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Mice Transgenic (mouse + transgenic)
Selected AbstractsMice transgenic for exon 1 of the Huntington's disease gene display reduced striatal sensitivity to neurotoxicity induced by dopamine and 6-hydroxydopamineEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 9 2001Åsa Petersén Abstract Huntington's disease is an autosomal dominant hereditary neurodegenerative disorder characterized by severe striatal cell loss. Dopamine (DA) has been suggested to play a role in the pathogenesis of the disease. We have previously reported that transgenic mice expressing exon 1 of the human Huntington gene (R6 lines) are resistant to quinolinic acid-induced striatal toxicity. In this study we show that with increasing age, R6/1 and R6/2 mice develop partial resistance to DA- and 6-hydroxydopamine-mediated toxicity in the striatum. Using electron microscopy, we found that the resistance is localized to the cell bodies and not to the neuropil. The reduction of dopamine and cAMP regulated phosphoprotein of a molecular weight of 32 kDa (DARPP-32) in R6/2 mice does not provide the resistance, as DA-induced striatal lesions are not reduced in size in DARPP-32 knockout mice. Neither DA receptor antagonists nor a N -methyl- d -aspartate (NMDA) receptor blocker reduce the size of DA-induced striatal lesions, suggesting that DA toxicity is not dependent upon DA- or NMDA receptor-mediated pathways. Moreover, superoxide dismutase-1 overexpression, monoamine oxidase inhibition and the treatment with the free radical scavenging spin-trap agent phenyl-butyl-tert-nitrone (PBN) also did not block DA toxicity. Levels of the antioxidant molecules, glutathione and ascorbate were not increased in R6/1 mice. Because damage to striatal neurons following intrastriatal injection of 6-hydroxydopamine was also reduced in R6 mice, a yet-to-be identified antioxidant mechanism may provide neuroprotection in these animals. We conclude that striatal neurons of R6 mice develop resistance to DA-induced toxicity with age. [source] The transcription factor Fra-2 regulates the production of extracellular matrix in systemic sclerosisARTHRITIS & RHEUMATISM, Issue 1 2010Nicole Reich Objective Fra-2 belongs to the activator protein 1 family of transcription factors. Mice transgenic for Fra-2 develop a systemic fibrotic disease with vascular manifestations similar to those of systemic sclerosis (SSc). The aim of the present study was to investigate whether Fra-2 plays a role in the pathogenesis of SSc and to identify the molecular mechanisms by which Fra-2 induces fibrosis. Methods Dermal thickness and the number of myofibroblasts were determined in skin sections from Fra-2,transgenic and wild-type mice. The expression of Fra-2 in SSc patients and in animal models of SSc was analyzed by real-time polymerase chain reaction and immunohistochemistry. Fra-2, transforming growth factor , (TGF,), and ERK signaling in SSc fibroblasts were inhibited using small interfering RNA, neutralizing antibodies, and small-molecule inhibitors. Results Fra-2,transgenic mice developed a skin fibrosis with increases in dermal thickness and increased myofibroblast differentiation starting at age 12 weeks. The expression of Fra-2 was up-regulated in SSc patients and in different mouse models of SSc. Stimulation with TGF, and platelet-derived growth factor (PDGF) significantly increased the expression of Fra-2 in SSc fibroblasts and induced DNA binding of Fra-2 in an ERK-dependent manner. Knockdown of Fra-2 potently reduced the stimulatory effects of TGF, and PDGF and decreased the release of collagen from SSc fibroblasts. Conclusion We demonstrate that Fra-2 is overexpressed in SSc and acts as a novel downstream mediator of the profibrotic effects of TGF, and PDGF. Since transgenic overexpression of Fra-2 causes not only fibrosis but also vascular disease, Fra-2 might be an interesting novel candidate for molecular-targeted therapies for SSc. [source] Bone Morphogenetic Protein 2 Induces Cyclo-oxygenase 2 in Osteoblasts via a Cbfa1 Binding Site: Role in Effects of Bone Morphogenetic Protein 2 In Vitro and In VivoJOURNAL OF BONE AND MINERAL RESEARCH, Issue 10 2005Daichi Chikazu Abstract We tested the hypothesis that induction of cyclo-oxygenase (COX) 2 mediates some effects of bone morphogenetic protein (BMP) 2 on bone. BMP-2 induced COX-2 mRNA and prostaglandin (PG) production in cultured osteoblasts. BMP-2 increased luciferase activity in calvarial osteoblasts from mice transgenic for a COX-2 promoter-luciferase reporter construct (Pluc) and in MC3T3-E1 cells transfected with Pluc. Deletion analysis identified the -300/-213-bp region of the COX-2 promoter as necessary for BMP-2 stimulation of luciferase activity. Mutation of core-binding factor activity 1 (muCbfa1) consensus sequence (5,-AACCACA-3,) at -267/-261 bp decreased BMP-2 stimulation of luciferase activity by 82%. Binding of nuclear proteins to an oligonucleotide spanning the Cbfa1 site was inhibited or supershifted by specific antibodies to Cbfa1. In cultured osteoblasts from calvariae of COX-2 knockout (-/-) and wild-type (+/+) mice, the absence of COX-2 expression reduced the BMP-2 stimulation of both ALP activity and osteocalcin mRNA expression. In cultured marrow cells flushed from long bones, BMP-2 induced osteoclast formation in cells from COX-2+/+ mice but not in cells from COX-2,/, mice. In vivo, BMP-2 (10 ,g/pellet) induced mineralization in pellets of lyophilized collagen implanted in the flanks of mice. Mineralization of pellets, measured by microcomputed tomography (,CT), was decreased by 78% in COX-2,/, mice compared with COX-2+/+ mice. We conclude that BMP-2 transcriptionally induces COX-2 in osteoblasts via a Cbfa1 binding site and that the BMP-2 induction of COX-2 can contribute to effects of BMP-2 on osteoblastic differentiation and osteoclast formation in vitro and to the BMP-2 stimulation of ectopic bone formation in vivo. [source] Fluid Flow Induction of Cyclo-Oxygenase 2 Gene Expression in Osteoblasts Is Dependent on an Extracellular Signal-Regulated Kinase Signaling Pathway,,JOURNAL OF BONE AND MINERAL RESEARCH, Issue 2 2002Sunil Wadhwa Abstract Mechanical loading of bone may be transmitted to osteocytes and osteoblasts via shear stresses at cell surfaces generated by the flow of interstitial fluid. The stimulated production of prostaglandins, which mediates some effects of mechanical loading on bone, is dependent on inducible cyclo-oxygenase 2 (COX-2) in bone cells. We examined the fluid shear stress (FSS) induction of COX-2 gene expression in immortalized MC3T3-E1 osteoblastic cells stably transfected with ,371/+70 base pairs (bp) of the COX-2 5,-flanking DNA (Pluc371) and in primary osteoblasts (POBs) from calvaria of mice transgenic for Pluc371. Cells were plated on collagen-coated glass slides and subjected to steady laminar FSS in a parallel plate flow chamber. FSS, from 0.14 to10 dynes/cm2, induced COX-2 messenger RNA (mRNA) and protein. FSS (10 dynes/cm2) induced COX-2 mRNA within 30 minutes, with peak effects at 4 h in MC3T3-E1 cells and at ,8 h in POBs. An inhibitor of new protein synthesis puromycin blocked the peak induction of COX-2 mRNA by FSS. COX-2 promoter activity, measured as luciferase activity, correlated with COX-2 mRNA expression in both MC3T3-E1 and POB cells. FSS induced phosphorylation of extracellular signal-regulated kinase (ERK) in MC3T3-E1 cells, with peak effects at 5 minutes. Inhibiting ERK phosphorylation with the specific inhibitor PD98059 inhibited FSS induction of COX-2 mRNA by 55-70% and FSS stimulation of luciferase activity by ,80% in both MC3T3-E1 and POB cells. We conclude that FSS transcriptionally induces COX-2 gene expression in osteoblasts, that the maximum induction requires new protein synthesis, and that induction occurs largely via an ERK signaling pathway. [source] Immunoreactivity of the phosphorylated axonal neurofilament H subunit (pNF-H) in blood of ALS model rodents and ALS patients: evaluation of blood pNF-H as a potential ALS biomarkerJOURNAL OF NEUROCHEMISTRY, Issue 5 2009Kevin Boylan Abstract Levels of neurofilament subunits, potential biomarkers of motor axon breakdown, are increased in amyotrophic lateral sclerosis (ALS) patient's CSF but data on blood are not available. We measured blood levels of the phosphorylated axonal form of neurofilament H (pNF-H) by ELISA in transgenic rodent models of superoxide dismutase 1 (SOD1) ALS, and in 20 ALS patients and 20 similar aged controls monthly for 4 months. All symptomatic