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Mice Deficient (mouse + deficient)
Kinds of Mice Deficient Selected AbstractsDecreased Pulmonary Inflammation Following Ethanol and Burn Injury in Mice Deficient in TLR4 but not TLR2 SignalingALCOHOLISM, Issue 10 2010Melanie D. Bird Background:, Clinical and laboratory evidence suggests that alcohol consumption prior to burn injury leads to dysregulated immune function and subsequent higher rates of morbidity and mortality. Our laboratory previously observed higher levels of pro-inflammatory cytokines and leukocyte infiltration in the lungs of mice following ethanol and burn injury. To understand the mechanism of the increased inflammatory response, we looked at different signaling initiators of inflammation including toll-like receptors 2 and 4 (TLR2 and 4) pathways. Methods:, Wild-type, TLR2, and TLR4 knockout mice were treated with vehicle or a single binge dose of ethanol (1.11 g/kg) and subsequently given a sham or burn injury. Twenty-four hours postinjury, systemic and pulmonary levels of pro-inflammatory cytokines were quantified, and differences in neutrophil infiltration were determined by histological examination. Results:, Higher numbers of neutrophils were observed in the lungs of wild-type mice following the combined insult of ethanol and burn injury relative to either injury alone. This increase in leukocyte accumulation was absent in the TLR4 knockout mice. Circulating levels of IL-6 and tumor necrosis factor-, were also elevated in wild-type mice but not in TLR4 knockout mice. Consistent with these findings, pulmonary levels of KC and IL-6 were increased in wild-type mice following burn and ethanol compared to burn injury alone as well as to their TLR4 knockout counterparts. In contrast, TLR2 knockout mice displayed similar levels, to wild-type mice, of neutrophil infiltration as well as IL-6 and KC in the lung. Conclusions:, These data suggest that TLR4 signaling is a crucial contributory component in the exuberant inflammation after ethanol and burn injury. However, TLR2 does not appear to play a vital role in the aberrant pulmonary inflammation. [source] Macrophage-Related Demyelination In Peripheral Nerves Of Mice Deficient In The Gap Junction Protein Connexin 32JOURNAL OF THE PERIPHERAL NERVOUS SYSTEM, Issue 3 2002I Kobsar Mice deficient in the gap junction protein connexin 32 (Cx32) develop a slowly progressing demyelinating neuropathy, with enlarged periaxonal collars, abnormal non-compacted myelin domains and axonal sprouts. These mice serve as a model for the X-linked form of inherited demyelin- ating neuropathies in humans. Based on our previous findings that macrophages are involved in demyelination in other myelin mutants (i.e. mice heterozygously deficient in P0), we considered the possibility that macrophages might be also mediators of demyelination in Cx32-deficient mice. Indeed, we detected an age-related increase in the number of macrophages in demyelinating nerves of Cx32-deficient mice. In addition, immunoelectron microscopy revealed macrophages in an apposition to degenerating myelin reminiscent of a macrophage-mediated demyelinating neuropathy. We conclude that involvement of macrophages might be a widespread phenomenon in genetically-determined demyelination. [source] The SDF-1/CXCR4 pathway and the development of the cerebellar systemEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 8 2005Tim O. Vilz Abstract Mice deficient for the chemokine receptor CXCR4 show premature translocation of granule cell neuroblasts from their germinal zone into the nascent cerebellum [Y.-R. Zuo et al. (1998)Nature, 393, 595,599]. Here, we used CXCR4-null mice to analyse the early development of cerebellar cortical inhibitory interneurons and pontine neurons which, in the adult, are synaptically integrated with granule cells. Cortical inhibitory interneuronal precursors normally invade the cerebellar anlage of CXCR4-deficient mice, but their dispersal is impeded by dislocated foci of proliferating granule cells, from which they are excluded. This is reminiscent of the strict exclusion of inhibitory interneuronal precursors from the superficial external granule cell layer. As inhibitory interneuronal precursors readily mingle with post-mitotic granule cells both in wild-type and CXCR4-null mice, these findings indicate that the developmentally regulated interactions between granule and inhibitory interneuronal precursors are independent of SDF-1/CXCR4 signalling. In contrast, the transit of pontine neurons from the rhombic lip through the anterior extramural stream to the basilar pons is disrupted in CXCR4-deficient animals. Migrating pontine neurons express CXCR4, and in CXCR4-null animals these cells are found displaced deep into the brainstem. Consequently, nascent pontine nuclei in CXCR4-deficient animals are hypoplastic. Moreover, they fail to express plexin D1, suggesting that SDF-1/CXCR4 signalling may also impinge on axon guidance critical to the orderly formation of granule cell mossy fibre afferents. [source] Obesity and metabolic syndrome in histone demethylase JHDM2a-deficient miceGENES TO CELLS, Issue 8 2009Takeshi Inagaki Histone H3 lysine 9 (H3K9) methylation is a crucial epigenetic mark of heterochromatin formation and transcriptional silencing. Recent studies demonstrated that most covalent histone lysine modifications are reversible and the jumonji C (JmjC)-domain-containing proteins have been shown to possess such demethylase activities. However, there is little information available on the biological roles of histone lysine demethylation in intact animal model systems. JHDM2A (JmjC-domain-containing histone demethylase 2A, also known as JMJD1A) catalyses removal of H3K9 mono- and dimethylation through iron and ,-ketoglutarate dependent oxidative reactions. Here, we demonstrate that JHDM2a also regulates metabolic genes related to energy homeostasis including anti-adipogenesis, regulation of fat storage, glucose transport and type 2 diabetes. Mice deficient in JHDM2a (JHDM2a,/,) develop adult onset obesity, hypertriglyceridemia, hypercholesterolemia, hyperinsulinemia and hyperleptinemia, which are hallmarks of metabolic syndrome. JHDM2a,/, mice furthermore exhibit fasted induced hypothermia indicating reduced energy expenditure and also have a higher respiratory quotient indicating less fat utilization for energy production. These observations may explain the obesity phenotype in these mice. Thus, H3K9 demethylase JHDM2a is a crucial regulator of genes involved in energy expenditure and fat storage, which suggests it is a previously