Acute Inhibition of PI3K-PDK1-Akt Pathway Potentiates Insulin Secretion through Upregulation of Newcomer Granule Fusions in Pancreatic β-Cells
Figure 1
PIK-75 inhibited class IA PI3K and enhanced the glucose-induced insulin secretion.
(A) Freshly isolated islets treated with PIK-75 at the indicated concentrations for 30 min were subjected to immunoblotting using anti-Phospho-Akt and anti-Pan-Akt antibodies. Phospho-Akt signal intensity normalized to control was quantified (n = 3 for each group). (B) Freshly isolated islets pre-treated with PIK-75 at the indicated concentrations for 30 min were stimulated with 2.2 mM or 16 mM glucose for 30 min. The amount of secreted insulin were expressed as a percentage of the total cellular content (n = 6 for each group). (C) Pancreatic islets freshly isolated from p85α/p85β DKO mice were pre-treated with or without 0.5 µM PIK-75 for 30 min and stimulated with 2.2 mM or 16 mM glucose for 30 min. The amount of secreted insulin were expressed as a percentage of the total cellular content (n = 6 for each group). Data are the means ± S.E.M. (*, p<0.03; **, p<0.01).