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Dwaib HS, Michel MC. Is the β 3-Adrenoceptor a Valid Target for the Treatment of Obesity and/or Type 2 Diabetes? Biomolecules 2023; 13:1714. [PMID: 38136585 PMCID: PMC10742325 DOI: 10.3390/biom13121714] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2023] [Revised: 11/21/2023] [Accepted: 11/25/2023] [Indexed: 12/24/2023] Open
Abstract
β3-Adrenoceptors mediate several functions in rodents that could be beneficial for the treatment of obesity and type 2 diabetes. This includes promotion of insulin release from the pancreas, cellular glucose uptake, lipolysis, and thermogenesis in brown adipose tissue. In combination, they lead to a reduction of body weight in several rodent models including ob/ob mice and Zucker diabetic fatty rats. These findings stimulated drug development programs in various pharmaceutical companies, and at least nine β3-adrenoceptor agonists have been tested in clinical trials. However, all of these projects were discontinued due to the lack of clinically relevant changes in body weight. Following a concise historical account of discoveries leading to such drug development programs we discuss species differences that explain why β3-adrenoceptors are not a meaningful drug target for the treatment of obesity and type 2 diabetes in humans.
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Affiliation(s)
- Haneen S. Dwaib
- Department of Clinical Nutrition and Dietetics, Palestine Ahliya University, Bethlehem P.O. Box 1041, Palestine;
| | - Martin C. Michel
- Department of Pharmacology, University Medical Center, Johannes Gutenberg University, Langenbeckstr. 1, 55131 Mainz, Germany
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2
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Chatzitomaris A, Hoermann R, Midgley JE, Hering S, Urban A, Dietrich B, Abood A, Klein HH, Dietrich JW. Thyroid Allostasis-Adaptive Responses of Thyrotropic Feedback Control to Conditions of Strain, Stress, and Developmental Programming. Front Endocrinol (Lausanne) 2017; 8:163. [PMID: 28775711 PMCID: PMC5517413 DOI: 10.3389/fendo.2017.00163] [Citation(s) in RCA: 89] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/13/2017] [Accepted: 06/27/2017] [Indexed: 12/21/2022] Open
Abstract
The hypothalamus-pituitary-thyroid feedback control is a dynamic, adaptive system. In situations of illness and deprivation of energy representing type 1 allostasis, the stress response operates to alter both its set point and peripheral transfer parameters. In contrast, type 2 allostatic load, typically effective in psychosocial stress, pregnancy, metabolic syndrome, and adaptation to cold, produces a nearly opposite phenotype of predictive plasticity. The non-thyroidal illness syndrome (NTIS) or thyroid allostasis in critical illness, tumors, uremia, and starvation (TACITUS), commonly observed in hospitalized patients, displays a historically well-studied pattern of allostatic thyroid response. This is characterized by decreased total and free thyroid hormone concentrations and varying levels of thyroid-stimulating hormone (TSH) ranging from decreased (in severe cases) to normal or even elevated (mainly in the recovery phase) TSH concentrations. An acute versus chronic stage (wasting syndrome) of TACITUS can be discerned. The two types differ in molecular mechanisms and prognosis. The acute adaptation of thyroid hormone metabolism to critical illness may prove beneficial to the organism, whereas the far more complex molecular alterations associated with chronic illness frequently lead to allostatic overload. The latter is associated with poor outcome, independently of the underlying disease. Adaptive responses of thyroid homeostasis extend to alterations in thyroid hormone concentrations during fetal life, periods of weight gain or loss, thermoregulation, physical exercise, and psychiatric diseases. The various forms of thyroid allostasis pose serious problems in differential diagnosis of thyroid disease. This review article provides an overview of physiological mechanisms as well as major diagnostic and therapeutic implications of thyroid allostasis under a variety of developmental and straining conditions.
