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Zhang J, Kibret BG, Vatner DE, Vatner SF. The role of brown adipose tissue in mediating healthful longevity. THE JOURNAL OF CARDIOVASCULAR AGING 2024; 4:17. [PMID: 39119146 PMCID: PMC11309368 DOI: 10.20517/jca.2024.01] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 08/10/2024]
Abstract
There are two major subtypes of adipose tissue, i.e., white adipose tissue (WAT) and brown adipose tissue (BAT). It has been known for a long time that WAT mediates obesity and impairs healthful longevity. More recently, interest has focused on BAT, which, unlike WAT, actually augments healthful aging. The goal of this review is to examine the role of BAT in mediating healthful longevity. A major role for BAT and its related beige adipose tissue is thermogenesis, as a mechanism to maintain body temperature by producing heat through uncoupling protein 1 (UCP1) or through UCP1-independent thermogenic pathways. Our hypothesis is that healthful longevity is, in part, mediated by BAT. BAT protects against the major causes of impaired healthful longevity, i.e., obesity, diabetes, cardiovascular disorders, cancer, Alzheimer's disease, reduced exercise tolerance, and impaired blood flow. Several genetically engineered mouse models have shown that BAT enhances healthful aging and that their BAT is more potent than wild-type (WT) BAT. For example, when BAT, which increases longevity and exercise performance in mice with disruption of the regulator of G protein signaling 14 (RGS14), is transplanted to WT mice, their exercise capacity is enhanced at 3 days after BAT transplantation, whereas BAT transplantation from WT to WT mice also resulted in increased exercise performance, but only at 8 weeks after transplantation. In view of the ability of BAT to mediate healthful longevity, it is likely that a pharmaceutical analog of BAT will become a novel therapeutic modality.
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Affiliation(s)
- Jie Zhang
- Department of Cell Biology and Molecular Medicine, Rutgers, New Jersey Medical School, Newark, NJ 07103, USA
| | - Berhanu Geresu Kibret
- Department of Cell Biology and Molecular Medicine, Rutgers, New Jersey Medical School, Newark, NJ 07103, USA
| | - Dorothy E. Vatner
- Department of Medicine, Rutgers, New Jersey Medical School, Newark, NJ 07103, USA
| | - Stephen F. Vatner
- Department of Cell Biology and Molecular Medicine, Rutgers, New Jersey Medical School, Newark, NJ 07103, USA
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Ten Hove AS, Mallesh S, Zafeiropoulou K, de Kleer JWM, van Hamersveld PHP, Welting O, Hakvoort TBM, Wehner S, Seppen J, de Jonge WJ. Sympathetic activity regulates epithelial proliferation and wound healing via adrenergic receptor α 2A. Sci Rep 2023; 13:17990. [PMID: 37863979 PMCID: PMC10589335 DOI: 10.1038/s41598-023-45160-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2023] [Accepted: 10/17/2023] [Indexed: 10/22/2023] Open
Abstract
Innervation of the intestinal mucosa by the sympathetic nervous system is well described but the effects of adrenergic receptor stimulation on the intestinal epithelium remain equivocal. We therefore investigated the effect of sympathetic neuronal activation on intestinal cells in mouse models and organoid cultures, to identify the molecular routes involved. Using publicly available single-cell RNA sequencing datasets we show that the α2A isoform is the most abundant adrenergic receptor in small intestinal epithelial cells. Stimulation of this receptor with norepinephrine or a synthetic specific α2A receptor agonist promotes epithelial proliferation and stem cell function, while reducing differentiation in vivo and in intestinal organoids. In an anastomotic healing mouse model, adrenergic receptor α2A stimulation resulted in improved anastomotic healing, while surgical sympathectomy augmented anastomotic leak. Furthermore, stimulation of this receptor led to profound changes in the microbial composition, likely because of altered epithelial antimicrobial peptide secretion. Thus, we established that adrenergic receptor α2A is the molecular delegate of intestinal epithelial sympathetic activity controlling epithelial proliferation, differentiation, and host defense. Therefore, this receptor could serve as a newly identified molecular target to improve mucosal healing in intestinal inflammation and wounding.
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Affiliation(s)
- Anne S Ten Hove
- Tytgat Institute for Liver and Intestinal Research, Gastroenterology and Hepatology, Amsterdam Gastroenterology Endocrinology Metabolism, Amsterdam UMC, University of Amsterdam, Meibergdreef 69-71, 1105 BK, Amsterdam, The Netherlands.
| | - Shilpashree Mallesh
- Department of General, Visceral-, Thoracic and Vascular Surgery, University Hospital Bonn, Bonn, Germany
| | - Konstantina Zafeiropoulou
- Tytgat Institute for Liver and Intestinal Research, Gastroenterology and Hepatology, Amsterdam Gastroenterology Endocrinology Metabolism, Amsterdam UMC, University of Amsterdam, Meibergdreef 69-71, 1105 BK, Amsterdam, The Netherlands
| | - Janna W M de Kleer
- Tytgat Institute for Liver and Intestinal Research, Gastroenterology and Hepatology, Amsterdam Gastroenterology Endocrinology Metabolism, Amsterdam UMC, University of Amsterdam, Meibergdreef 69-71, 1105 BK, Amsterdam, The Netherlands
| | - Patricia H P van Hamersveld
- Tytgat Institute for Liver and Intestinal Research, Gastroenterology and Hepatology, Amsterdam Gastroenterology Endocrinology Metabolism, Amsterdam UMC, University of Amsterdam, Meibergdreef 69-71, 1105 BK, Amsterdam, The Netherlands
| | - Olaf Welting
- Tytgat Institute for Liver and Intestinal Research, Gastroenterology and Hepatology, Amsterdam Gastroenterology Endocrinology Metabolism, Amsterdam UMC, University of Amsterdam, Meibergdreef 69-71, 1105 BK, Amsterdam, The Netherlands
| | - Theodorus B M Hakvoort
- Tytgat Institute for Liver and Intestinal Research, Gastroenterology and Hepatology, Amsterdam Gastroenterology Endocrinology Metabolism, Amsterdam UMC, University of Amsterdam, Meibergdreef 69-71, 1105 BK, Amsterdam, The Netherlands
| | - Sven Wehner
- Department of General, Visceral-, Thoracic and Vascular Surgery, University Hospital Bonn, Bonn, Germany
| | - Jurgen Seppen
- Tytgat Institute for Liver and Intestinal Research, Gastroenterology and Hepatology, Amsterdam Gastroenterology Endocrinology Metabolism, Amsterdam UMC, University of Amsterdam, Meibergdreef 69-71, 1105 BK, Amsterdam, The Netherlands
| | - Wouter J de Jonge
- Tytgat Institute for Liver and Intestinal Research, Gastroenterology and Hepatology, Amsterdam Gastroenterology Endocrinology Metabolism, Amsterdam UMC, University of Amsterdam, Meibergdreef 69-71, 1105 BK, Amsterdam, The Netherlands.
- Department of General, Visceral-, Thoracic and Vascular Surgery, University Hospital Bonn, Bonn, Germany.
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Rösch G, Muschter D, Taheri S, El Bagdadi K, Dorn C, Meurer A, Zaucke F, Schilling AF, Grässel S, Straub RH, Jenei-Lanzl Z. β2-Adrenoceptor Deficiency Results in Increased Calcified Cartilage Thickness and Subchondral Bone Remodeling in Murine Experimental Osteoarthritis. Front Immunol 2022; 12:801505. [PMID: 35095883 PMCID: PMC8794706 DOI: 10.3389/fimmu.2021.801505] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Accepted: 12/22/2021] [Indexed: 12/12/2022] Open
Abstract
Purpose Recent studies demonstrated a contribution of adrenoceptors (ARs) to osteoarthritis (OA) pathogenesis. Several AR subtypes are expressed in joint tissues and the β2-AR subtype seems to play a major role during OA progression. However, the importance of β2-AR has not yet been investigated in knee OA. Therefore, we examined the development of knee OA in β2-AR-deficient (Adrb2-/-) mice after surgical OA induction. Methods OA was induced by destabilization of the medial meniscus (DMM) in male wildtype (WT) and Adrb2-/- mice. Cartilage degeneration and synovial inflammation were evaluated by histological scoring. Subchondral bone remodeling was analyzed using micro-CT. Osteoblast (alkaline phosphatase - ALP) and osteoclast (cathepsin K - CatK) activity were analyzed by immunostainings. To evaluate β2-AR deficiency-associated effects, body weight, sympathetic tone (splenic norepinephrine (NE) via HPLC) and serum leptin levels (ELISA) were determined. Expression of the second major AR, the α2-AR, was analyzed in joint tissues by immunostaining. Results WT and Adrb2-/- DMM mice developed comparable changes in cartilage degeneration and synovial inflammation. Adrb2-/- DMM mice displayed elevated calcified cartilage and subchondral bone plate thickness as well as increased epiphyseal BV/TV compared to WTs, while there were no significant differences in Sham animals. In the subchondral bone of Adrb2-/- mice, osteoblasts activity increased and osteoclast activity deceased. Adrb2-/- mice had significantly higher body weight and fat mass compared to WT mice. Serum leptin levels increased in Adrb2-/- DMM compared to WT DMM without any difference between the respective Shams. There was no difference in the development of meniscal ossicles and osteophytes or in the subarticular trabecular microstructure between Adrb2-/- and WT DMM as well as Adrb2-/- and WT Sham mice. Number of α2-AR-positive cells was lower in Adrb2-/- than in WT mice in all analyzed tissues and decreased in both Adrb2-/- and WT over time. Conclusion We propose that the increased bone mass in Adrb2-/- DMM mice was not only due to β2-AR deficiency but to a synergistic effect of OA and elevated leptin concentrations. Taken together, β2-AR plays a major role in OA-related subchondral bone remodeling and is thus an attractive target for the exploration of novel therapeutic avenues.
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Affiliation(s)
- Gundula Rösch
- Dr. Rolf M. Schwiete Research Unit for Osteoarthritis, Department of Orthopedics (Friedrichsheim), University Hospital Frankfurt, Goethe University, Frankfurt am Main, Germany
| | - Dominique Muschter
- Department of Orthopedic Surgery, Experimental Orthopedics, Centre for Medical Biotechnology, University of Regensburg, Regensburg, Germany
| | - Shahed Taheri
- Department of Trauma Surgery, Orthopedic Surgery and Plastic Surgery, Universitätsmedizin Göttingen, Göttingen, Germany
| | - Karima El Bagdadi
- Dr. Rolf M. Schwiete Research Unit for Osteoarthritis, Department of Orthopedics (Friedrichsheim), University Hospital Frankfurt, Goethe University, Frankfurt am Main, Germany
| | - Christoph Dorn
- Institute of Pharmacy, University of Regensburg, Regensburg, Germany
| | - Andrea Meurer
- Dr. Rolf M. Schwiete Research Unit for Osteoarthritis, Department of Orthopedics (Friedrichsheim), University Hospital Frankfurt, Goethe University, Frankfurt am Main, Germany
| | - Frank Zaucke
- Dr. Rolf M. Schwiete Research Unit for Osteoarthritis, Department of Orthopedics (Friedrichsheim), University Hospital Frankfurt, Goethe University, Frankfurt am Main, Germany
| | - Arndt F Schilling
- Department of Trauma Surgery, Orthopedic Surgery and Plastic Surgery, Universitätsmedizin Göttingen, Göttingen, Germany
| | - Susanne Grässel
- Department of Orthopedic Surgery, Experimental Orthopedics, Centre for Medical Biotechnology, University of Regensburg, Regensburg, Germany
| | - Rainer H Straub
- Laboratory of Experimental Rheumatology and Neuroendocrine Immunology, Department of Internal Medicine, University Hospital Regensburg, Regensburg, Germany
| | - Zsuzsa Jenei-Lanzl
- Dr. Rolf M. Schwiete Research Unit for Osteoarthritis, Department of Orthopedics (Friedrichsheim), University Hospital Frankfurt, Goethe University, Frankfurt am Main, Germany
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Choi RY, Lee MK. Polygonum multiflorum Thunb. Hot Water Extract Reverses High-Fat Diet-Induced Lipid Metabolism of White and Brown Adipose Tissues in Obese Mice. PLANTS (BASEL, SWITZERLAND) 2021; 10:plants10081509. [PMID: 34451554 PMCID: PMC8398201 DOI: 10.3390/plants10081509] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Revised: 07/11/2021] [Accepted: 07/21/2021] [Indexed: 05/06/2023]
Abstract
The purpose of the present study was to determine whether an anti-obesity effect of a Polygonum multiflorum Thunb. hot water extract (PW) was involved in the lipid metabolism of white adipose tissue (WAT) and brown adipose tissue (BAT) in high-fat diet (HFD)-induced C57BL/6N obese mice. Mice freely received a normal diet (NCD) or an HFD for 12 weeks; HFD-fed mice were orally given PW (100 or 300 mg/kg) or garcinia cambogia (GC, 200 mg/kg) once a day. After 12 weeks, PW (300 mg/kg) or GC significantly alleviated adiposity by reducing body weight, WAT weights, and food efficiency ratio. PW (300 mg/kg) improved hyperinsulinemia and enhanced insulin sensitivity. In addition, PW (300 mg/kg) significantly down-regulated expression of carbohydrate-responsive element-binding protein (ChREBP) and diacylglycerol O-acyltransferase 2 (DGAT2) genes in WAT compared with the untreated HFD group. HFD increased BAT gene levels such as adrenoceptor beta 3 (ADRB3), peroxisome proliferator-activated receptor γ (PPARγ), hormone-sensitive lipase (HSL), cluster of differentiation 36 (CD36), fatty acid-binding protein 4 (FABP4), PPARγ coactivator 1-α (PGC-1α), PPARα, and carnitine palmitoyltransferase 1B (CPT1B) compared with the NCD group; however, PW or GC effectively reversed those levels. These findings suggest that the anti-obesity activity of PW was mediated via suppression of lipogenesis in WAT, leading to the normalization of lipid metabolism in BAT.
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Affiliation(s)
- Ra-Yeong Choi
- Department of Agricultural Biology, National Institute of Agricultural Sciences, Rural Development Administration, Wanju 55365, Korea;
| | - Mi-Kyung Lee
- Department of Food and Nutrition, Sunchon National University, Suncheon 57922, Korea
- Correspondence: ; Tel.: +82-61-750-3656; Fax: +82-61-750-3650
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Perez DM. Current Developments on the Role of α 1-Adrenergic Receptors in Cognition, Cardioprotection, and Metabolism. Front Cell Dev Biol 2021; 9:652152. [PMID: 34113612 PMCID: PMC8185284 DOI: 10.3389/fcell.2021.652152] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Accepted: 04/29/2021] [Indexed: 12/13/2022] Open
Abstract
The α1-adrenergic receptors (ARs) are G-protein coupled receptors that bind the endogenous catecholamines, norepinephrine, and epinephrine. They play a key role in the regulation of the sympathetic nervous system along with β and α2-AR family members. While all of the adrenergic receptors bind with similar affinity to the catecholamines, they can regulate different physiologies and pathophysiologies in the body because they couple to different G-proteins and signal transduction pathways, commonly in opposition to one another. While α1-AR subtypes (α1A, α1B, α1C) have long been known to be primary regulators of vascular smooth muscle contraction, blood pressure, and cardiac hypertrophy, their role in neurotransmission, improving cognition, protecting the heart during ischemia and failure, and regulating whole body and organ metabolism are not well known and are more recent developments. These advancements have been made possible through the development of transgenic and knockout mouse models and more selective ligands to advance their research. Here, we will review the recent literature to provide new insights into these physiological functions and possible use as a therapeutic target.
