醛固酮诱导MIN6细胞凋亡及作用机制研究  

Aldosterone-induced apoptosis of MIN6 cells and its mechanism

作　　者：潘瑜[1] 刘晓莉[1] 束金莲[1] 张霞[1] 金惠敏[1] 

机构地区：[1]上海交通大学医学院附属第三人民医院肾内科,上海201900

出　　处：《上海交通大学学报（医学版）》2012年第3期288-292,共5页Journal of Shanghai Jiao tong University:Medical Science

基　　金：上海市科委基金(08411962000);上海市教委基金(10YZ35);上海宝山区科委基金(09-E-2)~~

摘　　要：目的探讨醛固酮对小鼠胰岛B细胞株MIN6细胞凋亡的影响及可能的作用机制。方法体外培养的小鼠胰岛B细胞株MIN6分为对照组(加入无血清的DMEM培养基)、醛固酮组(加入10、100、1 000 nmol/L醛固酮进行干预)和醛固酮+拮抗剂组(以100 nmol/L醛固酮和100 nmol/L醛固酮拮抗剂螺内酯共同干预)。采用MTT法检测细胞活性;放射免疫分析法检测葡萄糖刺激的胰岛素分泌(GSIS);流式细胞术结合FITC-Annexin V/PI荧光染色检测细胞凋亡;ELISA法检测细胞培养上清液中Caspas-3活性;Western blotting法检测凋亡相关蛋白细胞色素C(Cyt-C)、Bcl-2、Bax和磷酸化蛋白激酶C(p-Akt)的表达。结果MIN6细胞增殖活性随醛固酮干预浓度的升高而下降,呈现浓度依赖性。在生理糖浓度(5.6 mmol/L)和高葡萄糖浓度(28 mmol/L)环境中,醛固酮组的GSIS均显著低于与对照组(P<0.01),而醛固酮+拮抗剂组GSIS显著高于醛固酮组(P<0.01)。醛固酮组细胞凋亡率显著高于对照组(P<0.01),而醛固酮+拮抗剂组细胞凋亡率显著低于醛固酮组(P<0.01)。与对照组比较,醛固酮组Caspase-3活性明显升高,Cyt-C表达上调,Bcl-2/Bax下降,p-Akt表达下调(均P<0.01);而醛固酮+拮抗剂组对醛固酮组的Caspase-3活性升高及相关蛋白表达异常具有明显抑制作用。结论醛固酮具有促进MIN6细胞凋亡的作用,其作用机制可能与Cyt-C、Bcl-2、Bax和Akt介导的线粒体信号途径有关。Objective To investigate the effects of aldosterone on apoptosis of murine pancreatic islets B cell line MIN6,and explore its possible mechanism.Methods Murine pancreatic islets B cell line MIN6 cultured in vitro was divided into control group（treated with serum-free DMEM culture medium）,aldosterone group（treated with 10,100 or 1 000 nmol/L aldosterone） and aldosterone＋aldosterone antagonist group（treated with 100 nmol/L aldosterone and 100 nmol/L aldactone）.Cell viability was determined by MTT assay,glucose-stimulated insulin secretion（GSIS） was measured by radioimmunoassay,cell apoptosis was detected by flow cytometry in combination with FITC-Annexin V/PI fluorescein staining,Caspase-3 activity in supernatant of culture fluid was determined by ELISA,and the expression of apoptosis-related proteins of cytochrome C（Cyt-C）,Bcl-2,Bax and phosphorylated protein kinase C（p-Akt） was detected by Western blotting.Results The viability of MIN6 cells decreased with the increase of concentrations of aldosterone,with a concentration-dependent manner.Under physical glucose concentration（5.6 mmol/L） and high glucose concentration（28 mmol/L） environment,GSIS of aldosterone group was significantly lower than that of control group（P0.01）,and GSIS of aldosterone＋aldosterone antagonist group was significantly higher than that of aldosterone group（P0.01）.The cell apoptosis ratio of aldosterone group was significantly higher than that of control group（P0.01）,and the cell apoptosis ratio of aldosterone＋aldosterone antagonist group was significantly lower than that of aldosterone group（P0.01）.Compared with control group,the Caspase-3 activity and expression of Cyt-C were significantly higher,and Bcl-2/Bax and the expression of p-Akt were significantly lower（P0.01 for all）,while aldosterone antagonist significantly inhibited aldosterone-mediated Caspase-3 activity increase and abnormal expression of related proteins.Conclusion Aldosterone enhances apoptosis of MIN6 cells,which m

关 键 词：醛固酮 胰岛B细胞 细胞凋亡 蛋白激酶C 

分 类 号：R363[医药卫生—病理学]