unrecognized key regulator of obesity and metabolic syndrome. [source] The impact of joint bleeding and synovitis on physical ability and joint function in a murine model of haemophilic synovitisHAEMOPHILIA, Issue 1 2008C. MEJIA-CARVAJAL Summary., Haemophilia is a congenital disorder that commonly results in musculoskeletal bleeding and orthopaedic complications. After an acute joint haemorrhage, an increase in intra-articular pressure and inflammation cause pain, swelling and limited motion. Blood in the joint space provokes a proliferative disorder known as haemophilic synovitis. Overgrowth of the synovial membrane causes mechanical dysfunction. Eventually, there is destruction of the articular surface and underlying bone. The aim of this project was to test the hypothesis that a minimum number of haemarthroses negatively impacts on joint function and that this would be reflected by decreased physical performance of experimental animals. Mice deficient in factor VIII coagulant activity were trained to ambulate on a rotating rod then injured three times at weekly intervals. Their ability to walk was then compared to a group of uninjured mice. Cohorts of mice were killed after 1, 2 or 3 months and the knee joints examined by gross and histological methods. The results supported the following conclusions: (i) haemophilic mice can be trained to ambulate on a rotating rod; (ii) acute hemarthrosis temporarily impairs their ability to ambulate and (iii) following recovery from acute injury, mice developing synovitis demonstrated inferior physical ability compared to mice not developing synovitis. This is the first description of a quantitative assay to monitor joint function in experimental animals and should be useful to evaluate the efficacy of new therapies developed to prevent and treat bleeding and to test strategies to counter the devastating effects of synovitis. [source] CX3CL1-CX3CR1 interaction prevents carbon tetrachloride-induced liver inflammation and fibrosis in mice,HEPATOLOGY, Issue 4 2010Tomonori Aoyama Chronic liver disease is associated with hepatocyte injury, inflammation, and fibrosis. Chemokines and chemokine receptors are key factors for the migration of inflammatory cells such as macrophages and noninflammatory cells such as hepatic stellate cells (HSCs). The expression of CX3CR1 and its ligand, CX3CL1, is up-regulated in chronic liver diseases such as chronic hepatitis C. However, the precise role of CX3CR1 in the liver is still unclear. Here we investigated the role of the CX3CL1-CX3CR1 interaction in a carbon tetrachloride (CCl4),induced liver inflammation and fibrosis model. CX3CR1 was dominantly expressed in Kupffer cells in the liver. In contrast, the main source of CX3CL1 was HSCs. Mice deficient in CX3CR1 showed significant increases in inflammatory cell recruitment and cytokine production [including tumor necrosis factor , (TNF-,); monocyte chemoattractant protein 1; macrophage inflammatory protein 1,; and regulated upon activation, normal T cell expressed, and secreted (RANTES)] after CCl4 treatment versus wild-type (WT) mice. This suggested that CX3CR1 signaling prevented liver inflammation. Kupffer cells in CX3CR1-deficient mice after CCl4 treatment showed increased expression of TNF-, and transforming growth factor , and reduced expression of the anti-inflammatory markers interleukin-10 (IL-10) and arginase-1. Coculture experiments showed that HSCs experienced significantly greater activation by Kupffer cells from CCl4 -treated CX3CR1-deficient mice versus WT mice. Indeed, augmented fibrosis was observed in CX3CR1-deficient mice versus WT mice after CCl4 treatment. Finally, CX3CL1 treatment induced the expression of IL-10 and arginase-1 in WT cultured Kupffer cells through CX3CR1, which in turn suppressed HSC activation. Conclusion: The CX3CL1-CX3CR1 interaction inhibits inflammatory properties in Kupffer cells/macrophages and results in decreased liver inflammation and fibrosis. (Hepatology 2010) [source] An inhibitor of cyclin-dependent kinase, stress-induced p21Waf-1/Cip-1, mediates hepatocyte mito-inhibition during the evolution of cirrhosis,HEPATOLOGY, Issue 6 2005John G. Lunz III During the evolution of cirrhosis, there is a relative decrease in volume percentage of hepatocytes and a relative increase in biliary epithelial cells and myofibroblasts. This is recognized histopathologically as a ductular reaction and leads to gradual distortion of the normal hepatic architecture. The final or decompensated stage of cirrhosis is characterized by a further decline in hepatocyte proliferation and loss of functional liver mass that manifests clinically as ascites, encephalopathy, and other signs of liver failure. In this report, we tested the hypothesis that p21-mediated hepatocyte mito-inhibition accelerates the evolution of cirrhosis using an established mouse model of decompensated biliary cirrhosis, p21-deficient mice, and liver tissue from humans awaiting liver replacement. Despite the same insult of long-term (12-week) bile duct ligation, mice prone to decompensation showed significantly more oxidative stress and hepatocyte nuclear p21 expression, which resulted in less hepatocyte proliferation, an exaggerated ductular reaction, and more advanced disease compared with compensation-prone controls. Mice deficient in p21 were better able than wild-type controls to compensate for long-term bile duct ligation because of significantly greater hepatocyte proliferation, which led to a larger liver mass and less architectural distortion. Mito-inhibitory hepatocyte nuclear p21 expression in humans awaiting liver replacement directly correlated with pathological disease stage and model of end-stage liver disease scoring. In conclusion, stress-induced upregulation of hepatocyte p21 inhibits hepatocyte proliferation during the evolution of cirrhosis. These findings have implications for understanding the evolution of cirrhosis and associated carcinogenesis. Supplementary material for this article can be found on the HEPATOLOGY website (http://interscience.wiley.com/jpages/0270-9139/suppmat/index.html). (HEPATOLOGY 2005.) [source] Hepatocarcinogenesis in Female Mice With Mosaic Expression of Connexin32HEPATOLOGY, Issue 3 2000Oliver Moennikes Mice deficient for connexin32 (Cx32), the major gap junction forming protein in liver, are highly susceptible to hepatocarcinogenesis. Because the Cx32 gene is located on the X-chromosome, heterozygous females show mosaicism with respect to Cx32 expression; this enables their use in studying the effect of Cx32-deficiency in a mixed Cx32-plus/Cx32-minus environment