Adipocytes take up long chain fatty acids through diffusion and protein mediated transport, whereas fatty acid efflux is considered to occur by diffusion. To identify potential membrane proteins that are involved in regulating fatty acid flux in adipocytes, the expression levels of 55 membrane transporters without known function were screened in subcutaneous adipose samples from obese patients before and after bariatric surgery using branched DNA methodology. Among the 33 solute carrier (SLC) transporter family members screened, the expression of 14 members showed significant changes before and after bariatric surgery. One of them, Slc43a3, increased about 2.5-fold after bariatric surgery. Further investigation demonstrated that Slc43a3 is highly expressed in murine adipose tissue and induced during adipocyte differentiation in primary preadipocytes and in OP9 cells. Knockdown of Slc43a3 with siRNA in differentiated OP9 adipocytes reduced both basal and forskolin-stimulated fatty acid efflux, while also increasing fatty acid uptake and lipid droplet accumulation. In contrast, overexpression of Slc43a3 decreased fatty acid uptake in differentiated OP9 cells and resulted in decreased lipid droplet accumulation. Therefore, Slc43a3 seems to regulate fatty acid flux in adipocytes, functioning as a positive regulator of fatty acid efflux and as a negative regulator of fatty acid uptake.
View details for DOI 10.1194/jlr.RA119000294
View details for PubMedID 32217606