliary fibrosis in vivo. Feeding 3,5-diethoxycarbonyl-1,4-dihydrocollidine (DDC) to mice is a well-established animal model to study cholangitis and biliary fibrosis. To investigate the effects of melittin on cholangiopathy, mice were fed with a 0.1% DDC-containing diet with or without melittin treatment for four weeks. Liver morphology, serum markers of liver injury, cholestasis markers for inflammation of liver, the degree of ductular reaction and the degree of liver fibrosis were compared between with or without melittin treatment DDC-fed mice. DDC feeding led to increased serum markers of hepatic injury, ductular reaction, induction of pro-inflammatory cytokines and biliary fibrosis. Interestingly, melittin treatment attenuated hepatic function markers, ductular reaction, the reactive phenotype of cholangiocytes and cholangitis and biliary fibrosis. Our data suggest that melittin treatment can be protective against chronic cholestatic disease in DDC-fed mice. Further studies on the anti-inflammatory capacity of melittin are warranted for targeted therapy in cholangiopathy. PMID:26308055

The protective effect of 20(S)-protopanaxadiol (PPD) against chronic sleep deprivation (CSD)-induced memory impairments in mice.

PubMed

Lu, Cong; Lv, Jingwei; Dong, Liming; Jiang, Ning; Wang, Yan; Fan, Bei; Wang, Fengzhong; Liu, Xinmin

2018-03-01

Sleep deprivation (SD) is associated with oxidative stress that causes learning and memory impairment. 20(S)-Protopanaxadiol (PPD), one of the protopanaxadiol-type saponins, has antioxidant and neuroprotective effect. This study was designed to research the protective effect of PPD against cognitive deficits induced by chronic sleep deprivation (CSD) in mice. The CSD model was induced by subjecting the mice to our self-made Sleep Interruption Apparatus (SIA) continuously for 14 days. The memory enhancing effects of PPD were evaluated by behavioral tests and the related mechanism was further explored by observing the oxidative stress changes in the cortex and hippocampus of mice. The results revealed that PPD (20 and 40 μmol/kg, i.p.) administration significantly improved the cognitive performance of CSD model mice in object location recognition experiment, novel object recognition task and Morris water maze test. Furthermore, PPD effectively restored the levels/activities of antioxidant defense biomarkers in the cortex and hippocampus, including the superoxide dismutase (SOD) enzyme activity, catalase (CAT) enzyme activity, glutathione (GSH), and lipid peroxidation (LPO). In conclusion, PPD could attenuate cognitive deficits induced by CSD, and the neuroprotective effect of PPD might be mediated by alleviation of oxidative stress. It was assumed that PPD has the potential to be a neuroprotective substance for cognition dysfunction. Copyright © 2018 Elsevier Inc. All rights reserved.

A chronic treatment with fluoxetine decreases 5-HT(1A) receptors labeling in mice selected as a genetic model of helplessness.

PubMed

Naudon, Laurent; El Yacoubi, Malika; Vaugeois, Jean-Marie; Leroux-Nicollet, Isabelle; Costentin, Jean

2002-05-17

Two lines of mice were bred for their opposite helpless behavior in the tail suspension test, i.e., helpless (HL) mice and non helpless (NHL) mice. The 5-HT(1A) receptor labeling was quantified by means of autoradiography with (3)H-8-OH-DPAT on brain sections from mice of these two lines. We observed a significantly higher level of (3)H-8-OH-DPAT binding sites density in HL mice comparatively to NHL mice, in the medial prefrontal, cingulate, motor and sensorial cortices, in several regions of the limbic system, such as CA3 field of hippocampus, dentate gyrus, medial and baso-medial amygdala, and in dorsal and median raphe nuclei. A chronic 21-day treatment with the antidepressant fluoxetine (10 mg/kg, i.p. daily) attenuated significantly the spontaneous helplessness in HL mice but did not alter the behavior of NHL mice. In the brain of HL mice chronically injected with fluoxetine, the elevated (3)H-8-OH-DPAT binding sites density was no longer observed after treatment in several regions, among which the raphe nuclei. Conversely, the antidepressant treatment did not modify the (3)H-8-OH-DPAT binding sites density in NHL mice. The variation of 5-HT(1A) receptors binding density in the HL mice in response to a chronic fluoxetine treatment parallels the attenuation of the spontaneous helplessness observed in the tail suspension test, and may underlie this behavior.

Chronic cannabinoid receptor 2 activation reverses paclitaxel neuropathy without tolerance or cannabinoid receptor 1-dependent withdrawal.

PubMed

Deng, Liting; Guindon, Josée; Cornett, Benjamin L; Makriyannis, Alexandros; Mackie, Ken; Hohmann, Andrea G

2015-03-01

Mixed cannabinoid receptor 1 and 2 (CB1 and CB2) agonists such as Δ(9)-tetrahydrocannabinol (Δ(9)-THC) can produce tolerance, physical withdrawal, and unwanted CB1-mediated central nervous system side effects. Whether repeated systemic administration of a CB2-preferring agonist engages CB1 receptors or produces CB1-mediated side effects is unknown. We evaluated antiallodynic efficacy, possible tolerance, and cannabimimetic side effects of repeated dosing with a CB2-preferring agonist AM1710 in a model of chemotherapy-induced neuropathy produced by paclitaxel using CB1 knockout (CB1KO), CB2 knockout (CB2KO), and wild-type (WT) mice. Comparisons were made with the prototypic classic cannabinoid Δ(9)-THC. We also explored the site and possible mechanism of action of AM1710. Paclitaxel-induced mechanical and cold allodynia developed to an equivalent degree in CB1KO, CB2KO, and WT mice. Both AM1710 and Δ(9)-THC suppressed established paclitaxel-induced allodynia in WT mice. In contrast to Δ(9)-THC, chronic administration of AM1710 did not engage CB1 activity or produce antinociceptive tolerance, CB1-mediated cannabinoid withdrawal, hypothermia, or motor dysfunction. Antiallodynic efficacy of systemic administration of AM1710 was absent in CB2KO mice and WT mice receiving the CB2 antagonist AM630, administered either systemically or intrathecally. Intrathecal administration of AM1710 also attenuated paclitaxel-induced allodynia in WT mice, but not CB2KO mice, implicating a possible role for spinal CB2 receptors in AM1710 antiallodynic efficacy. Finally, both acute and chronic administration of AM1710 decreased messenger RNA levels of tumor necrosis factor-α and monocyte chemoattractant protein 1 in lumbar spinal cord of paclitaxel-treated WT mice. Our results highlight the potential of prolonged use of CB2 agonists for managing chemotherapy-induced allodynia with a favorable therapeutic ratio marked by sustained efficacy and absence of tolerance, physical withdrawal, or CB1-mediated side effects. Copyright © 2015 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.

Promoting PGC-1α-driven mitochondrial biogenesis is detrimental in pressure-overloaded mouse hearts

PubMed Central

Karamanlidis, Georgios; Garcia-Menendez, Lorena; Kolwicz, Stephen C.; Lee, Chi Fung

2014-01-01

Mitochondrial dysfunction in animal models of heart failure is associated with downregulation of the peroxisome proliferator-activated receptor-γ coactivator (PGC)-1α pathway. To test whether PGC-1α is an appropriate therapeutic target for increasing mitochondrial biogenesis and improving function in heart failure, we used a transgenic (TG) mouse model of moderate overexpression of PGC-1α (∼3-fold) in the heart. TG mice had small increases in citrate synthase activity and mitochondria size in the heart without alterations in myocardial energetics or cardiac function at baseline. In vivo dobutamine stress increased fractional shortening in wild-type mice, but this increase was attenuated in TG mice, whereas ex vivo isolated perfused TG hearts demonstrated normal functional and energetic response to high workload challenge. When subjected to pressure overload by transverse aortic constriction (TAC), TG mice displayed a significantly greater acute mortality for both male and female mice; however, long-term survival up to 8 wk was similar between the two groups. TG mice also showed a greater decrease in fractional shortening and a greater increase in left ventricular chamber dimension in response to TAC. Mitochondrial gene expression and citrate synthase activity were mildly increased in TG mice compared with wild-type mice, and this difference was also maintained after TAC. Our data suggest that a moderate level of PGC-1α overexpression in the heart compromises acute survival and does not improve cardiac function during chronic pressure overload in mice. PMID:25172896

Chronic nicotine differentially alters spontaneous recovery of contextual fear in male and female mice.

PubMed

Tumolo, Jessica M; Kutlu, Munir Gunes; Gould, Thomas J

2018-04-02

Post-traumatic stress disorder (PTSD) is a devastating disorder with symptoms such as flashbacks, hyperarousal, and avoidance of reminders of the traumatic event. Exposure therapy, which attempts to extinguish fear responses, is a commonly used treatment for PTSD but relapse following successful exposure therapy is a frequent problem. In rodents, spontaneous recovery (SR), where extinguished fear responses resurface following extinction treatment, is used as a model of fear relapse. Previous studies from our lab showed that chronic nicotine impaired fear extinction and acute nicotine enhanced SR of contextual fear in adult male mice. In addition, we showed that acute nicotine's effects were specific to SR as acute nicotine did not affect recall of contextual fear conditioning in the absence of extinction. However, effects of chronic nicotine administration on SR are not known. Therefore, in the present study, we investigated if chronic nicotine administration altered SR or recall of contextual fear in adult male and female C57BL/6J mice. Our results showed that chronic nicotine significantly enhanced SR in female mice and significantly decreased SR in males. Chronic nicotine had no effect on recall of contextual fear in males or females. Female sham mice also had significantly less baseline SR than male sham mice. Overall, these results demonstrate sex differences in SR of fear memories and that chronic nicotine modulates these effects on SR but nicotine does not alter recall of contextual fear. Copyright © 2018 Elsevier B.V. All rights reserved.

Neutrophils alleviate fibrosis in the CCl4-induced mouse chronic liver injury model.

PubMed

Saijou, Eiko; Enomoto, Yutaka; Matsuda, Michitaka; Yuet-Yin Kok, Cindy; Akira, Shizuo; Tanaka, Minoru; Miyajima, Atsushi

2018-06-01

Tribbles pseudokinase 1 ( Trib1 ) is a negative regulator of CCAAT/enhancer binding protein α (C/EBPα) and is known to induce granulopoiesis while suppressing monocyte differentiation. Loss of Trib1 was previously shown to increase the neutrophil population in the spleen but lead to M2-like macrophage reduction. Because M2 macrophages are anti-inflammatory and promote tissue repair by producing fibrogenic factors, we investigated liver fibrosis in Trib1 -deficient mice. Interestingly, loss of Trib1 suppressed fibrosis in the CCl 4 -induced chronic liver injury model. Trib1 knockout increased neutrophils but had a minimal effect on the macrophage population in the liver. Hepatic expressions of neutrophil matrix metalloproteinases ( Mmp ) 8 and Mmp9 were increased, but the production of fibrogenic factors, including transforming growth factor β1, was not affected by loss of Trib1 . These results suggest that neutrophils are responsible for the suppression of fibrosis in Trib1 -deficient liver. Consistently, transplantation of Trib1 -deficient bone marrow cells into wild-type mice alleviated CCl 4 -induced fibrosis. Furthermore, expression of chemokine (C-X-C motif) ligand 1 ( Cxcl1 ) by adeno-associated viral vector in the normal liver recruited neutrophils and suppressed CCl 4 -induced fibrosis; infusion of wild-type neutrophils in CCl 4 -treated mice also ameliorated fibrosis. Using recombinant adeno-associated virus-mediated expression of Mmp8 and Mmp9 alleviated liver fibrosis. Finally, neutrophil depletion by infusion of Ly6G antibody significantly enhanced CCl 4 -induced fibrosis. Conclusion : While neutrophils are well known to exacerbate acute liver injury, our results demonstrate a beneficial role of neutrophils in chronic liver injury by promoting fibrolysis. ( Hepatology Communications 2018;2:703-717).

Neutrophils alleviate fibrosis in the CCl4‐induced mouse chronic liver injury model

PubMed Central

Saijou, Eiko; Enomoto, Yutaka; Matsuda, Michitaka; Yuet‐Yin Kok, Cindy; Akira, Shizuo; Tanaka, Minoru

2018-01-01

Tribbles pseudokinase 1 (Trib1) is a negative regulator of CCAAT/enhancer binding protein α (C/EBPα) and is known to induce granulopoiesis while suppressing monocyte differentiation. Loss of Trib1 was previously shown to increase the neutrophil population in the spleen but lead to M2‐like macrophage reduction. Because M2 macrophages are anti‐inflammatory and promote tissue repair by producing fibrogenic factors, we investigated liver fibrosis in Trib1‐deficient mice. Interestingly, loss of Trib1 suppressed fibrosis in the CCl4‐induced chronic liver injury model. Trib1 knockout increased neutrophils but had a minimal effect on the macrophage population in the liver. Hepatic expressions of neutrophil matrix metalloproteinases (Mmp)8 and Mmp9 were increased, but the production of fibrogenic factors, including transforming growth factor β1, was not affected by loss of Trib1. These results suggest that neutrophils are responsible for the suppression of fibrosis in Trib1‐deficient liver. Consistently, transplantation of Trib1‐deficient bone marrow cells into wild‐type mice alleviated CCl4‐induced fibrosis. Furthermore, expression of chemokine (C‐X‐C motif) ligand 1 (Cxcl1) by adeno‐associated viral vector in the normal liver recruited neutrophils and suppressed CCl4‐induced fibrosis; infusion of wild‐type neutrophils in CCl4‐treated mice also ameliorated fibrosis. Using recombinant adeno‐associated virus‐mediated expression of Mmp8 and Mmp9 alleviated liver fibrosis. Finally, neutrophil depletion by infusion of Ly6G antibody significantly enhanced CCl4‐induced fibrosis. Conclusion: While neutrophils are well known to exacerbate acute liver injury, our results demonstrate a beneficial role of neutrophils in chronic liver injury by promoting fibrolysis. (Hepatology Communications 2018;2:703‐717) PMID:29881822

Leukocyte Bim deficiency does not impact atherogenesis in ldlr -/- mice, despite a pronounced induction of autoimmune inflammation.

PubMed

Temmerman, Lieve; Westra, Marijke M; Bot, Ilze; van Vlijmen, Bart J M; van Bree, Niek; Bot, Martine; Habets, Kim L L; Keulers, Tom G H; van der Vlag, Johan; Cotter, Thomas G; van Berkel, Theo J C; Biessen, Erik A L

2017-06-08

Proapoptotic Bcl-2 family member Bim is particularly relevant for deletion of autoreactive and activated T and B cells, implicating Bim in autoimmunity. As atherosclerosis is a chronic inflammatory process with features of autoimmune disease, we investigated the impact of hematopoietic Bim deficiency on plaque formation and parameters of plaque stability. Bim -/- or wild type bone marrow transplanted ldlr -/- mice were fed a Western type diet (WTD) for 5 or 10 weeks, after which they were immunophenotyped and atherosclerotic lesions were analyzed. Bim -/- transplanted mice displayed splenomegaly and overt lymphocytosis. CD4 + and CD8 + T cells were more activated (increased CD69 and CD71 expression, increased interferon gamma production). B cells were elevated by 147%, with a shift towards the pro-atherogenic IgG-producing B2 cell phenotype, resulting in a doubling of anti-oxLDL IgG1 antibody titers in serum of bim -/- mice. Bim -/- mice displayed massive intraplaque accumulation of Ig complexes and of lesional T cells, although this did not translate in changes in plaque size or stability features (apoptotic cell and macrophage content). The surprising lack in plaque phenotype despite the profound pro-atherogenic immune effects may be attributable to the sharp reduction of serum cholesterol levels in WTD fed bim -/- mice.

Dietary selenium protects adiponectin knockout mice against chronic inflammation induced colon cancer.

PubMed

Saxena, Arpit; Fayad, Raja; Kaur, Kamaljeet; Truman, Samantha; Greer, Julian; Carson, James A; Chanda, Anindya

2017-04-03

Selenium (Se) is an essential dietary micronutrient that has been examined for protection against different types of cancers including colon cancer. Despite an established inverse association between Se and chronic inflammation induced colon cancer (CICC), the mechanistic understanding of Se's protective effects requires additional in-vivo studies using preclinical animal models of CICC. Adiponectin (APN) is an adipocytokine that is protective against CICC as well. However, its role in the anti-mutagenic effects of the Se-diet remains unknown. To address this knowledge gap, here we examine the ability of dietary Se in reducing CICC in APN knockout mice (KO) and its wild-type C57BL/6. CICC was induced with the colon cancer agent 1,2 dimethyl hydrazine (DMH) along with dextran sodium sulfate (DSS). Se-enhanced diet increased selenoproteins, Gpx-1 and Gpx-2, in the colon tissues, thereby reducing oxidative stress. Se-mediated reduction of CICC was evident from the histopathological studies in both mouse models. In both mice, reduction in inflammation and tumorigenesis associated well with reduced p65 phosphorylation and elevated 53 phosphorylation. Finally, we show that in both models Se-administration promotes goblet cell differentiation with a concomitant increase in the levels of associated proteins, Muc-2 and Math-1. Our findings suggest that Se's protection against CICC involves both colonic epithelial protection and anti-tumor effects that are independent of APN.

Chronic phase advance alters circadian physiological rhythms and peripheral molecular clocks

PubMed Central

Wolff, Gretchen; Duncan, Marilyn J.

2013-01-01

Shifting the onset of light, acutely or chronically, can profoundly affect responses to infection, tumor progression, development of metabolic disease, and mortality in mammals. To date, the majority of phase-shifting studies have focused on acute exposure to a shift in the timing of the light cycle, whereas the consequences of chronic phase shifts alone on molecular rhythms in peripheral tissues such as skeletal muscle have not been studied. In this study, we tested the effect of chronic phase advance on the molecular clock mechanism in two phenotypically different skeletal muscles. The phase advance protocol (CPA) involved 6-h phase advances (earlier light onset) every 4 days for 8 wk. Analysis of the molecular clock, via bioluminescence recording, in the soleus and flexor digitorum brevis (FDB) muscles and lung demonstrated that CPA advanced the phase of the rhythm when studied immediately after CPA. However, if the mice were placed into free-running conditions (DD) for 2 wk after CPA, the molecular clock was not phase shifted in the two muscles but was still shifted in the lung. Wheel running behavior remained rhythmic in CPA mice; however, the endogenous period length of the free-running rhythm was significantly shorter than that of control mice. Core body temperature, cage activity, and heart rate remained rhythmic throughout the experiment, although the onset of the rhythms was significantly delayed with CPA. These results provide clues that lifestyles associated with chronic environmental desynchrony, such as shift work, can have disruptive effects on the molecular clock mechanism in peripheral tissues, including both types of skeletal muscle. Whether this can contribute, long term, to increased incidence of insulin resistance/metabolic disease requires further study. PMID:23703115

Angiotensin II receptor blocker telmisartan enhances running endurance of skeletal muscle through activation of the PPAR-δ/AMPK pathway.

PubMed

Feng, Xiaoli; Luo, Zhidan; Ma, Liqun; Ma, Shuangtao; Yang, Dachun; Zhao, Zhigang; Yan, Zhencheng; He, Hongbo; Cao, Tingbing; Liu, Daoyan; Zhu, Zhiming

2011-07-01

Clinical trials have shown that angiotensin II receptor blockers reduce the new onset of diabetes in hypertensives; however, the underlying mechanisms remain unknown. We investigated the effects of telmisartan on peroxisome proliferator activated receptor γ (PPAR-δ) and the adenosine monophosphate (AMP)-activated protein kinase (AMPK) pathway in cultured myotubes, as well as on the running endurance of wild-type and PPAR-δ-deficient mice. Administration of telmisartan up-regulated levels of PPAR-δ and phospho-AMPKα in cultured myotubes. However, PPAR-δ gene deficiency completely abolished the telmisartan effect on phospho-AMPKαin vitro. Chronic administration of telmisartan remarkably prevented weight gain, enhanced running endurance and post-exercise oxygen consumption, and increased slow-twitch skeletal muscle fibres in wild-type mice, but these effects were absent in PPAR-δ-deficient mice. The mechanism is involved in PPAR-δ-mediated stimulation of the AMPK pathway. Compared to the control mice, phospho-AMPKα level in skeletal muscle was up-regulated in mice treated with telmisartan. In contrast, phospho-AMPKα expression in skeletal muscle was unchanged in PPAR-δ-deficient mice treated with telmisartan. These findings highlight the ability of telmisartan to improve skeletal muscle function, and they implicate PPAR-δ as a potential therapeutic target for the prevention of type 2 diabetes. © 2011 The Authors Journal of Cellular and Molecular Medicine © 2011 Foundation for Cellular and Molecular Medicine/Blackwell Publishing Ltd.

Restoration of the type I IFN–IL-1 balance through targeted blockade of PTGER4 inhibits autoimmunity in NOD mice

PubMed Central

Rahman, M. Jubayer; Quiel, Juan A.; Liu, Yi; Bhargava, Vipul; Zhao, Yongge; Hotta-Iwamura, Chie; Lau-Kilby, Annie W.; Malloy, Allison M.W.; Thoner, Timothy W.; Tarbell, Kristin V.

2018-01-01

Type I IFN (IFN-I) dysregulation contributes to type 1 diabetes (T1D) development, and although increased IFN-I signals are pathogenic at the initiation of autoimmune diabetes, IFN-I dysregulation at later pathogenic stages more relevant for therapeutic intervention is not well understood. We discovered that 5 key antigen-presenting cell subsets from adult prediabetic NOD mice have reduced responsiveness to IFN-I that is dominated by a decrease in the tonic-sensitive subset of IFN-I response genes. Blockade of IFNAR1 in prediabetic NOD mice accelerated diabetes and increased Th1 responses. Therefore, IFN-I responses shift from pathogenic to protective as autoimmunity progresses, consistent with chronic IFN-I exposure. In contrast, IL-1–associated inflammatory pathways were elevated in prediabetic mice. These changes correlated with human T1D onset-associated gene expression. Prostaglandin E2 (PGE2) and prostaglandin receptor 4 (PTGER4), a receptor for PGE2 that mediates both inflammatory and regulatory eicosanoid signaling, were higher in NOD mice and drive innate immune dysregulation. Treating prediabetic NOD mice with a PTGER4 antagonist restored IFNAR signaling, decreased IL-1 signaling, and decreased infiltration of leukocytes into the islets. Therefore, innate cytokine alterations contribute to both T1D-associated inflammation and autoimmune pathogenesis. Modulating innate immune balance via signals such as PTGER4 may contribute to treatments for autoimmunity. PMID:29415894

Obesity-induced chronic inflammation is associated with the reduced efficacy of influenza vaccine.

PubMed

Park, Hye-Lim; Shim, Seung-Hyun; Lee, Eun-Young; Cho, Whajung; Park, Sooho; Jeon, Hyun-Jung; Ahn, Sun-Young; Kim, Hun; Nam, Jae-Hwan

2014-01-01

The relationship between obesity and vaccine efficacy is a serious issue. Previous studies have shown that vaccine efficacy is lower in the obese than in the non-obese. Here, we examined the influence of obesity on the efficacy of influenza vaccination using high fat diet (HFD) and regular fat diet (RFD) mice that were immunized with 2 types of influenza virus vaccines-cell culture-based vaccines and egg-based vaccines. HFD mice showed lower levels of neutralizing antibody titers as compared with RFD mice. Moreover, HFD mice showed high levels of MCP-1 in serum and adipocytes, and low level of influenza virus-specific effector memory CD8(+) T cells. After challenge with influenza virus, the lungs of HFD mice showed more severe inflammatory responses as compared with the lungs of RFD mice, even after vaccination. Taken together, our data suggested that the inflammatory condition in obesity may contribute to the suppressed efficacy of influenza vaccination.

GABAergic neurons in nucleus accumbens are correlated to resilience and vulnerability to chronic stress for major depression

PubMed Central

Cui, Shan; Wang, Jin-Hui

2017-01-01

Background Major depression, persistent low mood, is one of common psychiatric diseases. Chronic stressful life is believed to be a major risk factor that leads to dysfunctions of the limbic system. However, a large number of the individuals with experiencing chronic stress do not suffer from major depression, called as resilience. Endogenous mechanisms underlying neuronal invulnerability to chronic stress versus major depression are largely unknown. As GABAergic neurons are vulnerable to chronic stress and their impairments is associated with major depression, we have examined whether the invulnerability of GABAergic neurons in the limbic system is involved in resilience. Results GABAergic neurons in the nucleus accumbens from depression-like mice induced by chronic unpredictable mild stress appear the decreases in their GABA release, spiking capability and excitatory input reception, compared with those in resilience mice. The levels of decarboxylase and vesicular GABA transporters decrease in depression-like mice, but not resilience. Materials and Methods Mice were treated by chronic unpredictable mild stress for three weeks. Depression-like behaviors or resilience was confirmed by seeing whether their behaviors change significantly in sucrose preference, Y-maze and forced swimming tests. Mice from controls as well as depression and resilience in response to chronic unpredictable mild stress were studied in terms of GABAergic neuron activity in the nucleus accumbens by cell electrophysiology and protein chemistry. Conclusions The impairment of GABAergic neurons in the nucleus accumbens is associated with major depression. The invulnerability of GABAergic neurons to chronic stress may be one of cellular mechanisms for the resilience to chronic stress. PMID:28415589

Effects of female steroid hormones on A-type K+ currents in murine colon.

PubMed

Beckett, Elizabeth A H; McCloskey, Conor; O'Kane, Neil; Sanders, Kenton M; Koh, Sang Don

2006-06-01

Idiopathic constipation is higher in women of reproductive age than postmenopausal women or men, suggesting that female steroid hormones influence gastrointestinal motility. How female hormones affect motility is unclear. Colonic motility is regulated by ion channels in colonic myocytes. Voltage-dependent K(+) channels serve to set the excitability of colonic muscles. We investigated regulation of Kv 4.3 channel expression in response to acute or chronic changes in female hormones. Patch clamp experiments and quantitative PCR were used to compare outward currents and transcript expression in colonic myocytes from male, non-pregnant, pregnant and ovariectomized mice. Groups of ovariectomized mice received injections of oestrogen or progesterone to investigate the effects of hormone replacement. The capacitance of colonic myocytes from non-pregnant females was larger than in males. Net outward current density in male and ovariectomized mice was higher than in non-pregnant females and oestrogen-treated ovariectomized mice. Current densities in late pregnancy were lower than in female controls. Progesterone had no effect on outward currents. A-type currents were decreased in non-pregnant females compared with ovariectomized mice, and were further decreased by pregnancy or oestrogen replacement. Kv 4.3 transcripts did not differ significantly between groups; however, expression of the potassium channel interacting protein KChIP1 was elevated in ovariectomized mice compared with female controls and oestrogen-treated ovariectomized mice. Delayed rectifier currents were not affected by oestrogen. In the mouse colon, oestrogen suppresses A-type currents, which are important for regulating excitability. These observations suggest a possible link between female hormones and altered colonic motility associated with menses, pregnancy and menopause.

Comparison of multiple enzyme activatable near infrared fluorescent molecular probes for detection and quantification of inflammation in murine colitis models

PubMed Central

Ding, Shengli; Blue, Randal E.; Morgan, Douglas R.; Lund, Pauline K.

2015-01-01

Background Activatable near-infrared fluorescent (NIRF) probes have been used for ex vivo and in vivo detection of intestinal tumors in animal models. We hypothesized that NIRF probes activatable by cathepsins or MMPs will detect and quantify dextran sulphate sodium (DSS) induced acute colonic inflammation in wild type (WT) mice or chronic colitis in IL-10 null mice ex vivo or in vivo. Methods WT mice given DSS, water controls and IL-10 null mice with chronic colitis were administered probes by retro-orbital injection. FMT2500 LX system imaged fresh and fixed intestine ex vivo and mice in vivo. Inflammation detected by probes was verified by histology and colitis scoring. NIRF signal intensity was quantified using 2D region of interest (ROI) ex vivo or 3D ROI-analysis in vivo. Results Ex vivo, seven probes tested yielded significant higher NIRF signals in colon of DSS treated mice versus controls. A subset of probes was tested in IL-10 null mice and yielded strong ex vivo signals. Ex vivo fluorescence signal with 680 series probes was preserved after formalin fixation. In DSS and IL-10 null models, ex vivo NIRF signal strongly and significantly correlated with colitis scores. In vivo, ProSense680, CatK680FAST and MMPsense680 yielded significantly higher NIRF signals in DSS treated mice than controls but background was high in controls. Conclusion Both cathepsin or MMP-activated NIRF-probes can detect and quantify colonic inflammation ex vivo. ProSense680 yielded the strongest signals in DSS colitis ex vivo and in vivo, but background remains a problem for in vivo quantification of colitis. PMID:24374874

Amitriptyline is efficacious in ameliorating muscle inflammation and depressive symptoms in the mdx mouse model of Duchenne muscular dystrophy.

PubMed

Manning, Jennifer; Kulbida, Rebecca; Rai, Prerana; Jensen, Lindsay; Bouma, Judith; Singh, Sanjay P; O'Malley, Dervla; Yilmazer-Hanke, Deniz

2014-10-01

Mutations in the structural protein dystrophin underlie muscular dystrophies characterized by progressive deterioration of muscle function. Dystrophin-deficient mdx mice are considered a model for Duchenne muscular dystrophy (DMD). Individuals with DMD are also susceptible to mood disorders, such as depression and anxiety. Therefore, the study objectives were to investigate the effects of the tricyclic antidepressant amitriptyline on mood, learning, central cytokine expression and skeletal muscle inflammation in mdx mice. Amitriptyline-induced effects (10 mg kg(-1) daily s.c. injections, 25 days) on the behaviour of mdx mice were investigated using the open field arena and tail suspension tests. The effects of chronic amitriptyline treatment on inflammatory markers were studied in the muscle and plasma of mdx mice, and mood-associated monoamine and cytokine concentrations were measured in the amygdala, hippocampus, prefrontal cortex, striatum, hypothalamus and midbrain. The mdx mice exhibited increased levels of anxiety and depressive-like behaviour compared with wild-type mice. Amitriptyline treatment had anxiolytic and antidepressant effects in mdx mice associated with elevations in serotonin levels in the amygdala and hippocampus. Inflammation in mdx skeletal muscle tissue was also reduced following amitriptyline treatment as indicated by decreased immune cell infiltration of muscle and lower levels of the pro-inflammatory cytokines tumour necrosis factor-α and interleukin-6 in the forelimb flexors. Interleukin-6 mRNA expression was remarkably reduced in the amygdala of mdx mice by chronic amitriptyline treatment. Positive effects of amitriptyline on mood, in addition to its anti-inflammatory effects in skeletal muscle, may make it an attractive therapeutic option for individuals with DMD. © 2014 The Authors. Experimental Physiology © 2014 The Physiological Society.

Prolonged Injury and Altered Lung Function after Ozone Inhalation in Mice with Chronic Lung Inflammation

PubMed Central

Groves, Angela M.; Gow, Andrew J.; Massa, Christopher B.; Laskin, Jeffrey D.

2012-01-01

Surfactant protein–D (Sftpd) is a pulmonary collectin important in down-regulating macrophage inflammatory responses. In these experiments, we analyzed the effects of chronic macrophage inflammation attributable to loss of Sftpd on the persistence of ozone-induced injury, macrophage activation, and altered functioning in the lung. Wild-type (Sftpd+/+) and Sftpd−/− mice (aged 8 wk) were exposed to air or ozone (0.8 parts per million, 3 h). Bronchoalveolar lavage (BAL) fluid and tissue were collected 72 hours later. In Sftpd−/− mice, but not Sftpd+/+ mice, increased BAL protein and nitrogen oxides were observed after ozone inhalation, indicating prolonged lung injury and oxidative stress. Increased numbers of macrophages were also present in BAL fluid and in histologic sections from Sftpd−/− mice. These cells were enlarged and foamy, suggesting that they were activated. This conclusion was supported by findings of increased BAL chemotactic activity, and increased expression of inducible nitric oxide synthase in lung macrophages. In both Sftpd+/+ and Sftpd−/− mice, inhalation of ozone was associated with functional alterations in the lung. Although these alterations were limited to central airway mechanics in Sftpd+/+ mice, both central airway and parenchymal mechanics were modified by ozone exposure in Sftpd−/− mice. The most notable changes were evident in resistance and elastance spectra and baseline lung function, and in lung responsiveness to changes in positive end-expiratory pressure. These data demonstrate that a loss of Sftpd is associated with prolonged lung injury, oxidative stress, and macrophage accumulation and activation in response to ozone, and with more extensive functional changes consistent with the loss of parenchymal integrity. PMID:22878412

Rapid development of colitis in NSAID-treated IL-10-deficient mice.

PubMed

Berg, Daniel J; Zhang, Juan; Weinstock, Joel V; Ismail, Hanan F; Earle, Keith A; Alila, Hector; Pamukcu, Rifat; Moore, Steven; Lynch, Richard G

2002-11-01

Interleukin (IL)-10 is an anti-inflammatory and immune regulatory cytokine. IL-10-deficient mice (IL-10(-/-)) develop chronic inflammatory bowel disease (IBD), indicating that endogenous IL-10 is a central regulator of the mucosal immune response. Prostaglandins are lipid mediators that may be important mediators of intestinal inflammation. In this study we assessed the role of prostaglandins in the regulation of mucosal inflammation in the IL-10(-/-) mouse model of IBD. Prostaglandin (PG) synthesis was inhibited with nonselective or cyclooxygenase (COX)-isoform selective inhibitors. Severity of inflammation was assessed histologically. Cytokine production was assessed by ribonuclease protection analysis and enzyme-linked immunosorbent assay. PGE(2) levels were assessed by enzyme immunoassay. COX-1 and COX-2 expression was assessed by Western blot analysis. Nonsteroidal anti-inflammatory drug (NSAID) treatment of wild-type mice had minimal effect on the colon. In contrast, NSAID treatment of 4-week-old IL-10(-/-) mice resulted in rapid development of colitis characterized by infiltration of the lamina propria with macrophages and interferon gamma-producing CD4(+) T cells. Colitis persisted after withdrawal of the NSAID. NSAID treatment decreased colonic PGE(2) levels by 75%. Treatment of IL-10(-/-) mice with sulindac sulfone (which does not inhibit PG production) did not induce colitis whereas the NSAID sulindac induced severe colitis. COX-1- or COX-2-selective inhibitors used alone did not induce IBD in IL-10(-/-) mice. However, the combination of COX-1- and COX-2-selective inhibitors did induce colitis. NSAID treatment of IL-10(-/-) mice results in the rapid development of severe, chronic IBD. Endogenous PGs are important inhibitors of the development of intestinal inflammation in IL-10(-/-) mice.

Renal Dysfunction Induced by Kidney-Specific Gene Deletion of Hsd11b2 as a Primary Cause of Salt-Dependent Hypertension.

PubMed

Ueda, Kohei; Nishimoto, Mitsuhiro; Hirohama, Daigoro; Ayuzawa, Nobuhiro; Kawarazaki, Wakako; Watanabe, Atsushi; Shimosawa, Tatsuo; Loffing, Johannes; Zhang, Ming-Zhi; Marumo, Takeshi; Fujita, Toshiro

2017-07-01

Genome-wide analysis of renal sodium-transporting system has identified specific variations of Mendelian hypertensive disorders, including HSD11B2 gene variants in apparent mineralocorticoid excess. However, these genetic variations in extrarenal tissue can be involved in developing hypertension, as demonstrated in former studies using global and brain-specific Hsd11b2 knockout rodents. To re-examine the importance of renal dysfunction on developing hypertension, we generated kidney-specific Hsd11b2 knockout mice. The knockout mice exhibited systemic hypertension, which was abolished by reducing salt intake, suggesting its salt-dependency. In addition, we detected an increase in renal membrane expressions of cleaved epithelial sodium channel-α and T53-phosphorylated Na + -Cl - cotransporter in the knockout mice. Acute intraperitoneal administration of amiloride-induced natriuresis and increased urinary sodium/potassium ratio more in the knockout mice compared with those in the wild-type control mice. Chronic administration of amiloride and high-KCl diet significantly decreased mean blood pressure in the knockout mice, which was accompanied with the correction of hypokalemia and the resultant decrease in Na + -Cl - cotransporter phosphorylation. Accordingly, a Na + -Cl - cotransporter blocker hydrochlorothiazide significantly decreased mean blood pressure in the knockout mice. Chronic administration of mineralocorticoid receptor antagonist spironolactone significantly decreased mean blood pressure of the knockout mice along with downregulation of cleaved epithelial sodium channel-α and phosphorylated Na + -Cl - cotransporter expression in the knockout kidney. Our data suggest that kidney-specific deficiency of 11β-HSD2 leads to salt-dependent hypertension, which is attributed to mineralocorticoid receptor-epithelial sodium channel-Na + -Cl - cotransporter activation in the kidney, and provides evidence that renal dysfunction is essential for developing the phenotype of apparent mineralocorticoid excess. © 2017 American Heart Association, Inc.

Deficiency in plasmacytoid dendritic cells and type I interferon signalling prevents diet-induced obesity and insulin resistance in mice.

PubMed

Hannibal, Tine D; Schmidt-Christensen, Anja; Nilsson, Julia; Fransén-Pettersson, Nina; Hansen, Lisbeth; Holmberg, Dan

2017-10-01

Obesity is associated with glucose intolerance and insulin resistance and is closely linked to the increasing prevalence of type 2 diabetes. In mouse models of diet-induced obesity (DIO) and type 2 diabetes, an increased fat intake results in adipose tissue expansion and the secretion of proinflammatory cytokines. The innate immune system not only plays a crucial role in obesity-associated chronic low-grade inflammation but it is also proposed to play a role in modulating energy metabolism. However, little is known about how the modulation of metabolism by the immune system may promote increased adiposity in the early stages of increased dietary intake. Here we aimed to define the role of type I IFNs in DIO and insulin resistance. Mice lacking the receptor for IFN-α (IFNAR -/- ) and deficient in plasmacytoid dendritic cells (pDCs) (B6.E2-2 fl/fl .Itgax-cre) were fed a diet with a high fat content or normal chow. The mice were analysed in vivo and in vitro using cellular, biochemical and molecular approaches. We found that the development of obesity was inhibited by an inability to respond to type I IFNs. Furthermore, the development of obesity and insulin resistance in this model was associated with pDC recruitment to the fatty tissues and liver of obese mice (a 4.3-fold and 2.7-fold increase, respectively). Finally, we demonstrated that the depletion of pDCs protects mice from DIO and from developing obesity-associated metabolic complications. Our results provide genetic evidence that pDCs, via type I IFNs, regulate energy metabolism and promote the development of obesity.

A Chronic Obstructive Pulmonary Disease Susceptibility Gene, FAM13A, Regulates Protein Stability of β-Catenin.

PubMed

Jiang, Zhiqiang; Lao, Taotao; Qiu, Weiliang; Polverino, Francesca; Gupta, Kushagra; Guo, Feng; Mancini, John D; Naing, Zun Zar Chi; Cho, Michael H; Castaldi, Peter J; Sun, Yang; Yu, Jane; Laucho-Contreras, Maria E; Kobzik, Lester; Raby, Benjamin A; Choi, Augustine M K; Perrella, Mark A; Owen, Caroline A; Silverman, Edwin K; Zhou, Xiaobo

2016-07-15

A genetic locus within the FAM13A gene has been consistently associated with chronic obstructive pulmonary disease (COPD) in genome-wide association studies. However, the mechanisms by which FAM13A contributes to COPD susceptibility are unknown. To determine the biologic function of FAM13A in human COPD and murine COPD models and discover the molecular mechanism by which FAM13A influences COPD susceptibility. Fam13a null mice (Fam13a(-/-)) were generated and exposed to cigarette smoke. The lung inflammatory response and airspace size were assessed in Fam13a(-/-) and Fam13a(+/+) littermate control mice. Cellular localization of FAM13A protein and mRNA levels of FAM13A in COPD lungs were assessed using immunofluorescence, Western blotting, and reverse transcriptase-polymerase chain reaction, respectively. Immunoprecipitation followed by mass spectrometry identified cellular proteins that interact with FAM13A to reveal insights on FAM13A's function. In murine and human lungs, FAM13A is expressed in airway and alveolar type II epithelial cells and macrophages. Fam13a null mice (Fam13a(-/-)) were resistant to chronic cigarette smoke-induced emphysema compared with Fam13a(+/+) mice. In vitro, FAM13A interacts with protein phosphatase 2A and recruits protein phosphatase 2A with glycogen synthase kinase 3β and β-catenin, inducing β-catenin degradation. Fam13a(-/-) mice were also resistant to elastase-induced emphysema, and this resistance was reversed by coadministration of a β-catenin inhibitor, suggesting that FAM13A could increase the susceptibility of mice to emphysema development by inhibiting β-catenin signaling. Moreover, human COPD lungs had decreased protein levels of β-catenin and increased protein levels of FAM13A. We show that FAM13A may influence COPD susceptibility by promoting β-catenin degradation.

CXC chemokine ligand 4 (Cxcl4) is a platelet-derived mediator of experimental liver fibrosis.

PubMed

Zaldivar, Mirko Moreno; Pauels, Katrin; von Hundelshausen, Philipp; Berres, Marie-Luise; Schmitz, Petra; Bornemann, Jörg; Kowalska, M Anna; Gassler, Nikolaus; Streetz, Konrad L; Weiskirchen, Ralf; Trautwein, Christian; Weber, Christian; Wasmuth, Hermann E

2010-04-01

Liver fibrosis is a major cause of morbidity and mortality worldwide. Platelets are involved in liver damage, but the underlying molecular mechanisms remain elusive. Here, we investigate the platelet-derived chemokine (C-X-C motif) ligand 4 (CXCL4) as a molecular mediator of fibrotic liver damage. Serum concentrations and intrahepatic messenger RNA of CXCL4 were measured in patients with chronic liver diseases and mice after toxic liver injury. Platelet aggregation in early fibrosis was determined by electron microscopy in patients and by immunohistochemistry in mice. Cxcl4(-/-) and wild-type mice were subjected to two models of chronic liver injury (CCl(4) and thioacetamide). The fibrotic phenotype was analyzed by histological, biochemical, and molecular analyses. Intrahepatic infiltration of immune cells was investigated by fluorescence-activated cell sorting, and stellate cells were stimulated with recombinant Cxcl4 in vitro. The results showed that patients with advanced hepatitis C virus-induced fibrosis or nonalcoholic steatohepatitis had increased serum levels and intrahepatic CXCL4 messenger RNA concentrations. Platelets were found directly adjacent to collagen fibrils. The CCl(4) and thioacetamide treatment led to an increase of hepatic Cxcl4 levels, platelet activation, and aggregation in early fibrosis in mice. Accordingly, genetic deletion of Cxcl4 in mice significantly reduced histological and biochemical liver damage in vivo, which was accompanied by changes in the expression of fibrosis-related genes (Timp-1 [tissue inhibitor of matrix metalloproteinase 1], Mmp9 [matrix metalloproteinase 9], Tgf-beta [transforming growth factor beta], IL10 [interleukin 10]). Functionally, Cxcl4(-/-) mice showed a strongly decreased infiltration of neutrophils (Ly6G) and CD8(+) T cells into the liver. In vitro, recombinant murine Cxcl4 stimulated the proliferation, chemotaxis, and chemokine expression of hepatic stellate cells. The results underscore an important role of platelets in chronic liver damage and imply a new target for antifibrotic therapies.

Histologic and biochemical alterations predict pulmonary mechanical dysfunction in aging mice with chronic lung inflammation

PubMed Central

Laskin, Debra L.; Gow, Andrew J.

2017-01-01

Both aging and chronic inflammation produce complex structural and biochemical alterations to the lung known to impact work of breathing. Mice deficient in surfactant protein D (Sftpd) develop progressive age-related lung pathology characterized by tissue destruction/remodeling, accumulation of foamy macrophages and alteration in surfactant composition. This study proposes to relate changes in tissue structure seen in normal aging and in chronic inflammation to altered lung mechanics using a computational model. Alterations in lung function in aging and Sftpd -/- mice have been inferred from fitting simple mechanical models to respiratory impedance data (Zrs), however interpretation has been confounded by the simultaneous presence of multiple coexisting pathophysiologic processes. In contrast to the inverse modeling approach, this study uses simulation from experimental measurements to recapitulate how aging and inflammation alter Zrs. Histologic and mechanical measurements were made in C57BL6/J mice and congenic Sftpd-/- mice at 8, 27 and 80 weeks of age (n = 8/group). An anatomic computational model based on published airway morphometry was developed and Zrs was simulated between 0.5 and 20 Hz. End expiratory pressure dependent changes in airway caliber and recruitment were estimated from mechanical measurements. Tissue elements were simulated using the constant phase model of viscoelasticity. Baseline elastance distribution was estimated in 8-week-old wild type mice, and stochastically varied for each condition based on experimentally measured alteration in elastic fiber composition, alveolar geometry and surfactant composition. Weighing reduction in model error against increasing model complexity allowed for identification of essential features underlying mechanical pathology and their contribution to Zrs. Using a maximum likelihood approach, alteration in lung recruitment and diminished elastic fiber density were shown predictive of mechanical alteration at airway opening, to a greater extent than overt acinar wall destruction. Model-predicted deficits in PEEP-dependent lung recruitment correlate with altered lung lining fluid composition independent of age or genotype. PMID:28837561

Histologic and biochemical alterations predict pulmonary mechanical dysfunction in aging mice with chronic lung inflammation.

