缬沙坦对cGVHD狼疮样肾炎小鼠肾组织中MMP-9／TIMP-1表达的影响

Effect of Valsartan on the expressions of MMP-9/TIMP-1 in kidney tissue of murine chronic graft-versus-host disease lupus nephritis

目的:观察缬沙坦对慢性移植物抗宿主病(cGVHD)狼疮样肾炎小鼠肾组织中基质金属蛋白酶-9(MMP-9)、组织金属蛋白酶抑制剂-1(TIMP-1)表达的干预作用,探讨缬沙坦对肾脏的保护机制。方法:18只B6D2F1代杂交鼠,随机分为狼疮肾炎模型组(12只)和对照组(6只)。随机将狼疮肾炎模型组分为模型组(6只)和缬沙坦组(6只)。双缩脲法测定24h尿蛋白量;免疫组织化学染色法及反转录-聚合酶链反应(RT-PCR)法观察肾组织中MMP-9、TIMP-1表达;明胶酶谱法检测MMP-9活性。结果:与对照组相比,狼疮肾炎模型组小鼠24h尿蛋白量、MMP-9、TIMP-1表达及比值均增加,MMP-9活性增强,且与系膜细胞增殖呈正相关;与模型组相比,缬沙坦组尿蛋白量、MMP-9、TIMP-1表达及比值均降低,MMP-9活性下降。结论:缬沙坦降低MMP-9、TIMP-1表达及MMP-9活性,改善MMP-9/TIMP-1失衡,从而发挥肾脏保护作用。

OBJECTIVE The aim of the present study was to determine whether Valsartan affects the expressions of matrix metalloproteinase-9（MMP-9）and tissue inhibitor of metalloproteinase-1 （TIMP-1）in kidney tissue of murine chronic graft-versus-host disease lupus nephritis and evaluate the renoprotective effect of Valsartan. METHODS Eighteen female age-matched （C57BL/6J × DBA/2） F1 mice were randomly divided into two groups., control mice and cGVHD mice. The cGVHD mice were randomly divided into two groups： untreated mice, treated mice with Valsartan. The levels of urinary protein were measured in the 24 h urine collections using the blure T. protein assay as a marker of renal damage. Immunohistochemistry and RT-PCR were used to observe the expressions of MMP-9, TIMP-1 in kidney tissue. Gelatin zymography was employed to perform MMP-9 activity examination. RESULTS Urinary protein excretion was increased significantly in cGVHD mice compared with the control mice. The cGVHD mice were found to have markedly intense staining of MMP-9, TIMP-1 mainly in tubular epithelial cells and walls of vessels. The level of glomerular MMP-9 staining correlated significantly with the level of total glomerular cell proliferation. The cGVHD mice displayed instinctively upregulated the ratio of MMP-9/TIMP-1 and increased MMP-9 activity. The treated mice had less proteinuria than untreated mice. The rate of MMP-9/TIMP-1 and gelatinolytic activity of MMP-9 in treated-mice were significantly reduced. CONCLUSION The imbalance of MMP-9 and TIMP-1 will lead to the regression of renal in lupus nephritis. Valsartan plays an important role in the regulation of the balance of MMP-9 and TIMP-1, which will prevent progressive kidney failure of lupus nephritis.