rodent ALS models showed robust levels of blood pNF-H, while control rodents or mice transgenic for unmutated SOD1 showed no detectable blood pNF-H. Average pNF-H levels in the G93A SOD1 mouse progressively increased from day 74 through death (day ,130). Median blood pNF-H level in ALS patients was 2.8-fold higher than controls (p < 0.001). Median ALSFRS-R declined a median of 0.8 pt/month (p < 0.001); higher baseline pNF-H level appeared to be associated with faster ALSFRS-R decline over 4 months (p = 0.087). The median rate of decline in ALSFRS-R was 1.9 pt/month in patients with baseline pNF-H levels above the median pNF-H value of 0.53 ng/mL; ALSFRS-R declined at a median of 0.6 pt/month in patients below this level. The pNF-H levels were relatively stable month to month in individual patients, raising questions regarding the molecular pathogenesis of ALS. Baseline control human pNF-H levels were higher in men than women and increased minimally over time. These data suggest that blood pNF-H can be used to monitor axonal degeneration in ALS model rodents and support further study of this protein as a potential biomarker of disease prognosis in ALS patients. [source] Disruption of neurogenesis by amyloid ,-peptide, and perturbed neural progenitor cell homeostasis, in models of Alzheimer's diseaseJOURNAL OF NEUROCHEMISTRY, Issue 6 2002Norman J. Haughey Abstract Neurogenesis occurs in the adult mammalian brain and may play roles in learning and memory processes and recovery from injury, suggesting that abnormalities in neural progenitor cells (NPC) might contribute to the pathogenesis of disorders of learning and memory in humans. The objectives of this study were to determine whether NPC proliferation, survival and neuronal differentiation are impaired in a transgenic mouse model of Alzheimer's disease (AD), and to determine the effects of the pathogenic form of amyloid ,-peptide (A,) on the survival and neuronal differentiation of cultured NPC. The proliferation and survival of NPC in the dentate gyrus of the hippocampus was reduced in mice transgenic for a mutated form of amyloid precursor protein that causes early onset familial AD. A, impaired the proliferation and neuronal differentiation of cultured human and rodent NPC, and promoted apoptosis of neuron-restricted NPC by a mechanism involving dysregulation of cellular calcium homeostasis and the activation of calpains and caspases. Adverse effects of A, on NPC may contribute to the depletion of neurons and cognitive impairment in AD. [source] Fusion protein consisting of the first immunoglobulin-like domain of porcine nectin-1 and Fc portion of human IgG1 provides a marked resistance against pseudorabies virus infection to transgenic miceMICROBIOLOGY AND IMMUNOLOGY, Issue 1 2009Yukiko Tomioka ABSTRACT Nectin-1 is a Ca2+ -independent Ig-like cell,cell adhesion molecule and an alphaherpesvirus receptor that binds to virion glycoprotein D by the first Ig-like domain. We have investigated the antiviral potentials of soluble forms of porcine nectin-1 to PRV infection by generating transgenic mice expressing different types of fusion protein. Previously, we reported that mice transgenic for a chimera that carried the entire ectodomain of porcine nectin-1 fused to the Fc portion of porcine IgG1 were more resistant than those transgenic for a chimera that carried the first Ig-like domain fused to the Fc portion. Recently, we generated transgenic mice expressing a fusion protein made of the first Ig-like domain fused to the Fc portion of human IgG1, and reported that they showed a microphthalmia. Here, two transgenic mouse lines expressing the fusion protein were challenged with PRV for comparing their resistances with those of transgenic mice expressing different types of fusion protein. Surprisingly, both transgenic mouse lines showed a high resistance to the viral infection, especially via the i.n. route. Significant resistance of the embryonic fibroblasts was also observed. Altogether, these findings indicated that the fusion protein consisting of the first Ig-like domain fused to the human Fc portion provided a marked resistance against PRV infection to the transgenic mice. [source] Prevention of red cell alloimmunization by CD25 regulatory T cells in mouse