PubMed

Massa, Christopher B; Groves, Angela M; Jaggernauth, Smita U; Laskin, Debra L; Gow, Andrew J

2017-08-01

Both aging and chronic inflammation produce complex structural and biochemical alterations to the lung known to impact work of breathing. Mice deficient in surfactant protein D (Sftpd) develop progressive age-related lung pathology characterized by tissue destruction/remodeling, accumulation of foamy macrophages and alteration in surfactant composition. This study proposes to relate changes in tissue structure seen in normal aging and in chronic inflammation to altered lung mechanics using a computational model. Alterations in lung function in aging and Sftpd -/- mice have been inferred from fitting simple mechanical models to respiratory impedance data (Zrs), however interpretation has been confounded by the simultaneous presence of multiple coexisting pathophysiologic processes. In contrast to the inverse modeling approach, this study uses simulation from experimental measurements to recapitulate how aging and inflammation alter Zrs. Histologic and mechanical measurements were made in C57BL6/J mice and congenic Sftpd-/- mice at 8, 27 and 80 weeks of age (n = 8/group). An anatomic computational model based on published airway morphometry was developed and Zrs was simulated between 0.5 and 20 Hz. End expiratory pressure dependent changes in airway caliber and recruitment were estimated from mechanical measurements. Tissue elements were simulated using the constant phase model of viscoelasticity. Baseline elastance distribution was estimated in 8-week-old wild type mice, and stochastically varied for each condition based on experimentally measured alteration in elastic fiber composition, alveolar geometry and surfactant composition. Weighing reduction in model error against increasing model complexity allowed for identification of essential features underlying mechanical pathology and their contribution to Zrs. Using a maximum likelihood approach, alteration in lung recruitment and diminished elastic fiber density were shown predictive of mechanical alteration at airway opening, to a greater extent than overt acinar wall destruction. Model-predicted deficits in PEEP-dependent lung recruitment correlate with altered lung lining fluid composition independent of age or genotype.

A BCR-ABL Kinase Activity-Independent Signaling Pathway in Chronic Myelogenous Leukemia

DTIC Science & Technology

2008-02-01

myeloproliferative disease in mice receiving P210 bcr/abl-transduced bone marrow. Blood. 1998;92:3780-3792. 17. Zhang X, Ren R. Bcr-Abl efficiently induces a... myeloproliferative disease and production of excess interleukin-3 and granulocyte-macrophage colony-stimulating factor in mice: a novel model for chronic...Xu L, et al. Efficient and rapid induction of a chronic myelogenous leukemia-like myeloproliferative disease in mice receiving P210 bcr/abl-transduced

Behaviour of a genetic mouse model of depression in the learned helplessness paradigm.

PubMed

Bougarel, Laure; Guitton, Jérôme; Zimmer, Luc; Vaugeois, Jean-Marie; El Yacoubi, Malika

2011-06-01

H/Rouen (displaying a helpless phenotype in the tail suspension test) mice exhibiting features of depressive disorders and NH/Rouen (displaying non-helpless phenotype) mice were previously created through behavioural screening and selective breeding. Learned helplessness (LH), in which footshock stress induces a coping deficit, models some aspects of depression in rodents, but so far, fewer LH studies have been performed in mice than in rats. To study H/Rouen and NH/Rouen in the LH paradigm. When CD1 mice were submitted to footshock with various training durations and shock intensities, the most suitable parameters to induce a behavioural deficit were 0.3 mA and four training sessions. A significantly longer latency to escape shocks was found in male H/Rouen mice compared to male NH/Rouen mice. On the other hand, once shocked, NH/Rouen mice showed more severe coping deficits than H/Rouen mice. In addition, a sub-chronic treatment with fluoxetine lacked efficacy in NH/Rouen mice, whereas it improved performances in H/Rouen mice. We also found that a shock reminder at day 8, subsequent to inescapable shocks, maintained helplessness for 20 days. Finally, female H/Rouen mice responded to chronic fluoxetine administration after 10 days of treatment, while a 20-day treatment was necessary to improve the behavioural deficit in H/Rouen male mice. H/Rouen and NH/Rouen lines displayed different despair-related behaviour in the LH paradigm. Fluoxetine had beneficial effects after sub-chronic or chronic but not acute treatment of H/Rouen mice, thus providing a pharmacological validation of the protocols.

The Macrophage Mannose Receptor Regulate Mannan-Induced Psoriasis, Psoriatic Arthritis, and Rheumatoid Arthritis-Like Disease Models

PubMed Central

Hagert, Cecilia; Sareila, Outi; Kelkka, Tiina; Jalkanen, Sirpa; Holmdahl, Rikard

2018-01-01

The injection of mannan into mice can result in the development of psoriasis (Ps) and psoriatic arthritis (PsA), whereas co-injection with antibodies toward collagen type II leads to a chronic rheumatoid-like arthritis. The critical event in all these diseases is mannan-mediated activation of macrophages, causing more severe disease if the macrophages are deficient in neutrophil cytosolic factor 1 (Ncf1), i.e., lack the capacity to make a reactive oxygen species (ROS) burst. In this study, we investigated the role of one of the receptors binding mannan; the macrophage mannose receptor (MR, CD206). MR is a C-type lectin present on myeloid cells and lymphatics. We found that mice deficient in MR expression had more severe mannan-induced Ps, PsA as well as rheumatoid-like arthritis. Interestingly, the MR-mediated protection was partly lost in Ncf1 mutated mice and was associated with an type 2 macrophage expansion. In conclusion, these results show that MR protects against a pathogenic inflammatory macrophage response induced by mannan and is associated with induction of ROS. PMID:29467756

Loss of Matrix Metalloproteinase-2 Amplifies Murine Toxin-Induced Liver Fibrosis by Upregulating Collagen I Expression

PubMed Central

Radbill, Brian D.; Gupta, Ritu; Ramirez, Maria Celeste M.; DiFeo, Analisa; Martignetti, John A.; Alvarez, Carlos E.; Friedman, Scott L.; Narla, Goutham; Vrabie, Raluca; Bowles, Robert; Saiman, Yedidya

2010-01-01

Background and Aims Matrix metalloproteinase-2 (MMP-2), a type IV collagenase secreted by activated hepatic stellate cells (HSCs), is upregulated in chronic liver disease and is considered a profibrotic mediator due to its proliferative effect on cultured HSCs and ability to degrade normal liver matrix. Although associative studies and cell culture findings suggest that MMP-2 promotes hepatic fibrogenesis, no in vivo model has definitively established a pathologic role for MMP-2 in the development and progression of liver fibrosis. We therefore examined the impact of MMP-2 deficiency on liver fibrosis development during chronic CCl4 liver injury and explored the effect of MMP-2 deficiency and overexpression on collagen I expression. Methods Following chronic CCl4 administration, liver fibrosis was analyzed using Sirius Red staining with quantitative morphometry and real-time polymerase chain reaction (PCR) in MMP-2−/− mice and age-matched MMP-2+/+ controls. These studies were complemented by analyses of cultured human stellate cells. Results MMP-2−/− mice demonstrated an almost twofold increase in fibrosis which was not secondary to significant differences in hepatocellular injury, HSC activation or type I collagenase activity; however, type I collagen messenger RNA (mRNA) expression was increased threefold in the MMP-2−/− group by real-time PCR. Furthermore, targeted reduction of MMP-2 in cultured HSCs using RNA interference significantly increased collagen I mRNA and protein, while overexpression of MMP-2 resulted in decreased collagen I mRNA. Conclusions These findings suggest that increased MMP-2 during the progression of liver fibrosis may be an important mechanism for inhibiting type I collagen synthesis by activated HSCs, thereby providing a protective rather than pathologic role. PMID:20563750

Early life environmental and pharmacological stressors result in persistent dysregulations of the serotonergic system

PubMed Central

Wong, Peiyan; Sze, Ying; Gray, Laura Jane; Chang, Cecilia Chin Roei; Cai, Shiwei; Zhang, Xiaodong

2015-01-01

Dysregulations in the brain serotonergic system and exposure to environmental stressors have been implicated in the development of major depressive disorder. Here, we investigate the interactions between the stress and serotonergic systems by characterizing the behavioral and biochemical effects of chronic stress applied during early-life or adulthood in wild type (WT) mice and mice with deficient tryptophan hydroxylase 2 (TPH2) function. We showed that chronic mild stress applied in adulthood did not affect the behaviors and serotonin levels of WT and TPH2 knock-in (KI) mice. Whereas, maternal separation (MS) stress increased anxiety- and depressive-like behaviors of WT mice, with no detectable behavioral changes in TPH2 KI mice. Biochemically, we found that MS WT mice had reduced brain serotonin levels, which was attributed to increased expression of monoamine oxidase A (MAO A). The increased MAO A expression was detected in MS WT mice at 4 weeks old and adulthood. No change in TPH2 expression was detected. To determine whether a pharmacological stressor, dexamethasone (Dex), will result in similar biochemical results obtained from MS, we used an in vitro system, SH-SY5Y cells, and found that Dex treatment resulted in increased MAO A expression levels. We then treated WT mice with Dex for 5 days, either during postnatal days 7–11 or adulthood. Both groups of Dex treated WT mice had reduced basal corticosterone and glucocorticoid receptors expression levels. However, only Dex treatment during PND7–11 resulted in reduced serotonin levels and increased MAO A expression. Just as with MS WT mice, TPH2 expression in PND7–11 Dex-treated WT mice was unaffected. Taken together, our findings suggest that both environmental and pharmacological stressors affect the expression of MAO A, and not TPH2, when applied during the critical postnatal period. This leads to long-lasting perturbations in the serotonergic system, and results in anxiety- and depressive-like behaviors. PMID:25964750

Impairment of contextual fear extinction by chronic nicotine and withdrawal from chronic nicotine is associated with hippocampal nAChR upregulation

PubMed Central

Kutlu, Munir Gunes; Oliver, Chicora; Huang, Peng; Liu-Chen, Lee-Yuan; Gould, Thomas J.

2017-01-01

Chronic nicotine and withdrawal from chronic nicotine have been shown to be major modulators of fear learning behavior. Moreover, recent studies from our laboratory have shown that acute nicotine impaired fear extinction and safety learning in mice. However, the effects of chronic nicotine and withdrawal on fear extinction are unknown. Therefore, the current experiments were conducted to investigate the effects of chronic nicotine as well as withdrawal from chronic nicotine on contextual fear extinction in mice. C57BL6/J mice were given contextual fear conditioning training and retention testing during chronic nicotine administration. Mice then received contextual fear extinction either during chronic nicotine or during withdrawal from chronic nicotine. Our results showed that contextual fear extinction was impaired both during chronic nicotine administration and subsequent withdrawal. However, it was also observed that the effects of prior chronic nicotine disappeared after 72 h in withdrawal, a timeline that closely matches with the timing of the chronic nicotine-induced upregulation of hippocampal nicotinic acetylcholine receptor (nAChR) density. Additional experiments found that 4 days, but not 1 day, of continuous nicotine administration upregulated hippocampal nAChRs and impaired contextual fear extinction. These effects disappeared following 72 h withdrawal. Overall, these experiments provide a potential link between nicotine-induced upregulation of hippocampal nAChRs and fear extinction deficits observed in patients with anxiety disorders, which may lead to advancements in the pharmacological treatment methods for this disorder. PMID:27378334

Effect of Bifidobacterium breve B-3 on skin photoaging induced by chronic UV irradiation in mice.

PubMed

Satoh, T; Murata, M; Iwabuchi, N; Odamaki, T; Wakabayashi, H; Yamauchi, K; Abe, F; Xiao, J Z

2015-01-01

Probiotics have been shown to have a preventative effect on skin photoaging induced by short term UV irradiation, however, the underlying mechanisms and the effect of probiotics on skin photoaging induced by chronic UV irradiation remain unclear. In this study, we investigated the effect of Bifidobacterium breve B-3 on skin photoaging induced by chronic UV irradiation in hairless mice. Mice were irradiated with UVB three times weekly and orally administered B. breve B-3 (2×10(9) cfu/mouse /day) for 7 weeks. Nonirradiated mice and UVB-irradiated mice without probiotic treatment were used as controls. B. breve B-3 significantly suppressed the changes of transepidermal water loss, skin hydration, epidermal thickening and attenuated the damage to the tight junction structure and basement membrane induced by chronic UVB irradiation. Administration of B. breve B-3 tended to suppress the UV-induced interleukin-1β production in skin (P=0.09). These results suggest that B. breve B-3 could potentially be used to prevent photoaging induced by chronic UV irradiation.

Alcohol intake alters immune responses and promotes CNS viral persistence in mice.

PubMed

Loftis, Jennifer M; Taylor, Jonathan; Raué, Hans-Peter; Slifka, Mark K; Huang, Elaine

2016-10-01

Chronic hepatitis C virus (HCV) infection leads to progressive liver disease and is associated with a variety of extrahepatic effects, including central nervous system (CNS) damage and neuropsychiatric impairments. Alcohol abuse can exacerbate these adverse effects on brain and behavior, but the molecular mechanisms are not well understood. This study investigated the role of alcohol in regulating viral persistence and CNS immunopathology in mice infected with lymphocytic choriomeningitis virus (LCMV), a model for HCV infections in humans. Female and male BALB/c mice (n=94) were exposed to alcohol (ethanol; EtOH) and water (or water only) using a two-bottle choice paradigm, followed one week later by infection with either LCMV clone 13 (causes chronic infection similar to chronic HCV), LCMV Armstrong (causes acute infection), or vehicle. Mice were monitored for 60days post-infection and continued to receive 24-h access to EtOH and water. Animals infected with LCMV clone 13 drank more EtOH, as compared to those with an acute or no viral infection. Six weeks after infection with LCMV clone 13, mice with EtOH exposure evidenced higher serum viral titers, as compared to mice without EtOH exposure. EtOH intake was also associated with reductions in virus-specific CD8(+) T cell frequencies (particularly CD11a(hi) subsets) and evidence of persistent CNS viremia in chronically infected mice. These findings support the hypothesis that EtOH use and chronic viral infection can result in combined toxic effects accelerating CNS damage and neuropsychiatric dysfunction and suggest that examining the role of EtOH in regulating viral persistence and CNS immunopathology in mice infected with LCMV can lead to a more comprehensive understanding of comorbid alcohol use disorder and chronic viral infection. Published by Elsevier B.V.

Role of thin descending limb urea transport in renal urea handling and the urine concentrating mechanism

PubMed Central

Lei, Tianluo; Zhou, Lei; Layton, Anita T.; Zhou, Hong; Zhao, Xuejian; Bankir, Lise

2011-01-01

Urea transporters UT-A2 and UT-B are expressed in epithelia of thin descending limb of Henle's loop and in descending vasa recta, respectively. To study their role and possible interaction in the context of the urine concentration mechanism, a UT-A2 and UT-B double knockout (UT-A2/B knockout) mouse model was generated by targeted deletion of the UT-A2 promoter in embryonic stem cells with UT-B gene knockout. The UT-A2/B knockout mice lacked detectable UT-A2 and UT-B transcripts and proteins and showed normal survival and growth. Daily urine output was significantly higher in UT-A2/B knockout mice than that in wild-type mice and lower than that in UT-B knockout mice. Urine osmolality in UT-A2/B knockout mice was intermediate between that in UT-B knockout and wild-type mice. The changes in urine osmolality and flow rate, plasma and urine urea concentration, as well as non-urea solute concentration after an acute urea load or chronic changes in protein intake suggested that UT-A2 plays a role in the progressive accumulation of urea in the inner medulla. These results suggest that in wild-type mice UT-A2 facilitates urea absorption by urea efflux from the thin descending limb of short loops of Henle. Moreover, UT-A2 deletion in UT-B knockout mice partially remedies the urine concentrating defect caused by UT-B deletion, by reducing urea loss from the descending limbs to the peripheral circulation; instead, urea is returned to the inner medulla through the loops of Henle and the collecting ducts. PMID:21849488

Role of thin descending limb urea transport in renal urea handling and the urine concentrating mechanism.

PubMed

Lei, Tianluo; Zhou, Lei; Layton, Anita T; Zhou, Hong; Zhao, Xuejian; Bankir, Lise; Yang, Baoxue

2011-12-01

Urea transporters UT-A2 and UT-B are expressed in epithelia of thin descending limb of Henle's loop and in descending vasa recta, respectively. To study their role and possible interaction in the context of the urine concentration mechanism, a UT-A2 and UT-B double knockout (UT-A2/B knockout) mouse model was generated by targeted deletion of the UT-A2 promoter in embryonic stem cells with UT-B gene knockout. The UT-A2/B knockout mice lacked detectable UT-A2 and UT-B transcripts and proteins and showed normal survival and growth. Daily urine output was significantly higher in UT-A2/B knockout mice than that in wild-type mice and lower than that in UT-B knockout mice. Urine osmolality in UT-A2/B knockout mice was intermediate between that in UT-B knockout and wild-type mice. The changes in urine osmolality and flow rate, plasma and urine urea concentration, as well as non-urea solute concentration after an acute urea load or chronic changes in protein intake suggested that UT-A2 plays a role in the progressive accumulation of urea in the inner medulla. These results suggest that in wild-type mice UT-A2 facilitates urea absorption by urea efflux from the thin descending limb of short loops of Henle. Moreover, UT-A2 deletion in UT-B knockout mice partially remedies the urine concentrating defect caused by UT-B deletion, by reducing urea loss from the descending limbs to the peripheral circulation; instead, urea is returned to the inner medulla through the loops of Henle and the collecting ducts.

Iron is associated with the development of hypoxia-induced pulmonary vascular remodeling in mice.

PubMed

Naito, Yoshiro; Hosokawa, Manami; Sawada, Hisashi; Oboshi, Makiko; Iwasaku, Toshihiro; Okuhara, Yoshitaka; Eguchi, Akiyo; Nishimura, Koichi; Soyama, Yuko; Hirotani, Shinichi; Mano, Toshiaki; Ishihara, Masaharu; Masuyama, Tohru

2016-12-01

Several recent observations provide the association of iron deficiency with pulmonary hypertension (PH) in human and animal studies. However, it remains completely unknown whether PH leads to iron deficiency or iron deficiency enhances the development of PH. In addition, it is obscure whether iron is associated with the development of pulmonary vascular remodeling in PH. In this study, we investigate the impacts of dietary iron restriction on the development of hypoxia-induced pulmonary vascular remodeling in mice. Eight- to ten-week-old male C57BL/6J mice were exposed to chronic hypoxia for 4 weeks. Mice exposed to hypoxia were randomly divided into two groups and were given a normal diet or an iron-restricted diet. Mice maintained in room air served as normoxic controls. Chronic hypoxia induced pulmonary vascular remodeling, while iron restriction led a modest attenuation of this change. In addition, chronic hypoxia exhibited increased RV systolic pressure, which was attenuated by iron restriction. Moreover, the increase in RV cardiomyocyte cross-sectional area and RV interstitial fibrosis was observed in mice exposed to chronic hypoxia. In contrast, iron restriction suppressed these changes. Consistent with these changes, RV weight to left ventricular + interventricular septum weight ratio was increased in mice exposed to chronic hypoxia, while this increment was inhibited by iron restriction. Taken together, these results suggest that iron is associated with the development of hypoxia-induced pulmonary vascular remodeling in mice.

Epac2a-null mice exhibit obesity-prone nature more susceptible to leptin resistance.

PubMed

Hwang, M; Go, Y; Park, J-H; Shin, S-K; Song, S E; Oh, B-C; Im, S-S; Hwang, I; Jeon, Y H; Lee, I-K; Seino, S; Song, D-K

2017-02-01

The exchange protein directly activated by cAMP (Epac), which is primarily involved in cAMP signaling, has been known to be essential for controlling body energy metabolism. Epac has two isoforms: Epac1 and Epac2. The function of Epac1 on obesity was unveiled using Epac1 knockout (KO) mice. However, the role of Epac2 in obesity remains unclear. To evaluate the role of Epac2 in obesity, we used Epac2a KO mice, which is dominantly expressed in neurons and endocrine tissues. Physiological factors related to obesity were analyzed: body weight, fat mass, food intake, plasma leptin and adiponectin levels, energy expenditure, glucose tolerance, and insulin and leptin resistance. To determine the mechanism of Epac2a, mice received exogenous leptin and then hypothalamic leptin signaling was analyzed. Epac2a KO mice appeared to have normal glucose tolerance and insulin sensitivity until 12 weeks of age, but an early onset increase of plasma leptin levels and decrease of plasma adiponectin levels compared with wild-type mice. Acute leptin injection revealed impaired hypothalamic leptin signaling in KO mice. Consistently, KO mice fed a high-fat diet (HFD) were significantly obese, presenting greater food intake and lower energy expenditure. HFD-fed KO mice were also characterized by greater impairment of hypothalamic leptin signaling and by weaker leptin-induced decrease in food consumption compared with HFD-fed wild-type mice. In wild-type mice, acute exogenous leptin injection or chronic HFD feeding tended to induce hypothalamic Epac2a expression. Considering that HFD is an inducer of hypothalamic leptin resistance and that Epac2a functions in pancreatic beta cells during demands of greater work load, hypothalamic Epac2a may have a role in facilitating leptin signaling, at least in response to higher metabolic demands. Thus, our data indicate that Epac2a is critical for preventing obesity and thus Epac2a activators may be used to manage obesity and obesity-mediated metabolic disorders.

Monosodium glutamate (MSG): a villain and promoter of liver inflammation and dysplasia.

PubMed

Nakanishi, Yuko; Tsuneyama, Koichi; Fujimoto, Makoto; Salunga, Thucydides L; Nomoto, Kazuhiro; An, Jun-Ling; Takano, Yasuo; Iizuka, Seiichi; Nagata, Mitsunobu; Suzuki, Wataru; Shimada, Tsutomu; Aburada, Masaki; Nakano, Masayuki; Selmi, Carlo; Gershwin, M Eric

2008-01-01

Chronic inflammation is a common theme in a variety of disease pathways, including autoimmune diseases. The pathways of chronic inflammation are well illustrated by nonalcoholic steatohepatitis (NASH), which is of a serious concern due to its increasing prevalence in the westernized world and its direct correlation with lifestyle factors, particularly diet. Importantly, NASH may ultimately lead to the development of hepatocellular carcinoma. We previously reported that injection of monosodium glutamate (MSG) in ICR mice leads to the development of significant inflammation, central obesity, and type 2 diabetes. To directly address the long-term consequences of MSG on inflammation, we have performed serial analysis of MSG-injected mice and focused in particular on liver pathology. By 6 and 12 months of age, all MSG-treated mice developed NAFLD and NASH-like histology, respectively. In particular, the murine steatohepatitis at 12 months was virtually undistinguishable from human NASH. Further, dysplastic nodular lesions were detected in some cases within the fibrotic liver parenchyma. We submit that MSG treatment of mice induces obesity and diabetes with steatosis and steatohepatitis resembling human NAFLD and NASH with pre-neoplastic lesions. These results take on considerable significance in light of the widespread usage of dietary MSG and we suggest that MSG should have its safety profile re-examined and be potentially withdrawn from the food chain.

Concentration- and age-dependent effects of chronic caffeine on contextual fear conditioning in C57BL/6J mice

PubMed Central

Poole, Rachel L.; Braak, David; Gould, Thomas J.

2015-01-01

Chronic caffeine exerts negligible effects on learning and memory in normal adults, but it is unknown whether this is also true for children and adolescents. The hippocampus, a brain region important for learning and memory, undergoes extensive structural and functional modifications during pre-adolescence and adolescence. As a result, chronic caffeine may have differential effects on hippocampus-dependent learning in pre-adolescents and adolescents compared with adults. Here, we characterized the effects of chronic caffeine and withdrawal from chronic caffeine on hippocampus-dependent (contextual) and hippocampus-independent (cued) fear conditioning in pre-adolescent, adolescent, and adult mice. The results indicate that chronic exposure to caffeine during pre-adolescence and adolescence enhances or impairs contextual conditioning depending on concentration, yet has no effect on cued conditioning. In contrast, withdrawal from chronic caffeine impairs contextual conditioning in pre-adolescent mice only. No changes in learning were seen for adult mice for either the chronic caffeine or withdrawal conditions. These findings support the hypothesis that chronic exposure to caffeine during pre-adolescence and adolescence can alter learning and memory and as changes were only seen in hippocampus-dependent learning, this suggests that the developing hippocampus may be sensitive to the effects of caffeine. PMID:25827925

Chronic restraint stress promotes learning and memory impairment due to enhanced neuronal endoplasmic reticulum stress in the frontal cortex and hippocampus in male mice.

PubMed

Huang, Rong-Rong; Hu, Wen; Yin, Yan-Yan; Wang, Yu-Chan; Li, Wei-Ping; Li, Wei-Zu

2015-02-01

Chronic stress has been implicated in many types of neurodegenerative diseases, such as Alzheimer's disease (AD). In our previous study, we demonstrated that chronic restraint stress (CRS) induced reactive oxygen species (ROS) overproduction and oxidative damage in the frontal cortex and hippocampus in mice. In the present study, we investigated the effects of CRS (over a period of 8 weeks) on learning and memory impairment and endoplasmic reticulum (ER) stress in the frontal cortex and hippocampus in male mice. The Morris water maze was used to investigate the effects of CRS on learning and memory impairment. Immunohistochemistry and immunoblot analysis were also used to determine the expression levels of protein kinase C α (PKCα), 78 kDa glucose-regulated protein (GRP78), C/EBP-homologous protein (CHOP) and mesencephalic astrocyte-derived neurotrophic factor (MANF). The results revealed that CRS significantly accelerated learning and memory impairment, and induced neuronal damage in the frontal cortex and hippocampus CA1 region. Moreover, CRS significantly increased the expression of PKCα, CHOP and MANF, and decreased that of GRP78 in the frontal cortex and hippocampus. Our data suggest that exposure to CRS (for 8 weeks) significantly accelerates learning and memory impairment, and the mechanisms involved may be related to ER stress in the frontal cortex and hippocampus.

Influenza A virus-dependent remodeling of pulmonary clock function in a mouse model of COPD

PubMed Central

Sundar, Isaac K.; Ahmad, Tanveer; Yao, Hongwei; Hwang, Jae-woong; Gerloff, Janice; Lawrence, B. Paige; Sellix, Michael T.; Rahman, Irfan

2015-01-01

Daily oscillations of pulmonary function depend on the rhythmic activity of the circadian timing system. Environmental tobacco/cigarette smoke (CS) disrupts circadian clock leading to enhanced inflammatory responses. Infection with influenza A virus (IAV) increases hospitalization rates and death in susceptible individuals, including patients with Chronic Obstructive Pulmonary Disease (COPD). We hypothesized that molecular clock disruption is enhanced by IAV infection, altering cellular and lung function, leading to severity in airway disease phenotypes. C57BL/6J mice exposed to chronic CS, BMAL1 knockout (KO) mice and wild-type littermates were infected with IAV. Following infection, we measured diurnal rhythms of clock gene expression in the lung, locomotor activity, pulmonary function, inflammatory, pro-fibrotic and emphysematous responses. Chronic CS exposure combined with IAV infection altered the timing of clock gene expression and reduced locomotor activity in parallel with increased lung inflammation, disrupted rhythms of pulmonary function, and emphysema. BMAL1 KO mice infected with IAV showed pronounced detriments in behavior and survival, and increased lung inflammatory and pro-fibrotic responses. This suggests that remodeling of lung clock function following IAV infection alters clock-dependent gene expression and normal rhythms of lung function, enhanced emphysematous and injurious responses. This may have implications for the pathobiology of respiratory virus-induced airway disease severity and exacerbations. PMID:25923474

Evidence of reactive astrocytes but not peripheral immune system activation in a mouse model of Fragile X Syndrome

PubMed Central

Yuskaitis, Christopher J.; Beurel, Eleonore; Jope, Richard S.

2010-01-01

Fragile X syndrome (FXS) is the most common form of inherited mental retardation and is one of the few known genetic causes of autism. FXS results from the loss of Fmr1 gene function, thus Fmr1 knockout mice provide a model to study impairments associated with FXS and autism and to test potential therapeutic interventions. The inhibitory serine-phosphorylation of glycogen synthase kinase-3 (GSK3) is lower in brain regions of Fmr1 knockout mice than wild-type mice and the GSK3 inhibitor lithium rescues several behavioral impairments in Fmr1 knockout mice. Therefore, we examined if the serine-phosphorylation of GSK3 in Fmr1 knockout mice also was altered outside the brain and if administration of lithium ameliorated the macroorchidism phenotype. Additionally, since GSK3 regulates numerous functions of the immune system and immune alterations have been associated with autism, we tested if immune function is altered in Fmr1 knockout mice. The inhibitory serine-phosphorylation of GSK3 was significantly lower in the testis and liver of Fmr1 knockout mice than wild-type mice, and chronic lithium treatment reduced macroorchidism in Fmr1 knockout mice. No alterations in peripheral immune function were identified in Fmr1 knockout mice. However, examination of glia, the immune cells of the brain, revealed reactive astrocytes in several brain regions of Fmr1 knockout mice and treatment with lithium reduced this in the striatum and cerebellum. These results provide further evidence of the involvement of dysregulated GSK3 in FXS, and demonstrate that lithium administration reduces macroorchidism and reactive astrocytes in Fmr1 knockout mice. PMID:20600866

Sex differences in complex regional pain syndrome type I (CRPS-I) in mice.

PubMed

Tang, Chaoliang; Li, Juan; Tai, Wai Lydia; Yao, Weifeng; Zhao, Bo; Hong, Junmou; Shi, Si; Wang, Song; Xia, Zhongyuan

2017-01-01

Sex differences have been increasingly highlighted in complex regional pain syndrome (CRPS) in clinical practice. In CRPS type I (CRPS-I), although inflammation and oxidative stress have been implicated in its pathogenesis, whether pain behavior and the underlying mechanism are sex-specific is unclear. In the present study, we sought to explore whether sex differences have an impact on inflammation, oxidative stress, and pain sensitivity in CRPS-I. Chronic post-ischemia pain (CPIP) was established in both male and female mice as an animal model of CRPS-I. Edema and mechanical allodynia of bilateral hind paws were assessed after reperfusion. Blood samples were analyzed for serum levels of oxidative stress markers and inflammatory cytokines. Both male and female mice developed edema. Male mice developed CPIP at day 3 after reperfusion; female mice developed CPIP at day 2 after reperfusion. Female mice displayed significantly earlier and higher mechanical allodynia in the ischemic hind paw, which was associated with higher serum levels of IL-2, TNF-α, isoprostanes, 8 OhdG, and malondialdehyde at day 2 after reperfusion. Moreover, female mice showed significantly lower SOD and IL-4 compared to male mice at day 2 after reperfusion. Our results indicate that sex differences in inflammatory and oxidative stress states may play a central role in the sex-specific nociceptive hypersensitivity in CRPS-I, and offer a new insight into pharmacology treatments to improve pain management with CRPS.

Surviving starvation: essential role of the ghrelin-growth hormone axis.

PubMed

Goldstein, J L; Zhao, T-j; Li, R L; Sherbet, D P; Liang, G; Brown, M S

2011-01-01

After brief starvation, vertebrates maintain blood glucose by releasing fatty acids from adipose tissue. The fatty acids provide energy for gluconeogenesis in liver and are taken up by muscle, sparing glucose. After prolonged starvation, fat stores are depleted, yet blood glucose can be maintained at levels sufficient to preserve life. Using a new mouse model, we demonstrate that survival after prolonged starvation requires ghrelin, an octanoylated peptide hormone that stimulates growth hormone (GH) secretion. We studied wild-type mice and mice lacking ghrelin as a result of knockout of GOAT, the enzyme that attaches octanoate to ghrelin. Mice were fed 40% of their normal intake for 7 d. Fat stores in both lines of mice became depleted after 4 d. On day 7, mice were fasted for 23 h. In wild-type mice, ghrelin and GH rose massively, and blood sugar was maintained at ~60 mg/dL. In Goat(-/-) mice, ghrelin was undetectable and GH failed to rise appropriately. Blood sugar declined to ~20 mg/dL, and the animals were moribund. Infusion of ghrelin or GH prevented hypoglycemia. Our results support the following sequence: (1) Starvation lowers blood glucose; (2) glucose-sensing neurons respond by activating sympathetic neurons; (3) norepinephrine, released in the stomach, stimulates ghrelin secretion; (4) ghrelin releases GH, which maintains blood glucose. Thus, ghrelin lies at the center of a hormonal response that permits mice to survive an acute fast superimposed on chronic starvation.

Distorted leukocyte migration, angiogenesis, wound repair and metastasis in Tspan8 and Tspan8/CD151 double knockout mice indicate complementary activities of Tspan8 and CD51.

PubMed

Zhao, Kun; Erb, Ulrike; Hackert, Thilo; Zöller, Margot; Yue, Shijing

2018-02-01

The tetraspanin Tspan8 supports via associated integrins and proteases tumor progression and angiogenesis. To shed light on its activities in non-transformed cells, we generated a Tspan8 knockout (ko) mouse, comparing leukocyte migration, angiogenesis, wound healing and tumor growth with wild type, CD151ko and Tspan8/CD151ko (dbko) mice. CD151ko mice were included as CD151 activities resemble that of Tspan8, and dbko mice to exclude mutual substitution. Tspan8ko and dbko mice show no pathological phenotype. However, delayed type hypersensitivity reactions are mitigated in Tspan8ko mice, angiogenesis is severely impaired in Tspan8ko, CD151ko and dbko mice, with Tspan8 mostly affecting lymphangiogenesis. Distinct contributions of CD151 and Tspan8 to skin wound healing rely on preferentially CD151 anchoring basal keratinocytes and Tspan8 promoting motility. Proliferation of wounded skin keratinocytes is not affected. Metastasis formation of a melanoma and a Tspan8-expressing pancreatic cancer line was impaired in Tspan8ko and dbko mice, pointing towards a contribution of host Tspan8 to tumor progression. In line with the importance of tetraspanins in exosome-mediated intercellular communication, defects became mitigated by Tspan8/CD151-competent serum exosomes, which offers a most promising therapeutic option for chronic wounds and arteriosclerosis. Copyright © 2017 Elsevier B.V. All rights reserved.

Early postnatal motor experience shapes the motor properties of C57BL/6J adult mice.

PubMed

Serradj, Nadjet; Picquet, Florence; Jamon, Marc

2013-11-01

This study aimed to evaluate the long-term consequences of early motor training on the muscle phenotype and motor output of middle-aged C57BL/6J mice. Neonatal mice were subjected to a variety of motor training procedures, for 3 weeks during the period of acquisition of locomotion. These procedures are widely used for motor training in adults; they include enriched environment, forced treadmill, chronic centrifugation, and hindlimb suspension. At 9 months, the mice reared in the enriched environment showed a slower type of fibre in slow muscles and a faster type in fast muscles, improved performance in motor tests, and a modified gait and body posture while walking. The proportion of fibres in the postural muscles of centrifuged mice did not change, but these mice showed improved resistance to fatigue. The suspended mice showed increased persistence of immature hybrid fibres in the tibialis, with a slower shift in the load-bearing soleus, without any behavioural changes. The forced treadmill was very stressful for the mice, but had limited effects on motor output, although a slower profile was observed in the tibialis. These results support the hypothesis that motor experience during a critical period of motor development shapes muscle phenotype and motor output. The different impacts of the various training procedures suggest that motor performance in adults can be optimized by appropriate training during a defined period of motor development. © 2013 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

Whey peptides prevent chronic ultraviolet B radiation-induced skin aging in melanin-possessing male hairless mice.

PubMed

Kimura, Yoshiyuki; Sumiyoshi, Maho; Kobayashi, Toshiya

2014-01-01

Whey proteins or peptides exhibit various actions, including an antioxidant action, an anticancer action, and a protective action against childhood asthma and atopic syndrome. The effects of orally administered whey peptides (WPs) on chronic ultraviolet B (UVB) radiation-induced cutaneous changes, including changes in cutaneous thickness, elasticity, wrinkle formation, etc., have not been examined. In this study, we studied the preventive effects of WPs on cutaneous aging induced by chronic UVB irradiation in melanin-possessing male hairless mice (HRM). UVB (36-180 mJ/cm(2)) was irradiated to the dorsal area for 17 wk in HRM, and the measurements of cutaneous thickness and elasticity in UVB irradiated mice were performed every week. WPs (200 and 400 mg/kg, twice daily) were administered orally for 17 wk. WPs inhibited the increase in cutaneous thickness, wrinkle formation, and melanin granules and the reduction in cutaneous elasticity associated with photoaging. Furthermore, it has been reported that UVB irradiation-induced skin aging is closely associated with the increase in expression of matrix metalloproteinase (MMP), vascular endothelial growth factor (VEGF), Ki-67-, and 8-hydroxy-2'-deoxyguanosine (8-OHdG)-positive cells. WPs also prevented increases in the expression of MMP-2 and pro-MMP-9, VEGF, and Ki-67- and 8-OHdG-positive cells induced by chronic UVB irradiation. It was found that WPs prevent type IV collagen degradation, angiogenesis, proliferation, and DNA damage caused by UVB irradiation. Overall, these results demonstrate the considerable benefit of WPs for protection against solar UV-irradiated skin aging as a supplemental nutrient.

Metformin suppresses cancer initiation and progression in genetic mouse models of pancreatic cancer.

PubMed

Chen, Ke; Qian, Weikun; Jiang, Zhengdong; Cheng, Liang; Li, Jie; Sun, Liankang; Zhou, Cancan; Gao, Luping; Lei, Meng; Yan, Bin; Cao, Junyu; Duan, Wanxing; Ma, Qingyong

2017-07-24

Pancreatic ductal adenocarcinoma (PDAC) is the fourth leading cause of cancer-associated mortality worldwide with an overall five-year survival rate less than 7%. Accumulating evidence has revealed the cancer preventive and therapeutic effects of metformin, one of the most widely prescribed medications for type 2 diabetes mellitus. However, its role in pancreatic cancer is not fully elucidated. Herein, we aimed to further study the preventive and therapeutic effects of metformin in genetically engineered mouse models of pancreatic cancer. LSL-Kras G12D/+ ; Pdx1-Cre (KC) mouse model was established to investigate the effect of metformin in pancreatic tumorigenesis suppression; LSL-Kras G12D/+ ; Trp53 fl/+ ; Pdx1-Cre (KPC) mouse model was used to evaluate the therapeutic efficiency of metformin in PDAC. Chronic pancreatitis was induced in KC mice by peritoneal injection of cerulein. Following metformin treatment, pancreatic acinar-to-ductal metaplasia (ADM) and mouse pancreatic intraepithelial neoplasia (mPanIN) were decreased in KC mice. Chronic pancreatitis induced a stroma-rich and duct-like structure and increased the formation of ADM and mPanIN lesions, in line with an increased cytokeratin 19 (CK19)-stained area. Metformin treatment diminished chronic pancreatitis-mediated ADM and mPanIN formation. In addition, it alleviated the percent area of Masson's trichrome staining, and decreased the number of Ki67-positive cells. In KPC mice, metformin inhibited tumor growth and the incidence of abdominal invasion. More importantly, it prolonged the overall survival. Metformin inhibited pancreatic cancer initiation, suppressed chronic pancreatitis-induced tumorigenesis, and showed promising therapeutic effect in PDAC.

Exposure to waterpipe smoke induces renal functional and oxidative biomarkers variations in mice.

PubMed

Rababa'h, Abeer M; Sultan, Bilal B; Alzoubi, Karem H; Khabour, Omar F; Ababneh, Mera A

2016-09-01

Waterpipe smoking (WPS) has been known for over 400 years. It has been spread widely especially between youth because of the addition of pleasant flavor and because it was misconsidered to be less harmful than cigarette. In this study, we investigated the effect of waterpipe smoking on renal oxidative and functional parameters and compared that at acute and chronic exposure time in mice. Mice were divided into three groups, namely acute, chronic and fresh air control. Acute group was exposed to waterpipe smoke for one hour daily for six days using whole-body exposure system, while chronic group was exposed to waterpipe smoke for one hour daily for 30 days using whole-body exposure system. Exposure to waterpipe smoke has shown significant changes on the mice kidney functional parameters such as creatinine and blood urea nitrogen. Both exposures (acute and chronic) has shown a significant reduction in superoxide dismutase (SOD) activity (p < 0.05), whereas the activity of other antioxidant enzymes (catalase and GPx) reduced only with chronic exposure to waterpipe smoke (p < 0.05). Additionally, the level of thiobarbituric acid reactive substances (TBARS) in mice kidney homogenates has shown a significant elevation following chronic exposure to waterpipe smoke (p < 0.05). In conclusion, chronic waterpipe smoke affects the kidney parameter and antioxidant markers, therefore affecting its functionality of detoxifying and removal of poisonous material from the body.

Stress-induced hyperlocomotion as a confounding factor in anxiety and depression models in mice.

PubMed

Strekalova, T; Spanagel, R; Dolgov, O; Bartsch, D

2005-05-01

Chronic stress is broadly used to model anxiety and depression. However, in chronic stress models, anxiety- and depression-like behaviors might be masked by unspecific effects of stress. We tested whether chronic stress in mice can induce unspecific changes in locomotion, and whether these changes interfere with the measurement of anxiety and forced-swimming behaviors. Also, we studied these latter behaviors in relation to the duration of stress, the lighting conditions during testing, and after the injection of diazepam. We employed a 4-week chronic stress paradigm, adopted from a model of stress-induced anhedonia and a 1-week subchronic stress, both consisting of rat exposure, restraint stress and tail suspension. Chronically stressed mice, tested under bright and moderate illumination, exhibited 'anxiolytic-like' behavior along with prolonged swimming and hyperactivity. These behaviors were not detectable under weak illumination or after the injection of diazepam (0.25 mg/kg). Instead, normal locomotion, increased anxiety and inhibited swimming were revealed under these conditions. Thus, chronic stress can induce hyperlocomotion in mice, which is triggered by acute stressors such as light, and interferes with the evaluation of anxiety and forced swimming. One week of stress did not change locomotion and forced swimming, and increased anxiety irrespective of illumination applied during testing. Our data can possibly explain previously reported contradictions in the behavioral testing of mice with chronic stress models of anxiety and depression.

Chronic traumatic stress impairs memory in mice: Potential roles of acetylcholine, neuroinflammation and corticotropin releasing factor expression in the hippocampus.

PubMed

Bhakta, Ami; Gavini, Kartheek; Yang, Euitaek; Lyman-Henley, Lani; Parameshwaran, Kodeeswaran

2017-09-29

Chronic stress in humans can result in multiple adverse psychiatric and neurobiological outcomes, including memory deficits. These adverse outcomes can be more severe if each episode of stress is very traumatic. When compared to acute or short term stress relatively little is known about the effects of chronic traumatic stress on memory and molecular changes in hippocampus, a brain area involved in memory processing. Here we studied the effects of chronic traumatic stress in mice by exposing them to adult Long Evan rats for 28 consecutive days and subsequently analyzing behavioral outcomes and the changes in the hippocampus. Results show that stressed mice developed memory deficits when assayed with radial arm maze tasks. However, chronic traumatic stress did not induce anxiety, locomotor hyperactivity or anhedonia. In the hippocampus of stressed mice interleukin-1β protein expression was increased along with decreased corticotropin releasing hormone (CRH) gene expression. Furthermore, there was a reduction in acetylcholine levels in the hippocampus of stressed mice. There were no changes in brain derived neurotrophic factor (BDNF) or nerve growth factor (NGF) levels in the hippocampus of stressed mice. Gene expression of immediate early genes (Zif268, Arc, C-Fos) as well as glucocorticoid and mineralocorticoid receptors were also not affected by chronic stress. These data demonstrate that chronic traumatic stress followed by a recovery period might lead to development of resilience resulting in the development of selected, most vulnerable behavioral alterations and molecular changes in the hippocampus. Copyright © 2017 Elsevier B.V. All rights reserved.

