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Abstract
Brown adipose tissue (BAT) displays the unique capacity to generate heat through uncoupled oxidative phosphorylation that makes it a very attractive therapeutic target for cardiometabolic diseases. Here, we review BAT cellular metabolism, its regulation by the central nervous and endocrine systems and circulating metabolites, the plausible roles of this tissue in human thermoregulation, energy balance, and cardiometabolic disorders, and the current knowledge on its pharmacological stimulation in humans. The current definition and measurement of BAT in human studies relies almost exclusively on BAT glucose uptake from positron emission tomography with 18F-fluorodeoxiglucose, which can be dissociated from BAT thermogenic activity, as for example in insulin-resistant states. The most important energy substrate for BAT thermogenesis is its intracellular fatty acid content mobilized from sympathetic stimulation of intracellular triglyceride lipolysis. This lipolytic BAT response is intertwined with that of white adipose (WAT) and other metabolic tissues, and cannot be independently stimulated with the drugs tested thus far. BAT is an interesting and biologically plausible target that has yet to be fully and selectively activated to increase the body's thermogenic response and shift energy balance. The field of human BAT research is in need of methods able to directly, specifically, and reliably measure BAT thermogenic capacity while also tracking the related thermogenic responses in WAT and other tissues. Until this is achieved, uncertainty will remain about the role played by this fascinating tissue in human cardiometabolic diseases.
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Affiliation(s)
- André C Carpentier
- Correspondence: André C. Carpentier, MD, Division of Endocrinology, Faculty of Medicine, University of Sherbrooke, 3001, 12th Ave N, Sherbrooke, Quebec, J1H 5N4, Canada.
| | - Denis P Blondin
- Division of Neurology, Department of Medicine, Centre de recherche du Centre hospitalier universitaire de Sherbrooke, Université de Sherbrooke, Sherbrooke, Quebec, J1H 5N4, Canada
| | | | - Denis Richard
- Centre de recherche de l’Institut universitaire de cardiologie et de pneumologie de Québec, Université Laval, Quebec City, Quebec, G1V 4G5, Canada
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2
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Nuclear Receptors in Energy Metabolism. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2022; 1390:61-82. [DOI: 10.1007/978-3-031-11836-4_4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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3
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Castro É, Vieira TS, Oliveira TE, Ortiz-Silva M, Andrade ML, Tomazelli CA, Peixoto AS, Sobrinho CR, Moreno MF, Gilio GR, Moreira RJ, Guimarães RC, Perandini LA, Chimin P, Reckziegel P, Moretti EH, Steiner AA, Laplante M, Festuccia WT. Adipocyte-specific mTORC2 deficiency impairs BAT and iWAT thermogenic capacity without affecting glucose uptake and energy expenditure in cold-acclimated mice. Am J Physiol Endocrinol Metab 2021; 321:E592-E605. [PMID: 34541875 DOI: 10.1152/ajpendo.00587.2020] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Deletion of mechanistic target of rapamycin complex 2 (mTORC2) essential component rapamycin insensitive companion of mTOR (Rictor) by a Cre recombinase under control of the broad, nonadipocyte-specific aP2/FABP4 promoter impairs thermoregulation and brown adipose tissue (BAT) glucose uptake on acute cold exposure. We investigated herein whether adipocyte-specific mTORC2 deficiency affects BAT and inguinal white adipose tissue (iWAT) signaling, metabolism, and thermogenesis in cold-acclimated mice. For this, 8-wk-old male mice bearing Rictor deletion and therefore mTORC2 deficiency in adipocytes (adiponectin-Cre) and littermates controls were either kept at thermoneutrality (30 ± 1°C) or cold-acclimated (10 ± 1°C) for 14 days and evaluated for BAT and iWAT signaling, metabolism, and thermogenesis. Cold acclimation inhibited mTORC2 in BAT and iWAT, but its residual activity is still required for the cold-induced increases in BAT adipocyte number, total UCP-1 content and mRNA levels of proliferation markers Ki67 and cyclin 1 D, and de novo lipogenesis enzymes ATP-citrate lyase and acetyl-CoA carboxylase. In iWAT, mTORC2 residual activity is partially required for the cold-induced increases in multilocular adipocytes, mitochondrial mass, and uncoupling protein 1 (UCP-1) content. Conversely, BAT mTORC1 activity and BAT and iWAT glucose uptake were upregulated by cold independently of mTORC2. Noteworthy, the impairment in BAT and iWAT total UCP-1 content and thermogenic capacity induced by adipocyte mTORC2 deficiency had no major impact on whole body energy expenditure in cold-acclimated mice due to a compensatory activation of muscle shivering. In conclusion, adipocyte mTORC2 deficiency impairs, through different mechanisms, BAT and iWAT total UCP-1 content and thermogenic capacity in cold-acclimated mice, without affecting glucose uptake and whole body energy expenditure.NEW & NOTEWORTHY BAT and iWAT mTORC2 is inhibited by cold acclimation, but its residual activity is required for cold-induced increases in total UCP-1 content and thermogenic capacity, but not glucose uptake and mTORC1 activity. The impaired BAT and iWAT total UCP-1 content and thermogenic capacity induced by adipocyte mTORC2 deficiency are compensated by activation of muscle shivering in cold-acclimated mice.
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Affiliation(s)
- Érique Castro
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo, Brazil
| | - Thayna S Vieira
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo, Brazil
| | - Tiago E Oliveira
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo, Brazil
| | - Milene Ortiz-Silva
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo, Brazil
| | - Maynara L Andrade
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo, Brazil
| | - Caroline A Tomazelli
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo, Brazil
| | - Albert S Peixoto
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo, Brazil
| | - Cleyton R Sobrinho
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo, Brazil
| | - Mayara F Moreno
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo, Brazil
| | - Gustavo R Gilio
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo, Brazil
| | - Rafael J Moreira
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo, Brazil
| | - Raphael C Guimarães
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo, Brazil
| | - Luiz A Perandini
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo, Brazil
| | - Patricia Chimin
- Department of Physical Education, Physical Education and Sports Center, Londrina State University, Parana, Brazil
| | - Patricia Reckziegel
- Department of Pharmacology, Escola Paulista de Medicina, Universidade Federal de São Paulo (UNIFESP), Sao Paulo, Brazil
| | - Eduardo H Moretti
- Department of Immunology, Institute of Biomedical Sciences, University of São Paulo, Sao Paulo, Brazil
| | - Alexandre A Steiner
- Department of Immunology, Institute of Biomedical Sciences, University of São Paulo, Sao Paulo, Brazil
| | - Mathieu Laplante
- Institut Universitaire de Cardiologie et de Pneumologie de Quebec, Université Laval, Quebec, Quebec, Canada
- Centre de recherche sur le cancer de l'Université Laval, Université Laval, Québec, Quebec, Canada
| | - William T Festuccia
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo, Brazil
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PPARs-Orchestrated Metabolic Homeostasis in the Adipose Tissue. Int J Mol Sci 2021; 22:ijms22168974. [PMID: 34445679 PMCID: PMC8396609 DOI: 10.3390/ijms22168974] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2021] [Revised: 08/17/2021] [Accepted: 08/17/2021] [Indexed: 01/12/2023] Open
Abstract
It has been more than three decades since peroxisome proliferator-activated receptors (PPARs) were first discovered. Many investigations have revealed the central regulators of PPARs in lipid and glucose homeostasis in response to different nutrient conditions. PPARs have attracted much attention due to their ability to improve metabolic syndromes, and they have also been proposed as classical drug targets for the treatment of hyperlipidemia and type 2 diabetes (T2D) mellitus. In parallel, adipose tissue is known to play a unique role in the pathogenesis of insulin resistance and metabolic syndromes due to its ability to “safely” store lipids and secrete cytokines that regulate whole-body metabolism. Adipose tissue relies on a complex and subtle network of transcription factors to maintain its normal physiological function, by coordinating various molecular events, among which PPARs play distinctive and indispensable roles in adipocyte differentiation, lipid metabolism, adipokine secretion, and insulin sensitivity. In this review, we discuss the characteristics of PPARs with special emphasis on the roles of the different isotypes in adipocyte biology.
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Dwaib HS, AlZaim I, Eid AH, Obeid O, El-Yazbi AF. Modulatory Effect of Intermittent Fasting on Adipose Tissue Inflammation: Amelioration of Cardiovascular Dysfunction in Early Metabolic Impairment. Front Pharmacol 2021; 12:626313. [PMID: 33897419 PMCID: PMC8062864 DOI: 10.3389/fphar.2021.626313] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2020] [Accepted: 02/18/2021] [Indexed: 12/15/2022] Open
Abstract
Cardiometabolic syndrome (CMS) is a cluster of maladaptive cardiovascular, renal, thrombotic, inflammatory, and metabolic disorders. It confers a high risk of cardiovascular mortality and morbidity. CMS is triggered by major shifts in lifestyle and dietary habits with increased consumption of refined, calorie-dense diets. Evidence indicates that diet-induced CMS is linked to Adipose tissue (AT) inflammation. This led to the proposal that adipose inflammation may be involved in metabolic derangements, such as insulin resistance and poor glycemic control, as well as the contribution to the inflammatory process predisposing patients to increased cardiovascular risk. Therefore, in the absence of direct pharmacological interventions for the subclinical phase of CMS, time restricted feeding regimens were anticipated to alleviate early metabolic damage and subsequent comorbidities. These regimens, referred to as intermittent fasting (IF), showed a strong positive impact on the metabolic state of obese and non-obese human subjects and animal models, positive AT remodeling in face of overnutrition and high fat diet (HFD) consumption, and improved CV outcomes. Here, we summarize the available evidence on the role of adipose inflammation in triggering cardiovascular impairment in the context of diet induced CMS with an emphasis on the involvement of perivascular adipose tissue. As well, we propose some possible molecular pathways linking intermittent fasting to the ameliorative effect on adipose inflammation and cardiovascular dysfunction under such circumstances. We highlight a number of targets, whose function changes in perivascular adipose tissue inflammation and could be modified by intermittent fasting acting as a novel approach to ameliorate the inflammatory status.
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Affiliation(s)
- Haneen S Dwaib
- Department of Pharmacology and Toxicology, Faculty of Medicine, American University of Beirut, Beirut, Lebanon.,Department of Nutrition and Food Sciences, Faculty of Agricultural and Food Sciences, American University of Beirut, Beirut, Lebanon
| | - Ibrahim AlZaim
- Department of Pharmacology and Toxicology, Faculty of Medicine, American University of Beirut, Beirut, Lebanon.,Department of Biochemistry and Molecular Genetics, Faculty of Medicine, American University of Beirut, Beirut, Lebanon
| | - Ali H Eid
- Department of Basic Medical Sciences, College of Medicine, QU Health, Qatar University, Doha, Qatar.,Biomedical and Pharmaceutical Research Unit, QU Health, Qatar University, Doha, Qatar
| | - Omar Obeid
- Department of Nutrition and Food Sciences, Faculty of Agricultural and Food Sciences, American University of Beirut, Beirut, Lebanon
| | - Ahmed F El-Yazbi
- Department of Pharmacology and Toxicology, Faculty of Medicine, American University of Beirut, Beirut, Lebanon.,Department of Pharmacology and Toxicology, Faculty of Pharmacy, Alexandria University, Alexandria, Egypt.,Faculty of Pharmacy, Al-Alamein International University, Alamein, Egypt
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6
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Thermogenic adipocytes: lineage, function and therapeutic potential. Biochem J 2020; 477:2071-2093. [PMID: 32539124 PMCID: PMC7293110 DOI: 10.1042/bcj20200298] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2020] [Revised: 05/13/2020] [Accepted: 05/15/2020] [Indexed: 12/12/2022]
Abstract
Metabolic inflexibility, defined as the inability to respond or adapt to metabolic demand, is now recognised as a driving factor behind many pathologies associated with obesity and the metabolic syndrome. Adipose tissue plays a pivotal role in the ability of an organism to sense, adapt to and counteract environmental changes. It provides a buffer in times of nutrient excess, a fuel reserve during starvation and the ability to resist cold-stress through non-shivering thermogenesis. Recent advances in single-cell RNA sequencing combined with lineage tracing, transcriptomic and proteomic analyses have identified novel adipocyte progenitors that give rise to specialised adipocytes with diverse functions, some of which have the potential to be exploited therapeutically. This review will highlight the common and distinct functions of well-known adipocyte populations with respect to their lineage and plasticity, as well as introducing the most recent members of the adipocyte family and their roles in whole organism energy homeostasis. Finally, this article will outline some of the more preliminary findings from large data sets generated by single-cell transcriptomics of mouse and human adipose tissue and their implications for the field, both for discovery and for therapy.
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Song HD, Kim SN, Saha A, Ahn SY, Akindehin S, Son Y, Cho YK, Kim M, Park JH, Jung YS, Lee YH. Aging-Induced Brain-Derived Neurotrophic Factor in Adipocyte Progenitors Contributes to Adipose Tissue Dysfunction. Aging Dis 2020; 11:575-587. [PMID: 32489703 PMCID: PMC7220283 DOI: 10.14336/ad.2019.0810] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2019] [Accepted: 08/10/2019] [Indexed: 12/22/2022] Open
Abstract
Aging-related adipose tissue dysfunction contributes to the progression of chronic metabolic diseases. We investigated the role of age-dependent expression of a neurotrophin, brain-derived neurotrophic factor (BDNF) in adipose tissue. Pro-BDNF expression was elevated in epididymal white adipose tissue (eWAT) with advanced age, which was associated with the reduction in sympathetic innervation. Interestingly, BDNF expression was enriched in PDGFRα+ adipocyte progenitors isolated from eWAT, with age-dependent increase in expression. In vitro pro-BDNF treatment caused apoptosis in adipocytes differentiated from C3H10T1/2 cells, and siRNA knockdown of sortilin mitigated these effects. Tamoxifen-inducible PDGFRα+ cell-specific deletion of BDNF (BDNFPdgfra KO) reduced pro-BDNF expression in eWAT, prevented age-associated declines in sympathetic innervation and mitochondrial content in eWAT, and improved insulin sensitivity. Moreover, BDNFPdgfra KO mice showed reduced expression of aging-induced inflammation and senescence markers in eWAT. Collectively, these results identified the upregulation of pro-BDNF expression in adipocyte progenitors as a feature of visceral white adipose tissue aging and suggested that inhibition of BDNF expression in adipocyte progenitors is potentially beneficial to prevent aging-related adipose tissue dysfunction.
