Objective To determine the role of fosinopril and valsartan intervention in Klotho, matrix metalloproteinase-9 (MMP-9), tissue inhibitor of metalloproteinase-1 (TIMP-1) and plasminogen activator inhibitor (PAI-1) gene expression in hypertensive renal interstitial fibrosis (RIF) in the kidney tissue of spontaneously hypertensive rats (SHR). Methods We randomly divided 20 male 22-week-old SHR into 4 groups (5 in each group):a hypertension group (SHR group), a fosinopril group ［Fos group, 10 mg/( kg·d) gavage］, a valsartan group ［Val group, 10 mg/( kg·d) gavage］， and a fosinopril plus valsartan group ［Fos + Val group, fosinopril 10 mg/( kg·d) + valsartan 50 mg/( kg·d) gavage］. Another five 22-week-old male Wistar Kyoto rats (WKY) were used as controls. Through monitoring the weight of the rats, tail artery pressure, 24-hour urine protein by fosinopril and/or valsartan intervention after the 8-week trial. RT-PCR and Western blot were used to detect the mRNA and protein expression of Klotho, MMP-9, TIMP-1, and PAI-1 in the kidneys.Results RT-PCR showed that in the SHR group, Klotho mRNA and protein expression were significantly decreased(P＜0.01), while mRNA and protein expression of MMP-9, TIMP-1, and PAI-1 were significantly higher compared with the WKY group(P＜0.01). With fosinopril and / or valsartan intervention, Klotho mRNA expression in the Fos group (P＜0.01), Fos + Val group (P＜0.01), Val group (P＜0.05), Klotho protein expression in the Fos group(P＜0.05), Fos + Val group (P＜0.05), Val group (P＜0.01), were significantly increased compared with those in the SHR group. The mRNA and protein expression of MMP-9, TIMP-1, and PAI-1 in the Fos group, Val group, and Fos + Val group were significantly lower than those in the SHR group (P＜0.01). The expression of Klotho mRNA had negative correlation with the expression of MMP-9 mRNA (r= -0.864, P<0.01), TIMP-1 mRNA (r=-0.725, P<0.01) and PAI-1 mRNA (r=-0.785, P<0.01). The Klotho protein expression had negative correlation with the expression of MMP-9 protein (r=-0.614, P<0.05), TIMP-1 protein (r=-0.579, P<0.05), and PAI-1 protein (r=-0.552, P<0.05). Conclusion Anti-aging gene Klotho and the genes related with extracellular matrix degradation gene MMP-9, TIMP-1, PAI-1 are involved in hypertensive renal injury. The expression of Klotho and MMP-9, TIMP-1, and PAI-1 is closely correlated. Fosinopril and valsartan which increase the Klotho mRNA and protein expression can alter the expression of Klotho-MMPs/TIMPs, which may be the main mechanism to prevent interstitial fibrosis.%目的:观察自发性高血压大鼠(spontaneously hypertensive rats,SHR)肾脏组织中Klotho、基质金属蛋白酶-9(matrix metalloproteinase-9,MMP-9)、基质金属蛋白酶组织抑制剂-1(tissue inhibitor of metalloproteinase-1,TIMP-1)和纤溶酶原激活物抑制剂-1(plasminogen activator inhibitor,PAI-1)基因的表达状况,探讨其在高血压肾间质纤维化中的作用及福辛普利和缬沙坦的肾保护作用机制. 方法:22周龄雄性SHR 20只随机分为4组(每组5只):高血压组(SHR组)、fosinopril组[Fos组,10 mg/( kg·d)灌胃],Valsartan组[Val组,50 mg/( kg·d)灌胃]和fosinopril+valsartan组[Fos+Val组,fosinopril 10 mg/( kg·d)+valsartan 50 mg/( kg·d)灌胃].22周龄雄性Wistar Kyoto大鼠(WKY组)5只作为对照组.用药物干预连续喂养8周,分别用RT-PCR和Western 印迹检测肾脏组织中Klotho,MMP-9,TIMP-1和PAI-1 mRNA和蛋白的表达水平. 结果:SHR组肾脏组织Klotho mRNA和蛋白表达较WKY组明显下调(P＜0.01),而MMP-9,TIMP-1和PAI-1mRNA和蛋白的表达较WKY组均明显上调(P＜0.01);用fosinopril和/或valsartan干预后,可上调Klotho mRNA在Fos,Fos+Val组(P＜0.01)和Val组(P＜0.05)的表达,上调Klotho 蛋白在Val,Fos+Val组(P＜0.01)和Fos组(P＜0.05)的表达.同时下调MMP-9,TIMP-1,PAI-1 mRNA和蛋白在Fos,Val,Fos+Val组的表达(P＜0.01).相关分析表明:Klotho mRNA和蛋白的表达与MMP-9,TIMP-1,PAI-1 mRNA (r值分别为-0.864,-0.725和-0.785,P＜0.01)和蛋白(r值分别为-0. 614,-0.579和-0.552,P＜0.05)的表达均呈负相关. 结论:高血压肾损害与抗衰老基因Klotho和基质降解相关基因MMP-9,TIMP-1,PAI-1关系密切;Klotho基因与MMP-9,TIMP-1和PAI-1基因的表达呈负相关.上调抗衰老基因Klotho表达的药物fosinopril 和/或valsartan可改善Klotho-MMPs/TIMPs-PAI-1的表达,这可能是其抗肾纤维化的重要机制.
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