The neuropathology observed in wild-type mice inoculated with human poliovirus mirrors human paralytic poliomyelitis.

PubMed

Ford, Dayton J; Ropka, Stacie L; Collins, George H; Jubelt, Burk

2002-09-01

Human paralytic poliomyelitis results from the destruction of spinal cord anterior horn motor neurons by human poliovirus (PV). CNS disease pathology similar to human poliomyelitis has been observed in experimentally infected chimpanzees, monkeys and wild-type mice. In this study we present a detailed examination of the clinical and histopathological features in the wild-type mouse after intracranial (i.c.) and novel intramuscular (i.m.) injection of poliovirus. Either route of poliovirus administration results in a clinical disease characterized predominately by flaccid paralysis. The observed histopathological features are compared with the histopathology reported for human paralytic poliomyelitis, experimentally infected chimpanzees, monkeys and transgenic mice expressing the human poliovirus receptor (hPVR). The observation of flaccid paralysis and anterior horn motor neuron destruction mirrors what is observed in human paralytic poliomyelitis. Our results suggest that the neuropathology observed in the wild-type mouse model is similar to what has been observed in both the human disease and in other experimental animal models, with the possible exception of the transgenic mouse model. The observed neuropathology of the wild-type mouse model more closely reflects what has been observed in human poliomyelitis, as well as in experimentally infected chimpanzees and monkeys, than does the hPVR transgenic mouse model. The previously reported poliovirus-induced white matter demyelinating disease was not observed.

Characterization of a sensitive mouse Aβ40 PD biomarker assay for Alzheimer's disease drug development in wild-type mice.

PubMed

Lu, Yanmei; Hoyte, Kwame; Montgomery, William H; Luk, Wilman; He, Dongping; Meilandt, William J; Zuchero, Y Joy Yu; Atwal, Jasvinder K; Scearce-Levie, Kimberly; Watts, Ryan J; DeForge, Laura E

2016-05-01

Transgenic mice that overexpress human amyloid precursor protein with Swedish or London (APPswe or APPlon) mutations have been widely used for preclinical Alzheimer's disease (AD) drug development. AD patients, however, rarely possess these mutations or overexpress APP. We developed a sensitive ELISA that specifically and accurately measures low levels of endogenous Aβ40 in mouse plasma, brain and CSF. In wild-type mice treated with a bispecific anti-TfR/BACE1 antibody, significant Aβ reductions were observed in the periphery and the brain. APPlon transgenic mice showed a slightly less reduction, whereas APPswe mice did not have any decrease. This sensitive and well-characterized mouse Aβ40 assay enables the use of wild-type mice for preclinical PK/PD and efficacy studies of potential AD therapeutics.

Effects of social stress and intrauterine position on sexual phenotype in wild-type house mice (Mus musculus)

Treesearch

William J. Zielinski; John G. Vandenbergh; Monica M. Montano

1991-01-01

Wild-type house mice were used to test the effect of intrauterine position on anogenital distance (AGD) and to verify whether crowding stress would masculinize female pups, developing at all intrauterine positions, as has been demonstrated in CF-1 mice stressed by restraint, heat, and...

Insights into wild-type and mutant p53 functions provided by genetically engineered mice.

PubMed

Donehower, Lawrence A

2014-06-01

Recent whole-exome sequencing studies of numerous human cancers have now conclusively shown that the TP53 tumor-suppressor gene is the most frequently mutated gene in human cancers. Despite extensive studies of the TP53 gene and its encoded protein (p53), our understanding of how TP53 mutations contribute to cancer initiation and progression remain incomplete. Genetically engineered mice with germline or inducible Trp53 somatic mutations have provided important insights into the mechanisms by which different types of p53 mutation influence cancer development. Trp53 germline mutations that alter specific p53 structural domains or posttranslation modification sites have benefitted our understanding of wild-type p53 functions in a whole organism context. Moreover, genetic approaches to reestablish functional wild-type p53 to p53-deficient tissues and tumors have increased our understanding of the therapeutic potential of restoring functional p53 signaling to cancers. This review outlines many of the key insights provided by the various categories of Trp53 mutant mice that have been generated by multiple genetic engineering approaches. © 2014 WILEY PERIODICALS, INC.

Spontaneous hepatic repopulation in transgenic mice expressing mutant human α1-antitrypsin by wild-type donor hepatocytes

PubMed Central

Ding, Jianqiang; Yannam, Govardhana R.; Roy-Chowdhury, Namita; Hidvegi, Tunda; Basma, Hesham; Rennard, Stephen I.; Wong, Ronald J.; Avsar, Yesim; Guha, Chandan; Perlmutter, David H.; Fox, Ira J.; Roy-Chowdhury, Jayanta

2011-01-01

α1-Antitrypsin deficiency is an inherited condition that causes liver disease and emphysema. The normal function of this protein, which is synthesized by the liver, is to inhibit neutrophil elastase, a protease that degrades connective tissue of the lung. In the classical form of the disease, inefficient secretion of a mutant α1-antitrypsin protein (AAT-Z) results in its accumulation within hepatocytes and reduced protease inhibitor activity, resulting in liver injury and pulmonary emphysema. Because mutant protein accumulation increases hepatocyte cell stress, we investigated whether transplanted hepatocytes expressing wild-type AAT might have a competitive advantage relative to AAT-Z–expressing hepatocytes, using transgenic mice expressing human AAT-Z. Wild-type donor hepatocytes replaced 20%–98% of mutant host hepatocytes, and repopulation was accelerated by injection of an adenovector expressing hepatocyte growth factor. Spontaneous hepatic repopulation with engrafted hepatocytes occurred in the AAT-Z–expressing mice even in the absence of severe liver injury. Donor cells replaced both globule-containing and globule-devoid cells, indicating that both types of host hepatocytes display impaired proliferation relative to wild-type hepatocytes. These results suggest that wild-type hepatocyte transplantation may be therapeutic for AAT-Z liver disease and may provide an alternative to protein replacement for treating emphysema in AAT-ZZ individuals. PMID:21505264

Spontaneous hepatic repopulation in transgenic mice expressing mutant human α1-antitrypsin by wild-type donor hepatocytes.

PubMed

Ding, Jianqiang; Yannam, Govardhana R; Roy-Chowdhury, Namita; Hidvegi, Tunda; Basma, Hesham; Rennard, Stephen I; Wong, Ronald J; Avsar, Yesim; Guha, Chandan; Perlmutter, David H; Fox, Ira J; Roy-Chowdhury, Jayanta

2011-05-01

α1-Antitrypsin deficiency is an inherited condition that causes liver disease and emphysema. The normal function of this protein, which is synthesized by the liver, is to inhibit neutrophil elastase, a protease that degrades connective tissue of the lung. In the classical form of the disease, inefficient secretion of a mutant α1-antitrypsin protein (AAT-Z) results in its accumulation within hepatocytes and reduced protease inhibitor activity, resulting in liver injury and pulmonary emphysema. Because mutant protein accumulation increases hepatocyte cell stress, we investigated whether transplanted hepatocytes expressing wild-type AAT might have a competitive advantage relative to AAT-Z-expressing hepatocytes, using transgenic mice expressing human AAT-Z. Wild-type donor hepatocytes replaced 20%-98% of mutant host hepatocytes, and repopulation was accelerated by injection of an adenovector expressing hepatocyte growth factor. Spontaneous hepatic repopulation with engrafted hepatocytes occurred in the AAT-Z-expressing mice even in the absence of severe liver injury. Donor cells replaced both globule-containing and globule-devoid cells, indicating that both types of host hepatocytes display impaired proliferation relative to wild-type hepatocytes. These results suggest that wild-type hepatocyte transplantation may be therapeutic for AAT-Z liver disease and may provide an alternative to protein replacement for treating emphysema in AAT-ZZ individuals.

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.

Ablation of the Locus Coeruleus Increases Oxidative Stress in Tg-2576 Transgenic but Not Wild-Type Mice

PubMed Central

Hurko, Orest; Boudonck, Kurt; Gonzales, Cathleen; Hughes, Zoe A.; Jacobsen, J. Steve; Reinhart, Peter H.; Crowther, Daniel

2010-01-01

Mice transgenic for production of excessive or mutant forms of beta-amyloid differ from patients with Alzheimer's disease in the degree of inflammation, oxidative damage, and alteration of intermediary metabolism, as well as the paucity or absence of neuronal atrophy and cognitive impairment. Previous observers have suggested that differences in inflammatory response reflect a discrepancy in the state of the locus coeruleus (LC), loss of which is an early change in Alzheimer's disease but which is preserved in the transgenic mice. In this paper, we extend these observations by examining the effects of the LC on markers of oxidative stress and intermediary metabolism. We compare four groups: wild-type or Tg2576 Aβ transgenic mice injected with DSP4 or vehicle. Of greatest interest were metabolites different between ablated and intact transgenics, but not between ablated and intact wild-type animals. The Tg2576_DSP4 mice were distinguished from the other three groups by oxidative stress and altered energy metabolism. These observations provide further support for the hypothesis that Tg2576 Aβ transgenic mice with this ablation may be a more congruent model of Alzheimer's disease than are transgenics with an intact LC. PMID:20981353

Further studies on cortical tangential migration in wild type and Pax-6 mutant mice.

PubMed

Jiménez, D; López-Mascaraque, L; de Carlos, J A; Valverde, F

2002-01-01

In this study we present new data concerning the tangential migration from the medial and lateral ganglionic eminences (MGE and LGE) to the cerebral cortex during development. We have used Calbindin as a useful marker to follow the itinerary of tangential migratory cells during early developmental stages in wild-type and Pax-6 homozygous mutant mice. In the wild-type mice, at early developmental stages, migrating cells advance through the intermediate zone (IZ) and preplate (PP). At more advanced stages, migrating cells were present in the subplate (SP) and cortical plate (CP) to reach the entire developing cerebral cortex. We found that, in the homozygous mutant mice (Pax-6(Sey-Neu)/Pax-6(Sey-Neu)), this tangential migration is severely affected at early developmental stages: migrating cells were absent in the IZ, which were only found some days later, suggesting that in the mutant mice, there is a temporal delay in tangential migration. We have also defined some possible mechanisms to explain certain migratory routes from the basal telencephalon to the cerebral cortex. We describe the existence of two factors, which we consider to be essential for the normal migration; the first one is the cell adhesion molecule PSA-NCAM, whose role in other migratory systems is well known. The second factor is Robo-2, whose expression delimits a channel for the passage of migratory cells from the basal telencephalon to the cerebral cortex.

Conditional rescue of protein kinase C epsilon regulates ethanol preference and hypnotic sensitivity in adult mice.

PubMed

Choi, Doo-Sup; Wang, Dan; Dadgar, Jahan; Chang, Wesley S; Messing, Robert O

2002-11-15

Conventional gene targeting is a powerful tool to study the influence of specific genes on behavior. However, conclusions relevant for adult animals are limited by consequences of gene loss during development. Mice lacking protein kinase C epsilon (PKCepsilon) consume less alcohol and show greater acute sensitivity to alcohol than do wild-type mice. There are no selective inhibitors of PKCepsilon that can be administered systemically and cross the blood-brain barrier to test whether these phenotypes result from loss of PKCepsilon during development or in adulthood. Here we used conditional expression of PKCepsilon in the basal forebrain, amygdala, and cerebellum to rescue wild-type responses to alcohol in adult PKCepsilon(-/-) mice. Subsequent suppression of transgenic PKCepsilon restored PKCepsilon(-/-) behaviors. These findings establish that PKCepsilon signaling in the adult brain regulates alcohol consumption and sensitivity. If this extends to humans, then PKCepsilon inhibitors might prove useful as novel therapeutics for alcoholism.

Taste responses to sweet stimuli in alpha-gustducin knockout and wild-type mice.

PubMed

Danilova, Vicktoria; Damak, Sami; Margolskee, Robert F; Hellekant, Göran

2006-07-01

The importance of alpha-gustducin in sweet taste transduction is based on data obtained with sucrose and the artificial sweetener SC45647. Here we studied the role of alpha-gustducin in sweet taste. We compared the behavioral and electrophysiological responses of alpha-gustducin knockout (KO) and wild-type (WT) mice to 11 different sweeteners, representing carbohydrates, artificial sweeteners, and sweet amino acids. In behavioral experiments, over 48-h preference ratios were measured in two-bottle preference tests. In electrophysiological experiments, integrated responses of chorda tympani (CT) and glossopharyngeal (NG) nerves were recorded. We found that preference ratios of the KO mice were significantly lower than those of WT for acesulfame-K, dulcin, fructose, NC00174, D-phenylalanine, L-proline, D-tryptophan, saccharin, SC45647, sucrose, but not neotame. The nerve responses to all sweeteners, except neotame, were smaller in the KO mice than in the WT mice. The differences between the responses in WT and KO mice were more pronounced in the CT than in the NG. These data indicate that alpha-gustducin participates in the transduction of the sweet taste in general.

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

Paternal spatial training enhances offspring's cognitive performance and synaptic plasticity in wild-type but not improve memory deficit in Alzheimer's mice.

PubMed

Zhang, Shujuan; Li, Xiaoguang; Wang, Zhouyi; Liu, Yanchao; Gao, Yuan; Tan, Lu; Liu, Enjie; Zhou, Qiuzhi; Xu, Cheng; Wang, Xin; Liu, Gongping; Chen, Haote; Wang, Jian-Zhi

2017-05-08

Recent studies suggest that spatial training can maintain associative memory capacity in Tg2576 mice, but it is not known whether the beneficial effects can be inherited from the trained fathers to their offspring. Here, we exposed male wild-type and male 3XTg Alzheimer disease (AD) mice (3-m old) respectively to spatial training for one week and assessed the transgenerational effects in the F1 offspring when they were grown to 7-m old. We found that the paternal spatial training significantly enhanced progeny's spatial cognitive performance and synaptic transmission in wild-type mice. Among several synapse- or memory-associated proteins, we observed that the expression level of synaptotagmin 1 (SYT1) was significantly increased in the hippocampus of the paternally trained-offspring. Paternal training increased histone acetylation at the promoter of SYT1 in both fathers' and the offspring's hippocampus, and as well as in the fathers' sperm. Finally, paternal spatial training for one week did not improve memory and synaptic plasticity in 3XTg AD F1 offspring. Our findings suggest paternal spatial training for one week benefits the offspring's cognitive performance in wild-type mice with the mechanisms involving an enhanced transgenerational histone acetylation at SYT1 promoter.

Habitat-specific shaping of proliferation and neuronal differentiation in adult hippocampal neurogenesis of wild rodents

PubMed Central

Cavegn, Nicole; van Dijk, R. Maarten; Menges, Dominik; Brettschneider, Helene; Phalanndwa, Mashudu; Chimimba, Christian T.; Isler, Karin; Lipp, Hans-Peter; Slomianka, Lutz; Amrein, Irmgard

2013-01-01

Daily life of wild mammals is characterized by a multitude of attractive and aversive stimuli. The hippocampus processes complex polymodal information associated with such stimuli and mediates adequate behavioral responses. How newly generated hippocampal neurons in wild animals contribute to hippocampal function is still a subject of debate. Here, we test the relationship between adult hippocampal neurogenesis (AHN) and habitat types. To this end, we compare wild Muridae species of southern Africa [Namaqua rock mouse (Micaelamys namaquensis), red veld rat (Aethomys chrysophilus), highveld gerbil (Tatera brantsii), and spiny mouse (Acomys spinosissimus)] with data from wild European Muridae [long-tailed wood mice (Apodemus sylvaticus), pygmy field mice (Apodemus microps), yellow-necked wood mice (Apodemus flavicollis), and house mice (Mus musculus domesticus)] from previous studies. The pattern of neurogenesis, expressed in normalized numbers of Ki67- and Doublecortin(DCX)-positive cells to total granule cells (GCs), is similar for the species from a southern African habitat. However, we found low proliferation, but high neuronal differentiation in rodents from the southern African habitat compared to rodents from the European environment. Within the African rodents, we observe additional regulatory and morphological traits in the hippocampus. Namaqua rock mice with previous pregnancies showed lower AHN compared to males and nulliparous females. The phylogenetically closely related species (Namaqua rock mouse and red veld rat) show a CA4, which is not usually observed in murine rodents. The specific features of the southern environment that may be associated with the high number of young neurons in African rodents still remain to be elucidated. This study provides the first evidence that a habitat can shape adult neurogenesis in rodents across phylogenetic groups. PMID:23616743

Excretion of Wild-Type and Vaccine-Derived Poliovirus in the Feces of Poliovirus Receptor-Transgenic Mice

PubMed Central

Boot, Hein J.; Kasteel, Daniella T. J.; Buisman, Anne-Marie; Kimman, Tjeerd G.

2003-01-01

The emergence of circulating vaccine-derived poliovirus (cVDPV) strains in suboptimally vaccinated populations is a serious threat to the global poliovirus eradication. The genetic determinants for the transmissibility phenotype of polioviruses, and in particularly of cVDPV strains, are currently unknown. Here we describe the fecal excretion of wild-type poliovirus, oral polio vaccine, and cVDPV (Hispaniola) strains after intraperitoneal injection in poliovirus receptor-transgenic mice. Both the pattern and the level of fecal excretion of the cVDPV strains resemble those of wild-type poliovirus type 1. In contrast, very little poliovirus was present in the feces after oral polio vaccine administration. This mouse model will be helpful in elucidating the genetic determinants for the high fecal-oral transmission phenotype of cVDPV strains. PMID:12743311

Wild-type cells rescue genotypically Math1-null hair cells in the inner ears of chimeric mice.

PubMed

Du, Xiaoping; Jensen, Patricia; Goldowitz, Daniel; Hamre, Kristin M

2007-05-15

The transcription factor Math1 has been shown to be critical in the formation of hair cells (HCs) in the inner ear. However, the influence of environmental factors in HC specification suggests that cell extrinsic factors are also crucial to their development. To test whether extrinsic factors impact development of Math1-null (Math1(beta-Gal/beta-Gal)) HCs, we examined neonatal (postnatal ages P0-P4.5) Math1-null chimeric mice in which genotypically mutant and wild-type cells intermingle to form the inner ear. We provide the first direct evidence that Math1-null HCs are able to be generated and survive in the conducive chimeric environment. beta-Galactosidase expression was used to identify genetically mutant cells while cells were phenotypically defined as HCs by morphological characteristics notably the expression of HC-specific markers. Genotypically mutant HCs were found in all sensory epithelia of the inner ear at all ages examined. Comparable results were obtained irrespective of the wild-type component of the chimeric mice. Thus, genotypically mutant cells retain the competence to differentiate into HCs. The implication is that the lack of the Math1 gene in HC precursors can be overcome by environmental influences, such as cell-cell interactions with wild-type cells, to ultimately result in the formation of HCs.

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.

Wild Type Bone Marrow Transplant Partially Reverses Neuroinflammation in Progranulin-Deficient Mice

PubMed Central

Yang, Yue; Aloi, Macarena S.; Cudaback, Eiron; Josephsen, Samuel R.; Rice, Samantha J.; Jorstad, Nikolas L.; Keene, C. Dirk; Montine, Thomas J.

2014-01-01

Frontotemporal dementia (FTD) is a neurodegenerative disease with devastating changes in behavioral performance and social function. Mutations in the progranulin gene (GRN) are one of the most common causes of inherited FTD due to reduced progranulin expression or activity, including in brain where it is expressed primarily by neurons and microglia. Thus, efforts aimed at enhancing progranulin levels might be a promising therapeutic strategy. Bone marrow-derived cells are able to engraft in the brain and adopt a microglial phenotype under myeloablative irradiation conditioning. This ability makes bone marrow (BM)-derived cells a potential cellular vehicle for transferring therapeutic molecules to the central nervous system. Here, we utilized BM cells from Grn+/+ (wild type or wt) mice labeled with green fluorescence protein for delivery of progranulin to progranulin deficient (Grn−/−) mice. Our results showed that wt bone marrow transplantation (BMT) partially reconstituted progranulin in the periphery and in cerebral cortex of Grn−/− mice. We demonstrated a pro-inflammatory effect in vivo and in ex vivo preparations of cerebral cortex of Grn−/− mice that was partially to fully reversed five months after BMT. Our findings suggest that BMT can be administered as a stem cell-based approach to prevent or to treat neurodegenerative diseases. PMID:25199051

Wild-type bone marrow transplant partially reverses neuroinflammation in progranulin-deficient mice.

PubMed

Yang, Yue; Aloi, Macarena S; Cudaback, Eiron; Josephsen, Samuel R; Rice, Samantha J; Jorstad, Nikolas L; Keene, C Dirk; Montine, Thomas J

2014-11-01

Frontotemporal dementia (FTD) is a neurodegenerative disease with devastating changes in behavioral performance and social function. Mutations in the progranulin gene (GRN) are one of the most common causes of inherited FTD due to reduced progranulin expression or activity, including in brain where it is expressed primarily by neurons and microglia. Thus, efforts aimed at enhancing progranulin levels might be a promising therapeutic strategy. Bone marrow (BM)-derived cells are able to engraft in the brain and adopt a microglial phenotype under myeloablative irradiation conditioning. This ability makes BM-derived cells a potential cellular vehicle for transferring therapeutic molecules to the central nervous system. Here, we utilized BM cells from Grn(+/+) (wild type or wt) mice labeled with green fluorescence protein for delivery of progranulin to progranulin-deficient (Grn(-/-)) mice. Our results showed that wt bone marrow transplantation (BMT) partially reconstituted progranulin in the periphery and in cerebral cortex of Grn(-/-) mice. We demonstrated a pro-inflammatory effect in vivo and in ex vivo preparations of cerebral cortex of Grn(-/-) mice that was partially to fully reversed 5 months after BMT. Our findings suggest that BMT can be administered as a stem cell-based approach to prevent or to treat neurodegenerative diseases.

Differential tumor biology effects of double-initiation in a mouse skin chemical carcinogenesis model comparing wild type versus protein kinase Cepsilon overexpression mice.

PubMed

Li, Yafan; Wheeler, Deric L; Ananthaswamy, Honnavara N; Verma, Ajit K; Oberley, Terry D

2007-12-01

Our previous studies showed that protein kinase Cepsilon (PKCepsilon) verexpression in mouse skin resulted in metastatic squamous cell carcinoma (SCC) elicited by single 7,12-dimethylbenz(a)anthracene (DMBA)-initiation and 12-O-tetradecanoylphorbol-13-acetate (TPA)-promotion in the absence of preceding papilloma formation as is typically observed in wild type mice. The present study demonstrates that double-DMBA initiation modulates tumor incidence, multiplicity, and latency period in both wild type and PKCepsilon overexpression transgenic (PKCepsilon-Tg) mice. After 17 weeks (wks) of tumor promotion, a reduction in papilloma multiplicity was observed in double- versus single-DMBA initiated wild type mice. Papilloma multiplicity was inversely correlated with cell death indices of interfollicular keratinocytes, indicating decreased papilloma formation was caused by increased cell death and suggesting the origin of papillomas is in interfollicular epidermis. Double-initiated PKCepsilon-Tg mice had accelerated carcinoma formation and cancer incidence in comparison to single-initiated PKCepsilon-Tg mice. Morphologic analysis of mouse skin following double initiation and tumor promotion showed a similar if not identical series of events to those previously observed following single initiation and tumor promotion: putative preneoplastic cells were observed arising from hyperplastic hair follicles (HFs) with subsequent cancer cell infiltration into the dermis. Single-initiated PKCepsilon-Tg mice exhibited increased mitosis in epidermal cells of HFs during tumor promotion.

Substance P and central respiratory activity: a comparative in vitro study in NK1 receptor knockout and wild-type mice.

PubMed

Ptak, K; Hunt, S P; Monteau, R

2000-07-01

Neurokinin-1 receptors (NK1) are present within the respiratory medullary network and in the phrenic nucleus, which controls the diaphragm. We compared the efficacy of substance P (SP) at inducing changes in respiratory frequency or the amplitude of the respiratory motor output between NK1 knockout (NK1-/-) and wild-type mice, using the in vitro brainstem-spinal cord preparation. The in vitro respiratory frequency, as well as the variability of the rhythm and the amplitude of the motor output were similar in both lines. In wild-type mice, application of exogenous SP induced either an increase in respiratory frequency (superfusion of the medulla) or an increase of the inspiratory motor output, as defined by the integral of C4 cervical ventral root activity (superfusion of the spinal cord). These two effects were not apparent in NK1-/- mice. In conclusion, NK1 receptors mediate the respiratory responses to SP but the lack of NK1 receptors in newborn NK1-/- mice does not change the respiratory activity.

The effect of mild traumatic brain injury on peripheral nervous system pathology in wild-type mice and the G93A mutant mouse model of motor neuron disease.

PubMed

Evans, T M; Jaramillo, C A; Sataranatarajan, K; Watts, L; Sabia, M; Qi, W; Van Remmen, H

2015-07-09

Traumatic brain injury (TBI) is associated with a risk of neurodegenerative disease. Some suggest a link between TBI and motor neuron disease (MND), including amyotrophic lateral sclerosis (ALS). To investigate the potential mechanisms linking TBI to MND, we measured motor function and neuropathology following mild-TBI in wild-type and a transgenic model of ALS, G93A mutant mice. Mild-TBI did not alter the lifespan of G93A mice or age of onset; however, rotarod performance was impaired in G93A verses wild-type mice. Grip strength was reduced only in G93A mice after mild-TBI. Increased electromyography (EMG) abnormalities and markers of denervation (AchR, Runx1) indicate that mild-TBI may result in peripheral effects that are exaggerated in G93A mice. Markers of inflammation (cell edema, astrogliosis and microgliosis) were detected at 24 and 72h in the brain and spinal cord in wild-type and G93A mice. Levels of F2-isoprostanes, a marker of oxidative stress, were increased in the spinal cord 24h post mild-TBI in wild-type mice but were not affected by TBI in G93A mice. In summary, our data demonstrate that mild-TBI induces inflammation and oxidative stress and negatively impacts muscle denervation and motor performance, suggesting mild-TBI can potentiate motor neuron pathology and influence the development of MND in mice. Published by Elsevier Ltd.

Peptide Transporter 1 is Responsible for Intestinal Uptake of the Dipeptide Glycylsarcosine: Studies in Everted Jejunal Rings from Wild-type and Pept1 Null Mice

PubMed Central

Ma, Katherine; Hu, Yongjun; Smith, David E.

2010-01-01

The purpose of this study was to determine the relative importance of PEPT1 in the uptake of peptides/mimetics from mouse small intestine using glycylsarcosine (GlySar). After isolating jejunal tissue from wild-type and Pept1 null mice, 2-cm intestinal segments were everted and mounted on glass rods for tissue uptake studies. [14C]GlySar (4 μM) was studied as a function of time, temperature, sodium and pH, concentration, and potential inhibitors. Compared to wild-type animals, Pept1 null mice exhibited a 78% reduction of GlySar uptake at pH 6.0, 37°C. GlySar uptake showed pH dependence with peak values between pH 6.0-6.5 in wild-type animals, while no such tendency was observed in Pept1 null mice. GlySar exhibited Michaelis-Menten uptake kinetics and a minor nonsaturable component in wild-type animals. In contrast, GlySar uptake occurred by only a nonsaturable process in Pept1 null mice. GlySar uptake was significantly inhibited by dipeptides, aminocephalosporins, angiotensin-converting enzyme inhibitors, and the antiviral prodrug valacyclovir; these inhibitors had little, if any, effect on the uptake of GlySar in Pept1 null mice. The findings demonstrate that PEPT1 plays a critical role in the uptake of GlySar in jejunum, and suggest that PEPT1 is the major transporter responsible for the intestinal absorption of small peptides. PMID:20862774

A comparison of GluR-A-deficient and wild-type mice on a test battery assessing sensorimotor, affective, and cognitive behaviors.

PubMed

Bannerman, D M; Deacon, R M J; Brady, S; Bruce, A; Sprengel, R; Seeburg, P H; Rawlins, J N P

2004-06-01

Previous studies have demonstrated a spatial working memory deficit in glutamate receptor (GluR)-A (GluR1) AMPA receptor subunit knockout mice. The present study evaluated male and female wild-type and GluR-A-/- mice on a test battery that assessed sensorimotor, affective, and cognitive behaviors. Results revealed a behavioral phenotype more extensive than previously described. GluR-A-/- mice were hyperactive, displayed a subtle lack of motor coordination, and were generally more anxious than wild-type controls. In addition, they showed a deficit in spontaneous alternation, consistent with previous reports of a role for GluR-A-dependent plasticity in hippocampus-dependent, spatial working memory. Although changes in motor coordination or anxiety cannot explain the dissociations already reported within the spatial memory domain, it is clear that they could significantly affect interpretation of results obtained in other kinds of behavioral tasks. ((c) 2004 APA, all rights reserved)

Significance of Peptide Transporter 1 in the Intestinal Permeability of Valacyclovir in Wild-Type and PepT1 Knockout Mice

PubMed Central

Yang, Bei

2013-01-01

The purpose of this study was to quantitatively determine the contribution of PepT1 [peptide transporter 1 (SLC15A1)] to the intestinal permeability of valacyclovir, an ester prodrug of the antiviral drug acyclovir. In situ single-pass intestinal perfusions were employed (pH 6.5 × 90 minutes) to assess the effective permeability (Peff) of 100 μM [3H]valacyclovir in wild-type and PepT1 knockout mice. Acyclovir pharmacokinetics was also evaluated after oral administration of 25 nmol/g valacyclovir. In wild-type mice, jejunal uptake of valacyclovir was best described by both saturable (Km = 10.2 mM) and nonsaturable components where the saturable pathway accounted for 82% of total transport. Valacyclovir Peff was 2.4 × 10−4 cm/s in duodenum, 1.7 × 10−4 cm/s in jejunum, 2.1 × 10−4 cm/s in ileum, and 0.27 × 10−4 cm/s in colon. In Pept1 knockout mice, Peff values were about 10% of that in wild-type animals for these small intestinal segments. Valacyclovir Peff was similar in the colon of both genotypes. There were no differences in valacyclovir Peff between any of the intestinal segments of PepT1 knockout mice. Valacyclovir Peff was significantly reduced by the dipeptide glycylsarcosine and the aminocephalosporin cefadroxil, but not by the amino acids l-valine or l-histidine, the organic acid p-aminohippurate, or the organic base tetraethylammonium (all at 25 mM). PepT1 ablation resulted in 3- to 5-fold reductions in the in vivo rate and extent of valacyclovir absorption. Our findings conclusively demonstrate, using in situ and in vivo validations in genetically modified mice, that PepT1 has a major influence in improving the oral absorption of valacyclovir. PMID:23264448

Low-Pathogenic Avian Influenza Viruses in Wild House Mice

PubMed Central

Shriner, Susan A.; VanDalen, Kaci K.; Mooers, Nicole L.; Ellis, Jeremy W.; Sullivan, Heather J.; Root, J. Jeffrey; Pelzel, Angela M.; Franklin, Alan B.

2012-01-01

Background Avian influenza viruses are known to productively infect a number of mammal species, several of which are commonly found on or near poultry and gamebird farms. While control of rodent species is often used to limit avian influenza virus transmission within and among outbreak sites, few studies have investigated the potential role of these species in outbreak dynamics. Methodology/Principal Findings We trapped and sampled synanthropic mammals on a gamebird farm in Idaho, USA that had recently experienced a low pathogenic avian influenza outbreak. Six of six house mice (Mus musculus) caught on the outbreak farm were presumptively positive for antibodies to type A influenza. Consequently, we experimentally infected groups of naïve wild-caught house mice with five different low pathogenic avian influenza viruses that included three viruses derived from wild birds and two viruses derived from chickens. Virus replication was efficient in house mice inoculated with viruses derived from wild birds and more moderate for chicken-derived viruses. Mean titers (EID50 equivalents/mL) across all lung samples from seven days of sampling (three mice/day) ranged from 103.89 (H3N6) to 105.06 (H4N6) for the wild bird viruses and 102.08 (H6N2) to 102.85 (H4N8) for the chicken-derived viruses. Interestingly, multiple regression models indicated differential replication between sexes, with significantly (p<0.05) higher concentrations of avian influenza RNA found in females compared with males. Conclusions/Significance Avian influenza viruses replicated efficiently in wild-caught house mice without adaptation, indicating mice may be a risk pathway for movement of avian influenza viruses on poultry and gamebird farms. Differential virus replication between males and females warrants further investigation to determine the generality of this result in avian influenza disease dynamics. PMID:22720076

The effect of nitric oxide synthase inhibitors nitro-L-arginine and 7-nitroindazole on spatial learning and motor functions in Lurcher mutant and wild type mice.

PubMed

Markvartová, V; Vozeh, F

2008-01-01

Nitric oxide (NO) is an intercellular messenger that, among other things, plays an important role in the nervous system as a gaseous neurotransmitter, modulating long-term potentiation (LTP) induction of synaptic transmission. LTP has been suggested to be the basis of memory formation. On the other hand NO also participates in excitotoxic processes which play an important role in many neuropathological states. The aim of this work was to observe the effect of two NO synthase (NOS) inhibitors (N omega-Nitro-L-arginine, NA; 7-nitroindazole, NI) on spontaneous behaviour, spatial learning and motor functions in Lurcher (+/Lc) and wild type (+/+) mice, derived from the B6CBA strain. Heterozygous Lurcher mutant mice represent a natural model of the olivocerebellar degeneration. They suffer from postnatal, practically total, extinction of cerebellar Purkinje cells (due to the excitotoxic apoptosis) and a partial decrease of granule cells and inferior olive neurons (ION) because of the lost target of their axons. +/+ animals are healthy littermates of +/Lc. NA is a nonselective NOS inhibitor which influences, except neuronal (n), also endothelial (e) NOS with an impact on blood pressure, NI is a selective nNOS inhibitor without any circulatory effect. The adult animals of both types (+/Lc; +/+) were influenced by acute administration of both inhibitors (25 mg/kg i.p. 30 min. before experiments) and newborns only by both acute and long-term administration of NI (1 month, starting from postnatal day 2, P2). Control solutions - saline or solvents of both NA and NI inhibitors--diluted 1M HCl and dimethyl sulfoxide (DMSO) respectively, were given at a relevant volume in the same way. The effect of both inhibitors and control solutions on motor functions was tested using four standard procedures (horizontal wire, slanting ladder, rotating cylinder, foot-bridge); in newborns at the age of 14 days. Spatial learning ability was examined in five-day long procedure in the Morris

Differential effects of silver nanoparticles on DNA damage and DNA repair gene expression in Ogg1-deficient and wild type mice.

PubMed

Nallanthighal, Sameera; Chan, Cadia; Murray, Thomas M; Mosier, Aaron P; Cady, Nathaniel C; Reliene, Ramune

2017-10-01

Due to extensive use in consumer goods, it is important to understand the genotoxicity of silver nanoparticles (AgNPs) and identify susceptible populations. 8-Oxoguanine DNA glycosylase 1 (OGG1) excises 8-oxo-7,8-dihydro-2-deoxyguanine (8-oxoG), a pro-mutagenic lesion induced by oxidative stress. To understand whether defects in OGG1 is a possible genetic factor increasing an individual's susceptibly to AgNPs, we determined DNA damage, genome rearrangements, and expression of DNA repair genes in Ogg1-deficient and wild type mice exposed orally to 4 mg/kg of citrate-coated AgNPs over a period of 7 d. DNA damage was examined at 3 and 7 d of exposure and 7 and 14 d post-exposure. AgNPs induced 8-oxoG, double strand breaks (DSBs), chromosomal damage, and DNA deletions in both genotypes. However, 8-oxoG was induced earlier in Ogg1-deficient mice and 8-oxoG levels were higher after 7-d treatment and persisted longer after exposure termination. AgNPs downregulated DNA glycosylases Ogg1, Neil1, and Neil2 in wild type mice, but upregulated Myh, Neil1, and Neil2 glycosylases in Ogg1-deficient mice. Neil1 and Neil2 can repair 8-oxoG. Thus, AgNP-mediated downregulation of DNA glycosylases in wild type mice may contribute to genotoxicity, while upregulation thereof in Ogg1-deficient mice could serve as an adaptive response to AgNP-induced DNA damage. However, our data show that Ogg1 is indispensable for the efficient repair of AgNP-induced damage. In summary, citrate-coated AgNPs are genotoxic in both genotypes and Ogg1 deficiency exacerbates the effect. These data suggest that humans with genetic polymorphisms and mutations in OGG1 may have increased susceptibility to AgNP-mediated DNA damage.

Chikungunya Virus Arthritis in Adult Wild-Type Mice▿ †

PubMed Central

Gardner, Joy; Anraku, Itaru; Le, Thuy T.; Larcher, Thibaut; Major, Lee; Roques, Pierre; Schroder, Wayne A.; Higgs, Stephen; Suhrbier, Andreas

2010-01-01

Chikungunya virus is a mosquito-borne arthrogenic alphavirus that has recently reemerged to produce the largest epidemic ever documented for this virus. Here we describe a new adult wild-type mouse model of chikungunya virus arthritis, which recapitulates the self-limiting arthritis, tenosynovitis, and myositis seen in humans. Rheumatic disease was associated with a prolific infiltrate of monocytes, macrophages, and NK cells and the production of monocyte chemoattractant protein 1 (MCP-1), tumor necrosis factor alpha (TNF-α), and gamma interferon (IFN-γ). Infection with a virus isolate from the recent Reunion Island epidemic induced significantly more mononuclear infiltrates, proinflammatory mediators, and foot swelling than did an Asian isolate from the 1960s. Primary mouse macrophages were shown to be productively infected with chikungunya virus; however, the depletion of macrophages ameliorated rheumatic disease and prolonged the viremia. Only 1 μg of an unadjuvanted, inactivated, whole-virus vaccine derived from the Asian isolate completely protected against viremia and arthritis induced by the Reunion Island isolate, illustrating that protection is not strain specific and that low levels of immunity are sufficient to mediate protection. IFN-α treatment was able to prevent arthritis only if given before infection, suggesting that IFN-α is not a viable therapy. Prior infection with Ross River virus, a related arthrogenic alphavirus, and anti-Ross River virus antibodies protected mice against chikungunya virus disease, suggesting that individuals previously exposed to Ross River virus should be protected from chikungunya virus disease. This new mouse model of chikungunya virus disease thus provides insights into pathogenesis and a simple and convenient system to test potential new interventions. PMID:20519386

Differences in Ultrasonic Vocalizations between Wild and Laboratory California Mice (Peromyscus californicus)

PubMed Central

Kalcounis-Rueppell, Matina C.; Petric, Radmila; Briggs, Jessica R.; Carney, Catherine; Marshall, Matthew M.; Willse, John T.; Rueppell, Olav; Ribble, David O.; Crossland, Janet P.

2010-01-01

Background Ultrasonic vocalizations (USVs) emitted by muroid rodents, including laboratory mice and rats, are used as phenotypic markers in behavioral assays and biomedical research. Interpretation of these USVs depends on understanding the significance of USV production by rodents in the wild. However, there has never been a study of muroid rodent ultrasound function in the wild and comparisons of USVs produced by wild and laboratory rodents are lacking to date. Here, we report the first comparison of wild and captive rodent USVs recorded from the same species, Peromyscus californicus. Methodology and Principal Findings We used standard ultrasound recording techniques to measure USVs from California mice in the laboratory (Peromyscus Genetic Stock Center, SC, USA) and the wild (Hastings Natural History Reserve, CA, USA). To determine which California mouse in the wild was vocalizing, we used a remote sensing method that used a 12-microphone acoustic localization array coupled with automated radio telemetry of all resident Peromyscus californicus in the area of the acoustic localization array. California mice in the laboratory and the wild produced the same types of USV motifs. However, wild California mice produced USVs that were 2–8 kHz higher in median frequency and significantly more variable in frequency than laboratory California mice. Significance The similarity in overall form of USVs from wild and laboratory California mice demonstrates that production of USVs by captive Peromyscus is not an artifact of captivity. Our study validates the widespread use of USVs in laboratory rodents as behavioral indicators but highlights that particular characteristics of laboratory USVs may not reflect natural conditions. PMID:20368980

Dietary Supplementation of Hericium erinaceus Increases Mossy Fiber-CA3 Hippocampal Neurotransmission and Recognition Memory in Wild-Type Mice

PubMed Central

Cesaroni, Valentina; Gregori, Andrej; Repetti, Margherita; Romano, Chiara; Orrù, Germano; Botta, Laura; Girometta, Carolina; Guglielminetti, Maria Lidia; Savino, Elena

2017-01-01

Hericium erinaceus (Bull.) Pers. is a medicinal mushroom capable of inducing a large number of modulatory effects on human physiology ranging from the strengthening of the immune system to the improvement of cognitive functions. In mice, dietary supplementation with H. erinaceus prevents the impairment of spatial short-term and visual recognition memory in an Alzheimer model. Intriguingly other neurobiological effects have recently been reported like the effect on neurite outgrowth and differentiation in PC12 cells. Until now no investigations have been conducted to assess the impact of this dietary supplementation on brain function in healthy subjects. Therefore, we have faced the problem by considering the effect on cognitive skills and on hippocampal neurotransmission in wild-type mice. In wild-type mice the oral supplementation with H. erinaceus induces, in behaviour test, a significant improvement in the recognition memory and, in hippocampal slices, an increase in spontaneous and evoked excitatory synaptic current in mossy fiber-CA3 synapse. In conclusion, we have produced a series of findings in support of the concept that H. erinaceus induces a boost effect onto neuronal functions also in nonpathological conditions. PMID:28115973

Dietary Supplementation of Hericium erinaceus Increases Mossy Fiber-CA3 Hippocampal Neurotransmission and Recognition Memory in Wild-Type Mice.

PubMed

Brandalise, Federico; Cesaroni, Valentina; Gregori, Andrej; Repetti, Margherita; Romano, Chiara; Orrù, Germano; Botta, Laura; Girometta, Carolina; Guglielminetti, Maria Lidia; Savino, Elena; Rossi, Paola

2017-01-01

Hericium erinaceus (Bull.) Pers. is a medicinal mushroom capable of inducing a large number of modulatory effects on human physiology ranging from the strengthening of the immune system to the improvement of cognitive functions. In mice, dietary supplementation with H. erinaceus prevents the impairment of spatial short-term and visual recognition memory in an Alzheimer model. Intriguingly other neurobiological effects have recently been reported like the effect on neurite outgrowth and differentiation in PC12 cells. Until now no investigations have been conducted to assess the impact of this dietary supplementation on brain function in healthy subjects. Therefore, we have faced the problem by considering the effect on cognitive skills and on hippocampal neurotransmission in wild-type mice. In wild-type mice the oral supplementation with H. erinaceus induces, in behaviour test, a significant improvement in the recognition memory and, in hippocampal slices, an increase in spontaneous and evoked excitatory synaptic current in mossy fiber-CA3 synapse. In conclusion, we have produced a series of findings in support of the concept that H. erinaceus induces a boost effect onto neuronal functions also in nonpathological conditions.

Molecular Characterization of Wild Type Measles Virus from Adult Patients in Northern China, 2014.

PubMed

Xu, Wen; Zhang, Ming-Xiang; Qin, En-Qiang; Yan, Ying-Chun; Li, Feng-Yi; Xu, Zhe; Tian, Xia; Fan, Rong; Tu, Bo; Chen, Wei-Wei; Zhao, Min

2016-04-01

In this study, we studied the N and H genes from wild type measles viruses (MeVs) isolated during the 2013-2014 outbreak. Clinical samples were collected, and the genotyping, phylogenetic analysis were performed. The vaccination rate of the study population was 4%. Genotype H1a was the predominant genotype. Wild type viruses were classified into clusters A and B, C and may have different origins. N-450 sequences from wild type viruses were highly homologous with, and likely evolved from MeVs circulating in Tianjing and Henan in 2012. MVs/Shenyang.CHN/18.14/3 could have evolved from MeVs from Liaoning, Beijing, Hebei, Heilongjiang, Henan, Jilin, and Tianjin. Our data suggested that one or more of the same viruses circulated between Beijing, Shenyang, Hong Kong, Taiwan and Berlin. Important factors contributing to outbreaks could include weak vaccination coverage, poor vaccination strategies, and migration of adult workers between cities, countries, and from rural areas to urban areas. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

Exploration and risk assessment in female wild house mice (Mus musculus musculus) and two laboratory strains.

PubMed

Augustsson, Hanna; Dahlborn, Kristina; Meyerson, Bengt J

2005-02-15

In an evolutionary prospective, it is possible that female mice have a differential perception of novel events than male mice and use a different behavioural strategy for risk assessment. However, female mice are less studied than male mice in behavioural tests of emotional reactivity. The aim of the present study was to investigate how wild-derived female house mice differ from domesticated female mice in their risk assessment strategy. A total of 46 adult female mice, 14 BALB/c, 16 C57BL/6 and 14 Wild mice were tested in the Concentric Square Field (CSF), Open Field (OF) and Elevated Plus Maze (EPM) at three consecutive days. Parameters from all three tests were categorized according to their relevance to activity, exploration, approach-avoidance and use of open areas-shelter. Principal Component Analysis (PCA-SIMCA) of the animals' behaviour in the CSF arena was performed both for females alone and in comparison with earlier findings in male mice under the same test conditions. The results clearly show that female wild mice had a higher avoidance of open areas than the laboratory strains. There was also a trend indicating differences in exploration and approach-avoidance between female Wild and the laboratory strains. The multivariate test, CSF, was able to detect differences between Wild and laboratory strains in three (exploration, approach-avoidance, open-shelter) of the four functional categories measured. Wild female mice also had a higher frequency of rearing and grooming and a lower duration in the corridors in the CSF. Clear strain differences were found between BALB and C57BL in all tests where BALB generally had higher risk assessment and lower risk taking than C57BL. No general sex differences were found, however the sex differences were greater in Wild mice compared to the laboratory strains.

Spontaneous generation of rapidly transmissible prions in transgenic mice expressing wild-type bank vole prion protein.

PubMed

Watts, Joel C; Giles, Kurt; Stöhr, Jan; Oehler, Abby; Bhardwaj, Sumita; Grillo, Sunny K; Patel, Smita; DeArmond, Stephen J; Prusiner, Stanley B

2012-02-28

Currently, there are no animal models of the most common human prion disorder, sporadic Creutzfeldt-Jakob disease (CJD), in which prions are formed spontaneously from wild-type (WT) prion protein (PrP). Interestingly, bank voles (BV) exhibit an unprecedented promiscuity for diverse prion isolates, arguing that bank vole PrP (BVPrP) may be inherently prone to adopting misfolded conformations. Therefore, we constructed transgenic (Tg) mice expressing WT BVPrP. Tg(BVPrP) mice developed spontaneous CNS dysfunction between 108 and 340 d of age and recapitulated the hallmarks of prion disease, including spongiform degeneration, pronounced astrogliosis, and deposition of alternatively folded PrP in the brain. Brain homogenates of ill Tg(BVPrP) mice transmitted disease to Tg(BVPrP) mice in ∼35 d, to Tg mice overexpressing mouse PrP in under 100 d, and to WT mice in ∼185 d. Our studies demonstrate experimentally that WT PrP can spontaneously form infectious prions in vivo. Thus, Tg(BVPrP) mice may be useful for studying the spontaneous formation of prions, and thus may provide insight into the etiology of sporadic CJD.

Inbred Strain-Specific Effects of Exercise in Wild Type and Biglycan Deficient Mice

PubMed Central

Wallace, Joseph M.; Golcuk, Kurtulus; Morris, Michael D.; Kohn, David H.

2010-01-01

Biglycan (bgn)-deficient mice (KO) have defective osteoblasts which lead to changes in the amount and quality of bone. Altered tissue strength in C57BL6/129 (B6;129) KO mice, a property which is independent of tissue quantity, suggests that deficiencies in tissue quality are responsible. However, the response to bgn-deficiency is inbred strain-specific. Mechanical loading influences bone matrix quality in addition to any increase in bone mass or change in bone formation activity. Since many diseases influence the mechanical integrity of bone through altered tissue quality, loading may be a way to prevent and treat extracellular matrix deficiencies. C3H/He (C3H) mice consistently have a less vigorous response to mechanical loading vs. other inbred strains. It was therefore hypothesized that the bones from both wild type (WT) and KO B6;129 mice would be more responsive to exercise than the bones from C3H mice. To test these hypotheses at 11 weeks of age, following 21 consecutive days of exercise, we investigated cross-sectional geometry, mechanical properties, and tissue composition in the tibiae of male mice bred on B6;129 and C3H backgrounds. This study demonstrated inbred strain-specific compositional and mechanical changes following exercise in WT and KO mice, and showed evidence of genotype-specific changes in bone in response to loading in a gene disruption model. This study further shows that exercise can influence bone tissue composition and/or mechanical integrity without changes in bone geometry. Together, these data suggest that exercise may represent a possible means to alter tissue quality and mechanical deficiencies caused by many diseases of bone. PMID:20033775

Activation Of Wild-Type Hras Suppresses The Earliest Stages Of Pancreatic Cancer.

PubMed

Weyandt, Jamie

2015-08-01

The RAS family of small GTPases is comprised of HRAS, NRAS, and KRAS. KRAS is invariably oncogenically mutated in pancreatic cancers, which is known to induce this disease. Beyond oncogenic KRAS, redox-dependent reactions have been implicated in the activation of the remaining wild-type RAS proteins in pancreatic cancer cell lines. These results suggest a possible involvement of wild-type RAS proteins in pancreatic cancer. To evaluate the impact of genetically suppressing wild-type RAS expression on pancreatic cancer. Hras homozygous null mice (Hras -/- ) were crossed into a Pdx-Cre; LSL-Kras G12D/+ (KC) murine background in which oncogenic Kras is activated in the pancreas to promote preinvasive pancreatic cancer. Tumor burden was then measured at different stages of disease. HRas -/- ;KC mice exhibited more precancerous lesions in the pancreas and more off-target skin papillomas compared to their wild-type counterparts, suggesting that Hras suppresses early oncogenic Kras-driven tumorigenesis, possibly at the time of initiation. Loss of Hras also reduced the survival of mice engineered to develop aggressive pancreatic cancer by the additional disruption of one allele of the tumor suppressor p53 (Trp53 R172H/+ ). However, this survival advantage was lost when both alleles of Trp53 were mutated, suggesting that wild-type Hras inhibits tumorigenesis in a p53-dependent fashion. Loss of wild-type Hras promotes the earliest stages of pancreatic tumorigenesis, and moreover results in more rapid progression of the disease. As such, mechanisms leading to activation of wild-type Ras proteins, including but not limited to redox-dependent reactions, may influence the development of pancreatic cancer. Copyright © 2015. Published by Elsevier B.V.

Early and progressive sensorimotor anomalies in mice overexpressing wild-type human alpha-synuclein.

PubMed

Fleming, Sheila M; Salcedo, Jonathan; Fernagut, Pierre-Olivier; Rockenstein, Edward; Masliah, Eliezer; Levine, Michael S; Chesselet, Marie-Françoise

2004-10-20

Accumulation of alpha-synuclein in brain is a hallmark of synucleinopathies, neurodegenerative diseases that include Parkinson's disease. Mice overexpressing alpha-synuclein under the Thy-1 promoter (ASO) show abnormal accumulation of alpha-synuclein in cortical and subcortical regions of the brain, including the substantia nigra. We examined the motor deficits in ASO mice with a battery of sensorimotor tests that are sensitive to alterations in the nigrostriatal dopaminergic system. Male wild-type and ASO mice were tested every 2 months for 8 months for motor performance and coordination on a challenging beam, inverted grid, and pole, sensorimotor deficits in an adhesive removal test, spontaneous activity in a cylinder, and gait. Fine motor skills were assessed by the ability to grasp cotton from a bin. ASO mice displayed significant impairments in motor performance and coordination and a reduction in spontaneous activity as early as 2 months of age. Motor performance and coordination impairments became progressively worse with age and sensorimotor deficits appeared at 6 months. Fine motor skills were altered at 4 months and worsened at 8 months. These data indicate that overexpression of alpha-synuclein induced an early and progressive behavioral phenotype that can be detected in multiple tests of sensorimotor function. These behavioral deficits provide a useful way to assess novel drug therapy in genetic models of synucleinopathies.

GENETIC CATHEPSIN B DEFICIENCY REDUCES β-AMYLOID IN TRANSGENIC MICE EXPRESSING HUMAN WILD-TYPE AMYLOID PRECURSOR PROTEIN

PubMed Central

Hook, Vivian Y. H.; Kindy, Mark; Reinheckel, Thomas; Peters, Christoph; Hook, Gregory

2009-01-01

Neurotoxic β-amyloid (Aβ) peptides participate in Alzheimer’s disease (AD); therefore, reduction of Aβ generated from APP may provide a therapeutic approach for AD. Gene knockout studies in transgenic mice producing human Aβ may identify targets for reducing Aβ. This study shows that knockout of the cathepsin B gene in mice expressing human wild-type APP (hAPPwt) results in substantial decrease of Aβ40 and Aβ42 by 67% in brain, and decreases levels of the C-terminal β-secretase fragment (CTFβ) derived from APP. In contrast, knockout of cathepsin B in mice expressing hAPP with the rare Swedish (Swe) and Indiana (Ind) mutations had no effect on Aβ. The difference in reduction of Aβ in hAPPwt mice, but not in hAPPSwe/Ind mice, shows that the transgenic model can affect cathepsin B gene knockout results. Since most AD patients express hAPPwt, these data validate cathepsin B as a target for development of inhibitors to lower Aβ in AD. PMID:19501042

Genetic cathepsin B deficiency reduces beta-amyloid in transgenic mice expressing human wild-type amyloid precursor protein.

PubMed

Hook, Vivian Y H; Kindy, Mark; Reinheckel, Thomas; Peters, Christoph; Hook, Gregory

2009-08-21

Neurotoxic beta-amyloid (Abeta) peptides participate in Alzheimer's disease (AD); therefore, reduction of Abeta generated from APP may provide a therapeutic approach for AD. Gene knockout studies in transgenic mice producing human Abeta may identify targets for reducing Abeta. This study shows that knockout of the cathepsin B gene in mice expressing human wild-type APP (hAPPwt) results in substantial decreases in brain Abeta40 and Abeta42 by 67% and decreases in levels of the C-terminal beta-secretase fragment (CTFbeta) derived from APP. In contrast, knockout of cathepsin B in mice expressing hAPP with the rare Swedish (Swe) and Indiana (Ind) mutations had no effect on Abeta. The difference in reduction of Abeta in hAPPwt mice, but not in hAPPSwe/Ind mice, shows that the transgenic model can affect cathepsin B gene knockout results. Since most AD patients express hAPPwt, these data validate cathepsin B as a target for development of inhibitors to lower Abeta in AD.

Reductions in expression of growth regulating genes in skeletal muscle with age in wild type and myostatin null mice.

PubMed

Jones, Jennifer C; Kroscher, Kellie A; Dilger, Anna C

2014-03-28

Genes that decline in expression with age and are thought to coordinate growth cessation have been identified in various organs, but their expression in skeletal muscle is unknown. Therefore, our objective was to determine expression of these genes (Ezh2, Gpc3, Mdk, Mest, Mycn, Peg3, and Plagl1) in skeletal muscle from birth to maturity. We hypothesized that expression of these genes would decline with age in skeletal muscle but differ between sexes and between wild type and myostatin null mice. Female and male wild type and myostatin null mice (C57BL/6J background) were sacrificed by carbon dioxide asphyxiation followed by decapitation at d -7, 0, 21, 42, and 70 days of age. Whole bodies at d -7, all muscles from both hind limbs at d 0, and bicep femoris muscle from d 21, 42 and 70 were collected. Gene expression was determined by quantitative real-time PCR. In general, expression of these growth-regulating genes was reduced at d 21 compared with day 0 and d -7. Expression of Gpc3, Mest, and Peg3 was further reduced at d 42 and 70 compared with d 21, however the expression of Mycn increased from d 21 to d 42 and 70. Myostatin null mice, as expected, were heavier with increased biceps femoris weight at d 70. However, with respect to sex and genotype, there were few differences in expression. Expression of Ezh2 was increased at d 70 and expression of Mdk was increased at d 21 in myostatin null mice compared with wild type, but no other genotype effects were present. Expression of Mdk was increased in females compared to males at d 70, but no other sex effects were present. Overall, these data suggest the downregulation of these growth-regulating genes with age might play a role in the coordinated cessation of muscle growth similar to organ growth but likely have a limited role in the differences between sexes or genotypes.

Consequences of long-term oral administration of the mitochondria-targeted antioxidant MitoQ to wild-type mice.

PubMed

Rodriguez-Cuenca, Sergio; Cochemé, Helena M; Logan, Angela; Abakumova, Irina; Prime, Tracy A; Rose, Claudia; Vidal-Puig, Antonio; Smith, Anthony C; Rubinsztein, David C; Fearnley, Ian M; Jones, Bruce A; Pope, Simon; Heales, Simon J R; Lam, Brian Y H; Neogi, Sudeshna Guha; McFarlane, Ian; James, Andrew M; Smith, Robin A J; Murphy, Michael P

2010-01-01

The mitochondria-targeted quinone MitoQ protects mitochondria in animal studies of pathologies in vivo and is being developed as a therapy for humans. However, it is unclear whether the protective action of MitoQ is entirely due to its antioxidant properties, because long-term MitoQ administration may alter whole-body metabolism and gene expression. To address this point, we administered high levels of MitoQ orally to wild-type C57BL/6 mice for up to 28 weeks and investigated the effects on whole-body physiology, metabolism, and gene expression, finding no measurable deleterious effects. In addition, because antioxidants can act as pro-oxidants under certain conditions in vitro, we examined the effects of MitoQ administration on markers of oxidative damage. There were no changes in the expression of mitochondrial or antioxidant genes as assessed by DNA microarray analysis. There were also no increases in oxidative damage to mitochondrial protein, DNA, or cardiolipin, and the activities of mitochondrial enzymes were unchanged. Therefore, MitoQ does not act as a pro-oxidant in vivo. These findings indicate that mitochondria-targeted antioxidants can be safely administered long-term to wild-type mice. Copyright 2009 Elsevier Inc. All rights reserved.

Epidermal growth factor receptor plays a role in the regulation of liver and plasma lipid levels in adult male mice.

PubMed

Scheving, Lawrence A; Zhang, Xiuqi; Garcia, Oscar A; Wang, Rebecca F; Stevenson, Mary C; Threadgill, David W; Russell, William E

2014-03-01

Dsk5 mice have a gain of function in the epidermal growth factor receptor (EGFR), caused by a point mutation in the kinase domain. We analyzed the effect of this mutation on liver size, histology, and composition. We found that the livers of 12-wk-old male Dsk5 heterozygotes (+/Dsk5) were 62% heavier compared with those of wild-type controls (+/+). The livers of the +/Dsk5 mice compared with +/+ mice had larger hepatocytes with prominent, polyploid nuclei and showed modestly increased cell proliferation indices in both hepatocytes and nonparenchymal cells. An analysis of total protein, DNA, and RNA (expressed relative to liver weight) revealed no differences between the mutant and wild-type mice. However, the livers of the +/Dsk5 mice had more cholesterol but less phospholipid and fatty acid. Circulating cholesterol levels were twice as high in adult male +/Dsk5 mice but not in postweaned young male or female mice. The elevated total plasma cholesterol resulted mainly from an increase in low-density lipoprotein (LDL). The +/Dsk5 adult mouse liver expressed markedly reduced protein levels of LDL receptor, no change in proprotein convertase subtilisin/kexin type 9, and a markedly increased fatty acid synthase and 3-hydroxy-3-methyl-glutaryl-CoA reductase. Increased expression of transcription factors associated with enhanced cholesterol synthesis was also observed. Together, these findings suggest that the EGFR may play a regulatory role in hepatocyte proliferation and lipid metabolism in adult male mice, explaining why elevated levels of EGF or EGF-like peptides have been positively correlated to increased cholesterol levels in human studies.

Differential proteomic and behavioral effects of long-term voluntary exercise in wild-type and APP-overexpressing transgenics.

PubMed

Rao, Shailaja Kishan; Ross, Jordan M; Harrison, Fiona E; Bernardo, Alexandra; Reiserer, Randall S; Reiserer, Ronald S; Mobley, James A; McDonald, Michael P

2015-06-01

Physical exercise may provide protection against the cognitive decline and neuropathology associated with Alzheimer's disease, although the mechanisms are not clear. In the present study, APP/PSEN1 double-transgenic and wild-type mice were allowed unlimited voluntary exercise for 7months. Consistent with previous reports, wheel-running improved cognition in the double-transgenic mice. Interestingly, the average daily distance run was strongly correlated with spatial memory in the water maze in wild-type mice (r(2)=.959), but uncorrelated in transgenics (r(2)=.013). Proteomics analysis showed that sedentary transgenic mice differed significantly from sedentary wild-types with respect to proteins involved in synaptic transmission, cytoskeletal regulation, and neurogenesis. When given an opportunity to exercise, the transgenics' deficiencies in cytoskeletal regulation and neurogenesis largely normalized, but abnormal synaptic proteins did not change. In contrast, exercise enhanced proteins associated with cytoskeletal regulation, oxidative phosphorylation, and synaptic transmission in wild-type mice. Soluble and insoluble Aβ40 and Aβ42 levels were significantly decreased in both cortex and hippocampus of active transgenics, suggesting that this may have played a role in the cognitive improvement in APP/PSEN1 mice. β-secretase was significantly reduced in active APP/PSEN1 mice compared to sedentary controls, suggesting a mechanism for reduced Aβ. Taken together, these data illustrate that exercise improves memory in wild-type and APP-overexpressing mice in fundamentally different ways. Copyright © 2015 Elsevier Inc. All rights reserved.

Attenuated Stress Response to Acute Restraint and Forced Swimming Stress in Arginine Vasopressin 1b Receptor Subtype (Avpr1b) Receptor Knockout Mice and Wild-Type Mice Treated with a Novel Avpr1b Receptor Antagonist

PubMed Central

Roper, J A; Craighead, M; O’Carroll, A-M; Lolait, S J

2010-01-01

Arginine vasopressin (AVP) synthesised in the parvocellular region of the hypothalamic paraventricular nucleus and released into the pituitary portal vessels acts on the 1b receptor subtype (Avpr1b) present in anterior pituitary corticotrophs to modulate the release of adrenocorticotrophic hormone (ACTH). Corticotrophin-releasing hormone is considered the major drive behind ACTH release; however, its action is augmented synergistically by AVP. To determine the extent of vasopressinergic influence in the hypothalamic-pituitary-adrenal axis response to restraint and forced swimming stress, we compared the stress hormone levels [plasma ACTH in both stressors and corticosterone (CORT) in restraint stress only] following acute stress in mutant Avpr1b knockout (KO) mice compared to their wild-type controls following the administration of a novel Avpr1b antagonist. Restraint and forced swimming stress-induced increases in plasma ACTH were significantly diminished in mice lacking a functional Avpr1b and in wild-type mice that had been pre-treated with Avpr1b antagonist. A corresponding decrease in plasma CORT levels was also observed in acute restraint-stressed knockout male mice, and in Avpr1b-antagonist-treated male wild-type mice. By contrast, plasma CORT levels were not reduced in acutely restraint-stressed female knockout animals, or in female wild-type animals pre-treated with Avpr1b antagonist. These results demonstrate that pharmacological antagonism or inactivation of Avpr1b causes a reduction in the hypothalamic-pituitary-adrenal (HPA) axis response, particularly ACTH, to acute restraint and forced swimming stress, and show that Avpr1b knockout mice constitute a model by which to study the contribution of Avpr1b to the HPA axis response to acute stressors. PMID:20846299

Attenuated stress response to acute restraint and forced swimming stress in arginine vasopressin 1b receptor subtype (Avpr1b) receptor knockout mice and wild-type mice treated with a novel Avpr1b receptor antagonist.

PubMed

Roper, J A; Craighead, M; O'Carroll, A-M; Lolait, S J

2010-11-01

Arginine vasopressin (AVP) synthesised in the parvocellular region of the hypothalamic paraventricular nucleus and released into the pituitary portal vessels acts on the 1b receptor subtype (Avpr1b) present in anterior pituitary corticotrophs to modulate the release of adrenocorticotrophic hormone (ACTH). Corticotrophin-releasing hormone is considered the major drive behind ACTH release; however, its action is augmented synergistically by AVP. To determine the extent of vasopressinergic influence in the hypothalamic-pituitary-adrenal axis response to restraint and forced swimming stress, we compared the stress hormone levels [plasma ACTH in both stressors and corticosterone (CORT) in restraint stress only] following acute stress in mutant Avpr1b knockout (KO) mice compared to their wild-type controls following the administration of a novel Avpr1b antagonist. Restraint and forced swimming stress-induced increases in plasma ACTH were significantly diminished in mice lacking a functional Avpr1b and in wild-type mice that had been pre-treated with Avpr1b antagonist. A corresponding decrease in plasma CORT levels was also observed in acute restraint-stressed knockout male mice, and in Avpr1b-antagonist-treated male wild-type mice. By contrast, plasma CORT levels were not reduced in acutely restraint-stressed female knockout animals, or in female wild-type animals pre-treated with Avpr1b antagonist. These results demonstrate that pharmacological antagonism or inactivation of Avpr1b causes a reduction in the hypothalamic-pituitary-adrenal (HPA) axis response, particularly ACTH, to acute restraint and forced swimming stress, and show that Avpr1b knockout mice constitute a model by which to study the contribution of Avpr1b to the HPA axis response to acute stressors. © 2010 The Authors. Journal of Neuroendocrinology © 2010 Blackwell Publishing Ltd.

Characteristics of colonic migrating motor complexes in neuronal NOS (nNOS) knockout mice.

