Figure 4.

Genetic Nrf2 gain of function increases β-cell proliferation ex vivo. Dispersed Keap1^lox/lox islets were transduced with Cre- or LacZ-expressing adenoviruses. A: After 72 h, RNA was isolated, and mRNA for Keap1, Nrf2, and known Nrf2 target genes were measured. B and C: Keap1^lox/lox islets were transduced with LacZ- or Cre-expressing adenoviruses and immunolabeled with insulin and Nrf2-p or insulin and Ki67 antibodies. D: Percentage of proliferating insulin-positive cells was calculated. E and F: Keap1^lox/lox islets were isolated and transduced with Cre or LacZ adenoviruses. After 24 h, RNA was extracted, and the expression of cell-cycle regulators or β-cell identity genes was measured. G: Keap1^lox/lox mice were crossed with Nrf2^lox/lox to make double-KO Keap1^lox/lox-Nrf2^lox/lox mice. H–J: Keap1^lox/lox-Nrf2^lox/lox or Keap1^lox/lox islets were isolated, transduced with Cre or LacZ adenoviruses, and stained for insulin and Ki67 (H) or were extracted for RNA and measured for expression of cyclins (I) and Nrf2 target gene (J) that produce NADPH. Percentage of Ki67-positive and insulin-positive cells was calculated. Data are mean ± SEM. *P < 0.05, **P < 0.005, ****P < 0.0001 compared with LacZ controls; #P < 0.0001 Cre-treated Keap1^lox/lox-Nrf2^lox/lox compared with Cre-treated Keap1^lox/lox.