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Duteil D, Tosic M, Schüle R. Lsd1, a metabolic sensor of environment requirements that prevents adipose tissue from aging. Adipocyte 2017; 6:298-303. [PMID: 28700271 DOI: 10.1080/21623945.2017.1345831] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Understanding development and maintenance of beige adipocytes provide exciting insights in establishing novel therapies against obesity and obesity-associated disorders. Lysine-specific demethylase 1 (Lsd1) is an epigenetic eraser required for differentiation and function of adipocytes. Lsd1 is involved in early commitment of preadipocytes, but dispensable for terminal differentiation of white adipose tissue (WAT). In mature adipocytes, Lsd1 responds to different environmental stimuli to alter metabolic function and enable proper thermogenic and oxidative response. Exposure to cold leads to Lsd1 upregulation and subsequent beiging of WAT. Oppositely, Lsd1 levels decline during aging resulting in a conversion of beige into white adipocytes, associated with loss of thermogenic properties of WAT. Lsd1 maintains beige adipocytes by controlling the expression of the nuclear receptor peroxisome proliferator-activated receptor α. In summary, our studies not only provided insights into the mechanism of age-related beige-to-white adipocyte transition, but also established Lsd1 as a sensor that enables thermogenic response in WAT.
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Affiliation(s)
- Delphine Duteil
- Urologische Klinik und Zentrale Klinische Forschung, Klinikum der Universität Freiburg, Freiburg, Germany
| | - Milica Tosic
- Urologische Klinik und Zentrale Klinische Forschung, Klinikum der Universität Freiburg, Freiburg, Germany
| | - Roland Schüle
- Urologische Klinik und Zentrale Klinische Forschung, Klinikum der Universität Freiburg, Freiburg, Germany
- BIOSS Centre of Biological Signalling Studies, Albert-Ludwigs-University, Freiburg, Germany
- Deutsche Konsortium für Translationale Krebsforschung (DKTK), Standort Freiburg, Germany
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Abstract
Mitochondria are essential organelles for many aspects of cellular homeostasis, including energy harvesting through oxidative phosphorylation. Alterations of mitochondrial function not only impact on cellular metabolism but also critically influence whole-body metabolism, health, and life span. Diseases defined by mitochondrial dysfunction have expanded from rare monogenic disorders in a strict sense to now also include many common polygenic diseases, including metabolic, cardiovascular, neurodegenerative, and neuromuscular diseases. This has led to an intensive search for new therapeutic and preventive strategies aimed at invigorating mitochondrial function by exploiting key components of mitochondrial biogenesis, redox metabolism, dynamics, mitophagy, and the mitochondrial unfolded protein response. As such, new findings linking mitochondrial function to the progression or outcome of this ever-increasing list of diseases has stimulated the discovery and development of the first true mitochondrial drugs, which are now entering the clinic and are discussed in this review.
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Affiliation(s)
- Vincenzo Sorrentino
- Laboratory of Integrative and Systems Physiology, École Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland;
| | - Keir J Menzies
- Interdisciplinary School of Health Sciences, University of Ottawa Brain and Mind Research Institute and Centre for Neuromuscular Disease, Ottawa K1H 8M5, Canada;
| | - Johan Auwerx
- Laboratory of Integrative and Systems Physiology, École Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland;
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de Vera IMS, Zheng J, Novick S, Shang J, Hughes TS, Brust R, Munoz-Tello P, Gardner WJ, Marciano DP, Kong X, Griffin PR, Kojetin DJ. Synergistic Regulation of Coregulator/Nuclear Receptor Interaction by Ligand and DNA. Structure 2017; 25:1506-1518.e4. [PMID: 28890360 DOI: 10.1016/j.str.2017.07.019] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2017] [Revised: 06/12/2017] [Accepted: 07/28/2017] [Indexed: 11/15/2022]
Abstract
Nuclear receptor (NR) transcription factors bind various coreceptors, small-molecule ligands, DNA response element sequences, and transcriptional coregulator proteins to affect gene transcription. Small-molecule ligands and DNA are known to influence receptor structure, coregulator protein interaction, and function; however, little is known on the mechanism of synergy between ligand and DNA. Using quantitative biochemical, biophysical, and solution structural methods, including 13C-detected nuclear magnetic resonance and hydrogen/deuterium exchange (HDX) mass spectrometry, we show that ligand and DNA cooperatively recruit the intrinsically disordered steroid receptor coactivator-2 (SRC-2/TIF2/GRIP1/NCoA-2) receptor interaction domain to peroxisome proliferator-activated receptor gamma-retinoid X receptor alpha (PPARγ-RXRα) heterodimer and reveal the binding determinants of the complex. Our data reveal a thermodynamic mechanism by which DNA binding propagates a conformational change in PPARγ-RXRα, stabilizes the receptor ligand binding domain dimer interface, and impacts ligand potency and cooperativity in NR coactivator recruitment.
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Affiliation(s)
- Ian Mitchelle S de Vera
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, Scripps Florida, Jupiter, FL 33458, USA; Department of Molecular Medicine, The Scripps Research Institute, Scripps Florida, Jupiter, FL 33458, USA
| | - Jie Zheng
- Department of Molecular Medicine, The Scripps Research Institute, Scripps Florida, Jupiter, FL 33458, USA
| | - Scott Novick
- Department of Molecular Medicine, The Scripps Research Institute, Scripps Florida, Jupiter, FL 33458, USA
| | - Jinsai Shang
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, Scripps Florida, Jupiter, FL 33458, USA; Department of Molecular Medicine, The Scripps Research Institute, Scripps Florida, Jupiter, FL 33458, USA
| | - Travis S Hughes
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, Scripps Florida, Jupiter, FL 33458, USA; Department of Molecular Medicine, The Scripps Research Institute, Scripps Florida, Jupiter, FL 33458, USA
| | - Richard Brust
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, Scripps Florida, Jupiter, FL 33458, USA; Department of Molecular Medicine, The Scripps Research Institute, Scripps Florida, Jupiter, FL 33458, USA
| | - Paola Munoz-Tello
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, Scripps Florida, Jupiter, FL 33458, USA; Department of Molecular Medicine, The Scripps Research Institute, Scripps Florida, Jupiter, FL 33458, USA
| | - William J Gardner
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, Scripps Florida, Jupiter, FL 33458, USA; Department of Molecular Medicine, The Scripps Research Institute, Scripps Florida, Jupiter, FL 33458, USA; TSRI High School Student Summer Internship Program, The Scripps Research Institute, Scripps Florida, Jupiter, FL 33458, USA
| | - David P Marciano
- Department of Molecular Medicine, The Scripps Research Institute, Scripps Florida, Jupiter, FL 33458, USA
| | - Xiangming Kong
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, Scripps Florida, Jupiter, FL 33458, USA; Department of Molecular Medicine, The Scripps Research Institute, Scripps Florida, Jupiter, FL 33458, USA
| | - Patrick R Griffin
- Department of Molecular Medicine, The Scripps Research Institute, Scripps Florida, Jupiter, FL 33458, USA
| | - Douglas J Kojetin
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, Scripps Florida, Jupiter, FL 33458, USA; Department of Molecular Medicine, The Scripps Research Institute, Scripps Florida, Jupiter, FL 33458, USA.
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Na I, Meng F, Kurgan L, Uversky VN. Autophagy-related intrinsically disordered proteins in intra-nuclear compartments. MOLECULAR BIOSYSTEMS 2017; 12:2798-817. [PMID: 27377881 DOI: 10.1039/c6mb00069j] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Recent analyses indicated that autophagy can be regulated via some nuclear transcriptional networks and many important players in the autophagy and other forms of programmed cell death are known to be intrinsically disordered. To this end, we analyzed similarities and differences in the intrinsic disorder distribution of nuclear and non-nuclear proteins related to autophagy. We also looked at the peculiarities of the distribution of the intrinsically disordered autophagy-related proteins in various intra-nuclear organelles, such as the nucleolus, chromatin, Cajal bodies, nuclear speckles, promyelocytic leukemia (PML) nuclear bodies, nuclear lamina, nuclear pores, and perinucleolar compartment. This analysis revealed that the autophagy-related proteins constitute about 2.5% of the non-nuclear proteins and 3.3% of the nuclear proteins, which corresponds to a substantial enrichment by about 32% in the nucleus. Curiously, although, in general, the autophagy-related proteins share similar characteristics of disorder with a generic set of all non-nuclear proteins, chromatin and nuclear speckles are enriched in the intrinsically disordered autophagy proteins (29 and 37% of these proteins are disordered, respectively) and have high disorder content at 0.24 and 0.27, respectively. Therefore, our data suggest that some of the nuclear disordered proteins may play important roles in autophagy.
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Affiliation(s)
- Insung Na
- Department of Molecular Medicine, Morsani College of Medicine, University of South Florida, Tampa, FL 33612, USA.
| | - Fanchi Meng
- Department of Electrical and Computer Engineering, University of Alberta, Edmonton, Alberta T6G 2V4, Canada
| | - Lukasz Kurgan
- Department of Computer Science, Virginia Commonwealth University, Richmond, VA 23219, USA.
| | - Vladimir N Uversky
- Department of Molecular Medicine, Morsani College of Medicine, University of South Florida, Tampa, FL 33612, USA. and USF Health Byrd Alzheimer's Research Institute, Morsani College of Medicine, University of South Florida, Tampa, FL 33612, USA and Biology Department, Faculty of Science, King Abdulaziz University, P.O. Box 80203, Jeddah 21589, Saudi Arabia and Laboratory of Structural Dynamics, Stability and Folding of Proteins, Institute of Cytology, Russian Academy of Sciences, St. Petersburg 194064, Russia
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Patil M, Sharma BK, Elattar S, Chang J, Kapil S, Yuan J, Satyanarayana A. Id1 Promotes Obesity by Suppressing Brown Adipose Thermogenesis and White Adipose Browning. Diabetes 2017; 66:1611-1625. [PMID: 28270523 PMCID: PMC5440025 DOI: 10.2337/db16-1079] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/08/2016] [Accepted: 03/01/2017] [Indexed: 12/31/2022]
Abstract
Obesity results from increased energy intake or defects in energy expenditure. Brown adipose tissue (BAT) is specialized for energy expenditure, a process called adaptive thermogenesis. Peroxisome proliferator-activated receptor γ coactivator 1α (PGC1α) controls BAT-mediated thermogenesis by regulating the expression of Ucp1 Inhibitor of differentiation 1 (Id1) is a helix-loop-helix transcription factor that plays an important role in cell proliferation and differentiation. We demonstrate a novel function of Id1 in BAT thermogenesis and programming of beige adipocytes in white adipose tissue (WAT). We found that adipose tissue-specific overexpression of Id1 causes age-associated and high-fat diet-induced obesity in mice. Id1 suppresses BAT thermogenesis by binding to and suppressing PGC1α transcriptional activity. In WAT, Id1 is mainly localized in the stromal vascular fraction, where the adipose progenitor/precursors reside. Lack of Id1 increases beige gene and Ucp1 expression in the WAT in response to cold exposure. Furthermore, brown-like differentiation is increased in Id1-deficient mouse embryonic fibroblasts. At the molecular level, Id1 directly interacts with and suppresses Ebf2 transcriptional activity, leading to reduced expression of Prdm16, which determines beige/brown adipocyte cell fate. Overall, the study highlights the existence of novel regulatory mechanisms between Id1/PGC1α and Id1/Ebf2 in controlling brown fat metabolism, which has significant implications in the treatment of obesity and its associated diseases, such as diabetes.
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Affiliation(s)
- Mallikarjun Patil
- Department of Biochemistry and Molecular Biology, Molecular Oncology and Biomarkers Program, Georgia Cancer Center, Augusta University, Augusta, GA
| | - Bal Krishan Sharma
- Department of Biochemistry and Molecular Biology, Molecular Oncology and Biomarkers Program, Georgia Cancer Center, Augusta University, Augusta, GA
| | - Sawsan Elattar
- Department of Biochemistry and Molecular Biology, Molecular Oncology and Biomarkers Program, Georgia Cancer Center, Augusta University, Augusta, GA
| | - Judith Chang
- Department of Biochemistry and Molecular Biology, Molecular Oncology and Biomarkers Program, Georgia Cancer Center, Augusta University, Augusta, GA
| | - Shweta Kapil
- Department of Biochemistry and Molecular Biology, Molecular Oncology and Biomarkers Program, Georgia Cancer Center, Augusta University, Augusta, GA
| | - Jinling Yuan
- Department of Biochemistry and Molecular Biology, Molecular Oncology and Biomarkers Program, Georgia Cancer Center, Augusta University, Augusta, GA
| | - Ande Satyanarayana
- Department of Biochemistry and Molecular Biology, Molecular Oncology and Biomarkers Program, Georgia Cancer Center, Augusta University, Augusta, GA
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Abstract
Aging is accompanied by major changes in adipose tissue distribution and function. In particular, with time, thermogenic-competent beige adipocytes progressively gain a white adipocyte morphology. However, the mechanisms controlling the age-related transition of beige adipocytes to white adipocytes remain unclear. Lysine-specific demethylase 1 (Lsd1) is an epigenetic eraser enzyme positively regulating differentiation and function of adipocytes. Here we show that Lsd1 levels decrease in aging inguinal white adipose tissue concomitantly with beige fat cell decline. Accordingly, adipocyte-specific increase of Lsd1 expression is sufficient to rescue the age-related transition of beige adipocytes to white adipocytes in vivo, whereas loss of Lsd1 precipitates it. Lsd1 maintains beige adipocytes by controlling the expression of peroxisome proliferator-activated receptor α (Ppara), and treatment with a Ppara agonist is sufficient to rescue the loss of beige adipocytes caused by Lsd1 ablation. In summary, our data provide insights into the mechanism controlling the age-related beige-to-white adipocyte transition and identify Lsd1 as a regulator of beige fat cell maintenance.
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Xu Y, O'Malley BW, Elmquist JK. Brain nuclear receptors and body weight regulation. J Clin Invest 2017; 127:1172-1180. [PMID: 28218618 DOI: 10.1172/jci88891] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Neural pathways, especially those in the hypothalamus, integrate multiple nutritional, hormonal, and neural signals, resulting in the coordinated control of body weight balance and glucose homeostasis. Nuclear receptors (NRs) sense changing levels of nutrients and hormones, and therefore play essential roles in the regulation of energy homeostasis. Understanding the role and the underlying mechanisms of NRs in the context of energy balance control may facilitate the identification of novel targets to treat obesity. Notably, NRs are abundantly expressed in the brain, and emerging evidence indicates that a number of these brain NRs regulate multiple aspects of energy balance, including feeding, energy expenditure and physical activity. In this Review we summarize some of the recent literature regarding effects of brain NRs on body weight regulation and discuss mechanisms underlying these effects.
