雷帕霉素对大鼠肾缺血再灌注后心肌损伤的作用及机制研究

Effects and mechanism of rapamycin on cardiac injury after renal ischemia reperfusion in rats

目的探究雷帕霉素(rapaycin,RAPA)对大鼠肾缺血再灌注(renal ischemia reperfusion,RIR)后远隔器官心脏损伤的影响。方法40只大鼠随机平均分为四组:空白组、假手术组、RIR组和雷帕霉素处理组,每组10只。雷帕霉素处理组的大鼠接受雷帕霉素灌胃给药。术后24 h处死每组大鼠,收集血液,脾和心脏。测定血浆中肌酸激酶(CK)、肌酸激酶同工酶(CK-MB)、血清肌酐(SCr)和尿素氮(BUN)的水平。用PAS染色半定量分析表示心脏病理损伤程度。TUNEL试剂盒检测细胞凋亡情况。流式细胞仪检测NKT细胞数量的百分比。RT-qPCR方法检测CXC趋化因子配体10(CXCL10)、缺氧诱导因子-1α(hypoxia-inducible factoR-1α,HIF-1α)mRNA和血管内皮生长因子(VEGF)mRNA表达。结果RIR组血清BUN值和SCr值高于假手术组。雷帕霉素处理组血清CK值和CK-MB值水平低于模型组。心脏病理损伤的半定量评分表明,雷帕霉素处理组的病理损伤评分明显低于RIR组。雷帕霉素处理组心脏和外周血NKT细胞百分比明显高于RIR组。雷帕霉素处理组脾NKT细胞百分比低于RIR组。雷帕霉素处理组HIF-1αmRNA和VEGF mRNA的表达程度低于RIR组。雷帕霉素处理组CXCL10 mRNA的表达水平高于RIR组。结论RAPA可以显著上调CXCL10的表达水平,促进NKT细胞从脾到外周血在心脏中的集聚。RAPA还可以抑制HIF-1α表达水平从而对RIR后心脏发挥保护作用。

Objective To investigate the effect of rapamycin on cardiac damage in remote organs after renal ischemia reperfusion(RIR)in rats.Methods A total of 40 rats were randomly divided into four groups:blank group,sham operation group,RIR group and rapamycin treatment group,with 10 rats in each group.Rats in the rapamycin treatment group received gastric administration of rapamycin.Each group of rats was sacrificed 24 hours after surgery,and blood,spleen tissue and heart tissue were collected.The creatine kinase(CK),creatine kinase isoenzyme(CK-MB),serum creatinine(SCr)and blood urea nitrogen(BUN)levels were measured.Semi-quantitative analysis with PAS staining indicated pathological damage to the heart.A TUNEL kit was used to detect apoptosis.The percentage of NKT cells was measured by flow cytometry.The expression levels of CXC chemokine ligand 10(CXCL10),hypoxia-inducible factoR-1α(HIF-1α)and vascular endothelial growth factor(VEGF)were detected by RT-qPCR.Results The BUN and SCr levels were higher in the RIR group than in the sham group.The serum CK and CK-MB levels were lower in the rapamycin treatment group than in the model group.Semi-quantitative scoring of cardiac pathological lesions showed that the pathological damage score of the rapamycin treatment group was significantly lower than that of the RIR group.The percentage of NKT cells in the heart and peripheral blood was significantly higher in the rapamycin treatment group than in the RIR group.The percentage of spleen NKT cells was lower in the rapamycin treatment group than in the RIR group.The expression of HIF-1αmRNA and VEGF mRNA was lower in the rapamycin treatment group than in the RIR group.The expression level of CXCL10 mRNA was higher in the rapamycin treatment group than in the RIR group.Conclusions Rapamycin can significantly up-regulate the expression level of CXCL10 and promote the migration of NKT cells from the spleen to peripheral blood and the heart.Rapamycin also inhibits HIF-1αexpression levels and protects the heart after RIR.