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Abbasi K, Zarezadeh R, Valizadeh A, Mehdizadeh A, Hamishehkar H, Nouri M, Darabi M. White-brown adipose tissue interplay in polycystic ovary syndrome: Therapeutic avenues. Biochem Pharmacol 2024; 220:116012. [PMID: 38159686 DOI: 10.1016/j.bcp.2023.116012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2023] [Accepted: 12/22/2023] [Indexed: 01/03/2024]
Abstract
This study highlights the therapeutic potential of activating brown adipose tissue (BAT) for managing polycystic ovary syndrome (PCOS), a prevalent endocrine disorder associated with metabolic and reproductive abnormalities. BAT plays a crucial role in regulating energy expenditure and systemic insulin sensitivity, making it an attractive target for the treatment of obesity and metabolic diseases. Recent research suggests that impaired BAT function and mass may contribute to the link between metabolic disturbances and reproductive issues in PCOS. Additionally, abnormal white adipose tissue (WAT) can exacerbate these conditions by releasing adipokines and nonesterified fatty acids. In this review, we explored the impact of WAT changes on BAT function in PCOS and discussed the potential of BAT activation as a therapeutic strategy to improve PCOS symptoms. We propose that BAT activation holds promise for managing PCOS; however, further research is needed to confirm its efficacy and to develop clinically feasible methods for BAT activation.
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Affiliation(s)
- Khadijeh Abbasi
- Drug Applied Research Center, Tabriz University of Medical Sciences, Tabriz, Iran; Department of Biochemistry and Clinical Laboratories, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Reza Zarezadeh
- Women's Reproductive Health Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Amir Valizadeh
- Student Research Committee, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Amir Mehdizadeh
- Hematology and Oncology Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Hamed Hamishehkar
- Drug Applied Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Mohammad Nouri
- Drug Applied Research Center, Tabriz University of Medical Sciences, Tabriz, Iran.
| | - Masoud Darabi
- Department of Biochemistry and Clinical Laboratories, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran; Division of Experimental Oncology, Department of Hematology and Oncology, University Medical Center Schleswig-Holstein, Campus Lübeck, Germany.
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2
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Li J, Li J, Zhao WG, Sun HD, Guo ZG, Liu XY, Tang XY, She ZF, Yuan T, Liu SN, Liu Q, Fu Y, Sun W. Comprehensive proteomics and functional annotation of mouse brown adipose tissue. PLoS One 2020; 15:e0232084. [PMID: 32374735 PMCID: PMC7202602 DOI: 10.1371/journal.pone.0232084] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Accepted: 04/07/2020] [Indexed: 12/13/2022] Open
Abstract
Knowledge about the mouse brown adipose tissue (BAT) proteome can provide a deeper understanding of the function of mammalian BAT. Herein, a comprehensive analysis of interscapular BAT from C57BL/6J female mice was conducted by 2DLC and high-resolution mass spectrometry to construct a comprehensive proteome dataset of mouse BAT proteins. A total of 4949 nonredundant proteins were identified, and 4495 were quantified using the iBAQ method. According to the iBAQ values, the BAT proteome was divided into high-, middle- and low-abundance proteins. The functions of the high-abundance proteins were mainly related to glucose and fatty acid oxidation to produce heat for thermoregulation, while the functions of the middle- and low-abundance proteins were mainly related to protein synthesis and apoptosis, respectively. Additionally, 497 proteins were predicted to have signal peptides using SignalP4 software, and 75 were confirmed in previous studies. This study, for the first time, comprehensively profiled and functionally annotated the BAT proteome. This study will be helpful for future studies focused on biomarker identification and BAT molecular mechanisms.
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Affiliation(s)
- Jing Li
- Core Facility of Instrument, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences/School of Basic Medicine, Peking Union Medical College, Beijing, China
| | - Juan Li
- Key Laboratory of Endocrinology of Ministry of Health, Department of Endocrinology, Peking Union Medical College Hospital, Chinese Academy of Medical Science and Peking Union Medical College, Beijing, China
| | - Wei-Gang Zhao
- Key Laboratory of Endocrinology of Ministry of Health, Department of Endocrinology, Peking Union Medical College Hospital, Chinese Academy of Medical Science and Peking Union Medical College, Beijing, China
- * E-mail: (WS); (W-GZ)
| | - Hai-Dan Sun
- Core Facility of Instrument, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences/School of Basic Medicine, Peking Union Medical College, Beijing, China
| | - Zheng-Guang Guo
- Core Facility of Instrument, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences/School of Basic Medicine, Peking Union Medical College, Beijing, China
| | - Xiao-Yan Liu
- Core Facility of Instrument, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences/School of Basic Medicine, Peking Union Medical College, Beijing, China
| | - Xiao-Yue Tang
- Core Facility of Instrument, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences/School of Basic Medicine, Peking Union Medical College, Beijing, China
| | - Zhu-Fang She
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Diabetes Research Center of Chinese Academy of Medical Sciences, Beijing, China
| | - Tao Yuan
- Key Laboratory of Endocrinology of Ministry of Health, Department of Endocrinology, Peking Union Medical College Hospital, Chinese Academy of Medical Science and Peking Union Medical College, Beijing, China
