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Kartinah NT, Anggraini S, Fadilah F, Rickie R. Hibiscus sabdariffa Linn. Extract Increases the mRNA Expression of the Arcuate Nucleus Leptin Receptor and is Predicted in silico as an Anti-obesity Agent. Curr Comput Aided Drug Des 2024; 20:811-821. [PMID: 37608673 DOI: 10.2174/1573409920666230822115144] [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: 03/11/2023] [Revised: 07/09/2023] [Accepted: 07/18/2023] [Indexed: 08/24/2023]
Abstract
BACKGROUND Leptin is predominant in regulating body weight by stimulating energy expenditure through its neuronal action in the brain. Moreover, it is projected to adipose tissue and induces adipocyte browning by activating the β3-adrenergic receptor (β3AR). However, the expression of leptin receptor (Lep-R) and β3AR in people with obesity is downregulated. AIM We hypothesized that Hibiscus sabdariffa Linn. extract (HSE) would increase hypothalamus arcuate nucleus (ARC) Lep-R and white adipose tissue (WAT) β3AR mRNA expression in DIO rats. This study also analyzed the potency of H. sabdariffa bioactive compounds as activators of Lep-R and β3AR by an in-silico experiment. METHODS Twenty-four male Sprague-Dawley rats were divided into four groups: Control (standard food), DIO (high-fat diet), DIO-Hib200 (HFD+HSE 200 mg/kg BW), and DIO-Hib400 (HFD+HSE400 mg/kg BW). HSE was administered orally for five weeks, once a day. RESULTS HSE administration significantly (p <0,05) increased the ARC Lep-R expression. The Lee index significantly decreased to the normal range (≤ 310) with p <0,001 for DIO-Hib200 and p <0,01 for DIO-Hib400. Among 39 bioactive compounds, 5-O-caffeoyl shikimic acid exhibited high free binding scores (-8,63) for Lep-R, and myricetin_3_arabinogalactoside had high free binding scores (-9,39) for β3AR. These binding predictions could activate Lep-R and β3AR. CONCLUSION This study highlights that HSE could be a potential therapeutic target for obesity by increasing LepR mRNA and leptin sensitivity, enhancing energy expenditure, and reducing obesity.
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Affiliation(s)
- Neng Tine Kartinah
- Departement of Medical Physiology, Faculty of Medicine, University of Indonesia, Jakarta, 10430, Indonesia
| | - Suci Anggraini
- Master's Programme in Biomedical Science, Faculty of Medicine, University of Indonesia, Jakarta, 10430, Indonesia
| | - Fadilah Fadilah
- Department of Chemistry, Faculty of Medicine, University of Indonesia, Jakarta, 10430, Indonesia
| | - Rickie Rickie
- Master's Programme in Biomedical Science, Faculty of Medicine, University of Indonesia, Jakarta, 10430, Indonesia
- Department of Medical Physiology, Faculty of Medicine and Health, Christian Krida Wacana, Jakarta, 11470, Indonesia
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Cozma D, Siatra P, Bornstein SR, Steenblock C. Sensitivity of the Neuroendocrine Stress Axis in Metabolic Diseases. Horm Metab Res 2024; 56:65-77. [PMID: 38171373 DOI: 10.1055/a-2201-6641] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/05/2024]
Abstract
Metabolic diseases are prevalent in modern society and have reached pandemic proportions. Metabolic diseases have systemic effects on the body and can lead to changes in the neuroendocrine stress axis, the critical regulator of the body's stress response. These changes may be attributed to rising insulin levels and the release of adipokines and inflammatory cytokines by adipose tissue, which affect hormone production by the neuroendocrine stress axis. Chronic stress due to inflammation may exacerbate these effects. The increased sensitivity of the neuroendocrine stress axis may be responsible for the development of metabolic syndrome, providing a possible explanation for the high prevalence of severe comorbidities such as heart disease and stroke associated with metabolic disease. In this review, we address current knowledge of the neuroendocrine stress axis in response to metabolic disease and discuss its role in developing metabolic syndrome.
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Affiliation(s)
- Diana Cozma
- Department of Medicine III, University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
| | - Panagiota Siatra
- Department of Medicine III, University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
| | - Stefan R Bornstein
- Department of Medicine III, University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
- School of Cardiovascular and Metabolic Medicine and Sciences, Faculty of Life Sciences & Medicine, King's College London, London, UK
- Department of Endocrinology, Diabetology and Clinical Nutrition, University Hospital Zurich (USZ) and University of Zurich (UZH), Zurich, Switzerland
| | - Charlotte Steenblock
- Department of Medicine III, University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
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3
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Willows JW, Gunsch G, Paradie E, Blaszkiewicz M, Tonniges JR, Pino MF, Smith SR, Sparks LM, Townsend KL. Schwann cells contribute to demyelinating diabetic neuropathy and nerve terminal structures in white adipose tissue. iScience 2023; 26:106189. [PMID: 36895649 PMCID: PMC9989657 DOI: 10.1016/j.isci.2023.106189] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2022] [Revised: 12/09/2022] [Accepted: 02/08/2023] [Indexed: 02/15/2023] Open
Abstract
Peripheral neuropathy, which can include axonal degeneration and/or demyelination, impacts adipose tissues with obesity, diabetes, and aging. However, the presence of demyelinating neuropathy had not yet been explored in adipose. Both demyelinating neuropathies and axonopathies implicate Schwann cells (SCs), a glial support cell that myelinates axons and contributes to nerve regeneration after injury. We performed a comprehensive assessment of SCs and myelination patterns of subcutaneous white adipose tissue (scWAT) nerves, and changes across altered energy balance states. We found that mouse scWAT contains both myelinated and unmyelinated nerves and is populated by SCs, including SCs that were associated with synaptic vesicle-containing nerve terminals. BTBR ob/ob mice, a model of diabetic peripheral neuropathy, exhibited small fiber demyelinating neuropathy and alterations in SC marker gene expression in adipose that were similar to obese human adipose. These data indicate that adipose SCs regulate the plasticity of tissue nerves and become dysregulated in diabetes.
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Affiliation(s)
- Jake W Willows
- Department of Neurological Surgery, The Ohio State University, Columbus, OH, USA
| | - Gilian Gunsch
- Department of Neurological Surgery, The Ohio State University, Columbus, OH, USA
| | - Emma Paradie
- Department of Neurological Surgery, The Ohio State University, Columbus, OH, USA
| | | | - Jeffrey R Tonniges
- Campus Microscopy and Imaging Facility, The Ohio State University, Columbus, OH, USA
| | - Maria F Pino
- Translational Research Institute, AdventHealth, Orlando, FL, USA
| | - Steven R Smith
- Translational Research Institute, AdventHealth, Orlando, FL, USA
| | - Lauren M Sparks
- Translational Research Institute, AdventHealth, Orlando, FL, USA
| | - Kristy L Townsend
- Department of Neurological Surgery, The Ohio State University, Columbus, OH, USA
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Song Q, Chen Y, Ding Q, Griffiths A, Liu L, Park J, Liew CW, Nieto N, Li S, Dou X, Jiang Y, Song Z. mTORC1 inhibition uncouples lipolysis and thermogenesis in white adipose tissue to contribute to alcoholic liver disease. Hepatol Commun 2023; 7:e0059. [PMID: 36757400 PMCID: PMC9915967 DOI: 10.1097/hc9.0000000000000059] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Accepted: 12/21/2022] [Indexed: 02/10/2023] Open
Abstract
BACKGROUND Adipose tissue thermogenic activities use fatty acids from lipolysis for heat generation. Therefore, a tight coupling between lipolysis and thermogenesis is physiologically imperative in maintaining not only body temperature but also lipids homeostasis. Adipose tissue dysfunction contributes to alcoholic liver disease (ALD). Here, studies were conducted to examine how alcohol intake affects adipose tissue thermogenic activities and whether altered adipose tissue thermogenesis contributes to ALD. METHODS Both the Lieber-DeCarli and the NIAAA mouse models of ALD were used. Denervation surgery in epididymal fat pads was performed. CL316,243, a selective β3-adrenoceptor agonist, SR59230A, a selective β3 adrenoceptor (ADRB3) antagonist, and rapamycin, a selective mechanistic target of rapamycin complex 1 (mTORC1) inhibitor, were administrated through i.p. injection. Adipocyte-specific Prdm16 knockout mice were subjected to alcohol-containing diet chronically. RESULTS Chronic alcohol consumption, which enhances adipose tissue lipolysis, inhibits thermogenic activities of beige adipocytes in inguinal white adipose tissue (WAT), leading to an uncoupling status between lipolysis and thermogenesis in WAT at both basal and ADRB3 stimulation states. CL316,243 administration exacerbates liver pathologies of ALD. Alcohol intake inhibits mTORC1 activities in WAT. In mice, mTORC1 inhibition by rapamycin inhibits the thermogenesis of iWAT, whereas enhancing WAT lipolysis. Further investigations using adipocyte-specific Prdm16 knockout mice revealed that functional deficiency of beige adipocytes aggravates liver pathologies of ALD, suggesting that the inhibitory effect of alcohol on WAT browning/thermogenesis contributes to ALD pathogenesis. CONCLUSION Chronic alcohol consumption induces an "uncoupling status" between lipolysis and browning/thermogenesis in WAT by inhibiting mTORC1 activation. Diminished WAT browning/thermogenesis, concomitant with enhanced lipolysis, contributes to ALD pathogenesis.
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Affiliation(s)
- Qing Song
- Department of Kinesiology and Nutrition, University of Illinois at Chicago, Chicago, Illinois, USA
| | - Yingli Chen
- Department of Kinesiology and Nutrition, University of Illinois at Chicago, Chicago, Illinois, USA
| | - Qinchao Ding
- College of Life Science, Zhejiang Chinese Medical University, Hangzhou, Zhejiang, China
| | - Alexandra Griffiths
- Department of Kinesiology and Nutrition, University of Illinois at Chicago, Chicago, Illinois, USA
| | - Lifeng Liu
- Department of Physiology and Biophysics, University of Illinois at Chicago, Chicago, Illinois, USA
| | - Jooman Park
- Department of Physiology and Biophysics, University of Illinois at Chicago, Chicago, Illinois, USA
| | - Chong Wee Liew
- Department of Physiology and Biophysics, University of Illinois at Chicago, Chicago, Illinois, USA
| | - Natalia Nieto
- Department of Pathology, University of Illinois at Chicago, Chicago, Illinois, USA
| | - Songtao Li
- College of Life Science, Zhejiang Chinese Medical University, Hangzhou, Zhejiang, China
| | - Xiaobing Dou
- College of Life Science, Zhejiang Chinese Medical University, Hangzhou, Zhejiang, China
| | - Yuwei Jiang
- Department of Physiology and Biophysics, University of Illinois at Chicago, Chicago, Illinois, USA
| | - Zhenyuan Song
- Department of Kinesiology and Nutrition, University of Illinois at Chicago, Chicago, Illinois, USA
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A co-crystal berberine-ibuprofen improves obesity by inhibiting the protein kinases TBK1 and IKKɛ. Commun Biol 2022; 5:807. [PMID: 35962183 PMCID: PMC9374667 DOI: 10.1038/s42003-022-03776-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2021] [Accepted: 07/27/2022] [Indexed: 11/09/2022] Open
Abstract
Berberine (BBR) exerts specific therapeutic effects on various diseases such as diabetes, obesity, and other inflammation-associated diseases. However, the low oral bioavailability (below 1%) of berberine due to its poor solubility and membrane permeability limits its clinical use. In this paper, we have prepared a 1:1 co-crystal berberine-ibuprofen (BJ) using drug salt metathesis and co-crystal technology. Pharmacokinetic studies demonstrate a 3-fold increase in vivo bioavailability of BJ compared to that of BBR, and BJ is more effective in treating obesity and its related metabolism in vitro and in vivo. We also find that BJ promotes mitochondrial biogenesis by inhibiting TBK1 and inducing AMP-activated protein kinase (AMPK) phosphorylation, and BJ increases adipocyte sensitivity to catecholamine by inhibiting IKKε. Together, our findings support that co-crystal BJ is likely to be an effective agent for treating obesity and its related metabolic diseases targeting TBK1 and IKKε.
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Marcoux C, Morin R, Mauger JF, Imbeault P. The Effect of Acute Intermittent and Continuous Hypoxia on Plasma Circulating ßOHB Levels Under Different Feeding Statuses in Humans. Front Physiol 2022; 13:937127. [PMID: 35874514 PMCID: PMC9298782 DOI: 10.3389/fphys.2022.937127] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Accepted: 06/15/2022] [Indexed: 11/13/2022] Open
Abstract
Introduction: Acute hypoxia is known to increase circulating nonesterified fatty acid (NEFA) levels. Adipose tissue lipolysis is a major source of NEFA into circulation and insulin suppresses this process when the tissue is insulin sensitive. NEFA can be esterified to triglycerides and/or completely/partially oxidized, the latter leading to ketogenesis in the liver. To our knowledge, the effect of hypoxia on ketogenesis, more specifically ß-hydroxybutyrate (ßOHB) levels, remains unknown in humans. Therefore, the objective of this study was to determine the effect of acute intermittent and continuous hypoxia on circulating ßOHB levels under different feeding status. Methods: Plasma samples from three different randomized crossover studies were assessed for ßOHB concentrations. In the first study, 14 healthy men (23 ± 3.5 years) were exposed to 6 h of normoxia or intermittent hypoxia (IH-Fed) (15 hypoxic events/hour) following an isocaloric meal. In the second study, 10 healthy men (26 ± 5.6 years) were exposed to 6 h of continuous normobaric hypoxia (CH-Fasted) (FiO2 = 0.12) or normoxia in the fasting state. In the third study (CH-Fed), 9 healthy men (24 ± 4.5 years) were exposed to 6 h of normoxia or CH in a constant prandial state. ßOHB, NEFA and insulin levels were measured during all sessions. Results: In the IH-Fed study, ßOHB and NEFA levels tended to be greater over 6 h of IH (condition × time interaction, ßOHB p = 0.108 and NEFA p = 0.062) compared to normoxia. In the CH-Fasted study, ßOHB and NEFA levels increased over time in both experimental conditions, this effect being greater under CH (condition × time interaction, ßOHB p = 0.070; NEFA p = 0.046). In the CH-Fed study, ßOHB levels slightly increased up to 180 min before falling back to initial concentrations by the end of the protocol in both normoxia and CH (main effect of time, p = 0.062), while NEFA were significantly higher under CH (p = 0.006). Conclusion: Acute normobaric hypoxia exposure tends to increase plasma ßOHB concentrations over time in healthy men. The stimulating effect of hypoxia on plasma ßOHB levels is however attenuated during postprandial and prandial states.
