151
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Aldiss P, Dellschaft N, Sacks H, Budge H, Symonds ME. Beyond obesity – thermogenic adipocytes and cardiometabolic health. Horm Mol Biol Clin Investig 2017; 31:/j/hmbci.ahead-of-print/hmbci-2017-0007/hmbci-2017-0007.xml. [DOI: 10.1515/hmbci-2017-0007] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2017] [Accepted: 03/22/2017] [Indexed: 12/22/2022]
Abstract
AbstractThe global prevalence of obesity and related cardiometabolic disease continues to increase through the 21st century. Whilst multi-factorial, obesity is ultimately caused by chronic caloric excess. However, despite numerous interventions focussing on reducing caloric intake these either fail or only elicit short-term changes in body mass. There is now a focus on increasing energy expenditure instead which has stemmed from the recent ‘re-discovery’ of cold-activated brown adipose tissue (BAT) in adult humans and inducible ‘beige’ adipocytes. Through the unique mitochondrial uncoupling protein 1 (UCP1), these thermogenic adipocytes are capable of combusting large amounts of chemical energy as heat and in animal models can prevent obesity and cardiometabolic disease. At present, human data does not point to a role for thermogenic adipocytes in regulating body weight or fat mass but points to a pivotal role in regulating metabolic health by improving insulin resistance as well as glucose and lipid homeostasis. This review will therefore focus on the metabolic benefits of BAT activation and the mechanisms and signalling pathways by which these could occur including improvements in insulin signalling in peripheral tissues, systemic lipid and cholesterol metabolism and cardiac and vascular function.
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152
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Pardo F, Villalobos-Labra R, Chiarello DI, Salsoso R, Toledo F, Gutierrez J, Leiva A, Sobrevia L. Molecular implications of adenosine in obesity. Mol Aspects Med 2017; 55:90-101. [PMID: 28104382 DOI: 10.1016/j.mam.2017.01.003] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2016] [Revised: 12/30/2016] [Accepted: 01/13/2017] [Indexed: 12/31/2022]
Abstract
Adenosine has broad activities in organisms due to the existence of multiple receptors, the differential adenosine concentrations necessary to activate these receptors and the presence of proteins able to synthetize, degrade or transport this nucleoside. All adenosine receptors have been reported to be involved in glucose homeostasis, inflammation, adipogenesis, insulin resistance, and thermogenesis, indicating that adenosine could participate in the process of obesity. Since adenosine seems to be associated with several effects, it is plausible that adenosine participates in the initiation and development of obesity or may function to prevent it. Thus, the purpose of this review was to explore the involvement of adenosine in adipogenesis, insulin resistance and thermogenesis, with the aim of understanding how adenosine could be used to avoid, treat or improve the metabolic state of obesity. Treatment with specific agonists and/or antagonists of adenosine receptors could reverse the obesity state, since adenosine receptors normalizes several mechanisms involved in obesity, such as lipolysis, insulin sensitivity and thermogenesis. Furthermore, obesity is a preventable state, and the specific activation of adenosine receptors could aid in the prevention of obesity. Nevertheless, for the treatment of obesity and its consequences, more studies and therapeutic strategies in addition to adenosine are necessary.
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Affiliation(s)
- Fabián Pardo
- Metabolic Diseases Research Laboratory, Center of Research, Development and Innovation in Health - Aconcagua Valley, San Felipe Campus, School of Medicine, Faculty of Medicine, Universidad de Valparaiso, 2172972 San Felipe, Chile; Cellular and Molecular Physiology Laboratory, Division of Obstetrics and Gynaecology, School of Medicine, Faculty of Medicine, Pontificia Universidad Católica de Chile, Santiago 8330024, Chile.
| | - Roberto Villalobos-Labra
- Cellular and Molecular Physiology Laboratory, Division of Obstetrics and Gynaecology, School of Medicine, Faculty of Medicine, Pontificia Universidad Católica de Chile, Santiago 8330024, Chile
| | - Delia I Chiarello
- Cellular and Molecular Physiology Laboratory, Division of Obstetrics and Gynaecology, School of Medicine, Faculty of Medicine, Pontificia Universidad Católica de Chile, Santiago 8330024, Chile
| | - Rocío Salsoso
- Cellular and Molecular Physiology Laboratory, Division of Obstetrics and Gynaecology, School of Medicine, Faculty of Medicine, Pontificia Universidad Católica de Chile, Santiago 8330024, Chile; Department of Physiology, Faculty of Pharmacy, Universidad de Sevilla, Seville E-41012, Spain
| | - Fernando Toledo
- Cellular and Molecular Physiology Laboratory, Division of Obstetrics and Gynaecology, School of Medicine, Faculty of Medicine, Pontificia Universidad Católica de Chile, Santiago 8330024, Chile; Department of Basic Sciences, Faculty of Sciences, Universidad del Bío-Bío, Chillán 3780000, Chile
| | - Jaime Gutierrez
- Cellular and Molecular Physiology Laboratory, Division of Obstetrics and Gynaecology, School of Medicine, Faculty of Medicine, Pontificia Universidad Católica de Chile, Santiago 8330024, Chile; Cellular Signaling Differentiation and Regeneration Laboratory, Health Sciences Faculty, Universidad San Sebastian, Santiago, Chile
| | - Andrea Leiva
- Cellular and Molecular Physiology Laboratory, Division of Obstetrics and Gynaecology, School of Medicine, Faculty of Medicine, Pontificia Universidad Católica de Chile, Santiago 8330024, Chile
| | - Luis Sobrevia
- Cellular and Molecular Physiology Laboratory, Division of Obstetrics and Gynaecology, School of Medicine, Faculty of Medicine, Pontificia Universidad Católica de Chile, Santiago 8330024, Chile; Department of Physiology, Faculty of Pharmacy, Universidad de Sevilla, Seville E-41012, Spain; University of Queensland Centre for Clinical Research, Faculty of Medicine and Biomedical Sciences, University of Queensland, Herston, QLD 4029, Queensland, Australia.
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153
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Ryu V, Watts AG, Xue B, Bartness TJ. Bidirectional crosstalk between the sensory and sympathetic motor systems innervating brown and white adipose tissue in male Siberian hamsters. Am J Physiol Regul Integr Comp Physiol 2017; 312:R324-R337. [PMID: 28077392 DOI: 10.1152/ajpregu.00456.2015] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2015] [Revised: 11/28/2016] [Accepted: 12/31/2016] [Indexed: 01/31/2023]
Abstract
The brain networks connected to the sympathetic motor and sensory innervations of brown (BAT) and white (WAT) adipose tissues were originally described using two transneuronally transported viruses: the retrogradely transported pseudorabies virus (PRV), and the anterogradely transported H129 strain of herpes simplex virus-1 (HSV-1 H129). Further complexity was added to this network organization when combined injections of PRV and HSV-1 H129 into either BAT or WAT of the same animal generated sets of coinfected neurons in the brain, spinal cord, and sympathetic and dorsal root ganglia. These neurons are well positioned to act as sensorimotor links in the feedback circuits that control each fat pad. We have now determined the extent of sensorimotor crosstalk between interscapular BAT (IBAT) and inguinal WAT (IWAT). PRV152 and HSV-1 H129 were each injected into IBAT or IWAT of the same animal: H129 into IBAT and PRV152 into IWAT. The reverse configuration was applied in a different set of animals. We found single-labeled neurons together with H129+PRV152 coinfected neurons in multiple brain sites, with lesser numbers in the sympathetic and dorsal root ganglia that innervate IBAT and IWAT. We propose that these coinfected neurons mediate sensory-sympathetic motor crosstalk between IBAT and IWAT. Comparing the relative numbers of coinfected neurons between the two injection configurations showed a bias toward IBAT-sensory and IWAT-sympathetic motor feedback loops. These coinfected neurons provide a neuroanatomical framework for functional interactions between IBAT thermogenesis and IWAT lipolysis that occurs with cold exposure, food restriction/deprivation, exercise, and more generally with alterations in adiposity.