in vivo. Female C3H/He mice (Cx32+/+) were crossed with Cx32-deficient C57BL/129Sv males (Cx32Y/- ) to yield F1 females heterozygous with respect to Cx32 (Cx32+/,). Patches of hepatocytes were observed in normal liver that either expressed Cx32 or failed to express the protein. The mean fraction of Cx32-negative tissue in liver was about 60% and did not change significantly with age of mice. Neoplastic liver lesions, induced in weanling mice, were identified in serial liver sections by their deficiency in glucose-6-phosphatase staining. Parallel sections were used for immunohistochemical demonstration of Cx32 protein. Smaller lesions were either homogenously Cx32-negative or showed unchanged to slightly elevated levels of Cx32 protein. There were no major differences in number and size distribution between lesions of these 2 phenotypes. In addition, larger lesions were mostly Cx32-negative but often contained embedded patches of Cx32-positive cells. Staining for the proliferation-associated nuclear antigen Ki-67 did not reveal significant differences between Cx32-negative and Cx32-positive hepatocytes in Cx32-mosaic tumors. This suggests that expression of Cx32 within a subpopulation of tumor cells does not negatively regulate their growth nor does it seem to affect the proliferation of their directly neighboring Cx32-negative counterparts. [source] The lack of RNA-dependent protein kinase enhances susceptibility of mice to genital herpes simplex virus type 2 infectionIMMUNOLOGY, Issue 4 2006Daniel J. J. Carr Summary Mice deficient in RNA-dependent protein kinase (PKR,/,) or deficient in PKR and a functional 2,,5,-oligoadenylate synthetase (OAS) pathway (PKR/RL,/,) are more susceptible to genital herpes simplex virus type 2 (HSV-2) infection than wild-type mice or mice that are deficient only in a functional OAS pathway (RL,/,) as measured by survival over 30 days. The increase in susceptibility correlated with an increase in virus titre recovered from vaginal tissue or brainstem of infected mice during acute infection. There was also an increase in CD45+ cells and CD8+ T cells residing in the central nervous system of HSV-2-infected PKR/RL,/, mice in comparison with RL,/, or wild-type control animals. In contrast, there was a reduction in the HSV-specific CD8+ T cells within the draining lymph node of the PKR/RL,/, mice. Collectively, activation of PKR, but not of OAS, contributes significantly to the local control and spread of HSV-2 following genital infection. [source] Runt-related transcription factor 3 is associated with ulcerative colitis and shows epistasis with solute carrier family 22, members 4 and 5INFLAMMATORY BOWEL DISEASES, Issue 12 2008Rinse K. Weersma MD Abstract Background: Inflammatory bowel disease (IBD), comprising Crohn's disease (CD) and ulcerative colitis (UC), are intestinal inflammatory disorders with a complex genetic background. Mice deficient for the runt-domain-transcription-factor3 (Runx3) develop spontaneous colitis. Human RUNX3 resides in an IBD-susceptibility locus. We studied the association of RUNX3 in a cohort of IBD patients and analyzed the interaction with SLC22A4/5. RUNX3 and OCTN1 mRNA expression was assessed in inflamed and noninflamed mucosa from patients and controls. Methods: 543 IBD patients (309 CD / 234 UC) and 296 controls were included. Four single nucleotide polymorphisms (SNPs) and 4 microsatellite markers were studied for RUNX3. Five SNPs (including SNP-207G,C and SNP1672C,T) were analyzed for SLC22A4/5. RUNX3, and OCTN1 expression in mucosal tissue from 30 patients (14 UC / 16 CD) and 6 controls were determined by quantitative polymerase chain reaction. Results: A significant association between RUNX3 -SNP rs2236851 and UC (OR 1.61; 95% confidence interval [CI] 1.11,2.32, P = 0.020) was found. Carriership is associated with pancolitis (odds ratio [OR] 1.86; 95% CI 1.08,3.21). SLC22A4/5 -SNPs rs272893 and rs273900 are associated with CD (OR 2.16; 95% CI 1.21,3.59 and OR 2.40; 95% CI 1.43,4.05). We found epistasis for carriership of a risk-associated allele in RUNX3 and SLC22A4/5 for UC patients versus CD patients (OR 3.83; 95% CI 1.26,11.67). RUNX3 mRNA expression is increased (P = 0.01) in inflamed colonic mucosa of UC patients compared to noninflamed mucosa and controls. Conclusions: We provide evidence for the genetic association of RUNX3 with UC and for CD with the IBD5 locus including SLC22A4/5. An epistatic effect of RUNX3 and SLC22A4 was associated with an increased risk for UC. Our data suggest a role for RUNX3 in UC susceptibility. (Inflamm Bowel Dis 2008) [source] Regional and cellular distribution of mitochondrial ferritin in the mouse brainJOURNAL OF NEUROSCIENCE RESEARCH, Issue 14 2010Amanda M. Snyder Abstract Iron and mitochondrial dysfunction are important in many neurodegenerative diseases. Several iron transport proteins have been identified that are associated with mitochondria, most recently mitochondrial ferritin. Here we describe the cellular distribution of mitochondrial ferritin in multiple regions of the brain in C57/BL6 mice. Mitochondrial ferritin was found in all regions of the brain, although staining intensity varied between regions. Mitochondrial ferritin was detected throughout the layers of cerebral cortex and in the cerebellum, hippocampus, striatum, choroid plexus, and ependymal cells. The cell type in the brain that stains most prominently for mitochondrial ferritin is neuronal, but oligodendrocytes also stain strongly in both gray matter and in white matter tracts. Mice deficient in H-ferritin do not differ in the mitochondrial ferritin staining pattern or intensity compared with C57/BL6 mice, suggesting that there is no compensatory expression of these proteins. In addition, by using inbred mouse strains with differing levels of iron content, we have shown that regional brain iron content does not affect expression of mitochondria ferritin. The expression of mitochondria ferritin appears to be more influenced by mitochondrial density. Indeed, at an intracellular level, mitochondrial ferritin immunoreaction product is strongest where mitochondrial density is high, as seen in the ependymal cells. Given the importance and relationship between iron and mitochondrial activity, understanding the role of mitochondrial ferritin can be expected to contribute to our knowledge of mitochondrial dysfunction and neurodegenerative disease. © 2010 Wiley-Liss, Inc. [source] Macrophage-Related Demyelination In Peripheral Nerves Of Mice Deficient In The Gap Junction Protein Connexin 32JOURNAL OF THE PERIPHERAL NERVOUS SYSTEM, Issue 3 2002I Kobsar Mice