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Adeli A, Zendehdel M, Babapour V, Panahi N. Interaction between leptin and glutamatergic system on food intake regulation in neonatal chicken: role of NMDA and AMPA receptors. Int J Neurosci 2020; 130:713-721. [PMID: 31813315 DOI: 10.1080/00207454.2019.1702983] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Objective: The aim of the current study was to determine the possible interaction of the central leptin and Glutamatergic systems on feeding behavior in neonatal 3-hours food deprived (FD3) broilers chickens.Methods: In experiment 1, FD3 chicken received intracerebroventricular (ICV) injection of control solution (group i) and 2.5, 5 and 10 µg of Leptin (groups ii-iv). In experiment 2, FD3 chicken were ICV injected with (group i) control solution and groups ii-iv with 2.5, 5 and 10 nmol of AG-490 (JAK2 antagonist). In experiment 3, injections were (i) control solution, (ii) Leptin (10 µg), (iii) AG-490 (2.5 nmol) and (iv) Leptin + AG-490. In experiment 4, broiler chickens were ICV injected with (i) control solution, (ii) Leptin (10 µg), (iii) MK-801 (NMDA glutamate receptors antagonist; 15 nmol) and (iv) Leptin + MK-801. Experiments 5-9 were similar to experiment 1, except chicken were ICV injected with CNQX (AMPA receptor antagonist, 390 nmol), UBP-302 (Kainate receptor antagonist, 390 nmol), AIDA (mGluR1 antagonist, 2 nmol), LY341495 (mGluR2 antagonist, 150 nmol) and UBP1112 (mGluR3 antagonist, 2 nmol) instead of MK-801. Then, food intake was measured until 120 min after injection.Results: ICV injection of leptin (2.5, 5 and 10 µg) significantly decreased food intake in a dose dependent manner (p < 0.05). Also, ICV injection of the JAK2 antagonist (2.5, 5 and 10 nmol) had hyperphagic effect in chicken (p < 0.05). Co-administration of leptin + AG-490, partially decreased leptin-induced hypophagia in broiler chicken (p < 0.05). In addition, co-injection of leptin + MK-801 significalty inhibited leptin-induced hypophagia in neonatal chicken (p < 0.05). Also, co-administration of leptin + CNQX partially attenuated hypophagic effect of leptin in chicken (p < 0.05).Conclusion: The results of present study suggest that leptin has hypophagic effect in neonatal chicken and this effect is probably mediated via NMDA and AMPA glutamatergic receptors.
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Affiliation(s)
- Amin Adeli
- Department of Basic Sciences, Faculty of Veterinary Medicine, Science and Research Branch, Islamic Azad University, Tehran, Iran
| | - Morteza Zendehdel
- Department of Basic Sciences, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran
| | - Vahab Babapour
- Department of Basic Sciences, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran
| | - Negar Panahi
- Department of Basic Sciences, Faculty of Veterinary Medicine, Science and Research Branch, Islamic Azad University, Tehran, Iran
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Chowen JA, Garcia-Segura LM. Microglia, neurodegeneration and loss of neuroendocrine control. Prog Neurobiol 2020; 184:101720. [DOI: 10.1016/j.pneurobio.2019.101720] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2019] [Revised: 10/19/2019] [Accepted: 11/02/2019] [Indexed: 02/07/2023]
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Daniele G, Campi B, Saba A, Codini S, Ciccarone A, Giusti L, Del Prato S, Esterline RL, Ferrannini E. Plasma N-Acetylaspartate Is Related to Age, Obesity, and Glucose Metabolism: Effects of Antidiabetic Treatment and Bariatric Surgery. Front Endocrinol (Lausanne) 2020; 11:216. [PMID: 32362872 PMCID: PMC7181885 DOI: 10.3389/fendo.2020.00216] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/07/2019] [Accepted: 03/25/2020] [Indexed: 01/06/2023] Open
Abstract
Background: N-acetylaspartate (NAA) is synthesized only by neurons and is involved in neuronal metabolism and axonal myelination. NAA is the strongest signal on brain magnetic resonance spectroscopy, and its concentration have been associated with cognitive dysfunction in neurodegenerative diseases, obesity, and type 2 diabetes (T2D). Materials and Methods: We explored the impact of obesity and T2D on circulating NAA as well as the impact of bariatric surgery and antidiabetic treatments. We developed an LC-MS method for the accurate measurements of fasting plasma NAA levels in 505 subjects (156 subjects with normal glucose tolerance, 24 subjects with impaired glucose tolerance, and 325 patients with T2D) to examine the associations of NAA with obesity and dysglycemia. To validate cross-sectional findings, plasma NAA was measured 6 months after Roux-en-Y Gastric Bypass (RYGB) in 55 morbidly obese subjects, and after 1 year of antidiabetic treatment (with dapagliflozin, exenatide, or dapagliflozin plus exenatide) in 192 T2D patients. Results: In the whole population, NAA was associated with age (r = 0.31, p <0.0001) and BMI (r = -0.20, p <0.0001). Independently of age and BMI, NAA was reciprocally related to HbA1c and fasting plasma glucose (partial r = -0.13, both p = 0.01). Surgically-induced weight loss raised NAA (by 18 nmol/L on average, p <0.02). Glucose lowering treatment increased NAA in proportion to the drop in HbA1c (r = 0.31, p <0.0001) regardless of the agent used. Conclusions: Circulating NAA concentrations are modulated by age, obesity, and glycemic control. Whether they may mark for the corresponding metabolic effects on brain function remains to be established by joint measurements of spectroscopic signal and cognitive function.
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Affiliation(s)
- Giuseppe Daniele
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | | | - Alessandro Saba
- Department of Surgical, Medical and Molecular Pathology and Critical Care Medicine, University of Pisa, Pisa, Italy
- Laboratory of Clinical Pathology, St. Chiara University Hospital, Pisa, Italy
| | - Simone Codini
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - Annamaria Ciccarone
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - Laura Giusti
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - Stefano Del Prato
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | | | - Ele Ferrannini
- C.N.R. Institute of Clinical Physiology, Pisa, Italy
- *Correspondence: Ele Ferrannini
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54
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MacDonald AJ, Holmes FE, Beall C, Pickering AE, Ellacott KLJ. Regulation of food intake by astrocytes in the brainstem dorsal vagal complex. Glia 2019; 68:1241-1254. [PMID: 31880353 PMCID: PMC7187409 DOI: 10.1002/glia.23774] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2019] [Revised: 12/13/2019] [Accepted: 12/17/2019] [Indexed: 02/06/2023]
Abstract
A role for glial cells in brain circuits controlling feeding has begun to be identified with hypothalamic astrocyte signaling implicated in regulating energy homeostasis. The nucleus of the solitary tract (NTS), within the brainstem dorsal vagal complex (DVC), integrates vagal afferent information from the viscera and plays a role in regulating food intake. We hypothesized that astrocytes in this nucleus respond to, and influence, food intake. Mice fed high‐fat chow for 12 hr during the dark phase showed NTS astrocyte activation, reflected in an increase in the number (65%) and morphological complexity of glial‐fibrillary acidic protein (GFAP)‐immunoreactive cells adjacent to the area postrema (AP), compared to control chow fed mice. To measure the impact of astrocyte activation on food intake, we delivered designer receptors exclusively activated by designer drugs (DREADDs) to DVC astrocytes (encompassing NTS, AP, and dorsal motor nucleus of the vagus) using an adeno‐associated viral (AAV) vector (AAV‐GFAP‐hM3Dq_mCherry). Chemogenetic activation with clozapine‐N‐oxide (0.3 mg/kg) produced in greater morphological complexity in astrocytes and reduced dark‐phase feeding by 84% at 4 hr postinjection compared with vehicle treatment. hM3Dq‐activation of DVC astrocytes also reduced refeeding after an overnight fast (71% lower, 4 hr postinjection) when compared to AAV‐GFAP‐mCherry expressing control mice. DREADD‐mediated astrocyte activation did not impact locomotion. hM3Dq activation of DVC astrocytes induced c‐FOS in neighboring neuronal feeding circuits (including in the parabrachial nucleus). This indicates that NTS astrocytes respond to acute nutritional excess, are involved in the integration of peripheral satiety signals, and can reduce food intake when activated.
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Affiliation(s)
- Alastair J MacDonald
- Institute of Biomedical and Clinical Sciences, University of Exeter Medical School, Exeter, UK.,School of Physiology, Pharmacology and Neuroscience, University of Bristol, Biomedical Sciences Building, University Walk, Bristol, UK
| | - Fiona E Holmes
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Biomedical Sciences Building, University Walk, Bristol, UK
| | - Craig Beall
- Institute of Biomedical and Clinical Sciences, University of Exeter Medical School, Exeter, UK
| | - Anthony E Pickering
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Biomedical Sciences Building, University Walk, Bristol, UK.,Anaesthesia, Pain and Critical Care Sciences, Translational Health Sciences, Bristol Medical School, University of Bristol, Bristol, UK
| | - Kate L J Ellacott
- Institute of Biomedical and Clinical Sciences, University of Exeter Medical School, Exeter, UK
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55
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Fujita Y, Yamashita T. The Effects of Leptin on Glial Cells in Neurological Diseases. Front Neurosci 2019; 13:828. [PMID: 31447640 PMCID: PMC6692660 DOI: 10.3389/fnins.2019.00828] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2019] [Accepted: 07/25/2019] [Indexed: 12/11/2022] Open
Abstract
It is known that various endocrine modulators, including leptin and ghrelin, have neuroprotective roles in neurological diseases. Leptin is a hormone produced by adipocytes and was originally identified as a gene related to obesity in mice. The leptin receptors in the hypothalamus are the main target for the homeostatic regulation of body weight. Recent studies have demonstrated that leptin receptors are also expressed in other regions of the central nervous system (CNS), such as the hippocampus, cerebral cortex, and spinal cord. Accordingly, these studies identified the involvement of leptin in the regulation of neuronal survival and neural development. Furthermore, leptin has been shown to have neuroprotective functions in animal models of neurological diseases and demyelination. These observations also suggest that dysregulation of leptin signaling may be involved in the association between neurodegeneration and obesity. In this review, we summarize novel functions of leptin in animal models of neurodegenerative diseases. Specifically, we focus on the emerging evidence for the role of leptin in non-neuronal cells in the CNS, including astrocytes, microglia, and oligodendrocytes. Understanding leptin-mediated neuroprotective signals and molecular mechanisms underlying remyelination will be helpful to establish therapeutic strategies against neurological diseases.
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Affiliation(s)
- Yuki Fujita
- Department of Molecular Neuroscience, Graduate School of Medicine, Osaka University, Osaka, Japan.,WPI Immunology Frontier Research Center, Osaka University, Osaka, Japan
| | - Toshihide Yamashita
- Department of Molecular Neuroscience, Graduate School of Medicine, Osaka University, Osaka, Japan.,WPI Immunology Frontier Research Center, Osaka University, Osaka, Japan.,Graduate School of Frontier Biosciences, Osaka University, Osaka, Japan.,Department of Neuro-Medical Science, Graduate School of Medicine, Osaka University, Osaka, Japan
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56
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Cresto N, Pillet LE, Billuart P, Rouach N. Do Astrocytes Play a Role in Intellectual Disabilities? Trends Neurosci 2019; 42:518-527. [PMID: 31300246 DOI: 10.1016/j.tins.2019.05.011] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2019] [Revised: 05/06/2019] [Accepted: 05/31/2019] [Indexed: 11/29/2022]
Abstract
Neurodevelopmental disorders, including those involving intellectual disability, are characterized by abnormalities in formation and functions of synaptic circuits. Traditionally, research on synaptogenesis and synaptic transmission in health and disease focused on neurons, however, a growing number of studies have highlighted the role of astrocytes in this context. Tight structural and functional interactions of astrocytes and synapses indeed play important roles in brain functions, and the repertoire of astroglial regulations of synaptic circuits is large and complex. Recently, genetic studies of intellectual disabilities have underscored potential contributions of astrocytes in the pathophysiology of these disorders. Here we review how alterations of astrocyte functions in disease may interfere with neuronal excitability and the balance of excitatory and inhibitory transmission during development, and contribute to intellectual disabilities.
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Affiliation(s)
- Noémie Cresto
- Neuroglial Interactions in Cerebral Physiopathology, Center for Interdisciplinary Research in Biology, Collège de France, CNRS UMR 7241, INSERM U1050, 75005 Paris, France; Université de Paris, Institut de Psychiatrie et de Neuroscience de Paris, INSERM U1266, Paris, France
| | - Laure-Elise Pillet
- Neuroglial Interactions in Cerebral Physiopathology, Center for Interdisciplinary Research in Biology, Collège de France, CNRS UMR 7241, INSERM U1050, 75005 Paris, France; Université de Paris, Institut de Psychiatrie et de Neuroscience de Paris, INSERM U1266, Paris, France; Doctoral School N°562, Paris Descartes University, Paris 75006, France
| | - Pierre Billuart
- Université de Paris, Institut de Psychiatrie et de Neuroscience de Paris, INSERM U1266, Paris, France.
| | - Nathalie Rouach
- Neuroglial Interactions in Cerebral Physiopathology, Center for Interdisciplinary Research in Biology, Collège de France, CNRS UMR 7241, INSERM U1050, 75005 Paris, France.
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57
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Fuente-Martín E, Mellado-Gil JM, Cobo-Vuilleumier N, Martín-Montalvo A, Romero-Zerbo SY, Diaz Contreras I, Hmadcha A, Soria B, Martin Bermudo F, Reyes JC, Bermúdez-Silva FJ, Lorenzo PI, Gauthier BR. Dissecting the Brain/Islet Axis in Metabesity. Genes (Basel) 2019; 10:genes10050350. [PMID: 31072002 PMCID: PMC6562925 DOI: 10.3390/genes10050350] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2019] [Revised: 05/02/2019] [Accepted: 05/02/2019] [Indexed: 12/17/2022] Open
Abstract
The high prevalence of type 2 diabetes mellitus (T2DM), together with the fact that current treatments are only palliative and do not avoid major secondary complications, reveals the need for novel approaches to treat the cause of this disease. Efforts are currently underway to identify therapeutic targets implicated in either the regeneration or re-differentiation of a functional pancreatic islet β-cell mass to restore insulin levels and normoglycemia. However, T2DM is not only caused by failures in β-cells but also by dysfunctions in the central nervous system (CNS), especially in the hypothalamus and brainstem. Herein, we review the physiological contribution of hypothalamic neuronal and glial populations, particularly astrocytes, in the control of the systemic response that regulates blood glucose levels. The glucosensing capacity of hypothalamic astrocytes, together with their regulation by metabolic hormones, highlights the relevance of these cells in the control of glucose homeostasis. Moreover, the critical role of astrocytes in the response to inflammation, a process associated with obesity and T2DM, further emphasizes the importance of these cells as novel targets to stimulate the CNS in response to metabesity (over-nutrition-derived metabolic dysfunctions). We suggest that novel T2DM therapies should aim at stimulating the CNS astrocytic response, as well as recovering the functional pancreatic β-cell mass. Whether or not a common factor expressed in both cell types can be feasibly targeted is also discussed.