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Affiliation(s)
- Hyun-Doo Song
- 1College of Pharmacy, Yonsei University, Incheon, Republic of Korea
| | - Sang Nam Kim
- 2College of Pharmacy and Research Institute of Pharmaceutical Sciences, Seoul National University, Seoul, Republic of Korea
| | - Abhirup Saha
- 2College of Pharmacy and Research Institute of Pharmaceutical Sciences, Seoul National University, Seoul, Republic of Korea
| | - Sang-Yeop Ahn
- 1College of Pharmacy, Yonsei University, Incheon, Republic of Korea
| | - Seun Akindehin
- 1College of Pharmacy, Yonsei University, Incheon, Republic of Korea
| | - Yeonho Son
- 2College of Pharmacy and Research Institute of Pharmaceutical Sciences, Seoul National University, Seoul, Republic of Korea
| | - Yoon Keun Cho
- 2College of Pharmacy and Research Institute of Pharmaceutical Sciences, Seoul National University, Seoul, Republic of Korea
| | - MinSu Kim
- 2College of Pharmacy and Research Institute of Pharmaceutical Sciences, Seoul National University, Seoul, Republic of Korea
| | - Ji-Hyun Park
- 2College of Pharmacy and Research Institute of Pharmaceutical Sciences, Seoul National University, Seoul, Republic of Korea
| | - Young-Suk Jung
- 3College of Pharmacy, Pusan National University, Busan, Republic of Korea
| | - Yun-Hee Lee
- 2College of Pharmacy and Research Institute of Pharmaceutical Sciences, Seoul National University, Seoul, Republic of Korea
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8
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Iwase M, Tokiwa S, Seno S, Mukai T, Yeh YS, Takahashi H, Nomura W, Jheng HF, Matsumura S, Kusudo T, Osato N, Matsuda H, Inoue K, Kawada T, Goto T. Glycerol kinase stimulates uncoupling protein 1 expression by regulating fatty acid metabolism in beige adipocytes. J Biol Chem 2020; 295:7033-7045. [PMID: 32273338 DOI: 10.1074/jbc.ra119.011658] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2019] [Revised: 04/02/2020] [Indexed: 11/06/2022] Open
Abstract
Browning of adipose tissue is induced by specific stimuli such as cold exposure and consists of up-regulation of thermogenesis in white adipose tissue. Recently, it has emerged as an attractive target for managing obesity in humans. Here, we performed a comprehensive analysis to identify genes associated with browning in murine adipose tissue. We focused on glycerol kinase (GYK) because its mRNA expression pattern is highly correlated with that of uncoupling protein 1 (UCP1), which regulates the thermogenic capacity of adipocytes. Cold exposure-induced Ucp1 up-regulation in inguinal white adipose tissue (iWAT) was partially abolished by Gyk knockdown (KD) in vivo Consistently, the Gyk KD inhibited Ucp1 expression induced by treatment with the β-adrenergic receptors (βAR) agonist isoproterenol (Iso) in vitro and resulted in impaired uncoupled respiration. Gyk KD also suppressed Iso- and adenylate cyclase activator-induced transcriptional activation and phosphorylation of the cAMP response element-binding protein (CREB). However, we did not observe these effects with a cAMP analog. Therefore Gyk KD related to Iso-induced cAMP products. In Iso-treated Gyk KD adipocytes, stearoyl-CoA desaturase 1 (SCD1) was up-regulated, and monounsaturated fatty acids such as palmitoleic acid (POA) accumulated. Moreover, a SCD1 inhibitor treatment recovered the Gyk KD-induced Ucp1 down-regulation and POA treatment down-regulated Iso-activated Ucp1 Our findings suggest that Gyk stimulates Ucp1 expression via a mechanism that partially depends on the βAR-cAMP-CREB pathway and Gyk-mediated regulation of fatty acid metabolism.
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Affiliation(s)
- Mari Iwase
- Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Uji, Kyoto 611-0011, Japan
| | - Soshi Tokiwa
- Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Uji, Kyoto 611-0011, Japan
| | - Shigeto Seno
- Department of Bioinformatic Engineering, Graduate School of Information Science and Technology, Osaka University, Suita 565-0871, Japan
| | - Takako Mukai
- Faculty of Human Sciences, Tezukayama Gakuin University, Sakai 590-0113, Japan
| | - Yu-Sheng Yeh
- Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Uji, Kyoto 611-0011, Japan
| | - Haruya Takahashi
- Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Uji, Kyoto 611-0011, Japan
| | - Wataru Nomura
- Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Uji, Kyoto 611-0011, Japan.,Research Unit for Physiological Chemistry, Center for the Promotion of Interdisciplinary Education and Research, Kyoto University, Kyoto 606-8317, Japan
| | - Huei-Fen Jheng
- Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Uji, Kyoto 611-0011, Japan
| | - Sigenobu Matsumura
- Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Uji, Kyoto 611-0011, Japan
| | - Tatsuya Kusudo
- Faculty of Human Sciences, Tezukayama Gakuin University, Sakai 590-0113, Japan
| | - Naoki Osato
- Department of Bioinformatic Engineering, Graduate School of Information Science and Technology, Osaka University, Suita 565-0871, Japan
| | - Hideo Matsuda
- Department of Bioinformatic Engineering, Graduate School of Information Science and Technology, Osaka University, Suita 565-0871, Japan
| | - Kazuo Inoue
- Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Uji, Kyoto 611-0011, Japan
| | - Teruo Kawada
- Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Uji, Kyoto 611-0011, Japan.,Research Unit for Physiological Chemistry, Center for the Promotion of Interdisciplinary Education and Research, Kyoto University, Kyoto 606-8317, Japan
| | - Tsuyoshi Goto
- Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Uji, Kyoto 611-0011, Japan .,Research Unit for Physiological Chemistry, Center for the Promotion of Interdisciplinary Education and Research, Kyoto University, Kyoto 606-8317, Japan
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9
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Abstract
Animals that lack the hormone leptin become grossly obese, purportedly for 2 reasons: increased food intake and decreased energy expenditure (thermogenesis). This review examines the experimental evidence for the thermogenesis component. Analysis of the data available led us to conclude that the reports indicating hypometabolism in the leptin-deficient ob/ob mice (as well as in the leptin-receptor-deficient db/db mice and fa/fa rats) derive from a misleading calculation artefact resulting from expression of energy expenditure per gram of body weight and not per intact organism. Correspondingly, the body weight-reducing effects of leptin are not augmented by enhanced thermogenesis. Congruent with this, there is no evidence that the ob/ob mouse demonstrates atrophied brown adipose tissue or diminished levels of total UCP1 mRNA or protein when the ob mutation is studied on the inbred C57BL/6 mouse background, but a reduced sympathetic nerve activity is observed. On the outbred "Aston" mouse background, brown adipose tissue atrophy is seen, but whether this is of quantitative significance for the development of obesity has not been demonstrated. We conclude that leptin is not a thermogenic hormone. Rather, leptin has effects on body temperature regulation, by opposing torpor bouts and by shifting thermoregulatory thresholds. The central pathways behind these effects are largely unexplored.
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Affiliation(s)
- Alexander W Fischer
- Department of Molecular Biosciences, The Wenner-Gren Institute, The Arrhenius Laboratories F3, Stockholm University, Stockholm, Sweden.,Department of Biochemistry and Molecular Cell Biology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Barbara Cannon
- Department of Molecular Biosciences, The Wenner-Gren Institute, The Arrhenius Laboratories F3, Stockholm University, Stockholm, Sweden
| | - Jan Nedergaard
- Department of Molecular Biosciences, The Wenner-Gren Institute, The Arrhenius Laboratories F3, Stockholm University, Stockholm, Sweden
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de-Lima-Júnior JC, Rodovalho S, Van de Sande-Lee S, Monfort-Pires M, Rachid B, Cintra RM, Ramos CD, Cendes F, Folli F, Velloso LA. Effect of pioglitazone treatment on brown adipose tissue volume and activity and hypothalamic gliosis in patients with type 2 diabetes mellitus: a proof-of-concept study. Acta Diabetol 2019; 56:1333-1339. [PMID: 31506721 DOI: 10.1007/s00592-019-01418-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Accepted: 08/29/2019] [Indexed: 02/06/2023]
Abstract
AIMS This study aimed to evaluate the effect of pioglitazone on brown adipose tissue function and hypothalamic gliosis in humans. Brown adipose tissue and the hypothalamus are regarded as important potential pharmacological targets to metabolic diseases, and defining the impact of current therapies on their structure and/or function could provide therapeutic advance in this field. METHODS Six patients with type 2 diabetes were treated for 24 weeks with pioglitazone 30 mg/day as an add-on therapy. Brown adipose tissue glucose uptake and volume were determined using 18F-FDG PET/CT scans; hypothalamic gliosis was determined using MRI scans; blood was collected for hormone and biochemistry measurements. All tests were performed at inclusion and six months after pioglitazone introduction. RESULTS Pioglitazone treatment led to a significant 3% body mass increase. There were neither changes in cold-induced brown adipose tissue glucose uptake and volume nor changes in hypothalamic gliosis. CONCLUSIONS This is a proof-of-concept study that provides clinical evidence for a lack of action of a thiazolidinedione, pioglitazone, to promote homogeneous and measurable changes in brown adipose tissue volume and also in hypothalamic gliosis after 6 months of treatment.
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Affiliation(s)
- José C de-Lima-Júnior
- Laboratory of Cell Signaling, Department of Internal Medicine, University of Campinas (UNICAMP), Campinas, São Paulo, Brazil
- Obesity and Comorbidities Research Center, Campinas, São Paulo, Brazil
| | - Sylka Rodovalho
- Laboratory of Cell Signaling, Department of Internal Medicine, University of Campinas (UNICAMP), Campinas, São Paulo, Brazil
- Obesity and Comorbidities Research Center, Campinas, São Paulo, Brazil
| | - Simone Van de Sande-Lee
- Laboratory of Cell Signaling, Department of Internal Medicine, University of Campinas (UNICAMP), Campinas, São Paulo, Brazil
- Department of Internal Medicine, Federal University of Santa Catarina (UFSC), Florianópolis, SC, Brazil
| | - Milena Monfort-Pires
- Laboratory of Cell Signaling, Department of Internal Medicine, University of Campinas (UNICAMP), Campinas, São Paulo, Brazil
- Obesity and Comorbidities Research Center, Campinas, São Paulo, Brazil
| | - Briana Rachid
- Laboratory of Cell Signaling, Department of Internal Medicine, University of Campinas (UNICAMP), Campinas, São Paulo, Brazil
- Obesity and Comorbidities Research Center, Campinas, São Paulo, Brazil
| | - Riobaldo M Cintra
- Obesity and Comorbidities Research Center, Campinas, São Paulo, Brazil
| | - Celso D Ramos
- Department of Radiology, University of Campinas, Campinas, São Paulo, 13084-970, Brazil
| | - Fernando Cendes
- Neuroimaging Laboratory, Department of Neurology, University of Campinas, Campinas, Brazil
| | - Franco Folli
- Obesity and Comorbidities Research Center, Campinas, São Paulo, Brazil
- School of Medicine, Endocrinology and Metabolism Dipartimento di Scienze Della Salute, Universita' degli Studi di Milano, Milan, Italy
- Departmental Unit of Diabetes and Metabolic Disorders, Azienda Socio-Sanitaria Santi Paolo e Carlo, Via A. Di Rudini, 8, 20143, Milan, Italy
| | - Lício A Velloso
- Laboratory of Cell Signaling, Department of Internal Medicine, University of Campinas (UNICAMP), Campinas, São Paulo, Brazil.
- Obesity and Comorbidities Research Center, Campinas, São Paulo, Brazil.
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11
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Jia P, Wu X, Pan T, Xu S, Hu J, Ding X. Uncoupling protein 1 inhibits mitochondrial reactive oxygen species generation and alleviates acute kidney injury. EBioMedicine 2019; 49:331-340. [PMID: 31678001 PMCID: PMC6945195 DOI: 10.1016/j.ebiom.2019.10.023] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2019] [Revised: 10/05/2019] [Accepted: 10/14/2019] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND Uncoupling protein 1 (UCP1) is predominantly found in brown adipose tissue mitochondria, and mediates energy dissipation to generate heat rather than ATP via functional mitochondrial uncoupling. However, little is known about its expression and function in kidney. METHODS We carried out a mRNA microarray analysis in mice kidneys with ischemia reperfusion (IR) injury. The most dramatically downregulated gene UCP1 after IR was identified, and its role in generation of mitochondrial reactive oxygen species (ROS) and oxidative stress injury was assessed both in vitro and in vivo. Genetic deletion of UCP1 was used to investigate the effects of UCP1 on ischemia or cisplatin-indued acute kidney injury (AKI) in mice. FINDINGS UCP1 was located in renal tubular epithelial cells in kidney and downregulated in a time-dependent manner during renal IR. Deletion of UCP1 increased oxidative stress in kidneys and aggravated ischemia or cisplatin induced AKI in mice.Viral-based overexpression of UCP1 reduced mitochondrial ROS generation and apoptosis in hypoxia-treated tubular epithelial cells. Furthermore, UCP1 expression was regulated by peroxisome proliferator-activator receptor (PPAR) γ in kidneys during renal IR. Overexpression of PPAR-γ resembled UCP1-overexpression phenotype in vitro. Treatment with PPAR-γ agonist could induce UCP1 upregulation and provide protective effect against renal IR injury in UCP1+/+mice, but not in UCP1-/-mice. INTERPRETATION UCP1 protects against AKI likely by suppressing oxidative stress, and activation of UCP1 represents a potential therapeutic strategy for AKI. FUND: National Natural Science Foundation of China grants, Science and Technology Commission of Shanghai.
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Affiliation(s)
- Ping Jia
- Division of Nephrology, Zhongshan Hospital, Fudan University, Shanghai, China; Kidney and Blood Purification Laboratory of Shanghai, Shanghai, China
| | - Xiaoli Wu
- Traditional Chinese Medicine Pharmacology Laboratory, Longhua Hospital, Shanghai University of Tranditional Chinese Medicine, Shanghai, China
| | - Tianyi Pan
- Division of Nephrology, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Sujuan Xu
- Division of Nephrology, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Jiachang Hu
- Division of Nephrology, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Xiaoqiang Ding
- Division of Nephrology, Zhongshan Hospital, Fudan University, Shanghai, China; Shanghai Medical Center of Kidney, Shanghai, China; Kidney and Dialysis Institute of Shanghai, Shanghai, China; Kidney and Blood Purification Laboratory of Shanghai, Shanghai, China; Hemodialysis quality control center of Shanghai, Shanghai, China.