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Affiliation(s)
- Caroline Marcoux
- School of Human Kinetics, Faculty of Health Sciences, University of Ottawa, Ottawa, ON, Canada
| | - Renée Morin
- School of Human Kinetics, Faculty of Health Sciences, University of Ottawa, Ottawa, ON, Canada
| | - Jean-François Mauger
- School of Human Kinetics, Faculty of Health Sciences, University of Ottawa, Ottawa, ON, Canada
| | - Pascal Imbeault
- School of Human Kinetics, Faculty of Health Sciences, University of Ottawa, Ottawa, ON, Canada.,Institut du Savoir Montfort, Hôpital Montfort, Ottawa, ON, Canada
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7
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Musovic S, Komai AM, Said MK, Shrestha MM, Wu Y, Wernstedt Asterholm I, Olofsson CS. Noradrenaline and ATP regulate adiponectin exocytosis in white adipocytes: Disturbed adrenergic and purinergic signalling in obese and insulin-resistant mice. Mol Cell Endocrinol 2022; 549:111619. [PMID: 35337901 DOI: 10.1016/j.mce.2022.111619] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/19/2021] [Revised: 02/26/2022] [Accepted: 03/10/2022] [Indexed: 01/19/2023]
Abstract
White adipocyte adiponectin exocytosis is triggered by cAMP and a concomitant increase of cytosolic Ca2+ potentiates its release. White adipose tissue is richly innervated by sympathetic nerves co-releasing noradrenaline (NA) and ATP, which may act on receptors in the adipocyte plasma membrane to increase cAMP via adrenergic receptors and Ca2+ via purinergic receptors. Here we determine the importance of NA and ATP for the regulation of white adipocyte adiponectin exocytosis, at the cellular and molecular level, and we specifically detail the ATP signalling pathway. We demonstrate that tyrosine hydroxylase (enzyme involved in catecholamine synthesis) is dramatically reduced in inguinal white adipose tissue (IWAT) isolated from mice with diet-induced obesity; this is associated with diminished levels of NA in IWAT and with a reduced ratio of high-molecular-weight (HMW) to total adiponectin in serum. Adiponectin exocytosis (measured as an increase in plasma membrane capacitance and as secreted product) is triggered by NA or ATP alone in cultured and primary mouse IWAT adipocytes, and enhanced by a combination of the two secretagogues. The ATP-induced adiponectin exocytosis is largely Ca2+-dependent and activated via purinergic P2Y2 receptors (P2Y2Rs) and the Gq11/PLC pathway. Adiponectin release induced by the nucleotide is abrogated in adipocytes isolated from obese and insulin-resistant mice, and this is associated with ∼70% reduced abundance of P2Y2Rs. The NA-triggered adiponectin exocytosis is likewise abolished in "obese adipocytes", concomitant with a 50% lower gene expression of beta 3 adrenergic receptors (β3ARs). An increase in intracellular Ca2+ is not required for the NA-stimulated adiponectin secretion. Collectively, our data suggest that sympathetic innervation is a principal regulator of adiponectin exocytosis and that disruptions of this control are associated with the obesity-associated reduction of circulating levels of HMW/total adiponectin.
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Affiliation(s)
- Saliha Musovic
- Department of Physiology/Metabolic Physiology, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at University of Gothenburg, Medicinaregatan 11, SE-405 30, Göteborg, Sweden
| | - Ali M Komai
- Department of Physiology/Metabolic Physiology, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at University of Gothenburg, Medicinaregatan 11, SE-405 30, Göteborg, Sweden
| | - Marina Kalds Said
- Department of Physiology/Metabolic Physiology, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at University of Gothenburg, Medicinaregatan 11, SE-405 30, Göteborg, Sweden
| | - Man Mohan Shrestha
- Department of Physiology/Metabolic Physiology, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at University of Gothenburg, Medicinaregatan 11, SE-405 30, Göteborg, Sweden
| | - Yanling Wu
- Department of Physiology/Metabolic Physiology, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at University of Gothenburg, Medicinaregatan 11, SE-405 30, Göteborg, Sweden
| | - Ingrid Wernstedt Asterholm
- Department of Physiology/Metabolic Physiology, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at University of Gothenburg, Medicinaregatan 11, SE-405 30, Göteborg, Sweden
| | - Charlotta S Olofsson
- Department of Physiology/Metabolic Physiology, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at University of Gothenburg, Medicinaregatan 11, SE-405 30, Göteborg, Sweden.
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Reinisch I, Schreiber R, Prokesch A. Regulation of thermogenic adipocytes during fasting and cold. Mol Cell Endocrinol 2020; 512:110869. [PMID: 32439414 DOI: 10.1016/j.mce.2020.110869] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Revised: 05/11/2020] [Accepted: 05/12/2020] [Indexed: 12/13/2022]
Abstract
Cold exposure activates brown and brown-like adipocytes that dissipate large amounts of glucose and fatty acids via uncoupling protein 1 (UCP1) to drive non-shivering thermogenesis (NST). Evidence for the existence of these thermogenic adipocytes in adult humans gave rise to a renaissance in research on brown adipose tissue, establishing it as linchpin of energy homeostasis and metabolic health. Besides low ambient temperature, shortage or excess of food affect thermoregulation. Upon high caloric meals thermogenic adipocytes burn excess calories and maintain energy balance. In contrast, in conditions of nutrient deprivation, counter-regulatory mechanisms prevent thermogenic adipocytes from "wasting" energy substrates that need to be conserved. In this review, we discuss cell-autonomous mechanisms, metabolites, and hormones that modify NST in response to nutrient fluctuations. In particular, we focus on how thermogenic adipocytes balance thermogenesis with systemic energy homeostasis during fasting periods.
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Affiliation(s)
- Isabel Reinisch
- Division of Cell Biology, Histology and Embryology, Gottfried Schatz Research Center for Cell Signaling, Metabolism & Aging, Medical University of Graz, 8010, Graz, Austria
| | - Renate Schreiber
- Institute of Molecular Biosciences, University of Graz, 8010, Graz, Austria
| | - Andreas Prokesch
- Division of Cell Biology, Histology and Embryology, Gottfried Schatz Research Center for Cell Signaling, Metabolism & Aging, Medical University of Graz, 8010, Graz, Austria; BioTechMed-Graz, 8010, Graz, Austria.
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9
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Caron A, Reynolds RP, Castorena CM, Michael NJ, Lee CE, Lee S, Berdeaux R, Scherer PE, Elmquist JK. Adipocyte Gs but not Gi signaling regulates whole-body glucose homeostasis. Mol Metab 2019; 27:11-21. [PMID: 31279640 PMCID: PMC6717754 DOI: 10.1016/j.molmet.2019.06.019] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Revised: 06/20/2019] [Accepted: 06/20/2019] [Indexed: 01/24/2023] Open
Abstract
Objective The sympathetic nervous system (SNS) is a key regulator of the metabolic and endocrine functions of adipose tissue. Increased SNS outflow promotes fat mobilization, stimulates non-shivering thermogenesis, promotes browning, and inhibits leptin production. Most of these effects are attributed to norepinephrine activation of the Gs-coupled beta adrenergic receptors located on the surface of the adipocytes. Evidence suggests that other adrenergic receptor subtypes, including the Gi-coupled alpha 2 adrenergic receptors might also mediate the SNS effects on adipose tissue. However, the impact of acute stimulation of adipocyte Gs and Gi has never been reported. Methods We harness the power of chemogenetics to develop unique mouse models allowing the specific and spatiotemporal stimulation of adipose tissue Gi and Gs signaling. We evaluated the impact of chemogenetic stimulation of these pathways on glucose homeostasis, lipolysis, leptin production, and gene expression. Results Stimulation of Gs signaling in adipocytes induced rapid and sustained hypoglycemia. These hypoglycemic effects were secondary to increased insulin release, likely consequent to increased lipolysis. Notably, we also observed differences in gene regulation and ex vivo lipolysis in different adipose depots. In contrast, acute stimulation of Gi signaling in adipose tissue did not affect glucose metabolism or lipolysis, but regulated leptin production. Conclusion Our data highlight the significance of adipose Gs signaling in regulating systemic glucose homeostasis. We also found previously unappreciated heterogeneity across adipose depots following acute stimulation. Together, these results highlight the complex interactions of GPCR signaling in adipose tissue and demonstrate the usefulness of chemogenetic technology to better understand adipocyte function. Chemogenetic stimulation of Gs signaling in adipose tissue potently induces hypoglycemia in mice. The magnitude by which adipose Gs stimulation reduces blood glucose is similar to the hypoglycemic effects of insulin. Chemogenetic stimulation of Gs signaling in adipose tissue ex vivo stimulates lipolysis. Chemogenetic stimulation of adipose Gi signaling does not affect glycemia or lipolysis, but increases leptin levels. Our data demonstrate the usefulness of chemogenetic technology to understand adipocytes functions.
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Affiliation(s)
- Alexandre Caron
- Department of Internal Medicine, Division of Hypothalamic Research, University of Texas Southwestern Medical Center, Dallas, TX, USA.
| | - Ryan P Reynolds
- Department of Internal Medicine, Division of Hypothalamic Research, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Carlos M Castorena
- Department of Internal Medicine, Division of Hypothalamic Research, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Natalie J Michael
- Department of Internal Medicine, Division of Hypothalamic Research, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Charlotte E Lee
- Department of Internal Medicine, Division of Hypothalamic Research, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Syann Lee
- Department of Internal Medicine, Division of Hypothalamic Research, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Rebecca Berdeaux
- Department of Integrative Biology and Pharmacology, Center for Metabolic and Degenerative Diseases at the Brown Foundation, Institute of Molecular Medicine, McGovern Medical School at The University of Texas Health Science Center at Houston (UTHealth), Graduate Program in Biochemistry and Cell Biology, MD Anderson Cancer Center-UTHealth Graduate School of Biomedical Sciences, Houston, TX, USA
| | - Philipp E Scherer
- Touchstone Diabetes Center, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Joel K Elmquist
- Department of Internal Medicine, Division of Hypothalamic Research, University of Texas Southwestern Medical Center, Dallas, TX, USA.
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10
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Li C, Hou Y, Zhang J, Sui G, Du X, Licinio J, Wong ML, Yang Y. AGRP neurons modulate fasting-induced anxiolytic effects. Transl Psychiatry 2019; 9:111. [PMID: 30850579 PMCID: PMC6408535 DOI: 10.1038/s41398-019-0438-1] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/12/2018] [Revised: 01/26/2019] [Accepted: 02/12/2019] [Indexed: 02/06/2023] Open
Abstract
Recent studies indicate that activation of hypothalamic Agouti-related protein (Agrp) neurons can increase forage-related/repetitive behavior and decrease anxiety levels. However, the impact of physiological hunger states and food deprivation on anxiety-related behaviors have not been clarified. In the present study, we evaluated changes in anxiety levels induced by physiological hunger states and food deprivation, and identified the neuron population involved. Ad libitum fed and fasted mice were tested in the open field and elevated plus-maze behavioral tests. The DREADD approach was applied to selectively inhibit and stimulate neurons expressing Agrp in hypothalamic arcuate nucleus in Agrp-Cre transgenic mice. We found that anxiety levels were significantly reduced in the late light period when mice have increased need for food and increased Agrp neurons firing, in contrast to the levels in the early light period. Consistently, we also found that anxiety was potently reduced in 24-h fasted mice, relative to 12-h fasted mice or fed ad libitum. Mechanistically, we found that chemogenetic activation of Agrp neurons reduced anxiety in fed mice, and inactivation of Agrp neurons reduced fasting-induced anxiolytic effects. Our results suggest that anxiety levels may vary physiologically with the increasing need for food, and are influenced by acute fasting in a time-dependent manner. Agrp neurons contribute to fasting-induced anxiolytic effects, supporting the notion that Agrp neuron may serve as an entry point for the treatment of energy states-related anxiety disorders.
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Affiliation(s)
- Changhong Li
- grid.464200.4Department of Neurology, Beijing Haidian Hospital, Haidian Qu, Beijing PR China ,0000 0000 9159 4457grid.411023.5Department of Neuroscience, State University of New York Upstate Medical University, Syracuse, New York USA
| | - Yanjun Hou
- 0000000121791997grid.251993.5Department of Medicine, Albert Einstein College of Medicine, Bronx, New York USA
| | - Jia Zhang
- 0000000121791997grid.251993.5Department of Medicine, Albert Einstein College of Medicine, Bronx, New York USA ,0000 0001 2189 3846grid.207374.5Henan Provincial People’s Hospital, Zhengzhou University, Zhengzhou, Henan China
| | - Guangzhi Sui
- 0000000121791997grid.251993.5Department of Medicine, Albert Einstein College of Medicine, Bronx, New York USA
| | - Xueliang Du
- 0000000121791997grid.251993.5Department of Medicine, Albert Einstein College of Medicine, Bronx, New York USA
| | - Julio Licinio
- 0000 0000 9159 4457grid.411023.5Department of Psychiatry, State University of New York Upstate Medical University, Syracuse, New York USA
| | - Ma-Li Wong
- Department of Psychiatry, State University of New York Upstate Medical University, Syracuse, New York, USA.
| | - Yunlei Yang
- Department of Medicine, Albert Einstein College of Medicine, Bronx, New York, USA. .,Department of Neuroscience, Albert Einstein College of Medicine, Bronx, New York, USA. .,Einstein-Mount Sinai Diabetes Research Center, Albert Einstein College of Medicine, Bronx, New York, USA. .,The Fleischer Institute for Diabetes and Metabolism, Albert Einstein College of Medicine, Bronx, New York, USA. .,Department of Neuroscience, State University of New York Upstate Medical University, Syracuse, New York, USA.