Use of a crossed high alcohol preferring (cHAP) mouse model with the NIAAA-model of chronic-binge ethanol intake to study liver injury.

PubMed

Thompson, Kyle J; Nazari, Shayan S; Jacobs, W Carl; Grahame, Nicholas J; McKillop, Iain H

2017-11-01

This study sought to compare mice bred to preferentially consume high amounts of alcohol (crossed-high alcohol preferring, cHAP) to c57BL/6 (C57) mice using a chronic-binge ethanol ingestion model to induce alcoholic liver disease (ALD). Male C57 and cHAP mice were randomized to a Lieber-DeCarli control (LDC) diet, Lieber-DeCarli 5% (v/v) ethanol (LDE) diet or free-choice between 10% (v/v) ethanol in drinking water (EtOH-DW) and DW. After 4 weeks mice were gavaged with either 9 g/kg maltose-dextrin (LDC+MD) or 5 g/kg EtOH (LDE+Binge, EtOH-DW+Binge). Nine hours later tissue and serum were collected and analyzed. cHAP mice on EtOH-DW consumed significantly more ethanol than cHAP or C57 mice maintained on LDE. However, cHAP and C57 mice on the LDE+Binge regiment had greater hepatosteatosis and overall degree of liver injury compared to EtOH-DW+Binge. Changes in pro-inflammatory gene expression was more pronounced in cHAP mice than C57 mice. Analysis of liver enzymes revealed a robust induction of CYP2E1 in C57 and cHAP mice maintained on EtOH-DW+Binge or LDE+Binge. However, while C57 mice exhibited higher basal hepatic glutathione than cHAP mice, these mice appeared more susceptible to oxidative stress following LDE+Binge than cHAP counterparts. Despite cHAP mice consuming more total ethanol prior to gavage when maintained on EtOH-DW, LDE followed by gavage created a more severe model of ALD in both C57 and cHAP mice. These data suggest factors other than total amount of alcohol consumed affect degree of ALD development in the chronic-binge model in cHAP mice. cHAP mice voluntarily consume high amounts of ethanol and exhibited hepatic injury when subject to chronic-binge ethanol feeding with the Lieber-DeCarli diet. However, hepatic injury was reduced in cHAP mice in a chronic-binge model following voluntary high ethanol consumption in drinking water. © The Author 2017. Medical Council on Alcohol and Oxford University Press. All rights reserved.

TRPV1 Blocking Alleviates Airway Inflammation and Remodeling in a Chronic Asthma Murine Model.

PubMed

Choi, Joon Young; Lee, Hwa Young; Hur, Jung; Kim, Kyung Hoon; Kang, Ji Young; Rhee, Chin Kook; Lee, Sook Young

2018-05-01

Asthma is a chronic inflammatory airway disease characterized by airway hyperresponsiveness (AHR), inflammation, and remodeling. There is emerging interest in the involvement of the transient receptor potential vanilloid 1 (TRPV1) channel in the pathophysiology of asthma. This study examined whether TRPV1 antagonism alleviates asthma features in a murine model of chronic asthma. BALB/c mice were sensitized to and challenged by ovalbumin to develop chronic asthma. Capsazepine (TRPV1 antagonist) or TRPV1 small interfering RNA (siRNA) was administered in the treatment group to evaluate the effect of TPV1 antagonism on AHR, airway inflammation, and remodeling. The mice displayed increased AHR, airway inflammation, and remodeling. Treatment with capsazepine or TRPV1 siRNA reduced AHR to methacholine and airway inflammation. Type 2 T helper (Th2) cytokines (interleukin [IL]-4, IL-5, and IL-13) were reduced and epithelial cell-derived cytokines (thymic stromal lymphopoietin [TSLP], IL-33, and IL-25), which regulate Th2 cytokine-associated inflammation, were also reduced. Airway remodeling characterized by goblet cell hyperplasia, increased α-smooth muscle action, and collagen deposition was also alleviated by both treatments. Treatment directed at TRPV1 significantly alleviated AHR, airway inflammation, and remodeling in a chronic asthma murine model. The TRPV1 receptor can be a potential drug target for chronic bronchial asthma. Copyright © 2018 The Korean Academy of Asthma, Allergy and Clinical Immunology · The Korean Academy of Pediatric Allergy and Respiratory Disease.

Genotoxic effects of high dose rate X-ray and low dose rate gamma radiation in ApcMin/+ mice.

PubMed

Graupner, Anne; Eide, Dag M; Brede, Dag A; Ellender, Michele; Lindbo Hansen, Elisabeth; Oughton, Deborah H; Bouffler, Simon D; Brunborg, Gunnar; Olsen, Ann Karin

2017-10-01

Risk estimates for radiation-induced cancer in humans are based on epidemiological data largely drawn from the Japanese atomic bomb survivor studies, which received an acute high dose rate (HDR) ionising radiation. Limited knowledge exists about the effects of chronic low dose rate (LDR) exposure, particularly with respect to the application of the dose and dose rate effectiveness factor. As part of a study to investigate the development of colon cancer following chronic LDR vs. acute HDR radiation, this study presents the results of genotoxic effects in blood of exposed mice. CBAB6 F1 Apc +/+ (wild type) and Apc Min/+ mice were chronically exposed to estimated whole body absorbed doses of 1.7 or 3.2 Gy 60 Co-γ-rays at a LDR (2.2 mGy h -1 ) or acutely exposed to 2.6 Gy HDR X-rays (1.3 Gy min -1 ). Genotoxic endpoints assessed in blood included chromosomal damage (flow cytometry based micronuclei (MN) assay), mutation analyses (Pig-a gene mutation assay), and levels of DNA lesions (Comet assay, single-strand breaks (ssb), alkali labile sites (als), oxidized DNA bases). Ionising radiation (ca. 3 Gy) induced genotoxic effects dependent on the dose rate. Chromosomal aberrations (MN assay) increased 3- and 10-fold after chronic LDR and acute HDR, respectively. Phenotypic mutation frequencies as well as DNA lesions (ssb/als) were modulated after acute HDR but not after chronic LDR. The Apc Min/+ genotype did not influence the outcome in any of the investigated endpoints. The results herein will add to the scant data available on genotoxic effects following chronic LDR of ionising radiation. Environ. Mol. Mutagen. 58:560-569, 2017. © 2017 The Authors Environmental and Molecular Mutagenesis published by Wiley Periodicals, Inc. on behalf of Environmental Mutagen Society. © 2017 The Authors Environmental and Molecular Mutagenesis published by Wiley Periodicals, Inc. on behalf of Environmental Mutagen Society.

Genotoxic effects of high dose rate X‐ray and low dose rate gamma radiation in ApcMin/+ mice

PubMed Central

Eide, Dag M.; Brede, Dag A.; Ellender, Michele; Lindbo Hansen, Elisabeth; Oughton, Deborah H.; Bouffler, Simon D.; Brunborg, Gunnar; Olsen, Ann Karin

2017-01-01

Risk estimates for radiation‐induced cancer in humans are based on epidemiological data largely drawn from the Japanese atomic bomb survivor studies, which received an acute high dose rate (HDR) ionising radiation. Limited knowledge exists about the effects of chronic low dose rate (LDR) exposure, particularly with respect to the application of the dose and dose rate effectiveness factor. As part of a study to investigate the development of colon cancer following chronic LDR vs. acute HDR radiation, this study presents the results of genotoxic effects in blood of exposed mice. CBAB6 F1 Apc+/+ (wild type) and ApcMin/+ mice were chronically exposed to estimated whole body absorbed doses of 1.7 or 3.2 Gy 60Co‐γ‐rays at a LDR (2.2 mGy h−1) or acutely exposed to 2.6 Gy HDR X‐rays (1.3 Gy min−1). Genotoxic endpoints assessed in blood included chromosomal damage (flow cytometry based micronuclei (MN) assay), mutation analyses (Pig‐a gene mutation assay), and levels of DNA lesions (Comet assay, single‐strand breaks (ssb), alkali labile sites (als), oxidized DNA bases). Ionising radiation (ca. 3 Gy) induced genotoxic effects dependent on the dose rate. Chromosomal aberrations (MN assay) increased 3‐ and 10‐fold after chronic LDR and acute HDR, respectively. Phenotypic mutation frequencies as well as DNA lesions (ssb/als) were modulated after acute HDR but not after chronic LDR. The ApcMin/+ genotype did not influence the outcome in any of the investigated endpoints. The results herein will add to the scant data available on genotoxic effects following chronic LDR of ionising radiation. Environ. Mol. Mutagen. 58:560–569, 2017. © 2017 The Authors Environmental and Molecular Mutagenesis published by Wiley Periodicals, Inc. on behalf of Environmental Mutagen Society PMID:28856770

Effects of low-level chronic irradiation on radiosensitivity of mammals: modeling and experimental studies

NASA Astrophysics Data System (ADS)

Smirnova, O. A.; Yonezawa, M.

Effects of low dose rate chronic irradiation on radiosensitivity of mammals mice are studied by experimental and modeling methods Own and reference experiments show that priming chronic low-level short-term and long-term exposures to radiation induce respectively elevated radiosensitivity and lowered radiosensitivity radioresistance in mice The manifestation of these radiosensitization and radioprotection effects are respectively increased and decreased mortality of preirradiated specimens after challenge acute irradiation in comparison with those for previously unexposed ones Taking into account that the reason of the animal death in the experiments was the hematopoietic syndrome the biophysical models of the critical body system hematopoiesis are used to simulate the dynamics of the major hematopoietic lines in mice exposed to challenge acute irradiation following the chronic one Juxtaposition of the modeling results obtained and the relevant experimental data shows that the radiosensitization effect of chronic low-level short-term less than 1 month preirradiation on mice is due to increased radiosensitivity of lymphopoietic granulocytopoietic and erythropoietic systems accompanied by increased or close to the normal level radiosensitivity of thrombocytopoietic system which are induced by the above-indicated exposure In turn the radioprotection effect of chronic low-level long-term more than 1 month preirradiation on mice is caused by decreased radiosensitivity radioresistance of the granulocytopoietic system which

4-aminopyridine reverses ataxia and cerebellar firing deficiency in a mouse model of spinocerebellar ataxia type 6

PubMed Central

Jayabal, Sriram; Chang, Hui Ho Vanessa; Cullen, Kathleen E.; Watt, Alanna J.

2016-01-01

Spinocerebellar ataxia type 6 (SCA6) is a devastating midlife-onset autosomal dominant motor control disease with no known treatment. Using a hyper-expanded polyglutamine (84Q) knock-in mouse, we found that cerebellar Purkinje cell firing precision was degraded in heterozygous (SCA684Q/+) mice at 19 months when motor deficits are observed. Similar alterations in firing precision and motor control were observed at disease onset at 7 months in homozygous (SCA684Q/84Q) mice, as well as a reduction in firing rate. We further found that chronic administration of the FDA-approved drug 4-aminopyridine (4-AP), which targets potassium channels, alleviated motor coordination deficits and restored cerebellar Purkinje cell firing precision to wildtype (WT) levels in SCA684Q/84Q mice both in acute slices and in vivo. These results provide a novel therapeutic approach for treating ataxic symptoms associated with SCA6. PMID:27381005

4-aminopyridine reverses ataxia and cerebellar firing deficiency in a mouse model of spinocerebellar ataxia type 6.

PubMed

Jayabal, Sriram; Chang, Hui Ho Vanessa; Cullen, Kathleen E; Watt, Alanna J

2016-07-06

Spinocerebellar ataxia type 6 (SCA6) is a devastating midlife-onset autosomal dominant motor control disease with no known treatment. Using a hyper-expanded polyglutamine (84Q) knock-in mouse, we found that cerebellar Purkinje cell firing precision was degraded in heterozygous (SCA6(84Q/+)) mice at 19 months when motor deficits are observed. Similar alterations in firing precision and motor control were observed at disease onset at 7 months in homozygous (SCA6(84Q/84Q)) mice, as well as a reduction in firing rate. We further found that chronic administration of the FDA-approved drug 4-aminopyridine (4-AP), which targets potassium channels, alleviated motor coordination deficits and restored cerebellar Purkinje cell firing precision to wildtype (WT) levels in SCA6(84Q/84Q) mice both in acute slices and in vivo. These results provide a novel therapeutic approach for treating ataxic symptoms associated with SCA6.

Phagocyte NADPH oxidase, but not inducible nitric oxide synthase, is essential for early control of Burkholderia cepacia and chromobacterium violaceum infection in mice.

PubMed

Segal, Brahm H; Ding, Li; Holland, Steven M

2003-01-01

Reactive oxygen and nitrogen intermediates have critical, partially overlapping roles in host defense against a variety of pathogens. Using mice deficient in generating phagocyte superoxide (p47(phox)(-/-)) and mice deficient in generating inducible nitric oxide synthase (iNOS(-/-)), we examined the roles of these reactive species in host defense against Burkholderia cepacia and Chromobacterium violaceum, organisms known to have unusual virulence in chronic granulomatous disease. Intraperitoneal B. cepacia challenge (4.0 x 10(3) to 4.0 x 10(5) organisms/mouse) resulted in mortality in all p47(phox)(-/-) mice, with the survival interval being inversely proportionate to the amount of inoculum. Pretreatment with gamma interferon did not affect survival. C. violaceum was strikingly virulent in p47(phox)(-/-) mice (the 50% lethal dose [LD(50)] was <13 organisms). iNOS(-/-) and wild-type mice were resistant to B. cepacia challenges of at least 10(6) organisms per mouse, and the LD(50) of C. violaceum was between 10(6) and 10(7) organisms per mouse. Consistent with the survival data, numbers of organisms in cultures of B. cepacia from multiple sites were higher for p47(phox)(-/-) mice than for iNOS(-/-) and wild-type mice at day 4 after challenge, but numbers of organisms for different B. cepacia strains varied. The recovery of C. violaceum was strikingly greater at 18 h after challenge for p47(phox)(-/-) mice than for iNOS(-/-) and wild-type mice, in which the organism burdens were virtually nil. In vitro, both B. cepacia and C. violaceum were sensitive to H(2)O(2) and to reactive nitrogen intermediates but the sensitivities of different strains varied significantly. Host defense against B. cepacia and C. violaceum is critically dependent in vivo on reactive oxygen intermediates, and these species are model organisms to further dissect host and pathogen interactions related to the generation and scavenging of microbicidal reactive intermediates.

Impairment of contextual fear extinction by chronic nicotine and withdrawal from chronic nicotine is associated with hippocampal nAChR upregulation.

PubMed

Kutlu, Munir Gunes; Oliver, Chicora; Huang, Peng; Liu-Chen, Lee-Yuan; Gould, Thomas J

2016-10-01

Chronic nicotine and withdrawal from chronic nicotine have been shown to be major modulators of fear learning behavior. Moreover, recent studies from our laboratory have shown that acute nicotine impaired fear extinction and safety learning in mice. However, the effects of chronic nicotine and withdrawal on fear extinction are unknown. Therefore, the current experiments were conducted to investigate the effects of chronic nicotine as well as withdrawal from chronic nicotine on contextual fear extinction in mice. C57BL6/J mice were given contextual fear conditioning training and retention testing during chronic nicotine administration. Mice then received contextual fear extinction either during chronic nicotine or during withdrawal from chronic nicotine. Our results showed that contextual fear extinction was impaired both during chronic nicotine administration and subsequent withdrawal. However, it was also observed that the effects of prior chronic nicotine disappeared after 72 h in withdrawal, a timeline that closely matches with the timing of the chronic nicotine-induced upregulation of hippocampal nicotinic acetylcholine receptor (nAChR) density. Additional experiments found that 4 days, but not 1 day, of continuous nicotine administration upregulated hippocampal nAChRs and impaired contextual fear extinction. These effects disappeared following 72 h withdrawal. Overall, these experiments provide a potential link between nicotine-induced upregulation of hippocampal nAChRs and fear extinction deficits observed in patients with anxiety disorders, which may lead to advancements in the pharmacological treatment methods for this disorder. Copyright © 2016 Elsevier Ltd. All rights reserved.

Effects of Psychosocial Stress on Subsequent Hemorrhagic Shock and Resuscitation in Male Mice.

PubMed

Langgartner, Dominik; Wachter, Ulrich; Hartmann, Clair; Gröger, Michael; Vogt, Josef; Merz, Tamara; McCook, Oscar; Fink, Marina; Kress, Sandra; Georgieff, Michael; Kunze, Julia F; Radermacher, Peter L; Reber, Stefan O; Wepler, Martin

2018-06-08

Hypoxemia and tissue ischemia during hemorrhage as well as formation of oxygen and nitrogen radicals during resuscitation promote hyperinflammation and, consequently, trigger severe multiple-organ-failure (MOF). Individuals diagnosed with stress-related disorders or reporting a life history of psychosocial stress are characterized by chronic low-grade inflammation and a reduced glucocorticoid (GC) signaling. We hypothesized that exposure to chronic psychosocial stress during adulthood prior to hemorrhagic shock increases oxidative/nitrosative stress and therefore the risk of developing MOF in mice. To induce chronic psychosocial stress linked to mild immune activation and reduced GC signaling in male mice, the chronic subordinate colony housing (CSC) paradigm was employed. Single-housed (SHC) mice were used as controls. Subsequently, CSC and SHC mice were exposed to hemorrhagic shock following resuscitation to investigate the effects of prior psychosocial stress load on survival, organ function, metabolism, oxidative/nitrosative stress, and inflammatory readouts. An increased adrenal weight in CSC mice indicates that the stress paradigm reliably worked. However, no effect of prior psychosocial stress on outcome after subsequent hemorrhage and resuscitation could be detected. Chronic psychosocial stress during adulthood is not sufficient to promote hemodynamic complications, organ dysfunction, metabolic disturbances and did not increase the risk of MOF after subsequent hemorrhage and resuscitation. Intravenous norepinephrine to keep target hemodynamics might have led to a certain level of oxidative stress in both groups and, therefore, disguised potential effects of chronic psychosocial stress on organ function after hemorrhagic shock in the present murine trauma model.

Diurnal behavioral and endocrine effects of chronic shaker stress in mice.

PubMed

Dubovicky, Michal; Mach, Mojmir; Key, Mary; Morris, Mariana; Paton, Sara; Lucot, James B

2007-12-01

Experiments were performed in C57BL/6J male mice to determine 1) light/dark effects of acute and chronic shaker stress on open field behavioral patterns and 2) light/dark effects of chronic stress on plasma corticosterone and oxytocin. Shaker stress was applied acutely (15 min) or chronically (3 or 7 days). Mice were tested in the open field in the light or dark phase of the circadian cycle. For the endocrine study, mice were exposed to 3 days of intermittent shaker stress and sacrificed after the last stress event (09:00 or 19:00 h). Acute or chronic shaker stress had no significant effects on intensity of motor activity and rearing of mice tested under either light condition. Mice tested in the dark phase had higher motor activity and exhibited lower anxiety-like behavior as expressed by central zone activities and had higher emotionality as expressed by increased defecation. Chronic stress increased corticosterone with a greater absolute increase in the dark period. However, the percentage stress-induced increase was not different between the day and night periods. The oxytocin response to stress was observed only during the light phase with no change seen at dark phase. These results show that there is a marked difference in the light/dark pituitary stress response with no alteration in stress induced behavioral changes. They also suggest that there are circadian interactions in the endocrine stress axis that are without consequences for open field behavior.

Effects of acute and chronic psychological stress on platelet aggregation in mice.

PubMed

Matsuhisa, Fumikazu; Kitamura, Nobuo; Satoh, Eiki

2014-03-01

Although psychological stress has long been known to alter cardiovascular function, there have been few studies on the effect of psychological stress on platelets, which play a pivotal role in cardiovascular disease. In the present study, we investigated the effects of acute and chronic psychological stress on the aggregation of platelets and platelet cytosolic free calcium concentration ([Ca(2+)]i). Mice were subjected to both transportation stress (exposure to novel environment, psychological stress) and restraint stress (psychological stress) for 2 h (acute stress) or 3 weeks (2 h/day) (chronic stress). In addition, adrenalectomized mice were subjected to similar chronic stress (both transportation and restraint stress for 3 weeks). The aggregation of platelets from mice and [Ca(2+)]i was determined by light transmission assay and fura-2 fluorescence assay, respectively. Although acute stress had no effect on agonist-induced platelet aggregation, chronic stress enhanced the ability of the platelet agonists thrombin and ADP to stimulate platelet aggregation. However, chronic stress failed to enhance agonist-induced increase in [Ca(2+)]i. Adrenalectomy blocked chronic stress-induced enhancement of platelet aggregation. These results suggest that chronic, but not acute, psychological stress enhances agonist-stimulated platelet aggregation independently of [Ca(2+)]i increase, and the enhancement may be mediated by stress hormones secreted from the adrenal glands.

Fluoxetine regulates mTOR signalling in a region-dependent manner in depression-like mice.

PubMed

Liu, Xiao-Long; Luo, Liu; Mu, Rong-Hao; Liu, Bin-Bin; Geng, Di; Liu, Qing; Yi, Li-Tao

2015-11-02

Previous studies have demonstrated that the mammalian target of rapamycin (mTOR) signaling pathway has an important role in ketamine-induced, rapid antidepressant effects despite the acute administration of fluoxetine not affecting mTOR phosphorylation in the brain. However, the effects of long-term fluoxetine treatment on mTOR modulation have not been assessed to date. In the present study, we examined whether fluoxetine, a type of commonly used antidepressant agent, alters mTOR signaling following chronic administration in different brain regions, including the frontal cortex, hippocampus, amygdala and hypothalamus. We also investigated whether fluoxetine enhanced synaptic protein levels in these regions via the activation of the mTOR signaling pathway and its downstream regulators, p70S6K and 4E-BP-1. The results indicated that chronic fluoxetine treatment attenuated the chronic, unpredictable, mild stress (CUMS)-induced mTOR phosphorylation reduction in the hippocampus and amygdala of mice but not in the frontal cortex or the hypothalamus. Moreover, the CUMS-decreased PSD-95 and synapsin I levels were reversed by fluoxetine, and these effects were blocked by rapamycin only in the hippocampus. In conclusion, our findings suggest that chronic treatment with fluoxetine can induce synaptic protein expression by activating the mTOR signaling pathway in a region-dependent manner and mainly in the hippocampus.

Chronic Alcohol Ingestion Worsens Survival and Alters Gut Epithelial Apoptosis and Cd8+ T Cell Function after Pseudomonas Aeruginosa Pneumonia-Induced Sepsis.

PubMed

Klingensmith, Nathan J; Fay, Katherine T; Lyons, John D; Chen, Ching-Wen; Otani, Shunsuke; Liang, Zhe; Chihade, Deena B; Burd, Eileen M; Ford, Mandy L; Coopersmith, Craig M

2018-04-16

Mortality is higher in septic patients with a history of alcohol use disorder than in septic patients without a history of chronic alcohol usage. We have previously described a model of chronic alcohol ingestion followed by sepsis from cecal ligation and puncture in which alcohol-fed septic mice have higher mortality than water-fed septic mice, associated with altered gut integrity and increased production of TNF and IFNγ by splenic CD4 T cells without alterations in CD8 T cell function. The purpose of this study was to determine whether this represents a common host response to the combination of alcohol and sepsis by creating a new model in which mice with chronic alcohol ingestion were subjected to a different model of sepsis. C57Bl/6 mice were randomized to receive either alcohol or water for 12 weeks and then subjected to Pseudomonas aeruginosa pneumonia. Mice were sacrificed either 24 hours after the onset of sepsis or followed for survival. Alcohol-fed septic mice had significantly higher 7-day mortality than water-fed septic mice (96% vs 58%). This was associated with a 5-fold increase in intestinal apoptosis in alcohol-fed septic animals, accompanied by an increase in the pro-apoptotic protein Bax. Serum IL-6 levels were higher and IL-2 levels were lower in alcohol-fed septic mice. In contrast, CD8 T cell frequency was lower in alcohol-fed mice than water-fed septic mice, associated with increased production of IFNγ and TNF in stimulated splenocytes. No significant differences were noted in CD4 T cells, lung injury or bacteremia. Mice with chronic alcohol ingestion thus have increased mortality regardless of their septic insult, associated with changes in both the gut and the immune system.

Chronic consumption of distilled sugarcane spirit induces anxiolytic-like effects in mice.

PubMed

Sena, Maria Clecia P; Nunes, Fabíola C; Salvadori, Mirian G S Stiebbe; Carvalho, Cleyton Charles D; Morais, Liana Clebia S L; Braga, Valdir A

2011-01-01

Chronic ethanol consumption is a major public health problem throughout the world. We investigated the anxiolytic-like effects and the possible ever injury induced by the chronic consumption of ethanol or sugarcane spirit in mice. Adult mice were exposed to a two-bottle free-choice paradigm for 6 weeks. The mice in Group A (n = 16) had access to sugarcane spirit + distilled water, the mice in Group B (n = 15) had access to ethanol + distilled water, and the mice in Group C (control, n = 14) had access to distilled water + distilled water. The ethanol content in the beverages offered to Groups A and B was 2% for the first week, 5% for the second week and 10% for the remaining four weeks. At the end of the experimental period, the mice were evaluated using the elevated-plus maze and the hole-board test to assess their anxiety-related behaviors. We also determined the serum aspartate aminotransferase and alanine aminotransferase levels. In the elevated-plus maze, the time spent in the open arms was increased in the mice exposed to chronic ethanol (32 ± 8 vs. 7 ± 2 s, n = 9) or sugarcane spirit (36 ± 9 vs. 7 ± 2 s, n = 9) compared to the controls. In the hole-board test, the mice exposed to ethanol or sugarcane spirit displayed increases in their head-dipping frequency (16 ± 1 for the control group, 27 ± 2 for the ethanol group, and 31 ± 3 for the sugarcane-spirit group; n = 9 for each group). In addition, the mice exposed to sugarcane spirit displayed an increase in the aspartate aminotransferase / alanine aminotransferase ratio compared to the ethanol group (1.29 ± 0.17 for the control group and 2.67 ± 0.17 for the sugarcane spirit group; n = 8 for each group). The chronic consumption of sugarcane-spirit produces liver injury and anxiolytic-like effects and the possible liver injury in mice.

Immature morphological properties in subcellular-scale structures in the dentate gyrus of Schnurri-2 knockout mice: a model for schizophrenia and intellectual disability.

PubMed

Nakao, Akito; Miyazaki, Naoyuki; Ohira, Koji; Hagihara, Hideo; Takagi, Tsuyoshi; Usuda, Nobuteru; Ishii, Shunsuke; Murata, Kazuyoshi; Miyakawa, Tsuyoshi

2017-12-12

Accumulating evidence suggests that subcellular-scale structures such as dendritic spine and mitochondria may be involved in the pathogenesis/pathophysiology of schizophrenia and intellectual disability. Previously, we proposed mice lacking Schnurri-2 (Shn2; also called major histocompatibility complex [MHC]-binding protein 2 [MBP-2], or human immunodeficiency virus type I enhancer binding protein 2 [HIVEP2]) as a schizophrenia and intellectual disability model with mild chronic inflammation. In the mutants' brains, there are increases in C4b and C1q genes, which are considered to mediate synapse elimination during postnatal development. However, morphological properties of subcellular-scale structures such as dendritic spine in Shn2 knockout (KO) mice remain unknown. In this study, we conducted three-dimensional morphological analyses in subcellular-scale structures in dentate gyrus granule cells of Shn2 KO mice by serial block-face scanning electron microscopy. Shn2 KO mice showed immature dendritic spine morphology characterized by increases in spine length and decreases in spine diameter. There was a non-significant tendency toward decrease in spine density of Shn2 KO mice over wild-type mice, and spine volume was indistinguishable between genotypes. Shn2 KO mice exhibited a significant reduction in GluR1 expression and a nominally significant decrease in SV2 expression, while PSD95 expression had a non-significant tendency to decrease in Shn2 KO mice. There were significant decreases in dendrite diameter, nuclear volume, and the number of constricted mitochondria in the mutants. Additionally, neuronal density was elevated in Shn2 KO mice. These results suggest that Shn2 KO mice serve as a unique tool for investigating morphological abnormalities of subcellular-scale structures in schizophrenia, intellectual disability, and its related disorders.

OSO paradigm--A rapid behavioral screening method for acute psychosocial stress reactivity in mice.

PubMed

Brzózka, M M; Unterbarnscheidt, T; Schwab, M H; Rossner, M J

2016-02-09

Chronic psychosocial stress is an important environmental risk factor for the development of psychiatric diseases. However, studying the impact of chronic psychosocial stress in mice is time consuming and thus not optimally suited to 'screen' increasing numbers of genetically manipulated mouse models for psychiatric endophenotypes. Moreover, many studies focus on restraint stress, a strong physical stressor with limited relevance for psychiatric disorders. Here, we describe a simple and a rapid method based on the resident-intruder paradigm to examine acute effects of mild psychosocial stress in mice. The OSO paradigm (open field--social defeat--open field) compares behavioral consequences on locomotor activity, anxiety and curiosity before and after exposure to acute social defeat stress. We first evaluated OSO in male C57Bl/6 wildtype mice where a single episode of social defeat reduced locomotor activity, increased anxiety and diminished exploratory behavior. Subsequently, we applied the OSO paradigm to mouse models of two schizophrenia (SZ) risk genes. Transgenic mice with neuronal overexpression of Neuregulin-1 (Nrg1) type III showed increased risk-taking behavior after acute stress exposure suggesting that NRG1 dysfunction is associated with altered affective behavior. In contrast, Tcf4 transgenic mice displayed a normal stress response which is in line with the postulated predominant contribution of TCF4 to cognitive deficits of SZ. In conclusion, the OSO paradigm allows for rapid screening of selected psychosocial stress-induced behavioral endophenotypes in mouse models of psychiatric diseases. Copyright © 2015 IBRO. Published by Elsevier Ltd. All rights reserved.

Increased TRPV4 expression in urinary bladder and lumbosacral dorsal root ganglia in mice with chronic overexpression of NGF in urothelium.

PubMed

Girard, Beatrice M; Merrill, Liana; Malley, Susan; Vizzard, Margaret A

2013-10-01

Transient receptor potential vanilloid (TRPV) family member 4 (TRPV4) expression has been demonstrated in urothelial cells and dorsal root ganglion (DRG) neurons, and roles in normal micturition reflexes as well as micturition dysfunction have been suggested. TRP channel expression and function is dependent upon target tissue expression of growth factors. These studies expand upon the target tissue dependence of TRPV4 expression in the urinary bladder and lumbosacral DRG using a recently characterized transgenic mouse model with chronic overexpression of nerve growth factor (NGF-OE) in the urothelium. Immunohistochemistry with image analyses, real-time quantitative polymerase chain reaction, and Western blotting were used to determine TRPV4 protein and transcript expression in the urinary bladder (urothelium + suburothelium, detrusor) and lumbosacral DRG from littermate wild-type (WT) and NGF-OE mice. Antibody specificity controls were performed in TRPV4(-/-) mice. TRPV4 transcript and protein expression was significantly (p ≤ 0.001) increased in the urothelium + suburothelium and suburothelial nerve plexus of the urinary bladder and in small- and medium-sized lumbosacral (L1, L2, L6-S1) DRG cells from NGF-OE mice compared to littermate WT mice. NGF-OE mice exhibit significant (p ≤ 0.001) increases in NGF transcript and protein in the urothelium + suburothelium and lumbosacral DRG. These studies demonstrate regulation of TRPV4 expression by NGF in lower urinary tract tissues. Ongoing studies are characterizing the functional roles of TRPV4 expression in the sensory limb (DRG, urothelium) of the micturition reflex.

Proteomic Profiling of Liver and Plasma in Chronic Ethanol Feeding Model of Hepatic Alcohol Dehydrogenase-Deficient Deer Mice.

PubMed

Bhopale, Kamlesh K; Amer, Samir M; Kaphalia, Lata; Soman, Kizhake V; Wiktorowicz, John E; Shakeel Ansari, Ghulam A; Kaphalia, Bhupendra S

2017-10-01

Chronic alcohol abuse, a major risk factor for such diseases as hepatitis and cirrhosis, impairs hepatic alcohol dehydrogenase (ADH; key ethanol [EtOH]-metabolizing enzyme). Therefore, differentially altered hepatic and plasma proteomes were identified in chronic EtOH feeding model of hepatic ADH-deficient (ADH - ) deer mice to understand the metabolic basis of alcoholic liver disease (ALD). ADH - deer mice were fed 3.5 g% EtOH via Lieber-DeCarli liquid diet daily for 3 months and histology of the liver assessed. Liver and plasma proteins were separated by 2-dimensional gel electrophoresis. The proteins differentially expressed were identified by matrix-assisted laser desorption ionization-time of flight mass spectrometry. Histology of the liver showed panlobular steatosis and infiltration of T lymphocytes. Using the criteria of ≥1.5 for fold change (p-value ≤0.05) with expectation value (E ≤10 -3 ) and protein score (≥64), 18 proteins in the livers and 5 in the plasma of EtOH-fed mice were differentially expressed and identified. Prolyl 4-hydroxylase, cytochrome b-5, endo A cytokeratin, ATP synthase, heat-shock 70 kD proteins, enoyl CoA hydratase, stress-70 protein, peroxiredoxin 1, and ornithine carbamoyl transferase were up-regulated in the livers. However, carbonic anhydrase 3, mitochondrial ATP synthase, aldolase 2, actin γ, laminin receptor, and carbamoyl phosphate synthase were down-regulated. Contrary to the increased expression of creatine kinase M-type, a decreased expression of serine protease inhibitor A3A precursor, sulfated glycoprotein-2 (clusterin), and apolipoprotein E isoforms were found in the plasma of EtOH group. Chronic EtOH feeding in ADH - deer mice causes steatosis and infiltration of T lymphocytes in the livers along with increased expression of proteins involved in endoplasmic reticulum (ER) stress, fibrosis, fatty acid β oxidation and biogenesis, and decreased expression of proteins involved in ATP synthesis, carbohydrate metabolism, in cell regulation and architecture. Reduced expression of various carrier proteins as found in the plasma of EtOH group has a biomarker potential. Copyright © 2017 by the Research Society on Alcoholism.

RNA-Seq analysis of chikungunya virus infection and identification of granzyme A as a major promoter of arthritic inflammation

PubMed Central

Schroder, Wayne A.; Ellis, Jonathan J.; Cumming, Helen E.; Poo, Yee Suan; Hertzog, Paul J.; Di Giallonardo, Francesca; Hueston, Linda; Le Grand, Roger; Tang, Bing; Gardner, Joy; Mahalingam, Suresh; Bird, Phillip I.

2017-01-01

Chikungunya virus (CHIKV) is an arthritogenic alphavirus causing epidemics of acute and chronic arthritic disease. Herein we describe a comprehensive RNA-Seq analysis of feet and lymph nodes at peak viraemia (day 2 post infection), acute arthritis (day 7) and chronic disease (day 30) in the CHIKV adult wild-type mouse model. Genes previously shown to be up-regulated in CHIKV patients were also up-regulated in the mouse model. CHIKV sequence information was also obtained with up to ≈8% of the reads mapping to the viral genome; however, no adaptive viral genome changes were apparent. Although day 2, 7 and 30 represent distinct stages of infection and disease, there was a pronounced overlap in up-regulated host genes and pathways. Type I interferon response genes (IRGs) represented up to ≈50% of up-regulated genes, even after loss of type I interferon induction on days 7 and 30. Bioinformatic analyses suggested a number of interferon response factors were primarily responsible for maintaining type I IRG induction. A group of genes prominent in the RNA-Seq analysis and hitherto unexplored in viral arthropathies were granzymes A, B and K. Granzyme A-/- and to a lesser extent granzyme K-/-, but not granzyme B-/-, mice showed a pronounced reduction in foot swelling and arthritis, with analysis of granzyme A-/- mice showing no reductions in viral loads but reduced NK and T cell infiltrates post CHIKV infection. Treatment with Serpinb6b, a granzyme A inhibitor, also reduced arthritic inflammation in wild-type mice. In non-human primates circulating granzyme A levels were elevated after CHIKV infection, with the increase correlating with viral load. Elevated granzyme A levels were also seen in a small cohort of human CHIKV patients. Taken together these results suggest granzyme A is an important driver of arthritic inflammation and a potential target for therapy. Trial Registration: ClinicalTrials.gov NCT00281294 PMID:28207896

Coriander Leaf Extract Exerts Antioxidant Activity and Protects Against UVB-Induced Photoaging of Skin by Regulation of Procollagen Type I and MMP-1 Expression

PubMed Central

Hwang, Eunson; Lee, Do-Gyeong; Park, Sin Hee; Oh, Myung Sook

2014-01-01

Abstract Ultraviolet (UV) radiation causes photodamage to the skin, which, in turn, leads to depletion of the dermal extracellular matrix and chronic alterations in skin structure. Skin wrinkles are associated with collagen synthesis and matrix metalloproteinase-1 (MMP-1) activity. Coriandrum sativum L. (coriander leaf, cilantro; CS) has been used as a herbal medicine for the treatment of diabetes, hyperlipidemia, liver disease, and cancer. In this study, we examined whether CS ethanol extract (CSE) has protective effects against UVB-induced skin photoaging in normal human dermal fibroblasts (NHDF) in vitro and in the skin of hairless mice in vivo. The main component of CSE, linolenic acid, was determined by gas chromatography-mass spectroscopy. We measured the cellular levels of procollagen type I and MMP-1 using ELISA in NHDF cells after UVB irradiation. NHDF cells that were treated with CSE after UVB irradiation exhibited higher procollagen type I production and lower levels of MMP-1 than untreated cells. We found that the activity of transcription factor activator protein-1 (AP-1) was also inhibited by CSE treatment. We measured the epidermal thickness, dermal collagen fiber density, and procollagen type I and MMP-1 levels in photo-aged mouse skin in vivo using histological staining and western blot analysis. Our results showed that CSE-treated mice had thinner epidermal layers and denser dermal collagen fibers than untreated mice. On a molecular level, it was further confirmed that CSE-treated mice had lower MMP-1 levels and higher procollagen type I levels than untreated mice. Our results support the potential of C. sativum L. to prevent skin photoaging. PMID:25019675

Coriander leaf extract exerts antioxidant activity and protects against UVB-induced photoaging of skin by regulation of procollagen type I and MMP-1 expression.

PubMed

Hwang, Eunson; Lee, Do-Gyeong; Park, Sin Hee; Oh, Myung Sook; Kim, Sun Yeou

2014-09-01

Ultraviolet (UV) radiation causes photodamage to the skin, which, in turn, leads to depletion of the dermal extracellular matrix and chronic alterations in skin structure. Skin wrinkles are associated with collagen synthesis and matrix metalloproteinase-1 (MMP-1) activity. Coriandrum sativum L. (coriander leaf, cilantro; CS) has been used as a herbal medicine for the treatment of diabetes, hyperlipidemia, liver disease, and cancer. In this study, we examined whether CS ethanol extract (CSE) has protective effects against UVB-induced skin photoaging in normal human dermal fibroblasts (NHDF) in vitro and in the skin of hairless mice in vivo. The main component of CSE, linolenic acid, was determined by gas chromatography-mass spectroscopy. We measured the cellular levels of procollagen type I and MMP-1 using ELISA in NHDF cells after UVB irradiation. NHDF cells that were treated with CSE after UVB irradiation exhibited higher procollagen type I production and lower levels of MMP-1 than untreated cells. We found that the activity of transcription factor activator protein-1 (AP-1) was also inhibited by CSE treatment. We measured the epidermal thickness, dermal collagen fiber density, and procollagen type I and MMP-1 levels in photo-aged mouse skin in vivo using histological staining and western blot analysis. Our results showed that CSE-treated mice had thinner epidermal layers and denser dermal collagen fibers than untreated mice. On a molecular level, it was further confirmed that CSE-treated mice had lower MMP-1 levels and higher procollagen type I levels than untreated mice. Our results support the potential of C. sativum L. to prevent skin photoaging.

N-Acetyl Cysteine does not prevent liver toxicity from chronic low dose plus sub-acute high dose paracetamol exposure in young or old mice

PubMed Central

Kane, Alice-Elizabeth; Huizer-Pajkos, Aniko; Mach, John; McKenzie, Catriona; Mitchell, Sarah-Jayne; de Cabo, Rafael; Jones, Brett; Cogger, Victoria; Le Couteur, David G; Hilmer, Sarah-Nicole

2016-01-01

Paracetamol is an analgesic commonly used by people of all ages, which is well documented to cause severe hepatotoxicity with acute over-exposures. The risk of hepatotoxicity from non-acute paracetamol exposures is less extensively studied, and this is the exposure most common in older adults. Evidence on the effectiveness of N-acetyl cysteine (NAC) for non-acute paracetamol exposures, in any age group, is lacking. This study aimed to examine the effect of long-term exposure to therapeutic doses of paracetamol and sub-acute paracetamol over-exposure, in young and old mice, and to investigate whether NAC was effective at preventing paracetamol hepatotoxicity induced by these exposures. Young and old male C57BL/6 mice were fed a paracetamol-containing (1.33g/kg food) or control diet for 6 weeks. Mice were then dosed orally 8 times over 3 days with additional paracetamol (250mg/kg) or saline, followed by either one or two doses of oral NAC (1200mg/kg) or saline. Chronic low-dose paracetamol exposure did not cause hepatotoxicity in young or old mice, measured by serum alanine aminotransferase (ALT) elevation, and confirmed by histology and a DNA fragmentation assay. Sub-acute paracetamol exposure caused significant hepatotoxicity in young and old mice, measured by biochemistry (ALT) and histology. Neither a single nor double dose of NAC protected against this toxicity from sub-acute paracetamol in young or old mice. This finding has important clinical implications for treating toxicity due to different paracetamol exposure types in patients of all ages, and implies a need to develop new treatments for sub-acute paracetamol toxicity. PMID:26821200

Detection of genotoxic and non-genotoxic carcinogens in Xpc(-/-)p53(+/-) mice.

PubMed

Melis, Joost P M; Speksnijder, Ewoud N; Kuiper, Raoul V; Salvatori, Daniela C F; Schaap, Mirjam M; Maas, Saskia; Robinson, Joke; Verhoef, Aart; van Benthem, Jan; Luijten, Mirjam; van Steeg, Harry

2013-01-15

An accurate assessment of the carcinogenic potential of chemicals and pharmaceutical drugs is essential to protect humans and the environment. Therefore, substances are extensively tested before they are marketed to the public. Currently, the rodent two-year bioassay is still routinely used to assess the carcinogenic potential of substances. However, over time it has become clear that this assay yields false positive results and also has several economic and ethical drawbacks including the use of large numbers of animals, the long duration, and the high cost. The need for a suitable alternative assay is therefore high. Previously, we have proposed the Xpa*p53 mouse model as a very suitable alternative to the two-year bioassay. We now show that the Xpc*p53 mouse model preserves all the beneficial traits of the Xpa*p53 model for sub-chronic carcinogen identification and can identify both genotoxic and non-genotoxic carcinogens. Moreover, Xpc*p53 mice appear to be more responsive than Xpa*p53 mice towards several genotoxic and non-genotoxic carcinogens. Furthermore, Xpc*p53 mice are far less sensitive than Xpa*p53 mice for the toxic activity of DNA damaging agents and as such clearly respond in a similar way as wild type mice do. These advantageous traits of the Xpc*p53 model make it a better alternative for in vivo carcinogen testing than Xpa*p53. This pilot study suggests that Xpc*p53 mice are suited for routine sub-chronic testing of both genotoxic and non-genotoxic carcinogens and as such represent a suitable alternative to possibly replace the murine life time cancer bioassay. Copyright © 2012 Elsevier Inc. All rights reserved.

Construct and face validity of a new model for the three-hit theory of depression using PACAP mutant mice on CD1 background.

PubMed

Farkas, József; Kovács, László Á; Gáspár, László; Nafz, Anna; Gaszner, Tamás; Ujvári, Balázs; Kormos, Viktória; Csernus, Valér; Hashimoto, Hitoshi; Reglődi, Dóra; Gaszner, Balázs

2017-06-23

Major depression is a common cause of chronic disability. Despite decades of efforts, no equivocally accepted animal model is available for studying depression. We tested the validity of a new model based on the three-hit concept of vulnerability and resilience. Genetic predisposition (hit 1, mutation of pituitary adenylate cyclase-activating polypeptide, PACAP gene), early-life adversity (hit 2, 180-min maternal deprivation, MD180) and chronic variable mild stress (hit 3, CVMS) were combined. Physical, endocrinological, behavioral and functional morphological tools were used to validate the model. Body- and adrenal weight changes as well as corticosterone titers proved that CVMS was effective. Forced swim test indicated increased depression in CVMS PACAP heterozygous (Hz) mice with MD180 history, accompanied by elevated anxiety level in marble burying test. Corticotropin-releasing factor neurons in the oval division of the bed nucleus of the stria terminalis showed increased FosB expression, which was refractive to CVMS exposure in wild-type and Hz mice. Urocortin1 neurons became over-active in CMVS-exposed PACAP knock out (KO) mice with MD180 history, suggesting the contribution of centrally projecting Edinger-Westphal nucleus to the reduced depression and anxiety level of stressed KO mice. Serotoninergic neurons of the dorsal raphe nucleus lost their adaptation ability to CVMS in MD180 mice. In conclusion, the construct and face validity criteria suggest that MD180 PACAP HZ mice on CD1 background upon CVMS may be used as a reliable model for the three-hit theory. Copyright © 2017 IBRO. Published by Elsevier Ltd. All rights reserved.

