过氧化物酶体增殖物激活受体γ与心室重构

研究表明,过氧化物酶体增殖物激活受体γ（PPAR-γ）存在于多种动物的心血管组织内,激活PPAR-γ可改善胰岛素抵抗,影响动脉粥样硬化病变的发生发展,并降低血压。近年来很多研究发现PPAR-γ及其激动剂可以抑制心室重构,但其作用机制有待阐明。     

过氧化物酶体增殖物激活受体γ抗动脉粥样硬化研究进展

<正>过氧化物酶体增殖物激活受体(peroxisome proliferator-activated receptors,PPARs)属于核受体家族成员,有3种亚型即PPARα、PPARβ/δ和PPARγ,其中以PPARγ与动脉粥样硬化(atherosclerosis,AS)的关系最为密切。最近研究表明,PPARγ在AS和炎症细胞中均有表达,其通过调节糖脂代     

过氧化物酶体增殖物激活受体γ与肝癌

过氧化物酶体增殖物激活受体(PPAR)γ是核激素受体超家族成员,在肝癌组织及细胞株中均有表达.PPARγ可调节细胞因子、炎症介质的产生,参与氧自由基生成和氧化应激,调节细胞外基质平衡,调控细胞周期及凋亡、增殖活性,在肝癌的生物学行为中发挥重要作用.     

过氧化物酶体增殖物激活受体γ的心血管保护作用

过氧化物酶体增殖物激活受体γ(peroxisome proliferator-activated receptorγ,PPARγ)是一类由配体激活的核转录因子.最近的研究表明它与动脉粥样硬化、血管再狭窄、高血压、血脂异常及心力衰竭等心血管疾病的病理过程密切相关,有可能成为心血管疾病治疗的一个新的靶点.     

过氧化物酶体增殖物激活受体γ与糖尿病肾病研究进展

糖尿病肾病(diabetic nephropathy,DN)是糖尿病最常见和最严重的慢性并发症之一,肾内糖代谢紊乱与血流动力学因素以及炎症反应被认为是糖尿病肾病的发病机制。近年研究表明过氧化物酶体增殖物激活受体γ(peroxisome proliferator-activated receptorγ,PPARγ)属于由配体激活的Ⅱ型核受体超家族成员,在DN发病中亦发挥重要作用。     

罗格列酮对日本血吸虫病肝纤维化小鼠肝组织核因子-κB和过氧化物酶体增殖物激活受体γ表达的影响

目的观察日本血吸虫病肝纤维化小鼠肝脏肝组织核因子-κB(NF-κB)的活性和过氧化物酶体增殖物激活受体γ(PPARγ)的表达,及PPARγ配体罗格列酮对其表达的影响.方法50只昆明小鼠,随机分为正常对照组、感染对照组、吡喹酮治疗组、罗格列酮治疗组及罗格列酮加吡喹酮治疗组.除正常对照组外,其余各组均建立血吸虫病肝纤维化小鼠模型.用HE染色观察肝组织光镜下的病理改变.用Western blot方法,实时荧光定量PCR反应观察小鼠肝组织NF-κB的活性变化与PPARγmRNA的表达.结果罗格列酮加吡喹酮治疗组小鼠肝脏的炎性反应和纤维化病理改变较其他模型组轻(P＜0.05).感染对照组NF-κB活性(141.11±15.37)最强,明显高于其余各组(正常对照组78.89±18.12;吡喹酮组112.89±20.17罗格列酮组108.89±20.47;罗格列酮加吡喹酮组88.89±19.34)(P＜0.05).感染对照组[-27.315±(-6.348)].及吡喹酮治疗组[-25.647±(-5.694)]PPARγ mRNA表达较正常对照组[-16.557±(.3.022)]及罗格列酮治疗组[-18.217±(-4.498)]、罗格列酮加吡喹酮治疗组[-18.212±(-3.909)]显著减弱(P＜0.05).结论PPARγ及NF-κB在血吸虫病肝纤维化形成中起一定作用.PPARγ配体罗格列酮有明显的抗日本血吸虫病肝纤维化效应,其抗纤维化机制与PPARγ配体激活PPARγ表达的同时抑制NF-κB的活性有关.     

