miR-21通过抑制PTEN/PI3K/AKT信号通路减轻小鼠肝细胞缺氧/复氧损伤

The miR-21 attenuates hepatocyte hypoxia/reoxygenation injury via inhibiting PTEN/PI3K/AKT signaling pathway

目的探讨体外实验中miR-21对C57BL/6J小鼠原代肝细胞缺氧/复氧(H/R)损伤的影响及其可能的分子机制。方法建立体外原代培养肝细胞H/R模型,采用实时定量PCR检测miR-21的表达;Western blot法检测肝细胞中第10号染色体缺失的磷酸酶及张力蛋白同源基因(PTEN)、磷酸化的蛋白激酶B(p-AKT)、Bcl-2、Bax的蛋白表达水平;流式细胞术检测肝细胞凋亡。结果原代培养肝细胞在H/R处理后miR-21表达下调;而外源性miR-21模拟物处理的肝细胞经H/R后PTEN表达降低、p-AKT表达升高、Bcl-2表达水平及Bcl-2/Bax比值升高,肝细胞凋亡减少,而抑制AKT磷酸化可导致肝细胞Bcl-2表达水平及Bcl-2/Bax比值降低,肝细胞凋亡增加。结论 miR-21可通过抑制PTEN/PI3K/AKT信号通路减轻H/R导致的肝细胞凋亡,减轻H/R过程中肝细胞的损伤。

Objective To study the effect of microRNA-21 （ miR-21 ） on hypoxia/reoxygenation （ H/R）-treated primary hepatocytes from C57BL/6J mice and analyze its possible molecular mechanism. Methods The H/R model of primary hepatocytes was established and the expression of miR-21 was detected by the quantitative real-time PCR. Western blotting was used to detect protein expression levels of phosphatase and tension homology deleted on chromosome 10 （ PTEN）, phosphorylated AKT （ p-AKT）, Bcl-2 and Bax. Flow cytometry was performed to observe the hepatocyte apoptosis. Results The expression of miR-21 in primary hepatocytes decreased after H/R injury. After transfected with exogenous miR-21 mimics, the expression of PTEN decreased, while the expressions of p-AKT and Bcl-2 and the ratio of Bcl-2/Bax increased in hepatocytes; the apoptotic level of hepatocytes was downregulated. The inhibition of AKT phosphorylation could downregulate the expression of Bcl-2 and the ratio of Bcl-2/Bax, and upregulate the level of hepatocyte apoptosis. Conclusion The miR-21 can alleviate the hepatocyte apoptosis by inhibiting the PTEN/PI3K/AKT signaling pathway in the process of H/R.