KPNA2 expression in PanIN-like ducts and PDGs in aged mice. (a) Representative images of alcian blue-stained pancreas of WT mouse (left) and TG mouse (right). The mucinous PanIN-like ducts in TG are morphologically different from ducts in WT of comparable size. In the mesenchyme around the PanIN-like duct, compartments of PDG, some of which are branched from the PanIN-like duct, are visible (yellow triangles). Bar, 50 μm. (b, c, d) Left panels: immunostaining of pancreas sections of for KPNA2 (shown in brown). Right panels: alcian blue-staining, (b) representative pictures of both PanIN-like and PDG ductal structures in TG, (c) PDG compartments embedded in the mesenchyme in TG, and (d) normal ductal cells in WT. A high expression of KPNA2 in the nuclei of PanIN-like cells is discernible. KPNA2 is especially highly expressed in mucinous PDG cells ([b] red triangle). KPNA2 was observed in acinar cells too ([b and d, left panels] yellow triangle). Only quite low expression of KPNA2 was observed in the normal duct (d). Bar, 20 μm.