title: Regulation of adipogenesis by natural and synthetic REV-ERB ligands.
abstract: The nuclear hormone receptor, REV-ERB, plays an essential role in adipogenesis. Rev-erbalpha expression is induced in 3T3-L1 cells during adipogenesis, and overexpression of this receptor leads to expression of adipogenic genes. We recently demonstrated that the porphyrin heme functions as a ligand for REV-ERB, and binding of heme is required for the receptor's activity. We therefore hypothesized that REV-ERB ligands may play a role in regulation of adipogenesis. We detected an increase intracellular heme levels during 3T3-L1 adipogenesis that correlated with induction of aminolevulinic acid synthase 1 (Alas1) expression, the rate-limiting enzyme in heme biosynthesis. If the increase in Alas1 expression was blocked, adipogenesis was severely attenuated, indicating that induction of expression of Alas1 and the increase in heme synthesis is critical for differentiation. Inhibition of heme synthesis during adipogenesis leads to decreased recruitment of nuclear receptor corepressor to the promoter of a REV-ERB target gene, suggesting alteration of REV-ERB activity. Treatment of 3T3-L1 cells with a synthetic REV-ERB ligand, SR6452, resulted in induction of adipocyte differentiation to a similar extent as treatment with the peroxisomal proliferator-activated receptor-gamma agonist, rosiglitazone. Combination of SR6452 and rosiglitazone had an additive effect on stimulation of adipocyte differentiation. These results suggest that heme, functioning as a REV-ERB ligand, is an important signaling molecule for induction of adipogenesis. Moreover, synthetic small molecule ligands for REV-ERB are effective modulators of adipogenesis and may be useful for treatment of metabolic diseases.
authors.affiliation: The Scripps Research Institute, 130 Scripps Way 2A1, Jupiter, FL 33458, USA.
authors.forename: Naresh
authors.initials: N
authors.lastname: Kumar
authors.forename: Laura A
authors.initials: LA
authors.lastname: Solt
authors.forename: Yongjun
authors.initials: Y
authors.lastname: Wang
authors.forename: Pamela M
authors.initials: PM
authors.lastname: Rogers
authors.forename: Gargi
authors.initials: G
authors.lastname: Bhattacharyya
authors.forename: Theodore M
authors.initials: TM
authors.lastname: Kamenecka
authors.forename: Keith R
authors.initials: KR
authors.lastname: Stayrook
authors.forename: Christine
authors.initials: C
authors.lastname: Crumbley
authors.forename: Z Elizabeth
authors.initials: ZE
authors.lastname: Floyd
authors.forename: Jeffrey M
authors.initials: JM
authors.lastname: Gimble
authors.forename: Patrick R
authors.initials: PR
authors.lastname: Griffin
authors.forename: Thomas P
authors.initials: TP
authors.lastname: Burris
mesh_terms: D041721:3T3-L1 Cells; D000624:5-Aminolevulinate Synthetase / Q000235:genetics / Q000378:metabolism; D050156:Adipogenesis / Q000187:drug effects* / Q000235:genetics; D000818:Animals; D015153:Blotting, Western; D002454:Cell Differentiation / Q000187:drug effects; D047369:Chromatin Immunoprecipitation; D006418:Heme / Q000494:pharmacology; D008024:Ligands; D051379:Mice; D056953:Nuclear Receptor Subfamily 1, Group D, Member 1 / Q000819:agonists / Q000378:metabolism*; D034741:RNA, Small Interfering; D000077154:Rosiglitazone; D045162:Thiazolidinediones / Q000494:pharmacology
chemical_list: D008024:Ligands; D056953:Nuclear Receptor Subfamily 1, Group D, Member 1; D034741:RNA, Small Interfering; D045162:Thiazolidinediones; D000077154:Rosiglitazone; D006418:Heme; D000624:5-Aminolevulinate Synthetase