Modulation of neuroinflammation and pathology in the 5XFAD mouse model of Alzheimer's disease using a biased and selective beta-1 adrenergic receptor partial agonist.

PubMed

Ardestani, Pooneh Memar; Evans, Andrew K; Yi, Bitna; Nguyen, Tiffany; Coutellier, Laurence; Shamloo, Mehrdad

2017-04-01

Degeneration of noradrenergic neurons occurs at an early stage of Alzheimer's Disease (AD). The noradrenergic system regulates arousal and learning and memory, and has been implicated in regulating neuroinflammation. Loss of noradrenergic tone may underlie AD progression at many levels. We have previously shown that acute administration of a partial agonist of the beta-1 adrenergic receptor (ADRB1), xamoterol, restores behavioral deficits in a mouse model of AD. The current studies examined the effects of chronic low dose xamoterol on neuroinflammation, pathology, and behavior in the pathologically aggressive 5XFAD transgenic mouse model of AD. In vitro experiments in cells expressing human beta adrenergic receptors demonstrate that xamoterol is highly selective for ADRB1 and functionally biased for the cAMP over the β-arrestin pathway. Data demonstrate ADRB1-mediated attenuation of TNF-α production with xamoterol in primary rat microglia culture following LPS challenge. Finally, two independent cohorts of 5XFAD and control mice were administered xamoterol from approximately 4.0-6.5 or 7.0-9.5 months, were tested in an array of behavioral tasks, and brains were examined for evidence of neuroinflammation, and amyloid beta and tau pathology. Xamoterol reduced mRNA expression of neuroinflammatory markers (Iba1, CD74, CD14 and TGFβ) and immunohistochemical evidence for microgliosis and astrogliosis. Xamoterol reduced amyloid beta and tau pathology as measured by regional immunohistochemistry. Behavioral deficits were not observed for 5XFAD mice. In conclusion, chronic administration of a selective, functionally biased, partial agonist of ADRB1 is effective in reducing neuroinflammation and amyloid beta and tau pathology in the 5XFAD model of AD. Copyright © 2017 Elsevier Ltd. All rights reserved.

Acceleration and persistence of neurofibrillary pathology in a mouse model of tauopathy following anesthesia

PubMed Central

Planel, Emmanuel; Bretteville, Alexis; Liu, Li; Virag, Laszlo; Du, Angela L.; Yu, Wai Haung; Dickson, Dennis W.; Whittington, Robert A.; Duff, Karen E.

2009-01-01

Alzheimer’s disease and other tauopathies are characterized by the presence of intracellular neurofibrillary tangles composed of hyperphosphorylated, insoluble tau. General anesthesia has been shown to be associated with increased risk of Alzheimer’s disease, and we have previously demonstrated that anesthesia induces hypothermia, which leads to overt tau hyperphosphorylation in the brain of mice regardless of the anesthetic used. To investigate whether anesthesia enhances the long-term risk of developing pathological forms of tau, we exposed a mouse model with tauopathy to anesthesia and monitored the outcome at two time points—during anesthesia, or 1 wk after exposure. We found that exposure to isoflurane at clinically relevant doses led to increased levels of phospho-tau, increased insoluble, aggregated forms of tau, and detachment of tau from microtubules. Furthermore, levels of phospho-tau distributed in the neuropil, as well as in cell bodies increased. Interestingly, the level of insoluble tau was increased 1 wk following anesthesia, suggesting that anesthesia precipitates changes in the brain that provoke the later development of tauopathy. Overall, our results suggest that anesthesia-induced hypothermia could lead to an acceleration of tau pathology in vivo that could have significant clinical implications for patients with early stage, or overt neurofibrillary tangle pathology.—Planel, E., Bretteville, A., Liu, L., Virag, L., Du, A. L., Yu, W. Y., Dickson, D. W., Whittington, R. A., Duff, K. E. Acceleration and persistence of neurofibrillary pathology in a mouse model of tauopathy following anesthesia. PMID:19279139

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

PubMed

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

2015-01-01

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

Rational Design of Mouse Models for Cancer Research.

PubMed

Landgraf, Marietta; McGovern, Jacqui A; Friedl, Peter; Hutmacher, Dietmar W

2018-03-01

The laboratory mouse is widely considered as a valid and affordable model organism to study human disease. Attempts to improve the relevance of murine models for the investigation of human pathologies led to the development of various genetically engineered, xenograft and humanized mouse models. Nevertheless, most preclinical studies in mice suffer from insufficient predictive value when compared with cancer biology and therapy response of human patients. We propose an innovative strategy to improve the predictive power of preclinical cancer models. Combining (i) genomic, tissue engineering and regenerative medicine approaches for rational design of mouse models with (ii) rapid prototyping and computational benchmarking against human clinical data will enable fast and nonbiased validation of newly generated models. Copyright © 2017 Elsevier Ltd. All rights reserved.

Specific Disruption of Hippocampal Mossy Fiber Synapses in a Mouse Model of Familial Alzheimer's Disease

PubMed Central

Wilke, Scott A.; Raam, Tara; Antonios, Joseph K.; Bushong, Eric A.; Koo, Edward H.; Ellisman, Mark H.; Ghosh, Anirvan

2014-01-01

The earliest stages of Alzheimer's disease (AD) are characterized by deficits in memory and cognition indicating hippocampal pathology. While it is now recognized that synapse dysfunction precedes the hallmark pathological findings of AD, it is unclear if specific hippocampal synapses are particularly vulnerable. Since the mossy fiber (MF) synapse between dentate gyrus (DG) and CA3 regions underlies critical functions disrupted in AD, we utilized serial block-face electron microscopy (SBEM) to analyze MF microcircuitry in a mouse model of familial Alzheimer's disease (FAD). FAD mutant MF terminal complexes were severely disrupted compared to control – they were smaller, contacted fewer postsynaptic spines and had greater numbers of presynaptic filopodial processes. Multi-headed CA3 dendritic spines in the FAD mutant condition were reduced in complexity and had significantly smaller sites of synaptic contact. Significantly, there was no change in the volume of classical dendritic spines at neighboring inputs to CA3 neurons suggesting input-specific defects in the early course of AD related pathology. These data indicate a specific vulnerability of the DG-CA3 network in AD pathogenesis and demonstrate the utility of SBEM to assess circuit specific alterations in mouse models of human disease. PMID:24454724

GFP-Mutant Human Tau Transgenic Mice Develop Tauopathy Following CNS Injections of Alzheimer's Brain-Derived Pathological Tau or Synthetic Mutant Human Tau Fibrils.

PubMed

Gibbons, Garrett S; Banks, Rachel A; Kim, Bumjin; Xu, Hong; Changolkar, Lakshmi; Leight, Susan N; Riddle, Dawn M; Li, Chi; Gathagan, Ronald J; Brown, Hannah J; Zhang, Bin; Trojanowski, John Q; Lee, Virginia M-Y

2017-11-22

Neurodegenerative proteinopathies characterized by intracellular aggregates of tau proteins, termed tauopathies, include Alzheimer's disease (AD), frontotemporal lobar degeneration (FTLD) with tau pathology (FTLD-tau), and related disorders. Pathological tau proteins derived from human AD brains (AD-tau) act as proteopathic seeds that initiate the templated aggregation of soluble tau upon intracerebral injection into tau transgenic (Tg) and wild-type mice, thereby modeling human tau pathology. In this study, we found that aged Tg mice of both sexes expressing human tau proteins harboring a pathogenic P301L MAPT mutation labeled with green fluorescent protein (T40PL-GFP Tg mouse line) exhibited hyperphosphorylated tau mislocalized to the somatodentritic domain of neurons, but these mice did not develop de novo insoluble tau aggregates, which are characteristic of human AD and related tauopathies. However, intracerebral injections of either T40PL preformed fibrils (PFFs) or AD-tau seeds into T40PL-GFP mice induced abundant intraneuronal pathological inclusions of hyperphosphorylated T40PL-GFP. These injections of pathological tau resulted in the propagation of tau pathology from the injection site to neuroanatomically connected brain regions, and these tau inclusions consisted of both T40PL-GFP and WT endogenous mouse tau. Primary neurons cultured from the brains of neonatal T40PL-GFP mice provided an informative in vitro model for examining the uptake and localization of tau PFFs. These findings demonstrate the seeded aggregation of T40PL-GFP in vivo by synthetic PFFs and human AD-tau and the utility of this system to study the neuropathological spread of tau aggregates. SIGNIFICANCE STATEMENT The stereotypical spread of pathological tau protein aggregates have recently been attributed to the transmission of proteopathic seeds. Despite the extensive use of transgenic mouse models to investigate the propagation of tau pathology in vivo , details of the aggregation process such as the early seeding events leading to new tau pathology have remained elusive. This study validates the use of GFP-labeled tau expressed by neurons in vivo and in vitro as models for investigating mechanisms underlying the seeded transmission of tau pathology as well as tau-focused drug discovery to identify disease-modifying therapies for AD and related tauopathies. Copyright © 2017 the authors 0270-6474/17/3711485-10$15.00/0.

GFP-Mutant Human Tau Transgenic Mice Develop Tauopathy Following CNS Injections of Alzheimer's Brain-Derived Pathological Tau or Synthetic Mutant Human Tau Fibrils

PubMed Central

Banks, Rachel A.; Kim, Bumjin; Xu, Hong; Changolkar, Lakshmi; Leight, Susan N.; Riddle, Dawn M.; Li, Chi; Brown, Hannah J.; Zhang, Bin

2017-01-01

Neurodegenerative proteinopathies characterized by intracellular aggregates of tau proteins, termed tauopathies, include Alzheimer's disease (AD), frontotemporal lobar degeneration (FTLD) with tau pathology (FTLD-tau), and related disorders. Pathological tau proteins derived from human AD brains (AD-tau) act as proteopathic seeds that initiate the templated aggregation of soluble tau upon intracerebral injection into tau transgenic (Tg) and wild-type mice, thereby modeling human tau pathology. In this study, we found that aged Tg mice of both sexes expressing human tau proteins harboring a pathogenic P301L MAPT mutation labeled with green fluorescent protein (T40PL-GFP Tg mouse line) exhibited hyperphosphorylated tau mislocalized to the somatodentritic domain of neurons, but these mice did not develop de novo insoluble tau aggregates, which are characteristic of human AD and related tauopathies. However, intracerebral injections of either T40PL preformed fibrils (PFFs) or AD-tau seeds into T40PL-GFP mice induced abundant intraneuronal pathological inclusions of hyperphosphorylated T40PL-GFP. These injections of pathological tau resulted in the propagation of tau pathology from the injection site to neuroanatomically connected brain regions, and these tau inclusions consisted of both T40PL-GFP and WT endogenous mouse tau. Primary neurons cultured from the brains of neonatal T40PL-GFP mice provided an informative in vitro model for examining the uptake and localization of tau PFFs. These findings demonstrate the seeded aggregation of T40PL-GFP in vivo by synthetic PFFs and human AD-tau and the utility of this system to study the neuropathological spread of tau aggregates. SIGNIFICANCE STATEMENT The stereotypical spread of pathological tau protein aggregates have recently been attributed to the transmission of proteopathic seeds. Despite the extensive use of transgenic mouse models to investigate the propagation of tau pathology in vivo, details of the aggregation process such as the early seeding events leading to new tau pathology have remained elusive. This study validates the use of GFP-labeled tau expressed by neurons in vivo and in vitro as models for investigating mechanisms underlying the seeded transmission of tau pathology as well as tau-focused drug discovery to identify disease-modifying therapies for AD and related tauopathies. PMID:28986461

A mouse radiation-induced liver disease model for stereotactic body radiation therapy validated in patients with hepatocellular carcinoma

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

Wu, Zhi-Feng, E-mail: wuzhifeng2@126.com, E-mail:

Purpose: Lower radiation tolerance of the whole liver hinders dose escalations of stereotactic body radiation therapy (SBRT) in hepatocellular carcinoma (HCC) treatment. This study was conducted to define the exact doses that result in radiation-induced liver disease (RILD) as well as to determine dose constraints for the critical organs at risk (OARs) in mice; these parameters are still undefined in HCC SBRT. Methods: This study consisted of two phases. In the primary phase, mice treated with helical tomotherapy-based SBRT were stratified according to escalating radiation doses to the livers. The pathological differences, signs [such as mouse performance status (MPS)], andmore » serum aspartate aminotransferase (AST)/alanine aminotransferase (ALT)/albumin levels were observed. Radiation-induced disease severities of the OARs were scored using systematic evaluation standards. In the validation phase in humans, 13 patients with HCC who had undergone radiotherapy before hepatectomy were enrolled to validate RILD pathological changes in a mouse study. Results: The evaluation criteria of the mouse liver radiotherapy-related signs were as follows: MPS ≥ 2.0 ± 0.52, AST/ALT ≥ 589.2 ± 118.5/137.4 ± 15.3 U/L, serum albumin ≤ 16.8 ± 2.29 g/L. The preliminary dose constraints of the OARs were also obtained, such as those for the liver (average dose ≤ 26.36 ± 1.71 Gy) and gastrointestinal tract (maximum dose ≤ 22.63 Gy). Mouse RILD models were able to be developed when the livers were irradiated with average doses of ≥31.76 ± 1.94 Gy (single fraction). RILD pathological changes in mice have also been validated in HCC patients. Conclusions: Mouse RILD models could be developed with SBRT based on the dose constraints for the OARs and evaluation criteria of mouse liver radiotherapy-related signs, and the authors’ results favor the study of further approaches to treat HCC with SBRT.« less

Mapping pathological phenotypes in a mouse model of CDKL5 disorder.

PubMed

Amendola, Elena; Zhan, Yang; Mattucci, Camilla; Castroflorio, Enrico; Calcagno, Eleonora; Fuchs, Claudia; Lonetti, Giuseppina; Silingardi, Davide; Vyssotski, Alexei L; Farley, Dominika; Ciani, Elisabetta; Pizzorusso, Tommaso; Giustetto, Maurizio; Gross, Cornelius T

2014-01-01

Mutations in cyclin-dependent kinase-like 5 (CDKL5) cause early-onset epileptic encephalopathy, a neurodevelopmental disorder with similarities to Rett Syndrome. Here we describe the physiological, molecular, and behavioral phenotyping of a Cdkl5 conditional knockout mouse model of CDKL5 disorder. Behavioral analysis of constitutive Cdkl5 knockout mice revealed key features of the human disorder, including limb clasping, hypoactivity, and abnormal eye tracking. Anatomical, physiological, and molecular analysis of the knockout uncovered potential pathological substrates of the disorder, including reduced dendritic arborization of cortical neurons, abnormal electroencephalograph (EEG) responses to convulsant treatment, decreased visual evoked responses (VEPs), and alterations in the Akt/rpS6 signaling pathway. Selective knockout of Cdkl5 in excitatory and inhibitory forebrain neurons allowed us to map the behavioral features of the disorder to separable cell-types. These findings identify physiological and molecular deficits in specific forebrain neuron populations as possible pathological substrates in CDKL5 disorder.

Genetically engineered mouse models of craniopharyngioma: an opportunity for therapy development and understanding of tumor biology.

PubMed

Apps, John Richard; Martinez-Barbera, Juan Pedro

2017-05-01

Adamantinomatous craniopharyngioma (ACP) is the commonest tumor of the sellar region in childhood. Two genetically engineered mouse models have been developed and are giving valuable insights into ACP biology. These models have identified novel pathways activated in tumors, revealed an important function of paracrine signalling and extended conventional theories about the role of organ-specific stem cells in tumorigenesis. In this review, we summarize these mouse models, what has been learnt, their limitations and open questions for future research. We then discussed how these mouse models may be used to test novel therapeutics against potentially targetable pathways recently identified in human ACP. © 2017 The Authors. Brain Pathology published by John Wiley & Sons Ltd on behalf of International Society of Neuropathology.

A CTRP5 gene S163R mutation knock-in mouse model for late-onset retinal degeneration.

PubMed

Chavali, Venkata R M; Khan, Naheed W; Cukras, Catherine A; Bartsch, Dirk-Uwe; Jablonski, Monica M; Ayyagari, Radha

2011-05-15

Late-onset retinal macular degeneration (L-ORD) is an autosomal dominant inherited disorder caused by a single missense mutation (S163R) in the CTRP5/C1QTNF5 protein. Early phenotypic features of L-ORD include: dark adaptation abnormalities, nyctalopia, and drusen deposits in the peripheral macular region. Apart from posterior segment abnormalities, these patients also develop abnormally long anterior lens zonules. In the sixth decade of life the rod and cone function declines, accompanied by electroretinogram (ERG) abnormalities. Some patients also develop choroidal neovascularization and glaucoma. In order to understand the disease pathology and mechanisms involved in retinal dystrophy, we generated a knock-in (Ctrp5(+/-)) mouse model carrying the disease-associated mutation in the mouse Ctrp5/C1QTNF5 gene. These mice develop slower rod-b wave recovery consistent with early dark adaptation abnormalities, accumulation of hyperautofluorescence spots, retinal pigment epithelium abnormalities, drusen, Bruch's membrane abnormalities, loss of photoreceptors, and retinal vascular leakage. The Ctrp5(+/-) mice, which have most of the pathological features of age-related macular degeneration, are unique and may serve as a valuable model both to understand the molecular pathology of late-onset retinal degeneration and to evaluate therapies.

A CTRP5 gene S163R mutation knock-in mouse model for late-onset retinal degeneration

PubMed Central

Chavali, Venkata R.M.; Khan, Naheed W.; Cukras, Catherine A.; Bartsch, Dirk-Uwe; Jablonski, Monica M.; Ayyagari, Radha

2011-01-01

Late-onset retinal macular degeneration (L-ORD) is an autosomal dominant inherited disorder caused by a single missense mutation (S163R) in the CTRP5/C1QTNF5 protein. Early phenotypic features of L-ORD include: dark adaptation abnormalities, nyctalopia, and drusen deposits in the peripheral macular region. Apart from posterior segment abnormalities, these patients also develop abnormally long anterior lens zonules. In the sixth decade of life the rod and cone function declines, accompanied by electroretinogram (ERG) abnormalities. Some patients also develop choroidal neovascularization and glaucoma. In order to understand the disease pathology and mechanisms involved in retinal dystrophy, we generated a knock-in (Ctrp5+/−) mouse model carrying the disease-associated mutation in the mouse Ctrp5/C1QTNF5 gene. These mice develop slower rod-b wave recovery consistent with early dark adaptation abnormalities, accumulation of hyperautofluorescence spots, retinal pigment epithelium abnormalities, drusen, Bruch's membrane abnormalities, loss of photoreceptors, and retinal vascular leakage. The Ctrp5+/−mice, which have most of the pathological features of age-related macular degeneration, are unique and may serve as a valuable model both to understand the molecular pathology of late-onset retinal degeneration and to evaluate therapies. PMID:21349921

Laminin-111 protein therapy reduces muscle pathology and improves viability of a mouse model of merosin-deficient congenital muscular dystrophy.

PubMed

Rooney, Jachinta E; Knapp, Jolie R; Hodges, Bradley L; Wuebbles, Ryan D; Burkin, Dean J

2012-04-01

Merosin-deficient congenital muscular dystrophy type 1A (MDC1A) is a lethal muscle-wasting disease that is caused by mutations in the LAMA2 gene, resulting in the loss of laminin-α2 protein. MDC1A patients exhibit severe muscle weakness from birth, are confined to a wheelchair, require ventilator assistance, and have reduced life expectancy. There are currently no effective treatments or cures for MDC1A. Laminin-α2 is required for the formation of heterotrimeric laminin-211 (ie, α2, β1, and γ1) and laminin-221 (ie, α2, β2, and γ1), which are major constituents of skeletal muscle basal lamina. Laminin-111 (ie, α1, β1, and γ1) is the predominant laminin isoform in embryonic skeletal muscle and supports normal skeletal muscle development in laminin-α2-deficient muscle but is absent from adult skeletal muscle. In this study, we determined whether treatment with Engelbreth-Holm-Swarm-derived mouse laminin-111 protein could rescue MDC1A in the dy(W-/-) mouse model. We demonstrate that laminin-111 protein systemically delivered to the muscles of laminin-α2-deficient mice prevents muscle pathology, improves muscle strength, and dramatically increases life expectancy. Laminin-111 also prevented apoptosis in laminin-α2-deficient mouse muscle and primary human MDC1A myogenic cells, which indicates a conserved mechanism of action and cross-reactivity between species. Our results demonstrate that laminin-111 can serve as an effective protein substitution therapy for the treatment of muscular dystrophy in the dy(W-/-) mouse model and establish the potential for its use in the treatment of MDC1A. Copyright © 2012 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.

Limited Activity of Clofazimine as a Single Drug in a Mouse Model of Tuberculosis Exhibiting Caseous Necrotic Granulomas

PubMed Central

Irwin, Scott M.; Gruppo, Veronica; Brooks, Elizabeth; Gilliland, Janet; Scherman, Michael; Reichlen, Matthew J.; Leistikow, Rachel; Kramnik, Igor; Nuermberger, Eric L.; Voskuil, Martin I.

2014-01-01

New drugs and drugs with a novel mechanism of action are desperately needed to shorten the duration of tuberculosis treatment, to prevent the emergence of drug resistance, and to treat multiple-drug-resistant strains of Mycobacterium tuberculosis. Recently, there has been renewed interest in clofazimine (CFZ). In this study, we utilized the C3HeB/FeJ mouse model, possessing highly organized, hypoxic pulmonary granulomas with caseous necrosis, to evaluate CFZ monotherapy in comparison to results with BALB/c mice, which form only multifocal, coalescing cellular aggregates devoid of caseous necrosis. While CFZ treatment was highly effective in BALB/c mice, its activity was attenuated in the lungs of C3HeB/FeJ mice. This lack of efficacy was directly related to the pathological progression of disease in these mice, since administration of CFZ prior to the formation of hypoxic, necrotic granulomas reconstituted bactericidal activity in this mouse strain. These results support the continued use of mouse models of tuberculosis infection which exhibit a granulomatous response in the lungs that more closely resembles the pathology found in human disease. PMID:24798275

Galectin-1 Protein Therapy Prevents Pathology and Improves Muscle Function in the mdx Mouse Model of Duchenne Muscular Dystrophy.

PubMed

Van Ry, Pam M; Wuebbles, Ryan D; Key, Megan; Burkin, Dean J

2015-08-01

Duchenne muscular dystrophy (DMD) is a fatal neuromuscular disease caused by mutations in the dystrophin gene, leading to the loss of a critical component of the sarcolemmal dystrophin glycoprotein complex. Galectin-1 is a small 14 kDa protein normally found in skeletal muscle and has been shown to be a modifier of immune response, muscle repair, and apoptosis. Galectin-1 levels are elevated in the muscle of mouse and dog models of DMD. Together, these findings led us to hypothesize that Galectin-1 may serve as a modifier of disease progression in DMD. To test this hypothesis, recombinant mouse Galectin-1 was produced and used to treat myogenic cells and the mdx mouse model of DMD. Here we show that intramuscular and intraperitoneal injections of Galectin-1 into mdx mice prevented pathology and improved muscle function in skeletal muscle. These improvements were a result of enhanced sarcolemmal stability mediated by elevated utrophin and α7β1 integrin protein levels. Together our results demonstrate for the first time that Galectin-1 may serve as an exciting new protein therapeutic for the treatment of DMD.

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

PubMed Central

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

2015-01-01

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

Genetically engineered mouse models for studying inflammatory bowel disease.

PubMed

Mizoguchi, Atsushi; Takeuchi, Takahito; Himuro, Hidetomo; Okada, Toshiyuki; Mizoguchi, Emiko

2016-01-01

Inflammatory bowel disease (IBD) is a chronic intestinal inflammatory condition that is mediated by very complex mechanisms controlled by genetic, immune, and environmental factors. More than 74 kinds of genetically engineered mouse strains have been established since 1993 for studying IBD. Although mouse models cannot fully reflect human IBD, they have provided significant contributions for not only understanding the mechanism, but also developing new therapeutic means for IBD. Indeed, 20 kinds of genetically engineered mouse models carry the susceptibility genes identified in human IBD, and the functions of some other IBD susceptibility genes have also been dissected out using mouse models. Cutting-edge technologies such as cell-specific and inducible knockout systems, which were recently employed to mouse IBD models, have further enhanced the ability of investigators to provide important and unexpected rationales for developing new therapeutic strategies for IBD. In this review article, we briefly introduce 74 kinds of genetically engineered mouse models that spontaneously develop intestinal inflammation. Copyright © 2015 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

A mouse model for fucosidosis recapitulates storage pathology and neurological features of the milder form of the human disease

PubMed Central

Wolf, Heike; Stroobants, Stijn; D'Hooge, Rudi; Hermans-Borgmeyer, Irm; Lüllmann-Rauch, Renate; Dierks, Thomas; Lübke, Torben

2016-01-01

ABSTRACT Fucosidosis is a rare lysosomal storage disorder caused by the inherited deficiency of the lysosomal hydrolase α-L-fucosidase, which leads to an impaired degradation of fucosylated glycoconjugates. Here, we report the generation of a fucosidosis mouse model, in which the gene for lysosomal α-L-fucosidase (Fuca1) was disrupted by gene targeting. Homozygous knockout mice completely lack α-L-fucosidase activity in all tested organs leading to highly elevated amounts of the core-fucosylated glycoasparagine Fuc(α1,6)-GlcNAc(β1-N)-Asn and, to a lesser extent, other fucosylated glycoasparagines, which all were also partially excreted in urine. Lysosomal storage pathology was observed in many visceral organs, such as in the liver, kidney, spleen and bladder, as well as in the central nervous system (CNS). On the cellular level, storage was characterized by membrane-limited cytoplasmic vacuoles primarily containing water-soluble storage material. In the CNS, cellular alterations included enlargement of the lysosomal compartment in various cell types, accumulation of secondary storage material and neuroinflammation, as well as a progressive loss of Purkinje cells combined with astrogliosis leading to psychomotor and memory deficits. Our results demonstrate that this new fucosidosis mouse model resembles the human disease and thus will help to unravel underlying pathological processes. Moreover, this model could be utilized to establish diagnostic and therapeutic strategies for fucosidosis. PMID:27491075

Pathogenic role and therapeutic potential of pleiotrophin in mouse models of ocular vascular disease.

PubMed

Wang, Weiwen; LeBlanc, Michelle E; Chen, Xiuping; Chen, Ping; Ji, Yanli; Brewer, Megan; Tian, Hong; Spring, Samantha R; Webster, Keith A; Li, Wei

2017-11-01

Angiogenic factors play an important role in the pathogenesis of diabetic retinopathy (DR), neovascular age-related macular degeneration (nAMD) and retinopathy of prematurity (ROP). Pleiotrophin, a well-known angiogenic factor, was recently reported to be upregulated in the vitreous fluid of patients with proliferative DR (PDR). However, its pathogenic role and therapeutic potential in ocular vascular diseases have not been defined in vivo. Here using corneal pocket assays, we demonstrated that pleiotrophin induced angiogenesis in vivo. To investigate the pathological role of pleiotrophin we used neutralizing antibody to block its function in multiple in vivo models of ocular vascular diseases. In a mouse model of DR, intravitreal injection of pleiotrophin-neutralizing antibody alleviated diabetic retinal vascular leakage. In a mouse model of oxygen-induced retinopathy (OIR), which is a surrogate model of ROP and PDR, we demonstrated that intravitreal injection of anti-pleiotrophin antibody prevented OIR-induced pathological retinal neovascularization and aberrant vessel tufts. Finally, pleiotrophin-neutralizing antibody ameliorated laser-induced choroidal neovascularization, a mouse model of nAMD, suggesting that pleiotrophin is involved in choroidal vascular disease. These findings suggest that pleiotrophin plays an important role in the pathogenesis of DR with retinal vascular leakage, ROP with retinal neovascularization and nAMD with choroidal neovascularization. The results also support pleiotrophin as a promising target for anti-angiogenic therapy.

Mouse homologues of human hereditary disease.

PubMed Central

Searle, A G; Edwards, J H; Hall, J G

1994-01-01

Details are given of 214 loci known to be associated with human hereditary disease, which have been mapped on both human and mouse chromosomes. Forty two of these have pathological variants in both species; in general the mouse variants are similar in their effects to the corresponding human ones, but exceptions include the Dmd/DMD and Hprt/HPRT mutations which cause little, if any, harm in mice. Possible reasons for phenotypic differences are discussed. In most pathological variants the gene product seems to be absent or greatly reduced in both species. The extensive data on conserved segments between human and mouse chromosomes are used to predict locations in the mouse of over 50 loci of medical interest which are mapped so far only on human chromosomes. In about 80% of these a fairly confident prediction can be made. Some likely homologies between mapped mouse loci and unmapped human ones are also given. Sixty six human and mouse proto-oncogene and growth factor gene homologies are also listed; those of confirmed location are all in known conserved segments. A survey of 18 mapped human disease loci and chromosome regions in which the manifestation or severity of pathological effects is thought to be the result of genomic imprinting shows that most of the homologous regions in the mouse are also associated with imprinting, especially those with homologues on human chromosomes 11p and 15q. Useful methods of accelerating the production of mouse models of human hereditary disease include (1) use of a supermutagen, such as ethylnitrosourea (ENU), (2) targeted mutagenesis involving ES cells, and (3) use of gene transfer techniques, with production of 'knockout mutations'. PMID:8151633

Accumulation of phosphorylated alpha-synuclein (p129S) and retinal pathology in a mouse model of Parkinson's disease

USDA-ARS?s Scientific Manuscript database

Aims: Parkinson's disease (PD) is a neurodegenerative disorder characterized by accumulation of misfolded alpha-synuclein within the CNS. Although non-motor clinical phenotypes of PD such as visual dysfunction have become increasingly apparent, retinal pathology associated with PD is not well under...

Analysis of spatial heterogeneity in normal epithelium and preneoplastic alterations in mouse prostate tumor models

PubMed Central

Valkonen, Mira; Ruusuvuori, Pekka; Kartasalo, Kimmo; Nykter, Matti; Visakorpi, Tapio; Latonen, Leena

2017-01-01

Cancer involves histological changes in tissue, which is of primary importance in pathological diagnosis and research. Automated histological analysis requires ability to computationally separate pathological alterations from normal tissue with all its variables. On the other hand, understanding connections between genetic alterations and histological attributes requires development of enhanced analysis methods suitable also for small sample sizes. Here, we set out to develop computational methods for early detection and distinction of prostate cancer-related pathological alterations. We use analysis of features from HE stained histological images of normal mouse prostate epithelium, distinguishing the descriptors for variability between ventral, lateral, and dorsal lobes. In addition, we use two common prostate cancer models, Hi-Myc and Pten+/− mice, to build a feature-based machine learning model separating the early pathological lesions provoked by these genetic alterations. This work offers a set of computational methods for separation of early neoplastic lesions in the prostates of model mice, and provides proof-of-principle for linking specific tumor genotypes to quantitative histological characteristics. The results obtained show that separation between different spatial locations within the organ, as well as classification between histologies linked to different genetic backgrounds, can be performed with very high specificity and sensitivity. PMID:28317907

Differential Neurotoxicity Related to Tetracycline Transactivator and TDP-43 Expression in Conditional TDP-43 Mouse Model of Frontotemporal Lobar Degeneration.

PubMed

Kukreja, L; Shahidehpour, R; Kim, G; Keegan, J; Sadleir, K R; Russell, T; Csernansky, J; Mesulam, M; Vassar, R J; Wang, L; Dong, H; Geula, C

2018-05-28

Frontotemporal lobar degeneration (FTLD) is among the most prevalent dementias of early-onset. Pathologically, FTLD presents with tauopathy or TAR DNA-binding protein 43 (TDP-43) proteinopathy. A biallelic mouse model of FTLD was produced on a mix FVB/129SVE background overexpressing wild-type human TDP-43 (hTDP-43) employing tetracycline transactivator (tTA), a system widely used in mouse models of neurological disorders. tTA activates hTDP-43 which is placed downstream of the tetracycline response element (TRE). The original study on this transgenic mouse found hippocampal degeneration following hTDP-43 expression, but did not account for independent effects of tTA protein. Here, we initially analyzed the neurotoxic effects of tTA in post-weaning age mice of either sex using immunostaining and area measurements of select brain regions. We observed tTA-dependent toxicity selectively in the hippocampus affecting the dentate gyrus significantly more than CA fields, whereas hTDP-43-dependent toxicity in bigenic mice occurred in most other cortical regions. Atrophy was associated with inflammation, activation of caspase-3 and loss of neurons. The atrophy associated with tTA expression was rescuable by tetracycline analog, doxycycline in the diet. MRI studies corroborated the patterns of atrophy. tTA-induced degeneration was strain-dependent and was rescued by moving the transgene onto a congenic C57BL/6 background. Despite significant hippocampal atrophy, behavioral tests in bigenic mice revealed no hippocampally mediated memory impairment. Significant atrophy in most cortical areas due solely to TDP-43 expression indicates that this mouse model remains useful for providing critical insight into co-occurrence of TDP-43 pathology, neurodegeneration and behavioral deficits in FTLD. SIGNIFICANCE STATEMENT The tTA expression system has been widely used in mice to model neurological disorders. The technique allows investigators to reversibly turn on or off disease causing genes. Here, we report on a mouse model that overexpresses human TDP-43 using tTA and attempt to recapitulate features of TDP-43 pathology present in human FTLD. The tTA expression system is problematic, resulting in dramatic degeneration of the hippocampus. Thus, our study adds a note of caution for the use of the tTA system. However, since FTLD is primarily characterized by cortical degeneration and our mouse model shows significant atrophy in most cortical areas due to human TDP-43 overexpression, our animal model remains useful for providing critical insight on this human disease. Copyright © 2018 the authors.

GAA repeat expansion mutation mouse models of Friedreich ataxia exhibit oxidative stress leading to progressive neuronal and cardiac pathology.

PubMed

Al-Mahdawi, Sahar; Pinto, Ricardo Mouro; Varshney, Dhaval; Lawrence, Lorraine; Lowrie, Margaret B; Hughes, Sian; Webster, Zoe; Blake, Julian; Cooper, J Mark; King, Rosalind; Pook, Mark A

2006-11-01

Friedreich ataxia (FRDA) is a neurodegenerative disorder caused by an unstable GAA repeat expansion mutation within intron 1 of the FXN gene. However, the origins of the GAA repeat expansion, its unstable dynamics within different cells and tissues, and its effects on frataxin expression are not yet completely understood. Therefore, we have chosen to generate representative FRDA mouse models by using the human FXN GAA repeat expansion itself as the genetically modified mutation. We have previously reported the establishment of two lines of human FXN YAC transgenic mice that contain unstable GAA repeat expansions within the appropriate genomic context. We now describe the generation of FRDA mouse models by crossbreeding of both lines of human FXN YAC transgenic mice with heterozygous Fxn knockout mice. The resultant FRDA mice that express only human-derived frataxin show comparatively reduced levels of frataxin mRNA and protein expression, decreased aconitase activity, and oxidative stress, leading to progressive neurodegenerative and cardiac pathological phenotypes. Coordination deficits are present, as measured by accelerating rotarod analysis, together with a progressive decrease in locomotor activity and increase in weight. Large vacuoles are detected within neurons of the dorsal root ganglia (DRG), predominantly within the lumbar regions in 6-month-old mice, but spreading to the cervical regions after 1 year of age. Secondary demyelination of large axons is also detected within the lumbar roots of older mice. Lipofuscin deposition is increased in both DRG neurons and cardiomyocytes, and iron deposition is detected in cardiomyocytes after 1 year of age. These mice represent the first GAA repeat expansion-based FRDA mouse models that exhibit progressive FRDA-like pathology and thus will be of use in testing potential therapeutic strategies, particularly GAA repeat-based strategies.

Reduced bioavailable manganese causes striatal urea cycle pathology in Huntington's disease mouse model.

PubMed

Bichell, Terry Jo V; Wegrzynowicz, Michal; Tipps, K Grace; Bradley, Emma M; Uhouse, Michael A; Bryan, Miles; Horning, Kyle; Fisher, Nicole; Dudek, Karrie; Halbesma, Timothy; Umashanker, Preethi; Stubbs, Andrew D; Holt, Hunter K; Kwakye, Gunnar F; Tidball, Andrew M; Colbran, Roger J; Aschner, Michael; Neely, M Diana; Di Pardo, Alba; Maglione, Vittorio; Osmand, Alexander; Bowman, Aaron B

2017-06-01

Huntington's disease (HD) is caused by a mutation in the huntingtin gene (HTT), resulting in profound striatal neurodegeneration through an unknown mechanism. Perturbations in the urea cycle have been reported in HD models and in HD patient blood and brain. In neurons, arginase is a central urea cycle enzyme, and the metal manganese (Mn) is an essential cofactor. Deficient biological responses to Mn, and reduced Mn accumulation have been observed in HD striatal mouse and cell models. Here we report in vivo and ex vivo evidence of a urea cycle metabolic phenotype in a prodromal HD mouse model. Further, either in vivo or in vitro Mn supplementation reverses the urea-cycle pathology by restoring arginase activity. We show that Arginase 2 (ARG2) is the arginase enzyme present in these mouse brain models, with ARG2 protein levels directly increased by Mn exposure. ARG2 protein is not reduced in the prodromal stage, though enzyme activity is reduced, indicating that altered Mn bioavailability as a cofactor leads to the deficient enzymatic activity. These data support a hypothesis that mutant HTT leads to a selective deficiency of neuronal Mn at an early disease stage, contributing to HD striatal urea-cycle pathophysiology through an effect on arginase activity. Copyright © 2017 The Author(s). Published by Elsevier B.V. All rights reserved.

Early white matter abnormalities, progressive brain pathology and motor deficits in a novel knock-in mouse model of Huntington's disease

PubMed Central

Jin, Jing; Peng, Qi; Hou, Zhipeng; Jiang, Mali; Wang, Xin; Langseth, Abraham J.; Tao, Michael; Barker, Peter B.; Mori, Susumu; Bergles, Dwight E.; Ross, Christopher A.; Detloff, Peter J.; Zhang, Jiangyang; Duan, Wenzhen

2015-01-01

White matter abnormalities have been reported in premanifest Huntington's disease (HD) subjects before overt striatal neuronal loss, but whether the white matter changes represent a necessary step towards further pathology and the underlying mechanism of these changes remains unknown. Here, we characterized a novel knock-in mouse model that expresses mouse HD gene homolog (Hdh) with extended CAG repeat- HdhQ250, which was derived from the selective breeding of HdhQ150 mice. HdhQ250 mice manifest an accelerated and robust phenotype compared with its parent line. HdhQ250 mice exhibit progressive motor deficits, reduction in striatal and cortical volume, accumulation of mutant huntingtin aggregation, decreased levels of DARPP32 and BDNF and altered striatal metabolites. The abnormalities detected in this mouse model are reminiscent of several aspects of human HD. In addition, disturbed myelination was evident in postnatal Day 14 HdhQ250 mouse brain, including reduced levels of myelin regulatory factor and myelin basic protein, and decreased numbers of myelinated axons in the corpus callosum. Thinner myelin sheaths, indicated by increased G-ratio of myelin, were also detected in the corpus callosum of adult HdhQ250 mice. Moreover, proliferation of oligodendrocyte precursor cells is altered by mutant huntingtin both in vitro and in vivo. Our data indicate that this model is suitable for understanding comprehensive pathogenesis of HD in white matter and gray matter as well as developing therapeutics for HD. PMID:25609071

Novel Genetic Models to Study the Role of Inflammation in Brain Injury-Induced Alzheimer’s Pathology

DTIC Science & Technology

2015-12-01

Clinic. (2013) “Opposing Acute and Chronic Effects of Traumatic Brain Injury in a Mouse Model of Alzheimer’s Disease” Kokiko-Cochran, O.N.  Annual...nanosymposium, Washington, D.C. (2014) “ Traumatic brain injury induces a distinct macrophage response at acute and chronic time points in a mouse model...SUPPLEMENTARY NOTES 14. ABSTRACT Individuals exposed to traumatic brain injury (TBI) are at a greatly increased risk for developing a number of

In vivo quantitative bioluminescence tomography using heterogeneous and homogeneous mouse models.

PubMed

Liu, Junting; Wang, Yabin; Qu, Xiaochao; Li, Xiangsi; Ma, Xiaopeng; Han, Runqiang; Hu, Zhenhua; Chen, Xueli; Sun, Dongdong; Zhang, Rongqing; Chen, Duofang; Chen, Dan; Chen, Xiaoyuan; Liang, Jimin; Cao, Feng; Tian, Jie

2010-06-07

Bioluminescence tomography (BLT) is a new optical molecular imaging modality, which can monitor both physiological and pathological processes by using bioluminescent light-emitting probes in small living animal. Especially, this technology possesses great potential in drug development, early detection, and therapy monitoring in preclinical settings. In the present study, we developed a dual modality BLT prototype system with Micro-computed tomography (MicroCT) registration approach, and improved the quantitative reconstruction algorithm based on adaptive hp finite element method (hp-FEM). Detailed comparisons of source reconstruction between the heterogeneous and homogeneous mouse models were performed. The models include mice with implanted luminescence source and tumor-bearing mice with firefly luciferase report gene. Our data suggest that the reconstruction based on heterogeneous mouse model is more accurate in localization and quantification than the homogeneous mouse model with appropriate optical parameters and that BLT allows super-early tumor detection in vivo based on tomographic reconstruction of heterogeneous mouse model signal.

Comparison of phosphodiesterase 10A, dopamine receptors D1 and D2 and dopamine transporter ligand binding in the striatum of the R6/2 and BACHD mouse models of Huntington's disease.

PubMed

Miller, Silke; Hill Della Puppa, Geraldine; Reidling, Jack; Marcora, Edoardo; Thompson, Leslie M; Treanor, James

2014-01-01

Phosphodiesterase 10A (PDE10A) is expressed at high levels in the striatum and has been proposed both as a biomarker for Huntington's disease pathology and as a target for intervention. PDE10A radiotracers have been successfully used to measure changes in binding density in Huntington's disease patients, but little is known about PDE10A binding in mouse models that are used extensively to model pathology and test therapeutic interventions. Our study investigated changes in PDE10A binding using the selective tracer 3H-7980 at specific ages of two Huntington's disease transgenic mouse models: R6/2, a short-lived model carrying exon-1 of mutant HTT and BACHD, a longer-lived model carrying full-length mutant HTT. PDE10A binding was compared to binding of known markers of striatal atrophy in Huntington's disease, e.g. dopamine transporter (DAT) and dopamine receptors D1 and D2. We found that in the R6/2 model at 6 weeks of age, mice showed high variability of binding, however binding of all ligands was significantly decreased at 8 and 12 weeks of age. In contrast, no changes were detectable in the BACHD model at 8, 10 or 12 month of age. These findings suggest that radiotracer binding of PDE10A, DAT, D1 and D2 receptor in the R6/2 model may be a good indicator of striatal pathological changes that are observed in Huntington's disease patients, and that the first 12 months in the BACHD model may be more reflective of early stages of the disease.

Concurrence of High Fat Diet and APOE Gene Induces Allele Specific Metabolic and Mental Stress Changes in a Mouse Model of Alzheimer's Disease.

PubMed

Segev, Yifat; Livne, Adva; Mints, Meshi; Rosenblum, Kobi

2016-01-01

Aging is the main risk factor for neurodegenerative diseases, including Alzheimer's disease (AD). However, evidence indicates that the pathological process begins long before actual cognitive or pathological symptoms are apparent. The long asymptomatic phase and complex integration between genetic, environmental and metabolic factors make it one of the most challenging diseases to understand and cure. In the present study, we asked whether an environmental factor such as high-fat (HF) diet would synergize with a genetic factor to affect the metabolic and cognitive state in the Apolipoprotein E (ApoE4) mouse model of AD. Our data suggest that a HF diet induces diabetes mellitus (DM)-like metabolism in ApoE4 mice, as well as changes in β-site amyloid precursor protein-cleaving enzyme 1 (BACE1) protein levels between the two ApoE strains. Furthermore, HF diet induces anxiety in this AD mouse model. Our results suggest that young ApoE4 carriers are prone to psychological stress and metabolic abnormalities related to AD, which can easily be triggered via HF nutrition.

Repeatability and sensitivity of high resolution blood volume mapping in mouse kidney disease.

PubMed

Wang, Feng; Jiang, Rosie T; Tantawy, Mohammed Noor; Borza, Dorin B; Takahashi, Keiko; Gore, John C; Harris, Raymond C; Takahashi, Takamune; Quarles, C Chad

2014-04-01

To evaluate the repeatability of MRI-derived relative blood volume (RBV) measurements in mouse kidneys across subjects and days and to evaluate sensitivity of this approach to renal pathology. A 7 Tesla MRI system and an intravascular iron-oxide contrast agent were used to acquire spin-echo-based renal RBV maps in 10 healthy mice on 2 consecutive days. Renal RBV maps were also acquired in the Alport and unilateral ureteral obstruction mouse models of renal disease. The average renal RBV measured on consecutive days was 19.97 ± 1.50 and 19.86 ± 1.62, yielding a concordance correlation coefficient of 0.94, indicating that this approach is highly repeatable. In the disease models, the RBV values were regionally dissimilar and substantially lower than those found in control mice. In vivo renal iron-oxide-based RBV mapping in mice complements the physiological information obtained from conventional assays of kidney function and could shed new insights into the pathological mechanisms of kidney disease. Copyright © 2013 Wiley Periodicals, Inc.

Phospho-Tau Accumulation and Structural Alterations of the Golgi Apparatus of Cortical Pyramidal Neurons in the P301S Tauopathy Mouse Model

PubMed Central

Antón-Fernández, Alejandro; Merchán-Rubira, Jesús; Avila, Jesús; Hernández, Félix; DeFelipe, Javier; Muñoz, Alberto

2017-01-01

The Golgi apparatus (GA) is a highly dynamic organelle involved in the processing and sorting of cellular proteins. In Alzheimer’s disease (AD), it has been shown to decrease in size and become fragmented in neocortical and hippocampal neuronal subpopulations. This fragmentation and decrease in size of the GA in AD has been related to the accumulation of hyperphosphorylated tau. However, the involvement of other pathological factors associated with the course of the disease, such as the extracellular accumulation of amyloid-β (Aβ) aggregates, cannot be ruled out, since both pathologies are present in AD patients. Here we use the P301S tauopathy mouse model to examine possible alterations of the GA in neurons that overexpress human tau (P301S mutated gene) in neocortical and hippocampal neurons, using double immunofluorescence techniques and confocal microscopy. Quantitative analysis revealed that neurofibrillary tangle (NFT)-bearing neurons had important morphological alterations and reductions in the surface area and volume of the GA compared with NFT-free neurons. Since in this mouse model there are no Aβ aggregates typical of AD, the present findings support the idea that the progressive accumulation of phospho-tau is associated with structural alterations of the GA, and that these changes may occur in the absence of Aβ pathology. PMID:28922155

Phospho-Tau Accumulation and Structural Alterations of the Golgi Apparatus of Cortical Pyramidal Neurons in the P301S Tauopathy Mouse Model.

PubMed

Antón-Fernández, Alejandro; Merchán-Rubira, Jesús; Avila, Jesús; Hernández, Félix; DeFelipe, Javier; Muñoz, Alberto

2017-01-01

The Golgi apparatus (GA) is a highly dynamic organelle involved in the processing and sorting of cellular proteins. In Alzheimer's disease (AD), it has been shown to decrease in size and become fragmented in neocortical and hippocampal neuronal subpopulations. This fragmentation and decrease in size of the GA in AD has been related to the accumulation of hyperphosphorylated tau. However, the involvement of other pathological factors associated with the course of the disease, such as the extracellular accumulation of amyloid-β (Aβ) aggregates, cannot be ruled out, since both pathologies are present in AD patients. Here we use the P301S tauopathy mouse model to examine possible alterations of the GA in neurons that overexpress human tau (P301S mutated gene) in neocortical and hippocampal neurons, using double immunofluorescence techniques and confocal microscopy. Quantitative analysis revealed that neurofibrillary tangle (NFT)-bearing neurons had important morphological alterations and reductions in the surface area and volume of the GA compared with NFT-free neurons. Since in this mouse model there are no Aβ aggregates typical of AD, the present findings support the idea that the progressive accumulation of phospho-tau is associated with structural alterations of the GA, and that these changes may occur in the absence of Aβ pathology.

CNS infiltration of peripheral immune cells: D-Day for neurodegenerative disease?

PubMed

Rezai-Zadeh, Kavon; Gate, David; Town, Terrence

2009-12-01

While the central nervous system (CNS) was once thought to be excluded from surveillance by immune cells, a concept known as "immune privilege," it is now clear that immune responses do occur in the CNS-giving rise to the field of neuroimmunology. These CNS immune responses can be driven by endogenous (glial) and/or exogenous (peripheral leukocyte) sources and can serve either productive or pathological roles. Recent evidence from mouse models supports the notion that infiltration of peripheral monocytes/macrophages limits progression of Alzheimer's disease pathology and militates against West Nile virus encephalitis. In addition, infiltrating T lymphocytes may help spare neuronal loss in models of amyotrophic lateral sclerosis. On the other hand, CNS leukocyte penetration drives experimental autoimmune encephalomyelitis (a mouse model for the human demyelinating disease multiple sclerosis) and may also be pathological in both Parkinson's disease and human immunodeficiency virus encephalitis. A critical understanding of the cellular and molecular mechanisms responsible for trafficking of immune cells from the periphery into the diseased CNS will be key to target these cells for therapeutic intervention in neurodegenerative diseases, thereby allowing neuroregenerative processes to ensue.

The Virtual Mouse Brain: A Computational Neuroinformatics Platform to Study Whole Mouse Brain Dynamics.

PubMed

Melozzi, Francesca; Woodman, Marmaduke M; Jirsa, Viktor K; Bernard, Christophe

2017-01-01

Connectome-based modeling of large-scale brain network dynamics enables causal in silico interrogation of the brain's structure-function relationship, necessitating the close integration of diverse neuroinformatics fields. Here we extend the open-source simulation software The Virtual Brain (TVB) to whole mouse brain network modeling based on individual diffusion magnetic resonance imaging (dMRI)-based or tracer-based detailed mouse connectomes. We provide practical examples on how to use The Virtual Mouse Brain (TVMB) to simulate brain activity, such as seizure propagation and the switching behavior of the resting state dynamics in health and disease. TVMB enables theoretically driven experimental planning and ways to test predictions in the numerous strains of mice available to study brain function in normal and pathological conditions.

Mapping Pathological Phenotypes in a Mouse Model of CDKL5 Disorder

PubMed Central

Amendola, Elena; Zhan, Yang; Mattucci, Camilla; Castroflorio, Enrico; Calcagno, Eleonora; Fuchs, Claudia; Lonetti, Giuseppina; Silingardi, Davide; Vyssotski, Alexei L.; Farley, Dominika; Ciani, Elisabetta; Pizzorusso, Tommaso; Giustetto, Maurizio; Gross, Cornelius T.

2014-01-01

Mutations in cyclin-dependent kinase-like 5 (CDKL5) cause early-onset epileptic encephalopathy, a neurodevelopmental disorder with similarities to Rett Syndrome. Here we describe the physiological, molecular, and behavioral phenotyping of a Cdkl5 conditional knockout mouse model of CDKL5 disorder. Behavioral analysis of constitutive Cdkl5 knockout mice revealed key features of the human disorder, including limb clasping, hypoactivity, and abnormal eye tracking. Anatomical, physiological, and molecular analysis of the knockout uncovered potential pathological substrates of the disorder, including reduced dendritic arborization of cortical neurons, abnormal electroencephalograph (EEG) responses to convulsant treatment, decreased visual evoked responses (VEPs), and alterations in the Akt/rpS6 signaling pathway. Selective knockout of Cdkl5 in excitatory and inhibitory forebrain neurons allowed us to map the behavioral features of the disorder to separable cell-types. These findings identify physiological and molecular deficits in specific forebrain neuron populations as possible pathological substrates in CDKL5 disorder. PMID:24838000

Enhanced Antigen Retrieval of Amyloid β Immunohistochemistry

PubMed Central

Kai, Hideaki; Ogino, Koichi; Hatsuta, Hiroyuki; Murayama, Shigeo; Kitamoto, Tetsuyuki

2012-01-01

Senile plaques, extracellular deposits of amyloid β peptide (Aβ), are one of the pathological hallmarks of Alzheimer disease (AD). As the standard immunohistochemical detection method for Aβ deposits, anti-Aβ immunohistochemistry combined with antigen retrieval (AR) by formic acid (FA) has been generally used. Here, we present a more efficient AR for Aβ antigen. On brain sections of AD and its mouse model, a double combination of either autoclave heating in EDTA buffer or digestion with proteinase K plus FA treatment reinforced Aβ immunoreactivity. A further triple combination of digestion with proteinase K (P), autoclave heating in EDTA buffer (A), and FA treatment (F), when employed in this order, gave a more enhanced immunoreactivity. Our PAF method prominently visualized various forms of Aβ deposits in AD that have not been clearly detected previously and revealed numerous minute-sized plaques both in AD and the mouse model. Quantification of Aβ loads showed that the AR effect by the PAF method was 1.86-fold (in the aged human brain) and 4.64-fold (in the mouse brain) higher than that by the FA method. Thus, the PAF method could have the potential to be the most sensitive tool so far to study Aβ pathology in AD and its mouse model. PMID:22821668

Eye-Directed Overpressure Airwave-Induced Trauma Causes Lasting Damage to the Anterior and Posterior Globe: A Model for Testing Cell-Based Therapies

PubMed Central

Bricker-Anthony, Courtney; Hines-Beard, Jessica

2016-01-01

Abstract Purpose: Characterization of the response of the Balb/c mouse to an eye-directed overpressure airwave, with the hypothesis that this mouse strain and model is useful for testing potential therapeutics for the treatment of traumatic eye injury. Methods: The left eyes of adult Balb/c mice were exposed to an eye-directed overpressure airwave. Intraocular pressure (IOP) was measured and eyes were inspected for gross pathology changes. Optical coherence tomography and histology were used to examine the structural integrity of the retina and optic nerve. Immunohistochemistry, in vivo molecular fluorophores, and a multiplex enzyme-linked immunosorbent assay were utilized to identify changes in cell death, neuroinflammation, and oxidative stress. Results: This model induced a transient increase in IOP, corneal injuries, infrequent large retinal detachments, retinal pigment epithelium (RPE) vacuolization, glial reactivity, and retinal cell death. Both the corneal damage and RPE vacuolization persisted with time. Optic nerve degeneration occurred as early as 7 days postinjury and persisted out to 60 days. Retinal cell death, increased levels of reactive oxygen species, and neuroinflammation were detected at 7 days postinjury. Conclusions: The injury profile of the Balb/c mouse is consistent with commonly observed pathologies in blast-exposed patients. The damage is throughout the eye and persistent, making this mouse model useful for testing cell-based therapies. PMID:26982447

Assessment of bone dysplasia by micro-CT and glycosaminoglycan levels in mouse models for mucopolysaccharidosis type I, IIIA, IVA, and VII

PubMed Central

Rowan, Daniel J.; Tomatsu, Shunji; Grubb, Jeffrey H.; Montaño, Adriana M.; Sly, William S.

2012-01-01

Summary Mucopolysaccharidoses (MPS) are a group of lysosomal storage diseases caused by mutations in lysosomal enzymes involved in degradation of glycosaminoglycans (GAGs). Patients with MPS grow poorly and become physically disabled due to systemic bone disease. While many of the major skeletal effects in mouse models for MPS have been described, no detailed analysis that compares GAGs levels and characteristics of bone by micro-CT has been done. The aims of this study were to assess severity of bone dysplasia among four MPS mouse models (MPS I, IIIA, IVA and VII), to determine the relationship between severity of bone dysplasia and serum keratan sulfate (KS) and heparan sulfate (HS) levels in those models, and to explore the mechanism of KS elevation in MPS I, IIIA, and VII mouse models. Clinically, MPS VII mice had the most severe bone pathology; however, MPS I and IVA mice also showed skeletal pathology. MPS I and VII mice showed severe bone dysplasia, higher bone mineral density, narrowed spinal canal, and shorter sclerotic bones by micro-CT and radiographs. Serum KS and HS levels were elevated in MPS I, IIIA, and VII mice. Severity of skeletal disease displayed by micro-CT, radiographs and histopathology correlated with the level of KS elevation. We showed that elevated HS levels in MPS mouse models could inhibit N-acetylgalactosamine-6-sulfate sulfatase enzyme. These studies suggest that KS could be released from chondrocytes affected by accumulation of other GAGs and that KS could be useful as a biomarker for severity of bone dysplasia in MPS disorders. PMID:22971960

ACE Over Expression in Myelomonocytic Cells: Effect on a Mouse Model of Alzheimer's Disease

PubMed Central

Koronyo-Hamaoui, Maya; Shah, Kandarp; Koronyo, Yosef; Bernstein, Ellen; Giani, Jorge F.; Janjulia, Tea; Black, Keith L.; Shi, Peng D.; Gonzalez-Villalobos, Romer A.; Fuchs, Sebastien; Shen, Xiao Z.; Bernstein, Kenneth E.

2014-01-01

While it is well known that angiotensin converting enzyme (ACE) plays an important role in blood pressure control, ACE also has effects on renal function, hematopoiesis, reproduction, and aspects of the immune response. ACE 10/10 mice over express ACE in myelomonocytic cells. Macrophages from these mice have an increased polarization towards a pro-inflammatory phenotype that results in a very effective immune response to challenge by tumors or bacterial infection. In a mouse model of Alzheimer's disease (AD), the ACE 10/10 phenotype provides significant protection against AD pathology, including reduced inflammation, reduced burden of the neurotoxic amyloid-β protein and preserved cognitive function. Taken together, these studies show that increased myelomonocytic ACE expression in mice alters the immune response to better defend against many different types of pathologic insult, including the cognitive decline observed in an animal model of AD. PMID:24792094

Inducible and reversible phenotypes in a novel mouse model of Friedreich’s Ataxia

PubMed Central

Gao, Kun; Swarup, Vivek; Versano, Revital; Dong, Hongmei; Jordan, Maria C

2017-01-01

Friedreich's ataxia (FRDA), the most common inherited ataxia, is caused by recessive mutations that reduce the levels of frataxin (FXN), a mitochondrial iron binding protein. We developed an inducible mouse model of Fxn deficiency that enabled us to control the onset and progression of disease phenotypes by the modulation of Fxn levels. Systemic knockdown of Fxn in adult mice led to multiple phenotypes paralleling those observed in human patients across multiple organ systems. By reversing knockdown after clinical features appear, we were able to determine to what extent observed phenotypes represent reversible cellular dysfunction. Remarkably, upon restoration of near wild-type FXN levels, we observed significant recovery of function, associated pathology and transcriptomic dysregulation even after substantial motor dysfunction and pathology were observed. This model will be of broad utility in therapeutic development and in refining our understanding of the relative contribution of reversible cellular dysfunction at different stages in disease. PMID:29257745

Immunotherapy for choroidal neovascularization in a laser-induced mouse model simulating exudative (wet) macular degeneration

NASA Astrophysics Data System (ADS)

Bora, Puran S.; Hu, Zhiwei; Tezel, Tongalp H.; Sohn, Jeong-Hyeon; Kang, Shin Goo; Cruz, Jose M. C.; Bora, Nalini S.; Garen, Alan; Kaplan, Henry J.

2003-03-01

Age-related macular degeneration (AMD) is the leading cause of blindness after age 55 in the industrialized world. Severe loss of central vision frequently occurs with the exudative (wet) form of AMD, as a result of the formation of a pathological choroidal neovasculature (CNV) that damages the macular region of the retina. We tested the effect of an immunotherapy procedure, which had been shown to destroy the pathological neovasculature in solid tumors, on the formation of laser-induced CNV in a mouse model simulating exudative AMD in humans. The procedure involves administering an Icon molecule that binds with high affinity and specificity to tissue factor (TF), resulting in the activation of a potent cytolytic immune response against cells expressing TF. The Icon binds selectively to TF on the vascular endothelium of a CNV in the mouse and pig models and also on the CNV of patients with exudative AMD. Here we show that the Icon dramatically reduces the frequency of CNV formation in the mouse model. After laser treatment to induce CNV formation, the mice were injected either with an adenoviral vector encoding the Icon, resulting in synthesis of the Icon by vector-infected mouse cells, or with the Icon protein. The route of injection was i.v. or intraocular. The efficacy of the Icon in preventing formation of laser-induced CNV depends on binding selectively to the CNV. Because the Icon binds selectively to the CNV in exudative AMD as well as to laser-induced CNV, the Icon might also be efficacious for treating patients with exudative AMD.

Development and function of human innate immune cells in a humanized mouse model.

PubMed

Rongvaux, Anthony; Willinger, Tim; Martinek, Jan; Strowig, Till; Gearty, Sofia V; Teichmann, Lino L; Saito, Yasuyuki; Marches, Florentina; Halene, Stephanie; Palucka, A Karolina; Manz, Markus G; Flavell, Richard A

2014-04-01

Mice repopulated with human hematopoietic cells are a powerful tool for the study of human hematopoiesis and immune function in vivo. However, existing humanized mouse models cannot support development of human innate immune cells, including myeloid cells and natural killer (NK) cells. Here we describe two mouse strains called MITRG and MISTRG, in which human versions of four genes encoding cytokines important for innate immune cell development are knocked into their respective mouse loci. The human cytokines support the development and function of monocytes, macrophages and NK cells derived from human fetal liver or adult CD34(+) progenitor cells injected into the mice. Human macrophages infiltrated a human tumor xenograft in MITRG and MISTRG mice in a manner resembling that observed in tumors obtained from human patients. This humanized mouse model may be used to model the human immune system in scenarios of health and pathology, and may enable evaluation of therapeutic candidates in an in vivo setting relevant to human physiology.

Development and function of human innate immune cells in a humanized mouse model

PubMed Central

Rongvaux, Anthony; Willinger, Tim; Martinek, Jan; Strowig, Till; Gearty, Sofia V.; Teichmann, Lino L.; Saito, Yasuyuki; Marches, Florentina; Halene, Stephanie; Palucka, A. Karolina; Manz, Markus G.; Flavell, Richard A.

2014-01-01

Mice repopulated with human hematopoietic cells are a powerful tool for the study of human hematopoiesis and immune function in vivo. However, existing humanized mouse models are unable to support development of human innate immune cells, including myeloid cells and NK cells. Here we describe a mouse strain, called MI(S)TRG, in which human versions of four genes encoding cytokines important for innate immune cell development are knocked in to their respective mouse loci. The human cytokines support the development and function of monocytes/macrophages and natural killer cells derived from human fetal liver or adult CD34+ progenitor cells injected into the mice. Human macrophages infiltrated a human tumor xenograft in MI(S)TRG mice in a manner resembling that observed in tumors obtained from human patients. This humanized mouse model may be used to model the human immune system in scenarios of health and pathology, and may enable evaluation of therapeutic candidates in an in vivo setting relevant to human physiology. PMID:24633240

Harnessing the immune system for treatment and detection of tau pathology.

PubMed

Congdon, Erin E; Krishnaswamy, Senthilkumar; Sigurdsson, Einar M

2014-01-01

The tau protein is an attractive target for therapy and diagnosis. We started a tau immunotherapy program about 13 years ago and have since demonstrated that active and passive immunotherapies diminish tau pathology and improve function, including cognition, in different mouse models. These findings have been confirmed and extended by several groups. We routinely detect neuronal, and to a lesser extent microglial, antibody uptake correlating with tau pathology. Antibodies bind tau aggregates in the endosomal/lysosomal system, enhancing clearance presumably by promoting their disassembly. Extracellular clearance has recently been shown by others, using antibodies that apparently are not internalized. As most pathological tau is neuronal, intracellular targeting may be more efficacious. However, extracellular tau may be more accessible to antibodies, with tau-antibody complexes a target for microglial phagocytosis. The extent of involvement of each pathway may depend on numerous factors including antibody properties, degree of pathology, and experimental model. On the imaging front, multiple tau ligands derived from β-sheet dyes have been developed by several groups, some with promising results in clinical PET tests. Postmortem analysis should clarify their tau specificity, as in theory and based on histological staining, those are likely to have some affinity for various amyloids. We are developing antibody-derived tau probes that should be more specific, and have in mouse models shown in vivo detection and binding to pathological tau after peripheral injection. These are exciting times for research on tau therapies and diagnostic agents that hopefully can be applied to humans in the near future.

Neutral Sphingomyelinase-2 Deficiency Ameliorates Alzheimer's Disease Pathology and Improves Cognition in the 5XFAD Mouse.

PubMed

Dinkins, Michael B; Enasko, John; Hernandez, Caterina; Wang, Guanghu; Kong, Jina; Helwa, Inas; Liu, Yutao; Terry, Alvin V; Bieberich, Erhard

2016-08-17

Recent evidence implicates exosomes in the aggregation of Aβ and spreading of tau in Alzheimer's disease. In neural cells, exosome formation can be blocked by inhibition or silencing of neutral sphingomyelinase-2 (nSMase2). We generated genetically nSMase2-deficient 5XFAD mice (fro;5XFAD) to assess AD-related pathology in a mouse model with consistently reduced ceramide generation. We conducted in vitro assays to assess Aβ42 aggregation and glial clearance with and without exosomes isolated by ultracentrifugation and determined exosome-induced amyloid aggregation by particle counting. We analyzed brain exosome content, amyloid plaque formation, neuronal degeneration, sphingolipid, Aβ42 and phospho-tau levels, and memory-related behaviors in 5XFAD versus fro;5XFAD mice using contextual and cued fear conditioning. Astrocyte-derived exosomes accelerated aggregation of Aβ42 and blocked glial clearance of Aβ42 in vitro Aβ42 aggregates were colocalized with extracellular ceramide in vitro using a bifunctional ceramide analog preloaded into exosomes and in vivo using anticeramide IgG, implicating ceramide-enriched exosomes in plaque formation. Compared with 5XFAD mice, the fro;5XFAD mice had reduced brain exosomes, ceramide levels, serum anticeramide IgG, glial activation, total Aβ42 and plaque burden, tau phosphorylation, and improved cognition in a fear-conditioned learning task. Ceramide-enriched exosomes appear to exacerbate AD-related brain pathology by promoting the aggregation of Aβ. Reduction of exosome secretion by nSMase2 loss of function improves pathology and cognition in the 5XFAD mouse model. We present for the first time evidence, using Alzheimer's disease (AD) model mice deficient in neural exosome secretion due to lack of neutral sphingomyelinase-2 function, that ceramide-enriched exosomes exacerbate AD-related pathologies and cognitive deficits. Our results provide rationale to pursue a means of inhibiting exosome secretion as a potential therapy for individuals at risk for developing AD. Copyright © 2016 the authors 0270-6474/16/368653-15$15.00/0.

B4GALNT2 (GALGT2) Gene Therapy Reduces Skeletal Muscle Pathology in the FKRP P448L Mouse Model of Limb Girdle Muscular Dystrophy 2I.

PubMed

Thomas, Paul J; Xu, Rui; Martin, Paul T

2016-09-01

Overexpression of B4GALNT2 (previously GALGT2) inhibits the development of muscle pathology in mouse models of Duchenne muscular dystrophy, congenital muscular dystrophy 1A, and limb girdle muscular dystrophy 2D. In these models, muscle GALGT2 overexpression induces the glycosylation of α dystroglycan with the cytotoxic T cell glycan and increases the overexpression of dystrophin and laminin α2 surrogates known to inhibit disease. Here, we show that GALGT2 gene therapy significantly reduces muscle pathology in FKRP P448Lneo(-) mice, a model for limb girdle muscular dystrophy 2I. rAAVrh74.MCK.GALGT2-treated FKRP P448Lneo(-) muscles showed reduced levels of centrally nucleated myofibers, reduced variance, increased size of myofiber diameters, reduced myofiber immunoglobulin G uptake, and reduced muscle wasting at 3 and 6 months after treatment. GALGT2 overexpression in FKRP P448Lneo(-) muscles did not cause substantial glycosylation of α dystroglycan with the cytotoxic T cell glycan or increased expression of dystrophin and laminin α2 surrogates in mature skeletal myofibers, but it increased the number of embryonic myosin-positive regenerating myofibers. These data demonstrate that GALGT2 overexpression can reduce the extent of muscle pathology in FKRP mutant muscles, but that it may do so via a mechanism that differs from its ability to induce surrogate gene expression. Copyright © 2016 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.

Study on the effects of microencapsulated Lactobacillus delbrueckii on the mouse intestinal flora.

PubMed

Sun, Qingshen; Shi, Yue; Wang, Fuying; Han, Dequan; Lei, Hong; Zhao, Yao; Sun, Quan

2015-01-01

To evaluate the protective effects of microencapsulation on Lactobacillus delbrueckii by random, parallel experimental design. Lincomycin hydrochloride-induced intestinal malfunction mouse model was successfully established; then the L. delbrueckii microcapsule was given to the mouse. The clinical behaviour, number of intestinal flora, mucous IgA content in small intestine, IgG and IL-2 level in peripheral blood were monitored. The histological sections were also prepared. The L. delbrueckii microcapsule could have more probiotic effects as indicated by higher bifidobacterium number in cecal contents. The sIgA content in microcapsule treated group was significantly higher than that in non-encapsulated L. delbrueckii treated group (p < 0.05). Intestine pathological damage of the L. delbrueckii microcapsule-treated group showed obvious restoration. The L. delbrueckii microcapsules could relieve the intestinal tissue pathological damage and play an important role in curing antibiotic-induced intestinal flora dysfunction.

Concurrence of High Fat Diet and APOE Gene Induces Allele Specific Metabolic and Mental Stress Changes in a Mouse Model of Alzheimer’s Disease

PubMed Central

Segev, Yifat; Livne, Adva; Mints, Meshi; Rosenblum, Kobi

2016-01-01

Aging is the main risk factor for neurodegenerative diseases, including Alzheimer’s disease (AD). However, evidence indicates that the pathological process begins long before actual cognitive or pathological symptoms are apparent. The long asymptomatic phase and complex integration between genetic, environmental and metabolic factors make it one of the most challenging diseases to understand and cure. In the present study, we asked whether an environmental factor such as high-fat (HF) diet would synergize with a genetic factor to affect the metabolic and cognitive state in the Apolipoprotein E (ApoE4) mouse model of AD. Our data suggest that a HF diet induces diabetes mellitus (DM)-like metabolism in ApoE4 mice, as well as changes in β-site amyloid precursor protein-cleaving enzyme 1 (BACE1) protein levels between the two ApoE strains. Furthermore, HF diet induces anxiety in this AD mouse model. Our results suggest that young ApoE4 carriers are prone to psychological stress and metabolic abnormalities related to AD, which can easily be triggered via HF nutrition. PMID:27656136

Palatogenesis

PubMed Central

Levi, Benjamin; Brugman, Samantha; Wong, Victor W; Grova, Monica; Longaker, Michael T

2011-01-01

Cleft palate represents the second most common birth defect and carries substantial physiologic and social challenges for affected patients, as they often require multiple surgical interventions during their lifetime. A number of genes have been identified to be associated with the cleft palate phenotype, but etiology in the majority of cases remains elusive. In order to better understand cleft palate and both surgical and potential tissue engineering approaches for repair, we have performed an in-depth literature review into cleft palate development in humans and mice, as well as into molecular pathways underlying these pathologic developments. We summarize the multitude of pathways underlying cleft palate development, with the transforming growth factor β superfamily being the most commonly studied. Furthermore, while the majority of cleft palate studies are performed using a mouse model, studies focusing on tissue engineering have also focused heavily on mouse models. A paucity of human randomized controlled studies exists for cleft palate repair, and so far, tissue engineering approaches are limited. In this review, we discuss the development of the palate, explain the basic science behind normal and pathologic palate development in humans as well as mouse models and elaborate on how these studies may lead to future advances in palatal tissue engineering and cleft palate treatments. PMID:21964245

Correlations of Behavioral Deficits with Brain Pathology Assessed through Longitudinal MRI and Histopathology in the HdhQ150/Q150 Mouse Model of Huntington’s Disease

PubMed Central

Rattray, Ivan; Smith, Edward J.; Crum, William R.; Walker, Thomas A.; Gale, Richard; Bates, Gillian P.

2017-01-01

A variety of mouse models have been developed that express mutant huntingtin (mHTT) leading to aggregates and inclusions that model the molecular pathology observed in Huntington’s disease. Here we show that although homozygous HdhQ150 knock-in mice developed motor impairments (rotarod, locomotor activity, grip strength) by 36 weeks of age, cognitive dysfunction (swimming T maze, fear conditioning, odor discrimination, social interaction) was not evident by 94 weeks. Concomitant to behavioral assessments, T2-weighted MRI volume measurements indicated a slower striatal growth with a significant difference between wild type (WT) and HdhQ150 mice being present even at 15 weeks. Indeed, MRI indicated significant volumetric changes prior to the emergence of the “clinical horizon” of motor impairments at 36 weeks of age. A striatal decrease of 27% was observed over 94 weeks with cortex (12%) and hippocampus (21%) also indicating significant atrophy. A hypothesis-free analysis using tensor-based morphometry highlighted further regions undergoing atrophy by contrasting brain growth and regional neurodegeneration. Histology revealed the widespread presence of mHTT aggregates and cellular inclusions. However, there was little evidence of correlations between these outcome measures, potentially indicating that other factors are important in the causal cascade linking the molecular pathology to the emergence of behavioral impairments. In conclusion, the HdhQ150 mouse model replicates many aspects of the human condition, including an extended pre-manifest period prior to the emergence of motor impairments. PMID:28099507

A mouse model for MERS coronavirus-induced acute respiratory distress syndrome.

PubMed

Cockrell, Adam S; Yount, Boyd L; Scobey, Trevor; Jensen, Kara; Douglas, Madeline; Beall, Anne; Tang, Xian-Chun; Marasco, Wayne A; Heise, Mark T; Baric, Ralph S

2016-11-28

Middle East respiratory syndrome coronavirus (MERS-CoV) is a novel virus that emerged in 2012, causing acute respiratory distress syndrome (ARDS), severe pneumonia-like symptoms and multi-organ failure, with a case fatality rate of ∼36%. Limited clinical studies indicate that humans infected with MERS-CoV exhibit pathology consistent with the late stages of ARDS, which is reminiscent of the disease observed in patients infected with severe acute respiratory syndrome coronavirus. Models of MERS-CoV-induced severe respiratory disease have been difficult to achieve, and small-animal models traditionally used to investigate viral pathogenesis (mouse, hamster, guinea-pig and ferret) are naturally resistant to MERS-CoV. Therefore, we used CRISPR-Cas9 gene editing to modify the mouse genome to encode two amino acids (positions 288 and 330) that match the human sequence in the dipeptidyl peptidase 4 receptor, making mice susceptible to MERS-CoV infection and replication. Serial MERS-CoV passage in these engineered mice was then used to generate a mouse-adapted virus that replicated efficiently within the lungs and evoked symptoms indicative of severe ARDS, including decreased survival, extreme weight loss, decreased pulmonary function, pulmonary haemorrhage and pathological signs indicative of end-stage lung disease. Importantly, therapeutic countermeasures comprising MERS-CoV neutralizing antibody treatment or a MERS-CoV spike protein vaccine protected the engineered mice against MERS-CoV-induced ARDS.

Reversal of autophagy dysfunction in the TgCRND8 mouse model of Alzheimer's disease ameliorates amyloid pathologies and memory deficits.

PubMed

Yang, Dun-Sheng; Stavrides, Philip; Mohan, Panaiyur S; Kaushik, Susmita; Kumar, Asok; Ohno, Masuo; Schmidt, Stephen D; Wesson, Daniel; Bandyopadhyay, Urmi; Jiang, Ying; Pawlik, Monika; Peterhoff, Corrinne M; Yang, Austin J; Wilson, Donald A; St George-Hyslop, Peter; Westaway, David; Mathews, Paul M; Levy, Efrat; Cuervo, Ana M; Nixon, Ralph A

2011-01-01

Autophagy, a major degradative pathway for proteins and organelles, is essential for survival of mature neurons. Extensive autophagic-lysosomal pathology in Alzheimer's disease brain contributes to Alzheimer's disease pathogenesis, although the underlying mechanisms are not well understood. Here, we identified and characterized marked intraneuronal amyloid-β peptide/amyloid and lysosomal system pathology in the Alzheimer's disease mouse model TgCRND8 similar to that previously described in Alzheimer's disease brains. We further establish that the basis for these pathologies involves defective proteolytic clearance of neuronal autophagic substrates including amyloid-β peptide. To establish the pathogenic significance of these abnormalities, we enhanced lysosomal cathepsin activities and rates of autophagic protein turnover in TgCRND8 mice by genetically deleting cystatin B, an endogenous inhibitor of lysosomal cysteine proteases. Cystatin B deletion rescued autophagic-lysosomal pathology, reduced abnormal accumulations of amyloid-β peptide, ubiquitinated proteins and other autophagic substrates within autolysosomes/lysosomes and reduced intraneuronal amyloid-β peptide. The amelioration of lysosomal function in TgCRND8 markedly decreased extracellular amyloid deposition and total brain amyloid-β peptide 40 and 42 levels, and prevented the development of deficits of learning and memory in fear conditioning and olfactory habituation tests. Our findings support the pathogenic significance of autophagic-lysosomal dysfunction in Alzheimer's disease and indicate the potential value of restoring normal autophagy as an innovative therapeutic strategy for Alzheimer's disease.

Longitudinal variations of brain functional connectivity: A case report study based on a mouse model of epilepsy.

PubMed

Erramuzpe, A; Encinas, J M; Sierra, A; Maletic-Savatic, M; Brewster, A L; Anderson, Anne E; Stramaglia, S; Cortes, Jesus M

2015-01-01

Brain Functional Connectivity (FC) quantifies statistical dependencies between areas of the brain. FC has been widely used to address altered function of brain circuits in control conditions compared to different pathological states, including epilepsy, a major neurological disorder. However, FC also has the as yet unexplored potential to help us understand the pathological transformation of the brain circuitry. Our hypothesis is that FC can differentiate global brain interactions across a time-scale of days. To this end, we present a case report study based on a mouse model for epilepsy and analyze longitudinal intracranial electroencephalography data of epilepsy to calculate FC changes from the initial insult (status epilepticus) and over the latent period, when epileptogenic networks emerge, and at chronic epilepsy, when unprovoked seizures occur as spontaneous events. We found that the overall network FC at low frequency bands decreased immediately after status epilepticus was provoked, and increased monotonously later on during the latent period. Overall, our results demonstrate the capacity of FC to address longitudinal variations of brain connectivity across the establishment of pathological states.

Mouse Models as Tools to Identify Genetic Pathways for Retinal Degeneration, as Exemplified by Leber's Congenital Amaurosis.

PubMed

Chang, Bo

2016-01-01

Leber's congenital amaurosis (LCA) is an inherited retinal degenerative disease characterized by severe loss of vision in the first year of life. In addition to early vision loss, a variety of other eye-related abnormalities including roving eye movements, deep-set eyes, and sensitivity to bright light also occur with this disease. Many animal models of LCA are available and the study them has led to a better understanding of the pathology of the disease, and has led to the development of therapeutic strategies aimed at curing or slowing down LCA. Mouse models, with their well-developed genetics and similarity to human physiology and anatomy, serve as powerful tools with which to investigate the etiology of human LCA. Such mice provide reproducible, experimental systems for elucidating pathways of normal development, function, designing strategies and testing compounds for translational research and gene-based therapies aimed at delaying the diseases progression. In this chapter, I describe tools used in the discovery and evaluation of mouse models of LCA including a Phoenix Image-Guided Optical Coherence Tomography (OCT) and a Diagnosys Espion Visual Electrophysiology System. Three mouse models are described, the rd3 mouse model for LCA12 and LCA1, the rd12 mouse model for LCA2, and the rd16 mouse model for LCA10.

Characterisation of a C1qtnf5 Ser163Arg Knock-In Mouse Model of Late-Onset Retinal Macular Degeneration

PubMed Central

Shu, Xinhua; Luhmann, Ulrich F. O.; Aleman, Tomas S.; Barker, Susan E.; Lennon, Alan; Tulloch, Brian; Chen, Mei; Xu, Heping; Jacobson, Samuel G.; Ali, Robin; Wright, Alan F.

2011-01-01

A single founder mutation resulting in a Ser163Arg substitution in the C1QTNF5 gene product causes autosomal dominant late-onset retinal macular degeneration (L-ORMD) in humans, which has clinical and pathological features resembling age-related macular degeneration. We generated and characterised a mouse “knock-in” model carrying the Ser163Arg mutation in the orthologous murine C1qtnf5 gene by site-directed mutagenesis and homologous recombination into mouse embryonic stem cells. Biochemical, immunological, electron microscopic, fundus autofluorescence, electroretinography and laser photocoagulation analyses were used to characterise the mouse model. Heterozygous and homozygous knock-in mice showed no significant abnormality in any of the above measures at time points up to 2 years. This result contrasts with another C1qtnf5 Ser163Arg knock-in mouse which showed most of the features of L-ORMD but differed in genetic background and targeting construct. PMID:22110650

The Ptch1DL mouse: a new model to study lambdoid craniosynostosis and basal cell nevus syndrome associated skeletal defects

PubMed Central

Feng, Weiguo; Choi, Irene; Clouthier, David E.; Niswander, Lee; Williams, Trevor

2013-01-01

Mouse models provide valuable opportunities for probing the underlying pathology of human birth defects. Employing an ENU-based screen for recessive mutations affecting craniofacial anatomy we isolated a mouse strain, Dogface-like (DL), with abnormal skull and snout morphology. Examination of the skull indicated that these mice developed craniosynostosis of the lambdoid suture. Further analysis revealed skeletal defects related to the pathology of basal cell nevus syndrome (BCNS) including defects in development of the limbs, scapula, ribcage, secondary palate, cranial base, and cranial vault. In humans, BCNS is often associated with mutations in the Hedgehog receptor PTCH1 and genetic mapping in DL identified a point mutation at a splice donor site in Ptch1. Using genetic complementation analysis we determined that DL is a hypomorphic allele of Ptch1, leading to increased Hedgehog signaling. Two aberrant transcripts are generated by the mutated Ptch1DL gene, which would be predicted to reduce significantly the levels of functional Patched1 protein. This new Ptch1 allele broadens the mouse genetic reagents available to study the Hedgehog pathway and provides a valuable means to study the underlying skeletal abnormalities in BCNS. In addition, these results strengthen the connection between elevated Hedgehog signaling and craniosynostosis. PMID:23897749

Ultrastructural study of Rift Valley fever virus in the mouse model

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

Reed, Christopher; Steele, Keith E.; Honko, Anna

Detailed ultrastructural studies of Rift Valley fever virus (RVFV) in the mouse model are needed to develop and characterize a small animal model of RVF for the evaluation of potential vaccines and therapeutics. In this study, the ultrastructural features of RVFV infection in the mouse model were analyzed. The main changes in the liver included the presence of viral particles in hepatocytes and hepatic stem cells accompanied by hepatocyte apoptosis. However, viral particles were observed rarely in the liver; in contrast, particles were extremely abundant in the CNS. Despite extensive lymphocytolysis, direct evidence of viral replication was not observed inmore » the lymphoid tissue. These results correlate with the acute-onset hepatitis and delayed-onset encephalitis that are dominant features of severe human RVF, but suggest that host immune-mediated mechanisms contribute significantly to pathology. The results of this study expand our knowledge of RVFV-host interactions and further characterize the mouse model of RVF.« less

Humanized Mouse Models for the Study of Human Malaria Parasite Biology, Pathogenesis, and Immunity.

PubMed

Minkah, Nana K; Schafer, Carola; Kappe, Stefan H I

2018-01-01

Malaria parasite infection continues to inflict extensive morbidity and mortality in resource-poor countries. The insufficiently understood parasite biology, continuously evolving drug resistance and the lack of an effective vaccine necessitate intensive research on human malaria parasites that can inform the development of new intervention tools. Humanized mouse models have been greatly improved over the last decade and enable the direct study of human malaria parasites in vivo in the laboratory. Nevertheless, no small animal model developed so far is capable of maintaining the complete life cycle of Plasmodium parasites that infect humans. The ultimate goal is to develop humanized mouse systems in which a Plasmodium infection closely reproduces all stages of a parasite infection in humans, including pre-erythrocytic infection, blood stage infection and its associated pathology, transmission as well as the human immune response to infection. Here, we discuss current humanized mouse models and the future directions that should be taken to develop next-generation models for human malaria parasite research.

ASSESSMENT OF ALLERGIC IMMUNE RESPONSES TO INDOOR AIR FUNGAL CONTAMINANTS

EPA Science Inventory

We are using a mouse model to assess immune and inflammatory responses as well as changes in respiratory function and pathology characteristic of allergic asthma to fungal extracts M. anisopliae (MACA), S. chartarum (SCE), and P. chrysogenum (PCE). This model will be useful to a...

Enhancing Autophagy with Drugs or Lung-directed Gene Therapy Reverses the Pathological Effects of Respiratory Epithelial Cell Proteinopathy.

PubMed

Hidvegi, Tunda; Stolz, Donna B; Alcorn, John F; Yousem, Samuel A; Wang, Jieru; Leme, Adriana S; Houghton, A McGarry; Hale, Pamela; Ewing, Michael; Cai, Houming; Garchar, Evelyn Akpadock; Pastore, Nunzia; Annunziata, Patrizia; Kaminski, Naftali; Pilewski, Joseph; Shapiro, Steven D; Pak, Stephen C; Silverman, Gary A; Brunetti-Pierri, Nicola; Perlmutter, David H

2015-12-11

Recent studies have shown that autophagy mitigates the pathological effects of proteinopathies in the liver, heart, and skeletal muscle but this has not been investigated for proteinopathies that affect the lung. This may be due at least in part to the lack of an animal model robust enough for spontaneous pathological effects from proteinopathies even though several rare proteinopathies, surfactant protein A and C deficiencies, cause severe pulmonary fibrosis. In this report we show that the PiZ mouse, transgenic for the common misfolded variant α1-antitrypsin Z, is a model of respiratory epithelial cell proteinopathy with spontaneous pulmonary fibrosis. Intracellular accumulation of misfolded α1-antitrypsin Z in respiratory epithelial cells of the PiZ model resulted in activation of autophagy, leukocyte infiltration, and spontaneous pulmonary fibrosis severe enough to elicit functional restrictive deficits. Treatment with autophagy enhancer drugs or lung-directed gene transfer of TFEB, a master transcriptional activator of the autophagolysosomal system, reversed these proteotoxic consequences. We conclude that this mouse is an excellent model of respiratory epithelial proteinopathy with spontaneous pulmonary fibrosis and that autophagy is an important endogenous proteostasis mechanism and an attractive target for therapy. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

The Regenerative Response of Endogenous Neural Stem/Progenitor Cells to Traumatic Brain Injury

DTIC Science & Technology

2014-06-09

Genevieve M. Sullivan, Molecular and Cell Biology. 2014 Thesis directed by: Dr. Regina C. Armstrong, PhD, APG The complex pathological mechanisms ...treatments for TBI (83 ). Therefore it is necessary to investigate the complex pathological and molecular mechanisms that occur after heterogeneous...of cellular mechanisms that is not an option in other species with gyrencephalic brains. Therefore, even though a mouse model cannot fully replicate

A mouse model of alcoholic liver fibrosis-associated acute kidney injury identifies key molecular pathways

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

Furuya, Shinji; Chappell, Grace A.; Iwata, Yasuhir

Clinical data strongly indicate that acute kidney injury (AKI) is a critical complication in alcoholic hepatitis, an acute-on-chronic form of liver failure in patients with advanced alcoholic fibrosis. Development of targeted therapies for AKI in this setting is hampered by the lack of an animal model. To enable research into molecular drivers and novel therapies for fibrosis- and alcohol-associated AKI, we aimed to combine carbon tetrachloride (CCl{sub 4})-induced fibrosis with chronic intra-gastric alcohol feeding. Male C57BL/6J mice were administered a low dose of CCl{sub 4} (0.2 ml/kg 2 × week/6 weeks) followed by alcohol intragastrically (up to 25 g/kg/day formore » 3 weeks) and with continued CCl{sub 4}. We observed that combined treatment with CCl{sub 4} and alcohol resulted in severe liver injury, more pronounced than using each treatment alone. Importantly, severe kidney injury was evident only in the combined treatment group. This mouse model reproduced distinct pathological features consistent with AKI in human alcoholic hepatitis. Transcriptomic analysis of kidneys revealed profound effects in the combined treatment group, with enrichment for damage-associated pathways, such as apoptosis, inflammation, immune-response and hypoxia. Interestingly, Havcr1 and Lcn2, biomarkers of AKI, were markedly up-regulated. Overall, this study established a novel mouse model of fibrosis- and alcohol-associated AKI and identified key mechanistic pathways. - Highlights: • Acute kidney injury (AKI) is a critical complication in alcoholic hepatitis • We developed a novel mouse model of fibrosis- and alcohol-associated AKI • This model reproduces key molecular and pathological features of human AKI • This animal model can help identify new targeted therapies for alcoholic hepatitis.« less

Tau pathology does not affect experience-driven single-neuron and network-wide Arc/Arg3.1 responses.

PubMed

Rudinskiy, Nikita; Hawkes, Jonathan M; Wegmann, Susanne; Kuchibhotla, Kishore V; Muzikansky, Alona; Betensky, Rebecca A; Spires-Jones, Tara L; Hyman, Bradley T

2014-06-10

Intraneuronal neurofibrillary tangles (NFTs) - a characteristic pathological feature of Alzheimer's and several other neurodegenerative diseases - are considered a major target for drug development. Tangle load correlates well with the severity of cognitive symptoms and mouse models of tauopathy are behaviorally impaired. However, there is little evidence that NFTs directly impact physiological properties of host neurons. Here we used a transgenic mouse model of tauopathy to study how advanced tau pathology in different brain regions affects activity-driven expression of immediate-early gene Arc required for experience-dependent consolidation of long-term memories. We demonstrate in vivo that visual cortex neurons with tangles are as likely to express comparable amounts of Arc in response to structured visual stimulation as their neighbors without tangles. Probability of experience-dependent Arc response was not affected by tau tangles in both visual cortex and hippocampal pyramidal neurons as determined postmortem. Moreover, whole brain analysis showed that network-wide activity-driven Arc expression was not affected by tau pathology in any of the brain regions, including brain areas with the highest tangle load. Our findings suggest that intraneuronal NFTs do not affect signaling cascades leading to experience-dependent gene expression required for long-term synaptic plasticity.

Dysfunctional tubular endoplasmic reticulum constitutes a pathological feature of Alzheimer's disease.

PubMed

Sharoar, M G; Shi, Q; Ge, Y; He, W; Hu, X; Perry, G; Zhu, X; Yan, R

2016-09-01

Pathological features in Alzheimer's brains include mitochondrial dysfunction and dystrophic neurites (DNs) in areas surrounding amyloid plaques. Using a mouse model that overexpresses reticulon 3 (RTN3) and spontaneously develops age-dependent hippocampal DNs, here we report that DNs contain both RTN3 and REEPs, topologically similar proteins that can shape tubular endoplasmic reticulum (ER). Importantly, ultrastructural examinations of such DNs revealed gradual accumulation of tubular ER in axonal termini, and such abnormal tubular ER inclusion is found in areas surrounding amyloid plaques in biopsy samples from Alzheimer's disease (AD) brains. Functionally, abnormally clustered tubular ER induces enhanced mitochondrial fission in the early stages of DN formation and eventual mitochondrial degeneration at later stages. Furthermore, such DNs are abrogated when RTN3 is ablated in aging and AD mouse models. Hence, abnormally clustered tubular ER can be pathogenic in brain regions: disrupting mitochondrial integrity, inducing DNs formation and impairing cognitive function in AD and aging brains.

Development of a Mouse Model of Helicobacter pylori Infection that Mimics Human Disease

NASA Astrophysics Data System (ADS)

Marchetti, Marta; Arico, Beatrice; Burroni, Daniela; Figura, Natale; Rappuoli, Rino; Ghiara, Paolo

1995-03-01

The human pathogen Helicobacter pylori is associated with gastritis, peptic ulcer disease, and gastric cancer. The pathogenesis of H. pylori infection in vivo was studied by adapting fresh clinical isolates of bacteria to colonize the stomachs of mice. A gastric pathology resembling human disease was observed in infections with cytotoxin-producing strains but not with noncytotoxic strains. Oral immunization with purified H. pylori antigens protected mice from bacterial infection. This mouse model will allow the development of therapeutic agents and vaccines against H. pylori infection in humans.

Histologic scoring of gastritis and gastric cancer in mouse models.

PubMed

Rogers, Arlin B

2012-01-01

Histopathology is a defining endpoint in mouse models of experimental gastritis and gastric adenocarcinoma. Presented here is an overview of the histology of gastritis and gastric cancer in mice experimentally infected with Helicobacter pylori or H. felis. A modular histopathologic scoring scheme is provided that incorporates relevant disease-associated changes. Whereas the guide uses Helicobacter infection as the prototype challenge, features may be applied to chemical and genetically engineered mouse models of stomach cancer as well. Specific criteria included in the combined gastric histologic activity index (HAI) include inflammation, epithelial defects, oxyntic atrophy, hyperplasia, pseudopyloric metaplasia, and dysplasia or neoplasia. Representative photomicrographs accompany descriptions for each lesion grade. Differentiation of genuine tumor invasion from pseudoinvasion is highlighted. A brief comparison of normal rodent versus human stomach anatomy and physiology is accompanied by an introduction to mouse-specific lesions including mucous metaplasia and eosinophilic droplets (hyalinosis). In conjunction with qualified pathology support, this guide is intended to assist research scientists, postdoctoral fellows, graduate students, and medical professionals from affiliated disciplines in the interpretation and histologic grading of chronic gastritis and gastric carcinoma in mouse models.