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Affiliation(s)
- Vitaly Ryu
- Department of Biology, Obesity Reversal Center, Georgia State University, Atlanta, Georgia; and
| | - Alan G Watts
- Department of Biological Sciences, University of Southern California, Dornsife College of Letters, Arts, and Sciences, University of Southern California, Los Angeles, California
| | - Bingzhong Xue
- Department of Biology, Obesity Reversal Center, Georgia State University, Atlanta, Georgia; and
| | - Timothy J Bartness
- Department of Biology, Obesity Reversal Center, Georgia State University, Atlanta, Georgia; and
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154
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Anthanont P, Levine JA, McCrady-Spitzer SK, Jensen MD. Lack of Seasonal Differences in Basal Metabolic Rate in Humans: A Cross-Sectional Study. Horm Metab Res 2017; 49:30-35. [PMID: 27410533 PMCID: PMC5405856 DOI: 10.1055/s-0042-107793] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Some studies indicate that basal metabolic rate is greater in winter than in the summer, suggesting a role for brown fat in human thermogenesis. We examined whether there are clinically meaningful differences in basal metabolic rate under thermoneutral conditions between winter and summer months in inhabitants of Rochester, Minnesota. We collated data from 220 research volunteers studied in the winter (December 1 - February 28) and 214 volunteers studied in the summer (June 1 - August 31), 1995-2012. Basal metabolic rate was measured by indirect calorimetry and body composition by dual-energy X-ray absorptiometry. The effect of season on basal metabolic rate was tested using multivariate regression analysis with basal metabolic rate as the dependent variable and fat-free mass, fat mass, age, sex, and season as the independent variables. The groups were comparable with respect to age, body mass index, fat mass, and fat-free mass. There was no significant difference in basal metabolic rate between winter and summer groups (1 667±322 vs. 1 669±330 kcal/day). Both winter and summer basal metabolic rates were strongly predicted by fat-free mass (Pearson's r=0.75 and r=0.77, respectively, p <0.0001). Using multiple linear regression analysis, basal metabolic rate was significantly, independently predicted by fat-free mass, fat mass, age, and sex, but not season. We conclude that the lack of seasonal variation of thermoneutral basal metabolic rate between winter and summer suggests that modern, Western populations do not engage thermogenically detectable brown fat activity during periods of living in a cold climate.
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Affiliation(s)
- Pimjai Anthanont
- Endocrine Research Unit, Mayo Clinic, 200 1 St SW, Rochester, MN 55905 USA
| | - James A. Levine
- Endocrine Research Unit, Mayo Clinic, 200 1 St SW, Rochester, MN 55905 USA
| | | | - Michael D. Jensen
- Endocrine Research Unit, Mayo Clinic, 200 1 St SW, Rochester, MN 55905 USA
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155
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Riley CL, Dao C, Kenaston MA, Muto L, Kohno S, Nowinski SM, Solmonson AD, Pfeiffer M, Sack MN, Lu Z, Fiermonte G, Sprague JE, Mills EM. The complementary and divergent roles of uncoupling proteins 1 and 3 in thermoregulation. J Physiol 2016; 594:7455-7464. [PMID: 27647490 DOI: 10.1113/jp272971] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2016] [Accepted: 09/15/2016] [Indexed: 01/23/2023] Open
Abstract
KEY POINTS Both uncoupling protein 1 (UCP1) and UCP3 are important for mammalian thermoregulation. UCP1 and UCP3 in brown adipose tissue mediate early and late phases of sympathomimetic thermogenesis, respectively. Lipopolysaccharide thermogenesis requires skeletal muscle UCP3 but not UCP1. Acute noradrenaline-induced hyperthermia requires UCP1 but not UCP3. Loss of both UCP1 and UCP3 accelerate the loss of body temperature compared to UCP1KO alone during acute cold exposure. ABSTRACT Uncoupling protein 1 (UCP1) is the established mediator of brown adipose tissue-dependent thermogenesis. In contrast, the role of UCP3, expressed in both skeletal muscle and brown adipose tissue, in thermoregulatory physiology is less well understood. Here, we show that mice lacking UCP3 (UCP3KO) have impaired sympathomimetic (methamphetamine) and completely abrogated lipopolysaccharide (LPS) thermogenesis, but a normal response to noradrenaline. By comparison, UCP1 knockout (UCP1KO) mice exhibit blunted methamphetamine and fully inhibited noradrenaline thermogenesis, but an increased febrile response to LPS. We further establish that mice lacking both UCP1 and 3 (UCPDK) fail to show methamphetamine-induced hyperthermia, and have a markedly accelerated loss of body temperature and survival after cold exposure compared to UCP1KO mice. Finally, we show that skeletal muscle-specific human UCP3 expression is able to significantly rescue LPS, but not sympathomimetic thermogenesis blunted in UCP3KO mice. These studies identify UCP3 as an important mediator of physiological thermogenesis and support a renewed focus on targeting UCP3 in metabolic physiology.
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Affiliation(s)
- Christopher L Riley
- Department of Molecular Biosciences, College of Natural Sciences, The University of Texas at Austin, Austin, TX, 78712, USA
| | - Christine Dao
- Division of Pharmacy and Toxicology, College of Pharmacy, The University of Texas at Austin, Austin, TX, 78712, USA
| | - M Alexander Kenaston
- Division of Pharmacy and Toxicology, College of Pharmacy, The University of Texas at Austin, Austin, TX, 78712, USA
| | - Luigina Muto
- Department of Pharmacy, Health and Nutritional Sciences, University of Calabria, Cosenza, Italy
| | - Shohei Kohno
- Division of Pharmacy and Toxicology, College of Pharmacy, The University of Texas at Austin, Austin, TX, 78712, USA
| | - Sara M Nowinski
- Department of Biochemistry, The University of Utah, Salt Lake City, UT, 84112, USA
| | - Ashley D Solmonson
- Department of Molecular Biosciences, College of Natural Sciences, The University of Texas at Austin, Austin, TX, 78712, USA.,Division of Pharmacy and Toxicology, College of Pharmacy, The University of Texas at Austin, Austin, TX, 78712, USA
| | - Matthew Pfeiffer
- Division of Pharmacy and Toxicology, College of Pharmacy, The University of Texas at Austin, Austin, TX, 78712, USA
| | - Michael N Sack
- National Heart, Lung, and Blood Institute, Laboratory of Mitochondrial Biology and Metabolism, NIH, Bethesda, MD, 20892, USA
| | - Zhongping Lu
- Cardiovascular and Pulmonary Branch and the Department of Biochemistry and Molecular Medicine, George Washington University, and the Veterans Affairs Medical Center, Washington, DC, 20422, 20052, USA
| | - Giuseppe Fiermonte
- Department of Biosciences, Biotechnologies, and Biopharmaceutics and Center of Excellence in Comparative Genomics, University of Bari, 70125, Bari, Italy
| | - Jon E Sprague
- The Ohio Attorney General's Center for the Future of Forensic Science, Bowling Green State University, Bowling Green, OH, 43403, USA
| | - Edward M Mills
- Division of Pharmacy and Toxicology, College of Pharmacy, The University of Texas at Austin, Austin, TX, 78712, USA
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156
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Muzik O, Mangner TJ, Leonard WR, Kumar A, Granneman JG. Sympathetic Innervation of Cold-Activated Brown and White Fat in Lean Young Adults. J Nucl Med 2016; 58:799-806. [PMID: 27789721 DOI: 10.2967/jnumed.116.180992] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2016] [Accepted: 09/28/2016] [Indexed: 02/07/2023] Open
Abstract
Recent work in rodents has demonstrated that basal activity of the local sympathetic nervous system is critical for maintaining brown adipocyte phenotypes in classic brown adipose tissue (BAT) and white adipose tissue (WAT). Accordingly, we sought to assess the relationship between sympathetic innervation and cold-induced activation of BAT and WAT in lean young adults. Methods: Twenty adult lean normal subjects (10 women and 10 men; mean age ± SD, 23.3 ± 3.8 y; body mass index, 23.7 ± 2.5 kg/m2) underwent 11C-meta-hydroxyephedrin (11C-HED) and 15O-water PET imaging at rest and after exposure to mild cold (16°C) temperature. In addition, 18F-FDG images were obtained during the cold stress condition to assess cold-activated BAT mass. Subjects were divided into 2 groups (high BAT and low BAT) based on the presence of 18F-FDG tracer uptake. Blood flow and 11C-HED retention index (RI, an indirect measure of sympathetic innervation) were calculated from dynamic PET scans at the location of BAT and WAT. Whole-body daily energy expenditure (DEE) during rest and cold stress was measured by indirect calorimetry. Tissue level oxygen consumption (MRO2) was determined and used to calculate the contribution of cold-activated BAT and WAT to daily DEE. Results:18F-FDG uptake identified subjects with high and low levels of cold-activated BAT mass (high BAT, 96 ± 37 g; low-BAT, 16 ± 4 g). 11C-HED RI under thermoneutral conditions significantly predicted 18F-FDG uptake during cold stress (R2 = 0.68, P < 0.01). In contrast to the significant increase of 11C-HED RI during cold in BAT (2.42 ± 0.85 vs. 3.43 ± 0.93, P = 0.02), cold exposure decreased the 11C-HED RI in WAT (0.44 ± 0.22 vs. 0.41 ± 0.18) as a consequence of decreased perfusion (1.22 ± 0.20 vs. 1.12 ± 0.16 mL/100 g/min). The contribution of WAT to whole-body DEE was approximately 150 kcal/d at rest (149 ± 52 kcal/d), which decreased to approximately 100 kcal/d during cold (102 ± 47 kcal/d). Conclusion: The level of sympathetic innervation, as determined by 11C-HED RI, can predict levels of functional BAT. Overall, blood flow is the best independent predictor of 11C-HED RI and 18F-FDG uptake across thermoneutral and cold conditions. In contrast to BAT, cold stress reduces blood flow and 18F-FDG uptake in subcutaneous WAT, indicating that the physiologic response is to reduce heat loss rather than to generate heat.
