Phosphoinositide 3-kinase is required for human adipocyte differentiation in culture.

Abstract

Phosphoinositide 3-kinase (PI3K) is required for murine adipocyte differentiation. However, a recent report concluded that PI3K was not involved in the differentiation of human preadipocytes into adipocytes. We have re-examined the role of PI3K in human preadipocyte differentiation, enrolling more patients and using more adipogenic indices. Human preadipocytes, isolated from nine patients, were induced to differentiate in the presence or absence of 100 nM wortmannin. After 12-15 days, triacylglycerol accumulation and the expression of adipogenic markers (fatty acid synthase and adiponectin) were measured. A significant inhibition in triacylglycerol accumulation and in the induction of fatty acid synthase protein expression was observed, but there was no effect on adiponectin protein expression. Inhibition of PI3K reduces the differentiation of human preadipocytes into adipocytes, suggesting a role for this enzyme in the human adipogenic process.