Figure 3

The Characteristics of α-cell-derived insulin-producing cells. (A) Representative images of two types of insulin-producing cells derived from α cells. Immunostaining for FLAG-tagged Pdx1 (blue), glucagon (green), and insulin (red) was performed on pancreas sections of αPdx1; Stat3^KO mice. A FLAG-tag/insulin double positive cell that is negative for glucagon staining (arrow), which denotes Gcg-silenced α-to-β conversion, and a FLAG-tag positive cell expressing both insulin and glucagon (arrowhead), which denotes α-to-bihormonal transition are shown. Scale bars, 10 μm. (B) The percentage of α-cell-derived insulin-expressing cells that do not express glucagon among total α-cell-derived β cells. ***p < 0.005 (n = 5 in each group). (C) Immunostaining for FLAG-tagged Pdx1 (green), Nkx6.1 (red) and insulin (white) in pancreas sections of αPdx1; Stat3^KO mice 2 weeks after tamoxifen administration. The arrowhead indicates a FLAG-tag-positive cell that expresses both Nkx6.1 and insulin. The arrow indicates FLAG-tag/insulin double positive cells that lack Nkx6.1. Scale bars, 50 μm. Magnified images of the dotted square regions are shown below each image. (D) Percentage of Nkx6.1-positive cells among FLAG-tag/insulin double-positive cells (α-cell-derived β cells). Pancreata of Stat3-knockout mice have a significantly higher number of α-cell-derived Nkx6.1-expressing β cells than pancreata of control mice. *p < 0.05 (n = 3 in each group). (E) Immunostaining for FLAG-tagged Pdx1 (white), UCN3 (green) and insulin (red) in pancreas sections of αPdx1; Stat3^KO mice 2 weeks after tamoxifen administration. The arrowhead indicates a FLAG-tag positive cell that expresses both urocortin3 and insulin. The arrow indicates a FLAG-tag/insulin double-positive cell that lacks urocortin3. Magnified images of the dotted square regions are shown below each image. (F) The percentage of urocortin3-positive cells among FLAG-tag/insulin double-positive cells (α-derived β cells, n = 3 in each group).