焦亡通路核因子κB/胱天蛋白酶-1在右美托咪定缓解糖尿病大鼠肾缺血再灌注后心肌易损性中的作用

Effect of pyroptosis pathway nuclear factorκB/cysteine aspartic acid specific protease-1 on myocardial vulnerability after renal ischemia reperfusion in diabetic rats with Dexmedetomidine

目的探讨焦亡通路核因子κB(NF-κB)/胱天蛋白酶-1(caspase-1)在右美托咪定(Dex)缓解糖尿病大鼠肾缺血再灌注后心肌易损性中的作用。方法选取8~12周龄的SPF级雄性Wistar大鼠30只,体重200~300 g,高脂喂养4周后腹腔注射1%链脲佐菌素(30 mg/kg)建立糖尿病模型。按随机数字表法将造模成功的动物分为对照组、模型组和Dex组,每组8只。模型组和Dex组建立肾缺血再灌注模型,对照组仅开腹,其中Dex组尾静脉以2μg/(kg·h)的速率于左肾缺血前30 min泵注Dex至再灌注后4 h,模型组和对照组同时泵注等量生理盐水。实验结束留取三组心肌和血清标本,采用酶联免疫吸附试验测定血清肌钙蛋白I(cTnI)、白细胞介素(IL)-1β、IL-18、IL-17a、IL-10、肿瘤坏死因子-α(TNF-α)水平,TUNEL染色测定心肌细胞凋亡率,蛋白质印迹法测定三组心肌组织NF-κB p65、p-NF-κB p65、caspase-1和GSDMD-N蛋白的表达。结果模型组IL-1β、IL-18、cTnI、TNF-α、IL-17a、p-NF-κB、caspase-1、GSDMD-N水平及心肌细胞凋亡率均高于对照组,IL-10水平低于对照组(P<0.05)。Dex组IL-1β、IL-18、cTnI、TNF-α、IL-17a、p-NF-κB、caspase-1、GSDMD-N水平及心肌细胞凋亡率均低于模型组,IL-10水平高于模型组(P<0.05)。结论Dex可降低糖尿病大鼠肾缺血再灌注后的心肌损伤,改善心功能,减少炎症因子释放,其机制可能与抑制心肌内焦亡蛋白表达有关。

Objective To investigate the role of nuclear factorκB(NF-κB)/cysteine aspartic acid specific protease-1(caspase-1)in Dexmedetomidine(Dex)in alleviating myocardial vulnerability after renal ischemia reperfusion in diabetic rats.Methods Thirty SPF male Wistar rats aged 8-12 weeks,weighing 200-300 g,were fed with high fat for four weeks and intraperitoneal injection of 1%Streptozotocin(30 mg/kg)was used to establish a diabetes model.The animals were divided into control group,model group,and Dex group with eight animals in each group.Renal ischemia reperfusion model was established in the model group and the Dex group,while the control group was laparotomy only.Dex was injected into the tail vein at a rate of 2μg/(kg·h)from 30 min before ischemia to 4 h after reperfusion in the left kidney in the Dex group,and the same amount of normal saline was injected into the model group and the control group simultaneously.At the end of the experiment,the myocardial and serum samples of the three groups were collected,and serum cardiac troponin I(cTnI),interleukin(IL)-1β,IL-18,IL-17a,IL-10,and tumor necrosis factor-α(TNF-α)levels were determined by enzyme-linked immunosorbent assay,and the apoptosis rate of cardiomyocytes was determined by TUNEL staining.The expressions of NF-κB p65,p-NF-κB p65,caspase-1,and GSDMD-N in myocardial tissues of the three groups were determined by Western blot.Results The levels of IL-1β,IL-18,cTnI,TNF-α,IL-17a,p-NF-κB,caspase-1,GSDMD-N,and apoptosis rate of cardiomyocytes in model group were higher than those in control group,and the levels of IL-10 were lower than those in control group(P<0.05).The levels of IL-1β,IL-18,cTnI,TNF-α,IL-17a,p-NF-κB,caspase-1,GSDMD-N,and apoptosis rate of cardiomyocytes in Dex group were lower than those in model group,and the levels of IL-10 were higher than those in model group(P<0.05).Conclusion Dex can reduce myocardial injury after renal ischemia-reperfusion in diabetic rats,improve cardiac function,and reduce the release of inflammatory factors,the mechanism of which may be related to inhibiting the expression of myocardial pyrogenic protein.