过氧化物酶体增殖物激活受体与肝纤维化

过氧化物酶体增殖物激活受体(PPARs)属于核受体超家族成员,具有广泛的生理作用,最近研究发现过氧化物酶体增殖物激活受体可以在肝星状细胞表达,并且能够调控肝星状细胞从静止表型向活化表型的转化,在肝纤维化的发生中起重要作用。本文就过氧化物酶体增殖物激活受体的结构、配体及其与肝纤维化的关系作一综述。     

过氧化物酶体增殖物激活受体γ与肝纤维化关系的研究进展

过氧化物酶体增殖物激活受体（peroxisome proliferator activated receptors，PPARs）属Ⅱ型核激素受体超家族成员，1990年首先由Issemann等从小鼠肝脏克隆得到，因其被过氧化物酶体增殖物活化后能诱导肝脏过氧化物酶体增殖而得名。迄今已发现PPARα、β和γ3种亚型，β亚型又称δ亚型；它们在结构、功能及组织分布上均有差异。PPARs具有多种生物学效应，已知PPARs与许多慢性疾病如肥胖、糖尿病、动脉硬化和癌症等的发生有关。PPARs也是重要的肝脏代谢调节分子，肝星状细胞（HSC）表达PPARγ。本文就PPARγ与肝纤维化关系的研究进展作一综述。     

过氧化物酶体增殖物激活受体γ与肝星状细胞

过氧化物酶体增殖物激活受体 (ｐｅｒｏｘｉｓｏｍｅｐｒｏｌｉｆｅｒａｔｏｒ ａｃｔｉ ｖａｔｅｄｒｅｃｅｐｔｏｒｓ ,ＰＰＡＲｓ)是配体活化的核转录因子 ,属于核激素受体超家族[1] 。最初由于其被配体激活时能诱导肝脏过氧化物酶体增殖而被命名。在两栖类、啮齿类和人类表     

过氧化物酶体增殖物激活受体γ在肝纤维化中作用

肝纤维化是各种慢性肝疾病向肝硬化发展的中间过程,是所有慢性肝疾病的共同病理基础[1,2],而肝损伤(肝实质炎症、坏死)激活肝星状细胞(hepatic stellate cell,HSC)引起大量细胞外基质(extracellular matrix,ECM)沉积,是肝纤维化发生机制的中心环节[3]。     

过氧化物酶体增殖物活化受体γ在肝星状细胞活化过程中的动态演变

目的 探讨过氧化物酶体增殖物活化受体γ(PPAR γ)在肝星状细胞(HSC)活化过程中的作用。方法 采用形态学、RT-PCR方法观察从正常Wistar大鼠分离的HSC在体外培养自发活化过程中以及以二甲墓亚硝胺诱导肝纤维化形成过程中HSC在体活化时PPAR γ的动态演变。结果 HSC在体外培养自发活化过程中,新鲜分离的HSC PPAR γ mRNA表达水平最高(0.71±0.01),培养第3天时即开始减低(0.48±0.03,t=19.8372,P<0.01),培养第7天后PPAR γ的表达减低70％以上,传2代时几乎检测不到。以二甲基亚硝胺诱导肝纤维化形成过程中,对照组大鼠新鲜分离的HSC表达PPAR γ(0.76±0.01),第3次注射二甲基亚硝胺后PPAR γ的表达水平显著减低(0.46±0.02,t=29.5318,P<0.01),一周末时PPAR γ表达较正常大鼠下降66％,第2周、第3周时PPAR γ几乎检测不出。结论 PPAR γ的表达参与HSC静止表型的维持,且PPAR γ表达降低是HSC由静止向活化表型转化过程的早期事件。     

过氧化物酶体增殖物激活受体γ在肝星状细胞静止表型维持中的作用

肝星状细胞(hepatic stellate cell,HSC)的激活是肝纤维化形成的关键,因此如何维持HSC静止表型是当前的研究热点.过氧化物酶体增殖物激活受体Υ是由配体激活的核转录因子,通过影响脂肪细胞及瘦素、细胞因子、转录因子、细胞周期及与法呢醇X受体的协同作用维持HSC静止状态,本文就此作一综述.     

过氧化物酶体增殖物激活受体γ及其配体与肝纤维化研究进展

过氧化物酶体增殖物激活受体(PPAR)属核激素受体超家族成员,是调节脂肪细胞分化和能量代谢的关键性转录因子.PPARγ是其中一个亚型,在人类表达于巨噬细胞、肝星状细胞等,其生物学功能复杂.近年来,对PPARγ及其配体在肝纤维化中的作用及其与肝纤维化的关系进行了较多的研究.此文就PPARγ及其配体与肝纤维化的研究进展作一综述.     