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Abstract
Insulin resistance is one of the defining features of type 2 diabetes and the metabolic syndrome and accompanies many other clinical conditions, ranging from obesity to lipodystrophy to glucocorticoid excess. Extraordinary efforts have gone into defining the mechanisms that underlie insulin resistance, with most attention focused on altered signalling as well as mitochondrial and endoplasmic reticulum stress. Here, nuclear mechanisms of insulin resistance, including transcriptional and epigenomic effects, will be discussed. Three levels of control involving transcription factors, transcriptional cofactors, and chromatin-modifying enzymes will be considered. Well-studied examples of the first include PPAR-γ in adipose tissue and the glucocorticoid receptor and FoxO1 in a variety of insulin-sensitive tissues. These proteins work in concert with cofactors such as PGC-1α and CRTC2, and chromatin-modifying enzymes including DNA methyltransferases and histone acetyltransferases, to regulate key genes that promote insulin-stimulated glucose uptake, gluconeogenesis or other pathways that affect systemic insulin action. Furthermore, genetic variation associated with increased risk of type 2 diabetes is often related to altered transcription factor binding, either by affecting the transcription factor itself, or more commonly by changing the binding affinity of a noncoding regulatory region. Finally, several avenues for therapeutic exploitation in the battle against metabolic disease will be discussed, including small-molecule inhibitors and activators of these factors and their related pathways.
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Affiliation(s)
- E D Rosen
- Division of Endocrinology and Metabolism, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, USA.
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59
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Maughan RT, Feeney ER, Capel E, Capeau J, Domingo P, Giralt M, Lange JMA, Phanuphak P, Cooper DA, Reiss P, Mallon PWG. Improved adipose tissue function with initiation of protease inhibitor-only ART. J Antimicrob Chemother 2016; 71:3212-3221. [PMID: 27516476 PMCID: PMC5079304 DOI: 10.1093/jac/dkw301] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2016] [Accepted: 06/27/2016] [Indexed: 01/28/2023] Open
Abstract
OBJECTIVES Use of ART containing HIV PIs has previously been associated with toxicity in subcutaneous adipose tissue (SAT), potentially contributing to the development of lipodystrophy and insulin resistance. However, the effect of PIs on SAT function in ART-naive patients independent of other ART classes is unknown. This study aimed to elucidate the effect of initiating PI-only ART on SAT function in ART-naive subjects. METHODS In the HIVNAT-019 study, 48 HIV-infected, ART-naive Thai adults commencing PI-only ART comprising lopinavir/ritonavir/saquinavir for 24 weeks underwent assessments of fasting metabolic parameters and body composition. In a molecular substudy, 20 subjects underwent SAT biopsies at weeks 0, 2 and 24 for transcriptional, protein, mitochondrial DNA (mtDNA) and histological analyses. ClinicalTrials.gov registration number: NCT00400738. RESULTS Over 24 weeks, limb fat increased (+416.4 g, P = 0.023), coinciding with larger adipocytes as indicated by decreased adipocyte density in biopsies (-32.3 cells/mm2, P = 0.047) and increased mRNA expression of adipogenesis regulator PPARG at week 2 (+58.1%, P = 0.003). Increases in mtDNA over 24 weeks (+600 copies/cell, P = 0.041), decreased NRF1 mRNA expression at week 2 (-33.7%, P < 0.001) and increased COX2/COX4 protein ratio at week 24 (+288%, P = 0.038) indicated improved mitochondrial function. Despite decreased AKT2 mRNA at week 2 (-28.6%, P = 0.002) and increased PTPN1 mRNA at week 24 (+50.3%, P = 0.016) suggesting insulin resistance, clinical insulin sensitivity [by homeostasis model assessment (HOMA-IR)] was unchanged. CONCLUSIONS Initiation of PI-only ART showed little evidence of SAT toxicity, the changes observed being consistent with a return to health rather than contributing to lipodystrophy.
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Affiliation(s)
- Robert T Maughan
- HIV Molecular Research Group, School of Medicine, University College Dublin, Dublin, Ireland
| | - Eoin R Feeney
- HIV Molecular Research Group, School of Medicine, University College Dublin, Dublin, Ireland
| | - Emilie Capel
- Sorbonne Universities, UPMC Univ Paris 06, INSERM UMRS 938, Paris, France
| | - Jacqueline Capeau
- Sorbonne Universities, UPMC Univ Paris 06, INSERM UMRS 938, Paris, France
| | - Pere Domingo
- Infectious Diseases Unit, Hospital de la Santa Creu/Sant Pau, Barcelona, Spain
| | - Marta Giralt
- Department of Biochemistry and Molecular Biology, University of Barcelona, Barcelona, Spain
- CIBER Fisiopatologia de la Obesidad y Nutrición, Barcelona, Spain
| | - Joep M A Lange
- Academic Medical Center, Department of Global Health and Division of Infectious Diseases, and Amsterdam Institute for Global Health and Development, Amsterdam, The Netherlands
- The HIV-Netherlands Australia Thailand Research Collaboration (HIV-NAT) - Thai Red Cross Aids Research Center (TRCARC), Bangkok, Thailand
| | - Praphan Phanuphak
- The HIV-Netherlands Australia Thailand Research Collaboration (HIV-NAT) - Thai Red Cross Aids Research Center (TRCARC), Bangkok, Thailand
- Department of Medicine, Chulalongkorn University, Bangkok, Thailand
| | - David A Cooper
- Kirby Institute, University of New South Wales, Sydney, Australia
| | - Peter Reiss
- Academic Medical Center, Department of Global Health and Division of Infectious Diseases, and Amsterdam Institute for Global Health and Development, Amsterdam, The Netherlands
- The HIV-Netherlands Australia Thailand Research Collaboration (HIV-NAT) - Thai Red Cross Aids Research Center (TRCARC), Bangkok, Thailand
| | - Patrick W G Mallon
- HIV Molecular Research Group, School of Medicine, University College Dublin, Dublin, Ireland
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Arbones-Mainar JM, Johnson LA, Torres-Perez E, Garcia AE, Perez-Diaz S, Raber J, Maeda N. Metabolic shifts toward fatty-acid usage and increased thermogenesis are associated with impaired adipogenesis in mice expressing human APOE4. Int J Obes (Lond) 2016; 40:1574-1581. [PMID: 27163745 PMCID: PMC5063049 DOI: 10.1038/ijo.2016.93] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/05/2016] [Revised: 03/31/2016] [Accepted: 04/23/2016] [Indexed: 11/09/2022]
Abstract
BACKGROUND The Apolipoprotein E (APOE) gene encodes for three isoforms in the human population (APOE2, APOE3 and APOE4). Whereas the role of APOE in lipid metabolism is well characterized, the specific metabolic signatures of the APOE isoforms during metabolic disorders, remain unclear. OBJECTIVE To elucidate the molecular underpinnings of APOE-directed metabolic alterations, we tested the hypothesis that APOE4 drives a whole-body metabolic shift toward increased lipid oxidation. METHODS We employed humanized mice in which the Apoe gene has been replaced by the human APOE*3 or APOE*4 allele to produce human APOE3 or APOE4 proteins and characterized several mechanisms of fatty-acid oxidation, lipid storage, substrate utilization and thermogenesis in those mice. RESULTS We show that, whereas APOE4 mice gained less body weight and mass than their APOE3 counterparts on a Western-type diet (P<0.001), they displayed elevated insulin and homeostatic model assessment, markers of insulin resistance (P=0.004 and P=0.025, respectively). APOE4 mice also demonstrated a reduced respiratory quotient during the postprandial period (0.95±0.03 versus 1.06±0.03, P<0.001), indicating increased usage of lipids as opposed to carbohydrates as a fuel source. Finally, APOE4 mice showed increased body temperature (37.30±0.68 versus 36.9±0.58 °C, P=0.039), augmented cold tolerance and more metabolically active brown adipose tissue compared with APOE3 mice. CONCLUSION These data suggest that APOE4 mice may resist weight gain via an APOE4-directed global metabolic shift toward lipid oxidation and enhanced thermogenesis, and may represent a critical first step in the development of APOE-directed therapies for a large percentage of the population affected by disorders with established links to APOE and metabolism.
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Affiliation(s)
- Jose M. Arbones-Mainar
- Adipocyte and Fat Biology Laboratory (AdipoFat). Instituto de Investigacion Sanitaria (IIS) Aragon, Instituto Aragonés de Ciencias de la Salud (IACS), Hospital Universitario Miguel Servet, Zaragoza 50009, Spain
- CIBER Fisiopatología Obesidad y Nutrición (CIBERObn), Instituto Salud Carlos III, Madrid, Spain
- Department of Pathology and Laboratory Medicine, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
| | - Lance A. Johnson
- Department of Pathology and Laboratory Medicine, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
- Department of Behavioral Neuroscience, Oregon Health & Science University
| | - Elena Torres-Perez
- Adipocyte and Fat Biology Laboratory (AdipoFat). Instituto de Investigacion Sanitaria (IIS) Aragon, Instituto Aragonés de Ciencias de la Salud (IACS), Hospital Universitario Miguel Servet, Zaragoza 50009, Spain
| | - Anna E. Garcia
- Department of Pathology and Laboratory Medicine, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
| | - Sergio Perez-Diaz
- Adipocyte and Fat Biology Laboratory (AdipoFat). Instituto de Investigacion Sanitaria (IIS) Aragon, Instituto Aragonés de Ciencias de la Salud (IACS), Hospital Universitario Miguel Servet, Zaragoza 50009, Spain
| | - Jacob Raber
- Department of Behavioral Neuroscience, Oregon Health & Science University
- Departments of Neurology and Radiation Medicine, Division of Neuroscience, ONPRC, Oregon Health & Science University, Portland, Oregon 97239, USA
| | - Nobuyo Maeda
- Department of Pathology and Laboratory Medicine, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
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Lonard DM, O'Malley BW. Molecular Pathways: Targeting Steroid Receptor Coactivators in Cancer. Clin Cancer Res 2016; 22:5403-5407. [PMID: 27654711 DOI: 10.1158/1078-0432.ccr-15-1958] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2016] [Revised: 08/24/2016] [Accepted: 09/01/2016] [Indexed: 11/16/2022]
Abstract
Coactivators represent a large class of proteins that partner with nuclear receptors and other transcription factors to regulate gene expression. Given their pleiotropic roles in the control of transcription, coactivators have been implicated in a broad range of human disease states, including cancer. This is best typified by the three members of the steroid receptor coactivator (SRC) family, each of which integrates steroid hormone signaling and growth factor pathways to drive oncogenic gene expression programs in breast, endometrial, ovarian, prostate, and other cancers. Because of this, coactivators represent emerging targets for cancer therapeutics, and efforts are now being made to develop SRC-targeting agents, such as the SI-2 inhibitor and the novel SRC stimulator, MCB-613, that are able to block cancer growth in cell culture and animal model systems. Here, we will discuss the mechanisms through which coactivators drive cancer progression and how targeting coactivators represent a novel conceptual approach to combat tumor growth that is distinct from the use of other targeted therapeutic agents. We also will describe efforts to develop next-generation SRC inhibitors and stimulators that can be taken into the clinic for the treatment of recurrent, drug-resistant cancers. Clin Cancer Res; 22(22); 5403-7. ©2016 AACR.
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Affiliation(s)
- David M Lonard
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, Texas
| | - Bert W O'Malley
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, Texas.
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Coppo M, Chinenov Y, Sacta MA, Rogatsky I. The transcriptional coregulator GRIP1 controls macrophage polarization and metabolic homeostasis. Nat Commun 2016; 7:12254. [PMID: 27464507 PMCID: PMC4974480 DOI: 10.1038/ncomms12254] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2015] [Accepted: 06/14/2016] [Indexed: 12/27/2022] Open
Abstract
Diet-induced obesity causes chronic macrophage-driven inflammation in white adipose tissue (WAT) leading to insulin resistance. WAT macrophages, however, differ in their origin, gene expression and activities: unlike infiltrating monocyte-derived inflammatory macrophages, WAT-resident macrophages counteract inflammation and insulin resistance, yet, the mechanisms underlying their transcriptional programming remain poorly understood. We recently reported that a nuclear receptor cofactor—glucocorticoid receptor (GR)-interacting protein (GRIP)1—cooperates with GR to repress inflammatory genes. Here, we show that GRIP1 facilitates macrophage programming in response to IL4 via a GR-independent pathway by serving as a coactivator for Kruppel-like factor (KLF)4—a driver of tissue-resident macrophage differentiation. Moreover, obese mice conditionally lacking GRIP1 in macrophages develop massive macrophage infiltration and inflammation in metabolic tissues, fatty livers, hyperglycaemia and insulin resistance recapitulating metabolic disease. Thus, GRIP1 is a critical regulator of immunometabolism, which engages distinct transcriptional mechanisms to coordinate the balance between macrophage populations and ultimately promote metabolic homeostasis. GRIP1 cooperates with the glucocorticoid receptor to repress inflammatory genes. Here the authors show that GRIP1 also controls macrophage polarization, by promoting KLF4-driven activation in response to IL-4, and that mice lacking GRIP1 in macrophages develop severe metabolic dysfunction on a high-fat diet.
