格列美脲对细颗粒物PM2.5诱导的心肌样细胞损伤的保护作用及机制研究

Protective Effect and Mechanism of Glimepiride on Myocardial-like Cell Injury Induced by PM2.5

目的:探讨格列美脲对细颗粒物空气动力学直径<2.5μm(PM 2.5)诱导的心肌样细胞损伤的保护作用及机制研究。方法:采用噻唑蓝(MTT)确定PM2.5的干预浓度;将大鼠心肌样细胞H9c2分为对照组(含血清1640培养基)、PM2.5组(800mg·L^-1)、格列美脲低、中、高剂量组(10,20,40μmol·L^-1的格列美脲+800 mg·L^-1的PM 2.5)。培养24 h后检测H9c2细胞中肿瘤坏死因子-α(TNF-α)和白细胞介素^-1β(IL^-1β)含量,同时检测细胞中活性氧(ROS)和细胞凋亡率,检测B淋巴细胞瘤-2(Bcl-2)、Bcl-2-Associated X的蛋白质(Bax)和半胱氨酸天冬氨酸特异性蛋白酶-3(caspase-3)mRNA表达水平。结果:随着PM 2.5浓度的增加,H9c2细胞增值率降低,在800 mg·L^-1时H9c2细胞增值率降到46.28%,故选800 mg·L^-1作为PM 2.5的干预浓度;与PM 2.5组比较,格列美脲各剂量组细胞中TNF-α、IL^-1β含量、ROS荧光强度、细胞凋亡率、Bax和caspase-3 mRNA的相对表达量显著降低(P<0.05),Bcl-2 mRNA的相对表达量显著升高(P<0.05),且呈剂量相关性(P<0.05)。结论:格列美脲对细颗粒物PM2.5诱导的心肌样细胞损伤具有保护作用,其机制可能与格列美脲减轻炎症反应和氧化应激、抑制心肌细胞凋亡有关。

Objective:To investigate the protective effect and underlying mechanism of glimepiride on myocardial-like cell injury induced by PM2.5.Methods:The intervention concentration of PM2.5 was determined by MTT.Rat’s cardiomyocyte-like cells H9c2 were divided into the control group(containing serum 1640 medium),PM2.5 group(800 mg·L^-1),glimepiride low,medium and high dose groups(10,20 and 40μmol·L^-1 glimepiride+800 mg·L^-1 PM2.5).After 24 hours,the contents of TNF-αand IL^-1βin H9c2 cells were detected.The level of ROS and the apoptotic rate were detected.The mRNA expressions of Bcl-2,Bax and caspase-3 were detected as well.Results:With the increase of PM2.5 concentration,the proliferation rate of H9c2 cells decreased.At 800 mg·L^-1,the proliferation rate of H9c2 cells decreased by 46.28%.Therefore,800 mg·L^-1 was chosen as the intervention concentration of PM2.5.Compared with those in PM2.5 group,the levels of TNF-αand IL^-1β,ROS fluorescence intensity,apoptotic rate,mRNA expressions of Bax and caspase-3 in glimepiride low,medium and high dose groups decreased significantly(P<0.05),while the mRNA expression of Bcl-2 increased significantly(P<0.05),and showed a dose-dependent manner(P<0.05).Conclusion:Glimepiride has protective effect on PM2.5-induced cardiomyocyte injury.The protective effect of glimepiride on PM2.5-induced cardiomyocyte injury may be related to the alleviation of inflammatory response and oxidative stress and the inhibition of cardiomyocyte apoptosis of glimepiride.