Figure 3. Monocyte-derived macrophages are resistant to apoptosis.

(A) Caspase-3 activity (n = 4–6) in IPF BALC with silencing of PGC-1α. BAL cells were isolated at indicated days after saline (n = 5/time point) or bleomycin exposure (n = 5/time point) from Akt1^fl/fl or Akt1^−/−Lyz2-cre mice. (B) TUNEL staining (n = 5) and (C) quantification (n = 5). Scale bar represents 40 μm. BAL cells were isolated 21 days after exposure. (D) Representative flow cytometry plots of monocyte-derived macrophages (MDM, CD45⁺CD11b^+/−Ly6G⁻CD64⁺Ly6c⁻Siglec F^low) and resident alveolar macrophages (RAM, CD45⁺CD11b^+/−Ly6G⁻CD64⁺Ly6c⁻Siglec F^hi) from saline or bleomycin-exposed Akt1^fl/fl and Akt1^−/−Lyz2-cre mice. Total cell number of (E) MDM (n = 5), (F) annexin V positive MDM (n = 5), (G) RAM (n = 5), and (H) annexin V positive RAM from Akt1^fl/fl and Akt1^−/−Lyz2-cre BAL (n = 5). **, p < 0.001; ***, p < 0.0001. Values shown as mean ± S.E.M. Two-tailed t-test statistical analysis was utilized for A. One-way ANOVA followed by Tukey’s multiple comparison test was utilized for C, E-H.