1,308 research outputs found

    Novel Omega-3 Fatty Acid Epoxygenase Metabolite Reduces Kidney Fibrosis.

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    Cytochrome P450 (CYP) monooxygenases epoxidize the omega-3 polyunsaturated fatty acid (PUFA) docosahexaenoic acid into novel epoxydocosapentaenoic acids (EDPs) that have multiple biological actions. The present study determined the ability of the most abundant EDP regioisomer, 19,20-EDP to reduce kidney injury in an experimental unilateral ureteral obstruction (UUO) renal fibrosis mouse model. Mice with UUO developed kidney tubular injury and interstitial fibrosis. UUO mice had elevated kidney hydroxyproline content and five-times greater collagen positive fibrotic area than sham control mice. 19,20-EDP treatment to UUO mice for 10 days reduced renal fibrosis with a 40%-50% reduction in collagen positive area and hydroxyproline content. There was a six-fold increase in kidney α-smooth muscle actin (α-SMA) positive area in UUO mice compared to sham control mice, and 19,20-EDP treatment to UUO mice decreased α-SMA immunopositive area by 60%. UUO mice demonstrated renal epithelial-to-mesenchymal transition (EMT) with reduced expression of the epithelial marker E-cadherin and elevated expression of multiple mesenchymal markers (FSP-1, α-SMA, and desmin). Interestingly, 19,20-EDP treatment reduced renal EMT in UUO by decreasing mesenchymal and increasing epithelial marker expression. Overall, we demonstrate that a novel omega-3 fatty acid metabolite 19,20-EDP, prevents UUO-induced renal fibrosis in mice by reducing renal EMT

    Modulation of the unfolded protein response by tauroursodeoxycholic acid counteracts apoptotic cell death and fibrosis in a mouse model for secondary biliary liver fibrosis

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    The role of endoplasmic reticulum stress and the unfolded protein response (UPR) in cholestatic liver disease and fibrosis is not fully unraveled. Tauroursodeoxycholic acid (TUDCA), a hydrophilic bile acid, has been shown to reduce endoplasmic reticulum (ER) stress and counteract apoptosis in different pathologies. We aimed to investigate the therapeutic potential of TUDCA in experimental secondary biliary liver fibrosis in mice, induced by common bile duct ligation. The kinetics of the hepatic UPR and apoptosis during the development of biliary fibrosis was studied by measuring markers at six different timepoints post-surgery by qPCR and Western blot. Next, we investigated the therapeutic potential of TUDCA, 10 mg/kg/day in drinking water, on liver damage (AST/ALT levels) and fibrosis (Sirius red-staining), in both a preventive and therapeutic setting. Common bile duct ligation resulted in the increased protein expression of CCAAT/enhancer-binding protein homologous protein (CHOP) at all timepoints, along with upregulation of pro-apoptotic caspase 3 and 12, tumor necrosis factor receptor superfamily, member 1A (TNFRsf1a) and Fas-Associated protein with Death Domain (FADD) expression. Treatment with TUDCA led to a significant reduction of liver fibrosis, accompanied by a slight reduction of liver damage, decreased hepatic protein expression of CHOP and reduced gene and protein expression of pro-apoptotic markers. These data indicate that TUDCA exerts a beneficial effect on liver fibrosis in a model of cholestatic liver disease, and suggest that this effect might, at least in part, be attributed to decreased hepatic UPR signaling and apoptotic cell death

    Role of TGFbRII in myeloid cell mediated regenerative processes and fibroplasia

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    Tissue repair and fibrosis are controlled by the interaction of different cell lineages, their soluble factors and matrix signals. Recently, macrophages have been found to be crucial for proper tissue repair. In particular, the role of Transforming growth factor-β1 (TGF-β1) has been extensively studied during tissue repair and fibrosis. Fibrosis is characterized by excessive production and deposition of extracellular matrix, as well as immune cell infiltration. Macrophages are one of the main sources of TGF-β1. So far, studies on the mechanisms of tissue repair and fibrosis have mainly focused on macrophages or TGF-β1 individually. However, the specific function of TGF-β1 on macrophages in tissue repair and fibrosis still needs to be elucidated. To understand the macrophage specific role of TGFβ1-TGFβRII signaling in tissue repair and fibrosis, we generated a mouse model, which lacks TGFβRII in myeloid cells (TGFβRIIfl/fl/LysMCre). We observed that during mechanical tissue injury TGFβRII signaling in macrophages contributes to wound contraction, possibly by cross—talk between macrophages and fibroblasts. The attenuated wound contraction was accompanied by impaired myofibroblast differentiation and collagen deposition. However, the loss of TGFβRII signaling in macrophages did not lead to reduced expression of TGF- β1, which we proposed as one of the primary mechanisms in wound tissue underlying reduced myofibroblast formation observed in TGFβRIIfl/fl/LysMCre mice. Generation of cutaneous fibrosis by bleomycin injection for two and four weeks resulted in reduced fibrosis in TGFβRIIfl/fl/LysMCre mice, compared to control mice. The mechanisms leading to this phenotype were associated with reduced infiltration of immune cells, reduced deposition of collagen and diminished production of inflammatory mediators such as IL-1β, TNF-α and osteopontin-1 at the early stage of fibrosis formation. At the later stage, the expression of inflammatory mediators in TGFβRIIfl/fl/LysMCre mice was not altered compared to control mice, possibly due to compensatory mechanisms. Our data leads to the hypothesis that the reduced fibrosis is caused by the reduced expression of inflammatory mediators and accumulation of immune cells at the early stage of fibrosis in TGFβRIIfl/fl/LysMCre mice. Our results provide new insights into the crucial role of macrophage specific TGFβRII signaling in tissue repair and fibrosis