deficient in the gap junction protein connexin 32 (Cx32) develop a slowly progressing demyelinating neuropathy, with enlarged periaxonal collars, abnormal non-compacted myelin domains and axonal sprouts. These mice serve as a model for the X-linked form of inherited demyelin- ating neuropathies in humans. Based on our previous findings that macrophages are involved in demyelination in other myelin mutants (i.e. mice heterozygously deficient in P0), we considered the possibility that macrophages might be also mediators of demyelination in Cx32-deficient mice. Indeed, we detected an age-related increase in the number of macrophages in demyelinating nerves of Cx32-deficient mice. In addition, immunoelectron microscopy revealed macrophages in an apposition to degenerating myelin reminiscent of a macrophage-mediated demyelinating neuropathy. We conclude that involvement of macrophages might be a widespread phenomenon in genetically-determined demyelination. [source] Mice deficient for RNA-binding protein brunol1 show reduction of spermatogenesis but are fertileMOLECULAR REPRODUCTION & DEVELOPMENT, Issue 11 2007Arvind Dev Abstract RNA-binding proteins are involved in post-transcriptional processes like mRNA stabilization, alternative splicing, and transport. Brunol1 is a novel mouse gene related to elav/Bruno family of genes encoding for RNA-binding proteins. We report here the expression and functional analysis of murine Brunol1. Expression analysis of Brunol1 during embryogenesis by RT-PCR showed that Brunol1 expression starts at 9.5 dpc and continues to the later stages of embryonic development. In adult mice, the Brunol1 expression is restricted to brain and testis. We also analyzed the Brunol1 expression in testes of different mutants with spermatogenesis defects: W/WV, Tfm/y, Leyl,/,, olt/olt, and qk/qk. Brunol1 transcript was detectable in Leyl,/,, olt/olt, and qk/qk mutant but not in W/WV and Tfm/y mutants. We also showed by transfection of a fusion protein of green fluorescent protein and Brunol1 protein into NIH3T3 cells, that Brunol1 is localized in cytoplasm and nucleus. In order to elucidate the function of the Brunol1 protein in spermatogenesis, we disrupted the Brunol1 locus in mouse by homologous recombination, which resulted in a complete loss of the Brunol1 transcript. Male and female Brunol1+/, and Brunol1,/, mice from genetic backgrounds C57BL/6J,×,129/Sv hybrid and 129X1/SvJ when inbred exhibited normal phenotype and are fertile, although the number and motility of sperms are significantly reduced. An intensive phenotypic analysis showed no gross abnormalities in testis morphology. Collectively our results demonstrate that Brunol1 might be nonessential protein for mouse embryonic development and spermatogenesis. Mol. Reprod. Dev. 74: 1456,1464, 2007. © 2007 Wiley-Liss, Inc. [source] Expression of aquaporins in the efferent ductules, sperm counts, and sperm motility in estrogen receptor-, deficient mice fed lab chow versus caseinMOLECULAR REPRODUCTION & DEVELOPMENT, Issue 2 2006Ricardo Ruz Abstract Estrogens play an important role in the male reproductive tract, and this is especially so for the efferent ductules, where ,-estrogen receptors (ER,) have been localized. Mice deficient in ER, (,ERKO mice) are infertile, and the effect appears to be due in part to retention of water at the level of the efferent ductules. In the present study, we examined the consequences of ER, deletion on the distribution of certain aquaporins (AQPs), water protein channels, in the efferent ductules and on sperm numbers and motility. In addition, the effects of feeding mice a regular lab chow diet, which contains phytoestrogens, known to affect male reproductive tract functions, and a casein diet, which lacks phytoestrogens, were also assessed. Light microscope immunolocalizations of AQP-1 and AQP-9 revealed dramatic reduction and patchier staining in ,ERKO mice with distal areas of the efferent ductules being more affected than proximal areas. No other changes in immunolocalizations were noted as a consequence of diet. Computer-assisted sperm analyses demonstrated a 62% reduction in cauda epididymal sperm/ml in ,ERKO mice fed lab chow, whereas 87% fewer sperm/ml were observed in ,ERKO mice fed casein, suggesting an enhanced role for sperm production and concentration in a diet containing phytoestrogens. All sperm motility parameters were altered to some degree in ,ERKO mice fed lab chow. Alterations in sperm motility parameters were also detected, but were less dramatic in ,ERKO mice fed casein. These data suggest that the decrease in AQP expression in the efferent ductules of ,ERKO mice contributes in part to water retention in this tissue, eventually leading to backflow of water into the testis, with subsequent decreases in sperm concentration and motility. The data also suggest that phytoestrogens, which are present in regular lab chow, can influence the male reproductive tract with and without the presence of ER,, promoting efferent ductule and epididymal functions when ER, is expressed, but inhibiting these same functions when ER, is missing. Taken together the data underscore the importance of estrogens and ER, in maintaining sperm maturation and preventing male infertility. Mol. Reprod. Dev. © 2005 Wiley-Liss, Inc. [source] Inducible costimulator ligand regulates bleomycin-induced lung and skin fibrosis in a mouse model independently of the inducible costimulator/inducible costimulator ligand pathwayARTHRITIS & RHEUMATISM, Issue 6 2010Chihiro Tanaka Objective Systemic sclerosis is a connective tissue disease characterized by fibrosis of the skin and internal organs, including the lungs. Inducible costimulator (ICOS), which is expressed on activated T cells, and its ligand ICOSL, which is expressed on antigen-presenting cells, have been considered a single receptor,ligand pair. Although the ICOS/ICOSL pathway is known to play various roles in adaptive immunity, its roles in innate immunity and tissue fibrosis remain unknown. Methods We assessed the roles of ICOS and ICOSL in tissue fibrosis by administering bleomycin intratracheally or intradermally into mice deficient in ICOS and/or ICOSL. Tissue fibrosis was evaluated by histologic or biochemical examination. Results ICOS deficiency attenuated the lung and skin fibrosis, whereas ICOSL deficiency aggravated it. Mice deficient in both ICOS and ICOSL exhibited accelerated fibrosis, reflecting a dominant role of ICOSL over ICOS in this model. Interestingly, ICOSL expression on macrophages and B cells derived from bronchoalveolar lavage fluid was significantly elevated in