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Affiliation(s)
- Esther Fuente-Martín
- Andalusian Center of Molecular Biology and Regenerative Medicine-CABIMER, Junta de Andalucia-University of Pablo de Olavide-University of Seville-CSIC, 41092 Seville, Spain.
| | - Jose M Mellado-Gil
- Andalusian Center of Molecular Biology and Regenerative Medicine-CABIMER, Junta de Andalucia-University of Pablo de Olavide-University of Seville-CSIC, 41092 Seville, Spain.
| | - Nadia Cobo-Vuilleumier
- Andalusian Center of Molecular Biology and Regenerative Medicine-CABIMER, Junta de Andalucia-University of Pablo de Olavide-University of Seville-CSIC, 41092 Seville, Spain.
| | - Alejandro Martín-Montalvo
- Andalusian Center of Molecular Biology and Regenerative Medicine-CABIMER, Junta de Andalucia-University of Pablo de Olavide-University of Seville-CSIC, 41092 Seville, Spain.
| | - Silvana Y Romero-Zerbo
- Instituto de Investigación Biomédica de Málaga-IBIMA, UGC Endocrinología y Nutrición. Hospital Regional Universitario de Málaga, 29009 Málaga, Spain.
| | - Irene Diaz Contreras
- Andalusian Center of Molecular Biology and Regenerative Medicine-CABIMER, Junta de Andalucia-University of Pablo de Olavide-University of Seville-CSIC, 41092 Seville, Spain.
- Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), 28029 Madrid, Spain.
| | - Abdelkrim Hmadcha
- Andalusian Center of Molecular Biology and Regenerative Medicine-CABIMER, Junta de Andalucia-University of Pablo de Olavide-University of Seville-CSIC, 41092 Seville, Spain.
- Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), 28029 Madrid, Spain.
| | - Bernat Soria
- Andalusian Center of Molecular Biology and Regenerative Medicine-CABIMER, Junta de Andalucia-University of Pablo de Olavide-University of Seville-CSIC, 41092 Seville, Spain.
- Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), 28029 Madrid, Spain.
| | - Francisco Martin Bermudo
- Andalusian Center of Molecular Biology and Regenerative Medicine-CABIMER, Junta de Andalucia-University of Pablo de Olavide-University of Seville-CSIC, 41092 Seville, Spain.
- Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), 28029 Madrid, Spain.
| | - Jose C Reyes
- Andalusian Center of Molecular Biology and Regenerative Medicine-CABIMER, Junta de Andalucia-University of Pablo de Olavide-University of Seville-CSIC, 41092 Seville, Spain.
| | - Francisco J Bermúdez-Silva
- Instituto de Investigación Biomédica de Málaga-IBIMA, UGC Endocrinología y Nutrición. Hospital Regional Universitario de Málaga, 29009 Málaga, Spain.
- Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), 28029 Madrid, Spain.
| | - Petra I Lorenzo
- Andalusian Center of Molecular Biology and Regenerative Medicine-CABIMER, Junta de Andalucia-University of Pablo de Olavide-University of Seville-CSIC, 41092 Seville, Spain.
| | - Benoit R Gauthier
- Andalusian Center of Molecular Biology and Regenerative Medicine-CABIMER, Junta de Andalucia-University of Pablo de Olavide-University of Seville-CSIC, 41092 Seville, Spain.
- Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), 28029 Madrid, Spain.
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Chowen JA, Frago LM, Fernández-Alfonso MS. Physiological and pathophysiological roles of hypothalamic astrocytes in metabolism. J Neuroendocrinol 2019; 31:e12671. [PMID: 30561077 DOI: 10.1111/jne.12671] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/15/2018] [Revised: 11/27/2018] [Accepted: 12/11/2018] [Indexed: 12/26/2022]
Abstract
The role of glial cells, including astrocytes, in metabolic control has received increasing attention in recent years. Although the original interest in these macroglial cells was a result of astrogliosis being observed in the hypothalamus of diet-induced obese subjects, studies have also focused on how they participate in the physiological control of appetite and energy expenditure. Astrocytes express receptors for numerous hormones, growth factors and neuropeptides. Some functions of astrocytes include transport of nutrients and hormones from the circulation to the brain, storage of glycogen, participation in glucose sensing, synaptic plasticity, uptake and metabolism of neurotransmitters, release of substances to modify neurotransmission, and cytokine production, amongst others. In the hypothalamus, these physiological glial functions impact on neuronal circuits that control systemic metabolism to modify their outputs. The initial response of astrocytes to poor dietary habits and obesity involves activation of neuroprotective mechanisms but, with chronic exposure to these situations, hypothalamic astrocytes participate in the development of some of the damaging secondary effects. The present review discusses not only some of the physiological functions of hypothalamic astrocytes in metabolism, but also their role in the secondary complications of obesity, such as insulin resistance and cardiovascular affectations.
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Affiliation(s)
- Julie A Chowen
- Department of Endocrinology, Hospital Infantil Universitario Niño Jesús, Instituto de Investigación la Princesa, Madrid, Spain
- CIBEROBN (Centro de Investigación Biomédica en Red sobre Fisiopatología de la Obesidad y Nutrición), Instituto de Salud Carlos III, Madrid, Spain
- IMDEA Food Institute, CEI UAM + CSIC, Madrid, Spain
| | - Laura M Frago
- Department of Endocrinology, Hospital Infantil Universitario Niño Jesús, Instituto de Investigación la Princesa, Madrid, Spain
- CIBEROBN (Centro de Investigación Biomédica en Red sobre Fisiopatología de la Obesidad y Nutrición), Instituto de Salud Carlos III, Madrid, Spain
- Department of Pediatrics, Universidad Autónoma de Madrid, Madrid, Spain
| | - María Soledad Fernández-Alfonso
- Instituto Pluridisciplinar UCM y Departamento de Farmacología, Farmacognosia y Botánica, Facultad de Farmacia, Universidad Complutense, Madrid, Spain
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59
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Bombassaro B, Ramalho AFS, Fioravante M, Solon C, Nogueira G, Nogueira PAS, Gaspar RS, Ropelle ER, Velloso LA. CD1 is involved in diet-induced hypothalamic inflammation in obesity. Brain Behav Immun 2019; 78:78-90. [PMID: 30660601 DOI: 10.1016/j.bbi.2019.01.011] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/25/2018] [Revised: 12/20/2018] [Accepted: 01/14/2019] [Indexed: 12/18/2022] Open
Abstract
Obesity-associated hypothalamic inflammation plays an important role in the development of defective neuronal control of whole body energy balance. Because dietary fats are the main triggers of hypothalamic inflammation, we hypothesized that CD1, a lipid-presenting protein, may be involved in the hypothalamic inflammatory response in obesity. Here, we show that early after the introduction of a high-fat diet, CD1 expressing cells gradually appear in the mediobasal hypothalamus. The inhibition of hypothalamic CD1 reduces diet-induced hypothalamic inflammation and rescues the obese and glucose-intolerance phenotype of mice fed a high-fat diet. Conversely, the chemical activation of hypothalamic CD1 further increases diet-induced obesity and hypothalamic inflammation. A bioinformatics analysis revealed that hypothalamic CD1 correlates with transcripts encoding for proteins known to be involved in diet-induced hypothalamic abnormalities in obesity. Thus, CD1 is involved in at least part of the hypothalamic inflammatory response in diet-induced obesity and its modulation affects the body mass phenotype of mice.
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Affiliation(s)
- Bruna Bombassaro
- Laboratory of Cell Signaling, University of Campinas, Campinas, São Paulo 13084-970, Brazil
| | - Albina F S Ramalho
- Laboratory of Cell Signaling, University of Campinas, Campinas, São Paulo 13084-970, Brazil
| | - Milena Fioravante
- Laboratory of Cell Signaling, University of Campinas, Campinas, São Paulo 13084-970, Brazil
| | - Carina Solon
- Laboratory of Cell Signaling, University of Campinas, Campinas, São Paulo 13084-970, Brazil
| | - Guilherme Nogueira
- Laboratory of Cell Signaling, University of Campinas, Campinas, São Paulo 13084-970, Brazil
| | - Pedro A S Nogueira
- Laboratory of Cell Signaling, University of Campinas, Campinas, São Paulo 13084-970, Brazil
| | - Rodrigo S Gaspar
- Laboratory of Molecular Biology of Exercise, University of Campinas (UNICAMP), Limeira, São Paulo, Brazil
| | - Eduardo R Ropelle
- Laboratory of Molecular Biology of Exercise, University of Campinas (UNICAMP), Limeira, São Paulo, Brazil
| | - Licio A Velloso
- Laboratory of Cell Signaling, University of Campinas, Campinas, São Paulo 13084-970, Brazil.
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MacDonald AJ, Robb JL, Morrissey NA, Beall C, Ellacott KLJ. Astrocytes in neuroendocrine systems: An overview. J Neuroendocrinol 2019; 31:e12726. [PMID: 31050045 DOI: 10.1111/jne.12726] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/04/2019] [Revised: 04/26/2019] [Accepted: 04/28/2019] [Indexed: 12/11/2022]
Abstract
A class of glial cell, astrocytes, is highly abundant in the central nervous system (CNS). In addition to maintaining tissue homeostasis, astrocytes regulate neuronal communication and synaptic plasticity. There is an ever-increasing appreciation that astrocytes are involved in the regulation of physiology and behaviour in normal and pathological states, including within neuroendocrine systems. Indeed, astrocytes are direct targets of hormone action in the CNS, via receptors expressed on their surface, and are also a source of regulatory neuropeptides, neurotransmitters and gliotransmitters. Furthermore, as part of the neurovascular unit, astrocytes can regulate hormone entry into the CNS. This review is intended to provide an overview of how astrocytes are impacted by and contribute to the regulation of a diverse range of neuroendocrine systems: energy homeostasis and metabolism, reproduction, fluid homeostasis, the stress response and circadian rhythms.
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Affiliation(s)
- Alastair J MacDonald
- Neuroendocrine Research Group, Institute of Biomedical & Clinical Sciences, University of Exeter Medical School, Exeter, UK
| | - Josephine L Robb
- Neuroendocrine Research Group, Institute of Biomedical & Clinical Sciences, University of Exeter Medical School, Exeter, UK
| | - Nicole A Morrissey
- Neuroendocrine Research Group, Institute of Biomedical & Clinical Sciences, University of Exeter Medical School, Exeter, UK
| | - Craig Beall
- Neuroendocrine Research Group, Institute of Biomedical & Clinical Sciences, University of Exeter Medical School, Exeter, UK
| | - Kate L J Ellacott
- Neuroendocrine Research Group, Institute of Biomedical & Clinical Sciences, University of Exeter Medical School, Exeter, UK
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Hypothalamic expression of the atypical chemokine receptor ACKR2 is involved in the systemic regulation of glucose tolerance. Biochim Biophys Acta Mol Basis Dis 2019; 1865:1126-1137. [PMID: 30738810 DOI: 10.1016/j.bbadis.2019.01.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2018] [Revised: 12/06/2018] [Accepted: 01/02/2019] [Indexed: 02/02/2023]
Abstract
In experimental obesity, the hypothalamus is affected by an inflammatory response activated by dietary saturated fats. This inflammation is triggered as early as one day after exposure to a high-fat diet, and during its progression, there is recruitment of inflammatory cells from the systemic circulation. The objective of the present study was identifying chemokines potentially involved in the development of hypothalamic diet-induced inflammation. In order to identify chemokines potentially involved in this process, we performed a real-time PCR array that determined Ackr2 as one of the transcripts undergoing differential regulation in obese-prone as compared to obese-resistant mice fed a high-fat diet for three days. ACKR2 is a decoy receptor that acts as an inhibitor of the signals generated by several CC inflammatory chemokines. Our results show that Ackr2 expression is rapidly induced after exposure to dietary fats both in obese-prone and obese-resistant mice. In immunofluorescence studies, ACKR2 was detected in hypothalamic neurons expressing POMC and NPY and also in microglia and astrocytes. The lentiviral overexpression of ACKR2 in the hypothalamus reduced diet-induced hypothalamic inflammation; however, there was no change in spontaneous caloric intake and body mass. Nevertheless, the overexpression of ACKR2 resulted in improvement of glucose tolerance, which was accompanied by reduced insulin secretion and increased whole body insulin sensitivity. Thus, ACKR2 is a decoy chemokine receptor expressed in most hypothalamic cells that is modulated by dietary intervention and acts to reduce diet-induced inflammation, leading to improved glucose tolerance due to improved insulin action.
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Weightman Potter PG, Vlachaki Walker JM, Robb JL, Chilton JK, Williamson R, Randall AD, Ellacott KLJ, Beall C. Basal fatty acid oxidation increases after recurrent low glucose in human primary astrocytes. Diabetologia 2019; 62:187-198. [PMID: 30293112 PMCID: PMC6290858 DOI: 10.1007/s00125-018-4744-6] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/30/2018] [Accepted: 08/22/2018] [Indexed: 12/20/2022]
Abstract
AIMS/HYPOTHESIS Hypoglycaemia is a major barrier to good glucose control in type 1 diabetes. Frequent hypoglycaemic episodes impair awareness of subsequent hypoglycaemic bouts. Neural changes underpinning awareness of hypoglycaemia are poorly defined and molecular mechanisms by which glial cells contribute to hypoglycaemia sensing and glucose counterregulation require further investigation. The aim of the current study was to examine whether, and by what mechanism, human primary astrocyte (HPA) function was altered by acute and recurrent low glucose (RLG). METHODS To test whether glia, specifically astrocytes, could detect changes in glucose, we utilised HPA and U373 astrocytoma cells and exposed them to RLG in vitro. This allowed measurement, with high specificity and sensitivity, of RLG-associated changes in cellular metabolism. We examined changes in protein phosphorylation/expression using western blotting. Metabolic function was assessed using a Seahorse extracellular flux analyser. Immunofluorescent imaging was used to examine cell morphology and enzymatic assays were used to measure lactate release, glycogen content, intracellular ATP and nucleotide ratios. RESULTS AMP-activated protein kinase (AMPK) was activated over a pathophysiologically relevant glucose concentration range. RLG produced an increased dependency on fatty acid oxidation for basal mitochondrial metabolism and exhibited hallmarks of mitochondrial stress, including increased proton leak and reduced coupling efficiency. Relative to glucose availability, lactate release increased during low glucose but this was not modified by RLG. Basal glucose uptake was not modified by RLG and glycogen levels were similar in control and RLG-treated cells. Mitochondrial adaptations to RLG were partially recovered by maintaining euglycaemic levels of glucose following RLG exposure. CONCLUSIONS/INTERPRETATION Taken together, these data indicate that HPA mitochondria are altered following RLG, with a metabolic switch towards increased fatty acid oxidation, suggesting glial adaptations to RLG involve altered mitochondrial metabolism that could contribute to defective glucose counterregulation to hypoglycaemia in diabetes.