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11
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Abstract
Adipose tissue possesses the remarkable capacity to control its size and function in response to a variety of internal and external cues, such as nutritional status and temperature. The regulatory circuits of fuel storage and oxidation in white adipocytes and thermogenic adipocytes (brown and beige adipocytes) play a central role in systemic energy homeostasis, whereas dysregulation of the pathways is closely associated with metabolic disorders and adipose tissue malfunction, including obesity, insulin resistance, chronic inflammation, mitochondrial dysfunction, and fibrosis. Recent studies have uncovered new regulatory elements that control the above parameters and provide new mechanistic opportunities to reprogram fat cell fate and function. In this Review, we provide an overview of the current understanding of adipocyte metabolism in physiology and disease and also discuss possible strategies to alter fuel utilization in fat cells to improve metabolic health.
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Affiliation(s)
- Edward T Chouchani
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, MA, USA.
- Department of Cell Biology, Harvard Medical School, Boston, MA, USA.
| | - Shingo Kajimura
- Department of Cell and Tissue Biology, University of California San Francisco, San Francisco, CA, USA.
- UCSF Diabetes Center, San Francisco, CA, USA.
- Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, San Francisco, CA, USA.
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12
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Silvani A, Cerri M, Zoccoli G, Swoap SJ. Is Adenosine Action Common Ground for NREM Sleep, Torpor, and Other Hypometabolic States? Physiology (Bethesda) 2019; 33:182-196. [PMID: 29616880 DOI: 10.1152/physiol.00007.2018] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
This review compares two states that lower energy expenditure: non-rapid eye movement (NREM) sleep and torpor. Knowledge on mechanisms common to these states, and particularly on the role of adenosine in NREM sleep, may ultimately open the possibility of inducing a synthetic torpor-like state in humans for medical applications and long-term space travel. To achieve this goal, it will be important, in perspective, to extend the study to other hypometabolic states, which, unlike torpor, can also be experienced by humans.
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Affiliation(s)
- Alessandro Silvani
- Department of Biomedical and Neuromotor Sciences, Alma Mater Studiorum, University of Bologna , Bologna , Italy
| | - Matteo Cerri
- Department of Biomedical and Neuromotor Sciences, Alma Mater Studiorum, University of Bologna , Bologna , Italy.,National Institute of Nuclear Physics (INFN), Section of Bologna, Bologna , Italy
| | - Giovanna Zoccoli
- Department of Biomedical and Neuromotor Sciences, Alma Mater Studiorum, University of Bologna , Bologna , Italy
| | - Steven J Swoap
- Department of Biology, Williams College , Williamstown, Massachusetts
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13
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Abstract
Interactions between the brain and distinct adipose depots have a key role in maintaining energy balance, thereby promoting survival in response to metabolic challenges such as cold exposure and starvation. Recently, there has been renewed interest in the specific central neuronal circuits that regulate adipose depots. Here, we review anatomical, genetic and pharmacological studies on the neural regulation of adipose function, including lipolysis, non-shivering thermogenesis, browning and leptin secretion. In particular, we emphasize the role of leptin-sensitive neurons and the sympathetic nervous system in modulating the activity of brown, white and beige adipose tissues. We provide an overview of advances in the understanding of the heterogeneity of the brain regulation of adipose tissues and offer a perspective on the challenges and paradoxes that the community is facing regarding the actions of leptin on this system.
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Affiliation(s)
- Alexandre Caron
- Division of Hypothalamic Research and Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Syann Lee
- Division of Hypothalamic Research and Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Joel K. Elmquist
- Division of Hypothalamic Research and Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Laurent Gautron
- Division of Hypothalamic Research and Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, TX, USA
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14
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Valencak TG, Osterrieder A, Schulz TJ. Sex matters: The effects of biological sex on adipose tissue biology and energy metabolism. Redox Biol 2017; 12:806-813. [PMID: 28441629 PMCID: PMC5406544 DOI: 10.1016/j.redox.2017.04.012] [Citation(s) in RCA: 86] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2017] [Accepted: 04/08/2017] [Indexed: 02/07/2023] Open
Abstract
Adipose tissue is a complex and multi-faceted organ. It responds dynamically to internal and external stimuli, depending on the developmental stage and activity of the organism. The most common functional subunits of adipose tissue, white and brown adipocytes, regulate and respond to endocrine processes, which then determine metabolic rate as well as adipose tissue functions. While the molecular aspects of white and brown adipose biology have become clearer in the recent past, much less is known about sex-specific differences in regulation and deposition of adipose tissue, and the specific role of the so-called pink adipocytes during lactation in females. This review summarises the current understanding of adipose tissue dynamics with a focus on sex-specific differences in adipose tissue energy metabolism and endocrine functions, focussing on mammalian model organisms as well as human-derived data. In females, pink adipocytes trans-differentiate during pregnancy from subcutaneous white adipocytes and are responsible for milk-secretion in mammary glands. Overlooking biological sex variation may ultimately hamper clinical treatments of many aspects of metabolic disorders.
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Affiliation(s)
- Teresa G Valencak
- Institute of Physiology, Pathophysiology and Biophysics, Department of Biomedical Sciences, University of Veterinary Medicine Vienna, Veterinärplatz 1, A-1210 Vienna, Austria.
| | - Anne Osterrieder
- Department of Biological and Medical Sciences, Faculty of Health and Life Sciences, Oxford Brookes University, Gipsy Lane, Headington, Oxford OX3 0BP, UK.
| | - Tim J Schulz
- Department of Adipocyte Development and Nutrition, German Institute of Human Nutrition Potsdam-Rehbrücke, 114-116, Arthur-Scheunert-Allee, 14558 Nuthetal, Germany; German Center for Diabetes Research (DZD), 85764 München-Neuherberg, Germany.
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15
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Kiehn JT, Tsang AH, Heyde I, Leinweber B, Kolbe I, Leliavski A, Oster H. Circadian Rhythms in Adipose Tissue Physiology. Compr Physiol 2017; 7:383-427. [PMID: 28333377 DOI: 10.1002/cphy.c160017] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The different types of adipose tissues fulfill a wide range of biological functions-from energy storage to hormone secretion and thermogenesis-many of which show pronounced variations over the course of the day. Such 24-h rhythms in physiology and behavior are coordinated by endogenous circadian clocks found in all tissues and cells, including adipocytes. At the molecular level, these clocks are based on interlocked transcriptional-translational feedback loops comprised of a set of clock genes/proteins. Tissue-specific clock-controlled transcriptional programs translate time-of-day information into physiologically relevant signals. In adipose tissues, clock gene control has been documented for adipocyte proliferation and differentiation, lipid metabolism as well as endocrine function and other adipose oscillations are under control of systemic signals tied to endocrine, neuronal, or behavioral rhythms. Circadian rhythm disruption, for example, by night shift work or through genetic alterations, is associated with changes in adipocyte metabolism and hormone secretion. At the same time, adipose metabolic state feeds back to central and peripheral clocks, adjusting behavioral and physiological rhythms. In this overview article, we summarize our current knowledge about the crosstalk between circadian clocks and energy metabolism with a focus on adipose physiology. © 2017 American Physiological Society. Compr Physiol 7:383-427, 2017.
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Affiliation(s)
- Jana-Thabea Kiehn
- Chronophysiology Group, Medical Department I, University of Lübeck, Lübeck, Germany
| | - Anthony H Tsang
- Chronophysiology Group, Medical Department I, University of Lübeck, Lübeck, Germany
| | - Isabel Heyde
- Chronophysiology Group, Medical Department I, University of Lübeck, Lübeck, Germany
| | - Brinja Leinweber
- Chronophysiology Group, Medical Department I, University of Lübeck, Lübeck, Germany
| | - Isa Kolbe
- Chronophysiology Group, Medical Department I, University of Lübeck, Lübeck, Germany
| | - Alexei Leliavski
- Institute of Systemic Inflammation Research, University of Lübeck, Lübeck, Germany
| | - Henrik Oster
- Chronophysiology Group, Medical Department I, University of Lübeck, Lübeck, Germany
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16
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17
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Mul Fedele ML, Galiana MD, Golombek DA, Muñoz EM, Plano SA. Alterations in Metabolism and Diurnal Rhythms following Bilateral Surgical Removal of the Superior Cervical Ganglia in Rats. Front Endocrinol (Lausanne) 2017; 8:370. [PMID: 29375476 PMCID: PMC5767240 DOI: 10.3389/fendo.2017.00370] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/07/2017] [Accepted: 12/15/2017] [Indexed: 12/21/2022] Open
Abstract
Mammalian circadian rhythms are controlled by a master pacemaker located in the suprachiasmatic nuclei (SCN), which is synchronized to the environment by photic and nonphotic stimuli. One of the main functions of the SCN is to regulate peripheral oscillators to set temporal variations in the homeostatic control of physiology and metabolism. In this sense, the SCN coordinate the activity/rest and feeding/fasting rhythms setting the timing of food intake, energy expenditure, thermogenesis, and active and basal metabolism. One of the major time cues to the periphery is the nocturnal melatonin, which is synthesized and secreted by the pineal gland. Under SCN control, arylalkylamine N-acetyltransferase (AA-NAT)-the main enzyme regulating melatonin synthesis in vertebrates-is activated at night by sympathetic innervation that includes the superior cervical ganglia (SCG). Bilateral surgical removal of the superior cervical ganglia (SCGx) is considered a reliable procedure to completely prevent the nocturnal AA-NAT activation, irreversibly suppressing melatonin rhythmicity. In the present work, we studied the effects of SCGx on rat metabolic parameters and diurnal rhythms of feeding and locomotor activity. We found a significant difference between SCGx and sham-operated rats in metabolic variables such as an increased body weight/food intake ratio, increased adipose tissue, and decreased glycemia with a normal glucose tolerance. An analysis of locomotor activity and feeding rhythms showed an increased daytime (lights on) activity (including food consumption) in the SCGx group. These alterations suggest that superior cervical ganglia-related feedback mechanisms play a role in SCN-periphery phase coordination and that SCGx is a valid model without brain-invasive surgery to explore how sympathetic innervation affects daily (24 h) patterns of activity, food consumption and, ultimately, its role in metabolism homeostasis.
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Affiliation(s)
- Malena L. Mul Fedele
- Science and Technology, Universidad Nacional de Quilmes (UNQ), Bernal, Argentina
| | - Maria D. Galiana
- Institute of Histology and Embryology of Mendoza (IHEM—CONICET), Universidad Nacional de Cuyo, Mendoza, Argentina
| | - Diego A. Golombek
- Science and Technology, Universidad Nacional de Quilmes (UNQ), Bernal, Argentina
- *Correspondence: Diego A. Golombek, ; Estela M. Muñoz, ; Santiago A. Plano,
| | - Estela M. Muñoz
- Institute of Histology and Embryology of Mendoza (IHEM—CONICET), Universidad Nacional de Cuyo, Mendoza, Argentina
- *Correspondence: Diego A. Golombek, ; Estela M. Muñoz, ; Santiago A. Plano,
| | - Santiago A. Plano
- Science and Technology, Universidad Nacional de Quilmes (UNQ), Bernal, Argentina
- Chronophysiology Laboratory, Institute for Biomedical Research (BIOMED—CONICET), UCA Pontificia Universidad Católica Argentina, Buenos Aires, Argentina
- *Correspondence: Diego A. Golombek, ; Estela M. Muñoz, ; Santiago A. Plano,
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18
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Abstract
Excess and ectopic fat accumulation in obesity is a major risk factor for developing hyperlipidemia, type 2 diabetes and cardiovascular disease. The activation of brown and/or beige adipocytes is a promising target for the treatment of metabolic disorders as the combustion of excess energy by these thermogenic adipocytes may help losing weight and improving plasma parameters including triglyceride, cholesterol and glucose levels. The regulation of heat production by thermogenic adipose tissues is based on a complex crosstalk between the autonomous nervous system, intracellular and secreted factors. This multifaceted alignment regulates thermogenic demands to environmental circumstances in dependence on available energy resources. This review summarizes the current knowledge how thermogenic tissues can be targeted to combat the burden of diseases with a special focus on lipid metabolism and diseases related to lipoprotein metabolism.
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Affiliation(s)
- Christian Schlein
- Department of Biochemistry and Molecular Cell Biology, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, 20246 Hamburg, Germany.
| | - Joerg Heeren
- Department of Biochemistry and Molecular Cell Biology, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, 20246 Hamburg, Germany.
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19
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Brianza-Padilla M, Bonilla-Jaime H, Almanza-Pérez JC, López-López AL, Sánchez-Muñoz F, Vázquez-Palacios G. Effects of different periods of paradoxical sleep deprivation and sleep recovery on lipid and glucose metabolism and appetite hormones in rats. Appl Physiol Nutr Metab 2016; 41:235-43. [DOI: 10.1139/apnm-2015-0337] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Sleep has a fundamental role in the regulation of energy balance, and it is an essential and natural process whose precise impacts on health and disease have not yet been fully elucidated. The aim of this study was to assess the consequences of different periods of paradoxical sleep deprivation (PSD) and recovery from PSD on lipid profile, oral glucose tolerance test (OGTT) results, and changes in insulin, corticosterone, ghrelin, and leptin concentrations. Three-month-old male Wistar rats weighing 250–350 g were submitted to 24, 96, or 192 h of PSD or 192 h of PSD with 480 h of recovery. The PSD was induced by the multiple platforms method. Subsequently, the animals were submitted to an OGTT. One day later, the animals were killed and the levels of triglycerides, total cholesterol, lipoproteins (low-density lipoprotein, very-low-density lipoprotein, and high-density lipoprotein), insulin, ghrelin, leptin, and corticosterone in plasma were quantified. There was a progressive decrease in body weight with increasing duration of PSD. The PSD induced basal hypoglycemia over all time periods evaluated. Evaluation of areas under the curve revealed progressive hypoglycemia only after 96 and 192 h of PSD. There was an increase in corticosterone levels after 192 h of PSD. We conclude that PSD induces alterations in metabolism that are reversed after a recovery period of 20 days.