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12
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Norepinephrine transporter availability in brown fat is reduced in obesity: a human PET study with [ 11C] MRB. Int J Obes (Lond) 2019; 44:964-967. [PMID: 31636373 DOI: 10.1038/s41366-019-0471-4] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/11/2019] [Revised: 09/19/2019] [Accepted: 09/30/2019] [Indexed: 01/08/2023]
Abstract
The energy-dissipating properties of brown adipose tissue (BAT) have been proposed as therapeutic targets for obesity and diabetes. Little is known about basal BAT activity. Capitalizing on the dense sympathetic innervation of BAT, we have previously shown that BAT can be detected in humans under resting room temperature (RT) conditions by using (S,S)-11C-O-methylreboxetine (MRB), a selective ligand for the norepinephrine transporter (NET). In this study, we determine whether MRB labeling of human BAT is altered by obesity. Fifteen healthy, nondiabetic Caucasian women (nine lean, age 25.6 ± 1.7, BMI 21.8 ± 1.3 kg/m2; six obese age 30.8 ± 8.8 BMI 37.9 ± 6.6 kg/m2) underwent PET-CT imaging of the neck/supraclavicular region using 11C-MRB under RT conditions. The distribution volume ratio (DVR) for 11C-MRB was estimated via multilinear reference tissue model 2 (MRTM2) referenced to the occipital cortex. Two women (one lean and one with obesity) had no detectable BAT. Of the women with detectable BAT, women with obesity had lower 11C-MRB DVR (0.80 ± 0.12 BAT DVR) compared to lean (1.15 ± 0.19 BAT DVR) (p = 0.004). Our findings are consistent with reports that NET is decreased in obesity and suggest that the sympathetic innervation of BAT is altered in obesity.
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13
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Programming mediated by fatty acids affects uncoupling protein 1 (UCP-1) in brown adipose tissue. Br J Nutr 2019; 120:619-627. [PMID: 30176958 DOI: 10.1017/s0007114518001629] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Brown adipose tissue (BAT) has recently been given more attention for the part it plays in obesity. BAT can generate great amounts of heat through thermogenesis by the activation of uncoupling protein 1 (UCP-1), which can be regulated by many environmental factors such as diet. Moreover, the build-up of BAT relates to maternal nutritional changes during pregnancy and lactation. However, at present, there is a limited number of studies looking at maternal nutrition and BAT development, and it seems that the research trend in this field has been considerably declining since the 1980s. There is much to discover yet about the role of different fatty acids on the development of BAT and the activation of UCP-1 during the fetal and the postnatal periods of life. A better understanding of the impact of nutritional intervention on the epigenetic regulation of BAT could lead to new preventive care for metabolic diseases such as obesity. It is important to know in which circumstances lipids could programme BAT during pregnancy and lactation. The modification of maternal dietary fatty acids, amount and composition, during pregnancy and lactation might be a promising strategy for the prevention of obesity in the offspring and future generations.
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14
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Peroxisome Proliferator Activated Receptor Gamma Controls Mature Brown Adipocyte Inducibility through Glycerol Kinase. Cell Rep 2019; 22:760-773. [PMID: 29346772 DOI: 10.1016/j.celrep.2017.12.067] [Citation(s) in RCA: 78] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2017] [Revised: 10/03/2017] [Accepted: 12/20/2017] [Indexed: 01/08/2023] Open
Abstract
Peroxisome proliferator-activated receptors (PPARs) have been suggested as the master regulators of adipose tissue formation. However, their role in regulating brown fat functionality has not been resolved. To address this question, we generated mice with inducible brown fat-specific deletions of PPARα, β/δ, and γ, respectively. We found that both PPARα and β/δδ are dispensable for brown fat function. In contrast, we could show that ablation of PPARγ in vitro and in vivo led to a reduced thermogenic capacity accompanied by a loss of inducibility by β-adrenergic signaling, as well as a shift from oxidative fatty acid metabolism to glucose utilization. We identified glycerol kinase (Gyk) as a partial mediator of PPARγ function and could show that Gyk expression correlates with brown fat thermogenic capacity in human brown fat biopsies. Thus, Gyk might constitute the link between PPARγ-mediated regulation of brown fat function and activation by β-adrenergic signaling.
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15
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François M, Torres H, Huesing C, Zhang R, Saurage C, Lee N, Qualls-Creekmore E, Yu S, Morrison CD, Burk D, Berthoud HR, Münzberg H. Sympathetic innervation of the interscapular brown adipose tissue in mouse. Ann N Y Acad Sci 2019; 1454:3-13. [PMID: 31184376 PMCID: PMC6810755 DOI: 10.1111/nyas.14119] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Revised: 04/05/2019] [Accepted: 04/24/2019] [Indexed: 12/11/2022]
Abstract
The recent discovery of significant brown fat depots in adult humans has revived discussion of exploiting brown fat thermogenesis in the control of energy balance and body weight. The sympathetic nervous system (SNS) has a key role in the activation of brown fat and functional mapping of its components will be crucial for the development of specific neuromodulation techniques. The mouse is an important species used for molecular genetic modulations, but its small size is not ideal for anatomical dissections, thus brown fat innervation studies are mostly available in larger rodents such as rats and hamsters. Here, we use pseudorabies virus retrograde tracing, whole tissue clearing, and confocal/light sheet microscopy to show the location of pre- and postganglionic neurons selectively innervating the interscapular brown adipose tissue (iBAT) in the mouse. Using iDISCO whole tissue clearing, we identified iBAT projecting postganglionic neurons in the caudal parts of the ipsilateral fused stellate/T1, as well as the T2-T5 sympathetic chain ganglia and preganglionic neurons between levels T2 and T6 of the ipsilateral spinal cord. The methodology enabled high-resolution imaging and 3D rendering of the specific SNS innervation of iBAT and will be helpful to discern peripheral nervous system innervation of other organs and tissues.
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Affiliation(s)
- Marie François
- Neurobiology of Nutrition and Metabolism Department, Pennington Biomedical Research Center, Louisiana State University System, Baton Rouge, Louisiana
| | - Hayden Torres
- Neurobiology of Nutrition and Metabolism Department, Pennington Biomedical Research Center, Louisiana State University System, Baton Rouge, Louisiana
| | - Clara Huesing
- Neurobiology of Nutrition and Metabolism Department, Pennington Biomedical Research Center, Louisiana State University System, Baton Rouge, Louisiana
| | - Rui Zhang
- Neurobiology of Nutrition and Metabolism Department, Pennington Biomedical Research Center, Louisiana State University System, Baton Rouge, Louisiana
| | - Carson Saurage
- Neurobiology of Nutrition and Metabolism Department, Pennington Biomedical Research Center, Louisiana State University System, Baton Rouge, Louisiana
| | - Nathan Lee
- Neurobiology of Nutrition and Metabolism Department, Pennington Biomedical Research Center, Louisiana State University System, Baton Rouge, Louisiana
| | - Emily Qualls-Creekmore
- Neurobiology of Nutrition and Metabolism Department, Pennington Biomedical Research Center, Louisiana State University System, Baton Rouge, Louisiana
| | - Sangho Yu
- Neurobiology of Nutrition and Metabolism Department, Pennington Biomedical Research Center, Louisiana State University System, Baton Rouge, Louisiana
| | - Christopher D Morrison
- Neurobiology of Nutrition and Metabolism Department, Pennington Biomedical Research Center, Louisiana State University System, Baton Rouge, Louisiana
| | - David Burk
- Neurobiology of Nutrition and Metabolism Department, Pennington Biomedical Research Center, Louisiana State University System, Baton Rouge, Louisiana
| | - Hans Rudolf Berthoud
- Neurobiology of Nutrition and Metabolism Department, Pennington Biomedical Research Center, Louisiana State University System, Baton Rouge, Louisiana
| | - Heike Münzberg
- Neurobiology of Nutrition and Metabolism Department, Pennington Biomedical Research Center, Louisiana State University System, Baton Rouge, Louisiana
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16
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Fischer AW, Schlein C, Cannon B, Heeren J, Nedergaard J. Intact innervation is essential for diet-induced recruitment of brown adipose tissue. Am J Physiol Endocrinol Metab 2019; 316:E487-E503. [PMID: 30576247 PMCID: PMC6459298 DOI: 10.1152/ajpendo.00443.2018] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The possibility that recruitment and activation of brown adipose tissue (BAT) thermogenesis could be beneficial for curtailing obesity development in humans prompts a need for a better understanding of the control of these processes [that are often referred to collectively as diet-induced thermogenesis (DIT)]. Dietary conditions are associated with large changes in blood-borne factors that could be responsible for BAT recruitment, but BAT is also innervated by the sympathetic nervous system. To examine the significance of the innervation for DIT recruitment, we surgically denervated the largest BAT depot, i.e., the interscapular BAT depot in mice and exposed the mice at thermoneutrality to a high-fat diet versus a chow diet. Denervation led to an alteration in feeding pattern but did not lead to enhanced obesity, but obesity was achieved with a lower food intake, as denervation increased metabolic efficiency. Conclusively, denervation totally abolished the diet-induced increase in total UCP1 protein levels observed in the intact mice, whereas basal UCP1 expression was not dependent on innervation. The denervation of interscapular BAT did not discernably hyper-recruit other BAT depots, and no UCP1 protein could be detected in the principally browning-competent inguinal white adipose tissue depot under any of the examined conditions. We conclude that intact innervation is essential for diet-induced thermogenesis and that circulating factors cannot by themselves initiate recruitment of brown adipose tissue under obesogenic conditions. Therefore, the processes that link food intake and energy storage to activation of the nervous system are those of significance for the further understanding of diet-induced thermogenesis.
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Affiliation(s)
- Alexander W Fischer
- Department of Biochemistry and Molecular Cell Biology, University Medical Center Hamburg-Eppendorf , Hamburg , Germany
- Department of Molecular Biosciences, Wenner-Gren Institute, Stockholm University , Stockholm , Sweden
| | - Christian Schlein
- Department of Biochemistry and Molecular Cell Biology, University Medical Center Hamburg-Eppendorf , Hamburg , Germany
| | - Barbara Cannon
- Department of Molecular Biosciences, Wenner-Gren Institute, Stockholm University , Stockholm , Sweden
| | - Joerg Heeren
- Department of Biochemistry and Molecular Cell Biology, University Medical Center Hamburg-Eppendorf , Hamburg , Germany
| | - Jan Nedergaard
- Department of Molecular Biosciences, Wenner-Gren Institute, Stockholm University , Stockholm , Sweden
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Small molecules for fat combustion: targeting obesity. Acta Pharm Sin B 2019; 9:220-236. [PMID: 30976490 PMCID: PMC6438825 DOI: 10.1016/j.apsb.2018.09.007] [Citation(s) in RCA: 74] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2018] [Revised: 08/01/2018] [Accepted: 08/22/2018] [Indexed: 12/11/2022] Open
Abstract
Obesity is increasing in an alarming rate worldwide, which causes higher risks of some diseases, such as type 2 diabetes, cardiovascular diseases, and cancer. Current therapeutic approaches, either pancreatic lipase inhibitors or appetite suppressors, are generally of limited effectiveness. Brown adipose tissue (BAT) and beige cells dissipate fatty acids as heat to maintain body temperature, termed non-shivering thermogenesis; the activity and mass of BAT and beige cells are negatively correlated with overweight and obesity. The existence of BAT and beige cells in human adults provides an effective weight reduction therapy, a process likely to be amenable to pharmacological intervention. Herein, we combed through the physiology of thermogenesis and the role of BAT and beige cells in combating with obesity. We summarized the thermogenic regulators identified in the past decades, targeting G protein-coupled receptors, transient receptor potential channels, nuclear receptors and miscellaneous pathways. Advances in clinical trials were also presented. The main purpose of this review is to provide a comprehensive and up-to-date knowledge from the biological importance of thermogenesis in energy homeostasis to the representative thermogenic regulators for treating obesity. Thermogenic regulators might have a large potential for further investigations to be developed as lead compounds in fighting obesity.
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Key Words
- AKT, protein kinase B
- ALDH9, aldehyde dehydrogenase 9
- AMPK, AMP-activated protein kinase
- ATP, adenosine triphosphate
- BA, bile acids
- BAT, brown adipose tissue
- BMP8b, bone morphogenetic protein 8b
- Beige cells
- Brown adipose tissue
- C/EBPα, CCAAT/enhancer binding protein α
- CLA, cis-12 conjugated linoleic acid
- CRABP-II, cellular RA binding protein type II
- CRE, cAMP response element
- Cidea, cell death-inducing DNA fragmentation factor α-like effector A
- Dio2, iodothyronine deiodinase type 2
- ERE, estrogen response element
- ERs, estrogen receptors
- FAS, fatty acid synthase
- FGF21, fibroblast growth factor 21
- GPCRs, G protein-coupled receptors
- HFD, high fat diet
- LXR, liver X receptors
- MAPK, mitogen-activated protein kinase
- OXPHOS, oxidative phosphorylation
- Obesity
- PDEs, phosphodiesterases
- PET-CT, positron emission tomography combined with computed tomography
- PGC-1α, peroxisome proliferator-activated receptor γ coactivator 1-α
- PKA, protein kinase A
- PPARs, peroxisome proliferator-activated receptors
- PPREs, peroxisome proliferator response elements
- PRDM16, PR domain containing 16
- PTP1B, protein-tyrosine phosphatase 1B
- PXR, pregnane X receptor
- RA, retinoic acid
- RAR, RA receptor
- RARE, RA response element
- RMR, resting metabolic rate
- RXR, retinoid X receptor
- SIRT1, silent mating type information regulation 2 homolog 1
- SNS, sympathetic nervous system
- TFAM, mitochondrial transcription factor A
- TMEM26, transmembrane protein 26
- TRPs, transient receptor potential cation channels
- Thermogenesis
- UCP1, uncoupling protein 1
- Uncoupling protein 1
- VDR, vitamin D receptor
- VDRE, VDR response elements
- WAT, white adipose tissue
- cAMP, cyclic adenosine monophosphate
- cGMP, cyclic guanosine monophosphate
- β3-AR, β3-adrenergic receptor
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18
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Xia TL, Li YM, Huang FY, Chai H, Huang BT, Li Q, Zhao ZG, Liao YB, Zuo ZL, Peng Y, Chen M, Huang DJ. The triglyceride paradox in the mortality of coronary artery disease. Lipids Health Dis 2019; 18:21. [PMID: 30670053 PMCID: PMC6343235 DOI: 10.1186/s12944-019-0972-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2018] [Accepted: 01/08/2019] [Indexed: 02/05/2023] Open
Abstract
Background The role of triglyceride (TG) in secondary prevention of patients with coronary artery disease (CAD) was debated. In the present study, we assessed the association between admission TG levels and long-term mortality risk in CAD patients. Methods A retrospective analysis was conducted from a single registered database. 3061 consecutive patients with CAD confirmed by coronary angiography were enrolled and were grouped into 3 categories by the tertiles of admission serum TG levels. The primary end point in this study was all-cause mortality and the secondary end point was cardiovascular mortality. Results The mean follow-up time was 26.9 ± 13.6 months and death events occurred in 258 cases and cardiovascular death events occurred in 146 cases. Cumulative survival curves indicated that the risk of all-cause death decreased with increasing TG level (Tertile 1 vs. Tertile 2 vs. Tertile 3 = 10.3% vs. 8.6% vs. 6.3%, log rank test for overall p = 0.001). Cox regression analysis showed an independent correlation between TG level and risk of all-cause mortality [hazard ratio (HR) 0.71, 95% confidence interval (CI) 0.58–0.86] and cardiovascular mortality (HR 0.67, 95% CI 0.51–0.89) in total patients with CAD. Subgroup analysis found the similar results in patients with acute coronary syndrome and acute myocardial infarction. Conclusions This study found an inverse association between TG levels and mortality risk in CAD patients, which suggests that the “TG paradox” may exist in CAD patients. Trial registration ChiCTR, ChiCTR-OOC-17010433. Registered 17 February 2017 - Retrospectively registered.
