Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:2.1.1.148 (Thy1)
 1,210 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The expression of the two cytoskeletal linking proteins, moesin and radixin, was examined in experimental mesangial proliferative nephritis in rats (anti-Thy1 model). Moesin and radixin mRNA and protein are constitutively expressed in all cell types of normal rat glomeruli, except podocytes. In the anti-Thy1 model the expression of moesin and radixin was increased in infiltrating macrophages and in activated, alpha-smooth muscle actin-positive mesangial cells and was concentrated in the cellular extensions of mesangial cells in areas of glomerular remodelling. Studies using neutralizing antibodies demonstrated that the increase in moesin and radixin expression by mesangial cells is mediated by PDGF, but not bFGF. The increase in these cytoskeletal proteins appears to be regulated primarily (radixin) or partially (moesin) posttranscriptionally. The data suggest that PDGF mediated upregulation of the cytoskeletal proteins, moesin and radixin, is important for cell migration and other changes that accompany the coordinated restoration of glomerular architecture after injury.
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PMID:The cytoskeletal linking proteins, moesin and radixin, are upregulated by platelet-derived growth factor, but not basic fibroblast growth factor in experimental mesangial proliferative glomerulonephritis. 864 42

Inhibition of 3-hydro-3-methylglutaryl coenzyme A reductase inhibits the production of mevalonate and has been shown to suppress proliferation in many cell types. Therefore, 3-hydro-3-methylglutaryl coenzyme A reductase inhibitors may have a beneficial effect in glomerular disease, because glomerular cell proliferation is a central feature in the active glomerular injury. This study examines the effect of simvastatin on glomerular pathology in a rat mesangial proliferative glomerulonephritis (GN) induced by anti-thymocyte antibody (anti-Thy 1.1 GN). There was no difference in the degree of the antibody and complement-mediated initial injuries between simvastatin-treated and control GN rats. The most pronounced feature of simvastatin-treated GN was the suppression of the early glomerular cell proliferation. The proliferative activity was maximal at day 4 after disease induction (26.5+/-7.0 of proliferating cell nuclear antigen-positive cells/glomerulus); however, approximately 70% of proliferation was suppressed by simvastatin treatment. At day 4 after disease induction, simvastatin administration also decreased alpha-smooth muscle actin expression in the glomerulus, which is a marker for mesangial cell activation. Inhibition of monocyte/macrophage recruitment into glomeruli by simvastatin was also a prominent feature. There was a 30% decrease in the number of glomerular ED-1+ cells by simvastatin treatment at day 2 after disease induction. Furthermore, simvastatin remarkably suppressed subsequent mesangial matrix expansion and type IV collagen accumulation in glomeruli. We also found that the platelet-derived growth factor expression was reduced in simvastatin-treated nephritic rats, which might simply reflect the reduction in mesangial cell proliferation and mesangial cellularity. There was no significant difference in plasma cholesterol or triglyceride levels between simvastatin- and vehicle-treated nephritic rats at day 2 and day 4, which corresponded to the times when simvastatin treatment resulted in a reduction in mesangial cell proliferation. In conclusion, this is the first report to find that mesangial cell proliferation and matrix expansion have been blocked by simvastatin in vivo. The protective effect of simvastatin in the matrix expansion in anti-Thy1.1 GN was partly by inhibition of mesangial cell proliferation and monocyte/ macrophage recruitment into glomeruli, which were independent of a change in circulating lipids.
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PMID:Simvastatin suppresses glomerular cell proliferation and macrophage infiltration in rats with mesangial proliferative nephritis. 980 88

Mycophenolate mofetil (MMF) represents a powerful immunosuppressant in organ transplantation. The aim of this study was to determine the anti-inflammatory effects of MMF on mesangial cells. Cultured rat mesangial cells were exposed to mycophenolic acid (MPA) in concentrations of 0.1 to 10 microM. MPA inhibited the proliferation of these cells in a dose-dependent manner. A maximum of 98% inhibition was obtained by a 2-d exposure of mesangial cells to > or =5 microM MPA. As expected, the addition of > or =75 microM guanosine prevented the antiproliferative effect of MPA completely. Subsequently, in vivo studies were performed in the anti-Thy1.1 nephritis model. Sixty-six male Wistar rats were investigated: healthy rats (n = 15), treated healthy rats (n = 6), nephritic rats (n = 15), and treated nephritic rats (n = 30). MMF therapy (40 mg/kg body wt per d) of nephritic animals was initiated 2 d before (n = 3) and 6 h (n = 15) or 2 d (n = 12) after induction of nephritis. Renal histology was analyzed at days +6 and +9 after initiation of disease. Therapy of nephritic rats by MMF resulted in a significant amelioration of glomerular histology, assessed by glomerular cellularity, synthesis of alpha-smooth muscle actin, extracellular matrix deposition, and glomerular hypertrophy. Proteinuria, expressed as areas under the curve of protein/creatinine ratios versus time, showed a clear tendency toward a reduction by MMF therapy. Healthy control rats were not negatively affected by exposure to MMF. In summary, this study shows that mesangial cell proliferation can be significantly inhibited by MPA in vitro and in vivo. MMF represents a new approach to the therapy of experimental mesangial cell-mediated forms of glomerulonephritis.
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PMID:Mycophenolic acid: a new approach to the therapy of experimental mesangial proliferative glomerulonephritis. 980 91