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Affiliation(s)
- Maddalena Coppo
- The David Rosensweig Genomics Center, Hospital for Special Surgery, 535 East 70th Street, New York, New York 10021, USA
| | - Yurii Chinenov
- The David Rosensweig Genomics Center, Hospital for Special Surgery, 535 East 70th Street, New York, New York 10021, USA
| | - Maria A Sacta
- Weill Cornell/Rockefeller/Sloan-Kettering Tri-Institutional MD-PhD Program, 1300 York Avenue, New York, New York 10021, USA
| | - Inez Rogatsky
- The David Rosensweig Genomics Center, Hospital for Special Surgery, 535 East 70th Street, New York, New York 10021, USA.,Graduate Program in Immunology and Microbial Pathogenesis, Weill Cornell Graduate School of Medical Sciences, 1300 York Avenue, New York, New York 10021, USA.,Department of Microbiology and Immunology, Weill Medical College of Cornell University, 1300 York Avenue, New York, New York 10021, USA
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Inagaki T, Sakai J, Kajimura S. Transcriptional and epigenetic control of brown and beige adipose cell fate and function. Nat Rev Mol Cell Biol 2016; 17:480-95. [PMID: 27251423 DOI: 10.1038/nrm.2016.62] [Citation(s) in RCA: 222] [Impact Index Per Article: 27.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
White adipocytes store excess energy in the form of triglycerides, whereas brown and beige adipocytes dissipate energy in the form of heat. This thermogenic function relies on the activation of brown and beige adipocyte-specific gene programmes that are coordinately regulated by adipose-selective chromatin architectures and by a set of unique transcriptional and epigenetic regulators. A number of transcriptional and epigenetic regulators are also required for promoting beige adipocyte biogenesis in response to various environmental stimuli. A better understanding of the molecular mechanisms governing the generation and function of brown and beige adipocytes is necessary to allow us to control adipose cell fate and stimulate thermogenesis. This may provide a therapeutic approach for the treatment of obesity and obesity-associated diseases, such as type 2 diabetes.
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Affiliation(s)
- Takeshi Inagaki
- Division of Metabolic Medicine, Research Center for Advanced Science and Technology, The University of Tokyo, Tokyo, Japan 153-8904.,The Translational Systems Biology and Medicine Initiative (TSBMI), Center for Disease Biology and Integrative Medicine, Faculty of Medicine, The University of Tokyo, Tokyo, Japan 113-8655
| | - Juro Sakai
- Division of Metabolic Medicine, Research Center for Advanced Science and Technology, The University of Tokyo, Tokyo, Japan 153-8904.,The Translational Systems Biology and Medicine Initiative (TSBMI), Center for Disease Biology and Integrative Medicine, Faculty of Medicine, The University of Tokyo, Tokyo, Japan 113-8655
| | - Shingo Kajimura
- UCSF Diabetes Center and Department of Cell and Tissue Biology, University of California, San Francisco, California 94143-0669, USA
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The Role of Steroid Receptor Coactivators in Hormone Dependent Cancers and Their Potential as Therapeutic Targets. Discov Oncol 2016; 7:229-35. [PMID: 27125199 DOI: 10.1007/s12672-016-0261-6] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/12/2016] [Accepted: 03/08/2016] [Indexed: 10/21/2022] Open
Abstract
Steroid receptor coactivator (SRC) family members (SRC-1, SRC-2, SRC-3) interact with nuclear receptors (NRs) and many transcription factors to enhance target gene transcription. Deregulation of SRCs is widely implicated in NR mediated diseases, especially hormone dependent cancers. By integrating steroid hormone signaling and growth factor pathways, SRC proteins exert multiple modes of oncogenic regulation in cancers and represent emerging targets for cancer therapeutics. Recent work has identified SRC-targeting agents that show promise in blocking tumor growth in vitro and in vivo, and have the potential to function as powerful and broadly encompassing treatments for different cancers.
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65
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Astapova I. Role of co-regulators in metabolic and transcriptional actions of thyroid hormone. J Mol Endocrinol 2016; 56:73-97. [PMID: 26673411 DOI: 10.1530/jme-15-0246] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/08/2015] [Accepted: 12/16/2015] [Indexed: 12/18/2022]
Abstract
Thyroid hormone (TH) controls a wide range of physiological processes through TH receptor (TR) isoforms. Classically, TRs are proposed to function as tri-iodothyronine (T3)-dependent transcription factors: on positively regulated target genes, unliganded TRs mediate transcriptional repression through recruitment of co-repressor complexes, while T3 binding leads to dismissal of co-repressors and recruitment of co-activators to activate transcription. Co-repressors and co-activators were proposed to play opposite roles in the regulation of negative T3 target genes and hypothalamic-pituitary-thyroid axis, but exact mechanisms of the negative regulation by TH have remained elusive. Important insights into the roles of co-repressors and co-activators in different physiological processes have been obtained using animal models with disrupted co-regulator function. At the same time, recent studies interrogating genome-wide TR binding have generated compelling new data regarding effects of T3, local chromatin structure, and specific response element configuration on TR recruitment and function leading to the proposal of new models of transcriptional regulation by TRs. This review discusses data obtained in various mouse models with manipulated function of nuclear receptor co-repressor (NCoR or NCOR1) and silencing mediator of retinoic acid receptor and thyroid hormone receptor (SMRT or NCOR2), and family of steroid receptor co-activators (SRCs also known as NCOAs) in the context of TH action, as well as insights into the function of co-regulators that may emerge from the genome-wide TR recruitment analysis.
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Affiliation(s)
- Inna Astapova
- Division of Endocrinology, Diabetes and MetabolismBeth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts, USA
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66
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Olokpa E, Bolden A, Stewart LV. The Androgen Receptor Regulates PPARγ Expression and Activity in Human Prostate Cancer Cells. J Cell Physiol 2016; 231:2664-72. [PMID: 26945682 PMCID: PMC5132088 DOI: 10.1002/jcp.25368] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2015] [Accepted: 03/02/2016] [Indexed: 01/22/2023]
Abstract
The peroxisome proliferator activated receptor gamma (PPARγ) is a ligand-activated transcription factor that regulates growth and differentiation within normal prostate and prostate cancers. However the factors that control PPARγ within the prostate cancers have not been characterized. The goal of this study was to examine whether the androgen receptor (AR) regulates PPARγ expression and function within human prostate cancer cells. qRT-PCR and Western blot analyses revealed nanomolar concentrations of the AR agonist dihydrotestosterone (DHT) decrease PPARγ mRNA and protein within the castration-resistant, AR-positive C4-2 and VCaP human prostate cancer cell lines. The AR antagonists bicalutamide and enzalutamide blocked the ability of DHT to reduce PPARγ levels. In addition, siRNA mediated knockdown of AR increased PPARγ protein levels and ligand-induced PPARγ transcriptional activity within the C4-2 cell line. Furthermore, proteasome inhibitors that interfere with AR function increased the level of basal PPARγ and prevented the DHT-mediated suppression of PPARγ. These data suggest that AR normally functions to suppress PPARγ expression within AR-positive prostate cancer cells. To determine whether increases in AR protein would influence PPARγ expression and activity, we used lipofectamine-based transfections to overexpress AR within the AR-null PC-3 cells. The addition of AR to PC-3 cells did not significantly alter PPARγ protein levels. However, the ability of the PPARγ ligand rosiglitazone to induce activation of a PPARγ-driven luciferase reporter and induce expression of FABP4 was suppressed in AR-positive PC-3 cells. Together, these data indicate AR serves as a key modulator of PPARγ expression and function within prostate tumors. J. Cell. Physiol. 231: 2664-2672, 2016. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Emuejevoke Olokpa
- Department of Biochemistry and Cancer BiologyMeharry Medical CollegeNashvilleTennessee
| | - Adrienne Bolden
- Department of Biochemistry and Cancer BiologyMeharry Medical CollegeNashvilleTennessee
| | - LaMonica V. Stewart
- Department of Biochemistry and Cancer BiologyMeharry Medical CollegeNashvilleTennessee
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Madsen A, Bjune JI, Bjørkhaug L, Mellgren G, Sagen JV. The cAMP-dependent protein kinase downregulates glucose-6-phosphatase expression through RORα and SRC-2 coactivator transcriptional activity. Mol Cell Endocrinol 2016; 419:92-101. [PMID: 26455881 DOI: 10.1016/j.mce.2015.10.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/23/2015] [Revised: 09/29/2015] [Accepted: 10/01/2015] [Indexed: 10/22/2022]
Abstract
Fasting hormones activate the cAMP/PKA signaling pathway and stimulate expression of hepatic gluconeogenic enzymes including glucose-6-phosphatase (G6Pase). Previously it was shown that steroid receptor coactivator 2 (SRC-2) knock-out mice exhibit fasting hypoglycemia and that SRC-2 coactivates RAR-related orphan receptor alpha (RORα) at the proximal G6Pase promoter. We have investigated the upstream regulation and functional implications of this RORα/SRC-2 complex on G6Pase expression. In HepG2 cells, overexpression of the catalytic PKA subunit (PKA-Cα) reduced the SRC-2 protein level, recruitment to the G6Pase promoter, and its ability to coactivate RORα. Knock-down and transactivation experiments employing G6Pase promoter constructs demonstrated that RORα and SRC-2 are required for PGC-1α to stimulate G6Pase expression. These results suggest that PKA inhibits SRC-2 coactivation of RORα and in turn reduces PGC-1α dependent regulation of G6Pase. This indirect feedback mechanism may underlie the suppression of gluconeogenesis throughout long-term starvation.
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Affiliation(s)
- Andre Madsen
- Department of Clinical Science K2, University of Bergen, N-5020 Norway; The Hormone Laboratory, Haukeland University Hospital, N-5021 Bergen, Norway.
| | - Jan-Inge Bjune
- Department of Clinical Science K2, University of Bergen, N-5020 Norway; The Hormone Laboratory, Haukeland University Hospital, N-5021 Bergen, Norway.
| | - Lise Bjørkhaug
- The Hormone Laboratory, Haukeland University Hospital, N-5021 Bergen, Norway; KG Jebsen Center for Diabetes Research, University of Bergen, N-5020 Norway; Department of Biomedicine, University of Bergen, N-5020 Norway.
| | - Gunnar Mellgren
- Department of Clinical Science K2, University of Bergen, N-5020 Norway; The Hormone Laboratory, Haukeland University Hospital, N-5021 Bergen, Norway; KG Jebsen Center for Diabetes Research, University of Bergen, N-5020 Norway.
| | - Jørn V Sagen
- Department of Clinical Science K2, University of Bergen, N-5020 Norway; The Hormone Laboratory, Haukeland University Hospital, N-5021 Bergen, Norway; KG Jebsen Center for Diabetes Research, University of Bergen, N-5020 Norway.
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The transcriptional coregulator PGC-1β controls mitochondrial function and anti-oxidant defence in skeletal muscles. Nat Commun 2015; 6:10210. [PMID: 26674215 PMCID: PMC4703903 DOI: 10.1038/ncomms10210] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2015] [Accepted: 11/16/2015] [Indexed: 12/31/2022] Open
Abstract
The transcriptional coregulators PGC-1α and PGC-1β modulate the expression of numerous partially overlapping genes involved in mitochondrial biogenesis and energetic metabolism. The physiological role of PGC-1β is poorly understood in skeletal muscle, a tissue of high mitochondrial content to produce ATP levels required for sustained contractions. Here we determine the physiological role of PGC-1β in skeletal muscle using mice, in which PGC-1β is selectively ablated in skeletal myofibres at adulthood (PGC-1β((i)skm-/-) mice). We show that myofibre myosin heavy chain composition and mitochondrial number, muscle strength and glucose homeostasis are unaffected in PGC-1β((i)skm-/-) mice. However, decreased expression of genes controlling mitochondrial protein import, translational machinery and energy metabolism in PGC-1β((i)skm-/-) muscles leads to mitochondrial structural and functional abnormalities, impaired muscle oxidative capacity and reduced exercise performance. Moreover, enhanced free-radical leak and reduced expression of the mitochondrial anti-oxidant enzyme Sod2 increase muscle oxidative stress. PGC-1β is therefore instrumental for skeletal muscles to cope with high energetic demands.
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69
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Youssef J, Badr M. Peroxisome Proliferator-Activated Receptors Features, Functions, and Future. NUCLEAR RECEPTOR RESEARCH 2015. [DOI: 10.11131/2015/101188] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
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Metformin inhibits hepatocellular glucose, lipid and cholesterol biosynthetic pathways by transcriptionally suppressing steroid receptor coactivator 2 (SRC-2). Sci Rep 2015; 5:16430. [PMID: 26548416 PMCID: PMC4637908 DOI: 10.1038/srep16430] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2015] [Accepted: 10/14/2015] [Indexed: 02/06/2023] Open
Abstract
The ability of the anti-diabetic drug metformin to inhibit anabolic processes including gluconeogenesis and lipogenesis is partly attributable to activation of the AMP-activated protein kinase (AMPK) pathway. The p160 steroid receptor coactivator 2 (SRC-2) is a key regulator of cellular metabolism and drives expression of the gluconeogenic enzyme glucose-6-phosphatase (G6Pc). Here, we uncovered a role for SRC-2 in the metabolic reprogramming imposed by metformin. In FaO cells, metformin dose-dependently reduced mRNA expression of SRC-2. Microarray analysis of metformin-treated cells revealed an overrepresentation of downregulated genes involved in biosynthesis of lipids and cholesterol. Several metformin-regulated genes including fatty acid synthase (FASN) were validated as transcriptional targets of SRC-2 with promoters characterized by sterol regulatory element (SRE) binding protein (SREBP) recognition sequences. Transactivation assays of the FASN promoter confirmed that SRC-2 is a coactivator of SREBP-1. By suppressing SRC-2 at the transcriptional level, metformin impeded recruitment of SRC-2 and RNA polymerase II to the G6Pc promoter and to SREs of mutual SRC-2/SREBP-1 target gene promoters. Hepatocellular fat accretion was reduced by metformin or knock-down of both SRC-2 and SREBP-1. Accordingly we propose that metformin inhibits glucose and lipid biosynthesis partly by downregulating SRC-2 gene expression.
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Fleet T, Zhang B, Lin F, Zhu B, Dasgupta S, Stashi E, Tackett B, Thevananther S, Rajapakshe KI, Gonzales N, Dean A, Mao J, Timchenko N, Malovannaya A, Qin J, Coarfa C, DeMayo F, Dacso CC, Foulds CE, O'Malley BW, York B. SRC-2 orchestrates polygenic inputs for fine-tuning glucose homeostasis. Proc Natl Acad Sci U S A 2015; 112:E6068-77. [PMID: 26487680 PMCID: PMC4640775 DOI: 10.1073/pnas.1519073112] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Despite extensive efforts to understand the monogenic contributions to perturbed glucose homeostasis, the complexity of genetic events that fractionally contribute to the spectrum of this pathology remain poorly understood. Proper maintenance of glucose homeostasis is the central feature of a constellation of comorbidities that define the metabolic syndrome. The ability of the liver to balance carbohydrate uptake and release during the feeding-to-fasting transition is essential to the regulation of peripheral glucose availability. The liver coordinates the expression of gene programs that control glucose absorption, storage, and secretion. Herein, we demonstrate that Steroid Receptor Coactivator 2 (SRC-2) orchestrates a hierarchy of nutritionally responsive transcriptional complexes to precisely modulate plasma glucose availability. Using DNA pull-down technology coupled with mass spectrometry, we have identified SRC-2 as an indispensable integrator of transcriptional complexes that control the rate-limiting steps of hepatic glucose release and accretion. Collectively, these findings position SRC-2 as a major regulator of polygenic inputs to metabolic gene regulation and perhaps identify a previously unappreciated model that helps to explain the clinical spectrum of glucose dysregulation.
