Fig. 3.

Up-regulation of Pdx1 and acceleration of islet formation by retinoic acid. Pancreatic buds were isolated, cultured for 2 days in the absence of any factors and then cultured for a further 2 days (A, B, E, F) or 5 days (C, D, G, H, K, L) without (A–D, K) or with 1 μM retinoic acid (E–H, L) and stained for (A–C, E–G) Pdx1 (red) (D, H) glucagon (green)/Pdx1 (red) (K, L) Somatostatin (green). (I) RT-PCR for amylase, fibroblast growth factor (FGF)-10, retinaldehyde dehydrogenase 2 (RALDH2), insulin 1, insulin 2, glucagon, and pdx1 under control and all-trans retinoic acid-treated conditions. (J) Glucose-stimulated insulin release from buds cells was carried out using an insulin ELISA kit. Results were adjusted for protein concentration of each well, and are shown as means+SD.