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Affiliation(s)
- Apostolos Chatzitomaris
- Medical Department I, Endocrinology and Diabetology, Bergmannsheil University Hospitals, Ruhr University of Bochum, Bochum, Germany
- *Correspondence: Apostolos Chatzitomaris,
| | - Rudolf Hoermann
- Private Consultancy, Research and Development, Yandina, QLD, Australia
| | | | - Steffen Hering
- Department for Internal Medicine, Cardiology, Endocrinology, Diabetes and Medical Intensive Care Medicine, Krankenhaus Bietigheim-Vaihingen, Bietigheim-Bissingen, Germany
| | - Aline Urban
- Department for Anesthesiology, Intensive Care and Palliative Medicine, Eastern Allgäu-Kaufbeuren Hospitals, Kaufbeuren, Germany
| | | | - Assjana Abood
- Medical Department I, Endocrinology and Diabetology, Bergmannsheil University Hospitals, Ruhr University of Bochum, Bochum, Germany
| | - Harald H. Klein
- Medical Department I, Endocrinology and Diabetology, Bergmannsheil University Hospitals, Ruhr University of Bochum, Bochum, Germany
- Ruhr Center for Rare Diseases (CeSER), Ruhr University of Bochum and Witten/Herdecke University, Bochum, Germany
| | - Johannes W. Dietrich
- Medical Department I, Endocrinology and Diabetology, Bergmannsheil University Hospitals, Ruhr University of Bochum, Bochum, Germany
- Ruhr Center for Rare Diseases (CeSER), Ruhr University of Bochum and Witten/Herdecke University, Bochum, Germany
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3
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Liu J, Chen K, Valego NK, Carey LC, Rose JC. Ontogeny and effects of thyroid hormone on beta1-adrenergic receptor mRNA expression in ovine fetal kidney cortex. ACTA ACUST UNITED AC 2006; 12:563-9. [PMID: 16325745 DOI: 10.1016/j.jsgi.2005.08.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2005] [Indexed: 11/16/2022]
Abstract
OBJECTIVE Previous studies indicate that thyroidectomy (TX) decreases renin gene expression in ovine fetal renal cortex in late gestation. Fetal ovine renin-containing renocortical cells become increasingly responsive to beta-adrenergic stimulation as gestation proceeds. Increases in plasma thyroid hormone concentrations parallel this change, suggesting that there is a positive developmental relationship between the two. To examine this hypothesis, we determined the ontogeny of beta1-adrenergic receptor (beta1R) mRNA expression, and the effect of thyroid hormone on in vivo and in vitro expression in fetal sheep. METHODS Renocortical tissue was obtained from naive, TX, and sham-operated fetuses to determine beta1R mRNA levels. Renin-containing renocortical cells from TX or sham fetuses were treated with isoproterenol (Iso) or forskolin (FSK) for analysis of cellular cyclic adenosine monophosphate (cAMP) levels. Renocortical cells from naive fetuses were treated with triiodothyronine (T3) to assess cellular beta1R mRNA levels. Fetal plasma thyroxine (T4) level was determined. RESULTS Renocortical beta1R mRNA expression increased significantly between 100 and 140 days' gestational age (dGA), while TX attenuated this increase (P <.01). Renocortical cellular cAMP levels were higher in sham compared to TX fetuses following incubation with Iso or FSK (P <.05). Cells incubated with T3 exhibited significantly increased beta1R mRNA expression (P <.05). CONCLUSION The data suggest that thyroid hormone may be involved in modulating ovine fetal renocortical beta1R gene expression during development. We speculate that the increased beta1R mRNA expression in renal cortical cells as development progresses may mediate the increases in renin gene response to beta-adrenergic stimulation in late gestation.