Surfactant protein D attenuates sub-epithelial fibrosis in allergic airways disease through TGF-β.

PubMed

Ogawa, Hirohisa; Ledford, Julie G; Mukherjee, Sambuddho; Aono, Yoshinori; Nishioka, Yasuhiko; Lee, James J; Izumi, Keisuke; Hollingsworth, John W

2014-11-29

Surfactant protein D (SP-D) can regulate both innate and adaptive immunity. Recently, SP-D has been shown to contribute to the pathogenesis of airway allergic inflammation and bleomycin-induced pulmonary fibrosis. However, in allergic airways disease, the role of SP-D in airway remodeling remains unknown. The objective of this study was to determine the contribution of functional SP-D in regulating sub-epithelial fibrosis in a mouse chronic house dust mite model of allergic airways disease. C57BL/6 wild-type (WT) and SP-D-/- mice (C57BL/6 background) were chronically challenged with house dust mite antigen (Dermatophagoides pteronyssinus, Dp). Studies with SP-D rescue and neutralization of TGF-β were conducted. Lung histopathology and the concentrations of collagen, growth factors, and cytokines present in the airspace and lung tissue were determined. Cultured eosinophils were stimulated by Dp in presence or absence of SP-D. Dp-challenged SP-D-/- mice demonstrate increased sub-epithelial fibrosis, collagen production, eosinophil infiltration, TGF-β1, and IL-13 production, when compared to Dp-challenged WT mice. By immunohistology, we detected an increase in TGF-β1 and IL-13 positive eosinophils in SP-D-/- mice. Purified eosinophils stimulated with Dp produced TGF-β1 and IL-13, which was prevented by co-incubation with SP-D. Additionally, treatment of Dp challenged SP-D-/- mice with exogenous SP-D was able to rescue the phenotypes observed in SP-D-/- mice and neutralization of TGF-β1 reduced sub-epithelial fibrosis in Dp-challenged SP-D-/- mice. These data support a protective role for SP-D in the pathogenesis of sub-epithelial fibrosis in a mouse model of allergic inflammation through regulation of eosinophil-derived TGF-β.

Chronic mild stress increases alcohol intake in mice with low dopamine D2 receptor levels.

PubMed

Delis, Foteini; Thanos, Panayotis K; Rombola, Christina; Rosko, Lauren; Grandy, David; Wang, Gene-Jack; Volkow, Nora D

2013-02-01

Alcohol use disorders emerge from a complex interaction between environmental and genetic factors. Stress and dopamine D2 receptor levels (DRD2) have been shown to play a central role in alcoholism. To better understand the interactions between DRD2 and stress in ethanol intake behavior, we subjected Drd2 wild-type (+/+), heterozygous (+/-), and knockout (-/-) mice to 4 weeks of chronic mild stress (CMS) and to an ethanol two-bottle choice during CMS weeks 2-4. Prior to and at the end of the experiment, the animals were tested in the forced swim and open field tests. We measured ethanol intake and preference, immobility in the force swim test, and activity in the open field. We show that under no CMS, Drd2+/- and Drd2-/- mice had lower ethanol intake and preference compared with Drd2+/+. Exposure to CMS decreased ethanol intake and preference in Drd2+/+ and increased them in Drd2+/- and Drd2-/- mice. At baseline, Drd2+/- and Drd2-/- mice had significantly lower activity in the open field than Drd2+/+, whereas no genotype differences were observed in the forced swim test. Exposure to CMS increased immobility during the forced swim test in Drd2+/- mice, but not in Drd2+/+ or Drd2-/- mice, and ethanol intake reversed this behavior. No changes were observed in open field test measures. These findings suggest that in the presence of a stressful environment, low DRD2 levels are associated with increased ethanol intake and preference and that under this condition, increased ethanol consumption could be used as a strategy to alleviate negative mood. (PsycINFO Database Record (c) 2013 APA, all rights reserved).

Lack of hepcidin ameliorates anemia and improves growth in an adenine-induced mouse model of chronic kidney disease

PubMed Central

Sureshbabu, Angara; Doty, Steve B.; Zhu, Yuan-Shan; Patino, Edwin; Cunningham-Rundles, Susanna; Choi, Mary E.; Boskey, Adele; Rivella, Stefano

2016-01-01

Growth delay is common in children with chronic kidney disease (CKD), often associated with poor quality of life. The role of anemia in uremic growth delay is poorly understood. Here we describe an induction of uremic growth retardation by a 0.2% adenine diet in wild-type (WT) and hepcidin gene (Hamp) knockout (KO) mice, compared with their respective littermates fed a regular diet. Experiments were started at weaning (3 wk). After 8 wk, blood was collected and mice were euthanized. Adenine-fed WT mice developed CKD (blood urea nitrogen 82.8 ± 11.6 mg/dl and creatinine 0.57 ± 0.07 mg/dl) and were 2.1 cm shorter compared with WT controls. WT adenine-fed mice were anemic and had low serum iron, elevated Hamp, and elevated IL6 and TNF-α. WT adenine-fed mice had advanced mineral bone disease (serum phosphorus 16.9 ± 3.1 mg/dl and FGF23 204.0 ± 115.0 ng/ml) with loss of cortical and trabecular bone volume seen on microcomputed tomography. Hamp disruption rescued the anemia phenotype resulting in improved growth rate in mice with CKD, thus providing direct experimental evidence of the relationship between Hamp pathway and growth impairment in CKD. Hamp disruption ameliorated CKD-induced growth hormone-insulin-like growth factor 1 axis derangements and growth plate alterations. Disruption of Hamp did not mitigate the development of uremia, inflammation, and mineral and bone disease in this model. Taken together, these results indicate that an adenine diet can be successfully used to study growth in mice with CKD. Hepcidin appears to be related to pathways of growth retardation in CKD suggesting that investigation of hepcidin-lowering therapies in juvenile CKD is warranted. PMID:27440777

Late-intervention study with ebselen in an experimental model of type 1 diabetic nephropathy.

PubMed

Tan, S M; Sharma, A; Stefanovic, N; de Haan, J B

2015-03-01

Previous studies have shown that preventive treatment with the antioxidant, ebselen, in experimental models of type 1 diabetic nephropathy resulted in an attenuation of structural and functional damage in the kidney. However, evidence for the effectiveness of ebselen in late-intervention studies is lacking. Thus, we aimed to investigate the effects of ebselen in attenuating established renal injury in type 1 diabetic nephropathy using the Akita mouse model. Baseline blood glucose and albumin-to-creatinine ratio (ACR) were measured in wild-type (WT) and heterozygous Akita mice at 9 weeks of age. At 10 weeks of age, WT and Akita mice were randomized to receive either vehicle (5% carboxymethyl cellulose) or ebselen by oral gavage at 10mg/kg twice daily. Kidney and urine were collected after 16 weeks of treatment with ebselen for histological and functional analyses. At 9 weeks of age, Akita mice displayed well-established renal dysfunction with significant increases in ACR and urinary 8-hydroxy-2'-deoxyguanosine (8-OHdG) levels when compared with WT controls. After 16 weeks of treatment with ebselen, oxidative stress, as measured by nitrotyrosine immunostaining and urinary 8-OHdG levels, was significantly reduced in the Akita mice. Furthermore, gene expression of the major reactive oxygen species-producing nicotinamide adenine dinucleotide phosphate enzyme, Nox4, was also reduced by ebselen. However, ebselen had no effect on ACR and glomerulosclerosis. Chronic treatment with ebselen significantly reduced oxidative stress in the Akita mice. However, ebselen failed to attenuate functional or structural kidney damage in this late-intervention study using the Akita mouse model.

The antifibrinolytic drug tranexamic acid reduces liver injury and fibrosis in a mouse model of chronic bile duct injury.

PubMed

Joshi, Nikita; Kopec, Anna K; Towery, Keara; Williams, Kurt J; Luyendyk, James P

2014-06-01

Hepatic fibrin deposition has been shown to inhibit hepatocellular injury in mice exposed to the bile duct toxicant α-naphthylisothiocyanate (ANIT). Degradation of fibrin clots by fibrinolysis controls the duration and extent of tissue fibrin deposition. Thus, we sought to determine the effect of treatment with the antifibrinolytic drug tranexamic acid (TA) and plasminogen activator inhibitor-1 (PAI-1) deficiency on ANIT-induced liver injury and fibrosis in mice. Plasmin-dependent lysis of fibrin clots was impaired in plasma from mice treated with TA (1200 mg/kg i.p., administered twice daily). Prophylactic TA administration reduced hepatic inflammation and hepatocellular necrosis in mice fed a diet containing 0.025% ANIT for 2 weeks. Hepatic type 1 collagen mRNA expression and deposition increased markedly in livers of mice fed ANIT diet for 4 weeks. To determine whether TA treatment could inhibit this progression of liver fibrosis, mice were fed ANIT diet for 4 weeks and treated with TA for the last 2 weeks. Interestingly, TA treatment largely prevented increased deposition of type 1 collagen in livers of mice fed ANIT diet for 4 weeks. In contrast, biliary hyperplasia/inflammation and liver fibrosis were significantly increased in PAI-1(-/-) mice fed ANIT diet for 4 weeks. Overall, the results indicate that fibrinolytic activity contributes to ANIT diet-induced liver injury and fibrosis in mice. In addition, these proof-of-principle studies suggest the possibility that therapeutic intervention with an antifibrinolytic drug could form a novel strategy to prevent or reduce liver injury and fibrosis in patients with liver disease.

The role of tumour necrosis factor-α and tumour necrosis factor receptor signalling in inflammation-associated systemic genotoxicity

PubMed Central

Westbrook, Aya M.; Wei, Bo; Hacke, Katrin; Xia, Menghang; Braun, Jonathan; Schiestl, Robert H.

2012-01-01

Chronic inflammatory diseases are characterised by systemically elevated levels of tumour necrosis factor (TNF)-α, a proinflammatory cytokine with pleiotropic downstream effects. We have previously demonstrated increased genotoxicity in peripheral leukocytes and various tissues in models of intestinal inflammation. In the present study, we asked whether TNF-α is sufficient to induce DNA damage systemically, as observed in intestinal inflammation, and whether tumour necrosis factor receptor (TNFR) signalling would be necessary for the resultant genotoxicity. In the wild-type mice, 500 ng per mouse of TNF-α was sufficient to induce DNA damage to multiple cell types and organs 1-h post-administration. Primary splenic T cells manifested TNF-α-induced DNA damage in the absence of other cell types. Furthermore, TNFR1−/−TNFR2−/− mice demonstrated decreased systemic DNA damage in a model of intestinal inflammation and after TNF-α injection versus wild-type mice, indicating the necessity of TNFR signalling. Nuclear factor (NF)-κB inhibitors were also able to decrease damage induced by TNF-α injection in wild-type mice. When TNF-α administration was combined with interleukin (IL)-1β, another proinflammatory cytokine, DNA damage persisted for up to 24 h. When combined with IL-10, an anti-inflammatory cytokine, decreased genotoxicity was observed in vivo and in vitro. TNF-α/TNFR-mediated signalling is therefore sufficient and plays a large role in mediating DNA damage to various cell types, subject to modulation by other cytokines and their mediators. PMID:21980144

The influence of chronic stress on anxiety-like behavior and cognitive function in different human GFAP-ApoE transgenic adult male mice.

PubMed

Meng, Fan-Tao; Zhao, Jun; Fang, Hui; Liu, Ya-Jing

2015-01-01

The apolipoprotein E (ApoE) ɛ4 allele (ApoE4) is an important genetic risk factor for the pathogenesis of Alzheimer's disease (AD). In addition to genetic factors, environmental factors such as stress may play a critical role in AD pathogenesis. This study was designed to investigate the anxiety-like behavioral and cognitive changes in different human glial fibrillary acidic protein (GFAP)-ApoE transgenic adult male mice under chronic stress conditions. On the open field test, anxiety-like behavior was increased in the non-stressed GFAP-ApoE4 transgenic mice relative to the corresponding GFAP-ApoE3 (ApoE ɛ3 allele) mice. Anxiety-like behavior was increased in the stressed GFAP-ApoE3 mice relative to non-stressed GFAP-ApoE3 mice, but was unexpectedly decreased in the stressed GFAP-ApoE4 mice relative to non-stressed GFAP-ApoE4 mice. On the novel object recognition task, both GFAP-ApoE4 and GFAP-ApoE3 mice exhibited long-term non-spatial memory impairment after chronic stress. Interestingly, short-term non-spatial memory impairment (based on the novel object recognition task) was observed only in the stressed GFAP-ApoE4 male mice relative to non-stressed GFAP-ApoE4 transgenic mice. In addition, short-term spatial memory impairment was observed in the stressed GFAP-ApoE3 transgenic male mice relative to non-stressed GFAP-ApoE3 transgenic male mice; however, short-term spatial memory performance of GFAP-ApoE4 transgenic male mice was not reduced compared to non-stressed control mice based on the Y-maze task. In conclusion, our findings suggested that chronic stress affects anxiety-like behavior and spatial and non-spatial memory in GFAP-ApoE transgenic mice in an ApoE isoform-dependent manner.

The effects of chronic exposure to common bedding materials on the metabolic rate and overall health of male CD-1 mice.

PubMed

Becker, Corey E; Mathur, Carolyn F; Rehnberg, Bradley G

2010-01-01

Anecdotes and personal Web pages claim that cedar and pine beddings cause respiratory distress in rodents, although no previous research could be found to support these claims. There have, however, been published studies of respiratory distress in cedar and pine mill workers. That research links exposure to wood dust to asthma and to bronchial and alveolar damage in humans. This study looks at the effects of 3 types of bedding (CareFRESH Original, cedar, and pine) on the growth, food intake, oxygen consumption, IgE antibody concentrations, and general appearance and behavior in male CD-1 mice. Mice who were housed on these beddings for approximately 4 months did not show significant differences in any of these variables. This suggests that these 3 materials provide equally healthy substrates for long-term rearing of mice and possibly other rodents.

CCL2 and CCL3 are essential mediators of pelvic pain in experimental autoimmune prostatitis

PubMed Central

Quick, Marsha L.; Mukherjee, Soumi; Rudick, Charles N.; Done, Joseph D.; Schaeffer, Anthony J.

2012-01-01

Experimental autoimmune prostatitis (EAP) is a murine model of chronic prostatitis/chronic pelvic pain syndrome (CPPS) in men, a syndrome characterized by chronic pelvic pain. We have demonstrated that chemokine ligands CCL2 and CCL3 are biomarkers that correlate with pelvic pain symptoms. We postulated that CCL2 and CCL3 play a functional role in CPPS and therefore examined their expression in EAP. Upon examination of the prostate 5 days after induction of EAP, CCL2 mRNA was elevated 2- to 3-fold, CCL8 by 15-fold, CCL12 by 12- to 13-fold, and CXCL9 by 2- to 4-fold compared with control mice. At 10 days the major chemokines were CXCL13 and CXCL2; at 20 days CCL2 (1- to 2-fold), CCL3 (2- to 3-fold) and CCL11 (2- to 3-fold); and at 30 days, CCL12 (20- to 35-fold) and smaller increases in CCL2, CCL3, and XCL1. Chemokine elevations were accompanied by increases in mast cells and B cells at 5 days, monocytes and neutrophils at day 10, CD4+ T cells at day 20, and CD4+ and CD8+ T cells at day 30. Anti-CCL2 and anti-CCL3 neutralizing antibodies administered at EAP onset attenuated pelvic pain development, but only anti-CCL2 antibodies were effective therapeutically. CCL2- and its cognate receptor CCR2-deficient mice were completely protected from development of pain symptoms but assumed susceptibility after reconstitution with wild-type bone marrow. CCL3-deficient mice showed resistance to the maintenance of pelvic pain while CCR5-deficient mice did not show any lessening of pelvic pain severity. These results suggest that the CCL2-CCR2 axis and CCL3 are important mediators of chronic pelvic pain in EAP. PMID:22814670

Chronic wasting disease and atypical forms of BSE and scrapie are not transmissible to mice expressing wild-type levels of human PrP

USDA-ARS?s Scientific Manuscript database

The association between bovine spongiform encephalopathy (BSE) and variant Creutzfeldt-Jakob disease (vCJD) has demonstrated that cattle TSEs can pose a risk to human health and raises the possibility that other ruminant TSEs may be transmissible to humans. In recent years, several new TSEs in shee...

Extracellular cathepsin K exerts antimicrobial activity and is protective against chronic intestinal inflammation in mice.

PubMed

Sina, Christian; Lipinski, Simone; Gavrilova, Olga; Aden, Konrad; Rehman, Ateequr; Till, Andreas; Rittger, Andrea; Podschun, Rainer; Meyer-Hoffert, Ulf; Haesler, Robert; Midtling, Emilie; Pütsep, Katrin; McGuckin, Michael A; Schreiber, Stefan; Saftig, Paul; Rosenstiel, Philip

2013-04-01

Cathepsin K is a lysosomal cysteine protease that has pleiotropic roles in bone resorption, arthritis, atherosclerosis, blood pressure regulation, obesity and cancer. Recently, it was demonstrated that cathepsin K-deficient (Ctsk(-/-) ) mice are less susceptible to experimental autoimmune arthritis and encephalomyelitis, which implies a functional role for cathepsin K in chronic inflammatory responses. Here, the authors address the relevance of cathepsin K in the intestinal immune response during chronic intestinal inflammation. Chronic colitis was induced by administration of 2% dextran sodium sulphate (DSS) in distilled water. Mice were assessed for disease severity, histopathology and endoscopic appearance. Furthermore, DSS-exposed Ctsk(-/-) mice were treated by rectal administration of recombinant cathepsin K. Intestinal microflora was assessed by real-time PCR and 16srDNA molecular fingerprinting of ileal and colonic mucosal and faecal samples. Using Ctsk(-/-) mice, the authors demonstrate a protective role of cathepsin K against chronic DSS colitis. Dissecting the underlying mechanisms the authors found cathepsin K to be present in intestinal goblet cells and the mucin layer. Furthermore, a direct cathepsin K-mediated bactericidal activity against intestinal bacteria was demonstrated, which potentially explains the alteration of intestinal microbiota observed in Ctsk(-/-) mice. Rectal administration of recombinant cathepsin K in DSS-treated Ctsk(-/-) mice ameliorates the severity of intestinal inflammation. These data identify extracellular cathepsin K as an intestinal antibacterial factor with anti-inflammatory potential and suggest that topical administration of cathepsin K might provide a therapeutic option for patients with inflammatory bowel disease.

Sensorimotor control of breathing in the mdx mouse model of Duchenne muscular dystrophy.

PubMed

Burns, David P; Roy, Arijit; Lucking, Eric F; McDonald, Fiona B; Gray, Sam; Wilson, Richard J; Edge, Deirdre; O'Halloran, Ken D

2017-11-01

Respiratory failure is a leading cause of mortality in Duchenne muscular dystrophy (DMD), but little is known about the control of breathing in DMD and animal models. We show that young (8 weeks of age) mdx mice hypoventilate during basal breathing due to reduced tidal volume. Basal CO 2 production is equivalent in wild-type and mdx mice. We show that carotid bodies from mdx mice have blunted responses to hyperoxia, revealing hypoactivity in normoxia. However, carotid body, ventilatory and metabolic responses to hypoxia are equivalent in wild-type and mdx mice. Our study revealed profound muscle weakness and muscle fibre remodelling in young mdx diaphragm, suggesting severe mechanical disadvantage in mdx mice at an early age. Our novel finding of potentiated neural motor drive to breathe in mdx mice during maximal chemoactivation suggests compensatory neuroplasticity enhancing respiratory motor output to the diaphragm and probably other accessory muscles. Patients with Duchenne muscular dystrophy (DMD) hypoventilate with consequential arterial blood gas derangement relevant to disease progression. Whereas deficits in DMD diaphragm are recognized, there is a paucity of knowledge in respect of the neural control of breathing in dystrophinopathies. We sought to perform an analysis of respiratory control in a model of DMD, the mdx mouse. In 8-week-old male wild-type and mdx mice, ventilation and metabolism, carotid body afferent activity, diaphragm muscle force-generating capacity, and muscle fibre size, distribution and centronucleation were determined. Diaphragm EMG activity and responsiveness to chemostimulation was determined. During normoxia, mdx mice hypoventilated, owing to a reduction in tidal volume. Basal CO 2 production was not different between wild-type and mdx mice. Carotid sinus nerve responses to hyperoxia were blunted in mdx, suggesting hypoactivity. However, carotid body, ventilatory and metabolic responses to hypoxia were equivalent in wild-type and mdx mice. Diaphragm force was severely depressed in mdx mice, with evidence of fibre remodelling and damage. Diaphragm EMG responses to chemoactivation were enhanced in mdx mice. We conclude that there is evidence of chronic hypoventilation in young mdx mice. Diaphragm dysfunction confers mechanical deficiency in mdx resulting in impaired capacity to generate normal tidal volume at rest and decreased absolute ventilation during chemoactivation. Enhanced mdx diaphragm EMG responsiveness suggests compensatory neuroplasticity facilitating respiratory motor output, which may extend to accessory muscles of breathing. Our results may have relevance to emerging treatments for human DMD aiming to preserve ventilatory capacity. © 2017 The Authors. The Journal of Physiology © 2017 The Physiological Society.

Protective effect of genetic deletion of pannexin1 in experimental mouse models of acute and chronic liver disease.

PubMed

Willebrords, Joost; Maes, Michaël; Pereira, Isabel Veloso Alves; da Silva, Tereza Cristina; Govoni, Veronica Mollica; Lopes, Valéria Veras; Crespo Yanguas, Sara; Shestopalov, Valery I; Nogueira, Marina Sayuri; de Castro, Inar Alves; Farhood, Anwar; Mannaerts, Inge; van Grunsven, Leo; Akakpo, Jephte; Lebofsky, Margitta; Jaeschke, Hartmut; Cogliati, Bruno; Vinken, Mathieu

2018-03-01

Pannexins are transmembrane proteins that form communication channels connecting the cytosol of an individual cell with its extracellular environment. A number of studies have documented the presence of pannexin1 in liver as well as its involvement in inflammatory responses. In this study, it was investigated whether pannexin1 plays a role in acute liver failure and non-alcoholic steatohepatitis, being prototypical acute and chronic liver pathologies, respectively, both featured by liver damage, oxidative stress and inflammation. To this end, wild-type and pannexin1 -/- mice were overdosed with acetaminophen for 1, 6, 24 or 48h or were fed a choline-deficient high-fat diet for 8weeks. Evaluation of the effects of genetic pannexin1 deletion was based on a number of clinically relevant read-outs, including markers of liver damage, histopathological analysis, lipid accumulation, protein adduct formation, oxidative stress and inflammation. In parallel, in order to elucidate molecular pathways affected by pannexin1 deletion as well as to mechanistically anchor the clinical observations, whole transcriptome analysis of liver tissue was performed. The results of this study show that pannexin1 -/- diseased mice present less liver damage and oxidative stress, while inflammation was only decreased in pannexin1 -/- mice in which non-alcoholic steatohepatitis was induced. A multitude of genes related to inflammation, oxidative stress and xenobiotic metabolism were differentially modulated in both liver disease models in wild-type and in pannexin1 -/- mice. Overall, the results of this study suggest that pannexin1 may play a role in the pathogenesis of liver disease. Copyright © 2017 Elsevier B.V. All rights reserved.

Vaccination with a DNA vaccine encoding Toxoplasma gondii ROP54 induces protective immunity against toxoplasmosis in mice.

PubMed

Yang, Wen-Bin; Zhou, Dong-Hui; Zou, Yang; Chen, Kai; Liu, Qing; Wang, Jin-Lei; Zhu, Xing-Quan; Zhao, Guang-Hui

2017-12-01

Toxoplasma gondii is an obligatory intracellular protozoan, which infects most of the warm-blooded animals, causing serious public health problems and enormous economic losses worldwide. The rhoptry effector protein 54 (ROP54) has been indicated as a virulence factor that promotes Toxoplasma infection by modulating GBP2 loading onto parasite-containing vacuoles, which can modulate some aspects of the host immune response. In order to evaluate the immuno-protective value of ROP54, we constructed a eukaryotic recombinant plasmid expressing T. gondii ROP54 and intramuscularly immunized Kunming mice with this recombinant plasmid against acute and chronic toxoplasmosis. All mice immunized with pVAX-ROP54 elicited a high level of specific antibody responses, a significant increase of lymphocyte proliferation, and a significant level of Th1-type cytokines (IFN-γ, IL-2 and IL-12p70), in addition to an increased production of Th2-type cytokines (IL-4 and IL-10). These results demonstrated that pVAX-ROP54 induced significant cellular and humoral (Th1/Th2) immune responses, which extended the survival time (13.0±1.15days for pVAX-ROP54 vs 6.7±0.48days for pVAX I, 6.8±0.42days for PBS and 6.5±0.53 for blank control) and significantly reduced cyst burden (35.9% for pVAX-ROP54, 1% for pVAX I and 2% for PBS, compared with blank control) of immunized mice. These results indicate that the recombinant ROP54 plasmid can provide partial protection and might be a potential vaccine candidate against acute and chronic toxoplasmosis. Copyright © 2017 Elsevier B.V. All rights reserved.

Pioglitazone restores phagocyte mitochondrial oxidants and bactericidal capacity in Chronic Granulomatous Disease

PubMed Central

Fernandez-Boyanapalli, Ruby F.; Frasch, S. Courtney; Thomas, Stacey M.; Malcolm, Kenneth C.; Nicks, Michael; Harbeck, Ronald J.; Jakubzick, Claudia V.; Nemenoff, Raphael; Henson, Peter M.; Holland, Steven M.; Bratton, Donna L.

2015-01-01

Background Deficient production of reactive oxygen species (ROS) by the phagocyte NADPH oxidase in Chronic Granulomatous Disease (CGD) results in susceptibility to certain pathogens secondary to impaired oxidative killing and mobilization of other phagocyte defenses. PPARγ agonists including pioglitazone (Pio), approved for Type 2 diabetes therapy, alter cellular metabolism and can heighten ROS production. It was hypothesized that Pio treatment of gp91phox−/− mice, a murine model of human CGD, would enhance phagocyte oxidant production and killing of S. aureus, a significant pathogen in this disorder. Objectives We sought to determine if Pio treatment of gp91phox−/− mice enhanced phagocyte oxidant production and host defense. Methods Wild type (WT) and gp91phox−/− mice were treated with the PPARγ agonist Pio, and phagocyte ROS and killing of S. aureus investigated. Results As demonstrated by three different ROS sensing probes, short-term treatment of gp91phox−/− mice with Pio enhanced stimulated ROS production in neutrophils and monocytes from blood and neutrophils and inflammatory macrophages recruited to tissues. Mitochondria were identified as the source of ROS (mtROS). Findings were replicated in human CGD monocytes following ex vivo Pio treatment. Importantly, while mtROS were deficient in gp91phox−/− phagocytes, their restoration with treatment significantly enabled killing of S. aureus both ex vivo and in vivo. Conclusions Together, the data support the hypothesis that signaling from the NADPH oxidase under normal circumstances governs phagocyte mtROS production, and that such signaling is lacking in the absence of a functioning phagocyte oxidase. PPARγ agonism appears to bypass the need for the NADPH oxidase for enhanced mtROS production and partially restores host defense in CGD. PMID:25498313

Behavioral effects of chronic fluoxetine in BALB/cJ mice do not require adult hippocampal neurogenesis or the serotonin 1A receptor.

PubMed

Holick, Kerri A; Lee, Daniel C; Hen, René; Dulawa, Stephanie C

2008-01-01

We previously reported that chronic, but not subchronic, treatment with the selective serotonin reuptake inhibitor (SSRI) fluoxetine altered behavior in the forced swimming test (FST) in BALB/cJ mice. We now use this model to investigate mechanisms underlying the delayed onset of the behavioral response to antidepressants, specifically (1) adult hippocampal neurogenesis and (2) expression of the 5-HT1A receptor. Here, we show data validating this model of chronic antidepressant action. We found the FST to be selectively responsive to chronic administration of the SSRI fluoxetine (18 mg/kg/day) and the tricyclic antidepressant desipramine (20 mg/kg/day), but not to the antipsychotic haloperidol (1 mg/kg/day) in BALB/cJ mice. The behavioral effects of fluoxetine emerged by 12 days of treatment, and were affected neither by ablation of progenitor cells of the hippocampus nor by genetic deletion of the 5-HT1A receptor. The effect of fluoxetine in the BALB/cJ mice was also neurogenesis-independent in the novelty-induced hypophagia test. We also found that chronic fluoxetine does not induce an increase in cell proliferation or the number of young neurons as measured by BrdU and doublecortin immunolabeling, respectively, in BALB/cJ mice. These data are in contrast to our previous report using a different strain of mice (129SvEvTac). In conclusion, we find that BALB/cJ mice show a robust response to chronic SSRI treatment in the FST, which is not mediated by an increase in new neurons in the hippocampus, and does not require the 5-HT1A receptor. These findings suggest that SSRIs can produce antidepressant-like effects via distinct mechanisms in different mouse strains.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Leem, Yea-Hyun, E-mail: leemyy@empas.com; Lee, Young-Ik, E-mail: lee0ik@hanmail.net; Son, Hee-Jeong, E-mail: son1106@paran.com

Research highlights: {yields} The progress of neurodegeration are directly linked to the neuroinflammatory response. {yields} We investigate whether exercise improves the neuroinflammation using T{sub g}-NSE/htau23 mice. {yields} This provides insights that exercise may beneficial effects on the neuroinflammatory disorders. -- Abstract: The objective of the present study was to investigate whether chronic endurance exercise attenuates the neuroinflammation in the brain of mice with NSE/htau23. In this study, the tau-transgenic (Tg) mouse, Tg-NSE/htau23, which over expresses human Tau23 in its brain, was subjected to chronic exercise for 3 months, from 16 months of age. The brains of Tg mice exhibited increasedmore » immunoreactivity and active morphological changes in GFAP (astrocyte marker) and MAC-1 (microglia marker) expression in an age-dependent manner. To identify the effects of chronic exercise on gliosis, the exercised Tg mice groups were treadmill run at a speed of 12 m/min (intermediate exercise group) or 19 m/min (high exercise group) for 1 h/day and 5 days/week during the 3 month period. The neuroinflammatory response characterized by activated astroglia and microglia was significantly repressed in the exercised Tg mice in an exercise intensity-dependent manner. In parallel, chronic exercise in Tg mice reduced the increased expression of TNF-{alpha}, IL-6, IL-1{beta}, COX-2, and iNOS. Consistently with these changes, the levels of phospho-p38 and phospho-ERK were markedly downregulated in the brain of Tg mice after exercise. In addition, nuclear NF-{kappa}B activity was profoundly reduced after chronic exercise in an exercise intensity-dependent manner. These findings suggest that chronic endurance exercise may alleviate neuroinflammation in the Tau pathology of Alzheimer's disease.« less

A role for calmodulin-stimulated adenylyl cyclases in cocaine sensitization.

PubMed

DiRocco, Derek P; Scheiner, Zachary S; Sindreu, Carlos Balet; Chan, Guy C-K; Storm, Daniel R

2009-02-25

Cocaine sensitization is produced by repeated exposure to the drug and is thought to reflect neuroadaptations that contribute to addiction. Here, we identify the Ca(2+)/calmodulin-stimulated adenylyl cyclases, type 1 (AC1) and type 8 (AC8), as novel regulators of this behavioral plasticity. We show that, whereas AC1 and AC8 single knock-out mice (AC1(-/-) and AC8(-/-)) exhibit Ca(2+)-stimulated adenylyl cyclase activity in striatal membrane fractions, AC1/8 double-knock-out (DKO) mice do not. Furthermore, DKO mice are acutely supersensitive to low doses of cocaine and fail to display locomotor sensitization after chronic cocaine treatment. Because of the known role for the extracellular signal-regulated kinase (ERK)/mitogen-activated protein kinase signaling pathway in cocaine-induced behavioral plasticity and its coupling to calcium-stimulated cAMP signaling in the hippocampus, we measured phosphorylated ERK (pERK) levels in the striatum. Under basal conditions, pERK is upregulated in choline acetyltransferase-positive interneurons in DKO mice relative to wild-type (WT) controls. After acute cocaine treatment, pERK signaling is significantly suppressed in medium spiny neurons (MSNs) of DKO mice relative to WT mice. In addition to the lack of striatal ERK activation by acute cocaine, signaling machinery downstream of ERK is uncoupled in DKO mice. We demonstrate that AC1 and AC8 are necessary for the phosphorylation of mitogen and stress-activated kinase-1 (pMSK1) at Ser376 and Thr581 and cAMP response element-binding protein (pCREB) at Ser133 after acute cocaine treatment. Our results demonstrate that the Ca(2+)-stimulated adenylyl cyclases regulate long-lasting cocaine-induced behavioral plasticity via activation of the ERK/MSK1/CREB signaling pathway in striatonigral MSNs.

A Role for Calmodulin-Stimulated Adenylyl Cyclases in Cocaine Sensitization

PubMed Central

DiRocco, Derek P.; Scheiner, Zachary S.; Sindreu, Carlos Balet; Chan, Guy C-K; Storm, Daniel R.

2009-01-01

Cocaine sensitization is produced by repeated exposure to the drug and is thought to reflect neuroadaptations that contribute to addiction. Here, we identify the Ca2+/calmodulin-stimulated adenylyl cyclases, type 1 (AC1) and type 8 (AC8), as novel regulators of this behavioral plasticity. We show that while AC1 and AC8 single knockout mice (AC1−/− and AC8−/−) exhibit Ca2+-stimulated adenylyl cyclase activity in striatal membrane fractions, AC1/8 double-knockout (DKO) mice do not. Furthermore, DKO mice are acutely supersensitive to low doses of cocaine and fail to display locomotor sensitization following chronic cocaine treatment. Because of the known role for the ERK/MAP kinase signaling pathway in cocaine-induced behavioral plasticity and its coupling to calcium-stimulated cAMP signaling in the hippocampus, we measured phosphorylated extracellular signal-regulated kinase (pERK) levels in the striatum. Under basal conditions, pERK is upregulated in choline acetyltransferase positive (ChAT+) interneurons in DKO mice relative to wild-type (WT) controls. Following acute cocaine treatment, pERK signaling is significantly suppressed in medium spiny neurons (MSNs) of DKO mice relative to WT mice. In addition to the lack of striatal ERK activation by acute cocaine, signaling machinery downstream of ERK is uncoupled in DKO mice. We demonstrate that AC1 and AC8 are necessary for the phosphorylation of mitogen and stress-activated kinase-1 (pMSK1) at Ser376 and Thr581, and cAMP response element-binding protein (pCREB) at Ser133 following acute cocaine treatment. Our results demonstrate that the Ca2+-stimulated adenylyl cyclases regulate long-lasting cocaine-induced behavioral plasticity via activation of the ERK/MSK1/CREB signaling pathway in striatonigral MSNs. PMID:19244515

Mitochondrial Aldehyde Dehydrogenase 2 Regulates Revascularization in Chronic Ischemia: Potential Impact on the Development of Coronary Collateral Circulation.

PubMed

Liu, Xiangwei; Sun, Xiaolei; Liao, Hua; Dong, Zhen; Zhao, Jingjing; Zhu, Hong; Wang, Peng; Shen, Li; Xu, Lei; Ma, Xin; Shen, Cheng; Fan, Fan; Wang, Cong; Hu, Kai; Zou, Yunzeng; Ge, Junbo; Ren, Jun; Sun, Aijun

2015-10-01

Revascularization is an essential process to compensate for cardiac underperfusion and, therefore, preserves cardiac function in the face of chronic ischemic injury. Recent evidence suggested a vital role of aldehyde dehydrogenase 2 (ALDH2) in cardiac protection after ischemia. This study was designed to determine whether ALDH2 regulates chronic ischemia-induced angiogenesis and to explore the underlying mechanism involved. Moreover, the clinical impact of the ALDH2 mutant allele on the development of coronary collateral circulation (CCC) was evaluated. Mice limb ischemia was performed. Compared with wild-type, ALDH2 deletion significantly reduced perfusion recovery, small artery and capillary density, and increased muscle atrophy in this ischemic model. In vitro, ALDH2-knockdown reduced proliferation, migration and hypoxia triggered endothelial tube formation of endothelial cells, the effects of which were restored by ALDH2 transfection. Further examination revealed that ALDH2 regulated angiogenesis possibly through hypoxia-inducible factor-1α/vascular endothelial growth factor pathways. To further discern the role of ALDH2 deficiency in the function of bone marrow stem/progenitor cells, cross bone marrow transplantation was performed between wild-type and ALDH2-knockout mice. However, there was no significant improvement for wild-type bone marrow transplantation into knockout mice. ALDH2 genotyping was screened in 139 patients with chronic total occlusion recruited to Zhongshan Hospital (2011.10-2014.4). Patients with poor CCC (Rentrop 0-1; n=51) exhibited a higher frequency of the AA genotype than those with enriched CCC (Rentrop 2-3; n=88; 11.76% versus 1.14%; P=0 0.01). However, the AA group displayed less enriched CCC frequency in Logistic regression model when compared with the GG group (odds ratio=0.08; 95% confidence interval, 0.009-0.701; P=0 0.026). Furthermore, serum vascular endothelial growth factor level tended to be lower in patients with ALDH2 mutation. This study demonstrated that ALDH2 possesses an intrinsic capacity to regulate angiogenesis via hypoxia-inducible factor-1α and vascular endothelial growth factor. Patients with ALDH2-deficient genotype displayed a higher risk of developing poor CCC. Therapeutic individualization based on ALDH2 allele distribution may thus improve the therapeutic benefit, especially in the East Asian decedents. © 2015 American Heart Association, Inc.

Reversal of disease-related pathologies in the fragile X mouse model by selective activation of GABAB receptors with arbaclofen.

PubMed

Henderson, Christina; Wijetunge, Lasani; Kinoshita, Mika Nakamoto; Shumway, Matthew; Hammond, Rebecca S; Postma, Friso R; Brynczka, Christopher; Rush, Roger; Thomas, Alexia; Paylor, Richard; Warren, Stephen T; Vanderklish, Peter W; Kind, Peter C; Carpenter, Randall L; Bear, Mark F; Healy, Aileen M

2012-09-19

Fragile X syndrome (FXS), the most common inherited cause of intellectual disability and autism, results from the transcriptional silencing of FMR1 and loss of the mRNA translational repressor protein fragile X mental retardation protein (FMRP). Patients with FXS exhibit changes in neuronal dendritic spine morphology, a pathology associated with altered synaptic function. Studies in the mouse model of fragile X have shown that loss of FMRP causes excessive synaptic protein synthesis, which results in synaptic dysfunction and altered spine morphology. We tested whether the pharmacologic activation of the γ-aminobutyric acid type B (GABA(B)) receptor could correct or reverse these phenotypes in Fmr1-knockout mice. Basal protein synthesis, which is elevated in the hippocampus of Fmr1-knockout mice, was corrected by the in vitro application of the selective GABA(B) receptor agonist STX209 (arbaclofen, R-baclofen). STX209 also reduced to wild-type values the elevated AMPA receptor internalization in Fmr1-knockout cultured neurons, a known functional consequence of increased protein synthesis. Acute administration of STX209 in vivo, at doses that modify behavior, decreased mRNA translation in the cortex of Fmr1-knockout mice. Finally, the chronic administration of STX209 in juvenile mice corrected the increased spine density in Fmr1-knockout mice without affecting spine density in wild-type mice. Thus, activation of the GABA(B) receptor with STX209 corrected synaptic abnormalities considered central to fragile X pathophysiology, a finding that suggests that STX209 may be a potentially effective therapy to treat the core symptoms of FXS.

Augmentation of the expression of the eotaxin receptor on duodenal neutrophils by IL-21.

PubMed

Takeda, Yuji; Kato, Tomoyuki; Nemoto, Nobuhito; Araki, Akemi; Gazi, Mohammad Yeashin; Nara, Hidetoshi; Asao, Hironobu

2018-05-16

Inflammation can occur via different mechanisms, such as via acute and chronic responses, on numerous occasions and function accordingly through various roles. There are more than five subsets of neutrophils; neutrophilic heterogeneity is modulated by the inflammatory condition. To understand the characteristics of inflammation, identification of atypical neutrophils is important. In this study, we found that the expression of eotaxin receptor (CD193) on atypical neutrophils in the duodenum is augmented in IL-21 isoform transgenic (Tg) mice. In a series of studies, we have established a Tg mouse strain to further investigate the functions of IL-21 in vivo. Interestingly, Tg mice immunized with ovalbumin (OVA) were more sensitive to OVA-induced systemic anaphylaxis as compared with wild type mice with duodenal and splenic gross congestion. Further analysis conducted in the duodenum of Tg mice revealed that only the number of neutrophils migrating into the duodenum was significantly increased prior to immunization. Previous studies have shown that the gastrointestinal compartment and the spleen constantly produce eotaxin, which regulates basal levels of tissue eosinophils. Therefore, we analyzed CD193 expression on neutrophils and eosinophils. As expected, its expression by duodenal neutrophils was upregulated in Tg mice. Furthermore, the addition of IL-21 into bone marrow cell culture increased the number of CD193 + neutrophils, which easily migrated into the duodenum. These observations suggested that CD193 + neutrophils increase in number under inflammatory conditions due to chronic IL-21 production. Copyright © 2018 Elsevier Ltd. All rights reserved.

Nociceptor Sensitization Depends on Age and Pain Chronicity123

PubMed Central

Dodge, Amanda K.

2016-01-01

Abstract Peripheral inflammation causes mechanical pain behavior and increased action potential firing. However, most studies examine inflammatory pain at acute, rather than chronic time points, despite the greater burden of chronic pain on patient populations, especially aged individuals. Furthermore, there is disagreement in the field about whether primary afferents contribute to chronic pain. Therefore, we sought to evaluate the contribution of nociceptor activity to the generation of pain behaviors during the acute and chronic phases of inflammation in both young and aged mice. We found that both young (2 months old) and aged (>18 months old) mice exhibited prominent pain behaviors during both acute (2 day) and chronic (8 week) inflammation. However, young mice exhibited greater behavioral sensitization to mechanical stimuli than their aged counterparts. Teased fiber recordings in young animals revealed a twofold mechanical sensitization in C fibers during acute inflammation, but an unexpected twofold reduction in firing during chronic inflammation. Responsiveness to capsaicin and mechanical responsiveness of A-mechanonociceptor (AM) fibers were also reduced chronically. Importantly, this lack of sensitization in afferent firing during chronic inflammation occurred even as these inflamed mice exhibited continued behavioral sensitization. Interestingly, C fibers from inflamed aged animals showed no change in mechanical firing compared with controls during either the acute or chronic inflammatory phases, despite strong behavioral sensitization to mechanical stimuli at these time points. These results reveal the following two important findings: (1) nociceptor sensitization to mechanical stimulation depends on age and the chronicity of injury; and (2) maintenance of chronic inflammatory pain does not rely on enhanced peripheral drive. PMID:26866058

Impaired fear extinction learning in adult heterozygous BDNF knock-out mice.

PubMed

Psotta, Laura; Lessmann, Volkmar; Endres, Thomas

2013-07-01

Brain-derived neurotrophic factor (BDNF) is a crucial regulator of neuroplasticity, which underlies learning and memory processes in different brain areas. To investigate the role of BDNF in the extinction of amygdala-dependent cued fear memories, we analyzed fear extinction learning in heterozygous BDNF knock-out mice, which possess a reduction of endogenous BDNF protein levels to ~50% of wild-type animals. Since BDNF expression has been shown to decline with aging of animals, we tested the performance in extinction learning of these mice at 2 months (young adults) and 7 months (older adults) of age. The present study shows that older adult heterozygous BDNF knock-out mice, which have a chronic 50% lack of BDNF, also possess a deficit in the acquisition of extinction memory, while extinction learning remains unaffected in young adult heterozygous BDNF knock-out mice. This deficit in extinction learning is accompanied by a reduction of BDNF protein in the hippocampus, amygdala and the prefrontal cortex. Copyright © 2013 Elsevier Inc. All rights reserved.