| | - Shuai-Nan Liu
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Diabetes Research Center of Chinese Academy of Medical Sciences, Beijing, China
| | - Quan Liu
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Diabetes Research Center of Chinese Academy of Medical Sciences, Beijing, China
| | - Yong Fu
- Key Laboratory of Endocrinology of Ministry of Health, Department of Endocrinology, Peking Union Medical College Hospital, Chinese Academy of Medical Science and Peking Union Medical College, Beijing, China
| | - Wei Sun
- Core Facility of Instrument, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences/School of Basic Medicine, Peking Union Medical College, Beijing, China
- * E-mail: (WS); (W-GZ)
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de Sousa GC, Cruz FF, Heil LB, Sobrinho CJS, Saddy F, Knibel FP, Pereira JB, Schultz MJ, Pelosi P, Gama de Abreu M, Silva PL, Rocco PRM. Intraoperative immunomodulatory effects of sevoflurane versus total intravenous anesthesia with propofol in bariatric surgery (the OBESITA trial): study protocol for a randomized controlled pilot trial. Trials 2019; 20:300. [PMID: 31138279 PMCID: PMC6540380 DOI: 10.1186/s13063-019-3399-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2018] [Accepted: 05/06/2019] [Indexed: 02/06/2023] Open
Abstract
Background Obesity is associated with a chronic systemic inflammatory process. Volatile or intravenous anesthetic agents may modulate immune function, and may do so differentially in obesity. However, no study has evaluated whether these potential immunomodulatory effects differ according to type of anesthesia in obese patients undergoing laparoscopic bariatric surgery. Methods/design The OBESITA trial is a prospective, nonblinded, single-center, randomized, controlled clinical pilot trial. The trial will include 48 patients with a body mass index ≥ 35 kg/m2, scheduled for laparoscopic bariatric surgery using sleeve or a Roux-en-Y gastric bypass technique, who will be allocated 1:1 to undergo general inhalational anesthesia with sevoflurane or total intravenous anesthesia (TIVA) with propofol. The primary endpoint is the difference in plasma interleukin (IL)-6 levels when comparing the two anesthetic agents. Blood samples will be collected prior to anesthesia induction (baseline), immediately after anesthetic induction, and before endotracheal extubation. Levels of other proinflammatory and anti-inflammatory cytokines, neutrophil chemotaxis, macrophage differentiation, phagocytosis, and occurrence of intraoperative and postoperative complications will also be evaluated. Discussion To our knowledge, this is the first randomized clinical trial designed to compare the effects of two different anesthetics on immunomodulation in obese patients undergoing laparoscopic bariatric surgery. Our hypothesis is that anesthesia with sevoflurane will result in a weaker proinflammatory response compared to anesthesia with propofol, with lower circulating levels of IL-6 and other proinflammatory mediators, and increased macrophage differentiation into the M2 phenotype in adipose tissue. Trial registration Registro Brasileiro de Ensaios Clínicos, RBR-77kfj5. Registered on 25 July 2018. Electronic supplementary material The online version of this article (10.1186/s13063-019-3399-z) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Giselle Carvalho de Sousa
- Laboratory of Pulmonary Investigation, Carlos Chagas Filho Institute of Biophysics, Federal University of Rio de Janeiro, Centro de Ciências da Saúde, Avenida Carlos Chagas Filho, 373, Bloco G1-014, Ilha do Fundão, Rio de Janeiro, 21941-902, Brazil.,Department of Anesthesiology, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Fernanda Ferreira Cruz
- Laboratory of Pulmonary Investigation, Carlos Chagas Filho Institute of Biophysics, Federal University of Rio de Janeiro, Centro de Ciências da Saúde, Avenida Carlos Chagas Filho, 373, Bloco G1-014, Ilha do Fundão, Rio de Janeiro, 21941-902, Brazil
| | - Luciana Boavista Heil
- Laboratory of Pulmonary Investigation, Carlos Chagas Filho Institute of Biophysics, Federal University of Rio de Janeiro, Centro de Ciências da Saúde, Avenida Carlos Chagas Filho, 373, Bloco G1-014, Ilha do Fundão, Rio de Janeiro, 21941-902, Brazil
| | | | - Felipe Saddy
- Laboratory of Pulmonary Investigation, Carlos Chagas Filho Institute of Biophysics, Federal University of Rio de Janeiro, Centro de Ciências da Saúde, Avenida Carlos Chagas Filho, 373, Bloco G1-014, Ilha do Fundão, Rio de Janeiro, 21941-902, Brazil.,Institute D'Or of Research and Teaching, Rio de Janeiro, Brazil
| | | | | | - Marcus J Schultz
- Department of Intensive Care and Laboratory of Experimental Intensive Care and Anesthesiology (L·E·I·C·A), Amsterdam University Medical Centers, University of Amsterdam, Amsterdam, The Netherlands.,Mahidol Oxford Tropical Medicine Research Unit (MORU), Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Paolo Pelosi
- Department of Surgical Sciences and Integrated Diagnostics, University of Genoa, Genoa, Italy.,Ospedale Policlinico San Martino, IRCCS for Oncology and Neurosciences, Genoa, Italy
| | - Marcelo Gama de Abreu
- Pulmonary Engineering Group, Department of Anesthesiology and Intensive Care Medicine, University Hospital Carl Gustav Carus, Dresden, Germany
| | - Pedro Leme Silva
- Laboratory of Pulmonary Investigation, Carlos Chagas Filho Institute of Biophysics, Federal University of Rio de Janeiro, Centro de Ciências da Saúde, Avenida Carlos Chagas Filho, 373, Bloco G1-014, Ilha do Fundão, Rio de Janeiro, 21941-902, Brazil
| | - Patricia Rieken Macedo Rocco
- Laboratory of Pulmonary Investigation, Carlos Chagas Filho Institute of Biophysics, Federal University of Rio de Janeiro, Centro de Ciências da Saúde, Avenida Carlos Chagas Filho, 373, Bloco G1-014, Ilha do Fundão, Rio de Janeiro, 21941-902, Brazil.
