Novel Epidermal Growth Factor Receptor Inhibitor Attenuates Angiotensin II-Induced Kidney Fibrosis
作者:Y. Qian、K. Peng、C. Qiu、M. Skibba、Y. Huang、Z. Xu、Y. Zhang、J. Hu、D. Liang、C. Zou、Y. Wang、G. Liang
DOI:10.1124/jpet.115.228080
日期:2015.11.25
Chronic activation of renin-angiotensin system (RAS) greatly contributes to renal fibrosis and accelerates the progression of chronic kidney disease; however, the underlying molecular mechanism is poorly understood. Angiotensin II (Ang II), the central component of RAS, is a key regulator of renal fibrogenic destruction. Here we show that epidermal growth factor receptor (EGFR) plays an important role in Ang II–induced renal fibrosis. Inhibition of EGFR activation by novel small molecules or by short hairpin RNA knockdown in Ang II–treated SV40 mesangial cells in vitro suppresses protein kinase B and extracellular signal-related kinase signaling pathways and transforming growth factor- β /Sma- and Mad-related protein activation, and abolishes the accumulation of fibrotic markers such as connective tissue growth factor, collagen IV. The transactivation of EGFR by Ang II in SV40 cells depends on the phosphorylation of proto-oncogene tyrosine-protein kinase Src (c-Src) kinase. Further validation in vivo demonstrates that EGFR small molecule inhibitor successfully attenuates renal fibrosis and kidney dysfunction in a mouse model induced by Ang II infusion. These findings indicate a crucial role of EGFR in Ang II–dependent renal deterioration, and reveal EGFR inhibition as a new therapeutic strategy for preventing progression of chronic renal diseases.
肾素-血管紧张素系统(RAS)的慢性激活显著促进肾纤维化并加速慢性肾病的进展;然而,其潜在的分子机制尚不清楚。血管紧张素 II(Ang II)是 RAS 的核心成分,也是肾纤维生成破坏的关键调节因子。在这里,我们展示了表皮生长因子受体(EGFR)在Ang II 诱导的肾纤维化中的重要作用。通过新型小分子或短发夹 RNA 下调抑制 EGFR 的激活,在 Ang II 处理的 SV40 线粒体细胞体外抑制了蛋白激酶 B 和细胞外信号相关激酶信号通路,以及转化生长因子-β/Sma 和 Mad 相关蛋白的激活,并消除了结缔组织生长因子、胶原 IV 等纤维化标记物的积累。Ang II 在 SV40 细胞中对 EGFR 的转活化依赖于原癌基因酪氨酸激酶 Src(c-Src)激酶的磷酸化。进一步的体内验证表明,EGFR 小分子抑制剂在 Ang II 输注诱导的小鼠模型中成功减轻了肾纤维化和肾功能障碍。这些发现表明 EGFR 在 Ang II 依赖的肾脏恶化中发挥着关键作用,并揭示 EGFR 抑制作为预防慢性肾病进展的新治疗策略。