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Affiliation(s)
- Otto Muzik
- Department of Pediatrics, Wayne State University School of Medicine, Detroit, Michigan .,Department of Radiology, Wayne State University School of Medicine, Detroit, Michigan
| | - Tom J Mangner
- Department of Pediatrics, Wayne State University School of Medicine, Detroit, Michigan
| | - William R Leonard
- Department of Anthropology, Northwestern University, Evanston, Illinois
| | - Ajay Kumar
- Department of Pediatrics, Wayne State University School of Medicine, Detroit, Michigan
| | - James G Granneman
- Center for Molecular Medicine and Genetics, Wayne State University School of Medicine, Detroit, Michigan; and.,Center for Integrative Metabolic and Endocrine Research and Family Medicine
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157
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Chen KY, Cypess AM, Laughlin MR, Haft CR, Hu HH, Bredella MA, Enerbäck S, Kinahan PE, Lichtenbelt WVM, Lin FI, Sunderland JJ, Virtanen KA, Wahl RL. Brown Adipose Reporting Criteria in Imaging STudies (BARCIST 1.0): Recommendations for Standardized FDG-PET/CT Experiments in Humans. Cell Metab 2016; 24:210-22. [PMID: 27508870 PMCID: PMC4981083 DOI: 10.1016/j.cmet.2016.07.014] [Citation(s) in RCA: 214] [Impact Index Per Article: 26.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Human brown adipose tissue (BAT) presence, metabolic activity, and estimated mass are typically measured by imaging [18F]fluorodeoxyglucose (FDG) uptake in response to cold exposure in regions of the body expected to contain BAT, using positron emission tomography combined with X-ray computed tomography (FDG-PET/CT). Efforts to describe the epidemiology and biology of human BAT are hampered by diverse experimental practices, making it difficult to directly compare results among laboratories. An expert panel was assembled by the National Institute of Diabetes and Digestive and Kidney Diseases on November 4, 2014 to discuss minimal requirements for conducting FDG-PET/CT experiments of human BAT, data analysis, and publication of results. This resulted in Brown Adipose Reporting Criteria in Imaging STudies (BARCIST 1.0). Since there are no fully validated best practices at this time, panel recommendations are meant to enhance comparability across experiments, but not to constrain experimental design or the questions that can be asked.
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Affiliation(s)
- Kong Y Chen
- National Institutes of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA.
| | - Aaron M Cypess
- National Institutes of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA.
| | - Maren R Laughlin
- National Institutes of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA.
| | - Carol R Haft
- National Institutes of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | | | - Miriam A Bredella
- Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, USA
| | | | | | | | - Frank I Lin
- National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | | | - Kirsi A Virtanen
- Turku University Hospital, 20500 Turku, Finland; University of Turku, 20500 Turku, Finland
| | - Richard L Wahl
- Washington University School of Medicine, Mallinckrodt Institute of Radiology, Saint Louis, MO 63110, USA
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158
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Abstract
The demonstration of the presence of metabolically active brown adipose tissue (BAT) in adult humans using positron emission tomography (PET) over the past decade has lead to the rapid development of our knowledge regarding the role of BAT in energy metabolism in animal models and in humans. Although animal models continue to provide highly valuable information regarding the mechanisms regulating BAT development, mass and metabolic functions, these studies led to many assumptions that have been at best only partially verified in humans so far. Combined to some limitations of the current investigation approaches used in humans, this has lead to speculation on the potential role of BAT dysfunction in the development of cardiometabolic disorders and on the potential of BAT metabolic activation to treat these conditions. Here we propose a critical review of the evidence for the implication of BAT in cardiometabolic health.
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Affiliation(s)
- Denis P Blondin
- Department of Medicine, Centre de Recherche du Centre Hospitalier Universitaire de Sherbrooke, Université de Sherbrooke, Sherbrooke, Canada
| | - André C Carpentier
- Department of Medicine, Centre de Recherche du Centre Hospitalier Universitaire de Sherbrooke, Université de Sherbrooke, Sherbrooke, Canada.
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159
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Chondronikola M, Volpi E, Børsheim E, Porter C, Saraf MK, Annamalai P, Yfanti C, Chao T, Wong D, Shinoda K, Labbė SM, Hurren NM, Cesani F, Kajimura S, Sidossis LS. Brown Adipose Tissue Activation Is Linked to Distinct Systemic Effects on Lipid Metabolism in Humans. Cell Metab 2016; 23:1200-1206. [PMID: 27238638 PMCID: PMC4967557 DOI: 10.1016/j.cmet.2016.04.029] [Citation(s) in RCA: 242] [Impact Index Per Article: 30.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/24/2014] [Revised: 12/23/2015] [Accepted: 04/28/2016] [Indexed: 02/03/2023]
Abstract
Recent studies suggest that brown adipose tissue (BAT) plays a role in energy and glucose metabolism in humans. However, the physiological significance of human BAT in lipid metabolism remains unknown. We studied 16 overweight/obese men during prolonged, non-shivering cold and thermoneutral conditions using stable isotopic tracer methodologies in conjunction with hyperinsulinemic-euglycemic clamps and BAT and white adipose tissue (WAT) biopsies. BAT volume was significantly associated with increased whole-body lipolysis, triglyceride-free fatty acid (FFA) cycling, FFA oxidation, and adipose tissue insulin sensitivity. Functional analysis of BAT and WAT demonstrated the greater thermogenic capacity of BAT compared to WAT, while molecular analysis revealed a cold-induced upregulation of genes involved in lipid metabolism only in BAT. The accelerated mobilization and oxidation of lipids upon BAT activation supports a putative role for BAT in the regulation of lipid metabolism in humans.