ICOS-deficient mice as compared with wild-type mice during this process. Thus, the levels of ICOSL expression on B cells and macrophages were inversely associated with the severity of tissue fibrosis. Conclusion Our results indicate that ICOSL expression on antigen-presenting cells plays a previously unknown regulatory role during the development of bleomycin-induced tissue fibrosis that is independent of the ICOS/ICOSL pathway. Further studies will be needed to clarify the roles of ICOS and ICOSL in the development of systemic sclerosis. [source] Nucleotide-binding oligomerization domain 2 and Toll-like receptor 2 function independently in a murine model of arthritis triggered by intraarticular peptidoglycanARTHRITIS & RHEUMATISM, Issue 4 2010Holly L. Rosenzweig Objective Blau syndrome is an autoinflammatory disease resulting from mutations in the NOD2 gene, wherein granulomatous arthritis, uveitis, and dermatitis develop. The mechanisms by which aberrant NOD2 causes joint inflammation are poorly understood. Indeed, very few studies have addressed the function of nucleotide-binding oligomerization domain 2 (NOD-2) in the joint. This study was undertaken to investigate NOD-2 function in an experimental model of arthritis and to explore the potential interplay between Toll-like receptor 2 (TLR-2) and NOD-2 in joint inflammation. Methods Mice deficient in TLR-2, myeloid differentiation factor 88 (MyD88), or NOD-2 and their wild-type controls were given an intraarticular injection of muramyl dipeptide (MDP), peptidoglycan (PG; a metabolite of which is MDP), or palmitoyl-3-cysteine-serine-lysine-4 (Pam3CSK4), a synthetic TLR-2 agonist. Joint inflammation was assessed by near-infrared fluorescence imaging and histologic analysis. Results Locally administered PG resulted in joint inflammation, which was markedly reduced in mice deficient in either TLR-2 or the TLR signaling mediator MyD88. In addition to TLR-2 signaling events, NOD-2 mediated joint inflammation, as evidenced by the fact that mice deficient in NOD-2 showed significantly reduced PG-induced arthritis. TLR-2 or MyD88 deficiency did not influence arthritis induced by the specific NOD-2 agonist MDP. In addition, NOD-2 deficiency did not alter the TLR-2,dependent joint inflammation elicited by the synthetic TLR-2 agonist Pam3CSK4. Conclusion Whereas NOD-2 and TLR-2 are both critical for the development of PG-induced arthritis, they appear to elicit inflammation independently of each other. Our findings indicate that NOD-2 plays an inflammatory role in arthritis. [source] The cannabinoid receptor CB2 exerts antifibrotic effects in experimental dermal fibrosisARTHRITIS & RHEUMATISM, Issue 4 2009Alfiya Akhmetshina Objective The cannabinoid receptor CB2 is predominantly expressed in non-neuronal tissue and exerts potent immunomodulatory effects. This study was undertaken to evaluate the role of CB2 in the pathogenesis of dermal fibrosis. Methods Mice deficient in CB2 (CB2,/, mice) and their wild-type littermates (CB2+/+ mice) were injected with bleomycin to induce experimental fibrosis. Mice were treated with selective agonists and antagonists of CB2. Lesional skin was evaluated for dermal thickness and numbers of infiltrating leukocytes. Bone marrow transplantation experiments were performed. Results CB2,/, mice were more sensitive to bleomycin-induced dermal fibrosis than were CB2+/+ mice, and showed increased dermal thickness. Leukocyte counts were significantly higher in the lesional skin of CB2+/+ mice. Increased dermal fibrosis was also observed upon treatment with the CB2 antagonist AM-630. In contrast, the selective CB2 agonist JWH-133 reduced leukocyte infiltration and dermal thickening. The phenotype of CB2,/, mice was mimicked by transplantation of CB2,/, bone marrow into CB2+/+ mice, whereas CB2,/, mice transplanted with bone marrow from CB2+/+ mice did not display an increased sensitivity to bleomycin-induced fibrosis, indicating that leukocyte expression of CB2 critically influences experimental fibrosis. Conclusion Our findings indicate that CB2 limits leukocyte infiltration and tissue fibrosis in experimental dermal fibrosis. Since selective CB2 agonists are available and well tolerated, CB2 might be an interesting molecular target for the treatment of early inflammatory stages of systemic sclerosis. [source] A murine model of mixed connective tissue disease induced with U1 small nuclear RNP autoantigenARTHRITIS & RHEUMATISM, Issue 2 2006Eric L. Greidinger Objective To test whether immunizing mice with autoantigens closely linked to mixed connective tissue disease (MCTD) could induce an MCTD-like clinical syndrome distinguishable from systemic lupus erythematosus (SLE). Methods Transgenic and knockout C57BL/6-derived mice were immunized subcutaneously at age 8,12 weeks with U1,70-kd small nuclear RNP (70K) fusion protein along with either Freund's complete adjuvant (CFA) or U1 RNA. After 2 months, mice were killed and analyzed histologically and serologically. Results Immunization of C57BL/6-derived mice transgenic for human HLA,DR4 with 70K and either CFA or U1 RNA led to anti-70K antibodies in 62% of mice (21 of 34), and diversified anti-RNP immune responses. MCTD-like lung disease also developed in 50% of immunized mice (17 of 34), and anti-70K antibodies were strongly correlated with lung disease. CFA and U1 RNA were comparably able to induce this syndrome. Mice deficient in Toll-like receptor 3 (TLR-3) also developed this same syndrome when immunized with 70K and CFA. However, TLR-3,/, mice failed to develop MCTD-like lung disease when treated with 70K and U1 RNA. Rather, TLR-3,/, mice immunized with 70K and U1 RNA developed an autoimmune syndrome characterized by glomerulonephritis typical of SLE. Conclusion Exposure to 70K in an appropriate context is sufficient to induce autoimmunity and target organ injury consistent with MCTD. This system represents a new model of autoimmune interstitial lung disease, and establishes a closer link between anti-70K immunity and MCTD-like lung disease. Of note, changes in innate immune signaling can cause the same trigger to lead to the development of SLE-like nephritis rather than MCTD-like lung disease. [source] Neural and orofacial defects in Folbp1 knockout mice ,BIRTH DEFECTS RESEARCH, Issue 4 2003Louisa S. Tang Abstract BACKGROUND Folic acid is essential for the development of the nervous system and other associated structures. Mice deficient in the folic acid-binding protein one (Folbp1) gene display multiple developmental abnormalities, including neural and craniofacial defects. To better understand potential