FIGURE 4:

Beta cell proliferation is defective in RIP2-Opa1KO mice. (A) Immunofluorescence of pancreas sections using antibodies to Ki67 for cell proliferation (green) and insulin for beta cells (red) in newborns (1 wk old) and adults (8–12 wk old). (B) The percentage of beta cells showing Ki67 signals was determined (n ≥ 3). (C) Insulin-positive islet area in newborn and adult mice was measured (n = 3). (D) Ratio of beta cell area to alpha cell area was calculated (n = 3). (E) Sections of pancreas were subjected to TUNEL analysis using the In Situ Cell Death Detection Kit (Roche Applied Science, Indianapolis, IN). TUNEL signals (green) and immunostaining using anti-insulin antibodies are shown (red). As a positive control, sections were incubated with DNase I according to the manufacturer's instructions. (F) Quantification of islets that contain TUNEL-positive beta cells. Average ± SEM is shown (n = 3). Numbers in parentheses indicate the total number of islets examined. (G) Immunoblotting of islets using antibodies to PARP, caspase-3, and actin.