Model - SEO - serious ovarian cancer | Center for Cancer Research

Cancer.gov

Genetically engineered mouse model Developed in house Genetic aberrations: Inactivation of Rb tumor suppression (via K18-T121 transgene) Tp53 loss or mutation (R172H) Brca1 or Brca2 loss Induction by injection of adenovirus expressing Cre recombinase under the ovrian bursa Pathology:

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

Ding, Ying; Adachi, Hiroaki, E-mail: hadachi-ns@umin.org; Department of Neurology, University of Occupational and Environmental Health School of Medicine, 1-1 Iseigaoka, Yahata-nishi-ku, Kitakyushu 807-8555

Spinal and bulbar muscular atrophy (SBMA) is an inherited motor neuron disease caused by the expansion of a polyglutamine (polyQ)-encoding tract within the androgen receptor (AR) gene. The pathologic features of SBMA are motor neuron loss in the spinal cord and brainstem and diffuse nuclear accumulation and nuclear inclusions of mutant AR in residual motor neurons and certain visceral organs. Hepatocyte growth factor (HGF) is a polypeptide growth factor which has neuroprotective properties. To investigate whether HGF overexpression can affect disease progression in a mouse model of SBMA, we crossed SBMA transgenic model mice expressing an AR gene with anmore » expanded CAG repeat with mice overexpressing HGF. Here, we report that high expression of HGF induces Akt phosphorylation and modestly ameliorated motor symptoms in an SBMA transgenic mouse model treated with or without castration. These findings suggest that HGF overexpression can provide a potential therapeutic avenue as a combination therapy with disease-modifying therapies in SBMA. - Highlights: • HGF overexpression ameliorates the motor phenotypes of the SBMA mouse model. • HGF overexpression induces Akt phosphorylation in the SBMA mouse model. • This is the first report of combination therapy in a mouse model of polyQ diseases.« less

Use of Humanized Mice to Study the Pathogenesis of Autoimmune and Inflammatory Diseases

PubMed Central

Koboziev, Iurii; Jones-Hall, Yava; Valentine, John F.; Webb, Cynthia Reinoso; Furr, Kathryn L.; Grisham, Matthew B.

2015-01-01

Animal models of disease have been used extensively by the research community for the past several decades to better understand the pathogenesis of different diseases as well as assess the efficacy and toxicity of different therapeutic agents. Retrospective analyses of numerous preclinical intervention studies using mouse models of acute and chronic inflammatory diseases reveal a generalized failure to translate promising interventions or therapeutics into clinically-effective treatments in patients. Although several possible reasons have been suggested to account for this generalized failure to translate therapeutic efficacy from the laboratory bench to the patient’s bedside, it is becoming increasingly apparent that the mouse immune system may not adequately recapitulate the immuno-pathological mechanisms observed in human diseases. Indeed, it is well-known that >80 major differences exist between mouse and human immunology; all of which contribute to significant differences in immune system development, activation and responses to challenges in innate and adaptive immunity. This inconvenient reality has prompted investigators to attempt to humanize the mouse immune system in order to address important, human-specific questions that are impossible to study in patients. The successful long-term engraftment of human hemato-lymphoid cells in mice would provide investigators with a relatively inexpensive, small animal model to study clinically-relevant mechanisms as well as facilitate the evaluation of human-specific therapies in vivo. The discovery that targeted mutation of the IL-2 receptor common gamma chain in lymphopenic mice allows for the long-term engraftment of functional human immune cells has advanced greatly our ability to humanize the mouse immune system. The objective of this review is to present a brief overview of the recent advances that have been made in the development and use of humanized mice with special emphasis on autoimmune and chronic inflammatory diseases. In addition, we discuss current challenges and possible solutions for utilizing these unique mouse models to define the human-specific immuno-pathological mechanisms responsible for the induction and perpetuation of chronic gut inflammation. PMID:26035036

The role of vertebrate models in understanding craniosynostosis.

PubMed

Holmes, Greg

2012-09-01

Craniosynostosis (CS), the premature fusion of cranial sutures, is a relatively common pediatric anomaly, occurring in isolation or as part of a syndrome. A growing number of genes with pathologic mutations have been identified for syndromic and nonsyndromic CS. The study of human sutural material obtained post-operatively is not sufficient to understand the etiology of CS, for which animal models are indispensable. The similarity of the human and murine calvarial structure, our knowledge of mouse genetics and biology, and ability to manipulate the mouse genome make the mouse the most valuable model organism for CS research. A variety of mouse mutants are available that model specific human CS mutations or have CS phenotypes. These allow characterization of the biochemical and morphological events, often embryonic, which precede suture fusion. Other vertebrate organisms have less functional genetic utility than mice, but the rat, rabbit, chick, zebrafish, and frog provide alternative systems in which to validate or contrast molecular functions relevant to CS.

Quantification of oxygen-induced retinopathy in the mouse: a model of vessel loss, vessel regrowth and pathological angiogenesis

PubMed Central

Connor, Kip M; Krah, Nathan M; Dennison, Roberta J; Aderman, Christopher M; Chen, Jing; Guerin, Karen I; Sapieha, Przemyslaw; Stahl, Andreas; Willett, Keirnan L; Smith, Lois E H

2013-01-01

The mouse model of oxygen-induced retinopathy (OIR) has been widely used in studies related to retinopathy of prematurity, proliferative diabetic retinopathy and in studies evaluating the efficacy of antiangiogenic compounds. In this model, 7-d-old (P7) mouse pups with nursing mothers are subjected to hyperoxia (75% oxygen) for 5 d, which inhibits retinal vessel growth and causes significant vessel loss. on P12, mice are returned to room air and the hypoxic avascular retina triggers both normal vessel regrowth and retinal neovascularization (NV), which is maximal at P17. neovascularization spontaneously regresses between P17 and P25. although the OIR model has been the cornerstone of studies investigating proliferative retinopathies, there is currently no harmonized protocol to assess aspects of angiogenesis and treatment outcome. In this protocol we describe standards for mouse size, sample size, retinal preparation, quantification of vascular loss, vascular regrowth, NV and neovascular regression. PMID:19816419

Biology and therapy of inherited retinal degenerative disease: insights from mouse models

PubMed Central

Veleri, Shobi; Lazar, Csilla H.; Chang, Bo; Sieving, Paul A.; Banin, Eyal; Swaroop, Anand

2015-01-01

Retinal neurodegeneration associated with the dysfunction or death of photoreceptors is a major cause of incurable vision loss. Tremendous progress has been made over the last two decades in discovering genes and genetic defects that lead to retinal diseases. The primary focus has now shifted to uncovering disease mechanisms and designing treatment strategies, especially inspired by the successful application of gene therapy in some forms of congenital blindness in humans. Both spontaneous and laboratory-generated mouse mutants have been valuable for providing fundamental insights into normal retinal development and for deciphering disease pathology. Here, we provide a review of mouse models of human retinal degeneration, with a primary focus on diseases affecting photoreceptor function. We also describe models associated with retinal pigment epithelium dysfunction or synaptic abnormalities. Furthermore, we highlight the crucial role of mouse models in elucidating retinal and photoreceptor biology in health and disease, and in the assessment of novel therapeutic modalities, including gene- and stem-cell-based therapies, for retinal degenerative diseases. PMID:25650393

A Progressive Translational Mouse Model of Human VCP Disease: The VCP R155H/+ Mouse

PubMed Central

Nalbandian, Angèle; Llewellyn, Katrina J.; Badadani, Mallikarjun; Yin, Hong Z.; Nguyen, Christopher; Katheria, Veeral; Watts, Giles; Mukherjee, Jogeshwar; Vesa, Jouni; Caiozzo, Vincent; Mozaffar, Tahseen; Weiss, John H.; Kimonis, Virginia E.

2012-01-01

Introduction Mutations in the valosin containing protein (VCP) gene cause hereditary Inclusion Body Myopathy (hIBM) associated with Paget disease of bone (PDB), and frontotemporal dementia (FTD). More recently they have been linked to 2% of familial ALS cases. A knock-in mouse model offers the opportunity to study VCP-associated pathogenesis. Methods The VCPR155H/+ knock-in mouse model was assessed for muscle strength, immunohistochemical, Western, apoptosis, autophagy and MicroPET/CT imaging analyses. Results VCPR155H/+ mice developed significant progressive muscle weakness, and the quadriceps and brain developed progressive cytoplasmic accumulation of TDP-43, ubiquitin-positive inclusion bodies and increased LC3-II staining. MicroCT analyses revealed Paget-like lesions at the ends of long bones. Spinal cord demonstrated neurodegenerative changes, ubiquitin, and TDP-43 pathology of motor neurons. Discussion VCPR155H/+ knock-in mice represent an excellent pre-clinical model for understanding VCP-associated disease mechanisms and future treatments. PMID:23169451

Early fear memory defects are associated with altered synaptic plasticity and molecular architecture in the TgCRND8 Alzheimer's disease mouse model.

PubMed

Steele, John W; Brautigam, Hannah; Short, Jennifer A; Sowa, Allison; Shi, Mengxi; Yadav, Aniruddha; Weaver, Christina M; Westaway, David; Fraser, Paul E; St George-Hyslop, Peter H; Gandy, Sam; Hof, Patrick R; Dickstein, Dara L

2014-07-01

Alzheimer's disease (AD) is a complex and slowly progressing dementing disorder that results in neuronal and synaptic loss, deposition in brain of aberrantly folded proteins, and impairment of spatial and episodic memory. Most studies of mouse models of AD have employed analyses of cognitive status and assessment of amyloid burden, gliosis, and molecular pathology during disease progression. Here we sought to understand the behavioral, cellular, ultrastructural, and molecular changes that occur at a pathological stage equivalent to the early stages of human AD. We studied the TgCRND8 mouse, a model of aggressive AD amyloidosis, at an early stage of plaque pathology (3 months of age) in comparison to their wildtype littermates and assessed changes in cognition, neuron and spine structure, and expression of synaptic glutamate receptor proteins. We found that, at this age, TgCRND8 mice display substantial plaque deposition in the neocortex and hippocampus and impairment on cued and contextual memory tasks. Of particular interest, we also observed a significant decrease in the number of neurons in the hippocampus. Furthermore, analysis of CA1 neurons revealed significant changes in apical and basal dendritic spine types, as well as altered expression of GluN1 and GluA2 receptors. This change in molecular architecture within the hippocampus may reflect a rising representation of inherently less stable thin spine populations, which can cause cognitive decline. These changes, taken together with toxic insults from amyloid-β protein, may underlie the observed neuronal loss. Copyright © 2014 Wiley Periodicals, Inc.

Epidermal growth factor-like domain 7 is a marker of the endothelial lineage and active angiogenesis.

PubMed

Bambino, Kathryn; Lacko, Lauretta A; Hajjar, Katherine A; Stuhlmann, Heidi

2014-07-01

Epidermal growth factor-like domain 7 (Egfl7) expression in the developing embryo is largely restricted to sites of mesodermal progenitors of angioblasts/hemangioblasts and the vascular endothelium. We hypothesize that Egfl7 marks the endothelial lineage during embryonic development, and can be used to define the emergence of endothelial progenitor cells, as well as to visualize newly-forming vasculature in the embryo and during the processes of physiologic and pathologic angiogenesis in the adult. We have generated a transgenic mouse strain that expresses enhanced green fluorescent protein (eGFP) under the control of a minimal Egfl7 regulatory sequence (Egfl7:eGFP). Expression of the transgene recapitulated that of endogenous Egfl7 at sites of vasculogenesis and angiogenesis in the allantois, yolk sac, and in the embryo proper. The transgene was not expressed in the quiescent endothelium of most adult organs. However, the uterus and ovary, which undergo vascular growth and remodeling throughout the estrus cycle, expressed high levels of Egfl7:eGFP. Importantly, expression of the Egfl7:eGFP transgene was induced in adult neovasculature. We also found that increased Egfl7 expression contributed to pathologic revascularization in the mouse retina. To our knowledge, this is the first mouse model that enables monitoring of endothelial cells at sites of active vasculogenesis and angiogenesis. This model also facilitated the isolation and characterization of EGFL7(+) endothelial cell populations by fluorescence activated cell sorting (FACS). Together, our results demonstrate that the Egfl7:eGFP reporter mouse is a valuable tool that can be used to elucidate the mechanisms by which blood vessels form during development and under pathologic circumstances. © 2014 Wiley Periodicals, Inc.

High-fat, high-sugar, and high-cholesterol consumption does not impact tau pathogenesis in a mouse model of Alzheimer's disease-like tau pathology.

PubMed

Gratuze, Maud; Julien, Jacinthe; Morin, Françoise; Calon, Frédéric; Hébert, Sébastien S; Marette, André; Planel, Emmanuel

2016-11-01

Aggregates of hyperphosphorylated tau protein are a pathological hallmark of Alzheimer's disease (AD). The origin of AD is multifactorial, and many metabolic disorders originating from overconsumption of fat, cholesterol, and sugar are associated with higher risk of AD later in life. However, the effects of fat, cholesterol, and sugar overconsumption on tau pathology in AD remain controversial. Using the hTau mice, a model of AD-like tau pathology, we assessed the effects of high-fat, high-cholesterol, and/or high-sugar diets on tau pathogenesis. Surprisingly, we found no effects of these compounds, even combined, on tau phosphorylation, O-GlcNAcylation, splicing, cleavage, and aggregation, suggesting that their overconsumption does not seem to worsen tau pathology in these mice. Crown Copyright © 2016. Published by Elsevier Inc. All rights reserved.

Hepatocellular carcinoma in a mouse model fed a choline-deficient, L-amino acid-defined, high-fat diet.

PubMed

Ikawa-Yoshida, Ayae; Matsuo, Saori; Kato, Atsuhiko; Ohmori, Yusuke; Higashida, Atsuko; Kaneko, Eiji; Matsumoto, Masahiko

2017-08-01

Hepatocellular carcinoma (HCC) is a common cancer worldwide and represents the outcome of the natural history of chronic liver disease. The growing rates of HCC may be partially attributable to increased numbers of people with non-alcoholic fatty liver disease (NAFLD) and non-alcoholic steatohepatitis (NASH). However, details of the liver-specific molecular mechanisms responsible for the NAFLD-NASH-HCC progression remain unclear, and mouse models that can be used to explore the exact factors that influence the progression of NAFLD/NASH to the more chronic stages of liver disease and subsequent HCC are not yet fully established. We have previously reported a choline-deficient, L-amino acid-defined, high-fat diet (CDAHFD) as a dietary NASH model with rapidly progressive liver fibrosis in mice. The current study in C57BL/6J mice fed CDAHFD provided evidence for the chronic persistence of advanced hepatic fibrosis in NASH and disease progression towards HCC in a period of 36 weeks. When mice fed CDAHFD were switched back to a standard diet, hepatic steatosis was normalized and NAFLD activity score improved, but HCC incidence increased and the phenotype of fibrosis-associated HCC development was observed. Moreover, when mice continued to be fed CDAHFD for 60 weeks, HCC further developed without severe body weight loss or carcinogenesis in other organs. The autochthonous tumours showed a variety of histological features and architectural patterns including trabecular, pseudoglandular and solid growth. The CDAHFD mouse model might be a useful tool for studying the development of HCC from NAFLD/NASH, and potentially useful for better understanding pathological changes during hepatocarcinogenesis. © 2017 The Authors. International Journal of Experimental Pathology published by John Wiley & Sons Ltd on behalf of Company of the International Journal of Experimental Pathology (CIJEP).

Early axonal damage and progressive myelin pathology define the kinetics of CNS histopathology in a mouse model of multiple sclerosis.

PubMed

Recks, Mascha S; Stormanns, Eva R; Bader, Jonas; Arnhold, Stefan; Addicks, Klaus; Kuerten, Stefanie

2013-10-01

Studies of MS histopathology are largely dependent on suitable animal models. While light microscopic analysis gives an overview of tissue pathology, it falls short in evaluating detailed changes in nerve fiber morphology. The ultrastructural data presented here and obtained from studies of myelin oligodendrocyte glycoprotein (MOG):35-55-induced experimental autoimmune encephalomyelitis (EAE) in C57BL/6 mice delineate that axonal damage and myelin pathology follow different kinetics in the disease course. While myelin pathology accumulated with disease progression, axonal damage coincided with the initial clinical disease symptoms and remained stable over time. This pattern applied both to irreversible axolysis and early axonal pathology. Notably, these histopathological patterns were reflected by the normal-appearing white matter (NAWM), suggesting that the NAWM is also in an active neurodegenerative state. The data underline the need for neuroprotection in MS and suggest the MOG model as a highly valuable tool for the assessment of different therapeutic strategies. Copyright © 2013 Elsevier Inc. All rights reserved.

Preclinical models of Graves' disease and associated secondary complications.

PubMed

Moshkelgosha, Sajad; So, Po-Wah; Diaz-Cano, Salvador; Banga, J Paul

2015-01-01

Autoimmune thyroid disease is the most common organ-specific autoimmune disorder which consists of two opposing clinical syndromes, Hashimoto's thyroiditis and Graves' (hyperthyroidism) disease. Graves' disease is characterized by goiter, hyperthyroidism, and the orbital complication known as Graves' orbitopathy (GO), or thyroid eye disease. The hyperthyroidism in Graves' disease is caused by stimulation of function of thyrotropin hormone receptor (TSHR), resulting from the production of agonist antibodies to the receptor. A variety of induced mouse models of Graves' disease have been developed over the past two decades, with some reproducible models leading to high disease incidence of autoimmune hyperthyroidism. However, none of the models show any signs of the orbital manifestation of GO. We have recently developed an experimental mouse model of GO induced by immunization of the plasmid encoded ligand binding domain of human TSHR cDNA by close field electroporation that recapitulates the orbital pathology in GO. As in human GO patients, immune mice with hyperthyroid or hypothyroid disease induced by anti-TSHR antibodies exhibited orbital pathology and chemosis, characterized by inflammation of orbital muscles and extensive adipogenesis leading to expansion of the orbital retrobulbar space. Magnetic resonance imaging of the head region in immune mice showed a significant expansion of the orbital space, concurrent with proptosis. This review discusses the different strategies for developing mouse models in Graves' disease, with a particular focus on GO. Furthermore, it outlines how this new model will facilitate molecular investigations into pathophysiology of the orbital disease and evaluation of new therapeutic interventions.

Inoculation of α-synuclein preformed fibrils into the mouse gastrointestinal tract induces Lewy body-like aggregates in the brainstem via the vagus nerve.

PubMed

Uemura, Norihito; Yagi, Hisashi; Uemura, Maiko T; Hatanaka, Yusuke; Yamakado, Hodaka; Takahashi, Ryosuke

2018-05-11

Intraneuronal α-synuclein (α-Syn) aggregates known as Lewy bodies (LBs) and the loss of dopaminergic neurons in the substantia nigra pars compacta (SNpc) are the pathological hallmarks of Parkinson's disease (PD). Braak's hypothesis based on autopsy studies suggests that Lewy pathology initially occurs in the enteric nervous system (ENS) and then travels retrogradely to the dorsal motor nucleus of the vagus nerve (dmX), proceeding from there in a caudo-rostral direction. Recent evidence that α-Syn aggregates propagate between interconnected neurons supports this hypothesis. However, there is no direct evidence demonstrating this transmission from the ENS to the dmX and then to the SNpc. We inoculated α-Syn preformed fibrils (PFFs) or phosphate-buffered saline (PBS) into the mouse gastric wall and analyzed the progression of the pathology. The mice inoculated with α-Syn PFFs, but not with PBS, developed phosphorylated α-Syn (p-α-Syn)-positive LB-like aggregates in the dmX at 45 days postinoculation. This aggregate formation was completely abolished when vagotomy was performed prior to inoculation of α-Syn PFFs, suggesting that the aggregates in the dmX were retrogradely induced via the vagus nerve. Unexpectedly, the number of neurons containing p-α-Syn-positive aggregates in the dmX decreased over time, and no further caudo-rostral propagation beyond the dmX was observed up to 12 months postinoculation. P-α-Syn-positive aggregates were also present in the myenteric plexus at 12 months postinoculation. However, unlike in patients with PD, there was no cell-type specificity in neurons containing those aggregates in this model. These results indicate that α-Syn PFF inoculation into the mouse gastrointestinal tract can induce α-Syn pathology resembling that of very early PD, but other factors are apparently required if further progression of PD pathology is to be replicated in this animal model.

Gad67 haploinsufficiency reduces amyloid pathology and rescues olfactory memory deficits in a mouse model of Alzheimer's disease.

PubMed

Wang, Yue; Wu, Zheng; Bai, Yu-Ting; Wu, Gang-Yi; Chen, Gong

2017-10-10

Alzheimer's disease (AD) is the most common age-related neurodegenerative disorder, affecting millions of people worldwide. Although dysfunction of multiple neurotransmitter systems including cholinergic, glutamatergic and GABAergic systems has been associated with AD progression the underlying mechanisms remain elusive. We and others have recently found that GABA content is elevated in AD brains and linked to cognitive deficits in AD mouse models. The glutamic acid decarboxylase 67 (GAD67) is the major enzyme converting glutamate into GABA and has been implied in a number of neurological disorders such as epilepsy and schizophrenia. However, whether Gad67 is involved in AD pathology has not been well studied. Here, we investigate the functional role of GAD67 in an AD mouse model with Gad67 haploinsufficiency that is caused by replacing one allele of Gad67 with green fluorescent protein (GFP) gene during generation of GAD67-GFP mice. To genetically reduce GAD67 in AD mouse brains, we crossed the Gad67 haploinsufficient mice (GAD67-GFP +/- ) with 5xFAD mice (harboring 5 human familial AD mutations in APP and PS1 genes) to generate a new line of bigenic mice. Immunostaining, ELISA, electrophysiology and behavior test were applied to compare the difference between groups. We found that reduction of GAD67 resulted in a significant decrease of amyloid β production in 5xFAD mice. Concurrently, the abnormal astrocytic GABA and tonic GABA currents, as well as the microglial reactivity were significantly reduced in the 5xFAD mice with Gad67 haploinsufficiency. Importantly, the olfactory memory deficit of 5xFAD mice was rescued by Gad67 haploinsufficiency. Our results demonstrate that GAD67 plays an important role in AD pathology, suggesting that GAD67 may be a potential drug target for modulating the progress of AD.

Behavioral assays with mouse models of Alzheimer’s disease: practical considerations and guidelines

PubMed Central

Puzzo, Daniela; Lee, Linda; Palmeri, Agostino; Calabrese, Giorgio; Arancio, Ottavio

2014-01-01

In Alzheimer’s disease (AD) basic research and drug discovery, mouse models are essential resources for uncovering biological mechanisms, validating molecular targets and screening potential compounds. Both transgenic and non-genetically modified mouse models enable access to different types of AD-like pathology in vivo. Although there is a wealth of genetic and biochemical studies on proposed AD pathogenic pathways, as a disease that centrally features cognitive failure, the ultimate readout for any interventions should be measures of learning and memory. This is particularly important given the lack of knowledge on disease etiology – assessment by cognitive assays offers the advantage of targeting relevant memory systems without requiring assumptions about pathogenesis. A multitude of behavioral assays are available for assessing cognitive functioning in mouse models, including ones specific for hippocampal-dependent learning and memory. Here we review the basics of available transgenic and non-transgenic AD mouse models and detail three well-established behavioral tasks commonly used for testing hippocampal-dependent cognition in mice – contextual fear conditioning, radial arm water maze and Morris water maze. In particular, we discuss the practical considerations, requirements and caveats of these behavioral testing paradigms. PMID:24462904

Thin and open vessel windows for intra-vital fluorescence imaging of murine cochlear blood flow

PubMed Central

Shi, Xiaorui; Zhang, Fei; Urdang, Zachary; Dai, Min; Neng, Lingling; Zhang, Jinhui; Chen, Songlin; Ramamoorthy, Sripriya; Nuttall, Alfred L.

2014-01-01

Normal microvessel structure and function in the cochlea is essential for maintaining the ionic and metabolic homeostasis required for hearing function. Abnormal cochlear microcirculation has long been considered an etiologic factor in hearing disorders. A better understanding of cochlear blood flow (CoBF) will enable more effective amelioration of hearing disorders that result from aberrant blood flow. However, establishing the direct relationship between CoBF and other cellular events in the lateral wall and response to physio-pathological stress remains a challenge due to the lack of feasible interrogation methods and difficulty in accessing the inner ear. Here we report on new methods for studying the CoBF in a mouse model using a thin or open vessel-window in combination with fluorescence intra-vital microscopy (IVM). An open vessel-window enables investigation of vascular cell biology and blood flow permeability, including pericyte (PC) contractility, bone marrow cell migration, and endothelial barrier leakage, in wild type and fluorescent protein-labeled transgenic mouse models with high spatial and temporal resolution. Alternatively, the thin vessel-window method minimizes disruption of the homeostatic balance in the lateral wall and enables study CoBF under relatively intact physiological conditions. A thin vessel-window method can also be used for time-based studies of physiological and pathological processes. Although the small size of the mouse cochlea makes surgery difficult, the methods are sufficiently developed for studying the structural and functional changes in CoBF under normal and pathological conditions. PMID:24780131

Cholinergic degeneration and memory loss delayed by vitamin E in a Down syndrome mouse model

PubMed Central

Lockrow, Jason; Prakasam, Annamalai; Huang, Peng; Bimonte-Nelson, Heather; Sambamurti, Kumar; Granholm, Ann-Charlotte

2009-01-01

Down syndrome (DS) individuals develop several neuropathological hallmarks seen in Alzheimer's disease, including cognitive decline and the early loss of cholinergic markers in the basal forebrain. These deficits are replicated in the Ts65Dn mouse, which contains a partial trisomy of murine chromosome 16, the orthologous genetic segment to human chromosome 21. Oxidative stress levels are elevated early in DS, and may contribute to the neurodegeneration seen in these individuals. We evaluated oxidative stress in Ts65Dn mice, and assessed the efficacy of long-term antioxidant supplementation on memory and basal forebrain pathology. We report that oxidative stress was elevated in the adult Ts65Dn brain, and that supplementation with the antioxidant vitamin E effectively reduced these markers. Also, Ts65Dn mice receiving vitamin E exhibited improved performance on a spatial working memory task and showed an attenuation of cholinergic neuron pathology in the basal forebrain. This study provides evidence that vitamin E delays onset of cognitive and morphological abnormalities in a mouse model of DS, and may represent a safe and effective treatment early in the progression of DS neuropathology. PMID:19135442

Progressive neurologic and somatic disease in a novel mouse model of human mucopolysaccharidosis type IIIC

PubMed Central

Marcó, Sara; Pujol, Anna; Roca, Carles; Motas, Sandra; Ribera, Albert; Garcia, Miguel; Molas, Maria; Villacampa, Pilar; Melia, Cristian S.; Sánchez, Víctor; Sánchez, Xavier; Bertolin, Joan; Ruberte, Jesús; Haurigot, Virginia

2016-01-01

ABSTRACT Mucopolysaccharidosis type IIIC (MPSIIIC) is a severe lysosomal storage disease caused by deficiency in activity of the transmembrane enzyme heparan-α-glucosaminide N-acetyltransferase (HGSNAT) that catalyses the N-acetylation of α-glucosamine residues of heparan sulfate. Enzyme deficiency causes abnormal substrate accumulation in lysosomes, leading to progressive and severe neurodegeneration, somatic pathology and early death. There is no cure for MPSIIIC, and development of new therapies is challenging because of the unfeasibility of cross-correction. In this study, we generated a new mouse model of MPSIIIC by targeted disruption of the Hgsnat gene. Successful targeting left LacZ expression under control of the Hgsnat promoter, allowing investigation into sites of endogenous expression, which was particularly prominent in the CNS, but was also detectable in peripheral organs. Signs of CNS storage pathology, including glycosaminoglycan accumulation, lysosomal distension, lysosomal dysfunction and neuroinflammation were detected in 2-month-old animals and progressed with age. Glycosaminoglycan accumulation and ultrastructural changes were also observed in most somatic organs, but lysosomal pathology seemed most severe in liver. Furthermore, HGSNAT-deficient mice had altered locomotor and exploratory activity and shortened lifespan. Hence, this animal model recapitulates human MPSIIIC and provides a useful tool for the study of disease physiopathology and the development of new therapeutic approaches. PMID:27491071

MPHASYS: a mouse phenotype analysis system

PubMed Central

Calder, R Brent; Beems, Rudolf B; van Steeg, Harry; Mian, I Saira; Lohman, Paul HM; Vijg, Jan

2007-01-01

Background Systematic, high-throughput studies of mouse phenotypes have been hampered by the inability to analyze individual animal data from a multitude of sources in an integrated manner. Studies generally make comparisons at the level of genotype or treatment thereby excluding associations that may be subtle or involve compound phenotypes. Additionally, the lack of integrated, standardized ontologies and methodologies for data exchange has inhibited scientific collaboration and discovery. Results Here we introduce a Mouse Phenotype Analysis System (MPHASYS), a platform for integrating data generated by studies of mouse models of human biology and disease such as aging and cancer. This computational platform is designed to provide a standardized methodology for working with animal data; a framework for data entry, analysis and sharing; and ontologies and methodologies for ensuring accurate data capture. We describe the tools that currently comprise MPHASYS, primarily ones related to mouse pathology, and outline its use in a study of individual animal-specific patterns of multiple pathology in mice harboring a specific germline mutation in the DNA repair and transcription-specific gene Xpd. Conclusion MPHASYS is a system for analyzing multiple data types from individual animals. It provides a framework for developing data analysis applications, and tools for collecting and distributing high-quality data. The software is platform independent and freely available under an open-source license [1]. PMID:17553167

Experimental induction of type 2 diabetes in aging-accelerated mice triggered Alzheimer-like pathology and memory deficits.

PubMed

Mehla, Jogender; Chauhan, Balwantsinh C; Chauhan, Neelima B

2014-01-01

Alzheimer's disease (AD) is an age-dependent neurodegenerative disease constituting ~95% of late-onset non-familial/sporadic AD, and only ~5% accounting for early-onset familial AD. Availability of a pertinent model representing sporadic AD is essential for testing candidate therapies. Emerging evidence indicates a causal link between diabetes and AD. People with diabetes are >1.5-fold more likely to develop AD. Senescence-accelerated mouse model (SAMP8) of accelerated aging displays many features occurring early in AD. Given the role played by diabetes in the pre-disposition of AD, and the utility of SAMP8 non-transgenic mouse model of accelerated aging, we examined if high fat diet-induced experimental type 2 diabetes in SAMP8 mice will trigger pathological aging of the brain. Results showed that compared to non-diabetic SAMP8 mice, diabetic SAMP8 mice exhibited increased cerebral amyloid-β, dysregulated tau-phosphorylating glycogen synthase kinase 3β, reduced synaptophysin immunoreactivity, and displayed memory deficits, indicating Alzheimer-like changes. High fat diet-induced type 2 diabetic SAMP8 mice may represent the metabolic model of AD.

A recombinant lentiviral PDGF-driven mouse model of proneural glioblastoma.

PubMed

Rahme, Gilbert J; Luikart, Bryan W; Cheng, Chao; Israel, Mark A

2018-02-19

Mouse models of glioblastoma (GBM), the most aggressive primary brain tumor, are critical for understanding GBM pathology and can contribute to the preclinical evaluation of therapeutic agents. Platelet-derived growth factor (PDGF) signaling has been implicated in the development and pathogenesis of GBM, specifically the proneural subtype. Although multiple mouse models of PDGF-driven glioma have been described, they require transgenic mice engineered to activate PDGF signaling and/or impair tumor suppressor genes and typically represent lower-grade glioma. We designed recombinant lentiviruses expressing both PDGFB and a short hairpin RNA targeting Cdkn2a to induce gliomagenesis following stereotactic injection into the dentate gyrus of adult immunocompetent mice. We engineered these viruses to coexpress CreERT2 with PDGFB, allowing for deletion of floxed genes specifically in transduced cells, and designed another version of this recombinant lentivirus in which enhanced green fluorescent protein was coexpressed with PDGFB and CreERT2 to visualize transduced cells. The dentate gyrus of injected mice showed hypercellularity one week post-injection and subsequently developed bona fide tumors with the pathologic hallmarks of GBM leading to a median survival of 77 days post-injection. Transcriptomic analysis of these tumors revealed a proneural gene expression signature. Informed by the genetic alterations observed in human GBM, we engineered a novel mouse model of proneural GBM. While reflecting many of the advantages of transgenic mice, this model allows for the facile in vivo testing of gene function in tumor cells and makes possible the rapid production of large numbers of immunocompetent tumor-bearing mice for preclinical testing of therapeutics. © The Author(s) 2017. Published by Oxford University Press on behalf of the Society for Neuro-Oncology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com

Long-Term Overexpression of Hsp70 Does Not Protect against Cardiac Dysfunction and Adverse Remodeling in a MURC Transgenic Mouse Model with Chronic Heart Failure and Atrial Fibrillation

PubMed Central

Bernardo, Bianca C.; Sapra, Geeta; Patterson, Natalie L.; Cemerlang, Nelly; Kiriazis, Helen; Ueyama, Tomomi; Febbraio, Mark A.; McMullen, Julie R.

2015-01-01

Previous animal studies had shown that increasing heat shock protein 70 (Hsp70) using a transgenic, gene therapy or pharmacological approach provided cardiac protection in models of acute cardiac stress. Furthermore, clinical studies had reported associations between Hsp70 levels and protection against atrial fibrillation (AF). AF is the most common cardiac arrhythmia presenting in cardiology clinics and is associated with increased rates of heart failure and stroke. Improved therapies for AF and heart failure are urgently required. Despite promising observations in animal studies which targeted Hsp70, we recently reported that increasing Hsp70 was unable to attenuate cardiac dysfunction and pathology in a mouse model which develops heart failure and intermittent AF. Given our somewhat unexpected finding and the extensive literature suggesting Hsp70 provides cardiac protection, it was considered important to assess whether Hsp70 could provide protection in another mouse model of heart failure and AF. The aim of the current study was to determine whether increasing Hsp70 could attenuate adverse cardiac remodeling, cardiac dysfunction and episodes of arrhythmia in a mouse model of heart failure and AF due to overexpression of Muscle-Restricted Coiled-Coil (MURC). Cardiac function and pathology were assessed in mice at approximately 12 months of age. We report here, that chronic overexpression of Hsp70 was unable to provide protection against cardiac dysfunction, conduction abnormalities, fibrosis or characteristic molecular markers of the failing heart. In summary, elevated Hsp70 may provide protection in acute cardiac stress settings, but appears insufficient to protect the heart under chronic cardiac disease conditions. PMID:26660322

Long-Term Overexpression of Hsp70 Does Not Protect against Cardiac Dysfunction and Adverse Remodeling in a MURC Transgenic Mouse Model with Chronic Heart Failure and Atrial Fibrillation.

PubMed

Bernardo, Bianca C; Sapra, Geeta; Patterson, Natalie L; Cemerlang, Nelly; Kiriazis, Helen; Ueyama, Tomomi; Febbraio, Mark A; McMullen, Julie R

2015-01-01

Previous animal studies had shown that increasing heat shock protein 70 (Hsp70) using a transgenic, gene therapy or pharmacological approach provided cardiac protection in models of acute cardiac stress. Furthermore, clinical studies had reported associations between Hsp70 levels and protection against atrial fibrillation (AF). AF is the most common cardiac arrhythmia presenting in cardiology clinics and is associated with increased rates of heart failure and stroke. Improved therapies for AF and heart failure are urgently required. Despite promising observations in animal studies which targeted Hsp70, we recently reported that increasing Hsp70 was unable to attenuate cardiac dysfunction and pathology in a mouse model which develops heart failure and intermittent AF. Given our somewhat unexpected finding and the extensive literature suggesting Hsp70 provides cardiac protection, it was considered important to assess whether Hsp70 could provide protection in another mouse model of heart failure and AF. The aim of the current study was to determine whether increasing Hsp70 could attenuate adverse cardiac remodeling, cardiac dysfunction and episodes of arrhythmia in a mouse model of heart failure and AF due to overexpression of Muscle-Restricted Coiled-Coil (MURC). Cardiac function and pathology were assessed in mice at approximately 12 months of age. We report here, that chronic overexpression of Hsp70 was unable to provide protection against cardiac dysfunction, conduction abnormalities, fibrosis or characteristic molecular markers of the failing heart. In summary, elevated Hsp70 may provide protection in acute cardiac stress settings, but appears insufficient to protect the heart under chronic cardiac disease conditions.

Novel VCP modulators mitigate major pathologies of rd10, a mouse model of retinitis pigmentosa

PubMed Central

Ikeda, Hanako Ohashi; Sasaoka, Norio; Koike, Masaaki; Nakano, Noriko; Muraoka, Yuki; Toda, Yoshinobu; Fuchigami, Tomohiro; Shudo, Toshiyuki; Iwata, Ayana; Hori, Seiji; Yoshimura, Nagahisa; Kakizuka, Akira

2014-01-01

Neuroprotection may prevent or forestall the progression of incurable eye diseases, such as retinitis pigmentosa, one of the major causes of adult blindness. Decreased cellular ATP levels may contribute to the pathology of this eye disease and other neurodegenerative diseases. Here we describe small compounds (Kyoto University Substances, KUSs) that were developed to inhibit the ATPase activity of VCP (valosin-containing protein), the most abundant soluble ATPase in the cell. Surprisingly, KUSs did not significantly impair reported cellular functions of VCP but nonetheless suppressed the VCP-dependent decrease of cellular ATP levels. Moreover, KUSs, as well as exogenous ATP or ATP-producing compounds, e.g. methylpyruvate, suppressed endoplasmic reticulum stress, and demonstrably protected various types of cultured cells from death, including several types of retinal neuronal cells. We then examined their in vivo efficacies in rd10, a mouse model of retinitis pigmentosa. KUSs prevented photoreceptor cell death and preserved visual function. These results reveal an unexpected, crucial role of ATP consumption by VCP in determining cell fate in this pathological context, and point to a promising new neuroprotective strategy for currently incurable retinitis pigmentosa. PMID:25096051

Imaging the accumulation and suppression of tau pathology using multiparametric MRI

PubMed Central

Holmes, Holly E.; Colgan, Niall; Ismail, Ozama; Ma, Da; Powell, Nick M.; O'Callaghan, James M.; Harrison, Ian F.; Johnson, Ross A.; Murray, Tracey K.; Ahmed, Zeshan; Heggenes, Morton; Fisher, Alice; Cardoso, M.J.; Modat, Marc; Walker-Samuel, Simon; Fisher, Elizabeth M.C.; Ourselin, Sebastien; O'Neill, Michael J.; Wells, Jack A.; Collins, Emily C.; Lythgoe, Mark F.

2016-01-01

Mouse models of Alzheimer's disease have served as valuable tools for investigating pathogenic mechanisms relating to neurodegeneration, including tau-mediated and neurofibrillary tangle pathology—a major hallmark of the disease. In this work, we have used multiparametric magnetic resonance imaging (MRI) in a longitudinal study of neurodegeneration in the rTg4510 mouse model of tauopathy, a subset of which were treated with doxycycline at different time points to suppress the tau transgene. Using this paradigm, we investigated the sensitivity of multiparametric MRI to both the accumulation and suppression of pathologic tau. Tau-related atrophy was discernible from 5.5 months within the cortex and hippocampus. We observed markedly less atrophy in the treated rTg4510 mice, which was enhanced after doxycycline intervention from 3.5 months. We also observed differences in amide proton transfer, cerebral blood flow, and diffusion tensor imaging parameters in the rTg4510 mice, which were significantly less altered after doxycycline treatment. We propose that these non-invasive MRI techniques offer insight into pathologic mechanisms underpinning Alzheimer's disease that may be important when evaluating emerging therapeutics targeting one of more of these processes. PMID:26923415

A metabolic switch toward lipid use in glycolytic muscle is an early pathologic event in a mouse model of amyotrophic lateral sclerosis

PubMed Central

Palamiuc, Lavinia; Schlagowski, Anna; Ngo, Shyuan T; Vernay, Aurelia; Dirrig-Grosch, Sylvie; Henriques, Alexandre; Boutillier, Anne-Laurence; Zoll, Joffrey; Echaniz-Laguna, Andoni; Loeffler, Jean-Philippe; René, Frédérique

2015-01-01

Amyotrophic lateral sclerosis (ALS) is the most common fatal motor neuron disease in adults. Numerous studies indicate that ALS is a systemic disease that affects whole body physiology and metabolic homeostasis. Using a mouse model of the disease (SOD1G86R), we investigated muscle physiology and motor behavior with respect to muscle metabolic capacity. We found that at 65 days of age, an age described as asymptomatic, SOD1G86R mice presented with improved endurance capacity associated with an early inhibition in the capacity for glycolytic muscle to use glucose as a source of energy and a switch in fuel preference toward lipids. Indeed, in glycolytic muscles we showed progressive induction of pyruvate dehydrogenase kinase 4 expression. Phosphofructokinase 1 was inhibited, and the expression of lipid handling molecules was increased. This mechanism represents a chronic pathologic alteration in muscle metabolism that is exacerbated with disease progression. Further, inhibition of pyruvate dehydrogenase kinase 4 activity with dichloroacetate delayed symptom onset while improving mitochondrial dysfunction and ameliorating muscle denervation. In this study, we provide the first molecular basis for the particular sensitivity of glycolytic muscles to ALS pathology. PMID:25820275

Alcoholic Liver Disease: A Mouse Model Reveals Protection by Lactobacillus fermentum

PubMed Central

Barone, Rosario; Rappa, Francesca; Macaluso, Filippo; Caruso Bavisotto, Celeste; Sangiorgi, Claudia; Di Paola, Gaia; Tomasello, Giovanni; Di Felice, Valentina; Marcianò, Vito; Farina, Felicia; Zummo, Giovanni; Conway de Macario, Everly; J.L. Macario, Alberto; Cocchi, Massimo; Cappello, MD, Francesco; Marino Gammazza, Antonella

2016-01-01

Objectives: Alcoholism is one of the most devastating diseases with high incidence, but knowledge of its pathology and treatment is still plagued with gaps mostly because of the inherent limitations of research with patients. We developed an animal model for studying liver histopathology, Hsp (heat-shock protein)-chaperones involvement, and response to treatment. Methods: The system was standardized using mice to which ethanol was orally administered alone or in combination with Lactobacillus fermentum following a precise schedule over time and applying, at predetermined intervals, a battery of techniques (histology, immunohistochemistry, western blotting, real-time PCR, immunoprecipitation, 3-nitrotyrosine labeling) to assess liver pathology (e.g., steatosis, fibrosis), and Hsp60 and iNOS (inducible form of nitric oxide synthase) gene expression and protein levels, and post-translational modifications. Results: Typical ethanol-induced liver pathology occurred and the effect of the probiotic could be reliably monitored. Steatosis score, iNOS levels, and nitrated proteins (e.g., Hsp60) decreased after probiotic intake. Conclusions: We describe a mouse model useful for studying liver disease induced by chronic ethanol intake and for testing pertinent therapeutic agents, e.g., probiotics. We tested L. fermentum, which reduced considerably ethanol-induced tissue damage and deleterious post-translational modifications of the chaperone Hsp60. The model is available to test other agents and probiotics with therapeutic potential in alcoholic liver disease. PMID:26795070

Mouse models for pathogenic African trypanosomes: unravelling the immunology of host-parasite-vector interactions.

PubMed

Magez, S; Caljon, G

2011-08-01

African trypanosomiasis is a parasitic disease that affects a variety of mammals, including humans, on the sub-Saharan African continent. To understand the diverse parameters that govern the host-parasite-vector interactions, mouse models for the disease have proven to be a cornerstone. Despite the fact that most trypanosomes cannot be considered natural pathogens for rodents, experimental infections in mice have shed a tremendous amount of light on the general biology of these parasites and their interaction with and evasion of the mammalian immune system. Different aspects including inflammation, vaccine failure, antigenic variation, resistance/sensitivity to normal human serum and the influence of tsetse compounds on parasite transmission have all been addressed using mouse models. In more recent years, the introduction of various 'knock-out' mouse strains has allowed to analyse the implication of various cytokines, particularly TNF, IFNγ and IL-10, in the regulation of parasitaemia and induction of pathological conditions during infection. © 2011 Blackwell Publishing Ltd.

Purification and Characterization of Mouse Soluble Receptor for Advanced Glycation End Products (sRAGE)*

PubMed Central

Hanford, Lana E.; Enghild, Jan J.; Valnickova, Zuzana; Petersen, Steen V.; Schaefer, Lisa M.; Schaefer, Todd M.; Reinhart, Todd A.; Oury, Tim D.

2007-01-01

The receptor for advanced glycation end products (RAGE) is a member of the immunoglobulin superfamily of cell surface proteins that has been implicated as a progression factor in a number of pathologic conditions from chronic inflammation to cancer to Alzheimer’s disease. In such conditions, RAGE acts to facilitate pathogenic processes. Its secreted isoform, soluble RAGE or sRAGE, has the ability to prevent RAGE signaling by acting as a decoy. sRAGE has been used successfully in animal models of a range of diseases to antagonize RAGE-mediated pathologic processes. In humans, sRAGE results from alternative splicing of RAGE mRNA. This study was aimed to determine whether the same holds true for mouse sRAGE and, in addition, to biochemically characterize mouse sRAGE. The biochemical characteristics examined include glycosylation and disulfide patterns. In addition, sRAGE was found to bind heparin, which may mediate its distribution in the extracellular matrix and cell surfaces of tissues. Finally, our data indicated that sRAGE in the mouse is likely produced by carboxyl-terminal truncation, in contrast to the alternative splicing mechanism reported in humans. PMID:15381690

Adaptive evolution influences the infectious dose of MERS-CoV necessary to achieve severe respiratory disease.

PubMed

Douglas, Madeline G; Kocher, Jacob F; Scobey, Trevor; Baric, Ralph S; Cockrell, Adam S

2018-04-01

We recently established a mouse model (288-330 +/+ ) that developed acute respiratory disease resembling human pathology following infection with a high dose (5 × 10 6 PFU) of mouse-adapted MERS-CoV (icMERSma1). Although this high dose conferred fatal respiratory disease in mice, achieving similar pathology at lower viral doses may more closely reflect naturally acquired infections. Through continued adaptive evolution of icMERSma1 we generated a novel mouse-adapted MERS-CoV (maM35c4) capable of achieving severe respiratory disease at doses between 10 3 and 10 5 PFU. Novel mutations were identified in the maM35c4 genome that may be responsible for eliciting etiologies of acute respiratory distress syndrome at 10-1000 fold lower viral doses. Importantly, comparative genetics of the two mouse-adapted MERS strains allowed us to identify specific mutations that remained fixed through an additional 20 cycles of adaptive evolution. Our data indicate that the extent of MERS-CoV adaptation determines the minimal infectious dose required to achieve severe respiratory disease. Copyright © 2017 Elsevier Inc. All rights reserved.

MYC RNAi-PT Combination Nanotherapy for Metastatic Prostate Cancer Treatment

DTIC Science & Technology

2016-10-01

MYC silencing in BMPC cell line-based allograft tumors by the hybrid NPs. 15. SUBJECT TERMS Nanotechnology , nanoparticle, siRNA delivery, platinum...KEYWORDS Nanotechnology , lipid, polymer, hybrid nanoparticle, siRNA delivery, platinum, MYC, prostate cancer, drug resistance, mouse model, pathology

Mouse model of plasma cell mastitis.

PubMed

Yu, Jian-jun; Bao, Shan-lin; Yu, Sheng-lin; Zhang, Da-Qing; Loo, Wings T Y; Chow, Louis W C; Su, Li; Cui, Zhen; Chen, Kai; Ma, Li-Qiong; Zhang, Ning; Yu, Hui; Yang, Yun-Zhen; Dong, Yu; Yip, Adrian Y S; Ng, Elizabeth L Y

2012-09-19

Plasma cell mastitis is distinct from the common form of mastitis and clinically resembles breast carcinoma. The lesion occurs in non-lactating young women, and the incidence rate is rising. Surgical resection is the main treatment, but cannot prevent recurrence of the disease. Disfigurement or removal of breast after the operations can cause marked physical and psychological distress. The etiology of plasma cell mastitis is unclear up till now. It is therefore necessary to investigate further the underlying immunological changes of the disease. The lesions of plasma cell mastitis removed from patients through aseptic operation were mixed with normal saline into homogenate tube machine (homogenate tubes were disinfected and sterilized prior to treatment). The mixture was homogenized at medium speed and grinded in ultrasonic cell disruptor. The homogenate obtained was made into oil emulsion with Freund's adjuvant. Thirty female BALB/c mice (6 weeks after sexual maturity) were divided into five groups A-E: group A was blank control; group B was normal saline control; group C was inoculated with 0.02 ml water-in-oil emulsion; group D was inoculated with 0.04 ml water-in-oil emulsion; group E was complete Freund's adjuvant control. Pathology results showed that mouse mammary gland acinar cells remained integral without any abnormal changes observed in control groups A and B. Experimental groups C and D showed dilation of mouse mammary ductal tissue with a large number of epithelial cells and debris in the lumen, and fibrosis around ducts accompanied by large duct cells, neutrophils, lymphocytes, and especially plasma cell infiltration. Pathological changes were observed in 3 (50%) mice and 5 (83.3%) mice in group C and D respectively. In group E, neutrophil infiltration in mammary gland was observed in 5 mice, but neither infiltration of plasma cells nor other abnormal pathological changes were observed. The lesions of patient with plasma cell mastitis could make the female BALB/c mice experience the similar clinical and pathological manifestation. High-dose group can successfully establish a mouse model of plasma cell mastitis.

Investigations into Retinal Pathology in the Early Stages of a Mouse Model of Alzheimer’s Disease

PubMed Central

Chidlow, Glyn; Wood, John P.M.; Manavis, Jim; Finnie, John; Casson, Robert J.

2016-01-01

There is increasing recognition that visual performance is impaired in early stages of Alzheimer’s disease (AD); however, no consensus exists as to the mechanisms underlying this visual dysfunction, in particular regarding the timing, nature, and extent of retinal versus cortical pathology. If retinal pathology presents sufficiently early, it offers great potential as a source of novel biomarkers for disease diagnosis. The current project utilized an array of immunochemical and molecular tools to perform a characterization of retinal pathology in the early stages of disease progression using a well-validated mouse model of AD (APPSWE/PS1ΔE9). Analytical endpoints included examination of aberrant amyloid and tau in the retina, quantification of any neuronal degeneration, delineation of cellular stress responses of neurons and particularly glial cells, and investigation of oxidative stress. Brain, eyes, and optic nerves were taken from transgenic and wild-type mice of 3 to 12 months of age and processed for immunohistochemistry, qPCR, or western immunoblotting. The results revealed robust expression of the human APP transgene in the retinas of transgenic mice, but a lack of identifiable retinal pathology during the period when amyloid deposits were dramatically escalating in the brain. We were unable to demonstrate the presence of amyloid plaques, dystrophic neurites, neuronal loss, macro- or micro-gliosis, aberrant cell cycle re-entry, oxidative stress, tau hyperphosphorylation, or upregulations of proinflammatory cytokines or stress signaling molecules in the retina. The overall results do not support the hypothesis that detectable retinal pathology occurs concurrently with escalating amyloid deposition in the brains of APPSWE/PS1ΔE9 mice. PMID:28035930

Alterations of urinary metabolite profile in model diabetic nephropathy

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

Stec, Donald F.; Wang, Suwan; Stothers, Cody

2015-01-09

Highlights: • {sup 1}H NMR spectroscopy was employed to study urinary metabolite profile in diabetic mouse models. • Mouse urinary metabolome showed major changes that are also found in human diabetic nephropathy. • These models can be new tools to study urinary biomarkers that are relevant to human disease. - Abstract: Countering the diabetes pandemic and consequent complications, such as nephropathy, will require better understanding of disease mechanisms and development of new diagnostic methods. Animal models can be versatile tools in studies of diabetic renal disease when model pathology is relevant to human diabetic nephropathy (DN). Diabetic models using endothelialmore » nitric oxide synthase (eNOS) knock-out mice develop major renal lesions characteristic of human disease. However, it is unknown whether they can also reproduce changes in urinary metabolites found in human DN. We employed Type 1 and Type 2 diabetic mouse models of DN, i.e. STZ-eNOS{sup −/−} C57BLKS and eNOS{sup −/−} C57BLKS db/db, with the goal of determining changes in urinary metabolite profile using proton nuclear magnetic resonance (NMR). Six urinary metabolites with significantly lower levels in diabetic compared to control mice have been identified. Specifically, major changes were found in metabolites from tricarboxylic acid (TCA) cycle and aromatic amino acid catabolism including 3-indoxyl sulfate, cis-aconitate, 2-oxoisocaproate, N-phenyl-acetylglycine, 4-hydroxyphenyl acetate, and hippurate. Levels of 4-hydroxyphenyl acetic acid and hippuric acid showed the strongest reverse correlation to albumin-to-creatinine ratio (ACR), which is an indicator of renal damage. Importantly, similar changes in urinary hydroxyphenyl acetate and hippurate were previously reported in human renal disease. We demonstrated that STZ-eNOS{sup −/−} C57BLKS and eNOS{sup −/−} C57BLKS db/db mouse models can recapitulate changes in urinary metabolome found in human DN and therefore can be useful new tools in metabolomic studies relevant to human pathology.« less

A mouse model of ocular blast injury that induces closed globe anterior and posterior pole damage

PubMed Central

Hines-Beard, Jessica; Marchetta, Jeffrey; Gordon, Sarah; Chaum, Edward; Geisert, Eldon E.; Rex, Tonia S.

2012-01-01

We developed and characterized a mouse model of primary ocular blast injury. The device consists of: a pressurized air tank attached to a regulated paintball gun with a machined barrel; a chamber that protects the mouse from direct injury and recoil, while exposing the eye; and a secure platform that enables fine, controlled movement of the chamber in relation to the barrel. Expected pressures were calculated and the optimal pressure transducer, based on the predicted pressures, was positioned to measure output pressures at the location where the mouse eye would be placed. Mice were exposed to one of three blast pressures (23.6, 26.4, or 30.4psi). Gross pathology, intraocular pressure, optical coherence tomography, and visual acuity were assessed 0, 3, 7, 14, and 28 days after exposure. Contralateral eyes and non-blast exposed mice were used as controls. We detected increased damage with increased pressures and a shift in the damage profile over time. Gross pathology included corneal edema, corneal abrasions, and optic nerve avulsion. Retinal damage was detected by optical coherence tomography and a deficit in visual acuity was detected by optokinetics. Our findings are comparable to those identified in Veterans of the recent wars with closed eye injuries as a result of blast exposure. In summary, this is a relatively simple system that creates injuries with features similar to those seen in patients with ocular blast trauma. This is an important new model for testing the short-term and long-term spectrum of closed globe blast injuries and potential therapeutic interventions. PMID:22504073

Anti-IL17 treatment ameliorates Down syndrome phenotypes in mice.

PubMed

Rueda, Noemí; Vidal, Verónica; García-Cerro, Susana; Narcís, Josep Oriol; Llorens-Martín, María; Corrales, Andrea; Lantigua, Sara; Iglesias, Marcos; Merino, Jesús; Merino, Ramón; Martínez-Cué, Carmen

2018-05-16

Down syndrome (DS) is characterized by structural and functional anomalies that are present prenatally and that lead to intellectual disabilities. Later in life, the cognitive abilities of DS individuals progressively deteriorate due to the development of Alzheimer's disease (AD)-associated neuropathology (i.e., β-amyloid (Aβ) plaques, neurofibrillary tangles (NFTs), neurodegeneration, synaptic pathology, neuroinflammation and increased oxidative stress). Increasing evidence has shown that among these pathological processes, neuroinflammation plays a predominant role in AD etiopathology. In AD mouse models, increased neuroinflammation appears earlier than Aβ plaques and NFTs, and in DS and AD models, neuroinflammation exacerbates the levels of soluble and insoluble Aβ species, favoring neurodegeneration. The Ts65Dn (TS) mouse, the most commonly used murine model of DS, recapitulates many alterations present in both DS and AD individuals, including enhanced neuroinflammation. In this study, we observed an altered neuroinflammatory milieu in the hippocampus of the TS mouse model. Pro-inflammatory mediators that were elevated in the hippocampus of this model included pro-inflammatory cytokine IL17A, which has a fundamental role in mediating brain damage in neuroinflammatory processes. Here, we analyzed the ability of an anti-IL17A antibody to reduce the neuropathological alterations that are present in TS mice during early neurodevelopmental stages (i.e., hippocampal neurogenesis and hypocellularity) or that are aggravated in later-life stages (i.e., cognitive abilities, cholinergic neuronal loss and increased cellular senescence, APP expression, Aβ peptide expression and neuroinflammation). Administration of anti-IL17 for 5 months, starting at the age of 7 months, partially improved the cognitive abilities of the TS mice, reduced the expression of several pro-inflammatory cytokines and the density of activated microglia and normalized the APP and Aβ 1-42 levels in the hippocampi of the TS mice. These results suggest that IL17-mediated neuroinflammation is involved in several AD phenotypes in TS mice and provide a new therapeutic target to reduce these pathological characteristics. Copyright © 2018 Elsevier Inc. All rights reserved.

Local CD34-positive capillaries decrease in mouse models of kidney disease associating with the severity of glomerular and tubulointerstitial lesions.

PubMed

Masum, Md Abdul; Ichii, Osamu; Elewa, Yaser Hosny Ali; Nakamura, Teppei; Kon, Yasuhiro

2017-09-04

The renal vasculature plays important roles in both homeostasis and pathology. In this study, we examined pathological changes in the renal microvascular in mouse models of kidney diseases. Glomerular lesions (GLs) in autoimmune disease-prone male BXSB/MpJ-Yaa (Yaa) mice and tubulointerstitial lesions (TILs) in male C57BL/6 mice subjected to unilateral ureteral obstruction (UUO) for 7 days were studied. Collected kidneys were examined using histopathological techniques. A nonparametric Mann-Whitney U test (P < 0.05) was performed to compare healthy controls and the experimental mice. The Kruskal-Wallis test was used to compare three or more groups, and multiple comparisons were performed using Scheffe's method when significant differences were observed (P < 0.05). Yaa mice developed severe autoimmune glomerulonephritis, and the number of CD34 + glomerular capillaries decreased significantly in GLs compared to that in control mice. However, UUO-treated mice showed severe TILs only, and CD34 + tubulointerstitial capillaries were decreased significantly in TILs with the progression of tubulointerstitial fibrosis compared to those in untreated control kidneys. Infiltrations of B-cells, T-cells, and macrophages increased significantly in the respective lesions of both disease models (P < 0.05). In observations of vascular corrosion casts by scanning electron microscopy and of microfil rubber-perfused thick kidney sections by fluorescence microscopy, segmental absences of capillaries were observed in the GLs and TILs of Yaa and UUO-treated mice, respectively. Further, transmission electron microscopy revealed capillary endothelial injury in the respective lesions of both models. The numbers of CD34 + glomerular and tubulointerstitial capillaries were negatively correlated with all examined parameters in GLs (P < 0.05) and TILs (P < 0.01), respectively. From the analysis of mouse models, we identified inverse pathological correlations between the number of local capillaries in GLs and TILs and the severity of kidney diseases.

REVIEW - Thermal Physiology of Laboratory Mice: Defining Thermoneutrality

EPA Science Inventory

In terms of total number of publications, the laboratory mouse (Mus musculus) has emerged as the most popular test subject in biomedical research. Mice are used as models to study obesity, diabetes, eNS diseases and variety of other pathologies. Mice are classified as homeotherms...

Impaired JIP3-dependent axonal lysosome transport promotes amyloid plaque pathology

PubMed Central

Gowrishankar, Swetha; Wu, Yumei

2017-01-01

Lysosomes robustly accumulate within axonal swellings at Alzheimer’s disease (AD) amyloid plaques. However, the underlying mechanisms and disease relevance of such lysosome accumulations are not well understood. Motivated by these problems, we identified JNK-interacting protein 3 (JIP3) as an important regulator of axonal lysosome transport and maturation. JIP3 knockout mouse neuron primary cultures accumulate lysosomes within focal axonal swellings that resemble the dystrophic axons at amyloid plaques. These swellings contain high levels of amyloid precursor protein processing enzymes (BACE1 and presenilin 2) and are accompanied by elevated Aβ peptide levels. The in vivo importance of the JIP3-dependent regulation of axonal lysosomes was revealed by the worsening of the amyloid plaque pathology arising from JIP3 haploinsufficiency in a mouse model of AD. These results establish the critical role of JIP3-dependent axonal lysosome transport in regulating amyloidogenic amyloid precursor protein processing and support a model wherein Aβ production is amplified by plaque-induced axonal lysosome transport defects. PMID:28784610

Phosphodiesterase 7 inhibitor reduced cognitive impairment and pathological hallmarks in a mouse model of Alzheimer's disease.

PubMed

Perez-Gonzalez, Rocio; Pascual, Consuelo; Antequera, Desiree; Bolos, Marta; Redondo, Miriam; Perez, Daniel I; Pérez-Grijalba, Virginia; Krzyzanowska, Agnieszka; Sarasa, Manuel; Gil, Carmen; Ferrer, Isidro; Martinez, Ana; Carro, Eva

2013-09-01

Elevated levels of amyloid beta (Aβ) peptide, hyperphosphorylation of tau protein, and inflammation are pathological hallmarks in Alzheimer's disease (AD). Phosphodiesterase 7 (PDE7) regulates the inflammatory response through the cyclic adenosine monophosphate signaling cascade, and thus plays a central role in AD. The aim of this study was to evaluate the efficacy of an inhibitor of PDE7, named S14, in a mouse model of AD. We report that APP/Ps1 mice treated daily for 4 weeks with S14 show: (1) significant attenuation in behavioral impairment; (2) decreased brain Aβ deposition; (3) enhanced astrocyte-mediated Aβ degradation; and (4) decreased tau phosphorylation. These effects are mediated via the cyclic adenosine monophosphate/cyclic adenosine monophosphate response element-binding protein signaling pathway, and inactivation of glycogen synthase kinase (GSK)3. Our data support the use of PDE7 inhibitors, and specifically S14, as effective therapeutic agents for the prevention and treatment of AD. Copyright © 2013 Elsevier Inc. All rights reserved.

A chimeric human-mouse model of Sjögren's syndrome.

PubMed

Young, Nicholas A; Wu, Lai-Chu; Bruss, Michael; Kaffenberger, Benjamin H; Hampton, Jeffrey; Bolon, Brad; Jarjour, Wael N

2015-01-01

Despite recent advances in the understanding of Sjögren's Syndrome (SjS), the pathogenic mechanisms remain elusive and an ideal model for early drug discovery is not yet available. To establish a humanized mouse model of SjS, peripheral blood mononuclear cells (PBMCs) from healthy volunteers or patients with SjS were transferred into immunodeficient NOD-scid IL-2rγ(null) mouse recipients to produce chimeric mice. While no difference was observed in the distribution of cells, chimeric mice transferred with PBMCs from SjS patients produced enhanced cytokine levels, most significantly IFN-γ and IL-10. Histological examination revealed enhanced inflammatory responses in the lacrimal and salivary glands of SjS chimeras, as measured by digital image analysis and blinded histopathological scoring. Infiltrates were primarily CD4+, with minimal detection of CD8+ T-cells and B-cells. These results demonstrate a novel chimeric mouse model of human SjS that provides a unique in vivo environment to test experimental therapeutics and investigate T-cell disease pathology. Copyright © 2014. Published by Elsevier Inc.

Endometrial apoptosis and neutrophil infiltration during menstruation exhibits spatial and temporal dynamics that are recapitulated in a mouse model.

PubMed

Armstrong, Gregory M; Maybin, Jacqueline A; Murray, Alison A; Nicol, Moira; Walker, Catherine; Saunders, Philippa T K; Rossi, Adriano G; Critchley, Hilary O D

2017-12-12

Menstruation is characterised by synchronous shedding and restoration of tissue integrity. An in vivo model of menstruation is required to investigate mechanisms responsible for regulation of menstrual physiology and to investigate common pathologies such as heavy menstrual bleeding (HMB). We hypothesised that our mouse model of simulated menstruation would recapitulate the spatial and temporal changes in the inflammatory microenvironment of human menses. Three regulatory events were investigated: cell death (apoptosis), neutrophil influx and cytokine/chemokine expression. Well-characterised endometrial tissues from women were compared with uteri from a mouse model (tissue recovered 0, 4, 8, 24 and 48 h after removal of a progesterone-secreting pellet). Immunohistochemistry for cleaved caspase-3 (CC3) revealed significantly increased staining in human endometrium from late secretory and menstrual phases. In mice, CC3 was significantly increased at 8 and 24 h post-progesterone-withdrawal. Elastase + human neutrophils were maximal during menstruation; Ly6G + mouse neutrophils were maximal at 24 h. Human endometrial and mouse uterine cytokine/chemokine mRNA concentrations were significantly increased during menstrual phase and 24 h post-progesterone-withdrawal respectively. Data from dated human samples revealed time-dependent changes in endometrial apoptosis preceding neutrophil influx and cytokine/chemokine induction during active menstruation. These dynamic changes were recapitulated in the mouse model of menstruation, validating its use in menstrual research.

Identification of disease specific pathways using in vivo SILAC proteomics in dystrophin deficient mdx mouse.

PubMed

Rayavarapu, Sree; Coley, William; Cakir, Erdinc; Jahnke, Vanessa; Takeda, Shin'ichi; Aoki, Yoshitsugu; Grodish-Dressman, Heather; Jaiswal, Jyoti K; Hoffman, Eric P; Brown, Kristy J; Hathout, Yetrib; Nagaraju, Kanneboyina

2013-05-01

Duchenne muscular dystrophy (DMD) is an X-linked neuromuscular disorder caused by a mutation in the dystrophin gene. DMD is characterized by progressive weakness of skeletal, cardiac, and respiratory muscles. The molecular mechanisms underlying dystrophy-associated muscle weakness and damage are not well understood. Quantitative proteomics techniques could help to identify disease-specific pathways. Recent advances in the in vivo labeling strategies such as stable isotope labeling in mouse (SILAC mouse) with (13)C6-lysine or stable isotope labeling in mammals (SILAM) with (15)N have enabled accurate quantitative analysis of the proteomes of whole organs and tissues as a function of disease. Here we describe the use of the SILAC mouse strategy to define the underlying pathological mechanisms in dystrophin-deficient skeletal muscle. Differential SILAC proteome profiling was performed on the gastrocnemius muscles of 3-week-old (early stage) dystrophin-deficient mdx mice and wild-type (normal) mice. The generated data were further confirmed in an independent set of mdx and normal mice using a SILAC spike-in strategy. A total of 789 proteins were quantified; of these, 73 were found to be significantly altered between mdx and normal mice (p < 0.05). Bioinformatics analyses using Ingenuity Pathway software established that the integrin-linked kinase pathway, actin cytoskeleton signaling, mitochondrial energy metabolism, and calcium homeostasis are the pathways initially affected in dystrophin-deficient muscle at early stages of pathogenesis. The key proteins involved in these pathways were validated by means of immunoblotting and immunohistochemistry in independent sets of mdx mice and in human DMD muscle biopsies. The specific involvement of these molecular networks early in dystrophic pathology makes them potential therapeutic targets. In sum, our findings indicate that SILAC mouse strategy has uncovered previously unidentified pathological pathways in mouse models of human skeletal muscle disease.

Identification of Disease Specific Pathways Using in Vivo SILAC Proteomics in Dystrophin Deficient mdx Mouse*

PubMed Central

Rayavarapu, Sree; Coley, William; Cakir, Erdinc; Jahnke, Vanessa; Takeda, Shin'ichi; Aoki, Yoshitsugu; Grodish-Dressman, Heather; Jaiswal, Jyoti K.; Hoffman, Eric P.; Brown, Kristy J.; Hathout, Yetrib; Nagaraju, Kanneboyina

2013-01-01

Duchenne muscular dystrophy (DMD) is an X-linked neuromuscular disorder caused by a mutation in the dystrophin gene. DMD is characterized by progressive weakness of skeletal, cardiac, and respiratory muscles. The molecular mechanisms underlying dystrophy-associated muscle weakness and damage are not well understood. Quantitative proteomics techniques could help to identify disease-specific pathways. Recent advances in the in vivo labeling strategies such as stable isotope labeling in mouse (SILAC mouse) with 13C6-lysine or stable isotope labeling in mammals (SILAM) with 15N have enabled accurate quantitative analysis of the proteomes of whole organs and tissues as a function of disease. Here we describe the use of the SILAC mouse strategy to define the underlying pathological mechanisms in dystrophin-deficient skeletal muscle. Differential SILAC proteome profiling was performed on the gastrocnemius muscles of 3-week-old (early stage) dystrophin-deficient mdx mice and wild-type (normal) mice. The generated data were further confirmed in an independent set of mdx and normal mice using a SILAC spike-in strategy. A total of 789 proteins were quantified; of these, 73 were found to be significantly altered between mdx and normal mice (p < 0.05). Bioinformatics analyses using Ingenuity Pathway software established that the integrin-linked kinase pathway, actin cytoskeleton signaling, mitochondrial energy metabolism, and calcium homeostasis are the pathways initially affected in dystrophin-deficient muscle at early stages of pathogenesis. The key proteins involved in these pathways were validated by means of immunoblotting and immunohistochemistry in independent sets of mdx mice and in human DMD muscle biopsies. The specific involvement of these molecular networks early in dystrophic pathology makes them potential therapeutic targets. In sum, our findings indicate that SILAC mouse strategy has uncovered previously unidentified pathological pathways in mouse models of human skeletal muscle disease. PMID:23297347

Deletion of Galgt2 (B4Galnt2) Reduces Muscle Growth in Response to Acute Injury and Increases Muscle Inflammation and Pathology in Dystrophin-Deficient Mice

PubMed Central

Xu, Rui; Singhal, Neha; Serinagaoglu, Yelda; Chandrasekharan, Kumaran; Joshi, Mandar; Bauer, John A.; Janssen, Paulus M.L.; Martin, Paul T.

2016-01-01

Transgenic overexpression of Galgt2 (official name B4Galnt2) in skeletal muscle stimulates the glycosylation of α dystroglycan (αDG) and the up-regulation of laminin α2 and dystrophin surrogates known to inhibit muscle pathology in mouse models of congenital muscular dystrophy 1A and Duchenne muscular dystrophy. Skeletal muscle Galgt2 gene expression is also normally increased in the mdx mouse model of Duchenne muscular dystrophy compared with the wild-type mice. To assess whether this increased endogenous Galgt2 expression could affect disease, we quantified muscular dystrophy measures in mdx mice deleted for Galgt2 (Galgt2−/−mdx). Galgt2−/− mdx mice had increased heart and skeletal muscle pathology and inflammation, and also worsened cardiac function, relative to age-matched mdx mice. Deletion of Galgt2 in wild-type mice also slowed skeletal muscle growth in response to acute muscle injury. In each instance where Galgt2 expression was elevated (developing muscle, regenerating muscle, and dystrophic muscle), Galgt2-dependent glycosylation of αDG was also increased. Overexpression of Galgt2 failed to inhibit skeletal muscle pathology in dystroglycan-deficient muscles, in contrast to previous studies in dystrophin-deficient mdx muscles. This study demonstrates that Galgt2 gene expression and glycosylation of αDG are dynamically regulated in muscle and that endogenous Galgt2 gene expression can ameliorate the extent of muscle pathology, inflammation, and dysfunction in mdx mice. PMID:26435413

Standardization of deep partial-thickness scald burns in C57BL/6 mice

PubMed Central

Medina, Jorge L; Fourcaudot, Andrea B; Sebastian, Eliza A; Shankar, Ravi; Brown, Ammon W; Leung, Kai P

2018-01-01

Mouse burn models are used to understand the wound healing process and having a reproducible model is important. The different protocols used by researchers can lead to differences in depth of partial-thickness burn wounds. Additionally, standardizing a protocol for mouse burns in the laboratory for one strain may result in substantially different results in other strains. In our current study we describe the model development of a deep partial-thickness burn in C57BL/6 mice using hot water scalding as the source of thermal injury. As part of our model development we designed a template with specifications to allow for even contact of bare mouse skin (2×3 cm) with hot water while protecting the rest of the mouse. Burn depth was evaluated with H&E, Masson’s trichrome, and TUNEL staining. Final results were validated with pathology analysis. A water temperature of 54°C with a scalding time of 20 seconds produced consistent deep partial-thickness burns with available equipment described. Other than temperature and time, factors such as template materials and cooling steps after the burn could affect the uniformity of the burns. These findings are useful to burn research by providing some key parameters essential for researchers to simplify the development of their own mouse burn models. PMID:29755839

What has been learned from mouse models of the Fragile X Premutation and Fragile X-associated tremor/ataxia syndrome?

PubMed

Foote, Molly M; Careaga, Milo; Berman, Robert F

2016-08-01

To describe in this review how research using mouse models developed to study the Fragile X premutation (PM) and Fragile X-associated tremor/ataxia syndrome (FXTAS) have contributed to understanding these disorders. PM carriers bear an expanded CGG trinucleotide repeat on the Fragile X Mental Retardation 1 (FMR1) gene, and are at risk for developing the late onset neurodegenerative disorder FXTAS. Much has been learned about these genetic disorders from the development and study of mouse models. This includes new insights into the early cellular and molecular events that occur in PM carriers and in FXTAS, the presence of multiorgan pathology beyond the CNS, immunological dysregulation, unexpected synthesis of a potentially toxic peptide in FXTAS (i.e., FMRpolyG), and evidence that the disease process may be halted or reversed by appropriate molecular therapies given early in the course of disease.

Preclinical Imaging for the Study of Mouse Models of Thyroid Cancer

PubMed Central

Greco, Adelaide; Orlandella, Francesca Maria; Iervolino, Paola Lucia Chiara; Klain, Michele; Salvatore, Giuliana

2017-01-01

Thyroid cancer, which represents the most common tumors among endocrine malignancies, comprises a wide range of neoplasms with different clinical aggressiveness. One of the most important challenges in research is to identify mouse models that most closely resemble human pathology; other goals include finding a way to detect markers of disease that common to humans and mice and to identify the most appropriate and least invasive therapeutic strategies for specific tumor types. Preclinical thyroid imaging includes a wide range of techniques that allow for morphological and functional characterization of thyroid disease as well as targeting and in most cases, this imaging allows quantitative analysis of the molecular pattern of the thyroid cancer. The aim of this review paper is to provide an overview of all of the imaging techniques used to date both for diagnosis and theranostic purposes in mouse models of thyroid cancer. PMID:29258188

High plasticity of axonal pathology in Alzheimer's disease mouse models.

PubMed

Blazquez-Llorca, Lidia; Valero-Freitag, Susana; Rodrigues, Eva Ferreira; Merchán-Pérez, Ángel; Rodríguez, J Rodrigo; Dorostkar, Mario M; DeFelipe, Javier; Herms, Jochen

2017-02-07

Axonal dystrophies (AxDs) are swollen and tortuous neuronal processes that are associated with extracellular depositions of amyloid β (Aβ) and have been observed to contribute to synaptic alterations occurring in Alzheimer's disease. Understanding the temporal course of this axonal pathology is of high relevance to comprehend the progression of the disease over time. We performed a long-term in vivo study (up to 210 days of two-photon imaging) with two transgenic mouse models (dE9xGFP-M and APP-PS1xGFP-M). Interestingly, AxDs were formed only in a quarter of GFP-expressing axons near Aβ-plaques, which indicates a selective vulnerability. AxDs, especially those reaching larger sizes, had long lifetimes and appeared as highly plastic structures with large variations in size and shape and axonal sprouting over time. In the case of the APP-PS1 mouse only, the formation of new long axonal segments in dystrophic axons (re-growth phenomenon) was observed. Moreover, new AxDs could appear at the same point of the axon where a previous AxD had been located before disappearance (re-formation phenomenon). In addition, we observed that most AxDs were formed and developed during the imaging period, and numerous AxDs had already disappeared by the end of this time. This work is the first in vivo study analyzing quantitatively the high plasticity of the axonal pathology around Aβ plaques. We hypothesized that a therapeutically early prevention of Aβ plaque formation or their growth might halt disease progression and promote functional axon regeneration and the recovery of neural circuits.

Early increase and late decrease of purkinje cell dendritic spine density in prion-infected organotypic mouse cerebellar cultures.

PubMed

Campeau, Jody L; Wu, Gengshu; Bell, John R; Rasmussen, Jay; Sim, Valerie L

2013-01-01

Prion diseases are infectious neurodegenerative diseases associated with the accumulation of protease-resistant prion protein, neuronal loss, spongiform change and astrogliosis. In the mouse model, the loss of dendritic spines is one of the earliest pathological changes observed in vivo, occurring 4-5 weeks after the first detection of protease-resistant prion protein in the brain. While there are cell culture models of prion infection, most do not recapitulate the neuropathology seen in vivo. Only the recently developed prion organotypic slice culture assay has been reported to undergo neuronal loss and the development of some aspects of prion pathology, namely small vacuolar degeneration and tubulovesicular bodies. Given the rapid replication of prions in this system, with protease-resistant prion protein detectable by 21 days, we investigated whether the dendritic spine loss and altered dendritic morphology seen in prion disease might also develop within the lifetime of this culture system. Indeed, six weeks after first detection of protease-resistant prion protein in tga20 mouse cerebellar slice cultures infected with RML prion strain, we found a statistically significant loss of Purkinje cell dendritic spines and altered dendritic morphology in infected cultures, analogous to that seen in vivo. In addition, we found a transient but statistically significant increase in Purkinje cell dendritic spine density during infection, at the time when protease-resistant prion protein was first detectable in culture. Our findings support the use of this slice culture system as one which recapitulates prion disease pathology and one which may facilitate study of the earliest stages of prion disease pathogenesis.

Thin and open vessel windows for intra-vital fluorescence imaging of murine cochlear blood flow.

PubMed

Shi, Xiaorui; Zhang, Fei; Urdang, Zachary; Dai, Min; Neng, Lingling; Zhang, Jinhui; Chen, Songlin; Ramamoorthy, Sripriya; Nuttall, Alfred L

2014-07-01

Normal microvessel structure and function in the cochlea is essential for maintaining the ionic and metabolic homeostasis required for hearing function. Abnormal cochlear microcirculation has long been considered an etiologic factor in hearing disorders. A better understanding of cochlear blood flow (CoBF) will enable more effective amelioration of hearing disorders that result from aberrant blood flow. However, establishing the direct relationship between CoBF and other cellular events in the lateral wall and response to physio-pathological stress remains a challenge due to the lack of feasible interrogation methods and difficulty in accessing the inner ear. Here we report on new methods for studying the CoBF in a mouse model using a thin or open vessel-window in combination with fluorescence intra-vital microscopy (IVM). An open vessel-window enables investigation of vascular cell biology and blood flow permeability, including pericyte (PC) contractility, bone marrow cell migration, and endothelial barrier leakage, in wild type and fluorescent protein-labeled transgenic mouse models with high spatial and temporal resolution. Alternatively, the thin vessel-window method minimizes disruption of the homeostatic balance in the lateral wall and enables study CoBF under relatively intact physiological conditions. A thin vessel-window method can also be used for time-based studies of physiological and pathological processes. Although the small size of the mouse cochlea makes surgery difficult, the methods are sufficiently developed for studying the structural and functional changes in CoBF under normal and pathological conditions. Copyright © 2014 Elsevier B.V. All rights reserved.

Ectodysplasin signalling deficiency in mouse models of hypohidrotic ectodermal dysplasia leads to middle ear and nasal pathology

PubMed Central

Azar, Ali; Piccinelli, Chiara; Brown, Helen; Headon, Denis; Cheeseman, Michael

2016-01-01

Hypohidrotic ectodermal dysplasia (HED) results from mutation of the EDA, EDAR or EDARADD genes and is characterized by reduced or absent eccrine sweat glands, hair follicles and teeth, and defective formation of salivary, mammary and craniofacial glands. Mouse models with HED also carry Eda, Edar or Edaradd mutations and have defects that map to the same structures. Patients with HED have ear, nose and throat disease, but this has not been investigated in mice bearing comparable genetic mutations. We report that otitis media, rhinitis and nasopharyngitis occur at high frequency in Eda and Edar mutant mice and explore the pathogenic mechanisms related to glandular function, microbial and immune parameters in these lines. Nasopharynx auditory tube glands fail to develop in HED mutant mice and the functional implications include loss of lysozyme secretion, reduced mucociliary clearance and overgrowth of nasal commensal bacteria accompanied by neutrophil exudation. Heavy nasopharynx foreign body load and loss of gland protection alters the auditory tube gating function and the auditory tubes can become pathologically dilated. Accumulation of large foreign body particles in the bulla stimulates granuloma formation. Analysis of immune cell populations and myeloid cell function shows no evidence of overt immune deficiency in HED mutant mice. Our findings using HED mutant mice as a model for the human condition support the idea that ear and nose pathology in HED patients arises as a result of nasal and nasopharyngeal gland deficits, reduced mucociliary clearance and impaired auditory tube gating function underlies the pathological sequelae in the bulla. PMID:27378689

Progressive Neuronal Pathology and Synaptic Loss Induced by Prediabetes and Type 2 Diabetes in a Mouse Model of Alzheimer's Disease.

PubMed

Ramos-Rodriguez, Juan Jose; Spires-Jones, Tara; Pooler, Amy M; Lechuga-Sancho, Alfonso Maria; Bacskai, Brian J; Garcia-Alloza, Monica

2017-07-01

Age remains the main risk factor for developing Alzheimer's disease (AD) although certain metabolic alterations, including prediabetes and type 2 diabetes (T2D), may also increase this risk. In order to understand this relationship, we have studied an AD-prediabetes mouse model (APP/PS1) with severe hyperinsulinemia induced by long-term high fat diet (HFD), and an AD-T2D model, generated by crossing APP/PS1 and db/db mice (APP/PS1xdb/db). In both, prediabetic and diabetic AD mice, we have analyzed underlying neuronal pathology and synaptic loss. At 26 weeks of age, when both pathologies were clearly established, we observed severe brain atrophy in APP/PS1xdb/db animals as well as cortical thinning, accompanied by increased caspase activity. Reduced senile plaque burden and elevated soluble Aβ40 and 42 levels were observed in AD-T2D mice. Further assessment revealed a significant increase of neurite curvature in prediabetic-AD mice, and this effect was worsened in AD-T2D animals. Synaptic density loss, analyzed by array tomography, revealed a synergistic effect between T2D and AD, whereas an intermediate state was observed, once more, in prediabetic-AD mice. Altogether, our data suggest that early prediabetic hyperinsulinemia may exacerbate AD pathology, and that fully established T2D clearly worsens these effects. Therefore, it is feasible that early detection of prediabetic state and strict metabolic control could slow or delay progression of AD-associated neuropathological features.

Progressive neurologic and somatic disease in a novel mouse model of human mucopolysaccharidosis type IIIC.

PubMed

Marcó, Sara; Pujol, Anna; Roca, Carles; Motas, Sandra; Ribera, Albert; Garcia, Miguel; Molas, Maria; Villacampa, Pilar; Melia, Cristian S; Sánchez, Víctor; Sánchez, Xavier; Bertolin, Joan; Ruberte, Jesús; Haurigot, Virginia; Bosch, Fatima

2016-09-01

Mucopolysaccharidosis type IIIC (MPSIIIC) is a severe lysosomal storage disease caused by deficiency in activity of the transmembrane enzyme heparan-α-glucosaminide N-acetyltransferase (HGSNAT) that catalyses the N-acetylation of α-glucosamine residues of heparan sulfate. Enzyme deficiency causes abnormal substrate accumulation in lysosomes, leading to progressive and severe neurodegeneration, somatic pathology and early death. There is no cure for MPSIIIC, and development of new therapies is challenging because of the unfeasibility of cross-correction. In this study, we generated a new mouse model of MPSIIIC by targeted disruption of the Hgsnat gene. Successful targeting left LacZ expression under control of the Hgsnat promoter, allowing investigation into sites of endogenous expression, which was particularly prominent in the CNS, but was also detectable in peripheral organs. Signs of CNS storage pathology, including glycosaminoglycan accumulation, lysosomal distension, lysosomal dysfunction and neuroinflammation were detected in 2-month-old animals and progressed with age. Glycosaminoglycan accumulation and ultrastructural changes were also observed in most somatic organs, but lysosomal pathology seemed most severe in liver. Furthermore, HGSNAT-deficient mice had altered locomotor and exploratory activity and shortened lifespan. Hence, this animal model recapitulates human MPSIIIC and provides a useful tool for the study of disease physiopathology and the development of new therapeutic approaches. © 2016. Published by The Company of Biologists Ltd.

Inflammation, neurodegeneration and protein aggregation in the retina as ocular biomarkers for Alzheimer's disease in the 3xTg-AD mouse model.

PubMed

Grimaldi, Alfonso; Brighi, Carlo; Peruzzi, Giovanna; Ragozzino, Davide; Bonanni, Valentina; Limatola, Cristina; Ruocco, Giancarlo; Di Angelantonio, Silvia

2018-06-07

Alzheimer's disease (AD) is the most common cause of dementia in the elderly. In the pathogenesis of AD a pivotal role is played by two neurotoxic proteins that aggregate and accumulate in the central nervous system: amyloid beta and hyper-phosphorylated tau. Accumulation of extracellular amyloid beta plaques and intracellular hyper-phosphorylated tau tangles, and consequent neuronal loss begins 10-15 years before any cognitive impairment. In addition to cognitive and behavioral deficits, sensorial abnormalities have been described in AD patients and in some AD transgenic mouse models. Retina can be considered a simple model of the brain, as some pathological changes and therapeutic strategies from the brain may be observed or applicable to the retina. Here we propose new retinal biomarkers that could anticipate the AD diagnosis and help the beginning and the follow-up of possible future treatments. We analyzed retinal tissue of triple-transgenic AD mouse model (3xTg-AD) for the presence of pathological hallmarks during disease progression. We found the presence of amyloid beta plaques, tau tangles, neurodegeneration, and astrogliosis in the retinal ganglion cell layer of 3xTg-AD mice, already at pre-symptomatic stage. Moreover, retinal microglia in pre-symptomatic mice showed a ramified, anti-inflammatory phenotype which, during disease progression, switches to a pro-inflammatory, less ramified one, becoming neurotoxic. We hypothesize retina as a window through which monitor AD-related neurodegeneration process.

Mechanisms of resistance and susceptibility to experimental visceral leishmaniosis: BALB/c mouse versus Syrian hamster model.

PubMed

Nieto, Ana; Domínguez-Bernal, Gustavo; Orden, José A; De La Fuente, Ricardo; Madrid-Elena, Nadia; Carrión, Javier

2011-02-23

Several animal models have been established to study visceral leishmaniosis (VL), a worldwide vector-borne disease affecting humans and domestic animals that constitutes a serious public health problem. BALB/c mice and Syrian hamsters are the most widely used experimental models. In this paper, we summarize the advantages and disadvantages of these two experimental models and discuss the results obtained using these models in different studies of VL. Studies using the BALB/c mouse model have underscored differences between the liver and spleen in the course of VL, indicating that pathological evaluation of the visceral organs is essential for understanding the immune mechanisms induced by Leishmania infantum infection. The main goal of this review is to collate the relevant literature on Leishmania pathogenesis into a sequence of events, providing a schematic view of the main components of adaptive and innate immunity in the liver and spleen after experimental infection with L. infantum or L. donovani. This review also presents several viewpoints and reflections about some controversial aspects of Leishmania research, including the choice of experimental model, route of administration, inoculum size and the relevance of pathology (intimately linked to parasite persistence): a thorough understanding of which is essential for future VL research and the successful development of efficient control strategies for Leishmania spp.

Comprehensive Characterization of the Pyroglutamate Amyloid-β Induced Motor Neurodegenerative Phenotype of TBA2.1 Mice

PubMed Central

Dunkelmann, Tina; Schemmert, Sarah; Honold, Dominik; Teichmann, Kerstin; Butzküven, Elke; Demuth, Hans-Ulrich; Shah, Nadim Joni; Langen, Karl-Josef; Kutzsche, Janine; Willbold, Dieter; Willuweit, Antje

2018-01-01

Alzheimer’s disease (AD) is the most common neurodegenerative disorder and is being intensively investigated using a broad variety of animal models. Many of these models express mutant versions of human amyloid-β protein precursor (AβPP) that are associated with amyloid-β protein (Aβ)-induced early onset familial AD. Most of these models, however, do not develop bold neurodegenerative pathology and the respective phenotypes. Nevertheless, this may well be essential for their suitability to identify therapeutically active compounds that have the potential for a curative or at least disease-modifying therapy in humans. In this study, the new transgenic mouse model TBA2.1 was explored in detail to increase knowledge about the neurodegenerative process induced by the presence of pyroglutamate modified human Aβ3-42 (pEAβ3-42). Analysis of the sensorimotor phenotype, motor coordination, Aβ pathology, neurodegeneration, and gliosis revealed formation and progression of severe pathology and phenotypes including massive neuronal loss in homozygous TBA2.1 mice within a few months. In contrast, the start of a slight phenotype was observed only after 21 months in heterozygous mice. These data highlight the role of pEAβ3-42 in the disease development and progression of AD. Based on the findings of this study, homozygous TBA2.1 mice can be utilized to gain deeper understanding in the underlying mechanisms of pEAβ3-42 and might be suitable as an animal model for treatment studies targeting toxic Aβ species, complementary to the well described transgenic AβPP mouse models. PMID:29578479

A Novel Small Molecule Modulator of Amyloid Pathology.

PubMed

Lovell, Mark A; Lynn, Bert C; Fister, Shuling; Bradley-Whitman, Melissa; Murphy, M Paul; Beckett, Tina L; Norris, Christopher M

2016-05-04

Because traditional approaches to drug development for Alzheimer's disease are becoming increasingly expensive and in many cases disappointingly unsuccessful, alternative approaches are required to shift the paradigm. Following leads from investigations of dihydropyridine calcium channel blockers, we observed unique properties from a class of functionalized naphthyridines and sought to develop these as novel therapeutics that minimize amyloid pathology without the adverse effects associated with current therapeutics. Our data show methyl 2,4-dimethyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridine-1-carboxylate (BNC-1) significantly decreases amyloid burden in a well-established mouse model of amyloid pathology through a unique mechanism mediated by Elk-1, a transcriptional repressor of presenilin-1. Additionally, BNC-1 treatment leads to increased levels of synaptophysin and synapsin, markers of synaptic integrity, but does not adversely impact presenilin-2 or processing of Notch-1, thus avoiding negative off target effects associated with pan-gamma secretase inhibition. Overall, our data show BNC-1 significantly decreases amyloid burden and improves markers of synaptic integrity in a well-established mouse model of amyloid deposition by promoting phosphorylation and activation of Elk-1, a transcriptional repressor of presenilin-1 but not presenilin-2. These data suggest BNC-1 might be a novel, disease-modifying therapeutic that will alter the pathogenesis of Alzheimer's disease.

CD8+IL-17+ T Cells Mediate Neutrophilic Airway Obliteration in T-bet–Deficient Mouse Lung Allograft Recipients

PubMed Central

Dodd-o, Jeffrey M.; Coon, Tiffany A.; Miller, Hannah L.; Ganguly, Sudipto; Popescu, Iulia; O'Donnell, Christopher P.; Cardenes, Nayra; Levine, Melanie; Rojas, Mauricio; Weathington, Nathaniel M.; Zhao, Jing; Zhao, Yutong; McDyer, John F.

2015-01-01

Acute cellular rejection is a known risk factor for the development of obliterative bronchiolitis, which limits the long-term survival of lung transplant recipients. However, the T cell effector mechanisms in both of these processes remain incompletely understood. Using the mouse orthotopic lung transplant model, we investigated whether C57BL/6 T-bet−/− recipients of major histocompatibility complex (MHC)-mismatched BALB/c lung grafts develop rejection pathology and allospecific cytokine responses that differ from wild-type mice. T-bet−/− recipients demonstrated vigorous allograft rejection at 10 days, characterized by neutrophilic inflammation and predominantly CD8+ T cells producing allospecific IL-17 and/or IFN-γ, in contrast to IFN-γ–dominant responses in WT mice. CD4+ T cells produced IL-17 but not IFN-γ responses in T-bet−/− recipients, in contrast to WT controls. Costimulation blockade using anti-CD154 Ab significantly reduced allospecific CD8+IFN-γ+ responses in both T-bet−/− and WT mice but had no attenuating effect on lung rejection pathology in T-bet−/− recipients or on the development of obliterative airway inflammation that occurred only in T-bet−/− recipients. However, neutralization of IL-17A significantly attenuated costimulation blockade–resistant rejection pathology and airway inflammation in T-bet−/− recipients. In addition, CXCL1 (neutrophil chemokine) was increased in T-bet−/− allografts, and IL-17 induced CXCL1 from mouse lung epithelial cells in vitro. Taken together, our data show that T-bet–deficient recipients of complete MHC-mismatched lung allografts develop costimulation blockade–resistant rejection characterized by neutrophilia and obliterative airway inflammation that is predominantly mediated by CD8+IL-17+ T cells. Our data support T-bet–deficient mouse recipients of lung allografts as a viable animal model to study the immunopathogenesis of small airway injury in lung transplantation. PMID:25286244

A genetic and pathologic study of a DENV2 clinical isolate capable of inducing encephalitis and hematological disturbances in immunocompetent mice.

PubMed

Amorim, Jaime Henrique; Pereira Bizerra, Raíza Sales; dos Santos Alves, Rúbens Prince; Sbrogio-Almeida, Maria Elisabete; Levi, José Eduardo; Capurro, Margareth Lara; de Souza Ferreira, Luís Carlos

2012-01-01

Dengue virus (DENV) is the causative agent of dengue fever (DF), a mosquito-borne illness endemic to tropical and subtropical regions. There is currently no effective drug or vaccine formulation for the prevention of DF and its more severe forms, i.e., dengue hemorrhagic fever (DHF) and dengue shock syndrome (DSS). There are two generally available experimental models for the study of DENV pathogenicity as well as the evaluation of potential vaccine candidates. The first model consists of non-human primates, which do not develop symptoms but rather a transient viremia. Second, mouse-adapted virus strains or immunocompromised mouse lineages are utilized, which display some of the pathological features of the infection observed in humans but may not be relevant to the results with regard to the wild-type original virus strains or mouse lineages. In this study, we describe a genetic and pathological study of a DENV2 clinical isolate, named JHA1, which is naturally capable of infecting and killing Balb/c mice and reproduces some of the symptoms observed in DENV-infected subjects. Sequence analyses demonstrated that the JHA1 isolate belongs to the American genotype group and carries genetic markers previously associated with neurovirulence in mouse-adapted virus strains. The JHA1 strain was lethal to immunocompetent mice following intracranial (i.c.) inoculation with a LD(50) of approximately 50 PFU. Mice infected with the JHA1 strain lost weight and exhibited general tissue damage and hematological disturbances, with similarity to those symptoms observed in infected humans. In addition, it was demonstrated that the JHA1 strain shares immunological determinants with the DENV2 NGC reference strain, as evaluated by cross-reactivity of anti-envelope glycoprotein (domain III) antibodies. The present results indicate that the JHA1 isolate may be a useful tool in the study of DENV pathogenicity and will help in the evaluation of anti-DENV vaccine formulations as well as potential therapeutic approaches.