过氧化物酶体增殖物激活受体γ与肥胖相关的炎症调节

肥胖者的脂肪组织分泌大量的炎症因子,且有巨噬细胞的浸润,肥胖代表了一个慢性低度炎症状态。过氧化物酶体增殖物激活受体调节脂质代谢,参与胰岛素抵抗。新近发现过氧化物酶体增殖物激活受体γ通过拮抗核因子-кB、激活蛋白-1等信号通路来调节肥胖相关的炎症基因转录,减轻肥胖相关的炎症反应,从而成为一个治疗靶点。     

过氧化物酶体增殖物激活受体γ激动剂与动脉粥样硬化

1过氧化物酶体增殖物激活受体γ(peroxisomeproliferators-activated receptor-gamma,PPARγ)与PPARγ激动剂PPARγ属于核受体超家族的一员;由于启动子和拼接方式不同,PPARγ可以分为PPARγ1、PPARγ2、PPARγ3三种亚型,功能涉及脂肪酸代谢、脂肪细胞分化以及抑制巨噬细胞激活。PPARγ与配体结合而被激活后,与视黄醛X受体(retinoidXreceptor,RXR)结合形成异源二聚体,转移到细胞核,再结合于特定DNA序列-PPARγ目标基因启动子应答元件(peroxisome proliferators responsiveelement,PPRE),启动目标基因———糖、脂代谢相…     

过氧化物酶体增殖物激活受体与动脉粥样硬化

过氧化物酶体增殖物激活受体（PPAR）属Ⅱ型核受体超家族成员。存在3种亚型,即PPARα、PPARβ和PARγ。PPARα、PPARγ在动脉粥样硬化有关的脂质代谢和血管炎症中起关键作用。PPARα激活后在多个水平增加脂肪酸的分解;PPARγ在控制脂肪的储存和释放、促进脂细胞分化等发挥重要作用。PPAR在动脉粥样斑块处表达。在相应配体的作用下,PPAR作用于过氧化物酶增殖物反应元件（PPRE）,或负向影响如核因子（NF）－κβ等其它一些信号传递途径,下调某些致病基因的表达,抑制单核细胞聚集到动脉粥样斑块,阻止动脉粥样硬化的过程。     

过氧化物酶体增殖物激活受体与胰岛素抵抗的研究进展

过氧化物酶体增殖物激活受体是一类由配体调节的核激素受体,属于核激素受体超家族。新近研究显示过氧化物酶体增殖物激活受体α、过氧化物酶体增殖物激活受体γ活性的中度缺失均与胰岛素抵抗关系密切,这很可能为2型糖尿病的治疗提供新的靶向。     

阿托伐他汀增加单核细胞过氧化物酶增殖体激活受体γ表达改善炎症反应

目的　研究阿托伐他汀对人外周血单核细胞过氧化物酶增殖体激活受体γ(PPARγ)及其单核细胞趋化蛋白 1(MCP 1)和金属蛋白酶 9(MMP 9)的影响。方法　分离健康人外周血单核细胞并加入不同浓度的阿托伐他汀 (0 1～ 10 μmol/L)共同培养 2 4h ,采用RT PCR检测PPARγ和MCP 1的表达。并采用定量夹心酶免疫吸附测定法检测单核细胞培养上清液中MMP 9和MCP 1的浓度。结果　阿托伐他汀能明显增加人外周血单核细胞PPARγ的表达 ,1、10 μmol/L阿托伐他汀使PPARγ的表达明显增加 (P <0 0 5 ) ,并能明显抑制人外周血单核细胞MCP 1的表达和分泌。与基础状态相比 ,阿托伐他汀降低单核细胞培养上清MCP 1和MMP 9浓度分别达 73%和 6 2 % (P <0 0 5 ) ,呈浓度依赖性。结论　阿托伐他汀能够抑制人外周血单核细胞MCP 1的表达和分泌以及MMP 9的分泌 ,说明它具有抗炎作用 ,其抗炎作用可能与其改善PPARγ表达有关。     

过氧化物酶增殖物激活受体δ研究进展

过氧化物酶增殖物激活受体(PPARs)是配体激活转录因子,属于核受体超家族.自1990年PPARs被发现以来,其在物质代谢、组织细胞分化与疾病的相关性等方面的功能作用逐渐得到认识和重视.PPARs有3种亚型,分别为PPARα,PPARδ/β和PPARγ.随着PPARδ特异选择性激动剂的发现,PPARδ的生物学功能及其与各种疾病的关系渐渐成为研究热点.目前已经发现PPARδ主要控制脂肪组织和骨骼肌细胞的脂类代谢和能量平衡,并参与许多疾病的发生和发展过程.并且PPARδ作为治疗靶点,他的合成激动剂有望开发成为治疗代谢综合症的有效药物.     

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.     