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Affiliation(s)
- Tiffany Fleet
- Interdepartmental Department in Translational Biology and Molecular Medicine, Baylor College of Medicine, Houston, TX 77030-3411; Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX 77030-3411
| | - Bin Zhang
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX 77030-3411
| | - Fumin Lin
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX 77030-3411
| | - Bokai Zhu
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX 77030-3411
| | - Subhamoy Dasgupta
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX 77030-3411
| | - Erin Stashi
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX 77030-3411
| | - Bryan Tackett
- Department of Pediatrics, Gastroenterology, Hepatology & Nutrition, Baylor College of Medicine, Houston, TX 77030-3411
| | - Sundararajah Thevananther
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX 77030-3411; Department of Pediatrics, Gastroenterology, Hepatology & Nutrition, Baylor College of Medicine, Houston, TX 77030-3411
| | - Kimal I Rajapakshe
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX 77030-3411
| | - Naomi Gonzales
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX 77030-3411
| | - Adam Dean
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX 77030-3411
| | - Jianqiang Mao
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX 77030-3411
| | - Nikolai Timchenko
- Department of Surgery, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229-3026
| | - Anna Malovannaya
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX 77030-3411; Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX 77030-3411
| | - Jun Qin
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX 77030-3411; Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX 77030-3411
| | - Cristian Coarfa
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX 77030-3411
| | - Francesco DeMayo
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX 77030-3411; Dan L. Duncan Cancer Center, Baylor College of Medicine, Houston, TX 77030-3411
| | - Clifford C Dacso
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX 77030-3411; Department of Medicine, Baylor College of Medicine, Houston, TX 77030-3411
| | - Charles E Foulds
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX 77030-3411
| | - Bert W O'Malley
- Interdepartmental Department in Translational Biology and Molecular Medicine, Baylor College of Medicine, Houston, TX 77030-3411; Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX 77030-3411; Dan L. Duncan Cancer Center, Baylor College of Medicine, Houston, TX 77030-3411;
| | - Brian York
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX 77030-3411; Dan L. Duncan Cancer Center, Baylor College of Medicine, Houston, TX 77030-3411;
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Elattar S, Satyanarayana A. Can Brown Fat Win the Battle Against White Fat? J Cell Physiol 2015; 230:2311-7. [PMID: 25760392 DOI: 10.1002/jcp.24986] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2015] [Accepted: 03/06/2015] [Indexed: 12/31/2022]
Abstract
A rapid growth in the overweight and obese population in the last few decades suggest that the current diet, exercise, awareness or drug strategies are still not effectively restraining the obesity epidemic. Obesity results from increased energy intake, and the body's energy balance shifts towards energy abundance. Therefore, current research is focused on developing new strategies aimed at increasing energy expenditure. As a result, brown adipose tissue (BAT) is receiving tremendous attention since the major function of BAT is to dissipate energy as heat. For example, mouse models that have increased BAT activity or increased numbers of brown-like adipocytes within the white adipose tissue (WAT) are lean and protected from obesity. Alternatively, mouse models that lack BAT activity are more susceptible to age and diet-induced obesity. However, a significant loss of BAT mass during the natural growth process in humans has created enormous challenges in effectively utilizing this tissue to increase energy expenditure. New strategies are primarily focused on expanding the BAT mass and/or activating the existing BAT. In this regard, recent finding that expression of early B cell factor-2 (Ebf2) reprograms the white pre-adipocytes into brown adipocytes is a significant break-through in developing BAT-mediated strategies to treat obesity. Here we review the major biological functions of WAT and BAT, which play critical but opposing roles in the energy spectrum, energy storage versus energy expenditure, and we evaluate whether activation and/or expansion of BAT is practically achievable to treat obesity in humans.
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Affiliation(s)
- Sawsan Elattar
- Department of Biochemistry and Molecular Biology, Molecular Oncology & Biomarkers Program, Georgia Regents University Cancer Center, Georgia Regents University, Room-CN3150, 1410 Laney Walker Blvd., Augusta, Georgia
| | - Ande Satyanarayana
- Department of Biochemistry and Molecular Biology, Molecular Oncology & Biomarkers Program, Georgia Regents University Cancer Center, Georgia Regents University, Room-CN3150, 1410 Laney Walker Blvd., Augusta, Georgia
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Programmed regulation of rat offspring adipogenic transcription factor (PPARγ) by maternal nutrition. J Dev Orig Health Dis 2015; 6:530-8. [PMID: 26286138 DOI: 10.1017/s2040174415001440] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
We determined the protein expression of adipogenic transcription factor, peroxisome proliferator-activated receptor gamma (PPARγ) and its co-repressor and co-activator complexes in adipose tissue from the obese offspring of under- and over-nourished dams. Female rats were fed either a high-fat (60% kcal) or control (10% kcal) diet before mating, and throughout pregnancy and lactation (Mat-OB). Additional dams were 50% food-restricted from pregnancy day 10 to term [intrauterine growth-restricted (IUGR)]. Adipose tissue protein expression was analyzed in newborn and adult male offspring. Normal birth weight Mat-OB and low birth weight IUGR newborns had upregulated PPARγ with variable changes in co-repressors and co-activators. As obese adults, Mat-OB and IUGR offspring had increased PPARγ with decreased co-repressor and increased co-activator expression. Nutritionally programmed increased PPARγ expression is associated with altered expression of its co-regulators in the newborn and adult offspring. Functional studies of PPARγ co-regulators are necessary to establish their role in PPARγ-mediated programmed obesity.
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Of mice and men: novel insights regarding constitutive and recruitable brown adipocytes. INTERNATIONAL JOURNAL OF OBESITY SUPPLEMENTS 2015; 5:S15-20. [PMID: 27152169 DOI: 10.1038/ijosup.2015.5] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/31/2013] [Accepted: 02/12/2015] [Indexed: 01/02/2023]
Abstract
Recently, there has been great attention given to the possibility of combating obesity by targeting brown fat activity or increasing differentiation of brown adipocytes in white fat depots through a process termed 'browning'. Sympathetic innervation of brown and white adipose tissues provides adrenergic input that drives thermogenesis and regulates fatty acid metabolism, as well as stimulating adipogenesis of recruitable brown adipocyte tissue (rBAT, also known as beige or brite) in white fat. Other factors acting in an endocrine or autocrine/paracrine manner in adipose tissue may also stimulate browning. There have been significant recent advances in understanding the mechanisms of increasing adipose tissue energy expenditure, as well as how brown adipocytes appear in white fat depots, including via de novo adipogenesis from tissue precursor cells. In this article, we integrate this new knowledge with a historical perspective on the discovery of 'browning'. We also provide an overview of constitutive BAT vs rBAT in mouse and human.
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Vaitkus JA, Farrar JS, Celi FS. Thyroid Hormone Mediated Modulation of Energy Expenditure. Int J Mol Sci 2015; 16:16158-75. [PMID: 26193258 PMCID: PMC4519944 DOI: 10.3390/ijms160716158] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2015] [Revised: 07/07/2015] [Accepted: 07/09/2015] [Indexed: 01/15/2023] Open
Abstract
Thyroid hormone (TH) has diverse effects on mitochondria and energy expenditure (EE), generating great interest and research effort into understanding and harnessing these actions for the amelioration and treatment of metabolic disorders, such as obesity and diabetes. Direct effects on ATP utilization are a result of TH's actions on metabolic cycles and increased cell membrane ion permeability. However, the majority of TH induced EE is thought to be a result of indirect effects, which, in turn, increase capacity for EE. This review discusses the direct actions of TH on EE, and places special emphasis on the indirect actions of TH, which include mitochondrial biogenesis and reduced metabolic efficiency through mitochondrial uncoupling mechanisms. TH analogs and the metabolic actions of T2 are also discussed in the context of targeted modulation of EE. Finally, clinical correlates of TH actions on metabolism are briefly presented.
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Affiliation(s)
- Janina A Vaitkus
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Virginia Commonwealth University School of Medicine, Richmond, VA 23298, USA.
| | - Jared S Farrar
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Virginia Commonwealth University School of Medicine, Richmond, VA 23298, USA.
| | - Francesco S Celi
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Virginia Commonwealth University School of Medicine, Richmond, VA 23298, USA.
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Bozickovic O, Hoang T, Fenne IS, Helland T, Skartveit L, Ouchida M, Mellgren G, Sagen JV. Cyclin C interacts with steroid receptor coactivator 2 and upregulates cell cycle genes in MCF-7 cells. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2015; 1853:2383-91. [PMID: 25986860 DOI: 10.1016/j.bbamcr.2015.05.016] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2015] [Revised: 04/23/2015] [Accepted: 05/09/2015] [Indexed: 11/16/2022]
Abstract
Steroid receptor coactivator 2 (SRC-2) is a coactivator that regulates nuclear receptor activity. We previously reported that SRC-2 protein is degraded through the action of cAMP-dependent protein kinase A (PKA) and cAMP response element binding protein (CREB). In the study presented here, we aimed to identify proteins that interact with and thereby regulate SRC-2. We isolated cyclin C (CCNC) as an interacting partner with the SRC-2 degradation domain aa 347-758 in a yeast two-hybrid assay and confirmed direct interaction in an in vitro assay. The protein level of SRC-2 was increased with CCNC overexpression in COS-1 cells and decreased with CCNC silencing in COS-1 and MCF-7 cells. In a pulse-chase assay, we further show that silencing of CCNC resulted in a different SRC-2 degradation pattern during the first 6 h after the pulse. Finally, we provide evidence that CCNC regulates expression of cell cycle genes upregulated by SRC-2. In conclusion, our results suggest that CCNC temporarily protects SRC-2 against degradation and this event is involved in the transcriptional regulation of SRC-2 cell cycle target genes.
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Affiliation(s)
- Olivera Bozickovic
- Department of Clinical Science, University of Bergen, Bergen N-5021, Norway; Hormone Laboratory, Haukeland University Hospital, Bergen N-5021, Norway.
| | - Tuyen Hoang
- Department of Clinical Science, University of Bergen, Bergen N-5021, Norway.
| | - Ingvild S Fenne
- Department of Clinical Science, University of Bergen, Bergen N-5021, Norway; Hormone Laboratory, Haukeland University Hospital, Bergen N-5021, Norway.
| | - Thomas Helland
- Department of Clinical Science, University of Bergen, Bergen N-5021, Norway; Hormone Laboratory, Haukeland University Hospital, Bergen N-5021, Norway.
| | - Linn Skartveit
- Department of Clinical Science, University of Bergen, Bergen N-5021, Norway; Hormone Laboratory, Haukeland University Hospital, Bergen N-5021, Norway.
| | - Mamoru Ouchida
- Department of Molecular Genetics, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan.
| | - Gunnar Mellgren
- Department of Clinical Science, University of Bergen, Bergen N-5021, Norway; Hormone Laboratory, Haukeland University Hospital, Bergen N-5021, Norway.
| | - Jørn V Sagen
- Department of Clinical Science, University of Bergen, Bergen N-5021, Norway; Hormone Laboratory, Haukeland University Hospital, Bergen N-5021, Norway.
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Poitou C, Perret C, Mathieu F, Truong V, Blum Y, Durand H, Alili R, Chelghoum N, Pelloux V, Aron-Wisnewsky J, Torcivia A, Bouillot JL, Parks BW, Ninio E, Clément K, Tiret L. Bariatric Surgery Induces Disruption in Inflammatory Signaling Pathways Mediated by Immune Cells in Adipose Tissue: A RNA-Seq Study. PLoS One 2015; 10:e0125718. [PMID: 25938420 PMCID: PMC4418598 DOI: 10.1371/journal.pone.0125718] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2014] [Accepted: 03/17/2015] [Indexed: 11/30/2022] Open
Abstract
Background Bariatric surgery is associated to improvements in obesity-associated comorbidities thought to be mediated by a decrease of adipose inflammation. However, the molecular mechanisms behind these beneficial effects are poorly understood. Methodology/Principal Findings We analyzed RNA-seq expression profiles in adipose tissue from 22 obese women before and 3 months after surgery. Of 15,972 detected genes, 1214 were differentially expressed after surgery at a 5% false discovery rate. Upregulated genes were mostly involved in the basal cellular machinery. Downregulated genes were enriched in metabolic functions of adipose tissue. At baseline, 26 modules of coexpressed genes were identified. The four most stable modules reflected the innate and adaptive immune responses of adipose tissue. A first module reflecting a non-specific signature of innate immune cells, mainly macrophages, was highly conserved after surgery with the exception of DUSP2 and CD300C. A second module reflected the adaptive immune response elicited by T lymphocytes; after surgery, a disconnection was observed between genes involved in T-cell signaling and mediators of the signal transduction such as CXCR1, CXCR2, GPR97, CCR7 and IL7R. A third module reflected neutrophil-mediated inflammation; after surgery, several genes were dissociated from the module, including S100A8, S100A12, CD300E, VNN2, TUBB1 and FAM65B. We also identified a dense network of 19 genes involved in the interferon-signaling pathway which was strongly preserved after surgery, with the exception of DDX60, an antiviral factor involved in RIG-I-mediated interferon signaling. A similar loss of connection was observed in lean mice compared to their obese counterparts. Conclusions/Significance These results suggest that improvements of the inflammatory state following surgery might be explained by a disruption of immuno-inflammatory cascades involving a few crucial molecules which could serve as potential therapeutic targets.
