抗菌肽PR-39减轻大鼠肾脏缺血再灌注损伤的研究

The study of protective role of PR-39 on renal ischemia-reperfusion injury in rats

目的 探讨抗菌肽PR-39对SD大鼠肾脏缺血再灌注损伤的作用及其机制.方法 选择60只雄性SD大鼠,随机数字表法分为试验KP组及阴性对照KE组,建立大鼠自体原位肾移植模型,KP组制备模型时经肾动脉注射含有肾组织特异性启动子KSP和目的基因PR-39的重组腺病毒,KE组注射仅含有KSP的空白病毒载体.对模型制备后2d的大鼠肾组织行HE、免疫组织化学及原位末端标记法（TUNEL）染色,对肾小管间质损伤进行评分,计算肾小管周微血管稀疏指数.监测造模前后大鼠的肾功能,比较KP及KE组间肾功能指标（血尿素氮、血肌酐）水平.结果 和假手术组比较,IRI组大鼠肾功能水平升高,肾组织可见部分肾小球及肾小管损伤,证明大鼠原位肾移植IRI模型制作成功;目的基因PR-39特异性表达于肾间质组织,而肾小球未见表达;表达PR-39的肾组织损伤程度较阴性对照组轻,肾小管凋亡细胞数及肾小管损伤评分明显小于阴性对照KE组,KP组肾小管周微血管缺失指数小于KE组.KP组大鼠血尿素氮及肌酐水平显著低于KE组,且肾功能恢复较快.结论 在肾间质及肾小管中特异性表达的PR-39,能通过抑制肾小管上皮细胞凋亡、促进管周微血管生成,从而发挥其对IRI肾组织的保护作用.

Objective To explore the protective role of PR-39 on the ischemia reperfusion injury renal tissue of rats.Methods 60 male SD rats were enrolled and randomly divided into experimental KP group and negative control KE group.The rats orthotopic renal transplantation model were established.The recombinant adenoviral vectors containing promoter KSP and PR-39 gene （KP） or none （KE） were injected via renal artery.HE staining,immunohistochemistry and TUNEL staining were performed on the rats＇ renal tissues at 2 days after IRI modeling,and the renal tubular interstitial injury score and peritublar capillary rarefaction was also evaluated.The renal function related factors of rats was monitored before and after IRI,and the blood urea nitrogen and creatinine level was also compared between KP and KE groups.Results Blood urea and creatinine concentration was increased,part of glomerular and tubular injury in renal tissue were also visible in rats underwent renal IRI,which proved the rat orthotopic renal transplantation model were successfully estabilshed.PR-39 gene specifically expressed in renal interstitial tissue,but not in glomerular.The degree of kidney tublar injury and the number of apoptotic cells were lower in KP groups by comparing with negative control KE groups.Renal tubular injury was significantly decreased in group KP than in group KE.Peritubular capillary rarefaction index is smaller in KP than in KE group.The blood urea nitrogen and creatinine level in KP group were significantly lower than those in KE group,and the renal function were also recovered more quickly.Conclusion The specific expressed PR-39 in renal interstitial and tubule,can inhibit the apoptosis of renal tubular epithelial cells and promote the angiogenesis of peritubular capillary,so as to exert its protective role on IRI renal tissue.