FIGURE 5.

Akt mediates macrophage cell survival. A, representative images of apoptotic nuclear TUNEL staining in macrophages expressing empty and phMGFP-empty vectors or Akt and phMGFP-empty vectors. Cells were treated with 10 μm DGBP or vehicle for 16 h. B, quantitative analysis of A expressed as a ratio of number of TUNEL-positive and GFP-positive cells to the total number of GFP-positive cells. Counts were conducted on five different fields within each group. *, p < 0.001 versus empty and versus Akt. C, caspase-3 activity was determined in macrophages overexpressing Rac1_WT or Rac1_CA and co-expressing empty or Akt. Macrophages were incubated with DGBP or vehicle (n = 8). *, p < 0.0001 versus Rac1_WT (Empty); **, p < 0.0001 versus Rac1_CA (Empty); #, p < 0.0001 versus Rac1_WT (Empty); ## p < 0.0001 versus Rac1_CA (Empty). D, macrophages expressing Akt were analyzed for caspase-3 activity in cells incubated in vehicle (ethanol) or 100 μm cholesterol for 24 h. n = 8. *, p < 0.0001 versus empty (Vehicle); **, p = 0.0008 versus empty (Vehicle). E, caspase-3 activity was measured in macrophages expressing empty or Akt vectors and either MDD_WT or MDD_S96A. n = 8. *, p < 0.0001 versus empty (Empty); **, p < 0.0001 versus MDD_WT (Empty); ***, p < 0.0001 versus MDD_WT (Empty). F, macrophages were transfected with empty or Rac1_WT vectors and treated with catalase (PEG-CAT) for 1 h or pretreated with PEG-CAT and then exposed to chrysotile for 30 min (n = 8). *, p < 0.0001 versus empty; **, p < 0.0425 versus Rac1_WT (Vehicle) and versus empty (Chrysotile); #, p < 0.0376 versus empty; ##, p < 0.0174 versus empty. G, caspase-3 activity was analyzed in BAL cells from WT (n = 4) and Akt^+/− (n = 4) mice. *, p < 0.0406 versus WT. Error bars, S.D.