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Affiliation(s)
- Dianne M Perez
- The Lerner Research Institute, The Cleveland Clinic Foundation, Cleveland, OH, United States
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Åslund A, Bokhari MH, Wetterdal E, Martin R, Knölker HJ, Bengtsson T. Myosin 1c: A novel regulator of glucose uptake in brown adipocytes. Mol Metab 2021; 53:101247. [PMID: 33965643 PMCID: PMC8182130 DOI: 10.1016/j.molmet.2021.101247] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/03/2021] [Revised: 04/26/2021] [Accepted: 05/03/2021] [Indexed: 12/02/2022] Open
Abstract
Objective The potential of brown adipose tissue (BAT) to influence energy homeostasis in animals and humans is encouraging as this tissue can increase fatty acid and glucose utilization to produce heat through uncoupling protein 1 (UCP1), but the actual mechanism of how the cell regulates glucose uptake is not fully understood. Myosin 1c (Myo1c) is an unconventional motor protein involved in several cellular processes, including insulin-mediated glucose uptake via GLUT4 vesicle fusion in white adipocytes, but its role in glucose uptake in BAT has not previously been investigated. Methods Using the specific inhibitor pentachloropseudilin (PClP), a neutralizing antibody assay, and siRNA, we examined the role of Myo1c in mechanisms leading to glucose uptake both in vitro in isolated mouse primary adipocytes and in vivo in mice. Results Our results show that inhibition of Myo1c removes insulin-stimulated glucose uptake in white adipocytes, while inducing glucose uptake in brown adipocytes, independent of GLUT4, by increasing the expression, translation, and translocation of GLUT1 to the plasma membrane. Inhibition of Myo1c leads to the activation of PKA and downstream substrates p38 and ATF-2, which are known to be involved in the expression of β-adrenergic genes. Conclusions Myo1c is a PKA repressor and regulates glucose uptake into BAT. Myo1c is a BAT-specific regulator of glucose uptake. Myo1c inhibition leads to increased expression, translation, and translocation of GLUT1. Myo1c inhibition results in increased activation of PKA and its downstream targets.
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Affiliation(s)
- Alice Åslund
- Department of Molecular Biosciences, Wenner-Gren Institute, Stockholm University, SE-106 91, Stockholm, Sweden
| | - Muhammad Hamza Bokhari
- Department of Molecular Biosciences, Wenner-Gren Institute, Stockholm University, SE-106 91, Stockholm, Sweden
| | - Erika Wetterdal
- Department of Molecular Biosciences, Wenner-Gren Institute, Stockholm University, SE-106 91, Stockholm, Sweden
| | - René Martin
- Faculty of Chemistry, Technical University of Dresden, Bergstrasse 66, 01069, Dresden, Germany
| | - Hans-Joachim Knölker
- Faculty of Chemistry, Technical University of Dresden, Bergstrasse 66, 01069, Dresden, Germany
| | - Tore Bengtsson
- Department of Molecular Biosciences, Wenner-Gren Institute, Stockholm University, SE-106 91, Stockholm, Sweden.
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Im H, Park JH, Im S, Han J, Kim K, Lee YH. Regulatory roles of G-protein coupled receptors in adipose tissue metabolism and their therapeutic potential. Arch Pharm Res 2021; 44:133-145. [PMID: 33550564 PMCID: PMC7907040 DOI: 10.1007/s12272-021-01314-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2020] [Accepted: 01/18/2021] [Indexed: 12/12/2022]
Abstract
The high incidence of obesity has increased the need to discover new therapeutic targets to combat obesity and obesity-related metabolic diseases. Obesity is defined as an abnormal accumulation of adipose tissue, which is one of the major metabolic organs that regulate energy homeostasis. However, there are currently no approved anti-obesity therapeutics that directly target adipose tissue metabolism. With recent advances in the understanding of adipose tissue biology, molecular mechanisms involved in brown adipose tissue expansion and metabolic activation have been investigated as potential therapeutic targets to increase energy expenditure. This review focuses on G-protein coupled receptors (GPCRs) as they are the most successful class of druggable targets in human diseases and have an important role in regulating adipose tissue metabolism. We summarize recent findings on the major GPCR classes that regulate thermogenesis and mitochondrial metabolism in adipose tissue. Improved understanding of GPCR signaling pathways that regulate these processes could facilitate the development of novel pharmacological approaches to treat obesity and related metabolic disorders.
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Affiliation(s)
- Hyeonyeong Im
- College of Pharmacy and Research Institute of Pharmaceutical Sciences, Seoul National University; Bio-MAX Institute, Seoul National University, 29-Room # 311, 1 Gwanak-ro, Gwanak-gu, Seoul, 08826, Republic of Korea
| | - Ji-Hyun Park
- College of Pharmacy and Research Institute of Pharmaceutical Sciences, Seoul National University; Bio-MAX Institute, Seoul National University, 29-Room # 311, 1 Gwanak-ro, Gwanak-gu, Seoul, 08826, Republic of Korea
| | - Seowoo Im
- College of Pharmacy and Research Institute of Pharmaceutical Sciences, Seoul National University; Bio-MAX Institute, Seoul National University, 29-Room # 311, 1 Gwanak-ro, Gwanak-gu, Seoul, 08826, Republic of Korea
| | - Juhyeong Han
- College of Pharmacy and Research Institute of Pharmaceutical Sciences, Seoul National University; Bio-MAX Institute, Seoul National University, 29-Room # 311, 1 Gwanak-ro, Gwanak-gu, Seoul, 08826, Republic of Korea
| | - Kyungmin Kim
- College of Pharmacy and Research Institute of Pharmaceutical Sciences, Seoul National University; Bio-MAX Institute, Seoul National University, 29-Room # 311, 1 Gwanak-ro, Gwanak-gu, Seoul, 08826, Republic of Korea
| | - Yun-Hee Lee
- College of Pharmacy and Research Institute of Pharmaceutical Sciences, Seoul National University; Bio-MAX Institute, Seoul National University, 29-Room # 311, 1 Gwanak-ro, Gwanak-gu, Seoul, 08826, Republic of Korea.
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Van Schaik L, Kettle C, Green R, Irving HR, Rathner JA. Effects of Caffeine on Brown Adipose Tissue Thermogenesis and Metabolic Homeostasis: A Review. Front Neurosci 2021; 15:621356. [PMID: 33613184 PMCID: PMC7889509 DOI: 10.3389/fnins.2021.621356] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2020] [Accepted: 01/11/2021] [Indexed: 12/11/2022] Open
Abstract
The impact of brown adipose tissue (BAT) metabolism on understanding energy balance in humans is a relatively new and exciting field of research. The pathogenesis of obesity can be largely explained by an imbalance between caloric intake and energy expenditure, but the underlying mechanisms are far more complex. Traditional non-selective sympathetic activators have been used to artificially elevate energy utilization, or suppress appetite, however undesirable side effects are apparent with the use of these pharmacological interventions. Understanding the role of BAT, in relation to human energy homeostasis has the potential to dramatically offset the energy imbalance associated with obesity. This review discusses paradoxical effects of caffeine on peripheral adenosine receptors and the possible role of adenosine in increasing metabolism is highlighted, with consideration to the potential of central rather than peripheral mechanisms for caffeine mediated BAT thermogenesis and energy expenditure. Research on the complex physiology of adipose tissue, the embryonic lineage and function of the different types of adipocytes is summarized. In addition, the effect of BAT on overall human metabolism and the extent of the associated increase in energy expenditure are discussed. The controversy surrounding the primary β-adrenoceptor involved in human BAT activation is examined, and suggestions as to the lack of translational findings from animal to human physiology and human in vitro to in vivo models are provided. This review compares and distinguishes human and rodent BAT effects, thus developing an understanding of human BAT thermogenesis to aid lifestyle interventions targeting obesity and metabolic syndrome. The focus of this review is on the effect of BAT thermogenesis on overall metabolism, and the potential therapeutic effects of caffeine in increasing metabolism via its effects on BAT.
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Affiliation(s)
- Lachlan Van Schaik
- Department of Pharmacy and Biomedical Sciences, La Trobe Institute for Molecular Science, La Trobe University, Bendigo, VIC, Australia
| | - Christine Kettle
- Department of Pharmacy and Biomedical Sciences, La Trobe Institute for Molecular Science, La Trobe University, Bendigo, VIC, Australia
| | - Rodney Green
- Department of Pharmacy and Biomedical Sciences, La Trobe Institute for Molecular Science, La Trobe University, Bendigo, VIC, Australia
| | - Helen R. Irving
- Department of Pharmacy and Biomedical Sciences, La Trobe Institute for Molecular Science, La Trobe University, Bendigo, VIC, Australia
| | - Joseph A. Rathner
- Department of Pharmacy and Biomedical Sciences, La Trobe Institute for Molecular Science, La Trobe University, Bendigo, VIC, Australia
- Department of Physiology, School of Biomedical Sciences, The University of Melbourne, Melbourne, VIC, Australia
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Dehvari N, Sato M, Bokhari MH, Kalinovich A, Ham S, Gao J, Nguyen HTM, Whiting L, Mukaida S, Merlin J, Chia LY, Wootten D, Summers RJ, Evans BA, Bengtsson T, Hutchinson DS. The metabolic effects of mirabegron are mediated primarily by β 3 -adrenoceptors. Pharmacol Res Perspect 2020; 8:e00643. [PMID: 32813332 PMCID: PMC7437350 DOI: 10.1002/prp2.643] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Revised: 07/16/2020] [Accepted: 07/19/2020] [Indexed: 12/19/2022] Open
Abstract
The β3 -adrenoceptor agonist mirabegron is approved for use for overactive bladder and has been purported to be useful in the treatment of obesity-related metabolic diseases in humans, including those involving disturbances of glucose homeostasis. We investigated the effect of mirabegron on glucose homeostasis with in vitro and in vivo models, focusing on its selectivity at β-adrenoceptors, ability to cause browning of white adipocytes, and the role of UCP1 in glucose homeostasis. In mouse brown, white, and brite adipocytes, mirabegron-mediated effects were examined on cyclic AMP, UCP1 mRNA, [3 H]-2-deoxyglucose uptake, cellular glycolysis, and O2 consumption. Mirabegron increased cyclic AMP levels, UCP1 mRNA content, glucose uptake, and cellular glycolysis in brown adipocytes, and these effects were either absent or reduced in white adipocytes. In brite adipocytes, mirabegron increased cyclic AMP levels and UCP1 mRNA content resulting in increased UCP1-mediated oxygen consumption, glucose uptake, and cellular glycolysis. The metabolic effects of mirabegron in both brown and brite adipocytes were primarily due to actions at β3 -adrenoceptors as they were largely absent in adipocytes derived from β3 -adrenoceptor knockout mice. In vivo, mirabegron increased whole body oxygen consumption, glucose uptake into brown and inguinal white adipose tissue, and improved glucose tolerance, all effects that required the presence of the β3 -adrenoceptor. Furthermore, in UCP1 knockout mice, the effects of mirabegron on glucose tolerance were attenuated. Thus, mirabegron had effects on cellular metabolism in adipocytes that improved glucose handling in vivo, and were primarily due to actions at the β3 -adrenoceptor.
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Affiliation(s)
- Nodi Dehvari
- Department of Molecular BiosciencesThe Wenner‐Gren InstituteStockholm UniversityStockholmSweden
| | - Masaaki Sato
- Drug Discovery BiologyMonash Institute of Pharmaceutical SciencesMonash UniversityParkvilleVic.Australia
| | - Muhammad Hamza Bokhari
- Department of Molecular BiosciencesThe Wenner‐Gren InstituteStockholm UniversityStockholmSweden
| | - Anastasia Kalinovich
- Department of Molecular BiosciencesThe Wenner‐Gren InstituteStockholm UniversityStockholmSweden
| | - Seungmin Ham
- Drug Discovery BiologyMonash Institute of Pharmaceutical SciencesMonash UniversityParkvilleVic.Australia
| | - Jie Gao
- Drug Discovery BiologyMonash Institute of Pharmaceutical SciencesMonash UniversityParkvilleVic.Australia
| | - Huong T. M. Nguyen
- Drug Discovery BiologyMonash Institute of Pharmaceutical SciencesMonash UniversityParkvilleVic.Australia
| | - Lynda Whiting
- Drug Discovery BiologyMonash Institute of Pharmaceutical SciencesMonash UniversityParkvilleVic.Australia
| | - Saori Mukaida
- Drug Discovery BiologyMonash Institute of Pharmaceutical SciencesMonash UniversityParkvilleVic.Australia
| | - Jon Merlin
- Drug Discovery BiologyMonash Institute of Pharmaceutical SciencesMonash UniversityParkvilleVic.Australia
| | - Ling Yeong Chia
- Drug Discovery BiologyMonash Institute of Pharmaceutical SciencesMonash UniversityParkvilleVic.Australia
| | - Denise Wootten
- Drug Discovery BiologyMonash Institute of Pharmaceutical SciencesMonash UniversityParkvilleVic.Australia
| | - Roger J. Summers
- Drug Discovery BiologyMonash Institute of Pharmaceutical SciencesMonash UniversityParkvilleVic.Australia
| | - Bronwyn A. Evans
- Drug Discovery BiologyMonash Institute of Pharmaceutical SciencesMonash UniversityParkvilleVic.Australia
| | - Tore Bengtsson
- Department of Molecular BiosciencesThe Wenner‐Gren InstituteStockholm UniversityStockholmSweden
| | - Dana S. Hutchinson
- Drug Discovery BiologyMonash Institute of Pharmaceutical SciencesMonash UniversityParkvilleVic.Australia
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Olsen JM, Åslund A, Bokhari MH, Hutchinson DS, Bengtsson T. Acute β-adrenoceptor mediated glucose clearance in brown adipose tissue; a distinct pathway independent of functional insulin signaling. Mol Metab 2019; 30:240-249. [PMID: 31767175 PMCID: PMC6838983 DOI: 10.1016/j.molmet.2019.10.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/13/2019] [Revised: 10/07/2019] [Accepted: 10/12/2019] [Indexed: 12/24/2022] Open
Abstract
Objective β-adrenoceptor mediated activation of brown adipose tissue (BAT) has been associated with improvements in metabolic health in models of type 2 diabetes and obesity due to its unique ability to increase whole body energy expenditure, and rate of glucose and free fatty acid disposal. While the thermogenic arm of this phenomenon has been studied in great detail, the underlying mechanisms involved in β-adrenoceptor mediated glucose uptake in BAT are relatively understudied. As β-adrenoceptor agonist administration results in increased hepatic gluconeogenesis that can consequently result in secondary pancreatic insulin release, there is uncertainty regarding the importance of insulin and the subsequent activation of its downstream effectors in mediating β-adrenoceptor stimulated glucose uptake in BAT. Therefore, in this study, we made an effort to discriminate between the two pathways and address whether the insulin signaling pathway is dispensable for the effects of β-adrenoceptor activation on glucose uptake in BAT. Methods Using a specific inhibitor of phosphoinositide 3-kinase α (PI3Kα), which effectively inhibits the insulin signaling pathway, we examined the effects of various β-adrenoceptor agonists, including the physiological endogenous agonist norepinephrine on glucose uptake and respiration in mouse brown adipocytes in vitro and on glucose clearance in mice in vivo. Results PI3Kα inhibition in mouse primary brown adipocytes in vitro, did not inhibit β-adrenoceptor stimulated glucose uptake, GLUT1 synthesis, GLUT1 translocation or respiration. Furthermore, β-adrenoceptor mediated glucose clearance in vivo did not require insulin or Akt activation but was attenuated upon administration of a β3-adrenoceptor antagonist. Conclusions We conclude that the β-adrenergic pathway is still functionally intact upon the inhibition of PI3Kα, showing that the activation of downstream insulin effectors is not required for the acute effects of β-adrenoceptor agonists on glucose homeostasis or thermogenesis. PI3Kα/Akt are dispensable for β-AR mediated glucose clearance in vivo. PI3Kα inhibition in brown adipocytes does not inhibit GLUT1 synthesis/translocation. Acute β-AR induced thermogenesis in brown adipocytes is independent of PI3Kα/Akt. Glucose uptake in brown adipocytes does not require a functional insulin pathway.
