基于脓毒症致肌萎缩大鼠模型探讨SIRT肌损伤保护作用及其对细胞线粒体自噬的影响

The protective effect of SIRT muscle injury and mitochondrial autophagy based on a rat model ofmuscular atrophy induced by sepsis

目的通过建立脓毒症致肌萎缩大鼠模型,探讨SIRT肌损伤保护作用及心肌细胞线粒体自噬的影响。方法选择65只体重在200 g-300 g的SD雄性大鼠,按照随机原则分为A、B大组,建立脓毒症致肌萎缩大鼠模型,采用ELISA法检测TNF-α、IL-6水平检测建模是否成功。通过检测线粒体膜电位、ATP和活性氧来评价其功能;采用Western Blot对SIRT、PINK1、FOXO3a、Parkin、LC3-Ⅱ/Ⅰ蛋白的变化。结果LPS组、模型组、LPS+制动+SIRT组大鼠的TNF-α、IL-6水平高于正常组和单纯制动组(P<0.01);与模型组相比,LPS+制动+SIRT组TNF-α、IL-6水平有所降低(P<0.01);模型组MMP、ATP水平比正常组、LPS组、单纯制动组较低,ROS水平有所升高(P<0.01);模型组的蛋白SIRT、FOXO3a、PINK1、Parkin、LC3-Ⅱ/Ⅰ水平比正常组、LPS组、单纯制动组低(P<0.01);LPS+制动+线粒体自噬激动剂小檗碱组线粒体蛋白水平高于LPS+制动+SIRT组(P<0.01)。结论脓毒症致肌萎缩过程中,会降低SIRT和线粒体自噬水平,损伤线粒体功能,干预SIRT能改善脓毒症致肌萎缩的进展。

Objective To investigate the protective effect of SIRT on myocardial injury and the effect of mitochondrial autophagy on myocardial cells by establishing a rat model of muscular atrophy induced by sepsis.Methods Sixty-five male SD rats with a weight of 200g and 300g were randomly divided into group A and group B,and then a rat model of muscular atrophy induced sepsis was established.The modeling of TNF-αand IL-6 levels was successfully detected by ELISA method.Mitochondrial membrane potential,ATP and reactive oxygen species were detected to evaluate their functions.Western blot was used to detect the changes of SIRT,PINK1,FOXO3a,Parkin,and LC3-Ⅱ/Ⅰ proteins.Results The levels of TNF-α and IL-6 in LPS group,model group,LPS+brake+SIRT group were higher than those in normal group and simple brake group(P<0.01).Compared with the model group,the levels of TNF-αand IL-6 in LPS+brake+SIRT group were decreased(P<0.01).The levels of MMP and ATP in the model group were lower than those in the normal group,LPS group,and simple brake group,while ROS levels were increased(P<0.01).The protein levels of SIRT,FOXO3a,PINK1,Parkin,and LC3-Ⅱ/Ⅰ in the model group were lower than those in normal group,LPS group and simple brake group(P<0.01).The level of mitochondrial protein in group with LPS combined with immobilization and mitochondrial autophagy agonist berberine was higher than that in LPS+immobilization+SIRT group(P<0.01).Conclusion During the process of sepsis induced muscular atrophy,the levels of SIRT and mitochondrial autophagy are reduced,and mitochondrial function is damaged.Intervention with SIRT can improve the progress of muscle atrophy caused by sepsis.