Insulin-producing β cells from WT NOD females display enhanced susceptibility to apoptosis.

<p>A) Enhanced caspase-3 activity is detected in cell extracts of WT than in those of CD44-deficient pancreatic islet cells. Pancreatic islet cells were freshly removed from WT and CD44-deficient pre-diabetic NOD females. Cell extracts from islets were subjected to Western blot analysis, using anti-cleaved caspase-3 antibody. A representative Fig of three experiments. (B and C) Pancreata were harvested from 10-weeks-old normoglycemic WT and CD44-deficient NOD females (n = 5 in each group). β-cell apoptosis was assessed using TUNEL assay (green) and co-staining for insulin (red) and DNA (blue). B) Apoptosis was calculated as percent of TUNEL positive nuclei (+/- SEM) in insulin-positive cells out of the total number of insulin-positive cells per mouse. WT (white bar, ~17,560 total β-cells); CD44-deficient (black bar, ~14,800 total β-cells). C) Pictures are representative images of islets from WT (left panel) and CD44-deficient NOD females (right panel). Original images were taken at a magnification of x40. Inset images were digitally increased x5. White arrowheads point to apoptotic β-cells.