PubMed

Spencer, Nick J

2013-01-01

It is well established that the intrinsic pacemaker mechanism that generates cyclical colonic migrating motor complexes (CMMCs) does not require endogenous nitric oxide (NO). However, pharmacological blockade of endogenous NO production potently increases the frequency of CMMCs, suggesting that endogenous NO acts normally to inhibit the CMMC pacemaker mechanism. In this study, we investigated whether mice with a life long genetic deletion of the neuronal nitric oxide synthase (nNOS) gene would show similar CMMC characteristics as wild type mice that have endogenous NO production acutely inhibited. Intracellular electrophysiological and mechanical recordings were made from circular muscle cells of isolated whole mouse colon in wild type and nNOS knockout (KO) mice at 35°C. In wild type mice, the NOS inhibitor, L-NA (100 μM) caused a significant increase in CMMC frequency and a significant depolarization of the CM layer. However, unexpectedly, the frequency of CMMCs in nNOS KO mice was not significantly different from control mice. Also, the resting membrane potential of CM cells in nNOS KO mice was not depolarized compared to controls; and the amplitude of the slow depolarization phase underlying MCs was of similar amplitude between KO and wild type offspring. These findings show that in nNOS KO mice, the major characteristics of CMMCs and their electrical correlates are, at least in adult mice, indistinguishable from wild type control offspring. One possibility why the major characteristics of CMMCs were no different between both types of mice is that nNOS KO mice may compensate for their life long deletion of the nNOS gene, and their permanent loss of neuronal NO production. In this regard, we suggest caution should be exercised when assuming that data obtained from adult nNOS KO mice can be directly extrapolated to wild type mice, that have been acutely exposed to an inhibitor of NOS.

Modulatory Role of Postsynaptic 5-Hydroxytryptamine Type 1A Receptors in (±)-8-Hydroxy-N,N-dipropyl-2-aminotetralin-Induced Hyperphagia in Mice.

PubMed

Brosda, Jan; Müller, Nadine; Bert, Bettina; Fink, Heidrun

2015-07-15

Brain serotonin (5-HT) is involved in the control of food intake. The ingestive effects of 5-HT are mediated by various receptor subtypes, among others the 5-HT1A receptor. While the involvement of presynaptic 5-HT1A receptors is regarded as certain, the role of postsynaptic 5-HT1A receptors is rather vague. Here, we studied the role of the 5-HT1A receptor on feeding in non-food-deprived and food-deprived (young adult and adult, both sexes) wild-type NMRI mice as well as transgenic NMRI mice, which are characterized by a distinct overexpression of postsynaptic 5-HT1A receptors. The known hyperphagic effect of the 5-HT1A receptor full agonist 8-OH-DPAT ((±)-8-hydroxy-N,N-dipropyl-2-aminotetralin) in non-food-deprived animals was demonstrated in male NMRI wild-type mice and could be antagonized by the selective 5-HT1A receptor antagonist WAY100635. In transgenic mice, this hyperphagic response was induced at lower doses, with an earlier onset and even in females. However, in adult male transgenic mice, the hyperphagic effect did not occur. In food-deprived NMRI wild-type as well as transgenic mice, 8-OH-DPAT first induced a hypophagic and subsequently a hyperphagic effect. Again, in transgenic animals most responses occurred at lower doses and with an earlier onset. The results indicate that postsynaptic 5-HT1A receptors exert a modulatory function in food intake in free-feeding and fasted mice, which for the first time shows an involvement of postsynaptic 5-HT1A receptors in feeding behavior. Understanding the function of pre- and postsynaptic 5-HT1A receptors may help to achieve new insights into the regulation of food intake and foster prospective treatment strategies for eating disorders.

Systemic metabolite changes in wild-type C57BL/6 mice fed black raspberries

PubMed Central

Pan, Pan; Skaer, Chad W.; Wang, Hsin-Tzu; Kreiser, Michael A.; Stirdivant, Steven M.; Oshima, Kiyoko; Huang, Yi-Wen; Young, Matthew R.; Wang, Li-Shu

2017-01-01

Introduction Freeze-dried black raspberries (BRBs) elicit chemopreventive effects against colorectal cancer in humans and in rodents. The study objective was to investigate potential BRB-caused metabolite changes using wild-type (WT) C57BL/6 mice. Methods and results WT mice were fed either control diet or control diet supplemented with 5% BRBs for 8 weeks. A non-targeted metabolomic analysis was conducted on colonic mucosa, liver, and fecal specimens collected from both diet groups. BRBs significantly changed the levels of 41 colonic mucosa metabolites, 40 liver metabolites and 34 fecal metabolites compared to control diet-fed mice. BRBs reduced 34 lipid metabolites in colonic mucosa and increased levels of amino acids in liver. One metabolite, 3-[3-(sulfooxy) phenyl] propanoic acid, might be a useful biomarker of BRB consumption. In addition, BRB powder was found to contain 30-fold higher levels of linolenate compared to control diets. Consistently, multiple omega-3 polyunsaturated fatty acids (ω-3 PUFAs), including stearidonate, docosapentaenoate (ω-3 DPA), eicosapentaenoate (EPA) and docosahexaenoate (DHA), were significantly elevated in livers of BRB-fed mice. Conclusion The data from the current study suggest that BRBs produce systemic metabolite changes in multiple tissue matrices, supporting our hypothesis that BRBs may serve as both a chemopreventive agent and a beneficial dietary supplement. PMID:28094560

Postnatal colonization with human "infant-type" Bifidobacterium species alters behavior of adult gnotobiotic mice.

PubMed

Luk, Berkley; Veeraragavan, Surabi; Engevik, Melinda; Balderas, Miriam; Major, Angela; Runge, Jessica; Luna, Ruth Ann; Versalovic, James

2018-01-01

Accumulating studies have defined a role for the intestinal microbiota in modulation of host behavior. Research using gnotobiotic mice emphasizes that early microbial colonization with a complex microbiota (conventionalization) can rescue some of the behavioral abnormalities observed in mice that grow to adulthood completely devoid of bacteria (germ-free mice). However, the human infant and adult microbiomes vary greatly, and effects of the neonatal microbiome on neurodevelopment are currently not well understood. Microbe-mediated modulation of neural circuit patterning in the brain during neurodevelopment may have significant long-term implications that we are only beginning to appreciate. Modulation of the host central nervous system by the early-life microbiota is predicted to have pervasive and lasting effects on brain function and behavior. We sought to replicate this early microbe-host interaction by colonizing gnotobiotic mice at the neonatal stage with a simplified model of the human infant gut microbiota. This model consortium consisted of four "infant-type" Bifidobacterium species known to be commensal members of the human infant microbiota present in high abundance during postnatal development. Germ-free mice and mice neonatally-colonized with a complex, conventional murine microbiota were used for comparison. Motor and non-motor behaviors of the mice were tested at 6-7 weeks of age, and colonization patterns were characterized by 16S ribosomal RNA gene sequencing. Adult germ-free mice were observed to have abnormal memory, sociability, anxiety-like behaviors, and motor performance. Conventionalization at the neonatal stage rescued these behavioral abnormalities, and mice colonized with Bifidobacterium spp. also exhibited important behavioral differences relative to the germ-free controls. The ability of Bifidobacterium spp. to improve the recognition memory of both male and female germ-free mice was a prominent finding. Together, these data demonstrate

Contribution of B2 receptors for bradykinin in Arthus reaction-induced plasma extravasation in wild-type or B2 transgenic knockout mice

PubMed Central

Samadfam, R; Teixeira, C; Bkaily, G; Sirois, P; de Brum-Fernandes, A; D'Orleans-Juste, P

2000-01-01

The aim of the present study was to investigate the contribution of bradykinin (BK) B1 and B2 receptors in a model of type III hypersensitivity, the reverse passive Arthus reaction (RPA), in wild-type mice and transgenic B2 knockout littermates.BK (10 μg mouse−1) or bovine serum albumin (0.5 mg mouse−1) induced a sustained Evans blue extravasation for more than 80 min in naive or rabbit anti-bovine serum albumin-treated mice (RPA model), respectively. The response to the two stimuli was prevented by the B2 receptor antagonist, HOE-140, but not by [Leu8]desArg9-BK (B1 receptor antagonist).In contrast to the wild-type littermates, RPA and bradykinin were unable to trigger an increase in plasma extravasation in B2 knockout mice.Furthermore, endothelin-1 (5 μg mouse−1) and a selective NK-1 receptor agonist [Sar9,Met (O2)11]-SP (20 μg mouse−1), triggered a significant increase in peritoneal plasma extravasation in both wild-type and B2 knockout animals.A pretreatment with indomethacin (200 μg mouse−1) significantly reduced the RPA-induced but not the BK-induced increase in Evans blue extravasation. Furthermore, RPA, but not BK, triggered a significant indomethacin-sensitive increase in peritoneal prostaglandin E2 content.Our results suggest a pivotal role for B2 receptors in the mechanism of plasma extravasation which occurs during the reverse passive Arthus reaction in the mouse. Moreover, our results suggest an important contribution of prostanoids in the plasma leakage mechanisms triggered by RPA but not by bradykinin. PMID:10780980

Activation of microglia induces symptoms of Parkinson’s disease in wild-type, but not in IL-1 knockout mice

PubMed Central

2013-01-01

Background Parkinson’s disease (PD) is an age-related progressive neurodegenerative disorder caused by selective loss of dopaminergic neurons from the substantia nigra (SN) to the striatum. The initial factor that triggers neurodegeneration is unknown; however, inflammation has been demonstrated to be significantly involved in the progression of PD. The present study was designed to investigate the role of the pro-inflammatory cytokine interleukin-1 (IL-1) in the activation of microglia and the decline of motor function using IL-1 knockout (KO) mice. Methods Lipopolysaccharide (LPS) was stereotaxically injected into the SN of mice brains as a single dose or a daily dose for 5 days (5 mg/2 ml/injection, bilaterally). Animal behavior was assessed with the rotarod test at 2 hr and 8, 15 and 22 days after the final LPS injection. Results LPS treatment induced the activation of microglia, as demonstrated by production of IL-1β and tumor necrosis factor (TNF) α as well as a change in microglial morphology. The number of cells immunoreactive for 4-hydroxynonenal (4HNE) and nitrotyrosine (NT), which are markers for oxidative insults, increased in the SN, and impairment of motor function was observed after the subacute LPS treatment. Cell death and aggregation of α-synuclein were observed 21 and 30 days after the final LPS injection, respectively. Behavioral deficits were observed in wild-type and TNFα KO mice, but IL-1 KO mice behaved normally. Tyrosine hydroxylase (TH) gene expression was attenuated by LPS treatment in wild-type and TNFα KO mice but not in IL-1 KO mice. Conclusions The subacute injection of LPS into the SN induces PD-like pathogenesis and symptoms in mice that mimic the progressive changes of PD including the aggregation of α-synuclein. LPS-induced dysfunction of motor performance was accompanied by the reduced gene expression of TH. These findings suggest that activation of microglia by LPS causes functional changes such as dopaminergic neuron

Kuru prions and sporadic Creutzfeldt–Jakob disease prions have equivalent transmission properties in transgenic and wild-type mice

PubMed Central

Wadsworth, Jonathan D. F.; Joiner, Susan; Linehan, Jacqueline M.; Desbruslais, Melanie; Fox, Katie; Cooper, Sharon; Cronier, Sabrina; Asante, Emmanuel A.; Mead, Simon; Brandner, Sebastian; Hill, Andrew F.; Collinge, John

2008-01-01

Kuru provides our principal experience of an epidemic human prion disease and primarily affected the Fore linguistic group of the Eastern Highlands of Papua New Guinea. Kuru was transmitted by the practice of consuming dead relatives as a mark of respect and mourning (transumption). To date, detailed information of the prion strain type propagated in kuru has been lacking. Here, we directly compare the transmission properties of kuru prions with sporadic, iatrogenic, and variant Creutzfeldt–Jakob disease (CJD) prions in Prnp-null transgenic mice expressing human prion protein and in wild-type mice. Molecular and neuropathological data from these transmissions show that kuru prions are distinct from variant CJD and have transmission properties equivalent to those of classical (sporadic) CJD prions. These findings are consistent with the hypothesis that kuru originated from chance consumption of an individual with sporadic CJD. PMID:18316717

The comparative immunology of wild and laboratory mice, Mus musculus domesticus

PubMed Central

Abolins, Stephen; King, Elizabeth C.; Lazarou, Luke; Weldon, Laura; Hughes, Louise; Drescher, Paul; Raynes, John G.; Hafalla, Julius C. R.; Viney, Mark E.; Riley, Eleanor M.

2017-01-01

The laboratory mouse is the workhorse of immunology, used as a model of mammalian immune function, but how well immune responses of laboratory mice reflect those of free-living animals is unknown. Here we comprehensively characterize serological, cellular and functional immune parameters of wild mice and compare them with laboratory mice, finding that wild mouse cellular immune systems are, comparatively, in a highly activated (primed) state. Associations between immune parameters and infection suggest that high level pathogen exposure drives this activation. Moreover, wild mice have a population of highly activated myeloid cells not present in laboratory mice. By contrast, in vitro cytokine responses to pathogen-associated ligands are generally lower in cells from wild mice, probably reflecting the importance of maintaining immune homeostasis in the face of intense antigenic challenge in the wild. These data provide a comprehensive basis for validating (or not) laboratory mice as a useful and relevant immunological model system. PMID:28466840

Spaceflight Influences both Mucosal and Peripheral Cytokine Production in PTN-Tg and Wild Type Mice

PubMed Central

Liu, Yi; Kalmokoff, Martin; Brooks, Stephen P. J.; Green-Johnson, Julia M.

2013-01-01

Spaceflight is associated with several health issues including diminished immune efficiency. Effects of long-term spaceflight on selected immune parameters of wild type (Wt) and transgenic mice over-expressing pleiotrophin under the human bone-specific osteocalcin promoter (PTN-Tg) were examined using the novel Mouse Drawer System (MDS) aboard the International Space Station (ISS) over a 91 day period. Effects of this long duration flight on PTN-Tg and Wt mice were determined in comparison to ground controls and vivarium-housed PTN-Tg and Wt mice. Levels of interleukin-2 (IL-2) and transforming growth factor-beta1 (TGF-β1) were measured in mucosal and systemic tissues of Wt and PTN-Tg mice. Colonic contents were also analyzed to assess potential effects on the gut microbiota, although no firm conclusions could be made due to constraints imposed by the MDS payload and the time of sampling. Spaceflight-associated differences were observed in colonic tissue and systemic lymph node levels of IL-2 and TGF-β1 relative to ground controls. Total colonic TGF-β1 levels were lower in Wt and PTN-Tg flight mice in comparison to ground controls. The Wt flight mouse had lower levels of IL-2 and TGF-β1 compared to the Wt ground control in both the inguinal and brachial lymph nodes, however this pattern was not consistently observed in PTN-Tg mice. Vivarium-housed Wt controls had higher levels of active TGF-β1 and IL-2 in inguinal lymph nodes relative to PTN-Tg mice. The results of this study suggest compartmentalized effects of spaceflight and on immune parameters in mice. PMID:23874826

Atm heterozygous mice are more sensitive to radiation-induced cataracts than are their wild-type counterparts

NASA Technical Reports Server (NTRS)

Worgul, Basil V.; Smilenov, Lubomir; Brenner, David J.; Junk, Anna; Zhou, Wei; Hall, Eric J.

2002-01-01

It is important to know whether the human population includes genetically predisposed radiosensitive subsets. In vitro studies have shown that cells from individuals homozygous for ataxia telangiectasia (A-T) are much more radiosensitive than cells from unaffected individuals. Although cells heterozygous for the ATM gene (ATM(+/-)) may be slightly more radiosensitive in vitro, it remained to be determined whether the greater susceptibility of ATM(+/-) cells translates into an increased sensitivity for late effects in vivo, though there is a suggestion that radiotherapy patients that are heterozygous for the ATM gene may be more at risk of developing late normal tissue damage. We chose cataractogenesis in the lens as a means to assay for the effects of ATM deficiency in a late-responding tissue. One eye of wild-type, Atm heterozygous and homozygous knockout mice was exposed to 0.5-, 1.0-, 2.0-, or 4.0-Gy x rays. The animals were followed weekly for cataract development by conventional slit-lamp biomicroscopy. Cataract development in the animals of all three groups was strongly dependent on dose. The lenses of homozygous mice were the first to opacify at any given dose. Most important in the present context is that cataracts appeared earlier in the heterozygous versus wild-type animals. The data suggest that ATM heterozygotes in the human population may also be radiosensitive. This may influence the choice of individuals destined to be exposed to higher than normal doses of radiation, such as astronauts, and may also suggest that radiotherapy patients who are ATM heterozygotes could be predisposed to increased late normal tissue damage.

Retinal ganglion cell responses to voltage and current stimulation in wild-type and rd1 mouse retinas

NASA Astrophysics Data System (ADS)

Goo, Yong Sook; Ye, Jang Hee; Lee, Seokyoung; Nam, Yoonkey; Ryu, Sang Baek; Kim, Kyung Hwan

2011-06-01

Retinal prostheses are being developed to restore vision for those with retinal diseases such as retinitis pigmentosa or age-related macular degeneration. Since neural prostheses depend upon electrical stimulation to control neural activity, optimal stimulation parameters for successful encoding of visual information are one of the most important requirements to enable visual perception. In this paper, we focused on retinal ganglion cell (RGC) responses to different stimulation parameters and compared threshold charge densities in wild-type and rd1 mice. For this purpose, we used in vitro retinal preparations of wild-type and rd1 mice. When the neural network was stimulated with voltage- and current-controlled pulses, RGCs from both wild-type and rd1 mice responded; however the temporal pattern of RGC response is very different. In wild-type RGCs, a single peak within 100 ms appears, while multiple peaks (approximately four peaks) with ~10 Hz rhythm within 400 ms appear in RGCs in the degenerated retina of rd1 mice. We find that an anodic phase-first biphasic voltage-controlled pulse is more efficient for stimulation than a biphasic current-controlled pulse based on lower threshold charge density. The threshold charge densities for activation of RGCs both with voltage- and current-controlled pulses are overall more elevated for the rd1 mouse than the wild-type mouse. Here, we propose the stimulus range for wild-type and rd1 retinas when the optimal modulation of a RGC response is possible.

Vitamin D2-Enriched Button Mushroom (Agaricus bisporus) Improves Memory in Both Wild Type and APPswe/PS1dE9 Transgenic Mice

PubMed Central

Bennett, Louise; Kersaitis, Cindy; Macaulay, Stuart Lance; Münch, Gerald; Niedermayer, Garry; Nigro, Julie; Payne, Matthew; Sheean, Paul; Vallotton, Pascal; Zabaras, Dimitrios; Bird, Michael

2013-01-01

Vitamin D deficiency is widespread, affecting over 30% of adult Australians, and increasing up to 80% for at-risk groups including the elderly (age>65). The role for Vitamin D in development of the central nervous system is supported by the association between Vitamin D deficiency and incidence of neurological and psychiatric disorders including Alzheimer’s disease (AD). A reported positive relationship between Vitamin D status and cognitive performance suggests that restoring Vitamin D status might provide a cognitive benefit to those with Vitamin D deficiency. Mushrooms are a rich source of ergosterol, which can be converted to Vitamin D2 by treatment with UV light, presenting a new and convenient dietary source of Vitamin D2. We hypothesised that Vitamin D2-enriched mushrooms (VDM) could prevent the cognitive and pathological abnormalities associated with dementia. Two month old wild type (B6C3) and AD transgenic (APPSwe/PS1dE9) mice were fed a diet either deficient in Vitamin D2 or a diet which was supplemented with VDM, containing 1±0.2 µg/kg (∼54 IU/kg) vitamin D2, for 7 months. Effects of the dietary intervention on memory were assessed pre- and post-feeding. Brain sections were evaluated for amyloid β (Aβ) plaque loads and inflammation biomarkers using immuno-histochemical methods. Plasma vitamin D metabolites, Aβ40, Aβ42, calcium, protein and cholesterol were measured using biochemical assays. Compared with mice on the control diet, VDM-fed wild type and AD transgenic mice displayed improved learning and memory, had significantly reduced amyloid plaque load and glial fibrillary acidic protein, and elevated interleukin-10 in the brain. The results suggest that VDM might provide a dietary source of Vitamin D2 and other bioactives for preventing memory-impairment in dementia. This study supports the need for a randomised clinical trial to determine whether or not VDM consumption can benefit cognitive performance in the wider population. PMID

Lipidomic and metabolic changes in the P4-type ATPase ATP10D deficient C57BL/6J wild type mice upon rescue of ATP10D function.

PubMed

Sigruener, Alexander; Wolfrum, Christian; Boettcher, Alfred; Kopf, Thomas; Liebisch, Gerhard; Orsó, Evelyn; Schmitz, Gerd

2017-01-01

Sequence variants near the human gene for P4-type ATPase, class V, type 10D (ATP10D) were shown to significantly associate with circulating hexosylceramide d18:1/16:0 and d18:1/24:1 levels, obesity, insulin resistance, plasma high density lipoprotein (HDL), coronary stenotic index and intracranial atherosclerotic index. In mice Atp10d is associated with HDL modulation and C57BL/6 mice expressing a truncated, non-functional form of ATP10D easily develop obesity and insulin resistance on high-fat diet. We analyzed metabolic differences of ATP10D deficient C57BL/6J wild type and ATP10D transgenic C57BL/6J BAC129 mice. ATP10D transgenic mice gain 25% less weight on high-fat diet concomitant with a reduced increase in fat cell mass but independent of adipocyte size change. ATP10D transgenic mice also had 26% lower triacylglycerol levels with approximately 76% bound to very low density lipoprotein while in ATP10D deficient wild type mice 57% are bound to low density lipoprotein. Furthermore increased oxygen consumption and CO2 production, 38% lower glucose and 69% lower insulin levels and better insulin sensitivity were observed in ATP10D transgenic mice. Besides decreased hexosylceramide species levels were detected. Part of these effects may be due to reduced hepatic stearoyl-CoA desaturase 1 (SCD1) expression in ATP10D transgenic mice, which was reflected by altered fatty acid and lipid species patterns. There was a significant decrease in the hepatic 18:1 to 18:0 free fatty acid ratio in transgenic mice. The ratio of 16:1 to 16:0 was not significantly different. Interestingly both ratios were significantly reduced in plasma total fatty acids. In summary we found that ATP10D reduces high-fat diet induced obesity and improves insulin sensitivity. ATP10D transgenic mice showed altered hepatic expression of lipid-metabolism associated genes, including Scd1, along with changes in hepatic and plasma lipid species and plasma lipoprotein pattern.

Ultrasonic vocalizations of adult male Foxp2-mutant mice: behavioral contexts of arousal and emotion.

PubMed

Gaub, S; Fisher, S E; Ehret, G

2016-02-01

Adult mouse ultrasonic vocalizations (USVs) occur in multiple behavioral and stimulus contexts associated with various levels of arousal, emotion and social interaction. Here, in three experiments of increasing stimulus intensity (water; female urine; male interacting with adult female), we tested the hypothesis that USVs of adult males express the strength of arousal and emotion via different USV parameters (18 parameters analyzed). Furthermore, we analyzed two mouse lines with heterozygous Foxp2 mutations (R552H missense, S321X nonsense), known to produce severe speech and language disorders in humans. These experiments allowed us to test whether intact Foxp2 function is necessary for developing full adult USV repertoires, and whether mutations of this gene influence instinctive vocal expressions based on arousal and emotion. The results suggest that USV calling rate characterizes the arousal level, while sound pressure and spectrotemporal call complexity (overtones/harmonics, type of frequency jumps) may provide indices of levels of positive emotion. The presence of Foxp2 mutations did not qualitatively affect the USVs; all USV types that were found in wild-type animals also occurred in heterozygous mutants. However, mice with Foxp2 mutations displayed quantitative differences in USVs as compared to wild-types, and these changes were context dependent. Compared to wild-type animals, heterozygous mutants emitted mainly longer and louder USVs at higher minimum frequencies with a higher occurrence rate of overtones/harmonics and complex frequency jump types. We discuss possible hypotheses about Foxp2 influence on emotional vocal expressions, which can be investigated in future experiments using selective knockdown of Foxp2 in specific brain circuits. © 2015 John Wiley & Sons Ltd and International Behavioural and Neural Genetics Society.

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.

Wild-type myoblasts rescue the ability of myogenin-null myoblasts to fuse in vivo.

PubMed

Myer, A; Wagner, D S; Vivian, J L; Olson, E N; Klein, W H

1997-05-15

Skeletal muscle is formed via a complex series of events during embryogenesis. These events include commitment of mesodermal precursor cells, cell migration, cell-cell recognition, fusion of myoblasts, activation of structural genes, and maturation. In mice lacking the bHLH transcription factor myogenin, myoblasts are specified and positioned correctly, but few fuse to form multinucleated fibers. This indicates that myogenin is critical for the fusion process and subsequent differentiation events of myogenesis. To further define the nature of the myogenic defects in myogenin-null mice, we investigated whether myogenin-null myoblasts are capable of fusing with wild-type myoblasts in vivo using chimeric mice containing mixtures of myogenin-null and wild-type cells. Chimeric embryos demonstrated that myogenin-null myoblasts readily fused in the presence of wild-type myoblasts. However, chimeric myofibers did not express wild-type levels of muscle-specific gene products, and myofibers with a high percentage of mutant nuclei appeared abnormal, suggesting that the wild-type nuclei could not fully rescue mutant nuclei in the myofibers. These data demonstrate that myoblast fusion can be uncoupled from complete myogenic differentiation and that myogenin regulates a specific subset of genes with diverse function. Thus, myogenin appears to control not only transcription of muscle structural genes but also the extracellular environment in which myoblast fusion takes place. We propose that myogenin regulates the expression of one or more extracellular or cell surface proteins required to initiate the muscle differentiation program.

The effect of calorie restriction on the presence of apoptotic ovarian cells in normal wild type mice and low-plasma-IGF-1 Laron dwarf mice

PubMed Central

2013-01-01

Background It is known that caloric restriction extends lifespan and can minimize age-related dysfunction of the reproductive system. We became interested in how caloric restriction influences apoptosis, which is a crucial process that maintains ovarian cell homeostasis. Methods We examined ovarian cells in: 2.5-year-old wild type mice on caloric restriction (CR) or fed ad libitum (AL) and Laron dwarf mice (GHR-KO) at the same ages on CR or fed AL. Apoptosis was assessed by histochemical analysis on paraffin sections of ovarian tissue. Results Morphological and histochemical analysis revealed that CR improved reproductive potential in 2.5-year-old WT littermates and GHR-KO female mice, as indicated by the increased number of ovarian follicles. The level of apoptosis in ovarian tissue was higher in WT mice on a CR diet compared with WT mice on the AL diet. In GHR-KO mice, the level of apoptosis in ovaries was similar for mice on CR and on AL diets and bigger than in WT mice on CR. Conclusions Morphological and histochemical analysis revealed a younger biological age of the ovaries in 2-year-old WT littermates and GHR-KO female mice on CR compared with animals fed AL. PMID:24063422

Fertility comparison between wild type and transgenic mice by in vitro fertilization.

PubMed

Vasudevan, Kuzhalini; Raber, James; Sztein, Jorge

2010-08-01

from superovulated females were inseminated with sperm of same background. Fertility rate was considered as the percentage of two cell embryos scored 24 h after insemination. The data collected from this study shows that the fertilization rate is affected (reduced to half fold) in some of the transgenic mice compared to the respective Wild Type (WT) mice. For the WT the average fertility rate ranged from 80% (C57BL/6), 90% (FVB/N), 45% (129Sv/J x C57Bl/6)F1 and 43% (CD1). For transgenic mice it was 52% (C57BL/6), 65% (FVB/N), 22% (129Sv/J x C57Bl/6)F1 and 25% (CD1).

Atm heterozygous mice are more sensitive to radiation-induced cataracts than are their wild-type counterparts

PubMed Central

Worgul, Basil V.; Smilenov, Lubomir; Brenner, David J.; Junk, Anna; Zhou, Wei; Hall, Eric J.

2002-01-01

It is important to know whether the human population includes genetically predisposed radiosensitive subsets. In vitro studies have shown that cells from individuals homozygous for ataxia telangiectasia (A-T) are much more radiosensitive than cells from unaffected individuals. Although cells heterozygous for the ATM gene (ATM+/−) may be slightly more radiosensitive in vitro, it remained to be determined whether the greater susceptibility of ATM+/− cells translates into an increased sensitivity for late effects in vivo, though there is a suggestion that radiotherapy patients that are heterozygous for the ATM gene may be more at risk of developing late normal tissue damage. We chose cataractogenesis in the lens as a means to assay for the effects of ATM deficiency in a late-responding tissue. One eye of wild-type, Atm heterozygous and homozygous knockout mice was exposed to 0.5-, 1.0-, 2.0-, or 4.0-Gy x rays. The animals were followed weekly for cataract development by conventional slit-lamp biomicroscopy. Cataract development in the animals of all three groups was strongly dependent on dose. The lenses of homozygous mice were the first to opacify at any given dose. Most important in the present context is that cataracts appeared earlier in the heterozygous versus wild-type animals. The data suggest that ATM heterozygotes in the human population may also be radiosensitive. This may influence the choice of individuals destined to be exposed to higher than normal doses of radiation, such as astronauts, and may also suggest that radiotherapy patients who are ATM heterozygotes could be predisposed to increased late normal tissue damage. PMID:12119422

Nuclear factor erythroid 2-related factor 2 deletion impairs glucose tolerance and exacerbates hyperglycemia in type 1 diabetic mice.

PubMed

Aleksunes, Lauren M; Reisman, Scott A; Yeager, Ronnie L; Goedken, Michael J; Klaassen, Curtis D

2010-04-01

The transcription factor nuclear factor erythroid 2-related factor 2 (Nrf2) induces a battery of cytoprotective genes after oxidative stress. Nrf2 aids in liver regeneration by altering insulin signaling; however, whether Nrf2 participates in hepatic glucose homeostasis is unknown. Compared with wild-type mice, mice lacking Nrf2 (Nrf2-null) have lower basal serum insulin and prolonged hyperglycemia in response to an intraperitoneal glucose challenge. In the present study, blood glucose, serum insulin, urine flow rate, and hepatic expression of glucose-related genes were quantified in male diabetic wild-type and Nrf2-null mice. Type 1 diabetes was induced with a single intraperitoneal dose (200 mg/kg) of streptozotocin (STZ). Histopathology and serum insulin levels confirmed depleted pancreatic beta-cells in STZ-treated mice of both genotypes. Five days after STZ, Nrf2-null mice had higher blood glucose levels than wild-type mice. Nine days after STZ, polyuria occurred in both genotypes with more urine output from Nrf2-null mice (11-fold) than wild-type mice (7-fold). Moreover, STZ-treated Nrf2-null mice had higher levels of serum beta-hydroxybutyrate, triglycerides, and fatty acids 10 days after STZ compared with wild-type mice. STZ reduced hepatic glycogen in both genotypes, with less observed in Nrf2-null mice. Increased urine output and blood glucose in STZ-treated Nrf2-null mice corresponded with enhanced gluconeogenesis (glucose-6-phosphatase and phosphoenolpyruvate carboxykinase)- and reduced glycolysis (pyruvate kinase)-related mRNA expression in their livers. Furthermore, the Nrf2 activator oltipraz lowered blood glucose in wild-type but not Nrf2-null mice administered STZ. Collectively, these data indicate that the absence of Nrf2 worsens hyperglycemia in type I diabetic mice and Nrf2 may represent a therapeutic target for reducing circulating glucose levels.

Ethanol and 4-methylpyrazole increase DNA adduct formation of furfuryl alcohol in FVB/N wild-type mice and in mice expressing human sulfotransferases 1A1/1A2.

PubMed

Sachse, Benjamin; Meinl, Walter; Glatt, Hansruedi; Monien, Bernhard H

2016-03-01

Furfuryl alcohol (FFA) is a carcinogenic food contaminant, which is formed by acid- and heat-catalyzed degradation of fructose and glucose. The activation by sulfotransferases (SULTs) yields a DNA reactive and mutagenic sulfate ester. The most prominent DNA adduct, N(2)-((furan-2-yl)methyl)-2'-deoxyguanosine (N(2)-MF-dG), was detected in FFA-treated mice and also in human tissue samples. The dominant pathway of FFA detoxification is the oxidation via alcohol dehydrogenases (ADHs) and aldehyde dehydrogenases (ALDHs). The activity of these enzymes may be greatly altered in the presence of inhibitors or competitive substrates. Here, we investigated the impact of ethanol and the ADH inhibitor 4-methylpyrazole (4MP) on the DNA adduct formation by FFA in wild-type and in humanized mice that were transgenic for human SULT1A1/1A2 and deficient in the mouse (m) Sult1a1 and Sult1d1 genes (h1A1/1A2/1a1(-)/1d1(-)). The administration of FFA alone led to hepatic adduct levels of 4.5 N(2)-MF-dG/10(8) nucleosides and 33.6 N(2)-MF-dG/10(8) nucleosides in male and female wild-type mice, respectively, and of 19.6 N(2)-MF-dG/10(8) nucleosides and 95.4 N(2)-MF-dG/10(8) nucleosides in male and female h1A1/1A2/1a1(-)/1d1(-) mice. The coadministration of 1.6g ethanol/kg body weight increased N(2)-MF-dG levels by 2.3-fold in male and by 1.7-fold in female wild-type mice and by 2.5-fold in male and by 1.5-fold in female h1A1/1A2/1a1(-)/1d1(-) mice. The coadministration of 100mg 4MP/kg body weight had a similar effect on the adduct levels. These findings indicate that modulators of the oxidative metabolism, e.g. the drug 4MP or consumption of alcoholic beverages, may increase the genotoxic effects of FFA also in humans. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Characteristics of Sleep and Wakefulness inWild-Derived Inbred Mice

PubMed Central

HIYOSHI, Hideyuki; TERAO, Akira; OKAMATSU-OGURA, Yuko; KIMURA, Kazuhiro

2014-01-01

Genetic variations in the wild-derived inbred mouse strains are more diverse than that of classical laboratory inbred mouse strains, including C57BL/6J (B6). The sleep/wake and monoamine properties of six wild-derived inbred mouse strains (PGN2, NJL, BLG2, KJR, MSM, HMI) were characterized and compared with those of B6 mice. All examined mice were nocturnal and had a polyphasic sleep pattern with a “main sleep period” identified during the light period. However, there were three sleep/wake phenotypic differences between the wild-derived mouse strains and B6 strain. First, the amount of sleep during the dark phase was comparable with that of B6 mice. However, the amount of sleep during the light phase was more varied among strains, in particular, NJL and HMI had significantly less sleep compared with that of B6 mice. Second, PGN2, NJL, BLG2, and KJR mice showed a “highly awake period” (in which the hourly total sleep time was <10%) immediately after the onset of the dark period, which was not seen in B6 mice. Third, relative to that of B6 mice, PGN2 and KJR mice showed longer duration of wakefulness episodes during the 12-h dark phase. Differences in whole brain noradrenaline, dopamine, and 5-hydroxy-tryptamine contents between the wild-derived mouse strains and B6 strain were also found. These identified phenotypes might be potentially under strong genetic control. Hence, wild-derived inbred mice could be useful for identifying the genetic factors underlying the regulation of sleep and wakefulness. PMID:24770646

Pkd1 transgenic mice: adult model of polycystic kidney disease with extrarenal and renal phenotypes

PubMed Central

Kurbegovic, Almira; Côté, Olivier; Couillard, Martin; Ward, Christopher J.; Harris, Peter C.; Trudel, Marie

2010-01-01

While high levels of Pkd1 expression are detected in tissues of patients with autosomal dominant polycystic kidney disease (ADPKD), it is unclear whether enhanced expression could be a pathogenetic mechanism for this systemic disorder. Three transgenic mouse lines were generated from a Pkd1-BAC modified by introducing a silent tag via homologous recombination to target a sustained wild-type genomic Pkd1 expression within the native tissue and temporal regulation. These mice specifically overexpressed the Pkd1 transgene in extrarenal and renal tissues from ∼2- to 15-fold over Pkd1 endogenous levels in a copy-dependent manner. All transgenic mice reproducibly developed tubular and glomerular cysts leading to renal insufficiency. Interestingly, Pkd1TAG mice also exhibited renal fibrosis and calcium deposits in papilla reminiscent of nephrolithiasis as frequently observed in ADPKD. Similar to human ADPKD, these mice consistently displayed hepatic fibrosis and ∼15% intrahepatic cysts of the bile ducts affecting females preferentially. Moreover, a significant proportion of mice developed cardiac anomalies with severe left-ventricular hypertrophy, marked aortic arch distention and/or valvular stenosis and calcification that had profound functional impact. Of significance, Pkd1TAG mice displayed occasional cerebral lesions with evidence of ruptured and unruptured cerebral aneurysms. This Pkd1TAG mouse model demonstrates that overexpression of wild-type Pkd1 can trigger the typical adult renal and extrarenal phenotypes resembling human ADPKD. PMID:20053665

Elucidation of the atherosclerotic disease process in apo E and wild type mice by vibrational spectroscopy

NASA Astrophysics Data System (ADS)

Adar, Fran; Jelicks, Linda; Naudin, Coralie; Rousseau, Denis; Yeh, Syun-ru

2004-07-01

Raman and FTIR microprobe spectroscopy have been used to characterize the atherosclerotic process in Apo E and wild type mice. The Apo E null mouse is being studied in parallel with a healthy strain as a model of the human atherosclerotic disease. Preliminary Raman microprobe spectra have been recorded from the lumen of the aorta vessels from a normal black mouse (C57BL/6J) and the apo E null mouse fed on a normal chow diet. Spectra were also recorded from another normal mouse fed breeder chow containing a much higher content of fats. In the Raman spectra the fat cells exhibited spectra typical of esterified triglycerides while the wall tissue had spectra dominated by Amide I and III modes and the phenylalanine stretch at 1003 cm-1 of protein. The FTIR spectra showed the typical Amide I and II bands of protein and the strong >C=O stretch of the triglycerides. In addition, there were morphologically distinct regions of the specimens indicating a surprising form of calcification in one very old mouse (wild type), and free fatty acid inclusions in the knock out mouse. The observation of these chemistries provide new information for elucidation of the molecular mechanisms of the development of atherosclerosis.

PHEX Mimetic (SPR4-Peptide) Corrects and Improves HYP and Wild Type Mice Energy-Metabolism

PubMed Central

Zelenchuk, Lesya V.; Hedge, Anne-Marie; Rowe, Peter S. N.

2014-01-01

Context PHEX or DMP1 mutations cause hypophosphatemic-rickets and altered energy metabolism. PHEX binds to DMP1-ASARM-motif to form a complex with α5β3 integrin that suppresses FGF23 expression. ASARM-peptides increase FGF23 by disrupting the PHEX-DMP1-Integrin complex. We used a 4.2 kDa peptide (SPR4) that binds to ASARM-peptide/motif to study the DMP1-PHEX interaction and to assess SPR4 for the treatment of energy metabolism defects in HYP and potentially other bone-mineral disorders. Design Subcutaneously transplanted osmotic pumps were used to infuse SPR4-peptide or vehicle (VE) into wild-type mice (WT) and HYP-mice (PHEX mutation) for 4 weeks. Results SPR4 partially corrected HYP mice hypophosphatemia and increased serum 1.25(OH)2D3. Serum FGF23 remained high and PTH was unaffected. WT-SPR4 mice developed hypophosphatemia and hypercalcemia with increased PTH, FGF23 and 1.25(OH)2D3. SPR4 increased GAPDH HYP-bone expression 60× and corrected HYP-mice hyperglycemia and hypoinsulinemia. HYP-VE serum uric-acid (UA) levels were reduced and SPR4 infusion suppressed UA levels in WT-mice but not HYP-mice. SPR4 altered leptin, adiponectin, and sympathetic-tone and increased the fat mass/weight ratio for HYP and WT mice. Expression of perlipin-2 a gene involved in obesity was reduced in HYP-VE and WT-SPR4 mice but increased in HYP-SPR4 mice. Also, increased expression of two genes that inhibit insulin-signaling, ENPP1 and ESP, occurred with HYP-VE mice. In contrast, SPR4 reduced expression of both ENPP1 and ESP in WT mice and suppressed ENPP1 in HYP mice. Increased expression of FAM20C and sclerostin occurred with HYP-VE mice. SPR4 suppressed expression of FAM20C and sclerostin in HYP and WT mice. Conclusions ASARM peptides and motifs are physiological substrates for PHEX and modulate osteocyte PHEX-DMP1-α5β3-integrin interactions and thereby FGF23 expression. These interactions also provide a nexus that regulates bone and energy metabolism. SPR4 suppression of

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.

Intake of Wild Blueberry Powder Improves Episodic-Like and Working Memory during Normal Aging in Mice.

PubMed

Beracochea, Daniel; Krazem, Ali; Henkouss, Nadia; Haccard, Guillaume; Roller, Marc; Fromentin, Emilie

2016-08-01

The number of Americans older than 65 years old is projected to more than double in the next 40 years. Cognitive changes associated to aging can affect an adult's day-to-day functioning. Among these cognitive changes, reasoning, episodic memory, working memory, and processing speed decline gradually over time. Early memory changes include a decline in both working and episodic memory. The aim of the present study was to determine whether chronic (up to 75 days) daily administration of wild blueberry extract or a wild blueberry full spectrum powder would help prevent memory failure associated with aging in tasks involving various forms of memory. Both blueberry ingredients were used in a study comparing young mice (6 months old) to aged mice (18 months old). At this age, mice exhibit memory decline due to aging, which is exacerbated first by a loss in working and contextual (episodic-like) memory. Contextual memory (episodic-like memory) was evaluated using the contextual serial discrimination test. Working and spatial memory were evaluated using the Morris-Water maze test and the sequential alternation test. Statistical analysis was performed using an ANOVA with the Bonferroni post-hoc test. Supplementation with wild blueberry full spectrum powder and wild blueberry extract resulted in significant improvement of contextual memory, while untreated aged mice experienced a decline in such memory. Only the wild blueberry full spectrum powder significantly contributed to an improvement of spatial and working memory versus untreated aged mice. These improvements of cognitive performance may be related to brain oxidative status, acetylcholinesterase activity, neuroprotection, or attenuation of immunoreactivity. Georg Thieme Verlag KG Stuttgart · New York.

Collagen VI Null Mice as a Model for Early Onset Muscle Decline in Aging.

PubMed

Capitanio, Daniele; Moriggi, Manuela; De Palma, Sara; Bizzotto, Dario; Molon, Sibilla; Torretta, Enrica; Fania, Chiara; Bonaldo, Paolo; Gelfi, Cecilia; Braghetta, Paola

2017-01-01

Collagen VI is an extracellular matrix (ECM) protein playing a key role in skeletal muscles and whose deficiency leads to connective tissue diseases in humans and in animal models. However, most studies have been focused on skeletal muscle features. We performed an extensive proteomic profiling in two skeletal muscles (diaphragm and gastrocnemius) of wild-type and collagen VI null ( Col6a1 -/- ) mice at different ages, from 6- (adult) to 12- (aged) month-old to 24 (old) month-old. While in wild-type animals the number of proteins and the level of modification occurring during aging were comparable in the two analyzed muscles, Col6a1 -/- mice displayed a number of muscle-type specific variations. In particular, gastrocnemius displayed a limited number of dysregulated proteins in adult mice, while in aged muscles the modifications were more pronounced in terms of number and level. In diaphragm, the differences displayed by 6-month-old Col6a1 -/- mice were more pronounced compared to wild-type mice and persisted at 12 months of age. In adult Col6a1 -/- mice, the major variations were found in the enzymes belonging to the glycolytic pathway and the tricarboxylic acid (TCA) cycle, as well as in autophagy-related proteins. When compared to wild-type animals Col6a1 -/- mice displayed a general metabolic rewiring which was particularly prominent the diaphragm at 6 months of age. Comparison of the proteomic features and the molecular analysis of metabolic and autophagic pathways in adult and aged Col6a1 -/- diaphragm indicated that the effects of aging, culminating in lipotoxicity and autophagic impairment, were already present at 6 months of age. Conversely, the effects of aging in Col6a1 -/- gastrocnemius were similar but delayed becoming apparent at 12 months of age. A similar metabolic rewiring and autophagic impairment was found in the diaphragm of 24-month-old wild-type mice, confirming that fatty acid synthase (FASN) increment and decreased microtubule

Transcervical Inoculation with Chlamydia trachomatis Induces Infertility in HLA-DR4 Transgenic and Wild-Type Mice.

PubMed

Pal, Sukumar; Tifrea, Delia F; Zhong, Guangming; de la Maza, Luis M

2018-01-01

Chlamydia trachomatis is the leading cause of infection-induced infertility in women. Attempts to control this epidemic with screening programs and antibiotic therapy have failed. Currently, a vaccine to prevent C. trachomatis infections is not available. In order to develop an animal model for evaluating vaccine antigens that can be applied to humans, we used C. trachomatis serovar D (strain UW-3/Cx) to induce infertility in mice whose major histocompatibility complex class II antigen was replaced with the human leukocyte antigen DR4 (HLA-DR4). Transcervical inoculation of medroxyprogesterone-treated HLA-DR4 transgenic mice with 5 × 10 5 C. trachomatis D inclusion forming units (IFU) induced a significant reduction in fertility, with a mean number of embryos/mouse of 4.4 ± 1.3 compared to 7.8 ± 0.5 for the uninfected control mice ( P < 0.05). A similar fertility reduction was elicited in the wild-type (WT) C57BL/6 mice (4.3 ± 1.4 embryos/mouse) compared to the levels of the WT controls (9.1 ± 0.4 embryos/mouse) ( P < 0.05). Following infection, WT mice mounted more robust humoral and cellular immune responses than HLA-DR4 mice. As determined by vaginal shedding, HLA-DR4 mice were more susceptible to a transcervical C. trachomatis D infection than WT mice. To assess if HLA-DR4 transgenic and WT mice could be protected by vaccination, 10 4 IFU of C. trachomatis D was delivered intranasally, and mice were challenged transcervically 6 weeks later with 5 × 10 5 IFU of C. trachomatis D. As determined by severity and length of vaginal shedding, WT C57BL/6 and HLA-DR4 mice were significantly protected by vaccination. The advantages and limitations of the HLA-DR4 transgenic mouse model for evaluating human C. trachomatis vaccine antigens are discussed. Copyright © 2017 American Society for Microbiology.

Interferon-alpha/beta deficiency greatly exacerbates arthritogenic disease in mice infected with wild-type chikungunya virus but not with the cell culture-adapted live-attenuated 181/25 vaccine candidate

PubMed Central

Gardner, Christina L.; Burke, Crystal W.; Higgs, Stephen T.; Klimstra, William B.; Ryman, Kate D.

2012-01-01

In humans, chikungunya virus (CHIKV) infection causes fever, rash, and acute and persisting polyarthalgia/arthritis associated with joint swelling. We report a new CHIKV disease model in adult mice that distinguishes the wild-type CHIKV-LR strain from the live-attenuated vaccine strain (CHIKV-181/25). Although eight-week old normal mice inoculated in the hind footpad developed no hind limb swelling with either virus, CHIKV-LR replicated in musculoskeletal tissues and caused detectable inflammation. In mice deficient in STAT1-dependent interferon (IFN) responses, CHIKV-LR caused significant swelling of the inoculated and contralateral limbs and dramatic inflammatory lesions, while CHIKV-181/25 vaccine and another arthritogenic alphavirus, Sindbis, failed to induce swelling. IFN responses suppressed CHIKV-LR and CHIKV-181/25 replication equally in dendritic cells in vitro whereas macrophages were refractory to infection independently of STAT1-mediated IFN responses. Glycosaminoglycan (GAG) binding may be a CHIKV vaccine attenuation mechanism as CHIKV-LR infectivity was not dependent upon GAG, while CHIKV-181/25 was highly dependent. PMID:22305131

Sex and Immunogen-Specific Benefits of Immunotherapy Targeting Islet Amyloid Polypeptide in Transgenic and Wild-Type Mice

PubMed Central

Krishnamurthy, Pavan K.; Rajamohamedsait, Hameetha B.; Gonzalez, Veronica; Rajamohamedsait, Wajitha J.; Ahmed, Nawal; Krishnaswamy, Senthilkumar; Sigurdsson, Einar M.

2016-01-01

Type 2 diabetes mellitus is characterized by the deposition of islet amyloid polypeptide (IAPP) as amyloid in islets, a process thought to be toxic to β-cells. To determine the feasibility of targeting these aggregates therapeutically, we vaccinated transgenic (Tg) mice that overexpress human IAPP and were fed a high-fat diet to promote their diabetic phenotype. Our findings indicate that prophylactic vaccination with IAPP and its derivative IAPP7-19-TT, protects wild-type female mice, but not males, from obesity-induced early mortality, and the derivative showed a strong trend for prolonging the lifespan of Tg females but not males. Furthermore, IAPP7-19-TT-immunized Tg females cleared a glucose bolus more efficiently than controls, while IAPP-immunized Tg females showed an impaired ability to clear a glucose bolus compared to their adjuvant injected Tg controls. Interestingly, IAPP or IAPP7-19-TT treatments had no effect on glucose clearance in Tg males. Overall, these beneficial effects of IAPP targeted immunization depend on Tg status, sex, and immunogen. Hence, future studies in this field should carefully consider these variables that clearly affect the therapeutic outcome. In conclusion, IAPP targeting immunotherapy may have benefits in patients with type 2 diabetes. PMID:27379014

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.

Cathepsin B-dependent motor neuron death after nerve injury in the adult mouse

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

Sun, Li; Wu, Zhou; Baba, Masashi

Research highlights: {yields} Cathepsin B (CB), a lysosomal cysteine protease, is expressed in neuron and glia. {yields} CB increased in hypogrossal nucleus neurons after nerve injury in adult mice. {yields} CB-deficiency significantly increased the mean survival ratio of injured neurons. {yields} Thus, CB plays a critical role in axotomy-induced neuronal death in adult mice. -- Abstract: There are significant differences in the rate of neuronal death after peripheral nerve injury between species. The rate of neuronal death of motor neurons after nerve injury in the adult rats is very low, whereas that in adult mice is relatively high. However, themore » understanding of the mechanism underlying axotomy-induced motor neuron death in adult mice is limited. Cathepsin B (CB), a typical cysteine lysosomal protease, has been implicated in three major morphologically distinct pathways of cell death; apoptosis, necrosis and autophagic cell death. The possible involvement of CB in the neuronal death of hypogrossal nucleus (HGN) neurons after nerve injury in adult mice was thus examined. Quantitative analyses showed the mean survival ratio of HGN neurons in CB-deficient (CB-/-) adult mice after nerve injury was significantly greater than that in the wild-type mice. At the same time, proliferation of microglia in the injured side of the HGN of CB-/- adult mice was markedly reduced compared with that in the wild-type mice. On the injured side of the HGN in the wild-type adult mice, both pro- and mature forms of CB markedly increased in accordance with the increase in the membrane-bound form of LC3 (LC3-II), a marker protein of autophagy. Furthermore, the increase in CB preceded an increase in the expression of Noxa, a major executor for axotomy-induced motor neuron death in the adult mouse. Conversely, expression of neither Noxa or LC3-II was observed in the HGN of adult CB-/- mice after nerve injury. These observations strongly suggest that CB plays a critical role in

On-going electroencephalographic rhythms related to cortical arousal in wild-type mice: the effect of aging.

PubMed

Del Percio, Claudio; Drinkenburg, Wilhelmus; Lopez, Susanna; Infarinato, Francesco; Bastlund, Jesper Frank; Laursen, Bettina; Pedersen, Jan T; Christensen, Ditte Zerlang; Forloni, Gianluigi; Frasca, Angelisa; Noè, Francesco M; Bentivoglio, Marina; Fabene, Paolo Francesco; Bertini, Giuseppe; Colavito, Valeria; Kelley, Jonathan; Dix, Sophie; Richardson, Jill C; Babiloni, Claudio

2017-01-01

Resting state electroencephalographic (EEG) rhythms reflect the fluctuation of cortical arousal and vigilance in a typical clinical setting, namely the EEG recording for few minutes with eyes closed (i.e., passive condition) and eyes open (i.e., active condition). Can this procedure be back-translated to C57 (wild type) mice for aging studies? On-going EEG rhythms were recorded from a frontoparietal bipolar channel in 85 (19 females) C57 mice. Male mice were subdivided into 3 groups: 25 young (4.5-6 months), 18 middle-aged (12-15 months), and 23 old (20-24 months) mice to test the effect of aging. EEG power density was compared between short periods (about 5 minutes) of awake quiet behavior (passive) and dynamic exploration of the cage (active). Compared with the passive condition, the active condition induced decreased EEG power at 1-2 Hz and increased EEG power at 6-10 Hz in the group of 85 mice. Concerning the aging effects, the passive condition showed higher EEG power at 1-2 Hz in the old group than that in the others. Furthermore, the active condition exhibited a maximum EEG power at 6-8 Hz in the former group and 8-10 Hz in the latter. In the present conditions, delta and theta EEG rhythms reflected changes in cortical arousal and vigilance in freely behaving C57 mice across aging. These changes resemble the so-called slowing of resting state EEG rhythms observed in humans across physiological and pathological aging. The present EEG procedures may be used to enhance preclinical phases of drug discovery in mice for understanding the neurophysiological effects of new compounds against brain aging. Copyright © 2016 Elsevier Inc. All rights reserved.

Early Cognitive/Social Deficits and Late Motor Phenotype in Conditional Wild-Type TDP-43 Transgenic Mice.

PubMed

Alfieri, Julio A; Silva, Pablo R; Igaz, Lionel M

2016-01-01

Frontotemporal Dementia (FTD) and amyotrophic lateral sclerosis (ALS) are two neurodegenerative diseases associated to mislocalization and aggregation of TAR DNA-binding protein 43 (TDP-43). To investigate in depth the behavioral phenotype associated with this proteinopathy, we used as a model transgenic (Tg) mice conditionally overexpressing human wild-type TDP 43 protein (hTDP-43-WT) in forebrain neurons. We previously characterized these mice at the neuropathological level and found progressive neurodegeneration and other features that evoke human TDP-43 proteinopathies of the FTD/ALS spectrum. In the present study we analyzed the behavior of mice at multiple domains, including motor, social and cognitive performance. Our results indicate that young hTDP-43-WT Tg mice (1 month after post-weaning transgene induction) present a normal motor phenotype compared to control littermates, as assessed by accelerated rotarod performance, spontaneous locomotor activity in the open field test and a mild degree of spasticity shown by a clasping phenotype. Analysis of social and cognitive behavior showed a rapid installment of deficits in social interaction, working memory (Y-maze test) and recognition memory (novel object recognition test) in the absence of overt motor abnormalities. To investigate if the motor phenotype worsen with age, we analyzed the behavior of mice after long-term (up to 12 months) transgene induction. Our results reveal a decreased performance on the rotarod test and in the hanging wire test, indicating a motor phenotype that was absent in younger mice. In addition, long-term hTDP-43-WT expression led to hyperlocomotion in the open field test. In sum, these results demonstrate a time-dependent emergence of a motor phenotype in older hTDP-43-WT Tg mice, recapitulating aspects of clinical FTD presentations with motor involvement in human patients, and providing a complementary animal model for studying TDP-43 proteinopathies.

Evaluation of nigrostriatal dopaminergic function in adult +/+ and +/- BDNF mutant mice.

PubMed

Dluzen, D E; Gao, X; Story, G M; Anderson, L I; Kucera, J; Walro, J M

2001-07-01

Deletion of a single copy of the BDNF gene has been shown to affect the nigrostriatal dopaminergic system of young adult BDNF mice. In the present report we evaluated various indices of nigrostriatal dopaminergic function between 9-month-old wild-type (+/+) and heterozygous (+/-) BDNF mutant mice. Performance in a sensorimotor beam walking task was significantly decreased in +/- mice as indicated by increased times required to traverse both a wide (21 mm) and narrow (6 mm) beam. No differences in spontaneous locomotor behavior were observed between the +/+ and +/- mice. Amphetamine-stimulated (5 mg/kg) locomotor behavior was increased to a greater degree in the +/- mice, with the number of movements performed by these mice being significantly greater than their +/+ controls. Corpus striatal dopamine concentrations were significantly greater in the +/- BDNF mice. The absence of any significant differences for dopamine concentrations within the hypothalamus and olfactory bulb of these mice, as well as an absence of any difference in striatal norepinephrine concentrations, suggested a relative specificity of these effects to the corpus striatum. Both the +/- and +/+ mice showed similar reductions in striatal dopamine concentrations in response to a neurotoxic regimen of methamphetamine (20 mg/kg). Collectively these data show increased levels of striatal dopamine concentrations associated with altered behavioral responses involving the nigrostriatal dopaminergic system within the heterozygous BDNF mutant mice. Copyright 2001 Academic Press.

Toll-Like Receptor 3 Is Critical for Coxsackievirus B4-Induced Type 1 Diabetes in Female NOD Mice

PubMed Central

Thuma, Jean R.; Courreges, Maria C.; Benencia, Fabian; James, Calvin B.L.; Malgor, Ramiro; Kantake, Noriko; Mudd, William; Denlinger, Nathan; Nolan, Bret; Wen, Li; Schwartz, Frank L.

2015-01-01

Group B coxsackieviruses (CVBs) are involved in triggering some cases of type 1 diabetes mellitus (T1DM). However, the molecular mechanism(s) responsible for this remain elusive. Toll-like receptor 3 (TLR3), a receptor that recognizes viral double-stranded RNA, is hypothesized to play a role in virus-induced T1DM, although this hypothesis is yet to be substantiated. The objective of this study was to directly investigate the role of TLR3 in CVB-triggered T1DM in nonobese diabetic (NOD) mice, a mouse model of human T1DM that is widely used to study both spontaneous autoimmune and viral-induced T1DM. As such, we infected female wild-type (TLR3+/+) and TLR3 knockout (TLR3−/−) NOD mice with CVB4 and compared the incidence of diabetes in CVB4-infected mice with that of uninfected counterparts. We also evaluated the islets of uninfected and CVB4-infected wild-type and TLR3 knockout NOD mice by immunohistochemistry and insulitis scoring. TLR3 knockout mice were markedly protected from CVB4-induced diabetes compared with CVB4-infected wild-type mice. CVB4-induced T-lymphocyte-mediated insulitis was also significantly less severe in TLR3 knockout mice compared with wild-type mice. No differences in insulitis were observed between uninfected animals, either wild-type or TLR3 knockout mice. These data demonstrate for the first time that TLR3 is 1) critical for CVB4-induced T1DM, and 2) modulates CVB4-induced insulitis in genetically prone NOD mice. PMID:25422874

Determination of pharmacokinetics of chrysin and its conjugates in wild-type FVB and Bcrp1 knockout mice using a validated LC-MS/MS method.

PubMed

Ge, Shufan; Gao, Song; Yin, Taijun; Hu, Ming

2015-03-25

Chrysin, a flavone found in many plants, is also available as a dietary supplement because of its reported anticancer activities. However, its bioavailability is very poor due to extensive phase II metabolism. The purpose of this study was to develop an UPLC-MS/MS method to simultaneously quantify chrysin and its phase II metabolites, and to determine its pharmacokinetics in FVB wild-type and Bcrp knockout (Bcrp1 -/-) mice. In addition, the role of BCRP in chrysin phase II disposition was further investigated in Caco-2 cells. The results showed that our sensitive and reproducible UPLC-MS/MS method was successfully applied to the pharmacokinetic study of chrysin in wild-type and Bcrp1 (-/-) FVB mice after oral administration (20 mg/kg). Although there was no significant change in systemic exposure of chrysin and its metabolites, it was found that the Tmax for chrysin glucuronide was significantly shorter (p < 0.01) in Bcrp1-deficient mice. Furthermore, it was shown that inhibition of BCRP by Ko143 significantly reduced the efflux of chrysin sulfate in Caco-2 cells. In conclusion, BCRP had significant but less than expected impact on pharmacokinetics of chrysin and its conjugates, which were determined using a newly developed and validated LC-MS/MS method.

Histone acetylation rescues contextual fear conditioning in nNOS KO mice and accelerates extinction of cued fear conditioning in wild type mice.

PubMed

Itzhak, Yossef; Anderson, Karen L; Kelley, Jonathan B; Petkov, Martin

2012-05-01

Epigenetic regulation of chromatin structure is an essential molecular mechanism that contributes to the formation of synaptic plasticity and long-term memory (LTM). An important regulatory process of chromatin structure is acetylation and deacetylation of histone proteins. Inhibition of histone deacetylase (HDAC) increases acetylation of histone proteins and facilitate learning and memory. Nitric oxide (NO) signaling pathway has a role in synaptic plasticity, LTM and regulation of histone acetylation. We have previously shown that NO signaling pathway is required for contextual fear conditioning. The present study investigated the effects of systemic administration of the HDAC inhibitor sodium butyrate (NaB) on fear conditioning in neuronal nitric oxide synthase (nNOS) knockout (KO) and wild type (WT) mice. The effect of single administration of NaB on total H3 and H4 histone acetylation in hippocampus and amygdala was also investigated. A single administration of NaB prior to fear conditioning (a) rescued contextual fear conditioning of nNOS KO mice and (b) had long-term (weeks) facilitatory effect on the extinction of cued fear memory of WT mice. The facilitatory effect of NaB on extinction of cued fear memory of WT mice was confirmed in a study whereupon NaB was administered during extinction. Results suggest that (a) the rescue of contextual fear conditioning in nNOS KO mice is associated with NaB-induced increase in H3 histone acetylation and (b) the accelerated extinction of cued fear memory in WT mice is associated with NaB-induced increase in H4 histone acetylation. Hence, a single administration of HDAC inhibitor may rescue NO-dependent cognitive deficits and afford a long-term accelerating effect on extinction of fear memory of WT mice. Copyright © 2012 Elsevier Inc. All rights reserved.

The usage of a three-compartment model to investigate the metabolic differences between hepatic reductase null and wild-type mice.

PubMed

Hill, Lydia; Chaplain, Mark A J; Wolf, Roland; Kapelyukh, Yury

2017-03-01

The Cytochrome P450 (CYP) system is involved in 90% of the human body's interactions with xenobiotics and due to this, it has become an area of avid research including the creation of transgenic mice. This paper proposes a three-compartment model which is used to explain the drug metabolism in the Hepatic Reductase Null (HRN) mouse developed by the University of Dundee (Henderson, C. J., Otto, D. M. E., Carrie, D., Magnuson, M. A., McLaren, A. W., Rosewell, I. and Wolf, C. R. (2003) Inactivation of the hepatic cytochrome p450 system by conditional deletion of hepatic cytochrome p450 reductase. J. Biol. Chem. , 13480-13486). The model is compared with a two-compartment model using experimental data from studies using wild-type and HRN mice. This comparison allowed for metabolic differences between the two types of mice to be isolated. The three sets of drug data (Gefitinib, Midazolam and Thalidomide) showed that the transgenic mouse has a decreased rate of metabolism. © The authors 2015. Published by Oxford University Press on behalf of the Institute of Mathematics and its Applications. All rights reserved.