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Affiliation(s)
- Jingfang Liu
- Department of Obstetrics and Gynecology, Wake Forest University School of Medicine, Winston-Salem, North Carolina 27157, USA
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4
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Ogasawara J, Sanpei M, Rahman N, Sakurai T, Kizaki T, Hitomi Y, Ohno H, Izawa T. Beta-adrenergic receptor trafficking by exercise in rat adipocytes: roles of G-protein-coupled receptor kinase-2, beta-arrestin-2, and the ubiquitin-proteasome pathway. FASEB J 2005; 20:350-2. [PMID: 16368719 DOI: 10.1096/fj.05-4688fje] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The effect of exercise on beta-adrenergic receptor (beta-AR) trafficking was investigated in rat adipocytes. The binding sites of a hydrophilic ligand, [(3)H]CGP12177, increased immediately (0 h) and at 3 h after exercise (3 h) but decreased at 24 h after exercise (24 h). The data of immunoblotting revealed that the alterations in the binding sites mainly paralleled the alterations in the beta2-AR proteins in membrane fractions. The protein expressions of both G-protein-coupled receptor kinase (GRK)-2 and beta-arrestin-2 were reduced, with a decline in beta2-AR ubiquitination at 0 h and 3 h. The protein expressions of beta2-AR, GRK-2, beta-arrestin-2, the beta2-AR/beta-arrestin-2 complex, and beta2-AR ubiquitination returned to their respective control levels at 24 h, whereas the beta2-AR mRNA level was reduced. Administration of either lactacystin or propranolol did not alter GRK-2 and beta2-AR protein expressions after exercise. Thus, the mechanism underlying the increased density of beta2-AR up to at least 3 h may involve alterations in a multistep event involving the coordinate interaction among proteins mediating beta2-AR trafficking, in which both the receptor-agonist interactions and ubiquitin-proteasome pathway have a key role. However, the decreased protein expression of beta2-AR at 24 h might be due to some change occurring at the translational levels.
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Affiliation(s)
- Junetsu Ogasawara
- Department of Kinesiology, Graduate School of Science, Tokyo Metropolitan University, Hachioji, Tokyo, Japan
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Klecha AJ, Barreiro Arcos ML, Genaro AM, Gorelik G, Silberman DM, Caro R, Cremaschi GA. Different mitogen-mediated Beta-adrenergic receptor modulation in murine T lymphocytes depending on the thyroid status. Neuroimmunomodulation 2005; 12:92-9. [PMID: 15785111 DOI: 10.1159/000083581] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/12/2003] [Accepted: 05/25/2004] [Indexed: 11/19/2022] Open
Abstract
OBJECTIVE The aim of this work was to analyze beta-adrenergic receptor (betaAR) regulation of T-lymphocyte proliferation in mice according to different thyroid hormone statuses. METHODS T cells from eu-, hypo- (by propylthiouracil treatment) and hyperthyroid (by thyroxine, T4 administration) mice were purified and specific radioligand binding assays were performed. The effects of the beta-agonist isoproterenol (ISO) on intracellular levels of cyclic AMP (cAMP) were determined. Mitogen-induced T-cell proliferation was measured by [(3)H]-thymidine incorporation. Finally, protein kinase C (PKC) activity in cytosol and membrane fractions were determined using radiolabelled enzymatic substrates. RESULTS Adecrease or a non-significant increase in betaAR number was found on T lymphocytes from hypo- and hyperthyroid mice compared to euthyroid controls. ISO stimulation of cAMP levels was lower in hypothyroid and higher in hyperthyroid T lymphocytes compared to controls. T-selective mitogen-induced proliferation was increased in T4-treated animals, but decreased in hypothyroid mice. During the peak of proliferation, downregulation of betaAR was observed in all animals. However, a higher or a lower decrease was observed in hyper- and hypothyroid T cells, respectively. In parallel, a higher translocation of PKC activity was observed in hyperthyroid cells, and a lower one was found in hypothyroid lymphocytes with respect to controls. CONCLUSIONS These results indicate that intracellular signals triggered by mitogen activation, namely PKC, would be related to differential betaAR downregulation in T lymphocytes depending on the thyroid hormone status, contributing to the distinct proliferative responses found in hypo- or hyperthyroidism compared to the euthyroid state.