Matrix metalloproteinase-2 (MMP-2, gelatinase A) is involved in the inflammatory and sclerotic events of glomerular diseases. Newly identified membrane-type matrix metalloproteinases (MT-MMP) have been shown to activate specifically proMMP-2. To date, several types of MT-MMP have been cloned; however, their expressions in glomerular diseases have not been evaluated. To investigate the role of MT-MMP in glomerular diseases, the glomerular gene expression and enzymatic activity of MT-MMP were examined during the time course of nephritis induced in rats by anti-Thy1.1 antibody injection. Both MT1-MMP and MMP-2 mRNA expression increased prominently 5 and 10 d after anti-Thy1.1 antibody injection and decreased thereafter, as assayed by semiquantitative reverse transcription-PCR. In contrast, there were no remarkable changes in the gene expression of MT2-MMP between normal and diseased tissue, and that of MT3-MMP was not detected in isolated glomeruli by reverse transcription-PCR analysis. The activation of proMMP-2 as analyzed by gelatin zymography correlated with the glomerular MT1-MMP gene expression, suggesting that proMMP-2 was activated by MT1-MMP. Protein and mRNA expression of fibronectin, one of the major mesangial matrix proteins and substrate of MMP-2, were also synchronized with MT1-MMP and MMP-2 expression. In situ hybridization revealed intense MT1-MMP mRNA expression in the proliferating mesangial cells. Interestingly, MT1-MMP gene expression exhibited a similar distribution as alpha-smooth muscle actin expression, which was closely associated with mesangial phenotypic change. These results suggest that among the newly identified MT-MMP, MT1-MMP may play the central role in activation of proMMP-2. Furthermore, the enhancement of MT1-MMP and MMP-2 expression associated with mesangial phenotypic change may contribute to the development of anti-Thy1.1 antibody-induced glomerulonephritis and remodeling of extracellular matrices.
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PMID:Enhanced expression of membrane type-1 matrix metalloproteinase in mesangial proliferative glomerulonephritis. 984 80

Spindle cell melanoma is a rare and distinctive variant of malignant melanoma that is composed of spindled neoplastic cells and includes desmoplastic and neurotropic melanoma. The lack of expression of several melanoma markers may result in a delayed or wrong diagnosis. In this study, we have analyzed in detail the phenotype of the tumor cells in 9 spindle cell melanomas on both paraffin-embedded and frozen material, using melanocytic, neural, and mesenchymal markers. The neoplastic cells expressed the melanocytic markers S-100, Mel-CAM, and NKIC3, but lacked gp100 and Melan-A; tyrosinase and c-Kit were expressed in 2 of 7 cases. Most cases expressed the neural markers p75-nerve growth factor receptor, neural cell adhesion molecule, and NSE. All cases expressed vimentin but lacked the mesenchymal markers CD34 and alpha-smooth muscle actin. Remarkably, all spindle cell melanomas strongly and diffusely expressed the fibroblastic markers Thy1 (CD90) and aminopeptidase N (CD13) and variably expressed the enzyme prolyl-4-hydroxylase, involved in procollagen formation. The coexpression of melanocytic, neural, and fibroblastic markers suggests bidirectional differentiation of neoplastic melanocytes toward (myo)fibroblasts and Schwann cells, a feature that was confirmed by electron microscopy. Furthermore, the lack of CD90 and CD13 staining in a wide range of melanocytic lesions suggests specificity of these markers for spindle cell melanoma.
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PMID:New phenotypical and ultrastructural findings in spindle cell (desmoplastic/neurotropic) melanoma. 1466 57

