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Sample records for syndrome mouse model

  1. Mouse models of Inherited Cancer Syndromes

    PubMed Central

    Jahid, Sohail; Lipkin, Steven

    2010-01-01

    Animal models of cancer have been instrumental in understanding the progression and therapy for hereditary cancer syndromes. The ability to alter the genome of individual mouse cell types in both constitutive and inducible approaches has led to many novel insights into their human disease counterparts. In this review, conventional, conditional and inducible knockout mouse models of inherited human cancer syndromes are presented and insights from the study of these models are highlighted. PMID:21075289

  2. Mouse models of long QT syndrome

    PubMed Central

    Salama, Guy; London, Barry

    2007-01-01

    Congenital long QT syndrome is a rare inherited condition characterized by prolongation of action potential duration (APD) in cardiac myocytes, prolongation of the QT interval on the surface electrocardiogram (ECG), and an increased risk of syncope and sudden death due to ventricular tachyarrhythmias. Mutations of cardiac ion channel genes that affect repolarization cause the majority of the congenital cases. Despite detailed characterizations of the mutated ion channels at the molecular level, a complete understanding of the mechanisms by which individual mutations may lead to arrhythmias and sudden death requires study of the intact heart and its modulation by the autonomic nervous system. Here, we will review studies of molecularly engineered mice with mutations in the genes (a) known to cause long QT syndrome in humans and (b) specific to cardiac repolarization in the mouse. Our goal is to provide the reader with a comprehensive overview of mouse models with long QT syndrome and to emphasize the advantages and limitations of these models. PMID:17038432

  3. Phenotype profile of a genetic mouse model for Muenke syndrome

    PubMed Central

    Koyama, Eiki; Agochukwu, Nneamaka B.; Bartlett, Scott P.; Muenke, Maximilian

    2014-01-01

    Purpose The Muenke syndrome mutation (FGFR3P250R), which was discovered 15 years ago, represents the single most common craniosynostosis mutation. Muenke syndrome is characterized by coronal suture synostosis, mid-face hypoplasia, subtle limb anomalies, and hearing loss. However, the spectrum of clinical presentation continues to expand. To better understand the pathophysiology of the Muenke syndrome, we present collective findings from several recent studies that have characterized a genetically equivalent mouse model for Muenke syndrome (FgfR3P244R) and compare them with human phenotypes. Conclusions FgfR3P244R mutant mice show premature fusion of facial sutures, premaxillary and/or zygomatic sutures, but rarely the coronal suture. The mice also lack the typical limb phenotype. On the other hand, the mutant mice display maxillary retrusion in association with a shortening of the anterior cranial base and a premature closure of intersphenoidal and spheno-occipital synchondroses, resembling human midface hypoplasia. In addition, sensorineural hearing loss is detected in all FgfR3P244R mutant mice as in the majority of Muenke syndrome patients. It is caused by a defect in the mechanism of cell fate determination in the organ of Corti. The mice also express phenotypes that have not been previously described in humans, such as reduced cortical bone thickness, hypoplastic trabecular bone, and defective temporomandibular joint structure. Therefore, the FgfR3P244R mouse provides an excellent opportunity to study disease mechanisms of some classical phenotypes of Muenke syndrome and to test novel therapeutic strategies. The mouse model can also be further explored to discover previously unreported yet potentially significant phenotypes of Muenke syndrome. PMID:22872265

  4. Mouse models of primary Sjögren’s syndrome

    PubMed Central

    Park, Young-Seok; Gauna, Adrienne E.; Cha, Seunghee

    2015-01-01

    Sjögren’s syndrome (SjS) is a chronic autoimmune disorder characterized by immune cell infiltration and progressive injury to the salivary and lacrimal glands. As a consequence, patients with SjS develop xerostomia (dry mouth) and keratoconjunctivitis sicca (dry eyes). SjS is the third most common rheumatic autoimmune disorder, affecting 4 million Americans with over 90% of patients being female. Current diagnostic criteria for SjS frequently utilize histological examinations of minor salivary glands for immune cell foci, serology for autoantibodies, and dry eye evaluation by corneal or conjunctival staining. SjS can be classified as primary or secondary SjS, depending on whether it occurs alone or in association with other systemic rheumatic conditions, respectively. Clinical manifestations typically become apparent when the disease is relatively advanced in SjS patients, which poses a challenge for early diagnosis and treatment of SjS. Therefore, SjS mouse models, because of their close resemblance to the human SjS, have been extremely valuable to identify early disease markers and to investigate underlying biological and immunological dysregulations. However, it is important to bear in mind that no single mouse model has duplicated all aspects of SjS pathogenesis and clinical features, mainly due to the multifactorial etiology of SjS that includes numerous susceptibility genes and environmental factors. As such, various mouse models have been developed in the field to try to recapitulate SjS. In this review, we focus on recent mouse models of primary SjS and describe them under three categories of spontaneous, genetically engineered, and experimentally induced development of SjS-like disease. In addition, we discuss future perspectives of SjS mouse models highlighting pros and cons of utilizing mouse models and demands for improved models. PMID:25777752

  5. Dissecting Alzheimer disease in Down syndrome using mouse models

    PubMed Central

    Choong, Xun Yu; Tosh, Justin L.; Pulford, Laura J.; Fisher, Elizabeth M. C.

    2015-01-01

    Down syndrome (DS) is a common genetic condition caused by the presence of three copies of chromosome 21 (trisomy 21). This greatly increases the risk of Alzheimer disease (AD), but although virtually all people with DS have AD neuropathology by 40 years of age, not all develop dementia. To dissect the genetic contribution of trisomy 21 to DS phenotypes including those relevant to AD, a range of DS mouse models has been generated which are trisomic for chromosome segments syntenic to human chromosome 21. Here, we consider key characteristics of human AD in DS (AD-DS), and our current state of knowledge on related phenotypes in AD and DS mouse models. We go on to review important features needed in future models of AD-DS, to understand this type of dementia and so highlight pathogenic mechanisms relevant to all populations at risk of AD. PMID:26528151

  6. Modeling fragile X syndrome in the Fmr1 knockout mouse

    PubMed Central

    Kazdoba, Tatiana M.; Leach, Prescott T.; Silverman, Jill L.; Crawley, Jacqueline N.

    2014-01-01

    Summary Fragile X Syndrome (FXS) is a commonly inherited form of intellectual disability and one of the leading genetic causes for autism spectrum disorder. Clinical symptoms of FXS can include impaired cognition, anxiety, hyperactivity, social phobia, and repetitive behaviors. FXS is caused by a CGG repeat mutation which expands a region on the X chromosome containing the FMR1 gene. In FXS, a full mutation (> 200 repeats) leads to hypermethylation of FMR1, an epigenetic mechanism that effectively silences FMR1 gene expression and reduces levels of the FMR1 gene product, fragile X mental retardation protein (FMRP). FMRP is an RNA-binding protein that is important for the regulation of protein expression. In an effort to further understand how loss of FMR1 and FMRP contribute to FXS symptomology, several FXS animal models have been created. The most well characterized rodent model is the Fmr1 knockout (KO) mouse, which lacks FMRP protein due to a disruption in its Fmr1 gene. Here, we review the behavioral phenotyping of the Fmr1 KO mouse to date, and discuss the clinical relevance of this mouse model to the human FXS condition. While much remains to be learned about FXS, the Fmr1 KO mouse is a valuable tool for understanding the repercussions of functional loss of FMRP and assessing the efficacy of pharmacological compounds in ameliorating the molecular and behavioral phenotypes relevant to FXS. PMID:25606362

  7. Otitis media in a mouse model for Down syndrome

    PubMed Central

    Han, Fengchan; Yu, Heping; Zhang, Jiangping; Tian, Cong; Schmidt, Cecilia; Nava, Casey; Davisson, Muriel T; Zheng, Qing Y

    2009-01-01

    The Ts65Dn mouse shares many phenotypic characteristics of human Down syndrome. Here, we report that otitis media, characterized by effusion in the middle ear and hearing loss, was prevalent in Ts65Dn mice. Of the 53 Ts65Dn mice tested, 81.1% had high auditory-evoked brainstem response (ABR) thresholds for at least one of the stimulus frequencies (click, 8 kHz, 16 kHz and 32 kHz), in at least one ear. The ABR thresholds were variable and showed no tendency toward increase with age, from 2 to 7 months of age. Observation of pathology in mice, aged 3–4 months, revealed middle ear effusion in 11 of 15 Ts65Dn mice examined, but only in two of 11 wild-type mice. The effusion in each mouse varied substantially in volume and inflammatory cell content. The middle ear mucosae were generally thickened and goblet cells were distributed with higher density in the epithelium of the middle ear cavity of Ts65Dn mice as compared with those of wild-type controls. Bacteria of pathogenic importance to humans also were identified in the Ts65Dn mice. This is the first report of otitis media in the Ts65Dn mouse as a model characteristic of human Down syndrome. PMID:19765102

  8. A new mouse model of metabolic syndrome and associated complications

    PubMed Central

    Wang, Yun; Zheng, Yue; Nishina, Patsy M; Naggert, Jürgen K.

    2010-01-01

    Metabolic Syndrome (MS) encompasses a clustering of risk factors for cardiovascular disease, including obesity, insulin resistance, and dyslipidemia. We characterized a new mouse model carrying a dominant mutation, C57BL/6J-Nmf15/+ (B6-Nmf15/+), which develops additional complications of MS such as adipose tissue inflammation and cardiomyopathy. A backcross was used to genetically map the Nmf15 locus. Mice were examined in the CLAMS™ animal monitoring system, and dual energy X-ray absorptiometry and blood chemistry analyses were performed. Hypothalamic LepR, SOCS1 and STAT3 phosphorylation were examined. Cardiac function was assessed by Echo- and Electro Cardiography. Adipose tissue inflammation was characterized by in situ hybridization and measurement of Jun kinase activity. The Nmf15 locus mapped to distal mouse chromosome 5 with a LOD score of 13.8. Nmf15 mice developed obesity by 12 weeks of age. Plasma leptin levels were significantly elevated in pre-obese Nmf15 mice at 8 weeks of age and an attenuated STAT3 phosphorylation in the hypothalamus suggests a primary leptin resistance. Adipose tissue from Nmf15 mice showed a remarkable degree of inflammation and macrophage infiltration as indicated by expression of the F4/80 marker and increased phosphorylation of JNK1/2. Lipidosis was observed in tubular epithelial cells and glomeruli of the kidney. Nmf15 mice demonstrate both histological and pathophysiological evidence of cardiomyopathy. The Nmf15 mouse model provides a new entry point into pathways mediating leptin resistance and obesity. It is one of few models that combine many aspects of metabolic syndrome and can be useful for testing new therapeutic approaches for combating obesity complications, particularly cardiomyopathy. PMID:19398498

  9. Prevention of Developmental Delays in a Down Syndrome Mouse Model

    PubMed Central

    Toso, Laura; Cameroni, Irene; Roberson, Robin; Abebe, Daniel; Bissell, Stephanie; Spong, Catherine Y.

    2009-01-01

    Objective To estimate whether prenatal treatment with neuroprotective peptides prevent the developmental delay and the glial deficit in the Ts65Dn mouse model for Down syndrome, and to explore the peptides effects on achievement of normal development. Methods Pregnant Ts65Dn females were randomly assigned to NAPVSIPQ+ SALLRSIPA or control and were treated by investigators blinded to treatment and genotype on gestational days 8–12. Offspring were tested from postnatal day (P) 5 to 21 for motor and sensory milestones with standardized tests by operators blinded to the pup’s treatment and genotype. The pup’s genotype was determined after completion of all tests. Activity-dependent-neurotrophic-factor, glial fibrillary acidic protein, and vasoactive intestinal peptide expression were determined using real time polymerase chain reaction. Results Trisomic (Ts) mice achieved milestones with a significant delay in 4 of 5 motor and sensory milestones. Ts mice that were prenatally exposed to NAPVSIPQ+SALLRSIPA achieved developmental milestones at the same time as the controls in 3 of 4 motor and 1 of 4 sensory milestones (p<0.01). Euploid pups prenatally treated with NAPVSIPQ+SALLRSIPA achieved developmental milestones significantly earlier than the euploid pups prenatally treated with placebo. Activity-dependent-neurotrophic-factor, expression was significantly downregulated in the Ts65Dn brains versus the controls, prenatal treatment with NAPVSIPQ+SALLRSIPA prevented the activity-dependent-neurotrophic-factor, decrease in the Ts65Dn brains, and the expression was not different from the controls. The glial marker glial fibrillary acidic protein demonstrated the known glial deficit in the Ts65Dn mice, and treatment with NAPVSIPQ+SALLRSIPA prevented its downregulation. Lastly, vasoactive intestinal peptide levels were increased in the Ts brains, while treatment with NAPVSIPQ+SALLRSIPA did not prevent its upregulation. Conclusions Prenatal treatment with NAPVSIPQ and

  10. Methylome repatterning in a mouse model of Maternal PKU Syndrome.

    PubMed

    Dobrowolski, S F; Lyons-Weiler, J; Biery, A; Spridik, K; Vockley, G; Kranik, E; Skvorak, K; Sultana, T

    2014-11-01

    Maternal PKU Syndrome (MPKU) is an embryopathy resulting from in utero phenylalanine (PHE) toxicity secondary to maternal phenylalanine hydroxylase deficient phenylketonuria (PKU). Clinical phenotypes in MPKU include mental retardation, microcephaly, in utero growth restriction, and congenital heart defects. Numerous in utero toxic exposures alter DNA methylation in the fetus. The PAH(enu2) mouse is a model of classical PKU while offspring born of hyperphenylalaninemic dams model MPKU. We investigated offspring of PAH(enu2) dams to determine if altered patterns of DNA methylation occurred in response to in utero PHE exposure. As neurologic deficit is the most prominent MPKU phenotype, methylome patterns were assessed in brain tissue using methylated DNA immunoprecipitation and paired-end sequencing. Brain tissues were assessed in E18.5-19 fetuses of PHE unrestricted PAH(enu2) dams, PHE restricted PAH(enu2) dams, and heterozygous(wt/enu2) control dams. Extensive methylome repatterning was observed in offspring of hyperphenylalaninemic dams while the offspring of PHE restricted dams displayed attenuated methylome repatterning. Methylation within coding regions was dominated by noncoding RNA genes. Differential methylation of promoters targeted protein coding genes. To assess the impact of methylome repatterning on gene expression, brain tissue in experimental and control animals were queried with microarrays assessing expression of microRNAs and protein coding genes. Altered expression of methylome-modified microRNAs and protein coding genes was extensive in offspring of hyperphenylalaninemic dams while minimal changes were observed in offspring of PHE restricted dams. Several genes displaying significantly reduced expression have roles in neurological function or genetic disease with neurological phenotypes. These data indicate in utero PHE toxicity alters DNA methylation in the brain which has downstream impact upon gene expression. Altered gene expression may

  11. The Use of Mouse Models for Understanding the Biology of Down Syndrome and Aging

    PubMed Central

    Vacano, Guido N.; Duval, Nathan; Patterson, David

    2012-01-01

    Down syndrome is a complex condition caused by trisomy of human chromosome 21. The biology of aging may be different in individuals with Down syndrome; this is not well understood in any organism. Because of its complexity, many aspects of Down syndrome must be studied either in humans or in animal models. Studies in humans are essential but are limited for ethical and practical reasons. Fortunately, genetically altered mice can serve as extremely useful models of Down syndrome, and progress in their production and analysis has been remarkable. Here, we describe various mouse models that have been used to study Down syndrome. We focus on segmental trisomies of mouse chromosome regions syntenic to human chromosome 21, mice in which individual genes have been introduced, or mice in which genes have been silenced by targeted mutagenesis. We selected a limited number of genes for which considerable evidence links them to aspects of Down syndrome, and about which much is known regarding their function. We focused on genes important for brain and cognitive function, and for the altered cancer spectrum seen in individuals with Down syndrome. We conclude with observations on the usefulness of mouse models and speculation on future directions. PMID:22461792

  12. The use of mouse models for understanding the biology of down syndrome and aging.

    PubMed

    Vacano, Guido N; Duval, Nathan; Patterson, David

    2012-01-01

    Down syndrome is a complex condition caused by trisomy of human chromosome 21. The biology of aging may be different in individuals with Down syndrome; this is not well understood in any organism. Because of its complexity, many aspects of Down syndrome must be studied either in humans or in animal models. Studies in humans are essential but are limited for ethical and practical reasons. Fortunately, genetically altered mice can serve as extremely useful models of Down syndrome, and progress in their production and analysis has been remarkable. Here, we describe various mouse models that have been used to study Down syndrome. We focus on segmental trisomies of mouse chromosome regions syntenic to human chromosome 21, mice in which individual genes have been introduced, or mice in which genes have been silenced by targeted mutagenesis. We selected a limited number of genes for which considerable evidence links them to aspects of Down syndrome, and about which much is known regarding their function. We focused on genes important for brain and cognitive function, and for the altered cancer spectrum seen in individuals with Down syndrome. We conclude with observations on the usefulness of mouse models and speculation on future directions. PMID:22461792

  13. Activity-Dependent Changes in MAPK Activation in the Angelman Syndrome Mouse Model

    ERIC Educational Resources Information Center

    Filonova, Irina; Trotter, Justin H.; Banko, Jessica L.; Weeber, Edwin J.

    2014-01-01

    Angelman Syndrome (AS) is a devastating neurological disorder caused by disruption of the maternal "UBE3A" gene. Ube3a protein is identified as an E3 ubiquitin ligase that shows neuron-specific imprinting. Despite extensive research evaluating the localization and basal expression profiles of Ube3a in mouse models, the molecular…

  14. Cognitive and Pharmacological Insights from the Ts65Dn Mouse Model of Down Syndrome

    PubMed Central

    Ruparelia, Aarti; Pearn, Matthew L; Mobley, William C

    2012-01-01

    Down syndrome (DS) is a multi-faceted condition resulting in the most common genetic form of intellectual disability. Mouse models of DS, especially the Ts65Dn model, have been pivotal in furthering our understanding of the genetic, molecular and neurobiological mechanisms that underlie learning and memory impairments in DS. Cognitive and pharmacological insights from the Ts65Dn mouse model have led to remarkable translational progress in the development of therapeutic targets and in the emergence of DS clinical trials. Unravelling the pathogenic role of trisomic genes on human chromosome 21 and the genotype-phenotype relationship still remains a pertinent goal for tackling cognitive deficits in DS. PMID:22658745

  15. Exaggerated NMDA Mediated LTD in a Mouse Model of Down Syndrome and Pharmacological Rescuing by Memantine

    ERIC Educational Resources Information Center

    Scott-McKean, Jonah J.; Costa, Alberto C. S.

    2011-01-01

    The Ts65Dn mouse is the best-studied animal model for Down syndrome. In the experiments described here, NMDA-mediated or mGluR-mediated LTD was induced in the CA1 region of hippocampal slices from Ts65Dn and euploid control mice by bath application of 20 [mu]M NMDA for 3 min and 50 [mu]M DHPG for 5 min, respectively. We found that Ts65Dn mice…

  16. Transcriptional profiling of the postnatal brain of the Ts1Cje mouse model of Down syndrome.

    PubMed

    Tan, Kai-Leng; Ling, King-Hwa; Hewitt, Chelsee A; Cheah, Pike-See; Simpson, Ken; Gordon, Lavinia; Pritchard, Melanie A; Smyth, Gordon K; Thomas, Tim; Scott, Hamish S

    2014-12-01

    The Ts1Cje mouse model of Down syndrome (DS) has partial trisomy of mouse chromosome 16 (MMU16), which is syntenic to human chromosome 21 (HSA21). It develops various neuropathological features demonstrated by DS patients such as reduced cerebellar volume [1] and altered hippocampus-dependent learning and memory [2,3]. To understand the global gene expression effect of the partially triplicated MMU16 segment on mouse brain development, we performed the spatiotemporal transcriptome analysis of Ts1Cje and disomic control cerebral cortex, cerebellum and hippocampus harvested at four developmental time-points: postnatal day (P)1, P15, P30 and P84. Here, we provide a detailed description of the experimental and analysis procedures of the microarray dataset, which has been deposited in the Gene Expression Omnibus (GSE49050) database. PMID:26484118

  17. Histone deacetylase inhibition rescues structural and functional brain deficits in a mouse model of Kabuki syndrome

    PubMed Central

    Bjornsson, Hans T.; Benjamin, Joel S.; Zhang, Li; Weissman, Jacqueline; Gerber, Elizabeth E.; Chen, Yi-Chun; Vaurio, Rebecca G.; Potter, Michelle C.; Hansen, Kasper D.; Dietz, Harry C.

    2015-01-01

    Kabuki syndrome is caused by haploinsufficiency for either of two genes that promote the opening of chromatin. If an imbalance between open and closed chromatin is central to the pathogenesis of Kabuki syndrome, agents that promote chromatin opening might have therapeutic potential. We have characterized a mouse model of Kabuki syndrome with a heterozygous deletion in the gene encoding the lysine-specific methyltransferase 2D (Kmt2d), leading to impairment of methyltransferase function. In vitro reporter alleles demonstrated a reduction in histone 4 acetylation and histone 3 lysine 4 trimethylation (H3K4me3) activity in mouse embryonic fibroblasts from Kmt2d+/βGeo mice. These activities were normalized in response to AR-42, a histone deacetylase inhibitor. In vivo, deficiency of H3K4me3 in the dentate gyrus granule cell layer of Kmt2d+/βGeo mice correlated with reduced neurogenesis and hippocampal memory defects. These abnormalities improved upon postnatal treatment with AR-42. Our work suggests that a reversible deficiency in postnatal neurogenesis underlies intellectual disability in Kabuki syndrome. PMID:25273096

  18. From shape to cells: mouse models reveal mechanisms altering palate development in Apert syndrome

    PubMed Central

    Martínez-Abadías, Neus; Holmes, Greg; Pankratz, Talia; Wang, Yingli; Zhou, Xueyan; Jabs, Ethylin Wang; Richtsmeier, Joan T.

    2013-01-01

    SUMMARY Apert syndrome is a congenital disorder characterized by severe skull malformations and caused by one of two missense mutations, S252W and P253R, on fibroblast growth factor receptor 2 (FGFR2). The molecular bases underlying differential Apert syndrome phenotypes are still poorly understood and it is unclear why cleft palate is more frequent in patients carrying the S252W mutation. Taking advantage of Apert syndrome mouse models, we performed a novel combination of morphometric, histological and immunohistochemical analyses to precisely quantify distinct palatal phenotypes in Fgfr2+/S252W and Fgfr2+/P253R mice. We localized regions of differentially altered FGF signaling and assessed local cell patterns to establish a baseline for understanding the differential effects of these two Fgfr2 mutations. Palatal suture scoring and comparative 3D shape analysis from high resolution μCT images of 120 newborn mouse skulls showed that Fgfr2+/S252W mice display relatively more severe palate dysmorphologies, with contracted and more separated palatal shelves, a greater tendency to fuse the maxillary-palatine sutures and aberrant development of the inter-premaxillary suture. These palatal defects are associated with suture-specific patterns of abnormal cellular proliferation, differentiation and apoptosis. The posterior region of the developing palate emerges as a potential target for therapeutic strategies in clinical management of cleft palate in Apert syndrome patients. PMID:23519026

  19. The Gut Microbiome Is Altered in a Letrozole-Induced Mouse Model of Polycystic Ovary Syndrome

    PubMed Central

    Kelley, Scott T.; Skarra, Danalea V.; Rivera, Alissa J.; Thackray, Varykina G.

    2016-01-01

    Women with polycystic ovary syndrome (PCOS) have reproductive and metabolic abnormalities that result in an increased risk of infertility, diabetes and cardiovascular disease. The large intestine contains a complex community of microorganisms (the gut microbiome) that is dysregulated in humans with obesity and type 2 diabetes. Using a letrozole-induced PCOS mouse model, we demonstrated significant diet-independent changes in the gut microbial community, suggesting that gut microbiome dysbiosis may also occur in PCOS women. Letrozole treatment was associated with a time-dependent shift in the gut microbiome and a substantial reduction in overall species and phylogenetic richness. Letrozole treatment also correlated with significant changes in the abundance of specific Bacteroidetes and Firmicutes previously implicated in other mouse models of metabolic disease in a time-dependent manner. Our results suggest that the hyperandrogenemia observed in PCOS may significantly alter the gut microbiome independently of diet. PMID:26731268

  20. Reelin supplementation recovers synaptic plasticity and cognitive deficits in a mouse model for Angelman syndrome

    PubMed Central

    Hethorn, Whitney R; Ciarlone, Stephanie L; Filonova, Irina; Rogers, Justin T; Aguirre, Daniela; Ramirez, Raquel A; Grieco, Joseph C; Peters, Melinda M; Gulick, Danielle; Anderson, Anne E; L Banko, Jessica; Lussier, April L; Weeber, Edwin J

    2015-01-01

    The Reelin signaling pathway is implicated in processes controlling synaptic plasticity and hippocampus-dependent learning and memory. A single direct in vivo application of Reelin enhances long-term potentiation, increases dendritic spine density and improves associative and spatial learning and memory. Angelman syndrome (AS) is a neurological disorder that presents with an overall defect in synaptic function, including decreased long-term potentiation, reduced dendritic spine density, and deficits in learning and memory, making it an attractive model in which to examine the ability of Reelin to recover synaptic function and cognitive deficits. In this study, we investigated the effects of Reelin administration on synaptic plasticity and cognitive function in a mouse model of AS and demonstrated that bilateral, intraventricular injections of Reelin recover synaptic function and corresponding hippocampus-dependent associative and spatial learning and memory. Additionally, we describe alteration of the Reelin profile in tissue from both the AS mouse and post-mortem human brain. PMID:25864922

  1. The Gut Microbiome Is Altered in a Letrozole-Induced Mouse Model of Polycystic Ovary Syndrome.

    PubMed

    Kelley, Scott T; Skarra, Danalea V; Rivera, Alissa J; Thackray, Varykina G

    2016-01-01

    Women with polycystic ovary syndrome (PCOS) have reproductive and metabolic abnormalities that result in an increased risk of infertility, diabetes and cardiovascular disease. The large intestine contains a complex community of microorganisms (the gut microbiome) that is dysregulated in humans with obesity and type 2 diabetes. Using a letrozole-induced PCOS mouse model, we demonstrated significant diet-independent changes in the gut microbial community, suggesting that gut microbiome dysbiosis may also occur in PCOS women. Letrozole treatment was associated with a time-dependent shift in the gut microbiome and a substantial reduction in overall species and phylogenetic richness. Letrozole treatment also correlated with significant changes in the abundance of specific Bacteroidetes and Firmicutes previously implicated in other mouse models of metabolic disease in a time-dependent manner. Our results suggest that the hyperandrogenemia observed in PCOS may significantly alter the gut microbiome independently of diet. PMID:26731268

  2. PDE-4 Inhibition Rescues Aberrant Synaptic Plasticity in Drosophila and Mouse Models of Fragile X Syndrome

    PubMed Central

    Choi, Catherine H.; Schoenfeld, Brian P.; Weisz, Eliana D.; Bell, Aaron J.; Chambers, Daniel B.; Hinchey, Joseph; Choi, Richard J.; Hinchey, Paul; Kollaros, Maria; Gertner, Michael J.; Ferrick, Neal J.; Terlizzi, Allison M.; Yohn, Nicole; Koenigsberg, Eric; Liebelt, David A.; Zukin, R. Suzanne; Woo, Newton H.; Tranfaglia, Michael R.; Louneva, Natalia; Arnold, Steven E.; Siegel, Steven J.

    2015-01-01

    Fragile X syndrome (FXS) is the leading cause of both intellectual disability and autism resulting from a single gene mutation. Previously, we characterized cognitive impairments and brain structural defects in a Drosophila model of FXS and demonstrated that these impairments were rescued by treatment with metabotropic glutamate receptor (mGluR) antagonists or lithium. A well-documented biochemical defect observed in fly and mouse FXS models and FXS patients is low cAMP levels. cAMP levels can be regulated by mGluR signaling. Herein, we demonstrate PDE-4 inhibition as a therapeutic strategy to ameliorate memory impairments and brain structural defects in the Drosophila model of fragile X. Furthermore, we examine the effects of PDE-4 inhibition by pharmacologic treatment in the fragile X mouse model. We demonstrate that acute inhibition of PDE-4 by pharmacologic treatment in hippocampal slices rescues the enhanced mGluR-dependent LTD phenotype observed in FXS mice. Additionally, we find that chronic treatment of FXS model mice, in adulthood, also restores the level of mGluR-dependent LTD to that observed in wild-type animals. Translating the findings of successful pharmacologic intervention from the Drosophila model into the mouse model of FXS is an important advance, in that this identifies and validates PDE-4 inhibition as potential therapeutic intervention for the treatment of individuals afflicted with FXS. PMID:25568131

  3. Behavioural characteristics of the Prader-Willi syndrome related biallelic Snord116 mouse model.

    PubMed

    Zieba, Jerzy; Low, Jac Kee; Purtell, Louise; Qi, Yue; Campbell, Lesley; Herzog, Herbert; Karl, Tim

    2015-10-01

    Prader-Willi syndrome (PWS) is the predominant genetic cause of obesity in humans and is associated with several behavioural phenotypes such as altered motoric function, reduced activity, and learning disabilities. It can include mood instability and, in some cases, psychotic episodes. Recently, the Snord116 gene has been associated with the development of PWS, however, it's contribution to the behavioural aspects of the disease are unknown. Here we show that male and female mice lacking Snord116 on both alleles exhibit normal motor behaviours and exploration but do display task-dependent alterations to locomotion and anxiety-related behaviours. Sociability is well developed in Snord116 deficient mice as are social recognition memory, spatial working memory, and fear-associated behaviours. No sex-specific effects were found. In conclusion, the biallelic Snord116 deficiency mouse model exhibits particular endophenotypes with some relevance to PWS, suggesting partial face validity for the syndrome. PMID:26259850

  4. Matriptase initiates epidermal prokallikrein activation and disease onset in a mouse model of Netherton syndrome

    PubMed Central

    Sales, Katiuchia Uzzun; Masedunskas, Andrius; Bey, Alexandra L.; Rasmussen, Amber; Weigert, Roberto; List, Karin; Szabo, Roman; Overbeek, Paul A.; Bugge, Thomas H.

    2010-01-01

    Deficiency in the serine protease inhibitor LEKTI is the etiological origin of Netherton syndrome. The principal morbidities of the disease are stratum corneum detachment and chronic inflammation. We show that the membrane protease, matriptase, initiates Netherton syndrome in a LEKTI-deficient mouse model by premature activation of a pro-kallikrein-related cascade. Auto-activation of pro-inflammatory and stratum corneum detachment-associated pro-kallikrein-related peptidases was either low or undetectable, but they were efficiently activated by matriptase. Ablation of matriptase from LEKTI-deficient mice dampened inflammation, eliminated aberrant protease activity, prevented stratum corneum detachment, and improved epidermal barrier function. The study uncovers a pathogenic matriptase-pro-kallikrein pathway that could be operative in several human skin and inflammatory diseases. PMID:20657595

  5. Dsprul: A spontaneous mouse mutation in Desmoplakin as a model of Carvajal-Huerta Syndrome

    PubMed Central

    Pratt, C. Herbert; Potter, Christopher S.; Fairfield, Heather; Reinholdt, Laura G.; Bergstrom, David E.; Harris, Belinda S.; Greenstein, Ian; Dadras, Soheil S.; Liang, Bruce T.; Schofield, Paul N.; Sundberg, John P.

    2015-01-01

    Studies of spontaneous mutations in mice have provided valuable disease models and important insights into the mechanisms of human disease. Ruffled (rul) is a new autosomal recessive mutation causing abnormal hair coat in mice. The rul allele arose spontaneously in the RB156Bnr/EiJ inbred mouse strain. In addition to an abnormal coat texture, we found diffuse epidermal blistering, abnormal electrocardiograms (ECGs), and ventricular fibrosis in mutant animals. Using high-throughput sequencing (HTS) we found a frameshift mutation at 38,288,978 bp of chromosome 13 in the desmoplakin gene (Dsp). The predicted mutant protein is truncated at the c-terminus and missing the majority of the plakin repeat domain. The phenotypes found in Dsprul mice closely model a rare human disorder, Carvajal-Huerta Syndrome. Carvajal-Huerta Syndrome (CHS) is a rare cardiocutaneous disorder that presents in humans with woolly hair, palmoplantar keratoderma and ventricular cardiomyopathy. CHS results from an autosomal recessive mutation on the 3′ end of Desmoplakin (DSP) truncating the full length protein. The Dsprul mouse provides a new model to investigate the pathogenesis of CHS, as well as the underlying basic biology of the adhesion molecules coded by the desmosomal genes. PMID:25659760

  6. The Time Course of Deafness and Retinal Degeneration in a Kunming Mouse Model for Usher Syndrome.

    PubMed

    Yao, Lu; Zhang, Lei; Qi, Lin-Song; Liu, Wei; An, Jing; Wang, Bin; Xue, Jun-Hui; Zhang, Zuo-Ming

    2016-01-01

    Usher syndrome is a group of autosomal recessive diseases characterized by congenital deafness and retinitis pigmentosa. In a mouse model for Usher syndrome, KMush/ush, discovered in our laboratory, we measured the phenotypes, characterized the architecture and morphology of the retina, and quantified the level of expression of pde6b and ush2a between postnatal (P) days 7, and 56. Electroretinograms and auditory brainstem response were used to measure visual and auditory phenotypes. Fundus photography and light microscopy were used to measure the architecture and morphology of the retina. Quantitative real-time PCR was used to measure the expression levels of mRNA. KMush/ush mice had low amplitudes and no obvious waveforms of Electroretinograms after P14 compared with controls. Thresholds of auditory brainstem response in our model were higher than those of controls after P14. By P21, the retinal vessels of KMush/ush mice were attenuated and their optic discs had a waxy pallor. The retinas of KMush/ush mice atrophied and the choroidal vessels were clearly visible. Notably, the architecture of each retinal layer was not different as compared with control mice at P7, while the outer nuclear layer (ONL) and other retinal layers of KMush/ush mice were attenuated significantly between P14 and P21. ONL cells were barely seen in KMush/ush mice at P56. As compared with control mice, the expression of pde6b and ush2a in KMush/ush mice declined significantly after P7. This study is a first step toward characterizing the progression of disease in our mouse model. Future studies using this model may provide insights about the etiology of the disease and the relationships between genotypes and phenotypes providing a valuable resource that could contribute to the foundation of knowledge necessary to develop therapies to prevent the retinal degeneration in patients with Usher Syndrome. PMID:27186975

  7. The Time Course of Deafness and Retinal Degeneration in a Kunming Mouse Model for Usher Syndrome

    PubMed Central

    Liu, Wei; An, Jing; Wang, Bin; Xue, Jun-Hui; Zhang, Zuo-Ming

    2016-01-01

    Usher syndrome is a group of autosomal recessive diseases characterized by congenital deafness and retinitis pigmentosa. In a mouse model for Usher syndrome, KMush/ush, discovered in our laboratory, we measured the phenotypes, characterized the architecture and morphology of the retina, and quantified the level of expression of pde6b and ush2a between postnatal (P) days 7, and 56. Electroretinograms and auditory brainstem response were used to measure visual and auditory phenotypes. Fundus photography and light microscopy were used to measure the architecture and morphology of the retina. Quantitative real-time PCR was used to measure the expression levels of mRNA. KMush/ush mice had low amplitudes and no obvious waveforms of Electroretinograms after P14 compared with controls. Thresholds of auditory brainstem response in our model were higher than those of controls after P14. By P21, the retinal vessels of KMush/ush mice were attenuated and their optic discs had a waxy pallor. The retinas of KMush/ush mice atrophied and the choroidal vessels were clearly visible. Notably, the architecture of each retinal layer was not different as compared with control mice at P7, while the outer nuclear layer (ONL) and other retinal layers of KMush/ush mice were attenuated significantly between P14 and P21. ONL cells were barely seen in KMush/ush mice at P56. As compared with control mice, the expression of pde6b and ush2a in KMush/ush mice declined significantly after P7. This study is a first step toward characterizing the progression of disease in our mouse model. Future studies using this model may provide insights about the etiology of the disease and the relationships between genotypes and phenotypes providing a valuable resource that could contribute to the foundation of knowledge necessary to develop therapies to prevent the retinal degeneration in patients with Usher Syndrome. PMID:27186975

  8. Synaptic Vesicle Recycling Is Unaffected in the Ts65Dn Mouse Model of Down Syndrome

    PubMed Central

    Marland, Jamie R. K.; Smillie, Karen J.; Cousin, Michael A.

    2016-01-01

    Down syndrome (DS) is the most common genetic cause of intellectual disability, and arises from trisomy of human chromosome 21. Accumulating evidence from studies of both DS patient tissue and mouse models has suggested that synaptic dysfunction is a key factor in the disorder. The presence of several genes within the DS trisomy that are either directly or indirectly linked to synaptic vesicle (SV) endocytosis suggested that presynaptic dysfunction could underlie some of these synaptic defects. Therefore we determined whether SV recycling was altered in neurons from the Ts65Dn mouse, the best characterised model of DS to date. We found that SV exocytosis, the size of the SV recycling pool, clathrin-mediated endocytosis, activity-dependent bulk endocytosis and SV generation from bulk endosomes were all unaffected by the presence of the Ts65Dn trisomy. These results were obtained using battery of complementary assays employing genetically-encoded fluorescent reporters of SV cargo trafficking, and fluorescent and morphological assays of fluid-phase uptake in primary neuronal culture. The absence of presynaptic dysfunction in central nerve terminals of the Ts65Dn mouse suggests that future research should focus on the established alterations in excitatory / inhibitory balance as a potential route for future pharmacotherapy. PMID:26808141

  9. Mapping genetic modifiers of survival in a mouse model of Dravet syndrome

    PubMed Central

    Miller, Alison R.; Hawkins, Nicole A.; McCollom, Clint E.; Kearney, Jennifer A.

    2014-01-01

    Epilepsy is a common neurological disorder affecting approximately 1% of the population. Mutations in voltage-gated sodium channels are responsible for several monogenic epilepsy syndromes. More than 800 mutations in the voltage-gated sodium channel SCN1A have been reported in patients with generalized epilepsy with febrile seizures plus and Dravet syndrome. Heterozygous loss-of-function mutations in SCN1A result in Dravet syndrome, a severe infant-onset epileptic encephalopathy characterized by intractable seizures, developmental delays and increased mortality. A common feature of monogenic epilepsies is variable expressivity among individuals with the same mutation, suggesting that genetic modifiers may influence clinical severity. Mice with heterozygous deletion of Scn1a (Scn1a+/−) model a number of Dravet syndrome features, including spontaneous seizures and premature lethality. Phenotype severity in Scn1a+/− mice is strongly dependent on strain background. On the 129S6/SvEvTac strain Scn1a+/− mice exhibit no overt phenotype, while on the (C57BL/6J × 129S6/SvEvTac)F1 strain Scn1a+/− mice exhibit spontaneous seizures and early lethality. To systematically identify loci that influence premature lethality in Scn1a+/− mice, we performed genome scans on reciprocal backcrosses. QTL mapping revealed modifier loci on mouse chromosomes 5, 7, 8 and 11. RNA-seq analysis of strain-dependent gene expression, regulation and coding sequence variation provided a list of potential functional candidate genes at each locus. Identification of modifier genes that influence survival in Scn1a+/− mice will improve our understanding of the pathophysiology of Dravet syndrome and may suggest novel therapeutic strategies for improved treatment of human patients. PMID:24152123

  10. Hypothermic responses to 8-OH-DPAT in the Ts65Dn mouse model of Down syndrome.

    PubMed

    Stasko, Melissa R; Scott-McKean, Jonah J; Costa, Alberto C S

    2006-05-29

    Recently, we have demonstrated that potassium channels containing G-protein-activated potassium channel 2 (GIRK2) subunits play a significant role in hypothermia induced by several neurotransmitter receptor agonists, including the serotonin (5-HT)1A/5-HT7 receptor agonist 8-OH-DPAT [R-(+)-8-hydroxy-2-(di-n-propylamino) tetralin]. The GIRK2 gene is located in human chromosome 21 (its mouse ortholog, Girk2, is in mouse chromosome 16). Down syndrome is produced by the trisomy of chromosome 21. Here, we used quantitative radiotelemetry to investigatehypothermic responses to 8-OH-DPAT in the Down syndrome mouse model Ts65Dn (which carries an extra chromosomal 16 segment containing Girk2). Our results indicate that, in relation to euploid controls, Ts65Dn mice display significantly increased hypothermic responses to 8-OH-DPAT. This finding may be relevant to the understanding of previously reported differences in serotoninergic neurotransmission in persons with Down syndrome. PMID:16708025

  11. Cardiac remodeling in the mouse model of Marfan syndrome develops into two distinctive phenotypes.

    PubMed

    Tae, Hyun-Jin; Petrashevskaya, Natalia; Marshall, Shannon; Krawczyk, Melissa; Talan, Mark

    2016-01-15

    Marfan syndrome (MFS) is a systemic disorder of connective tissue caused by mutations in fibrillin-1. Cardiac dysfunction in MFS has not been characterized halting the development of therapies of cardiac complication in MFS. We aimed to study the age-dependent cardiac remodeling in the mouse model of MFS FbnC1039G+/- mouse [Marfan heterozygous (HT) mouse] and its association with valvular regurgitation. Marfan HT mice of 2-4 mo demonstrated a mild hypertrophic cardiac remodeling with predominant decline of diastolic function and increased transforming growth factor-β canonical (p-SMAD2/3) and noncanonical (p-ERK1/2 and p-p38 MAPK) signaling and upregulation of hypertrophic markers natriuretic peptides atrium natriuretic peptide and brain natriuretic peptide. Among older HT mice (6-14 mo), cardiac remodeling was associated with two distinct phenotypes, manifesting either dilated or constricted left ventricular chamber. Dilatation of left ventricular chamber was accompanied by biochemical evidence of greater mechanical stress, including elevated ERK1/2 and p38 MAPK phosphorylation and higher brain natriuretic peptide expression. The aortic valve regurgitation was registered in 20% of the constricted group and 60% of the dilated group, whereas mitral insufficiency was observed in 40% of the constricted group and 100% of the dilated group. Cardiac dysfunction was not associated with the increase of interstitial fibrosis and nonmyocyte proliferation. In the mouse model fibrillin-1, haploinsufficiency results in the early onset of nonfibrotic hypertrophic cardiac remodeling and dysfunction, independently from valvular abnormalities. MFS heart is vulnerable to stress-induced cardiac dilatation in the face of valvular regurgitation, and stress-activated MAPK signals represent a potential target for cardiac management in MFS. PMID:26566724

  12. Exenatide Is an Effective Antihyperglycaemic Agent in a Mouse Model of Wolfram Syndrome 1.

    PubMed

    Sedman, Tuuli; Rünkorg, Kertu; Krass, Maarja; Luuk, Hendrik; Plaas, Mario; Vasar, Eero; Volke, Vallo

    2016-01-01

    Wolfram syndrome 1 is a very rare monogenic disease resulting in a complex of disorders including diabetes mellitus. Up to now, insulin has been used to treat these patients. Some of the monogenic forms of diabetes respond preferentially to sulphonylurea preparations. The aim of the current study was to elucidate whether exenatide, a GLP-1 receptor agonist, and glipizide, a sulphonylurea, are effective in a mouse model of Wolfram syndrome 1. Wolframin-deficient mice were used to test the effect of insulin secretagogues. Wolframin-deficient mice had nearly normal fasting glucose levels but developed hyperglycaemia after glucose challenge. Exenatide in a dose of 10 μg/kg lowered the blood glucose level in both wild-type and wolframin-deficient mice when administered during a nonfasted state and during the intraperitoneal glucose tolerance test. Glipizide (0.6 or 2 mg/kg) was not able to reduce the glucose level in wolframin-deficient animals. In contrast to other groups, wolframin-deficient mice had a lower insulin-to-glucose ratio during the intraperitoneal glucose tolerance test, indicating impaired insulin secretion. Exenatide increased the insulin-to-glucose ratio irrespective of genotype, demonstrating the ability to correct the impaired insulin secretion caused by wolframin deficiency. We conclude that GLP-1 agonists may have potential in the treatment of Wolfram syndrome-related diabetes. PMID:27069934

  13. Exenatide Is an Effective Antihyperglycaemic Agent in a Mouse Model of Wolfram Syndrome 1

    PubMed Central

    Sedman, Tuuli; Rünkorg, Kertu; Krass, Maarja; Luuk, Hendrik; Plaas, Mario; Vasar, Eero; Volke, Vallo

    2016-01-01

    Wolfram syndrome 1 is a very rare monogenic disease resulting in a complex of disorders including diabetes mellitus. Up to now, insulin has been used to treat these patients. Some of the monogenic forms of diabetes respond preferentially to sulphonylurea preparations. The aim of the current study was to elucidate whether exenatide, a GLP-1 receptor agonist, and glipizide, a sulphonylurea, are effective in a mouse model of Wolfram syndrome 1. Wolframin-deficient mice were used to test the effect of insulin secretagogues. Wolframin-deficient mice had nearly normal fasting glucose levels but developed hyperglycaemia after glucose challenge. Exenatide in a dose of 10 μg/kg lowered the blood glucose level in both wild-type and wolframin-deficient mice when administered during a nonfasted state and during the intraperitoneal glucose tolerance test. Glipizide (0.6 or 2 mg/kg) was not able to reduce the glucose level in wolframin-deficient animals. In contrast to other groups, wolframin-deficient mice had a lower insulin-to-glucose ratio during the intraperitoneal glucose tolerance test, indicating impaired insulin secretion. Exenatide increased the insulin-to-glucose ratio irrespective of genotype, demonstrating the ability to correct the impaired insulin secretion caused by wolframin deficiency. We conclude that GLP-1 agonists may have potential in the treatment of Wolfram syndrome-related diabetes. PMID:27069934

  14. Otitis Media in a New Mouse Model for CHARGE Syndrome with a Deletion in the Chd7 Gene

    PubMed Central

    Tian, Cong; Yu, Heping; Yang, Bin; Han, Fengchan; Zheng, Ye; Bartels, Cynthia F.; Schelling, Deborah; Arnold, James E.; Scacheri, Peter C.; Zheng, Qing Yin

    2012-01-01

    Otitis media is a middle ear disease common in children under three years old. Otitis media can occur in normal individuals with no other symptoms or syndromes, but it is often seen in individuals clinically diagnosed with genetic diseases such as CHARGE syndrome, a complex genetic disease caused by mutation in the Chd7 gene and characterized by multiple birth defects. Although otitis media is common in human CHARGE syndrome patients, it has not been reported in mouse models of CHARGE syndrome. In this study, we report a mouse model with a spontaneous deletion mutation in the Chd7 gene and with chronic otitis media of early onset age accompanied by hearing loss. These mice also exhibit morphological alteration in the Eustachian tubes, dysregulation of epithelial proliferation, and decreased density of middle ear cilia. Gene expression profiling revealed up-regulation of Muc5ac, Muc5b and Tgf-β1 transcripts, the products of which are involved in mucin production and TGF pathway regulation. This is the first mouse model of CHARGE syndrome reported to show otitis media with effusion and it will be valuable for studying the etiology of otitis media and other symptoms in CHARGE syndrome. PMID:22539951

  15. Gene expression signature of cerebellar hypoplasia in a mouse model of Down syndrome during postnatal development

    PubMed Central

    Laffaire, Julien; Rivals, Isabelle; Dauphinot, Luce; Pasteau, Fabien; Wehrle, Rosine; Larrat, Benoit; Vitalis, Tania; Moldrich, Randal X; Rossier, Jean; Sinkus, Ralph; Herault, Yann; Dusart, Isabelle; Potier, Marie-Claude

    2009-01-01

    Background Down syndrome is a chromosomal disorder caused by the presence of three copies of chromosome 21. The mechanisms by which this aneuploidy produces the complex and variable phenotype observed in people with Down syndrome are still under discussion. Recent studies have demonstrated an increased transcript level of the three-copy genes with some dosage compensation or amplification for a subset of them. The impact of this gene dosage effect on the whole transcriptome is still debated and longitudinal studies assessing the variability among samples, tissues and developmental stages are needed. Results We thus designed a large scale gene expression study in mice (the Ts1Cje Down syndrome mouse model) in which we could measure the effects of trisomy 21 on a large number of samples (74 in total) in a tissue that is affected in Down syndrome (the cerebellum) and where we could quantify the defect during postnatal development in order to correlate gene expression changes to the phenotype observed. Statistical analysis of microarray data revealed a major gene dosage effect: for the three-copy genes as well as for a 2 Mb segment from mouse chromosome 12 that we show for the first time as being deleted in the Ts1Cje mice. This gene dosage effect impacts moderately on the expression of euploid genes (2.4 to 7.5% differentially expressed). Only 13 genes were significantly dysregulated in Ts1Cje mice at all four postnatal development stages studied from birth to 10 days after birth, and among them are 6 three-copy genes. The decrease in granule cell proliferation demonstrated in newborn Ts1Cje cerebellum was correlated with a major gene dosage effect on the transcriptome in dissected cerebellar external granule cell layer. Conclusion High throughput gene expression analysis in the cerebellum of a large number of samples of Ts1Cje and euploid mice has revealed a prevailing gene dosage effect on triplicated genes. Moreover using an enriched cell population that is thought

  16. Mouse models of the fragile X premutation and fragile X-associated tremor/ataxia syndrome

    PubMed Central

    2014-01-01

    Carriers of the fragile X premutation (FPM) have CGG trinucleotide repeat expansions of between 55 and 200 in the 5′-UTR of FMR1, compared to a CGG repeat length of between 5 and 54 for the general population. Carriers were once thought to be without symptoms, but it is now recognized that they can develop a variety of early neurological symptoms as well as being at risk for developing the late onset neurodegenerative disorder fragile X-associated tremor/ataxia syndrome (FXTAS). Several mouse models have contributed to our understanding of FPM and FXTAS, and findings from studies using these models are summarized here. This review also discusses how this information is improving our understanding of the molecular and cellular abnormalities that contribute to neurobehavioral features seen in some FPM carriers and in patients with FXTAS. Mouse models show much of the pathology seen in FPM carriers and in individuals with FXTAS, including the presence of elevated levels of Fmr1 mRNA, decreased levels of fragile X mental retardation protein, and ubiquitin-positive intranuclear inclusions. Abnormalities in dendritic spine morphology in several brain regions are associated with neurocognitive deficits in spatial and temporal memory processes, impaired motor performance, and altered anxiety. In vitro studies have identified altered dendritic and synaptic architecture associated with abnormal Ca2+ dynamics and electrical network activity. FPM mice have been particularly useful in understanding the roles of Fmr1 mRNA, fragile X mental retardation protein, and translation of a potentially toxic polyglycine peptide in pathology. Finally, the potential for using these and emerging mouse models for preclinical development of therapies to improve neurological function in FXTAS is considered. PMID:25136376

  17. Hearing Loss in a Mouse Model of 22q11.2 Deletion Syndrome

    PubMed Central

    Fuchs, Jennifer C.; Zinnamon, Fhatarah A.; Taylor, Ruth R.; Ivins, Sarah; Scambler, Peter J.; Forge, Andrew; Tucker, Abigail S.; Linden, Jennifer F.

    2013-01-01

    22q11.2 Deletion Syndrome (22q11DS) arises from an interstitial chromosomal microdeletion encompassing at least 30 genes. This disorder is one of the most significant known cytogenetic risk factors for schizophrenia, and can also cause heart abnormalities, cognitive deficits, hearing difficulties, and a variety of other medical problems. The Df1/+ hemizygous knockout mouse, a model for human 22q11DS, recapitulates many of the deficits observed in the human syndrome including heart defects, impaired memory, and abnormal auditory sensorimotor gating. Here we show that Df1/+ mice, like human 22q11DS patients, have substantial rates of hearing loss arising from chronic middle ear infection. Auditory brainstem response (ABR) measurements revealed significant elevation of click-response thresholds in 48% of Df1/+ mice, often in only one ear. Anatomical and histological analysis of the middle ear demonstrated no gross structural abnormalities, but frequent signs of otitis media (OM, chronic inflammation of the middle ear), including excessive effusion and thickened mucosa. In mice for which both in vivo ABR thresholds and post mortem middle-ear histology were obtained, the severity of signs of OM correlated directly with the level of hearing impairment. These results suggest that abnormal auditory sensorimotor gating previously reported in mouse models of 22q11DS could arise from abnormalities in auditory processing. Furthermore, the findings indicate that Df1/+ mice are an excellent model for increased risk of OM in human 22q11DS patients. Given the frequently monaural nature of OM in Df1/+ mice, these animals could also be a powerful tool for investigating the interplay between genetic and environmental causes of OM. PMID:24244619

  18. Mouse models of Down syndrome: how useful can they be? Comparison of the gene content of human chromosome 21 with orthologous mouse genomic regions.

    PubMed

    Gardiner, Katheleen; Fortna, Andrew; Bechtel, Lawrence; Davisson, Muriel T

    2003-10-30

    With an incidence of approximately 1 in 700 live births, Down syndrome (DS) remains the most common genetic cause of mental retardation. The phenotype is assumed to be due to overexpression of some number of the >300 genes encoded by human chromosome 21. Mouse models, in particular the chromosome 16 segmental trisomies, Ts65Dn and Ts1Cje, are indispensable for DS-related studies of gene-phenotype correlations. Here we compare the updated gene content of the finished sequence of human chromosome 21 (364 genes and putative genes) with the gene content of the homologous mouse genomic regions (291 genes and putative genes) obtained from annotation of the public sector C57Bl/6 draft sequence. Annotated genes fall into one of three classes. First, there are 170 highly conserved, human/mouse orthologues. Second, there are 83 minimally conserved, possible orthologues. Included among the conserved and minimally conserved genes are 31 antisense transcripts. Third, there are species-specific genes: 111 spliced human transcripts show no orthologues in the syntenic mouse regions although 13 have homologous sequences elsewhere in the mouse genomic sequence, and 38 spliced mouse transcripts show no identifiable human orthologues. While these species-specific genes are largely based solely on spliced EST data, a majority can be verified in RNA expression experiments. In addition, preliminary data suggest that many human-specific transcripts may represent a novel class of primate-specific genes. Lastly, updated functional annotation of orthologous genes indicates genes encoding components of several cellular pathways are dispersed throughout the orthologous mouse chromosomal regions and are not completely represented in the Down syndrome segmental mouse models. Together, these data point out the potential for existing mouse models to produce extraneous phenotypes and to fail to produce DS-relevant phenotypes. PMID:14585506

  19. Reversing excitatory GABAAR signaling restores synaptic plasticity and memory in a mouse model of Down syndrome.

    PubMed

    Deidda, Gabriele; Parrini, Martina; Naskar, Shovan; Bozarth, Ignacio F; Contestabile, Andrea; Cancedda, Laura

    2015-04-01

    Down syndrome (DS) is the most frequent genetic cause of intellectual disability, and altered GABAergic transmission through Cl(-)-permeable GABAA receptors (GABAARs) contributes considerably to learning and memory deficits in DS mouse models. However, the efficacy of GABAergic transmission has never been directly assessed in DS. Here GABAAR signaling was found to be excitatory rather than inhibitory, and the reversal potential for GABAAR-driven Cl(-) currents (ECl) was shifted toward more positive potentials in the hippocampi of adult DS mice. Accordingly, hippocampal expression of the cation Cl(-) cotransporter NKCC1 was increased in both trisomic mice and individuals with DS. Notably, NKCC1 inhibition by the FDA-approved drug bumetanide restored ECl, synaptic plasticity and hippocampus-dependent memory in adult DS mice. Our findings demonstrate that GABA is excitatory in adult DS mice and identify a new therapeutic approach for the potential rescue of cognitive disabilities in individuals with DS. PMID:25774849

  20. Hippocampal circuit dysfunction in the Tc1 mouse model of Down syndrome

    PubMed Central

    Popov, V.I.; Kraev, I.; Line, S.J.; Jensen, T.P.; Tedoldi, A.; Cummings, D.M.; Tybulewicz, V.L.J.; Fisher, E.M.C.; Bannerman, D.M.; Randall, A.D.; Brown, J.T.; Edwards, F.A.; Rusakov, D.A.; Stewart, M.G.; Jones, M.W.

    2015-01-01

    Hippocampal pathology is likely to contribute to cognitive disability in Down syndrome (DS), yet the neural network basis of this pathology and its contributions to different facets of cognitive impairment remain unclear. Here, we report dysfunctional connectivity between dentate gyrus (DG) and CA3 networks in the transchromosomic Tc1 mouse model of DS, demonstrating that ultrastructural abnormalities and impaired short-term plasticity at DG-CA3 excitatory synapses culminate in impaired coding of novel spatial information in CA3 and CA1 and disrupted behaviour in vivo. These results highlight the vulnerability of DG-CA3 networks to aberrant human chromosome 21 gene expression, and delineate hippocampal circuit abnormalities likely to contribute to distinct cognitive phenotypes in DS. PMID:26237367

  1. Accelerated renal disease is associated with the development of metabolic syndrome in a glucolipotoxic mouse model

    PubMed Central

    Martínez-García, Cristina; Izquierdo, Adriana; Velagapudi, Vidya; Vivas, Yurena; Velasco, Ismael; Campbell, Mark; Burling, Keith; Cava, Fernando; Ros, Manuel; Orešič, Matej; Vidal-Puig, Antonio; Medina-Gomez, Gema

    2012-01-01

    SUMMARY Individuals with metabolic syndrome are at high risk of developing chronic kidney disease (CKD) through unclear pathogenic mechanisms. Obesity and diabetes are known to induce glucolipotoxic effects in metabolically relevant organs. However, the pathogenic role of glucolipotoxicity in the aetiology of diabetic nephropathy is debated. We generated a murine model, the POKO mouse, obtained by crossing the peroxisome proliferator-activated receptor gamma 2 (PPARγ2) knockout (KO) mouse into a genetically obese ob/ob background. We have previously shown that the POKO mice showed: hyperphagia, insulin resistance, hyperglycaemia and dyslipidaemia as early as 4 weeks of age, and developed a complete loss of normal β-cell function by 16 weeks of age. Metabolic phenotyping of the POKO model has led to investigation of the structural and functional changes in the kidney and changes in blood pressure in these mice. Here we demonstrate that the POKO mouse is a model of renal disease that is accelerated by high levels of glucose and lipid accumulation. Similar to ob/ob mice, at 4 weeks of age these animals exhibited an increased urinary albumin:creatinine ratio and significantly increased blood pressure, but in contrast showed a significant increase in the renal hypertrophy index and an associated increase in p27Kip1 expression compared with their obese littermates. Moreover, at 4 weeks of age POKO mice showed insulin resistance, an alteration of lipid metabolism and glomeruli damage associated with increased transforming growth factor beta (TGFβ) and parathyroid hormone-related protein (PTHrP) expression. At this age, levels of proinflammatory molecules, such as monocyte chemoattractant protein-1 (MCP-1), and fibrotic factors were also increased at the glomerular level compared with levels in ob/ob mice. At 12 weeks of age, renal damage was fully established. These data suggest an accelerated lesion through glucolipotoxic effects in the renal pathogenesis in POKO mice

  2. Tumour angiogenesis is reduced in the Tc1 mouse model of Down's syndrome.

    PubMed

    Reynolds, Louise E; Watson, Alan R; Baker, Marianne; Jones, Tania A; D'Amico, Gabriela; Robinson, Stephen D; Joffre, Carine; Garrido-Urbani, Sarah; Rodriguez-Manzaneque, Juan Carlos; Martino-Echarri, Estefanía; Aurrand-Lions, Michel; Sheer, Denise; Dagna-Bricarelli, Franca; Nizetic, Dean; McCabe, Christopher J; Turnell, Andrew S; Kermorgant, Stephanie; Imhof, Beat A; Adams, Ralf; Fisher, Elizabeth M C; Tybulewicz, Victor L J; Hart, Ian R; Hodivala-Dilke, Kairbaan M

    2010-06-10

    Down's syndrome (DS) is a genetic disorder caused by full or partial trisomy of human chromosome 21 and presents with many clinical phenotypes including a reduced incidence of solid tumours. Recent work with the Ts65Dn model of DS, which has orthologues of about 50% of the genes on chromosome 21 (Hsa21), has indicated that three copies of the ETS2 (ref. 3) or DS candidate region 1 (DSCR1) genes (a previously known suppressor of angiogenesis) is sufficient to inhibit tumour growth. Here we use the Tc1 transchromosomic mouse model of DS to dissect the contribution of extra copies of genes on Hsa21 to tumour angiogenesis. This mouse expresses roughly 81% of Hsa21 genes but not the human DSCR1 region. We transplanted B16F0 and Lewis lung carcinoma tumour cells into Tc1 mice and showed that growth of these tumours was substantially reduced compared with wild-type littermate controls. Furthermore, tumour angiogenesis was significantly repressed in Tc1 mice. In particular, in vitro and in vivo angiogenic responses to vascular endothelial growth factor (VEGF) were inhibited. Examination of the genes on the segment of Hsa21 in Tc1 mice identified putative anti-angiogenic genes (ADAMTS1and ERG) and novel endothelial cell-specific genes, never previously shown to be involved in angiogenesis (JAM-B and PTTG1IP), that, when overexpressed, are responsible for inhibiting angiogenic responses to VEGF. Three copies of these genes within the stromal compartment reduced tumour angiogenesis, explaining the reduced tumour growth in DS. Furthermore, we expect that, in addition to the candidate genes that we show to be involved in the repression of angiogenesis, the Tc1 mouse model of DS will permit the identification of other endothelium-specific anti-angiogenic targets relevant to a broad spectrum of cancer patients. PMID:20535211

  3. Lithium reverses increased rates of cerebral protein synthesis in a mouse model of fragile X syndrome

    PubMed Central

    Liu, Zhong-Hua; Huang, Tianjian; Smith, Carolyn Beebe

    2012-01-01

    Individuals with fragile X syndrome (FXS), an inherited form of cognitive disability, have a wide range of symptoms including hyperactivity, autistic behavior, seizures and learning deficits. FXS is caused by silencing of FMR1 and the consequent absence of fragile X mental retardation protein (FMRP). FMRP is an RNA-binding protein that associates with polyribosomes and negatively regulates translation. In a previous study of a mouse model of FXS (Fmr1 knockout (KO)) we demonstrated that in vivo rates of cerebral protein synthesis (rCPS) were elevated in selective brain regions suggesting that the absence of FMRP in FXS may result in dysregulation of cerebral protein synthesis. Lithium, a drug used clinically to treat bipolar disorder, has been used to improve mood dysregulation in individuals with FXS. We reported previously that in the Fmr1 KO mouse chronic dietary lithium treatment reversed or ameliorated both behavioral and morphological abnormalities. Herein we report that chronic dietary lithium treatment reversed the increased rCPS in Fmr1 KO mice with little effect on wild type mice. We also report our results of analyses of key signaling molecules involved in regulation of mRNA translation. Our analyses indicate that neither effects on the PI3K/Akt nor the MAPK/ERK 1/2 pathway fully account for the effects of lithium treatment on rCPS. Collectively our findings and those from other laboratories on the efficacy of lithium treatment in animal models support further studies in patients with FXS. PMID:22227453

  4. Increased incidence of intermittent hypoxemia in the Ts65Dn mouse model of Down syndrome.

    PubMed

    Das, Devsmita; Medina, Brian; Baktir, Mehmet Akif; Mojabi, Fatemeh S; Fahimi, Atoossa; Ponnusamy, Ravikumar; Salehi, Ahmad

    2015-09-14

    In addition to nervous system, cardiovascular and respiratory systems are primarily affected in Down syndrome (DS). The Ts65Dn mouse model is widely used to recapitulate cognitive dysfunction in DS. While these mice consistently show failure in learning and memory along with functional and structural abnormalities in the hippocampal region, the underlying mechanisms behind cognitive dysfunction remain to be fully elucidated. Convergent evidence implicates chronic episodes of hypoxemia in cognitive dysfunction in people with DS. Using an infra-red detection system to assess oxygen saturation in free-moving mice, we assessed arterial blood oxygenation in both adolescent and adult Ts65Dn mice and found a significant increase in the incidence of hypoxemia in both groups. Notably, the severity of hypoxemia increased during the dark cycle, suggesting a link between hypoxemia and increased motor activity. Postmortem analysis showed significant increase in the expression of mitochondrial Cox4i2, the terminal enzyme of the mitochondrial respiratory chain and oxygen response element. Altogether these data suggest early and chronic occurrence of hypoxemia in the Ts65Dn mouse model of DS, which can contribute to cognitive dysfunction in these mice. PMID:26240993

  5. Triheptanoin reduces seizure susceptibility in a syndrome-specific mouse model of generalized epilepsy.

    PubMed

    Kim, Tae Hwan; Borges, Karin; Petrou, Steven; Reid, Christopher A

    2013-01-01

    Triheptanoin is a triglyceride containing heptanoate, an odd-chained medium fatty acid that is metabolized to produce propionyl-CoA and subsequently C4 intermediates of the citric acid cycle and therefore capable of anaplerosis. These metabolic products are believed to underlie triheptanoin's anticonvulsant effects in rodent seizure models. Here we investigate the anticonvulsive effects of oral triheptanoin in a syndrome-specific genetic mouse model of generalized epilepsy based on the GABA(A)γ2(R43Q) mutation. Mice were fed a diet supplemented with triheptanoin from weaning for three weeks prior to electrocortical recordings. Occurrence and durations of spike and wave discharges (SWDs) were measured. Triheptanoin did not alter body weight or basal blood glucose levels suggesting that it was well tolerated. Triheptanoin supplementation halved the time spent in seizures due to a reduction in both SWD occurrence and duration. An injection of insulin was used to reduce blood glucose, a metabolic stress known to precipitate seizures in the GABA(A)γ2(R43Q) mouse. The reduction in seizure count was also evident following insulin induced hypoglycemia with the triheptanoin treated group having significantly less SWDs than control animals under similar low blood glucose conditions. In summary, triheptanoin may be an effective and well tolerated dietary therapy for generalized epilepsy. PMID:23196212

  6. Transcriptome profiling of white adipose tissue in a mouse model for 15q duplication syndrome.

    PubMed

    Liu, Xiaoxi; Tamada, Kota; Kishimoto, Rui; Okubo, Hiroko; Ise, Satoko; Ohta, Hisashi; Ruf, Sandra; Nakatani, Jin; Kohno, Nobuoki; Spitz, François; Takumi, Toru

    2015-09-01

    Obesity is not only associated with unhealthy lifestyles, but also linked to genetic predisposition. Previously, we generated an autism mouse model (patDp/+) that carries a 6.3 Mb paternal duplication homologous to the human 15q11-q13 locus. Chromosomal abnormalities in this region are known to cause autism spectrum disorder, Prader-Willi syndrome, and Angelman syndrome in humans. We found that, in addition to autistic-like behaviors, patDp/+ mice display late-onset obesity and hypersensitivity to a high-fat diet. These phenotypes are likely to be the results of genetic perturbations since the energy expenditures and food intakes of patDp/+ mice do not significantly differ from those of wild-type mice. Intriguingly, we found that an enlargement of adipose cells precedes the onset of obesity in patDp/+ mice. To understand the underlying molecular networks responsible for this pre-obese phenotype, we performed transcriptome profiling of white adipose tissue from patDp/+ and wild-type mice using microarray. We identified 230 genes as differentially expressed genes. Sfrp5 - a gene whose expression is positively correlated with adipocyte size, was found to be up-regulated, and Fndc5, a potent inducer of brown adipogenesis was identified to be the top down-regulated gene. Subsequent pathway analysis highlighted a set of 35 molecules involved in energy production, lipid metabolism, and small molecule biochemistry as the top candidate biological network responsible for the pre-obese phenotype of patDp/+. The microarray data were deposited in NCBI Gene Expression Omnibus database with accession number GSE58191. Ultimately, our dataset provides novel insights into the molecular mechanism of obesity and demonstrated that patDp/+ is a valuable mouse model for obesity research. PMID:26484295

  7. Transcriptome profiling of white adipose tissue in a mouse model for 15q duplication syndrome

    PubMed Central

    Liu, Xiaoxi; Tamada, Kota; Kishimoto, Rui; Okubo, Hiroko; Ise, Satoko; Ohta, Hisashi; Ruf, Sandra; Nakatani, Jin; Kohno, Nobuoki; Spitz, François; Takumi, Toru

    2015-01-01

    Obesity is not only associated with unhealthy lifestyles, but also linked to genetic predisposition. Previously, we generated an autism mouse model (patDp/+) that carries a 6.3 Mb paternal duplication homologous to the human 15q11–q13 locus. Chromosomal abnormalities in this region are known to cause autism spectrum disorder, Prader–Willi syndrome, and Angelman syndrome in humans. We found that, in addition to autistic-like behaviors, patDp/+ mice display late-onset obesity and hypersensitivity to a high-fat diet. These phenotypes are likely to be the results of genetic perturbations since the energy expenditures and food intakes of patDp/+ mice do not significantly differ from those of wild-type mice. Intriguingly, we found that an enlargement of adipose cells precedes the onset of obesity in patDp/+ mice. To understand the underlying molecular networks responsible for this pre-obese phenotype, we performed transcriptome profiling of white adipose tissue from patDp/+ and wild-type mice using microarray. We identified 230 genes as differentially expressed genes. Sfrp5 — a gene whose expression is positively correlated with adipocyte size, was found to be up-regulated, and Fndc5, a potent inducer of brown adipogenesis was identified to be the top down-regulated gene. Subsequent pathway analysis highlighted a set of 35 molecules involved in energy production, lipid metabolism, and small molecule biochemistry as the top candidate biological network responsible for the pre-obese phenotype of patDp/+. The microarray data were deposited in NCBI Gene Expression Omnibus database with accession number GSE58191. Ultimately, our dataset provides novel insights into the molecular mechanism of obesity and demonstrated that patDp/+ is a valuable mouse model for obesity research. PMID:26484295

  8. Characterization of PTZ-Induced Seizure Susceptibility in a Down Syndrome Mouse Model That Overexpresses CSTB

    PubMed Central

    Brault, Véronique; Martin, Benoît; Costet, Nathalie; Bizot, Jean-Charles; Hérault, Yann

    2011-01-01

    Down syndrome (DS) is a complex genetic syndrome characterized by intellectual disability, dysmorphism and variable additional physiological traits. Current research progress has begun to decipher the neural mechanisms underlying cognitive impairment, leading to new therapeutic perspectives. Pentylenetetrazol (PTZ) has recently been found to have positive effects on learning and memory capacities of a DS mouse model and is foreseen to treat DS patients. But PTZ is also known to be a convulsant drug at higher dose and DS persons are more prone to epileptic seizures than the general population. This raises concerns over what long-term effects of treatment might be in the DS population. The cause of increased propensity for epilepsy in the DS population and which Hsa21 gene(s) are implicated remain unknown. Among Hsa21 candidate genes in epilepsy, CSTB, coding for the cystein protease inhibitor cystatin B, is involved in progressive myoclonus epilepsy and ataxia in both mice and human. Thus we aim to evaluate the effect of an increase in Cstb gene dosage on spontaneous epileptic activity and susceptibility to PTZ-induced seizure. To this end we generated a new mouse model trisomic for Cstb by homologous recombination. We verified that increasing copy number of Cstb from Trisomy (Ts) to Tetrasomy (Tt) was driving overexpression of the gene in the brain, we checked transgenic animals for presence of locomotor activity and electroencephalogram (EEG) abnormalities characteristic of myoclonic epilepsy and we tested if those animals were prone to PTZ-induced seizure. Overall, the results of the analysis shows that an increase in Cstb does not induce any spontaneous epileptic activity and neither increase or decrease the propensity of Ts and Tt mice to myoclonic seizures suggesting that Ctsb dosage should not interfere with PTZ-treatment. PMID:22140471

  9. An optogenetic mouse model of rett syndrome targeting on catecholaminergic neurons.

    PubMed

    Zhang, Shuang; Johnson, Christopher M; Cui, Ningren; Xing, Hao; Zhong, Weiwei; Wu, Yang; Jiang, Chun

    2016-10-01

    Rett syndrome (RTT) is a neurodevelopmental disorder affecting multiple functions, including the norepinephrine (NE) system. In the CNS, NE is produced mostly by neurons in the locus coeruleus (LC), where defects in intrinsic neuronal properties, NE biosynthetic enzymes, neuronal CO2 sensitivity, and synaptic currents have been reported in mouse models of RTT. LC neurons in methyl-CpG-binding protein 2 gene (Mecp2) null mice show a high rate of spontaneous firing, although whether such hyperexcitability might increase or decrease the NE release from synapses is unknown. To activate the NEergic axonal terminals selectively, we generated an optogenetic mouse model of RTT in which NEergic neuronal excitability can be manipulated with light. Using commercially available mouse breeders, we produced a new strain of double-transgenic mice with Mecp2 knockout and channelrhodopsin (ChR) knockin in catecholaminergic neurons. Several RTT-like phenotypes were found in the tyrosine hydroxylase (TH)-ChR-Mecp2(-/Y) mice, including hypoactivity, low body weight, hindlimb clasping, and breathing disorders. In brain slices, optostimulation produced depolarization and an increase in the firing rate of LC neurons from TH-ChR control mice. In TH-ChR control mice, optostimulation of presynaptic NEergic neurons augmented the firing rate of hypoglossal neurons (HNs), which was blocked by the α-adrenoceptor antagonist phentolamine. Such optostimulation of NEergic terminals had almost no effect on HNs from two or three TH-ChR-Mecp2(-/Y) mice, indicating that excessive excitation of presynaptic neurons does not benefit NEergic modulation in mice with Mecp2 disruption. These results also demonstrate the feasibility of generating double-transgenic mice for studies of RTT with commercially available mice, which are inexpensive, labor/time efficient, and promising for cell-specific stimulation. © 2016 Wiley Periodicals, Inc. PMID:27317352

  10. Using Mouse Models to Explore Genotype-Phenotype Relationship in Down Syndrome

    ERIC Educational Resources Information Center

    Salehi, Ahmad; Faizi, Mehrdad; Belichenko, Pavel V.; Mobley, William C.

    2007-01-01

    Down Syndrome (DS) caused by trisomy 21 is characterized by a variety of phenotypes and involves multiple organs. Sequencing of human chromosome 21 (HSA21) and subsequently of its orthologues on mouse chromosome 16 have created an unprecedented opportunity to explore the complex relationship between various DS phenotypes and the extra copy of…

  11. Wild type microglia do not arrest pathology in mouse models of Rett syndrome

    PubMed Central

    Wang, Jieqi; Wegener, Jan Eike; Huang, Teng-Wei; Sripathy, Smitha; De Jesus-Cortes, Hector; Xu, Pin; Tran, Stephanie; Knobbe, Whitney; Leko, Vid; Britt, Jeremiah; Starwalt, Ruth; McDaniel, Latisha; Ward, Chris; Parra, Diana; Newcomb, Benjamin; Lao, Uyen; Flowers, David A.; Cullen, Sean; Jorstad, Nikolas L; Yang, Yue; Glaskova, Lena; Vigneau, Sebastian; Kozlitina, Julia; Reichardt, Sybille D.; Reichardt, Holger M.; Gärtner, Jutta; Bartolomei, Marisa S.; Fang, Min; Loeb, Keith; Keene, C. Dirk; Bernstein, Irwin; Goodell, Margaret; Brat, Daniel J.

    2015-01-01

    Rett syndrome (RTT) is a severe neurodevelopmental disorder caused by mutations in the X chromosomal gene Methyl-CpG-binding Protein 2 (MECP2) (1). RTT treatment so far is symptomatic. Mecp2 disruption in mice phenocopies major features of the syndrome (2) that can be reversed upon re-expression of Mecp2 (3. It has recently been reported that transplantation of wild type (WT) bone marrow (BMT) into lethally irradiated Mecp2tm1.1Jae/y mice prevented neurologic decline and early death by restoring microglial phagocytic activity against apoptotic targets (4). Based on this report, clinical trials of BMT for patients with RTT have been initiated (5). We aimed to replicate and extend the BMT experiments in three different RTT mouse models but found that despite robust microglial engraftment, BMT from WT donors did not rescue early death or ameliorate neurologic deficits. Furthermore, early and specific genetic expression of Mecp2 in microglia did not rescue Mecp2-deficient mice. In conclusion our experiments do not support BMT as therapy for RTT. PMID:25993969

  12. 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

  13. Modeling a model: Mouse genetics, 22q11.2 Deletion Syndrome, and disorders of cortical circuit development.

    PubMed

    Meechan, Daniel W; Maynard, Thomas M; Tucker, Eric S; Fernandez, Alejandra; Karpinski, Beverly A; Rothblat, Lawrence A; LaMantia, Anthony-S

    2015-07-01

    Understanding the developmental etiology of autistic spectrum disorders, attention deficit/hyperactivity disorder and schizophrenia remains a major challenge for establishing new diagnostic and therapeutic approaches to these common, difficult-to-treat diseases that compromise neural circuits in the cerebral cortex. One aspect of this challenge is the breadth and overlap of ASD, ADHD, and SCZ deficits; another is the complexity of mutations associated with each, and a third is the difficulty of analyzing disrupted development in at-risk or affected human fetuses. The identification of distinct genetic syndromes that include behavioral deficits similar to those in ASD, ADHC and SCZ provides a critical starting point for meeting this challenge. We summarize clinical and behavioral impairments in children and adults with one such genetic syndrome, the 22q11.2 Deletion Syndrome, routinely called 22q11DS, caused by micro-deletions of between 1.5 and 3.0 MB on human chromosome 22. Among many syndromic features, including cardiovascular and craniofacial anomalies, 22q11DS patients have a high incidence of brain structural, functional, and behavioral deficits that reflect cerebral cortical dysfunction and fall within the spectrum that defines ASD, ADHD, and SCZ. We show that developmental pathogenesis underlying this apparent genetic "model" syndrome in patients can be defined and analyzed mechanistically using genomically accurate mouse models of the deletion that causes 22q11DS. We conclude that "modeling a model", in this case 22q11DS as a model for idiopathic ASD, ADHD and SCZ, as well as other behavioral disorders like anxiety frequently seen in 22q11DS patients, in genetically engineered mice provides a foundation for understanding the causes and improving diagnosis and therapy for these disorders of cortical circuit development. PMID:25866365

  14. Sclerostin Inhibition Reverses Skeletal Fragility in an Lrp5-Deficient Mouse Model of OPPG Syndrome

    PubMed Central

    Kedlaya, Rajendra; Veera, Shreya; Horan, Daniel J.; Moss, Rachel E.; Ayturk, Ugur M.; Jacobsen, Christina M.; Bowen, Margot E.; Paszty, Chris; Warman, Matthew L.; Robling, Alexander G.

    2014-01-01

    Osteoporosis pseudoglioma syndrome (OPPG) is a rare genetic disease that produces debilitating effects in the skeleton. OPPG is caused by mutations in LRP5, a WNT co-receptor that mediates osteoblast activity. WNT signaling through LRP5, and also through the closely related receptor LRP6, is inhibited by the protein sclerostin (SOST). It is unclear whether OPPG patients might benefit from the anabolic action of sclerostin neutralization therapy (an approach currently being pursued in clinical trials for postmenopausal osteoporosis) in light of their LRP5 deficiency and consequent osteoblast impairment. To assess whether loss of sclerostin is anabolic in OPPG, we measured bone properties in a mouse model of OPPG (Lrp5−/−), a mouse model of sclerosteosis (Sost−/−), and in mice with both genes knocked out (Lrp5−/−;Sost−/−). Lrp5−/−;Sost−/− mice have larger, denser, and stronger bones than do Lrp5−/− mice, indicating that SOST deficiency can improve bone properties via pathways that do not require LRP5. Next, we determined whether the anabolic effects of sclerostin depletion in Lrp5−/− mice are retained in adult mice by treating 17-week-old Lrp5−/− mice with a sclerostin antibody for 3 weeks. Lrp5+/+ and Lrp5−/− mice each exhibited osteoanabolic responses to antibody therapy, as indicated by increased bone mineral density, content, and formation rates. Collectively, our data show that inhibiting sclerostin can improve bone mass whether LRP5 is present or not. In the absence of LRP5, the anabolic effects of SOST depletion can occur via other receptors (such as LRP4/6). Regardless of the mechanism, our results suggest that humans with OPPG might benefit from sclerostin neutralization therapies. PMID:24225945

  15. Genetic Enhancement of Limb Defects in a Mouse Model of Cornelia de Lange Syndrome

    PubMed Central

    LOPEZ-BURKS, MARTHA E.; SANTOS, ROSAYSELA; KAWAUCHI, SHIMAKO; CALOF, ANNE L.; LANDER, ARTHUR D.