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4
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Su M, Xiao Y, Ma J, Tang Y, Tian B, Zhang Y, Li X, Wu Z, Yang D, Zhou Y, Wang H, Liao Q, Wang W. Circular RNAs in Cancer: emerging functions in hallmarks, stemness, resistance and roles as potential biomarkers. Mol Cancer 2019; 18:90. [PMID: 30999909 PMCID: PMC6471953 DOI: 10.1186/s12943-019-1002-6] [Citation(s) in RCA: 266] [Impact Index Per Article: 53.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2018] [Accepted: 03/13/2019] [Indexed: 02/06/2023] Open
Abstract
Circular RNAs (circRNAs) are a class of RNA molecules with closed loops and high stability. CircRNAs are abundantly expressed in eukaryotic organisms and exhibit both location- and step-specificity. In recent years, circRNAs are attracting considerable research attention attributed to their possible contributions to gene regulation through a variety of actions, including sponging microRNAs, interacting with RNA-binding proteins, regulating transcription and splicing, and protein translation. Growing evidence has revealed that circRNAs play critical roles in the development and progression of diseases, especially in cancers. Without doubt, expanding our understanding of circRNAs will enrich knowledge of cancer and provide new opportunities for cancer therapy. In this review, we provide an overview of the characteristics, functions and functional mechanisms of circRNAs. In particular, we summarize current knowledge regarding the functions of circRNAs in the hallmarks, stemness, resistance of cancer, as well as the possibility of circRNAs as biomarkers in cancer.
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Affiliation(s)
- Min Su
- Department of the 2nd Department of Thoracic Surgery, Hunan Cancer Hospital and The Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, Hunan, 410013, People's Republic of China.,Hunan Key Laboratory of Translational Radiation Oncology, Hunan Cancer Hospital and The Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, China.,Department of the Central Laboratory, Hunan Cancer Hospital and The Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, Hunan, 410013, People's Republic of China
| | - Yuhang Xiao
- Hunan Key Laboratory of Translational Radiation Oncology, Hunan Cancer Hospital and The Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, China.,Department of Pharmacy, Xiangya Hospital of Xiangya School of Medicine, Central South University, Changsha, Hunan, 410001, People's Republic of China
| | - Junliang Ma
- Department of the 2nd Department of Thoracic Surgery, Hunan Cancer Hospital and The Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, Hunan, 410013, People's Republic of China
| | - Yanyan Tang
- Hunan Key Laboratory of Translational Radiation Oncology, Hunan Cancer Hospital and The Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, China
| | - Bo Tian
- Department of the 2nd Department of Thoracic Surgery, Hunan Cancer Hospital and The Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, Hunan, 410013, People's Republic of China
| | - Yuqin Zhang
- Department of Pharmacy, Xiangya Hospital of Xiangya School of Medicine, Central South University, Changsha, Hunan, 410001, People's Republic of China
| | - Xu Li
- Department of the 2nd Department of Thoracic Surgery, Hunan Cancer Hospital and The Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, Hunan, 410013, People's Republic of China
| | - Zhining Wu
- Department of the 2nd Department of Thoracic Surgery, Hunan Cancer Hospital and The Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, Hunan, 410013, People's Republic of China
| | - Desong Yang
- Department of the 2nd Department of Thoracic Surgery, Hunan Cancer Hospital and The Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, Hunan, 410013, People's Republic of China
| | - Yong Zhou
- Department of the 2nd Department of Thoracic Surgery, Hunan Cancer Hospital and The Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, Hunan, 410013, People's Republic of China
| | - Hui Wang
- Hunan Key Laboratory of Translational Radiation Oncology, Hunan Cancer Hospital and The Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, China
| | - Qianjin Liao
- Hunan Key Laboratory of Translational Radiation Oncology, Hunan Cancer Hospital and The Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, China. .,Department of the Central Laboratory, Hunan Cancer Hospital and The Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, Hunan, 410013, People's Republic of China.
| | - Wenxiang Wang
- Department of the 2nd Department of Thoracic Surgery, Hunan Cancer Hospital and The Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, Hunan, 410013, People's Republic of China. .,Hunan Key Laboratory of Translational Radiation Oncology, Hunan Cancer Hospital and The Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, China.
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5
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Alcalá M, Calderon-Dominguez M, Serra D, Herrero L, Viana M. Mechanisms of Impaired Brown Adipose Tissue Recruitment in Obesity. Front Physiol 2019; 10:94. [PMID: 30814954 PMCID: PMC6381290 DOI: 10.3389/fphys.2019.00094] [Citation(s) in RCA: 62] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2018] [Accepted: 01/25/2019] [Indexed: 12/18/2022] Open
Abstract
Brown adipose tissue (BAT) dissipates energy to produce heat. Thus, it has the potential to regulate body temperature by thermogenesis. For the last decade, BAT has been in the spotlight due to its rediscovery in adult humans. This is evidenced by over a hundred clinical trials that are currently registered to target BAT as a therapeutic tool in the treatment of metabolic diseases, such as obesity or diabetes. The goal of most of these trials is to activate the BAT thermogenic program via several approaches such as adrenergic stimulation, natriuretic peptides, retinoids, capsinoids, thyroid hormones, or glucocorticoids. However, the impact of BAT activation on total body energy consumption and the potential effect on weight loss is still limited. Other studies have focused on increasing the mass of thermogenic BAT. This can be relevant in obesity, where the activity and abundance of BAT have been shown to be drastically reduced. The aim of this review is to describe pathological processes associated with obesity that may influence the correct differentiation of BAT, such as catecholamine resistance, inflammation, oxidative stress, and endoplasmic reticulum stress. This will shed light on the thermogenic potential of BAT as a therapeutic approach to target obesity-induced metabolic diseases.
