Generation and characterization of mBAP‐9, a new in vitro brown adipogenesis model

Abstract

We have established mBAP‐9, a new brown preadipocyte cell line, from interscapular BAT of C57BL/6 mice. mBAP‐9 preadipocytes undergo spontaneous adipogenesis which is enhanced by treatment with a combination of dexamethasone, 3‐methyl‐1‐isobutylxanthine, indomethacin, insulin and triiodotyronine. mBAP‐9 adipogenesis is accompanied by formation of multilocular lipid droplets, induction of Ucp1 and PPARα transcripts, and expression of PGC‐1α . Using a candidate gene approach based on in silico analysis of the GNF Symatlas database, we identified 10 new adipocyte differentiation‐dependent genes that exhibit marked upregulation during mBAP‐9 adipogenesis. Three of these genes, carboxymethylene butenolidase‐like (Cmbl), a new adipose tissue α/β hydrolase (Atabh), and Tmem182 were further characterized. Cmbl, Atabh and Tmem182 are induced 24‐fold, 13‐fold, and 45‐fold, respectively, during in vitro adipogenesis of mBAP‐9 preadipocytes and evidence differential regulation by β‐adrenergic agonists in mBAP‐9 adipocytes. Transcripts for Cmbl, Atabh and Tmem182 are also upregulated during in vitro white adipogenesis of 3T3‐L1 cells, are expressed in BAT and in white adipose tissue (WAT) in vivo, and evidence dysregulation in obese adipose tissue(s). We conclude that the mBAP‐9 preadipocyte cell line we have developed is a novel and useful tool for detailed molecular studies of adipogenesis.