Figure 3.

Nrf2 is necessary for HFD-mediated β-cell mass expansion. Pancreata from βNrf2KO mice fed an RD or HFD for 29 days were immunolabeled for insulin. A and B: β-Cell mass and islet morphometry were determined (magnification 10×, inset 30×). C: Total islet number per pancreas area. D: Islet size was divided into four groups, including extrasmall (XS) (<1,000 μm²), small (S) (1,001–2,200 μm²), medium (M) (2,201–4,400 μm²), and large (L) (>4,400 μm²), and islet numbers per pancreas area were calculated. E and F: Percentage of apoptotic insulin-positive cells was calculated using a TUNEL assay in pancreata from HFD-fed βNrf2KO mice. G and H: Pancreata from βNrf2KO mice were immunolabeled for insulin and DNA/RNA oxidative damage markers. DNA/RNA oxidative damage marker–positive/insulin-positive cells were calculated. I: Plasma insulin was measured from βNrf2KO mice after 29 days of HFD or RD feeding. J and K: Intraperitoneal glucose tolerance test performed in βNrf2KO mice after an overnight fast. Area under the curve (AUC) was calculated. L: Nonfasting blood glucose. Data are mean ± SEM. *P < 0.05, **P < 0.005, ***P < 0.0005, ****P < 0.0001. Veh, vehicle.