STING在失血性休克复苏大鼠急性肾损伤中的作用:与HIF-1α的关系

Role of STING in acute kidney injury induced by hemorrhagic shock and resuscitation in rats:relationship with HIF-1α

目的评价干扰素基因刺激蛋白(STING)在失血性休克复苏(HSR)大鼠急性肾损伤中的作用及其与缺氧诱导因子(HIF)-1α的关系。方法清洁级健康雄性SD大鼠36只,9~10周龄,体重350~400 g,按随机数字表法分为3组(n=12):假手术组(S组)、HSR组(H组)和HSR+C176组(HC组)。通过左侧股静脉放血回输法制备大鼠HSR模型。S组只行左侧股静、动脉穿刺置管术。H组和HC组在血液回输时经腹腔分别注射等量DMSO、C176(10 mg/kg)。于复苏后12 h时经主动脉采集血样,测定血清BUN和Scr浓度;随后处死大鼠取左肾,光镜下观察病理学结果并行肾损伤评分,TUNEL法检测肾细胞凋亡情况,免疫荧光染色法检测STING和HIF-1α的表达,Western blot法测定cleaved caspase-3、Bak和Bcl-2的表达,计算Bcl-2/Bak比值。结果与S组比较,H组和HC组血清BUN、Scr浓度和Paller评分升高,肾组织STING和HIF-1α表达上调,肾细胞凋亡率升高,肾组织cleaved caspase-3表达上调,H组Bcl-2/Bak比值降低,HC组Bcl-2/Bak比值升高(P<0.05);与H组比较,HC组血清BUN、Scr浓度和Paller评分降低,肾组织STING表达下调,HIF-1α表达上调,肾细胞调亡率降低,HC组肾组织cleaved caspase-3表达下调,Bcl-2/Bak比值升高(P<0.05)。结论STING参与了HSR大鼠急性肾损伤的过程,与上调HIF-1α表达有关。

Objective To evaluate the role of stimulator of interferon genes(STING)in acute kidney injury induced by hemorrhagic shock and resuscitation(HSR)and the relationship with hypoxia-inducible factor(HIF)-1αin rats.Methods Thirty-six clean-grade healthy male Sprague-Dawley rats,aged 9-10 weeks,weighing 350-400 g,were divided into 3 groups(n=12 each)by a random number table method:sham operation group(S group),HSR group(H group),and HSR plus C176 group(HC group).Hemorrhagic shock was induced by blood withdrawal from the left femoral vein followed by retransfusion in anesthetized rats.Left femoral arteries and veins were only cannulated in group S.In H group and HC group,the equal volume of DMSO and C176(10 mg/kg)was intraperitoneally injected,respectively,during blood retransfusion.Blood samples were collected from the aorta at 12 h after resuscitation for determination of serum blood urea nitrogen(BUN)and creatinine(Scr)concentrations.Then the rats were sacrificed,and the left kidney was removed for examination of the pathological changes of renal tissues(with a light microscope)which were scored and for determination of apoptosis in renal cells(by TUNEL),expression of STING and HIF-1α(by immunofluorescent staining),and expression of cleaved caspase-3,Bak and Bcl-2(by Western blot).Bcl-2/Bak ratio was calculated.Results Compared with group S,the serum BUN and Scr concentrations and Paller scores were significantly increased,the expression of STING and HIF-1αin renal tissues was up-regulated,the apoptosis rate of renal cells was increased,and the expression of cleaved caspase-3 in renal tissues was up-regulated in H group and HC group,and Bcl-2/Bak ratio was significantly decreased in group H,and Bcl-2/Bak ratio was significantly increased in group HC(P<0.05).Compared with group H,the serum BUN and Scr concentrations and Paller scores were significantly decreased,the expression of STING in renal tissues was down-regulated,the expression of HIF-1αin renal tissues was up-regulated,and the apoptosis rate of renal cells was decreased,the expression of cleaved caspase-3 was down-regulated,and the Bcl-2/Bak ratio was increased in group HC(P<0.05).Conclusion STING is involved in the process of acute kidney injury induced by HSR,which is related to up-regulating HIF-1αexpression in rats.