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Affiliation(s)
- Tian-Li Xia
- Department of Cardiology, West China Hospital, Sichuan University, 37 Guoxue Street, Chengdu, 610041, People's Republic of China
| | - Yi-Ming Li
- West China School of Medicine, Sichuan University, Chengdu, China
| | - Fang-Yang Huang
- Department of Cardiology, West China Hospital, Sichuan University, 37 Guoxue Street, Chengdu, 610041, People's Republic of China
| | - Hua Chai
- Department of Cardiology, West China Hospital, Sichuan University, 37 Guoxue Street, Chengdu, 610041, People's Republic of China
| | - Bao-Tao Huang
- Department of Cardiology, West China Hospital, Sichuan University, 37 Guoxue Street, Chengdu, 610041, People's Republic of China
| | - Qiao Li
- Department of Cardiology, West China Hospital, Sichuan University, 37 Guoxue Street, Chengdu, 610041, People's Republic of China
| | - Zhen-Gang Zhao
- Department of Cardiology, West China Hospital, Sichuan University, 37 Guoxue Street, Chengdu, 610041, People's Republic of China
| | - Yan-Biao Liao
- Department of Cardiology, West China Hospital, Sichuan University, 37 Guoxue Street, Chengdu, 610041, People's Republic of China
| | - Zhi-Liang Zuo
- Department of Cardiology, West China Hospital, Sichuan University, 37 Guoxue Street, Chengdu, 610041, People's Republic of China
| | - Yong Peng
- Department of Cardiology, West China Hospital, Sichuan University, 37 Guoxue Street, Chengdu, 610041, People's Republic of China.
| | - Mao Chen
- Department of Cardiology, West China Hospital, Sichuan University, 37 Guoxue Street, Chengdu, 610041, People's Republic of China.
| | - De-Jia Huang
- Department of Cardiology, West China Hospital, Sichuan University, 37 Guoxue Street, Chengdu, 610041, People's Republic of China
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19
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Carnagarin R, Matthews VB, Herat LY, Ho JK, Schlaich MP. Autonomic Regulation of Glucose Homeostasis: a Specific Role for Sympathetic Nervous System Activation. Curr Diab Rep 2018; 18:107. [PMID: 30232652 DOI: 10.1007/s11892-018-1069-2] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
PURPOSE OF REVIEW Cardiometabolic disorders such as obesity, metabolic syndrome and diabetes are increasingly common and associated with adverse cardiovascular outcomes. The mechanisms driving these developments are incompletely understood but likely to include autonomic dysregulation. The latest evidence for such a role is briefly reviewed here. RECENT FINDINGS Recent findings highlight the relevance of autonomic regulation in glucose metabolism and identify sympathetic activation, in concert with parasympathetic withdrawal, as a major contributor to the development of metabolic disorders and an important mediator of the associated adverse cardiovascular consequences. Methods targeting sympathetic overactivity using pharmacological and device-based approaches are available and appear as logical additional approaches to curb the burden of metabolic disorders and alleviate the associated morbidity from cardiovascular causes. While the available data are encouraging, the role of therapeutic inhibition of sympathetic overdrive in the prevention of the metabolic disorders and the associated adverse outcomes requires adequate testing in properly sized randomised controlled trials.
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Affiliation(s)
- Revathy Carnagarin
- Dobney Hypertension Centre, School of Medicine - Royal Perth Hospital Unit / Medical Research Foundation, University of Western Australia, Level 3, MRF Building, Rear 50 Murray St, Perth, WA, 6000, Australia
| | - Vance B Matthews
- Dobney Hypertension Centre, School of Medicine - Royal Perth Hospital Unit / Medical Research Foundation, University of Western Australia, Level 3, MRF Building, Rear 50 Murray St, Perth, WA, 6000, Australia
| | - Lakshini Y Herat
- Dobney Hypertension Centre, School of Medicine - Royal Perth Hospital Unit / Medical Research Foundation, University of Western Australia, Level 3, MRF Building, Rear 50 Murray St, Perth, WA, 6000, Australia
| | - Jan K Ho
- Dobney Hypertension Centre, School of Medicine - Royal Perth Hospital Unit / Medical Research Foundation, University of Western Australia, Level 3, MRF Building, Rear 50 Murray St, Perth, WA, 6000, Australia
| | - Markus P Schlaich
- Dobney Hypertension Centre, School of Medicine - Royal Perth Hospital Unit / Medical Research Foundation, University of Western Australia, Level 3, MRF Building, Rear 50 Murray St, Perth, WA, 6000, Australia.
- Departments of Cardiology and Nephrology, Royal Perth Hospital, Perth, Australia.
- Neurovascular Hypertension & Kidney Disease Laboratory, Baker Heart and Diabetes Institute, Melbourne, Australia.
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20
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Paschoal VA, Belchior T, Amano MT, Burgos-Silva M, Peixoto AS, Magdalon J, Vieira TS, Andrade ML, Moreno MF, Chimin P, Câmara NO, Festuccia WT. Constitutive Activation of the Nutrient Sensor mTORC1 in Myeloid Cells Induced by Tsc1 Deletion Protects Mice from Diet-Induced Obesity. Mol Nutr Food Res 2018; 62:e1800283. [DOI: 10.1002/mnfr.201800283] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2018] [Revised: 06/27/2018] [Indexed: 11/11/2022]
Affiliation(s)
- Vivian A. Paschoal
- Department of Physiology and Biophysics; Institute of Biomedical Sciences; University of São Paulo; São Paulo 05508000 Brazil
| | - Thiago Belchior
- Department of Physiology and Biophysics; Institute of Biomedical Sciences; University of São Paulo; São Paulo 05508000 Brazil
| | - Mariane T. Amano
- Department of Immunology, Institute of Biomedical Sciences; University of São Paulo; São Paulo 05508000 Brazil
| | - Marina Burgos-Silva
- Department of Immunology, Institute of Biomedical Sciences; University of São Paulo; São Paulo 05508000 Brazil
| | - Albert S. Peixoto
- Department of Physiology and Biophysics; Institute of Biomedical Sciences; University of São Paulo; São Paulo 05508000 Brazil
| | - Juliana Magdalon
- Department of Physiology and Biophysics; Institute of Biomedical Sciences; University of São Paulo; São Paulo 05508000 Brazil
- Israelita Albert Einstein Hospital; São Paulo 05652-900 Brazil
| | - Thayna S. Vieira
- Department of Physiology and Biophysics; Institute of Biomedical Sciences; University of São Paulo; São Paulo 05508000 Brazil
| | - Maynara L. Andrade
- Department of Physiology and Biophysics; Institute of Biomedical Sciences; University of São Paulo; São Paulo 05508000 Brazil
| | - Mayara F. Moreno
- Department of Physiology and Biophysics; Institute of Biomedical Sciences; University of São Paulo; São Paulo 05508000 Brazil
| | - Patricia Chimin
- Department of Physical Education; Physical Education and Sports Center; Londrina State University; Londrina 86051-990 Parana Brazil
| | - Niels O. Câmara
- Department of Immunology, Institute of Biomedical Sciences; University of São Paulo; São Paulo 05508000 Brazil
| | - William T. Festuccia
- Department of Physiology and Biophysics; Institute of Biomedical Sciences; University of São Paulo; São Paulo 05508000 Brazil
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21
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Sopeña B, López-Ibarra Z, López-Farré AJ, de Las Heras N, Ballesteros S, González-Cantalapiedra A, Lahera V, Zamorano-León JJ. Really does temperature reduction and norepinephrine have similar effects on the energy metabolism in rat brown adipose tissue? Arch Physiol Biochem 2018; 124:54-60. [PMID: 28844165 DOI: 10.1080/13813455.2017.1360913] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
CONTEXT Heat generation by brown adipose tissue (BAT) in response to temperature reduction seems to be entirely related to sympathetic nervous stimulation. OBJECTIVE To analyse if temperature reduction and norepinephrine may differently affect the expression of proteins related to energy metabolism in BAT. MATERIALS AND METHODS Isolated rats BAT was incubated with/without norepinephrine (10-6 mol/L, 24 h at 32 °C and 37 °C). RESULTS In BAT, 32 °C increased the protein expression levels of carnitine palmitoyltransferase-I and -II, mitochondrial uncoupling protein-1 (UCP-1) and the expression and activity of lactate dehydrogenase. Mitochondrial F1-ATP synthase α-chain expression was decreased at 32 °C compared to 37 °C. Norepinephrine and at 32 °C exposure, UCP-1 expression was increased but cytochrome-c oxidase and F1-ATP synthase α-chain expression was reduced with respect to 37 °C. DISCUSSION Sympathetic stimulation seems not to be the only factor associated with heat generation. CONCLUSIONS Temperature reduction by itself exerts some different effects on the expression of proteins related to the energy metabolism than norepinephrine.
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Affiliation(s)
- B Sopeña
- a Department of Medicine, School of Medicine , Universidad Complutense de Madrid , Madrid , Spain
| | - Z López-Ibarra
- a Department of Medicine, School of Medicine , Universidad Complutense de Madrid , Madrid , Spain
- b Surgery Department , Hospital Universitario ROF-Codina , Lugo , Spain
| | - A J López-Farré
- a Department of Medicine, School of Medicine , Universidad Complutense de Madrid , Madrid , Spain
| | - N de Las Heras
- c Department of Physiology, School of Medicine , Universidad Complutense de Madrid , Madrid , Spain
| | - S Ballesteros
- c Department of Physiology, School of Medicine , Universidad Complutense de Madrid , Madrid , Spain
| | | | - V Lahera
- c Department of Physiology, School of Medicine , Universidad Complutense de Madrid , Madrid , Spain
| | - J J Zamorano-León
- a Department of Medicine, School of Medicine , Universidad Complutense de Madrid , Madrid , Spain
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22
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Merlin J, Sato M, Chia LY, Fahey R, Pakzad M, Nowell CJ, Summers RJ, Bengtsson T, Evans BA, Hutchinson DS. Rosiglitazone and a β 3-Adrenoceptor Agonist Are Both Required for Functional Browning of White Adipocytes in Culture. Front Endocrinol (Lausanne) 2018; 9:249. [PMID: 29910772 PMCID: PMC5992408 DOI: 10.3389/fendo.2018.00249] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/31/2018] [Accepted: 05/02/2018] [Indexed: 01/01/2023] Open
Abstract
The recruitment of brite (or beige) adipocytes has been advocated as a means to combat obesity, due to their ability to phenotypically resemble brown adipocytes (BA). Lineage studies indicate that brite adipocytes are formed by differentiation of precursor cells or by direct conversion of existing white adipocytes, depending on the adipose depot examined. We have systematically compared the gene expression profile and a functional output (oxygen consumption) in mouse adipocytes cultured from two contrasting depots, namely interscapular brown adipose tissue, and inguinal white adipose tissue (iWAT), following treatment with a known browning agent, the peroxisome proliferator-activated receptor (PPARγ) activator rosiglitazone. Prototypical BA readily express uncoupling protein (UCP)1, and upstream regulators including the β3-adrenoceptor and transcription factors involved in energy homeostasis. Adipocytes from inguinal WAT display maximal UCP1 expression and mitochondrial uncoupling only when treated with a combination of the PPARγ activator rosiglitazone and a β3-adrenoceptor agonist. In conclusion, brite adipocytes are fully activated only when a browning agent (rosiglitazone) and a thermogenic agent (β3-adrenoceptor agonist) are added in combination. The presence of rosiglitazone throughout the 7-day culture period partially masks the effects of β3-adrenoceptor signaling in inguinal white adipocyte cultures, whereas including rosiglitazone only for the first 3 days promotes robust β3-adrenoceptor expression and provides an improved window for detection of β3-adrenoceptor responses.