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Affiliation(s)
- Jessica M Olsen
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, SE-106 91, Stockholm, Sweden
| | - Alice Åslund
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, SE-106 91, Stockholm, Sweden
| | - Muhammad Hamza Bokhari
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, SE-106 91, Stockholm, Sweden
| | - Dana S Hutchinson
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, 3052, Australia
| | - Tore Bengtsson
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, SE-106 91, Stockholm, Sweden.
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11
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Chia LY, Evans BA, Mukaida S, Bengtsson T, Hutchinson DS, Sato M. Adrenoceptor regulation of the mechanistic target of rapamycin in muscle and adipose tissue. Br J Pharmacol 2019; 176:2433-2448. [PMID: 30740664 PMCID: PMC6592864 DOI: 10.1111/bph.14616] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2018] [Revised: 01/08/2019] [Accepted: 01/21/2019] [Indexed: 12/16/2022] Open
Abstract
A vital role of adrenoceptors in metabolism and energy balance has been well documented in the heart, skeletal muscle, and adipose tissue. It has been only recently demonstrated, however, that activation of the mechanistic target of rapamycin (mTOR) makes a significant contribution to various metabolic and physiological responses to adrenoceptor agonists. mTOR exists as two distinct complexes named mTOR complex 1 (mTORC1) and mTOR complex 2 (mTORC2) and has been shown to play a critical role in protein synthesis, cell proliferation, hypertrophy, mitochondrial function, and glucose uptake. This review will describe the physiological significance of mTORC1 and 2 as a novel paradigm of adrenoceptor signalling in the heart, skeletal muscle, and adipose tissue. Understanding the detailed signalling cascades of adrenoceptors and how they regulate physiological responses is important for identifying new therapeutic targets and identifying novel therapeutic interventions. LINKED ARTICLES: This article is part of a themed section on Adrenoceptors-New Roles for Old Players. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v176.14/issuetoc.
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Affiliation(s)
- Ling Yeong Chia
- Drug Discovery Biology, Monash Institute of Pharmaceutical SciencesMonash UniversityMelbourneVictoriaAustralia
| | - Bronwyn A. Evans
- Drug Discovery Biology, Monash Institute of Pharmaceutical SciencesMonash UniversityMelbourneVictoriaAustralia
| | - Saori Mukaida
- Drug Discovery Biology, Monash Institute of Pharmaceutical SciencesMonash UniversityMelbourneVictoriaAustralia
| | - Tore Bengtsson
- Department of Molecular Biosciences, The Wenner‐Gren InstituteStockholm UniversityStockholmSweden
| | - Dana S. Hutchinson
- Drug Discovery Biology, Monash Institute of Pharmaceutical SciencesMonash UniversityMelbourneVictoriaAustralia
| | - Masaaki Sato
- Drug Discovery Biology, Monash Institute of Pharmaceutical SciencesMonash UniversityMelbourneVictoriaAustralia
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12
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Evans BA, Merlin J, Bengtsson T, Hutchinson DS. Adrenoceptors in white, brown, and brite adipocytes. Br J Pharmacol 2019; 176:2416-2432. [PMID: 30801689 DOI: 10.1111/bph.14631] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2018] [Revised: 01/28/2019] [Accepted: 02/11/2019] [Indexed: 01/01/2023] Open
Abstract
Adrenoceptors play an important role in adipose tissue biology and physiology that includes regulating the synthesis and storage of triglycerides (lipogenesis), the breakdown of stored triglycerides (lipolysis), thermogenesis (heat production), glucose metabolism, and the secretion of adipocyte-derived hormones that can control whole-body energy homeostasis. These processes are regulated by the sympathetic nervous system through actions at different adrenoceptor subtypes expressed in adipose tissue depots. In this review, we have highlighted the role of adrenoceptor subtypes in white, brown, and brite adipocytes in both rodents and humans and have included detailed analysis of adrenoceptor expression in human adipose tissue and clonally derived adipocytes. We discuss important considerations when investigating adrenoceptor function in adipose tissue or adipocytes. LINKED ARTICLES: This article is part of a themed section on Adrenoceptors-New Roles for Old Players. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v176.14/issuetoc.
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Affiliation(s)
- Bronwyn A Evans
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, Australia
| | - Jon Merlin
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, Australia
| | - Tore Bengtsson
- Department of Molecular Biosciences, The Wenner-Gren Institute, The Arrhenius Laboratories F3, Stockholm University, Stockholm, Sweden
| | - Dana S Hutchinson
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, Australia
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13
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Takagi M, Kimura K, Nakashima KI, Hirai T, Inoue M. Induction of beige adipocytes by naturally occurring β3-adrenoceptor agonist p-synephrine. Eur J Pharmacol 2018; 836:67-74. [DOI: 10.1016/j.ejphar.2018.08.011] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2018] [Revised: 08/08/2018] [Accepted: 08/10/2018] [Indexed: 12/31/2022]
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14
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Effects of Polyphenols on Thermogenesis and Mitochondrial Biogenesis. Int J Mol Sci 2018; 19:ijms19092757. [PMID: 30217101 PMCID: PMC6164046 DOI: 10.3390/ijms19092757] [Citation(s) in RCA: 69] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2018] [Revised: 08/31/2018] [Accepted: 09/03/2018] [Indexed: 02/05/2023] Open
Abstract
Obesity is a health problem worldwide, and energy imbalance has been pointed out as one of the main factors responsible for its development. As mitochondria are a key element in energy homeostasis, the development of obesity has been strongly associated with mitochondrial imbalance. Polyphenols are the largest group of phytochemicals, widely distributed in the plant kingdom, abundant in fruits and vegetables, and have been classically described as antioxidants owing to their well-established ability to eliminate free radicals and reactive oxygen species (ROS). During the last decade, however, growing evidence reports the ability of polyphenols to perform several important biological activities in addition to their antioxidant activity. Special attention has been given to the ability of polyphenols to modulate mitochondrial processes. Thus, some polyphenols are now recognized as molecules capable of modulating pathways that regulate mitochondrial biogenesis, ATP synthesis, and thermogenesis, among others. The present review reports the main benefits of polyphenols in modulating mitochondrial processes that favor the regulation of energy expenditure and offer benefits in the management of obesity, especially thermogenesis and mitochondrial biogenesis.
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15
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Merlin J, Sato M, Nowell C, Pakzad M, Fahey R, Gao J, Dehvari N, Summers RJ, Bengtsson T, Evans BA, Hutchinson DS. The PPARγ agonist rosiglitazone promotes the induction of brite adipocytes, increasing β-adrenoceptor-mediated mitochondrial function and glucose uptake. Cell Signal 2017; 42:54-66. [PMID: 28970184 DOI: 10.1016/j.cellsig.2017.09.023] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2017] [Revised: 09/25/2017] [Accepted: 09/26/2017] [Indexed: 12/17/2022]
Abstract
Recruitment and activation of brite (or beige) adipocytes has been advocated as a potential avenue for manipulating whole-body energy expenditure. Despite numerous studies illustrating the differences in gene and protein markers between brown, brite and white adipocytes, there is very little information on the adrenergic regulation and function of these brite adipocytes. We have compared the functional (cyclic AMP accumulation, oxygen consumption rates, mitochondrial function, glucose uptake, extracellular acidification rates, calcium influx) profiles of mouse adipocytes cultured from three contrasting depots, namely interscapular brown adipose tissue, and inguinal or epididymal white adipose tissues, following chronic treatment with the peroxisome proliferator-activated receptor γ (PPARγ) agonist rosiglitazone. Prototypical brown adipocytes readily express β3-adrenoceptors, and β3-adrenoceptor stimulation increases cyclic AMP accumulation, oxygen consumption rates, mitochondrial function, glucose uptake, and extracellular acidification rates. Treatment of brown adipocytes with rosiglitazone increases uncoupling protein 1 (UCP1) levels, and increases β3-adrenoceptor mitochondrial function but does not affect glucose uptake responses. In contrast, inguinal white adipocytes only express UCP1 and β3-adrenoceptors following rosiglitazone treatment, which results in an increase in all β3-adrenoceptor-mediated functions. The effect of rosiglitazone in epididymal white adipocytes, was much lower compared to inguinal white adipocytes. Rosiglitazone also increased α1-adrenoceptor mediated increases in calcium influx and glucose uptake (but not mitochondrial function) in inguinal and epididymal white adipocytes. In conclusion, the PPARγ agonist rosiglitazone promotes the induction and function of brite adipocytes cultured from inguinal and epididymal white adipose depots.
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Affiliation(s)
- Jon Merlin
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, 381 Royal Parade, Monash University, Parkville, Victoria 3052, Australia
| | - Masaaki Sato
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, 381 Royal Parade, Monash University, Parkville, Victoria 3052, Australia
| | - Cameron Nowell
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, 381 Royal Parade, Monash University, Parkville, Victoria 3052, Australia
| | - Mohsen Pakzad
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, 381 Royal Parade, Monash University, Parkville, Victoria 3052, Australia; Department of Toxicology and Pharmacology, Faculty of Pharmacy and Pharmaceutical Sciences Research Center, Tehran University of Medical Sciences, Tehran 1417614411, Iran
| | - Richard Fahey
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, 381 Royal Parade, Monash University, Parkville, Victoria 3052, Australia
| | - Jie Gao
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, 381 Royal Parade, Monash University, Parkville, Victoria 3052, Australia
| | - Nodi Dehvari
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
| | - Roger J Summers
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, 381 Royal Parade, Monash University, Parkville, Victoria 3052, Australia; Department of Pharmacology, 9 Ancora Imparo Way, Monash University, Clayton, Victoria 3800, Australia
| | - Tore Bengtsson
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
| | - Bronwyn A Evans
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, 381 Royal Parade, Monash University, Parkville, Victoria 3052, Australia
| | - Dana S Hutchinson
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, 381 Royal Parade, Monash University, Parkville, Victoria 3052, Australia; Department of Pharmacology, 9 Ancora Imparo Way, Monash University, Clayton, Victoria 3800, Australia.
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16
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Douris N, Desai BN, Fisher FM, Cisu T, Fowler AJ, Zarebidaki E, Nguyen NLT, Morgan DA, Bartness TJ, Rahmouni K, Flier JS, Maratos-Flier E. Beta-adrenergic receptors are critical for weight loss but not for other metabolic adaptations to the consumption of a ketogenic diet in male mice. Mol Metab 2017; 6:854-862. [PMID: 28752049 PMCID: PMC5518722 DOI: 10.1016/j.molmet.2017.05.017] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/28/2017] [Revised: 05/26/2017] [Accepted: 05/31/2017] [Indexed: 11/21/2022] Open
Abstract
OBJECTIVE We have previously shown that the consumption of a low-carbohydrate ketogenic diet (KD) by mice leads to a distinct physiologic state associated with weight loss, increased metabolic rate, and improved insulin sensitivity [1]. Furthermore, we identified fibroblast growth factor 21 (FGF21) as a necessary mediator of the changes, as mice lacking FGF21 fed KD gain rather than lose weight [2]. FGF21 activates the sympathetic nervous system (SNS) [3], which is a key regulator of metabolic rate. Thus, we considered that the SNS may play a role in mediating the metabolic adaption to ketosis. METHODS To test this hypothesis, we measured the response of mice lacking all three β-adrenergic receptors (β-less mice) to KD feeding. RESULTS In contrast to wild-type (WT) controls, β-less mice gained weight, increased adipose tissue depots mass, and did not increase energy expenditure when consuming KD. Remarkably, despite weight-gain, β-less mice were insulin sensitive. KD-induced changes in hepatic gene expression of β-less mice were similar to those seen in WT controls eating KD. Expression of FGF21 mRNA rose over 60-fold in both WT and β-less mice fed KD, and corresponding circulating FGF21 levels were 12.5 ng/ml in KD-fed wild type controls and 35.5 ng/ml in KD-fed β-less mice. CONCLUSIONS The response of β-less mice distinguishes at least two distinct categories of physiologic effects in mice consuming KD. In the liver, KD regulates peroxisome proliferator-activated receptor alpha (PPARα)-dependent pathways through an action of FGF21 independent of the SNS and beta-adrenergic receptors. In sharp contrast, induction of interscapular brown adipose tissue (BAT) and increased energy expenditure absolutely require SNS signals involving action on one or more β-adrenergic receptors. In this way, the key metabolic actions of FGF21 in response to KD have diverse effector mechanisms.
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Key Words
- BAT, brown adipose tissue
- EE, energy expenditure
- FGF21, fibroblast growth factor 21
- IP, intraperitoneal
- ITT, insulin tolerance test
- IWAT, inguinal white adipose tissue
- KD, ketogenic diet
- Ketogenic diet
- PPARα, peroxisome proliferator-activated receptor alpha
- SEM, standard error of the mean
- SNA, sympathetic nerve activity
- SNS, sympathetic nervous system
- Sympathetic nervous system
- UCP1, uncoupling protein 1
- Weight loss
- β-Adrenergic receptors
- β-less, lacking β1, β2, β3 adrenergic receptors
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Affiliation(s)
- Nicholas Douris
- Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA
| | - Bhavna N Desai
- Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA
| | - Ffolliott M Fisher
- Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA
| | - Theodore Cisu
- Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA
| | - Alan J Fowler
- Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA
| | - Eleen Zarebidaki
- Department of Biology and Center for Obesity Reversal, Georgia State University, Atlanta, GA 30302-4010, USA
| | - Ngoc Ly T Nguyen
- Department of Biology and Center for Obesity Reversal, Georgia State University, Atlanta, GA 30302-4010, USA
| | - Donald A Morgan
- Department of Pharmacology, University of Iowa, Carver College of Medicine, Iowa City, IA 52242, USA
| | - Timothy J Bartness
- Department of Biology and Center for Obesity Reversal, Georgia State University, Atlanta, GA 30302-4010, USA
| | - Kamal Rahmouni
- Department of Pharmacology, University of Iowa, Carver College of Medicine, Iowa City, IA 52242, USA
| | - Jeffrey S Flier
- Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA
| | - Eleftheria Maratos-Flier
- Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA.
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17
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de Jong JMA, Wouters RTF, Boulet N, Cannon B, Nedergaard J, Petrovic N. The β 3-adrenergic receptor is dispensable for browning of adipose tissues. Am J Physiol Endocrinol Metab 2017; 312:E508-E518. [PMID: 28223294 DOI: 10.1152/ajpendo.00437.2016] [Citation(s) in RCA: 56] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/06/2016] [Revised: 02/06/2017] [Accepted: 02/16/2017] [Indexed: 12/30/2022]
Abstract
Brown and brite/beige adipocytes are attractive therapeutic targets to treat metabolic diseases. To maximally utilize their functional potential, further understanding is required about their identities and their functional differences. Recent studies with β3-adrenergic receptor knockout mice reported that brite/beige adipocytes, but not classical brown adipocytes, require the β3-adrenergic receptor for cold-induced transcriptional activation of thermogenic genes. We aimed to further characterize this requirement of the β3-adrenergic receptor as a functional distinction between classical brown and brite/beige adipocytes. However, when comparing wild-type and β3-adrenergic receptor knockout mice, we observed no differences in cold-induced thermogenic gene expression (Ucp1, Pgc1a, Dio2, and Cidea) in brown or white (brite/beige) adipose tissues. Irrespective of the duration of the cold exposure or the sex of the mice, we observed no effect of the absence of the β3-adrenergic receptor. Experiments with the β3-adrenergic receptor agonist CL-316,243 verified the functional absence of β3-adrenergic signaling in these knockout mice. The β3-adrenergic receptor knockout model in the present study was maintained on a FVB/N background, whereas earlier reports used C57BL/6 and 129Sv mice. Thus our data imply background-dependent differences in adrenergic signaling mechanisms in response to cold exposure. Nonetheless, the present data indicate that the β3-adrenergic receptor is dispensable for cold-induced transcriptional activation in both classical brown and, as opposed to earlier studies, brite/beige cells.