Nicotinamide Forestalls Pathology and Cognitive Decline in Alzheimer Mice: Evidence for Improved Neuronal Bioenergetics and Autophagy Procession

PubMed Central

Liu, Dong; Pitta, Michael; Jiang, Haiyang; Lee, Jong-Hwan; Zhang, Guofeng; Chen, Xinzhi; Kawamoto, Elisa M.; Mattson, Mark P.

2012-01-01

Impaired brain energy metabolism and oxidative stress are implicated in cognitive decline and the pathological accumulations of amyloid β-peptide (Aβ) and hyperphosphorylated Tau (p-Tau) in Alzheimer's disease (AD). To determine whether improving brain energy metabolism will forestall disease progress in AD, the impact of the NAD+ precursor nicotinamide on brain cell mitochondrial function and macroautophagy, bioenergetics-related signaling and cognitive performance were studied in cultured neurons and in a mouse model of AD. Oxidative stress resulted in decreased mitochondrial mass, mitochondrial degeneration and autophagosome accumulation in neurons. Nicotinamide preserved mitochondrial integrity and autophagy function, and reduced neuronal vulnerability to oxidative/metabolic insults and Aβ toxicity. NAD+ biosynthesis, autophagy and PI3K signaling were required for the neuroprotective action of nicotinamide. Treatment of 3xTgAD mice with nicotinamide for 8 months resulted in improved cognitive performance, and reduced Aβ and p-Tau pathologies in hippocampus and cerebral cortex. Nicotinamide treatment preserved mitochondrial integrity, and improved autophagy-lysosome procession by enhancing lysosome/autolysosome acidification to reduce autophagosome accumulation. Treatment of 3xTgAD mice with nicotinamide resulted in elevated levels of activated neuroplasticity-related kinases (Akt and ERKs) and the transcription factor cyclic AMP response element-binding protein in the hippocampus and cerebral cortex. Thus, nicotinamide suppresses AD pathology and cognitive decline in a mouse model of AD by a mechanism involving improved brain bioenergetics with preserved functionality of mitochondria and the autophagy system. PMID:23273573

Protective effects of positive lysosomal modulation in Alzheimer's disease transgenic mouse models.

PubMed

Butler, David; Hwang, Jeannie; Estick, Candice; Nishiyama, Akiko; Kumar, Saranya Santhosh; Baveghems, Clive; Young-Oxendine, Hollie B; Wisniewski, Meagan L; Charalambides, Ana; Bahr, Ben A

2011-01-01

Alzheimer's disease (AD) is an age-related neurodegenerative pathology in which defects in proteolytic clearance of amyloid β peptide (Aβ) likely contribute to the progressive nature of the disorder. Lysosomal proteases of the cathepsin family exhibit up-regulation in response to accumulating proteins including Aβ(1-42). Here, the lysosomal modulator Z-Phe-Ala-diazomethylketone (PADK) was used to test whether proteolytic activity can be enhanced to reduce the accumulation events in AD mouse models expressing different levels of Aβ pathology. Systemic PADK injections in APP(SwInd) and APPswe/PS1ΔE9 mice caused 3- to 8-fold increases in cathepsin B protein levels and 3- to 10-fold increases in the enzyme's activity in lysosomal fractions, while neprilysin and insulin-degrading enzyme remained unchanged. Biochemical analyses indicated the modulation predominantly targeted the active mature forms of cathepsin B and markedly changed Rab proteins but not LAMP1, suggesting the involvement of enhanced trafficking. The modulated lysosomal system led to reductions in both Aβ immunostaining as well as Aβ(x-42) sandwich ELISA measures in APP(SwInd) mice of 10-11 months. More extensive Aβ deposition in 20-22-month APPswe/PS1ΔE9 mice was also reduced by PADK. Selective ELISAs found that a corresponding production of the less pathogenic Aβ(1-38) occurs as Aβ(1-42) levels decrease in the mouse models, indicating that PADK treatment leads to Aβ truncation. Associated with Aβ clearance was the elimination of behavioral and synaptic protein deficits evident in the two transgenic models. These findings indicate that pharmacologically-controlled lysosomal modulation reduces Aβ(1-42) accumulation, possibly through intracellular truncation that also influences extracellular deposition, and in turn offsets the defects in synaptic composition and cognitive functions. The selective modulation promotes clearance at different levels of Aβ pathology and provides proof-of-principle for small molecule therapeutic development for AD and possibly other protein accumulation disorders.

Innate immunity in Alzheimer's disease: the relevance of animal models?

PubMed

Franco Bocanegra, Diana K; Nicoll, James A R; Boche, Delphine

2018-05-01

The mouse is one of the organisms most widely used as an animal model in biomedical research, due to the particular ease with which it can be handled and reproduced in laboratory. As a member of the mammalian class, mice share with humans many features regarding metabolic pathways, cell morphology and anatomy. However, important biological differences between mice and humans exist and must be taken into consideration when interpreting research results, to properly translate evidence from experimental studies into information that can be useful for human disease prevention and/or treatment. With respect to Alzheimer's disease (AD), much of the experimental information currently known about this disease has been gathered from studies using mainly mice as models. Therefore, it is notably important to fully characterise the differences between mice and humans regarding important aspects of the disease. It is now widely known that inflammation plays an important role in the development of AD, a role that is not only a response to the surrounding pathological environment, but rather seems to be strongly implicated in the aetiology of the disease as indicated by the genetic studies. This review highlights relevant differences in inflammation and in microglia, the innate immune cell of the brain, between mice and humans regarding genetics and morphology in normal ageing, and the relationship of microglia with AD-like pathology, the inflammatory profile, and cognition. We conclude that some noteworthy differences exist between mice and humans regarding microglial characteristics, in distribution, gene expression, and states of activation. This may have repercussions in the way that transgenic mice respond to, and influence, the AD-like pathology. However, despite these differences, human and mouse microglia also show similarities in morphology and behaviour, such that the mouse is a suitable model for studying the role of microglia, as long as these differences are taken into consideration when delineating new strategies to approach the study of neurodegenerative diseases.

Brainstem Alzheimer’s-Like Pathology in the Triple Transgenic Mouse Model of Alzheimer’s Disease

PubMed Central

Overk, Cassia R.; Kelley, Christy M.; Mufson, Elliott J.

2011-01-01

The triple transgenic mouse (3xTgAD), harboring human APPSwe, PS1M146V and TauP301L genes, develops age-dependent forebrain intraneuronal Aβ and tau and extraneuronal plaques. We evaluated brainstem AD-like pathology using 6E10, AT8, and Alz50 antibodies and unbiased stereology in young and old 3xTgAD mice. Intraneuronal Aβ occurred in the tectum, periaqueductal gray, substantia nigra, red nucleus, tegmentum and mesencephalic V nucleus at all ages. Aβ-positive neuron numbers significantly decreased in the superior colliculus and substantia nigra while AT8-positive superior colliculus, red nucleus, principal sensory V, vestibular nuclei, and tegmental neurons significantly increased between 2 and 12 months. Alz50-positive neuron numbers increased only in the inferior colliculus between these ages. Dual labeling revealed a few Aβ- and tau- positive neurons. Plaques occurred only in the pons of female 3xTgAD mice starting at 9 months. 3xTgAD mice provide a platform to define in vivo mechanisms of Aβ and tau brainstem pathology. PMID:19524671

Mapping of the Tuple1 gene to mouse chromosome 16A-B1

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

Mattei, M.G.; Halford, S.; Scambler, P.J.

The human TUPLE1 gene encodes a putative transcriptional regulator and maps to chromosome 22, and therefore may play a role in Di-George syndrome (DGS), relo-cardio-facial syndrome (VCFS), or a related pathology. The murine TUPLE1 gene has also been cloned and shows strong sequence similarity to TUPLE1. Comparative mapping is useful in the study of chromosome evolution and is sometimes able to indicate possible mouse mutations that are potential models of human genetic disorders. As TIPLE1 is a candidate gene for the haploinsufficient phenotype in DGS, we mapped TUPLE1 to mouse chromosome 16A-B1. 6 refs., 1 fig.

Animal models of ocular angiogenesis: from development to pathologies.

PubMed

Liu, Chi-Hsiu; Wang, Zhongxiao; Sun, Ye; Chen, Jing

2017-11-01

Pathological angiogenesis in the eye is an important feature in the pathophysiology of many vision-threatening diseases, including retinopathy of prematurity, diabetic retinopathy, and age-related macular degeneration, as well as corneal diseases with abnormal angiogenesis. Development of reproducible and reliable animal models of ocular angiogenesis has advanced our understanding of both the normal development and the pathobiology of ocular neovascularization. These models have also proven to be valuable experimental tools with which to easily evaluate potential antiangiogenic therapies beyond eye research. This review summarizes the current available animal models of ocular angiogenesis. Models of retinal and choroidal angiogenesis, including oxygen-induced retinopathy, laser-induced choroidal neovascularization, and transgenic mouse models with deficient or spontaneous retinal/choroidal neovascularization, as well as models with induced corneal angiogenesis, are widely used to investigate the molecular and cellular basis of angiogenic mechanisms. Theoretical concepts and experimental protocols of these models are outlined, as well as their advantages and potential limitations, which may help researchers choose the most suitable models for their investigative work.-Liu, C.-H., Wang, Z., Sun, Y., Chen, J. Animal models of ocular angiogenesis: from development to pathologies. © FASEB.

Hemagglutination and graft-versus-host disease in the severe combined immunodeficiency mouse lymphoproliferative disease model.

PubMed Central

Pirruccello, S. J.; Nakamine, H.; Beisel, K. W.; Kleveland, K. L.; Okano, M.; Taguchi, Y.; Davis, J. R.; Mahloch, M. L.; Purtilo, D. T.

1992-01-01

In the course of evaluating the severe combined immunodeficiency mouse-human peripheral blood lymphocyte (SCID-PBL) model of lymphoproliferative disease, we noted hemagglutination occurring in peripheral blood smears of mice with serum human immunoglobulin levels greater than 1.0 mg/ml. The hemagglutinating process was mediated by human anti-mouse red cell antibodies of the IgM class, peaked at five to seven weeks post-transfer of 5 to 7 x 10(7) human PBL and was generally self limiting. However, death resulted in some mice when serum immunoglobulin levels were greater than 3.0 mg/ml. The most severely affected mice had hemagglutination induced congestion of liver, lungs and spleen. Several mice also had lesions consistent with graft-versus-host disease (GVHD) including focal hepatic necrosis and destruction of mouse splenic hematopoietic elements. The lesions associated with hemagglutination and GVHD in SCID-PBL mice are distinct from those associated with EBV-induced lymphoproliferation. Recognition of these pathologic processes are required for a thorough understanding of the SCID-PBL model. Images Figure 1 Figure 3 Figure 4 PMID:1580330

Age-dependent phenotypic characteristics of a triple transgenic mouse model of Alzheimer disease.

PubMed

Pietropaolo, Susanna; Feldon, Joram; Yee, Benjamin K

2008-08-01

The triple-transgenic mouse line (3 x Tg-AD) harboring PS1M146V, APPSwe, and taup301L transgenes represents the only transgenic model for Alzheimer's disease (AD) to date capturing both beta-amyloid and tau neuropathology. The present study provides an extensive behavioral characterization of the 3 x Tg-AD mouse line, evaluating the emergence of noncognitive and cognitive AD-like symptoms at two ages corresponding to the early (6-7 months) and advanced (12-13 months) stages of AD-pathology. Enhanced responsiveness to aversive stimulation was detected in mutant mice at both ages: the 3 x Tg-AD genotype enhanced acoustic startle response and facilitated performance in the cued-version of the water maze. These noncognitive phenotypes were accompanied by hyperactivity and reduced locomotor habituation in the open field at the older age. Signs of cognitive aberrations were also detected at both ages, but they were limited to associative learning. The present study suggests that this popular transgenic mouse model of AD has clear phenotypes beyond the cognitive domain, and their potential relationship to the cognitive phenotypes should be further explored.

Deletion of the Inflammasome Sensor Aim2 Mitigates Aβ Deposition and Microglial Activation but Increases Inflammatory Cytokine Expression in an Alzheimer Disease Mouse Model.

PubMed

Wu, Pei-Jung; Hung, Yun-Fen; Liu, Hsin-Yu; Hsueh, Yi-Ping

2017-01-01

Inflammation is clearly associated with Alzheimer disease (AD). Knockout of Nlrp3, a gene encoding an inflammasome sensor, has been shown to ameliorate AD pathology in a mouse model. Because AIM2 is the most dominant inflammasome sensor expressed in mouse brains, here we investigate whether Aim2 deletion also influences the phenotype of a 5XFAD AD mouse model. Quantitative RT-PCR, immunostaining, immunoblotting, and behavioral analyses were applied to compare wild-type, Aim2-/-, 5XFAD, and Aim2-/-;5XFAD mice. We found that Aim2 knockout mitigates Aβ deposition in the cerebral cortex and hippocampus of 5XFAD mice. The activation of microglial cells is also reduced in Aim2-/-;5XFAD brains compared with 5XFAD brains. However, Aim2 knockout does not improve memory and anxiety phenotypes of 5XFAD mice in an open field, cued Y-maze, or Barnes maze. Compared with 5XFAD mice, Il-1 expression levels are not reduced in Aim2-/-;5XFAD mice. Unexpectedly, Il-6 and Il-18 expression levels in 5XFAD brains were further increased when Aim2 was deleted. Thus, inflammatory cytokine expression in 5XFAD brains is upregulated by Aim2 deletion through an unknown mechanism. Although Aim2 knockout mitigates Aβ deposition and microglial activation, Aim2 deletion does not have a beneficial effect on the spatial memory or cytokine expression of 5XFAD mice. Our findings suggest that Aβ aggregation and microglial activation may not always be correlated with the expression of inflammatory cytokines or cognitive function of 5XFAD mice. Our study also implies that different inflammasomes likely perform distinct roles in different physiological and/or pathological events. © 2017 S. Karger AG, Basel.

R6/2 Huntington's disease mice develop early and progressive abnormal brain metabolism and seizures.

PubMed

Cepeda-Prado, Efrain; Popp, Susanna; Khan, Usman; Stefanov, Dimitre; Rodríguez, Jorge; Menalled, Liliana B; Dow-Edwards, Diana; Small, Scott A; Moreno, Herman

2012-05-09

A hallmark feature of Huntington's disease pathology is the atrophy of brain regions including, but not limited to, the striatum. Though MRI studies have identified structural CNS changes in several Huntington's disease (HD) mouse models, the functional consequences of HD pathology during the progression of the disease have yet to be investigated using in vivo functional MRI (fMRI). To address this issue, we first established the structural and functional MRI phenotype of juvenile HD mouse model R6/2 at early and advanced stages of disease. Significantly higher fMRI signals [relative cerebral blood volumes (rCBVs)] and atrophy were observed in both age groups in specific brain regions. Next, fMRI results were correlated with electrophysiological analysis, which showed abnormal increases in neuronal activity in affected brain regions, thus identifying a mechanism accounting for the abnormal fMRI findings. [(14)C] 2-deoxyglucose maps to investigate patterns of glucose utilization were also generated. An interesting mismatch between increases in rCBV and decreases in glucose uptake was observed. Finally, we evaluated the sensitivity of this mouse line to audiogenic seizures early in the disease course. We found that R6/2 mice had an increased susceptibility to develop seizures. Together, these findings identified seizure activity in R6/2 mice and show that neuroimaging measures sensitive to oxygen metabolism can be used as in vivo biomarkers, preceding the onset of an overt behavioral phenotype. Since fMRI-rCBV can also be obtained in patients, we propose that it may serve as a translational tool to evaluate therapeutic responses in humans and HD mouse models.

Protective and therapeutic role of 2-carba-cyclic phosphatidic acid in demyelinating disease.

PubMed

Yamamoto, Shinji; Yamashina, Kota; Ishikawa, Masaki; Gotoh, Mari; Yagishita, Sosuke; Iwasa, Kensuke; Maruyama, Kei; Murakami-Murofushi, Kimiko; Yoshikawa, Keisuke

2017-07-21

Multiple sclerosis is a neuroinflammatory demyelinating and neurodegenerative disease of the central nervous system characterized by recurrent and progressive demyelination/remyelination cycles, neuroinflammation, oligodendrocyte loss, demyelination, and axonal degeneration. Cyclic phosphatidic acid (cPA) is a natural phospholipid mediator with a unique cyclic phosphate ring structure at the sn-2 and sn-3 positions of the glycerol backbone. We reported earlier that cPA elicits a neurotrophin-like action and protects hippocampal neurons from ischemia-induced delayed neuronal death. We designed, chemically synthesized, and metabolically stabilized derivatives of cPA: 2-carba-cPA (2ccPA), a synthesized compound in which one of the phosphate oxygen molecules is replaced with a methylene group at the sn-2 position. In the present study, we investigated whether 2ccPA exerts protective effects in oligodendrocytes and suppresses pathology in the two most common mouse models of multiple sclerosis. To evaluate whether 2ccPA has potential beneficial effects on the pathology of multiple sclerosis, we investigated the effects of 2ccPA on oligodendrocyte cell death in vitro and administrated 2ccPA to mouse models of experimental autoimmune encephalomyelitis (EAE) and cuprizone-induced demyelination. We demonstrated that 2ccPA suppressed the CoCl 2 -induced increase in the Bax/Bcl-2 protein expression ratio and phosphorylation levels of p38MAPK and JNK protein. 2ccPA treatment reduced cuprizone-induced demyelination, microglial activation, NLRP3 inflammasome, and motor dysfunction. Furthermore, 2ccPA treatment reduced autoreactive T cells and macrophages, spinal cord injury, and pathological scores in EAE, the autoimmune multiple sclerosis mouse model. We demonstrated that 2ccPA protected oligodendrocytes via suppression of the mitochondrial apoptosis pathway. Also, we found beneficial effects of 2ccPA in the multiperiod of cuprizone-induced demyelination and the pathology of EAE. These data indicate that 2ccPA may be a promising compound for the development of new drugs to treat demyelinating disease and ameliorate the symptoms of multiple sclerosis.

Better Utilization of Mouse Models of Neurodegenerative Diseases in Preclinical Studies: From the Bench to the Clinic.

PubMed

Janus, Christopher; Hernandez, Carolina; deLelys, Victoria; Roder, Hanno; Welzl, Hans

2016-01-01

The major symptom of Alzheimer's disease is dementia progressing with age. Its clinical diagnosis is preceded by a long prodromal period of brain pathology that encompasses both formation of extracellular amyloid and intraneuronal tau deposits in the brain and widespread neuronal death. At present, familial cases of dementia provide the most promising foundation for modeling neurodegenerative tauopathies, a group of heterogeneous disorders characterized by prominent intracellular accumulation of hyperphosphorylated tau protein. In this chapter, we describe major behavioral hallmarks of tauopathies, briefly outline the genetics underlying familial cases, and discuss the arising implications for modeling the disease in transgenic mouse systems. The selection of tests performed to evaluate the phenotype of a model should be guided by the key behavioral hallmarks that characterize human disorder and their homology to mouse cognitive systems. We attempt to provide general guidelines and establish criteria for modeling dementia in a mouse; however, interpretations of obtained results should avoid a reductionist "one gene, one disease" explanation of model characteristics. Rather, the focus should be directed to the question of how the mouse genome can cope with the over-expression of the protein coded by transgene(s). While each model is valuable within its own constraints and the experiments performed are guided by specific hypotheses, we seek to expand upon their methodology by offering guidance spanning from issues of mouse husbandry to choices of behavioral tests and routes of drug administration that might increase the external validity of studies and consequently optimize the translational aspect of preclinical research.

Quantifying the vascular response to ischemia with speckle variance optical coherence tomography

PubMed Central

Poole, Kristin M.; McCormack, Devin R.; Patil, Chetan A.; Duvall, Craig L.; Skala, Melissa C.

2014-01-01

Longitudinal monitoring techniques for preclinical models of vascular remodeling are critical to the development of new therapies for pathological conditions such as ischemia and cancer. In models of skeletal muscle ischemia in particular, there is a lack of quantitative, non-invasive and long term assessment of vessel morphology. Here, we have applied speckle variance optical coherence tomography (OCT) methods to quantitatively assess vascular remodeling and growth in a mouse model of peripheral arterial disease. This approach was validated on two different mouse strains known to have disparate rates and abilities of recovering following induction of hind limb ischemia. These results establish the potential for speckle variance OCT as a tool for quantitative, preclinical screening of pro- and anti-angiogenic therapies. PMID:25574425

Anatomical Variation of the Tarsus in Common Inbred Mouse Strains.

PubMed

Richbourg, Heather A; Martin, Matthew J; Schachner, Emma R; McNulty, Margaret A

2017-03-01

Rodent models are used for a variety of orthopedic research applications; however, anatomy references include mostly artistic representations. Advanced imaging techniques, including micro-computed tomography (microCT), can provide more accurate representations of subtle anatomical characteristics. A recent microCT atlas of laboratory mouse (Mus musculus) anatomy depicts the central and tarsal bone III (T3) as a single bone, differing from previous references. Fusion of tarsal bones is generally characterized as pathological secondary to mutations associated with growth factors, and normal variation has not been documented in the mouse tarsus. Therefore, it is unclear if this fusion is a normal or a pathological characteristic. The aim of this study is to characterize the tarsus of the laboratory mouse and compare it to the rat and selected outgroup species (i.e., white-footed mouse) via microCT and histology to determine if the central and T3 are separate or fused into a single bone. Laboratory mice (C57/Bl6 [n = 17] and BalbC [n = 2]) and rats (n = 5) were scanned with microCT. A representative laboratory mouse from each strain was evaluated histologically via serial sagittal sections through the mid-tarsus. General pedal anatomy was similar between all species; however, the central and T3 bones were fused in all laboratory mice but not the rat or white-footed mouse. A band of hyaline cartilage was identified within the fused bone of the laboratory mice. We conclude that the fusion found is a normal characteristic in laboratory mice, but timing of the fusion remains ambiguous. Anat Rec, 300:450-459, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Unbiased Proteomics of Early Lewy Body Formation Model Implicates Active Microtubule Affinity-Regulating Kinases (MARKs) in Synucleinopathies

PubMed Central

Riddle, Dawn M.; Zhang, Bin

2017-01-01

Parkinson's disease (PD) patients progressively accumulate intracytoplasmic inclusions formed by misfolded α-synuclein known as Lewy bodies (LBs). LBs also contain other proteins that may or may not be relevant in the disease process. To identify proteins involved early in LB formation, we performed proteomic analysis of insoluble proteins in a primary neuron culture model of α-synuclein pathology. We identified proteins previously found in authentic LBs in PD as well as several novel proteins, including the microtubule affinity-regulating kinase 1 (MARK1), one of the most enriched proteins in this model of LB formation. Activated MARK proteins (MARKs) accumulated in LB-like inclusions in this cell-based model as well as in a mouse model of LB disease and in LBs of postmortem synucleinopathy brains. Inhibition of MARKs dramatically exacerbated α-synuclein pathology. These findings implicate MARKs early in synucleinopathy pathogenesis and as potential therapeutic drug targets. SIGNIFICANCE STATEMENT Neurodegenerative diseases are diagnosed definitively only in postmortem brains by the presence of key misfolded and aggregated disease proteins, but cellular processes leading to accumulation of these proteins have not been well elucidated. Parkinson's disease (PD) patients accumulate misfolded α-synuclein in LBs, the diagnostic signatures of PD. Here, unbiased mass spectrometry was used to identify the microtubule affinity-regulating kinase family (MARKs) as activated and insoluble in a neuronal culture PD model. Aberrant activation of MARKs was also found in a PD mouse model and in postmortem PD brains. Further, inhibition of MARKs led to increased pathological α-synuclein burden. We conclude that MARKs play a role in PD pathogenesis. PMID:28522732

Development of (99m)Tc-Labeled Pyridyl Benzofuran Derivatives To Detect Pancreatic Amylin in Islet Amyloid Model Mice.

PubMed

Yoshimura, Masashi; Ono, Masahiro; Watanabe, Hiroyuki; Kimura, Hiroyuki; Saji, Hideo

2016-06-15

While islet amyloid deposition comprising amylin is one of pathological hallmarks of type 2 diabetes mellitus (T2DM), no useful amylin-imaging probe has been reported. In this study, we evaluated two (99m)Tc-labeled pyridyl benzofuran derivatives as novel amylin-imaging probes using the newly established islet amyloid model mouse. Binding experiments in vitro demonstrated that [(99m)Tc]1 displayed a higher affinity for amylin aggregates than [(99m)Tc]2. Autoradiographic studies using human pancreas sections with T2DM revealed that [(99m)Tc]1 clearly labeled islet amyloid in T2DM pancreatic sections, while [(99m)Tc]2 did not. Although the initial uptake of [(99m)Tc]1 by the normal mouse pancreas was low (0.74%ID/g at 2 min post-injection), [(99m)Tc]1 showed higher retention in the model mouse pancreas than that of the normal mouse, and exhibited strong binding to amylin aggregates in the living pancreas of the model mice. These results suggest that [(99m)Tc]1 is a potential imaging probe targeting islet amyloids in the T2DM pancreas.

Reactive microglia drive tau pathology and contribute to the spreading of pathological tau in the brain

PubMed Central

Maphis, Nicole; Xu, Guixiang; Kokiko-Cochran, Olga N.; Jiang, Shanya; Cardona, Astrid; Ransohoff, Richard M.; Lamb, Bruce T.

2015-01-01

Pathological aggregation of tau is a hallmark of Alzheimer’s disease and related tauopathies. We have previously shown that the deficiency of the microglial fractalkine receptor (CX3CR1) led to the acceleration of tau pathology and memory impairment in an hTau mouse model of tauopathy. Here, we show that microglia drive tau pathology in a cell-autonomous manner. First, tau hyperphosphorylation and aggregation occur as early as 2 months of age in hTauCx3cr1−/− mice. Second, CD45+ microglial activation correlates with the spatial memory deficit and spread of tau pathology in the anatomically connected regions of the hippocampus. Third, adoptive transfer of purified microglia derived from hTauCx3cr1−/− mice induces tau hyperphosphorylation within the brains of non-transgenic recipient mice. Finally, inclusion of interleukin 1 receptor antagonist (Kineret®) in the adoptive transfer inoculum significantly reduces microglia-induced tau pathology. Together, our results suggest that reactive microglia are sufficient to drive tau pathology and correlate with the spread of pathological tau in the brain. PMID:25833819

Generation of a pancreatic cancer model using a Pdx1-Flp recombinase knock-in allele

PubMed Central

Wu, Jinghai; Liu, Xin; Nayak, Sunayana G.; Pitarresi, Jason R.; Cuitiño, Maria C.; Yu, Lianbo; Hildreth, Blake E.; Thies, Katie A.; Schilling, Daniel J.; Fernandez, Soledad A.; Leone, Gustavo

2017-01-01

The contribution of the tumor microenvironment to the development of pancreatic adenocarcinoma (PDAC) is unclear. The LSL-KrasG12D/+;LSL-p53R172H/+;Pdx-1-Cre (KPC) tumor model, which is widely utilized to faithfully recapitulate human pancreatic cancer, depends on Cre-mediated recombination in the epithelial lineage to drive tumorigenesis. Therefore, specific Cre-loxP recombination in stromal cells cannot be applied in this model, limiting the in vivo investigation of stromal genetics in tumor initiation and progression. To address this issue, we generated a new Pdx1FlpO knock-in mouse line, which represents the first mouse model to physiologically express FlpO recombinase in pancreatic epithelial cells. This mouse specifically recombines Frt loci in pancreatic epithelial cells, including acinar, ductal, and islet cells. When combined with the Frt-STOP-Frt KrasG12D and p53Frt mouse lines, simultaneous Pdx1FlpO activation of mutant Kras and deletion of p53 results in the spectrum of pathologic changes seen in PDAC, including PanIN lesions and ductal carcinoma. Combination of this KPF mouse model with any stroma-specific Cre can be used to conditionally modify target genes of interest. This will provide an excellent in vivo tool to study the roles of genes in different cell types and multiple cell compartments within the pancreatic tumor microenvironment. PMID:28934293

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.

Spatial variability in T-tubule and electrical remodeling of left ventricular epicardium in mouse hearts with transgenic Gαq overexpression-induced pathological hypertrophy

PubMed Central

Tao, Wen; Shi, Jianjian; Dorn, Gerald W.; Wei, Lei; Rubart, Michael

2012-01-01

Pathological left ventricular hypertrophy (LVH) is consistently associated with prolongation of the ventricular action potentials. A number of previous studies, employing various experimental models of hypertrophy, have revealed marked differences in the effects of hypertrophy on action potential duration (APD) between myocytes from endocardial and epicardial layers of the LV free wall. It is not known, however, whether pathological LVH is also accompanied by redistribution of APD among myocytes from the same layer in the LV free wall. In the experiments here, LV epicardial action potential remodeling was examined in a mouse model of decompensated LVH, produced by cardiac-restricted transgenic Gαq overexpression. Confocal linescanning-based optical recordings of propagated action potentials from individual in situ cardiomyocytes across the outer layer of the anterior LV epicardium demonstrated spatially non-uniform action potential prolongation in transgenic hearts, giving rise to alterations in spatial dispersion of epicardial repolarization. Local density and distribution of anti-Cx43 mmune reactivity in Gαq hearts were unchanged compared to wild-type hearts, suggesting preservation of intercellular coupling. Confocal microscopy also revealed heterogeneous disorganization of T-tubules in epicardial cardiomyocytes in situ. These data provide evidence of the existence of significant electrical and structural heterogeneity within the LV epicardial layer of hearts with transgenic Gαq overexpression-induced hypertrophy, and further support the notion that a small portion of electrically well connected LV tissue can maintain dispersion of action potential duration through heterogeneity in the activities of sarcolemmal ionic currents that control repolarization. It remains to be examined whether other experimental models of pathological LVH, including pressure overload LVH, similarly exhibit alterations in T-tubule organization and/or dispersion of repolarization within distinct layers of LV myocardium. PMID:22728217

Silencing neuronal mutant androgen receptor in a mouse model of spinal and bulbar muscular atrophy.

PubMed

Sahashi, Kentaro; Katsuno, Masahisa; Hung, Gene; Adachi, Hiroaki; Kondo, Naohide; Nakatsuji, Hideaki; Tohnai, Genki; Iida, Madoka; Bennett, C Frank; Sobue, Gen

2015-11-01

Spinal and bulbar muscular atrophy (SBMA), an adult-onset neurodegenerative disease that affects males, results from a CAG triplet repeat/polyglutamine expansions in the androgen receptor (AR) gene. Patients develop progressive muscular weakness and atrophy, and no effective therapy is currently available. The tissue-specific pathogenesis, especially relative pathological contributions between degenerative motor neurons and muscles, remains inconclusive. Though peripheral pathology in skeletal muscle caused by toxic AR protein has been recently reported to play a pivotal role in the pathogenesis of SBMA using mouse models, the role of motor neuron degeneration in SBMA has not been rigorously investigated. Here, we exploited synthetic antisense oligonucleotides to inhibit the RNA levels of mutant AR in the central nervous system (CNS) and explore its therapeutic effects in our SBMA mouse model that harbors a mutant AR gene with 97 CAG expansions and characteristic SBMA-like neurogenic phenotypes. A single intracerebroventricular administration of the antisense oligonucleotides in the presymptomatic phase efficiently suppressed the mutant gene expression in the CNS, and delayed the onset and progression of motor dysfunction, improved body weight gain and survival with the amelioration of neuronal histopathology in motor units such as spinal motor neurons, neuromuscular junctions and skeletal muscle. These findings highlight the importance of the neurotoxicity of mutant AR protein in motor neurons as a therapeutic target. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Experimental hypertension increases spontaneous intracerebral hemorrhages in a mouse model of cerebral amyloidosis

PubMed Central

Passos, Giselle F; Kilday, Kelley; Gillen, Daniel L; Vasilevko, Vitaly

2015-01-01

Hypertension and cerebral amyloid angiopathy (CAA) are major risk factors for intracerebral hemorrhage (ICH); however the mechanisms of interplay between the two are not fully understood. We investigated the effect of hypertension in a transgenic mouse model with Alzheimer’s-like pathology (Tg2576) treating them with angiontensin II and L-NG-nitroarginine methyl ester. A similar increase in systolic blood pressure was observed in both Tg2576 and control mice; however Tg2576 mice developed signs of stroke with a markedly shorter latency. Cerebral deposition of amyloid beta promotes the hypertension-induced ICH, thus supporting the notion that hypertension is a risk factor for ICH among patients with CAA. PMID:26661173

Abeta42-driven cerebral amyloidosis in transgenic mice reveals early and robust pathology.

PubMed

Radde, Rebecca; Bolmont, Tristan; Kaeser, Stephan A; Coomaraswamy, Janaky; Lindau, Dennis; Stoltze, Lars; Calhoun, Michael E; Jäggi, Fabienne; Wolburg, Hartwig; Gengler, Simon; Haass, Christian; Ghetti, Bernardino; Czech, Christian; Hölscher, Christian; Mathews, Paul M; Jucker, Mathias

2006-09-01

We have generated a novel transgenic mouse model on a C57BL/6J genetic background that coexpresses KM670/671NL mutated amyloid precursor protein and L166P mutated presenilin 1 under the control of a neuron-specific Thy1 promoter element (APPPS1 mice). Cerebral amyloidosis starts at 6-8 weeks and the ratio of human amyloid (A)beta42 to Abeta40 is 1.5 and 5 in pre-depositing and amyloid-depositing mice, respectively. Consistent with this ratio, extensive congophilic parenchymal amyloid but minimal amyloid angiopathy is observed. Amyloid-associated pathologies include dystrophic synaptic boutons, hyperphosphorylated tau-positive neuritic structures and robust gliosis, with neocortical microglia number increasing threefold from 1 to 8 months of age. Global neocortical neuron loss is not apparent up to 8 months of age, but local neuron loss in the dentate gyrus is observed. Because of the early onset of amyloid lesions, the defined genetic background of the model and the facile breeding characteristics, APPPS1 mice are well suited for studying therapeutic strategies and the pathomechanism of amyloidosis by cross-breeding to other genetically engineered mouse models.

Aβ42-driven cerebral amyloidosis in transgenic mice reveals early and robust pathology

PubMed Central

Radde, Rebecca; Bolmont, Tristan; Kaeser, Stephan A; Coomaraswamy, Janaky; Lindau, Dennis; Stoltze, Lars; Calhoun, Michael E; Jäggi, Fabienne; Wolburg, Hartwig; Gengler, Simon; Haass, Christian; Ghetti, Bernardino; Czech, Christian; Hölscher, Christian; Mathews, Paul M; Jucker, Mathias

2006-01-01

We have generated a novel transgenic mouse model on a C57BL/6J genetic background that coexpresses KM670/671NL mutated amyloid precursor protein and L166P mutated presenilin 1 under the control of a neuron-specific Thy1 promoter element (APPPS1 mice). Cerebral amyloidosis starts at 6–8 weeks and the ratio of human amyloid (A)β42 to Aβ40 is 1.5 and 5 in pre-depositing and amyloid-depositing mice, respectively. Consistent with this ratio, extensive congophilic parenchymal amyloid but minimal amyloid angiopathy is observed. Amyloid-associated pathologies include dystrophic synaptic boutons, hyperphosphorylated tau-positive neuritic structures and robust gliosis, with neocortical microglia number increasing threefold from 1 to 8 months of age. Global neocortical neuron loss is not apparent up to 8 months of age, but local neuron loss in the dentate gyrus is observed. Because of the early onset of amyloid lesions, the defined genetic background of the model and the facile breeding characteristics, APPPS1 mice are well suited for studying therapeutic strategies and the pathomechanism of amyloidosis by cross-breeding to other genetically engineered mouse models. PMID:16906128

Neuropathogenicity of Two Saffold Virus Type 3 Isolates in Mouse Models

PubMed Central

Kotani, Osamu; Naeem, Asif; Suzuki, Tadaki; Iwata-Yoshikawa, Naoko; Sato, Yuko; Nakajima, Noriko; Hosomi, Takushi; Tsukagoshi, Hiroyuki; Kozawa, Kunihisa; Hasegawa, Hideki; Taguchi, Fumihiro; Shimizu, Hiroyuki; Nagata, Noriyo

2016-01-01

Objective Saffold virus (SAFV), a picornavirus, is occasionally detected in children with acute flaccid paralysis, meningitis, and cerebellitis; however, the neuropathogenicity of SAFV remains undetermined. Methods The virulence of two clinical isolates of SAFV type 3 (SAFV-3) obtained from a patient with aseptic meningitis (AM strain) and acute upper respiratory inflammation (UR strain) was analyzed in neonatal and young mice utilizing virological, pathological, and immunological methods. Results The polyproteins of the strains differed in eight amino acids. Both clinical isolates were infective, exhibited neurotropism, and were mildly neurovirulent in neonatal ddY mice. Both strains pathologically infected neural progenitor cells and glial cells, but not large neurons, with the UR strain also infecting epithelial cells. UR infection resulted in longer inflammation in the brain and spinal cord because of demyelination, while the AM strain showed more infectivity in the cerebellum in neonatal ddY mice. Additionally, young BALB/c mice seroconverted following mucosal inoculation with the UR, but not the AM, strain. Conclusions Both SAFV-3 isolates had neurotropism and mild neurovirulence but showed different cell tropisms in both neonatal and young mouse models. This animal model has the potential to recapitulate the potential neuropathogenicity of SAFV-3. PMID:26828718

Behavioral Analysis and Rescue of a Novel Cerebellar Mouse Model of Tuberous Sclerosis Complex

DTIC Science & Technology

2012-05-01

and Silva; Lee et al.; Marui et al., 2004). Therefore, dysregulation of mTORC1 appears to be an important pathway leading to the autistic-phenotype...for understanding the role of cerebellar pathology in autism. Eur J Neurosci. 31, 544-55. Marui , T., et al., 2004. Association between the

Genome Wide Identification of SARS-CoV Susceptibility Loci Using the Collaborative Cross

PubMed Central

Gralinski, Lisa E.; Ferris, Martin T.; Aylor, David L.; Whitmore, Alan C.; Green, Richard; Frieman, Matthew B.; Deming, Damon; Menachery, Vineet D.; Miller, Darla R.; Buus, Ryan J.; Bell, Timothy A.; Churchill, Gary A.; Threadgill, David W.; Katze, Michael G.; McMillan, Leonard; Valdar, William; Heise, Mark T.; Pardo-Manuel de Villena, Fernando; Baric, Ralph S.

2015-01-01

New systems genetics approaches are needed to rapidly identify host genes and genetic networks that regulate complex disease outcomes. Using genetically diverse animals from incipient lines of the Collaborative Cross mouse panel, we demonstrate a greatly expanded range of phenotypes relative to classical mouse models of SARS-CoV infection including lung pathology, weight loss and viral titer. Genetic mapping revealed several loci contributing to differential disease responses, including an 8.5Mb locus associated with vascular cuffing on chromosome 3 that contained 23 genes and 13 noncoding RNAs. Integrating phenotypic and genetic data narrowed this region to a single gene, Trim55, an E3 ubiquitin ligase with a role in muscle fiber maintenance. Lung pathology and transcriptomic data from mice genetically deficient in Trim55 were used to validate its role in SARS-CoV-induced vascular cuffing and inflammation. These data establish the Collaborative Cross platform as a powerful genetic resource for uncovering genetic contributions of complex traits in microbial disease severity, inflammation and virus replication in models of outbred populations. PMID:26452100

Modulation of Tau Isoforms Imbalance Precludes Tau Pathology and Cognitive Decline in a Mouse Model of Tauopathy.

PubMed

Espíndola, Sonia Lorena; Damianich, Ana; Alvarez, Rodrigo Javier; Sartor, Manuela; Belforte, Juan Emilio; Ferrario, Juan Esteban; Gallo, Jean-Marc; Avale, María Elena

2018-04-17

The microtubule-associated protein tau regulates myriad neuronal functions, such as microtubule dynamics, axonal transport and neurite outgrowth. Tauopathies are neurodegenerative disorders characterized by the abnormal metabolism of tau, which accumulates as insoluble neuronal deposits. The adult human brain contains equal amounts of tau isoforms with three (3R) or four (4R) repeats of microtubule-binding domains, derived from the alternative splicing of exon 10 (E10) in the tau transcript. Several tauopathies are associated with imbalances of tau isoforms, due to splicing deficits. Here, we used a trans-splicing strategy to shift the inclusion of E10 in a mouse model of tauopathy that produces abnormal excess of 3R tau. Modulating the 3R/4R ratio in the prefrontal cortex led to a significant reduction of pathological tau accumulation concomitant with improvement of neuronal firing and reduction of cognitive impairments. Our results suggest promising potential for the use of RNA reprogramming in human neurodegenerative diseases. Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.

An entirely automated method to score DSS-induced colitis in mice by digital image analysis of pathology slides

PubMed Central

Kozlowski, Cleopatra; Jeet, Surinder; Beyer, Joseph; Guerrero, Steve; Lesch, Justin; Wang, Xiaoting; DeVoss, Jason; Diehl, Lauri

2013-01-01

SUMMARY The DSS (dextran sulfate sodium) model of colitis is a mouse model of inflammatory bowel disease. Microscopic symptoms include loss of crypt cells from the gut lining and infiltration of inflammatory cells into the colon. An experienced pathologist requires several hours per study to score histological changes in selected regions of the mouse gut. In order to increase the efficiency of scoring, Definiens Developer software was used to devise an entirely automated method to quantify histological changes in the whole H&E slide. When the algorithm was applied to slides from historical drug-discovery studies, automated scores classified 88% of drug candidates in the same way as pathologists’ scores. In addition, another automated image analysis method was developed to quantify colon-infiltrating macrophages, neutrophils, B cells and T cells in immunohistochemical stains of serial sections of the H&E slides. The timing of neutrophil and macrophage infiltration had the highest correlation to pathological changes, whereas T and B cell infiltration occurred later. Thus, automated image analysis enables quantitative comparisons between tissue morphology changes and cell-infiltration dynamics. PMID:23580198

The effect of progressive hearing loss on the morphology of endbulbs of Held and bushy cells.

PubMed

Connelly, Catherine J; Ryugo, David K; Muniak, Michael A

2017-01-01

Studies of congenital and early-onset deafness have demonstrated that an absence of peripheral sound-evoked activity in the auditory nerve causes pathological changes in central auditory structures. The aim of this study was to establish whether progressive acquired hearing loss could lead to similar brain changes that would degrade the precision of signal transmission. We used complementary physiologic hearing tests and microscopic techniques to study the combined effect of both magnitude and duration of hearing loss on one of the first auditory synapses in the brain, the endbulb of Held (EB), along with its bushy cell (BC) target in the anteroventral cochlear nucleus. We compared two hearing mouse strains (CBA/Ca and heterozygous shaker-2 +/- ) against a model of early-onset progressive hearing loss (DBA/2) and a model of congenital deafness (homozygous shaker-2 -/- ), examining each strain at 1, 3, and 6 months of age. Furthermore, we employed a frequency model of the mouse cochlear nucleus to constrain our analyses to regions most likely to exhibit graded changes in hearing function with time. No significant differences in the gross morphology of EB or BC structure were observed in 1-month-old animals, indicating uninterrupted development. However, in animals with hearing loss, both EBs and BCs exhibited a graded reduction in size that paralleled the hearing loss, with the most severe pathology seen in deaf 6-month-old shaker-2 -/- mice. Ultrastructural pathologies associated with hearing loss were less dramatic: minor changes were observed in terminal size but mitochondrial fraction and postsynaptic densities remained relatively stable. These results indicate that acquired progressive hearing loss can have consequences on auditory brain structure, with prolonged loss leading to greater pathologies. Our findings suggest a role for early intervention with assistive devices in order to mitigate long-term pathology and loss of function. Copyright © 2016 Elsevier B.V. All rights reserved.

Cyclin D2 is a critical mediator of exercise-induced cardiac hypertrophy.

PubMed

Luckey, Stephen W; Haines, Chris D; Konhilas, John P; Luczak, Elizabeth D; Messmer-Kratzsch, Antke; Leinwand, Leslie A

2017-12-01

A number of signaling pathways underlying pathological cardiac hypertrophy have been identified. However, few studies have probed the functional significance of these signaling pathways in the context of exercise or physiological pathways. Exercise studies were performed on females from six different genetic mouse models that have been shown to exhibit alterations in pathological cardiac adaptation and hypertrophy. These include mice expressing constitutively active glycogen synthase kinase-3β (GSK-3βS9A), an inhibitor of CaMK II (AC3-I), both GSK-3βS9A and AC3-I (GSK-3βS9A/AC3-I), constitutively active Akt (myrAkt), mice deficient in MAPK/ERK kinase kinase-1 (MEKK1 -/- ), and mice deficient in cyclin D2 (cyclin D2 -/- ). Voluntary wheel running performance was similar to NTG littermates for five of the mouse lines. Exercise induced significant cardiac growth in all mouse models except the cyclin D2 -/- mice. Cardiac function was not impacted in the cyclin D2 -/- mice and studies using a phospho-antibody array identified six proteins with increased phosphorylation (greater than 150%) and nine proteins with decreased phosphorylation (greater than 33% decrease) in the hearts of exercised cyclin D2 -/- mice compared to exercised NTG littermate controls. Our results demonstrate that unlike the other hypertrophic signaling molecules tested here, cyclin D2 is an important regulator of both pathologic and physiological hypertrophy. Impact statement This research is relevant as the hypertrophic signaling pathways tested here have only been characterized for their role in pathological hypertrophy, and not in the context of exercise or physiological hypertrophy. By using the same transgenic mouse lines utilized in previous studies, our findings provide a novel and important understanding for the role of these signaling pathways in physiological hypertrophy. We found that alterations in the signaling pathways tested here had no impact on exercise performance. Exercise induced cardiac growth in all of the transgenic mice except for the mice deficient in cyclin D2. In the cyclin D2 null mice, cardiac function was not impacted even though the hypertrophic response was blunted and a number of signaling pathways are differentially regulated by exercise. These data provide the field with an understanding that cyclin D2 is a key mediator of physiological hypertrophy.

Towards developing standard operating procedures for pre-clinical testing in the mdx mouse model of Duchenne muscular dystrophy

PubMed Central

Grounds, Miranda D.; Radley, Hannah G.; Lynch, Gordon S.; Nagaraju, Kanneboyina; De Luca, Annamaria

2008-01-01

This review discusses various issues to consider when developing standard operating procedures for pre-clinical studies in the mdx mouse model of Duchenne muscular dystrophy (DMD). The review describes and evaluates a wide range of techniques used to measure parameters of muscle pathology in mdx mice and identifies some basic techniques that might comprise standardised approaches for evaluation. While the central aim is to provide a basis for the development of standardised procedures to evaluate efficacy of a drug or a therapeutic strategy, a further aim is to gain insight into pathophysiological mechanisms in order to identify other therapeutic targets. The desired outcome is to enable easier and more rigorous comparison of pre-clinical data from different laboratories around the world, in order to accelerate identification of the best pre-clinical therapies in the mdx mouse that will fast-track translation into effective clinical treatments for DMD. PMID:18499465

Developmental abnormalities and age-related neurodegeneration in a mouse model of Down syndrome

PubMed Central

Holtzman, David M.; Santucci, Daniela; Kilbridge, Joshua; Chua-Couzens, Jane; Fontana, David J.; Daniels, Scott E.; Johnson, Randolph M.; Chen, Karen; Sun, Yuling; Carlson, Elaine; Alleva, Enrico; Epstein, Charles J.; Mobley, William C.

1996-01-01

To study the pathogenesis of central nervous system abnormalities in Down syndrome (DS), we have analyzed a new genetic model of DS, the partial trisomy 16 (Ts65Dn) mouse. Ts65Dn mice have an extra copy of the distal aspect of mouse chromosome 16, a segment homologous to human chromosome 21 that contains much of the genetic material responsible for the DS phenotype. Ts65Dn mice show developmental delay during the postnatal period as well as abnormal behaviors in both young and adult animals that may be analogous to mental retardation. Though the Ts65Dn brain is normal on gross examination, there is age-related degeneration of septohippocampal cholinergic neurons and astrocytic hypertrophy, markers of the Alzheimer disease pathology that is present in elderly DS individuals. These findings suggest that Ts65Dn mice may be used to study certain developmental and degenerative abnormalities in the DS brain. PMID:8917591

Cutaneous Surgical Denervation: A Method for Testing the Requirement for Nerves in Mouse Models of Skin Disease.

PubMed

Peterson, Shelby C; Brownell, Isaac; Wong, Sunny Y

2016-06-26

Cutaneous somatosensory nerves function to detect diverse stimuli that act upon the skin. In addition to their established sensory roles, recent studies have suggested that nerves may also modulate skin disorders including atopic dermatitis, psoriasis and cancer. Here, we describe protocols for testing the requirement for nerves in maintaining a cutaneous mechanosensory organ, the touch dome (TD). Specifically, we discuss methods for genetically labeling, harvesting and visualizing TDs by whole-mount staining, and for performing unilateral surgical denervation on mouse dorsal back skin. Together, these approaches can be used to directly compare TD morphology and gene expression in denervated as well as sham-operated skin from the same animal. These methods can also be readily adapted to examine the requirement for nerves in mouse models of skin pathology. Finally, the ability to repeatedly sample the skin provides an opportunity to monitor disease progression at different stages and times after initiation.

Ubiquitin-Positive Intranuclear Inclusions in Neuronal and Glial Cells in a Mouse Model of the Fragile-X Premutation

PubMed Central

Wenzel, H. Jürgen; Hunsaker, Michael R.; Greco, Claudia M.; Willemsen, Rob; Berman, Robert F.

2010-01-01

Fragile X-associated tremor/ataxia syndrome (FXTAS) is an adult-onset neurodegenerative disorder caused by CGG trinucleotide repeat expansions in the fragile X mental retardation 1 (FMR1) gene. The neuropathological hallmark of the disease is the presence of ubiquitin-positive intranuclear inclusions in neurons and in astrocytes. Ubiquitin-positive intranuclear inclusions have also been found in the neurons of transgenic mice model carrying an expanded CGG(98) trinucleotide repeat of human origin, but have not previously been described in glial cells. Therefore, we used immunocytochemical methods to determine the pathological features of nuclear and/or cytoplasmic inclusions in astrocytes, Bergmann glia and neurons, as well as relationships between inclusion patterns, age, and repeat length in CGG knock-in (KI) mice in comparison with wild type mice. In CGG KI mice, ubiquitin-positive intranuclear inclusions were found in neurons (e.g., pyramidal cells, GABAergic neurons) throughout the brain in cortical and subcortical brain regions; these inclusions increased in number and size with advanced age. Ubiquitin-positive intranuclear inclusions were also present in protoplasmic astrocytes, including Bergmann glia in the cerebellum. The morphology of intranuclear inclusions in CGG KI mice was compared to that of typical inclusions in human neurons and astrocytes in postmortem FXTAS brain tissue. This new finding of previously unreported pathology in astrocytes of CGG KI mice now provides an important mouse model to study astrocyte pathology in human FXTAS. PMID:20051238

The replication of a mouse adapted SARS-CoV in a mouse cell line stably expressing the murine SARS-CoV receptor mACE2 efficiently induces the expression of proinflammatory cytokines

PubMed Central

Regla-Nava, Jose A.; Jimenez-Guardeño, Jose M.; Nieto-Torres, Jose L.; Gallagher, Thomas M.; Enjuanes, Luis; DeDiego, Marta L.

2013-01-01

Infection of conventional mice with a mouse adapted (MA15) severe acute respiratory syndrome (SARS) coronavirus (CoV) reproduces many aspects of human SARS such as pathological changes in lung, viremia, neutrophilia, and lethality. However, established mouse cell lines highly susceptible to mouse-adapted SARS-CoV infection are not available. In this work, efficiently transfectable mouse cell lines stably expressing the murine SARS-CoV receptor angiotensin converting enzyme 2 (ACE2) have been generated. These cells yielded high SARS-CoV-MA15 titers and also served as excellent tools for plaque assays. In addition, in these cell lines, SARS-CoV-MA15 induced the expression of proinflammatory cytokines and IFN-β, mimicking what has been observed in experimental animal models infected with SARS-CoV and SARS patients. These cell lines are valuable tools to perform in vitro studies in a mouse cell system that reflects the species used for in vivo studies of SARS-CoV-MA15 pathogenesis. PMID:23911968

Passive Immunization with Anti-Tau Antibodies in Two Transgenic Models

PubMed Central

Chai, Xiyun; Wu, Su; Murray, Tracey K.; Kinley, Robert; Cella, Claire V.; Sims, Helen; Buckner, Nicola; Hanmer, Jenna; Davies, Peter; O'Neill, Michael J.; Hutton, Michael L.; Citron, Martin

2011-01-01

The microtubule-associated protein Tau plays a critical role in the pathogenesis of Alzheimer disease and several related disorders (tauopathies). In the disease Tau aggregates and becomes hyperphosphorylated forming paired helical and straight filaments, which can further condense into higher order neurofibrillary tangles in neurons. The development of this pathology is consistently associated with progressive neuronal loss and cognitive decline. The identification of tractable therapeutic targets in this pathway has been challenging, and consequently very few clinical studies addressing Tau pathology are underway. Recent active immunization studies have raised the possibility of modulating Tau pathology by activating the immune system. Here we report for the first time on passive immunotherapy for Tau in two well established transgenic models of Tau pathogenesis. We show that peripheral administration of two antibodies against pathological Tau forms significantly reduces biochemical Tau pathology in the JNPL3 mouse model. We further demonstrate that peripheral administration of the same antibodies in the more rapidly progressive P301S tauopathy model not only reduces Tau pathology quantitated by biochemical assays and immunohistochemistry, but also significantly delays the onset of motor function decline and weight loss. This is accompanied by a reduction in neurospheroids, providing direct evidence of reduced neurodegeneration. Thus, passive immunotherapy is effective at preventing the buildup of intracellular Tau pathology, neurospheroids, and associated symptoms, although the exact mechanism remains uncertain. Tau immunotherapy should therefore be considered as a therapeutic approach for the treatment of Alzheimer disease and other tauopathies. PMID:21841002

Methylene blue does not reverse existing neurofibrillary tangle pathology in the rTg4510 mouse model of tauopathy.

PubMed

Spires-Jones, Tara L; Friedman, Taylor; Pitstick, Rose; Polydoro, Manuela; Roe, Allyson; Carlson, George A; Hyman, Bradley T

2014-03-06

Alzheimer's disease is characterized pathologically by aggregation of amyloid beta into senile plaques and aggregation of pathologically modified tau into neurofibrillary tangles. While changes in amyloid processing are strongly implicated in disease initiation, the recent failure of amyloid-based therapies has highlighted the importance of tau as a therapeutic target. "Tangle busting" compounds including methylene blue and analogous molecules are currently being evaluated as therapeutics in Alzheimer's disease. Previous studies indicated that methylene blue can reverse tau aggregation in vitro after 10 min, and subsequent studies suggested that high levels of drug reduce tau protein levels (assessed biochemically) in vivo. Here, we tested whether methylene blue could remove established neurofibrillary tangles in the rTg4510 model of tauopathy, which develops robust tangle pathology. We find that 6 weeks of methylene blue dosing in the water from 16 months to 17.5 months of age decreases soluble tau but does not remove sarkosyl insoluble tau, or histologically defined PHF1 or Gallyas positive tangle pathology. These data indicate that methylene blue treatment will likely not rapidly reverse existing tangle pathology. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Methylene blue does not reverse existing neurofibrillary tangle pathology in the rTg4510 mouse model of tauopathy

PubMed Central

Spires-Jones, Tara L; Friedman, Taylor; Pitstick, Rose; Polydoro, Manuela; Roe, Allyson; Carlson, George A; Hyman, Bradley T

2014-01-01

Alzheimer's disease is characterized pathologically by aggregation of amyloid beta into senile plaques and aggregation of pathologically modified tau into neurofibrillary tangles. While changes in amyloid processing are strongly implicated in disease initiation, the recent failure of amyloid-based therapies has highlighted the importance of tau as a therapeutic target. “Tangle busting” compounds including methylene blue and analogous molecules are currently being evaluated as therapeutics in Alzheimer's disease. Previous studies indicated that methylene blue can reverse tau aggregation in vitro after 10 minutes, and subsequent studies suggested that high levels of drug reduce tau protein levels (assessed biochemically) in vivo. Here, we tested whether methylene blue could remove established neurofibrillary tangles in the rTg4510 model of tauopathy, which develops robust tangle pathology. We find that 6 weeks of methylene blue dosing in the water from 16 months to 17.5 months of age decreases soluble tau but does not remove sarkosyl insoluble tau, or histologically defined PHF1 or Gallyas positive tangle pathology. These data indicate that methylene blue treatment will likely not rapidly reverse existing tangle pathology. PMID:24462887

Sex-related alterations of gut microbiota composition in the BTBR mouse model of autism spectrum disorder.

PubMed

Coretti, Lorena; Cristiano, Claudia; Florio, Ermanno; Scala, Giovanni; Lama, Adriano; Keller, Simona; Cuomo, Mariella; Russo, Roberto; Pero, Raffaela; Paciello, Orlando; Mattace Raso, Giuseppina; Meli, Rosaria; Cocozza, Sergio; Calignano, Antonio; Chiariotti, Lorenzo; Lembo, Francesca

2017-03-28

Alterations of microbiota-gut-brain axis have been invoked in the pathogenesis of autism spectrum disorders (ASD). Mouse models could represent an excellent tool to understand how gut dysbiosis and related alterations may contribute to autistic phenotype. In this study we paralleled gut microbiota (GM) profiles, behavioral characteristics, intestinal integrity and immunological features of colon tissues in BTBR T + tf/J (BTBR) inbred mice, a well established animal model of ASD. Sex differences, up to date poorly investigated in animal models, were specifically addressed. Results showed that BTBR mice of both sexes presented a marked intestinal dysbiosis, alterations of behavior, gut permeability and immunological state with respect to prosocial C57BL/6j (C57) strain. Noticeably, sex-related differences were clearly detected. We identified Bacteroides, Parabacteroides, Sutterella, Dehalobacterium and Oscillospira genera as key drivers of sex-specific gut microbiota profiles associated with selected pathological traits. Taken together, our findings indicate that alteration of GM in BTBR mice shows relevant sex-associated differences and supports the use of BTBR mouse model to dissect autism associated microbiota-gut-brain axis alteration.

The mitochondria-targeted antioxidant MitoQ prevents loss of spatial memory retention and early neuropathology in a transgenic mouse model of Alzheimer's disease.

PubMed

McManus, Meagan J; Murphy, Michael P; Franklin, James L

2011-11-02

Considerable evidence suggests that mitochondrial dysfunction and oxidative stress contribute to the progression of Alzheimer's disease (AD). We examined the ability of the novel mitochondria-targeted antioxidant MitoQ (mitoquinone mesylate: [10-(4,5-dimethoxy-2-methyl-3,6-dioxo-1,4-cycloheexadienl-yl) decyl triphenylphosphonium methanesulfonate]) to prevent AD-like pathology in mouse cortical neurons in cell culture and in a triple transgenic mouse model of AD (3xTg-AD). MitoQ attenuated β-amyloid (Aβ)-induced neurotoxicity in cortical neurons and also prevented increased production of reactive species and loss of mitochondrial membrane potential (Δψ(m)) in them. To determine whether the mitochondrial protection conferred by MitoQ was sufficient to prevent the emergence of AD-like neuropathology in vivo, we treated young female 3xTg-AD mice with MitoQ for 5 months and analyzed the effect on the progression of AD-like pathologies. Our results show that MitoQ prevented cognitive decline in these mice as well as oxidative stress, Aβ accumulation, astrogliosis, synaptic loss, and caspase activation in their brains. The work presented herein suggests a central role for mitochondria in neurodegeneration and provides evidence supporting the use of mitochondria-targeted therapeutics in diseases involving oxidative stress and metabolic failure, namely AD.

The Mitochondria-Targeted Antioxidant MitoQ Prevents Loss of Spatial Memory Retention and Early Neuropathology in a Transgenic Mouse Model of Alzheimer’s Disease

PubMed Central

McManus, Meagan J.; Murphy, Michael P.; Franklin, James L.

2012-01-01

Considerable evidence suggests that mitochondrial dysfunction and oxidative stress contribute to the progression of Alzheimer’s disease (AD). We examined the ability of the novel mitochondria-targeted antioxidant MitoQ (mitoquinone mesylate: [10-(4,5-dimethoxy-2-methyl-3,6-dioxo-1,4-cycloheexadienlyl) decyl triphenylphosphonium methanesulfonate]) to prevent AD-like pathology in mouse cortical neurons in cell culture and in a triple transgenic mouse model of AD (3xTg-AD). MitoQ attenuated β-amyloid (Aβ)-induced neurotoxicity in cortical neurons and also prevented increased production of reactive species and loss of mitochondrial membrane potential (Δψm) in them. To determine whether the mitochondrial protection conferred by MitoQ was sufficient to prevent the emergence of AD-like neuropathology in vivo, we treated young female 3xTg-AD mice with MitoQ for 5 months and analyzed the effect on the progression of AD-like pathologies. Our results show that MitoQ prevented cognitive decline in these mice as well as oxidative stress, Aβ accumulation, astrogliosis, synaptic loss, and caspase activation in their brains. The work presented herein suggests a central role for mitochondria in neurodegeneration and provides evidence supporting the use of mitochondria-targeted therapeutics in diseases involving oxidative stress and metabolic failure, namely AD. PMID:22049413

Motor neuron cell-nonautonomous rescue of spinal muscular atrophy phenotypes in mild and severe transgenic mouse models

PubMed Central

Liu, Ying Hsiu; Sahashi, Kentaro; Rigo, Frank; Bennett, C. Frank

2015-01-01

Survival of motor neuron (SMN) deficiency causes spinal muscular atrophy (SMA), but the pathogenesis mechanisms remain elusive. Restoring SMN in motor neurons only partially rescues SMA in mouse models, although it is thought to be therapeutically essential. Here, we address the relative importance of SMN restoration in the central nervous system (CNS) versus peripheral tissues in mouse models using a therapeutic splice-switching antisense oligonucleotide to restore SMN and a complementary decoy oligonucleotide to neutralize its effects in the CNS. Increasing SMN exclusively in peripheral tissues completely rescued necrosis in mild SMA mice and robustly extended survival in severe SMA mice, with significant improvements in vulnerable tissues and motor function. Our data demonstrate a critical role of peripheral pathology in the mortality of SMA mice and indicate that peripheral SMN restoration compensates for its deficiency in the CNS and preserves motor neurons. Thus, SMA is not a cell-autonomous defect of motor neurons in SMA mice. PMID:25583329

Alzheimer disease in a mouse model: MR imaging-guided focused ultrasound targeted to the hippocampus opens the blood-brain barrier and improves pathologic abnormalities and behavior.

PubMed

Burgess, Alison; Dubey, Sonam; Yeung, Sharon; Hough, Olivia; Eterman, Naomi; Aubert, Isabelle; Hynynen, Kullervo

2014-12-01

To validate whether repeated magnetic resonance (MR) imaging-guided focused ultrasound treatments targeted to the hippocampus, a brain structure relevant for Alzheimer disease ( AD Alzheimer disease ), could modulate pathologic abnormalities, plasticity, and behavior in a mouse model. All animal procedures were approved by the Animal Care Committee and are in accordance with the Canadian Council on Animal Care. Seven-month-old transgenic (TgCRND8) (Tg) mice and their nontransgenic (non-Tg) littermates were entered in the study. Mice were treated weekly with MR imaging-guided focused ultrasound in the bilateral hippocampus (1.68 MHz, 10-msec bursts, 1-Hz burst repetition frequency, 120-second total duration). After 1 month, spatial memory was tested in the Y maze with the novel arm prior to sacrifice and immunohistochemical analysis. The data were compared by using unpaired t tests and analysis of variance with Tukey post hoc analysis. Untreated Tg mice spent 61% less time than untreated non-Tg mice exploring the novel arm of the Y maze because of spatial memory impairments (P < .05). Following MR imaging-guided focused ultrasound, Tg mice spent 99% more time exploring the novel arm, performing as well as their non-Tg littermates. Changes in behavior were correlated with a reduction of the number and size of amyloid plaques in the MR imaging-guided focused ultrasound-treated animals (P < .01). Further, after MR imaging-guided focused ultrasound treatment, there was a 250% increase in the number of newborn neurons in the hippocampus (P < .01). The newborn neurons had longer dendrites and more arborization after MR imaging-guided focused ultrasound, as well (P < .01). Repeated MR imaging-guided focused ultrasound treatments led to spatial memory improvement in a Tg mouse model of AD Alzheimer disease . The behavior changes may be mediated by decreased amyloid pathologic abnormalities and increased neuronal plasticity. © RSNA, 2014.

Early intervention with an estrogen receptor β-selective phytoestrogenic formulation prolongs survival, improves spatial recognition memory, and slows progression of amyloid pathology in a female mouse model of Alzheimer's disease.

PubMed

Zhao, Liqin; Mao, Zisu; Chen, Shuhua; Schneider, Lon S; Brinton, Roberta D

2013-01-01

Our recent developments have yielded a novel phytoestrogenic formulation, referred to as the phyto-β-SERM formulation, which exhibits an 83-fold binding selectivity for the estrogen receptor subtype β (ERβ) over ERα. Earlier studies indicate that the phyto-β-SERM formulation is neuroprotective and promotes estrogenic mechanisms in the brain while devoid of feminizing activity in the periphery. Further investigation in a mouse model of human menopause indicates that chronic exposure to the phyto-β-SERM formulation at a clinically relevant dosage prevents/alleviates menopause-related climacteric symptoms. This study assessed the efficacy, in an early intervention paradigm, of the phyto-β-SERM formulation in the regulation of early stages of physical and neurological changes associated with Alzheimer's disease (AD) in a female triple transgenic mouse model of AD. Results demonstrated that, when initiated prior to the appearance of AD pathology, a 9-month dietary supplementation with the phyto-β-SERM formulation promoted physical health, prolonged survival, improved spatial recognition memory, and attenuated amyloid-β deposition and plaque formation in the brains of treated AD mice. In comparison, dietary supplementation of a commercial soy extract preparation showed no effect on cognitive measures, although it appeared to have a positive impact on amyloid pathology. In overall agreement with the behavioral and histological outcomes, results from a gene expression profiling analysis offered insights on the underlying molecular mechanisms associated with the two dietary treatments. In particular, the data suggests that there may be a crosstalk between ERβ and glycogen synthase kinase 3 signaling pathways that could play a role in conferring ERβ-mediated neuroprotection against AD. Taken together, these results support the therapeutic potential of the phyto-β-SERM formulation for prevention and/or early intervention of AD, and warrants further investigations in human studies.

Mammary Gland Pathology Subsequent to Acute Infection with Strong versus Weak Biofilm Forming Staphylococcus aureus Bovine Mastitis Isolates: A Pilot Study Using Non-Invasive Mouse Mastitis Model.

PubMed

Gogoi-Tiwari, Jully; Williams, Vincent; Waryah, Charlene Babra; Costantino, Paul; Al-Salami, Hani; Mathavan, Sangeetha; Wells, Kelsi; Tiwari, Harish Kumar; Hegde, Nagendra; Isloor, Shrikrishna; Al-Sallami, Hesham; Mukkur, Trilochan

2017-01-01

Biofilm formation by Staphylococcus aureus is an important virulence attribute because of its potential to induce persistent antibiotic resistance, retard phagocytosis and either attenuate or promote inflammation, depending upon the disease syndrome, in vivo. This study was undertaken to evaluate the potential significance of strength of biofilm formation by clinical bovine mastitis-associated S. aureus in mammary tissue damage by using a mouse mastitis model. Two S. aureus strains of the same capsular phenotype with different biofilm forming strengths were used to non-invasively infect mammary glands of lactating mice. Biofilm forming potential of these strains were determined by tissue culture plate method, ica typing and virulence gene profile per detection by PCR. Delivery of the infectious dose of S. aureus was directly through the teat lactiferous duct without invasive scraping of the teat surface. Both bacteriological and histological methods were used for analysis of mammary gland pathology of mice post-infection. Histopathological analysis of the infected mammary glands revealed that mice inoculated with the strong biofilm forming S. aureus strain produced marked acute mastitic lesions, showing profuse infiltration predominantly with neutrophils, with evidence of necrosis in the affected mammary glands. In contrast, the damage was significantly less severe in mammary glands of mice infected with the weak biofilm-forming S. aureus strain. Although both IL-1β and TNF-α inflammatory biomarkers were produced in infected mice, level of TNF-α produced was significantly higher (p<0.05) in mice inoculated with strong biofilm forming S. aureus than the weak biofilm forming strain. This finding suggests an important role of TNF-α in mammary gland pathology post-infection with strong biofilm-forming S. aureus in the acute mouse mastitis model, and offers an opportunity for the development of novel strategies for reduction of mammary tissue damage, with or without use of antimicrobials and/or anti-inflammatory compounds for the treatment of bovine mastitis.

Early social enrichment rescues adult behavioral and brain abnormalities in a mouse model of fragile X syndrome.

PubMed

Oddi, Diego; Subashi, Enejda; Middei, Silvia; Bellocchio, Luigi; Lemaire-Mayo, Valerie; Guzmán, Manuel; Crusio, Wim E; D'Amato, Francesca R; Pietropaolo, Susanna

2015-03-13

Converging lines of evidence support the use of environmental stimulation to ameliorate the symptoms of a variety of neurodevelopmental disorders. Applying these interventions at very early ages is critical to achieve a marked reduction of the pathological phenotypes. Here we evaluated the impact of early social enrichment in Fmr1-KO mice, a genetic mouse model of fragile X syndrome (FXS), a major developmental disorder and the most frequent monogenic cause of autism. Enrichment was achieved by providing male KO pups and their WT littermates with enhanced social stimulation, housing them from birth until weaning with the mother and an additional nonlactating female. At adulthood they were tested for locomotor, social, and cognitive abilities; furthermore, dendritic alterations were assessed in the hippocampus and amygdala, two brain regions known to be involved in the control of the examined behaviors and affected by spine pathology in Fmr1-KOs. Enrichment rescued the behavioral FXS-like deficits displayed in adulthood by Fmr1-KO mice, that is, hyperactivity, reduced social interactions, and cognitive deficits. Early social enrichment also eliminated the abnormalities shown by adult KO mice in the morphology of hippocampal and amygdala dendritic spines, namely an enhanced density of immature vs mature types. Importantly, enrichment did not induce neurobehavioral changes in WT mice, thus supporting specific effects on FXS-like pathology. These findings show that early environmental stimulation has profound and long-term beneficial effects on the pathological FXS phenotype, thereby encouraging the use of nonpharmacological interventions for the treatment of this and perhaps other neurodevelopmental diseases.

The clinical implications of mouse models of enhanced anxiety

PubMed Central

Sartori, Simone B; Landgraf, Rainer; Singewald, Nicolas

2011-01-01

Mice are increasingly overtaking the rat model organism in important aspects of anxiety research, including drug development. However, translating the results obtained in mouse studies into information that can be applied in clinics remains challenging. One reason may be that most of the studies so far have used animals displaying ‘normal’ anxiety rather than ‘psychopathological’ animal models with abnormal (elevated) anxiety, which more closely reflect core features and sensitivities to therapeutic interventions of human anxiety disorders, and which would, thus, narrow the translational gap. Here, we discuss manipulations aimed at persistently enhancing anxiety-related behavior in the laboratory mouse using phenotypic selection, genetic techniques and/or environmental manipulations. It is hoped that such models with enhanced construct validity will provide improved ways of studying the neurobiology and treatment of pathological anxiety. Examples of findings from mouse models of enhanced anxiety-related behavior will be discussed, as well as their relation to findings in anxiety disorder patients regarding neuroanatomy, neurobiology, genetic involvement and epigenetic modifications. Finally, we highlight novel targets for potential anxiolytic pharmacotherapeutics that have been established with the help of research involving mice. Since the use of psychopathological mouse models is only just beginning to increase, it is still unclear as to the extent to which such approaches will enhance the success rate of drug development in translating identified therapeutic targets into clinical trials and, thus, helping to introduce the next anxiolytic class of drugs. PMID:21901080

Novel In Vivo Model for Combinatorial Fluorescence Labeling in Mouse Prostate

PubMed Central

Fang, Xiaolan; Gyabaah, Kenneth; Nickkholgh, Bita; Cline, J. Mark; Balaji, K.C.

2015-01-01

BACKGROUND The epithelial layer of prostate glands contains several types of cells, including luminal and basal cells. Yet there is paucity of animal models to study the cellular origin of normal or neoplastic development in the prostate to facilitate the treatment of heterogenous prostate diseases by targeting individual cell lineages. METHODS We developed a mouse model that expresses different types of fluorescent proteins (XFPs) specifically in prostatic cells. Using an in vivo stochastic fluorescent protein combinatorial strategy, XFP signals were expressed specifically in prostate of Protein Kinase D1 (PKD1) knock-out, K-RasG12D knock-in, and Phosphatase and tensin homolog (PTEN) and PKD1 double knock-out mice under the control of PB-Cre promoter. RESULTS In vivo XFP signals were observed in prostate of PKD1 knock-out, K-RasG12D knock-in, and PTEN PKD1 double knock-out mice, which developed normal, hyperplastic, and neoplastic prostate, respectively. The patchy expression pattern of XFPs in neoplasia tissue indicated the clonal origin of cancer cells in the prostate. CONCLUSIONS The transgenic mouse models demonstrate combinatorial fluorescent protein expression in normal and cancerous prostatic tissues. This novel prostate-specific fluorescent labeled mouse model, which we named Prorainbow, could be useful in studying benign and malignant pathology of prostate. PMID:25753731

Novel In Vivo model for combinatorial fluorescence labeling in mouse prostate.

PubMed

Fang, Xiaolan; Gyabaah, Kenneth; Nickkholgh, Bita; Cline, J Mark; Balaji, K C

2015-06-15

The epithelial layer of prostate glands contains several types of cells, including luminal and basal cells. Yet there is paucity of animal models to study the cellular origin of normal or neoplastic development in the prostate to facilitate the treatment of heterogenous prostate diseases by targeting individual cell lineages. We developed a mouse model that expresses different types of fluorescent proteins (XFPs) specifically in prostatic cells. Using an in vivo stochastic fluorescent protein combinatorial strategy, XFP signals were expressed specifically in prostate of Protein Kinase D1 (PKD1) knock-out, K-Ras(G) (12) (D) knock-in, and Phosphatase and tensin homolog (PTEN) and PKD1 double knock-out mice under the control of PB-Cre promoter. In vivo XFP signals were observed in prostate of PKD1 knock-out, K-Ras(G) (12) (D) knock-in, and PTEN PKD1 double knock-out mice, which developed normal, hyperplastic, and neoplastic prostate, respectively. The patchy expression pattern of XFPs in neoplasia tissue indicated the clonal origin of cancer cells in the prostate. The transgenic mouse models demonstrate combinatorial fluorescent protein expression in normal and cancerous prostatic tissues. This novel prostate-specific fluorescent labeled mouse model, which we named Prorainbow, could be useful in studying benign and malignant pathology of prostate. © 2015 Wiley Periodicals, Inc.

Preclinical Mouse Models of Neurofibromatosis

DTIC Science & Technology

2005-11-01

and NF2-deficient human cells and in cells from Nf1 and Nf2 mutant mice. Genetic analysis of human and murine tumors has provided compelling...lethal myeloproliferative disorder (MPD) characterized by over-production of infiltrative myeloid cells (13). JMML has been modeled in mice by...tumor development for 18 months after exposure. Pathologic analysis was performed on 91% of the Shannon, K.M. 11 study cohort, including 95 of 104

Reducing Mitochondrial ROS Improves Disease-related Pathology in a Mouse Model of Ataxia-telangiectasia

PubMed Central

D'Souza, Anthony D; Parish, Ian A; Krause, Diane S; Kaech, Susan M; Shadel, Gerald S

2013-01-01

The disease ataxia-telangiectasia (A-T) has no cure and few treatment options. It is caused by mutations in the ATM kinase, which functions in the DNA-damage response and redox sensing. In addition to severe cerebellar degeneration, A-T pathology includes cancer predisposition, sterility, immune system dysfunction, and bone marrow abnormalities. These latter phenotypes are recapitulated in the ATM null (ATM−/−) mouse model of the disease. Since oxidative stress and mitochondrial dysfunction are implicated in A-T, we determined whether reducing mitochondrial reactive oxygen species (ROS) via overexpression of catalase targeted to mitochondria (mCAT) alleviates A-T–related pathology in ATM−/− mice. We found that mCAT has many beneficial effects in this context, including reduced propensity to develop thymic lymphoma, improved bone marrow hematopoiesis and macrophage differentiation in vitro, and partial rescue of memory T-cell developmental defects. Our results suggest that positive effects observed on cancer development may be linked to mCAT reducing mitochondrial ROS, lactate production, and TORC1 signaling in transforming double-positive cells, whereas beneficial effects in memory T cells appear to be TORC1-independent. Altogether, this study provides proof-of-principle that reducing mitochondrial ROS production per se may be therapeutic for the disease, which may have advantages compared with more general antioxidant strategies. PMID:23011031

Deficits in hippocampal-dependent transfer generalization learning accompany synaptic dysfunction in a mouse model of amyloidosis.

PubMed

Montgomery, Karienn S; Edwards, George; Levites, Yona; Kumar, Ashok; Myers, Catherine E; Gluck, Mark A; Setlow, Barry; Bizon, Jennifer L

2016-04-01

Elevated β-amyloid and impaired synaptic function in hippocampus are among the earliest manifestations of Alzheimer's disease (AD). Most cognitive assessments employed in both humans and animal models, however, are insensitive to this early disease pathology. One critical aspect of hippocampal function is its role in episodic memory, which involves the binding of temporally coincident sensory information (e.g., sights, smells, and sounds) to create a representation of a specific learning epoch. Flexible associations can be formed among these distinct sensory stimuli that enable the "transfer" of new learning across a wide variety of contexts. The current studies employed a mouse analog of an associative "transfer learning" task that has previously been used to identify risk for prodromal AD in humans. The rodent version of the task assesses the transfer of learning about stimulus features relevant to a food reward across a series of compound discrimination problems. The relevant feature that predicts the food reward is unchanged across problems, but an irrelevant feature (i.e., the context) is altered. Experiment 1 demonstrated that C57BL6/J mice with bilateral ibotenic acid lesions of hippocampus were able to discriminate between two stimuli on par with control mice; however, lesioned mice were unable to transfer or apply this learning to new problem configurations. Experiment 2 used the APPswe PS1 mouse model of amyloidosis to show that robust impairments in transfer learning are evident in mice with subtle β-amyloid-induced synaptic deficits in the hippocampus. Finally, Experiment 3 confirmed that the same transfer learning impairments observed in APPswePS1 mice were also evident in the Tg-SwDI mouse, a second model of amyloidosis. Together, these data show that the ability to generalize learned associations to new contexts is disrupted even in the presence of subtle hippocampal dysfunction and suggest that, across species, this aspect of hippocampal-dependent learning may be useful for early identification of AD-like pathology. © 2015 Wiley Periodicals, Inc.

Deficits in hippocampal-dependent transfer generalization learning accompany synaptic dysfunction in a mouse model of amyloidosis

PubMed Central

Montgomery, Karienn S.; Edwards, George; Levites, Yona; Kumar, Ashok; Myers, Catherine E.; Gluck, Mark A.; Setlow, Barry; Bizon, Jennifer L.

2015-01-01

Elevated β-amyloid and impaired synaptic function in hippocampus are among the earliest manifestations of Alzheimer’s disease (AD). Most cognitive assessments employed in both humans and animal models, however, are insensitive to this early disease pathology. One critical aspect of hippocampal function is its role in episodic memory, which involves the binding of temporally coincident sensory information (e.g., sights, smells, and sounds) to create a representation of a specific learning epoch. Flexible associations can be formed among these distinct sensory stimuli that enable the “transfer” of new learning across a wide variety of contexts. The current studies employed a mouse analog of an associative “transfer learning” task that has previously been used to identify risk for prodromal AD in humans. The rodent version of the task assesses the transfer of learning about stimulus features relevant to a food reward across a series of compound discrimination problems. The relevant feature that predicts the food reward is unchanged across problems, but an irrelevant feature (i.e., the context) is altered. Experiment 1 demonstrated that C57BL6/J mice with bilateral ibotenic acid lesions of hippocampus were able to discriminate between two stimuli on par with control mice; however, lesioned mice were unable to transfer or apply this learning to new problem configurations. Experiment 2 used the APPswePS1 mouse model of amyloidosis to show that robust impairments in transfer learning are evident in mice with subtle β amyloid-induced synaptic deficits in the hippocampus. Finally, Experiment 3 confirmed that the same transfer learning impairments observed in APPswePS1 mice were also evident in the Tg-SwDI mouse, a second model of amyloidosis. Together, these data show that the ability to generalize learned associations to new contexts is disrupted even in the presence of subtle hippocampal dysfunction and suggest that, across species, this aspect of hippocampal-dependent learning may be useful for early identification of AD-like pathology. PMID:26418152

Investigation into metastatic processes and the therapeutic effects of gemcitabine on human pancreatic cancer using an orthotopic SUIT-2 pancreatic cancer mouse model

PubMed Central

Higuchi, Tamami; Yokobori, Takehiko; Naito, Tomoharu; Kakinuma, Chihaya; Hagiwara, Shinji; Nishiyama, Masahiko; Asao, Takayuki

2018-01-01

Prognosis of pancreatic cancer is poor, thus the development of novel therapeutic drugs is necessary. During preclinical studies, appropriate models are essential for evaluating drug efficacy. The present study sought to determine the ideal pancreatic cancer mouse model for reliable preclinical testing. Such a model could accurately reflect human pancreatic cancer phenotypes and predict future clinical trial results. Systemic pathology analysis was performed in an orthotopic transplantation model to prepare model mice for use in preclinical studies, mimicking the progress of human pancreatic cancer. The location and the timing of inoculated cancer cell metastases, pathogenesis and cause of fatality were analyzed. Furthermore, the efficacy of gemcitabine, a key pancreatic cancer drug, was evaluated in this model where liver metastasis and peritoneal dissemination occur. Results indicated that the SUIT-2 orthotopic pancreatic cancer model was similar to the phenotypic sequential progression of human pancreatic cancer, with extra-pancreatic invasion, intra-peritoneal dissemination and other hematogenous organ metastases. Notably, survival was prolonged by administering gemcitabine to mice with metastasized pancreatic cancer. Furthermore, the detailed effects of gemcitabine on the primary tumor and metastatic tumor lesions were pathologically evaluated in mice. The present study indicated the model accurately depicted pancreatic cancer development and metastasis. Furthermore, the detailed effects of pancreatic cancer drugs on the primary tumor and on metastatic tumor lesions. We present this model as a potential new standard for new drug development in pancreatic cancer. PMID:29435042

Prediabetes-induced vascular alterations exacerbate central pathology in APPswe/PS1dE9 mice.

PubMed

Ramos-Rodriguez, Juan Jose; Ortiz-Barajas, Oscar; Gamero-Carrasco, Carlos; de la Rosa, Pablo Romero; Infante-Garcia, Carmen; Zopeque-Garcia, Nuria; Lechuga-Sancho, Alfonso M; Garcia-Alloza, Monica

2014-10-01

Age remains the main risk factor for developing Alzheimer's disease (AD) although certain metabolic alterations, including prediabetes and hyperinsulinemia, also increase this risk. We present a mouse model of AD (APPswe/PS1dE9 mouse) with severe hyperinsulinemia induced by long-term high fat diet (HFD) treatment. After 23 weeks on HFD learning and memory processes were compromised. We observed a significant increase in tau hyperphosphorylation and Aβ pathology, including Aβ levels and amyloid burden. Microglia activation was also significantly increased in HFD-treated mice, both in close proximity to and far from senile plaques. Insulin degrading enzyme and neprilysin levels were not affected, suggesting that Aβ degradation pathways were preserved, whereas we detected an increase in spontaneous cortical bleeding that could underlay an impairment of Aβ interstitial fluid drainage, contributing to the increase in Aβ deposition in APP/PS1-HFD mice. Altogether our data suggest that early hyperinsulinemia is enough to exacerbate AD pathology observed in APP/PS1 mice, and supports the role of insulin-resistance therapies to stop or delay central complications associated. Copyright © 2014 Elsevier Ltd. All rights reserved.

Treatment of hypoxic-ischemic encephalopathy in mouse by transplantation of embryonic stem cell-derived cells.

PubMed

Ma, Jie; Wang, Yu; Yang, Jianhua; Yang, Min; Chang, Keun-A; Zhang, Linhua; Jiang, Feng; Li, Yi; Zhang, Zhonggong; Heo, Chaejeong; Suh, Yoo-Hun

2007-07-01

A 7-day-old hypoxic-ischemic encephalopathy (HIE) mouse model was used to study the effect of transplantation of embryonic stem (ES) cell-derived cells on the HIE. After the inducement in vitro, the ES cell-derived cells expressed Nestin and MAP-2, rather than GFAP mRNA. After transplantation, ES cell-derived cells can survive, migrate into the injury site, and specifically differentiate into neurons, showing improvement of the learning ability and memory of the HIE mouse at 8 months post-transplantation. The non-grafted HIE mouse brain showed typical pathological changes in the hippocampus and cerebral cortex, where the number of neurons was reduced, while in the cell graft group, number of the neurons increased in the same regions. Although further study is necessary to elucidate the precise mechanisms responsible for this functional recovery, we believe that ES cells have advantages for use as a donor source in HIE.

Raman spectroscopy reveals spectroscopic changes in histologically normal retinas in a mouse model of alpha-synucleinopathy

USDA-ARS?s Scientific Manuscript database

The retina is an extension of the nervous system and is accessible for in vivo assessments. We have previously demonstrated changes in retinal function and pathology associated with scrapie, TME and BSE. The purpose of this work was to determine the utility of the retina to identify early CNS change...

Identification and characterization of poorly differentiated invasive carcinomas in a mouse model of pancreatic neuroendocrine tumorigenesis.

PubMed

Hunter, Karen E; Quick, Marsha L; Sadanandam, Anguraj; Hanahan, Douglas; Joyce, Johanna A

2013-01-01

Pancreatic neuroendocrine tumors (PanNETs) are a relatively rare but clinically challenging tumor type. In particular, high grade, poorly-differentiated PanNETs have the worst patient prognosis, and the underlying mechanisms of disease are poorly understood. In this study we have identified and characterized a previously undescribed class of poorly differentiated PanNETs in the RIP1-Tag2 mouse model. We found that while the majority of tumors in the RIP1-Tag2 model are well-differentiated insulinomas, a subset of tumors had lost multiple markers of beta-cell differentiation and were highly invasive, leading us to term them poorly differentiated invasive carcinomas (PDICs). In addition, we found that these tumors exhibited a high mitotic index, resembling poorly differentiated (PD)-PanNETs in human patients. Interestingly, we identified expression of Id1, an inhibitor of DNA binding gene, and a regulator of differentiation, specifically in PDIC tumor cells by histological analysis. The identification of PDICs in this mouse model provides a unique opportunity to study the pathology and molecular characteristics of PD-PanNETs.

Proceedings of the 2010 National Toxicology Program Satellite Symposium

PubMed Central

Adams, E. Terence; Auerbach, Scott; Blackshear, Pamela E.; Bradley, Alys; Gruebbel, Margarita M.; Little, Peter B.; Malarkey, David; Maronpot, Robert; McKay, Jennifer S.; Miller, Rodney A.; Moore, Rebecca R.; Morrison, James P.; Nyska, Abraham; Ramot, Yuval; Rao, Deepa; Suttie, Andrew; Wells, Monique Y.; Willson, Gabrielle A.; Elmore, Susan A.

2011-01-01

The 2010 annual National Toxicology Program (NTP) Satellite Symposium, entitled “Pathology Potpourri,” was held in Chicago, Illinois, in advance of the scientific symposium sponsored jointly by the Society of Toxicologic Pathology (STP) and the International Federation of Societies of Toxicologic Pathologists (IFSTP). The goal of the annual NTP Symposium is to present current diagnostic pathology or nomenclature issues to the toxicologic pathology community. This article presents summaries of the speakers' presentations, including diagnostic or nomenclature issues that were presented, along with select images that were used for voting or discussion. Some topics covered during the symposium included a comparison of rat and mouse hepatocholangiocarcinoma, a comparison of cholangiofibrosis and cholangiocarcinoma in rats, a mixed pancreatic neoplasm with acinar and islet cell components, an unusual preputial gland tumor, renal hyaline glomerulopathy in rats and mice, eosinophilic substance in the nasal septum of mice, INHAND nomenclature for proliferative and nonproliferative lesions of the CNS/PNS, retinal gliosis in a rat, fibroadnexal hamartoma in rats, intramural plaque in a mouse, a treatment-related chloracne-like lesion in mice, and an overview of mouse ovarian tumors. PMID:21177527

Cardiac c-Kit Biology Revealed by Inducible Transgenesis.

PubMed

Gude, Natalie A; Firouzi, Fareheh; Broughton, Kathleen M; Ilves, Kelli; Nguyen, Kristine P; Payne, Christina R; Sacchi, Veronica; Monsanto, Megan M; Casillas, Alexandria R; Khalafalla, Farid G; Wang, Bingyan J; Ebeid, David E; Alvarez, Roberto; Dembitsky, Walter P; Bailey, Barbara A; van Berlo, Jop; Sussman, Mark A

2018-06-22

Biological significance of c-Kit as a cardiac stem cell marker and role(s) of c-Kit+ cells in myocardial development or response to pathological injury remain unresolved because of varied and discrepant findings. Alternative experimental models are required to contextualize and reconcile discordant published observations of cardiac c-Kit myocardial biology and provide meaningful insights regarding clinical relevance of c-Kit signaling for translational cell therapy. The main objectives of this study are as follows: demonstrating c-Kit myocardial biology through combined studies of both human and murine cardiac cells; advancing understanding of c-Kit myocardial biology through creation and characterization of a novel, inducible transgenic c-Kit reporter mouse model that overcomes limitations inherent to knock-in reporter models; and providing perspective to reconcile disparate viewpoints on c-Kit biology in the myocardium. In vitro studies confirm a critical role for c-Kit signaling in both cardiomyocytes and cardiac stem cells. Activation of c-Kit receptor promotes cell survival and proliferation in stem cells and cardiomyocytes of either human or murine origin. For creation of the mouse model, the cloned mouse c-Kit promoter drives Histone2B-EGFP (enhanced green fluorescent protein; H2BEGFP) expression in a doxycycline-inducible transgenic reporter line. The combination of c-Kit transgenesis coupled to H2BEGFP readout provides sensitive, specific, inducible, and persistent tracking of c-Kit promoter activation. Tagging efficiency for EGFP+/c-Kit+ cells is similar between our transgenic versus a c-Kit knock-in mouse line, but frequency of c-Kit+ cells in cardiac tissue from the knock-in model is 55% lower than that from our transgenic line. The c-Kit transgenic reporter model reveals intimate association of c-Kit expression with adult myocardial biology. Both cardiac stem cells and a subpopulation of cardiomyocytes express c-Kit in uninjured adult heart, upregulating c-Kit expression in response to pathological stress. c-Kit myocardial biology is more complex and varied than previously appreciated or documented, demonstrating validity in multiple points of coexisting yet heretofore seemingly irreconcilable published findings. © 2018 American Heart Association, Inc.

The peptidomimetic Vasotide targets two retinal VEGF receptors and reduces pathological angiogenesis in murine and nonhuman primate models of retinal disease

PubMed Central

Sidman, Richard L.; Li, Jianxue; Lawrence, Matthew; Hu, Wenzheng; Musso, Gary F.; Giordano, Ricardo J.; Cardó-Vila, Marina; Pasqualini, Renata; Arap, Wadih

2016-01-01

Blood vessel growth from preexisting vessels (angiogenesis) underlies many severe diseases including major blinding retinal diseases such as retinopathy of prematurity (ROP) and aged macular degeneration (AMD). This observation has driven development of antibody inhibitors that block a central factor in AMD, named vascular endothelial growth factor (VEGF), from binding to its receptors VEGFR-1 and VEGFR-2. However, some patients are insensitive to current anti-VEGF drugs or develop resistance, and the required repeated intravitreal injection of these large molecules is costly and clinically problematic. Here, we have evaluated a small cyclic retro-inverted peptidomimetic, D(Cys-Leu-Pro-Arg-Cys), abbreviated as D(CLPRC), and hereafter named Vasotide, that inhibits retinal angiogenesis by binding selectively to the VEGF receptors, VEGFR-1 and Neuropilin-1 (NRP-1). Delivery of Vasotide in eye drops or via intraperitoneal injection in a laser-induced monkey model of human wet AMD, a mouse genetic knockout model of the AMD subtype called retinal angiomatous proliferation (RAP), and a mouse oxygen-induced model of retinopathy of prematurity (ROP) markedly decreased retinal angiogenesis in all three animal models. This prototype drug candidate is a promising new dual receptor inhibitor of the VEGF ligand with potential for translation into safer, less invasive applications to combat pathological angiogenesis in retinal disorders. PMID:26468327

A New Transgenic Mouse Model of Heart Failure and Cardiac Cachexia Raised by Sustained Activation of Met Tyrosine Kinase in the Heart.

PubMed

Sala, Valentina; Gatti, Stefano; Gallo, Simona; Medico, Enzo; Cantarella, Daniela; Cimino, James; Ponzetto, Antonio; Crepaldi, Tiziana

2016-01-01

Among other diseases characterized by the onset of cachexia, congestive heart failure takes a place of relevance, considering the high prevalence of this pathology in most European countries and in the United States, and is undergoing a rapid increase in developing countries. Actually, only few models of cardiac cachexia exist. Difficulties in the recruitment and follow-up of clinical trials implicate that new reproducible and well-characterized animal models are pivotal in developing therapeutic strategies for cachexia. We generated a new model of cardiac cachexia: a transgenic mouse expressing Tpr-Met receptor, the activated form of c-Met receptor of hepatocyte growth factor, specifically in the heart. We showed that the cardiac-specific induction of Tpr-Met raises a cardiac hypertrophic remodelling, which progresses into concentric hypertrophy with concomitant increase in Gdf15 mRNA levels. Hypertrophy progresses to congestive heart failure with preserved ejection fraction, characterized by reduced body weight gain and food intake and skeletal muscle wasting. Prevention trial by suppressing Tpr-Met showed that loss of body weight could be prevented. Skeletal muscle wasting was also associated with altered gene expression profiling. We propose transgenic Tpr-Met mice as a new model of cardiac cachexia, which will constitute a powerful tool to understand such complex pathology and test new drugs/approaches at the preclinical level.

