Trps1在大鼠肾脏缺血再灌注损伤修复过程中的表达及意义

目的观察大鼠缺血再灌注损伤肾组织Trps1的表达变化及其与肾组织病变的关系,探讨Trps1在肾脏修复再生中的作用。方法 42只雄性SD大鼠分为假手术组、缺血再灌注组。经腹正中切口分离大鼠双侧肾蒂,用无损动脉夹夹闭60 min后恢复灌注,假手术组仅暴露肾蒂不夹闭。于再灌注后1、3、7、14、21 d取大鼠动脉血及肾组织标本,采用自动生化分析仪检测大鼠血肌酐、尿素氮水平,PAS染色检测肾组织损伤情况,免疫组化和Western blot检测肾组织Tprs1表达变化。结果假手术组大鼠血肌酐和尿素氮分别为(30.12±2.95)μmol/L、(5.89±0.67)mmol/L。与假手术组相比,大鼠肾脏缺血再灌注后1、3、7 d血肌酐[(319.25±25.49)、(338.20±22.70)、(216.07±18.54)μmol/L]及尿素氮[(33.53±8.06)、(78.05±7.13)、(42.61±11.87)mmol/L]显著升高(P<0.05),14、21 d血肌酐[(33.33±6.46)、(32.06±8.74)μmol/L]及尿素氮[(6.02±1.27)、(6.93±3.28)mmol/L]与假手术组相比无显著差异(P>0.05)。PAS染色显示肾组织在再灌注1 d时即出现损伤,3 d时损伤最重,7 d时损伤开始修复,至第21天修复完全。免疫组化及Western blot显示,假手术组Trps1主要在皮质肾小管上皮细胞表达,缺血再灌注后1 d肾组织Trps1表达显著下降(P<0.05),3 d仅见微弱表达(P<0.05),7、14 d表达开始上升,但仍有显著差异(P<0.05),21 d与假手术组水平无显著差异(P>0.05)。相关性分析显示Trps1表达变化与肾小管急性损伤评分呈负相关(r=-0.81,P<0.05)。结论 Trps1在AKI肾脏损伤修复期表达上调,与肾组织损伤指标呈负相关,提示其可能具有促进肾脏修复再生的作用。

Expression and significance of Trps1 in rat kidney repair after ischemia/reperfusion injury

Objective To study Trps1 expression changes in rat kidney after ischemia/reperfusion(I/R) injury and its relationship with renal pathological changes so as to explore the role of Trps1 in renal repair and regeneration.Methods Forty-two male SD rats were divided to a sham operation group and an I/R group.Kidney I/R rat model was established by clipping bilateral renal pedicles by artery clamps for 60 min after isolating them from surrounding tissues.On days 1,3,7,14 and 21 after kidney I/R,SCr and BUN were detected.Renal injury was observed under a light microscope with PAS staining,and Trps1 was tested by immunohistochemistry and Western blotting.Results The SCr and BUN levels in the sham operation group were(30.12±2.95) μmol/L and(5.89±0.67) mmol/L.The levels of SCr [(319.25±25.49),(338.20±22.70),and(216.07±18.54) μmol/L] and BUN [(33.53±8.06),(78.05±7.13),and(42.61±11.87) mmol/L] on days 1,3,and 7 were significantly higher in the I/R group than in the sham operation group(P<0.05).No significant difference was observed in SCr [(33.33±6.46) and(32.06±8.74) μmol/L] and BUN [(6.02±1.27) and(6.93±3.28) mmol/L] levels between the two groups on days 14 and 21(P<0.05).PAS staining results showed that kidney injury started on day 1 and was the severest on day 3,while kidney repair started on day 7 and completed on day 21.Immunohistochemistry results showed that Trps1 was mainly expressed in kidney tubules of cortex in the sham operation group.In the I/R group,Trps1 expression in kidney tissue decreased significantly on day 1 after I/R(P<0.05),was weak on day 3(P<0.05),started to increase on days 7 and 14 but still had significant difference(P<0.05),and returned to the same level as the sham operation group on day 21(P>0.05).The expression of Trps1 was negatively correlated with kidney tubule injury(P<0.05).Conclusion Trps1 shows upregulated expression during kidney repair after acute kidney injury,and is negatively correlated with injury degree.Trps1 may play a positive role in kidney repair.