Truncated recombinant human SP-D attenuates emphysema and type II cell changes in SP-D deficient mice

PubMed Central

Knudsen, Lars; Ochs, Matthias; MacKay, Rosemarie; Townsend, Paul; Deb, Roona; Mühlfeld, Christian; Richter, Joachim; Gilbert, Fabian; Hawgood, Samuel; Reid, Kenneth; Clark, Howard

2007-01-01

Background Surfactant protein D (SP-D) deficient mice develop emphysema-like pathology associated with focal accumulations of foamy alveolar macrophages, an excess of surfactant phospholipids in the alveolar space and both hypertrophy and hyperplasia of alveolar type II cells. These findings are associated with a chronic inflammatory state. Treatment of SP-D deficient mice with a truncated recombinant fragment of human SP-D (rfhSP-D) has been shown to decrease the lipidosis and alveolar macrophage accumulation as well as production of proinflammatory chemokines. The aim of this study was to investigate if rfhSP-D treatment reduces the structural abnormalities in parenchymal architecture and type II cells characteristic of SP-D deficiency. Methods SP-D knock-out mice, aged 3 weeks, 6 weeks and 9 weeks were treated with rfhSP-D for 9, 6 and 3 weeks, respectively. All mice were sacrificed at age 12 weeks and compared to both PBS treated SP-D deficient and wild-type groups. Lung structure was quantified by design-based stereology at the light and electron microscopic level. Emphasis was put on quantification of emphysema, type II cell changes and intracellular surfactant. Data were analysed with two sided non-parametric Mann-Whitney U-test. Main Results After 3 weeks of treatment, alveolar number was higher and mean alveolar size was smaller compared to saline-treated SP-D knock-out controls. There was no significant difference concerning these indices of pulmonary emphysema within rfhSP-D treated groups. Type II cell number and size were smaller as a consequence of treatment. The total volume of lamellar bodies per type II cell and per lung was smaller after 6 weeks of treatment. Conclusion Treatment of SP-D deficient mice with rfhSP-D leads to a reduction in the degree of emphysema and a correction of type II cell hyperplasia and hypertrophy. This supports the concept that rfhSP-D might become a therapeutic option in diseases that are characterized by decreased SP-D levels in the lung. PMID:17915009

Interleukin-17-induced protein lipocalin 2 is dispensable for immunity to oral candidiasis.

PubMed

Ferreira, Maria Carolina; Whibley, Natasha; Mamo, Anna J; Siebenlist, Ulrich; Chan, Yvonne R; Gaffen, Sarah L

2014-03-01

Oropharyngeal candidiasis (OPC; thrush) is an opportunistic fungal infection caused by the commensal microbe Candida albicans. Immunity to OPC is strongly dependent on CD4+ T cells, particularly those of the Th17 subset. Interleukin-17 (IL-17) deficiency in mice or humans leads to chronic mucocutaneous candidiasis, but the specific downstream mechanisms of IL-17-mediated host defense remain unclear. Lipocalin 2 (Lcn2; 24p3; neutrophil gelatinase-associated lipocalin [NGAL]) is an antimicrobial host defense factor produced in response to inflammatory cytokines, particularly IL-17. Lcn2 plays a key role in preventing iron acquisition by bacteria that use catecholate-type siderophores, and lipocalin 2(-/-) mice are highly susceptible to infection by Escherichia coli and Klebsiella pneumoniae. The role of Lcn2 in mediating immunity to fungi is poorly defined. Accordingly, in this study, we evaluated the role of Lcn2 in immunity to oral infection with C. albicans. Lcn2 is strongly upregulated following oral infection with C. albicans, and its expression is almost entirely abrogated in mice with defective IL-17 signaling (IL-17RA(-/-) or Act1(-/-) mice). However, Lcn2(-/-) mice were completely resistant to OPC, comparably to wild-type (WT) mice. Moreover, Lcn2 deficiency mediated protection from OPC induced by steroid immunosuppression. Therefore, despite its potent regulation during C. albicans infection, Lcn2 is not required for immunity to mucosal candidiasis.

B cell-deficient mice display enhanced susceptibility to Paracoccidioides brasiliensis Infection.

PubMed

Tristão, F S M; Panagio, L A; Rocha, F A; Cavassani, K A; Moreira, A P; Rossi, M A; Silva, J S

2013-08-01

Paracoccidioidomycosis (PCM) is a chronic granulomatous disease caused by the thermally dimorphic fungus Paracoccidioides brasiliensis. T helper 1 (Th1)-mediated immunity is primarily responsible for acquired resistance during P. brasiliensis infection. On the contrary, the susceptibility is associated with occurrence of type-2 immunity (Th2), which is characterized by IL-4 release, B cell activation, and production of antibodies. Although antibodies are frequently associated with severe PCM, it is not clear whether they contribute to susceptibility or merely constitute a marker of infection stage. Here, we assessed the function of B cells during experimental P. brasiliensis infection in mice, and our results showed that B cell-knockout (B(KO)) mice are more susceptible than their wild-type littermate controls (C57BL/6, WT). The B(KO) mice showed higher mortality rate, increased number of colony-forming units in the lungs, and larger granulomas than WT mice. In the absence of B cells, we observed high levels of IL-10, whereas IFN-γ, TNF-α, and IL-4 levels were similar between both groups. Finally, we showed that transference of WT immune serum to B(KO) mice resulted in diminished infiltration of inflammatory cells and better organization of the pulmonary granulomas. Taken together, these data suggest that B cells are effectively involved in the control of P. brasiliensis growth and organization of the granulomatous lesions observed during the experimental PCM.

Anemia in new congenital adult type polycystic kidney mice.

PubMed

Koumegawa, J; Nagano, N; Arai, H; Wada, M; Kusaka, M; Takahashi, H

1991-12-01

Mechanisms for the development of anemia and the effects of recombinant human erythropoietin (r-HuEPO) on hematological parameters were studied in new congenital adult type polycystic kidney (DBA/2FG-pcy) mice. The majority of DBA/2FG-pcy mice showed progressive anemia and an elevation of blood urea nitrogen, while a minority showed progressive anemia following polycythemia. Kidneys with numerous cysts in the cortex and medulla occupied virtually the entire abdominal cavity, and the combined kidney weight taken as a percentage of body weight reached 13.5% in the DBA/2FG-pcy mouse. The osmotic fragility of DBA/2FG-pcy mice erythrocytes was significantly increased compared with that of normal control mice. In addition, two-fold increases in serum EPO levels, determined by radioimmunoassay, and a decreased number of colony forming unit-erythroid (CFU-E) were observed in the DBA/2FG-pcy mice. The administration of r-HuEPO during anemia significantly increased the red blood cell count, hemoglobin concentration, hematocrit and reticulocyte percentage in a dose-dependent manner. These findings indicate that anemia in the DBA/2FG-pcy mouse is due to increased fragility of erythrocytes, a deficiency in EPO for the degree of anemia and a decreased number or a decreased response of erythroid progenitor cells. We suggest that the DBA/2FG-pcy mouse is a useful spontaneous model of chronic progressive renal failure.

Amelioration of Metabolic Syndrome-Associated Cognitive Impairments in Mice via a Reduction in Dietary Fat Content or Infusion of Non-Diabetic Plasma

PubMed Central

Johnson, Lance A.; Zuloaga, Kristen L.; Kugelman, Tara L.; Mader, Kevin S.; Morré, Jeff T.; Zuloaga, Damian G.; Weber, Sydney; Marzulla, Tessa; Mulford, Amelia; Button, Dana; Lindner, Jonathan R.; Alkayed, Nabil J.; Stevens, Jan F.; Raber, Jacob

2015-01-01

Obesity, metabolic syndrome (MetS) and type 2 diabetes (T2D) are associated with decreased cognitive function. While weight loss and T2D remission result in improvements in metabolism and vascular function, it is less clear if these benefits extend to cognitive performance. Here, we highlight the malleable nature of MetS-associated cognitive dysfunction using a mouse model of high fat diet (HFD)-induced MetS. While learning and memory was generally unaffected in mice with type 1 diabetes (T1D), multiple cognitive impairments were associated with MetS, including deficits in novel object recognition, cued fear memory, and spatial learning and memory. However, a brief reduction in dietary fat content in chronic HFD-fed mice led to a complete rescue of cognitive function. Cerebral blood volume (CBV), a measure of vascular perfusion, was decreased during MetS, was associated with long term memory, and recovered following the intervention. Finally, repeated infusion of plasma collected from age-matched, low fat diet-fed mice improved memory in HFD mice, and was associated with a distinct metabolic profile. Thus, the cognitive dysfunction accompanying MetS appears to be amenable to treatment, related to cerebrovascular function, and mitigated by systemic factors. PMID:26870815

Ghrelin increases the rewarding value of high-fat diet in an orexin-dependent manner.

PubMed

Perello, Mario; Sakata, Ichiro; Birnbaum, Shari; Chuang, Jen-Chieh; Osborne-Lawrence, Sherri; Rovinsky, Sherry A; Woloszyn, Jakub; Yanagisawa, Masashi; Lutter, Michael; Zigman, Jeffrey M

2010-05-01

Ghrelin is a potent orexigenic hormone that likely impacts eating via several mechanisms. Here, we hypothesized that ghrelin can regulate extra homeostatic, hedonic aspects of eating behavior. In the current study, we assessed the effects of different pharmacological, physiological, and genetic models of increased ghrelin and/or ghrelin-signaling blockade on two classic behavioral tests of reward behavior: conditioned place preference (CPP) and operant conditioning. Using both CPP and operant conditioning, we found that ghrelin enhanced the rewarding value of high-fat diet (HFD) when administered to ad lib-fed mice. Conversely, wild-type mice treated with ghrelin receptor antagonist and ghrelin receptor-null mice both failed to show CPP to HFD normally observed under calorie restriction. Interestingly, neither pharmacologic nor genetic blockade of ghrelin signaling inhibited the body weight homeostasis-related, compensatory hyperphagia associated with chronic calorie restriction. Also, ghrelin's effects on HFD reward were blocked in orexin-deficient mice and wild-type mice treated with an orexin 1 receptor antagonist. Our results demonstrate an obligatory role for ghrelin in certain rewarding aspects of eating that is separate from eating associated with body weight homeostasis and that requires the presence of intact orexin signaling. Copyright 2010 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.

Chronic exposure to low concentrations of lead induces metabolic disorder and dysbiosis of the gut microbiota in mice.

PubMed

Xia, Jizhou; Jin, Cuiyuan; Pan, Zihong; Sun, Liwei; Fu, Zhengwei; Jin, Yuanxiang

2018-08-01

Lead (Pb) is one of the most prevalent toxic, nonessential heavy metals that can contaminate food and water. In this study, effects of chronic exposure to low concentrations of Pb on metabolism and gut microbiota were evaluated in mice. It was observed that exposure of mice to 0.1mg/L Pb, supplied via drinking water, for 15weeks increased hepatic TG and TCH levels. The levels of some key genes related to lipid metabolism in the liver increased significantly in Pb-treated mice. For the gut microbiota, at the phylum level, the relative abundance of Firmicutes and Bacteroidetes changed obviously in the feces and the cecal contents of mice exposed to 0.1mg/L Pb for 15weeks. In addition, 16s rRNA gene sequencing further discovered that Pb exposure affected the structure and richness of the gut microbiota. Moreover, a 1 H NMR metabolic analysis unambiguously identified 31 metabolites, and 15 metabolites were noticeably altered in 0.1mg/L Pb-treated mice. Taken together, the data indicate that chronic Pb exposure induces dysbiosis of the gut microbiota and metabolic disorder in mice. Chronic Pb exposure induces metabolic disorder, dysbiosis of the gut microbiota and hepatic lipid metabolism disorder in mice. Copyright © 2018 Elsevier B.V. All rights reserved.

Exercise training in Tgαq*44 mice during the progression of chronic heart failure: cardiac vs. peripheral (soleus muscle) impairments to oxidative metabolism.

PubMed

Grassi, Bruno; Majerczak, Joanna; Bardi, Eleonora; Buso, Alessia; Comelli, Marina; Chlopicki, Stefan; Guzik, Magdalena; Mavelli, Irene; Nieckarz, Zenon; Salvadego, Desy; Tyrankiewicz, Urszula; Skórka, Tomasz; Bottinelli, Roberto; Zoladz, Jerzy A; Pellegrino, Maria Antonietta

2017-08-01

Cardiac function, skeletal (soleus) muscle oxidative metabolism, and the effects of exercise training were evaluated in a transgenic murine model (Tgα q *44) of chronic heart failure during the critical period between the occurrence of an impairment of cardiac function and the stage at which overt cardiac failure ensues (i.e., from 10 to 12 mo of age). Forty-eight Tgα q *44 mice and 43 wild-type FVB controls were randomly assigned to control groups and to groups undergoing 2 mo of intense exercise training (spontaneous running on an instrumented wheel). In mice evaluated at the beginning and at the end of training we determined: exercise performance (mean distance covered daily on the wheel); cardiac function in vivo (by magnetic resonance imaging); soleus mitochondrial respiration ex vivo (by high-resolution respirometry); muscle phenotype [myosin heavy chain (MHC) isoform content; citrate synthase (CS) activity]; and variables related to the energy status of muscle fibers [ratio of phosphorylated 5'-AMP-activated protein kinase (AMPK) to unphosphorylated AMPK] and mitochondrial biogenesis and function [peroxisome proliferative-activated receptor-γ coactivator-α (PGC-1α)]. In the untrained Tgα q *44 mice functional impairments of exercise performance, cardiac function, and soleus muscle mitochondrial respiration were observed. The impairment of mitochondrial respiration was related to the function of complex I of the respiratory chain, and it was not associated with differences in CS activity, MHC isoforms, p-AMPK/AMPK, and PGC-1α levels. Exercise training improved exercise performance and cardiac function, but it did not affect mitochondrial respiration, even in the presence of an increased percentage of type 1 MHC isoforms. Factors "upstream" of mitochondria were likely mainly responsible for the improved exercise performance. NEW & NOTEWORTHY Functional impairments in exercise performance, cardiac function, and soleus muscle mitochondrial respiration were observed in transgenic chronic heart failure mice, evaluated in the critical period between the occurrence of an impairment of cardiac function and the terminal stage of the disease. Exercise training improved exercise performance and cardiac function, but it did not affect the impaired mitochondrial respiration. Factors "upstream" of mitochondria, including an enhanced cardiovascular O 2 delivery, were mainly responsible for the functional improvement. Copyright © 2017 the American Physiological Society.

Chronic intermittent fasting improves cognitive functions and brain structures in mice.

PubMed

Li, Liaoliao; Wang, Zhi; Zuo, Zhiyi

2013-01-01

Obesity is a major health issue. Obesity started from teenagers has become a major health concern in recent years. Intermittent fasting increases the life span. However, it is not known whether obesity and intermittent fasting affect brain functions and structures before brain aging. Here, we subjected 7-week old CD-1 wild type male mice to intermittent (alternate-day) fasting or high fat diet (45% caloric supplied by fat) for 11 months. Mice on intermittent fasting had better learning and memory assessed by the Barnes maze and fear conditioning, thicker CA1 pyramidal cell layer, higher expression of drebrin, a dendritic protein, and lower oxidative stress than mice that had free access to regular diet (control mice). Mice fed with high fat diet was obese and with hyperlipidemia. They also had poorer exercise tolerance. However, these obese mice did not present significant learning and memory impairment or changes in brain structures or oxidative stress compared with control mice. These results suggest that intermittent fasting improves brain functions and structures and that high fat diet feeding started early in life does not cause significant changes in brain functions and structures in obese middle-aged animals.

Chronic Intermittent Fasting Improves Cognitive Functions and Brain Structures in Mice

PubMed Central

Li, Liaoliao; Wang, Zhi; Zuo, Zhiyi

2013-01-01

Obesity is a major health issue. Obesity started from teenagers has become a major health concern in recent years. Intermittent fasting increases the life span. However, it is not known whether obesity and intermittent fasting affect brain functions and structures before brain aging. Here, we subjected 7-week old CD-1 wild type male mice to intermittent (alternate-day) fasting or high fat diet (45% caloric supplied by fat) for 11 months. Mice on intermittent fasting had better learning and memory assessed by the Barnes maze and fear conditioning, thicker CA1 pyramidal cell layer, higher expression of drebrin, a dendritic protein, and lower oxidative stress than mice that had free access to regular diet (control mice). Mice fed with high fat diet was obese and with hyperlipidemia. They also had poorer exercise tolerance. However, these obese mice did not present significant learning and memory impairment or changes in brain structures or oxidative stress compared with control mice. These results suggest that intermittent fasting improves brain functions and structures and that high fat diet feeding started early in life does not cause significant changes in brain functions and structures in obese middle-aged animals. PMID:23755298

Antiinflammatory and Antimicrobial Effects of Thiocyanate in a Cystic Fibrosis Mouse Model

PubMed Central

Chandler, Joshua D.; Min, Elysia; Huang, Jie; McElroy, Cameron S.; Dickerhof, Nina; Mocatta, Tessa; Fletcher, Ashley A.; Evans, Christopher M.; Liang, Liping; Patel, Manisha; Kettle, Anthony J.; Nichols, David P.

2015-01-01

Thiocyanate (SCN) is used by the innate immune system, but less is known about its impact on inflammation and oxidative stress. Granulocytes oxidize SCN to evolve the bactericidal hypothiocyanous acid, which we previously demonstrated is metabolized by mammalian, but not bacterial, thioredoxin reductase (TrxR). There is also evidence that SCN is dysregulated in cystic fibrosis (CF), a disease marked by chronic infection and airway inflammation. To investigate antiinflammatory effects of SCN, we administered nebulized SCN or saline to β epithelial sodium channel (βENaC) mice, a phenotypic CF model. SCN significantly decreased airway neutrophil infiltrate and restored the redox ratio of glutathione in lung tissue and airway epithelial lining fluid to levels comparable to wild type. Furthermore, in Pseudomonas aeruginosa–infected βENaC and wild-type mice, SCN decreased inflammation, proinflammatory cytokines, and bacterial load. SCN also decreased airway neutrophil chemokine keratinocyte chemoattractant (also known as C-X-C motif chemokine ligand 1) and glutathione sulfonamide, a biomarker of granulocyte oxidative activity, in uninfected βENaC mice. Lung tissue TrxR activity and expression increased in inflamed lung tissue, providing in vivo evidence for the link between hypothiocyanous acid metabolism by TrxR and the promotion of selective biocide of pathogens. SCN treatment both suppressed inflammation and improved host defense, suggesting that nebulized SCN may have important therapeutic utility in diseases of both chronic airway inflammation and persistent bacterial infection, such as CF. PMID:25490247

The temporal impact of chronic intermittent psychosocial stress on high-fat diet-induced alterations in body weight.

PubMed

Finger, Beate C; Dinan, Timothy G; Cryan, John F

2012-06-01

Chronic stress and diet can independently or in concert influence the body's homeostasis over time. Thus, it is crucial to investigate the interplay of these parameters to gain insight into the evolution of stress-induced metabolic and eating disorders. C57BL/6J mice were subjected to chronic psychosocial (mixed model of social defeat and overcrowding) stress in combination with either a high- or low-fat diet for three or six weeks. To determine the evolution of stress and dietary effects, changes in body weight, caloric intake and caloric efficiency were determined as well as circulating leptin, insulin, glucose and corticosterone levels and social avoidance behaviour. Exposure to stress for three weeks caused an increase in weight gain, in caloric intake and in caloric efficiency only in mice on a low-fat diet. However, after six weeks, only stressed mice on a high-fat diet displayed a pronounced inhibition of body weight gain, accompanied by reduced caloric intake and caloric efficiency. Stress decreased circulating leptin levels in mice on a low-fat diet after three weeks and in mice on a high-fat diet after three and six weeks of exposure. Plasma levels of insulin and markers of insulin resistance were blunted in mice on high-fat diet following six weeks of stress exposure. Social avoidance following chronic stress was present in all mice after three and six weeks. This study describes the evolution of the chronic effects of social defeat/overcrowding stress in combination with exposure to high- or low-fat diet. Most importantly, we demonstrate that a six week chronic exposure to social defeat stress prevents the metabolic effects of high-fat diet, by inhibiting an increase in weight gain, caloric intake and efficiency and insulin resistance as well as in plasma leptin and insulin levels. This study highlights the importance of considering the chronic aspects of both parameters and their time-dependent interplay. Copyright © 2011 Elsevier Ltd. All rights reserved.

Studies of Scleral Biomechanical Behavior Related to Susceptibility for Retinal Ganglion Cell Loss in Experimental Mouse Glaucoma

PubMed Central

Nguyen, Cathy; Cone, Frances E.; Nguyen, Thao D.; Coudrillier, Baptiste; Pease, Mary E.; Steinhart, Matthew R.; Oglesby, Ericka N.; Jefferys, Joan L.; Quigley, Harry A.

2013-01-01

Purpose. To study anatomical changes and mechanical behavior of the sclera in mice with experimental glaucoma by comparing CD1 to B6 mice. Methods. Chronic experimental glaucoma for 6 weeks was produced in 2- to 4-month-old CD1 (43 eyes) and B6 mice (42 eyes) using polystyrene bead injection into the anterior chamber with 126 control CD1 and 128 control B6 eyes. Intraocular pressure (IOP) measurements were made with the TonoLab at baseline and after bead injection. Axial length and scleral thickness were measured after sacrifice in the CD1 and B6 animals and compared to length data from 78 eyes of DBA/2J mice. Inflation testing of posterior sclera was conducted, and circumferential and meridional strain components were determined from the displacement response. Results. Experimental glaucoma led to increases in axial length and width by comparison to fellow eyes (6% in CD1 and 10% in B6; all P < 0.03). While the peripapillary sclera became thinner in both mouse types with glaucoma, the remainder of the sclera uniformly thinned in CD1, but thickened in B6. Peripapillary sclera in CD1 controls had significantly greater temporal meridional strain than B6 and had differences in the ratios of meridional to effective circumferential strain from B6 mice. In both CD1 and B6 mice, exposure to chronic IOP elevation resulted in stiffer pressure–strain responses for both the effective circumferential and meridional strains (multivariable regression model, P = 0.01–0.03). Conclusions. Longer eyes, greater scleral strain in some directions at baseline, and generalized scleral thinning after glaucoma were characteristic of CD1 mice that have greater tendency to retinal ganglion cell damage than B6 mice. Increased scleral stiffness after glaucoma exposure in mice mimics findings in monkey and human glaucoma eyes. PMID:23404116

Effects of CYP-induced cystitis on PACAP/VIP and receptor expression in micturition pathways and bladder function in mice with overexpression of NGF in urothelium.

PubMed

Girard, Beatrice M; Tompkins, John D; Parsons, Rodney L; May, Victor; Vizzard, Margaret A

2012-11-01

We have previously demonstrated nerve growth factor (NGF) regulation of pituitary adenylate cyclase-activating polypeptide (PACAP)/receptors in bladder reflex pathways using a transgenic mouse model of chronic NGF overexpression in the bladder using the urothelial-specific uroplakin II promoter. We have now explored the contribution of target-derived NGF in combination with cyclophosphamide (CYP)-induced cystitis to determine whether additional changes in neuropeptides/receptors are observed in micturition reflex pathways due to the presence of additional inflammatory mediators in the urinary bladder. Quantitative PCR was used to determine PACAP/vasoactive intestinal polypeptide (VIP), substance P, galanin, and receptor transcript expression in the urinary bladder (urothelium, detrusor) in mice with overexpression of NGF in the urothelium (NGF-OE) and wild-type (WT) mice with CYP-induced cystitis (4 h, 48 h, and chronic). With CYP-induced cystitis (4 h), WT and NGF-OE mice exhibited similar changes in galanin transcript expression in the urothelium (30-fold increase) and detrusor (threefold increase). In contrast, PACAP, VIP, and substance P transcripts exhibited differential changes in WT and NGF-OE with CYP-induced cystitis. PAC1, VPAC1, and VPAC2 transcript expression also exhibited differential responses in NGF-OE mice that were tissue (urothelium vs. detrusor) and CYP-induced cystitis duration-dependent. Using conscious cystometry, NGF-OE mice treated with CYP exhibited significant (p ≤ 0.01) increases in voiding frequency above that observed in control NGF-OE mice. In addition, no changes in the electrical properties of the major pelvic ganglia neurons of NGF-OE mice were detected using intracellular recording, suggesting that the urinary bladder phenotype in NGF-OE mice is not influenced by changes in the efferent limb of the micturition reflex. These studies are consistent with target-derived NGF and other inflammatory mediators affecting neurochemical plasticity and the reflex function of micturition pathways.

Both cardiomyocyte and endothelial cell Nox4 mediate protection against hemodynamic overload-induced remodelling.

PubMed

Zhang, Min; Mongue-Din, Heloise; Martin, Daniel; Catibog, Norman; Smyrnias, Ioannis; Zhang, Xiaohong; Yu, Bin; Wang, Minshu; Brandes, Ralf P; Schröder, Katrin; Shah, Ajay M

2018-03-01

NADPH oxidase-4 (Nox4) is an important reactive oxygen species (ROS) source that is upregulated in the haemodynamically overloaded heart. Our previous studies using global Nox4 knockout (Nox4KO) mice demonstrated a protective role of Nox4 during chronic abdominal aortic banding, involving a paracrine enhancement of myocardial capillary density. However, other authors who studied cardiac-specific Nox4KO mice reported detrimental effects of Nox4 in response to transverse aortic constriction (TAC). It has been speculated that these divergent results are due to cell-specific actions of Nox4 (i.e. cardiomyocyte Nox4 detrimental but endothelial Nox4 beneficial) and/or differences in the model of pressure overload (i.e. abdominal banding vs. TAC). This study aimed to (i) investigate whether the effects of Nox4 on pressure overload-induced cardiac remodelling vary according to the pressure overload model and (ii) compare the roles of cardiomyocyte vs. endothelial cell Nox4. Global Nox4KO mice subjected to TAC developed worse cardiac remodelling and contractile dysfunction than wild-type littermates, consistent with our previous results with abdominal aortic banding. Next, we generated inducible cardiomyocyte-specific Nox4 KO mice (Cardio-Nox4KO) and endothelial-specific Nox4 KO mice (Endo-Nox4KO) and studied their responses to pressure overload. Both Cardio-Nox4KO and Endo-Nox4KO developed worse pressure overload-induced cardiac remodelling and dysfunction than wild-type littermates, associated with significant decrease in protein levels of HIF1α and VEGF and impairment of myocardial capillarization. Cardiomyocyte as well as endothelial cell Nox4 contributes to protection against chronic hemodynamic overload-induced cardiac remodelling, at least in part through common effects on myocardial capillary density. © The Author 2017 Published by Oxford University Press on behalf of the European Society of Cardiology.

Prevention of Diet-Induced Obesity Effects on Body Weight and Gut Microbiota in Mice Treated Chronically with Δ9-Tetrahydrocannabinol

PubMed Central

Cluny, Nina L.; Keenan, Catherine M.; Reimer, Raylene A.; Le Foll, Bernard; Sharkey, Keith A.

2015-01-01

Objective Acute administration of cannabinoid CB1 receptor agonists, or the ingestion of cannabis, induces short-term hyperphagia. However, the incidence of obesity is lower in frequent cannabis users compared to non-users. Gut microbiota affects host metabolism and altered microbial profiles are observed in obese states. Gut microbiota modifies adipogenesis through actions on the endocannabinoid system. This study investigated the effect of chronic THC administration on body weight and gut microbiota in diet-induced obese (DIO) and lean mice. Methods Adult male DIO and lean mice were treated daily with vehicle or THC (2mg/kg for 3 weeks and 4 mg/kg for 1 additional week). Body weight, fat mass, energy intake, locomotor activity, whole gut transit and gut microbiota were measured longitudinally. Results THC reduced weight gain, fat mass gain and energy intake in DIO but not lean mice. DIO-induced changes in select gut microbiota were prevented in mice chronically administered THC. THC had no effect on locomotor activity or whole gut transit in either lean or DIO mice. Conclusions Chronic THC treatment reduced energy intake and prevented high fat diet-induced increases in body weight and adiposity; effects that were unlikely to be a result of sedation or altered gastrointestinal transit. Changes in gut microbiota potentially contribute to chronic THC-induced actions on body weight in obesity. PMID:26633823

Prevention of Diet-Induced Obesity Effects on Body Weight and Gut Microbiota in Mice Treated Chronically with Δ9-Tetrahydrocannabinol.

PubMed

Cluny, Nina L; Keenan, Catherine M; Reimer, Raylene A; Le Foll, Bernard; Sharkey, Keith A

2015-01-01

Acute administration of cannabinoid CB1 receptor agonists, or the ingestion of cannabis, induces short-term hyperphagia. However, the incidence of obesity is lower in frequent cannabis users compared to non-users. Gut microbiota affects host metabolism and altered microbial profiles are observed in obese states. Gut microbiota modifies adipogenesis through actions on the endocannabinoid system. This study investigated the effect of chronic THC administration on body weight and gut microbiota in diet-induced obese (DIO) and lean mice. Adult male DIO and lean mice were treated daily with vehicle or THC (2mg/kg for 3 weeks and 4 mg/kg for 1 additional week). Body weight, fat mass, energy intake, locomotor activity, whole gut transit and gut microbiota were measured longitudinally. THC reduced weight gain, fat mass gain and energy intake in DIO but not lean mice. DIO-induced changes in select gut microbiota were prevented in mice chronically administered THC. THC had no effect on locomotor activity or whole gut transit in either lean or DIO mice. Chronic THC treatment reduced energy intake and prevented high fat diet-induced increases in body weight and adiposity; effects that were unlikely to be a result of sedation or altered gastrointestinal transit. Changes in gut microbiota potentially contribute to chronic THC-induced actions on body weight in obesity.

Deletion of Ku80 causes early aging independent of chronic inflammation and Rag-1-induced DSBs.

PubMed

Holcomb, Valerie B; Vogel, Hannes; Hasty, Paul

2007-01-01

Animal models of premature aging are often defective for DNA repair. Ku80-mutant mice are disabled for nonhomologous end joining; a pathway that repairs both spontaneous DNA double-strand breaks (DSBs) and induced DNA DSBs generated by the action of a complex composed of Rag-1 and Rag-2 (Rag). Rag is essential for inducing DSBs important for assembling V(D)J segments of antigen receptor genes that are required for lymphocyte development. Thus, deletion of either Rag-1 or Ku80 causes severe combined immunodeficiency (scid) leading to chronic inflammation. In addition, Rag-1 induces breaks at non-B DNA structures. Previously we reported Ku80-mutant mice undergo premature aging, yet we do not know the root cause of this phenotype. Early aging may be caused by either defective repair of spontaneous DNA damage, defective repair of Rag-1-induced breaks or chronic inflammation caused by scid. To address this issue, we analyzed aging in control and Ku80-mutant mice deleted for Rag-1 such that both cohorts are scid and suffer from chronic inflammation. We make two observations: (1) chronic inflammation does not cause premature aging in these mice and (2) Ku80-mutant mice exhibit early aging independent of Rag-1. Therefore, this study supports defective repair of spontaneous DNA damage as the root cause of early aging in Ku80-mutant mice.

[Unpredictable chronic mild stress effects on antidepressants activities in forced swim test].

PubMed

Kudryashov, N V; Kalinina, T S; Voronina, T A

2015-02-01

The experiments has been designed to study unpredictable chronic mild stress effect on anti-depressive activities of amitriptyline (10 mg/kg) and fluoxetine (20 mg/kg) in forced swim test in male outbred mice. It is shown that acute treatment with fluoxetine does not produce any antidepressant effects in mice following stress of 14 days while the sub-chronic injections of fluoxetine result in more deep depressive-like behavior. In 28 daily stressed mice, antidepressant effect of fluoxetine is observed independently of the injection rates. Amitriptyline demonstrates the antidepressant activity regardless of the duration of stress or administration scheduling, but at the same time the severity of anti-immobilization effect of amitriptyline in stressed mice is weaker in compare to non-stressed trails. Thus, the injection rates and duration of unpredictable mild chronic stress are the parameters that determine the efficiency of antidepressants in the mouse forced swimming test.

The Immunotherapeutic Role of Bacterial Lysates in a Mouse Model of Asthma.

PubMed

Liu, Chentao; Huang, Rong; Yao, Rujie; Yang, Aimei

2017-10-01

Asthma is the most common chronic lower respiratory disease in childhood throughout the world. Recurrent respiratory tract infections in young children, especially viral infections, are the major cause of acute asthmatic exacerbations and contribute to development of asthma. Bacterial extracts have been used to improve the immune defenses of the respiratory tract. However, seldom studies have examined the effect of bacterial lysates on childhood asthma. In this study, we examined whether bacterial lysates (OM-85) will improve symptoms of asthmatic mice via modulation of the immune response. Asthmatic mice models were established with OVA challenge and treated with oral administration of Broncho-Vaxom (OM-85). Next, infiltrations of inflammatory cells including eosinophil and neutrophils were examined. Pulmonary tissues in asthmatic mice models were analyzed by hematoxylin and eosin (HE) staining. The levels of Th1/Th2-typed cytokines in bronchoalveolar lavage fluid (BALF) of asthmatic mice models were examined by enzyme-linked immunosorbent assay. Compared to control group, we found significant reduction of airway wall thickness, luminal stenosis, and mucus plug formation in asthmatic mice models after oral administration of OM-85. The infiltrations of eosinophil were also significantly decreased in BALF in asthmatic mice models. Oral administration of OM-85 was shown to suppress Th2-type cytokine levels. Our findings provide evidence that oral administration of OM-85 is capable of attenuating airway inflammation in asthmatic mice models. Oral administration of OM-85 may have a positive impact in terms of asthma severity.

Fluvoxamine moderates reduced voluntary activity following chronic dexamethasone infusion in mice via recovery of BDNF signal cascades.

PubMed

Terada, Kazuki; Izumo, Nobuo; Suzuki, Biora; Karube, Yoshiharu; Morikawa, Tomomi; Ishibashi, Yukiko; Kameyama, Toshiki; Chiba, Koji; Sasaki, Noriko; Iwata, Keiko; Matsuzaki, Hideo; Manabe, Takayuki

2014-04-01

Major depression is a complex disorder characterized by genetic and environmental interactions. Selective serotonin reuptake inhibitors (SSRIs) effectively treat depression. Neurogenesis following chronic antidepressant treatment activates brain derived neurotrophic factor (BDNF) signaling. In this study, we analyzed the effects of the SSRI fluvoxamine (Flu) on locomotor activity and forced-swim behavior using chronic dexamethasone (cDEX) infusions in mice, which engenders depression-like behavior. Infusion of cDEX decreased body weight and produced a trend towards lower locomotor activity during darkness. In the forced-swim test, cDEX-mice exhibited increased immobility times compared with mice administered saline. Flu treatment reversed decreased locomotor activity and mitigated forced-swim test immobility. Real-time polymerase chain reactions using brain RNA samples yielded significantly lower BDNF mRNA levels in cDEX-mice compared with the saline group. Endoplasmic reticulum stress-associated X-box binding protein-1 (XBP1) gene expression was lower in cDEX-mice compared with the saline group. However, marked expression of the XBP1 gene was observed in cDEX-mice treated with Flu compared with mice given saline and untreated cDEX-mice. Expression of 5-HT2A and Sigma-1 receptors decreased after cDEX infusion compared with the saline group, and these decreases normalized to control levels upon Flu treatment. Our results indicate that the Flu moderates reductions in voluntary activity following chronic dexamethasone infusions in mice via recovery of BDNF signal cascades. Copyright © 2014 Elsevier Ltd. All rights reserved.

[Study on effect of jinshui liujun jian oral liquid on serum superoxide dismutase activity and malonyldialdehyde content in mice with chronic bronchitis].

PubMed

Zhao, C Y; Shen, Y S; Meng, H

2001-11-01

To study the effect of Jinshui Liujun Jian Oral Liquid (JLJOL) on serum superoxide dismutase (SOD) activity and malonyldialdehyde (MDA) content in mice with chronic bronchitis. JLJOL was given to the chronic bronchitis mice model (induced by smoking) through gastrogavage, and then SOD activity and MDA content were tested. SOD activity in model mice after JLJOL treatment was 0.67 +/- 0.15 NU/L, which was significantly higher than that in the untreated model (0.39 +/- 0.13 NU/L, P < 0.01). But the MDA content in treated mice was significantly lower than that in untreated one (9.26 +/- 2.90 nmol/L vs 16.07 +/- 5.62 nmol/L, P < 0.01). JLJOL could scavenge the injury of free radical on organism.

Defective renal water handling in transgenic mice over-expressing human CD39/NTPDase1

PubMed Central

Zhang, Yue; Morris, Kaiya L.; Sparrow, Shannon K.; Dwyer, Karen M.; Enjyoji, Keiichi; Robson, Simon C.

2012-01-01

Ectonucleoside triphosphate diphosphohydrolase-1 hydrolyzes extracellular ATP and ADP to AMP. Previously, we showed that CD39 is expressed at several sites within the kidney and thus may impact the availability of type 2 purinergic receptor (P2-R) ligands. Because P2-Rs appear to regulate urinary concentrating ability, we have evaluated renal water handling in transgenic mice (TG) globally overexpressing hCD39. Under basal conditions, TG mice exhibited significantly impaired urinary concentration and decreased protein abundance of AQP2 in the kidney compared with wild-type (WT) mice. Urinary excretion of total nitrates/nitrites was significantly higher in TG mice, but the excretion of AVP or PGE2 was equivalent to control WT mice. There were no significant differences in electrolyte-free water clearance or fractional excretion of sodium. Under stable hydrated conditions (gelled diet feeding), the differences between the WT and TG mice were negated, but the decrease in urine osmolality persisted. When water deprived, TG mice failed to adequately concentrate urine and exhibited impaired AVP responses. However, the increases in urinary osmolalities in response to subacute dDAVP or chronic AVP treatment were similar in TG and WT mice. These observations suggest that TG mice have impaired urinary concentrating ability despite normal AVP levels. We also note impaired AVP release in response to water deprivation but that TG kidneys are responsive to exogenous dDAVP or AVP. We infer that heightened nucleotide scavenging by increased levels of CD39 altered the release of endogenous AVP in response to dehydration. We propose that ectonucleotidases and modulated purinergic signaling impact urinary concentration and indicate potential utility of targeted therapy for the treatment of water balance disorders. PMID:22622462

Different effects of oral administration of synthetic trypsin inhibitor on the pancreas between cholecystokinin-A receptor gene knockout mice and wild type mice.

PubMed

Sato, Norikazu; Suzuki, Shinji; Kanai, Setsuko; Ohta, Minoru; Jimi, Atsuo; Noda, Tetsuo; Takiguchi, Souichi; Funakoshi, Akihiro; Miyasaka, Kyoko

2002-07-01

The synthetic trypsin inhibitor camostat has been used for the treatment of acute and chronic pancreatitis in Japan based on the evidences obtained from a rat experimental model. However, rats differ from other rodents and from humans in terms of lacking a gallbladder and no response of pancreatic bicarbonate secretion to cholecystokinin (CCK). In the present study, we determined whether oral administration of camostat showed a trophic effect in mice as observed in rats and whether the trophic effect, if substantial, was mediated via the CCK-A receptor, using CCK-A receptor gene targeting mice. The chow containing 0.1% camostat was fed to 8-month-old mice. Three- and seven-day treatments with camostat did not affect pancreatic wet weight in CCK-A receptor (+/-) mice. After 14-day treatment, the ratio of pancreatic wet weight/body weight was significantly lower in CCK-A receptor (-/-) than (+/+) mice. The protein and chymotrypsin contents were lower and amylase content was higher in CCK-A receptor (-/-) mice, compared to (+/+) mice. No pathological findings were observed by histological examination. Camostat has a trophic effect on the pancreas in mice and this effect is mediated via the CCK-A receptor, but is less potent than in rats.

Genetic background effects of keratin 8 and 18 in a DDC-induced hepatotoxicity and Mallory-Denk body formation mouse model.

PubMed

Haybaeck, Johannes; Stumptner, Cornelia; Thueringer, Andrea; Kolbe, Thomas; Magin, Thomas M; Hesse, Michael; Fickert, Peter; Tsybrovskyy, Oleksiy; Müller, Heimo; Trauner, Michael; Zatloukal, Kurt; Denk, Helmut

2012-06-01

Keratin 8 (K8) and keratin 18 (K18) form the major hepatocyte cytoskeleton. We investigated the impact of genetic loss of either K8 or K18 on liver homeostasis under toxic stress with the hypothesis that K8 and K18 exert different functions. krt8⁻/⁻ and krt18⁻/⁻ mice crossed into the same 129-ola genetic background were treated by acute and chronic administration of 3,5-diethoxy-carbonyl-1,4-dihydrocollidine (DDC). In acutely DDC-intoxicated mice, macrovesicular steatosis was more pronounced in krt8⁻/⁻ and krt18⁻/⁻ compared with wild-type (wt) animals. Mallory-Denk bodies (MDBs) appeared in krt18⁻/⁻ mice already at an early stage of intoxication in contrast to krt8⁻/⁻ mice that did not display MDB formation when fed with DDC. Keratin-deficient mice displayed significantly lower numbers of apoptotic hepatocytes than wt animals. krt8⁻/⁻, krt18⁻/⁻ and control mice displayed comparable cell proliferation rates. Chronically DDC-intoxicated krt18⁻/⁻ and wt mice showed a similarly increased degree of steatohepatitis with hepatocyte ballooning and MDB formation. In krt8⁻/⁻ mice, steatosis was less, ballooning, and MDBs were absent. krt18⁻/⁻ mice developed MDBs whereas krt8⁻/⁻ mice on the same genetic background did not, highlighting the significance of different structural properties of keratins. They are independent of the genetic background as an intrinsic factor. By contrast, toxicity effects may depend on the genetic background. krt8⁻/⁻ and krt18⁻/⁻ mice on the same genetic background show similar sensitivity to DDC intoxication and almost resemble wt animals regarding survival, degree of porphyria, liver-to-body weight ratio, serum bilirubin and liver enzyme levels. This stands in contrast to previous work where krt8⁻/⁻ and krt18⁻/⁻ mice on different genetic backgrounds were investigated.

Circadian rhythm disruption impairs tissue homeostasis and exacerbates chronic inflammation in the intestine.

PubMed

Pagel, René; Bär, Florian; Schröder, Torsten; Sünderhauf, Annika; Künstner, Axel; Ibrahim, Saleh M; Autenrieth, Stella E; Kalies, Kathrin; König, Peter; Tsang, Anthony H; Bettenworth, Dominik; Divanovic, Senad; Lehnert, Hendrik; Fellermann, Klaus; Oster, Henrik; Derer, Stefanie; Sina, Christian

2017-11-01

Endogenous circadian clocks regulate 24-h rhythms of physiology and behavior. Circadian rhythm disruption (CRD) is suggested as a risk factor for inflammatory bowel disease. However, the underlying molecular mechanisms remain unknown. Intestinal biopsies from Per1/2 mutant and wild-type (WT) mice were investigated by electron microscopy, immunohistochemistry, and bromodeoxyuridine pulse-chase experiments. TNF-α was injected intraperitoneally, with or without necrostatin-1, into Per1/2 mice or rhythmic and externally desynchronized WT mice to study intestinal epithelial cell death. Experimental chronic colitis was induced by oral administration of dextran sodium sulfate. In vitro , caspase activity was assayed in Per1/2-specific small interfering RNA-transfected cells. Wee1 was overexpressed to study antiapoptosis and the cell cycle. Genetic ablation of circadian clock function or environmental CRD in mice increased susceptibility to severe intestinal inflammation and epithelial dysregulation, accompanied by excessive necroptotic cell death and a reduced number of secretory epithelial cells. Receptor-interacting serine/threonine-protein kinase (RIP)-3-mediated intestinal necroptosis was linked to increased mitotic cell cycle arrest via Per1/2-controlled Wee1, resulting in increased antiapoptosis via cellular inhibitor of apoptosis-2. Together, our data suggest that circadian rhythm stability is pivotal for the maintenance of mucosal barrier function. CRD increases intestinal necroptosis, thus rendering the gut epithelium more susceptible to inflammatory processes.-Pagel, R., Bär, F., Schröder, T., Sünderhauf, A., Künstner, A., Ibrahim, S. M., Autenrieth, S. E., Kalies, K., König, P., Tsang, A. H., Bettenworth, D., Divanovic, S., Lehnert, H., Fellermann, K., Oster, H., Derer, S., Sina, C. Circadian rhythm disruption impairs tissue homeostasis and exacerbates chronic inflammation in the intestine. © FASEB.

