替米沙坦对大鼠肾小管上皮细胞尿酸盐转运蛋白表达的影响

Effect of telmisartan on the expression of urate transporter protein in the renal tubule epithelial cells

目的 观察替米沙坦干预对尿酸性肾病模型大鼠尿酸盐转运蛋白（UAT）表达的影响,探讨替米沙坦对尿酸性肾病的保护作用及机制.方法 （1）高尿酸（600μmol/L）＋不同浓度替米沙坦干预（10 nmol/L,100 nmol/L,1000 nmol/L,10000 nmol/L）,肾小管上皮细胞NRK-52E培养48 h后,采用荧光定量PCR及普通PCR检测UAT及TGF-β1 mRNA的表达,Western印迹及细胞免疫荧光检测UAT及rGF-β1、α-SMA蛋白的表达.（2）制备高尿酸大鼠模型：21只雌性Wistar大鼠随机分入正常对照组（Con）,高尿酸模型组（HU,氧嗪酸钾200 mg/kg加高尿酸饲料）,替米沙坦治疗组（Tel,替米沙坦10 mg/kg）.治疗4周后处死大鼠,抽取心尖血,检测Scr、BUN及血尿酸（UA）.肾脏组织冰冻切片,HE染色,光镜观察肾小管有无尿酸盐结晶沉积.Western印迹法检测UAT在肾组织中的表达.结果 （1）动物实验结果显示与对照组比较,高尿酸组显著抑制UAT mRNA表达（P＜0.01）;替米沙坦剂量依赖地拮抗高尿酸对UAT的抑制作用,并抑制高尿酸诱导的TGF-β1及α-SMA表达（均P＜ 0.05）.（2）细胞实验结果显示与HU组比较,替米沙坦可明显降低高尿酸大鼠的血尿酸水平（189.9 μmo]/L比204.5μmol/L,P＜ 0.05）,上调肾组织UAT的表达、下调TGF-β1表达（均P＜ 0.05）.结论 替米沙坦显著抑制肾小管上皮细胞TGF-β1及α-SMA表达,对尿酸性肾病肾脏纤维化有一定的保护作用,其机制可能与调节尿酸盐转运蛋白UAT表达有关.

Objective To explore the protective effect and underlying mechanism of telmisartan on hyperuricemic nephropathy.Methods （1）High level of uric acid （600 μmol/L） and telmisartan in different concentrations （10nmol/L,100 nmol/L,1000 nmol/L,10000 nmol/L） were added to renal tubule epithelial cells and cultured for 48 h,the expression of UAT,TGF-β1 and α-SMA were detected by Real-time PCR,RT-PCR,Western blotting or cell immunofluorescence.（2） Wister rats were randomly divided into normal control group（Con）,high uric acid group （HU）,and telmisartan treatment group （Tel）.Four weeks later,Scr,BUN and serum uric acid of the rats were detected.The expression of UAT in rat kidney was detected by Western blotting.Results （1）In vitro,compared to control group,high uric acid （600 μmol/L） inhibited the expression of UAT （P ＜ 0.01）,and the inhibition could be alleviated by telmisartan; Telmisartan inhibited the upregulation of TGF-β1 and α-SMA induced by high uric acid（all P ＜ 0.05）; （2）In vivo,compared to high uric acid group rats,telmisartan group rats had significantly reduced serum uric acid levels （189.9 μmol/L vs 204.5 μmol/L,P＜0.05）,upregulated UAT and downregulated TGF-β1 expression in rat kidney （all P＜ 0.05）.Conclusion Telmisartan significantly inhibits the upregulation of TGF-β1 and α-SMA induced by uricemia,which may prevent kidney from fibrosis.The protect effect of telmisartan may be related to the upregulation of UAT.