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Affiliation(s)
- Alicia Juana Klecha
- Laboratorio de Radioisótopos, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Buenos Aires, Argentina
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6
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Mori K, Ozaki E, Zhang B, Yang L, Yokoyama A, Takeda I, Maeda N, Sakanaka M, Tanaka J. Effects of norepinephrine on rat cultured microglial cells that express alpha1, alpha2, beta1 and beta2 adrenergic receptors. Neuropharmacology 2002; 43:1026-34. [PMID: 12423672 DOI: 10.1016/s0028-3908(02)00211-3] [Citation(s) in RCA: 160] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Microglial cells rapidly become activated in response to even minor damage of neurons, suggestive of the intimate interactions between neurons and microglial cells. Although mediators for microglia-neuron interactions have not been well identified, neurotransmitters are possible candidates transmitting signals from neurons to microglial cells. Among the neurotransmitters, we focused on the effects of norepinephrine and other adrenergic agonists on the functions of rat cultured microglial cells. Reverse transcriptase polymerase chain reaction studies revealed that microglial cells expressed mRNAs encoding alpha1A, alpha2A, beta1 and beta2 receptors. Norepinephrine and a beta2 adrenergic agonist terbutaline elevated intracellular cAMP level of microglial cells. Norepinephrine, an alpha1 agonist phenylephrine, a beta1 agonist dobutamine and terbutaline suppressed the expressions of mRNAs encoding pro-inflammatory cytokines, interleukin-6 and tumor necrosis factor alpha. Release of tumor necrosis factor alpha and nitric oxide was suppressed by norepinephrine, phenylephrine, dobutamine and terbutaline. An alpha2 agonist clonidine and dobutamine upregulated the expression of mRNA encoding catechol-O-methyl transferase, an important enzyme to degrade norepinephrine. Norepinephrine, dobutamine and terbutaline upregulated the expressions of mRNA encoding 3-phospshoglycerate dehydrogenase, an essential enzyme for synthesis of L-serine and glycine, which are amino acids necessary for neuronal survival. Clonidine upregulated the expression of mRNA encoding an anti-apoptotic factor Bcl-xL. These results suggest that norepinephrine participates in the regulation of brain function at least partly by modulating the functions of microglia.
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MESH Headings
- Adrenergic alpha-Agonists/pharmacology
- Adrenergic beta-Agonists/pharmacology
- Animals
- Cells, Cultured
- Clonidine/pharmacology
- Cyclic AMP
- Dobutamine/pharmacology
- Dose-Response Relationship, Drug
- Exoribonucleases
- Interleukin-6
- Microglia/drug effects
- Microglia/metabolism
- Nitrites
- Norepinephrine/pharmacology
- Oligonucleotides, Antisense/pharmacology
- Phenylephrine/pharmacology
- RNA, Messenger/analysis
- Rats
- Receptors, Adrenergic, alpha-1/drug effects
- Receptors, Adrenergic, alpha-1/genetics
- Receptors, Adrenergic, alpha-1/metabolism
- Receptors, Adrenergic, alpha-2/drug effects
- Receptors, Adrenergic, alpha-2/genetics
- Receptors, Adrenergic, alpha-2/metabolism
- Receptors, Adrenergic, beta-1/drug effects
- Receptors, Adrenergic, beta-1/genetics
- Receptors, Adrenergic, beta-1/metabolism
- Receptors, Adrenergic, beta-2/drug effects
- Receptors, Adrenergic, beta-2/genetics
- Receptors, Adrenergic, beta-2/metabolism
- Reverse Transcriptase Polymerase Chain Reaction/methods
- Terbutaline/pharmacology
- Tumor Necrosis Factor-alpha
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Affiliation(s)
- Kohji Mori
- Department of Physiology, School of Medicine, Ehime University, Shigenobu, Ehime 791-0295, Japan
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7
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Mory G, Wiel M, Adli H, Diot-Dupuy F, Ferré P, Bazin R. Impaired beta-adrenergic signaling pathway in white adipocytes of suckling fa/fa Zucker rats: a defect in receptor coupling. Int J Obes (Lond) 2001; 25:1592-8. [PMID: 11753576 DOI: 10.1038/sj.ijo.0801811] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/22/2000] [Revised: 02/22/2001] [Accepted: 05/08/2001] [Indexed: 11/08/2022]
Abstract
