title: Browning of white adipose tissue: lessons from experimental models.
abstract: Beige or brite (brown-in-white) adipocytes are present in white adipose tissue (WAT) and have a white fat-like phenotype that when stimulated acquires a brown fat-like phenotype, leading to increased thermogenesis. This phenomenon is known as browning and is more likely to occur in subcutaneous fat depots. Browning involves the expression of many transcription factors, such as PR domain containing 16 (PRDM16) and peroxisome proliferator-activated receptor (PPAR)-γ, and of uncoupling protein (UCP)-1, which is the hallmark of thermogenesis. Recent papers pointed that browning can occur in the WAT of humans, with beneficial metabolic effects. This fact indicates that these cells can be targeted to treat a range of diseases, with both pharmacological and nutritional activators. Pharmacological approaches to induce browning include the use of PPAR-α agonist, adrenergic receptor stimulation, thyroid hormone administration, irisin and FGF21 induction. Most of them act through the induction of PPAR-γ coactivator (PGC) 1-α and the consequent mitochondrial biogenesis and UCP1 induction. About the nutritional inducers, several compounds have been described with multiple mechanisms of action. Some of these activators include specific amino acids restriction, capsaicin, bile acids, Resveratrol, and retinoic acid. Besides that, some classes of lipids, as well as many plant extracts, have also been implicated in the browning of WAT. In conclusion, the discovery of browning in human WAT opens the possibility to target the adipose tissue to fight a range of diseases. Studies have arisen showing promising results and bringing new opportunities in thermogenesis and obesity control.
authors.affiliation: Laboratory of Morphometry, Metabolism and Cardiovascular Diseases, Biomedical Center, Institute of Biology, State University of Rio de Janeiro, Rio de Janeiro, Brazil.
authors.forename: Thereza Cristina Lonzetti
authors.initials: TCL
authors.lastname: Bargut
authors.affiliation: Laboratory of Morphometry, Metabolism and Cardiovascular Diseases, Biomedical Center, Institute of Biology, State University of Rio de Janeiro, Rio de Janeiro, Brazil.
authors.forename: Vanessa
authors.initials: V
authors.lastname: Souza-Mello
authors.affiliation: Laboratory of Morphometry, Metabolism and Cardiovascular Diseases, Biomedical Center, Institute of Biology, State University of Rio de Janeiro, Rio de Janeiro, Brazil.
authors.forename: Marcia Barbosa
authors.initials: MB
authors.lastname: Aguila
authors.affiliation: Laboratorio de Morfometria, Metabolismo e Doença Cardiovascular, Instituto de Biologia, Universidade do Estado do Rio de Janeiro, 20551-030 Rio de Janeiro, Brazil, Phone (+55.21) 2868-8316, Fax: 2868-8033, E-mail: mandarim.ca@gmail.com.
authors.forename: Carlos Alberto
authors.initials: CA
authors.lastname: Mandarim-de-Lacerda
mesh_terms: D000220:Adaptation, Biological; D017667:Adipocytes / Q000166:cytology; D000069797:Adipocytes, Beige / Q000502:physiology; D002001:Adipose Tissue, Brown / Q000187:drug effects / Q000502:physiology*; D052436:Adipose Tissue, White / Q000187:drug effects / Q000502:physiology*; D000818:Animals; D003080:Cold Temperature; D004734:Energy Metabolism; D005786:Gene Expression Regulation; D006801:Humans; D023421:Models, Animal; D009747:Nutritional Physiological Phenomena; D015398:Signal Transduction; D022722:Thermogenesis
keywords: UCP-1; brite adipocytes; browning; browning induction; white adipose tissue