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Affiliation(s)
- Maria Chondronikola
- Metabolism Unit, Shriners Hospitals for Children, Galveston, TX 77555, USA; Department of Preventive Medicine and Community Health, University of Texas Medical Branch, Galveston, TX 77555, USA; Department of Nutrition and Metabolism, Division of Rehabilitation Sciences, University of Texas Medical Branch, Galveston, TX 77555, USA; Department of Nutrition and Dietetics, Harokopio University of Athens, Athens 176 71, Greece
| | - Elena Volpi
- Department of Nutrition and Metabolism, Division of Rehabilitation Sciences, University of Texas Medical Branch, Galveston, TX 77555, USA; Institute for Translational Sciences, University of Texas Medical Branch, Galveston, TX 77555, USA; Sealy Center on Aging, University of Texas Medical Branch, Galveston, TX 77555, USA; Department of Internal Medicine, University of Texas Medical Branch, Galveston, TX 77555, USA
| | - Elisabet Børsheim
- Metabolism Unit, Shriners Hospitals for Children, Galveston, TX 77555, USA; Department of Surgery, University of Texas Medical Branch, Galveston, TX 77555, USA
| | - Craig Porter
- Metabolism Unit, Shriners Hospitals for Children, Galveston, TX 77555, USA; Department of Surgery, University of Texas Medical Branch, Galveston, TX 77555, USA
| | - Manish K Saraf
- Metabolism Unit, Shriners Hospitals for Children, Galveston, TX 77555, USA; Department of Surgery, University of Texas Medical Branch, Galveston, TX 77555, USA
| | - Palam Annamalai
- Department of Interventional Radiology, University of Texas Medical Branch, Galveston, TX 77555, USA
| | - Christina Yfanti
- Metabolism Unit, Shriners Hospitals for Children, Galveston, TX 77555, USA; Sealy Center on Aging, University of Texas Medical Branch, Galveston, TX 77555, USA
| | - Tony Chao
- Metabolism Unit, Shriners Hospitals for Children, Galveston, TX 77555, USA; Department of Preventive Medicine and Community Health, University of Texas Medical Branch, Galveston, TX 77555, USA; Department of Nutrition and Metabolism, Division of Rehabilitation Sciences, University of Texas Medical Branch, Galveston, TX 77555, USA
| | - Daniel Wong
- Diabetes Center, Department of Cell and Tissue Biology, and Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California, San Francisco, CA 94143, USA
| | - Kosaku Shinoda
- Diabetes Center, Department of Cell and Tissue Biology, and Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California, San Francisco, CA 94143, USA
| | - Sebastien M Labbė
- Quebec Heart and Lung Research Institute Centre, Quebec City, Quebec G1V 4G5, Canada
| | - Nicholas M Hurren
- Metabolism Unit, Shriners Hospitals for Children, Galveston, TX 77555, USA; Department of Surgery, University of Texas Medical Branch, Galveston, TX 77555, USA
| | - Fernardo Cesani
- Department of Nuclear Medicine, University of Texas Medical Branch, Galveston, TX 77555-0177, USA
| | - Shingo Kajimura
- Diabetes Center, Department of Cell and Tissue Biology, and Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California, San Francisco, CA 94143, USA
| | - Labros S Sidossis
- Metabolism Unit, Shriners Hospitals for Children, Galveston, TX 77555, USA; Department of Nutrition and Metabolism, Division of Rehabilitation Sciences, University of Texas Medical Branch, Galveston, TX 77555, USA; Department of Nutrition and Dietetics, Harokopio University of Athens, Athens 176 71, Greece; Institute for Translational Sciences, University of Texas Medical Branch, Galveston, TX 77555, USA; Sealy Center on Aging, University of Texas Medical Branch, Galveston, TX 77555, USA; Department of Internal Medicine, University of Texas Medical Branch, Galveston, TX 77555, USA; Department of Exercise Sciences, Rutgers University, New Brunswick, NJ 08901, USA; Department of Medicine, Robert Wood Johnson Medical School, Rutgers University, New Brunswick, NJ 08901, USA.
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160
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Bal NC, Maurya SK, Singh S, Wehrens XHT, Periasamy M. Increased Reliance on Muscle-based Thermogenesis upon Acute Minimization of Brown Adipose Tissue Function. J Biol Chem 2016; 291:17247-57. [PMID: 27298322 DOI: 10.1074/jbc.m116.728188] [Citation(s) in RCA: 70] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2016] [Indexed: 12/22/2022] Open
Abstract
Skeletal muscle has been suggested as a site of nonshivering thermogenesis (NST) besides brown adipose tissue (BAT). Studies in birds, which do not contain BAT, have demonstrated the importance of skeletal muscle-based NST. However, muscle-based NST in mammals remains poorly characterized. We recently reported that sarco/endoplasmic reticulum Ca(2+) cycling and that its regulation by SLN can be the basis for muscle NST. Because of the dominant role of BAT-mediated thermogenesis in rodents, the role of muscle-based NST is less obvious. In this study, we investigated whether muscle will become an important site of NST when BAT function is conditionally minimized in mice. We surgically removed interscapular BAT (iBAT, which constitutes ∼70% of total BAT) and exposed the mice to prolonged cold (4 °C) for 9 days. The iBAT-ablated mice were able to maintain optimal body temperature (∼35-37 °C) during the entire period of cold exposure. After 4 days in the cold, both sham controls and iBAT-ablated mice stopped shivering and resumed routine physical activity, indicating that they are cold-adapted. The iBAT-ablated mice showed higher oxygen consumption and decreased body weight and fat mass, suggesting an increased energy cost of cold adaptation. The skeletal muscles in these mice underwent extensive remodeling of both the sarcoplasmic reticulum and mitochondria, including alteration in the expression of key components of Ca(2+) handling and mitochondrial metabolism. These changes, along with increased sarcolipin expression, provide evidence for the recruitment of NST in skeletal muscle. These studies collectively suggest that skeletal muscle becomes the major site of NST when BAT activity is minimized.
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Affiliation(s)
- Naresh C Bal
- From the Sanford Burnham Prebys Medical Discovery Institute at Lake Nona, Orlando, Florida 32827, the Department of Physiology and Cell Biology, College of Medicine, Ohio State University, Columbus, Ohio 43210, the School of Biotechnology, KIIT University, Bhubaneswar, Odisha, India 751024, and
| | - Santosh K Maurya
- From the Sanford Burnham Prebys Medical Discovery Institute at Lake Nona, Orlando, Florida 32827, the Department of Physiology and Cell Biology, College of Medicine, Ohio State University, Columbus, Ohio 43210
| | - Sushant Singh
- From the Sanford Burnham Prebys Medical Discovery Institute at Lake Nona, Orlando, Florida 32827, the Department of Physiology and Cell Biology, College of Medicine, Ohio State University, Columbus, Ohio 43210
| | - Xander H T Wehrens
- the Cardiovascular Research Institute, Departments of Molecular Physiology and Biophysics, Medicine, and Pediatrics, Baylor College of Medicine, Houston, Texas 77030
| | - Muthu Periasamy
- From the Sanford Burnham Prebys Medical Discovery Institute at Lake Nona, Orlando, Florida 32827, the Department of Physiology and Cell Biology, College of Medicine, Ohio State University, Columbus, Ohio 43210
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Schilperoort M, Hoeke G, Kooijman S, Rensen PCN. Relevance of lipid metabolism for brown fat visualization and quantification. Curr Opin Lipidol 2016; 27:242-8. [PMID: 27023630 DOI: 10.1097/mol.0000000000000296] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
PURPOSE OF REVIEW Brown adipose tissue (BAT) is an emerging target to combat cardiometabolic disorders as it can take up substantial amounts of glucose and lipids from the circulation for heat production. This review focuses on new concepts in BAT physiology and discusses the need for new techniques to determine BAT activity in humans. RECENT FINDINGS Mouse studies showed that BAT activation selectively increases oxidation of lipids over glucose, by recruiting fatty acids from intracellular triglycerides. To replenish these intracellular lipid stores, brown adipocytes take up both glucose and triglyceride-derived fatty acids, resulting in attenuation of dyslipidaemia, insulin resistance and atherosclerosis. Clinical studies identified the involvement of the β3-adrenergic receptor in BAT activation and demonstrated that human BAT activation also selectively increases lipid oxidation. Notably, insulin resistance during ageing or weight gain reduces the capacity of BAT to internalize glucose, without reducing fatty acid uptake or oxidative metabolism. SUMMARY Preclinical studies established BAT as an important target to combat cardiometabolic disorders and elucidated underlying mechanisms whereas clinical studies identified therapeutic handles. Development of novel lipid-based PET-CT tracers and identification of translational biomarkers of BAT activity are required as alternatives to [F]fluorodeoxyglucose PET-CT to accelerate clinical development of BAT-activating therapeutic strategies.