    2016-01-01

    Cornelia de Lange Syndrome (CdLS) is characterized by a wide variety of structural and functional abnormalities in almost every organ system of the body. CdLS is now known to be caused by mutations that disrupt the function of the cohesin complex or its regulators, and studies of animal models and cell lines tell us that the effect of these mutations is to produce subtle yet pervasive dysregulation of gene expression. With many hundreds of mostly small gene expression changes occurring in every cell type and tissue, identifying the etiology of any particular birth defect is very challenging. Here we focus on limb abnormalities, which are commonly seen in CdLS. In the limb buds of the Nipbl-haploinsufficient mouse (Nipbl+/− mouse), a model for the most common form of CdLS, modest gene expression changes are observed in several candidate pathways whose disruption is known to cause limb abnormalities, yet the limbs of Nipbl+/− mice develop relatively normally. We hypothesized that further impairment of candidate pathways might produce limb defects similar to those seen in CdLS, and performed genetic experiments to test this. Focusing on Sonic hedgehog (Shh), Bone morphogenetic protein (Bmp), and Hox gene pathways, we show that decreasing Bmp or Hox function (but not Shh function) enhances polydactyly in Nipbl+/− mice, and in some cases produces novel skeletal phenotypes. However, frank limb reductions, as are seen in a subset of individuals with CdLS, do not occur, suggesting that additional signaling and/or gene regulatory pathways are involved in producing such dramatic changes. PMID:27120109

  16. Genetic enhancement of limb defects in a mouse model of Cornelia de Lange syndrome.

    PubMed

    Lopez-Burks, Martha E; Santos, Rosaysela; Kawauchi, Shimako; Calof, Anne L; Lander, Arthur D

    2016-06-01

    Cornelia de Lange Syndrome (CdLS) is characterized by a wide variety of structural and functional abnormalities in almost every organ system of the body. CdLS is now known to be caused by mutations that disrupt the function of the cohesin complex or its regulators, and studies of animal models and cell lines tell us that the effect of these mutations is to produce subtle yet pervasive dysregulation of gene expression. With many hundreds of mostly small gene expression changes occurring in every cell type and tissue, identifying the etiology of any particular birth defect is very challenging. Here we focus on limb abnormalities, which are commonly seen in CdLS. In the limb buds of the Nipbl-haploinsufficient mouse (Nipbl(+/-) mouse), a model for the most common form of CdLS, modest gene expression changes are observed in several candidate pathways whose disruption is known to cause limb abnormalities, yet the limbs of Nipbl(+/-) mice develop relatively normally. We hypothesized that further impairment of candidate pathways might produce limb defects similar to those seen in CdLS, and performed genetic experiments to test this. Focusing on Sonic hedgehog (Shh), Bone morphogenetic protein (Bmp), and Hox gene pathways, we show that decreasing Bmp or Hox function (but not Shh function) enhances polydactyly in Nipbl(+/-) mice, and in some cases produces novel skeletal phenotypes. However, frank limb reductions, as are seen in a subset of individuals with CdLS, do not occur, suggesting that additional signaling and/or gene regulatory pathways are involved in producing such dramatic changes. © 2016 Wiley Periodicals, Inc. PMID:27120109

  17. Digastric Muscle Phenotypes of the Ts65Dn Mouse Model of Down Syndrome

    PubMed Central

    Connor, Nadine P.

    2016-01-01

    Down syndrome is frequently associated with complex difficulties in oromotor development, feeding, and swallowing. However, the muscle phenotypes underlying these deficits are unclear. We tested the hypotheses that the Ts65Dn mouse model of DS has significantly altered myosin heavy chain (MyHC) isoform profiles of the muscles involved in feeding and swallowing, as well as reductions in the speed of these movements during behavioral assays. SDS-PAGE, immunofluorescence, and qRT-PCR were used to assess MyHC isoform expression in pertinent muscles, and functional feeding and swallowing performance were quantified through videofluoroscopy and mastication assays. We found that both the anterior digastric (ADG) and posterior digastric (PDG) muscles in 11-day old and 5–6 week old Ts65Dn groups showed significantly lower MyHC 2b protein levels than in age-matched euploid control groups. In videofluoroscopic and videotape assays used to quantify swallowing and mastication performance, 5–6 week old Ts65Dn and euploid controls showed similar swallow rates, inter-swallow intervals, and mastication rates. In analysis of adults, 10–11 week old Ts65Dn mice revealed significantly less MyHC 2b mRNA expression in the posterior digastric, but not the anterior digastric muscle as compared with euploid controls. Analysis of MyHC 2b protein levels across an adult age range (10–53 weeks of age) revealed lower levels of MyHC 2b protein in the PDG of Ts65Dn than in euploids, but similar levels of MyHC 2b in the ADG. Cumulatively, these results indicate biochemical differences in some, but not all, muscles involved in swallowing and jaw movement in Ts65Dn mice that manifest early in post-natal development, and persist into adulthood. These findings suggest potential utility of this model for future investigations of the mechanisms of oromotor difficulties associated with Down syndrome. PMID:27336944

  18. Digastric Muscle Phenotypes of the Ts65Dn Mouse Model of Down Syndrome.

    PubMed

    Glass, Tiffany J; Connor, Nadine P

    2016-01-01

    Down syndrome is frequently associated with complex difficulties in oromotor development, feeding, and swallowing. However, the muscle phenotypes underlying these deficits are unclear. We tested the hypotheses that the Ts65Dn mouse model of DS has significantly altered myosin heavy chain (MyHC) isoform profiles of the muscles involved in feeding and swallowing, as well as reductions in the speed of these movements during behavioral assays. SDS-PAGE, immunofluorescence, and qRT-PCR were used to assess MyHC isoform expression in pertinent muscles, and functional feeding and swallowing performance were quantified through videofluoroscopy and mastication assays. We found that both the anterior digastric (ADG) and posterior digastric (PDG) muscles in 11-day old and 5-6 week old Ts65Dn groups showed significantly lower MyHC 2b protein levels than in age-matched euploid control groups. In videofluoroscopic and videotape assays used to quantify swallowing and mastication performance, 5-6 week old Ts65Dn and euploid controls showed similar swallow rates, inter-swallow intervals, and mastication rates. In analysis of adults, 10-11 week old Ts65Dn mice revealed significantly less MyHC 2b mRNA expression in the posterior digastric, but not the anterior digastric muscle as compared with euploid controls. Analysis of MyHC 2b protein levels across an adult age range (10-53 weeks of age) revealed lower levels of MyHC 2b protein in the PDG of Ts65Dn than in euploids, but similar levels of MyHC 2b in the ADG. Cumulatively, these results indicate biochemical differences in some, but not all, muscles involved in swallowing and jaw movement in Ts65Dn mice that manifest early in post-natal development, and persist into adulthood. These findings suggest potential utility of this model for future investigations of the mechanisms of oromotor difficulties associated with Down syndrome. PMID:27336944

  19. Pharmacological correction of excitation/inhibition imbalance in Down syndrome mouse models

    PubMed Central

    Souchet, Benoit; Guedj, Fayçal; Penke-Verdier, Zsuza; Daubigney, Fabrice; Duchon, Arnaud; Herault, Yann; Bizot, Jean-Charles; Janel, Nathalie; Créau, Nicole; Delatour, Benoit; Delabar, Jean M.

    2015-01-01

    Cognitive impairment in Down syndrome (DS) has been linked to increased synaptic inhibition. The underlying mechanisms remain unknown, but memory deficits are rescued in DS mouse models by drugs targeting GABA receptors. Similarly, administration of epigallocatechin gallate (EGCG)-containing extracts rescues cognitive phenotypes in Ts65Dn mice, potentially through GABA pathway. Some developmental and cognitive alterations have been traced to increased expression of the serine-threonine kinase DYRK1A on Hsa21. To better understand excitation/inhibition balance in DS, we investigated the consequences of long-term (1-month) treatment with EGCG-containing extracts in adult mBACtgDyrk1a mice that overexpress Dyrk1a. Administration of POL60 rescued components of GABAergic and glutamatergic pathways in cortex and hippocampus but not cerebellum. An intermediate dose (60 mg/kg) of decaffeinated green tea extract (MGTE) acted on components of both GABAergic and glutamatergic pathways and rescued behavioral deficits as demonstrated on the alternating paradigm, but did not rescue protein level of GABA-synthesizing GAD67. These results indicate that excessive synaptic inhibition in people with DS may be attributable, in large part, to increased DYRK1A dosage. Thus, controlling the level of active DYRK1A is a clear issue for DS therapy. This study also defines a panel of synaptic markers for further characterization of DS treatments in murine models. PMID:26539088

  20. A small molecule mitigates hearing loss in a mouse model of Usher syndrome III.

    PubMed

    Alagramam, Kumar N; Gopal, Suhasini R; Geng, Ruishuang; Chen, Daniel H-C; Nemet, Ina; Lee, Richard; Tian, Guilian; Miyagi, Masaru; Malagu, Karine F; Lock, Christopher J; Esmieu, William R K; Owens, Andrew P; Lindsay, Nicola A; Ouwehand, Krista; Albertus, Faywell; Fischer, David F; Bürli, Roland W; MacLeod, Angus M; Harte, William E; Palczewski, Krzysztof; Imanishi, Yoshikazu

    2016-06-01

    Usher syndrome type III (USH3), characterized by progressive deafness, variable balance disorder and blindness, is caused by destabilizing mutations in the gene encoding the clarin-1 (CLRN1) protein. Here we report a new strategy to mitigate hearing loss associated with a common USH3 mutation CLRN1(N48K) that involves cell-based high-throughput screening of small molecules capable of stabilizing CLRN1(N48K), followed by a secondary screening to eliminate general proteasome inhibitors, and finally an iterative process to optimize structure-activity relationships. This resulted in the identification of BioFocus 844 (BF844). To test the efficacy of BF844, we developed a mouse model that mimicked the progressive hearing loss associated with USH3. BF844 effectively attenuated progressive hearing loss and prevented deafness in this model. Because the CLRN1(N48K) mutation causes both hearing and vision loss, BF844 could in principle prevent both sensory deficiencies in patients with USH3. Moreover, the strategy described here could help identify drugs for other protein-destabilizing monogenic disorders. PMID:27110679

  1. Pharmacological correction of excitation/inhibition imbalance in Down syndrome mouse models.

    PubMed

    Souchet, Benoit; Guedj, Fayçal; Penke-Verdier, Zsuza; Daubigney, Fabrice; Duchon, Arnaud; Herault, Yann; Bizot, Jean-Charles; Janel, Nathalie; Créau, Nicole; Delatour, Benoit; Delabar, Jean M

    2015-01-01

    Cognitive impairment in Down syndrome (DS) has been linked to increased synaptic inhibition. The underlying mechanisms remain unknown, but memory deficits are rescued in DS mouse models by drugs targeting GABA receptors. Similarly, administration of epigallocatechin gallate (EGCG)-containing extracts rescues cognitive phenotypes in Ts65Dn mice, potentially through GABA pathway. Some developmental and cognitive alterations have been traced to increased expression of the serine-threonine kinase DYRK1A on Hsa21. To better understand excitation/inhibition balance in DS, we investigated the consequences of long-term (1-month) treatment with EGCG-containing extracts in adult mBACtgDyrk1a mice that overexpress Dyrk1a. Administration of POL60 rescued components of GABAergic and glutamatergic pathways in cortex and hippocampus but not cerebellum. An intermediate dose (60 mg/kg) of decaffeinated green tea extract (MGTE) acted on components of both GABAergic and glutamatergic pathways and rescued behavioral deficits as demonstrated on the alternating paradigm, but did not rescue protein level of GABA-synthesizing GAD67. These results indicate that excessive synaptic inhibition in people with DS may be attributable, in large part, to increased DYRK1A dosage. Thus, controlling the level of active DYRK1A is a clear issue for DS therapy. This study also defines a panel of synaptic markers for further characterization of DS treatments in murine models. PMID:26539088

  2. Genome Integrity in Aging: Human Syndromes, Mouse Models, and Therapeutic Options.

    PubMed

    Vermeij, Wilbert P; Hoeijmakers, Jan H J; Pothof, Joris

    2016-01-01

    Human syndromes and mouse mutants that exhibit accelerated but bona fide aging in multiple organs and tissues have been invaluable for the identification of nine denominators of aging: telomere attrition, genome instability, epigenetic alterations, mitochondrial dysfunction, deregulated nutrient sensing, altered intercellular communication, loss of proteostasis, cellular senescence and adult stem cell exhaustion. However, whether and how these instigators of aging interrelate or whether they have one root cause is currently largely unknown. Rare human progeroid syndromes and corresponding mouse mutants with resolved genetic defects highlight the dominant importance of genome maintenance for aging. A second class of aging-related disorders reveals a cross connection with metabolism. As genome maintenance and metabolism are closely interconnected, they may constitute the main underlying biology of aging. This review focuses on the role of genome stability in aging, its crosstalk with metabolism, and options for nutritional and/or pharmaceutical interventions that delay age-related pathology. PMID:26514200

  3. Modeling a model: Mouse genetics, 22q11.2 Deletion Syndrome, and disorders of cortical circuit development

    PubMed Central

    Meechan, Daniel W.; Maynard, Thomas M.; Fernandez, Alejandra; Karpinski, Beverly A.; Rothblat, Lawrence A.; LaMantia, Anthony S.

    2015-01-01

    Understanding the developmental etiology of autistic spectrum disorders, attention deficit/hyperactivity disorder and schizophrenia remains a major challenge for establishing new diagnostic and therapeutic approaches to these common, difficult-to-treat diseases that compromise neural circuits in the cerebral cortex. One aspect of this challenge is the breadth and overlap of ASD, ADHD, and SCZ deficits; another is the complexity of mutations associated with each, and a third is the difficulty of analyzing disrupted development in at-risk or affected human fetuses. The identification of distinct genetic syndromes that include behavioral deficits similar to those in ASD, ADHC and SCZ provides a critical starting point for meeting this challenge. We summarize clinical and behavioral impairments in children and adults with one such genetic syndrome, the 22q11.2 Deletion Syndrome, routinely called 22q11DS, caused by micro-deletions of between 1.5 and 3.0 MB on human chromosome 22. Among many syndromic features, including cardiovascular and craniofacial anomalies, 22q11DS patients have a high incidence of brain structural, functional, and behavioral deficits that reflect cerebral cortical dysfunction and fall within the spectrum that defines ASD, ADHD, and SCZ. We show that developmental pathogenesis underlying this apparent genetic “model” syndrome in patients can be defined and analyzed mechanistically using genomically accurate mouse models of the deletion that causes 22q11DS. We conclude that “modeling a model”, in this case 22q11DS as a model for idiopathic ASD, ADHD and SCZ, as well as other behavioral disorders like anxiety frequently seen in 22q11DS patients, in genetically engineered mice provides a foundation for understanding the causes and improving diagnosis and therapy for these disorders of cortical circuit development. PMID:25866365

  4. Cellular mechanisms of ventricular arrhythmias in a mouse model of Timothy syndrome (long QT syndrome 8).

    PubMed

    Drum, Benjamin M L; Dixon, Rose E; Yuan, Can; Cheng, Edward P; Santana, Luis F

    2014-01-01

    Ca(2+) flux through l-type CaV1.2 channels shapes the waveform of the ventricular action potential (AP) and is essential for excitation-contraction (EC) coupling. Timothy syndrome (TS) is a disease caused by a gain-of-function mutation in the CaV1.2 channel (CaV1.2-TS) that decreases inactivation of the channel, which increases Ca(2+) influx, prolongs APs, and causes lethal arrhythmias. Although many details of the CaV1.2-TS channels are known, the cellular mechanisms by which they induce arrhythmogenic changes in intracellular Ca(2+) remain unclear. We found that expression of CaV1.2-TS channels increased sarcolemmal Ca(2+) "leak" in resting TS ventricular myocytes. This resulted in higher diastolic [Ca(2+)]i in TS ventricular myocytes compared to WT. Accordingly, TS myocytes had higher sarcoplasmic reticulum (SR) Ca(2+) load and Ca(2+) spark activity, larger amplitude [Ca(2+)]i transients, and augmented frequency of Ca(2+) waves. The large SR Ca(2+) release in TS myocytes had a profound effect on the kinetics of CaV1.2 current in these cells, increasing the rate of inactivation to a high, persistent level. This limited the amount of influx during EC coupling in TS myocytes. The relationship between the level of expression of CaV1.2-TS channels and the probability of Ca(2+) wave occurrence was non-linear, suggesting that even low levels of these channels were sufficient to induce maximal changes in [Ca(2+)]i. Depolarization of WT cardiomyocytes with a TS AP waveform increased, but did not equalize [Ca(2+)]i, compared to depolarization of TS myocytes with the same waveform. We propose that CaV1.2-TS channels increase [Ca(2+)] in the cytosol and the SR, creating a Ca(2+)overloaded state that increases the probability of arrhythmogenic spontaneous SR Ca(2+) release. PMID:24215710

  5. Sleep-like behavior and 24-h rhythm disruption in the Tc1 mouse model of Down syndrome

    PubMed Central

    Heise, I; Fisher, S P; Banks, G T; Wells, S; Peirson, S N; Foster, R G; Nolan, P M

    2015-01-01

    Down syndrome is a common disorder associated with intellectual disability in humans. Among a variety of severe health problems, patients with Down syndrome exhibit disrupted sleep and abnormal 24-h rest/activity patterns. The transchromosomic mouse model of Down syndrome, Tc1, is a trans-species mouse model for Down syndrome, carrying most of human chromosome 21 in addition to the normal complement of mouse chromosomes and expresses many of the phenotypes characteristic of Down syndrome. To date, however, sleep and circadian rhythms have not been characterized in Tc1 mice. Using both circadian wheel-running analysis and video-based sleep scoring, we showed that these mice exhibited fragmented patterns of sleep-like behaviour during the light phase of a 12:12-h light/dark (LD) cycle with an extended period of continuous wakefulness at the beginning of the dark phase. Moreover, an acute light pulse during night-time was less effective in inducing sleep-like behaviour in Tc1 animals than in wild-type controls. In wheel-running analysis, free running in constant light (LL) or constant darkness (DD) showed no changes in the circadian period of Tc1 animals although they did express subtle behavioural differences including a reduction in total distance travelled on the wheel and differences in the acrophase of activity in LD and in DD. Our data confirm that Tc1 mice express sleep-related phenotypes that are comparable with those seen in Down syndrome patients with moderate disruptions in rest/activity patterns and hyperactive episodes, while circadian period under constant lighting conditions is essentially unaffected. PMID:25558895

  6. Increased Skin Tumor Incidence and Keratinocyte Hyper-Proliferation in a Mouse Model of Down Syndrome

    PubMed Central

    Yang, Annan; Currier, Duane; Poitras, Jennifer L.; Reeves, Roger H.

    2016-01-01

    Down syndrome (DS) is a genetic disorder caused by the presence of an extra copy of human chromosome 21 (Hsa21). People with DS display multiple clinical traits as a result of the dosage imbalance of several hundred genes. While many outcomes of trisomy are deleterious, epidemiological studies have shown a significant risk reduction for most solid tumors in DS. Reduced tumor incidence has also been demonstrated in functional studies using trisomic DS mouse models. Therefore, it was interesting to find that Ts1Rhr trisomic mice developed more papillomas than did their euploid littermates in a DMBA-TPA chemical carcinogenesis paradigm. Papillomas in Ts1Rhr mice also proliferated faster. The increased proliferation was likely caused by a stronger response of trisomy to TPA induction. Treatment with TPA caused hyperkeratosis to a greater degree in Ts1Rhr mice than in euploid, reminiscent of hyperkeratosis seen in people with DS. Cultured trisomic keratinocytes also showed increased TPA-induced proliferation compared to euploid controls. These outcomes suggest that altered gene expression in trisomy could elevate a proliferation signalling pathway. Gene expression analysis of cultured keratinocytes revealed upregulation of several trisomic and disomic genes may contribute to this hyperproliferation. The contributions of these genes to hyper-proliferation were further validated in a siRNA knockdown experiment. The unexpected findings reported here add a new aspect to our understanding of tumorigenesis with clinical implications for DS and demonstrates the complexity of the tumor repression phenotype in this frequent condition. PMID:26752700

  7. Experimental parameters affecting the Morris water maze performance of a mouse model of Down syndrome.

    PubMed

    Stasko, Melissa R; Costa, Alberto C S

    2004-09-23

    The Ts65Dn mouse is the most studied and genetically the most complete animal model of Down syndrome (DS) available. These mice display many DS-like features, including performance deficits in different behavioral tasks, motor dysfunction, and age-dependent loss of cholinergic markers in the basal forebrain. At present, the only robust data demonstrating a behavioral deficit potentially associated with learning and memory in Ts65Dn mice less than 6 months old have come from studies that used some variation of the Morris water maze task. However, the specific features of the water maze deficits seen in these animals are still poorly defined. This study is an initial attempt to bridge this knowledge gap. We investigated three major factors potentially influencing the performance of Ts65Dn mice in the water maze: (1) order in which the test is executed; (2) age of the animals; and (3) levels of aversiveness associated with the test. Measurements of plasma corticosterone levels and core body temperature after swimming were also carried out in additional subsets of mice. Overall, we found that the behavioral phenotype of Ts65Dn mice was milder than previously described in the literature. Additionally, Ts65Dn mice were significantly more responsive to potential stressors and more prone to swim-induced hypothermia than euploid control animals. More studies are needed to tease out further the potential effects of confounding factors on the performance of Ts65Dn mice. PMID:15302106

  8. Increased Skin Tumor Incidence and Keratinocyte Hyper-Proliferation in a Mouse Model of Down Syndrome.

    PubMed

    Yang, Annan; Currier, Duane; Poitras, Jennifer L; Reeves, Roger H

    2016-01-01

    Down syndrome (DS) is a genetic disorder caused by the presence of an extra copy of human chromosome 21 (Hsa21). People with DS display multiple clinical traits as a result of the dosage imbalance of several hundred genes. While many outcomes of trisomy are deleterious, epidemiological studies have shown a significant risk reduction for most solid tumors in DS. Reduced tumor incidence has also been demonstrated in functional studies using trisomic DS mouse models. Therefore, it was interesting to find that Ts1Rhr trisomic mice developed more papillomas than did their euploid littermates in a DMBA-TPA chemical carcinogenesis paradigm. Papillomas in Ts1Rhr mice also proliferated faster. The increased proliferation was likely caused by a stronger response of trisomy to TPA induction. Treatment with TPA caused hyperkeratosis to a greater degree in Ts1Rhr mice than in euploid, reminiscent of hyperkeratosis seen in people with DS. Cultured trisomic keratinocytes also showed increased TPA-induced proliferation compared to euploid controls. These outcomes suggest that altered gene expression in trisomy could elevate a proliferation signalling pathway. Gene expression analysis of cultured keratinocytes revealed upregulation of several trisomic and disomic genes may contribute to this hyperproliferation. The contributions of these genes to hyper-proliferation were further validated in a siRNA knockdown experiment. The unexpected findings reported here add a new aspect to our understanding of tumorigenesis with clinical implications for DS and demonstrates the complexity of the tumor repression phenotype in this frequent condition. PMID:26752700

  9. Altered regulation of tau phosphorylation in a mouse model of down syndrome aging

    PubMed Central

    Sheppard, Olivia; Plattner, Florian; Rubin, Anna; Slender, Amy; Linehan, Jacqueline M.; Brandner, Sebastian; Tybulewicz, Victor L.J.; Fisher, Elizabeth M.C.; Wiseman, Frances K.

    2012-01-01

    Down syndrome (DS) results from trisomy of human chromosome 21 (Hsa21) and is associated with an increased risk of Alzheimer's disease (AD). Here, using the unique transchromosomic Tc1 mouse model of DS we investigate the influence of trisomy of Hsa21 on the protein tau, which is hyperphosphorylated in Alzheimer's disease. We show that in old, but not young, Tc1 mice increased phosphorylation of tau occurs at a site suggested to be targeted by the Hsa21 encoded kinase, dual-specificity tyrosine-(Y)-phosphorylation regulated kinase 1A (DYRK1A). We show that DYRK1A is upregulated in young and old Tc1 mice, but that young trisomic mice may be protected from accumulating aberrantly phosphorylated tau. We observe that the key tau kinase, glycogen synthase kinase3-β (GSK-3β) is aberrantly phosphorylated at an inhibitory site in the aged Tc1 brain which may reduce total glycogen synthase kinase3-β activity. It is possible that a similar mechanism may also occur in people with DS. PMID:21843906

  10. Meiotic behavior of aneuploid chromatin in mouse models of Down syndrome

    PubMed Central

    Reinholdt, L. G.; Czechanski, A.; Kamdar, S.; King, B. L.; Sun, F.; Handel, M. A.

    2010-01-01

    Aneuploidy, which leads to unpaired chromosomal axes during meiosis, is frequently accompanied by infertility. We previously showed, using three mouse models of Down syndrome, that it is an extra chromosome, but not extra gene dose, that is associated with male infertility and virtual absence of post-meiotic gem cells. Here we test the hypothesis that aneuploid segments are differentially modified and expressed during meiosis, depending on whether they are present as an extra chromosome or not. In all three models examined, the trisomic region lacks a pairing partner, but in one case, spermatocytes have an extra (and unpaired) chromosome, while the two other models involve translocation of the trisomic region rather than an extra chromosome. An extra unpaired chromosome was always modified by phosphorylation of histone H2AX and lacked RNA PolII. But in the case of trisomic regions attached to a paired chromosome, assembly of these protein modifications was affected by the position of a trisomic region relative to a centromere and the physical extent of the unpaired chromatin. Analysis of gene expression in testes revealed that extra copy number alone was not sufficient for meiotic up-regulation of genes in the trisomic interval. Additionally and unexpectedly, presence of meiotic gene silencing chromatin modifications was not sufficient for down-regulation of genes in unpaired trisomic chromatin. Thus the meiotic chromatin modifications that are cytologically visible are unlikely to be directly involved in sterility versus fertility of DS models. Finally, the presence of an extra, unpaired chromosome, but not the presence of extra (trisomic) genes, caused global deregulation of transcription in spermatocytes. These results reveal mechanisms by which an extra chromosome, but not trisomic gene dose, impact on meiotic progress and infertility. PMID:19639331

  11. Analysis of IgM antibody production and repertoire in a mouse model of Sjögren's syndrome.

    PubMed

    Kramer, Jill M; Holodick, Nichol E; Vizconde, Teresa C; Raman, Indu; Yan, Mei; Li, Quan-Zhen; Gaile, Daniel P; Rothstein, Thomas L

    2016-02-01

    This study tested the hypothesis that B cells from salivary tissue are distinct in terms of proliferative capacity, immunoglobulin M secretion, repertoire, and autoantibody enrichment in Sjögren's syndrome. We sorted purified B cells from the spleen, cervical lymph nodes, and submandibular glands of a primary Sjögren's syndrome mouse model (Id3(-/-)). Enzyme-linked immunospot and proliferation assays were performed with stimulated B cells. We single-cell sorted B cells from the spleen, cervical lymph nodes, and submandibular gland tissue from Sjögren's syndrome mice and sequenced immunoglobulin M heavy-chain variable regions. Finally, autoantigen arrays were performed using immunoglobulin M derived from sera, cervical lymph nodes, spleens, and submandibular gland tissue of Id3(-/-) animals. Results suggest B cells from salivary tissue of Sjögren's syndrome mice are similar to those from secondary immune sites in terms of proliferative and secretory capacity. However, differences in repertoire usage, heavy chain complementarity-determining region 3 length, mutational frequency, and N region addition were observed among B cells derived from submandibular gland, cervical lymph node, and spleen tissue. Moreover, autoantigen array data show immunoglobulin M from salivary B cells have enriched specificity for Ro (Sjögren's syndrome A) and La (Sjögren's syndrome B). All together, these data suggest salivary B cells have unique repertoire characteristics that likely influence autoantigen binding and contribute to Sjögren's syndrome disease in a tissue-specific manner. PMID:26382297

  12. Endurance training ameliorates complex 3 deficiency in a mouse model of Barth syndrome.

    PubMed

    Soustek, Meghan S; Baligand, Celine; Falk, Darin J; Walter, Glenn A; Lewin, Alfred S; Byrne, Barry J

    2015-09-01

    Barth syndrome (BTHS) is an X-linked metabolic disorder that causes cardiomyopathy in infancy and is linked to mutations within the Tafazzin (TAZ) gene. The first mouse model, a TAZ knockdown model (TAZKD), has been generated to further understand the bioenergetics leading to cardiomyopathy. However, the TAZKD model does not show early signs of cardiomyopathy, and cardiac pathophysiology has not been documented until 7-8 months of age. Here we sought to determine the impact of endurance training on the cardiac and skeletal muscle phenotype in young TAZKD mice. TAZKD exercise trained (TAZKD-ET) and control exercise trained (CON-ET) mice underwent a 35-day swimming protocol. Non-trained aged matched TAZKD and CON mice were used as controls. At the end of the protocol, cardiac MRI was used to assess cardiac parameters. Cardiac MRI showed that training resulted in cardiac hypertrophy within both groups and did not result in a decline of ejection fraction. TAZKD mice exhibited a decrease in respiratory complex I, III, and IV enzymatic activity in cardiac tissue compared to control mice; however, training led to an increase in complex III activity in TAZKD-ET mice resulting in similar levels to those of CON-ET mice. (31)P magnetic resonance spectroscopy of the gastrocnemius showed a significantly lowered pH in TAZKD-ET mice post electrical-stimulation compared to CON-ET mice. Endurance training does not accelerate cardiac dysfunction in young TAZKD mice, but results in beneficial physiological effects. Furthermore, our results suggest that a significant drop in intracellular pH levels may contribute to oxidative phosphorylation defects during exercise. PMID:25860817

  13. MDM2 inhibition rescues neurogenic and cognitive deficits in a mouse model of fragile X syndrome.

    PubMed

    Li, Yue; Stockton, Michael E; Bhuiyan, Ismat; Eisinger, Brian E; Gao, Yu; Miller, Jessica L; Bhattacharyya, Anita; Zhao, Xinyu

    2016-04-27

    Fragile X syndrome, the most common form of inherited intellectual disability, is caused by loss of the fragile X mental retardation protein (FMRP). However, the mechanism remains unclear, and effective treatment is lacking. We show that loss of FMRP leads to activation of adult mouse neural stem cells (NSCs) and a subsequent reduction in the production of neurons. We identified the ubiquitin ligase mouse double minute 2 homolog (MDM2) as a target of FMRP. FMRP regulates Mdm2 mRNA stability, and loss of FMRP resulted in elevated MDM2 mRNA and protein. Further, we found that increased MDM2 expression led to reduced P53 expression in adult mouse NSCs, leading to alterations in NSC proliferation and differentiation. Treatment with Nutlin-3, a small molecule undergoing clinical trials for treating cancer, specifically inhibited the interaction of MDM2 with P53, and rescued neurogenic and cognitive deficits in FMRP-deficient mice. Our data reveal a potential regulatory role for FMRP in the balance between adult NSC activation and quiescence, and identify a potential new treatment for fragile X syndrome. PMID:27122614

  14. Acute Radiation Syndrome Severity Score System in Mouse Total-Body Irradiation Model.

    PubMed

    Ossetrova, Natalia I; Ney, Patrick H; Condliffe, Donald P; Krasnopolsky, Katya; Hieber, Kevin P

    2016-08-01

    Radiation accidents or terrorist attacks can result in serious consequences for the civilian population and for military personnel responding to such emergencies. The early medical management situation requires quantitative indications for early initiation of cytokine therapy in individuals exposed to life-threatening radiation doses and effective triage tools for first responders in mass-casualty radiological incidents. Previously established animal (Mus musculus, Macaca mulatta) total-body irradiation (γ-exposure) models have evaluated a panel of radiation-responsive proteins that, together with peripheral blood cell counts, create a multiparametic dose-predictive algorithm with a threshold for detection of ~1 Gy from 1 to 7 d after exposure as well as demonstrate the acute radiation syndrome severity score systems created similar to the Medical Treatment Protocols for Radiation Accident Victims developed by Fliedner and colleagues. The authors present a further demonstration of the acute radiation sickness severity score system in a mouse (CD2F1, males) TBI model (1-14 Gy, Co γ-rays at 0.6 Gy min) based on multiple biodosimetric endpoints. This includes the acute radiation sickness severity Observational Grading System, survival rate, weight changes, temperature, peripheral blood cell counts and radiation-responsive protein expression profile: Flt-3 ligand, interleukin 6, granulocyte-colony stimulating factor, thrombopoietin, erythropoietin, and serum amyloid A. Results show that use of the multiple-parameter severity score system facilitates identification of animals requiring enhanced monitoring after irradiation and that proteomics are a complementary approach to conventional biodosimetry for early assessment of radiation exposure, enhancing accuracy and discrimination index for acute radiation sickness response categories and early prediction of outcome. PMID:27356057

  15. Behavioral and Genetic Dissection of a Mouse Model for Advanced Sleep Phase Syndrome

    PubMed Central

    Jiang, Peng; Striz, Martin; Wisor, Jonathan P.; O'Hara, Bruce F.

    2011-01-01

    Study Objective: The adaptive value of the endogenous circadian clock arises from its ability to synchronize (i.e., entrain) to external light-dark (LD) cycles at an appropriate phase. Studies have suggested that advanced circadian phase alignment might result from shortening of the period length of the clock. Here we explore mechanisms that contribute to an early activity phase in CAST/EiJ (CAST) mice. Methods: We investigated circadian rhythms of wheel-running activity in C57BL/6J (B6), CAST and 2 strains of B6.CAST congenic mice, which carry CAST segments introgressed in a B6 genome. Results: When entrained, all CAST mice initiate daily activity several hours earlier than normal mice. This difference could not be explained by alterations in the endogenous period, as activity onset did not correlate with period length. However, the photic phase-shifting responses in these mice were phase-lagged by 3 hours relative to their activity. Attenuated light masking responses were also found in CAST mice, which allow for activity normally inhibited by light. A previously identified quantitative trait locus (QTL), Era1, which contributes to the early activity trait, was confirmed and refined here using two B6.CAST congenic strains. Surprisingly, these B6.CAST mice exhibited longer rather than shorter endogenous periods, further demonstrating that the advanced phase in these mice is not due to alterations in period. Conclusions: CAST mice have an advanced activity phase similar to human advanced sleep phase syndrome. This advanced phase is not due to its shorter period length or smaller light-induced phase shifts, but appears to be related to both light masking and altered coupling of the circadian pacemaker with various outputs. Lastly, a QTL influencing this trait was confirmed and narrowed using congenic mice as a first step toward gene identification. Citation: Jiang P; Striz M; Wisor JP; O'Hara BF. Behavioral and genetic dissection of a mouse model for advanced sleep

  16. Biomechanical properties of bone in a mouse model of Rett syndrome

    PubMed Central

    Kamal, Bushra; Russell, David; Payne, Anthony; Constante, Diogo; Tanner, K. Elizabeth; Isaksson, Hanna; Mathavan, Neashan; Cobb, Stuart R.

    2015-01-01

    Rett syndrome (RTT) is an X-linked genetic disorder and a major cause of intellectual disability in girls. Mutations in the methyl-CpG binding protein 2 (MECP2) gene are the primary cause of the disorder. Despite the dominant neurological phenotypes, MECP2 is expressed ubiquitously throughout the body and a number of peripheral phenotypes such as scoliosis, reduced bone mineral density and skeletal fractures are also common and important clinical features of the disorder. In order to explore whether MeCP2 protein deficiency results in altered structural and functional properties of bone and to test the potential reversibility of any defects, we have conducted a series of histological, imaging and biomechanical tests of bone in a functional knockout mouse model of RTT. Both hemizygous Mecp2stop/y male mice in which Mecp2 is silenced in all cells and female Mecp2stop/+ mice in which Mecp2 is silenced in ~ 50% of cells as a consequence of random X-chromosome inactivation, revealed significant reductions in cortical bone stiffness, microhardness and tensile modulus. Microstructural analysis also revealed alterations in both cortical and cancellous femoral bone between wild-type and MeCP2-deficient mice. Furthermore, unsilencing of Mecp2 in adult mice cre-mediated stop cassette deletion resulted in a restoration of biomechanical properties (stiffness, microhardness) towards wild-type levels. These results show that MeCP2-deficiency results in overt, but potentially reversible, alterations in the biomechanical integrity of bone and highlights the importance of targeting skeletal phenotypes in considering the development of pharmacological and gene-based therapies. PMID:25445449

  17. Effectiveness of trimebutine maleate on modulating intestinal hypercontractility in a mouse model of postinfectious irritable bowel syndrome.

    PubMed

    Long, Yanqin; Liu, Ying; Tong, Jingjing; Qian, Wei; Hou, Xiaohua

    2010-06-25

    Trimebutine maleate, which modulates the calcium and potassium channels, relieves abdominal pain in patients with irritable bowel syndrome. However, its effect on postinfectious irritable bowel syndrome is not clarified. The aim of this study was to investigate the effectiveness of trimebutine maleate on modulating colonic hypercontractility in a mouse model of postinfectious irritable bowel syndrome. Mice infected up to 8 weeks with T. spiralis underwent abdominal withdrawal reflex to colorectal distention to evaluate the visceral sensitivity at different time points. Tissues were examined for histopathology scores. Colonic longitudinal muscle strips were prepared in the organ bath under basal condition or to be stimulated by acetylcholine and potassium chloride, and consecutive concentrations of trimebutine maleate were added to the bath to record the strip responses. Significant inflammation was observed in the intestines of the mice infected 2 weeks, and it resolved in 8 weeks after infection. Visceral hyperalgesia and colonic muscle hypercontractility emerged after infection, and trimebutine maleate could effectively reduce the colonic hyperreactivity. Hypercontractility of the colonic muscle stimulated by acetylcholine and high K(+) could be inhibited by trimebutine maleate in solution with Ca(2+), but not in Ca(2+) free solution. Compared with 8-week postinfectious irritable bowel syndrome group, 2-week acute infected strips were much more sensitive to the stimulators and the drug trimebutine maleate. Trimebutine maleate was effective in reducing the colonic muscle hypercontractility of postinfectious irritable bowel syndrome mice. The findings may provide evidence for trimebutine maleate to treat postinfectious irritable bowel syndrome patients effectively. PMID:20371236

  18. Pharmacological interference with the glucocorticoid system influences symptoms and lifespan in a mouse model of Rett syndrome.

    PubMed

    Braun, Sebastian; Kottwitz, Denise; Nuber, Ulrike A

    2012-04-15

    Rett syndrome (RTT) is caused by loss-of-function mutations in the X-linked gene MECP2 coding for methyl CpG-binding protein 2 (MeCP2). This protein can act as transcriptional repressor, and we showed in a previous study that glucocorticoid-inducible genes are up-regulated in an RTT mouse model and that these genes are direct MeCP2 targets. Here, we report that pharmacological intervention with the glucocorticoid system has an impact on the symptoms and lifespan in an RTT mouse model. Our data support a functional implication of the stress hormone system in RTT and suggest this hormone system as potential therapeutic target. PMID:22186023

  19. FGF/FGFR Signaling Coordinates Skull Development by Modulating Magnitude of Morphological Integration: Evidence from Apert Syndrome Mouse Models

    PubMed Central

    Martínez-Abadías, Neus; Heuzé, Yann; Wang, Yingli; Jabs, Ethylin Wang; Aldridge, Kristina; Richtsmeier, Joan T.

    2011-01-01

    The fibroblast growth factor and receptor system (FGF/FGFR) mediates cell communication and pattern formation in many tissue types (e.g., osseous, nervous, vascular). In those craniosynostosis syndromes caused by FGFR1-3 mutations, alteration of signaling in the FGF/FGFR system leads to dysmorphology of the skull, brain and limbs, among other organs. Since this molecular pathway is widely expressed throughout head development, we explore whether and how two specific mutations on Fgfr2 causing Apert syndrome in humans affect the pattern and level of integration between the facial skeleton and the neurocranium using inbred Apert syndrome mouse models Fgfr2+/S252W and Fgfr2+/P253R and their non-mutant littermates at P0. Skull morphological integration (MI), which can reflect developmental interactions among traits by measuring the intensity of statistical associations among them, was assessed using data from microCT images of the skull of Apert syndrome mouse models and 3D geometric morphometric methods. Our results show that mutant Apert syndrome mice share the general pattern of MI with their non-mutant littermates, but the magnitude of integration between and within the facial skeleton and the neurocranium is increased, especially in Fgfr2+/S252W mice. This indicates that although Fgfr2 mutations do not disrupt skull MI, FGF/FGFR signaling is a covariance-generating process in skull development that acts as a global factor modulating the intensity of MI. As this pathway evolved early in vertebrate evolution, it may have played a significant role in establishing the patterns of skull MI and coordinating proper skull development. PMID:22053191

  20. Possible Therapeutic Doses of Cannabinoid Type 1 Receptor Antagonist Reverses Key Alterations in Fragile X Syndrome Mouse Model.

    PubMed

    Gomis-González, Maria; Matute, Carlos; Maldonado, Rafael; Mato, Susana; Ozaita, Andrés

    2016-01-01

    Fragile X syndrome (FXS) is the most common monogenetic cause of intellectual disability. The cognitive deficits in the mouse model for this disorder, the Fragile X Mental Retardation 1 (Fmr1) knockout (KO) mouse, have been restored by different pharmacological approaches, among those the blockade of cannabinoid type 1 (CB1) receptor. In this regard, our previous study showed that the CB1 receptor antagonist/inverse agonist rimonabant normalized a number of core features in the Fmr1 knockout mouse. Rimonabant was commercialized at high doses for its anti-obesity properties, and withdrawn from the market on the bases of mood-related adverse effects. In this study we show, by using electrophysiological approaches, that low dosages of rimonabant (0.1 mg/kg) manage to normalize metabotropic glutamate receptor dependent long-term depression (mGluR-LTD). In addition, low doses of rimonabant (from 0.01 mg/kg) equally normalized the cognitive deficit in the mouse model of FXS. These doses of rimonabant were from 30 to 300 times lower than those required to reduce body weight in rodents and to presumably produce adverse effects in humans. Furthermore, NESS0327, a CB1 receptor neutral antagonist, was also effective in preventing the novel object-recognition memory deficit in Fmr1 KO mice. These data further support targeting CB1 receptors as a relevant therapy for FXS. PMID:27589806

  1. The fetal brain transcriptome and neonatal behavioral phenotype in the Ts1Cje mouse model of Down syndrome.

    PubMed

    Guedj, Faycal; Pennings, Jeroen L A; Ferres, Millie A; Graham, Leah C; Wick, Heather C; Miczek, Klaus A; Slonim, Donna K; Bianchi, Diana W

    2015-09-01

    Human fetuses with Down syndrome demonstrate abnormal brain growth and reduced neurogenesis. Despite the prenatal onset of the phenotype, most therapeutic trials have been conducted in adults. Here, we present evidence for fetal brain molecular and neonatal behavioral alterations in the Ts1Cje mouse model of Down syndrome. Embryonic day 15.5 brain hemisphere RNA from Ts1Cje embryos (n = 5) and wild type littermates (n = 5) was processed and hybridized to mouse gene 1.0 ST arrays. Bioinformatic analyses were implemented to identify differential gene and pathway regulation during Ts1Cje fetal brain development. In separate experiments, the Fox scale, ultrasonic vocalization and homing tests were used to investigate behavioral deficits in Ts1Cje pups (n = 29) versus WT littermates (n = 64) at postnatal days 3-21. Ts1Cje fetal brains displayed more differentially regulated genes (n = 71) than adult (n = 31) when compared to their age-matched euploid brains. Ts1Cje embryonic brains showed up-regulation of cell cycle markers and down-regulation of the solute-carrier amino acid transporters. Several cellular processes were dysregulated at both stages, including apoptosis, inflammation, Jak/Stat signaling, G-protein signaling, and oxidoreductase activity. In addition, early behavioral deficits in surface righting, cliff aversion, negative geotaxis, forelimb grasp, ultrasonic vocalization, and the homing tests were observed. The Ts1Cje mouse model exhibits abnormal gene expression during fetal brain development, and significant neonatal behavioral deficits in the pre-weaning period. In combination with human studies, this suggests that the Down syndrome phenotype manifests prenatally and provides a rationale for prenatal therapy to improve perinatal brain development and postnatal neurocognition. PMID:25975229

  2. VPA Alleviates Neurological Deficits and Restores Gene Expression in a Mouse Model of Rett Syndrome

    PubMed Central

    Otsuka I., Maky; Irie, Koichiro; Igarashi, Katsuhide; Nakashima, Kinichi; Zhao, Xinyu

    2014-01-01

    Rett syndrome (RTT) is a devastating neurodevelopmental disorder that occurs once in every 10,000–15,000 live female births. Despite intensive research, no effective cure is yet available. Valproic acid (VPA) has been used widely to treat mood disorder, epilepsy, and a growing number of other disorders. In limited clinical studies, VPA has also been used to control seizure in RTT patients with promising albeit somewhat unclear efficacy. In this study we tested the effect of VPA on the neurological symptoms of RTT and discovered that short-term VPA treatment during the symptomatic period could reduce neurological symptoms in RTT mice. We found that VPA restores the expression of a subset of genes in RTT mouse brains, and these genes clustered in neurological disease and developmental disorder networks. Our data suggest that VPA could be used as a drug to alleviate RTT symptoms. PMID:24968028

  3. Repeated sense of hunger leads to the development of visceral obesity and metabolic syndrome in a mouse model.

    PubMed

    Han, Jong-Min; Kim, Hyeong-Geug; Lee, Jin-Seok; Choi, Min-Kyung; Kim, Young-Ae; Son, Chang-Gue

    2014-01-01

    Obesity-related disorders, especially metabolic syndrome, contribute to 2.8 million deaths each year worldwide, with significantly increasing morbidity. Eating at regular times and proper food quantity are crucial for maintaining a healthy status. However, many people in developed countries do not follow a regular eating schedule due to a busy lifestyle. Herein, we show that a repeated sense of hunger leads to a high risk of developing visceral obesity and metabolic syndrome in a mouse model (both 3-week and 6-week-old age, 10 mice in each group). The ad libitum (AL) group (normal eating pattern) and the food restriction (FR) group (alternate-day partially food restriction by given only 1/3 of average amount) were compared after 8-week experimental period. The total food consumption in the FR group was lower than in the AL group, however, the FR group showed a metabolic syndrome-like condition with significant fat accumulation in adipose tissues. Consequently, the repeated sense of hunger induced the typical characteristics of metabolic syndrome in an animal model; a distinct visceral obesity, hyperlipidemia, hyperglycemia and hepatic steatosis. Furthermore, we found that specifically leptin, a major metabolic hormone, played a major role in the development of these pathological disorders. Our study indicated the importance of regular eating habits besides controlling calorie intake. PMID:24879081

  4. Repeated Sense of Hunger Leads to the Development of Visceral Obesity and Metabolic Syndrome in a Mouse Model

    PubMed Central

    Han, Jong-Min; Kim, Hyeong-Geug; Lee, Jin-Seok; Choi, Min-Kyung; Kim, Young-Ae; Son, Chang-Gue

    2014-01-01

    Obesity-related disorders, especially metabolic syndrome, contribute to 2.8 million deaths each year worldwide, with significantly increasing morbidity. Eating at regular times and proper food quantity are crucial for maintaining a healthy status. However, many people in developed countries do not follow a regular eating schedule due to a busy lifestyle. Herein, we show that a repeated sense of hunger leads to a high risk of developing visceral obesity and metabolic syndrome in a mouse model (both 3-week and 6-week-old age, 10 mice in each group). The ad libitum (AL) group (normal eating pattern) and the food restriction (FR) group (alternate-day partially food restriction by given only 1/3 of average amount) were compared after 8-week experimental period. The total food consumption in the FR group was lower than in the AL group, however, the FR group showed a metabolic syndrome-like condition with significant fat accumulation in adipose tissues. Consequently, the repeated sense of hunger induced the typical characteristics of metabolic syndrome in an animal model; a distinct visceral obesity, hyperlipidemia, hyperglycemia and hepatic steatosis. Furthermore, we found that specifically leptin, a major metabolic hormone, played a major role in the development of these pathological disorders. Our study indicated the importance of regular eating habits besides controlling calorie intake. PMID:24879081

  5. Matriptase initiates activation of epidermal pro-kallikrein and disease onset in a mouse model of Netherton syndrome.

    PubMed

    Sales, Katiuchia Uzzun; Masedunskas, Andrius; Bey, Alexandra L; Rasmussen, Amber L; Weigert, Roberto; List, Karin; Szabo, Roman; Overbeek, Paul A; Bugge, Thomas H

    2010-08-01

    Deficiency in the serine protease inhibitor LEKTI is the etiological origin of Netherton syndrome, which causes detachment of the stratum corneum and chronic inflammation. Here we show that the membrane protease matriptase initiates Netherton syndrome in a LEKTI-deficient mouse model by premature activation of a pro-kallikrein cascade. Auto-activation of pro-inflammatory pro-kallikrein-related peptidases that are associated with stratum corneum detachment was either low or undetectable, but they were efficiently activated by matriptase. Ablation of matriptase from LEKTI-deficient mice dampened inflammation, eliminated aberrant protease activity, prevented detachment of the stratum corneum, and improved the barrier function of the epidermis. These results uncover a pathogenic matriptase-pro-kallikrein pathway that could operate in several human skin and inflammatory diseases. PMID:20657595

  6. Molecular determinants of severe acute respiratory syndrome coronavirus pathogenesis and virulence in young and aged mouse models of human disease.

    PubMed

    Frieman, Matthew; Yount, Boyd; Agnihothram, Sudhakar; Page, Carly; Donaldson, Eric; Roberts, Anjeanette; Vogel, Leatrice; Woodruff, Becky; Scorpio, Diana; Subbarao, Kanta; Baric, Ralph S

    2012-01-01

    SARS coronavirus (SARS-CoV) causes severe acute respiratory tract disease characterized by diffuse alveolar damage and hyaline membrane formation. This pathology often progresses to acute respiratory distress (such as acute respiratory distress syndrome [ARDS]) and atypical pneumonia in humans, with characteristic age-related mortality rates approaching 50% or more in immunosenescent populations. The molecular basis for the extreme virulence of SARS-CoV remains elusive. Since young and aged (1-year-old) mice do not develop severe clinical disease following infection with wild-type SARS-CoV, a mouse-adapted strain of SARS-CoV (called MA15) was developed and was shown to cause lethal infection in these animals. To understand the genetic contributions to the increased pathogenesis of MA15 in rodents, we used reverse genetics and evaluated the virulence of panels of derivative viruses encoding various combinations of mouse-adapted mutations. We found that mutations in the viral spike (S) glycoprotein and, to a much less rigorous extent, in the nsp9 nonstructural protein, were primarily associated with the acquisition of virulence in young animals. The mutations in S likely increase recognition of the mouse angiotensin-converting enzyme 2 (ACE2) receptor not only in MA15 but also in two additional, independently isolated mouse-adapted SARS-CoVs. In contrast to the findings for young animals, mutations to revert to the wild-type sequence in nsp9 and the S glycoprotein were not sufficient to significantly attenuate the virus compared to other combinations of mouse-adapted mutations in 12-month-old mice. This panel of SARS-CoVs provides novel reagents that we have used to further our understanding of differential, age-related pathogenic mechanisms in mouse models of human disease. PMID:22072787

  7. Molecular Determinants of Severe Acute Respiratory Syndrome Coronavirus Pathogenesis and Virulence in Young and Aged Mouse Models of Human Disease

    PubMed Central

    Yount, Boyd; Agnihothram, Sudhakar; Page, Carly; Donaldson, Eric; Roberts, Anjeanette; Vogel, Leatrice; Woodruff, Becky; Scorpio, Diana; Subbarao, Kanta; Baric, Ralph S.

    2012-01-01

    SARS coronavirus (SARS-CoV) causes severe acute respiratory tract disease characterized by diffuse alveolar damage and hyaline membrane formation. This pathology often progresses to acute respiratory distress (such as acute respiratory distress syndrome [ARDS]) and atypical pneumonia in humans, with characteristic age-related mortality rates approaching 50% or more in immunosenescent populations. The molecular basis for the extreme virulence of SARS-CoV remains elusive. Since young and aged (1-year-old) mice do not develop severe clinical disease following infection with wild-type SARS-CoV, a mouse-adapted strain of SARS-CoV (called MA15) was developed and was shown to cause lethal infection in these animals. To understand the genetic contributions to the increased pathogenesis of MA15 in rodents, we used reverse genetics and evaluated the virulence of panels of derivative viruses encoding various combinations of mouse-adapted mutations. We found that mutations in the viral spike (S) glycoprotein and, to a much less rigorous extent, in the nsp9 nonstructural protein, were primarily associated with the acquisition of virulence in young animals. The mutations in S likely increase recognition of the mouse angiotensin-converting enzyme 2 (ACE2) receptor not only in MA15 but also in two additional, independently isolated mouse-adapted SARS-CoVs. In contrast to the findings for young animals, mutations to revert to the wild-type sequence in nsp9 and the S glycoprotein were not sufficient to significantly attenuate the virus compared to other combinations of mouse-adapted mutations in 12-month-old mice. This panel of SARS-CoVs provides novel reagents that we have used to further our understanding of differential, age-related pathogenic mechanisms in mouse models of human disease. PMID:22072787

  8. Effects of aneuploidy on skull growth in a mouse model of Down syndrome

    PubMed Central

    Hill, Cheryl A; Reeves, Roger H; Richtsmeier, Joan T

    2007-01-01

    Adult craniofacial morphology results from complex interactions among genetic, epigenetic and environmental factors. Trisomy causes perturbations in the genetic programmes that control development and these are reflected in morphology that can either ameliorate or worsen with time and growth. Many of the specific changes that occur in Down syndrome can be studied in the Ts65Dn trisomic mouse, which shows direct parallels with specific aspects of adult craniofacial dysmorphology associated with trisomy 21. This study investigates patterns of craniofacial growth in Ts65Dn mice and their euploid littermates to assess how the adult dysmorphology develops. Three-dimensional coordinate data were collected from microcomputed tomography scans of the face, cranial base, palate and mandible of newborn (P0) and adult trisomic and euploid mice. Growth patterns were analysed using Euclidean distance matrix analysis. P0 trisomic mice show significant differences in craniofacial shape. Growth is reduced along the rostro-caudal axis of the Ts65Dn face and palate relative to euploid littermates and Ts65Dn mandibles demonstrate reduced growth local to the mandibular processes. Thus, the features of Down syndrome that are reflected in the mature Ts65Dn skull are established early in development and growth does not appear to ameliorate them. Differences in growth may in fact contribute to many of the morphological differences that are evident at birth in trisomic mice and humans. PMID:17428201

  9. Aging and Intellectual Disability: Insights from Mouse Models of Down Syndrome

    ERIC Educational Resources Information Center

    Ruparelia, Aarti; Pearn, Matthew L.; Mobley, William C.

    2013-01-01

    Down syndrome (DS) is one of many causes of intellectual disability (ID), others including but not limited to, fetal alcohol syndrome, Fragile X syndrome, Rett syndrome, Williams syndrome, hypoxia, and infection. Down syndrome is characterized by a number of neurobiological problems resulting in learning and memory deficits and early onset…

  10. A defect in early myogenesis causes Otitis media in two mouse models of 22q11.2 Deletion Syndrome

    PubMed Central

    Fuchs, Jennifer C.; Linden, Jennifer F.; Baldini, Antonio; Tucker, Abigail S.

    2015-01-01

    Otitis media (OM), the inflammation of the middle ear, is the most common disease and cause for surgery in infants worldwide. Chronic Otitis media with effusion (OME) often leads to conductive hearing loss and is a common feature of a number of craniofacial syndromes, such as 22q11.2 Deletion Syndrome (22q11.2DS). OM is more common in children because the more horizontal position of the Eustachian tube (ET) in infants limits or delays clearance of middle ear effusions. Some mouse models with OM have shown alterations in the morphology and angle of the ET. Here, we present a novel mechanism in which OM is caused not by a defect in the ET itself but in the muscles that control its function. Our results show that in two mouse models of 22q11.2DS (Df1/+ and Tbx1+/−) presenting with bi- or unilateral OME, the fourth pharyngeal arch-derived levator veli palatini muscles were hypoplastic, which was associated with an earlier altered pattern of MyoD expression. Importantly, in mice with unilateral OME, the side with the inflammation was associated with significantly smaller muscles than the contralateral unaffected ear. Functional tests examining ET patency confirmed a reduced clearing ability in the heterozygous mice. Our findings are also of clinical relevance as targeting hypoplastic muscles might present a novel preventative measure for reducing the high rates of OM in 22q11.2DS patients. PMID:25452432

  11. Lethal, neonatal ichthyosis with increased proteolytic processing of filaggrin in a mouse model of Netherton syndrome.

    PubMed

    Hewett, Duncan R; Simons, Alison L; Mangan, Niamh E; Jolin, Helen E; Green, Shelia M; Fallon, Padraic G; McKenzie, Andrew N J

    2005-01-15

    Netherton syndrome is an autosomal recessive multisystemic disorder characterized by congenital ichthyosiform erythroderma, hair shaft defects and atopy, caused by mutations within the human SPINK5 gene. To investigate the development of this disease, we have cloned mouse spink5 and created mice with a mutated premature stop codon at amino acid R820X, to produce an allele that closely mimics a point mutation (E827X) in human SPINK5. Newborn spink5(R820X/R820X) mice develop a lethal, severe ichthyosis with a loss of skin barrier function and dehydration, resulting in death within a few hours of birth, similar to that observed in patients with severe Netherton syndrome. Epidermal barrier function is compromised because of the stratum corneum becoming spontaneously detached in the newborn mice, and this is probably compounded by the reduced mechanical strength detected in the cornified envelopes. Biochemical analysis of skin from newborn wild-type and spink5(R820X/R820X) mice revealed a substantial increase in the proteolytic processing of profilaggrin into its constituent filaggrin monomers. Filaggrin functions to organize keratin filaments into highly ordered macrofibrils that crisscross the cornified cells of the stratum corneum imparting structural integrity, and defects in filaggrin processing occur in a number of forms of congenital ichthyosis. These data suggest that in the absence of the serine protease inhibitor spink5, there is an abnormal increase in the processing of profilaggrin, resulting in an overabundance of filaggrin monomers, and that this may play a direct role in the observed deficit in the adhesion of the stratum corneum and the severely compromised epidermal barrier function. PMID:15590704

  12. Astrocyte Transcriptome from the Mecp2(308)-Truncated Mouse Model of Rett Syndrome.

    PubMed

    Delépine, Chloé; Nectoux, Juliette; Letourneur, Franck; Baud, Véronique; Chelly, Jamel; Billuart, Pierre; Bienvenu, Thierry

    2015-12-01

    Mutations in the gene encoding the transcriptional modulator methyl-CpG binding protein 2 (MeCP2) are responsible for the neurodevelopmental disorder Rett syndrome which is one of the most frequent sources of intellectual disability in women. Recent studies showed that loss of Mecp2 in astrocytes contributes to Rett-like symptoms and restoration of Mecp2 can rescue some of these defects. The goal of this work is to compare gene expression profiles of wild-type and mutant astrocytes from Mecp2(308/y) mice (B6.129S-MeCP2/J) by using Affymetrix mouse 2.0 microarrays. Results were confirmed by quantitative real-time RT-PCR and by Western blot analysis. Gene set enrichment analysis utilizing Ingenuity Pathways was employed to identify pathways disrupted by Mecp2 deficiency. A total of 2152 genes were statistically differentially expressed between wild-type and mutated samples, including 1784 coding transcripts. However, only 257 showed fold changes >1.2. We confirmed our data by replicative studies in independent primary cultures of cortical astrocytes from Mecp2-deficient mice. Interestingly, two genes known to encode secreted proteins, chromogranin B and lipocalin-2, showed significant dysregulation. These proteins secreted from Mecp2-deficient glia may exert negative non-cell autonomous effects on neuronal properties, including dendritic morphology. Moreover, transcriptional profiling revealed altered Nr2f2 expression which may explain down- and upregulation of several target genes in astrocytes such as Ccl2, Lcn2 and Chgb. Unraveling Nr2f2 involvement in Mecp2-deficient astrocytes could pave the way for a better understanding of Rett syndrome pathophysiology and offers new therapeutic perspectives. PMID:26208914

  13. 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

  14. Attentional dysfunction, impulsivity, and resistance to change in a mouse model of fragile X syndrome.

    PubMed

    Moon, J; Beaudin, A E; Verosky, S; Driscoll, L L; Weiskopf, M; Levitsky, D A; Crnic, L S; Strupp, B J

    2006-12-01

    On a series of attention tasks, male mice with a mutation targeted to the fragile X mental retardation 1 (Fmrl) gene (Fmrl knockout [KO] mice) committed a higher rate of premature responses than wild-type littermates, with the largest differences seen when task contingencies changed. This finding indicates impaired inhibitory control, particularly during times of stress or arousal. The KO mice also committed a higher rate of inaccurate responses than controls, particularly during the final third of each daily test session, indicating impaired sustained attention. In the selective attention task, the unpredictable presentation of potent olfactory distractors produced a generalized disruption in the performance of the KO mice, whereas for controls, the disruption produced by the distractors was temporally limited. Finally, the attentional disruption seen following an error was more pronounced for the KO mice than for controls, further implicating impaired regulation of arousal and/or negative affect. The present study provides the first evidence that the Fmrl KO mouse is impaired in inhibitory control, attention, and arousal regulation, hallmark areas of dysfunction in fragile X syndrome. The resistance to change also seen in these mice provides a behavioral index for studying the autistic features of this disorder. PMID:17201482

  15. Misregulation of Alternative Splicing in a Mouse Model of Rett Syndrome.

    PubMed

    Li, Ronghui; Dong, Qiping; Yuan, Xinni; Zeng, Xin; Gao, Yu; Chiao, Cassandra; Li, Hongda; Zhao, Xinyu; Keles, Sunduz; Wang, Zefeng; Chang, Qiang

    2016-06-01

    Mutations in the human MECP2 gene cause Rett syndrome (RTT), a severe neurodevelopmental disorder that predominantly affects girls. Despite decades of work, the molecular function of MeCP2 is not fully understood. Here we report a systematic identification of MeCP2-interacting proteins in the mouse brain. In addition to transcription regulators, we found that MeCP2 physically interacts with several modulators of RNA splicing, including LEDGF and DHX9. These interactions are disrupted by RTT causing mutations, suggesting that they may play a role in RTT pathogenesis. Consistent with the idea, deep RNA sequencing revealed misregulation of hundreds of splicing events in the cortex of Mecp2 knockout mice. To reveal the functional consequence of altered RNA splicing due to the loss of MeCP2, we focused on the regulation of the splicing of the flip/flop exon of Gria2 and other AMPAR genes. We found a significant splicing shift in the flip/flop exon toward the flop inclusion, leading to a faster decay in the AMPAR gated current and altered synaptic transmission. In summary, our study identified direct physical interaction between MeCP2 and splicing factors, a novel MeCP2 target gene, and established functional connection between a specific RNA splicing change and synaptic phenotypes in RTT mice. These results not only help our understanding of the molecular function of MeCP2, but also reveal potential drug targets for future therapies. PMID:27352031

  16. Misregulation of Alternative Splicing in a Mouse Model of Rett Syndrome

    PubMed Central

    Li, Ronghui; Dong, Qiping; Yuan, Xinni; Zeng, Xin; Gao, Yu; Li, Hongda; Keles, Sunduz; Wang, Zefeng; Chang, Qiang

    2016-01-01

    Mutations in the human MECP2 gene cause Rett syndrome (RTT), a severe neurodevelopmental disorder that predominantly affects girls. Despite decades of work, the molecular function of MeCP2 is not fully understood. Here we report a systematic identification of MeCP2-interacting proteins in the mouse brain. In addition to transcription regulators, we found that MeCP2 physically interacts with several modulators of RNA splicing, including LEDGF and DHX9. These interactions are disrupted by RTT causing mutations, suggesting that they may play a role in RTT pathogenesis. Consistent with the idea, deep RNA sequencing revealed misregulation of hundreds of splicing events in the cortex of Mecp2 knockout mice. To reveal the functional consequence of altered RNA splicing due to the loss of MeCP2, we focused on the regulation of the splicing of the flip/flop exon of Gria2 and other AMPAR genes. We found a significant splicing shift in the flip/flop exon toward the flop inclusion, leading to a faster decay in the AMPAR gated current and altered synaptic transmission. In summary, our study identified direct physical interaction between MeCP2 and splicing factors, a novel MeCP2 target gene, and established functional connection between a specific RNA splicing change and synaptic phenotypes in RTT mice. These results not only help our understanding of the molecular function of MeCP2, but also reveal potential drug targets for future therapies. PMID:27352031

  17. Quantitative Profiling of Brain Lipid Raft Proteome in a Mouse Model of Fragile X Syndrome

    PubMed Central

    Kalinowska, Magdalena; Castillo, Catherine; Francesconi, Anna

    2015-01-01

    Fragile X Syndrome, a leading cause of inherited intellectual disability and autism, arises from transcriptional silencing of the FMR1 gene encoding an RNA-binding protein, Fragile X Mental Retardation Protein (FMRP). FMRP can regulate the expression of approximately 4% of brain transcripts through its role in regulation of mRNA transport, stability and translation, thus providing a molecular rationale for its potential pleiotropic effects on neuronal and brain circuitry function. Several intracellular signaling pathways are dysregulated in the absence of FMRP suggesting that cellular deficits may be broad and could result in homeostatic changes. Lipid rafts are specialized regions of the plasma membrane, enriched in cholesterol and glycosphingolipids, involved in regulation of intracellular signaling. Among transcripts targeted by FMRP, a subset encodes proteins involved in lipid biosynthesis and homeostasis, dysregulation of which could affect the integrity and function of lipid rafts. Using a quantitative mass spectrometry-based approach we analyzed the lipid raft proteome of Fmr1 knockout mice, an animal model of Fragile X syndrome, and identified candidate proteins that are differentially represented in Fmr1 knockout mice lipid rafts. Furthermore, network analysis of these candidate proteins reveals connectivity between them and predicts functional connectivity with genes encoding components of myelin sheath, axonal processes and growth cones. Our findings provide insight to aid identification of molecular and cellular dysfunctions arising from Fmr1 silencing and for uncovering shared pathologies between Fragile X syndrome and other autism spectrum disorders. PMID:25849048

  18. Preservation of Long-Term Memory and Synaptic Plasticity Despite Short-Term Impairments in the Tc1 Mouse Model of Down Syndrome

    ERIC Educational Resources Information Center

    Morice, Elise; Andreae, Laura C.; Cooke, Sam F.; Vanes, Lesley; Fisher, Elizabeth M. C.; Tybulewicz, Victor L. J.; Bliss, Timothy V. P.

    2008-01-01

    Down syndrome (DS) is a genetic disorder arising from the presence of a third copy of the human chromosome 21 (Hsa21). Recently, O'Doherty and colleagues in an earlier study generated a new genetic mouse model of DS (Tc1) that carries an almost complete Hsa21. Since DS is the most common genetic cause of mental retardation, we have undertaken a…

  19. Abnormal response to the anorexic effect of GHS-R inhibitors and exenatide in male Snord116 deletion mouse model for Prader-Willi Syndrome

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Prader-Willi syndrome (PWS) is a genetic disease characterized by persistent hunger and hyperphagia. The lack of the Snord116 small nucleolar RNA cluster has been identified as the major contributor to PWS symptoms. The Snord116 deletion (Snord116del) mouse model manifested a subset of PWS symptoms ...

  20. In vivo synaptic transmission and morphology in mouse models of Tuberous sclerosis, Fragile X syndrome, Neurofibromatosis type 1, and Costello syndrome.

    PubMed

    Wang, Tiantian; de Kok, Laura; Willemsen, Rob; Elgersma, Ype; Borst, J Gerard G

    2015-01-01

    Defects in the rat sarcoma viral oncogene homolog (Ras)/extracellular-signal-regulated kinase and the phosphatidylinositol 3-kinase-mammalian target of rapamycin (mTOR) signaling pathways are responsible for several neurodevelopmental disorders. These disorders are an important cause for intellectual disability; additional manifestations include autism spectrum disorder, seizures, and brain malformations. Changes in synaptic function are thought to underlie the neurological conditions associated with these syndromes. We therefore studied morphology and in vivo synaptic transmission of the calyx of Held synapse, a relay synapse in the medial nucleus of the trapezoid body (MNTB) of the auditory brainstem, in mouse models of tuberous sclerosis complex (TSC), Fragile X syndrome (FXS), Neurofibromatosis type 1 (NF1), and Costello syndrome. Calyces from both Tsc1(+/-) and from Fmr1 knock-out (KO) mice showed increased volume and surface area compared to wild-type (WT) controls. In addition, in Fmr1 KO animals a larger fraction of calyces showed complex morphology. In MNTB principal neurons of Nf1 (+/) (-) mice the average delay between EPSPs and APs was slightly smaller compared to WT controls, which could indicate an increased excitability. Otherwise, no obvious changes in synaptic transmission, or short-term plasticity were observed during juxtacellular recordings in any of the four lines. Our results in these four mutants thus indicate that abnormalities of mTOR or Ras signaling do not necessarily result in changes in in vivo synaptic transmission. PMID:26190969

  1. In vivo synaptic transmission and morphology in mouse models of Tuberous sclerosis, Fragile X syndrome, Neurofibromatosis type 1, and Costello syndrome

    PubMed Central

    Wang, Tiantian; de Kok, Laura; Willemsen, Rob; Elgersma, Ype; Borst, J. Gerard G.

    2015-01-01

    Defects in the rat sarcoma viral oncogene homolog (Ras)/extracellular-signal-regulated kinase and the phosphatidylinositol 3-kinase-mammalian target of rapamycin (mTOR) signaling pathways are responsible for several neurodevelopmental disorders. These disorders are an important cause for intellectual disability; additional manifestations include autism spectrum disorder, seizures, and brain malformations. Changes in synaptic function are thought to underlie the neurological conditions associated with these syndromes. We therefore studied morphology and in vivo synaptic transmission of the calyx of Held synapse, a relay synapse in the medial nucleus of the trapezoid body (MNTB) of the auditory brainstem, in mouse models of tuberous sclerosis complex (TSC), Fragile X syndrome (FXS), Neurofibromatosis type 1 (NF1), and Costello syndrome. Calyces from both Tsc1+/- and from Fmr1 knock-out (KO) mice showed increased volume and surface area compared to wild-type (WT) controls. In addition, in Fmr1 KO animals a larger fraction of calyces showed complex morphology. In MNTB principal neurons of Nf1+/- mice the average delay between EPSPs and APs was slightly smaller compared to WT controls, which could indicate an increased excitability. Otherwise, no obvious changes in synaptic transmission, or short-term plasticity were observed during juxtacellular recordings in any of the four lines. Our results in these four mutants thus indicate that abnormalities of mTOR or Ras signaling do not necessarily result in changes in in vivo synaptic transmission. PMID:26190969

  2. Chronic P7C3 treatment restores hippocampal neurogenesis in the Ts65Dn mouse model of Down Syndrome [Corrected].

    PubMed

    Latchney, Sarah E; Jaramillo, Thomas C; Rivera, Phillip D; Eisch, Amelia J; Powell, Craig M

    2015-03-30

    Down syndrome (DS) is the most common genetic cause of intellectual disability and developmental delay. In addition to cognitive dysfunction, DS patients are marked by diminished neurogenesis, a neuropathological feature also found in the Ts65Dn mouse model of DS. Interestingly, manipulations that enhance neurogenesis - like environmental enrichment or pharmacological agents - improve cognition in Ts65Dn mice. P7C3 is a proneurogenic compound that enhances hippocampal neurogenesis, cell survival, and promotes cognition in aged animals. However, this compound has not been tested in the Ts65Dn mouse model of DS. We hypothesized that P7C3 treatment would reverse or ameliorate the neurogenic deficits in Ts65Dn mice. To test this, adult Ts65Dn and age-matched wild-type (WT) mice were administered vehicle or P7C3 twice daily for 3 months. After 3 months, brains were examined for indices of neurogenesis, including quantification of Ki67, DCX, activated caspase-3 (AC3), and surviving BrdU-immunoreactive(+) cells in the granule cell layer (GCL) of the hippocampal dentate gyrus. P7C3 had no effect on total Ki67+, DCX+, AC3+, or surviving BrdU+ cells in WT mice relative to vehicle. GCL volume was also not changed. In keeping with our hypothesis, however, P7C3-treated Ts65Dn mice had a significant increase in total Ki67+, DCX+, and surviving BrdU+ cells relative to vehicle. P7C3 treatment also decreased AC3+ cell number but had no effect on total GCL volume in Ts65Dn mice. Our findings show 3 months of P7C3 is sufficient to restore the neurogenic deficits observed in the Ts65Dn mouse model of DS. PMID:25668489

  3. Evidence of Altered Age-Related Brain Cytoarchitecture in Mouse Models of Down syndrome: A Diffusional Kurtosis Imaging Study

    PubMed Central

    Nie, Xingju; Hamlett, Eric D.; Granholm, Ann-Charlotte; Hui, Edward S.; Helpern, Joseph A.; Jensen, Jens H.; Boger, Heather A.; Collins, Heather R.; Falangola, Maria F.

    2015-01-01

    Mouse models of Down syndrome (DS) exhibit abnormal brain developmental and neurodegenerative changes similar to those seen in individuals with DS. Although DS mice have been well characterized cognitively and morphologically there are no prior reports utilizing diffusion MRI. In this study we investigated the ability of diffusional kurtosis imaging (DKI) to detect the progressive developmental and neurodegenerative changes in the Ts65Dn (TS) DS mouse model. TS mice displayed higher diffusional kurtosis (DK) in the frontal cortex (FC) compared to normal mice at 2 months of age. At 5 months of age, TS mice had lower radial kurtosis in the striatum (ST), which persisted in the 8-month-old mice. The TS mice exhibited lower DK metrics values in the dorsal hippocampus (HD) at all ages, and the group difference in this region was larger at 8-months. Regression analysis showed that normal mice had a significant age-related increase in DK metrics in FC, ST and HD. On the contrary, the TS mice lacked significant age-related increase in DK metrics in FC and ST. Although preliminary, these results demonstrate that DK metrics can detect TS brain developmental and neurodegenerative abnormalities. PMID:25527393

  4. Transcript Level Alterations Reflect Gene Dosage Effects Across Multiple Tissues in a Mouse Model of Down Syndrome

    PubMed Central

    Kahlem, Pascal; Sultan, Marc; Herwig, Ralf; Steinfath, Matthias; Balzereit, Daniela; Eppens, Barbara; Saran, Nidhi G.; Pletcher, Mathew T.; South, Sarah T.; Stetten, Gail; Lehrach, Hans; Reeves, Roger H.; Yaspo, Marie-Laure

    2004-01-01

    Human trisomy 21, which results in Down syndrome (DS), is one of the most complicated congenital genetic anomalies compatible with life, yet little is known about the molecular basis of DS. It is generally accepted that chromosome 21 (Chr21) transcripts are overexpressed by about 50% in cells with an extra copy of this chromosome. However, this assumption is difficult to test in humans due to limited access to tissues, and direct support for this idea is available for only a few Chr21 genes or in a limited number of tissues. The Ts65Dn mouse is widely used as a model for studies of DS because it is at dosage imbalance for the orthologs of about half of the 284 Chr21 genes. Ts65Dn mice have several features that directly parallel developmental anomalies of DS. Here we compared the expression of 136 mouse orthologs of Chr21 genes in nine tissues of the trisomic and euploid mice. Nearly all of the 77 genes which are at dosage imbalance in Ts65Dn showed increased transcript levels in the tested tissues, providing direct support for a simple model of increased transcription proportional to the gene copy number. However, several genes escaped this rule, suggesting that they may be controlled by additional tissue-specific regulatory mechanisms revealed in the trisomic situation. PMID:15231742

  5. Low dose EGCG treatment beginning in adolescence does not improve cognitive impairment in a Down syndrome mouse model.

    PubMed

    Stringer, Megan; Abeysekera, Irushi; Dria, Karl J; Roper, Randall J; Goodlett, Charles R

    2015-11-01

    Down syndrome (DS) or Trisomy 21 causes intellectual disabilities in humans and the Ts65Dn DS mouse model is deficient in learning and memory tasks. DYRK1A is triplicated in DS and Ts65Dn mice. Ts65Dn mice were given up to ~20mg/kg/day epigallocatechin-3-gallate (EGCG), a Dyrk1a inhibitor, or water beginning on postnatal day 24 and continuing for three or seven weeks, and were tested on a series of behavioral and learning tasks, including a novel balance beam test. Ts65Dn as compared to control mice exhibited higher locomotor activity, impaired novel object recognition, impaired balance beam and decreased spatial learning and memory. Neither EGCG treatment improved performance of the Ts65Dn mice on these tasks. Ts65Dn mice had a non-significant increase in Dyrk1a activity in the hippocampus and cerebellum. Given the translational value of the Ts65Dn mouse model, further studies will be needed to identify the EGCG doses (and mechanisms) that may improve cognitive function. PMID:26363314

  6. The Osteopontin Transgenic Mouse is a New Model for Sjögren’s Syndrome

    PubMed Central

    Husain-Krautter, Sehba; Kramer, Jill M.; Li, Wentian; Guo, Benchang; Rothstein, Thomas L.

    2015-01-01

    Osteopontin (Opn) is a cytokine involved in both physiological and pathological processes, and is elevated in many autoimmune diseases. Sjögren’s syndrome (SS) is an autoimmune disease with a strong female predilection characterized by lymphocytic infiltration of exocrine glands. We hypothesized Opn contributes to SS pathogenesis. We examined an established SS model, and found increased Opn locally and systemically. Next, we examined Opn transgenic (Opn Tg) mice for evidence of SS. Opn Tg animals exhibited lymphocytic infiltration of salivary and lacrimal glands, and Opn co-localized with the infiltrates. Moreover, saliva production was reduced, and SS autoantibodies were observed in the serum of these mice. Finally, female Opn Tg mice showed more severe disease compared to males. Taken together, these data support a role for Opn in SS pathogenesis. We identify a new model of spontaneous SS that recapitulates the human disease in terms of sex predilection, histopathology, salivary deficits, and autoantibodies. PMID:25572532

  7. The osteopontin transgenic mouse is a new model for Sjögren's syndrome.

    PubMed

    Husain-Krautter, Sehba; Kramer, Jill M; Li, Wentian; Guo, Benchang; Rothstein, Thomas L

    2015-03-01

    Osteopontin (Opn) is a cytokine involved in both physiological and pathological processes, and is elevated in many autoimmune diseases. Sjögren's syndrome (SS) is an autoimmune disease with a strong female predilection characterized by lymphocytic infiltration of exocrine glands. We hypothesized that Opn contributes to SS pathogenesis. We examined an established SS model and found increased Opn locally and systemically. Next, we examined Opn transgenic (Opn Tg) mice for evidence of SS. Opn Tg animals exhibited lymphocytic infiltration of salivary and lacrimal glands, and Opn co-localized with the infiltrates. Moreover, saliva production was reduced, and SS autoantibodies were observed in the serum of these mice. Finally, female Opn Tg mice showed more severe disease compared to males. Taken together, these data support a role for Opn in SS pathogenesis. We identify a new model of spontaneous SS that recapitulates the human disease in terms of sex predilection, histopathology, salivary deficits, and autoantibodies. PMID:25572532

  8. The Mouse Model of Down Syndrome Ts65Dn Presents Visual Deficits as Assessed by Pattern Visual Evoked Potentials

    PubMed Central

    Scott-McKean, Jonah Jacob; Chang, Bo; Hurd, Ronald E.; Nusinowitz, Steven; Schmidt, Cecilia; Davisson, Muriel T.