Helicobacter cinaedi Induced Typhlocolitis in Rag-2-Deficient Mice

PubMed Central

Shen, Zeli; Feng, Yan; Rickman, Barry; Fox, James G.

2015-01-01

Background Helicobacter cinaedi, an enterohepatic helicobacter species (EHS), is an important human pathogen and is associated with a wide range of diseases, especially in immunocompromised patients. It has been convincingly demonstrated that innate immune response to certain pathogenic enteric bacteria is sufficient to initiate colitis and colon carcinogenesis in recombinase-activating gene (Rag)-2-deficient mice model. To better understand the mechanisms of human IBD and its association with development of colon cancer, we investigated whether H. cinaedi could induce pathological changes noted with murine enterohepatic helicobacter infections in the Rag2−/− mouse model. Materials and Methods Sixty 129SvEv Rag2−/− mice mouse were experimentally or sham infected orally with H. cinaedi strain CCUG 18818. Gastrointestinal pathology and immune responses in infected and control mice were analyzed at 3, 6 and 9 months postinfection (MPI). H. cinaedi colonized the cecum, colon, and stomach in infected mice. Results H. cinaedi induced typhlocolitis in Rag2−/− mice by 3 MPI and intestinal lesions became more severe by 9 MPI. H. cinaedi was also associated with the elevation of proinflammatory cytokines, interferon-γ, tumor-necrosis factor-α, IL-1β, IL-10; iNOS mRNA levels were also upregulated in the cecum of infected mice. However, changes in IL-4, IL-6, Cox-2, and c-myc mRNA expressions were not detected. Conclusions Our results indicated that the Rag2−/− mouse model will be useful to continue investigating the pathogenicity of H. cinaedi, and to study the association of host immune responses in IBD caused by EHS. PMID:25381744

Galactic Cosmic Radiation Leads to Cognitive Impairment and Increased Aβ Plaque Accumulation in a Mouse Model of Alzheimer’s Disease

PubMed Central

Cherry, Jonathan D.; Liu, Bin; Frost, Jeffrey L.; Lemere, Cynthia A.; Williams, Jacqueline P.; Olschowka, John A.; O’Banion, M. Kerry

2012-01-01

Galactic Cosmic Radiation consisting of high-energy, high-charged (HZE) particles poses a significant threat to future astronauts in deep space. Aside from cancer, concerns have been raised about late degenerative risks, including effects on the brain. In this study we examined the effects of 56Fe particle irradiation in an APP/PS1 mouse model of Alzheimer’s disease (AD). We demonstrated 6 months after exposure to 10 and 100 cGy 56Fe radiation at 1 GeV/µ, that APP/PS1 mice show decreased cognitive abilities measured by contextual fear conditioning and novel object recognition tests. Furthermore, in male mice we saw acceleration of Aβ plaque pathology using Congo red and 6E10 staining, which was further confirmed by ELISA measures of Aβ isoforms. Increases were not due to higher levels of amyloid precursor protein (APP) or increased cleavage as measured by levels of the β C-terminal fragment of APP. Additionally, we saw no change in microglial activation levels judging by CD68 and Iba-1 immunoreactivities in and around Aβ plaques or insulin degrading enzyme, which has been shown to degrade Aβ. However, immunohistochemical analysis of ICAM-1 showed evidence of endothelial activation after 100 cGy irradiation in male mice, suggesting possible alterations in Aβ trafficking through the blood brain barrier as a possible cause of plaque increase. Overall, our results show for the first time that HZE particle radiation can increase Aβ plaque pathology in an APP/PS1 mouse model of AD. PMID:23300905

Defining an Analytic Framework to Evaluate Quantitative MRI Markers of Traumatic Axonal Injury: Preliminary Results in a Mouse Closed Head Injury Model

PubMed Central

Sadeghi, N.; Namjoshi, D.; Irfanoglu, M. O.; Wellington, C.; Diaz-Arrastia, R.

2017-01-01

Diffuse axonal injury (DAI) is a hallmark of traumatic brain injury (TBI) pathology. Recently, the Closed Head Injury Model of Engineered Rotational Acceleration (CHIMERA) was developed to generate an experimental model of DAI in a mouse. The characterization of DAI using diffusion tensor magnetic resonance imaging (MRI; diffusion tensor imaging, DTI) may provide a useful set of outcome measures for preclinical and clinical studies. The objective of this study was to identify the complex neurobiological underpinnings of DTI features following DAI using a comprehensive and quantitative evaluation of DTI and histopathology in the CHIMERA mouse model. A consistent neuroanatomical pattern of pathology in specific white matter tracts was identified across ex vivo DTI maps and photomicrographs of histology. These observations were confirmed by voxelwise and regional analysis of DTI maps, demonstrating reduced fractional anisotropy (FA) in distinct regions such as the optic tract. Similar regions were identified by quantitative histology and exhibited axonal damage as well as robust gliosis. Additional analysis using a machine-learning algorithm was performed to identify regions and metrics important for injury classification in a manner free from potential user bias. This analysis found that diffusion metrics were able to identify injured brains almost with the same degree of accuracy as the histology metrics. Good agreement between regions detected as abnormal by histology and MRI was also found. The findings of this work elucidate the complexity of cellular changes that give rise to imaging abnormalities and provide a comprehensive and quantitative evaluation of the relative importance of DTI and histological measures to detect brain injury. PMID:28966972

Cellular and 3D Optical Coherence Tomography Assessment During the Initiation and Progression of Retinal Degeneration in the Ccl2/Cx3cr1-deficient Mouse

PubMed Central

Zhou, Yongdong; Sheets, Kristopher G.; Knott, Eric J.; Regan, Cornelius E.; Tuo, Jingsheng; Chan, Chi-Chao; Gordon, William C.; Bazan, Nicolas G.

2011-01-01

Retinal pathologies common to human eye diseases, including abnormal retinal pigment epithelial (RPE) cells, drusen-like accumulation, photoreceptor atrophy, and choroidal neovascularization, have been reported in the Ccl2/Cx3cr1-deficient mouse. The Ccl2 gene encodes the pro-inflammatory chemokine CCL2 (MCP-1), which is responsible for chemotactic recruitment of monocyte-derived macrophages to sites of inflammation. The Cx3cr1 gene encodes the fractalkine receptor, CX3CR1, and is required for accumulation of monocytes and microglia recruited via CCL2. Chemokine-mediated inflammation is implicated in retinal degenerative diseases such as diabetic retinopathy, age-related macular degeneration, retinitis pigmentosa, and uveoretinitis, and proper chemokine signaling from the RPE, Müller glia, and astrocytes is necessary to regulate leukocyte trafficking. Therefore, this mouse, possessing aberrant chemokine signaling coupled with retinal degenerative pathologies, presents an ideal opportunity to investigate the effect of altered signaling on retinal homeostasis and photoreceptor degeneration. Since this mouse is a recent development, more data covering the onset, location, and progression rate of pathologies is needed. In the present study we establish these parameters and show two photoreceptor cell death processes. Our observations of decreased glutamine synthetase and increased glial fibrillary acidic protein suggest that Müller cells respond very early within regions where lesions are forming. Finally, we demonstrate that retinal angiomatous proliferation contributes to pathological angiogenesis in this Ccl2/Cx3cr1-deficient mouse. PMID:21854772

Comprehensive proteomic profiles of mouse AApoAII amyloid fibrils provide insights into the involvement of lipoproteins in the pathology of amyloidosis.

PubMed

Miyahara, Hiroki; Sawashita, Jinko; Ishikawa, Eri; Yang, Mu; Ding, Xin; Liu, Yingye; Hachiya, Naomi; Kametani, Fuyuki; Yazaki, Masahide; Mori, Masayuki; Higuchi, Keiichi

2018-02-10

Amyloidosis is a disorder characterized by extracellular fibrillar deposits of misfolded proteins. The amyloid deposits commonly contain several non-fibrillar proteins as amyloid-associated proteins, but their roles in amyloidosis pathology are still unknown. In mouse senile amyloidosis, apolipoprotein A-II (ApoA-II) forms extracellular amyloid fibril (AApoAII) deposits with other proteins (AApoAII-associated proteins) in many organs. We previously reported that R1.P1-Apoa2 c mice provide a reproducible model of AApoAII amyloidosis. In order to investigate the sequential alterations of AApoAII-associated protein, we performed a proteomic analysis of amyloid fibrils extracted from mouse liver tissues that contained different levels of AApoAII deposition. We identified 6 AApoAII-associated proteins that constituted 20 of the top-ranked proteins in mice with severe AApoAII deposition. Although the amount of AApoAII-associated proteins increased with the progression of amyloidosis, the relative abundance of AApoAII-associated proteins changed little throughout the progression of amyloidosis. On the other hand, plasma levels of these proteins showed dramatic changes during the progression of amyloidosis. In addition, we confirmed that AApoAII-associated proteins were significantly associated with lipid metabolism based on functional enrichment analysis, and lipids were co-deposited with AApoAII fibrils from early stages of development of amyloidosis. Thus, these results demonstrate that lipoproteins are involved in AApoAII amyloidosis pathology. This study presented proteomic profiles of AApoAII amyloidosis during disease progression and it revealed co-deposition of lipids with AApoAII deposits based on functional analyses. The relative abundance of AApoAII-associated proteins in the amyloid fibril fractions did not change over the course of development of AApoAII amyloidosis pathology. However, their concentrations in plasma changed dramatically with progression of the disease. Interestingly, several AApoAII-associated proteins have been found as constituents of lipid-rich lesions of other degenerative diseases, such as atherosclerosis and age-related macular degeneration. The common protein components among these diseases with lipid-rich deposits could be accounted for by a lipoprotein retention model. Copyright © 2017 Elsevier B.V. All rights reserved.

Anti-inflammatory effects of infliximab in mice are independent of tumour necrosis factor α neutralization.

PubMed

Assas, B M; Levison, S E; Little, M; England, H; Battrick, L; Bagnall, J; McLaughlin, J T; Paszek, P; Else, K J; Pennock, J L

2017-02-01

Infliximab (IFX) has been used repeatedly in mouse preclinical models with associated claims that anti-inflammatory effects are due to inhibition of mouse tumour necrosis factor (TNF)-α. However, the mechanism of action in mice remains unclear. In this study, the binding specificity of IFX for mouse TNF-α was investigated ex vivo using enzyme-linked immunosorbent assay (ELISA), flow cytometry and Western blot. Infliximab (IFX) did not bind directly to soluble or membrane-bound mouse TNF-α nor did it have any effect on TNF-α-induced nuclear factor kappa B (NF-κB) stimulation in mouse fibroblasts. The efficacy of IFX treatment was then investigated in vivo using a TNF-α-independent Trichuris muris-induced infection model of chronic colitis. Infection provoked severe transmural colonic inflammation by day 35 post-infection. Colonic pathology, macrophage phenotype and cell death were determined. As predicted from the in-vitro data, in-vivo treatment of T. muris-infected mice with IFX had no effect on clinical outcome, nor did it affect macrophage cell phenotype or number. IFX enhanced apoptosis of colonic immune cells significantly, likely to be driven by a direct effect of the humanized antibody itself. We have demonstrated that although IFX does not bind directly to TNF-α, observed anti-inflammatory effects in other mouse models may be through host cell apoptosis. We suggest that more careful consideration of xenogeneic responses should be made when utilizing IFX in preclinical models. © 2016 The Authors. Clinical & Experimental Immunology published by John Wiley & Sons Ltd on behalf of British Society for Immunology.

Pathophysiology of the vascular wall and its relevance for cerebrovascular disorders in aged rodents.

PubMed

Popa-Wagner, A; Pirici, D; Petcu, E B; Mogoanta, L; Buga, A-M; Rosen, C L; Leon, R; Huber, J

2010-08-01

Chronic hypertension and cerebral amyloid angiopathy (CAA) are the main pathologies which can induce the rupture of cerebral vessels and intracerebral hemorrhages, as a result of degenerative changes in the vascular wall. A lot of progress has been made in this direction since the successful creation of the first mouse model for the study of Alzheimer's disease (AD), as the spectrum of AD pathology includes a plethora of changes found in pure cerebrovascular diseases. We describe here some of these mouse models having important vascular changes that parallel human AD pathology, and more importantly, we show how these models have helped us understand more about the mechanisms that lead to CAA formation. An important cellular event associated with reduced structural and functional recovery after stroke in aged animals is the early formation of a scar in the infarcted region that impairs subsequent neural recovery and repair. We review recent evidence showing that the rapid formation of the glial scar following stroke in aged rats is associated with premature cellular proliferation that originates primarily from the walls of capillaries in the corpus callosum adjacent to the infarcted region. After stroke several vascular mechanisms are turned-on immediately to protect the brain from further damage and help subsequent neuroregeneration and functional recovery. Although does occur after stroke, vasculogenesis is overshadowed in its protective/restorative role by the angiogenesis and arteriogenesis. Understanding the basic mechanisms underlying functional recovery after cerebral stroke in aging subjects is likely to yield new insights into the treatment of brain injury in the clinic.

Curcumin decreases amyloid-beta peptide levels by attenuating the maturation of amyloid-beta precursor protein.

PubMed

Zhang, Can; Browne, Andrew; Child, Daniel; Tanzi, Rudolph E

2010-09-10

Alzheimer disease (AD) is a devastating neurodegenerative disease with no cure. The pathogenesis of AD is believed to be driven primarily by amyloid-beta (Abeta), the principal component of senile plaques. Abeta is an approximately 4-kDa peptide generated via cleavage of the amyloid-beta precursor protein (APP). Curcumin is a compound in the widely used culinary spice, turmeric, which possesses potent and broad biological activities, including anti-inflammatory and antioxidant activities, chemopreventative effects, and effects on protein trafficking. Recent in vivo studies indicate that curcumin is able to reduce Abeta-related pathology in transgenic AD mouse models via unknown molecular mechanisms. Here, we investigated the effects of curcumin on Abeta levels and APP processing in various cell lines and mouse primary cortical neurons. We show for the first time that curcumin potently lowers Abeta levels by attenuating the maturation of APP in the secretory pathway. These data provide a mechanism of action for the ability of curcumin to attenuate amyloid-beta pathology.

Curcumin Decreases Amyloid-β Peptide Levels by Attenuating the Maturation of Amyloid-β Precursor Protein*

PubMed Central

Zhang, Can; Browne, Andrew; Child, Daniel; Tanzi, Rudolph E.

2010-01-01

Alzheimer disease (AD) is a devastating neurodegenerative disease with no cure. The pathogenesis of AD is believed to be driven primarily by amyloid-β (Aβ), the principal component of senile plaques. Aβ is an ∼4-kDa peptide generated via cleavage of the amyloid-β precursor protein (APP). Curcumin is a compound in the widely used culinary spice, turmeric, which possesses potent and broad biological activities, including anti-inflammatory and antioxidant activities, chemopreventative effects, and effects on protein trafficking. Recent in vivo studies indicate that curcumin is able to reduce Aβ-related pathology in transgenic AD mouse models via unknown molecular mechanisms. Here, we investigated the effects of curcumin on Aβ levels and APP processing in various cell lines and mouse primary cortical neurons. We show for the first time that curcumin potently lowers Aβ levels by attenuating the maturation of APP in the secretory pathway. These data provide a mechanism of action for the ability of curcumin to attenuate amyloid-β pathology. PMID:20622013

Large Polyglutamine Repeats Cause Muscle Degeneration in SCA17 Mice

PubMed Central

Huang, Shanshan; Yang, Su; Guo, Jifeng; Yan, Sen; Gaertig, Marta A.; Li, Shihua; Li, Xiao-Jiang

2015-01-01

SUMMARY In polyglutamine (polyQ) diseases, large polyQ repeats cause juvenile cases with different symptoms than adult-onset patients, who carry smaller expanded polyQ repeats. The mechanisms behind the differential pathology mediated by different polyQ repeat lengths remain unknown. By studying knock-in mouse models of spinal cerebellar ataxia-17 (SCA17), we found that a large polyQ (105 glutamines) in the TATA box-binding protein (TBP) preferentially causes muscle degeneration and reduces the expression of muscle-specific genes. Direct expression of TBP with different polyQ repeats in mouse muscle revealed that muscle degeneration is mediated only by the large polyQ repeats. Different polyQ repeats differentially alter TBP’s interaction with neuronal and muscle-specific transcription factors. As a result, the large polyQ repeat decreases the association of MyoD with TBP and DNA promoters. Our findings suggest that specific alterations in protein interactions by large polyQ repeats may account for the unique pathology in juvenile polyQ diseases. PMID:26387956

Investigation and identification of etiologies involved in the development of acquired hydronephrosis in aged laboratory mice with the use of high-frequency ultrasound imaging

PubMed Central

Springer, Danielle A.; Allen, Michele; Hoffman, Victoria; Brinster, Lauren; Starost, Matthew F.; Bryant, Mark; Eckhaus, Michael

2014-01-01

Laboratory mice develop naturally occurring lesions that affect biomedical research. Hydronephrosis is a recognized pathologic abnormality of the mouse kidney. Acquired hydronephrosis can affect any mouse, as it is caused by any naturally occurring disease that impairs free urine flow. Many etiologies leading to this condition are of particular significance to aging mice. Non-invasive ultrasound imaging detects renal pelvic dilation, renal enlargement, and parenchymal loss for pre-mortem identification of this condition. High-frequency ultrasound transducers produce high-resolution images of small structures, ideal for detecting organ pathology in mice. Using a 40 MHz linear array transducer, we obtained high-resolution images of a diversity of pathologic lesions occurring within the abdomen of seven geriatric mice with acquired hydronephrosis that enabled a determination of the underlying etiology. Etiologies diagnosed from the imaging results include pyelonephritis, neoplasia, urolithiasis, mouse urologic syndrome, and spontaneous hydronephrosis, and were confirmed at necropsy. A retrospective review of abdominal scans from an additional 149 aging mice shows that the most common etiologies associated with acquired hydronephrosis are mouse urologic syndrome and abdominal neoplasia. This report highlights the utility of high-frequency ultrasound for surveying research mice for age-related pathology, and is the first comprehensive report of multiple cases of acquired hydronephrosis in mice. PMID:25143818

A three-dimensional human neural cell culture model of Alzheimer's disease.

PubMed

Choi, Se Hoon; Kim, Young Hye; Hebisch, Matthias; Sliwinski, Christopher; Lee, Seungkyu; D'Avanzo, Carla; Chen, Hechao; Hooli, Basavaraj; Asselin, Caroline; Muffat, Julien; Klee, Justin B; Zhang, Can; Wainger, Brian J; Peitz, Michael; Kovacs, Dora M; Woolf, Clifford J; Wagner, Steven L; Tanzi, Rudolph E; Kim, Doo Yeon

2014-11-13

Alzheimer's disease is the most common form of dementia, characterized by two pathological hallmarks: amyloid-β plaques and neurofibrillary tangles. The amyloid hypothesis of Alzheimer's disease posits that the excessive accumulation of amyloid-β peptide leads to neurofibrillary tangles composed of aggregated hyperphosphorylated tau. However, to date, no single disease model has serially linked these two pathological events using human neuronal cells. Mouse models with familial Alzheimer's disease (FAD) mutations exhibit amyloid-β-induced synaptic and memory deficits but they do not fully recapitulate other key pathological events of Alzheimer's disease, including distinct neurofibrillary tangle pathology. Human neurons derived from Alzheimer's disease patients have shown elevated levels of toxic amyloid-β species and phosphorylated tau but did not demonstrate amyloid-β plaques or neurofibrillary tangles. Here we report that FAD mutations in β-amyloid precursor protein and presenilin 1 are able to induce robust extracellular deposition of amyloid-β, including amyloid-β plaques, in a human neural stem-cell-derived three-dimensional (3D) culture system. More importantly, the 3D-differentiated neuronal cells expressing FAD mutations exhibited high levels of detergent-resistant, silver-positive aggregates of phosphorylated tau in the soma and neurites, as well as filamentous tau, as detected by immunoelectron microscopy. Inhibition of amyloid-β generation with β- or γ-secretase inhibitors not only decreased amyloid-β pathology, but also attenuated tauopathy. We also found that glycogen synthase kinase 3 (GSK3) regulated amyloid-β-mediated tau phosphorylation. We have successfully recapitulated amyloid-β and tau pathology in a single 3D human neural cell culture system. Our unique strategy for recapitulating Alzheimer's disease pathology in a 3D neural cell culture model should also serve to facilitate the development of more precise human neural cell models of other neurodegenerative disorders.

Of von Willebrand factor and platelets.

PubMed

Bryckaert, Marijke; Rosa, Jean-Philippe; Denis, Cécile V; Lenting, Peter J

2015-01-01

Hemostasis and pathological thrombus formation are dynamic processes that require multiple adhesive receptor-ligand interactions, with blood platelets at the heart of such events. Many studies have contributed to shed light on the importance of von Willebrand factor (VWF) interaction with its platelet receptors, glycoprotein (GP) Ib-IX-V and αIIbβ3 integrin, in promoting primary platelet adhesion and aggregation following vessel injury. This review will recapitulate our current knowledge on the subject from the rheological aspect to the spatio-temporal development of thrombus formation. We will also discuss the signaling events generated by VWF/GPIb-IX-V interaction, leading to platelet activation. Additionally, we will review the growing body of evidence gathered from the recent development of pathological mouse models suggesting that VWF binding to GPIb-IX-V is a promising target in arterial and venous pathological thrombosis. Finally, the pathological aspects of VWF and its impact on platelets will be addressed.

The replication of a mouse adapted SARS-CoV in a mouse cell line stably expressing the murine SARS-CoV receptor mACE2 efficiently induces the expression of proinflammatory cytokines.

PubMed

Regla-Nava, Jose A; Jimenez-Guardeño, Jose M; Nieto-Torres, Jose L; Gallagher, Thomas M; Enjuanes, Luis; DeDiego, Marta L

2013-11-01

Infection of conventional mice with a mouse adapted (MA15) severe acute respiratory syndrome (SARS) coronavirus (CoV) reproduces many aspects of human SARS such as pathological changes in lung, viremia, neutrophilia, and lethality. However, established mouse cell lines highly susceptible to mouse-adapted SARS-CoV infection are not available. In this work, efficiently transfectable mouse cell lines stably expressing the murine SARS-CoV receptor angiotensin converting enzyme 2 (ACE2) have been generated. These cells yielded high SARS-CoV-MA15 titers and also served as excellent tools for plaque assays. In addition, in these cell lines, SARS-CoV-MA15 induced the expression of proinflammatory cytokines and IFN-β, mimicking what has been observed in experimental animal models infected with SARS-CoV and SARS patients. These cell lines are valuable tools to perform in vitro studies in a mouse cell system that reflects the species used for in vivo studies of SARS-CoV-MA15 pathogenesis. Copyright © 2013 Elsevier B.V. All rights reserved.

Virulence, pathology, and pathogenesis of Pteropine orthoreovirus (PRV) in BALB/c mice: Development of an animal infection model for PRV.

PubMed

Egawa, Kazutaka; Shimojima, Masayuki; Taniguchi, Satoshi; Nagata, Noriyo; Tani, Hideki; Yoshikawa, Tomoki; Kurosu, Takeshi; Watanabe, Shumpei; Fukushi, Shuetsu; Saijo, Masayuki

2017-12-01

Cases of acute respiratory tract infection caused by Pteropine orthoreovirus (PRV) of the genus Orthoreovirus (family: Reoviridae) have been reported in Southeast Asia, where it was isolated from humans and bats. It is possible that PRV-associated respiratory infections might be prevalent in Southeast Asia. The clinical course of PRV is not fully elucidated. The virulence, pathology, and pathogenesis of two PRV strains, a human-borne PRV strain (isolated from a patient, who returned to Japan from Bali, Indonesia in 2007) and a bat-borne PRV (isolated from a bat [Eonycteris spelaea] in the Philippines in 2013) were investigated in BALB/c mice using virological, pathological, and immunological study methods. The intranasal inoculation of BALB/c mice with human-borne PRV caused respiratory infection. In addition, all mice with immunity induced by pre-inoculation with a non-lethal dose of PRV were completely protected against lethal PRV infection. Mice treated with antiserum with neutralizing antibody activity after inoculation with a lethal dose of PRV showed a reduced fatality rate. In this mouse model, bat-borne PRV caused respiratory infection similar to human-borne PRV. PRV caused lethal respiratory disease in an animal model of PRV infection, in which BALB/c mice were used. The BALB/c mouse model might help to accelerate research on the virulence of PRV and be useful for evaluating the efficacy of therapeutic agents and vaccines for the treatment and prevention of PRV infection. PRV was shown for the first time to be a causative virus of respiratory disease on the basis of Koch's postulations by the additional demonstration that PRV caused respiratory disease in mice through their intranasal inoculation with PRV.

The proof-of-concept of ASS234: Peripherally administered ASS234 enters the central nervous system and reduces pathology in a male mouse model of Alzheimer disease.

PubMed

Serrano, Mari Paz; Herrero-Labrador, Raquel; Futch, Hunter S; Serrano, Julia; Romero, Alejandro; Fernandez, Ana Patricia; Samadi, Abdelouahid; Unzeta, Mercedes; Marco-Contelles, Jose; Martínez-Murillo, Ricardo

2017-01-01

The heterogeneity of Alzheimer disease requires the development of multitarget drugs for treating the symptoms of the disease and its progression. Both cholinergic and monoamine oxidase dysfunctions are involved in the pathological process. Thus, we hypothesized that the development of therapies focused on these targets might be effective. We have developed and assessed a new product, coded ASS234, a multipotent acetyl and butyrylcholinesterase/monoamine oxidase A-B inhibitor with a potent inhibitory effect on amyloid-β aggregation as well as antioxidant and antiapoptotic properties. But there is a need to reliably correlate in vitro and in vivo drug release data. We examined the effect of ASS234 on cognition in healthy adult C57BL/6J mice in a model of scopolamine-induced cognitive impairment that often accompanies normal and pathological aging. Also, in a characterized transgenic APPswe/PS1ΔE9 mouse model of Alzheimer disease, we examined the effects of short-term ASS234 treatment on plaque deposition and gliosis using immunohistochemistry. Toxicology of ASS234 was assessed using a quantitative high-throughput in vitro cytotoxicity screening assay following the MTT assay method in HepG2 liver cells. In vivo, ASS234 significantly decreased scopolamine-induced learning deficits in C57BL/6J mice. Also, reduction of amyloid plaque burden and gliosis in the cortex and hippocampus was assessed. In vitro, ASS234 exhibited lesser toxicity than donepezil and tacrine. The study was conducted in male mice only. Although the Alzheimer disease model does not recapitulate all features of the human disease, it exhibits progressive monoaminergic neurodegeneration. ASS234 is a promising alternative drug of choice to treat the cognitive decline and neurodegeneration underlying Alzheimer disease.

Combined mTOR and MEK inhibition is an effective therapy in a novel mouse model for angiosarcoma

PubMed Central

Chadwick, Michelle L.; Lane, Adam; Thomas, Dana; Smith, Amanda R.; White, Angela R.; Davidson, Dominique; Feng, Yuxin; Boscolo, Elisa; Zheng, Yi; Adams, Denise M.; Gupta, Anita; Veillette, André; Chow, Lionel M.L.

2018-01-01

Angiosarcoma is an aggressive malignancy of vascular origin that occurs de novo or in the context of previous cancer therapy. Despite multi-modal aggressive treatment including surgical resection, chemotherapy, and radiation, five-year overall survival remains poor at 35%. Due to its rarity, little is known about its molecular pathology and clinical trials have been extremely difficult to conduct. Development of animal models for rare diseases like angiosarcoma is critical to improve our understanding of tumorigenesis and to test novel treatment regimens. A genetically engineered mouse model for angiosarcoma was generated by conditional deletion of Trp53, Pten, and Ptpn12 in endothelial cells. Tumors arising from these mice recapitulate the histology and molecular pathology of the human disease including hyperactivation of the PI3K/mTOR and MAPK signaling pathways. Treatment of tumor-bearing mice with mTOR or MEK inhibitors effectively inactivated signaling and resulted in reduced proliferation and elevated apoptosis leading to tumor regression. The effect of treatment on tumor growth was transient and proliferation was restored after a period of dormancy. However, combined inhibition of mTOR and MEK resulted in profound tumor regression which was sustained for the duration of treatment. These results suggest that angiosarcoma may be effectively treated by this drug combination.  PMID:29872503

A Role for the Receptor for Advanced Glycation End Products in Idiopathic Pulmonary Fibrosis

PubMed Central

Englert, Judson M.; Hanford, Lana E.; Kaminski, Naftali; Tobolewski, Jacob M.; Tan, Roderick J.; Fattman, Cheryl L.; Ramsgaard, Lasse; Richards, Thomas J.; Loutaev, Inna; Nawroth, Peter P.; Kasper, Michael; Bierhaus, Angelika; Oury, Tim D.

2008-01-01

Idiopathic pulmonary fibrosis (IPF) is a severely debilitating disease associated with a dismal prognosis. There are currently no effective therapies for IPF, thus the identification of novel therapeutic targets is greatly needed. The receptor for advanced glycation end products (RAGE) is a member of the immunoglobulin superfamily of cell surface receptors whose activation has been linked to various pathologies. In healthy adult animals, RAGE is expressed at the highest levels in the lung compared to other tissues. To investigate the hypothesis that RAGE is involved in IPF pathogenesis, we have examined its expression in two mouse models of pulmonary fibrosis and in human tissue from IPF patients. In each instance we observed a depletion of membrane RAGE and its soluble (decoy) isoform, sRAGE, in fibrotic lungs. In contrast to other diseases in which RAGE signaling promotes pathology, immunohistochemical and hydroxyproline quantification studies on aged RAGE-null mice indicate that these mice spontaneously develop pulmonary fibrosis-like alterations. Furthermore, when subjected to a model of pulmonary fibrosis, RAGE-null mice developed more severe fibrosis, as measured by hydroxyproline assay and histological scoring, than wild-type controls. Combined with data from other studies on mouse models of pulmonary fibrosis and human IPF tissues indicate that loss of RAGE contributes to IPF pathogenesis. PMID:18245812

Intracellular Aß triggers neuron loss in the cholinergic system of the APP/PS1KI mouse model of Alzheimer's disease.

PubMed

Christensen, Ditte Z; Bayer, Thomas A; Wirths, Oliver

2010-07-01

Loss of cholinergic neurons in the Nucleus Basalis of Meynert in Alzheimer's disease (AD) patients was one of the first discoveries of neuron loss in AD. Despite an intense focus on the cholinergic system in AD, the reason for this cholinergic neuron loss is yet unknown. In the present study we examined Abeta-induced pathology and neuron loss in the cholinergic system of the bigenic APP/PS1KI mouse model. Expression of the APP transgene was found in ChAT-positive neurons of motor nuclei accompanied by robust intracellular Abeta accumulation, whereas no APP expressing neurons and thus no intracellular Abeta accumulation were found in neither the forebrain or pons complexes, nor in the caudate putamen. This expression pattern was used as a model system to study the effect of intra- and extracellular Abeta accumulation on neuron loss in the cholinergic system. Stereological quantification revealed a loss of ChAT-positive neurons in APP/PS1KI mice only in the motor nuclei Mo5 and 7N accumulating intracellular Abeta. This study supports the hypothesis of intracellular Abeta accumulation as an early pathological alteration contributing to cell death in AD. Copyright 2008 Elsevier Inc. All rights reserved.

Coexisting cholinergic and parahippocampal degeneration: a key to memory loss in dementia and a challenge for transgenic models?

PubMed

Cassel, Jean-Christophe; Mathis, Chantal; Majchrzak, Monique; Moreau, Pierre-Henri; Dalrymple-Alford, John C

2008-01-01

One century after Alzheimer's initial report, a variety of animal models of Alzheimer's disease (AD) are being used to mimic one or more pathological signs viewed as critical for the evolution of cognitive decline in dementia. Among the most common are, (a) traditional lesion models aimed at reproducing the degeneration of one of two key brain regions affected in AD, namely the cholinergic basal forebrain (CBF) and the transentorhinal region, and (b) transgenic mouse models aimed at reproducing AD histopathological hallmarks, namely amyloid plaques and neurofibrillary tangles. These models have provided valuable insights into the development and consequences of the pathology, but they have not consistently reproduced the severity of memory deficits exhibited in AD. The reasons for this lack of correspondence with the severity of expected deficits may include the limited replication of multiple neuropathology in potentially key brain regions. A recent lesion model in the rat found that severe memory impairment was obtained only when the two traditional lesions were combined together (i.e. conjoint CBF and entorhinal cortex lesions), indicative of a dramatic impact on cognitive function when there is coexisting, rather than isolated, damage in these two brain regions. It is proposed that combining AD transgenic mouse models with additional experimental damage to both the CBF and entorhinal regions might provide a unique opportunity to further understand the evolution of the disease and improve treatments of severe cognitive dysfunction in neurodegenerative dementias. (c) 2008 S. Karger AG, Basel

Absence of Prenatal Forebrain Defects in the Dp(16)1Yey/+ Mouse Model of Down Syndrome

PubMed Central

Goodliffe, Joseph W.; Olmos-Serrano, Jose Luis; Aziz, Nadine M.; Pennings, Jeroen L.A.; Guedj, Faycal; Bianchi, Diana W.

2016-01-01

Studies in humans with Down syndrome (DS) show that alterations in fetal brain development are followed by postnatal deficits in neuronal numbers, synaptic plasticity, and cognitive and motor function. This same progression is replicated in several mouse models of DS. Dp(16)1Yey/+ (hereafter called Dp16) is a recently developed mouse model of DS in which the entire region of mouse chromosome 16 that is homologous to human chromosome 21 has been triplicated. As such, Dp16 mice may more closely reproduce neurodevelopmental changes occurring in humans with DS. Here, we present the first comprehensive cellular and behavioral study of the Dp16 forebrain from embryonic to adult stages. Unexpectedly, our results demonstrate that Dp16 mice do not have prenatal brain defects previously reported in human fetal neocortex and in the developing forebrains of other mouse models, including microcephaly, reduced neurogenesis, and abnormal cell proliferation. Nevertheless, we found impairments in postnatal developmental milestones, fewer inhibitory forebrain neurons, and deficits in motor and cognitive performance in Dp16 mice. Therefore, although this new model does not express prenatal morphological phenotypes associated with DS, abnormalities in the postnatal period appear sufficient to produce significant cognitive deficits in Dp16. SIGNIFICANCE STATEMENT Down syndrome (DS) leads to intellectual disability. Several mouse models have increased our understanding of the neuropathology of DS and are currently being used to test therapeutic strategies. A new mouse model that contains an expanded number of DS-related genes, known as Dp(16)1Yey/+ (Dp16), has been generated recently. We sought to determine whether the extended triplication creates a better phenocopy of DS-related brain pathologies. We measured embryonic development, forebrain maturation, and perinatal/adult behavior and revealed an absence of prenatal phenotypes in Dp16 fetal brain, but specific cellular and behavioral deficits after the first 2 postnatal weeks. These results uncover important differences in prenatal phenotype between Dp16 animals and humans with DS and other DS mouse models. PMID:26961948

Altered Intrinsic Pyramidal Neuron Properties and Pathway-Specific Synaptic Dysfunction Underlie Aberrant Hippocampal Network Function in a Mouse Model of Tauopathy

PubMed Central

Booth, Clair A.; Witton, Jonathan; Nowacki, Jakub; Tsaneva-Atanasova, Krasimira; Jones, Matthew W.; Randall, Andrew D.

2016-01-01

The formation and deposition of tau protein aggregates is proposed to contribute to cognitive impairments in dementia by disrupting neuronal function in brain regions, including the hippocampus. We used a battery of in vivo and in vitro electrophysiological recordings in the rTg4510 transgenic mouse model, which overexpresses a mutant form of human tau protein, to investigate the effects of tau pathology on hippocampal neuronal function in area CA1 of 7- to 8-month-old mice, an age point at which rTg4510 animals exhibit advanced tau pathology and progressive neurodegeneration. In vitro recordings revealed shifted theta-frequency resonance properties of CA1 pyramidal neurons, deficits in synaptic transmission at Schaffer collateral synapses, and blunted plasticity and imbalanced inhibition at temporoammonic synapses. These changes were associated with aberrant CA1 network oscillations, pyramidal neuron bursting, and spatial information coding in vivo. Our findings relate tauopathy-associated changes in cellular neurophysiology to altered behavior-dependent network function. SIGNIFICANCE STATEMENT Dementia is characterized by the loss of learning and memory ability. The deposition of tau protein aggregates in the brain is a pathological hallmark of dementia; and the hippocampus, a brain structure known to be critical in processing learning and memory, is one of the first and most heavily affected regions. Our results show that, in area CA1 of hippocampus, a region involved in spatial learning and memory, tau pathology is associated with specific disturbances in synaptic, cellular, and network-level function, culminating in the aberrant encoding of spatial information and spatial memory impairment. These studies identify several novel ways in which hippocampal information processing may be disrupted in dementia, which may provide targets for future therapeutic intervention. PMID:26758828

A novel GLP-1/GIP/Gcg triagonist reduces cognitive deficits and pathology in the 3xTg mouse model of Alzheimer's disease.

PubMed

Li, Tian; Jiao, Juan-Juan; Hölscher, Christian; Wu, Mei-Na; Zhang, Jun; Tong, Jia-Qing; Dong, Xue-Fan; Qu, Xue-Song; Cao, Yue; Cai, Hong-Yan; Su, Qiang; Qi, Jin-Shun

2018-05-01

Type 2 diabetes mellitus (T2DM) is an important risk factor for Alzheimer's disease (AD). Glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) have been identified to be effective in T2DM treatment and neuroprotection. In this study, we further explored the effects of a novel unimolecular GLP-1/GIP/Gcg triagonist on the cognitive behavior and cerebral pathology in the 7-month-old triple transgenic mouse model of AD (3xTg-AD), and investigated its possible electrophysiological and molecular mechanisms. After chronic administration of the GLP-1/GIP/Gcg triagonist (10 nmol/kg bodyweight, once daily, i.p.) for 30 days, open field, Y maze and Morris water maze tests were performed, followed by in vivo electrophysiological recording, immunofluorescence and Western blotting experiments. We found that the chronic treatment with the triagonist could improve long-term spatial memory of 3xTg-AD mice in Morris water maze, as well as the working memory in Y maze task. The triagonist also alleviated the suppression of long-term potentiation (LTP) in the CA1 region of hippocampus. In addition, the triagonist significantly reduced hippocampal pathological damages, including amyloid-β (Aβ) and phosphorylated tau aggregates, and upregulated the expression levels of S133 p-CREB, T286 p-CAMKII and S9 p-GSK3β in the hippocampus of the 3xTg-AD mice. These results demonstrate for the first time that the novel GLP-1/GIP/Gcg triagonist is efficacious in ameliorating cognitive deficits and pathological damages of 3xTg-AD mice, suggesting that the triagonist might be potentially beneficial in the treatment of AD. © 2018 Wiley Periodicals, Inc.

Altered Intrinsic Pyramidal Neuron Properties and Pathway-Specific Synaptic Dysfunction Underlie Aberrant Hippocampal Network Function in a Mouse Model of Tauopathy.

PubMed

Booth, Clair A; Witton, Jonathan; Nowacki, Jakub; Tsaneva-Atanasova, Krasimira; Jones, Matthew W; Randall, Andrew D; Brown, Jonathan T

2016-01-13

The formation and deposition of tau protein aggregates is proposed to contribute to cognitive impairments in dementia by disrupting neuronal function in brain regions, including the hippocampus. We used a battery of in vivo and in vitro electrophysiological recordings in the rTg4510 transgenic mouse model, which overexpresses a mutant form of human tau protein, to investigate the effects of tau pathology on hippocampal neuronal function in area CA1 of 7- to 8-month-old mice, an age point at which rTg4510 animals exhibit advanced tau pathology and progressive neurodegeneration. In vitro recordings revealed shifted theta-frequency resonance properties of CA1 pyramidal neurons, deficits in synaptic transmission at Schaffer collateral synapses, and blunted plasticity and imbalanced inhibition at temporoammonic synapses. These changes were associated with aberrant CA1 network oscillations, pyramidal neuron bursting, and spatial information coding in vivo. Our findings relate tauopathy-associated changes in cellular neurophysiology to altered behavior-dependent network function. Dementia is characterized by the loss of learning and memory ability. The deposition of tau protein aggregates in the brain is a pathological hallmark of dementia; and the hippocampus, a brain structure known to be critical in processing learning and memory, is one of the first and most heavily affected regions. Our results show that, in area CA1 of hippocampus, a region involved in spatial learning and memory, tau pathology is associated with specific disturbances in synaptic, cellular, and network-level function, culminating in the aberrant encoding of spatial information and spatial memory impairment. These studies identify several novel ways in which hippocampal information processing may be disrupted in dementia, which may provide targets for future therapeutic intervention. Copyright © 2016 Booth, Witton et al.

An operant-based detection method for inferring tinnitus in mice.

PubMed

Zuo, Hongyan; Lei, Debin; Sivaramakrishnan, Shobhana; Howie, Benjamin; Mulvany, Jessica; Bao, Jianxin

2017-11-01

Subjective tinnitus is a hearing disorder in which a person perceives sound when no external sound is present. It can be acute or chronic. Because our current understanding of its pathology is incomplete, no effective cures have yet been established. Mouse models are useful for studying the pathophysiology of tinnitus as well as for developing therapeutic treatments. We have developed a new method for determining acute and chronic tinnitus in mice, called sound-based avoidance detection (SBAD). The SBAD method utilizes one paradigm to detect tinnitus and another paradigm to monitor possible confounding factors, such as motor impairment, loss of motivation, and deficits in learning and memory. The SBAD method has succeeded in monitoring both acute and chronic tinnitus in mice. Its detection ability is further validated by functional studies demonstrating an abnormal increase in neuronal activity in the inferior colliculus of mice that had previously been identified as having tinnitus by the SBAD method. The SBAD method provides a new means by which investigators can detect tinnitus in a single mouse accurately and with more control over potential confounding factors than existing methods. This work establishes a new behavioral method for detecting tinnitus in mice. The detection outcome is consistent with functional validation. One key advantage of mouse models is they provide researchers the opportunity to utilize an extensive array of genetic tools. This new method could lead to a deeper understanding of the molecular pathways underlying tinnitus pathology. Copyright © 2017 Elsevier B.V. All rights reserved.

Intranasal Insulin Prevents Cognitive Decline, Cerebral Atrophy and White Matter Changes in Murine Type I Diabetic Encephalopathy

ERIC Educational Resources Information Center

Francis, George J.; Martinez, Jose A.; Liu, Wei Q.; Xu, Kevin; Ayer, Amit; Fine, Jared; Tuor, Ursula I.; Glazner, Gordon; Hanson, Leah R.; Frey, William H., II; Toth, Cory

2008-01-01

Insulin deficiency in type I diabetes may lead to cognitive impairment, cerebral atrophy and white matter abnormalities. We studied the impact of a novel delivery system using intranasal insulin (I-I) in a mouse model of type I diabetes (streptozotocin-induced) for direct targeting of pathological and cognitive deficits while avoiding potential…

A mouse model for creatine transporter deficiency reveals early onset cognitive impairment and neuropathology associated with brain aging.

PubMed

Baroncelli, Laura; Molinaro, Angelo; Cacciante, Francesco; Alessandrì, Maria Grazia; Napoli, Debora; Putignano, Elena; Tola, Jonida; Leuzzi, Vincenzo; Cioni, Giovanni; Pizzorusso, Tommaso

2016-10-01

Mutations in the creatine (Cr) transporter (CrT) gene lead to cerebral creatine deficiency syndrome-1 (CCDS1), an X-linked metabolic disorder characterized by cerebral Cr deficiency causing intellectual disability, seizures, movement and autistic-like behavioural disturbances, language and speech impairment. Since no data are available about the neural and molecular underpinnings of this disease, we performed a longitudinal analysis of behavioural and pathological alterations associated with CrT deficiency in a CCDS1 mouse model. We found precocious cognitive and autistic-like defects, mimicking the early key features of human CCDS1. Moreover, mutant mice displayed a progressive impairment of short and long-term declarative memory denoting an early brain aging. Pathological examination showed a prominent loss of GABAergic synapses, marked activation of microglia, reduction of hippocampal neurogenesis and the accumulation of autofluorescent lipofuscin. Our data suggest that brain Cr depletion causes both early intellectual disability and late progressive cognitive decline, and identify novel targets to design intervention strategies aimed at overcoming brain CCDS1 alterations. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Therapeutic effects of remediating autophagy failure in a mouse model of Alzheimer disease by enhancing lysosomal proteolysis.

PubMed

Yang, Dun-Sheng; Stavrides, Philip; Mohan, Panaiyur S; Kaushik, Susmita; Kumar, Asok; Ohno, Masuo; Schmidt, Stephen D; Wesson, Daniel W; Bandyopadhyay, Urmi; Jiang, Ying; Pawlik, Monika; Peterhoff, Corrinne M; Yang, Austin J; Wilson, Donald A; St George-Hyslop, Peter; Westaway, David; Mathews, Paul M; Levy, Efrat; Cuervo, Ana M; Nixon, Ralph A

2011-07-01

The extensive autophagic-lysosomal pathology in Alzheimer disease (AD) brain has revealed a major defect: in the proteolytic clearance of autophagy substrates. Autophagy failure contributes on several levels to AD pathogenesis and has become an important therapeutic target for AD and other neurodegenerative diseases. We recently observed broad therapeutic effects of stimulating autophagic-lysosomal proteolysis in the TgCRND8 mouse model of AD that exhibits defective proteolytic clearance of autophagic substrates, robust intralysosomal amyloid-β peptide (Aβ) accumulation, extracellular β-amyloid deposition and cognitive deficits. By genetically deleting the lysosomal cysteine protease inhibitor, cystatin B (CstB), to selectively restore depressed cathepsin activities, we substantially cleared Aβ, ubiquitinated proteins and other autophagic substrates from autolysosomes/lysosomes and rescued autophagic-lysosomal pathology, as well as reduced total Aβ40/42 levels and extracellular amyloid deposition, highlighting the underappreciated importance of the lysosomal system for Aβ clearance. Most importantly, lysosomal remediation prevented the marked learning and memory deficits in TgCRND8 mice. Our findings underscore the pathogenic significance of autophagic-lysosomal dysfunction in AD and demonstrate the value of reversing this dysfunction as an innovative therapeautic strategy for AD.

rAAV Gene Therapy in a Canavan's Disease Mouse Model Reveals Immune Impairments and an Extended Pathology Beyond the Central Nervous System.

PubMed

Ahmed, Seemin Seher; Schattgen, Stefan A; Frakes, Ashley E; Sikoglu, Elif M; Su, Qin; Li, Jia; Hampton, Thomas G; Denninger, Andrew R; Kirschner, Daniel A; Kaspar, Brian; Matalon, Reuben; Gao, Guangping

2016-06-01

Aspartoacylase (AspA) gene mutations cause the pediatric lethal neurodegenerative Canavan disease (CD). There is emerging promise of successful gene therapy for CD using recombinant adeno-associated viruses (rAAVs). Here, we report an intracerebroventricularly delivered AspA gene therapy regime using three serotypes of rAAVs at a 20-fold reduced dose than previously described in AspA(-/-) mice, a bona-fide mouse model of CD. Interestingly, central nervous system (CNS)-restricted therapy prolonged survival over systemic therapy in CD mice but failed to sustain motor functions seen in systemically treated mice. Importantly, we reveal through histological and functional examination of untreated CD mice that AspA deficiency in peripheral tissues causes morphological and functional abnormalities in this heretofore CNS-defined disorder. We demonstrate for the first time that AspA deficiency, possibly through excessive N-acetyl aspartic acid accumulation, elicits both a peripheral and CNS immune response in CD mice. Our data establish a role for peripheral tissues in CD pathology and serve to aid the development of more efficacious and sustained gene therapy for this disease.

18F-FDG PET imaging for identifying the dynamics of intestinal disease caused by SFTSV infection in a mouse model.

PubMed

Hayasaka, Daisuke; Nishi, Kodai; Fuchigami, Takeshi; Shiogama, Kazuya; Onouchi, Takanori; Shimada, Satoshi; Tsutsumi, Yutaka; Morita, Kouichi

2016-01-05

Severe fever with thrombocytopenia syndrome (SFTS) is an emerging disease that causes fever, enteritis, thrombocytopenia, and leucopenia and can be fatal in up to 30% of cases. However, the mechanism of severe disease is not fully understood. Molecular imaging approaches, such as positron-emission tomography (PET), are functional in vivo imaging techniques that provide real-time dynamics of disease progression, assessments of pharmacokinetics, and diagnoses for disease progression. Molecular imaging also potentially provides useful approaches to explore the pathogenesis of viral infections. Thus, the purpose of this study was to image the pathological features of SFTSV infection in vivo by PET imaging. In a mouse model, we showed that 18F-FDG accumulations clearly identified the intestinal tract site as a pathological site. We also demonstrated that 18F-FDG PET imaging can assess disease progression and response to antiserum therapy within the same individual. This is the first report demonstrating a molecular imaging strategy for SFTSV infection. Our results provide potentially useful information for preclinical studies such as the elucidation of the mechanism of SFTSV infection in vivo and the assessment of drugs for SFTS treatment.

RNase H2 catalytic core Aicardi-Goutières syndrome–related mutant invokes cGAS–STING innate immune-sensing pathway in mice

PubMed Central

Pokatayev, Vladislav; Hasin, Naushaba; Chon, Hyongi; Cerritelli, Susana M.; Sakhuja, Kiran; Ward, Jerrold M.; Morris, H. Douglas; Yan, Nan

2016-01-01

The neuroinflammatory autoimmune disease Aicardi-Goutières syndrome (AGS) develops from mutations in genes encoding several nucleotide-processing proteins, including RNase H2. Defective RNase H2 may induce accumulation of self-nucleic acid species that trigger chronic type I interferon and inflammatory responses, leading to AGS pathology. We created a knock-in mouse model with an RNase H2 AGS mutation in a highly conserved residue of the catalytic subunit, Rnaseh2aG37S/G37S (G37S), to understand disease pathology. G37S homozygotes are perinatal lethal, in contrast to the early embryonic lethality previously reported for Rnaseh2b- or Rnaseh2c-null mice. Importantly, we found that the G37S mutation led to increased expression of interferon-stimulated genes dependent on the cGAS–STING signaling pathway. Ablation of STING in the G37S mice results in partial rescue of the perinatal lethality, with viable mice exhibiting white spotting on their ventral surface. We believe that the G37S knock-in mouse provides an excellent animal model for studying RNASEH2-associated autoimmune diseases. PMID:26880576

A mouse model with postnatal endolymphatic hydrops and hearing loss

PubMed Central

Megerian, Cliff A.; Semaan, Maroun T.; Aftab, Saba; Kisley, Lauren B.; Zheng, Qing Yin; Pawlowski, Karen S.; Wright, Charles G.; Alagramam, Kumar N.

2010-01-01

Endolymphatic hydrops (ELH), hearing loss and neuronal degeneration occur together in a variety of clinically significant disorders, including Meniere’s disease (MD). However, the sequence of these pathological changes and their relationship to each other are not well understood. In this regard, an animal model that spontaneously develops these features postnatally would be useful for research purposes. A search for such a model led us to the PhexHyp-Duk mouse, a mutant allele of the Phex gene causing X-linked hypophosphatemic rickets. The hemizygous male (PhexHyp-Duk/Y) was previously reported to exhibit various abnormalities during adulthood, including thickening of bone, ELH and hearing loss. The reported inner-ear phenotype was suggestive of progressive pathology and spontaneous development of ELH postnatally, but not conclusive. The main focuses of this report are to further characterize the inner ear phenotype in PhexHyp-Duk/Y mice and to test the hypotheses that (a) the PhexHyp-Duk/Y mouse develops ELH and hearing loss postnatally, and (b) the development of ELH in the PhexHyp-Duk/Y mouse is associated with obstruction of the endolymphatic duct (ED) due to thickening of the surrounding bone. Auditory brainstem response (ABR) recordings at various times points and histological analysis of representative temporal bones reveal that PhexHyp-Duk/Y mice typically develop adult onset, asymmetric, progressive hearing loss closely followed by the onset of ELH. ABR and histological data show that functional degeneration precedes structural degeneration. The major degenerative correlate of hearing loss and ELH in the mutants is the primary loss of spiral ganglion cells. Further, PhexHyp-Duk/Y mice develop ELH without evidence of ED obstruction, supporting the idea that ELH can be induced by a mechanism other than the blockade of longitudinal flow of endolymphatic fluid, and occlusion of ED is not a prerequisite for the development of ELH in patients. PMID:18289812

Patterns of Invasive Growth in Malignant Gliomas-The Hippocampus Emerges as an Invasion-Spared Brain Region.

PubMed

Mughal, Awais A; Zhang, Lili; Fayzullin, Artem; Server, Andres; Li, Yuping; Wu, Yingxi; Glass, Rainer; Meling, Torstein; Langmoen, Iver A; Leergaard, Trygve B; Vik-Mo, Einar O

2018-05-21

Widespread infiltration of tumor cells into surrounding brain parenchyma is a hallmark of malignant gliomas, but little data exist on the overall invasion pattern of tumor cells throughout the brain. We have studied the invasive phenotype of malignant gliomas in two invasive mouse models and patients. Tumor invasion patterns were characterized in a patient-derived xenograft mouse model using brain-wide histological analysis and magnetic resonance (MR) imaging. Findings were histologically validated in a cdkn2a-/- PDGF-β lentivirus-induced mouse glioblastoma model. Clinical verification of the results was obtained by analysis of MR images of malignant gliomas. Histological analysis using human-specific cellular markers revealed invasive tumors with a non-radial invasion pattern. Tumors cells accumulated in structures located far from the transplant site, such as the optic white matter and pons, whereas certain adjacent regions were spared. As such, the hippocampus was remarkably free of infiltrating tumor cells despite the extensive invasion of surrounding regions. Similarly, MR images of xenografted mouse brains displayed tumors with bihemispheric pathology, while the hippocampi appeared relatively normal. In patients, most malignant temporal lobe gliomas were located lateral to the collateral sulcus. Despite widespread pathological fluid-attenuated inversion recovery signal in the temporal lobe, 74% of the "lateral tumors" did not show signs of involvement of the amygdalo-hippocampal complex. Our data provide clear evidence for a compartmental pattern of invasive growth in malignant gliomas. The observed invasion patterns suggest the presence of preferred migratory paths, as well as intra-parenchymal boundaries that may be difficult for glioma cells to traverse supporting the notion of compartmental growth. In both mice and human patients, the hippocampus appears to be a brain region that is less prone to tumor invasion. Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.

Sex-related alterations of gut microbiota composition in the BTBR mouse model of autism spectrum disorder

PubMed Central

Coretti, Lorena; Cristiano, Claudia; Florio, Ermanno; Scala, Giovanni; Lama, Adriano; Keller, Simona; Cuomo, Mariella; Russo, Roberto; Pero, Raffaela; Paciello, Orlando; Mattace Raso, Giuseppina; Meli, Rosaria; Cocozza, Sergio; Calignano, Antonio; Chiariotti, Lorenzo; Lembo, Francesca

2017-01-01

Alterations of microbiota-gut-brain axis have been invoked in the pathogenesis of autism spectrum disorders (ASD). Mouse models could represent an excellent tool to understand how gut dysbiosis and related alterations may contribute to autistic phenotype. In this study we paralleled gut microbiota (GM) profiles, behavioral characteristics, intestinal integrity and immunological features of colon tissues in BTBR T + tf/J (BTBR) inbred mice, a well established animal model of ASD. Sex differences, up to date poorly investigated in animal models, were specifically addressed. Results showed that BTBR mice of both sexes presented a marked intestinal dysbiosis, alterations of behavior, gut permeability and immunological state with respect to prosocial C57BL/6j (C57) strain. Noticeably, sex-related differences were clearly detected. We identified Bacteroides, Parabacteroides, Sutterella, Dehalobacterium and Oscillospira genera as key drivers of sex-specific gut microbiota profiles associated with selected pathological traits. Taken together, our findings indicate that alteration of GM in BTBR mice shows relevant sex-associated differences and supports the use of BTBR mouse model to dissect autism associated microbiota-gut-brain axis alteration. PMID:28349974

Endothelial TWIST1 Promotes Pathological Ocular Angiogenesis

PubMed Central

Li, Jie; Liu, Chi-Hsiu; Sun, Ye; Gong, Yan; Fu, Zhongjie; Evans, Lucy P.; Tian, Katherine T.; Juan, Aimee M.; Hurst, Christian G.; Mammoto, Akiko; Chen, Jing

2014-01-01

Purpose. Pathological neovessel formation impacts many blinding vascular eye diseases. Identification of molecular signatures distinguishing pathological neovascularization from normal quiescent vessels is critical for developing new interventions. Twist-related protein 1 (TWIST1) is a transcription factor important in tumor and pulmonary angiogenesis. This study investigated the potential role of TWIST1 in modulating pathological ocular angiogenesis in mice. Methods. Twist1 expression and localization were analyzed in a mouse model of oxygen-induced retinopathy (OIR). Pathological ocular angiogenesis in Tie2-driven conditional Twist1 knockout mice were evaluated in both OIR and laser-induced choroidal neovascularization models. In addition, the effects of TWIST1 on angiogenesis and endothelial cell function were analyzed in sprouting assays of aortic rings and choroidal explants isolated from Twist1 knockout mice, and in human retinal microvascular endothelial cells treated with TWIST1 small interfering RNA (siRNA). Results. TWIST1 is highly enriched in pathological neovessels in OIR retinas. Conditional Tie2-driven depletion of Twist1 significantly suppressed pathological neovessels in OIR without impacting developmental retinal angiogenesis. In a laser-induced choroidal neovascularization model, Twist1 deficiency also resulted in significantly smaller lesions with decreased vascular leakage. In addition, loss of Twist1 significantly decreased vascular sprouting in both aortic ring and choroid explants. Knockdown of TWIST1 in endothelial cells led to dampened expression of vascular endothelial growth factor receptor 2 (VEGFR2) and decreased endothelial cell proliferation. Conclusions. Our study suggests that TWIST1 is a novel regulator of pathologic ocular angiogenesis and may represent a new molecular target for developing potential therapeutic treatments to suppress pathological neovascularization in vascular eye diseases. PMID:25414194

Spatial reversal learning defect coincides with hypersynchronous telencephalic BOLD functional connectivity in APPNL-F/NL-F knock-in mice.

PubMed

Shah, Disha; Latif-Hernandez, Amira; De Strooper, Bart; Saito, Takashi; Saido, Takaomi; Verhoye, Marleen; D'Hooge, Rudi; Van der Linden, Annemie

2018-04-19

Amyloid pathology occurs early in Alzheimer's disease (AD), and has therefore been the focus of numerous studies. Transgenic mouse models have been instrumental to study amyloidosis, but observations might have been confounded by APP-overexpression artifacts. The current study investigated early functional defects in an APP knock-in mouse model, which allows assessing the effects of pathological amyloid-beta (Aβ) without interference of APP-artifacts. Female APP NL/NL knock-in mice of 3 and 7 months old were compared to age-matched APP NL-F/NL-F mice with increased Aβ42/40 ratio and initial Aβ-plaque deposition around 6 months of age. Spatial learning was examined using a Morris water maze protocol consisting of acquisition and reversal trials interleaved with reference memory tests. Functional connectivity (FC) of brain networks was assessed using resting-state functional MRI (rsfMRI). The Morris water maze data revealed that 3 months old APP NL-F/NL-F mice were unable to reach the same reference memory proficiency as APP NL/NL mice after reversal training. This cognitive defect in 3-month-old APP NL-F/NL-F mice coincided with hypersynchronous FC of the hippocampal, cingulate, caudate-putamen, and default-mode-like networks. The occurrence of these defects in APP NL-F/NL-F mice demonstrates that cognitive flexibility and synchronicity of telencephalic activity are specifically altered by early Aβ pathology without changes in APP neurochemistry.

Systemic Central Nervous System (CNS)-targeted Delivery of Neuropeptide Y (NPY) Reduces Neurodegeneration and Increases Neural Precursor Cell Proliferation in a Mouse Model of Alzheimer Disease.

PubMed

Spencer, Brian; Potkar, Rewati; Metcalf, Jeff; Thrin, Ivy; Adame, Anthony; Rockenstein, Edward; Masliah, Eliezer

2016-01-22

Neuropeptide Y (NPY) is one of the most abundant protein transmitters in the central nervous system with roles in a variety of biological functions including: food intake, cardiovascular regulation, cognition, seizure activity, circadian rhythms, and neurogenesis. Reduced NPY and NPY receptor expression is associated with numerous neurodegenerative disorders including Alzheimer disease (AD). To determine whether replacement of NPY could ameliorate some of the neurodegenerative and behavioral pathology associated with AD, we generated a lentiviral vector expressing NPY fused to a brain transport peptide (apoB) for widespread CNS delivery in an APP-transgenic (tg) mouse model of AD. The recombinant NPY-apoB effectively reversed neurodegenerative pathology and behavioral deficits although it had no effect on accumulation of Aβ. The subgranular zone of the hippocampus showed a significant increase in proliferation of neural precursor cells without further differentiation into neurons. The neuroprotective and neurogenic effects of NPY-apoB appeared to involve signaling via ERK and Akt through the NPY R1 and NPY R2 receptors. Thus, widespread CNS-targeted delivery of NPY appears to be effective at reversing the neuronal and glial pathology associated with Aβ accumulation while also increasing NPC proliferation. Overall, increased delivery of NPY to the CNS for AD might be an effective therapy especially if combined with an anti-Aβ therapeutic. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

Vascular and parenchymal amyloid pathology in an Alzheimer disease knock-in mouse model: interplay with cerebral blood flow.

PubMed

Li, Hongmei; Guo, Qinxi; Inoue, Taeko; Polito, Vinicia A; Tabuchi, Katsuhiko; Hammer, Robert E; Pautler, Robia G; Taffet, George E; Zheng, Hui

2014-08-09

Accumulation and deposition of β-amyloid peptides (Aβ) in the brain is a central event in the pathogenesis of Alzheimer's disease (AD). Besides the parenchymal pathology, Aβ is known to undergo active transport across the blood-brain barrier and cerebral amyloid angiopathy (CAA) is a prominent feature in the majority of AD. Although impaired cerebral blood flow (CBF) has been implicated in faulty Aβ transport and clearance, and cerebral hypoperfusion can exist in the pre-clinical phase of Alzheimer's disease (AD), it is still unclear whether it is one of the causal factors for AD pathogenesis, or an early consequence of a multi-factor condition that would lead to AD at late stage. To study the potential interaction between faulty CBF and amyloid accumulation in clinical-relevant situation, we generated a new amyloid precursor protein (APP) knock-in allele that expresses humanized Aβ and a Dutch mutation in addition to Swedish/London mutations and compared this line with an equivalent knock-in line but in the absence of the Dutch mutation, both crossed onto the PS1M146V knock-in background. Introduction of the Dutch mutation results in robust CAA and parenchymal Aβ pathology, age-dependent reduction of spatial learning and memory deficits, and CBF reduction as detected by fMRI. Direct manipulation of CBF by transverse aortic constriction surgery on the left common carotid artery caused differential changes in CBF in the anterior and middle region of the cortex, where it is reduced on the left side and increased on the right side. However these perturbations in CBF resulted in the same effect: both significantly exacerbate CAA and amyloid pathology. Our study reveals a direct and positive link between vascular and parenchymal Aβ; both can be modulated by CBF. The new APP knock-in mouse model recapitulates many symptoms of AD including progressive vascular and parenchymal Aβ pathology and behavioral deficits in the absence of APP overexpression.

Metabolic changes over the course of aging in a mouse model of tau deposition

PubMed Central

Joly-Amado, Aurélie; Serraneau, Karisa S.; Brownlow, Milene; Marín de Evsikova, Caralina; Speakman, John R.; Gordon, Marcia N.; Morgan, Dave

2016-01-01

Weight loss and food intake disturbances that often precede cognitive decline and diagnosis have been extensively reported in Alzheimer’s disease patients. Previously, we observed that transgenic mice overexpressing tau seemed to eat more food, yet weigh less than non-transgenic littermates. Thus the present longitudinal study measured the time course of changes in metabolic state over the lifespan of the tau depositing Tg4510 mouse model of tau deposition. Although body weight was comparable to non-transgenic littermates at 2 months of age, Tg4510 mice weighed less at older ages. This was accompanied by the accumulation of tau pathology and by dramatically increased activity in all phases of the 24-hour cycle. Resting metabolic rate was also increased at 7 months of age. At 12 months near the end of the Tg4510 lifespan, there was a wasting phase, with a considerable decrease of resting metabolic rate, although hyperactivity was maintained. These diverse changes in metabolism in a mouse model of tau deposition are discussed in the context of known changes in energy metabolism in Alzheimer’s disease. PMID:27318134

Adult Mouse DRG Explant and Dissociated Cell Models to Investigate Neuroplasticity and Responses to Environmental Insults Including Viral Infection.

PubMed

Fornaro, Michele; Sharthiya, Harsh; Tiwari, Vaibhav

2018-03-09

This protocol describes an ex vivo model of mouse-derived dorsal root ganglia (DRG) explant and in vitro DRG-derived co-culture of dissociated sensory neurons and glial satellite cells. These are useful and versatile models to investigate a variety of biological responses associated with physiological and pathological conditions of the peripheral nervous system (PNS) ranging from neuron-glial interaction, neuroplasticity, neuroinflammation, and viral infection. The usage of DRG explant is scientifically advantageous compared to simplistic single cells models for multiple reasons. For instance, as an organotypic culture, the DRG explant allows ex vivo transfer of an entire neuronal network including the extracellular microenvironment that play a significant role in all the neuronal and glial functions. Further, DRG explants can also be maintained ex vivo for several days and the culture conditions can be perturbed as desired. In addition, the harvested DRG can be further dissociated into an in vitro co-culture of primary sensory neurons and satellite glial cells to investigate neuronal-glial interaction, neuritogenesis, axonal cone interaction with the extracellular microenvironment, and more general, any aspect associated with the neuronal metabolism. Therefore, the DRG-explant system offers a great deal of flexibility to study a wide array of events related to biological, physiological, and pathological conditions in a cost-effective manner.

In-depth behavioral characterization of the corticosterone mouse model and the critical involvement of housing conditions.

PubMed

Demuyser, Thomas; Deneyer, Lauren; Bentea, Eduard; Albertini, Giulia; Van Liefferinge, Joeri; Merckx, Ellen; De Prins, An; De Bundel, Dimitri; Massie, Ann; Smolders, Ilse

2016-03-15

Depression and anxiety are disabling and highly prevalent psychiatric disorders. To better understand the neurobiological basis of mood and anxiety disorders, relevant animal models are needed. The corticosterone mouse model is frequently used to study depression. Chronic stress and accompanying glucocorticoid elevation causes pathological changes in the central nervous system, which are related to psychiatric symptoms. Exogenous administration of corticosterone is therefore often used to induce depressive-like behavior in mice and in some cases also features of anxiety-like behavior are shown. However, a thorough characterization of this model has never been conducted and housing conditions of the used subjects often differ between the implemented protocols. We chronically administered a subcutaneous corticosterone bolus injection to single- and group-housed mice, and we subsequently evaluated the face validity of this model by performing a battery of behavioral tests (forced swim test, mouse-tail suspension test, saccharin intake test, novelty-suppressed feeding test, elevated plus maze, light/dark paradigm and open field test). Our results show that corticosterone treatment has a substantial overall effect on depressive-like behavior. Increases in anxiety-like behavior on the other hand are mainly seen in single housed animals, independent of treatment. The current study therefore does not only show a detailed behavioral characterization of the corticosterone mouse model, but furthermore also elucidates the critical influence of housing conditions on the behavioral outcome in this model. Copyright © 2015 Elsevier Inc. All rights reserved.

A composite mouse model of aplastic anemia complicated with iron overload

PubMed Central

Wu, Dijiong; Wen, Xiaowen; Liu, Wenbin; Xu, Linlong; Ye, Baodong; Zhou, Yuhong

2018-01-01

Iron overload is commonly encountered during the course of aplastic anemia (AA), but no composite animal model has been developed yet, which hinders drug research. In the present study, the optimal dosage and duration of intraperitoneal iron dextran injection for the development of an iron overload model in mice were explored. A composite model of AA was successfully established on the principle of immune-mediated bone marrow failure. Liver volume, peripheral hemogram, bone marrow pathology, serum iron, serum ferritin, pathological iron deposition in multiple organs (liver, bone marrow, spleen), liver hepcidin, and bone morphogenetic protein 6 (BMP6), SMAD family member 4 (SMAD4) and transferrin receptor 2 (TfR2) mRNA expression levels were compared among the normal control, AA, iron overload and composite model groups to validate the composite model, and explore the pathogenesis and features of iron overload in this model. The results indicated marked increases in iron deposits, with significantly increased liver/body weight ratios as well as serum iron and ferritin in the iron overload and composite model groups as compared with the normal control and AA groups (P<0.05). There were marked abnormalities in iron regulation gene expression between the AA and composite model groups, as seen by the significant decrease of hepcidin expression in the liver (P<0.01) that paralleled the changes in BMP6, SMAD4, and TfR2. In summary, a composite mouse model with iron overload and AA was successfully established, and AA was indicated to possibly have a critical role in abnormal iron metabolism, which promoted the development of iron deposits. PMID:29434729

A composite mouse model of aplastic anemia complicated with iron overload.

PubMed

Wu, Dijiong; Wen, Xiaowen; Liu, Wenbin; Xu, Linlong; Ye, Baodong; Zhou, Yuhong

2018-02-01

Iron overload is commonly encountered during the course of aplastic anemia (AA), but no composite animal model has been developed yet, which hinders drug research. In the present study, the optimal dosage and duration of intraperitoneal iron dextran injection for the development of an iron overload model in mice were explored. A composite model of AA was successfully established on the principle of immune-mediated bone marrow failure. Liver volume, peripheral hemogram, bone marrow pathology, serum iron, serum ferritin, pathological iron deposition in multiple organs (liver, bone marrow, spleen), liver hepcidin, and bone morphogenetic protein 6 (BMP6), SMAD family member 4 (SMAD4) and transferrin receptor 2 (TfR2) mRNA expression levels were compared among the normal control, AA, iron overload and composite model groups to validate the composite model, and explore the pathogenesis and features of iron overload in this model. The results indicated marked increases in iron deposits, with significantly increased liver/body weight ratios as well as serum iron and ferritin in the iron overload and composite model groups as compared with the normal control and AA groups (P<0.05). There were marked abnormalities in iron regulation gene expression between the AA and composite model groups, as seen by the significant decrease of hepcidin expression in the liver (P<0.01) that paralleled the changes in BMP6, SMAD4, and TfR2. In summary, a composite mouse model with iron overload and AA was successfully established, and AA was indicated to possibly have a critical role in abnormal iron metabolism, which promoted the development of iron deposits.

The contribution of Plasmodium chabaudi to our understanding of malaria

PubMed Central

Stephens, Robin; Culleton, Richard L.; Lamb, Tracey J.

2014-01-01

Malaria kills close to a million people every year, mostly children under the age of five. In the drive towards the development of an effective vaccine and new chemotherapeutic targets for malaria, field-based studies on human malaria infection and laboratory-based studies using animal models of malaria offer complementary opportunities to further our understanding of the mechanisms behind malaria infection and pathology. We outline here the parallels between the Plasmodium chabaudi mouse model of malaria and human malaria. We will highlight the contribution of P. chabaudi to our understanding of malaria in particular, how the immune response in malaria infection is initiated and regulated, its role in pathology, and how immunological memory is maintained. We will also discuss areas where new tools have opened up potential areas of exploration using this invaluable model system. PMID:22100995

Beyond 'knock-out' mice: new perspectives for the programmed modification of the mammalian genome.

PubMed

Cohen-Tannoudji, M; Babinet, C

1998-10-01

The emergence of gene inactivation by homologous recombination methodology in embryonic stem cells has revolutionized the field of mouse genetics. Indeed, the availability of a rapidly growing number of mouse null mutants has represented an invaluable source of knowledge on mammalian development, cellular biology and physiology and has provided many models for human inherited diseases. In recent years, improvements of the original 'knock-out' strategy, as well as the exploitation of exogenous enzymatic systems that are active in the recombination process, have considerably extended the range of genetic manipulations that can be produced. For example, it is now possible to create a mouse bearing a targeted point mutation as the unique change in its entire genome therefore allowing very fine dissection of gene function in vivo. Chromosome alterations such as large deletions, inversions or translocations can also be designed and will facilitate the global functional analysis of the mouse genome. This will extend the possibilities of creating models of human pathologies that frequently originate from various chromosomal disorders. Finally, the advent of methods allowing conditional gene targeting will open the way for the analysis of the consequence of a particular mutation in a defined organ and at a specific time during the life of a mouse.

MITOCHONDRIAL DISEASES PART III: THERAPEUTIC INTERVENTIONS IN MOUSE MODELS OF OXPHOS DEFICIENCIES

PubMed Central

Peralta, Susana; Torraco, Alessandra; Iommarini, Luisa; Diaz, Francisca

2015-01-01

Mitochondrial defects are the cause of numerous disorders affecting the oxidative phosphorylation system (OXPHOS) in humans leading predominantly to neurological and muscular degeneration. The molecular origin, manifestations, and progression of mitochondrial diseases have a broad spectrum, which makes very challenging to find a globally effective therapy. The study of the molecular mechanisms underlying the mitochondrial dysfunction indicates that there is a wide range of pathways, enzymes and molecules that could be potentially targeted for therapeutic purpose. Therefore, focusing on the pathology of the disease is essential to design new treatments. In this review, we will summarize and discuss the different therapeutic interventions tested in some mouse models of mitochondrial diseases laying emphasis on the molecular mechanisms of action and their potential applications. PMID:25638392

Evaluation of diffusion kurtosis imaging in ex vivo hypomyelinated mouse brains.

PubMed

Kelm, Nathaniel D; West, Kathryn L; Carson, Robert P; Gochberg, Daniel F; Ess, Kevin C; Does, Mark D

2016-01-01

Diffusion tensor imaging (DTI), diffusion kurtosis imaging (DKI), and DKI-derived white matter tract integrity metrics (WMTI) were experimentally evaluated ex vivo through comparisons to histological measurements and established magnetic resonance imaging (MRI) measures of myelin in two knockout mouse models with varying degrees of hypomyelination. DKI metrics of mean and radial kurtosis were found to be better indicators of myelin content than conventional DTI metrics. The biophysical WMTI model based on the DKI framework reported on axon water fraction with good accuracy in cases with near normal axon density, but did not provide additional specificity to myelination. Overall, DKI provided additional information regarding white matter microstructure compared with DTI, making it an attractive method for future assessments of white matter development and pathology. Copyright © 2015 Elsevier Inc. All rights reserved.

A Novel Form of Compensation in the Tg2576 Amyloid Mouse Model of Alzheimer’s Disease

PubMed Central

Somogyi, Attila; Katonai, Zoltán; Alpár, Alán; Wolf, Ervin

2016-01-01

One century after its first description, pathology of Alzheimer’s disease (AD) is still poorly understood. Amyloid-related dendritic atrophy and membrane alterations of susceptible brain neurons in AD, and in animal models of AD are widely recognized. However, little effort has been made to study the potential effects of combined morphological and membrane alterations on signal transfer and synaptic integration in neurons that build up affected neural networks in AD. In this study spatial reconstructions and electrophysiological measurements of layer II/III pyramidal neurons of the somatosensory cortex from wild-type (WT) and transgenic (TG) human amyloid precursor protein (hAPP) overexpressing Tg2576 mice were used to build faithful segmental cable models of these neurons. Local synaptic activities were simulated in various points of the dendritic arbors and properties of subthreshold dendritic impulse propagation and predictors of synaptic input pattern recognition ability were quantified and compared in modeled WT and TG neurons. Despite the widespread dendritic degeneration and membrane alterations in mutant mouse neurons, surprisingly little, or no change was detected in steady-state and 50 Hz sinusoidal voltage transfers, current transfers, and local and propagation delays of PSPs traveling along dendrites of TG neurons. Synaptic input pattern recognition ability was also predicted to be unaltered in TG neurons in two different soma-dendritic membrane models investigated. Our simulations predict the way how subthreshold dendritic signaling and pattern recognition are preserved in TG neurons: amyloid-related membrane alterations compensate for the pathological effects that dendritic atrophy has on subthreshold dendritic signal transfer and integration in layer II/III somatosensory neurons of this hAPP mouse model for AD. Since neither propagation of single PSPs nor integration of multiple PSPs (pattern recognition) changes in TG neurons, we conclude that AD-related neuronal hyperexcitability cannot be accounted for by altered subthreshold dendritic signaling in these neurons but hyperexcitability is related to changes in active membrane properties and network connectivity. PMID:27378850

Investigation of the neuroprotective effects of bee-venom acupuncture in a mouse model of Parkinson's disease by using immunohistochemistry and In-vivo 1H magnetic resonance spectroscopy at 9.4 T

NASA Astrophysics Data System (ADS)

Yoon, Moon-Hyun; Lee, Do-Wan; Kim, Hyun-Jin; Chung, Jin-Yeung; Doo, Ah-Reum; Park, Hi-Joon; Kim, Seung-Nam; Choe, Bo-Young

2013-01-01

Neuroprotective therapeutics slows down the degeneration process in animal models of Parkinson's disease (PD). The neuronal survival in PD animal models is often measured by using immunohistochemistry. However, dynamic changes in the pathology of the brain cannot be explored with this technique. Application of in-vivo 1H magnetic resonance spectroscopy (1H MRS) can cover this shortcoming, as these techniques are non-invasive and can be repeated over time in the same animal. Thus, the sensitivity of both techniques to measure changes in the PD pathology was explored in an experiment studying the neuroprotective effects of the vigilance enhancer bee-venom (BV) in a mouse model of PD. The mice were pre-treated with 0.02-ml BV administered to the acupuncture point GB34 (Yangneungcheon) once every 3 days for 2 weeks. Three groups were classified as control, MPTP-intoxicated PD model and BV-treated mice. Outer volume suppression combined with the ultra-short echo-time STEAM (TE = 2.2 ms, TM = 20 ms, TR = 5000 ms) was used for localized in-vivo 1H MRS. Based on the 1H MRS spectral analysis, substantial changes of the neurochemical profiles were evaluated in the three investigated groups. In particular, the glutamate complex (Glx)/creatine (Cr) ratio (7.72 ± 1.25) in the PD group was significantly increased compared to that in the control group (3.93 ± 2.21, P = 0.001). Compared to the baseline values, the Glx/Cr ratio of the BV-treated group was significantly decreased 2 weeks after MPTP intoxication (one-way ANOVA, p < 0.05). In conclusion, the present study demonstrated that neurochemical alterations occurred in the three groups and that the neuroprotective effects of the BV acupuncture in a mouse model of PD could be quantified by using immunohistochemistry and 1H MRS.

A Novel Form of Compensation in the Tg2576 Amyloid Mouse Model of Alzheimer's Disease.

PubMed

Somogyi, Attila; Katonai, Zoltán; Alpár, Alán; Wolf, Ervin

2016-01-01

One century after its first description, pathology of Alzheimer's disease (AD) is still poorly understood. Amyloid-related dendritic atrophy and membrane alterations of susceptible brain neurons in AD, and in animal models of AD are widely recognized. However, little effort has been made to study the potential effects of combined morphological and membrane alterations on signal transfer and synaptic integration in neurons that build up affected neural networks in AD. In this study spatial reconstructions and electrophysiological measurements of layer II/III pyramidal neurons of the somatosensory cortex from wild-type (WT) and transgenic (TG) human amyloid precursor protein (hAPP) overexpressing Tg2576 mice were used to build faithful segmental cable models of these neurons. Local synaptic activities were simulated in various points of the dendritic arbors and properties of subthreshold dendritic impulse propagation and predictors of synaptic input pattern recognition ability were quantified and compared in modeled WT and TG neurons. Despite the widespread dendritic degeneration and membrane alterations in mutant mouse neurons, surprisingly little, or no change was detected in steady-state and 50 Hz sinusoidal voltage transfers, current transfers, and local and propagation delays of PSPs traveling along dendrites of TG neurons. Synaptic input pattern recognition ability was also predicted to be unaltered in TG neurons in two different soma-dendritic membrane models investigated. Our simulations predict the way how subthreshold dendritic signaling and pattern recognition are preserved in TG neurons: amyloid-related membrane alterations compensate for the pathological effects that dendritic atrophy has on subthreshold dendritic signal transfer and integration in layer II/III somatosensory neurons of this hAPP mouse model for AD. Since neither propagation of single PSPs nor integration of multiple PSPs (pattern recognition) changes in TG neurons, we conclude that AD-related neuronal hyperexcitability cannot be accounted for by altered subthreshold dendritic signaling in these neurons but hyperexcitability is related to changes in active membrane properties and network connectivity.

Beneficial effects of exercise in a transgenic mouse model of Alzheimer's disease-like Tau pathology.

PubMed

Belarbi, Karim; Burnouf, Sylvie; Fernandez-Gomez, Francisco-Jose; Laurent, Cyril; Lestavel, Sophie; Figeac, Martin; Sultan, Audrey; Troquier, Laetitia; Leboucher, Antoine; Caillierez, Raphaëlle; Grosjean, Marie-Eve; Demeyer, Dominique; Obriot, Hélène; Brion, Ingrid; Barbot, Bérangère; Galas, Marie-Christine; Staels, Bart; Humez, Sandrine; Sergeant, Nicolas; Schraen-Maschke, Susanna; Muhr-Tailleux, Anne; Hamdane, Malika; Buée, Luc; Blum, David

2011-08-01

Tau pathology is encountered in many neurodegenerative disorders known as tauopathies, including Alzheimer's disease. Physical activity is a lifestyle factor affecting processes crucial for memory and synaptic plasticity. Whether long-term voluntary exercise has an impact on Tau pathology and its pathophysiological consequences is currently unknown. To address this question, we investigated the effects of long-term voluntary exercise in the THY-Tau22 transgenic model of Alzheimer's disease-like Tau pathology, characterized by the progressive development of Tau pathology, cholinergic alterations and subsequent memory impairments. Three-month-old THY-Tau22 mice and wild-type littermates were assigned to standard housing or housing supplemented with a running wheel. After 9 months of exercise, mice were evaluated for memory performance and examined for hippocampal Tau pathology, cholinergic defects, inflammation and genes related to cholesterol metabolism. Exercise prevented memory alterations in THY-Tau22 mice. This was accompanied by a decrease in hippocampal Tau pathology and a prevention of the loss of expression of choline acetyltransferase within the medial septum. Whereas the expression of most cholesterol-related genes remained unchanged in the hippocampus of running THY-Tau22 mice, we observed a significant upregulation in mRNA levels of NPC1 and NPC2, genes involved in cholesterol trafficking from the lysosomes. Our data support the view that long-term voluntary physical exercise is an effective strategy capable of mitigating Tau pathology and its pathophysiological consequences. Copyright © 2011 Elsevier Inc. All rights reserved.

Ebselen alleviates testicular pathology in mice with Zika virus infection and prevents its sexual transmission.

PubMed

Simanjuntak, Yogy; Liang, Jian-Jong; Chen, Si-Yu; Li, Jin-Kun; Lee, Yi-Ling; Wu, Han-Chung; Lin, Yi-Ling

2018-02-01

Despite the low case fatality, Zika virus (ZIKV) infection has been associated with microcephaly in infants and Guillain-Barré syndrome. Antiviral and vaccine developments against ZIKV are still ongoing; therefore, in the meantime, preventing the disease transmission is critical. Primarily transmitted by Aedes species mosquitoes, ZIKV also can be sexually transmitted. We used AG129 mice lacking interferon-α/β and -γ receptors to study the testicular pathogenesis and sexual transmission of ZIKV. Infection of ZIKV progressively damaged mouse testes, increased testicular oxidative stress as indicated by the levels of reactive oxygen species, nitric oxide, glutathione peroxidase 4, spermatogenesis-associated-18 homolog in sperm and pro-inflammatory cytokines including IL-1β, IL-6, and G-CSF. We then evaluated the potential role of the antioxidant ebselen (EBS) in alleviating the testicular pathology with ZIKV infection. EBS treatment significantly reduced ZIKV-induced testicular oxidative stress, leucocyte infiltration and production of pro-inflammatory response. Furthermore, it improved testicular pathology and prevented the sexual transmission of ZIKV in a male-to-female mouse sperm transfer model. EBS is currently in clinical trials for various diseases. ZIKV infection could be on the list for potential use of EBS, for alleviating the testicular pathogenesis with ZIKV infection and preventing its sexual transmission.

Of Faeces and Sweat. How Much a Mouse is Willing to Run: Having a Hard Time Measuring Spontaneous Physical Activity in Different Mouse Sub-Strains.

PubMed

Coletti, Dario; Adamo, Sergio; Moresi, Viviana

2017-02-24

Invited Letter to the Editor. Physical activity has multiple beneficial effects in the physiology and pathology of the organism. In particular, we and other groups have shown that running counteracts cancer cachexia in both humans and rodents. The latter are prone to exercise in wheel-equipped cages even at advanced stages of cachexia. However, when we wanted to replicate the experimental model routinely used at the University of Rome in a different laboratory (i.e. at Paris 6 University), we had to struggle with puzzling results due to unpredicted mouse behavior. Here we report the experience and offer the explanation underlying these apparently irreproducible results. The original data are currently used for teaching purposes in undergraduate student classes of biological sciences.

Diffusion fMRI detects white-matter dysfunction in mice with acute optic neuritis

PubMed Central

Lin, Tsen-Hsuan; Spees, William M.; Chiang, Chia-Wen; Trinkaus, Kathryn; Cross, Anne H.; Song, Sheng-Kwei

2014-01-01

Optic neuritis is a frequent and early symptom of multiple sclerosis (MS). Conventional magnetic resonance (MR) techniques provide means to assess multiple MS-related pathologies, including axonal injury, demyelination, and inflammation. A method to directly and non-invasively probe white-matter function could further elucidate the interplay of underlying pathologies and functional impairments. Previously, we demonstrated a significant 27% activation-associated decrease in the apparent diffusion coefficient of water perpendicular to the axonal fibers (ADC⊥) in normal C57BL/6 mouse optic nerve with visual stimulation using diffusion fMRI. Here we apply this approach to explore the relationship between visual acuity, optic nerve pathology, and diffusion fMRI in the experimental autoimmune encephalomyelitis (EAE) mouse model of optic neuritis. Visual stimulation produced a significant 25% (vs. baseline) ADC⊥ decrease in sham EAE optic nerves, while only a 7% (vs. baseline) ADC⊥ decrease was seen in EAE mice with acute optic neuritis. The reduced activation-associated ADC⊥ response correlated with post-MRI immunohistochemistry determined pathologies (including inflammation, demyelination, and axonal injury). The negative correlation between activation-associated ADC⊥ response and visual acuity was also found when pooling EAE-affected and sham groups under our experimental criteria. Results suggest that reduction in diffusion fMRI directly reflects impaired axonal-activation in EAE mice with optic neuritis. Diffusion fMRI holds promise for directly gauging in vivo white-matter dysfunction or therapeutic responses in MS patients. PMID:24632420

Zika virus infection in immunocompetent pregnant mice causes fetal damage and placental pathology in the absence of fetal infection

PubMed Central

Kummer, Lawrence W.; Lanthier, Paula; Kim, In-Jeong; Kuki, Atsuo; Thomas, Stephen J.

2018-01-01

Zika virus (ZIKV) infection during human pregnancy may cause diverse and serious congenital defects in the developing fetus. Previous efforts to generate animal models of human ZIKV infection and clinical symptoms often involved manipulating mice to impair their Type I interferon (IFN) signaling, thereby allowing enhanced infection and vertical transmission of virus to the embryo. Here, we show that even pregnant mice competent to generate Type I IFN responses that can limit ZIKV infection nonetheless develop profound placental pathology and high frequency of fetal demise. We consistently found that maternal ZIKV exposure led to placental pathology and that ZIKV RNA levels measured in maternal, placental or embryonic tissues were not predictive of the pathological effects seen in the embryos. Placental pathology included trophoblast hyperplasia in the labyrinth, trophoblast giant cell necrosis in the junctional zone, and loss of embryonic vessels. Our findings suggest that, in this context of limited infection, placental pathology rather than embryonic/fetal viral infection may be a stronger contributor to adverse pregnancy outcomes in mice. Our finding demonstrates that in immunocompetent mice, direct viral infection of the embryo is not essential for fetal demise. Our immunologically unmanipulated pregnancy mouse model provides a consistent and easily measurable congenital abnormality readout to assess fetal outcome, and may serve as an additional model to test prophylactic and therapeutic interventions to protect the fetus during pregnancy, and for studying the mechanisms of ZIKV congenital immunopathogenesis. PMID:29634758

Mouse Models for Studying Oral Cancer: Impact in the Era of Cancer Immunotherapy.

PubMed

Luo, J J; Young, C D; Zhou, H M; Wang, X J

2018-04-01

Model systems for oral cancer research have progressed from tumor epithelial cell cultures to in vivo systems that mimic oral cancer genetics, pathological characteristics, and tumor-stroma interactions of oral cancer patients. In the era of cancer immunotherapy, it is imperative to use model systems to test oral cancer prevention and therapeutic interventions in the presence of an immune system and to discover mechanisms of stromal contributions to oral cancer carcinogenesis. Here, we review in vivo mouse model systems commonly used for studying oral cancer and discuss the impact these models are having in advancing basic mechanisms, chemoprevention, and therapeutic intervention of oral cancer while highlighting recent discoveries concerning the role of immune cells in oral cancer. Improvements to in vivo model systems that highly recapitulate human oral cancer hold the key to identifying features of oral cancer initiation, progression, and invasion as well as molecular and cellular targets for prevention, therapeutic response, and immunotherapy development.

Early alterations in blood and brain RANTES and MCP-1 expression and the effect of exercise frequency in the 3xTg-AD mouse model of Alzheimer's disease.

PubMed

Haskins, Morgan; Jones, Terry E; Lu, Qun; Bareiss, Sonja K

2016-01-01

Exercise has been shown to protect against cognitive decline and Alzheimer's disease (AD) progression, however the dose of exercise required to protect against AD is unknown. Recent studies show that the pathological processes leading to AD cause characteristic alterations in blood and brain inflammatory proteins that are associated with the progression of AD, suggesting that these markers could be used to diagnosis and monitor disease progression. The purpose of this study was to determine the impact of exercise frequency on AD blood chemokine profiles, and correlate these findings with chemokine brain expression changes in the triple transgenic AD (3xTg-AD) mouse model. Three month old 3xTg-AD mice were subjected to 12 weeks of moderate intensity wheel running at a frequency of either 1×/week or 3×/week. Blood and cortical tissue were analyzed for expression of monocyte chemotactic protein-1 (MCP-1) and regulated and normal T cell expressed and secreted (RANTES). Alterations in blood RANTES and MCP-1 expression were evident at 3 and 6 month old animals compared to WT animals. Three times per week exercise but not 1×/week exercise was effective at reversing serum and brain RANTES and MCP-1 expression to the levels of WT controls, revealing a dose dependent response to exercise. Analysis of these chemokines showed a strong negative correlation between blood and brain expression of RANTES. The results indicate that alterations in serum and brain inflammatory chemokines are evident as early signs of Alzheimer's disease pathology and that higher frequency exercise was necessary to restore blood and brain inflammatory expression levels in this AD mouse model. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

The effects of aging, housing and ibuprofen treatment on brain neurochemistry in a triple transgene Alzheimer's disease mouse model using magnetic resonance spectroscopy and imaging.

PubMed

Choi, Ji-Kyung; Carreras, Isabel; Aytan, Nur; Jenkins-Sahlin, Eric; Dedeoglu, Alpaslan; Jenkins, Bruce G

2014-11-24

We investigated a triple transgene Alzheimer's disease (AD) mouse model that recapitulates many of the neurochemical, anatomic, pathologic and behavioral defects seen in human AD. We studied the mice as a function of age and brain region and investigated potential therapy with the non-steroidal anti-inflammatory drug ibuprofen. Magnetic resonance spectroscopy (MRS) showed alterations characteristic of AD (i.e. increased myo-inositol and decreased N-acetylaspartate (NAA)). Mice at 6 months of age showed an increase in myo-inositol in the hippocampus at a time when the Aβ is intracellular, but not in amygdala or cortex. Myo-inositol increased as a function of age in the amygdala, cortex and striatum while NAA decreased only in the hippocampus and cortex at 17-23 months of age. Ibuprofen protected the increase of myo-inositol at six months of age in the hippocampus, but had no effect at 17-23 months of age (a time when Aβ is extracellular). In vivo MRI and MRS showed that at 17-23 months of age there was a significant protective effect of ibuprofen on hippocampal volume and NAA loss. Together, these data show the following: the increase in myo-inositol occurs before the decrease in NAA in hippocampus but not cortex; the hippocampus shows earlier changes than does the amygdale or cortex consistent with earlier deposition of Aβ40-42 in the hippocampus and ibuprofen protects against multiple components of the AD pathology. These data also show a profound effect of housing on this particular mouse model. Published by Elsevier B.V.

Preclinical mouse model to monitor live Muc5b-producing conjunctival goblet cell density under pharmacological treatments.

PubMed

Portal, Céline; Gouyer, Valérie; Gottrand, Frédéric; Desseyn, Jean-Luc

2017-01-01

Modification of mucous cell density and gel-forming mucin production are established hallmarks of mucosal diseases. Our aim was to develop and validate a mouse model to study live goblet cell density in pathological situations and under pharmacological treatments. We created a reporter mouse for the gel-forming mucin gene Muc5b. Muc5b-positive goblet cells were studied in the eye conjunctiva by immunohistochemistry and probe-based confocal laser endomicroscopy (pCLE) in living mice. Dry eye syndrome (DES) model was induced by topical application of benzalkonium chloride (BAK) and recombinant interleukine (rIL) 13 was administered to reverse the goblet cell loss in the DES model. Almost 50% of the total of conjunctival goblet cells are Muc5b+ in unchallenged mice. The decrease density of Muc5b+ conjunctival goblet cell population in the DES model reflects the whole conjunctival goblet cell loss. Ten days of BAK in one eye followed by 4 days without any treatment induced a -18.3% decrease in conjunctival goblet cell density. A four days of rIL13 application in the DES model restored the normal goblet cell density. Muc5b is a biological marker of DES mouse models. We bring the proof of concept that our model is unique and allows a better understanding of the mechanisms that regulate gel-forming mucin production/secretion and mucous cell differentiation in the conjunctiva of living mice and can be used to test treatment compounds in mucosal disease models.

