低氧诱导因子-1α在喹啉酸诱导的PC12细胞损伤中的作用

摘要

目的：探讨低氧诱导因子-1（hypoxia inducible factor-1α，HIF-1α）在喹啉酸诱导大鼠肾上腺嗜铬细胞瘤 PC12细胞损伤中的作用。方法用不同浓度的喹啉酸（2．5，5和10 mmol·L －1）处理 PC12细胞24 h 诱导细胞损伤，采用噻唑蓝还原法和乳酸脱氢酶漏出率检测法测定细胞损伤程度，采用丙二醛和超氧化物歧化酶试剂盒检测细胞内氧自由基水平， Hoechst 33258单荧光染色法观察细胞凋亡，免疫荧光染色法检测 HIF-1α在细胞内的表达，免疫印迹法检测细胞 HIF-1α、蛋白激酶 B （Akt）、磷酸化 Akt （phosphorylated-Akt，p-Akt）、淋巴瘤／白血病-2（B cell lymphoma／lewkmia-2，Bcl-2）和 Bcl-2相关 X 蛋白（Bcl-2 associated X protein，Bax）的表达。结果喹啉酸可剂量依赖性地诱导 PC12细胞损伤，导致细胞内氧自由基增多和细胞凋亡。同时，喹啉酸可使PC12细胞 HIF-1α表达上调并聚集于核内；p-Akt 表达增加， Bax／Bcl-2表达比例增加。结论HIF-1α和 Akt 介导了喹啉酸诱导 PC12的细胞凋亡；此外，氧化应激过程也可能参与了细胞损伤。%Aim To investigate the role of HIF-1 αin PC1 2 cell injury induced by quinolinic acid.Methods PC1 2 cells were treated with quinolinic acid at the do-ses of 2.5,5 and 1 0 mmol·L -1 ,the cell viability was determined by MTT reduction assay and LDH as-say,the intracellular levels of oxygen species was measured by assessing SOD and MDA levels,cell ap-optosis was determined by Hoechst 33258 staining,the intracellular distribution of HIF-1 αwas examined by HIF-1 αimmunostaining,and the expressions of HIF-1 α,Akt,p-Akt,Bcl-2 and Bax were determined by im-munoblotting analysis.Results Quinolinic acid in-duced cell injury in PC1 2 cells in a dose-dependent manner,and potentiated oxygen radical production and cell apoptosis.In addition,quinolinic acid enhanced HIF-1 αexpression and accumulation in nuclei.The p-Akt expression and Bax/Bcl-2 ratio was increased by quinolinc acid in PC1 2 cells.Conclusions HIF-1 αand Akt mediate qunolinc acid-induced cell apoptosis in PC1 2 cells.And cellular oxidative stress may con-tribute to the injury as well.