    2010-01-01

    Purpose. The Ts65Dn mouse is the most complete widely available animal model of Down syndrome (DS). Quantitative information was generated about visual function in the Ts65Dn mouse by investigating their visual capabilities by means of electroretinography (ERG) and patterned visual evoked potentials (pVEPs). Methods. pVEPs were recorded directly from specific regions of the binocular visual cortex of anesthetized mice in response to horizontal sinusoidal gratings of different spatial frequency, contrast, and luminance generated by a specialized video card and presented on a 21-in. computer display suitably linearized by gamma correction. Results. ERG assessments indicated no significant deficit in retinal physiology in Ts65Dn mice compared with euploid control mice. The Ts65Dn mice were found to exhibit deficits in luminance threshold, spatial resolution, and contrast threshold, compared with the euploid control mice. The behavioral counterparts of these parameters are luminance sensitivity, visual acuity, and the inverse of contrast sensitivity, respectively. Conclusions. DS includes various phenotypes associated with the visual system, including deficits in visual acuity, accommodation, and contrast sensitivity. The present study provides electrophysiological evidence of visual deficits in Ts65Dn mice that are similar to those reported in persons with DS. These findings strengthen the role of the Ts65Dn mouse as a model for DS. Also, given the historical assumption of integrity of the visual system in most behavioral assessments of Ts65Dn mice, such as the hidden-platform component of the Morris water maze, the visual deficits described herein may represent a significant confounding factor in the interpretation of results from such experiments. PMID:20130276

  9. Rapid generation of a mouse model for Middle East respiratory syndrome

    PubMed Central

    Zhao, Jincun; Li, Kun; Wohlford-Lenane, Christine; Agnihothram, Sudhakar S.; Fett, Craig; Zhao, Jingxian; Gale, Michael J.; Baric, Ralph S.; Enjuanes, Luis; Gallagher, Tom; McCray, Paul B.; Perlman, Stanley

    2014-01-01

    In this era of continued emergence of zoonotic virus infections, the rapid development of rodent models represents a critical barrier to public health preparedness, including the testing of antivirus therapy and vaccines. The Middle East respiratory syndrome coronavirus (MERS-CoV) was recently identified as the causative agent of a severe pneumonia. Given the ability of coronavirus to rapidly adapt to new hosts, a major public health concern is that MERS-CoV will further adapt to replication in humans, triggering a pandemic. No small-animal model for this infection is currently available, but studies suggest that virus entry factors can confer virus susceptibility. Here, we show that mice were sensitized to MERS-CoV infection by prior transduction with adenoviral vectors expressing the human host-cell receptor dipeptidyl peptidase 4. Mice developed a pneumonia characterized by extensive inflammatory-cell infiltration with virus clearance occurring 6–8 d after infection. Clinical disease and histopathological changes were more severe in the absence of type-I IFN signaling whereas the T-cell response was required for virus clearance. Using these mice, we demonstrated the efficacy of a therapeutic intervention (poly I:C) and a potential vaccine [Venezuelan equine encephalitis replicon particles expressing MERS-CoV spike protein]. We also found little protective cross-reactivity between MERS-CoV and the severe acute respiratory syndrome-CoV. Our results demonstrate that this system will be useful for MERS-CoV studies and for the rapid development of relevant animal models for emerging respiratory viral infections. PMID:24599590

  10. Histochemical and cellular changes accompanying the appearance of lung fibrosis in an experimental mouse model for Hermansky Pudlak syndrome

    PubMed Central

    Lyerla, Timothy

    2010-01-01

    Hermansky Pudlak syndrome (HPS) is a heterogeneous recessive genetic disease with a tendency to develop lung fibrosis with aging. A mouse strain with two mutant HPS genes affecting separate vesicle trafficking pathways, C57BL/6-Hps1ep-Ap3b1pe, exhibits severe lung abnormalities at young ages, including enlarged alveolar type II (ATII) cells with giant lamellar bodies and foamy alveolar macrophages (AMs), which are readily identified histologically. In this study, the appearance of lung fibrosis in older animals was studied using classical histological and biochemical methods. The HPS double mutant mice, but not Chediak Higashi syndrome (C57BL/6-Lystbg-J-J, CHS) or C57BL/6J black control (WT) mice, were found to develop lung fibrosis at about 17 months of age using Masson trichrome staining, which was confirmed by hydroxyproline analysis. TGF β1 levels were elevated in bronchial alveolar lavage samples at all ages tested in the double mutant, but not WT or CHS mice, indicative of a prefibrotic condition in this experimental strain; and AMs were highly positive for this cytokine using immunohistochemistry staining. Prosurfactant protein C staining for ATII cells showed redistribution and dysmorphism of these cells with aging, but there was no evidence for epithelial-mesenchymal transition of ATII cells by dual staining for prosurfactant C protein and α-smooth muscle actin. This investigation showed that the HPS double mutant mouse strain develops interstitial pneumonia (HPSIP) past 1 year of age, which may be initiated by abnormal ATII cells and exacerbated by AM activation. With prominent prefibrotic abnormalities, this double mutant may serve as a model for interventive therapy in HPS. PMID:20603711

  11. A mouse model for the Carney complex tumor syndrome develops neoplasia in cyclic AMP-responsive tissues.

    PubMed

    Kirschner, Lawrence S; Kusewitt, Donna F; Matyakhina, Ludmila; Towns, William H; Carney, J Aidan; Westphal, Heiner; Stratakis, Constantine A

    2005-06-01

    Carney complex is an autosomal dominant neoplasia syndrome characterized by spotty skin pigmentation, myxomatosis, endocrine tumors, and schwannomas. This condition may be caused by inactivating mutations in PRKAR1A, the gene encoding the type 1A regulatory subunit of protein kinase A. To better understand the mechanism by which PRKAR1A mutations cause disease, we have developed conventional and conditional null alleles for Prkar1a in the mouse. Prkar1a(+/-) mice developed nonpigmented schwannomas and fibro-osseous bone lesions beginning at approximately 6 months of age. Although genotype-specific cardiac and adrenal lesions were not seen, benign and malignant thyroid neoplasias were observed in older mice. This spectrum of tumors overlaps that seen in Carney complex patients, confirming the validity of this mouse model. Genetic analysis indicated that allelic loss occurred in a subset of tumor cells, suggesting that complete loss of Prkar1a plays a key role in tumorigenesis. Similarly, tissue-specific ablation of Prkar1a from a subset of facial neural crest cells caused the formation of schwannomas with divergent differentiation. These observations confirm the identity of PRKAR1A as a tumor suppressor gene with specific importance to cyclic AMP-responsive tissues and suggest that these mice may be valuable tools not only for understanding endocrine tumorigenesis but also for understanding inherited predispositions for schwannoma formation. PMID:15930266

  12. Disruption of MeCP2 attenuates circadian rhythm in CRISPR/Cas9-based Rett syndrome model mouse.

    PubMed

    Tsuchiya, Yoshiki; Minami, Yoichi; Umemura, Yasuhiro; Watanabe, Hitomi; Ono, Daisuke; Nakamura, Wataru; Takahashi, Tomoyuki; Honma, Sato; Kondoh, Gen; Matsuishi, Toyojiro; Yagita, Kazuhiro

    2015-12-01

    Methyl-CpG-binding protein 2 (Mecp2) is an X-linked gene encoding a methylated DNA-binding nuclear protein which regulates transcriptional activity. The mutation of MECP2 in humans is associated with Rett syndrome (RTT), a neurodevelopmental disorder. Patients with RTT frequently show abnormal sleep patterns and sleep-associated problems, in addition to autistic symptoms, raising the possibility of circadian clock dysfunction in RTT. In this study, we investigated circadian clock function in Mecp2-deficient mice. We successfully generated both male and female Mecp2-deficient mice on the wild-type C57BL/6 background and PER2(Luciferase) (PER2(Luc)) knock-in background using the clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9 system. Generated Mecp2-deficient mice recapitulated reduced activity in mouse models of RTT, and their activity rhythms were diminished in constant dark conditions. Furthermore, real-time bioluminescence imaging showed that the amplitude of PER2(Luc)-driven circadian oscillation was significantly attenuated in Mecp2-deficient SCN neurons. On the other hand, in vitro circadian rhythm development assay using Mecp2-deficient mouse embryonic stem cells (ESCs) did not show amplitude changes of PER2(Luc) bioluminescence rhythms. Together, these results show that Mecp2 deficiency abrogates the circadian pacemaking ability of the SCN, which may be a therapeutic target to treat the sleep problems of patients with RTT. PMID:26456390

  13. Specific age-related molecular alterations in the cerebellum of Down syndrome mouse models.

    PubMed

    Créau, Nicole; Cabet, Eva; Daubigney, Fabrice; Souchet, Benoit; Bennaï, Soumia; Delabar, Jean

    2016-09-01

    Down syndrome, or trisomy 21, has been modeled with various trisomic and transgenic mice to help understand the consequences of an altered gene dosage in brain development and function. Though Down syndrome has been associated with premature aging, little is known about the molecular and cellular alterations that target brain function. To help identify alterations at specific ages, we analyzed the cerebellum of Ts1Cje mice, trisomic for 77 HSA21 orthologs, at three ages-young (4 months), middle-age (12 months), and old (17 months)-compared to age-matched controls. Quantification of neuronal and glial markers (n=11) revealed increases in GFAP, with an age effect, and S100B, with age and genotype effects. The genotype effect on S100B with age was unexpected as Ts1Cje has only two copies of the S100b gene. Interestingly, the different increase in GFAP observed between Ts1Cje (trisomic segment includes Pcp4 gene) and controls was magnified in TgPCP4 mice (1 extra copy of the human PCP4 gene) at the same age. S100B increase was not found in the TgPCP4 confirming a difference of regulation with aging for GFAP and S100B and excluding the calcium signaling regulator, Pcp4, as a potential candidate for increase of S100B in the Ts1Cje. To understand these differences, comparison of GFAP and S100B immunostainings at young and middle-age were performed. Immunohistochemical detection of differences in GFAP and S100B localization with aging implicate S100B+ oligodendrocytes as a new phenotypic target in this specific aging process. PMID:27297494

  14. Abnormalities of cell packing density and dendritic complexity in the MeCP2 A140V mouse model of Rett syndrome/X-linked mental retardation

    PubMed Central

    2010-01-01

    Background Rett syndrome (RTT), a common cause of mental retardation in girls, is associated with mutations in the MECP2 gene. Most human cases of MECP2 mutation in girls result in classical or variant forms of RTT. When these same mutations occur in males, they often present as severe neonatal encephalopathy. However, some MECP2 mutations can also lead to diseases characterized as mental retardation syndromes, particularly in boys. One of these mutations, A140V, is a common, recurring missense mutation accounting for about 0.6% of all MeCP2 mutations and ranking 21st by frequency. It has been described in familial X-linked mental retardation (XLMR), PPM- X syndrome (Parkinsonism, Pyramidal signs, Macroorchidism, X-linked mental retardation) and in other neuropsychiatric syndromes. Interestingly, this mutation has been reported to preserve the methyl-CpG binding function of the MeCP2 protein while compromising its ability to bind to the mental retardation associated protein ATRX. Results We report the construction and initial characterization of a mouse model expressing the A140V MeCP2 mutation. These initial descriptive studies in male hemizygous mice have revealed brain abnormalities seen in both RTT and mental retardation. The abnormalities found include increases in cell packing density in the brain and a significant reduction in the complexity of neuronal dendritic branching. In contrast to some MeCP2 mutation mouse models, the A140V mouse has an apparently normal lifespan and normal weight gain patterns with no obvious seizures, tremors, breathing difficulties or kyphosis. Conclusion We have identified various neurological abnormalities in this mouse model of Rett syndrome/X-linked mental retardation which may help to elucidate the manner in which MECP2 mutations cause neuronal changes resulting in mental retardation without the confounding effects of seizures, chronic hypoventilation, or other Rett syndrome associated symptoms. PMID:20163734

  15. Abnormal intrinsic dynamics of dendritic spines in a fragile X syndrome mouse model in vivo

    PubMed Central

    Nagaoka, Akira; Takehara, Hiroaki; Hayashi-Takagi, Akiko; Noguchi, Jun; Ishii, Kazuhiko; Shirai, Fukutoshi; Yagishita, Sho; Akagi, Takanori; Ichiki, Takanori; Kasai, Haruo

    2016-01-01

    Dendritic spine generation and elimination play an important role in learning and memory, the dynamics of which have been examined within the neocortex in vivo. Spine turnover has also been detected in the absence of specific learning tasks, and is frequently exaggerated in animal models of autistic spectrum disorder (ASD). The present study aimed to examine whether the baseline rate of spine turnover was activity-dependent. This was achieved using a microfluidic brain interface and open-dura surgery, with the goal of abolishing neuronal Ca2+ signaling in the visual cortex of wild-type mice and rodent models of fragile X syndrome (Fmr1 knockout [KO]). In wild-type and Fmr1 KO mice, the majority of baseline turnover was found to be activity-independent. Accordingly, the application of matrix metalloproteinase-9 inhibitors selectively restored the abnormal spine dynamics observed in Fmr1 KO mice, without affecting the intrinsic dynamics of spine turnover in wild-type mice. Such findings indicate that the baseline turnover of dendritic spines is mediated by activity-independent intrinsic dynamics. Furthermore, these results suggest that the targeting of abnormal intrinsic dynamics might pose a novel therapy for ASD. PMID:27221801

  16. Abnormal intrinsic dynamics of dendritic spines in a fragile X syndrome mouse model in vivo.

    PubMed

    Nagaoka, Akira; Takehara, Hiroaki; Hayashi-Takagi, Akiko; Noguchi, Jun; Ishii, Kazuhiko; Shirai, Fukutoshi; Yagishita, Sho; Akagi, Takanori; Ichiki, Takanori; Kasai, Haruo

    2016-01-01

    Dendritic spine generation and elimination play an important role in learning and memory, the dynamics of which have been examined within the neocortex in vivo. Spine turnover has also been detected in the absence of specific learning tasks, and is frequently exaggerated in animal models of autistic spectrum disorder (ASD). The present study aimed to examine whether the baseline rate of spine turnover was activity-dependent. This was achieved using a microfluidic brain interface and open-dura surgery, with the goal of abolishing neuronal Ca(2+) signaling in the visual cortex of wild-type mice and rodent models of fragile X syndrome (Fmr1 knockout [KO]). In wild-type and Fmr1 KO mice, the majority of baseline turnover was found to be activity-independent. Accordingly, the application of matrix metalloproteinase-9 inhibitors selectively restored the abnormal spine dynamics observed in Fmr1 KO mice, without affecting the intrinsic dynamics of spine turnover in wild-type mice. Such findings indicate that the baseline turnover of dendritic spines is mediated by activity-independent intrinsic dynamics. Furthermore, these results suggest that the targeting of abnormal intrinsic dynamics might pose a novel therapy for ASD. PMID:27221801

  17. Pathway-specific dopaminergic deficits in a mouse model of Angelman syndrome

    PubMed Central

    Riday, Thorfinn T.; Dankoski, Elyse C.; Krouse, Michael C.; Fish, Eric W.; Walsh, Paul L.; Han, Ji Eun; Hodge, Clyde W.; Wightman, R. Mark; Philpot, Benjamin D.; Malanga, C.J.

    2012-01-01

    Angelman syndrome (AS) is a neurodevelopmental disorder caused by maternal deletions or mutations of the ubiquitin ligase E3A (UBE3A) allele and characterized by minimal verbal communication, seizures, and disorders of voluntary movement. Previous studies have suggested that abnormal dopamine neurotransmission may underlie some of these deficits, but no effective treatment currently exists for the core features of AS. A clinical trial of levodopa (l-DOPA) in AS is ongoing, although the underlying rationale for this treatment strategy has not yet been thoroughly examined in preclinical models. We found that AS model mice lacking maternal Ube3a (Ube3am–/p+ mice) exhibit behavioral deficits that correlated with abnormal dopamine signaling. These deficits were not due to loss of dopaminergic neurons or impaired dopamine synthesis. Unexpectedly, Ube3am–/p+ mice exhibited increased dopamine release in the mesolimbic pathway while also exhibiting a decrease in dopamine release in the nigrostriatal pathway, as measured with fast-scan cyclic voltammetry. These findings demonstrate the complex effects of UBE3A loss on dopamine signaling in subcortical motor pathways that may inform ongoing clinical trials of l-DOPA therapy in patients with AS. PMID:23143301

  18. Using Mouse and Zebrafish Models to Understand the Etiology of Developmental Defects in Cornelia de Lange Syndrome

    PubMed Central

    KAWAUCHI, SHIMAKO; SANTOS, ROSAYSELA; MUTO, AKIHIKO; LOPEZ-BURKS, MARTHA E.; SCHILLING, THOMAS F.; LANDER, ARTHUR D.; CALOF, ANNE L.

    2016-01-01

    Cornelia de Lange Syndrome (CdLS) is a multisystem birth defects disorder that affects every tissue and organ system in the body. Understanding the factors that contribute to the origins, prevalence, and severity of these developmental defects provides the most direct approach for developing screens and potential treatments for individuals with CdLS. Since the majority of cases of CdLS are caused by haploinsufficiency for NIPBL (Nipped-B-like, which encodes a cohesin-associated protein), we have developed mouse and zebrafish models of CdLS by using molecular genetic tools to create Nipbl-deficient mice and zebrafish (Nipbl+/− mice, zebrafish nipbl morphants). Studies of these vertebrate animal models have yielded novel insights into the developmental etiology and genes/gene pathways that contribute to CdLS-associated birth defects, particularly defects of the gut, heart, craniofacial structures, nervous system, and limbs. Studies of these mouse and zebrafish CdLS models have helped clarify how deficiency for NIPBL, a protein that associates with cohesin and other transcriptional regulators in the nucleus, affects processes important to the emergence of the structural and physiological birth defects observed in CdLS: NIPBL exerts chromosome position-specific effects on gene expression; it influences long-range interactions between different regulatory elements of genes; and it regulates combinatorial and synergistic actions of genes in developing tissues. Our current understanding is that CdLS should be considered as not only a cohesinopathy, but also a “transcriptomopathy,” that is, a disease whose underlying etiology is the global dysregulation of gene expression throughout the organism. PMID:27120001

  19. Using mouse and zebrafish models to understand the etiology of developmental defects in Cornelia de Lange Syndrome.

    PubMed

    Kawauchi, Shimako; Santos, Rosaysela; Muto, Akihiko; Lopez-Burks, Martha E; Schilling, Thomas F; Lander, Arthur D; Calof, Anne L

    2016-06-01

    Cornelia de Lange Syndrome (CdLS) is a multisystem birth defects disorder that affects every tissue and organ system in the body. Understanding the factors that contribute to the origins, prevalence, and severity of these developmental defects provides the most direct approach for developing screens and potential treatments for individuals with CdLS. Since the majority of cases of CdLS are caused by haploinsufficiency for NIPBL (Nipped-B-like, which encodes a cohesin-associated protein), we have developed mouse and zebrafish models of CdLS by using molecular genetic tools to create Nipbl-deficient mice and zebrafish (Nipbl(+/-) mice, zebrafish nipbl morphants). Studies of these vertebrate animal models have yielded novel insights into the developmental etiology and genes/gene pathways that contribute to CdLS-associated birth defects, particularly defects of the gut, heart, craniofacial structures, nervous system, and limbs. Studies of these mouse and zebrafish CdLS models have helped clarify how deficiency for NIPBL, a protein that associates with cohesin and other transcriptional regulators in the nucleus, affects processes important to the emergence of the structural and physiological birth defects observed in CdLS: NIPBL exerts chromosome position-specific effects on gene expression; it influences long-range interactions between different regulatory elements of genes; and it regulates combinatorial and synergistic actions of genes in developing tissues. Our current understanding is that CdLS should be considered as not only a cohesinopathy, but also a "transcriptomopathy," that is, a disease whose underlying etiology is the global dysregulation of gene expression throughout the organism. © 2016 Wiley Periodicals, Inc. PMID:27120001

  20. Autoimmunity contributes to nociceptive sensitization in a mouse model of complex regional pain syndrome.

    PubMed

    Li, Wen-Wu; Guo, Tian-Zhi; Shi, Xiaoyou; Czirr, Eva; Stan, Trisha; Sahbaie, Peyman; Wyss-Coray, Tony; Kingery, Wade S; Clark, J David

    2014-11-01

    Complex regional pain syndrome (CRPS) is a painful, disabling, chronic condition whose etiology remains poorly understood. The recent suggestion that immunological mechanisms may underlie CRPS provides an entirely novel framework in which to study the condition and consider new approaches to treatment. Using a murine fracture/cast model of CRPS, we studied the effects of B-cell depletion using anti-CD20 antibodies or by performing experiments in genetically B-cell-deficient (μMT) mice. We observed that mice treated with anti-CD20 developed attenuated vascular and nociceptive CRPS-like changes after tibial fracture and 3 weeks of cast immobilization. In mice with established CRPS-like changes, the depletion of CD-20+ cells slowly reversed nociceptive sensitization. Correspondingly, μMT mice, deficient in producing immunoglobulin M (IgM), failed to fully develop CRPS-like changes after fracture and casting. Depletion of CD20+ cells had no detectable effects on nociceptive sensitization in a model of postoperative incisional pain, however. Immunohistochemical experiments showed that CD20+ cells accumulate near the healing fracture but few such cells collect in skin or sciatic nerves. On the other hand, IgM-containing immune complexes were deposited in skin and sciatic nerve after fracture in wild-type, but not in μMT fracture/cast, mice. Additional experiments demonstrated that complement system activation and deposition of membrane attack complexes were partially blocked by anti-CD20+ treatment. Collectively, our results suggest that CD20-positive B cells produce antibodies that ultimately support the CRPS-like changes in the murine fracture/cast model. Therapies directed at reducing B-cell activity may be of use in treating patients with CRPS. PMID:25218828

  1. Autoimmunity contributes to nociceptive sensitization in a mouse model of complex regional pain syndrome

    PubMed Central

    Li, Wen-Wu; Guo, Tian-Zhi; Shi, Xiaoyou; Czirr, Eva; Stan, Trisha; Sahbaie, Peyman; Wyss-Coray, Tony; Kingery, Wade S.; Clark, J. David

    2014-01-01

    Complex regional pain syndrome (CRPS) is a painful, disabling, chronic condition whose etiology remains poorly understood. The recent suggestion that immunological mechanisms may underlie CRPS provides an entirely novel framework in which to study the condition and consider new approaches to treatment. Using a murine fracture/cast model of CRPS, we studied the effects of B-cell depletion using anti-CD20 antibodies or by performing experiments in genetically B-cell-deficient (µMT) mice. We observed that mice treated with anti-CD20 developed attenuated vascular and nociceptive CRPS-like changes after tibial fracture and 3 weeks of cast immobilization. In mice with established CRPS-like changes, the depletion of CD-20+ cells slowly reversed nociceptive sensitization. Correspondingly, µMT mice, deficient in producing immunoglobulin M (IgM), failed to fully develop CRPS-like changes after fracture and casting. Depletion of CD20+ cells had no detectable effects on nociceptive sensitization in a model of postoperative incisional pain, however. Immunohistochemical experiments showed that CD20+ cells accumulate near the healing fracture but few such cells collect in skin or sciatic nerves. On the other hand, IgM-containing immune complexes were deposited in skin and sciatic nerve after fracture in wild-type, but not in µMT fracture/cast, mice. Additional experiments demonstrated that complement system activation and deposition of membrane attack complexes were partially blocked by anti-CD20+ treatment. Collectively, our results suggest that CD20-positive B cells produce antibodies that ultimately support the CRPS-like changes in the murine fracture/cast model. Therapies directed at reducing B-cell activity may be of use in treating patients with CRPS. PMID:25218828

  2. Hippocampal dysfunction in the Euchromatin histone methyltransferase 1 heterozygous knockout mouse model for Kleefstra syndrome.

    PubMed

    Balemans, Monique C M; Kasri, Nael Nadif; Kopanitsa, Maksym V; Afinowi, Nurudeen O; Ramakers, Ger; Peters, Theo A; Beynon, Andy J; Janssen, Sanne M; van Summeren, Rik C J; Eeftens, Jorine M; Eikelenboom, Nathalie; Benevento, Marco; Tachibana, Makoto; Shinkai, Yoichi; Kleefstra, Tjitske; van Bokhoven, Hans; Van der Zee, Catharina E E M

    2013-03-01

    Euchromatin histone methyltransferase 1 (EHMT1) is a highly conserved protein that catalyzes mono- and dimethylation of histone H3 lysine 9, thereby epigenetically regulating transcription. Kleefstra syndrome (KS), is caused by haploinsufficiency of the EHMT1 gene, and is an example of an emerging group of intellectual disability (ID) disorders caused by genes encoding epigenetic regulators of neuronal gene activity. Little is known about the mechanisms underlying this disorder, prompting us to study the Euchromatin histone methyltransferase 1 heterozygous knockout (Ehmt1(+/-)) mice as a model for KS. In agreement with the cognitive disturbances observed in patients with KS, we detected deficits in fear extinction learning and both novel and spatial object recognition in Ehmt1(+/-) mice. These learning and memory deficits were associated with a significant reduction in dendritic arborization and the number of mature spines in hippocampal CA1 pyramidal neurons of Ehmt1(+/-) mice. In-depth analysis of the electrophysiological properties of CA3-CA1 synapses revealed no differences in basal synaptic transmission or theta-burst induced long-term potentiation (LTP). However, paired-pulse facilitation (PPF) was significantly increased in Ehmt1(+/-) neurons, pointing to a potential deficiency in presynaptic neurotransmitter release. Accordingly, a reduction in the frequency of miniature excitatory post-synaptic currents (mEPSCs) was observed in Ehmt1(+/-) neurons. These data demonstrate that Ehmt1 haploinsufficiency in mice leads to learning deficits and synaptic dysfunction, providing a possible mechanism for the ID phenotype in patients with KS. PMID:23175442

  3. Early environmental therapy rescues brain development in a mouse model of Down syndrome.

    PubMed

    Begenisic, Tatjana; Sansevero, Gabriele; Baroncelli, Laura; Cioni, Giovanni; Sale, Alessandro

    2015-10-01

    Down syndrome (DS), the most common genetic disorder associated with intellectual disabilities, is an untreatable condition characterized by a number of developmental defects and permanent deficits in the adulthood. Ts65Dn mice, the major animal model for DS, display severe cognitive and synaptic plasticity defects closely resembling the human phenotype. Here, we employed a multidisciplinary approach to investigate, for the first time in developing Ts65Dn mice, the effects elicited by early environmental enrichment (EE) on brain maturation and function. We report that exposure to EE resulted in a robust increase in maternal care levels displayed by Ts65Dn mothers and led to a normalization of declarative memory abilities and hippocampal plasticity in trisomic offspring. The positive effects of EE on Ts65Dn phenotype were not limited to the cognitive domain, but also included a rescue of visual system maturation. The beneficial EE effects were accompanied by increased BDNF and correction of over-expression of the GABA vesicular transporter vGAT. These findings highlight the beneficial impact of early environmental stimuli and their potential for application in the treatment of major functional deficits in children with DS. PMID:26244989

  4. Protein dynamics associated with failed and rescued learning in the Ts65Dn mouse model of Down syndrome.

    PubMed

    Ahmed, Md Mahiuddin; Dhanasekaran, A Ranjitha; Block, Aaron; Tong, Suhong; Costa, Alberto C S; Stasko, Melissa; Gardiner, Katheleen J

    2015-01-01

    Down syndrome (DS) is caused by an extra copy of human chromosome 21 (Hsa21). Although it is the most common genetic cause of intellectual disability (ID), there are, as yet, no effective pharmacotherapies. The Ts65Dn mouse model of DS is trisomic for orthologs of ∼55% of Hsa21 classical protein coding genes. These mice display many features relevant to those seen in DS, including deficits in learning and memory (L/M) tasks requiring a functional hippocampus. Recently, the N-methyl-D-aspartate (NMDA) receptor antagonist, memantine, was shown to rescue performance of the Ts65Dn in several L/M tasks. These studies, however, have not been accompanied by molecular analyses. In previous work, we described changes in protein expression induced in hippocampus and cortex in control mice after exposure to context fear conditioning (CFC), with and without memantine treatment. Here, we extend this analysis to Ts65Dn mice, measuring levels of 85 proteins/protein modifications, including components of MAP kinase and MTOR pathways, and subunits of NMDA receptors, in cortex and hippocampus of Ts65Dn mice after failed learning in CFC and after learning was rescued by memantine. We show that, compared with wild type littermate controls, (i) of the dynamic responses seen in control mice in normal learning, >40% also occur in Ts65Dn in failed learning or are compensated by baseline abnormalities, and thus are considered necessary but not sufficient for successful learning, and (ii) treatment with memantine does not in general normalize the initial protein levels but instead induces direct and indirect responses in approximately half the proteins measured and results in normalization of the endpoint protein levels. Together, these datasets provide a first view of the complexities associated with pharmacological rescue of learning in the Ts65Dn. Extending such studies to additional drugs and mouse models of DS will aid in identifying pharmacotherapies for effective clinical trials

  5. Calorie seeking, but not hedonic response, contributes to hyperphagia in a mouse model for Prader-Willi syndrome.

    PubMed

    Davies, Jennifer R; Humby, Trevor; Dwyer, Dominic M; Garfield, Alastair S; Furby, Hannah; Wilkinson, Lawrence S; Wells, Timothy; Isles, Anthony R

    2015-08-01

    Prader-Willi syndrome (PWS) is a neurodevelopmental disorder caused by deletion or inactivation of paternally expressed imprinted genes on human chromosome 15q11-q13, the most recognised feature of which is hyperphagia. This is thought to arise as a consequence of abnormalities in both the physiological drive for food and the rewarding properties of food. Although a number of mouse models for PWS exist, the underlying variables dictating maladaptive feeding remain unknown. Here, feeding behaviour in a mouse model in which the imprinting centre (IC) of the syntenic PWS interval has been deleted (PWS(ICdel) mice) is characterised. It is demonstrated that PWS(ICdel) mice show hyperghrelinaemia and increased consumption of food both following overnight fasting and when made more palatable with sucrose. However, hyperphagia in PWS(ICdel) mice was not accompanied by any changes in reactivity to the hedonic properties of palatable food (sucrose or saccharin), as measured by lick-cluster size. Nevertheless, overall consumption by PWS(ICdel) mice for non-caloric saccharin in the licking test was significantly reduced. Combined with converging findings from a continuous reinforcement schedule, these data indicate that PWS(ICdel) mice show a marked heightened sensitivity to the calorific value of food. Overall, these data indicate that any impact of the rewarding properties of food on the hyperphagia seen in PWS(ICdel) mice is driven primarily by calorie content and is unlikely to involve hedonic processes. This has important implications for understanding the neural systems underlying the feeding phenotype of PWS and the contribution of imprinted genes to abnormal feeding behaviour more generally. PMID:26040449

  6. Altered Intrathalamic GABAA Neurotransmission in a Mouse Model of a Human Genetic Absence Epilepsy Syndrome

    PubMed Central

    Zhou, Chengwen; Ding, Li; Deel, M. Elizabeth; Ferrick, Elizabeth A.; Emeson, Ronald B.; Gallagher, Martin J.

    2014-01-01

    We previously demonstrated that heterozygous deletion of Gabra1, the mouse homolog of the human absence epilepsy gene that encodes the GABAA receptor (GABAAR) α1 subunit, causes absence seizures. We showed that cortex partially compensates for this deletion by increasing the cell surface expression of residual α1 subunit and by increasing α3 subunit expression. Absence seizures also involve two thalamic nuclei: the ventrobasal (VB) nucleus, which expresses only the α1 and α4 subtypes of GABAAR α subunits, and the reticular (nRT) nucleus, which expresses only the α3 subunit subtype. Here, we found that, unlike cortex, VB exhibited significantly reduced total and synaptic α1 subunit expression. In addition, heterozygous α1 subunit deletion substantially reduced miniature inhibitory postsynaptic current (mIPSC) peak amplitudes and frequency in VB. However, there was no change in expression of the extrasynaptic α4 or δ subunits in VB and, unlike other models of absence epilepsy, no change in tonic GABAAR currents. Although heterozygous α1 subunit knockout increased α3 subunit expression in medial thalamic nuclei, it did not alter α3 subunit expression in nRT. However, it did enlarge the presynaptic vesicular inhibitory amino acid transporter puncta and lengthen the time constant of mIPSC decay in nRT. We conclude that increased tonic GABAA currents are not necessary for absence seizures. In addition, heterozygous loss of α1 subunit disinhibits VB by substantially reducing phasic GABAergic currents and surprisingly, it also increases nRT inhibition by prolonging phasic currents. The increased inhibition in nRT likely represents a partial compensation that helps reduce absence seizures. PMID:25447232

  7. Altered intrathalamic GABAA neurotransmission in a mouse model of a human genetic absence epilepsy syndrome.

    PubMed

    Zhou, Chengwen; Ding, Li; Deel, M Elizabeth; Ferrick, Elizabeth A; Emeson, Ronald B; Gallagher, Martin J

    2015-01-01

    We previously demonstrated that heterozygous deletion of Gabra1, the mouse homolog of the human absence epilepsy gene that encodes the GABAA receptor (GABAAR) α1 subunit, causes absence seizures. We showed that cortex partially compensates for this deletion by increasing the cell surface expression of residual α1 subunit and by increasing α3 subunit expression. Absence seizures also involve two thalamic nuclei: the ventrobasal (VB) nucleus, which expresses only the α1 and α4 subtypes of GABAAR α subunits, and the reticular (nRT) nucleus, which expresses only the α3 subunit subtype. Here, we found that, unlike cortex, VB exhibited significantly reduced total and synaptic α1 subunit expression. In addition, heterozygous α1 subunit deletion substantially reduced miniature inhibitory postsynaptic current (mIPSC) peak amplitudes and frequency in VB. However, there was no change in the expression of the extrasynaptic α4 or δ subunits in VB and, unlike other models of absence epilepsy, no change in tonic GABAAR currents. Although heterozygous α1 subunit knockout increased α3 subunit expression in medial thalamic nuclei, it did not alter α3 subunit expression in nRT. However, it did enlarge the presynaptic vesicular inhibitory amino acid transporter puncta and lengthen the time constant of mIPSC decay in nRT. We conclude that increased tonic GABAA currents are not necessary for absence seizures. In addition, heterozygous loss of α1 subunit disinhibits VB by substantially reducing phasic GABAergic currents and surprisingly, it also increases nRT inhibition by prolonging phasic currents. The increased inhibition in nRT likely represents a partial compensation that helps reduce absence seizures. PMID:25447232

  8. Designer receptors enhance memory in a mouse model of Down syndrome.

    PubMed

    Fortress, Ashley M; Hamlett, Eric D; Vazey, Elena M; Aston-Jones, Gary; Cass, Wayne A; Boger, Heather A; Granholm, Ann-Charlotte E

    2015-01-28

    Designer receptors exclusively activated by designer drugs (DREADDs) are novel and powerful tools to investigate discrete neuronal populations in the brain. We have used DREADDs to stimulate degenerating neurons in a Down syndrome (DS) model, Ts65Dn mice. Individuals with DS develop Alzheimer's disease (AD) neuropathology and have elevated risk for dementia starting in their 30s and 40s. Individuals with DS often exhibit working memory deficits coupled with degeneration of the locus coeruleus (LC) norepinephrine (NE) neurons. It is thought that LC degeneration precedes other AD-related neuronal loss, and LC noradrenergic integrity is important for executive function, working memory, and attention. Previous studies have shown that LC-enhancing drugs can slow the progression of AD pathology, including amyloid aggregation, oxidative stress, and inflammation. We have shown that LC degeneration in Ts65Dn mice leads to exaggerated memory loss and neuronal degeneration. We used a DREADD, hM3Dq, administered via adeno-associated virus into the LC under a synthetic promoter, PRSx8, to selectively stimulate LC neurons by exogenous administration of the inert DREADD ligand clozapine-N-oxide. DREADD stimulation of LC-NE enhanced performance in a novel object recognition task and reduced hyperactivity in Ts65Dn mice, without significant behavioral effects in controls. To confirm that the noradrenergic transmitter system was responsible for the enhanced memory function, the NE prodrug l-threo-dihydroxyphenylserine was administered in Ts65Dn and normosomic littermate control mice, and produced similar behavioral results. Thus, NE stimulation may prevent memory loss in Ts65Dn mice, and may hold promise for treatment in individuals with DS and dementia. PMID:25632113

  9. Histopathological characteristics of glutamine synthetase-positive hepatic tumor lesions in a mouse model of spontaneous metabolic syndrome (TSOD mouse)

    PubMed Central

    Takahashi, Tetsuyuki; Nishida, Takeshi; Baba, Hayato; Hatta, Hideki; Imura, Johji; Sutoh, Mitsuko; Toyohara, Syunji; Hokao, Ryoji; Watanabe, Syunsuke; Ogawa, Hirohisa; Uehara, Hisanori; Tsuneyama, Koichi

    2016-01-01

    We previously reported that Tsumura-Suzuki obese diabetic (TSOD) mice, a polygenic model of spontaneous type 2 diabetes, is a valuable model of hepatic carcinogenesis via non-alcoholic fatty liver disease (NAFLD) and non-alcoholic steatohepatitis (NASH). One of the characteristics of tumors in these mice is the diffuse expression of glutamine synthetase (GS), which is a diagnostic marker for hepatocellular carcinoma (HCC). In this study, we performed detailed histopathological examinations and found that GS expression was diffusely positive in >70% of the hepatic tumors from 15-month-old male TSOD mice. Translocation of β-catenin into nuclei with enhanced membranous expression also occurred in GS-positive tumors. Small lesions (<1 mm) in GS-positive cases exhibited dysplastic nodules, with severe nuclear atypia, whereas large lesions (>3 mm) bore the characteristics of human HCC, exhibiting nuclear and structural atypia with invasive growth. By contrast, the majority of GS-negative tumors were hepatocellular adenomas with advanced fatty change and low nuclear grade. In GS-negative tumors, loss of liver fatty acid-binding protein expression was observed. These results suggest that the histological characteristics of GS-positive hepatic tumors in TSOD mice resemble human HCC; thus, this model may be a useful tool in translational research targeting the NAFLD/NASH-HCC sequence. PMID:27446562

  10. Generation and characterization of a mouse model of the metabolic syndrome: apolipoprotein E and aromatase double knockout mice.

    PubMed

    Scott, Nicola J A; Cameron, Vicky A; Raudsepp, Sara; Lewis, Lynley K; Simpson, Evan R; Richards, A Mark; Ellmers, Leigh J

    2012-03-01

    The aim of this study was to create a comprehensive mouse model of the metabolic syndrome by crossing aromatase-deficient (ArKO) mice with apolipoprotein E-deficient (ApoE(-/-)) mice. Successive crossbreeding of ArKO with ApoE(-/-)-deficient mice generated double knockout, MetS-Tg mice. The phenotypic characteristics of the MetS-Tg mice were assessed at 3, 6, and 12 mo of age and compared with age- and sex-matched wild-type (WT) controls. Blood pressure and heart rate were recorded by a noninvasive, computerized tail-cuff system. Oral glucose and intraperitoneal insulin tolerance tests were performed. Serum cholesterol levels were measured by a combined quantitative colorimetric assay. Plasma adiponectin, C-reactive protein (CRP), insulin, interleukin-6 (IL-6), leptin, resistin, and tumor necrosis factor-α (TNF-α) were measured by multiplexed ELISA. MetS-Tg mice displayed significantly increased body weight, central obesity, and elevated blood pressure at all three ages compared with WT mice. Elevated serum cholesterol was associated with higher triglycerides and LDL/VLDL cholesterol particles and was accompanied by a decrease in HDL and histological evidence of fatty liver. MetS-Tg mice of all ages showed impaired glucose tolerance. At 12 mo, MetS-Tg mice had elevated plasma levels of CRP, IL-6, leptin, and TNF-α, but resistin levels were largely unchanged. We now report that this combination of gene knockouts produces a novel strain of mice that display the diverse clinical features of the metabolic syndrome, including central obesity, progressive hypertension, an adverse serum lipid profile, fatty liver, glucose intolerance, insulin resistance, and evidence of an inflammatory state. PMID:22185842

  11. Gene-dosage effects in Down syndrome and trisomic mouse models.

    PubMed

    Gardiner, Katheleen

    2004-01-01

    The abnormalities found in human Down syndrome (trisomy 21) have been thought to result from increased expression of genes on chromosome 21 because of their higher gene dosage. Now, several groups have shown this to be generally the case, but some inter-individual variability and other exceptions were found. PMID:15461808

  12. Characterization and Demonstration of the Value of a Lethal Mouse Model of Middle East Respiratory Syndrome Coronavirus Infection and Disease

    PubMed Central

    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.

    2015-01-01

    ABSTRACT 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 105 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. IMPORTANCE 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

  13. Genetic Background Modulates Impaired Excitability of Inhibitory Neurons in a Mouse Model of Dravet Syndrome

    PubMed Central

    Rubinstein, Moran; Westenbroek, Ruth E.; Yu, Frank H.; Jones, Christina J.; Scheuer, Todd; Catterall, William A.

    2014-01-01

    Dominant loss-of-function mutations in voltage-gated sodium channel NaV1.1 cause Dravet Syndrome, an intractable childhood-onset epilepsy. NaV1.1+/− Dravet Syndrome mice in C57BL/6 genetic background exhibit severe seizures, cognitive and social impairments, and premature death. Here we show that Dravet Syndrome mice in pure 129/SvJ genetic background have many fewer seizures and much less premature death than in pure C57BL/6 background. These mice also have a higher threshold for thermally induced seizures, fewer myoclonic seizures, and no cognitive impairment, similar to patients with Genetic Epilepsy with Febrile Seizures Plus. Consistent with this mild phenotype, mutation of NaV1.1 channels has much less physiological effect on neuronal excitability in 129/SvJ mice. In hippocampal slices, the excitability of CA1 Stratum Oriens interneurons is selectively impaired, while the excitability of CA1 pyramidal cells is unaffected. NaV1.1 haploinsufficiency results in increased rheobase and threshold for action potential firing and impaired ability to sustain high-frequency firing. Moreover, deletion of NaV1.1 markedly reduces the amplification and integration of synaptic events, further contributing to reduced excitability of interneurons. Excitability is less impaired in inhibitory neurons of Dravet Syndrome mice in 129/SvJ genetic background. Because specific deletion of NaV1.1 in forebrain GABAergic interneuons is sufficient to cause the symptoms of Dravet Syndrome in mice, our results support the conclusion that the milder phenotype in 129/SvJ mice is caused by lesser impairment of sodium channel function and electrical excitability in their forebrain interneurons. This mild impairment of excitability of interneurons leads to a milder disease phenotype in 129/SvJ mice, similar to Genetic Epilepsy with Febrile Seizures Plus in humans. PMID:25281316

  14. Seizure-like activity in a juvenile Angelman syndrome mouse model is attenuated by reducing Arc expression.

    PubMed

    Mandel-Brehm, Caleigh; Salogiannis, John; Dhamne, Sameer C; Rotenberg, Alexander; Greenberg, Michael E

    2015-04-21

    Angelman syndrome (AS) is a neurodevelopmental disorder arising from loss-of-function mutations in the maternally inherited copy of the UBE3A gene, and is characterized by an absence of speech, excessive laughter, cognitive delay, motor deficits, and seizures. Despite the fact that the symptoms of AS occur in early childhood, behavioral characterization of AS mouse models has focused primarily on adult phenotypes. In this report we describe juvenile behaviors in AS mice that are strain-independent and clinically relevant. We find that young AS mice, compared with their wild-type littermates, produce an increased number of ultrasonic vocalizations. In addition, young AS mice have defects in motor coordination, as well as abnormal brain activity that results in an enhanced seizure-like response to an audiogenic challenge. The enhanced seizure-like activity, but not the increased ultrasonic vocalizations or motor deficits, is rescued in juvenile AS mice by genetically reducing the expression level of the activity-regulated cytoskeleton-associated protein, Arc. These findings suggest that therapeutic interventions that reduce the level of Arc expression have the potential to reverse the seizures associated with AS. In addition, the identification of aberrant behaviors in young AS mice may provide clues regarding the neural circuit defects that occur in AS and ultimately allow new approaches for treating this disorder. PMID:25848016

  15. Increased Cortical Synaptic Activation of TrkB and Downstream Signaling Markers in a Mouse Model of Down Syndrome

    PubMed Central

    Nosheny, RL; Belichenko, PV; Busse, BL; Weissmiller, AM; Dang, V; Das, D; Fahimi, A; Salehi, A; Smith, SJ; Mobley, WC

    2015-01-01

    Down Syndrome (DS), trisomy 21, is characterized by synaptic abnormalities and cognitive deficits throughout the lifespan and with development of Alzheimer’s disease (AD) neuropathology and progressive cognitive decline in adults. Synaptic abnormalities are also present in the Ts65Dn mouse model of DS, but which synapses are affected and the mechanisms underlying synaptic dysfunction are unknown. Here we show marked increases in the levels and activation status of TrkB and associated signaling proteins in cortical synapses in Ts65Dn mice. Proteomic analysis at the single synapse level of resolution using array tomography (AT) uncovered increased colocalization of activated TrkB with signaling endosome related proteins, and demonstrated increased TrkB signaling. The extent of increases in TrkB signaling differed in each of the cortical layers examined and with respect to the type of synapse, with the most marked increases seen in inhibitory synapses. These findings are evidence of markedly abnormal TrkB-mediated signaling in synapses. They raise the possibility that dysregulated TrkB signaling contributes to synaptic dysfunction and cognitive deficits in DS. PMID:25753471

  16. PEX13 deficiency in mouse brain as a model of Zellweger syndrome: abnormal cerebellum formation, reactive gliosis and oxidative stress

    PubMed Central

    Müller, C. Catharina; Nguyen, Tam H.; Ahlemeyer, Barbara; Meshram, Mallika; Santrampurwala, Nishreen; Cao, Siyu; Sharp, Peter; Fietz, Pamela B.; Baumgart-Vogt, Eveline; Crane, Denis I.

    2011-01-01

    SUMMARY Delayed cerebellar development is a hallmark of Zellweger syndrome (ZS), a severe neonatal neurodegenerative disorder. ZS is caused by mutations in PEX genes, such as PEX13, which encodes a protein required for import of proteins into the peroxisome. The molecular basis of ZS pathogenesis is not known. We have created a conditional mouse mutant with brain-restricted deficiency of PEX13 that exhibits cerebellar morphological defects. PEX13 brain mutants survive into the postnatal period, with the majority dying by 35 days, and with survival inversely related to litter size and weaning body weight. The impact on peroxisomal metabolism in the mutant brain is mixed: plasmalogen content is reduced, but very-long-chain fatty acids are normal. PEX13 brain mutants exhibit defects in reflex and motor development that correlate with impaired cerebellar fissure and cortical layer formation, granule cell migration and Purkinje cell layer development. Astrogliosis and microgliosis are prominent features of the mutant cerebellum. At the molecular level, cultured cerebellar neurons from E19 PEX13-null mice exhibit elevated levels of reactive oxygen species and mitochondrial superoxide dismutase-2 (MnSOD), and show enhanced apoptosis together with mitochondrial dysfunction. PEX13 brain mutants show increased levels of MnSOD in cerebellum. Our findings suggest that PEX13 deficiency leads to mitochondria-mediated oxidative stress, neuronal cell death and impairment of cerebellar development. Thus, PEX13-deficient mice provide a valuable animal model for investigating the molecular basis and treatment of ZS cerebellar pathology. PMID:20959636

  17. Sonic hedgehog signalling inhibits palatogenesis and arrests tooth development in a mouse model of the nevoid basal cell carcinoma syndrome.

    PubMed

    Cobourne, Martyn T; Xavier, Guilherme M; Depew, Michael; Hagan, Louise; Sealby, Jane; Webster, Zoe; Sharpe, Paul T

    2009-07-01

    Nevoid basal cell carcinoma syndrome (NBCCS) is an autosomal dominant or spontaneous disorder characterized by multiple cutaneous basal cell carcinomas, odontogenic keratocysts, skeletal anomalies and facial dysmorphology, including cleft lip and palate. Causative mutations for NBCCS occur in the PTCH1 gene on chromosome 9q22.3-q31, which encodes the principle receptor for the Hedgehog signalling pathway. We have investigated the molecular basis of craniofacial defects seen in NBCCS using a transgenic mouse model expressing Shh in basal epithelium under a Keratin-14 promoter. These mice have an absence of flat bones within the skull vault, hypertelorism, open-bite malocclusion, cleft palate and arrested tooth development. Significantly, increased Hedgehog signal transduction in these mice can influence cell fate within the craniofacial region. In medial edge epithelium of the palate, Shh activity prevents apoptosis and subsequent palatal shelf fusion. In contrast, high levels of Shh in odontogenic epithelium arrests tooth development at the bud stage, secondary to a lack of cell proliferation in this region. These findings illustrate the importance of appropriately regulated Hedgehog signalling during early craniofacial development and demonstrate that oro-facial clefting and hypodontia seen in NBCCS can occur as a direct consequence of increased Shh signal activity within embryonic epithelial tissues. PMID:19394325

  18. Etiology of craniofacial malformations in mouse models of blepharophimosis, ptosis and epicanthus inversus syndrome.

    PubMed

    Heude, Églantine; Bellessort, Brice; Fontaine, Anastasia; Hamazaki, Manatsu; Treier, Anna-Corina; Treier, Mathias; Levi, Giovanni; Narboux-Nême, Nicolas

    2015-03-15

    Blepharophimosis, ptosis, epicanthus-inversus syndrome (BPES) is an autosomal dominant genetic disorder characterized by narrow palpebral fissures and eyelid levator muscle defects. BPES is often associated to premature ovarian insufficiency (BPES type I). FOXL2, a member of the forkhead transcription factor family, is the only gene known to be mutated in BPES. Foxl2 is essential for maintenance of ovarian identity, but the developmental origin of the facial malformations of BPES remains, so far, unexplained. In this study, we provide the first detailed account of the developmental processes leading to the craniofacial malformations associated to Foxl2. We show that, during development, Foxl2 is expressed both by Cranial Neural Crest Cells (CNCCs) and by Cranial Mesodermal Cells (CMCs), which give rise to skeletal (CNCCs and CMCs) and muscular (CMCs) components of the head. Using mice in which Foxl2 is selectively inactivated in either CNCCs or CMCs, we reveal that expression of Foxl2 in CNCCs is essential for the development of extraocular muscles. Indeed, inactivation of Foxl2 in CMCs has only minor effects on muscle development, whereas its inactivation in CNCCs provokes a severe hypoplasia of the levator palpabrae superioris and of the superior and inferior oblique muscles. We further show that Foxl2 deletion in either CNCCs or CMCs prevents eyelid closure and induces subtle skeletal developmental defects. Our results provide new insights in the complex developmental origin of human BPES and could help to understand the origin of other ocular anomalies associated to this syndrome. PMID:25416281

  19. Reciprocal Effects on Neurocognitive and Metabolic Phenotypes in Mouse Models of 16p11.2 Deletion and Duplication Syndromes

    PubMed Central

    Arbogast, Thomas; Ouagazzal, Abdel-Mouttalib; Chevalier, Claire; Kopanitsa, Maksym; Afinowi, Nurudeen; Migliavacca, Eugenia; Cowling, Belinda S.; Birling, Marie-Christine; Champy, Marie-France; Reymond, Alexandre; Herault, Yann

    2016-01-01

    The 16p11.2 600 kb BP4-BP5 deletion and duplication syndromes have been associated with developmental delay; autism spectrum disorders; and reciprocal effects on the body mass index, head circumference and brain volumes. Here, we explored these relationships using novel engineered mouse models carrying a deletion (Del/+) or a duplication (Dup/+) of the Sult1a1-Spn region homologous to the human 16p11.2 BP4-BP5 locus. On a C57BL/6N inbred genetic background, Del/+ mice exhibited reduced weight and impaired adipogenesis, hyperactivity, repetitive behaviors, and recognition memory deficits. In contrast, Dup/+ mice showed largely opposite phenotypes. On a F1 C57BL/6N × C3B hybrid genetic background, we also observed alterations in social interaction in the Del/+ and the Dup/+ animals, with other robust phenotypes affecting recognition memory and weight. To explore the dosage effect of the 16p11.2 genes on metabolism, Del/+ and Dup/+ models were challenged with high fat and high sugar diet, which revealed opposite energy imbalance. Transcriptomic analysis revealed that the majority of the genes located in the Sult1a1-Spn region were sensitive to dosage with a major effect on several pathways associated with neurocognitive and metabolic phenotypes. Whereas the behavioral consequence of the 16p11 region genetic dosage was similar in mice and humans with activity and memory alterations, the metabolic defects were opposite: adult Del/+ mice are lean in comparison to the human obese phenotype and the Dup/+ mice are overweight in comparison to the human underweight phenotype. Together, these data indicate that the dosage imbalance at the 16p11.2 locus perturbs the expression of modifiers outside the CNV that can modulate the penetrance, expressivity and direction of effects in both humans and mice. PMID:26872257

  20. An Anti-β-Amyloid Vaccine for Treating Cognitive Deficits in a Mouse Model of Down Syndrome

    PubMed Central

    Rey-Bellet, Lorianne; Pihlgren, Maria; Becker, Ann; Plassard, Adeline; Vuillermot, Stephanie; Giriens, Valérie; Nosheny, Rachel L.; Kleschevnikov, Alexander M.; Valletta, Janice S.; Bengtsson, Sara K. S.; Linke, Gordon R.; Maloney, Michael T.; Hickman, David T.; Reis, Pedro; Granet, Anne; Mlaki, Dorin; Lopez-Deber, Maria Pilar; Do, Long; Singhal, Nishant; Masliah, Eliezer; Pearn, Matthew L.; Pfeifer, Andrea; Muhs, Andreas; Mobley, William C.

    2016-01-01

    In Down syndrome (DS) or trisomy of chromosome 21, the β-amyloid (Aβ) peptide product of the amyloid precursor protein (APP) is present in excess. Evidence points to increased APP gene dose and Aβ as playing a critical role in cognitive difficulties experienced by people with DS. Particularly, Aβ is linked to the late-life emergence of dementia as associated with neuropathological markers of Alzheimer’s disease (AD). At present, no treatment targets Aβ–related pathogenesis in people with DS. Herein we used a vaccine containing the Aβ 1–15 peptide embedded into liposomes together with the adjuvant monophosphoryl lipid A (MPLA). Ts65Dn mice, a model of DS, were immunized with the anti-Aβ vaccine at 5 months of age and were examined for cognitive measures at 8 months of age. The status of basal forebrain cholinergic neurons and brain levels of APP and its proteolytic products were measured. Immunization of Ts65Dn mice resulted in robust anti-Aβ IgG titers, demonstrating the ability of the vaccine to break self-tolerance. The vaccine-induced antibodies reacted with Aβ without detectable binding to either APP or its C-terminal fragments. Vaccination of Ts65Dn mice resulted in a modest, but non-significant reduction in brain Aβ levels relative to vehicle-treated Ts65Dn mice, resulting in similar levels of Aβ as diploid (2N) mice. Importantly, vaccinated Ts65Dn mice showed resolution of memory deficits in the novel object recognition and contextual fear conditioning tests, as well as reduction of cholinergic neuron atrophy. No treatment adverse effects were observed; vaccine did not result in inflammation, cellular infiltration, or hemorrhage. These data are the first to show that an anti-Aβ immunotherapeutic approach may act to target Aβ-related pathology in a mouse model of DS. PMID:27023444

  1. Reciprocal Effects on Neurocognitive and Metabolic Phenotypes in Mouse Models of 16p11.2 Deletion and Duplication Syndromes.

    PubMed

    Arbogast, Thomas; Ouagazzal, Abdel-Mouttalib; Chevalier, Claire; Kopanitsa, Maksym; Afinowi, Nurudeen; Migliavacca, Eugenia; Cowling, Belinda S; Birling, Marie-Christine; Champy, Marie-France; Reymond, Alexandre; Herault, Yann

    2016-02-01

    The 16p11.2 600 kb BP4-BP5 deletion and duplication syndromes have been associated with developmental delay; autism spectrum disorders; and reciprocal effects on the body mass index, head circumference and brain volumes. Here, we explored these relationships using novel engineered mouse models carrying a deletion (Del/+) or a duplication (Dup/+) of the Sult1a1-Spn region homologous to the human 16p11.2 BP4-BP5 locus. On a C57BL/6N inbred genetic background, Del/+ mice exhibited reduced weight and impaired adipogenesis, hyperactivity, repetitive behaviors, and recognition memory deficits. In contrast, Dup/+ mice showed largely opposite phenotypes. On a F1 C57BL/6N × C3B hybrid genetic background, we also observed alterations in social interaction in the Del/+ and the Dup/+ animals, with other robust phenotypes affecting recognition memory and weight. To explore the dosage effect of the 16p11.2 genes on metabolism, Del/+ and Dup/+ models were challenged with high fat and high sugar diet, which revealed opposite energy imbalance. Transcriptomic analysis revealed that the majority of the genes located in the Sult1a1-Spn region were sensitive to dosage with a major effect on several pathways associated with neurocognitive and metabolic phenotypes. Whereas the behavioral consequence of the 16p11 region genetic dosage was similar in mice and humans with activity and memory alterations, the metabolic defects were opposite: adult Del/+ mice are lean in comparison to the human obese phenotype and the Dup/+ mice are overweight in comparison to the human underweight phenotype. Together, these data indicate that the dosage imbalance at the 16p11.2 locus perturbs the expression of modifiers outside the CNV that can modulate the penetrance, expressivity and direction of effects in both humans and mice. PMID:26872257

  2. Affective dysfunction in a mouse model of Rett syndrome: Therapeutic effects of environmental stimulation and physical activity.

    PubMed

    Kondo, Mari A; Gray, Laura J; Pelka, Gregory J; Leang, Sook-Kwan; Christodoulou, John; Tam, Patrick P L; Hannan, Anthony J

    2016-02-01

    Rett syndrome (RTT) is a neurodevelopmental disorder associated with mutations in the X-linked gene encoding methyl-CpG-binding protein 2 (MeCP2) and consequent dysregulation of brain maturation. Patients suffer from a range of debilitating physical symptoms, however, behavioral and emotional symptoms also severely affect their quality of life. Here, we present previously unreported and clinically relevant affective dysfunction in the female heterozygous Mecp2(tm1Tam) mouse model of RTT (129sv and C57BL6 mixed background). The affective dysfunction and aberrant anxiety-related behavior of the Mecp2(+/-) mice were found to be reversible with environmental enrichment (EE) from 4 weeks of age. The effect of exercise alone (via wheel running) was also explored, providing the first evidence that increased voluntary physical activity in an animal model of RTT is beneficial for some phenotypes. Mecp2(+/-) mutants displayed elevated corticosterone despite decreased Crh expression, demonstrating hypothalamic-pituitary-adrenal axis dysregulation. EE of Mecp2(+/-) mice normalized basal serum corticosterone and hippocampal BDNF protein levels. The enrichment-induced rescue appears independent of the transcriptional regulation of the MeCP2 targets Bdnf exon 4 and Crh. These findings provide new insight into the neurodevelopmental role of MeCP2 and pathogenesis of RTT, in particular the affective dysfunction. The positive outcomes of environmental stimulation and physical exercise have implications for the development of therapies targeting the affective symptoms, as well as behavioral and cognitive dimensions, of this devastating neurodevelopmental disorder. PMID:26019053

  3. Ultrasonic vocalizations during male-female interaction in the mouse model of Down syndrome Ts65Dn.

    PubMed

    Zampieri, Bruna L; Fernandez, Fabian; Pearson, Jennifer N; Stasko, Melissa R; Costa, Alberto C S

    2014-04-10

    Down syndrome (DS) is the leading cause of genetically defined intellectual disability. Although speech and language impairments are salient features of this disorder, the nature of these phenotypes and the degree to which they are exacerbated by concomitant oromotor dysfunction and/or hearing deficit are poorly understood. Mouse models like Ts65Dn, the most extensively used DS animal model, have been critical to understanding the genetic and developmental mechanisms that contribute to intellectual disability. In the present study, we characterized the properties of the ultrasonic vocalizations (USVs) emitted by Ts65Dn males during courtship episodes with female partners. USVs emitted by mice in this setting have been proposed to have some basic correlation to human speech. Data were collected and analyzed from 22 Ts65Dn mice and 22 of their euploid littermates. We found that both the minimum and maximum peak frequencies of Ts65Dn calls were lower than those produced by euploid mice, whereas the mean individual duration of "down" and "complex" syllable types was significantly longer. Peak, minimal and maximal, and the fundamental frequencies of short syllables generated by Ts65Dn mice were lower compared to those by euploid mice. Finally, Ts65Dn males made fewer multiple jumps calls during courtship and the mean total duration of their "arc", "u", and "complex" syllables was longer. We discuss the human correlates to these findings, their translational potential, and the limitations of this approach. To our knowledge, this is the first characterization of differences between adult Ts65Dn and euploid control mice with respect to USVs. PMID:24534182

  4. Prevention of Treacher Collins syndrome craniofacial anomalies in mouse models via maternal antioxidant supplementation

    PubMed Central

    Sakai, Daisuke; Dixon, Jill; Achilleos, Annita; Dixon, Michael; Trainor, Paul A.

    2016-01-01

    Craniofacial anomalies account for approximately one-third of all birth defects and are a significant cause of infant mortality. Since the majority of the bones, cartilage and connective tissues that comprise the head and face are derived from a multipotent migratory progenitor cell population called the neural crest, craniofacial disorders are typically attributed to defects in neural crest cell development. Treacher Collins syndrome (TCS) is a disorder of craniofacial development and although TCS arises primarily through autosomal dominant mutations in TCOF1, no clear genotype–phenotype correlation has been documented. Here we show that Tcof1 haploinsufficiency results in oxidative stress-induced DNA damage and neuroepithelial cell death. Consistent with this discovery, maternal treatment with antioxidants minimizes cell death in the neuroepithelium and substantially ameliorates or prevents the pathogenesis of craniofacial anomalies in Tcof1+/− mice. Thus maternal antioxidant dietary supplementation may provide an avenue for protection against the pathogenesis of TCS and similar neurocristopathies. PMID:26792133

  5. Prevention of Treacher Collins syndrome craniofacial anomalies in mouse models via maternal antioxidant supplementation.

    PubMed

    Sakai, Daisuke; Dixon, Jill; Achilleos, Annita; Dixon, Michael; Trainor, Paul A

    2016-01-01

    Craniofacial anomalies account for approximately one-third of all birth defects and are a significant cause of infant mortality. Since the majority of the bones, cartilage and connective tissues that comprise the head and face are derived from a multipotent migratory progenitor cell population called the neural crest, craniofacial disorders are typically attributed to defects in neural crest cell development. Treacher Collins syndrome (TCS) is a disorder of craniofacial development and although TCS arises primarily through autosomal dominant mutations in TCOF1, no clear genotype-phenotype correlation has been documented. Here we show that Tcof1 haploinsufficiency results in oxidative stress-induced DNA damage and neuroepithelial cell death. Consistent with this discovery, maternal treatment with antioxidants minimizes cell death in the neuroepithelium and substantially ameliorates or prevents the pathogenesis of craniofacial anomalies in Tcof1(+/-) mice. Thus maternal antioxidant dietary supplementation may provide an avenue for protection against the pathogenesis of TCS and similar neurocristopathies. PMID:26792133

  6. Pharmacological Rescue of Cortical Synaptic and Network Potentiation in a Mouse Model for Fragile X Syndrome

    PubMed Central

    Chen, Tao; Lu, Jing-Shan; Song, Qian; Liu, Ming-Gang; Koga, Kohei; Descalzi, Giannina; Li, Yun-Qing; Zhuo, Min

    2014-01-01

    Fragile X syndrome, caused by the mutation of the Fmr1 gene, is characterized by deficits of attention and learning ability. In the hippocampus of Fmr1 knockout mice (KO), long-term depression is enhanced whereas long-term potentiation (LTP) including late-phase LTP (L-LTP) is reduced or unaffected. Here we examined L-LTP in the anterior cingulate cortex (ACC) in Fmr1 KO mice by using a 64-electrode array recording system. In wild-type mice, theta-burst stimulation induced L-LTP that does not occur in all active electrodes/channels within the cingulate circuit and is typically detected in ∼75% of active channels. Furthermore, L-LTP recruited new responses from previous inactive channels. Both L-LTP and the recruitment of inactive responses were blocked in the ACC slices of Fmr1 KO mice. Bath application of metabotropic glutamate receptor 5 (mGluR5) antagonist or glycogen synthase kinase-3 (GSK3) inhibitors rescued the L-LTP and network recruitment. Our results demonstrate that loss of FMRP will greatly impair L-LTP and recruitment of cortical network in the ACC that can be rescued by pharmacological inhibition of mGluR5 or GSK3. This study is the first report of the network properties of L-LTP in the ACC, and provides basic mechanisms for future treatment of cortex-related cognitive defects in fragile X patients. PMID:24553731

  7. 7,8-dihydroxyflavone exhibits therapeutic efficacy in a mouse model of Rett syndrome

    PubMed Central

    Johnson, Rebecca A.; Lam, Maxine; Punzo, Antonio M.; Li, Hongda; Lin, Benjamin R.; Ye, Keqiang; Mitchell, Gordon S.

    2012-01-01

    Rett syndrome (RTT), caused by mutations in the methyl-CpG binding protein 2 gene (MECP2), is a debilitating autism spectrum developmental disorder predominantly affecting females. Mecp2 mutant mice have reduced levels of brain-derived neurotrophic factor (BDNF) in the brain; conditional deletion and overexpression of BDNF in the brain accelerates and slows, respectively, disease progression in Mecp2 mutant mice. Thus we tested the hypothesis that 7,8-dihydroxyflavone (7,8-DHF), a small molecule reported to activate the high affinity BDNF receptor (TrkB) in the CNS, would attenuate disease progression in Mecp2 mutant mice. Following weaning, 7,8-DHF was administered in drinking water throughout life. Treated mutant mice lived significantly longer compared with untreated mutant littermates (80 ± 4 and 66 ± 2 days, respectively). 7,8-DHF delayed body weight loss, increased neuronal nuclei size and enhanced voluntary locomotor (running wheel) distance in Mecp2 mutant mice. In addition, administration of 7,8-DHF partially improved breathing pattern irregularities and returned tidal volumes to near wild-type levels. Thus although the specific mechanisms are not completely known, 7,8-DHF appears to reduce disease symptoms in Mecp2 mutant mice and may have potential as a therapeutic treatment for RTT patients. PMID:22194327

  8. Up-regulation of glucocorticoid-regulated genes in a mouse model of Rett syndrome.

    PubMed

    Nuber, Ulrike A; Kriaucionis, Skirmantas; Roloff, Tim C; Guy, Jacky; Selfridge, Jim; Steinhoff, Christine; Schulz, Ralph; Lipkowitz, Bettina; Ropers, H Hilger; Holmes, Megan C; Bird, Adrian

    2005-08-01

    Rett syndrome (RTT) is a severe form of mental retardation, which is caused by spontaneous mutations in the X-linked gene MECP2. How the loss of MeCP2 function leads to RTT is currently unknown. Mice lacking the Mecp2 gene initially show normal postnatal development but later acquire neurological phenotypes, including heightened anxiety, that resemble RTT. The MECP2 gene encodes a methyl-CpG-binding protein that can act as a transcriptional repressor. Using cDNA microarrays, we found that Mecp2-null animals differentially express several genes that are induced during the stress response by glucocorticoids. Increased levels of mRNAs for serum glucocorticoid-inducible kinase 1 (Sgk) and FK506-binding protein 51 (Fkbp5) were observed before and after onset of neurological symptoms, but plasma glucocorticoid was not significantly elevated in Mecp2-null mice. MeCP2 is bound to the Fkbp5 and Sgk genes in brain and may function as a modulator of glucocorticoid-inducible gene expression. Given the known deleterious effect of glucocorticoid exposure on brain development, our data raise the possibility that disruption of MeCP2-dependent regulation of stress-responsive genes contributes to the symptoms of RTT. PMID:16002417

  9. 7-dehydrocholesterol efficiently supports Ret signaling in a mouse model of Smith-Opitz-Lemli syndrome

    PubMed Central

    Gou-Fàbregas, Myriam; Macià, Anna; Anerillas, Carlos; Vaquero, Marta; Jové, Mariona; Jain, Sanjay; Ribera, Joan; Encinas, Mario

    2016-01-01

    Smith-Lemli-Opitz syndrome (SLOS) is a rare disorder of cholesterol synthesis. Affected individuals exhibit growth failure, intellectual disability and a broad spectrum of developmental malformations. Among them, renal agenesis or hypoplasia, decreased innervation of the gut, and ptosis are consistent with impaired Ret signaling. Ret is a receptor tyrosine kinase that achieves full activity when recruited to lipid rafts. Mice mutant for Ret are born with no kidneys and enteric neurons, and display sympathetic nervous system defects causing ptosis. Since cholesterol is a critical component of lipid rafts, here we tested the hypothesis of whether the cause of the above malformations found in SLOS is defective Ret signaling owing to improper lipid raft composition or function. No defects consistent with decreased Ret signaling were found in newborn Dhcr7−/− mice, or in Dhcr7−/− mice lacking one copy of Ret. Although kidneys from Dhcr7−/− mice showed a mild branching defect in vitro, GDNF was able to support survival and downstream signaling of sympathetic neurons. Consistently, GFRα1 correctly partitioned to lipid rafts in brain tissue. Finally, replacement experiments demonstrated that 7-DHC efficiently supports Ret signaling in vitro. Taken together, our findings do not support a role of Ret signaling in the pathogenesis of SLOS. PMID:27334845

  10. Apoptosis in Down's syndrome: lessons from studies of human and mouse models.

    PubMed

    Rueda, Noemí; Flórez, Jesús; Martínez-Cué, Carmen

    2013-02-01

    Down syndrome (DS) is the most common chromosomal abnormality in humans. DS is characterized by a number of phenotypes, including the development of Alzheimer's disease-like pathology and immunological, hematological and cardiovascular alterations. Apoptosis or programmed cell death is physiologically involved in development and aging, as well as in numerous pathological processes. Altered apoptosis has been proposed as a putative mechanism underlying many DS phenotypes. Evidence from human and animal studies indicates that apoptosis does not have a prominent role in the disturbances found in brain development in trisomy 21. However, alterations in apoptosis have been associated with neurodegeneration in the aging DS brain, with impairments in general growth and with immunological, cardiovascular and oncological alterations. Altered apoptosis in DS is likely to be the result of the interplay between several chromosome 21 (Hsa21) and non-Hsa21 genes. The interplay between these genes may affect physiological programmed cell death either directly, by modifying the activity of the apoptotic pathways, or indirectly, by inducing degeneration and rendering the cell more vulnerable to apoptosis-inducing factors. PMID:23224708

  11. R-Baclofen Reverses a Social Behavior Deficit and Elevated Protein Synthesis in a Mouse Model of Fragile X Syndrome

    PubMed Central

    Qin, Mei; Huang, Tianjian; Kader, Michael; Krych, Leland; Xia, Zengyan; Burlin, Thomas; Zeidler, Zachary; Zhao, Tingrui

    2015-01-01

    Background: Fragile X syndrome (FXS) is the most common known inherited form of intellectual disability and the single genomic cause of autism spectrum disorders. It is caused by the absence of a fragile X mental retardation gene (Fmr1) product, FMRP, an RNA-binding translation suppressor. Elevated rates of protein synthesis in the brain and an imbalance between synaptic signaling via glutamate and γ-aminobutyric acid (GABA) are both considered important in the pathogenesis of FXS. In a mouse model of FXS (Fmr1 knockout [KO]), treatment with R-baclofen reversed some behavioral and biochemical phenotypes. A remaining crucial question is whether R-baclofen is also able to reverse increased brain protein synthesis rates. Methods: To answer this question, we measured regional rates of cerebral protein synthesis in vivo with the L-[1-14C]leucine method in vehicle- and R-baclofen–treated wildtype and Fmr1 KO mice. We further probed signaling pathways involved in the regulation of protein synthesis. Results: Acute R-baclofen administration corrected elevated protein synthesis and reduced deficits on a test of social behavior in adult Fmr1 KO mice. It also suppressed activity of the mammalian target of rapamycin pathway, particularly in synaptosome-enriched fractions, but it had no effect on extracellular-regulated kinase 1/2 activity. Ninety min after R-baclofen treatment, we observed an increase in metabotropic glutamate receptor 5 expression in the frontal cortex, a finding that may shed light on the tolerance observed in human studies with this drug. Conclusions: Our results suggest that treatment via activation of the GABA (GABA receptor subtype B) system warrants further study in patients with FXS. PMID:25820841

  12. Ampakines promote spine actin polymerization, long-term potentiation, and learning in a mouse model of Angelman Syndrome

    PubMed Central

    Baudry, Michel; Kramar, Eniko; Xu, Xiaobo; Zadran, Homera; Moreno, Stephanie; Lynch, Gary; Gall, Christine; Bi, Xiaoning

    2012-01-01

    Angelman syndrome (AS) is a neurodevelopmental disorder largely due to abnormal maternal expression of the UBE3A gene leading to the deletion of E6-associated protein. AS subjects have severe cognitive impairments for which there are no therapeutic interventions. Mouse models (knockouts of the maternal Ube3a gene: ‘AS mice’) of the disorder have substantial deficits in long-term potentiation (LTP) and learning. Here we report a clinically plausible pharmacological treatment that ameliorates both deficits. AS mice were injected ip twice daily for 5 days with vehicle or the ampakine CX929; drugs of this type enhance fast EPSCs by positively modulating AMPA receptors. Theta burst stimulation (TBS) produced a normal enhancement of field EPSPs in hippocampal slices prepared from vehicle-treated AS mice but LTP decreased steadily to baseline; however, LTP in slices from ampakine-treated AS mice stabilized at levels found in wild-type controls. TBS-induced actin polymerization within dendritic spines, an essential event for stabilizing LTP, was severely impaired in slices from vehicle-treated AS mice but not in those from ampakine-treated AS mice. Long-term memory scores in a fear conditioning paradigm were reduced by 50% in vehicle-treated AS mice but were comparable to values for littermate controls in the ampakine-treated AS mice. We propose that AS is associated with a profound defect in activity-driven spine cytoskeletal reorganization, resulting in a loss of the synaptic plasticity required for the encoding of long-term memory. Notably, the spine abnormality along with the LTP and learning impairments can be reduced by a minimally invasive drug treatment. PMID:22525571

  13. Early Social Enrichment Rescues Adult Behavioral and Brain Abnormalities in a Mouse Model of Fragile X Syndrome

    PubMed Central

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

    2015-01-01

    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. PMID:25348604

  14. Dysphagia and disrupted cranial nerve development in a mouse model of DiGeorge (22q11) deletion syndrome

    PubMed Central

    Karpinski, Beverly A.; Maynard, Thomas M.; Fralish, Matthew S.; Nuwayhid, Samer; Zohn, Irene E.; Moody, Sally A.; LaMantia, Anthony-S.

    2014-01-01

    ABSTRACT We assessed feeding-related developmental anomalies in the LgDel mouse model of chromosome 22q11 deletion syndrome (22q11DS), a common developmental disorder that frequently includes perinatal dysphagia – debilitating feeding, swallowing and nutrition difficulties from birth onward – within its phenotypic spectrum. LgDel pups gain significantly less weight during the first postnatal weeks, and have several signs of respiratory infections due to food aspiration. Most 22q11 genes are expressed in anlagen of craniofacial and brainstem regions critical for feeding and swallowing, and diminished expression in LgDel embryos apparently compromises development of these regions. Palate and jaw anomalies indicate divergent oro-facial morphogenesis. Altered expression and patterning of hindbrain transcriptional regulators, especially those related to retinoic acid (RA) signaling, prefigures these disruptions. Subsequently, gene expression, axon growth and sensory ganglion formation in the trigeminal (V), glossopharyngeal (IX) or vagus (X) cranial nerves (CNs) that innervate targets essential for feeding, swallowing and digestion are disrupted. Posterior CN IX and X ganglia anomalies primarily reflect diminished dosage of the 22q11DS candidate gene Tbx1. Genetic modification of RA signaling in LgDel embryos rescues the anterior CN V phenotype and returns expression levels or pattern of RA-sensitive genes to those in wild-type embryos. Thus, diminished 22q11 gene dosage, including but not limited to Tbx1, disrupts oro-facial and CN development by modifying RA-modulated anterior-posterior hindbrain differentiation. These disruptions likely contribute to dysphagia in infants and young children with 22q11DS. PMID:24357327

  15. Pathophysiology of Locus Ceruleus Neurons in a Mouse Model of Rett Syndrome

    PubMed Central

    Taneja, Praveen; Ogier, Michael; Brooks-Harris, Gabriel; Schmid, Danielle A.; Katz, David M.; Nelson, Sacha B.

    2010-01-01

    Rett syndrome (RTT) is a neurodevelopmental disorder caused by loss-of-function mutations in the Methyl-CpG-binding protein-2 (MECP2) gene and is characterized by derangements in cognition, behavior, motor control, respiration and autonomic homeostasis, as well as seizures. Deficits in norepinephrine (NE) are thought to contribute to RTT pathogenesis, but little is known about how MeCP2 regulates function of noradrenergic neurons. We therefore characterized morphological, electrical, and neurochemical properties of neurons in the locus ceruleus (LC), the major source of noradrenergic innervation to the central neuraxis, in Mecp2 mutant mice. We found that MeCP2 null LC neurons are electrically hyperexcitable, smaller in size, and express less of the NE-synthesizing enzyme tyrosine hydroxylase (TH) compared with wild-type neurons. Increased excitability of mutant neurons is associated with reductions in passive membrane conductance and the amplitude of the slow afterhyperpolarization. Studies in Mecp2 heterozygotes, which are mosaic for the null allele, demonstrated that electrical hyperexcitability and reduced neuronal size are cell-autonomous consequences of MeCP2 loss, whereas reduced TH expression appears to reflect both cell-autonomous and non-autonomous influences. Finally, we found reduced levels of TH and norepinephrine in cingulate cortex, a forebrain target of the LC. Thus, genetic loss of MeCP2 results in a somewhat paradoxical LC neuron phenotype, characterized by both electrical hyperexcitability and reduced indices of noradrenergic function. Given the importance of the LC in modulating activity in brainstem and forebrain networks, we hypothesize that dysregulation of LC function in the absence of MeCP2 plays a key role in the pathophysiology of RTT. PMID:19793977

  16. Cardiac Metabolic Pathways Affected in the Mouse Model of Barth Syndrome

    PubMed Central

    Huang, Yan; Powers, Corey; Madala, Satish K.; Greis, Kenneth D.; Haffey, Wendy D.; Towbin, Jeffrey A.; Purevjav, Enkhsaikhan; Javadov, Sabzali; Strauss, Arnold W.; Khuchua, Zaza

    2015-01-01

    Cardiolipin (CL) is a mitochondrial phospholipid essential for electron transport chain (ETC) integrity. CL-deficiency in humans is caused by mutations in the tafazzin (Taz) gene and results in a multisystem pediatric disorder, Barth syndrome (BTHS). It has been reported that tafazzin deficiency destabilizes mitochondrial respiratory chain complexes and affects supercomplex assembly. The aim of this study was to investigate the impact of Taz-knockdown on the mitochondrial proteomic landscape and metabolic processes, such as stability of respiratory chain supercomplexes and their interactions with fatty acid oxidation enzymes in cardiac muscle. Proteomic analysis demonstrated reduction of several polypeptides of the mitochondrial respiratory chain, including Rieske and cytochrome c1 subunits of complex III, NADH dehydrogenase alpha subunit 5 of complex I and the catalytic core-forming subunit of F0F1-ATP synthase. Taz gene knockdown resulted in upregulation of enzymes of folate and amino acid metabolic pathways in heart mitochondria, demonstrating that Taz-deficiency causes substantive metabolic remodeling in cardiac muscle. Mitochondrial respiratory chain supercomplexes are destabilized in CL-depleted mitochondria from Taz knockdown hearts resulting in disruption of the interactions between ETC and the fatty acid oxidation enzymes, very long-chain acyl-CoA dehydrogenase and long-chain 3-hydroxyacyl-CoA dehydrogenase, potentially affecting the metabolic channeling of reducing equivalents between these two metabolic pathways. Mitochondria-bound myoglobin was significantly reduced in Taz-knockdown hearts, potentially disrupting intracellular oxygen delivery to the oxidative phosphorylation system. Our results identify the critical pathways affected by the Taz-deficiency in mitochondria and establish a future framework for development of therapeutic options for BTHS. PMID:26030409

  17. Effect of Chromium Supplementation on Element Distribution in a Mouse Model of Polycystic Ovary Syndrome.

    PubMed

    Chen, Tsung-Sheng; Chen, Yi-Ting; Liu, Chia-Hsin; Sun, Chi-Ching; Mao, Frank Chiahung

    2015-12-01

    Polycystic ovary syndrome (PCOS) is a complex endocrine disorder and one of the most common causes of anovulatory infertility. In addition, insulin resistance is commonly associated with PCOS and contributed to pathophysiology connected to dietary minerals including chromium (Cr), copper (Cu), iron (Fe), and zinc (Zn). The aims of this study were to explore whether PCOS in mice alters levels of these elements and determine if Cr supplementation resolves changes. Twenty-four female BALB/c mice were divided into three groups of eight mice [normal control (NC), PCOS+placebo milk (PP), and PCOS+Cr-containing milk (PCr)]. Each group received a high-fat diet for 4 weeks. Our results show significantly higher levels of dehydroepiandrosterone (DHEA) (p<0.001), fasting glucose (p<0.05), and fasting insulin (p<0.05) in the PP group compared with both NC and PCr group. However, Cr levels were significantly lower in muscle, bone, and serum in the PP group (p<0.05) compared with NC and PCr groups. In liver, bone, and serum, Fe levels were significantly higher in the PP group compared with the NC group (p<0.05). In addition, we found significant correlations between Cu/Zn ratio and fasting insulin in all mice (r=0.61; p=0.002). Given that significant research shows that Cr supplementation improves fasting glucose, fasting insulin, and metal metabolism disorders for PCOS mice, our data suggest that trace element levels can serve as biomarkers to prescribe therapeutic supplementation to maintain a healthy metabolic balance and treat disease conditions. PMID:26041153

  18. Decreased Hering-Breuer input-output entrainment in a mouse model of Rett syndrome.

    PubMed

    Dhingra, Rishi R; Zhu, Yenan; Jacono, Frank J; Katz, David M; Galán, Roberto F; Dick, Thomas E

    2013-01-01

    Rett syndrome, a severe X-linked neurodevelopmental disorder caused by mutations in the gene encoding methyl-CpG-binding protein 2 (Mecp2), is associated with a highly irregular respiratory pattern including severe upper-airway dysfunction. Recent work suggests that hyperexcitability of the Hering-Breuer reflex (HBR) pathway contributes to respiratory dysrhythmia in Mecp2 mutant mice. To assess how enhanced HBR input impacts respiratory entrainment by sensory afferents in closed-loop in vivo-like conditions, we investigated the input (vagal stimulus trains) - output (phrenic bursting) entrainment via the HBR in wild-type and MeCP2-deficient mice. Using the in situ perfused brainstem preparation, which maintains an intact pontomedullary axis capable of generating an in vivo-like respiratory rhythm in the absence of the HBR, we mimicked the HBR feedback input by stimulating the vagus nerve (at threshold current, 0.5 ms pulse duration, 75 Hz pulse frequency, 100 ms train duration) at an inter-burst frequency matching that of the intrinsic oscillation of the inspiratory motor output of each preparation. Using this approach, we observed significant input-output entrainment in wild-type mice as measured by the maximum of the cross-correlation function, the peak of the instantaneous relative phase distribution, and the mutual information of the instantaneous phases. This entrainment was associated with a reduction in inspiratory duration during feedback stimulation. In contrast, the strength of input-output entrainment was significantly weaker in Mecp2 (-/+) mice. However, Mecp2 (-/+) mice also had a reduced inspiratory duration during stimulation, indicating that reflex behavior in the HBR pathway was intact. Together, these observations suggest that the respiratory network compensates for enhanced sensitivity of HBR inputs by reducing HBR input-output entrainment. PMID:23565077

  19. Cardiac metabolic pathways affected in the mouse model of barth syndrome.

    PubMed

    Huang, Yan; Powers, Corey; Madala, Satish K; Greis, Kenneth D; Haffey, Wendy D; Towbin, Jeffrey A; Purevjav, Enkhsaikhan; Javadov, Sabzali; Strauss, Arnold W; Khuchua, Zaza

    2015-01-01

    Cardiolipin (CL) is a mitochondrial phospholipid essential for electron transport chain (ETC) integrity. CL-deficiency in humans is caused by mutations in the tafazzin (Taz) gene and results in a multisystem pediatric disorder, Barth syndrome (BTHS). It has been reported that tafazzin deficiency destabilizes mitochondrial respiratory chain complexes and affects supercomplex assembly. The aim of this study was to investigate the impact of Taz-knockdown on the mitochondrial proteomic landscape and metabolic processes, such as stability of respiratory chain supercomplexes and their interactions with fatty acid oxidation enzymes in cardiac muscle. Proteomic analysis demonstrated reduction of several polypeptides of the mitochondrial respiratory chain, including Rieske and cytochrome c1 subunits of complex III, NADH dehydrogenase alpha subunit 5 of complex I and the catalytic core-forming subunit of F0F1-ATP synthase. Taz gene knockdown resulted in upregulation of enzymes of folate and amino acid metabolic pathways in heart mitochondria, demonstrating that Taz-deficiency causes substantive metabolic remodeling in cardiac muscle. Mitochondrial respiratory chain supercomplexes are destabilized in CL-depleted mitochondria from Taz knockdown hearts resulting in disruption of the interactions between ETC and the fatty acid oxidation enzymes, very long-chain acyl-CoA dehydrogenase and long-chain 3-hydroxyacyl-CoA dehydrogenase, potentially affecting the metabolic channeling of reducing equivalents between these two metabolic pathways. Mitochondria-bound myoglobin was significantly reduced in Taz-knockdown hearts, potentially disrupting intracellular oxygen delivery to the oxidative phosphorylation system. Our results identify the critical pathways affected by the Taz-deficiency in mitochondria and establish a future framework for development of therapeutic options for BTHS. PMID:26030409

  20. p53 suppression partially rescues the mutant phenotype in mouse models of DiGeorge syndrome

    PubMed Central

    Caprio, Cinzia; Baldini, Antonio

    2014-01-01

    T-box 1 (Tbx1), a gene encoding a T-box transcription factor, is required for embryonic development in humans and mice. Half dosage of this gene in humans causes most of the features of the DiGeorge or Velocardiofacial syndrome phenotypes, including aortic arch and cardiac outflow tract abnormalities. Here we found a strong genetic interaction between Tbx1 and transformation related protein 53 (Trp53). Indeed, genetic ablation of Trp53, or pharmacological inhibition of its protein product p53, rescues significantly the cardiovascular defects of Tbx1 heterozygous and hypomorphic mutants. We found that the Tbx1 and p53 proteins do not interact directly but both occupy a genetic element of Gbx2, which is required for aortic arch and cardiac outflow tract development, and is a known genetic interactor of Tbx1. We found that Gbx2 expression is down-regulated in Tbx1+/− embryos and is restored to normal levels in Tbx1+/−;Trp53+/− embryos. In addition, we found that the genetic element that binds both Tbx1 and p53 is highly enriched in H3K27 trimethylation, and upon p53 suppression H3K27me3 levels are reduced, along with Ezh2 enrichment. This finding suggests that the rescue of Gbx2 expression in Tbx1+/−;Trp53+/− embryos is due to reduction of repressive chromatin marks. Overall our data identify unexpected genetic interactions between Tbx1 and Trp53 and provide a proof of principle that developmental defects associated with reduced dosage of Tbx1 can be rescued pharmacologically. PMID:25197075

  1. The VCD Mouse Model of Menopause and Perimenopause for the Study of Sex Differences in Cardiovascular Disease and the Metabolic Syndrome.

