呼吸道合胞病毒肾病大鼠肾脏乙酰肝素酶基因表达及其与尿蛋白的相关性

Expression of Heparanase in Kidney of Rats with Respiratory Syncytial Virus Nephropathy and Its Relationship with Proteinurina

目的研究乙酰肝素酶(heparanase,Hpa)在大鼠呼吸道合胞病毒(respiratory syncytial virus,RSV)肾病发病机制中的作用。方法将SD大鼠随机分为RSV肾病模型4d(RSV4)、8d(RSV8)、14d(RSV14)、28d(RSV28)组和正常对照组,建立RSV肾病大鼠模型。检测24h尿蛋白定量,采用免疫组织化学和实时荧光定量RT-PCR检测各组肾脏Hpa表达,分析Hpa表达水平与24h尿蛋白定量之间的相关性。结果与正常对照组相比,各实验组RSV肾病大鼠24h尿蛋白定量增加(P<0.05),且RSV14>RSV8>RSV28>RSV4(P<0.05);各实验组肾小球内Hpa蛋白表达增加(P<0.05),RSV8与RSV14组肾小球内Hpa蛋白表达高于RSV4和RSV28组(P<0.05),RSV8与RSV14组之间、RSV4和RSV28组之间差异无统计学意义,RSV肾病大鼠肾小球内Hpa蛋白表达与24h尿蛋白定量之间呈直线正相关(r=0.783,P<0.05);各组RSV肾病大鼠肾脏Hpa mRNA升高(P<0.05),且RSV14>RSV8>RSV4>RSV28(P<0.05),HpamRNA表达与24h尿蛋白定量之间呈直线正相关(r=0.725,P<0.05)。结论 Hpa在大鼠RSV肾病蛋白尿发生发展中可能发挥重要作用。

Objective To explore the role of heparanase in the pathogenesis of respiratory syncytial virus （RSV） nephropathy in rats model. Methods Twenty 150-200 g Sprague-Dawley （SD） rats （n=5 per group） were inoculated with 6×10^6 PFU RSV and sacrificed on days 4,8,14 and 28 postinoculation （RSVI, RSVs, RSVH and RSV28）. Five SD rats inoculated with Dulbecco＇s minimum essential medium were served as normal control. The expression levels of heparanase protein and mRNA in the rat renal tissue of each group were determined by immunohistochemical staining and real-time quantitative RT-PCR respectively. The proteinurina was also measured and then the relationship between the expression level of heparanase and the 24-hour urinary protein was studied. Results The rats with RSV nephropathy exhibited higher proteinuria in comparison with normal rats, and the 24- hour urinary protein level was significantly different between each RSV nephropathy group （RSV14 〉 RSV8 RSV28 〉RSV4 , P〈0.05）. Compared with normal control, the rats with RSV nephropathy showed up-regulated expression of heparanase protein in glomeruli. The expression levels of heparanase protein in RSV8 and RSV14 group were higher than those in RSV.I and RSVz8 group （P〈0.05）. There was a linear positive correlation between the expression level of glomerular heparanase protein and the quantity of 24-hour urinary protein （r= 0. 783, P（0.05）. Compared with normal control group, the expression levels of heparanase mRNA in the kidney from RSV4, RSV8, RSV, and RSV28 group were elevated （RSV14〉RSV8 〉RSV4〉RSV28, P〈0. 05）. There was a linear positive correlation between the expression level of renal heparanase mRNA and the quantity of 24-hour urinary protein （r=0. 725,P〈0.05）. Conclusion The increased expression of heparanase in kidney may be important to the loss of glomerular negative charge in glomerular basement membrane which is involved in the pathogenesis of RSV nephropathy in rats.