PACE4对异丙肾上腺素诱导的心肌细胞凋亡的影响及其机制  

Effect of PACE4 on the Apoptosis in Isoprenaline induced Cardiomyocyte and Its Mechanism

作　　者：王安杏 梁泽明[1] 张会军[1] 徐楷[1] 陈入菲 

机构地区：[1]宝鸡市中医医院心血管二科,陕西宝鸡721001

出　　处：《现代生物医学进展》2016年第31期6042-6046,共5页Progress in Modern Biomedicine

摘　　要：目的:研究前体蛋白转化酶枯草溶菌素(PACE4)对异丙肾上腺素(ISO)诱导的心肌细胞凋亡的作用及其可能的作用机制。方法:构建pFLAG-PACE4重组表达载体并转染H9c2心肌细胞。将心肌细胞分为四组:正常对照组(无任何干预因素)、ISO组(10μmol/L ISO)、ISO+pFLAG组(空载质粒pFLAG转染+10μmol/LISO)、ISO+pFLAG-PACE4组(pFLAG-PACE4重组表达质粒转染+10μmol/LISO)。采用AnnexinV-FITC/PI双染法测定心肌细胞凋亡率;蛋白免疫印迹法检测活性半胱氨酸蛋白酶(caspase)-3、caspase-12、钙网蛋白、葡萄糖调节蛋白78(GRP78)、CCAAT/增强子结合蛋白同源蛋白(CHOP)、活化转录因子4(ATF4)和PERK的表达以及真核起始因子2α(eIF2α)的磷酸化水平。结果:与正常对照组相比,ISO组中PACE4表达水平明显降低,而转染pFLAG-PACE4质粒后,其表达水平显著增加。PACE4过表达可以显著抑制ISO诱导的细胞凋亡和caspase-3以及caspase-12的蛋白表达。ISO处理显著增加内质网应激分子钙网蛋白、GRP78和CHOP的表达,而PACE4过表达则可以抑制这些蛋白的表达。ISO诱导的PERK、eIF2α和ATF4的表达可以显著被PACE4过表达抑制。结论:PACE4过表达可以抑制ISO诱导的H9c2心肌细胞凋亡,其机制可能与PERK信号通路介导的内质网应激反应有关。Objective： To investigate the effect of paired basic amino acid-cleaving enzyme 4（PACE4） on the apoptosis in H9c2 cardiomyocyte induced by isoprenaline（ISO） and the underlying mechanism. Methods： The recombinant expression vector pFLAG-PACE4 was established and transfected into the cardiomyocytes. Then cardiomyocytes were divided into four groups： control group（without treatment）, ISO group（10 μmol/L ISO）, ISO＋pFLAG group（pFLAG empty vector＋10 μmol/L ISO）, ISO＋pFLAG-PACE4 group（pFLAG-PACE4＋10 μmol/L ISO）. Cell apoptosis was analyzed by Annexin V-FITC/PI method. Protein levels of caspase-3, caspase-12, calreticulin, glucose regulated protein 78 k Da（GRP78）, CCAAT/enhancer binding protein homologous protein（CHOP） and activating transcription factors 4（ATF4） were detected by western blot. Meanwhile, the phosphorylated protein levels of PERK and eukaryotic initiation factor 2α（eIF2α） were measured by Western blot. Results： Compared with the control group, the expression of PACE4 was significantly decreased by ISO treatment which was markedly increased after pFLAG-PACE4 transfection. PACE4 overexpression significantly attenuated cell apoptosis and the protein expression of caspase-3 and caspase-12 induced by ISO treatment.ISO significantly induced the protein expression of ERS markers including calreticulin, GRP78 and CHOP which was markedly decreased by PACE4 overexpression. Furthermore, the increased protein expression of PERK, eIF2α and ATF4 was also repressed by PACE4 overexpression. Conclusion： PACE4 overexpression could alleviate ISO-induced apoptosis in H9C2 cardiomyocyte and the underlying mechanism might be associated with the inhibition of PERK signaling pathway-mediated endoplasmic reticulum stress.

关 键 词：PACE4 心肌细胞 凋亡 内质网应激 

分 类 号：R-33[医药卫生] R54