Endothelial differentiation gene-2 receptor is involved in lysophosphatidic acid-dependent control of 3T3F442A preadipocyte proliferation and spreading

EDG-2, EDG-4, EDG-7, and PSP24 genes encode distinct lysophosphatidic acid (LPA) receptors, The aim of the present study was to determine which recept or subtype is involved in the biological responses generated by LPA in prea dipocytes, Growing 3T3F442A preadipocytes express EDG-2 and EDG-4 mRNAs, wi th no expression of EDG-7 or PSP24 mRNAs. Quantitative reverse transcriptas e-polymerase chain reaction revealed that EDG-2 transcripts were 10-fold mo re abundant than that of EDG-4. To determine the involvement of the EDG-2 r eceptor in the responses of growing preadipocytes to LPA, stable transfecti on of antisense EDG-2 cDNA was performed in growing 3T3F442A preadipocytes. This procedure, led to a significant and specific reduction in EDG-2 mRNA and protein. This was associated with a significant alteration in the effec t of LPA on both cell proliferation and cell spreading, Finally, the differ entiation of growing preadipocytes into quiescent adipocytes led to a stron g reduction in the level of EDG-2 transcripts. Results demonstrate the sign ificant contribution of the EDG-2 receptor in the biological responses gene rated by LPA in 3T3F442A preadipocytes.