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Affiliation(s)
| | - Herlinda Bonilla-Jaime
- Departamento de Biología de la Reproducción, Área de Biología Conductual y Reproductiva, Universidad Autónoma Metropolitana-Iztapalapa, Av. San Rafael Atlixco No. 186, Col. Vicentina, CP 09340, Mexico
| | - Julio César Almanza-Pérez
- Departamento de Ciencias de la Salud, Área de Investigación Médica, Universidad Autónoma Metropolitana-Iztapalapa, CP 09340, Mexico
| | - Ana Laura López-López
- Posgrado en Biología Experimental, Universidad Autónoma Metropolitana-Iztapalapa, CP 09340, Mexico
| | - Fausto Sánchez-Muñoz
- Departamento de Inmunología, Instituto Nacional de Cardiologia (Ignacio Chávez), Juan Badiano No. 1, Col. Sección XVI, Del. Tlalpan, CP 14080, Mexico
| | - Gonzalo Vázquez-Palacios
- Colegio de Ciencias y Humanidades, Universidad Autónoma de la Ciudad de México-San Lorenzo Tezonco, Av. Prolongación San Isidro No. 151, Col. San Lorenzo Tezonco, Del. Iztapalapa, CP 09790, Mexico
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20
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Tang L, Okamoto S, Shiuchi T, Toda C, Takagi K, Sato T, Saito K, Yokota S, Minokoshi Y. Sympathetic Nerve Activity Maintains an Anti-Inflammatory State in Adipose Tissue in Male Mice by Inhibiting TNF-α Gene Expression in Macrophages. Endocrinology 2015; 156:3680-94. [PMID: 26132918 DOI: 10.1210/en.2015-1096] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Adipose tissue macrophages (ATMs) play an important role in the inflammatory response in obese animals. How ATMs are regulated in lean animals has remained elusive, however. We now show that the sympathetic nervous system (SNS) is necessary to maintain the abundance of the mRNA for the proinflammatory cytokine TNF-α at a low level in ATMs of lean mice. Intracerebroventricular injection of agouti-related neuropeptide increased the amount of TNF-α mRNA in epididymal (epi) white adipose tissue (WAT), but not in interscapular brown adipose tissue (BAT), through inhibition of sympathetic nerve activity in epiWAT. The surgical denervation and β-adrenergic antagonist propranolol up-regulated TNF-α mRNA in both epiWAT and BAT in vivo. Signaling by the β2-adrenergic receptor (AR) and protein kinase A down-regulated TNF-α mRNA in epiWAT explants and suppressed lipopolysaccharide-induced up-regulation of TNF-α mRNA in the stromal vascular fraction of this tissue. β-AR-deficient (β-less) mice manifested an increased plasma TNF-α concentration and increased TNF-α mRNA abundance in epiWAT and BAT. TNF-α mRNA abundance was greater in ATMs (CD11b(+) cells of the stromal vascular fraction) from epiWAT or BAT of wild-type mice than in corresponding CD11b(-) cells, and β2-AR mRNA abundance was greater in ATMs than in CD11b(-) cells of epiWAT. Our results show that the SNS and β2-AR-protein kinase A pathway maintain an anti-inflammatory state in ATMs of lean mice in vivo, and that the brain melanocortin pathway plays a role in maintaining this state in WAT of lean mice via the SNS.
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MESH Headings
- Adipose Tissue, Brown/drug effects
- Adipose Tissue, Brown/innervation
- Adipose Tissue, Brown/metabolism
- Adipose Tissue, White/drug effects
- Adipose Tissue, White/innervation
- Adipose Tissue, White/metabolism
- Adrenergic beta-Antagonists/pharmacology
- Agouti-Related Protein/administration & dosage
- Animals
- Cell Line
- Epididymis/drug effects
- Epididymis/metabolism
- Gene Expression/drug effects
- Immunoblotting
- Inflammation Mediators/metabolism
- Injections, Intraventricular
- Macrophages/metabolism
- Male
- Mice, Inbred C57BL
- Mice, Knockout
- Peptide Fragments/administration & dosage
- Propranolol/pharmacology
- Receptors, Adrenergic, beta/genetics
- Receptors, Adrenergic, beta/metabolism
- Reverse Transcriptase Polymerase Chain Reaction
- Sympathectomy
- Sympathetic Nervous System/metabolism
- Tumor Necrosis Factor-alpha/genetics
- Tumor Necrosis Factor-alpha/metabolism
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Affiliation(s)
- Lijun Tang
- Division of Endocrinology and Metabolism (L.T., S.O., K.T., T.Sa., K.S., S.Y., Y.M.), Department of Developmental Physiology, National Institute for Physiological Sciences, Okazaki, Aichi 444-8585, Japan; Department of Physiological Sciences (S.O., T.Sa., Y.M.), Sokendai (The Graduate University for Advanced Studies), Hayama, Kanagawa 240-0193, Japan; Department of Integrative Physiology (T.Sh.), Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima City, Tokushima 770-8503, Japan; and Section of Comparative Medicine (C.T.), Yale University School of Medicine, New Haven, Connecticut 06520-8016
| | - Shiki Okamoto
- Division of Endocrinology and Metabolism (L.T., S.O., K.T., T.Sa., K.S., S.Y., Y.M.), Department of Developmental Physiology, National Institute for Physiological Sciences, Okazaki, Aichi 444-8585, Japan; Department of Physiological Sciences (S.O., T.Sa., Y.M.), Sokendai (The Graduate University for Advanced Studies), Hayama, Kanagawa 240-0193, Japan; Department of Integrative Physiology (T.Sh.), Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima City, Tokushima 770-8503, Japan; and Section of Comparative Medicine (C.T.), Yale University School of Medicine, New Haven, Connecticut 06520-8016
| | - Tetsuya Shiuchi
- Division of Endocrinology and Metabolism (L.T., S.O., K.T., T.Sa., K.S., S.Y., Y.M.), Department of Developmental Physiology, National Institute for Physiological Sciences, Okazaki, Aichi 444-8585, Japan; Department of Physiological Sciences (S.O., T.Sa., Y.M.), Sokendai (The Graduate University for Advanced Studies), Hayama, Kanagawa 240-0193, Japan; Department of Integrative Physiology (T.Sh.), Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima City, Tokushima 770-8503, Japan; and Section of Comparative Medicine (C.T.), Yale University School of Medicine, New Haven, Connecticut 06520-8016
| | - Chitoku Toda
- Division of Endocrinology and Metabolism (L.T., S.O., K.T., T.Sa., K.S., S.Y., Y.M.), Department of Developmental Physiology, National Institute for Physiological Sciences, Okazaki, Aichi 444-8585, Japan; Department of Physiological Sciences (S.O., T.Sa., Y.M.), Sokendai (The Graduate University for Advanced Studies), Hayama, Kanagawa 240-0193, Japan; Department of Integrative Physiology (T.Sh.), Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima City, Tokushima 770-8503, Japan; and Section of Comparative Medicine (C.T.), Yale University School of Medicine, New Haven, Connecticut 06520-8016
| | - Kazuyo Takagi
- Division of Endocrinology and Metabolism (L.T., S.O., K.T., T.Sa., K.S., S.Y., Y.M.), Department of Developmental Physiology, National Institute for Physiological Sciences, Okazaki, Aichi 444-8585, Japan; Department of Physiological Sciences (S.O., T.Sa., Y.M.), Sokendai (The Graduate University for Advanced Studies), Hayama, Kanagawa 240-0193, Japan; Department of Integrative Physiology (T.Sh.), Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima City, Tokushima 770-8503, Japan; and Section of Comparative Medicine (C.T.), Yale University School of Medicine, New Haven, Connecticut 06520-8016
| | - Tatsuya Sato
- Division of Endocrinology and Metabolism (L.T., S.O., K.T., T.Sa., K.S., S.Y., Y.M.), Department of Developmental Physiology, National Institute for Physiological Sciences, Okazaki, Aichi 444-8585, Japan; Department of Physiological Sciences (S.O., T.Sa., Y.M.), Sokendai (The Graduate University for Advanced Studies), Hayama, Kanagawa 240-0193, Japan; Department of Integrative Physiology (T.Sh.), Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima City, Tokushima 770-8503, Japan; and Section of Comparative Medicine (C.T.), Yale University School of Medicine, New Haven, Connecticut 06520-8016
| | - Kumiko Saito
- Division of Endocrinology and Metabolism (L.T., S.O., K.T., T.Sa., K.S., S.Y., Y.M.), Department of Developmental Physiology, National Institute for Physiological Sciences, Okazaki, Aichi 444-8585, Japan; Department of Physiological Sciences (S.O., T.Sa., Y.M.), Sokendai (The Graduate University for Advanced Studies), Hayama, Kanagawa 240-0193, Japan; Department of Integrative Physiology (T.Sh.), Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima City, Tokushima 770-8503, Japan; and Section of Comparative Medicine (C.T.), Yale University School of Medicine, New Haven, Connecticut 06520-8016
| | - Shigefumi Yokota
- Division of Endocrinology and Metabolism (L.T., S.O., K.T., T.Sa., K.S., S.Y., Y.M.), Department of Developmental Physiology, National Institute for Physiological Sciences, Okazaki, Aichi 444-8585, Japan; Department of Physiological Sciences (S.O., T.Sa., Y.M.), Sokendai (The Graduate University for Advanced Studies), Hayama, Kanagawa 240-0193, Japan; Department of Integrative Physiology (T.Sh.), Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima City, Tokushima 770-8503, Japan; and Section of Comparative Medicine (C.T.), Yale University School of Medicine, New Haven, Connecticut 06520-8016
| | - Yasuhiko Minokoshi
- Division of Endocrinology and Metabolism (L.T., S.O., K.T., T.Sa., K.S., S.Y., Y.M.), Department of Developmental Physiology, National Institute for Physiological Sciences, Okazaki, Aichi 444-8585, Japan; Department of Physiological Sciences (S.O., T.Sa., Y.M.), Sokendai (The Graduate University for Advanced Studies), Hayama, Kanagawa 240-0193, Japan; Department of Integrative Physiology (T.Sh.), Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima City, Tokushima 770-8503, Japan; and Section of Comparative Medicine (C.T.), Yale University School of Medicine, New Haven, Connecticut 06520-8016
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21
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Meng X, Zheng R, Zhang Y, Qiao M, Liu L, Jing P, Wang L, Liu J, Gao Y. An activated sympathetic nervous system affects white adipocyte differentiation and lipolysis in a rat model of Parkinson's disease. J Neurosci Res 2014; 93:350-60. [PMID: 25257318 DOI: 10.1002/jnr.23488] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2014] [Revised: 08/13/2014] [Accepted: 09/04/2014] [Indexed: 01/25/2023]
Abstract
Weight loss is an important nonmotor symptom associated with Parkinson's disease (PD). However, the cellular factors responsible for PD-induced weight loss remain unclear. Because the sympathetic nervous system plays an important role in lipid metabolism and fat cell differentiation, this study investigates whether PD-induced changes to this system are associated with weight loss in a rat model of PD. Body weight and food intake were measured in control and PD-model rats. After 10 weeks, retroperitoneal white adipose tissues (RWAT) were removed and weighed. Markers of the sympathetic nervous system were measured in the brainstem dorsal medulla and RWAT. Free fat acids (FFA), triglycerides (TG), adipocyte differentiation-related genes, and lipolysis-related molecules in the RWAT and serum were analyzed. Differences in body weight and food intake were insignificant in PD-model rats and control rats; however, relative RWAT weight and adipocyte surface area were significantly reduced in the PD group. Changes in markers of the sympathetic nervous system were observed in the brainstem dorsal medulla and RWAT of PD rats. Decreased mRNA expression levels of genes involved in adipocyte differentiation, decreased TG levels in RWAT, increased FFA in RWAT, and increased lipolysis-related molecules in RWAT and serum FFA were observed in PD rats. This study demonstrates that degenerated dopaminergic neurons in the nigrostriatal system correlate with increases in sympathetic nervous system function, resulting in lipolysis and inhibition of fat cell differentiation. These factors ultimately result in the decrease of RWAT in PD-model rats.
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Affiliation(s)
- XiangZhi Meng
- Department of Human Anatomy, School of Basic Medical Sciences, Capital Medical University, Beijing, China
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22
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Abstract
Fasting of mice is a common procedure performed in association with many different types of experiments mainly in order to reduce variability in investigatory parameters or to facilitate surgical procedures. However, the effects of fasting not directly related to the investigatory parameters are often ignored. The aim of this review is to present and summarize knowledge about the effects of fasting of mice to facilitate optimization of the fasting procedure for any given study and thereby maximize the scientific outcome and minimize the discomfort for the mice and hence ensure high animal welfare. The results are presented from a number of experimental studies, providing evidence for fasting-induced changes in hormone balance, body weight, metabolism, hepatic enzymes, cardiovascular parameters, body temperature and toxicological responses. A description of relevant normal behaviour and standard physiological parameters is given, concluding that mice are primarily nocturnal and consume two-thirds of their total food intake during the night. It is argued that overnight fasting of mice is not comparable with overnight fasting of humans because the mouse has a nocturnal circadian rhythm and a higher metabolic rate. It is suggested that because many physiological parameters are regulated by circadian rhythms, fasting initiated at different points in the circadian rhythm has different impacts and produces different results.
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Affiliation(s)
- T L Jensen
- Novo Nordisk, Animal Unit, Maaloev, Denmark
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23
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Yonejima Y, Ushida K, Mori Y. Effect of Lactic Acid Bacteria on Lipid Metabolism and Fat Synthesis in Mice Fed a High-fat Diet. BIOSCIENCE OF MICROBIOTA FOOD AND HEALTH 2013; 32:51-8. [PMID: 24936362 PMCID: PMC4034319 DOI: 10.12938/bmfh.32.51] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/07/2012] [Accepted: 01/01/2013] [Indexed: 01/30/2023]
Abstract
Visceral fat accumulation is a major risk factor for the development of obesity-related
diseases, including diabetes, hyperlipidemia, hypertension, and arteriosclerosis.