    PubMed

    Brooks, H L; Pollow, D P; Hoyer, P B

    2016-07-01

    In females, menopause, the cessation of menstrual cycling, is associated with an increase in risk for several diseases such as cardiovascular disease, osteoporosis, diabetes, the metabolic syndrome, and ovarian cancer. The majority of women enter menopause via a gradual reduction of ovarian function over several years (perimenopause) and retain residual ovarian tissue. The VCD mouse model of menopause (ovarian failure in rodents) is a follicle-deplete, ovary-intact animal that more closely approximates the natural human progression through perimenopause and into the postmenopausal stage of life. In this review, we present the physiological parameters of how to use the VCD model and explore the VCD model and its application into the study of postmenopausal disease mechanisms, focusing on recent murine studies of diabetic kidney disease, the metabolic syndrome, and hypertension. PMID:27252160

  2. Memory and Learning--Using Mouse to Model Neurobiological and Behavioural Aspects of Down Syndrome and Assess Pharmacotherapeutics

    ERIC Educational Resources Information Center

    Gardiner, Katheleen

    2009-01-01

    Mouse models are a standard tool in the study of many human diseases, providing insights into the normal functions of a gene, how these are altered in disease and how they contribute to a disease process, as well as information on drug action, efficacy and side effects. Our knowledge of human genes, their genetics, functions, interactions and…

  3. Comprehensive Behavioral Phenotyping of Ts65Dn Mouse Model of Down Syndrome: Activation of β1-Adrenergic Receptor by Xamoterol as a Potential Cognitive Enhancer

    PubMed Central

    Faizi, Mehrdad; Bader, Patrick L.; Tun, Christine; Encarnacion, Angelo; Kleschevnikov, Alexander; Belichenko, Pavel; Saw, Nay; Priestley, Matthew; Tsien, Richard W; Mobley, William C; Shamloo, Mehrdad

    2012-01-01

    Down Syndrome (DS) is the most prevalent form of mental retardation caused by genetic abnormalities in humans. This has been successfully modeled in mice to generate the Ts65Dn mouse, a genetic model of DS. This transgenic mouse model shares a number of physical and functional abnormalities with people with DS, including changes in the structure and function of neuronal circuits. Significant abnormalities in noradrenergic (NE-ergic) afferents from the locus coeruleus to the hippocampus, as well as deficits in NE-ergic neurotransmission are detected in these animals. In the current study we characterized in detail the behavioral phenotype of Ts65Dn mice, in addition to using pharmacological tools for identification of target receptors mediating the learning and memory deficits observed in this model of DS. We undertook a comprehensive approach to mouse phenotyping using a battery of standard and novel tests encompassing: i) locomotion (Activity Chamber, PhenoTyper, and CatWalk), ii) learning and memory (spontaneous alternation, delayed matching-to-place water maze, fear conditioning, and Intellicage), and iii) social behavior. Ts65Dn mice showed increased locomotor activity in novel and home cage environments. There were significant and reproducible deficits in learning and memory tests including spontaneous alternation, delayed matching-to-place water maze, Intellicage place avoidance and contextual fear conditioning. Although Ts65Dn mice showed no deficit in sociability in the 3-chamber test, a marked impairment in social memory was detected. Xamoterol, a β1-adrenergic receptor (β1-ADR) agonist, effectively restored the memory deficit in contextual fear conditioning, spontaneous alternation and novel object recognition. These behavioral improvements were reversed by betaxolol, a selective β1-ADR antagonist. In conclusion, our results demonstrate that this mouse model of Down Syndrome display cognitive deficits which is mediated by imbalance in noradrenergic

  4. Systems analysis of primary Sjögren's syndrome pathogenesis in salivary glands identifies shared pathways in human and a mouse model

    PubMed Central

    2012-01-01

    Introduction Primary Sjögren's syndrome (pSS) is a chronic autoimmune disease with complex etiopathogenesis. Despite extensive studies to understand the disease process utilizing human and mouse models, the intersection between these species remains elusive. To address this gap, we utilized a novel systems biology approach to identify disease-related gene modules and signaling pathways that overlap between humans and mice. Methods Parotid gland tissues were harvested from 24 pSS and 16 non-pSS sicca patients and 25 controls. For mouse studies, salivary glands were harvested from C57BL/6.NOD-Aec1Aec2 mice at various times during development of pSS-like disease. RNA was analyzed with Affymetrix HG U133+2.0 arrays for human samples and with MOE430+2.0 arrays for mouse samples. The images were processed with Affymetrix software. Weighted-gene co-expression network analysis was used to identify disease-related and functional pathways. Results Nineteen co-expression modules were identified in human parotid tissue, of which four were significantly upregulated and three were downregulated in pSS patients compared with non-pSS sicca patients and controls. Notably, one of the human disease-related modules was highly preserved in the mouse model, and was enriched with genes involved in immune and inflammatory responses. Further comparison between these two species led to the identification of genes associated with leukocyte recruitment and germinal center formation. Conclusion Our systems biology analysis of genome-wide expression data from salivary gland tissue of pSS patients and from a pSS mouse model identified common dysregulated biological pathways and molecular targets underlying critical molecular alterations in pSS pathogenesis. PMID:23116360

  5. Rescue of bilirubin-induced neonatal lethality in a mouse model of Crigler-Najjar syndrome type I by AAV9-mediated gene transfer

    PubMed Central

    Bortolussi, Giulia; Zentilin, Lorena; Baj, Gabriele; Giraudi, Pablo; Bellarosa, Cristina; Giacca, Mauro; Tiribelli, Claudio; Muro, Andrés F.

    2012-01-01

    Crigler-Najjar type I (CNI) syndrome is a recessively inherited disorder characterized by severe unconjugated hyperbilirubinemia caused by uridine diphosphoglucuronosyltransferase 1A1 (UGT1A1) deficiency. The disease is lethal due to bilirubin-induced neurological damage unless phototherapy is applied from birth. However, treatment becomes less effective during growth, and liver transplantation is required. To investigate the pathophysiology of the disease and therapeutic approaches in mice, we generated a mouse model by introducing a premature stop codon in the UGT1a1 gene, which results in an inactive enzyme. Homozygous mutant mice developed severe jaundice soon after birth and died within 11 d, showing significant cerebellar alterations. To rescue neonatal lethality, newborns were injected with a single dose of adeno-associated viral vector 9 (AAV9) expressing the human UGT1A1. Gene therapy treatment completely rescued all AAV-treated mutant mice, accompanied by lower plasma bilirubin levels and normal brain histology and motor coordination. Our mouse model of CNI reproduces genetic and phenotypic features of the human disease. We have shown, for the first time, the full recovery of the lethal effects of neonatal hyperbilirubinemia. We believe that, besides gene-addition-based therapies, our mice could represent a very useful model to develop and test novel technologies based on gene correction by homologous recombination.—Bortolussi, G., Zentilin, L., Baj, G., Giraudi, P., Bellarosa, C., Giacca, M., Tiribelli, C., Muro, A. F. Rescue of bilirubin-induced neonatal lethality in a mouse model of Crigler-Najjar syndrome type I by AAV9-mediated gene transfer. PMID:22094718

  6. Partial BACE1 reduction in a Down syndrome mouse model blocks Alzheimer-related endosomal anomalies and cholinergic neurodegeneration: role of APP-CTF.

    PubMed

    Jiang, Ying; Rigoglioso, Andrew; Peterhoff, Corrinne M; Pawlik, Monika; Sato, Yutaka; Bleiwas, Cynthia; Stavrides, Philip; Smiley, John F; Ginsberg, Stephen D; Mathews, Paul M; Levy, Efrat; Nixon, Ralph A

    2016-03-01

    β-amyloid precursor protein (APP) and amyloid beta peptide (Aβ) are strongly implicated in Alzheimer's disease (AD) pathogenesis, although recent evidence has linked APP-βCTF generated by BACE1 (β-APP cleaving enzyme 1) to the development of endocytic abnormalities and cholinergic neurodegeneration in early AD. We show that partial BACE1 genetic reduction prevents these AD-related pathological features in the Ts2 mouse model of Down syndrome. Partially reducing BACE1 by deleting one BACE1 allele blocked development of age-related endosome enlargement in the medial septal nucleus, cerebral cortex, and hippocampus and loss of choline acetyltransferase (ChAT)-positive medial septal nucleus neurons. BACE1 reduction normalized APP-βCTF elevation but did not alter Aβ40 and Aβ42 peptide levels in brain, supporting a critical role in vivo for APP-βCTF in the development of these abnormalities. Although ameliorative effects of BACE1 inhibition on β-amyloidosis and synaptic proteins levels have been previously noted in AD mouse models, our results highlight the additional potential value of BACE1 modulation in therapeutic targeting of endocytic dysfunction and cholinergic neurodegeneration in Down syndrome and AD. PMID:26923405

  7. Mitochondrial free radical overproduction due to respiratory chain impairment in the brain of a mouse model of Rett syndrome: protective effect of CNF1.

    PubMed

    De Filippis, Bianca; Valenti, Daniela; de Bari, Lidia; De Rasmo, Domenico; Musto, Mattia; Fabbri, Alessia; Ricceri, Laura; Fiorentini, Carla; Laviola, Giovanni; Vacca, Rosa Anna

    2015-06-01

    Rett syndrome (RTT) is a pervasive neurodevelopmental disorder mainly caused by mutations in the X-linked MECP2 gene associated with severe intellectual disability, movement disorders, and autistic-like behaviors. Its pathogenesis remains mostly not understood and no effective therapy is available. High circulating levels of oxidative stress markers in patients and the occurrence of oxidative brain damage in MeCP2-deficient mouse models suggest the involvement of oxidative stress in RTT pathogenesis. However, the molecular mechanism and the origin of the oxidative stress have not been elucidated. Here we demonstrate that a redox imbalance arises from aberrant mitochondrial functionality in the brain of MeCP2-308 heterozygous female mice, a condition that more closely recapitulates that of RTT patients. The marked increase in the rate of hydrogen peroxide generation in the brain of RTT mice seems mainly produced by the dysfunctional complex II of the mitochondrial respiratory chain. In addition, both membrane potential generation and mitochondrial ATP synthesis are decreased in RTT mouse brains when succinate, the complex II respiratory substrate, is used as an energy source. Respiratory chain impairment is brain area specific, owing to a decrease in either cAMP-dependent phosphorylation or protein levels of specific complex subunits. Further, we investigated whether the treatment of RTT mice with the bacterial protein CNF1, previously reported to ameliorate the neurobehavioral phenotype and brain bioenergetic markers in an RTT mouse model, exerts specific effects on brain mitochondrial function and consequently on hydrogen peroxide production. In RTT brains treated with CNF1, we observed the reactivation of respiratory chain complexes, the rescue of mitochondrial functionality, and the prevention of brain hydrogen peroxide overproduction. These results provide definitive evidence of mitochondrial reactive oxygen species overproduction in RTT mouse brain and

  8. An Abnormal Nitric Oxide Metabolism Contributes to Brain Oxidative Stress in the Mouse Model for the Fragile X Syndrome, a Possible Role in Intellectual Disability

    PubMed Central

    Lima-Cabello, Elena; Garcia-Guirado, Francisco; Calvo-Medina, Rocio; el Bekay, Rajaa; Perez-Costillas, Lucia; Quintero-Navarro, Carolina; Sanchez-Salido, Lourdes

    2016-01-01

    Background. Fragile X syndrome is the most common genetic cause of mental disability. Although many research has been performed, the mechanism underlying the pathogenesis is unclear and needs further investigation. Oxidative stress played major roles in the syndrome. The aim was to investigate the nitric oxide metabolism, protein nitration level, the expression of NOS isoforms, and furthermore the activation of the nuclear factor NF-κB-p65 subunit in different brain areas on the fragile X mouse model. Methods. This study involved adult male Fmr1-knockout and wild-type mice as controls. We detected nitric oxide metabolism and the activation of the nuclear factor NF-κBp65 subunit, comparing the mRNA expression and protein content of the three NOS isoforms in different brain areas. Results. Fmr1-KO mice showed an abnormal nitric oxide metabolism and increased levels of protein tyrosine nitrosylation. Besides that, nuclear factor NF-κB-p65 and inducible nitric oxide synthase appeared significantly increased in the Fmr1-knockout mice. mRNA and protein levels of the neuronal nitric oxide synthase appeared significantly decreased in the knockout mice. However, the epithelial nitric oxide synthase isoform displayed no significant changes. Conclusions. These data suggest the potential involvement of an abnormal nitric oxide metabolism in the pathogenesis of the fragile X syndrome. PMID:26788253

  9. Altered Cortical GABAA Receptor Composition, Physiology, and Endocytosis in a Mouse Model of a Human Genetic Absence Epilepsy Syndrome*

    PubMed Central

    Zhou, Chengwen; Huang, Zhiling; Ding, Li; Deel, M. Elizabeth; Arain, Fazal M.; Murray, Clark R.; Patel, Ronak S.; Flanagan, Christopher D.; Gallagher, Martin J.

    2013-01-01

    Patients with generalized epilepsy exhibit cerebral cortical disinhibition. Likewise, mutations in the inhibitory ligand-gated ion channels, GABAA receptors (GABAARs), cause generalized epilepsy syndromes in humans. Recently, we demonstrated that heterozygous knock-out (Hetα1KO) of the human epilepsy gene, the GABAAR α1 subunit, produced absence epilepsy in mice. Here, we determined the effects of Hetα1KO on the expression and physiology of GABAARs in the mouse cortex. We found that Hetα1KO caused modest reductions in the total and surface expression of the β2 subunit but did not alter β1 or β3 subunit expression, results consistent with a small reduction of GABAARs. Cortices partially compensated for Hetα1KO by increasing the fraction of residual α1 subunit on the cell surface and by increasing total and surface expression of α3, but not α2, subunits. Co-immunoprecipitation experiments revealed that Hetα1KO increased the fraction of α1 subunits, and decreased the fraction of α3 subunits, that associated in hybrid α1α3βγ receptors. Patch clamp electrophysiology studies showed that Hetα1KO layer VI cortical neurons exhibited reduced inhibitory postsynaptic current peak amplitudes, prolonged current rise and decay times, and altered responses to benzodiazepine agonists. Finally, application of inhibitors of dynamin-mediated endocytosis revealed that Hetα1KO reduced base-line GABAAR endocytosis, an effect that probably contributes to the observed changes in GABAAR expression. These findings demonstrate that Hetα1KO exerts two principle disinhibitory effects on cortical GABAAR-mediated inhibitory neurotransmission: 1) a modest reduction of GABAAR number and 2) a partial compensation with GABAAR isoforms that possess physiological properties different from those of the otherwise predominant α1βγ GABAARs. PMID:23744069

  10. Doxycycline ameliorates the susceptibility to aortic lesions in a mouse model for the vascular type of Ehlers-Danlos syndrome.

    PubMed

    Briest, Wilfried; Cooper, Timothy K; Tae, Hyun-Jin; Krawczyk, Melissa; McDonnell, Nazli B; Talan, Mark I

    2011-06-01

    The vascular form of Ehlers-Danlos syndrome (vEDS), a rare disease with grave complications resulting from rupture of major arteries, is caused by mutations of collagen type III [α1 chain of collagen type III (COL3A1)]. The only, recently proven, preventive strategy consists of the reduction of arterial wall stress by β-adrenergic blockers. The heterozygous (HT) Col3a1 knockout mouse has reduced expression of collagen III and recapitulates features of a mild presentation of the disease. The objective of this study was to determine whether changing the balance between synthesis and degradation of collagen by chronic treatment with doxycycline, a nonspecific matrix metalloproteinase (MMP) inhibitor, could prevent the development of vascular pathology in HT mice. After 3 months of treatment with doxycycline or placebo, 9-month-old HT or wild-type (WT) mice were subjected to surgical stressing of the aorta. A 3-fold increase in stress-induced aortic lesions found in untreated HT mice 1 week after intervention (cumulative score 4.5 ± 0.87 versus 1.3 ± 0.34 in WT, p < 0.001) was fully prevented in the doxycycline-treated group (1.1 ± 0.56, p < 0.001). Untreated HT mice showed increased MMP-9 activity in the carotid artery and decreased collagen content in the aorta; however, in doxycycline-treated animals there was normalization to the levels observed in WT mice. Doxycycline treatment inhibits the activity of tissue MMP and attenuates the decrease in the collagen content in aortas of mice haploinsufficient for collagen III, as well as prevents the development of stress-induced vessel pathology. The results suggest that doxycycline merits clinical testing as a treatment for vEDS. PMID:21363928

  11. Lack of Pwcr1/MBII-85 snoRNA is critical for neonatal lethality in Prader-Willi syndrome mouse models

    SciTech Connect

    Ding, Feng; Prints, Yelena; Dhar, Madhu; Johnson, Dabney K; Garnacho-Montero, Carmen; Nicholls, Robert; Francke, Uta

    2005-01-01

    Prader-Willi syndrome (PWS) is a neurobehavioral disorder caused by the lack of paternal expression of imprinted genes in the human chromosome region 15q11-13. Recent studies of rare human translocation patients narrowed the PWS critical genes to a 121-kb region containing PWCR1/HBII-85 and HBII-438 snoRNA genes. The existing mouse models of PWS that lack the expression of multiple genes, including Snrpn, Ube3a, and many intronic snoRNA genes, are characterized by 80%-100% neonatal lethality. To define the candidate region for PWS-like phenotypes in mice,we analyzed the expression of several genetic elements in mice carrying the large radiation-induced p30PUb deletion that includes the p locus. Mice having inherited this deletion from either parent develop normally into adulthood. By Northern blot and RTPCR assays of brain tissue, we found that Pwcr1/MBII-85 snoRNAs are expressed normally, while MBII-52 snoRNAs are not expressed when the deletion is paternally inherited. Mapping of the distal deletion breakpoint indicated that the p30PUb deletion includes the entire MBII-52 snoRNA gene cluster and three previously unmapped EST sequences. The lack of expression of these elements in mice with a paternal p30PUb deletion indicates that they are not critical for the neonatal lethality observed in PWS mouse models. In addition, we identified MBII-436, the mouse homolog of the HBII-436 snoRNA, confirmed its imprinting status, and mapped it outside of the p30PUb deletion. Taking together all available data, we conclude that the lack of Pwcr1/MBII-85 snoRNA expression is the most likely cause for the neonatal lethality in PWS model mice.

  12. Improvement of the Rett Syndrome Phenotype in a Mecp2 Mouse Model Upon Treatment with Levodopa and a Dopa-Decarboxylase Inhibitor

    PubMed Central

    Szczesna, Karolina; de la Caridad, Olga; Petazzi, Paolo; Soler, Marta; Roa, Laura; Saez, Mauricio A; Fourcade, Stéphane; Pujol, Aurora; Artuch-Iriberri, Rafael; Molero-Luis, Marta; Vidal, August; Huertas, Dori; Esteller, Manel

    2014-01-01

    Rett Syndrome is a neurodevelopmental autism spectrum disorder caused by mutations in the gene coding for methyl CpG-binding protein (MeCP2). The disease is characterized by abnormal motor, respiratory, cognitive impairment, and autistic-like behaviors. No effective treatment of the disorder is available. Mecp2 knockout mice have a range of physiological and neurological abnormalities that resemble the human syndrome and can be used as a model to interrogate new therapies. Herein, we show that the combined administration of Levodopa and a Dopa-decarboxylase inhibitor in RTT mouse models is well tolerated, diminishes RTT-associated symptoms, and increases life span. The amelioration of RTT symptomatology is particularly significant in those features controlled by the dopaminergic pathway in the nigrostratium, such as mobility, tremor, and breathing. Most important, the improvement of the RTT phenotype upon use of the combined treatment is reflected at the cellular level by the development of neuronal dendritic growth. However, much work is required to extend the duration of the benefit of the described preclinical treatment. PMID:24917201

  13. Improvement of the Rett syndrome phenotype in a MeCP2 mouse model upon treatment with levodopa and a dopa-decarboxylase inhibitor.

    PubMed

    Szczesna, Karolina; de la Caridad, Olga; Petazzi, Paolo; Soler, Marta; Roa, Laura; Saez, Mauricio A; Fourcade, Stéphane; Pujol, Aurora; Artuch-Iriberri, Rafael; Molero-Luis, Marta; Vidal, August; Huertas, Dori; Esteller, Manel

    2014-11-01

    Rett Syndrome is a neurodevelopmental autism spectrum disorder caused by mutations in the gene coding for methyl CpG-binding protein (MeCP2). The disease is characterized by abnormal motor, respiratory, cognitive impairment, and autistic-like behaviors. No effective treatment of the disorder is available. Mecp2 knockout mice have a range of physiological and neurological abnormalities that resemble the human syndrome and can be used as a model to interrogate new therapies. Herein, we show that the combined administration of Levodopa and a Dopa-decarboxylase inhibitor in RTT mouse models is well tolerated, diminishes RTT-associated symptoms, and increases life span. The amelioration of RTT symptomatology is particularly significant in those features controlled by the dopaminergic pathway in the nigrostratium, such as mobility, tremor, and breathing. Most important, the improvement of the RTT phenotype upon use of the combined treatment is reflected at the cellular level by the development of neuronal dendritic growth. However, much work is required to extend the duration of the benefit of the described preclinical treatment. PMID:24917201

  14. Slc26a4 expression prevents fluctuation of hearing in a mouse model of large vestibular aqueduct syndrome.

    PubMed

    Nishio, Ayako; Ito, Taku; Cheng, Hui; Fitzgerald, Tracy S; Wangemann, Philine; Griffith, Andrew J

    2016-08-01

    SLC26A4 mutations cause fluctuating and progressive hearing loss associated with enlargement of the vestibular aqueduct (EVA). SLC26A4 encodes a transmembrane anion exchanger called pendrin expressed in nonsensory epithelial cells of the lateral wall of cochlea, vestibular organs and endolymphatic sac. We previously described a transgenic mouse model of EVA with doxycycline (dox)-inducible expression of Slc26a4 in which administration of dox from conception to embryonic day 17.5 (DE17.5) resulted in hearing fluctuation between 1 and 3months of age. In the present study, we hypothesized that Slc26a4 is required to stabilize hearing in DE17.5 ears between 1 and 3months of age. We tested our hypothesis by evaluating the effect of postnatal re-induction of Slc26a4 expression on hearing. Readministration of dox to DE17.5 mice at postnatal day 6 (P6), but not at 1month of age, resulted in reduced click-evoked auditory brainstem response (ABR) thresholds, less fluctuation of hearing and a higher surface density of pendrin expression in spindle-shaped cells of the stria vascularis. Pendrin expression in spindle-shaped cells was inversely correlated with ABR thresholds. These findings suggest that stabilization of hearing by readministration of dox at P6 is mediated by pendrin expression in spindle-shaped cells. We conclude that early re-induction of Slc26a4 expression can prevent fluctuation of hearing in our Slc26a4-insufficient mouse model. Restoration of SLC26A4 expression and function could reduce or prevent fluctuation of hearing in EVA patients. PMID:27155149

  15. Overexpression of Dyrk1A Is Implicated in Several Cognitive, Electrophysiological and Neuromorphological Alterations Found in a Mouse Model of Down Syndrome

    PubMed Central

    García-Cerro, Susana; Martínez, Paula; Vidal, Verónica; Corrales, Andrea; Flórez, Jesús; Vidal, Rebeca; Rueda, Noemí; Arbonés, María L.; Martínez-Cué, Carmen

    2014-01-01

    Down syndrome (DS) phenotypes result from the overexpression of several dosage-sensitive genes. The DYRK1A (dual-specificity tyrosine-(Y)-phosphorylation regulated kinase 1A) gene, which has been implicated in the behavioral and neuronal alterations that are characteristic of DS, plays a role in neuronal progenitor proliferation, neuronal differentiation and long-term potentiation (LTP) mechanisms that contribute to the cognitive deficits found in DS. The purpose of this study was to evaluate the effect of Dyrk1A overexpression on the behavioral and cognitive alterations in the Ts65Dn (TS) mouse model, which is the most commonly utilized mouse model of DS, as well as on several neuromorphological and electrophysiological properties proposed to underlie these deficits. In this study, we analyzed the phenotypic differences in the progeny obtained from crosses of TS females and heterozygous Dyrk1A (+/−) male mice. Our results revealed that normalization of the Dyrk1A copy number in TS mice improved working and reference memory based on the Morris water maze and contextual conditioning based on the fear conditioning test and rescued hippocampal LTP. Concomitant with these functional improvements, normalization of the Dyrk1A expression level in TS mice restored the proliferation and differentiation of hippocampal cells in the adult dentate gyrus (DG) and the density of GABAergic and glutamatergic synapse markers in the molecular layer of the hippocampus. However, normalization of the Dyrk1A gene dosage did not affect other structural (e.g., the density of mature hippocampal granule cells, the DG volume and the subgranular zone area) or behavioral (i.e., hyperactivity/attention) alterations found in the TS mouse. These results suggest that Dyrk1A overexpression is involved in some of the cognitive, electrophysiological and neuromorphological alterations, but not in the structural alterations found in DS, and suggest that pharmacological strategies targeting this gene

  16. Overexpression of Dyrk1A is implicated in several cognitive, electrophysiological and neuromorphological alterations found in a mouse model of Down syndrome.

    PubMed

    García-Cerro, Susana; Martínez, Paula; Vidal, Verónica; Corrales, Andrea; Flórez, Jesús; Vidal, Rebeca; Rueda, Noemí; Arbonés, María L; Martínez-Cué, Carmen

    2014-01-01

    Down syndrome (DS) phenotypes result from the overexpression of several dosage-sensitive genes. The DYRK1A (dual-specificity tyrosine-(Y)-phosphorylation regulated kinase 1A) gene, which has been implicated in the behavioral and neuronal alterations that are characteristic of DS, plays a role in neuronal progenitor proliferation, neuronal differentiation and long-term potentiation (LTP) mechanisms that contribute to the cognitive deficits found in DS. The purpose of this study was to evaluate the effect of Dyrk1A overexpression on the behavioral and cognitive alterations in the Ts65Dn (TS) mouse model, which is the most commonly utilized mouse model of DS, as well as on several neuromorphological and electrophysiological properties proposed to underlie these deficits. In this study, we analyzed the phenotypic differences in the progeny obtained from crosses of TS females and heterozygous Dyrk1A (+/-) male mice. Our results revealed that normalization of the Dyrk1A copy number in TS mice improved working and reference memory based on the Morris water maze and contextual conditioning based on the fear conditioning test and rescued hippocampal LTP. Concomitant with these functional improvements, normalization of the Dyrk1A expression level in TS mice restored the proliferation and differentiation of hippocampal cells in the adult dentate gyrus (DG) and the density of GABAergic and glutamatergic synapse markers in the molecular layer of the hippocampus. However, normalization of the Dyrk1A gene dosage did not affect other structural (e.g., the density of mature hippocampal granule cells, the DG volume and the subgranular zone area) or behavioral (i.e., hyperactivity/attention) alterations found in the TS mouse. These results suggest that Dyrk1A overexpression is involved in some of the cognitive, electrophysiological and neuromorphological alterations, but not in the structural alterations found in DS, and suggest that pharmacological strategies targeting this gene may

  17. Neuromuscular junction immaturity and muscle atrophy are hallmarks of the ColQ-deficient mouse, a model of congenital myasthenic syndrome with acetylcholinesterase deficiency.

    PubMed

    Sigoillot, Séverine M; Bourgeois, Francine; Karmouch, Jennifer; Molgó, Jordi; Dobbertin, Alexandre; Chevalier, Catherine; Houlgatte, Rémi; Léger, Jean; Legay, Claire

    2016-06-01

    The collagen ColQ anchors acetylcholinesterase (AChE) in the synaptic cleft of the neuromuscular junction (NMJ). It also binds MuSK and perlecan/dystroglycan, 2 signaling platforms of the postsynaptic domain. Mutations in ColQ cause a congenital myasthenic syndrome (CMS) with AChE deficiency. Because the absence of AChE does not fully explain the complexity of the syndrome and there is no curative treatment for the disease, we explored additional potential targets of ColQ by conducting a large genetic screening of ColQ-deficient mice, a model for CMS with AChE deficiency, and analyzed their NMJ and muscle phenotypes. We demonstrated that ColQ controls the development and the maturation of the postsynaptic domain by regulating synaptic gene expression. Notably, ColQ deficiency leads to an up-regulation of the 5 subunits of the nicotinic acetylcholine receptor (AChR), leading to mixed mature and immature AChRs at the NMJ of adult mice. ColQ also regulates the expression of extracellular matrix (ECM) components. However, whereas the ECM mRNAs were down-regulated in vitro, compensation seemed to occur in vivo to maintain normal levels of these mRNAs. Finally, ColQ deficiency leads to a general atrophic phenotype and hypoplasia that affect fast muscles. This study points to new specific hallmarks for this CMS.-Sigoillot, S. M., Bourgeois, F., Karmouch, J., Molgó, J., Dobbertin, A., Chevalier, C., Houlgatte, R., Léger, J., Legay, C. Neuromuscular junction immaturity and muscle atrophy are hallmarks of the ColQ-deficient mouse, a model of congenital myasthenic syndrome with acetylcholinesterase deficiency. PMID:26993635

  18. Virally mediated Kcnq1 gene replacement therapy in the immature scala media restores hearing in a mouse model of human Jervell and Lange-Nielsen deafness syndrome

    PubMed Central

    Chang, Qing; Wang, Jianjun; Li, Qi; Kim, Yeunjung; Zhou, Binfei; Wang, Yunfeng; Li, Huawei; Lin, Xi

    2015-01-01

    Mutations in the potassium channel subunit KCNQ1 cause the human severe congenital deafness Jervell and Lange-Nielsen (JLN) syndrome. We applied a gene therapy approach in a mouse model of JLN syndrome (Kcnq1−/− mice) to prevent the development of deafness in the adult stage. A modified adeno-associated virus construct carrying a Kcnq1 expression cassette was injected postnatally (P0–P2) into the endolymph, which resulted in Kcnq1 expression in most cochlear marginal cells where native Kcnq1 is exclusively expressed. We also found that extensive ectopic virally mediated Kcnq1 transgene expression did not affect normal cochlear functions. Examination of cochlear morphology showed that the collapse of the Reissner’s membrane and degeneration of hair cells (HCs) and cells in the spiral ganglia were corrected in Kcnq1−/− mice. Electrophysiological tests showed normal endocochlear potential in treated ears. In addition, auditory brainstem responses showed significant hearing preservation in the injected ears, ranging from 20 dB improvement to complete correction of the deafness phenotype. Our results demonstrate the first successful gene therapy treatment for gene defects specifically affecting the function of the stria vascularis, which is a major site affected by genetic mutations in inherited hearing loss. PMID:26084842

  19. Virally mediated Kcnq1 gene replacement therapy in the immature scala media restores hearing in a mouse model of human Jervell and Lange-Nielsen deafness syndrome.

    PubMed

    Chang, Qing; Wang, Jianjun; Li, Qi; Kim, Yeunjung; Zhou, Binfei; Wang, Yunfeng; Li, Huawei; Lin, Xi

    2015-08-01

    Mutations in the potassium channel subunit KCNQ1 cause the human severe congenital deafness Jervell and Lange-Nielsen (JLN) syndrome. We applied a gene therapy approach in a mouse model of JLN syndrome (Kcnq1(-/-) mice) to prevent the development of deafness in the adult stage. A modified adeno-associated virus construct carrying a Kcnq1 expression cassette was injected postnatally (P0-P2) into the endolymph, which resulted in Kcnq1 expression in most cochlear marginal cells where native Kcnq1 is exclusively expressed. We also found that extensive ectopic virally mediated Kcnq1 transgene expression did not affect normal cochlear functions. Examination of cochlear morphology showed that the collapse of the Reissner's membrane and degeneration of hair cells (HCs) and cells in the spiral ganglia were corrected in Kcnq1(-/-) mice. Electrophysiological tests showed normal endocochlear potential in treated ears. In addition, auditory brainstem responses showed significant hearing preservation in the injected ears, ranging from 20 dB improvement to complete correction of the deafness phenotype. Our results demonstrate the first successful gene therapy treatment for gene defects specifically affecting the function of the stria vascularis, which is a major site affected by genetic mutations in inherited hearing loss. PMID:26084842

  20. Abnormal Expression of the GIRK2 Potassium Channel in Hippocampus, Frontal Cortex and Substantia Nigra of Ts65Dn Mouse: A Model of Down Syndrome

    PubMed Central

    Harashima, Chie; Jacobowitz, David M.; Witta, Jassir; Borke, Rosemary C.; Best, Tyler K.; Siarey, Richard J.; Galdzicki, Zygmunt

    2010-01-01

    Ts65Dn, a mouse model of Down syndrome (DS), demonstrates abnormal hippocampal synaptic plasticity and behavioral abnormalities related to spatial learning and memory. The molecular mechanisms leading to these impairments have not been identified. In this study, we focused on the G-protein-activated inwardly rectifying potassium channel 2 (GIRK2) gene that is highly expressed in the hippocampus region. We studied the expression pattern of GIRK subunits in Ts65Dn and found that GIRK2 was over-expressed in all analyzed Ts65Dn brain regions. Interestingly elevated levels of GIRK2 protein in the Ts65Dn hippocampus and frontal cortex correlated with elevated levels of GIRK1 protein. This suggests that heteromeric GIRK1-GIRK2 channels are over-expressed in Ts65Dn hippocampus and frontal cortex, which could impair excitatory input, modulate spike frequency and synaptic kinetics in the affected regions. All GIRK2 splicing isoforms examined were expressed at higher levels in the Ts65Dn in comparison to the diploid hippocampus. The pattern of GIRK2 expression in the Ts65Dn mouse brain revealed by in situ hybridization and immunohistochemistry was similar to that previously reported in the rodent brain. However, in the Ts65Dn mouse a strong immunofluorescent staining of GIRK2 was detected in the lacunosum molecular layer of the CA3 area of the hippocampus. In addition, tyrosine hydroxylase containing dopaminergic neurons that co-express GIRK2 were more numerous in the substantia nigra compacta and ventral tegmental area in the Ts65Dn compared to diploid controls. In summary, the regional localization and the increased brain levels coupled with known function of the GIRK channel may suggest an important contribution of GIRK2 containing channels to Ts65Dn and thus to DS neurophysiological phenotypes. PMID:16374808

  1. KRAS Mouse Models

    PubMed Central

    O’Hagan, Rónán C.; Heyer, Joerg

    2011-01-01

    KRAS is a potent oncogene and is mutated in about 30% of all human cancers. However, the biological context of KRAS-dependent oncogenesis is poorly understood. Genetically engineered mouse models of cancer provide invaluable tools to study the oncogenic process, and insights from KRAS-driven models have significantly increased our understanding of the genetic, cellular, and tissue contexts in which KRAS is competent for oncogenesis. Moreover, variation among tumors arising in mouse models can provide insight into the mechanisms underlying response or resistance to therapy in KRAS-dependent cancers. Hence, it is essential that models of KRAS-driven cancers accurately reflect the genetics of human tumors and recapitulate the complex tumor-stromal intercommunication that is manifest in human cancers. Here, we highlight the progress made in modeling KRAS-dependent cancers and the impact that these models have had on our understanding of cancer biology. In particular, the development of models that recapitulate the complex biology of human cancers enables translational insights into mechanisms of therapeutic intervention in KRAS-dependent cancers. PMID:21779503

  2. Mouse Models of Acute Respiratory Distress Syndrome: A Review of Analytical Approaches, Pathologic Features, and Common Measurements.

    PubMed

    Aeffner, Famke; Bolon, Brad; Davis, Ian C

    2015-12-01

    Acute respiratory distress syndrome (ARDS) is a severe pulmonary reaction requiring hospitalization, which is incited by many causes, including bacterial and viral pneumonia as well as near drowning, aspiration of gastric contents, pancreatitis, intravenous drug use, and abdominal trauma. In humans, ARDS is very well defined by a list of clinical parameters. However, until recently no consensus was available regarding the criteria of ARDS that should be evident in an experimental animal model. This lack was rectified by a 2011 workshop report by the American Thoracic Society, which defined the main features proposed to delineate the presence of ARDS in laboratory animals. These should include histological changes in parenchymal tissue, altered integrity of the alveolar capillary barrier, inflammation, and abnormal pulmonary function. Murine ARDS models typically are defined by such features as pulmonary edema and leukocyte infiltration in cytological preparations of bronchoalveolar lavage fluid and/or lung sections. Common pathophysiological indicators of ARDS in mice include impaired pulmonary gas exchange and histological evidence of inflammatory infiltrates into the lung. Thus, morphological endpoints remain a vital component of data sets assembled from animal ARDS models. PMID:26296628

  3. Synaptic plasticity and spatial working memory are impaired in the CD mouse model of Williams-Beuren syndrome.

    PubMed

    Borralleras, Cristina; Mato, Susana; Amédée, Thierry; Matute, Carlos; Mulle, Christophe; Pérez-Jurado, Luis A; Campuzano, Victoria

    2016-01-01

    Mice heterozygous for a complete deletion (CD) equivalent to the most common deletion found in individuals with Williams-Beuren syndrome (WBS) recapitulate relevant features of the neurocognitive phenotype, such as hypersociability, along with some neuroanatomical alterations in specific brain areas. However, the pathophysiological mechanisms underlying these phenotypes still remain largely unknown. We have studied the synaptic function and cognition in CD mice using hippocampal slices and a behavioral test sensitive to hippocampal function. We have found that long-term potentiation (LTP) elicited by theta burst stimulation (TBS) was significantly impaired in hippocampal field CA1 of CD animals. This deficit might be associated with the observed alterations in spatial working memory. However, we did not detect changes in presynaptic function, LTP induction mechanisms or AMPA and NMDA receptor function. Reduced levels of Brain-derived neurotrophic factor (BDNF) were present in the CA1-CA3 hippocampal region of CD mice, which could account for LTP deficits in these mice. Taken together, these results suggest a defect of CA1 synapses in CD mice to sustain synaptic strength after stimulation. These data represent the first description of synaptic functional deficits in CD mice and further highlights the utility of the CD model to study the mechanisms underlying the WBS neurocognitive profile. PMID:27485321

  4. Establishment of Two Mouse Models for CEDNIK Syndrome Reveals the Pivotal Role of SNAP29 in Epidermal Differentiation.

    PubMed

    Schiller, Stina A; Seebode, Christina; Wieser, Georg L; Goebbels, Sandra; Möbius, Wiebke; Horowitz, Mia; Sarig, Ofer; Sprecher, Eli; Emmert, Steffen

    2016-03-01

    Loss-of-function mutations in the synaptosomal-associated protein 29 (SNAP29) gene cause the cerebral dysgenesis, neuropathy, ichthyosis, and keratoderma syndrome. In this study, we created total (Snap29(-/-)) as well as keratinocyte-specific (Snap29(fl/fl)/K14-Cre) Snap29 knockout mice. Both mutant mice exhibited a congenital distinct ichthyotic phenotype resulting in neonatal lethality. Mutant mice revealed acanthosis and hyperkeratosis as well as abnormal keratinocyte differentiation and increased proliferation. In addition, the epidermal barrier was severely impaired. These results indicate an essential role of SNAP29 in epidermal differentiation and barrier formation. Markedly decreased deposition of lamellar body contents in mutant mice epidermis and the observation of malformed lamellar bodies indicate severe impairments in lamellar body function due to the Snap29 knockout. We also found increased microtubule associated protein-1 light chain 3, isoform B-II levels, unchanged p62/SQSTM1 protein amounts, and strong induction of the endoplasmic reticulum stress marker C/EBP homologous protein in mutant mice. This emphasizes a role of SNAP29 in autophagy and endoplasmic reticulum stress. Our murine models serve as powerful tools for investigating keratinocyte differentiation processes and provide insights into the essential contribution of SNAP29 to epidermal differentiation. PMID:26747696

  5. Deficits in hippocampal CA1 LTP induced by TBS but not HFS in the Ts65Dn mouse: a model of Down syndrome.

    PubMed

    Costa, Alberto C S; Grybko, Michael J

    2005-07-15

    Down syndrome (DS) is the most common genetically defined cause of intellectual disabilities. Both hippocampal function and volume seem to be disproportionally reduced in individuals with DS and in at least one aneuploid murine model of DS, the Ts65Dn mouse. Two previous studies by one research group have reported deficits in long-term potentiation (LTP) induced by in vitro high-frequency stimulation (HFS) of hippocampal CA1 synapses of adult Ts65Dn mice. Here, we report on the results of our own investigation on LTP in Ts65Dn mice. This study was designed to confirm the previous findings and possibly shed some light onto potential mechanisms underlying the reported deficit in this important form of long-term synaptic plasticity in a mouse model of DS. LTP was induced in area CA1 with either theta burst stimulation (TBS) or HFS. Contrary to the previous reports, our results showed no significant difference in HFS-induced LTP between Ts65Dn and euploid littermate mice. We have found, however, a significant reduction of the amount of TBS-induced LTP in Ts65Dn mice compared to euploid controls. Because this specific LTP deficit can be rescued by bath application of picrotoxin (10 microM), we hypothesize that an increase in GABA(A)-mediated inhibition or in plasticity of the inhibitory circuitry in Ts65Dn mice may underlie the observed deficits. However, future experiments to examine the state of hippocampus CA1 GABAergic inhibition in Ts65Dn mice will be necessary to further explore these hypotheses. PMID:15925111

  6. Sjögren's syndrome associated dry eye in a mouse model is ameliorated by topical application of integrin α4 antagonist GW559090.

    PubMed

    Contreras-Ruiz, Laura; Mir, Fayaz A; Turpie, Bruce; Krauss, Achim H; Masli, Sharmila

    2016-02-01

    Sjögren's syndrome is an autoimmune disease associated with inflammation of exocrine glands with clinical manifestations of dry eye and dry mouth. Dry eye in this disease involves inflammation of the ocular surface tissues - cornea and conjunctiva. While systemic blockade of adhesion molecules has been used to treat autoimmune diseases, the purpose of this study was to determine the therapeutic efficacy of topical application of an integrin α4 adhesion molecule antagonist in a mouse model of dry eye associated with Sjögren's syndrome. To assess this spontaneously developed ocular surface inflammation related to Sjögren's syndrome in TSP-1null mice (12 wks) was evaluated. Mice were treated with topical formulations containing 0.1% dexamethasone or 30 mg/ml GW559090 or vehicle control. Corneal fluorescein staining and conjunctival goblet cell density were assessed. Real-time PCR analysis was performed to assess expression of the inflammatory marker IL-1β in the cornea and Tbet and RORγt in the draining lymph nodes. Ocular surface inflammation was detectable in TSP-1null mice (≥12 wk old), which resulted in increased corneal fluorescein staining indicative of corneal barrier disruption and reduced conjunctival goblet cell density. These changes were accompanied by increased corneal expression of IL-1β as compared to WT controls and an altered balance of Th1 (Tbet) and Th17 (RORγt) markers in the draining lymph nodes. Topically applied dexamethasone and GW559090 significantly reduced corneal fluorescein staining compared to vehicle treatment (p = 0.023 and p < 0.001, respectively). This improved corneal barrier integrity upon adhesion molecule blockade was consistent with significantly reduced corneal expression of pro-inflammatory IL-1β compared to vehicle treated groups (p < 0.05 for both treatments). Significant improvement in goblet cell density was also noted in mice treated with 0.1% dexamethasone and GW559090 (p < 0.05 for both). We conclude

  7. Impaired hippocampal plasticity and altered neurogenesis in adult Ube3a maternal deficient mouse model for Angelman syndrome.

    PubMed

    Mardirossian, Sandrine; Rampon, Claire; Salvert, Denise; Fort, Patrice; Sarda, Nicole

    2009-12-01

    Angelman syndrome (AS) is a severe neurodevelopmental disorder characterized by mental retardation, seizures and sleep disturbances. It results from lack of the functional maternal allele of UBE3A gene. Ube3a maternal-deficient mice (Ube3a m-/p+), animal models for AS, are impaired in hippocampal-dependent learning tasks as compared with control (Ube3a m+/p+) mice. We first examined the basal expression of immediate early genes which expression is required for synaptic plasticity and memory formation. We found that basal expression of c-fos and Arc genes is reduced in the DG of Ube3a maternal deficient mice compared to their non-transgenic littermates. We then examined whether adult hippocampal neurogenesis, which likely serves as a mechanism toward brain plasticity, is altered in these transgenic mice. Neurogenesis occurs throughout life in mammalian dentate gyrus (DG) and recent findings suggest that newborn granule cells are involved in some forms of learning and memory. Whether maternal Ube3a deletion is detrimental on hippocampal neurogenesis is unclear. Herein, we show, using the mitotic marker Ki67, the birthdating marker 5-bromo-2'-dexoyuridine (BrdU) and the marker doublecortin (DCX) to respectively label cell proliferation, cell survival or young neuron production, that the Ube3a maternal deletion does not affect the proliferation nor the survival of newborn cells in the hippocampus. In contrast, using the postmitotic neuronal marker (NeuN), we show that Ube3a maternal deletion is associated with a lower fraction of BrdU+/NeuN+ newborn neurons among the population of surviving new cells in the hippocampus. Collectively, these findings suggest that some aspects of adult neurogenesis and plasticity are affected by Ube3a deletion and may contribute to the hippocampal dysfunction observed in AS mice. PMID:19782683

  8. The functional nature of synaptic circuitry is altered in area CA3 of the hippocampus in a mouse model of Down's syndrome

    PubMed Central

    Hanson, Jesse E; Blank, Martina; Valenzuela, Ricardo A; Garner, Craig C; Madison, Daniel V

    2007-01-01

    Down's syndrome (DS) is the most common cause of mental retardation, and memory impairments are more severe in DS than in most if not all other causes of mental retardation. The Ts65Dn mouse, a genetic model of DS, exhibits phenotypes of DS, including memory impairments indicative of hippocampal dysfunction. We examined functional synaptic connectivity in area CA3 of the hippocampus of Ts65Dn mice using organotypic slice cultures as a model. We found reductions in multiple measures of synaptic function in both excitatory and inhibitory inputs to pyramidal neurons in CA3 of the Ts65Dn hippocampus. However, associational synaptic connections between pyramidal neurons were more abundant and more likely to be active rather than silent in the Ts65Dn hippocampus. Synaptic potentiation was normal in these associational connections. Decreased overall functional synaptic input onto pyramidal neurons expressed along with the specific hyperconnectivity of associational connections between pyramidal neurons will result in predictable alterations of CA3 network function, which may contribute to the memory impairments seen in DS. PMID:17158177

  9. Weaker control of the electrical properties of cerebellar granule cells by tonically active GABAA receptors in the Ts65Dn mouse model of Down’s syndrome

    PubMed Central

    2013-01-01

    Background Down’s syndrome (DS) is caused by triplication of all or part of human chromosome 21 and is characterized by a decrease in the overall size of the brain. One of the brain regions most affected is the cerebellum, in which the number of granule cells (GCs) is markedly decreased. GCs process sensory information entering the cerebellum via mossy fibres and pass it on to Purkinje cells and inhibitory interneurons. How GCs transform incoming signals depends on their input–output relationship, which is adjusted by tonically active GABAA receptor channels. Results We report that in the Ts65Dn mouse model of DS, in which cerebellar volume and GC number are decreased as in DS, the tonic GABAA receptor current in GCs is smaller than in wild-type mice and is less effective in moderating input resistance and raising the minimum current required for action potential firing. We also find that tonically active GABAA receptors curb the height and broaden the width of action potentials in wild-type GCs but not in Ts65Dn GCs. Single-cell real-time quantitative PCR reveals that these electrical differences are accompanied by decreased expression of the gene encoding the GABAA receptor β3 subunit but not genes coding for some of the other GABAA receptor subunits expressed in GCs (α1, α6, β2 and δ). Conclusions Weaker moderation of excitability and action potential waveform in GCs of the Ts65Dn mouse by tonically active GABAA receptors is likely to contribute to atypical transfer of information through the cerebellum. Similar changes may occur in DS. PMID:23870245

  10. The App-Runx1 Region Is Critical for Birth Defects and Electrocardiographic Dysfunctions Observed in a Down Syndrome Mouse Model

    PubMed Central

    Raveau, Matthieu; Lignon, Jacques M.; Nalesso, Valérie; Duchon, Arnaud; Groner, Yoram; Sharp, Andrew J.; Dembele, Doulaye; Brault, Véronique; Hérault, Yann

    2012-01-01

    Down syndrome (DS) leads to complex phenotypes and is the main genetic cause of birth defects and heart diseases. The Ts65Dn DS mouse model is trisomic for the distal part of mouse chromosome 16 and displays similar features with post-natal lethality and cardiovascular defects. In order to better understand these defects, we defined electrocardiogram (ECG) with a precordial set-up, and we found conduction defects and modifications in wave shape, amplitudes, and durations in Ts65Dn mice. By using a genetic approach consisting of crossing Ts65Dn mice with Ms5Yah mice monosomic for the App-Runx1 genetic interval, we showed that the Ts65Dn viability and ECG were improved by this reduction of gene copy number. Whole-genome expression studies confirmed gene dosage effect in Ts65Dn, Ms5Yah, and Ts65Dn/Ms5Yah hearts and showed an overall perturbation of pathways connected to post-natal lethality (Coq7, Dyrk1a, F5, Gabpa, Hmgn1, Pde10a, Morc3, Slc5a3, and Vwf) and heart function (Tfb1m, Adam19, Slc8a1/Ncx1, and Rcan1). In addition cardiac connexins (Cx40, Cx43) and sodium channel sub-units (Scn5a, Scn1b, Scn10a) were found down-regulated in Ts65Dn atria with additional down-regulation of Cx40 in Ts65Dn ventricles and were likely contributing to conduction defects. All these data pinpoint new cardiac phenotypes in the Ts65Dn, mimicking aspects of human DS features and pathways altered in the mouse model. In addition they highlight the role of the App-Runx1 interval, including Sod1 and Tiam1, in the induction of post-natal lethality and of the cardiac conduction defects in Ts65Dn. These results might lead to new therapeutic strategies to improve the care of DS people. PMID:22693452

  11. Animal Models of Williams Syndrome

    PubMed Central

    OSBORNE, LUCY R.

    2010-01-01

    In recent years, researchers have generated a variety of mouse models in an attempt to dissect the contribution of individual genes to the complex phenotype associated with Williams syndrome (WS). The mouse genome is easily manipulated to produce animals that are copies of humans with genetic conditions, be it with null mutations, hypomorphic mutations, point mutations, or even large deletions encompassing many genes. The existing mouse models certainly seem to implicate hemizygosity for ELN, BAZ1B, CLIP2, and GTF2IRD1 in WS, and new mice with large deletions of the WS region are helping us to understand both the additive and potential combinatorial effects of hemizygosity for specific genes. However, not all genes that are haploinsufficient in humans prove to be so in mice and the effect of genetic background can also have a significant effect on the penetrance of many phenotypes. Thus although mouse models are powerful tools, the information garnered from their study must be carefully interpreted. Nevertheless, mouse models look set to provide a wealth of information about the neuroanatomy, neurophysiology and molecular pathways that underlie WS and in the future will act as essential tools for the development and testing of therapeutics. PMID:20425782

  12. Diminished dosage of 22q11 genes disrupts neurogenesis and cortical development in a mouse model of 22q11 deletion/DiGeorge syndrome

    PubMed Central

    Meechan, Daniel W.; Tucker, Eric S.; Maynard, Thomas M.; LaMantia, Anthony-Samuel

    2009-01-01

    The 22q11 deletion (or DiGeorge) syndrome (22q11DS), the result of a 1.5- to 3-megabase hemizygous deletion on human chromosome 22, results in dramatically increased susceptibility for “diseases of cortical connectivity” thought to arise during development, including schizophrenia and autism. We show that diminished dosage of the genes deleted in the 1.5-megabase 22q11 minimal critical deleted region in a mouse model of 22q11DS specifically compromises neurogenesis and subsequent differentiation in the cerebral cortex. Proliferation of basal, but not apical, progenitors is disrupted, and subsequently, the frequency of layer 2/3, but not layer 5/6, projection neurons is altered. This change is paralleled by aberrant distribution of parvalbumin-labeled interneurons in upper and lower cortical layers. Deletion of Tbx1 or Prodh (22q11 genes independently associated with 22q11DS phenotypes) does not similarly disrupt basal progenitors. However, expression analysis implicates additional 22q11 genes that are selectively expressed in cortical precursors. Thus, diminished 22q11 gene dosage disrupts cortical neurogenesis and interneuron migration. Such developmental disruption may alter cortical circuitry and establish vulnerability for developmental disorders, including schizophrenia and autism. PMID:19805316

  13. Age-Dependent Long-Term Potentiation Deficits in the Prefrontal Cortex of the Fmr1 Knockout Mouse Model of Fragile X Syndrome.

    PubMed

    Martin, Henry G S; Lassalle, Olivier; Brown, Jonathan T; Manzoni, Olivier J

    2016-05-01

    The most common inherited monogenetic cause of intellectual disability is Fragile X syndrome (FXS). The clinical symptoms of FXS evolve with age during adulthood; however, neurophysiological data exploring this phenomenon are limited. TheFmr1knockout (Fmr1KO) mouse models FXS, but studies in these mice of prefrontal cortex (PFC) function are underrepresented, and aging linked data are absent. We studied synaptic physiology and activity-dependent synaptic plasticity in the medial PFC ofFmr1KO mice from 2 to 12 months. In young adultFmr1KO mice, NMDA receptor (NMDAR)-mediated long-term potentiation (LTP) is intact; however, in 12-month-old mice this LTP is impaired. In parallel, there was an increase in the AMPAR/NMDAR ratio and a concomitant decrease of synaptic NMDAR currents in 12-month-oldFmr1KO mice. We found that acute pharmacological blockade of mGlu5receptor in 12-month-oldFmr1KO mice restored a normal AMPAR/NMDAR ratio and LTP. Taken together, the data reveal an age-dependent deficit in LTP inFmr1KO mice, which may correlate to some of the complex age-related deficits in FXS. PMID:25750254

  14. Penetrance of Congenital Heart Disease in a Mouse Model of Down Syndrome Depends on a Trisomic Potentiator of a Disomic Modifier.

    PubMed

    Li, Huiqing; Edie, Sarah; Klinedinst, Donna; Jeong, Jun Seop; Blackshaw, Seth; Maslen, Cheryl L; Reeves, Roger H

    2016-06-01

    Down syndrome (DS) is a significant risk factor for congenital heart disease (CHD), increasing the incidence 50 times over the general population. However, half of people with DS have a normal heart and thus trisomy 21 is not sufficient to cause CHD by itself. Ts65Dn mice are trisomic for orthologs of >100 Hsa21 genes, and their heart defect frequency is significantly higher than their euploid littermates. Introduction of a null allele of Creld1 into Ts65Dn increases the penetrance of heart defects significantly. However, this increase was not seen when the Creld1 null allele was introduced into Ts1Cje, a mouse that is trisomic for about two thirds of the Hsa21 orthologs that are triplicated in Ts65Dn. Among the 23 genes present in three copies in Ts65Dn but not Ts1Cje, we identified Jam2 as necessary for the increased penetrance of Creld1-mediated septal defects in Ts65Dn. Thus, overexpression of the trisomic gene, Jam2, is a necessary potentiator of the disomic genetic modifier, Creld1 No direct physical interaction between Jam2 and Creld1 was identified by several methods. Regions of Hsa21 containing genes that are risk factors of CHD have been identified, but Jam2 (and its environs) has not been linked to heart formation previously. The complexity of this interaction may be more representative of the clinical situation in people than consideration of simple single-gene models. PMID:27029737

  15. Loss and Gain of MeCP2 Cause Similar Hippocampal Circuit Dysfunction that Is Rescued by Deep Brain Stimulation in a Rett Syndrome Mouse Model.

    PubMed

    Lu, Hui; Ash, Ryan T; He, Lingjie; Kee, Sara E; Wang, Wei; Yu, Dinghui; Hao, Shuang; Meng, Xiangling; Ure, Kerstin; Ito-Ishida, Aya; Tang, Bin; Sun, Yaling; Ji, Daoyun; Tang, Jianrong; Arenkiel, Benjamin R; Smirnakis, Stelios M; Zoghbi, Huda Y

    2016-08-17

    Loss- and gain-of-function mutations in methyl-CpG-binding protein 2 (MECP2) underlie two distinct neurological syndromes with strikingly similar features, but the synaptic and circuit-level changes mediating these shared features are undefined. Here we report three novel signs of neural circuit dysfunction in three mouse models of MECP2 disorders (constitutive Mecp2 null, mosaic Mecp2(+/-), and MECP2 duplication): abnormally elevated synchrony in the firing activity of hippocampal CA1 pyramidal neurons, an impaired homeostatic response to perturbations of excitatory-inhibitory balance, and decreased excitatory synaptic response in inhibitory neurons. Conditional mutagenesis studies revealed that MeCP2 dysfunction in excitatory neurons mediated elevated synchrony at baseline, while MeCP2 dysfunction in inhibitory neurons increased susceptibility to hypersynchronization in response to perturbations. Chronic forniceal deep brain stimulation (DBS), recently shown to rescue hippocampus-dependent learning and memory in Mecp2(+/-) (Rett) mice, also rescued all three features of hippocampal circuit dysfunction in these mice. PMID:27499081

  16. Succination is Increased on Select Proteins in the Brainstem of the NADH dehydrogenase (ubiquinone) Fe-S protein 4 (Ndufs4) Knockout Mouse, a Model of Leigh Syndrome.

    PubMed

    Piroli, Gerardo G; Manuel, Allison M; Clapper, Anna C; Walla, Michael D; Baatz, John E; Palmiter, Richard D; Quintana, Albert; Frizzell, Norma

    2016-02-01

    Elevated fumarate concentrations as a result of Krebs cycle inhibition lead to increases in protein succination, an irreversible post-translational modification that occurs when fumarate reacts with cysteine residues to generate S-(2-succino)cysteine (2SC). Metabolic events that reduce NADH re-oxidation can block Krebs cycle activity; therefore we hypothesized that oxidative phosphorylation deficiencies, such as those observed in some mitochondrial diseases, would also lead to increased protein succination. Using the Ndufs4 knockout (Ndufs4 KO) mouse, a model of Leigh syndrome, we demonstrate for the first time that protein succination is increased in the brainstem (BS), particularly in the vestibular nucleus. Importantly, the brainstem is the most affected region exhibiting neurodegeneration and astrocyte and microglial proliferation, and these mice typically die of respiratory failure attributed to vestibular nucleus pathology. In contrast, no increases in protein succination were observed in the skeletal muscle, corresponding with the lack of muscle pathology observed in this model. 2D SDS-PAGE followed by immunoblotting for succinated proteins and MS/MS analysis of BS proteins allowed us to identify the voltage-dependent anion channels 1 and 2 as specific targets of succination in the Ndufs4 knockout. Using targeted mass spectrometry, Cys(77) and Cys(48) were identified as endogenous sites of succination in voltage-dependent anion channels 2. Given the important role of voltage-dependent anion channels isoforms in the exchange of ADP/ATP between the cytosol and the mitochondria, and the already decreased capacity for ATP synthesis in the Ndufs4 KO mice, we propose that the increased protein succination observed in the BS of these animals would further decrease the already compromised mitochondrial function. These data suggest that fumarate is a novel biochemical link that may contribute to the progression of the neuropathology in this mitochondrial disease

  17. Regional changes in elastic fiber organization and transforming growth factor β signaling in aortas from a mouse model of marfan syndrome.

    PubMed

    Howell, David W; Popovic, Natasa; Metz, Richard P; Wilson, Emily

    2014-12-01

    In Marfan Syndrome (MFS), development of thoracic aortic aneurysms (TAAs) is characterized by degeneration of the medial layer of the aorta, including fragmentation and loss of elastic fibers, phenotypic changes in the smooth muscle cells, and an increase in the active form of transforming growth factor-β (TGFβ), which is thought to play a major role in development and progression of the aneurysm. We hypothesized that regional difference in elastic fiber fragmentation contributes to TGFβ activation and hence the localization of aneurysm formation. The fibrillin-1-deficient mgR/mgR mouse model of MFS was used to investigate regional changes in elastin fiber fragmentation, TGFβ activation and changes in gene expression as compared to wild-type littermates. Knockdown of Smad 2 and Smad 3 with shRNA was used to determine the role of the specific transcription factors in gene regulation in aortic smooth muscle cells. We show increased elastin fiber fragmentation in the regions associated with aneurysm formation and altered TGFβ signaling in these regions. Differential effects of Smad 2 and Smad 3 were observed in cultured smooth muscle cells by shRNA-mediated knockdown of expression of these transcription factors. Differential signaling through Smad 2 and Smad 3 in regions of active vascular remodeling likely contribute to aneurysm formation in the mgR/mgR model of MFS. Increased elastin fiber fragmentation in these regions is associated with these changes as compared to other regions of the thoracic aorta and may contribute to the changes in TGFβ signaling in these regions. PMID:25238995

  18. Changes in Sensitivity of Reward and Motor Behavior to Dopaminergic, Glutamatergic, and Cholinergic Drugs in a Mouse Model of Fragile X Syndrome

    PubMed Central

    Fish, Eric W.; Krouse, Michael C.; Stringfield, Sierra J.; DiBerto, Jeffrey F.; Robinson, J. Elliott; Malanga, C. J.

    2013-01-01

    Fragile X syndrome (FXS) is a leading cause of intellectual disability. FXS is caused by loss of function of the FMR1 gene, and mice in which Fmr1 has been inactivated have been used extensively as a preclinical model for FXS. We investigated the behavioral pharmacology of drugs acting through dopaminergic, glutamatergic, and cholinergic systems in fragile X (Fmr1-/Y) mice with intracranial self-stimulation (ICSS) and locomotor activity measurements. We also measured brain expression of tyrosine hydroxylase (TH), the rate-limiting enzyme in dopamine biosynthesis. Fmr1-/Y mice were more sensitive than wild type mice to the rewarding effects of cocaine, but less sensitive to its locomotor stimulating effects. Anhedonic but not motor depressant effects of the atypical neuroleptic, aripiprazole, were reduced in Fmr1-/Y mice. The mGluR5-selective antagonist, 6-methyl-2-(phenylethynyl)pyridine (MPEP), was more rewarding and the preferential M1 antagonist, trihexyphenidyl, was less rewarding in Fmr1-/Y than wild type mice. Motor stimulation by MPEP was unchanged, but stimulation by trihexyphenidyl was markedly increased, in Fmr1-/Y mice. Numbers of midbrain TH+ neurons in the ventral tegmental area were unchanged, but were lower in the substantia nigra of Fmr1-/Y mice, although no changes in TH levels were found in their forebrain targets. The data are discussed in the context of known changes in the synaptic physiology and pharmacology of limbic motor systems in the Fmr1-/Y mouse model. Preclinical findings suggest that drugs acting through multiple neurotransmitter systems may be necessary to fully address abnormal behaviors in individuals with FXS. PMID:24205018

  19. A mouse model of Townes-Brocks syndrome expressing a truncated mutant Sall1 protein is protected from acute kidney injury.

    PubMed

    Hirsch, Sara; El-Achkar, Tarek; Robbins, Lynn; Basta, Jeannine; Heitmeier, Monique; Nishinakamura, Ryuichi; Rauchman, Michael

    2015-11-15

    It has been postulated that developmental pathways are reutilized during repair and regeneration after injury, but functional analysis of many genes required for kidney formation has not been performed in the adult organ. Mutations in SALL1 cause Townes-Brocks syndrome (TBS) and nonsyndromic congenital anomalies of the kidney and urinary tract, both of which lead to childhood kidney failure. Sall1 is a transcriptional regulator that is expressed in renal progenitor cells and developing nephrons in the embryo. However, its role in the adult kidney has not been investigated. Using a mouse model of TBS (Sall1TBS), we investigated the role of Sall1 in response to acute kidney injury. Our studies revealed that Sall1 is expressed in terminally differentiated renal epithelia, including the S3 segment of the proximal tubule, in the mature kidney. Sall1TBS mice exhibited significant protection from ischemia-reperfusion injury and aristolochic acid-induced nephrotoxicity. This protection from acute injury is seen despite the presence of slowly progressive chronic kidney disease in Sall1TBS mice. Mice containing null alleles of Sall1 are not protected from acute kidney injury, indicating that expression of a truncated mutant protein from the Sall1TBS allele, while causative of congenital anomalies, protects the adult kidney from injury. Our studies further revealed that basal levels of the preconditioning factor heme oxygenase-1 are elevated in Sall1TBS kidneys, suggesting a mechanism for the relative resistance to injury in this model. Together, these studies establish a functional role for Sall1 in the response of the adult kidney to acute injury. PMID:26311113

  20. Swift Intrahepatic Accumulation of Granulocytic Myeloid-Derived Suppressor Cells in a Humanized Mouse Model of Toxic Shock Syndrome.

    PubMed

    Szabo, Peter A; Goswami, Ankur; Memarnejadian, Arash; Mallett, Christiane L; Foster, Paula J; McCormick, John K; Haeryfar, S M Mansour

    2016-06-15

    Toxic shock syndrome (TSS) and other superantigen-mediated illnesses are associated with 'systemic' immunosuppression that jeopardizes the host's ability to fight pathogens. Here, we define a novel mechanism of 'local' immunosuppression that may benefit the host. Systemic exposure to staphylococcal enterotoxin B (SEB) rapidly and selectively recruited CD11b(+)Gr-1(high)Ly-6C(+) granulocytic myeloid-derived suppressor cells (MDSCs) to the liver of HLA-DR4 transgenic mice. Hepatic MDSCs inhibited SEB-triggered T cell proliferation in a reactive oxygen species-dependent manner, and ex vivo-generated human MDSCs also similarly attenuated the proliferative response of autologous T cells to SEB. We propose a role for MDSCs in mitigating excessive tissue injury during TSS. PMID:26908735

  1. Preclinical mouse models of osteosarcoma.

    PubMed

    Uluçkan, Özge; Segaliny, Aude; Botter, Sander; Santiago, Janice M; Mutsaers, Anthony J

    2015-01-01

    Osteosarcoma is the most common form of primary bone tumors with high prevalence in children. Survival rates of osteosarcoma are low, especially in the case of metastases. Mouse models of this disease have been very valuable in investigation of mechanisms of tumorigenesis, metastasis, as well as testing possible therapeutic options. In this chapter, we summarize currently available mouse models for osteosarcoma and provide detailed methodology for the isolation of cell lines from genetically engineered mouse models (GEMMs), gene modification and tumor cell injection methods, as well as imaging techniques. PMID:25987985

  2. A selective 5-HT1a receptor agonist improves respiration in a mouse model of Rett syndrome

    PubMed Central

    Levitt, Erica S.; Hunnicutt, Barbara J.; Knopp, Sharon J.; Williams, John T.

    2013-01-01

    Rett syndrome is a neurological disorder caused by loss of function mutations in the gene that encodes the DNA binding protein methyl-CpG-binding protein 2 (Mecp2). A prominent feature of the syndrome is disturbances in respiration characterized by frequent apnea and an irregular interbreath cycle. 8-Hydroxy-2-dipropylaminotetralin has been shown to positively modulate these disturbances (Abdala AP, Dutschmann M, Bissonnette JM, Paton JF, Proc Natl Acad Sci U S A 107: 18208–18213, 2010), but the mode of action is not understood. Here we show that the selective 5-HT1a biased agonist 3-chloro-4-fluorophenyl-(4-fluoro-4-{[(5-methylpyrimidin-2-ylmethyl)-amino]-methyl}-piperidin-1-yl)-methanone (F15599) decreases apnea and corrects irregularity in both heterozygous Mecp2-deficient female and in Mecp2 null male mice. In whole cell voltage-clamp recordings from dorsal raphe neurons, F15599 potently induced an outward current, which was blocked by barium, reversed at the potassium equilibrium potential, and was antagonized by the 5-HT1a antagonist WAY100135. This is consistent with somatodendritic 5-HT1a receptor-mediated activation of G protein-coupled inwardly rectifying potassium channels (GIRK). In contrast, F15599 did not activate 5-HT1b/d receptors that mediate inhibition of glutamate release from terminals in the nucleus accumbens by a presynaptic mechanism. Thus F15599 activated somatodendritic 5-HT1a autoreceptors, but not axonal 5-HT1b/d receptors. In unanesthetized Mecp2-deficient heterozygous female mice, F15599 reduced apnea in a dose-dependent manner with maximal effect of 74.5 ± 6.9% at 0.1 mg/kg and improved breath irrregularity. Similarly, in Mecp2 null male mice, apnea was reduced by 62 ± 6.6% at 0.25 mg/kg, and breathing became regular. The results indicate respiration is improved with a 5-HT1a agonist that activates GIRK channels without affecting neurotransmitter release. PMID:24092697

  3. Self-Organizing Feature Maps Identify Proteins Critical to Learning in a Mouse Model of Down Syndrome

    PubMed Central

    Higuera, Clara; Gardiner, Katheleen J.; Cios, Krzysztof J.

    2015-01-01

    Down syndrome (DS) is a chromosomal abnormality (trisomy of human chromosome 21) associated with intellectual disability and affecting approximately one in 1000 live births worldwide. The overexpression of genes encoded by the extra copy of a normal chromosome in DS is believed to be sufficient to perturb normal pathways and normal responses to stimulation, causing learning and memory deficits. In this work, we have designed a strategy based on the unsupervised clustering method, Self Organizing Maps (SOM), to identify biologically important differences in protein levels in mice exposed to context fear conditioning (CFC). We analyzed expression levels of 77 proteins obtained from normal genotype control mice and from their trisomic littermates (Ts65Dn) both with and without treatment with the drug memantine. Control mice learn successfully while the trisomic mice fail, unless they are first treated with the drug, which rescues their learning ability. The SOM approach identified reduced subsets of proteins predicted to make the most critical contributions to normal learning, to failed learning and rescued learning, and provides a visual representation of the data that allows the user to extract patterns that may underlie novel biological responses to the different kinds of learning and the response to memantine. Results suggest that the application of SOM to new experimental data sets of complex protein profiles can be used to identify common critical protein responses, which in turn may aid in identifying potentially more effective drug targets. PMID:26111164

  4. Self-Organizing Feature Maps Identify Proteins Critical to Learning in a Mouse Model of Down Syndrome.

    PubMed

    Higuera, Clara; Gardiner, Katheleen J; Cios, Krzysztof J

    2015-01-01

    Down syndrome (DS) is a chromosomal abnormality (trisomy of human chromosome 21) associated with intellectual disability and affecting approximately one in 1000 live births worldwide. The overexpression of genes encoded by the extra copy of a normal chromosome in DS is believed to be sufficient to perturb normal pathways and normal responses to stimulation, causing learning and memory deficits. In this work, we have designed a strategy based on the unsupervised clustering method, Self Organizing Maps (SOM), to identify biologically important differences in protein levels in mice exposed to context fear conditioning (CFC). We analyzed expression levels of 77 proteins obtained from normal genotype control mice and from their trisomic littermates (Ts65Dn) both with and without treatment with the drug memantine. Control mice learn successfully while the trisomic mice fail, unless they are first treated with the drug, which rescues their learning ability. The SOM approach identified reduced subsets of proteins predicted to make the most critical contributions to normal learning, to failed learning and rescued learning, and provides a visual representation of the data that allows the user to extract patterns that may underlie novel biological responses to the different kinds of learning and the response to memantine. Results suggest that the application of SOM to new experimental data sets of complex protein profiles can be used to identify common critical protein responses, which in turn may aid in identifying potentially more effective drug targets. PMID:26111164

  5. Par2 inactivation inhibits early production of TSLP, but not cutaneous inflammation, in Netherton syndrome adult mouse model.

    PubMed

    Briot, Anaïs; Lacroix, Matthieu; Robin, Aurélie; Steinhoff, Martin; Deraison, Céline; Hovnanian, Alain

    2010-12-01

    Netherton syndrome (NS) is a severe genodermatosis characterized by abnormal scaling and constant atopic manifestations. NS is caused by mutations in SPINK5 (Serine Protease INhibitor Kazal-type 5), which encodes LEKTI (LymphoEpithelial Kazal Type-related Inhibitor). Lack of LEKTI causes stratum corneum detachment secondary to epidermal proteases hyperactivity. Whereas a skin barrier defect is generally regarded as a major cause for atopy, we previously identified a cell-autonomous signaling cascade that triggers pro-Th2 cytokine thymic stromal lymphopoietin (TSLP) production in LEKTI-deficient epidermis. This signaling is initiated by unrestricted kallikrein 5 (KLK5) activity, which directly activates proteinase-activated receptor 2 (PAR2)-mediated expression of TSLP and favors a cutaneous proallergic microenvironment independently of the environment and of the adaptive immune system. To further confirm these results in vivo, we generated Spink5/Par2 double knockout (DKO) mice. At embryonic day 19.5, these mice display a dramatic decrease in TSLP expression, although stratum corneum detachment persists, confirming the role of the KLK5-PAR2 cascade in TSLP-mediated early proallergic signaling. However, deletion of Par2 in adult DKO-grafted skin does not rescue the inflammatory phenotype probably resulting from stratum corneum detachment. We conclude that several mechanisms trigger and maintain the inflammatory phenotype in NS. These include skin barrier impairment, mechanical stress secondary to stratum corneum detachment, as well as protease-induced proinflammatory and proallergic pathways, including PAR2-mediated overexpression of TSLP. PMID:20703245

  6. MeCP2 SUMOylation rescues Mecp2-mutant-induced behavioural deficits in a mouse model of Rett syndrome

    PubMed Central

    Tai, Derek J. C.; Liu, Yen C.; Hsu, Wei L.; Ma, Yun L.; Cheng, Sin J.; Liu, Shau Y.; Lee, Eminy H. Y.

    2016-01-01

    The methyl-CpG-binding protein 2 (MeCP2) gene, MECP2, is an X-linked gene encoding the MeCP2 protein, and mutations of MECP2 cause Rett syndrome (RTT). However, the molecular mechanism of MECP2-mutation-caused RTT is less known. Here we find that MeCP2 could be SUMO-modified by the E3 ligase PIAS1 at Lys-412. MeCP2 phosphorylation (at Ser-421 and Thr-308) facilitates MeCP2 SUMOylation, and MeCP2 SUMOylation is induced by NMDA, IGF-1 and CRF in the rat brain. MeCP2 SUMOylation releases CREB from the repressor complex and enhances Bdnf mRNA expression. Several MECP2 mutations identified in RTT patients show decreased MeCP2 SUMOylation. Re-expression of wild-type MeCP2 or SUMO-modified MeCP2 in Mecp2-null neurons rescues the deficits of social interaction, fear memory and LTP observed in Mecp2 conditional knockout (cKO) mice. These results together reveal an important role of MeCP2 SUMOylation in social interaction, memory and synaptic plasticity, and that abnormal MeCP2 SUMOylation is implicated in RTT. PMID:26842955

  7. Multiple Organ System Defects and Transcriptional Dysregulation in the Nipbl+/− Mouse, a Model of Cornelia de Lange Syndrome

    PubMed Central

    Santos, Rosaysela; Lopez-Burks, Martha E.; Young, Clint M.; Hoang, Michelle P.; Chua, Abigail; Lao, Taotao; Lechner, Mark S.; Daniel, Jeremy A.; Nussenzweig, Andre; Kitzes, Leonard; Yokomori, Kyoko; Hallgrimsson, Benedikt; Lander, Arthur D.

    2009-01-01

    Cornelia de Lange Syndrome (CdLS) is a multi-organ system birth defects disorder linked, in at least half of cases, to heterozygous mutations in the NIPBL gene. In animals and fungi, orthologs of NIPBL regulate cohesin, a complex of proteins that is essential for chromosome cohesion and is also implicated in DNA repair and transcriptional regulation. Mice heterozygous for a gene-trap mutation in Nipbl were produced and exhibited defects characteristic of CdLS, including small size, craniofacial anomalies, microbrachycephaly, heart defects, hearing abnormalities, delayed bone maturation, reduced body fat, behavioral disturbances, and high mortality (75–80%) during the first weeks of life. These phenotypes arose despite a decrease in Nipbl transcript levels of only ∼30%, implying extreme sensitivity of development to small changes in Nipbl activity. Gene expression profiling demonstrated that Nipbl deficiency leads to modest but significant transcriptional dysregulation of many genes. Expression changes at the protocadherin beta (Pcdhb) locus, as well as at other loci, support the view that NIPBL influences long-range chromosomal regulatory interactions. In addition, evidence is presented that reduced expression of genes involved in adipogenic differentiation may underlie the low amounts of body fat observed both in Nipbl+/− mice and in individuals with CdLS. PMID:19763162

  8. Elevated CaMKIIα and Hyperphosphorylation of Homer Mediate Circuit Dysfunction in a Fragile X Syndrome Mouse Model.

    PubMed

    Guo, Weirui; Ceolin, Laura; Collins, Katie A; Perroy, Julie; Huber, Kimberly M

    2015-12-15

    Abnormal metabotropic glutamate receptor 5 (mGluR5) function, as a result of disrupted scaffolding with its binding partner Homer, contributes to the pathophysiology of fragile X syndrome, a common inherited form of intellectual disability and autism caused by mutations in Fmr1. How loss of Fmr1 disrupts mGluR5-Homer scaffolds is unknown, and little is known about the dynamic regulation of mGluR5-Homer scaffolds in wild-type neurons. Here, we demonstrate that brief (minutes-long) elevations in neural activity cause CaMKIIα-mediated phosphorylation of long Homer proteins and dissociation from mGluR5 at synapses. In Fmr1 knockout (KO) cortex, Homers are hyperphosphorylated as a result of elevated CaMKIIα protein. Genetic or pharmacological inhibition of CaMKIIα or replacement of Homers with dephosphomimetics restores mGluR5-Homer scaffolds and multiple Fmr1 KO phenotypes, including circuit hyperexcitability and/or seizures. This work links translational control of an FMRP target mRNA, CaMKIIα, to the molecular-, cellular-, and circuit-level brain dysfunction in a complex neurodevelopmental disorder. PMID:26670047

  9. MeCP2 SUMOylation rescues Mecp2-mutant-induced behavioural deficits in a mouse model of Rett syndrome.

    PubMed

    Tai, Derek J C; Liu, Yen C; Hsu, Wei L; Ma, Yun L; Cheng, Sin J; Liu, Shau Y; Lee, Eminy H Y

    2016-01-01

    The methyl-CpG-binding protein 2 (MeCP2) gene, MECP2, is an X-linked gene encoding the MeCP2 protein, and mutations of MECP2 cause Rett syndrome (RTT). However, the molecular mechanism of MECP2-mutation-caused RTT is less known. Here we find that MeCP2 could be SUMO-modified by the E3 ligase PIAS1 at Lys-412. MeCP2 phosphorylation (at Ser-421 and Thr-308) facilitates MeCP2 SUMOylation, and MeCP2 SUMOylation is induced by NMDA, IGF-1 and CRF in the rat brain. MeCP2 SUMOylation releases CREB from the repressor complex and enhances Bdnf mRNA expression. Several MECP2 mutations identified in RTT patients show decreased MeCP2 SUMOylation. Re-expression of wild-type MeCP2 or SUMO-modified MeCP2 in Mecp2-null neurons rescues the deficits of social interaction, fear memory and LTP observed in Mecp2 conditional knockout (cKO) mice. These results together reveal an important role of MeCP2 SUMOylation in social interaction, memory and synaptic plasticity, and that abnormal MeCP2 SUMOylation is implicated in RTT. PMID:26842955

  10. Multiple organ system defects and transcriptional dysregulation in the Nipbl(+/-) mouse, a model of Cornelia de Lange Syndrome.