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Affiliation(s)
- Christine Poitou
- Institute of Cardiometabolism And Nutrition (ICAN), Assistance Publique-Hôpitaux de Paris, Pitié-Salpêtrière Hospital, Nutrition Department, F-75013, Paris, France
- Sorbonne Universités, University Pierre et Marie Curie (UPMC), Institut National de la Santé et de la Recherche Médicale (INSERM) UMR_S 1166, Nutriomics team, F-75005, Paris, France
| | - Claire Perret
- Institute of Cardiometabolism And Nutrition (ICAN), Assistance Publique-Hôpitaux de Paris, Pitié-Salpêtrière Hospital, Nutrition Department, F-75013, Paris, France
- Sorbonne Universités, University Pierre et Marie Curie (UPMC), Institut National de la Santé et de la Recherche Médicale (INSERM) UMR_S 1166, Genomics and Pathophysiology of Cardiovascular Diseases team, F-75013, Paris, France
| | - François Mathieu
- Institute of Cardiometabolism And Nutrition (ICAN), Assistance Publique-Hôpitaux de Paris, Pitié-Salpêtrière Hospital, Nutrition Department, F-75013, Paris, France
- Sorbonne Universités, University Pierre et Marie Curie (UPMC), Institut National de la Santé et de la Recherche Médicale (INSERM) UMR_S 1166, Genomics and Pathophysiology of Cardiovascular Diseases team, F-75013, Paris, France
| | - Vinh Truong
- Institute of Cardiometabolism And Nutrition (ICAN), Assistance Publique-Hôpitaux de Paris, Pitié-Salpêtrière Hospital, Nutrition Department, F-75013, Paris, France
- Sorbonne Universités, University Pierre et Marie Curie (UPMC), Institut National de la Santé et de la Recherche Médicale (INSERM) UMR_S 1166, Genomics and Pathophysiology of Cardiovascular Diseases team, F-75013, Paris, France
| | - Yuna Blum
- Department of Medicine/Division of Cardiology, University of California Los Angeles, Los Angeles, California 90095, United States of America
| | - Hervé Durand
- Institute of Cardiometabolism And Nutrition (ICAN), Assistance Publique-Hôpitaux de Paris, Pitié-Salpêtrière Hospital, Nutrition Department, F-75013, Paris, France
- Sorbonne Universités, University Pierre et Marie Curie (UPMC), Institut National de la Santé et de la Recherche Médicale (INSERM) UMR_S 1166, Genomics and Pathophysiology of Cardiovascular Diseases team, F-75013, Paris, France
| | - Rohia Alili
- Institute of Cardiometabolism And Nutrition (ICAN), Assistance Publique-Hôpitaux de Paris, Pitié-Salpêtrière Hospital, Nutrition Department, F-75013, Paris, France
- Sorbonne Universités, University Pierre et Marie Curie (UPMC), Institut National de la Santé et de la Recherche Médicale (INSERM) UMR_S 1166, Nutriomics team, F-75005, Paris, France
| | - Nadjim Chelghoum
- Sorbonne Universités, University Pierre et Marie Curie (UPMC), Post-Genomic Platform of Pitié-Salpêtrière (P3S), F-75013, Paris, France
| | - Véronique Pelloux
- Institute of Cardiometabolism And Nutrition (ICAN), Assistance Publique-Hôpitaux de Paris, Pitié-Salpêtrière Hospital, Nutrition Department, F-75013, Paris, France
- Sorbonne Universités, University Pierre et Marie Curie (UPMC), Institut National de la Santé et de la Recherche Médicale (INSERM) UMR_S 1166, Nutriomics team, F-75005, Paris, France
| | - Judith Aron-Wisnewsky
- Institute of Cardiometabolism And Nutrition (ICAN), Assistance Publique-Hôpitaux de Paris, Pitié-Salpêtrière Hospital, Nutrition Department, F-75013, Paris, France
- Sorbonne Universités, University Pierre et Marie Curie (UPMC), Institut National de la Santé et de la Recherche Médicale (INSERM) UMR_S 1166, Nutriomics team, F-75005, Paris, France
| | - Adriana Torcivia
- Assistance Publique-Hôpitaux de Paris, Department of Visceral Surgery, Pitié-Salpêtrière Hospital, F-75013, Paris, France
| | - Jean-Luc Bouillot
- Assistance Publique-Hôpitaux de Paris, Department of General, Digestive and Metabolic Surgery, Ambroise-Paré Hospital, F- 92100, Boulogne-Billancourt, France
| | - Brian W. Parks
- Department of Medicine/Division of Cardiology, University of California Los Angeles, Los Angeles, California 90095, United States of America
| | - Ewa Ninio
- Institute of Cardiometabolism And Nutrition (ICAN), Assistance Publique-Hôpitaux de Paris, Pitié-Salpêtrière Hospital, Nutrition Department, F-75013, Paris, France
- Sorbonne Universités, University Pierre et Marie Curie (UPMC), Institut National de la Santé et de la Recherche Médicale (INSERM) UMR_S 1166, Genomics and Pathophysiology of Cardiovascular Diseases team, F-75013, Paris, France
| | - Karine Clément
- Institute of Cardiometabolism And Nutrition (ICAN), Assistance Publique-Hôpitaux de Paris, Pitié-Salpêtrière Hospital, Nutrition Department, F-75013, Paris, France
- Sorbonne Universités, University Pierre et Marie Curie (UPMC), Institut National de la Santé et de la Recherche Médicale (INSERM) UMR_S 1166, Nutriomics team, F-75005, Paris, France
| | - Laurence Tiret
- Institute of Cardiometabolism And Nutrition (ICAN), Assistance Publique-Hôpitaux de Paris, Pitié-Salpêtrière Hospital, Nutrition Department, F-75013, Paris, France
- Sorbonne Universités, University Pierre et Marie Curie (UPMC), Institut National de la Santé et de la Recherche Médicale (INSERM) UMR_S 1166, Genomics and Pathophysiology of Cardiovascular Diseases team, F-75013, Paris, France
- * E-mail:
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Roman S, Agil A, Peran M, Alvaro-Galue E, Ruiz-Ojeda FJ, Fernández-Vázquez G, Marchal JA. Brown adipose tissue and novel therapeutic approaches to treat metabolic disorders. Transl Res 2015; 165:464-79. [PMID: 25433289 DOI: 10.1016/j.trsl.2014.11.002] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/11/2014] [Revised: 10/16/2014] [Accepted: 11/04/2014] [Indexed: 01/08/2023]
Abstract
In humans, 2 functionally different types of adipose tissue coexist: white adipose tissue (WAT) and brown adipose tissue (BAT). WAT is involved in energy storage, whereas BAT is involved in energy expenditure. Increased amounts of WAT may contribute to the development of metabolic disorders, such as obesity-associated type 2 diabetes mellitus and cardiovascular diseases. In contrast, the thermogenic function of BAT allows high consumption of fatty acids because of the activity of uncoupling protein 1 in the internal mitochondrial membrane. Interestingly, obesity reduction and insulin sensitization have been achieved by BAT activation-regeneration in animal models. This review describes the origin, function, and differentiation mechanisms of BAT to identify new therapeutic strategies for the treatment of metabolic disorders related to obesity. On the basis of the animal studies, novel approaches for BAT regeneration combining stem cells from the adipose tissue with active components, such as melatonin, may have potential for the treatment of metabolic disorders in humans.
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Affiliation(s)
- Sabiniano Roman
- Biopathology and Regenerative Medicine Institute (IBIMER), Centre for Biomedical Research, University of Granada, Granada, Spain; Tissue Engineering Group, Kroto Research Institute, University of Sheffield, Sheffield, UK
| | - Ahmad Agil
- Department of Pharmacology and Neurosciences Institute, Faculty of Medicine, Biosanitary Institute of Granada (ibs.GRANADA), Hospitals Unversity/University of Granada, Granada, Spain
| | - Macarena Peran
- Biopathology and Regenerative Medicine Institute (IBIMER), Centre for Biomedical Research, University of Granada, Granada, Spain; Department of Health Sciences, University of Jaén, Jaén, Spain
| | - Eduardo Alvaro-Galue
- Biopathology and Regenerative Medicine Institute (IBIMER), Centre for Biomedical Research, University of Granada, Granada, Spain; Wake Forest Institute for Regenerative Medicine Wake Forest School of Medicine, Winston Salem, NC
| | - Francisco J Ruiz-Ojeda
- Institute of Nutrition and Food Technology, Centre for Biomedical Research, University of Granada, Granada, Spain
| | | | - Juan A Marchal
- Biopathology and Regenerative Medicine Institute (IBIMER), Centre for Biomedical Research, University of Granada, Granada, Spain; Department of Human Anatomy and Embryology, Biosanitary Institute of Granada (ibs.GRANADA), Hospitals Unversity/University of Granada, Granada, Spain.
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79
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Basse AL, Dixen K, Yadav R, Tygesen MP, Qvortrup K, Kristiansen K, Quistorff B, Gupta R, Wang J, Hansen JB. Global gene expression profiling of brown to white adipose tissue transformation in sheep reveals novel transcriptional components linked to adipose remodeling. BMC Genomics 2015; 16:215. [PMID: 25887780 PMCID: PMC4407871 DOI: 10.1186/s12864-015-1405-8] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2014] [Accepted: 02/26/2015] [Indexed: 11/30/2022] Open
Abstract
BACKGROUND Large mammals are capable of thermoregulation shortly after birth due to the presence of brown adipose tissue (BAT). The majority of BAT disappears after birth and is replaced by white adipose tissue (WAT). RESULTS We analyzed the postnatal transformation of adipose in sheep with a time course study of the perirenal adipose depot. We observed changes in tissue morphology, gene expression and metabolism within the first two weeks of postnatal life consistent with the expected transition from BAT to WAT. The transformation was characterized by massively decreased mitochondrial abundance and down-regulation of gene expression related to mitochondrial function and oxidative phosphorylation. Global gene expression profiling demonstrated that the time points grouped into three phases: a brown adipose phase, a transition phase and a white adipose phase. Between the brown adipose and the transition phase 170 genes were differentially expressed, and 717 genes were differentially expressed between the transition and the white adipose phase. Thirty-eight genes were shared among the two sets of differentially expressed genes. We identified a number of regulated transcription factors, including NR1H3, MYC, KLF4, ESR1, RELA and BCL6, which were linked to the overall changes in gene expression during the adipose tissue remodeling. Finally, the perirenal adipose tissue expressed both brown and brite/beige adipocyte marker genes at birth, the expression of which changed substantially over time. CONCLUSIONS Using global gene expression profiling of the postnatal BAT to WAT transformation in sheep, we provide novel insight into adipose tissue plasticity in a large mammal, including identification of novel transcriptional components linked to adipose tissue remodeling. Moreover, our data set provides a useful resource for further studies in adipose tissue plasticity.
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Affiliation(s)
- Astrid L Basse
- Department of Biomedical Sciences, University of Copenhagen, DK-2200, Copenhagen, Denmark.
- Department of Systems Biology, Center for Biological Sequence Analysis, Technical University of Denmark, DK-2800, Kongens Lyngby, Denmark.
| | - Karen Dixen
- Department of Biomedical Sciences, University of Copenhagen, DK-2200, Copenhagen, Denmark.
- Department of Systems Biology, Center for Biological Sequence Analysis, Technical University of Denmark, DK-2800, Kongens Lyngby, Denmark.
| | - Rachita Yadav
- Department of Biology, University of Copenhagen, DK-2100, Copenhagen, Denmark.
- Department of Systems Biology, Center for Biological Sequence Analysis, Technical University of Denmark, DK-2800, Kongens Lyngby, Denmark.
| | - Malin P Tygesen
- Department of Veterinary Clinical and Animal Sciences, University of Copenhagen, DK-1870, Frederiksberg, Denmark.
| | - Klaus Qvortrup
- Department of Biomedical Sciences, University of Copenhagen, DK-2200, Copenhagen, Denmark.
| | - Karsten Kristiansen
- Department of Systems Biology, Center for Biological Sequence Analysis, Technical University of Denmark, DK-2800, Kongens Lyngby, Denmark.
| | - Bjørn Quistorff
- Department of Biomedical Sciences, University of Copenhagen, DK-2200, Copenhagen, Denmark.
| | - Ramneek Gupta
- Department of Biology, University of Copenhagen, DK-2100, Copenhagen, Denmark.
| | - Jun Wang
- Department of Systems Biology, Center for Biological Sequence Analysis, Technical University of Denmark, DK-2800, Kongens Lyngby, Denmark.
- BGI-Shenzhen, Shenzhen, 518083, China.
- Princess Al Jawhara Center of Excellence in the Research of Hereditary Disorders, King Abdulaziz University, Jeddah, 21589, Saudi Arabia.
- Macau University of Science and Technology, Avenida Wai Long, Taipa, Macau, 999078, China.
| | - Jacob B Hansen
- Department of Systems Biology, Center for Biological Sequence Analysis, Technical University of Denmark, DK-2800, Kongens Lyngby, Denmark.
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80
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Zeng HL, Huang SL, Xie FC, Zeng LM, Hu YH, Leng Y. Yhhu981, a novel compound, stimulates fatty acid oxidation via the activation of AMPK and ameliorates lipid metabolism disorder in ob/ob mice. Acta Pharmacol Sin 2015; 36:343-52. [PMID: 25732571 DOI: 10.1038/aps.2014.147] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2014] [Accepted: 12/08/2014] [Indexed: 02/07/2023] Open
Abstract
AIM Defects in fatty acid metabolism contribute to the pathogenesis of insulin resistance and obesity. In this study, we investigated the effects of a novel compound yhhu981 on fatty acid metabolism in vitro and in vivo. METHODS The capacity to stimulate fatty acid oxidation was assessed in C2C12 myotubes. The fatty acid synthesis was studied in HepG2 cells using isotope tracing. The phosphorylation of AMPK and acetyl-CoA carboxylase (ACC) was examined with Western blot analysis. For in vivo experiments, ob/ob mice were orally treated with yhhu981 acutely (300 mg/kg) or chronically (150 or 300 mg·kg(-1)·d(-1) for 22 d). On the last day of treatment, serum and tissue samples were collected for analysis. RESULTS Yhhu981 (12.5-25 μmol/L) significantly increased fatty acid oxidation and the expression of related genes (Sirt1, Pgc1α and Mcad) in C2C12 myotubes, and inhibited fatty acid synthesis in HepG2 cells. Furthermore, yhhu981 dose-dependently increased the phosphorylation of AMPK and ACC in both C2C12 myotubes and HepG2 cells. Compound C, an AMPK inhibitor, blocked fatty acid oxidation in yhhu981-treated C2C12 myotubes and fatty acid synthesis decrease in yhhu981-treated HepG2 cells. Acute administration of yhhu981 decreased the respiratory exchange ratio in ob/ob mice, whereas chronic treatment with yhhu981 ameliorated the lipid abnormalities and ectopic lipid deposition in skeletal muscle and liver of ob/ob mice. CONCLUSION Yhhu981 is a potent compound that stimulates fatty acid oxidation, and exerts pleiotropic effects on lipid metabolism by activating AMPK.