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Affiliation(s)
- Martín Alcalá
- Department of Chemistry and Biochemistry, Facultad de Farmacia, Universidad San Pablo-CEU, CEU Universities, Madrid, Spain
| | - María Calderon-Dominguez
- Department of Biochemistry and Physiology, School of Pharmacy, Institut de Biomedicina de la Universitat de Barcelona (IBUB), Universitat de Barcelona, Barcelona, Spain.,Centro de Investigación Biomédica en Red de Fisiopatología de la Obesidad y la Nutrición (CIBEROBN), Instituto de Salud Carlos III, Madrid, Spain
| | - Dolors Serra
- Department of Biochemistry and Physiology, School of Pharmacy, Institut de Biomedicina de la Universitat de Barcelona (IBUB), Universitat de Barcelona, Barcelona, Spain.,Centro de Investigación Biomédica en Red de Fisiopatología de la Obesidad y la Nutrición (CIBEROBN), Instituto de Salud Carlos III, Madrid, Spain
| | - Laura Herrero
- Department of Biochemistry and Physiology, School of Pharmacy, Institut de Biomedicina de la Universitat de Barcelona (IBUB), Universitat de Barcelona, Barcelona, Spain.,Centro de Investigación Biomédica en Red de Fisiopatología de la Obesidad y la Nutrición (CIBEROBN), Instituto de Salud Carlos III, Madrid, Spain
| | - Marta Viana
- Department of Chemistry and Biochemistry, Facultad de Farmacia, Universidad San Pablo-CEU, CEU Universities, Madrid, Spain
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6
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Nedergaard J, Wang Y, Cannon B. Cell proliferation and apoptosis inhibition: essential processes for recruitment of the full thermogenic capacity of brown adipose tissue. Biochim Biophys Acta Mol Cell Biol Lipids 2018; 1864:51-58. [PMID: 29908367 DOI: 10.1016/j.bbalip.2018.06.013] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2018] [Revised: 05/15/2018] [Accepted: 06/11/2018] [Indexed: 12/20/2022]
Abstract
In mice living under normal animal house conditions, the brown adipocytes in classical brown adipose tissue depots are already essentially fully differentiated: UCP1 mRNA and UCP1 protein levels are practically saturated. This means that any further recruitment - in response to cold exposure or any other browning agent - does not result in significant augmentation of these parameters. This may easily be construed to indicate that classical brown adipose tissue cannot be further recruited. However, this is far from the case: the capacity for further recruitment instead lies in the ability of the tissue to increase the number of brown-fat cells, a remarkable and highly controlled physiological recruitment process. We have compiled here the available data concerning the unique ability of norepinephrine to increase cell proliferation and inhibit apoptosis in brown adipocytes. Adrenergically stimulated cell proliferation is fully mediated via β1-adrenoceptors and occurs through activation of stem cells in the tissue; intracellular mediation of the signal involves cAMP and protein kinase A activation, but activation of Erk1/2 is not part of the pathway. Apoptosis inhibition in brown adipocytes is induced by both β- and α1-adrenergic receptors and here the intracellular pathway includes Erk1/2 activation. This unique ability of norepinephrine to increase cell number in an apparently mitogenically dormant tissue provides possibilities to augment the metabolic capacity of brown adipose tissue, also for therapeutic purposes.
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Affiliation(s)
- Jan Nedergaard
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden.
| | - Yanling Wang
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
| | - Barbara Cannon
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
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7
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Lone J, Yun JW. Honokiol exerts dual effects on browning and apoptosis of adipocytes. Pharmacol Rep 2017; 69:1357-1365. [DOI: 10.1016/j.pharep.2017.06.004] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2017] [Revised: 05/06/2017] [Accepted: 06/13/2017] [Indexed: 12/11/2022]
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8
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Hypoxia in Obesity and Diabetes: Potential Therapeutic Effects of Hyperoxia and Nitrate. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2017; 2017:5350267. [PMID: 28607631 PMCID: PMC5457776 DOI: 10.1155/2017/5350267] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/04/2016] [Revised: 04/04/2017] [Accepted: 04/11/2017] [Indexed: 02/06/2023]
Abstract
The prevalence of obesity and diabetes is increasing worldwide. Obesity and diabetes are associated with oxidative stress, inflammation, endothelial dysfunction, insulin resistance, and glucose intolerance. Obesity, a chronic hypoxic state that is associated with decreased nitric oxide (NO) bioavailability, is one of the main causes of type 2 diabetes. The hypoxia-inducible factor-1α (HIF-1α) is involved in the regulation of several genes of the metabolic pathways including proinflammatory adipokines, endothelial NO synthase (eNOS), and insulin signaling components. It seems that adipose tissue hypoxia and NO-dependent vascular and cellular dysfunctions are responsible for other consequences linked to obesity-related disorders. Although hyperoxia could reverse hypoxic-related disorders, it increases the production of reactive oxygen species (ROS) and decreases the production of NO. Nitrate can restore NO depletion and has antioxidant properties, and recent data support the beneficial effects of nitrate therapy in obesity and diabetes. Although it seems reasonable to combine hyperoxia and nitrate treatments for managing obesity/diabetes, the combined effects have not been investigated yet. This review discusses some aspects of tissue oxygenation and the potential effects of hyperoxia and nitrate interventions on obesity/diabetes management. It can be proposed that concomitant use of hyperoxia and nitrate is justified for managing obesity and diabetes.
