Validation of adenovirus-mediated overexpression of PKB, Stat5a, or c-MYC in dispersed adult human islets. A: Immunoblots of indicated proteins in islets not transduced (Uninfected) or transduced with a control adenovirus expressing GFP (Ad.GFP) or adenoviruses expressing constitutively active Akt/PKB, Stat5a, or c-MYC (all at 300 MOI for 96 h). Note that each of the three proteins is expressed efficiently and that Akt/PKB and Stat5 undergo appropriate phosphorylation. B: Immunofluorescent labeling of indicated proteins in islets after viral transduction. Compared with islets transduced with Ad.GFP (left), islets transduced with Akt/PKB, Stat5a, or c-MYC adenoviruses (right) display marked increases in the three molecules in several islet cell types, notably insulin-positive (β) cells. Also note that some β-cells display nuclear labeling of Stat5a or c-MYC. Scale bar = 25 μm. Both A and B are representative of five separate experiments from different islet donors.