过氧化物酶体增殖物激活受体与肝纤维化

各种病因引起的慢性肝病,各种损肝因素所致的肝脏损伤,都可能发生肝细胞坏死、炎症并有继发纤维化的病理特征.     

过氧化物酶体增殖物活化受体γ配体15d-PGJ2对肝星状细胞增殖活化的影响

目的观察过氧化物酶体增殖物活化受体γ(PPARγ)的天然配体15d-PGJ2对HSC增殖及活化的影响,以探讨PPARγ在HSC活化过程中的作用。方法采用MTT法和RT-PCR方法观察5μmol/L及10μmol/L 15d-PGJ2对体外培养的HSC自发活化及血小板衍生生长因子(PDGF)引起的HSC增殖及活化的影响。结果以5μmol/L 15d-PGJ2处理原代HSC 3 d后,可明显抑制HSC活化标志物α-平滑肌肌动蛋白的表达,而PPARγ的表达较未处理组明显增高(0.64±0.03对比0.09±0.01,t=36.0517,P<0.01);15d-PGJ2可剂量依赖性地抑制PDGF引起的HSC增殖;经5μmol/L和10μmol/L 15d-PGJ2预处理后再用PDGF干预,则PPARγ的表达较单用PDGF干预组明显增高(分别为0.03±0.02对比0.60±0.03,t=42.6616,P<0.01;以及0.03±0.02对比0.69±0.04,t=33.83,P<0.01),而HSC的活化指标α-平滑肌肌动蛋白、α1(I)型胶原及单核细胞趋化蛋白-1的表达则受抑制。结论激活PPARγ可调控HSC的促纤维化和促炎症作用,促进PPARγ的表达可能成为抗肝纤维化的新手段。     

过氧化物酶体增殖物激活受体通路与心肌纤维化

多项研究证实,心力衰竭、心肌梗死后通过一系列神经-内分泌途径激活导致左室重塑,发生心脏不良事件。心肌间质重塑在左室重塑过程中发挥着重要的作用。心肌间质纤维化的直接后果是舒张功能减退,最终出现收缩功能障碍,发生心力衰竭;同时与心律失常、心源性猝死的发生密切相关。目前对于心肌纤维化发生、发展机制的认识还处于探索阶段,临床工作中缺乏规范的诊断、评价方法,缺乏有效、系统的药物治疗和干预措施。近年来的研究发现,过氧化物酶体增殖物激活受体(PPARs)通路与心肌纤维化的发生、发展有着密切的关系。因此,干预PPARs通路,可能…     

Effect of ligand of peroxisome proliferator-activated receptor γ on the biological characters of hepatic stellate cells

AIM: To study the effect of rosiglitazone, which is a ligand of peroxisome proliferator-activated receptor gamma (PPARgamma), on the expression of PPARgamma in hepatic stellate cells (HSCs) and on the biological characteristics of HSCs. METHODS: The activated HSCs were divided into three groups: control group, 3 micromol/L rosiglitazone group, and 10 micromol/L rosiglitazone group. The expression of PPARgamma, alpha-smooth muscle actin (alpha-SMA), and type I and III collagen was detected by RT-PCR, Western blot and immunocytochemical staining, respectively. Cell proliferation was determined with methylthiazolyltetrazolium (MTT) colorimetric assay. Cell apoptosis was demonstrated with flow cytometry. RESULTS: The expression of PPARgamma at mRNA and protein level markedly increased in HSCs of 10 micromol/L rosiglitazone group (t value was 10.870 and 4.627 respectively, P<0.01 in both). The proliferation of HSCs in 10 micromol/L rosiglitazone group decreased significantly (t = 5.542, P<0.01), alpha-SMA expression level and type I collagen synthesis ability were also reduced vs controls (t value = 10.256 and 14.627 respectively, P<0.01 in both). The apoptotic rate of HSCs significantly increased in 10 micromol/L rosiglitazone group vs control (chi(2) = 16.682, P<0.01). CONCLUSION: By increasing expression of PPARgamma in activated HSCs, rosiglitazone, an agonist of PPARgamma, decreases alpha-SMA expression and type I collagen synthesis, inhibits cell proliferation, and induces cell apoptosis.     

