Figure 2.

Autophagic activity is initially induced and then impaired during progression of neonatal hyperoxia-induced lung injury. GFP-LC3 mice were randomized to normoxia (N; 21% O₂) or hyperoxia (H; 75% O₂) exposure within 12 hours of birth and killed on P3, 5, or 7. (A) Left lung homogenates were analyzed for GFP, p62, Becn1 (Beclin 1), AMPK (5′-AMP–activated protein kinase), phospho-AMPK (p-AMPK), and phospho-S6 (p-S6) expression by IB. Relative protein concentrations of P3, P5, and P7 samples, normalized to ACTB, were determined by densitometry and are presented in B–D, respectively. Data are shown as mean ± SEM; n = 4 per group. *P < 0.05, **P < 0.01, and ***P < 0.001.