来氟米特对慢性移植物抗宿主病狼疮样小鼠肾组织BMP-7、TGF-β1表达的影响

Effects of Leflunomide on Expression of Bone Morphogenetic Protein-7,Transform Growth Factor-β1 in Renal Tissue of Murine Chronic Graft-versus-host Disease Lupus Nephritis

目的观察来氟米特对慢性移植物抗宿主病(cGVHD)狼疮样小鼠肾组织中骨形成蛋白-7(BMP-7)、转化生长因子-β1(TGF-β1)表达的干预作用,探讨来氟米特对狼疮肾炎(LN)的保护机制。方法 B6D2F1杂交鼠随机分为4组(各组均n=6):正常对照组、模型组、泼尼松组和来氟米特组。建立cGVHD LN小鼠模型后,泼尼松组、来氟米特组分别给予相应药物灌胃,正常对照组、模型组给予等体积生理盐水灌胃。观察、比较各组小鼠的尿蛋白排泄率(UPE)、肾功能、肾脏病理改变以及肾组织中BMP-7、TGF-β1的表达情况。结果与正常对照组相比,模型组小鼠UPE、尿素(BUN)、肌酐(Scr)显著升高,肾脏病理改变明显加重,BMP-7表达显著减少、TGF-β1表达显著增加(P<0.01)。与模型组相比,泼尼松组、来氟米特组UPE、BUN、Scr显著降低,肾脏病理明显改善,BMP-7表达增加、TGF-β1表达减少(P<0.05或0.01)。狼疮样模型小鼠肾组织中BMP-7表达水平与UPE、BUN、Scr均呈显著负相关(P均<0.01),TGF-β1表达水平与UPE、BUN、Scr均呈显著正相关(P均<0.01)。结论上调BMP-7、下调TGF-β1在肾脏的表达,可能是来氟米特对对LN的保护机制之一。

Objective To observe the intervention of leflunomide on the expression of bone morphogenetic protein-7（BMP-7） and transform growth factor-β1（TGF-β1） in kidney tissue of chronic graft-versus-host disease（cGVHD） murine lupus model,and eveluate the protective machanism of leflunomide.Methods Female（C57BL/6J×DBA/2） F1（B6D2F1） hybrids aged 8-10 weeks were randomly divided into four groups（n=6）： control group,model group,prednisone group and leflunomide group.The levels of 24 hrs urinary protein excretion（UPE） were measured by coomassie brilliant blue assay.The levels of blood urea nitrogen（BUN） and serum creatinine（Scr） were detected by automatic biochemical analyzer.The pathologic change of kidneys of each group were observed by light microscope after HE,PAS and Masson staining.Immunohistochemistry were taken to observe the expression levels of BMP-7 and TGF-β1 in kidney tissue.Results Comparing with the control group,UPE,BUN,Scr,cells number in glomeruli,glomeruloscloseis index and tubulointerstitial injury increased significantly in model group with markedly thinness staining of BMP-7 and intense staining of TGF-β1.Comparing with model group,prednisone group and leflunomide group displayed the up-regulating expression of BMP-7 and the down-regulating expression of TGF-β1,together with UPE,BUN,Scr,cells number in glomeruli,glomeruloscloseis index and tubulointerstitial injury decreased remarkably.The levels of UPE,BUN and Scr were relevant to BMP-7 expression in kidney negatively（P0.01） and TGF-β1 positively（P0.01）.Conclution The renal protective effect of leflunomide may be achieved by the up-regulation of BMP-7 expression and the down-regulation of TGF-β1 expression.