A New 2-Step Acceleration Protocol Using a Histone Deacetylase Inhibitor to Generate Insulin-Producing Cells From Adipose-Derived Mesenchymal Stem Cells

Objectives We aimed to develop a simple protocol for deriving insulin-producing cells (IPCs) from adipose-derived mesenchymal stem cells (ADSCs). We established a 2-step creation method and an acceleration strategy with a histone deacetylase inhibitor that promoted a pro–endocrine pancreatic lineage. Methods We seeded ADSCs in 96-well dishes and cultured in Dulbecco's modified Eagle's medium/F12 medium containing 1% fetal bovine serum, 1% B27 supplement, 1% N2 supplement, 50-ng/mL human activin A, and 10-nM exendin-4 for step 1 of differentiation (7 days). Then 10-mM nicotinamide and 50-ng/mL human hepatocyte growth factor, with or without 1 mM histone deacetylase inhibitor, were added for step 2 of differentiation (14 days). After the 2-step differentiation was complete, cell morphology, immunohistochemistry, messenger RNA expression, and function were investigated. Results Our new differentiation protocol with the histone deacetylase inhibitor significantly accelerated IPC differentiation compared with the conventional protocol without the histone deacetylase inhibitor (median, 21.6 vs 38.8 days; P < 0.05). It also improved the islet morphology score ( P < 0.05) and the glucose stimulation index (3.1). Conclusions By applying our new and easy 2-step protocol using a histone deacetylase inhibitor, ADSCs may be an effective cell source for differentiation of IPCs.