    PubMed

    Kawauchi, Shimako; Calof, Anne L; Santos, Rosaysela; Lopez-Burks, Martha E; Young, Clint M; Hoang, Michelle P; Chua, Abigail; Lao, Taotao; Lechner, Mark S; Daniel, Jeremy A; Nussenzweig, Andre; Kitzes, Leonard; Yokomori, Kyoko; Hallgrimsson, Benedikt; Lander, Arthur D

    2009-09-01

    Cornelia de Lange Syndrome (CdLS) is a multi-organ system birth defects disorder linked, in at least half of cases, to heterozygous mutations in the NIPBL gene. In animals and fungi, orthologs of NIPBL regulate cohesin, a complex of proteins that is essential for chromosome cohesion and is also implicated in DNA repair and transcriptional regulation. Mice heterozygous for a gene-trap mutation in Nipbl were produced and exhibited defects characteristic of CdLS, including small size, craniofacial anomalies, microbrachycephaly, heart defects, hearing abnormalities, delayed bone maturation, reduced body fat, behavioral disturbances, and high mortality (75-80%) during the first weeks of life. These phenotypes arose despite a decrease in Nipbl transcript levels of only approximately 30%, implying extreme sensitivity of development to small changes in Nipbl activity. Gene expression profiling demonstrated that Nipbl deficiency leads to modest but significant transcriptional dysregulation of many genes. Expression changes at the protocadherin beta (Pcdhb) locus, as well as at other loci, support the view that NIPBL influences long-range chromosomal regulatory interactions. In addition, evidence is presented that reduced expression of genes involved in adipogenic differentiation may underlie the low amounts of body fat observed both in Nipbl+/- mice and in individuals with CdLS. PMID:19763162

  11. Tissue-specific Variation of Ube3a Protein Expression in Rodents and in a Mouse Model of Angelman Syndrome

    PubMed Central

    Gustin, Richard M.; Bichell, Terry Jo; Bubser, Michael; Daily, Jennifer; Filonova, Irina; Mrelashvili, Davit; Deutch, Ariel Y.; Colbran, Roger J.; Weeber, Edwin J.; Haas, Kevin F.

    2010-01-01

    Angelman syndrome (AS) is a neurogenetic disorder caused by loss of maternal UBE3A expression or mutation-induced dysfunction of its protein product, the E3 ubiquitin-protein ligase, UBE3A. In humans and rodents, UBE3A/Ube3a transcript is maternally imprinted in several brain regions, but the distribution of native UBE3A/Ube3a1 protein expression has not been comprehensively examined. To address this, we systematically evaluated Ube3a expression in the brain and peripheral tissues of wild-type (WT) and Ube3a maternal knockout mice (AS mice). Immunoblot and immunohistochemical analyses revealed a marked loss of Ube3a protein in hippocampus, hypothalamus, olfactory bulb, cerebral cortex, striatum, thalamus, midbrain, and cerebellum in AS mice relative to WT littermates. Also, Ube3a expression in heart and liver of AS mice showed greater than the predicted 50% reduction relative to WT mice. Co-localization studies showed Ube3a expression to be primarily neuronal in all brain regions and present in GABAergic interneurons as well as principal neurons. These findings suggest that neuronal function throughout the brain is compromised in AS. PMID:20423730

  12. Administration of a DPP-IV Inhibitor Enhances the Intestinal Adaptation in a Mouse Model of Short Bowel Syndrome

    PubMed Central

    Okawada, Manabu; Holst, Jens J.; Teitelbaum, Daniel H.

    2011-01-01

    Background Glucagon-like peptide-2(GLP-2) induces small intestine mucosal epithelial cell (EC) proliferation; and may have benefit for patients suffering from short bowel syndrome (SBS). However, GLP-2 is rapidly inactivated in vivo by dipeptidyl peptidase IV (DPPIV). Therefore, we hypothesized that selectively inhibiting DPPIV would prolong the circulating life of GLP-2 and lead to increased intestinal adaptation after development of SBS. Methods 8-week old C57BL/6J mice underwent a 50% proximal small bowel resection and were treated with either sitagliptin, a DPPIV-inhibitor (DPPIV-I), starting 1 day before surgery versus placebo. DPPIV-I efficacy was assessed 3 days after resection, including intestinal morphology, EC apoptosis and EC proliferation. Adaptive mechanisms were assessed with quantitative real-time PCR, and plasma bioactive GLP-2 was measured by radioimmunoassay. RESULT Body weight loss and peripheral blood glucose levels did not change compared to SBS controls. DPPIV-I treatment led to significant increases in villus height and crypt depth. DPPIV-I treatment did not significantly change EC apoptosis rates, but significantly increased crypt EC proliferation versus placebo-SBS controls. DPPIV-I treatment markedly increased mRNA expression of β-catenin and c-myc in ileal mucosa. Plasma GLP-2 levels significantly increased(~40.9%) in DPPIV-I-SBS mice. Conclusions DPPIV- I treatment increased SBS adaptation, and may potentially be useful for SBS patients. PMID:21719060

  13. MeCP2-mediated alterations of striatal features accompany psychomotor deficits in a mouse model of Rett syndrome.

    PubMed

    Kao, Fang-Chi; Su, San-Hua; Carlson, Gregory C; Liao, Wenlin

    2015-01-01

    Rett Syndrome (RTT) is a neurodevelopmental disorder caused by mutations in the methyl-CpG-binding protein 2 (MECP2) gene. Affected individuals develop motor deficits including stereotypic hand movements, impaired motor learning and difficulties with movement. To understand the neural mechanisms of motor deficits in RTT, we characterized the molecular and cellular phenotypes in the striatum, the major input nucleus of the basal ganglia that controls psychomotor function, in mice carrying a null allele of Mecp2. These mice showed significant hypoactivity associated with impaired motor coordination and motor skill learning. We found that dopamine content was significantly reduced in the striatum of Mecp2 null mice. Reduced dopamine was accompanied by down-regulation of tyrosine hydroxylase and up-regulation of dopamine D2 receptors, particularly in the rostral striatum. We also observed that loss of MeCP2 induced compartment-specific alterations in the striatum, including reduced expression of μ-opioid receptors in the striosomes and increased number of calbindin-positive neurons in the striatal matrix. The total number of parvalbumin-positive interneurons and their dendritic arborization were also significantly increased in the striatum of Mecp2 null mice. Together, our findings support that MeCP2 regulates a unique set of genes critical for modulating motor output of the striatum, and that aberrant structure and function of the striatum due to MeCP2 deficiency may underlie the motor deficits in RTT. PMID:24218106

  14. Treatment of cardiac arrhythmias in a mouse model of Rett syndrome with Na+-channel-blocking antiepileptic drugs.

    PubMed

    Herrera, José A; Ward, Christopher S; Pitcher, Meagan R; Percy, Alan K; Skinner, Steven; Kaufmann, Walter E; Glaze, Daniel G; Wehrens, Xander H T; Neul, Jeffrey L

    2015-04-01

    One quarter of deaths associated with Rett syndrome (RTT), an X-linked neurodevelopmental disorder, are sudden and unexpected. RTT is associated with prolonged QTc interval (LQT), and LQT-associated cardiac arrhythmias are a potential cause of unexpected death. The standard of care for LQT in RTT is treatment with β-adrenergic antagonists; however, recent work indicates that acute treatment of mice with RTT with a β-antagonist, propranolol, does not prevent lethal arrhythmias. In contrast, acute treatment with the Na(+) channel blocker phenytoin prevented arrhythmias. Chronic dosing of propranolol may be required for efficacy; therefore, we tested the efficacy of chronic treatment with either propranolol or phenytoin on RTT mice. Phenytoin completely abolished arrhythmias, whereas propranolol showed no benefit. Surprisingly, phenytoin also normalized weight and activity, but worsened breathing patterns. To explore the role of Na(+) channel blockers on QT in people with RTT, we performed a retrospective analysis of QT status before and after Na(+) channel blocker antiepileptic therapies. Individuals with RTT and LQT significantly improved their QT interval status after being started on Na(+) channel blocker antiepileptic therapies. Thus, Na(+) channel blockers should be considered for the clinical management of LQT in individuals with RTT. PMID:25713300

  15. Inhibition of APP gamma-secretase restores Sonic Hedgehog signaling and neurogenesis in the Ts65Dn mouse model of Down syndrome

    PubMed Central

    Giacomini, Andrea; Stagni, Fiorenza; Trazzi, Stefania; Guidi, Sandra; Emili, Marco; Brigham, Elizabeth; Ciani, Elisabetta; Bartesaghi, Renata

    2015-01-01

    Neurogenesis impairment starting from early developmental stages is a key determinant of intellectual disability in Down syndrome (DS). Previous evidence provided a causal relationship between neurogenesis impairment and malfunctioning of the mitogenic Sonic Hedgehog (Shh) pathway. In particular, excessive levels of AICD (amyloid precursor protein intracellular domain), a cleavage product of the trisomic gene APP (amyloid precursor protein) up-regulate transcription of Ptch1 (Patched1), the Shh receptor that keeps the pathway repressed. Since AICD results from APP cleavage by γ-secretase, the goal of the current study was to establish whether treatment with a γ-secretase inhibitor normalizes AICD levels and restores neurogenesis in trisomic neural precursor cells. We found that treatment with a selective γ-secretase inhibitor (ELND006; ELN) restores proliferation in neurospheres derived from the subventricular zone (SVZ) of the Ts65Dn mouse model of DS. This effect was accompanied by reduction of AICD and Ptch1 levels and was prevented by inhibition of the Shh pathway with cyclopamine. Treatment of Ts65Dn mice with ELN in the postnatal period P3–P15 restored neurogenesis in the SVZ and hippocampus, hippocampal granule cell number and synapse development, indicating a positive impact of treatment on brain development. In addition, in the hippocampus of treated Ts65Dn mice there was a reduction in the expression levels of various genes that are transcriptionally regulated by AICD, including APP, its origin substrate. Inhibitors of γ-secretase are currently envisaged as tools for the cure of Alzheimer's disease because they lower βamyloid levels. Current results provide novel evidence that γ-secretase inhibitors may represent a strategy for the rescue of neurogenesis defects in DS. PMID:26254735

  16. Comparative proteomic profiling reveals aberrant cell proliferation in the brain of embryonic Ts1Cje, a mouse model of Down syndrome.

    PubMed

    Ishihara, K; Kanai, S; Sago, H; Yamakawa, K; Akiba, S

    2014-12-01

    To identify molecular candidates involved in brain disabilities of Ts1Cje, a mouse model of Down syndrome (DS), we performed comparative proteomic analyses. Proteins extracted from the brains of postnatal wild-type (WT) and Ts1Cje mice were analyzed by two-dimensional gel electrophoresis (2-DE). No differences were detected in the proteins expressed in the whole brain between WT and Ts1Cje mice at postnatal day 0 and 3months of age. Five spots with differential expression in the brains of Ts1Cje mice were detected by 2-DE of brain proteins from WT and Ts1Cje embryos at embryonic day 14.5 (E14.5). These differentially expressed proteins in Ts1Cje embryos were identified as calcyclin-binding protein (CACYBP), nucleoside diphosphate kinase-B (NDPK-B), transketolase (TK), pyruvate kinase (PK), and 60S acidic ribosomal protein P0 (RPLP0) by peptide mass fingerprinting. CACYBP and NDPK-B were involved in cell proliferation, whereas TK and PK were associated with energy metabolism. Experiments on cell proliferation, an in vivo bromodeoxyuridine (BrdU)-labeling experiment, and immunohistochemical analysis for phospho-histone H3 (an M-phase marker) demonstrated increased numbers of BrdU-positive and M-phase cells in the ganglionic eminence. Our findings suggest that the dysregulated expression of proteins demonstrated by comparative proteomic analysis could be a factor in increased cell proliferation, which may be associated with abnormalities in DS brain during embryonic life. PMID:25261685

  17. The amyloid precursor protein (APP) triplicated gene impairs neuronal precursor differentiation and neurite development through two different domains in the Ts65Dn mouse model for Down syndrome.

    PubMed

    Trazzi, Stefania; Fuchs, Claudia; Valli, Emanuele; Perini, Giovanni; Bartesaghi, Renata; Ciani, Elisabetta

    2013-07-19

    Intellectual disability in Down syndrome (DS) appears to be related to severe proliferation impairment during brain development. Recent evidence shows that it is not only cellular proliferation that is heavily compromised in DS, but also cell fate specification and dendritic maturation. The amyloid precursor protein (APP), a gene that is triplicated in DS, plays a key role in normal brain development by influencing neural precursor cell proliferation, cell fate specification, and neuronal maturation. APP influences these processes via two separate domains, the APP intracellular domain (AICD) and the soluble secreted APP. We recently found that the proliferation impairment of neuronal precursors (NPCs) from the Ts65Dn mouse model for DS was caused by derangement of the Shh pathway due to overexpression of patched1(Ptch1), its inhibitory regulator. Ptch1 overexpression was related to increased levels within the APP/AICD system. The overall goal of this study was to determine whether APP contributes to neurogenesis impairment in DS by influencing in addition to proliferation, cell fate specification, and neurite development. We found that normalization of APP expression restored the reduced neuronogenesis, the increased astrogliogenesis, and the reduced neurite length of trisomic NPCs, indicating that APP overexpression underpins all aspects of neurogenesis impairment. Moreover, we found that two different domains of APP impair neuronal differentiation and maturation in trisomic NPCs. The APP/AICD system regulates neuronogenesis and neurite length through the Shh pathway, whereas the APP/secreted AP system promotes astrogliogenesis through an IL-6-associated signaling cascade. These results provide novel insight into the mechanisms underlying brain development alterations in DS. PMID:23740250

  18. Short- and long-term effects of neonatal pharmacotherapy with epigallocatechin-3-gallate on hippocampal development in the Ts65Dn mouse model of Down syndrome.

    PubMed

    Stagni, Fiorenza; Giacomini, Andrea; Emili, Marco; Trazzi, Stefania; Guidi, Sandra; Sassi, Martina; Ciani, Elisabetta; Rimondini, Roberto; Bartesaghi, Renata

    2016-10-01

    Cognitive disability is an unavoidable feature of Down syndrome (DS), a genetic disorder due to the triplication of human chromosome 21. DS is associated with alterations of neurogenesis, neuron maturation and connectivity that are already present at prenatal life stages. Recent evidence shows that pharmacotherapies can have a large impact on the trisomic brain provided that they are administered perinatally. Epigallocatechin-3-gallate (EGCG), the major polyphenol of green tea, performs many actions in the brain, including inhibition of DYRK1A, a kinase that is over-expressed in the DS brain and contributes to the DS phenotype. Young adults with DS treated with EGCG exhibit some cognitive benefits, although these effects disappear with time. We deemed it extremely important, however, to establish whether treatment with EGCG at the initial stages of brain development leads to plastic changes that outlast treatment cessation. In the current study, we exploited the Ts65Dn mouse model of DS in order to establish whether pharmacotherapy with EGCG during peak of neurogenesis in the hippocampal dentate gyrus (DG) enduringly restores hippocampal development and memory performance. Euploid and Ts65Dn mice were treated with EGCG from postnatal day 3 (P3) to P15. The effects of treatment were examined at its cessation (at P15) or after one month (at P45). We found that at P15 treated trisomic pups exhibited restoration of neurogenesis, total hippocampal granule cell number and levels of pre- and postsynaptic proteins in the DG, hippocampus and neocortex. However, at P45 none of these effects were still present, nor did treated Ts65Dn mice exhibit any improvement in hippocampus-dependent tasks. These findings show that treatment with EGCG carried out in the neonatal period rescues numerous trisomy-linked brain alterations. However, even during this, the most critical time window for hippocampal development, EGCG does not elicit enduring effects on the hippocampal physiology

  19. Life-Long Correction of Hyperbilirubinemia with a Neonatal Liver-Specific AAV-Mediated Gene Transfer in a Lethal Mouse Model of Crigler–Najjar Syndrome

    PubMed Central

    Bortolussi, Giulia; Zentillin, Lorena; Vaníkova, Jana; Bockor, Luka; Bellarosa, Cristina; Mancarella, Antonio; Vianello, Eleonora; Tiribelli, Claudio; Giacca, Mauro; Vitek, Libor

    2014-01-01

    Abstract Null mutations in the UGT1A1 gene result in Crigler–Najjar syndrome type I (CNSI), characterized by severe hyperbilirubinemia and constant risk of developing neurological damage. Phototherapy treatment lowers plasma bilirubin levels, but its efficacy is limited and liver transplantation is required. To find alternative therapies, we applied AAV liver-specific gene therapy to a lethal mouse model of CNSI. We demonstrated that a single neonatal hUGT1A1 gene transfer was successful and the therapeutic effect lasted up to 17 months postinjection. The therapeutic effect was mediated by the presence of transcriptionally active double-stranded episomes. We also compared the efficacy of two different gene therapy approaches: liver versus skeletal muscle transgene expression. We observed that 5–8% of normal liver expression and activity levels were sufficient to significantly reduce bilirubin levels and maintain lifelong low plasma bilirubin concentration (3.1±1.5 mg/dl). In contrast, skeletal muscle was not able to efficiently lower bilirubin (6.4±2.0 mg/dl), despite 20–30% of hUgt1a1 expression levels, compared with normal liver. We propose that this remarkable difference in gene therapy efficacy could be related to the absence of the Mrp2 and Mrp3 transporters of conjugated bilirubin in muscle. Taken together, our data support the concept that liver is the best organ for efficient and long-term CNSI gene therapy, and suggest that the use of extra-hepatic tissues should be coupled to the presence of bilirubin transporters. PMID:25072305

  20. Up-regulation of miR-21 and 146a expression and increased DNA damage frequency in a mouse model of polycystic ovary syndrome (PCOS)

    PubMed Central

    Salimi-Asl, Mohammad; Mozdarani, Hossein; Kadivar, Mehdi

    2016-01-01

    Introduction: Polycystic ovary syndrome (PCOS), a multigenic endocrine disorder, is highly associated with low-grade chronic inflammation, however its etiology remains unclear. In this study, we employed dehydroepiandrosterone (DHEA)-treated mice to reveal the molecular mechanism of inflammation and its correlation with oxidative stress in PCOS patients. Methods: miR-21 and miR-146a expression levels were measured using quantitative real-time polymerase chain reaction (qRT-PCR). DNA strand breakage frequency was measured using the single cell gel electrophoresis (SCGE) assay (comet assay) and micronucleus test (MN). CRP levels were measured by ELISA method and ESR values were measured by means of Micro-Dispette (Fisher No: 02-675-256) tubes according to the manufacturer’s instructions. Data were analyzed using one-way ANOVA in SPSS 21.0 software. Results: Our results showed that miR-21 and miR-146a as inflammation markers were upregulated in the sample group in comparison with control group. Erythrocyte sedimentation rate (ESR) and C- reactive protein (CRP) levels were also increased in mouse models of PCOS (p < 0.000). Micronucleated polychromatic erythrocyte (MNPCE) rates per 1000 polychromatic erythrocyte (PCE) significantly increased in DHEA treated mice (6.22 ± 3.28) in comparison with the controls (2.33 ± 2.23, p < 0.000). Moreover, mean arbitrary unit in DHEA treated animals (277 ± 92) was significantly higher than that in controls (184 ± 76, p = 0.005). Conclusion: To conclude, increased DNA strand breakage frequency and increased expression levels of miR-21 and miR-146a in DHEA administrated animals suggest that low grade chronic inflammation and oxidative stress can act as the main etiologies of PCOS. PMID:27525225

  1. Effects of Maternal Choline Supplementation on the Septohippocampal Cholinergic System in the Ts65Dn Mouse Model of Down Syndrome.

    PubMed

    Kelley, Christy M; Ash, Jessica A; Powers, Brian E; Velazquez, Ramon; Alldred, Melissa J; Ikonomovic, Milos D; Ginsberg, Stephen D; Strupp, Barbara J; Mufson, Elliott J

    2016-01-01

    Down syndrome (DS), caused by trisomy of chromosome 21, is marked by intellectual disability (ID) and early onset of Alzheimer's disease (AD) neuropathology including hippocampal cholinergic projection system degeneration. Here we determined the effects of age and maternal choline supplementation (MCS) on hippocampal cholinergic deficits in Ts65Dn mice compared to 2N mice sacrificed at 6-8 and 14-18 months of age. Ts65Dn mice and disomic (2N) littermates sacrificed at ages 6-8 and 14-18 mos were used for an aging study and Ts65Dn and 2N mice derived from Ts65Dn dams were maintained on either a choline-supplemented or a choline-controlled diet (conception to weaning) and examined at 14-18 mos for MCS studies. In the latter, mice were behaviorally tested on the radial arm Morris water maze (RAWM) and hippocampal tissue was examined for intensity of choline acetyltransferase (ChAT) immunoreactivity. Hippocampal ChAT activity was evaluated in a separate cohort. ChAT-positive fiber innervation was significantly higher in the hippocampus and dentate gyrus in Ts65Dn mice compared with 2N mice, independent of age or maternal diet. Similarly, hippocampal ChAT activity was significantly elevated in Ts65Dn mice compared to 2N mice, independent of maternal diet. A significant increase with age was seen in hippocampal cholinergic innervation of 2N mice, but not Ts65Dn mice. Degree of ChAT intensity correlated negatively with spatial memory ability in unsupplemented 2N and Ts65Dn mice, but positively in MCS 2N mice. The increased innervation produced by MCS appears to improve hippocampal function, making this a therapy that may be exploited for future translational approaches in human DS. PMID:26391045

  2. Mice trisomic for a bacterial artificial chromosome with the single-minded 2 gene (Sim2) show phenotypes similar to some of those present in the partial trisomy 16 mouse models of Down syndrome.

    PubMed

    Chrast, R; Scott, H S; Madani, R; Huber, L; Wolfer, D P; Prinz, M; Aguzzi, A; Lipp, H P; Antonarakis, S E

    2000-07-22

    The Drosophila single-minded (sim) transcription factor, is a master regulator of fruitfly neurogenesis. Recently, we have cloned and mapped a human homolog of sim, SIM2, to chromosome 21 in the so-called 'Down syndrome chromosomal region'. Three copies of SIM2 may contribute to some Down syndrome (DS) phenotypes because of the mapping position function as transcriptional repressor, temporal and spatial expression pattern of mouse Sim2, and the potentially analogous role of human SIM2 to that of Drosophila sim during neurogenesis. In order to validate this hypothesis in vivo, we have created the first bacterial artificial chromosome transgenic mice overexpressing a gene possibly involved in DS with only one or two additional copies of mouse Sim2. The transgene was shown to be expressed in the same spatial pattern as the endogenous gene. The mice develop normally, are fertile and do not show detectable histopathological abnormalities. However, detailed analysis of their behavior revealed anxiety-related/reduced exploratory behaviour and sensitivity to pain, phenotypes similar to those also present in other partial trisomy 16 mouse models of DS. Our data therefore suggest that overexpression of SIM2 contributes to some of the complex DS phenotypes. PMID:10915774

  3. The telomeric part of the human chromosome 21 from Cstb to Prmt2 is not necessary for the locomotor and short-term memory deficits observed in the Tc1 mouse model of Down syndrome

    PubMed Central

    Duchon, Arnaud; Pothion, Stéphanie; Brault, Véronique; Sharp, Andrew J.; Tybulewicz, Victor L.J.; Fisher, Elizabeth M.C.; Herault, Yann

    2011-01-01

    Trisomy 21 or Down syndrome (DS) is the most common form of human aneuploid disorder. Increase in the copy number of human chromosome 21 genes leads to several alterations including mental retardation, heart and skeletal dysmorphologies with additional physiological defects. To better understand the genotype and phenotype relationships, several mouse models have been developed, including the transchromosomic Tc1 mouse, which carries an almost complete human chromosome 21, that displays several locomotor and cognitive alterations related to DS. In this report we explore the contribution of the genetic dosage of 47 mouse genes located in the most telomeric part of Hsa21, using a novel model, named Ms4Yah, carrying a deletion of the 2.2Mb Ctsb–Prmt2 genetic interval. We combine this deletion with the Tc1 Hsa21 in a rescue experiment. We could recapitulate most of the Tc1 phenotypes but we found no phenotypes induced by the Ms4Yah and no contribution to the Tc1-induced phenotypes even if we described new alteration in social preference but not in olfaction. Thus we conclude that the genes conserved between mouse and human, found in the most telomeric part of Hsa21, and trisomic in Tc1, are not contributing to the major Tc1 phenotypes, suggesting that the Cstb–Prmt2 region is not playing a major role in locomotor and cognitive deficits found in DS. PMID:21047530

  4. Mouse Genetic Models of Human Brain Disorders.

    PubMed

    Leung, Celeste; Jia, Zhengping

    2016-01-01

    Over the past three decades, genetic manipulations in mice have been used in neuroscience as a major approach to investigate the in vivo function of genes and their alterations. In particular, gene targeting techniques using embryonic stem cells have revolutionized the field of mammalian genetics and have been at the forefront in the generation of numerous mouse models of human brain disorders. In this review, we will first examine childhood developmental disorders such as autism, intellectual disability, Fragile X syndrome, and Williams-Beuren syndrome. We will then explore psychiatric disorders such as schizophrenia and lastly, neurodegenerative disorders including Alzheimer's disease and Parkinson's disease. We will outline the creation of these mouse models that range from single gene deletions, subtle point mutations to multi-gene manipulations, and discuss the key behavioral phenotypes of these mice. Ultimately, the analysis of the models outlined in this review will enhance our understanding of the in vivo role and underlying mechanisms of disease-related genes in both normal brain function and brain disorders, and provide potential therapeutic targets and strategies to prevent and treat these diseases. PMID:27047540

  5. Mouse Genetic Models of Human Brain Disorders

    PubMed Central

    Leung, Celeste; Jia, Zhengping

    2016-01-01

    Over the past three decades, genetic manipulations in mice have been used in neuroscience as a major approach to investigate the in vivo function of genes and their alterations. In particular, gene targeting techniques using embryonic stem cells have revolutionized the field of mammalian genetics and have been at the forefront in the generation of numerous mouse models of human brain disorders. In this review, we will first examine childhood developmental disorders such as autism, intellectual disability, Fragile X syndrome, and Williams-Beuren syndrome. We will then explore psychiatric disorders such as schizophrenia and lastly, neurodegenerative disorders including Alzheimer’s disease and Parkinson’s disease. We will outline the creation of these mouse models that range from single gene deletions, subtle point mutations to multi-gene manipulations, and discuss the key behavioral phenotypes of these mice. Ultimately, the analysis of the models outlined in this review will enhance our understanding of the in vivo role and underlying mechanisms of disease-related genes in both normal brain function and brain disorders, and provide potential therapeutic targets and strategies to prevent and treat these diseases. PMID:27047540

  6. Mouse Models of Rheumatoid Arthritis.

    PubMed

    Caplazi, P; Baca, M; Barck, K; Carano, R A D; DeVoss, J; Lee, W P; Bolon, B; Diehl, L

    2015-09-01

    Rheumatoid arthritis (RA) is a chronic debilitating autoimmune disorder characterized by synovitis that leads to cartilage and bone erosion by invading fibrovascular tissue. Mouse models of RA recapitulate many features of the human disease. Despite the availability of medicines that are highly effective in many patient populations, autoimmune diseases (including RA) remain an area of active biomedical research, and consequently mouse models of RA are still extensively used for mechanistic studies and validation of therapeutic targets. This review aims to integrate morphologic features with model biology and cover the key characteristics of the most commonly used induced and spontaneous mouse models of RA. Induced models emphasized in this review include collagen-induced arthritis and antibody-induced arthritis. Collagen-induced arthritis is an example of an active immunization strategy, whereas antibody- induced arthritis models, such as collagen antibody-induced arthritis and K/BxN antibody transfer arthritis, represent examples of passive immunization strategies. The coverage of spontaneous models in this review is focused on the TNFΔ (ARE) mouse, in which arthritis results from overexpression of TNF-α, a master proinflammatory cytokine that drives disease in many patients. PMID:26063174

  7. Berberine Improves Intestinal Motility and Visceral Pain in the Mouse Models Mimicking Diarrhea-Predominant Irritable Bowel Syndrome (IBS-D) Symptoms in an Opioid-Receptor Dependent Manner

    PubMed Central

    Pan, Qiuhui; Fichna, Jakub; Zheng, Lijun; Wang, Kesheng; Yu, Zhen; Li, Yongyu; Li, Kun; Song, Aihong; Liu, Zhongchen; Song, Zhenshun; Kreis, Martin

    2015-01-01

    Background and Aims Berberine and its derivatives display potent analgesic, anti-inflammatory and anticancer activity. Here we aimed at characterizing the mechanism of action of berberine in the gastrointestinal (GI) tract and cortical neurons using animal models and in vitro tests. Methods The effect of berberine was characterized in murine models mimicking diarrhea-predominant irritable bowel syndrome (IBS-D) symptoms. Then the opioidantagonists were used to identify the receptors involved. Furthermore, the effect of berberineon opioid receptors expression was established in the mouse intestine and rat fetal cortical neurons. Results In mouse models, berberine prolonged GI transit and time to diarrhea in a dose-dependent manner, and significantly reduced visceral pain. In physiological conditions the effects of berberine were mediated by mu- (MOR) and delta- (DOR) opioidreceptors; hypermotility, excessive secretion and nociception were reversed by berberine through MOR and DOR-dependent action. We also found that berberine increased the expression of MOR and DOR in the mouse bowel and rat fetal cortical neurons. Conclusion Berberine significantly improved IBS-D symptoms in animal models, possibly through mu- and delta- opioid receptors. Berberine may become a new drug candidate for the successful treatment of IBS-D in clinical conditions. PMID:26700862

  8. Mouse models of human cancer.

    PubMed

    Böck, Barbara C; Stein, Ulrike; Schmitt, Clemens A; Augustin, Hellmut G

    2014-09-01

    The Helmholtz Alliance Preclinical Comprehensive Cancer Center (PCCC; www.helmholtz-pccc.de) hosted the "1st International Kloster Seeon Meeting on Mouse Models of Human Cancer" in the Seeon monastery (Germany) from March 8 to 11, 2014. The meeting focused on the development and application of novel mouse models in tumor research and high-throughput technologies to overcome one of the most critical bottlenecks in translational bench-to-bedside tumor biology research. Moreover, the participants discussed basic molecular mechanisms underlying tumor initiation, progression, metastasis, and therapy resistance, which are the prerequisite for the development of novel treatment strategies and clinical applications in cancer therapy. PMID:25136075

  9. Behavioral and Neuroanatomical Phenotypes in Mouse Models of Autism.

    PubMed

    Ellegood, Jacob; Crawley, Jacqueline N

    2015-07-01

    In order to understand the consequences of the mutation on behavioral and biological phenotypes relevant to autism, mutations in many of the risk genes for autism spectrum disorder have been experimentally generated in mice. Here, we summarize behavioral outcomes and neuroanatomical abnormalities, with a focus on high-resolution magnetic resonance imaging of postmortem mouse brains. Results are described from multiple mouse models of autism spectrum disorder and comorbid syndromes, including the 15q11-13, 16p11.2, 22q11.2, Cntnap2, Engrailed2, Fragile X, Integrinβ3, MET, Neurexin1a, Neuroligin3, Reelin, Rett, Shank3, Slc6a4, tuberous sclerosis, and Williams syndrome models, and inbred strains with strong autism-relevant behavioral phenotypes, including BTBR and BALB. Concomitant behavioral and neuroanatomical abnormalities can strengthen the interpretation of results from a mouse model, and may elevate the usefulness of the model system for therapeutic discovery. PMID:26036957

  10. Mouse models of myasthenia gravis.

    PubMed

    Ban, Joanne; Phillips, William D

    2015-01-01

    Myasthenia gravis is a muscle weakness disease characterized by autoantibodies that target components of the neuromuscular junction, impairing synaptic transmission. The most common form of myasthenia gravis involves antibodies that bind the nicotinic acetylcholine receptors in the postsynaptic membrane. Many of the remaining cases are due to antibodies against muscle specific tyrosine kinase (MuSK). Recently, autoantibodies against LRP4 (another component of the MuSK signaling complex in the postsynaptic membrane) were identified as the likely cause of myasthenia gravis in some patients. Fatiguing weakness is the common symptom in all forms of myasthenia gravis, but muscles of the body are differentially affected, for reasons that are not fully understood. Much of what we have learnt about the immunological and neurobiological aspects of the pathogenesis derives from mouse models. The most widely used mouse models involve either passive transfer of autoantibodies, or active immunization of the mouse with acetylcholine receptors or MuSK protein. These models can provide a robust replication of many of the features of the human disease. Depending upon the protocol, acute fatiguing weakness develops 2 - 14 days after the start of autoantibody injections (passive transfer) or might require repeated immunizations over several weeks (active models). Here we review mouse models of myasthenia gravis, including what they have contributed to current understanding of the pathogenic mechanisms and their current application to the testing of therapeutics. PMID:25777761

  11. Environmental enrichment decreases GABAergic inhibition and improves cognitive abilities, synaptic plasticity, and visual functions in a mouse model of Down syndrome

    PubMed Central

    Begenisic, Tatjana; Spolidoro, Maria; Braschi, Chiara; Baroncelli, Laura; Milanese, Marco; Pietra, Gianluca; Fabbri, Maria E.; Bonanno, Giambattista; Cioni, Giovanni; Maffei, Lamberto; Sale, Alessandro

    2011-01-01

    Down syndrome (DS) is the most common genetic disorder associated with mental retardation. It has been repeatedly shown that Ts65Dn mice, the prime animal model for DS, have severe cognitive and neural plasticity defects due to excessive inhibition. We report that increasing sensory-motor stimulation in adulthood through environmental enrichment (EE) reduces brain inhibition levels and promotes recovery of spatial memory abilities, hippocampal synaptic plasticity, and visual functions in adult Ts65Dn mice. PMID:22207837

  12. Mouse models of the laminopathies

    SciTech Connect

    Stewart, Colin L. . E-mail: stewartc@ncifcrf.gov; Kozlov, Serguei; Fong, Loren G.; Young, Stephen G. . E-mail: sgyoung@mednet.ucla.edu

    2007-06-10

    The A and B type lamins are nuclear intermediate filament proteins that comprise the bulk of the nuclear lamina, a thin proteinaceous structure underlying the inner nuclear membrane. The A type lamins are encoded by the lamin A gene (LMNA). Mutations in this gene have been linked to at least nine diseases, including the progeroid diseases Hutchinson-Gilford progeria and atypical Werner's syndromes, striated muscle diseases including muscular dystrophies and dilated cardiomyopathies, lipodystrophies affecting adipose tissue deposition, diseases affecting skeletal development, and a peripheral neuropathy. To understand how different diseases arise from different mutations in the same gene, mouse lines carrying some of the same mutations found in the human diseases have been established. We, and others have generated mice with different mutations that result in progeria, muscular dystrophy, and dilated cardiomyopathy. To further our understanding of the functions of the lamins, we also created mice lacking lamin B1, as well as mice expressing only one of the A type lamins. These mouse lines are providing insights into the functions of the lamina and how changes to the lamina affect the mechanical integrity of the nucleus as well as signaling pathways that, when disrupted, may contribute to the disease.

  13. Enhanced anxiety and stress-induced corticosterone release are associated with increased Crh expression in a mouse model of Rett syndrome

    PubMed Central

    McGill, Bryan E.; Bundle, Sharyl F.; Yaylaoglu, Murat B.; Carson, James P.; Thaller, Christina; Zoghbi, Huda Y.

    2006-01-01

    Rett syndrome (RTT), a postnatal neurodevelopmental disorder, is caused by mutations in the methyl-CpG-binding protein 2 (MECP2) gene. Children with RTT display cognitive and motor abnormalities as well as autistic features. We studied mice bearing a truncated Mecp2 allele (Mecp2308/Y mice) and found evidence of increased anxiety-like behavior and an abnormal stress response as evidenced by elevated serum corticosterone levels. We found increased corticotropin-releasing hormone (Crh) gene expression in the paraventricular nucleus of the hypothalamus, the central amygdala, and the bed nucleus of the stria terminalis. Finally, we discovered that MeCP2 binds the Crh promoter, which is enriched for methylated CpG dinucleotides. In contrast, the MeCP2308 protein was not detected at the Crh promoter. This study identifies Crh as a target of MeCP2 and implicates Crh overexpression in the development of specific features of the Mecp2308/Y mouse, thereby providing opportunities for clinical investigation and therapeutic intervention in RTT. PMID:17108082

  14. Mouse Models for the Dissection of CHD7 Functions in Eye Development and the Molecular Basis for Ocular Defects in CHARGE Syndrome

    PubMed Central

    Gage, Philip J.; Hurd, Elizabeth A.; Martin, Donna M.

    2015-01-01

    Purpose CHARGE syndrome (Coloboma of the eye, Heart defects, Atresia of the choanae, Retardation of growth and/or development, Genital and/or urinary tract abnormalities, and Ear abnormalities and deafness) is the second-leading cause of deaf-blindness after Usher syndrome. Heterozygous mutations in CHD7 cause CHARGE syndrome in 70% to 90% of patients. We tested the hypothesis that tissue-specific mutant mice provide models for molecularly dissecting CHD7 functions during eye development. Methods The conditional Chd7flox allele was mated together with tissue-specific Cre transgenes. Immunohistochemistry was used to determine the normal CHD7 pattern in the early eye primordia and to assess Chd7 mutants for expression of region-specific protein markers. Results CHD7 is present in the neural ectoderm and surface ectoderm of the eye. Deletion from neural and surface ectoderm results in severely dysmorphic eyes generally lacking recognizable optic cup structures and small lenses. Deletion from the neural ectoderm results in similar defects. Deletion from the surface ectoderm results in eyes with smaller lenses. Lens tissue and the major subdivisions of the neural ectoderm are present following conditional deletion of Chd7 from the neural ectoderm. Closure of the optic fissure depends on the Chd7 gene dose within the neural ectoderm. Conclusions Eye development requires CHD7 in multiple embryonic tissues. Lens development requires CHD7 in the surface ectoderm, whereas optic cup and stalk morphogenesis require CHD7 in the neural ectoderm. CHD7 is not absolutely required for specification of the major subdivisions within the neural ectoderm. As in humans, normal eye development in mice is sensitive to Chd7 haploinsufficiency. These data indicate the Chd7 mutant mice are models for determining the molecular etiology of ocular defects in CHARGE syndrome. PMID:26670829

  15. Modelling Down Syndrome

    ERIC Educational Resources Information Center

    Buckley, Frank

    2008-01-01

    Animal models are extensively used in genetics, neuroscience and biomedical research. Recent studies illustrate the usefulness and the challenges of research utilising genetically engineered mice to explore the developmental biology of Down syndrome. These studies highlight many of the issues at the centre of what we understand about Down…

  16. Do mouse models of allergic asthma mimic clinical disease?

    PubMed

    Epstein, Michelle M

    2004-01-01

    Experimental mouse models of allergic asthma established almost 10 years ago offered new opportunities to study disease pathogenesis and to develop new therapeutics. These models focused on the factors governing the allergic immune response, on modeling clinical behavior of allergic asthma, and led to insights into pulmonary pathophysiology. Although mouse models rarely completely reproduce all the features of human disease, after sensitization and respiratory tract challenges with antigen, wild-type mice develop a clinical syndrome that closely resembles allergic asthma, characterized by eosinophilic lung inflammation, airway hyperresponsiveness (AHR), increased IgE, mucus hypersecretion, and eventually, airway remodeling. There are, however, differences between mouse and human physiology that threaten to limit the value of mouse models. Three examples of such differences relate to both clinical manifestations of disease and underlying pathogenesis. First, in contrast to patients who have increased methacholine-induced AHR even when they are symptom-free, mice exhibit only transient methacholine-induced AHR following allergen exposure. Second, chronic allergen exposure in patients leads to chronic allergic asthma, whereas repeated exposures in sensitized mice causes suppression of disease. Third, IgE and mast cells, in humans, mediate early- and late-phase allergic responses, though both are unnecessary for the generation of allergic asthma in mice. Taken together, these observations suggest that mouse models of allergic asthma are not exact replicas of human disease and thus, question the validity of these models. However, observations from mouse models of allergic asthma support many existing paradigms, although some novel discoveries in mice have yet to be verified in patients. This review presents an overview of the clinical aspects of disease in mouse models of allergic asthma emphasizing (1). the factors influencing the pathophysiological responses during

  17. Aging Research Using Mouse Models

    PubMed Central

    Ackert-Bicknell, Cheryl L.; Anderson, Laura; Sheehan, Susan; Hill, Warren G.; Chang, Bo; Churchill, Gary A.; Chesler, Elissa J.; Korstanje, Ron; Peters, Luanne L.

    2015-01-01

    Despite the dramatic increase in human lifespan over the past century, there remains pronounced variability in “health-span”, or the period of time in which one is generally healthy and free of disease. Much of the variability in health-span and lifespan is thought to be genetic in origin. Understanding the genetic mechanisms of aging and identifying ways to boost longevity is a primary goal in aging research. Here, we describe a pipeline of phenotypic assays for assessing mouse models of aging. This pipeline includes behavior/cognition testing, body composition analysis, and tests of kidney function, hematopoiesis, immune function and physical parameters. We also describe study design methods for assessing lifespan and health-span, and other important considerations when conducting aging research in the laboratory mouse. The tools and assays provided can assist researchers with understanding the correlative relationships between age-associated phenotypes and, ultimately, the role of specific genes in the aging process. PMID:26069080

  18. Cell-Type Specific Channelopathies in the Prefrontal Cortex of the fmr1-/y Mouse Model of Fragile X Syndrome1,2,3

    PubMed Central

    Johnston, Daniel; Brager, Darrin H.

    2015-01-01

    Abstract Fragile X syndrome (FXS) is caused by transcriptional silencing of the fmr1 gene resulting in the loss of fragile X mental retardation protein (FMRP) expression. FXS patients display several behavioral phenotypes associated with prefrontal cortex (PFC) dysfunction. Voltage-gated ion channels, some of which are regulated by FMRP, heavily influence PFC neuron function. Although there is evidence for brain region-specific alterations to the function a single type of ion channel in FXS, it is unclear whether subtypes of principal neurons within a brain region are affected uniformly. We tested for alterations to ion channels critical in regulating neural excitability in two subtypes of prefrontal L5 pyramidal neurons. Using somatic and dendritic patch-clamp recordings, we provide evidence that the functional expression of h-channels (Ih) is down-regulated, whereas A-type K+ channel function is up-regulated in pyramidal tract-projecting (PT) neurons in the fmr1-/y mouse PFC. This is the opposite pattern of results from published findings from hippocampus where Ih is up-regulated and A-type K+ channel function is down-regulated. Additionally, we find that somatic Kv1-mediated current is down-regulated, resulting in increased excitability of fmr1-/y PT neurons. Importantly, these h- and K+ channel differences do not extend to neighboring intratelencephalic-projecting neurons. Thus, the absence of FMRP has divergent effects on the function of individual types of ion channels not only between brain regions, but also variable effects across cell types within the same brain region. Given the importance of ion channels in regulating neural circuits, these results suggest cell-type-specific phenotypes for the disease. PMID:26601124

  19. The free radical scavenger Trolox dampens neuronal hyperexcitability, reinstates synaptic plasticity, and improves hypoxia tolerance in a mouse model of Rett syndrome

    PubMed Central

    Janc, Oliwia A.; Müller, Michael

    2014-01-01

    Rett syndrome (RS) causes severe cognitive impairment, loss of speech, epilepsy, and breathing disturbances with intermittent hypoxia. Also mitochondria are affected; a subunit of respiratory complex III is dysregulated, the inner mitochondrial membrane is leaking protons, and brain ATP levels seem reduced. Our recent assessment of mitochondrial function in MeCP2 (methyl-CpG-binding protein 2)-deficient mouse (Mecp2-/y) hippocampus confirmed early metabolic alterations, an increased oxidative burden, and a more vulnerable cellular redox balance. As these changes may contribute to the manifestation of symptoms and disease progression, we now evaluated whether free radical scavengers are capable of improving neuronal and mitochondrial function in RS. Acute hippocampal slices of adult mice were incubated with the vitamin E derivative Trolox for 3–5 h. In Mecp2-/y slices this treatment dampened neuronal hyperexcitability, improved synaptic short-term plasticity, and fully restored synaptic long-term potentiation (LTP). Furthermore, Trolox specifically attenuated the increased hypoxia susceptibility of Mecp2-/y slices. Also, the anticonvulsive effects of Trolox were assessed, but the severity of 4-aminopyridine provoked seizure-like discharges was not significantly affected. Adverse side effects of Trolox on mitochondria can be excluded, but clear indications for an improvement of mitochondrial function were not found. Since several ion-channels and neurotransmitter receptors are redox modulated, the mitochondrial alterations and the associated oxidative burden may contribute to the neuronal dysfunction in RS. We confirmed in Mecp2-/y hippocampus that Trolox dampens neuronal hyperexcitability, reinstates synaptic plasticity, and improves the hypoxia tolerance. Therefore, radical scavengers are promising compounds for the treatment of neuronal dysfunction in RS and deserve further detailed evaluation. PMID:24605086

  20. Reversible lacrimal gland-protective regulatory T-cell dysfunction underlies male-specific autoimmune dacryoadenitis in the non-obese diabetic mouse model of Sjögren syndrome.

    PubMed

    Lieberman, Scott M; Kreiger, Portia A; Koretzky, Gary A

    2015-06-01

    CD4(+) CD25(+) Foxp3(+) regulatory T (Treg) cells are required to maintain immunological tolerance; however, defects in specific organ-protective Treg cell functions have not been demonstrated in organ-specific autoimmunity. Non-obese diabetic (NOD) mice spontaneously develop lacrimal and salivary gland autoimmunity and are a well-characterized model of Sjögren syndrome. Lacrimal gland disease in NOD mice is male-specific, but the role of Treg cells in this sex-specificity is not known. This study aimed to determine if male-specific autoimmune dacryoadenitis in the NOD mouse model of Sjögren syndrome is the result of lacrimal gland-protective Treg cell dysfunction. An adoptive transfer model of Sjögren syndrome was developed by transferring cells from the lacrimal gland-draining cervical lymph nodes of NOD mice to lymphocyte-deficient NOD-SCID mice. Transfer of bulk cervical lymph node cells modelled the male-specific dacryoadenitis that spontaneously develops in NOD mice. Female to female transfers resulted in dacryoadenitis if the CD4(+) CD25(+) Treg-enriched population was depleted before transfer; however, male to male transfers resulted in comparable dacryoadenitis regardless of the presence or absence of Treg cells within the donor cell population. Hormone manipulation studies suggested that this Treg cell dysfunction was mediated at least in part by androgens. Surprisingly, male Treg cells were capable of preventing the transfer of dacryoadenitis to female recipients. These data suggest that male-specific factors promote reversible dysfunction of lacrimal gland-protective Treg cells and, to our knowledge, form the first evidence for reversible organ-protective Treg cell dysfunction in organ-specific autoimmunity. PMID:25581706

  1. Mouse Models of Tumor Immunotherapy.

    PubMed

    Ngiow, Shin Foong; Loi, Sherene; Thomas, David; Smyth, Mark J

    2016-01-01

    Immunotherapy is now evolving into a major therapeutic option for cancer patients. Such clinical advances also promote massive interest in the search for novel immunotherapy targets, and to understand the mechanism of action of current drugs. It is projected that a series of novel immunotherapy agents will be developed and assessed for their therapeutic activity. In light of this, in vivo experimental mouse models that recapitulate human malignancies serve as valuable tools to validate the efficacy and safety profile of immunotherapy agents, before their transition into clinical trials. In this review, we will discuss the major classes of experimental mouse models of cancer commonly used for immunotherapy assessment and provide examples to guide the selection of appropriate models. We present some new data concerning the utility of a carcinogen-induced tumor model for comparing immunotherapies and combining immunotherapy with chemotherapy. We will also highlight some recent advances in experimental modeling of human malignancies in mice that are leading towards personalized therapy in patients. PMID:26922998

  2. Loss of ovarian function in the VCD mouse-model of menopause leads to insulin resistance and a rapid progression into the metabolic syndrome.

    PubMed

    Romero-Aleshire, Melissa J; Diamond-Stanic, Maggie K; Hasty, Alyssa H; Hoyer, Patricia B; Brooks, Heddwen L

    2009-09-01

    Factors comprising the metabolic syndrome occur with increased incidence in postmenopausal women. To investigate the effects of ovarian failure on the progression of the metabolic syndrome, female B(6)C(3)F(1) mice were treated with 4-vinylcyclohexene diepoxide (VCD) and fed a high-fat (HF) diet for 16 wk. VCD destroys preantral follicles, causing early ovarian failure and is a well-characterized model for the gradual onset of menopause. After 12 wk on a HF diet, VCD-treated mice had developed an impaired glucose tolerance, whereas cycling controls were unaffected [12 wk AUC HF mice 13,455 +/- 643 vs. HF/VCD 17,378 +/- 1140 mg/dl/min, P < 0.05]. After 16 wk on a HF diet, VCD-treated mice had significantly higher fasting insulin levels (HF 5.4 +/- 1.3 vs. HF/VCD 10.1 +/- 1.4 ng/ml, P < 0.05) and were significantly more insulin resistant (HOMA-IR) than cycling controls on a HF diet (HF 56.2 +/- 16.7 vs. HF/VCD 113.1 +/- 19.6 mg/dl x microU/ml, P < 0.05). All mice on a HF diet gained more weight than mice on a standard diet, and weight gain in HF/VCD mice was significantly increased compared with HF cycling controls. Interestingly, even without a HF diet, progression into VCD-induced menopause caused a significant increase in cholesterol and free fatty acids. Furthermore, in mice fed a standard diet (6% fat), insulin resistance developed 4 mo after VCD-induced ovarian failure. Insulin resistance following ovarian failure (menopause) was prevented by estrogen replacement. Studies here demonstrate that ovarian failure (menopause) accelerates progression into the metabolic syndrome and that estrogen replacement prevents the onset of insulin resistance in VCD-treated mice. Thus, the VCD model of menopause provides a physiologically relevant means of studying how sex hormones influence the progression of the metabolic syndrome. PMID:19439618

  3. Occupational Overuse Syndrome (Technological Diseases): Carpal Tunnel Syndrome, a Mouse Shoulder, Cervical Pain Syndrome

    PubMed Central

    Tiric-Campara, Merita; Krupic, Ferid; Biscevic, Mirza; Spahic, Emina; Maglajlija, Kerima; Masic, Zlatan; Zunic, Lejla; Masic, Izet

    2014-01-01

    ABSTRACT Technological diseases are diseases of the modern era. Some are caused by occupational exposures, and are marked with direct professional relation, or the action of harmful effects in the workplace. Due to the increasing incidence of these diseases on specific workplaces which may be caused by one or more causal factors present in the workplace today, these diseases are considered as professional diseases. Severity of technological disease usually responds to the level and duration of exposure, and usually occurs after many years of exposure to harmful factor. Technological diseases occur due to excessive work at the computer, or excessive use of keyboards and computer mice, especially the non-ergonomic ones. This paper deals with the diseases of the neck, shoulder, elbow and wrist (cervical radiculopathy, mouse shoulder and carpal tunnel syndrome), as is currently the most common diseases of technology in our country and abroad. These three diseases can be caused by long-term load and physical effort, and are tied to specific occupations, such as occupations associated with prolonged sitting, working at the computer and work related to the fixed telephone communication, as well as certain types of sports (tennis, golf and others). PMID:25568584

  4. Mouse Model for Protein Tyrosine Phosphatase D (PTPRD) Associations with Restless Leg Syndrome or Willis-Ekbom Disease and Addiction: Reduced Expression Alters Locomotion, Sleep Behaviors and Cocaine-Conditioned Place Preference

    PubMed Central

    Drgonova, Jana; Walther, Donna; Wang, Katherine J; Hartstein, G Luke; Lochte, Bryson; Troncoso, Juan; Uetani, Noriko; Iwakura, Yoichiro; Uhl, George R

    2015-01-01

    The receptor type protein tyrosine phosphatase D (PTPRD) gene encodes a cell adhesion molecule likely to influence development and connections of addiction-, locomotion- and sleep-related brain circuits in which it is expressed. The PTPRD gene harbors genome-wide association signals in studies of restless leg syndrome (Willis-Ekbom disease [WED]/restless leg syndrome [RLS]; p < 10−8) and addiction-related phenotypes (clusters of nearby single nucleotide polymorphisms [SNPs] with 10−2 > p > 10−8 associations in several reports). We now report work that seeks (a) association between PTPRD genotypes and expression of its mRNA in postmortem human brains and (b) RLS-related, addiction-related and comparison behavioral phenotypes in hetero- and homozygous PTPRD knockout mice. We identify associations between PTPRD SNPs and levels of PTPRD mRNA in human brain samples that support validity of mouse models with altered PTPRD expression. Knockouts display less behaviorally defined sleep at the end of their active periods. Heterozygotes move more despite motor weakness/impersistence. Heterozygotes display shifted dose-response relationships for cocaine reward. They display greater preference for places paired with 5 mg/kg cocaine and less preference for places paired with 10 or 20 mg/kg. The combined data provide support for roles for common, level-of-expression PTPRD variation in locomotor, sleep and drug reward phenotypes relevant to RLS and addiction. Taken together, mouse and human results identify PTPRD as a novel therapeutic target for RLS and addiction phenotypes. PMID:26181631

  5. Mouse models of congenital cataract.

    PubMed

    Graw, J

    1999-06-01

    Mouse mutants affecting lens development are excellent models for corresponding human disorders. The mutant aphakia has been characterised by bilaterally aphakic eyes (Varnum and Stevens, J Hered 1968;59:147-50); the corresponding gene was mapped to chromosome 19 (Varnum and Stevens, Mouse News Lett 1975;53:35). Recent investigations in our laboratory refined the linkage of 0.6 cM proximal to the marker D19Mit10. Several candidate genes have been excluded (Chuk1, Fgf8, Lbp1, Npm3, Pax2, Pitx3). The Cat3 mutations are characterised by vacuolated lenses caused by alterations in the initial secondary lens fibre cell differentiation. Secondary malformations develop at the cornea and iris, but the retina remains unaffected. The mutation has been mapped to chromosome 10 close to the markers D10Mit41 and D10Mit95. Several candidate genes have been excluded (Dcn, Elk3, Ldc, Mell8, Tr2-11). The series of Cat2 mutations have been mapped close to the gamma-crystallin genes (Cryg; Löster et al., Genomics 1994;23:240-2). The Cat2nop mutation is characterised by a mutation in the third exon of Crygb leading to a truncated gamma B-crystallin and the termination of lens fibre cell differentiation. The Cat2 mutants are interesting models for human cataracts caused by mutations in the human CRYG genes at chromosome 2q32-35. PMID:10627821

  6. Mouse models for liver cancer.

    PubMed

    Bakiri, Latifa; Wagner, Erwin F

    2013-04-01

    Hepatocellular carcinoma (HCC), the most common form of primary liver cancer is the third leading cause of cancer-related cell death in human and the fifth in women worldwide. The incidence of HCC is increasing despite progress in identifying risk factors, understanding disease etiology and developing anti-viral strategies. Therapeutic options are limited and survival after diagnosis is poor. Therefore, better preventive, diagnostic and therapeutic tools are urgently needed, in particular given the increased contribution from systemic metabolic disease to HCC incidence worldwide. In the last three decades, technological advances have facilitated the generation of genetically engineered mouse models (GEMMs) to mimic the alterations frequently observed in human cancers or to conduct intervention studies and assess the relevance of candidate gene networks in tumor establishment, progression and maintenance. Because these studies allow molecular and cellular manipulations impossible to perform in patients, GEMMs have improved our understanding of this complex disease and represent a source of great potential for mechanism-based therapy development. In this review, we provide an overview of the current state of HCC modeling in the mouse, highlighting successes, current challenges and future opportunities. PMID:23428636

  7. Nucleotide excision repair deficient mouse models and neurological disease.

    PubMed

    Niedernhofer, Laura J

    2008-07-01

    Nucleotide excision repair (NER) is a highly conserved mechanism to remove helix-distorting DNA base damage. A major substrate for NER is DNA damage caused by environmental genotoxins, most notably ultraviolet radiation. Xeroderma pigmentosum, Cockayne syndrome and trichothiodystrophy are three human diseases caused by inherited defects in NER. The symptoms and severity of these diseases vary dramatically, ranging from profound developmental delay to cancer predisposition and accelerated aging. All three syndromes include neurological disease, indicating an important role for NER in protecting against spontaneous DNA damage as well. To study the pathophysiology caused by DNA damage, numerous mouse models of NER-deficiency were generated by knocking-out genes required for NER or knocking-in disease-causing human mutations. This review explores the utility of these mouse models to study neurological disease caused by NER-deficiency. PMID:18272436

  8. Mouse Models Recapitulating Human Adrenocortical Tumors: What Is Lacking?

    PubMed Central

    Leccia, Felicia; Batisse-Lignier, Marie; Sahut-Barnola, Isabelle; Val, Pierre; Lefrançois-Martinez, A-Marie; Martinez, Antoine

    2016-01-01

    Adrenal cortex tumors are divided into benign forms, such as primary hyperplasias and adrenocortical adenomas (ACAs), and malignant forms or adrenocortical carcinomas (ACCs). Primary hyperplasias are rare causes of adrenocorticotropin hormone-independent hypercortisolism. ACAs are the most common type of adrenal gland tumors and they are rarely “functional,” i.e., producing steroids. When functional, adenomas result in endocrine disorders, such as Cushing’s syndrome (hypercortisolism) or Conn’s syndrome (hyperaldosteronism). By contrast, ACCs are extremely rare but highly aggressive tumors that may also lead to hypersecreting syndromes. Genetic analyses of patients with sporadic or familial forms of adrenocortical tumors (ACTs) led to the identification of potentially causative genes, most of them being involved in protein kinase A (PKA), Wnt/β-catenin, and P53 signaling pathways. Development of mouse models is a crucial step to firmly establish the functional significance of candidate genes, to dissect mechanisms leading to tumors and endocrine disorders, and in fine to provide in vivo tools for therapeutic screens. In this article, we will provide an overview on the existing mouse models (xenografted and genetically engineered) of ACTs by focusing on the role of PKA and Wnt/β-catenin pathways in this context. We will discuss the advantages and limitations of models that have been developed heretofore and we will point out necessary improvements in the development of next generation mouse models of adrenal diseases. PMID:27471492

  9. Defective synaptic transmission and structure in the dentate gyrus and selective fear memory impairment in the Rsk2 mutant mouse model of Coffin-Lowry syndrome.

    PubMed

    Morice, Elise; Farley, Séverine; Poirier, Roseline; Dallerac, Glenn; Chagneau, Carine; Pannetier, Solange; Hanauer, André; Davis, Sabrina; Vaillend, Cyrille; Laroche, Serge

    2013-10-01

    The Coffin-Lowry syndrome (CLS) is a syndromic form of intellectual disability caused by loss-of-function of the RSK2 serine/threonine kinase encoded by the rsk2 gene. Rsk2 knockout mice, a murine model of CLS, exhibit spatial learning and memory impairments, yet the underlying neural mechanisms are unknown. In the current study, we examined the performance of Rsk2 knockout mice in cued, trace and contextual fear memory paradigms and identified selective deficits in the consolidation and reconsolidation of hippocampal-dependent fear memories as task difficulty and hippocampal demand increase. Electrophysiological, biochemical and electron microscopy analyses were carried out in the dentate gyrus of the hippocampus to explore potential alterations in neuronal functions and structure. In vivo and in vitro electrophysiology revealed impaired synaptic transmission, decreased network excitability and reduced AMPA and NMDA conductance in Rsk2 knockout mice. In the absence of RSK2, standard measures of short-term and long-term potentiation (LTP) were normal, however LTP-induced CREB phosphorylation and expression of the transcription factors EGR1/ZIF268 were reduced and that of the scaffolding protein SHANK3 was blocked, indicating impaired activity-dependent gene regulation. At the structural level, the density of perforated and non-perforated synapses and of multiple spine boutons was not altered, however, a clear enlargement of spine neck width and post-synaptic densities indicates altered synapse ultrastructure. These findings show that RSK2 loss-of-function is associated in the dentate gyrus with multi-level alterations that encompass modifications of glutamate receptor channel properties, synaptic transmission, plasticity-associated gene expression and spine morphology, providing novel insights into the mechanisms contributing to cognitive impairments in CLS. PMID:23742761

  10. The polyphenols resveratrol and epigallocatechin-3-gallate restore the severe impairment of mitochondria in hippocampal progenitor cells from a Down syndrome mouse model.

    PubMed

    Valenti, Daniela; de Bari, Lidia; de Rasmo, Domenico; Signorile, Anna; Henrion-Caude, Alexandra; Contestabile, Andrea; Vacca, Rosa Anna

    2016-06-01

    Mitochondrial dysfunctions critically impair nervous system development and are potentially involved in the pathogenesis of various neurodevelopmental disorders, including Down syndrome (DS), the most common genetic cause of intellectual disability. Previous studies from our group demonstrated impaired mitochondrial activity in peripheral cells from DS subjects and the efficacy of epigallocatechin-3-gallate (EGCG) - a natural polyphenol major component of green tea - to counteract the mitochondrial energy deficit. In this study, to gain insight into the possible role of mitochondria in DS intellectual disability, mitochondrial functions were analyzed in neural progenitor cells (NPCs) isolated from the hippocampus of Ts65Dn mice, a widely used model of DS which recapitulates many major brain structural and functional phenotypes of the syndrome, including impaired hippocampal neurogenesis. We found that, during NPC proliferation, mitochondrial bioenergetics and mitochondrial biogenic program were strongly compromised in Ts65Dn cells, but not associated with free radical accumulation. These data point to a central role of mitochondrial dysfunction as an inherent feature of DS and not as a consequence of cell oxidative stress. Further, we disclose that, besides EGCG, also the natural polyphenol resveratrol, which displays a neuroprotective action in various human diseases but never tested in DS, restores oxidative phosphorylation efficiency and mitochondrial biogenesis, and improves proliferation of NPCs. These effects were associated with the activation of PGC-1α/Sirt1/AMPK axis by both polyphenols. This research paves the way for using nutraceuticals as a potential therapeutic tool in preventing or managing some energy deficit-associated DS clinical manifestations. PMID:26964795

  11. Mouse Models of SCN5A-Related Cardiac Arrhythmias

    PubMed Central

    Derangeon, Mickael; Montnach, Jérôme; Baró, Isabelle; Charpentier, Flavien

    2012-01-01

    Mutations of SCN5A gene, which encodes the α-subunit of the voltage-gated Na+ channel NaV1.5, underlie hereditary cardiac arrhythmic syndromes such as the type 3 long QT syndrome, cardiac conduction diseases, the Brugada syndrome, the sick sinus syndrome, a trial standstill, and numerous overlap syndromes. Patch-clamp studies in heterologous expression systems have provided important information to understand the genotype-phenotype relationships of these diseases. However, they could not clarify how SCN5A mutations can be responsible for such a large spectrum of diseases, for the late age of onset or the progressiveness of some of these diseases and for the overlapping syndromes. Genetically modified mice rapidly appeared as promising tools for understanding the pathophysiological mechanisms of cardiac SCN5A-related arrhythmic syndromes and several mouse models have been established. This review presents the results obtained on these models that, for most of them, recapitulate the clinical phenotypes of the patients. This includes two models knocked out for Nav1.5 β1 and β3 auxiliary subunits that are also discussed. Despite their own limitations that we point out, the mouse models still appear as powerful tools to elucidate the pathophysiological mechanisms of SCN5A-related diseases and offer the opportunity to investigate the secondary cellular consequences of SCN5A mutations such as the expression remodeling of other genes. This points out the potential role of these genes in the overall human phenotype. Finally, they constitute useful tools for addressing the role of genetic and environmental modifiers on cardiac electrical activity. PMID:22737129

  12. Hypoxia inducible factor-1α inhibition produced anti-allodynia effect and suppressed inflammatory cytokine production in early stage of mouse complex regional pain syndrome model.

    PubMed

    Hsiao, Hung-Tsung; Lin, Ya-Chi; Wang, Jeffrey Chi-Fei; Tsai, Yu-Chuan; Liu, Yen-Chin

    2016-03-01

    Complex regional pain syndrome (CRPS) is related to microcirculation impairment associated with tissue hypoxia and peripheral cytokine overproduction in the affected limb. Previous studies suggest that the pathogenesis involves hypoxia inducible factor-1α (HIF-1α) and exaggerated regional inflammatory response. 1-methylpropyl 2-imidazolyl disulfide (PX-12) acts as the thioredoxin-1 (Trx-1) inhibitor and decreases the level of HIF-1α, and can rapidly be metabolized for Trx-1 redox inactivation. This study hypothesized that PX-12 can decrease the cytokine production for nociceptive sensitization in the hypoxia-induced pain model. CD1 mice weighing around 30 g were used. The animal CRPS model was developed via the chronic post-ischaemic pain (CPIP) model. The model was induced by using O-rings on the ankles of the mice hind limbs to produce 3-h ischaemia-reperfusion injury on the paw. PX-12 (25 mg/kg, 5 mg/kg) was given through tail vein injection immediately after ischaemia. Animal behaviour was tested using the von Frey method for 7 days. Local paw skin tissue was harvest from three groups (control, 5 mg/kg, 25 mg/kg) 2 h after injection of PX-12. The protein expression of interleukin-1β (IL-1β) and HIF-1α was analysed with the Western blotting method. Mice significantly present an anti-allodynia effect in a dose-related manner after the PX-12 administration. Furthermore, PX-12 not only decreased the expression of HIF-1α but also decreased the expression of IL-1β over the injured palm. This study, therefore, shows the first evidence of the anti-allodynia effect of PX-12 in a CPIP animal model for pain behaviour. The study concluded that inhibition of HIF-1α may produce an analgesic effect and the associated suppression of inflammatory cytokine IL-1β in a CPIP model. PMID:26711019

  13. Mouse models for lung cancer.

    PubMed

    Kwon, Min-chul; Berns, Anton

    2013-04-01

    Lung cancer is a devastating disease and a major therapeutic burden with poor survival rates. It is responsible for 30% of all cancer deaths. Lung cancer is strongly associated with smoking, although some subtypes are also seen in non-smokers. Tumors in the latter group are mostly adenocarcinomas with many carrying mutations in the epidermal growth factor receptor (EGFR). Survival statistics of lung cancer are grim because of its late detection and frequent local and distal metastases. Although DNA sequence information from tumors has revealed a number of frequently occurring mutations, affecting well-known tumor suppressor genes and proto-oncogenes, many of the driver mutations remain ill defined. This is likely due to the involvement of numerous rather infrequently occurring driver mutations that are difficult to distinguish from the very large number of passenger mutations detected in smoking-related lung cancers. Therefore, experimental model systems are indispensable to validate putative driver lesions and to gain insight into their mechanisms of action. Whereas a large fraction of these analyzes can be performed in cell cultures in vitro, in many cases the consequences of the mutations have to be assessed in the context of an intact organism, as this is the context in which the Mendelian selection process of the tumorigenic process took place and the advantages of particular mutations become apparent. Current mouse models for cancer are very suitable for this as they permit mimicking many of the salient features of human tumors. The capacity to swiftly re-engineer complex sets of lesions found in human tumors in mice enables us to assess the contribution of defined combinations of lesions to distinct tumor characteristics such as metastatic behavior and response to therapy. In this review we will describe mouse models of lung cancer and how they are used to better understand the disease and how they are exploited to develop better intervention strategies

  14. Antioxidant treatment normalizes mitochondrial energetics and myocardial insulin sensitivity independently of changes in systemic metabolic homeostasis in a mouse model of the metabolic syndrome.

    PubMed

    Ilkun, Olesya; Wilde, Nicole; Tuinei, Joseph; Pires, Karla M P; Zhu, Yi; Bugger, Heiko; Soto, Jamie; Wayment, Benjamin; Olsen, Curtis; Litwin, Sheldon E; Abel, E Dale

    2015-08-01

    Cardiac dysfunction in obesity is associated with mitochondrial dysfunction, oxidative stress and altered insulin sensitivity. Whether oxidative stress directly contributes to myocardial insulin resistance remains to be determined. This study tested the hypothesis that ROS scavenging will improve mitochondrial function and insulin sensitivity in the hearts of rodent models with varying degrees of insulin resistance and hyperglycemia. The catalytic antioxidant MnTBAP was administered to the uncoupling protein-diphtheria toxin A (UCP-DTA) mouse model of insulin resistance (IR) and obesity, at early and late time points in the evolution of IR, and to db/db mice with severe obesity and type-two diabetes. Mitochondrial function was measured in saponin-permeabilized cardiac fibers. Aconitase activity and hydrogen peroxide emission were measured in isolated mitochondria. Insulin-stimulated glucose oxidation, glycolysis and fatty acid oxidation rates were measured in isolated working hearts, and 2-deoxyglucose uptake was measured in isolated cardiomyocytes. Four weeks of MnTBAP attenuated glucose intolerance in 13-week-old UCP-DTA mice but was without effect in 24-week-old UCP-DTA mice and in db/db mice. Despite the absence of improvement in the systemic metabolic milieu, MnTBAP reversed cardiac mitochondrial oxidative stress and improved mitochondrial bioenergetics by increasing ATP generation and reducing mitochondrial uncoupling in all models. MnTBAP also improved myocardial insulin mediated glucose metabolism in 13 and 24-week-old UCP-DTA mice. Pharmacological ROS scavenging improves myocardial energy metabolism and insulin responsiveness in obesity and type 2 diabetes via direct effects that might be independent of changes in systemic metabolism. PMID:26004364

  15. Discovery and characterization of spontaneous mouse models of craniofacial dysmorphology.

    PubMed

    Palmer, Kristina; Fairfield, Heather; Borgeia, Suhaib; Curtain, Michelle; Hassan, Mohamed G; Dionne, Louise; Yong Karst, Son; Coombs, Harold; Bronson, Roderick T; Reinholdt, Laura G; Bergstrom, David E; Donahue, Leah Rae; Cox, Timothy C; Murray, Stephen A

    2016-07-15

    Craniofacial abnormalities are among the most common features of human genetic syndromes and disorders. The etiology of these conditions is often complex, influenced by both genetic context and the environment. Frequently, craniofacial abnormalities present as part of a syndrome with clear comorbid phenotypes, providing additional insight into mechanisms of the causative gene or pathway. The mouse has been a key tool in our understanding of the genetic mechanisms of craniofacial development and disease, and can provide excellent models for human craniofacial abnormalities. While powerful genetic engineering tools in the mouse have contributed significantly our understanding of craniofacial development and dysmorphology, forward genetic approaches provide an unbiased means to identify new genes and pathways. Moreover, spontaneous mutations can occur on any number of genetic backgrounds, potentially revealing critical genes that require a specific genetic context. Here we report discovery and phenotyping of 43 craniofacial mouse models, derived primarily from a screen for spontaneous mutations in production colonies at the Jackson Laboratory. We identify the causative gene for 33 lines, including novel genes in pathways not previously connected to craniofacial development, and novel alleles of known genes that present with unique phenotypes. Together with our detailed characterization, this work provides a valuable gene discovery resource for the craniofacial community, and a rich source of mouse models for further investigation. PMID:26234751

  16. Mouse models of DNA polymerases.

    PubMed

    Menezes, Miriam R; Sweasy, Joann B

    2012-12-01

    In 1956, Arthur Kornberg discovered the mechanism of the biological synthesis of DNA and was awarded the Nobel Prize in Physiology or Medicine in 1959 for this contribution, which included the isolation and characterization of Escherichia coli DNA polymerase I. Now there are 15 known DNA polymerases in mammalian cells that belong to four different families. These DNA polymerases function in many different cellular processes including DNA replication, DNA repair, and damage tolerance. Several biochemical and cell biological studies have provoked a further investigation of DNA polymerase function using mouse models in which polymerase genes have been altered using gene-targeting techniques. The phenotypes of mice harboring mutant alleles reveal the prominent role of DNA polymerases in embryogenesis, prevention of premature aging, and cancer suppression. PMID:23001998

  17. Mouse model of intracerebellar haemorrhage.

    PubMed

    Tijjani Salihu, Abubakar; Muthuraju, Sangu; Aziz Mohamed Yusoff, Abdul; Ahmad, Farizan; Zulkifli Mustafa, Mohd; Jaafar, Hasnan; Idris, Zamzuri; Rahman Izaini Ghani, Abdul; Malin Abdullah, Jafri

    2016-10-01

    The present study aimed to investigate the behavior and neuronal morphological changes in the perihaemorrhagic tissue of the mouse intracerebellar haemorrhage experimental model. Adult male Swiss albino mice were stereotactically infused with collagenase type VII (0.4U/μl of saline) unilaterally in to the cerebellum, following anaesthesia. Motor deficits were assessed using open field and composite score for evaluating the mouse model of cerebellar ataxia at 1, 3, 7, 14 and 21 days after collagenase infusion. The animals were sacrificed at the same time interval for evaluation of perihaematomal neuronal degeneration using haematoxylin and eosin staining and Annexin V-FITC/Propidium iodide assay. At the end of the study, it was found that infusion of 0.4U collagenase produces significant locomotor and ataxic deficit in the mice especially within the first week post surgery, and that this gradually improved within three weeks. Neuronal degeneration evident by cytoplasmic shrinkage and nuclear pyknosis was observed at the perihaematomal area after one day; especially at 3 and 7 days post haemorrhage. By 21 days, both the haematoma and degenerating neurons in the perihaematomal area were phagocytosed and the remaining neuronal cells around the scar tissue appeared normal. Moreover, Annexin-V/propidium iodide-positive cells were observed at the perihaematomal area at 3 and 7 days implying that the neurons likely die via apoptosis. It was concluded that a population of potentially salvageable neurons exist in the perihaematomal area after cerebellar haemorrhage throughout a wide time window that could be amenable to treatment. PMID:27327104

  18. Autosomal dominant frontonasal dysplasia (atypical Greig syndrome): Lessons from the Xt mutant mouse

    SciTech Connect

    Cunningham, M.L.; Nunes, M.E.

    1994-09-01

    Greig syndrome is the autosomal dominant association of mild hypertelorism, variable polysyndactyly, and normal intelligence. Several families have been found to have translocations or deletions of 7p13 interrupting the normal expression of GLI3 (a zinc finger, DNA binding, transcription repressor). Recently, a mutation in the mouse homologue of GLI3 was found in the extra-toes mutant mouse (Xt). The phenotypic features of this mouse model include mild hypertelorism, postaxial polydactyly of the forelimbs, preaxial polydactyly of the hindlimbs, and variable tibial hemimelia. The homozygous mutant Xt/Xt have severe frontonasal dysplasia (FND), polysyndactyly of fore-and hindlimbs and invariable tibial hemimelia. We have recently evaluated a child with severe (type D) frontonasal dysplasia, fifth finger camptodactyly, preaxial polydactyly of one foot, and ispilateral tibial hemimelia. His father was born with a bifid nose, broad columnella, broad feet, and a two centimeter leg length discrepancy. The paternal grandmother of the proband is phenotypically normal; however, her fraternal twin died at birth with severe facial anomalies. The paternal great-grandmother of the proband is phenotypically normal however her niece was born with moderate ocular hypertelorism. This pedigree is suggestive of an autosomal dominant form of frontonasal dysplasia with variable expressivity. The phenotypic features of our case more closely resemble the Xt mouse than the previously defined features of Greig syndrome in humans. This suggests that a mutation in GLI3 may be responsible for FND in this family. We are currently using polymorphic dinucleotide repeat markers flanking GLI3 in a attempt to demonstrate linkage in this pedigree. Demonstration of a GLI3 mutation in this family would broaden our view of the spectrum of phenotypes possible in Greig syndrome and could provide insight into genotype/phenotype correlation in FND.

  19. Mouse Models of Rare Craniofacial Disorders.

    PubMed

    Achilleos, Annita; Trainor, Paul A

    2015-01-01

    A rare disease is defined as a condition that affects less than 1 in 2000 individuals. Currently more than 7000 rare diseases have been documented, and most are thought to be of genetic origin. Rare diseases primarily affect children, and congenital craniofacial syndromes and disorders constitute a significant proportion of rare diseases, with over 700 having been described to date. Modeling craniofacial disorders in animal models has been instrumental in uncovering the etiology and pathogenesis of numerous conditions and in some cases has even led to potential therapeutic avenues for their prevention. In this chapter, we focus primarily on two general classes of rare disorders, ribosomopathies and ciliopathies, and the surprising finding that the disruption of fundamental, global processes can result in tissue-specific craniofacial defects. In addition, we discuss recent advances in understanding the pathogenesis of an extremely rare and specific craniofacial condition known as syngnathia, based on the first mouse models for this condition. Approximately 1% of all babies are born with a minor or major developmental anomaly, and individuals suffering from rare diseases deserve the same quality of treatment and care and attention to their disease as other patients. PMID:26589934

  20. Mouse Models of Diabetic Neuropathy

    PubMed Central

    Sullivan, Kelli A.; Hayes, John M.; Wiggin, Timothy D.; Backus, Carey; Oh, Sang Su; Lentz, Stephen I.; Brosius, Frank; Feldman, Eva L.

    2007-01-01

    Diabetic neuropathy (DN) is a debilitating complication of type 1 and type 2 diabetes. Rodent models of DN do not fully replicate the pathology observed in human patients. We examined DN in streptozotocin (STZ)-induced [B6] and spontaneous type 1 diabetes [B6Ins2Akita] and spontaneous type 2 diabetes [B6-db/db, BKS-db/db]. DN was defined using the criteria of the Animal Models of Diabetic Complications Consortium (http://www.amdcc.org). Despite persistent hyperglycemia, the STZ-treated B6 and B6Ins2Akita mice were resistant to the development of DN. In contrast, DN developed in both type 2 diabetes models: the B6-db/db and BKS-db/db mice. The persistence of hyperglycemia and development of DN in the B6-db/db mice required an increased fat diet while the BKS-db/db mice developed severe DN and remained hyperglycemic on standard mouse chow. Our data support the hypothesis that genetic background and diet influence the development of DN and should be considered when developing new models of DN. PMID:17804249

  1. Delivery of the 7-dehydrocholesterol reductase gene to the central nervous system using adeno-associated virus vector in a mouse model of Smith-Lemli-Opitz Syndrome

    PubMed Central

    Pasta, Saloni; Akhile, Omoye; Tabron, Dorothy; Ting, Flora; Shackleton, Cedric; Watson, Gordon

    2015-01-01

    Smith Lemli Opitz syndrome (SLOS) is an inherited malformation and mental retardation metabolic disorder with no cure. Mutations in the last enzyme of the cholesterol biosynthetic pathway, 7-dehydrocholesterol reductase (DHCR7), lead to cholesterol insufficiency and accumulation of its dehyrdocholesterol precursors, and contribute to its pathogenesis. The central nervous system (CNS) constitutes a major pathophysiological component of this disorder and remains unamenable to dietary cholesterol therapy due to the impenetrability of the blood brain barrier (BBB). The goal of this study was to restore sterol homeostasis in the CNS. To bypass the BBB, gene therapy using an adeno-associated virus (AAV-8) vector carrying a functional copy of the DHCR7 gene was administered by intrathecal (IT) injection directly into the cerebrospinal fluid of newborn mice. Two months post-treatment, vector DNA and DHCR7 expression was observed in the brain and a corresponding improvement of sterol levels seen in the brain and spinal cord. Interestingly, sterol levels in the peripheral nervous system also showed a similar improvement. This study shows that IT gene therapy can have a positive biochemical effect on sterol homeostasis in the central and peripheral nervous systems in a SLOS animal model. A single dose delivered three days after birth had a sustained effect into adulthood, eight weeks post-treatment. These observations pave the way for further studies to understand the effect of biochemical improvement of sterol levels on neuronal function, to provide a greater understanding of neuronal cholesterol homeostasis, and to develop potential therapies. PMID:26347274

  2. Principal Component Analysis of the Effects of Environmental Enrichment and (-)-epigallocatechin-3-gallate on Age-Associated Learning Deficits in a Mouse Model of Down Syndrome

    PubMed Central

    Catuara-Solarz, Silvina; Espinosa-Carrasco, Jose; Erb, Ionas; Langohr, Klaus; Notredame, Cedric; Gonzalez, Juan R.; Dierssen, Mara

    2015-01-01

    Down syndrome (DS) individuals present increased risk for Alzheimer's disease (AD) neuropathology and AD-type dementia. Here, we investigated the use of green tea extracts containing (-)-epigallocatechin-3-gallate (EGCG), as co-adjuvant to enhance the effects of environmental enrichment (EE) in Ts65Dn mice, a segmental trisomy model of DS that partially mimics DS/AD pathology, at the age of initiation of cognitive decline. Classical repeated measures ANOVA showed that combined EE-EGCG treatment was more efficient than EE or EGCG alone to improve specific spatial learning related variables. Using principal component analysis (PCA) we found that several spatial learning parameters contributed similarly to a first PC and explained a large proportion of the variance among groups, thus representing a composite learning measure. This PC1 revealed that EGCG or EE alone had no significant effect. However, combined EE-EGCG significantly ameliorated learning alterations of middle age Ts65Dn mice. Interestingly, PCA revealed an increased variability along learning sessions with good and poor learners in Ts65Dn, and this stratification did not disappear upon treatments. Our results suggest that combining EE and EGCG represents a viable therapeutic approach for amelioration of age-related cognitive decline in DS, although its efficacy may vary across individuals. PMID:26696850

  3. Principal Component Analysis of the Effects of Environmental Enrichment and (-)-epigallocatechin-3-gallate on Age-Associated Learning Deficits in a Mouse Model of Down Syndrome.