No effect of running and laboratory housing on adult hippocampal neurogenesis in wild caught long-tailed wood mouse

PubMed Central

Hauser, Thomas; Klaus, Fabienne; Lipp, Hans-Peter; Amrein, Irmgard

2009-01-01

Background Studies of adult hippocampal neurogenesis (AHN) in laboratory rodents have raised hopes for therapeutic interventions in neurodegenerative diseases and mood disorders, as AHN can be modulated by physical exercise, stress and environmental changes in these animals. Since it is not known whether cell proliferation and neurogenesis in wild living mice can be experimentally changed, this study investigates the responsiveness of AHN to voluntary running and to environmental change in wild caught long-tailed wood mice (Apodemus sylvaticus). Results Statistical analyses show that running had no impact on cell proliferation (p = 0.44), neurogenesis (p = 0.94) or survival of newly born neurons (p = 0.58). Likewise, housing in the laboratory has no effect on AHN. In addition, interindividual differences in the level of neurogenesis are not related to interindividual differences of running wheel performance (rs = -0.09, p = 0.79). There is a correlation between the number of proliferating cells and the number of cells of neuronal lineage (rs = 0.63, p < 0.001) and the number of pyknotic cells (rs = 0.5, p = 0.009), respectively. Conclusion Plasticity of adult neurogenesis is an established feature in strains of house mice and brown rats. Here, we demonstrate that voluntary running and environmental changes which are effective in house mice and brown rats cannot influence AHN in long-tailed wood mice. This indicates that in wild long-tailed wood mice different regulatory mechanisms act on cell proliferation and neurogenesis. If this difference reflects a species-specific adaptation or a broader adaptive strategy to a natural vs. domestic environment is unknown. PMID:19419549

Collagen VI Null Mice as a Model for Early Onset Muscle Decline in Aging

PubMed Central

Capitanio, Daniele; Moriggi, Manuela; De Palma, Sara; Bizzotto, Dario; Molon, Sibilla; Torretta, Enrica; Fania, Chiara; Bonaldo, Paolo; Gelfi, Cecilia; Braghetta, Paola

2017-01-01

Collagen VI is an extracellular matrix (ECM) protein playing a key role in skeletal muscles and whose deficiency leads to connective tissue diseases in humans and in animal models. However, most studies have been focused on skeletal muscle features. We performed an extensive proteomic profiling in two skeletal muscles (diaphragm and gastrocnemius) of wild-type and collagen VI null (Col6a1−/−) mice at different ages, from 6- (adult) to 12- (aged) month-old to 24 (old) month-old. While in wild-type animals the number of proteins and the level of modification occurring during aging were comparable in the two analyzed muscles, Col6a1−/− mice displayed a number of muscle-type specific variations. In particular, gastrocnemius displayed a limited number of dysregulated proteins in adult mice, while in aged muscles the modifications were more pronounced in terms of number and level. In diaphragm, the differences displayed by 6-month-old Col6a1−/− mice were more pronounced compared to wild-type mice and persisted at 12 months of age. In adult Col6a1−/− mice, the major variations were found in the enzymes belonging to the glycolytic pathway and the tricarboxylic acid (TCA) cycle, as well as in autophagy-related proteins. When compared to wild-type animals Col6a1−/− mice displayed a general metabolic rewiring which was particularly prominent the diaphragm at 6 months of age. Comparison of the proteomic features and the molecular analysis of metabolic and autophagic pathways in adult and aged Col6a1−/− diaphragm indicated that the effects of aging, culminating in lipotoxicity and autophagic impairment, were already present at 6 months of age. Conversely, the effects of aging in Col6a1−/− gastrocnemius were similar but delayed becoming apparent at 12 months of age. A similar metabolic rewiring and autophagic impairment was found in the diaphragm of 24-month-old wild-type mice, confirming that fatty acid synthase (FASN) increment and decreased

Cellular FLIP can substitute for the herpes simplex virus type 1 latency-associated transcript gene to support a wild-type virus reactivation phenotype in mice

PubMed Central

Jin, Ling; Carpenter, Dale; Moerdyk-Schauwecker, Megan; Vanarsdall, Adam L; Osorio, Nelson; Hsiang, Chinhui; Jones, Clinton; Wechsler, Steven L

2010-01-01

Latency-associated transcript (LAT) deletion mutants of herpes simplex virus type 1 (HSV-1) have reduced reactivation phenotypes. Thus, LAT plays an essential role in the latency-reactivation cycle of HSV-1. We have shown that LAT has antiapoptosis activity and demonstrated that the chimeric virus, dLAT-cpIAP, resulting from replacing LAT with the baculovirus antiapoptosis gene cpIAP, has a wild-type HSV-1 reactivation phenotype in mice and rabbits. Thus, LAT can be replaced by an alternative antiapoptosis gene, confirming that LAT’s antiapoptosis activity plays an important role in the mechanism by which LAT enhances the virus’ reactivation phenotype. However, because cpIAP interferes with both of the major apoptosis pathways, these studies did not address whether LAT’s proreactivation phenotype function was due to blocking the extrinsic (Fas-ligand–, caspase-8–, or caspase-10–dependent pathway) or the intrinsic (mitochondria-, caspase-9–dependent pathway) pathway, or whether both pathways must be blocked. Here we constructed an HSV-1 LAT(−) mutant that expresses cellular FLIP (cellular FLICE-like inhibitory protein) under control of the LAT promoter and in place of LAT nucleotides 76 to 1667. Mice were ocularly infected with this mutant, designated dLAT-FLIP, and the reactivation phenotype was determined using the trigeminal ganglia explant model. dLAT-FLIP had a reactivation phenotype similar to wild-type virus and significantly higher than the LAT(−) mutant dLAT2903. Thus, the LAT function responsible for enhancing the reactivation phenotype could be replaced with an antiapoptosis gene that primarily blocks the extrinsic signaling apoptosis pathway. PMID:18989818

Evaluation of Electrical Impedance as a Biomarker of Myostatin Inhibition in Wild Type and Muscular Dystrophy Mice.

PubMed

Sanchez, Benjamin; Li, Jia; Yim, Sung; Pacheck, Adam; Widrick, Jeffrey J; Rutkove, Seward B

2015-01-01

Non-invasive and effort independent biomarkers are needed to better assess the effects of drug therapy on healthy muscle and that affected by muscular dystrophy (mdx). Here we evaluated the use of multi-frequency electrical impedance for this purpose with comparison to force and histological parameters. Eight wild-type (wt) and 10 mdx mice were treated weekly with RAP-031 activin type IIB receptor at a dose of 10 mg kg-1 twice weekly for 16 weeks; the investigators were blinded to treatment and disease status. At the completion of treatment, impedance measurements, in situ force measurements, and histology analyses were performed. As compared to untreated animals, RAP-031 wt and mdx treated mice had greater body mass (18% and 17%, p < 0.001 respectively) and muscle mass (25% p < 0.05 and 22% p < 0.001, respectively). The Cole impedance parameters in treated wt mice, showed a 24% lower central frequency (p < 0.05) and 19% higher resistance ratio (p < 0.05); no significant differences were observed in the mdx mice. These differences were consistent with those seen in maximum isometric force, which was greater in the wt animals (p < 0.05 at > 70 Hz), but not in the mdx animals. In contrast, maximum force normalized by muscle mass was unchanged in the wt animals and lower in the mdx animals by 21% (p < 0.01). Similarly, myofiber size was only non-significantly higher in treated versus untreated animals (8% p = 0.44 and 12% p = 0.31 for wt and mdx animals, respectively). Our findings demonstrate electrical impedance of muscle reproduce the functional and histological changes associated with myostatin pathway inhibition and do not reflect differences in muscle size or volume. This technique deserves further study in both animal and human therapeutic trials.

Effect of nerve injury on the number of dorsal root ganglion neurons and autotomy behavior in adult Bax-deficient mice.

PubMed

Lyu, Chuang; Lyu, Gong-Wei; Martinez, Aurora; Shi, Tie-Jun Sten

2017-01-01

The proapoptotic molecule BAX, plays an important role in mitochondrial apoptotic pathway. Dorsal root ganglion (DRG) neurons depend on neurotrophic factors for survival at early developmental stages. Withdrawal of neurotrophic factors will induce apoptosis in DRG neurons, but this type of cell death can be delayed or prevented in neonatal Bax knockout (KO) mice. In adult animals, evidence also shows that DRG neurons are less dependent upon neurotrophic factors for survival. However, little is known about the effect of Bax deletion on the survival of normal and denervated DRG neurons in adult mice. A unilateral sciatic nerve transection was performed in adult Bax KO mice and wild-type (WT) littermates. Stereological method was employed to quantify the number of lumbar-5 DRG neurons 1 month post-surgery. Nerve injury-induced autotomy behavior was also examined on days 1, 3, and 7 post-surgery. There were significantly more neurons in contralateral DRGs of KO mice as compared with WT mice. The number of neurons was reduced in ipsilateral DRGs in both KO and WT mice. No changes in size distributions of DRG neuron profiles were detected before or after nerve injury. Injury-induced autotomy behavior developed much earlier and was more serious in KO mice. Although postnatal death or loss of DRG neurons is partially prevented by Bax deletion, this effect cannot interfere with long-term nerve injury-induced neuronal loss. The exaggerated self-amputation behavior observed in the mutant mice indicates that Bax deficiency may enhance the development of spontaneous pain following nerve injury.

The Psen1-L166P-knock-in mutation leads to amyloid deposition in human wild-type amyloid precursor protein YAC transgenic mice

PubMed Central

Vidal, Ruben; Sammeta, Neeraja; Garringer, Holly J.; Sambamurti, Kumar; Miravalle, Leticia; Lamb, Bruce T.; Ghetti, Bernardino

2012-01-01

Genetically engineered mice have been generated to model cerebral β-amyloidosis, one of the hallmarks of Alzheimer disease (AD) pathology, based on the overexpression of a mutated cDNA of the amyloid-β precursor protein (AβPP) or by knock-in of the murine Aβpp gene alone or with presenilin1 mutations. Here we describe the generation and initial characterization of a new mouse line based on the presence of 2 copies of the human genomic region encoding the wild-type AβPP and the L166P presenilin 1 mutation. At ∼6 mo of age, double-mutant mice develop amyloid pathology, with signs of neuritic dystrophy, intracellular Aβ accumulation, and glial inflammation, an increase in AβPP C-terminal fragments, and an 8 times increase in Aβ42 levels with a 40% decrease in Aβ40 levels, leading to a significant increase (14 times) of Aβ42/Aβ40 ratios, with minimal effects on presenilin or the Notch1 pathway in the brain. We conclude that in mice, neither mutations in AβPP nor overexpression of an AβPP isoform are a prerequisite for Aβ pathology. This model will allow the study of AD pathogenesis and testing of therapeutic strategies in a more relevant environment without experimental artifacts due to the overexpression of a single-mutant AβPP isoform using exogenous promoters.—Vidal, R., Sammeta, N., Garringer, H. J., Sambamurti, K., Miravalle, L., Lamb B. T., Ghetti, B. The Psen1-L166P-knock-in mutation leads to amyloid deposition in human wild-type amyloid precursor protein YAC transgenic mice. PMID:22459153

Significance and Regional Dependency of Peptide Transporter (PEPT) 1 in the Intestinal Permeability of Glycylsarcosine: In Situ Single-Pass Perfusion Studies in Wild-Type and Pept1 Knockout Mice

PubMed Central

Jappar, Dilara; Wu, Shu-Pei; Hu, Yongjun

2010-01-01

The purpose of this study was to evaluate the role, relevance, and regional dependence of peptide transporter (PEPT) 1 expression and function in mouse intestines using the model dipeptide glycylsarcosine (GlySar). After isolating specific intestinal segments, in situ single-pass perfusions were performed in wild-type and Pept1 knockout mice. The permeability of [3H]GlySar was measured as a function of perfusate pH, dipeptide concentration, potential inhibitors, and intestinal segment, along with PEPT1 mRNA and protein. We found the permeability of GlySar to be saturable (Km = 5.7 mM), pH-dependent (maximal value at pH 5.5), and specific for PEPT1; other peptide transporters, such as PHT1 and PHT2, were not involved, as judged by the lack of GlySar inhibition by excess concentrations of histidine. GlySar permeabilities were comparable in the duodenum and jejunum of wild-type mice but were much larger than that in ileum (approximately 2-fold). A PEPT1-mediated permeability was not observed for GlySar in the colon of wild-type mice (<10% residual uptake compared to proximal small intestine). Moreover, GlySar permeabilities were very low and not different in the duodenum, jejunum, ileum, and colon of Pept1 knockout mice. Functional activity of intestinal PEPT1 was confirmed by real-time polymerase chain reaction and immunoblot analyses. Our findings suggest that a loss of PEPT1 activity (e.g., due to polymorphisms, disease, or drug interactions) should have a major effect in reducing the intestinal absorption of di-/tripeptides, peptidomimetics, and peptide-like drugs. PMID:20660104

Time Courses of Cortical Glucose Metabolism and Microglial Activity Across the Life Span of Wild-Type Mice: A PET Study.

PubMed

Brendel, Matthias; Focke, Carola; Blume, Tanja; Peters, Finn; Deussing, Maximilian; Probst, Federico; Jaworska, Anna; Overhoff, Felix; Albert, Nathalie; Lindner, Simon; von Ungern-Sternberg, Barbara; Bartenstein, Peter; Haass, Christian; Kleinberger, Gernot; Herms, Jochen; Rominger, Axel

2017-12-01

Contrary to findings in the human brain, 18 F-FDG PET shows cerebral hypermetabolism of aged wild-type (WT) mice relative to younger animals, supposedly due to microglial activation. Therefore, we used dual-tracer small-animal PET to examine directly the link between neuroinflammation and hypermetabolism in aged mice. Methods: WT mice (5-20 mo) were investigated in a cross-sectional design using 18 F-FDG ( n = 43) and translocator protein (TSPO) ( 18 F-GE180; n = 58) small-animal PET, with volume-of-interest and voxelwise analyses. Biochemical analysis of plasma cytokine levels and immunohistochemical confirmation of microglial activity were also performed. Results: Age-dependent cortical hypermetabolism in WT mice relative to young animals aged 5 mo peaked at 14.5 mo (+16%, P < 0.001) and declined to baseline at 20 mo. Similarly, cortical TSPO binding increased to a maximum at 14.5 mo (+15%, P < 0.001) and remained high to 20 mo, resulting in an overall correlation between 18 F-FDG uptake and TSPO binding (R = 0.69, P < 0.005). Biochemical and immunohistochemical analyses confirmed the TSPO small-animal PET findings. Conclusion: Age-dependent neuroinflammation is associated with the controversial observation of cerebral hypermetabolism in aging WT mice. © 2017 by the Society of Nuclear Medicine and Molecular Imaging.

Perseveration by NK1R-/- (‘knockout’) mice is blunted by doses of methylphenidate that affect neither other aspects of their cognitive performance nor the behaviour of wild-type mice in the 5-Choice Continuous Performance Test

PubMed Central

Pillidge, Katharine; Porter, Ashley J; Young, Jared W; Stanford, S Clare

2016-01-01

The underlying cause(s) of abnormalities expressed by patients with attention deficit hyperactivity disorder (ADHD) have yet to be delineated. One factor that has been associated with increased vulnerability to ADHD is polymorphism(s) of TACR1, which is the human equivalent of the rodent NK1 (substance P-preferring) receptor gene (Nk1r). We have reported previously that genetically altered mice, lacking functional NK1R (NK1R–/–), express locomotor hyperactivity, which was blunted by the first-line treatment for ADHD, methylphenidate. Here, we compared the effects of this psychostimulant (3, 10 and 30 mg/kg, intraperitoneally) on the behaviour of NK1R-/- mice and their wild types in the 5-Choice Continuous Performance Test, which emulates procedures used to study attention and response control in ADHD patients. Methylphenidate increased total trials (a measure of ‘productivity’) completed by wild types, but not by NK1R-/- mice. Conversely, this drug reduced perseveration by NK1R-/- mice, but not by wild types. Other drug-induced changes in key behaviours were not genotype dependent, especially at the highest dose: for example, % omissions (an index of inattentiveness) was increased, whereas % false alarms and % premature responses (measures of impulsivity) declined in both genotypes, indicating reduced overall response. These findings are discussed in the context of the efficacy of methylphenidate in the treatment of ADHD. Moreover, they lead to several testable proposals. First, methylphenidate does not improve attention in a subgroup of ADHD patients with a functional deficit of TACR1. Second, these patients do not express excessive false alarms when compared with other groups of subjects, but they do express excessive perseveration, which would be ameliorated by methylphenidate. PMID:27097734

DNA beta-amyloid(1-42) trimer immunization for Alzheimer disease in a wild-type mouse model.

PubMed

Lambracht-Washington, Doris; Qu, Bao-Xi; Fu, Min; Eagar, Todd N; Stüve, Olaf; Rosenberg, Roger N

2009-10-28

DNA beta-amyloid(1-42) (Abeta42) trimer immunization was developed to produce specific T helper 2 cell (T(H)2)-type antibodies to provide an effective and safe therapy for Alzheimer disease (AD) by reducing elevated levels of Abeta42 peptide that occur in the brain of patients with AD. To compare the immune response in wild-type mice after immunization with DNA Abeta42 trimer and Abeta42 peptide. Wild-type mice received either 4 microg of DNA Abeta42 trimer immunization administered with gene gun (n = 8) or intraperitoneal injection of 100 microg of human Abeta42 peptide with the adjuvant Quil A (n = 8). Titers, epitope mapping, and isotypes of the Abeta42-specific antibodies were analyzed. Antibody titers, mapping of binding sites (epitopes), isotype profiles of the Abeta42-specific antibodies, and T-cell activation. DNA Abeta42 trimer immunization resulted in antibody titers with a mean of 15 microg per milliliter of plasma. The isotype profile of the antibodies differed markedly. A predominant IgG1 antibody response was found in the DNA-immunized mice, indicating a T(H)2 type of immune response (IgG1/IgG2a ratio of 10). The peptide-immunized mice showed a mixed T(H)1/T(H)2 immune response (IgG1/IgG2a ratio of 1) (P < .001). No increased T-cell proliferation was observed in the DNA-immunized mice (P = .03). In this preliminary study in a wild-type mouse model, DNA Abeta42 trimer immunization protocol produced a T(H)2 immune response and appeared to have low potential to cause an inflammatory T-cell response.

A Longitudinal Study of Cognition, Proton MR Spectroscopy and Synaptic and Neuronal Pathology in Aging Wild-type and AβPPswe-PS1dE9 Mice

PubMed Central

Jansen, Diane; Zerbi, Valerio; Janssen, Carola I. F.; Dederen, Pieter J. W. C.; Mutsaers, Martina P. C.; Hafkemeijer, Anne; Janssen, Anna-Lena; Nobelen, Cindy L. M.; Veltien, Andor; Asten, Jack J.; Heerschap, Arend; Kiliaan, Amanda J.

2013-01-01

Proton magnetic resonance spectroscopy (1H MRS) is a valuable tool in Alzheimer’s disease research, investigating the functional integrity of the brain. The present longitudinal study set out to characterize the neurochemical profile of the hippocampus, measured by single voxel 1H MRS at 7 Tesla, in the brains of AβPPSswe-PS1dE9 and wild-type mice at 8 and 12 months of age. Furthermore, we wanted to determine whether alterations in hippocampal metabolite levels coincided with behavioral changes, cognitive decline and neuropathological features, to gain a better understanding of the underlying neurodegenerative processes. Moreover, correlation analyses were performed in the 12-month-old AβPP-PS1 animals with the hippocampal amyloid-β deposition, TBS-T soluble Aβ levels and high-molecular weight Aβ aggregate levels to gain a better understanding of the possible involvement of Aβ in neurochemical and behavioral changes, cognitive decline and neuropathological features in AβPP-PS1 transgenic mice. Our results show that at 8 months of age AβPPswe-PS1dE9 mice display behavioral and cognitive changes compared to age-matched wild-type mice, as determined in the open field and the (reverse) Morris water maze. However, there were no variations in hippocampal metabolite levels at this age. AβPP-PS1 mice at 12 months of age display more severe behavioral and cognitive impairment, which coincided with alterations in hippocampal metabolite levels that suggest reduced neuronal integrity. Furthermore, correlation analyses suggest a possible role of Aβ in inflammatory processes, synaptic dysfunction and impaired neurogenesis. PMID:23717459

Inducible knockdown of pregnancy-associated plasma protein-A gene expression in adult female mice extends life span.

PubMed

Bale, Laurie K; West, Sally A; Conover, Cheryl A

2017-08-01

Pregnancy-associated plasma protein-A (PAPP-A) knockout (KO) mice, generated through homologous recombination in embryonic stem cells, have a significantly increased lifespan compared to wild-type littermates. However, it is unknown whether this longevity advantage would pertain to PAPP-A gene deletion in adult animals. In the present study, we used tamoxifen (Tam)-inducible Cre recombinase-mediated excision of the floxed PAPP-A (fPAPP-A) gene in mice at 5 months of age. fPAPP-A mice, which were either positive (pos) or negative (neg) for Tam-Cre, received Tam treatment with quarterly boosters. Only female mice could be used with this experimental design. fPAPP-A/neg and fPAPP-A/pos mice had similar weights at the start of the experiment and showed equivalent weight gain. We found that fPAPP-A/pos mice had a significant extension of life span (P = 0.005). The median life span was increased by 21% for fPAPP-A/pos compared to fPAPP-A/neg mice. Analysis of mortality in life span quartiles indicated that the proportion of deaths of fPAPP-A/pos mice were lower than fPAPP-A/neg mice at young adult ages (P = 0.002 for 601-800 days) and higher than fPAPP-A/neg mice at older ages (P = 0.004 for >1000 days). Thus, survival curves and age-specific mortality indicate that female mice with knockdown of PAPP-A gene expression as adults have an extended healthy life span. © 2017 The Authors. Aging Cell published by the Anatomical Society and John Wiley & Sons Ltd.

Delay-dependent working memory impairment in young-adult and aged 5-HT1BKO mice as assessed in a radial-arm water maze.

PubMed

Wolff, Mathieu; Benhassine, Narimane; Costet, Pierre; Hen, Rene; Segu, Louis; Buhot, Marie-Christine

2003-01-01

Serotonin (5-HT) plays a modulatory role in mnemonic functions, especially by interacting with the cholinergic system. The 5-HT1B receptor is a key target of this interaction. The 5-HT1B receptor knockout mice were found previously to exhibit a facilitation in hippocampal-dependent spatial reference memory learning. In the present study, we submitted mice to a delayed spatial working memory task, allowing the introduction of various delays between an exposure trial and a test trial. The 5-HT1BKO and wild-type mice learned the task in a radial-arm water maze (returning to the most recent presented arm containing the escape platform), and exhibited a high level of performance at delays of 0 and 5 min. However, at the delay of 60 min, only 5-HT1BKO mice exhibited an impairment. At a delay of 90 min, all mice were impaired. Treatment by scopolamine (0.8 mg/kg) induced the same pattern of performance in wild type as did the mutation for short (5 min, no impairment) and long (60 min, impairment) delays. The 22-month-old wild-type and knockout mice exhibited an impairment at short delays (5 and 15 min). The effect of the mutation affected both young-adult and aged mice at delays of 15, 30, and 60 min. Neurobiological data show that stimulation of the 5-HT1B receptor inhibits the release of acetylcholine in the hippocampus, but stimulates this in the frontal cortex. This dual function might, at least in part, explain the opposite effect of the mutation on reference memory (facilitation) and delay-dependent working memory (impairment). These results support the idea that cholinergic-serotonergic interactions play an important role in memory processes.

Isolation of Novel Synthetic Prion Strains by Amplification in Transgenic Mice Coexpressing Wild-Type and Anchorless Prion Proteins

PubMed Central

Raymond, Gregory J.; Race, Brent; Hollister, Jason R.; Offerdahl, Danielle K.; Moore, Roger A.; Kodali, Ravindra; Raymond, Lynne D.; Hughson, Andrew G.; Rosenke, Rebecca; Long, Dan; Dorward, David W.

2012-01-01

Mammalian prions are thought to consist of misfolded aggregates (protease-resistant isoform of the prion protein [PrPres]) of the cellular prion protein (PrPC). Transmissible spongiform encephalopathy (TSE) can be induced in animals inoculated with recombinant PrP (rPrP) amyloid fibrils lacking mammalian posttranslational modifications, but this induction is inefficient in hamsters or transgenic mice overexpressing glycosylphosphatidylinositol (GPI)-anchored PrPC. Here we show that TSE can be initiated by inoculation of misfolded rPrP into mice that express wild-type (wt) levels of PrPC and that synthetic prion strain propagation and selection can be affected by GPI anchoring of the host's PrPC. To create prions de novo, we fibrillized mouse rPrP in the absence of molecular cofactors, generating fibrils with a PrPres-like protease-resistant banding profile. These fibrils induced the formation of PrPres deposits in transgenic mice coexpressing wt and GPI-anchorless PrPC (wt/GPI−) at a combined level comparable to that of PrPC expression in wt mice. Secondary passage into mice expressing wt, GPI−, or wt plus GPI− PrPC induced TSE disease with novel clinical, histopathological, and biochemical phenotypes. Contrary to laboratory-adapted mouse scrapie strains, the synthetic prion agents exhibited a preference for conversion of GPI− PrPC and, in one case, caused disease only in GPI− mice. Our data show that novel TSE agents can be generated de novo solely from purified mouse rPrP after amplification in mice coexpressing normal levels of wt and anchorless PrPC. These observations provide insight into the minimal elements required to create prions in vitro and suggest that the PrPC GPI anchor can modulate the propagation of synthetic TSE strains. PMID:22915801

Reversibility of dopamine receptor antagonist-induced hyperprolactinemia and associated histological changes in Tg RasH2 wild-type mice.

PubMed

Krishna, Gopala; Ganiger, Shivaputhrappa; Kannan, Kamala; Gopalakrishnan, Gopa; Goel, Saryu

2015-12-01

The purpose of this study was to better understand the biological effects of increased prolactin levels induced in mice by dopamine D2 receptor antagonist molindone treatment. Toxicokinetics, prolactin levels, and reproductive tissue histology were evaluated in Tg rasH2 wild-type mice treated orally with molindone at 0, 5, 15, and 50mg/kg/day for 6 months, followed by a 2-month posttreatment recovery period. A greater than dose-proportional increase in molindone exposure ([AUC]0‒24) was observed on Day 180 for both sexes. Statistically significant (P<0.01) increases in prolactin levels were observed in most treatment groups compared with controls at 0.5h postdose on Days 1 and 180. Prolactin levels returned to baseline levels during the recovery period. Microscopic changes attributable to hyperprolactinemia, including corpora lutea enlargement and interstitial cell atrophy in the ovaries, and atrophy of the uterus and vagina were observed on Day 180. These changes were reversed during the recovery period in the 5- and 15-mg/kg/day treatment groups. Mice receiving molindone at 50mg/kg/day also showed signs of reversal on histologic examination. Copyright © 2015 Elsevier Inc. All rights reserved.

Ablation of Prion Protein in Wild Type Human Amyloid Precursor Protein (APP) Transgenic Mice Does Not Alter The Proteolysis of APP, Levels of Amyloid-β or Pathologic Phenotype

PubMed Central

Baybutt, Herbert; Diack, Abigail B.; Kellett, Katherine A. B.; Piccardo, Pedro; Manson, Jean C.

2016-01-01

The cellular prion protein (PrPC) has been proposed to play an important role in the pathogenesis of Alzheimer’s disease. In cellular models PrPC inhibited the action of the β-secretase BACE1 on wild type amyloid precursor protein resulting in a reduction in amyloid-β (Aβ) peptides. Here we have assessed the effect of genetic ablation of PrPC in transgenic mice expressing human wild type amyloid precursor protein (line I5). Deletion of PrPC had no effect on the α- and β-secretase proteolysis of the amyloid precursor protein (APP) nor on the amount of Aβ38, Aβ40 or Aβ42 in the brains of the mice. In addition, ablation of PrPC did not alter Aβ deposition or histopathology phenotype in this transgenic model. Thus using this transgenic model we could not provide evidence to support the hypothesis that PrPC regulates Aβ production. PMID:27447728

Brown adipose tissue dynamics in wild-type and UCP1-knockout mice: in vivo insights with magnetic resonance[S

PubMed Central

Grimpo, Kirsten; Völker, Maximilian N.; Heppe, Eva N.; Braun, Steve; Heverhagen, Johannes T.; Heldmaier, Gerhard

2014-01-01

We used noninvasive magnetic resonance imaging (MRI) and magnetic resonance spectroscopy to compare interscapular brown adipose tissue (iBAT) of wild-type (WT) and uncoupling protein 1 (UCP1)-knockout mice lacking UCP1-mediated nonshivering thermogenesis (NST). Mice were sequentially acclimated to an ambient temperature of 30°C, 18°C, and 5°C. We detected a remodeling of iBAT and a decrease in its lipid content in all mice during cold exposure. Ratios of energy-rich phosphates (ATP/ADP, phosphocreatine/ATP) in iBAT were maintained stable during noradrenergic stimulation of thermogenesis in cold- and warm-adapted mice and no difference between the genotypes was observed. As free fatty acids (FFAs) serve as fuel for thermogenesis and activate UCP1 for uncoupling of oxidative phosphorylation, brown adipose tissue is considered to be a main acceptor and consumer of FFAs. We measured a major loss of FFAs from iBAT during noradrenergic stimulation of thermogenesis. This mobilization of FFAs was observed in iBAT of WT mice as well as in mice lacking UCP1. The high turnover and the release of FFAs from iBAT suggests an enhancement of lipid metabolism, which in itself contributes to the sympathetically activated NST and which is independent from uncoupled respiration mediated by UCP1. Our study demonstrates that MRI, besides its potential for visualizing and quantification of fat tissue, is a valuable tool for monitoring functional in vivo processes like lipid and phosphate metabolism during NST. PMID:24343897

Sex- and age-related differences in the chronic pressure-natriuresis relationship: role of the angiotensin type 2 receptor.

PubMed

Mirabito, Katrina M; Hilliard, Lucinda M; Kett, Michelle M; Brown, Russell D; Booth, Sean C; Widdop, Robert E; Moritz, Karen M; Evans, Roger G; Denton, Kate M

2014-10-15

Sex hormones regulate the renin-angiotensin system. For example, estrogen enhances expression of the angiotensin type 2 receptor. We hypothesized that activation of the angiotensin type 2 receptor shifts the chronic pressure-natriuresis relationship leftward in females compared with males and that this effect is lost with age. Mean arterial pressure was measured by radiotelemetry in adult (4 mo old) and aged (14 mo old) wild-type and angiotensin type 2 receptor knockout male and female mice. Chronic pressure-natriuresis curves were constructed while mice were maintained on a normal-salt (0.26%) diet and following 6 days of high salt (5.0%) diet. Mean arterial pressure was lower in adult wild-type females than males (88 ± 1 and 97 ± 1 mmHg, respectively), a difference that was maintained with age, but was absent in adult knockout mice. In wild-type females, the chronic pressure-natriuresis relationship was shifted leftward compared with knockout females, an effect that was lost with age. In males, the chronic pressure-natriuresis relationship was not influenced by angiotensin type 2 receptor deficiency. Compared with age-matched females, the chronic pressure-natriuresis relationships in male mice were shifted rightward. Renal expression of the angiotensin type 2 receptor was fourfold greater in adult wild-type females than males. With age, the angiotensin type 2 receptor-to-angiotensin type 1 receptor balance was reduced in females. Conversely, in males, angiotensin receptor expression did not vary significantly with age. In conclusion, the angiotensin type 2 receptor modulates the chronic pressure-natriuresis relationship in an age- and sex-dependent manner. Copyright © 2014 the American Physiological Society.

Increased anxiety and fear memory in adult mice lacking type 2 deiodinase.

PubMed

Bárez-López, Soledad; Montero-Pedrazuela, Ana; Bosch-García, Daniel; Venero, César; Guadaño-Ferraz, Ana

2017-10-01

A euthyroid state in the brain is crucial for its adequate development and function. Impairments in thyroid hormones (THs; T3 or 3,5,3'-triiodothyronine and T4 or thyroxine) levels and availability in brain can lead to neurological alterations and to psychiatric disorders, particularly mood disorders. The thyroid gland synthetizes mainly T4, which is secreted to circulating blood, however, most actions of THs are mediated by T3, the transcriptionally active form. In the brain, intracellular concentrations of T3 are modulated by the activity of type 2 (D2) and type 3 (D3) deiodinases. In the present work, we evaluated learning and memory capabilities and anxiety-like behavior at adult stages in mice lacking D2 (D2KO) and we analyzed the impact of D2-deficiency on TH content and on the expression of T3-dependent genes in the amygdala and the hippocampus. We found that D2KO mice do not present impairments in spatial learning and memory, but they display emotional alterations with increased anxiety-like behavior as well as enhanced auditory-cued fear memory and spontaneous recovery of fear memory following extinction. D2KO mice also presented reduced T3 content in the hippocampus and decreased expression of the T3-dependent gene Dio3 in the amygdala suggesting a hypothyroid status in this structure. We propose that the emotional dysfunctions found in D2KO mice can arise from the reduced T3 content in their brain, which consequently leads to alterations in gene expression with functional consequences. We found a downregulation in the gene encoding for the calcium-binding protein calretinin (Calb2) in the amygdala of D2KO mice that could affect the GABAergic transmission. The current findings in D2KO mice can provide insight into emotional disorders present in humans with DIO2 polymorphisms. Copyright © 2017 Elsevier Ltd. All rights reserved.

Placental Glucose and Amino Acid Transport in Calorie-Restricted Wild-Type and Glut3 Null Heterozygous Mice

PubMed Central

Ganguly, Amit; Collis, Laura

2012-01-01

Calorie restriction (CR) decreased placenta and fetal weights in wild-type (wt) and glucose transporter (Glut) 3 heterozygous null (glut3+/−) mice. Because placental nutrient transport is a primary energy determinant of placentofetal growth, we examined key transport systems. Maternal CR reduced intra- and transplacental glucose and leucine transport but enhanced system A amino acid transport in wt mice. These transport perturbations were accompanied by reduced placental Glut3 and leucine amino acid transporter (LAT) family member 2, no change in Glut1 and LAT family member 1, but increased sodium coupled neutral amino acid transporter (SNAT) and SNAT2 expression. We also noted decreased total and active phosphorylated forms of mammalian target of rapamycin, which is the intracellular nutrient sensor, the downstream total P70S6 kinase, and pS6 ribosomal protein with no change in total and phosphorylated 4E-binding protein 1. To determine the role of placental Glut3 in mediating CR-induced placental transport changes, we next investigated the effect of gestational CR in glut3+/− mice. In glut3+/− mice, a key role of placental Glut3 in mediating transplacental and intraplacental glucose transport was established. In addition, reduced Glut3 results in a compensatory increase of leucine and system A transplacental transport. On the other hand, diminished Glut3-mediated intraplacental glucose transport reduced leucine transport and mammalian target of rapamycin and preserved LAT and enhancing SNAT. CR in glut3+/− mice further reduced transplacental glucose transport and enhanced system A amino acid transport, although the increased leucine transport was lost. In addition, increased Glut3 was seen and preserved Glut1, LAT, and SNAT. These placental changes collectively protect survival of wt and glut3+/− fetuses against maternal CR-imposed reduction of macromolecular nutrients. PMID:22700768

Placental glucose and amino acid transport in calorie-restricted wild-type and Glut3 null heterozygous mice.

PubMed

Ganguly, Amit; Collis, Laura; Devaskar, Sherin U

2012-08-01

Calorie restriction (CR) decreased placenta and fetal weights in wild-type (wt) and glucose transporter (Glut) 3 heterozygous null (glut3(+/-)) mice. Because placental nutrient transport is a primary energy determinant of placentofetal growth, we examined key transport systems. Maternal CR reduced intra- and transplacental glucose and leucine transport but enhanced system A amino acid transport in wt mice. These transport perturbations were accompanied by reduced placental Glut3 and leucine amino acid transporter (LAT) family member 2, no change in Glut1 and LAT family member 1, but increased sodium coupled neutral amino acid transporter (SNAT) and SNAT2 expression. We also noted decreased total and active phosphorylated forms of mammalian target of rapamycin, which is the intracellular nutrient sensor, the downstream total P70S6 kinase, and pS6 ribosomal protein with no change in total and phosphorylated 4E-binding protein 1. To determine the role of placental Glut3 in mediating CR-induced placental transport changes, we next investigated the effect of gestational CR in glut3(+/-) mice. In glut3(+/-) mice, a key role of placental Glut3 in mediating transplacental and intraplacental glucose transport was established. In addition, reduced Glut3 results in a compensatory increase of leucine and system A transplacental transport. On the other hand, diminished Glut3-mediated intraplacental glucose transport reduced leucine transport and mammalian target of rapamycin and preserved LAT and enhancing SNAT. CR in glut3(+/-) mice further reduced transplacental glucose transport and enhanced system A amino acid transport, although the increased leucine transport was lost. In addition, increased Glut3 was seen and preserved Glut1, LAT, and SNAT. These placental changes collectively protect survival of wt and glut3(+/-) fetuses against maternal CR-imposed reduction of macromolecular nutrients.

Bone turnover in wild type and pleiotrophin-transgenic mice housed for three months in the International Space Station (ISS).

PubMed

Tavella, Sara; Ruggiu, Alessandra; Giuliani, Alessandra; Brun, Francesco; Canciani, Barbara; Manescu, Adrian; Marozzi, Katia; Cilli, Michele; Costa, Delfina; Liu, Yi; Piccardi, Federica; Tasso, Roberta; Tromba, Giuliana; Rustichelli, Franco; Cancedda, Ranieri

2012-01-01

Bone is a complex dynamic tissue undergoing a continuous remodeling process. Gravity is a physical force playing a role in the remodeling and contributing to the maintenance of bone integrity. This article reports an investigation on the alterations of the bone microarchitecture that occurred in wild type (Wt) and pleiotrophin-transgenic (PTN-Tg) mice exposed to a near-zero gravity on the International Space Station (ISS) during the Mice Drawer System (MDS) mission, to date, the longest mice permanence (91 days) in space. The transgenic mouse strain over-expressing pleiotrophin (PTN) in bone was selected because of the PTN positive effects on bone turnover. Wt and PTN-Tg control animals were maintained on Earth either in a MDS payload or in a standard vivarium cage. This study revealed a bone loss during spaceflight in the weight-bearing bones of both strains. For both Tg and Wt a decrease of the trabecular number as well as an increase of the mean trabecular separation was observed after flight, whereas trabecular thickness did not show any significant change. Non weight-bearing bones were not affected. The PTN-Tg mice exposed to normal gravity presented a poorer trabecular organization than Wt mice, but interestingly, the expression of the PTN transgene during the flight resulted in some protection against microgravity's negative effects. Moreover, osteocytes of the Wt mice, but not of Tg mice, acquired a round shape, thus showing for the first time osteocyte space-related morphological alterations in vivo. The analysis of specific bone formation and resorption marker expression suggested that the microgravity-induced bone loss was due to both an increased bone resorption and a decreased bone deposition. Apparently, the PTN transgene protection was the result of a higher osteoblast activity in the flight mice.

Flt3 Ligand Regulates the Development of Innate Lymphoid Cells in Fetal and Adult Mice.

PubMed

Baerenwaldt, Anne; von Burg, Nicole; Kreuzaler, Matthias; Sitte, Selina; Horvath, Edit; Peter, Annick; Voehringer, David; Rolink, Antonius G; Finke, Daniela

2016-03-15

Flt3 ligand (Flt3L) promotes survival of lymphoid progenitors in the bone marrow and differentiation of dendritic cells (DCs), but its role in regulating innate lymphoid cells (ILCs) during fetal and adult life is not understood. By using Flt3L knockout and transgenic mice, we demonstrate that Flt3L controls ILC numbers by regulating the pool of α4β7(-) and α4β7(+) lymphoid tissue inducer cell progenitors in the fetal liver and common lymphoid progenitors in the bone marrow. Deletion of flt3l severely reduced the number of fetal liver progenitors and lymphoid tissue inducer cells in the neonatal intestine, resulting in impaired development of Peyer's patches. In the adult intestine, NK cells and group 2 and 3 ILCs were severely reduced. This effect occurred independently of DCs as ILC numbers were normal in mice in which DCs were constitutively deleted. Finally, we could show that administration of Flt3L increased the number of NKp46(-) group 3 ILCs in wild-type and even in Il7(-/-) mice, which generally have reduced numbers of ILCs. Taken together, Flt3L significantly contributes to ILC and Peyer's patches development by targeting lymphoid progenitor cells during fetal and adult life. Copyright © 2016 by The American Association of Immunologists, Inc.

Speed-Dependent Modulation of the Locomotor Behavior in Adult Mice Reveals Attractor and Transitional Gaits.

PubMed

Lemieux, Maxime; Josset, Nicolas; Roussel, Marie; Couraud, Sébastien; Bretzner, Frédéric

2016-01-01

Locomotion results from an interplay between biomechanical constraints of the muscles attached to the skeleton and the neuronal circuits controlling and coordinating muscle activities. Quadrupeds exhibit a wide range of locomotor gaits. Given our advances in the genetic identification of spinal and supraspinal circuits important to locomotion in the mouse, it is now important to get a better understanding of the full repertoire of gaits in the freely walking mouse. To assess this range, young adult C57BL/6J mice were trained to walk and run on a treadmill at different locomotor speeds. Instead of using the classical paradigm defining gaits according to their footfall pattern, we combined the inter-limb coupling and the duty cycle of the stance phase, thus identifying several types of gaits: lateral walk, trot, out-of-phase walk, rotary gallop, transverse gallop, hop, half-bound, and full-bound. Out-of-phase walk, trot, and full-bound were robust and appeared to function as attractor gaits (i.e., a state to which the network flows and stabilizes) at low, intermediate, and high speeds respectively. In contrast, lateral walk, hop, transverse gallop, rotary gallop, and half-bound were more transient and therefore considered transitional gaits (i.e., a labile state of the network from which it flows to the attractor state). Surprisingly, lateral walk was less frequently observed. Using graph analysis, we demonstrated that transitions between gaits were predictable, not random. In summary, the wild-type mouse exhibits a wider repertoire of locomotor gaits than expected. Future locomotor studies should benefit from this paradigm in assessing transgenic mice or wild-type mice with neurotraumatic injury or neurodegenerative disease affecting gait.

Alterations in Oral [1-14C] 18:1n-9 Distribution in Lean Wild-Type and Genetically Obese (ob/ob) Mice

PubMed Central

Wang, Xinxia; Feng, Jie; Yu, Caihua; Shen, Qingwu W.; Wang, Yizhen

2015-01-01

Obesity may result from altered fatty acid (FA) disposal. Altered FA distribution in obese individuals is poorly understood. Lean wild-type C57BL/6J and obese C57BL/6Job/ob mice received an oral dose of [1-14C]18:1n-9 (oleic acid), and the radioactivity in tissues was evaluated at various time points. The 14C concentration decreased rapidly in gastrointestinal tract but gradually increased and peaked at 96 h in adipose tissue, muscle and skin in lean mice. The 14C concentration was constant in adipose tissue and muscle of obese mice from 4h to 168h. 14C-label content in adipose tissue was significantly affected by genotype, whereas muscle 14C-label content was affected by genotype, time and the interaction between genotype and time. There was higher total 14C retention (47.7%) in obese mice than in lean mice (9.0%) at 168 h (P<0.05). The 14C concentrations in the soleus and gastrocnemius muscle were higher in obese mice than in lean mice (P<0.05). Perirenal adipose tissue contained the highest 14C content in lean mice, whereas subcutaneous adipose tissue (SAT) had the highest 14C content and accounted for the largest proportion of total radioactivity among fat depots in obese mice. More lipid radioactivity was recovered as TAG in SAT from obese mice than from lean mice (P<0.05). Gene expression suggested acyl CoA binding protein and fatty acid binding protein are important for FA distribution in adipose tissue and muscle. The FA distribution in major tissues was altered in ob/ob mice, perhaps contributing to obesity. Understanding the disparity in FA disposal between lean and obese mice may reveal novel targets for the treatment and prevention of obesity. PMID:25826747

Transplantation of Embryonic Cerebellar Grafts Improves Gait Parameters in Ataxic Lurcher Mice.

PubMed

Babuska, Vaclav; Houdek, Zbynek; Tuma, Jan; Purkartova, Zdenka; Tumova, Jana; Kralickova, Milena; Vozeh, Frantisek; Cendelin, Jan

2015-12-01

Hereditary cerebellar ataxias are severe diseases for which therapy is currently not sufficiently effective. One of the possible therapeutic approaches could be neurotransplantation. Lurcher mutant mice are a natural model of olivocerebellar degeneration representing a tool to investigate its pathogenesis as well as experimental therapies for hereditary cerebellar ataxias. The effect of intracerebellar transplantation of embryonic cerebellar solid tissue or cell suspension on motor performance in adult Lurcher mutant and healthy wild-type mice was studied. Brain-derived neurotrophic factor level was measured in the graft and adult cerebellar tissue. Gait analysis and rotarod, horizontal wire, and wooden beam tests were carried out 2 or 6 months after the transplantation. Higher level of the brain-derived neurotrophic factor was found in the Lurcher cerebellum than in the embryonic and adult wild-type tissue. A mild improvement of gait parameters was found in graft-treated Lurcher mice. The effect was more marked in cell suspension grafts than in solid transplants and after the longer period than after the short one. Lurcher mice treated with cell suspension and examined 6 months later had a longer hind paw stride (4.11 vs. 3.73 mm, P < 0.05) and higher swing speed for both forepaws (52.46 vs. 32.79 cm/s, P < 0.01) and hind paws (63.46 vs. 43.67 cm/s, P < 0.001) than controls. On the other hand, classical motor tests were not capable of detecting clearly the change in the motor performance. No strong long-lasting negative effect of the transplantation was seen in wild-type mice, suggesting that the treatment has no harmful impact on the healthy cerebellum.

DNA β-Amyloid1–42 Trimer Immunization for Alzheimer Disease in a Wild-Type Mouse Model

PubMed Central

Lambracht-Washington, Doris; Qu, Bao-Xi; Fu, Min; Eagar, Todd N.; Stüve, Olaf; Rosenberg, Roger N.

2010-01-01

Context DNA β-amyloid1–42 (Aβ42) trimer immunization was developed to produce specific T helper 2 cell (TH2)–type antibodies to provide an effective and safe therapy for Alzheimer disease (AD) by reducing elevated levels of Aβ42 peptide that occur in the brain of patients with AD. Objective To compare the immune response in wild-type mice after immunization with DNA Aβ42 trimer and Aβ42 peptide. Design and Intervention Wild-type mice received either 4 µg of DNA Aβ42 trimer immunization administered with gene gun (n=8) or intraperitoneal injection of 100 µg of human Aβ42 peptide with the adjuvant Quil A (n=8). Titers, epitope mapping, and isotypes of the Aβ42-specific antibodies were analyzed. Main Outcome Measures Antibody titers, mapping of binding sites (epitopes), isotype profiles of the Aβ42-specific antibodies, and T-cell activation. Results DNA Aβ42 trimer immunization resulted in antibody titers with a mean of 15 µg per milliliter of plasma. The isotype profile of the antibodies differed markedly. A predominant IgG1 antibody response was found in the DNA-immunized mice, indicating a TH2 type of immune response (IgG1/IgG2a ratio of 10). The peptide-immunized mice showed a mixed TH1/TH2 immune response (IgG1/IgG2a ratio of 1) (P<.001). No increased T-cell proliferation was observed in the DNA-immunized mice (P=.03). Conclusion In this preliminary study in a wild-type mouse model, DNA Aβ42 trimer immunization protocol produced a TH2 immune response and appeared to have low potential to cause an inflammatory T-cell response. PMID:19861672

Nfib hemizygous mice are protected from hyperoxic lung injury and death.

PubMed

Kumar, Vasantha H S; Chaker El Khoury, Joseph; Gronostajski, Richard; Wang, Huamei; Nielsen, Lori; Ryan, Rita M

2017-08-01

Nuclear Factor I ( Nfi) genes encode transcription factors essential for the development of organ systems including the lung. Nfib null mice die at birth with immature lungs. Nfib hemizygous mice have reduced lung maturation with decreased survival. We therefore hypothesized that these mice would be more sensitive to lung injury and would have lower survival to hyperoxia. Adult Nfib hemizygous mice and their wild-type (Wt) littermates were exposed to 100% O 2 for 89, 80, 72 and 66 h for survival studies with lung outcome measurements at 66 h. Nfib hemizygous and Wt controls were also studied in RA at 66 h. Cell counts and cytokines were measured in bronchoalveolar lavage (BAL); lung sections examined by histopathology; lung angiogenic and oxidative stress gene expression assessed by real-time PCR Unexpectedly, Nfib hemizygous mice (0/14-0%) had significantly lower mortality compared to Wt mice (10/22-45%) at 80 h of hyperoxia ( P  < 0.003). LD 50 was 80 h in the Wt group versus 89 h in the hemizygous group. There were no differences in BAL cell counts between the groups. Among the cytokines studied, MIP-2 was significantly lower in hemizygous mice exposed to hyperoxia. New vessel formation, edema, congestion, and alveolar hemorrhage were noted on histopathology at 72 and 80 h in wild-type mice. Nfib hemizygous lungs had significant downregulation of genes involved in redox signaling and inflammatory pathways. Adult Nfib hemizygous mice are relatively resistant to hyperoxia compared to wild-type littermates. Mechanisms contributing to this resistance are not clear; however, transcription factors such as Nfib may regulate cell survival and play a role in modulating postnatal lung development. © 2017 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of The Physiological Society and the American Physiological Society.

Targeted overexpression of endothelial nitric oxide synthase in endothelial cells improves cerebrovascular reactivity in Ins2Akita-type-1 diabetic mice.

PubMed

Chandra, Saurav B; Mohan, Sumathy; Ford, Bridget M; Huang, Lei; Janardhanan, Preethi; Deo, Kaiwalya S; Cong, Linlin; Muir, Eric R; Duong, Timothy Q

2016-06-01

Reduced bioavailability of nitric oxide due to impaired endothelial nitric oxide synthase (eNOS) activity is a leading cause of endothelial dysfunction in diabetes. Enhancing eNOS activity in diabetes is a potential therapeutic target. This study investigated basal cerebral blood flow and cerebrovascular reactivity in wild-type mice, diabetic mice (Ins2(Akita+/-)), nondiabetic eNOS-overexpressing mice (TgeNOS), and the cross of two transgenic mice (TgeNOS-Ins2(Akita+/-)) at six months of age. The cross was aimed at improving eNOS expression in diabetic mice. The major findings were: (i) Body weights of Ins2(Akita+/-) and TgeNOS-Ins2(Akita+/-) were significantly different from wild-type and TgeNOS mice. Blood pressure of TgeNOS mice was lower than wild-type. (ii) Basal cerebral blood flow of the TgeNOS group was significantly higher than cerebral blood flow of the other three groups. (iii) The cerebrovascular reactivity in the Ins2(Akita+/-) mice was significantly lower compared with wild-type, whereas that in the TgeNOS-Ins2(Akita+/-) was significantly higher compared with the Ins2(Akita+/-) and TgeNOS groups. Overexpression of eNOS rescued cerebrovascular dysfunction in diabetic animals, resulting in improved cerebrovascular reactivity. These results underscore the possible role of eNOS in vascular dysfunction in the brain of diabetic mice and support the notion that enhancing eNOS activity in diabetes is a potential therapeutic target. © The Author(s) 2015.

In vivo activation of Wnt signaling pathway enhances cognitive function of adult mice and reverses cognitive deficits in an Alzheimer's disease model.

PubMed

Vargas, Jessica Y; Fuenzalida, Marco; Inestrosa, Nibaldo C

2014-02-05

The role of the Wnt signaling pathway during synaptic development has been well established. In the adult brain, different components of Wnt signaling are expressed, but little is known about its role in mature synapses. Emerging in vitro studies have implicated Wnt signaling in synaptic plasticity. Furthermore, activation of Wnt signaling has shown to protect against amyloid-β-induced synaptic impairment. The present study provides the first evidence that in vivo activation of Wnt signaling improves episodic memory, increases excitatory synaptic transmission, and enhances long-term potentiation in adult wild-type mice. Moreover, the activation of Wnt signaling also rescues memory loss and improves synaptic dysfunction in APP/PS1-transgenic mice that model the amyloid pathology of Alzheimer's diseases. These findings indicate that Wnt signaling modulates cognitive function in the adult brain and could be a novel promising target for Alzheimer's disease therapy.

Glio-vascular changes during ageing in wild-type and Alzheimer's disease-like APP/PS1 mice.

PubMed

Janota, C S; Brites, D; Lemere, C A; Brito, M A

2015-09-16

Vascular and glial involvement in the development of neurodegenerative disorders, such as Alzheimer's disease (AD), and age-related brain vulnerabilities have been suggested. Therefore, we sought to: (i) investigate which vascular and glial events are evident in ageing and/or AD, (ii) to establish the temporal evolution of vascular and glial changes in AD-like and wild-type (WT) mice and (iii) to relate them to amyloid-β (Aβ) peptide accumulation. We examined immunohistochemically hippocampi and cortex from APP/PS1dE9 and WT C57BL/6 mice along ageing and disease progression (young-adulthood, middle- and old-age). Ageing resulted in the increase in receptor for advanced glycation endproducts expression, as well as the entrance of thrombin and albumin in hippocampal parenchyma. In contrast, the loss of platelet-derived growth factor receptor-β (PDGFR-β) positive cells, in both regions, was only related to AD pathogenesis. Hypovascularization was affected by both ageing and AD in the hippocampus, but resulted from the interaction between both factors in the cortex. Astrogliosis was a result of AD in hippocampus and of both factors in cortex, while microgliosis was associated with fibrillar amyloid plaques in AD-like mice and with the interaction between both factors in each of the studied regions. In sum, these data show that senile plaques precede vascular and glial alterations only in hippocampus, whereas in cortex, vascular and glial alterations, namely the loss of PDGFR-β-positive cells and astrogliosis, accompanied the first senile plaques. Hence, this study points to vascular and glial events that co-exist in AD pathogenesis and age-related brain vulnerabilities. Copyright © 2015 Elsevier B.V. All rights reserved.

Constitutive ω-3 fatty acid production in fat-1 transgenic mice and docosahexaenoic acid administration to wild type mice protect against 2,4,6-trinitrobenzene sulfonic acid-induced colitis.

PubMed

Yum, Hye-Won; Kang, Jing X; Hahm, Ki Baik; Surh, Young-Joon

2017-06-10

Omega-3 (ω-3) polyunsaturated fatty acids (PUFAs) are known to have strong anti-inflammatory effects. In the present study, we investigated the protective effects of ω-3 PUFAs on experimentally induced murine colitis. Intrarectal administration of 2.5% 2,4,6-trinitrobenzene sulfonic acid (TNBS) caused inflammation in the colon of wild type mice, but this was less severe in fat-1 transgenic mice that constitutively produce ω-3 PUFAs from ω-6 PUFAs. The intraperitoneal administration of docosahexaenoic acid (DHA), a representative ω-3 PUFA, was also protective against TNBS-induced murine colitis. In addition, endogenously formed and exogenously introduced ω-3 PUFAs attenuated the production of malondialdehyde and 4-hydroxynonenal in the colon of TNBS-treated mice. The effective protection against inflammatory and oxidative colonic tissue damages in fat-1 and DHA-treated mice was associated with suppression of NF-κB activation and cyclooxygenase-2 expression and with elevated activation of Nrf2 and upregulation of its target gene, heme oxygenase-1. Taken together, these results provide mechanistic basis of protective action of ω-3 fatty PUFAs against experimental colitis. Copyright © 2017. Published by Elsevier Inc.

Estrogen increases latencies to seizures and levels of 5α-pregnan-3α-ol-20-one in hippocampus of wild-type, but not 5α-reductase knockout, mice

PubMed Central

Osborne, Danielle M.; Frye, Cheryl A.

2013-01-01

Sex steroids can influence seizures. Estrogen (E2), progesterone (P4), and its metabolite, 5α-pregnan-3α-ol-20-one (3α,5α-THP), in particular, have received much attention for exerting these effects. Typically, it is thought that E2 precipitates seizures, and progestogens, such as P4 and 3α,5α-THP, attenuate seizures. However, E2 may also have antiseizure effects, perhaps in part through its enhancement of the formation of 3α,5α-THP, which has GABAA/benzodiazepine receptor agonist-like actions. To test this hypothesis, male and female, castrated or ovariectomized, wild-type and 5α-reductase knockout mice were implanted with Silastic capsules of E2 or vehicle and then administered pentylenetetrazol (85 mg/kg, ip). Wild-type, but not 5α-reductase knockout, mice administered E2 had significantly longer latencies to myoclonus and increased levels of 3α,5α-THP in the hippocampus. Thus, some of the anticonvulsive effects of E2 may involve formation of 3α,5α-THP in the hippocampus. PMID:19782646

The effect of dietary prebiotics and probiotics on body weight, large intestine indices, and fecal bile acid profile in wild type and IL10-/- mice.

PubMed

Kuo, Shiu-Ming; Merhige, Patricia M; Hagey, Lee R

2013-01-01

Previous studies have suggested roles of probiotics and prebiotics on body weight management and intestinal function. Here, the effects of a dietary prebiotic, inulin (50 mg/g diet), and probiotic, Bfidobacterium animalis subsp. lactis (Bb12) (final dose verified at 10(5) colony forming unit (cfu)/g diet, comparable to human consumption), were determined separately and in combination in mice using cellulose-based AIN-93G diets under conditions allowed for the growth of commensal bacteria. Continuous consumption of Bb12 and/or inulin did not affect food intake or body, liver, and spleen weights of young and adult mice. Fecal bile acid profiles were determined by nanoESI-MS/MS tandem mass spectrometry. In the presence of inulin, more bacterial deconjugation of taurine from primary bile acids was observed along with an increased cecal weight. Consumption of inulin in the absence or presence of Bb12 also increased the villus cell height in the proximal colon along with a trend of higher bile acid sulfation by intestinal cells. Feeding Bb12 alone at the physiological dose did not affect bile acid deconjugation and had little effect on other intestinal indices. Although interleukin (IL)10-null mice are susceptible to enterocolitis, they maintained the same body weight as the wild type mice under our specific pathogen-free housing condition and showed no signs of inflammation. Nevertheless, they had smaller cecum suggesting a mildly compromised intestinal development even before the disease manifestation. Our results are consistent with the notion that dietary factors such as prebiotics play important roles in the growth of intestinal microbiota and may impact on the intestinal health. In addition, fecal bile acid profiling could potentially be a non-invasive tool in monitoring the intestinal environment.

Type 2 diabetes impairs the ability of skeletal muscle pericytes to augment postischemic neovascularization in db/db mice.

PubMed

Hayes, Katherine L; Messina, Louis M; Schwartz, Lawrence M; Yan, Jinglian; Burnside, Amy S; Witkowski, Sarah

2018-05-01

Peripheral artery disease is an atherosclerotic occlusive disease that causes limb ischemia and has few effective noninterventional treatments. Stem cell therapy is promising, but concomitant diabetes may limit its effectiveness. We evaluated the therapeutic potential of skeletal muscle pericytes to augment postischemic neovascularization in wild-type and type 2 diabetic (T2DM) mice. Wild-type C57BL/6J and leptin receptor spontaneous mutation db/db T2DM mice underwent unilateral femoral artery excision to induce limb ischemia. Twenty-four hours after ischemia induction, CD45 - CD34 - CD146 + skeletal muscle pericytes or vehicle controls were transplanted into ischemic hindlimb muscles. At postoperative day 28, pericyte transplantation augmented blood flow recovery in wild-type mice (79.3 ± 5% vs. 61.9 ± 5%; P = 0.04), but not in T2DM mice (48.6% vs. 46.3 ± 5%; P = 0.51). Pericyte transplantation augmented collateral artery enlargement in wild-type (26.7 ± 2 μm vs. 22.3 ± 1 μm, P = 0.03), but not T2DM mice (20.4 ± 1.4 μm vs. 18.5 ± 1.2 μm, P = 0.14). Pericyte incorporation into collateral arteries was higher in wild-type than in T2DM mice ( P = 0.002). Unexpectedly, pericytes differentiated into Schwann cells in vivo. In vitro, Insulin increased Nox2 expression and decreased tubular formation capacity in human pericytes. These insulin-induced effects were reversed by N-acetylcysteine antioxidant treatment. In conclusion, T2DM impairs the ability of pericytes to augment neovascularization via decreased collateral artery enlargement and impaired engraftment into collateral arteries, potentially via hyperinsulinemia-induced oxidant stress. While pericytes show promise as a unique form of stem cell therapy to increase postischemic neovascularization, characterizing the molecular mechanisms by which T2DM impairs their function is essential to achieve their therapeutic potential.

Interspecies Variation in the Susceptibility of a Wild-Derived Colony of Mice to Pinworms (Aspiculuris tetraptera).

PubMed

Curtis, Ryan C; Murray, Jill K; Campbell, Polly; Nagamori, Yoko; Molnar, Adam; Jackson, Todd A

2017-01-01

Pinworms are common parasites in wild and laboratory rodents. Despite their relative nonpathogenicity in immunocompetent models, pinworm infections add an unwanted variable and may confound some types of research. For this reason, health monitoring programs and biosecurity measures aim to minimize the spread of pinworm infections into colonies free from the organisms. Wild-derived and laboratory strains of mice have shown varied susceptibility to infection with Aspiculuris tetraptera, the most commonly found murine pinworm. In particular, susceptibility is increased in wild-derived mice, young animals, and males. Routine surveillance at our institution revealed pinworm infection (A. tetraptera only) within a colony of multiple, wild-derived species of Mus, although only specific species showed positive results during initial sampling. To assess whether species-associated differences in susceptibility were present, we analyzed fecal egg counts of A. tetraptera in every cage of the colony. Our results revealed significant differences in susceptibility between various species and subspecies of Mus. Egg counts were significantly higher in Mus spicilegus than Mus m. domesticus (WSB/EiJ) and Mus macedonicus. Mus spretus had higher egg counts than M. m. domesticus (WSB/EiJ), M. m. musculus (PWK/PhJ), and M. macedonicus. Egg counts did not differ in regard to age, sex, or number of mice per cage. As wild-derived mouse models continue to compliment research largely based on laboratory strains, it will be important to understand host-parasite interactions and their effects on research, particularly studies evaluating immune responses, behavior, growth, and other physiologic parameters.

The type 2 cannabinoid receptor regulates susceptibility to osteoarthritis in mice.

PubMed

Sophocleous, A; Börjesson, A E; Salter, D M; Ralston, S H

2015-09-01

Cannabinoid receptors and their ligands have been implicated in the regulation of various physiological processes but their role in osteoarthritis has not been investigated. The aim of this study was to evaluate the role of the type 2 cannabinoid receptor (Cnr2) in regulating susceptibility to osteoarthritis in mice. We analysed the severity of knee osteoarthritis as assessed by the Osteoarthritis Research Society International (OARSI) scoring system in mice with targeted deletion of Cnr2 (Cnr2(-/-)) and wild type (WT) littermates. Studies were conducted in mice subjected to surgical destabilisation of the medial meniscus (DMM) and in those with spontaneous age-related osteoarthritis (OA). Osteoarthritis was more severe following DMM in the medial compartment of the knee in Cnr2(-/-) compared with WT mice (mean ± sem score = 4.9 ± 0.5 vs 3.6 ± 0.3; P = 0.017). Treatment of WT mice with the CB2-selective agonist HU308 following DMM reduced the severity of OA in the whole joint (HU308 = 8.4 ± 0.2 vs vehicle = 10.4 ± 0.6; P = 0.007). Spontaneous age related osteoarthritis was also more severe in the medial compartment of the knee in 12-month old Cnr2(-/-) mice compared with WT (5.6 ± 0.5 vs 3.5 ± 0.3, P = 0.008). Cultured articular chondrocytes from Cnr2(-/-) mice produced less proteoglycans in vitro than wild type chondrocytes. These studies demonstrate that the Cnr2 pathway plays a role in the pathophysiology of osteoarthritis in mice and shows that pharmacological activation of CB2 has a protective effect. Further studies of the role of cannabinoid receptors in the pathogenesis of osteoarthritis in man are warranted. Copyright © 2015 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.

FOLFIRI plus panitumumab in the treatment of wild-type KRAS and wild-type NRAS metastatic colorectal cancer.

PubMed

Geredeli, Caglayan; Yasar, Nurgul

2018-03-27

The aim of this study was to investigate the efficacy and safety of first-line panitumumab plus folinic acid, 5-fluorouracil and irinotecan (FOLFIRI) in patients with wild-type KRAS and wild-type NRAS metastatic colorectal cancer (mCRC). Patients with wild-type KRAS and wild-type NRAS mCRC presenting to the medical oncology department of the Okmeydani Training and Research Hospital in Istanbul, Turkey, between April 2014 and January 2018 were enrolled in this study. A total of 64 patients (35 males and 29 females) with a median age of 59 (35-81) years old were enrolled. The median follow-up was 18.9 months, and the median progression-free survival was 13 months. The median overall survival (OS) was 26 months in the patients with wild-type KRAS and wild-type NRAS mCRC. It was 90.4% for the 6-month OS, 79.5% for the 1-year OS, 53.7% for the 2-year OS and 31.1% for the 3-year OS. The median OS of the patients who underwent metastasectomies was 40 [95% confidence interval (CI) = 19.9-60.1] months, and the median OS of the patients without metastasectomies was 22 (95% CI = 17.7-26.4) months. There was a statistically significant difference between these (P = 0.007). The first-line FOLFIRI plus panitumumab was associated with favourable efficacy in the patients with wild-type KRAS and wild-type NRAS mCRC, and it was well tolerated. The removal of the metastases that became resectable after chemotherapy further prolonged the patients' survival. Retrospectively registered: 33886.

Decreased severity of experimental autoimmune arthritis in peptidylarginine deiminase type 4 knockout mice.

PubMed

Suzuki, Akari; Kochi, Yuta; Shoda, Hirofumi; Seri, Yu; Fujio, Keishi; Sawada, Tetsuji; Yamada, Ryo; Yamamoto, Kazuhiko

2016-05-05

Peptidylarginine deiminase type 4 (PADI4) has been identified as a susceptibility gene for rheumatoid arthritis (RA) by genome-wide association studies. PADI4 is highly expressed in the bone marrow, macrophages, neutrophils, and monocytes. Peptidyl citrulline is an interesting molecule in RA because it is a target antigen for anti-citrullinated peptide antibodies, and only PADs (translated proteins from PADI genes) can provide peptidyl citrulline via the modification of protein substrates. The aim of this study was to evaluate the importance of the PADI4 gene in the progression of RA. We generated Padi4 knockout (Padi4(-/-)) DBA1J mice. The Padi4(-/-) DBA1J and wild-type mice were immunized with bovine type II collagen (CII) to develop collagen-induced arthritis (CIA). The expression of various inflammatory cytokines and Padi genes in immune cells was detected by the real-time TaqMan assay. Cytokine concentrations in sera were measured by enzyme-linked immunosorbent assays. Localization of the PAD4 and PAD2 proteins was indicated by immunohistochemistry. We demonstrated that the clinical disease score was significantly decreased in the Padi4(-/-) mice and Padi4 expression was induced by CII immunization. In the Padi4(-/-) mice, serum anti-type II collagen (CII) immunoglobulin M (IgM), IgG, and inflammatory cytokine levels were significantly decreased compared with those in the wild-type mice. Padi2 expression was induced in the immune cells of the Padi4(-/-) mice as a compensation for the defect in Padi4. Padi4 affected disease severity in the CIA mice and was involved in the enhancement of the collagen-initiated inflammatory responses.

