SLN基因下调对心肌细胞氧化应激损伤保护作用的机制研究

Mechanism of protective effect of SLN gene down-regulation on oxidative stress injury in cardiomyocytes

目的探讨肌脂蛋白(SLN)基因下调对心肌细胞氧化应激损伤的保护作及作用机制。方法培养心肌细胞AC16,分为对照组、过氧化氢(H2O2)组、H2O2+si-SLN组和H2O2+si-SLN+LY294002(磷脂酰肌醇-3-激酶/蛋白激酶B信号通路抑制剂)组,MTT检测细胞活性,酶联免疫吸附法检测细胞培养上清液中磷酸肌酸激酶(CK)、丙二醛(MDA)和超氧化物歧化酶(SOD)水平,Western blot检测AC16细胞SLN、磷脂酰肌醇3-激酶p85α亚单位(P13K p85α)和磷酸化蛋白激酶B(p-Akt)蛋白表达水平。结果与对照组比较,H2O2组AC16细胞活性明显降低,CK和MDA水平明显升高,SOD水平明显降低,SLN蛋白表达水平明显升高,P13K p85α和p-Akt蛋白表达明显降低,差异均有统计学意义(P<0.05);与H2O2组比较,H2O2+si-SLN组AC16细胞活性明显升高,CK和MDA水平明显降低,SOD水平明显升高,P13K p85α和p-Akt蛋白表达明显升高,差异均有统计学意义(P<0.05);与H2O2+si-SLN组比较,H2O2+si-SLN+LY294002组AC16细胞活性明显降低,CK和MDA水平明显升高,SOD水平明显降低,差异均有统计学意义(P<0.05)。结论SLN基因下调可能通过P13K/Akt信号通路保护H2O2诱导的心肌细胞氧化应激损伤。

Objective To investigate the protective effect and mechanism of sarcolipin(SLN)gene down-regulation on oxidative stress injury in cardiomyocytes.Methods AC16 cardiomyocytes were cultured and divided into control group,H2O2 group,H2O2+si-SLN group and H2O2+si-SLN+LY294002(PI3K/AKT signaling pathway inhibitor)group.MTT was used to detect cell viability,enzyme-linked immunosorbent assay was used to measure the levels of creatine kinase(CK),malondialdehyde(MDA)and superoxide dismutase(SOD)in the cell culture supernatant,and Western blot was used to detect the expression levels of SLN,P13K p85αsubunit and phosphorylated protein kinase B(p-Akt1)in AC16 cells.Results Compared with the control group,the activity of AC16 cells in H2O2 group was significantly decreased,the levels of CK and MDA were significantly increased,the SOD level was significantly decreased,the SLN protein expression level was significantly increased,and the expression levels of P13K p85αand p-Akt protein were significantly decreased,all with statistically significant differences(P<0.05).Compared with the H2O2 group,the activity of AC16 cells in H2O2+si-SLN group was significantly increased,the levels of CK and MDA were significantly decreased,and the SOD level and the expression levels of P13K p85αand p-Akt protein were significantly increased,all with statistically significant differences(P<0.05).Compared with the H2O2+si-SLN group,the activity of AC16 cells in H2O2+si-SLN+LY294002 group was significantly decreased,the levels of CK,MDA were significantly increased,and the SOD lever was significantly decreased,all with statistically significant differences(P<0.05).Conclusion Down-regulation of SLN gene may protect H2O2-induced cardiomyocyte oxidative stress injury by P13K/Akt signaling pathway.