AMPK信号通路在调节小鼠骨髓巨噬细胞抗菌性自噬效应中的作用

Role of AMPK signaling pathway in regulating antibacterial autophagy in murine bone marrow derived macrophages

目的观察AMP依赖的蛋白激酶(AMPK)对小鼠骨髓巨噬细胞自噬及杀菌活性的调节作用,并探讨其可能机制。方法分离和体外培养小鼠原代骨髓巨噬细胞(BMDM),观察大肠埃希菌刺激后对BMDM细胞自噬水平及AMPK活化状态的影响。使用AMPK激动剂和抑制剂干预其活化,进一步观察大肠埃希菌感染的BMDM细胞中AMPK活化、自噬水平以及杀菌能力的变化。结果大肠埃希菌感染后的小鼠BMDM细胞自噬相关分子LC3B和Beclin1的表达显著升高,同时LC3Ⅱ/Ⅰ比值也明显升高,且其AMPK的磷酸化水平也随之显著上调。AMPK活性增强后,能够进一步上调BMDM细胞的自噬水平以及对细菌的降解清除。而AMPK活性被抑制后,细胞自噬水平和杀菌活性均显著下降。结论 AMPK分子及其相关信号通路可能在调节巨噬细胞自噬水平以及抗菌效应方面发挥重要作用。

Objective To investigate the regulatory effects and possible mechanisms of autophagy induction and bactericidal activity in muring bone marrow derived macrophages （BMDMs）. Methods Murine BMDMs were isolated and cultured in vitro. Then standard strain of E. coli was used to infect BMDMs and cellular autophagy levels and AMPK activation were detected. We next modulated functions of AMPK by pretreating cells with the specific agonist or antagonist of AMPK. Then cellular AMPK activation, autophagy levels and bactericidal activity were observed after E. eoli infection. Results In E. coli infected BMDMs ,autophagy related molecules like LC3B and Beelinl were upregu- lated, accompanied with elevated LC3 Ⅱ/Ⅰ ratio. Phosphorylation of AMPK was also upregulated by E. coli treatment. Enhanced AMPK activi- ty by its agonist leads to increased cellular autophagy and bactericidal activity, whereas inhibition of AMPK by its suppressor downregulated autophagy and dampened bactericidal activity. Conclusion AMPK and its related signaling pathway is required for anti-bacterial response in macrophage, which is dependent on its function in npregulating autophagy related molecules and inducing autophagy.