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Affiliation(s)
- Paul G Weightman Potter
- Institute of Biomedical and Clinical Sciences, University of Exeter Medical School, RILD Building, Barrack Road, Exeter, EX2 5DW, UK
| | - Julia M Vlachaki Walker
- Institute of Biomedical and Clinical Sciences, University of Exeter Medical School, RILD Building, Barrack Road, Exeter, EX2 5DW, UK
| | - Josephine L Robb
- Institute of Biomedical and Clinical Sciences, University of Exeter Medical School, RILD Building, Barrack Road, Exeter, EX2 5DW, UK
| | - John K Chilton
- Institute of Biomedical and Clinical Sciences, University of Exeter Medical School, RILD Building, Barrack Road, Exeter, EX2 5DW, UK
| | - Ritchie Williamson
- School of Pharmacy and Medical Sciences, University of Bradford, Bradford, UK
| | - Andrew D Randall
- Hatherly Laboratories, Prince of Wales Road, University of Exeter, Exeter, UK
| | - Kate L J Ellacott
- Institute of Biomedical and Clinical Sciences, University of Exeter Medical School, RILD Building, Barrack Road, Exeter, EX2 5DW, UK
| | - Craig Beall
- Institute of Biomedical and Clinical Sciences, University of Exeter Medical School, RILD Building, Barrack Road, Exeter, EX2 5DW, UK.
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63
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Role of astrocytes, microglia, and tanycytes in brain control of systemic metabolism. Nat Neurosci 2018; 22:7-14. [PMID: 30531847 DOI: 10.1038/s41593-018-0286-y] [Citation(s) in RCA: 166] [Impact Index Per Article: 27.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2018] [Accepted: 11/06/2018] [Indexed: 12/28/2022]
Abstract
Astrocytes, microglia, and tanycytes play active roles in the regulation of hypothalamic feeding circuits. These non-neuronal cells are crucial in determining the functional interactions of specific neuronal subpopulations involved in the control of metabolism. Recent advances in biology, optics, genetics, and pharmacology have resulted in the emergence of novel and highly sophisticated approaches for studying hypothalamic neuronal-glial networks. Here we summarize the progress in the field and argue that glial-neuronal interactions provide a core hub integrating food-related cues, interoceptive signals, and internal states to adapt a complex set of physiological responses operating on different timescales to finely tune behavior and metabolism according to metabolic status. This expanding knowledge helps to redefine our understanding of the physiology of food intake and energy metabolism.
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64
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Santos CL, Bobermin LD, Souza DO, Quincozes-Santos A. Leptin stimulates the release of pro-inflammatory cytokines in hypothalamic astrocyte cultures from adult and aged rats. Metab Brain Dis 2018; 33:2059-2063. [PMID: 30229384 DOI: 10.1007/s11011-018-0311-6] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/17/2018] [Accepted: 09/12/2018] [Indexed: 01/06/2023]
Abstract
Leptin is an adipose tissue-derived hormone that acts on the hypothalamus in order to maintain energy homeostasis. However, leptin can also induce an inflammatory response. Increasing evidence has highlighted a critical role of astrocytes in the effects of leptin on the hypothalamus. In addition, astrocytes participate in neuroinflammation by producing and releasing a wide range of inflammatory mediators. In this study, we aimed to investigate the age-dependent effect of leptin on pro- and anti-inflammatory cytokines released by the hypothalamic astrocyte cultures obtained from newborn, adult, and aged Wistar rats. In hypothalamic astrocytes from newborn rats, leptin did not change the release of pro-inflammatory cytokines, tumor necrosis factor α (TNF-α) and interleukin 1β (IL-1β). On the other contrary, leptin increased the release of both TNF-α and IL-1β in astrocyte cultures from adult and aged animals. Regarding the anti-inflammatory cytokine interleukin 10 (IL-10), we did not observe any change in response to leptin. In conclusion, our data suggests a pro-inflammatory action of leptin on the hypothalamus during aging. This in turn may be related to the triggering of metabolic disorders, as both of these conditions are associated with neuroinflammation.
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Affiliation(s)
- Camila Leite Santos
- Programa de Pós-Graduação em Ciências Biológicas: Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Larissa Daniele Bobermin
- Programa de Pós-Graduação em Ciências Biológicas: Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Diogo Onofre Souza
- Programa de Pós-Graduação em Ciências Biológicas: Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
- Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - André Quincozes-Santos
- Programa de Pós-Graduação em Ciências Biológicas: Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil.
- Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil.
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65
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Pedroso AP, Dornellas APS, de Souza AP, Pagotto JF, Oyama LM, Nascimento CMO, Klawitter J, Christians U, Tashima AK, Ribeiro EB. A proteomics-metabolomics approach indicates changes in hypothalamic glutamate-GABA metabolism of adult female rats submitted to intrauterine growth restriction. Eur J Nutr 2018; 58:3059-3068. [PMID: 30406389 PMCID: PMC6842332 DOI: 10.1007/s00394-018-1851-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2018] [Accepted: 10/29/2018] [Indexed: 12/18/2022]
Abstract
PURPOSE Intrauterine growth restriction (IUGR) has been shown to induce the programming of metabolic disturbances and obesity, associated with hypothalamic derangements. The present study aimed at investigating the effects of IUGR on the protein and metabolite profiles of the hypothalamus of adult female rats. METHODS Wistar rats were mated and either had ad libitum access to food (control group) or received only 50% of the control intake (restricted group) during the whole pregnancy. Both groups ate ad libitum throughout lactation. At 4 months of age, the control and restricted female offspring was euthanized for blood and tissues collection. The hypothalami were processed for data independent acquisition mass spectrometry-based proteomics or targeted mass spectrometry-based metabolomics. RESULTS The adult females submitted to IUGR showed increased glycemia and body adiposity, with normal body weight and food intake. IUGR modulated significantly 28 hypothalamic proteins and 7 hypothalamic metabolites. The effects of IUGR on hypothalamic proteins and metabolites included downregulation of glutamine synthetase, glutamate decarboxylase, glutamate dehydrogenase, isocitrate dehydrogenase, α-ketoglutarate, and up-regulation of NADH dehydrogenase and phosphoenolpyruvate. Integrated pathway analysis indicated that IUGR affected GABAergic synapse, glutamate metabolism, and TCA cycle, highly interconnected pathways whose derangement has potentially multiple consequences. CONCLUSION The present findings suggested that the effects of IUGR on GABA/glutamate-glutamine cycle may be involved in the programming of obesity and hyperglycemia in female rats.
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Affiliation(s)
- Amanda P Pedroso
- Departamento de Fisiologia, Universidade Federal de São Paulo, Escola Paulista de Medicina, Rua Botucatu 862, Vila Clementino, São Paulo, SP, 04023-062, Brazil
| | - Ana P S Dornellas
- Departamento de Fisiologia, Universidade Federal de São Paulo, Escola Paulista de Medicina, Rua Botucatu 862, Vila Clementino, São Paulo, SP, 04023-062, Brazil
| | - Adriana P de Souza
- Departamento de Fisiologia, Universidade Federal de São Paulo, Escola Paulista de Medicina, Rua Botucatu 862, Vila Clementino, São Paulo, SP, 04023-062, Brazil
| | - Josias F Pagotto
- Departamento de Bioquímica, Universidade Federal de São Paulo, Escola Paulista de Medicina, São Paulo, SP, Brazil
| | - Lila M Oyama
- Departamento de Fisiologia, Universidade Federal de São Paulo, Escola Paulista de Medicina, Rua Botucatu 862, Vila Clementino, São Paulo, SP, 04023-062, Brazil
| | - Cláudia M O Nascimento
- Departamento de Fisiologia, Universidade Federal de São Paulo, Escola Paulista de Medicina, Rua Botucatu 862, Vila Clementino, São Paulo, SP, 04023-062, Brazil
| | - Jelena Klawitter
- iC42 Clinical Research and Development, Department of Anesthesiology, University of Colorado Denver, Anschutz Medical Campus, Aurora, CO, USA
| | - Uwe Christians
- iC42 Clinical Research and Development, Department of Anesthesiology, University of Colorado Denver, Anschutz Medical Campus, Aurora, CO, USA
| | - Alexandre K Tashima
- Departamento de Bioquímica, Universidade Federal de São Paulo, Escola Paulista de Medicina, São Paulo, SP, Brazil
| | - Eliane Beraldi Ribeiro
- Departamento de Fisiologia, Universidade Federal de São Paulo, Escola Paulista de Medicina, Rua Botucatu 862, Vila Clementino, São Paulo, SP, 04023-062, Brazil.
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Zatkova M, Bacova Z, Puerta F, Lestanova Z, Alanazi M, Kiss A, Reichova A, Castejon AM, Ostatnikova D, Bakos J. Projection length stimulated by oxytocin is modulated by the inhibition of calcium signaling in U-87MG cells. J Neural Transm (Vienna) 2018; 125:1847-1856. [DOI: 10.1007/s00702-018-1933-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2018] [Accepted: 09/21/2018] [Indexed: 12/12/2022]
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Abstract
Astrocytes have historically been considered structural supporting cells for neurons. Thanks to new molecular tools, allowing specific cell ablation or over-expression of genes, new unexpected astrocytic functions have recently been unveiled. This review focus on emerging groundbreaking findings showing that hypothalamic astrocytes are pivotal for the regulation of whole body energy homeostasis. Hypothalamic astrocytes sense glucose and fatty acids, and express receptors for several peripheral hormones such as leptin and insulin. Furthermore, they display striking sexual dimorphism which may account, at least partially, for gender specific differences in energy homeostasis. Metabolic alterations have been shown to influence the initiation and progression of many neurodegenerative disorders. A better understanding of the roles and interplay between the different brain cells in regulating energy homeostasis could help develop new therapeutic strategies to prevent or cure neurodegenerative disorders.
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Affiliation(s)
- Simonetta Camandola
- Laboratory of Neurosciences, National Institute on Aging, Intramural Research Program, Baltimore, MD, USA
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68
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Neurobiological characteristics underlying metabolic differences between males and females. Prog Neurobiol 2018; 176:18-32. [PMID: 30194984 DOI: 10.1016/j.pneurobio.2018.09.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2018] [Revised: 08/22/2018] [Accepted: 09/01/2018] [Indexed: 12/24/2022]
Abstract
The hypothalamus is the main integrating center for metabolic control. Our understanding of how hypothalamic circuits function to control appetite and energy expenditure has increased dramatically in recent years, due to the rapid rise in the incidence of obesity and the search for effective treatments. Increasing evidence indicates that these treatments will most likely differ between males and females. Indeed, sex differences in metabolism have been demonstrated at various levels, including in two of the most studied neuronal populations involved in metabolic control: the anorexigenic proopiomelanocortin neurons and the orexigenic neuropeptide Y/Agouti-related protein neurons. Here we review what is known to date regarding the sex differences in these two neuronal populations, as well as other neuronal populations involved in metabolic control and glial cells.
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69
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Rai A, Mishra R, Ganesh S. Suppression of leptin signaling reduces polyglucosan inclusions and seizure susceptibility in a mouse model for Lafora disease. Hum Mol Genet 2018; 26:4778-4785. [PMID: 28973665 DOI: 10.1093/hmg/ddx357] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2017] [Accepted: 09/12/2017] [Indexed: 01/10/2023] Open
Abstract
Lafora disease (LD) represents a fatal form of neurodegenerative disorder characterized by the presence of abnormally large number of polyglucosan bodies-called the Lafora bodies-in neurons and other tissues of the affected patients. The disease is caused by defects in the EPM2A gene coding for a protein phosphatase (laforin) or the NHLRC1 gene coding for an ubiquitin ligase (malin). Studies have shown that inhibition of glycogen synthesis in the brain could prevent the formation of Lafora bodies in the neurons and reduce seizure susceptibility in laforin-deficient mouse, an established animal model for LD. Since increased glucose uptake is thought to underlie increased glycogen in LD, and since the adipocyte hormone leptin is known to positively regulate the glucose uptake in neurons, we reasoned that blocking leptin signaling might reduce the neuronal glucose uptake and ameliorate the LD pathology. We demonstrate here that mice that were deficient for both laforin and leptin receptor showed a reduction in the glycogen level, Lafora bodies and gliosis in the brain, and displayed reduced susceptibility to induced seizures as compared to animals that were deficient only for laforin. Thus, blocking leptin signaling could be a one of the effective therapeutic strategies in LD.
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Affiliation(s)
- Anupama Rai
- Department of Biological Sciences and Bioengineering, Indian Institute of Technology, Kanpur 208016, India
| | - Rohit Mishra
- Department of Biological Sciences and Bioengineering, Indian Institute of Technology, Kanpur 208016, India
| | - Subramaniam Ganesh
- Department of Biological Sciences and Bioengineering, Indian Institute of Technology, Kanpur 208016, India
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70
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Hypothalamic inflammation and malfunctioning glia in the pathophysiology of obesity and diabetes: Translational significance. Biochem Pharmacol 2018; 153:123-133. [DOI: 10.1016/j.bcp.2018.01.024] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2017] [Accepted: 01/09/2018] [Indexed: 12/25/2022]
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71
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Endocannabinoids in Body Weight Control. Pharmaceuticals (Basel) 2018; 11:ph11020055. [PMID: 29849009 PMCID: PMC6027162 DOI: 10.3390/ph11020055] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2018] [Revised: 05/17/2018] [Accepted: 05/28/2018] [Indexed: 12/15/2022] Open
Abstract
Maintenance of body weight is fundamental to maintain one's health and to promote longevity. Nevertheless, it appears that the global obesity epidemic is still constantly increasing. Endocannabinoids (eCBs) are lipid messengers that are involved in overall body weight control by interfering with manifold central and peripheral regulatory circuits that orchestrate energy homeostasis. Initially, blocking of eCB signaling by first generation cannabinoid type 1 receptor (CB1) inverse agonists such as rimonabant revealed body weight-reducing effects in laboratory animals and men. Unfortunately, rimonabant also induced severe psychiatric side effects. At this point, it became clear that future cannabinoid research has to decipher more precisely the underlying central and peripheral mechanisms behind eCB-driven control of feeding behavior and whole body energy metabolism. Here, we will summarize the most recent advances in understanding how central eCBs interfere with circuits in the brain that control food intake and energy expenditure. Next, we will focus on how peripheral eCBs affect food digestion, nutrient transformation and energy expenditure by interfering with signaling cascades in the gastrointestinal tract, liver, pancreas, fat depots and endocrine glands. To finally outline the safe future potential of cannabinoids as medicines, our overall goal is to address the molecular, cellular and pharmacological logic behind central and peripheral eCB-mediated body weight control, and to figure out how these precise mechanistic insights are currently transferred into the development of next generation cannabinoid medicines displaying clearly improved safety profiles, such as significantly reduced side effects.