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Nagel SA, Keuper M, Zagotta I, Enlund E, Ruperez AI, Debatin KM, Wabitsch M, Fischer-Posovszky P. Up-regulation of Bcl-2 during adipogenesis mediates apoptosis resistance in human adipocytes. Mol Cell Endocrinol 2014; 382:368-376. [PMID: 24397922 DOI: 10.1016/j.mce.2013.10.024] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/05/2013] [Revised: 10/16/2013] [Accepted: 10/21/2013] [Indexed: 01/05/2023]
Abstract
Targeting apoptotic pathways in adipocytes has been suggested as a pharmacological approach to treat obesity. However, adipocyte apoptosis was identified as a cause for macrophage infiltration into adipose tissue. Previous studies suggest that mature adipocytes are less sensitive to apoptotic stimuli as compared to preadipocytes. Here, we aimed to identify proteins mediating apoptosis resistance in adipocytes. Our data revealed that the anti-apoptotic protein Bcl-2 (B-cell lymphoma 2) is up-regulated during adipogenic differentiation. Bcl-2 overexpression in preadipocytes lowers their apoptosis sensitivity to the level of mature adipocytes. Vice versa Bcl-2 knockdown in adipocytes sensitizes these cells to CD95-induced apoptosis. Taken together, our findings suggest a shift in the balance of pro-apoptotic and anti-apoptotic molecules during adipogenesis resulting in a higher apoptosis resistance. This study sheds new light on the apoptotic process in human fat cells and may constitute a new possible target for the specific regulation of adipose tissue mass.
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Affiliation(s)
- Stella A Nagel
- Division of Pediatric Endocrinology and Diabetes, Department of Pediatrics and Adolescent Medicine, Ulm University Medical Center, 89075 Ulm, Germany
| | - Michaela Keuper
- Division of Pediatric Endocrinology and Diabetes, Department of Pediatrics and Adolescent Medicine, Ulm University Medical Center, 89075 Ulm, Germany
| | - Ivana Zagotta
- Division of Pediatric Endocrinology and Diabetes, Department of Pediatrics and Adolescent Medicine, Ulm University Medical Center, 89075 Ulm, Germany
| | - Eveliina Enlund
- Division of Pediatric Endocrinology and Diabetes, Department of Pediatrics and Adolescent Medicine, Ulm University Medical Center, 89075 Ulm, Germany
| | - Azahara Iris Ruperez
- Division of Pediatric Endocrinology and Diabetes, Department of Pediatrics and Adolescent Medicine, Ulm University Medical Center, 89075 Ulm, Germany
| | - Klaus-Michael Debatin
- Department of Pediatrics and Adolescent Medicine, Ulm University Medical Center, 89075 Ulm, Germany
| | - Martin Wabitsch
- Division of Pediatric Endocrinology and Diabetes, Department of Pediatrics and Adolescent Medicine, Ulm University Medical Center, 89075 Ulm, Germany.
| | - Pamela Fischer-Posovszky
- Division of Pediatric Endocrinology and Diabetes, Department of Pediatrics and Adolescent Medicine, Ulm University Medical Center, 89075 Ulm, Germany.
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10
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In brown adipocytes, adrenergically induced β1-/β3-(Gs)-, α2-(Gi)- and α1-(Gq)-signalling to Erk1/2 activation is not mediated via EGF receptor transactivation. Exp Cell Res 2013; 319:2718-27. [DOI: 10.1016/j.yexcr.2013.08.007] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2013] [Revised: 08/02/2013] [Accepted: 08/05/2013] [Indexed: 11/15/2022]
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11
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Zhang JF, Yao GY, Wu YH. Expression profiling based on coexpressed modules in obese prepubertal children. GENETICS AND MOLECULAR RESEARCH 2012; 11:3077-85. [PMID: 23007985 DOI: 10.4238/2012.august.31.5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
The aim of this study was to identify related genes and the underlying molecular mechanisms in obese patients who show a series of clinical and metabolic abnormalities known as metabolic syndrome. We identified expression profiles through a coexpression network. In addition, a similarity matrix and expression modules were constructed based on domain and pathway enrichment analysis. The genes in module 1 were mainly involved in the metabolism of xenobiotics by cytochrome P450, aldosterone-regulated sodium reabsorption, and focal adhesion owing to the presence of aldo/ketoreductase, basic helix-loop-helix, von Willebrand factor, Frizzled-related domain, and other domains. The genes in module 3 may be involved in cell cycle (hsa04110) and DNA replication (hsa03030) pathways through mini-chromosome maintenance, serine/threonine protein kinase, the protein kinase domain, and other domains. We analyzed the published molecular mechanisms of obesity and found many genes and pathways that have not been given enough attention and require further confirmation.
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Affiliation(s)
- J F Zhang
- Department of Child Health Care, Shanghai Children's Hospital, Shanghai Jiao Tong University, Shanghai, China
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12
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Elabd C, Chiellini C, Carmona M, Galitzky J, Cochet O, Petersen R, Pénicaud L, Kristiansen K, Bouloumié A, Casteilla L, Dani C, Ailhaud G, Amri EZ. Human multipotent adipose-derived stem cells differentiate into functional brown adipocytes. Stem Cells 2010; 27:2753-60. [PMID: 19697348 DOI: 10.1002/stem.200] [Citation(s) in RCA: 206] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
In contrast to the earlier contention, adult humans have been shown recently to possess active brown adipose tissue with a potential of being of metabolic significance. Up to now, brown fat precursor cells have not been available for human studies. We have shown previously that human multipotent adipose-derived stem (hMADS) cells exhibit a normal karyotype and high self-renewal ability; they are known to differentiate into cells that exhibit the key properties of human white adipocytes, that is, uncoupling protein two expression, insulin-stimulated glucose uptake, lipolysis in response to beta-agonists and atrial natriuretic peptide, and release of adiponectin and leptin. Herein, we show that, upon chronic exposure to a specific PPARgamma but not to a PPARbeta/delta or a PPARalpha agonist, hMADS cell-derived white adipocytes are able to switch to a brown phenotype by expressing both uncoupling protein one (UCP1) and CIDEA mRNA. This switch is accompanied by an increase in oxygen consumption and uncoupling. The expression of UCP1 protein is associated to stimulation of respiration by beta-AR agonists, including beta3-AR agonist. Thus, hMADS cells represent an invaluable cell model to screen for drugs stimulating the formation and/or the uncoupling capacity of human brown adipocytes that could help to dissipate excess caloric intake of individuals.
