树突状细胞在多柔比星诱导的大鼠肾纤维化模型中的作用

摘要

目的 以多柔比星诱导肾纤维化大鼠为对象,探讨树突状细胞(DC)在慢性肾纤维化启动过程中的作用.方法 52只大鼠随机分为:对照组(n=20)、模型组(n=32).于第1、2周第1天给予多柔比星(4 mg/kg)尾静脉注射建立肾纤维化模型,对照组给予等量生理盐水,首次给药后第4、7、10、13周末收集血、尿标本,测定血甘油三脂、总胆固醇和白蛋白及24 h尿蛋白排泄率;应用Masson染色观察肾脏组织形态学变化,并计算肾小球硬化指数(GSI)及肾小管间质损伤指数(TII);应用免疫组化观察DC生物学标志(OX62)的变化;应用Western blot技术检测肾组织肝细胞生长因子(HGF)的表达.结果 与对照组相比,第7周末模型组血甘油三酯、总胆固醇升高(P＜0.01),白蛋白明显降低(P＜0.01),24 h尿蛋白排泄率明显增加(P＜0.01),且随实验时间呈逐渐上升趋势.光镜下观察,肾小球系膜基质明显增多,肾小管多灶性萎缩和扩张,管腔内可见蛋白管型,并随时间延长逐渐加重.GSI及TII逐渐升高(P＜0.05).于第7周肾间质OX62阳性细胞数量最多,后逐渐减少(P＜0.01).肾脏HGF表达4周时较对照组增加(P＜0.01),7周时开始降低,并随病程呈进一步降低.结论 DC可能参与慢性肾脏纤维化的启动过程,主要通过对免疫活性细胞和肾组织固有细胞及组织结构成分的影响发挥作用.%Objective To study the effect of dendritic cell(DC) in the startup procedure of chronic renal fibrosis by Doxorubicin-induced nephropathy. Methods 52 rats were divided into normal control group(n =20)and model group ( n = 32 ), model group was induced by tail intravenous injection of Doxorubicin (4 mg/kg) for two times at the 1st day of week 1,2 ,while control group received normal saline,blood and urine specimen were collected at week 4,7,10 and 13 respectively,the amount of serum triglycerides, total cholesterol, albumin and proteinuria was measured. The tinctorial renal histology was observed with light microscope, the extent of kidney damage were assessed by glomerulosclerosis index (GSI) and tubulointerstitial index ( TII), OX62 was observed by immunohistochemistry. The level of HGF was detected by semiquantit western blot. Results The amounts of serum triglycerides,total cholesterol and proteinuria in the model group significantly increased and albumin significantly decreased( P ＜0. 01 ) at the end of the 7th week compared with the normal control group ( P ＜ 0. 01 ). The proliferation of the mesangial cells, the accumulation of the extracellular matrix and atrophy of renal tubules were obviously observed. GSI and TII were increased gradually( P ＜ 0. 05 ). The amounts of OX62 had largest number in the 7th week (P ＜ 0. 01 ). The amounts of HGF increased at the end of the 4th week compared with the normal control group( P ＜0. 01 ) and began to increase from the 7th week. Conclusion DC may play a role by affecting immune competent cell,renal residential cells and structure component which involve in the startup process of chronic renal fibrosis.