Insulitis in T1D patients with diabetes is associated with increased islet vascularity. The islet boundary (white line) was
defined by insulin and DAPI staining (A, B, E, and F). Immunofluorescent staining of control (C) and T1D patients (D) reveals that all islet vessels (red) also expressed VEGFR-2 (green). Coexpression of both markers is indicated in yellow.
Representative micrographs of control (G) and T1D patients (H) reveal that CD45+ leukocytes (red) do not express VEGFR-2 (green). We also found that insulin+ β-cells (purple) did not express VEGFR-2 (green) in control (I) or T1D patient (J) pancreata. The field of view depicted in I and J corresponds to the same images shown in C and D, respectively. The white arrows in I and J point to VEGFR-2+ cells, which according to C and D are CD31+ vessels. Quantification of the VEGFR-2+ (K) and CD45+ (L) islet area in control and T1D patient pancreata revealed that both were increased in T1D patients.