过氧化物酶增生物激活受体γ激动剂对肝星状细胞α1(I)胶原表达的影响

Effects of PPARγ Agonist on the Expression of Procollagen α1(Ⅰ) in Hepatic Stellate Cells

目的观察过氧化物酶增生物激活受体γ(PPARγ)激动剂15d-PGJ2对肝星状细胞株(HSC-T6)前胶原α1(Ⅰ)表达的影响,以进一步探讨PPARγ在肝纤维化进程中的作用机制。方法体外培养HSC-T6细胞,取对数生长期的细胞分为空白对照组、TGFβ-对照组和15d-PGJ2处理组,TGF-β对照组和15d-PGJ2处理组均给予TGF-β因子(终浓度3 ng/ml)共孵育6 h,15d-PGJ2处理组再用1、2、3μmol/L的PPARγ激动剂15d-PGJ2作用24 h。应用RT-PCR、Westernblot方法观察分析各组间肝星状细胞PPARγ、前胶原α1(Ⅰ)基因表达的变化。结果15d-PGJ2能够显著上调PPARγmRNA和蛋白的表达水平,15d-PGJ2处理组的相对吸光度值较空白对照明显升高(P<0.05),而TGFβ-对照组与空白对照组差异无显著性意义(P>0.05)。在TGFβ-刺激下,TGF-β对照组前胶原α1(Ⅰ)mRNA水平均升高,同空白对照组相比差异有显著性意义(P<0.05);15d-PGJ2处理组细胞前胶原α1(Ⅰ)mRNA水平与空白对照组相比差异无显著性意义(P>0.05),但与TGFβ-对照组相比,其表达明显受抑制(P<0.05)。结论PPARγ激动剂15d-PGJ2能够通过上调PPARγ表达而抑制前胶原α1(Ⅰ)转录,提示PPARγ可抑制肝纤维化的发生发展。

Objective To investigate the effects of peroxisome proliferator activated receptor γ（PPARγ） agonist 15d-PGJ2 on collagen synthesis in hepatic stellate cells （ HSCs）, so as to provide experimental evidence for regulating collagen metabolism of HSCs. Methods Rat HSC-T6 cells were cultured in vitro, and were divided into blank control group, TGF-β （final concentration 3 ng/ml） control group and the groups treated with different concentrations of 15d-PGJ2（1, 2, 3;μmo/L）. The expression of procollagen α1（Ⅰ） gene and PPARy was detected by RT-PCR and Western blot. Results 15d-PGJ2 could significantly up-regulate the expression of PPARy mRNA and protein. Compared with blank control group, the values of relative absorbance in the groups treated with 15d-PGJ2 were obviously increased （P〈0.05）, whereas there was no difference between blank control group and TGF-β control group（P〈0.05）. After stimulated with TGF-β, the procollagen α1（Ⅰ） mRNA in TGF-β control group and the groups treated with 15d-PGJ2 were all up-regulated, but there was significant difference in the expression of the procollagen α1（Ⅰ） mRNA between TGF-β control group and the groups treated with 15d-PGJ2. The procollagen α1（Ⅰ） mRNA in the groups treated with 15d-PGJ2 was significantly inhibited as compared with TGF-β control group （P〈0.05）, but there was no significant difference between blank control group and the groups treated with 15d-PGJ2 （P〉0.05）. Conclusion 15d-PGJ2 could inhibit the transcription of procollagen α1（Ⅰ） gene by up-regulating the expression of PPARγ in HSC-T6, suggesting PPARy could inhibit the development of liver fibrosis.