    Angiotensin II type 1 receptor antagonists alleviate muscle pathology in the mouse model for laminin-alpha2-deficient congenital muscular dystrophy (MDC1A)

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    BACKGROUND: Laminin-alpha2-deficient congenital muscular dystrophy (MDC1A) is a severe muscle-wasting disease for which no curative treatment is available. Antagonists of the angiotensin II receptor type 1 (AT1), including the anti-hypertensive drug losartan, have been shown to block also the profibrotic action of transforming growth factor (TGF)-beta and thereby ameliorate disease progression in mouse models of Marfan syndrome. Because fibrosis and failure of muscle regeneration are the main reasons for the severe disease course of MDC1A, we tested whether L-158809, an analog derivative of losartan, could ameliorate the dystrophy in dyW/dyW mice, the best-characterized model of MDC1A. METHODS: L-158809 was given in food to dyW/dyW mice at the age of 3 weeks, and the mice were analyzed at the age of 6 to 7 weeks. We examined the effect of L-158809 on muscle histology and on muscle regeneration after injury as well as the locomotor activity and muscle strength of the mice. RESULTS: We found that TGF-beta signaling in the muscles of the dyW/dyW mice was strongly increased, and that L-158809 treatment suppressed this signaling. Consequently, L-158809 reduced fibrosis and inflammation in skeletal muscle of dyW/dyW mice, and largely restored muscle regeneration after toxin-induced injury. Mice showed improvement in their locomotor activity and grip strength, and their body weight was significantly increased. CONCLUSION: These data provide evidence that AT1 antagonists ameliorate several hallmarks of MDC1A in dyW/dyW mice, the best-characterized mouse model for this disease. Because AT1 antagonists are well tolerated in humans and widely used in clinical practice, these results suggest that losartan may offer a potential future treatment of patients with MDC1A

    The histological characteristics and clinical outcomes of lung cancer in patients with combined pulmonary fibrosis and emphysema(CPFE(気腫合併肺線維症)合併肺癌患者の組織学的特徴及び予後)

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    信州大学(Shinshu university)博士(医学)雑誌に発表。CANCER MEDICINE. 5(10):2721-2730 (2016); doi:10.1002/cam4.858.Thesis張 萌. The histological characteristics and clinical outcomes of lung cancer in patients with combined pulmonary fibrosis and emphysema(CPFE(気腫合併肺線維症)合併肺癌患者の組織学的特徴及び予後). 信州大学, 2017, 博士論文.doctoral thesi

    E2F1 Suppresses Oxidative Metabolism and Endothelial Differentiation of Bone Marrow Progenitor Cells

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    RATIONALE: The majority of current cardiovascular cell therapy trials use bone marrow progenitor cells (BM PCs) and achieve only modest efficacy; the limited potential of these cells to differentiate into endothelial-lineage cells is one of the major barriers to the success of this promising therapy. We have previously reported that the E2F transcription factor 1 (E2F1) is a repressor of revascularization after ischemic injury. OBJECTIVE: We sought to define the role of E2F1 in the regulation of BM PC function. METHODS AND RESULTS: Ablation of E2F1 (E2F1 deficient) in mouse BM PCs increases oxidative metabolism and reduces lactate production, resulting in enhanced endothelial differentiation. The metabolic switch in E2F1-deficient BM PCs is mediated by a reduction in the expression of pyruvate dehydrogenase kinase 4 and pyruvate dehydrogenase kinase 2; overexpression of pyruvate dehydrogenase kinase 4 reverses the enhancement of oxidative metabolism and endothelial differentiation. Deletion of E2F1 in the BM increases the amount of PC-derived endothelial cells in the ischemic myocardium, enhances vascular growth, reduces infarct size, and improves cardiac function after myocardial infarction. CONCLUSION: Our results suggest a novel mechanism by which E2F1 mediates the metabolic control of BM PC differentiation, and strategies that inhibit E2F1 or enhance oxidative metabolism in BM PCs may improve the effectiveness of cell therapy

    Thrombospondin-3 augments injury-induced cardiomyopathy by intracellular integrin inhibition and sarcolemmal instability.

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    Thrombospondins (Thbs) are a family of five secreted matricellular glycoproteins in vertebrates that broadly affect cell-matrix interaction. While Thbs4 is known to protect striated muscle from disease by enhancing sarcolemmal stability through increased integrin and dystroglycan attachment complexes, here we show that Thbs3 antithetically promotes sarcolemmal destabilization by reducing integrin function, augmenting disease-induced decompensation. Deletion of Thbs3 in mice enhances integrin membrane expression and membrane stability, protecting the heart from disease stimuli. Transgene-mediated overexpression of α7β1D integrin in the heart ameliorates the disease predisposing effects of Thbs3 by augmenting sarcolemmal stability. Mechanistically, we show that mutating Thbs3 to contain the conserved RGD integrin binding domain normally found in Thbs4 and Thbs5 now rescues the defective expression of integrins on the sarcolemma. Thus, Thbs proteins mediate the intracellular processing of integrin plasma membrane attachment complexes to regulate the dynamics of cellular remodeling and membrane stability
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