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MESH Headings
- Adipogenesis/drug effects
- Adipose Tissue, Beige/cytology
- Adipose Tissue, Beige/drug effects
- Adipose Tissue, Beige/metabolism
- Adipose Tissue, Brown/cytology
- Adipose Tissue, Brown/drug effects
- Adipose Tissue, Brown/metabolism
- Adrenergic beta-3 Receptor Agonists/pharmacology
- Animals
- Cold-Shock Response/drug effects
- Dioxoles/pharmacology
- Female
- Gene Expression Regulation/drug effects
- Intra-Abdominal Fat/cytology
- Intra-Abdominal Fat/drug effects
- Intra-Abdominal Fat/metabolism
- Male
- Mice
- Mice, Knockout
- RNA, Messenger/metabolism
- Receptors, Adrenergic, beta-1/genetics
- Receptors, Adrenergic, beta-1/metabolism
- Receptors, Adrenergic, beta-3/chemistry
- Receptors, Adrenergic, beta-3/genetics
- Receptors, Adrenergic, beta-3/metabolism
- Reproducibility of Results
- Signal Transduction/drug effects
- Species Specificity
- Time Factors
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Affiliation(s)
- Jasper M A de Jong
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
| | - René T F Wouters
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
| | - Nathalie Boulet
- 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
| | - Jan Nedergaard
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
| | - Natasa Petrovic
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
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18
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Mukaida S, Evans BA, Bengtsson T, Hutchinson DS, Sato M. Adrenoceptors promote glucose uptake into adipocytes and muscle by an insulin-independent signaling pathway involving mechanistic target of rapamycin complex 2. Pharmacol Res 2016; 116:87-92. [PMID: 28025104 DOI: 10.1016/j.phrs.2016.12.022] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/01/2016] [Revised: 11/12/2016] [Accepted: 12/13/2016] [Indexed: 12/15/2022]
Abstract
Uptake of glucose into skeletal muscle and adipose tissue plays a vital role in metabolism and energy balance. Insulin released from β-islet cells of the pancreas promotes glucose uptake in these target tissues by stimulating translocation of GLUT4 transporters to the cell surface. This process is complex, involving signaling proteins including the mechanistic (or mammalian) target of rapamycin (mTOR) and Akt that intersect with multiple pathways controlling cell survival, growth and proliferation. mTOR exists in two forms, mTOR complex 1 (mTORC1), and mTOR complex 2 (mTORC2). mTORC1 has been intensively studied, acting as a key regulator of protein and lipid synthesis that integrates cellular nutrient availability and energy balance. Studies on mTORC2 have focused largely on its capacity to activate Akt by phosphorylation at Ser473, however recent findings demonstrate a novel role for mTORC2 in cellular glucose uptake. For example, agonists acting at β2-adrenoceptors (ARs) in skeletal muscle or β3-ARs in brown adipose tissue increase glucose uptake in vitro and in vivo via mechanisms dependent on mTORC2 but not Akt. In this review, we will focus on the signaling pathways downstream of β-ARs that promote glucose uptake in skeletal muscle and brown adipocytes, and will highlight how the insulin and adrenergic pathways converge and interact in these cells. The identification of insulin-independent mechanisms that promote glucose uptake should facilitate novel treatment strategies for metabolic disease.
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Affiliation(s)
- Saori Mukaida
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, Victoria 3052, Australia
| | - Bronwyn A Evans
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, Victoria 3052, Australia
| | - Tore Bengtsson
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, SE-10691 Stockholm, Sweden
| | - Dana S Hutchinson
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, Victoria 3052, Australia
| | - Masaaki Sato
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, Victoria 3052, Australia.
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19
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Abstract
The demonstration of the presence of metabolically active brown adipose tissue (BAT) in adult humans using positron emission tomography (PET) over the past decade has lead to the rapid development of our knowledge regarding the role of BAT in energy metabolism in animal models and in humans. Although animal models continue to provide highly valuable information regarding the mechanisms regulating BAT development, mass and metabolic functions, these studies led to many assumptions that have been at best only partially verified in humans so far. Combined to some limitations of the current investigation approaches used in humans, this has lead to speculation on the potential role of BAT dysfunction in the development of cardiometabolic disorders and on the potential of BAT metabolic activation to treat these conditions. Here we propose a critical review of the evidence for the implication of BAT in cardiometabolic health.
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Affiliation(s)
- Denis P Blondin
- Department of Medicine, Centre de Recherche du Centre Hospitalier Universitaire de Sherbrooke, Université de Sherbrooke, Sherbrooke, Canada
| | - André C Carpentier
- Department of Medicine, Centre de Recherche du Centre Hospitalier Universitaire de Sherbrooke, Université de Sherbrooke, Sherbrooke, Canada.
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20
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Hibi M, Oishi S, Matsushita M, Yoneshiro T, Yamaguchi T, Usui C, Yasunaga K, Katsuragi Y, Kubota K, Tanaka S, Saito M. Brown adipose tissue is involved in diet-induced thermogenesis and whole-body fat utilization in healthy humans. Int J Obes (Lond) 2016; 40:1655-1661. [PMID: 27430878 PMCID: PMC5116053 DOI: 10.1038/ijo.2016.124] [Citation(s) in RCA: 83] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/12/2016] [Revised: 06/06/2016] [Accepted: 06/23/2016] [Indexed: 12/17/2022]
Abstract
Background/Objectives: Brown adipose tissue (BAT) is a potential therapeutic target against obesity and diabetes through thermogenesis and substrate disposal with cold exposure. The role of BAT in energy metabolism under thermoneutral conditions, however, remains controversial. We assessed the contribution of BAT to energy expenditure (EE), particularly diet-induced thermogenesis (DIT), and substrate utilization in human adults. Methods: In this cross-sectional study, BAT activity was evaluated in 21 men using 18F-fluoro-2-deoxy-D-glucose positron emission tomography combined with computed tomography (18F-FDG-PET/CT) after cold exposure (19 °C). The subjects were divided into BAT-positive (n=13) and BAT-negative (n=8) groups according to the 18F-FDG-PET/CT findings. Twenty-four hour EE, DIT and respiratory quotient were measured using a whole-room indirect calorimeter at 27 °C. Results: Body composition, blood metabolites and 24-h EE did not differ between groups. DIT (%), calculated as DIT divided by total energy intake, however, was significantly higher in the BAT-positive group (BAT-positive: 9.7±2.5%, BAT-negative: 6.5±4.0%, P=0.03). The 24-h respiratory quotient was significantly lower (P=0.03) in the BAT-positive group (0.861±0.027) than in the BAT-negative group (0.889±0.024). Conclusion: DIT and fat utilization were higher in BAT-positive subjects compared to BAT-negative subjects, suggesting that BAT has a physiologic role in energy metabolism.
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Affiliation(s)
- M Hibi
- Health Care Food Research Laboratories, Kao Corporation, Tokyo, Japan
| | - S Oishi
- Health Care Food Research Laboratories, Kao Corporation, Tokyo, Japan
| | - M Matsushita
- Department of Nutrition, Tenshi College, Sapporo, Japan
| | - T Yoneshiro
- Department of Biomedical Sciences, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo, Japan
| | - T Yamaguchi
- Health Care Food Research Laboratories, Kao Corporation, Tokyo, Japan
| | - C Usui
- Department of Nutritional Science, National Institute of Health and Nutrition, National Institutes of Biomedical Innovation, Health and Nutrition, Tokyo, Japan
| | - K Yasunaga
- Health Care Food Research Laboratories, Kao Corporation, Tokyo, Japan
| | - Y Katsuragi
- Health Care Food Research Laboratories, Kao Corporation, Tokyo, Japan
| | - K Kubota
- Division of Nuclear Medicine, Department of Radiology, National Center for Global Health and Medicine, Tokyo, Japan
| | - S Tanaka
- Department of Nutritional Science, National Institute of Health and Nutrition, National Institutes of Biomedical Innovation, Health and Nutrition, Tokyo, Japan
| | - M Saito
- Department of Nutrition, Tenshi College, Sapporo, Japan
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Walton RG, Zhu X, Tian L, Heywood EB, Liu J, Hill HS, Liu J, Bruemmer D, Yang Q, Fu Y, Garvey WT. AP2-NR4A3 transgenic mice display reduced serum epinephrine because of increased catecholamine catabolism in adipose tissue. Am J Physiol Endocrinol Metab 2016; 311:E69-81. [PMID: 27166283 PMCID: PMC4967153 DOI: 10.1152/ajpendo.00330.2015] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/15/2015] [Accepted: 05/03/2016] [Indexed: 01/25/2023]
Abstract
The NR4A orphan nuclear receptors function as early response genes to numerous stimuli. Our laboratory has previously demonstrated that overexpression of NR4A3 (NOR-1, MINOR) in 3T3-L1 adipocytes enhances insulin-stimulated glucose uptake. To assess the in vivo effect of NR4A3 on adipocytes, we generated transgenic mice with NR4A3 overexpression driven by the adipocyte fatty acid-binding protein (AP2) promoter (AP2-NR4A3 mice). We hypothesized that AP2-NR4A3 mice would display enhanced glucose tolerance and insulin sensitivity. However, AP2-NR4A3 mice exhibit metabolic impairment, including increased fasting glucose and insulin, impaired glucose tolerance, insulin resistance, decreased serum free fatty acids, and increased low-density lipoprotein-cholesterol. AP2-NR4A3 mice also display a significant reduction in serum epinephrine due to increased expression of catecholamine-catabolizing enzymes in adipose tissue, including monoamine oxidase-A. Furthermore, enhanced expression of monoamine oxidase-A is due to direct transcriptional activation by NR4A3. Finally, AP2-NR4A3 mice display cardiac and behavioral alterations consistent with chronically low circulating epinephrine levels. In conclusion, overexpression of NR4A3 in adipocytes produces a complex phenotype characterized by impaired glucose metabolism and low serum catecholamines due to enhanced degradation by adipose tissue.
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Affiliation(s)
- R Grace Walton
- Department of Nutrition Sciences, University of Alabama at Birmingham, Birmingham, Alabama;
| | - Xiaolin Zhu
- Department of Nutrition Sciences, University of Alabama at Birmingham, Birmingham, Alabama
| | - Ling Tian
- Department of Nutrition Sciences, University of Alabama at Birmingham, Birmingham, Alabama
| | - Elizabeth B Heywood
- Saha Cardiovascular Research Center and Graduate Center for Nutritional Sciences, University of Kentucky, Lexington, Kentucky
| | - Jian Liu
- Department of Nutrition Sciences, University of Alabama at Birmingham, Birmingham, Alabama
| | - Helliner S Hill
- Department of Nutrition Sciences, University of Alabama at Birmingham, Birmingham, Alabama
| | - Jiarong Liu
- Division of Molecular and Cellular Pathology, Department of Pathology, University of Alabama at Birmingham, Birmingham, Alabama; and
| | - Dennis Bruemmer
- Saha Cardiovascular Research Center and Graduate Center for Nutritional Sciences, University of Kentucky, Lexington, Kentucky
| | - Qinglin Yang
- Department of Nutrition Sciences, University of Alabama at Birmingham, Birmingham, Alabama
| | - Yuchang Fu
- Department of Nutrition Sciences, University of Alabama at Birmingham, Birmingham, Alabama
| | - W Timothy Garvey
- Department of Nutrition Sciences, University of Alabama at Birmingham, Birmingham, Alabama; Birmingham Veterans Affairs Medical Center, Birmingham, Alabama
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22
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Propping S, Lorenz K, Michel MC, Wirth MP, Ravens U. β-Adrenoceptor-mediated Relaxation of Urinary Bladder Muscle in β2-Adrenoceptor Knockout Mice. Front Pharmacol 2016; 7:118. [PMID: 27242525 PMCID: PMC4860462 DOI: 10.3389/fphar.2016.00118] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2016] [Accepted: 04/22/2016] [Indexed: 11/13/2022] Open
Abstract
Background and Objective: In order to characterize the β-adrenoceptor (AR) subtypes involved in agonist-stimulated relaxation of murine urinary bladder we studied the effects of (-)-isoprenaline and CL 316,243 on tonic contraction and spontaneous contractions in detrusor strips of wild-type (WT) and β2-AR knockout (β2-AR KO) mice. Materials and Methods: Urinary bladders were isolated from male WT and β2-AR KO mice. β-AR subtype expression was determined with quantitative real-time PCR. Intact muscle strips pre-contracted with KCl (40 mM) were exposed to cumulatively increasing concentrations of (-)-isoprenaline or β3-AR agonist CL 316,243 in the presence and absence of the subtype-selective β-AR blockers CGP 20712A (β1-ARs), ICI 118,551 (β2-ARs), and L748,337 (β3-ARs). Results: Quantitative real-time PCR confirmed lack of β2-AR expression in bladder tissue from β2-AR KO mice. In isolated detrusor strips, pre-contraction with KCl increased basal tone and enhanced spontaneous activity significantly more in β2-AR KO than in WT. (-)-Isoprenaline relaxed tonic tension and attenuated spontaneous activity with similar potency, but the concentrations required were two orders of magnitude higher in β2-AR KO than WT. The concentration-response curves (CRCs) for relaxation were not affected by CGP 20712A (300 nM), but were shifted to the right by ICI 118,551 (50 nM) and L748,337 (10 μM). The -logEC50 values for (-)-isoprenaline in WT and β2-AR KO tissue were 7.98 and 6.00, respectively, suggesting a large receptor reserve of β2-AR. (-)-CL 316,243 relaxed detrusor and attenuated spontaneous contractions from WT and β2-AR KO mice with a potency corresponding to the drug’s affinity for β3-AR. L743,337 shifted the CRCs to the right. Conclusion: Our findings in β2-AR KO mice suggest that there is a large receptor reserve for β2-AR in WT mice so that this β-AR subtype will mediate relaxation of tone and attenuation of spontaneous activity under physiological conditions. Nevertheless, upon removal of this reserve, β3-AR can also mediate murine detrusor relaxation.
