摘要
目的研究过氧化物酶体增殖物激活受体γ(PPARγ)激动剂阻断转化生长因子(TGF)β1致肝纤维化作用的机制,探讨其抗肝纤维化的潜在作用。方法体外培养肝星状细胞株HSC-T6。观察PPARγ配体15d-PGJ2及其激动剂曲格列酮和齐格列酮对TGFβ1诱导的纤维连接蛋白(FN)表达的影响。利用Western印迹技术观察PPARγ激动剂对TGFβ1诱导的FN和Smad蛋白表达的影响。结果 (1)与1ng/mlTGFβ1组比较,5ng/ml TGFβ1组表达量增加了3.7倍(P<0.01),5ng/mlTGFβ1刺激24时较刺激前增加了2.5倍(P<0.01),TGFβ1诱导表达呈一定范围内的剂量(0～5/)和时间(0～24h)依赖效应。(2)与5ng/mlTGFβ1组比较,10μl15d-PGJ2、曲格列酮和齐格列酮预处理组FNmRNA表达量分别降低37.4%4、1.1%和21.7%,FN蛋白表达量分别降低24.7%、37.1%和27.1%。(3)5ng/mlTGFβ1以时间(0～2)依赖方式诱导P-Smad 2/3蛋白表达量增加,作用1h达到高峰;5ng/mlTGFβ组P-Smad2/3蛋白表达量较对照组和2ng/mlTGFβ1组分别增加3.42倍和0.98倍。(4)15d-PGJ2、曲格列酮和齐格列酮预处理组P-Smad2/3蛋白表达量与5ng/mlTGFβ1组比较分别降低61.1%、53.4%和59.4%3,种药物干预组之间P-Smad2/3蛋白表达量比较差异无统计学意义,各组Smad2和Smad3蛋白表达量无显著变化。结论 PPARγ激动剂可以抑制TGFβ1诱导的肝星状细胞株成纤维细胞FN合成,其机制可能与阻断TGFβ1/Smad信号途径有关,提示PPARγ激动剂具有抗肝纤维化的潜在作用,可能成为肝纤维化治疗新手段之一。
Objective： To study the effects of peroxisome proliferators-activated receptorγ（PPARγ） agonists on transforming growth factor（TGF）-β1-induced fibrotic responses in liver fibrosis,so as to investigate its effects in prevention of liver fibrosis.Methods：Hepatic stellate cell（HSC） were cultured and divided into groups.In Group 1 TGFβ1 of the concentrations of 0,1,2,5,and 10ng/ml were added and co-cultured for 24h.In Group 2 TGFβ1 of the concentration of 5ng/ml was added and co-cultured for 0,6,12,and 24h respectively.Groups 3,4,and 5 were pretreated with 10μmol/L15d-PGJ2,PPARγ ligand,10μmol/L troglitazone,agonist of and 10μmol/L ciglitazone,both PPARγ agonists,respectively for 2h,then treated with 5ng/mlTGFβ1.A blank control group was set up.The cultured cells were collected.RT-PCR was used to detect the mRNA expression of TGF-β1-induedfibronectin（FN）.Western blotting was used to detect the expression of TGF-β1-induced FN,Smad,and phosphorylated Smad（p-Smad） proteins.Results： TGF-β1 enhanced the FN mRNA expression in a dose-and time-dependent manner.The FN mRNA expression of the 5ng/mlTGF-β1 group was 3.7 times higher than that of the control group（P0.05）.The FN mRNA expressions of the 15d-PGJ2,troglitazone-,and ciglitazone-pretreated groups were lower than those of the 5ng/ml TGF-β1 group by 37.4%,41.1%,and 21.7% respectively（all P0.05）.The FN expression of that was lower than that of the 5ng/ml TGF-β1 group by 24.7%,37.1% and 27.1% respectively（allP0.05）.The p-Smad2/3 protein expression levels of the TGF-β1 group began to increase 15 minutes after stimulation,increased in a time-dependent manner,peaked 1 hour after,and began to decrease 2 hours later.However,the levels of protein expression of total Smad2 and Smad3 did not change significantly in all the groups.Both 2ng/ml TGFβ1 and 5 ng/mlTGFβ1 significantly induced the increase of protein expression of p-Smad2/3（allP0.05）.The levels of protein expression of p-Smad2 and p-Smad3 of the 5ng/ml TGFβ1 group were 3.42 and 0.98 times higher than those of the 2 ng/mlTGFβ1（both P 0.05）.The levels of protein expression of p-Smad2/3 of the 15d-PGJ2,troglitazone-,and ciglitazone-pretreated groups were all significantly lower than those of the 5 ng/mlTGFβ1 group by 61.1%,53.4%,and 59.4%（allP0.05）.However,there was no significant difference among different drug-treated groups（allP0.05）.Conclusion：Through abrogating TGF-β1/Smads signaling pathway,PPARγ agonists inhibitTGF-β1-induced HSC and may play a potential role in preventing liver fibrosis as a novel approach to prevent the progress of liver fibrosis.
出处
《泰山医学院学报》
CAS
2011年第6期413-416,共4页
Journal of Taishan Medical College