interactions between Folbp1 gene and selected genes involved in neural and craniofacial morphogenesis, we evaluated the expression patterns of a panel of crucial differentiation markers (Pax-3, En-2, Hox-a1, Shh, Bmp-4, Wnt-1, and Pax-1). METHODS Folbp1 mice were supplemented with low dosages of folinic acid to rescue nullizygotes from dying in utero before gestational day 10. The gene marker analyses were carried out by in situ hybridization. RESULTS In nullizygote embryos with open cranial neural tube defects, the downregulation of Pax-3 and En-2 in the impaired midbrain, along with an observed upregulation of the ventralizing marker Shh in the expanded floor plate, suggested an important regulatory interaction among these three genes. Moreover, the nullizygotes also exhibit craniofacial abnormalities, such as cleft lip and palate. Pax-3 signals in the impaired medial nasal primordia were significantly increased, whereas Pax-1 showed no expression in the undeveloped lateral nasal processes. Although Shh was downregulated, Bmp-4 was strongly expressed in the medial and lateral nasal processes, highlighting the antagonistic activities of these molecules. CONCLUSIONS Impairment of Folbp1 gene function adversely impacts the expression of several critical signaling molecules. Mis-expression of these molecules, perhaps mediated by Shh, may potentially contribute to the observed failure of neural tube closure and the development of craniofacial defects in the mutant mice. Birth Defects Research (Part A) 67:209,218, 2003. © 2003 Wiley-Liss, Inc. [source] Multiple MyD88-dependent responses contribute to pulmonary clearance of Legionella pneumophilaCELLULAR MICROBIOLOGY, Issue 1 2009Kristina A. Archer Summary MyD88-dependent signalling is important for secretion of early inflammatory cytokines and host protection in response to Legionella pneumophila infection. Although toll-like receptor (TLR)2 contributes to MyD88-dependent clearance of L. pneumophila, TLR-independent functions of MyD88 could also be important. To determine why MyD88 is critical for host protection to L. pneumophila, the contribution of multiple TLRs and IL-18 receptor (IL-18R)-dependent interferon-gamma (IFN-,) production in a mouse was examined. Mice deficient for TLR5 or TLR9, or deficient for TLR2 along with either TLR5 or TLR9, were competent for controlling bacterial replication and had no apparent defects in cytokine production compared with control mice. MyD88-dependent production of IFN-, in the lung was mediated primarily by natural killer cells and required IL-18R signalling. Reducing IFN-, levels did not greatly affect the kinetics of L. pneumophila replication or clearance in infected mice. Additionally, IFN-,-deficient mice did not have a susceptibility phenotype as severe as the MyD88-deficient mice and were able to control a pulmonary infection by L. pneumophila. Thus, MyD88-dependent innate immune responses induced by L. pneumophila involve both TLR-dependent responses and IL-18R-dependent production of IFN-, by natural killer cells, and these MyD88-dependent pathways can function independently to provide host protection against an intracellular pathogen. [source] Caspase-1/interleukin-1beta signaling in diabetic retinopathyACTA OPHTHALMOLOGICA, Issue 2008S MOHR Purpose The pro-inflammatory cytokine, interleukin-1, (IL-1,), is known to induce vascular dysfunction and cell death. Previously, we have shown that caspase-1 activity is increased in retinas of diabetic and galactosemic mice, and diabetic patients. Therefore, we investigated the role of IL-1, and caspase-1 (the enzyme that produces it) in diabetes-induced degeneration of retinal capillaries. Methods First, we determined the effect of agents known to inhibit caspase-1 (minocycline and tetracycline) on IL-1, production and retinal capillary degeneration in diabetic and galactose-fed mice. Diabetic and galactose-fed mice were injected intraperitoneally with minocycline or tetracycline (5mg/kg). Second, we examined the effect of genetic deletion of the IL-1, receptor on diabetes-induced caspase activities and retinal capillary degeneration using IL-1 receptor knock-out mice. Results At 2 months of diabetes, minocycline inhibited hyperglycemia-induced caspase-1 activity and IL-1, production in the retina. Long-term administration of minocycline prevented retinal capillary degeneration in diabetic (6 months) and galactose-fed (13 months) mice. Tetracycline inhibited hyperglycemia-induced caspase-1 activity in vitro, but not in vivo. Mice deficient in the IL-1, receptor were protected from diabetes-induced caspase activation and retinal pathology at 7 months of diabetes. Conclusion These results indicate that the caspase-1/IL-1, signaling pathway plays an important role in diabetes-induced retinal pathology and its inhibition might represent a new strategy to inhibit capillary degeneration in diabetic retinopathy. [source] Investigation of Protective Reactions Against Cadmium Toxicity in the Cells Established from a Transgenic Mouse Deficient in the Metallothionein GenesJOURNAL OF OBSTETRICS AND GYNAECOLOGY RESEARCH (ELECTRONIC), Issue 2 2003Tetsuya Abe Objective:, To characterize a fibroblast cell strain which we established from an metallothionein (MT) knock-out (KO) mouse and to determine whether expression of the Hsp genes induced by cadmium is related to expression of the MT-I and -II genes. Methods:, We established a fibroblast cell strain (named "MT-KO2") derived from the peritoneum of an MT-KO mouse which is deficient in the MT-I and -II genes. We determined an expression of MT-I, Hsp32 and Grp 78 genes by Northern blot analysis. Results:, The mRNA level of MT-I, an isoform of the MT gene products, was induced dose-dependently in responce to increasing concentrations of CdCl2 (5,25 µM) in a fibroblast cell strain derived from the peritoneum of an MT wild type mouse (named "MT-W3"). But it was not induced in MT-KO2 cells after the same treatment. There was no significant difference between MT-KO2 and MT-W3 cells in a concentration of intracellular glutathione (reduced form) under normal conditions. MT-KO2 cells were not more sensitive to cytotoxicity of CdCl2 than in MT-W3 cells. Expression of the Hsp32 gene was more extensively enhanced in MT-KO2 cells than in MT-W3 cells after treatment with 5,10 µM CdCl2 for 5 hours. Furthermore, the cellular concentration of reduced glatathione (GSH) was also more increased in MT-KO2 cells than in MT-W3 cells after treatment with 50 µM CdCl2 for 3 hours. Conclusions:, Expression of the Hsp32 gene tends to be increased in MT-KO2 cells in response to cadmium