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Affiliation(s)
- Stefan Propping
- Department of Urology, Faculty of Medicine Carl Gustav Carus, Dresden University of TechnologyDresden, Germany; Department of Physiology, Faculty of Medicine Carl Gustav Carus, Dresden University of TechnologyDresden, Germany
| | - Kristina Lorenz
- Department of Pharmacology and Toxicology, Julius Maximilian University WürzburgWürzburg, Germany; Leibniz-Institute für Analytische Wissenschaften-ISAS-e.V.Dortmund, Germany; West German Heart and Vascular Center Essen, University Hospital Essen-DuisburgDuisburg, Germany
| | - Martin C Michel
- Department of Pharmacology, Johannes Gutenberg University Mainz, Germany
| | - Manfred P Wirth
- Department of Urology, Faculty of Medicine Carl Gustav Carus, Dresden University of Technology Dresden, Germany
| | - Ursula Ravens
- Department of Physiology, Faculty of Medicine Carl Gustav Carus, Dresden University of Technology Dresden, Germany
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23
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Merlin J, Evans BA, Dehvari N, Sato M, Bengtsson T, Hutchinson DS. Could burning fat start with a brite spark? Pharmacological and nutritional ways to promote thermogenesis. Mol Nutr Food Res 2015. [DOI: 10.1002/mnfr.201500251] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Jon Merlin
- Drug Discovery Biology; Monash Institute of Pharmaceutical Sciences; Monash University; Parkville Australia
| | - Bronwyn A. Evans
- Drug Discovery Biology; Monash Institute of Pharmaceutical Sciences; Monash University; Parkville Australia
| | - Nodi Dehvari
- Department of Molecular Biosciences; The Wenner-Gren Institute; Stockholm University; Stockholm Sweden
| | - Masaaki Sato
- Drug Discovery Biology; Monash Institute of Pharmaceutical Sciences; Monash University; Parkville Australia
- Department of Pharmacology; Monash University; Clayton Australia
| | - Tore Bengtsson
- Department of Molecular Biosciences; The Wenner-Gren Institute; Stockholm University; Stockholm Sweden
| | - Dana S. Hutchinson
- Drug Discovery Biology; Monash Institute of Pharmaceutical Sciences; Monash University; Parkville Australia
- Department of Pharmacology; Monash University; Clayton Australia
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24
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Olsen JM, Sato M, Dallner OS, Sandström AL, Pisani DF, Chambard JC, Amri EZ, Hutchinson DS, Bengtsson T. Glucose uptake in brown fat cells is dependent on mTOR complex 2-promoted GLUT1 translocation. ACTA ACUST UNITED AC 2015; 207:365-74. [PMID: 25385184 PMCID: PMC4226734 DOI: 10.1083/jcb.201403080] [Citation(s) in RCA: 126] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Brown adipose tissue is the primary site for thermogenesis and can consume, in addition to free fatty acids, a very high amount of glucose from the blood, which can both acutely and chronically affect glucose homeostasis. Here, we show that mechanistic target of rapamycin (mTOR) complex 2 has a novel role in β3-adrenoceptor-stimulated glucose uptake in brown adipose tissue. We show that β3-adrenoceptors stimulate glucose uptake in brown adipose tissue via a signaling pathway that is comprised of two different parts: one part dependent on cAMP-mediated increases in GLUT1 transcription and de novo synthesis of GLUT1 and another part dependent on mTOR complex 2-stimulated translocation of newly synthesized GLUT1 to the plasma membrane, leading to increased glucose uptake. Both parts are essential for β3-adrenoceptor-stimulated glucose uptake. Importantly, the effect of β3-adrenoceptor on mTOR complex 2 is independent of the classical insulin-phosphoinositide 3-kinase-Akt pathway, highlighting a novel mechanism of mTOR complex 2 activation.
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Affiliation(s)
- Jessica M Olsen
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, SE -0691 Stockholm, Sweden
| | - Masaaki Sato
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, SE -0691 Stockholm, Sweden Department of Pharmacology and Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Parkville, Victoria 3052, Australia Department of Pharmacology and Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Parkville, Victoria 3052, Australia
| | - Olof S Dallner
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, SE -0691 Stockholm, Sweden Laboratory of Molecular Genetics, Howard Hughes Medical Institute, The Rockefeller University, New York, NY 10065
| | - Anna L Sandström
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, SE -0691 Stockholm, Sweden
| | - Didier F Pisani
- Institute of Biology Valrose, Centre National de la Recherche Scientifique UMR 7277, Institut National de la Santé et de la Recherche Médicale UMR 1091, University of Nice Sophia Antipolis, 06100 Nice, France
| | - Jean-Claude Chambard
- Institute of Biology Valrose, Centre National de la Recherche Scientifique UMR 7277, Institut National de la Santé et de la Recherche Médicale UMR 1091, University of Nice Sophia Antipolis, 06100 Nice, France
| | - Ez-Zoubir Amri
- Institute of Biology Valrose, Centre National de la Recherche Scientifique UMR 7277, Institut National de la Santé et de la Recherche Médicale UMR 1091, University of Nice Sophia Antipolis, 06100 Nice, France
| | - Dana S Hutchinson
- Department of Pharmacology and Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Parkville, Victoria 3052, Australia Department of Pharmacology and Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Parkville, Victoria 3052, Australia
| | - Tore Bengtsson
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, SE -0691 Stockholm, Sweden
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25
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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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26
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Nishida M, Kozakai T, Nagami K, Kanamaru Y, Yabe T. Structural alteration of cell surface heparan sulfate through the stimulation of the signaling pathway for heparan sulfate 6-O-sulfotransferase-1 in mouse fibroblast cells. Biosci Biotechnol Biochem 2014; 78:770-9. [PMID: 25035978 DOI: 10.1080/09168451.2014.905178] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Heparan sulfate (HS) is a randomly sulfated polysaccharide that is present on the cell surface and in the extracellular matrix. The sulfated structures of HS were synthesized by multiple HS sulfotransferases, thereby regulating various activities such as growth factor signaling, cell differentiation, and tumor metastasis. Therefore, if the sulfated structures of HS could be artificially controlled, those manipulations would help to understand the various functions depending on HS. However, little knowledge is currently available to realize the mechanisms controlling the expression of such enzymes. In this study, we found that the ratio of 6-O-sulfated disaccharides increased at 3 h after adrenaline stimulation in mouse fibroblast cells. Furthermore, adrenaline-induced up-regulation of HS 6-O-sulfotransferase-1 (6-OST-1) was controlled by Src-ERK1/2 signaling pathway. Finally, inhibiting the signaling pathways for 6-OST-1 intentionally suppressed the adrenaline-induced structural alteration of HS. These observations provide fundamental insights into the understanding of structural alterations in HS by extracellular cues.
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Affiliation(s)
- Mitsutaka Nishida
- a United Graduate School of Agricultural Science, Gifu University , Gifu , Japan
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27
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Functional annotation of genes differentially expressed between primary motor and prefrontal association cortices of macaque brain. Neurochem Res 2012; 38:133-40. [PMID: 23054074 DOI: 10.1007/s11064-012-0900-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2012] [Revised: 09/13/2012] [Accepted: 10/03/2012] [Indexed: 10/27/2022]
Abstract
DNA microarray-based genome-wide transcriptional profiling and gene network analyses were used to characterize the molecular underpinnings of the neocortical organization in rhesus macaque, with particular focus on the differences in the functional annotation of genes in the primary motor cortex (M1) and the prefrontal association cortex (area 46 of Brodmann). Functional annotation of the differentially expressed genes showed that the list of genes selectively expressed in M1 was enriched with genes involved in oligodendrocyte function, and energy consumption. The annotation appears to have successfully extracted the characteristics of the molecular structure of M1.
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28
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Effects of norepinephrine and acetylcholine on the development of cultured Leydig cells in mice. J Biomed Biotechnol 2012; 2012:503093. [PMID: 23093848 PMCID: PMC3470896 DOI: 10.1155/2012/503093] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2012] [Revised: 05/27/2012] [Accepted: 06/18/2012] [Indexed: 11/18/2022] Open
Abstract
Few data have suggested how norepinephrine (NE) and acetylcholine (Ach) regulate the development of Leydig cells in mice at prepuberty, except for data indicating endocrine effects. The present study aims to elucidate the roles of NE and Ach on the differentiation and proliferation of Leydig cells. Firstly, the expression of adrenergic receptors and muscarinic acetylcholine receptors in Leydig cells was investigated. It was found that adrenergic receptors (β1AR, β2AR, and α1D) and muscarinic acetylcholine receptors (M1 and M3) mRNA are expressed in adult Leydig cells. Then, the effects of NE and Ach on the differentiation and proliferation of Leydig cells were analyzed. The results showed that NE and Ach at 10 μM significantly increased the number of 3β-hydroxysteroid-dehydrogenase- (3β-HSD-) positive Leydig cells and improved the expression of proliferating cell nuclear antigen (PCNA) in Leydig cells on postnatal day (PD) 15 (P < 0.05). NE and Ach at 10 μM had no impact on the expression of PCNA mRNA (P > 0.05), but reduced the expression of 3β-HSD mRNA in adult Leydig cells and a murine Leydig tumor cell line (MLTC-1) (P < 0.05). Therefore, a conclusion may be reached that NE and Ach participated in stimulating the development of Leydig cells in mice from prepuberty to adult stage.
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29
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de Queiroz KB, Rodovalho GV, Guimarães JB, de Lima DC, Coimbra CC, Evangelista EA, Guerra-Sá R. Endurance training blocks uncoupling protein 1 up-regulation in brown adipose tissue while increasing uncoupling protein 3 in the muscle tissue of rats fed with a high-sugar diet. Nutr Res 2012; 32:709-17. [PMID: 23084644 DOI: 10.1016/j.nutres.2012.06.020] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2012] [Revised: 06/16/2012] [Accepted: 06/29/2012] [Indexed: 10/27/2022]
Abstract
The mitochondrial uncoupling proteins (UCPs) of interscapular brown adipose tissue (iBAT) and of muscles play important roles in energy balance. For instance, the expression of UCP1 and UCP3 are modulated by free fatty acid gradients induced by high-sugar diets and acute exercise that is dependent on sympathetic stimulation. However, the effects of endurance training in animals fed with high-sugar diets are unknown. This study aims to evaluate the long-term effects of diet and exercise on UCP1 and UCP3 levels and energy balance efficiency. Rats fed with standard or high-sugar (HSD) diets were simultaneously subjected to running training over an 8-week period. After the training period, the rats were decapitated, and the iBAT and gastrocnemius muscle tissues were removed for evaluation of the β₃-receptor, Ucp1, and Ucp3 mRNA and protein expression, which were analyzed by quantitative reverse transcriptase polymerase chain reaction and Western blot, respectively. Groups fed with an HSD displayed a higher adiposity index and iBAT weight (P < .05), whereas exhibited an up-regulation of Ucp1 mRNA and protein levels (P < .05). Training increased β₃-receptor mRNA in iBAT and reduced the Ucp3 mRNA in muscle tissues. In association with an HSD, training restored the increasing β₃-receptor mRNA and greatly up-regulated the levels of Ucp3 mRNA. Therefore, training blocked the HSD-induced up-regulation of UCP1 expression in iBAT, whereas it up-regulated the expression of Ucp3 mRNA in muscle. These results suggest that training enhances the relationship between Ucp1/Ucp3 mRNA levels, which could result in higher energy efficiency, but not when HSD-induced elevated sympathetic activity is maintained.
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Affiliation(s)
- Karina Barbosa de Queiroz
- Departmento de Ciências Biológicas-NUPEB, Laboratório de Bioquímica e Biologia Molecular, ICEB-Universidade Federal de Ouro Preto, Ouro Preto, MG, Brazil
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30
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Dehvari N, Hutchinson DS, Nevzorova J, Dallner OS, Sato M, Kocan M, Merlin J, Evans BA, Summers RJ, Bengtsson T. β(2)-Adrenoceptors increase translocation of GLUT4 via GPCR kinase sites in the receptor C-terminal tail. Br J Pharmacol 2012; 165:1442-56. [PMID: 21883150 DOI: 10.1111/j.1476-5381.2011.01647.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
BACKGROUND AND PURPOSE β-Adrenoceptor stimulation induces glucose uptake in several insulin-sensitive tissues by poorly understood mechanisms. EXPERIMENTAL APPROACH We used a model system in CHO-K1 cells expressing the human β(2)-adrenoceptor and glucose transporter 4 (GLUT4) to investigate the signalling mechanisms involved. KEY RESULTS In CHO-K1 cells, there was no response to β-adrenoceptor agonists. The introduction of β(2)-adrenoceptors and GLUT4 into these cells caused increased glucose uptake in response to β-adrenoceptor agonists. GLUT4 translocation occurred in response to insulin and β(2)-adrenoceptor stimulation, although the key insulin signalling intermediate PKB was not phosphorylated in response to β(2)-adrenoceptor stimulation. Truncation of the C-terminus of the β(2)-adrenoceptor at position 349 to remove known phosphorylation sites for GPCR kinases (GRKs) or at position 344 to remove an additional PKA site together with the GRK phosphorylation sites did not significantly affect cAMP accumulation but decreased β(2)-adrenoceptor-stimulated glucose uptake. Furthermore, inhibition of GRK by transfection of the βARKct construct inhibited β(2)-adrenoceptor-mediated glucose uptake and GLUT4 translocation, and overexpression of a kinase-dead GRK2 mutant (GRK2 K220R) also inhibited GLUT4 translocation. Introducing β(2)-adrenoceptors lacking phosphorylation sites for GRK or PKA demonstrated that the GRK sites, but not the PKA sites, were necessary for GLUT4 translocation. CONCLUSIONS AND IMPLICATIONS Glucose uptake in response to activation of β(2)-adrenoceptors involves translocation of GLUT4 in this model system. The mechanism is dependent on the C-terminus of the β(2)-adrenoceptor, requires GRK phosphorylation sites, and involves a signalling pathway distinct from that stimulated by insulin.
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Affiliation(s)
- Nodi Dehvari
- Department of Physiology, The Wenner-Gren Institute, Arrhenius Laboratories F3, Stockholm University, Stockholm, Sweden
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31
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Sato M, Hutchinson DS, Halls ML, Furness SGB, Bengtsson T, Evans BA, Summers RJ. Interaction with caveolin-1 modulates G protein coupling of mouse β3-adrenoceptor. J Biol Chem 2012; 287:20674-88. [PMID: 22535965 DOI: 10.1074/jbc.m111.280651] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Caveolins act as scaffold proteins in multiprotein complexes and have been implicated in signaling by G protein-coupled receptors. Studies using knock-out mice suggest that β(3)-adrenoceptor (β(3)-AR) signaling is dependent on caveolin-1; however, it is not known whether caveolin-1 is associated with the β(3)-AR or solely with downstream signaling proteins. We have addressed this question by examining the impact of membrane rafts and caveolin-1 on the differential signaling of mouse β(3a)- and β(3b)-AR isoforms that diverge at the distal C terminus. Only the β(3b)-AR promotes pertussis toxin (PTX)-sensitive cAMP accumulation. When cells expressing the β(3a)-AR were treated with filipin III to disrupt membrane rafts or transfected with caveolin-1 siRNA, the cyclic AMP response to the β(3)-AR agonist CL316243 became PTX-sensitive, suggesting Gα(i/o) coupling. The β(3a)-AR C terminus, SP(384)PLNRF(389)DGY(392)EGARPF(398)PT, resembles a caveolin interaction motif. Mutant β(3a)-ARs (F389A/Y392A/F398A or P384S/F389A) promoted PTX-sensitive cAMP responses, and in situ proximity assays demonstrated an association between caveolin-1 and the wild type β(3a)-AR but not the mutant receptors. In membrane preparations, the β(3b)-AR activated Gα(o) and mediated PTX-sensitive cAMP responses, whereas the β(3a)-AR did not activate Gα(i/o) proteins. The endogenous β(3a)-AR displayed Gα(i/o) coupling in brown adipocytes from caveolin-1 knock-out mice or in wild type adipocytes treated with filipin III. Our studies indicate that interaction of the β(3a)-AR with caveolin inhibits coupling to Gα(i/o) proteins and suggest that signaling is modulated by a raft-enriched complex containing the β(3a)-AR, caveolin-1, Gα(s), and adenylyl cyclase.
