title: Adipogenesis, lipogenesis and lipolysis is stimulated by mild but not severe hypoxia in 3T3-L1 cells.
abstract: In-vitro investigation of the effects of hypoxia is limited by physical laws of gas diffusion and cellular O2 consumption, making prolonged exposures to stable O2 concentrations impossible. Using a gas-permeable cultureware, chronic effects of mild and severe hypoxia on triglyceride accumulation, lipid droplet size distribution, spontaneous lipolysis and gene expression of adipocyte-specific markers were assessed. 3T3-L1 cells were differentiated under 20%, 4% or 1% O2 using a gas-permeable cultureware. Triglyceride accumulation, expression of genes characteristic for advanced adipocyte differentiation and involvement of key lipogenesis enzymes were assessed after exposures. Lipogenesis increased by 375% under mild hypoxia, but dropped by 43% in severe hypoxia. Mild, but not severe, hypoxia increased formation of large lipid droplets 6.4 fold and strongly induced gene expression of adipocyte-specific markers. Spontaneous lipolysis increased by 488% in mild, but only by 135% in severe hypoxia. Inhibition of ATP-dependent citrate lyase suppressed hypoxia-induced lipogenesis by 81% and 85%. Activation of HIF inhibited lipogenesis by 59%. Mild, but not severe, hypoxia stimulates lipolysis and promotes adipocyte differentiation, probably through excess of acetyl-CoA originating from tricarboxylic acid cycle independently of HIF activation.
authors: Center for Research on Diabetes, Metabolism and Nutrition, Third Faculty of Medicine, Charles University in Prague, Ruska 87, Prague, Czech Republic.
authors: Martin
authors: M
authors: Weiszenstein
authors: Center for Research on Diabetes, Metabolism and Nutrition, Third Faculty of Medicine, Charles University in Prague, Ruska 87, Prague, Czech Republic.
authors: Martina
authors: M
authors: Musutova
authors: Center for Research on Diabetes, Metabolism and Nutrition, Third Faculty of Medicine, Charles University in Prague, Ruska 87, Prague, Czech Republic.
authors: Andrea
authors: A
authors: Plihalova
authors: Center for Research on Diabetes, Metabolism and Nutrition, Third Faculty of Medicine, Charles University in Prague, Ruska 87, Prague, Czech Republic; Center of Toxicology and Health Safety, The National Institute of Public Health, Srobarova 48, Prague, Czech Republic.
authors: Katerina
authors: K
authors: Westlake
authors: Laboratory for Metabolism and Bioenergetics, Third Faculty of Medicine, Charles University in Prague, Ruska 87, Prague, Czech Republic.
authors: Moustafa
authors: M
authors: Elkalaf
authors: Department of Sport Medicine, Third Faculty of Medicine, Charles University in Prague, Ruska 87, Prague, Czech Republic.
authors: Michal
authors: M
authors: Koc
authors: Institute of Biophysics and Informatics, First Faculty of Medicine, Charles University in Prague, Salmovska 1, Prague, Czech Republic.
authors: Antonin
authors: A
authors: Prochazka
authors: Department of Sport Medicine, Third Faculty of Medicine, Charles University in Prague, Ruska 87, Prague, Czech Republic.
authors: Jan
authors: J
authors: Pala
authors: Center for Research on Diabetes, Metabolism and Nutrition, Third Faculty of Medicine, Charles University in Prague, Ruska 87, Prague, Czech Republic.
authors: Sumeet
authors: S
authors: Gulati
authors: Laboratory for Metabolism and Bioenergetics, Third Faculty of Medicine, Charles University in Prague, Ruska 87, Prague, Czech Republic.
authors: Jan
authors: J
authors: Trnka
authors: Center for Research on Diabetes, Metabolism and Nutrition, Third Faculty of Medicine, Charles University in Prague, Ruska 87, Prague, Czech Republic; Center of Toxicology and Health Safety, The National Institute of Public Health, Srobarova 48, Prague, Czech Republic. Electronic address: jan.polak@lf3.cuni.cz.
authors: Jan
authors: J
authors: Polak
mesh_terms: D041721:3T3-L1 Cells; D001275:ATP Citrate (pro-S)-Lyase / Q000235:genetics / Q000378:metabolism; D000105:Acetyl Coenzyme A / Q000378:metabolism; D017667:Adipocytes / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D050156:Adipogenesis / Q000187:drug effects* / Q000235:genetics; D000818:Animals; D002454:Cell Differentiation / Q000187:drug effects; D015687:Cell Hypoxia; D002952:Citric Acid Cycle / Q000187:drug effects / Q000235:genetics; D051048:Diacylglycerol O-Acyltransferase / Q000235:genetics / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D050556:Fatty Acid-Binding Proteins / Q000235:genetics / Q000378:metabolism; D005786:Gene Expression Regulation / Q000187:drug effects*; D051795:Hypoxia-Inducible Factor 1, alpha Subunit / Q000235:genetics / Q000378:metabolism; D066292:Lipid Droplets / Q000737:chemistry / Q000187:drug effects; D050155:Lipogenesis / Q000187:drug effects* / Q000235:genetics; D008066:Lipolysis / Q000187:drug effects* / Q000235:genetics; D051379:Mice; D010100:Oxygen / Q000494:pharmacology*; D000070778:Perilipin-1 / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction; D002787:Sterol Esterase / Q000235:genetics / Q000378:metabolism; D014280:Triglycerides / Q000378:metabolism
chemical_list: C493411:Fabp4 protein, mouse; D050556:Fatty Acid-Binding Proteins; C497442:HIF1A protein, human; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D000070778:Perilipin-1; C000602979:Plin1 protein, mouse; D014280:Triglycerides; D000105:Acetyl Coenzyme A; C516957:DGAT2 protein, mouse; D051048:Diacylglycerol O-Acyltransferase; D001275:ATP Citrate (pro-S)-Lyase; D002787:Sterol Esterase; D010100:Oxygen
keywords: Adipocytes; Differentiation; Gene expression; Hypoxia; Lipogenesis; Lipolysis