title: Isoproterenol Increases Uncoupling, Glycolysis, and Markers of Beiging in Mature 3T3-L1 Adipocytes.
abstract: Beta-adrenergic activation stimulates uncoupling protein 1 (UCP1), enhancing metabolic rate. In vitro, most work has studied brown adipocytes, however, few have investigated more established adipocyte lines such as the murine 3T3-L1 line. To assess the effect of beta-adrenergic activation, mature 3T3-L1s were treated for 6 or 48 hours with or without isoproterenol (10 and 100 μM) following standard differentiation supplemented with thyroid hormone (T3; 1 nM). The highest dose of isoproterenol increased lipid content following 48 hours of treatment. This concentration enhanced UCP1 mRNA and protein expression. The increase in UCP1 following 48 hours of isoproterenol increased oxygen consumption rate. Further, coupling efficiency of the electron transport chain was disturbed and an enhancement of glycolytic rate was measured alongside this, indicating an attempt to meet the energy demands of the cell. Lastly, markers of beige adipocytes (protein content of CD137 and gene transcript of CITED1) were also found to be upregulated at 48 hours of isoproterenol treatment. This data indicates that mature 3T3-L1 adipocytes are responsive to isoproterenol and induce UCP1 expression and activity. Further, this finding provides a model for further pharmaceutical and nutraceutical investigation of UCP1 in 3T3-L1s.
authors.affiliation: Department of Animal and Dairy Sciences, University of Georgia, Athens, Georgia, United States of America; Department of Foods and Nutrition, University of Georgia, Athens, Georgia, United States of America.
authors.forename: Colette N
authors.initials: CN
authors.lastname: Miller
authors.affiliation: Complex Carbohydrate Research Center, University of Georgia, Athens, Georgia, United States of America.
authors.forename: Jeong-Yeh
authors.initials: JY
authors.lastname: Yang
authors.affiliation: Neuroscience Division, Biomedical and Health Sciences Institute, University of Georgia, Athens, Georgia, United States of America.
authors.forename: Emily
authors.initials: E
authors.lastname: England
authors.affiliation: Complex Carbohydrate Research Center, University of Georgia, Athens, Georgia, United States of America.
authors.forename: Amelia
authors.initials: A
authors.lastname: Yin
authors.affiliation: Department of Animal and Dairy Sciences, University of Georgia, Athens, Georgia, United States of America; Department of Foods and Nutrition, University of Georgia, Athens, Georgia, United States of America.
authors.forename: Clifton A
authors.initials: CA
authors.lastname: Baile
authors.affiliation: Pharmaceutical Sciences, Philadelphia College of Osteopathic Medicine-GA Campus, Suwanee, Georgia, United States of America.
authors.forename: Srujana
authors.initials: S
authors.lastname: Rayalam
mesh_terms: D041721:3T3-L1 Cells; D017667:Adipocytes / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism*; D000318:Adrenergic beta-Agonists / Q000494:pharmacology*; D000818:Animals; D006019:Glycolysis / Q000187:drug effects*; D007473:Ion Channels / Q000235:genetics*; D007545:Isoproterenol / Q000494:pharmacology*; D051379:Mice; D024101:Mitochondrial Proteins / Q000235:genetics*; D012333:RNA, Messenger / Q000235:genetics; D000071256:Uncoupling Protein 1; D015854:Up-Regulation / Q000187:drug effects
chemical_list: D000318:Adrenergic beta-Agonists; D007473:Ion Channels; D024101:Mitochondrial Proteins; D012333:RNA, Messenger; C000604372:Ucp1 protein, mouse; D000071256:Uncoupling Protein 1; D007545:Isoproterenol