摘要
目的研究动力相关蛋白1(Drp1)在心肌梗死后不良重塑中的变化及其作用。方法通过结扎小鼠冠状动脉左前降支成功制备MI动物模型后,使用小动物超声检测心脏功能,Masson染色检测心肌纤维化水平,qRT-PCR及Western Blot检测Drp1的表达情况;小鼠心肌细胞系(MCMs)经低氧(1%O2,5%CO2,94%N2 8 h)干预后,荧光染色观察Drp1的表达变化,DHE染色检测心肌细胞中活性氧簇(ROS)含量,化学发光法测定细胞中超氧化物含量,TUNEL染色及Caspase-3活性检测细胞凋亡水平。结果 MI明显增加Drp1 mRNA和蛋白表达水平(P<0.01),抑制Drp1(Mdivi-1,Drp1抑制剂)可改善MI后左室短轴缩短率(LVFS)(P<0.05)和左室射血分数(LVEF)(P<0.05),并减轻心肌纤维化水平(P<0.05);细胞低氧环境增加Drp1表达,然而抑制Drp1可减少低氧环境所导致的ROS及Caspase-3的生成(P<0.01),并最终降低心肌细胞凋亡水平(P<0.01)。结论抑制Drp1可减轻心肌细胞氧化应激反应、减少心肌细胞凋亡,从而改善心肌梗死后不良重塑。
Objective To investigate the alteration and the role of dynamin-related protein 1(Drp1) in cardiac remodeling after myocardial infarction(MI). Methods The mouse model of MI was successfully established by the ligation of the left main descending coronary artery. Ultrasound echocardiography was to evaluate cardiac function and then the hearts were removed and stained with Masson to measure the myocardial fibrosis area. qRT-PCR and western blotting were used to detect the mRNA and protein expression of Drp1, respectively. In vitro, mouse cardiac myocytes(MCMs) were incubated in hypoxic environment(1% O2, 5% CO2, 94% N2;8 h). The alterations of Drp1 were detected by fluorescent staining. The intracellular reactive oxygen species(ROS) level was tested by DHE staining and the contents of superoxide were measured by chemiluminescence. The apoptosis of cardiomyocytes were measured by Caspase-3 and TUNEL staining. Results MI obviously increased the expression of Drp1 in mRNA(P<0.01) and protein level(P<0.01). In contrast, the left ventricular fractional shortening(LVFS)(P<0.05), left ventricular ejection fraction(LVEF)(P<0.05) and the fibrosis area were preserved by the inhibition of Drp1(Mdivi-1, the inhibitor of Drp1)(P<0.05). The expression of Drp1 was significantly elevated in cells treated with hypoxic. The elevated generation of ROS(P<0.01), augmented production of Caspase-3(P<0.01) and increased apoptotic ratio of myocardial cells(P<0.01) were partly attenuated by the suppression of Drp1. Conclusion The inhibition of Drp1 protected against adverse remodeling after MI in mouse through inhibiting oxidative stress and cell apoptosis.
作者
王波
沈松林
李丹
WANG Bo;SHEN Songlin;LI Dan(The Third People Hospital of Mianyang ,Mianyang 621000,Sichuan,China;Mianyang Red Cross Center Blood Station, Mianyang 621000,Sichuan,China)
出处
《西部医学》
2019年第10期1517-1521,共5页
Medical Journal of West China
基金
四川省医学会科研项目(SHD14-14)
关键词
心肌梗死
心肌重塑
动力相关蛋白1
氧化应激
细胞凋亡
Myocardial infarction
Myocardial remodeling
Dynamin-related protein 1
Oxidative stress
Cell apoptosis
