葡萄球菌肠毒素B复合感染联合5/6肾切除建立免疫球蛋白A肾病肾小球硬化模型

Establishment of rat model of IgA nephropathy with glomerulosclerosis by Staphylococcal enterotoxin B injection combined with 5/6 nephroectomy

目的探讨免疫球蛋白A(IgA)肾病肾小球硬化模型的建立方法,为研究提供新的模型。方法将24只Sprague-Dawley大鼠随机分为假手术组、5/6肾切除组、葡萄球菌肠毒素B(SEB)复合感染组和SEB复合感染联合5/6肾切除组,每组6只。实验12周末观察尿红细胞计数、24h尿蛋白定量、血清尿素氮和肌酐水平,免疫荧光观察肾小球中IgA的表达,应用光学显微镜和透射电子显微镜分别观察大鼠肾组织结构及超微结构的情况,并采用免疫组织化学法检测转化生长因子(TGF)-β1在肾组织中的表达。结果 SEB复合感染联合5/6肾切除组的尿红细胞计数显著高于假手术组和5/6肾切除组(P值均<0.01),24h尿蛋白定量、血清尿素氮和肌酐水平显著高于假手术组和SEB复合感染组(P值均<0.01),肾小球系膜区可见大量IgA沉积,且强度较SEB复合感染组强,光学显微镜和透射电子显微镜可见大部分区域出现肾小球硬化伴系膜区电子致密物沉积,肾组织中TGF-β1表达显著高于假手术组和SEB复合感染组(P值均<0.01)。结论 SEB复合感染联合5/6肾切除制作的IgA肾病肾小球硬化模型在一定程度上符合人类的临床病理特点,可提供一种新的模型。

Objective To explore modeling methods of IgA nephropathy with glomerulosclerosis. Methods Twenty-four male Sprague-Dawley rats were randomly divided into sham operation group, 5/6 nephrectomy group, Staphylococcal enterotoxin B （SEB） infection group, and SEB infection combined with 5/6 nephrectomy group （n=6）. Red blood cell （RBC） count, 24-hour urinary protein, serum urea nitrogen （SUN） and creatinine （SCr） were detected at the end of the 12th week of the experiment. Immunofluorescence was applied to assay IgA expression in the glomerulus. Renal tissue structure and ultrastructure were observed under light microscope and transmission electron microscope, respectively. The expression of transforming growth factor-β1 （TGF-β1） in renal tissue was detected by immunohistochemical method. Results RBC count in the SEB infection combined with 5/6 nephrectomy group was significantly higher than those in the sham operation group and 5/6 nephrectomy group （both P〈0.01）. 24-hour urine protein, SUN, SCr and TGF-β1 in the SEB infection combined with 5/6 nephrectomy group were significantly higher than those in the sham operation group and SEB infection group （all P 〈 0. 01 ）. In the SEB infection combined with 5/6 nephrectomy group, mass IgA was found in glomerular mesangium, which was stronger than that in SEB infection group~ glomerular sclerosis was found in most areas under light microscope, and electron-dense matter was detected in mesangial region by transmission electron microscope. Conclusion IgA nephropathy with glomerulosclerosis is similar to human clinical pathological features by SEB infection combined with 5/6 nephroectomy in rat models, which provides a new model for research.