Figure 6

AMPK activator metformin activates Parkin-independent autophagy and improves bacterial killing in lungs of sepsis-immunosuppressed mice. (a) Outline of therapeutic dosing for metformin in sepsis-immunosuppressed mice followed by bacterial pneumonia. (b) CFUs from lung homogenates of indicated groups of mice. Mean ± s.e.m., n = 5 per control, post-sepsis and post-sepsis mice treated with metformin (Met.) groups. *P < 0.05, ANOVA. (c) Representative Western blots and quantitative analysis of (d) Parkin, (e) p-AMPK, and (f) pSer93-Beclin-1 from lung homogenates of control and sepsis-immunosuppressed mice. Data presented as mean ± s.e.m., n = 5–6. *P < 0.05, ANOVA. (g) Western blot analysis of pThr172-AMPK and pSer79-ACC and β-actin in monocytes from healthy donors and patients that survive shock (24 h after shock). Mean ± s.e.m., n = 3 (healthy donors), n = 4 (post-shock). *P < 0.05, Student’s t-test. (h) CFUs obtained after monocytes (shock) were incubated with or without metformin (1 mM) for 2.5 h. Mean ± s.e.m., n = 3 (patients) with three technical repetitions. *P < 0.05, Student’s t-test.