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Yasumoto Y, Miyazaki H, Ogata M, Kagawa Y, Yamamoto Y, Islam A, Yamada T, Katagiri H, Owada Y. Glial Fatty Acid-Binding Protein 7 (FABP7) Regulates Neuronal Leptin Sensitivity in the Hypothalamic Arcuate Nucleus. Mol Neurobiol 2018; 55:9016-9028. [PMID: 29623545 DOI: 10.1007/s12035-018-1033-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2017] [Accepted: 03/23/2018] [Indexed: 10/17/2022]
Abstract
The hypothalamus is involved in the regulation of food intake and energy homeostasis. The arcuate nucleus (ARC) and median eminence (ME) are the primary hypothalamic sites that sense leptin and nutrients in the blood, thereby mediating food intake. Recently, studies demonstrating a role for non-neuronal cell types, including astrocytes and tanycytes, in these regulatory processes have begun to emerge. However, the molecular mechanisms involved in these activities remain largely unknown. In this study, we examined in detail the localization of fatty acid-binding protein 7 (FABP7) in the hypothalamic ARC and sought to determine its role in the hypothalamus. We performed a phenotypic analysis of diet-induced FABP7 knockout (KO) obese mice and of FABP7 KO mice treated with a single leptin injection. Immunohistochemistry revealed that FABP7+ cells are NG2+ or GFAP+ in the ARC and ME. In mice fed a high-fat diet, weight gain and food intake were lower in FABP7 KO mice than in wild-type (WT) mice. FABP7 KO mice also had lower food intake and weight gain after a single injection of leptin, and we consistently confirmed that the number of pSTAT3+ cells in the ARC indicated that the leptin-induced activation of neurons was significantly more frequent in FABP7 KO mice than in WT mice. In FABP7 KO mice-derived primary astrocyte cultures, the level of ERK phosphorylation was lower after leptin treatment. Collectively, these results indicate that in hypothalamic astrocytes, FABP7 might be involved in sensing neuronal leptin via glia-mediated mechanisms and plays a pivotal role in controlling systemic energy homeostasis.
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Affiliation(s)
- Yuki Yasumoto
- Department of Organ Anatomy, Tohoku University Graduate School of Medicine, 2-1, Seiryo-machi, Aoba-ku, Sendai, Miyagi, 980-8575, Japan.
| | - Hirofumi Miyazaki
- Department of Organ Anatomy, Tohoku University Graduate School of Medicine, 2-1, Seiryo-machi, Aoba-ku, Sendai, Miyagi, 980-8575, Japan
| | - Masaki Ogata
- Department of Organ Anatomy, Tohoku University Graduate School of Medicine, 2-1, Seiryo-machi, Aoba-ku, Sendai, Miyagi, 980-8575, Japan
| | - Yoshiteru Kagawa
- Department of Organ Anatomy, Tohoku University Graduate School of Medicine, 2-1, Seiryo-machi, Aoba-ku, Sendai, Miyagi, 980-8575, Japan
| | - Yui Yamamoto
- Department of Organ Anatomy, Tohoku University Graduate School of Medicine, 2-1, Seiryo-machi, Aoba-ku, Sendai, Miyagi, 980-8575, Japan
| | - Ariful Islam
- Department of Organ Anatomy, Tohoku University Graduate School of Medicine, 2-1, Seiryo-machi, Aoba-ku, Sendai, Miyagi, 980-8575, Japan
| | - Tetsuya Yamada
- Department of Metabolism and Diabetes, Tohoku University Graduate School of Medicine, 2-1, Seiryo-machi, Aoba-ku, Sendai, Miyagi, 980-8575, Japan
| | - Hideki Katagiri
- Department of Metabolism and Diabetes, Tohoku University Graduate School of Medicine, 2-1, Seiryo-machi, Aoba-ku, Sendai, Miyagi, 980-8575, Japan
| | - Yuji Owada
- Department of Organ Anatomy, Tohoku University Graduate School of Medicine, 2-1, Seiryo-machi, Aoba-ku, Sendai, Miyagi, 980-8575, Japan.
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Pfuhlmann K, Schriever SC, Legutko B, Baumann P, Harrison L, Kabra DG, Baumgart EV, Tschöp MH, Garcia-Caceres C, Pfluger PT. Calcineurin A beta deficiency ameliorates HFD-induced hypothalamic astrocytosis in mice. J Neuroinflammation 2018; 15:35. [PMID: 29422055 PMCID: PMC5806488 DOI: 10.1186/s12974-018-1076-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2017] [Accepted: 01/22/2018] [Indexed: 11/16/2022] Open
Abstract
Astrocytosis is a reactive process involving cellular, molecular, and functional changes to facilitate neuronal survival, myelin preservation, blood brain barrier function and protective glial scar formation upon brain insult. The overall pro- or anti-inflammatory impact of reactive astrocytes appears to be driven in a context- and disease-driven manner by modulation of astrocytic Ca2+ homeostasis and activation of Ca2+/calmodulin-activated serine/threonine phosphatase calcineurin. Here, we aimed to assess whether calcineurin is dispensable for astrocytosis in the hypothalamus driven by prolonged high fat diet (HFD) feeding. Global deletion of calcineurin A beta (gene name: Ppp3cb) led to a decrease of glial fibrillary acidic protein (GFAP)-positive cells in the ventromedial hypothalamus (VMH), dorsomedial hypothalamus (DMH), and arcuate nucleus (ARC) of mice exposed chronically to HFD. The concomitant decrease in Iba1-positive microglia in the VMH further suggests a modest impact of Ppp3cb deletion on microgliosis. Pharmacological inhibition of calcineurin activity by Fk506 had no impact on IBA1-positive microglia in hypothalami of mice acutely exposed to HFD for 1 week. However, Fk506-treated mice displayed a decrease in GFAP levels in the ARC. In vivo effects could not be replicated in cell culture, where calcineurin inhibition by Fk506 had no effect on astrocytic morphology, astrocytic cell death, GFAP, and vimentin protein levels or microglia numbers in primary hypothalamic astrocytes and microglia co-cultures. Further, adenoviral overexpression of calcineurin subunit Ppp3r1 in primary glia culture did not lead to an increase in GFAP fluorescence intensity. Overall, our results point to a prominent role of calcineurin in mediating hypothalamic astrocytosis as response to acute and chronic HFD exposure. Moreover, discrepant findings in vivo and in cell culture indicate the necessity of studying astrocytes in their “natural” environment, i.e., preserving an intact hypothalamic microenvironment with neurons and non-neuronal cells in close proximity.
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Affiliation(s)
- Katrin Pfuhlmann
- Research Unit NeuroBiology of Diabetes, Helmholtz Diabetes Center, Helmholtz Zentrum München, 85764, Neuherberg, Germany.,Institute for Diabetes and Obesity, Helmholtz Diabetes Center, Helmholtz Zentrum München, 85764, Neuherberg, Germany.,Division of Metabolic Diseases, Technische Universität München, 80333, Munich, Germany.,German Center for Diabetes Research (DZD), 85764, Neuherberg, Germany
| | - Sonja C Schriever
- Research Unit NeuroBiology of Diabetes, Helmholtz Diabetes Center, Helmholtz Zentrum München, 85764, Neuherberg, Germany.,Institute for Diabetes and Obesity, Helmholtz Diabetes Center, Helmholtz Zentrum München, 85764, Neuherberg, Germany
| | - Beata Legutko
- Institute for Diabetes and Obesity, Helmholtz Diabetes Center, Helmholtz Zentrum München, 85764, Neuherberg, Germany.,Division of Metabolic Diseases, Technische Universität München, 80333, Munich, Germany.,German Center for Diabetes Research (DZD), 85764, Neuherberg, Germany
| | - Peter Baumann
- Research Unit NeuroBiology of Diabetes, Helmholtz Diabetes Center, Helmholtz Zentrum München, 85764, Neuherberg, Germany.,Institute for Diabetes and Obesity, Helmholtz Diabetes Center, Helmholtz Zentrum München, 85764, Neuherberg, Germany.,Division of Metabolic Diseases, Technische Universität München, 80333, Munich, Germany.,German Center for Diabetes Research (DZD), 85764, Neuherberg, Germany
| | - Luke Harrison
- Research Unit NeuroBiology of Diabetes, Helmholtz Diabetes Center, Helmholtz Zentrum München, 85764, Neuherberg, Germany.,Institute for Diabetes and Obesity, Helmholtz Diabetes Center, Helmholtz Zentrum München, 85764, Neuherberg, Germany.,Division of Metabolic Diseases, Technische Universität München, 80333, Munich, Germany.,German Center for Diabetes Research (DZD), 85764, Neuherberg, Germany
| | - Dhiraj G Kabra
- German Center for Diabetes Research (DZD), 85764, Neuherberg, Germany.,Institute for Clinical Biochemistry and Pathobiochemistry, German Diabetes Center. Heinrich Heine University, Leibniz Center for Diabetes Research, 40225, Düsseldorf, Germany
| | - Emily Violette Baumgart
- Research Unit NeuroBiology of Diabetes, Helmholtz Diabetes Center, Helmholtz Zentrum München, 85764, Neuherberg, Germany.,Institute for Diabetes and Obesity, Helmholtz Diabetes Center, Helmholtz Zentrum München, 85764, Neuherberg, Germany.,German Center for Diabetes Research (DZD), 85764, Neuherberg, Germany
| | - Matthias H Tschöp
- Institute for Diabetes and Obesity, Helmholtz Diabetes Center, Helmholtz Zentrum München, 85764, Neuherberg, Germany.,Division of Metabolic Diseases, Technische Universität München, 80333, Munich, Germany.,German Center for Diabetes Research (DZD), 85764, Neuherberg, Germany
| | - Cristina Garcia-Caceres
- Institute for Diabetes and Obesity, Helmholtz Diabetes Center, Helmholtz Zentrum München, 85764, Neuherberg, Germany. .,German Center for Diabetes Research (DZD), 85764, Neuherberg, Germany.
| | - Paul T Pfluger
- Research Unit NeuroBiology of Diabetes, Helmholtz Diabetes Center, Helmholtz Zentrum München, 85764, Neuherberg, Germany. .,Institute for Diabetes and Obesity, Helmholtz Diabetes Center, Helmholtz Zentrum München, 85764, Neuherberg, Germany. .,German Center for Diabetes Research (DZD), 85764, Neuherberg, Germany.
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Yuan X, Caron A, Wu H, Gautron L. Leptin Receptor Expression in Mouse Intracranial Perivascular Cells. Front Neuroanat 2018; 12:4. [PMID: 29410615 PMCID: PMC5787097 DOI: 10.3389/fnana.2018.00004] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2017] [Accepted: 01/08/2018] [Indexed: 12/28/2022] Open
Abstract
Past studies have suggested that non-neuronal brain cells express the leptin receptor. However, the identity and distribution of these leptin receptor-expressing non-neuronal brain cells remain debated. This study assessed the distribution of the long form of the leptin receptor (LepRb) in non-neuronal brain cells using a reporter mouse model in which LepRb-expressing cells are permanently marked by tdTomato fluorescent protein (LepRb-CretdTomato). Double immunohistochemistry revealed that, in agreement with the literature, the vast majority of tdTomato-tagged cells across the mouse brain were neurons (i.e., based on immunoreactivity for NeuN). Non-neuronal structures also contained tdTomato-positive cells, including the choroid plexus and the perivascular space of the meninges and, to a lesser extent, the brain. Based on morphological criteria and immunohistochemistry, perivascular cells were deduced to be mainly pericytes. Notably, tdTomato-positive cells were immunoreactive for vitronectin and platelet derived growth factor receptor beta (PDGFBR). In situ hybridization studies confirmed that most tdTomato-tagged perivascular cells were enriched in leptin receptor mRNA (all isoforms). Using qPCR studies, we confirmed that the mouse meninges were enriched in Leprb and, to a greater extent, the short isoforms of the leptin receptor. Interestingly, qPCR studies further demonstrated significantly altered expression for Vtn and Pdgfrb in the meninges and hypothalamus of LepRb-deficient mice. Collectively, our data demonstrate that the only intracranial non-neuronal cells that express LepRb in the adult mouse are cells that form the blood-brain barrier, including, most notably, meningeal perivascular cells. Our data suggest that pericytic leptin signaling plays a role in the integrity of the intracranial perivascular space and, consequently, may provide a link between obesity and numerous brain diseases.
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Affiliation(s)
- Xuefeng Yuan
- Division of Hypothalamic Research and Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, TX, United States.,Department of Orthopedics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Alexandre Caron
- Division of Hypothalamic Research and Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, TX, United States
| | - Hua Wu
- Department of Orthopedics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Laurent Gautron
- Division of Hypothalamic Research and Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, TX, United States
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Abstract
Astrocytes are neural cells of ectodermal, neuroepithelial origin that provide for homeostasis and defense of the central nervous system (CNS). Astrocytes are highly heterogeneous in morphological appearance; they express a multitude of receptors, channels, and membrane transporters. This complement underlies their remarkable adaptive plasticity that defines the functional maintenance of the CNS in development and aging. Astrocytes are tightly integrated into neural networks and act within the context of neural tissue; astrocytes control homeostasis of the CNS at all levels of organization from molecular to the whole organ.
