抑制Rictor对脓毒症小鼠心肌自噬水平的影响

Effect of inhibition of Rictor on myocardial autophagy in sepsis mice

目的研究抑制Rictor对脓毒症小鼠心肌自噬水平的影响。方法健康雄性SPF级昆明种小鼠36只采用随机数字表法为假手术组、模型组、实验组,每组12只。利用盲肠结扎穿孔术建立脓毒症动物模型,实验组给予Rictor特异性抑制剂JR-AB2-01110 mg/kg腹腔注射,假手术组及模型组给予等量生理盐水。术后12 h及24 h分别取各组6只小鼠采集腹主动脉血,检测血清心肌肌钙蛋白I(cTnI)及肌酸激酶同工酶(CK-MB)水平;检测小鼠心尖组织中Rictor、Akt、Raptor、LC3B表达变化;透射电镜及HE染色下观察心肌组织病理结构变化。结果模型组各时间点cTnI、CK-MB、Rictor、Phospho-Aktser473、Raptor高于假手术组(P<0.05)。实验组各时间点cTnI、CK-MB、Rictor、Phospho-Aktser473、Raptor低于模型组,LC3B高于模型组(P<0.05)。假手术组心肌组织排列正常;模型组可见心肌纤维中度水样变性;实验组可见少量心肌纤维水样变性,细胞肿胀。透射电镜下,模型组及实验组均可观察到自噬体及自噬溶酶。结论抑制Rictor可增强脓毒症小鼠心肌细胞自噬,减轻细胞损伤。

Objective To study the effect of inhibition Rictor on myocardial autophagy in sepsis mice.Methods A total of 36 healthy male SPF Kunming mice were divided into sham operation group,model group,and experimental group according to the random number table method,with 12 mice in each group.The animal model of sepsis was established by cecal ligation and puncture.The experimental group was given 10 mg/kg intraperitoneal injection of Rictor-specific inhibitor JR-AB2-011,the sham operation group and model group were given the same amount of normal saline.Abdominal aortic blood was collected from six mice in each group at 12 and 24 h postoperatively,and the levels of serum cardiac troponin I(cTnI)and creatine kinase MB(CK-MB)were detected.The expression changes of Rictor,Akt,Raptor,and LC3B in mouse myocardial tissue were detected;the pathological changes of myocardial tissue were observed by transmission electron microscope and HE staining.Results In model group,cTnI,CK-MB,Rictor,Phospho-Aktser473,and Raptor at each time point were higher than those in sham operation group(P<0.05).In the experimental group,cTnI,CK-MB,Rictor,Phospho-Aktser473,and Raptor at each time point were lower than those in model group,and LC3B were higher than that in model group(P<0.05).The myocardial fibers of the sham operation group was normal;moderate watery degeneration of myocardial fibers can be seen in model group;a small amount of myocardial fibers showed watery degeneration and cell swelling in experimental group.Autophagosomes and autophagy lysozyme could be observed in model group and experimental group.Conclusion Inhibition Rictor can enhance autophagy of myocardial cells in sepsis mice and reduce cell damage.