罗格列酮调控PPARγ/HO-1的表达抑制肝星状细胞增殖

目的探讨罗格列酮(RGZ)对肝星状细胞(HSCs)中过氧化酶体增殖物激活受体γ(PPARγ)及血红素加氧酶-1(HO-1)表达的影响。方法以体外活化的肝星状细胞(HSC-T6)为研究对象,分为:空白对照组、RGZ干预组、RGZ与锌原卟啉-Ⅸ(ZnPP-Ⅸ)共同干预组。采用四甲基偶氮唑盐法检测HSC-T6的增殖情况,酶联免疫吸附试验检测细胞上清液中透明质酸(HA)及Ⅲ型前胶原肽(PⅢP)含量,实时荧光定量PCR、蛋白质印迹法及免疫细胞化学技术检测PPARγ、HO-1的mRNA及蛋白相对表达水平。多组间样本均数的比较采用单因素方差分析,组间比较采用LSD检验。结果RGZ干预组HSC-T6增殖活性及HA、PⅢP表达较空白对照组显著下降(P值均<0.01),但PPARγ、HO-1的mRNA及蛋白相对表达量均较空白对照组显著增加(PPARγ:2.97±0.22对比1.07±0.05,0.96±0.08对比0.31±0.03;HO-1:4.28±0.73对比1.80±0.36,1.83±0.26对比0.61±0.09),P值均<0.01,差异有统计学意义。RGZ与ZnPP-Ⅸ共同干预组同RGZ干预组比较,HSC-T6增殖活性及HA、PⅢP表达有所升高(P值均<0.05);HO-1的的mRNA相对表达量(3.16±0.38对比4.28±0.73)和蛋白相对表达水平(1.31±0.17对比1.83±0.26)降低,P值均<0.05,差异有统计学意义;PPARγ的mRNA及蛋白相对表达量比较,差异无统计学意义(P值均>0.05),但呈下降趋势。RGZ与ZnPP-Ⅸ共同干预组与空白对照组HO-1的mRNA相对表达量(1.80±0.36)及蛋白相对表达量(0.61±0.09)比较,明显增高,P值均<0.05。免疫细胞化学染色同上述结果一致。结论罗格列酮诱导PPARγ表达增加进而抑制HSC增殖活化及胶原产生的作用可能是通过调控其下游HO-1的表达而实现的。     

Peroxisome proliferator-activated receptor gamma inhibits hepatic fibrosis in rats

BACKGROUND:Hepatic fibrosis is a necessary step in the development of hepatic cirrhosis.In this study we used lentiviral vector-mediated transfection technology to evaluate the effect of peroxisome proliferator-activated receptor gamma(PPAR-γ) on rat hepatic fibrosis. METHODS:Hepatic fibrosis in rats was induced by CCl4 for 2 weeks(early fibrosis)and 8 weeks(sustained fibrosis).The rats were randomly divided into four groups:normal control, fibrosis,blank vector,and PPAR-γ.They were infected with the recomb...     

肝星状细胞的活化与肝纤维化

肝纤维化是机体对损伤的一种修复作用，即使可以应用基因或其他疗法彻底消除纤维化，但机体对抑制或消除纤维化后将产生何种反应及后果尚难预测。肝星状细胞（hepatic stellate cells，HSC）是引起肝纤维化的主要细胞，对HSC与其活化型一肌成纤维细胞（myofibroblast，MF）在肝损伤中作用的研究已颇为深入，而HSC激活在肝纤维化发生、发展中的作用甚为重要。     

肝星状细胞的可塑性及其对肝纤维化的意义

在肝纤维化形成过程中,肝星状细胞(hepatic stellate cells,HSC)发挥着重要的作用.基础和临床研究结果显示,在特殊的内环境因素的影响下HSC具有朝多方向分化的潜能.对HSC命运的干预能够在一定程度上预防肝纤维化的发生,甚至逆转肝纤维化,因此HSC的可塑性研究可能为慢性肝病治疗开辟一条新途径.本文就HSC的起源、结构、可塑性及其对肝纤维化的潜在治疗意义作一综述.     

姜黄素预防肝纤维化作用与肝星状细胞的关系

目的观察姜黄素预防大鼠肝纤维化作用及活化肝星状细胞(HSC)的数目、分布、凋亡等变化,并探讨两者间的关系。方法以四氯化碳制作大鼠肝纤维化模型,同时按每100 g体重分别给予20、10、5 mg姜黄素灌胃处理,设立正常对照组、肝纤维化组和阳性对照组;8周后处死大鼠,留取肝左叶行HE、Masson染色,参照肝纤维化半定量计分系统进行肝纤维化程度评分,免疫组织化学方法检测α-平滑肌肌动蛋白以了解活化HSC的数量变化, TUNEL与肌源性特异性标志物结合蛋白(Desmin)免疫组织化学双染法检测HSC凋亡。结果姜黄素可明显改善四氯化碳所致大鼠肝纤维化的病理学改变;α-平滑肌肌动蛋白在肝纤维化时表达明显增多,姜黄素使活化HSC数量减少, }[SC凋亡增加,与对照组比较差异具有统计学意义(P<0．05),且具有量效关系。结论姜黄素可抑制HSC活化、增殖,诱导HSC凋亡,可能为预防肝纤维化的作用机制之一。     