BACKGROUND In fa/fa Zucker rats, leptin receptor deficiency is responsible for both a deficit of energy expenditure and hyperphagia which lead to massive obesity and insulin resistance in adulthood. This obesity is also characterised by alterations of the beta-adrenergic signaling pathway. OBJECTIVE To determine whether alterations in beta-adrenergic pathway could occur at the onset of obesity when fa/fa rats are not yet hyperinsulinemic. ANIMALS Fourteen-day-old suckling fa/fa and Fa/fa littermates (from heterozygous lean (Fa/fa) female and homozygous obese (fa/fa) male mating). MEASUREMENTS Membranes were prepared from isolated adipocytes after collagenase treatment of inguinal adipose tissue. The response of adenylyl-cyclase activity to stimulation by isoprenaline, GTPgamma-S or forskolin was studied. Bmax and Kd of (beta1+beta2) and of beta3 adrenoceptors were measured using 3H-CGP saturation binding experiments. mRNA concentration of beta1- and beta3-AR was determined by semi-quantitative RT-PCR. G(s)alpha protein was quantified by Western blotting and Gi protein by ADP-ribosylation. RESULTS Despite an almost normal body weight, inguinal fat pad weight was increased two-fold by the expression of fa mutation. This increase was entirely accounted for by fat cell hypertrophy (x2.5 in volume). In fa/fa compared to Fa/fa pups, response of adenylyl cyclase to isoprenaline was decreased two-fold but responses to GTPgammaS or forskolin were unchanged. Density of (beta1+beta2) and beta3-AR was not affected by the fa/fa genotype, as well as G(s)alpha and Gi concentration. CONCLUSION Response of inguinal fat cells to catecholamines was decreased without any quantitative modifications of the different elements of the adenylyl cyclase cascade. This suggests an alteration in the coupling between beta-AR and G proteins. Due to the important increase in fat cell volume we hypothesize that changes in the physical properties of plasma membranes and/or changes in cytoskeleton-extracellular-matrix interactions could disturb the beta-adrenergic pathway responsiveness. In addition to the excess of lipid storage, which occurs very early at the onset of obesity, the impairment of the responsiveness to catecholamines reported in this study might worsen the obesity syndrome.
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MESH Headings
- Adenylyl Cyclases/drug effects
- Adenylyl Cyclases/metabolism
- Adipocytes/drug effects
- Adipocytes/metabolism
- Animals
- Animals, Newborn
- Blotting, Western
- Catecholamines/pharmacology
- Colforsin/pharmacology
- Female
- GTP-Binding Protein alpha Subunits, Gi-Go/metabolism
- GTP-Binding Protein alpha Subunits, Gs/metabolism
- Guanosine 5'-O-(3-Thiotriphosphate)/pharmacology
- Isoproterenol/pharmacology
- Male
- Obesity/genetics
- Obesity/metabolism
- RNA, Messenger/metabolism
- Rats
- Rats, Zucker
- Receptors, Adrenergic, beta/drug effects
- Receptors, Adrenergic, beta/metabolism
- Reverse Transcriptase Polymerase Chain Reaction
- Signal Transduction/drug effects
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Affiliation(s)
- G Mory
- INSERM U 465, Centre Biomédical des Cordeliers, Paris, France
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8
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Margareto J, Larrarte E, Marti A, Martinez JA. Up-regulation of a thermogenesis-related gene (UCP1) and down-regulation of PPARgamma and aP2 genes in adipose tissue: possible features of the antiobesity effects of a beta3-adrenergic agonist. Biochem Pharmacol 2001; 61:1471-8. [PMID: 11377376 DOI: 10.1016/s0006-2952(01)00562-7] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
A number of experiments have demonstrated the antiobesity effects of beta(3)-adrenergic receptor stimulation by promoting thermogenesis and/or lipolysis. While many studies have been performed in order to develop beta(3)-adrenergic agonists as a novel strategy in the management of obesity, more information is needed about the mechanisms involved in thermogenesis and the actions of these drugs on adipocyte differentiation. To address this, the possible thermogenic and antiadipogenic properties of Tertatolol, a beta(3)-adrenergic agonist, in a diet-induced obesity model has been tested. Animals fed on a high-fat diet gained more weight and fat mass as compared with control and high-fat fed animals treated with Tertatolol. A RT-PCR was carried out in white adipose tissue specific genes involved in thermogenesis such as uncoupling proteins (UCPs) and adipogenesis such as peroxisome proliferator-activated receptor (PPARgamma2), retinoid receptors (RXRalpha/RARalpha), and fatty acid binding protein (aP2). Levels of UCP1 mRNA were augmented in the Tertatolol-treated group as compared to non-treated high-fat fed animals, while the beta(3)-adrenergic agonist treatment significantly decreased the expression levels of aP2 and transcription factors such as PPARgamma2 and the ratio RXRalpha/RARalpha as compared to obese rats. Altogether these data suggest that the antiobesity effects of beta(3)-adrenergic agonists are not limited to the promotion of thermogenesis and/or lipolysis and support the implication that these beta(3)-adrenergic agonists also affect fat deposition by impairing adipogenesis in white adipose tissue (WAT).