Previously, we reported a system to enrich mouse fetal hepatic progenitor cells (HPCs) by forming cell aggregates. In this study, we sorted two cell populations, CD49f(+)Thy1(-)CD45(-) cells (CD49f-positive cells) and CD49f(+/-)Thy1(+)CD45(-) cells (Thy1-positive cells), from the cell aggregates using a flow cytometer. CD49f-positive cells stained positive for endodermal specific markers such as alpha-fetoprotein (AFP), albumin (ALB), and cytokeratin 19 (CK19), and are thus thought to be HPCs. However, Thy1-positive cells were a morphologically heterogeneous population; reverse-transcription polymerase chain reaction (RT-PCR) and immunocytochemical analyses revealed the expression of mesenchymal cell markers such as alpha-smooth muscle actin, desmin, and vimentin, but not of AFP, ALB, or CK19. Therefore, Thy1-positive cells were thought to be of a mesenchymal lineage. When these two cell populations were co-cultured, the CD49f-positive colonies matured morphologically and stored a significant amount of glycogen. Furthermore, real-time RT-PCR demonstrated an increased expression of tyrosine amino transferase and tryptophan oxygenase mRNA, and transmission electron microscopy confirmed that co-cultured cells produced mature hepatocytes. However, when CD49f-positive cells were cultured alone or when the two populations were cultured separately, the CD49f-positive cells did not mature. These results indicate that CD49f-positive cells are primitive hepatic endodermal cells with the capacity to differentiate into hepatocytes, and that Thy1-positive cells promote the maturation of CD49f-positive cells by direct cell-to-cell contact. In conclusion, we were able to isolate CD49f-positive primitive hepatic endodermal cells and Thy1-positive mesenchymal cells and to demonstrate the requirement of cell-to-cell contact between these cell types for the maturation of the hepatic precursors.
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PMID:Thy1-positive mesenchymal cells promote the maturation of CD49f-positive hepatic progenitor cells in the mouse fetal liver. 1512 65

Loss of glomerular endothelial cells has been suggested to contribute to the progression of glomerular injury. Although therapeutic angiogenesis induced by administration of bone marrow-derived endothelial progenitor cells has been observed in disease models of endothelial injury, the effects on renal disease have not been clarified. Whether administration of culture-modified bone marrow mononuclear cells would mitigate the glomerular endothelial injury in anti-Thy1.1 nephritis was investigated. After cultivation under conditions that promote endothelial progenitor cell growth, bone marrow mononuclear cells were labeled with CM-DiI, a fluorescence marker, and injected into the left renal artery of Lewis rats with anti-Thy1.1 glomerulonephritis. The decrease in glomerular endothelial cells was significantly attenuated in the left kidney, as compared with the right, in nephritic rats that received the cell infusion. Glomerular injury score, the area positive for mesangial alpha-smooth muscle actin, and infiltration of macrophages were significantly decreased in the left kidney. CM-DiI-positive cells were distributed in glomeruli of the left kidney but not in those of the right kidney. Among CM-DiI-labeled cells incorporated into glomeruli, 16.5 +/- 1.2% of cells were stained with an endothelial marker, rat endothelial cell antigen-1. Culture-modified mononuclear cells secreted 281.2 +/- 85.0 pg of vascular endothelial growth factor per 10(5) cells per day. In conclusion, intra-arterial administration of culture-modified bone marrow mononuclear cells reduced endothelial injury and mesangial activation in anti-Thy1.1 glomerulonephritis. Incorporation into the glomerular endothelial lining and production of angiogenic factor(s) are likely to contribute to the protective effects of culture-modified mononuclear cells against glomerular injury.
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PMID:Intrarenal injection of bone marrow-derived angiogenic cells reduces endothelial injury and mesangial cell activation in experimental glomerulonephritis. 1574 1

Bone marrow-derived cells contribute to glomerular cell turnover and repair, but the cell types involved are unknown. Whether rat mesenchymal stem cells (MSC) can accelerate recovery from damage in rat mesangioproliferative anti-Thy1.1 glomerulonephritis was studied. After injection into the left renal artery on day 2 after disease induction, fluorescently labeled MSC were detected in 20 to 50% of glomeruli and rare intrarenal vessels but not in the tubulointerstitium, in contralateral kidneys, or in medium controls. In control experiments, injected mesangial cells were detected less frequently in glomeruli in comparison with injected MSC. In nephritic outbred Wistar rats, MSC injection led to an approximately 50% reduction of mesangiolysis on days 4 and 6 after disease induction, accompanied by three- to four-fold higher intraglomerular cell proliferation on day 4 and more rapid mesangial reconstitution as detected by alpha-smooth muscle actin expression. Injection of MSC into tail veins or intra-arterial injection of mesangial cells instead of MSC failed to reproduce any of these findings. In inbred Lewis rats, anti-Thy1.1 nephritis followed an aggravated course with transient acute renal failure. Acute renal failure was ameliorated by MSC injection into the left renal artery on day 2 after disease induction. Again, MSC led to more rapid recovery from mesangiolysis, increased glomerular cell proliferation, and reduction of proteinuria by 28%. Double immunostaining of 5-bromo-2'-deoxyuridine-labeled MSC for endothelial, mesangial, or monocyte/macrophage antigens showed that 85 to 95% of MSC that localized in glomeruli on day 6 failed to express these markers. In vitro, MSC secreted high amounts of vascular endothelial growth factor and TGF-beta1 but not PDGF-BB. In conclusion, even low numbers of MSC can markedly accelerate glomerular recovery from mesangiolytic damage possibly related to paracrine growth factor release and not to differentiation into resident glomerular cell types or monocytes/macrophages.
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PMID:Transplanted mesenchymal stem cells accelerate glomerular healing in experimental glomerulonephritis. 1683 40