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Affiliation(s)
- Masaaki Sato
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences and the Department of Pharmacology, Monash University, Parkville, Victoria 3052, Australia
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32
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Patel PR, Ramakrishnan SK, Kaw MK, Raphael CK, Ghosh S, Marino JS, Heinrich G, Lee SJ, Bourey RE, Hill JW, Jung DY, Morgan DA, Kim JK, Rahmouni SK, Najjar SM. Increased metabolic rate and insulin sensitivity in male mice lacking the carcino-embryonic antigen-related cell adhesion molecule 2. Diabetologia 2012; 55:763-72. [PMID: 22159884 PMCID: PMC3272352 DOI: 10.1007/s00125-011-2388-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/22/2011] [Accepted: 11/07/2011] [Indexed: 10/14/2022]
Abstract
AIMS/HYPOTHESIS The carcino-embryonic antigen-related cell adhesion molecule (CEACAM)2 is produced in many feeding control centres in the brain, but not in peripheral insulin-targeted tissues. Global Ceacam2 null mutation causes insulin resistance and obesity resulting from hyperphagia and hypometabolism in female Ceacam2 homozygous null mutant mice (Cc2 [also known as Ceacam2](-/-)) mice. Because male mice are not obese, the current study examined their metabolic phenotype. METHODS The phenotype of male Cc2(-/-) mice was characterised by body fat composition, indirect calorimetry, hyperinsulinaemic-euglycaemic clamp analysis and direct recording of sympathetic nerve activity. RESULTS Despite hyperphagia, total fat mass was reduced, owing to the hypermetabolic state in male Cc2(-/-) mice. In contrast to females, male mice also exhibited insulin sensitivity with elevated β-oxidation in skeletal muscle, which is likely to offset the effects of increased food intake. Males and females had increased brown adipogenesis. However, only males had increased activation of sympathetic tone regulation of adipose tissue and increased spontaneous activity. The mechanisms underlying sexual dimorphism in energy balance with the loss of Ceacam2 remain unknown. CONCLUSIONS/INTERPRETATION These studies identified a novel role for CEACAM2 in the regulation of metabolic rate and insulin sensitivity via effects on brown adipogenesis, sympathetic nervous outflow to brown adipose tissue, spontaneous activity and energy expenditure in skeletal muscle.
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Affiliation(s)
- P. R. Patel
- Center for Diabetes and Endocrine Research, College of Medicine and Life Sciences, University of Toledo, Health Science Campus, 3000 Arlington Avenue, Mail Stop 1009, Toledo, OH 43614, USA
- Department of Physiology and Pharmacology at the College of Medicine and Life Sciences, University of Toledo, Health Science Campus, Toledo, OH, USA
| | - S. K. Ramakrishnan
- Center for Diabetes and Endocrine Research, College of Medicine and Life Sciences, University of Toledo, Health Science Campus, 3000 Arlington Avenue, Mail Stop 1009, Toledo, OH 43614, USA
- Department of Physiology and Pharmacology at the College of Medicine and Life Sciences, University of Toledo, Health Science Campus, Toledo, OH, USA
| | - M. K. Kaw
- Center for Diabetes and Endocrine Research, College of Medicine and Life Sciences, University of Toledo, Health Science Campus, 3000 Arlington Avenue, Mail Stop 1009, Toledo, OH 43614, USA
- Department of Physiology and Pharmacology at the College of Medicine and Life Sciences, University of Toledo, Health Science Campus, Toledo, OH, USA
| | - C. K. Raphael
- Center for Diabetes and Endocrine Research, College of Medicine and Life Sciences, University of Toledo, Health Science Campus, 3000 Arlington Avenue, Mail Stop 1009, Toledo, OH 43614, USA
- Department of Physiology and Pharmacology at the College of Medicine and Life Sciences, University of Toledo, Health Science Campus, Toledo, OH, USA
| | - S. Ghosh
- Center for Diabetes and Endocrine Research, College of Medicine and Life Sciences, University of Toledo, Health Science Campus, 3000 Arlington Avenue, Mail Stop 1009, Toledo, OH 43614, USA
- Department of Physiology and Pharmacology at the College of Medicine and Life Sciences, University of Toledo, Health Science Campus, Toledo, OH, USA
| | - J. S. Marino
- Center for Diabetes and Endocrine Research, College of Medicine and Life Sciences, University of Toledo, Health Science Campus, 3000 Arlington Avenue, Mail Stop 1009, Toledo, OH 43614, USA
- Department of Physiology and Pharmacology at the College of Medicine and Life Sciences, University of Toledo, Health Science Campus, Toledo, OH, USA
| | - G. Heinrich
- Center for Diabetes and Endocrine Research, College of Medicine and Life Sciences, University of Toledo, Health Science Campus, 3000 Arlington Avenue, Mail Stop 1009, Toledo, OH 43614, USA
- Department of Physiology and Pharmacology at the College of Medicine and Life Sciences, University of Toledo, Health Science Campus, Toledo, OH, USA
| | - S. J. Lee
- Center for Diabetes and Endocrine Research, College of Medicine and Life Sciences, University of Toledo, Health Science Campus, 3000 Arlington Avenue, Mail Stop 1009, Toledo, OH 43614, USA
- Department of Physiology and Pharmacology at the College of Medicine and Life Sciences, University of Toledo, Health Science Campus, Toledo, OH, USA
| | - R. E. Bourey
- Center for Diabetes and Endocrine Research, College of Medicine and Life Sciences, University of Toledo, Health Science Campus, 3000 Arlington Avenue, Mail Stop 1009, Toledo, OH 43614, USA
- Department of Internal Medicine at the College of Medicine and Life Sciences, University of Toledo, Health Science Campus, Toledo, OH, USA
| | - J. W. Hill
- Center for Diabetes and Endocrine Research, College of Medicine and Life Sciences, University of Toledo, Health Science Campus, 3000 Arlington Avenue, Mail Stop 1009, Toledo, OH 43614, USA
- Department of Physiology and Pharmacology at the College of Medicine and Life Sciences, University of Toledo, Health Science Campus, Toledo, OH, USA
| | - D. Y. Jung
- Department of Cellular and Molecular Physiology, Pennsylvania State University College of Medicine, Hershey, PA, USA
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA, USA
| | - D. A. Morgan
- Department of Internal Medicine, University of Iowa Carver College of Medicine, Iowa City, IA, USA
| | - J. K. Kim
- Department of Cellular and Molecular Physiology, Pennsylvania State University College of Medicine, Hershey, PA, USA
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA, USA
| | - S. K. Rahmouni
- Department of Internal Medicine, University of Iowa Carver College of Medicine, Iowa City, IA, USA
| | - S. M. Najjar
- Center for Diabetes and Endocrine Research, College of Medicine and Life Sciences, University of Toledo, Health Science Campus, 3000 Arlington Avenue, Mail Stop 1009, Toledo, OH 43614, USA,
- Department of Physiology and Pharmacology at the College of Medicine and Life Sciences, University of Toledo, Health Science Campus, Toledo, OH, USA
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Cahova M, Palenickova E, Papackova Z, Dankova H, Skop V, Kazdova L. Epinephrine-dependent control of glucose metabolism in white adipose tissue: the role of α- and β-adrenergic signalling. Exp Biol Med (Maywood) 2012; 237:211-8. [PMID: 22302710 DOI: 10.1258/ebm.2011.011189] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Epinephrine controls many important and sometimes opposite processes. This pleiotropic effect is achieved via coupling to different receptor/effector systems. In epididymal white adipose tissue (EWAT) of Wistar rats, we showed that epinephrine stimulated protein kinase B (PKB) phosphorylation on Ser(473). Epinephrine further increased the glucose incorporation into glyceride-glycerol without decreasing glucose availability for other metabolic pathways (i.e. lactate production). Wortmannin (phosphatidylinositol 3-kinase inhibitor) treatment significantly decreased glucose incorporation into glyceride-glycerol and elevated the epinephrine-induced release of free fatty acids (FFA) from the adipose tissue without any change in the intensity of lipolysis measured as glycerol release. Using specific cyclic adenosine monophosphate (cAMP) analogs we demonstrated that cAMP-protein kinase A (PKA) signalling resulted in a strong PKB dephosphorylation and significantly lowered the glucose availability in EWAT. Specific activation of the Epac (exchange protein activated by cAMP)-dependent pathway had only a moderately negative effect on PKB phosphorylation and glucose metabolism. In contrast, α(1) agonist methoxamine increased PKB phosphorylation and lactate production. This effect of methoxamine was additive to the effect of insulin and it was abolished by wortmannin treatment. In EWAT of spontaneously dyslipidemic hereditary hypertriglyceridemic (HHTg) rats, we demonstrated significantly lower epinephrine-induced glucose utilization but higher sensitivity to its lipolytic effect. We conclude that in EWAT, epinephrine controls two opposite processes (FFA release and FFA retention) via two different effector systems. The impairment of α(1)-dependent, epinephrine-stimulated, glycolysis-dependent FFA esterification may contribute to the establishment of dyslipidemia in insulin resistance.
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Affiliation(s)
- Monika Cahova
- Department of Metabolism and Diabetes, Institute for Clinical and Experimental Medicine, Videnska 1958/9, Prague 4, Czech Republic.
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Mattsson CL, Csikasz RI, Chernogubova E, Yamamoto DL, Hogberg HT, Amri EZ, Hutchinson DS, Bengtsson T. β₁-Adrenergic receptors increase UCP1 in human MADS brown adipocytes and rescue cold-acclimated β₃-adrenergic receptor-knockout mice via nonshivering thermogenesis. Am J Physiol Endocrinol Metab 2011; 301:E1108-18. [PMID: 21878665 DOI: 10.1152/ajpendo.00085.2011] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
With the finding that brown adipose tissue is present and negatively correlated to obesity in adult man, finding the mechanism(s) of how to activate brown adipose tissue in humans could be important in combating obesity, type 2 diabetes, and their complications. In mice, the main regulator of nonshivering thermogenesis in brown adipose tissue is norepinephrine acting predominantly via β(3)-adrenergic receptors. However, vast majorities of β(3)-adrenergic agonists have so far not been able to stimulate human β(3)-adrenergic receptors or brown adipose tissue activity, and it was postulated that human brown adipose tissue could be regulated instead by β(1)-adrenergic receptors. Therefore, we have investigated the signaling pathways, specifically pathways to nonshivering thermogenesis, in mice lacking β(3)-adrenergic receptors. Wild-type and β(3)-knockout mice were either exposed to acute cold (up to 12 h) or acclimated for 7 wk to cold, and parameters related to metabolism and brown adipose tissue function were investigated. β(3)-knockout mice were able to survive both acute and prolonged cold exposure due to activation of β(1)-adrenergic receptors. Thus, in the absence of β(3)-adrenergic receptors, β(1)-adrenergic receptors are effectively able to signal via cAMP to elicit cAMP-mediated responses and to recruit and activate brown adipose tissue. In addition, we found that in human multipotent adipose-derived stem cells differentiated into functional brown adipocytes, activation of either β(1)-adrenergic receptors or β(3)-adrenergic receptors was able to increase UCP1 mRNA and protein levels. Thus, in humans, β(1)-adrenergic receptors could play an important role in regulating nonshivering thermogenesis.
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MESH Headings
- Acclimatization/genetics
- Acclimatization/physiology
- Adipocytes, Brown/cytology
- Adipocytes, Brown/metabolism
- Animals
- Cell Differentiation/genetics
- Cell Differentiation/physiology
- Cells, Cultured
- Cold Temperature
- Down-Regulation/genetics
- Epistasis, Genetic/physiology
- Female
- Humans
- Ion Channels/genetics
- Ion Channels/metabolism
- Male
- Mice
- Mice, Knockout
- Mitochondrial Proteins/genetics
- Mitochondrial Proteins/metabolism
- Multipotent Stem Cells/cytology
- Multipotent Stem Cells/metabolism
- Receptors, Adrenergic, beta-1/genetics
- Receptors, Adrenergic, beta-1/metabolism
- Receptors, Adrenergic, beta-1/physiology
- Receptors, Adrenergic, beta-3/genetics
- Shivering/genetics
- Shivering/physiology
- Thermogenesis/genetics
- Thermogenesis/physiology
- Uncoupling Protein 1
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Affiliation(s)
- Charlotte L Mattsson
- Department of Physiology, The Wenner-Gren Institute, Arrhenius Laboratories F3, Stockholm University, Stockholm, Sweden
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Catus SL, Gibbs ME, Sato M, Summers RJ, Hutchinson DS. Role of β-adrenoceptors in glucose uptake in astrocytes using β-adrenoceptor knockout mice. Br J Pharmacol 2011; 162:1700-15. [PMID: 21138422 DOI: 10.1111/j.1476-5381.2010.01153.x] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
BACKGROUND AND PURPOSE β(1) -, β(2) - and β(3) -adrenoceptors determined by functional, binding and reverse transcription polymerase chain reaction (RT-PCR) studies are present in chick astrocytes and activation of β(2) - or β(3) -adrenoceptors increase glucose uptake. The aims of the present study are to identify which β-adrenoceptor subtypes are present in mouse astrocytes, the signal transduction mechanisms involved and whether β-adrenoceptor stimulation regulates glucose uptake. EXPERIMENTAL APPROACH Astrocytes were prepared from four mouse strains: FVB/N, DBA/1 crossed with C57BL/6J, β(3) -adrenoceptor knockout and β(1) β(2) -adrenoceptor knockout mice. RT-PCR and radioligand binding studies were used to determine β-adrenoceptor expression. Glucose uptake and cAMP were assayed to elucidate the signalling pathways involved. KEY RESULTS mRNAs for all three β-adrenoceptors were identified in astrocytes from wild-type mice. Radioligand binding studies identified that β(1) - and β(3) -adrenoceptors were predominant. cAMP studies showed that β(1) - and β(2) -adrenoceptors coupled to G(s) whereas β(3) -adrenoceptors coupled to both G(s) and G(i) . However, activation of any of the three β-adrenoceptors increased glucose uptake in mouse astrocytes. Interestingly, there was no functional compensation for receptor subtype loss in knockout animals. CONCLUSIONS AND IMPLICATIONS This study demonstrates that although β(1) -adrenoceptors are the predominant β-adrenoceptor in mouse astrocytes and are primarily responsible for cAMP production in response to β-adrenoceptor stimulation, β(3) -adrenoceptors are also present in mouse astrocytes and activation of β(2) - and β(3) -adrenoceptors increases glucose uptake in mouse astrocytes.
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Affiliation(s)
- Stephanie L Catus
- Department of Pharmacology, Monash University, Clayton, Victoria, Australia
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Abstract
The increasing prevalence of obesity and its comorbidities reflects the interaction of genes that favor the storage of excess energy as fat with an environment that provides ad libitum availability of energy-dense foods and encourages an increasingly sedentary lifestyle. Although weight reduction is difficult in and of itself, anyone who has ever lost weight will confirm that it is much harder to keep the weight off once it has been lost. The over 80% recidivism rate to preweight loss levels of body fatness after otherwise successful weight loss is due to the coordinate actions of metabolic, behavioral, neuroendocrine and autonomic responses designed to maintain body energy stores (fat) at a central nervous system-defined 'ideal'. This 'adaptive thermogenesis' creates the ideal situation for weight regain and is operant in both lean and obese individuals attempting to sustain reduced body weights. Much of this opposition to sustained weight loss is mediated by the adipocyte-derived hormone 'leptin'. The multiple systems regulating energy stores and opposing the maintenance of a reduced body weight illustrate that body energy stores in general and obesity in particular are actively 'defended' by interlocking bioenergetic and neurobiological physiologies. Important inferences can be drawn for therapeutic strategies by recognizing obesity as a disease in which the human body actively opposes the 'cure' over long periods of time beyond the initial resolution of symptomatology.