Microglial K+ Channel Expression in Young Adult and Aged Mice

PubMed Central

Schilling, Tom; Eder, Claudia

2015-01-01

The K+ channel expression pattern of microglia strongly depends on the cells' microenvironment and has been recognized as a sensitive marker of the cells' functional state. While numerous studies have been performed on microglia in vitro, our knowledge about microglial K+ channels and their regulation in vivo is limited. Here, we have investigated K+ currents of microglia in striatum, neocortex and entorhinal cortex of young adult and aged mice. Although almost all microglial cells exhibited inward rectifier K+ currents upon membrane hyperpolarization, their mean current density was significantly enhanced in aged mice compared with that determined in young adult mice. Some microglial cells additionally exhibited outward rectifier K+ currents in response to depolarizing voltage pulses. In aged mice, microglial outward rectifier K+ current density was significantly larger than in young adult mice due to the increased number of aged microglial cells expressing these channels. Aged dystrophic microglia exhibited outward rectifier K+ currents more frequently than aged ramified microglia. The majority of microglial cells expressed functional BK-type, but not IK- or SK-type, Ca2+-activated K+ channels, while no differences were found in their expression levels between microglia of young adult and aged mice. Neither microglial K+ channel pattern nor K+ channel expression levels differed markedly between the three brain regions investigated. It is concluded that age-related changes in microglial phenotype are accompanied by changes in the expression of microglial voltage-activated, but not Ca2+-activated, K+ channels. PMID:25472417

Lethal cutaneous disease in transgenic mice conditionally expressing type I human T cell leukemia virus Tax.

PubMed

Kwon, Hakju; Ogle, Louise; Benitez, Bobby; Bohuslav, Jan; Montano, Mauricio; Felsher, Dean W; Greene, Warner C

2005-10-21

Type I human T cell leukemia virus (HTLV-I) is etiologically linked with adult T cell leukemia, an aggressive and usually fatal expansion of activated CD4+ T lymphocytes that frequently traffic to skin. T cell transformation induced by HTLV-I involves the action of the 40-kDa viral Tax transactivator protein. Tax both stimulates the HTLV-I long terminal repeat and deregulates the expression of select cellular genes by altering the activity of specific host transcription factors, including cyclic AMP-responsive element-binding protein (CREB)/activating transcription factor, NF-kappaB/Rel, and serum response factor. To study initiating events involved in HTLV-I Tax-induced T cell transformation, we generated "Tet-off" transgenic mice conditionally expressing in a lymphocyte-restricted manner (EmuSR alpha promoter-enhancer) either wild-type Tax or mutant forms of Tax that selectively compromise the NF-kappaB (M22) or CREB/activating transcription factor (M47) activation pathways. Wild-type Tax and M47 Tax-expressing mice, but not M22-Tax expressing mice, developed progressive alopecia, hyperkeratosis, and skin lesions containing profuse activated CD4 T cell infiltrates with evidence of deregulated inflammatory cytokine production. In addition, these animals displayed systemic lymphadenopathy and splenomegaly. These findings suggest that Tax-mediated activation of NF-kappaB plays a key role in the development of this aggressive skin disease that shares several features in common with the skin disease occurring during the preleukemic stage in HTLV-I-infected patients. Of note, this skin disease completely resolved when Tax transgene expression was suppressed by administration of doxycycline, emphasizing the key role played by this viral oncoprotein in the observed pathology.

Wild-type presenilin 1 protects against Alzheimer disease mutation-induced amyloid pathology.

PubMed

Wang, Runsheng; Wang, Baiping; He, Wanxia; Zheng, Hui

2006-06-02

Mutations in presenilin 1 (PS1) lead to dominant inheritance of early onset familial Alzheimer disease (FAD). These mutations are known to alter the gamma-secretase cleavage of the amyloid precursor protein, resulting in increased ratio of Abeta42/Abeta40 and accelerated amyloid plaque pathology in transgenic mouse models. To investigate the factors that drive the Abeta42/Abeta40 ratio and amyloid pathogenesis and to investigate the possible interactions between wild-type and FAD mutant PS1, which are co-expressed in transgenic animals, we expressed the PS1 M146V knock-in allele either on wild-type PS1 (PS1M146V/+) or PS1 null (PS1M146V/-) background and crossed these alleles with the Tg2576 APP transgenic mice. Introduction of the PS1 M146V mutation on Tg2576 background resulted in earlier onset of plaque pathology. Surprisingly, removing the wild-type PS1 in the presence of the PS1 M146V mutation (PS1M146V/-) greatly exacerbated the amyloid burden; and this was attributed to a reduction of gamma-secretase activity rather than an increase in Abeta42. Our findings establish a protective role of the wild-type PS1 against the FAD mutation-induced amyloid pathology through a partial loss-of-function mechanism.

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

Effects of muscarinic receptor antagonists on cocaine discrimination in wild-type mice and in muscarinic receptor M1, M2, and M4 receptor knockout mice.

PubMed

Joseph, Lauren; Thomsen, Morgane

2017-06-30

Muscarinic M 1 /M 4 receptor stimulation can reduce abuse-related effects of cocaine and may represent avenues for treating cocaine addiction. Muscarinic antagonists can mimic and enhance effects of cocaine, including discriminative stimulus (S D ) effects, but the receptor subtypes mediating those effects are not known. A better understanding of the complex cocaine/muscarinic interactions is needed to evaluate and develop potential muscarinic-based medications. Here, knockout mice lacking M 1 , M 2 , or M 4 receptors (M 1 -/- , M 2 -/- , M 4 -/- ), as well as control wild-type mice and outbred Swiss-Webster mice, were trained to discriminate 10mg/kg cocaine from saline. Muscarinic receptor antagonists with no subtype selectivity (scopolamine), or preferential affinity at the M 1 , M 2 , or M 4 subtype (telenzepine, trihexyphenidyl; methoctramine, AQ-RA 741; tropicamide) were tested alone and in combination with cocaine. In intact animals, antagonists with high affinity at M 1 /M 4 receptors partially substituted for cocaine and increased the S D effect of cocaine, while M 2 -preferring antagonists did not substitute, and reduced the S D effect of cocaine. The cocaine-like effects of scopolamine were absent in M 1 -/- mice. The cocaine S D attenuating effects of methoctramine were absent in M 2 -/- mice and almost absent in M 1 -/- mice. The findings indicate that the cocaine-like S D effects of muscarinic antagonists are primarily mediated through M 1 receptors, with a minor contribution of M 4 receptors. The data also support our previous findings that stimulation of M 1 receptors and M 4 receptors can each attenuate the S D effect of cocaine, and show that this can also be achieved by blocking M 2 autoreceptors, likely via increased acetylcholine release. Copyright © 2017 Elsevier B.V. All rights reserved.

Impaired long-term memory and NR2A-type NMDA receptor-dependent synaptic plasticity in mice lacking c-Fos in the CNS.

PubMed

Fleischmann, Alexander; Hvalby, Oivind; Jensen, Vidar; Strekalova, Tatyana; Zacher, Christiane; Layer, Liliana E; Kvello, Ane; Reschke, Markus; Spanagel, Rainer; Sprengel, Rolf; Wagner, Erwin F; Gass, Peter

2003-10-08

The immediate early gene c-fos is part of the activator protein-1 transcription factor and has been postulated to participate in the molecular mechanisms of learning and memory. To test this hypothesis in vivo, we generated mice with a nervous system-specific c-fos knock-out using the Cre-loxP system. Adult mice lacking c-Fos in the CNS (c-fosDeltaCNS) showed normal general and emotional behavior but were specifically impaired in hippocampus-dependent spatial and associative learning tasks. These learning deficits correlated with a reduction of long-term potentiation (LTP) in hippocampal CA3-CA1 synapses. The magnitude of LTP was restored by a repeated tetanization procedure, suggesting impaired LTP induction in c-fosDeltaCNS mice. This rescue was blocked by a selective inhibitor of NR2B-type NMDA receptors. This blockade was compensated in wild-type mice by NR2A-type NMDA receptor-activated signaling pathways, thus indicating that these pathways are compromised in c-fosDeltaCNS mice. In summary, our data suggest a role for c-Fos in hippocampus-dependent learning and memory as well as in NMDA receptor-dependent LTP formation.

Activation of 5-HT7 serotonin receptors reverses metabotropic glutamate receptor-mediated synaptic plasticity in wild-type and Fmr1 knockout mice, a model of Fragile X syndrome.

PubMed

Costa, Lara; Spatuzza, Michela; D'Antoni, Simona; Bonaccorso, Carmela M; Trovato, Chiara; Musumeci, Sebastiano A; Leopoldo, Marcello; Lacivita, Enza; Catania, Maria V; Ciranna, Lucia

2012-12-01

Fragile X syndrome (FXS) is a genetic cause of intellectual disability and autism. Fmr1 knockout (Fmr1 KO) mice, an animal model of FXS, exhibit spatial memory impairment and synapse malfunctioning in the hippocampus, with abnormal enhancement of long-term depression mediated by metabotropic glutamate receptors (mGluR-LTD). The neurotransmitter serotonin (5-HT) modulates hippocampal-dependent learning through serotonin 1A (5-HT1A) and serotonin 7 (5-HT7) receptors; the underlying mechanisms are unknown. We used electrophysiology to test the effects of 5-HT on mGluR-LTD in wild-type and Fmr1 KO mice and immunocytochemistry and biotinylation assay to study related changes of 2-amino-3-(5-methyl-3-oxo-1,2-oxazol-4-yl)propanoic acid (AMPA) glutamate receptor surface expression. Application of 5-HT or 8-OH-DPAT (a mixed 5-HT1A/5-HT7 agonist) reversed mGluR-LTD in hippocampal slices. Reversal of mGluR-LTD by 8-OH-DPAT persisted in the presence of the 5-HT1A receptor antagonist WAY-100635, was abolished by SB-269970 (5-HT7 receptor antagonist), and was mimicked by LP-211, a novel selective 5-HT7 receptor agonist. Consistently, 8-OH-DPAT decreased mGluR-mediated reduction of AMPA glutamate receptor 2 (GluR2) subunit surface expression in hippocampal slices and cultured hippocampal neurons, an effect mimicked by LP-211 and blocked by SB-269970. In Fmr1 KO mice, mGluR-LTD was abnormally enhanced; similarly to wild-type, 8-OH-DPAT reversed mGluR-LTD and decreased mGluR-induced reduction of surface AMPA receptors, an effect antagonized by SB-269970. Serotonin 7 receptor activation reverses metabotropic glutamate receptor-induced AMPA receptor internalization and LTD both in wild-type and in Fmr1 KO mice, correcting excessive mGluR-LTD. Therefore, selective activation of 5-HT7 receptors may represent a novel strategy in the therapy of FXS. Copyright © 2012 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.

Long-chain fatty acid uptake by skeletal muscle is impaired in homozygous, but not heterozygous, heart-type-FABP null mice.

PubMed

Luiken, J J F P; Koonen, D P Y; Coumans, W A; Pelsers, M M A L; Binas, B; Bonen, A; Glatz, J F C

2003-04-01

Previous studies with cardiac myocytes from homozygous heart-type fatty acid (FA)-binding protein (H-FABP) -/- mice have indicated that this intracellular receptor protein for long-chain FA is involved in the cellular uptake of these substrates. Based on the knowledge that muscle FA uptake is a process highly sensitive to regulation by hormonal and mechanical stimuli, we studied whether H-FABP would play a role in this regulation. A suitable model system to answer this question is provided by H-FABP +/- mice, because in hindlimb muscles the content of H-FABP was measured to be 34% compared to wild-type mice. In these H-FABP +/- skeletal muscles, just as in H-FABP -/- muscles, contents of FA transporters, i.e., 43-kDa FABPpm and 88-kDa FAT/CD36, were similar compared to wild-type muscles, excluding possible compensatory mechanisms at the sarcolemmal level. Palmitate uptake rates were measured in giant vesicles prepared from hindlimb muscles of H-FABP -/-, H-FABP +/-, and H-FABP +/+ mice. For comparison, giant vesicles were isolated from liver, the tissue of which expresses a distinct type of FABP (i.e., L-FABP). Whereas in H-FABP -/- skeletal muscle FA uptake was reduced by 42-45%, FA uptake by H-FABP +/- skeletal muscle was not different from that in wild-type mice. In contrast, in liver from H-FABP -/- and from H-FABP +/- mice, FA uptake was not altered compared to wild-type animals, indicating that changes in FA uptake are restricted to H-FABP expressing tissues. It is concluded that H-FABP plays an important, yet merely permissive, role in FA uptake into muscle tissues.

DNA vaccines encoding proteins from wild-type and attenuated canine distemper virus protect equally well against wild-type virus challenge.

PubMed

Nielsen, Line; Jensen, Trine Hammer; Kristensen, Birte; Jensen, Tove Dannemann; Karlskov-Mortensen, Peter; Lund, Morten; Aasted, Bent; Blixenkrone-Møller, Merete

2012-10-01

Immunity induced by DNA vaccines containing the hemagglutinin (H) and nucleoprotein (N) genes of wild-type and attenuated canine distemper virus (CDV) was investigated in mink (Mustela vison), a highly susceptible natural host of CDV. All DNA-immunized mink seroconverted, and significant levels of virus-neutralizing (VN) antibodies were present on the day of challenge with wild-type CDV. The DNA vaccines also primed the cell-mediated memory responses, as indicated by an early increase in the number of interferon-gamma (IFN-γ)-producing lymphocytes after challenge. Importantly, the wild-type and attenuated CDV DNA vaccines had a long-term protective effect against wild-type CDV challenge. The vaccine-induced immunity induced by the H and N genes from wild-type CDV and those from attenuated CDV was comparable. Because these two DNA vaccines were shown to protect equally well against wild-type virus challenge, it is suggested that the genetic/antigenic heterogeneity between vaccine strains and contemporary wild-type strains are unlikely to cause vaccine failure.

Impaired long-term memory retention: common denominator for acutely or genetically reduced hippocampal neurogenesis in adult mice.

PubMed

Ben Abdallah, Nada M-B; Filipkowski, Robert K; Pruschy, Martin; Jaholkowski, Piotr; Winkler, Juergen; Kaczmarek, Leszek; Lipp, Hans-Peter

2013-09-01

In adult rodents, decreasing hippocampal neurogenesis experimentally using different approaches often impairs performance in hippocampus-dependent processes. Nonetheless, functional relevance of adult neurogenesis is far from being unraveled, and deficits so far described in animal models often lack reproducibility. One hypothesis is that such differences might be the consequence of the extent of the methodological specificity used to alter neurogenesis rather than the extent to which adult neurogenesis is altered. To address this, we focused on cranial irradiation, the most widely used technique to impair hippocampal neurogenesis and consequentially induce hippocampus-dependent behavioral deficits. To investigate the specificity of the technique, we thus exposed 4-5 months old female cyclin D2 knockout mice, a model lacking physiological levels of olfactory and hippocampal neurogenesis, to an X-ray dose of 10 Gy, reported to specifically affect transiently amplifying precursors. After a recovery period of 1.5 months, behavioral tests were performed and probed for locomotor activity, habituation, anxiety, and spatial learning and memory. Spatial learning in the Morris water maze was intact in all experimental groups. Although spatial memory retention assessed 24h following acquisition was also intact in all mice, irradiated wild type and cyclin D2 knockout mice displayed memory deficits one week after acquisition. In addition, we observed significant differences in tests addressing anxiety and locomotor activity dependent on the technique used to alter neurogenesis. Whereas irradiated mice were hyperactive regardless of their genotype, cyclin D2 knockout mice were hypoactive in most of the tests and displayed altered habituation. The present study emphasizes that different approaches aimed at decreasing adult hippocampal neurogenesis may result in distinct behavioral impairments related to locomotion and anxiety. In contrast, spatial long-term memory retention is

Increased Melanoma Growth and Metastasis Spreading in Mice Overexpressing Placenta Growth Factor

PubMed Central

Marcellini, Marcella; De Luca, Naomi; Riccioni, Teresa; Ciucci, Alessandro; Orecchia, Angela; Lacal, Pedro Miguel; Ruffini, Federica; Pesce, Maurizio; Cianfarani, Francesca; Zambruno, Giovanna; Orlandi, Augusto; Failla, Cristina Maria

2006-01-01

Placenta growth factor (PlGF), a member of the vascular endothelial growth factor family, plays an important role in adult pathological angiogenesis. To further investigate PlGF functions in tumor growth and metastasis formation, we used transgenic mice overexpressing PlGF in the skin under the control of the keratin 14 promoter. These animals showed a hypervascularized phenotype of the skin and increased levels of circulating PlGF with respect to their wild-type littermates. Transgenic mice and controls were inoculated intradermally with B16-BL6 melanoma cells. The tumor growth rate was fivefold increased in transgenic animals compared to wild-type mice, in the presence of a similar percentage of tumor necrotic tissue. Tumor vessel area was increased in transgenic mice as compared to controls. Augmented mobilization of endothelial and hematopoietic stem cells from the bone marrow was observed in transgenic animals, possibly contributing to tumor vascularization. The number and size of pulmonary metastases were significantly higher in transgenic mice compared to wild-type littermates. Finally, PlGF promoted tumor cell invasion of the extracellular matrix and increased the activity of selected matrix metalloproteinases. These findings indicate that PlGF, in addition to enhancing tumor angiogenesis and favoring tumor growth, may directly influence melanoma dissemination. PMID:16877362

Arsenic (+3 oxidation state) methyltransferase genotype affects steady-state distribution and clearance of arsenic in arsenate-treated mice

EPA Science Inventory

Arsenic (+3 oxidation state) methyltransferase (As3mt) catalyzes formation of mono-, di-, and tri-methylated metabolites of inorganic arsenic. Distribution and retention of arsenic were compared in adult female As3mt knockout mice and wild-type C57BL/6 mice using a regimen in whi...

Structural and functional cardiac cholinergic deficits in adult neurturin knockout mice.

PubMed

Mabe, Abigail M; Hoover, Donald B

2009-04-01

Previous work provided indirect evidence that the neurotrophic factor neurturin (NRTN) is required for normal cholinergic innervation of the heart. This study used nrtn knockout (KO) and wild-type (WT) mice to determine the effect of nrtn deletion on cardiac cholinergic innervation and function in the adult heart. Immunohistochemistry, confocal microscopy, and quantitative image analysis were used to directly evaluate intrinsic cardiac neuronal development. Atrial acetylcholine (ACh) levels were determined as an indirect index of cholinergic innervation. Cholinergic function was evaluated by measuring negative chronotropic responses to right vagal nerve stimulation in anaesthetized mice and responses of isolated atria to muscarinic agonists. KO hearts contained only 35% the normal number of cholinergic neurons, and the residual cholinergic neurons were 15% smaller than in WT. Cholinergic nerve density at the sinoatrial node was reduced by 87% in KOs, but noradrenergic nerve density was unaffected. Atrial ACh levels were substantially lower in KO mice (0.013 +/- 0.004 vs. 0.050 +/- 0.011 pmol/microg protein; P < 0.02) as expected from cholinergic neuron and nerve fibre deficits. Maximum bradycardia evoked by vagal stimulation was reduced in KO mice (38 +/- 6% vs. 69 +/- 3% decrease at 20 Hz; P < 0.001), and chronotropic responses took longer to develop and fade. In contrast to these deficits, isolated atria from KO mice had normal post-junctional sensitivity to carbachol and bethanechol. These findings demonstrate that NRTN is essential for normal cardiac cholinergic innervation and cholinergic control of heart rate. The presence of residual cardiac cholinergic neurons and vagal bradycardia in KO mice suggests that additional neurotrophic factors may influence this system.

Postprandial fatty acid uptake and adipocyte remodeling in angiotensin type 2 receptor-deficient mice fed a high-fat/high-fructose diet

PubMed Central

Noll, Christophe; Labbé, Sébastien M.; Pinard, Sandra; Shum, Michael; Bilodeau, Lyne; Chouinard, Lucie; Phoenix, Serge; Lecomte, Roger; Carpentier, André C.; Gallo-Payet, Nicole

2016-01-01

ABSTRACT The role of the angiotensin type-2 receptor in adipose physiology remains controversial. The aim of the present study was to demonstrate whether genetic angiotensin type-2 receptor-deficiency prevents or worsens metabolic and adipose tissue morphometric changes observed following a 6-week high-fat/high-fructose diet with injection of a small dose of streptozotocin. We compared tissue uptake of nonesterified fatty acid and dietary fatty acid in wild-type and angiotensin type-2 receptor-deficient mice by using the radiotracer 14(R,S)-[18F]-fluoro-6-thia-heptadecanoic acid in mice fed a standard or high-fat diet. Postprandial fatty acid uptake in the heart, liver, skeletal muscle, kidney and adipose tissue was increased in wild-type mice after a high-fat diet and in angiotensin type-2 receptor-deficient mice on both standard and high-fat diets. Compared to the wild-type mice, angiotensin type-2 receptor-deficient mice had a lower body weight, an increase in fasting blood glucose and a decrease in plasma insulin and leptin levels. Mice fed a high-fat diet exhibited increased adipocyte size that was prevented by angiotensin type-2 receptor-deficiency. Angiotensin type-2 receptor-deficiency abolished the early hypertrophic adipocyte remodeling induced by a high-fat diet. The small size of adipocytes in the angiotensin type-2 receptor-deficient mice reflects their inability to store lipids and explains the increase in fatty acid uptake in non-adipose tissues. In conclusion, a genetic deletion of the angiotensin type-2 receptor is associated with metabolic dysfunction of white adipose depots, and indicates that adipocyte remodeling occurs before the onset of insulin resistance in the high-fat fed mouse model. PMID:27144096

Continuous in vivo infusion of interferon-gamma (IFN-gamma) enhances engraftment of syngeneic wild-type cells in Fanca-/- and Fancg-/- mice.

PubMed

Si, Yue; Ciccone, Samantha; Yang, Feng-Chun; Yuan, Jin; Zeng, Daisy; Chen, Shi; van de Vrugt, Henri J; Critser, John; Arwert, Fre; Haneline, Laura S; Clapp, D Wade

2006-12-15

Fanconi anemia (FA) is a heterogeneous genetic disorder characterized by bone marrow (BM) failure and cancer susceptibility. Identification of the cDNAs of FA complementation types allows the potential of using gene transfer technology to introduce functional cDNAs as transgenes into autologous stem cells and provide a cure for the BM failure in FA patients. However, strategies to enhance the mobilization, transduction, and engraftment of exogenous stem cells are required to optimize efficacy prior to widespread clinical use. Hypersensitivity of Fancc-/- cells to interferon-gamma (IFN-gamma), a nongenotoxic immune-regulatory cytokine, enhances engraftment of syngeneic wild-type (WT) cells in Fancc-/- mice. However, whether this phenotype is of broad relevance in other FA complementation groups is unresolved. Here we show that primitive and mature myeloid progenitors in Fanca-/- and Fancg-/- mice are hypersensitive to IFN-gamma and that in vivo infusion of IFN-gamma at clinically relevant concentrations was sufficient to allow consistent long-term engraftment of isogenic WT repopulating stem cells. Given that FANCA, FANCC, and FANCG complementation groups account for more than 90% of all FA patients, these data provide evidence that IFN-gamma conditioning may be a useful nongenotoxic strategy for myelopreparation in FA patients.

Reduced infarct size in neuroglobin-null mice after experimental stroke in vivo

PubMed Central

2012-01-01

Background Neuroglobin is considered to be a novel important pharmacological target in combating stroke and neurodegenerative disorders, although the mechanism by which this protection is accomplished remains an enigma. We hypothesized that if neuroglobin is directly involved in neuroprotection, then permanent cerebral ischemia would lead to larger infarct volumes in neuroglobin-null mice than in wild-type mice. Methods Using neuroglobin-null mice, we estimated the infarct volume 24 hours after permanent middle cerebral artery occlusion using Cavalieri’s Principle, and compared the infarct volume in neuroglobin-null and wild-type mice. Neuroglobin antibody staining was used to examine neuroglobin expression in the infarct area of wild-type mice. Results Infarct volumes 24 hours after permanent middle cerebral artery occlusion were significantly smaller in neuroglobin-null mice than in wild-types (p < 0.01). Neuroglobin immunostaining of the penumbra area revealed no visible up-regulation of neuroglobin protein in ischemic wild-type mice when compared to uninjured wild-type mice. In uninjured wild-type mice, neuroglobin protein was seen throughout cortical layer II and sparsely in layer V. In contrast, no neuroglobin-immunoreactive neurons were observed in the aforementioned layers of the ischemia injured cortical area, or in the surrounding penumbra of ischemic wild-type mice. This suggests no selective sparing of neuroglobin expressing neurons in ischemia. Conclusions Neuroglobin-deficiency resulted in reduced tissue infarction, suggesting that, at least at endogenous expression levels, neuroglobin in itself is non-protective against ischemic injury. PMID:22901501

Wild-type offspring of heterozygous prolactin receptor-null female mice have maladaptive β-cell responses during pregnancy.

PubMed

Huang, Carol

2013-03-01

Abstract  β-Cell mass increases during pregnancy in adaptation to the insulin resistance of pregnancy. This increase is accompanied by an increase in β-cell proliferation, a process that requires intact prolactin receptor (Prlr) signalling. Previously, it was found that during pregnancy, heterozygous prolactin receptor-null (Prlr(+/-)) mice had lower number of β-cells, lower serum insulin and higher blood glucose levels than wild-type (Prlr(+/+)) mice. An unexpected observation was that the glucose homeostasis of the experimental mouse depends on the genotype of her mother, such that within the Prlr(+/+) group, the Prlr(+/+) offspring derived from Prlr(+/+) mothers (Prlr(+/+(+/+))) had higher β-cell mass and lower blood glucose than those derived from Prlr(+/-) mothers (Prlr(+/+(+/-))). Pathways that are known to regulate β-cell proliferation during pregnancy include insulin receptor substrate-2, Akt, menin, the serotonin synthetic enzyme tryptophan hydroxylase-1, Forkhead box M1 and Forkhead box D3. The aim of the present study was to determine whether dysregulation in these signalling molecules in the islets could explain the maternal effect on the phenotype of the offspring. It was found that the pregnancy-induced increases in insulin receptor substrate-2 and Akt expression in the islets were attenuated in the Prlr(+/+(+/-)) mice in comparison to the Prlr(+/+(+/+)) mice. The expression of Forkhead box D3, which plays a permissive role for β-cell proliferation during pregnancy, was also lower in the Prlr(+/+(+/-)) mice. In contrast, the pregnancy-induced increases in phospho-Jak2, tryptophan hydroxylase-1 and FoxM1, as well as the pregnancy-associated reduction in menin expression, were comparable between the two groups. There was also no difference in expression levels of genes that regulate insulin synthesis and secretion (i.e. glucose transporter 2, glucokinase and pancreatic and duodenal homeobox-1) between these two groups. Taken together, these

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.

A Novel 1,4-Dihydropyridine Derivative Improves Spatial Learning and Memory and Modifies Brain Protein Expression in Wild Type and Transgenic APPSweDI Mice.

PubMed

Jansone, Baiba; Kadish, Inga; van Groen, Thomas; Beitnere, Ulrika; Moore, Doyle Ray; Plotniece, Aiva; Pajuste, Karlis; Klusa, Vija

2015-01-01

Ca2+ blockers, particularly those capable of crossing the blood-brain barrier (BBB), have been suggested as a possible treatment or disease modifying agents for neurodegenerative disorders, e.g., Alzheimer's disease. The present study investigated the effects of a novel 4-(N-dodecyl) pyridinium group-containing 1,4-dihydropyridine derivative (AP-12) on cognition and synaptic protein expression in the brain. Treatment of AP-12 was investigated in wild type C57BL/6J mice and transgenic Alzheimer's disease model mice (Tg APPSweDI) using behavioral tests and immunohistochemistry, as well as mass spectrometry to assess the blood-brain barrier (BBB) penetration. The data demonstrated the ability of AP-12 to cross the BBB, improve spatial learning and memory in both mice strains, induce anxiolytic action in transgenic mice, and increase expression of hippocampal and cortical proteins (GAD67, Homer-1) related to synaptic plasticity. The compound AP-12 can be seen as a prototype molecule for use in the design of novel drugs useful to halt progression of clinical symptoms (more specifically, anxiety and decline in memory) of neurodegenerative diseases, particularly Alzheimer's disease.

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.

Effect of Anti-Sclerostin Therapy and Osteogenesis Imperfecta on Tissue-level Properties in Growing and Adult Mice While Controlling for Tissue Age

PubMed Central

Sinder, Benjamin P.; Lloyd, William R.; Salemi, Joseph D.; Marini, Joan C.; Caird, Michelle S.; Morris, Michael D.; Kozloff, Kenneth M.

2016-01-01

Bone composition and biomechanics at the tissue-level are important contributors to whole bone strength. Sclerostin antibody (Scl-Ab) is a candidate anabolic therapy for the treatment of osteoporosis that increases bone formation, bone mass, and bone strength in animal studies, but its effect on bone quality at the tissue-level has received little attention. Pre-clinical studies of Scl-Ab have recently expanded to include diseases with altered collagen and material properties such as Osteogenesis Imperfecta (OI). The purpose of this study was to investigate the role of Scl-Ab on bone quality by determining bone material composition and tissue-level mechanical properties in normal wild type (WT) tissue, as well as mice with a typical OI Gly→Cys mutation (Brtl/+) in type I collagen. Rapidly growing (3-week-old) and adult (6-month-old) WT and Brtl/+ mice were treated for 5 weeks with Scl-Ab. Fluorescent guided tissue-level bone composition analysis (Raman spectroscopy) and biomechanical testing (nanoindentation) were performed at multiple tissue ages. Scl-Ab increased mineral to matrix in adult WT and Brtl/+ at tissue ages of 2–4wks. However, no treatment related changes were observed in mineral to matrix levels at mid-cortex, and elastic modulus was not altered by Scl-Ab at any tissue age. Increased mineral-to-matrix was phenotypically observed in adult Brtl/+ OI mice (at tissue ages >3wk) and rapidly growing Brtl/+ (at tissue ages > 4wk) mice compared to WT. At identical tissue ages defined by fluorescent labels adult mice had generally lower mineral to matrix ratios and a greater elastic modulus than rapidly growing mice, demonstrating that bone matrix quality can be influenced by animal age and tissue age alike. In summary, these data suggest that Scl-Ab alters the matrix chemistry of newly formed bone while not affecting the elastic modulus, induces similar changes between Brtl/+ and WT mice, and provides new insight into the interaction between tissue age

Effect of anti-sclerostin therapy and osteogenesis imperfecta on tissue-level properties in growing and adult mice while controlling for tissue age.

PubMed

Sinder, Benjamin P; Lloyd, William R; Salemi, Joseph D; Marini, Joan C; Caird, Michelle S; Morris, Michael D; Kozloff, Kenneth M

2016-03-01

Bone composition and biomechanics at the tissue-level are important contributors to whole bone strength. Sclerostin antibody (Scl-Ab) is a candidate anabolic therapy for the treatment of osteoporosis that increases bone formation, bone mass, and bone strength in animal studies, but its effect on bone quality at the tissue-level has received little attention. Pre-clinical studies of Scl-Ab have recently expanded to include diseases with altered collagen and material properties such as osteogenesis imperfecta (OI). The purpose of this study was to investigate the role of Scl-Ab on bone quality by determining bone material composition and tissue-level mechanical properties in normal wild type (WT) tissue, as well as mice with a typical OI Gly➔Cys mutation (Brtl/+) in type I collagen. Rapidly growing (3-week-old) and adult (6-month-old) WT and Brtl/+ mice were treated for 5weeks with Scl-Ab. Fluorescent guided tissue-level bone composition analysis (Raman spectroscopy) and biomechanical testing (nanoindentation) were performed at multiple tissue ages. Scl-Ab increased mineral to matrix in adult WT and Brtl/+ at tissue ages of 2-4wks. However, no treatment related changes were observed in mineral to matrix levels at mid-cortex, and elastic modulus was not altered by Scl-Ab at any tissue age. Increased mineral-to-matrix was phenotypically observed in adult Brtl/+ OI mice (at tissue ages>3wks) and rapidly growing Brtl/+ (at tissue ages>4wks) mice compared to WT. At identical tissue ages defined by fluorescent labels, adult mice had generally lower mineral to matrix ratios and a greater elastic modulus than rapidly growing mice, demonstrating that bone matrix quality can be influenced by animal age and tissue age alike. In summary, these data suggest that Scl-Ab alters the matrix chemistry of newly formed bone while not affecting the elastic modulus, induces similar changes between Brtl/+ and WT mice, and provides new insight into the interaction between tissue age and

Analysis of the Effect of Estrogen/Androgen Perturbation on Penile Development in Transgenic and Diethylstilbestrol-Treated Mice

PubMed Central

BLASCHKO, SARAH D.; MAHAWONG, PHITSANU; FERRETTI, MAX; CUNHA, TRISTAN J.; SINCLAIR, ADRIANE; WANG, HONG; SCHLOMER, BRUCE J.; RISBRIDGER, GAIL; BASKIN, LAURENCE S.; CUNHA, GERALD R.

2013-01-01

Because both androgens and estrogens have been implicated in penile morphogenesis, we evaluated penile morphology in transgenic mice with known imbalance of androgen and estrogen signaling using scanning electron microscopy (SEM), histology, and immunohistochemistry of androgen and estrogen receptors α/β. Penises of adult wild-type, estrogen receptor-α knockout (αERKO), estrogen receptor-β knockout (βERKO), aromatase knockout (Arom-KO), and aromatase overexpression (Arom+) mice were evaluated, as well as adult mice treated with diethylstilbestrol (DES) from birth to day 10. Adult penises were examined because the adult pattern is the endpoint of development. The urethral orifice is formed by fusion of the MUMP (male urogenital mating protuberance) with the MUMP ridge, which consists of several processes fused to each other and to the MUMP. Similarly, the internal prepuce is completed ventrally by fusion of a ventral cleft. In adult murine penises the stromal processes that form the MUMP ridge are separated from their neighbors by clefts. αERKO, βERKO, and Arom-KO mice have penises with a MUMP ridge clefting pattern similar to that of wild-type mice. In contrast, Arom+ mice and neonatally DES-treated mice exhibit profound malformations of the MUMP, MUMP ridge clefting pattern, and internal prepuce. Abnormalities observed in Arom+ and neonatally DES-treated mice correlate with the expression of estrogen receptor-beta (ERβ) in the affected structures. This study demonstrates that formation of the urethal orifice and internal prepuce is due to fusion of separate epithelial-surfaced mesenchymal elements, a process dependent upon both androgen and estrogen signaling, in which ERβ signaling is strongly implicated. PMID:23653160

Three Herpes Simplex Virus Type 1 Latency-Associated Transcript Mutants with Distinct and Asymmetric Effects on Virulence in Mice Compared with Rabbits

PubMed Central

Perng, Guey-Chuen; Esmaili, Daniel; Slanina, Susan M.; Yukht, Ada; Ghiasi, Homayon; Osorio, Nelson; Mott, Kevin R.; Maguen, Barak; Jin, Ling; Nesburn, Anthony B.; Wechsler, Steven L.

2001-01-01

Herpes simplex virus type 1 latency-associated transcript (LAT)-null mutants have decreased reactivation but normal virulence in rabbits and mice. We report here on dLAT1.5, a mutant with LAT nucleotides 76 to 1667 deleted. Following ocular infection of rabbits, dLAT1.5 reactivated at a lower rate than its wild-type parent McKrae (6.1 versus 11.8%; P = 0.0025 [chi-square test]). Reactivation was restored in the marker-rescued virus dLAT1.5R (12.6%; P = 0.53 versus wild type), confirming the importance of the deleted region in spontaneous reactivation. Compared with wild-type or marker-rescued virus, dLAT1.5 had similar or slightly reduced virulence in rabbits (based on survival following ocular infection). In contrast, in mice, dLAT1.5 had increased virulence (P < 0.0001). Thus, deletion of LAT nucleotides 76 to 1667 increased viral virulence in mice but not in rabbits. In contrast, we also report here that LAT2.9A, a LAT mutant that we previously reported to have increased virulence in rabbits (G. C. Perng, S. M. Slanina, A. Yuhkt, B. S. Drolet, W. J. Keleher, H. Ghiasi, A. B. Nesburn, and S. L. Wechsler, J. Virol. 73:920–929, 1999), had decreased virulence in mice (P = 0.03). In addition, we also found that dLAT371, a LAT mutant that we previously reported to have wild-type virulence in rabbits (G. C. Perng, S. M. Slanina, H. Ghiasi, A. B. Nesburn, and S. L. Wechsler, J. Virol. 70:2014–2018, 1996), had decreased virulence in mice (P < 0.05). Thus, these three mutants, each of which encodes a different LAT RNA, have different virulence phenotypes. dLAT1.5 had wild-type virulence in rabbits but increased virulence in mice. In contrast, LAT2.9A had increased virulence in rabbits but decreased virulence in mice, and dLAT371 had wild-type virulence in rabbits but decreased virulence in mice. Taken together, these results suggest that (i) the 5′ end of LAT and/or a gene that overlaps part of this region is involved in viral virulence, (ii) this virulence appears

Transcriptome and proteome analysis of Salmonella enterica serovar Typhimurium systemic infection of wild type and immune-deficient mice

PubMed Central

Oshota, Olusegun; Fookes, Maria; Schreiber, Fernanda; Chaudhuri, Roy R.; Yu, Lu; Clare, Simon; Choudhary, Jyoti; Thomson, Nicholas R.; Lio, Pietro

2017-01-01

Salmonella enterica are a threat to public health. Current vaccines are not fully effective. The ability to grow in infected tissues within phagocytes is required for S. enterica virulence in systemic disease. As the infection progresses the bacteria are exposed to a complex host immune response. Consequently, in order to continue growing in the tissues, S. enterica requires the coordinated regulation of fitness genes. Bacterial gene regulation has so far been investigated largely using exposure to artificial environmental conditions or to in vitro cultured cells, and little information is available on how S. enterica adapts in vivo to sustain cell division and survival. We have studied the transcriptome, proteome and metabolic flux of Salmonella, and the transcriptome of the host during infection of wild type C57BL/6 and immune-deficient gp91-/-phox mice. Our analyses advance the understanding of how S. enterica and the host behaves during infection to a more sophisticated level than has previously been reported. PMID:28796780

Exogenous PTHrP Repairs the Damaged Fracture Healing of PTHrP+/− Mice and Accelerates Fracture Healing of Wild Mice

PubMed Central

Wang, Yinhe; Fang, Xin; Wang, Chun; Ding, Congzhu; Lin, Hua; Liu, Anlong; Wang, Lei; Cao, Yang

2017-01-01

Bone fracture healing is a complicated physiological regenerative process initiated in response to injury and is similar to bone development. To demonstrate whether an exogenous supply of parathyroid hormone–related protein (PTHrP) helps in bone fracture healing, closed mid-diaphyseal femur fractures were created and stabilized with intramedullary pins in eight-week-old wild-type (WT) PTHrP+/+ and PTHrP+/− mice. After administering PTHrP for two weeks, callus tissue properties were analyzed at one, two, and four weeks post-fracture (PF) by various methods. Bone formation–related genes and protein expression levels were evaluated by real-time reverse transcriptase–polymerase chain reaction and Western blots. At two weeks PF, mineral density of callus, bony callus areas, mRNA levels of alkaline phosphatase (ALP), type I collagen, Runt-related transcription factor 2 (Runx-2), and protein levels of Runx-2 and insulin-like growth factor-1 decreased in PTHrP+/− mice compared with WT mice. At four weeks PF, total collagen-positive bony callus areas, osteoblast number, ALP-positive areas, and type I collagen-positive areas all decreased in PTHrP+/− mice. At both two and four weeks PF, tartrate-resistant acid phosphatase–positive osteoclast number and surface decreased a little in PTHrP+/− mice. The study indicates that exogenous PTHrP provided by subcutaneous injection could redress impaired bone fracture healing, leading to mutation of activated PTHrP by influencing callus areas, endochondral bone formation, osteoblastic bone formation, and bone turnover. PMID:28178186

Voluntary scheduled exercise alters diurnal rhythms of behaviour, physiology and gene expression in wild-type and vasoactive intestinal peptide-deficient mice

PubMed Central

Schroeder, Analyne M; Truong, Danny; Loh, Dawn H; Jordan, Maria C; Roos, Kenneth P; Colwell, Christopher S

2012-01-01

The circadian system co-ordinates the temporal patterning of behaviour and many underlying biological processes. In some cases, the regulated outputs of the circadian system, such as activity, may be able to feed back to alter core clock processes. In our studies, we used four wheel-access conditions (no access; free access; early night; and late night) to manipulate the duration and timing of activity while under the influence of a light–dark cycle. In wild-type mice, scheduled wheel access was able to increase ambulatory activity, inducing a level of exercise driven at various phases of the light–dark cycle. Scheduled exercise also manipulated the magnitude and phasing of the circadian-regulated outputs of heart rate and body temperature. At a molecular level, the phasing and amplitude of PER2::LUCIFERASE (PER2::LUC) expression rhythms in the SCN and peripheral tissues of Per2::Luc knockin mice were altered by scheduled exercise. We then tested whether scheduled wheel access could improve deficits observed in vasointestinal polypeptide-deficient mice under the influence of a light–dark cycle. We found that scheduled wheel access during the late night improved many of the behavioural, physiological and molecular deficits previously described in vasointestinal polypeptide-deficient mice. Our results raise the possibility that scheduled exercise could be used as a tool to modulate daily rhythms and, when applied, may counteract some of the negative impacts of ageing and disease on the circadian system. PMID:22988135

IDENTIFICATION OF NOVEL TOXICITY-ASSOCIATED METABOLITES BY METABOLOMICS AND MASS ISOTOPOMER ANALYSIS OF ACETAMINOPHEN METABOLISM IN WILD-TYPE AND CYP2E1-NULL MICE

PubMed Central

Chen, Chi; Krausz, Kristopher W.; Idle, Jeffrey R.; Gonzalez, Frank J.

2008-01-01

CYP2E1 is recognized as the most important enzyme for initiation of acetaminophen (APAP)-induced toxicity. In this study, the resistance of Cyp2e1-null mice to APAP treatment was confirmed by comparing serum aminotransferase activities and blood urea nitrogen levels in wild-type and Cyp2e1-null mice. However, unexpectedly, profiling of major known APAP metabolites in urine and serum revealed that the contribution of CYP2E1 to APAP metabolism decreased with increasing APAP doses administered. Measurement of hepatic glutathione and hydrogen peroxide levels exposed the importance of oxidative stress in determining the consequence of APAP overdose. Subsequent metabolomic analysis was capable of constructing a principal components analysis (PCA) model that delineated a relationship between urinary metabolomes and the responses to APAP treatment. Urinary ions high in wild-type mice treated with 400 mg/kg APAP were elucidated as 3-methoxy-APAP glucuronide (VII) and three novel APAP metabolites, including S-(5-acetylamino-2-hydroxyphenyl)mercaptopyruvic acid (VI, formed by a Cys-APAP transamination reaction in kidney), 3,3′-biacetaminophen (VIII, an APAP dimer) and a benzothiazine compound (IX, originated from deacetylated APAP), through mass isotopomer analysis, accurate mass measurement, tandem MS fragmentation, in vitro reactions and chemical treatments. Dose-, time- and genotype-dependent appearance of these minor APAP metabolites implied their association with the APAP-induced toxicity and potential biomarker application. Overall, the oxidative stress elicited by CYP2E1-mediated APAP metabolism might significantly contribute to APAP-induced toxicity. The combination of genetically-modified animal models, mass isotopomer analysis and metabolomics provides a powerful and efficient technical platform to characterize APAP-induced toxicity through identifying novel biomarkers and unravelling novel mechanisms. PMID:18093979

Potential Role for ADAM15 in Pathological Neovascularization in Mice

PubMed Central

Horiuchi, Keisuke; Weskamp, Gisela; Lum, Lawrence; Hammes, Hans-Peter; Cai, Hui; Brodie, Thomas A.; Ludwig, Thomas; Chiusaroli, Riccardo; Baron, Roland; Preissner, Klaus T.; Manova, Katia; Blobel, Carl P.

2003-01-01

ADAM15 (named for a disintegrin and metalloprotease 15, metargidin) is a membrane-anchored glycoprotein that has been implicated in cell-cell or cell-matrix interactions and in the proteolysis of molecules on the cell surface or extracellular matrix. To characterize the potential roles of ADAM15 during development and in adult mice, we analyzed its expression pattern by mRNA in situ hybridization and generated mice carrying a targeted deletion of ADAM15 (adam15−/− mice). A high level of expression of ADAM15 was found in vascular cells, the endocardium, hypertrophic cells in developing bone, and specific areas of the hippocampus and cerebellum. However, despite the pronounced expression of ADAM15 in these tissues, no major developmental defects or pathological phenotypes were evident in adam15−/− mice. The elevated levels of ADAM15 in endothelial cells prompted an evaluation of its role in neovascularization. In a mouse model for retinopathy of prematurity, adam15−/− mice had a major reduction in neovascularization compared to wild-type controls. Furthermore, the size of tumors resulting from implanted B16F0 mouse melanoma cells was significantly smaller in adam15−/− mice than in wild-type controls. Since ADAM15 does not appear to be required for developmental angiogenesis or for adult homeostasis, it may represent a novel target for the design of inhibitors of pathological neovascularization. PMID:12897135

Recombination and mutation of class II histocompatibility genes in wild mice.

PubMed

Wakeland, E K; Darby, B R

1983-12-01

We have compared the tryptic peptide fingerprints of the A alpha, A beta, E alpha, and E beta subunits encoded by four wild-derived H-2 complexes expressing A molecules closely related to Ak. The A molecules encoded by these Ak-related mice have A alpha and A beta subunits that differ from A alpha k and A beta k by less than 10% of their tryptic peptides. Comparisons among the four wild-derived A molecules suggested that these contemporary A alpha and A beta alleles arose by sequential mutational events from common ancestor A alpha and A beta alleles. These results suggest that A alpha and A beta may co-evolve as an A beta A alpha gene duplex in wild mice. Tryptic peptide fingerprint comparisons of the E beta gene linked to these Ak-related A beta A alpha gene duplexes indicate that two encode E beta d-like subunits, whereas another encodes an E beta s-like subunit. These results strongly suggest that the A beta A alpha duplex and E beta recombine in wild mouse populations. The significantly different evolutionary patterns exhibited by the class II genes encoding A vs E molecules are discussed.

Antibody titers against vaccine and contemporary wild poliovirus type 1 in children immunized with IPV+OPV and young adults immunized with OPV.

PubMed

Lukashev, Alexander N; Yarmolskaya, Maria S; Shumilina, Elena Yu; Sychev, Daniil A; Kozlovskaya, Liubov I

2016-02-02

In 2010, a type 1 poliovirus outbreak in Congo with 445 lethal cases was caused by a virus that was neutralized by sera of German adults vaccinated with inactivated polio vaccine with a reduced efficiency. This seroprevalence study was done in two cohorts immunized with other vaccination schedules. Russian children aged 3-6 years immunized with a combination of inactivated and live polio vaccines were reasonably well protected against any wild type poliovirus 1, including the Congolese isolate. Adults aged 20-29 years immunized only with live vaccine were apparently protected against the vaccine strain (92% seropositive), but only 50% had detectable antibodies against the Congo-2010 isolate. Both waning immunity and serological divergence of the Congolese virus could contribute to this result. Copyright © 2015 Elsevier B.V. All rights reserved.

The lack of RNA-dependent protein kinase enhances susceptibility of mice to genital herpes simplex virus type 2 infection

PubMed Central

Carr, Daniel J J; Wuest, Todd; Tomanek, Lisa; Silverman, Robert H; Williams, Bryan R G

2006-01-01

Mice deficient in RNA-dependent protein kinase (PKR–/–) or deficient in PKR and a functional 2′,5′-oligoadenylate synthetase (OAS) pathway (PKR/RL–/–) are more susceptible to genital herpes simplex virus type 2 (HSV-2) infection than wild-type mice or mice that are deficient only in a functional OAS pathway (RL–/–) as measured by survival over 30 days. The increase in susceptibility correlated with an increase in virus titre recovered from vaginal tissue or brainstem of infected mice during acute infection. There was also an increase in CD45+ cells and CD8+ T cells residing in the central nervous system of HSV-2-infected PKR/RL–/– mice in comparison with RL–/– or wild-type control animals. In contrast, there was a reduction in the HSV-specific CD8+ T cells within the draining lymph node of the PKR/RL–/– mice. Collectively, activation of PKR, but not of OAS, contributes significantly to the local control and spread of HSV-2 following genital infection. PMID:16895559

Defining wild-type life span in Caenorhabditis elegans.

PubMed

Gems, D; Riddle, D L

2000-05-01

The nematode Caenorhabditis elegans reproduces predominantly as a self-fertilizing hermaphrodite, and this drives laboratory populations to be homozygous at all genetic loci. Passaging of stocks can lead to fixation of spontaneous mutations, especially when the latter do not result in a selective disadvantage under laboratory conditions. Life span may be such a trait, since a comparison of six wild-type N2 lines derived from a common ancestor (but maintained separately in several laboratories) revealed four variants with median adult life spans ranging from 12.0 +/- 0.8 to 17.0 +/- 0.6 days at 20 degrees C. Fertility was also reduced in the two shortest-lived strains. We determined which life span most closely corresponds to that of the authentic wild type by two means. Firstly, N2 hermaphrodites were compared with seven C. elegans wild isolates. The latter were found to resemble only the longest-lived N2 strain. Comparison of male life spans of six lines also revealed additional strain variation. Secondly, life spans of F1 progeny issuing from crosses between N2 variants showed that short life spans were recessive, indicating that they result from loss-of-function mutations. We infer that the longest-lived N2 variant best resembles the original N2 isolate. This is the N2 male stock currently distributed by the Caenorhabditis Genetics Center.

Pituitary-adrenal responses to oxotremorine and acute stress in male and female M1 muscarinic receptor knockout mice: comparisons to M2 muscarinic receptor knockout mice.

PubMed

Rhodes, M E; Rubin, R T; McKlveen, J M; Karwoski, T E; Fulton, B A; Czambel, R K

2008-05-01

Both within the brain and in the periphery, M(1) muscarinic receptors function primarily as postsynaptic receptors and M(2) muscarinic receptors function primarily as presynaptic autoreceptors. In addition to classical parasympathetic effectors, cholinergic stimulation of central muscarinic receptors influences the release of adrenocorticotrophic hormone (ACTH) and corticosterone. We previously reported that oxotremorine administration to male and female M(2) receptor knockout and wild-type mice increased ACTH to a significantly greater degree in knockout males compared to all other groups, and that M(2) knockout mice of both sexes were significantly more responsive to the mild stress of saline injection than were wild-type mice. These results accord with the primary function of M(2) receptors as presynaptic autoreceptors. In the present study, we explored the role of the M(1) receptor in pituitary-adrenal responses to oxotremorine and saline in male and female M(1) knockout and wild-type mice. Because these mice responded differently to the mild stress of saline injection than did the M(2) knockout and wild-type mice, we also determined hormone responses to restraint stress in both M(1) and M(2) knockout and wild-type mice. Male and female M(1) knockout and wild-type mice were equally unresponsive to the stress of saline injection. Oxotremorine increased both ACTH and corticosterone in M(1) wild-type mice to a significantly greater degree than in knockout mice. In both M(1) knockout and wild-type animals, ACTH responses were greater in males compared to females, and corticosterone responses were greater in females compared to males. Hormone responses to restraint stress were increased in M(2) knockout mice and decreased in M(1) knockout mice compared to their wild-type counterparts. These findings suggest that M(1) and M(2) muscarinic receptor subtypes differentially influence male and female pituitary-adrenal responses to cholinergic stimulation and stress. The

Production of ultrasonic vocalizations by Peromyscus mice in the wild

PubMed Central

Kalcounis-Rueppell, Matina C; Metheny, Jackie D; Vonhof, Maarten J

2006-01-01

Background There has been considerable research on rodent ultrasound in the laboratory and these sounds have been well quantified and characterized. Despite the value of research on ultrasound produced by mice in the lab, it is unclear if, and when, these sounds are produced in the wild, and how they function in natural habitats. Results We have made the first recordings of ultrasonic vocalizations produced by two free-living species of mice in the genus Peromyscus (P. californicus and P. boylii) on long term study grids in California. Over 6 nights, we recorded 65 unique ultrasonic vocalization phrases from Peromyscus. The ultrasonic vocalizations we recorded represent 7 different motifs. Within each motif, there was considerable variation in the acoustic characteristics suggesting individual and contextual variation in the production of ultrasound by these species. Conclusion The discovery of the production of ultrasonic vocalizations by Peromyscus in the wild highlights an underappreciated component in the behavior of these model organisms. The ability to examine the production of ultrasonic vocalizations in the wild offers excellent opportunities to test hypotheses regarding the function of ultrasound produced by rodents in a natural context. PMID:16507093

Chronic activation of wild-type epidermal growth factor receptor and loss of Cdkn2a cause mouse glioblastoma formation.

PubMed

Acquaviva, Jaime; Jun, Hyun Jung; Lessard, Julie; Ruiz, Rolando; Zhu, Haihao; Donovan, Melissa; Woolfenden, Steve; Boskovitz, Abraham; Raval, Ami; Bronson, Roderick T; Pfannl, Rolf; Whittaker, Charles A; Housman, David E; Charest, Al

2011-12-01

Glioblastoma multiforme (GBM) is characterized by overexpression of epidermal growth factor receptor (EGFR) and loss of the tumor suppressors Ink4a/Arf. Efforts at modeling GBM using wild-type EGFR in mice have proven unsuccessful. Here, we present a unique mouse model of wild-type EGFR-driven gliomagenesis. We used a combination of somatic conditional overexpression and ligand-mediated chronic activation of EGFR in cooperation with Ink4a/Arf loss in the central nervous system of adult mice to generate tumors with the histopathologic and molecular characteristics of human GBMs. Sustained, ligand-mediated activation of EGFR was necessary for gliomagenesis, functionally substantiating the clinical observation that EGFR-positive GBMs from patients express EGFR ligands. To gain a better understanding of the clinically disappointing EGFR-targeted therapies for GBM, we investigated the molecular responses to EGFR tyrosine kinase inhibitor (TKI) treatment in this model. Gefitinib treatment of primary GBM cells resulted in a robust apoptotic response, partially conveyed by mitogen-activated protein kinase (MAPK) signaling attenuation and accompanied by BIM(EL) expression. In human GBMs, loss-of-function mutations in the tumor suppressor PTEN are a common occurrence. Elimination of PTEN expression in GBM cells posttumor formation did not confer resistance to TKI treatment, showing that PTEN status in our model is not predictive. Together, these findings offer important mechanistic insights into the genetic determinants of EGFR gliomagenesis and sensitivity to TKIs and provide a robust discovery platform to better understand the molecular events that are associated with predictive markers of TKI therapy.

Effects of ascorbic acid on carcinogenicity and acute toxicity of nickel subsulfide, and on tumor transplants growth in gulonolactone oxidase knock-out mice and wild-type C57BL mice

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

Kasprzak, Kazimierz S.; Diwan, Bhalchandra A.; Kaczmarek, Monika Z.

2011-11-15

The aim of this study was to test a hypothesis that ascorbate depletion could enhance carcinogenicity and acute toxicity of nickel. Homozygous L-gulono- < gamma > -lactone oxidase gene knock-out mice (Gulo-/- mice) unable to produce ascorbate and wild-type C57BL mice (WT mice) were injected intramuscularly with carcinogenic nickel subsulfide (Ni{sub 3}S{sub 2}), and observed for the development of injection site tumors for 57 weeks. Small pieces of one of the induced tumors were transplanted subcutaneously into separate groups of Gulo-/- and WT mice and the growth of these tumors was measured for up to 3 months. The two strainsmore » of mice differed significantly with regard to (1) Ni{sub 3}S{sub 2} carcinogenesis: Gulo-/- mice were 40% more susceptible than WT mice; and (2) transplanted tumors development: Gulo-/- mice were more receptive to tumor growth than WT mice, but only in terms of a much shorter tumor latency; later in the exponential phase of growth, the growth rates were the same. And, with adequate ascorbate supplementation, the two strains were equally susceptible to acute toxicity of Ni{sub 3}S{sub 2}. Statistically significant effects of dietary ascorbate dosing levels were the following: (1) reduction in ascorbate supplementation increased acute toxicity of Ni{sub 3}S{sub 2} in Gulo-/- mice; (2) ascorbate supplementation extended the latency of transplanted tumors in WT mice. In conclusion, the lack of endogenous ascorbate synthesis makes Gulo-/- mice more susceptible to Ni{sub 3}S{sub 2} carcinogenesis. Dietary ascorbate tends to attenuate acute toxicity of Ni{sub 3}S{sub 2} and to extend the latency of transplanted tumors. The latter effects may be of practical importance to humans and thus deserve further studies. -- Highlights: Black-Right-Pointing-Pointer Ascorbate depletion enhances carcinogenicity and acute toxicity of nickel. Black-Right-Pointing-Pointer Gulo-/- mice unable to synthesize ascorbate were used in this study. Black

Expression of Wild-Type Rp1 Protein in Rp1 Knock-in Mice Rescues the Retinal Degeneration Phenotype

PubMed Central

Liu, Qin; Collin, Rob W. J.; Cremers, Frans P. M.; den Hollander, Anneke I.; van den Born, L. Ingeborgh; Pierce, Eric A.

2012-01-01

Mutations in the retinitis pigmentosa 1 (RP1) gene are a common cause of autosomal dominant retinitis pigmentosa (adRP), and have also been found to cause autosomal recessive RP (arRP) in a few families. The 33 dominant mutations and 6 recessive RP1 mutations identified to date are all nonsense or frameshift mutations, and almost exclusively (38 out of 39) are located in the 4th and final exon of RP1. To better understand the underlying disease mechanisms of and help develop therapeutic strategies for RP1 disease, we performed a series of human genetic and animal studies using gene targeted and transgenic mice. Here we report that a frameshift mutation in the 3rd exon of RP1 (c.686delC; p.P229QfsX35) found in a patient with recessive RP1 disease causes RP in the homozygous state, whereas the heterozygous carriers are unaffected, confirming that haploinsufficiency is not the causative mechanism for RP1 disease. We then generated Rp1 knock-in mice with a nonsense Q662X mutation in exon 4, as well as Rp1 transgenic mice carrying a wild-type BAC Rp1 transgene. The Rp1-Q662X allele produces a truncated Rp1 protein, and homozygous Rp1-Q662X mice experience a progressive photoreceptor degeneration characterized disorganization of photoreceptor outer segments. This phenotype could be prevented by expression of a normal amount of Rp1 protein from the BAC transgene without removal of the mutant Rp1-Q662X protein. Over-expression of Rp1 protein in additional BAC Rp1 transgenic lines resulted in retinal degeneration. These findings suggest that the truncated Rp1-Q662X protein does not exert a toxic gain-of-function effect. These results also imply that in principle gene augmentation therapy could be beneficial for both recessive and dominant RP1 patients, but the levels of RP1 protein delivered for therapy will have to be carefully controlled. PMID:22927954

Mice with GFAP-targeted loss of neurofibromin demonstrate increased axonal MET expression with aging.

PubMed

Su, Weiping; Xing, Rubing; Guha, Abhijit; Gutmann, David H; Sherman, Larry S

2007-05-01

Neurofibromatosis 1 (NF1) is a common genetic disease that predisposes patients to peripheral nerve tumors and central nervous system (CNS) abnormalities including low-grade astrocytomas and cognitive disabilities. Using mice with glial fibrillary acidic protein (GFAP)-targeted Nf1 loss (Nf1(GFAP)CKO mice), we found that Nf1(-/-) astrocytes proliferate faster and are more invasive than wild-type astrocytes. In light of our previous finding that aberrant expression of the MET receptor tyrosine kinase contributes to the invasiveness of human NF1-associated malignant peripheral nerve sheath tumors, we sought to determine whether MET expression is aberrant in the brains of Nf1 mutant mice. We found that Nf1(-/-) astrocytes express slightly more MET than wild-type cells in vitro, but do not express elevated MET in situ. However, fiber tracts containing myelinated axons in the hippocampus, midbrain, cerebral cortex, and cerebellum express higher than normal levels of MET in older (> or =6 months) Nf1(GFAP)CKO mice. Both Nf1(GFAP)CKO and wild-type astrocytes induced MET expression in neurites of wild-type hippocampal neurons in vitro, suggesting that astrocyte-derived signals may induce MET in Nf1 mutant mice. Because the Nf1 gene product functions as a RAS GTPase, we examined MET expression in the brains of mice with GFAP-targeted constitutively active forms of RAS. MET was elevated in axonal fiber tracts in mice with active K-RAS but not H-RAS. Collectively, these data suggest that loss of Nf1 in either astrocytes or GFAP(+) neural progenitor cells results in increased axonal MET expression, which may contribute to the CNS abnormalities in children and adults with NF1. (c) 2007 Wiley-Liss, Inc.

Mini-dystrophin restores L-type calcium currents in skeletal muscle of transgenic mdx mice

PubMed Central

Friedrich, O; Both, M; Gillis, J M; Chamberlain, J S; Fink, RHA

2004-01-01

L-type calcium currents (iCa) were recorded using the two-microelectrode voltage-clamp technique in single short toe muscle fibres of three different mouse strains: (i) C57/SV129 wild-type mice (wt); (ii) mdx mice (an animal model for Duchenne muscular dystrophy; and (iii) transgenically engineered mini-dystrophin (MinD)-expressing mdx mice. The activation and inactivation properties of iCa were examined in 2- to 18-month-old animals. Ca2+ current densities at 0 mV in mdx fibres increased with age, but were always significantly smaller compared to age-matched wild-type fibres. Time-to-peak (TTP) of iCa was prolonged in mdx fibres compared to wt fibres. MinD fibres always showed similar TTP and current amplitudes compared to age-matched wt fibres. In all three genotypes, the voltage-dependent inactivation and deactivation of iCa were similar. Intracellular resting calcium concentration ([Ca2+]i) and the distribution of dihydropyridine binding sites were also not different in young animals of all three genotypes, whereas iCa was markedly reduced in mdx fibres. We conclude, that dystrophin influences L-type Ca2+ channels via a direct or indirect linkage which may be disrupted in mdx mice and may be crucial for proper excitation–contraction coupling initiating Ca2+ release from the sarcoplasmic reticulum. This linkage seems to be fully restored in the presence of mini-dystrophin. PMID:14594987

Comparison of Ehrlichia muris strains isolated from wild mice and ticks and serologic survey of humans and animals with E. muris as antigen.

PubMed

Kawahara, M; Ito, T; Suto, C; Shibata, S; Rikihisa, Y; Hata, K; Hirai, K

1999-04-01

In metropolitan Tokyo, the Ehrlichia muris seropositivity rate of 24 wild mice was 63% in Hinohara Village, but in the surrounding areas, it was 0 to 5%. This finding suggests that the reservoir of E. muris is focal. Among the 15 seropositive mice, ehrlichiae were isolated from 9 Apodemus speciosus mice and 1 A. argenteus mouse, respectively. Five ehrlichial isolates were obtained from 10 ticks (Haemaphysalis flava) collected in Asuke Town, Aichi Prefecture, where the E. muris type strain had been isolated. These new isolates were compared with the E. muris type strain. The mouse virulence and ultrastructure of the new isolates were similar to those of the type strain, and all of them were cross-reactive with each other, as well as with the type strain, by indirect immunofluorescent-antibody test. The levels of similarity of the base sequences of the 16S rRNA gene of one of the A. speciosus isolates and one of the tick isolates to that of the E. muris type strain were 99.79 and 99.93%, respectively. We suggest that all of these isolates are E. muris; that E. muris is not limited to Eothenomys kageus but infects other species of mice; and that E. muris is present at locations other than Aichi Prefecture. It appears that H. flava is a potential vector of E. muris. Twenty (1%) of 1803 humans from metropolitan Tokyo were found to be seropositive for E. muris antibodies. A serological survey revealed that exposure to E. muris or organisms antigenically cross-reactive to E. muris occurred among dogs, wild mice, monkeys, bears, deer, and wild boars in Gifu Prefecture, nearby prefectures, and Nagoya City, central Japan. However, human beings and Rattus norvegicus rats in this area were seronegative. These results indicate broader geographic distribution of and human and animal species exposure to E. muris or related Ehrlichia spp. in Japan.

Differential proteomic responses of selectively bred and wild-type Sydney rock oyster populations exposed to elevated CO2.

PubMed

Thompson, E L; O'Connor, W; Parker, L; Ross, P; Raftos, D A

2015-03-01

Previous work suggests that larvae from Sydney rock oysters that have been selectively bred for fast growth and disease resistance are more resilient to the impacts of ocean acidification than nonselected, wild-type oysters. In this study, we used proteomics to investigate the molecular differences between oyster populations in adult Sydney rock oysters and to identify whether these form the basis for observations seen in larvae. Adult oysters from a selective breeding line (B2) and nonselected wild types (WT) were exposed for 4 weeks to elevated pCO2 (856 μatm) before their proteomes were compared to those of oysters held under ambient conditions (375 μatm pCO2 ). Exposure to elevated pCO2 resulted in substantial changes in the proteomes of oysters from both the selectively bred and wild-type populations. When biological functions were assigned, these differential proteins fell into five broad, potentially interrelated categories of subcellular functions, in both oyster populations. These functional categories were energy production, cellular stress responses, the cytoskeleton, protein synthesis and cell signalling. In the wild-type population, proteins were predominantly upregulated. However, unexpectedly, these cellular systems were downregulated in the selectively bred oyster population, indicating cellular dysfunction. We argue that this reflects a trade-off, whereby an adaptive capacity for enhanced mitochondrial energy production in the selectively bred population may help to protect larvae from the effects of elevated CO2 , whilst being deleterious to adult oysters. © 2015 John Wiley & Sons Ltd.

