Fig. 5.

GPR44 inhibition increases protein levels of PDX-1 via the Akt–GSK3β–FOXO1 signalling pathway in isolated human islets. (a–c) Phosphorylation of Akt (a; n = 8 independent donors) and GSK3β (b; n = 8 independent donors), and secretion of HGF (c; n = 6 independent donors) in human islets treated with either AZ8154 (10 μmol/l) alone or HG (20 mmol/l) + IL-1β (10 ng/ml) with or without AZ8154 (10 μmol/l) for 48 h. (d) Western blot analysis of phosphorylated FOXO1, total FOXO1 and PDX-1 in human islets treated with either AZ8154 (10 μmol/l) alone or HG (20 mmol/l) + IL-1β (10 ng/ml) with or without AZ8154 (10 μmol/l) for 48 h. (e–g) Quantification of blots shown in (d): p-FOXO1 (e; n = 7 independent donors), total FOXO1 (f; n = 5 independent donors) and PDX-1 (g; n = 7 independent donors). Band densities were normalised to GAPDH and presented as fold of changes over control (vehicle-treated) islets. For all analyses, data were analysed with one-way ANOVA with Bonferroni corrections and presented as mean ± SD. *p < 0.05 and **p < 0.01. hHGF, human HGF