title: Effects of orexin A on proliferation, survival, apoptosis and differentiation of 3T3-L1 preadipocytes into mature adipocytes.
abstract: Metabolic activities of orexin A (OXA) in mature adipocytes are mediated via PI3K/PKB and PPARγ. However, the effects of OXA on preadipocytes are largely unknown. We report here that OXA stimulates the proliferation and viability of 3T3-L1 preadipocytes and protects them from apoptosis via ERK1/2, but not through PKB. OXA reduces proapoptotic activity of caspase-3 via ERK1/2. Inhibition of ERK1/2 prevents the differentiation of preadipocytes into adipocytes. Unlike insulin, neither short-term nor prolonged exposure of 3T3-L1 preadipocytes to OXA induces preadipocyte differentiation to adipocytes, despite increased ERK1/2 phosphorylation. Unlike insulin, OXA fails to activate PKB, which explains its inability to induce the differentiation of preadipocytes.
authors.affiliation: Department of Hepatology and Gastroenterology & Interdisciplinary Centre of Metabolism: Endocrinology, Diabetes and Metabolism, Charité-University Medicine Berlin, 13353 Berlin, Germany; Department of Animal Physiology and Biochemistry, Poznań University of Life Sciences, 60-637 Poznań, Poland.
authors.forename: M
authors.initials: M
authors.lastname: Skrzypski
authors.forename: P
authors.initials: P
authors.lastname: Kaczmarek
authors.forename: T T
authors.initials: TT
authors.lastname: Le
authors.forename: T
authors.initials: T
authors.lastname: Wojciechowicz
authors.forename: E
authors.initials: E
authors.lastname: Pruszyńska-Oszmalek
authors.forename: D
authors.initials: D
authors.lastname: Szczepankiewicz
authors.forename: M
authors.initials: M
authors.lastname: Sassek
authors.forename: A
authors.initials: A
authors.lastname: Arafat
authors.forename: B
authors.initials: B
authors.lastname: Wiedenmann
authors.forename: K W
authors.initials: KW
authors.lastname: Nowak
authors.forename: M Z
authors.initials: MZ
authors.lastname: Strowski
mesh_terms: D041721:3T3-L1 Cells; D017667:Adipocytes / Q000166:cytology* / Q000187:drug effects* / Q000378:metabolism; D000818:Animals; D017209:Apoptosis / Q000187:drug effects* / Q000235:genetics; D053148:Caspase 3 / Q000378:metabolism; D002454:Cell Differentiation / Q000187:drug effects* / Q000235:genetics; D049109:Cell Proliferation / Q000187:drug effects; D047908:Intracellular Signaling Peptides and Proteins / Q000494:pharmacology*; D051379:Mice; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism; D048052:Mitogen-Activated Protein Kinase 3 / Q000378:metabolism; D009479:Neuropeptides / Q000494:pharmacology*; D000068797:Orexins; D060888:Real-Time Polymerase Chain Reaction
chemical_list: D047908:Intracellular Signaling Peptides and Proteins; D009479:Neuropeptides; D000068797:Orexins; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D053148:Caspase 3