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81
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Dasgupta S, Putluri N, Long W, Zhang B, Wang J, Kaushik AK, Arnold JM, Bhowmik SK, Stashi E, Brennan CA, Rajapakshe K, Coarfa C, Mitsiades N, Ittmann MM, Chinnaiyan AM, Sreekumar A, O'Malley BW. Coactivator SRC-2-dependent metabolic reprogramming mediates prostate cancer survival and metastasis. J Clin Invest 2015; 125:1174-88. [PMID: 25664849 DOI: 10.1172/jci76029] [Citation(s) in RCA: 69] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2014] [Accepted: 01/02/2015] [Indexed: 12/19/2022] Open
Abstract
Metabolic pathway reprogramming is a hallmark of cancer cell growth and survival and supports the anabolic and energetic demands of these rapidly dividing cells. The underlying regulators of the tumor metabolic program are not completely understood; however, these factors have potential as cancer therapy targets. Here, we determined that upregulation of the oncogenic transcriptional coregulator steroid receptor coactivator 2 (SRC-2), also known as NCOA2, drives glutamine-dependent de novo lipogenesis, which supports tumor cell survival and eventual metastasis. SRC-2 was highly elevated in a variety of tumors, especially in prostate cancer, in which SRC-2 was amplified and overexpressed in 37% of the metastatic tumors evaluated. In prostate cancer cells, SRC-2 stimulated reductive carboxylation of α-ketoglutarate to generate citrate via retrograde TCA cycling, promoting lipogenesis and reprogramming of glutamine metabolism. Glutamine-mediated nutrient signaling activated SRC-2 via mTORC1-dependent phosphorylation, which then triggered downstream transcriptional responses by coactivating SREBP-1, which subsequently enhanced lipogenic enzyme expression. Metabolic profiling of human prostate tumors identified a massive increase in the SRC-2-driven metabolic signature in metastatic tumors compared with that seen in localized tumors, further implicating SRC-2 as a prominent metabolic coordinator of cancer metastasis. Moreover, SRC-2 inhibition in murine models severely attenuated the survival, growth, and metastasis of prostate cancer. Together, these results suggest that the SRC-2 pathway has potential as a therapeutic target for prostate cancer.
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82
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Rollins DA, Coppo M, Rogatsky I. Minireview: nuclear receptor coregulators of the p160 family: insights into inflammation and metabolism. Mol Endocrinol 2015; 29:502-17. [PMID: 25647480 DOI: 10.1210/me.2015-1005] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Nuclear receptor coactivators (NCOAs) are multifunctional transcriptional coregulators for a growing number of signal-activated transcription factors. The members of the p160 family (NCOA1/2/3) are increasingly recognized as essential and nonredundant players in a number of physiological processes. In particular, accumulating evidence points to the pivotal roles that these coregulators play in inflammatory and metabolic pathways, both under homeostasis and in disease. Given that chronic inflammation of metabolic tissues ("metainflammation") is a driving force for the widespread epidemic of obesity, insulin resistance, cardiovascular disease, and associated comorbidities, deciphering the role of NCOAs in "normal" vs "pathological" inflammation and in metabolic processes is indeed a subject of extreme biomedical importance. Here, we review the evolving and, at times, contradictory, literature on the pleiotropic functions of NCOA1/2/3 in inflammation and metabolism as related to nuclear receptor actions and beyond. We then briefly discuss the potential utility of NCOAs as predictive markers for disease and/or possible therapeutic targets once a better understanding of their molecular and physiological actions is achieved.
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Affiliation(s)
- David A Rollins
- Hospital for Special Surgery (D.A.R., M.C., I.R.), The David Rosensweig Genomics Center, New York, New York 10021; and Graduate Program in Immunology and Microbial Pathogenesis (D.A.R., I.R.), Weill Cornell Graduate School of Medical Sciences, New York, New York 10021
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83
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Xiang X, Lan H, Tang H, Yuan F, Xu Y, Zhao J, Li Y, Zhang W. Tuberous sclerosis complex 1-mechanistic target of rapamycin complex 1 signaling determines brown-to-white adipocyte phenotypic switch. Diabetes 2015; 64:519-28. [PMID: 25213336 DOI: 10.2337/db14-0427] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Interconversion of white and brown adipocytes occurs between anabolic and catabolic states. The molecular mechanism regulating this phenotypic switch remains largely unknown. This study explores the role of tuberous sclerosis complex 1 (TSC1)-mechanistic target of rapamycin (mTOR) signaling in the conversion of brown to white adipose tissue (WAT). A colony of Fabp4-Tsc1(-/-) mice, in which the Tsc1 gene was specifically deleted by the fatty acid binding protein 4 (FABP4)-Cre, was established. Western blotting and immunostaining demonstrated the absence of TSC1 and activation of ribosomal protein S6 kinase 1, the downstream target of mTOR complex 1 (mTORC1) signaling, in the brown adipose tissues (BATs) of Fabp4-Tsc1(-/-) mice. Accumulation of lipid droplets in BAT was significantly increased. Levels of brown adipocyte markers were markedly downregulated, while white adipocyte markers were upregulated. Rapamycin reversed the conversion from BAT to WAT in Fabp4-Tsc1(-/-) mice. Deletion of the Tsc1 gene in cultured brown preadipocytes significantly increased the conversion to white adipocytes. FoxC2 mRNA, the transcriptional factor for brown adipocyte determination, was significantly decreased, while mRNAs for retinoblastoma protein, p107 and RIP140, the transcriptional factors for white adipocyte determination, increased in the BAT of Fabp4-Tsc1(-/-) mice. Our study demonstrates that TSC1-mTORC1 signaling contributes to the brown-to-white adipocyte phenotypic switch.
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Affiliation(s)
- Xinxin Xiang
- Department of Physiology and Pathophysiology, Peking University Health Science Center, Beijing, China Key Laboratory of Molecular Cardiovascular Science, Ministry of Education, Beijing, China Department of Pathology, Central Hospital of Zibo, Zibo, China
| | - He Lan
- Department of Physiology and Pathophysiology, Peking University Health Science Center, Beijing, China Key Laboratory of Molecular Cardiovascular Science, Ministry of Education, Beijing, China
| | - Hong Tang
- Department of Physiology and Pathophysiology, Peking University Health Science Center, Beijing, China Key Laboratory of Molecular Cardiovascular Science, Ministry of Education, Beijing, China
| | - Fang Yuan
- Department of Physiology and Pathophysiology, Peking University Health Science Center, Beijing, China Key Laboratory of Molecular Cardiovascular Science, Ministry of Education, Beijing, China
| | - Yanhui Xu
- Department of Physiology and Pathophysiology, Peking University Health Science Center, Beijing, China Key Laboratory of Molecular Cardiovascular Science, Ministry of Education, Beijing, China
| | - Jing Zhao
- Department of Physiology and Pathophysiology, Peking University Health Science Center, Beijing, China Key Laboratory of Molecular Cardiovascular Science, Ministry of Education, Beijing, China
| | - Yin Li
- Department of Physiology and Pathophysiology, Peking University Health Science Center, Beijing, China Key Laboratory of Molecular Cardiovascular Science, Ministry of Education, Beijing, China
| | - Weizhen Zhang
- Department of Physiology and Pathophysiology, Peking University Health Science Center, Beijing, China Key Laboratory of Molecular Cardiovascular Science, Ministry of Education, Beijing, China Department of Surgery, University of Michigan, Ann Arbor, MI
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84
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Choi JS, Choi SS, Kim ES, Seo YK, Seo JK, Kim EK, Suh PG, Choi JH. Flightless-1, a novel transcriptional modulator of PPARγ through competing with RXRα. Cell Signal 2014; 27:614-20. [PMID: 25479590 DOI: 10.1016/j.cellsig.2014.11.035] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2014] [Revised: 11/24/2014] [Accepted: 11/27/2014] [Indexed: 02/07/2023]
Abstract
Peroxisome proliferator-activated receptor γ (PPARγ) is a member of the nuclear receptor family and plays key roles in glucose and lipid metabolism. Its transcriptional control of target genes is mediated by ligand-dependent recruitment of coactivators. In this study, we demonstrate that a novel transcriptional modulator of PPARγ, Flightless-I (FLII) binds directly to and suppresses the transcriptional activity of PPARγ. The LXXLL motif within the leucine-rich repeat (LRR) domain of FLII interacts directly with the DNA-binding domain of PPARγ. Interestingly, in the presence of PPARγ ligands, such as rosiglitazone and SR1664, this interaction was abolished in vitro. When FLII was overexpressed, both the transcriptional activity of PPARγ and adipogenesis were suppressed significantly, whereas specific knockdown of FLII reversed these effects. Furthermore, DNA occupancy of PPARγ on its target gene promoters was enhanced by FLII knockdown, and the interaction between PPARγ and retinoid X receptor α (RXRα) was blocked by FLII. Together, these findings strongly suggest that FLII functions in PPARγ activation as a molecular switch to repress transcriptional activity by interrupting formation of the PPARγ/RXRα complex, and FLII may serve as a novel therapeutic target in the treatment of adiposity-related metabolic syndromes.
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Affiliation(s)
- Jin Sil Choi
- Department of Biological Sciences, Ulsan National Institute of Science and Technology (UNIST), Ulsan 689-798, Republic of Korea
| | - Sun-Sil Choi
- Department of Biological Sciences, Ulsan National Institute of Science and Technology (UNIST), Ulsan 689-798, Republic of Korea
| | - Eun Sun Kim
- Department of Biological Sciences, Ulsan National Institute of Science and Technology (UNIST), Ulsan 689-798, Republic of Korea
| | - Young-Kyo Seo
- Department of Biological Sciences, Ulsan National Institute of Science and Technology (UNIST), Ulsan 689-798, Republic of Korea
| | - Jeong Kon Seo
- UNIST Central Research Facilities, Ulsan National Institute of Science and Technology (UNIST), Ulsan 689-798, Republic of Korea
| | - Eung-Kyun Kim
- Department of Biological Sciences, Ulsan National Institute of Science and Technology (UNIST), Ulsan 689-798, Republic of Korea
| | - Pann-Ghill Suh
- Department of Biological Sciences, Ulsan National Institute of Science and Technology (UNIST), Ulsan 689-798, Republic of Korea
| | - Jang Hyun Choi
- Department of Biological Sciences, Ulsan National Institute of Science and Technology (UNIST), Ulsan 689-798, Republic of Korea.
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85
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Wright MB, Bortolini M, Tadayyon M, Bopst M. Minireview: Challenges and opportunities in development of PPAR agonists. Mol Endocrinol 2014; 28:1756-68. [PMID: 25148456 PMCID: PMC5414793 DOI: 10.1210/me.2013-1427] [Citation(s) in RCA: 116] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2013] [Accepted: 08/08/2014] [Indexed: 01/06/2023] Open
Abstract
The clinical impact of the fibrate and thiazolidinedione drugs on dyslipidemia and diabetes is driven mainly through activation of two transcription factors, peroxisome proliferator-activated receptors (PPAR)-α and PPAR-γ. However, substantial differences exist in the therapeutic and side-effect profiles of specific drugs. This has been attributed primarily to the complexity of drug-target complexes that involve many coregulatory proteins in the context of specific target gene promoters. Recent data have revealed that some PPAR ligands interact with other non-PPAR targets. Here we review concepts used to develop new agents that preferentially modulate transcriptional complex assembly, target more than one PPAR receptor simultaneously, or act as partial agonists. We highlight newly described on-target mechanisms of PPAR regulation including phosphorylation and nongenomic regulation. We briefly describe the recently discovered non-PPAR protein targets of thiazolidinediones, mitoNEET, and mTOT. Finally, we summarize the contributions of on- and off-target actions to select therapeutic and side effects of PPAR ligands including insulin sensitivity, cardiovascular actions, inflammation, and carcinogenicity.
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Affiliation(s)
- Matthew B Wright
- F. Hoffmann-La Roche Pharmaceuticals (M.B.W., M.Bor., M.Bop.), CH-4070 Basel, Switzerland; and MediTech Media (M.T.), London EC1V 9AZ, United Kingdom
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86
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Cantley JL, Vatner DF, Galbo T, Madiraju A, Petersen M, Perry RJ, Kumashiro N, Guebre-Egziabher F, Gattu AK, Stacy MR, Dione DP, Sinusas AJ, Ragolia L, Hall CE, Manchem VP, Bhanot S, Bogan JS, Samuel VT. Targeting steroid receptor coactivator 1 with antisense oligonucleotides increases insulin-stimulated skeletal muscle glucose uptake in chow-fed and high-fat-fed male rats. Am J Physiol Endocrinol Metab 2014; 307:E773-83. [PMID: 25159329 PMCID: PMC4216948 DOI: 10.1152/ajpendo.00148.2014] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The steroid receptor coactivator 1 (SRC1) regulates key metabolic pathways, including glucose homeostasis. SRC1(-/-) mice have decreased hepatic expression of gluconeogenic enzymes and a reduction in the rate of endogenous glucose production (EGP). We sought to determine whether decreasing hepatic and adipose SRC1 expression in normal adult rats would alter glucose homeostasis and insulin action. Regular chow-fed and high-fat-fed male Sprage-Dawley rats were treated with an antisense oligonucleotide (ASO) against SRC1 or a control ASO for 4 wk, followed by metabolic assessments. SRC1 ASO did not alter basal EGP or expression of gluconeogenic enzymes. Instead, SRC1 ASO increased insulin-stimulated whole body glucose disposal by ~30%, which was attributable largely to an increase in insulin-stimulated muscle glucose uptake. This was associated with an approximately sevenfold increase in adipose expression of lipocalin-type prostaglandin D2 synthase, a previously reported regulator of insulin sensitivity, and an approximately 70% increase in plasma PGD2 concentration. Muscle insulin signaling, AMPK activation, and tissue perfusion were unchanged. Although GLUT4 content was unchanged, SRC1 ASO increased the cleavage of tether-containing UBX domain for GLUT4, a regulator of GLUT4 translocation. These studies point to a novel role of adipose SRC1 as a regulator of insulin-stimulated muscle glucose uptake.
