姜黄素通过激活过氧化物酶体增殖子活化受体γ诱导肝星状细胞凋亡

Curcumin induces apoptosis of hepatic stellate cells by activating peroxisome proliferator-activated receptor γ signal

目的研究姜黄素对肝星状细胞(HSC)凋亡的作用,以及与过氧化物酶体增殖子活化受体γ(PPARγ)信号之间的关系。方法肝脏原位灌流酶消化、Nycodenz密度梯度离心方法分离培养大鼠HSC,传代培养并使用药物处理。Ho-echst33258染色检测细胞凋亡,免疫荧光染色检测PPARγ的细胞内分布。收集裂解细胞分别抽提RNA、总蛋白和核蛋白,半定量RT-PCR和Westernblot方法检测目标基因和蛋白表达水平。结果活化HSC几乎没有凋亡发生,而姜黄素处理诱导了HSC凋亡,促进了HSC中PPARγ的核转位和(或)重分布。姜黄素在转录和翻译水平,增强HSC胞核PPARγ表达,抑制了抗凋亡因子Bcl-2的表达,促进了促凋亡因子Bax表达;这些作用能够被PPARγ阻断剂所拮抗。结论姜黄素促进过氧化物酶体增殖因子活化受体γ表达和核转位/重分布,诱导肝星状细胞凋亡。

Aim To study the effect of Curcumin on the apoptosis of hepatic stellate cells （ HSC）, and the correlation between the effect and peroxisome proliferator-activated receptor γ（PPARγ） signal. Methods The HSC was isolated from normal SD rats through in situ perfusion of liver with protease E and density-gradient centrifugation with Nycodenz. The subcuhured cells were treated with corresponding compounds. Cell apoptosis was detected by Hoechst 33258 staining. PPARγsubcellular distribution was detected by immunofluorescent staining. Total RNA, total protein and nuclear protein were extracted respectively, target gene and protein levels were determined by semi-quantitative RT-PCR or Western blot. Results There was nearly no apoptosis in activated HSC. Curcumin treatment induced the apoptosis of HSC, enhancing PPARγ nuclear translocation/redistribution. At the transcription and translation level, curcumin upregulated nuclear PPARγ expression, inhibited anti-apoptotic Bcl-2 expression, and promoted pro-apoptotic Bax expression; but all these effects could be reversed by PPARγ antagonist GW9662. Conclusions Curcumin induces HSC apoptosis by enhancing PPARγ expression and nuclear translocation/redistribution.