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Affiliation(s)
- Jon Merlin
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, Australia
| | - Masaaki Sato
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, Australia
| | - Ling Yeong Chia
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, Australia
| | - Richard Fahey
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, Australia
| | - Mohsen Pakzad
- Department of Toxicology and Pharmacology, Faculty of Pharmacy, Pharmaceutical Sciences Research Center, Tehran University of Medical Sciences, Tehran, Iran
| | - Cameron J. Nowell
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, Australia
| | - Roger J. Summers
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, Australia
| | - Tore Bengtsson
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
| | - Bronwyn A. Evans
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, Australia
| | - Dana S. Hutchinson
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, Australia
- Department of Pharmacology, Monash University, Clayton, VIC, Australia
- *Correspondence: Dana S. Hutchinson,
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23
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Loh RKC, Formosa MF, Eikelis N, Bertovic DA, Anderson MJ, Barwood SA, Nanayakkara S, Cohen ND, La Gerche A, Reutens AT, Yap KS, Barber TW, Lambert GW, Cherk MH, Duffy SJ, Kingwell BA, Carey AL. Pioglitazone reduces cold-induced brown fat glucose uptake despite induction of browning in cultured human adipocytes: a randomised, controlled trial in humans. Diabetologia 2018; 61:220-230. [PMID: 29046921 DOI: 10.1007/s00125-017-4479-9] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/21/2017] [Accepted: 09/21/2017] [Indexed: 12/16/2022]
Abstract
AIMS/HYPOTHESIS Increasing brown adipose tissue (BAT) activity is a possible therapeutic strategy to increase energy expenditure and glucose and lipid clearance to ameliorate obesity and associated comorbidities. The thiazolidinedione (TZD) class of glucose-lowering drugs increase BAT browning in preclinical experimental models but whether these actions extend to humans in vivo is unknown. The aim of this study was to determine the effect of pioglitazone treatment on adipocyte browning and adaptive thermogenesis in humans. METHODS We first examined whether pioglitazone treatment of cultured human primary subacromioclavicular-derived adipocytes induced browning. Then, in a blinded, placebo-controlled, parallel trial, conducted within the Baker Institute clinical research laboratories, 14 lean male participants who were free of cardiometabolic disease were randomised to receive either placebo (lactose; n = 7, age 22 ± 1 years) or pioglitazone (45 mg/day, n = 7, age 21 ± 1 years) for 28 days. Participants were allocated to treatments by Alfred Hospital staff independent from the study via electronic generation of a random number sequence. Researchers conducting trials and analysing data were blind to treatment allocation. The change in cold-stimulated BAT activity, assessed before and after the intervention by [18F]fluorodeoxyglucose uptake via positron emission tomography/computed tomography in upper thoracic and cervical adipose tissue, was the primary outcome measure. Energy expenditure, cardiovascular responses, core temperature, blood metabolites and hormones were measured in response to acute cold exposure along with body composition before and after the intervention. RESULTS Pioglitazone significantly increased in vitro browning and adipogenesis of adipocytes. In the clinical trial, cold-induced BAT maximum standardised uptake value was significantly reduced after pioglitazone compared with placebo (-57 ± 6% vs -12 ± 18%, respectively; p < 0.05). BAT total glucose uptake followed a similar but non-significant trend (-50 ± 10% vs -6 ± 24%, respectively; p = 0.097). Pioglitazone increased total and lean body mass compared with placebo (p < 0.05). No other changes between groups were detected. CONCLUSIONS/INTERPRETATION The disparity in the actions of pioglitazone on BAT between preclinical experimental models and our in vivo human trial highlight the imperative to conduct human proof-of-concept studies as early as possible in BAT research programmes aimed at therapeutic development. Our clinical trial findings suggest that reduced BAT activity may contribute to weight gain associated with pioglitazone and other TZDs. TRIAL REGISTRATION ClinicalTrials.gov NCT02236962 FUNDING: This work was supported by the Diabetes Australia Research Program and OIS scheme from the Victorian State Government.
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Affiliation(s)
- Rebecca K C Loh
- Metabolic and Vascular Physiology Laboratory, Baker Heart and Diabetes Institute, P. O. Box 6492, Melbourne, VIC, 3004, Australia
| | - Melissa F Formosa
- Metabolic and Vascular Physiology Laboratory, Baker Heart and Diabetes Institute, P. O. Box 6492, Melbourne, VIC, 3004, Australia
| | - Nina Eikelis
- Human Neurotransmitters Laboratory, Baker Heart and Diabetes Institute, Melbourne, VIC, Australia
- Iverson Health Innovation Research Institute, Swinburne Institute of Technology, Melbourne, VIC, Australia
| | - David A Bertovic
- Metabolic and Vascular Physiology Laboratory, Baker Heart and Diabetes Institute, P. O. Box 6492, Melbourne, VIC, 3004, Australia
| | - Mitchell J Anderson
- Metabolic and Vascular Physiology Laboratory, Baker Heart and Diabetes Institute, P. O. Box 6492, Melbourne, VIC, 3004, Australia
- Melbourne Orthopaedic Group, Windsor, VIC, Australia
| | | | - Shane Nanayakkara
- Department of Cardiovascular Medicine, Alfred Hospital, Melbourne, VIC, Australia
| | - Neale D Cohen
- Baker Heart and Diabetes Institute, Melbourne, VIC, Australia
| | - Andre La Gerche
- Sports Cardiology Laboratory, Baker Heart and Diabetes Institute, Melbourne, VIC, Australia
| | - Anne T Reutens
- Baker Heart and Diabetes Institute, Melbourne, VIC, Australia
| | - Kenneth S Yap
- The Department of Nuclear Medicine and PET, Alfred Health, Melbourne, VIC, Australia
- Department of Medicine, Monash University, Alfred Hospital Campus, Melbourne, VIC, Australia
| | - Thomas W Barber
- The Department of Nuclear Medicine and PET, Alfred Health, Melbourne, VIC, Australia
- Department of Medicine, Monash University, Alfred Hospital Campus, Melbourne, VIC, Australia
| | - Gavin W Lambert
- Human Neurotransmitters Laboratory, Baker Heart and Diabetes Institute, Melbourne, VIC, Australia
- Iverson Health Innovation Research Institute, Swinburne Institute of Technology, Melbourne, VIC, Australia
| | - Martin H Cherk
- The Department of Nuclear Medicine and PET, Alfred Health, Melbourne, VIC, Australia
- Department of Medicine, Monash University, Alfred Hospital Campus, Melbourne, VIC, Australia
| | - Stephen J Duffy
- Department of Cardiovascular Medicine, Alfred Hospital, Melbourne, VIC, Australia
| | - Bronwyn A Kingwell
- Metabolic and Vascular Physiology Laboratory, Baker Heart and Diabetes Institute, P. O. Box 6492, Melbourne, VIC, 3004, Australia.
| | - Andrew L Carey
- Metabolic and Vascular Physiology Laboratory, Baker Heart and Diabetes Institute, P. O. Box 6492, Melbourne, VIC, 3004, Australia.
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A novel peptide that improves metabolic parameters without adverse central nervous system effects. Sci Rep 2017; 7:14781. [PMID: 29093454 PMCID: PMC5665932 DOI: 10.1038/s41598-017-13690-9] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2017] [Accepted: 09/29/2017] [Indexed: 01/22/2023] Open
Abstract
Intracellular peptides generated by limited proteolysis are likely to function inside and outside cells and could represent new possibilities for drug development. Here, we used several conformational-sensitive antibodies targeting G-protein coupled receptors to screen for novel pharmacological active peptides. We find that one of these peptides, DITADDEPLT activates cannabinoid type 1 receptors. Single amino acid modifications identified a novel peptide, DIIADDEPLT (Pep19), with slightly better inverse agonist activity at cannabinoid type 1 receptors. Pep19 induced uncoupling protein 1 expression in both white adipose tissue and 3T3-L1 differentiated adipocytes; in the latter, Pep19 activates pERK1/2 and AKT signaling pathways. Uncoupling protein 1 expression induced by Pep19 in 3T3-L1 differentiated adipocytes is blocked by AM251, a cannabinoid type 1 receptors antagonist. Oral administration of Pep19 into diet-induced obese Wistar rats significantly reduces adiposity index, whole body weight, glucose, triacylglycerol, cholesterol and blood pressure, without altering heart rate; changes in the number and size of adipocytes were also observed. Pep19 has no central nervous system effects as suggested by the lack of brain c-Fos expression, cell toxicity, induction of the cannabinoid tetrad, depressive- and anxiety-like behaviors. Therefore, Pep19 has several advantages over previously identified peripherally active cannabinoid compounds, and could have clinical applications.
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25
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Castro É, Silva TEO, Festuccia WT. Critical review of beige adipocyte thermogenic activation and contribution to whole-body energy expenditure. Horm Mol Biol Clin Investig 2017; 31:/j/hmbci.ahead-of-print/hmbci-2017-0042/hmbci-2017-0042.xml. [PMID: 28862985 DOI: 10.1515/hmbci-2017-0042] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2017] [Accepted: 07/17/2017] [Indexed: 12/30/2022]
Abstract
Beige (or brite, "brown in white") adipocytes are uncoupling protein 1 (UCP1)-positive cells residing in white adipose depots that, depending on the conditions, behave either as classic white adipocytes, storing energy as lipids, or as brown adipocytes, dissipating energy from oxidative metabolism as heat through non-shivering thermogenesis. Because of their thermogenic potential and, therefore, possible usage to treat metabolic diseases such as obesity and type 2 diabetes, beige cells have attracted the attention of many scientists worldwide aiming to develop strategies to safely recruit and activate their thermogenic activity. Indeed, in recent years, a large variety of conditions, molecules (including nutrients) and signaling pathways were reported to promote the recruitment of beige adipocytes. Despite of those advances, the true contribution of beige adipocyte thermogenesis to whole-body energy expenditure is still not completely defined. Herein, we discuss some important aspects that should be considered when studying beige adipocyte biology and the contribution to energy balance and whole-body metabolism.
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26
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Weiner J, Rohde K, Krause K, Zieger K, Klöting N, Kralisch S, Kovacs P, Stumvoll M, Blüher M, Böttcher Y, Heiker JT. Brown adipose tissue (BAT) specific vaspin expression is increased after obesogenic diets and cold exposure and linked to acute changes in DNA-methylation. Mol Metab 2017; 6:482-493. [PMID: 28580279 PMCID: PMC5444018 DOI: 10.1016/j.molmet.2017.03.004] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/21/2017] [Revised: 03/10/2017] [Accepted: 03/15/2017] [Indexed: 02/07/2023] Open
Abstract
OBJECTIVE Several studies have demonstrated anti-diabetic and anti-obesogenic properties of visceral adipose tissue-derived serine protease inhibitor (vaspin) and so evoked its potential use for treatment of obesity-related diseases. The aim of the study was to unravel physiological regulators of vaspin expression and secretion with a particular focus on its role in brown adipose tissue (BAT) biology. METHODS We analyzed the effects of obesogenic diets and cold exposure on vaspin expression in liver and white and brown adipose tissue (AT) and plasma levels. Vaspin expression was analyzed in isolated white and brown adipocytes during adipogenesis and in response to adrenergic stimuli. DNA-methylation within the vaspin promoter was analyzed to investigate acute epigenetic changes after cold-exposure in BAT. RESULTS Our results demonstrate a strong induction of vaspin mRNA and protein expression specifically in BAT of both cold-exposed and high-fat (HF) or high-sugar (HS) fed mice. While obesogenic diets also upregulated hepatic vaspin mRNA levels, cold exposure tended to increase vaspin gene expression of inguinal white adipose tissue (iWAT) depots. Concomitantly, vaspin plasma levels were decreased upon obesogenic or thermogenic triggers. Vaspin expression was increased during adipogenesis but unaffected by sympathetic activation in brown adipocytes. Analysis of vaspin promoter methylation in AT revealed lowest methylation levels in BAT, which were acutely reduced after cold exposure. CONCLUSIONS Our data demonstrate a novel BAT-specific regulation of vaspin gene expression upon physiological stimuli in vivo with acute epigenetic changes that may contribute to cold-induced expression in BAT. We conclude that these findings indicate functional relevance and potentially beneficial effects of vaspin in BAT function.
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Affiliation(s)
- Juliane Weiner
- Divisions of Endocrinology and Nephrology, University of Leipzig, Leipzig, Germany
- Institute of Biochemistry, Faculty of Biosciences, Pharmacy and Psychology, University of Leipzig, Leipzig, Germany
| | - Kerstin Rohde
- Leipzig University Medical Center, IFB Adiposity Diseases, University of Leipzig, Leipzig, Germany
- Department of Clinical Molecular Biology, University of Oslo, Oslo, Norway
| | - Kerstin Krause
- Divisions of Endocrinology and Nephrology, University of Leipzig, Leipzig, Germany
| | - Konstanze Zieger
- Institute of Biochemistry, Faculty of Biosciences, Pharmacy and Psychology, University of Leipzig, Leipzig, Germany
| | - Nora Klöting
- Divisions of Endocrinology and Nephrology, University of Leipzig, Leipzig, Germany
- Leipzig University Medical Center, IFB Adiposity Diseases, University of Leipzig, Leipzig, Germany
| | - Susan Kralisch
- Divisions of Endocrinology and Nephrology, University of Leipzig, Leipzig, Germany
- Leipzig University Medical Center, IFB Adiposity Diseases, University of Leipzig, Leipzig, Germany
| | - Peter Kovacs
- Leipzig University Medical Center, IFB Adiposity Diseases, University of Leipzig, Leipzig, Germany
| | - Michael Stumvoll
- Divisions of Endocrinology and Nephrology, University of Leipzig, Leipzig, Germany
| | - Matthias Blüher
- Divisions of Endocrinology and Nephrology, University of Leipzig, Leipzig, Germany
- Leipzig University Medical Center, IFB Adiposity Diseases, University of Leipzig, Leipzig, Germany
| | - Yvonne Böttcher
- Leipzig University Medical Center, IFB Adiposity Diseases, University of Leipzig, Leipzig, Germany
- Department of Clinical Molecular Biology, University of Oslo, Oslo, Norway
| | - John T. Heiker
- Divisions of Endocrinology and Nephrology, University of Leipzig, Leipzig, Germany
- Institute of Biochemistry, Faculty of Biosciences, Pharmacy and Psychology, University of Leipzig, Leipzig, Germany
- Leipzig University Medical Center, IFB Adiposity Diseases, University of Leipzig, Leipzig, Germany
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27
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Paschoal VA, Amano MT, Belchior T, Magdalon J, Chimin P, Andrade ML, Ortiz-Silva M, Castro É, Yamashita AS, Rosa Neto JC, Câmara NO, Festuccia WT. mTORC1 inhibition with rapamycin exacerbates adipose tissue inflammation in obese mice and dissociates macrophage phenotype from function. Immunobiology 2016; 222:261-271. [PMID: 27692982 DOI: 10.1016/j.imbio.2016.09.014] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2016] [Revised: 07/08/2016] [Accepted: 09/26/2016] [Indexed: 10/20/2022]
Abstract
Genetic- and diet-induced obesity and insulin resistance are associated with an increase in mechanistic target of rapamycin complex (mTORC) 1 activity in adipose tissue. We investigated herein the effects of pharmacological mTORC1 inhibition in the development of adipose tissue inflammation induced by high-fat diet (HFD) feeding, as well as in the polarization, metabolism and function of bone marrow-derived macrophages (BMDM). For this, C57BL/6J mice fed with a standard chow diet or a HFD (60% of calories from fat) and treated with either vehicle (0.1% Me2SO, 0.2% methylcellulose) or rapamycin (2mg/kg/ day, gavage) during 30days were evaluated for body weight, adiposity, glucose tolerance and adipose tissue inflammation. Although rapamycin did not affect the increase in body weight and adiposity, it exacerbated the glucose intolerance and adipose tissue inflammation induced by HFD feeding, as evidenced by the increased adipose tissue percentage of M1 macrophages, naive and activated cytotoxic T lymphocytes, and mRNA levels of proinflammatory molecules, such as TNF-α, IL-6 and MCP-1. In BMDM in vitro, pharmacological mTORC1 inhibition induced phosphorylation of NFκB p65 and spontaneous polarization of macrophages to a proinflammatory M1 profile, while it impaired M2 polarization induced by IL-4+IL-13, glycolysis and phagocytosis. Altogether, these findings indicate that mTORC1 activity is an important determinant of adipose tissue inflammatory profile and macrophage plasticity, metabolism and function.