Dietary cladode powder from wild type and domesticated Opuntia species reduces atherogenesis in apoE knock-out mice.

PubMed

Garoby-Salom, Sandra; Guéraud, Françoise; Camaré, Caroline; de la Rosa, Ana-Paulina Barba; Rossignol, Michel; Santos Díaz, María del Socorro; Salvayre, Robert; Negre-Salvayre, Anne

2016-03-01

Dietary intake of Opuntia species may prevent the development of cardiovascular diseases. The present study was designed to characterize the biological antioxidant and anti-inflammatory properties of Opuntia species and to investigate whether Opuntia cladodes prevent the development of atherosclerosis in vivo, in apoE(-)KO mice. The effects of the two Opuntia species, the wild Opuntia streptacantha and the domesticated Opuntia ficus-indica, were tested on the generation of intra- and extracellular reactive oxygen species (ROS) production and kinetics of the LDL oxidation by murine CRL2181 endothelial cells and on the subsequent inflammatory signaling leading to the adhesion of monocytes on the activated endothelium and the formation of foam cells. Opuntia species blocked the extracellular ROS (superoxide anion) generation and LDL oxidation by CRL2181, as well as the intracellular ROS rise and signaling evoked by the oxidized LDL, including the nuclear translocation of the transcription factor NFκB, the expression of ICAM-1 and VCAM-1 adhesion molecules, and the adhesion of monocytes to CRL2181. In vivo, Opuntia significantly reduced the formation of atherosclerotic lesions and the accumulation of 4-hydroxynonenal adducts in the vascular wall of apoE-KO mice, indicating that Opuntia cladodes prevent lipid oxidation in the vascular wall. In conclusion, wild and domesticated Opuntia species exhibit antioxidant, anti-inflammatory, and antiatherogenic properties which emphasize their nutritional benefit for preventing cardiovascular diseases.

Continuous in vivo infusion of interferon-gamma (IFN-γ) enhances engraftment of syngeneic wild-type cells in Fanca–/– and Fancg–/– mice

PubMed Central

Si, Yue; Ciccone, Samantha; Yang, Feng-Chun; Yuan, Jin; Zeng, Daisy; Chen, Shi; van de Vrugt, Henri J.; Critser, John; Arwert, Fre; Haneline, Laura S.; Clapp, D. Wade

2006-01-01

Fanconi anemia (FA) is a heterogeneous genetic disorder characterized by bone marrow (BM) failure and cancer susceptibility. Identification of the cDNAs of FA complementation types allows the potential of using gene transfer technology to introduce functional cDNAs as transgenes into autologous stem cells and provide a cure for the BM failure in FA patients. However, strategies to enhance the mobilization, transduction, and engraftment of exogenous stem cells are required to optimize efficacy prior to widespread clinical use. Hypersensitivity of Fancc–/– cells to interferon-gamma (IFN-γ), a nongenotoxic immune-regulatory cytokine, enhances engraftment of syngeneic wild-type (WT) cells in Fancc–/– mice. However, whether this phenotype is of broad relevance in other FA complementation groups is unresolved. Here we show that primitive and mature myeloid progenitors in Fanca–/– and Fancg–/– mice are hypersensitive to IFN-γ and that in vivo infusion of IFN-γ at clinically relevant concentrations was sufficient to allow consistent long-term engraftment of isogenic WT repopulating stem cells. Given that FANCA, FANCC, and FANCG complementation groups account for more than 90% of all FA patients, these data provide evidence that IFN-γ conditioning may be a useful nongenotoxic strategy for myelopreparation in FA patients. PMID:16946306

Quantitative analysis by next generation sequencing of hematopoietic stem and progenitor cells (LSK) and of splenic B cells transcriptomes from wild-type and Usp3-knockout mice.

PubMed

Lancini, Cesare; Gargiulo, Gaetano; van den Berk, Paul C M; Citterio, Elisabetta

2016-03-01

The data described here provide genome-wide expression profiles of murine primitive hematopoietic stem and progenitor cells (LSK) and of B cell populations, obtained by high throughput sequencing. Cells are derived from wild-type mice and from mice deficient for the ubiquitin-specific protease 3 (USP3; Usp3Δ/Δ). Modification of histone proteins by ubiquitin plays a crucial role in the cellular response to DNA damage (DDR) (Jackson and Durocher, 2013) [1]. USP3 is a histone H2A deubiquitinating enzyme (DUB) that regulates ubiquitin-dependent DDR in response to DNA double-strand breaks (Nicassio et al., 2007; Doil et al., 2008) [2], [3]. Deletion of USP3 in mice increases the incidence of spontaneous tumors and affects hematopoiesis [4]. In particular, Usp3-knockout mice show progressive loss of B and T cells and decreased functional potential of hematopoietic stem cells (HSCs) during aging. USP3-deficient cells, including HSCs, display enhanced histone ubiquitination, accumulate spontaneous DNA damage and are hypersensitive to ionizing radiation (Lancini et al., 2014) [4]. To address whether USP3 loss leads to deregulation of specific molecular pathways relevant to HSC homeostasis and/or B cell development, we have employed the RNA-sequencing technology and investigated transcriptional differences between wild-type and Usp3Δ/Δ LSK, naïve B cells or in vitro activated B cells. The data relate to the research article "Tight regulation of ubiquitin-mediated DNA damage response by USP3 preserves the functional integrity of hematopoietic stem cells" (Lancini et al., 2014) [4]. The RNA-sequencing and analysis data sets have been deposited in NCBI׳s Gene Expression Omnibus (Edgar et al., 2002) [5] and are accessible through GEO Series accession number GSE58495 (http://www.ncbi.nlm.nih.gov/geo/query/acc.cgi?acc=GSE58495). With this article, we present validation of the RNA-seq data set through quantitative real-time PCR and comparative analysis.

Difference in Perseverative Errors during a Visual Attention Task with Auditory Distractors in Alpha-9 Nicotinic Receptor Subunit Wild Type and Knock-Out Mice.

PubMed

Jorratt, Pascal; Delano, Paul H; Delgado, Carolina; Dagnino-Subiabre, Alexies; Terreros, Gonzalo

2017-01-01

The auditory efferent system is a neural network that originates in the auditory cortex and projects to the cochlear receptor through olivocochlear (OC) neurons. Medial OC neurons make cholinergic synapses with outer hair cells (OHCs) through nicotinic receptors constituted by α9 and α10 subunits. One of the physiological functions of the α9 nicotinic receptor subunit (α9-nAChR) is the suppression of auditory distractors during selective attention to visual stimuli. In a recent study we demonstrated that the behavioral performance of alpha-9 nicotinic receptor knock-out (KO) mice is altered during selective attention to visual stimuli with auditory distractors since they made less correct responses and more omissions than wild type (WT) mice. As the inhibition of the behavioral responses to irrelevant stimuli is an important mechanism of the selective attention processes, behavioral errors are relevant measures that can reflect altered inhibitory control. Errors produced during a cued attention task can be classified as premature, target and perseverative errors. Perseverative responses can be considered as an inability to inhibit the repetition of an action already planned, while premature responses can be considered as an index of the ability to wait or retain an action. Here, we studied premature, target and perseverative errors during a visual attention task with auditory distractors in WT and KO mice. We found that α9-KO mice make fewer perseverative errors with longer latencies than WT mice in the presence of auditory distractors. In addition, although we found no significant difference in the number of target error between genotypes, KO mice made more short-latency target errors than WT mice during the presentation of auditory distractors. The fewer perseverative error made by α9-KO mice could be explained by a reduced motivation for reward and an increased impulsivity during decision making with auditory distraction in KO mice.

Epileptogenesis following Kainic Acid-Induced Status Epilepticus in Cyclin D2 Knock-Out Mice with Diminished Adult Neurogenesis

PubMed Central

Kondratiuk, Ilona; Plucinska, Gabriela; Miszczuk, Diana; Wozniak, Grazyna; Szydlowska, Kinga; Kaczmarek, Leszek; Filipkowski, Robert K.; Lukasiuk, Katarzyna

2015-01-01

The goal of this study was to determine whether a substantial decrease in adult neurogenesis influences epileptogenesis evoked by the intra-amygdala injection of kainic acid (KA). Cyclin D2 knockout (cD2 KO) mice, which lack adult neurogenesis almost entirely, were used as a model. First, we examined whether status epilepticus (SE) evoked by an intra-amygdala injection of KA induces cell proliferation in cD2 KO mice. On the day after SE, we injected BrdU into mice for 5 days and evaluated the number of DCX- and DCX/BrdU-immunopositive cells 3 days later. In cD2 KO control animals, only a small number of DCX+ cells was observed. The number of DCX+ and DCX/BrdU+ cells/mm of subgranular layer in cD2 KO mice increased significantly following SE (p<0.05). However, the number of newly born cells was very low and was significantly lower than in KA-treated wild type (wt) mice. To evaluate the impact of diminished neurogenesis on epileptogenesis and early epilepsy, we performed video-EEG monitoring of wt and cD2 KO mice for 16 days following SE. The number of animals with seizures did not differ between wt (11 out of 15) and cD2 KO (9 out of 12) mice. The median latency to the first spontaneous seizure was 4 days (range 2 – 10 days) in wt mice and 8 days (range 2 – 16 days) in cD2 KO mice and did not differ significantly between groups. Similarly, no differences were observed in median seizure frequency (wt: 1.23, range 0.1 – 3.4; cD2 KO: 0.57, range 0.1 – 2.0 seizures/day) or median seizure duration (wt: 51 s, range 23 – 103; cD2 KO: 51 s, range 23 – 103). Our results indicate that SE-induced epileptogenesis is not disrupted in mice with markedly reduced adult neurogenesis. However, we cannot exclude the contribution of reduced neurogenesis to the chronic epileptic state. PMID:26020770

Perception of sweet taste is important for voluntary alcohol consumption in mice.

PubMed

Blednov, Y A; Walker, D; Martinez, M; Levine, M; Damak, S; Margolskee, R F

2008-02-01

To directly evaluate the association between taste perception and alcohol intake, we used three different mutant mice, each lacking a gene expressed in taste buds and critical to taste transduction: alpha-gustducin (Gnat3), Tas1r3 or Trpm5. Null mutant mice lacking any of these three genes showed lower preference score for alcohol and consumed less alcohol in a two-bottle choice test, as compared with wild-type littermates. These null mice also showed lower preference score for saccharin solutions than did wild-type littermates. In contrast, avoidance of quinine solutions was less in Gnat3 or Trpm5 knockout mice than in wild-type mice, whereas Tas1r3 null mice were not different from wild type in their response to quinine solutions. There were no differences in null vs. wild-type mice in their consumption of sodium chloride solutions. To determine the cause for reduction of ethanol intake, we studied other ethanol-induced behaviors known to be related to alcohol consumption. There were no differences between null and wild-type mice in ethanol-induced loss of righting reflex, severity of acute ethanol withdrawal or conditioned place preference for ethanol. Weaker conditioned taste aversion (CTA) to alcohol in null mice may have been caused by weaker rewarding value of the conditioned stimulus (saccharin). When saccharin was replaced by sodium chloride, no differences in CTA to alcohol between knockout and wild-type mice were seen. Thus, deletion of any one of three different genes involved in detection of sweet taste leads to a substantial reduction of alcohol intake without any changes in pharmacological actions of ethanol.

PERCEPTION OF SWEET TASTE IS IMPORTANT FOR VOLUNTARY ALCOHOL CONSUMPTION IN MICE

PubMed Central

Blednov, Y.A.; Walker, D.; Martinez, M.; Levine, M.; Damak, S.; Margolskee, R.F.

2012-01-01

To directly evaluate the association between taste perception and alcohol intake, we used three different mutant mice, each lacking a gene expressed in taste buds and critical to taste transduction: α-gustducin (Gnat3), Tas1r3 or Trpm5. Null mutant mice lacking any of these three genes showed lower preference score for alcohol and consumed less alcohol in a two-bottle choice test, as compared with wild-type littermates. These null mice also showed lower preference score for saccharin solutions than did wild-type littermates. In contrast, avoidance of quinine solutions was less in Gnat3 or Trpm5 knockout mice than in wild type mice, whereas Tas1r3 null mice were not different from wild-type in their response to quinine solutions. There were no differences in null vs. wild-type mice in their consumption of sodium chloride solutions. To determine the cause for reduction of ethanol intake, we studied other ethanol-induced behaviors known to be related to alcohol consumption. There were no differences between null and wild-type mice in ethanol-induced loss of righting reflex, severity of acute ethanol withdrawal or conditioned place preference for ethanol. Weaker conditioned taste aversion to alcohol in null mice may have been caused by weaker rewarding value of the conditioned stimulus (saccharin). When saccharin was replaced by sodium chloride, no differences in conditioned taste aversion to alcohol between knockout and wild-type mice were seen. Thus, deletion of any one of three different genes involved in detection of sweet taste leads to a substantial reduction of alcohol intake without any changes in pharmacological actions of ethanol. PMID:17376151

Peripubertal Vitamin D3 Deficiency Delays Puberty and Disrupts the Estrous Cycle in Adult Female Mice1

PubMed Central

Dicken, Cary L.; Israel, Davelene D.; Davis, Joe B.; Sun, Yan; Shu, Jun; Hardin, John; Neal-Perry, Genevieve

2012-01-01

ABSTRACT The mechanism(s) by which vitamin D3 regulates female reproduction is minimally understood. We tested the hypothesis that peripubertal vitamin D3 deficiency disrupts hypothalamic-pituitary-ovarian physiology. To test this hypothesis, we used wild-type mice and Cyp27b1 (the rate-limiting enzyme in the synthesis of 1,25-dihydroxyvitamin D3) null mice to study the effect of vitamin D3 deficiency on puberty and reproductive physiology. At the time of weaning, mice were randomized to a vitamin D3-replete or -deficient diet supplemented with calcium. We assessed the age of vaginal opening and first estrus (puberty markers), gonadotropin levels, ovarian histology, ovarian responsiveness to exogenous gonadotropins, and estrous cyclicity. Peripubertal vitamin D3 deficiency significantly delayed vaginal opening without affecting the number of GnRH-immunopositive neurons or estradiol-negative feedback on gonadotropin levels during diestrus. Young adult females maintained on a vitamin D3-deficient diet after puberty had arrested follicular development and prolonged estrous cycles characterized by extended periods of diestrus. Ovaries of vitamin D3-deficient Cyp27b1 null mice responded to exogenous gonadotropins and deposited significantly more oocytes into the oviducts than mice maintained on a vitamin D3-replete diet. Estrous cycles were restored when vitamin D3-deficient Cyp27b1 null young adult females were transferred to a vitamin D3-replete diet. This study is the first to demonstrate that peripubertal vitamin D3 sufficiency is important for an appropriately timed pubertal transition and maintenance of normal female reproductive physiology. These data suggest vitamin D3 is a key regulator of neuroendocrine and ovarian physiology. PMID:22572998

Sequence analysis of chromosome 1 revealed different selection patterns between Chinese wild mice and laboratory strains.

PubMed

Xu, Fuyi; Hu, Shixian; Chao, Tianzhu; Wang, Maochun; Li, Kai; Zhou, Yuxun; Xu, Hongyan; Xiao, Junhua

2017-10-01

Both natural and artificial selection play a critical role in animals' adaptation to the environment. Detection of the signature of selection in genomic regions can provide insights for understanding the function of specific phenotypes. It is generally assumed that laboratory mice may experience intense artificial selection while wild mice more natural selection. However, the differences of selection signature in the mouse genome and underlying genes between wild and laboratory mice remain unclear. In this study, we used two mouse populations: chromosome 1 (Chr 1) substitution lines (C1SLs) derived from Chinese wild mice and mouse genome project (MGP) sequenced inbred strains and two selection detection statistics: Fst and Tajima's D to identify the signature of selection footprint on Chr 1. For the differentiation between the C1SLs and MGP, 110 candidate selection regions containing 47 protein coding genes were detected. A total of 149 selection regions which encompass 7.215 Mb were identified in the C1SLs by Tajima's D approach. While for the MGP, we identified nearly twice selection regions (243) compared with the C1SLs which accounted for 13.27 Mb Chr 1 sequence. Through functional annotation, we identified several biological processes with significant enrichment including seven genes in the olfactory transduction pathway. In addition, we searched the phenotypes associated with the 47 candidate selection genes identified by Fst. These genes were involved in behavior, growth or body weight, mortality or aging, and immune systems which align well with the phenotypic differences between wild and laboratory mice. Therefore, the findings would be helpful for our understanding of the phenotypic differences between wild and laboratory mice and applications for using this new mouse resource (C1SLs) for further genetics studies.

Variations of L- and D-amino acid levels in the brain of wild-type and mutant mice lacking D-amino acid oxidase activity.

PubMed

Du, Siqi; Wang, Yadi; Weatherly, Choyce A; Holden, Kylie; Armstrong, Daniel W

2018-05-01

D-amino acids are now recognized to be widely present in organisms and play essential roles in biological processes. Some D-amino acids are metabolized by D-amino acid oxidase (DAO), while D-Asp and D-Glu are metabolized by D-aspartate oxidase (DDO). In this study, levels of 22 amino acids and the enantiomeric compositions of the 19 chiral proteogenic entities have been determined in the whole brain of wild-type ddY mice (ddY/DAO +/+ ), mutant mice lacking DAO activity (ddY/DAO -/- ), and the heterozygous mice (ddY/DAO +/- ) using high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). No significant differences were observed for L-amino acid levels among the three strains except for L-Trp which was markedly elevated in the DAO +/- and DAO -/- mice. The question arises as to whether this is an unknown effect of DAO inactivity. The three highest levels of L-amino acids were L-Glu, L-Asp, and L-Gln in all the three strains. The lowest L-amino acid level was L-Cys in ddY/DAO +/- and ddY/DAO -/- mice, while L-Trp showed the lowest level in ddY/DAO +/+ mice. The highest concentration of D-amino acid was found to be D-Ser, which also had the highest % D value (~ 25%). D-Glu had the lowest % D value (~ 0.01%) in all the three strains. Significant differences of D-Leu, D-Ala, D-Ser, D-Arg, and D-Ile were observed in ddY/DAO +/- and ddY/DAO -/- mice compared to ddY/DAO +/+ mice. This work provides the most complete baseline analysis of L- and D-amino acids in the brains of ddY/DAO +/+ , ddY/DAO +/- , and ddY/DAO -/- mice yet reported. It also provides the most effective and efficient analytical approach for measuring these analytes in biological samples. This study provides fundamental information on the role of DAO in the brain and may be relevant for future development involving novel drugs for DAO regulation.

Compensation for PKMζ in long-term potentiation and spatial long-term memory in mutant mice.

PubMed

Tsokas, Panayiotis; Hsieh, Changchi; Yao, Yudong; Lesburguères, Edith; Wallace, Emma Jane Claire; Tcherepanov, Andrew; Jothianandan, Desingarao; Hartley, Benjamin Rush; Pan, Ling; Rivard, Bruno; Farese, Robert V; Sajan, Mini P; Bergold, Peter John; Hernández, Alejandro Iván; Cottrell, James E; Shouval, Harel Z; Fenton, André Antonio; Sacktor, Todd Charlton

2016-05-17

PKMζ is a persistently active PKC isoform proposed to maintain late-LTP and long-term memory. But late-LTP and memory are maintained without PKMζ in PKMζ-null mice. Two hypotheses can account for these findings. First, PKMζ is unimportant for LTP or memory. Second, PKMζ is essential for late-LTP and long-term memory in wild-type mice, and PKMζ-null mice recruit compensatory mechanisms. We find that whereas PKMζ persistently increases in LTP maintenance in wild-type mice, PKCι/λ, a gene-product closely related to PKMζ, persistently increases in LTP maintenance in PKMζ-null mice. Using a pharmacogenetic approach, we find PKMζ-antisense in hippocampus blocks late-LTP and spatial long-term memory in wild-type mice, but not in PKMζ-null mice without the target mRNA. Conversely, a PKCι/λ-antagonist disrupts late-LTP and spatial memory in PKMζ-null mice but not in wild-type mice. Thus, whereas PKMζ is essential for wild-type LTP and long-term memory, persistent PKCι/λ activation compensates for PKMζ loss in PKMζ-null mice.

Inhibitory Effects of North American Wild Rice on Monocyte Adhesion and Inflammatory Modulators in Low-Density Lipoprotein Receptor-Knockout Mice.

PubMed

Moghadasian, Mohammed H; Zhao, Ruozhi; Ghazawwi, Nora; Le, Khuong; Apea-Bah, Franklin B; Beta, Trust; Shen, Garry X

2017-10-18

The present study examined the effects of wild rice on monocyte adhesion, inflammatory and fibrinolytic mediators in low-density lipoprotein receptor-knockout (LDLr-KO) mice. Male LDLr-KO mice received a cholesterol (0.06%, w/w)-supplemented diet with or without white or wild rice (60%, w/w) for 20 weeks. White rice significantly increased monocyte adhesion and abundances of monocyte chemoattractant protein-1, tissue necrosis factor-α, intracellular cell adhesion molecule-1, plasminogen activator inhibitor-1, urokinase plasminogen activator (uPA), and uPA receptor in aortae and hearts of LDLr-KO mice compared to the control diet. Wild rice inhibited monocyte adhesion to the aorta, atherosclerosis, and abundances of the inflammatory and fibrinolytic regulators in the cardiovascular tissue of LDLr-KO mice compared to white rice. White or wild rice did not significantly alter the levels of cholesterol, triglycerides, or antioxidant enzymes in plasma. The anti-atherosclerotic effect of wild rice may result from its inhibition on monocyte adhesion and inflammatory modulators in LDLr-KO mice.

Glucagon Receptor Knockout Prevents Insulin-Deficient Type 1 Diabetes in Mice

PubMed Central

Lee, Young; Wang, May-Yun; Du, Xiu Quan; Charron, Maureen J.; Unger, Roger H.

2011-01-01

OBJECTIVE To determine the role of glucagon action in the metabolic phenotype of untreated insulin deficiency. RESEARCH DESIGN AND METHODS We compared pertinent clinical and metabolic parameters in glucagon receptor-null (Gcgr−/−) mice and wild-type (Gcgr+/+) controls after equivalent destruction of β-cells. We used a double dose of streptozotocin to maximize β-cell destruction. RESULTS Gcgr+/+ mice became hyperglycemic (>500 mg/dL), hyperketonemic, polyuric, and cachectic and had to be killed after 6 weeks. Despite comparable β-cell destruction in Gcgr−/− mice, none of the foregoing clinical or laboratory manifestations of diabetes appeared. There was marked α-cell hyperplasia and hyperglucagonemia (∼1,200 pg/mL), but hepatic phosphorylated cAMP response element binding protein and phosphoenolpyruvate carboxykinase mRNA were profoundly reduced compared with Gcgr+/+ mice with diabetes—evidence that glucagon action had been effectively blocked. Fasting glucose levels and oral and intraperitoneal glucose tolerance tests were normal. Both fasting and nonfasting free fatty acid levels and nonfasting β-hydroxy butyrate levels were lower. CONCLUSIONS We conclude that blocking glucagon action prevents the deadly metabolic and clinical derangements of type 1 diabetic mice. PMID:21270251

Perinatal Lead Exposure Alters Gut Microbiota Composition and Results in Sex-specific Bodyweight Increases in Adult Mice.

PubMed

Wu, Jianfeng; Wen, Xiaoquan William; Faulk, Christopher; Boehnke, Kevin; Zhang, Huapeng; Dolinoy, Dana C; Xi, Chuanwu

2016-06-01

Heavy metal pollution is a principle source of environmental contamination. Epidemiological and animal data suggest that early life lead (Pb) exposure results in critical effects on epigenetic gene regulation and child and adult weight trajectories. Using a mouse model of human-relevant exposure, we investigated the effects of perinatal Pb exposure on gut microbiota in adult mice, and the link between gut microbiota and bodyweight changes. Following Pb exposure during gestation and lactation via maternal drinking water, bodyweight in A(vy) strain wild-type non-agouti (a/a) offspring was tracked through adulthood. Gut microbiota of adult mice were characterized by deep DNA sequencing of bacterial 16S ribosomal RNA genes. Data analyses were stratified by sex and adjusted for litter effects. A Bayesian variable selection algorithm was used to analyze associations between bacterial operational taxonomic units and offspring adult bodyweight. Perinatal Pb exposure was associated with increased adult bodyweight in male (P < .05) but not in female offspring (P = .24). Cultivable aerobes decreased and anaerobes increased in Pb-exposed offspring (P < .005 and P < .05, respectively). Proportions of the 2 predominant phyla (Bacteroidetes and Firmicutes) shifted inversely with Pb exposure, and whole bacterial compositions were significantly different (analysis of molecular variance, P < .05) by Pb exposure without sex bias. In males, changes in gut microbiota were highly associated with adult bodyweight (P = .028; effect size = 2.59). Thus, perinatal Pb exposure results in altered adult gut microbiota regardless of sex, and these changes are highly correlated with increased bodyweight in males. Adult gut microbiota can be shaped by early exposures and may contribute to disease risks in a sex-specific manner. © The Author 2016. Published by Oxford University Press on behalf of the Society of Toxicology. All rights reserved. For Permissions, please e

Perinatal Lead Exposure Alters Gut Microbiota Composition and Results in Sex-specific Bodyweight Increases in Adult Mice

PubMed Central

Wu, Jianfeng; Wen, Xiaoquan William; Faulk, Christopher; Boehnke, Kevin; Zhang, Huapeng; Dolinoy, Dana C.; Xi, Chuanwu

2016-01-01

Heavy metal pollution is a principle source of environmental contamination. Epidemiological and animal data suggest that early life lead (Pb) exposure results in critical effects on epigenetic gene regulation and child and adult weight trajectories. Using a mouse model of human-relevant exposure, we investigated the effects of perinatal Pb exposure on gut microbiota in adult mice, and the link between gut microbiota and bodyweight changes. Following Pb exposure during gestation and lactation via maternal drinking water, bodyweight in Avy strain wild-type non-agouti (a/a) offspring was tracked through adulthood. Gut microbiota of adult mice were characterized by deep DNA sequencing of bacterial 16S ribosomal RNA genes. Data analyses were stratified by sex and adjusted for litter effects. A Bayesian variable selection algorithm was used to analyze associations between bacterial operational taxonomic units and offspring adult bodyweight. Perinatal Pb exposure was associated with increased adult bodyweight in male (P < .05) but not in female offspring (P = .24). Cultivable aerobes decreased and anaerobes increased in Pb-exposed offspring (P < .005 and P < .05, respectively). Proportions of the 2 predominant phyla (Bacteroidetes and Firmicutes) shifted inversely with Pb exposure, and whole bacterial compositions were significantly different (analysis of molecular variance, P < .05) by Pb exposure without sex bias. In males, changes in gut microbiota were highly associated with adult bodyweight (P = .028; effect size = 2.59). Thus, perinatal Pb exposure results in altered adult gut microbiota regardless of sex, and these changes are highly correlated with increased bodyweight in males. Adult gut microbiota can be shaped by early exposures and may contribute to disease risks in a sex-specific manner. PMID:26962054

BOLD Imaging in Awake Wild-Type and Mu-Opioid Receptor Knock-Out Mice Reveals On-Target Activation Maps in Response to Oxycodone

PubMed Central

Moore, Kelsey; Madularu, Dan; Iriah, Sade; Yee, Jason R.; Kulkarni, Praveen; Darcq, Emmanuel; Kieffer, Brigitte L.; Ferris, Craig F.

2016-01-01

Blood oxygen level dependent (BOLD) imaging in awake mice was used to identify differences in brain activity between wild-type, and Mu (μ) opioid receptor knock-outs (MuKO) in response to oxycodone (OXY). Using a segmented, annotated MRI mouse atlas and computational analysis, patterns of integrated positive and negative BOLD activity were identified across 122 brain areas. The pattern of positive BOLD showed enhanced activation across the brain in WT mice within 15 min of intraperitoneal administration of 2.5 mg of OXY. BOLD activation was detected in 72 regions out of 122, and was most prominent in areas of high μ opioid receptor density (thalamus, ventral tegmental area, substantia nigra, caudate putamen, basal amygdala, and hypothalamus), and focus on pain circuits indicated strong activation in major pain processing centers (central amygdala, solitary tract, parabrachial area, insular cortex, gigantocellularis area, ventral thalamus primary sensory cortex, and prelimbic cortex). Importantly, the OXY-induced positive BOLD was eliminated in MuKO mice in most regions, with few exceptions (some cerebellar nuclei, CA3 of the hippocampus, medial amygdala, and preoptic areas). This result indicates that most effects of OXY on positive BOLD are mediated by the μ opioid receptor (on-target effects). OXY also caused an increase in negative BOLD in WT mice in few regions (16 out of 122) and, unlike the positive BOLD response the negative BOLD was only partially eliminated in the MuKO mice (cerebellum), and in some case intensified (hippocampus). Negative BOLD analysis therefore shows activation and deactivation events in the absence of the μ receptor for some areas where receptor expression is normally extremely low or absent (off-target effects). Together, our approach permits establishing opioid-induced BOLD activation maps in awake mice. In addition, comparison of WT and MuKO mutant mice reveals both on-target and off-target activation events, and set an OXY brain

Acute tau knockdown in the hippocampus of adult mice causes learning and memory deficits.

PubMed

Velazquez, Ramon; Ferreira, Eric; Tran, An; Turner, Emily C; Belfiore, Ramona; Branca, Caterina; Oddo, Salvatore

2018-05-10

Misfolded and hyperphosphorylated tau accumulates in several neurodegenerative disorders including Alzheimer's disease, frontotemporal dementia with Parkinsonism, corticobasal degeneration, progressive supranuclear palsy, Down syndrome, and Pick's disease. Tau is a microtubule-binding protein, and its role in microtubule stabilization is well defined. In contrast, while growing evidence suggests that tau is also involved in synaptic physiology, a complete assessment of tau function in the adult brain has been hampered by robust developmental compensation of other microtubule-binding proteins in tau knockout mice. To circumvent these developmental compensations and assess the role of tau in the adult brain, we generated an adeno-associated virus (AAV) expressing a doxycycline-inducible short-hairpin (Sh) RNA targeted to tau, herein referred to as AAV-ShRNATau. We performed bilateral stereotaxic injections in 7-month-old C57Bl6/SJL wild-type mice with either the AAV-ShRNATau or a control AAV. We found that acute knockdown of tau in the adult hippocampus significantly impaired motor coordination and spatial memory. Blocking the expression of the AAV-ShRNATau, thereby allowing tau levels to return to control levels, restored motor coordination and spatial memory. Mechanistically, the reduced tau levels were associated with lower BDNF levels, reduced levels of synaptic proteins associated with learning, and decreased spine density. We provide compelling evidence that tau is necessary for motor and cognitive function in the adult brain, thereby firmly supporting that tau loss-of-function may contribute to the clinical manifestations of many tauopathies. These findings have profound clinical implications given that anti-tau therapies are in clinical trials for Alzheimer's disease. © 2018 The Authors. Aging Cell published by the Anatomical Society and John Wiley & Sons Ltd.

Differential long-term effects of MDMA on the serotoninergic system and hippocampal cell proliferation in 5-HTT knock-out vs. wild-type mice.

PubMed

Renoir, Thibault; Païzanis, Eleni; El Yacoubi, Malika; Saurini, Françoise; Hanoun, Naïma; Melfort, Maxette; Lesch, Klaus Peter; Hamon, Michel; Lanfumey, Laurence

2008-12-01

Although numerous studies investigated the mechanisms underlying 3,4-methylenedioxymethamphetamine (MDMA)-induced neurotoxicity, little is known about its long-term functional consequences on 5-HT neurotransmission in mice. This led us to evaluate the delayed effects of MDMA exposure on the 5-HT system, using in-vitro and in-vivo approaches in both 5-HTT wild-type and knock-out mice. Acute MDMA in-vitro application on slices of the dorsal raphe nucleus (DRN) induced concentration-dependent 5-HT release and 5-HT cell firing inhibition. Four weeks after MDMA administration (20 mg/kg b.i.d for 4 d), a 2-fold increase in the potency of the 5-HT1A receptor agonist ipsapirone to inhibit the discharge of DRN 5-HT neurons and a larger hypothermic response to 8-OH-DPAT were observed in MDMA- compared to saline-treated mice. This adaptive 5-HT1A autoreceptor supersensitivity was associated with decreases in 5-HT levels but no changes of [3H]citalopram binding in brain. Long-term MDMA treatment also induced a 30% decrease in BrdU labelling of proliferating hippocampal cells and an increased immobility duration in the forced swim test suggesting a depressive-like behaviour induced by MDMA treatment. All these effects were abolished in 5-HTT-/- knock-out mice. These data indicated that, in mice, MDMA administration induced a delayed adaptive supersensitivity of 5-HT1A autoreceptors in the DRN, a deficit in hippocampal cell proliferation and a depressive-like behaviour. These 5-HTT-dependent effects, opposite to those of antidepressants, might contribute to MDMA-induced mood disorders.

Akt-mediated cardioprotective effects of aldosterone in type 2 diabetic mice.

PubMed

Fazal, Loubina; Azibani, Feriel; Bihry, Nicolas; Coutance, Guillaume; Polidano, Evelyne; Merval, Régine; Vodovar, Nicolas; Launay, Jean-Marie; Delcayre, Claude; Samuel, Jane-Lise

2014-06-01

Studies have shown that aldosterone would have angiogenic effects and therefore would be beneficial in the context of cardiovascular diseases. We thus investigated the potential involvement of aldosterone in triggering a cardiac angiogenic response in the context of type-2 diabetes and the molecular pathways involved. Male 3-wk-old aldosterone synthase (AS)-overexpressing mice and their control wild-type (WT) littermates were fed a standard or high-fat, high-sucrose (HFHS) diet. After 6 mo of diet treatment, mice were euthanized, and cardiac samples were assayed by RT-PCR, immunoblotting, and immunohistology. HFHS diet induced type-2 diabetes in WT (WT-D) and AS (AS-D) mice. VEGFa mRNAs decreased in WT-D (-43%, P<0.05 vs. WT) and increased in AS-D mice (+236%, P< 0.01 vs. WT-D). In WT-D mouse hearts, the proapoptotic p38MAPK was activated (P<0.05 vs. WT and AS-D), whereas Akt activity decreased (-64%, P<0.05 vs. WT). The AS mice, which exhibited a cardiac up-regulation of IGF1-R, showed an increase in Akt phosphorylation when diabetes was induced (P<0.05 vs. WT and AS-D). Contrary to WT-D mice, AS-D mouse hearts did not express inflammatory markers and exhibited a normal capillary density (P<0.05 vs. WT-D). To our knowledge, this is the first study providing new insights into the mechanisms whereby aldosterone prevents diabetes-induced cardiac disorders. © FASEB.

Compensation for PKMζ in long-term potentiation and spatial long-term memory in mutant mice

PubMed Central

Tsokas, Panayiotis; Hsieh, Changchi; Yao, Yudong; Lesburguères, Edith; Wallace, Emma Jane Claire; Tcherepanov, Andrew; Jothianandan, Desingarao; Hartley, Benjamin Rush; Pan, Ling; Rivard, Bruno; Farese, Robert V; Sajan, Mini P; Bergold, Peter John; Hernández, Alejandro Iván; Cottrell, James E; Shouval, Harel Z; Fenton, André Antonio; Sacktor, Todd Charlton

2016-01-01

PKMζ is a persistently active PKC isoform proposed to maintain late-LTP and long-term memory. But late-LTP and memory are maintained without PKMζ in PKMζ-null mice. Two hypotheses can account for these findings. First, PKMζ is unimportant for LTP or memory. Second, PKMζ is essential for late-LTP and long-term memory in wild-type mice, and PKMζ-null mice recruit compensatory mechanisms. We find that whereas PKMζ persistently increases in LTP maintenance in wild-type mice, PKCι/λ, a gene-product closely related to PKMζ, persistently increases in LTP maintenance in PKMζ-null mice. Using a pharmacogenetic approach, we find PKMζ-antisense in hippocampus blocks late-LTP and spatial long-term memory in wild-type mice, but not in PKMζ-null mice without the target mRNA. Conversely, a PKCι/λ-antagonist disrupts late-LTP and spatial memory in PKMζ-null mice but not in wild-type mice. Thus, whereas PKMζ is essential for wild-type LTP and long-term memory, persistent PKCι/λ activation compensates for PKMζ loss in PKMζ-null mice. DOI: http://dx.doi.org/10.7554/eLife.14846.001 PMID:27187150

The ESA Mice in Space (MIS) habitat: effects of cage confinement on neuromusculoskeletal structure and function and stress/behavior using wild-type C57Bl/6JRj mice in a modular science reference model (MSRM) test on ground

NASA Astrophysics Data System (ADS)

Blottner, Dieter; Vico, Laurence; Jamon, D. Berckmansp L. Vicop Y. Liup R. Canceddap M.

Background: Environmental conditions likely affect physiology and behaviour of mice used for Life Sciences Research on Earth and in Space. Thus, mice habitats with sufficient statistical numbers should be developed for adequate life support and care and that should meet all nesces-sary ethical and scientific requirements needed to successfully perform animal experimentation in Space. Aim of study: We here analysed the effects of cage confinement on the weightbear-ing musculoskeletal system, behaviour and stress of wild-type mice (C57BL/6JRj, 30 g b.wt., total n = 24) housed for 25 days in a prototypical ground-based MSRM (modular science ref-erence module) in the frame of breadboard activities for a fully automated life support habitat called "Mice in Space" (MIS) at the Leuven University, Belgium. Results: Compared with control housing (individually ventilated cages, IVC-mice) the MIS mice revealed no significant changes in soleus muscle size and myofiber distribution (type I vs. II) and quality of bone (3-D microarchitecture and mineralisation of calvaria, spine and femur) determined by confocal and micro-computed tomography. Corticosterone metabolism measured non-invasively (faeces) monitored elevated adrenocortical activity at only start of the MIS cage confinement (day 1). Behavioural tests (i.e., grip strength, rotarod, L/D box, elevated plus-maze, open field, ag-gressiveness) performed subsequently revealed only minor changes in motor performance (MIS vs. controls). Conclusions: The MIS habitat will not, on its own, produce major effects that could confound interpretation of data induced by microgravity exposure on orbit as planned for future biosatellite programmes. Sponsors: ESA-ESTEC, Noordwijk, NL

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.

Rearing-environment-dependent hippocampal local field potential differences in wild-type and inositol trisphosphate receptor type 2 knockout mice.

PubMed

Tanaka, Mika; Wang, Xiaowen; Mikoshiba, Katsuhiko; Hirase, Hajime; Shinohara, Yoshiaki

2017-10-15

Mice reared in an enriched environment are demonstrated to have larger hippocampal gamma oscillations than those reared in isolation, thereby confirming previous observations in rats. To test whether astrocytic Ca 2+ surges are involved in this experience-dependent LFP pattern modulation, we used inositol trisphosphate receptor type 2 (IP 3 R2)-knockout (KO) mice, in which IP 3 /Ca 2+ signalling in astrocytes is largely diminished. We found that this experience-dependent gamma power alteration persists in the KO mice. Interestingly, hippocampal ripple events, the synchronized events critical for memory consolidation, are reduced in magnitude and frequency by both isolated rearing and IP 3 R2 deficiency. Rearing in an enriched environment (ENR) is known to enhance cognitive and memory abilities in rodents, whereas social isolation (ISO) induces depression-like behaviour. The hippocampus has been documented to undergo morphological and functional changes depending on these rearing environments. For example, rearing condition during juvenility alters CA1 stratum radiatum gamma oscillation power in rats. In the present study, hippocampal CA1 local field potentials (LFP) were recorded from bilateral CA1 in urethane-anaesthetized mice that were reared in either an ENR or ISO condition. Similar to previous findings in rats, gamma oscillation power during theta states was higher in the ENR group. Ripple events that occur during non-theta periods in the CA1 stratum pyramidale also had longer intervals in ISO mice. Because astrocytic Ca 2+ elevations play a key role in synaptic plasticity, we next tested whether these changes in LFP are also expressed in inositol trisphosphate receptor type 2 (IP 3 R2)-knockout (KO) mice, in which astrocytic Ca 2+ elevations are largely diminished. We found that the gamma power was also higher in IP 3 R2-KO-ENR mice compared to IP 3 R2-KO-ISO mice, suggesting that the rearing-environment-dependent gamma power alteration does not necessarily

Prodepressant- and anxiogenic-like effects of serotonin-selective, but not noradrenaline-selective, antidepressant agents in mice lacking α2-containing GABAA receptors.

PubMed

Benham, Rebecca S; Hewage, Nishani B; Suckow, Raymond F; Engin, Elif; Rudolph, Uwe

2017-08-14

Deficits in neuronal inhibition via gamma-aminobutyric acid (GABA) type A receptors (GABAA-Rs) are implicated in the pathophysiology of major depressive disorder and the therapeutic effects of current antidepressant treatments, however, the relevant GABAA-R subtype as defined by its alpha subunit is still unknown. We previously reported anxiety- and depressive-like behavior in alpha2+/- and alpha2-/- mice, respectively (Vollenweider, 2011). We sought to determine whether this phenotype could be reversed by chronic antidepressant treatment. Adult male mice received 4 or 8mg/kg fluoxetine or 53mg/kg desipramine in their drinking water for four weeks before undergoing behavioral testing. In the novelty suppressed feeding test, desipramine had anxiolytic-like effects reducing the latencies to bite and to eat the pellet in both wild-type and alpha2+/- mice. Surprisingly, 4mg/kg fluoxetine had anxiogenic-like effects in alpha2+/- mice increasing latency to bite and to eat while 8mg/kg fluoxetine increased the latency to eat in both wild-type and alpha2+/- mice. In the forced swim and tail suspension tests, chronic desipramine treatment increased latency to immobility in wild-type and alpha2-/- mice. In contrast, chronic fluoxetine treatment increased immobility in alpha2-/- mice in both tasks while generally having no effect in wild-type mice. These findings suggest that in preclinical paradigms of anxiety and behavioral despair the antidepressant-like effects of desipramine are independent of alpha2-containing GABAA-Rs, while a reduction in alpha2 expression leads to an increased sensitivity to anxiogenic- and prodepressant-like effects with chronic fluoxetine treatment, pointing to a potential role of alpha2-containing GABAA-Rs in the response to serotonin-selective antidepressants. Copyright © 2017 Elsevier B.V. All rights reserved.

Glutaminyl Cyclase Knock-out Mice Exhibit Slight Hypothyroidism but No Hypogonadism

PubMed Central

Schilling, Stephan; Kohlmann, Stephanie; Bäuscher, Christoph; Sedlmeier, Reinhard; Koch, Birgit; Eichentopf, Rico; Becker, Andreas; Cynis, Holger; Hoffmann, Torsten; Berg, Sabine; Freyse, Ernst-Joachim; von Hörsten, Stephan; Rossner, Steffen; Graubner, Sigrid; Demuth, Hans-Ulrich

2011-01-01

Glutaminyl cyclases (QCs) catalyze the formation of pyroglutamate (pGlu) residues at the N terminus of peptides and proteins. Hypothalamic pGlu hormones, such as thyrotropin-releasing hormone and gonadotropin-releasing hormone are essential for regulation of metabolism and fertility in the hypothalamic pituitary thyroid and gonadal axes, respectively. Here, we analyzed the consequences of constitutive genetic QC ablation on endocrine functions and on the behavior of adult mice. Adult homozygous QC knock-out mice are fertile and behave indistinguishably from wild type mice in tests of motor function, cognition, general activity, and ingestion behavior. The QC knock-out results in a dramatic drop of enzyme activity in the brain, especially in hypothalamus and in plasma. Other peripheral organs like liver and spleen still contain QC activity, which is most likely caused by its homolog isoQC. The serum gonadotropin-releasing hormone, TSH, and testosterone concentrations were not changed by QC depletion. The serum thyroxine was decreased by 24% in homozygous QC knock-out animals, suggesting a mild hypothyroidism. QC knock-out mice were indistinguishable from wild type with regard to blood glucose and glucose tolerance, thus differing from reports of thyrotropin-releasing hormone knock-out mice significantly. The results suggest a significant formation of the hypothalamic pGlu hormones by alternative mechanisms, like spontaneous cyclization or conversion by isoQC. The different effects of QC depletion on the hypothalamic pituitary thyroid and gonadal axes might indicate slightly different modes of substrate conversion of both enzymes. The absence of significant abnormalities in QC knock-out mice suggests the presence of a therapeutic window for suppression of QC activity in current drug development. PMID:21330373

Effect of Obstructive Jaundice and Nitric Oxide on the Profiles of Intestinal Bacterial Flora in Wild and iNOS−/− Mice

PubMed Central

Hong, Ji-Young; F. Sato, Eisuke; Nishikawa, Tomoko; Hiramoto, Keiichi; Inoue, Masayasu

2009-01-01

We previously reported that the plasma level of endotoxin and colonic expression of IgA in the mouse increased with obstructive jaundice induced by bile duct ligation (BDL). To elucidate the mechanism of the BDL-induced increase, we analyzed the effect of BDL on intestinal flora in wild type and inducible nitric oxide synthase (iNOS)-deficient mice (iNOS−/−) using the terminal restriction fragment length polymorphism analysis (T-RFLP) and 16S rDNA clone libraries. The amounts of bacterial DNA detected in fecal samples from both animal groups pretreated with antibiotics were extremely low as compared with untreated groups. We found that the profiles of enteric bacteria changed markedly after BDL. The bacterial composition is significantly different between not only wild type and iNOS−/− mice but also those before and after BDL, respectively. Among enteric bacteria examined, Lactobacillus murinus was found to increase markedly after BDL in rectum of both animal groups. However, Escherichia coli markedly increased after BDL in the iNOS−/− mice. These findings suggest that profiles of enteric flora change markedly in animals during obstructive jaundice by some mechanism that is affected by bile constituents and iNOS-derived NO. PMID:19308270

A gene capable of blocking apoptosis can substitute for the herpes simplex virus type 1 latency-associated transcript gene and restore wild-type reactivation levels.

PubMed

Perng, Guey-Chuen; Maguen, Barak; Jin, Ling; Mott, Kevin R; Osorio, Nelson; Slanina, Susan M; Yukht, Ada; Ghiasi, Homayon; Nesburn, Anthony B; Inman, Melissa; Henderson, Gail; Jones, Clinton; Wechsler, Steven L

2002-02-01

After ocular herpes simplex virus type 1 (HSV-1) infection, the virus travels up axons and establishes a lifelong latent infection in neurons of the trigeminal ganglia. LAT (latency-associated transcript), the only known viral gene abundantly transcribed during HSV-1 neuronal latency, is required for high levels of reactivation. The LAT function responsible for this reactivation phenotype is not known. Recently, we showed that LAT can block programmed cell death (apoptosis) in neurons of the trigeminal ganglion in vivo and in tissue culture cells in vitro (G.-C. Perng et al., Science 287:1500-1503, 2000; M. Inman et al., J. Virol. 75:3636-3646, 2001). Consequently, we proposed that this antiapoptosis function may be a key to the mechanism by which LAT enhances reactivation. To study this further, we constructed a recombinant HSV-1 virus in which the HSV-1 LAT gene was replaced by an alternate antiapoptosis gene. We used the bovine herpes virus 1 (BHV-1) latency-related (LR) gene, which was previously shown to have antiapoptosis activity, for this purpose. The resulting chimeric virus, designated CJLAT, contains two complete copies of the BHV-1 LR gene (one in each viral long repeat) in place of the normal two copies of the HSV-1 LAT, on an otherwise wild-type HSV-1 strain McKrae genomic background. We report here that in both rabbits and mice reactivation of CJLAT was significantly greater than the LAT null mutant dLAT2903 (P < 0.0004 and P = 0.001, respectively) and was at least as efficient as wild-type McKrae. This strongly suggests that a BHV-1 LR gene function was able to efficiently substitute for an HSV-1 LAT gene function involved in reactivation. Although replication of CJLAT in rabbits and mice was similar to that of wild-type McKrae, CJLAT killed more mice during acute infection and caused more corneal scarring in latently infected rabbits. This suggested that the BHV-1 LR gene and the HSV-1 LAT gene are not functionally identical. However, LR and LAT

Lipoprotein lipase gene-deficient mice with hypertriglyceridaemia associated with acute pancreatitis.

PubMed

Tang, Maochun; Zong, Pengfei; Zhang, Ting; Wang, Dongyan; Wang, Yuhui; Zhao, Yan

2016-10-01

To investigate the severity of pancreatitis in lipoprotein lipase (LPL)-deficient hypertriglyceridaemic (HTG) heterozygous mice and to establish an experimental animal model for HTG pancreatitis study. LPL-deficient HTG heterozygous mice were rescued by somatic gene transfer and mated with wild-type mice. The plasma amylase, triglyceride, and pathologic changes in the pancreas of the LPL-deficient HTG heterozygous mice were compared with those of wild-type mice to assess the severity of pancreatitis. In addition, acute pancreatitis (AP) was induced by caerulein (50 µg/kg) for further assessment. The levels of plasma amylase and triglyceride were significantly higher in the LPL-deficient HTG heterozygous mice. According to the pancreatic histopathologic scores, the LPL-deficient HTG heterozygous mice showed more severe pathologic damage than the wild-type mice. Lipoprotein lipase deficient heterozygous mice developed severe caerulein-induced pancreatitis. In addition, their high triglyceride levels were stable. Therefore, LPL-deficient HTG heterozygous mice are a useful experimental model for studying HTG pancreatitis.

CD8 T cells protect adult naive mice from JEV-induced morbidity via lytic function

PubMed Central

Chawla, Amanpreet Singh; Agrawal, Tanvi; Biswas, Moanaro; Vrati, Sudhanshu; Rath, Satyajit; George, Anna; Medigeshi, Guruprasad R.

2017-01-01

Following Japanese encephalitis virus (JEV) infection neutralizing antibodies are shown to provide protection in a significant proportion of cases, but not all, suggesting additional components of immune system might also contribute to elicit protective immune response. Here we have characterized the role of T cells in offering protection in adult mice infected with JEV. Mice lacking α/β–T cells (TCRβ–null) are highly susceptible and die over 10–18 day period as compared to the wild-type (WT) mice which are resistant. This is associated with high viral load, higher mRNA levels of proinflammatory cytokines and breach in the blood-brain-barrier (BBB). Infected WT mice do not show a breach in BBB; however, in contrast to TCRβ-null, they show the presence of T cells in the brain. Using adoptive transfer of cells with specific genetic deficiencies we see that neither the presence of CD4 T cells nor cytokines such as IL-4, IL-10 or interferon-gamma have any significant role in offering protection from primary infection. In contrast, we show that CD8 T cell deficiency is more critical as absence of CD8 T cells alone increases mortality in mice infected with JEV. Further, transfer of T cells from beige mice with defects in granular lytic function into TCRβ-null mice shows poor protection implicating granule-mediated target cell lysis as an essential component for survival. In addition, for the first time we report that γ/δ-T cells also make significant contribution to confer protection from JEV infection. Our data show that effector CD8 T cells play a protective role during primary infection possibly by preventing the breach in BBB and neuronal damage. PMID:28151989

CD8 T cells protect adult naive mice from JEV-induced morbidity via lytic function.

PubMed

Jain, Nidhi; Oswal, Neelam; Chawla, Amanpreet Singh; Agrawal, Tanvi; Biswas, Moanaro; Vrati, Sudhanshu; Rath, Satyajit; George, Anna; Bal, Vineeta; Medigeshi, Guruprasad R

2017-02-01

Following Japanese encephalitis virus (JEV) infection neutralizing antibodies are shown to provide protection in a significant proportion of cases, but not all, suggesting additional components of immune system might also contribute to elicit protective immune response. Here we have characterized the role of T cells in offering protection in adult mice infected with JEV. Mice lacking α/β-T cells (TCRβ-null) are highly susceptible and die over 10-18 day period as compared to the wild-type (WT) mice which are resistant. This is associated with high viral load, higher mRNA levels of proinflammatory cytokines and breach in the blood-brain-barrier (BBB). Infected WT mice do not show a breach in BBB; however, in contrast to TCRβ-null, they show the presence of T cells in the brain. Using adoptive transfer of cells with specific genetic deficiencies we see that neither the presence of CD4 T cells nor cytokines such as IL-4, IL-10 or interferon-gamma have any significant role in offering protection from primary infection. In contrast, we show that CD8 T cell deficiency is more critical as absence of CD8 T cells alone increases mortality in mice infected with JEV. Further, transfer of T cells from beige mice with defects in granular lytic function into TCRβ-null mice shows poor protection implicating granule-mediated target cell lysis as an essential component for survival. In addition, for the first time we report that γ/δ-T cells also make significant contribution to confer protection from JEV infection. Our data show that effector CD8 T cells play a protective role during primary infection possibly by preventing the breach in BBB and neuronal damage.

Sequence Diversity, Intersubgroup Relationships, and Origins of the Mouse Leukemia Gammaretroviruses of Laboratory and Wild Mice.

PubMed

Bamunusinghe, Devinka; Naghashfar, Zohreh; Buckler-White, Alicia; Plishka, Ronald; Baliji, Surendranath; Liu, Qingping; Kassner, Joshua; Oler, Andrew J; Hartley, Janet; Kozak, Christine A

2016-04-01

Mouse leukemia viruses (MLVs) are found in the common inbred strains of laboratory mice and in the house mouse subspecies ofMus musculus Receptor usage and envelope (env) sequence variation define three MLV host range subgroups in laboratory mice: ecotropic, polytropic, and xenotropic MLVs (E-, P-, and X-MLVs, respectively). These exogenous MLVs derive from endogenous retroviruses (ERVs) that were acquired by the wild mouse progenitors of laboratory mice about 1 million years ago. We analyzed the genomes of seven MLVs isolated from Eurasian and American wild mice and three previously sequenced MLVs to describe their relationships and identify their possible ERV progenitors. The phylogenetic tree based on the receptor-determining regions ofenvproduced expected host range clusters, but these clusters are not maintained in trees generated from other virus regions. Colinear alignments of the viral genomes identified segmental homologies to ERVs of different host range subgroups. Six MLVs show close relationships to a small xenotropic ERV subgroup largely confined to the inbred mouse Y chromosome.envvariations define three E-MLV subtypes, one of which carries duplications of various sizes, sequences, and locations in the proline-rich region ofenv Outside theenvregion, all E-MLVs are related to different nonecotropic MLVs. These results document the diversity in gammaretroviruses isolated from globally distributedMussubspecies, provide insight into their origins and relationships, and indicate that recombination has had an important role in the evolution of these mutagenic and pathogenic agents. Laboratory mice carry mouse leukemia viruses (MLVs) of three host range groups which were acquired from their wild mouse progenitors. We sequenced the complete genomes of seven infectious MLVs isolated from geographically separated Eurasian and American wild mice and compared them with endogenous germ line retroviruses (ERVs) acquired early in house mouse evolution. We did this

Transplantation of wild-type mouse hematopoietic stem and progenitor cells ameliorates deficits in a mouse model of Friedreich’s ataxia

PubMed Central

Rocca, Celine J.; Goodman, Spencer M.; Dulin, Jennifer N.; Haquang, Joseph H.; Gertsman, Ilya; Blondelle, Jordan; Smith, Janell L. M.; Heyser, Charles J.; Cherqui, Stephanie

2017-01-01

Friedreich’s ataxia (FRDA) is an incurable autosomal recessive neurodegenerative disease caused by reduced expression of the mitochondrial protein frataxin due to an intronic GAA-repeat expansion in the FXN gene. We report the therapeutic efficacy of transplanting wild-type mouse hematopoietic stem and progenitor cells (HSPCs) into the YG8R mouse model of FRDA. In the HSPC-transplanted YG8R mice, development of muscle weakness and locomotor deficits was abrogated as was degeneration of large sensory neurons in the dorsal root ganglia (DRGs) and mitochondrial capacity was improved in brain, skeletal muscle, and heart. Transplanted HSPCs engrafted and then differentiated into microglia in the brain and spinal cord and into macrophages in the DRGs, heart, and muscle of YG8R FRDA mice. We observed the transfer of wild-type frataxin and Cox8 mitochondrial proteins from HSPC-derived microglia/macrophages to FRDA mouse neurons and muscle myocytes in vivo. Our results show the HSPC-mediated phenotypic rescue of FRDA in YG8R mice and suggest that this approach should be investigated further as a strategy for treating FRDA. PMID:29070698

The effect of forced exercise on knee joints in Dio2(-/-) mice: type II iodothyronine deiodinase-deficient mice are less prone to develop OA-like cartilage damage upon excessive mechanical stress.

PubMed

Bomer, Nils; Cornelis, Frederique M F; Ramos, Yolande F M; den Hollander, Wouter; Storms, Lies; van der Breggen, Ruud; Lakenberg, Nico; Slagboom, P Eline; Meulenbelt, Ingrid; Lories, Rik J L

2016-03-01

To further explore deiodinase iodothyronine type 2 (DIO2) as a therapeutic target in osteoarthritis (OA) by studying the effects of forced mechanical loading on in vivo joint cartilage tissue homeostasis and the modulating effect herein of Dio2 deficiency. Wild-type and C57BL/6-Dio2(-/-) -mice were subjected to a forced running regime for 1 h per day for 3 weeks. Severity of OA was assessed by histological scoring for cartilage damage and synovitis. Genome-wide gene expression was determined in knee cartilage by microarray analysis (Illumina MouseWG-6 v2). STRING-db analyses were applied to determine enrichment for specific pathways and to visualise protein-protein interactions. In total, 158 probes representing 147 unique genes showed significantly differential expression with a fold-change ≥1.5 upon forced exercise. Among these are genes known for their association with OA (eg, Mef2c, Egfr, Ctgf, Prg4 and Ctnnb1), supporting the use of forced running as an OA model in mice. Dio2-deficient mice showed significantly less cartilage damage and signs of synovitis. Gene expression response upon exercise between wild-type and knockout mice was significantly different for 29 genes. Mice subjected to a running regime have significant increased cartilage damage and synovitis scores. Lack of Dio2 protected against cartilage damage in this model and was reflected in a specific gene expression profile, and either mark a favourable effect in the Dio2 knockout (eg, Gnas) or an unfavourable effect in wild-type cartilage homeostasis (eg, Hmbg2 and Calr). These data further support DIO2 activity as a therapeutic target in OA. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

CuZnSOD gene deletion targeted to skeletal muscle leads to loss of contractile force but does not cause muscle atrophy in adult mice

PubMed Central

Zhang, Yiqiang; Davis, Carol; Sakellariou, George K.; Shi, Yun; Kayani, Anna C.; Pulliam, Daniel; Bhattacharya, Arunabh; Richardson, Arlan; Jackson, Malcolm J.; McArdle, Anne; Brooks, Susan V.; Van Remmen, Holly

2013-01-01

We have previously shown that deletion of CuZnSOD in mice (Sod1−/− mice) leads to accelerated loss of muscle mass and contractile force during aging. To dissect the relative roles of skeletal muscle and motor neurons in this process, we used a Cre-Lox targeted approach to establish a skeletal muscle-specific Sod1-knockout (mKO) mouse to determine whether muscle-specific CuZnSOD deletion is sufficient to cause muscle atrophy. Surprisingly, mKO mice maintain muscle masses at or above those of wild-type control mice up to 18 mo of age. In contrast, maximum isometric specific force measured in gastrocnemius muscle is significantly reduced in the mKO mice. We found no detectable increases in global measures of oxidative stress or ROS production, no reduction in mitochondrial ATP production, and no induction of adaptive stress responses in muscle from mKO mice. However, Akt-mTOR signaling is elevated and the number of muscle fibers with centrally located nuclei is increased in skeletal muscle from mKO mice, which suggests elevated regenerative pathways. Our data demonstrate that lack of CuZnSOD restricted to skeletal muscle does not lead to muscle atrophy but does cause muscle weakness in adult mice and suggest loss of CuZnSOD may potentiate muscle regenerative pathways.—Zhang, Y., Davis, C., Sakellariou, G.K., Shi, Y., Kayani, A.C., Pulliam, D., Bhattacharya, A., Richardson, A., Jackson, M.J., McArdle, A., Brooks, S.V., Van Remmen, H. CuZnSOD gene deletion targeted to skeletal muscle leads to loss of contractile force but does not cause muscle atrophy in adult mice. PMID:23729587

Glutamate induces the elongation of early dendritic protrusions via mGluRs in wild type mice, but not in fragile X mice.

PubMed

Cruz-Martín, Alberto; Crespo, Michelle; Portera-Cailliau, Carlos

2012-01-01

Fragile X syndrome (FXS), the most common inherited from of autism and mental impairment, is caused by transcriptional silencing of the Fmr1 gene, resulting in the loss of the RNA-binding protein FMRP. Dendritic spines of cortical pyramidal neurons in affected individuals are abnormally immature and in Fmr1 knockout (KO) mice they are also abnormally unstable. This could result in defects in synaptogenesis, because spine dynamics are critical for synapse formation. We have previously shown that the earliest dendritic protrusions, which are highly dynamic and might serve an exploratory role to reach out for axons, elongate in response to glutamate. Here, we tested the hypothesis that this process is mediated by metabotropic glutamate receptors (mGluRs) and that it is defective in Fmr1 KO mice. Using time-lapse imaging with two-photon microscopy in acute brain slices from early postnatal mice, we find that early dendritic protrusions in layer 2/3 neurons become longer in response to application of glutamate or DHPG, a Group 1 mGluR agonist. Blockade of mGluR5 signaling, which reverses some adult phenotypes of KO mice, prevented the glutamate-mediated elongation of early protrusions. In contrast, dendritic protrusions from KO mice failed to respond to glutamate. Thus, absence of FMRP may impair the ability of cortical pyramidal neurons to respond to glutamate released from nearby pre-synaptic terminals, which may be a critical step to initiate synaptogenesis and stabilize spines.

High frequency fo X-Y chromosome dissociation in primary spermatocytes of F1 hybrids between Japanese wild mice (Mus musculus molossinus) and inbred laboratory mice.

PubMed

Imai, H T; Matsuda, Y; Shiroishi, T; Moriwaki, K

1981-01-01

In the hybrids between Japanese wild mice (Mus musculus molossinus) and inbred laboratory mice (BALB/c and B10.BR, which were probably derived from M. m. domesticus), the X and Y chromosomes dissociated precociously at the first meiotic metaphase in some 70% of spermatocytes; that percentage was only 8.9% in inbred laboratory mice and 21.1% in wild mice. X-Y dissociation began at least at early diakinesis and continued during metaphase I (MI). Some autosomes of the hybrid (10.1%) and BALB/c (10.6%) mice also dissociated precociously, but there was no distinctive correlation between X-Y and autosomal dissociation. In B10 or B6 congenic lines with a Y chromosome from wild M. m. molossinus, there was an apparent tendency for the percentage of precocious X-Y dissociation to decrease with an increasing number of back cross generations. Based on these observations we concluded that: 1. the X-Y dissociation found is genetically controlled, perhaps by multiple genes; 2. these genes are located on autosomes and are active only when they are heterozygous; 3. the frequent dissociation of the sex chromosomes neither affects male fertility nor induces non-disjunction of the X and Y chromosomes, though it significantly reduces testes weight.

Daily Rhythmic Behaviors and Thermoregulatory Patterns Are Disrupted in Adult Female MeCP2-Deficient Mice

PubMed Central

Wu, Chiping; Bardakjian, Berj L.; Zhang, Liang; Eubanks, James H.

2012-01-01

Mutations in the X-linked gene encoding Methyl-CpG-binding protein 2 (MECP2) have been associated with neurodevelopmental and neuropsychiatric disorders including Rett Syndrome, X-linked mental retardation syndrome, severe neonatal encephalopathy, and Angelman syndrome. Although alterations in the performance of MeCP2-deficient mice in specific behavioral tasks have been documented, it remains unclear whether or not MeCP2 dysfunction affects patterns of periodic behavioral and electroencephalographic (EEG) activity. The aim of the current study was therefore to determine whether a deficiency in MeCP2 is sufficient to alter the normal daily rhythmic patterns of core body temperature, gross motor activity and cortical delta power. To address this, we monitored individual wild-type and MeCP2-deficient mice in their home cage environment via telemetric recording over 24 hour cycles. Our results show that the normal daily rhythmic behavioral patterning of cortical delta wave activity, core body temperature and mobility are disrupted in one-year old female MeCP2-deficient mice. Moreover, female MeCP2-deficient mice display diminished overall motor activity, lower average core body temperature, and significantly greater body temperature fluctuation than wild-type mice in their home-cage environment. Finally, we show that the epileptiform discharge activity in female MeCP2-deficient mice is more predominant during times of behavioral activity compared to inactivity. Collectively, these results indicate that MeCP2 deficiency is sufficient to disrupt the normal patterning of daily biological rhythmic activities. PMID:22523589

Isoflurane unveils a critical role of glutamate transporter type 3 in regulating hippocampal GluR1 trafficking and context-related learning and memory in mice.

PubMed

Cao, J; Wang, Z; Mi, W; Zuo, Z

2014-07-11

Glutamate transporter type 3 (EAAT3) may play a role in cognition. Isoflurane enhances EAAT3 trafficking to the plasma membrane. Thus, we used isoflurane to determine how EAAT3 might regulate learning and memory and the trafficking of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors, such as GluR1, to the plasma membrane, a fundamental biochemical process for learning and memory. Here, isoflurane increased EAAT3 but did not change GluR1 levels in the plasma membrane of wild-type mouse hippocampus. Isoflurane increased protein phosphatase activity in the wild-type and EAAT3(-/-) mouse hippocampus. Also, isoflurane reduced GluR1 in the plasma membrane and decreased phospho-GluR1 in EAAT3(-/-) mice. The phosphatase inhibitor okadaic acid attenuated these effects. Finally, isoflurane inhibited context-related fear conditioning in EAAT3(-/-) mice but not in wild-type mice. Thus, isoflurane may increase GluR1 trafficking to the plasma membrane via EAAT3 and inhibit GluR1 trafficking via protein phosphatase. Lack of EAAT3 effects leads to decreased GluR1 trafficking and impaired cognition after isoflurane exposure in EAAT3(-/-) mice. Copyright © 2014 IBRO. Published by Elsevier Ltd. All rights reserved.