Cytoprotective effect of tauroursodeoxycholate on hepatocyte apoptosis induced by peroxisome proliferator-activated receptor gamma ligand

Background and Aim:  Peroxisome proliferator-activated receptor gamma (PPARγ) ligands inhibit cell growth and induce apoptosis in various cancer cells. Bile acids are also known to cause hepatocyte apoptosis through nuclear receptor-mediated mechanisms. The aim of this study was to examine the effect of two different bile acid species on the inhibitory action of PPARγ in cell growth with paying attention to the role of the mitogen-activated protein kinase pathway as an underlying mechanism.
Methods:  Immortalized human hepatocytes (OUMS-29) and hepatoma cells (HepG2 and Huh7) were incubated with troglitazone (TGZ), a PPARγ ligand with or without pre-incubation of either hydrophobic glycochenodeoxycholate (GCDC) or hydrophilic tauroursodeoxycholate (TUDC).
Results:  TGZ induced cell apoptosis in all cell types, resulting in the reduction of cell viability. While pre-incubation with GCDC enhanced the apoptotic effects of TGZ, TUDC significantly attenuated it. Both bile acids enhanced p38 and c-Jun N-terminal kinase (JNK) phosphorylation in a similar way, whereas there was more drastic enhancement of extracellular signal-regulated kinase (ERK) 1/2 phosphorylation in the presence of TUDC compared to GCDC. In addition, ERK inhibitors suppressed the action of TUDC against apoptotic effect of TGZ.
Conclusion:  This study demonstrates that TUDC exhibits anti-apoptotic and cytoprotective effects against TGZ-induced cell apoptosis, presumably through the ERK signaling pathway. We speculate that the administration of TUDC might be one of the potential strategies for the hepatotoxicity caused by TGZ.     

Pioglitazone, a peroxisome proliferator-activated receptor gamma activator, ameliorates experimental autoimmune myocarditis by modulating Th1/Th2 balance

OBJECTIVES: The aim of this study is to investigate the effect of Peroxisome proliferator-activated receptor gamma (PPAR gamma) ligand on experimental autoimmune myocarditis (EAM). BACKGROUND: Rat EAM model resembles the giant cell myocarditis in human. Recent studies have suggested that Th1 cytokines are involved in the initiation and progression of EAM, whereas Th2 cytokines are associated with the remission. PPAR gamma, which is a member of nuclear hormone receptor superfamily, has been known to affect not only glucose homeostasis but also immune responses, by regulating the Th1/Th2 balance. METHODS: Lewis rats were immunized with cardiac myosin and divided into three groups: Group N, normal control rats (n = 16); Group E, EAM rats (n = 17); and Group P, EAM rats treated with a PPAR gamma activator pioglitazone (n = 20). RESULTS: Cardiac dysfunction and remodeling were inhibited in Group P compared to Group E. Heart weight/body weight ratio and the degree of inflammation and fibrosis were significantly lower in Group P than in Group E. The mRNA levels of macrophage inflammatory protein-1alpha (MIP-1alpha), which plays an important role in the recruitment of inflammatory cells in the early stage of EAM, were upregulated in the heart of Group E, but not in the heart of Group P. Furthermore, the treatment with pioglitazone decreased the expression levels of proinflamatory cytokine (TNF alpha and IL-1beta) genes and Th1 cytokine (IFN-gamma) genes, and increased the expression levels of Th2 cytokine (IL-4) gene. CONCLUSIONS: PPAR gamma ligands may have beneficial effects on myocarditis by inhibiting MIP-1alpha expression and modulating the Th1/Th2 balance.     

胰腺癌中过氧化物酶体增生激活受体和泛素-蛋白酶体系统的相关致癌机制

胰腺癌是人类癌症中最致命的种类之一。虽然肿瘤学在很多种癌症中取得了很大成就,但胰腺癌取得的进步很小,而且预后不容乐观。几个经常在胰腺癌中被定义并且变异的分子包括K-RAS、P53、P16和DPC4。过氧化物酶体增生激活受体(PPARy)在许多肿瘤中都起作用,而且在胰腺癌中过度表达,它跟NF-κB类似,具有肿瘤抑制作用和对抗一般蛋白质的致癌作用。调节通路是由泛素-蛋白酶体系统(UPS)完成并参与胰腺癌发生发展。本文将研究PPARy和核受体的UPS在胰腺致癌机制中的关系。     

