FATTY-ACIDS AND RETINOIDS ACT SYNERGISTICALLY ON ADIPOSE CELL-DIFFERENTIATION

Fatty acids and retinoids have been recently reported to act as positi ve effectors of adipose cell differentiation. Treatment of Ob1771 prea dipose cells with selective agonists of retinoic acid receptors (RARs) in the presence of alpha-bromopalmitate, a non-metabolized fatty acid , led to a potent synergy in regard to the differentiation process, as assayed by the activity of glycerol-3-phosphate dehydrogenase. The mo st potent synergy was observed with compound CD 367, a potent agonist of RARs as well as with compound Am 580, a specific agonist of RAR alp ha. Northern blot analysis of poly(A)(+) mRNA from cells treated with compound CD 367, alpha-bromopalmitate, or a combination of both agonis ts, did not show a dramatic effect, if any, on the expression of RAR a lpha, RAR gamma, RXR alpha and RXR beta genes. The results are discuss ed in light of the formation of heterodimers between RARs, RXRs and me mbers of the family of peroxisome proliferator-activated receptors (PP ARS). (C) 1994 Academic Press, Inc.