基于AMPK/Nrf2信号通路研究黏菌素肾毒性的分子机制及黄连素的干预作用

近年来，黏菌素已成为治疗动物及人类多重耐药革兰氏阴性细菌感染的最重要的抗菌药物之一。肾毒性是黏菌素临床用药的主要毒副作用，严重影响其治疗指数并限制其应用。深入理解黏菌素肾毒性的分子机制、开发有效的减毒策略、提高治疗指数已成为黏菌素临床应用亟待解决的问题。我们前期通过对天然活性小分子化合物库进行高通量筛选并进一步证实黄连素可显著改善黏菌素诱导的肾细胞毒性及小鼠肾组织损伤。以此为线索，本课题将围绕AMPK/Nrf2信号通路，采用基因沉默、基因过表达和转基因小鼠等技术手段，从动物、细胞及分子水平探究AMPK和Nrf2基因功能获得和缺失如何调控黏菌素诱导的细胞氧化应激、线粒体功能失调及凋亡性死亡，以及如何调控黄连素的干预作用，从而揭示AMPK/Nrf2信号通路在黏菌素肾毒性中的作用及黄连素的干预机制。研究成果可为兽医临床黏菌素的安全用药、新应用开发和减毒策略提供理论依据。

Recently, colistin has become one of the most important antibacterial drugs for treatment of infections caused by multidrug-resistant gram-negative bacteria in animals and humans. The major adverse effect during colistin therapy is nephrotoxicity, which severely decreases its therapeutic index and thereby limits the applications. Deep understanding of the molecular mechanism of colistin-induced nephrotoxicity, development of effective strategies against colistin-induced nephrotoxicity and improvement of therapeutic index have raised concerns in the worldwide. Our preliminary screening results using a natural active compound library showed that berberine supplementation could significantly improve colistin-induced cytotoxicity and renal tissue damage in mice. Thus, this current project will investigate the precise molecular mechanism of AMPK/Nrf2 pathway in colistin-induced oxidative stress, mitochondrial dysfunction and apoptotic cell death in vivo and in vitro through the gain or loss of gene function based on gene silencing, overexpression and transgenic mice, respectively, so as to reveal the molecular mechanism of AMPK/Nrf2 signaling during colistin-induced nephrotoxicity and the targeted effect of berberine. Findings in this study will provide important theoretical basis for the safe use of colistin, development of new applications, and strategies against colistin-induced nephrotoxicity in veterinary medicine.