缺氧对肥大心肌细胞凋亡和缝隙连接蛋白43表达的影响

目的探讨缺氧对正常心肌细胞和肥大心肌细胞缝隙连接蛋白43(Cx43)表达的影响。方法将培养的乳鼠心肌细胞或诱导肥大后的心肌细胞分别缺氧24 h,并以Hoechst33258染色法检测缺氧对心肌细胞凋亡的影响,Western blot和免疫荧光法检测Cx43的表达。结果培养的心肌细胞经血管紧张素Ⅱ诱导48 h后出现肥大,肥大心肌细胞缺氧24 h比正常心肌细胞出现更明显的凋亡,缺氧明显下调心肌细胞Cx43的表达,而肥大心肌细胞Cx43的表达下调更为明显。结论缺氧导致肥大心肌细胞Cx43的表达显著下调,细胞凋亡更明显,可能与缺氧时肥大心肌的电生理重构和恶性心律失常的产生机制有关。

Effects of Hypoxia on Connexin 43 Expression and Apoptosis of Hypertrophic Cardiomyocyte

Aim To investigate the effects of hypoxia on the expression of Cx43 and apoptosis in hypertrophic rat cardiomyocytes.Methods Cardiomyocytes from newly born rats were cultured after digested in trypsin.The apoptosis rate of cardiomyocytes induced by hypoxia was evaluated by a modified Hoechst33258 fluorescent staining method.The expression of the Cx43 protein were detected by Western blot and fluorescent staining method.Results Compared with the control group,the apoptosis rate of hypertrophic cardiomyocytes induced by 24 h hypoxia was increased(15.42%±1.62%vs 2.56%±0.48%).The expression of Cx43 protein of hypertrophic cardiomyocytes was obviously decreased in comparison with the control group.Hypoxia could significantly down-regulate the Cx43 expression in hypertrophic cardiomyocytes than that of the normal cardiomyocytes(P<0.01).Conclusions Hypoxia can significantly increase the apoptosis rate and down-regulate the Cx43 expression in hypertrophic cardiomyocytes.These may be involved in the mechanisms of electrophysiology remodeling and malignant arrhythmia of hypertrophia myocardium induced by hypoxia.