Chronic Corticosterone Exposure Increases Expression and Decreases Deoxyribonucleic Acid Methylation of Fkbp5 in Mice

PubMed Central

Lee, Richard S.; Tamashiro, Kellie L. K.; Yang, Xiaoju; Purcell, Ryan H.; Harvey, Amelia; Willour, Virginia L.; Huo, Yuqing; Rongione, Michael; Wand, Gary S.; Potash, James B.

2010-01-01

There is evidence for hypercortisolemia playing a role in the generation of psychiatric symptoms and for epigenetic variation within hypothalamic-pituitary-adrenal (HPA) axis genes mediating behavioral changes. We tested the hypothesis that expression changes would be induced in Fkbp5 and other HPA axis genes by chronic exposure to corticosterone and that these changes would occur through the epigenetic mechanism of loss or gain of DNA methylation (DNAm). We administered corticosterone (CORT) to C57BL/6J mice via their drinking water for 4 wk and tested for behavioral and physiological changes and changes in gene expression levels using RNA extracted from hippocampus, hypothalamus, and blood for the following HPA genes: Fkbp5, Nr3c1, Hsp90, Crh, and Crhr1. The CORT mice exhibited anxiety-like behavior in the elevated plus maze test. Chronic exposure to CORT also caused a significant decrease in the hippocampal and blood mRNA levels of Nr3c1 and a decrease in Hsp90 in blood and caused an increase in Fkbp5 for all tissues. Differences were seen in Fkbp5 methylation in hippocampus and hypothalamus. To isolate a single-cell type, we followed up with an HT-22 mouse hippocampal neuronal cell line exposed to CORT. After 7 d, we observed a 2.4-fold increase in Fkbp5 expression and a decrease in DNAm. In the CORT-treated mice, we also observed changes in blood DNAm in Fkbp5. Our results suggest DNAm plays a role in mediating effects of glucocorticoid exposure on Fkbp5 function, with potential consequences for behavior. PMID:20668026

Targeting the minor pocket of C5aR for the rational design of an oral allosteric inhibitor for inflammatory and neuropathic pain relief.

PubMed

Moriconi, Alessio; Cunha, Thiago M; Souza, Guilherme R; Lopes, Alexandre H; Cunha, Fernando Q; Carneiro, Victor L; Pinto, Larissa G; Brandolini, Laura; Aramini, Andrea; Bizzarri, Cinzia; Bianchini, Gianluca; Beccari, Andrea R; Fanton, Marco; Bruno, Agostino; Costantino, Gabriele; Bertini, Riccardo; Galliera, Emanuela; Locati, Massimo; Ferreira, Sérgio H; Teixeira, Mauro M; Allegretti, Marcello

2014-11-25

Chronic pain resulting from inflammatory and neuropathic disorders causes considerable economic and social burden. Pharmacological therapies currently available for certain types of pain are only partially effective and may cause severe adverse side effects. The C5a anaphylatoxin acting on its cognate G protein-coupled receptor (GPCR), C5aR, is a potent pronociceptive mediator in several models of inflammatory and neuropathic pain. Although there has long been interest in the identification of C5aR inhibitors, their development has been complicated, as for many peptidomimetic drugs, mostly by poor drug-like properties. Herein, we report the de novo design of a potent and selective C5aR noncompetitive allosteric inhibitor, DF2593A, guided by the hypothesis that an allosteric site, the "minor pocket," previously characterized in CXC chemokine receptors-1 and -2, is functionally conserved in the GPCR class. In vitro, DF2593A potently inhibited C5a-induced migration of human and rodent neutrophils. In vivo, oral administration of DF2593A effectively reduced mechanical hyperalgesia in several models of acute and chronic inflammatory and neuropathic pain, without any apparent side effects. Mechanical hyperalgesia after spared nerve injury was also reduced in C5aR(-/-) mice compared with WT mice. Furthermore, treatment of C5aR(-/-) mice with DF2593A did not produce any further antinociceptive effect compared with C5aR(-/-) mice treated with vehicle. The successful medicinal chemistry strategy confirms that a conserved minor pocket is amenable for the rational design of selective inhibitors and the pharmacological results support that the allosteric blockade of the C5aR represents a highly promising therapeutic approach to control chronic inflammatory and neuropathic pain.

Fructokinase activity mediates dehydration-induced renal injury.

PubMed

Roncal Jimenez, Carlos A; Ishimoto, Takuji; Lanaspa, Miguel A; Rivard, Christopher J; Nakagawa, Takahiko; Ejaz, A Ahsan; Cicerchi, Christina; Inaba, Shinichiro; Le, MyPhuong; Miyazaki, Makoto; Glaser, Jason; Correa-Rotter, Ricardo; González, Marvin A; Aragón, Aurora; Wesseling, Catharina; Sánchez-Lozada, Laura G; Johnson, Richard J

2014-08-01

The epidemic of chronic kidney disease in Nicaragua (Mesoamerican nephropathy) has been linked with recurrent dehydration. Here we tested whether recurrent dehydration may cause renal injury by activation of the polyol pathway, resulting in the generation of endogenous fructose in the kidney that might subsequently induce renal injury via metabolism by fructokinase. Wild-type and fructokinase-deficient mice were subjected to recurrent heat-induced dehydration. One group of each genotype was provided water throughout the day and the other group was hydrated at night, after the dehydration. Both groups received the same total hydration in 24 h. Wild-type mice that received delayed hydration developed renal injury, with elevated serum creatinine, increased urinary NGAL, proximal tubular injury, and renal inflammation and fibrosis. This was associated with activation of the polyol pathway, with increased renal cortical sorbitol and fructose levels. Fructokinase-knockout mice with delayed hydration were protected from renal injury. Thus, recurrent dehydration can induce renal injury via a fructokinase-dependent mechanism, likely from the generation of endogenous fructose via the polyol pathway. Access to sufficient water during the dehydration period can protect mice from developing renal injury. These studies provide a potential mechanism for Mesoamerican nephropathy.

Adiponectin modulates inflammatory reactions via calreticulin receptor–dependent clearance of early apoptotic bodies

PubMed Central

Takemura, Yukihiro; Ouchi, Noriyuki; Shibata, Rei; Aprahamian, Tamar; Kirber, Michael T.; Summer, Ross S.; Kihara, Shinji; Walsh, Kenneth

2007-01-01

Obesity and type 2 diabetes are associated with chronic inflammation. Adiponectin is an adipocyte-derived hormone with antidiabetic and antiinflammatory actions. Here, we demonstrate what we believe to be a previously undocumented activity of adiponectin, facilitating the uptake of early apoptotic cells by macrophages, an essential feature of immune system function. Adiponectin-deficient (APN-KO) mice were impaired in their ability to clear apoptotic thymocytes in response to dexamethasone treatment, and these animals displayed a reduced ability to clear early apoptotic cells that were injected into their intraperitoneal cavities. Conversely, adiponectin administration promoted the clearance of apoptotic cells by macrophages in both APN-KO and wild-type mice. Adiponectin overexpression also promoted apoptotic cell clearance and reduced features of autoimmunity in lpr mice whereas adiponectin deficiency in lpr mice led to a further reduction in apoptotic cell clearance, which was accompanied by exacerbated systemic inflammation. Adiponectin was capable of opsonizing apoptotic cells, and phagocytosis of cell corpses was mediated by the binding of adiponectin to calreticulin on the macrophage cell surface. We propose that adiponectin protects the organism from systemic inflammation by promoting the clearance of early apoptotic cells by macrophages through a receptor-dependent pathway involving calreticulin. PMID:17256056

Increased Neuronal DNA/RNA Oxidation in the Frontal Cortex of Mice Subjected to Unpredictable Chronic Mild Stress.

PubMed

Maluach, Alfred M; Misquitta, Keith A; Prevot, Thomas D; Fee, Corey; Sibille, Etienne; Banasr, Mounira; Andreazza, Ana C

2017-01-01

Chronic stress is implicated in the development of various psychiatric illnesses including major depressive disorder. Previous reports suggest that patients with major depressive disorder have increased levels of oxidative stress, including higher levels of DNA/RNA oxidation found in postmortem studies, especially within brain regions responsible for the cognitive and emotional processes disrupted in the disorder. Here, we aimed to investigate whether unpredictable chronic mild stress in mice induces neuronal DNA/RNA oxidation in the prelimbic, infralimbic, and cingulate cortices of the frontal cortex and the basolateral amygdala and to explore potential associations with depressive-like behaviors. We expected that animals subjected to unpredictable chronic mild stress will present higher levels of DNA/RNA oxidation, which will be associated with anxiety-/depressive-like behaviors. C57BL/6J mice were assigned to unpredictable chronic mild stress or nonstress conditions (n = 10/group, 50% females). Following five weeks of unpredictable chronic mild stress exposure, mice were tested in a series of behavioral tests measuring anxiety- and depressive-like behaviors. Frontal cortex and amygdala sections were then immunolabeled for neuronal nuclei, a marker of post-mitotic neurons and anti-8-hydroxy-2-deoxyguanosine/8-oxo-7,8-dihydroguanosine, which reflects both DNA and RNA oxidation. Levels of neuronal DNA/RNA oxidation were increased in the frontal cortex of mice subjected to unpredictable chronic mild stress ( p = 0.0207). Levels of neuronal DNA/RNA oxidation in the frontal cortex were positively correlated with z-emotionality scores for latency to feed in the novelty-suppressed feeding test ( p = 0.0031). Statistically significant differences were not detected in basolateral amygdala levels of neuronal DNA/RNA oxidation between nonstress- and unpredictable chronic mild stress-exposed mice, nor were correlations found with behavioral performances for this region. Our results demonstrate that unpredictable chronic mild stress induces a significant increase in neuronal DNA/RNA oxidation in the frontal cortex that correlate with behavioral readouts of the stress response. A lack of DNA/RNA oxidation alterations in the basolateral amygdala suggests greater vulnerability of frontal cortex neurons to DNA/RNA oxidation in response to unpredictable chronic mild stress. These findings add support to the hypothesis that chronic stress-induced damage to DNA/RNA may be an additional molecular mechanism underlying cellular dysfunctions associated with chronic stress and present in stress-related disorders.

Genetic ablation of P65 subunit of NF-κB in mdx mice to improve muscle physiological function.

PubMed

Yin, Xi; Tang, Ying; Li, Jian; Dzuricky, Anna T; Pu, Chuanqiang; Fu, Freddie; Wang, Bing

2017-10-01

Duchenne muscular dystrophy (DMD) is a genetic muscle disease characterized by dystrophin deficiency. Beyond gene replacement, the question of whether ablation of the p65 gene of nuclear factor-kappa B (NF-κB) in DMD can improve muscle physiology function is unknown. In this study, we investigated muscle physiological improvement in mdx mice (DMD model) with a genetic reduction of NF-κB. Muscle physiological function and histology were studied in 2-month-old mdx/p65 +/- , wild-type, mdx, and human minidystrophin gene transgenic mdx (TghΔDys/mdx) mice. Improved muscle physiological function was found in mdx/p65 +/- mice when compared with mdx mice; however, it was similar to TghΔDys/mdx mice. The results indicate that genetic reduction of p65 levels diminished chronic inflammation in dystrophic muscle, thus leading to amelioration of muscle pathology and improved muscle physiological function. The results show that inhibition of NF-κB may be a promising therapy when combined with gene therapy for DMD. Muscle Nerve 56: 759-767, 2017. © 2016 Wiley Periodicals, Inc.

Diazepam administration prevents testosterone decrease and lipofuscin accumulation in testis of mouse exposed to chronic noise stress.

PubMed

Ruffoli, R; Carpi, A; Giambelluca, M A; Grasso, L; Scavuzzo, M C; Giannessi F, F

2006-10-01

Lipofuscin is an autofluorescent and undegradable material, which accumulates in tissues during ageing and under different types of stress. Among these, oxidative stress represents a major trigger for lipofuscin formation. However, prolonged noise exposure is also an effective stressful stimuli. Diazepam may inhibit lipofuscinogenesis in liver and prevent the noise-induced reduction of the steroidogenesis in the adrenal gland. The aim of the study was to ascertain whether chronic noise exposure causes lipofuscin accumulation in mouse testis, and to evaluate the effects of diazepam administration. Eight-week old mice were either exposed for 6 weeks (6 h day(-1)) to white-noise (group A), or received diazepam (3 mg kg(-1), i.p.) before noise exposures (group B), while a further group was used as control (group C). Light fluorescence and transmission electron microscopy revealed lipofuscin in large amounts in the Leydig cells in mice of group A, which concomitantly had low serum testosterone levels; pre-treatment with diazepam occluded both effects. The present study indicates that: (i) chronic noise exposure causes lipofuscin accumulation at the level of the Leydig cells and a decrease in testosterone; (ii) all these effects are suppressed by pre-treatment with diazepam. As the Leydig cells represent the only cellular type of the interstitial testicular tissue having peripheral benzodiazepine receptors, these results could be explained by the capacity of the peripheral benzodiazepine receptors to prevent reactive oxygen species damage and to increase the resistance of these cells to oxidative stress.

Lymphotoxin-beta receptor signaling regulates hepatic stellate cell function and wound healing in a murine model of chronic liver injury.

PubMed

Ruddell, Richard G; Knight, Belinda; Tirnitz-Parker, Janina E E; Akhurst, Barbara; Summerville, Lesa; Subramaniam, V Nathan; Olynyk, John K; Ramm, Grant A

2009-01-01

Lymphotoxin-beta (LTbeta) is a proinflammatory cytokine and a member of the tumor necrosis factor (TNF) superfamily known for its role in mediating lymph node development and homeostasis. Our recent studies suggest a role for LTbeta in mediating the pathogenesis of human chronic liver disease. We hypothesize that LTbeta co-ordinates the wound healing response in liver injury via direct effects on hepatic stellate cells. This study used the choline-deficient, ethionine-supplemented (CDE) dietary model of chronic liver injury, which induces inflammation, liver progenitor cell proliferation, and portal fibrosis, to assess (1) the cellular expression of LTbeta, and (2) the role of LTbeta receptor (LTbetaR) in mediating wound healing, in LTbetaR(-/-) versus wild-type mice. In addition, primary isolates of hepatic stellate cells were treated with LTbetaR-ligands LTbeta and LTbeta-related inducible ligand competing for glycoprotein D binding to herpesvirus entry mediator on T cells (LIGHT), and mediators of hepatic stellate cell function and fibrogenesis were assessed. LTbeta was localized to progenitor cells immediately adjacent to activated hepatic stellate cells in the periportal region of the liver in wild-type mice fed the CDE diet. LTbetaR(-/-) mice fed the CDE diet showed significantly reduced fibrosis and a dysregulated immune response. LTbetaR was demonstrated on isolated hepatic stellate cells, which when stimulated by LTbeta and LIGHT, activated the nuclear factor kappa B (NF-kappaB) signaling pathway. Neither LTbeta nor LIGHT had any effect on alpha-smooth muscle actin, tissue inhibitor of metalloproteinase 1, transforming growth factor beta, or procollagen alpha(1)(I) expression; however, leukocyte recruitment-associated factors intercellular adhesion molecule 1 and regulated upon activation T cells expressed and secreted (RANTES) were markedly up-regulated. RANTES caused the chemotaxis of a liver progenitor cell line expressing CCR5. This study suggests that LTbetaR on hepatic stellate cells may be involved in paracrine signaling with nearby LTbeta-expressing liver progenitor cells mediating recruitment of progenitor cells, hepatic stellate cells, and leukocytes required for wound healing and regeneration during chronic liver injury.

Licochalcone F alleviates glucose tolerance and chronic inflammation in diet-induced obese mice through Akt and p38 MAPK.

PubMed

Bak, Eun-Jung; Choi, Kyung-Chul; Jang, Sungil; Woo, Gye-Hyeong; Yoon, Ho-Geun; Na, Younghwa; Yoo, Yun-Jung; Lee, Youngseok; Jeong, Yangsik; Cha, Jeong-Heon

2016-04-01

Licochalcone (lico) F is a novel synthetic retrochalcone. In this study, we investigated the anti-inflammatory effects of lico F in vitro, and its effects on obesity-induced chronic inflammation, glucose intolerance, and fatty liver in vivo. The inhibitory effects of lico F on TNFα-induced inflammation were investigated using NF-κB luciferase reporter assay and RT-PCR. Diet-induced obese mice were treated orally, once per day, with vehicle or lico F (10 mg/kg/day), for 3 weeks, and blood, liver, and adipose tissues were analyzed. Lico F inhibited TNFα-induced NF-κB activation and mRNA expression of TNFα, COX-2, IL-6, IL-1β, and NOS2. In obese mice, lico F administration significantly alleviated glucose tolerance without changes in body weight gain and food intake. Lico F reduced adipocyte size and macrophage infiltration into white adipose tissue and improved hepatic lesions, by decreasing fat droplets and glycogen deposition. The mRNA expression levels of TNFα, MCP-1, and CD68 in white adipose tissue also decreased markedly. Moreover, lico F enhanced Akt signaling, but reduced p38 MAPK signaling in white adipose tissue. Lico F had anti-inflammatory effects and showed beneficial effects on glucose metabolism, which could be partially caused by activation of the Akt signal pathway and obesity-induced chronic inflammation, probably by downregulating p38 signal pathway. Moreover, lico F could be used as a potential novel therapeutic compound against type 2 diabetes and obesity-induced chronic inflammation without the deleterious effects of body weight gain and fatty liver. Copyright © 2015 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.

[Effects of diazepam on mixed anxiety/depression state in male mice].

PubMed

Galiamina, A G; Smagin, D A; Kovalenko, I L; Bondar', N P; Kudriavtseva, N N

2013-11-01

Chronic social defeat stress in daily agonistic interactions leads to the development of mixed anxiety/depression state in male mice. This paper aimed to study the effects of chronic diazepam treatment on the psychoemotional state of these animals. Diazepam (0.5 mg/kg, i/p, Polfa Tarchomin S. A.) or saline was chronically injected into male mice for two weeks on the background of continuing agonistic interactions (preventive treatment) or into male mice with mixed anxiety/depression state after stopping of social confrontations (therapeutic treatment). Then, the animals were studied in the partition, plus-maze and Porsolt' tests, estimating the levels of communicativeness, anxiety and depressiveness, respectively. Preventive diazepam treatment had a weak protective anxiolytic and pro-depressive effect. The therapeutic diazepam treatment didn't influence on the anxiety and depression-like state. Chronic diazepam was ineffective for the treatment of the mixed anxiety/depression state in male mice. Different effects ofdiazepam on anxiety and depression-like states under preventive treatment confirmed our conclusion shown earlier about the independent development of these pathologies at least in our experimental paradigm.

Microbiota Promotes Chronic Pulmonary Inflammation by Enhancing IL-17A and Autoantibodies.

PubMed

Yadava, Koshika; Pattaroni, Céline; Sichelstiel, Anke K; Trompette, Aurélien; Gollwitzer, Eva S; Salami, Olawale; von Garnier, Christophe; Nicod, Laurent P; Marsland, Benjamin J

2016-05-01

Changes in the pulmonary microbiota are associated with progressive respiratory diseases including chronic obstructive pulmonary disease (COPD). Whether there is a causal relationship between these changes and disease progression remains unknown. To investigate the link between an altered microbiota and disease, we used a murine model of chronic lung inflammation that is characterized by key pathological features found in COPD and compared responses in specific pathogen-free (SPF) mice and mice depleted of microbiota by antibiotic treatment or devoid of a microbiota (axenic). Mice were challenged with LPS/elastase intranasally over 4 weeks, resulting in a chronically inflamed and damaged lung. The ensuing cellular infiltration, histological damage, and decline in lung function were quantified. Similar to human disease, the composition of the pulmonary microbiota was altered in diseased animals. We found that the microbiota richness and diversity were decreased in LPS/elastase-treated mice, with an increased representation of the genera Pseudomonas and Lactobacillus and a reduction in Prevotella. Moreover, the microbiota was implicated in disease development as mice depleted, or devoid, of microbiota exhibited an improvement in lung function, reduced inflammation, and lymphoid neogenesis. The absence of microbial cues markedly decreased the production of IL-17A, whereas intranasal transfer of fluid enriched with the pulmonary microbiota isolated from diseased mice enhanced IL-17A production in the lungs of antibiotic-treated or axenic recipients. Finally, in mice harboring a microbiota, neutralizing IL-17A dampened inflammation and restored lung function. Collectively, our data indicate that host-microbial cross-talk promotes inflammation and could underlie the chronicity of inflammatory lung diseases.

Chronic exercise prevents repeated restraint stress-provoked enhancement of immobility in forced swimming test in ovariectomized mice.

PubMed

Han, Tae-Kyung; Lee, Jang-Kyu; Leem, Yea-Hyun

2015-06-01

We assessed whether chronic treadmill exercise attenuated the depressive phenotype induced by restraint stress in ovariectomized mice (OVX). Immobility of OVX in the forced swimming test was comparable to that of sham mice (CON) regardless of the postoperative time. Immobility was also no difference between restrained mice (exposure to periodic restraint for 21 days; RST) and control mice (CON) on post-exposure 2nd and 9th day, but not 15th day. In contrast, the immobility of ovariectomized mice with repeated stress (OVX + RST) was profoundly enhanced compared to ovariectomized mice-alone (OVX), and this effect was reversed by chronic exercise (19 m/min, 60 min/day, 5 days/week for 8 weeks; OVX + RST + Ex) or fluoxetine administration (20 mg/kg, OVX + RST + Flu). In parallel with behavioral data, the immunoreactivity of Ki-67 and doublecortin (DCX) in OVX was significantly decreased by repeated stress. However, the reduced numbers of Ki-67- and DCX-positive cells in OVX + RST were restored in response to chronic exercise (OVX + RST + Ex) and fluoxetine (OVX + RST + Flu). In addition, the expression pattern of cAMP response element-binding protein (CREB) and calcium-calmodulin-dependent kinase IV (CaMKIV) was similar to that of the hippocampal proliferation and neurogenesis markers (Ki-67 and DCX, respectively). These results suggest that menopausal depression may be induced by an interaction between repeated stress and low hormone levels, rather than a deficit in ovarian secretion alone, which can be improved by chronic exercise.

Resolution of inflammation by interleukin-9-producing type 2 innate lymphoid cells

PubMed Central

Rauber, Simon; Luber, Markus; Weber, Stefanie; Maul, Lisa; Soare, Alina; Wohlfahrt, Thomas; Lin, Neng-Yu; Dietel, Katharina; Bozec, Aline; Herrmann, Martin; Kaplan, Mark H.; Weigmann, Benno; Zaiss, Mario M.; Fearon, Ursula; Veale, Douglas J.; Canete, Juan D.; Distler, Oliver; Rivellese, Felice; Pitzalis, Costantino; Neurath, Markus F.; McKenzie, Andrew N.J.; Wirtz, Stefan; Schett, Georg; Distler, Jörg H.W.; Ramming, Andreas

2017-01-01

Inflammatory diseases such as arthritis are chronic conditions that fail to resolve spontaneously. While the cytokine and cellular pathways triggering arthritis are well defined, those responsible for the resolution of inflammation are incompletely characterized. Here we identified IL-9-producing type 2 innate lymphoid cells (ILC2s) as a molecular and cellular pathway that orchestrates the resolution of chronic inflammation. In mice, the absence of IL-9 impaired ILC2 proliferation, activation of regulatory T cells (Treg) and resulted in chronic arthritis with excessive cartilage destruction and bone loss. In contrast, treatment with IL-9 promoted ILC2-dependent Treg activation and effectively induced resolution of inflammation and protection of bone. Rheumatoid arthritis patients in remission demonstrated high numbers of IL-9+ ILC2s in the joints and in the circulation. Hence, fostering IL-9-mediated ILC2 activation may offer a novel therapeutic approach inducing resolution of inflammation rather than suppression of inflammatory responses. PMID:28714991

The Metallothionein-Null Phenotype Is Associated with Heightened Sensitivity to Lead Toxicity and an Inability to Form Inclusion Bodies

PubMed Central

Qu, Wei; Diwan, Bhalchandra A.; Liu, Jie; Goyer, Robert A.; Dawson, Tammy; Horton, John L.; Cherian, M. George; Waalkes, Michael P.

2002-01-01

Susceptibility to lead toxicity in MT-null mice and cells, lacking the major forms of the metallothionein (MT) gene, was compared to wild-type (WT) mice or cells. Male MT-null and WT mice received lead in the drinking water (0 to 4000 ppm) for 10 to 20 weeks. Lead did not alter body weight in any group. Unlike WT mice, lead-treated MT-null mice showed dose-related nephromegaly. In addition, after lead exposure renal function was significantly diminished in MT-null mice in comparison to WT mice. MT-null mice accumulated less renal lead than WT mice and did not form lead inclusion bodies, which were present in the kidneys of WT mice. In gene array analysis, renal glutathione S-transferases were up-regulated after lead in MT-null mice only. In vitro studies on fibroblast cell lines derived from MT-null and WT mice showed that MT-null cells were much more sensitive to lead cytotoxicity. MT-null cells accumulated less lead and formed no inclusion bodies. The MT-null phenotype seems to preclude lead-induced inclusion body formation and increases lead toxicity at the organ and cellular level despite reducing lead accumulation. This study reveals important roles for MT in chronic lead toxicity, lead accumulation, and inclusion body formation. PMID:11891201

Chronic exposure to trichloroethene causes early onset of SLE-like disease in female MRL +/+ mice

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cai Ping; Koenig, Rolf; Boor, Paul J.

2008-04-01

Trichloroethene (TCE) exacerbates the development of autoimmune responses in autoimmune-prone MRL +/+ mice. Although TCE-mediated autoimmune responses are associated with an increase in serum immunoglobulins and autoantibodies, the underlying mechanism of autoimmunity is not known. To determine the progression of TCE-mediated immunotoxicity, female MRL +/+ mice were chronically exposed to TCE through the drinking water (0.5 mg/ml of TCE) for various periods of time. Serum concentrations of antinuclear antibodies increased after 36 and 48 weeks of TCE exposure. Histopathological analyses showed lymphocyte infiltration in the livers of MRL +/+ mice exposed to TCE for 36 or 48 weeks. Lymphocyte infiltrationmore » was also apparent in the pancreas, lungs, and kidneys of mice exposed to TCE for 48 weeks. Immunoglobulin deposits in kidney glomeruli were found after 48 weeks of exposure to TCE. Our results suggest that chronic exposure to TCE promotes inflammation in the liver, pancreas, lungs, and kidneys, which may lead to SLE-like disease in MRL +/+ mice.« less

Measuring behavior in mice with chronic stress depression paradigm.

PubMed

Strekalova, Tatyana; Steinbusch, Harry W M

2010-03-17

Many studies with chronic stress, a common depression paradigm, lead to inconsistent behavioral results. We are introducing a new model of stress-induced anhedonia, which provides more reproducible induction and behavioral measuring of depressive-like phenotype in mice. First, a 4-week stress procedure induces anhedonia, defined by decreased sucrose preference, in the majority of but not all C57BL/6 mice. The remaining 30-50% non-anhedonic animals are used as an internal control for stress effects that are unrelated to anhedonia. Next, a modified sucrose test enables the detection of inter-individual differences in mice. Moreover, testing under dimmed lighting precludes behavioral artifacts caused by hyperlocomotion, a major confounding factor in stressed mice. Finally, moderation of the stress load increases the reproducibility of anhedonia induction, which otherwise is difficult to provide because of inter-batch variability in laboratory mice. We believe that our new mouse model overcomes some major difficulties in measuring behavior with chronic stress depression models. Copyright 2009 Elsevier Inc. All rights reserved.

Epidermal growth factor improves intestinal integrity and survival in murine sepsis following chronic alcohol ingestion

PubMed Central

Klingensmith, Nathan J.; Yoseph, Benyam P.; Liang, Zhe; Lyons, John D.; Burd, Eileen M.; Margoles, Lindsay M.; Koval, Michael; Ford, Mandy L.; Coopersmith, Craig M.

2016-01-01

Epidermal growth factor (EGF) is a cytoprotective protein that improves survival in preclinical models of sepsis through its beneficial effects on intestinal integrity. Alcohol use disorder worsens intestinal integrity and is associated with increased morbidity and mortality in critical illness. We sought to determine whether chronic alcohol ingestion alters the host response to systemic administration of EGF in sepsis. Six week old FVB/N mice were randomized to receive 20% alcohol or water for 12 weeks. All mice then underwent cecal ligation and puncture (CLP) to induce polymicrobial sepsis. Mice were then randomized to receive either intraperitoneal injection of EGF (150 μg/kg/day) or normal saline. Water-fed mice given EGF mice had decreased seven-day mortality compared to water-fed mice (18% vs. 55%). Alcohol-fed mice given EGF also had decreased seven day mortality compared to alcohol-fed mice (48% vs. 79%). Notably, while systemic EGF improved absolute survival to a similar degree in both water-fed and alcohol-fed mice, mortality was significantly higher in alcohol+EGF mice compared to water+EGF mice. Compared to water-fed septic mice, alcohol-fed septic mice had worsened intestinal integrity with intestinal hyperpermeability, increased intestinal epithelial apoptosis, decreased proliferation and shorter villus length. Systemic administration of EGF to septic alcohol-fed mice decreased intestinal permeability compared to septic alcohol-fed mice given vehicle, with increased levels of the tight junction mediators claudin-5 and JAM-A. Systemic administration of EGF to septic alcohol-fed mice also decreased intestinal apoptosis with an improvement in the Bax/Bcl-2 ratio. EGF also improved both crypt proliferation and villus length in septic alcohol-fed mice. EGF administration resulted in lower levels of both pro- and anti-inflammatory cytokines MCP-1, TNF and IL-10 in alcohol-fed mice. EGF is therefore effective at improving both intestinal integrity and mortality following sepsis in mice with chronic alcohol ingestion. However, the efficacy of EGF in sepsis is blunted in the setting of chronic alcohol ingestion, as intestinal integrity and mortality in alcohol-fed mice given EGF improves animals to levels seen in water-fed mice given vehicle but does not approach levels seen in water-fed mice given EGF. PMID:27465753

The Antinociceptive and Antiinflammatory Properties of 3-furan-2-yl-N-p-tolyl-acrylamide, a Positive Allosteric Modulator of α7 Nicotinic Acetylcholine Receptors in Mice

PubMed Central

Bagdas, Deniz; Targowska-Duda, Katarzyna M.; López, Jhon J.; Perez, Edwin G.; Arias, Hugo R.; Damaj, M. Imad

2016-01-01

BACKGROUND Positive allosteric modulators (PAMs) facilitate endogenous neurotransmission and/or enhance the efficacy of agonists without directly acting on the orthosteric binding sites. In this regard, selective α7 nicotinic acetylcholine receptor type II PAMs display antinociceptive activity in rodent chronic inflammatory and neuropathic pain models. This study investigates whether 3-furan-2-yl-N-p-tolyl-acrylamide (PAM-2), a new putative α7-selective type II PAM, attenuates experimental inflammatory and neuropathic pains in mice. METHODS We tested the activity of PAM-2 after intraperitoneal administration in 3 pain assays: the carrageenan-induced inflammatory pain, the complete Freund adjuvant induced inflammatory pain, and the chronic constriction injury–induced neuropathic pain in mice. We also tested whether PAM-2 enhanced the effects of the selective α7 agonist choline in the mouse carrageenan test given intrathecally. Because the experience of pain has both sensory and affective dimensions, we also evaluated the effects of PAM-2 on acetic acid–induced aversion by using the conditioned place aversion test. RESULTS We observed that systemic administration of PAM-2 significantly reversed mechanical allodynia and thermal hyperalgesia in inflammatory and neuropathic pain models in a dose- and time-dependent manner without motor impairment. In addition, by attenuating the paw edema in inflammatory models, PAM-2 showed antiinflammatory properties. The antinociceptive effect of PAM-2 was inhibited by the selective competitive antagonist methyllycaconitine, indicating that the effect is mediated by α7 nicotinic acetylcholine receptors. Furthermore, PAM-2 enhanced the antiallodynic and antiinflammatory effects of choline, a selective α7 agonist, in the mouse carrageenan test. PAM-2 was also effective in reducing acetic acid induced aversion in the conditioned place aversion assay. CONCLUSIONS These findings suggest that the administration of PAM-2, a new α7-selective type II PAM, reduces the neuropathic and inflammatory pain sensory and affective behaviors in the mouse. Thus, this drug may have therapeutic applications in the treatment and management of chronic pain. PMID:26280585

Altered Protein Expression in the Ileum of Mice Associated with the Development of Chronic Infections with Echinostoma caproni (Trematoda)

PubMed Central

Cortés, Alba; Sotillo, Javier; Muñoz-Antoli, Carla; Fried, Bernard; Esteban, J. Guillermo; Toledo, Rafael

2015-01-01

Background Echinostoma caproni (Trematoda: Echinostomatidae) is an intestinal trematode that has been extensively used as experimental model to investigate the factors determining the expulsion of intestinal helminths or, in contrast, the development of chronic infections. Herein, we analyze the changes in protein expression induced by E. caproni infection in ICR mice, a host of high compatibility in which the parasites develop chronic infections. Methodology/Principal Findings To determine the changes in protein expression, a two-dimensional DIGE approach using protein extracts from the intestine of naïve and infected mice was employed; and spots showing significant differential expression were analyzed by mass spectrometry. A total of 37 spots were identified differentially expressed in infected mice (10 were found to be over-expressed and 27 down-regulated). These proteins were related to the restoration of the intestinal epithelium and the control of homeostatic dysregulation, concomitantly with mitochondrial and cytoskeletal proteins among others. Conclusion/Significance Our results suggests that changes in these processes in the ileal epithelium of ICR mice may facilitate the establishment of the parasite and the development of chronic infections. These results may serve to explain the factors determining the development of chronicity in intestinal helminth infection. PMID:26390031

Chronic alcohol consumption enhances iNKT cell maturation and activation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Hui, E-mail: hzhang@wsu.edu; Zhang, Faya; Zhu, Zhaohui

Alcohol consumption exhibits diverse effects on different types of immune cells. NKT cells are a unique T cell population and play important immunoregulatory roles in different types of immune responses. The effects of chronic alcohol consumption on NKT cells remain to be elucidated. Using a mouse model of chronic alcohol consumption, we found that alcohol increases the percentage of NKT cells, especially iNKT cells in the thymus and liver, but not in the spleen or blood. Alcohol consumption decreases the percentage of NK1.1{sup −} iNKT cells in the total iNKT cell population in all of the tissues and organs examined.more » In the thymus, alcohol consumption increases the number of NK1.1{sup +}CD44{sup hi} mature iNKT cells but does not alter the number of NK1.1{sup −} immature iNKT cells. A BrdU incorporation assay shows that alcohol consumption increases the proliferation of thymic NK1.1{sup −} iNKT cells, especially the NK1.1{sup −}CD44{sup lo} Stage I iNKT cells. The percentage of NKG2A{sup +} iNKT cells increases in all of the tissues and organs examined; whereas CXCR3{sup +} iNKT cells only increases in the thymus of alcohol-consuming mice. Chronic alcohol consumption increases the percentage of IFN-γ-producing iNKT cells and increases the blood concentration of IFN-γ and IL-12 after in vivo α-galactosylceramide (αGalCer) stimulation. Consistent with the increased cytokine production, the in vivo activation of iNKT cells also enhances the activation of dendritic cells (DC) and NK, B, and T cells in the alcohol-consuming mice. Taken together the data indicate that chronic alcohol consumption enhances iNKT cell maturation and activation, which favors the Th1 immune response. - Highlights: • Chronic alcohol consumption increases iNKT cells in the thymus and liver • Chronic alcohol consumption enhances thymic Stage I iNKT cell proliferation • Chronic alcohol consumption enhances iNKT cell maturation in thymus and periphery • Chronic alcohol consumption induces Th1 immune response upon iNKT cell in vivo activation.« less

The effects of a standardized Acanthopanax koreanum extract on stress-induced behavioral alterations in mice.

PubMed

Jung, Jun Man; Park, Se Jin; Lee, Young Woo; Lee, Hyung Eun; Hong, Sung In; Lew, Jae Hwan; Hong, Eunyoung; Shim, Jae Seok; Cheong, Jae Hoon; Ryu, Jong Hoon

2013-07-30

The roots and stem bark of Acanthopanax koreanum Nakai (Araliaceae), a well-known herbal medicine in Jeju Island, Korea, has been used as a tonic agent in treating stress-related states. Despite its popular application, the anti-anxiety or anti-depressive action of Acanthopanax koreanum is not yet known. This study aimed to determine the effects of Acanthopanax koreanum on stress-induced behavioral alterations such as anxiety and depression. Mice in the acute stress group were exposed to immobilization stress for 2h followed by electric foot shocks (0.5 mA in 1 s duration with a 10 s inter-shock interval) for 2 min, while sub-chronically stressed mice were exposed to these stresses for 2 weeks, once per day. 70% ethanolic extract of Acanthopanax koreanum (EEAK) (25, 50, 100, or 200 mg/kg) was administered once or sub-chronically (for 2 weeks) 1h prior to stress induction. Anxiety- or depression-like behavioral changes were evaluated using the elevated plus-maze (EPM) test and the forced swimming test (FST) a day after the final stress induction. Corticosterone levels and spleen weight were measured after conducting all the behavioral assays. The numbers of BrdU- or DCX-immunopositive cells in the hippocampal region of sub-chronically stressed mice were measured 2 days after EEAK treatment. The percentage of time spent in the open arms was decreased in both the acutely and chronically stressed mice. In the FST, the immobility time was increased by only chronic stress, but not by acute stress. Acute or sub-chronic administration of EEAK significantly prevented the anxiety- or depression-like behavioral changes caused by stress. EEAK also attenuated stress-induced decrease and increase of spleen weight and corticosterone levels, respectively. Furthermore, the sub-chronic administration of EEAK (100 or 200 mg/kg, for 2 weeks) increased the number of BrdU-, doublecortin-, and neuropeptide Y-positive cells in the hippocampal region of the sub-chronically stressed mice. EEAK attenuated the behavioral and biochemical changes in acute or sub-chronic stressed mice. These results suggest the therapeutic potential of Acanthopanax koreanum for the treatment of stress-related neuropsychiatric disorders including anxiety disorders or major depressive disorder. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Effects of a treatment with Se-rich rice flour high in resistant starch on enteric dysbiosis and chronic inflammation in diabetic ICR mice.

PubMed

Yuan, Huaibo; Wang, Wenjuan; Chen, Deyi; Zhu, Xiping; Meng, Lina

2017-05-01

Enteric dysbiosis is associated with chronic inflammation and interacts with obesity and insulin resistance. Obesity and diabetes are induced in ICR (Institute of Cancer Research) mice fed a high-fat diet and administered a streptozocin injection. These mice were treated with normal rice (NR), normal rice with a high resistant starch content (NRRS) or Se-rich rice (selenium-enriched rice) with a high resistant starch content (SRRS). Faecal cell counts of Bifidobacterium, Lactobacillus and Enterococcus were significantly higher in SRRS-treated mice than in diabetic controls, while Enterobacter cloacae were lower. Similar results were also found in NRRS-treated mice. In contrast, no significant difference was found between NR-treated and diabetic control groups. The treatments with SRRS and NRRS reduced the faecal pH values of the diabetic mice. Regarding the inflammatory factor levels, lower levels of serum C-reactive protein (CRP), tumour necrosis factor-α (TNF-α), interleukin-6 (IL-6), nuclear factor-k-gene binding (NF-κB) and leptin (LEP) and higher adiponutrin (ADPN) levels were found in the SRRS and NRRS-treated mice compared with the diabetic and NR-treated mice. In addition, the CRP, IL-6 and NF-κB levels in the SRRS-treated mice were significantly reduced compared with those observed in the NRRS-treated mice. The reverse transcription-PCR (RT-PCR) results showed that the SRRS and NRRS-treated mice presented higher expression levels of orphan G protein-coupled receptor 41 (GPR41) and orphan G protein-coupled receptor 43 (GPR43) proteins compared with diabetic mice and NR-treated mice. These results indicate that treatments with rice high in RS exert beneficial effects by improving enteric dysbiosis and chronic inflammation. In addition, selenium and RS may exert synergistic effects on chronic inflammation. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

Chronic social stress leads to altered sleep homeostasis in mice.

PubMed

Olini, Nadja; Rothfuchs, Iru; Azzinnari, Damiano; Pryce, Christopher R; Kurth, Salome; Huber, Reto

2017-06-01

Disturbed sleep and altered sleep homeostasis are core features of many psychiatric disorders such as depression. Chronic uncontrollable stress is considered an important factor in the development of depression, but little is known on how chronic stress affects sleep regulation and sleep homeostasis. We therefore examined the effects of chronic social stress (CSS) on sleep regulation in mice. Adult male C57BL/6 mice were implanted for electrocortical recordings (ECoG) and underwent either a 10-day CSS protocol or control handling (CON). Subsequently, ECoG was assessed across a 24-h post-stress baseline, followed by a 4-h sleep deprivation, and then a 20-h recovery period. After sleep deprivation, CSS mice showed a blunted increase in sleep pressure compared to CON mice, as measured using slow wave activity (SWA, electroencephalographic power between 1-4Hz) during non-rapid eye movement (NREM) sleep. Vigilance states did not differ between CSS and CON mice during post-stress baseline, sleep deprivation or recovery, with the exception of CSS mice exhibiting increased REM sleep during recovery sleep. Behavior during sleep deprivation was not affected by CSS. Our data provide evidence that CSS alters the homeostatic regulation of sleep SWA in mice. In contrast to acute social stress, which results in a faster SWA build-up, CSS decelerates the homeostatic build up. These findings are discussed in relation to the causal contribution of stress-induced sleep disturbance to depression. Copyright © 2017 Elsevier B.V. All rights reserved.

Nrf2-Mediated Neuroprotection Against Recurrent Hypoglycemia Is Insufficient to Prevent Cognitive Impairment in a Rodent Model of Type 1 Diabetes.

PubMed

McNeilly, Alison D; Gallagher, Jennifer R; Dinkova-Kostova, Albena T; Hayes, John D; Sharkey, John; Ashford, Michael L J; McCrimmon, Rory J

2016-10-01

It remains uncertain whether recurrent nonsevere hypoglycemia (Hypo) results in long-term cognitive impairment in type 1 diabetes (T1D). This study tested the hypothesis that specifically in the T1D state, Hypo leads to cognitive impairment via a pathological response to oxidative stress. Wild-type (Control) and nuclear factor-erythroid 2 p45-related factor 2 (Nrf2) null mice were studied. Eight groups of mice (Control and Nrf2(-/-) ± T1D and ± Hypo) were subject to recurrent, twice-weekly, insulin or saline injections over 4 weeks, after which cognitive function was assessed and brain tissue analyzed. Recurrent moderate hypoglycemia in T1D, but not Control, mice significantly impaired cognitive performance, and this was associated with hippocampal oxidative damage and inflammation despite an enhanced expression of Nrf2 and its target genes Hmox1 and Nqo1 In Nrf2(-/-) mice, both T1D and Hypo independently resulted in impaired cognitive performance, and this was associated with oxidative cell damage and marked inflammation. Together, these data suggest that Hypo induces an Nrf2-dependent antioxidant response in the hippocampus, which counteracts oxidative damage. However, in T1D, this neuroprotective mechanism is insufficient to prevent neuronal oxidative damage, resulting in chronic deficits in working and long-term memory. © 2016 by the American Diabetes Association.