High-throughput 3D whole-brain quantitative histopathology in rodents

PubMed Central

Vandenberghe, Michel E.; Hérard, Anne-Sophie; Souedet, Nicolas; Sadouni, Elmahdi; Santin, Mathieu D.; Briet, Dominique; Carré, Denis; Schulz, Jocelyne; Hantraye, Philippe; Chabrier, Pierre-Etienne; Rooney, Thomas; Debeir, Thomas; Blanchard, Véronique; Pradier, Laurent; Dhenain, Marc; Delzescaux, Thierry

2016-01-01

Histology is the gold standard to unveil microscopic brain structures and pathological alterations in humans and animal models of disease. However, due to tedious manual interventions, quantification of histopathological markers is classically performed on a few tissue sections, thus restricting measurements to limited portions of the brain. Recently developed 3D microscopic imaging techniques have allowed in-depth study of neuroanatomy. However, quantitative methods are still lacking for whole-brain analysis of cellular and pathological markers. Here, we propose a ready-to-use, automated, and scalable method to thoroughly quantify histopathological markers in 3D in rodent whole brains. It relies on block-face photography, serial histology and 3D-HAPi (Three Dimensional Histology Analysis Pipeline), an open source image analysis software. We illustrate our method in studies involving mouse models of Alzheimer’s disease and show that it can be broadly applied to characterize animal models of brain diseases, to evaluate therapeutic interventions, to anatomically correlate cellular and pathological markers throughout the entire brain and to validate in vivo imaging techniques. PMID:26876372

Expression and function of Anoctamin 1/TMEM16A calcium-activated chloride channels in airways of in vivo mouse models for cystic fibrosis research.

PubMed

Hahn, Anne; Salomon, Johanna J; Leitz, Dominik; Feigenbutz, Dennis; Korsch, Lisa; Lisewski, Ina; Schrimpf, Katrin; Millar-Büchner, Pamela; Mall, Marcus A; Frings, Stephan; Möhrlen, Frank

2018-06-02

Physiological processes of vital importance are often safeguarded by compensatory systems that substitute for primary processes in case these are damaged by gene mutation. Ca 2+ -dependent Cl - secretion in airway epithelial cells may provide such a compensatory mechanism for impaired Cl - secretion via cystic fibrosis transmembrane conductance regulator (CFTR) channels in cystic fibrosis (CF). Anoctamin 1 (ANO1) Ca 2+ -gated Cl - channels are known to contribute to calcium-dependent Cl - secretion in tracheal and bronchial epithelia. In the present study, two mouse models of CF were examined to assess a potential protective function of Ca 2+ -dependent Cl - secretion, a CFTR deletion model (cftr -/- ), and a CF pathology model that overexpresses the epithelial Na + channel β-subunit (βENaC), which is encoded by the Scnn1b gene, specifically in airway epithelia (Scnn1b-Tg). The expression levels of ANO1 were examined by mRNA and protein content, and the channel protein distribution between ciliated and non-ciliated epithelial cells was analyzed. Moreover, Ussing chamber experiments were conducted to compare Ca 2+ -dependent Cl - secretion between wild-type animals and the two mouse models. Our results demonstrate that CFTR and ANO1 channels were co-expressed with ENaC in non-ciliated cells of mouse tracheal and bronchial epithelia. Ciliated cells did not express these proteins. Despite co-localization of CFTR and ANO1 in the same cell type, cells in cftr -/- mice displayed no altered expression of ANO1. Similarly, ANO1 expression was unaffected by βENaC overexpression in the Scnn1b-Tg line. These results suggest that the CF-related environment in the two mouse models did not induce ANO1 overexpression as a compensatory system.

The role of ryanodine receptor type 3 in a mouse model of Alzheimer disease

PubMed Central

Liu, Jie; Supnet, Charlene; Sun, Suya; Zhang, Hua; Good, Levi; Popugaeva, Elena; Bezprozvanny, Ilya

2014-01-01

Dysregulated endoplasmic reticulum (ER) calcium (Ca2+) signaling is reported to play an important role in Alzheimer disease (AD) pathogenesis. The role of ER Ca2+ release channels, the ryanodine receptors (RyanRs), has been extensively studied in AD models and RyanR expression and activity are upregulated in the brains of various familial AD (FAD) models. The objective of this study was to utilize a genetic approach to evaluate the importance of RyanR type 3 (RyanR3) in the context of AD pathology. PMID:24476841

Dysregulation of synaptic proteins, dendritic spine abnormalities and pathological plasticity of synapses as experience-dependent mediators of cognitive and psychiatric symptoms in Huntington's disease.

PubMed

Nithianantharajah, J; Hannan, A J

2013-10-22

Huntington's disease (HD) is an autosomal dominant tandem repeat expansion disorder involving cognitive, psychiatric and motor symptoms. The expanded trinucleotide (CAG) repeat leads to an extended polyglutamine tract in the huntingtin protein and a subsequent cascade of molecular and cellular pathogenesis. One of the key features of neuropathology, which has been shown to precede the eventual loss of neurons in the cerebral cortex, striatum and other areas, are changes to synapses, including the dendritic protrusions known as spines. In this review we will focus on synapse and spine pathology in HD, including molecular and experience-dependent aspects of pathogenesis. Dendritic spine pathology has been found in both the human HD brain at post mortem as well as various transgenic and knock-in animal models. These changes may help explain the symptoms in HD, and synaptopathy within the cerebral cortex may be particularly important in mediating the psychiatric and cognitive manifestations of this disease. The earliest stages of synaptic dysfunction in HD, as assayed in various mouse models, appears to involve changes in synaptic proteins and associated physiological abnormalities such as synaptic plasticity deficits. In mouse models, synaptic and cortical plasticity deficits have been directly correlated with the onset of cognitive deficits, implying a causal link. Furthermore, following the discovery that environmental enrichment can delay onset of affective, cognitive and motor deficits in HD transgenic mice, specific synaptic molecules shown to be dysregulated by the polyglutamine-induced toxicity were also found to be beneficially modulated by environmental stimulation. This identifies potential molecular targets for future therapeutic developments to treat this devastating disease. Copyright © 2012 IBRO. Published by Elsevier Ltd. All rights reserved.

Defective mitochondrial dynamics is an early event in skeletal muscle of an amyotrophic lateral sclerosis mouse model.

PubMed

Luo, Guo; Yi, Jianxun; Ma, Changling; Xiao, Yajuan; Yi, Frank; Yu, Tian; Zhou, Jingsong

2013-01-01

Mitochondria are dynamic organelles that constantly undergo fusion and fission to maintain their normal functionality. Impairment of mitochondrial dynamics is implicated in various neurodegenerative disorders. Amyotrophic lateral sclerosis (ALS) is an adult-onset neuromuscular degenerative disorder characterized by motor neuron death and muscle atrophy. ALS onset and progression clearly involve motor neuron degeneration but accumulating evidence suggests primary muscle pathology may also be involved. Here, we examined mitochondrial dynamics in live skeletal muscle of an ALS mouse model (G93A) harboring a superoxide dismutase mutation (SOD1(G93A)). Using confocal microscopy combined with overexpression of mitochondria-targeted photoactivatable fluorescent proteins, we discovered abnormal mitochondrial dynamics in skeletal muscle of young G93A mice before disease onset. We further demonstrated that similar abnormalities in mitochondrial dynamics were induced by overexpression of mutant SOD1(G93A) in skeletal muscle of normal mice, indicating the SOD1 mutation drives ALS-like muscle pathology in the absence of motor neuron degeneration. Mutant SOD1(G93A) forms aggregates inside muscle mitochondria and leads to fragmentation of the mitochondrial network as well as mitochondrial depolarization. Partial depolarization of mitochondrial membrane potential in normal muscle by carbonyl cyanide p-trifluoromethoxyphenylhydrazone (FCCP) caused abnormalities in mitochondrial dynamics similar to that in the SOD1(G93A) model muscle. A specific mitochondrial fission inhibitor (Mdivi-1) reversed the SOD1(G93A) action on mitochondrial dynamics, indicating SOD1(G93A) likely promotes mitochondrial fission process. Our results suggest that accumulation of mutant SOD1(G93A) inside mitochondria, depolarization of mitochondrial membrane potential and abnormal mitochondrial dynamics are causally linked and cause intrinsic muscle pathology, which occurs early in the course of ALS and may actively promote ALS progression.

AAV-dominant negative tumor necrosis factor (DN-TNF) gene transfer to the striatum does not rescue medium spiny neurons in the YAC128 mouse model of Huntington's disease.

PubMed

Alto, Laura Taylor; Chen, Xi; Ruhn, Kelly A; Treviño, Isaac; Tansey, Malú G

2014-01-01

CNS inflammation is a hallmark of neurodegenerative disease, and recent studies suggest that the inflammatory response may contribute to neuronal demise. In particular, increased tumor necrosis factor (TNF) signaling is implicated in the pathology of both Parkinson's disease (PD) and Alzheimer's disease (AD). We have previously shown that localized gene delivery of dominant negative TNF to the degenerating brain region can limit pathology in animal models of PD and AD. TNF is upregulated in Huntington's disease (HD), like in PD and AD, but it is unknown whether TNF signaling contributes to neuronal degeneration in HD. We used in vivo gene delivery to test whether selective reduction of soluble TNF signaling could attenuate medium spiny neuron (MSN) degeneration in the YAC128 transgenic (TG) mouse model of Huntington's disease (HD). AAV vectors encoding cDNA for dominant-negative tumor necrosis factor (DN-TNF) or GFP (control) were injected into the striatum of young adult wild type WT and YAC128 TG mice and achieved 30-50% target coverage. Expression of dominant negative TNF protein was confirmed immunohistologically and biochemically and was maintained as mice aged to one year, but declined significantly over time. However, the extent of striatal DN-TNF gene transfer achieved in our studies was not sufficient to achieve robust effects on neuroinflammation, rescue degenerating MSNs or improve motor function in treated mice. Our findings suggest that alternative drug delivery strategies should be explored to determine whether greater target coverage by DN-TNF protein might afford some level of neuroprotection against HD-like pathology and/or that soluble TNF signaling may not be the primary driver of striatal neuroinflammation and MSN loss in YAC128 TG mice.

Pyroglutamate-3 Amyloid-β Deposition in the Brains of Humans, Non-Human Primates, Canines, and Alzheimer Disease–Like Transgenic Mouse Models

PubMed Central

Frost, Jeffrey L.; Le, Kevin X.; Cynis, Holger; Ekpo, Elizabeth; Kleinschmidt, Martin; Palmour, Roberta M.; Ervin, Frank R.; Snigdha, Shikha; Cotman, Carl W.; Saido, Takaomi C.; Vassar, Robert J.; George-Hyslop, Peter St.; Ikezu, Tsuneya; Schilling, Stephan; Demuth, Hans-Ulrich; Lemere, Cynthia A.

2014-01-01

Amyloid-β (Aβ) peptides, starting with pyroglutamate at the third residue (pyroGlu-3 Aβ), are a major species deposited in the brain of Alzheimer disease (AD) patients. Recent studies suggest that this isoform shows higher toxicity and amyloidogenecity when compared to full-length Aβ peptides. Here, we report the first comprehensive and comparative IHC evaluation of pyroGlu-3 Aβ deposition in humans and animal models. PyroGlu-3 Aβ immunoreactivity (IR) is abundant in plaques and cerebral amyloid angiopathy of AD and Down syndrome patients, colocalizing with general Aβ IR. PyroGlu-3 Aβ is further present in two nontransgenic mammalian models of cerebral amyloidosis, Caribbean vervets, and beagle canines. In addition, pyroGlu-3 Aβ deposition was analyzed in 12 different AD-like transgenic mouse models. In contrast to humans, all transgenic models showed general Aβ deposition preceding pyroGlu-3 Aβ deposition. The findings varied greatly among the mouse models concerning age of onset and cortical brain region. In summary, pyroGlu-3 Aβ is a major species of β-amyloid deposited early in diffuse and focal plaques and cerebral amyloid angiopathy in humans and nonhuman primates, whereas it is deposited later in a subset of focal and vascular amyloid in AD-like transgenic mouse models. Given the proposed decisive role of pyroGlu-3 Aβ peptides for the development of human AD pathology, this study provides insights into the usage of animal models in AD studies. PMID:23747948

Innate immune memory in the brain shapes neurological disease hallmarks.

PubMed

Wendeln, Ann-Christin; Degenhardt, Karoline; Kaurani, Lalit; Gertig, Michael; Ulas, Thomas; Jain, Gaurav; Wagner, Jessica; Häsler, Lisa M; Wild, Katleen; Skodras, Angelos; Blank, Thomas; Staszewski, Ori; Datta, Moumita; Centeno, Tonatiuh Pena; Capece, Vincenzo; Islam, Md Rezaul; Kerimoglu, Cemil; Staufenbiel, Matthias; Schultze, Joachim L; Beyer, Marc; Prinz, Marco; Jucker, Mathias; Fischer, André; Neher, Jonas J

2018-04-01

Innate immune memory is a vital mechanism of myeloid cell plasticity that occurs in response to environmental stimuli and alters subsequent immune responses. Two types of immunological imprinting can be distinguished-training and tolerance. These are epigenetically mediated and enhance or suppress subsequent inflammation, respectively. Whether immune memory occurs in tissue-resident macrophages in vivo and how it may affect pathology remains largely unknown. Here we demonstrate that peripherally applied inflammatory stimuli induce acute immune training and tolerance in the brain and lead to differential epigenetic reprogramming of brain-resident macrophages (microglia) that persists for at least six months. Strikingly, in a mouse model of Alzheimer's pathology, immune training exacerbates cerebral β-amyloidosis and immune tolerance alleviates it; similarly, peripheral immune stimulation modifies pathological features after stroke. Our results identify immune memory in the brain as an important modifier of neuropathology.

An optimized, fast-to-perform mouse lung infection model with the human pathogen Chlamydia trachomatis for in vivo screening of antibiotics, vaccine candidates and modified host-pathogen interactions.

PubMed

Dutow, Pavel; Wask, Lea; Bothe, Miriam; Fehlhaber, Beate; Laudeley, Robert; Rheinheimer, Claudia; Yang, Zhangsheng; Zhong, Guangming; Glage, Silke; Klos, Andreas

2016-03-01

Chlamydia trachomatis causes sexually transmitted diseases with infertility, pelvic inflammatory disease and neonatal pneumonia as complications. The duration of urogenital mouse models with the strict mouse pathogen C. muridarum addressing vaginal shedding, pathological changes of the upper genital tract or infertility is rather long. Moreover, vaginal C. trachomatis application usually does not lead to the complications feared in women. A fast-to-perform mouse model is urgently needed to analyze new antibiotics, vaccine candidates, immune responses (in gene knockout animals) or mutants of C. trachomatis. To complement the valuable urogenital model with a much faster and quantifiable screening method, we established an optimized lung infection model for the human intracellular bacterium C. trachomatis serovar D (and L2) in immunocompetent C57BL/6J mice. We demonstrated its usefulness by sensitive determination of antibiotic effects characterizing advantages and limitations achievable by early or delayed short tetracycline treatment and single-dose azithromycin application. Moreover, we achieved partial acquired protection in reinfection with serovar D indicating usability for vaccine studies, and showed a different course of disease in absence of complement factor C3. Sensitive monitoring parameters were survival rate, body weight, clinical score, bacterial load, histological score, the granulocyte marker myeloperoxidase, IFN-γ, TNF-α, MCP-1 and IL-6. © FEMS 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Cognitive Impairment, Neuroimaging, and Alzheimer Neuropathology in Mouse Models of Down Syndrome

PubMed Central

Hamlett, Eric D.; Boger, Heather A.; Ledreux, Aurélie; Kelley, Christy M.; Mufson, Elliott J.; Falangola, Maria F.; Guilfoyle, David N.; Nixon, Ralph A.; Patterson, David; Duval, Nathan; Granholm, Ann-Charlotte E.

2016-01-01

Down syndrome (DS) is the most common non-lethal genetic condition that affects approximately 1 in 700 births in the United States of America. DS is characterized by complete or segmental chromosome 21 trisomy, which leads to variable intellectual disabilities, progressive memory loss, and accelerated neurodegeneration with age. During the last three decades, people with DS have experienced a doubling of life expectancy due to progress in treatment of medical comorbidities, which has allowed this population to reach the age when they develop early onset Alzheimer’s disease (AD). Individuals with DS develop cognitive and pathological hallmarks of AD in their fourth or fifth decade, and are currently lacking successful prevention or treatment options for dementia. The profound memory deficits associated with DS-related AD (DS-AD) have been associated with degeneration of several neuronal populations, but mechanisms of neurodegeneration are largely unexplored. The most successful animal model for DS is the Ts65Dn mouse, but several new models have also been developed. In the current review, we discuss recent findings and potential treatment options for the management of memory loss and AD neuropathology in DS mouse models. We also review age-related neuropathology, and recent findings from neuroimaging studies. The validation of appropriate DS mouse models that mimic neurodegeneration and memory loss in humans with DS can be valuable in the study of novel preventative and treatment interventions, and may be helpful in pinpointing gene-gene interactions as well as specific gene segments involved in neurodegeneration. PMID:26391050

Mitochondrial Dysfunction and Decrease in Body Weight of a Transgenic Knock-in Mouse Model for TDP-43*

PubMed Central

Stribl, Carola; Samara, Aladin; Trümbach, Dietrich; Peis, Regina; Neumann, Manuela; Fuchs, Helmut; Gailus-Durner, Valerie; Hrabě de Angelis, Martin; Rathkolb, Birgit; Wolf, Eckhard; Beckers, Johannes; Horsch, Marion; Neff, Frauke; Kremmer, Elisabeth; Koob, Sebastian; Reichert, Andreas S.; Hans, Wolfgang; Rozman, Jan; Klingenspor, Martin; Aichler, Michaela; Walch, Axel Karl; Becker, Lore; Klopstock, Thomas; Glasl, Lisa; Hölter, Sabine M.; Wurst, Wolfgang; Floss, Thomas

2014-01-01

The majority of amyotrophic lateral sclerosis (ALS) cases as well as many patients suffering from frontotemporal lobar dementia (FTLD) with ubiquitinated inclusion bodies show TDP-43 pathology, the protein encoded by the TAR DNA-binding protein (Tardbp) gene. We used recombinase-mediated cassette exchange to introduce an ALS patient cDNA into the mouse Tdp-43 locus. Expression levels of human A315T TDP-43 protein were 300% elevated in heterozygotes, whereas the endogenous mouse Tdp-43 was decreased to 20% of wild type levels as a result of disturbed feedback regulation. Heterozygous TDP-43A315TKi mutants lost 10% of their body weight and developed insoluble TDP-43 protein starting as early as 3 months after birth, a pathology that was exacerbated with age. We analyzed the splicing patterns of known Tdp-43 target genes as well as genome-wide gene expression levels in different tissues that indicated mitochondrial dysfunction. In heterozygous mutant animals, we observed a relative decrease in expression of Parkin (Park2) and the fatty acid transporter CD36 along with an increase in fatty acids, HDL cholesterol, and glucose in the blood. As seen in transmission electron microscopy, neuronal cells in motor cortices of TDP-43A315TKi animals had abnormal neuronal mitochondrial cristae formation. Motor neurons were reduced to 90%, but only slight motoric impairment was detected. The observed phenotype was interpreted as a predisease model, which might be valuable for the identification of further environmental or genetic triggers of neurodegeneration. PMID:24515116

[Programmed mouse genome modifications].

PubMed

Babinet, C

1998-02-01

The availability, in the mouse, of embryonic stem cells (ES cells) which have the ability to colonize the germ line of a developing embryo, has opened entirely new avenues to the genetic approach of embryonic development, physiology and pathology of this animal. Indeed, it is now possible, using homologous recombination in ES cells, to introduce mutations in any gene as long as it has been cloned. Thus, null as well as more subtle mutations can be created. Furthermore, scenarios are currently being derived which will allow one to generate conditional mutations. Taken together, these methods offer a tremendous tool to study gene function in vivo; they also open the way to creating murine models of human genetic diseases.

Mouse model of pulmonary cavitary tuberculosis and expression of matrix metalloproteinase-9.

PubMed

Ordonez, Alvaro A; Tasneen, Rokeya; Pokkali, Supriya; Xu, Ziyue; Converse, Paul J; Klunk, Mariah H; Mollura, Daniel J; Nuermberger, Eric L; Jain, Sanjay K

2016-07-01

Cavitation is a key pathological feature of human tuberculosis (TB), and is a well-recognized risk factor for transmission of infection, relapse after treatment and the emergence of drug resistance. Despite intense interest in the mechanisms underlying cavitation and its negative impact on treatment outcomes, there has been limited study of this phenomenon, owing in large part to the limitations of existing animal models. Although cavitation does not occur in conventional mouse strains after infection with Mycobacterium tuberculosis, cavitary lung lesions have occasionally been observed in C3HeB/FeJ mice. However, to date, there has been no demonstration that cavitation can be produced consistently enough to support C3HeB/FeJ mice as a new and useful model of cavitary TB. We utilized serial computed tomography (CT) imaging to detect pulmonary cavitation in C3HeB/FeJ mice after aerosol infection with M. tuberculosis Post-mortem analyses were performed to characterize lung lesions and to localize matrix metalloproteinases (MMPs) previously implicated in cavitary TB in situ A total of 47-61% of infected mice developed cavities during primary disease or relapse after non-curative treatments. Key pathological features of human TB, including simultaneous presence of multiple pathologies, were noted in lung tissues. Optical imaging demonstrated increased MMP activity in TB lesions and MMP-9 was significantly expressed in cavitary lesions. Tissue MMP-9 activity could be abrogated by specific inhibitors. In situ, three-dimensional analyses of cavitary lesions demonstrated that 22.06% of CD11b+ signal colocalized with MMP-9. C3HeB/FeJ mice represent a reliable, economical and tractable model of cavitary TB, with key similarities to human TB. This model should provide an excellent tool to better understand the pathogenesis of cavitation and its effects on TB treatments. © 2016. Published by The Company of Biologists Ltd.

Mouse model of pulmonary cavitary tuberculosis and expression of matrix metalloproteinase-9

PubMed Central

Ordonez, Alvaro A.; Tasneen, Rokeya; Pokkali, Supriya; Xu, Ziyue; Converse, Paul J.; Klunk, Mariah H.; Mollura, Daniel J.; Nuermberger, Eric L.

2016-01-01

ABSTRACT Cavitation is a key pathological feature of human tuberculosis (TB), and is a well-recognized risk factor for transmission of infection, relapse after treatment and the emergence of drug resistance. Despite intense interest in the mechanisms underlying cavitation and its negative impact on treatment outcomes, there has been limited study of this phenomenon, owing in large part to the limitations of existing animal models. Although cavitation does not occur in conventional mouse strains after infection with Mycobacterium tuberculosis, cavitary lung lesions have occasionally been observed in C3HeB/FeJ mice. However, to date, there has been no demonstration that cavitation can be produced consistently enough to support C3HeB/FeJ mice as a new and useful model of cavitary TB. We utilized serial computed tomography (CT) imaging to detect pulmonary cavitation in C3HeB/FeJ mice after aerosol infection with M. tuberculosis. Post-mortem analyses were performed to characterize lung lesions and to localize matrix metalloproteinases (MMPs) previously implicated in cavitary TB in situ. A total of 47-61% of infected mice developed cavities during primary disease or relapse after non-curative treatments. Key pathological features of human TB, including simultaneous presence of multiple pathologies, were noted in lung tissues. Optical imaging demonstrated increased MMP activity in TB lesions and MMP-9 was significantly expressed in cavitary lesions. Tissue MMP-9 activity could be abrogated by specific inhibitors. In situ, three-dimensional analyses of cavitary lesions demonstrated that 22.06% of CD11b+ signal colocalized with MMP-9. C3HeB/FeJ mice represent a reliable, economical and tractable model of cavitary TB, with key similarities to human TB. This model should provide an excellent tool to better understand the pathogenesis of cavitation and its effects on TB treatments. PMID:27482816

Pharmacologic Activation of Wnt Signaling by Lithium Normalizes Retinal Vasculature in a Murine Model of Familial Exudative Vitreoretinopathy.

PubMed

Wang, Zhongxiao; Liu, Chi-Hsiu; Sun, Ye; Gong, Yan; Favazza, Tara L; Morss, Peyton C; Saba, Nicholas J; Fredrick, Thomas W; He, Xi; Akula, James D; Chen, Jing

2016-10-01

Familial exudative vitreoretinopathy (FEVR) is characterized by delayed retinal vascular development, which promotes hypoxia-induced pathologic vessels. In severe cases FEVR may lead to retinal detachment and visual impairment. Genetic studies linked FEVR with mutations in Wnt signaling ligand or receptors, including low-density lipoprotein receptor-related protein 5 (LRP5) gene. Here, we investigated ocular pathologies in a Lrp5 knockout (Lrp5(-/-)) mouse model of FEVR and explored whether treatment with a pharmacologic Wnt activator lithium could bypass the genetic defects, thereby protecting against eye pathologies. Lrp5(-/-) mice displayed significantly delayed retinal vascular development, absence of deep layer retinal vessels, leading to increased levels of vascular endothelial growth factor and subsequent pathologic glomeruloid vessels, as well as decreased inner retinal visual function. Lithium treatment in Lrp5(-/-) mice significantly restored the delayed development of retinal vasculature and the intralaminar capillary networks, suppressed formation of pathologic glomeruloid structures, and promoted hyaloid vessel regression. Moreover, lithium treatment partially rescued inner-retinal visual function and increased retinal thickness. These protective effects of lithium were largely mediated through restoration of canonical Wnt signaling in Lrp5(-/-) retina. Lithium treatment also substantially increased vascular tubular formation in LRP5-deficient endothelial cells. These findings suggest that pharmacologic activation of Wnt signaling may help treat ocular pathologies in FEVR and potentially other defective Wnt signaling-related diseases. Copyright © 2016 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.

Disease correction by AAV-mediated gene therapy in a new mouse model of mucopolysaccharidosis type IIID.

PubMed

Roca, Carles; Motas, Sandra; Marcó, Sara; Ribera, Albert; Sánchez, Víctor; Sánchez, Xavier; Bertolin, Joan; León, Xavier; Pérez, Jennifer; Garcia, Miguel; Villacampa, Pilar; Ruberte, Jesús; Pujol, Anna; Haurigot, Virginia; Bosch, Fatima

2017-04-15

Gene therapy is a promising therapeutic alternative for Lysosomal Storage Disorders (LSD), as it is not necessary to correct the genetic defect in all cells of an organ to achieve therapeutically significant levels of enzyme in body fluids, from which non-transduced cells can uptake the protein correcting their enzymatic deficiency. Animal models are instrumental in the development of new treatments for LSD. Here we report the generation of the first mouse model of the LSD Muccopolysaccharidosis Type IIID (MPSIIID), also known as Sanfilippo syndrome type D. This autosomic recessive, heparan sulphate storage disease is caused by deficiency in N-acetylglucosamine 6-sulfatase (GNS). Mice deficient in GNS showed lysosomal storage pathology and loss of lysosomal homeostasis in the CNS and peripheral tissues, chronic widespread neuroinflammation, reduced locomotor and exploratory activity and shortened lifespan, a phenotype that closely resembled human MPSIIID. Moreover, treatment of the GNS-deficient animals with GNS-encoding adeno-associated viral (AAV) vectors of serotype 9 delivered to the cerebrospinal fluid completely corrected pathological storage, improved lysosomal functionality in the CNS and somatic tissues, resolved neuroinflammation, restored normal behaviour and extended lifespan of treated mice. Hence, this work represents the first step towards the development of a treatment for MPSIIID. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Renal endoplasmic reticulum stress is coupled to impaired autophagy in a mouse model of GSD Ia.

PubMed

Farah, Benjamin L; Landau, Dustin J; Wu, Yajun; Sinha, Rohit A; Loh, Alwin; Bay, Boon-Huat; Koeberl, Dwight D; Yen, Paul M

2017-11-01

GSD Ia (von Gierke Disease, Glycogen Storage Disease Type Ia) is a devastating genetic disorder with long-term sequelae, such as non-alcoholic fatty liver disease and renal failure. Down-regulated autophagy is involved in the development of hepatic metabolic dysfunction in GSD Ia; however, the role of autophagy in the renal pathology is unknown. Here we show that autophagy is impaired and endoplasmic reticulum (ER) stress is increased in the kidneys of a mouse model of GSD Ia. Induction of autophagy by rapamycin also reduces this ER stress. Taken together, these results show an additional role for autophagy down-regulation in the pathogenesis of GSD Ia, and provide further justification for the use of autophagy modulators in GSD Ia. Copyright © 2017 Elsevier Inc. All rights reserved.

Antibody-based PET imaging of amyloid beta in mouse models of Alzheimer's disease

PubMed Central

Sehlin, Dag; Fang, Xiaotian T.; Cato, Linda; Antoni, Gunnar; Lannfelt, Lars; Syvänen, Stina

2016-01-01

Owing to their specificity and high-affinity binding, monoclonal antibodies have potential as positron emission tomography (PET) radioligands and are currently used to image various targets in peripheral organs. However, in the central nervous system, antibody uptake is limited by the blood–brain barrier (BBB). Here we present a PET ligand to be used for diagnosis and evaluation of treatment effects in Alzheimer's disease. The amyloid β (Aβ) antibody mAb158 is radiolabelled and conjugated to a transferrin receptor antibody to enable receptor-mediated transcytosis across the BBB. PET imaging of two different mouse models with Aβ pathology clearly visualize Aβ in the brain. The PET signal increases with age and correlates closely with brain Aβ levels. Thus, we demonstrate that antibody-based PET ligands can be successfully used for brain imaging. PMID:26892305

Bone Morphogenetic Protein (BMP) signaling in development and human diseases

PubMed Central

Wang, Richard N.; Green, Jordan; Wang, Zhongliang; Deng, Youlin; Qiao, Min; Peabody, Michael; Zhang, Qian; Ye, Jixing; Yan, Zhengjian; Denduluri, Sahitya; Idowu, Olumuyiwa; Li, Melissa; Shen, Christine; Hu, Alan; Haydon, Rex C.; Kang, Richard; Mok, James; Lee, Michael J.; Luu, Hue L.; Shi, Lewis L.

2014-01-01

Bone Morphogenetic Proteins (BMPs) are a group of signaling molecules that belongs to the Transforming Growth Factor-β (TGF-β) superfamily of proteins. Initially discovered for their ability to induce bone formation, BMPs are now known to play crucial roles in all organ systems. BMPs are important in embryogenesis and development, and also in maintenance of adult tissue homeostasis. Mouse knockout models of various components of the BMP signaling pathway result in embryonic lethality or marked defects, highlighting the essential functions of BMPs. In this review, we first outline the basic aspects of BMP signaling and then focus on genetically manipulated mouse knockout models that have helped elucidate the role of BMPs in development. A significant portion of this review is devoted to the prominent human pathologies associated with dysregulated BMP signaling. PMID:25401122

Resveratrol increases cerebral glycogen synthase kinase phosphorylation as well as protein levels of drebrin and transthyretin in mice: an exploratory study.

PubMed

Varamini, Behzad; Sikalidis, Angelos K; Bradford, Kathryn L

2014-02-01

Alzheimer's disease (AD) is characterized by intraneuronal β-amyloid plaques and hyperphosphorylated tau, leading to neuronal cell death and progressive memory losses. This exploratory work investigates if dietary resveratrol, previously shown to have broad anti-aging effects and improve AD pathology in vivo, leads to neuroprotective changes in specific protein targets in the mouse brain. Both wild-type and APP/PS1 mice, a transgenic AD mouse model, received control AIN-93G diet or AIN-93G supplemented with resveratrol. Pathology parameters and AD risk were assessed via measurements on plaque burden, levels of phosphorylated glycogen synthase kinase 3-β (GSK3-β), tau, transthyretin and drebrin. Dietary resveratrol treatment did not decrease plaque burden in APP/PS1 mice. However, resveratrol-fed mice demonstrated increases in GSK3-β phosphorylation, a 3.8-fold increase in protein levels of transthyretin, and a 2.2-fold increase in drebrin. This study broadens our understanding of specific mechanisms and targets whereby resveratrol provides neuroprotection.

Global loss of acetylcholinesterase activity with mitochondrial complexes inhibition and inflammation in brain of hypercholesterolemic mice.

PubMed

Paul, Rajib; Borah, Anupom

2017-12-20

There exists an intricate relationship between hypercholesterolemia (elevated plasma cholesterol) and brain functions. The present study aims to understand the impact of hypercholesterolemia on pathological consequences in mouse brain. A chronic mouse model of hypercholesterolemia was induced by giving high-cholesterol diet for 12 weeks. The hypercholesterolemic mice developed cognitive impairment as evident from object recognition memory test. Cholesterol accumulation was observed in four discrete brain regions, such as cortex, striatum, hippocampus and substantia nigra along with significantly damaged blood-brain barrier by hypercholesterolemia. The crucial finding is the loss of acetylcholinesterase activity with mitochondrial dysfunction globally in the brain of hypercholesterolemic mice, which is related to the levels of cholesterol. Moreover, the levels of hydroxyl radical were elevated in the regions of brain where the activity of mitochondrial complexes was found to be reduced. Intriguingly, elevations of inflammatory stress markers in the cholesterol-rich brain regions were observed. As cognitive impairment, diminished brain acetylcholinesterase activity, mitochondrial dysfunctions, and inflammation are the prima facie pathologies of neurodegenerative diseases, the findings impose hypercholesterolemia as potential risk factor towards brain dysfunction.

Potassium dependent rescue of a myopathy with core-like structures in mouse

PubMed Central

Hanson, M Gartz; Wilde, Jonathan J; Moreno, Rosa L; Minic, Angela D; Niswander, Lee

2015-01-01

Myopathies decrease muscle functionality. Mutations in ryanodine receptor 1 (RyR1) are often associated with myopathies with microscopic core-like structures in the muscle fiber. In this study, we identify a mouse RyR1 model in which heterozygous animals display clinical and pathological hallmarks of myopathy with core-like structures. The RyR1 mutation decreases sensitivity to activated calcium release and myoplasmic calcium levels, subsequently affecting mitochondrial calcium and ATP production. Mutant muscle shows a persistent potassium leak and disrupted expression of regulators of potassium homeostasis. Inhibition of KATP channels or increasing interstitial potassium by diet or FDA-approved drugs can reverse the muscle weakness, fatigue-like physiology and pathology. We identify regulators of potassium homeostasis as biomarkers of disease that may reveal therapeutic targets in human patients with myopathy of central core disease (CCD). Altogether, our results suggest that amelioration of potassium leaks through potassium homeostasis mechanisms may minimize muscle damage of myopathies due to certain RyR1 mutations. DOI: http://dx.doi.org/10.7554/eLife.02923.001 PMID:25564733

Progressive Pathological Changes in Neurochemical Profile of the Hippocampus and Early Changes in the Olfactory Bulbs of Tau Transgenic Mice (rTg4510).

PubMed

Kim, Jieun; Choi, In-Young; Duff, Karen E; Lee, Phil

2017-06-01

Tauopathies such as Alzheimer's disease and frontotemporal lobe degeneration (FTLD-tau) dementia, characterized by pathologic aggregation of the microtubule-associated tau protein and formation of neurofibrillary tangles, have been linked to neurodegeneration and cognitive decline. The early detection of cerebral abnormalities and the identification of biological contributors to the continuous pathologic processes of neurodegeneration in tauopathies critically hinge on sensitive and reliable measures of biomarkers in the living brain. In this study, we measured alterations in a number of key neurochemicals associated with tauopathy-induced neurodegeneration in the hippocampus and the olfactory bulbs of a transgenic mouse model of FTLD-tauopathy, line rTg4510, using in vivo 1 H magnetic resonance spectroscopy at 9.4 T. The rTg4510 line develops tauopathy at a young age (4-5 months), reaching a severe stage by 8-12 months of age. Longitudinal measurement of neurochemical concentrations in the hippocampus of mice from 5 to 12 months of age showed significant progressive changes with distinctive disease staging patterns including N-acetylaspartate, myo-inositol, γ-aminobutyric acid, glutathione and glutamine. The accompanying hippocampal volume loss measured using magnetic resonance imaging showed significant correlation (p < 0.01) with neurochemical measurements. Neurochemical alterations in the olfactory bulbs were more pronounced than those in the hippocampus in rTg4510 mice. These results demonstrate progressive neuropathology in the mouse model and provide potential biomarkers of early neuropathological events and effective noninvasive monitoring of the disease progression and treatment efficacy, which can be easily translated to clinical studies.

Recrudescent Plasmodium berghei from pregnant mice displays enhanced binding to the placenta and induces protection in multigravida.

PubMed

Marinho, Claudio R F; Neres, Rita; Epiphanio, Sabrina; Gonçalves, Lígia A; Catarino, Manuela Beirão; Penha-Gonçalves, Carlos

2009-05-20

Pregnancy-associated malaria (PAM) is associated with placenta pathology and poor pregnancy outcome but the mechanisms that control the malaria parasite expansion in pregnancy are still poorly understood and not amenable for study in human subjects. Here, we used a set of new tools to re-visit an experimental mouse model of pregnancy-induced malaria recrudescence, BALB/c with chronic Plasmodium berghei infection. During pregnancy 60% of the pre-exposed primiparous females showed pregnancy-induced malaria recrudescence and we demonstrated that the recrudescent P. berghei show an unexpected enhancement of the adherence to placenta tissue sections with a marked specificity for CSA. Furthermore, we showed that the intensity of parasitemia in primigravida was quantitatively correlated with the degree of thickening of the placental tissue and up-regulation of inflammation-related genes such as IL10. We also confirmed that the incidence of pregnancy-induced recrudescence, the intensity of the parasitemia peak and the impact on the pregnancy outcome decreased gradually from the first to the third pregnancy. Interestingly, placenta pathology and fetal impairment were also observed at low frequency among non-recrudescent females. Together, the data raise the hypothesis that recrudescent P. berghei displays selected specificity for the placenta tissue enabling on one hand, the triggering of the pathological process underlying PAM and on the other hand, the induction of PAM protection mechanisms that are revealed in subsequent pregnancies. Thus, by exploiting P. berghei pregnancy-induced recrudescence, this experimental system offers a mouse model to study the susceptibility to PAM and the mechanisms of disease protection in multigravida.

Proteomic study of differential protein expression in mouse lung tissues after aerosolized ricin poisoning.

PubMed

Guo, Zhendong; Han, Chao; Du, Jiajun; Zhao, Siyan; Fu, Yingying; Zheng, Guanyu; Sun, Yucheng; Zhang, Yi; Liu, Wensen; Wan, Jiayu; Qian, Jun; Liu, Linna

2014-04-28

Ricin is one of the most poisonous natural toxins from plants and is classified as a Class B biological threat pathogen by the Centers for Disease Control and Prevention (CDC) of U.S.A. Ricin exposure can occur through oral or aerosol routes. Ricin poisoning has a rapid onset and a short incubation period. There is no effective treatment for ricin poisoning. In this study, an aerosolized ricin-exposed mouse model was developed and the pathology was investigated. The protein expression profile in the ricin-poisoned mouse lung tissue was analyzed using proteomic techniques to determine the proteins that were closely related to the toxicity of ricin. 2D gel electrophoresis, mass spectrometry and subsequent biological functional analysis revealed that six proteins including Apoa1 apolipoprotein, Ywhaz 14-3-3 protein, Prdx6 Uncharacterized Protein, Selenium-binding protein 1, HMGB1, and DPYL-2, were highly related to ricin poisoning.

Postdoctoral Fellow | Center for Cancer Research

Cancer.gov

Dr. St. Croix’s laboratory at the Mouse Cancer Genetics Program (MCGP), National Cancer Institute, USA has an open postdoctoral position. We seek a highly motivated, creative and bright individual to participate in a collaborative project that involves the targeting of tumor-associated stroma using T-cells engineered to express chimeric antigen receptors (CARs). The laboratory focuses on the characterization and exploitation of molecules associated with tumor angiogenesis. The successful candidate would be involved in developing, producing and characterizing new therapeutic antibodies and CARs that recognize cancer cells or its associated stroma, and preclinical testing of these agents using mouse tumor models. The tumor angiogenesis lab is located at the National Cancer Institute in Frederick with access to state-of-the-art facilities for antibody engineering, genomic analysis, pathology, and small animal imaging, among others. Detailed information about Dr. St. Croix’s research and publications can be accessed at https://ccr.cancer.gov/Mouse-Cancer-Genetics-Program/brad-st-croix.

NF1 Signal Transduction and Vascular Dysfunction

DTIC Science & Technology

2015-05-01

microenvironment that promotes much of the pathology associated with the disease . Moreover we hypothesize that a mechanistic consequence of the loss...obliteration of the normal red pulp architecture. In addition, we found significant peri-aveolar and peri-vascular inflammatory infiltrates in the lung...the mouse model of NF1 disease in the endothelium we proposed and have done experiments investigating the loss of endothelial NF1 in the adult

Brain Transcriptome Profiles in Mouse Model Simulating Features of Post-traumatic Stress Disorder

DTIC Science & Technology

2015-02-28

comorbid-related signaling pathways indicate the pervasive and multisystem effects of aggressor exposure in mice, potentially mirroring the pathologic...11,12]. Impaired extinction of fear- potentiated startle and en- hanced cue conditioning in these brain regions (of trau- matized patients and animal...lead to either a long-term synap- tic potentiation (LTP) increase in synaptic strength and in- crease in excitatory post-synaptic potential

REAC technology modifies pathological neuroinflammation and motor behaviour in an Alzheimer’s disease mouse model

PubMed Central

Luca, Lorenzini; Alessandro, Giuliani; Sandra, Sivilia; Antonio, Baldassarro Vito; Mercedes, Fernandez; Matteo, Lotti Margotti; Luciana, Giardino; Vania, Fontani; Salvatore, Rinaldi; Laura, Calzà

2016-01-01

The search for new therapeutic approaches to Alzheimer disease (AD) is a major goal in medicine and society, also due to the impressive economic and social costs of this disease. In this scenario, biotechnologies play an important role. Here, it is demonstrated that the Radio Electric Asymmetric Conveyer (REAC), an innovative technology platform for neuro- and bio-modulation, used according to the neuro-regenerative protocol (RGN-N), significantly increases astroglial reaction around the amyloid plaques in an AD mouse model, as evaluated by GFAP-immunoreactivity, and reduces microglia-associated neuroinflammation markers, as evaluated by Iba1-immunoreactivity and mRNA expression level of inflammatory cytokines TREM. IL1beta, iNOS and MRC1 were not affected neither by the genotype or by REAC RGN-N treatment. Also observed was an increase in locomotion in treated animals. The study was performed in 24-month-old male Tg2576 mice and age-matching wild-type animals, tested for Y-maze, contextual fear conditioning and locomotion immediately after the end of a specific REAC treatment administered for 15 hours/day for 15 days. These results demonstrated that REAC RGN-N treatment modifies pathological neuroinflammation, and mitigates part of the complex motor behaviour alterations observed in very old Tg2576 mice. PMID:27775040

AAV9 intracerebroventricular gene therapy improves lifespan, locomotor function and pathology in a mouse model of Niemann-Pick type C1 disease.

PubMed

Hughes, Michael P; Smith, Dave A; Morris, Lauren; Fletcher, Claire; Colaco, Alexandria; Huebecker, Mylene; Tordo, Julie; Palomar, Nuria; Massaro, Giulia; Henckaerts, Els; Waddington, Simon N; Platt, Frances M; Rahim, Ahad A

2018-06-05

Niemann-Pick type C disease (NP-C) is a fatal neurodegenerative lysosomal storage disorder. It is caused in 95% of cases by a mutation in the NPC1 gene that encodes NPC1, an integral transmembrane protein localised to the limiting membrane of the lysosome. There is no cure for NP-C but there is a disease-modifying drug (miglustat) that slows disease progression but with associated side effects. Here, we demonstrate in a well-characterised mouse model of NP-C that a single administration of AAV-mediated gene therapy to the brain can significantly extend lifespan, improve quality of life, prevent or ameliorate neurodegeneration, reduce biochemical pathology and normalize or improve various indices of motor function. Over-expression of human NPC1 does not cause adverse effects in the brain and correctly localises to late endosomal/lysosomal compartments. Furthermore, we directly compare gene therapy to licensed miglustat. Even at a low dose, gene therapy has all the benefits of miglustat but without adverse effects. On the basis of these findings and on-going ascendency of the field, we propose intracerebroventricular gene therapy as a potential therapeutic option for clinical use in NP-C.

Immunotherapy alleviates amyloid-associated synaptic pathology in an Alzheimer’s disease mouse model

PubMed Central

Dorostkar, Mario M.; Burgold, Steffen; Filser, Severin; Barghorn, Stefan; Schmidt, Boris; Anumala, Upendra Rao; Hillen, Heinz; Klein, Corinna

2014-01-01

Cognitive decline in Alzheimer’s disease is attributed to loss of functional synapses, most likely caused by synaptotoxic, oligomeric forms of amyloid-β. Many treatment options aim at reducing amyloid-β levels in the brain, either by decreasing its production or by increasing its clearance. We quantified the effects of immunotherapy directed against oligomeric amyloid-β in Tg2576 mice, a mouse model of familial Alzheimer’s disease. Treatment of 12-month-old mice with oligomer-specific (A-887755) or conformation-unspecific (6G1) antibodies for 8 weeks did not affect fibrillar plaque density or growth. We also quantified densities of DLG4 (previously known as PSD95) expressing post-synapses and synapsin expressing presynapses immunohistochemically. We found that both pre- and post-synapses were strongly reduced in the vicinity of plaques, whereas distant from plaques, in the cortex and hippocampal CA1 field, only post-synapses were reduced. Immunotherapy alleviated this synapse loss. Synapse loss was completely abolished distant from plaques, whereas it was only attenuated in the vicinity of plaques. These results suggest that fibrillar plaques may act as reservoirs for synaptotoxic, oligomeric amyloid-β and that sequestering oligomers suffices to counteract synaptic pathology. Therefore, cognitive function may be improved by immunotherapy even when the load of fibrillar amyloid remains unchanged. PMID:25281869

Intraocular pressure in the smallest primate aging model: the gray mouse lemur.

PubMed

Dubicanac, Marko; Joly, Marine; Strüve, Julia; Nolte, Ingo; Mestre-Francés, Nadine; Verdier, Jean-Michel; Zimmermann, Elke

2018-05-01

The aim of this study was to assess the practicability of common tonometers used in veterinary medicine for rapid intraocular pressure (IOP) screening, to calibrate IOP values gained by the tonometers, and to define a reference IOP value for the healthy eye in a new primate model for aging research, the gray mouse lemur. TonoVet ® and the TonoPen ™ measurements were calibrated manometrically in healthy enucleated eyes of mouse lemurs euthanized for veterinary reasons. For comparison of the practicability of both tonometers as a rapid IOP assessment tool for living mouse lemurs, the IOP of 24 eyes of 12 animals held in the hand was measured. To define a standard reference value for IOP in mouse lemurs, 258 healthy animals were measured using the TonoVet ® . Intraocular pressure measurements for the TonoVet ® can be corrected using the formula: y = 0.981 + (1.962*TonoVet ® value), and those for the TonoPen ™ using that of y = 5.38 + (1.426*TonoPen ™ value). The calibrated IOP for a healthy mouse lemur eye was 20.3 ± 2.8 mmHg. The TonoVet ® showed advantages in practicability, for example, small corneal contact area, short and painless corneal contact, shortened total time spent on investigation, as well as the more accurate measured values. IOP measurements of healthy mouse lemur eyes were not affected by age, sex, eye side, or colony. Tonometry using TonoVet ® is the more practicable assessment tool for IOP measurement of the tiny eyes of living mouse lemurs. Pathological deviations can be identified based on the described reference value. © 2016 American College of Veterinary Ophthalmologists.

Mutation of EpCAM leads to intestinal barrier and ion transport dysfunction.

PubMed

Kozan, Philip A; McGeough, Matthew D; Peña, Carla A; Mueller, James L; Barrett, Kim E; Marchelletta, Ronald R; Sivagnanam, Mamata

2015-05-01

Congenital tufting enteropathy (CTE) is a devastating diarrheal disease seen in infancy that is typically associated with villous changes and the appearance of epithelial tufts. We previously found mutations in epithelial cell adhesion molecule (EpCAM) to be causative in CTE. We developed a knock-down cell model of CTE through transfection of an EpCAM shRNA construct into T84 colonic epithelial cells to elucidate the in vitro role of EpCAM in barrier function and ion transport. Cells with EpCAM deficiency exhibited decreased electrical resistance, increased permeability, and decreased ion transport. Based on mutations in CTE patients, an in vivo mouse model was developed, with tamoxifen-inducible deletion of exon 4 in Epcam resulting in mutant protein with decreased expression. Tamoxifen treatment of Epcam (Δ4/Δ4) mice resulted in pathological features of villous atrophy and epithelial tufts, similar to those in human CTE patients, within 4 days post induction. Epcam (Δ4/Δ4) mice also showed decreased expression of tight junctional proteins, increased permeability, and decreased ion transport in the intestines. Taken together, these findings reveal mechanisms that may underlie disease in CTE. Knock-down EpCAM cell model of congenital tufting enteropathy was developed. In vivo inducible mouse model was developed resulting in mutant EpCAM protein. Cells with EpCAM deficiency demonstrated barrier and ion transport dysfunction. Tamoxifen-treated Epcam (Δ4/Δ4) mice demonstrated pathological features. Epcam (Δ4/Δ4) mice showed improper barrier function and ion transport.

Review on the APP/PS1KI mouse model: intraneuronal Abeta accumulation triggers axonopathy, neuron loss and working memory impairment.

PubMed

Bayer, T A; Wirths, O

2008-02-01

Accumulating evidence points to an important role of intraneuronal Abeta as a trigger of the pathological cascade of events leading to neurodegeneration and eventually to Alzheimer's disease (AD) with its typical clinical symptoms, like memory impairment and change in personality. As a new concept, intraneuronal accumulation of Abeta instead of extracellular Abeta deposition has been introduced to be the disease-triggering event in AD. The present review compiles current knowledge on the amyloid precursor protein (APP)/PS1KI mouse model with early and massive intraneuronal Abeta42 accumulation: (1) The APP/PS1KI mouse model exhibits early robust brain and spinal cord axonal degeneration and hippocampal CA1 neuron loss. (2) At the same time-point, a dramatic, age-dependent reduced ability to perform working memory and motor tasks is observed. (3) The APP/PS1KI mice are smaller and show development of a thoracolumbar kyphosis, together with an incremental loss of body weight. (4) Onset of the observed behavioral alterations correlates well with robust axonal degeneration in brain and spinal cord and with abundant hippocampal CA1 neuron loss.

The Synergistic Beneficial Effects of Ginkgo Flavonoid and Coriolus versicolor Polysaccharide for Memory Improvements in a Mouse Model of Dementia.

PubMed

Fang, Xianying; Jiang, Yan; Ji, Hui; Zhao, Linguo; Xiao, Wei; Wang, Zhenzhong; Ding, Gang

2015-01-01

This study reports the combination of Ginkgo flavonoid (GF) and Coriolus versicolor polysaccharide (CVP) in the prevention and treatment of a mouse model of Alzheimer's disease (AD). GF is a traditional health product, and CVP is the main active ingredient of the medicinal fungus Coriolus versicolor. The Morris water maze test, the Y maze, and the step-through test showed that the combinational use of CVP and GF synergistically improved memory in a mouse model of AD. Based on H&E staining analysis, the combination of CVP and GF decreased the severity of the pathological findings in the brain. Given that the expression of IL-1β, IL-6, and TNF-α was downregulated, the inflammation response in AD mice was considered to be inhibited. The downregulation of GFAP further demonstrated that inflammation was reduced in the brain of AD mice following treatment. Moreover, the expression levels of superoxide dismutase (SOD) and catalase (CAT) were elevated in the brains of treated mice, indicating that oxidation levels were reduced upon the combination treatment. Our results provide new insights into the efficient utilization of traditional medicine for preventing dementia.

The Synergistic Beneficial Effects of Ginkgo Flavonoid and Coriolus versicolor Polysaccharide for Memory Improvements in a Mouse Model of Dementia

PubMed Central

Fang, Xianying; Jiang, Yan; Ji, Hui; Xiao, Wei; Wang, Zhenzhong; Ding, Gang

2015-01-01

This study reports the combination of Ginkgo flavonoid (GF) and Coriolus versicolor polysaccharide (CVP) in the prevention and treatment of a mouse model of Alzheimer's disease (AD). GF is a traditional health product, and CVP is the main active ingredient of the medicinal fungus Coriolus versicolor. The Morris water maze test, the Y maze, and the step-through test showed that the combinational use of CVP and GF synergistically improved memory in a mouse model of AD. Based on H&E staining analysis, the combination of CVP and GF decreased the severity of the pathological findings in the brain. Given that the expression of IL-1β, IL-6, and TNF-α was downregulated, the inflammation response in AD mice was considered to be inhibited. The downregulation of GFAP further demonstrated that inflammation was reduced in the brain of AD mice following treatment. Moreover, the expression levels of superoxide dismutase (SOD) and catalase (CAT) were elevated in the brains of treated mice, indicating that oxidation levels were reduced upon the combination treatment. Our results provide new insights into the efficient utilization of traditional medicine for preventing dementia. PMID:25821476

Pleiotrophin and N-syndecan promote perineural invasion and tumor progression in an orthotopic mouse model of pancreatic cancer.

PubMed

Yao, Jun; Zhang, Lu-Lin; Huang, Xu-Mei; Li, Wen-Yao; Gao, She-Gan

2017-06-07

To detect the expression of pleiotrophin (PTN) and N-syndecan in pancreatic cancer and analyze their association with tumor progression and perineural invasion (PNI). An orthotopic mouse model of pancreatic cancer was created by injecting tumor cells subcapsularly in a root region of the pancreas beneath the spleen. Pancreatic cancer tissues were taken from 36 mice that survived for more than 90 d. PTN and N-syndecan proteins were detected by immunohistochemistry and analyzed for their correlation with pathological features, PNI, and prognosis. The expression rates of PTN and N-syndecan proteins were 66.7% and 61.1%, respectively, in cancer tissue. PTN and N-syndecan expression was associated with PNI ( P = 0.019 and P = 0.032, respectively). High PTN expression was closely associated with large bloody ascites ( P = 0.009), liver metastasis ( P = 0.035), and decreased survival time ( P = 0.022). N-syndecan expression was significantly associated with tumor size ( P = 0.025), but not with survival time ( P = 0.539). High PTN and N-syndecan expression was closely associated with metastasis and poor prognosis, suggesting that they may promote tumor progression and PNI in the orthotopic mouse model of pancreatic cancer.

Mouse cursor movement and eye tracking data as an indicator of pathologists’ attention when viewing digital whole slide images

PubMed Central

Raghunath, Vignesh; Braxton, Melissa O.; Gagnon, Stephanie A.; Brunyé, Tad T.; Allison, Kimberly H.; Reisch, Lisa M.; Weaver, Donald L.; Elmore, Joann G.; Shapiro, Linda G.

2012-01-01

Context: Digital pathology has the potential to dramatically alter the way pathologists work, yet little is known about pathologists’ viewing behavior while interpreting digital whole slide images. While tracking pathologist eye movements when viewing digital slides may be the most direct method of capturing pathologists’ viewing strategies, this technique is cumbersome and technically challenging to use in remote settings. Tracking pathologist mouse cursor movements may serve as a practical method of studying digital slide interpretation, and mouse cursor data may illuminate pathologists’ viewing strategies and time expenditures in their interpretive workflow. Aims: To evaluate the utility of mouse cursor movement data, in addition to eye-tracking data, in studying pathologists’ attention and viewing behavior. Settings and Design: Pathologists (N = 7) viewed 10 digital whole slide images of breast tissue that were selected using a random stratified sampling technique to include a range of breast pathology diagnoses (benign/atypia, carcinoma in situ, and invasive breast cancer). A panel of three expert breast pathologists established a consensus diagnosis for each case using a modified Delphi approach. Materials and Methods: Participants’ foveal vision was tracked using SensoMotoric Instruments RED 60 Hz eye-tracking system. Mouse cursor movement was tracked using a custom MATLAB script. Statistical Analysis Used: Data on eye-gaze and mouse cursor position were gathered at fixed intervals and analyzed using distance comparisons and regression analyses by slide diagnosis and pathologist expertise. Pathologists’ accuracy (defined as percent agreement with the expert consensus diagnoses) and efficiency (accuracy and speed) were also analyzed. Results: Mean viewing time per slide was 75.2 seconds (SD = 38.42). Accuracy (percent agreement with expert consensus) by diagnosis type was: 83% (benign/atypia); 48% (carcinoma in situ); and 93% (invasive). Spatial coupling was close between eye-gaze and mouse cursor positions (highest frequency ∆x was 4.00px (SD = 16.10), and ∆y was 37.50px (SD = 28.08)). Mouse cursor position moderately predicted eye gaze patterns (Rx = 0.33 and Ry = 0.21). Conclusions: Data detailing mouse cursor movements may be a useful addition to future studies of pathologists’ accuracy and efficiency when using digital pathology. PMID:23372984

Mouse cursor movement and eye tracking data as an indicator of pathologists' attention when viewing digital whole slide images.

PubMed

Raghunath, Vignesh; Braxton, Melissa O; Gagnon, Stephanie A; Brunyé, Tad T; Allison, Kimberly H; Reisch, Lisa M; Weaver, Donald L; Elmore, Joann G; Shapiro, Linda G

2012-01-01

Digital pathology has the potential to dramatically alter the way pathologists work, yet little is known about pathologists' viewing behavior while interpreting digital whole slide images. While tracking pathologist eye movements when viewing digital slides may be the most direct method of capturing pathologists' viewing strategies, this technique is cumbersome and technically challenging to use in remote settings. Tracking pathologist mouse cursor movements may serve as a practical method of studying digital slide interpretation, and mouse cursor data may illuminate pathologists' viewing strategies and time expenditures in their interpretive workflow. To evaluate the utility of mouse cursor movement data, in addition to eye-tracking data, in studying pathologists' attention and viewing behavior. Pathologists (N = 7) viewed 10 digital whole slide images of breast tissue that were selected using a random stratified sampling technique to include a range of breast pathology diagnoses (benign/atypia, carcinoma in situ, and invasive breast cancer). A panel of three expert breast pathologists established a consensus diagnosis for each case using a modified Delphi approach. Participants' foveal vision was tracked using SensoMotoric Instruments RED 60 Hz eye-tracking system. Mouse cursor movement was tracked using a custom MATLAB script. Data on eye-gaze and mouse cursor position were gathered at fixed intervals and analyzed using distance comparisons and regression analyses by slide diagnosis and pathologist expertise. Pathologists' accuracy (defined as percent agreement with the expert consensus diagnoses) and efficiency (accuracy and speed) were also analyzed. Mean viewing time per slide was 75.2 seconds (SD = 38.42). Accuracy (percent agreement with expert consensus) by diagnosis type was: 83% (benign/atypia); 48% (carcinoma in situ); and 93% (invasive). Spatial coupling was close between eye-gaze and mouse cursor positions (highest frequency ∆x was 4.00px (SD = 16.10), and ∆y was 37.50px (SD = 28.08)). Mouse cursor position moderately predicted eye gaze patterns (Rx = 0.33 and Ry = 0.21). Data detailing mouse cursor movements may be a useful addition to future studies of pathologists' accuracy and efficiency when using digital pathology.

3D culture models of Alzheimer's disease: a road map to a "cure-in-a-dish".

PubMed

Choi, Se Hoon; Kim, Young Hye; Quinti, Luisa; Tanzi, Rudolph E; Kim, Doo Yeon

2016-12-09

Alzheimer's disease (AD) transgenic mice have been used as a standard AD model for basic mechanistic studies and drug discovery. These mouse models showed symbolic AD pathologies including β-amyloid (Aβ) plaques, gliosis and memory deficits but failed to fully recapitulate AD pathogenic cascades including robust phospho tau (p-tau) accumulation, clear neurofibrillary tangles (NFTs) and neurodegeneration, solely driven by familial AD (FAD) mutation(s). Recent advances in human stem cell and three-dimensional (3D) culture technologies made it possible to generate novel 3D neural cell culture models that recapitulate AD pathologies including robust Aβ deposition and Aβ-driven NFT-like tau pathology. These new 3D human cell culture models of AD hold a promise for a novel platform that can be used for mechanism studies in human brain-like environment and high-throughput drug screening (HTS). In this review, we will summarize the current progress in recapitulating AD pathogenic cascades in human neural cell culture models using AD patient-derived induced pluripotent stem cells (iPSCs) or genetically modified human stem cell lines. We will also explain how new 3D culture technologies were applied to accelerate Aβ and p-tau pathologies in human neural cell cultures, as compared the standard two-dimensional (2D) culture conditions. Finally, we will discuss a potential impact of the human 3D human neural cell culture models on the AD drug-development process. These revolutionary 3D culture models of AD will contribute to accelerate the discovery of novel AD drugs.

Pseudoxanthoma elasticum is a metabolic disease.

PubMed

Jiang, Qiujie; Endo, Masayuki; Dibra, Florian; Wang, Krystle; Uitto, Jouni

2009-02-01

Pseudoxanthoma elasticum (PXE) is a pleiotropic multisystem disorder affecting skin, eyes, and the cardiovascular system with progressive pathological mineralization. It is caused by mutations in the ABCC6 gene expressed primarily in the liver and kidneys, and at very low levels, if at all, in tissues affected by PXE. A question has arisen regarding the pathomechanism of PXE, particularly the "metabolic" versus the "PXE cell" hypotheses. We examined a murine PXE model (Abcc6(-/-)) by transplanting muzzle skin from knockout (KO) and wild-type (WT) mice onto the back of WT and KO mice using mineralization of the connective tissue capsule surrounding the vibrissae as an early phenotypic biomarker. Grafting of WT mouse muzzle skin onto the back of KO mice resulted in mineralization of vibrissae, whereas grafting KO mouse muzzle skin onto WT mice did not. Thus, these findings implicate circulatory factors as a critical component of the mineralization process. This mouse grafting model supports the notion that PXE is a systemic metabolic disorder with secondary mineralization of connective tissues and that the mineralization process can be countered or even reversed by changes in the homeostatic milieu.

T1, diffusion tensor, and quantitative magnetization transfer imaging of the hippocampus in an Alzheimer's disease mouse model.

PubMed

Whittaker, Heather T; Zhu, Shenghua; Di Curzio, Domenico L; Buist, Richard; Li, Xin-Min; Noy, Suzanna; Wiseman, Frances K; Thiessen, Jonathan D; Martin, Melanie

2018-07-01

Alzheimer's disease (AD) pathology causes microstructural changes in the brain. These changes, if quantified with magnetic resonance imaging (MRI), could be studied for use as an early biomarker for AD. The aim of our study was to determine if T 1 relaxation, diffusion tensor imaging (DTI), and quantitative magnetization transfer imaging (qMTI) metrics could reveal changes within the hippocampus and surrounding white matter structures in ex vivo transgenic mouse brains overexpressing human amyloid precursor protein with the Swedish mutation. Delineation of hippocampal cell layers using DTI color maps allows more detailed analysis of T 1 -weighted imaging, DTI, and qMTI metrics, compared with segmentation of gross anatomy based on relaxation images, and with analysis of DTI or qMTI metrics alone. These alterations are observed in the absence of robust intracellular Aβ accumulation or plaque deposition as revealed by histology. This work demonstrates that multiparametric quantitative MRI methods are useful for characterizing changes within the hippocampal substructures and surrounding white matter tracts of mouse models of AD. Copyright © 2018. Published by Elsevier Inc.

Proceedings of the 2013 Joint JSTP/NTP Satellite Symposium

PubMed Central

Elmore, Susan A.; Hoenerhoff, Mark; Katsuta, Osamu; Kokoshima, Hiroko; Maronpot, Robert; Nagai, Hiroaki; Satoh, Hiroshi; Tanaka, Yasuhiro; Tochitani, Tomoaki; Tsuchiya, Seiichiro; Yoshizawa, Katsuhiko

2013-01-01

The first joint Japanese Society of Toxicologic Pathology (JSTP) and National Toxicology Program (NTP) Satellite Symposium, entitled “Pathology Potpourri,” was held on January 29th at Okura Frontier Hotel in Tsukuba, Ibaraki, Japan, in advance of the JSTP’s 29th Annual Meeting. The goal of this Symposium was to present current diagnostic pathology or nomenclature issues to the toxicologic pathology community. This article presents summaries of the speakers’ presentations, including diagnostic or nomenclature issues that were presented, select images that were used for audience voting or discussion, and the voting results. Some lesions and topics covered during the symposium include: treatment-related atypical hepatocellular foci of cellular alteration in B6C3F1 mice; purulent ventriculoencephalitis in a young BALB/c mouse; a subcutaneous malignant schwannoma in a RccHan:WIST rat; spontaneous nasal septum hyalinosis/eosinophilic substance in B6C3F1 mice; a rare pancreatic ductal cell adenoma in a young Lewis rat; eosinophilic crystalline pneumonia in a transgenic mouse model; hyaline glomerulopathy in two female ddY mice; treatment-related intrahepatic erythrocytes in B6C3F1 mice; treatment-related subendothelial hepatocytes in B6C3F1 mice; spontaneous thyroid follicular cell vacuolar degeneration in a cynomolgus monkey; congenital hepatic fibrosis in a 1-year-old cat; a spontaneous adenocarcinoma of the middle ear in a young Crl:CD(SD) rat; and finally a series of cases illustrating some differences between cholangiofibrosis and cholangiocarcinoma in Sprague Dawley and F344 rats. PMID:23914068

Peripheral denervation participates in heterotopic ossification in a spinal cord injury model

PubMed Central

Salga, Marjorie; Begot, Laurent; Holy, Xavier; Chedik, Malha; de l’Escalopier, Nicolas; Torossian, Fréderic; Levesque, Jean-Pierre; Lataillade, Jean-Jacques; Le Bousse-Kerdilès, Marie-Caroline; Genêt, François

2017-01-01

We previously reported the development of a new acquired neurogenic HO (NHO) mouse model, combining spinal cord transection (SCI) and chemical muscle injury. Pathological mechanisms responsible for ectopic osteogenesis after central neurological damage are still to be elucidated. In this study, we first hypothesized that peripheral nervous system (PNS) might convey pathological signals from injured spinal cord to muscles in NHO mouse model. Secondly, we sought to determine whether SCI could lead to intramuscular modifications of BMP2 signaling pathways. Twenty one C57Bl6 mice were included in this protocol. Bilateral cardiotoxin (CTX) injection in hamstring muscles was associated with a two-stage surgical procedure, combining thoracic SCI with unilateral peripheral denervation. Volumes of HO (Bone Volume, BV) were measured 28 days after surgery using micro-computed tomography imaging techniques and histological analyses were made to confirm intramuscular osteogenesis. Volume comparisons were conducted between right and left hind limb of each animal, using a Wilcoxon signed rank test. Quantitative polymerase chain reaction (qPCR) was performed to explore intra muscular expression of BMP2, Alk3 and Id1. Nineteen mice survive the complete SCI and peripheral denervation procedure. When CTX injections were done right after surgery (n = 7), bilateral HO were detected in all animals after 28 days. Micro-CT measurements showed significantly increased BV in denervated paws (1.47 mm3 +/- 0.5) compared to contralateral sides (0.56 mm3 +/-0.4), p = 0.03. When peripheral denervation and CTX injections were performed after sham SCI surgery (n = 6), bilateral HO were present in three mice at day 28. Quantitative PCR analyses showed no changes in intra muscular BMP2 expression after SCI as compared to control mice (shamSCI). Peripheral denervation can be reliably added to spinal cord transection in NHO mouse model. This new experimental design confirms that neuro inflammatory mechanisms induced by central or peripheral nervous system injury plays a key role in triggering ectopic osteogenesis. PMID:28854256

Tannic Acid Is a Natural β-Secretase Inhibitor That Prevents Cognitive Impairment and Mitigates Alzheimer-like Pathology in Transgenic Mice*

PubMed Central

Mori, Takashi; Rezai-Zadeh, Kavon; Koyama, Naoki; Arendash, Gary W.; Yamaguchi, Haruyasu; Kakuda, Nobuto; Horikoshi-Sakuraba, Yuko; Tan, Jun; Town, Terrence

2012-01-01

Amyloid precursor protein (APP) proteolysis is essential for production of amyloid-β (Aβ) peptides that form β-amyloid plaques in brains of Alzheimer disease (AD) patients. Recent focus has been directed toward a group of naturally occurring anti-amyloidogenic polyphenols known as flavonoids. We orally administered the flavonoid tannic acid (TA) to the transgenic PSAPP mouse model of cerebral amyloidosis (bearing mutant human APP and presenilin-1 transgenes) and evaluated cognitive function and AD-like pathology. Consumption of TA for 6 months prevented transgene-associated behavioral impairment including hyperactivity, decreased object recognition, and defective spatial reference memory, but did not alter nontransgenic mouse behavior. Accordingly, brain parenchymal and cerebral vascular β-amyloid deposits and abundance of various Aβ species including oligomers were mitigated in TA-treated PSAPP mice. These effects occurred with decreased cleavage of the β-carboxyl-terminal APP fragment, lowered soluble APP-β production, reduced β-site APP cleaving enzyme 1 protein stability and activity, and attenuated neuroinflammation. As in vitro validation, we treated well characterized mutant human APP-overexpressing murine neuron-like cells with TA and found significantly reduced Aβ production associated with less amyloidogenic APP proteolysis. Taken together, these results raise the possibility that dietary supplementation with TA may be prophylactic for AD by inhibiting β-secretase activity and neuroinflammation and thereby mitigating AD pathology. PMID:22219198

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

Tau Pathology Induces Excitatory Neuron Loss, Grid Cell Dysfunction and Spatial Memory Deficits Reminiscent of Early Alzheimer's Disease

PubMed Central

Fu, Hongjun; Rodriguez, Gustavo A.; Herman, Mathieu; Emrani, Sheina; Nahmani, Eden; Barrett, Geoffrey; Figueroa, Helen Y.; Goldberg, Eliana

2017-01-01

Summary The earliest stages of Alzheimer's disease (AD) are characterized by the formation of mature tangles in the entorhinal cortex and disorientation and confusion navigating familiar places. The medial entorhinal cortex (MEC) contains specialized neurons called grid cells that form part of the spatial navigation system. Here we show in a transgenic mouse model expressing mutant human tau predominantly in the EC that the formation of mature tangles in old mice was associated with excitatory cell loss and deficits in grid cell function, including destabilized grid fields and reduced firing rates, as well as altered network activity. Overt tau pathology in the aged mice was accompanied by spatial memory deficits. Therefore, tau pathology initiated in the entorhinal cortex could lead to deficits in grid cell firing and underlie the deterioration of spatial cognition seen in human AD. PMID:28111080

Effects of Acanthopanax senticosus on Brain Injury Induced by Simulated Spatial Radiation in Mouse Model Based on Pharmacokinetics and Comparative Proteomics

PubMed Central

Cheng, Cuilin; Baranenko, Denis; Wang, Jiaping; Li, Yongzhi; Lu, Weihong

2018-01-01

The active compounds in Acanthopanax senticosus (AS) have different pharmacokinetic characteristics in mouse models. Cmax and AUC of Acanthopanax senticosus polysaccharides (ASPS) were significantly reduced in radiation-injured mice, suggesting that the blood flow of mouse was blocked or slowed, due to the pathological state of ischemia and hypoxia, which are caused by radiation. In contrast, the ability of various metabolizing enzymes to inactivate, capacity of biofilm transport decrease, and lessening of renal blood flow accounts for radiation, resulting in the accumulation of syringin and eleutheroside E in the irradiated mouse. Therefore, there were higher pharmacokinetic parameters—AUC, MRT, and t1/2 of the two compounds in radiation-injured mouse, when compared with normal mouse. In order to investigate the intrinsic mechanism of AS on radiation injury, AS extract’s protective effects on brain, the main part of mouse that suffered from radiation, were explored. The function of AS extract in repressing expression changes of radiation response proteins in prefrontal cortex (PFC) of mouse brain included tubulin protein family (α-, β-tubulin subunits), dihydropyrimidinase-related protein 2 (CRMP2), γ-actin, 14-3-3 protein family (14-3-3ζ, ε), heat shock protein 90β (HSP90β), and enolase 2. The results demonstrated the AS extract had positive effects on nerve cells’ structure, adhesion, locomotion, fission, and phagocytosis, through regulating various action pathways, such as Hippo, phagosome, PI3K/Akt (phosphatidylinositol 3 kinase/protein kinase B), Neurotrophin, Rap1 (Ras-related protein RAP-1A), gap junction glycolysis/gluconeogenesis, and HIF-1 (Hypoxia-inducible factor 1) signaling pathways to maintain normal mouse neurological activity. All of the results indicated that AS may be a promising alternative medicine for the treatment of radiation injury in mouse brain. It would be tested that whether the bioactive ingredients of AS could be effective through the blood–brain barrier in the future. PMID:29342911

The proof-of-concept of ASS234: Peripherally administered ASS234 enters the central nervous system and reduces pathology in a male mouse model of Alzheimer disease

PubMed Central

Serrano, Mari Paz; Herrero-Labrador, Raquel; Futch, Hunter S.; Serrano, Julia; Romero, Alejandro; Fernandez, Ana Patricia; Samadi, Abdelouahid; Unzeta, Mercedes; Marco-Contelles, Jose; Martínez-Murillo, Ricardo

2017-01-01

Background The heterogeneity of Alzheimer disease requires the development of multitarget drugs for treating the symptoms of the disease and its progression. Both cholinergic and monoamine oxidase dysfunctions are involved in the pathological process. Thus, we hypothesized that the development of therapies focused on these targets might be effective. We have developed and assessed a new product, coded ASS234, a multipotent acetyl and butyrylcholinesterase/monoamine oxidase A–B inhibitor with a potent inhibitory effect on amyloid-β aggregation as well as antioxidant and antiapoptotic properties. But there is a need to reliably correlate in vitro and in vivo drug release data. Methods We examined the effect of ASS234 on cognition in healthy adult C57BL/6J mice in a model of scopolamine-induced cognitive impairment that often accompanies normal and pathological aging. Also, in a characterized transgenic APPswe/PS1ΔE9 mouse model of Alzheimer disease, we examined the effects of short-term ASS234 treatment on plaque deposition and gliosis using immunohistochemistry. Toxicology of ASS234 was assessed using a quantitative high-throughput in vitro cytotoxicity screening assay following the MTT assay method in HepG2 liver cells. Results In vivo, ASS234 significantly decreased scopolamine-induced learning deficits in C57BL/6J mice. Also, reduction of amyloid plaque burden and gliosis in the cortex and hippocampus was assessed. In vitro, ASS234 exhibited lesser toxicity than donepezil and tacrine. Limitations The study was conducted in male mice only. Although the Alzheimer disease model does not recapitulate all features of the human disease, it exhibits progressive monoaminergic neurodegeneration. Conclusion ASS234 is a promising alternative drug of choice to treat the cognitive decline and neurodegeneration underlying Alzheimer disease. PMID:27636528

Toward Distinguishing Recurrent Tumor From Radiation Necrosis: DWI and MTC in a Gamma Knife–Irradiated Mouse Glioma Model

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

Perez-Torres, Carlos J.; Engelbach, John A.; Cates, Jeremy

Purpose: Accurate noninvasive diagnosis is vital for effective treatment planning. Presently, standard anatomical magnetic resonance imaging (MRI) is incapable of differentiating recurring tumor from delayed radiation injury, as both lesions are hyperintense in both postcontrast T1- and T2-weighted images. Further studies are therefore necessary to identify an MRI paradigm that can differentially diagnose these pathologies. Mouse glioma and radiation injury models provide a powerful platform for this purpose. Methods and Materials: Two MRI contrasts that are widely used in the clinic were chosen for application to a glioma/radiation-injury model: diffusion weighted imaging, from which the apparent diffusion coefficient (ADC) ismore » obtained, and magnetization transfer contrast, from which the magnetization transfer ratio (MTR) is obtained. These metrics were evaluated longitudinally, first in each lesion type alone–glioma versus irradiation – and then in a combined irradiated glioma model. Results: MTR was found to be consistently decreased in all lesions compared to nonlesion brain tissue (contralateral hemisphere), with limited specificity between lesion types. In contrast, ADC, though less sensitive to the presence of pathology, was increased in radiation injury and decreased in tumors. In the irradiated glioma model, ADC also increased immediately after irradiation, but decreased as the tumor regrew. Conclusions: ADC is a better metric than MTR for differentiating glioma from radiation injury. However, MTR was more sensitive to both tumor and radiation injury than ADC, suggesting a possible role in detecting lesions that do not enhance strongly on T1-weighted images.« less

Anti-inflammatory effects of Boletus edulis polysaccharide on asthma pathology.

PubMed

Wu, Songquan; Wang, Guangli; Yang, Ruhui; Cui, Yubao

2016-01-01

Asthma is a chronic airway disease common around the world. The burden of this disease could be reduced with new and effective treatments. Here, the efficacy of a polysaccharide extract from the Boletus edulis (BEP) mushroom, which has demonstrated anti-inflammatory properties, was tested in a mouse model of asthma. Five groups of BaLB/C mice were developed; one group served as a control and did not have asthma induction. The other four groups of mice were sensitized by ovalbumin challenge. FinePointe™ RC animal airway resistance and pulmonary compliance was used to assess airway function in asthma models. Three of the 4 model groups received treatments: one received pravastatin, one received dexamethasone, and one received BEP. Histopathology of lung tissues was performed using H&E and AB-PAS staining. Levels of cytokines IL-4 and IFN-g were detected using ELISA, qRT-PCR, and Western blotting. Cyclophilin A was measured by Western blot, and flow cytometry was used to determine the proportion of CD4 + CD25 + FOXP3 + Treg cells. BEP treatment resulted in improvements in lung pathology, IL-4 level (P<0.05), and IFN-γ level (P<0.05) similar to traditional dexamethasone treatment. Further, the proportion of anti-inflammatory CD4 + CD25 + FOXP3 + Treg cells significantly increased (P<0.05) compared to untreated asthma models, and expression of cyclophilin A significantly decreased (P<0.05). Thus, Boletus edulis polysaccharide reduces pro-inflammatory responses and increases anti-inflammatory responses in mouse models of asthma, suggesting this may be a novel treatment method.

Anti-inflammatory effects of Boletus edulis polysaccharide on asthma pathology

PubMed Central

Wu, Songquan; Wang, Guangli; Yang, Ruhui; Cui, Yubao

2016-01-01

Asthma is a chronic airway disease common around the world. The burden of this disease could be reduced with new and effective treatments. Here, the efficacy of a polysaccharide extract from the Boletus edulis (BEP) mushroom, which has demonstrated anti-inflammatory properties, was tested in a mouse model of asthma. Five groups of BaLB/C mice were developed; one group served as a control and did not have asthma induction. The other four groups of mice were sensitized by ovalbumin challenge. FinePointe™ RC animal airway resistance and pulmonary compliance was used to assess airway function in asthma models. Three of the 4 model groups received treatments: one received pravastatin, one received dexamethasone, and one received BEP. Histopathology of lung tissues was performed using H&E and AB-PAS staining. Levels of cytokines IL-4 and IFN-g were detected using ELISA, qRT-PCR, and Western blotting. Cyclophilin A was measured by Western blot, and flow cytometry was used to determine the proportion of CD4+CD25+FOXP3+ Treg cells. BEP treatment resulted in improvements in lung pathology, IL-4 level (P<0.05), and IFN-γ level (P<0.05) similar to traditional dexamethasone treatment. Further, the proportion of anti-inflammatory CD4+CD25+FOXP3+ Treg cells significantly increased (P<0.05) compared to untreated asthma models, and expression of cyclophilin A significantly decreased (P<0.05). Thus, Boletus edulis polysaccharide reduces pro-inflammatory responses and increases anti-inflammatory responses in mouse models of asthma, suggesting this may be a novel treatment method. PMID:27830033

Tissue tropisms, infection kinetics, histologic lesions, and antibody response of the MR766 strain of Zika virus in a murine model.

PubMed

Kawiecki, Anna B; Mayton, E Handly; Dutuze, M Fausta; Goupil, Brad A; Langohr, Ingeborg M; Del Piero, Fabio; Christofferson, Rebecca C

2017-04-18

The appearance of severe Zika virus (ZIKV) disease in the most recent outbreak has prompted researchers to respond through the development of tools to quickly characterize transmission and pathology. We describe here another such tool, a mouse model of ZIKV infection and pathogenesis using the MR766 strain of virus that adds to the growing body of knowledge regarding ZIKV kinetics in small animal models. We infected mice with the MR766 strain of ZIKV to determine infection kinetics via serum viremia. We further evaluated infection-induced lesions via histopathology and visualized viral antigen via immunohistochemical labeling. We also investigated the antibody response of recovered animals to both the MR766 and a strain from the current outbreak (PRVABC59). We demonstrate that the IRF3/7 DKO mouse is a susceptible, mostly non-lethal model well suited for the study of infection kinetics, pathological progression, and antibody response. Infected mice presented lesions in tissues that have been associated with ZIKV infection in the human population, such as the eyes, male gonads, and central nervous system. In addition, we demonstrate that infection with the MR766 strain produces cross-neutralizing antibodies to the PRVABC59 strain of the Asian lineage. This model provides an additional tool for future studies into the transmission routes of ZIKV, as well as for the development of antivirals and other therapeutics, and should be included in the growing list of available tools for investigations of ZIKV infection and pathogenesis.

Dermal Collagen and Lipid Deposition Correlate with Tissue Swelling and Hydraulic Conductivity in Murine Primary Lymphedema

PubMed Central

Rutkowski, Joseph M.; Markhus, Carl Erik; Gyenge, Christina C.; Alitalo, Kari; Wiig, Helge; Swartz, Melody A.

2010-01-01

Primary lymphedema is a congenital pathology of dysfunctional lymphatic drainage characterized by swelling of the limbs, thickening of the dermis, and fluid and lipid accumulation in the underlying tissue. Two mouse models of primary lymphedema, the Chy mouse and the K14-VEGFR-3-Ig mouse, both lack dermal lymphatic capillaries and exhibit a lymphedematous phenotype attributable to disrupted VEGFR-3 signaling. Here we show that the differences in edematous tissue composition between these two models correlated with drastic differences in hydraulic conductivity. The skin of Chy mice possessed significantly higher levels of collagen and fat, whereas K14-VEGFR-3-Ig mouse skin composition was relatively normal, as compared with their respective wild-type controls. Functionally, this resulted in a greatly increased dermal hydraulic conductivity in K14-VEGFR3-Ig, but not Chy, mice. Our data suggest that lymphedema associated with increased collagen and lipid accumulation counteracts an increased hydraulic conductivity associated with dermal swelling, which in turn further limits interstitial transport and swelling. Without lipid and collagen accumulation, hydraulic conductivity is increased and overall swelling is minimized. These opposing tissue responses to primary lymphedema imply that tissue remodeling—predominantly collagen and fat deposition—may dictate tissue swelling and govern interstitial transport in lymphedema. PMID:20110415

Dermal collagen and lipid deposition correlate with tissue swelling and hydraulic conductivity in murine primary lymphedema.

PubMed

Rutkowski, Joseph M; Markhus, Carl Erik; Gyenge, Christina C; Alitalo, Kari; Wiig, Helge; Swartz, Melody A

2010-03-01

Primary lymphedema is a congenital pathology of dysfunctional lymphatic drainage characterized by swelling of the limbs, thickening of the dermis, and fluid and lipid accumulation in the underlying tissue. Two mouse models of primary lymphedema, the Chy mouse and the K14-VEGFR-3-Ig mouse, both lack dermal lymphatic capillaries and exhibit a lymphedematous phenotype attributable to disrupted VEGFR-3 signaling. Here we show that the differences in edematous tissue composition between these two models correlated with drastic differences in hydraulic conductivity. The skin of Chy mice possessed significantly higher levels of collagen and fat, whereas K14-VEGFR-3-Ig mouse skin composition was relatively normal, as compared with their respective wild-type controls. Functionally, this resulted in a greatly increased dermal hydraulic conductivity in K14-VEGFR3-Ig, but not Chy, mice. Our data suggest that lymphedema associated with increased collagen and lipid accumulation counteracts an increased hydraulic conductivity associated with dermal swelling, which in turn further limits interstitial transport and swelling. Without lipid and collagen accumulation, hydraulic conductivity is increased and overall swelling is minimized. These opposing tissue responses to primary lymphedema imply that tissue remodeling--predominantly collagen and fat deposition--may dictate tissue swelling and govern interstitial transport in lymphedema.

A clinically authentic mouse model of enterovirus 71 (EV-A71)-induced neurogenic pulmonary oedema.

PubMed

Victorio, Carla Bianca Luena; Xu, Yishi; Ng, Qimei; Chua, Beng Hooi; Alonso, Sylvie; Chow, Vincent T K; Chua, Kaw Bing

2016-06-30

Enterovirus 71 (EV-A71) is a neurotropic virus that sporadically causes fatal neurologic illness among infected children. Animal models of EV-A71 infection exist, but they do not recapitulate in animals the spectrum of disease and pathology observed in fatal human cases. Specifically, neurogenic pulmonary oedema (NPE)-the main cause of EV-A71 infection-related mortality-is not observed in any of these models. This limits their utility in understanding viral pathogenesis of neurologic infections. We report the development of a mouse model of EV-A71 infection displaying NPE in severely affected animals. We inoculated one-week-old BALB/c mice with an adapted EV-A71 strain and identified clinical signs consistent with observations in human cases and other animal models. We also observed respiratory distress in some mice. At necropsy, we found their lungs to be heavier and incompletely collapsed compared to other mice. Serum levels of catecholamines and histopathology of lung and brain tissues of these mice strongly indicated onset of NPE. The localization of virally-induced brain lesions also suggested a potential pathogenic mechanism for EV-A71-induced NPE. This novel mouse model of virally-induced NPE represents a valuable resource for studying viral mechanisms of neuro-pathogenesis and pre-clinical testing of potential therapeutics and prophylactics against EV-A71-related neurologic complications.

A Mouse Model of Acinetobacter baumannii-Associated Pneumonia Using a Clinically Isolated Hypervirulent Strain

PubMed Central

Harris, Greg; Kuo Lee, Rhonda; Lam, Christopher K.; Kanzaki, Gregory; Patel, Girishchandra B.; Xu, H. Howard

2013-01-01

Acinetobacter baumannii is an important emerging pathogen in health care-acquired infections and is responsible for severe nosocomial and community-acquired pneumonia. Currently available mouse models of A. baumannii pneumonia show poor colonization with little to no extrapulmonary dissemination. Here, we describe a mouse model of A. baumannii pneumonia using a clinical isolate (LAC-4 strain) that reliably reproduces the most relevant features of human pulmonary A. baumannii infection and pathology. Using this model, we have shown that LAC-4 infection induced rapid bacterial replication in the lungs, significant extrapulmonary dissemination, and severe bacteremia by 24 h postintranasal inoculation. Infected mice showed severe bronchopneumonia and dilatation and inflammatory cell infiltration in the perivascular space. More significantly, 100% of C57BL/6 and BALB/c mice succumbed to 108 CFU of LAC-4 inoculation within 48 h. When this model was used to assess the efficacy of antimicrobials, all mice treated with imipenem and tigecycline survived a lethal intranasal challenge, with minimal clinical signs and body weight loss. Moreover, intranasal immunization of mice with formalin-fixed LAC-4 protected 40% of mice from a lethal (100× 100% lethal dose) intraperitoneal challenge. Thus, this model offers a reproducible acute course of A. baumannii pneumonia without requiring additional manipulation of host immune status, which will facilitate the development of therapeutic agents and vaccines against A. baumannii pneumonia in humans. PMID:23689726

Contribution of Dysferlin Deficiency to Skeletal Muscle Pathology in Asymptomatic and Severe Dystroglycanopathy Models: Generation of a New Model for Fukuyama Congenital Muscular Dystrophy

PubMed Central

Kanagawa, Motoi; Lu, Zhongpeng; Ito, Chiyomi; Matsuda, Chie; Miyake, Katsuya; Toda, Tatsushi

2014-01-01

Defects in dystroglycan glycosylation are associated with a group of muscular dystrophies, termed dystroglycanopathies, that include Fukuyama congenital muscular dystrophy (FCMD). It is widely believed that abnormal glycosylation of dystroglycan leads to disease-causing membrane fragility. We previously generated knock-in mice carrying a founder retrotransposal insertion in fukutin, the gene responsible for FCMD, but these mice did not develop muscular dystrophy, which hindered exploring therapeutic strategies. We hypothesized that dysferlin functions may contribute to muscle cell viability in the knock-in mice; however, pathological interactions between glycosylation abnormalities and dysferlin defects remain unexplored. To investigate contributions of dysferlin deficiency to the pathology of dystroglycanopathy, we have crossed dysferlin-deficient dysferlin sjl/sjl mice to the fukutin-knock-in fukutin Hp/− and Large-deficient Large myd/myd mice, which are phenotypically distinct models of dystroglycanopathy. The fukutin Hp/− mice do not show a dystrophic phenotype; however, (dysferlin sjl/sjl: fukutin Hp/−) mice showed a deteriorated phenotype compared with (dysferlin sjl/sjl: fukutin Hp/+) mice. These data indicate that the absence of functional dysferlin in the asymptomatic fukutin Hp/− mice triggers disease manifestation and aggravates the dystrophic phenotype. A series of pathological analyses using double mutant mice for Large and dysferlin indicate that the protective effects of dysferlin appear diminished when the dystrophic pathology is severe and also may depend on the amount of dysferlin proteins. Together, our results show that dysferlin exerts protective effects on the fukutin Hp/− FCMD mouse model, and the (dysferlin sjl/sjl: fukutin Hp/−) mice will be useful as a novel model for a recently proposed antisense oligonucleotide therapy for FCMD. PMID:25198651

Overexpression of mouse TTF-2 gene causes cleft palate

PubMed Central

Meng, Tian; Shi, Jia-Yu; Wu, Min; Wang, Yan; Li, Ling; Liu, Yan; Zheng, Qian; Huang, Lei; Shi, Bing

2012-01-01

In humans, mutations of the gene encoding for thyroid transcription factor-2 (TTF-2 or FOXE1) result in Bamforth syndrome. Bamforth syndrome is characterized by agenesis, cleft palate, spiky hair and choanal atresia. TTF-2 null mice (TTF-2−/−) also exhibit cleft palate, suggesting its involvement in the palatogenesis. However, the molecular pathology and genetic regulation by TTF2 remain largely unknown. In the present study, the recombinant expression vector pBROAD3-TTF-2 containing the promoter of the mouse ROSA26 gene was created to form the structural gene of mouse TTF-2 and was microinjected into the male pronuclei of fertilized ova. Sequence analysis confirmed that the TTF-2 transgenic mouse model was established successfully. The transgenic mice displayed a phenotype of cleft palate. In addition, we found that TTF-2 was highly expressed in the medial edge epithelium (MEE) from the embryonic day 12.5 (E12.5) to E14.5 in TTF-2 transgenic mice. These observations suggest that overexpression of TTF-2 during palatogenesis may contribute to formation of cleft palate. PMID:22304410

Nuclear Receptors in Neurodegenerative Diseases

PubMed Central

Skerrett, Rebecca; Malm, Tarja; Landreth, Gary

2014-01-01

Nuclear receptors have generated substantial interest in the past decade as potential therapeutic targets for the treatment of neurodegenerative disorders. Despite years of effort, effective treatments for progressive neurodegenerative diseases such as Alzheimer’s disease, Parkinson’s disease, Huntington’s disease and ALS remain elusive, making non-classical drug targets such as nuclear receptors an attractive alternative. A substantial literature in mouse models of disease and several clinical trials have investigated the role of nuclear receptors in various neurodegenerative disorders, most prominently AD. These studies have met with mixed results, yet the majority of studies in mouse models report positive outcomes. The mechanisms by which nuclear receptor agonists affect disease pathology remain unclear. Deciphering the complex signaling underlying nuclear receptor action in neurodegenerative diseases is essential for understanding this variability in preclinical studies, and for the successful translation of nuclear receptor agonists into clinical therapies. PMID:24874548

Muscle stem cell dysfunction impairs muscle regeneration in a mouse model of Down syndrome.

PubMed

Pawlikowski, Bradley; Betta, Nicole Dalla; Elston, Tiffany; Williams, Darian A; Olwin, Bradley B

2018-03-09

Down syndrome, caused by trisomy 21, is characterized by a variety of medical conditions including intellectual impairments, cardiovascular defects, blood cell disorders and pre-mature aging phenotypes. Several somatic stem cell populations are dysfunctional in Down syndrome and their deficiencies may contribute to multiple Down syndrome phenotypes. Down syndrome is associated with muscle weakness but skeletal muscle stem cells or satellite cells in Down syndrome have not been investigated. We find that a failure in satellite cell expansion impairs muscle regeneration in the Ts65Dn mouse model of Down syndrome. Ts65Dn satellite cells accumulate DNA damage and over express Usp16, a histone de-ubiquitinating enzyme that regulates the DNA damage response. Impairment of satellite cell function, which further declines as Ts65Dn mice age, underscores stem cell deficiencies as an important contributor to Down syndrome pathologies.

mTOR inhibition alleviates mitochondrial disease in a mouse model of Leigh syndrome.

PubMed

Johnson, Simon C; Yanos, Melana E; Kayser, Ernst-Bernhard; Quintana, Albert; Sangesland, Maya; Castanza, Anthony; Uhde, Lauren; Hui, Jessica; Wall, Valerie Z; Gagnidze, Arni; Oh, Kelly; Wasko, Brian M; Ramos, Fresnida J; Palmiter, Richard D; Rabinovitch, Peter S; Morgan, Philip G; Sedensky, Margaret M; Kaeberlein, Matt

2013-12-20

Mitochondrial dysfunction contributes to numerous health problems, including neurological and muscular degeneration, cardiomyopathies, cancer, diabetes, and pathologies of aging. Severe mitochondrial defects can result in childhood disorders such as Leigh syndrome, for which there are no effective therapies. We found that rapamycin, a specific inhibitor of the mechanistic target of rapamycin (mTOR) signaling pathway, robustly enhances survival and attenuates disease progression in a mouse model of Leigh syndrome. Administration of rapamycin to these mice, which are deficient in the mitochondrial respiratory chain subunit Ndufs4 [NADH dehydrogenase (ubiquinone) Fe-S protein 4], delays onset of neurological symptoms, reduces neuroinflammation, and prevents brain lesions. Although the precise mechanism of rescue remains to be determined, rapamycin induces a metabolic shift toward amino acid catabolism and away from glycolysis, alleviating the buildup of glycolytic intermediates. This therapeutic strategy may prove relevant for a broad range of mitochondrial diseases.

