摘要
目的:观察雌激素膜受体GPER1对心肌细胞氧化损伤的保护作用,并探讨其通过PI3K/Akt信号通路上调Nrf2,减轻心肌氧化损伤的机制。方法:H_2O_2处理原代培养的新生大鼠心肌细胞建立氧化损伤模型,分为对照组、H_2O_2处理组,GPER1受体激动剂G1预处理+H_2O_2处理组和GPER1拮抗剂G15+G1预处理+H_2O_2处理组,MTT检测细胞活性,Hoechst33342染色和cleaved caspase-3免疫荧光染色观察细胞凋亡,并检测细胞内氧自由基,总抗氧化能力,超氧化物歧化酶(SOD)和丙二醛(MDA)的水平。Western blot测定细胞中p-Akt和细胞核内Nrf2的水平。结果:G1显著抑制H_2O_2导致细胞活性下降和细胞凋亡,并降低细胞内氧自由基水平,提高总抗氧化能力,增加SOD活性,减少MDA含量,但G15能拮抗G1的上述效应。同时G1能增加细胞内Akt磷酸化水平和细胞核内Nrf2的表达,这些效应可被G15和LY-294002阻断。结论:GPER1通过PI3K/Akt信号通路,调节Nrf2的表达,抑制氧化应激导致的心肌细胞损伤。GPER1可以作为开发心肌缺血损伤保护剂的一个潜在靶点。
Objective： To investigate the cardioprotection effects mediated by G Protein-Coupled Estrogen Receptor 1（GPER1）and the mechanism of inhibition of oxidative damage by upregulating Nrf2 expression via PI3K/Akt signaling pathway. Methods：H_2O_2-induced injury in neonatal rat cardiomyocytes in vitro to simulate the oxidative damage following myocardial ischemia/reperfusion.The neonatal rat cardiomyocytes were divided into control group, H_2O_2 treation group, G1-pretreation before H_2O_2 exposure group and G15 treated and then G1-pretreation before H_2O_2 exposure group. Cell viability was assessed by MTT assay and cell apoptosis was assessed by Hoechst33342 staining and immunofluorescence staining for cleaved caspase-3. In addition, intracellular oxygen free radicals, total antioxidant capacity, superoxide dismutase（SOD） and malondialdehyde（MDA） levels were detected. Further, the phosphorylation of Akt and Nrf2 level in rat cardiomyocytes were determined by Western blot analyses. Results： G1 significantly inhibited the decrease in cell activity and cell apoptosis, reduced the level of oxygen free radicals and MDA, improved the total antioxidant capacity, and increased SOD activity in H_2O_2-treated neonatal rat cardiomyocytes, all of which were markedly attenuated by G15. Further, activation of GPER1 increases the phosphorylation of Akt and Nrf2 level in neonatal rat cardiomyocytes after H_2O_2 exposure,which were abolished by G15 and LY-294002. Conclusion： Activation of GPER1 protects neonatal rat cardiomyocytes against H_2O_2-induced cell injury by upregulating Nrf2 expression via PI3K/Akt signaling pathway. GPER1 may be a potential target to prevent myocardial ischemia injury.
出处
《现代生物医学进展》
CAS
2016年第10期1807-1811,1828,共6页
Progress in Modern Biomedicine
基金
国家自然科学基金项目(81200902)
中国博士后科学基金项目(2014T70986)
陕西省自然科学基金项目(S2015YFJQ1250)