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Affiliation(s)
- Jennifer L Cantley
- Howard Hughes Medical Institute and Departments of Internal Medicine and
| | | | | | | | | | | | - Naoki Kumashiro
- Howard Hughes Medical Institute and Departments of Internal Medicine and
| | | | - Arijeet K Gattu
- Departments of Internal Medicine and West Haven Veterans Affairs Medical Center, West Haven, Connecticut
| | | | | | | | - Louis Ragolia
- Vascular Biology Institute, Winthrop-University Hospital, Mineola, New York
| | - Christopher E Hall
- Vascular Biology Institute, Winthrop-University Hospital, Mineola, New York
| | | | | | - Jonathan S Bogan
- Departments of Internal Medicine and Cell Biology, Yale School of Medicine, New Haven, Connecticut
| | - Varman T Samuel
- Departments of Internal Medicine and West Haven Veterans Affairs Medical Center, West Haven, Connecticut;
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87
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Abstract
In recent years white adipose tissue inflammation has been recognized to be associated with obesity. Adipocytes and adipose tissue associated macrophages (ATMs) secrete bioactive molecules, including adipokines, chemokines/cytokines and free fatty acids that modulate the development of low-grade inflammation and insulin resistance responsible for obesity-related metabolic and cardiovascular diseases. Nuclear receptors, notably peroxisome-proliferator-activated receptors, are sensors of dietary lipids and control transcriptional programs of key metabolic and inflammatory pathways in adipocytes and macrophages. This review focuses on mechanisms by which nuclear receptors maintain white adipose tissue homeostasis. The identification of ATMs as active players in the initiation of chronic inflammation and the links between inflammatory signaling and metabolic dysfunction will be presented, followed by discussion of recent evidence for nuclear receptors in ATM function, with an emphasis on the paracrine interaction between adipocytes and ATMs.
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88
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Sharma BK, Patil M, Satyanarayana A. Negative regulators of brown adipose tissue (BAT)-mediated thermogenesis. J Cell Physiol 2014; 229:1901-7. [PMID: 24809334 DOI: 10.1002/jcp.24664] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2014] [Accepted: 05/06/2014] [Indexed: 12/12/2022]
Abstract
Brown adipose tissue (BAT) is specialized for energy expenditure, a process called adaptive thermogenesis. PET-CT scans recently demonstrated the existence of metabolically active BAT in adult humans, which revitalized our interest in BAT. Increasing the amount and/or activity of BAT holds tremendous promise for the treatment of obesity and its associated diseases. PGC1α is the master regulator of UCP1-mediated thermogenesis in BAT. A number of proteins have been identified to influence thermogenesis either positively or negatively through regulating the expression or transcriptional activity of PGC1α. Therefore, BAT activation can be achieved by either inducing the expression of positive regulators of PGC1α or by inhibiting the repressors of the PGC1α/UCP1 pathway. Here, we review the most important negative regulators of PGC1α/UCP1 signaling and their mechanism of action in BAT-mediated thermogenesis.
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Affiliation(s)
- Bal Krishan Sharma
- Department of Biochemistry and Molecular Biology, Molecular Oncology and Biomarkers Program, Georgia Regents University Cancer Center, Georgia Regents University, Augusta, Georgia
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89
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Bhat M, Noolu B, Qadri SSYH, Ismail A. Vitamin D deficiency decreases adiposity in rats and causes altered expression of uncoupling proteins and steroid receptor coactivator3. J Steroid Biochem Mol Biol 2014; 144 Pt B:304-12. [PMID: 25132457 DOI: 10.1016/j.jsbmb.2014.08.005] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/19/2014] [Revised: 08/01/2014] [Accepted: 08/08/2014] [Indexed: 12/15/2022]
Abstract
The vitamin D endocrine system is functional in the adipose tissue, as demonstrated in vitro, in cultured adipocytes, and in vivo in mutant mice that developed altered lipid metabolism and fat storage in the absence of either 1,25-dihydroxyvitamin D3 [1,25(OH)2D3] or the vitamin D receptor. The aim of the present study was to examine the role of vitamin D and calcium on body adiposity in a diet-induced vitamin D deficient rat model. Vitamin D-deficient rats gained less weight and had lower amounts of visceral fat. Consistent with reduced adipose tissue mass, the vitamin D-deficient rats had low circulating levels of leptin, which reflects body fat stores. Expression of vitamin D and calcium sensing receptors, and that of genes involved in adipogenesis such as peroxisome proliferator-activated receptor, fatty acid synthase and leptin were significantly reduced in white adipose tissue of deficient rats compared to vitamin D-sufficient rats. Furthermore, the expression of uncoupling proteins (Ucp1 and Ucp2) was elevated in the white adipose tissue of the deficient rat indicative of higher energy expenditure, thereby leading to a lean phenotype. Expression of the p160 steroid receptor coactivator3 (SRC3), a key regulator of adipogenesis in white adipose tissue was decreased in vitamin D-deficient state. Interestingly, most of the changes observed in vitamin D deficient rats were corrected by calcium supplementation alone. Our data demonstrates that dietary vitamin D and calcium regulate adipose tissue function and metabolism.
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Affiliation(s)
| | - Bindu Noolu
- Department of Endocrinology and Metabolism, Hyderabad, India
| | - Syed S Y H Qadri
- Department of Pathology, National Institute of Nutrition, Hyderabad, India
| | - Ayesha Ismail
- Department of Endocrinology and Metabolism, Hyderabad, India.
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90
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Dasgupta S, O'Malley BW. Transcriptional coregulators: emerging roles of SRC family of coactivators in disease pathology. J Mol Endocrinol 2014; 53:R47-59. [PMID: 25024406 PMCID: PMC4152414 DOI: 10.1530/jme-14-0080] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Transcriptional coactivators have evolved as an important new class of functional proteins that participate with virtually all transcription factors and nuclear receptors (NRs) to intricately regulate gene expression in response to a wide variety of environmental cues. Recent findings have highlighted that coactivators are important for almost all biological functions, and consequently, genetic defects can lead to severe pathologies. Drug discovery efforts targeting coactivators may prove valuable for treatment of a variety of diseases.
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Affiliation(s)
- Subhamoy Dasgupta
- Department of Molecular and Cellular BiologyBaylor College of Medicine, One Baylor Plaza, Houston, Texas 77030, USA
| | - Bert W O'Malley
- Department of Molecular and Cellular BiologyBaylor College of Medicine, One Baylor Plaza, Houston, Texas 77030, USA
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91
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Abstract
Obesity and related diseases are a major cause of human morbidity and mortality and constitute a substantial economic burden for society. Effective treatment regimens are scarce, and new therapeutic targets are needed. Brown adipose tissue, an energy-expending tissue that produces heat, represents a potential therapeutic target. Its presence is associated with low body mass index, low total adipose tissue content and a lower risk of type 2 diabetes mellitus. Knowledge about the development and function of thermogenic adipocytes in brown adipose tissue has increased substantially in the last decade. Important transcriptional regulators have been identified, and hormones able to modulate the thermogenic capacity of the tissue have been recognized. Intriguingly, it is now clear that humans, like rodents, possess two types of thermogenic adipocytes: the classical brown adipocytes found in the interscapular brown adipose organ and the so-called beige adipocytes primarily found in subcutaneous white adipose tissue after adrenergic stimulation. The presence of two distinct types of energy-expending adipocytes in humans is conceptually important because these cells might be stimulated and recruited by different signals, raising the possibility that they might be separate potential targets for therapeutic intervention. In this review, we will discuss important features of the energy-expending brown adipose tissue and highlight those that may serve as potential targets for pharmacological intervention aimed at expanding the tissue and/or enhancing its function to counteract obesity.
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Affiliation(s)
- M E Lidell
- Department of Medical and Clinical Genetics, Institute of Biomedicine, The Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
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92
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Yoshino S, Satoh T, Yamada M, Hashimoto K, Tomaru T, Katano-Toki A, Kakizaki S, Okada S, Shimizu H, Ozawa A, Tuchiya T, Ikota H, Nakazato Y, Mori M, Matozaki T, Sasaki T, Kitamura T, Mori M. Protection against high-fat diet-induced obesity in Helz2-deficient male mice due to enhanced expression of hepatic leptin receptor. Endocrinology 2014; 155:3459-72. [PMID: 25004093 DOI: 10.1210/en.2013-2160] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Obesity arises from impaired energy balance, which is centrally coordinated by leptin through activation of the long form of leptin receptor (Leprb). Obesity causes central leptin resistance. However, whether enhanced peripheral leptin sensitivity could overcome central leptin resistance remains obscure. A peripheral metabolic organ targeted by leptin is the liver, with low Leprb expression. We here show that mice fed a high-fat diet (HFD) and obese patients with hepatosteatosis exhibit increased expression of hepatic helicase with zinc finger 2, a transcriptional coactivator (Helz2), which functions as a transcriptional coregulator of several nuclear receptors, including peroxisome proliferator-activated receptor γ in vitro. To explore the physiological importance of Helz2, we generated Helz2-deficient mice and analyzed their metabolic phenotypes. Helz2-deficient mice showing hyperleptinemia associated with central leptin resistance were protected against HFD-induced obesity and had significantly up-regulated hepatic Leprb expression. Helz2 deficiency and adenovirus-mediated liver-specific exogenous Leprb overexpression in wild-type mice significantly stimulated hepatic AMP-activated protein kinase on HFD, whereas Helz2-deficient db/db mice lacking functional Leprb did not. Fatty acid-β oxidation was increased in Helz2-deficeint hepatocytes, and Helz2-deficient mice revealed increased oxygen consumption and decreased respiratory quotient in calorimetry analyses. The enhanced hepatic AMP-activated protein kinase energy-sensing pathway in Helz2-deficient mice ameliorated hyperlipidemia, hepatosteatosis, and insulin resistance by reducing lipogenic gene expression and stimulating lipid-burning gene expression in the liver. These findings together demonstrate that Helz2 deficiency ameliorates HFD-induced metabolic abnormalities by stimulating endogenous hepatic Leprb expression, despite central leptin resistance. Hepatic HELZ2 might be a novel target molecule for the treatment of obesity with hepatosteatosis.
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Affiliation(s)
- Satoshi Yoshino
- Departments of Medicine and Molecular Science (S.Y., T.Sat., M.Y., K.H., T.To., A.K.-T., S.K., S.O., H.S., A.O., T.Tu., Ma.Mori) and Human Pathology (H.I., Y.N.), Gunma University Graduate School of Medicine, Maebashi, 371-8511 Japan; Laboratory of Biosignal Sciences (Mu.Mori, T.Ma.) and Metabolic Signal Research Center, Institute for Molecular and Cellular Regulation (T.Sas., T.K.), Gunma University, Maebashi, 371-8512 Japan; and Kitakanto Molecular Novel Research Institute for Obesity and Metabolism (Ma.Mori), Midori, 379-2311 Japan
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93
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Chou CF, Lin YY, Wang HK, Zhu X, Giovarelli M, Briata P, Gherzi R, Garvey WT, Chen CY. KSRP ablation enhances brown fat gene program in white adipose tissue through reduced miR-150 expression. Diabetes 2014; 63:2949-61. [PMID: 24722250 PMCID: PMC4141372 DOI: 10.2337/db13-1901] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Brown adipose tissue oxidizes chemical energy for heat generation and energy expenditure. Promoting brown-like transformation in white adipose tissue (WAT) is a promising strategy for combating obesity. Here, we find that targeted deletion of KH-type splicing regulatory protein (KSRP), an RNA-binding protein that regulates gene expression at multiple levels, causes a reduction in body adiposity. The expression of brown fat-selective genes is increased in subcutaneous/inguinal WAT (iWAT) of Ksrp(-/-) mice because of the elevated expression of PR domain containing 16 and peroxisome proliferator-activated receptor gamma coactivator 1α, which are key regulators promoting the brown fat gene program. The expression of microRNA (miR)-150 in iWAT is decreased due to impaired primary miR-150 processing in the absence of KSRP. We show that miR-150 directly targets and represses Prdm16 and Ppargc1a, and that forced expression of miR-150 attenuates the elevated expression of brown fat genes caused by KSRP deletion. This study reveals the in vivo function of KSRP in controlling brown-like transformation of iWAT through post-transcriptional regulation of miR-150 expression.
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Affiliation(s)
- Chu-Fang Chou
- Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham, AL
| | - Yi-Yu Lin
- Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham, AL
| | - Hsu-Kun Wang
- Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham, AL
| | - Xiaolin Zhu
- Department of Nutrition Sciences, University of Alabama at Birmingham, Birmingham, AL
| | - Matteo Giovarelli
- Gene Expression Regulation Laboratory, Istituto Nazionale per la Ricerca sul Cancro, Genova, Italy
| | - Paola Briata
- Gene Expression Regulation Laboratory, Istituto Nazionale per la Ricerca sul Cancro, Genova, Italy
| | - Roberto Gherzi
- Gene Expression Regulation Laboratory, Istituto Nazionale per la Ricerca sul Cancro, Genova, Italy
| | - W Timothy Garvey
- Department of Nutrition Sciences, University of Alabama at Birmingham, Birmingham, AL
| | - Ching-Yi Chen
- Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham, AL
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94
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Tannour-Louet M, York B, Tang K, Stashi E, Bouguerra H, Zhou S, Yu H, Wong LJC, Stevens RD, Xu J, Newgard CB, O'Malley BW, Louet JF. Hepatic SRC-1 activity orchestrates transcriptional circuitries of amino acid pathways with potential relevance for human metabolic pathogenesis. Mol Endocrinol 2014; 28:1707-18. [PMID: 25148457 DOI: 10.1210/me.2014-1083] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Disturbances in amino acid metabolism are increasingly recognized as being associated with, and serving as prognostic markers for chronic human diseases, such as cancer or type 2 diabetes. In the current study, a quantitative metabolomics profiling strategy revealed global impairment in amino acid metabolism in mice deleted for the transcriptional coactivator steroid receptor coactivator (SRC)-1. Aberrations were hepatic in origin, because selective reexpression of SRC-1 in the liver of SRC-1 null mice largely restored amino acids concentrations to normal levels. Cistromic analysis of SRC-1 binding sites in hepatic tissues confirmed a prominent influence of this coregulator on transcriptional programs regulating amino acid metabolism. More specifically, SRC-1 markedly impacted tyrosine levels and was found to regulate the transcriptional activity of the tyrosine aminotransferase (TAT) gene, which encodes the rate-limiting enzyme of tyrosine catabolism. Consequently, SRC-1 null mice displayed low TAT expression and presented with hypertyrosinemia and corneal alterations, 2 clinical features observed in the human syndrome of TAT deficiency. A heterozygous missense variant of SRC-1 (p.P1272S) that is known to alter its coactivation potential, was found in patients harboring idiopathic tyrosinemia-like disorders and may therefore represent one risk factor for their clinical symptoms. Hence, we reinforce the concept that SRC-1 is a central factor in the fine orchestration of multiple pathways of intermediary metabolism, suggesting it as a potential therapeutic target that may be exploitable in human metabolic diseases and cancer.
