奥曲肽对人肝星状细胞凋亡及Bcl-2／Bax表达的影响

摘要

Objective To investigate the effects of octreotide on the apoptosis of human hepatic stellate cells (HSCs) and expression of Bcl-2/Bax in HSCs,and to reveal the mechanism underlying octreotide against hepatic fibrosis. Methods HSCs lines (HSC-LX2) were incubated with different concentrations of octreotide for 24 and 48 hours. Cell apoptosis was evaluated by Fitc-tunel fluorescence staining. Bcl-2 and Bax protein exoression in HSC-LX2 was detected by immunocytochemistry. Meanwhile, Bcl-2 protein of HSC-LX2 were detected by Western blot assay. Results Octreotide could promote the apoptosis of HSC-LX2, and the apoptosis rate was significantly increased with the concentration of octreotide(P < 0.05). The HSC-LX2 were incubated with the same concentration of octreotide for 24 and 48 hours, the cell apoptosis rate of 48-hour octreotide treatment was significantly higher than that of 24-hour octreotide treatment (P < 0.05). The immunocytochemistry result indicated that octreotide could significantly decrease Bcl-2 expression and increase Bax expression in HSC-LX2 (P<0.05); Western blot assay showed that octreotide could also significantly inhibit Bcl-2 expression in HSC-LX2 (P<0.05). Conclusions Octreotide could induce the apoptosis of HSCs in a dose-and time-dependent manner, the mechanism of octreotide inducing HSCs apoptosis might be associated with down-regulation of Bcl-2 and upregulation of Bax in HSC.%目的：观察奥曲肽对活化人肝星状细胞凋亡和凋亡相关蛋白Bcl-2／Bax 表达的影响，探讨奥曲肽抗肝纤维化可能的作用机制。方法：不同浓度的奥曲肽作用于传代的人肝星状细胞株（HSC-LX2）24 h、48 h后，应用FITC-TUNEL检测各组细胞凋亡，应用免疫细胞化学法检测HSC-LX2中Bcl-2、Bax蛋白表达，应用Western-blot法检测HSC-LX2中Bcl-2蛋白表达。结果：奥曲肽可促进HSC-LX2细胞调亡，细胞凋亡率随奥曲肽浓度增加而增高（P ＜0．05）；与24 h比较，相同浓度奥曲肽作用于HSC-LX248 h细胞凋亡率均明显增高（P ＜0．05）；免疫细胞化学结果显示：与对照组相比，奥曲肽明显降低HSC-LX2中Bcl-2蛋白表达，而增加Bax蛋白表达（P ＜0．05）；Western-blot结果表明：与对照组相比，奥曲肽可明显降低HSC-LX2中Bcl-2蛋白表达（P ＜0．05）。结论：奥曲肽可呈剂量和时间依赖性促进人肝星状细胞凋亡，其机制可能与奥曲肽诱发人肝星状细胞Bcl-2蛋白表达下调，Bax蛋白表达上调有关。