建立重症狼疮性肾炎模型并探索其与足细胞蛋白nephrin、P-cadherin的相关性

Establishment of a model of severe lupus nephritis and exploration of its correlation with podocyte proteins nephrin and P-cadherin

目的建立重症MRL/lpr小鼠狼疮性肾炎(lupus nephritis,LN)动物模型,并对模型成功与否进行验证,进一步探索狼疮性肾炎与足细胞蛋白nephrin、P-cadherin的相关性。方法将实验动物分为三组:空白组、模型组和脂多糖组。空白组为雌性C57小鼠8只,模型组及脂多糖组为雌性MRL/lpr小鼠各8只,其中脂多糖组腹腔注射脂多糖(lipopolysaccharide,LPS),空白组及模型组每周注射等量生理盐水。20周后检测小鼠尿蛋白,处死动物,收集各组小鼠肾组织。苏木精-伊红染色法(hematoxylin-eosin staining,HE)染色观察小鼠肾脏组织。RT-qPCR和Western blot检测肾组织中nephrin、P-cadherin的mRNA及蛋白表达。结果与空白组相比,模型组小鼠尿蛋白升高,肾脏病理损伤严重;与模型组相比,LPS组小鼠尿蛋白升高,肾脏损伤进一步加重;此外肾组织中nephrin、P-cadherin表达水平在三组间逐步下降(P<0.01)。结论用LPS腹腔注射的MRL/lpr小鼠可诱导加重狼疮,且狼疮性肾炎的严重程度与nephrin及P-cadherin相关。

Objective To establish the animal model of severe MRL/lpr mouse lupus nephritis(LN),and to verify the success of the model,so as to further explore correlation between LN and nephrin and P-cadherin of podocyte proteins.Methods Experimental animals were divided into three groups:blank group,model group and lipopolysaccharide group.There were 8 female C57 mice in the blank group,8 female MRL/lpr mice in the model group and 8 female MRL/lpr mice in the lipopolysaccharide group,the lipopolysaccharide group were injected intraperitoneally with lipopolysaccharide(LPS),while the blank group and the model group were injected with the same amount of normal saline every week.After 20 weeks,the urine proteins of mice were detected,the animals were killed,and the renal tissues of mice in each group were collected.And then,hematoxylin-eosin staining(HE)was used to observe the renal tissues of mice,and RT-qPCR and Western blot were used to detect the mRNA and protein expressions of nephrin and P-cadherin in renal tissues.Results Compared with the blank group,the urinary proteins in the model group increased and the pathological damage of kidney was serious;compared with the model group,the urinary proteins in the LPS group increased,and the renal injury was further aggravated.In addition,the expression levels of nephrin and P-cadherin in renal tissues decreased gradually among the three groups(P<0.01).Conclusion MRL/lpr mice injected intraperitoneally with LPS can induce and aggravate lupus,and the severity of lupus nephritis is related to nephrin and P-cadherin.