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Affiliation(s)
- Mounia Tannour-Louet
- Departments of Molecular and Cellular Biology (M.T.-L., B.Y., K.T., E.S., S.Z., J.X., B.W.O., J.-F.L.), Urology (M.T.-L.), and Molecular and Human Genetics (H.Y., L.-J.C.W.), Baylor College of Medicine, Houston, Texas 77030; Sarah W. Stedman Nutrition and Metabolism Center and Department of Pharmacology and Cancer Biology (R.D.S., C.B.N.), Duke University Medical Center, Durham, North Carolina 27704; Laboratory of Genetics, Immunology and Human Pathologies (H.B.), Faculty of Mathematical, Physical, and Natural Sciences of Tunis, Tunis EL Manar University, Tunis 2092, Tunisia; and Centre Méditerranéen de Médecine Moléculaire (H.B., J.-F.L.), Inserm 1065, Nice 06204, France
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95
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Rajan S, Gupta A, Beg M, Shankar K, Srivastava A, Varshney S, Kumar D, Gaikwad AN. Adipocyte transdifferentiation and its molecular targets. Differentiation 2014; 87:183-92. [PMID: 25130315 DOI: 10.1016/j.diff.2014.07.002] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2014] [Revised: 07/02/2014] [Accepted: 07/24/2014] [Indexed: 01/19/2023]
Abstract
According to the World Health Organization obesity is defined as the excessive accumulation of fat, which increases risk of other metabolic disorders such as insulin resistance, dyslipidemia, hypertension, cardiovascular diseases, etc. There are two types of adipose tissue, white and brown adipose tissue (BAT) and the latter has recently gathered interest of the scientific community. Discovery of BAT has opened avenues for a new therapeutic strategy for the treatment of obesity and related metabolic syndrome. BAT utilizes accumulated fatty acids for energy expenditure; hence it is seen as one of the possible alternates to the current treatment. Moreover, browning of white adipocyte on exposure to cold, as well as with some of the pharmacological agents presents exciting outcomes and indicates the feasibility of transdifferentiation. A better understanding of molecular pathways and differentiation factors, those that play a key role in transdifferentiation are of extreme importance in designing novel strategies for the treatment of obesity and associated metabolic disorders.
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Affiliation(s)
- Sujith Rajan
- Division of Pharmacology, CSIR-Central Drug Research Institute, Lucknow, 226031 UP, India; Academy of Scientific and Innovative Research, CSIR-CDRI, India
| | - Abhishek Gupta
- Division of Pharmacology, CSIR-Central Drug Research Institute, Lucknow, 226031 UP, India
| | - Muheeb Beg
- Division of Pharmacology, CSIR-Central Drug Research Institute, Lucknow, 226031 UP, India
| | - Kripa Shankar
- Division of Pharmacology, CSIR-Central Drug Research Institute, Lucknow, 226031 UP, India
| | - Ankita Srivastava
- Division of Pharmacology, CSIR-Central Drug Research Institute, Lucknow, 226031 UP, India; Academy of Scientific and Innovative Research, CSIR-CDRI, India
| | - Salil Varshney
- Division of Pharmacology, CSIR-Central Drug Research Institute, Lucknow, 226031 UP, India
| | - Durgesh Kumar
- Division of Pharmacology, CSIR-Central Drug Research Institute, Lucknow, 226031 UP, India; Academy of Scientific and Innovative Research, CSIR-CDRI, India
| | - Anil Nilkanth Gaikwad
- Division of Pharmacology, CSIR-Central Drug Research Institute, Lucknow, 226031 UP, India; Academy of Scientific and Innovative Research, CSIR-CDRI, India.
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96
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Voisin S, Almén MS, Moschonis G, Chrousos GP, Manios Y, Schiöth HB. Dietary fat quality impacts genome-wide DNA methylation patterns in a cross-sectional study of Greek preadolescents. Eur J Hum Genet 2014; 23:654-62. [PMID: 25074463 PMCID: PMC4402618 DOI: 10.1038/ejhg.2014.139] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2014] [Revised: 06/16/2014] [Accepted: 06/20/2014] [Indexed: 12/04/2022] Open
Abstract
The type and the amount of dietary fat have a significant influence on the metabolic pathways involved in the development of obesity, metabolic syndrome, diabetes type 2 and cardiovascular diseases. However, it is unknown to what extent this modulation is achieved through DNA methylation. We assessed the effects of cholesterol intake, the proportion of energy intake derived from fat, the ratio of polyunsaturated fatty acids (PUFA) to saturated fatty acids (SFA), the ratio of monounsaturated fatty acids (MUFA) to SFA, and the ratio of MUFA+PUFA to SFA on genome-wide DNA methylation patterns in normal-weight and obese children. We determined the genome-wide methylation profile in the blood of 69 Greek preadolescents (∼10 years old) as well as their dietary intake for two consecutive weekdays and one weekend day. The methylation levels of one CpG island shore and four sites were significantly correlated with total fat intake. The methylation levels of 2 islands, 11 island shores and 16 sites were significantly correlated with PUFA/SFA; of 9 islands, 26 island shores and 158 sites with MUFA/SFA; and of 10 islands, 40 island shores and 130 sites with (MUFA+PUFA)/SFA. We found significant gene enrichment in 34 pathways for PUFA/SFA, including the leptin pathway, and a significant enrichment in 5 pathways for (MUFA+PUFA)/SFA. Our results suggest that specific changes in DNA methylation may have an important role in the mechanisms involved in the physiological responses to different types of dietary fat.
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Affiliation(s)
- Sarah Voisin
- Department of Neuroscience, Functional Pharmacology, Uppsala University, Uppsala, Sweden
| | - Markus S Almén
- Department of Neuroscience, Functional Pharmacology, Uppsala University, Uppsala, Sweden
| | - George Moschonis
- Department of Nutrition and Dietetics, Harokopio University, Athens, Greece
| | - George P Chrousos
- First Department of Pediatrics, Athens University Medical School, Aghia Sophia Children's Hospital, Athens, Greece
| | - Yannis Manios
- Department of Nutrition and Dietetics, Harokopio University, Athens, Greece
| | - Helgi B Schiöth
- Department of Neuroscience, Functional Pharmacology, Uppsala University, Uppsala, Sweden
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97
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Stashi E, York B, O'Malley BW. Steroid receptor coactivators: servants and masters for control of systems metabolism. Trends Endocrinol Metab 2014; 25:337-47. [PMID: 24953190 PMCID: PMC4108168 DOI: 10.1016/j.tem.2014.05.004] [Citation(s) in RCA: 73] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/10/2014] [Revised: 05/12/2014] [Accepted: 05/13/2014] [Indexed: 11/30/2022]
Abstract
Coregulator recruitment to nuclear receptors (NRs) and other transcription factors is essential for proper metabolic gene regulation, with coactivators enhancing and corepressors attenuating gene transcription. The steroid receptor coactivator (SRC) family is composed of three homologous members (SRC-1, SRC-2, and SRC-3), which are uniquely important for mediating steroid hormone and mitogenic actions. An accumulating body of work highlights the diverse array of metabolic functions regulated by the SRCs, including systemic metabolite homeostasis, inflammation, and energy regulation. We discuss here the cooperative and unique functions among the SRCs to provide a comprehensive atlas of systemic SRC metabolic regulation. Deciphering the fractional and synergistic contributions of the SRCs to metabolic homeostasis is crucial to understanding fully the networks underlying metabolic transcriptional regulation.
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Affiliation(s)
- Erin Stashi
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX, USA
| | - Brian York
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX, USA
| | - Bert W O'Malley
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX, USA.
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98
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Transcriptional coregulators: fine-tuning metabolism. Cell Metab 2014; 20:26-40. [PMID: 24794975 PMCID: PMC4079747 DOI: 10.1016/j.cmet.2014.03.027] [Citation(s) in RCA: 73] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/14/2013] [Revised: 02/28/2014] [Accepted: 03/18/2014] [Indexed: 12/21/2022]
Abstract
Metabolic homeostasis requires that cellular energy levels are adapted to environmental cues. This adaptation is largely regulated at the transcriptional level, through the interaction between transcription factors, coregulators, and the basal transcriptional machinery. Coregulators, which function as both metabolic sensors and transcriptional effectors, are ideally positioned to synchronize metabolic pathways to environmental stimuli. The balance between inhibitory actions of corepressors and stimulatory effects of coactivators enables the fine-tuning of metabolic processes. This tight regulation opens therapeutic opportunities to manage metabolic dysfunction by directing the activity of cofactors toward specific transcription factors, pathways, or cells/tissues, thereby restoring whole-body metabolic homeostasis.
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99
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Sim WC, Park S, Lee KY, Je YT, Yin HQ, Choi YJ, Sung SH, Park SJ, Park HJ, Shin KJ, Lee BH. LXR-α antagonist meso-dihydroguaiaretic acid attenuates high-fat diet-induced nonalcoholic fatty liver. Biochem Pharmacol 2014; 90:414-24. [PMID: 24955981 DOI: 10.1016/j.bcp.2014.06.013] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2014] [Revised: 06/14/2014] [Accepted: 06/16/2014] [Indexed: 01/17/2023]
Abstract
Collaborative regulation of liver X receptor (LXR) and sterol regulatory element binding protein (SREBP)-1 are main determinants in hepatic steatosis, as shown in both animal models and human patients. Recent studies indicate that selective intervention of overly functional LXRα in the liver shows promise in treatment of fatty liver disease. In the present study, we evaluated the effects of meso-dihydroguaiaretic acid (MDGA) on LXRα activation and its ability to attenuate fatty liver in mice. MDGA inhibited activation of the LXRα ligand-binding domain by competitively binding to the pocket for agonist T0901317 and decreased the luciferase activity in LXRE-tk-Luc-transfected cells. MDGA significantly attenuated hepatic neutral lipid accumulation in T0901317- and high fat diet (HFD)-induced fatty liver. The effect of MDGA was so potent that treatment with 1mg/kg for 2 weeks completely reversed the lipid accumulation induced by HFD feeding. MDGA reduced the expression of LXRα co-activator protein RIP140 and LXRα target gene products associated with lipogenesis in HFD-fed mice. These results demonstrate that MDGA has the potential to attenuate nonalcoholic steatosis mediated by selective inhibition of LXRα in the liver in mice.
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Affiliation(s)
- Woo-Cheol Sim
- College of Pharmacy and Research Institute of Pharmaceutical Sciences, Seoul National University, Gwanak-ro 1, Gwanak-gu, Seoul 151-742, Republic of Korea
| | - Sora Park
- College of Pharmacy and Research Institute of Pharmaceutical Sciences, Seoul National University, Gwanak-ro 1, Gwanak-gu, Seoul 151-742, Republic of Korea
| | - Kang-Yo Lee
- College of Pharmacy and Research Institute of Pharmaceutical Sciences, Seoul National University, Gwanak-ro 1, Gwanak-gu, Seoul 151-742, Republic of Korea
| | - Young-Tae Je
- College of Pharmacy and Research Institute of Pharmaceutical Sciences, Seoul National University, Gwanak-ro 1, Gwanak-gu, Seoul 151-742, Republic of Korea
| | - Hu-Quan Yin
- College of Pharmacy and Research Institute of Pharmaceutical Sciences, Seoul National University, Gwanak-ro 1, Gwanak-gu, Seoul 151-742, Republic of Korea
| | - You-Jin Choi
- College of Pharmacy and Research Institute of Pharmaceutical Sciences, Seoul National University, Gwanak-ro 1, Gwanak-gu, Seoul 151-742, Republic of Korea
| | - Sang Hyun Sung
- College of Pharmacy and Research Institute of Pharmaceutical Sciences, Seoul National University, Gwanak-ro 1, Gwanak-gu, Seoul 151-742, Republic of Korea
| | - So-Jung Park
- School of Pharmacy, Sungkyunkwan University, Seobu-ro 2066, Jangan-gu, Suwon 440-746, Republic of Korea
| | - Hyun-Ju Park
- School of Pharmacy, Sungkyunkwan University, Seobu-ro 2066, Jangan-gu, Suwon 440-746, Republic of Korea
| | - Kye Jung Shin
- College of Pharmacy, The Catholic University, Bucheon 420-743, Republic of Korea
| | - Byung-Hoon Lee
- College of Pharmacy and Research Institute of Pharmaceutical Sciences, Seoul National University, Gwanak-ro 1, Gwanak-gu, Seoul 151-742, Republic of Korea.
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LSD1 promotes oxidative metabolism of white adipose tissue. Nat Commun 2014; 5:4093. [PMID: 24912735 PMCID: PMC4112219 DOI: 10.1038/ncomms5093] [Citation(s) in RCA: 86] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2013] [Accepted: 05/12/2014] [Indexed: 01/25/2023] Open
Abstract
Exposure to environmental cues such as cold or nutritional imbalance requires white adipose tissue (WAT) to adapt its metabolism to ensure survival. Metabolic plasticity is prominently exemplified by the enhancement of mitochondrial biogenesis in WAT in response to cold exposure or β3-adrenergic stimulation. Here we show that these stimuli increase the levels of lysine-specific demethylase 1 (LSD1) in WAT of mice and that elevated LSD1 levels induce mitochondrial activity. Genome-wide binding and transcriptome analyses demonstrate that LSD1 directly stimulates the expression of genes involved in oxidative phosphorylation (OXPHOS) in cooperation with nuclear respiratory factor 1 (Nrf1). In transgenic (Tg) mice, increased levels of LSD1 promote in a cell-autonomous manner the formation of islets of metabolically active brown-like adipocytes in WAT. Notably, Tg mice show limited weight gain when fed a high-fat diet. Taken together, our data establish LSD1 as a key regulator of OXPHOS and metabolic adaptation in WAT.
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