Prostaglandin (PG) D-2 enhanced lipid accumulation in adipocytes. However, its molecular mechanism remains unclear. In this study, we investigated the regulatory mechanisms of PGD(2)-elevated lipid accumulation in mouse adipocytic 3T3-L1 cells. The Gi-coupled DP2 (CRTH2) receptors (DP2R), one of the two-types of PGD(2) receptors were dominantly expressed in adipocytes. A DP2R antagonist, CAY10595, but not DP1 receptor antagonist, BWA868C cleared the PGD(2)-elevated intracellular triglyceride level. While, a DP2R agonist, 15R-15-methyl PGD(2) (15R) increased the mRNA levels of the adipogenic and lipogenic genes, and decreased the glycerol release level. In addition, the forskolin-mediated increase of cAMP-dependent protein kinase A (PICA) activity and phosphorylation of hormone-sensitive lipase (HSL) was repressed by the co-treatment with 15R. Moreover, the lipolysis was enhanced in the adipocyte-differentiated DP2R gene-knockout mouse embryonic fibroblasts. These results indicate that PGD2 suppressed the lipolysis by repression of the cAMP-PKA-HSL axis through DP2R in adipocytes. (C) 2017 Elsevier Inc. All rights reserved.