精胺通过抑制内质网应激减缓柯萨奇B3病毒诱导的心肌细胞损伤

Spermine Alleviates Coxsackie Virus B3-induced Cardiomyocytes Injury through Inhibiting Endoplasmic Reticulum Stress

目的:探讨外源精胺在柯萨奇B3病毒(Coxsackie virus B3,CVB3)诱导的乳鼠心肌细胞损伤中的保护作用及其调控机制。方法:CVB3感染原代培养的乳鼠心肌细胞,将细胞随机分为3组:对照(control)组;病毒感染(CVB3)组;精胺干预(CVB3+Sp)组。MTT试剂检测细胞增殖;流式细胞术检测细胞凋亡;Western blot检测Bcl-2、Bax、Caspase-3、Caspase-9、GRP78、CHOP、Caspase-12、p-PERK、PERK、p-eIF2α和e IF2α的蛋白表达。结果:与control组相比,CVB3组的细胞增殖率显著降低(P<0.05);凋亡率显著增加(P<0.05);Bcl-2的表达下调,Bax、Caspase-3、Caspase-9蛋白表达增加(P<0.05);GRP78、CHOP和Caspase-12的表达显著上调(P<0.05);p-PERK和p-eIF2α的表达显著上调(P<0.05)。与CVB3组相比,CVB3+Sp组的细胞增殖率显著上升(P<0.05);凋亡率显著下降(P<0.05);Bcl-2的表达上调,Bax、Caspase-3、Caspase-9蛋白表达下调(P<0.05);GRP78、CHOP和Caspase-12的表达显著下调(P<0.05);p-PERK和p-eIF2α的表达显著下调(P<0.05)。结论:外源精胺可以缓解CVB3诱导的乳鼠心肌细胞增殖降低和细胞凋亡增多等损伤,这可能与精胺抑制PERK-eIF2α信号通路介导的内质网应激有关。

Objective： To investigate the protective effect of exogenous spermine on Coxsackie virus B3 （CVB3）-induced neonatal rat cardiomyocytes injury and its regulatory mechanism. Methods： The primary neonatal rat cardiomyocytes were infected with CVB3, and the cells were randomly divided into 3 groups, control group, CVB3 group, CVB3 ＋ Sp group. The cell proliferation was measured by MTT assay. The cell apoptosis was detected by flow cytometry. The protein expression levels of Bcl-2, Bax, Caspase-3, Caspase-9, GRP78, CHOP, Caspase-12, p-PERK, PERK, p-elF2a and elF2a were detected by western blot assay. Results： Compared with the con- trol group, the cell proliferation rate was significantly reduced （P〈0.05）; the apoptosis rate was increased （P〈0.05）; the protein expres- sion level of Bcl-2 was down-regulated, the expression levels of Bax, Caspase-3, Caspase-9 were increased （P〈0.05）; the expression lev- els of GRP78, CHOP and Caspase-12 were significantly up-regulated （P 〈0.05）; the protein expression levels of p-PERK and p-elF2a were dramatically up-regulated （P〈0.05） in the CVB3 group. Compared with the CVB3 group, the cell proliferation rate was significantly increased （P〈0.05）; the apoptosis rate was decreased significantly （P〈0.05）; the protein expression of Bcl-2 was up-regulated, the expres- sion levels of Bax, Caspase-3, Caspase-9 were down-regulated （P〈0.05）; the expression levels of GRP78, CHOP and Caspase-12 expres- sion were significantly lower （P〈0.05）; the protein expression of p-PERK and p-elF2a expression were significantly lower （P〈0.05） in the CVB3 ＋ Sp group. Conclusions： Exogenous spermine may alleviate CVB3-induced proliferation reduction and apoptosis in neonatal rat cardiomyocytes, which may be related with the inhibition of PERK-elF2a signaling pathway-mediated endoplasmic reticulum stress.