白细胞介素18结合蛋白对多柔比星肾病模型小鼠的疗效

目的 探讨IL-18结合蛋白(IL-18BP)通过结合内源性IL-18抑制下游致炎因子释放,对多柔比星(ADR)微小病变型肾病模型小鼠的治疗作用.方法 雄性昆明种小鼠,一次性尾静脉注射ADR 7.5 mg·kg-1进行造模,正常对照组注射同等量的9 g·L-1盐水.于ADR造模后第5、7、12、21天分别注射鼠源性IL-18BP 0.5 mg·kg-1(IL-18BP治疗组)或等量PBS(非治疗组).隔周检测尿蛋白1次,观察并记录其体征.42 d后心脏采血处死小鼠,分离血清检测相关细胞因子和生化指标,并在电镜下对肾脏组织病理改变进行观察.结果 1.注射ADR造模后小鼠均出现肾病综合征表现,以大量蛋白尿、低蛋白血症、高胆固醇血症为特征.2.动态24 h尿蛋白定量:非治疗组与正常对照组及IL-18BP治疗组比较明显升高,差异具有统计学意义(Pa<0.01).3.血液生化:非治疗组血清中三酰甘油(TG)、胆固醇(CH)明显高于正常对照组、IL-18BP治疗组(Pa<0.01),总蛋白(TP)、清蛋白(ALB)明显低于后两组(Pa<0.01);BUN、血肌酐(SCr)水平各组间差异无统计学意义(Pa>0.05).4.细胞因子检测:IL-18BP治疗组与非治疗组比较IL-18及下游细胞因子IFN-γ、TNF-α水平均明显降低(Pa<0.05),IL-4水平有所回升(P<0.01).5.病理观察:电镜下非治疗组小鼠肾脏足突细胞完全融合或消失,IL-18BP治疗组小鼠肾脏组织学改变显著减轻,足突细胞仅部分融合.结论 内源性IL-18作为Th1型上游细胞因子在ADR肾病的形成中发挥重要作用,有可能作为关键致病因子影响病情的发展与转归.IL-18BP可通过特异性结合内源性IL-18,抑制Th1细胞介导的免疫反应,对ADR肾病发挥治疗作用,从而调节免疫平衡,改善肾脏功能.

Effect of Interleukin-18 Binding Protein on Adriamycin Nephropathy Model Mice

Objective To explore the experimental therapeutic effect of interleukin-18 binding protein(IL-18BP) through binding endogenous IL-18 inhibit downstream inflammation factors releasing on adriamycin(ADR)-induced nephropathy in mice. Methods Kunming mice were induced to nephropathy model by single injection of ADR(7.5 mg·kg~-1) through tail vena.Then the mice were treated with murine-IL-18BP with 0.5 mg·kg~-1 as the IL-18BP-treated group,and the mice were treated with phosphate buffered saline(PBS) of the same volume as the ADR-minimal change nephropathy(MCN) group on day 5,7,12 and 21.Urine protein was measured biweekly and objective sign of mice were recorded.All mice were sacrificed through getting blood from the heart on the 42~th day after the first injection of ADR.The renal histological changes were observed under electron microscope when mice were sacrificed. Results 1.All ADR-mice develo-ped nephropathy characterized by proteinuria,hypoalbuminemia,hypercholasterolnemia,and progressive renal injury.2.In IL-18BP-treated group,the urine protein rates decreased significantly compared with those in ADR-MCN group,but increased significantly compared with those in normal control group(P_a<0.01).3.In ADR-MCN group,the levels of tiglyceride and cholesterol were higher,and total protein and albumin were lower than those in IL-18BP-treated group and normal control group in serum(P_a<0.01).There were no significant diffe-rence among three groups of the levels of blood urea nitrogen and serum creatinine(P_a>0.05).4.In IL-18BP-treated group,the levels of IL-18,interferon-γ(IFN-γ) and tumor necrosis factor-α(TNF-α) in serum decreased significantly compared with those in ADR-MCN group(P_a<0.05),the level of IL-4 rose again(P<0.01).5.In ADR-MCN group,glomerulus epithelical cells were hologamy or vanished,yet there were only meromixis in IL-18BP-treated group by transmission electron microscope. Conclusions IL-18 and its downsteam cytokines(IFN-γ,TNF-α) may play important roles in the formation of the mice with ADR-induced nephropathy.It may be a key pathogenic factor affect the growth of the disease and outcome.IL-18BP has obvious therapeutic effect on ADR nephrosis mice through specific binding IL-18,therefore regulates immunologic balance,and strengthens renal function.