    PubMed

    Catuara-Solarz, Silvina; Espinosa-Carrasco, Jose; Erb, Ionas; Langohr, Klaus; Notredame, Cedric; Gonzalez, Juan R; Dierssen, Mara

    2015-01-01

    Down syndrome (DS) individuals present increased risk for Alzheimer's disease (AD) neuropathology and AD-type dementia. Here, we investigated the use of green tea extracts containing (-)-epigallocatechin-3-gallate (EGCG), as co-adjuvant to enhance the effects of environmental enrichment (EE) in Ts65Dn mice, a segmental trisomy model of DS that partially mimics DS/AD pathology, at the age of initiation of cognitive decline. Classical repeated measures ANOVA showed that combined EE-EGCG treatment was more efficient than EE or EGCG alone to improve specific spatial learning related variables. Using principal component analysis (PCA) we found that several spatial learning parameters contributed similarly to a first PC and explained a large proportion of the variance among groups, thus representing a composite learning measure. This PC1 revealed that EGCG or EE alone had no significant effect. However, combined EE-EGCG significantly ameliorated learning alterations of middle age Ts65Dn mice. Interestingly, PCA revealed an increased variability along learning sessions with good and poor learners in Ts65Dn, and this stratification did not disappear upon treatments. Our results suggest that combining EE and EGCG represents a viable therapeutic approach for amelioration of age-related cognitive decline in DS, although its efficacy may vary across individuals. PMID:26696850

  4. Mouse Models for Filovirus Infections

    PubMed Central

    Bradfute, Steven B.; Warfield, Kelly L.; Bray, Mike

    2012-01-01

    The filoviruses marburg- and ebolaviruses can cause severe hemorrhagic fever (HF) in humans and nonhuman primates. Because many cases have occurred in geographical areas lacking a medical research infrastructure, most studies of the pathogenesis of filoviral HF, and all efforts to develop drugs and vaccines, have been carried out in biocontainment laboratories in non-endemic countries, using nonhuman primates (NHPs), guinea pigs and mice as animal models. NHPs appear to closely mirror filoviral HF in humans (based on limited clinical data), but only small numbers may be used in carefully regulated experiments; much research is therefore done in rodents. Because of their availability in large numbers and the existence of a wealth of reagents for biochemical and immunological testing, mice have become the preferred small animal model for filovirus research. Since the first experiments following the initial 1967 marburgvirus outbreak, wild-type or mouse-adapted viruses have been tested in immunocompetent or immunodeficient mice. In this paper, we review how these types of studies have been used to investigate the pathogenesis of filoviral disease, identify immune responses to infection and evaluate antiviral drugs and vaccines. We also discuss the strengths and weaknesses of murine models for filovirus research, and identify important questions for further study. PMID:23170168

  5. Mouse models of membranous nephropathy: the road less travelled by.

    PubMed

    Borza, Dorin-Bogdan; Zhang, Jun-Jun; Beck, Laurence H; Meyer-Schwesinger, Catherine; Luo, Wentian

    2013-01-01

    Membranous nephropathy (MN) is a major cause of idiopathic nephrotic syndrome in adults, often progressing to end-stage kidney disease. The disease is mediated by IgG antibodies that form subepithelial immune complexes upon binding to antigens expressed by podocytes or planted in the subepithelial space. Subsequent activation of the complement cascade, podocyte injury by the membrane attack complex and the expansion of the glomerular basement membrane cause proteinuria and nephrotic syndrome. The blueprint for our current understanding of the pathogenic mechanisms of MN has largely been provided by studies in rat Heymann nephritis, an excellent animal model that closely replicates human disease. However, further progress in this area has been hindered by the lack of robust mouse models of MN that can leverage the power of genetic approaches for mechanistic studies. This critical barrier has recently been overcome by the development of new mouse models that faithfully recapitulate the clinical and morphologic hallmarks of human MN. In these mouse models, subepithelial ICs mediating proteinuria and nephrotic syndrome are induced by injection of cationized bovine serum albumin, by passive transfer of heterologous anti-podocyte antibodies, or by active immunization with the NC1 domain of α3(IV) collagen. These mouse models of MN will be instrumental for addressing unsolved questions about the basic pathomechanisms of MN and also for preclinical studies of novel therapeutics. We anticipate that the new knowledge to be gained from these studies will eventually translate into much needed novel mechanism-based therapies for MN, more effective, more specific, and less toxic. PMID:23885331

  6. Mouse models of membranous nephropathy: the road less travelled by

    PubMed Central

    Borza, Dorin-Bogdan; Zhang, Jun-Jun; Beck, Laurence H; Meyer-Schwesinger, Catherine; Luo, Wentian

    2013-01-01

    Membranous nephropathy (MN) is a major cause of idiopathic nephrotic syndrome in adults, often progressing to end-stage kidney disease. The disease is mediated by IgG antibodies that form subepithelial immune complexes upon binding to antigens expressed by podocytes or planted in the subepithelial space. Subsequent activation of the complement cascade, podocyte injury by the membrane attack complex and the expansion of the glomerular basement membrane cause proteinuria and nephrotic syndrome. The blueprint for our current understanding of the pathogenic mechanisms of MN has largely been provided by studies in rat Heymann nephritis, an excellent animal model that closely replicates human disease. However, further progress in this area has been hindered by the lack of robust mouse models of MN that can leverage the power of genetic approaches for mechanistic studies. This critical barrier has recently been overcome by the development of new mouse models that faithfully recapitulate the clinical and morphologic hallmarks of human MN. In these mouse models, subepithelial ICs mediating proteinuria and nephrotic syndrome are induced by injection of cationized bovine serum albumin, by passive transfer of heterologous anti-podocyte antibodies, or by active immunization with the NC1 domain of α3(IV) collagen. These mouse models of MN will be instrumental for addressing unsolved questions about the basic pathomechanisms of MN and also for preclinical studies of novel therapeutics. We anticipate that the new knowledge to be gained from these studies will eventually translate into much needed novel mechanism-based therapies for MN, more effective, more specific, and less toxic. PMID:23885331

  7. CD40 Ligand Deficient C57BL/6 Mouse Is a Potential Surrogate Model of Human X-Linked Hyper IgM (X-HIGM) Syndrome for Characterizing Immune Responses against Pathogens

    PubMed Central

    Lopez-Saucedo, Catalina; Bernal-Reynaga, Rodolfo; Zayas-Jahuey, Jesus; Galindo-Gomez, Silvia; Shibayama, Mineko; Garcia-Galvez, Carlos; Estrada-Parra, Sergio; Estrada-Garcia, Teresa

    2015-01-01

    Individuals with X-HIGM syndrome fail to express functional CD40 ligand; consequently they cannot mount effective protective antibody responses against pathogenic bacteria. We evaluated, compared, and characterized the humoral immune response of wild type (WT) and C57-CD40L deficient (C57-CD40L−/−) mice infected with Citrobacter rodentium. Basal serum isotype levels were similar for IgM and IgG3 among mice, while total IgG and IgG2b concentrations were significantly lower in C57-CD40L−/− mice compared with WT. Essentially IgG1 and IgG2c levels were detectable only in WT mice. C57-CD40L−/− animals, orally inoculated with 2 × 109 CFU, presented several clinical manifestations since the second week of infection and eventually died. In contrast at this time point no clinical manifestations were observed among C57-CD40L−/− mice infected with 1 × 107 CFU. Infection was subclinical in WT mice inoculated with either bacterial dose. The serum samples from infected mice (1 × 107 CFU), collected at day 14 after infection, had similar C. rodentium-specific IgM titres. Although C57-CD40L−/− animals had lower IgG and IgG2b titres than WT mice, C57-CD40L−/− mice sera displayed complement-mediated bactericidal activity against C. rodentium. C. rodentium-infected C57-CD40L−/− mice are capable of producing antibodies that are protective. C57-CD40L−/− mouse is a useful surrogate model of X-HIGM syndrome for studying immune responses elicited against pathogens. PMID:26064940

  8. Restoration of Mecp2 expression in GABAergic neurons is sufficient to rescue multiple disease features in a mouse model of Rett syndrome.

    PubMed

    Ure, Kerstin; Lu, Hui; Wang, Wei; Ito-Ishida, Aya; Wu, Zhenyu; He, Ling-Jie; Sztainberg, Yehezkel; Chen, Wu; Tang, Jianrong; Zoghbi, Huda Y

    2016-01-01

    The postnatal neurodevelopmental disorder Rett syndrome, caused by mutations in MECP2, produces a diverse array of symptoms, including loss of language, motor, and social skills and the development of hand stereotypies, anxiety, tremor, ataxia, respiratory dysrhythmias, and seizures. Surprisingly, despite the diversity of these features, we have found that deleting Mecp2 only from GABAergic inhibitory neurons in mice replicates most of this phenotype. Here we show that genetically restoring Mecp2 expression only in GABAergic neurons of male Mecp2 null mice enhanced inhibitory signaling, extended lifespan, and rescued ataxia, apraxia, and social abnormalities but did not rescue tremor or anxiety. Female Mecp2(+/-) mice showed a less dramatic but still substantial rescue. These findings highlight the critical regulatory role of GABAergic neurons in certain behaviors and suggest that modulating the excitatory/inhibitory balance through GABAergic neurons could prove a viable therapeutic option in Rett syndrome. PMID:27328321

  9. Melatonin receptors: latest insights from mouse models

    PubMed Central

    Tosini, Gianluca; Owino, Sharon; Guillame, Jean-Luc; Jockers, Ralf

    2014-01-01

    Summary Melatonin, the neuro-hormone synthesized during the night, has recently seen an unexpected extension of its functional implications towards type 2 diabetes development, visual functions, sleep disturbances and depression. Transgenic mouse models were instrumental for the establishment of the link between melatonin and these major human diseases. Most of the actions of melatonin are mediated by two types of G protein-coupled receptors, named MT1 and MT2, which are expressed in many different organs and tissues. Understanding the pharmacology and function of mouse MT1 and MT2 receptors, including MT1/MT2 heteromers, will be of crucial importance to evaluate the relevance of these mouse models for future therapeutic developments. This review will critically discuss these aspects, and give some perspectives including the generation of new mouse models. PMID:24903552

  10. Chronic Pancreatitis and Systemic Inflammatory Response Syndrome Prevent Impact of Chemotherapy with Gemcitabine in a Genetically Engineered Mouse Model of Pancreatic Cancer12

    PubMed Central

    Knoop, Richard F.; Sparn, Moritz; Waldmann, Jens; Plassmeier, Lars; Bartsch, Detlef K.; Lauth, Matthias; Hudemann, Christoph; Fendrich, Volker

    2014-01-01

    BACKGROUND AND AIMS BACKGROUND AND AIMSGemcitabine is the standard therapy for patients with pancreatic cancer with metastatic disease. Patients with metastatic pancreatic cancer presenting with increased values of C-reactive protein do not respond to gemcitabine. So far, no studies have evaluated the correlation between chronic pancreatitis, systemic inflammatory response syndrome, and the loss of chemotherapeutic benefit. METHODS Pdx-1-Cre;LSL-KrasG12D/+;LSL-Trp53R172H/+ mice were assigned into four groups: 1) Sixteen animals received a daily intraperitoneal injection of caerulein from their ninth week of life on. 2) Sixteen mice were additionally given gemcitabine. 3) Twelve animals received gemcitabine only. 4) Saline-treated control group. Furthermore, human Paca44 pancreatic ductal adenocarcinoma cells were seeded and cultured in 0.5% FBS containing growth medium plus/minus 1 μM gemcitabine plus/minus recombinant human interleukin (IL)-6. RESULTS Induced systemic inflammatory response syndrome and a mild chronic pancreatitis diminished the beneficial effects of gemcitabine upon median overall survival. In median, the monogemcitabine group survived 191 days, whereas the caerulein-mono group survived 114, the control group 121, and the caerulein gemcitabine group 127 days (P < .05). In vitro, the induction of STAT3 phosphorylation by recombinant human IL-6 promoted pancreatic ductal adenocarcinoma cell survival during gemcitabine treatment. CONCLUSION We could demonstrate for the first time that an improvement in median overall survival with gemcitabine is significantly abolished by a persistent mild chronic pancreatitis and a systemic inflammatory response syndrome. In particular, the inflammation biomarkers C-reactive protein, IL-6, and IL-1α could indicate the prognostic benefit of gemcitabine chemotherapy and should now be tested in prospective patient-controlled trials. PMID:24953430

  11. Loss of functional A-type potassium channels in the dendrites of CA1 pyramidal neurons from a mouse model of fragile X syndrome.

    PubMed

    Routh, Brandy N; Johnston, Daniel; Brager, Darrin H

    2013-12-11

    Despite the critical importance of voltage-gated ion channels in neurons, very little is known about their functional properties in Fragile X syndrome: the most common form of inherited cognitive impairment. Using three complementary approaches, we investigated the physiological role of A-type K(+) currents (I(KA)) in hippocampal CA1 pyramidal neurons from fmr1-/y mice. Direct measurement of I(KA) using cell-attached patch-clamp recordings revealed that there was significantly less I(KA) in the dendrites of CA1 neurons from fmr1-/y mice. Interestingly, the midpoint of activation for A-type K(+) channels was hyperpolarized for fmr1-/y neurons compared with wild-type, which might partially compensate for the lower current density. Because of the rapid time course for recovery from steady-state inactivation, the dendritic A-type K(+) current in CA1 neurons from both wild-type and fmr1-/y mice is likely mediated by K(V)4 containing channels. The net effect of the differences in I(KA) was that back-propagating action potentials had larger amplitudes producing greater calcium influx in the distal dendrites of fmr1-/y neurons. Furthermore, CA1 pyramidal neurons from fmr1-/y mice had a lower threshold for LTP induction. These data suggest that loss of I(KA) in hippocampal neurons may contribute to dendritic pathophysiology in Fragile X syndrome. PMID:24336711

  12. 7-Dehydrocholesterol–dependent proteolysis of HMG-CoA reductase suppresses sterol biosynthesis in a mouse model of Smith-Lemli-Opitz/RSH syndrome

    PubMed Central

    Fitzky, Barbara U.; Moebius, Fabian F.; Asaoka, Hitoshi; Waage-Baudet, Heather; Xu, Liwen; Xu, Guorong; Maeda, Nobuyo; Kluckman, Kimberly; Hiller, Sylvia; Yu, Hongwei; Batta, Ashok K.; Shefer, Sarah; Chen, Thomas; Salen, Gerald; Sulik, Kathleen; Simoni, Robert D.; Ness, Gene C.; Glossmann, Hartmut; Patel, Shailendra B.; Tint, G.S.

    2001-01-01

    Smith-Lemli-Opitz/RSH syndrome (SLOS), a relatively common birth-defect mental-retardation syndrome, is caused by mutations in DHCR7, whose product catalyzes an obligate step in cholesterol biosynthesis, the conversion of 7-dehydrocholesterol to cholesterol. A null mutation in the murine Dhcr7 causes an identical biochemical defect to that seen in SLOS, including markedly reduced tissue cholesterol and total sterol levels, and 30- to 40-fold elevated concentrations of 7-dehydrocholesterol. Prenatal lethality was not noted, but newborn homozygotes breathed with difficulty, did not suckle, and died soon after birth with immature lungs, enlarged bladders, and, frequently, cleft palates. Despite reduced sterol concentrations in Dhcr7–/– mice, mRNA levels for 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase, the rate-controlling enzyme for sterol biosynthesis, the LDL receptor, and SREBP-2 appeared neither elevated nor repressed. In contrast to mRNA, protein levels and activities of HMG-CoA reductase were markedly reduced. Consistent with this finding, 7-dehydrocholesterol accelerates proteolysis of HMG-CoA reductase while sparing other key proteins. These results demonstrate that in mice without Dhcr7 activity, accumulated 7-dehydrocholesterol suppresses sterol biosynthesis posttranslationally. This effect might exacerbate abnormal development in SLOS by increasing the fetal cholesterol deficiency. PMID:11560960

  13. Restoration of Mecp2 expression in GABAergic neurons is sufficient to rescue multiple disease features in a mouse model of Rett syndrome

    PubMed Central

    Ure, Kerstin; Lu, Hui; Wang, Wei; Ito-Ishida, Aya; Wu, Zhenyu; He, Ling-jie; Sztainberg, Yehezkel; Chen, Wu; Tang, Jianrong; Zoghbi, Huda Y

    2016-01-01

    The postnatal neurodevelopmental disorder Rett syndrome, caused by mutations in MECP2, produces a diverse array of symptoms, including loss of language, motor, and social skills and the development of hand stereotypies, anxiety, tremor, ataxia, respiratory dysrhythmias, and seizures. Surprisingly, despite the diversity of these features, we have found that deleting Mecp2 only from GABAergic inhibitory neurons in mice replicates most of this phenotype. Here we show that genetically restoring Mecp2 expression only in GABAergic neurons of male Mecp2 null mice enhanced inhibitory signaling, extended lifespan, and rescued ataxia, apraxia, and social abnormalities but did not rescue tremor or anxiety. Female Mecp2+/- mice showed a less dramatic but still substantial rescue. These findings highlight the critical regulatory role of GABAergic neurons in certain behaviors and suggest that modulating the excitatory/inhibitory balance through GABAergic neurons could prove a viable therapeutic option in Rett syndrome. DOI: http://dx.doi.org/10.7554/eLife.14198.001 PMID:27328321

  14. β2-Adrenergic receptor agonist ameliorates phenotypes and corrects microRNA-mediated IGF1 deficits in a mouse model of Rett syndrome.

    PubMed

    Mellios, Nikolaos; Woodson, Jonathan; Garcia, Rodrigo I; Crawford, Benjamin; Sharma, Jitendra; Sheridan, Steven D; Haggarty, Stephen J; Sur, Mriganka

    2014-07-01

    Rett syndrome is a severe childhood onset neurodevelopmental disorder caused by mutations in methyl-CpG-binding protein 2 (MECP2), with known disturbances in catecholamine synthesis. Here, we show that treatment with the β2-adrenergic receptor agonist clenbuterol increases survival, rescues abnormalities in respiratory function and social recognition, and improves motor coordination in young male Mecp2-null (Mecp2(-/y)) mice. Importantly, we demonstrate that short-term treatment with clenbuterol in older symptomatic female heterozygous (Mecp2(-/+)) mice rescues respiratory, cognitive, and motor coordination deficits, and induces an anxiolytic effect. In addition, we reveal abnormalities in a microRNA-mediated pathway, downstream of brain-derived neurotrophic factor that affects insulin-like growth factor 1 (IGF1) expression in Mecp2(-/y) mice, and show that treatment with clenbuterol restores the observed molecular alterations. Finally, cotreatment with clenbuterol and recombinant human IGF1 results in additional increases in survival in male null mice. Collectively, our data support a role for IGF1 and other growth factor deficits as an underlying mechanism of Rett syndrome and introduce β2-adrenergic receptor agonists as potential therapeutic agents for the treatment of the disorder. PMID:24958851

  15. Reduction of α1GABAA receptor mediated by tyrosine kinase C (PKC) phosphorylation in a mouse model of fragile X syndrome

    PubMed Central

    Zhao, Weidong; Wang, Jiaqin; Song, Shunyi; Li, Fang; Yuan, Fangfang

    2015-01-01

    Fragile X syndrome (FXS) caused by lack of fragile X mental retardation protein (Fmr1) is the most common cause of inherited intellectual disability and characterized by many cognitive disturbances like attention deficit, autistic behavior, and audiogenic seizure and have region-specific altered expression of some gamma-aminobutyric acid (GABAA) receptor subunits. Quantitative real-time polymerase chain reaction and western blot experiments were performed in the cultured cortical neurons and forebrain obtained from wild-type (WT) and Fmr1 KO mice demonstrate the reduction in the expression of α1 gamma-aminobutyric acid (α1GABAA) receptor, phospho-α1GABAA receptor, PKC and phosphor-PKC in Fmr1 KO mice comparing with WT mice, both in vivo and in vitro. Furthermore, we found that the phosphorylation of the α1GABAA receptor was mediated by PKC. Our results elucidate that the lower phosphorylation of the α1GABAA receptor mediated by PKC neutralizes the seizure-promoting effects in Fmr1 KO mice and point to the potential therapeutic targets of α1GABAA agonists for the treatment of fragile X syndrome. PMID:26550246

  16. Non-homologous end joining mediated DNA repair is impaired in the NUP98-HOXD13 mouse model for myelodysplastic syndrome

    PubMed Central

    Puthiyaveetil, Abdul Gafoor; Reilly, Christopher M.; Pardee, Timothy S.; Caudell, David L.

    2016-01-01

    Chromosomal translocations typically impair cell differentiation and often require secondary mutations for malignant transformation. However, the role of a primary translocation in the development of collaborating mutations is debatable. To delineate the role of leukemic translocation NUP98-HOXD13 (NHD13) in secondary mutagenesis, DNA break and repair mechanisms in stimulated mouse B lymphocytes expressing NHD13 were analyzed. Our results showed significantly reduced expression of non-homologous end joining (NHEJ)-mediated DNA repair genes, DNA Pkcs, DNA ligase4, and Xrcc4 leading to cell cycle arrest at G2/M phase. Our results showed that expression of NHD13 fusion gene resulted in impaired NHEJ-mediated DNA break repair. PMID:23131583

  17. Multimodal, multidimensional models of mouse brain.

    PubMed

    Mackenzie-Graham, Allan J; Lee, Erh-Fang; Dinov, Ivo D; Yuan, Heng; Jacobs, Russell E; Toga, Arthur W

    2007-01-01

    Naturally occurring mutants and genetically manipulated strains of mice are widely used to model a variety of human diseases. Atlases are an invaluable aid in understanding the impact of such manipulations by providing a standard for comparison and to facilitate the integration of anatomic, genetic, and physiologic observations from multiple subjects and experiments. We have developed digital atlases of the C57BL/6J mouse brain (adult and neonate) as comprehensive frameworks for storing and accessing the myriad types of information about the mouse brain. Along with raw and annotated images, these contain database management systems and a set of tools for comparing information from different techniques and different animals. Each atlas establishes a canonical representation of the mouse brain and provides the tools for the manipulation and analysis of new data. We describe both these atlases and discuss how they may be put to use in organizing and analyzing data from mouse models of epilepsy. PMID:17767578

  18. MeCP2-Mediated Transcription Repression in the Basolateral Amygdala May Underlie Heightened Anxiety in a Mouse Model of Rett Syndrome

    PubMed Central

    Adachi, Megumi; Autry, Anita E.; Covington, Herb E.; Monteggia, Lisa M.

    2010-01-01

    Rett syndrome (RTT) is an X-linked neurodevelopmental disorder that results from loss of function mutations in the methyl-CpG binding protein 2 (MECP2) gene. Using viral-mediated basolateral amygdala (BLA)-specific deletion of Mecp2 in mice, we show that intact Mecp2 function is required for normal anxiety behavior as well as some types of learning and memory. To examine whether these behavioral deficits are the result of impaired transcriptional repression, because Mecp2 is believed to act as a transcriptional repressor in complex with histone deacetylases (HDACs), we infused a HDAC inhibitor chronically into the BLA of wild-type mice. We found that HDAC inhibition produces behavioral deficits similar to those observed after the deletion of Mecp2 in the BLA. These results suggest a key role for Mecp2 as a transcriptional repressor in the BLA in mediating behavioral features of RTT. PMID:19339616

  19. Pathology of Mouse Models of Accelerated Aging.

    PubMed

    Harkema, L; Youssef, S A; de Bruin, A

    2016-03-01

    Progeroid mouse models display phenotypes in multiple organ systems that suggest premature aging and resemble features of natural aging of both mice and humans. The prospect of a significant increase in the global elderly population within the next decades has led to the emergence of "geroscience," which aims at elucidating the molecular mechanisms involved in aging. Progeroid mouse models are frequently used in geroscience as they provide insight into the molecular mechanisms that are involved in the highly complex process of natural aging. This review provides an overview of the most commonly reported nonneoplastic macroscopic and microscopic pathologic findings in progeroid mouse models (eg, osteoporosis, osteoarthritis, degenerative joint disease, intervertebral disc degeneration, kyphosis, sarcopenia, cutaneous atrophy, wound healing, hair loss, alopecia, lymphoid atrophy, cataract, corneal endothelial dystrophy, retinal degenerative diseases, and vascular remodeling). Furthermore, several shortcomings in pathologic analysis and descriptions of these models are discussed. Progeroid mouse models are valuable models for aging, but thorough knowledge of both the mouse strain background and the progeria-related phenotype is required to guide interpretation and translation of the pathology data. PMID:26864891

  20. N-ethyl-N-nitrosourea-induced null mutation at the mouse Car-2 locus: an animal model for human carbonic anhydrase II deficiency syndrome.

    PubMed Central

    Lewis, S E; Erickson, R P; Barnett, L B; Venta, P J; Tashian, R E

    1988-01-01

    Electrophoretic screening of (C57BL/6J x DBA/2J)F1 progeny of male mice treated with N-ethyl-N-nitrosourea revealed a mouse that lacked the paternal carbonic anhydrase II (CA II). Breeding tests showed that this trait was heritable and due to a null mutation at the Car-2 locus on chromosome 3. Like humans with the same inherited enzyme defect, animals homozygous for the new null allele are runted and have renal tubular acidosis. However, the prominent osteopetrosis found in humans with CA II deficiency could not be detected even in very old homozygous null mice. A molecular analysis of the deficient mice shows that the mutant gene is not deleted and is transcribed. The CA II protein, which is normally expressed in most tissues, could not be detected by immunodiffusion analysis in any tissues of the CA II-deficient mice, suggesting a nonsense or a missense mutation at the Car-2 locus. Images PMID:3126501

  1. Peripheral Neuropathy in Mouse Models of Diabetes.

    PubMed

    Jolivalt, Corinne G; Frizzi, Katie E; Guernsey, Lucie; Marquez, Alex; Ochoa, Joseline; Rodriguez, Maria; Calcutt, Nigel A

    2016-01-01

    Peripheral neuropathy is a frequent complication of chronic diabetes that most commonly presents as a distal degenerative polyneuropathy with sensory loss. Around 20% to 30% of such patients may also experience neuropathic pain. The underlying pathogenic mechanisms are uncertain, and therapeutic options are limited. Rodent models of diabetes have been used for more than 40 years to study neuropathy and evaluate potential therapies. For much of this period, streptozotocin-diabetic rats were the model of choice. The emergence of new technologies that allow relatively cheap and routine manipulations of the mouse genome has prompted increased use of mouse models of diabetes to study neuropathy. In this article, we describe the commonly used mouse models of type 1 and type 2 diabetes, and provide protocols to phenotype the structural, functional, and behavioral indices of peripheral neuropathy, with a particular emphasis on assays pertinent to the human condition. © 2016 by John Wiley & Sons, Inc. PMID:27584552

  2. Rescue of deficient amygdala tonic γ-aminobutyric acidergic currents in the Fmr(-/y) mouse model of fragile X syndrome by a novel γ-aminobutyric acid type A receptor-positive allosteric modulator.

    PubMed

    Martin, Brandon S; Martinez-Botella, Gabriel; Loya, Carlos M; Salituro, Francesco G; Robichaud, Albert J; Huntsman, Molly M; Ackley, Mike A; Doherty, James J; Corbin, Joshua G

    2016-06-01

    Alterations in the ratio of excitatory to inhibitory transmission are emerging as a common component of many nervous system disorders, including autism spectrum disorders (ASDs). Tonic γ-aminobutyric acidergic (GABAergic) transmission provided by peri- and extrasynaptic GABA type A (GABAA ) receptors powerfully controls neuronal excitability and plasticity and, therefore, provides a rational therapeutic target for normalizing hyperexcitable networks across a variety of disorders, including ASDs. Our previous studies revealed tonic GABAergic deficits in principal excitatory neurons in the basolateral amygdala (BLA) in the Fmr1(-/y) knockout (KO) mouse model fragile X syndrome. To correct amygdala deficits in tonic GABAergic neurotransmission in Fmr1(-/y) KO mice, we developed a novel positive allosteric modulator of GABAA receptors, SGE-872, based on endogenously active neurosteroids. This study shows that SGE-872 is nearly as potent and twice as efficacious for positively modulating GABAA receptors as its parent molecule, allopregnanolone. Furthermore, at submicromolar concentrations (≤1 μM), SGE-872 is selective for tonic, extrasynaptic α4β3δ-containing GABAA receptors over typical synaptic α1β2γ2 receptors. We further find that SGE-872 strikingly rescues the tonic GABAergic transmission deficit in principal excitatory neurons in the Fmr1(-/y) KO BLA, a structure heavily implicated in the neuropathology of ASDs. Therefore, the potent and selective action of SGE-872 on tonic GABAA receptors containing α4 subunits may represent a novel and highly useful therapeutic avenue for ASDs and related disorders involving hyperexcitability of neuronal networks. © 2015 Wiley Periodicals, Inc. PMID:26308557

  3. Mouse Models of Uncomplicated and Fatal Malaria

    PubMed Central

    Huang, Brian W.; Pearman, Emily; Kim, Charles C.

    2015-01-01

    Mouse models have demonstrated utility in delineating the mechanisms underlying many aspects of malaria immunology and physiology. The most common mouse models of malaria employ the rodent-specific parasite species Plasmodium berghei, P. yoelii, and P. chabaudi, which elicit distinct pathologies and immune responses and are used to model different manifestations of human disease. In vitro culture methods are not well developed for rodent Plasmodium parasites, which thus require in vivo maintenance. Moreover, physiologically relevant immunological processes are best studied in vivo. Here, we detail the processes of infecting mice with Plasmodium, maintaining the parasite in vivo, and monitoring parasite levels and health parameters throughout infection. PMID:26236758

  4. Repeated Administrations of Human Umbilical Cord Blood Cells Improve Disease Outcomes in a Mouse Model of Sanfilippo Syndrome Type III B.

    PubMed

    Willing, Alison E; Garbuzova-Davis, Svitlana N; Zayko, Olga; Derasari, Hiranya M; Rawls, Ashley E; James, Chris R; Mervis, Ron F; Sanberg, Cyndy D; Kuzmin-Nichols, Nicole; Sanberg, Paul R

    2013-12-30

    Sanfilippo syndrome type III B (MPS III B) is an inherited disorder characterized by a deficiency of ?-N-acetylglucosaminidase (Naglu) enzyme leading to accumulation of heparan sulfate in lysosomes and severe neurological deficits. We have previously shown that a single administration of human umbilical cord mononuclear cells (hUCB MNC) into Nagluknockout mice decreased behavioral abnormalities and tissue pathology. In this study, we tested whether repeated doses of hUCB MNCs would be more beneficial than a single dose of cells. Naglumice at 3 months of age were randomly assigned to either a Media only group, or one of three hUCB MNC treatment groups - single low dose (3x10(6) cells), single high dose (1.8x10(7) cells) or multiple doses (3x10(6) cells monthly for 6 months) delivered intravenously (i.v.); cyclosporine was injected i.p. to immune suppress the mice for the duration of the study. An additional control group of wild type mice was also used. We measured anxiety in an open field test and cognition inactive avoidance test prior to treatment and then at monthly intervals for 6 months. hUCB MNCs restored normal anxiety-like behavior in these mice (p < 0.001). The repeated cell administrations also restored hippocampal cytoarchitecture, protected the dendritic tree, decreased GM3 ganglioside accumulation and decreased microglial activation, particularly in hippocampus and cortex. These data suggest that the neuroprotective effect of hUCB MNCs can be enhanced by repeated cell administrations. PMID:24380668

  5. Dysregulated co-stimulatory molecule expression in a Sjögren's syndrome mouse model with potential implications by microRNA-146a.

    PubMed

    Gauna, Adrienne E; Park, Yun-Jong; Nayar, Gautam; Onate, Marelys; Jin, Jun-o; Stewart, Carol M; Yu, Qing; Cha, Seunghee

    2015-12-01

    Sjögren's syndrome (SjS) is an autoimmune condition that primarily affects salivary and lacrimal glands, causing loss of secretion. We have previously shown that microRNA-146a (miR-146a) is over-expressed in the salivary glands and peripheral blood mononuclear cells (PBMC) of SjS-prone mice (C57BL/6.NOD-Aec1Aec2, B6DC) and in PBMC of SjS patients. The purpose of this research was to identify a target molecule of miR-146a and identify subpopulations of cells affected by altered miR-146a in the salivary glands of SjS-prone mice. In silico analyses identified costimulatory molecule CD80 as a potential target of miR-146a. Luciferase assay of the human CD80 3'untranslated region demonstrated miR-146a directly inhibited CD80 protein expression as indicated by reduced luciferase reporter expression and an examination of B6DC salivary glands revealed a reduction in CD80 protein. More interestingly, the specific reduction in CD80 protein was detected from the salivary gland epithelial cell population and in interstitial dendritic cells in the glands as well. The reduction in CD80 protein levels in salivary gland epithelial cells were negatively associated with elevated miR-146a expression. Therefore, this study provides the first indication that salivary gland epithelial cells may be critically involved in SjS progression by altering CD86:CD80 protein ratio in response to miR-146a upregulation. PMID:26505653

  6. Repeated administrations of human umbilical cord blood cells improve disease outcomes in a mouse model of Sanfilippo syndrome type III B.

    PubMed

    Willing, Alison E; Garbuzova-Davis, Svitlana N; Zayko, Olga; Derasari, Hiranya M; Rawls, Ashley E; James, Chris R; Mervis, Ron F; Sanberg, Cyndy D; Kuzmin-Nichols, Nicole; Sanberg, Paul R

    2014-01-01

    Sanfilippo syndrome type III B (MPS III B) is an inherited disorder characterized by a deficiency of α-N-acetylglucosaminidase (Naglu) enzyme leading to accumulation of heparan sulfate in lysosomes and severe neurological deficits. We have previously shown that a single administration of human umbilical cord mononuclear cells (hUCB MNCs) into Naglu knockout mice decreased behavioral abnormalities and tissue pathology. In this study, we tested whether repeated doses of hUCB MNCs would be more beneficial than a single dose of cells. Naglu mice at 3 months of age were randomly assigned to either a Media-only group or one of three hUCB MNC treatment groups--single low dose (3 × 10(6) cells), single high dose (1.8 × 10(7) cells), or multiple doses (3 × 10(6) cells monthly for 6 months) delivered intravenously; cyclosporine was injected intraperitoneally to immune suppress the mice for the duration of the study. An additional control group of wild-type mice was also used. We measured anxiety in an open field test and cognition in an active avoidance test prior to treatment and then at monthly intervals for 6 months. hUCB MNCs restored normal anxiety-like behavior in these mice (p < 0.001). The repeated cell administrations also restored hippocampal cytoarchitecture, protected the dendritic tree, decreased GM3 ganglioside accumulation, and decreased microglial activation, particularly in the hippocampus and cortex. These data suggest that the neuroprotective effect of hUCB MNCs can be enhanced by repeated cell administrations. PMID:25565636

  7. 7, 8-Dihydroxyflavone induces synapse expression of AMPA GluA1 and ameliorates cognitive and spine abnormalities in a mouse model of fragile X syndrome.

    PubMed

    Tian, Mi; Zeng, Yan; Hu, Yilan; Yuan, Xiuxue; Liu, Shumin; Li, Jie; Lu, Pan; Sun, Yao; Gao, Lei; Fu, Daan; Li, Yi; Wang, Shasha; McClintock, Shawn M

    2015-02-01

    Fragile X syndrome (FXS) is characterized by immature dendritic spine architectures and cognitive impairment. 7, 8-Dihydroxyflavone (7, 8-DHF) has recently been identified as a high affinity tropomyosin receptor kinase B (TrkB) agonist. The purpose of this paper was to examine the utility of 7, 8-DHF as an effective pharmacotherapeutic agent that targets dendritic pathology and cognitive impairments in FXS mutant. We synthesized pharmacologic, behavioral, and biochemical approaches to examine the effects of 7, 8-DHF on spatial and fear memory functions, and morphological spine abnormalities in fragile X mental retardation 1 (Fmr1) gene knock-out mice. The study found that 4 weeks of treatment with 7, 8-DHF improved spatial and fear memory, and ameliorated morphological spine abnormalities including the number and elongation of spines in the hippocampus and amygdala. Further mechanism analysis revealed that 7, 8-DHF enhanced the expression of alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) GluA1 receptor, but reduced the normal levels of GluA2 at the synapses in Fmr1. Potentially related to drug-induced changes in AMPA receptor subunits, 7, 8-DHF at the synapses led to phosphorylation of specific serine sites on subunits Ser818 and Ser813 of GluA1, and Ser880 of GluA2, as well as phosphorylation of TrkB, calcium/calmodulin-dependent protein kinase II, and protein kinase C. However, 7, 8-DHF neither affected behavioral performance nor increased TrkB phosphorylation in WT mice, which suggested that it had FXS-specific correcting effect. Altogether, these results demonstrated that 7, 8-DHF improved learning and memory, and reduced abnormalities in spine morphology, thus providing a potential pharmacotherapeutic strategy for FXS. PMID:25229717

  8. Citrobacter rodentium mouse model of bacterial infection.

    PubMed

    Crepin, Valerie F; Collins, James W; Habibzay, Maryam; Frankel, Gad

    2016-10-01

    Infection of mice with Citrobacter rodentium is a robust model to study bacterial pathogenesis, mucosal immunology, the health benefits of probiotics and the role of the microbiota during infection. C. rodentium was first isolated by Barthold from an outbreak of mouse diarrhea in Yale University in 1972 and was 'rediscovered' by Falkow and Schauer in 1993. Since then the use of the model has proliferated, and it is now the gold standard for studying virulence of the closely related human pathogens enteropathogenic and enterohemorrhagic Escherichia coli (EPEC and EHEC, respectively). Here we provide a detailed protocol for various applications of the model, including bacterial growth, site-directed mutagenesis, mouse inoculation (from cultured cells and after cohabitation), monitoring of bacterial colonization, tissue extraction and analysis, immune responses, probiotic treatment and microbiota analysis. The main protocol, from mouse infection to clearance and analysis of tissues and host responses, takes ∼5 weeks to complete. PMID:27606775

  9. A BDNF loop-domain mimetic acutely reverses spontaneous apneas and respiratory abnormalities during behavioral arousal in a mouse model of Rett syndrome

    PubMed Central

    Kron, Miriam; Lang, Min; Adams, Ian T.; Sceniak, Michael; Longo, Frank; Katz, David M.

    2014-01-01

    Reduced levels of brain-derived neurotrophic factor (BDNF) are thought to contribute to the pathophysiology of Rett syndrome (RTT), a severe neurodevelopmental disorder caused by loss-of-function mutations in the gene encoding methyl-CpG-binding protein 2 (MeCP2). In Mecp2 mutant mice, BDNF deficits have been associated with breathing abnormalities, a core feature of RTT, as well as with synaptic hyperexcitability within the brainstem respiratory network. Application of BDNF can reverse hyperexcitability in acute brainstem slices from Mecp2-null mice, suggesting that therapies targeting BDNF or its receptor, TrkB, could be effective at acute reversal of respiratory abnormalities in RTT. Therefore, we examined the ability of LM22A-4, a small-molecule BDNF loop-domain mimetic and TrkB partial agonist, to modulate synaptic excitability within respiratory cell groups in the brainstem nucleus tractus solitarius (nTS) and to acutely reverse abnormalities in breathing at rest and during behavioral arousal in Mecp2 mutants. Patch-clamp recordings in Mecp2-null brainstem slices demonstrated that LM22A-4 decreases excitability at primary afferent synapses in the nTS by reducing the amplitude of evoked excitatory postsynaptic currents and the frequency of spontaneous and miniature excitatory postsynaptic currents. In vivo, acute treatment of Mecp2-null and -heterozygous mutants with LM22A-4 completely eliminated spontaneous apneas in resting animals, without sedation. Moreover, we demonstrate that respiratory dysregulation during behavioral arousal, a feature of human RTT, is also reversed in Mecp2 mutants by acute treatment with LM22A-4. Together, these data support the hypothesis that reduced BDNF signaling and respiratory dysfunction in RTT are linked, and establish the proof-of-concept that treatment with a small-molecule structural mimetic of a BDNF loop domain and a TrkB partial agonist can acutely reverse abnormal breathing at rest and in response to behavioral arousal

  10. Genetic dissection of Down syndrome-associated congenital heart defects using a new mouse mapping panel

    PubMed Central

    Lana-Elola, Eva; Watson-Scales, Sheona; Slender, Amy; Gibbins, Dorota; Martineau, Alexandrine; Douglas, Charlotte; Mohun, Timothy; Fisher, Elizabeth MC; Tybulewicz, Victor LJ

    2016-01-01

    Down syndrome (DS), caused by trisomy of human chromosome 21 (Hsa21), is the most common cause of congenital heart defects (CHD), yet the genetic and mechanistic causes of these defects remain unknown. To identify dosage-sensitive genes that cause DS phenotypes, including CHD, we used chromosome engineering to generate a mapping panel of 7 mouse strains with partial trisomies of regions of mouse chromosome 16 orthologous to Hsa21. Using high-resolution episcopic microscopy and three-dimensional modeling we show that these strains accurately model DS CHD. Systematic analysis of the 7 strains identified a minimal critical region sufficient to cause CHD when present in 3 copies, and showed that it contained at least two dosage-sensitive loci. Furthermore, two of these new strains model a specific subtype of atrio-ventricular septal defects with exclusive ventricular shunting and demonstrate that, contrary to current hypotheses, these CHD are not due to failure in formation of the dorsal mesenchymal protrusion. DOI: http://dx.doi.org/10.7554/eLife.11614.001 PMID:26765563

  11. [Clinical and Biological Character in Mouse Models for Middle East Respiratory Syndrome Generated by Transduction with Different Doses of DPP4 Molecule].

    PubMed

    Yao, Yanfeng; Lan, Jiaming; Li, Fengdi; Niu, Peihua; Yu, Pin; Lu Shuai; Bao, Linlin; Tan, Wenjie; Qin, Chuan

    2015-11-01

    In this study, we evaluated the difference ot biological characteristics in the MERS-CoV infected mice model in prior to transduction with different dosage of human DPP4. Firstly, we transduced different dosage of DPP4 (high or low) into mice, and then challenged them with MERS-CoV in order to establish the model. After establishment of mice model, we observed the clinical signs of disease, virus replication, immunopathogenesis and antibody response. The results indicated that the infected mice showed typical pneumonia, virus replication, histological lesions, and neutralizing antibody production. Moreover, the high dosage group was superior to the low dosage group. Fourteen days after infection, the specific antibody to virus structural protein and neutralizing antibody were analyzed, the high dosage group induced higher level antibody. In summary, the MERS-CoV infected mice model were established prior transduction with DPP4, and the level of DPP4 influenced the clinical signs of disease, virus replication and antibody response in this model. PMID:26951002

  12. Effects of verbenalin on prostatitis mouse model

    PubMed Central

    Miao, Mingsan; Guo, Lin; Yan, Xiaoli; Wang, Tan; Li, Zuming

    2015-01-01

    The aim of this study was to observe the treatment characteristics of verbenalin on a prostatitis mouse model. Give Xiaozhiling injection in the prostate locally to make a prostatitis mouse model. High, medium and low doses of verbenalin were each given to different mouse groups. The amount of water was determined in 14th, 28th. The number of white cells and lecithin corpuscle density in prostatic fluid were determined. Morphological changes in the prostate, testis, epididymis and kidney were detected. Compared with the model control group, the mice treated with high, medium and low doses of verbenalin had significantly increased amounts of water, and prostate white blood cell count and prostate volume density (Vv) were decreased significantly, the density of lecithin corpuscle score increased, and pathologic prostatitis changes were significantly reduced. Pathological change in the testis was significantly reduced and the change in the epididymis was obviously reduced. The thymic cortex thickness and the number of lymphocytes increased significantly and could reduce the renal pathological changes in potential. Verbenalin has a good therapeutic effect on the prostatitis mouse model. PMID:26858560

  13. Genetically engineered mouse models for lung cancer.

    PubMed

    Kwak, I; Tsai, S Y; DeMayo, F J

    2004-01-01

    The lung is a complex organ consisting of numerous cell types that function to ensure sufficient gas exchange to oxygenate the blood. In order to accomplish this function, the lung must be exposed to the external environment and at the same time maintain a homeostatic balance between its function in gas exchange and the maintenance of inflammatory balance. During the past two decades, as molecular methodologies have evolved with the sequencing of entire genomes, the use of in vivo models to elucidate the molecular mechanisms involved in pulmonary physiology and disease have increased. The mouse has emerged as a potent model to investigate pulmonary physiology due to the explosion in molecular methods that now allow for the developmental and tissue-specific regulation of gene transcription. Initial efforts to manipulate gene expression in the mouse genome resulted in the generation of transgenic mice characterized by the constitutive expression of a specific gene and knockout mice characterized by the ablation of a specific gene. The utility of these original mouse models was limited, in many cases, by phenotypes resulting in embryonic or neonatal lethality that prevented analysis of the impact of the genetic manipulation on pulmonary biology. Second-generation transgenic mouse models employ multiple strategies that can either activate or silence gene expression thereby providing extensive temporal and spatial control of the experimental parameters of gene expression. These highly regulated mouse models are intended to serve as a foundation for further investigation of the molecular basis of human disease such as tumorigenesis. This review describes the principles, progress, and application of systems that are currently employed in the conditional regulation of gene expression in the investigation of lung cancer. PMID:14977417

  14. Chromosomal protein HMG-14 gene maps to the Down syndrome region of human chromosome 21 and is overexpressed in mouse trisomy 16

    SciTech Connect

    Pash, J.; Popescu, N.; Matocha, M.; Rapoport, S.; Bustin, M. )

    1990-05-01

    The gene for human high-mobility-group (HMG) chromosomal protein HMG-14 is located in region 21q22.3, a region associated with the pathogenesis of Down syndrome, one of the most prevalent human birth defects. The expression of this gene is analyzed in mouse embryos that are trisomic in chromosome 16 and are considered to be an animal model for Down syndrome. RNA blot-hybridization analysis and detailed analysis of HMG-14 protein levels indicate that mouse trisomy 16 embryos have approximately 1.5 times more HMG-14 mRNA and protein than their normal littermates, suggesting a direct gene dosage effect. The HMG-14 gene may be an additional marker for the Down syndrome. Chromosomal protein HMG-14 is a nucleosomal binding protein that may confer distinct properties to the chromatin structure of transcriptionally active genes and therefore may be a contributing factor in the etiology of the syndrome.

  15. Time course of cytokine upregulation in the lacrimal gland and presence of autoantibodies in a predisposed mouse model of Sjögren’s Syndrome: the influence of sex hormones and genetic background

    PubMed Central

    Czerwinski, Stefanie; Mostafa, Safinaz; Rowan, Vanessa Seamon; Azzarolo, Ana Maria

    2014-01-01

    Sjögren’s Syndrome (SS) is a chronic, inflammatory autoimmune disease characterized by lacrimal gland lymphocytic infiltration and epithelial cell death, as well as by the presence of serum autoantibodies. Although the symptoms of this syndrome are well characterized, patients are not diagnosed until 5–10 years into disease progression; furthermore, the early series of events leading to the initiation of SS are not well understood. In order to better understand the early events of the disease, we have been using ovariectomized (OVX) NOD.B10.H2b mice as a genetically predisposed model of SS. Previously, we have shown that removal of ovarian hormones through ovariectomy accelerated the symptoms of this disease, and in early events of SS in the lacrimal glands, lymphocytic infiltration preceded acinar cell apoptosis. To further elucidate the earlier events of this disease in the SS animal model, we investigated the expression and concentration of pro-inflammatory cytokines in the lacrimal glands as well as the presence of autoantibodies in both lacrimal glands and serum. Six weeks old NOD.B10.H2b and C57BL/10 control mice were either sham-operated, OVX, OVX and treated with 17β-estradiol (E2), or OVX and treated with dihydrotestosterone (DHT). Lacrimal glands were collected at 3, 7, 21, and 30 days after surgery and analyzed for cytokines IL-1β, TNF-α, IFN-γ, IL-10, and IL-4 gene expression by using quantitative RT-PCR and for cytokine levels using ELISA. Furthermore, anti-Ro/SSA and anti-La/SSB autoantibodies were measured in the serum and lacrimal glands supernatants using ELISA. The results of this study showed that OVX caused a significant increase in the expression and levels of the cytokines IL-1β, TNF-α, and IL-4 in the lacrimal glands of the NOD.B10.H2b mice starting at 3 days after OVX, while a significant increase of IL-10 gene expression and levels was observed only at later experimental time points. A small but significant increase in the

  16. Mouse Models of Neurofibromatosis 1 and 21

    PubMed Central

    Gutmann, David H; Giovannini, Marco

    2002-01-01

    Abstract The neurofibromatoses represent two of the most common inherited tumor predisposition syndromes affecting the nervous system. Individuals with neurofibromatosis 1 (NF1) are prone to the development of astrocytomas and peripheral nerve sheath tumors whereas those affected with neurofibromatosis 2 (NF2) develop schwannomas and meningiomas. The development of traditional homozygous knockout mice has provided insights into the roles of the NF1 and NF2 genes during development and in differentiation, but has been less instructive regarding the contribution of NF1 and NF2 dysfunction to the pathogenesis of specific benign and malignant tumors. Recent progress employing novel mouse targeting strategies has begun to illuminate the roles of the NF1 and NF2 gene products in the molecular pathogenesis of NF-associated tumors. PMID:12082543

  17. Clinicopathological characterization of mouse models of melanoma.

    PubMed

    Ferguson, Blake; Soyer, H Peter; Walker, Graeme J

    2015-01-01

    Mouse models of melanoma have proven invaluable in the delineation of key molecular events involved in disease progression in humans and provide potential preclinical models for therapeutic testing (Damsky and Bosenberg, Pigment Cell Melanoma Res 25(4):404-405, 2012; Walker et al., Pigment Cell Melanoma Res 24(6):1158-1176, 2011). Here we concentrate on the clinicopathological analysis of melanocytic tumors. PMID:25636472

  18. ALIGNING MOUSE MODELS OF ASTHMA TO HUMAN ENDOTYPES OF DISEASE

    PubMed Central

    Martin, Rebecca A; Hodgkins, Samantha R; Dixon, Anne E; Poynter, Matthew E

    2014-01-01

    Substantial gains in understanding the pathophysiologic mechanisms underlying asthma have been made using preclinical mouse models. However, because asthma is a complex, heterogeneous syndrome that is rarely due to a single allergen and that often presents in the absence of atopy, few of the promising therapeutics that demonstrated effectiveness in mouse models have translated into new treatments for patients. This has resulted in an urgent need to characterize Th2-low, noneosinophilic subsets of asthma, to study models that are resistant to conventional treatments such as corticosteroids, and to develop therapies targeting patients with severe disease. Classifying asthma based on underlying pathophysiologic mechanisms, known as endotyping, offers a stratified approach for the development of new therapies for asthma. In preclinical research, new models of asthma are being utilized that more closely resemble the clinical features of different asthma endotypes, including the presence of IL-17 and a Th17 response, a biomarker of severe disease. These models utilize more physiologically relevant sensitizing agents, exacerbating factors, and allergens, as well as incorporate time points that better reflect the natural history and chronicity of clinical asthma. Importantly, some models better represent nonclassical asthma endotypes that facilitate the study of non-Th2 driven pathology and resemble the complex nature of clinical asthma, including corticosteroid resistance. Placing mouse asthma models into the context of human asthma endotypes will afford a more relevant approach to the understanding of pathophysiological mechanisms of disease that will afford the development of new therapies for those asthmatics that remain difficult to treat. PMID:24811131

  19. A novel mouse model of creatine transporter deficiency

    PubMed Central

    Baroncelli, Laura; Alessandrì, Maria Grazia; Tola, Jonida; Putignano, Elena; Migliore, Martina; Amendola, Elena; Gross, Cornelius; Leuzzi, Vincenzo; Cioni, Giovanni; Pizzorusso, Tommaso

    2014-01-01

    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 behavioral disturbances, language and speech impairment ( OMIM #300352). CCDS1 is still an untreatable pathology that can be very invalidating for patients and caregivers. Only two murine models of CCDS1, one of which is an ubiquitous knockout mouse, are currently available to study the possible mechanisms underlying the pathologic phenotype of CCDS1 and to develop therapeutic strategies. Given the importance of validating phenotypes and efficacy of promising treatments in more than one mouse model we have generated a new murine model of CCDS1 obtained by ubiquitous deletion of 5-7 exons in the Slc6a8 gene. We showed a remarkable Cr depletion in the murine brain tissues and cognitive defects, thus resembling the key features of human CCDS1. These results confirm that CCDS1 can be well modeled in mice. This CrT −/y murine model will provide a new tool for increasing the relevance of preclinical studies to the human disease. PMID:25485098

  20. Mouse Model of Oropharyngeal Candidiasis

    PubMed Central

    Solis, Norma V.; Filler, Scott G.

    2013-01-01

    Oropharyngeal candidiasis is a frequent cause of morbidity in patients with defects in cell-mediated immunity or saliva production. Animal models of this infection are important for studying disease pathogenesis and evaluating vaccines and antifungal therapies. Here we describe a simple murine model of oropharyngeal candidiasis. Mice are rendered susceptible to oral infection by injection with cortisone acetate and then inoculated by placing a swab saturated with Candida albicans sublingually. This process results in a reproducible level of infection, the histopathology of which mimics that of pseudomembranous oropharyngeal candidiasis in patients. Using this model, data are obtained after 5–9 days of work. PMID:22402633

  1. Mouse models for core binding factor leukemia.

    PubMed

    Chin, D W L; Watanabe-Okochi, N; Wang, C Q; Tergaonkar, V; Osato, M

    2015-10-01

    RUNX1 and CBFB are among the most frequently mutated genes in human leukemias. Genetic alterations such as chromosomal translocations, copy number variations and point mutations have been widely reported to result in the malfunction of RUNX transcription factors. Leukemias arising from such alterations in RUNX family genes are collectively termed core binding factor (CBF) leukemias. Although adult CBF leukemias generally are considered a favorable risk group as compared with other forms of acute myeloid leukemia, the 5-year survival rate remains low. An improved understanding of the molecular mechanism for CBF leukemia is imperative to uncover novel treatment options. Over the years, retroviral transduction-transplantation assays and transgenic, knockin and knockout mouse models alone or in combination with mutagenesis have been used to study the roles of RUNX alterations in leukemogenesis. Although successful in inducing leukemia, the existing assays and models possess many inherent limitations. A CBF leukemia model which induces leukemia with complete penetrance and short latency would be ideal as a platform for drug discovery. Here, we summarize the currently available mouse models which have been utilized to study CBF leukemias, discuss the advantages and limitations of individual experimental systems, and propose suggestions for improvements of mouse models. PMID:26165235

  2. On Models and Mickey Mouse

    ERIC Educational Resources Information Center

    Petherbridge, Deanna

    2005-01-01

    The re-issue of a nineteenth-century French "Drawing Course" is the occasion for an examination of issues of "models of good practice" in current art teaching. These are listed as an expanded set of student-centred pedagogical paradigms, which embrace the forceful popular imagery of electronic games and comic strips. The formalist adaptations of…

  3. Mouse models for neural tube closure defects.

    PubMed

    Juriloff, D M; Harris, M J

    2000-04-12

    Neural tube closure defects (NTDs), in particular anencephaly and spina bifida, are common human birth defects (1 in 1000), their genetics is complex and their risk is reduced by periconceptional maternal folic acid supplementation. There are > 60 mouse mutants and strains with NTDs, many reported within the past 2 years. Not only are NTD mutations at loci widely heterogeneous in function, but also most of the mutants demonstrate variable low penetrance and some show complex inheritance patterns (e.g. SELH/Bc, Abl / Arg, Mena / Profilin1 ). In most of these mouse models, the NTDs are exencephaly (equivalent to anencephaly) or spina bifida or both, reflecting failure of neural fold elevation in well defined, mechanistically distinct elevation zones. NTD risk is reduced in various models by different maternal nutrient supplements, including folic acid ( Pax3, Cart1, Cd mutants), inositol ( ct ) and methionine ( Axd ). Lack of de novo methylation in embryos ( Dnmt3b -null) leads to NTD risk, and we suggest a potential link between methylation and the observed female excess among cranial NTDs in several models. Some surprising NTD mutants ( Gadd45a, Terc, Trp53 ) suggest that genes with a basic mitotic function also have a function specific to neural fold elevation. The genes mutated in several mouse NTD models involve actin regulation ( Abl/Arg, Macs, Mena/Profilin1, Mlp, Shrm, Vcl ), support the postulated key role of actin in neural fold elevation, and may be a good candidate pathway to search for human NTD genes. PMID:10767323

  4. Mouse models of human disease

    PubMed Central

    Perlman, Robert L.

    2016-01-01

    The use of mice as model organisms to study human biology is predicated on the genetic and physiological similarities between the species. Nonetheless, mice and humans have evolved in and become adapted to different environments and so, despite their phylogenetic relatedness, they have become very different organisms. Mice often respond to experimental interventions in ways that differ strikingly from humans. Mice are invaluable for studying biological processes that have been conserved during the evolution of the rodent and primate lineages and for investigating the developmental mechanisms by which the conserved mammalian genome gives rise to a variety of different species. Mice are less reliable as models of human disease, however, because the networks linking genes to disease are likely to differ between the two species. The use of mice in biomedical research needs to take account of the evolved differences as well as the similarities between mice and humans. PMID:27121451

  5. A vertical mouse and ergonomic mouse pads alter wrist position but do not reduce carpal tunnel pressure in patients with carpal tunnel syndrome.

    PubMed

    Schmid, Annina B; Kubler, Paul A; Johnston, Venerina; Coppieters, Michel W

    2015-03-01

    Non-neutral wrist positions and external pressure leading to increased carpal tunnel pressure during computer use have been associated with a heightened risk of carpal tunnel syndrome (CTS). This study investigated whether commonly used ergonomic devices reduce carpal tunnel pressure in patients with CTS. Carpal tunnel pressure was measured in twenty-one patients with CTS before, during and after a computer mouse task using a standard mouse, a vertical mouse, a gel mouse pad and a gliding palm support. Carpal tunnel pressure increased while operating a computer mouse. Although the vertical mouse significantly reduced ulnar deviation and the gel mouse pad and gliding palm support decreased wrist extension, none of the ergonomic devices reduced carpal tunnel pressure. The findings of this study do therefore not endorse a strong recommendation for or against any of the ergonomic devices commonly recommended for patients with CTS. Selection of ergonomic devices remains dependent on personal preference. PMID:25479984

  6. Criteria for Validating Mouse Models of Psychiatric Diseases

    PubMed Central

    Chadman, Kathryn K.; Yang, Mu; Crawley, Jacqueline N.

    2010-01-01

    Animal models of human diseases are in widespread use for biomedical research. Mouse models with a mutation in a single gene or multiple genes are excellent research tools for understanding the role of a specific gene in the etiology of a human genetic disease. Ideally, the mouse phenotypes will recapitulate the human phenotypes exactly. However, exact matches are rare, particularly in mouse models of neuropsychiatric disorders. This article summarizes the current strategies for optimizing the validity of a mouse model of a human brain dysfunction. We address the common question raised by molecular geneticists and clinical researchers in psychiatry, “what is a ‘good enough’ mouse model”? PMID:18484083

  7. Experimental photoallergic contact dermatitis: a mouse model

    SciTech Connect

    Maguire, H.C. Jr.; Kaidbey, K.

    1982-09-01

    We have induced photoallergic contact dermatitis in mice to 3,3',4',5 tetrachlorosalicylanilide (TCSA), chlorpromazine and 6-methylcoumarin. These compounds are known to produce photoallergic contact dermatitis in humans. The photoallergic contact dermatitis reaction in the mouse is immunologically specific viz. mice photosensitized to TCSA react, by photochallenge, to that compound and not to chlorpromazine, and conversely. The reaction requires UVA at both sensitization and challenge. It appears to be T-cell mediated in that it can be passively transferred to syngeneic mice by lymph node cells from actively sensitized mice, the histology of the reactions resembles that of classic allergic contact dermatitis in mice, challenge reactions are seen at 24 but not at 4 hr, and photoallergic contact dermatitis can be induced in B-cell deficient mice. The availability of a mouse model for the study of photo-ACD will facilitate the identification of pertinent control mechanisms and may aid in the management of the disease. It is likely that a bioassay for photoallergens of humans can be based on this mouse model.

  8. Dysfunctional cardiac mitochondrial bioenergetic, lipidomic, and signaling in a murine model of Barth syndrome[S

    PubMed Central

    Kiebish, Michael A.; Yang, Kui; Liu, Xinping; Mancuso, David J.; Guan, Shaoping; Zhao, Zhongdan; Sims, Harold F.; Cerqua, Rebekah; Cade, W. Todd; Han, Xianlin; Gross, Richard W.

    2013-01-01

    Barth syndrome is a complex metabolic disorder caused by mutations in the mitochondrial transacylase tafazzin. Recently, an inducible tafazzin shRNA knockdown mouse model was generated to deconvolute the complex bioenergetic phenotype of this disease. To investigate the underlying cause of hemodynamic dysfunction in Barth syndrome, we interrogated the cardiac structural and signaling lipidome of this mouse model as well as its myocardial bioenergetic phenotype. A decrease in the distribution of cardiolipin molecular species and robust increases in monolysocardiolipin and dilysocardiolipin were demonstrated. Additionally, the contents of choline and ethanolamine glycerophospholipid molecular species containing precursors for lipid signaling at the sn-2 position were altered. Lipidomic analyses revealed specific dysregulation of HETEs and prostanoids, as well as oxidized linoleic and docosahexaenoic metabolites. Bioenergetic interrogation uncovered differential substrate utilization as well as decreases in Complex III and V activities. Transgenic expression of cardiolipin synthase or iPLA2γ ablation in tafazzin-deficient mice did not rescue the observed phenotype. These results underscore the complex nature of alterations in cardiolipin metabolism mediated by tafazzin loss of function. Collectively, we identified specific lipidomic, bioenergetic, and signaling alterations in a murine model that parallel those of Barth syndrome thereby providing novel insights into the pathophysiology of this debilitating disease. PMID:23410936

  9. Recent female mouse models displaying advanced reproductive aging.

    PubMed

    Danilovich, Natalia; Ram Sairam, M

    2006-02-01

    Reproductive senescence occurs in all female mammals with resultant changes in numerous body functional systems and several important features may be species-specific. Those features that appear to parallel human menopause and aging include general similarity of hormone profiles across the menopausal transition, progression to cycle termination through irregular cycles, declining fertility with age, disturbances in thermogenesis, age-related gains in body weight, fat distribution and disposition towards metabolic syndrome. Structural and hormonal changes in the brain and ovary play a critical role in determining the onset of reproductive senescence. The short life span of rodents such as mice (compared to humans) and the ability to generate specific and timed gene deletions, provide powerful experimental paradigms to understand the molecular and functional changes that precede and follow the loss of reproductive capacity. In theory, any manipulation that compromises ovarian function either partly or totally would impact reproductive events at various levels followed by other dysfunctions. In this article, we provide an overview of three mouse models for the study of female reproductive aging. They are derived from different strategies and their age related phenotypes have been characterized to varying degrees. The follitropin receptor knockout (FORKO) mouse, in its null and haploinsufficient state as well as the dioxin/aryl hydrocarbon receptor (AhR) knockout mouse, serve as two examples of single gene deletions. A third model, using administration of a chemical toxicant such as 4-vinylcyclohexene diepoxide (VCD) in the adult state, produces ovarian deficiencies accompanied by aging changes. These will serve as useful alternatives to previously used radical ovariectomy in young adults. It is anticipated that these new models and more that will be forthcoming will extend opportunities to understand reproductive aging and resolve controversies that abound on issues

  10. Mouse Models of Anemia of Cancer

    PubMed Central

    Kim, Airie; Rivera, Seth; Shprung, Dana; Limbrick, Donald; Gabayan, Victoria; Nemeth, Elizabeta; Ganz, Tomas

    2014-01-01

    Anemia of cancer (AC) may contribute to cancer-related fatigue and impair quality of life. Improved understanding of the pathogenesis of AC could facilitate better treatment, but animal models to study AC are lacking. We characterized four syngeneic C57BL/6 mouse cancers that cause AC. Mice with two different rapidly-growing metastatic lung cancers developed the characteristic findings of anemia of inflammation (AI), with dramatically different degrees of anemia. Mice with rapidly-growing metastatic melanoma also developed a severe anemia by 14 days, with hematologic and inflammatory parameters similar to AI. Mice with a slow-growing peritoneal ovarian cancer developed an iron-deficiency anemia, likely secondary to chronically impaired nutrition and bleeding into the peritoneal cavity. Of the four models, hepcidin mRNA levels were increased only in the milder lung cancer model. Unlike in our model of systemic inflammation induced by heat-killed Brucella abortus, ablation of hepcidin in the ovarian cancer and the milder lung cancer mouse models did not affect the severity of anemia. Hepcidin-independent mechanisms play an important role in these murine models of AC. PMID:24681760

  11. Mouse models of cognitive disorders in trisomy 21: a review.

    PubMed

    Sérégaza, Zohra; Roubertoux, Pierre L; Jamon, Marc; Soumireu-Mourat, Bernard

    2006-05-01

    Trisomy 21 (TRS21) is the most frequent genetic cause of mental retardation. Although the presence of an extra copy of HSA21 is known to be at the origin of the syndrome, we do not know which 225 HSA21 genes have an effect on cognitive processes. Mouse models of TRS21 have been developed using syntenies between HSA21 and MMU16, MMU10 and MMU17. Available mouse models carry extra fragments of MMU16 or of HSA21 that cover all of HSA21 (chimeric HSA21) or MMU16 (Ts16); some carry large parts of MMU16 (Ts65Dn, Ts1Cje, Ms1Cje), while others have reduced contiguous fragments covering the D21S17-ETS2 region or single transfected genes. This offers a nest design strategy for deciphering cognitive (learning, memory and exploration) and associated brain abnormalities involving each of these chromosomal regions. This review confirms the crucial but not exclusive contribution of the D21S17-ETS2 region encompassing 16 genes to cognitive disorders. PMID:16523244

  12. Triheptanoin in acute mouse seizure models.

    PubMed

    Thomas, Nicola K; Willis, Sarah; Sweetman, Lawrence; Borges, Karin

    2012-05-01

    Triheptanoin, the triglyceride of heptanoate, is used to treat certain hereditary metabolic diseases in USA because of its anaplerotic potential. In two chronic mouse seizure models this clear tasteless oil was found to be reproducibly anticonvulsant. Here we investigated the effects of triheptanoin feeding in C3H and CD1 mice using standard acute seizure models. Feeding 30-40% triheptanoin (caloric intake) consistently elevated blood propionyl-carnitines, but inconsistent anticonvulsant effects were observed in the fluorothyl, pentylenetetrazole and 6Hz seizure models. A 2mA consistent increase in the maximal electroshock threshold was found after 3 weeks of 35% triheptanoin feeding (p=0.018). In summary, triheptanoin shows a unique anticonvulsant profile in seizure models, compared to other treatments that are in the clinic. Therefore, despite small and/or inconsistent effects of triheptanoin in acute seizure models, triheptanoin remains of interest as a potential add-on treatment for patients with medically refractory epilepsy. PMID:22260920

  13. Down syndrome as a model of DNA polymerase beta haploinsufficiency and accelerated aging.

    PubMed

    Patterson, David; Cabelof, Diane C

    2012-04-01

    Down syndrome is a condition of intellectual disability characterized by accelerated aging. As with other aging syndromes, evidence accumulated over the past several decades points to a DNA repair defect inherent in Down syndrome. This evidence has led us to suggest that Down syndrome results in reduced DNA base excision repair (BER) capacity, and that this contributes to the genomic instability and the aging phenotype of Down syndrome. We propose important roles for microRNA and/or folate metabolism and oxidative stress in the dysregulation of BER in Down syndrome. Further, we suggest these pathways are involved in the leukemogenesis of Down syndrome. We have reviewed the role of BER in the processing of oxidative stress, and the impact of folate depletion on BER capacity. Further, we have reviewed the role that loss of BER, specifically DNA polymerase beta, plays in accelerating the rate of aging. Like that seen in the DNA polymerase beta heterozygous mouse, the aging phenotype of Down syndrome is subtle, unlike the aging phenotypes seen in the classical progeroid syndromes and mouse models of aging. As such, Down syndrome may provide a model for elucidating some of the basic mechanisms of aging. PMID:22019846

  14. Esophageal Cancer: Insights From Mouse Models

    PubMed Central

    Tétreault, Marie-Pier

    2015-01-01

    Esophageal cancer is the eighth leading cause of cancer and the sixth most common cause of cancer-related death worldwide. Despite recent advances in the development of surgical techniques in combination with the use of radiotherapy and chemotherapy, the prognosis for esophageal cancer remains poor. The cellular and molecular mechanisms that drive the pathogenesis of esophageal cancer are still poorly understood. Hence, understanding these mechanisms is crucial to improving outcomes for patients with esophageal cancer. Mouse models constitute valuable tools for modeling human cancers and for the preclinical testing of therapeutic strategies in a manner not possible in human subjects. Mice are excellent models for studying human cancers because they are similar to humans at the physiological and molecular levels and because they have a shorter gestation time and life cycle. Moreover, a wide range of well-developed technologies for introducing genetic modifications into mice are currently available. In this review, we describe how different mouse models are used to study esophageal cancer. PMID:26380556

  15. A Chemical Mutagenesis Screen Identifies Mouse Models with ERG Defects.

    PubMed

    Charette, Jeremy R; Samuels, Ivy S; Yu, Minzhong; Stone, Lisa; Hicks, Wanda; Shi, Lan Ying; Krebs, Mark P; Naggert, Jürgen K; Nishina, Patsy M; Peachey, Neal S

    2016-01-01

    Mouse models provide important resources for many areas of vision research, pertaining to retinal development, retinal function and retinal disease. The Translational Vision Research Models (TVRM) program uses chemical mutagenesis to generate new mouse models for vision research. In this chapter, we report the identification of mouse models for Grm1, Grk1 and Lrit3. Each of these is characterized by a primary defect in the electroretinogram. All are available without restriction to the research community. PMID:26427409

  16. Mouse models of intestinal inflammation and cancer.

    PubMed

    Westbrook, Aya M; Szakmary, Akos; Schiestl, Robert H

    2016-09-01

    Chronic inflammation is strongly associated with approximately one-fifth of all human cancers. Arising from combinations of factors such as environmental exposures, diet, inherited gene polymorphisms, infections, or from dysfunctions of the immune response, chronic inflammation begins as an attempt of the body to remove injurious stimuli; however, over time, this results in continuous tissue destruction and promotion and maintenance of carcinogenesis. Here, we focus on intestinal inflammation and its associated cancers, a group of diseases on the rise and affecting millions of people worldwide. Intestinal inflammation can be widely grouped into inflammatory bowel diseases (ulcerative colitis and Crohn's disease) and celiac disease. Long-standing intestinal inflammation is associated with colorectal cancer and small-bowel adenocarcinoma, as well as extraintestinal manifestations, including lymphomas and autoimmune diseases. This article highlights potential mechanisms of pathogenesis in inflammatory bowel diseases and celiac disease, as well as those involved in the progression to associated cancers, most of which have been identified from studies utilizing mouse models of intestinal inflammation. Mouse models of intestinal inflammation can be widely grouped into chemically induced models; genetic models, which make up the bulk of the studied models; adoptive transfer models; and spontaneous models. Studies in these models have lead to the understanding that persistent antigen exposure in the intestinal lumen, in combination with loss of epithelial barrier function, and dysfunction and dysregulation of the innate and adaptive immune responses lead to chronic intestinal inflammation. Transcriptional changes in this environment leading to cell survival, hyperplasia, promotion of angiogenesis, persistent DNA damage, or insufficient repair of DNA damage due to an excess of proinflammatory mediators are then thought to lead to sustained malignant transformation. With

  17. Mouse Model of Coxiella burnetii Aerosolization.

    PubMed

    Melenotte, Cléa; Lepidi, Hubert; Nappez, Claude; Bechah, Yassina; Audoly, Gilles; Terras, Jérôme; Raoult, Didier; Brégeon, Fabienne

    2016-07-01

    Coxiella burnetii is mainly transmitted by aerosols and is responsible for multiple-organ lesions. Animal models have shown C. burnetii pathogenicity, but long-term outcomes still need to be clarified. We used a whole-body aerosol inhalation exposure system to mimic the natural route of infection in immunocompetent (BALB/c) and severe combined immunodeficient (SCID) mice. After an initial lung inoculum of 10(4) C. burnetii cells/lung, the outcome, serological response, hematological disorders, and deep organ lesions were described up to 3 months postinfection. C. burnetii-specific PCR, anti-C. burnetii immunohistochemistry, and fluorescent in situ hybridization (FISH) targeting C. burnetii-specific 16S rRNA completed the detection of the bacterium in the tissues. In BALB/c mice, a thrombocytopenia and lymphopenia were first observed, prior to evidence of C. burnetii replication. In all SCID mouse organs, DNA copies increased to higher levels over time than in BALB/c ones. Clinical signs of discomfort appeared in SCID mice, so follow-up had to be shortened to 2 months in this group. At this stage, all animals presented bone, cervical, and heart lesions. The presence of C. burnetii could be attested in situ for all organs sampled using immunohistochemistry and FISH. This mouse model described C. burnetii Nine Mile strain spread using aerosolization in a way that corroborates the pathogenicity of Q fever described in humans and completes previously published data in mouse models. C. burnetii infection occurring after aerosolization in mice thus seems to be a useful tool to compare the pathogenicity of different strains of C. burnetii. PMID:27160294

  18. PEGylated G-CSF (BBT-015), GM-CSF (BBT-007), and IL-11 (BBT-059) analogs enhance survival and hematopoietic cell recovery in a mouse model of the hematopoietic syndrome of the acute radiation syndrome.

    PubMed

    Plett, Paul Artur; Chua, Hui Lin; Sampson, Carol H; Katz, Barry P; Fam, Christine M; Anderson, Lana J; Cox, George N; Orschell, Christie M

    2014-01-01

    Hematopoietic growth factors (HGF) are recommended therapy for high dose radiation exposure, but unfavorable administration schedules requiring early and repeat dosing limit the logistical ease with which they can be used. In this report, using a previously described murine model of H-ARS, survival efficacy and effect on hematopoietic recovery of unique PEGylated HGF were investigated. The PEGylated-HGFs possess longer half-lives and more potent hematopoietic properties than corresponding non-PEGylated-HGFs. C57BL/6 mice underwent single dose lethal irradiation (7.76-8.72 Gy, Cs, 0.62-1.02 Gy min) and were treated with various dosing regimens of 0.1, 0.3, and 1.0 mg kg of analogs of human PEG-G-CSF, murine PEG-GM-CSF, or human PEG-IL-11. Mice were administered one of the HGF analogs at 24-28 h post irradiation, and in some studies, additional doses given every other day (beginning with the 24-28 h dose) for a total of three or nine doses. Thirty-day (30 d) survival was significantly increased with only one dose of 0.3 mg kg of PEG-G-CSF and PEG-IL-11 or three doses of 0.3 mg kg of PEG-GM-CSF (p ≤ 0.006). Enhanced survival correlated with consistently and significantly enhanced WBC, NE, RBC, and PLT recovery for PEG-G- and PEG-GM-CSF, and enhanced RBC and PLT recovery for PEG-IL-11 (p ≤ 0.05). Longer administration schedules or higher doses did not provide a significant additional survival benefit over the shorter, lower dose, schedules. These data demonstrate the efficacy of BBT's PEG-HGF to provide significantly increased survival with fewer injections and lower drug doses, which may have significant economic and logistical value in the aftermath of a radiation event. PMID:24276546

  19. PEGylated G-CSF (BBT-015), GM-CSF (BBT-007), and IL-11 (BBT-059) analogs enhance survival and hematopoietic cell recovery in a mouse model of the Hematopoietic Syndrome of the Acute Radiation Syndrome

    PubMed Central

    Plett, P. Artur; Chua, Hui Lin; Sampson, Carol H.; Katz, Barry P.; Fam, Christine M.; Anderson, Lana J.; Cox, George; Orschell, Christie M.

    2013-01-01

    Hematopoietic growth factors (HGF) are recommended therapy for high dose radiation exposure, but unfavorable administration schedules requiring early and repeat dosing limit the logistical ease with which they can be used. In this report, utilizing our previously described murine model of H-ARS, survival efficacy and effect on hematopoietic recovery of unique PEGylated (PEG) HGF developed by Bolder Biotechnology (BBT) were investigated. The PEGylated-HGF possess longer half-lives and more potent hematopoietic properties than corresponding non-PEGylated-HGFs. C57BL/6 mice underwent single dose lethal irradiation (7.76–8.72 Gy, 137Cs, 0.62–1.02 Gy min−1) and were treated with various dosing regimens of 0.1, 0.3 and 1.0 mg kg−1 of analogs of humanPEG-G-CSF, murinePEG-GM-CSF, or humanPEG-IL-11. Mice were administered one of the HGF analogs at 24–28hr post irradiation, and, in some studies, additional doses given every other day (beginning with the 24–28hr dose) for a total of 3 or 9 doses. 30d survival was significantly increased with only one dose of 0.3mg kg−1 of PEG-G-CSF and PEG-IL-11, or three doses of 0.3mg kg−1 of PEG-GM-CSF (p≤0.006). Enhanced survival correlated with consistently and significantly enhanced WBC, NE, RBC, and PLT recovery for PEG-G- and PEG-GM-CSF, and enhanced RBC and PLT recovery for PEG-IL-11 (p≤0.05). Longer administration schedules or higher doses did not provide a significant additional survival benefit over the shorter, lower dose, schedules. These data demonstrate the efficacy of BBT’s PEG-HGF to provide significantly increased survival with fewer injections and lower drug doses, which may have significant economic and logistical value in the aftermath of a radiation event. PMID:24276546

  20. A mouse model of in utero transplantation.

    PubMed

    Nijagal, Amar; Le, Tom; Wegorzewska, Marta; Mackenzie, Tippi C

    2011-01-01

    The transplantation of stem cells and viruses in utero has tremendous potential for treating congenital disorders in the human fetus. For example, in utero transplantation (IUT) of hematopoietic stem cells has been used to successfully treat patients with severe combined immunodeficiency. In several other conditions, however, IUT has been attempted without success. Given these mixed results, the availability of an efficient non-human model to study the biological sequelae of stem cell transplantation and gene therapy is critical to advance this field. We and others have used the mouse model of IUT to study factors affecting successful engraftment of in utero transplanted hematopoietic stem cells in both wild-type mice and those with genetic diseases. The fetal environment also offers considerable advantages for the success of in utero gene therapy. For example, the delivery of adenoviral, adeno-associated viral, retroviral, and lentiviral vectors into the fetus has resulted in the transduction of multiple organs distant from the site of injection with long-term gene expression. in utero gene therapy may therefore be considered as a possible treatment strategy for single gene disorders such as muscular dystrophy or cystic fibrosis. Another potential advantage of IUT is the ability to induce immune tolerance to a specific antigen. As seen in mice with hemophilia, the introduction of Factor IX early in development results in tolerance to this protein. In addition to its use in investigating potential human therapies, the mouse model of IUT can be a powerful tool to study basic questions in developmental and stem cell biology. For example, one can deliver various small molecules to induce or inhibit specific gene expression at defined gestational stages and manipulate developmental pathways. The impact of these alterations can be assessed at various timepoints after the initial transplantation. Furthermore, one can transplant pluripotent or lineage specific progenitor

  1. The first knockin mouse model of episodic ataxia type 2.

    PubMed

    Rose, Samuel J; Kriener, Lisa H; Heinzer, Ann K; Fan, Xueliang; Raike, Robert S; van den Maagdenberg, Arn M J M; Hess, Ellen J

    2014-11-01

    Episodic ataxia type 2 (EA2) is an autosomal dominant disorder associated with attacks of ataxia that are typically precipitated by stress, ethanol, caffeine or exercise. EA2 is caused by loss-of-function mutations in the CACNA1A gene, which encodes the α1A subunit of the CaV2.1 voltage-gated Ca(2+) channel. To better understand the pathomechanisms of this disorder in vivo, we created the first genetic animal model of EA2 by engineering a mouse line carrying the EA2-causing c.4486T>G (p.F1406C) missense mutation in the orthologous mouse Cacna1a gene. Mice homozygous for the mutated allele exhibit a ~70% reduction in CaV2.1 current density in Purkinje cells, though surprisingly do not exhibit an overt motor phenotype. Mice hemizygous for the knockin allele (EA2/- mice) did exhibit motor dysfunction measurable by rotarod and pole test. Studies using Cre-flox conditional genetics explored the role of cerebellar Purkinje cells or cerebellar granule cells in the poor motor performance of EA2/- mice and demonstrate that manipulation of either cell type alone did not cause poor motor performance. Thus, it is possible that subtle dysfunction arising from multiple cell types is necessary for the expression of certain ataxia syndromes. PMID:25109669

  2. Mouse Genome Database: from sequence to phenotypes and disease models

    PubMed Central

    Eppig, Janan T.; Richardson, Joel E.; Kadin, James A.; Smith, Cynthia L.; Blake, Judith A.; Bult, Carol J.