Combinatorial RNA Interference Therapy Prevents Selection of Pre-existing HBV Variants in Human Liver Chimeric Mice

PubMed Central

Shih, Yao-Ming; Sun, Cheng-Pu; Chou, Hui-Hsien; Wu, Tzu-Hui; Chen, Chun-Chi; Wu, Ping-Yi; Enya Chen, Yu-Chen; Bissig, Karl-Dimiter; Tao, Mi-Hua

2015-01-01

Selection of escape mutants with mutations within the target sequence could abolish the antiviral RNA interference activity. Here, we investigated the impact of a pre-existing shRNA-resistant HBV variant on the efficacy of shRNA therapy. We previously identified a highly potent shRNA, S1, which, when delivered by an adeno-associated viral vector, effectively inhibits HBV replication in HBV transgenic mice. We applied the “PICKY” software to systemically screen the HBV genome, then used hydrodynamic transfection and HBV transgenic mice to identify additional six highly potent shRNAs. Human liver chimeric mice were infected with a mixture of wild-type and T472C HBV, a S1-resistant HBV variant, and then treated with a single or combined shRNAs. The presence of T472C mutant compromised the therapeutic efficacy of S1 and resulted in replacement of serum wild-type HBV by T472C HBV. In contrast, combinatorial therapy using S1 and P28, one of six potent shRNAs, markedly reduced titers for both wild-type and T472C HBV. Interestingly, treatment with P28 alone led to the emergence of escape mutants with mutations in the P28 target region. Our results demonstrate that combinatorial RNAi therapy can minimize the escape of resistant viral mutants in chronic HBV patients. PMID:26482836

Chronic Inhibition of Dopamine β-Hydroxylase Facilitates Behavioral Responses to Cocaine in Mice

PubMed Central

Gaval-Cruz, Meriem; Liles, Larry Cameron; Iuvone, Paul Michael; Weinshenker, David

2012-01-01

The anti-alcoholism medication, disulfiram (Antabuse), decreases cocaine use in humans regardless of concurrent alcohol consumption and facilitates cocaine sensitization in rats, but the functional targets are unknown. Disulfiram inhibits dopamine β-hydroxylase (DBH), the enzyme that converts dopamine (DA) to norepinephrine (NE) in noradrenergic neurons. The goal of this study was to test the effects of chronic genetic or pharmacological DBH inhibition on behavioral responses to cocaine using DBH knockout (Dbh −/−) mice, disulfiram, and the selective DBH inhibitor, nepicastat. Locomotor activity was measured in control (Dbh +/−) and Dbh −/− mice during a 5 day regimen of saline+saline, disulfiram+saline, nepicastat+saline, saline+cocaine, disulfiram+cocaine, or nepicastat+cocaine. After a 10 day withdrawal period, all groups were administered cocaine, and locomotor activity and stereotypy were measured. Drug-naïve Dbh −/− mice were hypersensitive to cocaine-induced locomotion and resembled cocaine-sensitized Dbh +/− mice. Chronic disulfiram administration facilitated cocaine-induced locomotion in some mice and induced stereotypy in others during the development of sensitization, while cocaine-induced stereotypy was evident in all nepicastat-treated mice. Cocaine-induced stereotypy was profoundly increased in the disulfiram+cocaine, nepicastat+cocaine, and nepicastat+saline groups upon cocaine challenge after withdrawal in Dbh +/− mice. Disulfiram or nepicastat treatment had no effect on behavioral responses to cocaine in Dbh −/− mice. These results demonstrate that chronic DBH inhibition facilitates behavioral responses to cocaine, although different methods of inhibition (genetic vs. non-selective inhibitor vs. selective inhibitor) enhance qualitatively different cocaine-induced behaviors. PMID:23209785

Impaired adipogenesis in adipose tissue associated with hepatic lipid deposition induced by chronic inflammation in mice with chew diet.

PubMed

Yang, Shumin; Zhang, Wenlong; Zhen, Qianna; Gao, Rufei; Du, Tingting; Xiao, Xiaoqiu; Wang, Zhihong; Ge, Qian; Hu, Jinbo; Ye, Peng; Zhu, Qibo; Li, Qifu

2015-09-15

Chronic inflammation might be associated with hepatic lipid deposition independent of overnutrition. However, the mechanism is not fully understood. In this study, we investigate if impaired adipogenesis in adipose tissue is associated with hepatic lipid deposition induced by chronic inflammation in mice with chew diet. Casein injection in C57BL/6J mice was given every other day to induce chronic inflammation. All mice were sacrificed after 18weeks of injections. The serum, liver and adipose tissue were collected for analysis. Real-time polymerase chain reaction and western blotting were used to examine the gene and protein expressions of molecules involved in hepatic lipid metabolism and adipose adipogenesis. Casein injection elevated serum levels of insulin, free fatty acid (FFA) and proinflammatory factors. The gene expression of proinflammatory factors of adipose tissue and the liver also increased in the casein group as compared with the control group. Chronic inflammation up-regulated the hepatic expression of fatty acid translocase (CD36) and down-regulated microsomal triacylglycerol transfer protein (MTP), carnitine palmitoyltransferase 1a (CPT1a) and acyl-coenzyme a oxidase 1 (ACOX1). Meanwhile, chronic inflammation not only diminished the size of adipocytes, but also down-regulated the expression of peroxisome proliferator-activated receptor γ (PPARγ) and CCAAT/enhancer binding proteinα (C/EBPα), both indicating an impaired adipogenesis. Besides disturbed lipid metabolism in the liver per se, impaired adipogenesis in the adipose tissue might also be associated with hepatic lipid deposition induced by chronic inflammation in mice with chew diet. Copyright © 2015 Elsevier Inc. All rights reserved.

Olfactory ability and object memory in three mouse models of varying body weight, metabolic hormones, and adiposity

PubMed Central

Tucker, Kristal R.; Godbey, Steven J.; Thiebaud, Nicolas; Fadool, Debra Ann

2012-01-01

Physiological and nutritional state can modify sensory ability and perception through hormone signaling. Obesity and related metabolic disorders present a chronic imbalance in hormonal signaling that could impact sensory systems. In the olfactory system, external chemical cues are transduced into electrical signals to encode information. It is becoming evident that this system can also detect internal chemical cues in the form of molecules of energy homeostasis and endocrine hormones, whereby neurons of the olfactory system are modulated to change animal behavior towards olfactory cues. We hypothesized that chronic imbalance in hormonal signaling and energy homeostasis due to obesity would thereby disrupt olfactory behaviors in mice. To test this idea, we utilized three mouse models of varying body weight, metabolic hormones, and visceral adiposity – 1) C57BL6/J mice maintained on a condensed-milk based, moderately high-fat diet (MHF) of 32% fat for 6 months as the diet-induced obesity model, 2) an obesity-resistant, lean line of mice due to a gene-targeted deletion of a voltage-dependent potassium channel (Kv1.3-null), and 3) a genetic model of obesity as a result of a gene-targeted deletion of the melanocortin 4 receptor (MC4R-null). Diet-induced obese (DIO) mice failed to find fatty-scented hidden peanut butter cracker, based solely on olfactory cues, any faster than an unscented hidden marble, initially suggesting general anosmia. However, when these DIO mice were challenged to find a sweet-scented hidden chocolate candy, they had no difficulty. Furthermore, DIO mice were able to discriminate between fatty acids that differ by a single double bond and are components of the MHF diet (linoleic and oleic acid) in a habituation-dishabituation paradigm. Obesity-resistant, Kv1.3-null mice exhibited no change in scented object retrieval when placed on the MHF-diet, nor did they perform differently than wild-type mice in parallel habituation-dishabituation paradigms of fatty food-related odor components. Genetically obese, MC4R-null mice successfully found hidden scented objects, but did so more slowly than lean, wild-type mice, in an object-dependent fashion. In habituation-dishabituation trials of general odorants, MC4R-null mice failed to discriminate a novel odor, but were able to distinguish two fatty acids. Object memory recognition tests for short- and long-term memory retention demonstrated that maintenance on the MHF diet did not modify ability to perform these tasks independent of whether mice became obese or were resistant to weight gain (Kv1.3-null), however, the genetically predisposed obese mice (MC4R-null) failed the long-term object memory recognition performed at 24 hours. These results demonstrate that even though both the DIO mice and genetically predisposed obese mice are obese, they vary in the degree to which they exhibit behavioral deficits in odor detection, odor discrimination, and long-term memory. PMID:22995978

Epidermal Growth Factor Improves Intestinal Integrity and Survival in Murine Sepsis Following Chronic Alcohol Ingestion.

PubMed

Klingensmith, Nathan J; Yoseph, Benyam P; Liang, Zhe; Lyons, John D; Burd, Eileen M; Margoles, Lindsay M; Koval, Michael; Ford, Mandy L; Coopersmith, Craig M

2017-02-01

Epidermal growth factor (EGF) is a cytoprotective protein that improves survival in preclinical models of sepsis through its beneficial effects on intestinal integrity. Alcohol use disorder worsens intestinal integrity and is associated with increased morbidity and mortality in critical illness. We sought to determine whether chronic alcohol ingestion alters the host response to systemic administration of EGF in sepsis. Six-week-old FVB/N mice were randomized to receive 20% alcohol or water for 12 weeks. All mice then underwent cecal ligation and puncture to induce polymicrobial sepsis. Mice were then randomized to receive either intraperitoneal injection of EGF (150 μg/kg/day) or normal saline. Water-fed mice given EGF had decreased 7-day mortality compared with water-fed mice (18% vs. 55%). Alcohol-fed mice given EGF also had decreased 7-day mortality compared with alcohol-fed mice (48% vs. 79%). Notably, while systemic EGF improved absolute survival to a similar degree in both water-fed and alcohol-fed mice, mortality was significantly higher in alcohol+EGF mice compared with water+EGF mice. Compared with water-fed septic mice, alcohol-fed septic mice had worsened intestinal integrity with intestinal hyperpermeability, increased intestinal epithelial apoptosis, decreased proliferation and shorter villus length. Systemic administration of EGF to septic alcohol-fed mice decreased intestinal permeability compared with septic alcohol-fed mice given vehicle, with increased levels of the tight junction mediators claudin-5 and JAM-A. Systemic administration of EGF to septic alcohol-fed mice also decreased intestinal apoptosis with an improvement in the Bax/Bcl-2 ratio. EGF also improved both crypt proliferation and villus length in septic alcohol-fed mice. EGF administration resulted in lower levels of both pro- and anti-inflammatory cytokines monocyte chemoattractant protein-1, tumor necrosis factor, and interleukin 10 in alcohol-fed mice. EGF is therefore effective at improving both intestinal integrity and mortality following sepsis in mice with chronic alcohol ingestion. However, the efficacy of EGF in sepsis is blunted in the setting of chronic alcohol ingestion, as intestinal integrity and mortality in alcohol-fed mice given EGF improves animals to levels seen in water-fed mice given vehicle but does not approach levels seen in water-fed mice given EGF.

Epac2a-null mice exhibit obesity-prone nature more susceptible to leptin resistance

PubMed Central

Hwang, M; Go, Y; Park, J-H; Shin, S-K; Song, S E; Oh, B-C; Im, S-S; Hwang, I; Jeon, Y H; Lee, I-K; Seino, S; Song, D-K

2017-01-01

Background: The exchange protein directly activated by cAMP (Epac), which is primarily involved in cAMP signaling, has been known to be essential for controlling body energy metabolism. Epac has two isoforms: Epac1 and Epac2. The function of Epac1 on obesity was unveiled using Epac1 knockout (KO) mice. However, the role of Epac2 in obesity remains unclear. Methods: To evaluate the role of Epac2 in obesity, we used Epac2a KO mice, which is dominantly expressed in neurons and endocrine tissues. Physiological factors related to obesity were analyzed: body weight, fat mass, food intake, plasma leptin and adiponectin levels, energy expenditure, glucose tolerance, and insulin and leptin resistance. To determine the mechanism of Epac2a, mice received exogenous leptin and then hypothalamic leptin signaling was analyzed. Results: Epac2a KO mice appeared to have normal glucose tolerance and insulin sensitivity until 12 weeks of age, but an early onset increase of plasma leptin levels and decrease of plasma adiponectin levels compared with wild-type mice. Acute leptin injection revealed impaired hypothalamic leptin signaling in KO mice. Consistently, KO mice fed a high-fat diet (HFD) were significantly obese, presenting greater food intake and lower energy expenditure. HFD-fed KO mice were also characterized by greater impairment of hypothalamic leptin signaling and by weaker leptin-induced decrease in food consumption compared with HFD-fed wild-type mice. In wild-type mice, acute exogenous leptin injection or chronic HFD feeding tended to induce hypothalamic Epac2a expression. Conclusions: Considering that HFD is an inducer of hypothalamic leptin resistance and that Epac2a functions in pancreatic beta cells during demands of greater work load, hypothalamic Epac2a may have a role in facilitating leptin signaling, at least in response to higher metabolic demands. Thus, our data indicate that Epac2a is critical for preventing obesity and thus Epac2a activators may be used to manage obesity and obesity-mediated metabolic disorders. PMID:27867203

Chronic pain causes a persistent anxiety state leading to increased ethanol intake in CD1 mice.

PubMed

González-Sepúlveda, Marta; Pozo, Oscar J; Marcos, Josep; Valverde, Olga

2016-02-01

Mood disorders and chronic pain are closely linked, but limited progress has been made in understanding the role of chronic and neuropathic pain in the aetiopathogenesis of depression. To explore the pathological mechanisms that mediate the association between pain and depressive-like behaviours, we studied the time-dependent effect of neuropathic pain on the development of anxiety-like and despair behaviours in CD1 mice. We analysed behavioural data, neuroinflammation reactions and changes in neurotransmitter (glutamate and serotonin) levels in the mouse prefrontal cortex. Sciatic-operated mice displayed long-lasting anxiety-like and despair behaviours, starting 5 and 20 days after partial sciatic nerve ligation, respectively. Glutamatergic neurotransmission and IL-1β cytokine expression were enhanced in the prefrontal cortex of mice with neuropathic pain. We found no change in serotonin metabolism, cytokine IL-6 or brain-derived neurotrophic factor levels. While sciatic-operated mice exposed to intermittent ethanol intake (20% v/v) using the drinking in the dark procedure consumed higher amounts of ethanol than sham-operated mice, thermal allodynia and despair behaviour were not attenuated by ethanol consumption. Our findings reveal an association between glutamatergic neurotransmission and pain-induced mood disorders, and indicate that moderate ethanol consumption does not relieve nociceptive and depressive behaviours associated with chronic pain in mice. © The Author(s) 2015.

A mouse model for chronic pain-induced increase in ethanol consumption.

PubMed

Butler, Ryan K; Knapp, Darin J; Ulici, Veronica; Longobardi, Lara; Loeser, Richard F; Breese, George R

2017-03-01

Chronic pain conditions are often comorbid with alcohol abuse. "Self-medication" with alcohol introduces a host of problems associated with the abuse of alcohol which over time has the potential of exacerbating the painful condition. Despite the prevalence of chronic pain being associated with alcohol abuse, rodent models which mimic the comorbid conditions are lacking. In this study, we model osteoarthritis (OA) in C57BL/6J mice by surgically destabilizing the medial meniscus (DMM). Sham-operated mice served as controls. Thirteen weeks after surgery, DMM but not sham-operated mice exhibited pronounced incapacitance of the surgically manipulated hind limb compared with the nonsurgically manipulated hind limb. At this time, the mice were exposed to the 2-bottle ethanol choice, beginning with 2.5% with a gradual increasing to 20%. Compared with sham controls, DMM mice consumed more EtOH and preferred EtOH over water at the 20% EtOH concentration. Histological analysis verified that the DMM mice exhibited significant damage to the articular cartilage and osteophyte growth compared with sham controls and these measures of the severity of OA correlated with the amount of ethanol intake. Thus, the combination of the DMM model of OA with the enhanced two-bottle ethanol choice is a potential preclinical approach in mice by which the basis of the comorbid association of alcohol abuse and chronic pain conditions can be explored.

Food restriction affects Y-maze spatial recognition memory in developing mice.

PubMed

Fu, Yu; Chen, Yanmei; Li, Liane; Wang, Yumei; Kong, Xiangyang; Wang, Jianhong

2017-08-01

The ambiguous effects of food restriction (FR) on cognition in rodents have been mostly explored in the aged brain by a variety of paradigms, in which either rewards or punishments are involved. This study aims to examine the effects of chronic and acute FR with varying intensities on spatial recognition memory in developing mice. We have used a Y-maze task that is based on the innate tendency of rodents to explore novel environments. In chronic FR, mice had 70-30% chow of control for seven weeks. In acute FR, mice were food restricted for 12-48h before the tests. We found that chronic FR had no effect on the preference of mice for novelty in the Y-maze, but severe FR (50-30% of control) caused impairment on spatial recognition memory. The impairment significantly correlated with the slow weight growth induced by FR. Acute FR also did not affect the novelty preference of mice, but either improved or impaired the memory retention. These data suggest chronic FR impairs Y-maze spatial recognition memory in developing mice depending on FR intensity and individual tolerability of the FR. Moreover, acute FR exerts diverse effects on the memory, either positive or negative. Our findings have revealed new insights on the effects of FR on spatial recognition memory in developing animals. Copyright © 2017 ISDN. Published by Elsevier Ltd. All rights reserved.

Effects of Chronic Exposure to Ultrasound of Alternating Frequencies on the Levels of Aggression and Anxiety in CBA and BALB/c mice.

PubMed

Pavlov, D A; Gorlova, A V; Ushakova, V M; Zubkov, E A; Morozova, A Yu; Inozemtsev, A N; Chekhonin, V P

2017-08-01

Stress-induced changes in the behavior of CBA and BALB/c mice were studied after 3-week ultrasound exposure (22-45 kHz). The mice of both lines demonstrated increased aggression in the resident-intruder and social interest paradigms and reduced number of social interactions in the social interest test. Elevated plus maze test showed a decrease in anxiety level in CBA mice and an increase in this parameter in BALB/c mice. Chronic exposure to ultrasound induced an increase in aggression level in mice of both lines that was not directly related to changes in anxiety level.

Chronic consumption of distilled sugarcane spirit induces anxiolytic-like effects in mice

PubMed Central

Sena, Maria Clécia P; Nunes, Fabíola C; Stiebbe Salvadori, Mirian G S; Carvalho, Cleyton Charles D; Morais, Liana Clébia S L; Braga, Valdir A

2011-01-01

OBJECTIVE: Chronic ethanol consumption is a major public health problem throughout the world. We investigated the anxiolytic-like effects and the possible ever injury induced by the chronic consumption of ethanol or sugarcane spirit in mice. METHOD: Adult mice were exposed to a two-bottle free-choice paradigm for 6 weeks. The mice in Group A (n  =  16) had access to sugarcane spirit + distilled water, the mice in Group B (n  =  15) had access to ethanol + distilled water, and the mice in Group C (control, n  =  14) had access to distilled water + distilled water. The ethanol content in the beverages offered to Groups A and B was 2% for the first week, 5% for the second week and 10% for the remaining four weeks. At the end of the experimental period, the mice were evaluated using the elevated-plus maze and the hole-board test to assess their anxiety-related behaviors. We also determined the serum aspartate aminotransferase and alanine aminotransferase levels. RESULTS: In the elevated-plus maze, the time spent in the open arms was increased in the mice exposed to chronic ethanol (32 ± 8 vs. 7 ± 2 s, n  =  9) or sugarcane spirit (36 ± 9 vs. 7 ± 2 s, n  =  9) compared to the controls. In the hole-board test, the mice exposed to ethanol or sugarcane spirit displayed increases in their head-dipping frequency (16 ± 1 for the control group, 27 ± 2 for the ethanol group, and 31 ± 3 for the sugarcane-spirit group; n  =  9 for each group). In addition, the mice exposed to sugarcane spirit displayed an increase in the aspartate aminotransferase / alanine aminotransferase ratio compared to the ethanol group (1.29 ± 0.17 for the control group and 2.67 ± 0.17 for the sugarcane spirit group; n  =  8 for each group). CONCLUSION: The chronic consumption of sugarcane-spirit produces liver injury and anxiolytic-like effects and the possible liver injury in mice. PMID:21789394

Cerebral cortical blood flow maps are reorganized in MAOB-deficient mice

PubMed Central

Scremin, Oscar U.; Holschneider, Daniel P.; Chen, Kevin; Li, Mingen G.; Shih, Jean C.

2014-01-01

Cerebral cortical blood flow (CBF) was measured autoradiographically in conscious mice without the monoamine oxidase B (MAOB) gene (KO, n = 11) and the corresponding wild-type animals (WILD, n = 11). Subgroups of animals of each genotype received a continuous intravenous infusion over 30 min of phenylethylamine (PEA), an endogenous substrate of MAOB, (8 nmol g−1 min−1 in normal saline at a volume rate of 0.11 μl g−1 min−1) or saline at the same volume rate. Maps of relative CBF distribution showed predominance of midline motor and sensory area CBF in KO mice over WILD mice that received saline. PEA enhanced CBF in lateral frontal and piriform cortex in both KO and WILD mice. These changes may reflect a differential activation due to chronic and acute PEA elevations on motor and olfactory function, as well as on the anxiogenic effects of this amine. In addition to its effects on regional CBF distribution, PEA decreased CBF globally in KO mice (range −31% to −41% decrease from control levels) with a lesser effect in WILD mice. It is concluded that MAOB may normally regulate CBF distribution and its response to blood PEA. PMID:10095040

Acute and chronic suppression of the central ghrelin signaling system reveals a role in food anticipatory activity.

PubMed

Verhagen, Linda A W; Egecioglu, Emil; Luijendijk, Mieneke C M; Hillebrand, Jacquelien J G; Adan, Roger A H; Dickson, Suzanne L

2011-05-01

Using the rodent activity-based anorexia (ABA) model that mimics clinical features of anorexia nervosa that include food restriction-induced hyperlocomotion, we found that plasma ghrelin levels are highly associated with food anticipatory behaviour, measured by running wheel activity in rats. Furthermore, we showed that ghrelin receptor (GHS-R1A) knockout mice do not anticipate food when exposed to the ABA model, unlike their wild type littermate controls. Likewise, food anticipatory activity in the ABA model was suppressed by a GHS-R1A antagonist administered either by acute central (ICV) injection to rats or by chronic peripheral treatment to mice. Interestingly, the GHS-R1A antagonist did not alter food intake in any of these models. Therefore, we hypothesize that suppression of the central ghrelin signaling system via GHS-R1A provides an interesting therapeutic target to treat hyperactivity in patients suffering from anorexia nervosa. Copyright © 2010. Published by Elsevier B.V.

Stress induces pain transition by potentiation of AMPA receptor phosphorylation.

PubMed

Li, Changsheng; Yang, Ya; Liu, Sufang; Fang, Huaqiang; Zhang, Yong; Furmanski, Orion; Skinner, John; Xing, Ying; Johns, Roger A; Huganir, Richard L; Tao, Feng

2014-10-08

Chronic postsurgical pain is a serious issue in clinical practice. After surgery, patients experience ongoing pain or become sensitive to incident, normally nonpainful stimulation. The intensity and duration of postsurgical pain vary. However, it is unclear how the transition from acute to chronic pain occurs. Here we showed that social defeat stress enhanced plantar incision-induced AMPA receptor GluA1 phosphorylation at the Ser831 site in the spinal cord and greatly prolonged plantar incision-induced pain. Interestingly, targeted mutation of the GluA1 phosphorylation site Ser831 significantly inhibited stress-induced prolongation of incisional pain. In addition, stress hormones enhanced GluA1 phosphorylation and AMPA receptor-mediated electrical activity in the spinal cord. Subthreshold stimulation induced spinal long-term potentiation in GluA1 phosphomimetic mutant mice, but not in wild-type mice. Therefore, spinal AMPA receptor phosphorylation contributes to the mechanisms underlying stress-induced pain transition. Copyright © 2014 the authors 0270-6474/14/3413737-10$15.00/0.

A soft, transparent, freely accessible cranial window for chronic imaging and electrophysiology

PubMed Central

Heo, Chaejeong; Park, Hyejin; Kim, Yong-Tae; Baeg, Eunha; Kim, Yong Ho; Kim, Seong-Gi; Suh, Minah

2016-01-01

Chronic in vivo imaging and electrophysiology are important for better understanding of neural functions and circuits. We introduce the new cranial window using soft, penetrable, elastic, and transparent, silicone-based polydimethylsiloxane (PDMS) as a substitute for the skull and dura in both rats and mice. The PDMS can be readily tailored to any size and shape to cover large brain area. Clear and healthy cortical vasculatures were observed up to 15 weeks post-implantation. Real-time hemodynamic responses were successfully monitored during sensory stimulation. Furthermore, the PDMS window allowed for easy insertion of microelectrodes and micropipettes into the cortical tissue for electrophysiological recording and chemical injection at any location without causing any fluid leakage. Longitudinal two-photon microscopic imaging of Cx3Cr1+/− GFP transgenic mice was comparable with imaging via a conventional glass-type cranial window, even immediately following direct intracortical injection. This cranial window will facilitate direct probing and mapping for long-term brain studies. PMID:27283875

Atg5- and Atg7-dependent autophagy in dopaminergic neurons regulates cellular and behavioral responses to morphine.

PubMed

Su, Ling-Yan; Luo, Rongcan; Liu, Qianjin; Su, Jing-Ran; Yang, Lu-Xiu; Ding, Yu-Qiang; Xu, Lin; Yao, Yong-Gang

2017-09-02

The molecular basis of chronic morphine exposure remains unknown. In this study, we hypothesized that macroautophagy/autophagy of dopaminergic neurons would mediate the alterations of neuronal dendritic morphology and behavioral responses induced by morphine. Chronic morphine exposure caused Atg5 (autophagy-related 5)- and Atg7 (autophagy-related 7)-dependent and dopaminergic neuron-specific autophagy resulting in decreased neuron dendritic spines and the onset of addictive behaviors. In cultured primary midbrain neurons, morphine treatment significantly reduced total dendritic length and complexity, and this effect could be reversed by knockdown of Atg5 or Atg7. Mice deficient for Atg5 or Atg7 specifically in the dopaminergic neurons were less sensitive to developing a morphine reward response, behavioral sensitization, analgesic tolerance and physical dependence compared to wild-type mice. Taken together, our findings suggested that the Atg5- and Atg7-dependent autophagy of dopaminergic neurons contributed to cellular and behavioral responses to morphine and may have implications for the future treatment of drug addiction.

STAT3 and STAT1 mediate IL-11–dependent and inflammation-associated gastric tumorigenesis in gp130 receptor mutant mice

PubMed Central

Ernst, Matthias; Najdovska, Meri; Grail, Dianne; Lundgren-May, Therese; Buchert, Michael; Tye, Hazel; Matthews, Vance B.; Armes, Jane; Bhathal, Prithi S.; Hughes, Norman R.; Marcusson, Eric G.; Karras, James G.; Na, Songqing; Sedgwick, Jonathon D.; Hertzog, Paul J.; Jenkins, Brendan J.

2008-01-01

Deregulated activation of STAT3 is frequently associated with many human hematological and epithelial malignancies, including gastric cancer. While exaggerated STAT3 signaling facilitates an antiapoptotic, proangiogenic, and proproliferative environment for neoplastic cells, the molecular mechanisms leading to STAT3 hyperactivation remain poorly understood. Using the gp130Y757F/Y757F mouse model of gastric cancer, which carries a mutated gp130 cytokine receptor signaling subunit that cannot bind the negative regulator of cytokine signaling SOCS3 and is characterized by hyperactivation of the signaling molecules STAT1 and STAT3, we have provided genetic evidence that IL-11 promotes chronic gastric inflammation and associated tumorigenesis. Expression of IL-11 was increased in gastric tumors in gp130Y757F/Y757F mice, when compared with unaffected gastric tissue in wild-type mice, while gp130Y757F/Y757F mice lacking the IL-11 ligand–binding receptor subunit (IL-11Rα) showed normal gastric STAT3 activation and IL-11 expression and failed to develop gastric tumors. Furthermore, reducing STAT3 activity in gp130Y757F/Y757F mice, either genetically or by therapeutic administration of STAT3 antisense oligonucleotides, normalized gastric IL-11 expression and alleviated gastric tumor burden. Surprisingly, the genetic reduction of STAT1 expression also reduced gastric tumorigenesis in gp130Y757F/Y757F mice and coincided with reduced gastric inflammation and IL-11 expression. Collectively, our data have identified IL-11 as a crucial cytokine promoting chronic gastric inflammation and associated tumorigenesis mediated by excessive activation of STAT3 and STAT1. PMID:18431520

Acute and chronic in vivo effects of exposure to nicotine and propylene glycol from an E-cigarette on mucociliary clearance in a murine model

PubMed Central

Laube, Beth L.; Afshar-Mohajer, Nima; Koehler, Kirsten; Chen, Gang; Lazarus, Philip; Collaco, Joseph M.; McGrath-Morrow, Sharon A.

2017-01-01

Objective To determine the effect of an acute (1 week) and chronic (3 weeks) exposure to E-cigarette (E-cig) emissions on mucociliary clearance (MCC) in murine lungs. Methods C57BL/6 male mice (age 10.5 ±2.4 weeks) were exposed for 20min/day to E-cigarette aerosol generated by a Joyetech 510-T® E-cig containing either 0% nicotine (N)/propylene glycol (PG) for 1 week (n = 6), or 3 weeks (n = 9), or 2.4% N/PG for one week (n = 6), or 3 weeks (n = 9), followed by measurement of MCC. Control mice (n = 15) were not exposed to PG alone, or N/PG. MCC was assessed by gamma camera following aspiration of 99mtechnetium aerosol and was expressed as the amount of radioactivity removed from both lungs over 6 hours (MCC6hrs). Venous blood was assayed for cotinine levels in control mice and in mice exposed for 3-weeks to PG alone and N/PG. Results MCC6hrs in control mice and in mice acutely exposed to PG alone and N/PG was similar, averaging (±1 standard deviation) 8.6±5.2%, 7.5±2.8% and 11.2±5.9%, respectively. In contrast, chronic exposure to PG alone stimulated MCC6hrs (17.2 ±8.0)% and this stimulation was significantly blunted following chronic exposure to N/PG (8.7 ±4.6)% (p < .05). Serum cotinine levels were <0.5ng/ml in control mice and in mice exposed to PG alone, whereas, N/PG exposed mice averaged 14.6 ± 12.0 ng/ml. Conclusions In this murine model, a chronic, daily, 20 min-exposure to N/PG, but not an acute exposure, slowed MCC, compared to exposure to PG alone and led to systemic absorption of nicotine. PMID:28651446

Chronic voluntary alcohol consumption results in tolerance to sedative/hypnotic and hypothermic effects of alcohol in hybrid mice

PubMed Central

Ozburn, Angela Renee; Harris, R. Adron; Blednov, Yuri A.

2013-01-01

The continuous two bottle choice test is the most common measure of alcohol consumption but there is remarkably little information about the development of tolerance or dependence with this procedure. We showed that C57BL/6JxFVB/NJ and FVB/NJxC57BL/6J F1 hybrid mice demonstrate greater preference for and consumption of alcohol than either parental strain. In order to test the ability of this genetic model of high alcohol consumption to produce neuroadaptation, we examined development of alcohol tolerance and dependence after chronic self-administration using a continuous access two-bottle choice paradigm. Ethanol-experienced mice stably consumed about 16–18 g/kg/day of ethanol. Ethanol-induced withdrawal severity was assessed (after 59 days of drinking) by scoring handling-induced convulsions; withdrawal severity was minimal and did not differ between ethanol-experienced and -naïve mice. After 71 days of drinking, the rate of ethanol clearance was similar for ethanol-experienced and -naïve mice. After 77 days of drinking, ethanol-induced loss of righting reflex (LORR) was tested daily for 5 days. Ethanol-experienced mice had a shorter duration of LORR. For both ethanol-experienced and -naïve mice, blood ethanol concentrations taken at gain of righting reflex were greater on day 5 than on day 1, indicative of tolerance. After 98 days of drinking, ethanol-induced hypothermia was assessed daily for 3 days. Both ethanol-experienced and –naïve mice developed rapid and chronic tolerance to ethanol-induced hypothermia, with significant group differences on the first day of testing. In summary, chronic, high levels of alcohol consumption in F1 hybrid mice produced rapid and chronic tolerance to both the sedative/hypnotic and hypothermic effects of ethanol; additionally, a small degree of metabolic tolerance developed. The development of tolerance supports the validity of using this model of high alcohol consumption in genetic studies of alcoholism. PMID:23313769

The locus coeruleus neurotoxin, DSP4, and/or a high sugar diet induce behavioral and biochemical alterations in wild-type mice consistent with Alzheimers related pathology.

PubMed

Choudhary, Pooja; Pacholko, Anthony G; Palaschuk, Josh; Bekar, Lane K

2018-06-03

Alzheimer's disease (AD) is the sixth leading cause of death in the United States where it is estimated that one in three seniors dies with AD or another dementia. Are modern lifestyle habits a contributing factor? Increased carbohydrate (sugar) consumption, stress and disruption of sleep patterns are quickly becoming the norm rather than the exception. Interestingly, seven months on a non-invasive high sucrose diet (20% sucrose in drinking water) has been shown to induce behavioral, metabolic and pathological changes consistent with AD in wild-type mice. As chronic stress and depression are associated with loss of locus coeruleus (LC) noradrenergic neurons and projections (source of anti-inflammatory and trophic factor control), we assessed the ability for a selective LC neurotoxin (DSP4) to accelerate and aggravate a high-sucrose mediated AD-related phenotype in wild-type mice. Male C57/Bl6 mice were divided into four groups: 1) saline injected, 2) DSP4 injected, 3) high sucrose drinking water (20%) or 4) DSP4 injected and high sucrose drinking water. We demonstrate that high sucrose consumption and DSP4 treatment promote an early-stage AD-related phenotype after only 3-4 months, as evidenced by elevated fecal corticosterone, increased despair, spatial memory deficits, increased AChE activity, elevated NO production, decreased pGSK3β and increased pTau. Combined treatment appears to accelerate and aggravate pathological processes consistent with Alzheimer disease and dementia. Developing a simple model in wild-type mice will highlight environmental and lifestyle factors that need to be addressed to slow, prevent or even reverse the rising trend in dementia patient numbers and cost.

Smoking p66Shc knocked out mice develop respiratory bronchiolitis with fibrosis but not emphysema.

PubMed

Lunghi, Benedetta; De Cunto, Giovanna; Cavarra, Eleonora; Fineschi, Silvia; Bartalesi, Barbara; Lungarella, Giuseppe; Lucattelli, Monica

2015-01-01

The adaptor protein p66Shc regulates intracellular oxidant levels through the modulation of a forkhead-related transcription factor (FOXO3a). The genetic ablation of p66Shc (p66Shc-/-) renders mice resistant to oxidative stress and p53-dependent apoptosis. We investigated whether p66Shc ablation in mice modifies lung cellular and molecular responses to cigarette smoke (CS) exposure. No differences between wild type (WT) and p66Shc-/- mice were observed in terms of inflammation and oxidant burden after acute CS exposure; however,p66Shc ablation modifies specific features of chronic inflammation induced by repeated exposure to CS. Unlike WT mice, p66Shc-/- mice did not develop emphysema, showing protection toward oxidative damage to DNA and apoptosis as revealed by a trivial 8-hydroxyguanosine staining and faint TUNEL and caspase-3 positivity on alveolar epithelial cells. Unexpectedly, CS exposure in p66Shc-/- mice resulted in respiratory bronchiolitis with fibrosis in surrounded alveoli. Respiratory bronchiolitis was characterized by peribronchiolar infiltrates of lymphocytes and histiocytes, accumulation of ageing pigmented macrophages within and around bronchioles, and peribronchiolar fibrosis. The blockage of apoptosis interferes with the macrophage "clearance" from alveolar spaces, favouring the accumulation of aging macrophages into alveoli and the progressive accumulation of iron pigment in long-lived senescent cells. The presence of areas of interstitial and alveolar fibrosis in peripheral parenchyma often accompanied the bronchiolar changes. Macrophages from smoking p66Shc-/- mice elaborate M2 cytokines (i.e., IL-4 and IL-13) and enzymes (i.e., chitinase and arginase I), which can promote TGF-beta expression, collagen deposition, and fibrosis in the surrounding areas. We demonstrate here that resistance to oxidative stress and p53-dependent apoptosis can modify tissue responses to CS caused by chronic inflammation without influencing early inflammatory response to CS exposure.

Efficacy of protocols for induction of chronic hyperthyroidism in male and female mice.

PubMed

Engels, Kathrin; Rakov, Helena; Zwanziger, Denise; Hönes, Georg Sebastian; Rehders, Maren; Brix, Klaudia; Köhrle, Josef; Möller, Lars Christian; Führer, Dagmar

2016-10-01

Protocols for induction of hyperthyroidism in mice are highly variable and mostly involve short-term thyroid hormone (TH) treatment. In addition, little is known about a possible influence of sex on experimental TH manipulation. Here we analyzed the efficacy of intraperitoneal vs. oral levothyroxine (T4) administration to induce chronic hyperthyroidism in male and female mice and asked which T4 dosing intervals are required to achieve stable organ thyrotoxicosis. T4 was administered intraperitoneally or orally over a period of 6/7 weeks. Assessment included monitoring of body weight, TH serum concentrations, and serial quantitative TH target gene expression analysis in liver and heart. Our results show that both intraperitoneal and oral T4 treatment are reliable methods for induction of chronic hyperthyroidism in mice. Thereby T4 injection intervals should not exceed 48 h and oral levothyroxine should be administered continuously during experiments and up to sacrifice to ensure a hyperthyroid organ state. Furthermore, we found a sex-dependent variation in levothyroxine-induced TH serum state, with significantly higher T4 concentrations in female mice, while expression of investigated classical TH responsive genes in liver and heart did not vary with animal's sex. In summary, our study shows that common approaches for rendering rodents thyrotoxic can also be used for induction of chronic hyperthyroidism in male and female mice. Thereby T4 dosing intervals are critical as are read-out parameters to verify a chronic thyrotoxic organ state.

l-Citrulline Protects from Kidney Damage in Type 1 Diabetic Mice

PubMed Central

Romero, Maritza J.; Yao, Lin; Sridhar, Supriya; Bhatta, Anil; Dou, Huijuan; Ramesh, Ganesan; Brands, Michael W.; Pollock, David M.; Caldwell, Ruth B.; Cederbaum, Stephen D.; Head, C. Alvin; Bagi, Zsolt; Lucas, Rudolf; Caldwell, Robert W.

2013-01-01

Rationale: Diabetic nephropathy (DN) is a major cause of end-stage renal disease, associated with endothelial dysfunction. Chronic supplementation of l-arginine (l-arg), the substrate for endothelial nitric oxide synthase (eNOS), failed to improve vascular function. l-Citrulline (l-cit) supplementation not only increases l-arg synthesis, but also inhibits cytosolic arginase I, a competitor of eNOS for the use of l-arg, in the vasculature. Aims: To investigate whether l-cit treatment reduces DN in streptozotocin (STZ)-induced type 1 diabetes (T1D) in mice and rats and to study its effects on arginase II (ArgII) function, the main renal isoform. Methods: STZ-C57BL6 mice received l-cit or vehicle supplemented in the drinking water. For comparative analysis, diabetic ArgII knock out mice and l-cit-treated STZ-rats were evaluated. Results: l-Citrulline exerted protective effects in kidneys of STZ-rats, and markedly reduced urinary albumin excretion, tubulo-interstitial fibrosis, and kidney hypertrophy, observed in untreated diabetic mice. Intriguingly, l-cit treatment was accompanied by a sustained elevation of tubular ArgII at 16 weeks and significantly enhanced plasma levels of the anti-inflammatory cytokine IL-10. Diabetic ArgII knock out mice showed greater blood urea nitrogen levels, hypertrophy, and dilated tubules than diabetic wild type (WT) mice. Despite a marked reduction in collagen deposition in ArgII knock out mice, their albuminuria was not significantly different from diabetic WT animals. l-Cit also restored nitric oxide/reactive oxygen species balance and barrier function in high glucose-treated monolayers of human glomerular endothelial cells. Moreover, l-cit also has the ability to establish an anti-inflammatory profile, characterized by increased IL-10 and reduced IL-1β and IL-12(p70) generation in the human proximal tubular cells. Conclusion: l-Citrulline supplementation established an anti-inflammatory profile and significantly preserved the nephron function during T1D. PMID:24400007

Myricetin Attenuates Depressant-Like Behavior in Mice Subjected to Repeated Restraint Stress

PubMed Central

Ma, Zegang; Wang, Guilin; Cui, Lin; Wang, Qimin

2015-01-01

Increasing evidence has shown that oxidative stress may be implicated in chronic stress-induced depression. Several flavonoids with anti-oxidative effects have been proved to be anti-depressive. Myricetin is a well-defined flavonoid with the anti-oxidative, anti-inflammatory, anti-apoptotic, and neuroprotective properties. The aim of the present study is to investigate the possible effects of chronic administration of myricetin on depressant-like behaviors in mice subjected to repeated restraint (4 h/day) for 21 days. Our results showed that myricetin administration specifically reduced the immobility time in mice exposed to chronic stress, as tested in both forced swimming test and tail suspension test. Myricetin treatment improved activities of glutathione peroxidase (GSH-PX) in the hippocampus of stressed mice. In addition, myricetin treatment decreased plasma corticosterone levels of those mice subjected to repeated restraint stress. The effects of myricetin on the brain-derived neurotrophic factor (BDNF) levels in hippocampus were also investigated. The results revealed that myricetin normalized the decreased BDNF levels in mice subjected to repeated restraint stress. These findings provided more evidence that chronic administration of myricetin improves helpless behaviors. The protective effects of myricetin might be partially mediated by an influence on BDNF levels and might be attributed to myricetin-mediated anti-oxidative stress in the hippocampus. PMID:26633366

Integrin beta 1 inhibition alleviates the chronic hyperproliferative dermatitis phenotype of SHARPIN-deficient mice.

PubMed

Peuhu, Emilia; Salomaa, Siiri I; De Franceschi, Nicola; Potter, Christopher S; Sundberg, John P; Pouwels, Jeroen

2017-01-01

SHARPIN (Shank-Associated RH Domain-Interacting Protein) is a component of the linear ubiquitin chain assembly complex (LUBAC), which enhances TNF-induced NF-κB activity. SHARPIN-deficient (Sharpincpdm/cpdm) mice display multi-organ inflammation and chronic proliferative dermatitis (cpdm) due to TNF-induced keratinocyte apoptosis. In cells, SHARPIN also inhibits integrins independently of LUBAC, but it has remained enigmatic whether elevated integrin activity levels in the dermis of Sharpincpdm/cpdm mice is due to increased integrin activity or is secondary to inflammation. In addition, the functional contribution of increased integrin activation to the Sharpincpdm/cpdm phenotype has not been investigated. Here, we find increased integrin activity in keratinocytes from Tnfr1-/- Sharpincpdm/cpdm double knockout mice, which do not display chronic inflammation or proliferative dermatitis, thus suggesting that SHARPIN indeed acts as an integrin inhibitor in vivo. In addition, we present evidence for a functional contribution of integrin activity to the Sharpincpdm/cpdm skin phenotype. Treatment with an integrin beta 1 function blocking antibody reduced epidermal hyperproliferation and epidermal thickness in Sharpincpdm/cpdm mice. Our data indicate that, while TNF-induced cell death triggers the chronic inflammation and proliferative dermatitis, absence of SHARPIN-dependent integrin inhibition exacerbates the epidermal hyperproliferation in Sharpincpdm/cpdm mice.

Chronic inflammation aggravates metabolic disorders of hepatic fatty acids in high-fat diet-induced obese mice

PubMed Central

Zhao, Lei; Zhong, Shan; Qu, Haiyang; Xie, Yunxia; Cao, Zhennan; Li, Qing; Yang, Ping; Varghese, Zac; Moorhead, John F.; Chen, Yaxi; Ruan, Xiong Z.

2015-01-01

The prevalence of nonalcoholic fatty liver disease (NAFLD) increases with increasing body mass index (BMI). However, approximately 40–50% of obese adults do not develop hepatic steatosis. The level of inflammatory biomarkers is higher in obese subjects with NAFLD compared to BMI-matched subjects without hepatic steatosis. We used a casein injection in high-fat diet (HFD)-fed C57BL/6J mice to induce inflammatory stress. Although mice on a HFD exhibited apparent phenotypes of obesity and hyperlipidemia regardless of exposure to casein injection, only the HFD+Casein mice showed increased hepatic vacuolar degeneration accompanied with elevated inflammatory cytokines in the liver and serum, compared to mice on a normal chow diet. The expression of genes related to hepatic fatty acid synthesis and oxidation were upregulated in the HFD-only mice. The casein injection further increased baseline levels of lipogenic genes and decreased the levels of oxidative genes in HFD-only mice. Inflammatory stress induced both oxidative stress and endoplasmic reticulum stress in HFD-fed mice livers. We conclude that chronic inflammation precedes hepatic steatosis by disrupting the balance between fatty acid synthesis and oxidation in the livers of HFD-fed obese mice. This mechanism may operate in obese individuals with chronic inflammation, thus making them more prone to NAFLD. PMID:25974206

Antidepressant-like effect of flaxseed secoisolariciresinol diglycoside in ovariectomized mice subjected to unpredictable chronic stress.

