阳离子化牛血清白蛋白诱导膜性肾病模型大鼠足细胞相关蛋白的表达

Model rats with membranous nephropathy induced by cationic bovine serum albumin: expressions of related proteins in podocytes

背景:膜性肾病动物模型可模拟人类膜性肾病的发病机制,对疾病的研究具有重要意义。目的:观察膜性肾病模型大鼠足细胞相关蛋白nephrin、podocin的表达,以探讨其与膜性肾病发病的关系。方法:将40只SD大鼠随机分为模型组和对照组,每组20只。模型组取阳离子化牛血清白蛋白1 mg溶解于0.5 mL生理盐水中与等量不完全弗氏佐剂充分乳化后在颈背部皮下多点注射预免疫1周后正式免疫,尾静脉给予阳离子化牛血清白蛋白16 mg/kg,隔日1次,持续4周。对照组尾静脉注射等体积生理盐水。造模后第2,4周进行生化指标检测和病理学检查,RT-PCR法检测肾组织中nephrin和podocin mR NA的表达。结果与结论:(1)模型组24 h尿液总量明显减少,且出现了明显的蛋白尿,血清肌酐、尿素氮、胆固醇、三酰甘油水平显著升高,血清白蛋白水平显著降低,与对照组比较差异有非常显著性意义(P<0.01),且随着病变继续发展,病情加重;(2)病理检测发现模型组有不同程度肾小管扩张,肾小球基底膜增厚,系膜细胞及基质增生,呈典型的膜性肾炎改变;(3)模型组大鼠肾组织nephrin和podocin m RNA表达量低于对照组;(4)结果表明,nephrin、podocin表达减少可能使足细胞裂孔膜结构的完整性受损,肾小球滤过屏障破坏,导致蛋白尿。

BACKGROUND： Establishing the animal model of membranous nephropathy is of importance to figure out the pathogenesis of membranous nephropathy. OBJECTIVE： To investigate the expression of nephrin and podocin in the model of membrane nephropathy in rats, and to investigate their relationships with the pathogenesis of membranous nephropathy. METHODS： A total of 40 Sprague-Dawley rats were equivalently randomized into model and control groups. Rats in the model group were in premunity by given subcutaneous and multi-point injection of 1 mg cationic bovine serum albumin firstly dissolved in 0.5 m L normal saline and then fully emulsified with the equal incomplete Freund＇s adjuvant for 1 week, and 16 mg/kg cationic bovine serum albumin was injected via vein tails, once every other day for 4 weeks. The same volume of normal saline was injected into the controls. The mR NA expressions of nephrin and podocin in renal tissues were detected using real-time PCR, and biochemical indicators and morphological observation were measured at 2 and 4 weeks after modeling. RESULTS AND CONCLUSION：（1） In the model group, the total amount of urine and serum albumin levels were significantly decreased accompanying with overt proteinuria, and the serum creatinine, urea nitrogen, cholesterol and triglyceride levels were significantly increased all in a time-independent manner compared with the control group（P 0.01）, and the difference was significant（P 0.05）.（2） The pathological examination showed that rats in the model group had different degrees of renal tubular dilatation, glomerular basement membrane thickening, mesangial cells and stromal hyperplasia, which was typical of membranous nephritis.（3） Moreover, the m RNA expressions of podocin and nephrin in the model group were lower than those in the control group.（4） In conclusion, the decreased expressions of podocin and nephfin may disturb the integrity of the slit membrane of podocytes giving rise to the damage of glomerular filtration barrier, and proteinuria appears in final.