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Affiliation(s)
- Alexei Verkhratsky
- The University of Manchester , Manchester , United Kingdom ; Achúcarro Basque Center for Neuroscience, IKERBASQUE, Basque Foundation for Science , Bilbao , Spain ; Department of Neuroscience, University of the Basque Country UPV/EHU and CIBERNED, Leioa, Spain ; Center for Basic and Translational Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen , Copenhagen , Denmark ; and Center for Translational Neuromedicine, University of Rochester Medical Center , Rochester, New York
| | - Maiken Nedergaard
- The University of Manchester , Manchester , United Kingdom ; Achúcarro Basque Center for Neuroscience, IKERBASQUE, Basque Foundation for Science , Bilbao , Spain ; Department of Neuroscience, University of the Basque Country UPV/EHU and CIBERNED, Leioa, Spain ; Center for Basic and Translational Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen , Copenhagen , Denmark ; and Center for Translational Neuromedicine, University of Rochester Medical Center , Rochester, New York
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76
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Clasadonte J, Prevot V. The special relationship: glia-neuron interactions in the neuroendocrine hypothalamus. Nat Rev Endocrinol 2018; 14:25-44. [PMID: 29076504 DOI: 10.1038/nrendo.2017.124] [Citation(s) in RCA: 74] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Natural fluctuations in physiological conditions require adaptive responses involving rapid and reversible structural and functional changes in the hypothalamic neuroendocrine circuits that control homeostasis. Here, we discuss the data that implicate hypothalamic glia in the control of hypothalamic neuroendocrine circuits, specifically neuron-glia interactions in the regulation of neurosecretion as well as neuronal excitability. Mechanistically, the morphological plasticity displayed by distal processes of astrocytes, pituicytes and tanycytes modifies the geometry and diffusion properties of the extracellular space. These changes alter the relationship between glial cells of the hypothalamus and adjacent neuronal elements, especially at specialized intersections such as synapses and neurohaemal junctions. The structural alterations in turn lead to functional plasticity that alters the release and spread of neurotransmitters, neuromodulators and gliotransmitters, as well as the activity of discrete glial signalling pathways that mediate feedback by peripheral signals to the hypothalamus. An understanding of the contributions of these and other non-neuronal cell types to hypothalamic neuroendocrine function is thus critical both to understand physiological processes such as puberty, the maintenance of bodily homeostasis and ageing and to develop novel therapeutic strategies for dysfunctions of these processes, such as infertility and metabolic disorders.
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Affiliation(s)
- Jerome Clasadonte
- Inserm, Laboratory of Development and Plasticity of the Neuroendocrine Brain, Jean-Pierre Aubert Research Centre, U1172, Bâtiment Biserte, 1 Place de Verdun, 59045, Lille, Cedex, France
- University of Lille, FHU 1000 days for Health, School of Medicine, Lille 59000, France
| | - Vincent Prevot
- Inserm, Laboratory of Development and Plasticity of the Neuroendocrine Brain, Jean-Pierre Aubert Research Centre, U1172, Bâtiment Biserte, 1 Place de Verdun, 59045, Lille, Cedex, France
- University of Lille, FHU 1000 days for Health, School of Medicine, Lille 59000, France
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77
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Sex differences in the neuroendocrine control of metabolism and the implication of astrocytes. Front Neuroendocrinol 2018; 48:3-12. [PMID: 28552663 DOI: 10.1016/j.yfrne.2017.05.003] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Revised: 05/22/2017] [Accepted: 05/23/2017] [Indexed: 02/07/2023]
Abstract
Males and females have distinct propensities to develop obesity and its related comorbidities, partially due to gonadal steroids. There are sex differences in hypothalamic neuronal circuits, as well as in astrocytes, that participate in metabolic control and the development of obesity-associated complications. Astrocytes are involved in nutrient transport and metabolism, glucose sensing, synaptic remodeling and modulation of neuronal signaling. They express receptors for metabolic hormones and mediate effects of these metabolic signals on neurons, with astrogliosis occurring in response to high fat diet and excess weight gain. However, most studies of obesity have focused on males. Recent reports indicate that male and female astrocytes respond differently to metabolic signals and this could be involved in the differential response to high fat diet and the onset of obesity-associated pathologies. Here we focus on the sex differences in response to obesogenic paradigms and the possible role of hypothalamic astrocytes in this phenomenon.
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78
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Zhou YD. Glial Regulation of Energy Metabolism. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2018; 1090:105-121. [DOI: 10.1007/978-981-13-1286-1_6] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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79
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Verkhratsky A, Nedergaard M. Physiology of Astroglia. Physiol Rev 2018; 98:239-389. [PMID: 29351512 PMCID: PMC6050349 DOI: 10.1152/physrev.00042.2016] [Citation(s) in RCA: 951] [Impact Index Per Article: 158.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2016] [Revised: 03/22/2017] [Accepted: 04/27/2017] [Indexed: 02/07/2023] Open
Abstract
Astrocytes are neural cells of ectodermal, neuroepithelial origin that provide for homeostasis and defense of the central nervous system (CNS). Astrocytes are highly heterogeneous in morphological appearance; they express a multitude of receptors, channels, and membrane transporters. This complement underlies their remarkable adaptive plasticity that defines the functional maintenance of the CNS in development and aging. Astrocytes are tightly integrated into neural networks and act within the context of neural tissue; astrocytes control homeostasis of the CNS at all levels of organization from molecular to the whole organ.
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Affiliation(s)
- Alexei Verkhratsky
- The University of Manchester , Manchester , United Kingdom ; Achúcarro Basque Center for Neuroscience, IKERBASQUE, Basque Foundation for Science , Bilbao , Spain ; Department of Neuroscience, University of the Basque Country UPV/EHU and CIBERNED, Leioa, Spain ; Center for Basic and Translational Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen , Copenhagen , Denmark ; and Center for Translational Neuromedicine, University of Rochester Medical Center , Rochester, New York
| | - Maiken Nedergaard
- The University of Manchester , Manchester , United Kingdom ; Achúcarro Basque Center for Neuroscience, IKERBASQUE, Basque Foundation for Science , Bilbao , Spain ; Department of Neuroscience, University of the Basque Country UPV/EHU and CIBERNED, Leioa, Spain ; Center for Basic and Translational Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen , Copenhagen , Denmark ; and Center for Translational Neuromedicine, University of Rochester Medical Center , Rochester, New York
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80
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Argente-Arizón P, Díaz F, Ros P, Barrios V, Tena-Sempere M, García-Segura LM, Argente J, Chowen JA. The Hypothalamic Inflammatory/Gliosis Response to Neonatal Overnutrition Is Sex and Age Dependent. Endocrinology 2018; 159:368-387. [PMID: 29077836 DOI: 10.1210/en.2017-00539] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/07/2017] [Accepted: 10/20/2017] [Indexed: 01/10/2023]
Abstract
Astrocytes participate in both physiological and pathophysiological responses to metabolic and nutrient signals. Although most studies have focused on the astrocytic response to weight gain due to high-fat/high-carbohydrate intake, surplus intake of a balanced diet also induces excess weight gain. We have accessed the effects of neonatal overnutrition, which has both age- and sex-dependent effects on weight gain, on hypothalamic inflammation/gliosis. Although both male and female Wistar rats accumulate excessive fat mass as early as postnatal day (PND) 10 with neonatal overnutrition, no increase in hypothalamic cytokine levels, markers of astrocytes or microglia, or inflammatory signaling pathways were observed. At PND 50, no effect of neonatal overnutriton was found in either sex, whereas at PND 150, males again weighed significantly more than their controls, and this was coincident with an increase in markers of inflammation and astrogliosis in the hypothalamus. Circulating triglycerides and free fatty acids were also elevated in these males, but not in females or in either sex at PND 10. Thus, the effects of fatty acids and estrogens on astrocytes in vitro were analyzed. Our results indicate that changes in circulating fatty acid levels may be involved in the induction of hypothalamic inflammation/gliosis in excess weight gain, even on a normal diet, and that estrogens could participate in the protection of females from these processes. In conclusion, the interaction of developmental influences, dietary composition, age, and sex determines the central inflammatory response and the associated long-term outcomes of excess weight gain.
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Affiliation(s)
- Pilar Argente-Arizón
- Department of Endocrinology, Hospital Infantil Universitario Niño Jesús, Instituto de Investigación la Princesa, Madrid, Spain
- Department of Pediatrics, Facultad de Medicina, Universidad Autónoma de Madrid, Madrid, Spain
- Centro de Investigación Biomédica en Red: Fisiopatología de la Obesidad y Nutrición, Instituto Carlos III, Madrid, Spain
| | - Francisca Díaz
- Department of Endocrinology, Hospital Infantil Universitario Niño Jesús, Instituto de Investigación la Princesa, Madrid, Spain
- Centro de Investigación Biomédica en Red: Fisiopatología de la Obesidad y Nutrición, Instituto Carlos III, Madrid, Spain
| | - Purificación Ros
- Department of Pediatrics, Facultad de Medicina, Universidad Autónoma de Madrid, Madrid, Spain
- Hospital Universitario Puerto de Hierro-Majadahonda, Madrid, Spain
| | - Vicente Barrios
- Department of Endocrinology, Hospital Infantil Universitario Niño Jesús, Instituto de Investigación la Princesa, Madrid, Spain
- Centro de Investigación Biomédica en Red: Fisiopatología de la Obesidad y Nutrición, Instituto Carlos III, Madrid, Spain
| | - Manuel Tena-Sempere
- Centro de Investigación Biomédica en Red: Fisiopatología de la Obesidad y Nutrición, Instituto Carlos III, Madrid, Spain
- Department of Cell Biology, Physiology, and Immunology, University of Córdoba, Instituto Maimónides de Investigación Biomédica de Córdoba, Córdoba, Spain
| | - Luis Miguel García-Segura
- Instituto Cajal, Consejo Superior de Investigaciones Científicas, Centro de Investigación Biomédica en Red de Fragilidad y Envejecimiento Saludable, Instituto Carlos III, Madrid, Spain
| | - Jesús Argente
- Department of Endocrinology, Hospital Infantil Universitario Niño Jesús, Instituto de Investigación la Princesa, Madrid, Spain
- Department of Pediatrics, Facultad de Medicina, Universidad Autónoma de Madrid, Madrid, Spain
- Centro de Investigación Biomédica en Red: Fisiopatología de la Obesidad y Nutrición, Instituto Carlos III, Madrid, Spain
- Instituto Madrileño de Estudios Svanzados Food Institute, Campus de Excelencia Internacional Universidad Autónoma de Madrid + Consejo Superior de Investigaciones Científicas, Madrid, Spain
| | - Julie A Chowen
- Department of Endocrinology, Hospital Infantil Universitario Niño Jesús, Instituto de Investigación la Princesa, Madrid, Spain
- Centro de Investigación Biomédica en Red: Fisiopatología de la Obesidad y Nutrición, Instituto Carlos III, Madrid, Spain
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81
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Argente-Arizón P, Castro-González D, Díaz F, Fernández-Gómez MJ, Sánchez-Garrido MA, Tena-Sempere M, Argente J, Chowen JA. Neonatal Overnutrition Increases Testicular Size and Expression of Luteinizing Hormone β-Subunit in Peripubertal Male Rats. Front Endocrinol (Lausanne) 2018; 9:168. [PMID: 29706935 PMCID: PMC5909034 DOI: 10.3389/fendo.2018.00168] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/05/2017] [Accepted: 03/28/2018] [Indexed: 11/15/2022] Open
Abstract
Proper nutrition is important for growth and development. Maturation of the reproductive axis and the timing of pubertal onset can be delayed when insufficient nutrition is available, or possibly advanced with nutritional abundance. The childhood obesity epidemic has been linked to a secular trend in advanced puberty in some populations. The increase in circulating leptin that occurs in association with obesity has been suggested to act as a signal that an adequate nutritional status exists for puberty to occur, allowing activation of central mechanisms. However, obesity-associated hyperleptinemia is linked to decreased leptin sensitivity, at least in adults. Here, we analyzed whether neonatal overnutrition modifies the response to an increase in leptin in peripubertal male rats, as previously demonstrated in females. Wistar rats were raised in litters of 4 (neonatal overnutrition) or 12 pups (controls) per dam. Leptin was administered sc (3 µg/g body weight) at postnatal day 35 and the rats killed 45 min or 2 h later. Postnatal overfeeding resulted in increased body weight and circulating leptin levels; however, we found no overweight-related changes in the mRNA levels of neuropeptides involved in metabolism or reproduction. In contrast, pituitary expression of luteinizing hormone (LH) beta-subunit was increased in overweight rats, as was testicular weight. There were no basal differences between L4 and L12 males or in their response to leptin administration in pSTAT3 levels in the hypothalamus at either 45 min or 2 h. In contrast, pJAK2 was found to be higher at 45 min in L4 compared to L12 males regardless of leptin treatment, while at 2 h it was higher in L4 leptin-treated males compared to L12 leptin-treated males, as well as L4 vehicle-treated rats. There were no changes in response to leptin administration in the expression of the neuropeptides analyzed. However, serum LH levels rose only in L4 males in response to leptin, but with no change in testosterone levels. In conclusion, the advancement in pubertal onset in males with neonatal overnutrition does not appear to be related to overt modifications in the central response to exogenous leptin during the peripubertal period.
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Affiliation(s)
- Pilar Argente-Arizón
- Department of Endocrinology, Hospital Infantil Universitario Niño Jesús, Madrid, Spain
- Instituto de Investigación La Princesa, Madrid, Spain
- CIBER Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos III, Madrid, Spain
- Department of Pediatrics, Universidad Autónoma de Madrid, Madrid, Spain
| | - David Castro-González
- Department of Endocrinology, Hospital Infantil Universitario Niño Jesús, Madrid, Spain
- Instituto de Investigación La Princesa, Madrid, Spain
- CIBER Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos III, Madrid, Spain
- Department of Pediatrics, Universidad Autónoma de Madrid, Madrid, Spain
| | - Francisca Díaz
- Department of Endocrinology, Hospital Infantil Universitario Niño Jesús, Madrid, Spain
- Instituto de Investigación La Princesa, Madrid, Spain
- CIBER Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos III, Madrid, Spain
| | | | - Miguel A. Sánchez-Garrido
- CIBER Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos III, Madrid, Spain
- Department of Cell Biology, Physiology and Immunology, Instituto Maimónides de Investigacion Biomédicas de Córdoba (IMIBIC), Hospital Universitario Reina Sofia, University of Córdoba, Córdoba, Spain
| | - Manuel Tena-Sempere
- CIBER Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos III, Madrid, Spain
- Department of Cell Biology, Physiology and Immunology, Instituto Maimónides de Investigacion Biomédicas de Córdoba (IMIBIC), Hospital Universitario Reina Sofia, University of Córdoba, Córdoba, Spain
| | - Jesús Argente
- Department of Endocrinology, Hospital Infantil Universitario Niño Jesús, Madrid, Spain
- Instituto de Investigación La Princesa, Madrid, Spain
- CIBER Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos III, Madrid, Spain
- Department of Pediatrics, Universidad Autónoma de Madrid, Madrid, Spain
- IMDEA Food Institute, CEI UAM-CSIC, Madrid, Spain
- *Correspondence: Jesús Argente, ; Julie A. Chowen,
| | - Julie A. Chowen
- Department of Endocrinology, Hospital Infantil Universitario Niño Jesús, Madrid, Spain
- Instituto de Investigación La Princesa, Madrid, Spain
- CIBER Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos III, Madrid, Spain
- IMDEA Food Institute, CEI UAM-CSIC, Madrid, Spain
- *Correspondence: Jesús Argente, ; Julie A. Chowen,
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82
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Rijnsburger M, Unmehopa UA, Eggels L, Serlie MJ, la Fleur SE. One-week exposure to a free-choice high-fat high-sugar diet does not disrupt blood-brain barrier permeability in fed or overnight fasted rats. Nutr Neurosci 2017; 22:541-550. [PMID: 29284375 DOI: 10.1080/1028415x.2017.1418727] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Objectives: The hypothalamus lies adjacent to the third ventricle and is in close proximity with the median eminence (ME), a circumventricular organ with an incomplete blood-brain barrier (BBB) which controls direct entry of nutrients into the brain. The blood-CSF barrier of the hypothalamus shows dynamic changes upon neuroendocrine events and adjusts permeability with the tight junction (TJ) complex. It has been shown that chronic exposure to a high-fat diet (HFD) affects BBB permeability. HFD also induces leptin resistance and alters neuropeptide expression in the arcuate nucleus (Arc) of the hypothalamus starting early during overnutrition. We hypothesized altered integrity of the BBB to occur after exposing rats to a free-choice high-fat high-sugar (fcHFHS) diet for 1 week. Methods: We measured diffusion of Evans blue dye over the ME and assessed expression of the TJ proteins ZO-1, claudin-5, and occludin in the tanycytic wall of the third ventricle. Furthermore, we assessed protein expression of glucose transporter 1 (GLUT-1), which is highly expressed in the Arc-ME complex and facilitates glucose transport over the BBB. Results: fcHFHS-fed rats increased caloric intake compared to control, however, there was no effect of the fcHFHS diet on permeability of the BBB, nor changes in protein expression of tight TJ proteins or GLUT-1. Fasting acutely affects the BBB and we hypothesized that exposure to the fcHFHS diet affects the BBB differently compared to chow after fasting. We did not, however, find any differences in Evans blue diffusion nor protein expression between chow- and fcHFHS-fed rats when fasted overnight. Conclusions: We conclude that short-term consumption of a fcHFHS diet does not change permeability or diffusion in the hypothalamus barrier in ad libitum fed or fasted rats.
