转化生长因子-β1在多柔比星致大鼠心肌细胞凋亡中的促进作用

目的:探讨转化生长因子-β1(TGF-β1)在多柔比星诱导大鼠心肌细胞凋亡中的作用。方法:取出生1～2d的SD大鼠心肌细胞进行体外分离及纯化,用α-横纹肌肌动蛋白(α-SA)免疫化学染色法鉴定细胞纯度。将培养第3天的心肌细胞随机分为对照组和不同浓度(0.5,1,2μmol/L)多柔比星处理组,同时对各浓度组的不同时间点(4,12,24,48,72 h)进行检测。用MTT法检测心肌细胞存活率,流式细胞术AnnexinⅤ/PI双染法检测心肌细胞凋亡率,ELISA法检测心肌细胞上清TGF-β1蛋白浓度。结果:原代分离培养第3天的心肌细胞纯度可达90%。多柔比星在0.5～2μmol/L浓度范围内,随着处理时间延长,心肌细胞存活率下降,呈剂量和时间依赖性;2μmol/L多柔比星可诱导心肌细胞凋亡,在4～48 h内细胞凋亡率不断增加,且心肌细胞TGF-β1蛋白表达量也逐渐增加,与凋亡率呈正相关。结论:TGF-β1可能在多柔比星诱导的大鼠心肌细胞凋亡中起促进作用。

Effect of transforming growth factor-beta1 on the apoptosis of rat cardiomyocytes induced by doxorubicin

Objective: To investigate the effect of TGF-β1 on the apoptosis of cardiomyocytes induced by doxorubicin(DOX).Methods: The cardiomyocytes isolated from 1~2 d SD rats were cultured in DMEM-F12 medium.The purify of cardiomyocytes was evaluated by immunocytochemical staining with α-sarcomericactin.The third-day cultured cardiomyocytes were randomly divided into control group and DOX groups.The cardiomyocytes of DOX groups were treated by different concertrations of DOX(0.5,1,2 μmol/L) for different times(4,12,24,48,72 h).The survival rate of cardiomyocytes was evaluated by MTT.The apoptosis rate was determined by flow cytometry(FCM).The expression of TGF-β1 in the cardiomyocytes was detected by ELISA.Results: The purify of the third day-cultured cardiomyocytes was above 90%.In a certain range of concertration(0.5~2 μmol/L),DOX could inhibit the growth of cardiomyocytes in a dose and time manner.2 μmol/L DOX could significantly induce the apoptosis of cardiomyocytes.During the time point 4 h to 48 h,the apoptosis rate was increased,while the expression of TGF-β1wasalso increased and positively correlated with the former.Conclusion: The increasing expression of TGF-β1 might contribute to the apoptosis of rat cardiomyocytes induced by doxorubicin.