辛伐他汀对大鼠肾缺血再灌注损伤中Wnt/JNK影响的研究

目的:探讨辛伐他汀(simvastatin SIM)对大鼠肾缺血再灌注损伤中Wnt/JNK的影响。方法:雄性wistar大鼠36只随机分为:假手术组、手术组、SIM干预组,每组12只,再将每组按取材时间不同分为6 h、48 h两个时相组。手术方法:假手术组开腹分离双侧肾动脉,但不夹闭,后关闭腹腔;手术组游离双侧肾动脉,动脉夹夹闭45 min后恢复灌注建立肾IRI模型;SIM干预组术前1周给大鼠灌胃SIM 20 mg.kg-1.d-1,其余处理同手术组。肾IRI后6 h、48 h,检测血清Scr值,肾组织行病理学观察及免疫组织化学法测定Wnt4、JNK1及其信号通路下游炎症因子TNFα的表达,并采用real time PCR法测定肾组织Wnt4 mRNA、JNK1 mRNA的表达。结果:肾组织病理学观察:假手术组肾组织形态结构基本正常;手术组肾小管上皮细胞有不同程度的肿胀、坏死和脱落、排列紊乱,管腔扩张,肾间质水肿、炎细胞浸润明显,以IRI后6 h为著;SIM干预组肾组织损伤程度较手术组明显减轻。Scr值测定:手术组Scr值较假手术组明显升高(P<0.01);SIM干预组Scr值较手术组有所下降(P<0.01);以IRI后6 h,Scr值较高(P<0.01)。免疫组化检测:假手术组肾小管上皮细胞Wnt4、JNK1、TNFα表达较弱;手术组IRI后肾小管上皮细胞胞浆内Wnt4、JNK1、TNFα表达均比假手术组增强(P<0.01),以6 h时为著(P<0.01)。SIM干预组Wnt4、JNK1、TNFα表达水平较手术组减弱(P<0.05)。real time PCR检测:假手术组肾小管上皮细胞Wnt4 mRNA、JNK1 mRNA表达较弱;手术组肾小管上皮细胞Wnt4 mRNA、JNK1 mRNA表达均较假手术组增强(P<0.01),以6 h为著(P<0.01);SIM干预组Wnt4 mRNA、JNK1 mRNA表达比手术组均有所下降(P<0.01)。相关性分析:JNK1与Wnt4、TNFα均成正相关(rs=0.94,rs=0.95);Wnt4 mRNA、JNK1 mRNA成正相关(rs=0.75);且均与Scr成正相关(rs分别为rs=0.93,rs=0.96,rs=0.94,rs=0.70,rs=0.35)。结论:辛伐他汀预处理可能通过抑制Wnt/JNK信号通路的表达,从而减轻肾IRI程度。

Effect of Simvastatin on the Expression of Wnt/JNK in Rats with Renal Ischemia-reperfusion Injury

Objective:Effect of simvastatin on the expression of Wnt/JNK in rats with renal ischemia-reperfusion injury.Methods: 36 male Wistar rats were divided randomly into sham-operation group,ischemia-reperfusion group and simvastatin-treated group,for each including two phases at 6 h and 48 h.Rats in sham-operation group had renal arteries separated without clipping;IRI model was established by bilateral clipping of renal arteries for 45 minute.Rats in simvastatin-treated group had administered simvastatin 20 mg·kg-1·d-1 for seven days before operation.The levels of serum creatinine(Scr) were detected at 6 h and 48 h time points.The renal pathological changes were detected under light microscope.Immunohistochemistry were used to detect expression levels of Wnt4,JNK1 and TNFα which was the inflammatory factor of its signal path.The expression of Wnt4 mRNA and JNK1 mRNA were detected by real time PCR.Results:Renal pathological change: The pathomorphological changes of renal tissues in sham-operation group observed by light microscopes were normal.Histopathlogical changes of renal tubular epithelial cells were swelling,desquamative or flattened epithelia,necrotic debris,edema in the interstitium and inflammatory cell infiltration in ischemia-reperfusion group.It is obvious at 6 h.Pathological changes in kidney were milder in simvastatin-treated group.Scr detect: As compared with the sham operation group,the levels of Scr was increased significantly in ischemia-reperfusion group;and the levels of Scr was decreased in simvastatin-treated group(P<0.01).It is obvious at 6 h(P<0.01).Immunohistochemistry display: The expression of Wnt4,JNK1 and TNFα in renal tubular epithelial cells were increased significantly in the ischemia-reperfusion group than its in the sham-operation group(P<0.01).It is obvious at 6(P<0.01).The expression were relieved in simvastatin-treated group(P<0.05).real time PCR: As compared with the Sham operation group,the conten of wnt4 mRNA and JNK1 mRNA were increased by real time PCR(P<0.01).It is obvious at 6 h and relieved in simvastatin-treated group(P<0.01).Correlation analysis: The expression of JNK1 was positive correlation with the expression of Wnt4 and TNFα(rs=0.94,rs=0.95).The conten of wnt4 mRNA was positive correlation with the JNK1 mRNA(rs=0.75).And those were positive correlation with the levels of Scr(rs=0.93,rs=0.96,rs=0.94,rs=0.70,rs=0.35).Conclusion:Pretreatment with simvastatin relieved the renal injury of IRI,which mechanism may be involved in the inhibition of the Wnt/JNK signal path.