title: A proteomic analysis reveals that Snail regulates the expression of the nuclear orphan receptor Nuclear Receptor Subfamily 2 Group F Member 6 (Nr2f6) and interleukin 17 (IL-17) to inhibit adipocyte differentiation.
abstract: Adipogenesis requires a differentiation program driven by multiple transcription factors, where PPARγ and C/EBPα play a central role. Recent findings indicate that Snail inhibits adipocyte differentiation in 3T3-L1 and murine mesenchymal stem cells (mMSC). An in-depth quantitative SILAC analysis of the nuclear fraction of Snail-induced alterations of 3T3-L1 cells was carried out. In total, 2251 overlapping proteins were simultaneously quantified in forward and reverse experiments. We observed 574 proteins deregulated by Snail1 using a fold-change ≥1.5, with 111 up- and 463 down-regulated proteins, respectively. Among other proteins, multiple transcription factors such as Trip4, OsmR, Nr2f6, Cbx6, and Prrx1 were down-regulated. Results were validated in 3T3-L1 cells and mMSC cells by Western blot and quantitative PCR. Knock-down experiments in 3T3-L1 cells demonstrated that only Nr2f6 (and Trip4 at minor extent) was required for adipocyte differentiation. Ectopic expression of Nr2f6 reversed the effects of Snail1 and promoted adipogenesis. Because Nr2f6 inhibits the expression of IL-17, we tested the effect of Snail on IL-17 expression. IL-17 and TNFα were among the most up-regulated pro-inflammatory cytokines in Snail-transfected 3T3-L1 and mMSC cells. Furthermore, the blocking of IL-17 activity in Snail-transfected cells promoted adipocyte differentiation, reverting Snail inhibition. In summary, Snail inhibits adipogenesis through a down-regulation of Nr2f6, which in turn facilitates the expression of IL-17, an anti-adipogenic cytokine. These results would support a novel and important role for Snail and Nr2f6 in obesity control.
authors.affiliation: From the ‡Department of Cellular and Molecular Medicine, Centro de Investigaciones Biológicas (CIB-CSIC), Madrid, Spain;
authors.forename: Alberto
authors.initials: A
authors.lastname: Peláez-García
authors.affiliation: §Departamento de Biochemistry and Molecular Biology Department I, Universidad Complutense de Madrid, Spain;
authors.forename: Rodrigo
authors.initials: R
authors.lastname: Barderas
authors.affiliation: ¶IMIM-Hospital del Mar. Barcelona, Spain;
authors.forename: Raquel
authors.initials: R
authors.lastname: Batlle
authors.affiliation: ¶IMIM-Hospital del Mar. Barcelona, Spain;
authors.forename: Rosa
authors.initials: R
authors.lastname: Viñas-Castells
authors.affiliation: From the ‡Department of Cellular and Molecular Medicine, Centro de Investigaciones Biológicas (CIB-CSIC), Madrid, Spain;
authors.forename: Rubén A
authors.initials: RA
authors.lastname: Bartolomé
authors.affiliation: From the ‡Department of Cellular and Molecular Medicine, Centro de Investigaciones Biológicas (CIB-CSIC), Madrid, Spain;
authors.forename: Sofía
authors.initials: S
authors.lastname: Torres
authors.affiliation: From the ‡Department of Cellular and Molecular Medicine, Centro de Investigaciones Biológicas (CIB-CSIC), Madrid, Spain;
authors.forename: Marta
authors.initials: M
authors.lastname: Mendes
authors.affiliation: From the ‡Department of Cellular and Molecular Medicine, Centro de Investigaciones Biológicas (CIB-CSIC), Madrid, Spain;
authors.forename: María
authors.initials: M
authors.lastname: Lopez-Lucendo
authors.affiliation: ¶IMIM-Hospital del Mar. Barcelona, Spain;
authors.forename: Rocco
authors.initials: R
authors.lastname: Mazzolini
authors.affiliation: ‖Hospital Puerta de Hierro, Majadahonda, Madrid, Spain.
authors.forename: Félix
authors.initials: F
authors.lastname: Bonilla
authors.affiliation: ¶IMIM-Hospital del Mar. Barcelona, Spain;
authors.forename: Antonio
authors.initials: A
authors.lastname: García de Herreros
authors.affiliation: From the ‡Department of Cellular and Molecular Medicine, Centro de Investigaciones Biológicas (CIB-CSIC), Madrid, Spain; icasal@cib.csic.es.
authors.forename: J Ignacio
authors.initials: JI
authors.lastname: Casal
mesh_terms: D041721:3T3-L1 Cells; D017667:Adipocytes / Q000166:cytology* / Q000378:metabolism*; D050156:Adipogenesis; D000818:Animals; D051836:COUP Transcription Factors / Q000378:metabolism*; D002454:Cell Differentiation; D002457:Cell Extracts; D002467:Cell Nucleus / Q000378:metabolism; D015536:Down-Regulation; D020381:Interleukin-17 / Q000378:metabolism*; D059630:Mesenchymal Stem Cells / Q000378:metabolism; D051379:Mice; D008954:Models, Biological; D040901:Proteomics / Q000379:methods*; D012097:Repressor Proteins; D015203:Reproducibility of Results; D015398:Signal Transduction; D000071250:Snail Family Transcription Factors; D014157:Transcription Factors / Q000378:metabolism*; D014162:Transfection
chemical_list: D051836:COUP Transcription Factors; D002457:Cell Extracts; D020381:Interleukin-17; C484221:Nr2f6 protein, mouse; D012097:Repressor Proteins; C000604429:Snai1 protein, mouse; D000071250:Snail Family Transcription Factors; D014157:Transcription Factors