急性心肌梗死患者抗心肌肌球蛋白重链抗体诱导心肌细胞凋亡

摘要

目的:探讨抗心肌肌球蛋白重链抗体(AMHCA)诱导心肌细胞凋亡的作用及其机制.方法:从急性心肌梗死患者血清中提取AMHCA,研究其对成年大鼠心肌细胞凋亡的影响.DNA末端标记膜联蛋白-V/PI复染色法观察和测量心肌细胞凋亡.分别用免疫印迹、膜片钳和激光共聚焦法检测凋亡相关蛋白P53和Bcl-2以及第二信使钙离子的表达和浓度.结果:AMHCA诱导的心肌细胞凋亡具有剂量依赖性.在此过程中,促凋亡的核蛋白P53促进心肌细胞凋亡,而抑凋亡的胞质蛋白Bcl-2 抑制心肌细胞凋亡.同时,胞内钙离子浓度升高,而L型钙通道则没有影响.结论:急性心肌梗死患者体内的AMHCA可能是一种新的起动因子,可诱导心肌细胞凋亡.%AIM : To study the effect of human anti - cardiac myosin heavy chain antibodies( AMHCA ) on rat cardiomyocyte apoptosis.METHODS: Rat cardiomyocytes were isolated by the method of enzymolysis.Apoptosis of the cardiomyocytes was observed and measured hy DNA end labelling and Annexin - V/PI double - staining assay.The proteins levels of apoptosis related P53 and Bcl - 2 and the second messenger calcium were measured by Western hlotting,patch clamp and confocal calcium imaging, respectively.RESULTS : AMHCA was able to induce cardiomyocyte apoptosis in a dose dependent manner.In the presence of AMHCA, apoptosis - accelerating nucleoprotein P53 promoted myocardial apoptosis, while apoptosis - inhibiting cytoplasmic protein Bcl - 2 inhibited myocardial apoptosis.Meanwhile , the concentration of cytoplasmic calcium was elevated.No effect of AMHCA on L - type calcium currents was observed.CONCLUSION : As a novel triggering factor, AMHCA isolated from the patients with AMI induces cardiomyocyte apoptosis.