输尿管结扎预适应通过上调热休克蛋白27的表达减轻肾脏缺血再灌注损伤

目的探讨热休克蛋白27（HSP27）在通过输尿管结扎（UO）预适应减轻小鼠肾脏缺血再灌注（IR）损伤中的作用及其机制。方法实验动物为雄性C57BL/6小鼠,①将小鼠随机分为3组,每组30只,对照组为正常C57BL/6小鼠,UO＋IR组小鼠经左侧输尿管结扎24 h后再通,再通48 h后行IR处理,non-UO＋IR组除不结扎左输尿管其余操作同UO＋IR组。比较3组小鼠再灌注后血清肌酐（Cr）水平,肾组织内肿瘤坏死因子-α（TNF-α）和白细胞介素-6（IL-6）mRNA表达情况。②取C57BL/6小鼠随机分为UO组与non-UO组,每组20只,UO组予以左侧UO处理24 h,再通48 h后检测左肾组织HSP27蛋白表达,并与non-UO小鼠对比。③取C57BL/6小鼠随机分为两组,每组50只,一组予以小鼠左肾注射包装有干扰HSP27表达的短发夹RNA的重组腺病毒100μL靶向抑制HSP27的表达,将该组设为HSP27干扰组,另一组小鼠予以注射空病毒100μL作为对照组,每组取10只小鼠验证HSP27干扰成功后,每组再随机分为UO＋IR及non-UO＋IR两个亚组（每个亚组20只小鼠）,观察HSP27对IR损伤和UO效应的影响,比较各组Cr水平,检测肾组织内TNF-α和IL-6 mRNA,以及凋亡效应蛋白胱天蛋白酶-3的表达水平。结果①UO＋IR组Cr水平较non-UO＋IR组显著降低（P〈0.05）,TNF-α及IL-6mRNA的表达明显低于non-UO＋IR组（P〈0.05）。②较non-UO组,UO组肾组织HSP27表达明显上调（P〈0.05）。③相对于non-UO＋IR处理,UO＋IR不能降低HSP27干扰组小鼠Cr水平（P〉0.05）、TNF-α和IL-6 mRNA的表达（P〉0.05）及胱天蛋白酶-3的表达（P〉0.05）,却可显著降低空病毒对照组小鼠以上各指标表达;且相对于空病毒对照组中UO＋IR亚组,HSP27干扰组中UO＋IR亚组以上各指标仍高表达（P〈0.05）。结论 UO通过上调HSP27表达减轻小鼠肾脏IR损伤,其机制可能与HSP27抑制炎性反应、减少细胞凋亡的作用有关。

Transient ureteral obstruction prevents against renal ischemia reperfusion injury via up-regulation of heat shock proteins 27

Objective To explore the role of heat shock proteins 27（HSP27） in the renal protective effects of ureteral ob struction（UO） preconditioning against subsequent renal ischemia/reperfusion（IR） injury.Methods ①Male C57BL/6 mice were randomly divided into 3 groups and 30 mice in each group： control group（sham operation）,UO＋IR group（left ureter was transiently ligated and recanalized after 24 h,and 48 h later unilateral renal IR was performed） and non-UO＋ IR group（only renal IR without UO）.Serum Cr levels and mRNA expression of pro-inflammatory mediators（TNF-α and IL-6） were measured among these 3 groups.②Male C57BL/6 mice were randomly divided into 2 groups： UO group and non-UO group（20 mice in each group）.The mice in UO group were suffered 24 h UO,then the renal samples were ob tain 48 h later to detect the expression of HSP27,compared with those in non-UO group.③Male C57BL/6 mice were randomly divided into 2 groups and 50 mice in each group.Mice that injected with short hairpin RNA recombinant ade novirus to silence murine HSP27 were defined as HSP27 RNA interfering（RNAi） group,and mice injected with un-re combinant adenovirus were defined as control group.Mice were subjected to IR with or without UO after interfering suc ceeded,then serum Cr levels,mRNA expression of pro-inflammatory mediators（TNF-α and IL-6） and caspase-3 were measured.Results ①Cr level and the mRNA expression of TNF-α and IL-6 in UO＋IR group,were significant lower than those in non-UO＋IR group（P 0.05）.②After UO the expression of HSP27 was higher than that in mice without UO（P 0.05）.③Silencing renal HSP27 removed the UO-induced renal protection,indicated by higher Cr level and more expression of pro-inflammatory mediators（TNF-α and IL-6） and caspase-3 than control group（P 0.05）.Conclusion UO can improve subsequent renal IR injury via up-regulation of HSP27,which is related to HSP27-mediated anti-inflammation and reduction of apoptosis.