Stimulation of lipolytic activity in adipose tissue or inhibition of fat synthesis is one
way to prevent these serious diseases. Lactic acid bacteria have an anti-obesity effect,
but the mechanisms are unclear. Therefore, we evaluated the effect of the administration
of lactic acid bacteria (Lactobacillus gasseri NT) on lipid metabolism
and fat synthesis in a mouse high-fat-diet model, focusing on visceral fat. Balb/c mice
were fed a 45 kcal% fat diet for 13 weeks with and without a freeze-dried preparation of
L. gasseri NT (109 CFU/g). An ex vivo
glycerol assay with periovarian fat revealed that L. gasseri NT did not
stimulate lipolytic activity. However, L. gasseri NT decreased the mRNA
expression of sterol regulatory element-binding protein (SREBP) and its target gene fatty
acid synthase (FAS) in the liver and decreased free fatty acid (FFA) in the blood. In
conclusion, these findings indicated that administration of L. gasseri NT
did not enhance lipid mobilization but can reduce fat synthesis, suggesting its potential
for improving obesity-related diseases.
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Affiliation(s)
- Yasunori Yonejima
- Graduate School of Life and Environmental Sciences, Kyoto Prefectural University, Shimogamo, Kyoto 606-8522, Japan ; Research and Development Department, Nitto Pharmaceutical Industries, Ltd., 35-3 Minamibiraki, Kamiueno-cho, Muko 617-0006, Japan
| | - Kazunari Ushida
- Graduate School of Life and Environmental Sciences, Kyoto Prefectural University, Shimogamo, Kyoto 606-8522, Japan
| | - Yoshiro Mori
- Graduate School of Life and Environmental Sciences, Kyoto Prefectural University, Shimogamo, Kyoto 606-8522, Japan
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Martens K, Bottelbergs A, Peeters A, Jacobs F, Espeel M, Carmeliet P, Van Veldhoven PP, Baes M. Peroxisome deficient aP2-Pex5 knockout mice display impaired white adipocyte and muscle function concomitant with reduced adrenergic tone. Mol Genet Metab 2012; 107:735-47. [PMID: 23141464 DOI: 10.1016/j.ymgme.2012.10.015] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/11/2012] [Revised: 10/16/2012] [Accepted: 10/16/2012] [Indexed: 12/21/2022]
Abstract
Peroxisomes are essential for intermediary lipid metabolism, but the role of these organelles has been primarily studied in the liver. We recently generated aP2-Pex5 conditional knockout mice that due to the nonselectivity of the aP2 promoter, not only had dysfunctional peroxisomes in the adipose tissue but also in the central and peripheral nervous system, besides some other tissues. Peroxisomes were however intact in the liver, heart, pancreas and muscle. Surprisingly, these mice not only showed dysfunctional white adipose tissue with increased fat mass and reduced lipolysis but also the skeletal muscle was affected including impaired shivering thermogenesis, reduced motor performance and increased insulin resistance. Non-shivering thermogenesis by brown adipose tissue was not altered. Strongly reduced levels of plasma adrenaline and to a lesser extent noradrenaline, impaired expression of catecholamine synthesizing enzymes in the adrenal medulla and reversal of all pathologies after administration of the β-agonist isoproterenol indicated that β-adrenergic signaling was reduced. Based on normal white adipose and muscle function in Nestin-Pex5 and Wnt-Pex5 knockout mice respectively, it is unlikely that peroxisome absence from the central and peripheral nervous system caused the phenotype. We conclude that peroxisomal metabolism is necessary to maintain the adrenergic tone in mice, which in turn determines metabolic homeostasis.
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Affiliation(s)
- Katrin Martens
- Laboratory of Cell Metabolism, Department of Pharmaceutical Sciences, KU Leuven, Leuven, Belgium
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25
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Kim JH, Park Y, Kim D, Good DJ, Park Y. Dietary conjugated nonadecadienoic acid prevents adult-onset obesity in nescient basic helix-loop-helix 2 knockout mice. J Nutr Biochem 2012; 24:556-66. [PMID: 22819563 DOI: 10.1016/j.jnutbio.2012.02.005] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2011] [Revised: 02/03/2012] [Accepted: 02/10/2012] [Indexed: 10/28/2022]
Abstract
Conjugated linoleic acid (CLA) has been extensively studied during the last two decades with regard to its effects on controlling body composition. As a cognate to CLA, conjugated nonadecadienoic acid (CNA) has been previously reported to reduce body fat more effectively than CLA. However, it is not known whether CNA supplementation can influence adult-onset obesity. Thus, the purpose of this study was to evaluate the effects of dietary CNA on the prevention of adult-onset inactivity-induced obesity using nescient basic helix-loop-helix 2 knockout (N2KO) mice. CNA supplementation at 0.1 w/w% level starting in the preobese state significantly prevented the reduction of voluntary movement and the increase in weight gain in N2KO mice during the experimental period compared to wild-type animals. In both wild-type and N2KO mice, respiratory exchange ratio was significantly reduced by CNA treatment during light and dark cycles, and dietary CNA significantly increased energy expenditure in N2KO mice. Selected gene expression profiles in white adipose tissue, muscle or liver showed a beneficial action of CNA on lipid metabolism and energy expenditure. These findings suggest that CNA could prevent adult-onset obesity by enhancing voluntary activity and energy expenditure in N2KO mice.
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Affiliation(s)
- Jun Ho Kim
- Department of Food Science, University of Massachusetts, Amherst, MA 01003, USA
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26
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A low-protein, high-carbohydrate diet increases fatty acid uptake and reduces norepinephrine-induced lipolysis in rat retroperitoneal white adipose tissue. Lipids 2012; 47:279-89. [PMID: 22228227 DOI: 10.1007/s11745-011-3648-8] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2011] [Accepted: 12/08/2011] [Indexed: 10/14/2022]
Abstract
A low-protein, high-carbohydrate (LPHC) diet for 15 days increased the lipid content in the carcass and adipose tissues of rats. The aim of this work was to investigate the mechanisms of this lipid increase in the retroperitoneal white adipose tissue (RWAT) of these animals. The LPHC diet induced an approximately two- and tenfold increase in serum corticosterone and TNF-α, respectively. The rate of de novo fatty acid (FA) synthesis in vivo was reduced (50%) in LPHC rats, and the lipoprotein lipase activity increased (100%). In addition, glycerokinase activity increased (60%), and the phosphoenolpyruvate carboxykinase content decreased (27%). Basal [U-¹⁴C]-glucose incorporation into glycerol-triacylglycerol did not differ between the groups; however, in the presence of insulin, [U-¹⁴C]-glucose incorporation increased by 124% in adipocytes from only control rats. The reductions in IRS1 and AKT content as well as AKT phosphorylation in the RWAT from LPHC rats and the absence of an insulin response suggest that these adipocytes have reduced insulin sensitivity. The increase in NE turnover by 45% and the lack of a lipolytic response to NE in adipocytes from LPHC rats imply catecholamine resistance. The data reveal that the increase in fat storage in the RWAT of LPHC rats results from an increase in FA uptake from circulating lipoproteins and glycerol phosphorylation, which is accompanied by an impaired lipolysis that is activated by NE.
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27
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Chaudhuri A, Borade NG, Tirumalai J, Saldanha D, Ghosh B, Srivastava K. A study of autonomic functions and obesity in postmenopausal women. Ind Psychiatry J 2012; 21:39-43. [PMID: 23766576 PMCID: PMC3678176 DOI: 10.4103/0972-6748.110949] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND Easy accessibility to Medicare and better living conditions has increased life expectancy in recent years. There are over 60 million postmenopausal women above 55 years in India. Obesity, physical inactivity, and altered estrogen metabolism play an integrated role in contributing to the disease risk profile of postmenopausal women. These same risk factors also affect modulation of the autonomic nervous system. A study was undertaken to test the hypothesis whether there is indeed an alteration in autonomic functions in obese postmenopausal women. MATERIALS AND METHODS 60 postmenopausal women without any gross systemic disease whose body mass index and waist/hip ratio were recorded. Subjects were divided into two groups of 36 Non-Obese and 24 Obese. The two groups were well matched for age and menopausal duration. The physical as well as physiological parameters like valsalva ratio, heart rate variation with deep breath test, heart rate response to postural change (30:15 R-R interval ratio), orthostatic tolerance test, and isometric handgrip test were recorded. RESULTS Results of valsalva ratio, deep breath test, and 30:15 R-R interval ratios and isometric handgrip test were significantly decreased and orthostatic tolerance values were significantly increased in Obese subjects. CONCLUSION Findings show decreased sympathovagal activity with obesity in postmenopausal women.
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Affiliation(s)
- Arunima Chaudhuri
- Department of Physiology, Dr. D.Y. Patil Medical College, Kolkata, West Bengal, India
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28
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Caimari A, Oliver P, Palou A. Adipose triglyceride lipase expression and fasting regulation are differently affected by cold exposure in adipose tissues of lean and obese Zucker rats. J Nutr Biochem 2011; 23:1041-50. [PMID: 21944063 DOI: 10.1016/j.jnutbio.2011.05.008] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2010] [Revised: 05/09/2011] [Accepted: 05/16/2011] [Indexed: 01/04/2023]
Abstract
Adipose triglyceride lipase (ATGL) hydrolyzes triacylglycerols to diacylglycerols in the first step of lipolysis, providing substrates for hormone-sensitive lipase (HSL). Here we studied whether ATGL messenger RNA (mRNA) and protein levels were affected by 24-h cold exposure in different white adipose tissue depots and in interscapular brown adipose tissue of lean and obese Zucker rats submitted to feeding and 14-h fasting conditions. HSL mRNA expression was also studied in selected depots. In both lean and obese rats, as a general trend, cold exposure increased ATGL mRNA and protein levels in the different adipose depots, except in the brown adipose tissue of lean animals, where a decrease was observed. In lean rats, cold exposure strongly improved fasting up-regulation of ATGL expression in all the adipose depots. Moreover, in response to fasting, in cold-exposed lean rats, there was a stronger positive correlation between circulating nonesterified fatty acids (NEFA) and ATGL mRNA levels in the adipose depots and a higher percentage increase of circulating NEFA in comparison with control animals not exposed to cold. In obese rats, fasting-induced up-regulation of ATGL was impaired and was not improved by cold. The effects of obesity and cold exposure on HSL mRNA expression were similar to those observed for ATGL, suggesting common regulatory mechanisms for both proteins. Thus, cold exposure increases ATGL expression and improves its fasting-up-regulation in adipose tissue of lean rats. In obese rats, cold exposure also increases ATGL expression but fails to improve its regulation by fasting, which could contribute to the increased difficulty for mobilizing lipids in these animals.
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Affiliation(s)
- Antoni Caimari
- Laboratory of Molecular Biology, Nutrition and Biotechnology, Universitat de les Illes Balears, and CIBER de Fisiopatología de la Obesidad y Nutrición, Palma de Mallorca, Spain
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29
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Cold exposure down-regulates adiponutrin/PNPLA3 mRNA expression and affects its nutritional regulation in adipose tissues of lean and obese Zucker rats. Br J Nutr 2011; 107:1283-95. [PMID: 21914237 DOI: 10.1017/s000711451100434x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Adiponutrin/PNPLA3 is a protein highly produced in adipose tissue whose expression is under tight nutritional regulation. It possesses lipogenic/lipolytic capacity and, although adiponutrin polymorphisms are related to obesity, its physiological role is not clear. To help clarify its role, we studied the effect of acute cold exposure on adiponutrin mRNA expression in different adipose tissues of lean/obese Zucker rats subjected to feeding/fasting/refeeding. The effect of cold on the expression of key lipogenic enzymes and on uncoupling protein-1 (UCP1) was evaluated in selected adipose depots. Adiponutrin mRNA levels were also determined in the adipose tissue of isoprenaline-treated rats and in cultured adipocytes treated with noradrenaline, isoprenaline and a selective β3-adrenoceptor (AR) agonist. Adiponutrin expression was strongly down-regulated by cold in the different adipose depots in lean animals, while this down-regulation was impaired in obese rats. Adiponutrin pattern of expression in response to cold correlated positively with that of the lipogenic enzymes and negatively with UCP1 expression. Acute intraperitoneal administration of isoprenaline also produced a decrease in adiponutrin expression in adipose tissue. In vitro data suggest that adiponutrin's inhibitory effect could be mediated, at least in part, by the sympathetic system via β1/β2-AR. In addition, improvement in metabolic parameters related to obesity in cold-exposed animals was related to an improvement in adiponutrin nutritional regulation. Thus, cold inhibition of adiponutrin expression in adipose tissue (which correlates with the response of lipogenic enzymes) supports a physiological role for this protein in lipogenesis. Moreover, alterations in adiponutrin expression and regulation in adipose tissue are related to obesity.
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30
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Demas GE. In vivo but not in vitro leptin enhances lymphocyte proliferation in Siberian hamsters (Phodopus sungorus). Gen Comp Endocrinol 2010; 166:314-9. [PMID: 19896948 DOI: 10.1016/j.ygcen.2009.10.011] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/10/2009] [Revised: 10/06/2009] [Accepted: 10/28/2009] [Indexed: 11/16/2022]
Abstract
Mounting an immune response requires a relatively substantial investment of energy and marked reductions in energy availability can suppress immune function and presumably increase disease susceptibility. We have previously demonstrated that a moderate reduction in energy stores by partial surgical lipectomy impairs humoral immunity of Siberian hamsters (Phodopus sungorus) and is mediated, in part, by changes in the adipose tissue hormone leptin. The goals of the present study were to assess the role of leptin in cell-mediated immunity and to determine if the potential effects of leptin on immunity are via the direct actions of this hormone on lymphocytes, or indirect, via the sympathetic nervous system (SNS). In Experiment 1, hamsters received osmotic minipumps containing either murine leptin (0.5 microl/h) or vehicle alone for 10 days and splenocyte proliferation in response to the T-cell mitogen Concanavalin A (Con A) was determined. In Experiment 2, Con A-induced splenocyte proliferation was tested in the presence or absence of leptin in vitro. In Experiment 3, exogenous leptin was administered to intact or sympathetically denervated hamsters. Hamsters treated with in vivo leptin displayed increased splenocyte proliferation compared with control hamsters receiving vehicle. In contrast, in vitro leptin had no effect on splenocyte proliferation. Sympathetic denervation attenuated, but did not block, leptin-induced increases in immunity. Taken together, these results are consistent with the idea that leptin can enhance cell-mediated immunity; the SNS appears to contribute, least in part, to leptin-induced increases in immunity. Importantly, these findings confirm previous studies that leptin serves as an important endocrine link between energy balance and immunity.