Arthritis is developed in Borrelia-primed and -infected mice deficient of interleukin-17.

PubMed

Kuo, Joseph; Warner, Thomas F; Munson, Erik L; Nardelli, Dean T; Schell, Ronald F

2016-10-01

Interleukin-17 (IL-17) has been shown to participate in the development of Lyme arthritis in experimental mice. For example, neutralization of IL-17 with antibodies inhibits induction of arthritis in Borrelia-primed and -infected C57BL/6 wild-type mice. We hypothesized that mice lacking IL-17 would fail to develop Borrelia-induced arthritis. IL-17-deficient and wild-type C57BL/6 mice were primed with heat-inactivated Borrelia and then infected with viable spirochetes 3 weeks later. No swelling or major histopathological changes of the hind paws were detected in IL-17-deficient or wild-type mice that were primed with Borrelia or infected with viable spirochetes. By contrast, IL-17-deficient and wild-type mice that were primed and subsequently infected with heterologous Borrelia developed severe swelling and histopathological changes of the hind paws. In addition, Borrelia-primed and -infected IL-17-deficient mice exhibited elevated gamma-interferon (IFN-γ) levels in sera and increased frequencies of IFN-γ-expressing lymphocytes in popliteal lymph nodes compared to Borrelia-primed and -infected wild-type mice. These results demonstrate that IL-17 is not required for development of severe pathology in response to infection with Borrelia burgdorferi, but may contribute to disease through an interaction with IFN-γ. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Deficiency of intestinal mucin-2 ameliorates experimental alcoholic liver disease in mice

PubMed Central

Hartmann, Phillipp; Chen, Peng; Wang, Hui J.; Wang, Lirui; McCole, Declan F.; Brandl, Katharina; Stärkel, Peter; Belzer, Clara; Hellerbrand, Claus; Tsukamoto, Hidekazu; Ho, Samuel B.; Schnabl, Bernd

2013-01-01

The intestinal mucus layer protects the epithelium from noxious agents, viruses, and pathogenic bacteria present in the gastrointestinal tract. It is composed of mucins, predominantly mucin-2 (Muc2), secreted by goblet cells of the intestine. Experimental alcoholic liver disease requires translocation of bacterial products across the intestinal barrier into the systemic circulation, which induces an inflammatory response in the liver and contributes to steatohepatitis. We investigated the roles of the intestinal mucus layer, and in particular Muc2, in development of experimental alcohol-associated liver disease in mice. We studied experimental alcohol-induced liver disease, induced by the Tsukamoto-French method (which involves continuous intragastric feeding of an isocaloric diet or alcohol) in wild-type and Muc2−/− mice. Muc2−/− mice showed less alcohol-induced liver injury and steatosis that developed in wild-type mice. Most notably, Muc2−/− mice had significantly lower plasma levels of lipopolysaccharide than wild-type mice after alcohol feeding. In contrast to wild-type mice, Muc2−/− mice were protected from alcohol-associated microbiome changes that are dependent on intestinal mucins. The anti-microbial proteins Reg3b and Reg3g were expressed at significantly higher levels in the jejunum of Muc2−/− mice fed the isocaloric diet or alcohol, compared with wild-type mice. Consequently, Muc2−/− mice showed increased killing of commensal bacteria and prevented intestinal bacterial overgrowth. Conclusion: Muc2−/− mice are protected from intestinal bacterial overgrowth and dysbiosis in response to alcohol feeding. Subsequently, lower amounts of bacterial products such as endotoxin translocate into the systemic circulation, decreasing liver disease. PMID:23408358

DNA prime–protein boost increased the titer, avidity and persistence of anti-Aβ antibodies in wild-type mice

PubMed Central

Davtyan, H; Mkrtichyan, M; Movsesyan, N; Petrushina, I; Mamikonyan, G; Cribbs, DH; Agadjanyan, MG; Ghochikyan, A

2010-01-01

Recently, we reported that a DNA vaccine, composed of three copies of a self B cell epitope of amyloid-β (Aβ42) and the foreign T-cell epitope, Pan DR epitope (PADRE), generated strong anti-Aβ immune responses in wild-type and amyloid precursor protein transgenic animals. Although DNA vaccines have several advantages over peptide–protein vaccines, they induce lower immune responses in large animals and humans compared with those in mice. The focus of this study was to further enhance anti-Aβ11 immune responses by developing an improved DNA vaccination protocol of the prime–boost regimen, in which the priming step would use DNA and the boosting step would use recombinant protein. Accordingly, we generated DNA and recombinant protein-based epitope vaccines and showed that priming with DNA followed by boosting with a homologous recombinant protein vaccine significantly increases the anti-Aβ antibody responses and do not change the immunoglobulin G1 (IgG1) profile of humoral immune responses. Furthermore, the antibodies generated by this prime–boost regimen were long-lasting and possessed a higher avidity for binding with an Aβ42 peptide. Thus, we showed that a heterologous prime–boost regimen could be an effective protocol for developing a potent Alzheimer’s disease (AD) vaccine. PMID:19865176

Differential cytokine expression in skin graft healing in inducible nitric oxide synthase knockout mice.

PubMed

Most, D; Efron, D T; Shi, H P; Tantry, U S; Barbul, A

2001-10-01

Inducible nitric oxide synthase (iNOS) and its product, nitric oxide, have been shown to play important roles in wound biology. The present study was performed to investigate the role of iNOS in modulating the cytokine cascade during the complex process of skin graft wound healing.Fifteen iNOS-knockout mice and 15 wild-type C57BL/6J mice were subjected to autogenous 1-cm2 intrascapular full-thickness skin grafts. Three animals in each group were killed on postoperative days 3, 5, 7, 10, and 14. Specimens were then analyzed using nonisotopic in situ hybridization versus mRNA of tumor growth factor-beta1, vascular endothelial growth factor, iNOS, endothelial nitric oxide synthase (eNOS), tumor necrosis factor-alpha, and basic fibroblast growth factor, as well as positive and negative control probes. Positive cells in both grafts and wound beds were counted using a Leica microgrid. Scar thickness was measured with a Leica micrometer. Data were analyzed using the unpaired Student's t test. Expression of iNOS was 2- to 4-fold higher in knockout mice than in wild-type mice on postoperative days 5, 7, and 14. Expression of eNOS was 2- to 2.5-fold higher in knockout mice than in wild-type mice on postoperative days 5 and 7. Tumor necrosis factor-alpha expression was 2- to 7-fold higher in knockout mice than in wild-type mice on all postoperative days. In contrast, expression levels of angiogenic/fibrogenic cytokines (vascular endothelial growth factor, basis fibroblast growth factor, and tumor growth factor-beta1) were 2.5- to 4-fold higher in wild-type mice than in knockout mice. Scars were 1.5- to 2.5-fold thicker in knockout mice than in wild-type mice at all time points. All of the above results represent statistically significant differences (p < 0.05). Significantly different patterns of cytokine expression were seen in knockout and wild-type mice. Although the scar layer was thicker in knockout mice, it showed much greater infiltration with inflammatory cells. These

Salivary Gland Hypofunction in tyrosylprotein sulfotransferase-2 Knockout Mice Is Due to Primary Hypothyroidism

PubMed Central

Westmuckett, Andrew D.; Siefert, Joseph C.; Tesiram, Yasvir A.; Pinson, David M.; Moore, Kevin L.

2013-01-01

Background Protein-tyrosine sulfation is a post-translational modification of an unknown number of secreted and membrane proteins mediated by two known Golgi tyrosylprotein sulfotransferases (TPST-1 and TPST-2). We reported that Tpst2-/- mice have mild-moderate primary hypothyroidism, whereas Tpst1-/- mice are euthyroid. While using magnetic resonance imaging (MRI) to look at the thyroid gland we noticed that the salivary glands in Tpst2-/- mice appeared smaller than in wild type mice. This prompted a detailed analysis to compare salivary gland structure and function in wild type, Tpst1-/-, and Tpst2 -/- mice. Methodology/Principal Findings Quantitative MRI imaging documented that salivary glands in Tpst2-/- females were ≈ 30% smaller than wild type or Tpst1-/- mice and that the granular convoluted tubules in Tpst2-/- submandibular glands were less prominent and were almost completely devoid of exocrine secretory granules compared to glands from wild type or Tpst1-/- mice. In addition, pilocarpine–induced salivary flow and salivary α-amylase activity in Tpst2-/- mice of both sexes was substantially lower than in wild type and Tpst1-/- mice. Anti-sulfotyrosine Western blots of salivary gland extracts and saliva showed no differences between wild type, Tpst1-/-, and Tpst2-/- mice, suggesting that the salivary gland hypofunction is due to factor(s) extrinsic to the salivary glands. Finally, we found that all indicators of hypothyroidism (serum T4, body weight) and salivary gland hypofunction (salivary flow, salivary α-amylase activity, histological changes) were restored to normal or near normal by thyroid hormone supplementation. Conclusions/Significance Our findings conclusively demonstrate that low body weight and salivary gland hypofunction in Tpst2-/- mice is due solely to primary hypothyroidism. PMID:23951251

Wild rodents and shrews are natural hosts of Staphylococcus aureus.

PubMed

Mrochen, Daniel M; Schulz, Daniel; Fischer, Stefan; Jeske, Kathrin; El Gohary, Heba; Reil, Daniela; Imholt, Christian; Trübe, Patricia; Suchomel, Josef; Tricaud, Emilie; Jacob, Jens; Heroldová, Marta; Bröker, Barbara M; Strommenger, Birgit; Walther, Birgit; Ulrich, Rainer G; Holtfreter, Silva

2017-09-22

Laboratory mice are the most commonly used animal model for Staphylococcus aureus infection studies. We have previously shown that laboratory mice from global vendors are frequently colonized with S. aureus. Laboratory mice originate from wild house mice. Hence, we investigated whether wild rodents, including house mice, as well as shrews are naturally colonized with S. aureus and whether S. aureus adapts to the wild animal host. 295 animals of ten different species were caught in different locations over four years (2012-2015) in Germany, France and the Czech Republic. 45 animals were positive for S. aureus (15.3%). Three animals were co-colonized with two different isolates, resulting in 48 S. aureus isolates in total. Positive animals were found in Germany and the Czech Republic in each studied year. The S. aureus isolates belonged to ten different spa types, which grouped into six lineages (clonal complex (CC) 49, CC88, CC130, CC1956, sequence type (ST) 890, ST3033). CC49 isolates were most abundant (17/48, 35.4%), followed by CC1956 (14/48, 29.2%) and ST890 (9/48, 18.8%). The wild animal isolates lacked certain properties that are common among human isolates, e.g., a phage-encoded immune evasion cluster, superantigen genes on mobile genetic elements and antibiotic resistance genes, which suggests long-term adaptation to the wild animal host. One CC130 isolate contained the mecC gene, implying wild rodents might be both reservoir and vector for methicillin-resistant S. aureus. In conclusion, we demonstrated that wild rodents and shrews are naturally colonized with S. aureus, and that those S. aureus isolates show signs of host adaptation. Copyright © 2017 The Authors. Published by Elsevier GmbH.. All rights reserved.

Interferon-Induced Ifit2/ISG54 Protects Mice from Lethal VSV Neuropathogenesis

PubMed Central

Fensterl, Volker; Wetzel, Jaime L.; Ramachandran, Srividya; Ogino, Tomoaki; Stohlman, Stephen A.; Bergmann, Cornelia C.; Diamond, Michael S.; Virgin, Herbert W.; Sen, Ganes C.

2012-01-01

Interferon protects mice from vesicular stomatitis virus (VSV) infection and pathogenesis; however, it is not known which of the numerous interferon-stimulated genes (ISG) mediate the antiviral effect. A prominent family of ISGs is the interferon-induced with tetratricopeptide repeats (Ifit) genes comprising three members in mice, Ifit1/ISG56, Ifit2/ISG54 and Ifit3/ISG49. Intranasal infection with a low dose of VSV is not lethal to wild-type mice and all three Ifit genes are induced in the central nervous system of the infected mice. We tested their potential contributions to the observed protection of wild-type mice from VSV pathogenesis, by taking advantage of the newly generated knockout mice lacking either Ifit2 or Ifit1. We observed that in Ifit2 knockout (Ifit2 −/−) mice, intranasal VSV infection was uniformly lethal and death was preceded by neurological signs, such as ataxia and hind limb paralysis. In contrast, wild-type and Ifit1 −/− mice were highly protected and survived without developing such disease. However, when VSV was injected intracranially, virus replication and survival were not significantly different between wild-type and Ifit2−/− mice. When administered intranasally, VSV entered the central nervous system through the olfactory bulbs, where it replicated equivalently in wild-type and Ifit2 −/− mice and induced interferon-β. However, as the infection spread to other regions of the brain, VSV titers rose several hundred folds higher in Ifit2 −/− mice as compared to wild-type mice. This was not caused by a broadened cell tropism in the brains of Ifit2 −/− mice, where VSV still replicated selectively in neurons. Surprisingly, this advantage for VSV replication in the brains of Ifit2−/− mice was not observed in other organs, such as lung and liver. Pathogenesis by another neurotropic RNA virus, encephalomyocarditis virus, was not enhanced in the brains of Ifit2 −/− mice. Our study provides a clear demonstration of

Reduced bone mass and muscle strength in male 5α-reductase type 1 inactivated mice.

PubMed

Windahl, Sara H; Andersson, Niklas; Börjesson, Anna E; Swanson, Charlotte; Svensson, Johan; Movérare-Skrtic, Sofia; Sjögren, Klara; Shao, Ruijin; Lagerquist, Marie K; Ohlsson, Claes

2011-01-01

Androgens are important regulators of bone mass but the relative importance of testosterone (T) versus dihydrotestosterone (DHT) for the activation of the androgen receptor (AR) in bone is unknown. 5α-reductase is responsible for the irreversible conversion of T to the more potent AR activator DHT. There are two well established isoenzymes of 5α-reductase (type 1 and type 2), encoded by separate genes (Srd5a1 and Srd5a2). 5α-reductase type 2 is predominantly expressed in male reproductive tissues whereas 5α-reductase type 1 is highly expressed in liver and moderately expressed in several other tissues including bone. The aim of the present study was to investigate the role of 5α-reductase type 1 for bone mass using Srd5a1⁻/⁻ mice. Four-month-old male Srd5a1⁻/⁻ mice had reduced trabecular bone mineral density (-36%, p<0.05) and cortical bone mineral content (-15%, p<0.05) but unchanged serum androgen levels compared with wild type (WT) mice. The cortical bone dimensions were reduced in the male Srd5a1⁻/⁻ mice as a result of a reduced cortical periosteal circumference compared with WT mice. T treatment increased the cortical periosteal circumference (p<0.05) in orchidectomized WT mice but not in orchidectomized Srd5a1⁻/⁻ mice. Male Srd5a1⁻/⁻ mice demonstrated a reduced forelimb muscle grip strength compared with WT mice (p<0.05). Female Srd5a1⁻/⁻ mice had slightly increased cortical bone mass associated with elevated circulating levels of androgens. In conclusion, 5α-reductase type 1 inactivated male mice have reduced bone mass and forelimb muscle grip strength and we propose that these effects are due to lack of 5α-reductase type 1 expression in bone and muscle. In contrast, the increased cortical bone mass in female Srd5a1⁻/⁻ mice, is an indirect effect mediated by elevated circulating androgen levels.

Reduced Bone Mass and Muscle Strength in Male 5α-Reductase Type 1 Inactivated Mice

PubMed Central

Windahl, Sara H.; Andersson, Niklas; Börjesson, Anna E.; Swanson, Charlotte; Svensson, Johan; Movérare-Skrtic, Sofia; Sjögren, Klara; Shao, Ruijin; Lagerquist, Marie K.; Ohlsson, Claes

2011-01-01

Androgens are important regulators of bone mass but the relative importance of testosterone (T) versus dihydrotestosterone (DHT) for the activation of the androgen receptor (AR) in bone is unknown. 5α-reductase is responsible for the irreversible conversion of T to the more potent AR activator DHT. There are two well established isoenzymes of 5α-reductase (type 1 and type 2), encoded by separate genes (Srd5a1 and Srd5a2). 5α-reductase type 2 is predominantly expressed in male reproductive tissues whereas 5α-reductase type 1 is highly expressed in liver and moderately expressed in several other tissues including bone. The aim of the present study was to investigate the role of 5α-reductase type 1 for bone mass using Srd5a1−/− mice. Four-month-old male Srd5a1 −/− mice had reduced trabecular bone mineral density (−36%, p<0.05) and cortical bone mineral content (−15%, p<0.05) but unchanged serum androgen levels compared with wild type (WT) mice. The cortical bone dimensions were reduced in the male Srd5a1 −/− mice as a result of a reduced cortical periosteal circumference compared with WT mice. T treatment increased the cortical periosteal circumference (p<0.05) in orchidectomized WT mice but not in orchidectomized Srd5a1 −/− mice. Male Srd5a1 −/− mice demonstrated a reduced forelimb muscle grip strength compared with WT mice (p<0.05). Female Srd5a1 −/− mice had slightly increased cortical bone mass associated with elevated circulating levels of androgens. In conclusion, 5α-reductase type 1 inactivated male mice have reduced bone mass and forelimb muscle grip strength and we propose that these effects are due to lack of 5α-reductase type 1 expression in bone and muscle. In contrast, the increased cortical bone mass in female Srd5a1 −/− mice, is an indirect effect mediated by elevated circulating androgen levels. PMID:21731732

Immune mechanisms induced by an HSV-1 mutant strain: Discrepancy analysis of the immune system gene profile in comparison with a wild-type strain.

PubMed

Zhang, Xiaolong; Jiang, Quanlong; Xu, Xingli; Wang, Yongrong; Liu, Lei; Lian, Yaru; Li, Hao; Wang, Lichun; Zhang, Ying; Jiang, Guorun; Zeng, Jieyuan; Zhang, Han; Han, Jing-Dong Jackie; Li, Qihan

2018-04-25

Herpes simplex virus is a prevalent pathogen of humans of various age groups. The fact that no prophylactic or therapeutic vaccine is currently available suggests a significant need to further investigate the immune mechanisms induced by the virus and various vaccine candidates. We previously generated an HSV-1 mutant strain, M3, with partial deletions in ul7, ul41 and LAT that produced an attenuated phenotype in mice. In the present study, we performed a comparative analysis to characterize the immune responses induced by M3 versus wild-type HSV-1 in a mouse model. Infection with wild-type HSV-1 triggered an inflammatory-dominated response and adaptive immunity suppression and was accompanied by severe pathological damage. In contrast, infection with M3 induced a systematic immune response involving full activation of both innate and adaptive immunity and was accompanied by no obvious pathological changes. Furthermore, the immune response induced by M3 protected mice from lethal challenge with wild-type strains of HSV-1 and restrained virus proliferation and impaired latency. These data are useful for further HSV-1 vaccine development using a mutant strain construction strategy. Copyright © 2018 Elsevier Ltd. All rights reserved.

Resistance to collagen-induced arthritis in SHPS-1 mutant mice

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

Okuzawa, Chie; Kaneko, Yoriaki; Murata, Yoji

SHPS-1 is a transmembrane protein that binds the protein tyrosine phosphatases SHP-1 and SHP-2 through its cytoplasmic region and is abundantly expressed on dendritic cells and macrophages. Here we show that mice expressing a mutant form of SHPS-1 fail to develop type-II collagen (CII)-induced arthritis (CIA), a model for rheumatoid arthritis in humans. Histological examinations of the arthritic paws from immunized wild-type mice revealed that cartilage was destroyed in association with marked mononuclear cell infiltration, while only mild cell infiltration was observed in immunized SHPS-1 mutant mice. Consistently, the serum levels of both IgG and IgG2a specific to CII andmore » of IL-1{beta} in immunized SHPS-1 mutant mice were markedly reduced compared with those apparent for wild-type mice. The CII-induced proliferation of, and production of cytokines by, T cells from immunized SHPS-1 mutant mice were reduced compared to wild-type cells. These results suggest that SHPS-1 is essential for development of CIA.« less

Mechanical response of wild-type and Alport murine lens capsules during osmotic swelling.

PubMed

Gyoneva, Lazarina; Segal, Yoav; Dorfman, Kevin D; Barocas, Victor H

2013-08-01

The mechanical support of basement membranes, such as the lens capsule, is believed to arise from one of their main constituents - collagen IV. The basement membranes of the lens, kidney, and ear normally contain two different types of collagen IV networks, referred to as the major and minor chain networks. In Alport syndrome, a mutation in one of the minor chain COL4 genes leads to the absence of the minor chain network, causing life-threatening disturbances. We hypothesized that the absence of the minor chain network increases basement membrane distensibility, as measured in wild-type (n = 25) and Alport syndrome (n = 21) mice using the lens capsule as a model. Osmotic swelling experiments revealed direction-dependent changes. As a reflection of lens capsule properties, Alport lenses strained significantly more than wild-type lenses in the anterior-posterior direction, i.e. along their thickness, but not in the equatorial direction (p = 0.03 and p = 0.08, respectively). This is consistent with clinical data: Alport patients develop conical protrusions on the anterior and posterior lenticular poles. There was no evidence of significant change in total amount of collagen between Alport and wild-type lenses (p = 0.6). The observed differences in distensibility could indicate that the major chain network alone cannot fully compensate for the absence of the more highly cross-linked minor chain network, which is believed to be stronger, more stable, and resistant to deformation. The addition of mechanical information on Alport syndrome to the currently available biological data provides a fuller picture into the progression of the disease. Copyright © 2013 Elsevier Ltd. All rights reserved.

Bidirectional modulation of fear extinction by mediodorsal thalamic firing in mice.

PubMed

Lee, Sukchan; Ahmed, Touqeer; Lee, Soojung; Kim, Huisu; Choi, Sukwoo; Kim, Duk-Soo; Kim, Sang Jeong; Cho, Jeiwon; Shin, Hee-Sup

2011-12-25

The mediodorsal thalamic nucleus has been implicated in the control of memory processes. However, the underlying neural mechanism remains unclear. Here we provide evidence for bidirectional modulation of fear extinction by the mediodorsal thalamic nucleus. Mice with a knockout or mediodorsal thalamic nucleus-specific knockdown of phospholipase C β4 exhibited impaired fear extinction. Mutant mediodorsal thalamic nucleus neurons in slices showed enhanced burst firing accompanied by increased T-type Ca(2+) currents; blocking of T channels in vivo rescued the fear extinction. Tetrode recordings in freely moving mice revealed that, during extinction, the single-spike (tonic) frequency of mediodorsal thalamic nucleus neurons increased in wild-type mice, but was static in mutant mice. Furthermore, tonic-evoking microstimulations of the mediodorsal thalamic nucleus, contemporaneous with the extinction tones, rescued fear extinction in mutant mice and facilitated it in wild-type mice. In contrast, burst-evoking microstimulation suppressed extinction in wild-type mice, mimicking the mutation. These results suggest that the firing mode of the mediodorsal thalamic nucleus is critical for the modulation of fear extinction.

Dried bonito dashi: taste qualities evaluated using conditioned taste aversion methods in wild-type and T1R1 knockout mice.

PubMed

Delay, Eugene R; Kondoh, Takashi

2015-02-01

The primary taste of dried bonito dashi is thought to be umami, elicited by inosine 5'-monphosphate (IMP) and L-amino acids. The present study compared the taste qualities of 25% dashi with 5 basic tastes and amino acids using conditioned taste aversion methods. Although wild-type C57BL/6J mice with compromised olfactory systems generalized an aversion of dashi to all 5 basic tastes, generalization was greater to sucrose (sweet), citric acid (sour), and quinine (bitter) than to NaCl (salty) or monosodium L-glutamate (umami) with amiloride. At neutral pH (6.5-6.9), the aversion generalized to l-histidine, L-alanine, L-proline, glycine, L-aspartic acid, L-serine, and monosodium L-glutamate, all mixed with IMP. Lowering pH of the test solutions to 5.7-5.8 (matching dashi) with HCl decreased generalization to some amino acids. However, adding lactic acid to test solutions with the same pH increased generalization to 5'-inosine monophosphate, L-leucine, L-phenylalanine, L-valine, L-arginine, and taurine but eliminated generalization to L-histidine. T1R1 knockout mice readily learned the aversion to dashi and generalized the aversion to sucrose, citric acid, and quinine but not to NaCl, glutamate, or any amino acid. These results suggest that dashi elicits a complex taste in mice that is more than umami, and deleting T1R1 receptor altered but did not eliminate their ability to taste dashi. In addition, lactic acid may alter or modulate taste transduction or cell-to-cell signaling. © The Author 2015. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

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.

Relatively high rates of G:C → A:T transitions at CpG sites were observed in certain epithelial tissues including pancreas and submaxillary gland of adult big blue® mice.

PubMed

Prtenjaca, Anita; Tarnowski, Heather E; Marr, Alison M; Heney, Melanie A; Creamer, Laura; Sathiamoorthy, Sarmitha; Hill, Kathleen A

2014-01-01

With few exceptions, spontaneous mutation frequency and pattern are similar across tissue types and relatively constant in young to middle adulthood in wild type mice. Underrepresented in surveys of spontaneous mutations across murine tissues is the diversity of epithelial tissues. For the first time, spontaneous mutations were detected in pancreas and submaxillary gland and compared with kidney, lung, and male germ cells from five adult male Big Blue® mice. Mutation load was assessed quantitatively through measurement of mutant and mutation frequency and qualitatively through identification of mutations and characterization of recurrent mutations, multiple mutations, mutation pattern, and mutation spectrum. A total of 9.6 million plaque forming units were screened, 226 mutants were collected, and 196 independent mutations were identified. Four novel mutations were discovered. Spontaneous mutation frequency was low in pancreas and high in the submaxillary gland. The submaxillary gland had multiple recurrent mutations in each of the mice and one mutant had two independent mutations. Mutation patterns for epithelial tissues differed from that observed in male germ cells with a striking bias for G:C to A:T transitions at CpG sites. A comprehensive review of lacI spontaneous mutation patterns in young adult mice and rats identified additional examples of this mutational bias. An overarching observation about spontaneous mutation frequency in adult tissues of the mouse remains one of stability. A repeated observation in certain epithelial tissues is a higher rate of G:C to A:T transitions at CpG sites and the underlying mechanisms for this bias are not known. Copyright © 2013 Wiley Periodicals, Inc.

Multiple adaptive amino acid substitutions increase the virulence of a wild waterfowl-origin reassortant H5N8 avian influenza virus in mice.

PubMed

Yu, Zhijun; Cheng, Kaihui; Sun, Weiyang; Zhang, Xinghai; Xia, Xianzhu; Gao, Yuwei

2018-01-15

A novel H5N8 highly pathogenic avian influenza virus (HPAIV) caused poultry outbreaks in the Republic of Korea in 2014. The novel H5N8 HPAIV has spread to Asia, Europe, and North America and caused great public concern from then on. Here, we generated mouse-adapted variants of a wild waterfowl-origin H5N8 HPAIV to identify adaptive mutants that confer enhanced pathogenicity in mammals. The mouse lethal doses (MLD 50 ) of the mouse-adapted variants were reduced 31623-fold compared to the wild-type (WT) virus. Mouse-adapted variants displayed enhanced replication in vitro and in vivo, and expanded tissue tropism in mice. Sequence analysis revealed four amino acid substitutions in the PB2 (E627K), PA (F35S), HA (R227H), and NA (I462V) proteins. These data suggest that multiple amino acid substitutions collaboratively increase the virulence of a wild bird-origin reassortant H5N8 HPAIV and cause severe disease in mice. Copyright © 2017 Elsevier B.V. All rights reserved.

The Intrauterine and Nursing Period Is a Window of Susceptibility for Development of Obesity and Intestinal Tumorigenesis by a High Fat Diet in Min/+ Mice as Adults

PubMed Central

Ngo, Ha Thi; Hetland, Ragna Bogen; Steffensen, Inger-Lise

2015-01-01

We studied how obesogenic conditions during various life periods affected obesity and intestinal tumorigenesis in adult C57BL/6J-Min (multiple intestinal neoplasia)/+ mice. The mice were given a 10% fat diet throughout life (negative control) or a 45% fat diet in utero, during nursing, during both in utero and nursing, during adult life, or during their whole life-span, and terminated at 11 weeks for tumorigenesis (Min/+) or 23 weeks for obesogenic effect (wild-type). Body weight at 11 weeks was increased after a 45% fat diet during nursing, during both in utero and nursing, and throughout life, but had normalized at 23 weeks. In the glucose tolerance test, the early exposure to a 45% fat diet in utero, during nursing, or during both in utero and nursing, did not affect blood glucose, whereas a 45% fat diet given to adults or throughout life did. However, a 45% fat diet during nursing or during in utero and nursing increased the number of small intestinal tumors. So did exposures to a 45% fat diet in adult life or throughout life, but without increasing the tumor numbers further. The intrauterine and nursing period is a window of susceptibility for dietary fat-induced obesity and intestinal tumor development. PMID:25874125

Laboratory and wild-derived mice with multiple loci for production of xenotropic murine leukemia virus.

PubMed

Kozak, C A; Hartley, J W; Morse, H C

1984-07-01

Mendelian segregation analysis was used to define genetic loci for the induction of infectious xenotropic murine leukemia virus in several laboratory and wild-derived mice. MA/My mice contain two loci for xenotropic virus inducibility, one of which, Bxv -1, is the only induction locus carried by five other inbred strains. The second, novel MA/My locus, designated Mxv -1, is unlinked to Bxv -1 and shows a lower efficiency of virus induction. The NZB mouse carries two induction loci; both are distinct from Bxv -1 since neither is linked to the Pep-3 locus on chromosome 1. Finally, one partially inbred strain derived from the wild Japanese mouse, Mus musculus molossinus, carries multiple (at least three) unlinked loci for induction of xenotropic virus. Although it is probable that inbred strains inherited xenotropic virus inducibility from Japanese mice, our data suggest that none of the induction loci carried by this particular M. m. molossinus strain are allelic with Bxv -1.

Laboratory and wild-derived mice with multiple loci for production of xenotropic murine leukemia virus.

PubMed Central

Kozak, C A; Hartley, J W; Morse, H C

1984-01-01

Mendelian segregation analysis was used to define genetic loci for the induction of infectious xenotropic murine leukemia virus in several laboratory and wild-derived mice. MA/My mice contain two loci for xenotropic virus inducibility, one of which, Bxv -1, is the only induction locus carried by five other inbred strains. The second, novel MA/My locus, designated Mxv -1, is unlinked to Bxv -1 and shows a lower efficiency of virus induction. The NZB mouse carries two induction loci; both are distinct from Bxv -1 since neither is linked to the Pep-3 locus on chromosome 1. Finally, one partially inbred strain derived from the wild Japanese mouse, Mus musculus molossinus, carries multiple (at least three) unlinked loci for induction of xenotropic virus. Although it is probable that inbred strains inherited xenotropic virus inducibility from Japanese mice, our data suggest that none of the induction loci carried by this particular M. m. molossinus strain are allelic with Bxv -1. PMID:6328046

Orthotopic transplantation of LH receptor knockout and wild-type ovaries.

PubMed

Chudgar, Daksha; Lei, Zhenmin; Rao, Ch V

2005-10-07

Luteinizing hormone (LH) receptor knockout animals have an ovarian failure due to an arrest in folliculogenesis at the antral stage. As a result, the animals have an infertility phenotype. The present study was undertaken to determine whether this phenotype could be reversed by orthotopic transplantation of wild-type ovaries. The results revealed that transplanting wild-type ovaries into null animals did not result in resumption of estrus cycles. Although the number of different types of follicles increased, none progressed to ovulation. The serum hormone profiles improved, reflecting the ovarian changes. The wild-type animals with null ovaries also failed to cycle and their ovaries and serum hormone levels were more like null animals with their own ovaries. Although the lack of rescue of null ovaries placed into wild-type animals was predicted, the failure of wild-type ovaries placed in null animals was not, which could be due to chronic exposure of transplanted tissue to high circulating LH levels and also possibly due to altered internal milieu in null animals. These findings may have implications for potential future considerations of grafting normal donor ovaries into women who have an ovarian failure resulting from inactivating LH receptor mutations.

CDKL5 deficiency entails sleep apneas in mice.

PubMed

Lo Martire, Viviana; Alvente, Sara; Bastianini, Stefano; Berteotti, Chiara; Silvani, Alessandro; Valli, Alice; Viggiano, Rocchina; Ciani, Elisabetta; Zoccoli, Giovanna

2017-08-01

A recently discovered neurodevelopmental disorder caused by the mutation of the cyclin-dependent kinase-like 5 gene (CDKL5) entails complex autistic-like behaviours similar to Rett syndrome, but its impact upon physiological functions remains largely unexplored. Sleep-disordered breathing is common and potentially life-threatening in patients with Rett syndrome; however, evidence is limited in children with CDKL5 disorder, and is lacking altogether in adults. The aim of this study was to test whether the breathing pattern during sleep differs between adult Cdkl5 knockout (Cdkl5-KO) and wild-type (WT) mice. Using whole-body plethysmography, sleep and breathing were recorded non-invasively for 8 h during the light period. Sleep apneas occurred more frequently in Cdkl5-KO than in WT mice. A receiver operating characteristic (ROC) analysis discriminated Cdkl5-KO significantly from WT mice based on sleep apnea occurrence. These data demonstrate that sleep apneas are a core feature of CDKL5 disorder and a respiratory biomarker of CDKL5 deficiency in mice, and suggest that sleep-disordered breathing should be evaluated routinely in CDKL5 patients. © 2017 European Sleep Research Society.

Human thrombomodulin knock-in mice reveal differential effects of human thrombomodulin on thrombosis and atherosclerosis.

PubMed

Raife, Thomas J; Dwyre, Denis M; Stevens, Jeff W; Erger, Rochelle A; Leo, Lorie; Wilson, Katina M; Fernández, Jose A; Wilder, Jennifer; Kim, Hyung-Suk; Griffin, John H; Maeda, Nobuyo; Lentz, Steven R

2011-11-01

We sought to develop a murine model to examine the antithrombotic and antiinflammatory functions of human thrombomodulin in vivo. Knock-in mice that express human thrombomodulin from the murine thrombomodulin gene locus were generated. Compared with wild-type mice, human thrombomodulin knock-in mice exhibited decreased protein C activation in the aorta (P<0.01) and lung (P<0.001). Activation of endogenous protein C following infusion of thrombin was decreased by 90% in knock-in mice compared with wild-type mice (P<0.05). Carotid artery thrombosis induced by photochemical injury occurred more rapidly in knock-in mice (12±3 minutes) than in wild-type mice (31±6 minutes; P<0.05). No differences in serum cytokine levels were detected between knock-in and wild-type mice after injection of endotoxin. When crossed with apolipoprotein E-deficient mice and fed a Western diet, knock-in mice had a further decrease in protein C activation but did not exhibit increased atherosclerosis. Expression of human thrombomodulin in place of murine thrombomodulin produces viable mice with a prothrombotic phenotype but unaltered responses to systemic inflammatory or atherogenic stimuli. This humanized animal model will be useful for investigating the function of human thrombomodulin under pathophysiological conditions in vivo.

Ablation of huntingtin in adult neurons is nondeleterious but its depletion in young mice causes acute pancreatitis

PubMed Central

Wang, Guohao; Liu, Xudong; Gaertig, Marta A.; Li, Shihua; Li, Xiao-Jiang

2016-01-01

The Huntington’s disease (HD) protein, huntingtin (HTT), is essential for early development. Because suppressing the expression of mutant HTT is an important approach to treat the disease, we must first understand the normal function of Htt in adults versus younger animals. Using inducible Htt knockout mice, we found that Htt depletion does not lead to adult neurodegeneration or animal death at >4 mo of age, which was also verified by selectively depleting Htt in neurons. On the other hand, young Htt KO mice die at 2 mo of age of acute pancreatitis due to the degeneration of pancreatic acinar cells. Importantly, Htt interacts with the trypsin inhibitor, serine protease inhibitor Kazal-type 3 (Spink3), to inhibit activation of digestive enzymes in acinar cells in young mice, and transgenic HTT can rescue the early death of Htt KO mice. These findings point out age- and cell type-dependent vital functions of Htt and the safety of knocking down neuronal Htt expression in adult brains as a treatment. PMID:26951659

Critical role of toll-like receptor 9 in morphine and Mycobacterium tuberculosis-Induced apoptosis in mice.

PubMed

Chen, Lin; Shi, Wanliang; Li, Hui; Sun, Xiuli; Fan, Xionglin; Lesage, Gene; Li, Hui; Li, Yi; Zhang, Yi; Zhang, Xiumei; Zhang, Ying; Yin, Deling

2010-02-19

Although it is established that opioid and Mycobacterium tuberculosis are both public health problems, the mechanisms by which they affect lung functions remain elusive. We report here that mice subjected to chronic morphine administration and M. tuberculosis infection exhibited significant apoptosis in the lung in wild type mice as demonstrated by the terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end labeling assay. Morphine and M. tuberculosis significantly induced the expression of Toll-like receptor 9 (TLR9), a key mediator of innate immunity and inflammation. Interestingly, deficiency in TLR9 significantly inhibited the morphine and M. tuberculosis induced apoptosis in the lung. In addition, chronic morphine treatment and M. tuberculosis infection enhanced the levels of cytokines (TNF-alpha, IL-1beta, and IL-6) in wild type mice, but not in TLR9 knockout (KO) mice. The bacterial load was much lower in TLR9 KO mice compared with that in wild type mice following morphine and M. tuberculosis treatment. Morphine alone did not alter the bacterial load in either wild type or TLR9 KO mice. Moreover, administration of morphine and M. tuberculosis decreased the levels of phosphorylation of Akt and GSK3beta in the wild type mice, but not in TLR9 KO mice, suggesting an involvement of Akt/GSK3beta in morphine and M. tuberculosis-mediated TLR9 signaling. Furthermore, administration of morphine and M. tuberculosis caused a dramatic decrease in Bcl-2 level but increase in Bax level in wild type mice, but not in TLR9 KO mice, indicating a role of Bcl-2 family in TLR9-mediated apoptosis in the lung following morphine and M. tuberculosis administration. These data reveal a role for TLR9 in the immune response to opioids during M. tuberculosis infection.

Wild-Type and Non-Wild-Type Mycobacterium tuberculosis MIC Distributions for the Novel Fluoroquinolone Antofloxacin Compared with Those for Ofloxacin, Levofloxacin, and Moxifloxacin

PubMed Central

Yu, Xia; Wang, Guirong; Chen, Suting; Wei, Guomei; Shang, Yuanyuan; Dong, Lingling; Schön, Thomas; Moradigaravand, Danesh; Peacock, Sharon J.

2016-01-01

Antofloxacin (AFX) is a novel fluoroquinolone that has been approved in China for the treatment of infections caused by a variety of bacterial species. We investigated whether it could be repurposed for the treatment of tuberculosis by studying its in vitro activity. We determined the wild-type and non-wild-type MIC ranges for AFX as well as ofloxacin (OFX), levofloxacin (LFX), and moxifloxacin (MFX), using the microplate alamarBlue assay, of 126 clinical Mycobacterium tuberculosis strains from Beijing, China, of which 48 were OFX resistant on the basis of drug susceptibility testing on Löwenstein-Jensen medium. The MIC distributions were correlated with mutations in the quinolone resistance-determining regions of gyrA (Rv0006) and gyrB (Rv0005). Pharmacokinetic/pharmacodynamic (PK/PD) data for AFX were retrieved from the literature. AFX showed lower MIC levels than OFX but higher MIC levels than LFX and MFX on the basis of the tentative epidemiological cutoff values (ECOFFs) determined in this study. All strains with non-wild-type MICs for AFX harbored known resistance mutations that also resulted in non-wild-type MICs for LFX and MFX. Moreover, our data suggested that the current critical concentration of OFX for Löwenstein-Jensen medium that was recently revised by the World Health Organization might be too high, resulting in the misclassification of phenotypically non-wild-type strains with known resistance mutations as wild type. On the basis of our exploratory PK/PD calculations, the current dose of AFX is unlikely to be optimal for the treatment of tuberculosis, but higher doses could be effective. PMID:27324769

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.

Lyophilized airborne Clostridium botulinum spores as inocula that intestinally colonize antimicrobially pretreated adult mice.

PubMed Central

Sugiyama, H; Prather, J L; Woller, M J

1986-01-01

Adult mice, made susceptible to Clostridium botulinum by feedings of metronidazole, were immobilized with an anesthetic and held for 30 min in isolators in which a fine powder of lyophilized pathogen spores was made airborne. Exposed mice were surface decontaminated before being kept for 2 days in holding isolators. Mice were intestinally colonized by the pathogen. Colonization rates were related to spore numbers (10(4) to 10(7) type A or B) seeded into isolators. PMID:3531017

Use of tissue-specific microRNA to control pathology of wild-type adenovirus without attenuation of its ability to kill cancer cells.

PubMed

Cawood, Ryan; Chen, Hannah H; Carroll, Fionnadh; Bazan-Peregrino, Miriam; van Rooijen, Nico; Seymour, Leonard W

2009-05-01

Replicating viruses have broad applications in biomedicine, notably in cancer virotherapy and in the design of attenuated vaccines; however, uncontrolled virus replication in vulnerable tissues can give pathology and often restricts the use of potent strains. Increased knowledge of tissue-selective microRNA expression now affords the possibility of engineering replicating viruses that are attenuated at the RNA level in sites of potential pathology, but retain wild-type replication activity at sites not expressing the relevant microRNA. To assess the usefulness of this approach for the DNA virus adenovirus, we have engineered a hepatocyte-safe wild-type adenovirus 5 (Ad5), which normally mediates significant toxicity and is potentially lethal in mice. To do this, we have included binding sites for hepatocyte-selective microRNA mir-122 within the 3' UTR of the E1A transcription cassette. Imaging versions of these viruses, produced by fusing E1A with luciferase, showed that inclusion of mir-122 binding sites caused up to 80-fold decreased hepatic expression of E1A following intravenous delivery to mice. Animals administered a ten-times lethal dose of wild-type Ad5 (5x10(10) viral particles/mouse) showed substantial hepatic genome replication and extensive liver pathology, while inclusion of 4 microRNA binding sites decreased replication 50-fold and virtually abrogated liver toxicity. This modified wild-type virus retained full activity within cancer cells and provided a potent, liver-safe oncolytic virus. In addition to providing many potent new viruses for cancer virotherapy, microRNA control of virus replication should provide a new strategy for designing safe attenuated vaccines applied across a broad range of viral diseases.

Recombination within the nonstructural genes of the parvovirus minute virus of mice (MVM) generates functional levels of wild-type NS1, which can be detected in the absence of selective pressure following transfection of nonreplicating plasmids.

PubMed

Pearson, J L; Pintel, D J

2000-03-30

Recombination within the coding region of the nonstructural genes of minute virus of mice (MVM), which generates functional levels of wild-type NS1, was observed in the absence of selective pressure following cotransfection of nonreplicating plasmids. P38 activity was used as a measure of recombinant NS1 production, which, together with direct detection of recombinant-generated products by RT-PCR, allowed an estimation of recombination efficiency. In addition, we show that very low levels of wild-type NS1 were able to significantly transactivate P38. Given that recombination following cotransfection can generate NS1 at these levels, our observations have implications for the study of parvoviral genetics, the construction of recombinant parvoviral vectors for gene therapy applications, and perhaps other systems using cotransfection of plasmids that share homologous sequences. Copyright 2000 Academic Press.

CD38-dependent ADP-ribosyl cyclase activity in developing and adult mouse brain.

PubMed Central

Ceni, Claire; Pochon, Nathalie; Brun, Virginie; Muller-Steffner, Hélène; Andrieux, Annie; Grunwald, Didier; Schuber, Francis; De Waard, Michel; Lund, Frances; Villaz, Michel; Moutin, Marie-Jo

2003-01-01

CD38 is a transmembrane glycoprotein that is expressed in many tissues throughout the body. In addition to its major NAD+-glycohydrolase activity, CD38 is also able to synthesize cyclic ADP-ribose, an endogenous calcium-regulating molecule, from NAD+. In the present study, we have compared ADP-ribosyl cyclase and NAD+-glycohydrolase activities in protein extracts of brains from developing and adult wild-type and Cd38 -/- mice. In extracts from wild-type brain, cyclase activity was detected spectrofluorimetrically, using nicotinamide-guanine dinucleotide as a substrate (GDP-ribosyl cyclase activity), as early as embryonic day 15. The level of cyclase activity was similar in the neonate brain (postnatal day 1) and then increased greatly in the adult brain. Using [14C]NAD+ as a substrate and HPLC analysis, we found that ADP-ribose is the major product formed in the brain at all developmental stages. Under the same experimental conditions, neither NAD+-glycohydrolase nor GDP-ribosyl cyclase activity could be detected in extracts of brains from developing or adult Cd38 -/- mice, demonstrating that CD38 is the predominant constitutive enzyme endowed with these activities in brain at all developmental stages. The activity measurements correlated with the level of CD38 transcripts present in the brains of developing and adult wild-type mice. Using confocal microscopy we showed, in primary cultures of hippocampal cells, that CD38 is expressed by both neurons and glial cells, and is enriched in neuronal perikarya. Intracellular NAD+-glycohydrolase activity was measured in hippocampal cell cultures, and CD38-dependent cyclase activity was higher in brain fractions enriched in intracellular membranes. Taken together, these results lead us to speculate that CD38 might have an intracellular location in neural cells in addition to its plasma membrane location, and may play an important role in intracellular cyclic ADP-ribose-mediated calcium signalling in brain tissue. PMID

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

Impaired ventilatory acclimatization to hypoxia in mice lacking the immediate early gene fos B.

PubMed

Malik, Mohammad T; Peng, Ying-Jie; Kline, David D; Adhikary, Gautam; Prabhakar, Nanduri R

2005-01-15

Earlier studies on cell culture models suggested that immediate early genes (IEGs) play an important role in cellular adaptations to hypoxia. Whether IEGs are also necessary for hypoxic adaptations in intact animals is not known. In the present study we examined the potential importance of fos B, an IEG in ventilatory acclimatization to hypoxia. Experiments were performed on wild type and mutant mice lacking the fos B gene. Ventilation was monitored by whole body plethysmography in awake animals. Baseline ventilation under normoxia, and ventilatory response to acute hypoxia and hypercapnia were comparable between wild type and mutant mice. Hypobaric hypoxia (0.4 atm; 3 days) resulted in a significant elevation of baseline ventilation in wild type but not in mutant mice. Wild type mice exposed to hypobaric hypoxia manifested an enhanced hypoxic ventilatory response compared to pre-hypobaric hypoxia. In contrast, hypobaric hypoxia had no effect on the hypoxic ventilatory response in mutant mice. Hypercapnic ventilatory responses, however, were unaffected by hypobaric hypoxia in both groups of mice. These results suggest that the fos B, an immediate early gene, plays an important role in ventilatory acclimatization to hypoxia in mice.

[Aconitine analogues in wild Aconitum plants: contents toxicity to mice and decrease by boiling].

PubMed

Kasahara, Yoshimasa; Itou, Takeshi; Numazawa, Toshiaki; Wada, Akinobu

2013-01-01

Simultaneous determination of four aconitine analogues (ACs) (AC; aconitine, HA; hypaconitine, JA; jesaconitine, MA; mesaconitine) in leaves and roots of wild Aconitum plants (Aconitum japonicum THUNBERG, Aconitum okuyamae Nakai) was carried out to elucidate the relation between toxicity to mice and ACs content determind by liquid chromatography tandem mass spectrometry. The total amounts of ACs in leaves, roots, petals and nectaries of Aconitum japonicum collected at Sagae-shi Tashiro were 5.9 μg/g, 928.1 μg/g, 46.1 μg/g, and 69.8 μg/g, respectively. Despite the high contents in nectary, commercial honey contained no ACs. Extract of wild Aconitum japonicum roots which contained ACs (2.69 mg/g) was administered to 5 mice orally at 1.0 g/kg (fresh root equivalent), and 2 mice died. On the other hand, 3 of 5 mice died after being given the standard AC (3.0 mg/kg, p.o.). These findings confirmed good coincidence between toxicity and quantitative values. Mice given extract of Aconitum okuyamae root (100 g/kg, p.o.) without ACs showed no toxic symptoms. Residual ACs in Aconitum leaves were examined after boiling. The remaining percentage of ACs in leaves after 0.5 minutes boiling was 31.6%, and the amount in the boiling water was 54.5%. MA is converted into benzoylmesaconine by hydrolysis (by boiling). Therefore food poisoning caused by Aconitum plants is explained by detection of benzoylmesaconine formed during food preparation.

Action potentials and ion conductances in wild-type and CALHM1-knockout type II taste cells

PubMed Central

Saung, Wint Thu; Foskett, J. Kevin

2017-01-01

Taste bud type II cells fire action potentials in response to tastants, triggering nonvesicular ATP release to gustatory neurons via voltage-gated CALHM1-associated ion channels. Whereas CALHM1 regulates mouse cortical neuron excitability, its roles in regulating type II cell excitability are unknown. In this study, we compared membrane conductances and action potentials in single identified TRPM5-GFP-expressing circumvallate papillae type II cells acutely isolated from wild-type (WT) and Calhm1 knockout (KO) mice. The activation kinetics of large voltage-gated outward currents were accelerated in cells from Calhm1 KO mice, and their associated nonselective tail currents, previously shown to be highly correlated with ATP release, were completely absent in Calhm1 KO cells, suggesting that CALHM1 contributes to all of these currents. Calhm1 deletion did not significantly alter resting membrane potential or input resistance, the amplitudes and kinetics of Na+ currents either estimated from action potentials or recorded from steady-state voltage pulses, or action potential threshold, overshoot peak, afterhyperpolarization, and firing frequency. However, Calhm1 deletion reduced the half-widths of action potentials and accelerated the deactivation kinetics of transient outward currents, suggesting that the CALHM1-associated conductance becomes activated during the repolarization phase of action potentials. NEW & NOTEWORTHY CALHM1 is an essential ion channel component of the ATP neurotransmitter release mechanism in type II taste bud cells. Its contribution to type II cell resting membrane properties and excitability is unknown. Nonselective voltage-gated currents, previously associated with ATP release, were absent in cells lacking CALHM1. Calhm1 deletion was without effects on resting membrane properties or voltage-gated Na+ and K+ channels but contributed modestly to the kinetics of action potentials. PMID:28202574

Action potentials and ion conductances in wild-type and CALHM1-knockout type II taste cells.

PubMed

Ma, Zhongming; Saung, Wint Thu; Foskett, J Kevin

2017-05-01

Taste bud type II cells fire action potentials in response to tastants, triggering nonvesicular ATP release to gustatory neurons via voltage-gated CALHM1-associated ion channels. Whereas CALHM1 regulates mouse cortical neuron excitability, its roles in regulating type II cell excitability are unknown. In this study, we compared membrane conductances and action potentials in single identified TRPM5-GFP-expressing circumvallate papillae type II cells acutely isolated from wild-type (WT) and Calhm1 knockout (KO) mice. The activation kinetics of large voltage-gated outward currents were accelerated in cells from Calhm1 KO mice, and their associated nonselective tail currents, previously shown to be highly correlated with ATP release, were completely absent in Calhm1 KO cells, suggesting that CALHM1 contributes to all of these currents. Calhm1 deletion did not significantly alter resting membrane potential or input resistance, the amplitudes and kinetics of Na + currents either estimated from action potentials or recorded from steady-state voltage pulses, or action potential threshold, overshoot peak, afterhyperpolarization, and firing frequency. However, Calhm1 deletion reduced the half-widths of action potentials and accelerated the deactivation kinetics of transient outward currents, suggesting that the CALHM1-associated conductance becomes activated during the repolarization phase of action potentials. NEW & NOTEWORTHY CALHM1 is an essential ion channel component of the ATP neurotransmitter release mechanism in type II taste bud cells. Its contribution to type II cell resting membrane properties and excitability is unknown. Nonselective voltage-gated currents, previously associated with ATP release, were absent in cells lacking CALHM1. Calhm1 deletion was without effects on resting membrane properties or voltage-gated Na + and K + channels but contributed modestly to the kinetics of action potentials. Copyright © 2017 the American Physiological Society.

Microglial response to LPS increases in wild-type mice during aging but diminishes in an Alzheimer's mouse model: Implication of TLR4 signaling in disease progression.

PubMed

Go, Michelle; Kou, Jinghong; Lim, Jeong-Eun; Yang, Junling; Fukuchi, Ken-Ichiro

2016-10-14

Microglia-mediated clearance of amyloid beta-protein (Aβ) via Toll-like receptor 4 (TLR4) signaling may play an important role in the pathogenesis of Alzheimer's disease (AD). However, as the disease progresses, activated microglia appear to become incapable of clearing Aβ deposits. Because repeated exposure to a TLR4 ligand leads to a diminished response of monocytes/macrophages to lipopolysaccharide (LPS) and because aggregated Aβ is a TLR4 ligand, we hypothesize that chronic exposure of microglia to Aβ deposits may induce a state of Toll-like receptor (TLR) signaling dysfunction, leading to decreased Aβ clearance and accelerated disease progression. LPS or phosphate-buffered saline (PBS) was injected into the hippocampus of AD-model (TgAPP/PS1) and wild-type (non-Tg) mice before and after the onset of Aβ deposition, at age 2 and 12 months, respectively. Brain specimens were collected 7 days post-injection and analyzed for microglial activation and Aβ load. While LPS-injected 2-month-old non-Tg mice showed 48-fold and 11-fold greater Iba1 immunoreactivity in the neocortex and hippocampus, respectively, compared with PBS-injected mice, LPS-injected 2-month-old TgAPP/PS1 mice had 61-fold and 13-fold increases in the neocortex and hippocampus, respectively. LPS injection activated microglia more strongly in TgAPP/PS1 mice than in non-Tg mice at 2 months of age. In contrast, at 12 months of age, Iba1 immunoreactivity of microglia was increased 541-fold and 38-fold in the neocortex and hippocampus, respectively, in LPS-injected non-Tg mice and 2.7-fold and 3.3-fold in the neocortex and hippocampus, respectively, in LPS-injected TgAPP/PS1 mice. Surprisingly, LPS injection decreased CD45 immunoreactivity in TgAPP/PS1 mice but increased it in non-Tg mice at 12 months. Although microglia in 12-month-old non-Tg mice showed stronger response to LPS than 2-month-old non-Tg mice, microglia in TgAPP/PS1 mice exhibited diminished immune response to LPS during aging. Our

Estrogen receptor-independent catechol estrogen binding activity: protein binding studies in wild-type, Estrogen receptor-alpha KO, and aromatase KO mice tissues.

PubMed

Philips, Brian J; Ansell, Pete J; Newton, Leslie G; Harada, Nobuhiro; Honda, Shin-Ichiro; Ganjam, Venkataseshu K; Rottinghaus, George E; Welshons, Wade V; Lubahn, Dennis B

2004-06-01

Primary evidence for novel estrogen signaling pathways is based upon well-documented estrogenic responses not inhibited by estrogen receptor antagonists. In addition to 17beta-E2, the catechol estrogen 4-hydroxyestradiol (4OHE2) has been shown to elicit biological responses independent of classical estrogen receptors in estrogen receptor-alpha knockout (ERalphaKO) mice. Consequently, our research was designed to biochemically characterize the protein(s) that could be mediating the biological effects of catechol estrogens using enzymatically synthesized, radiolabeled 4-hydroxyestrone (4OHE1) and 4OHE2. Scatchard analyses identified a single class of high-affinity (K(d) approximately 1.6 nM), saturable cytosolic binding sites in several ERalphaKO estrogen-responsive tissues. Specific catechol estrogen binding was competitively inhibited by unlabeled catechol estrogens, but not by 17beta-E2 or the estrogen receptor antagonist ICI 182,780. Tissue distribution studies indicated significant binding differences both within and among various tissues in wild-type, ERalphaKO, and aromatase knockout female mice. Ligand metabolism experiments revealed extensive metabolism of labeled catechol estrogen, suggesting that catechol estrogen metabolites were responsible for the specific binding. Collectively, our data provide compelling evidence for the interaction of catechol estrogen metabolites with a novel binding protein that exhibits high affinity, specificity, and selective tissue distribution. The extensive biochemical characterization of this binding protein indicates that this protein may be a receptor, and thus may mediate ERalpha/beta-independent effects of catechol estrogens and their metabolites.

Anti-tumor activity of high-dose EGFR tyrosine kinase inhibitor and sequential docetaxel in wild type EGFR non-small cell lung cancer cell nude mouse xenografts

PubMed Central

Tang, Ning; Zhang, Qianqian; Fang, Shu; Han, Xiao; Wang, Zhehai

2017-01-01

Treatment of non-small-cell lung cancer (NSCLC) with wild-type epidermal growth factor receptor (EGFR) is still a challenge. This study explored antitumor activity of high-dose icotinib (an EGFR tyrosine kinase inhibitor) plus sequential docetaxel against wild-type EGFR NSCLC cells-generated nude mouse xenografts. Nude mice were subcutaneously injected with wild-type EGFR NSCLC A549 cells and divided into different groups for 3-week treatment. Tumor xenograft volumes were monitored and recorded, and at the end of experiments, tumor xenografts were removed for Western blot and immunohistochemical analyses. Compared to control groups (negative control, regular-dose icotinib [IcoR], high-dose icotinib [IcoH], and docetaxel [DTX]) and regular icotinib dose (60 mg/kg) with docetaxel, treatment of mice with a high-dose (1200 mg/kg) of icotinib plus sequential docetaxel for 3 weeks (IcoH-DTX) had an additive effect on suppression of tumor xenograft size and volume (P < 0.05). Icotinib-containing treatments markedly reduced phosphorylation of EGFR, mitogen activated protein kinase (MAPK), and protein kinase B (Akt), but only the high-dose icotinib-containing treatments showed an additive effect on CD34 inhibition (P < 0.05), an indication of reduced microvessel density in tumor xenografts. Moreover, high-dose icotinib plus docetaxel had a similar effect on mouse weight loss (a common way to measure adverse reactions in mice), compared to the other treatment combinations. The study indicate that the high dose of icotinib plus sequential docetaxel (IcoH-DTX) have an additive effect on suppressing the growth of wild-type EGFR NSCLC cell nude mouse xenografts, possibly through microvessel density reduction. Future clinical trials are needed to confirm the findings of this study. PMID:27852073

Nuclei pulposi formation from the embryonic notochord occurs normally in GDF-5-deficient mice.

PubMed

Maier, Jennifer A; Harfe, Brian D

2011-11-15

The transition of the mouse embryonic notochord into nuclei pulposi was determined ("fate mapped") in vivo in growth and differentiating factor-5 (GDF-5)-null mice using the Shhcre and R26R alleles. To determine whether abnormal nuclei pulposi formation from the embryonic notochord was responsible for defects present in adult nuclei pulposi of Gdf-5-null mice. The development, maintenance, and degeneration of the intervertebral disc are not understood. Previously, we demonstrated that all cells in the adult nucleus pulposus of normal mice are derived from the embryonic notochord. Gdf-5-null mice have been reported to contain intervertebral discs in which the nucleus pulposus is abnormal. It is currently unclear if disc defects in Gdf-5-null mice arise during the formation of nuclei pulposi from the notochord during embryogenesis or result from progressive postnatal degeneration of nuclei pulposi. Gdf-5 messenger RNA expression was examined in the discs of wild-type embryos by RNA in situ hybridization to determine when and where this gene was expressed. To examine nucleus pulposus formation in Gdf-5-null mice, intervertebral discs in which embryonic notochord cells were marked were analyzed in newborn and 24-week-old mice. Our Gdf-5 messenger RNA in situ experiments determined that this gene is localized to the annulus fibrosus and not the nucleus pulposus in mouse embryos. Notochord fate-mapping experiments revealed that notochord cells in Gdf-5-null mice correctly form nuclei pulposi. Our data suggest that the defects reported in the nucleus pulposus of adult Gdf-5-null mice do not result from abnormal patterning of the embryonic notochord. The use of mouse alleles to mark cells that produce all cell types that reside in the adult nucleus pulposus will allow for a detailed examination of disc formation in other mouse mutants that have been reported to contain disc defects.

Effects of gene deletion of the tissue inhibitor of the matrix metalloproteinase-type 1 (TIMP-1) on left ventricular geometry and function in mice

NASA Technical Reports Server (NTRS)

Roten, L.; Nemoto, S.; Simsic, J.; Coker, M. L.; Rao, V.; Baicu, S.; Defreyte, G.; Soloway, P. J.; Zile, M. R.; Spinale, F. G.

2000-01-01

Alterations in the expression and activity of the matrix metalloproteinases (MMPs) and the tissue inhibitors of the MMPs (TIMPs) have been implicated in tissue remodeling in a number of disease states. One of the better characterized TIMPs, TIMP-1, has been shown to bind to active MMPs and to regulate the MMP activational process. The goal of this study was to determine whether deletion of the TIMP-1 gene in mice, which in turn would remove TIMP-1 expression in LV myocardium, would produce time-dependent effects on LV geometry and function. Age-matched sibling mice (129Sv) deficient in the TIMP-1 gene (TIMP-1 knock-out (TIMP-1 KO), n=10) and wild-type mice (n=10) underwent comparative echocardiographic studies at 1 and 4 months of age. LV catheterization studies were performed at 4 months and the LV harvested for histomorphometric studies. LV end-diastolic volume and mass increased (18+/-4 and 38+/-3%, respectively, P<0.05) at 4 months in the TIMP-1 KO group; a significant increase compared to wild-type controls (P<0.05). At 4 months, LV and end-diastolic wall stress was increased by over two-fold in the TIMP-1 KO compared to wild type (P<0.05). However, LV systolic pressure and ejection performance were unchanged in the two groups of mice. LV myocyte cross-sectional area was unchanged in the TIMP-1 KO mice compared to controls, but myocardial fibrillar collagen content was reduced. Changes in LV geometry occurred in TIMP-1 deficient mice and these results suggest that constitutive TIMP-1 expression participates in the maintenance of normal LV myocardial structure. Copyright 2000 Academic Press.

Sex-biased survival predicts adult sex ratio variation in wild birds

PubMed Central

Székely, Tamás; Liker, András; Freckleton, Robert P.; Fichtel, Claudia; Kappeler, Peter M.

2014-01-01

Adult sex ratio (ASR) is a central concept in population demography and breeding system evolution, and has implications for population viability and biodiversity conservation. ASR exhibits immense interspecific variation in wild populations, although the causes of this variation have remained elusive. Using phylogenetic analyses of 187 avian species from 59 families, we show that neither hatching sex ratios nor fledging sex ratios correlate with ASR. However, sex-biased adult mortality is a significant predictor of ASR, and this relationship is robust to 100 alternative phylogenetic hypotheses, and potential ecological and life-history confounds. A significant component of adult mortality bias is sexual selection acting on males, whereas increased reproductive output predicts higher mortality in females. These results provide the most comprehensive insights into ASR variation to date, and suggest that ASR is an outcome of selective processes operating differentially on adult males and females. Therefore, revealing the causes of ASR variation in wild populations is essential for understanding breeding systems and population dynamics. PMID:24966308

Exacerbation of Diabetic Renal Alterations in Mice Lacking Vasohibin-1

PubMed Central

Hinamoto, Norikazu; Maeshima, Yohei; Yamasaki, Hiroko; Nasu, Tatsuyo; Saito, Daisuke; Watatani, Hiroyuki; Ujike, Haruyo; Tanabe, Katsuyuki; Masuda, Kana; Arata, Yuka; Sugiyama, Hitoshi; Sato, Yasufumi; Makino, Hirofumi

2014-01-01

Vasohibin-1 (VASH1) is a unique endogenous inhibitor of angiogenesis that is induced in endothelial cells by pro-angiogenic factors. We previously reported renoprotective effect of adenoviral delivery of VASH1 in diabetic nephropathy model, and herein investigated the potential protective role of endogenous VASH1 by using VASH1-deficient mice. Streptozotocin-induced type 1 diabetic VASH1 heterozygous knockout mice (VASH1+/−) or wild-type diabetic mice were sacrificed 16 weeks after inducing diabetes. In the diabetic VASH1+/− mice, albuminuria were significantly exacerbated compared with the diabetic wild-type littermates, in association with the dysregulated distribution of glomerular slit diaphragm related proteins, nephrin and ZO-1, glomerular basement membrane thickning and reduction of slit diaphragm density. Glomerular monocyte/macrophage infiltration and glomerular nuclear translocation of phosphorylated NF-κB p65 were significantly exacerbated in the diabetic VASH1+/− mice compared with the diabetic wild-type littermates, accompanied by the augmentation of VEGF-A, M1 macrophage-derived MCP-1 and phosphorylation of IκBα, and the decrease of angiopoietin-1/2 ratio and M2 macrophage-derived Arginase-1. The glomerular CD31+ endothelial area was also increased in the diabetic VASH1+/− mice compared with the diabetic-wild type littermates. Furthermore, the renal and glomerular hypertrophy, glomerular accumulation of mesangial matrix and type IV collagen and activation of renal TGF-β1/Smad3 signaling, a key mediator of renal fibrosis, were exacerbated in the diabetic VASH1+/− mice compared with the diabetic wild-type littermates. In conditionally immortalized mouse podocytes cultured under high glucose condition, transfection of VASH1 small interfering RNA (siRNA) resulted in the reduction of nephrin, angiopoietin-1 and ZO-1, and the augmentation of VEGF-A compared with control siRNA. These results suggest that endogenous VASH1 may regulate the

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

Aggregated Recombinant Human Interferon Beta Induces Antibodies but No Memory in Immune-Tolerant Transgenic Mice

PubMed Central

Sauerborn, Melody; Gilli, Francesca; Brinks, Vera; Schellekens, Huub; Jiskoot, Wim

2010-01-01

ABSTRACT Purpose To study the influence of protein aggregation on the immunogenicity of recombinant human interferon beta (rhIFNβ) in wild-type mice and transgenic, immune-tolerant mice, and to evaluate the induction of immunological memory. Methods RhIFNβ-1b and three rhIFNβ-1a preparations with different aggregate levels were injected intraperitoneally in mice 15× during 3 weeks, and the mice were rechallenged with rhIFNβ-1a. The formation of binding (BABs) and neutralizing antibodies (NABs) was monitored. Results Bulk rhIFNβ-1a contained large, mainly non-covalent aggregates and stressed rhIFNβ-1a mainly covalent, homogeneous (ca. 100 nm) aggregates. Reformulated rhIFNβ-1a was essentially aggregate-free. All products induced BABs and NABs in wild-type mice. Immunogenicity in the transgenic mice was product dependent. RhIFNβ-1b showed the highest and reformulated rhIFNβ-1a the lowest immunogenicity. In contrast with wild-type mice, transgenic mice did not show NABs, nor did they respond to the rechallenge. Conclusions The immunogenicity of the products in transgenic mice, unlike in wild-type mice, varied. In the transgenic mice, neither NABs nor immunological memory developed. The immunogenicity of rhIFNβ in a model reflecting the human immune system depends on the presence and the characteristics of aggregates. PMID:20499141

Whole exome sequencing of an asbestos-induced wild-type murine model of malignant mesothelioma.