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Affiliation(s)
- M Rijnsburger
- a Department of Endocrinology & Metabolism , Academic Medical Center , Amsterdam , Netherlands.,b Laboratory of Endocrinology, Department of Clinical Chemistry , Academic Medical Center , Amsterdam , Netherlands
| | - U A Unmehopa
- a Department of Endocrinology & Metabolism , Academic Medical Center , Amsterdam , Netherlands.,b Laboratory of Endocrinology, Department of Clinical Chemistry , Academic Medical Center , Amsterdam , Netherlands
| | - L Eggels
- a Department of Endocrinology & Metabolism , Academic Medical Center , Amsterdam , Netherlands.,b Laboratory of Endocrinology, Department of Clinical Chemistry , Academic Medical Center , Amsterdam , Netherlands.,c Metabolism and Reward Group, Royal Netherlands Academy of Arts and Sciences , Netherlands Institute for Neuroscience , Amsterdam , Netherlands
| | - M J Serlie
- a Department of Endocrinology & Metabolism , Academic Medical Center , Amsterdam , Netherlands
| | - S E la Fleur
- a Department of Endocrinology & Metabolism , Academic Medical Center , Amsterdam , Netherlands.,b Laboratory of Endocrinology, Department of Clinical Chemistry , Academic Medical Center , Amsterdam , Netherlands.,c Metabolism and Reward Group, Royal Netherlands Academy of Arts and Sciences , Netherlands Institute for Neuroscience , Amsterdam , Netherlands
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83
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Linehan V, Fang LZ, Hirasawa M. Short-term high-fat diet primes excitatory synapses for long-term depression in orexin neurons. J Physiol 2017; 596:305-316. [PMID: 29143330 DOI: 10.1113/jp275177] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2017] [Accepted: 11/09/2017] [Indexed: 11/08/2022] Open
Abstract
KEY POINTS High-fat diet consumption is a major cause of obesity. Orexin neurons are known to be activated by a high-fat diet and in turn promote further consumption of a high-fat diet. Our study shows that excitatory synapses to orexin neurons become amenable to long-term depression (LTD) after 1 week of high-fat diet feeding. However, this effect reverses after 4 weeks of a high-fat diet. This LTD may be a homeostatic response to a high-fat diet to curb the activity of orexin neurons and hence caloric consumption. Adaptation seen after prolonged high-fat diet intake may contribute to the development of obesity. ABSTRACT Overconsumption of high-fat diets is one of the strongest contributing factors to the rise of obesity rates. Orexin neurons are known to be activated by a palatable high-fat diet and mediate the activation of the mesolimbic reward pathway, resulting in further food intake. While short-term exposure to a high-fat diet is known to induce synaptic plasticity within the mesolimbic pathway, it is unknown if such changes occur in orexin neurons. To investigate this, 3-week-old male rats were fed a palatable high-fat western diet (WD) or control chow for 1 week and then in vitro patch clamp recording was performed. In the WD condition, an activity-dependent long-term depression (LTD) of excitatory synapses was observed in orexin neurons, but not in chow controls. This LTD was presynaptic and depended on postsynaptic metabotropic glutamate receptor 5 (mGluR5) and retrograde endocannabinoid signalling. WD also increased extracellular glutamate levels, suggesting that glutamate spillover and subsequent activation of perisynaptic mGluR5 may occur more readily in the WD condition. In support of this, pharmacological inhibition of glutamate uptake was sufficient to prime chow control synapses to undergo a presynaptic LTD. Interestingly, these WD effects are transient, as extracellular glutamate levels were similar to controls and LTD was no longer observed in orexin neurons after 4 weeks of WD. In summary, excitatory synapses to orexin neurons become amenable to LTD under a palatable high-fat diet, which may represent a homeostatic mechanism to prevent overactivation of these neurons and to curtail high-fat diet consumption.
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Affiliation(s)
- Victoria Linehan
- Division of Biomedical Sciences, Faculty of Medicine, Memorial University, St. John's, NL, Canada, A1B 3V6
| | - Lisa Z Fang
- Division of Biomedical Sciences, Faculty of Medicine, Memorial University, St. John's, NL, Canada, A1B 3V6
| | - Michiru Hirasawa
- Division of Biomedical Sciences, Faculty of Medicine, Memorial University, St. John's, NL, Canada, A1B 3V6
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84
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Frago LM, Canelles S, Freire-Regatillo A, Argente-Arizón P, Barrios V, Argente J, Garcia-Segura LM, Chowen JA. Estradiol Uses Different Mechanisms in Astrocytes from the Hippocampus of Male and Female Rats to Protect against Damage Induced by Palmitic Acid. Front Mol Neurosci 2017; 10:330. [PMID: 29114202 PMCID: PMC5660686 DOI: 10.3389/fnmol.2017.00330] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2017] [Accepted: 09/29/2017] [Indexed: 01/22/2023] Open
Abstract
An excess of saturated fatty acids can be toxic for tissues, including the brain, and this has been associated with the progression of neurodegenerative diseases. Since palmitic acid (PA) is a free fatty acid that is abundant in the diet and circulation and can be harmful, we have investigated the effects of this fatty acid on lipotoxicity in hippocampal astrocytes and the mechanism involved. Moreover, as males and females have different susceptibilities to some neurodegenerative diseases, we accessed the responses of astrocytes from both sexes, as well as the possible involvement of estrogens in the protection against fatty acid toxicity. PA increased endoplasmic reticulum stress leading to cell death in astrocytes from both males and females. Estradiol (E2) increased the levels of protective factors, such as Hsp70 and the anti-inflammatory cytokine interleukin-10, in astrocytes from both sexes. In male astrocytes, E2 decreased pJNK, TNFα, and caspase-3 activation. In contrast, in female astrocytes E2 did not affect the activation of JNK or TNFα levels, but decreased apoptotic cell death. Hence, although E2 exerted protective effects against the detrimental effects of PA, the mechanisms involved appear to be different between male and female astrocytes. This sexually dimorphic difference in the protective mechanisms induced by E2 could be involved in the different susceptibilities of males and females to some neurodegenerative processes.
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Affiliation(s)
- Laura M Frago
- Departamento de Pediatría, Universidad Autónoma de Madrid, Madrid, Spain.,Departamento de Endocrinología, Hospital Infantil Universitario Niño Jesús, Madrid, Spain.,Instituto de Investigación Sanitaria Princesa, Madrid, Spain.,Centro de Investigación Biomédica en Red de Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos III, Madrid, Spain
| | - Sandra Canelles
- Departamento de Endocrinología, Hospital Infantil Universitario Niño Jesús, Madrid, Spain.,Instituto de Investigación Sanitaria Princesa, Madrid, Spain.,Centro de Investigación Biomédica en Red de Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos III, Madrid, Spain
| | - Alejandra Freire-Regatillo
- Departamento de Pediatría, Universidad Autónoma de Madrid, Madrid, Spain.,Departamento de Endocrinología, Hospital Infantil Universitario Niño Jesús, Madrid, Spain.,Instituto de Investigación Sanitaria Princesa, Madrid, Spain.,Centro de Investigación Biomédica en Red de Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos III, Madrid, Spain
| | - Pilar Argente-Arizón
- Departamento de Pediatría, Universidad Autónoma de Madrid, Madrid, Spain.,Departamento de Endocrinología, Hospital Infantil Universitario Niño Jesús, Madrid, Spain.,Instituto de Investigación Sanitaria Princesa, Madrid, Spain.,Centro de Investigación Biomédica en Red de Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos III, Madrid, Spain
| | - Vicente Barrios
- Departamento de Endocrinología, Hospital Infantil Universitario Niño Jesús, Madrid, Spain.,Instituto de Investigación Sanitaria Princesa, Madrid, Spain.,Centro de Investigación Biomédica en Red de Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos III, Madrid, Spain
| | - Jesús Argente
- Departamento de Pediatría, Universidad Autónoma de Madrid, Madrid, Spain.,Departamento de Endocrinología, Hospital Infantil Universitario Niño Jesús, Madrid, Spain.,Instituto de Investigación Sanitaria Princesa, Madrid, Spain.,Centro de Investigación Biomédica en Red de Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos III, Madrid, Spain.,IMDEA Food Institute, Universidad Autónoma de Madrid, Consejo Superior de Investigaciones Científicas (CSIC), Madrid, Spain
| | - Luis M Garcia-Segura
- Instituto Cajal, Consejo Superior de Investigaciones Científicas (CSIC), Madrid, Spain.,CIBER de Investigación Biomédica en Red de Fragilidad y Envejecimiento Saludable (CIBERFES), Instituto de Salud Carlos III, Madrid, Spain
| | - Julie A Chowen
- Departamento de Endocrinología, Hospital Infantil Universitario Niño Jesús, Madrid, Spain.,Instituto de Investigación Sanitaria Princesa, Madrid, Spain.,Centro de Investigación Biomédica en Red de Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos III, Madrid, Spain
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85
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Santos CL, Roppa PHA, Truccolo P, Fontella FU, Souza DO, Bobermin LD, Quincozes-Santos A. Age-Dependent Neurochemical Remodeling of Hypothalamic Astrocytes. Mol Neurobiol 2017; 55:5565-5579. [PMID: 28980158 DOI: 10.1007/s12035-017-0786-x] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2017] [Accepted: 09/21/2017] [Indexed: 01/18/2023]
Abstract
The hypothalamus is a crucial integrative center in the central nervous system, responsible for the regulation of homeostatic activities, including systemic energy balance. Increasing evidence has highlighted a critical role of astrocytes in orchestrating hypothalamic functions; they participate in the modulation of synaptic transmission, metabolic and trophic support to neurons, immune defense, and nutrient sensing. In this context, disturbance of systemic energy homeostasis, which is a common feature of obesity and the aging process, involves inflammatory responses. This may be related to dysfunction of hypothalamic astrocytes. In this regard, the aim of this study was to evaluate the neurochemical properties of hypothalamic astrocyte cultures from newborn, adult, and aged Wistar rats. Age-dependent changes in the regulation of glutamatergic homeostasis, glutathione biosynthesis, amino acid profile, glucose metabolism, trophic support, and inflammatory response were observed. Additionally, signaling pathways including nuclear factor erythroid-derived 2-like 2/heme oxygenase-1 p38 mitogen-activated protein kinase, nuclear factor kappa B, phosphatidylinositide 3-kinase/Akt, and leptin receptor expression may represent putative mechanisms associated with the cellular alterations. In summary, our findings indicate that as age increases, hypothalamic astrocytes remodel and exhibit changes in their neurochemical properties. This process may play a role in the onset and/or progression of metabolic disorders.
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Affiliation(s)
- Camila Leite Santos
- Departamento de Bioquímica, Programa de Pós-Graduação em Ciências Biológicas: Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Rua Ramiro Barcelos, 2600-Anexo, Bairro Santa Cecília, Porto Alegre, RS, 90035-003, Brazil
| | - Paola Haack Amaral Roppa
- Departamento de Bioquímica, Programa de Pós-Graduação em Ciências Biológicas: Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Rua Ramiro Barcelos, 2600-Anexo, Bairro Santa Cecília, Porto Alegre, RS, 90035-003, Brazil
| | - Pedro Truccolo
- Departamento de Bioquímica, Programa de Pós-Graduação em Ciências Biológicas: Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Rua Ramiro Barcelos, 2600-Anexo, Bairro Santa Cecília, Porto Alegre, RS, 90035-003, Brazil
| | - Fernanda Urruth Fontella
- Departamento de Bioquímica, Programa de Pós-Graduação em Ciências Biológicas: Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Rua Ramiro Barcelos, 2600-Anexo, Bairro Santa Cecília, Porto Alegre, RS, 90035-003, Brazil
| | - Diogo Onofre Souza
- Departamento de Bioquímica, Programa de Pós-Graduação em Ciências Biológicas: Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Rua Ramiro Barcelos, 2600-Anexo, Bairro Santa Cecília, Porto Alegre, RS, 90035-003, Brazil
| | - Larissa Daniele Bobermin
- Departamento de Bioquímica, Programa de Pós-Graduação em Ciências Biológicas: Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Rua Ramiro Barcelos, 2600-Anexo, Bairro Santa Cecília, Porto Alegre, RS, 90035-003, Brazil.
| | - André Quincozes-Santos
- Departamento de Bioquímica, Programa de Pós-Graduação em Ciências Biológicas: Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Rua Ramiro Barcelos, 2600-Anexo, Bairro Santa Cecília, Porto Alegre, RS, 90035-003, Brazil.