exposure. The expression of the Hsp32 gene and increase in the cellular concentration of GSH may be augmented to compensate for the impaired expression of the MT genes in MT-KO2 cells. [source] Thyroid hormone receptor , can control action potential duration in mouse ventricular myocytes through the KCNE1 ion channel subunitACTA PHYSIOLOGICA, Issue 2 2010A. Mansén Abstract Aims:, The reduced heart rate and prolonged QTend duration in mice deficient in thyroid hormone receptor (TR) ,1 may involve aberrant expression of the K+ channel ,-subunit KCNQ1 and its regulatory ,-subunit KCNE1. Here we focus on KCNE1 and study whether increased KCNE1 expression can explain changes in cardiac function observed in TR,1-deficient mice. Methods:, TR-deficient, KCNE1-overexpressing and their respective wildtype (wt) mice were used. mRNA and protein expression were assessed with Northern and Western blot respectively. Telemetry was used to record electrocardiogram and temperature in freely moving mice. Patch-clamp was used to measure action potentials (APs) in isolated cardiomyocytes and ion currents in Chinese hamster ovary (CHO) cells. Results:, KCNE1 was four to 10-fold overexpressed in mice deficient in TR,1. Overexpression of KCNE1 with a heart-specific promoter in transgenic mice resulted in a cardiac phenotype similar to that in TR,1-deficient mice, including a lower heart rate and prolonged QTend time. Cardiomyocytes from KCNE1-overexpressing mice displayed increased AP duration. CHO cells transfected with expression plasmids for KCNQ1 and KCNE1 showed an outward rectifying current that was maximal at equimolar plasmids for KCNQ1-KCNE1 and decreased at higher KCNE1 levels. Conclusion:, The bradycardia and prolonged QTend time in hypothyroid states can be explained by altered K+ channel function due to decreased TR,1-dependent repression of KCNE1 expression. [source] Neural tube defects and impaired neural progenitor cell proliferation in G,1 -deficient miceDEVELOPMENTAL DYNAMICS, Issue 4 2010Hiroaki Okae Abstract Heterotrimeric G proteins are well known for their roles in signal transduction downstream of G protein,coupled receptors (GPCRs), and both G, subunits and tightly associated G,, subunits regulate downstream effector molecules. Compared to G, subunits, the physiological roles of individual G, and G, subunits are poorly understood. In this study, we generated mice deficient in the G,1 gene and found that G,1 is required for neural tube closure, neural progenitor cell proliferation, and neonatal development. About 40% G,1,/, embryos developed neural tube defects (NTDs) and abnormal actin organization was observed in the basal side of neuroepithelium. In addition, G,1,/, embryos without NTDs showed microencephaly and died within 2 days after birth. GPCR agonist-induced ERK phosphorylation, cell proliferation, and cell spreading, which were all found to be regulated by G,i and G,, signaling, were abnormal in G,1,/, neural progenitor cells. These data indicate that G,1 is required for normal embryonic neurogenesis. Developmental Dynamics 239:1089,1101, 2010. © 2010 Wiley-Liss, Inc. [source] Gli3 -deficient mice exhibit cleft palate associated with abnormal tongue developmentDEVELOPMENTAL DYNAMICS, Issue 10 2008Xi Huang Abstract Palatogenesis depends on appropriate growth, elevation, and fusion of the palatal shelves and aberration in these processes can lead to palatal clefting. We observed a high incidence of palate clefting in mice deficient in Gli3, known for its role as a repressor in the absence of Shh signaling. In contrast with several current mouse models of cleft palate, Meckel's cartilage extension, cranial neural crest migration, palatal shelf proliferation, apoptosis, and key signaling components mediated by Shh, Bmp, Fgf, and Tgf,, appeared unaffected in Gli3,/, mice. Palatal clefting in Gli3,/, mice was consistently associated with tongue abnormalities such as failure to flatten and improper positioning, implicating a critical role of Gli3 and normal tongue morphogenesis for timely palatal shelf elevation and joining. Furthermore, Gli3,/, palatal shelves grown in roller cultures without tongue can fuse suggesting that the abnormal tongue is likely an impediment for palatal shelf joining in Gli3,/, mutants. Developmental Dynamics 237:3079,3087, 2008. © 2008 Wiley-Liss, Inc. [source] PDGFR-, signaling is critical for tooth cusp and palate morphogenesisDEVELOPMENTAL DYNAMICS, Issue 1 2005Xun Xu Abstract Platelet-derived growth factor receptor alpha (PDGFR-,) and PDGF ligands are key regulators for embryonic development. Although Pdgfr, is spatially expressed in the cranial neural crest (CNC)-derived odontogenic mesenchyme, mice deficient for Pdgfr, are embryonic lethal, making it impossible to investigate the functional significance of PDGF signaling in regulating the fate of CNC cells during tooth morphogenesis. Taking advantage of the kidney capsule assay, we investigated the biological function of PDGF signaling in regulating tooth morphogenesis. Pdgfr, and Pdgfa are specifically and consistently expressed in the CNC-derived odontogenic mesenchyme and the dental epithelium, respectively, throughout all stages of tooth development, suggesting a paracrine function of PDGF signaling in regulating tooth morphogenesis. Highly concentrated expression patterns of Pdgfr, and Pdgfa are associated with the developing dental cusp, suggesting possible functional importance of PDGF signaling in regulating cusp formation. Loss of the Pdgfr, gene does not affect proper odontoblasts proliferation and differentiation in the CNC-derived odontogenic mesenchyme but perturbs the formation of extracellular matrix and the organization of odontoblast cells at the forming cusp area, resulting in dental cusp growth defect. Pdgfr,,/, mice have complete cleft palate. We show that the cleft palate in Pdgfr, mutant mice results from an extracellular matrix defect within the CNC-derived palatal mesenchyme. The midline epithelium of the mutant palatal shelf remains functionally competent to mediate palatal fusion once the palatal shelves are placed in close contact in vitro. Collectively, our data suggests that PDGFR, and PDGFA are critical regulators for the continued epithelial,mesenchymal interaction during tooth and palate morphogenesis. Disruption of PDGFR, signaling disturbs the growth of dental cusp and interferes with the critical extension of palatal shelf during craniofacial development. Developmental Dynamics 232:75,84, 2005. © 2004 Wiley-Liss, Inc. [source] Splice-isoform specific immunolocalization of neuronal nitric oxide synthase