modelsAMERICAN JOURNAL OF HEMATOLOGY, Issue 8 2007Jin Yu Transfusion therapy is currently an effective therapeutic intervention in a number of diseases, including sickle cell disease. However, its use is complicated by a high incidence of red blood cell (RBC) alloimmunization in the transfusion recipients. The identification of T regulatory cells (Tregs) among the CD4+ CD25+ T cell subset as key regulators of peripheral tolerance in mice as well as humans has opened an exciting era in the prevention and treatment of autoimmune disease and for improving organ transplantation. However, their potential in inducing transfusion tolerance remains to be explored. We used red cells from mice transgenic for human glycophorin A blood group antigen as donor cells and transfused wild-type mice to induce alloantibodies, as an experimental system to study RBC alloimmunization. We found that depletion with anti-CD25 enhanced the alloantibody production, indicating that CD25 Tregs play an important role in regulation of alloantibody responses. More importantly, adoptive transfer of purified population of CD4+CD25+ but not CD4+CD25, cells from naïve mice prevented the induction of IgG and IgM alloantibody production in transfusion recipients, with a concomitant reduction in activated splenic B cells and macrophages. Similarly, adoptive transfer of purified populations of CD4+CD25+ cells from naïve mice into naïve syngeneic recipients inhibited the anti-Ig response to rat RBCs in the recipients but transfer of control CD4+CD25, cells did not. Altogether, our results demonstrate that Tregs participate in the control of transfusion-associated RBC alloantibody responses, opening up the possibility that Treg immunotherapy may be exploited for suppressing transfusion immunization events. Am. J. Hematol., 2007. © 2007 Wiley-Liss, Inc. [source] Reference maps of mouse serum acute-phase proteins: Changes with LPS-induced inflammation and apolipoprotein,A-I and A-II transgenesPROTEINS: STRUCTURE, FUNCTION AND BIOINFORMATICS, Issue 16 2005Robin Wait Abstract We present reference maps of the mouse serum proteome (run under reducing and non-reducing conditions), from control animals, from mice injected with lipopolysaccharide (LPS) to induce systemic inflammation, and from mice transgenic for human apolipoproteins,A-I and A-II. Seventy-seven spots/spot chains from the reducing gels were identified by HPLC MS/MS, representing 28,distinct proteins, including a species-specific protease inhibitor, contrapsin, and high levels of carboxylesterase. The concentrations of acute-phase reactants were monitored for 96,h after LPS challenge. The greatest changes (four-fold 48,h after LPS administration) were observed for haptoglobin and hemopexin. Orosomucoid/,1 -acid glycoprotein and apolipoprotein,A-I increased steadily, to 50,60% above baseline at 96,h from stimulation. In mice transgenic for human apolipoprotein,A-I the levels of expression of orosomucoid/,1 -acid glycoprotein, ,1 -macroglobulin, esterase, kininogen and contrapsin were altered compared to knockout mice lacking apolipoprotein,A-I. In contrast, except for the presence of apolipoprotein,A-II, no statistically significant difference was observed in mice transgenic for human apolipoprotein,A-II. [source] Epidermal Langerhans Cells Promote Skin Allograft Rejection in Mice With NF-,B-impaired T CellsAMERICAN JOURNAL OF TRANSPLANTATION, Issue 1 2008L. L. Molinero T cells play a major role in the acute rejection of transplanted organs. Using mice transgenic for a T-cell-restricted NF-,B super-repressor (I,B,,N-Tg mice), we have previously shown that T-cell-NF-,B is essential for the acute rejection of cardiac but not skin allografts. In this study, we investigated the mechanism by which skin grafts activate I,B,,N-Tg T cells. Rejection was not due to residual T-cell-NF-,B activity as mice with p50/p52,/, T cells successfully rejected skin grafts. Rather, skin but not cardiac allografts effectively induced proliferation of graft-specific I,B,,N-Tg T cells. Rejection of skin grafts by I,B,,N-Tg mice was in part dependent on the presence of donor Langerhans cells (LC), a type of epidermal dendritic cells (DC), as lack of LC in donor skin grafts resulted in prolongation of skin allograft survival and