Conjugated linoleic acid increases the differentiation of porcine adipocytes in vitro

Individual long-chain fatty acids can modulate adipocyte differentiation. Conjugated linoleic acids (CLAs) either stimulate or inhibit 3T3-L1 clonal cell differentiation. We studied the effects of cis-9, trans-11 CLA (9,11-CLA), trans-10, cis-12 CLA (10, 12-CLA), and linoleic acid (LA) on differentiation of porcine stromal-vascular cells in vitro and on mRNA concentrations for adipocyte transcription factors and adipocyte-characteristic proteins. Fatty acids were added to the differentiation medium at 0, 50, 100, or 300 muM, for 24 hours. The LA tended to, and 9,11-CLA increased differentiation. Peroxisome proliferator-activated receptor gamma (PPAR gamma) mRNA concentration was not changed by LA, 9,11-CLA, or 10,12-CLA. Lipoprotein lipase mRNA concentration was not changed by LA, but was increased by both CLA isomers. Adipocyte fatty acid binding protein (aP2) mRNA concentration was increased by LA and both isomers of CLA. In summary, CLA and LA increased differentiation of porcine stromal-vascular cells after 24 hours, but differentiation was not accompanied by increased PPAR gamma mRNA suggesting, at least in these experiments, that the primary action of the fatty acids was as ligands for PPAR gamma, rather than as inducers for PPAR gamma transcripts. The aP2 mRNA concentration was increased to a large extent by the various fatty acids. (C) 2000 Elsevier Science Inc.