in mouse and rat brain reveals that the PDZ-complex-building nNOS, ,-finger is largely exposed to antibodiesDEVELOPMENTAL NEUROBIOLOGY, Issue 4 2007Kristina Langnaese Abstract Knock out mice deficient for the splice-isoform ,, of neuronal nitric oxide synthase (nNOS,,) display residual nitric oxide synthase activity and immunosignal. To attribute this signal to the two minor neuronal nitric oxide synthase splice variants, ,, and ,,, we generated isoform-specific anti-peptide antibodies against the nNOS,, specific ,,-finger motif involved in PDZ domain scaffolding and the nNOS,, specific N-terminus. The nNOS,, ,,-finger-specific antibody clearly recognized the 160-kDa band of recombinant nNOS,, on Western blots. Using immunocytochemistry, this antibody displayed, in rats and wild-type mice, a labeling pattern similar to but not identical with that obtained using a commercial pan-nNOS antibody. This similarity indicates that the majority of immunocytochemically detectable nNOS is not likely to be complexed with PDZ-domain proteins via the ,,-finger motif. This conclusion was confirmed by the inhibition of PSD-95/nNOS interaction by the nNOS,, ,,-finger antibody in pull-down assays. By contrast, nNOS,, ,,-finger labeling was clearly reduced in hippocampal and cortical neuropil areas enriched in NMDA receptor complex containing spine synapses. In nNOS,, knock out mice, nNOS,, was not detectable, whereas the pan-nNOS antibody showed a distinct labeling of cell bodies throughout the brain, most likely reflecting ,,/,,-isoforms in these cells. The nNOS,, antibody clearly detected bacterial expressed nNOS,, fusion protein and nNOS,, in overexpressing HEK cells by Western blotting. Immunocytochemically, individual cell bodies in striatum, cerebral cortex, and in some brain stem nuclei were labeled in knock out but not in wild-type mice, indicating an upregulation of nNOS,, in nNOS,, deficient animals. © 2007 Wiley Periodicals, Inc. Develop Neurobiol, 2007 [source] Endothelially Derived Nitric Oxide Affects the Severity of Early Acetaminophen-induced Hepatic Injury in MiceACADEMIC EMERGENCY MEDICINE, Issue 5 2006Steven D. Salhanick MD Abstract Objectives: The precise mechanism of hepatocellular toxicity following acetaminophen (APAP) poisoning remains unclear. Nitric oxide is implicated in APAP toxicity as an inflammatory signaling molecule and as a precursor to the free radical peroxynitrate. The effects of inducible nitric oxide synthase (iNOS)-derived NO in APAP toxicity are known; however, the role of endothelial nitric oxide synthase (eNOS)-derived NO is unknown. The authors sought to evaluate the effect of eNOS-derived NO during APAP toxicity. Methods: C57BL6/J mice deficient in eNOS (eNOS KO) or iNOS (iNOS KO) and wild-type mice (WT) were treated with 300 mg/kg APAP. Alanine aminotransferase levels and plasma nitrate and nitrite levels were measured. Hypoxia inducible factor (HIF)-1, and Glucose Transporter 1 (Glut-1) levels were determined by Western blot. Results: Alanine aminotransferase levels were significantly elevated in all treated animals. Alanine aminotransferase levels were significantly lower in eNOS KO and iNOS KO than in treated WT animals. Plasma nitrate/nitrite levels were significantly higher in WT animals than in iNOS KO and eNOS KO animals. HIF-1, expression was increased in WT mice and decreased in iNOS KO mice. Glut-1 is a downstream, indirect marker of HIF function. Glut-1 expression was increased in WT and eNOS KO mice. Conclusions: Deficiency of either iNOS or eNOS results in decreased NO production and is associated with reduced hepatocellular injury following APAP poisoning. HIF-1, and Glut-1 levels are increased following APAP poisoning, implying that HIF-1, is functional during the pathogenic response to APAP poisoning. [source] Remodeling of extracellular matrix and epileptogenesisEPILEPSIA, Issue 2010Alexander Dityatev Summary Extracellular matrix (ECM) in the brain is composed of molecules synthesized and secreted by neurons and glial cells, which form stable aggregates of diverse composition in the extracellular space. In the mature brain, ECM undergoes a slow turnover and restrains structural plasticity while supporting multiple physiologic processes, including perisomatic ,-aminobutyric acid (GABA)ergic inhibition, synaptic plasticity, and homeostatic regulations. Seizures lead to striking remodeling of ECM, which may be essentially engaged in different aspects of epileptogenesis. This view is supported by human genetic studies linking ECM molecules and epilepsy, by data showing altered epileptogenesis in mice deficient in ECM molecules, and by evidence that ECM may shape seizure-induced sprouting of mossy fibers, granule cell dispersion, and astrogliosis. Therefore, restraining seizure-induced remodeling of ECM or suppressing the signaling triggered by the remodeled ECM might provide effective therapeutic strategies to antagonize the progression of epileptogenesis. [source] Retarded kindling progression in mice deficient in the extracellular matrix glycoprotein tenascin-REPILEPSIA, Issue 4 2009Katrin Hoffmann Summary Purpose:, We investigated the role of the extracellular matrix glycoprotein tenascin-R (TNR) in formation of a hyperexcitable network in the kindling model of epilepsy. The idea that TNR may be important for this process was suggested by previous studies showing that deficiency in TNR leads to abnormalities in synaptic plasticity, perisomatic GABAergic inhibition and more astrocytes in the hippocampus of adult mice. Methods:, Constitutively TNR deficient (TNR,/,) mice and their wild-type littermates received repeated electrical stimulation in the amygdala over several days until they developed fully kindled generalized seizures at which time their brains were studied immunohistochemically. Results:, In TNR,/, mice, kindling progression was retarded compared with wild-type littermate controls. Morphological analysis of the mice used for the kindling studies revealed that, independently of genotype, numbers of parvalbumin-positive interneurons in the dentate gyrus correlated positively with afterdischarge threshold alterations in kindled mice. The kindling-induced increase in the number of S100 expressing astrocytes in the dentate gyrus was enhanced by TNR deficiency and correlated negatively with the kindling rate. Discussion:, Our data support the view that TNR promotes formation of a hyperexcitable network during kindling and suggest that an increase in S100-expressing astrocytes may contribute to retarded epileptogenesis in TNR,/, mice. [source] | |||||||||||||||||||||||||||||||