    2015-01-01

    The Mouse Genome Database (MGD, www.informatics.jax.org) is the international scientific database for genetic, genomic, and biological data on the laboratory mouse to support the research requirements of the biomedical community. To accomplish this goal, MGD provides broad data coverage, serves as the authoritative standard for mouse nomenclature for genes, mutants, and strains, and curates and integrates many types of data from literature and electronic sources. Among the key data sets MGD supports are: the complete catalog of mouse genes and genome features, comparative homology data for mouse and vertebrate genes, the authoritative set of Gene Ontology (GO) annotations for mouse gene functions, a comprehensive catalog of mouse mutations and their phenotypes, and a curated compendium of mouse models of human diseases. Here we describe the data acquisition process, specifics about MGD’s key data areas, methods to access and query MGD data, and outreach and user help facilities. PMID:26150326

  3. Mouse Genome Database: From sequence to phenotypes and disease models.

    PubMed

    Eppig, Janan T; Richardson, Joel E; Kadin, James A; Smith, Cynthia L; Blake, Judith A; Bult, Carol J

    2015-08-01

    The Mouse Genome Database (MGD, www.informatics.jax.org) is the international scientific database for genetic, genomic, and biological data on the laboratory mouse to support the research requirements of the biomedical community. To accomplish this goal, MGD provides broad data coverage, serves as the authoritative standard for mouse nomenclature for genes, mutants, and strains, and curates and integrates many types of data from literature and electronic sources. Among the key data sets MGD supports are: the complete catalog of mouse genes and genome features, comparative homology data for mouse and vertebrate genes, the authoritative set of Gene Ontology (GO) annotations for mouse gene functions, a comprehensive catalog of mouse mutations and their phenotypes, and a curated compendium of mouse models of human diseases. Here, we describe the data acquisition process, specifics about MGD's key data areas, methods to access and query MGD data, and outreach and user help facilities. PMID:26150326

  4. Marijuana withdrawal syndrome in the animal model.

    PubMed

    Lichtman, Aron H; Martin, Billy R

    2002-11-01

    Although the proposition that repeated marijuana use can lead to marijuana dependence has long been accepted, only recently has evidence emerged suggesting that abstinence leads to clinically significant withdrawal symptoms. Converging evidence from human and animal studies has increased our understanding of cannabinoid dependence. One of the most powerful tools to advance this area of research is the CB1 cannabinoid receptor antagonist SR 141716A, which reliably precipitates withdrawal syndromes in mice, rats, and dogs that have been treated repeatedly with cannabinoids. In addition, the use of CB1 receptor knockout mice has revealed that not only cannabinoid dependence is mediated through a CB1 receptor mechanism of action, but CB1 receptors also modulate opioid dependence. Moreover, the results of other genetically altered mouse models suggest the existence of a reciprocal relationship between cannabinoid and opioid systems in drug dependence. Undoubtedly, these animal models will play pivotal roles in further characterizing cannabinoid dependence and elucidating the mechanisms of action, as well as developing potential pharmacotherapies for cannabinoid dependence. PMID:12412832

  5. Mouse models of osteoarthritis: modelling risk factors and assessing outcomes.

    PubMed

    Fang, Hang; Beier, Frank

    2014-07-01

    Osteoarthritis (OA) is a prevalent musculoskeletal disease that results in pain and low quality of life for patients, as well as enormous medical and socioeconomic burdens. The molecular mechanisms responsible for the initiation and progression of OA are still poorly understood. As such, mouse models of the disease are having increasingly important roles in OA research owing to the advancements of microsurgical techniques and the use of genetically modified mice, as well as the development of novel assessment tools. In this Review, we discuss available mouse models of OA and applicable assessment tools in studies of experimental OA. PMID:24662645

  6. Insights from mouse models into human retinoblastoma

    PubMed Central

    MacPherson, David

    2008-01-01

    Novel murine models of retinoblastoma based on Rb gene deletion in concert with inactivation of Rb family members have recently been developed. These new Rb knockout models of retinoblastoma provide excellent tools for pre-clinical studies and for the exploration of the genetics of tumorigenesis driven by RB inactivation. This review focuses on the developmental consequences of Rb deletion in the retina and the genetic interactions between Rb and the two other members of the pocket protein family, p107 (Rbl1) and p130 (Rbl2). There is increasing appreciation that homozygous RB mutations are insufficient for human retinoblastoma. Identifying and understanding secondary gene alterations that cooperate with RB inactivation in tumorigenesis may be facilitated by mouse models. Recent investigation of the p53 pathway in retinoblastoma, and evidence of spatial topology to early murine retinoblastoma are also discussed in this review. PMID:18489754

  7. Is the Mouse a Good Model of Human PPARγ-Related Metabolic Diseases?

    PubMed

    Pap, Attila; Cuaranta-Monroy, Ixchelt; Peloquin, Matthew; Nagy, Laszlo

    2016-01-01

    With the increasing number of patients affected with metabolic diseases such as type 2 diabetes, obesity, atherosclerosis and insulin resistance, academic researchers and pharmaceutical companies are eager to better understand metabolic syndrome and develop new drugs for its treatment. Many studies have focused on the nuclear receptor peroxisome proliferator-activated receptor gamma (PPARγ), which plays a crucial role in adipogenesis and lipid metabolism. These studies have been able to connect this transcription factor to several human metabolic diseases. Due to obvious limitations concerning experimentation in humans, animal models-mainly mouse models-have been generated to investigate the role of PPARγ in different tissues. This review focuses on the metabolic features of human and mouse PPARγ-related diseases and the utility of the mouse as a model. PMID:27483259

  8. Genetically Engineered Mouse Models for Studying Inflammatory Bowel Disease

    PubMed Central

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

    2015-01-01

    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. PMID:26387641

  9. Disruption of Mouse Cenpj, a Regulator of Centriole Biogenesis, Phenocopies Seckel Syndrome

    PubMed Central

    McIntyre, Rebecca E.; Lakshminarasimhan Chavali, Pavithra; Forment, Josep V.; Fu, Beiyuan; Del Castillo Velasco-Herrera, Martin; Edwards, Andrew; van der Weyden, Louise; Yang, Fengtang; Ramirez-Solis, Ramiro; Estabel, Jeanne; Gallagher, Ferdia A.; Logan, Darren W.; Arends, Mark J.; Tsang, Stephen H.; Mahajan, Vinit B.; Scudamore, Cheryl L.; White, Jacqueline K.; Jackson, Stephen P.; Gergely, Fanni; Adams, David J.

    2012-01-01

    Disruption of the centromere protein J gene, CENPJ (CPAP, MCPH6, SCKL4), which is a highly conserved and ubiquitiously expressed centrosomal protein, has been associated with primary microcephaly and the microcephalic primordial dwarfism disorder Seckel syndrome. The mechanism by which disruption of CENPJ causes the proportionate, primordial growth failure that is characteristic of Seckel syndrome is unknown. By generating a hypomorphic allele of Cenpj, we have developed a mouse (Cenpjtm/tm) that recapitulates many of the clinical features of Seckel syndrome, including intrauterine dwarfism, microcephaly with memory impairment, ossification defects, and ocular and skeletal abnormalities, thus providing clear confirmation that specific mutations of CENPJ can cause Seckel syndrome. Immunohistochemistry revealed increased levels of DNA damage and apoptosis throughout Cenpjtm/tm embryos and adult mice showed an elevated frequency of micronucleus induction, suggesting that Cenpj-deficiency results in genomic instability. Notably, however, genomic instability was not the result of defective ATR-dependent DNA damage signaling, as is the case for the majority of genes associated with Seckel syndrome. Instead, Cenpjtm/tm embryonic fibroblasts exhibited irregular centriole and centrosome numbers and mono- and multipolar spindles, and many were near-tetraploid with numerical and structural chromosomal abnormalities when compared to passage-matched wild-type cells. Increased cell death due to mitotic failure during embryonic development is likely to contribute to the proportionate dwarfism that is associated with CENPJ-Seckel syndrome. PMID:23166506

  10. The Mouse Genome Database (MGD): facilitating mouse as a model for human biology and disease.

    PubMed

    Eppig, Janan T; Blake, Judith A; Bult, Carol J; Kadin, James A; Richardson, Joel E

    2015-01-01

    The Mouse Genome Database (MGD, http://www.informatics.jax.org) serves the international biomedical research community as the central resource for integrated genomic, genetic and biological data on the laboratory mouse. To facilitate use of mouse as a model in translational studies, MGD maintains a core of high-quality curated data and integrates experimentally and computationally generated data sets. MGD maintains a unified catalog of genes and genome features, including functional RNAs, QTL and phenotypic loci. MGD curates and provides functional and phenotype annotations for mouse genes using the Gene Ontology and Mammalian Phenotype Ontology. MGD integrates phenotype data and associates mouse genotypes to human diseases, providing critical mouse-human relationships and access to repositories holding mouse models. MGD is the authoritative source of nomenclature for genes, genome features, alleles and strains following guidelines of the International Committee on Standardized Genetic Nomenclature for Mice. A new addition to MGD, the Human-Mouse: Disease Connection, allows users to explore gene-phenotype-disease relationships between human and mouse. MGD has also updated search paradigms for phenotypic allele attributes, incorporated incidental mutation data, added a module for display and exploration of genes and microRNA interactions and adopted the JBrowse genome browser. MGD resources are freely available to the scientific community. PMID:25348401

  11. The activity-based anorexia mouse model.

    PubMed

    Klenotich, Stephanie J; Dulawa, Stephanie C

    2012-01-01

    Animals housed with running wheels and subjected to daily food restriction show paradoxical reductions in food intake and increases in running wheel activity. This phenomenon, known as activity-based anorexia (ABA), leads to marked reductions in body weight that can ultimately lead to death. Recently, ABA has been proposed as a model of anorexia nervosa (AN). AN affects about 8 per 100,000 females and has the highest mortality rate among all psychiatric illnesses. Given the reductions in quality of life, high mortality rate, and the lack of pharmacological treatments for AN, a better understanding of the mechanisms underlying AN-like behavior is greatly needed. This chapter provides basic guidelines for conducting ABA experiments using mice. The ABA mouse model provides an important tool for investigating the neurobiological underpinnings of AN-like behavior and identifying novel treatments. PMID:22231828

  12. Attenuation of Morphine Withdrawal Syndrome by Various Dosages of Curcumin in Comparison with Clonidine in Mouse: Possible Mechanism

    PubMed Central

    Motaghinejad, Majid; Bangash, Mohammad Yasan; Hosseini, Pantea; Karimian, Seyed Morteza; Motaghinejad, Ozra

    2015-01-01

    Background Herbal medical compounds and their major constituent have been used in the management and treatment of opioid withdrawal syndrome and pain. This study was carried out to clarify the effect of curcumin, the major compound of turmeric, on morphine withdrawal syndrome in mouse model and its possible mechanisms of pain relieving activity by assessing in writhing test as a model of visceral pain. Methods Due to two separate protocols (withdrawal syndrome and pain), 144 male albino mice were divided in two major groups. In withdrawal syndrome group, test effect of various dosages of curcumin (10, 20, and 40 mg/kg) was assessed on withdrawal signs and compared with positive and negative control and standard treatment (clonidine 0.4 mg/kg) groups. In pain groups, to determine the mechanism of pain relieving activity of curcumin, various dosages of curcumin (10, 20, and 40 mg/kg) in three separated groups, were used against acetic acid induced writhing (which is a constriction) test. The most effective dose (40 mg/kg) was used in writhing test and compared with groups pretreated with antagonist of major neurotransmitters involved in pain; and compared with group pretreated with vehicle (DMSO, 0.05%) as control. Results Curcumin attenuates withdrawal syndrome in a dose dependent manner in comparison with the dependent positive control group (P<0.05). It also indicated that pretreatment with naloxone and cyproheptadine significantly attenuate antinociception effect of curcumin (P<0.05). Conclusion This study advocate that antinociception of curcumin was mediated by opioidergic and adrenergic system. PMID:25821292

  13. A New Mouse Model That Spontaneously Develops Chronic Liver Inflammation and Fibrosis

    PubMed Central

    Fransén-Pettersson, Nina; Duarte, Nadia; Nilsson, Julia; Lundholm, Marie; Mayans, Sofia; Larefalk, Åsa; Hannibal, Tine D.; Hansen, Lisbeth; Schmidt-Christensen, Anja; Ivars, Fredrik; Cardell, Susanna; Palmqvist, Richard; Rozell, Björn

    2016-01-01

    Here we characterize a new animal model that spontaneously develops chronic inflammation and fibrosis in multiple organs, the non-obese diabetic inflammation and fibrosis (N-IF) mouse. In the liver, the N-IF mouse displays inflammation and fibrosis particularly evident around portal tracts and central veins and accompanied with evidence of abnormal intrahepatic bile ducts. The extensive cellular infiltration consists mainly of macrophages, granulocytes, particularly eosinophils, and mast cells. This inflammatory syndrome is mediated by a transgenic population of natural killer T cells (NKT) induced in an immunodeficient NOD genetic background. The disease is transferrable to immunodeficient recipients, while polyclonal T cells from unaffected syngeneic donors can inhibit the disease phenotype. Because of the fibrotic component, early on-set, spontaneous nature and reproducibility, this novel mouse model provides a unique tool to gain further insight into the underlying mechanisms mediating transformation of chronic inflammation into fibrosis and to evaluate intervention protocols for treating conditions of fibrotic disorders. PMID:27441847

  14. The Mouse Genome Database (MGD): facilitating mouse as a model for human biology and disease

    PubMed Central

    Eppig, Janan T.; Blake, Judith A.; Bult, Carol J.; Kadin, James A.; Richardson, Joel E.

    2015-01-01

    The Mouse Genome Database (MGD, http://www.informatics.jax.org) serves the international biomedical research community as the central resource for integrated genomic, genetic and biological data on the laboratory mouse. To facilitate use of mouse as a model in translational studies, MGD maintains a core of high-quality curated data and integrates experimentally and computationally generated data sets. MGD maintains a unified catalog of genes and genome features, including functional RNAs, QTL and phenotypic loci. MGD curates and provides functional and phenotype annotations for mouse genes using the Gene Ontology and Mammalian Phenotype Ontology. MGD integrates phenotype data and associates mouse genotypes to human diseases, providing critical mouse–human relationships and access to repositories holding mouse models. MGD is the authoritative source of nomenclature for genes, genome features, alleles and strains following guidelines of the International Committee on Standardized Genetic Nomenclature for Mice. A new addition to MGD, the Human–Mouse: Disease Connection, allows users to explore gene–phenotype–disease relationships between human and mouse. MGD has also updated search paradigms for phenotypic allele attributes, incorporated incidental mutation data, added a module for display and exploration of genes and microRNA interactions and adopted the JBrowse genome browser. MGD resources are freely available to the scientific community. PMID:25348401

  15. Memory B cells in mouse models.

    PubMed

    Bergmann, B; Grimsholm, O; Thorarinsdottir, K; Ren, W; Jirholt, P; Gjertsson, I; Mårtensson, I-L

    2013-08-01

    One of the principles behind vaccination, as shown by Edward Jenner in 1796, and host protection is immunological memory, and one of the cells central to this is the antigen-experienced memory B cell that responds rapidly upon re-exposure to the initiating antigen. Classically, memory B cells have been defined as progenies of germinal centre (GC) B cells expressing isotype-switched and substantially mutated B cell receptors (BCRs), that is, membrane-bound antibodies. However, it has become apparent over the last decade that this is not the only pathway to B cell memory. Here, we will discuss memory B cells in mice, as defined by (1) cell surface markers; (2) multiple layers; (3) formation in a T cell-dependent and either GC-dependent or GC-independent manner; (4) formation in a T cell-independent fashion. Lastly, we will touch upon memory B cells in; (5) mouse models of autoimmune diseases. PMID:23679222

  16. A Transgenic Mouse Model of Poliomyelitis.

    PubMed

    Koike, Satoshi; Nagata, Noriyo

    2016-01-01

    Transgenic mice (tg mice) that express the human poliovirus receptor (PVR), CD155, are susceptible to poliovirus and develop a neurological disease that resembles human poliomyelitis. Assessment of the neurovirulence levels of poliovirus strains, including mutant viruses produced by reverse genetics, circulating vaccine-derived poliovirus, and vaccine candidates, is useful for basic research of poliovirus pathogenicity, the surveillance of circulating polioviruses, and the quality control of oral live poliovirus vaccines, and does not require the use of monkeys. Furthermore, PVR-tg mice are useful for studying poliovirus tissue tropism and host immune responses. PVR-tg mice can be bred with mice deficient in the genes involved in viral pathogenicity. This report describes the methods used to analyze the pathogenicity and immune responses of poliovirus using the PVR-tg mouse model. PMID:26983733

  17. A mouse model for testing remyelinating therapies.

    PubMed

    Bai, C Brian; Sun, Sunny; Roholt, Andrew; Benson, Emily; Edberg, Dale; Medicetty, Satish; Dutta, Ranjan; Kidd, Grahame; Macklin, Wendy B; Trapp, Bruce

    2016-09-01

    Used in combination with immunomodulatory therapies, remyelinating therapies are a viable therapeutic approach for treating individuals with multiple sclerosis. Studies of postmortem MS brains identified greater remyelination in demyelinated cerebral cortex than in demyelinated brain white matter and implicated reactive astrocytes as an inhibitor of white matter remyelination. An animal model that recapitulates these phenotypes would benefit the development of remyelination therapeutics. We have used a modified cuprizone protocol that causes a consistent and robust demyelination of mouse white matter and cerebral cortex. Spontaneous remyelination occurred significantly faster in the cerebral cortex than in white matter and reactive astrocytes were more abundant in white matter lesions. Remyelination of white matter and cerebral cortex was therapeutically enhanced by daily injections of thyroid hormone triiodothyronine (T3). In summary, we describe an in vivo demyelination/remyelination paradigm that can be powered to determine efficacy of therapies that enhance white matter and cortical remyelination. PMID:27384502

  18. Preclinical fluorescent mouse models of pancreatic cancer

    NASA Astrophysics Data System (ADS)

    Bouvet, Michael; Hoffman, Robert M.

    2007-02-01

    Here we describe our cumulative experience with the development and preclinical application of several highly fluorescent, clinically-relevant, metastatic orthotopic mouse models of pancreatic cancer. These models utilize the human pancreatic cancer cell lines which have been genetically engineered to selectively express high levels of the bioluminescent green fluorescent (GFP) or red fluorescent protein (RFP). Fluorescent tumors are established subcutaneously in nude mice, and tumor fragments are then surgically transplanted onto the pancreas. Locoregional tumor growth and distant metastasis of these orthotopic implants occurs spontaneously and rapidly throughout the abdomen in a manner consistent with clinical human disease. Highly specific, high-resolution, real-time visualization of tumor growth and metastasis may be achieved in vivo without the need for contrast agents, invasive techniques, or expensive imaging equipment. We have shown a high correlation between florescent optical imaging and magnetic resonance imaging in these models. Alternatively, transplantation of RFP-expressing tumor fragments onto the pancreas of GFP-expressing transgenic mice may be used to facilitate visualization of tumor-host interaction between the pancreatic tumor fragments and host-derived stroma and vasculature. Such in vivo models have enabled us to serially visualize and acquire images of the progression of pancreatic cancer in the live animal, and to demonstrate the real-time antitumor and antimetastatic effects of several novel therapeutic strategies on pancreatic malignancy. These fluorescent models are therefore powerful and reliable tools with which to investigate human pancreatic cancer and therapeutic strategies directed against it.

  19. Developmental and maintenance defects in Rett syndrome neurons identified by a new mouse staging system in vitro

    PubMed Central

    Baj, Gabriele; Patrizio, Angela; Montalbano, Alberto; Sciancalepore, Marina; Tongiorgi, Enrico

    2013-01-01

    Rett Syndrome (RTT) is a neurodevelopmental disorder associated with intellectual disability, mainly caused by loss-of-function mutations in the MECP2 gene. RTT brains display decreased neuronal size and dendritic arborization possibly caused by either a developmental failure or a deficit in the maintenance of dendritic arbor structure. To distinguish between these two hypotheses, the development of Mecp2-knockout mouse hippocampal neurons was analyzed in vitro. Since a staging system for the in vitro development of mouse neurons was lacking, mouse and rat hippocampal neurons development was compared between 1–15 days in vitro (DIV) leading to a 6-stage model for both species. Mecp2-knockout hippocampal neurons displayed reduced growth of dendritic branches from stage 4 (DIV4) onwards. At stages 5–6 (DIV9-15), synapse number was lowered in Mecp2-knockout neurons, suggesting increased synapse elimination. These results point to both a developmental and a maintenance setback affecting the final shape and function of neurons in RTT. PMID:24550777

  20. Generation of transgenic mouse model using PTTG as an oncogene.

    PubMed

    Kakar, Sham S; Kakar, Cohin

    2015-01-01

    The close physiological similarity between the mouse and human has provided tools to understanding the biological function of particular genes in vivo by introduction or deletion of a gene of interest. Using a mouse as a model has provided a wealth of resources, knowledge, and technology, helping scientists to understand the biological functions, translocation, trafficking, and interaction of a candidate gene with other intracellular molecules, transcriptional regulation, posttranslational modification, and discovery of novel signaling pathways for a particular gene. Most importantly, the generation of the mouse model for a specific human disease has provided a powerful tool to understand the etiology of a disease and discovery of novel therapeutics. This chapter describes in detail the step-by-step generation of the transgenic mouse model, which can be helpful in guiding new investigators in developing successful models. For practical purposes, we will describe the generation of a mouse model using pituitary tumor transforming gene (PTTG) as the candidate gene of interest. PMID:25636481

  1. Choosing a mouse model to study the molecular pathobiology of Alport glomerulonephritis.

    PubMed

    Cosgrove, D; Kalluri, R; Miner, J H; Segal, Y; Borza, D-B

    2007-04-01

    Alport syndrome, caused by mutations that interfere with the normal assembly of the alpha3alpha4alpha5(IV) collagen network in the glomerular basement membrane (GBM), is the most common inherited glomerular disease leading to renal failure. A detailed knowledge of the underlying pathogenic mechanisms is necessary for developing new, more specific, and effective therapeutic strategies aimed at delaying the onset and slowing disease progression. Studies of several dog and mouse models of Alport syndrome have significantly enhanced our understanding of the disease mechanisms and provided systems for testing potential therapies. In the most widely used Col4a3-/- mouse models of autosomal-recessive Alport syndrome (ARAS), the genetic background strongly affects renal survival. One contributing factor may be the strong ectopic deposition of alpha5alpha6(IV) collagen in the GBM of Col4a3-/- mice on the C57BL/6J background, which is almost undetectable on the 129/Sv background. This isoform 'switch' has not been observed in human ARAS, although it had been reported in the dog model of ARAS. In human patients as well as dog and mouse models of X-linked Alport syndrome, the alpha3-alpha6(IV) collagen chains are absent from the GBM. These biochemical differences among Alport animal models provide an opportunity to determine how the molecular makeup of the GBM affects the glomerular function. At the same time, potentially confounding influences of characteristics unique to a particular strain or model should be carefully considered in the design of studies aiming to define key events underlying the pathobiology of Alport glomerular disease. PMID:17290292

  2. Mouse models of colorectal cancer as preclinical models

    PubMed Central

    Buczacki, Simon J.A.; Arends, Mark J.; Adams, David J.

    2015-01-01

    In this review, we discuss the application of mouse models to the identification and pre‐clinical validation of novel therapeutic targets in colorectal cancer, and to the search for early disease biomarkers. Large‐scale genomic, transcriptomic and epigenomic profiling of colorectal carcinomas has led to the identification of many candidate genes whose direct contribution to tumourigenesis is yet to be defined; we discuss the utility of cross‐species comparative ‘omics‐based approaches to this problem. We highlight recent progress in modelling late‐stage disease using mice, and discuss ways in which mouse models could better recapitulate the complexity of human cancers to tackle the problem of therapeutic resistance and recurrence after surgical resection. PMID:26115037

  3. Mouse model for sublethal Leptospira interrogans infection.

    PubMed

    Richer, Luciana; Potula, Hari-Hara; Melo, Rita; Vieira, Ana; Gomes-Solecki, Maria

    2015-12-01

    Although Leptospira can infect a wide range of mammalian species, most studies have been conducted in golden Syrian hamsters, a species particularly sensitive to acute disease. Chronic disease has been well characterized in the rat, one of the natural reservoir hosts. Studies in another asymptomatic reservoir host, the mouse, have occasionally been done and have limited infection to mice younger than 6 weeks of age. We analyzed the outcome of sublethal infection of C3H/HeJ mice older than age 10 weeks with Leptospira interrogans serovar Copenhageni. Infection led to bloodstream dissemination of Leptospira, which was followed by urinary shedding, body weight loss, hypothermia, and colonization of the kidney by live spirochetes 2 weeks after infection. In addition, Leptospira dissemination triggered inflammation in the kidney but not in the liver or lung, as determined by increased levels of mRNA transcripts for the keratinocyte-derived chemokine, RANTES, macrophage inflammatory protein 2, tumor necrosis factor alpha, interleukin-1β, inducible nitric oxide synthase, interleukin-6, and gamma interferon in kidney tissue. The acquired humoral response to Leptospira infection led to the production of IgG mainly of the IgG1 subtype. Flow cytometric analysis of splenocytes from infected mice revealed that cellular expansion was primarily due to an increase in the levels of CD4(+) and double-negative T cells (not CD8(+) cells) and that CD4(+) T cells acquired a CD44(high) CD62L(low) effector phenotype not accompanied by increases in memory T cells. A mouse model for sublethal Leptospira infection allows understanding of the bacterial and host factors that lead to immune evasion, which can result in acute or chronic disease or resistance to infection (protection). PMID:26416909

  4. Mouse Model for Sublethal Leptospira interrogans Infection

    PubMed Central

    Richer, Luciana; Potula, Hari-Hara; Melo, Rita; Vieira, Ana

    2015-01-01

    Although Leptospira can infect a wide range of mammalian species, most studies have been conducted in golden Syrian hamsters, a species particularly sensitive to acute disease. Chronic disease has been well characterized in the rat, one of the natural reservoir hosts. Studies in another asymptomatic reservoir host, the mouse, have occasionally been done and have limited infection to mice younger than 6 weeks of age. We analyzed the outcome of sublethal infection of C3H/HeJ mice older than age 10 weeks with Leptospira interrogans serovar Copenhageni. Infection led to bloodstream dissemination of Leptospira, which was followed by urinary shedding, body weight loss, hypothermia, and colonization of the kidney by live spirochetes 2 weeks after infection. In addition, Leptospira dissemination triggered inflammation in the kidney but not in the liver or lung, as determined by increased levels of mRNA transcripts for the keratinocyte-derived chemokine, RANTES, macrophage inflammatory protein 2, tumor necrosis factor alpha, interleukin-1β, inducible nitric oxide synthase, interleukin-6, and gamma interferon in kidney tissue. The acquired humoral response to Leptospira infection led to the production of IgG mainly of the IgG1 subtype. Flow cytometric analysis of splenocytes from infected mice revealed that cellular expansion was primarily due to an increase in the levels of CD4+ and double-negative T cells (not CD8+ cells) and that CD4+ T cells acquired a CD44high CD62Llow effector phenotype not accompanied by increases in memory T cells. A mouse model for sublethal Leptospira infection allows understanding of the bacterial and host factors that lead to immune evasion, which can result in acute or chronic disease or resistance to infection (protection). PMID:26416909

  5. Transgenic Mouse Model of Chronic Beryllium Disease

    SciTech Connect

    Gordon, Terry

    2009-05-26

    Animal models provide powerful tools for dissecting dose-response relationships and pathogenic mechanisms and for testing new treatment paradigms. Mechanistic research on beryllium exposure-disease relationships is severely limited by a general inability to develop a sufficient chronic beryllium disease animal model. Discovery of the Human Leukocyte Antigen (HLA) - DPB1Glu69 genetic susceptibility component of chronic beryllium disease permitted the addition of this human beryllium antigen presentation molecule to an animal genome which may permit development of a better animal model for chronic beryllium disease. Using FVB/N inbred mice, Drs. Rubin and Zhu, successfully produced three strains of HLA-DPB1 Glu 69 transgenic mice. Each mouse strain contains a haplotype of the HLA-DPB1 Glu 69 gene that confers a different magnitude of odds ratio (OR) of risk for chronic beryllium disease: HLA-DPB1*0401 (OR = 0.2), HLA-DPB1*0201 (OR = 15), HLA-DPB1*1701 (OR = 240). In addition, Drs. Rubin and Zhu developed transgenic mice with the human CD4 gene to permit better transmission of signals between T cells and antigen presenting cells. This project has maintained the colonies of these transgenic mice and tested the functionality of the human transgenes.

  6. Mouse infection models for space flight immunology

    NASA Technical Reports Server (NTRS)

    Chapes, Stephen Keith; Ganta, Roman Reddy; Chapers, S. K. (Principal Investigator)

    2005-01-01

    Several immunological processes can be affected by space flight. However, there is little evidence to suggest that flight-induced immunological deficits lead to illness. Therefore, one of our goals has been to define models to examine host resistance during space flight. Our working hypothesis is that space flight crews will come from a heterogeneous population; the immune response gene make-up will be quite varied. It is unknown how much the immune response gene variation contributes to the potential threat from infectious organisms, allergic responses or other long term health problems (e.g. cancer). This article details recent efforts of the Kansas State University gravitational immunology group to assess how population heterogeneity impacts host health, either in laboratory experimental situations and/or using the skeletal unloading model of space-flight stress. This paper details our use of several mouse strains with several different genotypes. In particular, mice with varying MHCII allotypes and mice on the C57BL background with different genetic defects have been particularly useful tools with which to study infections by Staphylococcus aureus, Salmonella typhimurium, Pasteurella pneumotropica and Ehrlichia chaffeensis. We propose that some of these experimental challenge models will be useful to assess the effects of space flight on host resistance to infection.

  7. Is the Mouse a Good Model of Human PPARγ-Related Metabolic Diseases?

    PubMed Central

    Pap, Attila; Cuaranta-Monroy, Ixchelt; Peloquin, Matthew; Nagy, Laszlo

    2016-01-01

    With the increasing number of patients affected with metabolic diseases such as type 2 diabetes, obesity, atherosclerosis and insulin resistance, academic researchers and pharmaceutical companies are eager to better understand metabolic syndrome and develop new drugs for its treatment. Many studies have focused on the nuclear receptor peroxisome proliferator-activated receptor gamma (PPARγ), which plays a crucial role in adipogenesis and lipid metabolism. These studies have been able to connect this transcription factor to several human metabolic diseases. Due to obvious limitations concerning experimentation in humans, animal models—mainly mouse models—have been generated to investigate the role of PPARγ in different tissues. This review focuses on the metabolic features of human and mouse PPARγ-related diseases and the utility of the mouse as a model. PMID:27483259

  8. Reproductive and metabolic phenotype of a mouse model of PCOS.

    PubMed

    van Houten, E Leonie A F; Kramer, Piet; McLuskey, Anke; Karels, Bas; Themmen, Axel P N; Visser, Jenny A

    2012-06-01

    Polycystic ovary syndrome (PCOS), the most common endocrine disorder in women in their reproductive age, is characterized by both reproductive and metabolic features. Recent studies in human, nonhuman primates, and sheep suggest that hyperandrogenism plays an important role in the development of PCOS. We investigated whether chronic dihydrotestosterone (DHT) exposure in mice reproduces both features of PCOS. Such a model would allow us to study the mechanism of association between the reproductive and metabolic features in transgenic mice. In this study, prepubertal female mice received a 90 d continuous release pellet containing the nonaromatizable androgen DHT or vehicle. At the end of the treatment period, DHT-treated mice were in continuous anestrous, their ovaries contained an increased number of atretic follicles, with the majority of atretic antral follicles having a cyst-like structure. Chronic DHT-exposed mice had significantly higher body weights (21%) than vehicle-treated mice. In addition, fat depots of DHT-treated mice displayed an increased number of enlarged adipocytes (P < 0.003). Leptin levels were elevated (P < 0.013), adiponectin levels were diminished (P < 0.001), and DHT-treated mice were glucose intolerant (P < 0.001). In conclusion, a mouse model of PCOS has been developed showing reproductive and metabolic characteristics associated with PCOS in women. PMID:22334715

  9. Mouse models for gastric cancer: Matching models to biological questions.

    PubMed

    Poh, Ashleigh R; O'Donoghue, Robert J J; Ernst, Matthias; Putoczki, Tracy L

    2016-07-01

    Gastric cancer is the third leading cause of cancer-related mortality worldwide. This is in part due to the asymptomatic nature of the disease, which often results in late-stage diagnosis, at which point there are limited treatment options. Even when treated successfully, gastric cancer patients have a high risk of tumor recurrence and acquired drug resistance. It is vital to gain a better understanding of the molecular mechanisms underlying gastric cancer pathogenesis to facilitate the design of new-targeted therapies that may improve patient survival. A number of chemically and genetically engineered mouse models of gastric cancer have provided significant insight into the contribution of genetic and environmental factors to disease onset and progression. This review outlines the strengths and limitations of current mouse models of gastric cancer and their relevance to the pre-clinical development of new therapeutics. PMID:26809278

  10. Mouse models for radiation-induced cancers.

    PubMed

    Rivina, Leena; Davoren, Michael J; Schiestl, Robert H

    2016-09-01

    Potential ionising radiation exposure scenarios are varied, but all bring risks beyond the simple issues of short-term survival. Whether accidentally exposed to a single, whole-body dose in an act of terrorism or purposefully exposed to fractionated doses as part of a therapeutic regimen, radiation exposure carries the consequence of elevated cancer risk. The long-term impact of both intentional and unintentional exposure could potentially be mitigated by treatments specifically developed to limit the mutations and precancerous replication that ensue in the wake of irradiation The development of such agents would undoubtedly require a substantial degree of in vitro testing, but in order to accurately recapitulate the complex process of radiation-induced carcinogenesis, well-understood animal models are necessary. Inbred strains of the laboratory mouse, Mus musculus, present the most logical choice due to the high number of molecular and physiological similarities they share with humans. Their small size, high rate of breeding and fully sequenced genome further increase its value for use in cancer research. This chapter will review relevant m. musculus inbred and F1 hybrid animals of radiation-induced myeloid leukemia, thymic lymphoma, breast and lung cancers. Method of cancer induction and associated molecular pathologies will also be described for each model. PMID:27209205

  11. A mouse model for infectious mononucleosis.

    PubMed

    Flaño, Emilio; Woodland, David L; Blackman, Marcia A

    2002-01-01

    Epstein-Barr virus (EBV) is a ubiquitous human gamma-herpesvirus that establishes life-long latency and is associated with lymphoproliferative disorders and the development of several malignancies. EBV infection is frequently, but not always, associated with the development of a syndrome termed infectious mononucleosis. The recent isolation and characterization of a murine gamma-herpesvirus, MHV-68 (gammaHV-68) has provided the first small animal model for studying immunity and pathogenesis of a gamma-herpesvirus in its natural host. MHV-68 has important biological and genetic similarities with the human gamma-herpesviruses. Following intranasal infection of mice with MHV-68, an acute respiratory infection in the lung develops and is cleared, followed by the establishment of latency. Similar to EBV, MHV-68 latency is largely established in B cells, although other cell types can be latently infected. The establishment of latency correlates with a prominent splenomegaly, polyclonal B cell activation with associated autoantibody production, and CD8+ T cell-dominated peripheral blood lymphocytosis, in many aspects mirroring EBV-induced infectious mononucleosis. There are key differences in the MHV-68- and EBV-induced CD8+ T cell responses however. Whereas the expanded CD8+ T cells associated with EBV-induced mononucleosis are largely the outgrowth of T cells responding to lytic viral epitopes elicited during the acute phase of the response, the CD8+ T cell lymphocytosis associated with MHV-68-induced infectious mononucleosis is dominated by an oligoclonal population of T cells expressing Vbeta4+ T cell receptors that are not reactive to acute viral epitopes. The focus of this article will be to highlight the similarities and differences in the infectious mononucleosis syndrome associated with human and murine gamma-herpesviruses. PMID:12018460

  12. Understanding the Basis of Auriculocondylar Syndrome: Insights From Human and Mouse Genetic Studies

    PubMed Central

    Clouthier, David E.; Passos Bueno, Maria Rita; Tavares, Andre L.P.; Lyonnet, Stanislas; Amiel, Jeanne; Gordon, Christopher T.

    2014-01-01

    Among human birth defect syndromes, malformations affecting the face are perhaps the most striking due to cultural and psychological expectations of facial shape. One such syndrome is auriculocondylar syndrome (ACS), in which patients present with defects in ear and mandible development. Affected structures arise from cranial neural crest cells, a population of cells in the embryo that reside in the pharyngeal arches and give rise to most of the bone, cartilage and connective tissue of the face. Recent studies have found that most cases of ACS arise from defects in signaling molecules associated with the endothelin signaling pathway. Disruption of this signaling pathway in both mouse and zebrafish results in loss of identity of neural crest cells of the mandibular portion of the first pharyngeal arch and the subsequent repatterning of these cells, leading to homeosis of lower jaw structures into more maxillary-like structures. These findings illustrate the importance of endothelin signaling in normal human craniofacial development and illustrate how clinical and basic science approaches can coalesce to improve our understanding of the genetic basis of human birth syndromes. Further, understanding the genetic basis for ACS that lies outside of known endothelin signaling components may help elucidate unknown aspects critical to the establishment of neural crest cell patterning during facial morphogenesis. PMID:24123988

  13. Identifying mouse models for skin cancer using the Mouse Tumor Biology Database.

    PubMed

    Begley, Dale A; Krupke, Debra M; Neuhauser, Steven B; Richardson, Joel E; Schofield, Paul N; Bult, Carol J; Eppig, Janan T; Sundberg, John P

    2014-10-01

    In recent years, the scientific community has generated an ever-increasing amount of data from a growing number of animal models of human cancers. Much of these data come from genetically engineered mouse models. Identifying appropriate models for skin cancer and related relevant genetic data sets from an expanding pool of widely disseminated data can be a daunting task. The Mouse Tumor Biology Database (MTB) provides an electronic archive, search and analysis system that can be used to identify dermatological mouse models of cancer, retrieve model-specific data and analyse these data. In this report, we detail MTB's contents and capabilities, together with instructions on how to use MTB to search for skin-related tumor models and associated data. PMID:25040013

  14. A Mouse Model of Zika Virus Pathogenesis.

    PubMed

    Lazear, Helen M; Govero, Jennifer; Smith, Amber M; Platt, Derek J; Fernandez, Estefania; Miner, Jonathan J; Diamond, Michael S

    2016-05-11

    The ongoing Zika virus (ZIKV) epidemic and unexpected clinical outcomes, including Guillain-Barré syndrome and birth defects, has brought an urgent need for animal models. We evaluated infection and pathogenesis with contemporary and historical ZIKV strains in immunocompetent mice and mice lacking components of the antiviral response. Four- to six-week-old Irf3(-/-)Irf5(-/-)Irf7(-/-) triple knockout mice, which produce little interferon α/β, and mice lacking the interferon receptor (Ifnar1(-/-)) developed neurological disease and succumbed to ZIKV infection, whereas single Irf3(-/-), Irf5(-/-), and Mavs(-/-) knockout mice exhibited no overt illness. Ifnar1(-/-) mice sustained high viral loads in the brain and spinal cord, consistent with evidence that ZIKV causes neurodevelopmental defects in human fetuses. The testes of Ifnar1(-/-) mice had the highest viral loads, which is relevant to sexual transmission of ZIKV. This model of ZIKV pathogenesis will be valuable for evaluating vaccines and therapeutics as well as understanding disease pathogenesis. PMID:27066744

  15. A human neurodevelopmental model for Williams syndrome.

    PubMed

    Chailangkarn, Thanathom; Trujillo, Cleber A; Freitas, Beatriz C; Hrvoj-Mihic, Branka; Herai, Roberto H; Yu, Diana X; Brown, Timothy T; Marchetto, Maria C; Bardy, Cedric; McHenry, Lauren; Stefanacci, Lisa; Järvinen, Anna; Searcy, Yvonne M; DeWitt, Michelle; Wong, Wenny; Lai, Philip; Ard, M Colin; Hanson, Kari L; Romero, Sarah; Jacobs, Bob; Dale, Anders M; Dai, Li; Korenberg, Julie R; Gage, Fred H; Bellugi, Ursula; Halgren, Eric; Semendeferi, Katerina; Muotri, Alysson R

    2016-08-18

    Williams syndrome is a genetic neurodevelopmental disorder characterized by an uncommon hypersociability and a mosaic of retained and compromised linguistic and cognitive abilities. Nearly all clinically diagnosed individuals with Williams syndrome lack precisely the same set of genes, with breakpoints in chromosome band 7q11.23 (refs 1-5). The contribution of specific genes to the neuroanatomical and functional alterations, leading to behavioural pathologies in humans, remains largely unexplored. Here we investigate neural progenitor cells and cortical neurons derived from Williams syndrome and typically developing induced pluripotent stem cells. Neural progenitor cells in Williams syndrome have an increased doubling time and apoptosis compared with typically developing neural progenitor cells. Using an individual with atypical Williams syndrome, we narrowed this cellular phenotype to a single gene candidate, frizzled 9 (FZD9). At the neuronal stage, layer V/VI cortical neurons derived from Williams syndrome were characterized by longer total dendrites, increased numbers of spines and synapses, aberrant calcium oscillation and altered network connectivity. Morphometric alterations observed in neurons from Williams syndrome were validated after Golgi staining of post-mortem layer V/VI cortical neurons. This model of human induced pluripotent stem cells fills the current knowledge gap in the cellular biology of Williams syndrome and could lead to further insights into the molecular mechanism underlying the disorder and the human social brain. PMID:27509850

  16. Development of a novel mouse constipation model

    PubMed Central

    Liang, Chao; Wang, Kai-Yue; Yu, Zhi; Xu, Bin

    2016-01-01

    AIM: To establish a novel mouse constipation model. METHODS: Animals were randomly divided into three groups, and intragastrically administered 0-4 °C saline (ice-cold group) or 15-20 °C saline (saline control group) daily for 14 d, or were left untreated (blank control group). Stools were collected 3-24 h after treatment to record the wet and dry weights and the stool form. Intestinal propulsion experiments were carried out and defecation time was measured for six days continuously after suspending treatments. The expressions of PGP9.5 were detected by immunohistochemistry. RESULTS: Based on the percentage of stool weight changes compared with baseline (before irritation) in 9-14 d, stool weight changes were classified into three levels. Each level shows a different body state, which is state I (no change: plus or minus 5%), state II (slightly decreased: 5%-15%) and state III (decreased: 15%-25%). In state III, between day 9-14, the stool weights decreased by 15%-25% compared with the baseline, and changed at a rate > 10% compared with blank control values, and the stools became small and dry. Additionally, intestinal functions degenerated in these animals, and PGP9.5-positive expression markedly decreased in jejunum, ileum and proximal colon myenteric plexus. CONCLUSION: Irritation with ice-cold saline is a stable, repeatable method in building constipation model in mice for exploring the pathogenesis and treatment options of constipation, and the change of stool weight and size may serve as a useful tool to judge a constipation model success or not. PMID:26973418

  17. Characterization of a mouse model of headache.

    PubMed

    Huang, Dongyue; Ren, Lynn; Qiu, Chang-Shen; Liu, Ping; Peterson, Jonathan; Yanagawa, Yuchio; Cao, Yu-Qing

    2016-08-01

    Migraine and other primary headache disorders affect a large population and cause debilitating pain. Establishing animal models that display behavioral correlates of long-lasting and ongoing headache, the most common and disabling symptom of migraine, is vital for the elucidation of disease mechanisms and identification of drug targets. We have developed a mouse model of headache, using dural application of capsaicin along with a mixture of inflammatory mediators (IScap) to simulate the induction of a headache episode. This elicited intermittent head-directed wiping and scratching as well as the phosphorylation of c-Jun N-terminal kinase in trigeminal ganglion neurons. Interestingly, dural application of IScap preferentially induced FOS protein expression in the excitatory but not inhibitory cervical/medullary dorsal horn neurons. The duration of IScap-induced behavior and the number of FOS-positive neurons correlated positively in individual mice; both were reduced to the control level by the pretreatment of antimigraine drug sumatriptan. Dural application of CGRP(8-37), the calcitonin gene-related peptide (CGRP) receptor antagonist, also effectively blocked IScap-induced behavior, which suggests that the release of endogenous CGRP in the dura is necessary for IScap-induced nociception. These data suggest that dural IScap-induced nocifensive behavior in mice may be mechanistically related to the ongoing headache in humans. In addition, dural application of IScap increased resting time in female mice. Taken together, we present the first detailed study using dural application of IScap in mice. This headache model can be applied to genetically modified mice to facilitate research on the mechanisms and therapeutic targets for migraine headache. PMID:27058678

  18. A mouse model of Salmonella typhi infection

    PubMed Central

    Mathur, Ramkumar; Oh, Hyunju; Zhang, Dekai; Park, Sung-Gyoo; Seo, Jin; Koblansky, Alicia; Hayden, Matthew S.; Ghosh, Sankar

    2012-01-01

    Salmonella spp. are gram-negative flagellated bacteria that can cause food and water-borne gastroenteritis and typhoid fever in humans. We now report that flagellin from Salmonella spp. is recognized in mouse intestine by Toll-like receptor 11 (TLR11). Absence of TLR11 renders mice more susceptible to infection by S. typhimurium, with increased dissemination of the bacteria and enhanced lethality. Unlike S. typhimurium, S. typhi, a human obligatory pathogen that causes typhoid fever, is normally unable to infect mice. TLR11 is expressed in mice but not in humans, and remarkably, we find that tlr11−/− mice are efficiently infected with orally-administered S. typhi. We also find that tlr11−/− mice can be immunized against S. typhi. Therefore, tlr11−/− mice represent the first small animal model for the study of the immune response to S. typhi, and for the development of vaccines against this important human pathogen. PMID:23101627

  19. Increased Opioid Dependence in a Mouse Model of Panic Disorder

    PubMed Central

    Gallego, Xavier; Murtra, Patricia; Zamalloa, Teresa; Canals, Josep Maria; Pineda, Joseba; Amador-Arjona, Alejandro; Maldonado, Rafael; Dierssen, Mara

    2009-01-01

    Panic disorder is a highly prevalent neuropsychiatric disorder that shows co-occurrence with substance abuse. Here, we demonstrate that TrkC, the high-affinity receptor for neurotrophin-3, is a key molecule involved in panic disorder and opiate dependence, using a transgenic mouse model (TgNTRK3). Constitutive TrkC overexpression in TgNTRK3 mice dramatically alters spontaneous firing rates of locus coeruleus (LC) neurons and the response of the noradrenergic system to chronic opiate exposure, possibly related to the altered regulation of neurotrophic peptides observed. Notably, TgNTRK3 LC neurons showed an increased firing rate in saline-treated conditions and profound abnormalities in their response to met5-enkephalin. Behaviorally, chronic morphine administration induced a significantly increased withdrawal syndrome in TgNTRK3 mice. In conclusion, we show here that the NT-3/TrkC system is an important regulator of neuronal firing in LC and could contribute to the adaptations of the noradrenergic system in response to chronic opiate exposure. Moreover, our results indicate that TrkC is involved in the molecular and cellular changes in noradrenergic neurons underlying both panic attacks and opiate dependence and support a functional endogenous opioid deficit in panic disorder patients. PMID:20204153

  20. Age-Dependent Specific Changes in Area CA2 of the Hippocampus and Social Memory Deficit in a Mouse Model of the 22q11.2 Deletion Syndrome.

    PubMed

    Piskorowski, Rebecca A; Nasrallah, Kaoutsar; Diamantopoulou, Anastasia; Mukai, Jun; Hassan, Sami I; Siegelbaum, Steven A; Gogos, Joseph A; Chevaleyre, Vivien

    2016-01-01

    Several neuropsychiatric disorders are associated with cognitive and social dysfunction. Postmortem studies of patients with schizophrenia have revealed specific changes in area CA2, a long-overlooked region of the hippocampus recently found to be critical for social memory formation. To examine how area CA2 is altered in psychiatric illness, we used the Df(16)A(+/-) mouse model of the 22q11.2 microdeletion, a genetic risk factor for developing several neuropsychiatric disorders, including schizophrenia. We report several age-dependent CA2 alterations: a decrease in the density of parvalbumin-expressing interneurons, a reduction in the amount of feedforward inhibition, and a change in CA2 pyramidal-neuron intrinsic properties. Furthermore, we found that area CA2 is less plastic in Df(16)A(+/-) mice, making it nearly impossible to evoke action potential firing in CA2 pyramidal neurons. Finally, we show that Df(16)A(+/-) mice display impaired social cognition, providing a potential mechanism and a neural substrate for this impairment in psychiatric disorders. PMID:26748091

  1. Expression of trisomic proteins in Down syndrome model systems.

    PubMed

    Spellman, Claire; Ahmed, Md Mahiuddin; Dubach, Daphne; Gardiner, Katheleen J

    2013-01-10

    Down syndrome (DS) is the most common genetic aberration leading to intellectual disability. DS results from an extra copy of the long arm of human chromosome 21 (HSA21) and the increased expression of trisomic genes due to gene dosage. While expression in DS and DS models has been studied extensively at the RNA level, much less is known about expression of trisomic genes at the protein level. We have used quantitative Western blotting with antibodies to 20 proteins encoded by HSA21 to assess trisomic protein expression in lymphoblastoid cell lines (LCLs) from patients with DS and in brains from two mouse models of DS. These antibodies have recently become available and the 20 proteins largely have not been investigated previously for their potential contributions to the phenotypic features of DS. Twelve proteins had detectable expression in LCLs and three, CCT8, MX1 and PWP2, showed elevated levels in LCLs derived from patients with DS compared with controls. Antibodies against 15 proteins detected bands of appropriate sizes in lysates from mouse brain cortex. Genes for 12 of these proteins are trisomic in the Tc1 mouse model of DS, but only SIM2 and ZNF295 showed elevated expression in Tc1 cortex when compared with controls. Genes for eight of the 15 proteins are trisomic in the Ts65Dn mouse model of DS, but only ZNF294 was over expressed in cortex. Comparison of trisomic gene expression at the protein level with previous reports at the mRNA level showed many inconsistencies. These may be caused by natural inter-individual variability, differences in the age of mice analyzed, or post-transcriptional regulation of gene dosage effects. These antibodies provide resources for further investigation of the molecular basis of intellectual disability in DS. PMID:23103828

  2. Role of FGF/FGFR signaling in skeletal development and homeostasis: learning from mouse models

    PubMed Central

    Su, Nan; Jin, Min; Chen, Lin

    2014-01-01

    Fibroblast growth factor (FGF)/fibroblast growth factor receptor (FGFR) signaling plays essential roles in bone development and diseases. Missense mutations in FGFs and FGFRs in humans can cause various congenital bone diseases, including chondrodysplasia syndromes, craniosynostosis syndromes and syndromes with dysregulated phosphate metabolism. FGF/FGFR signaling is also an important pathway involved in the maintenance of adult bone homeostasis. Multiple kinds of mouse models, mimicking human skeleton diseases caused by missense mutations in FGFs and FGFRs, have been established by knock-in/out and transgenic technologies. These genetically modified mice provide good models for studying the role of FGF/FGFR signaling in skeleton development and homeostasis. In this review, we summarize the mouse models of FGF signaling-related skeleton diseases and recent progresses regarding the molecular mechanisms, underlying the role of FGFs/FGFRs in the regulation of bone development and homeostasis. This review also provides a perspective view on future works to explore the roles of FGF signaling in skeletal development and homeostasis. PMID:26273516

  3. The Oak Ridge Polycystic Kidney Mouse: Modeling Ciliopathies of Mice and Men

    PubMed Central

    Lehman, Jonathan M.; Michaud, Edward J.; Schoeb, Trenton R.; Aydin-Son, Yesim; Miller, Michael; Yoder, Bradley K.

    2009-01-01

    The Oak Ridge Polycystic Kidney (ORPK) mouse was described nearly 14 years ago as a model for human recessive Polycystic Kidney Disease. The ORPK mouse arose through integration of a transgene into an intron of the ift88 gene resulting in a hypomorphic allele (Ift88Tg737Rpw). The Ift88Tg737Rpw mutation impairs intraflagellar transport (IFT), a process required for assembly of motile and immotile cilia. Historically, the primary immotile cilium was thought to have minimal importance for human health; however, a rapidly expanding number of human disorders have now been attributed to ciliary defects. Importantly, many of these phenotypes are present and can be analyzed using the ORPK mouse. In this review, we highlight the research conducted using the OPRK mouse and the phenotypes shared with human cilia disorders. Further, we describe an additional follicular dysplasia phenotype in the ORPK mouse, which alongside the ectodermal dysplasias seen in human Ellis-van Creveld and Sensenbrenner’s syndromes, suggests an unappreciated role for primary cilia in the skin and hair follicle. PMID:18366137

  4. The Oak Ridge Polycystic Kidney mouse: modeling ciliopathies of mice and men.

    SciTech Connect

    Lehman, J M; Michaud III, Edward J; Schoeb, T; Aydin Son, Yesim; Miller, M; Yoder, Bradley

    2008-08-01

    The Oak Ridge Polycystic Kidney (ORPK) mouse was described nearly 14 years ago as a model for human recessive polycystic kidney disease. The ORPK mouse arose through integration of a transgene into an intron of the Ift88 gene resulting in a hypomorphic allele (Ift88Tg737Rpw). The Ift88Tg737Rpw mutation impairs intraflagellar transport (IFT), a process required for assembly of motile and immotile cilia. Historically, the primary immotile cilium was thought to have minimal importance for human health; however, a rapidly expanding number of human disorders have now been attributed to ciliary defects. Importantly, many of these phenotypes are present and can be analyzed using the ORPK mouse. In this review, we highlight the research conducted using the OPRK mouse and the phenotypes shared with human cilia disorders. Furthermore, we describe an additional follicular dysplasia phenotype in the ORPK mouse, which alongside the ectodermal dysplasias seen in human Ellis-van Creveld and Sensenbrenner's syndromes, suggests an unappreciated role for primary cilia in the skin and hair follicle.

  5. Humanized Mouse Models of HIV Infection

    PubMed Central

    Denton, Paul W.; Garcia, J. Victor

    2013-01-01

    Because of the limited tropism of HIV, in vivo modeling of this virus has been almost exclusively limited to other lentiviruses such as SIV that reproduce many important characteristics of HIV infection. However, there are significant genetic and biological differences among lentiviruses and some HIV-specific interventions are not effective against other lentiviruses in non-human hosts. For these reasons much emphasis has recently been placed on developing alternative animal models that support HIV replication and recapitulate key aspects of HIV infection and pathogenesis in humans. Humanized mice, CD34+ hematopoietic progenitor cell transplanted immunodeficient mice and in particular mice also implanted with human thymic/liver tissue (BLT mice) that develop a functional human immune system, have been the focus of a great deal of attention as possible models to study virtually all aspects of HIV biology and pathogenesis. Humanized mice are systemically reconstituted with human lymphoid cells offering rapid, reliable and reproducible experimental systems for HIV research. Peripheral blood of humanized mice can be readily sampled longitudinally to assess reconstitution with human cells and to monitor HIV replication permitting the evaluation of multiple parameters of HIV infection such as viral load levels, CD4+ T cell depletion, immune activation, as well as the effects of therapeutic interventions. Of high relevance to HIV transmission is the extensive characterization and validation of the reconstitution with human lymphoid cells of the female reproductive tract and of the gastrointestinal tract of humanized BLT mice that renders them susceptible to both vaginal and rectal HIV infection. Other important attributes of all types of humanized mice include: 1) their small size and cost that make them broadly accessible; 2) multiple cohorts of humanized mice can be made from multiple human donors and each cohort has identical human cells, permitting control of

  6. Efficient Replication of Severe Acute Respiratory Syndrome Coronavirus in Mouse Cells Is Limited by Murine Angiotensin-Converting Enzyme 2

    PubMed Central

    Li, Wenhui; Greenough, Thomas C.; Moore, Michael J.; Vasilieva, Natalya; Somasundaran, Mohan; Sullivan, John L.; Farzan, Michael; Choe, Hyeryun

    2004-01-01

    Replication of viruses in species other than their natural hosts is frequently limited by entry and postentry barriers. The coronavirus that causes severe acute respiratory syndrome (SARS-CoV) utilizes the receptor angiotensin-converting enzyme 2 (ACE2) to infect cells. Here we compare human, mouse, and rat ACE2 molecules for their ability to serve as receptors for SARS-CoV. We found that, compared to human ACE2, murine ACE2 less efficiently bound the S1 domain of SARS-CoV and supported less-efficient S protein-mediated infection. Rat ACE2 was even less efficient, at near background levels for both activities. Murine 3T3 cells expressing human ACE2 supported SARS-CoV replication, whereas replication was less than 10% as efficient in the same cells expressing murine ACE2. These data imply that a mouse transgenically expressing human ACE2 may be a useful animal model of SARS. PMID:15452268

  7. A canine model of Cohen syndrome: Trapped Neutrophil Syndrome

    PubMed Central

    2011-01-01

    Background Trapped Neutrophil Syndrome (TNS) is a common autosomal recessive neutropenia in Border collie dogs. Results We used a candidate gene approach and linkage analysis to show that the causative gene for TNS is VPS13B. We chose VPS13B as a candidate because of similarities in clinical signs between TNS and Cohen syndrome, in human, such as neutropenia and a typical facial dysmorphism. Linkage analysis using microsatellites close to VPS13B showed positive linkage of the region to TNS. We sequenced each of the 63 exons of VPS13B in affected and control dogs and found that the causative mutation in Border collies is a 4 bp deletion in exon 19 of the largest transcript that results in premature truncation of the protein. Cohen syndrome patients present with mental retardation in 99% of cases, but learning disabilities featured in less than half of TNS affected dogs. It has been implied that loss of the alternate transcript of VPS13B in the human brain utilising an alternate exon, 28, may cause mental retardation. Mice cannot be used to test this hypothesis as they do not express the alternate exon. We show that dogs do express alternate transcripts in the brain utilising an alternate exon homologous to human exon 28. Conclusion Dogs can be used as a model organism to explore the function of the alternately spliced transcript of VPS13B in the brain. TNS in Border collies is the first animal model for Cohen syndrome and can be used to study the disease aetiology. PMID:21605373

  8. Comparative mapping of DNA markers from the familial Alzheimer disease and Down syndrome regions of human chromosome 21 to mouse chromosomes 16 and 17

    SciTech Connect

    Cheng, S.V.; Nadeau, J.H.; Tanzi, R.E.; Watkins, P.C.; Jagadesh, J.; Taylor, B.A.; Haines, J.L.; Sacchi, N.; Gusella, J.F. )

    1988-08-01

    Mouse trisomy 16 has been proposed as an animal model of Down syndrome (DS), since this chromosome contains homologues of several loci from the q22 band of human chromosome 21. The recent mapping of the defect causing familial Alzheimer disease (FAD) and the locus encoding the Alzheimer amyloid {beta} precursor protein (APP) to human chromosome 21 has prompted a more detailed examination of the extent of conservation of this linkage group between the two species. Using anonymous DNA probes and cloned genes from human chromosome 21 in a combination of recombinant inbred and interspecific mouse backcross analyses, the authors have established that the linkage group shared by mouse chromosome 16 includes not only the critical DS region of human chromosome 21 but also the APP gene and FAD-linked markers. Extending from the anonymous DNA locus D21S52 to ETS2, the linkage map of six loci spans 39% recombination in man but only 6.4% recombination in the mouse. A break in synteny occurs distal to ETS2, with the homologue of the human marker D21S56 mapping to mouse chromosome 17. Conservation of the linkage relationships of markers in the FAD region suggests that the murine homologue of the FAD locus probably maps to chromosome 16 and that detailed comparison of the corresponding region in both species could facilitate identification of the primary defect in this disorder. The break in synteny between the terminal portion of human chromosome 21 and mouse chromosome 16 indicates, however, that mouse trisomy 16 may not represent a complete model of DS.

  9. System parameters for erythropoiesis control model: Comparison of normal values in human and mouse model

    NASA Technical Reports Server (NTRS)

    1979-01-01

    The computer model for erythropoietic control was adapted to the mouse system by altering system parameters originally given for the human to those which more realistically represent the mouse. Parameter values were obtained from a variety of literature sources. Using the mouse model, the mouse was studied as a potential experimental model for spaceflight. Simulation studies of dehydration and hypoxia were performed. A comparison of system parameters for the mouse and human models is presented. Aside from the obvious differences expected in fluid volumes, blood flows and metabolic rates, larger differences were observed in the following: erythrocyte life span, erythropoietin half-life, and normal arterial pO2.

  10. Automated measurement of mouse apolipoprotein B: convenient screening tool for mouse models of atherosclerosis.

    PubMed

    Levine, D M; Williams, K J

    1997-04-01

    Although mice are commonly used for studies of atherosclerosis, investigators have had no convenient way to quantify apolipoprotein (apo) B, the major protein of atherogenic lipoproteins, in this model. We now report an automated immunoturbidimetric assay for mouse apo B with an NCCLS imprecision study CV < 5%. Added hemoglobin up to 50 g/L did not interfere with the assay, nor did one freeze-thaw cycle of serum samples. Assay linearity extends to apo B concentrations of 325 mg/L. We have used the assay to determine serum apo B concentrations under several atherogenic conditions, including the apo E "knock-out" genotype and treatment with a high-cholesterol diet. Our assay can be used to survey inbred mouse strains for variants in apo B concentrations or regulation. Moreover, the mouse can now be used as a convenient small-animal model to screen compounds that may lower apo B concentrations. PMID:9105271

  11. Behavioral phenotypes of genetic mouse models of autism

    PubMed Central

    Kazdoba, T. M.; Leach, P. T.; Crawley, J. N.

    2016-01-01

    More than a hundred de novo single gene mutations and copy-number variants have been implicated in autism, each occurring in a small subset of cases. Mutant mouse models with syntenic mutations offer research tools to gain an understanding of the role of each gene in modulating biological and behavioral phenotypes relevant to autism. Knockout, knockin and transgenic mice incorporating risk gene mutations detected in autism spectrum disorder and comorbid neurodevelopmental disorders are now widely available. At present, autism spectrum disorder is diagnosed solely by behavioral criteria. We developed a constellation of mouse behavioral assays designed to maximize face validity to the types of social deficits and repetitive behaviors that are central to an autism diagnosis. Mouse behavioral assays for associated symptoms of autism, which include cognitive inflexibility, anxiety, hyperactivity, and unusual reactivity to sensory stimuli, are frequently included in the phenotypic analyses. Over the past 10 years, we and many other laboratories around the world have employed these and additional behavioral tests to phenotype a large number of mutant mouse models of autism. In this review, we highlight mouse models with mutations in genes that have been identified as risk genes for autism, which work through synaptic mechanisms and through the mTOR signaling pathway. Robust, replicated autism-relevant behavioral outcomes in a genetic mouse model lend credence to a causal role for specific gene contributions and downstream biological mechanisms in the etiology of autism. PMID:26403076

  12. Development and testing of a mouse simulated space flight model

    NASA Technical Reports Server (NTRS)

    Sonnenfeld, Gerald

    1987-01-01

    The development and testing of a mouse model for simulating some aspects of weightlessness that occurs during space flight, and the carrying out of immunological experiments on animals undergoing space flight is examined. The mouse model developed was an antiorthostatic, hypokinetic, hypodynamic suspension model similar to one used with rats. The study was divided into two parts. The first involved determination of which immunological parameters should be observed on animals flown during space flight or studied in the suspension model. The second involved suspending mice and determining which of those immunological parameters were altered by the suspension. Rats that were actually flown in Space Shuttle SL-3 were used to test the hypotheses.

  13. A new HCV mouse model on the block.

    PubMed

    Tawar, Rajiv G; Mailly, Laurent; Baumert, Thomas F

    2014-10-01

    The investigation of virus-induced liver disease and hepatocellular carcinoma needs small animal models modeling hepatitis C virus (HCV) infection and liver disease biology. A recent study published in Cell Research reports a novel mouse model which is permissive for chronic HCV infection and shows chronic liver injury including inflammation, steatosis and fibrosis. PMID:25257465

  14. Genomic responses in mouse models poorly mimic human inflammatory diseases

    PubMed Central

    Seok, Junhee; Warren, H. Shaw; Cuenca, Alex G.; Mindrinos, Michael N.; Baker, Henry V.; Xu, Weihong; Richards, Daniel R.; McDonald-Smith, Grace P.; Gao, Hong; Hennessy, Laura; Finnerty, Celeste C.; López, Cecilia M.; Honari, Shari; Moore, Ernest E.; Minei, Joseph P.; Cuschieri, Joseph; Bankey, Paul E.; Johnson, Jeffrey L.; Sperry, Jason; Nathens, Avery B.; Billiar, Timothy R.; West, Michael A.; Jeschke, Marc G.; Klein, Matthew B.; Gamelli, Richard L.; Gibran, Nicole S.; Brownstein, Bernard H.; Miller-Graziano, Carol; Calvano, Steve E.; Mason, Philip H.; Cobb, J. Perren; Rahme, Laurence G.; Lowry, Stephen F.; Maier, Ronald V.; Moldawer, Lyle L.; Herndon, David N.; Davis, Ronald W.; Xiao, Wenzhong; Tompkins, Ronald G.; Abouhamze, Amer; Balis, Ulysses G. J.; Camp, David G.; De, Asit K.; Harbrecht, Brian G.; Hayden, Douglas L.; Kaushal, Amit; O’Keefe, Grant E.; Kotz, Kenneth T.; Qian, Weijun; Schoenfeld, David A.; Shapiro, Michael B.; Silver, Geoffrey M.; Smith, Richard D.; Storey, John D.; Tibshirani, Robert; Toner, Mehmet; Wilhelmy, Julie; Wispelwey, Bram; Wong, Wing H

    2013-01-01

    A cornerstone of modern biomedical research is the use of mouse models to explore basic pathophysiological mechanisms, evaluate new therapeutic approaches, and make go or no-go decisions to carry new drug candidates forward into clinical trials. Systematic studies evaluating how well murine models mimic human inflammatory diseases are nonexistent. Here, we show that, although acute inflammatory stresses from different etiologies result in highly similar genomic responses in humans, the responses in corresponding mouse models correlate poorly with the human conditions and also, one another. Among genes changed significantly in humans, the murine orthologs are close to random in matching their human counterparts (e.g., R2 between 0.0 and 0.1). In addition to improvements in the current animal model systems, our study supports higher priority for translational medical research to focus on the more complex human conditions rather than relying on mouse models to study human inflammatory diseases. PMID:23401516

  15. Phenotypic and pathologic evaluation of the myd mouse. A candidate model for facioscapulohumeral dystrophy

    SciTech Connect

    Mathews, K.D.; Rapisarda, D.; Bailey, H.L.

    1995-07-01

    Facioscapulohumeral dystrophy (FSHD) is an autosomal dominant disease of unknown pathogenesis which is characterized by weakness of the face and shoulder girdle. It is associated with a sensorineural hearing loss which may be subclinical. FSHD has been mapped to the distalmost portion of 4q35, although the gene has not yet been identified. Distal 4q has homology with a region of mouse chromosome 8 to which a mouse mutant, myodystrophy (myd), has been mapped. Muscle from homozygotes for the myd mutation appears dystrophic, showing degenerating and regenerating fibers, inflammatory infiltrates, central nuclei, and variation in fiber size. Brainstem auditory evoked potentials reveal a sensorineural hearing loss in myd homozygotes. Based on the homologous genetic map locations, and the phenotypic syndrome of dystrophic muscle with sensorineural hearing loss, we suggest that myd represents an animal model for the human disease FSHD. 28 refs., 4 figs.

  16. Mouse Models for Assessing Protein Immunogenicity: Lessons and Challenges.

    PubMed

    Jiskoot, Wim; Kijanka, Grzegorz; Randolph, Theodore W; Carpenter, John F; Koulov, Atanas V; Mahler, Hanns-Christian; Joubert, Marisa K; Jawa, Vibha; Narhi, Linda O

    2016-05-01

    The success of clinical and commercial therapeutic proteins is rapidly increasing, but their potential immunogenicity is an ongoing concern. Most of the studies that have been conducted over the past few years to examine the importance of various product-related attributes (in particular several types of aggregates and particles) and treatment regimen (such as dose, dosing schedule, and route of administration) in the development of unwanted immune responses have utilized one of a variety of mouse models. In this review, we discuss the utility and drawbacks of different mouse models that have been used for this purpose. Moreover, we summarize the lessons these models have taught us and some of the challenges they present. Finally, we provide recommendations for future research utilizing mouse models to improve our understanding of critical factors that may contribute to protein immunogenicity. PMID:27044944

  17. CML Mouse Model Generated from Leukemia Stem Cells.

    PubMed

    Hu, Yiguo

    2016-01-01

    Chronic myeloid leukemia (CML) is a myeloproliferative disorder with a high number of well-differentiated neutrophils in peripheral blood and myeloid cells in bone marrow (BM). CML is derived from the hematopoietic stem cells (HSCs) with the Philadelphia chromosome (Ph(+), t(9;22)-(q34;q11)), resulting in generating a fusion oncogene, BCR/ABL1. HSCs with Ph(+) are defined as leukemia stem cells (LSCs), a subpopulation cell at the apex of hierarchies in leukemia cells and responsible for the disease continuous propagation. Several kinds of CML models have been developed to reveal the mechanism of CML pathogenesis and evaluate therapeutic drugs in the past three decades. Here, we describe the procedures to generate a CML mouse model by introducing BCR/ABL1 into Lin(-)Sca1(+) cKit(+) population cells purified from mouse bone marrow. In CML retroviral transduction/transplantation mouse models, this modified model can mimic CML pathogenesis on high fidelity. PMID:27581136

  18. Increased survival following tumorigenesis in Ts65Dn mice that model Down syndrome.

    PubMed

    Yang, Annan; Reeves, Roger H

    2011-05-15

    Epidemiologic results tend to suggest that adults with Down syndrome have a reduced incidence of cancer, but some studies have reached the opposite conclusion. In this study, we offer direct biological evidence in support of the notion that Down syndrome reduces incidence of multiple types of cancer. Previous studies showed that introduction of the Apc(Min) mutation into the Ts65Dn mouse model of Down syndrome by interbreeding caused formation of intestinal adenomas at a significantly reduced incidence compared with control (euploid) animals that did not have trisomy. To a large degree, this reduction was determined to reflect an increased dosage of the Ets2 tumor repressor gene due to trisomy. Studies of tumor grafts using Ts65Dn suggested angiogenesis as a mechanism that mediated reduced tumor growth, metastasis, and mortality in individuals with Down syndrome. To confirm and extend these findings, we employed the complex cancer mouse model NPcis, which is heterozygous for the Trp53 and Nf1 genes and through LOH develops lymphomas, sarcomas, or carcinomas with 100% penetrance. In this aggressive model, trisomy did not prevent cancer, but it nevertheless extended host survival relative to euploid littermates. However, protection in this case was not attributable to either Ets2 dosage or to reduced angiogenesis. Together, our findings indicate that the genetic complexity underlying Down syndrome supports multiple mechanisms that contribute to reduced mortality from cancer. PMID:21467166

  19. Intracerebral hemorrhage in mouse models: therapeutic interventions and functional recovery

    PubMed Central

    Carmichael, S. Thomas

    2014-01-01

    There has been strong pre-clinical research on mechanisms of initial cell death and tissue injury in intracerebral hemorrhage (ICH). This data has led to the evaluation of several therapeutics for neuroprotection or the mitigation of early tissue damage. Most of these studies have been done in the rat. Also, there has been little study of the mechanisms of tissue repair and recovery. This review examines the testing of candidate therapeutics in mouse models of ICH for their effect on tissue protection and repair. This review will help the readers compare it to the extensively researched rat model of ICH and thus enhance work that are pending in mouse model. PMID:24810632

  20. A bovine model for polycystic ovary syndrome

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Polycystic ovary syndrome (PCOS) results in the greatest single cause of anovulatory infertility in reproductive age women (affecting 5-10%). Previously, research groups have created animal models utilizing non-human primates and sheep to better understand the mechanisms involved in PCOS. However, c...

  1. Mouse models for understanding human developmental anomalies

    SciTech Connect

    Generoso, W.M.

    1989-01-01

    The mouse experimental system presents an opportunity for studying the nature of the underlying mutagenic damage and the molecular pathogenesis of this class of anomalies by virtue of the accessibility of the zygote and its descendant blastomeres. Such studies could contribute to the understanding of the etiology of certain sporadic but common human malformations. The vulnerability of the zygotes to mutagens as demonstrated in the studies described in this report should be a major consideration in chemical safety evaluation. It raises questions regarding the danger to human zygotes when the mother is exposed to drugs and environmental chemicals.

  2. Biochemical and behavioural phenotyping of a mouse model for GAMT deficiency.

    PubMed

    Torremans, An; Marescau, Bart; Possemiers, Ilse; Van Dam, Debby; D'Hooge, Rudi; Isbrandt, Dirk; De Deyn, Peter Paul

    2005-04-15

    Deficiency of guanidinoacetate N-methyltransferase (GAMT) is the first described creatine (CT) deficiency syndrome in man, biochemically characterized by accumulation of guanidinoacetic acid (GAA) and depletion of CT. Patients exhibit severe developmental and muscular problems. We created a mouse model for GAMT deficiency, which exerts biochemical changes comparable with those found in human GAMT-deficient subjects. CT and creatinine (CTN) levels are significantly decreased and GAA is increased in knockout (KO) mice. In patients, other guanidino compounds (GCs) appear to be altered as well, which may also contribute to the symptomatology. Extensive evaluation of GCs levels in the GAMT mouse model was therefore considered appropriate. Concentrations of 13 GCs in plasma, 24-h urine, brain and muscle of GAMT mice were measured. We also report on the detailed behavioural characterization of this model for GAMT deficiency. Besides an increase of GAA and a decrease of CT and CTN in plasma, 24-h urine, brain and muscle of KO mice, we observed a significant increase of other GCs in brain and muscle that was sometimes reflected in plasma and/or urine. KO mice displayed mild cognitive impairment. In general, it could be concluded that the GAMT mouse model is very useful for biochemical research of GAMT deficiency, but shows only a mild cognitive deficit. PMID:15792821

  3. Mouse Xenograft Model for Mesothelioma | NCI Technology Transfer Center | TTC

    Cancer.gov

    The National Cancer Institute is seeking parties interested in collaborative research to co-develop, evaluate, or commercialize a new mouse model for monoclonal antibodies and immunoconjugates that target malignant mesotheliomas. Applications of the technology include models for screening compounds as potential therapeutics for mesothelioma and for studying the pathology of mesothelioma.

  4. Generating Transgenic Mouse Models for Studying Celiac Disease.

    PubMed

    Ju, Josephine M; Marietta, Eric V; Murray, Joseph A

    2015-01-01

    This chapter provides a brief overview of current animal models for studying celiac disease, with a focus on generating HLA transgenic mouse models. Human Leukocyte Antigen class II molecules have been a particular target for transgenic mice due to their tight association with celiac disease, and a number of murine models have been developed which had the endogenous MHC class II genes replaced with insertions of disease susceptible HLA class II alleles DQ2 or DQ8. Additionally, transgenic mice that overexpress interleukin-15 (IL-15), a key player in the inflammatory cascade that leads to celiac disease, have also been generated to model a state of chronic inflammation. To explore the contribution of specific bacteria in gluten-sensitive enteropathy, the nude mouse and rat models have been studied in germ-free facilities. These reductionist mouse models allow us to address single factors thought to have crucial roles in celiac disease. No single model has incorporated all of the multiple factors that make up celiac disease. Rather, these mouse models can allow the functional interrogation of specific components of the many stages of, and contributions to, the pathogenic mechanisms that will lead to gluten-dependent enteropathy. Overall, the tools for animal studies in celiac disease are many and varied, and provide ample space for further creativity as well as to characterize the complete and complex pathogenesis of celiac disease. PMID:26498609

  5. Modeling Cutaneous Squamous Carcinoma Development in the Mouse

    PubMed Central

    Huang, Phillips Y.; Balmain, Allan

    2014-01-01

    Cutaneous squamous cell carcinoma (SCC) is one of the most common cancers in Caucasian populations and is associated with a significant risk of morbidity and mortality. The classic mouse model for studying SCC involves two-stage chemical carcinogenesis, which has been instrumental in the evolution of the concept of multistage carcinogenesis, as widely applied to both human and mouse cancers. Much is now known about the sequence of biological and genetic events that occur in this skin carcinogenesis model and the factors that can influence the course of tumor development, such as perturbations in the oncogene/tumor-suppressor signaling pathways involved, the nature of the target cell that acquires the first genetic hit, and the role of inflammation. Increasingly, studies of tumor-initiating cells, malignant progression, and metastasis in mouse skin cancer models will have the potential to inform future approaches to treatment and chemoprevention of human squamous malignancies. PMID:25183851

  6. Rat Model of Parkes Weber Syndrome.

    PubMed

    Bojakowski, Krzysztof; Janusz, Gabriela; Grabowska, Iwona; Zegrocka-Stendel, Oliwia; Surowiecka-Pastewka, Agnieszka; Kowalewska, Magdalena; Maciejko, Dorota; Koziak, Katarzyna

    2015-01-01

    The Parkes Weber syndrome is a congenital vascular malformation, characterized by varicose veins, arterio-venous fistulas and overgrown limbs. No broadly accepted animal model of Parkes Weber syndrome has been described. We created side-to-side arterio-venous fistula between common femoral vessels with proximal non-absorbable ligature on common femoral vein limiting the enlargement of the vein diameter in Wistar rats. Contralateral limb was sham operated. Invasive blood pressure measurements in both iliac and inferior cava veins were performed in rats 30 days after fistula creation. Tight circumference and femoral bone length were measured. Histopathology and morphology of soleus muscle, extensor digitorum longus muscle, and the common femoral vessel were analyzed. 30 days following arterio-venous fistula creation, a statistically significant elevation of blood pressure in common iliac vein and limb overgrowth was observed. Limb enlargement was caused by muscle overgrowth, varicose veins formation and bone elongation. Arterio-venous fistula with proximal outflow limitation led to significant increase of femoral vein circumference and venous wall thickness. Our study indicates that the described rat model mimics major clinical features characteristic for the human Parkes Weber syndrome: presence of arterio-venous fistula, venous hypertension and dilatation, varicose veins formation, and the limb hypertrophy. We reveal that limb overgrowth is caused by bone elongation, muscle hypertrophy, and venous dilatation. The newly established model will permit detailed studies on the mechanisms underlying the disease and on the efficacy of novel therapeutic strategies for the Parkes Weber syndrome treatment. PMID:26217941

  7. Rat Model of Parkes Weber Syndrome

    PubMed Central

    Bojakowski, Krzysztof; Janusz, Gabriela; Grabowska, Iwona; Zegrocka-Stendel, Oliwia; Surowiecka-Pastewka, Agnieszka; Kowalewska, Magdalena; Maciejko, Dorota; Koziak, Katarzyna

    2015-01-01

    The Parkes Weber syndrome is a congenital vascular malformation, characterized by varicose veins, arterio-venous fistulas and overgrown limbs. No broadly accepted animal model of Parkes Weber syndrome has been described. We created side-to-side arterio-venous fistula between common femoral vessels with proximal non-absorbable ligature on common femoral vein limiting the enlargement of the vein diameter in Wistar rats. Contralateral limb was sham operated. Invasive blood pressure measurements in both iliac and inferior cava veins were performed in rats 30 days after fistula creation. Tight circumference and femoral bone length were measured. Histopathology and morphology of soleus muscle, extensor digitorum longus muscle, and the common femoral vessel were analyzed. 30 days following arterio-venous fistula creation, a statistically significant elevation of blood pressure in common iliac vein and limb overgrowth was observed. Limb enlargement was caused by muscle overgrowth, varicose veins formation and bone elongation. Arterio-venous fistula with proximal outflow limitation led to significant increase of femoral vein circumference and venous wall thickness. Our study indicates that the described rat model mimics major clinical features characteristic for the human Parkes Weber syndrome: presence of arterio-venous fistula, venous hypertension and dilatation, varicose veins formation, and the limb hypertrophy. We reveal that limb overgrowth is caused by bone elongation, muscle hypertrophy, and venous dilatation. The newly established model will permit detailed studies on the mechanisms underlying the disease and on the efficacy of novel therapeutic strategies for the Parkes Weber syndrome treatment. PMID:26217941

  8. MouseNet v2: a database of gene networks for studying the laboratory mouse and eight other model vertebrates

    PubMed Central

    Kim, Eiru; Hwang, Sohyun; Kim, Hyojin; Shim, Hongseok; Kang, Byunghee; Yang, Sunmo; Shim, Jae Ho; Shin, Seung Yeon; Marcotte, Edward M.; Lee, Insuk

    2016-01-01

    Laboratory mouse, Mus musculus, is one of the most important animal tools in biomedical research. Functional characterization of the mouse genes, hence, has been a long-standing goal in mammalian and human genetics. Although large-scale knockout phenotyping is under progress by international collaborative efforts, a large portion of mouse genome is still poorly characterized for cellular functions and associations with disease phenotypes. A genome-scale functional network of mouse genes, MouseNet, was previously developed in context of MouseFunc competition, which allowed only limited input data for network inferences. Here, we present an improved mouse co-functional network, MouseNet v2 (available at http://www.inetbio.org/mousenet), which covers 17 714 genes (>88% of coding genome) with 788 080 links, along with a companion web server for network-assisted functional hypothesis generation. The network database has been substantially improved by large expansion of genomics data. For example, MouseNet v2 database contains 183 co-expression networks inferred from 8154 public microarray samples. We demonstrated that MouseNet v2 is predictive for mammalian phenotypes as well as human diseases, which suggests its usefulness in discovery of novel disease genes and dissection of disease pathways. Furthermore, MouseNet v2 database provides functional networks for eight other vertebrate models used in various research fields. PMID:26527726

  9. MOUSE MODELS OF ARRHYTHMOGENIC CARDIOVASCULAR DISEASE: CHALLENGES AND OPPORTUNITIES

    PubMed Central

    Nerbonne, Jeanne M.

    2014-01-01

    Arrhythmogenic cardiovascular disease is associated with significant morbidity and mortality and, in spite of therapeutic advances, remains an enormous public health burden. The scope of this problem motivates efforts to delineate the molecular, cellular and systemic mechanisms underlying increased arrhythmia risk in inherited and acquired cardiac and systemic disease. The mouse is used increasingly in these efforts owing to the ease with which genetic strategies can be exploited and mechanisms can be probed. The question then arises whether the mouse has proven to be a useful model system to delineate arrhythmogenic cardiovascular disease mechanisms. Rather than trying to provide a definite answer, the goal here is to consider the issues that arise when using mouse models and to highlight the opportunities. PMID:24632325

  10. 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

  11. Development and testing of a mouse simulated space flight model

    NASA Technical Reports Server (NTRS)

    Sonnenfeld, G.

    1985-01-01

    The development and testing of a mouse model for simulating some aspects of weightlessness that occur during space flight, and the carrying out of immunological flight experiments on animals was discussed. The mouse model is an antiorthostatic, hypokinetic, hypodynamic suspension model similar to the one used with rats. It is shown that this murine model yield similar results to the rat model of antiorthostatic suspension for simulating some aspects of weightlessness. It is also shown that mice suspended in this model have decreased interferon-alpha/beta production as compared to control, nonsuspended mice or to orthostatically suspended mice. It is suggested that the conditions occuring during space flight could possibly affect interferon production. The regulatory role of interferon in nonviral diseases is demonstrated including several bacterial and protozoan infections indicating the great significance of interferon in resistance to many types of infectious diseases.

  12. CHARACTERIZATION OF AEROMONAS VIRULENCE USING AN IMMUNOCOMPROMISED MOUSE MODEL

    EPA Science Inventory

    An immunocompromised mouse model was used to characterize Aeromonas strains for their ability to cause opportunistic, extraintestinal infections. A total of 34 isolates of Aeromonas (A. hydrophila [n = 12]), A. veronii biotype sobria [n = 7], A. caviae [n = 4], A. enchelia [n = 4...