injection of LC at the time of cardiac transplantation was sufficient to promote cardiac allograft rejection by I,B,,N-Tg mice. Our results suggest that LC allow NF-,B-impaired T cells to reach an activation threshold sufficient for transplant rejection. The combined blockade of T-cell-NF-,B with that of alternative pathways allowing activation of NF-,B-impaired T cells may be an effective strategy for tolerance induction to highly immunogenic organs. [source] Slowed progression in models of huntington disease by adipose stem cell transplantation,ANNALS OF NEUROLOGY, Issue 5 2009Soon-Tae Lee MD Objective Adipose-derived stem cells (ASCs) are readily accessible and secrete multiple growth factors. Here, we show that ASC transplantation rescues the striatal pathology of Huntington disease (HD) models. Methods ASCs were isolated from human subcutaneous adipose tissue. In a quinolinic acid (QA)-induced rat model of striatal degeneration, human ASCs (1 million cells) were transplanted into the ipsilateral striatal border immediately after the QA injection. In 60-day-old R6/2 mice transgenic for HD, ASCs (0.5 million cells) were transplanted into each bilateral striata. In in vitro experiments, we treated mutant huntingtin gene-transfected cerebral neurons with ASC-conditioned media. Results In the QA model, human ASCs reduced apomorphine-induced rotation behavior, lesion volume, and striatal apoptosis. In R6/2 transgenic mice, transplantation of ASCs improved Rota-Rod performance and limb clasping, increased survival, attenuated the loss of striatal neurons, and reduced the huntingtin aggregates. ASC-transplanted R6/2 mice expressed elevated levels of peroxisome proliferator-activated receptor , coactivator-1, (PGC-1,) and reactive oxygen defense enzymes and showed activation of the Akt/cAMP-response element-binding proteins. ASC-conditioned media decreased the level of N-terminal fragments of mutant huntingtin and associated apoptosis, and increased PGC-1, expression. Interpretation Collectively, ASC transplantation slowed striatal degeneration and behavioral deterioration of HD models, possibly via secreted factors. Ann Neurol 2009;66:671,681 [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] Peptide-induced suppression of collagen-induced arthritis in HLA,DR1 transgenic miceARTHRITIS & RHEUMATISM, Issue 12 2002Linda K. Myers Objective To identify peptides capable of altering the immune response to type II collagen (CII) in the context of HLA,DR. Methods Immunizing mice transgenic for the human HLA,DRB1*0101 immune response gene with CII elicits an arthritis (collagen-induced arthritis [CIA]) that resembles rheumatoid arthritis. We have previously identified an immunodominant determinant of CII, CII (263,270), recognized by T cells in the context of DR1. To produce synthetic peptides with the potential of disrupting the DR1-restricted immune response, synthetic analog peptides were developed that contain site-directed substitutions in critical positions. These peptides were used to treat CIA in DR1 transgenic mice. Results An analog peptide, CII (256,276, N263, D266), that inhibited T cell responses in vitro, was identified. When DR1 mice were coimmunized with CII and CII (256,276, N263, D266), the incidence and severity of arthritis were greatly reduced, as was the antibody response to CII. Moreover, CII (256,276, N263, D266) was effective in down-regulating the immune responses to CII and arthritis, even when administered 2 weeks following immunization with CII. Spleen and lymph node cells from CII-immunized mice cultured with CII (256,276, N263, D266) in vitro produced increased amounts of interleukin-4 (IL-4) compared with cells cultured with the wild-type peptide, CII (256,276). Furthermore, CII (256,276, N263, D266) was incapable of preventing arthritis in DR1 IL-4,/, mice (genetically deficient in IL-4). Conclusion These data establish that CII (256,276, N263, D266) is a potent suppressor of the DR-mediated immune response to CII. Its effect is mediated, at least in part, by IL-4. These experiments represent the first description of an analog peptide of CII recognized by T cells in the context of a human major histocompatibility complex molecule that can suppress autoimmune arthritis. [source] | |||||||||||||