Brain-resident memory CD8+ T cells induced by congenital CMV infection prevent brain pathology and virus reactivation.

PubMed

Brizić, Ilija; Šušak, Božo; Arapović, Maja; Huszthy, Peter C; Hiršl, Lea; Kveštak, Daria; Juranić Lisnić, Vanda; Golemac, Mijo; Pernjak Pugel, Ester; Tomac, Jelena; Oxenius, Annette; Britt, William J; Arapović, Jurica; Krmpotić, Astrid; Jonjić, Stipan

2018-06-01

Congenital HCMV infection is a leading infectious cause of long-term neurodevelopmental sequelae. Infection of newborn mice with mouse cytomegalovirus (MCMV) intraperitoneally is a well-established model of congenital human cytomegalovirus infection, which best recapitulates the hematogenous route of virus spread to brain and subsequent pathology. Here, we used this model to investigate the role, dynamics, and phenotype of CD8 + T cells in the brain following infection of newborn mice. We show that CD8 + T cells infiltrate the brain and form a pool of tissue-resident memory T cells (T RM cells) that persist for lifetime. Adoptively transferred virus-specific CD8 + T cells provide protection against primary MCMV infection in newborn mice, reduce brain pathology, and remain in the brain as T RM cells. Brain CD8 + T RM cells were long-lived, slowly proliferating cells able to respond to local challenge infection. Importantly, brain CD8 + T RM cells controlled latent MCMV and their depletion resulted in virus reactivation and enhanced inflammation in brain. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Retinal Ultrastructure of Murine Models of Dry Age-related Macular Degeneration (AMD)

PubMed Central

Ramkumar, Hema L.; Zhang, Jun; Chan, Chi-Chao

2010-01-01

Age-related macular degeneration (AMD) is the most prevalent form of irreversible blindness worldwide in the elderly population. The pathology of dry AMD consists of degeneration of photoreceptors and the RPE, lipofuscin (A2E) accumulation, and drusen formation. Mice have been widely used for generating models that simulate human AMD features for investigating the pathogenesis, treatment and prevention of the disease. Although the mouse has no macula, focal atrophy of photorecptors and RPE, lipofuscin accumulation, and increased A2E can develop in aged mouse eyes. However, drusen are rarely seen in mice because of their simpler Bruch’s membrane and different process of lipofuscin extrusion compared with humans. Thus, analyzing basal deposits at the ultrastructural level and understanding the ultrastructural pathologic differences between various mouse AMD models are critical to comprehending the significance of research findings and response to possible therapeutic options for dry AMD. Based on the multifactorial pathogenesis of AMD, murine dry AMD models can be classified into three groups. First, genetically engineered mice that target genes related to juvenile macular dystrophies are the most common models, and they include abcr−/− (Stargardt disease), transgenic ELOVL4 (Stargardt-3 dominant inheritary disease), Efemp1R345W/R345W (Doyne honeycomb retinal dystrophy), and Timp3S156C/S156C (Sorsby fundus dystrophy) mice. Other murine models target genes relevant to AMD, including inflammatory genes such as Cfh−/−, Ccl2−/−, Ccr2−/−, Cx3cr1−/−, and Ccl2−/−/cx3cr1−/−, oxidative stress associated genes such as Sod1−/− and Sod2 knockdown, metabolic pathway genes such as neprilysin −/− (amyloid β), transgenic mcd/mcd (cathepsin D), Cp−/−/Heph−/Y (ferroxidase ceruloplasmin/hepaestin, iron metabolism), and transgenic ApoE4 on high fat and high cholesterol diet (lipid metabolism). Second, mice have also been immunologically manipulated by immunization with carboxyethylpyrrole (CEP), an oxidative fragment of DHA found in drusen, and found to present with dry AMD features. Third, natural mouse strains such as arrd2/arrd2 (Mdm gene mutation) and the senescence accelerated mice (SAM) spontaneously develop features of dry AMD like photoreceptor atrophy and thickening of Bruch’s membrane. All the aforementioned models develop retinal lesions with various features that simulate dry AMD lesions: focal photoreceptor degeneration, abnormal RPE with increased lipofuscin, basal infolding, decreased melanosomes and degeneration. However, Bruch’s membrane changes are less common. Most mice develop retinal lesions at an older age (6–24 months, depending on the models), while the Ccl2−/−/cx3cr1−/− mice develop lesions by 4–6 weeks. Although murine models present various degrees of retinal and/or RPE degeneration, classical drusen is extremely rare. Using electron microscopy, small drusenoid deposits are found between RPE and Bruch’s membrane in a few models including Efemp1 R345W/R345W, Ccl2−/−/cx3cr1−/−, neprilysin −/−, transgenic mcd/mcd, and ApoE4 transgenic mice on a high fat diet. High A2E levels are measured in the retinas of abcr−/−, transgenic ELOVL4, and Ccl2−/−/cx3cr1−/− mice. In summary, murine models provide useful tools for studying AMD pathogenesis and evaluating novel therapies for this disease. This review compares the major dry AMD murine models and discusses retinal pathology at the ultrastructural level. PMID:20206286

Multiscale multimodal fusion of histological and MRI volumes for characterization of lung inflammation

NASA Astrophysics Data System (ADS)

Rusu, Mirabela; Wang, Haibo; Golden, Thea; Gow, Andrew; Madabhushi, Anant

2013-03-01

Mouse lung models facilitate the investigation of conditions such as chronic inflammation which are associated with common lung diseases. The multi-scale manifestation of lung inflammation prompted us to use multi-scale imaging - both in vivo, ex vivo MRI along with ex vivo histology, for its study in a new quantitative way. Some imaging modalities, such as MRI, are non-invasive and capture macroscopic features of the pathology, while others, e.g. ex vivo histology, depict detailed structures. Registering such multi-modal data to the same spatial coordinates will allow the construction of a comprehensive 3D model to enable the multi-scale study of diseases. Moreover, it may facilitate the identification and definition of quantitative of in vivo imaging signatures for diseases and pathologic processes. We introduce a quantitative, image analytic framework to integrate in vivo MR images of the entire mouse with ex vivo histology of the lung alone, using lung ex vivo MRI as conduit to facilitate their co-registration. In our framework, we first align the MR images by registering the in vivo and ex vivo MRI of the lung using an interactive rigid registration approach. Then we reconstruct the 3D volume of the ex vivo histological specimen by efficient group wise registration of the 2D slices. The resulting 3D histologic volume is subsequently registered to the MRI volumes by interactive rigid registration, directly to the ex vivo MRI, and implicitly to in vivo MRI. Qualitative evaluation of the registration framework was performed by comparing airway tree structures in ex vivo MRI and ex vivo histology where airways are visible and may be annotated. We present a use case for evaluation of our co-registration framework in the context of studying chronic inammation in a diseased mouse.

Two-photon microscopy for real-time monitoring of focused ultrasound-mediated drug delivery to the brain in a mouse model of Alzheimer's disease

NASA Astrophysics Data System (ADS)

Burgess, Alison; Eterman, Naomi; Aubert, Isabelle; Hynynen, Kullervo

2013-02-01

There is substantial evidence that focused ultrasound (FUS) in combination with microbubble contrast agent can cause disruption of the blood-brain barrier (BBB) to aid in drug delivery to the brain. We have previously demonstrated that FUS efficiently delivers antibodies against amyloid-β peptides (Aβ) through the BBB, leading to a reduction in amyloid pathology at 4 days in a mouse model of Alzheimer's disease. In the current study, we used two-photon microscopy to characterize the effect of FUS in real time on amyloid pathology in the mouse brain. Mice were anesthetized and a cranial window was made in the skull. A custom-built ultrasound transducer was fixed to a coverslip and attached to the skull, covering the cranial window. Methoxy-X04 [2-5mg/kg] delivered intravenously 1 hr prior to the experiment clearly labelled the Aβ surrounding the vessels and the amyloid plaques in the cortex. Dextran conjugated Texas Red (70kDa) administered intravenously, confirmed BBB disruption. BBB disruption occurred in transgenic and non-transgenic animals at similar ultrasound pressures tested. However, the time required for BBB closure following FUS was longer in the Tg mice. We have conjugated Aβ antibodies to the fluorescent molecule FITC for real time monitoring of the antibody distribution in the brain. Our current experiments are aimed at optimizing the parameters to achieve maximal fluorescent intensity of the BAM10 antibody at the plaque surface. Two-photon microscopy has proven to be a valuable tool for evaluating the efficacy of FUS mediated drug delivery, including antibodies, to the Alzheimer brain.

Experimental malaria-associated acute respiratory distress syndrome is dependent on the parasite-host combination and coincides with normocyte invasion.

PubMed

Vandermosten, Leen; Pham, Thao-Thy; Possemiers, Hendrik; Knoops, Sofie; Van Herck, Evelien; Deckers, Julie; Franke-Fayard, Blandine; Lamb, Tracey J; Janse, Chris J; Opdenakker, Ghislain; Van den Steen, Philippe E

2018-03-05

Malaria-associated acute respiratory distress syndrome (MA-ARDS) is a complication of malaria with a lethality rate of up to 80% despite anti-malarial treatment. It is characterized by a vast infiltration of leukocytes, microhaemorrhages and vasogenic oedema in the lungs. Previously, a mouse model for MA-ARDS was developed by infection of C57BL/6 mice with the Edinburgh line NK65-E of Plasmodium berghei. Here, both host and parasite factors were demonstrated to play crucial roles in the development and severity of lung pathology. In particular, the genetic constitution of the host was an important determinant in the development of MA-ARDS. Both male and female C57BL/6, but not BALB/c, mice developed MA-ARDS when infected with P. berghei NK65-E. However, the New York line of P. berghei NK65 (NK65-NY) did not induce demonstrable MA-ARDS, despite its accumulation in the lungs and fat tissue to a similar or even higher extent as P. berghei NK65-E. These two commonly used lines of P. berghei differ in their red blood cell preference. P. berghei NK65-NY showed a stronger predilection for reticulocytes than P. berghei NK65-E and this appeared to be associated with a lower pathogenicity in the lungs. The pulmonary pathology in the C57BL/6/P. berghei NK65-E model was more pronounced than in the model with infection of DBA/2 mice with P. berghei strain ANKA. The transient lung pathology in DBA/2 mice infected with P. berghei ANKA coincided with the infection phase in which parasites mainly infected normocytes. This phase was followed by a less pathogenic phase in which P. berghei ANKA mainly infected reticulocytes. The propensity of mice to develop MA-ARDS during P. berghei infection depends on both host and parasite factors and appears to correlate with RBC preference. These data provide insights in induction of MA-ARDS and may guide the choice of different mouse-parasite combinations to study lung pathology.

Human Effector Memory T Helper Cells Engage with Mouse Macrophages and Cause Graft-versus-Host-Like Pathology in Skin of Humanized Mice Used in a Nonclinical Immunization Study.

PubMed

Sundarasetty, Balasai; Volk, Valery; Theobald, Sebastian J; Rittinghausen, Susanne; Schaudien, Dirk; Neuhaus, Vanessa; Figueiredo, Constanca; Schneider, Andreas; Gerasch, Laura; Mucci, Adele; Moritz, Thomas; von Kaisenberg, Constantin; Spineli, Loukia M; Sewald, Katherina; Braun, Armin; Weigt, Henning; Ganser, Arnold; Stripecke, Renata

2017-06-01

Humanized mice engrafted with human hematopoietic stem cells and developing functional human T-cell adaptive responses are in critical demand to test human-specific therapeutics. We previously showed that humanized mice immunized with long-lived induced-dendritic cells loaded with the pp65 viral antigen (iDCpp65) exhibited a faster development and maturation of T cells. Herein, we evaluated these effects in a long-term (36 weeks) nonclinical model using two stem cell donors to assess efficacy and safety. Relative to baseline, iDCpp65 immunization boosted the output of effector memory CD4 + T cells in peripheral blood and lymph nodes. No weight loss, human malignancies, or systemic graft-versus-host (GVH) disease were observed. However, for one reconstitution cohort, some mice immunized with iDCpp65 showed GVH-like signs on the skin. Histopathology analyses of the inflamed skin revealed intrafollicular and perifollicular human CD4 + cells near F4/80 + mouse macrophages around hair follicles. In spleen, CD4 + cells formed large clusters surrounded by mouse macrophages. In plasma, high levels of human T helper 2-type inflammatory cytokines were detectable, which activated in vitro the STAT5 pathway of murine macrophages. Despite this inflammatory pattern, human CD8 + T cells from mice with GVH reacted against the pp65 antigen in vitro. These results uncover a dynamic cross-species interaction between human memory T cells and mouse macrophages in the skin and lymphatic tissues of humanized mice. Copyright © 2017 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.

Reduction of Nuak1 Decreases Tau and Reverses Phenotypes in a Tauopathy Mouse Model.

PubMed

Lasagna-Reeves, Cristian A; de Haro, Maria; Hao, Shuang; Park, Jeehye; Rousseaux, Maxime W C; Al-Ramahi, Ismael; Jafar-Nejad, Paymaan; Vilanova-Velez, Luis; See, Lauren; De Maio, Antonia; Nitschke, Larissa; Wu, Zhenyu; Troncoso, Juan C; Westbrook, Thomas F; Tang, Jianrong; Botas, Juan; Zoghbi, Huda Y

2016-10-19

Many neurodegenerative proteinopathies share a common pathogenic mechanism: the abnormal accumulation of disease-related proteins. As growing evidence indicates that reducing the steady-state levels of disease-causing proteins mitigates neurodegeneration in animal models, we developed a strategy to screen for genes that decrease the levels of tau, whose accumulation contributes to the pathology of both Alzheimer disease (AD) and progressive supranuclear palsy (PSP). Integrating parallel cell-based and Drosophila genetic screens, we discovered that tau levels are regulated by Nuak1, an AMPK-related kinase. Nuak1 stabilizes tau by phosphorylation specifically at Ser356. Inhibition of Nuak1 in fruit flies suppressed neurodegeneration in tau-expressing Drosophila, and Nuak1 haploinsufficiency rescued the phenotypes of a tauopathy mouse model. These results demonstrate that decreasing total tau levels is a valid strategy for mitigating tau-related neurodegeneration and reveal Nuak1 to be a novel therapeutic entry point for tauopathies. Copyright © 2016 Elsevier Inc. All rights reserved.

[A simple and efficient method for establishing a mouse model of orthotopic MB49 bladder cancer].

PubMed

Liang, Zhong-kun; Zhang, Lin; Hu, Zhi-ming; Chen, Zhong; Huang, Xin; Shi, Xiang-hua; Tan, Wan-long; Gao, Ji-min

2009-04-01

To establish a simple and efficient method for establishing a mouse model of orthotopic superficial bladder cancer. C57BL/6 mice were anesthetized with sodium pentobarbital and catheterized with modified IV catheter (24 G). The mice were intravesically pretreated with HCl and then with NaOH, and after washing the bladders with phosphate-buffered saline (PBS), 100 microl (1 x 10(7)) MB49 cells were infused and allowed to incubate in the bladder for 2 h followed intravesical mitomycin C (MMC) administration. The tumor formation rate, survival, gross hematuria, and bladder weight were determined as the outcome variables, and the pathology of the bladders was observed. Instillation of MB49 tumor cells resulted in a tumor formation rates of 100% in all the pretreated groups while 0% in the control group without pretreatment. MMC significantly reduced the bladder weight as compared to PBS. We have successfully established a stable, reproducible, and reliable orthotopic bladder cancer model in mice.

Mouse Models of Escherichia coli O157:H7 Infection and Shiga Toxin Injection

PubMed Central

Mohawk, Krystle L.; O'Brien, Alison D.

2011-01-01

Escherichia coli O157:H7 has been responsible for multiple food- and waterborne outbreaks of diarrhea and/or hemorrhagic colitis (HC) worldwide. More importantly, a portion of E. coli O157:H7-infected individuals, particularly young children, develop a life-threatening sequela of infection called hemolytic uremic syndrome (HUS). Shiga toxin (Stx), a potent cytotoxin, is the major virulence factor linked to the presentation of both HC and HUS. Currently, treatment of E. coli O157:H7 and other Stx-producing E. coli (STEC) infections is limited to supportive care. To facilitate development of therapeutic strategies and vaccines for humans against these agents, animal models that mimic one or more aspect of STEC infection and disease are needed. In this paper, we focus on the characteristics of various mouse models that have been developed and that can be used to monitor STEC colonization, disease, pathology, or combinations of these features as well as the impact of Stx alone. PMID:21274267

The Gne M712T mouse as a model for human glomerulopathy.

PubMed

Kakani, Sravan; Yardeni, Tal; Poling, Justin; Ciccone, Carla; Niethamer, Terren; Klootwijk, Enriko D; Manoli, Irini; Darvish, Daniel; Hoogstraten-Miller, Shelley; Zerfas, Patricia; Tian, E; Ten Hagen, Kelly G; Kopp, Jeffrey B; Gahl, William A; Huizing, Marjan

2012-04-01

Pathological glomerular hyposialylation has been implicated in certain unexplained glomerulopathies, including minimal change nephrosis, membranous glomerulonephritis, and IgA nephropathy. We studied our previously established mouse model carrying a homozygous mutation in the key enzyme of sialic acid biosynthesis, N-acetylglucosamine 2-epimerase/N-acetylmannosamine kinase. Mutant mice died before postnatal day 3 (P3) from severe glomerulopathy with podocyte effacement and segmental glomerular basement membrane splitting due to hyposialylation. Administration of the sialic acid precursor N-acetylmannosamine (ManNAc) led to improved sialylation and survival of mutant pups beyond P3. We determined the onset of the glomerulopathy in the embryonic stage. A lectin panel, distinguishing normally sialylated from hyposialylated glycans, used WGA, SNA, PNA, Jacalin, HPA, and VVA, indicating glomerular hyposialylation of predominantly O-linked glycoproteins in mutant mice. The glomerular glycoproteins nephrin and podocalyxin were hyposialylated in this unique murine model. ManNAc treatment appeared to ameliorate the hyposialylation status of mutant mice, indicated by a lectin histochemistry pattern similar to that of wild-type mice, with improved sialylation of both nephrin and podocalyxin, as well as reduced albuminuria compared with untreated mutant mice. These findings suggest application of our lectin panel for categorizing human kidney specimens based on glomerular sialylation status. Moreover, the partial restoration of glomerular architecture in ManNAc-treated mice highlights ManNAc as a potential treatment for humans affected with disorders of glomerular hyposialylation. Copyright © 2012 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.

Increased protein kinase C gamma activity induces Purkinje cell pathology in a mouse model of spinocerebellar ataxia 14.

PubMed

Ji, Jingmin; Hassler, Melanie L; Shimobayashi, Etsuko; Paka, Nagendher; Streit, Raphael; Kapfhammer, Josef P

2014-10-01

Spinocerebellar ataxias (SCAs) are hereditary diseases leading to Purkinje cell degeneration and cerebellar dysfunction. Most forms of SCA are caused by expansion of CAG repeats similar to other polyglutamine disorders such as Huntington's disease. In contrast, in the autosomal dominant SCA-14 the disease is caused by mutations in the protein kinase C gamma (PKCγ) gene which is a well characterized signaling molecule in cerebellar Purkinje cells. The study of SCA-14, therefore, offers the unique opportunity to reveal the molecular and pathological mechanism eventually leading to Purkinje cell dysfunction and degeneration. We have created a mouse model of SCA-14 in which PKCγ protein with a mutation found in SCA-14 is specifically expressed in cerebellar Purkinje cells. We find that in mice expressing the mutated PKCγ protein the morphology of Purkinje cells in cerebellar slice cultures is drastically altered and mimics closely the morphology seen after pharmacological PKC activation. Similar morphological abnormalities were seen in localized areas of the cerebellum of juvenile transgenic mice in vivo. In adult transgenic mice there is evidence for some localized loss of Purkinje cells but there is no overall cerebellar atrophy. Transgenic mice show a mild cerebellar ataxia revealed by testing on the rotarod and on the walking beam. Our findings provide evidence for both an increased PKCγ activity in Purkinje cells in vivo and for pathological changes typical for cerebellar disease thus linking the increased and dysregulated activity of PKCγ tightly to the development of cerebellar disease in SCA-14 and possibly also in other forms of SCA. Copyright © 2014 Elsevier Inc. All rights reserved.

Ischaemia-reperfusion injury in orthotopic mouse lung transplants - a scanning electron microscopy study.

PubMed

Draenert, Alice; Marquardt, Klaus; Inci, Ilhan; Soltermann, Alex; Weder, Walter; Jungraithmayr, Wolfgang

2011-02-01

Lung ischaemia-reperfusion (I/R) injury remains a major cause of graft failure in lung transplantation (Tx). With the implementation of orthotopic lung Tx in mice, a physiological model on the base of a perfused and ventilated graft became available for the investigation of I/R injury. Using the scanning electron microscopy (SEM) technique, we here present an analysis of early and late morphological changes of pulmonary I/R injury. Syngeneic lungs were orthotopically transplanted between C57BL/6 mice. Grafts were exposed to 2 h of cold ischaemia. Transplants and right lungs were examined by SEM with corresponding haematoxylin-eosin histology 30 min and 4 h after reperfusion. Thirty minutes after reperfusion, the alveolar surface of transplants showed a discontinued lining of surfactant, while the lining of the non-transplanted lung was normal. Within the graft, leucocytes displayed an irregular surface with development of pseudopodia, and microvilli were detected on the membrane of pneumocytes. At 4 h after reperfusion, leucocytes significantly increased in numbers within the alveolar space. Also, the number of microvilli on pneumocytes increased significantly. Similar to these, the endothelium of vessels increasingly developed microvilli from 30 min towards 4 h after reperfusion. The airways of transplanted grafts showed mild changes with thickening of the bronchial epithelium and a destruction of kinocilia. Taken together, SEM detects pathological events of I/R that are previously not described in normal histology. These findings may influence the interpretation of studies investigating the I/R injury in the mouse model of lung Tx. © 2011 The Authors. International Journal of Experimental Pathology © 2011 International Journal of Experimental Pathology.

Mid-life environmental enrichment increases synaptic density in CA1 in a mouse model of Aβ-associated pathology and positively influences synaptic and cognitive health in healthy ageing.

PubMed

Stuart, Kimberley E; King, Anna E; Fernandez-Martos, Carmen M; Dittmann, Justin; Summers, Mathew J; Vickers, James C

2017-06-01

Early-life cognitive enrichment may reduce the risk of experiencing cognitive deterioration and dementia in later-life. However, an intervention to prevent or delay dementia is likely to be taken up in mid to later-life. Hence, we investigated the effects of environmental enrichment in wildtype mice and in a mouse model of Aβ neuropathology (APP SWE /PS1 dE9 ) from 6 months of age. After 6 months of housing in standard laboratory cages, APP SWE /PS1 dE9 (n = 27) and healthy wildtype (n = 21) mice were randomly assigned to either enriched or standard housing. At 12 months of age, wildtype mice showed altered synaptic protein levels and relatively superior cognitive performance afforded by environmental enrichment. Environmental enrichment was not associated with alterations to Aβ plaque pathology in the neocortex or hippocampus of APP SWE /PS1 dE9 mice. However, a significant increase in synaptophysin immunolabeled puncta in the hippocampal subregion, CA1, in APP SWE /PS1 dE9 mice was detected, with no significant synaptic density changes observed in CA3, or the Fr2 region of the prefrontal cortex. Moreover, a significant increase in hippocampal BDNF was detected in APP SWE /PS1 dE9 mice exposed to EE, however, no changes were detected in neocortex or between Wt animals. These results demonstrate that mid to later-life cognitive enrichment has the potential to promote synaptic and cognitive health in ageing, and to enhance compensatory capacity for synaptic connectivity in pathological ageing associated with Aβ deposition. © 2017 Wiley Periodicals, Inc.

Dexmedetomidine attenuates pancreatic injury and inflammatory response in mice with pancreatitis by possible reduction of NLRP3 activation and up-regulation of NET expression.

PubMed

Li, Yong; Pan, Yiyuan; Gao, Lin; Lu, Guotao; Zhang, Jingzhu; Xie, Xiaochun; Tong, Zhihui; Li, Baiqiang; Li, Gang; Li, Weiqin

2018-01-22

Previous studies have shown that acute inflammation is associated with increased sympathetic activity, which in turn increases the inflammatory response and leads to organ damage. The present study aimed to investigate whether dexmedetomidine administration during acute pancreatitis (AP) lessens pancreatic pathological and functional injury and the inflammatory response, and to explore the underlying mechanisms. Mild pancreatitis was induced in mice with caerulein, and severe pancreatitis was induced with caerulein plus lipopolysaccharide (LPS). After pancreatitis induction, dexmedetomidine at 10 or 20 μg/kg was injected via the tail vein. Pancreatic pathological and functional injury was assessed by histology and serum levels of amylase and lipase, respectively. The inflammatory response was evaluated by determining serum levels of inflammatory factors. The expression of myeloperoxidase (MPO) was examined by immunohistochemistry. The expression of norepinephrine transporter (NET), NLRP3, pro-IL-1β, and interleukin (IL)-1β in pancreatic tissue was detected by Western blot and real-time PCR. Dexmedetomidine at 20 μg/kg significantly attenuated pancreatic pathological injury, reduced serum levels of amylase, lipase, IL-1β, IL-6, and tumor necrosis factor (TNF)-α, and decreased the expression of MPO in pancreatic tissue in both mouse models of pancreatitis. In addition, dexmedetomidine at 20 μg/kg significantly down-regulated the expression of NLRP3, pro-IL-1β, and IL-1β in pancreatic tissue, but up-regulated the expression of NET in both mouse models. Dexmedetomidine attenuates pancreatic injury and inflammatory response in mice with pancreatitis possibly by reducing NLRP3 activation and up-regulating NET expression. Copyright © 2018 Elsevier Inc. All rights reserved.

Marine Mammal Brucella Reference Strains Are Attenuated in a BALB/c Mouse Model.

PubMed

Nymo, Ingebjørg H; Arias, Maykel A; Pardo, Julián; Álvarez, María Pilar; Alcaraz, Ana; Godfroid, Jacques; Jiménez de Bagüés, María Pilar

2016-01-01

Brucellosis is a zoonosis of worldwide distribution with numerous animal host species. Since the novel isolation of Brucella spp. from marine mammals in 1994 the bacteria have been isolated from various marine mammal hosts. The marine mammal reference strains Brucella pinnipedialis 12890 (harbour seal, Phoca vitulina) and Brucella ceti 12891 (harbour porpoise, Phocoena phocoena) were included in genus Brucella in 2007, however, their pathogenicity in the mouse model is pending. Herein this is evaluated in BALB/c mice with Brucella suis 1330 as a control. Both marine mammal strains were attenuated, however, B. ceti was present at higher levels than B. pinnipedialis in blood, spleen and liver throughout the infection, in addition B. suis and B. ceti were isolated from brains and faeces at times with high levels of bacteraemia. In B. suis-infected mice serum cytokines peaked at day 7. In B. pinnipedialis-infected mice, levels were similar, but peaked predominantly at day 3 and an earlier peak in spleen weight likewise implied an earlier response. The inflammatory response induced pathology in the spleen and liver. In B. ceti-infected mice, most serum cytokine levels were comparable to those in uninfected mice, consistent with a limited inflammatory response, which also was indicated by restricted spleen and liver pathology. Specific immune responses against all three strains were detected in vitro after stimulation of splenocytes from infected mice with the homologous heat-killed brucellae. Antibody responses in vivo were also induced by the three brucellae. The immunological pattern of B. ceti in combination with persistence in organs and limited pathology has heretofore not been described for other brucellae. These two marine mammal wildtype strains show an attenuated pattern in BALB/c mice only previously described for Brucella neotomea.

Methylene blue upregulates Nrf2/ARE genes and prevents tau-related neurotoxicity

PubMed Central

Stack, Cliona; Jainuddin, Shari; Elipenahli, Ceyhan; Gerges, Meri; Starkova, Natalia; Starkov, Anatoly A.; Jové, Mariona; Portero-Otin, Manuel; Launay, Nathalie; Pujol, Aurora; Kaidery, Navneet Ammal; Thomas, Bobby; Tampellini, Davide; Beal, M. Flint; Dumont, Magali

2014-01-01

Methylene blue (MB, methylthioninium chloride) is a phenothiazine that crosses the blood brain barrier and acts as a redox cycler. Among its beneficial properties are its abilities to act as an antioxidant, to reduce tau protein aggregation and to improve energy metabolism. These actions are of particular interest for the treatment of neurodegenerative diseases with tau protein aggregates known as tauopathies. The present study examined the effects of MB in the P301S mouse model of tauopathy. Both 4 mg/kg MB (low dose) and 40 mg/kg MB (high dose) were administered in the diet ad libitum from 1 to 10 months of age. We assessed behavior, tau pathology, oxidative damage, inflammation and numbers of mitochondria. MB improved the behavioral abnormalities and reduced tau pathology, inflammation and oxidative damage in the P301S mice. These beneficial effects were associated with increased expression of genes regulated by NF-E2-related factor 2 (Nrf2)/antioxidant response element (ARE), which play an important role in antioxidant defenses, preventing protein aggregation, and reducing inflammation. The activation of Nrf2/ARE genes is neuroprotective in other transgenic mouse models of neurodegenerative diseases and it appears to be an important mediator of the neuroprotective effects of MB in P301S mice. Moreover, we used Nrf2 knock out fibroblasts to show that the upregulation of Nrf2/ARE genes by MB is Nrf2 dependent and not due to secondary effects of the compound. These findings provide further evidence that MB has important neuroprotective effects that may be beneficial in the treatment of human neurodegenerative diseases with tau pathology. PMID:24556215

Methylene blue upregulates Nrf2/ARE genes and prevents tau-related neurotoxicity.

PubMed

Stack, Cliona; Jainuddin, Shari; Elipenahli, Ceyhan; Gerges, Meri; Starkova, Natalia; Starkov, Anatoly A; Jové, Mariona; Portero-Otin, Manuel; Launay, Nathalie; Pujol, Aurora; Kaidery, Navneet Ammal; Thomas, Bobby; Tampellini, Davide; Beal, M Flint; Dumont, Magali

2014-07-15

Methylene blue (MB, methylthioninium chloride) is a phenothiazine that crosses the blood brain barrier and acts as a redox cycler. Among its beneficial properties are its abilities to act as an antioxidant, to reduce tau protein aggregation and to improve energy metabolism. These actions are of particular interest for the treatment of neurodegenerative diseases with tau protein aggregates known as tauopathies. The present study examined the effects of MB in the P301S mouse model of tauopathy. Both 4 mg/kg MB (low dose) and 40 mg/kg MB (high dose) were administered in the diet ad libitum from 1 to 10 months of age. We assessed behavior, tau pathology, oxidative damage, inflammation and numbers of mitochondria. MB improved the behavioral abnormalities and reduced tau pathology, inflammation and oxidative damage in the P301S mice. These beneficial effects were associated with increased expression of genes regulated by NF-E2-related factor 2 (Nrf2)/antioxidant response element (ARE), which play an important role in antioxidant defenses, preventing protein aggregation, and reducing inflammation. The activation of Nrf2/ARE genes is neuroprotective in other transgenic mouse models of neurodegenerative diseases and it appears to be an important mediator of the neuroprotective effects of MB in P301S mice. Moreover, we used Nrf2 knock out fibroblasts to show that the upregulation of Nrf2/ARE genes by MB is Nrf2 dependent and not due to secondary effects of the compound. These findings provide further evidence that MB has important neuroprotective effects that may be beneficial in the treatment of human neurodegenerative diseases with tau pathology. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Proteomics-level analysis of myelin formation and regeneration in a mouse model for Vanishing White Matter disease.

PubMed

Gat-Viks, Irit; Geiger, Tamar; Barbi, Mali; Raini, Gali; Elroy-Stein, Orna

2015-08-01

Vanishing white matter (VWM) is a recessive neurodegenerative disease caused by mutations in translation initiation factor eIF2B and leading to progressive brain myelin deterioration, secondary axonal damage, and death in early adolescence. Eif2b5(R132H/R132H) mice exhibit delayed developmental myelination, mild early neurodegeneration and a robust remyelination defect in response to cuprizone-induced demyelination. In the current study we used Eif2b5(R132H/R132H) mice for mass-spectrometry analyses, to follow the changes in brain protein abundance in normal- versus cuprizone-diet fed mice during the remyelination recovery phase. Analysis of proteome profiles suggested that dysregulation of mitochondrial functions, altered proteasomal activity and impaired balance between protein synthesis and degradation play a role in VWM pathology. Consistent with these findings, we detected elevated levels of reactive oxygen species in mutant-derived primary fibroblasts and reduced 20S proteasome activity in mutant brain homogenates. These observations highlight the importance of tight translational control to precise coordination of processes involved in myelin formation and regeneration and point at cellular functions that may contribute to VWM pathology. Eif2b5(R132H/R132H) mouse model for vanishing white matter (VWM) disease was used for mass spectrometry of brain proteins at two time points under normal conditions and along recovery from cuprizone-induced demyelination. Comparisons of proteome profiles revealed the importance of mitochondrial function and tight coordination between protein synthesis and degradation to myelination formation and regeneration, pointing at cellular functions that contribute to VWM pathology. © 2015 International Society for Neurochemistry.

LANP mediates neuritic pathology in Spinocerebellar ataxia type 1

PubMed Central

Cvetanovic, Marija; Kular, Rupinder K.; Opal, Puneet

2014-01-01

Spinocerebellar ataxia type 1 (SCA1) is an autosomal dominant neurodegenerative disease that results from a pathogenic glutamine-repeat expansion in the protein ataxin-1 (ATXN1). Although the functions of ATXN1 are still largely unknown, there is evidence to suggest that ATXN1 plays a role in regulating gene expression, the earliest process known to go awry in SCA1 mouse models. In this study, we show that ATXN1 reduces histone acetylation, a post-translational modification of histones associated with enhanced transcription, and represses histone acetyl transferase-mediated transcription. In addition, we find that depleting the Leucine-rich Acidic Nuclear Protein (LANP)—an ATXN1 binding inhibitor of histone acetylation—reverses aspects of SCA1 neuritic pathology. PMID:22884877

Elucidating the triggers, progression, and effects of Alzheimer's disease.

PubMed

Medeiros, Rodrigo; Chabrier, Meredith A; LaFerla, Frank M

2013-01-01

As the number of patients with Alzheimer's disease (AD) continues to rise, the need for efficacious therapeutics is becoming more and more urgent. Understanding the molecular relationship and interactions between Aβ and tau and their contribution to cognitive decline remain one of the most fundamental and unresolved questions in the AD field. Likewise, elucidating the initial triggers of disease pathology, as well as the impact of various factors such as stress and inflammation on disease progression, are equally important to fully understand this devastating disorder. Here we discuss recent studies that have illuminated the importance of key facilitators of disease progression using the 3xTg-AD and CaM/Tet-DTA mouse models, and suggest viable targets for ameliorating both molecular pathology and cognitive decline.

Comparison of In Vivo and Ex Vivo MRI for the Detection of Structural Abnormalities in a Mouse Model of Tauopathy

PubMed Central

Holmes, Holly E.; Powell, Nick M.; Ma, Da; Ismail, Ozama; Harrison, Ian F.; Wells, Jack A.; Colgan, Niall; O'Callaghan, James M.; Johnson, Ross A.; Murray, Tracey K.; Ahmed, Zeshan; Heggenes, Morten; Fisher, Alice; Cardoso, M. Jorge; Modat, Marc; O'Neill, Michael J.; Collins, Emily C.; Fisher, Elizabeth M. C.; Ourselin, Sébastien; Lythgoe, Mark F.

2017-01-01

With increasingly large numbers of mouse models of human disease dedicated to MRI studies, compromises between in vivo and ex vivo MRI must be fully understood in order to inform the choice of imaging methodology. We investigate the application of high resolution in vivo and ex vivo MRI, in combination with tensor-based morphometry (TBM), to uncover morphological differences in the rTg4510 mouse model of tauopathy. The rTg4510 mouse also offers a novel paradigm by which the overexpression of mutant tau can be regulated by the administration of doxycycline, providing us with a platform on which to investigate more subtle alterations in morphology with morphometry. Both in vivo and ex vivo MRI allowed the detection of widespread bilateral patterns of atrophy in the rTg4510 mouse brain relative to wild-type controls. Regions of volume loss aligned with neuronal loss and pathological tau accumulation demonstrated by immunohistochemistry. When we sought to investigate more subtle structural alterations in the rTg4510 mice relative to a subset of doxycycline-treated rTg4510 mice, ex vivo imaging enabled the detection of more regions of morphological brain changes. The disadvantages of ex vivo MRI may however mitigate this increase in sensitivity: we observed a 10% global shrinkage in brain volume of the post-mortem tissues due to formalin fixation, which was most notable in the cerebellum and olfactory bulbs. However, many central brain regions were not adversely affected by the fixation protocol, perhaps due to our “in-skull” preparation. The disparity between our TBM findings from in vivo and ex vivo MRI underlines the importance of appropriate study design, given the trade-off between these two imaging approaches. We support the utility of in vivo MRI for morphological phenotyping of mouse models of disease; however, for subtler phenotypes, ex vivo offers enhanced sensitivity to discrete morphological changes. PMID:28408879

Comparison of In Vivo and Ex Vivo MRI for the Detection of Structural Abnormalities in a Mouse Model of Tauopathy.

PubMed

Holmes, Holly E; Powell, Nick M; Ma, Da; Ismail, Ozama; Harrison, Ian F; Wells, Jack A; Colgan, Niall; O'Callaghan, James M; Johnson, Ross A; Murray, Tracey K; Ahmed, Zeshan; Heggenes, Morten; Fisher, Alice; Cardoso, M Jorge; Modat, Marc; O'Neill, Michael J; Collins, Emily C; Fisher, Elizabeth M C; Ourselin, Sébastien; Lythgoe, Mark F

2017-01-01

With increasingly large numbers of mouse models of human disease dedicated to MRI studies, compromises between in vivo and ex vivo MRI must be fully understood in order to inform the choice of imaging methodology. We investigate the application of high resolution in vivo and ex vivo MRI, in combination with tensor-based morphometry (TBM), to uncover morphological differences in the rTg4510 mouse model of tauopathy. The rTg4510 mouse also offers a novel paradigm by which the overexpression of mutant tau can be regulated by the administration of doxycycline, providing us with a platform on which to investigate more subtle alterations in morphology with morphometry. Both in vivo and ex vivo MRI allowed the detection of widespread bilateral patterns of atrophy in the rTg4510 mouse brain relative to wild-type controls. Regions of volume loss aligned with neuronal loss and pathological tau accumulation demonstrated by immunohistochemistry. When we sought to investigate more subtle structural alterations in the rTg4510 mice relative to a subset of doxycycline-treated rTg4510 mice, ex vivo imaging enabled the detection of more regions of morphological brain changes. The disadvantages of ex vivo MRI may however mitigate this increase in sensitivity: we observed a 10% global shrinkage in brain volume of the post-mortem tissues due to formalin fixation, which was most notable in the cerebellum and olfactory bulbs. However, many central brain regions were not adversely affected by the fixation protocol, perhaps due to our "in-skull" preparation. The disparity between our TBM findings from in vivo and ex vivo MRI underlines the importance of appropriate study design, given the trade-off between these two imaging approaches. We support the utility of in vivo MRI for morphological phenotyping of mouse models of disease; however, for subtler phenotypes, ex vivo offers enhanced sensitivity to discrete morphological changes.

Genetically Engineered ERα positive breast cancer mouse models

PubMed Central

Dabydeen, Sarah A.; Furth, Priscilla A.

2014-01-01

The majority of human breast cancers are ER+ but this has proven challenging to model in genetically engineered mice. This review summarizes information on twenty-one mouse models that develop ER+ mammary cancer. Where available, information on cancer pathology and gene expression profiles is referenced to assist in understanding which histological subtype of ER+ human cancer each model might represent. Esr1, Ccdn1, prolactin, TGFα, AIB1, Espl1, and Wnt1 over-expression, Pik3ca gain of function, as well as loss of p53 or loss of Stat1 are associated with ER+ mammary cancer. Treatment with the PPARγ agonist efatutazone in a mouse with Brca1 and p53 deficiency and DMBA exposure in combination with an activated myristoylated form of AKT1 also induce ER+ mammary cancer. A spontaneous mutant in nude mice that develops metastatic ER+ mammary cancer is included. Age of cancer development ranges from three to 26 months and the percentages of cancers that are ER+ vary from 21% to 100%. Not all models are characterized as to their estrogen dependency and/or response to anti-hormonal therapy. Strain backgrounds include C57Bl/6, FVB, BALB/c, 129S6/SvEv, CB6F1 and NIH nude. Most models have only been studied on one strain background. In summary while a range of models is available for studies of pathogenesis and therapy of ER+ breast cancers, many could benefit from further characterization and opportunity for development of new models remains. PMID:24481326

Protocols to Evaluate Cigarette Smoke-Induced Lung Inflammation and Pathology in Mice.

PubMed

Vlahos, Ross; Bozinovski, Steven

2018-01-01

Cigarette smoking is a major cause of chronic obstructive pulmonary disease (COPD). Inhalation of cigarette smoke causes inflammation of the airways, airway wall remodelling, mucus hypersecretion and progressive airflow limitation. Much of the disease burden and health care utilisation in COPD is associated with the management of its comorbidities and infectious (viral and bacterial) exacerbations (AECOPD). Comorbidities, in particular skeletal muscle wasting, cardiovascular disease and lung cancer markedly impact on disease morbidity, progression and mortality. The mechanisms and mediators underlying COPD and its comorbidities are poorly understood and current COPD therapy is relatively ineffective. Many researchers have used animal modelling systems to explore the mechanisms underlying COPD, AECOPD and comorbidities of COPD with the goal of identifying novel therapeutic targets. Here we describe a mouse model that we have developed to define the cellular, molecular and pathological consequences of cigarette smoke exposure and the development of comorbidities of COPD.

Depletion of microglia and inhibition of exosome synthesis halt tau propagation

PubMed Central

Asai, Hirohide; Ikezu, Seiko; Tsunoda, Satoshi; Medalla, Maria; Luebke, Jennifer; Haydar, Tarik; Wolozin, Benjamin; Butovsky, Oleg; Kügler, Sebastian; Ikezu, Tsuneya

2015-01-01

Accumulation of pathological tau protein is a major hallmark of Alzheimer’s disease. Tau protein spreads from the entorhinal cortex to the hippocampal region early in the disease. Microglia, the primary phagocytes in the brain, are positively correlated with tau pathology, but their involvement in tau propagation is unknown. We developed an adeno-associated virus–based model exhibiting rapid tau propagation from the entorhinal cortex to the dentate gyrus in 4 weeks. We found that depleting microglia dramatically suppressed the propagation of tau and reduced excitability in the dentate gyrus in this mouse model. Moreover, we demonstrate that microglia spread tau via exosome secretion, and inhibiting exosome synthesis significantly reduced tau propagation in vitro and in vivo. These data suggest that microglia and exosomes contribute to the progression of tauopathy and that the exosome secretion pathway may be a therapeutic target. PMID:26436904

Breaking immune tolerance by targeting Foxp3+ regulatory T cells mitigates Alzheimer's disease pathology

PubMed Central

Baruch, Kuti; Rosenzweig, Neta; Kertser, Alexander; Deczkowska, Aleksandra; Sharif, Alaa Mohammad; Spinrad, Amit; Tsitsou-Kampeli, Afroditi; Sarel, Ayelet; Cahalon, Liora; Schwartz, Michal

2015-01-01

Alzheimer's disease (AD) is a neurodegenerative disorder in which chronic neuroinflammation contributes to disease escalation. Nevertheless, while immunosuppressive drugs have repeatedly failed in treating this disease, recruitment of myeloid cells to the CNS was shown to play a reparative role in animal models. Here we show, using the 5XFAD AD mouse model, that transient depletion of Foxp3+ regulatory T cells (Tregs), or pharmacological inhibition of their activity, is followed by amyloid-β plaque clearance, mitigation of the neuroinflammatory response and reversal of cognitive decline. We further show that transient Treg depletion affects the brain's choroid plexus, a selective gateway for immune cell trafficking to the CNS, and is associated with subsequent recruitment of immunoregulatory cells, including monocyte-derived macrophages and Tregs, to cerebral sites of plaque pathology. Our findings suggest targeting Treg-mediated systemic immunosuppression for treating AD. PMID:26284939

Transcriptional profiling reveals progeroid Ercc1-/Δ mice as a model system for glomerular aging

PubMed Central

2013-01-01

Background Aging-related kidney diseases are a major health concern. Currently, models to study renal aging are lacking. Due to a reduced life-span progeroid models hold the promise to facilitate aging studies and allow examination of tissue-specific changes. Defects in genome maintenance in the Ercc1-/Δ progeroid mouse model result in premature aging and typical age-related pathologies. Here, we compared the glomerular transcriptome of young and aged Ercc1-deficient mice to young and aged WT mice in order to establish a novel model for research of aging-related kidney disease. Results In a principal component analysis, age and genotype emerged as first and second principal components. Hierarchical clustering of all 521 genes differentially regulated between young and old WT and young and old Ercc1-/Δ mice showed cluster formation between young WT and Ercc1-/Δ as well as old WT and Ercc1-/Δ samples. An unexpectedly high number of 77 genes were differentially regulated in both WT and Ercc1-/Δ mice (p < 0.0001). GO term enrichment analysis revealed these genes to be involved in immune and inflammatory response, cell death, and chemotaxis. In a network analysis, these genes were part of insulin signaling, chemokine and cytokine signaling and extracellular matrix pathways. Conclusion Beyond insulin signaling, we find chemokine and cytokine signaling as well as modifiers of extracellular matrix composition to be subject to major changes in the aging glomerulus. At the level of the transcriptome, the pattern of gene activities is similar in the progeroid Ercc1-/Δ mouse model constituting a valuable tool for future studies of aging-associated glomerular pathologies. PMID:23947592

Transcriptional profiling reveals progeroid Ercc1(-/Δ) mice as a model system for glomerular aging.

PubMed

Schermer, Bernhard; Bartels, Valerie; Frommolt, Peter; Habermann, Bianca; Braun, Fabian; Schultze, Joachim L; Roodbergen, Marianne; Hoeijmakers, Jan Hj; Schumacher, Björn; Nürnberg, Peter; Dollé, Martijn Et; Benzing, Thomas; Müller, Roman-Ulrich; Kurschat, Christine E

2013-08-16

Aging-related kidney diseases are a major health concern. Currently, models to study renal aging are lacking. Due to a reduced life-span progeroid models hold the promise to facilitate aging studies and allow examination of tissue-specific changes. Defects in genome maintenance in the Ercc1(-/Δ) progeroid mouse model result in premature aging and typical age-related pathologies. Here, we compared the glomerular transcriptome of young and aged Ercc1-deficient mice to young and aged WT mice in order to establish a novel model for research of aging-related kidney disease. In a principal component analysis, age and genotype emerged as first and second principal components. Hierarchical clustering of all 521 genes differentially regulated between young and old WT and young and old Ercc1(-/Δ) mice showed cluster formation between young WT and Ercc1(-/Δ) as well as old WT and Ercc1(-/Δ) samples. An unexpectedly high number of 77 genes were differentially regulated in both WT and Ercc1(-/Δ) mice (p < 0.0001). GO term enrichment analysis revealed these genes to be involved in immune and inflammatory response, cell death, and chemotaxis. In a network analysis, these genes were part of insulin signaling, chemokine and cytokine signaling and extracellular matrix pathways. Beyond insulin signaling, we find chemokine and cytokine signaling as well as modifiers of extracellular matrix composition to be subject to major changes in the aging glomerulus. At the level of the transcriptome, the pattern of gene activities is similar in the progeroid Ercc1(-/Δ) mouse model constituting a valuable tool for future studies of aging-associated glomerular pathologies.

Withaferin A Inhibits Prostate Carcinogenesis in a PTEN-deficient Mouse Model of Prostate Cancer.

PubMed

Moselhy, Jim; Suman, Suman; Alghamdi, Mohammed; Chandarasekharan, Balaji; Das, Trinath P; Houda, Alatassi; Ankem, Murali; Damodaran, Chendil

2017-06-01

We recently demonstrated that AKT activation plays a role in prostate cancer progression and inhibits the pro-apoptotic function of FOXO3a and Par-4. AKT inhibition and Par-4 induction suppressed prostate cancer progression in preclinical models. Here, we investigate the chemopreventive effect of the phytonutrient Withaferin A (WA) on AKT-driven prostate tumorigenesis in a Pten conditional knockout (Pten-KO) mouse model of prostate cancer. Oral WA treatment was carried out at two different doses (3 and 5 mg/kg) and compared to vehicle over 45 weeks. Oral administration of WA for 45 weeks effectively inhibited primary tumor growth in comparison to vehicle controls. Pathological analysis showed the complete absence of metastatic lesions in organs from WA-treated mice, whereas discrete metastasis to the lungs was observed in control tumors. Immunohistochemical analysis revealed the down-regulation of pAKT expression and epithelial-to-mesenchymal transition markers, such as β-catenin and N-cadherin, in WA-treated tumors in comparison to controls. This result corroborates our previous findings from both cell culture and xenograft models of prostate cancer. Our findings demonstrate that the daily administration of a phytonutrient that targets AKT activation provides a safe and effective treatment for prostate cancer in a mouse model with strong potential for translation to human disease. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Quantitative assessment of the blood-brain barrier opening caused by Streptococcus agalactiae hyaluronidase in a BALB/c mouse model.

PubMed

Luo, Su; Cao, Qing; Ma, Ke; Wang, Zhaofei; Liu, Guangjin; Lu, Chengping; Liu, Yongjie

2017-10-19

Streptococcus agalactiae is a pathogen causing meningitis in animals and humans. However, little is known about the entry of S. agalactiae into brain tissue. In this study, we developed a BALB/c mouse model based on the intravenous injection of β-galactosidase-positive Escherichia coli M5 as an indicator of blood-brain barrier (BBB) opening. Under physiological conditions, the BBB is impermeable to E. coli M5. In pathological conditions caused by S. agalactiae, E. coli M5 is capable of penetrating the brain through a disrupted BBB. The level of BBB opening can be assessed by quantitative measurement of E. coli M5 loads per gram of brain tissue. Further, we used the model to evaluate the role of S. agalactiae hyaluronidase in BBB opening. The inactivation of hylB gene encoding a hyaluronidase, HylB, resulted in significantly decreased E. coli M5 colonization, and the intravenous injection of purified HylB protein induced BBB opening in a dose-dependent manner. This finding verified the direct role of HylB in BBB invasion and traversal, and further demonstrated the practicability of the in vivo mouse model established in this study. This model will help to understand the S. agalactiae-host interactions that are involved in this bacterial traversal of the BBB and to develop efficacious strategies to prevent central nervous system infections.

Pain, motor and gait assessment of murine osteoarthritis in a cruciate ligament transection model

PubMed Central

Ruan, Merry ZC; Patel, Ronak M; Dawson, Brian C; Jiang, Ming-ming; Lee, Brendan HI

2013-01-01

Objective The major complaint of Osteoarthritis (OA) patients is pain. However, due to the nature of clinical studies and the limitation of animal studies, few studies have linked function impairment and behavioral changes in OA animal models to cartilage loss and histopathology. Our objective was to study surrogate markers of functional impairment in relation to cartilage loss and pathological changes in a post-traumatic mouse model of OA. Method We performed a battery of functional analyses in a mouse model of OA generated by cruciate ligament transection (CLT). The changes in functional analyses were linked to histological changes graded by OARSI standards, histological grading of synovitis, and volumetric changes of the articular cartilage and osteophytes quantified by phase contrast micro-CT. Results OA generated by CLT led to decreased time on rotarod, delayed response on hotplate analysis, and altered gait starting from 4 weeks after surgery. Activity in open field analysis did not change at 4, 8, or 12 weeks after CLT. The magnitude of behavioral changes was directly correlated with higher OARSI histological scores of OA, synovitis in the knee joints, cartilage volume loss, and osteophyte formation. Conclusion Our findings link functional analyses to histological grading, synovitis, comprehensive 3-dimensional assessment of cartilage volume and osteophyte formation. This serves as a reference for a mouse model in predicting outcomes of OA treatment. PMID:23973150

Quantitative volumetric imaging of normal, neoplastic and hyperplastic mouse prostate using ultrasound.

PubMed

Singh, Shalini; Pan, Chunliu; Wood, Ronald; Yeh, Chiuan-Ren; Yeh, Shuyuan; Sha, Kai; Krolewski, John J; Nastiuk, Kent L

2015-09-21

Genetically engineered mouse models are essential to the investigation of the molecular mechanisms underlying human prostate pathology and the effects of therapy on the diseased prostate. Serial in vivo volumetric imaging expands the scope and accuracy of experimental investigations of models of normal prostate physiology, benign prostatic hyperplasia and prostate cancer, which are otherwise limited by the anatomy of the mouse prostate. Moreover, accurate imaging of hyperplastic and tumorigenic prostates is now recognized as essential to rigorous pre-clinical trials of new therapies. Bioluminescent imaging has been widely used to determine prostate tumor size, but is semi-quantitative at best. Magnetic resonance imaging can determine prostate volume very accurately, but is expensive and has low throughput. We therefore sought to develop and implement a high throughput, low cost, and accurate serial imaging protocol for the mouse prostate. We developed a high frequency ultrasound imaging technique employing 3D reconstruction that allows rapid and precise assessment of mouse prostate volume. Wild-type mouse prostates were examined (n = 4) for reproducible baseline imaging, and treatment effects on volume were compared, and blinded data analyzed for intra- and inter-operator assessments of reproducibility by correlation and for Bland-Altman analysis. Examples of benign prostatic hyperplasia mouse model prostate (n = 2) and mouse prostate implantation of orthotopic human prostate cancer tumor and its growth (n =  ) are also demonstrated. Serial measurement volume of the mouse prostate revealed that high frequency ultrasound was very precise. Following endocrine manipulation, regression and regrowth of the prostate could be monitored with very low intra- and interobserver variability. This technique was also valuable to monitor the development of prostate growth in a model of benign prostatic hyperplasia. Additionally, we demonstrate accurate ultrasound image-guided implantation of orthotopic tumor xenografts and monitoring of subsequent tumor growth from ~10 to ~750 mm(3) volume. High frequency ultrasound imaging allows precise determination of normal, neoplastic and hyperplastic mouse prostate. Low cost and small image size allows incorporation of this imaging modality inside clean animal facilities, and thereby imaging of immunocompromised models. 3D reconstruction for volume determination is easily mastered, and both small and large relative changes in volume are accurately visualized. Ultrasound imaging does not rely on penetration of exogenous imaging agents, and so may therefore better measure poorly vascularized or necrotic diseased tissue, relative to bioluminescent imaging (IVIS). Our method is precise and reproducible with very low inter- and intra-observer variability. Because it is non-invasive, mouse models of prostatic disease states can be imaged serially, reducing inter-animal variability, and enhancing the power to detect small volume changes following therapeutic intervention.

DYRK1A promotes dopaminergic neuron survival in the developing brain and in a mouse model of Parkinson's disease.

PubMed

Barallobre, M J; Perier, C; Bové, J; Laguna, A; Delabar, J M; Vila, M; Arbonés, M L

2014-06-12

In the brain, programmed cell death (PCD) serves to adjust the numbers of the different types of neurons during development, and its pathological reactivation in the adult leads to neurodegeneration. Dual-specificity tyrosine-(Y)-phosphorylation regulated kinase 1A (DYRK1A) is a pleiotropic kinase involved in neural proliferation and cell death, and its role during brain growth is evolutionarily conserved. Human DYRK1A lies in the Down syndrome critical region on chromosome 21, and heterozygous mutations in the gene cause microcephaly and neurological dysfunction. The mouse model for DYRK1A haploinsufficiency (the Dyrk1a(+/-) mouse) presents neuronal deficits in specific regions of the adult brain, including the substantia nigra (SN), although the mechanisms underlying these pathogenic effects remain unclear. Here we study the effect of DYRK1A copy number variation on dopaminergic cell homeostasis. We show that mesencephalic DA (mDA) neurons are generated in the embryo at normal rates in the Dyrk1a haploinsufficient model and in a model (the mBACtgDyrk1a mouse) that carries three copies of Dyrk1a. We also show that the number of mDA cells diminishes in postnatal Dyrk1a(+/-) mice and increases in mBACtgDyrk1a mice due to an abnormal activity of the mitochondrial caspase9 (Casp9)-dependent apoptotic pathway during the main wave of PCD that affects these neurons. In addition, we show that the cell death induced by 1-methyl-4-phenyl-1,2,3,6 tetrahydropyridine (MPTP), a toxin that activates Casp9-dependent apoptosis in mDA neurons, is attenuated in adult mBACtgDyrk1a mice, leading to an increased survival of SN DA neurons 21 days after MPTP intoxication. Finally, we present data indicating that Dyrk1a phosphorylation of Casp9 at the Thr125 residue is the mechanism by which this kinase hinders both physiological and pathological PCD in mDA neurons. These data provide new insight into the mechanisms that control cell death in brain DA neurons and they show that deregulation of developmental apoptosis may contribute to the phenotype of patients with imbalanced DYRK1A gene dosage.

17-β Estradiol reduces atherosclerosis without exacerbating lupus in ovariectomized systemic lupus erythematosus-susceptible LDLr(-/-) mice.

PubMed

Shelton, K A; Cline, J M; Cann, J A

2013-04-01

To test the hypothesis that estrogen treatment in a radiation chimera mouse model of systemic lupus erythematosus (SLE) and atherosclerosis will increase SLE-associated atherosclerosis by increasing autoantibody production and inflammation. We used a radiation chimera mouse model in which bone marrow from the polygenic B6.Sle1.2.3 model of SLE was transferred to the low density lipoprotein receptor knock out (LDLr(-/-)) model of atherosclerosis on a C57BL/6 background (Sle/LDLr(-/-)). Ovariectomized chimeric mice were treated for 10 weeks with either 5.6 μg/day of 17β-estradiol or placebo; outcomes included atherosclerosis plaque size, anti-dsDNA autoantibody production and renal pathology. Mean atherosclerosis plaque size was 67.4 ± 7.6% smaller in the estrogen treated group (p < 0.0001). Estrogen treated Sle/LDLr(-/-) mice had no significant difference in serum cholesterol concentration, lipoprotein distribution, anti-dsDNA autoantibody concentration, antibody isotype concentration and renal histopathology score compared to placebo. However, they had significantly lower mean urine protein to urine creatinine ratio (UP:UC). There was no correlation between atherosclerosis lesion size and either the renal histology score or UP:UC ratio in Sle/LDLr(-/-) mice. These results indicate that 17β-estradiol is atheroprotective within the context of murine SLE independent of changes in serum cholesterol concentration, autoantibody concentration, or renal pathology. The SLE phenotype in Sle/LDLr(-/-) mice is not exacerbated by exogenous 17β-estradiol administration, and the reduced UP:UC ratio suggests a protective effect against lupus nephritis. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Angiotensin II, hypertension and angiotensin II receptor antagonism: Roles in the behavioural and brain pathology of a mouse model of Alzheimer's disease.

PubMed

Wiesmann, Maximilian; Roelofs, Monica; van der Lugt, Robert; Heerschap, Arend; Kiliaan, Amanda J; Claassen, Jurgen Ahr

2017-07-01

Elevated angiotensin II causes hypertension and contributes to Alzheimer's disease by affecting cerebral blood flow. Angiotensin II receptor blockers may provide candidates to reduce (vascular) risk factors for Alzheimer's disease. We studied effects of two months of angiotensin II-induced hypertension on systolic blood pressure, and treatment with the angiotensin II receptor blockers, eprosartan mesylate, after one month of induced hypertension in wild-type C57bl/6j and AβPPswe/PS1ΔE9 (AβPP/PS1/Alzheimer's disease) mice. AβPP/PS1 showed higher systolic blood pressure than wild-type. Subsequent eprosartan mesylate treatment restored this elevated systolic blood pressure in all mice. Functional connectivity was decreased in angiotensin II-infused Alzheimer's disease and wild-type mice, and only 12 months of Alzheimer's disease mice showed impaired cerebral blood flow. Only angiotensin II-infused Alzheimer's disease mice exhibited decreased spatial learning in the Morris water maze. Altogether, angiotensin II-induced hypertension not only exacerbated Alzheimer's disease-like pathological changes such as impairment of cerebral blood flow, functional connectivity, and cognition only in Alzheimer's disease model mice, but it also induced decreased functional connectivity in wild-type mice. However, we could not detect hypertension-induced overexpression of Aβ nor increased neuroinflammation. Our findings suggest a link between midlife hypertension, decreased cerebral hemodynamics and connectivity in an Alzheimer's disease mouse model. Eprosartan mesylate treatment restored and beneficially affected cerebral blood flow and connectivity. This model could be used to investigate prevention/treatment strategies in early Alzheimer's disease.

17-β Estradiol reduces atherosclerosis without exacerbating lupus in ovariectomized systemic lupus erythematosus-susceptible LDLr−/− mice

PubMed Central

Shelton, KA; Cline, JM; Cann, JA

2013-01-01

Objective To test the hypothesis that estrogen treatment in a radiation chimera mouse model of systemic lupus erythematosus (SLE) and atherosclerosis will increase SLE-associated atherosclerosis by increasing autoantibody production and inflammation. Methods We used a radiation chimera mouse model in which bone marrow from the polygenic B6.Sle1.2.3 model of SLE was transferred to the low density lipoprotein receptor knock out (LDLr−/−) model of atherosclerosis on a C57BL/6 background (Sle/LDLr−/−). Ovariectomized chimeric mice were treated for 10 weeks with either 5.6 ug/day of 17β-estradiol or placebo; outcomes included atherosclerosis plaque size, anti-dsDNA autoantibody production and renal pathology. Results Mean atherosclerosis plaque size was 67.4 ± 7.6% smaller in the estrogen treated group (p<0.0001). Estrogen treated Sle/LDLr−/− mice had no significant difference in serum cholesterol concentration, lipoprotein distribution, anti-dsDNA autoantibody concentration, antibody isotype concentration and renal histopathology score compared to placebo. However, they had significantly lower mean urine protein to urine creatinine ratio (UP:UC). There was no correlation between atherosclerosis lesion size and either the renal histology score or UP:UC ratio in Sle/LDLr−/− mice. Conclusion These results indicate that 17β-estradiol is atheroprotective within the context of murine SLE independent of changes in serum cholesterol concentration, autoantibody concentration, or renal pathology. The SLE phenotype in Sle/LDLr−/− mice is not exacerbated by exogenous 17β-estradiol administration, and the reduced UP:UC ratio suggests a protective effect against lupus nephritis. PMID:23395521

STRESS RISK FACTORS AND STRESS-RELATED PATHOLOGY: NEUROPLASTICITY, EPIGENETICS AND ENDOPHENOTYPES

PubMed Central

Radley, Jason J.; Kabbaj, Mohamed; Jacobson, Lauren; Heydendael, Willem; Yehuda, Rachel; Herman, James P.

2013-01-01

This review highlights a symposium on stress risk factors and stress susceptibility, presented at the Neurobiology of Stress workshop in Boulder, Colorado, June 2010. This symposium addressed factors linking stress plasticity and reactivity to stress pathology in animal models and in humans. Dr. Jason Radley discussed studies demonstrating prefrontal cortical neuroplasticity and prefrontal control of hypothalamo-pituitary-adrenocortical axis function in rat, highlighting emerging evidence for a critical role of this region in normal and pathological stress integration. Dr. Mohamed Kabbaj summarized his studies of possible epigenetic mechanisms underlying behavioral differences in rat populations bred for differential stress reactivity. Dr. Lauren Jacobson described studies using a mouse model to explore the diverse actions of antidepressant action in brain, suggesting mechanisms whereby antidepressants may be differentially effective in treating specific depression endophenotypes. Dr. Rachel Yehuda discussed the role of glucocorticoids in post-traumatic stress disorder (PTSD), indicating that low cortisol may be a trait that predisposes the individual to development of the disorder. Furthermore, she presented evidence indicating that traumatic events can have transgenerational impact on cortisol reactivity and development of PTSD symptoms. Together, the symposium highlighted emerging themes regarding the role of brain reorganization, individual differences and epigenetics in determining stress plasticity and pathology. PMID:21848436

Modulation of Pathogenic B Cells through Inhibition of Phosphatidylinositol 3-Kinases

DTIC Science & Technology

2016-03-01

of the antibodies bound to the proteins can lodge in the kidneys resulting in damage to the filtering capacity of the kidney . The disease is most...such as nuclear proteins and DNA. These antibodies can cause additional pathologic changes because immune complexes lodge in the kidney which...secreting B cells in a mouse model for lupus, which results in less kidney damage and increased lifespan. 2. KEYWORDS: Lupus, PI3K, B cell, signal

Functional categorization of gene expression changes in the cerebellum of a Cln3-knockout mouse model for Batten disease.

PubMed

Brooks, Andrew I; Chattopadhyay, Subrata; Mitchison, Hannah M; Nussbaum, Robert L; Pearce, David A

2003-01-01

Juvenile neuronal ceroid lipofuscinosis (JNCL or Batten Disease) is the most common progressive neurodegenerative disorder of childhood. The disease is inherited in an autosomal recessive manner and is the result of mutations in the CLN3 gene. One brain region severely affected in Batten disease is the cerebellum. Using a mouse model for Batten disease which shares pathological similarities to the disease in humans we have used oligonucleotide arrays to profile approximately 19000 mRNAs in the cerebellum. We have identified reproducible changes of twofold or more in the expression of 756 gene products in the cerebellum of 10-week-old Cln3-knockout mice as compared to wild-type controls. We have subsequently divided these genes with altered expression into 14 functional categories. We report a significant alteration in expression of genes associated with neurotransmission, neuronal cell structure and development, immune response and inflammation, and lipid metabolism. An apparent shift in metabolism toward gluconeogenesis is also evident in Cln3-knockout mice. Further experimentation will be necessary to understand the contribution of these changes in expression to a disease state. Detailed analysis of the functional consequences of altered expression of genes in the cerebellum of the Cln3-knockout mice may provide valuable clues in understanding the molecular basis of the pathological mechanisms underlying Batten disease.

AβPP/PS1 Transgenic Mice Show Sex Differences in the Cerebellum Associated with Aging.

PubMed

Ordoñez-Gutierrez, Lara; Fernandez-Perez, Ivan; Herrera, Jose Luis; Anton, Marta; Benito-Cuesta, Irene; Wandosell, Francisco

2016-09-06

Cerebellar pathology has been related to presenilin 1 mutations in certain pedigrees of familial Alzheimer's disease. However, cerebellum tissue has not been intensively analyzed in transgenic models of mutant presenilins. Furthermore, the effect of the sex of the mice was not systematically analyzed, despite the fact that important gender differences in the evolution of the disease in the human population have been described. We analyzed whether the progression of amyloidosis in a double transgenic mouse, AβPP/PS1, is susceptible to aging and differentially affects males and females. The accumulation of amyloid in the cerebellum differentially affects males and females of the AβPP/PS1 transgenic line, which was found to be ten-fold higher in 15-month-old females. Amyloid-β accumulation was more evident in the molecular layer of the cerebellum, but glia reaction was only observed in the granular layer of the older mice. The sex divergence was also observed in other neuronal, survival, and autophagic markers. The cerebellum plays an important role in the evolution of the pathology in this transgenic mouse model. Sex differences could be crucial for a complete understanding of this disease. We propose that the human population could be studied in this way. Sex-specific treatment strategies in human populations could show a differential response to the therapeutic approach.

Entry of Botulinum Neurotoxin Subtypes A1 and A2 into Neurons

PubMed Central

Kroken, Abby R.; Blum, Faith C.; Zuverink, Madison

2016-01-01

ABSTRACT Botulinum neurotoxins (BoNTs) are the most toxic proteins for humans but also are common therapies for neurological diseases. BoNTs are dichain toxins, comprising an N-terminal catalytic domain (LC) disulfide bond linked to a C-terminal heavy chain (HC) which includes a translocation domain (HN) and a receptor binding domain (HC). Recently, the BoNT serotype A (BoNT/A) subtypes A1 and A2 were reported to possess similar potencies but different rates of cellular intoxication and pathology in a mouse model of botulism. The current study measured HCA1 and HCA2 entry into rat primary neurons and cultured Neuro2A cells. We found that there were two sequential steps during the association of BoNT/A with neurons. The initial step was ganglioside dependent, while the subsequent step involved association with synaptic vesicles. HCA1 and HCA2 entered the same population of synaptic vesicles and entered cells at similar rates. The primary difference was that HCA2 had a higher degree of receptor occupancy for cells and neurons than HcA1. Thus, HCA2 and HCA1 share receptors and entry pathway but differ in their affinity for receptor. The initial interaction of HCA1 and HCA2 with neurons may contribute to the unique pathologies of BoNT/A1 and BoNT/A2 in mouse models. PMID:27795365

Underlying chronic inflammation alters the profile and mechanisms of acute neutrophil recruitment.

PubMed

Ma, Bin; Whiteford, James R; Nourshargh, Sussan; Woodfin, Abigail

2016-11-01

Chronically inflamed tissues show altered characteristics that include persistent populations of inflammatory leukocytes and remodelling of the vascular network. As the majority of studies on leukocyte recruitment have been carried out in normal healthy tissues, the impact of underlying chronic inflammation on ongoing leukocyte recruitment is largely unknown. Here, we investigate the profile and mechanisms of acute inflammatory responses in chronically inflamed and angiogenic tissues, and consider the implications for chronic inflammatory disorders. We have developed a novel model of chronic ischaemia of the mouse cremaster muscle that is characterized by a persistent population of monocyte-derived cells (MDCs), and capillary angiogenesis. These tissues also show elevated acute neutrophil recruitment in response to locally administered inflammatory stimuli. We determined that Gr1 low MDCs, which are widely considered to have anti-inflammatory and reparative functions, amplified acute inflammatory reactions via the generation of additional proinflammatory signals, changing both the profile and magnitude of the tissue response. Similar vascular and inflammatory responses, including activation of MDCs by transient ischaemia-reperfusion, were observed in mouse hindlimbs subjected to chronic ischaemia. This response demonstrates the relevance of the findings to peripheral arterial disease, in which patients experience transient exercise-induced ischaemia known as claudication.These findings demonstrate that chronically inflamed tissues show an altered profile and altered mechanisms of acute inflammatory responses, and identify tissue-resident MDCs as potential therapeutic targets. © 2016 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of Pathological Society of Great Britain and Ireland. © 2016 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of Pathological Society of Great Britain and Ireland.

Methods of in-vivo mouse lung micro-CT

NASA Astrophysics Data System (ADS)

Recheis, Wolfgang A.; Nixon, Earl; Thiesse, Jacqueline; McLennan, Geoffrey; Ross, Alan; Hoffman, Eric

2005-04-01

Micro-CT will have a profound influence on the accumulation of anatomical and physiological phenotypic changes in natural and transgenetic mouse models. Longitudinal studies will be greatly facilitated, allowing for a more complete and accurate description of events if in-vivo studies are accomplished. The purpose of the ongoing project is to establish a feasible and reproducible setup for in-vivo mouse lung micro-computed tomography (μCT). We seek to use in-vivo respiratory-gated μCT to follow mouse models of lung disease with subsequent recovery of the mouse. Methodologies for optimizing scanning parameters and gating for the in-vivo mouse lung are presented. A Scireq flexiVent ventilated the gas-anesthetized mice at 60 breaths/minute, 30 cm H20 PEEP, 30 ml/kg tidal volume and provided a respiratory signal to gate a Skyscan 1076 μCT. Physiologic monitoring allowed the control of vital functions and quality of anesthesia, e.g. via ECG monitoring. In contrary to longer exposure times with ex-vivo scans, scan times for in-vivo were reduced using 35μm pixel size, 158ms exposure time and 18μm pixel size, 316ms exposure time to reduce motion artifacts. Gating via spontaneous breathing was also tested. Optimal contrast resolution was achieved at 50kVp, 200μA, applying an aluminum filter (0.5mm). There were minimal non-cardiac related motion artifacts. Both 35μm and 1μm voxel size images were suitable for evaluation of the airway lumen and parenchymal density. Total scan times were 30 and 65 minutes respectively. The mice recovered following scanning protocols. In-vivo lung scanning with recovery of the mouse delivered reasonable image quality for longitudinal studies, e.g. mouse asthma models. After examining 10 mice, we conclude μCT is a feasible tool evaluating mouse models of lung pathology in longitudinal studies with increasing anatomic detail available for evaluation as one moves from in-vivo to ex-vivo studies. Further developments include automated bronchial tree segmentation and airway wall thickness measurement tools. Improvements in Hounsfield unit calibration have to be performed when the interest of the study lies in determining and quantifying parenchymal changes and rely on estimating partial volume contributions of underlying structures to voxel densities.

Shifts in gut microbiota composition in an APP/PSS1 transgenic mouse model of Alzheimer's disease during lifespan.

PubMed

Bäuerl, C; Collado, M C; Diaz Cuevas, A; Viña, J; Pérez Martínez, G

2018-06-01

Alzheimer's disease (AD) is the most common form of dementia and one of the major causes of disability and dependency in older people. Accumulating evidences link gut microbiota with different diseases and its relationship with neurodegenerative diseases is becoming most intriguing. This study was aimed to compare the gut microbiota of transgenic APP/PS1 (TG) mice, a well-established deterministic mouse model of AD, with their C57BL/6 wild-type (WT) littermates. Faecal samples were collected from 3-, 6- and 24-month-old mice and analysed by pyrosequencing of the V1-V3 region of the bacterial 16S rRNA genes. Bacterial profiles were similar in all young mice (3 months old), and started to diverge so that 6-month-old WT and TG mice had different and more diverse microbiota. During ageing, Turicibacteriaceae (typical mice bacterial group) and Rikenellaceae increased in all groups, although total Bacteroidetes remained stable. TG mice were characterized by an increase in Proteobacteria after 6 months, particularly the genus Sutterella (Betaproteobacteria), interestingly also increased in autism disorder. Also, the inflammation related family Erysipelotrichaceae was more abundant in TG mice at 24 months compared to wild-type control. In summary, AD pathology in mice shifts the gut microbiota towards profiles that share features with autism and inflammatory disorders. Alzheimer's disease is a neurodegenerative disease and neuroinflammation in the central nervous system appears to have a pivotal role. Using the transgenic APP/PS1 (TG) mouse model, we successfully characterized how AD pathology shifted gut microbiota composition during ageing towards an inflammation related bacterial profile related to Proteobacteria and Erysipelotrichaceae and suggest that these changes could contribute to disease progression and severity. Microbiota-targeted interventions could therefore represent a strategy to postpone disease symptoms. © 2018 The Society for Applied Microbiology.

Sildenafil reduces respiratory muscle weakness and fibrosis in the mdx mouse model of Duchenne muscular dystrophy.

PubMed

Percival, Justin M; Whitehead, Nicholas P; Adams, Marvin E; Adamo, Candace M; Beavo, Joseph A; Froehner, Stanley C

2012-09-01

Duchenne muscular dystrophy (DMD) is the most common form of muscular dystrophy caused by mutations in the dystrophin gene. Loss of dystrophin initiates a progressive decline in skeletal muscle integrity and contractile capacity which weakens respiratory muscles including the diaphragm, culminating in respiratory failure, the leading cause of morbidity and mortality in DMD patients. At present, corticosteroid treatment is the primary pharmacological intervention in DMD, but has limited efficacy and adverse side effects. Thus, there is an urgent need for new safe, cost-effective, and rapidly implementable treatments that slow disease progression. One promising new approach is the amplification of nitric oxide-cyclic guanosine monophosphate (NO-cGMP) signalling pathways with phosphodiesterase 5 (PDE5) inhibitors. PDE5 inhibitors serve to amplify NO signalling that is attenuated in many neuromuscular diseases including DMD. We report here that a 14-week treatment of the mdx mouse model of DMD with the PDE5 inhibitor sildenafil (Viagra(®), Revatio(®)) significantly reduced mdx diaphragm muscle weakness without impacting fatigue resistance. In addition to enhancing respiratory muscle contractility, sildenafil also promoted normal extracellular matrix organization. PDE5 inhibition slowed the establishment of mdx diaphragm fibrosis and reduced matrix metalloproteinase-13 (MMP-13) expression. Sildenafil also normalized the expression of the pro-fibrotic (and pro-inflammatory) cytokine tumour necrosis factor α (TNFα). Sildenafil-treated mdx diaphragms accumulated significantly less Evans Blue tracer dye than untreated controls, which is also indicative of improved diaphragm muscle health. We conclude that sildenafil-mediated PDE5 inhibition significantly reduces diaphragm respiratory muscle dysfunction and pathology in the mdx mouse model of Duchenne muscular dystrophy. This study provides new insights into the therapeutic utility of targeting defects in NO-cGMP signalling with PDE5 inhibitors in dystrophin-deficient muscle. Copyright © 2012 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Murine neonatal infection provides an efficient model for congenital ocular toxoplasmosis.

PubMed

Lahmar, Ibtissem; Guinard, Marie; Sauer, Arnaud; Marcellin, Luc; Abdelrahman, Tamer; Roux, Michel; Mousli, Marc; Moussa, Adnan; Babba, Hamouda; Pfaff, Alexander W; Candolfi, Ermanno

2010-02-01

Congenital infection is one of the most serious settings of infection with the apicomplexan parasite Toxoplasma gondii. Ocular diseases, such as retinochoroiditis, are the most common sequels of such infection in utero. However, while numerous studies have investigated the physiopathology of acquired toxoplasmosis, congenital infection has been largely neglected so far. Here, we establish a mouse model of congenital ocular toxoplasmosis. Parasite load and ocular pathology have been followed for the first 4 weeks of life. Ocular infection developed slowly compared to cerebral infection. Even after 4 weeks, not all eyes were infected and ocular parasite load was low. Therefore, we evaluated a scheme of neonatal infection to overcome problems associated with congenital infection. Development of infection and physiopathology was similar, but at a higher, more reliable rate. In summary, we have established a valuable model of neonatal ocular toxoplasmosis, which facilitates the research of the underlying physiopathological mechanisms and new diagnostic approaches of this pathology. Copyright 2009 Elsevier Inc. All rights reserved.

Phenotypic screening of hepatocyte nuclear factor (HNF) 4-{gamma} receptor knockout mice

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

Gerdin, Anna Karin; Surve, Vikas V.; Joensson, Marie

2006-10-20

Using the mouse as a model organism in pharmaceutical research presents unique advantages as its physiology in many ways resembles the human physiology, it also has a relatively short generation time, low breeding and maintenance costs, and is available in a wide variety of inbred strains. The ability to genetically modify mouse embryonic stem cells to generate mouse models that better mimic human disease is another advantage. In the present study, a comprehensive phenotypic screening protocol is applied to elucidate the phenotype of a novel mouse knockout model of hepatocyte nuclear factor (HNF) 4-{gamma}. HNF4-{gamma} is expressed in the kidneys,more » gut, pancreas, and testis. First level of the screen is aimed at general health, morphologic appearance, normal cage behaviour, and gross neurological functions. The second level of the screen looks at metabolic characteristics and lung function. The third level of the screen investigates behaviour more in-depth and the fourth level consists of a thorough pathological characterisation, blood chemistry, haematology, and bone marrow analysis. When compared with littermate wild-type mice (HNF4-{gamma}{sup +/+}), the HNF4-{gamma} knockout (HNF4-{gamma}{sup -/-}) mice had lowered energy expenditure and locomotor activity during night time that resulted in a higher body weight despite having reduced intake of food and water. HNF4-{gamma}{sup -/-} mice were less inclined to build nest and were found to spend more time in a passive state during the forced swim test.« less

Whole gene expression profile in blood reveals multiple pathways deregulation in R6/2 mouse model

PubMed Central

2013-01-01

Background Huntington Disease (HD) is a progressive neurological disorder, with pathological manifestations in brain areas and in periphery caused by the ubiquitous expression of mutant Huntingtin protein. Transcriptional dysregulation is considered a key molecular mechanism responsible of HD pathogenesis but, although numerous studies investigated mRNA alterations in HD, so far none evaluated a whole gene expression profile in blood of R6/2 mouse model. Findings To discover novel pathogenic mechanisms and potential peripheral biomarkers useful to monitor disease progression or drug efficacy, a microarray study was performed in blood of R6/2 at manifest stage and wild type littermate mice. This approach allowed to propose new peripheral molecular processes involved in HD and to suggest different panels of candidate biomarkers. Among the discovered deregulated processes, we focused on specific ones: complement and coagulation cascades, PPAR signaling, cardiac muscle contraction, and dilated cardiomyopathy pathways. Selected genes derived from these pathways were additionally investigated in other accessible tissues to validate these matrices as source of biomarkers, and in brain, to link central and peripheral disease manifestations. Conclusions Our findings validated the skeletal muscle as suitable source to investigate peripheral transcriptional alterations in HD and supported the hypothesis that immunological alteration may contribute to neurological degeneration. Moreover, the identification of altered signaling in mouse blood enforce R6/2 transgenic mouse as a powerful HD model while suggesting novel disease biomarkers for pre-clinical investigation. PMID:24252798

Altered intestinal bile salt biotransformation in a cystic fibrosis (Cftr-/-) mouse model with hepato-biliary pathology.

PubMed

Bodewes, Frank A J A; van der Wulp, Mariëtte Y M; Beharry, Satti; Doktorova, Marcela; Havinga, Rick; Boverhof, Renze; James Phillips, M; Durie, Peter R; Verkade, Henkjan J

2015-07-01

Cftr(-/-tm1Unc) mice develop progressive hepato-biliary pathology. We hypothesize that this liver pathology is related to alterations in biliary bile hydrophobicity and bile salt metabolism in Cftr(-/-tm1Unc) mice. We determined bile production, biliary and fecal bile salt- and lipid compositions and fecal bacterial composition of C57BL/6J Cftr(-/-tm1Unc) and control mice. We found no differences between the total biliary bile salt or lipid concentrations of Cftr(-/-) and controls. Compared to controls, Cftr(-/-) mice had a ~30% higher bile production and a low bile hydrophobicity, related to a ~7 fold higher concentration of the choleretic and hydrophilic bile salt ursocholate. These findings coexisted with a significantly smaller quantity of fecal Bacteroides bacteria. Liver pathology in Cftr(-/-tm1Unc) is not related to increased bile hydrophobicity. Cftr(-/-) mice do however display a biliary phenotype characterized by increased bile production and decreased biliary hydrophobicity. Our findings suggest Cftr dependent, alterations in intestinal bacterial biotransformation of bile salts. Copyright © 2014. Published by Elsevier B.V.

Maintenance of airway epithelium in acutely rejected orthotopic vascularized mouse lung transplants.

PubMed

Okazaki, Mikio; Gelman, Andrew E; Tietjens, Jeremy R; Ibricevic, Aida; Kornfeld, Christopher G; Huang, Howard J; Richardson, Steven B; Lai, Jiaming; Garbow, Joel R; Patterson, G Alexander; Krupnick, Alexander S; Brody, Steven L; Kreisel, Daniel

2007-12-01

Lung transplantation remains the only therapeutic option for many patients suffering from end-stage pulmonary disease. Long-term success after lung transplantation is severely limited by the development of bronchiolitis obliterans. The murine heterotopic tracheal transplantation model has been widely used for studies investigating pathogenesis of obliterative airway disease and immunosuppressive strategies to prevent its development. Despite its utility, this model employs proximal airway that lacks airflow and is not vascularized. We have developed a novel model of orthotopic vascularized lung transplantation in the mouse, which leads to severe vascular rejection in allogeneic strain combinations. Here we characterize differences in the fate of airway epithelial cells in nonimmunosuppressed heterotopic tracheal and vascularized lung allograft models over 28 days. Up-regulation of growth factors that are thought to be critical for the development of airway fibrosis and interstitial collagen deposition were similar in both models. However, while loss of airway epithelial cells occurred in the tracheal model, airway epithelium remained intact and fully differentiated in lung allografts, despite profound vascular rejection. Moreover, we demonstrate expression of the anti-apoptotic protein Bcl-2 in airway epithelial cells of acutely rejected lung allografts. These findings suggest that in addition to alloimmune responses, other stimuli may be required for the destruction of airway epithelial cells. Thus, the model of vascularized mouse lung transplantation may provide a new and more physiologic experimental tool to study the interaction between immune and nonimmune mechanisms affecting airway pathology in lung allografts.

Muscle biopsies from human muscle diseases with myopathic pathology reveal common alterations in mitochondrial function.

PubMed

Sunitha, Balaraju; Gayathri, Narayanappa; Kumar, Manish; Keshava Prasad, Thottethodi Subrahmanya; Nalini, Atchayaram; Padmanabhan, Balasundaram; Srinivas Bharath, Muchukunte Mukunda

2016-07-01

Muscle diseases are clinically and genetically heterogeneous and manifest as dystrophic, inflammatory and myopathic pathologies, among others. Our previous study on the cardiotoxin mouse model of myodegeneration and inflammation linked muscle pathology with mitochondrial damage and oxidative stress. In this study, we investigated whether human muscle diseases display mitochondrial changes. Muscle biopsies from muscle disease patients, represented by dysferlinopathy (dysfy) (dystrophic pathology; n = 43), polymyositis (PM) (inflammatory pathology; n = 24), and distal myopathy with rimmed vacuoles (DMRV) (distal myopathy; n = 31) were analyzed. Mitochondrial damage (ragged blue and COX-deficient fibers) was revealed in dysfy, PM, and DMRV cases by enzyme histochemistry (SDH and COX-SDH), electron microscopy (vacuolation and altered cristae) and biochemical assays (significantly increased ADP/ATP ratio). Proteomic analysis of muscle mitochondria from all three muscle diseases by isobaric tag for relative and absolute quantitation labeling and liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis demonstrated down-regulation of electron transport chain (ETC) complex subunits, assembly factors and Krebs cycle enzymes. Interestingly, 80 of the under-expressed proteins were common among the three pathologies. Assay of ETC and Krebs cycle enzyme activities validated the MS data. Mitochondrial proteins from muscle pathologies also displayed higher tryptophan (Trp) oxidation and the same was corroborated in the cardiotoxin model. Molecular modeling predicted Trp oxidation to alter the local structure of mitochondrial proteins. Our data highlight mitochondrial alterations in muscle pathologies, represented by morphological changes, altered mitochondrial proteome and protein oxidation, thereby establishing the role of mitochondrial damage in human muscle diseases. We investigated whether human muscle diseases display mitochondrial changes. Muscle biopsies from dysferlinopathy (Dysfy), polymyositis (PM), and distal myopathy with rimmed vacuoles (DMRV) displayed morphological and biochemical evidences of mitochondrial dysfunction. Proteomic analysis revealed down-regulation of electron transport chain (ETC) subunits, assembly factors, and tricarboxylic acid (TCA) cycle enzymes, with 80 proteins common among the three pathologies. Mitochondrial proteins from muscle pathologies also displayed higher Trp oxidation that could alter the local structure. Cover image for this issue: doi: 10.1111/jnc.13324. © 2016 International Society for Neurochemistry.

Analysis of tau post-translational modifications in rTg4510 mice, a model of tau pathology.

PubMed

Song, Lixin; Lu, Sherry X; Ouyang, Xuesong; Melchor, Jerry; Lee, Julie; Terracina, Giuseppe; Wang, Xiaohai; Hyde, Lynn; Hess, J Fred; Parker, Eric M; Zhang, Lili

2015-03-26

Microtubule associated protein tau is the major component of the neurofibrillary tangles (NFTs) found in the brains of patients with Alzheimer's disease and several other neurodegenerative diseases. Tau mutations are associated with frontotemperal dementia with parkinsonism on chromosome 17 (FTDP-17). rTg4510 mice overexpress human tau carrying the P301L FTDP-17 mutation and develop robust NFT-like pathology at 4-5 months of age. The current study is aimed at characterizing the rTg4510 mice to better understand the genesis of tau pathology and to better enable the use of this model in drug discovery efforts targeting tau pathology. Using a panel of immunoassays, we analyzed the age-dependent formation of pathological tau in rTg4510 mice and our data revealed a steady age-dependent accumulation of pathological tau in the insoluble fraction of brain homogenates. The pathological tau was associated with multiple post-translational modifications including aggregation, phosphorylation at a wide variety of sites, acetylation, ubiquitination and nitration. The change of most tau species reached statistical significance at the age of 16 weeks. There was a strong correlation between the different post-translationally modified tau species in this heterogeneous pool of pathological tau. Total tau in the cerebrospinal fluid (CSF) displayed a multiphasic temporal profile distinct from the steady accumulation of pathological tau in the brain. Female rTg4510 mice displayed significantly more aggressive accumulation of pathological tau in the brain and elevation of total tau in CSF than their male littermates. The immunoassays described here were used to generate the most comprehensive description of the changes in various tau species across the lifespan of the rTg4510 mouse model. The data indicate that development of tauopathy in rTg4510 mice involves the accumulation of a pool of pathological tau that carries multiple post-translational modifications, a process that can be detected well before the histological detection of NFTs. Therapeutic treatment targeting tau should therefore aim to reduce all tau species associated with the pathological tau pool rather than reduce specific post-translational modifications. There is still much to learn about CSF tau in physiological and pathological processes in order to use it as a translational biomarker in drug discovery.

Long-term treatment with EGFR inhibitor erlotinib attenuates renal inflammatory cytokines but not nephropathy in Alport syndrome mouse model.

PubMed

Omachi, Kohei; Miyakita, Rui; Fukuda, Ryosuke; Kai, Yukari; Suico, Mary Ann; Yokota, Tsubasa; Kamura, Misato; Shuto, Tsuyoshi; Kai, Hirofumi

2017-12-01

Alport syndrome (AS) is a hereditary kidney disease caused by mutation of type IV collagen. Loss of collagen network induces collapse of glomerular basement membrane (GBM) structure. The previous studies showed that upregulation of some tyrosine kinase receptors signaling accompanied GBM disorder in AS mouse model. EGFR signaling is one of the well-known receptor kinase signaling that is involved in glomerular diseases. However, whether EGFR signaling is relevant to AS progression is still uninvestigated. Here, we determined the involvement of EGFR in AS and the effect of suppressing EGFR signaling by erlotinib treatment on AS progression. Phosphorylated EGFR expression was investigated by Western blotting analysis and immunostaining of kidney tissues of Col4a5 mutant mice (a mouse model of X-linked AS). To check the effect of blocking EGFR signaling in AS, we administered erlotinib to AS mice once a day (10 mg/kg/day) orally for 18 weeks. Renal function parameters (proteinuria, serum creatinine, and BUN) and renal histology were assessed, and the gene expressions of inflammatory cytokines were analyzed in renal tissues. Phosphorylated EGFR expression was upregulated in AS mice kidney tissues. Erlotinib slightly reduced the urinary protein and suppressed the expression of renal injury markers (Lcn2, Lysozyme) and inflammatory cytokines (Il-6, Il-1β and KC). Erlotinib did not improve renal pathology, such as glomerular sclerosis and fibrosis. These findings suggest that EGFR signaling is upregulated in kidney, but although inhibiting this signaling pathway suppressed renal inflammatory cytokines, it did not ameliorate renal dysfunction in AS mouse model.

Host-Specific Response to HCV Infection in the Chimeric SCID-beige/Alb-uPA Mouse Model: Role of the Innate Antiviral Immune Response

PubMed Central

Thompson, Jill C; Smith, Maria W; Yeh, Matthew M; Proll, Sean; Zhu, Lin-Fu; Gao, T. J; Kneteman, Norman M; Tyrrell, D. Lorne; Katze, Michael G

2006-01-01

The severe combined immunodeficiency disorder (SCID)-beige/albumin (Alb)-urokinase plasminogen activator (uPA) mouse containing a human-mouse chimeric liver is currently the only small animal model capable of supporting hepatitis C virus (HCV) infection. This model was utilized to characterize the host transcriptional response to HCV infection. The purpose of these studies was to investigate the genetic component of the host response to HCV infection and also to distinguish virus-induced gene expression changes from adaptive HCV-specific immune-mediated effects. Gene expression profiles from HCV-infected mice were also compared to those from HCV-infected patients. Analyses of the gene expression data demonstrate that host factors regulate the response to HCV infection, including the nature of the innate antiviral immune response. They also indicate that HCV mediates gene expression changes, including regulation of lipid metabolism genes, which have the potential to be directly cytopathic, indicating that liver pathology may not be exclusively mediated by HCV-specific adaptive immune responses. This effect appears to be inversely related to the activation of the innate antiviral immune response. In summary, the nature of the initial interferon response to HCV infection may determine the extent of viral-mediated effects on host gene expression. PMID:16789836

Androgens affect muscle, motor neuron, and survival in a mouse model of SOD1-related amyotrophic lateral sclerosis.

PubMed

Aggarwal, Tanya; Polanco, Maria J; Scaramuzzino, Chiara; Rocchi, Anna; Milioto, Carmelo; Emionite, Laura; Ognio, Emanuela; Sambataro, Fabio; Galbiati, Mariarita; Poletti, Angelo; Pennuto, Maria

2014-08-01

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease characterized by selective loss of upper and lower motor neurons and skeletal muscle atrophy. Epidemiologic and experimental evidence suggest the involvement of androgens in ALS pathogenesis, but the mechanism through which androgens modify the ALS phenotype is unknown. Here, we show that androgen ablation by surgical castration extends survival and disease duration of a transgenic mouse model of ALS expressing mutant human SOD1 (hSOD1-G93A). Furthermore, long-term treatment of orchiectomized hSOD1-G93A mice with nandrolone decanoate (ND), an anabolic androgenic steroid, worsened disease manifestations. ND treatment induced muscle fiber hypertrophy but caused motor neuron death. ND negatively affected survival, thereby dissociating skeletal muscle pathology from life span in this ALS mouse model. Interestingly, orchiectomy decreased androgen receptor levels in the spinal cord and muscle, whereas ND treatment had the opposite effect. Notably, stimulation with ND promoted the recruitment of endogenous androgen receptor into biochemical complexes that were insoluble in sodium dodecyl sulfate, a finding consistent with protein aggregation. Overall, our results shed light on the role of androgens as modifiers of ALS pathogenesis via dysregulation of androgen receptor homeostasis. Copyright © 2014 Elsevier Inc. All rights reserved.