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Affiliation(s)
- Christian Elabd
- IBDC, Université de Nice Sophia-Antipolis, CNRS, 06 107 Nice cedex 2, France
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13
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Rosso R, Lucioni M. Normal and neoplastic cells of brown adipose tissue express the adhesion molecule CD31. Arch Pathol Lab Med 2006; 130:480-2. [PMID: 16594742 DOI: 10.5858/2006-130-480-nancob] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
CONTEXT CD31 (platelet-endothelial cell adhesion molecule-1; PECAM-1), an adhesion molecule involved in the process of angiogenesis, is used as a marker of normal and neoplastic vascularization. During the assessment of angiogenesis and vascular invasion in a thymic carcinoid tumor, we observed unexpected immunostaining for CD31 in perithymic brown fat nests. OBJECTIVE To determine whether CD31 is expressed by normal and neoplastic cells of brown fat, a tissue whose thermogenetic activity depends heavily on high perfusion. DESIGN Formalin-fixed, paraffin-embedded archival tissues were immunostained by the labeled avidin-biotin method using antibodies against CD31 (clones JC70A and 1A10) after retrieval of heat-induced epitopes. Archival tissues included perithymic, periadrenal, axillary, and neck adipose tissue in which were embedded nests of brown fat (n = 15), hibernoma (n = 3), lipoma (n = 6), well-differentiated liposarcoma (n = 4), and myxoid liposarcoma (n = 4). RESULTS Invariably, multivacuolated and univacuolated adipocytes of normal brown fat and hibernomas were intensely positive for the CD31 antigen. The immunostaining "decorated" cell membranes and the membranes of intracytoplasmic vacuoles. No expression of CD31 was found in normal adipocytes of white fat, in neoplastic cells of lipomas, or in multivacuolated lipoblasts of well-differentiated and myxoid liposarcomas. CONCLUSIONS The spectrum of cell types that express CD31 is expanded to include normal and neoplastic brown fat cells. We speculate that the expression of CD31 may play a role in the development and maintenance of the vascular network characterizing this specialized adipose tissue. Moreover, CD31 may inhibit the Bax-mediated apoptosis of brown fat cells. For practical purposes, CD31 may be used as an immunohistochemical marker for distinguishing between white and brown fat and for diagnosing hibernoma in paraffin sections.
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Affiliation(s)
- Renato Rosso
- From the Department of Pathology, University of Pavia, IRCCS San Matteo Hospital, Pavia, Italy.
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14
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Abstract
The function of brown adipose tissue is to transfer energy from food into heat; physiologically, both the heat produced and the resulting decrease in metabolic efficiency can be of significance. Both the acute activity of the tissue, i.e., the heat production, and the recruitment process in the tissue (that results in a higher thermogenic capacity) are under the control of norepinephrine released from sympathetic nerves. In thermoregulatory thermogenesis, brown adipose tissue is essential for classical nonshivering thermogenesis (this phenomenon does not exist in the absence of functional brown adipose tissue), as well as for the cold acclimation-recruited norepinephrine-induced thermogenesis. Heat production from brown adipose tissue is activated whenever the organism is in need of extra heat, e.g., postnatally, during entry into a febrile state, and during arousal from hibernation, and the rate of thermogenesis is centrally controlled via a pathway initiated in the hypothalamus. Feeding as such also results in activation of brown adipose tissue; a series of diets, apparently all characterized by being low in protein, result in a leptin-dependent recruitment of the tissue; this metaboloregulatory thermogenesis is also under hypothalamic control. When the tissue is active, high amounts of lipids and glucose are combusted in the tissue. The development of brown adipose tissue with its characteristic protein, uncoupling protein-1 (UCP1), was probably determinative for the evolutionary success of mammals, as its thermogenesis enhances neonatal survival and allows for active life even in cold surroundings.
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Affiliation(s)
- Barbara Cannon
- The Wenner-Gren Institute, The Arrhenius Laboratories F3, Stockholm University, Stockholm, Sweden
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Gullicksen PS, Hausman DB, Dean RG, Hartzell DL, Baile CA. Adipose tissue cellularity and apoptosis after intracerebroventricular injections of leptin and 21 days of recovery in rats. Int J Obes (Lond) 2003; 27:302-12. [PMID: 12629556 DOI: 10.1038/sj.ijo.0802205] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
OBJECTIVE To determine the effect of leptin and post-treatment recovery on adipose tissue cellularity and apoptosis. In addition, to investigate whether Bcl-2 and/or Bax is involved in the mechanism of leptin-induced adipose tissue apoptosis. DESIGN A total of 24 adult male Sprague-Dawley rats were injected i.c.v. with either 10 microg mouse leptin or 10 microl vehicle once per day for 4 days. At 24 h after the last injection, one group was killed while the other was monitored for 21 days. MEASUREMENTS DNA fragmentation and Bcl-2 and Bax protein levels were determined in inguinal (ING), epididymal (EPI) and retroperitoneal (RP) white adipose tissues and the interscapular brown adipose tissue (BAT). Cellularity was determined in ING and EPI. RESULTS Leptin significantly reduced the masses of all white fat pads [RPINGEPI] but not BAT. Cell volume was significantly reduced in EPI and ING. Only ING had a significantly reduced cell number from leptin treatment plus exhibited apoptosis by increased DNA fragmentation and DNA laddering, and upregulation of pro-apoptosis Bax protein. The other fat pads exhibited a general trend to increase the Bcl-2/Bax ratio. Recovery allowed for normalization of white fat pad mass, cell number and cell volume; however, BAT mass increased 42% over control. After recovery, apoptosis was not detected, Bcl-2 protein had increased in ING, and the Bcl-2/Bax ratio had risen overall. CONCLUSIONS Central administration of mouse leptin in the rat targets white fat depots individually to reduce mass by a reduction in cell volume plus adipocyte deletion in, at least, the ING fat pad by Bax-mediated apoptosis. Even after a dramatic loss in adipose tissue mass and change in cellularity, the rat demonstrates a resilient return to control levels together with an increase in factors that prevent adipocyte loss.