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Affiliation(s)
- Vivian A Paschoal
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo 05508000, Brazil
| | - Mariane T Amano
- Department of Immunology, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo 05508000, Brazil
| | - Thiago Belchior
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo 05508000, Brazil
| | - Juliana Magdalon
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo 05508000, Brazil
| | - Patricia Chimin
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo 05508000, Brazil
| | - Maynara L Andrade
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo 05508000, Brazil
| | - Milene Ortiz-Silva
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo 05508000, Brazil
| | - Érique Castro
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo 05508000, Brazil
| | - Alex S Yamashita
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo 05508000, Brazil
| | - José Cesar Rosa Neto
- Department of Cell Biology and Development, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo 05508000, Brazil
| | - Niels O Câmara
- Department of Immunology, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo 05508000, Brazil
| | - William T Festuccia
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo 05508000, Brazil.
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28
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Vandal M, White PJ, Tournissac M, Tremblay C, St-Amour I, Drouin-Ouellet J, Bousquet M, Traversy MT, Planel E, Marette A, Calon F. Impaired thermoregulation and beneficial effects of thermoneutrality in the 3×Tg-AD model of Alzheimer's disease. Neurobiol Aging 2016; 43:47-57. [PMID: 27255814 DOI: 10.1016/j.neurobiolaging.2016.03.024] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2015] [Revised: 03/21/2016] [Accepted: 03/22/2016] [Indexed: 10/22/2022]
Abstract
The sharp rise in the incidence of Alzheimer's disease (AD) at an old age coincides with a reduction in energy metabolism and core body temperature. We found that the triple-transgenic mouse model of AD (3×Tg-AD) spontaneously develops a lower basal body temperature and is more vulnerable to a cold environment compared with age-matched controls. This was despite higher nonshivering thermogenic activity, as evidenced by brown adipose tissue norepinephrine content and uncoupling protein 1 expression. A 24-hour exposure to cold (4 °C) aggravated key neuropathologic markers of AD such as: tau phosphorylation, soluble amyloid beta concentrations, and synaptic protein loss in the cortex of 3×Tg-AD mice. Strikingly, raising the body temperature of aged 3×Tg-AD mice via exposure to a thermoneutral environment improved memory function and reduced amyloid and synaptic pathologies within a week. Our results suggest the presence of a vicious cycle between impaired thermoregulation and AD-like neuropathology, and it is proposed that correcting thermoregulatory deficits might be therapeutic in AD.
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Affiliation(s)
- Milene Vandal
- Faculté de pharmacie, Université Laval, Québec, Québec, Canada; Axe Neurosciences, Centre de recherche du CHU-Q (Pavillon CHUL), Québec, Québec, Canada; Institut sur la nutrition et les aliments fonctionnels, Université Laval, Québec, Québec, Canada
| | - Philip J White
- Sarah W. Stedman Nutrition and Metabolism Center and Duke Molecular Physiology Institute, Duke University Medical Center, NC, USA; Faculté de medicine, Université Laval, Québec, Québec, Canada; Institut universitaire de pneumologie et de cardiologie de Québec, Québec, Québec, Canada
| | - Marine Tournissac
- Faculté de pharmacie, Université Laval, Québec, Québec, Canada; Axe Neurosciences, Centre de recherche du CHU-Q (Pavillon CHUL), Québec, Québec, Canada; Institut sur la nutrition et les aliments fonctionnels, Université Laval, Québec, Québec, Canada
| | - Cyntia Tremblay
- Axe Neurosciences, Centre de recherche du CHU-Q (Pavillon CHUL), Québec, Québec, Canada
| | - Isabelle St-Amour
- Faculté de pharmacie, Université Laval, Québec, Québec, Canada; Axe Neurosciences, Centre de recherche du CHU-Q (Pavillon CHUL), Québec, Québec, Canada; Département de Recherche et Développement, Héma-Québec, Québec, Québec, Canada
| | - Janelle Drouin-Ouellet
- Faculté de medicine, Université Laval, Québec, Québec, Canada; John van Geest Centre for Brain Repair, University of Cambridge, Cambridge, UK
| | - Melanie Bousquet
- Faculté de pharmacie, Université Laval, Québec, Québec, Canada; Axe Neurosciences, Centre de recherche du CHU-Q (Pavillon CHUL), Québec, Québec, Canada; Institut sur la nutrition et les aliments fonctionnels, Université Laval, Québec, Québec, Canada
| | - Marie-Thérèse Traversy
- Faculté de pharmacie, Université Laval, Québec, Québec, Canada; Axe Neurosciences, Centre de recherche du CHU-Q (Pavillon CHUL), Québec, Québec, Canada
| | - Emmanuel Planel
- Axe Neurosciences, Centre de recherche du CHU-Q (Pavillon CHUL), Québec, Québec, Canada; Faculté de medicine, Université Laval, Québec, Québec, Canada
| | - Andre Marette
- Institut sur la nutrition et les aliments fonctionnels, Université Laval, Québec, Québec, Canada; Faculté de medicine, Université Laval, Québec, Québec, Canada; Institut universitaire de pneumologie et de cardiologie de Québec, Québec, Québec, Canada
| | - Frederic Calon
- Faculté de pharmacie, Université Laval, Québec, Québec, Canada; Axe Neurosciences, Centre de recherche du CHU-Q (Pavillon CHUL), Québec, Québec, Canada; Institut sur la nutrition et les aliments fonctionnels, Université Laval, Québec, Québec, Canada.
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29
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Magdalon J, Chimin P, Belchior T, Neves RX, Vieira-Lara MA, Andrade ML, Farias TS, Bolsoni-Lopes A, Paschoal VA, Yamashita AS, Kowaltowski AJ, Festuccia WT. Constitutive adipocyte mTORC1 activation enhances mitochondrial activity and reduces visceral adiposity in mice. Biochim Biophys Acta Mol Cell Biol Lipids 2016; 1861:430-8. [PMID: 26923434 DOI: 10.1016/j.bbalip.2016.02.023] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2015] [Revised: 01/26/2016] [Accepted: 02/24/2016] [Indexed: 10/22/2022]
Abstract
Mechanistic target of rapamycin complex 1 (mTORC1) loss of function reduces adiposity whereas partial mTORC1 inhibition enhances fat deposition. Herein we evaluated how constitutive mTORC1 activation in adipocytes modulates adiposity in vivo. Mice with constitutive mTORC1 activation in adipocytes induced by tuberous sclerosis complex (Tsc)1 deletion and littermate controls were evaluated for body mass, energy expenditure, glucose and fatty acid metabolism, mitochondrial function, mRNA and protein contents. Adipocyte-specific Tsc1 deletion reduced visceral, but not subcutaneous, fat mass, as well as adipocyte number and diameter, phenotypes that were associated with increased lipolysis, UCP-1 content (browning) and mRNA levels of pro-browning transcriptional factors C/EBPβ and ERRα. Adipocyte Tsc1 deletion enhanced mitochondrial oxidative activity, fatty acid oxidation and the expression of PGC-1α and PPARα in both visceral and subcutaneous fat. In brown adipocytes, however, Tsc1 deletion did not affect UCP-1 content and basal respiration. Adipocyte Tsc1 deletion also reduced visceral adiposity and enhanced glucose tolerance, liver and muscle insulin signaling and adiponectin secretion in mice fed with purified low- or high-fat diet. In conclusion, adipocyte-specific Tsc1 deletion enhances mitochondrial activity, induces browning and reduces visceral adiposity in mice.
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Affiliation(s)
- Juliana Magdalon
- Departmento de Fisiologia e Biofísica, Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo 05508000, Brazil
| | - Patricia Chimin
- Departmento de Fisiologia e Biofísica, Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo 05508000, Brazil
| | - Thiago Belchior
- Departmento de Fisiologia e Biofísica, Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo 05508000, Brazil
| | - Rodrigo X Neves
- Departmento de Biologia Celular e do Desenvolvimento, Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo 05508000, Brazil
| | - Marcel A Vieira-Lara
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo 05500900, Brazil
| | - Maynara L Andrade
- Departmento de Fisiologia e Biofísica, Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo 05508000, Brazil
| | - Talita S Farias
- Departmento de Fisiologia e Biofísica, Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo 05508000, Brazil
| | - Andressa Bolsoni-Lopes
- Departmento de Fisiologia e Biofísica, Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo 05508000, Brazil
| | - Vivian A Paschoal
- Departmento de Fisiologia e Biofísica, Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo 05508000, Brazil
| | - Alex S Yamashita
- Departmento de Fisiologia e Biofísica, Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo 05508000, Brazil
| | - Alicia J Kowaltowski
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo 05500900, Brazil
| | - William T Festuccia
- Departmento de Fisiologia e Biofísica, Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo 05508000, Brazil.
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30
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Synthetic optimization of rosiglitazone and related intermediates for industrial purposes. RESEARCH ON CHEMICAL INTERMEDIATES 2015. [DOI: 10.1007/s11164-015-2132-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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31
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Lipid Paradox in Acute Myocardial Infarction—The Association With 30-Day In-Hospital Mortality. Crit Care Med 2015; 43:1255-64. [DOI: 10.1097/ccm.0000000000000946] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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32
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Hwang JJ, Yeckel CW, Gallezot JD, Aguiar RBD, Ersahin D, Gao H, Kapinos M, Nabulsi N, Huang Y, Cheng D, Carson RE, Sherwin R, Ding YS. Imaging human brown adipose tissue under room temperature conditions with (11)C-MRB, a selective norepinephrine transporter PET ligand. Metabolism 2015; 64:747-55. [PMID: 25798999 PMCID: PMC4408242 DOI: 10.1016/j.metabol.2015.03.001] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/13/2015] [Revised: 02/11/2015] [Accepted: 03/03/2015] [Indexed: 01/20/2023]
Abstract
INTRODUCTION Brown adipose tissue (BAT) plays a critical role in adaptive thermogenesis and is tightly regulated by the sympathetic nervous system (SNS). However, current BAT imaging modalities require cold stimulation and are often unreliable to detect BAT in the basal state, at room temperature (RT). We have shown previously that BAT can be detected in rodents under both RT and cold conditions with (11)C-MRB ((S,S)-(11)C-O-methylreboxetine), a highly selective ligand for the norepinephrine transporter (NET). Here, we evaluate this novel approach for BAT detection in adult humans under RT conditions. METHODS Ten healthy, Caucasian subjects (5 M: age 24.6±2.6, BMI 21.6±2.7kg/m(2); 5 F: age 25.4±2.1, BMI 22.1±1.0kg/m(2)) underwent (11)C-MRB PET-CT imaging for cervical/supraclavicular BAT under RT and cold-stimulated conditions (RPCM Cool vest; enthalpy 15°C) compared to (18)F-FDG PET-CT imaging. Uptake of (11)C-MRB, was quantified as the distribution volume ratio (DVR) using the occipital cortex as a low NET density reference region. Total body fat and lean body mass were assessed via bioelectrical impedance analysis. RESULTS As expected, (18)F-FDG uptake in BAT was difficult to identify at RT but easily detected with cold stimulation (p=0.01). In contrast, BAT (11)C-MRB uptake (also normalized for muscle) was equally evident under both RT and cold conditions (BAT DVR: RT 1.0±0.3 vs. cold 1.1±0.3, p=0.31; BAT/muscle DVR: RT 2.3±0.7 vs. cold 2.5±0.5, p=0.61). Importantly, BAT DVR and BAT/muscle DVR of (11)C-MRB at RT correlated positively with core body temperature (r=0.76, p=0.05 and r=0.92, p=0.004, respectively), a relationship not observed with (18)F-FDG (p=0.63). Furthermore, there were gender differences in (11)C-MRB uptake in response to cold (p=0.03), which reflected significant differences in the change in (11)C-MRB as a function of both body composition and body temperature. CONCLUSIONS Unlike (18)F-FDG, the uptake of (11)C-MRB in BAT offers a unique opportunity to investigate the role of BAT in humans under basal, room temperature conditions.
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Affiliation(s)
- Janice J Hwang
- Division of Endocrinology, Yale University School of Medicine
| | | | | | | | - Devrim Ersahin
- Department of Radiology, Yale PET Center, Yale University School of Medicine
| | - Hong Gao
- Department of Radiology, Yale PET Center, Yale University School of Medicine
| | - Michael Kapinos
- Department of Radiology, Yale PET Center, Yale University School of Medicine
| | - Nabeel Nabulsi
- Department of Radiology, Yale PET Center, Yale University School of Medicine
| | - Yiyun Huang
- Department of Radiology, Yale PET Center, Yale University School of Medicine
| | - David Cheng
- Department of Radiology, Yale PET Center, Yale University School of Medicine
| | - Richard E Carson
- Department of Radiology, Yale PET Center, Yale University School of Medicine
| | - Robert Sherwin
- Division of Endocrinology, Yale University School of Medicine
| | - Yu-Shin Ding
- Departments of Radiology and Psychiatry, New York University School of Medicine.
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Bolsoni-Lopes A, Deshaies Y, Festuccia WT. Regulation of brown adipose tissue recruitment, metabolism and thermogenic function by peroxisome proliferator-activated receptor γ. Temperature (Austin) 2015; 2:476-82. [PMID: 27227067 PMCID: PMC4843924 DOI: 10.1080/23328940.2015.1011564] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2014] [Revised: 01/19/2015] [Accepted: 01/21/2015] [Indexed: 11/13/2022] Open
Abstract
Brown adipose tissue contributes importantly to homeothermy and energy balance in rodents due its ability under demand to produce heat through a process denominated nonshivering thermogenesis. Such thermogenic ability of brown adipocytes relies on the activity of mitochondrial uncoupling protein 1 that, when properly activated, dissipates energy from oxidative metabolism as heat. Brown adipose tissue sympathetic innervation through norepinephrine release not only induces brown adipocyte lipolysis and thermogenesis, but also acts as the major determinant of tissue mass, cellularity and mitochondrial content. Several pieces of evidence gathered over the years indicate that, in addition to tissue sympathetic innervation, the nuclear receptor peroxisome proliferator-activated receptor γ plays an important role in regulating the development, metabolism and thermogenic function of brown adipose tissue. Herein we review the main evidence supporting such key role of peroxisome proliferator-activated receptor γ to brown fat biology and discuss the future directions of this important area of research.