Pleiotrophin and N-syndecan promote perineural invasion and tumor progression in an orthotopic mouse model of pancreatic cancer

PubMed Central

Yao, Jun; Zhang, Lu-Lin; Huang, Xu-Mei; Li, Wen-Yao; Gao, She-Gan

2017-01-01

AIM To detect the expression of pleiotrophin (PTN) and N-syndecan in pancreatic cancer and analyze their association with tumor progression and perineural invasion (PNI). METHODS An orthotopic mouse model of pancreatic cancer was created by injecting tumor cells subcapsularly in a root region of the pancreas beneath the spleen. Pancreatic cancer tissues were taken from 36 mice that survived for more than 90 d. PTN and N-syndecan proteins were detected by immunohistochemistry and analyzed for their correlation with pathological features, PNI, and prognosis. RESULTS The expression rates of PTN and N-syndecan proteins were 66.7% and 61.1%, respectively, in cancer tissue. PTN and N-syndecan expression was associated with PNI (P = 0.019 and P = 0.032, respectively). High PTN expression was closely associated with large bloody ascites (P = 0.009), liver metastasis (P = 0.035), and decreased survival time (P = 0.022). N-syndecan expression was significantly associated with tumor size (P = 0.025), but not with survival time (P = 0.539). CONCLUSION High PTN and N-syndecan expression was closely associated with metastasis and poor prognosis, suggesting that they may promote tumor progression and PNI in the orthotopic mouse model of pancreatic cancer. PMID:28638231

In vivo photoacoustic imaging of mouse embryos

NASA Astrophysics Data System (ADS)

Laufer, Jan; Norris, Francesca; Cleary, Jon; Zhang, Edward; Treeby, Bradley; Cox, Ben; Johnson, Peter; Scambler, Pete; Lythgoe, Mark; Beard, Paul

2012-06-01

The ability to noninvasively image embryonic vascular anatomy in mouse models is an important requirement for characterizing the development of the normal cardiovascular system and malformations in the heart and vascular supply. Photoacoustic imaging, which can provide high resolution non invasive images of the vasculature based upon optical absorption by endogenous hemoglobin, is well suited to this application. In this study, photoacoustic images of mouse embryos were obtained ex vivo and in vivo. The images show intricate details of the embryonic vascular system to depths of up to 10 mm, which allowed whole embryos to be imaged in situ. To achieve this, an all-optical photoacoustic scanner and a novel time reversal image reconstruction algorithm, which provide deep tissue imaging capability while maintaining high spatial resolution and contrast were employed. This technology may find application as an imaging tool for preclinical embryo studies in developmental biology as well as more generally in preclinical and clinical medicine for studying pathologies characterized by changes in the vasculature.

Acquiring, recording, and analyzing pathology data from experimental mice: an overview.

PubMed

Scudamore, Cheryl L

2014-03-21

Pathology is often underutilized as an end point in mouse studies in academic research because of a lack of experience and expertise. The use of traditional pathology techniques including necropsy and microscopic analysis can be useful in identifying the basic processes underlying a phenotype and facilitating comparison with equivalent human diseases. This overview aims to provide a guide and reference to the acquisition, recording, and analysis of high-quality pathology data from experimental mice in an academic research setting. Copyright © 2014 John Wiley & Sons, Inc.

Human mesenchymal stem cells suppress donor CD4(+) T cell proliferation and reduce pathology in a humanized mouse model of acute graft-versus-host disease.

PubMed

Tobin, L M; Healy, M E; English, K; Mahon, B P

2013-05-01

Acute graft-versus-host disease (aGVHD) is a life-threatening complication following allogeneic haematopoietic stem cell transplantation (HSCT), occurring in up to 30-50% of patients who receive human leucocyte antigen (HLA)-matched sibling transplants. Current therapies for steroid refractory aGVHD are limited, with the prognosis of patients suboptimal. Mesenchymal stem or stromal cells (MSC), a heterogeneous cell population present in many tissues, display potent immunomodulatory abilities. Autologous and allogeneic ex-vivo expanded human MSC have been utilized to treat aGVHD with promising results, but the mechanisms of therapeutic action remain unclear. Here a robust humanized mouse model of aGVHD based on delivery of human peripheral blood mononuclear cells (PBMC) to non-obese diabetic (NOD)-severe combined immunodeficient (SCID) interleukin (IL)-2rγ(null) (NSG) mice was developed that allowed the exploration of the role of MSC in cell therapy. MSC therapy resulted in the reduction of liver and gut pathology and significantly increased survival. Protection was dependent upon the timing of MSC therapy, with conventional MSC proving effective only after delayed administration. In contrast, interferon (IFN)-γ-stimulated MSC were effective when delivered with PBMC. The beneficial effect of MSC therapy in this model was not due to the inhibition of donor PBMC chimerism, as CD45(+) and T cells engrafted successfully in this model. MSC therapy did not induce donor T cell anergy, FoxP3(+) T regulatory cells or cause PBMC apoptosis in this model; however, it was associated with the direct inhibition of donor CD4(+) T cell proliferation and reduction of human tumour necrosis factor-α in serum. © 2012 British Society for Immunology.

Anxiety, neuroinflammation, cholinergic and GABAergic abnormalities are early markers of Gulf War illness in a mouse model of the disease.

PubMed

Carreras, Isabel; Aytan, Nurgul; Mellott, Tiffany; Choi, Ji-Kyung; Lehar, Margaret; Crabtree, Leah; Leite-Morris, Kimberly; Jenkins, Bruce G; Blusztajn, Jan Krzysztof; Dedeoglu, Alpaslan

2018-02-15

Gulf War Illness (GWI) is a chronic disease that affects the 1991 Gulf War (GW) veterans for which treatment is lacking. It has been hypothesized that drugs used to protect military personnel from chemical attacks and insects during the war: pyridostigmine bromide (PB),N, N-diethyl-m-toluamide (DEET), and permethrin (PER) together with stress may have contributed collectively and synergistically to generate GWI. There is a need to find markers of pathology to be used in pre-clinical trials. For this purpose we employed a previously validated mouse model of GWI evoked by daily exposure to PB (1.3 mg/kg), DEET (40 mg/kg), PER (0.13 mg/kg), and 5 min of restraint stress for 28 days to analyze behavior, brain pathology and neurochemical outcomes three months later. GWI-model mice were characterized by increased anxiety, decreased hippocampal levels of N-acetyl aspartate, GABA, the GABA-producing enzyme GAD-67 and microglial activation. We also observed that GWI model was sexually dimorphic on some measures: males had increased while females had decreased protein levels of the acetylcholine-synthesizing enzyme, choline acetyltransferase, in the septum and hippocampus and decreased levels of the receptor for brain-derived neurotrophic factor, TrkB140, in the hippocampus. Increased hippocampal levels of nerve growth factor were detected in males only. Together the data show behavioral and neuropathological abnormalities detected at 3 months post-exposure and that some of them are sexually dimorphic. Future preclinical studies for GWI may take advantage of this short latency model and should include both males and females as their response to treatment may differ. Published by Elsevier B.V.

Skeletal metastasis: treatments, mouse models, and the Wnt signaling

PubMed Central

Valkenburg, Kenneth C.; Steensma, Matthew R.; Williams, Bart O.; Zhong, Zhendong

2013-01-01

Skeletal metastases result in significant morbidity and mortality. This is particularly true of cancers with a strong predilection for the bone, such as breast, prostate, and lung cancers. There is currently no reliable cure for skeletal metastasis, and palliative therapy options are limited. The Wnt signaling pathway has been found to play an integral role in the process of skeletal metastasis and may be an important clinical target. Several experimental models of skeletal metastasis have been used to find new biomarkers and test new treatments. In this review, we discuss pathologic process of bone metastasis, the roles of the Wnt signaling, and the available experimental models and treatments. PMID:23327798

Pseudoxanthoma Elasticum is a Metabolic Disease

PubMed Central

Jiang, Qiujie; Endoh, Masayuki; Dibra, Florian; Wang, Krystle; Uitto, Jouni

2011-01-01

Pseudoxanthoma elasticum (PXE) is a pleiotropic multisystem disorder affecting skin, eyes, and the cardiovascular system with progressive pathological mineralization. It is caused by mutations in the ABCC6 gene expressed primarily in the liver and kidneys, and at very low levels, if at all, in tissues affected by PXE. A question has arisen regarding the pathomechanism of PXE, particularly the “metabolic” versus the “PXE cell” hypotheses. We examined a murine PXE model (Abcc6−/−) by transplanting muzzle skin from knock-out (KO) and wild-type (WT) mice onto the back of WT and KO mice using mineralization of the connective tissue capsule surrounding the vibrissae as an early phenotypic biomarker. Grafting of WT mouse muzzle skin onto the back of KO mice resulted in mineralization of vibrissae, while grafting KO mouse muzzle skin onto the WT mice did not. Thus, these findings implicate circulatory factors as a critical component of the mineralization process. This mouse grafting model supports the notion that PXE is a systemic metabolic disorder with secondary mineralization of connective tissues and that the mineralization process can be countered or even reversed by changes in the homeostatic milieu. PMID:18685618

Murine Models for Viral Hemorrhagic Fever.

PubMed

Gonzalez-Quintial, Rosana; Baccala, Roberto

2018-01-01

Hemorrhagic fever (HF) viruses, such as Lassa, Ebola, and dengue viruses, represent major human health risks due to their highly contagious nature, the severity of the clinical manifestations induced, the lack of vaccines, and the very limited therapeutic options currently available. Appropriate animal models are obviously critical to study disease pathogenesis and develop efficient therapies. We recently reported that the clone 13 (Cl13) variant of the lymphocytic choriomeningitis virus (LCMV-Cl13), a prototype arenavirus closely related to Lassa virus, causes in some mouse strains endothelial damage, vascular leakage, platelet loss, and death, mimicking pathological aspects typically observed in Lassa and other HF syndromes. This model has the advantage that the mice used are fully immunocompetent, allowing studies on the contribution of the immune response to disease progression. Moreover, LCMV is very well characterized and exhibits limited pathogenicity in humans, allowing handling in convenient BSL-2 facilities. In this chapter we outline protocols for the induction and analysis of arenavirus-mediated pathogenesis in the NZB/LCMV model, including mouse infection, virus titer determination, platelet counting, phenotypic analysis of virus-specific T cells, and assessment of vascular permeability.

Pathological Changes in APP/PS-1 Transgenic Mouse Models of Alzheimer's Disease Treated with Ganoderma Lucidum Preparation.

PubMed

Qin, Chuan; Wu, Shan-Qiu; Chen, Bao-Sheng; Wu, Xiao-Xian; Qu, Kun-Yao; Liu, Jun-Min; Zhang, Gui-Fang; Xu, Yan-Feng; Shu, Shunli; Sun, Lihua; Li, Yan-Yong; Zhu, Hua; Huang, Lan; Ma, Chun-Mei; Xu, Yu-Huan; Han, Yun-Lin; Lu, Yao-Zeng

2017-08-20

Objective To explore the efficacy of ganoderma lucidum preparation(Ling Zhi) in treating APP/PS-1 transgenic mouse models of Alzheimer's disease(AD).Methods APP/PS-1 transgenic mice of 4 months were randomly divided into model group,ganoderma lucidum treatment groups,including high [2250 mg/(kg·d)] and middle [750 mg/(kg·d)] dose groups,i.e.LZ-H and LZ-M groups,and the positive control group(treated with donepezil hydrochloride [2 mg/(kg·d)]).In addition,C57BL/6J wild mice were selected as normal group.The animals were administered for 4 months.Histopathological examinations including hematoxylin-eosin(HE) staining,immunohistochemistry,special staining,and electron microscopy were applied,and then the pathological morphology and structures in different groups were compared. Results The senile plaques and neurofibrillar tangles in the cerebrum and cerebellum were dissolved or disappeared in LZ-H and LZ-M groups.Decrease of amyloid angiopathy was found in LZ-H and LZ-M groups.The immature neurons appeared more in hippocampus and dentate nucleus of LZ-H and LZ-M groups than those in AD model and donepezil hydrochloride groups(hippcampus:F=1.738,P=0.016;dentate nucleus:F=1.924,P=0.026),and these immature neurons differentiated to be neurons.More Purkinje cells loss occurred in AD model mice than that in LZ-H and LZ-M groups(F=9.46,P=0.007;F=9.46,P=0.010).The LZ-H and LZ-M groups had more new neuron stem cells grown up in cerebellum.Electromicroscopic examination showed the hippocampal neurons in LZ-H and LZ-M group were integrated,the nuclear membrane was intact,and the mitochondria in the cytoplasm,endoplasmic reticulum,Golgi bodies,microtubules,and synapses were also complete.The microglial cell showed no abnormality.No toxicity appeared in the pathological specimens of mice treated with ganoderma lucidum preparation.Conclusion The ganoderma lucidum preparation can dissolve and decline or dismiss the senile plaques and neurofibrillar tangles in the brain of AD mice and also reduce the amyloid angiopathy.

AAV1/2-induced overexpression of A53T-α-synuclein in the substantia nigra results in degeneration of the nigrostriatal system with Lewy-like pathology and motor impairment: a new mouse model for Parkinson's disease.

PubMed

Ip, Chi Wang; Klaus, Laura-Christin; Karikari, Akua A; Visanji, Naomi P; Brotchie, Jonathan M; Lang, Anthony E; Volkmann, Jens; Koprich, James B

2017-02-01

α-Synuclein is a protein implicated in the etiopathogenesis of Parkinson's disease (PD). AAV1/2-driven overexpression of human mutated A53T-α-synuclein in rat and monkey substantia nigra (SN) induces degeneration of nigral dopaminergic neurons and decreases striatal dopamine and tyrosine hydroxylase (TH). Given certain advantages of the mouse, especially it being amendable to genetic manipulation, translating the AAV1/2-A53T α-synuclein model to mice would be of significant value. AAV1/2-A53T α-synuclein or AAV1/2 empty vector (EV) at a concentration of 5.16 x 10 12 gp/ml were unilaterally injected into the right SN of male adult C57BL/6 mice. Post-mortem examinations included immunohistochemistry to analyze nigral α-synuclein, Ser129 phosphorylated α-synuclein and TH expression, striatal dopamine transporter (DAT) levels by autoradiography and dopamine levels by high performance liquid chromatography. At 10 weeks, in AAV1/2-A53T α-synuclein mice there was a 33% reduction in TH+ dopaminergic nigral neurons (P < 0.001), 29% deficit in striatal DAT binding (P < 0.05), 38% and 33% reductions in dopamine (P < 0.001) and DOPAC (P < 0.01) levels and a 60% increase in dopamine turnover (homovanilic acid/dopamine ratio; P < 0.001). Immunofluorescence showed that the AAV1/2-A53T α-synuclein injected mice had widespread nigral and striatal expression of vector-delivered A53T-α-synuclein. Concurrent staining with human PD SN samples using gold standard histological methodology for Lewy pathology detection by proteinase K digestion and application of specific antibody raised against human Lewy body α-synuclein (LB509) and Ser129 phosphorylated α-synuclein (81A) revealed insoluble α-synuclein aggregates in AAV1/2-A53T α-synuclein mice resembling Lewy-like neurites and bodies. In the cylinder test, we observed significant paw use asymmetry in the AAV1/2-A53T α-synuclein group when compared to EV controls at 5 and 9 weeks post injection (P < 0.001; P < 0.05). These data show that unilateral injection of AAV1/2-A53T α-synuclein into the mouse SN leads to persistent motor deficits, neurodegeneration of the nigrostriatal dopaminergic system and development of Lewy-like pathology, thereby reflecting clinical and pathological hallmarks of human PD.

Human IgG1 antibodies suppress angiogenesis in a target-independent manner

PubMed Central

Bogdanovich, Sasha; Kim, Younghee; Mizutani, Takeshi; Yasuma, Reo; Tudisco, Laura; Cicatiello, Valeria; Bastos-Carvalho, Ana; Kerur, Nagaraj; Hirano, Yoshio; Baffi, Judit Z; Tarallo, Valeria; Li, Shengjian; Yasuma, Tetsuhiro; Arpitha, Parthasarathy; Fowler, Benjamin J; Wright, Charles B; Apicella, Ivana; Greco, Adelaide; Brunetti, Arturo; Ruvo, Menotti; Sandomenico, Annamaria; Nozaki, Miho; Ijima, Ryo; Kaneko, Hiroki; Ogura, Yuichiro; Terasaki, Hiroko; Ambati, Balamurali K; Leusen, Jeanette HW; Langdon, Wallace Y; Clark, Michael R; Armour, Kathryn L; Bruhns, Pierre; Verbeek, J Sjef; Gelfand, Bradley D; De Falco, Sandro; Ambati, Jayakrishna

2016-01-01

Aberrant angiogenesis is implicated in diseases affecting nearly 10% of the world’s population. The most widely used anti-angiogenic drug is bevacizumab, a humanized IgG1 monoclonal antibody that targets human VEGFA. Although bevacizumab does not recognize mouse Vegfa, it inhibits angiogenesis in mice. Here we show bevacizumab suppressed angiogenesis in three mouse models not via Vegfa blockade but rather Fc-mediated signaling through FcγRI (CD64) and c-Cbl, impairing macrophage migration. Other approved humanized or human IgG1 antibodies without mouse targets (adalimumab, alemtuzumab, ofatumumab, omalizumab, palivizumab and tocilizumab), mouse IgG2a, and overexpression of human IgG1-Fc or mouse IgG2a-Fc, also inhibited angiogenesis in wild-type and FcγR humanized mice. This anti-angiogenic effect was abolished by Fcgr1 ablation or knockdown, Fc cleavage, IgG-Fc inhibition, disruption of Fc-FcγR interaction, or elimination of FcRγ-initated signaling. Furthermore, bevacizumab’s Fc region potentiated its anti-angiogenic activity in humanized VEGFA mice. Finally, mice deficient in FcγRI exhibited increased developmental and pathological angiogenesis. These findings reveal an unexpected anti-angiogenic function for FcγRI and a potentially concerning off-target effect of hIgG1 therapies. PMID:26918197

Osteopontin deficiency ameliorates Alport pathology by preventing tubular metabolic deficits

PubMed Central

Ding, Wen; Goncalves, Stefania; Goldstein, Bradley J.; Sabater, Alfonso L.; Kloosterboer, Amy; Ritter, Portia; Lambert, Guerline; Mendez, Armando J.

2018-01-01

Alport syndrome is a rare hereditary renal disorder with no etiologic therapy. We found that osteopontin (OPN) is highly expressed in the renal tubules of the Alport mouse and plays a causative pathological role. OPN genetic deletion ameliorated albuminuria, hypertension, tubulointerstitial proliferation, renal apoptosis, and hearing and visual deficits in the Alport mouse. In Alport renal tubules we found extensive cholesterol accumulation and increased protein expression of dynamin-3 (DNM3) and LDL receptor (LDLR) in addition to dysmorphic mitochondria with defective bioenergetics. Increased pathological cholesterol influx was confirmed by a remarkably increased uptake of injected DiI-LDL cholesterol by Alport renal tubules, and by the improved lifespan of the Alport mice when crossed with the Ldlr–/– mice with defective cholesterol influx. Moreover, OPN-deficient Alport mice demonstrated significant reduction of DNM3 and LDLR expression. In human renal epithelial cells, overexpressing DNM3 resulted in elevated LDLR protein expression and defective mitochondrial respiration. Our results suggest a potentially new pathway in Alport pathology where tubular OPN causes DNM3- and LDLR-mediated enhanced cholesterol influx and impaired mitochondrial respiration. PMID:29563333

Osteopontin deficiency ameliorates Alport pathology by preventing tubular metabolic deficits.

PubMed

Ding, Wen; Yousefi, Keyvan; Goncalves, Stefania; Goldstein, Bradley J; Sabater, Alfonso L; Kloosterboer, Amy; Ritter, Portia; Lambert, Guerline; Mendez, Armando J; Shehadeh, Lina A

2018-03-22

Alport syndrome is a rare hereditary renal disorder with no etiologic therapy. We found that osteopontin (OPN) is highly expressed in the renal tubules of the Alport mouse and plays a causative pathological role. OPN genetic deletion ameliorated albuminuria, hypertension, tubulointerstitial proliferation, renal apoptosis, and hearing and visual deficits in the Alport mouse. In Alport renal tubules we found extensive cholesterol accumulation and increased protein expression of dynamin-3 (DNM3) and LDL receptor (LDLR) in addition to dysmorphic mitochondria with defective bioenergetics. Increased pathological cholesterol influx was confirmed by a remarkably increased uptake of injected DiI-LDL cholesterol by Alport renal tubules, and by the improved lifespan of the Alport mice when crossed with the Ldlr-/- mice with defective cholesterol influx. Moreover, OPN-deficient Alport mice demonstrated significant reduction of DNM3 and LDLR expression. In human renal epithelial cells, overexpressing DNM3 resulted in elevated LDLR protein expression and defective mitochondrial respiration. Our results suggest a potentially new pathway in Alport pathology where tubular OPN causes DNM3- and LDLR-mediated enhanced cholesterol influx and impaired mitochondrial respiration.

Dantrolene is neuroprotective in Huntington's disease transgenic mouse model.

PubMed

Chen, Xi; Wu, Jun; Lvovskaya, Svetlana; Herndon, Emily; Supnet, Charlene; Bezprozvanny, Ilya

2011-11-25

Huntington's disease (HD) is a progressive neurodegenerative disorder caused by a polyglutamine expansion in the Huntingtin protein which results in the selective degeneration of striatal medium spiny neurons (MSNs). Our group has previously demonstrated that calcium (Ca2+) signaling is abnormal in MSNs from the yeast artificial chromosome transgenic mouse model of HD (YAC128). Moreover, we demonstrated that deranged intracellular Ca2+ signaling sensitizes YAC128 MSNs to glutamate-induced excitotoxicity when compared to wild type (WT) MSNs. In previous studies we also observed abnormal neuronal Ca2+ signaling in neurons from spinocerebellar ataxia 2 (SCA2) and spinocerebellar ataxia 3 (SCA3) mouse models and demonstrated that treatment with dantrolene, a ryanodine receptor antagonist and clinically relevant Ca2+ signaling stabilizer, was neuroprotective in experiments with these mouse models. The aim of the current study was to evaluate potential beneficial effects of dantrolene in experiments with YAC128 HD mouse model. The application of caffeine and glutamate resulted in increased Ca2+ release from intracellular stores in YAC128 MSN cultures when compared to WT MSN cultures. Pre-treatment with dantrolene protected YAC128 MSNs from glutamate excitotoxicty, with an effective concentration of 100 nM and above. Feeding dantrolene (5 mg/kg) twice a week to YAC128 mice between 2 months and 11.5 months of age resulted in significantly improved performance in the beam-walking and gait-walking assays. Neuropathological analysis revealed that long-term dantrolene feeding to YAC128 mice significantly reduced the loss of NeuN-positive striatal neurons and reduced formation of Httexp nuclear aggregates. Our results support the hypothesis that deranged Ca2+ signaling plays an important role in HD pathology. Our data also implicate the RyanRs as a potential therapeutic target for the treatment of HD and demonstrate that RyanR inhibitors and Ca2+ signaling stabilizers such as dantrolene should be considered as potential therapeutics for the treatment of HD and other polyQ-expansion disorders.

Dantrolene is neuroprotective in Huntington's disease transgenic mouse model

PubMed Central

2011-01-01

Background Huntington's disease (HD) is a progressive neurodegenerative disorder caused by a polyglutamine expansion in the Huntingtin protein which results in the selective degeneration of striatal medium spiny neurons (MSNs). Our group has previously demonstrated that calcium (Ca2+) signaling is abnormal in MSNs from the yeast artificial chromosome transgenic mouse model of HD (YAC128). Moreover, we demonstrated that deranged intracellular Ca2+ signaling sensitizes YAC128 MSNs to glutamate-induced excitotoxicity when compared to wild type (WT) MSNs. In previous studies we also observed abnormal neuronal Ca2+ signaling in neurons from spinocerebellar ataxia 2 (SCA2) and spinocerebellar ataxia 3 (SCA3) mouse models and demonstrated that treatment with dantrolene, a ryanodine receptor antagonist and clinically relevant Ca2+ signaling stabilizer, was neuroprotective in experiments with these mouse models. The aim of the current study was to evaluate potential beneficial effects of dantrolene in experiments with YAC128 HD mouse model. Results The application of caffeine and glutamate resulted in increased Ca2+ release from intracellular stores in YAC128 MSN cultures when compared to WT MSN cultures. Pre-treatment with dantrolene protected YAC128 MSNs from glutamate excitotoxicty, with an effective concentration of 100 nM and above. Feeding dantrolene (5 mg/kg) twice a week to YAC128 mice between 2 months and 11.5 months of age resulted in significantly improved performance in the beam-walking and gait-walking assays. Neuropathological analysis revealed that long-term dantrolene feeding to YAC128 mice significantly reduced the loss of NeuN-positive striatal neurons and reduced formation of Httexp nuclear aggregates. Conclusions Our results support the hypothesis that deranged Ca2+ signaling plays an important role in HD pathology. Our data also implicate the RyanRs as a potential therapeutic target for the treatment of HD and demonstrate that RyanR inhibitors and Ca2+ signaling stabilizers such as dantrolene should be considered as potential therapeutics for the treatment of HD and other polyQ-expansion disorders. PMID:22118545

Synergistically increased ILC2 and Th9 cells in lung tissue jointly promote the pathological process of asthma in mice.

PubMed

Ying, Xinyu; Su, Zhaoliang; Bie, Qingli; Zhang, Pan; Yang, Huijian; Wu, Yumin; Xu, Yunyun; Wu, Jing; Zhang, Mengying; Wang, Shengjun; Xu, Huaxi

2016-06-01

In recent years, T helper (Th) 9 cells have been demonstrated to be key mediators in immune responses in asthmatic lungs, and innate lymphoid cells 2 (ILC2s) have been described as a novel type of innate immunocyte with the ability to enhance immunoglobulin E (IgE) production. However, the interaction between ILC2s and Th9 cells in the pulmonary system of a mouse model of asthma remains to be elucidated. In the present study, the response state of lung tissue with regards to Th9 and ILC2s in a mouse model of asthma was investigated by detecting Th9‑ and ILC2‑associated cytokine receptors. The present study also investigated the association between the expression levels of the cytokine receptors in lung tissue samples and the IgE levels in sera samples from mouse models of asthma. Results from the present study demonstrated that the frequency of ILC2s and Th9 cells was significantly increased in the lung tissue samples, indicating that a Th2-type immune response had occurred. In addition, high mRNA expression levels of RAR‑related orphan receptor α, interleukin 1 receptor‑like 1, transcription factor PU.1 and interleukin (IL)‑9 were observed. Furthermore, IL‑5Rα, IL‑13Rα2 and high‑affinity IgE receptor were increased in mouse models of asthma, and a positive association was observed between the expression levels of ILC2‑ or Th9‑associated receptors in tissue samples and IgE levels in the sera. This indicated that ILC2s and Th9 were in a state of polarization and may promote each other in the lung tissue of mouse models of asthma, and that the lung tissue was responding to the two types of cells via increased expression of receptors.

The role of renal proximal tubule P450 enzymes in chloroform-induced nephrotoxicity: Utility of renal specific P450 reductase knockout mouse models

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

Liu, Senyan; Wadsworth Center, New York State Department of Health, and School of Public Health, State University of New York, Albany, NY 12201; Yao, Yunyi

The kidney is a primary target for numerous toxic compounds. Cytochrome P450 enzymes (P450) are responsible for the metabolic activation of various chemical compounds, and in the kidney are predominantly expressed in proximal tubules. The aim of this study was to test the hypothesis that renal proximal tubular P450s are critical for nephrotoxicity caused by chemicals such as chloroform. We developed two new mouse models, one having proximal tubule-specific deletion of the cytochrome P450 reductase (Cpr) gene (the enzyme required for all microsomal P450 activities), designated proximal tubule-Cpr-null (PTCN), and the other having proximal tubule-specific rescue of CPR activity withmore » the global suppression of CPR activity in all extra-proximal tubular tissues, designated extra-proximal tubule-Cpr-low (XPT-CL). The PTCN, XPT-CL, Cpr-low (CL), and wild-type (WT) mice were treated with a single oral dose of chloroform at 200 mg/kg. Blood, liver and kidney samples were obtained at 24 h after the treatment. Renal toxicity was assessed by measuring BUN and creatinine levels, and by pathological examination. The blood and tissue levels of chloroform were determined. The severity of toxicity was less in PTCN and CL mice, compared with that of WT and XPT-CL mice. There were no significant differences in chloroform levels in the blood, liver, or kidney, between PTCN and WT mice, or between XPT-CL and CL mice. These findings indicate that local P450-dependent activities play an important role in the nephrotoxicity induced by chloroform. Our results also demonstrate the usefulness of these novel mouse models for studies of chemical-induced kidney toxicity. - Highlights: • New mouse models were developed with varying P450 activities in the proximal tubule. • These mouse models were treated with chloroform, a nephrotoxicant. • Studies showed the importance of local P450s in chloroform-induced nephrotoxicity.« less

Models of tibial fracture healing in normal and Nf1-deficient mice.

PubMed

Schindeler, Aaron; Morse, Alyson; Harry, Lorraine; Godfrey, Craig; Mikulec, Kathy; McDonald, Michelle; Gasser, Jürg A; Little, David G

2008-08-01

Delayed union and nonunion are common complications associated with tibial fractures, particularly in the distal tibia. Existing mouse tibial fracture models are typically closed and middiaphyseal, and thus poorly recapitulate the prevailing conditions following surgery on a human open distal tibial fracture. This report describes our development of two open tibial fracture models in the mouse, where the bone is broken either in the tibial midshaft (mid-diaphysis) or in the distal tibia. Fractures in the distal tibial model showed delayed repair compared to fractures in the tibial midshaft. These tibial fracture models were applied to both wild-type and Nf1-deficient (Nf1+/-) mice. Bone repair has been reported to be exceptionally problematic in human NF1 patients, and these patients can also spontaneously develop tibial nonunions (known as congenital pseudarthrosis of the tibia), which are recalcitrant to even vigorous intervention. pQCT analysis confirmed no fundamental differences in cortical or cancellous bone in Nf1-deficient mouse tibiae compared to wild-type mice. Although no difference in bone healing was seen in the tibial midshaft fracture model, the healing of distal tibial fractures was found to be impaired in Nf1+/- mice. The histological features associated with nonunited Nf1+/- fractures were variable, but included delayed cartilage removal, disproportionate fibrous invasion, insufficient new bone anabolism, and excessive catabolism. These findings imply that the pathology of tibial pseudarthrosis in human NF1 is complex and likely to be multifactorial.

Tauroursodeoxycholic acid, a bile acid, is neuroprotective in a transgenic animal model of Huntington's disease

PubMed Central

Keene, C. Dirk; Rodrigues, Cecilia M. P.; Eich, Tacjana; Chhabra, Manik S.; Steer, Clifford J.; Low, Walter C.

2002-01-01

Huntington's disease (HD) is an untreatable neurological disorder caused by selective and progressive degeneration of the caudate nucleus and putamen of the basal ganglia. Although the etiology of HD pathology is not fully understood, the observed loss of neuronal cells is thought to occur primarily through apoptosis. Furthermore, there is evidence in HD that cell death is mediated through mitochondrial pathways, and mitochondrial deficits are commonly associated with HD. We have previously reported that treatment with tauroursodeoxycholic acid (TUDCA), a hydrophilic bile acid, prevented neuropathology and associated behavioral deficits in the 3-nitropropionic acid rat model of HD. We therefore examined whether TUDCA would also be neuroprotective in a genetic mouse model of HD. Our results showed that systemically administered TUDCA led to a significant reduction in striatal neuropathology of the R6/2 transgenic HD mouse. Specifically, R6/2 mice began receiving TUDCA at 6 weeks of age and exhibited reduced striatal atrophy, decreased striatal apoptosis, as well as fewer and smaller size ubiquitinated neuronal intranuclear huntingtin inclusions. Moreover, locomotor and sensorimotor deficits were significantly improved in the TUDCA-treated mice. In conclusion, TUDCA is a nontoxic, endogenously produced hydrophilic bile acid that is neuroprotective in a transgenic mouse model of HD and, therefore, may provide a novel and effective treatment in patients with HD. PMID:12149470

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

PubMed

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

2018-02-26

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

Stereotactic Body Radiation Therapy Delivery in a Genetically Engineered Mouse Model of Lung Cancer.

PubMed

Du, Shisuo; Lockamy, Virginia; Zhou, Lin; Xue, Christine; LeBlanc, Justin; Glenn, Shonna; Shukla, Gaurav; Yu, Yan; Dicker, Adam P; Leeper, Dennis B; Lu, You; Lu, Bo

2016-11-01

To implement clinical stereotactic body radiation therapy (SBRT) using a small animal radiation research platform (SARRP) in a genetically engineered mouse model of lung cancer. A murine model of multinodular Kras-driven spontaneous lung tumors was used for this study. High-resolution cone beam computed tomography (CBCT) imaging was used to identify and target peripheral tumor nodules, whereas off-target lung nodules in the contralateral lung were used as a nonirradiated control. CBCT imaging helps localize tumors, facilitate high-precision irradiation, and monitor tumor growth. SBRT planning, prescription dose, and dose limits to normal tissue followed the guidelines set by RTOG protocols. Pathologic changes in the irradiated tumors were investigated using immunohistochemistry. The image guided radiation delivery using the SARRP system effectively localized and treated lung cancer with precision in a genetically engineered mouse model of lung cancer. Immunohistochemical data confirmed the precise delivery of SBRT to the targeted lung nodules. The 60 Gy delivered in 3 weekly fractions markedly reduced the proliferation index, Ki-67, and increased apoptosis per staining for cleaved caspase-3 in irradiated lung nodules. It is feasible to use the SARRP platform to perform dosimetric planning and delivery of SBRT in mice with lung cancer. This allows for preclinical studies that provide a rationale for clinical trials involving SBRT, especially when combined with immunotherapeutics. Copyright © 2016. Published by Elsevier Inc.

Genetic Ablation of Apolipoprotein A-IV Accelerates Alzheimer's Disease Pathogenesis in a Mouse Model

PubMed Central

Cui, Yujie; Huang, Mingwei; He, Yingbo; Zhang, Shuyan; Luo, Yongzhang

2011-01-01

The link between lipoprotein metabolism and Alzheimer's disease (AD) has been established. Apolipoprotein A-IV (apoA-IV), a component of lipoprotein particles similar to apolipoprotein E, has been suggested to play an important role in brain metabolism. Although there are clinical debates on the function of its polymorphism in AD, the pathologic role of apoA-IV in AD is still unknown. Here, we report that genetic ablation of apoA-IV is able to accelerate AD pathogenesis in mice. In a mouse model that overexpresses human amyloid precursor protein (APP) and presenilin 1, genetic reduction of apoA-IV augments extracellular amyloid-β peptide (Aβ) burden and aggravates neuron loss in the brain. In addition, genetic ablation of apoA-IV also accelerates spatial learning deficits and increases the mortality of mice. We have found that apoA-IV colocalizes within Aβ plaques in APP/presenilin 1 transgenic mice and binds to Aβ in vitro. Subsequent studies show that apoA-IV in this model facilitates Aβ uptake in the Aβ clearance pathway mediated by astrocytes rather than the amyloidogenic pathway of APP processing. Taken together, we conclude that apoA-IV deficiency increases Aβ deposition and results in cognitive damage in the mouse model. Enhancing levels of apoA-IV may have therapeutic potential in AD treatment. PMID:21356380

A Battery of Motor Tests in a Neonatal Mouse Model of Cerebral Palsy.

PubMed

Feather-Schussler, Danielle N; Ferguson, Tanya S

2016-11-03

As the sheer number of transgenic mice strains grow and rodent models of pediatric disease increase, there is an expanding need for a comprehensive, standardized battery of neonatal mouse motor tests. These tests can validate injury or disease models, determine treatment efficacy and/or assess motor behaviors in new transgenic strains. This paper presents a series of neonatal motor tests to evaluate general motor function, including ambulation, hindlimb foot angle, surface righting, negative geotaxis, front- and hindlimb suspension, grasping reflex, four limb grip strength and cliff aversion. Mice between the ages of post-natal day 2 to 14 can be used. In addition, these tests can be used for a wide range of neurological and neuromuscular pathologies, including cerebral palsy, hypoxic-ischemic encephalopathy, traumatic brain injury, spinal cord injury, neurodegenerative diseases, and neuromuscular disorders. These tests can also be used to determine the effects of pharmacological agents, as well as other types of therapeutic interventions. In this paper, motor deficits were evaluated in a novel neonatal mouse model of cerebral palsy that combines hypoxia, ischemia and inflammation. Forty-eight hours after injury, five tests out of the nine showed significant motor deficits: ambulation, hindlimb angle, hindlimb suspension, four limb grip strength, and grasping reflex. These tests revealed weakness in the hindlimbs, as well as fine motor skills such as grasping, which are similar to the motor deficits seen in human cerebral palsy patients.

Molecular Mechanisms Underlying the Epileptogenesis and Seizure Progression in Tuberous Sclerosis Complex 1 Deficient Mouse Models

DTIC Science & Technology

2016-10-01

growth and metabolism known as mammalian target of rapamycin complex 1 (mTORC1). The pathological hallmark of TSC brains are cortical tubers...molecule players that respond to or do not respond to mTORC1 inhibitors. We will examine the effects of rapamycin on the molecular changes associated...ribosome profiling and conventional ribosome profiling. Ligation-Free Ribosome Profiling in CamK2a-Cre Tsc1fl/fl Mice following Rapamycin Treatment One

Vinpocetine Attenuates Pathological Cardiac Remodeling by Inhibiting Cardiac Hypertrophy and Fibrosis

PubMed Central

Wu, Mei-ping; Zhang, Yi-shuai; Xu, Xiangbin; Zhou, Qian

2017-01-01

Purpose Pathological cardiac remodeling, characterized by cardiac hypertrophy and fibrosis, is a pathological feature of many cardiac disorders that leads to heart failure and cardiac arrest. Vinpocetine, a derivative of the alkaloid vincamine, has been used for enhancing cerebral blood flow to treat cognitive impairment. However, its role in pathological cardiac remodeling remains unknown. The aim of this study is to examine the effect of vinpocetine on pathological cardiac remodeling induced by chronic stimulation with angiotensin II (Ang II). Methods Mice received Ang II infusion via osmotic pumps in the presence of vehicle or vinpocetine. Cardiac hypertrophy and fibrosis were assessed by morphological, histological, and biochemical analyses. Mechanistic studies were carried out in vitro with isolated mouse adult cardiac myocytes and fibroblasts. Results We showed that chronic Ang II infusion caused cardiac hypertrophy and fibrosis, which were all significantly attenuated by systemic administration of vinpocetine. In isolated adult mouse cardiomyocytes, vinpocetine suppressed Ang II-stimulated myocyte hypertrophic growth. In cultured cardiac fibroblasts, vinpocetine suppressed TGFβ-induced fibroblast activation and matrix gene expression, consistent with its effect in attenuating cardiac fibrosis. The effects of vinpocetine on cardiac myocyte hypertrophy and fibroblast activation are likely mediated by targeting cyclic nucleotide phosphodiesterase 1 (PDE1). Conclusions Our results reveal a novel protective effect of vinpocetine in attenuating pathological cardiac remodeling through suppressing cardiac myocyte hypertrophic growth and fibroblast activation and fibrotic gene expression. These studies may also shed light on developing novel therapeutic agents for antagonizing pathological cardiac remodeling. PMID:28321644

Vinpocetine Attenuates Pathological Cardiac Remodeling by Inhibiting Cardiac Hypertrophy and Fibrosis.

PubMed

Wu, Mei-Ping; Zhang, Yi-Shuai; Xu, Xiangbin; Zhou, Qian; Li, Jian-Dong; Yan, Chen

2017-04-01

Pathological cardiac remodeling, characterized by cardiac hypertrophy and fibrosis, is a pathological feature of many cardiac disorders that leads to heart failure and cardiac arrest. Vinpocetine, a derivative of the alkaloid vincamine, has been used for enhancing cerebral blood flow to treat cognitive impairment. However, its role in pathological cardiac remodeling remains unknown. The aim of this study is to examine the effect of vinpocetine on pathological cardiac remodeling induced by chronic stimulation with angiotensin II (Ang II). Mice received Ang II infusion via osmotic pumps in the presence of vehicle or vinpocetine. Cardiac hypertrophy and fibrosis were assessed by morphological, histological, and biochemical analyses. Mechanistic studies were carried out in vitro with isolated mouse adult cardiac myocytes and fibroblasts. We showed that chronic Ang II infusion caused cardiac hypertrophy and fibrosis, which were all significantly attenuated by systemic administration of vinpocetine. In isolated adult mouse cardiomyocytes, vinpocetine suppressed Ang II-stimulated myocyte hypertrophic growth. In cultured cardiac fibroblasts, vinpocetine suppressed TGFβ-induced fibroblast activation and matrix gene expression, consistent with its effect in attenuating cardiac fibrosis. The effects of vinpocetine on cardiac myocyte hypertrophy and fibroblast activation are likely mediated by targeting cyclic nucleotide phosphodiesterase 1 (PDE1). Our results reveal a novel protective effect of vinpocetine in attenuating pathological cardiac remodeling through suppressing cardiac myocyte hypertrophic growth and fibroblast activation and fibrotic gene expression. These studies may also shed light on developing novel therapeutic agents for antagonizing pathological cardiac remodeling.

Three-dimensional optical coherence micro-elastography of skeletal muscle tissue

PubMed Central

Chin, Lixin; Kennedy, Brendan F.; Kennedy, Kelsey M.; Wijesinghe, Philip; Pinniger, Gavin J.; Terrill, Jessica R.; McLaughlin, Robert A.; Sampson, David D.

2014-01-01

In many muscle pathologies, impairment of skeletal muscle function is closely linked to changes in the mechanical properties of the muscle constituents. Optical coherence micro-elastography (OCME) uses optical coherence tomography (OCT) imaging of tissue under a quasi-static, compressive mechanical load to map variations in tissue mechanical properties on the micro-scale. We present the first study of OCME on skeletal muscle tissue. We show that this technique can resolve features of muscle tissue including fibers, fascicles and tendon, and can also detect necrotic lesions in skeletal muscle from the mdx mouse model of Duchenne muscular dystrophy. In many instances, OCME provides better or additional contrast complementary to that provided by OCT. These results suggest that OCME could provide new understanding and opportunity for assessment of skeletal muscle pathologies. PMID:25401023

Mouse models for the study of postnatal cardiac hypertrophy.

PubMed

Del Olmo-Turrubiarte, A; Calzada-Torres, A; Díaz-Rosas, G; Palma-Lara, I; Sánchez-Urbina, R; Balderrábano-Saucedo, N A; González-Márquez, H; Garcia-Alonso, P; Contreras-Ramos, A

2015-06-01

The main objective of this study was to create a postnatal model for cardiac hypertrophy (CH), in order to explain the mechanisms that are present in childhood cardiac hypertrophy. Five days after implantation, intraperitoneal (IP) isoproterenol (ISO) was injected for 7 days to pregnant female mice. The fetuses were obtained at 15, 17 and 19 dpc from both groups, also newborns (NB), neonates (7-15 days) and young adults (6 weeks of age). Histopathological exams were done on the hearts. Immunohistochemistry and western blot demonstrated GATA4 and PCNA protein expression, qPCR real time the mRNA of adrenergic receptors (α-AR and β-AR), alpha and beta myosins (α-MHC, β-MHC) and GATA4. After the administration of ISO, there was no change in the number of offsprings. We observed significant structural changes in the size of the offspring hearts. Morphometric analysis revealed an increase in the size of the left ventricular wall and interventricular septum (IVS). Histopathological analysis demonstrated loss of cellular compaction and presence of left ventricular small fibrous foci after birth. Adrenergic receptors might be responsible for changing a physiological into a pathological hypertrophy. However GATA4 seemed to be the determining factor in the pathology. A new animal model was established for the study of pathologic CH in early postnatal stages.

Alzheimer's disease pathological lesions activate the spleen tyrosine kinase.

PubMed

Schweig, Jonas Elias; Yao, Hailan; Beaulieu-Abdelahad, David; Ait-Ghezala, Ghania; Mouzon, Benoit; Crawford, Fiona; Mullan, Michael; Paris, Daniel

2017-09-06

The pathology of Alzheimer's disease (AD) is characterized by dystrophic neurites (DNs) surrounding extracellular Aβ-plaques, microgliosis, astrogliosis, intraneuronal tau hyperphosphorylation and aggregation. We have previously shown that inhibition of the spleen tyrosine kinase (Syk) lowers Aβ production and tau hyperphosphorylation in vitro and in vivo. Here, we demonstrate that Aβ-overexpressing Tg PS1/APPsw, Tg APPsw mice, and tau overexpressing Tg Tau P301S mice exhibit a pathological activation of Syk compared to wild-type littermates. Syk activation is occurring in a subset of microglia and is age-dependently increased in Aβ-plaque-associated dystrophic neurites of Tg PS1/APPsw and Tg APPsw mice. In Tg Tau P301S mice, a pure model of tauopathy, activated Syk occurs in neurons that show an accumulation of misfolded and hyperphosphorylated tau in the cortex and hippocampus. Interestingly, the tau pathology is exacerbated in neurons that display high levels of Syk activation supporting a role of Syk in the formation of tau pathological species in vivo. Importantly, human AD brain sections show both pathological Syk activation in DNs around Aβ deposits and in neurons immunopositive for pathological tau species recapitulating the data obtained in transgenic mouse models of AD. Additionally, we show that Syk overexpression leads to increased tau accumulation and promotes tau hyperphosphorylation at multiple epitopes in human neuron-like SH-SY5Y cells, further supporting a role of Syk in the formation of tau pathogenic species. Collectively, our data show that Syk activation occurs following Aβ deposition and the formation of tau pathological species. Given that we have previously shown that Syk activation also promotes Aβ formation and tau hyperphosphorylation, our data suggest that AD pathological lesions may be self-propagating via a Syk dependent mechanism highlighting Syk as an attractive therapeutic target for the treatment of AD.

A53T-α-synuclein overexpression in murine locus coeruleus induces Parkinson's disease-like pathology in neurons and glia.

PubMed

Henrich, Martin Timo; Geibl, Fanni Fruzsina; Lee, Bolam; Chiu, Wei-Hua; Koprich, James Benjamin; Brotchie, Jonathan Michael; Timmermann, Lars; Decher, Niels; Matschke, Lina Anita; Oertel, Wolfgang Hermann

2018-05-10

Degeneration of noradrenergic locus coeruleus neurons occurs during the prodromal phase of Parkinson's disease and contributes to a variety of non-motor symptoms, e.g. depression, anxiety and REM sleep behavior disorder. This study was designed to establish the first locus coeruleus α-synucleinopathy mouse model, which should provide sufficient information about the time-course of noradrenergic neurodegeneration, replicate cardinal histopathological features of the human Parkinson's disease neuropathology and finally lead to robust histological markers, which are sufficient to assess the pathological changes in a quantitative and qualitative way. We show that targeted viral vector-mediated overexpression of human mutant A53T-α-synuclein in vivo in locus coeruleus neurons of wild-type mice resulted in progressive noradrenergic neurodegeneration over a time frame of 9 weeks. Observed neuronal cell loss was accompanied by progressive α-synuclein phosphorylation, formation of proteinase K-resistant α-synuclein-aggregates, accumulation of Ubi-1- and p62-positive inclusions in microglia and induction of progressive micro- and astrogliosis. Apart from this local pathology, abundant α-synuclein-positive axons were found in locus coeruleus output regions, indicating rapid anterograde axonal transport of A53T-α-synuclein. Taken together, we present the first model of α-synucleinopathy in the murine locus coeruleus, replicating essential morphological features of human Parkinson's disease pathology. This new model may contribute to the research on prodromal Parkinson's disease, in respect to pathophysiology and the development of disease-modifying therapy.

Peroxisomes in brain development and function☆

PubMed Central

Berger, Johannes; Dorninger, Fabian; Forss-Petter, Sonja; Kunze, Markus

2016-01-01

Peroxisomes contain numerous enzymatic activities that are important for mammalian physiology. Patients lacking either all peroxisomal functions or a single enzyme or transporter function typically develop severe neurological deficits, which originate from aberrant development of the brain, demyelination and loss of axonal integrity, neuroinflammation or other neurodegenerative processes. Whilst correlating peroxisomal properties with a compilation of pathologies observed in human patients and mouse models lacking all or individual peroxisomal functions, we discuss the importance of peroxisomal metabolites and tissue- and cell type-specific contributions to the observed brain pathologies. This enables us to deconstruct the local and systemic contribution of individual metabolic pathways to specific brain functions. We also review the recently discovered variability of pathological symptoms in cases with unexpectedly mild presentation of peroxisome biogenesis disorders. Finally, we explore the emerging evidence linking peroxisomes to more common neurological disorders such as Alzheimer’s disease, autism and amyotrophic lateral sclerosis. This article is part of a Special Issue entitled: Peroxisomes edited by Ralf Erdmann. PMID:26686055

Cerebral vascular amyloid seeds drive amyloid β-protein fibril assembly with a distinct anti-parallel structure

PubMed Central

Xu, Feng; Fu, Ziao; Dass, Sharmila; Kotarba, AnnMarie E.; Davis, Judianne; Smith, Steven O.; Van Nostrand, William E.

2016-01-01

Cerebrovascular accumulation of amyloid β-protein (Aβ), a condition known as cerebral amyloid angiopathy (CAA), is a common pathological feature of patients with Alzheimer's disease. Familial Aβ mutations, such as Dutch-E22Q and Iowa-D23N, can cause severe cerebrovascular accumulation of amyloid that serves as a potent driver of vascular cognitive impairment and dementia. The distinctive features of vascular amyloid that underlie its unique pathological properties remain unknown. Here, we use transgenic mouse models producing CAA mutants (Tg-SwDI) or overproducing human wild-type Aβ (Tg2576) to demonstrate that CAA-mutant vascular amyloid influences wild-type Aβ deposition in brain. We also show isolated microvascular amyloid seeds from Tg-SwDI mice drive assembly of human wild-type Aβ into distinct anti-parallel β-sheet fibrils. These findings indicate that cerebrovascular amyloid can serve as an effective scaffold to promote rapid assembly and strong deposition of Aβ into a unique structure that likely contributes to its distinctive pathology. PMID:27869115

Transcriptional profiling and biomarker identification reveal tissue specific effects of expanded ataxin-3 in a spinocerebellar ataxia type 3 mouse model.

PubMed

Toonen, Lodewijk J A; Overzier, Maurice; Evers, Melvin M; Leon, Leticia G; van der Zeeuw, Sander A J; Mei, Hailiang; Kielbasa, Szymon M; Goeman, Jelle J; Hettne, Kristina M; Magnusson, Olafur Th; Poirel, Marion; Seyer, Alexandre; 't Hoen, Peter A C; van Roon-Mom, Willeke M C

2018-06-22

Spinocerebellar ataxia type 3 (SCA3) is a progressive neurodegenerative disorder caused by expansion of the polyglutamine repeat in the ataxin-3 protein. Expression of mutant ataxin-3 is known to result in transcriptional dysregulation, which can contribute to the cellular toxicity and neurodegeneration. Since the exact causative mechanisms underlying this process have not been fully elucidated, gene expression analyses in brains of transgenic SCA3 mouse models may provide useful insights. Here we characterised the MJD84.2 SCA3 mouse model expressing the mutant human ataxin-3 gene using a multi-omics approach on brain and blood. Gene expression changes in brainstem, cerebellum, striatum and cortex were used to study pathological changes in brain, while blood gene expression and metabolites/lipids levels were examined as potential biomarkers for disease. Despite normal motor performance at 17.5 months of age, transcriptional changes in brain tissue of the SCA3 mice were observed. Most transcriptional changes occurred in brainstem and striatum, whilst cerebellum and cortex were only modestly affected. The most significantly altered genes in SCA3 mouse brain were Tmc3, Zfp488, Car2, and Chdh. Based on the transcriptional changes, α-adrenergic and CREB pathways were most consistently altered for combined analysis of the four brain regions. When examining individual brain regions, axon guidance and synaptic transmission pathways were most strongly altered in striatum, whilst brainstem presented with strongest alterations in the pi-3 k cascade and cholesterol biosynthesis pathways. Similar to other neurodegenerative diseases, reduced levels of tryptophan and increased levels of ceramides, di- and triglycerides were observed in SCA3 mouse blood. The observed transcriptional changes in SCA3 mouse brain reveal parallels with previous reported neuropathology in patients, but also shows brain region specific effects as well as involvement of adrenergic signalling and CREB pathway changes in SCA3. Importantly, the transcriptional changes occur prior to onset of motor- and coordination deficits.

Angiography reveals novel features of the retinal vasculature in healthy and diabetic mice.

PubMed

McLenachan, Samuel; Magno, Aaron Len; Ramos, David; Catita, Joana; McMenamin, Paul G; Chen, Fred Kuanfu; Rakoczy, Elizabeth Piroska; Ruberte, Jesus

2015-09-01

The mouse retina is a commonly used animal model for the study of pathogenesis and treatment of blinding retinal vascular diseases such as diabetic retinopathy. In this study, we aimed to characterize normal and pathological variations in vascular anatomy in the mouse retina using fluorescein angiography visualized with scanning laser ophthalmoscopy and optical coherence tomography (SLO-OCT). We examined eyes from C57BL/6J wild type mice as well as the Ins2(Akita) and Akimba mouse models of diabetic retinopathy using the Heidelberg Retinal Angiography (HRA) and OCT system. Angiography was performed on three focal planes to examine distinct vascular layers. For comparison with angiographic data, ex vivo analyses, including Indian ink angiography, histology and 3D confocal scanning laser microscopy were performed in parallel. All layers of the mouse retinal vasculature could be readily visualized during fluorescein angiography by SLO-OCT. Blood vessel density was increased in the deep vascular plexus (DVP) compared with the superficial vascular plexus (SVP). Arteriolar and venular typologies were established and structural differences were observed between venular types. Unexpectedly, the hyaloid artery was found to persist in 15% of C57BL/6 mice, forming anastomoses with peripheral retinal capillaries. Fluorescein leakage was easily detected in Akimba retinae by angiography, but was not observed in Ins2(Akita) mice. Blood vessel density was increased in the DVP of 6 month old Ins2(Akita) mice, while the SVP displayed reduced branching in precapillary arterioles. In summary, we present the first comprehensive characterization of the mouse retinal vasculature by SLO-OCT fluorescein angiography. Using this clinical imaging technique, we report previously unrecognized variations in C57BL/6J vascular anatomy and novel features of vascular retinopathy in the Ins2(Akita) mouse model of diabetes. Crown Copyright © 2015. Published by Elsevier Ltd. All rights reserved.

Characterization and Demonstration of the Value of a Lethal Mouse Model of Middle East Respiratory Syndrome Coronavirus Infection and Disease.

PubMed

Tao, Xinrong; Garron, Tania; Agrawal, Anurodh Shankar; Algaissi, Abdullah; Peng, Bi-Hung; Wakamiya, Maki; Chan, Teh-Sheng; Lu, Lu; Du, Lanying; Jiang, Shibo; Couch, Robert B; Tseng, Chien-Te K

2016-01-01

Characterized animal models are needed for studying the pathogenesis of and evaluating medical countermeasures for persisting Middle East respiratory syndrome-coronavirus (MERS-CoV) infections. Here, we further characterized a lethal transgenic mouse model of MERS-CoV infection and disease that globally expresses human CD26 (hCD26)/DPP4. The 50% infectious dose (ID50) and lethal dose (LD50) of virus were estimated to be <1 and 10 TCID50 of MERS-CoV, respectively. Neutralizing antibody developed in the surviving mice from the ID50/LD50 determinations, and all were fully immune to challenge with 100 LD50 of MERS-CoV. The tissue distribution and histopathology in mice challenged with a potential working dose of 10 LD50 of MERS-CoV were subsequently evaluated. In contrast to the overwhelming infection seen in the mice challenged with 10(5) LD50 of MERS-CoV, we were able to recover infectious virus from these mice only infrequently, although quantitative reverse transcription-PCR (qRT-PCR) tests indicated early and persistent lung infection and delayed occurrence of brain infection. Persistent inflammatory infiltrates were seen in the lungs and brain stems at day 2 and day 6 after infection, respectively. While focal infiltrates were also noted in the liver, definite pathology was not seen in other tissues. Finally, using a receptor binding domain protein vaccine and a MERS-CoV fusion inhibitor, we demonstrated the value of this model for evaluating vaccines and antivirals against MERS. As outcomes of MERS-CoV infection in patients differ greatly, ranging from asymptomatic to overwhelming disease and death, having available both an infection model and a lethal model makes this transgenic mouse model relevant for advancing MERS research. Fully characterized animal models are essential for studying pathogenesis and for preclinical screening of vaccines and drugs against MERS-CoV infection and disease. When given a high dose of MERS-CoV, our transgenic mice expressing hCD26/DPP4 viral receptor uniformly succumbed to death within 6 days, making it difficult to evaluate host responses to infection and disease. We further characterized this model by determining both the ID50 and the LD50 of MERS-CoV in order to establish both an infection model and a lethal model for MERS and followed this by investigating the antibody responses and immunity of the mice that survived MERS-CoV infection. Using the estimated LD50 and ID50 data, we dissected the kinetics of viral tissue distribution and pathology in mice challenged with 10 LD50 of virus and utilized the model for preclinical evaluation of a vaccine and drug for treatment of MERS-CoV infection. This further-characterized transgenic mouse model will be useful for advancing MERS research. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Titration of biologically active amyloid–β seeds in a transgenic mouse model of Alzheimer's disease

PubMed Central

Morales, Rodrigo; Bravo-Alegria, Javiera; Duran-Aniotz, Claudia; Soto, Claudio

2015-01-01

Experimental evidence in animal models suggests that misfolded Amyloid-β (Aβ) spreads in disease following a prion-like mechanism. Several properties characteristics of infectious prions have been shown for the induction of Aβ aggregates. However, a detailed titration of Aβ misfolding transmissibility and estimation of the minimum concentration of biologically active Aβ seeds able to accelerate pathological changes has not yet been performed. In this study, brain extracts from old tg2576 animals were serially diluted and intra-cerebrally injected into young subjects from the same transgenic line. Animals were sacrificed several months after treatment and brain slices were analyzed for amyloid pathology. We observed that administration of misfolded Aβ was able to significantly accelerate amyloid deposition in young mice, even when the original sample was diluted a million times. The titration curve obtained in this experiment was compared to the natural Aβ load spontaneously accumulated by these mice overtime. Our findings suggest that administration of the largest dose of Aβ seeds led to an acceleration of pathology equivalent to over a year. These results show that active Aβ seeds present in the brain can seed amyloidosis in a titratable manner, similarly as observed for infectious prions. PMID:25879692

Thiamine deficiency induces oxidative stress and exacerbates the plaque pathology in Alzheimer’s mouse model

PubMed Central

Karuppagounder, Saravanan S.; Xu, Hui; Shi, Qingli; Chen, Lian H.; Pedrini, Steve; Pechman, David; Baker, Harriet; Beal, M. Flint; Gandy, Sam E.; Gibson, Gary E.

2009-01-01

Mitochondrial dysfunction, oxidative stress and reductions in thiamine-dependent enzymes have been implicated in multiple neurological disorders including Alzheimer's disease (AD). Experimental thiamine deficiency (TD) is an established model for reducing the activities of thiamine-dependent enzymes in brain. TD diminishes thiamine dependent enzymes throughout the brain, but produces a time-dependent selective neuronal loss, glial activation, inflammation, abnormalities in oxidative metabolism and clusters of degenerating neurites in only specific thalamic regions. The present studies tested how TD alters brain pathology in Tg19959 transgenic mice over expressing a double mutant form of the amyloid precursor protein (APP). TD exacerbated amyloid plaque pathology in transgenic mice and enlarged the area occupied by plaques in cortex, hippocampus and thalamus by 50%, 200% and 200%, respectively. TD increased Aβ1–42 levels by about three-fold, β-CTF (C99) levels by 33% and β-secretase (BACE1) protein levels by 43%. TD induced inflammation in areas of plaque formation. Thus, the induction of mild impairment of oxidative metabolism, oxidative stress and inflammation induced by TD alters metabolism of APP and/or Aβ and promotes accumulation of plaques independent of neuron loss or neuritic clusters. PMID:18406011

Prevention of pathology in mdx mice by expression of utrophin: analysis using an inducible transgenic expression system.

PubMed

Squire, S; Raymackers, J M; Vandebrouck, C; Potter, A; Tinsley, J; Fisher, R; Gillis, J M; Davies, K E

2002-12-15

Duchenne muscular dystrophy results from the absence of dystrophin, a cytoskeletal protein. Previously, we have shown in a transgenic mouse model of the disease (mdx) that high levels of expression of the dystrophin-related protein, utrophin can prevent pathology. We developed a new transgenic mouse model where muscle specific utrophin expression was conditioned by addition of tetracycline in water. Transgene expression was turned on at different time points: in utero, at birth, 10 and 30 days after birth. We obtained moderate levels of expression, variable from fibre to fibre (mosaicism) but sufficient to induce a correct localization of the dystro-sarcoglycan complex. Histology revealed a reduction of necrotic foci and of the percentage of centronucleated fibres, which remained still largely above the normal level. Isometric force was not improved but the resistance to eccentric contractions was significantly stronger. When utrophin expression was activated 30 days after birth, improvements were marginal, suggesting that the age at which utrophin therapy is initiated could be an important factor. Our results also provide an unexpected insight into the pathogenesis of the dystrophinopathies. We observed a complete normalization of the characteristics of the mechano-sensitive/voltage-independent Ca(2+) channels (occurrence, open probabilities and Ca(2+) currents), while the classical markers of dystrophy were still abnormal. These observations question the role of increased Ca(2+) channel activity in initiating the dystrophic process. The new model shows that utrophin therapy, initiated after birth, can be effective, but the extent of correction of the various symptoms of dystrophinopathy critically depends on the amount of utrophin expressed.

Deuterated polyunsaturated fatty acids reduce brain lipid peroxidation and hippocampal amyloid β-peptide levels, without discernable behavioral effects in an APP/PS1 mutant transgenic mouse model of Alzheimer's disease.

PubMed

Raefsky, Sophia M; Furman, Ran; Milne, Ginger; Pollock, Erik; Axelsen, Paul; Mattson, Mark P; Shchepinov, Mikhail S

2018-06-01

Alzheimer's disease (AD) involves progressive deposition of amyloid β-peptide (Aβ), synapse loss, and neuronal death, which occur in brain regions critical for learning and memory. Considerable evidence suggests that lipid peroxidation contributes to synaptic dysfunction and neuronal degeneration, both upstream and downstream of Aβ pathology. Recent findings suggest that lipid peroxidation can be inhibited by replacement of polyunsaturated fatty acids (PUFA) with isotope-reinforced (deuterated) PUFA (D-PUFA), and that D-PUFA can protect neurons in experimental models of Parkinson's disease. Here, we determined whether dietary D-PUFA would ameliorate Aβ pathology and/or cognitive deficits in a mouse model of AD (amyloid precursor protein/presenilin 1 double mutant transgenic mice). The D-PUFA diet did not ameliorate spatial learning and memory deficits in the AD mice. Compared to mice fed an hydrogenated-PUFA control diet, those fed D-PUFA for 5 months exhibited high levels of incorporation of deuterium into arachidonic acid and docosahexaenoic acid, and reduced concentrations of lipid peroxidation products (F2 isoprostanes and neuroprostanes), in the brain tissues. Concentrations of Aβ40 and Aβ38 in the hippocampus were significantly lower, with a trend to reduced concentrations of Aβ42, in mice fed D-PUFA compared to those fed hydrogenated-PUFA. We conclude that a D-PUFA diet reduces the brain tissue concentrations of both arachidonic acid and docosahexaenoic acid oxidation products, as well as the concentration of Aβs. Published by Elsevier Inc.

Pain, motor and gait assessment of murine osteoarthritis in a cruciate ligament transection model.

PubMed

Ruan, M Z C; Patel, R M; Dawson, B C; Jiang, M-M; Lee, B H L

2013-09-01

The major complaint of Osteoarthritis (OA) patients is pain. However, due to the nature of clinical studies and the limitation of animal studies, few studies have linked function impairment and behavioral changes in OA animal models to cartilage loss and histopathology. Our objective was to study surrogate markers of functional impairment in relation to cartilage loss and pathological changes in a post-traumatic mouse model of OA. We performed a battery of functional analyses in a mouse model of OA generated by cruciate ligament transection (CLT). The changes in functional analyses were linked to histological changes graded by OARSI standards, histological grading of synovitis, and volumetric changes of the articular cartilage and osteophytes quantified by phase contrast micro-computed tomography (μCT). OA generated by CLT led to decreased time on rotarod, delayed response on hotplate analysis, and altered gait starting from 4 weeks after surgery. Activity in open field analysis did not change at 4, 8, or 12 weeks after CLT. The magnitude of behavioral changes was directly correlated with higher OARSI histological scores of OA, synovitis in the knee joints, cartilage volume loss, and osteophyte formation. Our findings link functional analyses to histological grading, synovitis, comprehensive three-dimensional assessment of cartilage volume and osteophyte formation. This serves as a reference for a mouse model in predicting outcomes of OA treatment. Copyright © 2013 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.

Early-Onset Network Hyperexcitability in Presymptomatic Alzheimer’s Disease Transgenic Mice Is Suppressed by Passive Immunization with Anti-Human APP/Aβ Antibody and by mGluR5 Blockade

PubMed Central

Kazim, Syed F.; Chuang, Shih-Chieh; Zhao, Wangfa; Wong, Robert K. S.; Bianchi, Riccardo; Iqbal, Khalid

2017-01-01

Cortical and hippocampal network hyperexcitability appears to be an early event in Alzheimer’s disease (AD) pathogenesis, and may contribute to memory impairment. It remains unclear if network hyperexcitability precedes memory impairment in mouse models of AD and what are the underlying cellular mechanisms. We thus evaluated seizure susceptibility and hippocampal network hyperexcitability at ~3 weeks of age [prior to amyloid beta (Aβ) plaque deposition, neurofibrillary pathology, and cognitive impairment] in a triple transgenic mouse model of familial AD (3xTg-AD mouse) that harbors mutated human Aβ precursor protein (APP), tau and presenilin 1 (PS1) genes. Audiogenic seizures were elicited in a higher proportion of 3xTg-AD mice compared with wild type (WT) controls. Seizure susceptibility in 3xTg-AD mice was attenuated either by passive immunization with anti-human APP/Aβ antibody (6E10) or by blockade of metabotropic glutamate receptor 5 (mGluR5) with the selective antagonist, 2-methyl-6-(phenylethynyl)pyridine hydrochloride (MPEP). In in vitro hippocampal slices, suppression of synaptic inhibition with the GABAA receptor antagonist, bicuculline, induced prolonged epileptiform (>1.5 s in duration) ictal-like discharges in the CA3 neuronal network in the majority of the slices from 3xTg-AD mice. In contrast, only short epileptiform (<1.5 s in duration) interictal-like discharges were observed following bicuculline application in the CA3 region of WT slices. The ictal-like activity in CA3 region of the hippocampus was significantly reduced in the 6E10-immunized compared to the saline-treated 3xTg-AD mice. MPEP acutely suppressed the ictal-like discharges in 3xTg-AD slices. Remarkably, epileptiform discharge duration positively correlated with intraneuronal human (transgenic) APP/Aβ expression in the CA3 region of the hippocampus. Our data suggest that in a mouse model of familial AD, hypersynchronous network activity underlying seizure susceptibility precedes Aβ plaque pathology and memory impairment. This early-onset network hyperexcitability can be suppressed by passive immunization with an anti-human APP/Aβ antibody and by mGluR5 blockade in 3xTg-AD mice. PMID:28392767

Creation of miniature pig model of human Waardenburg syndrome type 2A by ENU mutagenesis.

PubMed

Hai, Tang; Guo, Weiwei; Yao, Jing; Cao, Chunwei; Luo, Ailing; Qi, Meng; Wang, Xianlong; Wang, Xiao; Huang, Jiaojiao; Zhang, Ying; Zhang, Hongyong; Wang, Dayu; Shang, Haitao; Hong, Qianlong; Zhang, Rui; Jia, Qitao; Zheng, Qiantao; Qin, Guosong; Li, Yongshun; Zhang, Tao; Jin, Weiwu; Chen, Zheng-Yi; Wang, Hongmei; Zhou, Qi; Meng, Anming; Wei, Hong; Yang, Shiming; Zhao, Jianguo

2017-11-01

Human Waardenburg syndrome 2A (WS2A) is a dominant hearing loss (HL) syndrome caused by mutations in the microphthalmia-associated transcription factor (MITF) gene. In mouse models with MITF mutations, WS2A is transmitted in a recessive pattern, which limits the study of hearing loss (HL) pathology. In the current study, we performed ENU (ethylnitrosourea) mutagenesis that resulted in substituting a conserved lysine with a serine (p. L247S) in the DNA-binding domain of the MITF gene to generate a novel miniature pig model of WS2A. The heterozygous mutant pig (MITF +/L247S ) exhibits a dominant form of profound HL and hypopigmentation in skin, hair, and iris, accompanied by degeneration of stria vascularis (SV), fused hair cells, and the absence of endocochlear potential, which indicate the pathology of human WS2A. Besides hypopigmentation and bilateral HL, the homozygous mutant pig (MITF L247S/L247S ) and CRISPR/Cas9-mediated MITF bi-allelic knockout pigs both exhibited anophthalmia. Three WS2 patients carrying MITF mutations adjacent to the corresponding region were also identified. The pig models resemble the clinical symptom and molecular pathology of human WS2A patients perfectly, which will provide new clues for better understanding the etiology and development of novel treatment strategies for human HL.

Transcriptional regulation of N-acetylaspartate metabolism in the 5xFAD model of Alzheimer's disease: evidence for neuron-glia communication during energetic crisis.

PubMed

Zaroff, Samantha; Leone, Paola; Markov, Vladimir; Francis, Jeremy S

2015-03-01

N-acetylaspartate (NAA) provides a non-invasive clinical index of neuronal metabolic integrity across the entire neurodegenerative spectrum. While NAA function is not comprehensively defined, reductions in the brain are associated with compromised mitochondrial metabolism and are tightly linked to ATP. We have undertaken an analysis of abnormalities in NAA during early stage pathology in the 5xFAD mouse model of familial Alzheimer's disease and show here that dysregulated expression of the gene encoding for the rate-limiting NAA synthetic enzyme (Nat8L) is associated with deficits in mitochondrial oxidative phosphorylation in this model system. Downreguation of Nat8L is particularly pronounced in the 5xFAD hippocampus, and is preceded by a significant upregulation of oligodendrocytic aspartoacylase (aspa), which encodes for the sole known NAA-catabolizing enzyme in the brain. Reductions in 5xFAD NAA and Nat8L cannot be accounted for by discrepancies in either neuron content or activity of the substrate-providing malate-aspartate shuttle, thereby implicating transcriptional regulation in a coordinated response to pathological energetic crisis. A central role for ASPA in this response is supported by a parallel developmental analysis showing highly significant increases in Nat8L expression in an ASPA-null mouse model during a period of early postnatal development normally punctuated by the transcriptional upregulation of aspa. These results provide preliminary evidence of a signaling mechanism in Alzheimer's disease that involves cross talk between neurons and oligodendrocytes, and suggest that ASPA acts to negatively regulate Nat8L expression. This mechanism is proposed to be a fundamental means by which the brain conserves available substrate during energy crises. Copyright © 2015 Elsevier Inc. All rights reserved.

IGF-1R Regulates the Extracellular Level of Active MMP-2, Pathological Neovascularization, and Functionality in Retinas of OIR Mouse Model.

PubMed

Lorenc, Valeria E; Subirada Caldarone, Paula V; Paz, María C; Ferrer, Darío G; Luna, José D; Chiabrando, Gustavo A; Sánchez, María C

2018-02-01

In ischemic proliferative diseases such as retinopathies, persistent hypoxia leads to the release of numerous neovascular factors that participate in the formation of abnormal vessels and eventually cause blindness. The upregulation and activation of metalloproteinases (MMP-2 and MMP-9) represent a final common pathway in this process. Although many regulators of the neovascular process have been identified, the complete role of the insulin-like growth factor 1 (IGF-1) and its receptor (IGF-1R) appears to be significantly more complex. In this study, we used an oxygen-induced retinopathy (OIR) mouse model as well as an in vitro model of hypoxia to study the role of MMP-2 derived from Müller glial cells (MGCs) and its relation with the IGF-1/IGF-1R system. We demonstrated that MMP-2 protein expression increased in P17 OIR mice, which coincided with the active phase of the neovascular process. Also, glutamine synthetase (GS)-positive cells were also positive for MMP-2, whereas IGF-1R was expressed by GFAP-positive cells, indicating that both proteins were expressed in MGCs. In addition, in the OIR model a single intravitreal injection of the IGF-1R blocking antibody (αIR3) administered at P12 effectively prevented pathologic neovascularization, accelerated physiological revascularization, and improved retinal functionality at P17. Finally, in MGC supernatants, the blocking antibody abolished the IGF-1 effect on active MMP-2 under normoxic and hypoxic conditions without affecting the extracellular levels of pro-MMP-2. These results demonstrate, for the first time, that the IGF-1/IGF-1R system regulates active MMP-2 levels in MGCs, thus contributing to MEC remodeling during the retinal neovascular process.

The artificial gene Jazz, a transcriptional regulator of utrophin, corrects the dystrophic pathology in mdx mice.

PubMed

Di Certo, Maria Grazia; Corbi, Nicoletta; Strimpakos, Georgios; Onori, Annalisa; Luvisetto, Siro; Severini, Cinzia; Guglielmotti, Angelo; Batassa, Enrico Maria; Pisani, Cinzia; Floridi, Aristide; Benassi, Barbara; Fanciulli, Maurizio; Magrelli, Armando; Mattei, Elisabetta; Passananti, Claudio

2010-03-01

The absence of the cytoskeletal protein dystrophin results in Duchenne muscular dystrophy (DMD). The utrophin protein is the best candidate for dystrophin replacement in DMD patients. To obtain therapeutic levels of utrophin expression in dystrophic muscle, we developed an alternative strategy based on the use of artificial zinc finger transcription factors (ZF ATFs). The ZF ATF 'Jazz' was recently engineered and tested in vivo by generating a transgenic mouse specifically expressing Jazz at the muscular level. To validate the ZF ATF technology for DMD treatment we generated a second mouse model by crossing Jazz-transgenic mice with dystrophin-deficient mdx mice. Here, we show that the artificial Jazz protein restores sarcolemmal integrity and prevents the development of the dystrophic disease in mdx mice. This exclusive animal model establishes the notion that utrophin-based therapy for DMD can be efficiently developed using ZF ATF technology and candidates Jazz as a novel therapeutic molecule for DMD therapy.

Docosahexaenoic acid protects from dendritic pathology in an Alzheimer's disease mouse model.

PubMed

Calon, Frédéric; Lim, Giselle P; Yang, Fusheng; Morihara, Takashi; Teter, Bruce; Ubeda, Oliver; Rostaing, Phillippe; Triller, Antoine; Salem, Norman; Ashe, Karen H; Frautschy, Sally A; Cole, Greg M

2004-09-02

Learning and memory depend on dendritic spine actin assembly and docosahexaenoic acid (DHA), an essential n-3 (omega-3) polyunsaturated fatty acid (PFA). High DHA consumption is associated with reduced Alzheimer's disease (AD) risk, yet mechanisms and therapeutic potential remain elusive. Here, we report that reduction of dietary n-3 PFA in an AD mouse model resulted in 80%-90% losses of the p85alpha subunit of phosphatidylinositol 3-kinase and the postsynaptic actin-regulating protein drebrin, as in AD brain. The loss of postsynaptic proteins was associated with increased oxidation, without concomitant neuron or presynaptic protein loss. n-3 PFA depletion increased caspase-cleaved actin, which was localized in dendrites ultrastructurally. Treatment of n-3 PFA-restricted mice with DHA protected against these effects and behavioral deficits and increased antiapoptotic BAD phosphorylation. Since n-3 PFAs are essential for p85-mediated CNS insulin signaling and selective protection of postsynaptic proteins, these findings have implications for neurodegenerative diseases where synaptic loss is critical, especially AD.

Hyperactivity with Agitative-Like Behavior in a Mouse Tauopathy Model.

PubMed

Jul, Pia; Volbracht, Christiane; de Jong, Inge E M; Helboe, Lone; Elvang, Anders Brandt; Pedersen, Jan Torleif

2016-01-01

Tauopathies, such as Alzheimer's disease (AD) and frontotemporal dementia (FTD), are characterized by formation of neurofibrillary tangles consisting of hyperphosphorylated tau. In addition to memory loss, patients experience behavioral symptoms such as agitation, aggression, depression, and insomnia. We explored the behavioral phenotype of a mouse model (rTg4510) carrying the human tau P301L mutation found in a familial form of FTD. We tested these mice in locomotor activity assays as well as in the Morris water maze to access spatial memory. In addition to cognitive impairments, rTg4510 mice exhibited a hyperactivity phenotype which correlated with progression of tau pathology and was dependent on P301L tau transgene expression. The hyperactive phenotype was characterized by significantly increased locomotor activity in a novel and in a simulated home cage environment together with a disturbed day/night cycle. The P301L-tau-dependent hyperactivity and agitative-like phenotype suggests that these mice may form a correlate to some of the behavioral disturbances observed in advanced AD and FTD.

Progressive dopaminergic cell loss with unilateral-to-bilateral progression in a genetic model of Parkinson disease

PubMed Central

Rousseaux, Maxime W. C.; Marcogliese, Paul C.; Qu, Dianbo; Hewitt, Sarah J.; Seang, Sarah; Kim, Raymond H.; Slack, Ruth S.; Schlossmacher, Michael G.; Lagace, Diane C.; Mak, Tak W.; Park, David S.

2012-01-01

DJ-1 mutations cause autosomal recessive early-onset Parkinson disease (PD). We report a model of PD pathology: the DJ1-C57 mouse. A subset of DJ-1–nullizygous mice, when fully backcrossed to a C57BL/6J background, display dramatic early-onset unilateral loss of dopaminergic (DA) neurons in their substantia nigra pars compacta, progressing to bilateral degeneration of the nigrostriatal axis with aging. In addition, these mice exhibit age-dependent bilateral degeneration at the locus ceruleus nucleus and display mild motor behavior deficits at aged time points. These findings effectively recapitulate the early stages of PD. Therefore, the DJ1-C57 mouse provides a tool to study the preclinical aspects of neurodegeneration. Importantly, by exome sequencing, we identify candidate modifying genes that segregate with the phenotype, providing potentially critical clues into how certain genes may influence the penetrance of DJ-1–related degeneration in mice. PMID:23019375

Reducing VEGF-B Signaling Ameliorates Renal Lipotoxicity and Protects against Diabetic Kidney Disease.

PubMed

Falkevall, Annelie; Mehlem, Annika; Palombo, Isolde; Heller Sahlgren, Benjamin; Ebarasi, Lwaki; He, Liqun; Ytterberg, A Jimmy; Olauson, Hannes; Axelsson, Jonas; Sundelin, Birgitta; Patrakka, Jaakko; Scotney, Pierre; Nash, Andrew; Eriksson, Ulf

2017-03-07

Diabetic kidney disease (DKD) is the most common cause of severe renal disease, and few treatment options are available today that prevent the progressive loss of renal function. DKD is characterized by altered glomerular filtration and proteinuria. A common observation in DKD is the presence of renal steatosis, but the mechanism(s) underlying this observation and to what extent they contribute to disease progression are unknown. Vascular endothelial growth factor B (VEGF-B) controls muscle lipid accumulation through regulation of endothelial fatty acid transport. Here, we demonstrate in experimental mouse models of DKD that renal VEGF-B expression correlates with the severity of disease. Inhibiting VEGF-B signaling in DKD mouse models reduces renal lipotoxicity, re-sensitizes podocytes to insulin signaling, inhibits the development of DKD-associated pathologies, and prevents renal dysfunction. Further, we show that elevated VEGF-B levels are found in patients with DKD, suggesting that VEGF-B antagonism represents a novel approach to treat DKD. Copyright © 2017 Elsevier Inc. All rights reserved.

Approach to Assessing Determinants of Glucose Homeostasis in the Conscious Mouse

PubMed Central

Hughey, Curtis C.; Wasserman, David H.; Lee-Young, Robert S.; Lantier, Louise

2014-01-01

Obesity and type 2 diabetes lessen the quality of life of those afflicted and place considerable burden on the healthcare system. Furthermore, the detrimental impact of these pathologies is expected to persist or even worsen. Diabetes is characterized by impaired insulin action and glucose homeostasis. This has led to a rapid increase in the number of mouse models of metabolic disease being used in the basic sciences to assist in facilitating a greater understanding of the metabolic dysregulation associated with obesity and diabetes, the identification of therapeutic targets, and the discovery of effective treatments. This review briefly describes the most frequently utilized models of metabolic disease. A presentation of standard methods and technologies on the horizon for assessing metabolic phenotypes in mice, with particular emphasis on glucose handling and energy balance, is provided. The article also addresses issues related to study design, selection and execution of metabolic tests of glucose metabolism, the presentation of data, and interpretation of results. PMID:25074441

GM-CSF primes cardiac inflammation in a mouse model of Kawasaki disease

PubMed Central

McKenzie, Brent S.

2016-01-01

Kawasaki disease (KD) is the leading cause of pediatric heart disease in developed countries. KD patients develop cardiac inflammation, characterized by an early infiltrate of neutrophils and monocytes that precipitates coronary arteritis. Although the early inflammatory processes are linked to cardiac pathology, the factors that regulate cardiac inflammation and immune cell recruitment to the heart remain obscure. In this study, using a mouse model of KD (induced by a cell wall Candida albicans water-soluble fraction [CAWS]), we identify an essential role for granulocyte/macrophage colony-stimulating factor (GM-CSF) in orchestrating these events. GM-CSF is rapidly produced by cardiac fibroblasts after CAWS challenge, precipitating cardiac inflammation. Mechanistically, GM-CSF acts upon the local macrophage compartment, driving the expression of inflammatory cytokines and chemokines, whereas therapeutically, GM-CSF blockade markedly reduces cardiac disease. Our findings describe a novel role for GM-CSF as an essential initiating cytokine in cardiac inflammation and implicate GM-CSF as a potential target for therapeutic intervention in KD. PMID:27595596

Development of a functional thyroid model based on an organoid culture system.

PubMed

Saito, Yoshiyuki; Onishi, Nobuyuki; Takami, Hiroshi; Seishima, Ryo; Inoue, Hiroyoshi; Hirata, Yuki; Kameyama, Kaori; Tsuchihashi, Kenji; Sugihara, Eiji; Uchino, Shinya; Ito, Koichi; Kawakubo, Hirofumi; Takeuchi, Hiroya; Kitagawa, Yuko; Saya, Hideyuki; Nagano, Osamu

2018-03-04

The low turnover rate of thyroid follicular cells and the lack of a long-term thyroid cell culture system have hampered studies of thyroid carcinogenesis. We have now established a thyroid organoid culture system that supports thyroid cell proliferation in vitro. The established mouse thyroid organoids performed thyroid functions including thyroglobulin synthesis, iodide uptake, and the production and release of thyroid hormone. Furthermore, transplantation of the organoids into recipient mice resulted in the formation of normal thyroid-like tissue capable of iodide uptake and thyroglobulin production in vivo. Finally, forced expression of oncogenic NRAS (NRAS Q61R ) in thyroid organoids established from p53 knockout mice and transplantation of the manipulated organoids into mouse recipients generated a model of poorly differentiated thyroid cancer. Our findings suggest that this newly developed thyroid organoid culture system is a potential research tool for the study of thyroid physiology and pathology including thyroid cancer. Copyright © 2018 Elsevier Inc. All rights reserved.

Inhibition of delta-secretase improves cognitive functions in mouse models of Alzheimer's disease

PubMed Central

Zhang, Zhentao; Obianyo, Obiamaka; Dall, Elfriede; Du, Yuhong; Fu, Haian; Liu, Xia; Kang, Seong Su; Song, Mingke; Yu, Shan-Ping; Cabrele, Chiara; Schubert, Mario; Li, Xiaoguang; Wang, Jian-Zhi; Brandstetter, Hans; Ye, Keqiang

2017-01-01

δ-secretase, also known as asparagine endopeptidase (AEP) or legumain, is a lysosomal cysteine protease that cleaves both amyloid precursor protein (APP) and tau, mediating the amyloid-β and tau pathology in Alzheimer's disease (AD). Here we report the therapeutic effect of an orally bioactive and brain permeable δ-secretase inhibitor in mouse models of AD. We performed a high-throughput screen and identified a non-toxic and selective δ-secretase inhibitor, termed compound 11, that specifically blocks δ-secretase but not other related cysteine proteases. Co-crystal structure analysis revealed a dual active site-directed and allosteric inhibition mode of this compound class. Chronic treatment of tau P301S and 5XFAD transgenic mice with this inhibitor reduces tau and APP cleavage, ameliorates synapse loss and augments long-term potentiation, resulting in protection of memory. Therefore, these findings demonstrate that this δ-secretase inhibitor may be an effective clinical therapeutic agent towards AD. PMID:28345579

Antisense oligonucleotide-mediated correction of transcriptional dysregulation is correlated with behavioral benefits in the YAC128 mouse model of Huntington's disease.

PubMed

Stanek, Lisa M; Yang, Wendy; Angus, Stuart; Sardi, Pablo S; Hayden, Michael R; Hung, Gene H; Bennett, C Frank; Cheng, Seng H; Shihabuddin, Lamya S

2013-01-01

Huntington's disease (HD) is a neurological disorder caused by mutations in the huntingtin (HTT) gene, the product of which leads to selective and progressive neuronal cell death in the striatum and cortex. Transcriptional dysregulation has emerged as a core pathologic feature in the CNS of human and animal models of HD. It is still unclear whether perturbations in gene expression are a consequence of the disease or importantly, contribute to the pathogenesis of HD. To examine if transcriptional dysregulation can be ameliorated with antisense oligonucleotides that reduce levels of mutant Htt and provide therapeutic benefit in the YAC128 mouse model of HD. Quantitative real-time PCR analysis was used to evaluate dysregulation of a subset of striatal genes in the YAC128 mouse model. Transcripts were then evaluated following ICV delivery of antisense oligonucleotides (ASO). Rota rod and Porsolt swim tests were used to evaluate phenotypic deficits in these mice following ASO treatment. Transcriptional dysregulation was detected in the YAC128 mouse model and appears to progress with age. ICV delivery of ASOs directed against mutant Htt resulted in reduction in mutant Htt levels and amelioration in behavioral deficits in the YAC128 mouse model. These improvements were correlated with improvements in the levels of several dysregulated striatal transcripts. The role of transcriptional dysregulation in the pathogenesis of Huntington's disease is not well understood, however, a wealth of evidence now strongly suggests that changes in transcriptional signatures are a prominent feature in the brains of both HD patients and animal models of the disease. Our study is the first to show that a therapeutic agent capable of improving an HD disease phenotype is concomitantly correlated with normalization of a subset of dysregulated striatal transcripts. Our data suggests that correction of these disease-altered transcripts may underlie, at least in part, the therapeutic efficacy shown associated with ASO-mediated correction of HD phenotypes and may provide a novel set of early biomarkers for evaluating future therapeutic concepts for HD.

Lentiviral-mediated gene therapy results in sustained expression of β-glucuronidase for up to 12 months in the gus(mps/mps) and up to 18 months in the gus(tm(L175F)Sly) mouse models of mucopolysaccharidosis type VII.

PubMed

Derrick-Roberts, Ainslie L K; Pyragius, Carmen E; Kaidonis, Xenia M; Jackson, Matilda R; Anson, Donald S; Byers, Sharon

2014-09-01

A number of mucopolysaccharidosis type VII (MPS VII) mouse models with different levels of residual enzyme activity have been created replicating the range of clinical phenotypes observed in human MPS VII patients. In this study, a lentivirus encoding murine β-glucuronidase was administered intravenously at birth to both the severe (Gus(mps/mps) strain) and attenuated (Gus(tm(L175F)Sly) strain) mouse models of MPS VII. Circulating enzyme levels were normalized in the Gus(mps/mps) mice and were 3.5-fold higher than normal in the Gus(tm(L175F)Sly) mouse 12 and 18 months after administration. Tissue β-glucuronidase activity increased over untreated levels in all tissues evaluated in both strains at 12 months, and the elevated level was maintained in Gus(tm(L175F)Sly) tissues at 18 months. These elevated enzyme levels reduced glycosaminoglycan storage in the liver, spleen, kidney, and heart in both models. Bone mineral volume decreased toward normal in both models after 12 months of therapy and after 18 months in the Gus(tm(L175F)Sly) mouse. Open-field exploration was improved in 18-month-old treated Gus(tm(L175F)Sly) mice, while spatial learning improved in both 12- and 18-month-old treated Gus(tm(L175F)Sly) mice. Overall, neonatal administration of lentiviral gene therapy resulted in sustained enzyme expression for up to 18 months in murine models of MPS VII. Significant improvements in biochemistry and enzymology as well as functional improvement of bone and behavior deficits in the Gus(tm(L175F)Sly) model were observed. Therapy significantly increased the lifespan of Gus(mps/mps) mice, with 12 months being the longest reported lentiviral treatment for this strain. It is important to assess the long-term outcome on enzyme levels and effect on pathology for lentiviral gene therapy to be a potential therapy for MPS patients.

Antiangiogenic effect of betaine on pathologic retinal neovascularization via suppression of reactive oxygen species mediated vascular endothelial growth factor signaling.

PubMed

Park, Sung Wook; Jun, Hyoung Oh; Kwon, Euna; Yun, Jun-Won; Kim, Jin Hyoung; Park, Young-Jun; Kang, Byeong-Cheol; Kim, Jeong Hun

2017-03-01

Reactive oxygen species (ROS) as well as vascular endothelial growth factor (VEGF) play important roles in pathologic retinal neovascularization. We investigated whether betaine inhibits pathologic retinal neovascularization in a mouse model of oxygen induced retinopathy (OIR). Betaine was intravitreally injected in OIR mice at postnatal day (P) 14. At P17, the neovascular tufts area in OIR retina was analyzed. Intravitreal injection of betaine (200μM) effectively reduced the neovascular tufts area in OIR retina (68.0±6.7% of the control eyes, P<0.05). Even in a high concentration (2mM), betaine never induced any retinal toxicity or cytotoxicity. Betaine significantly inhibited VEGF-induced proliferation, migration, and tube formation in human retinal microvascular endothelial cells (HRMECs). Betaine suppressed VEGF-induced VEGFR-2, Akt and ERK phosphorylation in HRMECs. In human brain astrocytes, betaine reduced tBH-induced ROS production, and subsequently attenuated tBH-induced VEGFA mRNA transcription via suppression of ROS. Our data suggest that betaine has an anti-angiogenic effect on pathologic retinal neovascularization via suppression of ROS mediated VEGF signaling. Betaine could be a potent anti-angiogenic agent to treat pathologic retinal neovascularization. Copyright © 2016 Elsevier Inc. All rights reserved.

Characterization of Barmah Forest virus pathogenesis in a mouse model.

PubMed

Herrero, Lara J; Lidbury, Brett A; Bettadapura, Jayaram; Jian, Peng; Herring, Belinda L; Hey-Cunningham, William J; Sheng, Kuo-Ching; Zakhary, Andrew; Mahalingam, Suresh

2014-10-01

Alphaviruses including Barmah Forest virus (BFV) and Ross River virus (RRV) cause arthritis, arthralgia and myalgia in humans. The rheumatic symptoms in human BFV infection are very similar to those of RRV. Although RRV disease has been studied extensively, little is known about the pathogenesis of BFV infection. We sought to establish a mouse model for BFV to facilitate our understanding of BFV infectivity, tropism and pathogenesis, and to identify key pathological and immunological mechanisms of BFV infection that may distinguish between infections with BFV and RRV. Here, to the best of our knowledge, we report the first study assessing the virulence and replication of several BFV isolates in a mouse model. We infected newborn Swiss outbred mice with BFV and established that the BFV2193 prototype was the most virulent strain. BFV2193 infection resulted in the highest mortality among all BFV variant isolates, comparable to that of RRV. In comparison with RRV, C57BL/6 mice infected with BFV showed delayed onset, moderate disease scores and early recovery of the disease. BFV replicated poorly in muscle and did not cause the severe myositis seen in RRV-infected mice. The mRNAs for the inflammatory mediators TNF-α, IL-6, CCL2 and arginase-1 were highly upregulated in RRV- but not BFV-infected muscle. To our knowledge, this is the first report of a mouse model of BFV infection, which we have used to demonstrate differences between BFV and RRV infections and to further understand disease pathogenesis. With an increasing number of BFV cases occurring annually, a better understanding of the disease mechanisms is essential for future therapeutic development. © 2014 The Authors.

Vitamin K supplementation increases vitamin K tissue levels but fails to counteract ectopic calcification in a mouse model for pseudoxanthoma elasticum.

PubMed

Gorgels, Theo G M F; Waarsing, Jan H; Herfs, Marjolein; Versteeg, Daniëlle; Schoensiegel, Frank; Sato, Toshiro; Schlingemann, Reinier O; Ivandic, Boris; Vermeer, Cees; Schurgers, Leon J; Bergen, Arthur A B

2011-11-01

Pseudoxanthoma elasticum (PXE) is an autosomal recessive disorder in which calcification of connective tissue leads to pathology in skin, eye and blood vessels. PXE is caused by mutations in ABCC6. High expression of this transporter in the basolateral hepatocyte membrane suggests that it secretes an as-yet elusive factor into the circulation which prevents ectopic calcification. Utilizing our Abcc6 (-/-) mouse model for PXE, we tested the hypothesis that this factor is vitamin K (precursor) (Borst et al. 2008, Cell Cycle). For 3 months, Abcc6 (-/-) and wild-type mice were put on diets containing either the minimum dose of vitamin K required for normal blood coagulation or a dose that was 100 times higher. Vitamin K was supplied as menaquinone-7 (MK-7). Ectopic calcification was monitored in vivo by monthly micro-CT scans of the snout, as the PXE mouse model develops a characteristic connective tissue mineralization at the base of the whiskers. In addition, calcification of kidney arteries was measured by histology. Results show that supplemental MK-7 had no effect on ectopic calcification in Abcc6 ( -/- ) mice. MK-7 supplementation increased vitamin K levels (in skin, heart and brain) in wild-type and in Abcc6 (-/-) mice. Vitamin K tissue levels did not depend on Abcc6 genotype. In conclusion, dietary MK-7 supplementation increased vitamin K tissue levels in the PXE mouse model but failed to counteract ectopic calcification. Hence, we obtained no support for the hypothesis that Abcc6 transports vitamin K and that PXE can be cured by increasing tissue levels of vitamin K.

