Decline of blood and pancreatic ECs during progression to diabetes. A and B: Peripheral blood cells from unmanipulated 4- to 6-week-old healthy (n = 22), 8- to 14-week-old hyperglycemic (n = 12), and 15- to 30-week-old diabetic (n = 9) mice were stained with anti-CD45, anti-PECAM1, and 7-AAD, and PECAM1 expression was analyzed on 7-AAD−CD45− gated cells. A: Representative FACS plots. B: Results of individually tested mice in each group. C and D: Nonserial pancreatic sections from the same groups of mice were stained for insulin (green) and PECAM1 (red) and analyzed
by immunofluorescence microscopy. C: A representative staining within the boundary of an islet area. Scale bars, 50 μm. D: The number of PECAM1+ cells per islet. This was determined by nuclear counterstaining with DAPI. At least 40 islets from three to six nonserial
sections per mouse were analyzed. Each bar represents mean ± SEM of five mice per group. *P < 0.05; **P < 0.01.