Figure 2

Reg3α overexpression in islet grafts preserved functional islet mass by influencing β-cell apoptosis and replication. (A) Functioning islet grafts under the renal capsule of diabetic BALB/c mice were retrieved on d 30 after transplantation. H&E staining and immunohistochemical staining of insulin using 3,3’-diaminobenzidine tetrahydrochloride (DAB) were analyzed. Scale bar = 100 µm and referred to all panels. (B) Apoptotic and (C) replicating β cells were stained with TUNEL and Ki-67 conjugated with red fluorescence in islet grafts, respectively. Insulin showed green and nuclei were stained with blue DAPI dye. Scale bar = 50 µm and referred to all panels. (D) Insulin staining was analyzed semiquantitatively by the average optical density of insulin⁺ cells adjusted for islet areas. (E–F) The apoptotic (E) and proliferative (F) ratio of pancreatic β cells in grafts was calculated as averaging the number of TUNEL⁺/insulin⁺ or Ki-67⁺/insulin⁺ cells divided by the number of insulin⁺ cells in islet grafts, respectively. At least three sections from animals were analyzed in each treatment group. Values represent the means ± SEM, *P < 0.05 denoted significance between Reg3α (n = 11) and EGFP (n = 9) or Mock (n = 7) group.