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Affiliation(s)
- P S Gullicksen
- Department of Food and Nutrition, The University of Georgia, Athens, USA
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16
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Nisoli E, Regianini L, Bulbarelli A, Briscini L, Bracale R, Breacale R, Carruba MO. Protective effects of noradrenaline against tumor necrosis factor-alpha-induced apoptosis in cultured rat brown adipocytes: role of nitric oxide-induced heat shock protein 70 expression. Int J Obes (Lond) 2001; 25:1421-30. [PMID: 11673761 DOI: 10.1038/sj.ijo.0801788] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/21/2000] [Revised: 03/07/2001] [Accepted: 04/20/2001] [Indexed: 11/09/2022]
Abstract
OBJECTIVE To elucidate the effects and molecular mechanism(s) by means of which noradrenaline (NA) protects against the tumor necrosis factor (TNF)-alpha-induced apoptosis of brown adipocytes. DESIGN Brown fat precursor cells were isolated from young rats; 2.5 million cells were added to each 24-well culture plate and cultured in a defined culture medium. On day 8, the cultured cells were exposed to murine recombinant TNF-alpha and/or cycloheximide (CHX; 10 microg/ml) and/or NA and/or nitric oxide (NO) donors and/or the NO synthase inhibitor N(G)-nitro-L-arginine methyl ester (L-NAME) and/or 10 microM heat shock protein 70 (HSP70) antisense or sense oligomers. MEASUREMENTS Analysis of DNA fragmentation on agarose gel as a marker of apoptosis; reverse transcriptase-polymerase chain reaction analysis of mRNA levels; Western blotting analysis of protein levels. RESULTS Pretreatment of primary cultures of rat brown fat cells with micromolar concentrations of NA or the NO-donor S-nitroso-N-acetylpenicillamine (SNAP) induced the expression of HSP70 mRNA and protein, which was associated with cytoprotection against TNF-alpha plus CHX-induced apoptosis. The L-NAME inhibitor of NO synthase activity inhibited both NA-stimulated HSP70 expression and cytoprotection. Furthermore, pretreatment of brown adipocytes with an antisense oligonucleotide to HSP70 antagonized both SNAP- and NA-induced cytoprotection. CONCLUSION These findings demonstrate that the NO produced by NA stimulation can induce resistance to the TNF-alpha-induced apoptosis of brown adipocytes, possibly by means of the expression of HSP70.
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Affiliation(s)
- E Nisoli
- Center for Study and Research on Obesity, Department of Preclinical Sciences, LITA Vialba, L Sacco Hospital, Milan University, Milan, Italy.
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17
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Ursø B, Niesler CU, O'Rahilly S, Siddle K. Comparison of anti-apoptotic signalling by the insulin receptor and IGF-I receptor in preadipocytes and adipocytes. Cell Signal 2001; 13:279-85. [PMID: 11306245 DOI: 10.1016/s0898-6568(01)00130-9] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
We compared the effectiveness of insulin receptor (IR) and type I insulin-like growth factor (IGF) receptor (IGFR) cytoplasmic domains in mediating anti-apoptotic effects in 3T3-L1 preadipocytes and adipocytes. We used TrkC/IR and TrkC/IGFR chimeras, stably expressed in these cells and stimulated with neurotrophin-3 (NT-3), so as to avoid interference from endogenous receptors. After 24-h serum deprivation, 10% of preadipocytes and 2% of adipocytes appeared apoptotic as determined by fluorescence-activated cell sorter (FACS) analysis of cells stained with propidium iodide (PI) and Annexin V. When NT-3 was added, the two chimeras inhibited apoptosis to the same extent by 80% in preadipocytes and 50% in adipocytes. Mutation of juxtamembrane tyrosines (IR Y960F, IGFR Y950F) abrogated these anti-apoptotic effects. Qualitatively similar results were obtained by determination of viable rather than apoptotic cells. We conclude that IR and IGFR have equal potential to inhibit apoptosis in cell backgrounds, which are normally responsive to either IGF-I or insulin.
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Affiliation(s)
- B Ursø
- University of Cambridge, Department of Clinical Biochemistry, Addenbrooke's Hospital, Hills Road, CB2 2QR, Cambridge, UK
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As the proliferation promoter noradrenaline induces expression of ICER (induced cAMP early repressor) in proliferative brown adipocytes, ICER may not be a universal tumour suppressor. Biochem J 2001. [PMID: 11171092 DOI: 10.1042/0264-6021:3540169] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The CREM (cAMP-response-element modulator) gene product ICER (induced cAMP early repressor) has been proposed to function as a tumour (cell proliferation) suppressor. To investigate the generality of this concept, the expression pattern of ICER in brown adipocytes was followed; this was critical because brown adipocytes are one of few cell types in which cAMP is associated positively with cell proliferation but negatively with apoptosis. In response to the physiological stimulus of cold (which induces cell proliferation), ICER mRNA levels were increased in brown adipose tissue in vivo. In brown adipocytes in primary culture, ICER gene expression was induced by noradrenaline (norepinephrine) not only in the mature state (where noradrenaline potentiates differentiation), but also in the proliferative state of the cell cultures (where noradrenaline enhances cell proliferation). The induction was mediated via beta-receptors and the cAMP/protein kinase A pathway. The induced ICER appeared to repress its own expression and that of the beta2-adrenoceptor. It is thus evident that also in cell types in which cAMP induces proliferation, and even when these cells are in the proliferative state, ICER expression is induced by the same agents that stimulate proliferation. This can either mean that ICER is not a general tumour suppressor, or that brown adipocytes temporally or spatially avoid this role of ICER.
