曲格列酮诱导人心肌细胞氧化应激和自噬的作用

目的研究曲格列酮的心肌细胞毒性特征,并从线粒体氧化应激和自噬角度探讨其潜在的毒作用机制。方法人源心肌细胞AC16给予不同浓度曲格列酮0~40μmol·L^-1孵育24 h。倒置显微镜观察细胞形态,CCK-8法检测细胞存活率,漏出法检测乳酸脱氢酶(LDH)释放量;荧光探针TMRM检测线粒体膜电位和CM-H2DCFDA检测全细胞活性氧的含量;Western印迹法检测微管相关蛋白Ⅱ/Ⅰ轻链3(LC3-Ⅱ/LC3-Ⅰ)比值和P62蛋白表达水平。结果与细胞对照组相比,曲格列酮可浓度依赖性地引起细胞质皱缩、细胞存活率下降(r=-0.928,P<0.05)和LDH释放量增加(r=0.746,P<0.05);曲格列酮10和20μmol·L^-1可明显降低细胞线粒体膜电位(P<0.05),增加全细胞活性氧含量(P<0.05);显著增加LC3-Ⅱ/LC3-Ⅰ比值,上调P62蛋白表达(P<0.05)。结论曲格列酮可引起心肌细胞损伤和线粒体功能障碍,其机制与线粒体氧化应激和自噬体降解受阻密切相关。

Troglitazone induces oxidative stress and autophagy in human cardiomyocytes

OBJECTIVE To investigate the effect of troglitazone-induced toxicity,and explore its mechanism related to mitochondrial oxidative stress and autophagy.METHODS AC16 cells were treated with different concentration of troglitazone 0-40μmol·L^-1 for 24 h.The morphological changes were observed under an inverted microscope,cell viability was examined by CCK-8 assay,whereas lactate dehydrogenase(LDH)leakage was estimated by assay kit.The mitochondrial membrane potential and intracellular reactive oxygen species(ROS)were detected by high content analysis using TMRM and CM-H2DCFDA fluorescent probes.The protein expressions of microtubule-associated protein Ⅰ/Ⅱ light chain 3(LC3-Ⅱ/LC3-Ⅰ)ration and P62 were detected by Western blotting.RESULTS Compared with cell control group,troglitazone induced morphological changes,reduction of cell viability(r=-0.928,P<0.05),and increase of LDH leakage(r=0.746,P<0.05)in a concentration-dependent manner.The mitochondrial membrane potential was decreased while intracellular ROS was increased in troglitazone 10 and 20μmol·L^-1 group(P<0.05).Troglitazone was found to significantly increase the ratio of LC3-Ⅱ/LC3-Ⅰ(P<0.05)and up-regulate P62 protein expressions(P<0.05).CONCLUSION Troglitazone can induce cytotoxicity and mitochondrial dysfunction,which is possibly related to mitochondrial oxidative stress and inhibited autophagosome degradation in human cardiomyocytes.