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Affiliation(s)
- Maaike Schilperoort
- Department of Medicine, Division of Endocrinology, and Einthoven Laboratory for Experimental Vascular Medicine, Leiden University Medical Center, Leiden, The Netherlands
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Hanssen MJW, van der Lans AAJJ, Brans B, Hoeks J, Jardon KMC, Schaart G, Mottaghy FM, Schrauwen P, van Marken Lichtenbelt WD. Short-term Cold Acclimation Recruits Brown Adipose Tissue in Obese Humans. Diabetes 2016; 65:1179-89. [PMID: 26718499 DOI: 10.2337/db15-1372] [Citation(s) in RCA: 201] [Impact Index Per Article: 25.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/01/2015] [Accepted: 12/17/2015] [Indexed: 12/11/2022]
Abstract
Recruitment of brown adipose tissue (BAT) has emerged as a potential tool to combat obesity and associated metabolic complications. Short-term cold acclimation has been shown not only to enhance the presence and activity of BAT in lean humans but also to improve the metabolic profile of skeletal muscle to benefit glucose uptake in patients with type 2 diabetes. Here we examined whether short-term cold acclimation also induced such adaptations in 10 metabolically healthy obese male subjects. A 10-day cold acclimation period resulted in increased cold-induced glucose uptake in BAT, as assessed by [(18)F]fluorodeoxyglucose positron emission tomography/computed tomography. BAT activity was negatively related to age, with a similar trend for body fat percentage. In addition, cold-induced glucose uptake in BAT was positively related to glucose uptake in visceral white adipose tissue, although glucose uptake in visceral and subcutaneous white adipose tissue depots was unchanged upon cold acclimation. Cold-induced skeletal muscle glucose uptake tended to increase upon cold acclimation, which was paralleled by increased basal GLUT4 localization in the sarcolemma, as assessed through muscle biopsies. Proximal skin temperature was increased and subjective responses to cold were slightly improved at the end of the acclimation period. These metabolic adaptations to prolonged exposure to mild cold may lead to improved glucose metabolism or prevent the development of obesity-associated insulin resistance and hyperglycemia.
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Affiliation(s)
- Mark J W Hanssen
- Departments of Human Biology and Human Movement Sciences, NUTRIM School for Nutrition and Translational Research in Metabolism, Maastricht University Medical Center, Maastricht, the Netherlands
| | - Anouk A J J van der Lans
- Departments of Human Biology and Human Movement Sciences, NUTRIM School for Nutrition and Translational Research in Metabolism, Maastricht University Medical Center, Maastricht, the Netherlands
| | - Boudewijn Brans
- Department of Nuclear Medicine, Maastricht University Medical Center, Maastricht, the Netherlands
| | - Joris Hoeks
- Departments of Human Biology and Human Movement Sciences, NUTRIM School for Nutrition and Translational Research in Metabolism, Maastricht University Medical Center, Maastricht, the Netherlands
| | - Kelly M C Jardon
- Departments of Human Biology and Human Movement Sciences, NUTRIM School for Nutrition and Translational Research in Metabolism, Maastricht University Medical Center, Maastricht, the Netherlands
| | - Gert Schaart
- Departments of Human Biology and Human Movement Sciences, NUTRIM School for Nutrition and Translational Research in Metabolism, Maastricht University Medical Center, Maastricht, the Netherlands
| | - Felix M Mottaghy
- Department of Nuclear Medicine, Maastricht University Medical Center, Maastricht, the Netherlands Department of Nuclear Medicine, University Hospital Rheinisch-Westfälische Technische Hochschule Aachen, Aachen, Germany
| | - Patrick Schrauwen
- Departments of Human Biology and Human Movement Sciences, NUTRIM School for Nutrition and Translational Research in Metabolism, Maastricht University Medical Center, Maastricht, the Netherlands
| | - Wouter D van Marken Lichtenbelt
- Departments of Human Biology and Human Movement Sciences, NUTRIM School for Nutrition and Translational Research in Metabolism, Maastricht University Medical Center, Maastricht, the Netherlands
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Thoonen R, Hindle AG, Scherrer-Crosbie M. Brown adipose tissue: The heat is on the heart. Am J Physiol Heart Circ Physiol 2016; 310:H1592-605. [PMID: 27084389 DOI: 10.1152/ajpheart.00698.2015] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/01/2015] [Accepted: 04/13/2016] [Indexed: 12/17/2022]
Abstract
The study of brown adipose tissue (BAT) has gained significant scientific interest since the discovery of functional BAT in adult humans. The thermogenic properties of BAT are well recognized; however, data generated in the last decade in both rodents and humans reveal therapeutic potential for BAT against metabolic disorders and obesity. Here we review the current literature in light of a potential role for BAT in beneficially mediating cardiovascular health. We focus mainly on BAT's actions in obesity, vascular tone, and glucose and lipid metabolism. Furthermore, we discuss the recently discovered endocrine factors that have a potential beneficial role in cardiovascular health. These BAT-secreted factors may have a favorable effect against cardiovascular risk either through their metabolic role or by directly affecting the heart.
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Affiliation(s)
- Robrecht Thoonen
- Cardiovascular Research Center, Massachusetts General Hospital, Boston, Massachusetts
| | - Allyson G Hindle
- Department of Anesthesia and Critical Pain Medicine, Massachusetts General Hospital, Boston, Massachusetts; and
| | - Marielle Scherrer-Crosbie
- Cardiovascular Research Center, Massachusetts General Hospital, Boston, Massachusetts; Cardiac Ultrasound Laboratory, Massachusetts General Hospital, Boston, Massachusetts
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164
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165
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Yoneshiro T, Matsushita M, Nakae S, Kameya T, Sugie H, Tanaka S, Saito M. Brown adipose tissue is involved in the seasonal variation of cold-induced thermogenesis in humans. Am J Physiol Regul Integr Comp Physiol 2016; 310:R999-R1009. [PMID: 27030666 DOI: 10.1152/ajpregu.00057.2015] [Citation(s) in RCA: 61] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2015] [Accepted: 03/17/2016] [Indexed: 02/03/2023]
Abstract
Brown adipose tissue (BAT) contributes to whole-body energy expenditure (EE), especially cold-induced thermogenesis (CIT), in humans. Although it is known that EE and CIT vary seasonally, their relationship with BAT has not been investigated. In the present study, we examined the impact of BAT on seasonal variations of EE/CIT and thermal responses to cold exposure in a randomized crossover design. Forty-five healthy male volunteers participated, and their BAT was assessed by positron emission tomography and computed tomography. CIT, the difference of EE at 27ºC and after 2-h cold exposure at 19ºC, significantly increased in winter compared to summer, being greater in subjects with metabolically active BAT (High BAT, 185.6 kcal/d, 18.3 kcal/d, P<0.001) than those without (Low BAT, 90.6 kcal/d, -46.5 kcal/d, P<0.05). Multivariate regression analysis revealed a significant interaction effect between season and BAT on CIT (P<0.001). The cold-induced drop of tympanic temperature (Tty) and skin temperature (Tskin) in the forehead region and in the supraclavicular region close to BAT deposits were smaller in the High BAT group than in the Low BAT group in winter but not in summer. In contrast, the drop of Tskinin the subclavicular and peripheral regions distant from BAT was similar in the two groups in both seasons. In conclusion, CIT increased from summer to winter in a BAT-dependent manner, paralleling cold-induced changes in Tty/Tskin, indicating a role of BAT in seasonal changes in the thermogenic and thermal responses to cold exposure in humans.