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Affiliation(s)
- J Margareto
- Department of Physiology and Nutrition, University of Navarra, Pamplona, Spain
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9
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Margareto J, Gómez-Ambrosi J, Marti A, Martínez JA. Time-dependent effects of a high-energy-yielding diet on the regulation of specific white adipose tissue genes. Biochem Biophys Res Commun 2001; 283:6-11. [PMID: 11322759 DOI: 10.1006/bbrc.2001.4733] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
White adipose tissue development is regulated by many factors, including the energy content of food and the genetic background. Nevertheless, little is known about possible differential effects of high-fat palatable diets when fed for short or long-time periods. Thus, the expression of certain genes involved with lipid metabolism (peroxisome proliferator-activated receptor gamma, PPARgamma2; retinoic receptors; fatty acid binding protein, aP2 and uncoupling proteins, UCP) may be affected by those dietary manipulations (high-energy-yielding diet and time duration of feeding). High-fat feeding for 8 days decreased mRNA UCP3 levels compared to control fed animals, while feeding for 30 days increased them over controls. Similar findings occurred for PPARgamma2 and aP2. Furthermore, statistically significant associations were found among PPARgamma2, aP2 and UCP3 mRNA levels. These data suggest a physiological time-dependent response seeking to prevent excessive fat deposition when animals are fed for short-term with a high amount of dietary fat, which was followed by an adaptive period to the high-energy content of diet throughout a coregulation among certain lipid metabolism related genes: PPARgamma2, aP2, UCP3.
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Affiliation(s)
- J Margareto
- Department of Physiology and Nutrition, University of Navarra, Pamplona, 31008, Spain
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10
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Abstract
Amiodarone is a benzofuranic-derivative iodine-rich drug widely used for the treatment of tachyarrhythmias and, to a lesser extent, of ischemic heart disease. It often causes changes in thyroid function tests (typically an increase in serum T(4) and rT(3), and a decrease in serum T(3), concentrations), mainly related to the inhibition of 5'-deiodinase activity, resulting in a decrease in the generation of T(3) from T(4) and a decrease in the clearance of rT(3). In 14-18% of amiodarone-treated patients, there is overt thyroid dysfunction, either amiodarone-induced thyrotoxicosis (AIT) or amiodarone-induced hypothyroidism (AIH). Both AIT and AIH may develop either in apparently normal thyroid glands or in glands with preexisting, clinically silent abnormalities. Preexisting Hashimoto's thyroiditis is a definite risk factor for the occurrence of AIH. The pathogenesis of iodine-induced AIH is related to a failure to escape from the acute Wolff-Chaikoff effect due to defects in thyroid hormonogenesis, and, in patients with positive thyroid autoantibody tests, to concomitant Hashimoto's thyroiditis. AIT is primarily related to excess iodine-induced thyroid hormone synthesis in an abnormal thyroid gland (type I AIT) or to amiodarone-related destructive thyroiditis (type II AIT), but mixed forms frequently exist. Treatment of AIH consists of L-T(4) replacement while continuing amiodarone therapy; alternatively, if feasible, amiodarone can be discontinued, especially in the absence of thyroid abnormalities, and the natural course toward euthyroidism can be accelerated by a short course of potassium perchlorate treatment. In type I AIT the main medical treatment consists of the simultaneous administration of thionamides and potassium perchlorate, while in type II AIT, glucocorticoids are the most useful therapeutic option. Mixed forms are best treated with a combination of thionamides, potassium perchlorate, and glucocorticoids. Radioiodine therapy is usually not feasible due to the low thyroidal radioiodine uptake, while thyroidectomy can be performed in cases resistant to medical therapy, with a slightly increased surgical risk.