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Affiliation(s)
- Andressa Bolsoni-Lopes
- Department of Physiology and Biophysics; Institute of Biomedical Sciences; University of São Paulo ; São Paulo, SP Brazil
| | - Yves Deshaies
- Department of Medicine; Faculty of Medicine; and Québec Heart and Lung Institute; Université Laval ; Québec, Canada
| | - William T Festuccia
- Department of Physiology and Biophysics; Institute of Biomedical Sciences; University of São Paulo ; São Paulo, SP Brazil
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Intermittent cold exposure results in visceral adipose tissue "browning" in the plateau pika (Ochotona curzoniae). Comp Biochem Physiol A Mol Integr Physiol 2015; 184:171-8. [PMID: 25662677 DOI: 10.1016/j.cbpa.2015.01.019] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2014] [Revised: 01/13/2015] [Accepted: 01/25/2015] [Indexed: 01/30/2023]
Abstract
The plateau pika has developed tolerance to cold and hypoxia in order to adapt to living in the extreme environment of the Qinghai-Tibetan Plateau. One mammalian mechanism for cold adaptation is thermogenesis by brown adipose tissue (BAT), but the degree to which pika exploits this mechanism or how it may be modified by the additional stresses of high altitude is not known. Intermittent Cold Exposure (ICE) is an approachable method to study cold adaptation in rodents. To investigate the role of adipose tissue in the adaptation of pika to cold temperatures, we have studied pika during ICE. We find that pika kept in warm temperatures has little classical brown fat, but "browning" of white adipose tissues is observed rapidly upon cold exposure. This is demonstrated by the increased expression of several markers of brown fat differentiation including uncoupling protein 1 (UCP-1). Surprisingly, this occurs mainly in visceral rather than epididymal adipose tissue. In addition, ICE increases the expression of several general adipose differentiation markers at both the mRNA and protein levels. These substantial changes in the distribution of fat are accomplished without changes in weight or blood levels of glucose and triglycerides, suggesting that the adaptable changes are coordinated and self-compensated. Together, our results demonstrate that ICE promotes recruitment of BAT in pika, and unlike small mammals in at lower altitudes, pika can activate visceral WAT to adapt to cold stress without major changes overall energy balance.
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Mice fed fish oil diet and upregulation of brown adipose tissue thermogenic markers. Eur J Nutr 2015; 55:159-69. [PMID: 25612928 DOI: 10.1007/s00394-015-0834-0] [Citation(s) in RCA: 78] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2014] [Accepted: 01/08/2015] [Indexed: 12/31/2022]
Abstract
PURPOSE Fish oil (FO) elicits diverse beneficial effects. Reduction in or prevention of body mass (BM) gain in animal models may be associated with modulation of brown adipose tissue (BAT). We aimed to evaluate the effects of different high-fat diets with FO on BAT metabolism and thermogenic markers. METHODS C57BL/6 male mice (3-month-old) were fed different diets during 8 weeks: standard-chow diet (SC 10% fat), high-fat lard diet (HF-L 50% fat), high-fat lard plus FO diet (HF-L+FO 50% fat), and high-fat FO diet (HF-FO 50% fat). We evaluated BM and performed an oral glucose tolerance test. At euthanasia, plasma was collected for leptin, and triacylglycerol measurement and interscapular BAT was dissected and stored for molecular analyses. RESULTS HF-L group showed elevated BM; glucose intolerance associated with diminished TC10 and GLUT4 expressions; hypertriglyceridemia associated with increased CD36 and diminished CPT1 expression; elevated expression of pro-inflammatory cytokines; and reduced PPAR expression. Furthermore, these animals showed hyperleptinemia with increased expression of thermogenic markers (beta3-AR, PGC1alpha, and UCP1). Conversely, HF-L+FO and HF-FO groups showed reduced BM gain with regularization of glucose tolerance and triglyceridemia, GLUT4, TC10, CD36, CPT1, and cytokines expressions. Both groups exhibited elevated PPAR and thermogenic markers expression in a dose-dependent way. CONCLUSIONS FO improves metabolic profile and upregulates thermogenic markers, suggesting an elevated thermogenesis that leads to reduced BM gain.
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Wu Y, Tu Q, Valverde P, Zhang J, Murray D, Dong LQ, Cheng J, Jiang H, Rios M, Morgan E, Tang Z, Chen J. Central adiponectin administration reveals new regulatory mechanisms of bone metabolism in mice. Am J Physiol Endocrinol Metab 2014; 306:E1418-30. [PMID: 24780611 PMCID: PMC4059988 DOI: 10.1152/ajpendo.00048.2014] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Adiponectin (APN), the most abundant adipocyte-secreted adipokine, regulates energy homeostasis and exerts well-characterized insulin-sensitizing properties. The peripheral or central effects of APN regulating bone metabolism are beginning to be explored but are still not clearly understood. In the present study, we found that APN-knockout (APN-KO) mice fed a normal diet exhibited decreased trabecular structure and mineralization and increased bone marrow adiposity compared with wild-type (WT) mice. APN intracerebroventricular infusions decreased uncoupling protein 1 (UCP1) expression in brown adipose tissue, epinephrine and norepinephrine serum levels, and osteoclast numbers, whereas osteoblast osteogenic marker expression and trabecular bone mass increased in APN-KO and WT mice. In addition, centrally administered APN increased hypothalamic tryptophan hydroxylase 2 (TPH2), cocaine- and amphetamine-regulated transcript (CART), and 5-hydroxytryptamine (serotonin) receptor 2C (Htr2C) expressions but decreased hypothalamic cannabinoid receptor-1 expression. Treatment of immortalized mouse neurons with APN demonstrated that APN-mediated effects on TPH2, CART, and Htr2C expression levels were abolished by downregulating adaptor protein containing pleckstrin homology domain, phosphotyrosine domain, and leucine zipper motif (APPL)-1 expression. Pharmacological increase in sympathetic activity stimulated adipogenic differentiation of bone marrow stromal cells (BMSC) and reversed APN-induced expression of the lysine-specific demethylases involved in regulating their commitment to the osteoblastic lineage. In conclusion, we found that APN regulates bone metabolism via central and peripheral mechanisms to decrease sympathetic tone, inhibit osteoclastic differentiation, and promote osteoblastic commitment of BMSC.
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Affiliation(s)
- Yuwei Wu
- Division of Oral Biology, Tufts University School of Dental Medicine, Boston, Massachusetts; National Engineering Laboratory for Digital and Material Technology of Stomatology, Peking University School and Hospital of Stomatology, Beijing, China; Second Dental Center, Peking University School and Hospital of Stomatology, Beijing, China
| | - Qisheng Tu
- Division of Oral Biology, Tufts University School of Dental Medicine, Boston, Massachusetts
| | - Paloma Valverde
- Department of Sciences, Wentworth Institute of Technology, Boston, Massachusetts
| | - Jin Zhang
- Division of Oral Biology, Tufts University School of Dental Medicine, Boston, Massachusetts
| | - Dana Murray
- Division of Oral Biology, Tufts University School of Dental Medicine, Boston, Massachusetts
| | - Lily Q Dong
- Department of Cellular and Structural Biology, University of Texas Health Science Center at San Antonio, San Antonio, Texas
| | - Jessica Cheng
- Division of Oral Biology, Tufts University School of Dental Medicine, Boston, Massachusetts
| | - Hua Jiang
- Division of Oral Biology, Tufts University School of Dental Medicine, Boston, Massachusetts
| | - Maribel Rios
- Department of Neuroscience, Tufts University School of Medicine, Boston, Massachusetts
| | - Elise Morgan
- Departments of Mechanical Engineering, Biomedical Engineering, and Orthopedic Surgery, Boston University, Boston, Massachusetts; and
| | - Zhihui Tang
- National Engineering Laboratory for Digital and Material Technology of Stomatology, Peking University School and Hospital of Stomatology, Beijing, China; Second Dental Center, Peking University School and Hospital of Stomatology, Beijing, China
| | - Jake Chen
- Division of Oral Biology, Tufts University School of Dental Medicine, Boston, Massachusetts; Department of Anatomy and Cell Biology, Tufts University School of Medicine and Sackler Graduate School of Biomedical Sciences, Boston, Massachusetts
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Bulloch JM, Daly CJ. Autonomic nerves and perivascular fat: interactive mechanisms. Pharmacol Ther 2014; 143:61-73. [PMID: 24560685 DOI: 10.1016/j.pharmthera.2014.02.005] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2014] [Accepted: 02/03/2014] [Indexed: 12/31/2022]
Abstract
The evidence describing the autonomic innervation of body fat is reviewed with a particular focus on the role of the sympathetic neurotransmitters. In compiling the evidence, a strong case emerges for the interaction between autonomic nerves and perivascular adipose tissue (PVAT). Adipocytes have been shown to express receptors for neurotransmitters released from nearby sympathetic varicosities such as adrenoceptors (ARs), purinoceptors and receptors for neuropeptide Y (NPY). Noradrenaline can modulate both lipolysis (via α2- and β3-ARs) and lipogenesis (via α1- and β3-ARs). ATP can inhibit lipolysis (via P1 purinoceptors) or stimulate lipolysis (via P2y purinoceptors). NPY, which can be produced by adipocytes and sympathetic nerves, inhibits lipolysis. Thus the sympathetic triad of transmitters can influence adipocyte free fatty acid (FFA) content. Substance P (SP) released from sensory nerves has also been shown to promote lipolysis. Therefore, we propose a mechanism whereby sympathetic neurotransmission can simultaneously activate smooth muscle cells in the tunica media to cause vasoconstriction and alter FFA content and release from adjacent adipocytes in PVAT. The released FFA can influence endothelial function. Adipocytes also release a range of vasoactive substances, both relaxing and contractile factors, including adiponectin and reactive oxygen species. The action of adipokines (such as adiponectin) and reactive oxygen species (ROS) on cells of the vascular adventitia and nerves has yet to be fully elucidated. We hypothesise a strong link between PVAT and autonomic fibres and suggest that this poorly understood relationship is extremely important for normal vascular function and warrants a detailed study.
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Affiliation(s)
- Janette M Bulloch
- School of Science, University of the West of Scotland, Hamilton ML3 0JB, Scotland.
| | - Craig J Daly
- School of Life Sciences, University of Glasgow, Glasgow G128QQ, Scotland.
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Lamming DW, Demirkan G, Boylan JM, Mihaylova MM, Peng T, Ferreira J, Neretti N, Salomon A, Sabatini DM, Gruppuso PA. Hepatic signaling by the mechanistic target of rapamycin complex 2 (mTORC2). FASEB J 2013; 28:300-15. [PMID: 24072782 DOI: 10.1096/fj.13-237743] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The mechanistic target of rapamycin (mTOR) exists in two complexes that regulate diverse cellular processes. mTOR complex 1 (mTORC1), the canonical target of rapamycin, has been well studied, whereas the physiological role of mTORC2 remains relatively uncharacterized. In mice in which the mTORC2 component Rictor is deleted in liver [Rictor-knockout (RKO) mice], we used genomic and phosphoproteomic analyses to characterize the role of hepatic mTORC2 in vivo. Overnight food withdrawal followed by refeeding was used to activate mTOR signaling. Rapamycin was administered before refeeding to specify mTORC2-mediated events. Hepatic mTORC2 regulated a complex gene expression and post-translational network that affects intermediary metabolism, ribosomal biogenesis, and proteasomal biogenesis. Nearly all changes in genes related to intermediary metabolic regulation were replicated in cultured fetal hepatocytes, indicating a cell-autonomous effect of mTORC2 signaling. Phosphoproteomic profiling identified mTORC2-related signaling to 144 proteins, among which were metabolic enzymes and regulators. A reduction of p38 MAPK signaling in the RKO mice represents a link between our phosphoproteomic and gene expression results. We conclude that hepatic mTORC2 exerts a broad spectrum of biological effects under physiological conditions. Our findings provide a context for the development of targeted therapies to modulate mTORC2 signaling.
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Affiliation(s)
- Dudley W Lamming
- 3Division of Pediatric Endocrinology, Rhode Island Hospital, 593 Eddy Street, Providence, RI 02903, USA.
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Synergism between cAMP and PPARγ Signalling in the Initiation of UCP1 Gene Expression in HIB1B Brown Adipocytes. PPAR Res 2013; 2013:476049. [PMID: 23554809 PMCID: PMC3608182 DOI: 10.1155/2013/476049] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2012] [Revised: 12/14/2012] [Accepted: 12/28/2012] [Indexed: 01/11/2023] Open
Abstract
Expression of the brown adipocyte-specific gene, uncoupling protein 1 (UCP1), is increased by both PPARγ stimulation and cAMP activation through their ability to stimulate the expression of the PPAR coactivator PGC1α. In HIB1B brown preadipocytes, combination of the PPARγ agonist, rosiglitazone, and the cAMP stimulator forskolin synergistically increased UCP1 mRNA expression, but PGC1α expression was only increased additively by the two drugs. The PPARγ antagonist, GW9662, and the PKA inhibitor, H89, both inhibited UCP1 expression stimulated by rosiglitazone and forskolin but PGC1α expression was not altered to the same extent. Reporter studies demonstrated that combined rosiglitazone and forskolin synergistically activated transcription from a full length 3.1 kbp UCP1 luciferase promoter construct, but the response was only additive and much reduced when a minimal 260 bp proximal UCP1 promoter was examined. Rosiglitazone and forskolin in combination were able to synergistically stimulate promoters comprising of tandem repeats of either PPREs or CREs. We conclude that rosiglitazone and forskolin act together to synergistically activate the UCP1 promoter directly rather than by increasing PGC1α expression and by a mechanism involving cross-talk between the signalling systems regulating the CRE and PPRE on the promoters.