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Affiliation(s)
- M Rosenbaum
- Division of Molecular Genetics, Department of Pediatrics, Columbia University, College of Physicians and Surgeons, New York, NY, USA.
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37
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Holmström TE, Mattsson CL, Wang Y, Iakovleva I, Petrovic N, Nedergaard J. Non-transactivational, dual pathways for LPA-induced Erk1/2 activation in primary cultures of brown pre-adipocytes. Exp Cell Res 2010; 316:2664-75. [PMID: 20576526 DOI: 10.1016/j.yexcr.2010.05.029] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2010] [Revised: 05/21/2010] [Accepted: 05/24/2010] [Indexed: 12/17/2022]
Abstract
In many cell types, G-protein-coupled receptor (GPCR)-induced Erk1/2 MAP kinase activation is mediated via receptor tyrosine kinase (RTK) transactivation, in particular via the epidermal growth factor (EGF) receptor. Lysophosphatidic acid (LPA), acting via GPCRs, is a mitogen and MAP kinase activator in many systems, and LPA can regulate adipocyte proliferation. The mechanism by which LPA activates the Erk1/2 MAP kinase is generally accepted to be via EGF receptor transactivation. In primary cultures of brown pre-adipocytes, EGF can induce Erk1/2 activation, which is obligatory and determinant for EGF-induced proliferation of these cells. Therefore, we have here examined whether LPA, via EGF transactivation, can activate Erk1/2 in brown pre-adipocytes. We found that LPA could induce Erk1/2 activation. However, the LPA-induced Erk1/2 activation was independent of transactivation of EGF receptors (or PDGF receptors) in these cells (whereas in transformed HIB-1B brown adipocytes, the LPA-induced Erk1/2 activation indeed proceeded via EGF receptor transactivation). In the brown pre-adipocytes, LPA instead induced Erk1/2 activation via two distinct non-transactivational pathways, one G(i)-protein dependent, involving PKC and Src activation, the other, a PTX-insensitive pathway, involving PI3K (but not Akt) activation. Earlier studies showing LPA-induced Erk1/2 activation being fully dependent on RTK transactivation have all been performed in cell lines and transfected cells. The present study implies that in non-transformed systems, RTK transactivation may not be involved in the mediation of GPCR-induced Erk1/2 MAP kinase activation.
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Affiliation(s)
- Therese E Holmström
- Department of Physiology, The Wenner-Gren Institute, Stockholm University, SE-106 91 Stockholm, Sweden
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Merlin J, Evans BA, Csikasz RI, Bengtsson T, Summers RJ, Hutchinson DS. The M3-muscarinic acetylcholine receptor stimulates glucose uptake in L6 skeletal muscle cells by a CaMKK-AMPK-dependent mechanism. Cell Signal 2010; 22:1104-13. [PMID: 20206685 DOI: 10.1016/j.cellsig.2010.03.004] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2009] [Revised: 02/23/2010] [Accepted: 03/01/2010] [Indexed: 11/15/2022]
Abstract
The role of muscarinic acetylcholine receptors (mAChRs) in regulating glucose uptake in L6 skeletal muscle cells was investigated. [(3)H]-2-Deoxyglucose uptake was increased in differentiated L6 cells by insulin, acetylcholine, oxotremorine-M and carbachol. mAChR-mediated glucose uptake was inhibited by the AMPK inhibitor Compound C. Whole cell radioligand binding using [(3)H]-N-methyl scopolamine chloride identified mAChRs in differentiated but not undifferentiated L6 cells and M(3) mAChR mRNA was detected only in differentiated cells. M(3) mAChRs are Gq-coupled, and cholinergic stimulation by the mAChR agonists acetylcholine, oxotremorine-M and carbachol increased Ca(2+) in differentiated but not undifferentiated L6 cells. This was due to muscarinic but not nicotinic activation as responses were antagonised by the muscarinic antagonist atropine but not the nicotinic antagonist tubocurarine. Western blotting showed that both carbachol and the AMPK activator AICAR increased phosphorylation of the AMPKalpha subunit at Thr172, with responses to carbachol blocked by Compound C and the CaMKK inhibitor STO609 but not by the PI3K inhibitor wortmannin. AICAR-stimulated AMPK phosphorylation was not sensitive to STO-609, confirming that this compound inhibits CaMKK but not the classical AMPK kinase LKB1. The TAK1 inhibitor (5Z)-7-oxozeaenol and the G(i) inhibitor pertussis toxin both failed to block AMPK phosphorylation in response to carbachol. Using CHO-K1 cells stably expressing each of the mAChR subtypes (M(1)-M(4)), it was determined that only the M(1) and M(3) mAChRs phosphorylate AMPK, confirming a G(q)-dependent mechanism. This study demonstrates that activation of M(3) mAChRs in L6 skeletal muscle cells stimulates glucose uptake via a CaMKK-AMPK-dependent mechanism, independent of the insulin-stimulated pathway.
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Affiliation(s)
- Jon Merlin
- Department of Pharmacology, Monash Institute of Pharmaceutical Sciences, Monash University, Victoria, 3800, Australia
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Ziolkowski N, Grover AK. Functional linkage as a direction for studies in oxidative stress: α-adrenergic receptorsThis review is one of a selection of papers published in a Special Issue on Oxidative Stress in Health and Disease. Can J Physiol Pharmacol 2010; 88:220-32. [PMID: 20393587 DOI: 10.1139/y10-013] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
The α-adrenergic receptors (adrenoceptors) are activated by the endogenous agonists epinephrine and norepinephrine. They are G protein-coupled receptors that may be broadly classified into α1 (subclasses α1A, α1B, α1D) and α2 (subclasses α2A, α2B, α2C). The α1-adrenoceptors act by binding to Gαq subunits of the G proteins, causing activation of phospholipase C (PLC). PLC converts phosphatidylinositol 4,5-bisphosphate into inositol trisphosphate (IP3) and diacylglycerol (DAG), which have downstream effects on cytosolic Ca2+ concentration. The α2-adrenoceptors bind to Gαi thus inhibiting adenylyl cyclase and decreasing cAMP levels. DAG alters protein kinase C activity and cAMP activates protein kinase A. The downstream pathways of the two receptors may also interact. Activation of α1- and α2-adrenoceptors in vascular smooth muscle results in vasoconstriction. However, the densities of individual receptor subclasses vary between vessel beds or between vessels of various sizes within the same bed. In vasculature, the densities of adrenoceptor subclasses differ between conduit arteries and arterioles. These differences, along with differences in coupling mechanisms, allow for fine regulation of arterial blood flow. This diversity is enhanced by interactions resulting from homo- and heterodimer formation of the receptors, metabolic pathways, and kinases. Reactive oxygen species generated in pathologies may alter α1- and α2-adrenoceptor cascades, change vascular contractility, or cause remodeling of blood vessels. This review emphasizes the need for understanding the functional linkage between α-adrenoceptor subtypes, coupling, cross talk, and oxidative stress in cardiovascular pathologies.
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Affiliation(s)
- Natalia Ziolkowski
- Departments of Medicine and Biology, McMaster University, 1200 Main Street West, Hamilton, ON L8N 3Z5, Canada
| | - Ashok K. Grover
- Departments of Medicine and Biology, McMaster University, 1200 Main Street West, Hamilton, ON L8N 3Z5, Canada
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40
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Naghshin J, McGaffin KR, Witham WG, Mathier MA, Romano LC, Smith SH, Janczewski AM, Kirk JA, Shroff SG, O'Donnell CP. Chronic intermittent hypoxia increases left ventricular contractility in C57BL/6J mice. J Appl Physiol (1985) 2009; 107:787-93. [PMID: 19589954 DOI: 10.1152/japplphysiol.91256.2008] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Intermittent hypoxia (IH) commonly occurs in patients with obstructive sleep apnea and can cause a wide range of pathology, including reduced left ventricular (LV) ejection fraction in rats as determined by echocardiography, in rodent models. We utilized echocardiography and pressure-volume (PV) loop analyses to determine whether LV contractility was decreased in inbred C57BL/6J mice exposed to IH and whether blockade of beta-adrenergic receptors modified the response to hypoxia. Adult male 9- to 10-wk-old mice were exposed to 4 wk of IH (nadir inspired O(2) 5-6% at 60 cycles/h for 12 h during the light period) or intermittent air (IA) as control. A second group of animals were exposed to the same regimen of IH or IA, but in the presence of nonspecific beta-blockade with propranolol. Cardiac function was assessed by echocardiography and PV loop analyses, and mRNA and protein expression in ventricular homogenates was determined. Contrary to our expectations, we found with PV loop analyses that LV ejection fraction (63.4 +/- 3.5 vs. 50.5 +/- 2.6%, P = 0.015) and other measures of LV contractility were increased in IH-exposed animals compared with IA controls. There were no changes in contractile proteins, atrial natriuretic peptide levels, LV posterior wall thickness, or heart weight with IH exposure. However, cAMP levels were elevated after IH, and propranolol administration attenuated the increase in LV contractility induced by IH exposure. We conclude that, contrary to our hypothesis, 4 wk of IH exposure in C57BL/6J mice causes an increase in LV contractility that occurs independent of ventricular hypertrophy and is, in part, mediated by activation of cardiac beta-adrenergic pathways.
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Affiliation(s)
- Jahan Naghshin
- Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania 15213, USA
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Wuest M, Eichhorn B, Grimm MO, Wirth MP, Ravens U, Kaumann AJ. Catecholamines relax detrusor through beta 2-adrenoceptors in mouse and beta 3-adrenoceptors in man. J Pharmacol Exp Ther 2008; 328:213-22. [PMID: 18820136 DOI: 10.1124/jpet.108.142562] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
(-)-Isoproterenol [4-[1-hydroxy-2-[(1-methylethyl)amino]ethyl]-1,2-benzene diol hydrochloride] relaxes murine detrusor through beta-adrenoceptors (ARs); however, the beta-AR subtypes involved are unknown. beta(2)-ARs have been associated with caveolae, plasma-lemmal scaffolding domains that are absent in caveolin-1 (cav-1) knockout (KO) mice. Here, we studied detrusor responses in the absence and presence of beta-AR subtype-selective antagonists in wild-type (WT) and cav-1 KO mice. To inquire whether the murine detrusor model is relevant to man, beta-AR subtypes that mediate (-)-isoproterenol-evoked human detrusor relaxation were investigated. In WT mice, (-)-isoproterenol concentration-dependently relaxed the KCl (40 mM)-precontracted detrusor (-logEC(50)M = 8.04, E(max) = 62%). The effects of (-)-isoproterenol were surmountably antagonized by the beta(2)-AR-selective antagonist ICI 118,551 [(+/-)-1-[2,3-(dihydro-7-methyl-1H-inden-4-yl)oxy]-3-[(1-methylethyl)amino]-2-butanol] (pK(B) = 9.28) but not affected by the beta(1)-AR-selective antagonist CGP 20712 [1-[2-((3-carbamoyl-4-hydroxy)phenoxy)ethylamino]-3-[4-(1-methyl-4-trifluoromethyl-2-imidazolyl)phenoxy]-2-propanol] and beta(3)-AR-selective L-748,337 [(S)-M-[4-[2-[3-[3-[acetamidomethyl)phenoxy)-2-hydroxypropyl]-amino]-ethyl]-phenylbenzsulfonamide)], suggesting involvement of beta(2)-AR only. The cav-1 KO detrusor displayed significant contractile dysfunction. (-)-Isoproterenol was less potent and efficient in relaxing detrusor from cav-1 KO (-logEC(50)M, 7.76; E(max) = 44%), but ICI 118,551 caused similar antagonism (pK(B) = 9.15), suggesting that beta(2)-AR function persisted in cav-1 KO. The beta(3)-AR-selective antagonist L-748,337 in the presence of ICI 118,551 and CGP 20712 caused additional blockade of (-)-isoproterenol effects in cav-1 KO, consistent with a beta(3)-AR involvement during relaxation and suppression of this effect in WT. (-)-Isoproterenol relaxed human detrusor muscle precontracted with carbachol (-logEC(50)M = 6.39, E(max) = 52%). However, the effects of (-)-isoproterenol in human detrusor were not blocked by CGP 20712 or ICI 118,551 but antagonized by L-748,337 (pK(B) = 7.65). We conclude that murine detrusor relaxation occurs via beta(2)-AR, and loss of caveolae does not perturb beta(2)-AR function but unmasks an additional activation of beta(3)-AR. In contrast, detrusor relaxation in man is mediated exclusively via beta(3)-AR.
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Affiliation(s)
- Melinda Wuest
- Department of Pharmacology and Toxicology, Dresden University of Technology, Fetscher-strasse 74, 01307 Dresden, Germany.
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Hutchinson DS, Summers RJ, Bengtsson T. Regulation of AMP-activated protein kinase activity by G-protein coupled receptors: Potential utility in treatment of diabetes and heart disease. Pharmacol Ther 2008; 119:291-310. [DOI: 10.1016/j.pharmthera.2008.05.008] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2008] [Accepted: 05/27/2008] [Indexed: 12/25/2022]
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Role of beta-adrenoceptors in memory consolidation: beta3-adrenoceptors act on glucose uptake and beta2-adrenoceptors on glycogenolysis. Neuropsychopharmacology 2008; 33:2384-97. [PMID: 18046311 DOI: 10.1038/sj.npp.1301629] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Noradrenaline, acting via beta(2)- and beta(3)-adrenoceptors (AR), enhances memory formation in single trial-discriminated avoidance learning in day-old chicks by mechanisms involving changes in metabolism of glucose and/or glycogen. Earlier studies of memory consolidation in chicks implicated beta(3)- rather than beta(2)-ARs in enhancement of memory consolidation by glucose, but did not elucidate whether stimulation of glucose uptake or of glycolysis was responsible. This study examines the role of glucose transport in memory formation using central injection of the nonselective facilitative glucose transporter (GLUT) inhibitor cytochalasin B, the endothelial/astrocytic GLUT-1 inhibitor phloretin and the Na(+)/energy-dependent endothelial glucose transporter (SGLT) inhibitor phlorizin. Cytochalasin B inhibited memory when injected into the mesopallium (avian cortex) either close to or between 25 and 45 min after training, whereas phloretin and phlorizin only inhibited memory at 30 min. This suggested that astrocytic/endothelial (GLUT-1) transport is critical at the time of consolidation, whereas a different transporter, probably the neuronal glucose transporter (GLUT-3), is important at the time of training. Inhibition of glucose transport by cytochalasin B, phloretin, or phlorizin also interfered with beta(3)-AR-mediated memory enhancement 20 min posttraining, whereas inhibition of glycogenolysis interfered with beta(2)-AR agonist enhancement of memory. We conclude that in astrocytes (1) activities of both GLUT-1 and SGLT are essential for memory consolidation 30 min posttraining; (2) neuronal GLUT-3 is essential at the time of training; and (3) beta(2)- and beta(3)-ARs consolidate memory by different mechanisms; beta(3)-ARs stimulate central glucose transport, whereas beta(2)-ARs stimulate central glycogenolysis.