Gut mesenchymal fibroblasts form complex phenotypical and functional populations. They participate actively in homeostatic maintenance of the extracellular matrix, epithelial barrier function, repair mechanisms and leucocyte migration. In inflammation, they become activated, change matrix expression and synthesize proinflammatory mediators. Subpopulations of mucosal fibroblasts express CD40 and the aim of this study was to define its role in their proinflammatory function. Stable primary fibroblast lines derived from normal mouse colon and inflamed colon from CD4(+) CD45RB(high)-transplanted SCID mice were used as models to explore the role of mucosal fibroblast CD40 in the inflammatory process. Phenotype correlated with in situ fibroblast phenotype in the tissues of origin. Lines from both sources co-expressed CD40 and Thy1.2 independently of alpha-smooth muscle actin. A subpopulation of CD40(+) fibroblasts from normal colon expressed CD40 at high levels and expression was enhanced by interferon (IFN)-gamma treatment, whereas all CD40(+) fibroblasts from colitis expressed at low levels and expression was unaffected by IFN-gamma treatment. Despite lower-level expression of CD40 by cells from colitis, they secreted constitutively interleukin (IL)-6 and C-C chemokine (CCL)2. Ligation of CD40 enhanced secretion of these mediators and induced secretion of CCL3. CD40 in cells from colitis was more responsive to ligation than CD40 on cells from normal tissue and this sensitivity was amplified selectively by the action of IFN-gamma. We conclude that the inflammatory milieu in colitis induces long-lasting changes in phenotype and proinflammatory function in colonic fibroblasts. In particular, proinflammatory signalling from fibroblast CD40 is amplified synergistically by the Th1 effector T cell cytokine, IFN-gamma.
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PMID:Proinflammatory cytokine synthesis by mucosal fibroblasts from mouse colitis is enhanced by interferon-gamma-mediated up-regulation of CD40 signalling. 1722 73

Studies have shown that lipoxin A(4) (LXA(4)) inhibited proliferation of mesangial cells in vitro induced by platelet-derived growth factor, epidermal growth factor, leukotriene D(4) or tumor necrosis factor-alpha. In this study, we investigated the protective effects of 15(R/S)-methyl-LXA(4) on mesangioproliferative nephritis in rats and the signal transduction involved in actions of 15(R/S)-methyl-LXA(4). Mesangioproliferative nephritis was induced by a single intravenous injection of the mouse monoclonal anti-Thy1.1 antibodies. The nephritic rats were treated by intravenous injection of 15(R/S)-methyl-LXA(4) every 8h until the rats were sacrificed. There were increments in glomerular infiltration of leukocytes, expressions of protein and mRNA of interleukin (IL)-1beta and IL-6, activities of nuclear factor-kappaB (NF-kappaB) in nephritic rats from day 1 to 4 after induction of nephritis. The enhanced proteinuria, proliferation score of mesangial cells, glomerular proliferating cell nuclear antigen (PCNA) positive cells, activities of phosphorylated phosphoinositide 3-kinase (PI3-K), Akt(1), alpha-smooth muscle actin (alpha-SMA) and signal transducer and activator of transcription 3(STAT(3)), and reduced expression of p27(kip1) were found on day 4 after induction of nephritis. Treatment of nephritic rats with 15(R/S)-methyl-LXA(4) significantly reduced the protenuria, glomerular infiltration of leukocyte, expressions of protein and mRNA of IL-1beta and IL-6, proliferation score of mesangial cells, glomerular PCNA positive cells, activities of phosphorylated PI3-K, Akt(1), alpha-SMA, NF-kappaB and STAT(3), and ameliorated the decrement in p27(kip1) induced by anti-Thy1.1 antibodies. Protective effects of 15(R/S)-methyl-LXA(4) on nephritis induced by anti-Thy1.1 antibodies were related to PI3-K/Akt(1)/p27(kip1)/cyclin pathway, STAT(3) and NF-kappaB pathway-dependent signal transduction.
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PMID:Signal transduction involved in protective effects of 15(R/S)-methyl- lipoxin A(4) on mesangioproliferative nephritis in rats. 1732 90


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