Cholinergic neurodegeneration in an Alzheimer mouse model overexpressing amyloid-precursor protein with the Swedish-Dutch-Iowa mutations.

PubMed

Foidl, Bettina Maria; Do-Dinh, Patricia; Hutter-Schmid, Bianca; Bliem, Harald R; Humpel, Christian

2016-12-01

Alzheimer's disease (AD) is a chronic neurodegenerative disorder that is mainly characterized by beta-amyloid (Aβ) plaque deposition, Tau pathology and dysfunction of the cholinergic system causing memory impairment. The aim of the present study was to examine (1) anxiety and cognition, (2) Aβ plaque deposition and (3) degeneration of cholinergic neurons in the nucleus basalis of Meynert (nbM) and cortical cholinergic innervation in an Alzheimer mouse model (APP_SweDI; overexpressing amyloid precursor protein (APP) with the Swedish K670N/M671L, Dutch E693Q, and Iowa D694N mutations). Our results show that 12-month-old APP_SweDI mice were more anxious and had more memory impairment. A large number of Aβ plaques were already visible at the age of 6 months and increased with age. A significant decrease in cholinergic neurons was seen in the transgenic mouse model in comparison to the wild-type mice, identified by immunohistochemistry against choline acetyltransferase (ChAT) and p75 neurotrophin receptor as well as by in situ hybridization. Moreover, a significant decrease in cortical cholinergic fiber density was found in the transgenic mice as compared to the wild-type. In the cerebral cortex of APP_SweDI mice, swollen cholinergic varicosities were seen in the vicinity of Aβ plaques. In conclusion, the present study shows that in an AD mouse model (APP_SweDI mice) a high Aβ plaque load in the cortex causes damage to cholinergic axons in the cortex, followed by subsequent retrograde-induced cell death of cholinergic neurons and some forms of compensatory processes. This degeneration was accompanied by enhanced anxiety and impaired cognition. Copyright © 2016 Elsevier Inc. All rights reserved.

Prolonged running, not fluoxetine treatment, increases neurogenesis, but does not alter neuropathology, in the 3xTg mouse model of Alzheimer's disease.

PubMed

Marlatt, Michael W; Potter, Michelle C; Bayer, Thomas A; van Praag, Henriette; Lucassen, Paul J

2013-01-01

Reductions in adult neurogenesis have been documented in the original 3xTg mouse model of Alzheimer's disease (AD), notably occurring at the same age when spatial memory deficits and amyloid plaque pathology appeared. As this suggested reduced neurogenesis was associated with behavioral deficits, we tested whether activity and pharmacological stimulation could prevent memory deficits and modify neurogenesis and/or neuropathology in the 3xTg model backcrossed to the C57Bl/6 strain. We chronically administered the antidepressant fluoxetine to one group of mice, allowed access to a running wheel in another, and combined both treatments in a third cohort. All treatments lasted for 11 months. The female 3xTg mice failed to exhibit any deficits in spatial learning and memory as measured in the Morris water maze, indicating that when backcrossed to the C57Bl/6 strain, the 3xTg mice lost the behavioral phenotype that was present in the original 3xTg mouse maintained on a hybrid background. Despite this, the backcrossed 3xTg mice expressed prominent intraneuronal amyloid beta (Aβ) levels in the cortex and amygdala, with lower levels in the CA1 area of the hippocampus. In the combined cohort, fluoxetine treatment interfered with exercise and reduced the total distance run. The extent of Aβ neuropathology, the tau accumulations, or BDNF levels, were not altered by prolonged exercise. Thus, neuropathology was present but not paralleled by spatial memory deficits in the backcrossed 3xTg mouse model of AD. Prolonged exercise for 11 months did improve the long-term survival of newborn neurons generated during middle-age, whereas fluoxetine had no effect. We further review and discuss the relevant literature in this respect.

AAV-PHP.B-Mediated Global-Scale Expression in the Mouse Nervous System Enables GBA1 Gene Therapy for Wide Protection from Synucleinopathy.

PubMed

Morabito, Giuseppe; Giannelli, Serena G; Ordazzo, Gabriele; Bido, Simone; Castoldi, Valerio; Indrigo, Marzia; Cabassi, Tommaso; Cattaneo, Stefano; Luoni, Mirko; Cancellieri, Cinzia; Sessa, Alessandro; Bacigaluppi, Marco; Taverna, Stefano; Leocani, Letizia; Lanciego, José L; Broccoli, Vania

2017-12-06

The lack of technology for direct global-scale targeting of the adult mouse nervous system has hindered research on brain processing and dysfunctions. Currently, gene transfer is normally achieved by intraparenchymal viral injections, but these injections target a restricted brain area. Herein, we demonstrated that intravenous delivery of adeno-associated virus (AAV)-PHP.B viral particles permeated and diffused throughout the neural parenchyma, targeting both the central and the peripheral nervous system in a global pattern. We then established multiple procedures of viral transduction to control gene expression or inactivate gene function exclusively in the adult nervous system and assessed the underlying behavioral effects. Building on these results, we established an effective gene therapy strategy to counteract the widespread accumulation of α-synuclein deposits throughout the forebrain in a mouse model of synucleinopathy. Transduction of A53T-SCNA transgenic mice with AAV-PHP.B-GBA1 restored physiological levels of the enzyme, reduced α-synuclein pathology, and produced significant behavioral recovery. Finally, we provided evidence that AAV-PHP.B brain penetration does not lead to evident dysfunctions in blood-brain barrier integrity or permeability. Altogether, the AAV-PHP.B viral platform enables non-invasive, widespread, and long-lasting global neural expression of therapeutic genes, such as GBA1, providing an invaluable approach to treat neurodegenerative diseases with diffuse brain pathology such as synucleinopathies. Copyright © 2017 The American Society of Gene and Cell Therapy. Published by Elsevier Inc. All rights reserved.

Human Leukocyte Antigen Class II Transgenic Mouse Model Unmasks the Significant Extrahepatic Pathology in Toxic Shock Syndrome

PubMed Central

Tilahun, Ashenafi Y.; Marietta, Eric V.; Wu, Tsung-Teh; Patel, Robin; David, Chella S.; Rajagopalan, Govindarajan

2011-01-01

Among the exotoxins produced by Staphylococcus aureus and Streptococcus pyogenes, the superantigens (SAgs) are the most potent T-cell activators known to date. SAgs are implicated in several serious diseases including toxic shock syndrome (TSS), Kawasaki disease, and sepsis. However, the immunopathogenesis of TSS and other diseases involving SAgs are still not completely understood. The commonly used conventional laboratory mouse strains do not respond robustly to SAgs in vivo. Therefore, they must be artificially rendered susceptible to TSS by using sensitizing agents such as d-galactosamine (d-galN), which skews the disease exclusively to the liver and, hence, is not representative of the disease in humans. SAg-induced TSS was characterized using transgenic mice expressing HLA class II molecules that are extremely susceptible to TSS without d-galN. HLA-DR3 transgenic mice recapitulated TSS in humans with extensive multiple-organ inflammation affecting the lung, liver, kidneys, heart, and small intestines. Heavy infiltration with T lymphocytes (both CD4+ and CD8+), neutrophils, and macrophages was noted. In particular, the pathologic changes in the small intestines were extensive and accompanied by significantly altered absorptive functions of the enterocytes. In contrast to massive liver failure alone in the d-galN sensitization model of TSS, findings of the present study suggest that gut dysfunction might be a key pathogenic event that leads to high morbidity and mortality in humans with TSS. PMID:21641398

Fragile X Mental Retardation Protein (FMRP) controls diacylglycerol kinase activity in neurons.

PubMed

Tabet, Ricardos; Moutin, Enora; Becker, Jérôme A J; Heintz, Dimitri; Fouillen, Laetitia; Flatter, Eric; Krężel, Wojciech; Alunni, Violaine; Koebel, Pascale; Dembélé, Doulaye; Tassone, Flora; Bardoni, Barbara; Mandel, Jean-Louis; Vitale, Nicolas; Muller, Dominique; Le Merrer, Julie; Moine, Hervé

2016-06-28

Fragile X syndrome (FXS) is caused by the absence of the Fragile X Mental Retardation Protein (FMRP) in neurons. In the mouse, the lack of FMRP is associated with an excessive translation of hundreds of neuronal proteins, notably including postsynaptic proteins. This local protein synthesis deregulation is proposed to underlie the observed defects of glutamatergic synapse maturation and function and to affect preferentially the hundreds of mRNA species that were reported to bind to FMRP. How FMRP impacts synaptic protein translation and which mRNAs are most important for the pathology remain unclear. Here we show by cross-linking immunoprecipitation in cortical neurons that FMRP is mostly associated with one unique mRNA: diacylglycerol kinase kappa (Dgkκ), a master regulator that controls the switch between diacylglycerol and phosphatidic acid signaling pathways. The absence of FMRP in neurons abolishes group 1 metabotropic glutamate receptor-dependent DGK activity combined with a loss of Dgkκ expression. The reduction of Dgkκ in neurons is sufficient to cause dendritic spine abnormalities, synaptic plasticity alterations, and behavior disorders similar to those observed in the FXS mouse model. Overexpression of Dgkκ in neurons is able to rescue the dendritic spine defects of the Fragile X Mental Retardation 1 gene KO neurons. Together, these data suggest that Dgkκ deregulation contributes to FXS pathology and support a model where FMRP, by controlling the translation of Dgkκ, indirectly controls synaptic proteins translation and membrane properties by impacting lipid signaling in dendritic spine.

Skeletal muscle repair in a mouse model of nemaline myopathy

PubMed Central

Sanoudou, Despina; Corbett, Mark A.; Han, Mei; Ghoddusi, Majid; Nguyen, Mai-Anh T.; Vlahovich, Nicole; Hardeman, Edna C.; Beggs, Alan H.

2012-01-01

Nemaline myopathy (NM), the most common non-dystrophic congenital myopathy, is a variably severe neuromuscular disorder for which no effective treatment is available. Although a number of genes have been identified in which mutations can cause NM, the pathogenetic mechanisms leading to the phenotypes are poorly understood. To address this question, we examined gene expression patterns in an NM mouse model carrying the human Met9Arg mutation of alpha-tropomyosin slow (Tpm3). We assessed five different skeletal muscles from affected mice, which are representative of muscles with differing fiber-type compositions, different physiological specializations and variable degrees of pathology. Although these same muscles in non-affected mice showed marked variation in patterns of gene expression, with diaphragm being the most dissimilar, the presence of the mutant protein in nemaline muscles resulted in a more similar pattern of gene expression among the muscles. This result suggests a common process or mechanism operating in nemaline muscles independent of the variable degrees of pathology. Transcriptional and protein expression data indicate the presence of a repair process and possibly delayed maturation in nemaline muscles. Markers indicative of satellite cell number, activated satellite cells and immature fibers including M-Cadherin, MyoD, desmin, Pax7 and Myf6 were elevated by western-blot analysis or immunohistochemistry. Evidence suggesting elevated focal repair was observed in nemaline muscle in electron micrographs. This analysis reveals that NM is characterized by a novel repair feature operating in multiple different muscles. PMID:16877500

Skeletal muscle repair in a mouse model of nemaline myopathy.

PubMed

Sanoudou, Despina; Corbett, Mark A; Han, Mei; Ghoddusi, Majid; Nguyen, Mai-Anh T; Vlahovich, Nicole; Hardeman, Edna C; Beggs, Alan H

2006-09-01

Nemaline myopathy (NM), the most common non-dystrophic congenital myopathy, is a variably severe neuromuscular disorder for which no effective treatment is available. Although a number of genes have been identified in which mutations can cause NM, the pathogenetic mechanisms leading to the phenotypes are poorly understood. To address this question, we examined gene expression patterns in an NM mouse model carrying the human Met9Arg mutation of alpha-tropomyosin slow (Tpm3). We assessed five different skeletal muscles from affected mice, which are representative of muscles with differing fiber-type compositions, different physiological specializations and variable degrees of pathology. Although these same muscles in non-affected mice showed marked variation in patterns of gene expression, with diaphragm being the most dissimilar, the presence of the mutant protein in nemaline muscles resulted in a more similar pattern of gene expression among the muscles. This result suggests a common process or mechanism operating in nemaline muscles independent of the variable degrees of pathology. Transcriptional and protein expression data indicate the presence of a repair process and possibly delayed maturation in nemaline muscles. Markers indicative of satellite cell number, activated satellite cells and immature fibers including M-Cadherin, MyoD, desmin, Pax7 and Myf6 were elevated by western-blot analysis or immunohistochemistry. Evidence suggesting elevated focal repair was observed in nemaline muscle in electron micrographs. This analysis reveals that NM is characterized by a novel repair feature operating in multiple different muscles.

The Rachitic Tooth

PubMed Central

Nociti, Francisco H.; Somerman, Martha J.

2014-01-01

Teeth are mineralized organs composed of three unique hard tissues, enamel, dentin, and cementum, and supported by the surrounding alveolar bone. Although odontogenesis differs from osteogenesis in several respects, tooth mineralization is susceptible to similar developmental failures as bone. Here we discuss conditions fitting under the umbrella of rickets, which traditionally referred to skeletal disease associated with vitamin D deficiency but has been more recently expanded to include newly identified factors involved in endocrine regulation of vitamin D, phosphate, and calcium, including phosphate-regulating endopeptidase homolog, X-linked, fibroblast growth factor 23, and dentin matrix protein 1. Systemic mineral metabolism intersects with local regulation of mineralization, and factors including tissue nonspecific alkaline phosphatase are necessary for proper mineralization, where rickets can result from loss of activity of tissue nonspecific alkaline phosphatase. Individuals suffering from rickets often bear the additional burden of a defective dentition, and transgenic mouse models have aided in understanding the nature and mechanisms involved in tooth defects, which may or may not parallel rachitic bone defects. This report reviews dental effects of the range of rachitic disorders, including discussion of etiologies of hereditary forms of rickets, a survey of resulting bone and tooth mineralization disorders, and a discussion of mechanisms, known and hypothesized, involved in the observed dental pathologies. Descriptions of human pathology are augmented by analysis of transgenic mouse models, and new interpretations are brought to bear on questions of how teeth are affected under conditions of rickets. In short, the rachitic tooth will be revealed. PMID:23939820

Amyloid Plaques in PSAPP Mice Bind Less Metal than Plaques in Human Alzheimer's Disease

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

Leskovjan, A.; Lanzirotti, A; Miller, L

2009-01-01

Amyloid beta (A{Beta}) is the primary component of Alzheimer's disease (AD) plaques, a key pathological feature of the disease. Metal ions of zinc (Zn), copper (Cu), iron (Fe), and calcium (Ca) are elevated in human amyloid plaques and are thought to be involved in neurodegeneration. Transgenic mouse models of AD also exhibit amyloid plaques, but fail to exhibit the high degree of neurodegeneration observed in humans. In this study, we imaged the Zn, Cu, Fe, and Ca ion distribution in the PSAPP transgenic mouse model representing end-stage AD (N = 6) using synchrotron X-ray fluorescence (XRF) microprobe. In order tomore » account for differences in density in the plaques, the relative protein content was imaged with synchrotron Fourier transform infrared microspectroscopy (FTIRM) on the same samples. FTIRM results revealed a 61% increase in protein content in the plaques compared to the surrounding tissue. After normalizing to protein density, we found that the PSAPP plaques contained only a 29% increase in Zn and there was actually less Cu, Fe, and Ca in the plaque compared to the surrounding tissue. Since metal binding to A{beta} is thought to induce redox chemistry that is toxic to neurons, the reduced metal binding in PSAPP mice is consistent with the lack of neurodegeneration in these animals. These findings were in stark contrast to the high metal ion content observed in human AD plaques, further implicating the role of metal ions in human AD pathology.« less

Defining the molecular pathologies in cloaca malformation: similarities between mouse and human

PubMed Central

Runck, Laura A.; Method, Anna; Bischoff, Andrea; Levitt, Marc; Peña, Alberto; Collins, Margaret H.; Gupta, Anita; Shanmukhappa, Shiva; Wells, James M.; Guasch, Géraldine

2014-01-01

Anorectal malformations are congenital anomalies that form a spectrum of disorders, from the most benign type with excellent functional prognosis, to very complex, such as cloaca malformation in females in which the rectum, vagina and urethra fail to develop separately and instead drain via a single common channel into the perineum. The severity of this phenotype suggests that the defect occurs in the early stages of embryonic development of the organs derived from the cloaca. Owing to the inability to directly investigate human embryonic cloaca development, current research has relied on the use of mouse models of anorectal malformations. However, even studies of mouse embryos lack analysis of the earliest stages of cloaca patterning and morphogenesis. Here we compared human and mouse cloaca development and retrospectively identified that early mis-patterning of the embryonic cloaca might underlie the most severe forms of anorectal malformation in humans. In mouse, we identified that defective sonic hedgehog (Shh) signaling results in early dorsal-ventral epithelial abnormalities prior to the reported defects in septation. This is manifested by the absence of Sox2 and aberrant expression of keratins in the embryonic cloaca of Shh knockout mice. Shh knockout embryos additionally develop a hypervascular stroma, which is defective in BMP signaling. These epithelial and stromal defects persist later, creating an indeterminate epithelium with molecular alterations in the common channel. We then used these animals to perform a broad comparison with patients with mild-to-severe forms of anorectal malformations including cloaca malformation. We found striking parallels with the Shh mouse model, including nearly identical defective molecular identity of the epithelium and surrounding stroma. Our work strongly suggests that early embryonic cloacal epithelial differentiation defects might be the underlying cause of severe forms of anorectal malformations in humans. Moreover, deranged Shh and BMP signaling is correlated with severe anorectal malformations in both mouse and humans. PMID:24524909

Novel approaches to models of Alzheimer's disease pathology for drug screening and development.

PubMed

Shaughnessy, Laura; Chamblin, Beth; McMahon, Lori; Nair, Ayyappan; Thomas, Mary Beth; Wakefield, John; Koentgen, Frank; Ramabhadran, Ram

2004-01-01

Development of therapeutics for Alzheimer's disease (AD) requires appropriate cell culture models that reflect the errant biochemical pathways and animal models that reflect the pathological hallmarks of the disease as well as the clinical manifestations. In the past two decades AD research has benefited significantly from the use of genetically engineered cell lines expressing components of the amyloid-generating pathway, as well as from the study of transgenic mice that develop the pathological hallmarks of the disease, mainly neuritic plaques. The choice of certain cell types and the choice of mouse as the model organism have been mandated by the feasibility of introduction and expression of foreign genes into these model systems. We describe a universal and efficient gene-delivery system, using lentiviral vectors, that permits the development of relevant cell biological systems using neuronal cells, including primary neurons and animal models in mammalian species best suited for the study of AD. In addition, lentiviral gene delivery provides avenues for creation of novel models by direct and prolonged expression of genes in the brain in any vertebrate animal. TranzVector is a lentiviral vector optimized for efficiency and safety that delivers genes to cells in culture, in tissue explants, and in live animals regardless of the dividing or differentiated status of the cells. Genes can also be delivered efficiently to fertilized single-cell-stage embryos of a wide range of mammalian species, broadening the range of the model organism (from rats to nonhuman primates) for the study of disease mechanism as well as for development of therapeutics. Copyright 2004 Humana Press Inc.

Glucocorticoid Steroid and Alendronate Treatment Alleviates Dystrophic Phenotype with Enhanced Functional Glycosylation of α-Dystroglycan in Mouse Model of Limb-Girdle Muscular Dystrophy with FKRPP448L Mutation.

PubMed

Wu, Bo; Shah, Sapana N; Lu, Peijuan; Richardson, Stephanie M; Bollinger, Lauren E; Blaeser, Anthony; Madden, Kyle L; Sun, Yubo; Luckie, Taylor M; Cox, Michael D; Sparks, Susan; Harper, Amy D; Lu, Qi Long

2016-06-01

Fukutin-related protein-muscular dystrophy is characterized by defects in glycosylation of α-dystroglycan with variable clinical phenotypes, most commonly as limb-girdle muscular dystrophy 2I. There is no effective therapy available. Glucocorticoid steroids have become the standard treatment for Duchenne and other muscular dystrophies with serious adverse effects, including excessive weight gain, immune suppression, and bone loss. Bisphosphonates have been used to treat Duchenne muscular dystrophy for prevention of osteoporosis. Herein, we evaluated prednisolone and alendronate for their therapeutic potential in the FKRPP448L-mutant mouse representing moderate limb-girdle muscular dystrophy 2I. Mice were treated with prednisolone, alendronate, and both in combination for up to 6 months. Prednisolone improved muscle pathology with significant reduction in muscle degeneration, but had no effect on serum creatine kinase levels and muscle strength. Alendronate treatment did not ameliorate muscle degeneration, but demonstrated a limited enhancement on muscle function test. Combined treatment of prednisolone and alendronate provided best improvement in muscle pathology with normalized fiber size distribution and significantly reduced serum creatine kinase levels, but had limited effect on muscle force generation. The use of alendronate significantly mitigated the bone loss. Prednisolone alone and in combination with alendronate enhance functionally glycosylated α-dystroglycan. These results, for the first time, demonstrate the efficacy and feasibility of this alliance treatment of the two drugs for fukutin-related protein-muscular dystrophy. Copyright © 2016 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.

Defective phagosome motility and degradation in cell nonautonomous RPE pathogenesis of a dominant macular degeneration.

PubMed

Esteve-Rudd, Julian; Hazim, Roni A; Diemer, Tanja; Paniagua, Antonio E; Volland, Stefanie; Umapathy, Ankita; Williams, David S

2018-05-22

Stargardt macular dystrophy 3 (STGD3) is caused by dominant mutations in the ELOVL4 gene. Like other macular degenerations, pathogenesis within the retinal pigment epithelium (RPE) appears to contribute to the loss of photoreceptors from the central retina. However, the RPE does not express ELOVL4 , suggesting photoreceptor cell loss in STGD3 occurs through two cell nonautonomous events: mutant photoreceptors first affect RPE cell pathogenesis, and then, second, RPE dysfunction leads to photoreceptor cell death. Here, we have investigated how the RPE pathology occurs, using a STGD3 mouse model in which mutant human ELOVL4 is expressed in the photoreceptors. We found that the mutant protein was aberrantly localized to the photoreceptor outer segment (POS), and that resulting POS phagosomes were degraded more slowly in the RPE. In cell culture, the mutant POSs are ingested by primary RPE cells normally, but the phagosomes are processed inefficiently, even by wild-type RPE. The mutant phagosomes excessively sequester RAB7A and dynein, and have impaired motility. We propose that the abnormal presence of ELOVL4 protein in POSs results in phagosomes that are defective in recruiting appropriate motor protein linkers, thus contributing to slower degradation because their altered motility results in slower basal migration and fewer productive encounters with endolysosomes. In the transgenic mouse retinas, the RPE accumulated abnormal-looking phagosomes and oxidative stress adducts; these pathological changes were followed by pathology in the neural retina. Our results indicate inefficient phagosome degradation as a key component of the first cell nonautonomous event underlying retinal degeneration due to mutant ELOVL4.

Aldolase-B knockout in mice phenocopies hereditary fructose intolerance in humans.

PubMed

Oppelt, Sarah A; Sennott, Erin M; Tolan, Dean R

2015-03-01

The rise in fructose consumption, and its correlation with symptoms of metabolic syndrome (MBS), has highlighted the need for a better understanding of fructose metabolism. To that end, valid rodent models reflecting the same metabolism as in humans, both biochemically and physiologically, are critical. A key to understanding any type of metabolism comes from study of disease states that affect such metabolism. A serious defect of fructose metabolism is the autosomal recessive condition called hereditary fructose intolerance (HFI), caused by mutations in the human aldolase B gene (Aldob). Those afflicted with HFI experience liver and kidney dysfunction after fructose consumption, which can lead to death, particularly during infancy. With very low levels of fructose exposure, HFI patients develop non-alcoholic fatty acid liver disease and fibrosis, sharing liver pathologies also seen in MBS. A major step toward establishing that fructose metabolism in mice mimics that of humans is reported by investigating the consequences of targeting the mouse aldolase-B gene (Aldo2) for deletion in mice (Aldo2(-/-)). The Aldo2(-/-) homozygous mice show similar pathology following exposure to fructose as humans with HFI such as failure to thrive, liver dysfunction, and potential morbidity. Establishing that this mouse reflects the symptoms of HFI in humans is critical for comparison of rodent studies to the human condition, where this food source is increasing, and increasingly controversial. This animal should provide a valuable resource for answering remaining questions about fructose metabolism in HFI, as well as help investigate the biochemical mechanisms leading to liver pathologies seen in MBS from high fructose diets. Copyright © 2015 Elsevier Inc. All rights reserved.

The Naïve Murine Cornea as a Model System to Identify Novel Endogenous Regulators of Lymphangiogenesis: TRAIL and rtPA.

PubMed

Regenfuß, Birgit; Dreisow, Marie-Luise; Hos, Deniz; Masli, Sharmila; Bock, Felix; Cursiefen, Claus

2015-06-01

In the murine cornea, which is an established model for analyzing pathologic lymphatic vessel growth, phenotypic heterogeneity of the endogenous lymphatic vessels in the limbus of the cornea was previously described. In this study, the cornea of BALB/c, C57BL/6, and FVB mice with different limbal lymphangiogenic phenotypes was analyzed to identify novel candidates potentially influencing lymphatic vessel growth. Pathway specific expression analysis of the cornea was performed to identify novel candidate genes. Corneal protein expression of the respective candidates was analyzed by fluorescent immunohistochemistry. The effect of the candidates on proliferation of human dermal lymphatic endothelial cells (HDLECs) was analyzed by BrdU proliferation ELISA. Thirteen genes were differentially regulated in corneas of mouse strains with more endogenous limbal lymphatic vessels (high-lymphangiogenic) (C57BL/6) compared to mouse strains with less endogenous limbal lymphatic vessels (low-lymphangiogenic) (BALB/c, FVB). Two candidates, Tumor necrosis factor (ligand) superfamily member 10 (Tnfsf10/Trail) and Plasminogen activator, tissue (Plat/tPA) were expressed in the cornea of BALB/c and C57BL/6 mice on the protein level. In vitro, Trail and recombinant tPA inhibited the proliferation of human dermal lymphatic endothelial cells. Molecular analysis of the naive cornea in mouse strains with different limbal lymphatic phenotypes is a valuable model to identify novel endogenous regulators of lymphangiogenesis.

A mouse model for the cystic fibrosis delta F508 mutation.

PubMed Central

van Doorninck, J H; French, P J; Verbeek, E; Peters, R H; Morreau, H; Bijman, J; Scholte, B J

1995-01-01

Most cystic fibrosis (CF) patients produce a mutant form (delta F508) of the cystic fibrosis transmembrane conductance regulator (CFTR), which is not properly processed in normal cells but is active as a chloride channel in several experimental systems. We used a double homologous recombination ('Hit and Run') procedure to generate a mouse model for the delta F508 mutation. Targeted embryonic stem (ES) cells (Hit clones) were found; of these either 80 or 20% of the clones had lost the delta F508 mutation, depending on the distance between the linearization site in the targeting construct and the delta F508 mutation. Correctly targeted clones underwent a second selection step resulting in ES cell clones (Run clones) heterozygous for the delta F508 mutation with an efficiency of 2-7%. Chimeric mice were generated and offspring homozygous for the delta F508 mutation showed electrophysiological abnormalities in nasal epithelium, gallbladder and in the intestine, and histological abnormalities in the intestine, typical of CF. Our data suggest that the delta F508 mice have residual delta F508 CFTR activity which would explain the mild pathology of the delta F508 mice. The delta F508 mouse may provide a useful model for the study of the processing defect of delta F508 CFTR and for the development of novel therapeutic approaches based on circumvention of the processing block. Images PMID:7556083

Impact of N-tau on adult hippocampal neurogenesis, anxiety, and memory.

PubMed

Pristerà, Andrea; Saraulli, Daniele; Farioli-Vecchioli, Stefano; Strimpakos, Georgios; Costanzi, Marco; di Certo, Maria Grazia; Cannas, Sara; Ciotti, Maria Teresa; Tirone, Felice; Mattei, Elisabetta; Cestari, Vincenzo; Canu, Nadia

2013-11-01

Different pathological tau species are involved in memory loss in Alzheimer's disease, the most common cause of dementia among older people. However, little is known about how tau pathology directly affects adult hippocampal neurogenesis, a unique form of structural plasticity implicated in hippocampus-dependent spatial learning and mood-related behavior. To this aim, we generated a transgenic mouse model conditionally expressing a pathological tau fragment (26-230 aa of the longest human tau isoform, or N-tau) in nestin-positive stem/progenitor cells. We found that N-tau reduced the proliferation of progenitor cells in the adult dentate gyrus, reduced cell survival and increased cell death by a caspase-3-independent mechanism, and recruited microglia. Although the number of terminally differentiated neurons was reduced, these showed an increased dendritic arborization and spine density. This resulted in an increase of anxiety-related behavior and an impairment of episodic-like memory, whereas less complex forms of spatial learning remained unaltered. Understanding how pathological tau species directly affect neurogenesis is important for developing potential therapeutic strategies to direct neurogenic instructive cues for hippocampal function repair. Copyright © 2013 Elsevier Inc. All rights reserved.

Hematopoietic Kit Deficiency, rather than Lack of Mast Cells, Protects Mice from Obesity and Insulin Resistance.

PubMed

Gutierrez, Dario A; Muralidhar, Sathya; Feyerabend, Thorsten B; Herzig, Stephan; Rodewald, Hans-Reimer

2015-05-05

Obesity, insulin resistance, and related pathologies are associated with immune-mediated chronic inflammation. Kit mutant mice are protected from diet-induced obesity and associated co-morbidities, and this phenotype has previously been attributed to their lack of mast cells. We performed a comprehensive metabolic analysis of Kit-dependent Kit(W/Wv) and Kit-independent Cpa3(Cre/+) mast-cell-deficient mouse strains, employing diet-induced or genetic (Lep(Ob/Ob) background) models of obesity. Our results show that mast cell deficiency, in the absence of Kit mutations, plays no role in the regulation of weight gain or insulin resistance. Moreover, we provide evidence that the metabolic phenotype observed in Kit mutant mice, while independent of mast cells, is immune regulated. Our data underscore the value of definitive mast cell deficiency models to conclusively test the involvement of this enigmatic cell in immune-mediated pathologies and identify Kit as a key hematopoietic factor in the pathogenesis of metabolic syndrome. Copyright © 2015 Elsevier Inc. All rights reserved.

Combination brain and systemic injections of AAV provide maximal functional and survival benefits in the Niemann-Pick mouse.

PubMed

Passini, Marco A; Bu, Jie; Fidler, Jonathan A; Ziegler, Robin J; Foley, Joseph W; Dodge, James C; Yang, Wendy W; Clarke, Jennifer; Taksir, Tatyana V; Griffiths, Denise A; Zhao, Michael A; O'Riordan, Catherine R; Schuchman, Edward H; Shihabuddin, Lamya S; Cheng, Seng H

2007-05-29

Niemann-Pick disease (NPD) is caused by the loss of acid sphingomyelinase (ASM) activity, which results in widespread accumulation of undegraded lipids in cells of the viscera and CNS. In this study, we tested the effect of combination brain and systemic injections of recombinant adeno-associated viral vectors encoding human ASM (hASM) in a mouse model of NPD. Animals treated by combination therapy exhibited high levels of hASM in the viscera and brain, which resulted in near-complete correction of storage throughout the body. This global reversal of pathology translated to normal weight gain and superior recovery of motor and cognitive functions compared to animals treated by either brain or systemic injection alone. Furthermore, animals in the combination group did not generate antibodies to hASM, demonstrating the first application of systemic-mediated tolerization to improve the efficacy of brain injections. All of the animals treated by combination therapy survived in good health to an investigator-selected 54 weeks, whereas the median lifespans of the systemic-alone, brain-alone, or untreated ASM knockout groups were 47, 48, and 34 weeks, respectively. These data demonstrate that combination therapy is a promising therapeutic modality for treating NPD and suggest a potential strategy for treating disease indications that cause both visceral and CNS pathologies.

Osteoarthritis-like pathologic changes in the knee joint induced by environmental disruption of circadian rhythms is potentiated by a high-fat diet.

PubMed

Kc, Ranjan; Li, Xin; Forsyth, Christopher B; Voigt, Robin M; Summa, Keith C; Vitaterna, Martha Hotz; Tryniszewska, Beata; Keshavarzian, Ali; Turek, Fred W; Meng, Qing-Jun; Im, Hee-Jeong

2015-11-20

A variety of environmental factors contribute to progressive development of osteoarthritis (OA). Environmental factors that upset circadian rhythms have been linked to various diseases. Our recent work establishes chronic environmental circadian disruption - analogous to rotating shiftwork-associated disruption of circadian rhythms in humans - as a novel risk factor for the development of OA. Evidence suggests shift workers are prone to obesity and also show altered eating habits (i.e., increased preference for high-fat containing food). In the present study, we investigated the impact of chronic circadian rhythm disruption in combination with a high-fat diet (HFD) on progression of OA in a mouse model. Our study demonstrates that when mice with chronically circadian rhythms were fed a HFD, there was a significant proteoglycan (PG) loss and fibrillation in knee joint as well as increased activation of the expression of the catabolic mediators involved in cartilage homeostasis. Our results, for the first time, provide the evidence that environmental disruption of circadian rhythms plus HFD potentiate OA-like pathological changes in the mouse joints. Thus, our findings may open new perspectives on the interactions of chronic circadian rhythms disruption with diet in the development of OA and may have potential clinical implications.

Three-dimensional analysis of the early development of the dentition

PubMed Central

Peterkova, R; Hovorakova, M; Peterka, M; Lesot, H

2014-01-01

Tooth development has attracted the attention of researchers since the 19th century. It became obvious even then that morphogenesis could not fully be appreciated from two-dimensional histological sections. Therefore, methods of three-dimensional (3D) reconstructions were employed to visualize the surface morphology of developing structures and to help appreciate the complexity of early tooth morphogenesis. The present review surveys the data provided by computer-aided 3D analyses to update classical knowledge of early odontogenesis in the laboratory mouse and in humans. 3D reconstructions have demonstrated that odontogenesis in the early stages is a complex process which also includes the development of rudimentary odontogenic structures with different fates. Their developmental, evolutionary, and pathological aspects are discussed. The combination of in situ hybridization and 3D reconstruction have demonstrated the temporo-spatial dynamics of the signalling centres that reflect transient existence of rudimentary tooth primordia at loci where teeth were present in ancestors. The rudiments can rescue their suppressed development and revitalize, and then their subsequent autonomous development can give rise to oral pathologies. This shows that tooth-forming potential in mammals can be greater than that observed from their functional dentitions. From this perspective, the mouse rudimentary tooth primordia represent a natural model to test possibilities of tooth regeneration. PMID:24495023

Significance of perivascular tumour cells defined by CD109 expression in progression of glioma.

PubMed

Shiraki, Yukihiro; Mii, Shinji; Enomoto, Atsushi; Momota, Hiroyuki; Han, Yi-Peng; Kato, Takuya; Ushida, Kaori; Kato, Akira; Asai, Naoya; Murakumo, Yoshiki; Aoki, Kosuke; Suzuki, Hiromichi; Ohka, Fumiharu; Wakabayashi, Toshihiko; Todo, Tomoki; Ogawa, Seishi; Natsume, Atsushi; Takahashi, Masahide

2017-12-01

In the progression of glioma, tumour cells often exploit the perivascular microenvironment to promote their survival and resistance to conventional therapies. Some of these cells are considered to be brain tumour stem cells (BTSCs); however, the molecular nature of perivascular tumour cells has not been specifically clarified because of the complexity of glioma. Here, we identified CD109, a glycosylphosphatidylinositol-anchored protein and regulator of multiple signalling pathways, as a critical regulator of the progression of lower-grade glioma (World Health Organization grade II/III) by clinicopathological and whole-genome sequencing analysis of tissues from human glioma. The importance of CD109-positive perivascular tumour cells was confirmed not only in human lower-grade glioma tissues but also in a mouse model that recapitulated human glioma. Intriguingly, BTSCs isolated from mouse glioma expressed high levels of CD109. CD109-positive BTSCs exerted a proliferative effect on differentiated glioma cells treated with temozolomide. These data reveal the significance of tumour cells that populate perivascular regions during glioma progression, and indicate that CD109 is a potential therapeutic target for the disease. Copyright © 2017 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd. Copyright © 2017 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Profiling Lgals9 splice variant expression at the fetal-maternal interface: implications in normal and pathological human pregnancy.

PubMed

Heusschen, Roy; Freitag, Nancy; Tirado-González, Irene; Barrientos, Gabriela; Moschansky, Petra; Muñoz-Fernández, Raquel; Leno-Durán, Ester; Klapp, Burghard F; Thijssen, Victor L J L; Blois, Sandra M

2013-01-01

Disruption of fetal-maternal tolerance mechanisms can contribute to pregnancy complications, including spontaneous abortion. Galectin-9 (LGALS9), a tandem repeat lectin associated with immune modulation, is expressed in the endometrium during the mid and late secretory phases and in decidua during human early pregnancy. However, the role of LGALS9 during pregnancy remains poorly understood. We used real-time PCR and immunohistochemical staining to analyze the expression of Lgals9/LGALS9 during mouse gestation as well as in human tissues obtained from normal pregnancy and spontaneous abortions. In mice, three Lgals9 splice variants were detected, the expression of which was differentially regulated during gestation. Furthermore, decidual Lgals9 expression was deregulated in a mouse model of spontaneous abortion, whereas placental levels did not change. We further found that the LGALS9 D5 isoform suppresses interferon gamma production by decidual natural killer cells. In human patients, six Lgals9 splice variants were detected, and a decrease in Lgals9 D5/10 was associated with spontaneous abortion. Altogether, these results show a differential regulation of Lgals9 isoform expression during normal and pathological pregnancies and designate Lgals9 as a potential marker for adverse pregnancy outcomes.

Mitochondrial genetic background modulates bioenergetics and susceptibility to acute cardiac volume overload.

PubMed

Fetterman, Jessica L; Zelickson, Blake R; Johnson, Larry W; Moellering, Douglas R; Westbrook, David G; Pompilius, Melissa; Sammy, Melissa J; Johnson, Michelle; Dunham-Snary, Kimberly J; Cao, Xuemei; Bradley, Wayne E; Zhang, Jinju; Wei, Chih-Chang; Chacko, Balu; Schurr, Theodore G; Kesterson, Robert A; Dell'italia, Louis J; Darley-Usmar, Victor M; Welch, Danny R; Ballinger, Scott W

2013-10-15

Dysfunctional bioenergetics has emerged as a key feature in many chronic pathologies such as diabetes and cardiovascular disease. This has led to the mitochondrial paradigm in which it has been proposed that mtDNA sequence variation contributes to disease susceptibility. In the present study we show a novel animal model of mtDNA polymorphisms, the MNX (mitochondrial-nuclear exchange) mouse, in which the mtDNA from the C3H/HeN mouse has been inserted on to the C57/BL6 nuclear background and vice versa to test this concept. Our data show a major contribution of the C57/BL6 mtDNA to the susceptibility to the pathological stress of cardiac volume overload which is independent of the nuclear background. Mitochondria harbouring the C57/BL6J mtDNA generate more ROS (reactive oxygen species) and have a higher mitochondrial membrane potential relative to those with C3H/HeN mtDNA, independent of nuclear background. We propose this is the primary mechanism associated with increased bioenergetic dysfunction in response to volume overload. In summary, these studies support the 'mitochondrial paradigm' for the development of disease susceptibility, and show that the mtDNA modulates cellular bioenergetics, mitochondrial ROS generation and susceptibility to cardiac stress.

Mitochondrial Genetic Background Modulates Bioenergetics and Susceptibility to Acute Cardiac Volume – Overload

PubMed Central

Fetterman, Jessica L.; Zelickson, Blake R.; Johnson, Larry W.; Moellering, Douglas R.; Westbrook, David G.; Pompilius, Melissa; Sammy, Melissa J.; Johnson, Michelle; Dunham-Snary, Kimberly J.; Cao, Xuemei; Bradley, Wayne E.; Zhang, Jinju; Wei, Chih-Chang; Chacko, Balu; Schurr, Theodore G.; Kesterson, Robert A.; Dell’Italia, Louis J.; Darley-Usmar, Victor M.; Welch, Danny R.; Ballinger, Scott W.

2013-01-01

Synopsis Dysfunctional bioenergetics has emerged as a key feature in many chronic pathologies such as diabetes and cardiovascular disease. This has led to the mitochondrial paradigm in which it has been proposed that mitochondrial DNA (mtDNA) sequence variation contributes to disease susceptibility. In this study we present a novel animal model of mtDNA polymorphisms, the mitochondrial nuclear exchange mouse (MNX), in which the mtDNA from C3H/HeN mouse has been inserted onto the C57/BL6 nuclear background and vice versa to test this concept. Our data show a major contribution of the C57/BL6 mtDNA to the susceptibility to the pathological stress of cardiac volume overload which is independent of the nuclear background. Mitochondria harboring the C57/BL6J mtDNA generate more reactive oxygen species (ROS) and have a higher mitochondrial membrane potential relative to those having the C3H/HeN mtDNA, independent of nuclear background. We propose this is the primary mechanism associated with increased bioenergetic dysfunction in response to volume overload. In summary, these studies support the “mitochondrial paradigm” for the development of disease susceptibility, and show that the mtDNA modulates, cellular bioenergetics, mitochondrial reactive oxygen species generation and susceptibility to cardiac stress. PMID:23924350

Proceedings of the 2013 National Toxicology Program Satellite Symposium

PubMed Central

Elmore, Susan A.; Boyle, Michael C.; Boyle, Molly H.; Cora, Michelle C.; Crabbs, Torrie A.; Cummings, Connie A.; Gruebbel, Margarita M.; Johnson, Crystal L.; Malarkey, David E.; McInnes, Elizabeth F.; Nolte, Thomas; Shackelford, Cynthia C.; Ward, Jerrold M.

2014-01-01

The 2013 annual National Toxicology Program (NTP) Satellite Symposium, entitled “Pathology Potpourri” was held in Portland, Oregon in advance of the Society of Toxicologic Pathology's 32nd annual meeting. The goal of the NTP Symposium is to present current diagnostic pathology or nomenclature issues to the toxicologic pathology community. This article presents summaries of the speakers' presentations, including diagnostic or nomenclature issues that were presented, along with select images that were used for audience voting and discussion. Some lesions and topics covered during the symposium included a caudal tail vertebra duplication in mice; nephroblastematosis in rats; ectopic C cell tumor in a hamster; granular cell aggregates/tumor in the uterus of a hamster; Pneumocystis carinii in the lung of a rat; iatrogenic chronic inflammation in the lungs of control rats; hepatoblastoma arising within an adenoma in a mouse; humoral hypercalcemia of benignancy in a transgenic mouse; acetaminophen induced hepatoxicity in rats; electron microscopy images of iatrogenic intraerythrocytic inclusions in transgenic mice; questionable hepatocellular degeneration/cell death/artifact in rats; atypical endometrial hyperplasia in rats; malignant mixed Müllerian tumors/carcinosarcomas in rats; differential diagnoses of proliferative lesions the intestine of rodents; and finally obstructive nephropathy caused by melamine poisoning in a rat. PMID:24334674

Effect of human milk as a treatment for dry eye syndrome in a mouse model

PubMed Central

Diego, Jose L.; Bidikov, Luke; Pedler, Michelle G.; Kennedy, Jeffrey B.; Quiroz-Mercado, Hugo; Gregory, Darren G.; Petrash, J. Mark

2016-01-01

Purpose Dry eye syndrome (DES) affects millions of people worldwide. Homeopathic remedies to treat a wide variety of ocular diseases have previously been documented in the literature, but little systematic work has been performed to validate the remedies’ efficacy using accepted laboratory models of disease. The purpose of this study was to evaluate the efficacy of human milk and nopal cactus (prickly pear), two widely used homeopathic remedies, as agents to reduce pathological markers of DES. Methods The previously described benzalkonium chloride (BAK) dry eye mouse model was used to study the efficacy of human milk and nopal cactus (prickly pear). BAK (0.2%) was applied to the mouse ocular surface twice daily to induce dry eye pathology. Fluorescein staining was used to verify that the animals had characteristic signs of DES. After induction of DES, the animals were treated with human milk (whole and fat-reduced), nopal, nopal extract derivatives, or cyclosporine four times daily for 7 days. Punctate staining and preservation of corneal epithelial thickness, measured histologically at the end of treatment, were used as indices of therapeutic efficacy. Results Treatment with BAK reduced the mean corneal epithelial thickness from 36.77±0.64 μm in the control mice to 21.29±3.2 μm. Reduction in corneal epithelial thickness was largely prevented by administration of whole milk (33.2±2.5 μm) or fat-reduced milk (36.1±1.58 μm), outcomes that were similar to treatment with cyclosporine (38.52±2.47 μm), a standard in current dry eye therapy. In contrast, crude or filtered nopal extracts were ineffective at preventing BAK-induced loss of corneal epithelial thickness (24.76±1.78 μm and 27.99±2.75 μm, respectively), as were solvents used in the extraction of nopal materials (26.53±1.46 μm for ethyl acetate, 21.59±5.87 μm for methanol). Epithelial damage, as reflected in the punctate scores, decreased over 4 days of treatment with whole and fat-reduced milk but continued to increase in eyes treated with nopal-derived materials. Conclusions Whole and fat-reduced human milk showed promising effects in the prevention of BAK-induced loss of corneal epithelial thickness and epithelial damage in this mouse model. Further studies are required to determine whether human milk may be safely used to treat dry eye in patients. PMID:27667918

Effect of human milk as a treatment for dry eye syndrome in a mouse model.

PubMed

Diego, Jose L; Bidikov, Luke; Pedler, Michelle G; Kennedy, Jeffrey B; Quiroz-Mercado, Hugo; Gregory, Darren G; Petrash, J Mark; McCourt, Emily A

Dry eye syndrome (DES) affects millions of people worldwide. Homeopathic remedies to treat a wide variety of ocular diseases have previously been documented in the literature, but little systematic work has been performed to validate the remedies' efficacy using accepted laboratory models of disease. The purpose of this study was to evaluate the efficacy of human milk and nopal cactus (prickly pear), two widely used homeopathic remedies, as agents to reduce pathological markers of DES. The previously described benzalkonium chloride (BAK) dry eye mouse model was used to study the efficacy of human milk and nopal cactus (prickly pear). BAK (0.2%) was applied to the mouse ocular surface twice daily to induce dry eye pathology. Fluorescein staining was used to verify that the animals had characteristic signs of DES. After induction of DES, the animals were treated with human milk (whole and fat-reduced), nopal, nopal extract derivatives, or cyclosporine four times daily for 7 days. Punctate staining and preservation of corneal epithelial thickness, measured histologically at the end of treatment, were used as indices of therapeutic efficacy. Treatment with BAK reduced the mean corneal epithelial thickness from 36.77±0.64 μm in the control mice to 21.29±3.2 μm. Reduction in corneal epithelial thickness was largely prevented by administration of whole milk (33.2±2.5 μm) or fat-reduced milk (36.1±1.58 μm), outcomes that were similar to treatment with cyclosporine (38.52±2.47 μm), a standard in current dry eye therapy. In contrast, crude or filtered nopal extracts were ineffective at preventing BAK-induced loss of corneal epithelial thickness (24.76±1.78 μm and 27.99±2.75 μm, respectively), as were solvents used in the extraction of nopal materials (26.53±1.46 μm for ethyl acetate, 21.59±5.87 μm for methanol). Epithelial damage, as reflected in the punctate scores, decreased over 4 days of treatment with whole and fat-reduced milk but continued to increase in eyes treated with nopal-derived materials. Whole and fat-reduced human milk showed promising effects in the prevention of BAK-induced loss of corneal epithelial thickness and epithelial damage in this mouse model. Further studies are required to determine whether human milk may be safely used to treat dry eye in patients.

Merits and complexities of modeling multiple sclerosis in non-human primates: implications for drug discovery.

PubMed

't Hart, Bert A; Laman, Jon D; Kap, Yolanda S

2018-05-01

The translation of scientific discoveries made in animal models into effective treatments for patients often fails, indicating that currently used disease models in preclinical research are insufficiently predictive for clinical success. An often-used model in the preclinical research of autoimmune neurological diseases, multiple sclerosis in particular, is experimental autoimmune encephalomyelitis (EAE). Most EAE models are based on genetically susceptible inbred/SPF mouse strains used at adolescent age (10-12 weeks), which lack exposure to genetic and microbial factors which shape the human immune system. Areas covered: Herein, the authors ask whether an EAE model in adult non-human primates from an outbred conventionally-housed colony could help bridge the translational gap between rodent EAE models and MS patients. Particularly, the authors discuss a novel and translationally relevant EAE model in common marmosets (Callithrix jacchus) that shares remarkable pathological similarity with MS. Expert opinion: The MS-like pathology in this model is caused by the interaction of effector memory T cells with B cells infected with the γ1-herpesvirus (CalHV3), both present in the pathogen-educated marmoset immune repertoire. The authors postulate that depletion of only the small subset (<0.05%) of CalHV3-infected B cells may be sufficient to limit chronic inflammatory demyelination.

Histopathology reveals correlative and unique phenotypes in a high-throughput mouse phenotyping screen

PubMed Central

Adissu, Hibret A.; Estabel, Jeanne; Sunter, David; Tuck, Elizabeth; Hooks, Yvette; Carragher, Damian M.; Clarke, Kay; Karp, Natasha A.; Project, Sanger Mouse Genetics; Newbigging, Susan; Jones, Nora; Morikawa, Lily; White, Jacqueline K.; McKerlie, Colin

2014-01-01

The Mouse Genetics Project (MGP) at the Wellcome Trust Sanger Institute aims to generate and phenotype over 800 genetically modified mouse lines over the next 5 years to gain a better understanding of mammalian gene function and provide an invaluable resource to the scientific community for follow-up studies. Phenotyping includes the generation of a standardized biobank of paraffin-embedded tissues for each mouse line, but histopathology is not routinely performed. In collaboration with the Pathology Core of the Centre for Modeling Human Disease (CMHD) we report the utility of histopathology in a high-throughput primary phenotyping screen. Histopathology was assessed in an unbiased selection of 50 mouse lines with (n=30) or without (n=20) clinical phenotypes detected by the standard MGP primary phenotyping screen. Our findings revealed that histopathology added correlating morphological data in 19 of 30 lines (63.3%) in which the primary screen detected a phenotype. In addition, seven of the 50 lines (14%) presented significant histopathology findings that were not associated with or predicted by the standard primary screen. Three of these seven lines had no clinical phenotype detected by the standard primary screen. Incidental and strain-associated background lesions were present in all mutant lines with good concordance to wild-type controls. These findings demonstrate the complementary and unique contribution of histopathology to high-throughput primary phenotyping of mutant mice. PMID:24652767

Minocycline prevents cholinergic loss in a mouse model of Down's syndrome.

PubMed

Hunter, Christopher L; Bachman, David; Granholm, Ann-Charlotte

2004-11-01

Individuals with Down's syndrome develop Alzheimer's-like pathologies comparatively early in life, including progressive degeneration of basal forebrain cholinergic neurons (BFCNs). Cholinergic hypofunction contributes to dementia-related cognitive decline and remains a target of therapeutic intervention for Alzheimer's disease. In light of this, partial trisomy 16 (Ts65Dn) mice have been developed to provide an animal model of Down's syndrome that exhibits progressive loss of BFCNs and cognitive ability. Another feature common to both Down's syndrome and Alzheimer's disease is neuroinflammation, which may exacerbate neurodegeneration, including cholinergic loss. Minocycline is a semisynthetic tetracycline with antiinflammatory properties that has demonstrated neuroprotective properties in certain disease models. Consistent with a role for inflammatory processes in BFCN degeneration, we have shown previously that minocycline protects BFCNs and improves memory in mice with acute, immunotoxic BFCN lesions. We now report that minocycline treatment inhibits microglial activation, prevents progressive BFCN decline, and markedly improves performance of Ts65Dn mice on a working and reference memory task. Minocycline is an established antiinflammatory and neuroprotective drug and may provide a novel approach to treat specific AD-like pathologies.

Comparison of mHTT Antibodies in Huntington’s Disease Mouse Models Reveal Specific Binding Profiles and Steady-State Ubiquitin Levels with Disease Development

PubMed Central

Bayram-Weston, Zubeyde; Jones, Lesley; Dunnett, Stephen B.; Brooks, Simon P.

2016-01-01

Huntington’s disease (HD) cellular pathology is characterised by the aggregation of mutant huntingtin (mHTT) protein into inclusion bodies. The present paper compared the sensitivity of five widely used mHTT antibodies (S830; MW8; EM48; 1C2; ubiquitin) against mice from five commonly used HD mouse models (R6/1; YAC128; HdhQ92; B6 HdhQ150; B6 x129/Ola HdhQ150) at two ages to determine: the most sensitive antibodies for each model; whether mHTT antibody binding differed depending on aggregation stage (diffuse versus frank inclusion); the role of ubiquitin during aggregation as the ubiquitin proteosome system has been implicated in disease development. The models demonstrated unique profiles of antibody binding even when the models varied only by background strain (HdhQ150). MW8 was highly sensitive for detecting frank inclusions in all lines whereas EM48, ubiquitin and 1C2 demonstrated consistent staining in all models irrespective of age or form of mHTT. MW8 and S830 were the most sensitive antibodies with 1C2 the least. Ubiquitin levels were stable for each model regardless of age. Ubiquitin was particularly sensitive in young YAC128 mice that demonstrate an absence of inclusions until ~12 months of age suggesting high affinity to mHTT in its diffuse form. The data indicate that generalisations across models regarding the quantification of aggregations may not be valid and that mHTT antibody binding is unique to the mouse model and sensitive to changes in inclusion development. PMID:27196694

Neurodegeneration and Vision Loss after Mild Blunt Trauma in the C57Bl/6 and DBA/2J Mouse

PubMed Central

Bricker-Anthony, Courtney; Rex, Tonia S.

2015-01-01

Damage to the eye from blast exposure can occur as a result of the overpressure air-wave (primary injury), flying debris (secondary injury), blunt force trauma (tertiary injury), and/or chemical/thermal burns (quaternary injury). In this study, we investigated damage in the contralateral eye after a blast directed at the ipsilateral eye in the C57Bl/6J and DBA/2J mouse. Assessments of ocular health (gross pathology, electroretinogram recordings, optokinetic tracking, optical coherence tomography and histology) were performed at 3, 7, 14 and 28 days post-trauma. Olfactory epithelium and optic nerves were also examined. Anterior pathologies were more common in the DBA/2J than in the C57Bl/6 and could be prevented with non-medicated viscous eye drops. Visual acuity decreased over time in both strains, but was more rapid and severe in the DBA/2J. Retinal cell death was present in approximately 10% of the retina at 7 and 28 days post-blast in both strains. Approximately 60% of the cell death occurred in photoreceptors. Increased oxidative stress and microglial reactivity was detected in both strains, beginning at 3 days post-injury. However, there was no sign of injury to the olfactory epithelium or optic nerve in either strain. Although our model directs an overpressure air-wave at the left eye in a restrained and otherwise protected mouse, retinal damage was detected in the contralateral eye. The lack of damage to the olfactory epithelium and optic nerve, as well as the different timing of cell death as compared to the blast-exposed eye, suggests that the injuries were due to physical contact between the contralateral eye and the housing chamber of the blast device and not propagation of the blast wave through the head. Thus we describe a model of mild blunt eye trauma. PMID:26148200

Age-related decline in white matter integrity in a mouse model of tauopathy: an in vivo diffusion tensor magnetic resonance imaging study

PubMed Central

Sahara, Naruhiko; Perez, Pablo D.; Lin, Wen-Lang; Dickson, Dennis W.; Ren, Yan; Zeng, Huadong; Lewis, Jada; Febo, Marcelo

2016-01-01

Elevated expression of human hyperphosphorylated tau is associated with neuronal loss and white matter (WM) pathology in Alzheimer’s disease (AD) and related neurodegenerative disorders. Using in vivo diffusion tensor magnetic resonance imaging (DT-MRI) at 11.1 Tesla we measured age-related alterations in WM diffusion anisotropy indices in a mouse model of human tauopathy (rTg4510) and nontransgenic (nonTg) control mice at the age of 2.5, 4.5, and 8 months. Similar to previous DT-MRI studies in AD subjects, 8-month-old rTg4510 mice showed lower fractional anisotropy (FA) values in WM structures than nonTg. The low WM FA in rTg4510 mice was observed in the genu and splenium of the corpus callosum, anterior commissure, fimbria, and internal capsule and was associated with a higher radial diffusivity than nonTg. Interestingly, rTg4510 mice showed lower estimates for the mode of anisotropy than controls at 2.5 months suggesting that changes in this diffusivity metric are detectable at an early stage preceding severe tauopathy. Immunogold electron microscopy partly supports our diffusion tensor imaging findings. At the age of 4 months, rTg4510 mice show axonal tau inclusions and unmyelinated processes. At later ages (12 months and 14 months) we observed inclusions in myelin sheath, axons, and unmyelinated processes, and a “disorganized” pattern of myelinated fiber arrangement with enlarged inter-axonal spaces in rTg4510 but not in nonTg mice. Our data support a role for the progression of tau pathology in reduced WM integrity measured by DT-MRI. Further in vivo DT-MRI studies in the rTg4510 mouse should help better discern the detailed mechanisms of reduced FA and anisotropy mode, and the specific role of tau during neurodegeneration. PMID:24411290

Phenylbutyrate ameliorates cognitive deficit and reduces tau pathology in an Alzheimer's disease mouse model.

PubMed

Ricobaraza, Ana; Cuadrado-Tejedor, Mar; Pérez-Mediavilla, Alberto; Frechilla, Diana; Del Río, Joaquin; García-Osta, Ana

2009-06-01

Chromatin modification through histone acetylation is a molecular pathway involved in the regulation of transcription underlying memory storage. Sodium 4-phenylbutyrate (4-PBA) is a well-known histone deacetylase inhibitor, which increases gene transcription of a number of genes, and also exerts neuroprotective effects. In this study, we report that administration of 4-PBA reversed spatial learning and memory deficits in an established mouse model of Alzheimer's disease (AD) without altering beta-amyloid burden. We also observed that the phosphorylated form of tau was decreased in the AD mouse brain after 4-PBA treatment, an effect probably due to an increase in the inactive form of the glycogen synthase kinase 3beta (GSK3beta). Interestingly, we found a dramatic decrease in brain histone acetylation in the transgenic mice that may reflect an indirect transcriptional repression underlying memory impairment. The administration of 4-PBA restored brain histone acetylation levels and, as a most likely consequence, activated the transcription of synaptic plasticity markers such as the GluR1 subunit of the AMPA receptor, PSD95, and microtubule-associated protein-2. The results suggest that 4-PBA, a drug already approved for clinical use, may provide a novel approach for the treatment of AD.

Intrinsic bursting of AII amacrine cells underlies oscillations in the rd1 mouse retina.

PubMed

Choi, Hannah; Zhang, Lei; Cembrowski, Mark S; Sabottke, Carl F; Markowitz, Alexander L; Butts, Daniel A; Kath, William L; Singer, Joshua H; Riecke, Hermann

2014-09-15

In many forms of retinal degeneration, photoreceptors die but inner retinal circuits remain intact. In the rd1 mouse, an established model for blinding retinal diseases, spontaneous activity in the coupled network of AII amacrine and ON cone bipolar cells leads to rhythmic bursting of ganglion cells. Since such activity could impair retinal and/or cortical responses to restored photoreceptor function, understanding its nature is important for developing treatments of retinal pathologies. Here we analyzed a compartmental model of the wild-type mouse AII amacrine cell to predict that the cell's intrinsic membrane properties, specifically, interacting fast Na and slow, M-type K conductances, would allow its membrane potential to oscillate when light-evoked excitatory synaptic inputs were withdrawn following photoreceptor degeneration. We tested and confirmed this hypothesis experimentally by recording from AIIs in a slice preparation of rd1 retina. Additionally, recordings from ganglion cells in a whole mount preparation of rd1 retina demonstrated that activity in AIIs was propagated unchanged to elicit bursts of action potentials in ganglion cells. We conclude that oscillations are not an emergent property of a degenerated retinal network. Rather, they arise largely from the intrinsic properties of a single retinal interneuron, the AII amacrine cell. Copyright © 2014 the American Physiological Society.

Development and proof-of-concept of three-dimensional lung histology volumes

NASA Astrophysics Data System (ADS)

Mathew, Lindsay; Alabousi, Mostafa; Wheatley, Andrew; Aladl, Usaf; Slipetz, Deborah; Hogg, James C.; Fenster, Aaron; Parraga, Grace

2012-03-01

Most medical imaging is inherently three-dimensional (3D) but for validation of pathological findings, histopathology is commonly used and typically histopathology images are acquired as twodimensional slices with quantitative analysis performed in a single dimension. Histopathology is invasive, labour-intensive, and the analysis cannot be performed in real time, yet it remains the gold standard for the pathological diagnosis and validation of clinical or radiological diagnoses of disease. A major goal worldwide is to improve medical imaging resolution, sensitivity and specificity to better guide therapy and biopsy and to one day delay or replace biopsy. A key limitation however is the lack of tools to directly compare 3D macroscopic imaging acquired in patients with histopathology findings, typically provided in a single dimension (1D) or in two dimensions (2D). To directly address this, we developed methods for 2D histology slice visualization/registration to generate 3D volumes and quantified tissue components in the 3D volume for direct comparison to volumetric micro-CT and clinical CT. We used the elastase-instilled mouse emphysema lung model to evaluate our methods with murine lungs sectioned (5 μm thickness/10 μm gap) and digitized with 2μm in-plane resolution. 3D volumes were generated for wildtype and elastase mouse lung sections after semi-automated registration of all tissue slices. The 1D mean linear intercept (Lm) for wildtype (WT) (47.1 μm +/- 9.8 μm) and elastase mouse lung (64.5 μm +/- 14.0 μm) was significantly different (p<.001). We also generated 3D measurements based on tissue and airspace morphometry from the 3D volumes and all of these were significantly different (p<.0001) when comparing elastase and WT mouse lung. The ratio of the airspace-to-lung volume for the entire lung volume was also significantly and strongly correlated with Lm.

Fluorescent Arc/Arg3.1 indicator mice: a versatile tool to study brain activity changes in vitro and in vivo

PubMed Central

Grinevich, Valery; Kolleker, Alexander; Eliava, Marina; Takada, Naoki; Takuma, Hiroshi; Fukazawa, Yugo; Shigemoto, Ryuichi; Kuhl, Dietmar; Waters, Jack; Seeburg, Peter H.; Osten, Pavel

2014-01-01

The brain-specific immediate early gene Arc/Arg3.1 is induced in response to a variety of stimuli, including sensory and behavior-linked neural activity. Here we report the generation of transgenic mice, termed TgArc/Arg3.1-d4EGFP, expressing a 4-hour half-life form of enhanced green fluorescent protein (d4EGFP) under the control of the Arc/Arg3.1 promoter. We show that d4EGFP-mediated fluorescence faithfully reports Arc/Arg3.1 induction in response to physiological, pathological and pharmacological stimuli, and that this fluorescence permits electrical recording from activated neurons in the live mouse. Moreover, the fluorescent Arc/Arg3.1 indicator revealed activity changes in circumscribed brain areas in distinct modes of stress and in a mouse model of Alzheimer’s disease. These findings identify the TgArc/Arg3.1-d4EGFP mouse as a versatile tool to monitor Arc/Arg3.1 induction in neural circuits, both in vitro and in vivo. PMID:19628007

Cockayne syndrome pathogenesis: lessons from mouse models.

PubMed

Jaarsma, Dick; van der Pluijm, Ingrid; van der Horst, Gijsbertus T J; Hoeijmakers, Jan H J

2013-01-01

Cockayne syndrome (CS) is a rare multisystem disorder characterized by cachectic dwarfism, nervous system abnormalities and features of premature aging. CS symptoms are associated with mutations in 5 genes, CSA, CSB, XPB, XPD and XPG encoding for proteins involved in the transcription-coupled subpathway of nucleotide excision DNA repair (NER). Mutant mice have been generated for all CS-associated genes and provide tools to examine how the cellular defects translate into CS symptoms. Mice deficient for Csa or Csb genetically mimic CS in man, and develop mild CS symptoms including reduced fat tissue, photoreceptor cell loss, and mild, but characteristic, nervous system pathology. These mild CS models are converted into severe CS models with short life span, progressive nervous system degeneration and cachectic dwarfism after simultaneous complete inactivation of global genome NER. A spectrum of mild-to-severe CS-like symptoms occurs in Xpb, Xpd, and Xpg mice that genetically mimic patients with a disorder that combines CS symptoms with another NER syndrome, xeroderma pigmentosum. In conclusion, CS mouse models mice develop a range of CS phenotypes and open promising perspectives for testing interventional approaches. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Variable phenotypic expressivity in inbred retinal degeneration mouse lines: A comparative study of C3H/HeOu and FVB/N rd1 mice.

PubMed

van Wyk, Michiel; Schneider, Sabine; Kleinlogel, Sonja

2015-01-01

Recent advances in optogenetics and gene therapy have led to promising new treatment strategies for blindness caused by retinal photoreceptor loss. Preclinical studies often rely on the retinal degeneration 1 (rd1 or Pde6b(rd1)) retinitis pigmentosa (RP) mouse model. The rd1 founder mutation is present in more than 100 actively used mouse lines. Since secondary genetic traits are well-known to modify the phenotypic progression of photoreceptor degeneration in animal models and human patients with RP, negligence of the genetic background in the rd1 mouse model is unwarranted. Moreover, the success of various potential therapies, including optogenetic gene therapy and prosthetic implants, depends on the progress of retinal degeneration, which might differ between rd1 mice. To examine the prospect of phenotypic expressivity in the rd1 mouse model, we compared the progress of retinal degeneration in two common rd1 lines, C3H/HeOu and FVB/N. We followed retinal degeneration over 24 weeks in FVB/N, C3H/HeOu, and congenic Pde6b(+) seeing mouse lines, using a range of experimental techniques including extracellular recordings from retinal ganglion cells, PCR quantification of cone opsin and Pde6b transcripts, in vivo flash electroretinogram (ERG), and behavioral optokinetic reflex (OKR) recordings. We demonstrated a substantial difference in the speed of retinal degeneration and accompanying loss of visual function between the two rd1 lines. Photoreceptor degeneration and loss of vision were faster with an earlier onset in the FVB/N mice compared to C3H/HeOu mice, whereas the performance of the Pde6b(+) mice did not differ significantly in any of the tests. By postnatal week 4, the FVB/N mice expressed significantly less cone opsin and Pde6b mRNA and had neither ERG nor OKR responses. At 12 weeks of age, the retinal ganglion cells of the FVB/N mice had lost all light responses. In contrast, 4-week-old C3H/HeOu mice still had ERG and OKR responses, and we still recorded light responses from C3H/HeOu retinal ganglion cells until the age of 24 weeks. These results show that genetic background plays an important role in the rd1 mouse pathology. Analogous to human RP, the mouse genetic background strongly influences the rd1 phenotype. Thus, different rd1 mouse lines may follow different timelines of retinal degeneration, making exact knowledge of genetic background imperative in all studies that use rd1 models.

Identification of age- and disease-related alterations in circulating miRNAs in a mouse model of Alzheimer's disease

PubMed Central

Garza-Manero, Sylvia; Arias, Clorinda; Bermúdez-Rattoni, Federico; Vaca, Luis; Zepeda, Angélica

2015-01-01

Alzheimer's disease (AD) is a neurodegenerative disorder characterized clinically by the progressive decline of memory and cognition. Histopathologically, two main hallmarks have been identified in AD: amyloid-β peptide extracellular neuritic plaques and neurofibrillary tangles formed by posttranslational modified tau protein. A definitive diagnosis can only be achieved after the post mortem verification of the histological mentioned alterations. Therefore, the development of biomarkers that allow an early diagnosis and/or predict disease progression is imperative. The prospect of a blood-based biomarker is possible with the finding of circulating microRNAs (miRNAs), a class of small non-coding RNAs of 22–25 nucleotides length that regulate mRNA translation rate. miRNAs travel through blood and recent studies performed in potential AD cases suggest the possibility of finding pathology-associated differences in circulating miRNA levels that may serve to assist in early diagnosis of the disease. However, these studies analyzed samples at a single time-point, limiting the use of miRNAs as biomarkers in AD progression. In this study we evaluated miRNA levels in plasma samples at different time-points of the evolution of an AD-like pathology in a transgenic mouse model of the disease (3xTg-AD). We performed multiplex qRT-PCR and compared the plasmatic levels of 84 miRNAs previously associated to central nervous system development and disease. No significant differences were detected between WT and transgenic young mice. However, age-related significant changes in miRNA abundance were observed for both WT and transgenic mice, and some of these were specific for the 3xTg-AD. In agreement, variations in the levels of particular miRNAs were identified between WT and transgenic old mice thus suggesting that the age-dependent evolution of the AD-like pathology, rather than the presence and expression of the transgenes, modifies the circulating miRNA levels in the 3xTg-AD mice. PMID:25745387

Identification of age- and disease-related alterations in circulating miRNAs in a mouse model of Alzheimer's disease.

PubMed

Garza-Manero, Sylvia; Arias, Clorinda; Bermúdez-Rattoni, Federico; Vaca, Luis; Zepeda, Angélica

2015-01-01

Alzheimer's disease (AD) is a neurodegenerative disorder characterized clinically by the progressive decline of memory and cognition. Histopathologically, two main hallmarks have been identified in AD: amyloid-β peptide extracellular neuritic plaques and neurofibrillary tangles formed by posttranslational modified tau protein. A definitive diagnosis can only be achieved after the post mortem verification of the histological mentioned alterations. Therefore, the development of biomarkers that allow an early diagnosis and/or predict disease progression is imperative. The prospect of a blood-based biomarker is possible with the finding of circulating microRNAs (miRNAs), a class of small non-coding RNAs of 22-25 nucleotides length that regulate mRNA translation rate. miRNAs travel through blood and recent studies performed in potential AD cases suggest the possibility of finding pathology-associated differences in circulating miRNA levels that may serve to assist in early diagnosis of the disease. However, these studies analyzed samples at a single time-point, limiting the use of miRNAs as biomarkers in AD progression. In this study we evaluated miRNA levels in plasma samples at different time-points of the evolution of an AD-like pathology in a transgenic mouse model of the disease (3xTg-AD). We performed multiplex qRT-PCR and compared the plasmatic levels of 84 miRNAs previously associated to central nervous system development and disease. No significant differences were detected between WT and transgenic young mice. However, age-related significant changes in miRNA abundance were observed for both WT and transgenic mice, and some of these were specific for the 3xTg-AD. In agreement, variations in the levels of particular miRNAs were identified between WT and transgenic old mice thus suggesting that the age-dependent evolution of the AD-like pathology, rather than the presence and expression of the transgenes, modifies the circulating miRNA levels in the 3xTg-AD mice.

Functional and histopathological identification of the respiratory failure in a DMSXL transgenic mouse model of myotonic dystrophy

PubMed Central

Panaite, Petrica-Adrian; Kuntzer, Thierry; Gourdon, Geneviève; Lobrinus, Johannes Alexander; Barakat-Walter, Ibtissam

2013-01-01

SUMMARY Acute and chronic respiratory failure is one of the major and potentially life-threatening features in individuals with myotonic dystrophy type 1 (DM1). Despite several clinical demonstrations showing respiratory problems in DM1 patients, the mechanisms are still not completely understood. This study was designed to investigate whether the DMSXL transgenic mouse model for DM1 exhibits respiratory disorders and, if so, to identify the pathological changes underlying these respiratory problems. Using pressure plethysmography, we assessed the breathing function in control mice and DMSXL mice generated after large expansions of the CTG repeat in successive generations of DM1 transgenic mice. Statistical analysis of breathing function measurements revealed a significant decrease in the most relevant respiratory parameters in DMSXL mice, indicating impaired respiratory function. Histological and morphometric analysis showed pathological changes in diaphragmatic muscle of DMSXL mice, characterized by an increase in the percentage of type I muscle fibers, the presence of central nuclei, partial denervation of end-plates (EPs) and a significant reduction in their size, shape complexity and density of acetylcholine receptors, all of which reflect a possible breakdown in communication between the diaphragmatic muscles fibers and the nerve terminals. Diaphragm muscle abnormalities were accompanied by an accumulation of mutant DMPK RNA foci in muscle fiber nuclei. Moreover, in DMSXL mice, the unmyelinated phrenic afferents are significantly lower. Also in these mice, significant neuronopathy was not detected in either cervical phrenic motor neurons or brainstem respiratory neurons. Because EPs are involved in the transmission of action potentials and the unmyelinated phrenic afferents exert a modulating influence on the respiratory drive, the pathological alterations affecting these structures might underlie the respiratory impairment detected in DMSXL mice. Understanding mechanisms of respiratory deficiency should guide pharmaceutical and clinical research towards better therapy for the respiratory deficits associated with DM1. PMID:23180777

High-Fat-Diet Intake Enhances Cerebral Amyloid Angiopathy and Cognitive Impairment in a Mouse Model of Alzheimer's Disease, Independently of Metabolic Disorders.

PubMed

Lin, Bowen; Hasegawa, Yu; Takane, Koki; Koibuchi, Nobutaka; Cao, Cheng; Kim-Mitsuyama, Shokei

2016-06-13

The high-fat Western diet is postulated to be associated with the onset and progression of Alzheimer's disease (AD). However, the role of high-fat-diet consumption in AD pathology is unknown. This study was undertaken to examine the role of high-fat-diet intake in AD. 5XFAD mice, a useful mouse model of AD, and control wild-type mice were fed (1) high-fat diet or (2) control diet for 10 weeks. The effects on cerebral AD pathology, cognitive function, and metabolic parameters were compared between each group of mice. High-fat diet significantly enhanced cerebrovascular β-amyloid (Aβ) deposition (P<0.05) and impaired cognitive function (P<0.05) in 5XFAD mice, but not in wild-type mice. High-fat diet enhanced hippocampal oxidative stress (P<0.05) and NADPH oxidase subunits, gp91(phox) (P<0.01) and p22(phox) (P<0.01) in 5XFAD mice, but not in wild-type mice. Furthermore, high-fat diet reduced cerebral occludin (P<0.05) in 5XFAD mice, but not in wild-type mice. Thus, 5XFAD mice exhibited greater susceptibility to high-fat diet than wild-type mice regarding cerebrovascular injury and cognitive impairment. On the other hand, 5XFAD mice fed high-fat diet exhibited much less increase in body weight, white adipose tissue weight, and adipocyte size than their wild-type counterparts. High-fat diet significantly impaired glucose tolerance in wild-type mice but not in 5XFAD mice. Thus, 5XFAD mice had much less susceptibility to high-fat-diet-induced metabolic disorders than wild-type mice. High-fat diet, independently of metabolic disorders, significantly promotes the progression of AD-like pathology through enhancement of cerebral amyloid angiopathy and oxidative stress. © 2016 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.

Comparison of independent screens on differentially vulnerable motor neurons reveals alpha-synuclein as a common modifier in motor neuron diseases

PubMed Central

Kaifer, Kevin A.; Osman, Erkan Y.; Carella, Francesco; Tiberi, Ariana; Ross, Jolill; Pennetta, Giuseppa; Lorson, Christian L.

2017-01-01

The term “motor neuron disease” encompasses a spectrum of disorders in which motor neurons are the primary pathological target. However, in both patients and animal models of these diseases, not all motor neurons are equally vulnerable, in that while some motor neurons are lost very early in disease, others remain comparatively intact, even at late stages. This creates a valuable system to investigate the factors that regulate motor neuron vulnerability. In this study, we aim to use this experimental paradigm to identify potential transcriptional modifiers. We have compared the transcriptome of motor neurons from healthy wild-type mice, which are differentially vulnerable in the childhood motor neuron disease Spinal Muscular Atrophy (SMA), and have identified 910 transcriptional changes. We have compared this data set with published microarray data sets on other differentially vulnerable motor neurons. These neurons were differentially vulnerable in the adult onset motor neuron disease Amyotrophic Lateral Sclerosis (ALS), but the screen was performed on the equivalent population of neurons from neurologically normal human, rat and mouse. This cross species comparison has generated a refined list of differentially expressed genes, including CELF5, Col5a2, PGEMN1, SNCA, Stmn1 and HOXa5, alongside a further enrichment for synaptic and axonal transcripts. As an in vivo validation, we demonstrate that the manipulation of a significant number of these transcripts can modify the neurodegenerative phenotype observed in a Drosophila line carrying an ALS causing mutation. Finally, we demonstrate that vector-mediated expression of alpha-synuclein (SNCA), a transcript decreased in selectively vulnerable motor neurons in all four screens, can extend life span, increase weight and decrease neuromuscular junction pathology in a mouse model of SMA. In summary, we have combined multiple data sets to identify transcripts, which are strong candidates for being phenotypic modifiers, and demonstrated SNCA is a modifier of pathology in motor neuron disease. PMID:28362802

Comparison of independent screens on differentially vulnerable motor neurons reveals alpha-synuclein as a common modifier in motor neuron diseases.

PubMed

Kline, Rachel A; Kaifer, Kevin A; Osman, Erkan Y; Carella, Francesco; Tiberi, Ariana; Ross, Jolill; Pennetta, Giuseppa; Lorson, Christian L; Murray, Lyndsay M

2017-03-01

The term "motor neuron disease" encompasses a spectrum of disorders in which motor neurons are the primary pathological target. However, in both patients and animal models of these diseases, not all motor neurons are equally vulnerable, in that while some motor neurons are lost very early in disease, others remain comparatively intact, even at late stages. This creates a valuable system to investigate the factors that regulate motor neuron vulnerability. In this study, we aim to use this experimental paradigm to identify potential transcriptional modifiers. We have compared the transcriptome of motor neurons from healthy wild-type mice, which are differentially vulnerable in the childhood motor neuron disease Spinal Muscular Atrophy (SMA), and have identified 910 transcriptional changes. We have compared this data set with published microarray data sets on other differentially vulnerable motor neurons. These neurons were differentially vulnerable in the adult onset motor neuron disease Amyotrophic Lateral Sclerosis (ALS), but the screen was performed on the equivalent population of neurons from neurologically normal human, rat and mouse. This cross species comparison has generated a refined list of differentially expressed genes, including CELF5, Col5a2, PGEMN1, SNCA, Stmn1 and HOXa5, alongside a further enrichment for synaptic and axonal transcripts. As an in vivo validation, we demonstrate that the manipulation of a significant number of these transcripts can modify the neurodegenerative phenotype observed in a Drosophila line carrying an ALS causing mutation. Finally, we demonstrate that vector-mediated expression of alpha-synuclein (SNCA), a transcript decreased in selectively vulnerable motor neurons in all four screens, can extend life span, increase weight and decrease neuromuscular junction pathology in a mouse model of SMA. In summary, we have combined multiple data sets to identify transcripts, which are strong candidates for being phenotypic modifiers, and demonstrated SNCA is a modifier of pathology in motor neuron disease.

Isolation of Mouse Primary Gastric Epithelial Cells to Investigate the Mechanisms of Helicobacter pylori Associated Disease.

PubMed

Tran, Le Son; Ferrero, Richard L

2018-01-01

The gastrointestinal epithelium provides the first line of defense against invading pathogens, among which Helicobacter pylori is linked to numerous gastric pathologies, including chronic gastritis and cancer. Primary gastric epithelial cells represent a useful model for the investigation of the underlying molecular and cellular mechanisms involved in these H. pylori associated diseases. In this chapter, we describe a method for the isolation of primary gastric epithelial cells from mice and detection of epithelial cell adhesion molecule (EpCAM) expression in the isolated cells.

GSK-3α is a central regulator of age-related pathologies in mice

PubMed Central

Zhou, Jibin; Freeman, Theresa A.; Ahmad, Firdos; Shang, Xiying; Mangano, Emily; Gao, Erhe; Farber, John; Wang, Yajing; Ma, Xin-Liang; Woodgett, James; Vagnozzi, Ronald J.; Lal, Hind; Force, Thomas

2013-01-01

Aging is regulated by conserved signaling pathways. The glycogen synthase kinase-3 (GSK-3) family of serine/threonine kinases regulates several of these pathways, but the role of GSK-3 in aging is unknown. Herein, we demonstrate premature death and acceleration of age-related pathologies in the Gsk3a global KO mouse. KO mice developed cardiac hypertrophy and contractile dysfunction as well as sarcomere disruption and striking sarcopenia in cardiac and skeletal muscle, a classical finding in aging. We also observed severe vacuolar degeneration of myofibers and large tubular aggregates in skeletal muscle, consistent with impaired clearance of insoluble cellular debris. Other organ systems, including gut, liver, and the skeletal system, also demonstrated age-related pathologies. Mechanistically, we found marked activation of mTORC1 and associated suppression of autophagy markers in KO mice. Loss of GSK-3α, either by pharmacologic inhibition or Gsk3a gene deletion, suppressed autophagy in fibroblasts. mTOR inhibition rescued this effect and reversed the established pathologies in the striated muscle of the KO mouse. Thus, GSK-3α is a critical regulator of mTORC1, autophagy, and aging. In its absence, aging/senescence is accelerated in multiple tissues. Strategies to maintain GSK-3α activity and/or inhibit mTOR in the elderly could retard the appearance of age-related pathologies. PMID:23549082

Targeting CD6 for the treatment of experimental autoimmune uveitis.

PubMed

Zhang, Lingjun; Li, Yan; Qiu, Wen; Bell, Brent A; Dvorina, Nina; Baldwin, William M; Singer, Nora; Kern, Timothy; Caspi, Rachel R; Fox, David A; Lin, Feng

2018-06-01

CD6 is emerging as a new target for treating many pathological conditions in which T cells are integrally involved, but even the latest data from studies of CD6 gene engineered mice were still contradictory. To address this issue, we studied experimental autoimmune uveitis (EAU), a model of autoimmune uveitis, in wild-type (WT) and CD6 knockout (KO) mice. After EAU induction in WT and CD6 KO mice, we evaluated ocular inflammation and compared retinal antigen-specific T-cell responses using scanning laser ophthalmoscopy, spectral-domain optical coherence tomography, histopathology, and T cell recall assays. Uveitogenic T cells from WT and CD6 KO mice were adoptively transferred into WT naïve mice to confirm the impact of CD6 on T cells. In addition, we immunized CD6 KO mice with recombinant CD6 protein to develop mouse anti-mouse CD6 monoclonal antibodies (mAbs) in which functional antibodies exhibiting cross-reactivity with human CD6 were screened and identified for treatment studies. In CD6 KO mice with EAU, we found significantly decreased retinal inflammation and reduced autoreactive T-cell responses, and confirmed the impaired uveitogenic capacity of T cells from these mice in an adoptive transfer experiment. Notably, one of these cross-reactive mAbs significantly ameliorated retinal inflammation in EAU induced by the adoptive transfer of uveitogenic T cells. Together, these data strongly suggest that CD6 plays a previously unknown, but pivotal role in autoimmune uveitis, and may be a promising new treatment target for this blinding disease. In addition, the newly developed mouse anti-mouse/human CD6 mAbs could be valuable tools for testing CD6-targeted therapies in other mouse models of human diseases. Copyright © 2018 Elsevier Ltd. All rights reserved.

Proteomic profiling of brain cortex tissues in a Tau transgenic mouse model of Alzheimer's disease

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

Chang, Seong-Hun; Jung, In-Soo; Han, Gi-Yeon

Highlights: Black-Right-Pointing-Pointer A transgenic mouse model expressing NSE-htau23 was used. Black-Right-Pointing-Pointer 2D-gel electrophoresis to analyze the cortex proteins of transgenic mice was used. Black-Right-Pointing-Pointer Differentially expressed spots in different stages of AD were identified. Black-Right-Pointing-Pointer GSTP1 and CAII were downregulated with the progression of AD. Black-Right-Pointing-Pointer SCRN1 and ATP6VE1 were up regulated and down regulated differentially. -- Abstract: Alzheimer's disease (AD) involves regionalized neuronal death, synaptic loss, and an accumulation of intracellular neurofibrillary tangles and extracellular senile plaques. Although there have been numerous studies on tau proteins and AD in various stages of neurodegenerative disease pathology, the relationship between taumore » and AD is not yet fully understood. A transgenic mouse model expressing neuron-specific enolase (NSE)-controlled human wild-type tau (NSE-htau23), which displays some of the typical Alzheimer-associated pathological features, was used to analyze the brain proteome associated with tau tangle deposition. Two-dimensional electrophoresis was performed to compare the cortex proteins of transgenic mice (6- and 12-month-old) with those of control mice. Differentially expressed spots in different stages of AD were identified with ESI-Q-TOF (electrospray ionization quadruple time-of-flight) mass spectrometry and liquid chromatography/tandem mass spectrometry. Among the identified proteins, glutathione S-transferase P 1 (GSTP1) and carbonic anhydrase II (CAII) were down-regulated with the progression of AD, and secerin-1 (SCRN1) and V-type proton ATPase subunit E 1 (ATP6VE1) were up-regulated only in the early stages, and down-regulated in the later stages of AD. The proteins, which were further confirmed by RT-PCR at the mRNA level and with western blotting at the protein level, are expected to be good candidates as drug targets for AD. The study of up- and down-regulation of proteins during the progression of AD helps to explain the mechanisms associated with neuronal degeneration in AD.« less

Ethanol extract of the tuber of Alisma orientale reduces the pathologic features in a chronic obstructive pulmonary disease mouse model.

PubMed

Kim, Kyun Ha; Song, Hyuk-Hwan; Ahn, Kyung-Seop; Oh, Sei-Ryang; Sadikot, Ruxana T; Joo, Myungsoo

2016-07-21

The tuber of Alismataceae Alisma orientale Juzepzuk has been prescribed as a remedy for treating the diseases associated with body fluid dysfunction such as edema and inflammatory lung diseases. Chronic obstructive pulmonary disease (COPD) is a debilitating, inflammatory lung disease without effective treatment. Along with persistent inflammation, autophagy has been recently reported to contribute to COPD. Here, by employing a murine model, we examined whether the tuber of the plant is effective against COPD MATERIALS AND METHODS: The ethanol extract of the tuber of A. orientale Juzepzuk (EEAO) was fingerprinted by HPLC. For the establishment of COPD lung, mice received single intratracheal (i.t.) spraying of elastase and LPS per week for 2 weeks. After approximated to the dose prescribed typically to patients, EEAO was administered to the lung 2h after each LPS treatment. Morphometric analyses, semi-quantitative RT-PCR, and western blot were performed to evaluate the effects of EEAO on emphysema, inflammation, and autophagy in mouse lungs. The effect of EEAO on autophagy was also assessed by western blot at the cellular level with murine macrophages and human lung epithelial cells. When receiving i.t. elastase and LPS for 2 weeks, mice developed emphysema and inflammation in the lung. EEAO treatment, however, significantly reduced emphysema and inflammatory cell infiltration to the lung with concomitant decrease of the production of pro-inflammatory cytokines including TNF-α, IL-6, and TGF-β, signature cytokines of COPD. Unlike control mice, the lungs of the COPD mice expressed LC3-II, a biomarker for autophagy formation, which was decreased by EEAO treatment. EEAO also lowered the expression of LC3-II in murine macrophage, RAW 264.7, and human lung epithelial cell, BEAS-2B, which was associated with EEAO activating mTOR. EEAO relieved COPD pathologic features in a mouse model, which was associated with suppression of lung inflammation, emphysema, and autophagy. Our results suggest an effectiveness of the tuber of A. orientale in chronic inflammatory lung diseases such as COPD. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Achilles tendons from decorin- and biglycan-null mouse models have inferior mechanical and structural properties predicted by an image-based empirical damage model

PubMed Central

Gordon, J.A.; Freedman, B.R.; Zuskov, A.; Iozzo, R.V.; Birk, D.E.; Soslowsky, L.J.

2015-01-01

Achilles tendons are a common source of pain and injury, and their pathology may originate from aberrant structure function relationships. Small leucine rich proteoglycans (SLRPs) influence mechanical and structural properties in a tendon-specific manner. However, their roles in the Achilles tendon have not been defined. The objective of this study was to evaluate the mechanical and structural differences observed in mouse Achilles tendons lacking class I SLRPs; either decorin or biglycan. In addition, empirical modeling techniques based on mechanical and image-based measures were employed. Achilles tendons from decorin-null (Dcn−/−) and biglycan-null (Bgn−/−) C57BL/6 female mice (N=102) were used. Each tendon underwent a dynamic mechanical testing protocol including simultaneous polarized light image capture to evaluate both structural and mechanical properties of each Achilles tendon. An empirical damage model was adapted for application to genetic variation and for use with image based structural properties to predict tendon dynamic mechanical properties. We found that Achilles tendons lacking decorin and biglycan had inferior mechanical and structural properties that were age dependent; and that simple empirical models, based on previously described damage models, were predictive of Achilles tendon dynamic modulus in both decorin- and biglycan-null mice. PMID:25888014

Achilles tendons from decorin- and biglycan-null mouse models have inferior mechanical and structural properties predicted by an image-based empirical damage model.

PubMed

Gordon, J A; Freedman, B R; Zuskov, A; Iozzo, R V; Birk, D E; Soslowsky, L J

2015-07-16

Achilles tendons are a common source of pain and injury, and their pathology may originate from aberrant structure function relationships. Small leucine rich proteoglycans (SLRPs) influence mechanical and structural properties in a tendon-specific manner. However, their roles in the Achilles tendon have not been defined. The objective of this study was to evaluate the mechanical and structural differences observed in mouse Achilles tendons lacking class I SLRPs; either decorin or biglycan. In addition, empirical modeling techniques based on mechanical and image-based measures were employed. Achilles tendons from decorin-null (Dcn(-/-)) and biglycan-null (Bgn(-/-)) C57BL/6 female mice (N=102) were used. Each tendon underwent a dynamic mechanical testing protocol including simultaneous polarized light image capture to evaluate both structural and mechanical properties of each Achilles tendon. An empirical damage model was adapted for application to genetic variation and for use with image based structural properties to predict tendon dynamic mechanical properties. We found that Achilles tendons lacking decorin and biglycan had inferior mechanical and structural properties that were age dependent; and that simple empirical models, based on previously described damage models, were predictive of Achilles tendon dynamic modulus in both decorin- and biglycan-null mice. Copyright © 2015 Elsevier Ltd. All rights reserved.

Exposure to particulate hexavalent chromium exacerbates allergic asthma pathology

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

Schneider, Brent C.; Department of Pharmacology and Physiology, The George Washington University, Washington, DC 20037; Constant, Stephanie L.

Airborne hexavalent chromate, Cr(VI), has been identified by the Environmental Protection Agency as a possible health threat in urban areas, due to the carcinogenic potential of some of its forms. Particulate chromates are produced in many different industrial settings, with high levels of aerosolized forms historically documented. Along with an increased risk of lung cancer, a high incidence of allergic asthma has been reported in workers exposed to certain inhaled particulate Cr(VI) compounds. However, a direct causal association between Cr(VI) and allergic asthma has not been established. We recently showed that inhaled particulate Cr(VI) induces an innate neutrophilic inflammatory responsemore » in BALB/c mice. In the current studies we investigated how the inflammation induced by inhaled particulate Cr(VI) might alter the pathology of an allergic asthmatic response. We used a well-established mouse model of allergic asthma. Groups of ovalbumin protein (OVA)-primed mice were challenged either with OVA alone, or with a combination of OVA and particulate zinc chromate, and various parameters associated with asthmatic responses were measured. Co-exposure to particulate Cr(VI) and OVA mediated a mixed form of asthma in which both eosinophils and neutrophils are present in airways, tissue pathology is markedly exacerbated, and airway hyperresponsiveness is significantly increased. Taken together these findings suggest that inhalation of particulate forms of Cr(VI) may augment the severity of ongoing allergic asthma, as well as alter its phenotype. Such findings may have implications for asthmatics in settings in which airborne particulate Cr(VI) compounds are present at high levels. -- Highlights: ► Allergic asthma correlated with exposure to certain inhaled particulate chromates. ► Direct causal association between Cr(VI) and allergic asthma not established. ► Cr exacerbated pathology and airway hyperresponsiveness in an OVA-challenged mouse. ► Particulate Cr(VI) may augment severity and alter phenotype of ongoing allergic asthma.« less

Maporal Hantavirus Causes Mild Pathology in Deer Mice (Peromyscus maniculatus).

PubMed

McGuire, Amanda; Miedema, Kaitlyn; Fauver, Joseph R; Rico, Amber; Aboellail, Tawfik; Quackenbush, Sandra L; Hawkinson, Ann; Schountz, Tony

2016-10-18

Rodent-borne hantaviruses can cause two human diseases with many pathological similarities: hantavirus cardiopulmonary syndrome (HCPS) in the western hemisphere and hemorrhagic fever with renal syndrome in the eastern hemisphere. Each virus is hosted by specific reservoir species without conspicuous disease. HCPS-causing hantaviruses require animal biosafety level-4 (ABSL-4) containment, which substantially limits experimental research of interactions between the viruses and their reservoir hosts. Maporal virus (MAPV) is a South American hantavirus not known to cause disease in humans, thus it can be manipulated under ABSL-3 conditions. The aim of this study was to develop an ABSL-3 hantavirus infection model using the deer mouse ( Peromyscus maniculatus ), the natural reservoir host of Sin Nombre virus (SNV), and a virus that is pathogenic in another animal model to examine immune response of a reservoir host species. Deer mice were inoculated with MAPV, and viral RNA was detected in several organs of all deer mice during the 56 day experiment. Infected animals generated both nucleocapsid-specific and neutralizing antibodies. Histopathological lesions were minimal to mild with the peak of the lesions detected at 7-14 days postinfection, mainly in the lungs, heart, and liver. Low to modest levels of cytokine gene expression were detected in spleens and lungs of infected deer mice, and deer mouse primary pulmonary cells generated with endothelial cell growth factors were susceptible to MAPV with viral RNA accumulating in the cellular fraction compared to infected Vero cells. Most features resembled that of SNV infection of deer mice, suggesting this model may be an ABSL-3 surrogate for studying the host response of a New World hantavirus reservoir.