自噬及相关AMPK/mTOR信号通路对多黏菌素E肾毒性调节作用机制研究

多药耐药G-菌是全球面临的严峻问题，有效药物屈指可数。多黏菌素E(colistin)作为耐药G-菌最后防线，抗菌效果肯定，但肾毒性机制始终未能明确，临床应用受限。课题组新近发现colistin诱导肾毒性时效应细胞多条自噬相关通路受到影响，其中以AMPK/mTOR通路最为显著，蛋白水平也确证自噬标记物LC3的形成显著增加。自噬是应激状态下细胞启动的溶酶体依赖性降解，对维持细胞存活起重要保护作用。基于此我们提出“以AMPK/mTOR通路为核心的自噬可能对colistin诱导的肾毒性具有调控作用”的设想，设计分子、细胞和特异性基因（mTORC1和AMPKα1）敲除大鼠系列试验，采用自噬诱导剂和抑制剂双向验证，力求阐明AMPK/mTOR及其他自噬关键蛋白ATG-5、Beclin-1等在colistin致肾损伤中的调控机制，发掘肾损伤保护新靶点，为临床更加安全有效应用colistin提供科学依据。

The world is facing a severe threaten of multidrug resistant (MDR) Gram-negative bacteria. Only a few effective antibiotics are available. Colistin is the last resort of antibiotics against MDR Gram-negative bacteria. Although its antimicrobial efficacy is excellent, nephrotoxicity of colistin is unavoidable. Despite decades history of this old antibiotic, the mechanism of colistin-induced nephrotoxicity remains unclear. We recently discovered that colistin can modulate multiple autophagy-related pathways in NRK-52E cells. Among them, the AMPK / mTOR pathway is most affected. LC3, marker of autophagy, is also significantly increased. Autophagy is a lysosomal-dependent degradation initiated by cells under stress, which plays an important role in maintaining cell survival. Based on our previous results, we assume that autophagy and AMPK/mTOR pathway may play a key role in colistin-induced renal injury. We design in vitro and specific gene (mTORC1 and AMPK α1) knockout mice in vivo experiments to elucidate the role of autophagy and AMPK/mTOR pathway in colistin-induced nephrotoxicity and explore renal protection strategies. This study will provide new ideas and methods for safe and rational clinical application of colistin.