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86
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Abstract
A hypercaloric diet combined with a sedentary lifestyle is a major risk factor for the development of insulin resistance, type 2 diabetes mellitus (T2DM) and associated comorbidities. Standard treatment for T2DM begins with lifestyle modification, and includes oral medications and insulin therapy to compensate for progressive β-cell failure. However, current pharmaceutical options for T2DM are limited in that they do not maintain stable, durable glucose control without the need for treatment intensification. Furthermore, each medication is associated with adverse effects, which range from hypoglycaemia to weight gain or bone loss. Unexpectedly, fibroblast growth factor 1 (FGF1) and its low mitogenic variants have emerged as potentially safe candidates for restoring euglycaemia, without causing overt adverse effects. In particular, a single peripheral injection of FGF1 can lower glucose to normal levels within hours, without the risk of hypoglycaemia. Similarly, a single intracerebroventricular injection of FGF1 can induce long-lasting remission of the diabetic phenotype. This Review discusses potential mechanisms by which centrally administered FGF1 improves central glucose-sensing and peripheral glucose uptake in a sustained manner. Specifically, we explore the potential crosstalk between FGF1 and glucose-sensing neuronal circuits, hypothalamic neural stem cells and synaptic plasticity. Finally, we highlight therapeutic considerations of FGF1 and compare its metabolic actions with FGF15 (rodents), FGF19 (humans) and FGF21.
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Affiliation(s)
- Emanuel Gasser
- Gene Expression Laboratory, Salk Institute for Biological Studies
| | - Christopher P Moutos
- Gene Expression Laboratory, Salk Institute for Biological Studies
- Howard Hughes Medical Institute, Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, California 92037, USA
- College of Medicine, University of Arkansas for Medical Sciences, 4301 West Markham Street, Little Rock, Arkansas 72205, USA
| | - Michael Downes
- Gene Expression Laboratory, Salk Institute for Biological Studies
| | - Ronald M Evans
- Gene Expression Laboratory, Salk Institute for Biological Studies
- Howard Hughes Medical Institute, Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, California 92037, USA
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87
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Abstract
The hypothalamus is an evolutionarily conserved brain structure that regulates an organism's basic functions, such as homeostasis and reproduction. Several hypothalamic nuclei and neuronal circuits have been the focus of many studies seeking to understand their role in regulating these basic functions. Within the hypothalamic neuronal populations, the arcuate melanocortin system plays a major role in controlling homeostatic functions. The arcuate pro-opiomelanocortin (POMC) neurons in particular have been shown to be critical regulators of metabolism and reproduction because of their projections to several brain areas both in and outside of the hypothalamus, such as autonomic regions of the brain stem and spinal cord. Here, we review and discuss the current understanding of POMC neurons from their development and intracellular regulators to their physiological functions and pathological dysregulation.
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Affiliation(s)
- Chitoku Toda
- Program in Integrative Cell Signaling and Neurobiology of Metabolism, Yale University School of Medicine, New Haven, Connecticut 06520; .,Department of Obstetrics, Gynecology, and Reproductive Sciences, Yale University School of Medicine, New Haven, Connecticut 06520
| | - Anna Santoro
- Program in Integrative Cell Signaling and Neurobiology of Metabolism, Yale University School of Medicine, New Haven, Connecticut 06520; .,Department of Obstetrics, Gynecology, and Reproductive Sciences, Yale University School of Medicine, New Haven, Connecticut 06520
| | - Jung Dae Kim
- Program in Integrative Cell Signaling and Neurobiology of Metabolism, Yale University School of Medicine, New Haven, Connecticut 06520; .,Department of Obstetrics, Gynecology, and Reproductive Sciences, Yale University School of Medicine, New Haven, Connecticut 06520
| | - Sabrina Diano
- Program in Integrative Cell Signaling and Neurobiology of Metabolism, Yale University School of Medicine, New Haven, Connecticut 06520; .,Department of Obstetrics, Gynecology, and Reproductive Sciences, Yale University School of Medicine, New Haven, Connecticut 06520.,Department of Neuroscience, Yale University School of Medicine, New Haven, Connecticut 06520.,Section of Comparative Medicine, Yale University School of Medicine, New Haven, Connecticut 06520
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88
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Drugs to Alter Extracellular Concentration of Glutamate: Modulators of Glutamate Uptake Systems. ACTA ACUST UNITED AC 2017. [DOI: 10.1007/978-1-4939-7228-9_7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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89
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90
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Serra-Juhé C, Martos-Moreno GÁ, Bou de Pieri F, Flores R, González JR, Rodríguez-Santiago B, Argente J, Pérez-Jurado LA. Novel genes involved in severe early-onset obesity revealed by rare copy number and sequence variants. PLoS Genet 2017; 13:e1006657. [PMID: 28489853 PMCID: PMC5443539 DOI: 10.1371/journal.pgen.1006657] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2016] [Revised: 05/24/2017] [Accepted: 02/26/2017] [Indexed: 12/26/2022] Open
Abstract
Obesity is a multifactorial disorder with high heritability (50–75%), which is probably higher in early-onset and severe cases. Although rare monogenic forms and several genes and regions of susceptibility, including copy number variants (CNVs), have been described, the genetic causes underlying the disease still remain largely unknown. We searched for rare CNVs (>100kb in size, altering genes and present in <1/2000 population controls) in 157 Spanish children with non-syndromic early-onset obesity (EOO: body mass index >3 standard deviations above the mean at <3 years of age) using SNP array molecular karyotypes. We then performed case control studies (480 EOO cases/480 non-obese controls) with the validated CNVs and rare sequence variants (RSVs) detected by targeted resequencing of selected CNV genes (n = 14), and also studied the inheritance patterns in available first-degree relatives. A higher burden of gain-type CNVs was detected in EOO cases versus controls (OR = 1.71, p-value = 0.0358). In addition to a gain of the NPY gene in a familial case with EOO and attention deficit hyperactivity disorder, likely pathogenic CNVs included gains of glutamate receptors (GRIK1, GRM7) and the X-linked gastrin-peptide receptor (GRPR), all inherited from obese parents. Putatively functional RSVs absent in controls were also identified in EOO cases at NPY, GRIK1 and GRPR. A patient with a heterozygous deletion disrupting two contiguous and related genes, SLCO4C1 and SLCO6A1, also had a missense RSV at SLCO4C1 on the other allele, suggestive of a recessive model. The genes identified showed a clear enrichment of shared co-expression partners with known genes strongly related to obesity, reinforcing their role in the pathophysiology of the disease. Our data reveal a higher burden of rare CNVs and RSVs in several related genes in patients with EOO compared to controls, and implicate NPY, GRPR, two glutamate receptors and SLCO4C1 in highly penetrant forms of familial obesity. Although there is strong evidence for a high genetic component of obesity, the underlying genetic causes are largely unknown, mostly due to the highly heterogeneous nature of the disorder. In this work, we have focused on the most severe end of the spectrum, severe obesity with early-onset in childhood, which is more likely due to genetic alterations. We screened for rare copy number variation (CNV) a sample of 157 Spanish children with early-onset obesity using molecular karyotypes and then studied the genes altered by CNVs in 480 cases and 480 non-obese controls. We identified a higher burden of gain-type CNVs in cases as well as several CNVs and sequence variants that were specific of the obese population. Interestingly, the genes identified shared co-expression partners with known obesity genes. Among those, the genes encoding the neuropeptide Y (NPY), two glutamate receptors (GRIK1, GRM7), the X-linked gastrin-peptide receptor (GRPR), and the organic anion transporter (SLCO4C1) are novel obesity candidate genes that may contribute to highly penetrant forms of familial obesity.
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Affiliation(s)
- Clara Serra-Juhé
- Genetics Unit, Universitat Pompeu Fabra, Barcelona, Spain
- Hospital del Mar Research Institute (IMIM), Barcelona, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Instituto de Salud Carlos III, Barcelona, Spain
| | - Gabriel Á. Martos-Moreno
- Departments of Pediatrics & Pediatric Endocrinology, Hospital Infantil Universitario Niño Jesús, Universidad Autónoma de Madrid, Madrid, Spain
- Hospital de la Princesa Research Institute, Madrid, Spain
- Centro de Investigación Biomédica en Red de fisiopatología de la obesidad y nutrición (CIBEROBN), Instituto de Salud Carlos III, Madrid, Spain
| | - Francesc Bou de Pieri
- Genetics Unit, Universitat Pompeu Fabra, Barcelona, Spain
- Hospital del Mar Research Institute (IMIM), Barcelona, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Instituto de Salud Carlos III, Barcelona, Spain
| | - Raquel Flores
- Genetics Unit, Universitat Pompeu Fabra, Barcelona, Spain
- Hospital del Mar Research Institute (IMIM), Barcelona, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Instituto de Salud Carlos III, Barcelona, Spain
| | - Juan R. González
- Hospital del Mar Research Institute (IMIM), Barcelona, Spain
- Center for Research in Environmental Epidemiology (CREAL), Barcelona, Spain
- Centro de Investigación Biomédica en Red de Epidemiología y Salud Pública (CIBERESP), Instituto de Salud Carlos III, Barcelona, Spain
| | | | - Jesús Argente
- Departments of Pediatrics & Pediatric Endocrinology, Hospital Infantil Universitario Niño Jesús, Universidad Autónoma de Madrid, Madrid, Spain
- Hospital de la Princesa Research Institute, Madrid, Spain
- Centro de Investigación Biomédica en Red de fisiopatología de la obesidad y nutrición (CIBEROBN), Instituto de Salud Carlos III, Madrid, Spain
- IMDEA Food Institute, CEI UAM & CSIC, Madrid, Spain
- * E-mail: (LAPJ); (JA)
| | - Luis A. Pérez-Jurado
- Genetics Unit, Universitat Pompeu Fabra, Barcelona, Spain
- Hospital del Mar Research Institute (IMIM), Barcelona, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Instituto de Salud Carlos III, Barcelona, Spain
- * E-mail: (LAPJ); (JA)
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91
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Zhang Y, Reichel JM, Han C, Zuniga-Hertz JP, Cai D. Astrocytic Process Plasticity and IKKβ/NF-κB in Central Control of Blood Glucose, Blood Pressure, and Body Weight. Cell Metab 2017; 25:1091-1102.e4. [PMID: 28467927 PMCID: PMC5576872 DOI: 10.1016/j.cmet.2017.04.002] [Citation(s) in RCA: 110] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/21/2016] [Revised: 02/07/2017] [Accepted: 04/05/2017] [Indexed: 10/19/2022]
Abstract
Central regulation of metabolic physiology is mediated critically through neuronal functions; however, whether astrocytes are also essential remains unclear. Here we show that the high-order processes of astrocytes in the mediobasal hypothalamus displayed shortening in fasting and elongation in fed status. Chronic overnutrition and astrocytic IKKβ/NF-κB upregulation similarly impaired astrocytic plasticity, leading to sustained shortening of high-order processes. In physiology, astrocytic IKKβ/NF-κB upregulation resulted in early-onset effects, including glucose intolerance and blood pressure rise, and late-onset effects, including body weight and fat gain. Appropriate inhibition in astrocytic IKKβ/NF-κB protected against chronic overnutrition impairing astrocytic plasticity and these physiological functions. Mechanistically, astrocytic regulation of hypothalamic extracellular GABA level and therefore BDNF expression were found partly accountable. Hence, astrocytic process plasticity and IKKβ/NF-κB play significant roles in central control of blood glucose, blood pressure, and body weight as well as the central induction of these physiological disorders leading to disease.
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Affiliation(s)
- Yalin Zhang
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY 10461, USA; Diabetes Research Center, Albert Einstein College of Medicine, Bronx, NY 10461, USA; Institute of Aging, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Judith M Reichel
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY 10461, USA; Diabetes Research Center, Albert Einstein College of Medicine, Bronx, NY 10461, USA; Institute of Aging, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Cheng Han
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY 10461, USA; Diabetes Research Center, Albert Einstein College of Medicine, Bronx, NY 10461, USA; Institute of Aging, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Juan Pablo Zuniga-Hertz
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY 10461, USA; Diabetes Research Center, Albert Einstein College of Medicine, Bronx, NY 10461, USA; Institute of Aging, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Dongsheng Cai
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY 10461, USA; Diabetes Research Center, Albert Einstein College of Medicine, Bronx, NY 10461, USA; Institute of Aging, Albert Einstein College of Medicine, Bronx, NY 10461, USA.
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92
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Perez-Tilve D. Novel Hypothalamic Mechanisms in the Pathophysiological Control of Body Weight and Metabolism. Endocrinology 2017; 158:1085-1094. [PMID: 28200100 DOI: 10.1210/en.2016-1944] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/17/2016] [Accepted: 02/03/2017] [Indexed: 12/31/2022]
Abstract
The incidence of obesity, with its impact on the development of comorbidities, including diabetes and cardiovascular disease, represents one of the greatest global health threats of the 21st century. This is particularly damning considering the vast progress that has been made in understanding the factors and molecular mechanisms playing a role in the control of energy balance by the central nervous system, especially during the past 3 decades. Despite the wealth of newfound knowledge, effective therapies for prevention of and/or intervention in obesity have not been forthcoming. That said, recent technological advances and the revisiting of previously discarded concepts have identified novel neural mechanisms involved in the control of energy homeostasis, thereby providing potential new targets and experimental approaches that may bring us closer to effective therapies to improve metabolic control. This review summarizes some of the most recent findings, with special emphasis on the role of neural circuits of the hypothalamus.
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Affiliation(s)
- Diego Perez-Tilve
- Department of Internal Medicine, University of Cincinnati College of Medicine, Cincinnati, Ohio 45267
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93
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López M, Tena-Sempere M. Estradiol effects on hypothalamic AMPK and BAT thermogenesis: A gateway for obesity treatment? Pharmacol Ther 2017; 178:109-122. [PMID: 28351720 DOI: 10.1016/j.pharmthera.2017.03.014] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2017] [Accepted: 03/21/2017] [Indexed: 12/24/2022]
Abstract
In addition to their prominent roles in the control of reproduction, estrogens are important modulators of energy balance, as evident in conditions of deficiency of estrogens, which are characterized by increased feeding and decreased energy expenditure, leading to obesity. AMP-activated protein kinase (AMPK) is a ubiquitous cellular energy gauge that is activated under conditions of low energy, increasing energy production and reducing energy wasting. Centrally, the AMPK pathway is a canonical route regulating energy homeostasis, by integrating peripheral signals, such as hormones and metabolites, with neuronal networks. As a result of those actions, hypothalamic AMPK modulates feeding, as well as brown adipose tissue (BAT) thermogenesis and browning of white adipose tissue (WAT). Here, we will review the central actions of estrogens on energy balance, with particular focus on hypothalamic AMPK. The relevance of this interaction is noteworthy, because some agents with known actions on metabolic homeostasis, such as nicotine, metformin, liraglutide, olanzapine and also natural molecules, such as resveratrol and flavonoids, exert their actions by modulating AMPK. This evidence highlights the possibility that hypothalamic AMPK might be a potential target for the treatment of obesity.
