Abstract
Effect of extracellular ATP on adipocyte differentiationMariko Omatsu-Kanbe1, Kazuko Inoue2, Norihisa Fujita2 and Hiroshi Matsuura1Dept. Physiol. Shiga Univ. Med. Sci.1, Otsu and Lab. Bioinformatic Chem., Ritsumeikan Univ.2, Kusatsu, Japan.3T3-L1 cell line is a well-established and commonly used in vitro model to assess adipocyte differentiation. Cells of this substrain undergo a preadipose to adipose-like conversion as they progress from rapidly dividing to a confluent and contact inhibited state to stop proliferation. Over the course of several days confluent 3T3-L1 preadipocytes can be converted to adipocytes in the presence of an adipogenic cocktail. It has been recognized that master regulators of differentiation, such as C/EBP and PPARγ, regulate the transcription of adipose-related genes under the cocktail. We investigated whether P2 receptor play a role in 3T3-L1 adipocyte differentiation. In cells of ~30% density, an application of extracellular ATP for 4 min prior to the addition of the cocktail induced adipocyte differentiation, while solely added cocktail did not cause differentiation. In confluent cells, extracelluar ATP did not induce differentiation or did not affect the cocktail-induced differentiation. The effect of ATP was blocked by P2 receptor antagonists suramin and PPADS. ATP-induced differentiated adipocytes contained oil Red O-stained lipid and expressed marker genes of fat cells. The results suggest that P2 receptor play an important role in the adipocyte differentiation without stopping cell proliferation. [Jpn J Physiol 54 Suppl:S81 (2004)]