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Festuccia WT, Blanchard PG, Oliveira TB, Magdalon J, Paschoal VA, Richard D, Deshaies Y. PPARγ activation attenuates cold-induced upregulation of thyroid status and brown adipose tissue PGC-1α and D2. Am J Physiol Regul Integr Comp Physiol 2012; 303:R1277-85. [PMID: 23100029 PMCID: PMC3532587 DOI: 10.1152/ajpregu.00299.2012] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2012] [Accepted: 10/22/2012] [Indexed: 11/22/2022]
Abstract
Here, we investigated whether pharmacological PPARγ activation modulates key early events in brown adipose tissue (BAT) recruitment induced by acute cold exposure with the aim of unraveling the interrelationships between sympathetic and PPARγ signaling. Sprague-Dawley rats treated or not with the PPARγ ligand rosiglitazone (15 mg·kg(-1)·day(-1), 7 days) were kept at 23°C or exposed to cold (5°C) for 24 h and evaluated for BAT gene expression, sympathetic activity, thyroid status, and adrenergic signaling. Rosiglitazone did not affect the reduction in body weight gain and the increase in feed efficiency, Vo(2), and BAT sympathetic activity induced by 24-h cold exposure. Rosiglitazone strongly attenuated the increase in serum total and free T4 and T3 levels and BAT iodothyronine deiodinase type 2 (D2) and PGC-1α mRNA levels and potentiated the reduction in BAT thyroid hormone receptor (THR) β mRNA levels induced by cold. Administration of T3 to rosiglitazone-treated rats exacerbated the cold-induced increase in energy expenditure but did not restore a proper activation of D2 and PGC-1α, nor further increased uncoupling protein 1 expression. Regarding adrenergic signaling, rosiglitazone did not affect the changes in BAT cAMP content and PKA activity induced by cold. Rosiglitazone alone or in combination with cold increased CREB binding to DNA, but it markedly reduced the expression of one of its major coactivators, CREB binding protein. In conclusion, pharmacological PPARγ activation impairs short-term cold elicitation of BAT adrenergic and thyroid signaling, which may result in abnormal tissue recruitment and thermogenic activity.
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Affiliation(s)
- William T Festuccia
- Department of Physiology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
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de Queiroz KB, Rodovalho GV, Guimarães JB, de Lima DC, Coimbra CC, Evangelista EA, Guerra-Sá R. Endurance training blocks uncoupling protein 1 up-regulation in brown adipose tissue while increasing uncoupling protein 3 in the muscle tissue of rats fed with a high-sugar diet. Nutr Res 2012; 32:709-17. [PMID: 23084644 DOI: 10.1016/j.nutres.2012.06.020] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2012] [Revised: 06/16/2012] [Accepted: 06/29/2012] [Indexed: 10/27/2022]
Abstract
The mitochondrial uncoupling proteins (UCPs) of interscapular brown adipose tissue (iBAT) and of muscles play important roles in energy balance. For instance, the expression of UCP1 and UCP3 are modulated by free fatty acid gradients induced by high-sugar diets and acute exercise that is dependent on sympathetic stimulation. However, the effects of endurance training in animals fed with high-sugar diets are unknown. This study aims to evaluate the long-term effects of diet and exercise on UCP1 and UCP3 levels and energy balance efficiency. Rats fed with standard or high-sugar (HSD) diets were simultaneously subjected to running training over an 8-week period. After the training period, the rats were decapitated, and the iBAT and gastrocnemius muscle tissues were removed for evaluation of the β₃-receptor, Ucp1, and Ucp3 mRNA and protein expression, which were analyzed by quantitative reverse transcriptase polymerase chain reaction and Western blot, respectively. Groups fed with an HSD displayed a higher adiposity index and iBAT weight (P < .05), whereas exhibited an up-regulation of Ucp1 mRNA and protein levels (P < .05). Training increased β₃-receptor mRNA in iBAT and reduced the Ucp3 mRNA in muscle tissues. In association with an HSD, training restored the increasing β₃-receptor mRNA and greatly up-regulated the levels of Ucp3 mRNA. Therefore, training blocked the HSD-induced up-regulation of UCP1 expression in iBAT, whereas it up-regulated the expression of Ucp3 mRNA in muscle. These results suggest that training enhances the relationship between Ucp1/Ucp3 mRNA levels, which could result in higher energy efficiency, but not when HSD-induced elevated sympathetic activity is maintained.
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Affiliation(s)
- Karina Barbosa de Queiroz
- Departmento de Ciências Biológicas-NUPEB, Laboratório de Bioquímica e Biologia Molecular, ICEB-Universidade Federal de Ouro Preto, Ouro Preto, MG, Brazil
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Genome-wide profiling of peroxisome proliferator-activated receptor γ in primary epididymal, inguinal, and brown adipocytes reveals depot-selective binding correlated with gene expression. Mol Cell Biol 2012; 32:3452-63. [PMID: 22733994 DOI: 10.1128/mcb.00526-12] [Citation(s) in RCA: 97] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Peroxisome proliferator-activated receptor γ (PPARγ) is a master regulator of adipocyte differentiation and function. We and others have previously mapped PPARγ binding at a genome-wide level in murine and human adipocyte cell lines and in primary human adipocytes. However, little is known about how binding patterns of PPARγ differ between brown and white adipocytes and among different types of white adipocytes. Here we have employed chromatin immunoprecipitation combined with deep sequencing to map and compare PPARγ binding in in vitro differentiated primary mouse adipocytes isolated from epididymal, inguinal, and brown adipose tissues. While these PPARγ binding profiles are overall similar, there are clear depot-selective binding sites. Most PPARγ binding sites previously mapped in 3T3-L1 adipocytes can also be detected in primary adipocytes, but there are a large number of PPARγ binding sites that are specific to the primary cells, and these tend to be located in closed chromatin regions in 3T3-L1 adipocytes. The depot-selective binding of PPARγ is associated with highly depot-specific gene expression. This indicates that PPARγ plays a role in the induction of genes characteristic of different adipocyte lineages and that preadipocytes from different depots are differentially preprogrammed to permit PPARγ lineage-specific recruitment even when differentiated in vitro.
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Lamming DW, Ye L, Katajisto P, Goncalves MD, Saitoh M, Stevens DM, Davis JG, Salmon AB, Richardson A, Ahima RS, Guertin DA, Sabatini DM, Baur JA. Rapamycin-induced insulin resistance is mediated by mTORC2 loss and uncoupled from longevity. Science 2012; 335:1638-43. [PMID: 22461615 DOI: 10.1126/science.1215135] [Citation(s) in RCA: 870] [Impact Index Per Article: 72.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Rapamycin, an inhibitor of mechanistic target of rapamycin complex 1 (mTORC1), extends the life spans of yeast, flies, and mice. Calorie restriction, which increases life span and insulin sensitivity, is proposed to function by inhibition of mTORC1, yet paradoxically, chronic administration of rapamycin substantially impairs glucose tolerance and insulin action. We demonstrate that rapamycin disrupted a second mTOR complex, mTORC2, in vivo and that mTORC2 was required for the insulin-mediated suppression of hepatic gluconeogenesis. Further, decreased mTORC1 signaling was sufficient to extend life span independently from changes in glucose homeostasis, as female mice heterozygous for both mTOR and mLST8 exhibited decreased mTORC1 activity and extended life span but had normal glucose tolerance and insulin sensitivity. Thus, mTORC2 disruption is an important mediator of the effects of rapamycin in vivo.
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Affiliation(s)
- Dudley W Lamming
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA
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Cloning and ontogenetic expression of the uncoupling protein 1 gene UCP1 in sheep. J Appl Genet 2012; 53:203-12. [DOI: 10.1007/s13353-012-0086-0] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2011] [Revised: 01/26/2012] [Accepted: 01/26/2012] [Indexed: 12/19/2022]
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Poulsen LLC, Siersbæk M, Mandrup S. PPARs: fatty acid sensors controlling metabolism. Semin Cell Dev Biol 2012; 23:631-9. [PMID: 22273692 DOI: 10.1016/j.semcdb.2012.01.003] [Citation(s) in RCA: 340] [Impact Index Per Article: 28.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2011] [Accepted: 01/09/2012] [Indexed: 12/13/2022]
Abstract
The peroxisome proliferator activated receptors (PPARs) are nuclear receptors that play key roles in the regulation of lipid metabolism, inflammation, cellular growth, and differentiation. The receptors bind and are activated by a broad range of fatty acids and fatty acid derivatives and they thereby serve as major transcriptional sensors of fatty acids. Here we review the function, regulation, and mechanism of the different PPAR subtypes with special emphasis on their role in the regulation of lipid metabolism.
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Affiliation(s)
- Lars la Cour Poulsen
- University of Southern Denmark, Department of Biochemistry and Molecular Biology, Campusvej 55, DK-5230, Odense M, Denmark.
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Kazantzis M, Takahashi V, Hinkle J, Kota S, Zilberfarb V, Issad T, Abdelkarim M, Chouchane L, Strosberg AD. PAZ6 cells constitute a representative model for human brown pre-adipocytes. Front Endocrinol (Lausanne) 2012; 3:13. [PMID: 22649407 PMCID: PMC3355992 DOI: 10.3389/fendo.2012.00013] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/25/2011] [Accepted: 01/14/2012] [Indexed: 11/13/2022] Open
Abstract
The role of brown adipose tissue (BAT) in human metabolism and its potential as an anti-obesity target organ have recently received much renewed attention. Following radiological detection of substantial amounts of BAT in adults by several independent research groups, an increasing number of studies are now dedicated to uncover BAT's genetic, developmental, and environmental determinants. In contrast to murine BAT, human BAT is not present as a single major fat depot in a well-defined location. The distribution of BAT in several areas in the body significantly limits its availability to research. A human brown adipocyte cell line is therefore critical in broadening the options available to researchers in the field. The human BAT-cell line PAZ6 was created to address such a need and has been well characterized by several research groups around the world. In the present review, we discuss their findings and propose potential applications of the PAZ6 cells in addressing the relevant questions in the BAT field, namely for future use in therapeutic applications.
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Affiliation(s)
- Melissa Kazantzis
- Department of Infectology, The Scripps Research Institute-FloridaJupiter, FL, USA
- *Correspondence: Melissa Kazantzis, Department of Infectology, The Scripps Research Institute-Florida, 120 Scripps Way, #B110, Jupiter FL, 33458, USA. e-mail:
| | - Virginia Takahashi
- Department of Infectology, The Scripps Research Institute-FloridaJupiter, FL, USA
| | - Jessica Hinkle
- Department of Infectology, The Scripps Research Institute-FloridaJupiter, FL, USA
| | - Smitha Kota
- Department of Infectology, The Scripps Research Institute-FloridaJupiter, FL, USA
| | - Vladimir Zilberfarb
- INSERM U1016Paris, France
- CNRS-UMR8104Paris, France
- Département de Biologie Cellulaire, Université Paris DescartesParis, France
| | - Tarik Issad
- INSERM U1016Paris, France
- CNRS-UMR8104Paris, France
- Département de Biologie Cellulaire, Université Paris DescartesParis, France
| | - Mouaadh Abdelkarim
- Department of Genetic Medicine, Weill Cornell Medical College in QatarDoha, Qatar
| | - Lotfi Chouchane
- Department of Genetic Medicine, Weill Cornell Medical College in QatarDoha, Qatar
| | - Arthur Donny Strosberg
- Department of Infectology, The Scripps Research Institute-FloridaJupiter, FL, USA
- INSERM U1016Paris, France
- Institut Cochin INSERM U1016, Université Paris7-Denis-DiderotParis, France
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Coleman RA, Mashek DG. Mammalian triacylglycerol metabolism: synthesis, lipolysis, and signaling. Chem Rev 2011; 111:6359-86. [PMID: 21627334 PMCID: PMC3181269 DOI: 10.1021/cr100404w] [Citation(s) in RCA: 205] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Rosalind A Coleman
- Department of Nutrition, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA.
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Marino JS, Xu Y, Hill JW. Central insulin and leptin-mediated autonomic control of glucose homeostasis. Trends Endocrinol Metab 2011; 22:275-85. [PMID: 21489811 PMCID: PMC5154334 DOI: 10.1016/j.tem.2011.03.001] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/02/2010] [Revised: 02/25/2011] [Accepted: 03/05/2011] [Indexed: 12/17/2022]
Abstract
Largely as a result of rising obesity rates, the incidence of type 2 diabetes is escalating rapidly. Type 2 diabetes results from multi-organ dysfunctional glucose metabolism. Recent publications have highlighted hypothalamic insulin- and adipokine-sensing as a major determinant of peripheral glucose and insulin responsiveness. The preponderance of evidence indicates that the brain is the master regulator of glucose homeostasis, and that hypothalamic insulin and leptin signaling in particular play a crucial role in the development of insulin resistance. This review discusses the neuronal crosstalk between the hypothalamus, autonomic nervous system, and tissues associated with the pathogenesis of type 2 diabetes, and how hypothalamic insulin and leptin signaling are integral to maintaining normal glucose homeostasis.
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Affiliation(s)
- Joseph S Marino
- Center for Diabetes and Endocrine Research, College of Medicine, The University of Toledo, Toledo, OH 43614, USA
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Festuccia WT, Blanchard PG, Deshaies Y. Control of Brown Adipose Tissue Glucose and Lipid Metabolism by PPARγ. Front Endocrinol (Lausanne) 2011; 2:84. [PMID: 22654830 PMCID: PMC3356105 DOI: 10.3389/fendo.2011.00084] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/30/2011] [Accepted: 11/12/2011] [Indexed: 11/29/2022] Open
Abstract
Brown adipose tissue (BAT) non-shivering thermogenesis impacts energy homeostasis in rodents and humans. Mitochondrial uncoupling protein 1 in brown fat cells produces heat by dissipating the energy generated by fatty acid and glucose oxidation. In addition to thermogenesis and despite its small relative size, sympathetically activated BAT constitutes an important glucose, fatty acid, and triacylglycerol-clearing organ, and such function could potentially be used to alleviate dyslipidemias, hyperglycemia, and insulin resistance. To date, chronic sympathetic innervation and peroxisome proliferator-activated receptor (PPAR) γ activation are the only recognized inducers of BAT recruitment. Here, we review the major differences between these two BAT inducers in the regulation of lipolysis, fatty acid oxidation, lipid uptake and triacylglycerol synthesis, glucose uptake, and de novo lipogenesis. Whereas BAT recruitment through sympathetic drive translates into functional thermogenic activity, PPARγ-mediated recruitment is associated with a reduction in sympathetic activity leading to increased lipid storage in brown adipocytes. The promising therapeutic role of BAT in the treatment of hypertriglyceridemic and hyperglycemic conditions is also discussed.
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Affiliation(s)
- William T. Festuccia
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São PauloSão Paulo, Brazil
| | | | - Yves Deshaies
- Department of Medicine, Quebec Heart and Lung InstituteQuebec, QC, Canada
- *Correspondence: Yves Deshaies, Quebec Heart and Lung Institute, Pavillon Margeritte d’Youville Y3110, 2725 Chemin Sainte-Foy, Quebec, QC, Canada G1V 4G5. e-mail:
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