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Affiliation(s)
- E Martino
- Dipartimento di Endocrinologia e Metabolismo, University of Pisa, Ospedale de Cisanello, via Paradisa, 2, 56124 Pisa, Italy.
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11
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Brown KJ, Summers RJ. beta(1)- and beta(3)-adrenoceptor mediated smooth muscle relaxation in hypothyroid rat ileum. Eur J Pharmacol 2001; 415:257-63. [PMID: 11275008 DOI: 10.1016/s0014-2999(01)00795-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The effect of hypothyroidism on gastrointestinal beta(1)- and beta(3)-adrenoceptor function and expression was examined in rat ileal smooth muscle preparations. (-)-Isoprenaline and the selective beta(3) agonist disodium (R,R)-5-[2-[[2-3-chlorophenyl)-2-hydroxyethyl]-amino]propyl]-1,3-benzodioxole-2,2-dicarboxylate (CL 316234) relaxed both control and hypothyroid tissues in a dose-dependent manner. Responses to isoprenaline were reduced in tissues from hypothyroid rats, as was the shift produced with the beta(3)-adrenoceptor antagonist, 3-(2-ethylphenoxy)-1-[(1S)-1,2,3,4-tetrahydronaphth-1-ylamino]-(2S)-2-propanol oxalate (SR 59230A). No change was seen in responses to CL 316243. Experiments with a selective beta(1)-adrenoceptor antagonist produced results suggesting that isoprenaline did not act at this receptor. Messenger RNA levels for both beta(1)- and beta(2)-adrenoceptors were not affected by hypothyroidism. These results show that, unlike in adipose tissues, ileal beta(1)- and beta(3)-adrenoceptors are not directly regulated by thyroid hormone and that beta(3)-adrenoceptor coupling to the relaxation response is reduced in a rat model of hypothyroidism.
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MESH Headings
- Adrenergic beta-Agonists/pharmacology
- Adrenergic beta-Antagonists/pharmacology
- Animals
- Dioxoles/pharmacology
- Hypothyroidism/chemically induced
- Hypothyroidism/metabolism
- Ileum/drug effects
- Ileum/metabolism
- Imidazoles/pharmacology
- Isoproterenol/pharmacology
- Male
- Muscle, Smooth/drug effects
- Muscle, Smooth/metabolism
- Propanolamines/pharmacology
- RNA, Messenger/drug effects
- RNA, Messenger/metabolism
- Rats
- Rats, Sprague-Dawley
- Receptors, Adrenergic, beta-1/drug effects
- Receptors, Adrenergic, beta-1/metabolism
- Receptors, Adrenergic, beta-3/drug effects
- Receptors, Adrenergic, beta-3/metabolism
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Affiliation(s)
- K J Brown
- Department of Pharmacology, Monash University, 3800, Victoria, Australia
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12
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Vassy R, Starzec A, Yin Y, Nicolas P, Perret GY. Amiodarone has exclusively non-genomic action on cardiac beta-adrenoceptor regulation. Eur J Pharmacol 2000; 408:227-32. [PMID: 11090638 DOI: 10.1016/s0014-2999(00)00793-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
The antiarrhythmic drug amiodarone down-regulates the density of cardiac beta-adrenoceptors behaving as a triiodothyronine (T(3)) antagonist. It is still unclear if amiodarone acts at the nuclear (genomic) and/or the non-genomic levels. Using Northern blot analysis, we showed that the amiodarone had no effect on the increase of beta(1)-adrenoceptor mRNA level induced by the T(3)-administration in the heart of thyroidectomised rats. Thus, our results suggest that amiodarone has no genomic effect. Consequently, we investigated whether amiodarone down-regulation of beta-adrenoceptor number in T(3)-stimulated cardiomyocytes could be explained by changes in the rate of cell surface receptor protein turnover. Indeed, the binding studies of cyclohexidemide-treated cells showed that amiodarone suppressed the T(3)-induced decrease in the rate of the cell surface receptor disappearance. In conclusion, our findings indicate that the modulation of cardiac beta-adrenoceptor density by amiodarone involves only non-genomic targets required in T(3)-dependent regulation of the cell surface beta-adrenoceptor turnover.