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Affiliation(s)
- Gregory E Demas
- Department of Biology, Program in Neuroscience and the Center for the Integrative Study of Animal Behavior, Indiana University, 1001 E. 3rd Street, Bloomington, IN 47405, USA.
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31
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Chronic intracerebroventricular injection of TLQP-21 prevents high fat diet induced weight gain in fast weight-gaining mice. GENES AND NUTRITION 2009; 4:49-57. [PMID: 19247701 DOI: 10.1007/s12263-009-0110-0] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Received: 10/29/2008] [Accepted: 01/07/2009] [Indexed: 01/31/2023]
Abstract
The vgf gene regulates energy homeostasis and the VGF-derived peptide TLQP-21 centrally exerts catabolic effects in mice and hamsters. Here, we investigate the effect of chronic intracerebroventricular (icv) injection of TLQP-21 in mice fed high fat diet (HFD). Fast weight-gaining mice injected with the peptide or cerebrospinal fluid were selected for physiological, endocrine, and molecular analysis. TLQP-21 selectively inhibited the increase in body weight and epididymal white adipose tissue (eWAT) weight induced by HFD in control animals despite both groups having a similar degree of hyperphagia. TLQP-21 normalized the increase in leptin and decrease in ghrelin while increasing epinephrine and epinephrine/norepinephrine ratio when compared to values in controls. Finally, HFD-TLQP-21 mice showed a selective increase of eWAT beta3-adrenergic receptor mRNA. Peroxisome-proliferator-activated-receptor-delta and hormone-sensing-lipase mRNA were also upregulated. In conclusion, chronic icv infusion of TLQP-21 prevented the early phase of diet-induced obesity despite overfeeding. These effects were paralleled by activation of catabolic pathways within the eWAT. Our results further support a role for TLQP-21 as a catabolic neuropeptide.
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Swoap SJ, Weinshenker D. Norepinephrine controls both torpor initiation and emergence via distinct mechanisms in the mouse. PLoS One 2008; 3:e4038. [PMID: 19107190 PMCID: PMC2602851 DOI: 10.1371/journal.pone.0004038] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2008] [Accepted: 11/27/2008] [Indexed: 12/04/2022] Open
Abstract
Some mammals, including laboratory mice, enter torpor in response to food deprivation, and leptin can attenuate these bouts of torpor. We previously showed that dopamine β-hydroxylase knockout (Dbh −/−) mice, which lack norepinephrine (NE), do not reduce circulating leptin upon fasting nor do they enter torpor. To test whether the onset of torpor in mice during a fast requires a NE-mediated reduction in circulating leptin, double mutant mice deficient in both leptin (ob/ob) and DBH (DBL MUT) were generated. Upon fasting, control and ob/ob mice entered torpor as assessed by telemetric core Tb acquisition. While fasting failed to induce torpor in Dbh −/− mice, leptin deficiency bypassed the requirement for NE, as DBL MUT mice readily entered torpor upon fasting. These data indicate that sympathetic activation of white fat and suppression of leptin is required for the onset of torpor in the mouse. Emergence from torpor was severely retarded in DBL MUT mice, revealing a novel, leptin-independent role for NE in torpor recovery. This phenotype was mimicked by administration of a β3 adrenergic receptor antagonist to control mice during a torpor bout. Hence, NE signaling via β3 adrenergic receptors presumably in brown fat is the first neurotransmitter-receptor system identified that is required for normal recovery from torpor.
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Affiliation(s)
- Steven J Swoap
- Department of Biology, Williams College, Williamstown, Massachusetts, United States of America.
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Swoap SJ. The pharmacology and molecular mechanisms underlying temperature regulation and torpor. Biochem Pharmacol 2008; 76:817-24. [PMID: 18644349 DOI: 10.1016/j.bcp.2008.06.017] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2008] [Revised: 06/02/2008] [Accepted: 06/02/2008] [Indexed: 01/08/2023]
Abstract
The ability to enter a hypometabolic state upon restriction of caloric intake is pivotal for animal survival: balancing the energy budget in endotherms can be a real struggle when food is not available and/or the demand for heat production to maintain homeothermy becomes excessive. Bouts of torpor, characterized by metabolic rates well below a basal metabolic rate and core body temperatures that may be just a few degrees above the ambient temperature, are utilized among many organisms across the animal kingdom, including those that could be described as typical laboratory animals, like the mouse or hamster. Daily heterotherms, which are the focus of this commentary, enter shallow torpor bouts and do so usually under acute food shortage conditions and a relatively cool environment. Due to their small size, the body temperature of these animals is very responsive to food deprivation, pharmacological inhibition of metabolic rate, and cardiovascular depressants. This commentary examines recent developments concerning the neuroendocrine mechanisms in place that may mediate fasting-induced torpor in daily heterotherms. Further this commentary highlights pharmacological induction of hypothermia in small mammals.
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Affiliation(s)
- Steven J Swoap
- Department of Biology, Williams College, Williamstown, MA 01267, USA.
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Nakamura J. Protein kinase CβI interacts with the β1-adrenergic signaling pathway to attenuate lipolysis in rat adipocytes. Biochim Biophys Acta Mol Cell Biol Lipids 2008; 1781:277-81. [DOI: 10.1016/j.bbalip.2008.03.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2007] [Revised: 03/03/2008] [Accepted: 03/21/2008] [Indexed: 01/28/2023]
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Bartolomucci A, Possenti R, Levi A, Pavone F, Moles A. The role of the vgf gene and VGF-derived peptides in nutrition and metabolism. GENES & NUTRITION 2007; 2:169-80. [PMID: 18850173 PMCID: PMC2474945 DOI: 10.1007/s12263-007-0047-0] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2006] [Accepted: 10/24/2006] [Indexed: 12/01/2022]
Abstract
Energy homeostasis is a complex physiological function coordinated at multiple levels. The issue of genetic regulation of nutrition and metabolism is attracting increasing interest and new energy homeostasis-regulatory genes are continuously identified. Among these genes, vgf is gaining increasing interest following two observations: (1) VGF-/- mice have a lean and hypermetabolic phenotype; (2) the first VGF-derived peptide involved in energy homeostasis, named TLQP-21, has been identified. The aim of this review will be to discuss the role of the vgf gene and VGF derived peptides in metabolic and nutritional functions. In particular we will: (1) provide a brief overview on the central systems regulating energy homeostasis and nutrition particularly focusing on the melanocortin system; (2) introduce the structure and molecular characteristic of vgf; (3) describe the phenotype of VGF deficient mice; (4) present recent data on the metabolic role of VGF-derived peptides, particularly focusing on one peptide named TLQP-21.
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Affiliation(s)
- Alessandro Bartolomucci
- Institute of Neuroscience, CNR, Via del Fosso di Fiorano 64, 00143 Rome, Italy
- Dipartimento di Biologia Evolutiva e Funzionale, Università di Parma, V.le G.P. Usberti 11A, 43100 Parma, Italy
| | - Roberta Possenti
- Department of Neuroscience, University of Roma II-Tor Vergata, Rome, Italy
- Institute of Neurobiology and Molecular Medicine, CNR, Rome, Italy
| | - Andrea Levi
- Institute of Neurobiology and Molecular Medicine, CNR, Rome, Italy
| | - Flaminia Pavone
- Institute of Neuroscience, CNR, Via del Fosso di Fiorano 64, 00143 Rome, Italy
| | - Anna Moles
- Institute of Neuroscience, CNR, Via del Fosso di Fiorano 64, 00143 Rome, Italy
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36
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Nakamura J. Protein kinase C-dependent antilipolysis by insulin in rat adipocytes. Biochim Biophys Acta Mol Cell Biol Lipids 2007; 1771:1195-201. [PMID: 17689141 DOI: 10.1016/j.bbalip.2007.06.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2007] [Revised: 05/19/2007] [Accepted: 06/27/2007] [Indexed: 01/19/2023]
Abstract
Recently, we have shown that protein kinase C (PKC) activated by phorbol 12-myristate 13-acetate (PMA) attenuates the beta1-adrenergic receptor (beta1-AR)-mediated lipolysis in rat adipocytes. Stimulation of cells by insulin, angiotensin II, and alpha1-AR agonist is known to cause activation of PKC. In this study, we found that lipolysis induced by the beta1-AR agonist dobutamine is decreased and is no longer inhibited by PMA in adipocytes that have been treated with 20 nM insulin for 30 min followed by washing out insulin. Such effects on lipolysis were not found after pretreatment with angiotensin II and alpha1-AR agonists. The rate of lipolysis in the insulin-treated cells was normalized by the PKCalpha- and beta-specific inhibitor Gö 6976 and PKCbeta-specific inhibitor LY 333531. In the insulin-treated cells, wortmannin increased lipolysis and recovered the lipolysis-attenuating effect of PMA. Western blot analysis revealed that insulin slightly increases membrane-bound PKCalpha, betaI, and delta, and wortmannin decreases PKCbetaI, betaII, and delta in the membrane fraction. These results indicate that stimulation of insulin receptor induces a sustained activation of PKC-dependent antilipolysis in rat adipocytes.
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Affiliation(s)
- Jiro Nakamura
- Graduate School of Comprehensive Human Sciences, University of Tsukuba, Tsukuba-shi, Ibaraki-ken, 305-8575, Japan.
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37
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Benatti FB, Lancha Junior AH. Leptina e exercício físico aeróbio: implicações da adiposidade corporal e insulina. REV BRAS MED ESPORTE 2007. [DOI: 10.1590/s1517-86922007000400011] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Atualmente, a obesidade pode ser classificada como uma pandemia e suas conseqüências vão desde o diabetes mellitus até a doença cardíaca. Tanto fatores genéticos como ambientais contribuem para isso, porém, em humanos, o componente genético ainda é pouco definido. Com a clonagem do gene ob de ratos e do seu receptor, foi descoberta a leptina, o "hormônio da saciedade". A leptina é secretada, principalmente, pelo tecido adiposo e reflete a quantidade de gordura depositada no tecido adiposo de um indivíduo. Entretanto, diversos fatores influenciam sua expressão e síntese, tais como jejum, atividade simpática, exercício físico e alterações no balanço energético. Os efeitos da atividade física aeróbia sobre esse hormônio ainda não estão muito claros, visto que existem muitas contradições na literatura sobre sua possível ação na regulação da leptina. Estudos transversais sugerem que as concentrações plasmáticas de leptina não são alteradas após uma sessão de exercício aeróbio. Entretanto, se o esforço físico for extremo, como em uma ultramaratona, na qual há um balanço energético negativo, induzido pela atividade física extenuante, ocorre diminuição dessas concentrações. Além disso, exercícios de longa duração (> 60 min) parecem estar associados à diminuição tardia das concentrações de leptina, aproximadamente 48h após a atividade, provavelmente em função de um possível desequilíbrio energético. Em relação aos estudos longitudinais, após o treinamento aeróbio, alguns autores não observam alterações na leptina plasmática, outros encontram alterações em função apenas das alterações da adiposidade e, por fim, alguns estudos observam diminuição da concentração plasmática e/ou expressão de leptina, independentemente de alterações da massa gorda. Tal fato sugere que haja outro, ou outros, fatores, além do conteúdo de gordura corporal, que modulam a diminuição das concentrações plasmáticas de leptina após o treinamento aeróbio, sendo a insulina a principal candidata a tal modulação. Dessa forma, esta revisão aborda os principais aspectos do hormônio leptina, sua ação, função e regulação, associação com a insulina, além dos efeitos do exercício físico agudo e crônico na síntese e secreção da leptina, e possíveis implicações da insulina e adiposidade em função desse estímulo.
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Niemelä SM, Miettinen S, Konttinen Y, Waris T, Kellomäki M, Ashammakhi NA, Ylikomi T. Fat tissue: views on reconstruction and exploitation. J Craniofac Surg 2007; 18:325-35. [PMID: 17414282 DOI: 10.1097/scs.0b013e3180333b6a] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Transplantation of autologous fat as pedicle or transposition flaps has been a classical method in plastic surgery for tissue reconstruction. The injection of fat for soft tissue reconstruction is also an old innovation. This approach has some significant drawbacks such as resorption of the fat transplant. To regenerate additional and self-regenerating adipose tissue for reconstructive purposes, a thorough understanding of adipose tissue (mesodermal stem cells, adipoblasts, pre-adipocytes, mature, lipid-synthesizing, and lipid-storing white or brown adipocytes) on cellular and molecular levels is required. Several transcription factors that play a central role in the control of adipogenesis have been identified. Among these are the CCAAT/enhancer binding protein gene family and peroxisome proliferator-activated receptor-gamma. Hormones and growth factors, such as insulin and insulin-like growth factor (IGF), transfer external signals to differentiating adipocytes. In an attempt to improve the quality of tissue-engineered fat by culture-expanded adipocytes, various pre-adipocyte and stem cell culture conditions and expansion methods have been developed. In the presence of fetal calf serum, spontaneous differentiation of pre-adipocytes into fat cell clusters occurs to some degree. This in vitro differentiation can be enhanced by addition of inducing agents such as dexamethasone, isobutylmethylxantine, and insulin into the culture medium. Recent work has shown the multipotency of pre-adipocytes, which are fibroblast-like precursors of adipocytes. With use of specific culture conditions, human adipose tissue-derived stem cells can be induced to express markers of adipocyte, osteoblast, and myocyte cell lineages. The multipotent characteristics of adipose tissue-derived stem cells, as well as their abundance and accessibility in the human body, make them a potential cell source for tissue engineering applications.
