title: Brown fat biology and thermogenesis.
abstract: Brown fat (brown adipose tissue, BAT) primary function is to produce heat. There is now compelling evidence to indicate that brown fat cells in some BAT depots share their predecessor cells with myocytes. Brown adipocyte (trans)differentiation depends on various receptors / transcription factors that include peroxisome proliferator-activated receptor g (PPARgamma), PPARgamma-coactivator-1alpha (PGC1alpha), PRD1-BF1-RIZ1 homologous domain-containing 16 (PRDM16), CCAAT/enhancer-binding protein beta (C/EBP-beta) and bone morphogenetic protein 7 (BMP7). Such mediators also help BAT to acquire its thermogenic phenotype, which is essentially conferred by uncoupling protein 1 (UCP1). UCP1 uncouples adenosine-5'-triphosphate (ATP) synthesis from substrate oxidation in brown adipocytes. Its activity depends on the availability of fatty acids delivered upon BAT's beta)-adrenergic activation, which, physiologically, ensues from the sympathetic nervous system (SNS) activation of the tissue. SNS-mediated thermogenesis is largely controlled by the hypothalamus and brainstem. Recently, positron emission tomography / computed tomography (PET/CT) scanning investigations have revealed the presence in adult humans of important neck and shoulder BAT depots. That finding has contributed to reinstate a strong interest for brown adipocyte biology and thermogenesis. This review aims at the unique biology of BAT with the emphasis put on the recent discoveries regarding the brown adipocyte development and function.
authors.affiliation: Quebec Heart And Lung Institute Research Center and Laval University Interdisciplinary Group In Obesity Research, 2725 Chemin Sainte-Foy, Quebec G1V 4G5, Canada. denis.richard@criucpq.ulaval.ca
authors.forename: Denis
authors.initials: D
authors.lastname: Richard
authors.forename: Frederic
authors.initials: F
authors.lastname: Picard
mesh_terms: D052437:Adipocytes, Brown / Q000502:physiology; D052438:Adipocytes, White / Q000502:physiology; D002001:Adipose Tissue, Brown / Q000166:cytology / Q000502:physiology*; D000328:Adult; D000818:Animals; D063385:Cannabinoid Receptor Modulators / Q000502:physiology; D019070:Cell Lineage; D003080:Cold Temperature; D004268:DNA-Binding Proteins / Q000502:physiology; D003920:Diabetes Mellitus / Q000503:physiopathology; D004302:Dorsomedial Hypothalamic Nucleus / Q000502:physiology; D004734:Energy Metabolism; D005260:Female; D019788:Fluorodeoxyglucose F18; D006360:Heat-Shock Proteins / Q000502:physiology; D006801:Humans; D007028:Hypothalamic Hormones / Q000502:physiology; D007473:Ion Channels / Q000096:biosynthesis / Q000502:physiology; D008297:Male; D008543:Melanins / Q000502:physiology; D053486:Melanocortins / Q000502:physiology; D024101:Mitochondrial Proteins / Q000096:biosynthesis / Q000502:physiology; D032446:Myoblasts / Q000502:physiology; D009474:Neurons / Q000502:physiology; D047495:PPAR gamma; D000071248:Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha; D010907:Pituitary Hormones / Q000502:physiology; D011301:Preoptic Area / Q000502:physiology; D012737:Sex Factors; D013564:Sympathetic Nervous System / Q000502:physiology; D022722:Thermogenesis / Q000502:physiology*; D014157:Transcription Factors / Q000502:physiology; D000071256:Uncoupling Protein 1; D000071246:Uncoupling Protein 2
chemical_list: D063385:Cannabinoid Receptor Modulators; D004268:DNA-Binding Proteins; D006360:Heat-Shock Proteins; D007028:Hypothalamic Hormones; D007473:Ion Channels; D008543:Melanins; D053486:Melanocortins; D024101:Mitochondrial Proteins; D047495:PPAR gamma; C486497:PPARGC1A protein, human; C416371:PRDM16 protein, human; D000071248:Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha; D010907:Pituitary Hormones; D014157:Transcription Factors; C000604371:UCP1 protein, human; D000071256:Uncoupling Protein 1; D000071246:Uncoupling Protein 2; D019788:Fluorodeoxyglucose F18; C019463:melanin-concentrating hormone