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Affiliation(s)
- Miguel López
- Department of Physiology, CIMUS, University of Santiago de Compostela-Instituto de Investigación Sanitaria (IDIS), 15782 Santiago de Compostela, Spain; CIBER Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos II, Spain.
| | - Manuel Tena-Sempere
- CIBER Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos II, Spain; Department of Cell Biology, Physiology and Immunology, University of Córdoba, Spain; Instituto Maimónides de Investigación Biomédica (IMIBIC)/Hospital Reina Sofía, 14004 Córdoba, Spain; FiDiPro Program, Department of Physiology, University of Turku, Kiinamyllynkatu 10, FIN-20520 Turku, Finland.
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94
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Freire-Regatillo A, Argente-Arizón P, Argente J, García-Segura LM, Chowen JA. Non-Neuronal Cells in the Hypothalamic Adaptation to Metabolic Signals. Front Endocrinol (Lausanne) 2017; 8:51. [PMID: 28377744 PMCID: PMC5359311 DOI: 10.3389/fendo.2017.00051] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/05/2017] [Accepted: 03/03/2017] [Indexed: 12/19/2022] Open
Abstract
Although the brain is composed of numerous cell types, neurons have received the vast majority of attention in the attempt to understand how this organ functions. Neurons are indeed fundamental but, in order for them to function correctly, they rely on the surrounding "non-neuronal" cells. These different cell types, which include glia, epithelial cells, pericytes, and endothelia, supply essential substances to neurons, in addition to protecting them from dangerous substances and situations. Moreover, it is now clear that non-neuronal cells can also actively participate in determining neuronal signaling outcomes. Due to the increasing problem of obesity in industrialized countries, investigation of the central control of energy balance has greatly increased in attempts to identify new therapeutic targets. This has led to interesting advances in our understanding of how appetite and systemic metabolism are modulated by non-neuronal cells. For example, not only are nutrients and hormones transported into the brain by non-neuronal cells, but these cells can also metabolize these metabolic factors, thus modifying the signals reaching the neurons. The hypothalamus is the main integrating center of incoming metabolic and hormonal signals and interprets this information in order to control appetite and systemic metabolism. Hence, the factors transported and released from surrounding non-neuronal cells will undoubtedly influence metabolic homeostasis. This review focuses on what is known to date regarding the involvement of different cell types in the transport and metabolism of nutrients and hormones in the hypothalamus. The possible involvement of non-neuronal cells, in particular glial cells, in physiopathological outcomes of poor dietary habits and excess weight gain are also discussed.
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Affiliation(s)
- Alejandra Freire-Regatillo
- Department of Endocrinology, Hospital Infantil Universitario Niño Jesús, Instituto de Investigación la Princesa, Madrid, Spain
- Department of Pediatrics, Facultad de Medicina, Universidad Autónoma de Madrid, Madrid, Spain
- Centro de Investigación Biomédica en Red: Fisiopatología de la Obesidad y Nutrición (CIBEROBN), Madrid, Spain
| | - Pilar Argente-Arizón
- Department of Endocrinology, Hospital Infantil Universitario Niño Jesús, Instituto de Investigación la Princesa, Madrid, Spain
- Department of Pediatrics, Facultad de Medicina, Universidad Autónoma de Madrid, Madrid, Spain
- Centro de Investigación Biomédica en Red: Fisiopatología de la Obesidad y Nutrición (CIBEROBN), Madrid, Spain
| | - Jesús Argente
- Department of Endocrinology, Hospital Infantil Universitario Niño Jesús, Instituto de Investigación la Princesa, Madrid, Spain
- Department of Pediatrics, Facultad de Medicina, Universidad Autónoma de Madrid, Madrid, Spain
- Centro de Investigación Biomédica en Red: Fisiopatología de la Obesidad y Nutrición (CIBEROBN), Madrid, Spain
- IMDEA Food Institute, Campus of International Excellence (CEI) UAM + CSIC, Madrid, Spain
| | - Luis Miguel García-Segura
- Laboratory of Neuroactive Steroids, Department of Functional and Systems Neurobiology, Instituto Cajal, CSIC (Consejo Superior de Investigaciones Científicas), Madrid, Spain
- Centro de Investigación Biomédica en Red de Fragilidad y Envejecimiento Saludable (CIBERFES), Madrid, Spain
| | - Julie A. Chowen
- Department of Endocrinology, Hospital Infantil Universitario Niño Jesús, Instituto de Investigación la Princesa, Madrid, Spain
- Centro de Investigación Biomédica en Red: Fisiopatología de la Obesidad y Nutrición (CIBEROBN), Madrid, Spain
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95
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Frago LM, Chowen JA. Involvement of Astrocytes in Mediating the Central Effects of Ghrelin. Int J Mol Sci 2017; 18:ijms18030536. [PMID: 28257088 PMCID: PMC5372552 DOI: 10.3390/ijms18030536] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2017] [Revised: 02/16/2017] [Accepted: 02/25/2017] [Indexed: 12/31/2022] Open
Abstract
Although astrocytes are the most abundant cells in the mammalian brain, much remains to be learned about their molecular and functional features. Astrocytes express receptors for numerous hormones and metabolic factors, including the appetite-promoting hormone ghrelin. The metabolic effects of ghrelin are largely opposite to those of leptin, as it stimulates food intake and decreases energy expenditure. Ghrelin is also involved in glucose-sensing and glucose homeostasis. The widespread expression of the ghrelin receptor in the central nervous system suggests that this hormone is not only involved in metabolism, but also in other essential functions in the brain. In fact, ghrelin has been shown to promote cell survival and neuroprotection, with some studies exploring the use of ghrelin as a therapeutic agent against metabolic and neurodegenerative diseases. In this review, we highlight the possible role of glial cells as mediators of ghrelin's actions within the brain.
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Affiliation(s)
- Laura M Frago
- Department of Endocrinology, Hospital Infantil Universitario Niño Jesús, Instituto de Investigación la Princesa, CIBER de Obesidad Fisiopatología de la Obesidad y Nutrición (CIBEROBN), Instituto de Salud Carlos III, 28009 Madrid, Spain.
- Department of Pediatrics, Universidad Autónoma de Madrid, 28049 Madrid, Spain.
| | - Julie A Chowen
- Department of Endocrinology, Hospital Infantil Universitario Niño Jesús, Instituto de Investigación la Princesa, CIBER de Obesidad Fisiopatología de la Obesidad y Nutrición (CIBEROBN), Instituto de Salud Carlos III, 28009 Madrid, Spain.
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96
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Affiliation(s)
- Manuel Tena-Sempere
- Instituto Maimónides de Investigación Biomédica (IMIBIC), University of Córdoba and Centro de Investigación Biomédica en Red de Fisiopatología de la Obesidad y Nutrición (CIBEROBN), 14004 Córdoba, Spain
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Douglass JD, Dorfman MD, Thaler JP. Glia: silent partners in energy homeostasis and obesity pathogenesis. Diabetologia 2017; 60:226-236. [PMID: 27986987 PMCID: PMC5253392 DOI: 10.1007/s00125-016-4181-3] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/01/2016] [Accepted: 11/11/2016] [Indexed: 10/20/2022]
Abstract
Body weight stability requires homeostatic regulation to balance energy intake and energy expenditure. Research on this system and how it is affected by obesity has largely focused on the role of hypothalamic neurons as integrators of information about long-term fuel storage, short-term nutrient availability and metabolic demand. Recent studies have uncovered glial cells as additional contributors to energy balance regulation and obesity pathogenesis. Beginning with early work on leptin signalling in astrocytes, this area of research rapidly emerged after the discovery of hypothalamic inflammation and gliosis in obese rodents and humans. Current studies have revealed the involvement of a wide variety of glial cell types in the modulation of neuronal activity, regulation of hormone and nutrient availability, and participation in the physiological regulation of feeding behaviour. In addition, one glial type, microglia, has recently been implicated in susceptibility to diet-induced obesity. Together, these exciting new findings deepen our understanding of energy homeostasis regulation and raise the possibility of identifying novel mechanisms that contribute to the pathogenesis of obesity.
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Affiliation(s)
- John D Douglass
- UW Diabetes Institute and Department of Medicine, University of Washington, 850 Republican St, S248, Box 358055, Seattle, WA, 98109, USA
| | - Mauricio D Dorfman
- UW Diabetes Institute and Department of Medicine, University of Washington, 850 Republican St, S248, Box 358055, Seattle, WA, 98109, USA
| | - Joshua P Thaler
- UW Diabetes Institute and Department of Medicine, University of Washington, 850 Republican St, S248, Box 358055, Seattle, WA, 98109, USA.
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98
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Jensen VFH, Mølck AM, Chapman M, Alifrangis L, Andersen L, Lykkesfeldt J, Bøgh IB. Chronic Hyperinsulinaemic Hypoglycaemia in Rats Is Accompanied by Increased Body Weight, Hyperleptinaemia, and Decreased Neuronal Glucose Transporter Levels in the Brain. Int J Endocrinol 2017; 2017:7861236. [PMID: 28421113 PMCID: PMC5379133 DOI: 10.1155/2017/7861236] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/30/2016] [Revised: 12/19/2016] [Accepted: 12/26/2016] [Indexed: 12/18/2022] Open
Abstract
The brain is vulnerable to hypoglycaemia due to a continuous need of energy substrates to meet its high metabolic demands. Studies have shown that severe acute insulin-induced hypoglycaemia results in oxidative stress in the rat brain, when neuroglycopenia cannot be evaded despite increased levels of cerebral glucose transporters. Compensatory measures in the brain during chronic insulin-induced hypoglycaemia are less well understood. The present study investigated how the brain of nondiabetic rats copes with chronic insulin-induced hypoglycaemia for up to eight weeks. Brain level of different substrate transporters and redox homeostasis was evaluated. Hyperinsulinaemia for 8 weeks consistently lowered blood glucose levels by 30-50% (4-6 mM versus 7-9 mM in controls). The animals had increased food consumption, body weights, and hyperleptinaemia. During infusion, protein levels of the brain neuronal glucose transporter were decreased, whereas levels of lipid peroxidation products were unchanged. Discontinued infusion was followed by transient systemic hyperglycaemia and decreased food consumption and body weight. After 4 weeks, plasma levels of lipid peroxidation products were increased, possibly as a consequence of hyperglycaemia-induced oxidative stress. The present data suggests that chronic moderate hyperinsulinaemic hypoglycaemia causes increased body weight and hyperleptinaemia. This is accompanied by decreased neuronal glucose transporter levels, which may be leptin-induced.
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Affiliation(s)
- Vivi F. H. Jensen
- Department of Veterinary Disease Biology, Section for Experimental Animal Models, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Department of Toxicology, Safety Pharm and Pathology, Novo Nordisk A/S, Maaloev, Denmark
- *Vivi F. H. Jensen:
| | - Anne-Marie Mølck
- Department of Toxicology, Safety Pharm and Pathology, Novo Nordisk A/S, Maaloev, Denmark
| | | | - Lene Alifrangis
- Department of Development DMPK, Novo Nordisk A/S, Maaloev, Denmark
| | - Lene Andersen
- Department of Development Bioanalysis, Novo Nordisk A/S, Maaloev, Denmark
| | - Jens Lykkesfeldt
- Department of Veterinary Disease Biology, Section for Experimental Animal Models, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Ingrid B. Bøgh
- Department of Toxicology, Safety Pharm and Pathology, Novo Nordisk A/S, Maaloev, Denmark
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99
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Argente-Arizón P, Guerra-Cantera S, Garcia-Segura LM, Argente J, Chowen JA. Glial cells and energy balance. J Mol Endocrinol 2017; 58:R59-R71. [PMID: 27864453 DOI: 10.1530/jme-16-0182] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/19/2016] [Accepted: 11/18/2016] [Indexed: 12/31/2022]
Abstract
The search for new strategies and drugs to abate the current obesity epidemic has led to the intensification of research aimed at understanding the neuroendocrine control of appetite and energy expenditure. This intensified investigation of metabolic control has also included the study of how glial cells participate in this process. Glia, the most abundant cell type in the central nervous system, perform a wide spectrum of functions and are vital for the correct functioning of neurons and neuronal circuits. Current evidence indicates that hypothalamic glia, in particular astrocytes, tanycytes and microglia, are involved in both physiological and pathophysiological mechanisms of appetite and metabolic control, at least in part by regulating the signals reaching metabolic neuronal circuits. Glia transport nutrients, hormones and neurotransmitters; they secrete growth factors, hormones, cytokines and gliotransmitters and are a source of neuroprogenitor cells. These functions are regulated, as glia also respond to numerous hormones and nutrients, with the lack of specific hormonal signaling in hypothalamic astrocytes disrupting metabolic homeostasis. Here, we review some of the more recent advances in the role of glial cells in metabolic control, with a special emphasis on the differences between glial cell responses in males and females.
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Affiliation(s)
- Pilar Argente-Arizón
- Departments of Pediatrics & Pediatric EndocrinologyHospital Infantil Universitario Niño Jesús, Instituto de Investigación La Princesa, Department of Pediatrics, Universidad Autónoma de Madrid, CIBEROBN, Instituto de Salud Carlos III, Madrid, Spain
| | - Santiago Guerra-Cantera
- Departments of Pediatrics & Pediatric EndocrinologyHospital Infantil Universitario Niño Jesús, Instituto de Investigación La Princesa, Department of Pediatrics, Universidad Autónoma de Madrid, CIBEROBN, Instituto de Salud Carlos III, Madrid, Spain
| | | | - Jesús Argente
- Departments of Pediatrics & Pediatric EndocrinologyHospital Infantil Universitario Niño Jesús, Instituto de Investigación La Princesa, Department of Pediatrics, Universidad Autónoma de Madrid, CIBEROBN, Instituto de Salud Carlos III, Madrid, Spain
| | - Julie A Chowen
- Departments of Pediatrics & Pediatric EndocrinologyHospital Infantil Universitario Niño Jesús, Instituto de Investigación La Princesa, Department of Pediatrics, Universidad Autónoma de Madrid, CIBEROBN, Instituto de Salud Carlos III, Madrid, Spain
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Lestanova Z, Puerta F, Alanazi M, Bacova Z, Kiss A, Castejon AM, Bakos J. Downregulation of Oxytocin Receptor Decreases the Length of Projections Stimulated by Retinoic Acid in the U-87MG Cells. Neurochem Res 2016; 42:1006-1014. [DOI: 10.1007/s11064-016-2133-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2016] [Revised: 11/03/2016] [Accepted: 12/03/2016] [Indexed: 12/24/2022]
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