PubMed

Sneddon, Sophie; Patch, Ann-Marie; Dick, Ian M; Kazakoff, Stephen; Pearson, John V; Waddell, Nicola; Allcock, Richard J N; Holt, Robert A; Robinson, Bruce W S; Creaney, Jenette

2017-06-02

Malignant mesothelioma (MM) is an aggressive cancer of the pleural and peritoneal cavities caused by exposure to asbestos. Asbestos-induced mesotheliomas in wild-type mice have been used extensively as a preclinical model because they are phenotypically identical to their human counterpart. However, it is not known if the genetic lesions in these mice tumours are similar to in the human disease, a prerequisite for any new preclinical studies that target genetic abnormalities. We performed whole exome sequencing of fifteen asbestos-induced murine MM tumour cell lines from BALB/c, CBA and C57BL/6 mouse strains and compared the somatic mutations and copy number variations with those recurrently reported in human MM. We then catalogued and characterised the mutational landscape of the wild-type murine MM tumours. Quantitative RT-PCR was used to interrogate the expression of key MM genes of interest in the mRNA. Consistent with human MM tumours, we identified homozygous loss of the tumour suppressor Cdkn2a in 14/15 tumours. One tumour retained the first exon of both of the p16INK4a and p19ARF isoforms though this tumour also contained genetic amplification of Myc resulting in increased expression of the c-Myc proto-oncogene in the mRNA. There were no chromosomal losses in either the Bap1 or Nf2 regions. One tumour harbored homozygous loss of Trp53 in the DNA. Mutation rates were similar in tumours generated in the CBA and C57BL/6 strains when compared to human MM. Interestingly, all BALB/c tumour lines displayed high mutational loads, consistent with the known mutator phenotype of the host strain. The Wnt, MAPK and Jak-STAT signaling pathways were found to be the most commonly affected biological pathways. Mutations and copy number deletions also occurred in the Hedgehog and Hippo pathways. These data suggest that in the wild-type murine model asbestos causes mesotheliomas in a similar way to in human MM. This further supports the notion that the murine model of MM

Reduced emotional and corticosterone responses to stress in μ-opioid receptor knockout mice

PubMed Central

Ide, Soichiro; Sora, Ichiro; Ikeda, Kazutaka; Minami, Masabumi; Uhl, George R.; Ishihara, Kumatoshi

2014-01-01

The detailed mechanisms of emotional modulation in the nervous system by opioids remain to be elucidated, although the opioid system is well known to play important roles in the mechanisms of analgesia and drug dependence. In the present study, we conducted behavioral tests of anxiety and depression and measured corticosterone concentrations in both male and female μ-opioid receptor knockout (MOP-KO) mice to reveal the involvement of μ-opioid receptors in stress-induced emotional responses. MOP-KO mice entered more and spent more time in the open arms of the elevated plus maze compared with wild-type mice. MOP-KO mice also displayed significantly decreased immobility in a 15 min tail-suspension test compared with wild-type mice. Similarly, MOP-KO mice exhibited significantly decreased immobility on days 2, 3, and 4 in a 6 min forced swim test conducted for 5 consecutive days. The increase in plasma corticosterone concentration induced by tail-suspension, repeated forced swim, or restraint stress was reduced in MOP-KO mice compared with wild-type mice. Corticosterone levels were not different between wild-type and MOP-KO mice before stress exposure. In contrast, although female mice tended to exhibit fewer anxiety-like responses in the tail-suspension test in both genotypes, no significant gender differences were observed in stress-induced emotional responses. These results suggest that MOPs play an important facilitatory role in emotional responses to stress, including anxiety- and depression-like behavior and corticosterone levels. PMID:19596019

BAX and tumor suppressor TRP53 are important in regulating mutagenesis in spermatogenic cells in mice.

PubMed

Xu, Guogang; Vogel, Kristine S; McMahan, C Alex; Herbert, Damon C; Walter, Christi A

2010-12-01

During the first wave of spermatogenesis, and in response to ionizing radiation, elevated mutant frequencies are reduced to a low level by unidentified mechanisms. Apoptosis is occurring in the same time frame that the mutant frequency declines. We examined the role of apoptosis in regulating mutant frequency during spermatogenesis. Apoptosis and mutant frequencies were determined in spermatogenic cells obtained from Bax-null or Trp53-null mice. The results showed that spermatogenic lineage apoptosis was markedly decreased in Bax-null mice and was accompanied by a significantly increased spontaneous mutant frequency in seminiferous tubule cells compared to that of wild-type mice. Apoptosis profiles in the seminiferous tubules for Trp53-null were similar to control mice. Spontaneous mutant frequencies in pachytene spermatocytes and in round spermatids from Trp53-null mice were not significantly different from those of wild-type mice. However, epididymal spermatozoa from Trp53-null mice displayed a greater spontaneous mutant frequency compared to that from wild-type mice. A greater proportion of spontaneous transversions and a greater proportion of insertions/deletions 15 days after ionizing radiation were observed in Trp53-null mice compared to wild-type mice. Base excision repair activity in mixed germ cell nuclear extracts prepared from Trp53-null mice was significantly lower than that for wild-type controls. These data indicate that BAX-mediated apoptosis plays a significant role in regulating spontaneous mutagenesis in seminiferous tubule cells obtained from neonatal mice, whereas tumor suppressor TRP53 plays a significant role in regulating spontaneous mutagenesis between postmeiotic round spermatid and epididymal spermatozoon stages of spermiogenesis.

BDNF-Deficient Mice Show Reduced Psychosis-Related Behaviors Following Chronic Methamphetamine.

PubMed

Manning, Elizabeth E; Halberstadt, Adam L; van den Buuse, Maarten

2016-04-01

One of the most devastating consequences of methamphetamine abuse is increased risk of psychosis. Brain-derived neurotrophic factor has been implicated in both psychosis and neuronal responses to methamphetamine. We therefore examined persistent psychosis-like behavioral effects of methamphetamine in brain-derived neurotrophic factor heterozygous mice. Mice were chronically treated with methamphetamine from 6 to 9 weeks of age, and locomotor hyperactivity to an acute D-amphetamine challenge was tested in photocell cages after a 2-week withdrawal period. Methamphetamine-treated wild-type mice, but not brain-derived neurotrophic factor heterozygous mice, showed locomotor sensitization to acute 3mg/kg D-amphetamine. Qualitative analysis of exploration revealed tolerance to D-amphetamine effects on entropy in methamphetamine-treated brain-derived neurotrophic factor heterozygous mice, but not wild-type mice. Chronic methamphetamine exposure induces contrasting profiles of behavioral changes in wild-type and brain-derived neurotrophic factor heterozygous mice, with attenuation of behaviors relevant to psychosis in methamphetamine-treated brain-derived neurotrophic factor heterozygous mice. This suggests that brain-derived neurotrophic factor signalling changes may contribute to development of psychosis in methamphetamine users. © The Author 2015. Published by Oxford University Press on behalf of CINP.

Neonatal Iron Supplementation Induces Striatal Atrophy in Female YAC128 Huntington's Disease Mice.

PubMed

Berggren, Kiersten L; Lu, Zhen; Fox, Julia A; Dudenhoeffer, Megan; Agrawal, Sonal; Fox, Jonathan H

2016-01-01

Dysregulation of iron homeostasis is implicated in the pathogenesis of Huntington's disease. We have previously shown that increased iron intake in R6/2 HD neonatal mice, but not adult R6/2 HD mice potentiates disease outcomes at 12-weeks of age corresponding to advanced HD [Redox Biol. 2015;4 : 363-74]. However, whether these findings extend to other HD models is unknown. In particular, it is unclear if increased neonatal iron intake can promote neurodegeneration in mouse HD models where disease onset is delayed to mid-adult life. To determine if increased dietary iron intake in neonatal and adult life-stages potentiates HD in the slowly progressive YAC128 HD mouse model. Female neonatal mice were supplemented daily from days 10-17 with 120μg/g body weight of carbonyl iron. Adult mice were provided diets containing low (50 ppm), medium (150 ppm) and high (500 ppm) iron concentrations from 2-months of age. HD progression was determined using behavioral, brain morphometric and biochemical approaches. Neonatal-iron supplemented YAC128 HD mice had significantly lower striatal volumes and striatal neuronal cell body volumes as compared to control HD mice at 1-year of age. Neonatal-iron supplementation of HD mice had no effect on rota-rod motor endurance and brain iron or glutathione status. Adult iron intake level had no effect on HD progression. YAC128 HD mice had altered peripheral responses to iron intake compared to iron-matched wild-type controls. Female YAC128 HD mice supplemented with nutritionally-relevant levels of iron as neonates demonstrate increased striatal degeneration 1-year later.

Assessment of Dental Fluorosis in Mmp20+/− Mice

PubMed Central

Sharma, R.; Tye, C.E.; Arun, A.; MacDonald, D.; Chatterjee, A.; Abrazinski, T.; Everett, E.T.; Whitford, G.M.; Bartlett, J.D.

2011-01-01

The molecular mechanisms that underlie dental fluorosis are poorly understood. The retention of enamel proteins hallmarking fluorotic enamel may result from impaired hydrolysis and/or removal of enamel proteins. Previous studies have suggested that partial inhibition of Mmp20 expression is involved in the etiology of dental fluorosis. Here we ask if mice expressing only one functional Mmp20 allele are more susceptible to fluorosis. We demonstrate that Mmp20+/− mice express approximately half the amount of MMP20 as do wild-type mice. The Mmp20 heterozygous mice have normal-appearing enamel, with Vickers microhardness values similar to those of wild-type control enamel. Therefore, reduced MMP20 expression is not solely responsible for dental fluorosis. With 50-ppm-fluoride (F−) treatment ad libitum, the Mmp20+/− mice had F− tissue levels similar to those of Mmp20+/+ mice. No significant difference in enamel hardness was observed between the F−-treated heterozygous and wild-type mice. Interestingly, we did find a small but significant difference in quantitative fluorescence between these two groups, which may be attributable to slightly higher protein content in the Mmp20+/− mouse enamel. We conclude that MMP20 plays a nominal role in dental enamel fluorosis. PMID:21386097

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.

Activation of Adiponectin Receptor Regulates Proprotein Convertase Subtilisin/Kexin Type 9 Expression and Inhibits Lesions in ApoE-Deficient Mice.

PubMed

Sun, Lei; Yang, Xiaoxiao; Li, Qi; Zeng, Peng; Liu, Ying; Liu, Lipei; Chen, Yuanli; Yu, Miao; Ma, Chuanrui; Li, Xiaoju; Li, Yan; Zhang, Rongxin; Zhu, Yan; Miao, Qing Robert; Han, Jihong; Duan, Yajun

2017-07-01

The reduced adiponectin levels are associated with atherosclerosis. Adiponectin exerts its functions by activating adiponectin receptor (AdipoR). Proprotein convertase subtilisin kexin type 9 (PCSK9) degrades LDLR protein (low-density lipoprotein receptor) to increase serum LDL-cholesterol levels. PCSK9 expression can be regulated by PPARγ (peroxisome proliferator-activated receptor γ) or SREBP2 (sterol regulatory element-binding protein 2). The effects of AdipoR agonists on PCSK9 and LDLR expression, serum lipid profiles, and atherosclerosis remain unknown. At cellular levels, AdipoR agonists (ADP355 and AdipoRon) induced PCSK9 transcription/expression that solely depended on activation of PPAR-responsive element in the PCSK9 promoter. AdipoR agonists induced PPARγ expression; thus, the AdipoR agonist-activated PCSK9 expression/production was impaired in PPARγ deficient hepatocytes. Meanwhile, AdipoR agonists transcriptionally activated LDLR expression by activating SRE in the LDLR promoter. Moreover, AMP-activated protein kinase α (AMPKα) was involved in AdipoR agonist-activated PCSK9 expression. In wild-type mice, ADP355 increased PCSK9 and LDLR expression and serum PCSK9 levels, which was associated with activation of PPARγ, AMPKα and SREBP2 and reduction of LDL-cholesterol levels. In contrast, ADP355 reduced PCSK9 expression/secretion in apoE-deficient (apoE -/- ) mice, but it still activated hepatic LDLR, PPARγ, AMPKα, and SREBP2. More importantly, ADP355 inhibited lesions in en face aortas and sinus lesions in aortic root in apoE -/- mice with amelioration of lipid profiles. Our study demonstrates that AdipoR activation by agonists regulated PCSK9 expression differently in wild-type and apoE -/- mice. However, ADP355 activated hepatic LDLR expression and ameliorated lipid metabolism in both types of mice and inhibited atherosclerosis in apoE -/- mice. © 2017 American Heart Association, Inc.

Alterations in Ethanol-Induced Behaviors and Consumption in Knock-In Mice Expressing Ethanol-Resistant NMDA Receptors

PubMed Central

den Hartog, Carolina R.; Beckley, Jacob T.; Smothers, Thetford C.; Lench, Daniel H.; Holseberg, Zack L.; Fedarovich, Hleb; Gilstrap, Meghin J.; Homanics, Gregg E.; Woodward, John J.

2013-01-01

Ethanol's action on the brain likely reflects altered function of key ion channels such as glutamatergic N-methyl-D-aspartate receptors (NMDARs). In this study, we determined how expression of a mutant GluN1 subunit (F639A) that reduces ethanol inhibition of NMDARs affects ethanol-induced behaviors in mice. Mice homozygous for the F639A allele died prematurely while heterozygous knock-in mice grew and bred normally. Ethanol (44 mM; ∼0.2 g/dl) significantly inhibited NMDA-mediated EPSCs in wild-type mice but had little effect on responses in knock-in mice. Knock-in mice had normal expression of GluN1 and GluN2B protein across different brain regions and a small reduction in levels of GluN2A in medial prefrontal cortex. Ethanol (0.75–2.0 g/kg; IP) increased locomotor activity in wild-type mice but had no effect on knock-in mice while MK-801 enhanced activity to the same extent in both groups. Ethanol (2.0 g/kg) reduced rotarod performance equally in both groups but knock-in mice recovered faster following a higher dose (2.5 g/kg). In the elevated zero maze, knock-in mice had a blunted anxiolytic response to ethanol (1.25 g/kg) as compared to wild-type animals. No differences were noted between wild-type and knock-in mice for ethanol-induced loss of righting reflex, sleep time, hypothermia or ethanol metabolism. Knock-in mice consumed less ethanol than wild-type mice during daily limited-access sessions but drank more in an intermittent 24 h access paradigm with no change in taste reactivity or conditioned taste aversion. Overall, these data support the hypothesis that NMDA receptors are important in regulating a specific constellation of effects following exposure to ethanol. PMID:24244696

Alterations in ethanol-induced behaviors and consumption in knock-in mice expressing ethanol-resistant NMDA receptors.

PubMed

den Hartog, Carolina R; Beckley, Jacob T; Smothers, Thetford C; Lench, Daniel H; Holseberg, Zack L; Fedarovich, Hleb; Gilstrap, Meghin J; Homanics, Gregg E; Woodward, John J

2013-01-01

Ethanol's action on the brain likely reflects altered function of key ion channels such as glutamatergic N-methyl-D-aspartate receptors (NMDARs). In this study, we determined how expression of a mutant GluN1 subunit (F639A) that reduces ethanol inhibition of NMDARs affects ethanol-induced behaviors in mice. Mice homozygous for the F639A allele died prematurely while heterozygous knock-in mice grew and bred normally. Ethanol (44 mM; ∼0.2 g/dl) significantly inhibited NMDA-mediated EPSCs in wild-type mice but had little effect on responses in knock-in mice. Knock-in mice had normal expression of GluN1 and GluN2B protein across different brain regions and a small reduction in levels of GluN2A in medial prefrontal cortex. Ethanol (0.75-2.0 g/kg; i.p.) increased locomotor activity in wild-type mice but had no effect on knock-in mice while MK-801 enhanced activity to the same extent in both groups. Ethanol (2.0 g/kg) reduced rotarod performance equally in both groups but knock-in mice recovered faster following a higher dose (2.5 g/kg). In the elevated zero maze, knock-in mice had a blunted anxiolytic response to ethanol (1.25 g/kg) as compared to wild-type animals. No differences were noted between wild-type and knock-in mice for ethanol-induced loss of righting reflex, sleep time, hypothermia or ethanol metabolism. Knock-in mice consumed less ethanol than wild-type mice during daily limited-access sessions but drank more in an intermittent 24 h access paradigm with no change in taste reactivity or conditioned taste aversion. Overall, these data support the hypothesis that NMDA receptors are important in regulating a specific constellation of effects following exposure to ethanol.

Lynx1 Limits Dendritic Spine Turnover in the Adult Visual Cortex

PubMed Central

Sajo, Mari

2016-01-01

Dendritic spine turnover becomes limited in the adult cerebral cortex. Identification of specific aspects of spine dynamics that can be unmasked in adulthood and its regulatory molecular mechanisms could provide novel therapeutic targets for inducing plasticity at both the functional and structural levels for robust recovery from brain disorders and injuries in adults. Lynx1, an endogenous inhibitor of nicotinic acetylcholine receptors, was previously shown to increase its expression in adulthood and thus to limit functional ocular dominance plasticity in adult primary visual cortex (V1). However, the role of this “brake” on spine dynamics is not known. We examined the contribution of Lynx1 on dendritic spine turnover before and after monocular deprivation (MD) in adult V1 with chronic in vivo imaging using two-photon microscopy and determined the spine turnover rate of apical dendrites of layer 5 (L5) and L2/3 pyramidal neurons in adult V1 of Lynx1 knock-out (KO) mice. We found that the deletion of Lynx1 doubled the baseline spine turnover rate, suggesting that the spine dynamics in the adult cortex is actively limited by the presence of Lynx1. After MD, adult Lynx1-KO mice selectively exhibit higher rate of spine loss with no difference in gain rate in L5 neurons compared with control wild-type counterparts, revealing a key signature of spine dynamics associated with robust functional plasticity in adult V1. Overall, Lynx1 could be a promising therapeutic target to induce not only functional, but also structural plasticity at the level of spine dynamics in the adult brain. SIGNIFICANCE STATEMENT Dendritic spine turnover becomes limited in the adult cortex. In mouse visual cortex, a premier model of experience-dependent plasticity, we found that the deletion of Lynx1, a nicotinic “brake” for functional plasticity, doubled the baseline spine turnover in adulthood, suggesting that the spine dynamics in the adult cortex is actively limited by Lynx1. After

Deletion of vanilloid receptor (TRPV1) in mice alters behavioral effects of ethanol

PubMed Central

Blednov, Y.A.; Harris, R.A.

2009-01-01

The vanilloid receptor TRPV1 is activated by ethanol and this may be important for some of the central and peripheral actions of ethanol. To determine if this receptor has a role in ethanol-mediated behaviors, we studied null mutant mice in which the Trpv1 gene was deleted. Mice lacking this gene showed significantly higher preference for ethanol and consumed more ethanol in a two-bottle choice test as compared with wild type littermates. Null mutant mice showed shorter duration of loss of righting reflex induced by low doses of ethanol (3.2 and 3.4 g/kg) and faster recovery from motor incoordination induced by ethanol (2 g/kg). However, there were no differences between null mutant and wild type mice in severity of ethanol-induced acute withdrawal (4 g/kg) or conditioned taste aversion to ethanol (2.5 g/kg). Two behavioral phenotypes (decreased sensitivity to ethanol-induced sedation and faster recovery from ethanol-induced motor incoordination) seen in null mutant mice were reproduced in wild type mice by injection of a TRPV1 antagonist, capsazepine (10 mg/kg). These two ethanol behaviors were changed in the opposite direction after injection of capsaicin, a selective TRPV1 agonist, in wild type mice. The studies provide the first evidence that TRPV1 is important for specific behavioral actions of ethanol. PMID:19705551

Brain and retinal ferroportin 1 dysregulation in polycythaemia mice.

PubMed

Iacovelli, Jared; Mlodnicka, Agnieska E; Veldman, Peter; Ying, Gui-Shuang; Dunaief, Joshua L; Schumacher, Armin

2009-09-15

Disruption of iron homeostasis within the central nervous system (CNS) can lead to profound abnormalities during both development and aging in mammals. The radiation-induced polycythaemia (Pcm) mutation, a 58-bp microdeletion in the promoter region of ferroportin 1 (Fpn1), disrupts transcriptional and post-transcriptional regulation of this pivotal iron transporter. This regulatory mutation induces dynamic alterations in peripheral iron homeostasis such that newborn homozygous Pcm mice exhibit iron deficiency anemia with increased duodenal Fpn1 expression while adult homozygotes display decreased Fpn1 expression and anemia despite organismal iron overload. Herein we report the impact of the Pcm microdeletion on iron homeostasis in two compartments of the central nervous system: brain and retina. At birth, Pcm homozygotes show a marked decrease in brain iron content and reduced levels of Fpn1 expression. Upregulation of transferrin receptor 1 (TfR1) in brain microvasculature appears to mediate the compensatory iron uptake during postnatal development and iron content in Pcm brain is restored to wild-type levels by 7 weeks of age. Similarly, changes in expression are transient and expression of Fpn1 and TfR1 is indistinguishable between Pcm homozygotes and wild-type by 12 weeks of age. Strikingly, the adult Pcm brain is effectively protected from the peripheral iron overload and maintains normal iron content. In contrast to Fpn1 downregulation in perinatal brain, the retina of Pcm homozygotes reveals increased levels of Fpn1 expression. While retinal morphology appears normal at birth and during early postnatal development, adult Pcm mice demonstrate a marked, age-dependent loss of photoreceptors. This phenotype demonstrates the importance of iron homeostasis in retinal health.

AGED DOMINANT NEGATIVE p38α MAPK MICE ARE RESISTANT TO AGE-DEPENDENT DECLINE IN ADULT-NEUROGENESIS AND CONTEXT DISCRIMINATION FEAR CONDITIONING

PubMed Central

Cortez, IbDanelo; Bulavin, Dmitry V.; Wu, Ping; McGrath, Erica L; Cunningham, Kathryn A; Wakamiya, Maki; Papaconstantinou, John; Dineley, Kelly T

2018-01-01

A major aspect of mammalian aging is the decline in functional competence of many self-renewing cell types, including adult-born neuronal precursors. Since age-related senescence of self-renewal occurs simultaneously with chronic up-regulation of the p38MAPKalpha (p38α) signaling pathway, we used the dominant negative mouse model for attenuated p38α activity (DN-p38αAF/+ ) in which Thr180 and Tyr182 are mutated (T→A/Y→F) to prevent phosphorylation activation (DN-p38αAF/+) and kinase activity. As a result, aged DN-p38αAF/+ mice are resistant to age-dependent decline in proliferation and regeneration of several peripheral tissue progenitors when compared to wild-type littermates. Aging is the major risk factor for non-inherited forms of Alzheimer’s disease (AD); environmental and genetic risk factors that accelerate the senescence phenotype are thought to contribute to an individual’s relative risk. In the present study, we evaluated aged DN-p38αAF/+ and wildtype littermates in a series of behavioral paradigms to test if p38α mutant mice exhibit altered baseline abnormalities in neurological reflexes, locomotion, anxiety-like behavior, and age-dependent cognitive decline. While aged DN-p38αAF/+ and wildtype littermates appear equal in all tested baseline neurological and behavioral parameters, DN-p38αAF/+ exhibit superior context discrimination fear conditioning. Context discrimination is a cognitive task that is supported by proliferation and differentiation of adult-born neurons in the dentate gyrus of the hippocampus. Consistent with enhanced context discrimination in aged DN-p38αAF/+, we discovered enhanced production of adult-born neurons in the dentate gyrus of DN-p38αAF/+ mice compared to wildtype littermates. Our findings support the notion that p38α inhibition has therapeutic utility in aging diseases that affect cognition, such as AD. PMID:27765672

Aged dominant negative p38α MAPK mice are resistant to age-dependent decline in adult-neurogenesis and context discrimination fear conditioning.

PubMed

Cortez, IbDanelo; Bulavin, Dmitry V; Wu, Ping; McGrath, Erica L; Cunningham, Kathryn A; Wakamiya, Maki; Papaconstantinou, John; Dineley, Kelly T

2017-03-30

A major aspect of mammalian aging is the decline in functional competence of many self-renewing cell types, including adult-born neuronal precursors. Since age-related senescence of self-renewal occurs simultaneously with chronic up-regulation of the p38MAPKalpha (p38α) signaling pathway, we used the dominant negative mouse model for attenuated p38α activity (DN-p38α AF/+ ) in which Thr180 and Tyr182 are mutated (T→A/Y→F) to prevent phosphorylation activation (DN-p38α AF/+ ) and kinase activity. As a result, aged DN-p38α AF/+ mice are resistant to age-dependent decline in proliferation and regeneration of several peripheral tissue progenitors when compared to wild-type littermates. Aging is the major risk factor for non-inherited forms of Alzheimer's disease (AD); environmental and genetic risk factors that accelerate the senescence phenotype are thought to contribute to an individual's relative risk. In the present study, we evaluated aged DN-p38α AF/+ and wildtype littermates in a series of behavioral paradigms to test if p38α mutant mice exhibit altered baseline abnormalities in neurological reflexes, locomotion, anxiety-like behavior, and age-dependent cognitive decline. While aged DN-p38α AF/+ and wildtype littermates appear equal in all tested baseline neurological and behavioral parameters, DN-p38α AF/+ exhibit superior context discrimination fear conditioning. Context discrimination is a cognitive task that is supported by proliferation and differentiation of adult-born neurons in the dentate gyrus of the hippocampus. Consistent with enhanced context discrimination in aged DN-p38α AF/+ , we discovered enhanced production of adult-born neurons in the dentate gyrus of DN-p38α AF/+ mice compared to wildtype littermates. Our findings support the notion that p38α inhibition has therapeutic utility in aging diseases that affect cognition, such as AD. Copyright © 2016 Elsevier B.V. All rights reserved.

Sex-biased survival predicts adult sex ratio variation in wild birds.

PubMed

Székely, Tamás; Liker, András; Freckleton, Robert P; Fichtel, Claudia; Kappeler, Peter M

2014-08-07

Adult sex ratio (ASR) is a central concept in population demography and breeding system evolution, and has implications for population viability and biodiversity conservation. ASR exhibits immense interspecific variation in wild populations, although the causes of this variation have remained elusive. Using phylogenetic analyses of 187 avian species from 59 families, we show that neither hatching sex ratios nor fledging sex ratios correlate with ASR. However, sex-biased adult mortality is a significant predictor of ASR, and this relationship is robust to 100 alternative phylogenetic hypotheses, and potential ecological and life-history confounds. A significant component of adult mortality bias is sexual selection acting on males, whereas increased reproductive output predicts higher mortality in females. These results provide the most comprehensive insights into ASR variation to date, and suggest that ASR is an outcome of selective processes operating differentially on adult males and females. Therefore, revealing the causes of ASR variation in wild populations is essential for understanding breeding systems and population dynamics. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

Distinct Luminal-Type Mammary Carcinomas Arise from Orthotopic Trp53-Null Mammary Transplantation of Juvenile versus Adult Mice

DOE PAGES

Nguyen, David H.; Ouyang, Haoxu; Mao, Jian-Hua; ...

2014-12-01

Age and physiologic status, such as menopause, are risk factors for breast cancer. Less clear is what factors influence the diversity of breast cancer. In this study, we investigated the effect of host age on the distribution of tumor subtypes in mouse mammary chimera consisting of wild-type hosts and Trp53 nullizygous epithelium, which undergoes a high rate of neoplastic transformation. Wild-type mammary glands cleared of endogenous epithelium at 3 weeks of age were subsequently transplanted during puberty (5 weeks) or at maturation (10 weeks) with syngeneic Trp53-null mammary tissue fragments and monitored for one year. Tumors arose sooner from adultmore » hosts (AH) compared with juvenile hosts (JH). However, compared with AH tumors, JH tumors grew several times faster, were more perfused, exhibited a two-fold higher mitotic index, and were more highly positive for insulin-like growth factor receptor phosphorylation. Most tumors in each setting were estrogen receptor (ER)-positive (80% JH vs. 70% AH), but JH tumors were significantly more ER-immunoreactive (P = 0.0001) than AH tumors. A differential expression signature (JvA) of juvenile versus adult tumors revealed a luminal transcriptional program. Centroids of the human homologs of JvA genes showed that JH tumors were more like luminal A tumors and AH tumors were more like luminal B tumors. Hierarchical clustering with the JvA human ortholog gene list segregated luminal A and luminal B breast cancers across datasets. Lastly, these data support the notion that age-associated host physiology greatly influences the intrinsic subtype of breast cancer.« less

Distinct Luminal-Type Mammary Carcinomas Arise from Orthotopic Trp53-Null Mammary Transplantation of Juvenile versus Adult Mice

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

Nguyen, David H.; Ouyang, Haoxu; Mao, Jian-Hua

Age and physiologic status, such as menopause, are risk factors for breast cancer. Less clear is what factors influence the diversity of breast cancer. In this study, we investigated the effect of host age on the distribution of tumor subtypes in mouse mammary chimera consisting of wild-type hosts and Trp53 nullizygous epithelium, which undergoes a high rate of neoplastic transformation. Wild-type mammary glands cleared of endogenous epithelium at 3 weeks of age were subsequently transplanted during puberty (5 weeks) or at maturation (10 weeks) with syngeneic Trp53-null mammary tissue fragments and monitored for one year. Tumors arose sooner from adultmore » hosts (AH) compared with juvenile hosts (JH). However, compared with AH tumors, JH tumors grew several times faster, were more perfused, exhibited a two-fold higher mitotic index, and were more highly positive for insulin-like growth factor receptor phosphorylation. Most tumors in each setting were estrogen receptor (ER)-positive (80% JH vs. 70% AH), but JH tumors were significantly more ER-immunoreactive (P = 0.0001) than AH tumors. A differential expression signature (JvA) of juvenile versus adult tumors revealed a luminal transcriptional program. Centroids of the human homologs of JvA genes showed that JH tumors were more like luminal A tumors and AH tumors were more like luminal B tumors. Hierarchical clustering with the JvA human ortholog gene list segregated luminal A and luminal B breast cancers across datasets. Lastly, these data support the notion that age-associated host physiology greatly influences the intrinsic subtype of breast cancer.« less

Role of Fyn-mediated NMDA receptor function in prediabetic neuropathy in mice

PubMed Central

Suo, Meng; Wang, Ping

2016-01-01

Diabetic neuropathy is a common complication of diabetes. This study evaluated the role of Fyn kinase and N-methyl-d-aspartate receptors (NMDARs) in the spinal cord in diabetic neuropathy using an animal model of high-fat diet-induced prediabetes. We found that prediabetic wild-type mice exhibited tactile allodynia and thermal hypoalgesia after a 16-wk high-fat diet, relative to normal diet-fed wild-type mice. Furthermore, prediabetic wild-type mice exhibited increased tactile allodynia and thermal hypoalgesia at 24 wk relative to 16 wk. Such phenomena were correlated with increased expression and activation of NR2B subunit of NMDARs, as well as Fyn-NR2B interaction in the spinal cord. Fyn−/− mice developed prediabetes after 16-wk high-fat diet treatment and exhibited thermal hypoalgesia, without showing tactile allodynia or altered expression and activation of NR2B subunit, relative to normal diet-fed Fyn−/− mice. Finally, intrathecal administrations of Ro 25-6981 (selective NR2B subunit-containing NMDAR antagonist) dose-dependently alleviated tactile allodynia, but not thermal hypoalgesia, at 16 and 24 wk in prediabetic wild-type mice. Our results suggested that Fyn-mediated NR2B signaling plays a critical role in regulation of prediabetic neuropathy and that the increased expression/function of NR2B subunit-containing NMDARs may contribute to the progression of neuropathy in type 2 diabetes. PMID:27146985

Gene expression patterns in the hippocampus during the development and aging of Glud1 (Glutamate Dehydrogenase 1) transgenic and wild type mice.

PubMed

Wang, Xinkun; Patel, Nilam D; Hui, Dongwei; Pal, Ranu; Hafez, Mohamed M; Sayed-Ahmed, Mohamed M; Al-Yahya, Abdulaziz A; Michaelis, Elias K

2014-03-04

Extraneuronal levels of the neurotransmitter glutamate in brain rise during aging. This is thought to lead to synaptic dysfunction and neuronal injury or death. To study the effects of glutamate hyperactivity in brain, we created transgenic (Tg) mice in which the gene for glutamate dehydrogenase (Glud1) is over-expressed in neurons and in which such overexpression leads to excess synaptic release of glutamate. In this study, we analyzed whole genome expression in the hippocampus, a region important for learning and memory, of 10 day to 20 month old Glud1 and wild type (wt) mice. During development, maturation and aging, both Tg and wt exhibited decreases in the expression of genes related to neurogenesis, neuronal migration, growth, and process elongation, and increases in genes related to neuro-inflammation, voltage-gated channel activity, and regulation of synaptic transmission. Categories of genes that were differentially expressed in Tg vs. wt during development were: synaptic function, cytoskeleton, protein ubiquitination, and mitochondria; and, those differentially expressed during aging were: synaptic function, vesicle transport, calcium signaling, protein kinase activity, cytoskeleton, neuron projection, mitochondria, and protein ubiquitination. Overall, the effects of Glud1 overexpression on the hippocampus transcriptome were greater in the mature and aged than the young. Glutamate hyperactivity caused gene expression changes in the hippocampus at all ages. Some of these changes may result in premature brain aging. The identification of these genomic expression differences is important in understanding the effects of glutamate dysregulation on neuronal function during aging or in neurodegenerative diseases.

Diacylglycerol Lipase α Knockout Mice Demonstrate Metabolic and Behavioral Phenotypes Similar to Those of Cannabinoid Receptor 1 Knockout Mice

PubMed Central

Powell, David R.; Gay, Jason P.; Wilganowski, Nathaniel; Doree, Deon; Savelieva, Katerina V.; Lanthorn, Thomas H.; Read, Robert; Vogel, Peter; Hansen, Gwenn M.; Brommage, Robert; Ding, Zhi-Ming; Desai, Urvi; Zambrowicz, Brian

2015-01-01

After creating >4,650 knockouts (KOs) of independent mouse genes, we screened them by high-throughput phenotyping and found that cannabinoid receptor 1 (Cnr1) KO mice had the same lean phenotype published by others. We asked if our KOs of DAG lipase α or β (Dagla or Daglb), which catalyze biosynthesis of the endocannabinoid (EC) 2-arachidonoylglycerol (2-AG), or Napepld, which catalyzes biosynthesis of the EC anandamide, shared the lean phenotype of Cnr1 KO mice. We found that Dagla KO mice, but not Daglb or Napepld KO mice, were among the leanest of 3651 chow-fed KO lines screened. In confirmatory studies, chow- or high fat diet-fed Dagla and Cnr1 KO mice were leaner than wild-type (WT) littermates; when data from multiple cohorts of adult mice were combined, body fat was 47 and 45% lower in Dagla and Cnr1 KO mice, respectively, relative to WT values. By contrast, neither Daglb nor Napepld KO mice were lean. Weanling Dagla KO mice ate less than WT mice and had body weight (BW) similar to pair-fed WT mice, and adult Dagla KO mice had normal activity and VO2 levels, similar to Cnr1 KO mice. Our Dagla and Cnr1 KO mice also had low fasting insulin, triglyceride, and total cholesterol levels, and after glucose challenge had normal glucose but very low insulin levels. Dagla and Cnr1 KO mice also showed similar responses to a battery of behavioral tests. These data suggest: (1) the lean phenotype of young Dagla and Cnr1 KO mice is mainly due to hypophagia; (2) in pathways where ECs signal through Cnr1 to regulate food intake and other metabolic and behavioral phenotypes observed in Cnr1 KO mice, Dagla alone provides the 2-AG that serves as the EC signal; and (3) small molecule Dagla inhibitors with a pharmacokinetic profile similar to that of Cnr1 inverse agonists are likely to mirror the ability of these Cnr1 inverse agonists to lower BW and improve glycemic control in obese patients with type 2 diabetes, but may also induce undesirable neuropsychiatric side

Anti-Müllerian hormone may regulate the number of calbindin-positive neurons in the sexually dimorphic nucleus of the preoptic area of male mice

PubMed Central

2013-01-01

Background The male brain is putatively organised early in development by testosterone, with the sexually dimorphic nucleus of the medial preoptic area (SDN) a main exemplifier of this. However, pubescent neurogenesis occurs in the rat SDN, and the immature testes secrete anti-Müllerian hormone (AMH) as well as testosterone. We have therefore re-examined the development of the murine SDN to determine whether it is influenced by AMH and/or whether the number of calbindin-positive (calbindin+ve) neurons in it changes after pre-pubescent development. Methods In mice, the SDN nucleus is defined by calbindin+ve neurons (CALB-SDN). The number and size of the neurons in the CALB-SDN of male and female AMH null mutant (Amh-/-) mice and their wild-type littermates (Amh+/+) were studied using stereological techniques. Groups of mice were examined immediately before the onset of puberty (20 days postnatal) and at adulthood (129–147 days old). Results The wild-type pre-pubertal male mice had 47% more calbindin+ve neurons in the CALB-SDN than their female wild-type littermates. This sex difference was entirely absent in Amh-/- mice. In adults, the extent of sexual dimorphism almost doubled due to a net reduction in the number and size of calbindin+ve neurons in females and a net increase in neuron number in males. These changes occurred to a similar extent in the Amh-/- and Amh+/+ mice. Consequently, the number of calbindin+ve neurons in Amh-/- adult male mice was intermediate between Amh+/+ males and Amh+/+ females. The sex difference in the size of the neurons was predominantly generated by a female-specific atrophy after 20 days, independent of AMH. Conclusions The establishment of dimorphic cell number in the CALB-SDN of mice is biphasic, with each phase being subject to different regulation. The second phase of dimorphism is not dependent on the first phase having occurred as it was present in the Amh-/- male mice that have female-like numbers of calbindin+ve neurons at

Anti-Müllerian hormone may regulate the number of calbindin-positive neurons in the sexually dimorphic nucleus of the preoptic area of male mice.

PubMed

Wittmann, Walter; McLennan, Ian S

2013-10-11

The male brain is putatively organised early in development by testosterone, with the sexually dimorphic nucleus of the medial preoptic area (SDN) a main exemplifier of this. However, pubescent neurogenesis occurs in the rat SDN, and the immature testes secrete anti-Müllerian hormone (AMH) as well as testosterone. We have therefore re-examined the development of the murine SDN to determine whether it is influenced by AMH and/or whether the number of calbindin-positive (calbindin+ve) neurons in it changes after pre-pubescent development. In mice, the SDN nucleus is defined by calbindin+ve neurons (CALB-SDN). The number and size of the neurons in the CALB-SDN of male and female AMH null mutant (Amh-/-) mice and their wild-type littermates (Amh+/+) were studied using stereological techniques. Groups of mice were examined immediately before the onset of puberty (20 days postnatal) and at adulthood (129-147 days old). The wild-type pre-pubertal male mice had 47% more calbindin+ve neurons in the CALB-SDN than their female wild-type littermates. This sex difference was entirely absent in Amh-/- mice. In adults, the extent of sexual dimorphism almost doubled due to a net reduction in the number and size of calbindin+ve neurons in females and a net increase in neuron number in males. These changes occurred to a similar extent in the Amh-/- and Amh+/+ mice. Consequently, the number of calbindin+ve neurons in Amh-/- adult male mice was intermediate between Amh+/+ males and Amh+/+ females. The sex difference in the size of the neurons was predominantly generated by a female-specific atrophy after 20 days, independent of AMH. The establishment of dimorphic cell number in the CALB-SDN of mice is biphasic, with each phase being subject to different regulation. The second phase of dimorphism is not dependent on the first phase having occurred as it was present in the Amh-/- male mice that have female-like numbers of calbindin+ve neurons at 20 days. These observations extend

The skeletal structure of insulin-like growth factor I-deficient mice

NASA Technical Reports Server (NTRS)

Bikle, D.; Majumdar, S.; Laib, A.; Powell-Braxton, L.; Rosen, C.; Beamer, W.; Nauman, E.; Leary, C.; Halloran, B.

2001-01-01

The importance of insulin-like growth factor I (IGF-I) for growth is well established. However, the lack of IGF-I on the skeleton has not been examined thoroughly. Therefore, we analyzed the structural properties of bone from mice rendered IGF-I deficient by homologous recombination (knockout [k/o]) using histomorphometry, peripheral quantitative computerized tomography (pQCT), and microcomputerized tomography (muCT). The k/o mice were 24% the size of their wild-type littermates at the time of study (4 months). The k/o tibias were 28% and L1 vertebrae were 26% the size of wild-type bones. Bone formation rates (BFR) of k/o tibias were 27% that of the wild-type littermates. The k/o bones responded normally to growth hormone (GH; 1.7-fold increase) and supranormally to IGF-I (5.2-fold increase) with respect to BFR. Cortical thickness of the proximal tibia was reduced 17% in the k/o mouse. However, trabecular bone volume (bone volume/total volume [BV/TV]) was increased 23% (male mice) and 88% (female mice) in the k/o mice compared with wild-type controls as a result of increased connectivity, increased number, and decreased spacing of the trabeculae. These changes were either less or not found in L1. Thus, lack of IGF-I leads to the development of a bone structure, which, although smaller, appears more compact.

Critical role of IFN-gamma in CFA-mediated protection of NOD mice from diabetes development.

PubMed

Mori, Yoshiko; Kodaka, Tetsuro; Kato, Takako; Kanagawa, Edith M; Kanagawa, Osami

2009-11-01

IFN-gamma signaling-deficient non-obese diabetic (NOD) mice develop diabetes with similar kinetics to those of wild-type NOD mice. However, the immunization of IFN-gamma signaling-deficient NOD mice with CFA failed to induce long-term protection, whereas wild-type NOD mice receiving CFA remained diabetes-free. CFA also failed to protect IFN-gamma receptor-deficient (IFN-gammaR(-/-)) NOD mice from the autoimmune rejection of transplanted islets, as it does in diabetic NOD mice, and from disease transfer by spleen cells from diabetic NOD mice. These data clearly show that the pro-inflammatory cytokine IFN-gamma is necessary for the CFA-mediated protection of NOD mice from diabetes. There is no difference in the T(h)1/T(h)17 balance between IFN-gammaR(-/-) NOD and wild-type NOD mice. There is also no difference in the total numbers and percentages of regulatory T (Treg) cells in the lymph node CD4(+) T-cell populations between IFN-gammaR(-/-) NOD and wild-type NOD mice. However, pathogenic T cells lacking IFN-gammaR are resistant to the suppressive effect of Treg cells, both in vivo and in vitro. Therefore, it is likely that CFA-mediated protection against diabetes development depends on a change in the balance between Treg cells and pathogenic T cells, and IFN-gamma signaling seems to control the susceptibility of pathogenic T cells to the inhibitory activity of Treg cells.

Resistin deficiency in mice has no effect on pulmonary responses induced by acute ozone exposure

PubMed Central

Razvi, Shehla S.; Richards, Jeremy B.; Malik, Farhan; Cromar, Kevin R.; Price, Roger E.; Bell, Cynthia S.; Weng, Tingting; Atkins, Constance L.; Spencer, Chantal Y.; Cockerill, Katherine J.; Alexander, Amy L.; Blackburn, Michael R.; Alcorn, Joseph L.; Haque, Ikram U.

2015-01-01

Acute exposure to ozone (O3), an air pollutant, causes pulmonary inflammation, airway epithelial desquamation, and airway hyperresponsiveness (AHR). Pro-inflammatory cytokines—including IL-6 and ligands of chemokine (C-X-C motif) receptor 2 [keratinocyte chemoattractant (KC) and macrophage inflammatory protein (MIP)-2], TNF receptor 1 and 2 (TNF), and type I IL-1 receptor (IL-1α and IL-1β)—promote these sequelae. Human resistin, a pleiotropic hormone and cytokine, induces expression of IL-1α, IL-1β, IL-6, IL-8 (the human ortholog of murine KC and MIP-2), and TNF. Functional differences exist between human and murine resistin; yet given the aforementioned observations, we hypothesized that murine resistin promotes O3-induced lung pathology by inducing expression of the same inflammatory cytokines as human resistin. Consequently, we examined indexes of O3-induced lung pathology in wild-type and resistin-deficient mice following acute exposure to either filtered room air or O3. In wild-type mice, O3 increased bronchoalveolar lavage fluid (BALF) resistin. Furthermore, O3 increased lung tissue or BALF IL-1α, IL-6, KC, TNF, macrophages, neutrophils, and epithelial cells in wild-type and resistin-deficient mice. With the exception of KC, which was significantly greater in resistin-deficient compared with wild-type mice, no genotype-related differences in the other indexes existed following O3 exposure. O3 caused AHR to acetyl-β-methylcholine chloride (methacholine) in wild-type and resistin-deficient mice. However, genotype-related differences in airway responsiveness to methacholine were nonexistent subsequent to O3 exposure. Taken together, these data demonstrate that murine resistin is increased in the lungs of wild-type mice following acute O3 exposure but does not promote O3-induced lung pathology. PMID:26386120

Running rescues defective adult neurogenesis by shortening the length of the cell cycle of neural stem and progenitor cells.

PubMed

Farioli-Vecchioli, Stefano; Mattera, Andrea; Micheli, Laura; Ceccarelli, Manuela; Leonardi, Luca; Saraulli, Daniele; Costanzi, Marco; Cestari, Vincenzo; Rouault, Jean-Pierre; Tirone, Felice

2014-07-01

Physical exercise increases the generation of new neurons in adult neurogenesis. However, only few studies have investigated the beneficial effects of physical exercise in paradigms of impaired neurogenesis. Here, we demonstrate that running fully reverses the deficient adult neurogenesis within the hippocampus and subventricular zone of the lateral ventricle, observed in mice lacking the antiproliferative gene Btg1. We also evaluated for the first time how running influences the cell cycle kinetics of stem and precursor subpopulations of wild-type and Btg1-null mice, using a new method to determine the cell cycle length. Our data show that in wild-type mice running leads to a cell cycle shortening only of NeuroD1-positive progenitor cells. In contrast, in Btg1-null mice, physical exercise fully reactivates the defective hippocampal neurogenesis, by shortening the S-phase length and the overall cell cycle duration of both neural stem (glial fibrillary acidic protein(+) and Sox2(+)) and progenitor (NeuroD1(+)) cells. These events are sufficient and necessary to reactivate the hyperproliferation observed in Btg1-null early-postnatal mice and to expand the pool of adult neural stem and progenitor cells. Such a sustained increase of cell proliferation in Btg1-null mice after running provides a long-lasting increment of proliferation, differentiation, and production of newborn neurons, which rescues the impaired pattern separation previously identified in Btg1-null mice. This study shows that running positively affects the cell cycle kinetics of specific subpopulations of newly generated neurons and suggests that the plasticity of neural stem cells without cell cycle inhibitory control is reactivated by running, with implications for the long-term modulation of neurogenesis. © 2014 AlphaMed Press.

Chronic and acute intranasal oxytocin produce divergent social effects in mice.

PubMed

Huang, Huiping; Michetti, Caterina; Busnelli, Marta; Managò, Francesca; Sannino, Sara; Scheggia, Diego; Giancardo, Luca; Sona, Diego; Murino, Vittorio; Chini, Bice; Scattoni, Maria Luisa; Papaleo, Francesco

2014-04-01

Intranasal administration of oxytocin (OXT) might be a promising new adjunctive therapy for mental disorders characterized by social behavioral alterations such as autism and schizophrenia. Despite promising initial studies in humans, it is not yet clear the specificity of the behavioral effects induced by chronic intranasal OXT and if chronic intranasal OXT could have different effects compared with single administration. This is critical for the aforementioned chronic mental disorders that might potentially involve life-long treatments. As a first step to address these issues, here we report that chronic intranasal OXT treatment in wild-type C57BL/6J adult mice produced a selective reduction of social behaviors concomitant to a reduction of the OXT receptors throughout the brain. Conversely, acute intranasal OXT treatment produced partial increases in social behaviors towards opposite-sex novel-stimulus female mice, while on the other hand, it decreased social exploration of same-sex novel stimulus male mice, without affecting social behavior towards familiar stimulus male mice. Finally, prolonged exposure to intranasal OXT treatments did not alter, in wild-type animals, parameters of general health such as body weight, locomotor activity, olfactory and auditory functions, nor parameters of memory and sensorimotor gating abilities. These results indicate that a prolonged over-stimulation of a 'healthy' oxytocinergic brain system, with no inherent deficits in social interaction and normal endogenous levels of OXT, results in specific detrimental effects in social behaviors.

ALDOSTERONE-INDUCED VASCULAR REMODELING AND ENDOTHELIAL DYSFUNCTION REQUIRE FUNCTIONAL ANGIOTENSIN TYPE 1a RECEPTORS

PubMed Central

Coelho, Suellen C.; Ouerd, Sofiane; Rautureau, Yohann; Coffman, Thomas M.; Paradis, Pierre; Schiffrin, Ernesto L.

2016-01-01

We investigated the role of angiotensin type 1a receptors (AGTR1a) in vascular injury induced by aldosterone activation of mineralocorticoid receptors (MR) in Agtr1a−/− and wild-type mice infused with aldosterone for 14 days while receiving 1% NaCl in drinking water. Aldosterone increased systolic blood pressure by ~30 mmHg in wild-type mice, and ~50 mmHg in Agtr1a−/− mice. Aldosterone induced aortic and small artery remodeling and impaired endothelium-dependent relaxation in wild-type mice, and enhanced fibronectin and collagen deposition, and vascular inflammation. None of these vascular effects were observed in Agtr1a−/− mice. Aldosterone effects were prevented by the AGTR1 antagonist losartan in wild-type mice. In contrast to aldosterone, norepinephrine caused similar BP increase and mesenteric artery remodeling in wild-type and Agtr1a−/− mice. Agtr1a−/− mice infused with aldosterone did not increase sodium excretion in response to a sodium chloride challenge, suggesting sodium retention that could contribute to the exaggerated blood pressure rise induced by aldosterone. Agtr1a−/− mice had decreased mesenteric artery expression of the calcium-activated potassium channel Kcnmb1, which may enhance myogenic tone and together with sodium retention exacerbate BP responses to aldosterone/salt in Agtr1a−/− mice. We conclude that although aldosterone activation of MR raises BP more in Agtr1a−/− mice, AGTR1a is required for MR stimulation to induce vascular remodeling and inflammation, and endothelial dysfunction. PMID:27045029

Rcan2 and estradiol independently regulate body weight in female mice

PubMed Central

Ding, Ling-Cui; Gong, Qian-Qian; Li, Shi-Wei; Fu, Xiao-Long; Jin, Ye-Cheng; Zhang, Jian; Gao, Jian-Gang; Sun, Xiao-Yang

2017-01-01

Rcan2 increases food intake and plays an important role in the development of age- and diet- induced obesity in male mice. However, in females, wild-type mice grow almost at a similar rate as Rcan2−/− mice on normal chow diet from 6 weeks of age. Here we showed that the ability of Rcan2 to promote weight gain was attenuated by energy expenditure mediated by 17β-estradiol in female mice. Using ovariectomy-operated models, we found that 17β-estradiol deprivation did not alter food intake, but induced more weight gain in wild-type mice than Rcan2−/− mice. If wild-type mice ingested equally as Rcan2−/− mice, in the same ovarian state they exhibited similar weight changes, but the mice in ovariectomized groups were significantly heavier than the ovarian-intact mice, suggesting that body weight is not only regulated by Rcan2, but also by 17β-estradiol. Furthermore, we demonstrated that Rcan2 and 17β-estradiol independently regulated body weight even on high-fat diets. Therefore, our findings indicate that Rcan2 and 17β-estradiol regulate body weight through different mechanisms. Rcan2 increases food intake, whereas 17β-estradiol promotes energy expenditure. These findings provide novel insights into the sexual dimorphism of body weight regulation. PMID:28624805

Dominant negative retinoic acid receptor initiates tumor formation in mice.

PubMed

Kupumbati, Tara S; Cattoretti, Giorgio; Marzan, Christine; Farias, Eduardo F; Taneja, Reshma; Mira-y-Lopez, Rafael

2006-03-24

Retinoic acid suppresses cell growth and promotes cell differentiation, and pharmacological retinoic acid receptor (RAR) activation is anti-tumorigenic. This begs the question of whether chronic physiological RAR activation by endogenous retinoids is likewise anti-tumorigenic. To address this question, we generated transgenic mice in which expression of a ligand binding defective dominant negative RARalpha (RARalphaG303E) was under the control of the mouse mammary tumor virus (MMTV) promoter. The transgene was expressed in the lymphoid compartment and in the mammary epithelium. Observation of aging mice revealed that transgenic mice, unlike their wild type littermates, developed B cell lymphomas at high penetrance, with a median latency of 40 weeks. MMTV-RARalphaG303E lymphomas were high grade Pax-5+, surface H+L Ig negative, CD69+ and BCL6- and cytologically and phenotypically resembled human adult high grade (Burkitt's or lymphoblastic) lymphomas. We postulated that mammary tumors might arise after a long latency period as seen in other transgenic models of breast cancer. We tested this idea by transplanting transgenic epithelium into the cleared fat pads of wild type hosts, thus bypassing lymphomagenesis. At 17 months post-transplantation, a metastatic mammary adenocarcinoma developed in one of four transplanted glands whereas no tumors developed in sixteen of sixteen endogenous glands with wild type epithelium. These findings suggest that physiological RAR activity may normally suppress B lymphocyte and mammary epithelial cell growth and that global RAR inactivation is sufficient to initiate a stochastic process of tumor development requiring multiple transforming events. Our work makes available to the research community a new animal resource that should prove useful as an experimental model of aggressive sporadic lymphoma in immunologically uncompromised hosts. We anticipate that it may also prove useful as a model of breast cancer.

Assortative mating among animals of captive and wild origin following experimental conservation releases

PubMed Central

Slade, Brendan; Parrott, Marissa L.; Paproth, Aleisha; Magrath, Michael J. L.; Gillespie, Graeme R.; Jessop, Tim S.

2014-01-01

Captive breeding is a high profile management tool used for conserving threatened species. However, the inevitable consequence of generations in captivity is broad scale and often-rapid phenotypic divergence between captive and wild individuals, through environmental differences and genetic processes. Although poorly understood, mate choice preference is one of the changes that may occur in captivity that could have important implications for the reintroduction success of captive-bred animals. We bred wild-caught house mice for three generations to examine mating patterns and reproductive outcomes when these animals were simultaneously released into multiple outdoor enclosures with wild conspecifics. At release, there were significant differences in phenotypic (e.g. body mass) and genetic measures (e.g. Gst and F) between captive-bred and wild adult mice. Furthermore, 83% of offspring produced post-release were of same source parentage, inferring pronounced assortative mating. Our findings suggest that captive breeding may affect mating preferences, with potentially adverse implications for the success of threatened species reintroduction programmes. PMID:25411380

Effects of Aging and Oxidative Stress on Spermatozoa of Superoxide-Dismutase 1- and Catalase-Null Mice.

PubMed

Selvaratnam, Johanna S; Robaire, Bernard

2016-09-01

Advanced paternal age is linked to complications in pregnancy and genetic diseases in offspring. Aging results in excess reactive oxygen species (ROS) and DNA damage in spermatozoa; this damage can be transmitted to progeny with detrimental consequences. Although there is a loss of antioxidants with aging, the impact on aging male germ cells of the complete absence of either catalase (CAT) or superoxide dismutase 1 (SOD1) has not been investigated. We used CAT-null (Cat(-/-)) and SOD1-null (Sod(-/-)) mice to determine whether loss of these antioxidants increases germ cell susceptibility to redox dysfunction with aging. Aging reduced fertility and the numbers of Sertoli and germ cells in all mice. Aged Sod(-/-) mice displayed an increased loss of fertility compared to aged wild-type mice. Treatment with the pro-oxidant SIN-10 increased ROS in spermatocytes of aged wild-type and Sod(-/-) mice, while aged Cat(-/-) mice were able to neutralize this ROS. The antioxidant peroxiredoxin 1 (PRDX1) increased with age in wild-type and Cat(-/-) mice but was consistently low in young and aged Sod(-/-) mice. DNA damage and repair markers (γ-H2AX and 53BP1) were reduced with aging and lower in young Sod(-/-) and Cat(-/-) mice. Colocalization of γ-H2AX and 53BP1 suggested active repair in young wild-type mice but reduced in young Cat(-/-) and in Sod(-/-) mice and with age. Oxidative DNA damage (8-oxodG) increased in young Sod(-/-) mice and with age in all mice. These studies show that aged Sod(-/-) mice display severe redox dysfunction, while wild-type and Cat(-/-) mice have compensatory mechanisms to partially alleviate oxidative stress and reduce age-related DNA damage in spermatozoa. Thus, SOD1 but not CAT is critical to the maintenance of germ cell quality with aging. © 2016 by the Society for the Study of Reproduction, Inc.

Eye pigments in wild-type and eye-color mutant strains of the African malaria vector Anopheles gambiae.

PubMed

Beard, C B; Benedict, M Q; Primus, J P; Finnerty, V; Collins, F H

1995-01-01

Chromatographic analysis of pigments extracted from wild-type eyes of the mosquito Anopheles gambiae reveals the presence of the ommatin precursor 3-hydroxykynurenine, its transamination derivative xanthurenic acid, and a dark, red-brown pigment spot that probably is composed of two or more low mobility xanthommatins. No colored or fluorescent pteridines are evident. Mosquitoes homozygous for an autosomal recessive mutation at the red-eye (r) locus have a brick-red eye color in larvae, pupae, and young adults, in contrast to the almost black color of the wild eye. Mosquitoes homozygous for this mutant allele have levels of ommochrome precursors that are indistinguishable from the wild-type, but the low-mobility xanthommatin spot is ochre-brown in color rather than red-brown as in the wild-type. Mosquitoes with two different mutant alleles at the X-linked pink-eye locus (p, which confers a pink eye color, and pw, which confers a white eye phenotype in homozygotes or hemizygous males) have normal levels of ommochrome precursors but no detectable xanthommatins. Mosquitoes homozygous for both the r and p mutant alleles have apricot-colored eyes and show no detectable xanthommatins. Both the pink-eye and red-eye mutations appear to involve defects in the transport into or assembly of pigments in the membrane-bound pigment granules rather then defects in ommochrome synthesis.

Inflammation and airway hyperresponsiveness after chlorine exposure are prolonged by Nrf2 deficiency in mice.

PubMed

Ano, Satoshi; Panariti, Alice; Allard, Benoit; O'Sullivan, Michael; McGovern, Toby K; Hamamoto, Yoichiro; Ishii, Yukio; Yamamoto, Masayuki; Powell, William S; Martin, James G

2017-01-01

Chlorine gas (Cl 2 ) is a potent oxidant and trigger of irritant induced asthma. We explored NF-E2-related factor 2 (Nrf2)-dependent mechanisms in the asthmatic response to Cl 2 , using Nrf2-deficient mice, buthionine sulfoximine (BSO), an inhibitor of glutathione (GSH) synthesis and sulforaphane (SFN), a phytochemical regulator of Nrf2. Airway inflammation and airway hyperresponsiveness (AHR) were assessed 24 and 48h after a 5-min nose-only exposure to 100ppm Cl 2 of Nrf2-deficient and wild type Balb/C mice treated with BSO or SFN. Animals were anesthetized, paralyzed and mechanically ventilated (FlexiVent™) and challenged with aerosolized methacholine. Bronchoalveolar lavage (BAL) was performed and lung tissues were harvested for assessment of gene expression. Cl 2 exposure induced a robust AHR and an intense neutrophilic inflammation that, although similar in Nrf2-deficient mice and wild-type mice at 24h after Cl 2 exposure, were significantly greater at 48h post exposure in Nrf2-deficient mice. Lung GSH and mRNA for Nrf2-dependent phase II enzymes (NQO-1 and GPX2) were significantly lower in Nrf2-deficient than wild-type mice after Cl 2 exposure. BSO reduced GSH levels and promoted Cl 2 -induced airway inflammation in wild-type mice, but not in Nrf2-deficient mice, whereas SFN suppressed Cl 2 -induced airway inflammation in wild-type but not in Nrf2-deficient mice. AHR was not affected by either BSO or SFN at 48h post Cl 2 exposure. Nrf2-dependent phase II enzymes play a role in the resolution of airway inflammation and AHR after Cl 2 exposure. Moderate deficiency of GSH affects the magnitude of acute inflammation but not AHR. Copyright © 2016 Elsevier Inc. All rights reserved.

Wild-type male offspring of fmr-1+/- mothers exhibit characteristics of the fragile X phenotype.

PubMed

Zupan, Bojana; Toth, Miklos

2008-10-01

Fragile X syndrome is an X-linked disorder caused by the inactivation of the FMR-1 gene with symptoms ranging from impaired cognitive functions to seizures, anxiety, sensory abnormalities, and hyperactivity. Males are more severely affected than heterozygote (H) females, who, as carriers, have a 50% chance of transmitting the mutated allele in each pregnancy. fmr-1 knockout (KO) mice reproduce fragile X symptoms, including hyperactivity, seizures, and abnormal sensory processing. In contrast to the expectation that wild-type (WT) males born to H (fmr-1(+/-)) mothers (H>WT) are behaviorally normal and indistinguishable from WT males born to WT mothers (WT>WT); here, we show that H>WT offspring are more active than WT>WT offspring and that their hyperactivity is similar to male KO mice born to H or KO (fmr-1(-/-)) mothers (H>KO/KO>KO). H>WT mice, however, do not exhibit seizures or abnormal sensory processing. Consistent with their hyperactivity, the effect of the D2 agonist quinpirole is reduced in H>WT as well as in H>KO and KO>KO mice compared to WT>WT offspring, suggesting a diminished feedback inhibition of dopamine release. Our data indicate that some aspects of hyperactivity and associated dopaminergic changes in 'fragile X' mice are a maternal fmr-1 genotype rather than an offspring fmr-1 genotype effect.

Methamphetamine- and 1-methyl-4-phenyl- 1,2,3, 6-tetrahydropyridine-induced dopaminergic neurotoxicity in inducible nitric oxide synthase-deficient mice.

PubMed

Itzhak, Y; Martin, J L; Ali, S F

1999-12-15

Previous studies have suggested a role for the retrograde messenger, nitric oxide (NO), in methamphetamine (METH)- and 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)- induced dopaminergic neurotoxicity. Since evidence supported the involvement of the neuronal nitric oxide synthase (nNOS) isoform in the dopaminergic neurotoxicity, the present study was undertaken to investigate whether the inducible nitric oxide synthase (iNOS) isoform is also associated with METH- and MPTP-induced neurotoxicity. The administration of METH (5mg/kg x 3) to iNOS deficient mice [homozygote iNOS(-/-)] and wild type mice (C57BL/6) resulted in significantly smaller depletion of striatal dopaminergic markers in the iNOS(-/-) mice compared with the wild-type mice. METH-induced hyperthermia was also significantly lower in the iNOS(-/-) mice than in wild-type mice. In contrast to the outcome of METH administration, MPTP injections (20 mg/kg x 3) resulted in a similar decrease in striatal dopaminergic markers in iNOS(-/-) and wild-type mice. In the set of behavioral experiments, METH-induced locomotor sensitization was investigated. The acute administration of METH (1.0 mg/kg) resulted in the same intensity of locomotor activity in iNOS(-/-) and wild-type mice. Moreover, 68 to 72 h after the exposure to the high-dose METH regimen (5 mg/kg x 3), a marked sensitized response to a challenge injection of METH (1.0 mg/kg) was observed in both the iNOS(-/-) and wild-type mice. The finding that iNOS(-/-) mice were unprotected from MPTP-induced neurotoxicity suggests that the partial protection against METH-induced neurotoxicity observed was primarily associated with the diminished hyperthermic effect of METH seen in the iNOS(-/-) mice. Moreover, in contrast to nNOS deficiency, iNOS deficiency did not affect METH-induced behavioral sensitization. Copyright 1999 Wiley-Liss, Inc.