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166
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Human brown adipose tissue [(15)O]O2 PET imaging in the presence and absence of cold stimulus. Eur J Nucl Med Mol Imaging 2016; 43:1878-86. [PMID: 26993316 PMCID: PMC4969352 DOI: 10.1007/s00259-016-3364-y] [Citation(s) in RCA: 92] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2015] [Accepted: 03/08/2016] [Indexed: 12/22/2022]
Abstract
Purpose Brown adipose tissue (BAT) is considered a potential target for combatting obesity, as it produces heat instead of ATP in cellular respiration due to uncoupling protein-1 (UCP-1) in mitochondria. However, BAT-specific thermogenic capacity, in comparison to whole-body thermogenesis during cold stimulus, is still controversial. In our present study, we aimed to determine human BAT oxygen consumption with [15O]O2 positron emission tomography (PET) imaging. Further, we explored whether BAT-specific energy expenditure (EE) is associated with BAT blood flow, non-esterified fatty acid (NEFA) uptake, and whole-body EE. Methods Seven healthy study subjects were studied at two different scanning sessions, 1) at room temperature (RT) and 2) with acute cold exposure. Radiotracers [15O]O2, [15O]H2O, and [18F]FTHA were given for the measurements of BAT oxygen consumption, blood flow, and NEFA uptake, respectively, with PET-CT. Indirect calorimetry was performed to assess differences in whole-body EE between RT and cold. Results BAT-specific EE and oxygen consumption was higher during cold stimulus (approx. 50 %); similarly, whole-body EE was higher during cold stimulus (range 2–47 %). However, there was no association in BAT-specific EE and whole-body EE. BAT-specific EE was found to be a minor contributor in cold induced whole-body thermogenesis (almost 1 % of total whole-body elevation in EE). Certain deep muscles in the cervico-thoracic region made a major contribution to this cold-induced thermogenesis (CIT) without any visual signs or individual perception of shivering. Moreover, BAT-specific EE associated with BAT blood flow and NEFA uptake both at RT and during cold stimulus. Conclusion Our study suggests that BAT is a minor and deep muscles are a major contributor to CIT. In BAT, both in RT and during cold, cellular respiration is linked with circulatory NEFA uptake. Electronic supplementary material The online version of this article (doi:10.1007/s00259-016-3364-y) contains supplementary material, which is available to authorized users.
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167
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Solmonson A, Mills EM. Uncoupling Proteins and the Molecular Mechanisms of Thyroid Thermogenesis. Endocrinology 2016; 157:455-62. [PMID: 26636187 PMCID: PMC4733119 DOI: 10.1210/en.2015-1803] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/15/2015] [Accepted: 12/01/2015] [Indexed: 12/21/2022]
Affiliation(s)
- A Solmonson
- Institute for Cellular and Molecular Biology (A.S., E.M.M.), College of Natural Sciences and Division of Pharmacology and Toxicology (E.M.M.), College of Pharmacy, The University of Texas at Austin, Austin, Texas 78712
| | - E M Mills
- Institute for Cellular and Molecular Biology (A.S., E.M.M.), College of Natural Sciences and Division of Pharmacology and Toxicology (E.M.M.), College of Pharmacy, The University of Texas at Austin, Austin, Texas 78712
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168
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Peterson CM, Lecoultre V, Frost EA, Simmons J, Redman LM, Ravussin E. The thermogenic responses to overfeeding and cold are differentially regulated. Obesity (Silver Spring) 2016; 24:96-101. [PMID: 26592725 PMCID: PMC4688067 DOI: 10.1002/oby.21233] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/15/2015] [Revised: 06/22/2015] [Accepted: 06/23/2015] [Indexed: 01/19/2023]
Abstract
OBJECTIVE Brown adipose tissue (BAT) is a highly metabolic tissue that generates heat and is negatively associated with obesity. BAT has been proposed to mediate both cold-induced thermogenesis (CIT) and diet-induced thermogenesis (DIT). Therefore, it was investigated whether there is a relationship between CIT and DIT in humans. METHODS Nine healthy men (23 ± 3 years old, 23.0 ± 1.8 kg m(-2) ) completed 20 min of cold exposure (4°C) 5 days per week for 4 weeks. Before and after the intervention, CIT (the increase in resting metabolic rate at 16°C relative to 22°C) was measured by a ventilated hood indirect calorimeter, whereas DIT was measured as the 24-h thermic response to 1 day of 50% overfeeding (TEF150% ) in a respiratory chamber. RESULTS After the cold intervention, CIT more than doubled from 5.2% ± 14.2% at baseline to 12.0% ± 11.1% (P = 0.05), in parallel with increased sympathetic nervous system activity. However, 24-h energy expenditure (2,166 ± 206 vs. 2,118 ± 188 kcal day(-1) ; P = 0.15) and TEF150% (7.4% ± 2.7% vs. 7.7% ± 1.6%; P = 0.78) were unchanged. Moreover, there was no association between CIT and TEF150% at baseline or post-intervention, nor in their changes (P ≥ 0.47). CONCLUSIONS Cold acclimation resulted in increased CIT but not TEF150% . Therefore, it is likely that CIT and DIT are mediated by distinct regulatory mechanisms.
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Affiliation(s)
- Courtney M. Peterson
- Pennington Biomedical Research Center, 6400 Perkins Road, Baton Rouge, LA 70808, USA
| | - Virgile Lecoultre
- Pennington Biomedical Research Center, 6400 Perkins Road, Baton Rouge, LA 70808, USA
- Faculty of Sciences, Department of Medicine, University of Fribourg, Switzerland
| | - Elizabeth A. Frost
- Pennington Biomedical Research Center, 6400 Perkins Road, Baton Rouge, LA 70808, USA
| | - Jonathan Simmons
- Pennington Biomedical Research Center, 6400 Perkins Road, Baton Rouge, LA 70808, USA
| | - Leanne M. Redman
- Pennington Biomedical Research Center, 6400 Perkins Road, Baton Rouge, LA 70808, USA
| | - Eric Ravussin
- Pennington Biomedical Research Center, 6400 Perkins Road, Baton Rouge, LA 70808, USA
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Nahon KJ, Boon MR, Bakker LE, Prehn C, Adamski J, Jazet IM, van Dijk KW, Rensen PC, Mook-Kanamori DO. Physiological changes due to mild cooling in healthy lean males of white Caucasian and South Asian descent: A metabolomics study. Arch Biochem Biophys 2016; 589:152-7. [DOI: 10.1016/j.abb.2015.09.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2015] [Revised: 08/20/2015] [Accepted: 09/01/2015] [Indexed: 10/23/2022]
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170
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Abstract
Obesity drugs have had a chequered history. In the recent past, only the low efficacy, pancreatic lipase inhibitor orlistat was available worldwide and it was little used. The 5HT2C agonist, lorcaserin, and two combinations of old drugs have been approved in the United States but not in Europe. The diabetes drug liraglutide has been approved in both the US and Europe and seems likely to be most widely accepted. In view of regulators' caution in approving obesity drugs, some (like beloranib) may initially be progressed for niche obesity markets. New drug targets have been identified in brown adipose tissue with the aim of not only activating thermogenesis but also increasing the capacity for thermogenesis in this tissue. Attempts are being made to match the efficacy of bariatric surgery by mimicking multiple gut hormones. Unapproved pharmacotherapies are tempting for some patients. Others remain optimistic about more conventional routes to pharmacotherapy.
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Affiliation(s)
- Jonathan R S Arch
- Clore Laboratory, Buckingham Institute for Translational Medicine, University of Buckingham, Hunter Street, Buckingham, MK18 1EG, UK.