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Abstract
The relative stability of body weight over the long term and under a variety of environmental conditions that alter short-term energy intake and expenditure provides strong evidence for the regulation of body energy content. The lipostatic theory of energy balance regulation proposed 40 years ago that circulating factors, generated in proportion to body fat stores, acted as signals to the brain, eliciting changes in energy intake and expenditure. The discovery of leptin and its receptors has now provided a molecular basis for this theory. Leptin functions as much more than an adipocyte-derived signal of lipid stores, however. Although suppression of food intake is an important centrally mediated effect of leptin, considerable evidence indicates that leptin also functions both directly and indirectly, via the brain, to orchestrate complex metabolic changes in a number of organs and tissues, altering nutrient flux to favor energy expenditure over energy storage.
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Affiliation(s)
- C A Baile
- Department of Animal and Dairy Science, University of Georgia, Athens Georgia 30602, USA.
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Thonberg H, Lindgren EM, Nedergaard J, Cannon B. As the proliferation promoter noradrenaline induces expression of ICER (induced cAMP early repressor) in proliferative brown adipocytes, ICER may not be a universal tumour suppressor. Biochem J 2001; 354:169-77. [PMID: 11171092 PMCID: PMC1221641 DOI: 10.1042/bj3540169] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The CREM (cAMP-response-element modulator) gene product ICER (induced cAMP early repressor) has been proposed to function as a tumour (cell proliferation) suppressor. To investigate the generality of this concept, the expression pattern of ICER in brown adipocytes was followed; this was critical because brown adipocytes are one of few cell types in which cAMP is associated positively with cell proliferation but negatively with apoptosis. In response to the physiological stimulus of cold (which induces cell proliferation), ICER mRNA levels were increased in brown adipose tissue in vivo. In brown adipocytes in primary culture, ICER gene expression was induced by noradrenaline (norepinephrine) not only in the mature state (where noradrenaline potentiates differentiation), but also in the proliferative state of the cell cultures (where noradrenaline enhances cell proliferation). The induction was mediated via beta-receptors and the cAMP/protein kinase A pathway. The induced ICER appeared to repress its own expression and that of the beta2-adrenoceptor. It is thus evident that also in cell types in which cAMP induces proliferation, and even when these cells are in the proliferative state, ICER expression is induced by the same agents that stimulate proliferation. This can either mean that ICER is not a general tumour suppressor, or that brown adipocytes temporally or spatially avoid this role of ICER.
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Affiliation(s)
- H Thonberg
- The Wenner-Gren Institute, The Arrhenius Laboratories F3, Stockholm University, SE-106 91 Stockholm, Sweden
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21
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Giordano A, Nisoli E, Tonello C, Cancello R, Carruba MO, Cinti S. Expression and distribution of heme oxygenase-1 and -2 in rat brown adipose tissue: the modulatory role of the noradrenergic system. FEBS Lett 2000; 487:171-5. [PMID: 11150503 DOI: 10.1016/s0014-5793(00)02217-1] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
To investigate whether brown adipose tissue (BAT) expresses the inducible (HO-1) and the constitutive (HO-2) isoform of heme oxygenase, reverse transcriptase-polymerase chain reaction, Western blotting and immunohistochemistry were performed on interscapular BAT (IBAT) from rats acclimated at environmental temperature or exposed to cold. Both HO isoforms were detected in rat IBAT. They were immunolocalized in the cytoplasm and/or nuclei of brown adipocytes, in parenchymal capillaries, arteries and in some veins and nerves. Whereas cold exposure did not affect HO-2 expression, it significantly increased the expression of HO-1, both at mRNA (about 3-fold) and protein (about 2-fold) levels, reflecting the increased expression of HO-1 in the brown adipocytes and endothelial cells of parenchymal capillaries. Western blotting of cytosolic and nuclear protein extracts from cultured differentiated brown adipocytes showed that HO-1 and HO-2 are indeed localized in the cytosol and nuclei of brown adipocytes, and that noradrenaline stimulation significantly increased their amount in cytosol but not in the nuclear fraction.
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Affiliation(s)
- A Giordano
- Institute of Normal Human Morphology-Anatomy, Faculty of Medicine, University of Ancona, Italy
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Valladares A, Porras A, Alvarez AM, Roncero C, Benito M. Noradrenaline induces brown adipocytes cell growth via beta-receptors by a mechanism dependent on ERKs but independent of cAMP and PKA. J Cell Physiol 2000; 185:324-30. [PMID: 11056002 DOI: 10.1002/1097-4652(200012)185:3<324::aid-jcp2>3.0.co;2-q] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
It has been well established that the key role of noradrenaline is the induction of uncoupling-protein-1 (UCP-1) expression, the unique marker of brown adipocytes. However, its implication on proliferation and the pathways involved are not as well characterized. By using rat fetal brown adipocytes as a model, we show that, although noradrenaline activates extracellular regulated kinases (ERKs) through beta-, alpha1-, and alpha2-receptors, only beta-receptors mediate cell growth by a mechanism that requires ERKs activation but is independent of cyclic-adenosine-monophosphate/protein kinase A (cAMP/PKA). Conversely, the cAMP/PKA cascade mediates noradrenaline-induced UCP-1 expression, whereas ERKs pathway attenuates thermogenic differentiation. On the other hand, alpha1- and alpha2-receptors have an antiproliferative effect that is enhanced by ERK inhibition.
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Affiliation(s)
- A Valladares
- Departamento de Bioquímica y Biología Molecular II, Instituto de Bioquímica, Centro Mixto del Consejo Superior de Investigaciones Científicas y de la Universidad Complutense de Madrid, Madrid, Spain.
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