  13. Retinal fundus imaging in mouse models of retinal diseases.

    PubMed

    Alex, Anne F; Heiduschka, Peter; Eter, Nicole

    2013-01-01

    The development of in vivo retinal fundus imaging in mice has opened a new research horizon, not only in ophthalmic research. The ability to monitor the dynamics of vascular and cellular changes in pathological conditions, such as neovascularization or degeneration, longitudinally without the need to sacrifice the mouse, permits longer observation periods in the same animal. With the application of the high-resolution confocal scanning laser ophthalmoscopy in experimental mouse models, access to a large spectrum of imaging modalities in vivo is provided. PMID:23150359

  14. Mouse models of acute, chemical itch and pain in humans

    PubMed Central

    LaMotte, Robert H.; Shimada, Steven G.; Sikand, Parul

    2011-01-01

    In psychophysical experiments, humans use different verbal responses to pruritic and algesic chemical stimuli to indicate the different qualities of sensation they feel. A major challenge for behavioral models in the mouse of chemical itch and pain in humans is to devise experimental protocols that provide the opportunity for the animal to exhibit a multiplicity of responses as well. One basic criterion is that chemicals that evoke primarily itch or pain in humans should elicit different types of responses when applied in the same way to the mouse. Meeting this criterion is complicated by the fact that the type of behavioral responses exhibited by the mouse depends in part on the site of chemical application such as the nape of the neck which evokes only scratching with the hind paw vs. the hind limb which elicits licking and biting. Here, we review to what extent mice behaviorally differentiate chemicals that elicit itch vs. pain in humans. PMID:21929688

  15. Protein Delivery of an Artificial Transcription Factor Restores Widespread Ube3a Expression in an Angelman Syndrome Mouse Brain.

    PubMed

    Bailus, Barbara J; Pyles, Benjamin; McAlister, Michelle M; O'Geen, Henriette; Lockwood, Sarah H; Adams, Alexa N; Nguyen, Jennifer Trang T; Yu, Abigail; Berman, Robert F; Segal, David J

    2016-03-01

    Angelman syndrome (AS) is a neurological genetic disorder caused by loss of expression of the maternal copy of UBE3A in the brain. Due to brain-specific genetic imprinting at this locus, the paternal UBE3A is silenced by a long antisense transcript. Inhibition of the antisense transcript could lead to unsilencing of paternal UBE3A, thus providing a therapeutic approach for AS. However, widespread delivery of gene regulators to the brain remains challenging. Here, we report an engineered zinc finger-based artificial transcription factor (ATF) that, when injected i.p. or s.c., crossed the blood-brain barrier and increased Ube3a expression in the brain of an adult mouse model of AS. The factor displayed widespread distribution throughout the brain. Immunohistochemistry of both the hippocampus and cerebellum revealed an increase in Ube3a upon treatment. An ATF containing an alternative DNA-binding domain did not activate Ube3a. We believe this to be the first report of an injectable engineered zinc finger protein that can cause widespread activation of an endogenous gene in the brain. These observations have important implications for the study and treatment of AS and other neurological disorders. PMID:26727042

  16. Protein Delivery of an Artificial Transcription Factor Restores Widespread Ube3a Expression in an Angelman Syndrome Mouse Brain

    PubMed Central

    Bailus, Barbara J; Pyles, Benjamin; McAlister, Michelle M; O'Geen, Henriette; Lockwood, Sarah H; Adams, Alexa N; Nguyen, Jennifer Trang T; Yu, Abigail; Berman, Robert F; Segal, David J

    2016-01-01

    Angelman syndrome (AS) is a neurological genetic disorder caused by loss of expression of the maternal copy of UBE3A in the brain. Due to brain-specific genetic imprinting at this locus, the paternal UBE3A is silenced by a long antisense transcript. Inhibition of the antisense transcript could lead to unsilencing of paternal UBE3A, thus providing a therapeutic approach for AS. However, widespread delivery of gene regulators to the brain remains challenging. Here, we report an engineered zinc finger-based artificial transcription factor (ATF) that, when injected i.p. or s.c., crossed the blood–brain barrier and increased Ube3a expression in the brain of an adult mouse model of AS. The factor displayed widespread distribution throughout the brain. Immunohistochemistry of both the hippocampus and cerebellum revealed an increase in Ube3a upon treatment. An ATF containing an alternative DNA-binding domain did not activate Ube3a. We believe this to be the first report of an injectable engineered zinc finger protein that can cause widespread activation of an endogenous gene in the brain. These observations have important implications for the study and treatment of AS and other neurological disorders. PMID:26727042

  17. CCDC88A mutations cause PEHO-like syndrome in humans and mouse

    PubMed Central

    Nahorski, Michael S.; Asai, Masato; Wakeling, Emma; Parker, Alasdair; Asai, Naoya; Canham, Natalie; Holder, Susan E.; Chen, Ya-Chun; Dyer, Joshua

    2016-01-01

    Progressive encephalopathy with oedema, hypsarrhythmia and optic atrophy (PEHO) syndrome is a rare Mendelian phenotype comprising severe retardation, early onset epileptic seizures, optic nerve/cerebellar atrophy, pedal oedema, and early death. Atypical cases are often known as PEHO-like, and there is an overlap with ‘early infantile epileptic encephalopathy’. PEHO is considered to be recessive, but surprisingly since initial description in 1991, no causative recessive gene(s) have been described. Hence, we report a multiplex consanguineous family with the PEHO phenotype where affected individuals had a homozygous frame-shift deletion in CCDC88A (c.2313delT, p.Leu772*ter). Analysis of cDNA extracted from patient lymphocytes unexpectedly failed to show non-sense mediated decay, and we demonstrate that the mutation produces a truncated protein lacking the crucial C-terminal half of CCDC88A (girdin). To further investigate the possible role of CCDC88A in human neurodevelopment we re-examined the behaviour and neuroanatomy of Ccdc88a knockout pups. These mice had mesial-temporal lobe epilepsy, microcephaly and corpus callosum deficiency, and by postnatal Day 21, microcephaly; the mice died at an early age. As the mouse knockout phenotype mimics the human PEHO phenotype this suggests that loss of CCDC88A is a cause of the PEHO phenotype, and that CCDC88A is essential for multiple aspects of normal human neurodevelopment. PMID:26917597

  18. Teratogenic effects of amniotic sac puncture: a mouse model.

    PubMed Central

    MacIntyre, D J; Chang, H H; Kaufman, M H

    1995-01-01

    The possibility of an association between chorionic villus sampling (cvs) and limb abnormalities has prompted a review of the relevant experimental data. Although a vascular aetiology is favoured by many at present, the possibility exists that a proportion of cases may be caused by oligohydramnios secondary to inadvertent amniotic sac puncture. A mouse model of amniotic puncture syndrome has been developed to study the craniofacial and limb abnormalities produced by this procedure. Pregnant mice were anaesthetised and a laparotomy performed. One uterine horn was exteriorised, and the amniotic sacs punctured through the wall of the uterus with either a 21 gauge or a 25 gauge needle. The conceptuses in the contralateral uterine horn acted as controls. The mice were all killed on d 19 of pregnancy (day of finding a vaginal plug = d 1 of pregnancy) by cervical dislocation, and the morphological features of the embryos examined in detail. In a preliminary study, amniotic sac puncture was carried out on d 12, 13, 14, 15 or 16 of pregnancy, with either a 21 or a 25 gauge needle. Since the highest rates of palatal defects and limb deformities were observed following amniotic sac puncture using a 21 gauge needle, when this procedure was carried out on either d 13 or 14 of pregnancy, the main study was undertaken using a 21 gauge needle on these two days of pregnancy. Of 102 embryos in which amniotic sac puncture was carried out on d 13, 53% survived to d 19. Of the latter, 35% had a cleft palate, 61% had one or more morphologically abnormal limbs, and 43% had an abnormal tail. When amniotic sac puncture was carried out on d 14 of pregnancy, of 83 embryos subjected to this procedure, 81% survived to d 19. Of the latter, 27% had a cleft palate, 39% had one or more morphologically abnormal limbs, and 19% had an abnormal tail. In the controls, of 86 and 61 embryos isolated respectively from the d 13 and 14 mice, the survival rates were 97 and 90%, respectively. Palatal, limb

  19. Cell-autonomous progeroid changes in conditional mouse models for repair endonuclease XPG deficiency

    DOE PAGESBeta

    Barnhoorn, Sander; Uittenboogaard, Lieneke M.; Jaarsma, Dick; Vermeij, Wilbert P.; Tresini, Maria; Weymaere, Michael; Menoni, Hervé; Brandt, Renata M. C.; de Waard, Monique C.; Botter, Sander M.; et al

    2014-10-09

    As part of the Nucleotide Excision Repair (NER) process, the endonuclease XPG is involved in repair of helix-distorting DNA lesions, but the protein has also been implicated in several other DNA repair systems, complicating genotype-phenotype relationship in XPG patients. Defects in XPG can cause either the cancer-prone condition xeroderma pigmentosum (XP) alone, or XP combined with the severe neurodevelopmental disorder Cockayne Syndrome (CS), or the infantile lethal cerebro-oculo-facio-skeletal (COFS) syndrome, characterized by dramatic growth failure, progressive neurodevelopmental abnormalities and greatly reduced life expectancy. Here, we present a novel (conditional) Xpg-/- mouse model which—in a C57BL6/FVB F1 hybrid genetic background—displays manymore » progeroid features, including cessation of growth, loss of subcutaneous fat, kyphosis, osteoporosis, retinal photoreceptor loss, liver aging, extensive neurodegeneration, and a short lifespan of 4–5 months. We show that deletion of XPG specifically in the liver reproduces the progeroid features in the liver, yet abolishes the effect on growth or lifespan. In addition, specific XPG deletion in neurons and glia of the forebrain creates a progressive neurodegenerative phenotype that shows many characteristics of human XPG deficiency. Our findings therefore exclude that both the liver as well as the neurological phenotype are a secondary consequence of derailment in other cell types, organs or tissues (e.g. vascular abnormalities) and support a cell-autonomous origin caused by the DNA repair defect itself. In addition they allow the dissection of the complex aging process in tissue- and cell-type-specific components. Moreover, our data highlight the critical importance of genetic background in mouse aging studies, establish the Xpg-/- mouse as a valid model for the severe form of human XPG patients and segmental accelerated aging, and strengthen the link between DNA damage and aging.« less

  20. Cell-Autonomous Progeroid Changes in Conditional Mouse Models for Repair Endonuclease XPG Deficiency

    PubMed Central

    Vermeij, Wilbert P.; Tresini, Maria; Weymaere, Michael; Menoni, Hervé; Brandt, Renata M. C.; de Waard, Monique C.; Botter, Sander M.; Sarker, Altaf H.; Jaspers, Nicolaas G. J.; van der Horst, Gijsbertus T. J.; Cooper, Priscilla K.; Hoeijmakers, Jan H. J.; van der Pluijm, Ingrid

    2014-01-01

    As part of the Nucleotide Excision Repair (NER) process, the endonuclease XPG is involved in repair of helix-distorting DNA lesions, but the protein has also been implicated in several other DNA repair systems, complicating genotype-phenotype relationship in XPG patients. Defects in XPG can cause either the cancer-prone condition xeroderma pigmentosum (XP) alone, or XP combined with the severe neurodevelopmental disorder Cockayne Syndrome (CS), or the infantile lethal cerebro-oculo-facio-skeletal (COFS) syndrome, characterized by dramatic growth failure, progressive neurodevelopmental abnormalities and greatly reduced life expectancy. Here, we present a novel (conditional) Xpg−/− mouse model which -in a C57BL6/FVB F1 hybrid genetic background- displays many progeroid features, including cessation of growth, loss of subcutaneous fat, kyphosis, osteoporosis, retinal photoreceptor loss, liver aging, extensive neurodegeneration, and a short lifespan of 4–5 months. We show that deletion of XPG specifically in the liver reproduces the progeroid features in the liver, yet abolishes the effect on growth or lifespan. In addition, specific XPG deletion in neurons and glia of the forebrain creates a progressive neurodegenerative phenotype that shows many characteristics of human XPG deficiency. Our findings therefore exclude that both the liver as well as the neurological phenotype are a secondary consequence of derailment in other cell types, organs or tissues (e.g. vascular abnormalities) and support a cell-autonomous origin caused by the DNA repair defect itself. In addition they allow the dissection of the complex aging process in tissue- and cell-type-specific components. Moreover, our data highlight the critical importance of genetic background in mouse aging studies, establish the Xpg−/− mouse as a valid model for the severe form of human XPG patients and segmental accelerated aging, and strengthen the link between DNA damage and aging. PMID:25299392

  1. Cell-autonomous progeroid changes in conditional mouse models for repair endonuclease XPG deficiency

    SciTech Connect

    Barnhoorn, Sander; Uittenboogaard, Lieneke M.; Jaarsma, Dick; Vermeij, Wilbert P.; Tresini, Maria; Weymaere, Michael; Menoni, Hervé; Brandt, Renata M. C.; de Waard, Monique C.; Botter, Sander M.; Sarker, Altaf H.; Jaspers, Nicolaas G. J.; van der Horst, Gijsbertus T. J.; Cooper, Priscilla K.; Hoeijmakers, Jan H. J.; van der Pluijm, Ingrid; Niedernhofer, Laura J.

    2014-10-09

    As part of the Nucleotide Excision Repair (NER) process, the endonuclease XPG is involved in repair of helix-distorting DNA lesions, but the protein has also been implicated in several other DNA repair systems, complicating genotype-phenotype relationship in XPG patients. Defects in XPG can cause either the cancer-prone condition xeroderma pigmentosum (XP) alone, or XP combined with the severe neurodevelopmental disorder Cockayne Syndrome (CS), or the infantile lethal cerebro-oculo-facio-skeletal (COFS) syndrome, characterized by dramatic growth failure, progressive neurodevelopmental abnormalities and greatly reduced life expectancy. Here, we present a novel (conditional) Xpg-/- mouse model which—in a C57BL6/FVB F1 hybrid genetic background—displays many progeroid features, including cessation of growth, loss of subcutaneous fat, kyphosis, osteoporosis, retinal photoreceptor loss, liver aging, extensive neurodegeneration, and a short lifespan of 4–5 months. We show that deletion of XPG specifically in the liver reproduces the progeroid features in the liver, yet abolishes the effect on growth or lifespan. In addition, specific XPG deletion in neurons and glia of the forebrain creates a progressive neurodegenerative phenotype that shows many characteristics of human XPG deficiency. Our findings therefore exclude that both the liver as well as the neurological phenotype are a secondary consequence of derailment in other cell types, organs or tissues (e.g. vascular abnormalities) and support a cell-autonomous origin caused by the DNA repair defect itself. In addition they allow the dissection of the complex aging process in tissue- and cell-type-specific components. Moreover, our data highlight the critical importance of genetic background in mouse aging studies, establish the Xpg-/- mouse as a valid model for the severe form of human XPG patients and segmental accelerated aging, and strengthen the link between DNA damage and aging.

  2. Current State of Animal (Mouse) Modeling in Melanoma Research

    PubMed Central

    Kuzu, Omer F.; Nguyen, Felix D.; Noory, Mohammad A.; Sharma, Arati

    2015-01-01

    Despite the considerable progress in understanding the biology of human cancer and technological advancement in drug discovery, treatment failure remains an inevitable outcome for most cancer patients with advanced diseases, including melanoma. Despite FDA-approved BRAF-targeted therapies for advanced stage melanoma showed a great deal of promise, development of rapid resistance limits the success. Hence, the overall success rate of melanoma therapy still remains to be one of the worst compared to other malignancies. Advancement of next-generation sequencing technology allowed better identification of alterations that trigger melanoma development. As development of successful therapies strongly depends on clinically relevant preclinical models, together with the new findings, more advanced melanoma models have been generated. In this article, besides traditional mouse models of melanoma, we will discuss recent ones, such as patient-derived tumor xenografts, topically inducible BRAF mouse model and RCAS/TVA-based model, and their advantages as well as limitations. Although mouse models of melanoma are often criticized as poor predictors of whether an experimental drug would be an effective treatment, development of new and more relevant models could circumvent this problem in the near future. PMID:26483610

  3. Comprehensive Neurocognitive Endophenotyping Strategies for Mouse Models of Genetic Disorders

    PubMed Central

    Hunsaker, Michael R.

    2012-01-01

    There is a need for refinement of the current behavioral phenotyping methods for mouse models of genetic disorders. The current approach is to perform a behavioral screen using standardized tasks to define a broad phenotype of the model. This phenotype is then compared to what is known concerning the disorder being modeled. The weakness inherent in this approach is twofold: First, the tasks that make up these standard behavioral screens do not model specific behaviors associated with a given genetic mutation but rather phenotypes affected in various genetic disorders; secondly, these behavioral tasks are insufficiently sensitive to identify subtle phenotypes. An alternate phenotyping strategy is to determine the core behavioral phenotypes of the genetic disorder being studied and develop behavioral tasks to evaluate specific hypotheses concerning the behavioral consequences of the genetic mutation. This approach emphasizes direct comparisons between the mouse and human that facilitate the development of neurobehavioral biomarkers or quantitative outcome measures for studies of genetic disorders across species. PMID:22266125

  4. MRI as a tool to study brain structure from mouse models for mental retardation

    NASA Astrophysics Data System (ADS)

    Verhoye, Marleen; Sijbers, Jan; Kooy, R. F.; Reyniers, E.; Fransen, E.; Oostra, B. A.; Willems, Peter; Van der Linden, Anne-Marie

    1998-07-01

    Nowadays, transgenic mice are a common tool to study brain abnormalities in neurological disorders. These studies usually rely on neuropathological examinations, which have a number of drawbacks, including the risk of artefacts introduced by fixation and dehydration procedures. Here we present 3D Fast Spin Echo Magnetic Resonance Imaging (MRI) in combination with 2D and 3D segmentation techniques as a powerful tool to study brain anatomy. We set up MRI of the brain in mouse models for the fragile X syndrome (FMR1 knockout) and Corpus callosum hypoplasia, mental Retardation, Adducted thumbs, Spastic paraplegia and Hydrocephalus (CRASH) syndrome (L1CAM knockout). Our major goal was to determine qualitative and quantitative differences in specific brain structures. MRI of the brain of fragile X and CRASH patients has revealed alterations in the size of specific brain structures, including the cerebellar vermis and the ventricular system. In the present MRI study of the brain from fragile X knockout mice, we have measured the size of the brain, cerebellum and 4th ventricle, which were reported as abnormal in human fragile X patients, but found no evidence for altered brain regions in the mouse model. In CRASH syndrome, the most specific brain abnormalities are vermis hypoplasia and abnormalities of the ventricular system with some degree of hydrocephalus. With the MRI study of L1CAM knockout mice we found vermis hypoplasia, abnormalities of the ventricular system including dilatation of the lateral and the 4th ventricles. These subtle abnormalities were not detected upon standard neuropathological examination. Here we proved that this sensitive MRI technique allows to measure small differences which can not always be detected by means of pathology.

  5. Establishing a murine model of the Hematopoietic Syndrome of the Acute Radiation Syndrome

    PubMed Central

    Plett, P. Artur; Sampson, Carol H.; Chua, Hui Lin; Joshi, Mandar; Booth, Catherine; Gough, Alec; Johnson, Cynthia S.; Katz, Barry P.; Farese, Ann M.; Parker, Jeffrey; MacVittie, Thomas J.; Orschell, Christie M.

    2012-01-01

    We have developed a murine model of the Hematopoietic Syndrome of the Acute Radiation Syndrome (H-ARS) for efficacy testing of medical countermeasures (MCM) against radiation according to the FDA Animal Rule. Ten to 12 week old male and female C57BL/6 mice were exposed to the LD50/30-LD70/30 dose of total body irradiation (TBI, 137Cs, 0.62-0.67 Gy min-1) in the morning hours when mice were determined to be most radiosensitive, and assessed for 30 day survival and mean survival time (MST). Antibiotics were delivered in the drinking water on days 4-30 post-TBI at a concentration based on the amount of water that lethally-irradiated mice were found to consume. The fluoroquinolones, ciprofloxacin and levofloxacin, and the tetracycline doxycycline and aminoglycoside neomycin, all significantly increased MST of decedent mice, while ciprofloxacin (p=0.061) and doxycycline + neomycin (p=0.005) showed at least some efficacy to increase 30 day survival. Blood sampling (30uL/mouse every 5th day) was found to negatively impact 30 day survival. Histopathology of tissues harvested from non-moribund mice showed expected effects of lethal irradiation, while moribund mice were largely septicemic with a preponderance of enteric organisms. Kinetics of loss and recovery of peripheral blood cells in untreated mice and those treated with two MCM, granulocyte-colony stimulating factor and Amifostine, further characterized and validated our model for use in screening studies and pivotal efficacy studies of candidate MCM for licensure to treat irradiated individuals suffering from H-ARS. PMID:22929467

  6. Loganin inhibits the inflammatory response in mouse 3T3L1 adipocytes and mouse model.

    PubMed

    Li, Yang; Li, Zheng; Shi, Lei; Zhao, Chenxu; Shen, Bingyu; Tian, Ye; Feng, Haihua

    2016-07-01

    Atherosclerosis is a chronic inflammatory disease of the vascular walls. ApoCIII is an independent factor which promotes atherosclerotic processes. This study aimed to investigate whether Loganin administration inhibits the inflammatory response in vitro and in vivo. In the apoCIII-induced mouse adipocytes, the levels of cytokines, including TNF-α, MCP-1 and IL-6 were determined by enzyme-linked immunosorbent assay and their gene expressions were measured through RT-PCR. The phosphorylation of nuclear factor-κB (NF-κB) proteins was analyzed by Western blotting. Our results showed that Loganin markedly decreased TNF-α, MCP-1 and IL-6 concentrations as well as their gene expressions. Western blotting analysis indicated that Loganin suppressed the activation of NF-κB signaling. In the Tyloxapol-treated mouse model, Loganin reduced the contents of TC and TG in mouse serum. The results of Oil Red-O Staining showed that Loganin reduced the production of lipid droplets. So it is suggested that Loganin might be a potential therapeutic agent for preventing the inflammation stress in vitro and in vivo. PMID:27155393

  7. Model Organisms and Traditional Chinese Medicine Syndrome Models

    PubMed Central

    Xu, Jin-Wen

    2013-01-01

    Traditional Chinese medicine (TCM) is an ancient medical system with a unique cultural background. Nowadays, more and more Western countries due to its therapeutic efficacy are accepting it. However, safety and clear pharmacological action mechanisms of TCM are still uncertain. Due to the potential application of TCM in healthcare, it is necessary to construct a scientific evaluation system with TCM characteristics and benchmark the difference from the standard of Western medicine. Model organisms have played an important role in the understanding of basic biological processes. It is easier to be studied in certain research aspects and to obtain the information of other species. Despite the controversy over suitable syndrome animal model under TCM theoretical guide, it is unquestionable that many model organisms should be used in the studies of TCM modernization, which will bring modern scientific standards into mysterious ancient Chinese medicine. In this review, we aim to summarize the utilization of model organisms in the construction of TCM syndrome model and highlight the relevance of modern medicine with TCM syndrome animal model. It will serve as the foundation for further research of model organisms and for its application in TCM syndrome model. PMID:24381636

  8. Genetic modeling of ovarian phenotypes in mice for the study of human polycystic ovary syndrome.

    PubMed

    Feng, Yi; Li, Xin; Shao, Ruijin

    2013-01-01

    Polycystic ovary syndrome (PCOS) presents with a range of clinical complications including hyperandrogenism, polycystic ovaries, chronic oligo/anovulation, infertility, and metabolic alterations related to insulin resistance. Because the mechanism by which this disorder develops is poorly understood, information from experimental models of human disease phenotypes may help to define the mechanisms for the initiation and development of PCOS-related pathological events. The establishment of animal models compatible with human PCOS is challenging, and applying the lessons learned from these models to human PCOS is often complicated. In this mini-review we provide examples of currently available genetic mouse models, their ovarian phenotypes, and their possible relationship to different aspects of human PCOS. Because of the practical and ethical limitations of studying PCOS-related events in humans, our understanding of the mechanisms that contribute to the etiology of human PCOS may be enhanced through further study of these transgenic and knockout mouse models. PMID:23390562

  9. [Evaluation of imaging biomarker by transgenic mouse models].

    PubMed

    Maeda, Jun; Higuchi, Makoto; Suhara, Tetsuya

    2009-04-01

    The invention of trangenic and gene knockout mice contributes to the understanding of various brain functions. With the previous-generation positron emission tomography (PET) camera it was impossible to visualize the mouse brain functions, while the newly developed small-animal PET camera with higher resolution is enough to visualize the mouse brain functions. In the present study, we investigated the visualization of functional brain images for a few transgenic mouse models using the small-animal PET. In neurodegenerative illnesses such as Alzheimer disease (AD), the relationship between etiopathology and main symptoms has been elucidated relatively well; therefore several transgenic mice have been already developed. We succeeded in visualizing amyloid images in human mutant amyloid precursor protein (APP) transgenic mice brains. This result suggested that small-animal PET enabled the quantitative analysis of pathologies in the Tg mouse brain. Psychiatric disorders are presumed to have underlying multiple neural dysfunctions. Despite some efficient medicinal therapies having been already established, the etiopathology of mental illness and its biological markers have not been clarified. Thus, we investigated in type II Ca-calmodulin-dependent protein kinase alpha (CaMKII alpha) heterozygous knockout (hKO) mouse, a major protein kinase in the brain. The CaMKII alpha hKO mice have several abnormal behavioral phenotypes, such as hyper aggression and lack of anxiogenic responses; therefore CaMKII alpha might involve in the pathogenesis of mood disorder and affect personal characterizations. Furthermore, serotonin (5-HT) 1A receptor density in the CaMKII alpha hKO mouse brain changed among various brain regions compared to wild mice. These mechanistic insights, PET assays of Tg mice that we have established here, provide an efficient methodology for preclinical evaluation of emerging diagnostic and therapeutic agents for neurodegenerative and psychiatric illnesses

  10. Characterization of a Mouse Model of Hyperglycemia and Retinal Neovascularization

    PubMed Central

    Rakoczy, Elizabeth P.; Rahman, Ireni S. Ali; Binz, Nicolette; Li, Cai-Rui; Vagaja, Nermina N.; de Pinho, Marisa; Lai, Chooi-May

    2010-01-01

    One of the limitations of research into diabetic retinopathy is the lack of suitable animal models. To study how the two important factors—hyperglycemia and vascular endothelial growth factor—interact in diabetic retinopathy, the Akimba mouse (Ins2AkitaVEGF+/−) was generated by crossing the Akita mouse (Ins2Akita) with the Kimba mouse (VEGF+/+). C57Bl/6 and the parental and Akimba mouse lines were characterized by biometric measurements, histology, immunohistochemistry, and Spectralis Heidelberg retinal angiography and optical coherence tomography. The Akimba line not only retained the characteristics of the parental strains, such as developing hyperglycemia and retinal neovascularization, but developed higher blood glucose levels at a younger age and had worse kidney-body weight ratios than the Akita line. With aging, the Akimba line demonstrated enhanced photoreceptor cell loss, thinning of the retina, and more severe retinal vascular pathology, including more severe capillary nonperfusion, vessel constriction, beading, neovascularization, fibroses, and edema, compared with the Kimba line. The vascular changes were associated with major histocompatibility complex class II+ cellular staining throughout the retina. Together, these observations suggest that hyperglycemia resulted in higher prevalences of edema and exacerbated the vascular endothelial growth factor-driven neovascular and retinal changes in the Akimba line. Thus, the Akimba line could become a useful model for studying the interplay between hyperglycemia and vascular endothelial growth factor and for testing treatment strategies for potentially blinding complications, such as edema. PMID:20829433

  11. Mouse models of liver cancer: Progress and recommendations.

    PubMed

    He, Li; Tian, De-An; Li, Pei-Yuan; He, Xing-Xing

    2015-09-15

    To clarify the pathogenesis of hepatocellular carcinoma (HCC) and investigate the effects of potential therapies, a number of mouse models have been developed. Subcutaneous xenograft models are widely used in the past decades. Yet, with the advent of in vivo imaging technology, investigators are more and more concerned with the orthotopic models nowadays. Genetically engineered mouse models (GEM) have greatly facilitated studies of gene function in HCC development. Recently, GEM of miR-122 and miR-221 provided new approaches for better understanding of the in vivo functions of microRNA in hepatocarcinogenesis. Chemically induced liver tumors in animals share many of the morphological, histogenic, and biochemical features of human HCC. Yet, the complicated and obscure genomic alternation restricts their applications. In this review, we highlight both the frequently used mouse models and some emerging ones with emphasis on their merits or defects, and give advises for investigators to chose a "best-fit" animal model in HCC research. PMID:26259234

  12. A candidate mouse model for Hartnup disorder deficient in neutral amino acid transport.

    PubMed

    Symula, D J; Shedlovsky, A; Guillery, E N; Dove, W F

    1997-02-01

    The mutant mouse strain HPH2 (hyperphenylalaninemia) was isolated after N-ethyl-N-nitrosourea (ENU) mutagenesis on the basis of delayed plasma clearance of an injected load of phenylalanine. Animals homozygous for the recessive hph2 mutation excrete elevated concentrations of many of the neutral amino acids in the urine, while plasma concentrations of these amino acids are normal. In contrast, mutant homozygotes excrete normal levels of glucose and phosphorus. These data suggest an amino acid transport defect in the mutant, confirmed in a small reduction in normalized values of 14C-labeled glutamine uptake by kidney cortex brush border membrane vesicles (BBMV). The hyperaminoaciduria pattern is very similar to that of Hartnup Disorder cases also show niacin deficiency symptoms, of Hartnup Disorder cases also show niacin deficiency symptoms, which are thought to be multifactorially determined. Similarly, the HPH2 mouse exhibits a niacin-reversible syndrome that is modified by diet and by genetic background. Thus, HPH2 provides a candidate mouse model for the study of Hartnup Disorder, an amino acid transport deficiency and a multifactorial disease in the human. PMID:9060408

  13. MPTP Mouse Models of Parkinson’s Disease: An Update

    PubMed Central

    Meredith, Gloria E.; Rademacher, David J.

    2012-01-01

    Among the most widely used models of Parkinson’s disease (PD) are those that employ toxins, especially 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). Depending on the protocol used, MPTP yields large variations in nigral cell loss, striatal dopamine loss and behavioral deficits. Motor deficits do not fully replicate those seen in PD. Nonetheless, MPTP mouse models mimic many aspects of the disease and are therefore important tools for understanding PD. In this review, we will discuss the ability of MPTP mouse models to replicate the pathophysiology of PD, the mechanisms of MPTP-induced neurotoxicity, strain differences in susceptibility to MPTP, and the models’ roles in testing therapeutic approaches. PMID:23275799

  14. Osthole suppresses seizures in the mouse maximal electroshock seizure model.

    PubMed

    Luszczki, Jarogniew J; Andres-Mach, Marta; Cisowski, Wojciech; Mazol, Irena; Glowniak, Kazimierz; Czuczwar, Stanislaw J

    2009-04-01

    The aim of this study was to determine the anticonvulsant effects of osthole {[7-methoxy-8-(3-methyl-2-butenyl)-2H-1-benzopyran-2-one]--a natural coumarin derivative} in the mouse maximal electroshock-induced seizure model. The antiseizure effects of osthole were determined at 15, 30, 60, and 120 min after its systemic (i.p.) administration. Time course of anticonvulsant action of osthole revealed that the natural coumarin derivative produced a clear-cut antielectroshock activity in mice and the experimentally-derived ED(50) values for osthole ranged from 259 to 631 mg/kg. In conclusion, osthole suppresses seizure activity in the mouse maximal electroshock-induced seizure model. It may become a novel treatment option following further investigation in other animal models of epilepsy and preclinical studies. PMID:19236860

  15. Oxidative Stress in Genetic Mouse Models of Parkinson's Disease

    PubMed Central

    Varçin, Mustafa; Bentea, Eduard; Michotte, Yvette; Sarre, Sophie

    2012-01-01

    There is extensive evidence in Parkinson's disease of a link between oxidative stress and some of the monogenically inherited Parkinson's disease-associated genes. This paper focuses on the importance of this link and potential impact on neuronal function. Basic mechanisms of oxidative stress, the cellular antioxidant machinery, and the main sources of cellular oxidative stress are reviewed. Moreover, attention is given to the complex interaction between oxidative stress and other prominent pathogenic pathways in Parkinson's disease, such as mitochondrial dysfunction and neuroinflammation. Furthermore, an overview of the existing genetic mouse models of Parkinson's disease is given and the evidence of oxidative stress in these models highlighted. Taken into consideration the importance of ageing and environmental factors as a risk for developing Parkinson's disease, gene-environment interactions in genetically engineered mouse models of Parkinson's disease are also discussed, highlighting the role of oxidative damage in the interplay between genetic makeup, environmental stress, and ageing in Parkinson's disease. PMID:22829959

  16. Mouse models of neural tube defects: investigating preventive mechanisms.

    PubMed

    Greene, Nicholas D E; Copp, Andrew J

    2005-05-15

    Neural tube defects (NTD), including anencephaly and spina bifida, are a group of severe congenital abnormalities in which the future brain and/or spinal cord fail to close. In mice, NTD may result from genetic mutations or knockouts, or from exposure to teratogenic agents, several of which are known risk factors in humans. Among the many mouse NTD models that have been identified to date, a number have been tested for possible primary prevention of NTD by exogenous agents, such as folic acid. In genetic NTD models such as Cart1, splotch, Cited2, and crooked tail, and NTD induced by teratogens including valproic acid and fumonisins, the incidence of defects is reduced by maternal folic acid supplementation. These folate-responsive models provide an opportunity to investigate the possible mechanisms underlying prevention of NTD by folic acid in humans. In another group of mouse models, that includes curly tail, axial defects, and the Ephrin-A5 knockout, NTD are not preventable by folic acid, reflecting the situation in humans in which a subset of NTD appear resistant to folic acid therapy. In this group of mutants alternative preventive agents, including inositol and methionine, have been shown to be effective. Overall, the data from mouse models suggests that a broad-based in utero therapy may offer scope for prevention of a greater proportion of NTD than is currently possible. PMID:15800852

  17. The Mouse Median Nerve Experimental Model in Regenerative Research

    PubMed Central

    Buskbjerg Jager, Sara

    2014-01-01

    Sciatic nerve crush injury in rat animal model is one of the most common experimental models used in regenerative research. However, the availability of transgenic mouse for nerve regeneration studies is constantly increasing and, therefore, the shift from rat model to mouse model is, in some cases, necessary. Moreover, since most of the human nerve lesions occur in the upper limb, it is also advantageous to shift from sciatic nerve to median nerve. In this study we described an experimental model which involves lesions of the median nerve in the mouse. Data showed that the finger flexor muscle contraction strength, assessed to evaluate the motor function recovery, and reached values not different from the control already 20 days after injury. The degree of nerve regeneration evaluated with stereological methods in light microscopy showed that, 25 days after injury, the number of regenerated myelinated fibers was comparable to the control, but they were smaller with a thinner myelin thickness. Stereological analysis made in electron microscopy confirmed these results, although the total number of fibers quantified was significantly higher compared to light microscopy analysis, due to the very small size of some fibers that can be detected only in electron microscopy. PMID:25180190

  18. Neuroanatomical changes in a mouse model of early life neglect.

    PubMed

    Duque, Alvaro; Coman, Daniel; Carlyle, Becky C; Bordner, Kelly A; George, Elizabeth D; Papademetris, Xenophon; Hyder, Fahmeed; Simen, Arthur A

    2012-04-01

    Using a novel mouse model of early life neglect and abuse (ENA) based on maternal separation with early weaning, George et al. (BMC Neurosci 11:123, 2010) demonstrated behavioral abnormalities in adult mice, and Bordner et al. (Front Psychiatry 2(18):1-18, 2011) described concomitant changes in mRNA and protein expression. Using the same model, here we report neuroanatomical changes that include smaller brain size and abnormal inter-hemispheric asymmetry, decreases in cortical thickness, abnormalities in subcortical structures, and white matter disorganization and atrophy most severely affecting the left hemisphere. Because of the similarities between the neuroanatomical changes observed in our mouse model and those described in human survivors of ENA, this novel animal model is potentially useful for studies of human ENA too costly or cumbersome to be carried out in primates. Moreover, our current knowledge of the mouse genome makes this model particularly suited for targeted anatomical, molecular, and pharmacological experimentation not yet possible in other species. PMID:21984312

  19. Neuroanatomical changes in a mouse model of early life neglect

    PubMed Central

    Duque, Alvaro; Coman, Daniel; Carlyle, Becky C.; Bordner, Kelly A.; George, Elizabeth D.; Papademetris, Xenophon; Hyder, Fahmeed

    2013-01-01

    Using a novel mouse model of early life neglect and abuse (ENA) based on maternal separation with early weaning, George et al. (BMC Neurosci 11:123, 2010) demonstrated behavioral abnormalities in adult mice, and Bordner et al. (Front Psychiatry 2(18):1–18, 2011) described concomitant changes in mRNA and protein expression. Using the same model, here we report neuroanatomical changes that include smaller brain size and abnormal inter-hemispheric asymmetry, decreases in cortical thickness, abnormalities in subcortical structures, and white matter disorganization and atrophy most severely affecting the left hemisphere. Because of the similarities between the neuroanatomical changes observed in our mouse model and those described in human survivors of ENA, this novel animal model is potentially useful for studies of human ENA too costly or cumbersome to be carried out in primates. Moreover, our current knowledge of the mouse genome makes this model particularly suited for targeted anatomical, molecular, and pharmacological experimentation not yet possible in other species. PMID:21984312

  20. Mouse Models of Asthma.

    PubMed

    Debeuf, Nincy; Haspeslagh, Eline; van Helden, Mary; Hammad, Hamida; Lambrecht, Bart N

    2016-01-01

    Allergic asthma is a chronic inflammatory disease of the conducting airways characterized by the presence of allergen-specific IgE, Th2 cytokine production, eosinophilic airway inflammation, bronchial hyperreactivity, mucus overproduction, and structural changes in the airways. Investigators have tried to mimic these features of human allergic asthma in murine models. Whereas the surrogate allergen ovalbumin has been extremely valuable for unravelling underlying mechanisms of the disease, murine asthma models depend nowadays on naturally occurring allergens, such as house dust mite (HDM), cockroach, and Alternaria alternata. Here we describe a physiologically relevant model of acute allergic asthma based on sensitization and challenge with HDM extracts, and compare it with the ovalbumin/alum-induced asthma model. Moreover, we propose a detailed readout of the asthma phenotype, determining the degree of eosinophilia in bronchoalveolar lavage fluids by flow cytometry, visualizing goblet cell metaplasia, and measuring Th cytokine production by lung-draining mediastinal lymph node cells restimulated with HDM. © 2016 by John Wiley & Sons, Inc. PMID:27248433

  1. Genetically engineered mouse models to evaluate the role of Wnt secretion in bone development and homeostasis.

    PubMed

    Williams, Bart O

    2016-03-01

    Alterations in components of the Wnt signaling pathway are associated with altered bone development and homeostasis in several human diseases. We created genetically engineered mouse models (GEMMs) that mimic the cellular defect associated with the Porcupine mutations in patients with Goltz Syndrome/Focal Dermal Hypoplasia. These GEMMs were established by utilizing mice containing a conditionally inactivatable allele of Wntless/GPR177 (a gene encoding a protein required for the transport of Porcupine-modified ligand to the plasma membrane for secretion). We crossed this strain to another which drives cre-mediated gene deletion in mature osteoblasts (Osteocalcin-cre) resulted in mice lacking the ability to secrete Wnt ligands in this cell type. These mice displayed severely reduced bone mass and provide a model to understand the effects of disrupting the ability to secrete Wnt ligands on the skeletal system. © 2016 Wiley Periodicals, Inc. PMID:26818176

  2. An Orthotopic Mouse Model of Spontaneous Breast Cancer Metastasis.

    PubMed

    Paschall, Amy V; Liu, Kebin

    2016-01-01

    Metastasis is the primary cause of mortality of breast cancer patients. The mechanism underlying cancer cell metastasis, including breast cancer metastasis, is largely unknown and is a focus in cancer research. Various breast cancer spontaneous metastasis mouse models have been established. Here, we report a simplified procedure to establish orthotopic transplanted breast cancer primary tumor and resultant spontaneous metastasis that mimic human breast cancer metastasis. Combined with the bioluminescence live tumor imaging, this mouse model allows tumor growth and progression kinetics to be monitored and quantified. In this model, a low dose (1 x 10(4) cells) of 4T1-Luc breast cancer cells was injected into BALB/c mouse mammary fat pad using a tuberculin syringe. Mice were injected with luciferin and imaged at various time points using a bioluminescent imaging system. When the primary tumors grew to the size limit as in the IACUC-approved protocol (approximately 30 days), mice were anesthetized under constant flow of 2% isoflurane and oxygen. The tumor area was sterilized with 70% ethanol. The mouse skin around the tumor was excised to expose the tumor which was removed with a pair of sterile scissors. Removal of the primary tumor extends the survival of the 4T-1 tumor-bearing mice for one month. The mice were then repeatedly imaged for metastatic tumor spreading to distant organs. Therapeutic agents can be administered to suppress tumor metastasis at this point. This model is simple and yet sensitive in quantifying breast cancer cell growth in the primary site and progression kinetics to distant organs, and thus is an excellent model for studying breast cancer growth and progression, and for testing anti-metastasis therapeutic and immunotherapeutic agents in vivo. PMID:27584043

  3. What can transgenic and gene-targeted mouse models teach us about salivary gland physiology?

    PubMed

    Melvin, J E; Nguyen, H V; Evans, R L; Shull, G E

    2000-12-01

    Thousands of genetically modified mice have been developed since the first reports of stable expression of recombinant DNA in this species nearly 20 years ago. This mammalian model system has revolutionized the study of whole-animal, organ, and cell physiology. Transgenic and gene-targeted mice have been widely used to characterize salivary-gland-specific expression and to identify genes associated with tumorigenesis. Moreover, several of these mouse lines have proved to be useful models of salivary gland disease related to impaired immunology, i.e., Sjögren's syndrome, and disease states associated with pathogens. Despite the availability of genetically modified mice, few investigators have taken advantage of this resource to better their understanding of salivary gland function as it relates to the production of saliva. In this article, we describe the methods used to generate transgenic and gene-targeted mice and provide an overview of the advantages of and potential difficulties with these models. Finally, using these mouse models, we discuss the advances made in our understanding of the salivary gland secretion process. PMID:11842924

  4. Mouse Transient Global Ischemia Two-Vessel Occlusion Model

    PubMed Central

    Pontarelli, Fabrizio; Ofengeim, Dimitry; Zukin, R. Suzanne; Jonas, Elizabeth A.

    2016-01-01

    Transient global ischemia in rodents induces delayed death of hippocampal CA1 neurons, as well as in some hilar neurons of the dentate gyrus, medium aspiny neurons of the striatum, pyramidal neurons in neocortical layers II, V and VI, and Purkinje neurons of the cerebellum. In contrast to focal ischemia that mimics regional stroke in humans, this model of global ischemia mimics the brain injury that occurs after human cardiac arrest. Early events include caspase activation, cleavage of anti-death Bcl-2 family proteins and large mitochondrial channel activity. Genetically engineered mice provide opportunities for study such as the knock-in mouse expressing a caspase-resistant form of Bcl-xL found to exhibit markedly reduced mitochondrial channel activity and reduced vulnerability to ischemia-induced neuronal death1. It is therefore relevant to adapt and develop a simple protocol for producing transient global ischemia in mouse2. The two-vessel occlusion model has been specifically developed to provide optimal outcomes in mouse and offers several advantages over the four-vessel occlusion model traditionally used in rat including the relative ease of the procedure as well as only a single day of surgery. However it should be noted that this procedure has a higher morbidity rate compared to other ischemia models as well as a higher degree of variability. These two disadvantages necessitate the use of a larger cohort of animals, which for many healthy breeding transgenic animals is a non-deterring factor.

  5. Mouse models of papillary thyroid carcinoma - short review.

    PubMed

    Rusinek, Dagmara; Krajewska, Jolanta; Jarząb, Michał

    2016-01-01

    Thyroid carcinoma (TC) is the most common endocrine malignancy, and its frequency is still rising. Papillary thyroid carcinoma (PTC) accounts for 80% of all TCs and usually is related to a very good prognosis. However, the standard therapeutic approaches are not always sufficient and disease progression is sometimes observed. These data highlight the limitation of our understanding of molecular mechanisms underlying tumorigenesis and how they vary between individual patients. Over the last 19 years mouse models of thyroid cancers have been developed in order to give answers to questions about their genetic background, relations of key molecular events with pathways fundamental for cancer, and many others. Among these models genetically engineered mice were of utmost importance regarding the input of knowledge about human tumorigenesis. In the present review the most significant mouse models of PTC are described with particular emphasis on BRAFV600E-induced ones, for the sake of its frequency in PTC, relation to factors of poor prognosis, and the fact that, since its identification, it became an attractive target in novel therapies. For the presented mouse models phenotype consequences of particular genetic alterations are described as well as the limitations of the used methods. (Endokrynol Pol 2016; 67 (2): 212-223). PMID:27082155

  6. Development of a Representative Mouse Model with Nonalcoholic Steatohepatitis.

    PubMed

    Verbeek, Jef; Jacobs, Ans; Spincemaille, Pieter; Cassiman, David

    2016-01-01

    Non-alcoholic fatty liver disease (NAFLD) is the most prevalent liver disease in the Western world. It represents a disease spectrum ranging from isolated steatosis to non-alcoholic steatohepatitis (NASH). In particular, NASH can evolve to fibrosis, cirrhosis, hepatocellular carcinoma, and liver failure. The development of novel treatment strategies is hampered by the lack of representative NASH mouse models. Here, we describe a NASH mouse model, which is based on feeding non-genetically manipulated C57BL6/J mice a 'Western style' high-fat/high-sucrose diet (HF-HSD). HF-HSD leads to early obesity, insulin resistance, and hypercholesterolemia. After 12 weeks of HF-HSD, all mice exhibit the complete spectrum of features of NASH, including steatosis, hepatocyte ballooning, and lobular inflammation, together with fibrosis in the majority of mice. Hence, this model closely mimics the human disease. Implementation of this mouse model will lead to a standardized setup for the evaluation of (i) underlying mechanisms that contribute to the progression of NAFLD to NASH, and (ii) therapeutic interventions for NASH. © 2016 by John Wiley & Sons, Inc. PMID:27248435

  7. Nonspecific airway reactivity in a mouse model of asthma

    SciTech Connect

    Collie, D.D.; Wilder, J.A.; Bice, D.E.

    1995-12-01

    Animal models are indispensable for studies requiring an intact immune system, especially for studying the pathogenic mechanisms in atopic diseases, regulation of IgE production, and related biologic effects. Mice are particularly suitable and have been used extensively for such studies because their immune system is well characterized. Further, large numbers of mutants or inbred strains of mice are available that express deficiencies of individual immunologic processes, inflammatory cells, or mediator systems. By comparing reactions in such mice with appropriate control animals, the unique roles of individual cells or mediators may be characterized more precisely in the pathogenesis of atopic respiratory diseases including asthma. However, given that asthma in humans is characterized by the presence of airway hyperresponsiveness to specific and nonspecific stimuli, it is important that animal models of this disease exhibit similar physiologic abnormalities. In the past, the size of the mouse has limited its versatility in this regard. However, recent studies indicate the feasibility of measuring pulmonary responses in living mice, thus facilitating the physiologic evaluation of putative mouse models of human asthma that have been well charcterized at the immunologic and patholigic level. Future work will provide details of the morphometry of the methacholine-induced bronchoconstriction and will further seek to determine the relationship between cigarette smoke exposure and the development of NS-AHR in the transgenic mouse model.

  8. A simple generative model of the mouse mesoscale connectome

    PubMed Central

    Henriksen, Sid; Pang, Rich; Wronkiewicz, Mark

    2016-01-01

    Recent technological advances now allow for the collection of vast data sets detailing the intricate neural connectivity patterns of various organisms. Oh et al. (2014) recently published the most complete description of the mouse mesoscale connectome acquired to date. Here we give an in-depth characterization of this connectome and propose a generative network model which utilizes two elemental organizational principles: proximal attachment ‒ outgoing connections are more likely to attach to nearby nodes than to distant ones, and source growth ‒ nodes with many outgoing connections are likely to form new outgoing connections. We show that this model captures essential principles governing network organization at the mesoscale level in the mouse brain and is consistent with biologically plausible developmental processes. DOI: http://dx.doi.org/10.7554/eLife.12366.001 PMID:26978793

  9. Mouse models for the study of colon carcinogenesis

    PubMed Central

    Rosenberg, Daniel W.; Giardina, Charles; Tanaka, Takuji

    2009-01-01

    The study of experimental colon carcinogenesis in rodents has a long history, dating back almost 80 years. There are many advantages to studying the pathogenesis of carcinogen-induced colon cancer in mouse models, including rapid and reproducible tumor induction and the recapitulation of the adenoma–carcinoma sequence that occurs in humans. The availability of recombinant inbred mouse panels and the existence of transgenic, knock-out and knock-in genetic models further increase the value of these studies. In this review, we discuss the general mechanisms of tumor initiation elicited by commonly used chemical carcinogens and how genetic background influences the extent of disease. We will also describe the general features of lesions formed in response to carcinogen treatment, including the underlying molecular aberrations and how these changes may relate to the pathogenesis of human colorectal cancer. PMID:19037092

  10. Modeling Rett Syndrome Using Human Induced Pluripotent Stem Cells.

    PubMed

    Andoh-Noda, Tomoko; Inouye, Michiko O; Miyake, Kunio; Kubota, Takeo; Okano, Hideyuki; Akamatsu, Wado

    2016-01-01

    Rett syndrome (RTT) is one of a group of neurodevelopmental disorders typically characterized by deficits in the X-linked gene MECP2 (methyl-CpG binding protein 2). The MECP2 gene encodes a multifunctional protein involved in transcriptional repression, transcriptional activation, chromatin remodeling, and RNA splicing. Genetic deletion of Mecp2 in mice revealed neuronal disabilities including RTT-like phenotypes and provided an excellent platform for understanding the pathogenesis of RTT. So far, there are no effective pharmacological treatments for RTT because the role of MECP2 in RTT is incompletely understood. Recently, human induced pluripotent stem cell (hiPSC) technologies have improved our knowledge of neurological and neurodevelopmental diseases including RTT because neurons derived from RTT-hiPSCs can be used for disease modeling to understand RTT phenotypes and to perform high throughput pharmaceutical drug screening. In this review, we provide an overview of RTT, including MeCP2 function and mouse models of RTT. In addition, we introduce recent advances in disease modeling of RTT using hiPSC-derived neural cells. PMID:27071793

  11. Real-Time Bioluminescence Imaging of Nitroreductase in Mouse Model.

    PubMed

    Feng, Ping; Zhang, Huateng; Deng, Quankun; Liu, Wei; Yang, Linghui; Li, Guobo; Chen, Guo; Du, Lupei; Ke, Bowen; Li, Minyong

    2016-06-01

    Nitroreductase (NTR) is an endogenous reductase overexpressed in hypoxic tumors; however, its precise detection in living cells and animals remains a considerable challenge. Herein, we developed three reaction-based probes and a related bioluminescence assay for the real-time NTR detection. The high sensitivity and selectivity of probe 3, combined with its remarkable potential of bioluminescence imaging, affords a valuable approach for in vivo imaging of NTR in a tumor model mouse. PMID:27197544

  12. Phelan McDermid Syndrome: From Genetic Discoveries to Animal Models and Treatment.

    PubMed

    Harony-Nicolas, Hala; De Rubeis, Silvia; Kolevzon, Alexander; Buxbaum, Joseph D

    2015-12-01

    Phelan-McDermid syndrome or 22q13.3 deletion syndrome is a rare neurodevelopmental disorder characterized by generalized developmental delay, intellectual disability, absent or delayed speech, seizures, autism spectrum disorder, neonatal hypotonia, physical dysmorphic features, and recurrent medical comorbidities. Individuals with Phelan-McDermid syndrome have terminal deletions of the chromosomal region 22q13.3 encompassing SHANK3, a gene encoding a structural component of excitatory synapses indispensable for proper synaptogenesis and neuronal physiology, or point mutations within the gene. Here, we review the clinical aspects of the syndrome and the genetic findings shedding light onto the underlying etiology. We also provide an overview on the evidence from genetic studies and mouse models that supports SHANK3 haploinsufficiency as a major contributor of the neurobehavioral manifestations of Phelan-McDermid syndrome. Finally, we discuss how all these discoveries are uncovering the pathophysiology of Phelan-McDermid syndrome and are being translated into clinical trials for novel therapeutics ameliorating the core symptoms of the disorder. PMID:26350728

  13. Curcumin shows excellent therapeutic effect on psoriasis in mouse model.

    PubMed

    Kang, Di; Li, Bowen; Luo, Lei; Jiang, Wenbing; Lu, Qiumin; Rong, Mingqing; Lai, Ren

    2016-04-01

    Curcumin is an active herbal ingredient possessing surprisingly wide range of beneficial properties, including anti-inflammatory, antioxidant, chemopreventive and chemotherapeutic activity. Recently, it has been reported to exhibit inhibitory activity on potassium channel subtype Kv1.3. As Kv1.3 channels are mainly expressed in T cells and play a key role in psoriasis, the effects of curcumin were investigated on inflammatory factors secretion in T cells and psoriasis developed in keratin (K) 14-vascular endothelial growth factor (VEGF) transgenic mouse model. Results showed that, 10 μM of curcumin significantly inhibited secretion of inflammatory factors including interleukin (IL)-17,IL-22, IFN-γ, IL-2, IL-8 and TNF-α in T cells by 30-60% in vitro. Notably, more than 50% of T cells proliferation was inhibited by application of 100 μM curcumin. Compared with severe psoriatic symptoms observed in the negative control mice, all psoriasis indexes including ear redness, weight, thickness and lymph node weight were significantly improved by oral application of curcumin in treatment mouse group. Histological examination indicated that curcumin had anti-inflammatory function in the experimental animals. More than 50% level of inflammatory factors including TNF-α, IFN-γ, IL-2, IL-12, IL-22 and IL-23 in mouse serum was decreased by curcumin treatment as well as cyclosporine. Compared with renal fibrosis observed in the mouse group treated by cyclosporine, no obvious side effect in mouse kidney was found after treated by curcumin. Taken together, curcumin, with high efficacy and safety, has a great potential to treat psoriasis. PMID:26826458

  14. A Mathematical Model of the Mouse Ventricular Myocyte Contraction

    PubMed Central

    Mullins, Paula D.; Bondarenko, Vladimir E.

    2013-01-01

    Mathematical models of cardiac function at the cellular level include three major components, such as electrical activity, Ca2+ dynamics, and cellular shortening. We developed a model for mouse ventricular myocyte contraction which is based on our previously published comprehensive models of action potential and Ca2+ handling mechanisms. The model was verified with extensive experimental data on mouse myocyte contraction at room temperature. In the model, we implemented variable sarcomere length and indirect modulation of the tropomyosin transition rates by Ca2+ and troponin. The resulting model described well steady-state force-calcium relationships, dependence of the contraction force on the sarcomere length, time course of the contraction force and myocyte shortening, frequency dependence of the contraction force and cellular contraction, and experimentally measured derivatives of the myocyte length variation. We emphasized the importance of the inclusion of variable sarcomere length into a model for ventricular myocyte contraction. Differences in contraction force and cell shortening for epicardial and endocardial ventricular myocytes were investigated. Model applicability for the experimental studies and model limitations were discussed. PMID:23671664

  15. Intraperitoneal inflammation decreases endometriosis in a mouse model

    PubMed Central

    Nowak, N.M.; Fischer, O.M.; Gust, T.C.; Fuhrmann, U.; Habenicht, U.-F.; Schmidt, A.

    2008-01-01

    BACKGROUND The role of the immune system in the pathogenesis of endometriosis remains elusive. It has been shown that patients have an altered peritoneal environment with increased levels of inflammatory cytokines, activated macrophages and reduced clearance of retrogradely transported endometrial fragments. However, it is not known if this unique inflammatory situation is cause or consequence of endometriosis. This study investigates the impact of a pre-existing peritoneal inflammation on endometriosis establishment in a mouse model. METHODS Endometriosis was induced by intraperitoneal injection of enhanced green fluorescent protein (EGFP)-expressing endometrium in mice. In parallel, a peritonitis model was established via intraperitoneal injection of thioglycolate medium (TM). Finally, endometriosis was induced in the inflamed peritoneal cavity and lesion establishment as well as morphological and histological characteristics were analysed. RESULTS Induction of endometriosis in an inflamed peritoneal cavity resulted in fewer lesions and significantly lower sum of lesion surface area per mouse in the TM-treated group. Additionally, a higher amount of non-attached debris could be detected in the peritoneal cavity of TM-treated mice. CONCLUSIONS An intraperitoneal inflammation decreases endometriosis establishment in this mouse model. Thus, a pre-existing peritoneal inflammation might not be a factor favouring the development of endometriosis. PMID:18653673

  16. Primary mouse embryonic fibroblasts: a model of mesenchymal cartilage formation.

    PubMed

    Lengner, Christopher J; Lepper, Christoph; van Wijnen, Andre J; Stein, Janet L; Stein, Gary S; Lian, Jane B

    2004-09-01

    Cartilage formation is an intricate process that requires temporal and spatial organization of regulatory factors in order for a mesenchymal progenitor cell to differentiate through the distinct stages of chondrogenesis. Gene function during this process has best been studied by analysis of in vivo cartilage formation in genetically altered mouse models. Mouse embryonic fibroblasts (MEFs) isolated from such mouse models have been widely used for the study of growth control and DNA damage response. Here, we address the potential of MEFs to undergo chondrogenic differentiation. We demonstrate for the first time that MEFs can enter and complete the program of chondrogenic differentiation ex vivo, from undifferentiated progenitor cells to mature, hypertrophic chondrocytes. We show that chondrogenic differentiation can be induced by cell-cell contact or BMP-2 treatment, while in combination, these conditions synergistically enhance chondrocyte differentiation resulting in the formation of 3-dimensional (3-D) cartilaginous tissue ex vivo. Temporal expression profiles of pro-chondrogenic transcription factors Bapx1 and Sox9 and cartilaginous extracellular matrix (ECM) proteins Collagen Type II and X (Coll II and Coll X) demonstrate that the in vivo progression of chondrocyte maturation is recapitulated in the MEF model system. Our findings establish the MEF as a powerful tool for the generation of cartilaginous tissue ex vivo and for the study of gene function during chondrogenesis. PMID:15254959

  17. Connexin diversity in the heart: insights from transgenic mouse models

    PubMed Central

    Verheule, Sander; Kaese, Sven

    2013-01-01

    Cardiac conduction is mediated by gap junction channels that are formed by connexin (Cx) protein subunits. The connexin family of proteins consists of more than 20 members varying in their biophysical properties and ability to combine with other connexins into heteromeric gap junction channels. The mammalian heart shows regional differences both in connexin expression profile and in degree of electrical coupling. The latter reflects functional requirements for conduction velocity which needs to be low in the sinoatrial and atrioventricular nodes and high in the ventricular conduction system. Over the past 20 years knowledge of the biology of gap junction channels and their role in the genesis of cardiac arrhythmias has increased enormously. This review focuses on the insights gained from transgenic mouse models. The mouse heart expresses Cx30, 30.2, 37, 40, 43, 45, and 46. For these connexins a variety of knock-outs, heart-specific knock-outs, conditional knock-outs, double knock-outs, knock-ins and overexpressors has been studied. We discuss the cardiac phenotype in these models and compare Cx expression between mice and men. Mouse models have enhanced our understanding of (patho)-physiological implications of Cx diversity in the heart. In principle connexin-specific modulation of electrical coupling in the heart represents an interesting treatment strategy for cardiac arrhythmias and conduction disorders. PMID:23818881

  18. Use of mouse models to study plasminogen activator inhibitor-1.

    PubMed

    Declerck, Paul J; Gils, Ann; De Taeye, Bart

    2011-01-01

    Plasminogen activator inhibitor-1 (PAI-1) is the main inhibitor of tissue-type plasminogen activator (t-PA) and urokinase-type plasminogen activator (u-PA) and therefore plays an important role in the plasminogen/plasmin system. PAI-1 is involved in a variety of cardiovascular diseases (mainly through inhibition of t-PA) as well as in cell migration and tumor development (mainly through inhibition of u-PA and interaction with vitronectin). PAI-1 is a unique member of the serpin superfamily, exhibiting particular unique conformational and functional properties. Since its involvement in various biological and pathophysiological processes PAI-1 has been the subject of many in vivo studies in mouse models. We briefly discuss structural and physiological differences between human and mouse PAI-1 that should be taken into account prior to extrapolation of data obtained in mouse models to the human situation. The current review provides an overview of the various models, with a focus on cardiovascular disease and cancer, using wild-type mice or genetically modified mice, either deficient in PAI-1 or overexpressing different variants of PAI-1. PMID:21683250

  19. HIV-1 immunopathogenesis in humanized mouse models

    PubMed Central

    Zhang, Liguo; Su, Lishan

    2012-01-01

    In recent years, the technology of constructing chimeric mice with humanized immune systems has markedly improved. Multiple lineages of human immune cells develop in immunodeficient mice that have been transplanted with human hematopoietic stem cells. More importantly, these mice mount functional humoral and cellular immune responses upon immunization or microbial infection. Human immunodeficiency virus type I (HIV-1) can establish an infection in humanized mice, resulting in CD4+ T-cell depletion and an accompanying nonspecific immune activation, which mimics the immunopathology in HIV-1-infected human patients. This makes humanized mice an optimal model for studying the mechanisms of HIV-1 immunopathogenesis and for developing novel immune-based therapies. PMID:22504952

  20. Behavioral Characterization of Mouse Models of Neuroferritinopathy

    PubMed Central

    Buffoli, Barbara; Rodella, Luigi F.; Cremona, Ottavio; Arosio, Paolo; Cirulli, Francesca

    2015-01-01

    Ferritin is the main intracellular protein of iron storage with a central role in the regulation of iron metabolism and detoxification. Nucleotide insertions in the last exon of the ferritin light chain cause a neurodegenerative disease known as Neuroferritinopathy, characterized by iron deposition in the brain, particularly in the cerebellum, basal ganglia and motor cortex. The disease progresses relentlessly, leading to dystonia, chorea, motor disability and neuropsychiatry features. The characterization of a good animal model is required to compare and contrast specific features with the human disease, in order to gain new insights on the consequences of chronic iron overload on brain function and behavior. To this aim we studied an animal model expressing the pathogenic human FTL mutant 498InsTC under the phosphoglycerate kinase (PGK) promoter. Transgenic (Tg) mice showed strong accumulation of the mutated protein in the brain, which increased with age, and this was accompanied by brain accumulation of ferritin/iron bodies, the main pathologic hallmark of human neuroferritinopathy. Tg-mice were tested throughout development and aging at 2-, 8- and 18-months for motor coordination and balance (Beam Walking and Footprint tests). The Tg-mice showed a significant decrease in motor coordination at 8 and 18 months of age, with a shorter latency to fall and abnormal gait. Furthermore, one group of aged naïve subjects was challenged with two herbicides (Paraquat and Maneb) known to cause oxidative damage. The treatment led to a paradoxical increase in behavioral activation in the transgenic mice, suggestive of altered functioning of the dopaminergic system. Overall, data indicate that mice carrying the pathogenic FTL498InsTC mutation show motor deficits with a developmental profile suggestive of a progressive pathology, as in the human disease. These mice could be a powerful tool to study the neurodegenerative mechanisms leading to the disease and help developing

  1. Behavioral characterization of mouse models of neuroferritinopathy.

    PubMed

    Capoccia, Sara; Maccarinelli, Federica; Buffoli, Barbara; Rodella, Luigi F; Cremona, Ottavio; Arosio, Paolo; Cirulli, Francesca

    2015-01-01

    Ferritin is the main intracellular protein of iron storage with a central role in the regulation of iron metabolism and detoxification. Nucleotide insertions in the last exon of the ferritin light chain cause a neurodegenerative disease known as Neuroferritinopathy, characterized by iron deposition in the brain, particularly in the cerebellum, basal ganglia and motor cortex. The disease progresses relentlessly, leading to dystonia, chorea, motor disability and neuropsychiatry features. The characterization of a good animal model is required to compare and contrast specific features with the human disease, in order to gain new insights on the consequences of chronic iron overload on brain function and behavior. To this aim we studied an animal model expressing the pathogenic human FTL mutant 498InsTC under the phosphoglycerate kinase (PGK) promoter. Transgenic (Tg) mice showed strong accumulation of the mutated protein in the brain, which increased with age, and this was accompanied by brain accumulation of ferritin/iron bodies, the main pathologic hallmark of human neuroferritinopathy. Tg-mice were tested throughout development and aging at 2-, 8- and 18-months for motor coordination and balance (Beam Walking and Footprint tests). The Tg-mice showed a significant decrease in motor coordination at 8 and 18 months of age, with a shorter latency to fall and abnormal gait. Furthermore, one group of aged naïve subjects was challenged with two herbicides (Paraquat and Maneb) known to cause oxidative damage. The treatment led to a paradoxical increase in behavioral activation in the transgenic mice, suggestive of altered functioning of the dopaminergic system. Overall, data indicate that mice carrying the pathogenic FTL498InsTC mutation show motor deficits with a developmental profile suggestive of a progressive pathology, as in the human disease. These mice could be a powerful tool to study the neurodegenerative mechanisms leading to the disease and help developing

  2. TGN1412 Induces Lymphopenia and Human Cytokine Release in a Humanized Mouse Model.

    PubMed

    Weißmüller, Sabrina; Kronhart, Stefanie; Kreuz, Dorothea; Schnierle, Barbara; Kalinke, Ulrich; Kirberg, Jörg; Hanschmann, Kay-Martin; Waibler, Zoe

    2016-01-01

    Therapeutic monoclonal antibodies (mAbs) such as the superagonistic, CD28-specific antibody TGN1412, or OKT3, an anti-CD3 mAb, can cause severe adverse events including cytokine release syndrome. A predictive model for mAb-mediated adverse effects, for which no previous knowledge on severe adverse events to be expected or on molecular mechanisms underlying is prerequisite, is not available yet. We used a humanized mouse model of human peripheral blood mononuclear cell-reconstituted NOD-RAG1-/-Aβ-/-HLADQ(tg+ or tg-)IL-2Rγc-/- mice to evaluate its predictive value for preclinical testing of mAbs. 2-6 hours after TGN1412 treatment, mice showed a loss of human CD45+ cells from the peripheral blood and loss of only human T cells after OKT3 injection, reminiscent of effects observed in mAb-treated humans. Moreover, upon OKT3 injection we detected selective CD3 downmodulation on T cells, a typical effect of OKT3. Importantly, we detected release of human cytokines in humanized mice upon both OKT3 and TGN1412 application. Finally, humanized mice showed severe signs of illness, a rapid drop of body temperature, and succumbed to antibody application 2-6 hours after administration. Hence, the humanized mouse model used here reproduces several effects and adverse events induced in humans upon application of the therapeutic mAbs OKT3 and TGN1412. PMID:26959227

  3. Direct production of mouse disease models by embryo microinjection of TALENs and oligodeoxynucleotides

    PubMed Central

    Wefers, Benedikt; Meyer, Melanie; Ortiz, Oskar; Hrabé de Angelis, Martin; Hansen, Jens; Wurst, Wolfgang; Kühn, Ralf

    2013-01-01

    The study of genetic disease mechanisms relies mostly on targeted mouse mutants that are derived from engineered embryonic stem (ES) cells. Nevertheless, the establishment of mutant ES cells is laborious and time-consuming, restricting the study of the increasing number of human disease mutations discovered by high-throughput genomic analysis. Here, we present an advanced approach for the production of mouse disease models by microinjection of transcription activator-like effector nucleases (TALENs) and synthetic oligodeoxynucleotides into one-cell embryos. Within 2 d of embryo injection, we created and corrected chocolate missense mutations in the small GTPase RAB38; a regulator of intracellular vesicle trafficking and phenotypic model of Hermansky-Pudlak syndrome. Because ES cell cultures and targeting vectors are not required, this technology enables instant germline modifications, making heterozygous mutants available within 18 wk. The key features of direct mutagenesis by TALENs and oligodeoxynucleotides, minimal effort and high speed, catalyze the generation of future in vivo models for the study of human disease mechanisms and interventions. PMID:23426636

  4. TGN1412 Induces Lymphopenia and Human Cytokine Release in a Humanized Mouse Model

    PubMed Central

    Weißmüller, Sabrina; Kronhart, Stefanie; Kreuz, Dorothea; Schnierle, Barbara; Kalinke, Ulrich; Kirberg, Jörg; Hanschmann, Kay-Martin; Waibler, Zoe

    2016-01-01

    Therapeutic monoclonal antibodies (mAbs) such as the superagonistic, CD28-specific antibody TGN1412, or OKT3, an anti-CD3 mAb, can cause severe adverse events including cytokine release syndrome. A predictive model for mAb-mediated adverse effects, for which no previous knowledge on severe adverse events to be expected or on molecular mechanisms underlying is prerequisite, is not available yet. We used a humanized mouse model of human peripheral blood mononuclear cell-reconstituted NOD-RAG1-/-Aβ-/-HLADQ(tg+ or tg-)IL-2Rγc-/- mice to evaluate its predictive value for preclinical testing of mAbs. 2–6 hours after TGN1412 treatment, mice showed a loss of human CD45+ cells from the peripheral blood and loss of only human T cells after OKT3 injection, reminiscent of effects observed in mAb-treated humans. Moreover, upon OKT3 injection we detected selective CD3 downmodulation on T cells, a typical effect of OKT3. Importantly, we detected release of human cytokines in humanized mice upon both OKT3 and TGN1412 application. Finally, humanized mice showed severe signs of illness, a rapid drop of body temperature, and succumbed to antibody application 2–6 hours after administration. Hence, the humanized mouse model used here reproduces several effects and adverse events induced in humans upon application of the therapeutic mAbs OKT3 and TGN1412. PMID:26959227

  5. MRI detection of early bone metastases in B16 mouse melanoma models

    PubMed Central

    Gauvain, Karen M.; Garbow, Joel R.; Song, Sheng-Kwei; Hirbe, Angela C.; Weilbaecher, Katherine

    2009-01-01

    Bone metastasis causes significant morbidity in cancer patients, including bone pain, pathologic fractures, nerve compression syndrome, and hypercalcemia. Animal models are utilized to study the pathogenesis of skeletal metastases and to evaluate potential therapeutic agents. Previously published methods for imaging bone metastasis in rodent models have focused on identifying advanced stage metastasis using simple X-rays. Here we report MRI as a method for detecting early bone metastases in mouse models in vivo. B16 mouse melanoma cells were injected into the left cardiac ventricle of C57BL/6 mice and magnetic resonance (MR) images were obtained of the left leg following the development of metastatic disease, when tumor associated bone destruction was histologically present but not visible by X-ray. T1 and T2 relaxation times of bone marrow were measured in healthy control mice and B16 melanoma tumor-bearing mice. Mean T2 values for normal marrow were 28 ms (SD 5) and for diseased bone marrow were 41 ms (SD 3). T2 relaxation time of diseased bone marrow is significantly longer than that of normal bone marrow (P < 0.0001) and can be used as a marker of early bone metastases. These studies demonstrate that MR imaging can detect bone marrow metastases in small animals prior to development of cortical bone loss identified by X-ray. PMID:16283483

  6. Evaluation of an in vitro toxicogenetic mouse model for hepatotoxicity

    SciTech Connect

    Martinez, Stephanie M.; Bradford, Blair U.; Soldatow, Valerie Y.; Witek, Rafal; Kaiser, Robert; Stewart, Todd; Amaral, Kirsten; Freeman, Kimberly; Black, Chris; LeCluyse, Edward L.; Ferguson, Stephen S.

    2010-12-15

    Numerous studies support the fact that a genetically diverse mouse population may be useful as an animal model to understand and predict toxicity in humans. We hypothesized that cultures of hepatocytes obtained from a large panel of inbred mouse strains can produce data indicative of inter-individual differences in in vivo responses to hepato-toxicants. In order to test this hypothesis and establish whether in vitro studies using cultured hepatocytes from genetically distinct mouse strains are feasible, we aimed to determine whether viable cells may be isolated from different mouse inbred strains, evaluate the reproducibility of cell yield, viability and functionality over subsequent isolations, and assess the utility of the model for toxicity screening. Hepatocytes were isolated from 15 strains of mice (A/J, B6C3F1, BALB/cJ, C3H/HeJ, C57BL/6J, CAST/EiJ, DBA/2J, FVB/NJ, BALB/cByJ, AKR/J, MRL/MpJ, NOD/LtJ, NZW/LacJ, PWD/PhJ and WSB/EiJ males) and cultured for up to 7 days in traditional 2-dimensional culture. Cells from B6C3F1, C57BL/6J, and NOD/LtJ strains were treated with acetaminophen, WY-14,643 or rifampin and concentration-response effects on viability and function were established. Our data suggest that high yield and viability can be achieved across a panel of strains. Cell function and expression of key liver-specific genes of hepatocytes isolated from different strains and cultured under standardized conditions are comparable. Strain-specific responses to toxicant exposure have been observed in cultured hepatocytes and these experiments open new opportunities for further developments of in vitro models of hepatotoxicity in a genetically diverse population.

  7. Of Mice & Men: Advancements in the Understanding of Down Syndrome

    ERIC Educational Resources Information Center

    Silverman, Wayne

    2007-01-01

    Mice have become the model of choice for studies of Down syndrome due to the fact that mouse chromosome 16 bears a striking resemblance to human chromosome 21. This has allowed researchers to create various mouse models of Down syndrome, but this is a tricky business on many levels. Great expertise is required to manipulate DNA to create these…

  8. Neurocognitive endophenotypes in CGG KI and Fmr1 KO mouse models of Fragile X-Associated disorders: an analysis of the state of the field

    PubMed Central

    Hunsaker, Michael R.

    2013-01-01

    It has become increasingly important that the field of behavioral genetics identifies not only the gross behavioral phenotypes associated with a given mutation, but also the behavioral endophenotypes that scale with the dosage of the particular mutation being studied. Over the past few years, studies evaluating the effects of the polymorphic CGG trinucleotide repeat on the FMR1 gene underlying Fragile X-Associated Disorders have reported preliminary evidence for a behavioral endophenotype in human Fragile X Premutation carrier populations as well as the CGG knock-in (KI) mouse model. More recently, the behavioral experiments used to test the CGG KI mouse model have been extended to the Fmr1 knock-out (KO) mouse model. When combined, these data provide compelling evidence for a clear neurocognitive endophenotype in the mouse models of Fragile X-Associated Disorders such that behavioral deficits scale predictably with genetic dosage. Similarly, it appears that the CGG KI mouse effectively models the histopathology in Fragile X-Associated Disorders across CGG repeats well into the full mutation range, resulting in a reliable histopathological endophenotype. These endophenotypes may influence future research directions into treatment strategies for not only Fragile X Syndrome, but also the Fragile X Premutation and Fragile X-Associated Tremor/Ataxia Syndrome (FXTAS). PMID:24627796

  9. Animal model of neuropathic tachycardia syndrome

    NASA Technical Reports Server (NTRS)

    Carson, R. P.; Appalsamy, M.; Diedrich, A.; Davis, T. L.; Robertson, D.

    2001-01-01

    Clinically relevant autonomic dysfunction can result from either complete or partial loss of sympathetic outflow to effector organs. Reported animal models of autonomic neuropathy have aimed to achieve complete lesions of sympathetic nerves, but incomplete lesions might be more relevant to certain clinical entities. We hypothesized that loss of sympathetic innervation would result in a predicted decrease in arterial pressure and a compensatory increase in heart rate. Increased heart rate due to loss of sympathetic innervation is seemingly paradoxical, but it provides a mechanistic explanation for clinical autonomic syndromes such as neuropathic postural tachycardia syndrome. Partially dysautonomic animals were generated by selectively lesioning postganglionic sympathetic neurons with 150 mg/kg 6-hydroxydopamine hydrobromide in male Sprague-Dawley rats. Blood pressure and heart rate were monitored using radiotelemetry. Systolic blood pressure decreased within hours postlesion (Delta>20 mm Hg). Within 4 days postlesion, heart rate rose and remained elevated above control levels. The severity of the lesion was determined functionally and pharmacologically by spectral analysis and responsiveness to tyramine. Low-frequency spectral power of systolic blood pressure was reduced postlesion and correlated with the diminished tyramine responsiveness (r=0.9572, P=0.0053). The tachycardia was abolished by treatment with the beta-antagonist propranolol, demonstrating that it was mediated by catecholamines acting on cardiac beta-receptors. Partial lesions of the autonomic nervous system have been hypothesized to underlie many disorders, including neuropathic postural tachycardia syndrome. This animal model may help us better understand the pathophysiology of autonomic dysfunction and lead to development of therapeutic interventions.

  10. Improvements and Limitations of Humanized Mouse Models for HIV Research: NIH/NIAID "Meet the Experts" 2015 Workshop Summary.

    PubMed

    Akkina, Ramesh; Allam, Atef; Balazs, Alejandro B; Blankson, Joel N; Burnett, John C; Casares, Sofia; Garcia, J Victor; Hasenkrug, Kim J; Kashanchi, Fatah; Kitchen, Scott G; Klein, Florian; Kumar, Priti; Luster, Andrew D; Poluektova, Larisa Y; Rao, Mangala; Sanders-Beer, Brigitte E; Shultz, Leonard D; Zack, Jerome A

    2016-02-01

    The number of humanized mouse models for the human immunodeficiency virus (HIV)/acquired immunodeficiency syndrome (AIDS) and other infectious diseases has expanded rapidly over the past 8 years. Highly immunodeficient mouse strains, such as NOD/SCID/gamma chain(null) (NSG, NOG), support better human hematopoietic cell engraftment. Another improvement is the derivation of highly immunodeficient mice, transgenic with human leukocyte antigens (HLAs) and cytokines that supported development of HLA-restricted human T cells and heightened human myeloid cell engraftment. Humanized mice are also used to study the HIV reservoir using new imaging techniques. Despite these advances, there are still limitations in HIV immune responses and deficits in lymphoid structures in these models in addition to xenogeneic graft-versus-host responses. To understand and disseminate the improvements and limitations of humanized mouse models to the scientific community, the NIH sponsored and convened a meeting on April 15, 2015 to discuss the state of knowledge concerning these questions and best practices for selecting a humanized mouse model for a particular scientific investigation. This report summarizes the findings of the NIH meeting. PMID:26670361

  11. Characterization and expression analysis of the Spink5 gene, the mouse ortholog of the defective gene in Netherton syndrome.

    PubMed

    Galliano, Marie Florence; Roccasecca, Rosa Maria; Descargues, Pascal; Micheloni, Alessia; Levy, Elaine; Zambruno, Giovanna; D'Alessio, Marina; Hovnanian, Alain

    2005-04-01

    The human SPINK5 gene, encoding the putative 15-domain serine protease inhibitor LEKTI, was identified as the defective gene in the severe autosomal recessive ichthyosiform skin disorder known as Netherton syndrome and as a candidate susceptibility gene for atopic disease. Here we report mapping of the murine Spink5 gene to chromosome 18 and its characterization. We show that, unlike in humans, transcription of the mouse Spink5 gene generates two mRNAs that differ in the 3' untranslated region. The encoded protein, which is detected in differentiated primary cultured keratinocytes and mouse skin as an approximately 130-kDa glycosylated precursor, displays approximately 60% identity with its human counterpart but lacks the human LEKTI domain 6. As in the human, mouse Lekti represents a marker of epithelial differentiation, strongly expressed in the granular layer of the epidermis, in suprabasal layers of stratified epithelia, and in thymic Hassall's bodies. Our data indicate that mouse Spink5/Lekti, like its human counterpart, is involved in the control of epithelial tissue homeostasis, but also highlight specific features of the murine gene and protein. PMID:15780751

  12. A novel surgical approach for intratracheal administration of bioactive agents in a fetal mouse model.

    PubMed

    Carlon, Marianne S; Toelen, Jaan; da Cunha, Marina Mori; Vidović, Dragana; Van der Perren, Anke; Mayer, Steffi; Sbragia, Lourenço; Nuyts, Johan; Himmelreich, Uwe; Debyser, Zeger; Deprest, Jan

    2012-01-01

    Prenatal pulmonary delivery of cells, genes or pharmacologic agents could provide the basis for new therapeutic strategies for a variety of genetic and acquired diseases. Apart from congenital or inherited abnormalities with the requirement for long-term expression of the delivered gene, several non-inherited perinatal conditions, where short-term gene expression or pharmacological intervention is sufficient to achieve therapeutic effects, are considered as potential future indications for this kind of approach. Candidate diseases for the application of short-term prenatal therapy could be the transient neonatal deficiency of surfactant protein B causing neonatal respiratory distress syndrome(1,2) or hyperoxic injuries of the neonatal lung(3). Candidate diseases for permanent therapeutic correction are Cystic Fibrosis (CF)(4), genetic variants of surfactant deficiencies(5) and α1-antitrypsin deficiency(6). Generally, an important advantage of prenatal gene therapy is the ability to start therapeutic intervention early in development, at or even prior to clinical manifestations in the patient, thus preventing irreparable damage to the individual. In addition, fetal organs have an increased cell proliferation rate as compared to adult organs, which could allow a more efficient gene or stem cell transfer into the fetus. Furthermore, in utero gene delivery is performed when the individual's immune system is not completely mature. Therefore, transplantation of heterologous cells or supplementation of a non-functional or absent protein with a correct version should not cause immune sensitization to the cell, vector or transgene product, which has recently been proven to be the case with both cellular and genetic therapies(7). In the present study, we investigated the potential to directly target the fetal trachea in a mouse model. This procedure is in use in larger animal models such as rabbits and sheep(8), and even in a clinical setting(9), but has to date not been

  13. Vascularization of engineered cartilage constructs in a mouse model.

    PubMed

    Burghartz, Marc; Gehrke, Thomas; Storck, Katharina; Staudenmaier, Rainer; Mandlik, Veronika; Schurr, Christian; Hoang, Nguyen; Hagen, Rudolf; Kleinsasser, Norbert

    2