内质网应激相关蛋白1过表达对缺氧/复氧诱导的H9c2心肌细胞凋亡的影响

目的 研究内质网应激相关蛋白1(SERP1)过表达对缺氧/复氧(H/R)诱导的大鼠胚胎H9c2心肌细胞凋亡的影响.方法 2018年1—12月将中国科学院上海细胞库大鼠H9c2心肌细胞系建立H/R损伤大鼠心肌细胞模型,采用pCMV6质粒为载体构建内质pCMV6-网应激相关蛋白1(pCMV6-SERP1)过表达重组质粒,分...

Effect of SERP1 overexpression on hypoxia/reoxygenation-induced apoptosis of H9c2 cardiomyocytes

Objective To study the effect of endoplasmic reticulum stress-related protein 1 (SERP1) overexpression on the apoptosis of rat embryonic H9c2 cardiomyocytes induced by hypoxia/reoxygenation (H/R).Methods The rat cardiomyocyte model of H/R injury was established by using the rat H9c2 cardiomyocyte cell line of the Shanghai cell bank of the Chinese Academy of Sciences fromJanuary 2018 to December 2018. The overexpression recombinant plasmid pCMV6-stress-related protein 1 (pCMV6-SERP1) was constructed using pCMV6 plasmid as vector. H9c2 myocardial cells were assigned into normal control group (NC group), H/R injury (hypoxia 4h/reoxygenation 4h) H9c2 myocardial cells were in H/R group, the empty plasmid of pCMV6 transfected by H/R injured H9c2cardiomyocytes was (H/R+pCMV6) group, and the overexpression recombinant plasmid of pCMV6-SERP1 was transfected into H9c2 myocardial cells injured by H/R (H/R+pCMV6-SERP1) group. The viability of H9c2 myocardial cells was measured by MTT assay, Annexin V-FITC/PI double staining technique was used to detect the apoptotic rate of H9c2 myocardial cells in each group, and real-time quantitative PCR (RT-qPCR) and immunoblotting (WB) were used to detect the expressions of SERP1 and apoptosis-related proteins in each group. Results Compared with NC group [(1.06±0.21), (0.41±0.07)], the expressions of stress-related protein 1 microRNA(SERP1 mRNA) [(0.47±0.09), (0.48±0.08)] and protein [(0.25±0.04), (0.26±0.05)] in H9c2 cardiomyocytes in H/R group and H/R+pCMV6 group decreased significantly, while the expressions of SERP1 mRNA (2.94±0.52) and protein (0.83±0.12) in H9c2 cardiomyocytesin H/R+pCMV6-SERP1 group increased significantly (P<0.05). Compared with H/R group and H/R+pCMV6 group, the levels ofSERP1 mRNA and protein in H9c2 myocardial cells in H/R+pCMV6-SERP1 group were significantly increased (P<0.05). Comparedwith NC group [(100.00±00.00)%, (4.45±0.62)%], H9c2 myocardial cell viability [(49.86±5.14)%, (48.75±5.23)%, (89.72±8.61)%] andB-cell lymphoma-2 (Bcl-2) protein levels were significantly decreased in H/R group, H/R+pCMV6 group and H/R+pCMV6-SERP1 group (P<0.05), while the apoptotic rate of H9c2 cardiomyocyte [(49.86±5.14)%, (48.75±5.23)%, (89.72±8.61)%] and the expressions of Bcl-2 Associated X Protein (Bax) and cysteinyl aspartate specific proteinase-3 (Caspase-3) proteins were significantly increased (P< 0.05). Compared with H/R group and H/R+pCMV6 group, the survival rate and Bcl-2 protein expression level of H9c2 cardiomyocytes in H/R+pCMV6-SERP1 group increased significantly, while the apoptotic rate, Bax and Caspase-3 protein expression levels decreased significantly (P<0.05).Conclusions Overexpression of SERP1 may protect H9c2 cardiomyocyte apoptosis induced by hypoxia/reoxygenation by up-regulating Bcl-2 protein and down-regulating Bax and Caspase-3 protein expressions.