PPAR-γ激动剂对急性坏死性胰腺炎大鼠肺损伤的作用

目的 探讨过氧化物酶体增殖物激活受体γ(PPAR-γ)激动剂罗格列酮对ANP大鼠肺损伤的作用及其机制.方法 雄性Wistar大鼠54只,按完全随机法分为假手术组(SO组)、ANP组、罗格列酮组.胆胰管逆行注射5%牛磺胆酸钠制备ANP模型.SO组、ANP组在造模前30 min股静脉注射10%DMSO(0.2 ml/100 g体重);罗格列酮组则注射等量10%DMSO溶解的罗格列酮(6 mg/kg体重).术后3 h、6 h、12 h分批剖杀,每个时间点6只.检测血清淀粉酶、肺组织髓过氧化物酶(MPO)、肺湿干重比、支气管肺泡灌洗液(BALF)蛋白含量.取胰头部胰腺组织和肺组织行病理学检查.RT-PCR检测肺组织TNF-α mRNA和ICAM-1 mRNA的表达.结果 ANP组血淀粉酶、肺MPO、湿干重比、BALF蛋白含量、胰腺及肺病理分值、肺脏TNF-α mRNA和ICAM-1 mRNA的表达水平均随时间延长而逐渐升高,12 h时分另0为(5353.0±728.2)U/L、(1.12±0.14)U/g、3.00±0.14、(0.438±0.056)g/L、11.17±0.93、8.17±0.75、0.57±0.03和1.53±0.08,均明显高于SO组(P<0.05或P<0.01).罗格列酮12 h组上述指标分别为(2847.4±841.0)U/L、(0.84±0.06)U/g、2.13±0.36、(0.283±0.078)g/L、7.75±0.27和4.33±0.82、0.26±0.04和0.84±0.02,均明显低于ANP 12 h组(P<0.05或P<0.01),但仍高于SO组(P<0.05或P<0.01).结论 罗格列酮对ANP大鼠胰腺及肺损伤具有一定程度保护作用,其机制可能与抑制肺组织TNF-α、ICAM-1 mRNA的表达有关.     

罗格列酮对非酒精性脂肪性肝炎大鼠环氧合酶-2的调节

目的 探讨罗格列酮在治疗非酒精性脂肪性肝炎(NASH)大鼠中对过氧化物酶体增殖物激活受体(PPARγ)、核因子(NF)-κB、环氧合酶(COX)-2的影响.方法 将30只SD大鼠均分为正常组、模型组和罗格列酮治疗组,除对照组外,其余两组予高脂连续饲养12周复制非酒精性脂肪性肝炎(NASH)模型.从第12周开始治疗组每天给予罗格列酮4 mg/kg灌胃8周.第20周末处死动物,收集血清和肝组织,检测肝功能、血脂、糖代谢、氧化还原指标.采用HE和Masson染色观察肝脏病理变化.ELISA法检测血清肿瘤坏死因子-α和前列腺素E2水平.免疫组化法观察肝组织PPARγ、NF-κB和COX-2表达,荧光定量PCR和Western印迹法检测肝COX-2基因和蛋白表达变化.结果 与模型组相比,治疗组脂肪变性、炎性反应和纤维化改善明显(P值均<0.05).同时模型组空腹血糖、血清胰岛素、胰岛素抵抗指数(HOMA-IRI)升高,血清和肝组织脂代谢紊乱,总胆固醇、三酰甘油、低密度脂蛋白胆固醇、游离脂肪酸(FFA)升高,高密度脂蛋白胆固醇下降.治疗组在罗格列酮治疗后上述指标均明显好转.与模型组相比,治疗组丙氨酸转氨酶和天冬氨酸转氨酶明显下降,血清和肝组织总抗氧化能力、超氧化物歧化酶、过氧化氢酶、谷胱甘肽过氧化物酶明显升高,丙二醛明显下降.免疫组化显示模型组肝PPARγ表达下降、NF-κB和COX-2表达升高.定量PCR和Western印迹法显示模型组肝COX-2表达(0.57±0.08和2.83±0.24)较正常组(0.38±0.03和1.00±0.03)升高(P值分别=0.000和0.004),治疗组COX-2基因和蛋白均明显下降(1.84±0.13和0.55±0.06,P值均<0.01).结论 罗格列酮可减轻氧化应激和胰岛素抵抗,可用于治疗NASH.其机制可能是通过激活PPARγ后抑制NF-κB和COX-2表达实现.     

Peroxisome proliferator-activated receptor γ agonist reduces the severity of post-ERCP pancreatitis in rats

AIM: To determine the effects of prophylactic peroxi-some proliferator-activated receptor (PPARgamma) agonist administration in an experimental model of post-endoscopic retrograde cholangiopancreatography (post-ERCP) acute pancreatitis. METHODS: Post-ERCP pancreatitis was induced in male Wistar rats by infusion of contrast medium into the pancreatic duct. In additional group, rosiglitazone, a PPARgamma agonist, was administered 1 h before infusion of contrast medium. Plasma and pancreas samples were obtained 6 h after the infusion. RESULTS: Infusion of contrast medium into the pan-creatic duct resulted in an inflammatory process characterized by increased lipase levels in plasma, and edema and myeloperoxidase activity (MPO) in pancreas. This result correlated with the activation of nuclear factor kappaB (NFkappaB) and the inducible NO synthase (iNOS) expression in pancreatic cells. Rosiglitazone reduced the increase in lipase and the level of edema and the increase in myeloperoxidase as well as the activation of NFkappaB and iNOS expression. CONCLUSION: A single oral dose of rosiglitazone, given 1 h before post-ERCP pancreatitis induction is effective in reducing the severity of the subsequent inflammatory process. The protective effect of rosiglitazone was associated with NFkappaB inhibition and the blockage of leukocyte infiltration in pancreas.