PubMed

Ma, Xing; Wang, Rui; Zhao, Xin; Zhang, Chong; Sun, Jiao; Li, Jianxin; Zhang, Lu; Shao, Tuo; Ruan, Lina; Chen, Liang; Xu, Ying; Pan, Jianchun

2013-03-01

Secoisolariciresinol diglycoside (SDG), a predominant lignan in flaxseed, has antioxidant activity as a dietary supplement. The purpose of the present study was to investigate the antidepressant-like effect and the possible mechanism of flaxseed SDG when the ovariectomized mice were exposed to the unpredictable chronic mild stress procedure. Chronic stress induced the increases in immobility time in mouse model of despair tests, but administration with SDG (80 and 160 mg/kg, p.o.) for 21 days inhibited these behavioral changes caused by stress in both forced swimming and tail suspension tests. These doses that affected the immobile response did not affect locomotor activity. Moreover, the changes in the serum corticosterone and adrenocorticotropic hormone (ACTH) levels were also measured to explore the SDG-associated regulation of hypothalamus-pituitary-adrenals (HPA) axis. The results indicated that the chronic stress-induced increases in the serum corticosterone and ACTH were reversed by treatment with high doses of SDG. Chronic treatment with SDG also affected the body weight of mice and IL-6, IL1β levels in the frontal cortex. In addition, chronic stress procedure induced a decrease in brain-derived neurotrophic factor (BDNF) expression in the frontal cortex of mice; while treatment with SDG reversed this reduction of BDNF. All these results provide compelling evidence that the behavioral effects of flaxseed SDG in the ovariectomized mice might be related to their modulating effects on the neuroendocrine-immune network and neurotrophin factor expression.

Fluoxetine regulates mTOR signalling in a region-dependent manner in depression-like mice

PubMed Central

Liu, Xiao-Long; Luo, Liu; Mu, Rong-Hao; Liu, Bin-Bin; Geng, Di; Liu, Qing; Yi, Li-Tao

2015-01-01

Previous studies have demonstrated that the mammalian target of rapamycin (mTOR) signaling pathway has an important role in ketamine-induced, rapid antidepressant effects despite the acute administration of fluoxetine not affecting mTOR phosphorylation in the brain. However, the effects of long-term fluoxetine treatment on mTOR modulation have not been assessed to date. In the present study, we examined whether fluoxetine, a type of commonly used antidepressant agent, alters mTOR signaling following chronic administration in different brain regions, including the frontal cortex, hippocampus, amygdala and hypothalamus. We also investigated whether fluoxetine enhanced synaptic protein levels in these regions via the activation of the mTOR signaling pathway and its downstream regulators, p70S6K and 4E-BP-1. The results indicated that chronic fluoxetine treatment attenuated the chronic, unpredictable, mild stress (CUMS)-induced mTOR phosphorylation reduction in the hippocampus and amygdala of mice but not in the frontal cortex or the hypothalamus. Moreover, the CUMS-decreased PSD-95 and synapsin I levels were reversed by fluoxetine, and these effects were blocked by rapamycin only in the hippocampus. In conclusion, our findings suggest that chronic treatment with fluoxetine can induce synaptic protein expression by activating the mTOR signaling pathway in a region-dependent manner and mainly in the hippocampus. PMID:26522512

Epigenetic modification of miR-10a regulates renal damage by targeting CREB1 in type 2 diabetes mellitus.

PubMed

Shan, Qun; Zheng, Guihong; Zhu, Aihua; Cao, Li; Lu, Jun; Wu, Dongmei; Zhang, ZiFeng; Fan, Shaohua; Sun, Chunhui; Hu, Bin; Zheng, Yuanlin

2016-09-01

Emerging evidence has shown that microRNA-mediated gene expression modulation plays a crucial role in the pathogenesis of type 2 diabetes mellitus, but the novel miRNAs involved in type 2 diabetes and its functional regulatory mechanisms still need to be determined. In this study, we assessed the role of miR-10a in extracellular matrix accumulation in the kidney of diabetic mellitus induced by combining administration of chronic high fat diet (HFD) and low dosage of streptozotocin (STZ, 35mg/kg). Here, we found that HFD/STZ administration decreased the level of microRNA (miR-10a) expression in ICR strain mice. Overexpression of miR-10a alleviated the increased ratio of urine albumin-to-creatinine (ACR) ratio of HFD/STZ mice. In contrast, knockdown of miR-10a increased the ratio of kidney ACR in naïve mice. Furthermore, cAMP response element binding protein 1 (CREB1) was validated as a target of miR-10a in vitro and in vivo. CREB1 and its downstream fibronectin (FN, extracellular matrix) were increased in HFD/STZ-treated mice, which was reversed by kidney miR-10a overexpression. The content of CREB1 and FN was increased by miR-10a knockdown in kidney of naïve mice. Furthermore, histone deacetylase 3 (HDAC3) was revealed to be increased in kidney of HFD/STZ mice, accompanied with the augmentation of ACR ratio and FN level. Knockdown of HDAC3 with siRNA significantly caused the increase of miR-10a, resulting in the decrease in CREB1 and FN expression in kidney of HFD/STZ mice. Contrarily, HDAC3 overexpression mediated by lentivirus decreased miR-10a content, and enhanced ACR value, CREB1 and FN formation in naïve mice. Collectively, these results elucidate that HDAC3/miR-10a/CREB1 serves as a new mechanism underlying kidney injury, providing potential therapeutic targets in type 2 diabetes. Copyright © 2016. Published by Elsevier Inc.

p21{sup WAF1/Cip1/Sdi1} knockout mice respond to doxorubicin with reduced cardiotoxicity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Terrand, Jerome; Xu, Beibei; Morrissy, Steve

2011-11-15

Doxorubicin (Dox) is an antineoplastic agent that can cause cardiomyopathy in humans and experimental animals. As an inducer of reactive oxygen species and a DNA damaging agent, Dox causes elevated expression of p21{sup WAF1/Cip1/Sdi1} (p21) gene. Elevated levels of p21 mRNA and p21 protein have been detected in the myocardium of mice following Dox treatment. With chronic treatment of Dox, wild type (WT) animals develop cardiomyopathy evidenced by elongated nuclei, mitochondrial swelling, myofilamental disarray, reduced cardiac output, reduced ejection fraction, reduced left ventricular contractility, and elevated expression of ANF gene. In contrast, p21 knockout (p21KO) mice did not show significantmore » changes in the same parameters in response to Dox treatment. In an effort to understand the mechanism of the resistance against Dox induced cardiomyopathy, we measured levels of antioxidant enzymes and found that p21KO mice did not contain elevated basal or inducible levels of glutathione peroxidase and catalase. Measurements of 6 circulating cytokines indicated elevation of IL-6, IL-12, IFN{gamma} and TNF{alpha} in Dox treated WT mice but not p21KO mice. Dox induced elevation of IL-6 mRNA was detected in the myocardium of WT mice but not p21KO mice. While the mechanism of the resistance against Dox induced cardiomyopathy remains unclear, lack of inflammatory response may contribute to the observed cardiac protection in p21KO mice. -- Highlights: Black-Right-Pointing-Pointer Doxorubicin induces p21 elevation in the myocardium. Black-Right-Pointing-Pointer Doxorubicin causes dilated cardiomyopathy in wild type mice. Black-Right-Pointing-Pointer p21 Knockout mice are resistant against doxorubicin induced cardiomyopathy. Black-Right-Pointing-Pointer Lack of inflammatory response correlates with the resistance in p21 knockout mice.« less

Dissociation between diurnal cycles in locomotor activity, feeding behavior and hepatic PERIOD2 expression in chronic alcohol-fed mice

PubMed Central

Zhou, Peng; Werner, John H.; Lee, Donghoon; Sheppard, Aaron D.; Liangpunsakul, Suthat; Duffield, Giles E.

2015-01-01

Chronic alcohol consumption contributes to fatty liver disease. Our studies revealed that the hepatic circadian clock is disturbed in alcohol-induced hepatic steatosis, and effects of chronic alcohol administration upon the clock itself may contribute to steatosis. We extended these findings to explore the effects of chronic alcohol treatment on daily feeding and locomotor activity patterns. Mice were chronically pair-fed ad libitum for 4 weeks using the Lieber-DeCarli liquid diet, with calorie-controlled liquid and standard chow diets as control groups. Locomotor activity, feeding activity, and real-time bioluminescence recording of PERIOD2::LUCIFERASE expression in tissue explants were measured. Mice on liquid control and chow diets exhibited normal profiles of locomotor activity, with a ratio of 22:78% day/night activity and a peak during early night. This pattern was dramatically altered in alcohol-fed mice, marked by a 49:51% ratio and the absence of a distinct peak. While chow-diet fed mice had a normal 24:76% ratio of feeding activity, with a peak in the early night, this pattern was dramatically altered in both liquid-diet groups: mice had a 43:57% ratio, and an absence of a distinct peak. Temporal differences were also observed between the two liquid-diet groups during late day. Cosinor analysis revealed a ~4-h and ~6-h shift in the alcohol-fed group feeding and locomotor activity rhythms, respectively. Analysis of hepatic PER2 expression revealed that the molecular clock in alcohol-fed and control liquid-diet mice was shifted by ~11 h and ~6 h, respectively. No differences were observed in suprachiasmatic nucleus explants, suggesting that changes in circadian phase in the liver were generated independently from the central clock. These results suggest that chronic alcohol consumption and a liquid diet can differentially modulate the daily rhythmicity of locomotor and feeding behaviors, aspects that might contribute to disturbances in the circadian timing system and development of hepatic steatosis. PMID:25960184

Increased skin barrier disruption by sodium lauryl sulfate in mice expressing a constitutively active STAT6 in T cells.

PubMed

DaSilva, Sonia C; Sahu, Ravi P; Konger, Raymond L; Perkins, Susan M; Kaplan, Mark H; Travers, Jeffrey B

2012-01-01

Atopic dermatitis (AD) is a pruritic, chronic inflammatory skin disease that affects 10-20% of children and 1-3% of adults worldwide. Recent studies have indicated that the ability of Th2 cytokines, such as interleukin-4 (IL-4) to regulate skin barrier function may be a predisposing factor for AD development. The present studies examined the ability of increased Th2 activity to affect cutaneous barrier function in vivo and epidermal thickening. Mice that express a constitutively active Signal Transducer and Activator of Transcription 6 (STAT6VT) have increased Th2 cells and a predisposition to allergic inflammation were used in these studies, they demonstrate that topical treatment with the irritant sodium lauryl sulfate (SLS) caused increased transepidermal water loss and epidermal thickening in STAT6VT mice over similarly treated wild-type mice. The proliferation marker Ki-67 was increased in the epidermis of STAT6VT compared to the wild-type mice. However, these differences do not appear to be linked to the addition of an irritant as control-treated STAT6VT skin also exhibited elevated Ki-67 levels, suggesting that the increased epidermal thickness in SLS-treated STAT6VT mice is primarily driven by epidermal cell hypertrophy rather than an increase in cellular proliferation. Our results suggest that an environment with increased Th2 cytokines results in abnormal responses to topical irritants.

Increased skin barrier disruption by sodium lauryl sulfate in mice expressing a constitutively active STAT6 in T cells

PubMed Central

DaSilva, Sonia C.; Sahu, Ravi P.; Konger, Raymond L.; Perkins, Susan M.; Kaplan, Mark H.; Travers, Jeffrey B.

2011-01-01

Atopic dermatitis (AD) is a pruritic, chronic inflammatory skin disease that affects 10–20% of children and 1–3% of adults worldwide. Recent studies have indicated that the ability of Th2 cytokines such as interleukin-4 (IL-4) to regulate skin barrier function may be a predisposing factor for AD development. The present studies examined the ability of increased Th2 activity to affect cutaneous barrier function in vivo and epidermal thickening. Mice that express a constitutively active Signal Transducer and Activator of Transcription 6 (STAT6VT) have increased Th2 cells and a predisposition to allergic inflammation were used in these studies; they demonstrate that topical treatment with the irritant sodium lauryl sulfate (SLS) caused increased transepidermal water loss and epidermal thickening in STAT6VT mice over similarly treated wild-type mice. The proliferation marker Ki-67 was increased in the epidermis of STAT6VT compared to wild-type mice. However, these differences do not appear to be linked to the addition of an irritant as control-treated STAT6VT skin also exhibited elevated Ki-67 levels, suggesting that the increased epidermal thickness in SLS-treated STAT6VT mice is primarily driven by epidermal cell hypertrophy rather than an increase in cellular proliferation. Our results suggest that an environment with increased Th2 cytokines results in abnormal responses to topical irritants. PMID:21959772

Interleukin-17-Induced Protein Lipocalin 2 Is Dispensable for Immunity to Oral Candidiasis

PubMed Central

Ferreira, Maria Carolina; Whibley, Natasha; Mamo, Anna J.; Siebenlist, Ulrich; Chan, Yvonne R.

2014-01-01

Oropharyngeal candidiasis (OPC; thrush) is an opportunistic fungal infection caused by the commensal microbe Candida albicans. Immunity to OPC is strongly dependent on CD4+ T cells, particularly those of the Th17 subset. Interleukin-17 (IL-17) deficiency in mice or humans leads to chronic mucocutaneous candidiasis, but the specific downstream mechanisms of IL-17-mediated host defense remain unclear. Lipocalin 2 (Lcn2; 24p3; neutrophil gelatinase-associated lipocalin [NGAL]) is an antimicrobial host defense factor produced in response to inflammatory cytokines, particularly IL-17. Lcn2 plays a key role in preventing iron acquisition by bacteria that use catecholate-type siderophores, and lipocalin 2−/− mice are highly susceptible to infection by Escherichia coli and Klebsiella pneumoniae. The role of Lcn2 in mediating immunity to fungi is poorly defined. Accordingly, in this study, we evaluated the role of Lcn2 in immunity to oral infection with C. albicans. Lcn2 is strongly upregulated following oral infection with C. albicans, and its expression is almost entirely abrogated in mice with defective IL-17 signaling (IL-17RA−/− or Act1−/− mice). However, Lcn2−/− mice were completely resistant to OPC, comparably to wild-type (WT) mice. Moreover, Lcn2 deficiency mediated protection from OPC induced by steroid immunosuppression. Therefore, despite its potent regulation during C. albicans infection, Lcn2 is not required for immunity to mucosal candidiasis. PMID:24343647

L-Endoglin Overexpression Increases Renal Fibrosis after Unilateral Ureteral Obstruction

PubMed Central

Arévalo, Miguel; Núñez-Gómez, Elena; Pérez-Roque, Lucía; Pericacho, Miguel; González-Núñez, María; Langa, Carmen; Martínez-Salgado, Carlos; Perez-Barriocanal, Fernando; Bernabeu, Carmelo; Lopez-Novoa, José M.

2014-01-01

Transforming growth factor-β (TGF-β) plays a pivotal role in renal fibrosis. Endoglin, a 180 KDa membrane glycoprotein, is a TGF-β co-receptor overexpressed in several models of chronic kidney disease, but its function in renal fibrosis remains uncertain. Two membrane isoforms generated by alternative splicing have been described, L-Endoglin (long) and S-Endoglin (short) that differ from each other in their cytoplasmic tails, being L-Endoglin the most abundant isoform. The aim of this study was to assess the effect of L-Endoglin overexpression in renal tubulo-interstitial fibrosis. For this purpose, a transgenic mouse which ubiquitously overexpresses human L-Endoglin (L-ENG+) was generated and unilateral ureteral obstruction (UUO) was performed in L-ENG+ mice and their wild type (WT) littermates. Obstructed kidneys from L-ENG+ mice showed higher amounts of type I collagen and fibronectin but similar levels of α-smooth muscle actin (α-SMA) than obstructed kidneys from WT mice. Smad1 and Smad3 phosphorylation were significantly higher in obstructed kidneys from L-ENG+ than in WT mice. Our results suggest that the higher increase of renal fibrosis observed in L-ENG+ mice is not due to a major abundance of myofibroblasts, as similar levels of α-SMA were observed in both L-ENG+ and WT mice, but to the higher collagen and fibronectin synthesis by these fibroblasts. Furthermore, in vivo L-Endoglin overexpression potentiates Smad1 and Smad3 pathways and this effect is associated with higher renal fibrosis development. PMID:25313562

Impaired hippocampal place cell dynamics in a mouse model of the 22q11.2 deletion

PubMed Central

Zaremba, Jeffrey D; Diamantopoulou, Anastasia; Danielson, Nathan B; Grosmark, Andres D; Kaifosh, Patrick W; Bowler, John C; Liao, Zhenrui; Sparks, Fraser T; Gogos, Joseph A; Losonczy, Attila

2018-01-01

Hippocampal place cells represent the cellular substrate of episodic memory. Place cell ensembles reorganize to support learning but must also maintain stable representations to facilitate memory recall. Despite extensive research, the learning-related role of place cell dynamics in health and disease remains elusive. Using chronic two-photon Ca2+ imaging in hippocampal area CA1 of wild-type and Df(16)A+/− mice, an animal model of 22q11.2 deletion syndrome, one of the most common genetic risk factors for cognitive dysfunction and schizophrenia, we found that goal-oriented learning in wild-type mice was supported by stable spatial maps and robust remapping of place fields toward the goal location. Df(16)A+/− mice showed a significant learning deficit accompanied by reduced spatial map stability and the absence of goal-directed place cell reorganization. These results expand our understanding of the hippocampal ensemble dynamics supporting cognitive flexibility and demonstrate their importance in a model of 22q11.2-associated cognitive dysfunction. PMID:28869582

Expression of human factors CD81, claudin-1, scavenger receptor, and occludin in mouse hepatocytes does not confer susceptibility to HCV entry.

PubMed

Hikosaka, Keisuke; Noritake, Hidenao; Kimura, Wataru; Sultana, Nishat; Sharkar, Mohammad T K; Tagawa, Yoh-Ichi; Uezato, Tadayoshi; Kobayashi, Yoshimasa; Wakita, Takaji; Miura, Naoyuki

2011-04-01

No suitable mouse model is available for studying chronic liver disease caused by hepatitis C virus (HCV). CD81, claudin-1, scavenger receptor class B type I, and occludin were recently reported to be the important factors in HCV entry into hepatocytes. We made transgenic mice (Alb-CCSO) expressing the four human proteins and examined whether HCV from a patient serum or HCV pseudoparticles (HCVpp) were capable of infecting them. HCV was not detected in the mouse serum after injecting the mice with HCV from a patient serum. We also found no indications of HCVpp entry into primary hepatocytes from Alb-CCSO mice. In addition, HCV-infectible Hep3B cells were fused with HCV-resistant primary mouse hepatocytes and the fused cells showed 35-fold lower infectivity compared to wild-type Hep3B cells, indicating that primary mouse hepatocytes have the inhibitory factor(s) in HCVpp entry. Our results suggest that the expression of the human factors does not confer susceptibility to HCV entry into the liver.

Chronic carbon monoxide treatment attenuates development of obesity and remodels adipocytes in mice fed a high-fat diet.

PubMed

Hosick, P A; AlAmodi, A A; Storm, M V; Gousset, M U; Pruett, B E; Gray, W; Stout, J; Stec, D E

2014-01-01

Induction of heme oxygenase-1 (HO-1) has been demonstrated to result in chronic weight loss in several rodent models of obesity. However, the specific contribution of the HO metabolite, carbon monoxide (CO) to this response remains unknown. In this study, we determined the effect of chronic low level administration of a specific CO donor on the progression of obesity and its effects on metabolism and adipocyte biology in mice fed a high-fat diet. Experiments were performed on C57BL/6J mice fed a high-fat diet (60%) from 4 weeks until 30 weeks of age. Mice were administered either the CO donor, carbon monoxide releasing molecules (CORM)-A1 (5 mg kg(-1), intraperitoneally every other day) or the inactive form of the drug (iCORM-A1). Body weights were measured weekly and fasted blood glucose, insulin as well as body composition were measured every 6 weeks. Food intake, O2 consumption, CO2 production, activity and body heat production were measured at 28 weeks after start of the experimental protocol. Chronic CORM-A1 attenuated the development of high fat induced obesity from 18 weeks until the end of the study. Chronic CORM-A1 treatment in mice fed a high-fat diet resulted in significant decreases in fasted blood glucose, insulin and body fat and increased O2 consumption and heat production as compared with mice treated with iCORM-A1. Chronic CORM-A1 treatment also resulted in a significant decrease in adipocyte size and an increase in adipocyte number and in NRF-1, PGC-1α and UCP1 protein levels in epidydmal fat. Our results demonstrate that chronic CO treatment prevents the development of high-fat diet induced obesity via stimulation of metabolism and remodeling of adipocytes.

Disruption of the Smad7 gene enhances CCI4-dependent liver damage and fibrogenesis in mice

PubMed Central

Hamzavi, Jafar; Ehnert, Sabrina; Godoy, Patricio; Ciuclan, Loredana; Weng, Honglei; Mertens, Peter R; Heuchel, Rainer; Dooley, Steven

2008-01-01

Transforming growth factor-β (TGF-β) signalling is induced in liver as a consequence of damage and contributes to wound healing with transient activation, whereas it mediates fibrogenesis with long-term up-regulation in chronic disease. Smad-dependent TGF-β effects are blunted by antagonistic Smad7, which is transcriptionally activated as an immediate early response upon initiation of TGF-β signalling in most cell types, thereby providing negative feedback regulation. Smad7 can be induced by other cytokines, e.g. IFN-γ, leading to a crosstalk of these signalling pathways. Here we report on a novel mouse strain, denoted S7ΔE1, with a deletion of exon I from the endogenous smad7 gene. The mice were viable and exhibited normal adult liver architecture. To obtain insight into Smad7-depend-ent protective effects, chronic liver damage was induced in mice by carbon tetrachloride (CCI4) administration. Subsequent treatment, elevated serum liver enzymes indicated enhanced liver damage in mice lacking functional Smad7. CCI4-dependent Smad2 phosphoryla-tion was pronounced in S7ΔE1 mice and accompanied by increased numbers of α-smooth muscle actin positive ‘activated’ HSCs. There was evidence for matrix accumulation, with elevated collagen deposition as assessed morphometrically in Sirius red stained tissue and confirmed with higher levels of hydroxyproline in S7ΔE1 mice. In addition, the number of CD43 positive infiltrating lymphocytes as well as of apoptotic hepatocytes was increased. Studies with primary hepatocytes from S7ΔE1 and wild-type mice indicate that in the absence of functional Smad7 protein, hepatocytes are more sensitive for TGF-β effects resulting in enhanced cell death. Furthermore, S7ΔE1 hepatocytes display increased oxidative stress and cell damage in response to CCI4, as measured by reactive oxygen species production, glutathione depletion, lactate dehydrogenase release and lipid peroxidation. Using an ALK-5 inhibitor all investigated CCI4 effects on hepatocytes were blunted, confirming participation of TGF-β signalling. We conclude that Smad7 mediates a protective effect from adverse TGF-β signalling in damaged liver, re-iterating its negative regulatory loop on signalling. PMID:18266971

Protective Role of γδ T Cells in Cigarette Smoke and Influenza Infection

PubMed Central

Hong, M. J.; Gu, B. H.; Madison, M.; Landers, C.; Tung, H. Y.; Kim, M.; Yuan, X.; You, R.; MacHado, A. A.; Gilbert, B. E.; Soroosh, P.; Elloso, M.; Song, L.; Chen, M.; Corry, D. B.; Diehl, G.; Kheradmand, F.

2017-01-01

Airborne pathogens commonly trigger severe respiratory failure or death in smokers with lung disease. Cigarette smoking compromises the effectiveness of innate immunity against infections but the underlying mechanisms responsible for defective acquired immune responses in smokers remains less clear. We found that mice exposed to chronic cigarette smoke recovered poorly from primary Influenza A pneumonia with reduced type I and II interferons (IFNs) and viral-specific immunoglobulins, but recruited gamma delta (γδ) T cells to the lungs that predominantly expressed interleukin 17A (IL-17A). Il-17a-/- mice exposed to smoke and infected with Influenza A also recruited γδ T cells to the lungs, but in contrast to wild type mice, expressed increased IFNs, made protective influenza specific antibodies, and recovered from infection. Depletion of IL-17A with blocking antibodies significantly increased T-bet expression in γδ T cells and improved recovery from acute Influenza A infection in air, but not smoke exposed mice. In contrast, when exposed to smoke, γδ T cell deficient mice failed to mount an effective immune response to Influenza A and showed increased mortality. Our findings demonstrate a protective role for γδ T cells in smokers and suggest that smoke-induced increase in IL-17A inhibits the transcriptional programs required for their optimal anti-viral responses. PMID:29091081

Modulating proximal cell signaling by targeting Btk ameliorates humoral autoimmunity and end-organ disease in murine lupus.

PubMed

Hutcheson, Jack; Vanarsa, Kamala; Bashmakov, Anna; Grewal, Simer; Sajitharan, Deena; Chang, Betty Y; Buggy, Joseph J; Zhou, Xin J; Du, Yong; Satterthwaite, Anne B; Mohan, Chandra

2012-11-08

Systemic lupus erythematosus is a chronic autoimmune disease characterized by an abundance of autoantibodies against nuclear antigens. Bruton's tyrosine kinase (Btk) is a proximal transducer of the BCR signal that allows for B-cell activation and differentiation. Recently, selective inhibition of Btk by PCI-32765 has shown promise in limiting activity of multiple cells types in various models of cancer and autoimmunity. The aim of this study was to determine the effect of Btk inhibition by PCI-32765 on the development of lupus in lupus-prone B6.Sle1 and B6.Sle1.Sle3 mice. B6.Sle1 or B6.Sle1.Sle3 mice received drinking water containing either the Btk inhibitor PCI-32765 or vehicle for 56 days. Following treatment, mice were examined for clinical and pathological characteristics of lupus. The effect of PCI-32765 on specific cell types was also investigated. In this study, we report that Btk inhibition dampens humoral autoimmunity in B6.Sle1 monocongenic mice. Moreover, in B6.Sle1.Sle3 bicongenic mice that are prone to severe lupus, Btk inhibition also dampens humoral and cellular autoimmunity, as well as lupus nephritis. These findings suggest that partial crippling of cell signaling in B cells and antigen presenting cells (APCs) may be a viable alternative to total depletion of these cells as a therapeutic modality for lupus.

PD-L1–Driven Tolerance Protects Neurogenin3-Induced Islet Neogenesis to Reverse Established Type 1 Diabetes in NOD Mice

PubMed Central

Li, Rongying; Lee, Jeongkyung; Kim, Mi-sun; Liu, Victoria; Moulik, Mousumi; Li, Haiyan; Yi, Qing; Xie, Aini; Chen, Wenhao; Yang, Lina; Li, Yimin; Tsai, Tsung Huang; Oka, Kazuhiro

2015-01-01

A breakdown in self-tolerance underlies autoimmune destruction of β-cells and type 1 diabetes. A cure by restoring β-cell mass is limited by the availability of transplantable β-cells and the need for chronic immunosuppression. Evidence indicates that inhibiting costimulation through the PD-1/PD-L1 pathway is central to immune tolerance. We therefore tested whether induction of islet neogenesis in the liver, protected by PD-L1–driven tolerance, reverses diabetes in NOD mice. We demonstrated a robust induction of neo-islets in the liver of diabetic NOD mice by gene transfer of Neurogenin3, the islet-defining factor, along with betacellulin, an islet growth factor. These neo-islets expressed all the major pancreatic hormones and transcription factors. However, an enduring restoration of glucose-stimulated insulin secretion and euglycemia occurs only when tolerance is also induced by the targeted overexpression of PD-L1 in the neo-islets, which results in inhibition of proliferation and increased apoptosis of infiltrating CD4+ T cells. Further analysis revealed an inhibition of cytokine production from lymphocytes isolated from the liver but not from the spleen of treated mice, indicating that treatment did not result in generalized immunosuppression. This treatment strategy leads to persistence of functional neo-islets that resist autoimmune destruction and consequently an enduring reversal of diabetes in NOD mice. PMID:25332429

Role of deferoxamine on enzymatic stress markers in an animal model of Alzheimer's disease after chronic aluminum exposure.

PubMed

Esparza, José L; Garcia, Tania; Gómez, Mercedes; Nogués, M Rosa; Giralt, Montserrat; Domingo, José L

2011-06-01

The effect of the chelator deferoxamine (DFO) on the activity of enzymatic stress markers was assessed in amyloid beta peptide (AβPP) transgenic mice, an animal model of Alzheimer's disease, after oral aluminum (Al) exposure for 6 months. AβPP transgenic (Tg2576) and C57BL6/SJL wild-type mice of 5 months of age were fed a diet supplemented with Al lactate (1 mg of Al/g food). Four groups of Tg2576 and wild-type animals were used: control, Al only, DFO only, and Al plus DFO. Mice in the DFO-treated groups received also subcutaneous injections of 0.20 mmol/kg/d of this chelating agent twice a week until the end of the study at 11 months of age. The hippocampus, cerebellum, and cortex were removed and processed to examine a number of oxidative stress markers. Furthermore, the expression of Cu-Zn superoxide dismutase, glutathione reductase, and catalase was evaluated by quantitative reverse transcriptase polymerase chain reaction analysis. Aluminum levels in the hippocampus of Tg2576 mice were higher than those found in cerebellum and cortex, while the main oxidative effects were evidenced in the presence of DFO only. Oral Al exposure of AβPP transgenic mice would have some potential to promote pro-oxidant events, while DFO administration would not help in preventing these deleterious effects.

Progesterone modulation of alpha5 nAChR subunits influences anxiety-related behavior during estrus cycle.

PubMed

Gangitano, D; Salas, R; Teng, Y; Perez, E; De Biasi, M

2009-06-01

Smokers often report an anxiolytic effect of cigarettes. In addition, stress-related disorders such as anxiety, post-traumatic stress syndrome and depression are often associated with chronic nicotine use. To study the role of the alpha5 nicotinic acetylcholine receptor subunit in anxiety-related responses, control and alpha5 subunit null mice (alpha5(-/-)) were subjected to the open field activity (OFA), light-dark box (LDB) and elevated plus maze (EPM) tests. In the OFA and LDB, alpha5(-/-) behaved like wild-type controls. In the EPM, female alpha5(-/-) mice displayed an anxiolytic-like phenotype, while male alpha5(-/-) mice were undistinguishable from littermate controls. We studied the hypothalamus-pituitary-adrenal axis by measuring plasma corticosterone and hypothalamic corticotropin-releasing factor. Consistent with an anxiolytic-like phenotype, female alpha5(-/-) mice displayed lower basal corticosterone levels. To test whether gonadal steroids regulate the expression of alpha5, we treated cultured NTera 2 cells with progesterone and found that alpha5 protein levels were upregulated. In addition, brain levels of alpha5 mRNA increased upon progesterone injection into ovariectomized wild-type females. Finally, we tested anxiety levels in the EPM during the estrous cycle. The estrus phase (when progesterone levels are low) is anxiolytic-like in wild-type mice, but no cycle-dependent fluctuations in anxiety levels were found in alpha5(-/-) females. Thus, alpha5-containing neuronal nicotinic acetylcholine receptors may be mediators of anxiogenic responses, and progesterone-dependent modulation of alpha5 expression may contribute to fluctuations in anxiety levels during the ovarian cycle.

Expression of gp120 in mice evokes anxiety behavior: Co-occurrence with increased dendritic spines and brain-derived neurotrophic factor in the amygdala.

PubMed

Bachis, Alessia; Forcelli, Patrick; Masliah, Eliezer; Campbell, Lee; Mocchetti, Italo

2016-05-01

Human immunodeficiency virus type 1 (HIV) infection of the brain produces cognitive and motor disorders. In addition, HIV positive individuals exhibit behavioral alterations, such as apathy, and a decrease in spontaneity or emotional responses, typically seen in anxiety disorders. Anxiety can lead to psychological stress, which has been shown to influence HIV disease progression. These considerations underscore the importance of determining if anxiety in HIV is purely psychosocial, or if by contrast, there are the molecular cascades associated directly with HIV infection that may mediate anxiety. The present study had two goals: (1) to determine if chronic exposure to viral proteins would induce anxiety-like behavior in an animal model and (2) to determine if this exposure results in anatomical abnormalities that could explain increased anxiety. We have used gp120 transgenic mice, which display behavior and molecular deficiencies similar to HIV positive subjects with cognitive and motor impairments. In comparison to wild type mice, 6 months old gp120 transgenic mice demonstrated an anxiety like behavior measured by open field, light/dark transition task, and prepulse inhibition tests. Moreover, gp120 transgenic mice have an increased number of spines in the amygdala, as well as higher levels of brain-derived neurotrophic factor and tissue plasminogen activator when compared to age-matched wild type. Our data support the hypothesis that HIV, through gp120, may cause structural changes in the amygdala that lead to maladaptive responses to anxiety. Copyright © 2016 Elsevier Inc. All rights reserved.

Genetic Phagocyte NADPH Oxidase Deficiency Enhances Nonviable Candida albicans-Induced Inflammation in Mouse Lungs.

PubMed

Endo, Daiki; Fujimoto, Kenta; Hirose, Rika; Yamanaka, Hiroko; Homme, Mizuki; Ishibashi, Ken-Ichi; Miura, Noriko; Ohno, Naohito; Aratani, Yasuaki

2017-02-01

Patients with chronic granulomatous disease (CGD) have mutated phagocyte NADPH oxidase, resulting in reduced production of reactive oxygen species (ROS). While the mechanism underlying hyperinfection in CGD is well understood, the basis for inflammatory disorders that arise in the absence of evident infection has not been fully explained. This study aimed to evaluate the effect of phagocyte NADPH oxidase deficiency on lung inflammation induced by nonviable Candida albicans (nCA). Mice deficient in this enzyme (CGD mice) showed more severe neutrophilic pneumonia than nCA-treated wild-type mice, which exhibited significantly higher lung concentrations of interleukin (IL)-1β, tumor necrosis factor (TNF)-α, and keratinocyte-derived chemokine (KC). Neutralization of these proinflammatory mediators significantly reduced neutrophil infiltration. In vitro, production of IL-1β and TNF-α from neutrophils and that of KC from macrophages was enhanced in nCA-stimulated neutrophils from CGD mice. Expression of IL-1β mRNA was higher in the stimulated CGD neutrophils than in the stimulated wild-type cells, concomitant with upregulation of nuclear factor (NF)-κB and its upstream regulator extracellular-signal regulated kinase (ERK) 1/2. Pretreatment with an NADPH oxidase inhibitor significantly enhanced IL-1β production in the wild-type neutrophils stimulated with nCA. These results suggest that lack of ROS production because of NADPH oxidase deficiency results in the production of higher levels of proinflammatory mediators from neutrophils and macrophages, which may at least partly contribute to the exacerbation of nCA-induced lung inflammation in CGD mice.

Phagocyte NADPH Oxidase, but Not Inducible Nitric Oxide Synthase, Is Essential for Early Control of Burkholderia cepacia and Chromobacterium violaceum Infection in Mice

PubMed Central

Segal, Brahm H.; Ding, Li; Holland, Steven M.

2003-01-01

Reactive oxygen and nitrogen intermediates have critical, partially overlapping roles in host defense against a variety of pathogens. Using mice deficient in generating phagocyte superoxide (p47phox−/−) and mice deficient in generating inducible nitric oxide synthase (iNOS−/−), we examined the roles of these reactive species in host defense against Burkholderia cepacia and Chromobacterium violaceum, organisms known to have unusual virulence in chronic granulomatous disease. Intraperitoneal B. cepacia challenge (4.0 × 103 to 4.0 × 105 organisms/mouse) resulted in mortality in all p47phox−/− mice, with the survival interval being inversely proportionate to the amount of inoculum. Pretreatment with gamma interferon did not affect survival. C. violaceum was strikingly virulent in p47phox−/− mice (the 50% lethal dose [LD50] was <13 organisms). iNOS−/− and wild-type mice were resistant to B. cepacia challenges of at least 106 organisms per mouse, and the LD50 of C. violaceum was between 106 and 107 organisms per mouse. Consistent with the survival data, numbers of organisms in cultures of B. cepacia from multiple sites were higher for p47phox−/− mice than for iNOS−/− and wild-type mice at day 4 after challenge, but numbers of organisms for different B. cepacia strains varied. The recovery of C. violaceum was strikingly greater at 18 h after challenge for p47phox−/− mice than for iNOS−/− and wild-type mice, in which the organism burdens were virtually nil. In vitro, both B. cepacia and C. violaceum were sensitive to H2O2 and to reactive nitrogen intermediates but the sensitivities of different strains varied significantly. Host defense against B. cepacia and C. violaceum is critically dependent in vivo on reactive oxygen intermediates, and these species are model organisms to further dissect host and pathogen interactions related to the generation and scavenging of microbicidal reactive intermediates. PMID:12496167

Increased intake of energy-dense diet and negative energy balance in a mouse model of chronic psychosocial defeat.

PubMed

Coccurello, Roberto; Romano, Adele; Giacovazzo, Giacomo; Tempesta, Bianca; Fiore, Marco; Giudetti, Anna Maria; Marrocco, Ilaria; Altieri, Fabio; Moles, Anna; Gaetani, Silvana

2018-06-01

Chronic exposure to stress may represent a risk factor for developing metabolic and eating disorders, mostly driven by the overconsumption of easily accessible energy-dense palatable food, although the mechanisms involved remain still unclear. In this study, we used an ethologically oriented murine model of chronic stress caused by chronic psychosocial defeat (CPD) to investigate the effects of unrestricted access to a palatable high fat diet (HFD) on food intake, body weight, energy homeostasis, and expression of different brain neuropeptides. Our aim was to shed light on the mechanisms responsible for body weight and body composition changes due to chronic social stress. In our model of subordinate (defeated), mice (CPD) cohabitated in constant sensory contact with dominants, being forced to interact on daily basis, and were offered ad libitum access either to an HFD or to a control diet (CD). Control mice (of the same strain as CPD mice) were housed in pairs and left unstressed in their home cage (UN). In all these mice, we evaluated body weight, different adipose depots, energy metabolism, caloric intake, and neuropeptide expression. CPD mice increased the intake of HFD and reduced body weight in the presence of enhanced lipid oxidation. Resting energy expenditure and interscapular brown adipose tissue (iBAT) were increased in CPD mice, whereas epididymal adipose tissue increased only in HFD-fed unstressed mice. Propiomelanocortin mRNA levels in hypothalamic arcuate nucleus increased only in HFD-fed unstressed mice. Oxytocin mRNA levels in the paraventricular nucleus and neuropeptide Y mRNA levels within the arcuate were increased only in CD-fed CPD mice. In the arcuate, CART was increased in HFD-fed UN mice and in CD-fed CPD mice, while HFD intake suppressed CART increase in defeated animals. In the basolateral amygdala, CART expression was increased only in CPD animals on HFD. CPD appears to uncouple the intake of HFD from energy homeostasis causing higher HFD intake, larger iBAT accumulation, increased energy expenditure and lipid oxidation, and lower body weight. Overall, the present study confirms the notion that the chronic activation of the stress response can be associated with metabolic disorders, altered energy homeostasis, and changes of orexigenic and anorexigenic signaling. These changes might be relevant to better understand the etiology of stress-induced obesity and eating disorders and might represent a valid therapeutic approach for the development of new therapies in this field.

Antidepressant and anxiolytic like effects of Urtica dioica leaves in streptozotocin induced diabetic mice.

PubMed

Patel, Sita Sharan; Ray, R S; Sharma, Arun; Mehta, Vineet; Katyal, Anju; Udayabanu, Malairaman

2018-04-27

The present study was aimed to investigate the effect of Urtica dioica Linn. (UD) extract against chronic diabetes mediated anxiogenic and depressive like behavior in mice. Streptozotocin (STZ) (50 mg/kg, i.p.) for 5 consecutive days was used to induce diabetes followed by treatment with UD leaves extract (50 mg/kg, p.o.) and rosiglitazone (ROSI) (5 mg/kg, p.o.) for 8 weeks. STZ induced chronic diabetes significantly induced anxiety and depressive like behavior in mice. Chronic diabetes significantly downregulated BDNF (p < 0.001), TrKB (p < 0.001), Cyclin D1 (p < 0.001), Bcl2 (p < 0.05) and autophagy7 (p < 0.001), while upregulated iNOS (p < 0.05) mRNA expression in the hippocampus as compared to control mice. In addition, chronic diabetes significantly increased the expression of TNF-α in CA1 (p < 0.001), CA2 (p < 0.01), CA3 (p < 0.001) and DG (p < 0.001) regions of hippocampus as compared to control mice. Chronic diabetes mediated neuronal damage in the CA2, CA3 and DG regions of hippocampus. Chronic administration of UD leaves extract significantly reversed diabetes mediated anxiogenic and depressive like behavior in mice. Further, UD treatment significantly upregulated BDNF (p < 0.01), TrKB (p < 0.001), Cyclin D1 (p < 0.001), Bcl2 (p < 0.01), autophagy5 (p < 0.01) and autophagy7 (p < 0.001), while downregulated iNOS (p < 0.05) mRNA expression in the hippocampus of diabetic mice. Concomitantly, UD administration significantly decreased the expression of TNF-α in hippocampal CA1 (p < 0.001), CA2 (p < 0.01), CA3 (p < 0.001) and DG (p < 0.001) regions of diabetic mice. Diabetes mediated neuronal damage and DNA fragmentation in the hippocampus was substantially attenuated following UD treatment. UD leaves extract might prove to be effective for diabetes mediated anxiety and depressive like behavior.

Cannabinoid-mediated diversity of antinociceptive efficacy of parecoxib in Wistar and Sprague Dawley rats in the chronic constriction injury model of neuropathic pain.

PubMed

Becker, Axel; Geisslinger, Gerd; Murín, Radovan; Grecksch, Gisela; Höllt, Volker; Zimmer, Andreas; Schröder, Helmut

2013-05-01

We studied nociceptive behavior and the effects of analgesics in Wistar (Wist) and Sprague Dawley (SPD) rats and in CB1 receptor-deficient mice with neuropathic pain experimentally. Neuropathic pain was induced by loose ligation of the sciatic nerve (chronic constriction injury, CCI). In CCI rats from both strains, cold allodynia and a reduced thermal pain threshold were detected, whereas no effect was found in the hot plate test. Thermal pain threshold was used to study the antinociceptive effects of morphine, gabapentin, and parecoxib 5 days after surgery. Doses of gabapentin and morphine which had no effect on sham-operated animals provoked antinociceptive activity in CCI rats from both strains. An antinociceptive effect of parecoxib was only found in CCI Wist rats. No pharmacokinetic differences were detected between the two strains in parecoxib metabolism. Antinociceptive activity caused by parecoxib was attenuated by the CB1 antagonist rimonabant. To further clarify parecoxib-CB1 interaction, the effect of parecoxib was investigated in CB1-deficient mice and wild-type animals. CCI did not affect thermal pain threshold and mechanical pain threshold was decreased. Parecoxib normalized the altered mechanical pain threshold in CCI wild-type animals, whereas it had only a marginal effect in CB1 receptor deficient mice. Receptor binding experiments showed increased CB1 binding in parecoxib-treated CCI Wist rats. Levels of the CB1 receptor mRNA remained constant in both strains of rats 5 days after surgery. Differences in antinociceptive activity might be due to modification of the cannabinoid system.

Accumulation of oxidized LDL in the tendon tissues of C57BL/6 or apolipoprotein E knock-out mice that consume a high fat diet: potential impact on tendon health.

PubMed

Grewal, Navdeep; Thornton, Gail M; Behzad, Hayedeh; Sharma, Aishwariya; Lu, Alex; Zhang, Peng; Reid, W Darlene; Granville Alex Scott, David J

2014-01-01

Clinical studies have suggested an association between dyslipidemia and tendon injuries or chronic tendon pain; the mechanisms underlying this association are not yet known. The objectives of this study were (1) to evaluate the impact of a high fat diet on the function of load-bearing tendons and on the distribution in tendons of oxidized low density lipoprotein (oxLDL), and (2) to examine the effect of oxLDL on tendon fibroblast proliferation and gene expression. Gene expression (Mmp2, Tgfb1, Col1a1, Col3a1), fat content (Oil Red O staining), oxLDL levels (immunohistochemistry) and tendon biomechanical properties were examined in mice (C57Bl/6 or ApoE -/-) receiving a standard or a high fat diet. Human tendon fibroblast proliferation and gene expression (COL1A1, COL3A1, MMP2) were examined following oxLDL exposure. In both types of mice (C57Bl/6 or ApoE -/-), consumption of a high fat diet led to a marked increase in oxLDL deposition in the load-bearing extracellular matrix of the tendon. The consumption of a high fat diet also reduced the failure stress and load of the patellar tendon in both mouse types, and increased Mmp2 expression. ApoE -/- mice exhibited more pronounced reductions in tendon function than wild-type mice, and decreased expression of Col1a1 compared to wild type mice. Human tendon fibroblasts responded to oxLDL by increasing their proliferation and their mRNA levels of MMP2, while decreasing their mRNA levels for COL1A1 and COL3A1. The consumption of a high fat diet resulted in deleterious changes in tendon function, and these changes may be explained in part by the effects of oxLDL, which induced a proliferative, matrix-degrading phenotype in human tenocytes.