Expression of KPNA2 in pancreatic islets and intra-islet ducts in aged TGs. (a) Alcian blue-stained pancreas sections of WT (left) and TG (right). For TG, two islets are shown. The left-hand side islet contains mucin-producing intra-islet ducts. Bar, 50 μm. (b) Immunostaining of pancreas sections for cytokeratin 17/19 (brown), followed by staining with alcian blue of WT (left panel) and TG (middle and right panels). Bar, 20 μm. Two typical cases of islets with unusual multiple intra-islet ducts are shown. (c) Immunostaining of islets for KPNA2 (brown) with alcian blue staining of WT (left panel) and TG (right panel). Bar, 20 μm. KPNA2 is located abundantly in the nuclei of endocrine cells of the islet in WT (left panel). KPNA2 resides also in the nuclei of acinar cells (left panel, yellow triangles). In the intraductal cells producing mucin of TG, a high expression of KPNA2 was observed (right panel, red triangle). (d) Immunostaining of islets for KPNA2 (shown in brown) of WT (left panel) and TG (right panel). Bar, 20 μm. In TG, the expression of KPNA2 in each cell in the islet was lower than that of WT.