Prolonged lifespan with enhanced exploratory behavior in mice overexpressing the oxidized nucleoside triphosphatase hMTH1.

PubMed

De Luca, Gabriele; Ventura, Ilenia; Sanghez, Valentina; Russo, Maria Teresa; Ajmone-Cat, Maria Antonietta; Cacci, Emanuele; Martire, Alberto; Popoli, Patrizia; Falcone, Germana; Michelini, Flavia; Crescenzi, Marco; Degan, Paolo; Minghetti, Luisa; Bignami, Margherita; Calamandrei, Gemma

2013-08-01

The contribution that oxidative damage to DNA and/or RNA makes to the aging process remains undefined. In this study, we used the hMTH1-Tg mouse model to investigate how oxidative damage to nucleic acids affects aging. hMTH1-Tg mice express high levels of the hMTH1 hydrolase that degrades 8-oxodGTP and 8-oxoGTP and excludes 8-oxoguanine from both DNA and RNA. Compared to wild-type animals, hMTH1-overexpressing mice have significantly lower steady-state levels of 8-oxoguanine in both nuclear and mitochondrial DNA of several organs, including the brain. hMTH1 overexpression prevents the age-dependent accumulation of DNA 8-oxoguanine that occurs in wild-type mice. These lower levels of oxidized guanines are associated with increased longevity and hMTH1-Tg animals live significantly longer than their wild-type littermates. Neither lipid oxidation nor overall antioxidant status is significantly affected by hMTH1 overexpression. At the cellular level, neurospheres derived from adult hMTH1-Tg neural progenitor cells display increased proliferative capacity and primary fibroblasts from hMTH1-Tg embryos do not undergo overt senescence in vitro. The significantly lower levels of oxidized DNA/RNA in transgenic animals are associated with behavioral changes. These mice show reduced anxiety and enhanced investigation of environmental and social cues. Longevity conferred by overexpression of a single nucleotide hydrolase in hMTH1-Tg animals is an example of lifespan extension associated with healthy aging. It provides a link between aging and oxidative damage to nucleic acids. © 2013 John Wiley & Sons Ltd and the Anatomical Society.

Pivotal role of IL-6 in the hyperinflammatory responses to subacute ozone in adiponectin-deficient mice

PubMed Central

Kim, Hye Y.; Mathews, Joel A.; Verbout, Norah G.; Williams, Alison S.; Wurmbrand, Allison P.; Ninin, Fernanda M. C.; Neto, Felippe L.; Benedito, Leandro A. P.; Hug, Christopher; Umetsu, Dale T.; Shore, Stephanie A.

2013-01-01

Adiponectin is an adipose-derived hormone with anti-inflammatory activity. Following subacute ozone exposure (0.3 ppm for 24–72 h), neutrophilic inflammation and IL-6 are augmented in adiponectin-deficient (Adipo−/−) mice. The IL-17/granulocyte colony-stimulating factor (G-CSF) axis is required for this increased neutrophilia. We hypothesized that elevated IL-6 in Adipo−/− mice contributes to their augmented responses to ozone via effects on IL-17A expression. Therefore, we generated mice deficient in both adiponectin and IL-6 (Adipo−/−/IL-6−/−) and exposed them to ozone or air. In ozone-exposed mice, bronchoalveolar lavage (BAL) neutrophils, IL-6, and G-CSF, and pulmonary Il17a mRNA expression were greater in Adipo−/− vs. wild-type mice, but reduced in Adipo−/−/IL-6−/− vs. Adipo−/− mice. IL-17A+ F4/80+ cells and IL-17A+ γδ T cells were also reduced in Adipo−/−/IL-6−/− vs. Adipo−/− mice exposed to ozone. Only BAL neutrophils were reduced in IL-6−/− vs. wild-type mice. In wild-type mice, IL-6 was expressed in Gr-1+F4/80−CD11c− cells, whereas in Adipo−/− mice F4/80+CD11c+ cells also expressed IL-6, suggesting that IL-6 is regulated by adiponectin in these alveolar macrophages. Transcriptomic analysis identified serum amyloid A3 (Saa3), which promotes IL-17A expression, as the gene most differentially augmented by ozone in Adipo−/− vs. wild-type mice. After ozone, Saa3 mRNA expression was markedly greater in Adipo−/− vs. wild-type mice but reduced in Adipo−/−/IL-6−/− vs. Adipo−/− mice. In conclusion, our data support a pivotal role of IL-6 in the hyperinflammatory condition observed in Adipo−/− mice after ozone exposure and suggest that this role of IL-6 involves its ability to induce Saa3, IL-17A, and G-CSF. PMID:24381131

Resistance of neuronal nitric oxide synthase-deficient mice to methamphetamine-induced dopaminergic neurotoxicity.

PubMed

Itzhak, Y; Gandia, C; Huang, P L; Ali, S F

1998-03-01

Methamphetamine (METH) is a powerful psychostimulant that produces dopaminergic neurotoxicity manifested by a decrease in the levels of dopamine, tyrosine hydroxylase activity and dopamine transporter (DAT) binding sites in the nigrostriatal system. We have recently reported that blockade of the neuronal nitric oxide synthase (nNOS) isoform by 7-nitroindazole provides protection against METH-induced neurotoxicity in Swiss Webster mice. The present study was undertaken to investigate the effect of a neurotoxic dose of METH on mutant mice lacking the nNOS gene [nNOS(-/-)] and wild-type controls. In addition, we sought to investigate the behavioral outcome of exposure to a neurotoxic dose of METH. Homozygote nNOS(-/-), heterozygote nNOS(+/-) and wild-type animals were administered either saline or METH (5 mg/kg x 3). Dopamine, DOPAC and HVA levels, as well as DAT binding site levels, were determined in striatal tissue derived 72 h after the last METH injection. This regimen of METH given to nNOS(-/-) mice affected neither the tissue content of dopamine and its metabolites nor the number of DAT binding sites. Although a moderate reduction in the levels of dopamine (35%) and DAT binding sites (32%) occurred in striatum of heterozygote nNOS(+/-) mice, a more profound depletion of the dopaminergic markers (up to 68%) was observed in the wild-type animals. METH-induced hyperthermia was observed in all animal strains examined except the nNOS(-/-) mice. Investigation of the animals' spontaneous locomotor activity before and after administration of the neurotoxic dose of METH (5 mg/kg x 3) revealed no differences. A low dose of METH (1.0 mg/kg) administered to naive animals (nNOS(-/-) and wild-type) resulted in a similar intensity of locomotor stimulation. However, 68 to 72 h after exposure to the high-dose METH regimen, a marked sensitized responses to a challenge METH injection was observed in the wild-type mice but not in the nNOS(-/-) mice. Taken together, these results

Excess TSH causes abnormal skeletal development in young mice with hypothyroidism via suppressive effects on the growth plate.

PubMed

Endo, Toyoshi; Kobayashi, Tetsuro

2013-09-01

Hypothyroidism in the young leads to irreversible growth failure. hyt/hyt Mice have a nonfunctional TSH receptor (TSHR) and are severely hypothyroid, but growth retardation was not observed in adult mice. We found that epiphysial cartilage as well as cultured chondrocytes expressed functional TSHR at levels comparable to that seen in the thyroid, and that addition of TSH to cultured chondrocytes suppressed expression of chondrocyte differentiation marker genes such as Sox-9 and type IIa collagen. Next, we compared the long bone phenotypes of two distinct mouse models of hypothyroidism: thyroidectomized (THYx) mice and hyt/hyt mice. Although both THYx and hyt/hyt mice were severely hypothyroid and had similar serum Ca(2+) and growth hormone levels, the tibia was shorter and the proliferating and hypertrophic zones in the growth plate was significantly narrower in THYx mice than in hyt/hyt mice. Supplementation of hyt/hyt mice thyroid hormone resulted in a wider growth plate compared with that of wild-type mice. Expressions of chondrocyte differentiation marker genes Sox-9 and type IIa collagen in growth plate from THYx mice were 52 and 60% lower than those of hyt/hyt mice, respectively. High serum TSH causes abnormal skeletal development in young mice with hypothyroidism via suppressive effects on the growth plate.

Myelin/oligodendrocyte glycoprotein–deficient (MOG-deficient) mice reveal lack of immune tolerance to MOG in wild-type mice

PubMed Central

Delarasse, Cécile; Daubas, Philippe; Mars, Lennart T.; Vizler, Csaba; Litzenburger, Tobias; Iglesias, Antonio; Bauer, Jan; Della Gaspera, Bruno; Schubart, Anna; Decker, Laurence; Dimitri, Dalia; Roussel, Guy; Dierich, Andrée; Amor, Sandra; Dautigny, André; Liblau, Roland; Pham-Dinh, Danielle

2003-01-01

We studied the immunological basis for the very potent encephalitogenicity of myelin/oligodendrocyte glycoprotein (MOG), a minor component of myelin in the CNS that is widely used to induce experimental autoimmune encephalomyelitis (EAE). For this purpose, we generated a mutant mouse lacking a functional mog gene. This MOG-deficient mouse presents no clinical or histological abnormalities, permitting us to directly assess the role of MOG as a target autoantigen in EAE. In contrast to WT mice, which developed severe EAE following immunization with whole myelin, MOG-deficient mice had a mild phenotype, demonstrating that the anti-MOG response is a major pathogenic component of the autoimmune response directed against myelin. Moreover, while MOG transcripts are expressed in lymphoid organs in minute amounts, both MOG-deficient and WT mice show similar T and B cell responses against the extracellular domain of MOG, including the immunodominant MOG 35–55 T cell epitope. Furthermore, no differences in the fine specificity of the T cell responses to overlapping peptides covering the complete mouse MOG sequence were observed between MOG+/+ and MOG–/– mice. In addition, upon adoptive transfer, MOG-specific T cells from WT mice and those from MOG-deficient mice are equally pathogenic. This total lack of immune tolerance to MOG in WT C57BL/6 mice may be responsible for the high pathogenicity of the anti-MOG immune response as well as the high susceptibility of most animal strains to MOG-induced EAE. PMID:12925695

Type 3 deiodinase deficiency results in functional abnormalities at multiple levels of the thyroid axis.

PubMed

Hernandez, Arturo; Martinez, M Elena; Liao, Xiao-Hui; Van Sande, Jacqueline; Refetoff, Samuel; Galton, Valerie Anne; St Germain, Donald L

2007-12-01

The type 3 deiodinase (D3) is a selenoenzyme that inactivates thyroid hormones and is highly expressed during development and in the adult central nervous system. We have recently observed that mice lacking D3 activity (D3KO mice) develop perinatal thyrotoxicosis followed in adulthood by a pattern of hormonal levels that is suggestive of central hypothyroidism. In this report we describe the results of additional studies designed to investigate the regulation of the thyroid axis in this unique animal model. Our results demonstrate that the thyroid and pituitary glands of D3KO mice do not respond appropriately to TSH and TRH stimulation, respectively. Furthermore, after induction of severe hypothyroidism by antithyroid treatment, the rise in serum TSH in D3KO mice is only 15% of that observed in wild-type mice. In addition, D3KO animals rendered severely hypothyroid fail to show the expected increase in prepro-TRH mRNA in the paraventricular nucleus of the hypothalamus. Finally, treatment with T(3) results in a serum T(3) level in D3KO mice that is much higher than that in wild-type mice. This is accompanied by significant weight loss and lethality in mutant animals. In conclusion, the absence of D3 activity results in impaired clearance of T(3) and significant defects in the mechanisms regulating the thyroid axis at all levels: hypothalamus, pituitary, and thyroid.

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

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.

5-Lypoxygenase products are involved in renal tubulointerstitial injury induced by albumin overload in proximal tubules in mice.

PubMed

Landgraf, Sharon Schilling; Silva, Leandro Souza; Peruchetti, Diogo Barros; Sirtoli, Gabriela Modenesi; Moraes-Santos, Felipe; Portella, Viviane Gomes; Silva-Filho, João Luiz; Pinheiro, Carla Silva; Abreu, Thiago Pereira; Takiya, Christina Maeda; Benjamin, Claudia Farias; Pinheiro, Ana Acacia Sá; Canetti, Claudio; Caruso-Neves, Celso

2014-01-01

The role of albumin overload in proximal tubules (PT) in the development of tubulointerstitial injury and, consequently, in the progression of renal disease has become more relevant in recent years. Despite the importance of leukotrienes (LTs) in renal disease, little is known about their role in tubulointerstitial injury. The aim of the present work was to investigate the possible role of LTs on tubulointerstitial injury induced by albumin overload. An animal model of tubulointerstitial injury challenged by bovine serum albumin was developed in SV129 mice (wild-type) and 5-lipoxygenase-deficient mice (5-LO(-/-)). The changes in glomerular morphology and nestin expression observed in wild-type mice subjected to kidney insult were also observed in 5-LO(-/-) mice. The levels of urinary protein observed in the 5-LO(-/-) mice subjected or not to kidney insult were lower than those observed in respective wild-type mice. Furthermore, the increase in lactate dehydrogenase activity, a marker of tubule damage, observed in wild-type mice subjected to kidney insult did not occur in 5-LO(-/-) mice. LTB4 and LTD4, 5-LO products, decreased the uptake of albumin in LLC-PK1 cells, a well-characterized porcine PT cell line. This effect correlated with activation of protein kinase C and inhibition of protein kinase B. The level of proinflammatory cytokines, tumor necrosis factor-α and interleukin (IL)-6, increased in mice subjected to kidney insult but this effect was not modified in 5-LO(-/-) mice. However, 5-LO(-/-) mice subjected to kidney insult presented lower macrophage infiltration and higher levels of IL-10 than wild-type mice. Our results reveal that LTs have an important role in tubulointerstitial disease induced by albumin overload.

5-Lypoxygenase Products Are Involved in Renal Tubulointerstitial Injury Induced by Albumin Overload in Proximal Tubules in Mice

PubMed Central

Landgraf, Sharon Schilling; Silva, Leandro Souza; Peruchetti, Diogo Barros; Sirtoli, Gabriela Modenesi; Moraes-Santos, Felipe; Portella, Viviane Gomes; Silva-Filho, João Luiz; Pinheiro, Carla Silva; Abreu, Thiago Pereira; Takiya, Christina Maeda; Benjamin, Claudia Farias; Pinheiro, Ana Acacia Sá; Canetti, Claudio; Caruso-Neves, Celso

2014-01-01

The role of albumin overload in proximal tubules (PT) in the development of tubulointerstitial injury and, consequently, in the progression of renal disease has become more relevant in recent years. Despite the importance of leukotrienes (LTs) in renal disease, little is known about their role in tubulointerstitial injury. The aim of the present work was to investigate the possible role of LTs on tubulointerstitial injury induced by albumin overload. An animal model of tubulointerstitial injury challenged by bovine serum albumin was developed in SV129 mice (wild-type) and 5-lipoxygenase-deficient mice (5-LO–/–). The changes in glomerular morphology and nestin expression observed in wild-type mice subjected to kidney insult were also observed in 5-LO–/– mice. The levels of urinary protein observed in the 5-LO–/– mice subjected or not to kidney insult were lower than those observed in respective wild-type mice. Furthermore, the increase in lactate dehydrogenase activity, a marker of tubule damage, observed in wild-type mice subjected to kidney insult did not occur in 5-LO–/– mice. LTB4 and LTD4, 5-LO products, decreased the uptake of albumin in LLC-PK1 cells, a well-characterized porcine PT cell line. This effect correlated with activation of protein kinase C and inhibition of protein kinase B. The level of proinflammatory cytokines, tumor necrosis factor-α and interleukin (IL)-6, increased in mice subjected to kidney insult but this effect was not modified in 5-LO–/– mice. However, 5-LO–/– mice subjected to kidney insult presented lower macrophage infiltration and higher levels of IL-10 than wild-type mice. Our results reveal that LTs have an important role in tubulointerstitial disease induced by albumin overload. PMID:25302946

Mice lacking melanin-concentrating hormone receptor 1 demonstrate increased heart rate associated with altered autonomic activity.

PubMed

Astrand, Annika; Bohlooly-Y, Mohammad; Larsdotter, Sara; Mahlapuu, Margit; Andersén, Harriet; Tornell, Jan; Ohlsson, Claes; Snaith, Mike; Morgan, David G A

2004-10-01

Melanin-concentrating hormone (MCH) plays an important role in energy balance. The current studies were carried out on a new line of mice lacking the rodent MCH receptor (MCHR1(-/-) mice). These mice confirmed the previously reported lean phenotype characterized by increased energy expenditure and modestly increased caloric intake. Because MCH is expressed in the lateral hypothalamic area, which also has an important role in the regulation of the autonomic nervous system, heart rate and blood pressure were measured by a telemetric method to investigate whether the increased energy expenditure in these mice might be due to altered autonomic nervous system activity. Male MCHR1(-/-) mice demonstrated a significantly increased heart rate [24-h period: wild type 495 +/- 4 vs. MCHR1(-/-) 561 +/- 8 beats/min (P < 0.001); dark phase: wild type 506 +/- 8 vs. MCHR1(-/-) 582 +/- 9 beats/min (P < 0.001); light phase: wild type 484 +/- 13 vs. MCHR1(-/-) 539 +/- 9 beats/min (P < 0.005)] with no significant difference in mean arterial pressure [wild type 110 +/- 0.3 vs. MCHR1(-/-) 113 +/- 0.4 mmHg (P > 0.05)]. Locomotor activity and core body temperature were higher in the MCHR1(-/-) mice during the dark phase only and thus temporally dissociated from heart rate differences. On fasting, wild-type animals rapidly downregulated body temperature and heart rate. MCHR1(-/-) mice displayed a distinct delay in the onset of this downregulation. To investigate the mechanism underlying these differences, autonomic blockade experiments were carried out. Administration of the adrenergic antagonist metoprolol completely reversed the tachycardia seen in MCHR1(-/-) mice, suggesting an increased sympathetic tone.

Dcdc2 knockout mice display exacerbated developmental disruptions following knockdown of Dcx

PubMed Central

Wang, Yu; Yin, Xiuyin; Rosen, Glenn; Gabel, Lisa; Guadiana, Sarah M.; Sarkisian, Matthew R; Galaburda, Albert M.; LoTurco, Joseph J.

2011-01-01

The dyslexia-associated gene DCDC2 is a member of the DCX family of genes known to play roles in neurogenesis, neuronal migration and differentiation. Here we report the first phenotypic analysis of a Dcdc2 knockout mouse. Comparisons between Dcdc2 knockout mice and wild type littermates revealed no significant differences in neuronal migration, neocortical lamination, neuronal cilliogenesis or dendritic differentiation. Considering previous studies showing genetic interactions and potential functional redundancy among members of the DCX family, we tested whether decreasing Dcx expression by RNAi would differentially impair neurodevelopment in Dcdc2 knockouts and wild type mice. Consistent with this hypothesis, we found that deficits in neuronal migration, and dendritic growth caused by RNAi of Dcx were more severe in Dcdc2 knockouts than in wild type mice with the same transfection. These results indicate that Dcdc2 is not required for neurogenesis, neuronal migration or differentiation in mice, but may have partial functional redundancy with Dcx. PMID:21689730

Effects of Aging and Oxidative Stress on Spermatozoa of Superoxide-Dismutase 1- and Catalase-Null Mice1

PubMed Central

Selvaratnam, Johanna S.; Robaire, Bernard

2016-01-01

Advanced paternal age is linked to complications in pregnancy and genetic diseases in offspring. Aging results in excess reactive oxygen species (ROS) and DNA damage in spermatozoa; this damage can be transmitted to progeny with detrimental consequences. Although there is a loss of antioxidants with aging, the impact on aging male germ cells of the complete absence of either catalase (CAT) or superoxide dismutase 1 (SOD1) has not been investigated. We used CAT-null (Cat−/−) and SOD1-null (Sod−/−) mice to determine whether loss of these antioxidants increases germ cell susceptibility to redox dysfunction with aging. Aging reduced fertility and the numbers of Sertoli and germ cells in all mice. Aged Sod−/− mice displayed an increased loss of fertility compared to aged wild-type mice. Treatment with the pro-oxidant SIN-10 increased ROS in spermatocytes of aged wild-type and Sod−/− mice, while aged Cat−/− mice were able to neutralize this ROS. The antioxidant peroxiredoxin 1 (PRDX1) increased with age in wild-type and Cat−/− mice but was consistently low in young and aged Sod−/− mice. DNA damage and repair markers (γ-H2AX and 53BP1) were reduced with aging and lower in young Sod−/− and Cat−/− mice. Colocalization of γ-H2AX and 53BP1 suggested active repair in young wild-type mice but reduced in young Cat−/− and in Sod−/− mice and with age. Oxidative DNA damage (8-oxodG) increased in young Sod−/− mice and with age in all mice. These studies show that aged Sod−/− mice display severe redox dysfunction, while wild-type and Cat−/− mice have compensatory mechanisms to partially alleviate oxidative stress and reduce age-related DNA damage in spermatozoa. Thus, SOD1 but not CAT is critical to the maintenance of germ cell quality with aging. PMID:27465136

Impact of Peptide Transporter 1 on the Intestinal Absorption and Pharmacokinetics of Valacyclovir after Oral Dose Escalation in Wild-Type and PepT1 Knockout Mice

PubMed Central

Yang, Bei; Hu, Yongjun

2013-01-01

The primary objective of this study was to determine the in vivo absorption properties of valacyclovir, including the potential for saturable proton-coupled oligopeptide transporter 1 (PepT1)-mediated intestinal uptake, after escalating oral doses of prodrug within the clinical dose range. A secondary aim was to characterize the role of PepT1 on the tissue distribution of its active metabolite, acyclovir. [3H]Valacyclovir was administered to wild-type (WT) and PepT1 knockout (KO) mice by oral gavage at doses of 10, 25, 50, and 100 nmol/g. Serial blood samples were collected over 180 minutes, and tissue distribution studies were performed 20 minutes after a 25-nmol/g oral dose of valacyclovir. We found that the Cmax and area under the curve (AUC)0–180 of acyclovir were 4- to 6-fold and 2- to 3-fold lower, respectively, in KO mice for all four oral doses of valacyclovir. The time to peak concentration of acyclovir was 3- to 10-fold longer in KO compared with WT mice. There was dose proportionality in the Cmax and AUC0–180 of acyclovir in WT and KO mice over the valacyclovir oral dose range of 10–100 nmol/g (i.e., linear absorption kinetics). No differences were observed in the peripheral tissue distribution of acyclovir once these tissues were adjusted for differences in perfusing drug concentrations in the systemic circulation. In contrast, some differences were observed between genotypes in the concentrations of acyclovir in the distal intestine. Collectively, the findings demonstrate a critical role of intestinal PepT1 in improving the rate and extent of oral absorption for valacyclovir. Moreover, this study provides definitive evidence for the rational development of a PepT1-targeted prodrug strategy. PMID:23924683

Neurokinin B is critical for normal timing of sexual maturation but dispensable for adult reproductive function in female mice.

PubMed

True, Cadence; Nasrin Alam, Sayeda; Cox, Kimberly; Chan, Yee-Ming; Seminara, Stephanie B

2015-04-01

Humans carrying mutations in neurokinin B (NKB) or the NKB receptor fail to undergo puberty due to decreased secretion of GnRH. Despite this pubertal delay, many of these patients go on to achieve activation of their hypothalamic-pituitary-gonadal axis in adulthood, a phenomenon termed reversal, indicating that NKB signaling may play a more critical role for the timing of pubertal development than adult reproductive function. NKB receptor-deficient mice are hypogonadotropic but have no defects in the timing of sexual maturation. The current study has performed the first phenotypic evaluation of mice bearing mutations in Tac2, the gene encoding the NKB ligand, to determine whether they have impaired sexual development similar to their human counterparts. Male Tac2-/- mice showed no difference in the timing of sexual maturation or fertility compared with wild-type littermates and were fertile. In contrast, Tac2-/- females had profound delays in sexual maturation, with time to vaginal opening and first estrus occurring significantly later than controls, and initial abnormalities in estrous cycles. However, cycling recovered in adulthood and Tac2-/- females were fertile, although they produced fewer pups per litter. Thus, female Tac2-/- mice parallel humans harboring NKB pathway mutations, with delayed sexual maturation and activation of the reproductive cascade later in life. Moreover, direct comparison of NKB ligand and receptor-deficient females confirmed that only NKB ligand-deficient animals have delayed sexual maturation, suggesting that in the absence of the NKB receptor, NKB may regulate the timing of sexual maturation through other tachykinin receptors.

Neonatal Iron Supplementation Induces Striatal Atrophy in Female YAC128 Huntington’s Disease Mice

PubMed Central

Berggren, Kiersten L.; Lu, Zhen; Fox, Julia A.; Dudenhoeffer, Megan; Agrawal, Sonal; Fox, Jonathan H.

2016-01-01

Background: Dysregulation of iron homeostasis is implicated in the pathogenesis of Huntington’s disease. We have previously shown that increased iron intake in R6/2 HD neonatal mice, but not adult R6/2 HD mice potentiates disease outcomes at 12-weeks of age corresponding to advanced HD [Redox Biol. 2015;4 : 363–74]. However, whether these findings extend to other HD models is unknown. In particular, it is unclear if increased neonatal iron intake can promote neurodegeneration in mouse HD models where disease onset is delayed to mid-adult life. Objective: To determine if increased dietary iron intake in neonatal and adult life-stages potentiates HD in the slowly progressive YAC128 HD mouse model. Methods: Female neonatal mice were supplemented daily from days 10–17 with 120μg/g body weight of carbonyl iron. Adult mice were provided diets containing low (50 ppm), medium (150 ppm) and high (500 ppm) iron concentrations from 2-months of age. HD progression was determined using behavioral, brain morphometric and biochemical approaches. Results: Neonatal-iron supplemented YAC128 HD mice had significantly lower striatal volumes and striatal neuronal cell body volumes as compared to control HD mice at 1-year of age. Neonatal-iron supplementation of HD mice had no effect on rota-rod motor endurance and brain iron or glutathione status. Adult iron intake level had no effect on HD progression. YAC128 HD mice had altered peripheral responses to iron intake compared to iron-matched wild-type controls. Conclusions: Female YAC128 HD mice supplemented with nutritionally-relevant levels of iron as neonates demonstrate increased striatal degeneration 1-year later. PMID:27079948

Histomorphometric Parameters of the Growth Plate and Trabecular Bone in Wild-Type and Trefoil Factor Family 3 (Tff3)-Deficient Mice Analyzed by Free and Open-Source Image Processing Software.

PubMed

Bijelić, Nikola; Belovari, Tatjana; Stolnik, Dunja; Lovrić, Ivana; Baus Lončar, Mirela

2017-08-01

Trefoil factor family 3 (Tff3) peptide is present during intrauterine endochondral ossification in mice, and its deficiency affects cancellous bone quality in secondary ossification centers of mouse tibiae. The aim of this study was to quantitatively analyze parameters describing the growth plate and primary ossification centers in tibiae of 1-month-old wild-type and Tff3 knock-out mice (n=5 per genotype) by using free and open-source software. Digital photographs of the growth plates and trabecular bone were processed by open-source computer programs GIMP and FIJI. Histomorphometric parameters were calculated using measurements made with FIJI. Tff3 knock-out mice had significantly smaller trabecular number and significantly larger trabecular separation. Trabecular bone volume, trabecular bone surface, and trabecular thickness showed no significant difference between the two groups. Although such histomorphological differences were found in the cancellous bone structure, no significant differences were found in the epiphyseal plate histomorphology. Tff3 peptide probably has an effect on the formation and quality of the cancellous bone in the primary ossification centers, but not through disrupting the epiphyseal plate morphology. This work emphasizes the benefits of using free and open-source programs for morphological studies in life sciences.

Involvement of substance P in the antinociceptive effect of botulinum toxin type A: Evidence from knockout mice.

PubMed

Matak, Ivica; Tékus, Valéria; Bölcskei, Kata; Lacković, Zdravko; Helyes, Zsuzsanna

2017-09-01

The antinociceptive action of botulinum toxin type A (BoNT/A) has been demonstrated in behavioral animal studies and clinical settings. It was shown that this effect is associated with toxin activity in CNS, however, the mechanism is not fully understood. Substance P (SP) is one of the dominant neurotransmitters in primary afferent neurons transmitting pain and itch. Thus, here we examined association of SP-mediated transmission and BoNT/A antinociceptive action by employing gene knockouts. Antinociceptive activity of intraplantarly (i.pl.) injected BoNT/A was examined in mice lacking the gene encoding for SP/neurokinin A (tac1 -/- ) or SP-preferred receptor neurokinin 1 (tac1r -/- ), compared to control C57Bl/6J wild type animals. BoNT/A action was assessed in inflammatory pain induced by formalin and CFA, and neuropathic pain induced by partial sciatic nerve ligation. BoNT/A activity in CNS was examined by c-Fos and BoNT/A-cleaved SNAP-25 immunohistochemistry. In wild type mice, acute (formalin-evoked) and chronic pain (neuropathic and inflammatory) was reduced by peripherally injected BoNT/A. In tac1 -/- and tac1r -/- knockout mice, BoNT/A exerted no analgesic effect. In control animals BoNT/A reduced the formalin-evoked c-Fos expression in lumbar dorsal horn, while in knockout mice the c-Fos expression was not reduced. After peripheral toxin injection, cleaved SNAP-25 occurred in lumbar dorsal horn in all animal genotypes. BoNT/A antinociceptive activity is absent in animals lacking the SP and neurokinin 1 receptor encoding genes, in spite of presence of toxin's enzymatic activity in central sensory regions. Thus, we conclude that the integrity of SP-ergic system is necessary for the antinociceptive activity of BoNT/A. Copyright © 2017. Published by Elsevier Ltd.

Circadian rhythms in heart rate, motility, and body temperature of wild-type C57 and eNOS knock-out mice under light-dark, free-run, and after time zone transition.

PubMed

Arraj, M; Lemmer, B

2006-01-01

The nitric oxide (NO) system is involved in the regulation of the cardiovascular system in controlling central and peripheral vascular tone and cardiac functions. It was the aim of this study to investigate in wild-type C57BL/6 and endothelial nitric oxide synthase (eNOS) knock-out mice (eNOS-/-) the contribution of NO on the circadian rhythms in heart rate (HR), motility (motor activity [MA]), and body temperature (BT) under various environmental conditions. Experiments were performed in 12:12 h of a light:dark cycle (LD), under free-run in total darkness (DD), and after a phase delay shift of the LD cycle by -6 h (i.e., under simulation of a westward time zone transition). All parameters were monitored by radiotelemetry in freely moving mice. In LD, no significant differences in the rhythms of HR and MA were observed between the two strains of mice. BT, however, was significantly lower during the light phase in eNOS-/- mice, resulting in a significantly greater amplitude. The period of the free-running rhythm in DD was slightly shorter for all variables, though not significant. In general, rhythmicity was greater in eNOS-/- than in C57 mice both in LD and DD. After a delay shift of the LD cycle, HR and BT were resynchronized to the new LD schedule within 5-6 days, and resynchronization of MA occurred within 2-3 days. The results in telemetrically instrumented mice show that complete knock-out of the endothelial NO system--though expressed in the suprachiasmatic nuclei and in peripheral tissues--did not affect the circadian organization of heart rate and motility. The circadian regulation of the body temperature was slightly affected in eNOS-/- mice.

Inhibition of Activin Receptor Type IIB Increases Strength and Lifespan in Myotubularin-Deficient Mice

PubMed Central

Lawlor, Michael W.; Read, Benjamin P.; Edelstein, Rachel; Yang, Nicole; Pierson, Christopher R.; Stein, Matthew J.; Wermer-Colan, Ariana; Buj-Bello, Anna; Lachey, Jennifer L.; Seehra, Jasbir S.; Beggs, Alan H.

2011-01-01

X-linked myotubular myopathy (XLMTM) is a congenital disorder caused by deficiency of the lipid phosphatase, myotubularin. Patients with XLMTM often have severe perinatal weakness that requires mechanical ventilation to prevent death from respiratory failure. Muscle biopsy specimens from patients with XLMTM exhibit small myofibers with central nuclei and central aggregations of organelles in many cells. It was postulated that therapeutically increasing muscle fiber size would cause symptomatic improvement in myotubularin deficiency. Recent studies have elucidated an important role for the activin-receptor type IIB (ActRIIB) in regulation of muscle growth and have demonstrated that ActRIIB inhibition results in significant muscle hypertrophy. To evaluate whether promoting muscle hypertrophy can attenuate symptoms resulting from myotubularin deficiency, the effect of ActRIIB-mFC treatment was determined in myotubularin-deficient (Mtm1δ4) mice. Compared with wild-type mice, untreated Mtm1δ4 mice have decreased body weight, skeletal muscle hypotrophy, and reduced survival. Treatment of Mtm1δ4 mice with ActRIIB-mFC produced a 17% extension of lifespan, with transient increases in weight, forelimb grip strength, and myofiber size. Pathologic analysis of Mtm1δ4 mice during treatment revealed that ActRIIB-mFC produced marked hypertrophy restricted to type 2b myofibers, which suggests that oxidative fibers in Mtm1δ4 animals are incapable of a hypertrophic response in this setting. These results support ActRIIB-mFC as an effective treatment for the weakness observed in myotubularin deficiency. PMID:21281811

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

Nuclei pulposi formation from the embryonic notochord occurs normally in GDF5-deficient mice

PubMed Central

Maier, Jennifer A.; Harfe, Brian D.

2011-01-01

Study Design The transition of the mouse embryonic notochord into nuclei pulposi was determined (“fate mapped”) in vivo in GDF-5 null mice using the Shhcre and R26R alleles. Objective To determine if abnormal nuclei pulposi formation from the embryonic notochord was responsible for defects present in adult nuclei pulposi of Gdf-5 null mice. Summary of Background Data The development, maintenance, and degeneration of the intervertebral disc are not understood. Previously, we demonstrated that all cells in the adult nucleus pulposus of normal mice are derived from the embryonic notochord. Gdf-5 null mice have been reported to contain intervertebral discs in which the nucleus pulposus is abnormal. It is currently unclear if disc defects in Gdf-5 null mice arise during the formation of nuclei pulposi from the notochord during embryogenesis or resulted from progressive postnatal degeneration of nuclei pulposi. Methods Gdf-5 mRNA expression was examined in the discs of wild-type embryos by RNA in situ hybridization to determine when and where this gene was expressed. To examine nucleus pulposus formation in Gdf-5 null mice, intervertebral discs in which embryonic notochord cells were marked were analyzed in newborn and 24 week old mice. Results Our Gdf-5 mRNA in situ experiments determined that this gene is localized to the annulus fibrosus and not the nucleus pulposus in mouse embryos. Notochord fate mapping experiments revealed that notochord cells in Gdf-5 null mice correctly form nuclei pulposi. Conclusion Our data suggest that the defects reported in the nucleus pulposus of adult Gdf-5 null mice do not result from abnormal patterning of the embryonic notochord. The use of mouse alleles to mark cells that produce all cell types that reside in the adult nucleus pulposus will allow for a detailed examination of disc formation in other mouse mutants that have been reported to contain disc defects. PMID:21278629

[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.

Differential Regulation of Primary Afferent Input to Spinal Cord by Muscarinic Receptor Subtypes Delineated Using Knockout Mice*

PubMed Central

Chen, Shao-Rui; Chen, Hong; Yuan, Wei-Xiu; Wess, Jürgen; Pan, Hui-Lin

2014-01-01

Stimulation of muscarinic acetylcholine receptors (mAChRs) inhibits nociceptive transmission at the spinal level. However, it is unclear how each mAChR subtype regulates excitatory synaptic input from primary afferents. Here we examined excitatory postsynaptic currents (EPSCs) of dorsal horn neurons evoked by dorsal root stimulation in spinal cord slices from wild-type and mAChR subtype knock-out (KO) mice. In wild-type mice, mAChR activation with oxotremorine-M decreased the amplitude of monosynaptic EPSCs in ∼67% of neurons but increased it in ∼10% of neurons. The inhibitory effect of oxotremorine-M was attenuated by the M2/M4 antagonist himbacine in the majority of neurons, and the remaining inhibition was abolished by group II/III metabotropic glutamate receptor (mGluR) antagonists in wild-type mice. In M2/M4 double-KO mice, oxotremorine-M inhibited monosynaptic EPSCs in significantly fewer neurons (∼26%) and increased EPSCs in significantly more neurons (33%) compared with wild-type mice. Blocking group II/III mGluRs eliminated the inhibitory effect of oxotremorine-M in M2/M4 double-KO mice. In M2 single-KO and M4 single-KO mice, himbacine still significantly reduced the inhibitory effect of oxotremorine-M. However, the inhibitory and potentiating effects of oxotremorine-M on EPSCs in M3 single-KO and M1/M3 double-KO mice were similar to those in wild-type mice. In M5 single-KO mice, oxotremorine-M failed to potentiate evoked EPSCs, and its inhibitory effect was abolished by himbacine. These findings indicate that activation of presynaptic M2 and M4 subtypes reduces glutamate release from primary afferents. Activation of the M5 subtype either directly increases primary afferent input or inhibits it through indirectly stimulating group II/III mGluRs. PMID:24695732

Aggravated brain damage after hypoxic ischemia in immature adenosine A2A knockout mice.

PubMed

Adén, Ulrika; Halldner, Linda; Lagercrantz, Hugo; Dalmau, Ishar; Ledent, Catherine; Fredholm, Bertil B

2003-03-01

Cerebral hypoxic ischemia (HI) is an important cause of brain injury in the newborn infant. Adenosine is believed to protect against HI brain damage. However, the roles of the different adenosine receptors are unclear, particularly in young animals. We examined the role of adenosine A2A receptors (A2AR) using 7-day-old A2A knockout (A2AR(-/-)) mice in a model of HI. HI was induced in 7-day-old CD1 mice by exposure to 8% oxygen for 30 minutes after occlusion of the left common carotid artery. The resulting unilateral focal lesion was evaluated with the use of histopathological scoring and measurements of residual brain areas at 5 days, 3 weeks, and 3 months after HI. Behavioral evaluation of brain injury by locomotor activity, rotarod, and beam-walking test was made 3 weeks and 3 months after HI. Cortical cerebral blood flow, assessed by laser-Doppler flowmetry, and rectal temperature were measured during HI. Reduction in cortical cerebral blood flow during HI and rectal temperature did not differ between wild-type (A2AR(+/+)) and knockout mice. In the A2AR(-/-) animals, brain injury was aggravated compared with wild-type mice. The A2AR(-/-) mice subjected to HI displayed increased forward locomotion and impaired rotarod performance in adulthood compared with A2AR(+/+) mice subjected to HI, whereas beam-walking performance was similarly defective in both groups. These results suggest that, in contrast to the situation in adult animals, A2AR play an important protective role in neonatal HI brain injury.

Ablation of neurons expressing melanin-concentrating hormone (MCH) in adult mice improves glucose tolerance independent of MCH signaling.

PubMed

Whiddon, Benjamin B; Palmiter, Richard D

2013-01-30

Melanin-concentrating hormone (MCH)-expressing neurons have been ascribed many roles based on studies of MCH-deficient mice. However, MCH neurons express other neurotransmitters, including GABA, nesfatin, and cocaine-amphetamine-regulated transcript. The importance of these other signaling molecules made by MCH neurons remains incompletely characterized. To determine the roles of MCH neurons in vivo, we targeted expression of the human diphtheria toxin receptor (DTR) to the gene for MCH (Pmch). Within 2 weeks of diphtheria toxin injection, heterozygous Pmch(DTR/+) mice lost 98% of their MCH neurons. These mice became lean but ate normally and were hyperactive, especially during a fast. They also responded abnormally to psychostimulants. For these phenotypes, ablation of MCH neurons recapitulated knock-out of MCH, so MCH appears to be the critical neuromodulator released by these neurons. In contrast, MCH-neuron-ablated mice showed improved glucose tolerance when compared with MCH-deficient mutant mice and wild-type mice. We conclude that MCH neurons regulate glucose tolerance through signaling molecules other than MCH.

Disruption of the Gardos channel (KCa3.1) in mice causes subtle erythrocyte macrocytosis and progressive splenomegaly.

PubMed

Grgic, Ivica; Kaistha, Brajesh P; Paschen, Steffen; Kaistha, Anuradha; Busch, Christoph; Si, Han; Köhler, Kernt; Elsässer, Hans-Peter; Hoyer, Joachim; Köhler, Ralf

2009-06-01

Gardos channel, the erythrocyte Ca(2+)-activated K(+) channel (K(Ca)3.1), is considered a major regulator of red blood cell (RBC) volume by mediating efflux of potassium and thus cell dehydration and shrinkage. However, the functional importance of K(Ca)3.1 in RBC in vivo is incompletely understood. Here, we used K(Ca)3.1(-/-)-mice to investigate the consequences of K(Ca)3.1 deficiency for RBC indices, functions, and sequestration. RBCs of K(Ca)3.1(-/-)-mice of all ages were mildly macrocytic but their biconcave appearance being preserved. RBC number, total hemoglobin, and hematocrit were unchanged in the adult K(Ca)3.1(-/-)-mice and increased in the premature K(Ca)3.1(-/-)-mice. Filterability, Ca(2+)-dependent volume decrease and osmotic tolerance of RBCs lacking K(Ca)3.1 were noticeably reduced when compared to RBC of wild-type littermates. Deformability to increasing shear stress was unchanged. Strikingly, K(Ca)3.1(-/-)-mice developed progressive splenomegaly which was considerable ( approximately 200% of controls) in the >6-month-old mice and was paralleled by increased iron deposition in the aged mice presumably as a consequence of enhanced RBC sequestration. Daily injections of the K(Ca)3.1-blocker TRAM-34 (120 mg/kg) also produced mild splenomegaly in wild-type mice. We conclude that genetic deficit of erythroid K(Ca)3.1 causes mild RBC macrocytosis, presumably leading to reduced filterability, and impairs volume regulation. These RBC defects result in mild but progressive splenomegaly.

Enhanced susceptibility to acute pneumococcal otitis media in mice deficient in complement C1qa, factor B, and factor B/C2.

PubMed

Tong, Hua Hua; Li, Yong Xing; Stahl, Gregory L; Thurman, Joshua M

2010-03-01

To define the roles of specific complement activation pathways in host defense against Streptococcus pneumoniae in acute otitis media (AOM), we investigated the susceptibility to AOM in mice deficient in complement factor B and C2 (Bf/C2(-/)(-)), C1qa (C1qa(-/)(-)), and factor B (Bf(-)(/)(-)). Bacterial titers of both S. pneumoniae serotype 6A and 14 in the middle ear lavage fluid samples from Bf/C2(-/)(-), Bf(-)(/)(-), and C1qa(-/)(-) mice were significantly higher than in samples from wild-type mice 24 h after transtympanical infection (P < 0.05) and remained persistently higher in samples from Bf/C2(-/)(-) mice than in samples from wild-type mice. Bacteremia occurred in Bf/C2(-/)(-), Bf(-)(/)(-), and C1qa(-/)(-) mice infected with both strains, but not in wild-type mice. Recruitment of inflammatory cells was paralleled by enhanced production of inflammatory mediators in the middle ear lavage samples from Bf/C2(-/)(-) mice. C3b deposition on both strains was greatest for sera obtained from wild-type mice, followed by C1qa(-)(/)(-) and Bf(-)(/)(-) mice, and least for Bf/C2(-)(/)(-) mice. Opsonophagocytosis and whole-blood killing capacity of both strains were significantly decreased in the presence of sera or whole blood from complement-deficient mice compared to wild-type mice. These findings indicate that both the classical and alternative complement pathways are critical for middle ear immune defense against S. pneumoniae. The reduced capacity of complement-mediated opsonization and phagocytosis in the complement-deficient mice appears to be responsible for the impaired clearance of S. pneumoniae from the middle ear and dissemination to the bloodstream during AOM.

Reduced 4-Aminobiphenyl-Induced Liver Tumorigenicity but not DNA Damage in Arylamine N-Acetyltransferase Null Mice

PubMed Central

Sugamori, Kim S.; Brenneman, Debbie; Sanchez, Otto; Doll, Mark A.; Hein, David W.; Pierce, William M.; Grant, Denis M.

2012-01-01

The aromatic amine 4-aminobiphenyl (ABP) is a liver procarcinogen in mice, requiring enzymatic bioactivation to exert its tumorigenic effect. To assess the role of arylamine N-acetyltransferase (NAT)-dependent acetylation capacity in the risk for ABP-induced liver tumors, we compared 1-year liver tumor incidence following the postnatal exposure of wild-type and NAT-deficient Nat1/2(−/−) mice to ABP. At an ABP exposure of 1200 nmoles, male Nat1/2(−/−) mice had a liver tumor incidence of 36% compared to 69% in wild-type males, and at 600 nmoles there was a complete absence of tumors compared to 60% in wild-type mice. Only one female wild-type mouse had a tumor using this exposure protocol. However, levels of N-deoxyguanosin-8-yl-ABP-DNA adducts did not correlate with either the strain or sex differences in tumor incidence. These results suggest that female sex and NAT deficiency reduce risk for ABP-induced liver tumors, but by mechanisms unrelated to differences in DNA-damaging events. PMID:22193722

Comprehensive Behavioral Analysis of Activating Transcription Factor 5-Deficient Mice

PubMed Central

Umemura, Mariko; Ogura, Tae; Matsuzaki, Ayako; Nakano, Haruo; Takao, Keizo; Miyakawa, Tsuyoshi; Takahashi, Yuji

2017-01-01

Activating transcription factor 5 (ATF5) is a member of the CREB/ATF family of basic leucine zipper transcription factors. We previously reported that ATF5-deficient (ATF5-/-) mice demonstrated abnormal olfactory bulb development due to impaired interneuron supply. Furthermore, ATF5-/- mice were less aggressive than ATF5+/+ mice. Although ATF5 is widely expressed in the brain, and involved in the regulation of proliferation and development of neurons, the physiological role of ATF5 in the higher brain remains unknown. Our objective was to investigate the physiological role of ATF5 in the higher brain. We performed a comprehensive behavioral analysis using ATF5-/- mice and wild type littermates. ATF5-/- mice exhibited abnormal locomotor activity in the open field test. They also exhibited abnormal anxiety-like behavior in the light/dark transition test and open field test. Furthermore, ATF5-/- mice displayed reduced social interaction in the Crawley’s social interaction test and increased pain sensitivity in the hot plate test compared with wild type. Finally, behavioral flexibility was reduced in the T-maze test in ATF5-/- mice compared with wild type. In addition, we demonstrated that ATF5-/- mice display disturbances of monoamine neurotransmitter levels in several brain regions. These results indicate that ATF5 deficiency elicits abnormal behaviors and the disturbance of monoamine neurotransmitter levels in the brain. The behavioral abnormalities of ATF5-/- mice may be due to the disturbance of monoamine levels. Taken together, these findings suggest that ATF5-/- mice may be a unique animal model of some psychiatric disorders. PMID:28744205

In vitro re-expression of the aryl hydrocarbon receptor (Ahr) in cultured Ahr-deficient mouse antral follicles partially restores the phenotype to that of cultured wild-type mouse follicles.

PubMed

Ziv-Gal, A; Gao, L; Karman, B N; Flaws, J A

2015-03-01

The aryl hydrocarbon receptor (AHR) mediates the toxic effects of various endocrine disrupting chemicals. In female mice, global deletion of the Ahr (AhrKO) results in slow growth of ovarian antral follicles. No studies, however, have examined whether injection of the Ahr restores the phenotypes of cultured AhrKO ovarian antral follicles to wild-type levels. We developed a system to construct a recombinant adenovirus containing the Ahr to re-express the Ahr in AhrKO granulosa cells and whole antral follicles. We then compared follicle growth and levels of factors in the AHR signaling pathway (Ahr, Ahrr, Cyp1a1, and Cyp1b1) in wild-type, AhrKO, and Ahr re-expressed follicles. Further, we compared the response to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) in wild-type, AhrKO, and Ahr re-expressed follicles. Ahr injection into AhrKO follicles partially restored their growth pattern to wild-type levels. Further, Ahr re-expressed follicles had significantly higher levels of Ahr, Ahrr, Cyp1a1, and Cyp1b1 compared to wild-type follicles. Upon TCDD treatment, only Cyp1a1 levels were significantly higher in Ahr re-expressed follicles compared to the levels in wild-type follicles. Our system of re-expression of the Ahr partially restores follicle growth and transcript levels of factors in the AHR signaling pathway to wild-type levels. Copyright © 2014 Elsevier Ltd. All rights reserved.

Production of Prnp-/- goats by gene targeting in adult fibroblasts.

PubMed

Zhu, Caihong; Li, Bei; Yu, Guohua; Chen, Jianquan; Yu, Huiqing; Chen, Juan; Xu, Xujun; Wu, Youbing; Zhang, Aimin; Cheng, Guoxiang

2009-04-01

Homozygous mice devoid of functional Prnp are resistant to scrapie and prion propagation, but heterozygous mice for Prnp disruption still suffer from prion disease and prion deposition. We have previously generated heterozygous cloned goats with one allele of Prnp functional disruption. To obtain goats with both alleles of Prnp be disrupted which would be resistant to scrapie completely, a second-round gene targeting was applied to disrupt the wild type allele of Prnp in the heterozygous goats. By second-round gene targeting, we successfully disrupted the wild type allele of Prnp in primary Prnp (+/-) goat skin fibroblasts and obtained a Prnp (-/-) cell line without Prnp expression. This is the first report on successful targeting modification in primary adult somatic cells of animals. These cells were used as nuclear donors for somatic cell cloning to produce Prnp (-/-) goats. A total of 57 morulae or blastocytes developed from the reconstructed embryos were transferred to 31 recipients, which produced 7 pregnancies at day 35. At 73 days of gestation, we obtained one cloned fetus with Prnp (-/-) genotype. Our research not only indicated that multiple genetic modifications could be accomplished by multi-round gene targeting in primary somatic cells, but also provided strong evidence that gene targeting in adult cells other than fetal cells could be applied to introduce precise genetic modifications in animals without destroying the embryos.

Loss of the type I interferon pathway increases vulnerability of mice to genital herpes simplex virus 2 infection.

PubMed

Conrady, Christopher D; Halford, William P; Carr, Daniel J J

2011-02-01

The mouse model of genital herpes relies on medoxyprogesterone treatment of female mice to render the vaginal lumen susceptible to inoculation with herpes simplex virus 2 (HSV-2). In the present study, we report that mice deficient in the A1 chain of the type I interferon receptor (CD118(-/-)) are susceptible to HSV-2 in the absence of medroxyprogesterone preconditioning. In the absence of hormone pretreatment, 2,000 PFU of a clinical isolate of HSV-2 was sufficient to establish a productive infection in the vagina of 75% ± 17% and in the spinal cord of 71% ± 14% of CD118(-/-) mice, whereas the same dose of HSV-2 replicated to detectable levels in only 13% ± 13% of vaginal samples and 0% of spinal cord samples from wild-type mice, as determined at day 5 postinfection. The susceptibility to HSV-2 infection in the CD118(-/-) mice was associated with a significant reduction in the infiltration of HSV-specific cytotoxic T lymphocytes into the vaginal tissue, the local production of gamma interferon (IFN-γ), and the expression of T cell-recruiting chemokines CCL5, CXCL9, and CXCL10. Collectively, the results underscore the significant contribution of type I IFNs in resistance to genital HSV-2 infection.

Antidepressive and BDNF effects of enriched environment treatment across ages in mice lacking BDNF expression through promoter IV

PubMed Central

Jha, S; Dong, B E; Xue, Y; Delotterie, D F; Vail, M G; Sakata, K

2016-01-01

Reduced promoter IV-driven expression of brain-derived neurotrophic factor (BDNF) is implicated in stress and major depression. We previously reported that defective promoter IV (KIV) caused depression-like behavior in young adult mice, which was reversed more effectively by enriched environment treatment (EET) than antidepressants. The effects of promoter IV-BDNF deficiency and EET over the life stages remain unknown. Since early-life development (ED) involves dynamic epigenetic processes, we hypothesized that EET during ED would provide maximum antidepressive effects that would persist later in life due to enhanced, long-lasting BDNF induction. We tested this hypothesis by determining EET effects across three life stages: ED (0–2 months), young adult (2–4 months), and old adult (12–14 months). KIV mice at all life stages showed depression-like behavior in the open-field and tail-suspension tests compared with wild-type mice. Two months of EET reduced depression-like behavior in ED and young adult, but not old adult mice, with the largest effect in ED KIV mice. This effect lasted for 1 month after discontinuance of EET only in ED mice. BDNF protein induction by EET in the hippocampus and frontal cortex was also the largest in ED mice and persisted only in the hippocampus of ED KIV mice after discontinuance of EET. No gender-specific effects were observed. The results suggest that defective promoter IV causes depression-like behavior, regardless of age and gender, and that EET during ED is particularly beneficial to individuals with promoter IV-BDNF deficiency, while additional treatment may be needed for older adults. PMID:27648918

Progressive Retinal Degeneration and Accumulation of Autofluorescent Lipopigments in Progranulin Deficient Mice

PubMed Central

Hafler, Brian P.; Klein, Zoe A.; Zhou, Z. Jimmy; Strittmatter, Stephen M.

2014-01-01

Prior investigations have shown that patients with neuronal ceroid lipofuscinosis (NCL) develop neurodegeneration characterized by vision loss, motor dysfunction, seizures, and often early death. Neuropathological analysis of patients with NCL shows accumulation of intracellular autofluorescent storage material, lipopigment, throughout neurons in the central nervous system including in the retina. A recent study of a sibling pair with adult onset NCL and retinal degeneration showed linkage to the region of the progranulin (GRN) locus and a homozygous mutation was demonstrated in GRN. In particular, the sibling pair with a mutation in GRN developed retinal degeneration and optic atrophy. This locus for this form of adult onset neuronal ceroid lipofuscinosis was designated neuronal ceroid lipofuscinosis-11 (CLN11). Based on these clinical observations, we wished to determine whether Grn-null mice develop accumulation of autofluorescent particles and retinal degeneration. Retinas of both wild-type and Progranulin deficient mice were examined by immunostaining and autofluorescence. Accumulation of autofluorescent material was present in Progranulin deficient mice at 12 months. Degeneration of multiple classes of neurons including photoreceptors and retinal ganglion cells was noted in mice at 12 and 18 months. Our data shows that Grn−/− mice develop degenerative pathology similar to features of human CLN11. PMID:25234724

Long-term patterns of immune investment by wild deer mice infected with Sin Nombre virus.

PubMed

Lehmer, Erin M; Jones, Jeremy D; Bego, Mariana G; Varner, Johanna M; Jeor, Stephen St; Clay, Christine A; Dearing, M Denise

2010-01-01

Immunocompetence of animals fluctuates seasonally, However, there is little consensus on the cause of these fluctuations. Some studies have suggested that these patterns are influenced by changes in reproductive condition, whereas others have suggested that differences result from seasonal variations in energy expenditures. The objective of our study was to examine these contrasting views of immunity by evaluating seasonal patterns of immune response and reproduction in wild populations of deer mice Peromyscus maniculatus exposed to Sin Nombre virus (SNV). Over three consecutive fall (September, October, November) and three consecutive spring (March, April, May) sampling periods, we used titration enzyme-linked immunosorbent assay (ELISA) to quantify virus-specific antibody production in 48 deer mice infected with SNV. Levels of reproductive hormones were quantified using ELISA. SNV antibody titers reached their lowest level during November (geometric mean titer [GMT] = 420) and their highest levels during September (GMT = 5,545) and May (GMT = 3,582), suggesting that the immune response of deer mice to SNV has seasonal patterns. The seeming decrease in antibody titer over winter coupled with the consistency in body masses suggests that during winter, immunocompetence may be compromised to offset the energetic costs of maintenance functions, including those associated with maintaining body mass. Deer mice showed distinct sex-based differences in SNV antibody production, with males producing higher antibody titers (GMT = 3,333) than females (GMT = 1,477). Levels of reproductive hormones do not appear to influence antibody production in either males or females, as there was no correlation between estradiol concentrations and SNV antibody titer in female deer mice (r² = 0.26), nor was there a significant relationship between levels of testosterone and SNV antibody titers in males (r² = 0.28). Collectively, this study demonstrates that immunocompetence of wild deer

Oral and dental conditions in adult African wild dog skulls: a preliminary report.

PubMed

Steenkamp, G; Gorrel, C

1999-06-01

Skulls of 29 adult African wild dogs (Lycaon pictus) originating from museum collections were examined for evidence of oral pathology. A wide variety of conditions similar to those seen in the domestic dog were detected. Although other reports suggest that captive African wild dogs suffer more extensively from dental disease than those in the wild, we conclude that these wild carnivores suffer from the same oral diseases as their domestic relatives, suggesting that a natural diet does not protect against these diseases. As the African wild dog is threatened by extinction, further investigation of the incidence and development of oral and dental disease in this species may be of value. Preventive measures could be instituted leading to improved health for those held in captivity.

Differential regulation of cell proliferation in neurogenic zones in mice lacking cystine transport by xCT

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

Liu, Richard R.; Brown, Craig E.; Brain Research Center, University of British Columbia, Vancouver, BC, V6T 1Z3

2007-12-21

The cystine/glutamate exchanger (xCT) supplies intracellular cyst(e)ine for the production of glutathione, a major cellular anti-oxidant. xCT is enriched in brain regions associated with neurogenesis. Previous studies have shown that the malfunction of this protein greatly attenuates cell proliferation in vitro and is associated with brain atrophy in vivo. Using mice that are homozygous for a function-blocking deletion in xCT (Sut mice), we examined in vivo the role of xCT in cell proliferation in neurogenic regions of the subventricular zone (SVZ) and denate gyrus (DG) in the adult brain. Our results indicate that a high level of cellular proliferation inmore » the adult brain persists even in the absence of functional xCT. Furthermore, in both young adult and middle-aged mice (3 and 11 months old), rates of SVZ cell proliferation were comparable between Sut and wild-type controls, although there was trend towards reduced proliferation in Sut mice (12% and 9% reduction, respectively). To our surprise, rates of cell proliferation in the DG were elevated in both 3- and 11-month-old Sut mice relative to controls (22% and 28% increase, respectively). These results demonstrate that xCT expression plays a role in regulating cellular proliferation in the DG, but not the SVZ of adult mice. Furthermore, unlike previous in vitro studies, our in vivo observations clearly indicate that xCT is not essential for ongoing cellular proliferation.« less

A cell cycle-independent, conditional gene inactivation strategy for differentially tagging wild-type and mutant cells.

PubMed

Nagarkar-Jaiswal, Sonal; Manivannan, Sathiya N; Zuo, Zhongyuan; Bellen, Hugo J

2017-05-31

Here, we describe a novel method based on intronic MiMIC insertions described in Nagarkar-Jaiswal et al. (2015) to perform conditional gene inactivation in Drosophila . Mosaic analysis in Drosophila cannot be easily performed in post-mitotic cells. We therefore, therefore, developed Flip-Flop, a flippase -dependent in vivo cassette-inversion method that marks wild-type cells with the endogenous EGFP-tagged protein, whereas mutant cells are marked with mCherry upon inversion. We document the ease and usefulness of this strategy in differential tagging of wild-type and mutant cells in mosaics. We use this approach to phenotypically characterize the loss of SNF4Aγ , encoding the γ subunit of the AMP Kinase complex. The Flip-Flop method is efficient and reliable, and permits conditional gene inactivation based on both spatial and temporal cues, in a cell cycle-, and developmental stage-independent fashion, creating a platform for systematic screens of gene function in developing and adult flies with unprecedented detail.

Leptin Increases Striatal Dopamine D2 Receptor Binding in Leptin-Deficient Obese (ob/ob) Mice

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

Pfaffly, J.; Michaelides, M.; Wang, G-J.

2010-06-01

Peripheral and central leptin administration have been shown to mediate central dopamine (DA) signaling. Leptin-receptor deficient rodents show decreased DA D2 receptor (D2R) binding in striatum and unique DA profiles compared to controls. Leptin-deficient mice show increased DA activity in reward-related brain regions. The objective of this study was to examine whether basal D2R-binding differences contribute to the phenotypic behaviors of leptin-deficient ob/ob mice, and whether D2R binding is altered in response to peripheral leptin treatment in these mice. Leptin decreased body weight, food intake, and plasma insulin concentration in ob/ob mice but not in wild-type mice. Basal striatal D2Rmore » binding (measured with autoradiography [{sup 3}H] spiperone) did not differ between ob/ob and wild-type mice but the response to leptin did. In wild-type mice, leptin decreased striatal D2R binding, whereas, in ob/ob mice, leptin increased D2R binding. Our findings provide further evidence that leptin modulates D2R expression in striatum and that these effects are genotype/phenotype dependent.« less

fat-1 mice prevent high-fat plus high-sugar diet-induced non-alcoholic fatty liver disease.

PubMed

Guo, Xiao-Fei; Gao, Jin-Long; Li, Jiao-Mei; Li, Duo

2017-11-15

High-fat and high-sugar (HFS) diets have been suggested to play a causal role in the pathogenesis of non-alcoholic fatty liver disease (NAFLD). This study aimed to investigate whether fat-1 transgenic mice with a higher tissue content of n-3 polyunsaturated fatty acids (PUFAs) could prevent HFS diet-induced NAFLD, compared with wild-type mice. The fat-1 and wild-type littermates had free access to a 15% fructose solution plus high-fat diet, a 15% glucose solution plus high-fat diet, or a 15% sucrose solution plus high-fat diet, respectively. Caloric intake, weight gain, biochemical parameters, histology, and gene and protein expression levels were measured after 8 weeks of intervention. Liquid intake in glucose- or sucrose-fed mice was about 2-fold compared with that in fructose-fed mice. The wild-type mice given glucose showed the highest total caloric intake and weight gain compared to the other groups. The serum concentrations of total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), and alanine transaminase (ALT) were significantly lowered in fat-1 groups compared with their paired wild-type groups. Histological analysis showed that the wild-type groups fed the HFS diets developed hepatic lipid accumulation and steatosis, compared with the fat-1 groups. The gene and protein expression levels involved in fatty acid synthesis and the toll-like receptor (TLR)-4 signaling pathway were significantly inhibited in the fat-1 groups compared with the wild-type groups. The endogenously synthesized n-3 PUFAs of the three fat-1 groups, which inhibit fatty acid synthesis and the TLR-4 signaling pathway, prevent HFS diet-induced NAFLD.

Wild-Type Male Offspring of fmr-1+/− Mothers Exhibit Characteristics of the Fragile X Phenotype

PubMed Central

Zupan, Bojana; Toth, Miklos

2009-01-01

Fragile X syndrome is an X-linked disorder caused by the inactivation of the FMR-1 gene with symptoms ranging from impaired cognitive functions to seizures, anxiety, sensory abnormalities, and hyperactivity. Males are more severely affected than heterozygote (H) females, who, as carriers, have a 50% chance of transmitting the mutated allele in each pregnancy. fmr-1 knockout (KO) mice reproduce fragile X symptoms, including hyperactivity, seizures, and abnormal sensory processing. In contrast to the expectation that wild-type (WT) males born to H (fmr-1+/−) mothers (H> WT) are behaviorally normal and indistinguishable from WT males born to WT mothers (WT> WT); here, we show that H> WT offspring are more active than WT> WT offspring and that their hyperactivity is similar to male KO mice born to H or KO (fmr-1−/−) mothers (H> KO/KO> KO). H> WT mice, however, do not exhibit seizures or abnormal sensory processing. Consistent with their hyperactivity, the effect of the D2 agonist quinpirole is reduced in H> WT as well as in H> KO and KO> KO mice compared to WT> WT offspring, suggesting a diminished feedback inhibition of dopamine release. Our data indicate that some aspects of hyperactivity and associated dopaminergic changes in ‘fragile X’ mice are a maternal fmr-1 genotype rather than an offspring fmr-1 genotype effect. PMID:18172434

Epsilon toxin is essential for the virulence of Clostridium perfringens type D infection in sheep, goats, and mice.

PubMed

Garcia, J P; Adams, V; Beingesser, J; Hughes, M L; Poon, R; Lyras, D; Hill, A; McClane, B A; Rood, J I; Uzal, F A

2013-07-01

Clostridium perfringens type D causes disease in sheep, goats, and other ruminants. Type D isolates produce, at minimum, alpha and epsilon (ETX) toxins, but some express up to five different toxins, raising questions about which toxins are necessary for the virulence of these bacteria. We evaluated the contribution of ETX to C. perfringens type D pathogenicity in an intraduodenal challenge model in sheep, goats, and mice using a virulent C. perfringens type D wild-type strain (WT), an isogenic ETX null mutant (etx mutant), and a strain where the etx mutation has been reversed (etx complemented). All sheep and goats, and most mice, challenged with the WT isolate developed acute clinical disease followed by death in most cases. Sheep developed various gross and/or histological changes that included edema of brain, lungs, and heart as well as hydropericardium. Goats developed various effects, including necrotizing colitis, pulmonary edema, and hydropericardium. No significant gross or histological abnormalities were observed in any mice infected with the WT strain. All sheep, goats, and mice challenged with the isogenic etx mutant remained clinically healthy for ≥24 h, and no gross or histological abnormalities were observed in those animals. Complementation of etx knockout restored virulence; most goats, sheep, and mice receiving this complemented mutant developed clinical and pathological changes similar to those observed in WT-infected animals. These results indicate that ETX is necessary for type D isolates to induce disease, supporting a key role for this toxin in type D disease pathogenesis.