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Affiliation(s)
- Sanna-Mari Niemelä
- Department of Cell Biology, Medical School, University of Tampere, Tampere, and Department of Surgery, Oulu University Hospital, Oulu, Finland
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39
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Abstract
This review is focused on purinergic neurotransmission, i.e., ATP released from nerves as a transmitter or cotransmitter to act as an extracellular signaling molecule on both pre- and postjunctional membranes at neuroeffector junctions and synapses, as well as acting as a trophic factor during development and regeneration. Emphasis is placed on the physiology and pathophysiology of ATP, but extracellular roles of its breakdown product, adenosine, are also considered because of their intimate interactions. The early history of the involvement of ATP in autonomic and skeletal neuromuscular transmission and in activities in the central nervous system and ganglia is reviewed. Brief background information is given about the identification of receptor subtypes for purines and pyrimidines and about ATP storage, release, and ectoenzymatic breakdown. Evidence that ATP is a cotransmitter in most, if not all, peripheral and central neurons is presented, as well as full accounts of neurotransmission and neuromodulation in autonomic and sensory ganglia and in the brain and spinal cord. There is coverage of neuron-glia interactions and of purinergic neuroeffector transmission to nonmuscular cells. To establish the primitive and widespread nature of purinergic neurotransmission, both the ontogeny and phylogeny of purinergic signaling are considered. Finally, the pathophysiology of purinergic neurotransmission in both peripheral and central nervous systems is reviewed, and speculations are made about future developments.
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Affiliation(s)
- Geoffrey Burnstock
- Autonomic Neurscience Centre, Royal Free and University College Medical School, London, UK.
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40
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Burnstock G. Non-synaptic transmission at autonomic neuroeffector junctions. Neurochem Int 2007; 52:14-25. [PMID: 17493707 DOI: 10.1016/j.neuint.2007.03.007] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2007] [Accepted: 03/30/2007] [Indexed: 10/23/2022]
Abstract
Non-synaptic transmission is characteristic of autonomic neuroeffector junctions. The structure of the autonomic neuromuscular junction is described. The essential features are that: the terminal portions of autonomic nerve fibers are varicose and mobile, transmitters being released 'en passage' from varying distances from the effector cells; while there is no structural post-junctional specialization on effector cells, receptors for neurotransmitters accumulate on cell membranes at close junctions; muscle effectors are bundles rather than single smooth muscle cells, that are connected by gap junctions which allow electrotonic spread of activity between cells. A multiplicity of transmitters are utilized by autonomic nerves, and cotransmission occurs often involving synergistic actions of the cotransmitters, although pre- and post-junctional neuromodulation of neurotransmitter release also take place. It is suggested that autonomic neural control of immune, epithelial and endothelial cells also involves non-synaptic transmission.
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Affiliation(s)
- Geoffrey Burnstock
- Autonomic Neuroscience Centre, Royal Free and University College School of Medicine, Rowland Hill Street, London NW3 2PF, United Kingdom.
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41
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Dostalova I, Bartak V, Papezova H, Nedvidkova J. The effect of short-term exercise on plasma leptin levels in patients with anorexia nervosa. Metabolism 2007; 56:497-503. [PMID: 17379007 DOI: 10.1016/j.metabol.2006.11.008] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/02/2006] [Accepted: 11/13/2006] [Indexed: 11/20/2022]
Abstract
Plasma leptin concentrations are markedly reduced in malnourished patients with anorexia nervosa (AN). Whether the long-term underweight and low-fat stores affect the leptin response to exercise remains unknown. We investigated the effect of 45-minute cycle ergometer exercise (2 W kg-1 of lean body mass [LBM]) on plasma leptin, norepinephrine (NE), glycerol, and insulin levels in 10 patients with AN and in 15 healthy age-matched women (C). Plasma leptin levels immediately and 90 minutes after the exercise bout were significantly reduced compared with basal leptin levels in both AN and C groups (P<.05). Compared with the control trial, leptin levels were significantly lower immediately and 90 minutes after exercise in the AN group (P<.05) but not in the C group. Basal and exercise-induced plasma glycerol and NE levels did not differ significantly between the groups. Basal and exercise-induced plasma insulin levels were significantly lower in the AN group compared with the C group (P<.05). In conclusion, we demonstrated that a single bout of low-intensity exercise significantly reduces plasma leptin levels in patients with AN. In healthy women, exercise had no effect on lowering leptin concentrations beyond the diurnal decrease that occurs in the absence of exercise. Neither NE nor insulin are responsible for the different response of leptin to exercise in AN.
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Affiliation(s)
- Ivana Dostalova
- Laboratory of Clinical and Experimental Neuroendocrinology, Institute of Endocrinology, 116 94 Prague 1, Czech Republic.
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42
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Mattacks CA, Sadler D, Pond CM. The effects of dietary lipids on adrenergically-stimulated lipolysis in perinodal adipose tissue following prolonged activation of a single lymph node. Br J Nutr 2007. [DOI: 10.1079/bjn2002557] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The effects of feeding beef suet (mostly saturated and monoenoic fatty acids), sunflower oil (rich inn-6 fatty acids) and fish oil (rich inn-3 fatty acids) on the response of mesenteric, omental, popliteal and perirenal adipocytes to experimentally-induced local inflammation were studied in adult guinea pigs. After 6 weeks on the experimental diets, the animals were fed standard chow, and lipopolysaccharide was injected unilaterally daily for 4 d to induce swelling of one popliteal lymph node. Basal lipolysis in the perinodal adipocytes of all depots studied was higher in the sunflower oil-fed animals than in the controls fed on standard chow, and lower in those fed on suet or fish oil. Dietary lipids altered rates of lipolysis during incubation with 10-5M noradrenaline in all samples studied from the locally-activated popliteal depot, but only in adipocytes within 5 mm of a large lymph node in the other depots. The fish-oil diet attenuated the spread of increased lipolysis within the locally-activated popliteal adipose tissue, and from this depot to other node-containing depots. These experiments show thatn-6 polyunsaturated fatty acids promote andn-3 fatty acids suppress the spread of immune activation to adipocytes within and between depots, and alter the sensitivity of perinodal adipocytes to noradrenaline. Dietary effects are reduced or absent in adipocytes in sites remote from lymph nodes, and thus such samples do not adequately represent processes in perinodal adipose tissue. These results are consistent with the hypothesis that perinodal adipocytes interact with adjacent lymphoid cells during immune responses.
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43
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Mulligan JD, Gonzalez AA, Stewart AM, Carey HV, Saupe KW. Upregulation of AMPK during cold exposure occurs via distinct mechanisms in brown and white adipose tissue of the mouse. J Physiol 2007; 580:677-84. [PMID: 17272339 PMCID: PMC2075554 DOI: 10.1113/jphysiol.2007.128652] [Citation(s) in RCA: 91] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
AMPK (adenosine monophosphate-activated protein kinase), a key regulator of cellular energy metabolism and whole-body energy balance, is present in brown adipose tissue but its role in regulating the acute metabolic state and chronic thermogenic potential of this metabolically unique tissue is unknown. To address this, the AMPK signalling system in brown and white adipose tissue was studied in C57Bl/6 mice under control conditions, during acute and chronic cold exposure, and during chronic adrenergic stimulation. In control mice AMPK activity in brown adipose tissue was higher than in any tissue yet reported (3-fold the level in liver) secondary to a high level of expression of the alpha1 isoform. During the first day of cold, a time of intense non-shivering thermogenesis, AMPK activity remained at basal levels. However, chronic (>7 days) cold caused a progressive increase in brown adipose tissue AMPK activity secondary to increased expression of the alpha1 isoform. To investigate the signalling pathway involved, noradrenaline (norepinephrine) and the beta(3)-adrenergic-specific agonist CL 316, 243 were given for 14 days. This increased uncoupling protein-1 content in brown adipose tissue, but not AMPK activity. In white adipose tissue 15 days of cold increased alpha1 AMPK activity 98 +/- 20%, an effect reproduced by chronic noradrenaline or CL 316 243. We conclude that chronic cold not only increases AMPK activity in brown and white adipose tissue, but that it does so via distinct signalling pathways. Our data are consistent with AMPK acting primarily as a regulator of chronic thermogenic potential in brown adipose tissue, and not in the acute activation of non-shivering thermogenesis.
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Affiliation(s)
- Jacob D Mulligan
- Department of Medicine, University of Wisconsin, Madison, WI 53706, USA.
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44
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Zanquetta MM, Nascimento MEC, Mori RCT, D'Agord Schaan B, Young ME, Machado UF. Participation of beta-adrenergic activity in modulation of GLUT4 expression during fasting and refeeding in rats. Metabolism 2006; 55:1538-45. [PMID: 17046558 DOI: 10.1016/j.metabol.2006.06.026] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/21/2006] [Accepted: 06/20/2006] [Indexed: 12/01/2022]
Abstract
Through in vitro studies, several factors have been reported as modulators of GLUT4 gene expression. However, the role(s) of each potential GLUT4 modulator is not completely understood in the in vivo setting. The present study has investigated the hypothesis that beta-adrenergic stimulation participates in modulation of GLUT4 expression during fasting and refeeding. As such, GLUT4 messenger RNA (mRNA) and protein were investigated in insulin-sensitive tissues during a 48-hour fast. In addition, the effects of 8-hour refeeding on GLUT4 mRNA in the gastrocnemius muscle and interscapular brown adipose tissue (BAT) were investigated. Whether beta-adrenoceptor blockade by propranolol (20 mg/kg) treatment influenced the responsiveness to fasting/refeeding was also investigated. The results show that fasting repressed GLUT4 gene and protein expression in BAT, white adipose tissue, and soleus muscle, but had no effect on the gastrocnemius muscle. Refeeding induced a rapid overexpression of GLUT4 mRNA in both gastrocnemius (approximately 25%, P < .05) and BAT (approximately 200%, P < .001). Propranolol treatment induced an increase (approximately 60%, P < .05) in GLUT4 mRNA at the end of the fasting period. In contrast, propranolol treatment attenuated GLUT4 mRNA induction after refeeding; the latter may be due to attenuation of postprandial insulin levels. These results suggest that sympathetic activity is important for the repression of GLUT4 gene expression during fasting. In contrast, sympathetic control of the GLUT4 gene seems to be overbalanced by metabolic/hormonal modulators during refeeding stage. Taken together, the results suggest that feeding behavior influences GLUT4 gene expression pattern through changes in sympathetic activity, especially during long-term starvation periods.
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MESH Headings
- Adipose Tissue, Brown/metabolism
- Animals
- Blood Glucose/metabolism
- Blotting, Northern
- Blotting, Western
- Fasting/physiology
- Fatty Acids, Nonesterified/blood
- Gene Expression Regulation
- Glucose Transporter Type 4/biosynthesis
- Glucose Transporter Type 4/genetics
- Insulin/blood
- Male
- Muscle, Skeletal/metabolism
- RNA, Messenger/biosynthesis
- RNA, Messenger/genetics
- Rats
- Rats, Wistar
- Receptors, Adrenergic, beta/metabolism
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Affiliation(s)
- Melissa Moreira Zanquetta
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo, SP 05508-900, Brazil
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45
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Sprague JE, Yang X, Sommers J, Gilman TL, Mills EM. Roles of norepinephrine, free Fatty acids, thyroid status, and skeletal muscle uncoupling protein 3 expression in sympathomimetic-induced thermogenesis. J Pharmacol Exp Ther 2006; 320:274-80. [PMID: 17012607 DOI: 10.1124/jpet.106.107755] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Thyroid hormone (TH) plays a fundamental role in thermoregulation, yet the molecular mediators of its effects are not fully defined. Recently, skeletal muscle (SKM) uncoupling protein (UCP) 3 was shown to be an important mediator of the thermogenic effects of the widely abused sympathomimetic agents 3,4-methylenedioxymethamphetamine (MDMA; Ecstasy) and methamphetamine. Expression of UCP3 is regulated by TH. Activation of UCP3 is indirectly regulated by norepinephrine (NE) and is dependent upon the availability of free fatty acids (FFAs). We hypothesized that UCP3 may be a molecular link between TH and hyperthermia, requiring increased levels of both NE and FFAs to accomplish the thermogenic effect. Here, we demonstrate that MDMA (40 mg/kg s.c.) significantly increases plasma FFA levels 30 min after treatment. Pharmacologically increasing NE levels through the inhibition of phenylethanolamine N-methyltransferase with +/-2,3-dichloro-alpha-methylbenzylamine potentiated the hyperthermic effects of a 20 mg/kg dose of MDMA. Using Western blots and regression analysis, we further illustrated that chronic hyperthyroidism in rats potentiates the hyperthermic effects of MDMA and increases levels of SKM UCP3 protein in a linear fashion according to levels of circulating plasma TH. Conversely, chronic hypothyroidism results in a hypothermic response to MDMA that is directly proportionate to decreased UCP3 expression. Acute TH supplementation did not change the skeletal muscle UCP3 expression levels or temperature responses to MDMA. These findings suggest that, although MDMA-induced hyperthermia appears to result from increased NE and FFA levels, susceptibility is ultimately determined by TH regulation of UCP3-dependent thermogenesis.
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Affiliation(s)
- Jon E Sprague
- The Department of Pharmaceutical and Biomedical Sciences, The Raabe College of Pharmacy, Ohio Northern University, Ada, Ohio, USA
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46
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Bartolomucci A, La Corte G, Possenti R, Locatelli V, Rigamonti AE, Torsello A, Bresciani E, Bulgarelli I, Rizzi R, Pavone F, D’Amato FR, Severini C, Mignogna G, Giorgi A, Schininà ME, Elia G, Brancia C, Ferri GL, Conti R, Ciani B, Pascucci T, Dell’Omo G, Muller EE, Levi A, Moles A. TLQP-21, a VGF-derived peptide, increases energy expenditure and prevents the early phase of diet-induced obesity. Proc Natl Acad Sci U S A 2006; 103:14584-9. [PMID: 16983076 PMCID: PMC1600003 DOI: 10.1073/pnas.0606102103] [Citation(s) in RCA: 117] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
The vgf gene has been identified as an energy homeostasis regulator. Vgf encodes a 617-aa precursor protein that is processed to yield an incompletely characterized panel of neuropeptides. Until now, it was an unproved assumption that VGF-derived peptides could regulate metabolism. Here, a VGF peptide designated TLQP-21 was identified in rat brain extracts by means of immunoprecipitation, microcapillary liquid chromatography-tandem MS, and database searching algorithms. Chronic intracerebroventricular (i.c.v.) injection of TLQP-21 (15 mug/day for 14 days) increased resting energy expenditure (EE) and rectal temperature in mice. These effects were paralleled by increased epinephrine and up-regulation of brown adipose tissue beta2-AR (beta2 adrenergic receptor) and white adipose tissue (WAT) PPAR-delta (peroxisome proliferator-activated receptor delta), beta3-AR, and UCP1 (uncoupling protein 1) mRNAs and were independent of locomotor activity and thyroid hormones. Hypothalamic gene expression of orexigenic and anorexigenic neuropeptides was unchanged. Furthermore, in mice that were fed a high-fat diet for 14 days, TLQP-21 prevented the increase in body and WAT weight as well as hormonal changes that are associated with a high-fat regimen. Biochemical and molecular analyses suggest that TLQP-21 exerts its effects by stimulating autonomic activation of adrenal medulla and adipose tissues. In conclusion, we present here the identification in the CNS of a previously uncharacterized VGF-derived peptide and prove that its chronic i.c.v. infusion effected an increase in EE and limited the early phase of diet-induced obesity.
