呼吸道合胞病毒肾病大鼠肾小球阴离子位点及肾脏乙酰肝素酶表达的变化

Alteration of glomerular anionic sites and expression of renal heparanase in respiratory syncytial virus nephropathy in rats

目的 观察呼吸道合胞病毒（RSV）肾病大鼠肾小球阴离子位点及肾脏乙酰肝素酶（Hpa）表达的变化,探讨肾脏Hpa在RSV肾病大鼠蛋白尿发生中的作用.方法 建立RSV肾病大鼠模型.将25只SD大鼠随机分为RSV肾病模型4 d（RSV4）组、8 d（RSV8）组、14 d（RSV14）组、28 d（RSV28）组和正常对照组,检测24 h尿蛋白定量和血生化指标,组织化学电镜检测肾小球阴离子位点,免疫组织化学检测肾脏Hpa表达,并分析其与24 h尿蛋白定量间的相关性.结果 RSV14组、RSV8组、RSV28组、RSV4组和正常对照组24 h尿蛋白分别为（30.9860±3.3464） mg、（15.3212±1.2249）mg、（13.9193±2.1409） mg、（11.5857±1.5705） mg、（3.9780±0.6224） mg,各实验组24h尿蛋白较正常对照组增加（P＜0.05）.RSV14组外周血清蛋白降低.各实验组肾小球阴离子位点较正常对照组减少（P＜0.05）；阴离子位点数/1000 nm肾小球基底膜在RSV14组、RSV8组、RSV28组、RSV4组和正常对照组分别为12.0000±1.5811、14.0000±1.0000、14.6000±1.1401、16.8000±0.8366、21.2000±1.3038.各实验组肾小球Hpa表达较正常对照组增加（P＜0.05）,RSV14组、RSV8组、RSV28组和RSV4组肾小球Hpa分别为0.6622±0.1145、0.5511±0.0257、0.3524±0.0296、0.4521±0.0087,RSV8组与RSV14组肾小球Hpa表达高于RSV4组和RSV28组.RSV肾病大鼠肾小球Hpa表达与24 h尿蛋白呈正相关（r=0.783,P＜0.05）.结论 肾脏Hpa表达增加导致RSV肾病大鼠肾小球基底膜电荷屏障破坏,促进蛋白尿发生.

Objective To observe the alteration of glomerular anionic sites and renal heparanase （Hpa）expression in respiratory syncytial virus（RSV） nephropathy in rats,and to investigate the role of Hpa in the pathogenesis of proteinuria in RSV nephropathy.Methods Twenty-five Sprague-Dawley （SD） rats were inoculated with 6 x 106plaque forming units（PFU） RSV and were sacrificed on days 4,8,14 and 28 post-inoculation（RSV4,RSV8,RSV14 and RSV28 group）.Five normal SD rats served as normal control.The proteinuria and serum parameters were measured.Glomerular anionic sites were measured by histochemical electron microscopy.The expression of Hpa in kidney was determined by immunohistochemical staining.The relationship between the expression level of Hpa and the quantity of 24-hour urine protein was studied.Results After inoculation,the proteinuria increased,especially in RSV14 group.The 24-hour urine protein of RSV14 group,RSV8 group,RSV28 group,RSV4 group and normal group were （30.9860 ± 3.3464）mg,（15.3212 ± 1.2249） mg,（13.9193-2.1409） mg,（11.5857± 1.5705） mg,（3.9780 ± 0.6224） rag,respectively.The serum albumin of RSV14 group decreased.The anionic sites of glomerular basement membrane（GBM） decreased in RSV nephropathy.The number of anionic sites per 1000 nm GBM of RSV14 group,RSV8 group,RSV28 group,RSV4 group and normal control group were 12.0000 ± 1.5811,14.0000 ± 1.0000,14.6000 ± 1.1401,16.8000 ± 0.8366 and 21.2000 ± 1.3038,respectively.Hpa in glomeruli couldn＇t be detected in normal rats.Glomerular Hpa expression was up-regulated in RSV nephropathy.The expression of glomerular Hpa of RSV14 group,RSV8 group,RSV28 group and RSV4 group were 0.6622 ±0.1145,0.5511 ± 0.0257,0.3524 ± 0.0296 and 0.4521 ± 0.0087,respectively.The expression level of Hpa in RSV8 group and RSV14 group was higher than that in RSV4 group and RSV28 group.There was a linear positive correlation between the expression level of glomerular Hpa and the quantity of 24-hour urine protein （r =0.783,P ＜ 0.05）.Conclusions The increased expression of glomerular Hpa in RSV nephropathy of rats leads to loss of the glomerular anionic sites and damage of the electrostatic barrier of GBM,which promote the proteinuria.