Exendin-4 treatment increases transplanted human beta cell mass, and reduces apoptosis.

<p>After 15 days of treatment -/+ exendin-4 treatment with a low (20μg/kg/day) or high (200μg/kg/day) dose, the cell nuclei in the grafts were counted (a). The ratio of TUNEL positive cells to insulin was calculated in the transplanted grafts after 15 days of exendin-4 treatment. Immunofluorescence staining was performed as indicated in methods, and representative images (c) show DAPI (blue), insulin (red) and TUNEL (green) staining in transplanted human islets treated with a low (20μg/kg/day) or high (200μg/kg/day) dose of exendin-4, or saline (control). The right-hand panel (I-III) shows TUNEL staining indicated by the arrows. The results for each column are expressed as mean ±SD. **** p<0, 0001 by one-way ANOVA followed by Bonferroni correction vs. saline treated control.