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171
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Can thermogenic adipocytes protect from obesity? J Physiol Biochem 2015; 71:847-53. [PMID: 26482272 DOI: 10.1007/s13105-015-0443-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2015] [Accepted: 10/08/2015] [Indexed: 10/22/2022]
Abstract
The role of brown adipocytes and adipocytes of a new beige type in the energy metabolism of a healthy person and in the pathogenesis of obesity has extensively been discussed in recent years. The interest to these cells has been stimulated owing to the application of new noninvasive methods for studying the metabolic activity of tissues. Using these methods, the presence of thermogenically active adipocytes in adults and their reactivity to cold stimuli have been proved. These data, together with the results of animal experiments support the idea of thermogenic fat being a direct regulator of the energy balance of man. However, for several reasons there are some objections to this viewpoint. The main objection is that the total activity of the human thermogenic adipocytes is about 100 kJ/day, i.e., it is negligible. In addition, the burn of excessive nutrients is biologically inappropriate for an organism. Therefore, the idea that obesity is caused by the decreased activity of thermogenic adipocytes is erroneous. The statement that the causes of obesity are associated with the increased efficiency of energy-dependent processes seems more reasonable. The consequence is a reduction in energy expenditure to perform a unit of biological work. This results in excess of nutrients deposited in the form of fat.
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172
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McMillan AC, White MD. Induction of thermogenesis in brown and beige adipose tissues: molecular markers, mild cold exposure and novel therapies. Curr Opin Endocrinol Diabetes Obes 2015; 22:347-52. [PMID: 26313896 DOI: 10.1097/med.0000000000000191] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
PURPOSE OF REVIEW The purpose of this short review paper is to summarize recent developments in the understanding of the activation, growth and function of brown adipose tissue (BAT). RECENT FINDINGS Transcriptional markers for increased BAT activity and differentiation of white adipocytes to 'beige' or 'brite' adipocytes include amongst others peroxisome proliferator-activated receptor γ, cytosine-enhancer-binding protein, positive regulatory domain 16 and bone morphogenetic proteins. These markers induce uncoupling protein 1 expression in brown and 'beige' or 'brite' adipocytes which allows energy from macronutrients to be expended as heat. Acute and repeated mild cold exposures of 17-19 °C in adult humans increase BAT volume and activity and this is a novel method for increasing their energy expenditure. Emerging evidence suggests that irisin and melatonin hormones may be involved in BAT activation. Additionally, brown adipocyte stem cell therapy transplantation is a means to stimulate this increased thermogenesis from brown and 'beige' or 'brite' adipocytes. SUMMARY Markers for increased BAT activation and for white adipocyte differentiation into beige/brite adipocytes have been identified, and these lead to an uncoupling protein 1-mediated increase in metabolic rate. Mild cold exposure and brown adipocyte stem cell transplantation are two potential strategies for inducing activation and growth of BAT for the treatment of human obesity.
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Affiliation(s)
- Andrew C McMillan
- Department of Biomedical Physiology and Kinesiology, Simon Fraser University, Burnaby, British Columbia, Canada
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173
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Carpentier AC. Acute Adaptation of Energy Expenditure Predicts Diet-Induced Weight Loss: Revisiting the Thrifty Phenotype. Diabetes 2015. [PMID: 26207037 DOI: 10.2337/db15-0553] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Affiliation(s)
- André C Carpentier
- Division of Endocrinology, Department of Medicine, Centre de Recherche du Centre Hospitalier Universitaire de Sherbrooke, Université de Sherbrooke, Sherbrooke, Quebec, Canada
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174
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Blondin DP, Labbé SM, Noll C, Kunach M, Phoenix S, Guérin B, Turcotte ÉE, Haman F, Richard D, Carpentier AC. Selective Impairment of Glucose but Not Fatty Acid or Oxidative Metabolism in Brown Adipose Tissue of Subjects With Type 2 Diabetes. Diabetes 2015; 64:2388-97. [PMID: 25677914 DOI: 10.2337/db14-1651] [Citation(s) in RCA: 164] [Impact Index Per Article: 18.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/28/2014] [Accepted: 02/05/2015] [Indexed: 11/13/2022]
Abstract
Spontaneous glucose uptake by brown adipose tissue (BAT) is lower in overweight or obese individuals and in diabetes. However, BAT metabolism has not been previously investigated in patients with type 2 diabetes during controlled cold exposure. Using positron emission tomography with (11)C-acetate, (18)F-fluoro-deoxyglucose ((18)FDG), and (18)F-fluoro-thiaheptadecanoic acid ((18)FTHA), a fatty acid tracer, BAT oxidative metabolism and perfusion and glucose and nonesterified fatty acid (NEFA) turnover were determined in men with well-controlled type 2 diabetes and age-matched control subjects under experimental cold exposure designed to minimize shivering. Despite smaller volumes of (18)FDG-positive BAT and lower glucose uptake per volume of BAT compared with young healthy control subjects, cold-induced oxidative metabolism and NEFA uptake per BAT volume and an increase in total body energy expenditure did not differ in patients with type 2 diabetes or their age-matched control subjects. The reduction in (18)FDG-positive BAT volume and BAT glucose clearance were associated with a reduction in BAT radiodensity and perfusion. (18)FDG-positive BAT volume and the cold-induced increase in BAT radiodensity were associated with an increase in systemic NEFA turnover. These results show that cold-induced NEFA uptake and oxidative metabolism are not defective in type 2 diabetes despite reduced glucose uptake per BAT volume and BAT "whitening."
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Affiliation(s)
- Denis P Blondin
- Department of Medicine, Centre de Recherche du Centre hospitalier universitaire de Sherbrooke, Université de Sherbrooke, Quebec, Canada
| | - Sébastien M Labbé
- Centre de Recherche de l'Institut Universitaire de Cardiologie et de Pneumologie de Québec, Université Laval, Quebec City, Quebec, Canada
| | - Christophe Noll
- Department of Medicine, Centre de Recherche du Centre hospitalier universitaire de Sherbrooke, Université de Sherbrooke, Quebec, Canada
| | - Margaret Kunach
- Department of Medicine, Centre de Recherche du Centre hospitalier universitaire de Sherbrooke, Université de Sherbrooke, Quebec, Canada
| | - Serge Phoenix
- Department of Medicine, Centre de Recherche du Centre hospitalier universitaire de Sherbrooke, Université de Sherbrooke, Quebec, Canada Department of Nuclear Medicine and Radiobiology, Université de Sherbrooke, Sherbrooke, Quebec, Canada
| | - Brigitte Guérin
- Department of Nuclear Medicine and Radiobiology, Université de Sherbrooke, Sherbrooke, Quebec, Canada
| | - Éric E Turcotte
- Department of Nuclear Medicine and Radiobiology, Université de Sherbrooke, Sherbrooke, Quebec, Canada
| | - François Haman
- Faculty of Health Sciences, University of Ottawa, Ottawa, Ontario, Canada
| | - Denis Richard
- Centre de Recherche de l'Institut Universitaire de Cardiologie et de Pneumologie de Québec, Université Laval, Quebec City, Quebec, Canada
| | - André C Carpentier
- Department of Medicine, Centre de Recherche du Centre hospitalier universitaire de Sherbrooke, Université de Sherbrooke, Quebec, Canada
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175
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Blondin DP, Labbé SM, Turcotte EE, Haman F, Richard D, Carpentier AC. A critical appraisal of brown adipose tissue metabolism in humans. ACTA ACUST UNITED AC 2015. [DOI: 10.2217/clp.15.14] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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176
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Abstract
There are three different types of adipose tissue (AT)-brown, white, and beige-that differ with stage of development, species, and anatomical location. Of these, brown AT (BAT) is the least abundant but has the greatest potential impact on energy balance. BAT is capable of rapidly producing large amounts of heat through activation of the unique uncoupling protein 1 (UCP1) located within the inner mitochondrial membrane. White AT is an endocrine organ and site of lipid storage, whereas beige AT is primarily white but contains some cells that possess UCP1. BAT first appears in the fetus around mid-gestation and is then gradually lost through childhood, adolescence, and adulthood. We focus on the interrelationships between adipocyte classification, anatomical location, and impact of diet in early life together with the extent to which fat development differs between the major species examined. Ultimately, novel dietary interventions designed to reactivate BAT could be possible.
