益肾通络方下调ADAM17介导的EGFR表达干预膜性肾病肾小管上皮细胞凋亡研究

Yishen Tongluo interferes with renal tubular epithelial cell apoptosis in membranous nephropathy by down-regulating ADAM17-mediated EGFR expression

目的探讨解整合素金属蛋白酶17(a disintegrin and metalloproteinase 17,ADAM17)介导的表皮生长因子受体(epidermal growth factor receptor,EGFR)激活与膜性肾病(membranous nephropathy,MN)肾小管上皮细胞凋亡的关系及益肾通络方的干预作用。方法尾iv阳离子牛血清白蛋白(cationic bovine serum albumin,C-BSA)构建MN大鼠模型,给予益肾通络方干预4周。实验结束后观察大鼠肾脏病理变化和肾小管上皮细胞凋亡情况;采用Western blotting和qRT-PCR法检测肾组织ADAM17、肝素结合性表皮生长因子(heparin-binding epidermal growth factor,HB-EGF)、肿瘤坏死因子-α(tumor necrosis factor-α,TNF-α)以及磷酸化表皮生长因子受体(phosphorylated epidermal growth factor receptor,p-EGFR)蛋白及mRNA表达情况。结果与对照组比较,模型组大鼠肾脏病理改变严重,肾小管上皮细胞凋亡增多(P<0.01),肾组织ADAM17、p-EGFR、HB-EGF、TNF-α蛋白及mRNA表达显著升高(P<0.01)。与模型组相比,益肾通络方组大鼠肾脏病理有所改善,肾小管细胞凋亡减少(P<0.01),肾组织ADAM17、EGFR、HB-EGF、TNF-α蛋白及mRNA表达显著降低(P<0.01)。结论MN大鼠肾组织ADAM17表达增多,释放活化HB-EGFR、TNF-α增多,进而激活相应受体EGFR,EGFR活化进一步诱导肾小管上皮细胞凋亡及肾脏纤维化。益肾通络方可以通过降低MN大鼠肾组织剪切酶ADAM17表达,减少HB-EGFR、TNF-α的脱落活化,从而减少EGFR激活,以达到减少肾小管上皮细胞凋亡、延缓肾脏纤维化的作用。

Objective To explore the relationship between a disintegrin and metalloproteinase 17(ADAM17)-mediated epidermal growth factor receptor(EGFR)activation and membranous nephropathy(MN)renal tubular epithelial cell apoptosis and the intervention effect of Yishen Tongluo Recipe(益肾通络方).Methods MN rats model was constructed by tail iv cationic bovine serum albumin(C-BSA),Yishen Tongluo Recipe was given for 4 weeks.After the experiment,the pathological changes of kidney and apoptosis of renal tubular epithelial cells in rats were observed.Western blotting and qRT-PCR were used to detect protein and mRNA expressions of ADAM17,heparin-binding epidermal growth factor(HB-EGF),tumor necrosis factor-α(TNF-α)and phosphorylation epidermal growth factor receptor(p-EGFR).Results Compared with control group,the pathological changes in kidneys of rats in model group were severe,the apoptosis of renal tubular epithelial cells were increased(P<0.01),protein and mRNA expressions of ADAM17,p-EGFR,HB-EGF and TNF-αin renal tissue were significantly increased(P<0.01).Compared with model group,the kidney pathology of rats was improved after the intervention of Yishen Tongluo Recipe,the apoptosis of renal tubular cells was reduced(P<0.01),protein and mRNA expressions of ADAM17,p-EGFR,HB-EGF and TNF-αwere decreased in renal tissue(P<0.01).Conclusion ADAM17 expression in kidney tissue of MN rats is increased,and more HB-EGFR and TNF-αare released and activated,then activate the corresponding receptor EGFR,the activated EGFR further induce apoptosis of renal tubular epithelial cells and renal fibrosis.Yishen Tongluo Recipe can reduce the shedding and activation of HB-EGFR and TNF-αby reducing the expression of cleaving enzyme ADAM17 in kidney tissue of MN rats,thereby reducing the activation of EGFR,so as to reduce the apoptosis of renal tubular epithelial cells and delay renal fibrosis.