高浓度氢气对脓毒症小鼠心肌损伤及Mst1表达的影响

Effect of high concentration hydrogen on myocardial injury and expression of Mst1 in septic mice

目的评价高浓度氢气对脓毒症小鼠心肌损伤及哺乳动物不育系20-样激酶1(Mst1)表达的影响。方法清洁级健康雄性C57BL/6J小鼠105只,6~8周龄,体质量20~25 g,采用随机数字表法分为3组(n=35):假手术组(Sham组)、脓毒症组(SEP组)和脓毒症+高浓度氢气组(SEP+HCH组)。采用盲肠结扎穿孔法制备脓毒症小鼠心肌损伤模型。SEP+HCH组术后1和6 h时分别吸入高浓度(66.7%)氢气1 h。每组随机取20只小鼠,观察术后7 d生存情况。于术后24 h时深麻醉后取内眦血样,采用ELISA法测定TNF-α和IL-6浓度,随后处死取心脏组织,光镜下观察病理学结果,TUNEL法观察心肌细胞凋亡情况,Western blot法检测Mst1、动力相关蛋白1(Drp1)和线粒体融合蛋白2(Mfn2)的表达。结果与Sham组比较,SEP组术后7 d生存率降低,心肌病理学损伤评分、心肌细胞凋亡指数、TNF-α和IL-6浓度升高,Mst1和Drp1表达上调,Mfn2表达下调(P<0.05);与SEP组比较,SEP+HCH组术后7 d生存率升高,心肌病理学损伤评分、心肌细胞凋亡指数、TNF-α和IL-6浓度降低,Mst1和Drp1表达下调,Mfn2表达上调(P<0.05)。结论吸入高浓度氢气可减轻脓毒症小鼠心肌损伤,其机制可能与下调Mst1表达,改善线粒体动力学,抑制心肌细胞凋亡有关。

Objective To evaluate the effect of high concentration hydrogen on myocardial injury and expression of mammalian STE20-like protein kinases 1(Mst1)in septic mice.Methods One hundred and five clean-grade healthy male C57BL/6J mice,aged 6-8 weeks,weighing 20-25 g,were divided into 3 groups(n=35 each)using a random number table method:sham operation group(group Sham),sepsis group(group SEP),and sepsis+high concentration hydrogen group(group SEP+HCH).The model of sepsis-induced myocardial injury was developed by cecal ligation and perforation in anesthetized mice.In SEP+HCH group,high concentration hydrogen(66.7%)was inhaled for 1 h starting from 1 and 6 h after the successful preparation of the model.Twenty mice were taken from each group to observe the survival rate at day 7 after operation.Blood samples from the medial canthus were collected after deep anesthesia at 24 h after surgery for determination of tumor necrosis factor-α(TNF-α)and interleukin-6(IL-6)concentrations(by enzyme-linked immunosorbent assay).Then the animals were sacrificed,and the heart tissues were taken for examination of the pathological results(with a light microscope)which were scored and for determination of apoptosis in myocardial cells(by TUNEL)and expression of Mst1,dynamic-related protein 1(Drp1)and mitofusin 2(Mfn2)in myocardium(by Western blot).Results Compared with group Sham,the survival rate at 7 days after operation,pathological score,apoptosis index and concentrations of TNF-αand IL-6 were significantly increased,Mst1 and Drp1 expression was up-regulated,and Mfn2 expression was down-regulated in group SEP(P<0.05).Compared with group SEP,the survival rate at 7 days after operation,pathological score,apoptosis index and concentrations of TNF-αand IL-6 were significantly decreased,Mst1 and Drp1 expression was down-regulated,and Mfn2 expression was up-regulated in group SEP+HCH(P<0.05).Conclusions Inhalation of high-concentration hydrogen can attenuate the myocardial injury in septic mice,and the mechanism may be related to down-regulation of Mst1 expression,improvement in mitochondrial dynamics,and inhibition of apoptosis in myocardial cells.