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Affiliation(s)
- Michael E Symonds
- Division of Child Health, Obstetrics and Gynaecology, School of Medicine, University of Nottingham, Nottingham NG7 2UH, United Kingdom; , ,
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177
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McGlashon JM, Gorecki MC, Kozlowski AE, Thirnbeck CK, Markan KR, Leslie KL, Kotas ME, Potthoff MJ, Richerson GB, Gillum MP. Central serotonergic neurons activate and recruit thermogenic brown and beige fat and regulate glucose and lipid homeostasis. Cell Metab 2015; 21:692-705. [PMID: 25955206 PMCID: PMC4565052 DOI: 10.1016/j.cmet.2015.04.008] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/25/2014] [Revised: 02/10/2015] [Accepted: 04/03/2015] [Indexed: 01/06/2023]
Abstract
Thermogenic brown and beige adipocytes convert chemical energy to heat by metabolizing glucose and lipids. Serotonin (5-HT) neurons in the CNS are essential for thermoregulation and accordingly may control metabolic activity of thermogenic fat. To test this, we generated mice in which the human diphtheria toxin receptor (DTR) was selectively expressed in central 5-HT neurons. Treatment with diphtheria toxin (DT) eliminated 5-HT neurons and caused loss of thermoregulation, brown adipose tissue (BAT) steatosis, and a >50% decrease in uncoupling protein 1 (Ucp1) expression in BAT and inguinal white adipose tissue (WAT). In parallel, blood glucose increased 3.5-fold, free fatty acids 13.4-fold, and triglycerides 6.5-fold. Similar BAT and beige fat defects occurred in Lmx1b(f/f)ePet1(Cre) mice in which 5-HT neurons fail to develop in utero. We conclude 5-HT neurons play a major role in regulating glucose and lipid homeostasis, in part through recruitment and metabolic activation of brown and beige adipocytes.
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Affiliation(s)
- Jacob M McGlashon
- Department of Neurology, University of Iowa Carver College of Medicine, Iowa City, IA 52242, USA; Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, 2200 Copenhagen, Denmark; Institute of Biomedical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Michelle C Gorecki
- Department of Neurology, University of Iowa Carver College of Medicine, Iowa City, IA 52242, USA; Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, 2200 Copenhagen, Denmark; Institute of Biomedical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Amanda E Kozlowski
- Department of Neurology, University of Iowa Carver College of Medicine, Iowa City, IA 52242, USA
| | - Caitlin K Thirnbeck
- Department of Neurology, University of Iowa Carver College of Medicine, Iowa City, IA 52242, USA
| | - Kathleen R Markan
- Department of Pharmacology, University of Iowa Carver College of Medicine, Iowa City, IA 52242, USA
| | - Kirstie L Leslie
- Department of Neurology, University of Iowa Carver College of Medicine, Iowa City, IA 52242, USA
| | - Maya E Kotas
- Department of Medicine, Columbia University College of Physicians and Surgeons, New York, NY 10032, USA
| | - Matthew J Potthoff
- Department of Pharmacology, University of Iowa Carver College of Medicine, Iowa City, IA 52242, USA
| | - George B Richerson
- Department of Neurology, University of Iowa Carver College of Medicine, Iowa City, IA 52242, USA; Department of Molecular Physiology & Biophysics, University of Iowa Carver College of Medicine, Iowa City, IA 52242, USA; Veterans Affairs Medical Center, Iowa City, IA 52242, USA
| | - Matthew P Gillum
- Department of Neurology, University of Iowa Carver College of Medicine, Iowa City, IA 52242, USA; Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, 2200 Copenhagen, Denmark; Institute of Biomedical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark.
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178
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The Role of Muscle Mass, Muscle Quality, and Body Composition in Risk for the Metabolic Syndrome and Functional Decline in Older Adults. CURRENT GERIATRICS REPORTS 2015. [DOI: 10.1007/s13670-015-0132-y] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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179
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Abstract
In mammals, a thermogenic mechanism exists that increases heat production and consumes energy. Recent work has shed light on the cellular and physiological mechanisms that control this thermogenic circuit. Thermogenically active adipocytes, namely brown and closely related beige adipocytes, differentiate from progenitor cells that commit to the thermogenic lineage but can arise from different cellular origins. Thermogenic differentiation shares some features with general adipogenesis, highlighting the critical role that common transcription factors may play in progenitors with divergent fates. However, thermogenic differentiation is also discrete from the common adipogenic program and, excitingly, cells with distinct origins possess thermogenic competency that allows them to differentiate into thermogenically active mature adipocytes. An understanding of this thermogenic differentiation program and the factors that can activate it has led to the development of assays that are able to measure thermogenic activity both indirectly and directly. By combining these assays with appropriate cell models, novel therapeutic approaches to combat obesity and its related metabolic disorders by enhancing the thermogenic circuit can be developed.
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Affiliation(s)
- Matthew D Lynes
- Section on Integrative Physiology and Metabolism, Joslin Diabetes Center, Harvard Medical School, Boston, MA, USA
| | - Yu-Hua Tseng
- Section on Integrative Physiology and Metabolism, Joslin Diabetes Center, Harvard Medical School, Boston, MA, USA
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180
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Peng XR, Gennemark P, O’Mahony G, Bartesaghi S. Unlock the Thermogenic Potential of Adipose Tissue: Pharmacological Modulation and Implications for Treatment of Diabetes and Obesity. Front Endocrinol (Lausanne) 2015; 6:174. [PMID: 26635723 PMCID: PMC4657528 DOI: 10.3389/fendo.2015.00174] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/26/2015] [Accepted: 10/28/2015] [Indexed: 12/19/2022] Open
Abstract
Brown adipose tissue (BAT) is considered an interesting target organ for the treatment of metabolic disease due to its high metabolic capacity. Non-shivering thermogenesis, once activated, can lead to enhanced partitioning and oxidation of fuels in adipose tissues, and reduce the burden of glucose and lipids on other metabolic organs such as liver, pancreas, and skeletal muscle. Sustained long-term activation of BAT may also lead to meaningful bodyweight loss. In this review, we discuss three different drug classes [the thiazolidinedione (TZD) class of PPARγ agonists, β3-adrenergic receptor agonists, and fibroblast growth factor 21 (FGF21) analogs] that have been proposed to regulate BAT and beige recruitment or activation, or both, and which have been tested in both rodent and human. The learnings from these classes suggest that restoration of functional BAT and beige mass as well as improved activation might be required to fully realize the metabolic potential of these tissues. Whether this can be achieved without the undesired cardiovascular side effects exhibited by the TZD PPARγ agonists and β3-adrenergic receptor agonists remains to be resolved.
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Affiliation(s)
- Xiao-Rong Peng
- Cardiovascular and Metabolic Diseases IMED Biotech Unit, Diabetes Bioscience Department, AstraZeneca R&D, Mölndal, Sweden
- *Correspondence: Xiao-Rong Peng,
| | - Peter Gennemark
- Cardiovascular and Metabolic Diseases IMED Biotech Unit, Drug Metabolism and Pharmacokinetics Department, AstraZeneca R&D, Mölndal, Sweden
| | - Gavin O’Mahony
- Cardiovascular and Metabolic Diseases IMED Biotech Unit, Medicinal Chemistry Department, AstraZeneca R&D, Mölndal, Sweden
| | - Stefano Bartesaghi
- Cardiovascular and Metabolic Diseases IMED Biotech Unit, Diabetes Bioscience Department, AstraZeneca R&D, Mölndal, Sweden
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