右美托咪定减轻大鼠肾缺血再灌注损伤中的作用机制研究

Study on the mechanism of interleukin 17A in dexmedetomidine attenuating renal ischemia-reperfusion injury in rats

目的探讨白介素-17A(IL-17A)在右美托咪定减轻大鼠肾缺血再灌注损伤中的作用机制。方法2018年8月—2019年1月于新疆医科大学第六附属医院进行实验。清洁级Wistar大鼠45只,采用随机数字表法分为3组,假手术组(sham组,n=15),切除右肾,不夹闭左侧肾蒂;缺血再灌注组(IRI组,n=15)、右美托咪定干预组(IRI+DEX组,n=15),建立大鼠肾缺血再灌注损伤模型。观察大鼠肾脏病理变化,肾小管上皮细胞凋亡情况,比较各组大鼠肾组织匀浆中血肌酐(SCr)和血尿素氮(BUN)以及血清IL-17A、TNF-α的水平,检测肾脏组织IL-17A、mTOR、NF-κB、AMPK表达水平。结果Sham组镜下肾脏结构大体正常;IRI组镜下部分肾间质空泡变性、水肿伴充血、出血,肾小管上皮细胞肿胀、脱落,部分肾小管坏死明显;IRI+DEX组镜下少部分肾间质空泡变性、水肿,局灶肾小管坏死,肾小球未见明确改变。Sham组镜下观察发现凋亡细胞少,凋亡指数为(6.296±0.852)%;IRI组凋亡细胞明显增多,凋亡指数为(25.927±1.597)%,较Sham组肾小管细胞凋亡明显增多(q=47.536,P=0.000);IRI+DEX组凋亡指数为(7.158±0.749)%,较IRI组凋亡细胞明显减少,凋亡指数降低(q=45.448,P=0.000)。IRI组大鼠肾脏组织匀浆中BUN、Cre水平较Sham组显著升高(q/P=12.514/0.000、3.259/0.007);与IRI组比较,IRI+DEX组BUN、Cre水平显著降低,差异具有统计学意义(q/P=11.458/0.000、2.638/0.035)。IRI组大鼠血清IL-17A、TNF-α水平较Sham组显著升高(q/P=12.623/0.000、13.037/0.000);与IRI组比较,IRI+DEX组血清IL-17A、TNF-α显著降低(q/P=10.388/0.000、10.460/0.000)。IRI组肾脏组织IL-17A、NF-κB、AMPK基因表达水平较Sham组显著升高,mTOR显著降低(q/P=10.441/0.000、6.722/0.000、2.649/0.034、10.110/0.000);与IRI组比较,IRI+DEX组肾脏组织IL-17A、NF-κB基因表达水平显著降低,mTOR显著升高(q/P=6.262/0.000、3.608/0.002、6.010/0.000)。结论右美托咪定可能通过降低IL-17A表达,抑制NF-κB通路的活化,激活mTOR信号通路,改善炎性反应及细胞凋亡,从而保护肾缺血再灌注损伤。

Objective To explore the role of interleukin 17A(IL-17A)in dexmedetomidine attenuating renal ischemia-reperfusion injury in rats.Methods The experiment was conducted in the Sixth Affiliated Hospital of Xinjiang Medical University from August 2018 to January 2019.Forty-five clean Wistar rats were divided into 3 groups by random number table method.The sham operation group(sham group,n=15),the right kidney was removed without clamping the left renal pedicle;the ischemia-reperfusion group(IRI group,n=15),dexmedetomidine intervention group(IRI+DEX group,n=15),establish a rat renal ischemia-reperfusion injury model.Observe rat kidney pathological changes,renal tubular epithelial cell apoptosis,compare the serum creatinine(SCr)and blood urea nitrogen(BUN),serum IL-17A,TNF-αlevels,kidney tissue IL-17A,mTOR,NF in each groupκB,AMPK expression level.Results The structure of the kidney under microscope in the Sham group was generally normal.In the IRI group,under the microscope,some renal interstitial vacuoles were degenerated,edema accompanied by congestion and bleeding,renal tubular epithelial cells swelled and fell off,and some renal tubular necrosis was obvious.In the IRI+DEX group,a small part of the renal interstitium had vacuolar degeneration,edema,focal renal tubular necrosis,and no clear changes in the glomeruli under the microscope.Observation under the microscope in Sham group showed that there were few apoptotic cells,and the apoptosis index was(6.296±0.852)%.The number of apoptotic cells in the IRI group was significantly increased,with an apoptotic index of(25.927±1.597)%,which was significantly more than that in the Sham group(q=47.536,P=0.000).The apoptotic index in the IRI+DEX group was(7.158±0.749)%,which was significantly less apoptotic cells than the IRI group,and the apoptotic index decreased(q=45.448,P=0.000).The levels of BUN and Cre in the kidney tissue homogenate of the IRI group were significantly higher than those in the Sham group(q/P=12.514/0.000,3.259/0.007).Compared with the IRI group,the BUN and Cre levels in the IRI+DEX group were significantly reduced,and the difference was statistically significant(q/P=11.458/0.000,2.638/0.035).Serum IL-17A and TNF-αlevels in IRI group were significantly higher than those in Sham group(q/P=12.623/0.000,13.037/0.000).Compared with the IRI group,the serum IL-17A and TNF-αin the IRI+DEX group were significantly reduced,and the difference was statistically significant(q/P=10.388/0.000,10.460/0.000).The expression levels of IL-17A,NF-κB and AMPK genes in the kidney tissue of the IRI group were significantly higher than that of the Sham group,and mTOR was significantly lower(q/P=10.441/0.000,6.722/0.000,2.649/0.034,10.110/0.000).Compared with the IRI group,the expression levels of IL-17A and NF-κB genes in the kidney tissue of the IRI+DEX group were significantly reduced,and mTOR was significantly increased(q/P=6.262/0.000,3.608/0.002,6.010/0.000).Conclusion Dexmedetomidine may reduce the expression of IL-17A,inhibit the activation of the NF-κB pathway,activate the mTOR signaling pathway,and improve the inflammatory response and apoptosis,thereby protecting renal ischemia-reperfusion injury.