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MESH Headings
- Amiodarone/pharmacology
- Animals
- Anti-Arrhythmia Agents/pharmacology
- Cells, Cultured
- Chick Embryo
- Heart/growth & development
- Male
- Myocardium/cytology
- Myocardium/metabolism
- Organ Size/drug effects
- RNA/drug effects
- RNA/genetics
- RNA/metabolism
- RNA, Messenger/drug effects
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Rats
- Receptors, Adrenergic, beta-1/drug effects
- Receptors, Adrenergic, beta-1/genetics
- Receptors, Adrenergic, beta-1/metabolism
- Receptors, Cell Surface/drug effects
- Receptors, Cell Surface/metabolism
- Time Factors
- Triiodothyronine/pharmacology
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Affiliation(s)
- R Vassy
- Laboratoire de Pharmacologie Clinique et Experimentale, EA 2360, Faculté de Médecine, Université Paris-Nord, 74, rue Marcel Cachin, 93017 Cedex, Bobigny, France
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van Beeren HC, Bakker O, Wiersinga WM. Desethylamiodarone interferes with the binding of co-activator GRIP-1 to the beta 1-thyroid hormone receptor. FEBS Lett 2000; 481:213-6. [PMID: 11007966 DOI: 10.1016/s0014-5793(00)01970-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Ligand binding to the thyroid hormone nuclear receptor beta1 (TRbeta(1)) is inhibited by desethylamiodarone (DEA), the major metabolite of the widely used anti-arrhythmic drug amiodarone. Gene expression of thyroid hormone (triiodothyronine, T(3))-regulated genes can therefore be affected by amiodarone due to less ligand binding to the receptor. Previous studies have indicated the possibility of still other explanations for the inhibitory effects of amiodarone on T(3)-dependent gene expression, probably via interference with receptor/co-activator and co-repressor complex. The binding site of DEA is postulated to be on the outside surface of the receptor protein overlapping the regions where co-activator and co-repressor bind. Here we show the effect of a drug metabolite on the interaction of TRbeta(1) with the co-activator GRIP-1 (glucocorticoid receptor interacting protein-1). The T(3)-dependent binding of GRIP-1 to the TRbeta(1) is disrupted by DEA. A DEA dose experiment showed that the drug metabolite acts like an antagonist under 'normal' conditions (at 10(-7) M T(3) and 5x10(-6)-->10(-3) M DEA), but as an agonist under extreme conditions (at 0 and 10(-9) M T(3) and >10(-4) M DEA). To our knowledge, these results show for the first time that a metabolite of a drug which was not devised for this purpose can interfere with nuclear receptor/co-activator interaction.
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Affiliation(s)
- H C van Beeren
- Department of Endocrinology, Academic Medical Centre F5-171, University of Amsterdam, Meibergdreef 9, 1105 AZ, Amsterdam, The Netherlands.
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