肝星状细胞及相关细胞因子在肝纤维化形成中的作用

肝纤维化(hepatic fibrosis)是指肝脏内弥漫性细胞外基质(extracellular matrix,ECM)过度沉积的病理过程.肝星状细胞(hepatic stellate cells,HSC)被认为是ECM的主要来源细胞,在肝纤维化发生发展中起着关键作用.另外,各种病因引起肝细胞损伤时,Kupffers细胞(KF),肝窦内皮细胞等分泌一系列细胞因子,通过旁分泌和自分泌方式作用于邻近的HSC,影响其增殖,趋化和ECM代谢.因此,HSC及细胞因子与肝纤维化的发生发展关系极为密切,阐明其关系,有助于以HSC为靶点的肝纤维化方面的研究,现就其关系分别综述如下.     

Fasudil prevents liver fibrosis via activating natural killer cells and suppressing hepatic stellate cells

BACKGROUNDFasudil, as a Ras homology family member A (RhoA) kinase inhibitor, is used to improve brain microcirculation and promote nerve regeneration clinically. Increasing evidence shows that Rho-kinase inhibition could improve liver fibrosis.AIMTo evaluate the anti-fibrotic effects of Fasudil in a mouse model of liver fibrosis induced by thioacetamide (TAA). METHODSC57BL/6 mice were administered TAA once every 3 d for 12 times. At 1 wk after induction with TAA, Fasudil was intraperitoneally injected once a day for 3 wk, followed by hematoxylin and eosin staining, sirius red staining, western blotting, and quantitative polymerase chain reaction (qPCR), and immune cell activation was assayed by fluorescence-activated cell sorting. Furthermore, the effects of Fasudil on hepatic stellate cells and natural killer (NK) cells were assayed in vitro.RESULTSFirst, we found that TAA-induced liver injury was protected, and the positive area of sirius red staining and type I collagen deposition were significantly decreased by Fasudil treatment. Furthermore, western blot and qPCR assays showed that the levels of alpha smooth muscle actin (α-SMA), matrix metalloproteinase 2 (MMP-2), MMP-9, and transforming growth factor beta 1 (TGF-β1) were inhibited by Fasudil. Moreover, flow cytometry analysis revealed that NK cells were activated by Fasudil treatment in vivo and in vitro. Furthermore, Fasudil directly promoted the apoptosis and inhibited the proliferation of hepatic stellate cells by decreasing α-SMA and TGF-β1. CONCLUSIONFasudil inhibits liver fibrosis by activating NK cells and blocking hepatic stellate cell activation, thereby providing a feasible solution for the clinical treatment of liver fibrosis.     

肝星状细胞在血吸虫病肝纤维化形成及调控中的作用

肝星状细胞(hepatic stellate cell,HSC)是肝脏组织的一种间质细胞,具有多种生理功能,对肝纤维化的形成与转归起到关键作用.HSC同样在血吸虫病肝纤维化形成及其调节中起到重要作用.该文就HSC的生物学特性、活化及其在血吸虫病肝纤维化中的作用作一综述.     

Effect of ligand of peroxisome proliferator-activated receptor γ on the biological characters of hepatic stellate cells

AIM: To study the effect of rosiglitazone, which is a ligand of peroxisome proliferator-activated receptor gamma (PPARγ), on the expression of PPARγ in hepatic stellate cells (HSCs) and on the biological characteristics of HSCs.METHODS: The activated HSCs were divided into three groups: control group, 3 μmol/L rosiglitazone group, and 10 μmol/L rosiglitazone group. The expression of PPARγ,α-smooth muscle actin (α-SMA), and type Ⅰ and Ⅲ collagen was detected by RT-PCR, Western blot and immunocytochemical staining, respectively. Cell proliferation was determined with methylthiazolyltetrazolium (MTT) colorimetric assay. Cell apoptosis was demonstrated with flow cytometry.RESULTS: The expression of PPARγ at mRNA and protein level markedly increased in HSCs of 10 μmol/L rosiglitazone group (tvalue was 10.870 and 4.627 respectively, P<0.01in both). The proliferation of HSCs in 10 μmol/L rosiglitazone group decreased significantly (t = 5.542, P<0.01), α-SMA expression level and type Ⅰ collagen synthesis ability were also reduced vs controls (tvalue= 10.256 and 14.627respectively, P<0.01 in both). The apoptotic rate of HSCs significantly increased in 10 μmol/L rosiglitazone group vs control (x2= 16.682, P<0.01).CONCLUSION: By increasing expression of PPARγ in activated HSCs, rosiglitazone, an agonist of PPARγ,decreases α-SMA expression and type Ⅰ collagen synthesis,inhibits cell proliferation, and induces cell apoptosis.