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Metabolic responses to BRL37344 and clenbuterol in soleus muscle and C2C12 cells via different atypical pharmacologies and beta2-adrenoceptor mechanisms. Br J Pharmacol 2008; 155:395-406. [PMID: 18552870 DOI: 10.1038/bjp.2008.244] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
BACKGROUND AND PURPOSE Picomolar concentrations of the beta3-adrenoceptor agonist BRL37344 stimulate 2-deoxyglucose uptake in soleus muscle via undefined receptors. Higher concentrations alter uptake, apparently via beta2-adrenoceptors. Effects of BRL37344 and beta2-adrenoceptor agonists are compared. EXPERIMENTAL APPROACH Mouse soleus muscles were incubated with 2-deoxy[1-(14)C]-glucose, [1-(14)C]-palmitate or [2-(14)C]-pyruvate, and BRL37344, beta2-adrenoceptor agonists and selective beta-adrenoceptor antagonists. Formation of 2-deoxy[1-(14)C]-glucose-6-phosphate or (14)CO2 was measured. 2-Deoxy[1-(14)C]-glucose uptake and beta-adrenoceptor mRNA were measured in C2C12 cells. KEY RESULTS 10 pM BRL37344, 10 pM clenbuterol and 100 pM salbutamol stimulated 2-deoxyglucose uptake in soleus muscle by 33-54%. The effect of BRL37344 was prevented by 1 microM atenolol but not by 300 nM CGP20712A or IC3118551, or 1 microM SR59230A; that of clenbuterol was prevented by ICI118551 but not atenolol. 10 nM BRL37344 stimulated 2-deoxyglucose uptake, whereas 100 nM clenbuterol and salbutamol inhibited uptake. These effects were blocked by ICI118551. Similar results were obtained in C2C12 cells, in which only beta2-adrenoceptor mRNA could be detected by RT-PCR. 10 nM BRL37344 and 10 pM clenbuterol stimulated muscle palmitate oxidation. In the presence of palmitate, BRL37344 no longer stimulated 2-deoxyglucose uptake and the effect of clenbuterol was not significant. CONCLUSIONS AND IMPLICATIONS Stimulation of glucose uptake by 10 pM BRL37344 and clenbuterol involves different atypical pharmacologies. Nanomolar concentrations of BRL37344 and clenbuterol, probably acting via beta2-adrenoceptors, have opposite effects on glucose uptake. The agonists preferentially stimulate fat rather than carbohydrate oxidation, but stimulation of endogenous fat oxidation cannot explain why 100 nM clenbuterol inhibited 2-deoxyglucose uptake.
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Hutchinson DS, Summers RJ, Gibbs ME. Energy metabolism and memory processing: role of glucose transport and glycogen in responses to adrenoceptor activation in the chicken. Brain Res Bull 2008; 76:224-34. [PMID: 18498935 DOI: 10.1016/j.brainresbull.2008.02.019] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2007] [Revised: 01/22/2008] [Accepted: 02/11/2008] [Indexed: 11/28/2022]
Abstract
From experiments using a discriminated bead task in young chicks, we have defined when and where adrenoceptors (ARs) are involved in memory modulation. All three ARs subtypes (alpha(1)-, alpha(2)- and beta-ARs) are found in the chick brain and in regions associated with memory. Glucose and glycogen are important in the role of memory consolidation in the chick since increasing glucose levels improves memory consolidation while inhibiting glucose transporters (GLUTs) or glycogen breakdown inhibits memory consolidation. The selective beta(3)-AR agonist CL316243 enhances memory consolidation by a glucose-dependent mechanism and the administration of the non-metabolized glucose analogue 2-deoxyglucose reduces the ability of CL316243 to enhance memory. Agents that reduce glucose uptake by GLUTs and its incorporation into the glycolytic pathway also reduce the effectiveness of CL316243, but do not alter the dose-response relationship to the beta(2)-AR agonist zinterol. However, beta(2)-ARs do have a role in memory related to glycogen breakdown and inhibition of glycogenolysis reduces the ability of zinterol to enhance memory. Both beta(2)- and beta(3)-ARs are found on astrocytes from chick forebrain, and the actions of beta(3)-ARs on glucose uptake, and beta(2)-ARs on the breakdown of glycogen is consistent with an effect on astrocytic metabolism at the time of memory consolidation 30 min after training. We have shown that both beta(2)- and beta(3)-ARs can increase glucose uptake in chick astrocytes but do so by different mechanisms. This review will focus on the role of ARs on memory consolidation and specifically the role of energy metabolism on AR modulation of memory.
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Affiliation(s)
- Dana S Hutchinson
- Department of Pharmacology, Monash University, Clayton, Victoria 3800, Australia.
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Role of alpha1-adrenoceptor subtypes in the effects of methylenedioxy methamphetamine (MDMA) on body temperature in the mouse. Br J Pharmacol 2007; 153:591-7. [PMID: 18037913 DOI: 10.1038/sj.bjp.0707590] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
BACKGROUND AND PURPOSE We have investigated the ability of alpha(1)-adrenoceptor antagonists to affect the hyperthermia produced by methylenedioxy methamphetamine (MDMA) in conscious mice. EXPERIMENTAL APPROACH Mice were implanted with temperature probes under ether anaesthesia and allowed 2 weeks recovery. MDMA (20 mg kg(-1)) was administered subcutaneously 30 min after vehicle or test antagonist or combination of antagonists and effects on body temperature monitored. KEY RESULTS Following vehicle, MDMA produced a hyperthermia, reaching a maximum increase of 1.8 degrees C at 140 min. Prazosin (0.1 mg kg(-1)) revealed an early significant hypothermia to MDMA of -1.94 degrees C. The alpha(1A)-adrenoceptor antagonist RS 100329 (0.1 mg kg(-1)), or the alpha(1D)-adrenoceptor antagonist BMY 7378 (0.5 mg kg(-1)) given alone, did not reveal a hypothermia to MDMA, but the combination of the two antagonists revealed a significant hypothermia to MDMA. The putative alpha(1B)-adrenoceptor antagonist cyclazosin (1 mg kg(-1)) also revealed a significant hypothermia to MDMA, but actions of cyclazosin at the other alpha(1)-adrenoceptor subtypes cannot be excluded. CONCLUSIONS AND IMPLICATIONS More than one subtype of alpha(1)-adrenoceptor is involved in a component of the hyperthermic response to MDMA in mouse, probably both alpha(1A)- and alpha(1D)-adrenoceptors, and removal of this alpha(1)-adrenoceptor-mediated component reveals an initial hypothermia.
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Hutchinson DS, Summers RJ, Gibbs ME. β2- and β3-Adrenoceptors activate glucose uptake in chick astrocytes by distinct mechanisms: a mechanism for memory enhancement? J Neurochem 2007; 103:997-1008. [PMID: 17680985 DOI: 10.1111/j.1471-4159.2007.04789.x] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Isoprenaline, acting at beta-adrenoceptors (ARs), enhances memory formation in single trial discriminated avoidance learning in day-old chicks by mechanisms involving alterations in glucose and glycogen metabolism. Earlier studies of memory consolidation in chicks indicated that beta3-ARs enhanced memory by increasing glucose uptake, whereas beta2-ARs enhance memory by increasing glycogenolysis. This study examines the ability of beta-ARs to increase glucose uptake in chick forebrain astrocytes. The beta-AR agonist isoprenaline increased glucose uptake in a concentration-dependent manner, as did insulin. Glucose uptake was increased by the beta2-AR agonist zinterol and the beta3-AR agonist CL316243, but not by the beta1-AR agonist RO363. In chick astrocytes, reverse transcription-polymerase chain reaction studies showed that beta1-, beta2-, and beta3-AR mRNA were present, whereas radioligand-binding studies showed the presence of only beta2- and beta3-ARs. beta-AR or insulin-mediated glucose uptake was inhibited by phosphatidylinositol-3 kinase and protein kinase C inhibitors, suggesting a possible interaction between the beta-AR and insulin pathways. However beta2- and beta3-ARs increase glucose uptake by two different mechanisms: beta2-ARs via a Gs-cAMP-protein kinase A-dependent pathway, while beta3-ARs via interactions with Gi. These results indicate that activation of beta2- and beta3-ARs causes glucose uptake in chick astrocytes by distinct mechanisms, which may be relevant for memory enhancement.
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MESH Headings
- Adrenergic beta-2 Receptor Agonists
- Adrenergic beta-3 Receptor Agonists
- Adrenergic beta-Agonists/pharmacology
- Animals
- Astrocytes/drug effects
- Astrocytes/metabolism
- Brain/cytology
- Brain/metabolism
- Cells, Cultured
- Chick Embryo
- Dioxoles/pharmacology
- Dose-Response Relationship, Drug
- Enzyme Inhibitors/pharmacology
- Ethanolamines/pharmacology
- GTP-Binding Protein alpha Subunits, Gi-Go/drug effects
- GTP-Binding Protein alpha Subunits, Gi-Go/metabolism
- GTP-Binding Protein alpha Subunits, Gs/drug effects
- GTP-Binding Protein alpha Subunits, Gs/metabolism
- Glucose/metabolism
- Glucose/pharmacokinetics
- Insulin/metabolism
- Insulin/pharmacology
- Isoproterenol/pharmacology
- Memory/drug effects
- Memory/physiology
- Phosphatidylinositol 3-Kinases/metabolism
- Phosphoinositide-3 Kinase Inhibitors
- Protein Kinase C/antagonists & inhibitors
- Protein Kinase C/metabolism
- RNA, Messenger/drug effects
- RNA, Messenger/metabolism
- Receptors, Adrenergic, beta-2/genetics
- Receptors, Adrenergic, beta-2/metabolism
- Receptors, Adrenergic, beta-3/genetics
- Receptors, Adrenergic, beta-3/metabolism
- Signal Transduction/drug effects
- Signal Transduction/physiology
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Functional domains of the mouse β3-adrenoceptor associated with differential G-protein coupling. Biochem Soc Trans 2007. [DOI: 10.1042/bst0371035] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Localization of G-protein-coupled receptors within membrane microdomains is associated with differential signalling pathway activation. We have shown that two mouse β3-AR (β3-adrenoceptor) isoforms encoded by alternatively spliced mRNAs differ in their signalling properties; the β3a-AR couples only with Gs, whereas the β3b-AR couples with both Gs and Gi. Our previous studies indicated that the β3a-AR is restrained from coupling with Gi due to the interaction of residues in the C-terminus with other protein(s). We have investigated the hypothesis that the β3a-AR interacts with caveolin. Disruption of caveolae in CHO (Chinese-hamster ovary)-K1 cells expressing wild-type β3a-ARs with filipin III, or mutation of a putative caveolin-binding site in the β3a-AR, causes cAMP accumulation to become PTX (pertussis toxin)-sensitive. Likewise, filipin treatment of mouse brown adipocytes that express endogenous β3a-ARs produces a substantial reduction in agonist-stimulated cAMP production that is rescued by pre-treatment with PTX. These studies suggest that β3a-ARs may be restricted to caveolae and that localization of the receptor may play a specific role in G-protein-mediated signalling.
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Gjesing AP, Andersen G, Albrechtsen A, Glümer C, Borch-Johnsen K, Jørgensen T, Hansen T, Pedersen O. Studies of associations between the Arg389Gly polymorphism of the beta1-adrenergic receptor gene (ADRB1) and hypertension and obesity in 7677 Danish white subjects. Diabet Med 2007; 24:392-7. [PMID: 17335470 DOI: 10.1111/j.1464-5491.2006.02031.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
AIMS Activation of the beta(1)-adrenergic receptor (ADRB1) causes increased lipolysis in adipose tissue and enhances cardiac output. Analysis of the association of the functional ADRB1 Arg389Gly variant with obesity and hypertension has given ambiguous results. To clarify the potential impact of this variant on obesity and hypertension in the general population, we examined the Arg389Gly variant in a relatively large-scale population-based study. METHODS Case-control studies and quantitative trait analyses were carried out in 7677 Danish Caucasians who were genotyped for the Arg389Gly variant (dbSNP rs1801253) using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. RESULTS A weak association between the Gly allele of the Arg389Gly variant and obesity was observed when comparing cases (n = 1540) defined as body mass index (BMI) > 30 kg/m(2) with control subjects (n = 6108) defined as BMI < or = 30 kg/m(2) for both allele frequencies (P = 0.05) and genotype distribution (P = 0.05). Case-control studies (cases n = 2518; control n = 3981) examining the effect on hypertension showed no association with allele frequencies (P = 0.3) or genotype distribution (P = 0.5); however, in the quantitative trait analyses, individuals carrying the Gly allele had slightly but significantly lower diastolic (Arg/Arg = 81.9 mmHg vs. Gly-allele carriers = 81.5 mmHg) and systolic (Arg/Arg = 129.4 mmHg vs. Gly-allele carriers = 128.8 mmHg) blood pressure as well as a lower mean arterial blood pressure. CONCLUSION Our results suggest that the Arg389Gly polymorphism does not have any clinically important impact on the pathogenesis of obesity in Danish white subjects. Furthermore, despite the observed minor influence on blood pressure, this variant is most likely not to be a major contributor to the development of hypertension.
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Yamamoto DL, Hutchinson DS, Bengtsson T. Beta(2)-Adrenergic activation increases glycogen synthesis in L6 skeletal muscle cells through a signalling pathway independent of cyclic AMP. Diabetologia 2007; 50:158-67. [PMID: 17119919 DOI: 10.1007/s00125-006-0484-0] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/27/2006] [Accepted: 09/01/2006] [Indexed: 01/05/2023]
Abstract
AIMS/HYPOTHESIS In skeletal muscle, the storage of glycogen by insulin is regulated by glycogen synthase, which is regulated by glycogen synthase kinase 3 (GSK3). Here we examined whether adrenergic receptor activation, which can increase glucose uptake, regulates glycogen synthesis in L6 skeletal muscle cells. METHODS We used L6 cells and measured glycogen synthesis (as incorporation of D: -[U-(14)C]glucose into glycogen) and GSK3 phosphorylation following adrenergic activation. RESULTS Insulin (negative logarithm of median effective concentration [pEC(50)] 8.2 +/- 0.3) and the beta-adrenergic agonist isoprenaline (pEC(50) 7.5 +/- 0.3) induced a twofold increase in glycogen synthesis in a concentration-dependent manner. The alpha(1)-adrenergic agonist cirazoline and alpha(2)-adrenergic agonist clonidine had no effect. Both insulin and isoprenaline phosphorylated GSK3. The beta-adrenergic effect on glycogen synthesis is mediated by beta(2)-adrenoceptors and not beta(1)-/beta(3)-adrenoceptors, and was not mimicked by 8-bromo-cyclic AMP or cholera toxin, and also was insensitive to pertussis toxin, indicating no involvement of cyclic AMP or inhibitory G-protein (G(i)) signalling in the beta(2)-adrenergic effect on glycogen synthesis. 12-O-tetra-decanoylphorbol-13-acetate (TPA) increased glycogen synthesis 2.5-fold and phosphorylated GSK3 fourfold. Inhibition of protein kinase C (PKC) isoforms with 12-(2-cyanoethyl)-6,7,12,13-tetrahydro-13-methyl-5-oxo-5H-indolo(2,3-a)pyrrollo(3,4-c)-carbazole (Gö6976; inhibits conventional and novel PKCs) or 2-[1-(3-dimethylaminopropyl)-5-methoxyindol-3-yl]-3-(1H-indol-3-yl)maleimide (Gö6983; inhibits conventional, novel and atypical PKCs) inhibited the stimulatory TPA effect, but did not significantly inhibit glycogen synthesis mediated by insulin or isoprenaline. Inhibition of phosphatidylinositol 3-kinase (PI3K) with wortmannin inhibited the effects of insulin and isoprenaline on glycogen synthesis. CONCLUSIONS/INTERPRETATION These results demonstrate that in L6 skeletal muscle cells adrenergic stimulation through beta(2)-adrenoceptors, but not involving cyclic AMP or G(i), activates a PI3K pathway that stimulates glycogen synthesis through GSK3.
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Affiliation(s)
- D L Yamamoto
- Department of Physiology, The Wenner-Gren Institute, Arrhenius Laboratories F3, Stockholm University, SE 10691, Stockholm, Sweden
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