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Affiliation(s)
- A. Bartolomucci
- Institute of Neuroscience, Consiglio Nazionale delle Ricerche, 00143 Rome, Italy
- To whom correspondence may be addressed. E-mail:
, , or
| | - G. La Corte
- Institute of Neurobiology and Molecular Medicine, Consiglio Nazionale delle Ricerche, 00143 Rome, Italy
| | - R. Possenti
- Institute of Neurobiology and Molecular Medicine, Consiglio Nazionale delle Ricerche, 00143 Rome, Italy
- Department of Neuroscience, University of Roma II–Tor Vergata, 00161 Rome, Italy
| | - V. Locatelli
- Department of Experimental and Environmental Medicine and Biotechnology and Interdepartmental Center for Bioinformatics and Proteomics, University of Milan–Bicocca, 20052 Monza, Italy
| | - A. E. Rigamonti
- Department of Pharmacology, Chemotherapy, and Medical Toxicology, University of Milan, 20129 Milan, Italy
| | - A. Torsello
- Department of Experimental and Environmental Medicine and Biotechnology and Interdepartmental Center for Bioinformatics and Proteomics, University of Milan–Bicocca, 20052 Monza, Italy
| | - E. Bresciani
- Department of Experimental and Environmental Medicine and Biotechnology and Interdepartmental Center for Bioinformatics and Proteomics, University of Milan–Bicocca, 20052 Monza, Italy
| | - I. Bulgarelli
- Department of Experimental and Environmental Medicine and Biotechnology and Interdepartmental Center for Bioinformatics and Proteomics, University of Milan–Bicocca, 20052 Monza, Italy
| | - R. Rizzi
- Department of Neuroscience, University of Roma II–Tor Vergata, 00161 Rome, Italy
| | - F. Pavone
- Institute of Neuroscience, Consiglio Nazionale delle Ricerche, 00143 Rome, Italy
| | - F. R. D’Amato
- Institute of Neuroscience, Consiglio Nazionale delle Ricerche, 00143 Rome, Italy
| | - C. Severini
- Institute of Neurobiology and Molecular Medicine, Consiglio Nazionale delle Ricerche, 00143 Rome, Italy
| | - G. Mignogna
- Department of Biochemical Science, University “La Sapienza,” 00185 Rome, Italy
| | - A. Giorgi
- Department of Biochemical Science, University “La Sapienza,” 00185 Rome, Italy
| | - M. E. Schininà
- Department of Biochemical Science, University “La Sapienza,” 00185 Rome, Italy
| | - G. Elia
- Department of Chemistry and Applied Biosciences, Institute of Pharmaceutical Sciences, Eidgenössische Technische Hochschule Zürich, CH-8093 Zürich, Switzerland
| | - C. Brancia
- NEF Laboratory, Department of Cytomorphology, University of Cagliari, 09042 Monserrato, Italy
| | - G.-L. Ferri
- NEF Laboratory, Department of Cytomorphology, University of Cagliari, 09042 Monserrato, Italy
| | - R. Conti
- Department of Endocrinology and Metabolism, Sigma-Tau Pharmaceuticals Industries S.p.A., 00040 Rome, Italy
| | - B. Ciani
- Department of Endocrinology and Metabolism, Sigma-Tau Pharmaceuticals Industries S.p.A., 00040 Rome, Italy
| | - T. Pascucci
- Foundation Santa Lucia, 00143 Rome, Italy; and
| | - G. Dell’Omo
- Institute of Anatomy and Center for Neuroscience, University of Zürich, CH-8057 Zürich, Switzerland
| | - E. E. Muller
- Department of Pharmacology, Chemotherapy, and Medical Toxicology, University of Milan, 20129 Milan, Italy
| | - A. Levi
- Institute of Neurobiology and Molecular Medicine, Consiglio Nazionale delle Ricerche, 00143 Rome, Italy
- To whom correspondence may be addressed. E-mail:
, , or
| | - A. Moles
- Institute of Neuroscience, Consiglio Nazionale delle Ricerche, 00143 Rome, Italy
- To whom correspondence may be addressed. E-mail:
, , or
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47
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Kuo AY, Lee JC, Magnin G, Siegel PB, Denbow DM. Differential autonomic nervous system response in obese and anorexic chickens (Gallus gallus). Comp Biochem Physiol B Biochem Mol Biol 2006; 144:359-64. [PMID: 16750926 DOI: 10.1016/j.cbpb.2006.03.012] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2005] [Revised: 03/22/2006] [Accepted: 03/27/2006] [Indexed: 10/24/2022]
Abstract
Effect of reserpine on body weight (BW), feed intake (FI), brain and plasma catecholamine and indoleamine concentrations in high- (HWS) and low- (LWS) weight selected lines of chickens was investigated. Chicks from each line were assigned to three treatment groups and injected intraperitoneally with 0, 1.25, or 2.50 mg/kg of reserpine at hatch, and again at 5 weeks-of-age. Chick BW and FI were determined weekly. At 7 weeks-of-age, 12 males and females from each group were sacrificed for neurotransmitter analysis. In the HWS line there was a dose-dependent decrease in BW through 7 weeks-of-age, whereas in the LWS line BW decreased only through the first 2 weeks-of-age. In the LWS line, norepinephrine (NE), epinephrine, and 3,4-dihydroxyphenylacetate concentrations decreased in the brain in a linear and quadratic manner in response to reserpine, but not in the HWS line. Both lines showed linear decreases in dopamine levels in response to reserpine; however, serotonin was not affected by reserpine. Chickens in the HWS line had greater plasma NE, and lower 5-hydroxyindoleacetic acid than those in the LWS line. In conclusion, it appears that chickens from the HWS line were more sensitive to the BW reducing effects of reserpine than those from the LWS line, with the latter appearing to have greater sympathetic nervous system activity.
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Affiliation(s)
- Alice Y Kuo
- Department of Animal and Poultry Sciences, 0306, Virginia Polytechnic Institute and State University, Blacksburg, 24061, USA
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48
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Giordano A, Song CK, Bowers RR, Ehlen JC, Frontini A, Cinti S, Bartness TJ. White adipose tissue lacks significant vagal innervation and immunohistochemical evidence of parasympathetic innervation. Am J Physiol Regul Integr Comp Physiol 2006; 291:R1243-55. [PMID: 16809481 DOI: 10.1152/ajpregu.00679.2005] [Citation(s) in RCA: 118] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Converging evidence indicates that white adipose tissue (WAT) is innervated by the sympathetic nervous system (SNS) based on immunohistochemical labeling of a SNS marker (tyrosine hydroxylase [TH]), tract tracing of WAT sympathetic postganglionic innervation, pseudorabies virus (PRV) transneuronal labeling of WAT SNS outflow neurons, and functional evidence from denervation studies. Recently, WAT para-SNS (PSNS) innervation was suggested because local surgical WAT sympathectomy (sparing hypothesized parasympathetic innervation) followed by PRV injection yielded infected cells in the vagal dorsomotor nucleus (DMV), a traditionally-recognized PSNS brain stem site. In addition, local surgical PSNS WAT denervation triggered WAT catabolic responses. We tested histologically whether WAT was parasympathetically innervated by searching for PSNS markers in rat, and normal (C57BL) and obese (ob/ob) mouse WAT. Vesicular acetylcholine transporter, vasoactive intestinal peptide and neuronal nitric oxide synthase immunoreactivities were absent in WAT pads (retroperitoneal, epididymal, inguinal subcutaneous) from all animals. Nearly all nerves innervating WAT vasculature and parenchyma that were labeled with protein gene product 9.5 (PGP9.5; pan-nerve marker) also contained TH, attesting to pervasive SNS innervation. When Siberian hamster inguinal WAT was sympathetically denervated via local injections of catecholaminergic toxin 6-hydroxydopamine (sparing putative parasympathetic nerves), subsequent PRV injection resulted in no central nervous system (CNS) or sympathetic chain infections suggesting no PSNS innervation. By contrast, vehicle-injected WAT subsequently inoculated with PRV had typical CNS/sympathetic chain viral infection patterns. Collectively, these data indicate no parasympathetic nerve markers in WAT of several species, with sparse DMV innervation and question the claim of PSNS WAT innervation as well as its functional significance.
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Affiliation(s)
- Antonio Giordano
- Institute of Normal Human Morphology, Marche Polytechnic University, Ancona, Italy
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49
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LoVerme J, Guzmán M, Gaetani S, Piomelli D. Cold exposure stimulates synthesis of the bioactive lipid oleoylethanolamide in rat adipose tissue. J Biol Chem 2006; 281:22815-8. [PMID: 16785227 DOI: 10.1074/jbc.m604751200] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Oleoylethanolamide (OEA) is an endogenous lipid mediator that inhibits feeding and stimulates lipolysis by activating the nuclear receptor peroxisome proliferator-activating receptor-alpha. Little is known about the physiological regulation of this compound outside of the gastrointestinal tract, where its production is regulated by feeding. Here we show that cold exposure increases OEA levels in rat white adipose tissue but not in liver or intestine. This change is accompanied by parallel elevations in the activity of N-acyltransferase, a key enzyme responsible for OEA synthesis, without concomitant changes in fatty acid amide hydrolase, an enzyme responsible for OEA degradation. Moreover, cold stimulates the production of two species of N-oleoylphosphatidylethanolamine OEA precursors. The changes in OEA biosynthesis are reversed by pretreatment with the beta-receptor antagonist propranolol, suggesting a role for beta-adrenoreceptors in this response. In agreement with these findings, the beta-agonists noradrenaline and isoproterenol stimulate OEA production in isolated adipocytes, an effect that is mimicked by the adenylyl cyclase activator forskolin. Collectively, these results identify cold exposure as a natural stimulus for OEA formation in white fat and suggest a role for the sympathetic nervous system in regulating OEA biosynthesis.
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Affiliation(s)
- Jesse LoVerme
- Center for Drug Discovery, and Department of Pharmacology, University of California, Irvine, California 92697, USA
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50
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Xie T, Plagge A, Gavrilova O, Pack S, Jou W, Lai EW, Frontera M, Kelsey G, Weinstein LS. The alternative stimulatory G protein alpha-subunit XLalphas is a critical regulator of energy and glucose metabolism and sympathetic nerve activity in adult mice. J Biol Chem 2006; 281:18989-99. [PMID: 16672216 PMCID: PMC1490322 DOI: 10.1074/jbc.m511752200] [Citation(s) in RCA: 80] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The complex imprinted Gnas locus encodes several gene products including G(s)alpha, the ubiquitously expressed G protein alpha-subunit required for receptor-stimulated cAMP generation, and the neuroendocrine-specific G(s)alpha isoform XLalphas. XLalphas is only expressed from the paternal allele, whereas G(s)alpha is biallelically expressed in most tissues. XLalphas knock-out mice (Gnasxl(m+/p-)) have poor suckling and perinatal lethality, implicating XLalphas as critical for postnatal feeding. We have now examined the metabolic phenotype of adult Gnasxl(m+/p-) mice. Gnasxl(m+/p-) mice had reduced fat mass and lipid accumulation in adipose tissue, with increased food intake and metabolic rates. Gene expression profiling was consistent with increased lipid metabolism in adipose tissue. These changes likely result from increased sympathetic nervous system activity rather than adipose cell-autonomous effects, as we found that XLalphas is not normally expressed in adult adipose tissue, and Gnasxl(m+/p-) mice had increased urinary norepinephrine levels but not increased metabolic responsiveness to a beta3-adrenergic agonist. Gnasxl(m+/p-) mice were hypolipidemic and had increased glucose tolerance and insulin sensitivity. The similar metabolic profile observed in some prior paternal Gnas knock-out models results from XLalphas deficiency (or deficiency of the related alternative truncated protein XLN1). XLalphas (or XLN1) is a negative regulator of sympathetic nervous system activity in mice.
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Affiliation(s)
- Tao Xie
- From the Metabolic Diseases Branch and
| | - Antonius Plagge
- Laboratory of Developmental Genetics and Imprinting, The Babraham Institute, Cambridge, United Kingdom
| | - Oksana Gavrilova
- Mouse Metabolism Core Laboratory, National Institute of Diabetes, Digestive, and Kidney Diseases
| | - Stephanie Pack
- Mouse Metabolism Core Laboratory, National Institute of Diabetes, Digestive, and Kidney Diseases
| | - William Jou
- Mouse Metabolism Core Laboratory, National Institute of Diabetes, Digestive, and Kidney Diseases
| | - Edwin W. Lai
- Reproductive Biology and Medicine Branch, National Institute of Child Health and Human Development, and
- Clinical Neurocardiology Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland 20892 and
| | - Marga Frontera
- Laboratory of Developmental Genetics and Imprinting, The Babraham Institute, Cambridge, United Kingdom
| | - Gavin Kelsey
- Laboratory of Developmental Genetics and Imprinting, The Babraham Institute, Cambridge, United Kingdom
| | - Lee S. Weinstein
- From the Metabolic Diseases Branch and
- Address correspondence to: Lee S. Weinstein, Metabolic Diseases Branch, NIDDK/NIH, Bldg 10 Rm 8C101, Bethesda, Maryland 20892-1752 USA; Phone 301-402-2923; FAX 301-402-0374; E-mail:
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