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Yagoub S, Chesters RA, Ott J, Zhu J, Cantacorps L, Ritter K, Lippert RN. Acute elevated dietary fat alone is not sufficient to decrease AgRP projections in the paraventricular nucleus of the hypothalamus in mice. Sci Rep 2024; 14:20043. [PMID: 39209992 PMCID: PMC11362280 DOI: 10.1038/s41598-024-70870-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2024] [Accepted: 08/22/2024] [Indexed: 09/04/2024] Open
Abstract
Within the brain, the connections between neurons are constantly changing in response to environmental stimuli. A prime environmental regulator of neuronal activity is diet, and previous work has highlighted changes in hypothalamic connections in response to diets high in dietary fat and elevated sucrose. We sought to determine if the change in hypothalamic neuronal connections was driven primarily by an elevation in dietary fat alone. Analysis was performed in both male and female animals. We measured Agouti-related peptide (AgRP) neuropeptide and Synaptophysin markers in the paraventricular nucleus of the hypothalamus (PVH) in response to an acute 48 h high fat diet challenge. Using two image analysis methods described in previous studies, an effect of a high fat diet on AgRP neuronal projections in the PVH of male or female mice was not identified. These results suggest that it may not be dietary fat alone that is responsible for the previously published alterations in hypothalamic connections. Future work should focus on deciphering the role of individual macronutrients on neuroanatomical and functional changes.
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Affiliation(s)
- Selma Yagoub
- German Institute for Human Nutrition Potsdam-Rehbrücke, Nuthetal, Germany
- University of Potsdam, Potsdam, Germany
| | - Robert A Chesters
- German Institute for Human Nutrition Potsdam-Rehbrücke, Nuthetal, Germany
- NeuroCure Cluster of Excellence, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Jonathan Ott
- German Institute for Human Nutrition Potsdam-Rehbrücke, Nuthetal, Germany
- University of Potsdam, Potsdam, Germany
| | - Jiajie Zhu
- German Institute for Human Nutrition Potsdam-Rehbrücke, Nuthetal, Germany
- University of Potsdam, Potsdam, Germany
- NeuroCure Cluster of Excellence, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Lídia Cantacorps
- German Institute for Human Nutrition Potsdam-Rehbrücke, Nuthetal, Germany
- German Center for Diabetes Research (DZD), Neuherberg, Germany
| | - Katrin Ritter
- German Institute for Human Nutrition Potsdam-Rehbrücke, Nuthetal, Germany
| | - Rachel N Lippert
- German Institute for Human Nutrition Potsdam-Rehbrücke, Nuthetal, Germany.
- German Center for Diabetes Research (DZD), Neuherberg, Germany.
- NeuroCure Cluster of Excellence, Charité - Universitätsmedizin Berlin, Berlin, Germany.
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2
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Naveed M, Smedlund K, Zhou QG, Cai W, Hill JW. Astrocyte involvement in metabolic regulation and disease. Trends Endocrinol Metab 2024:S1043-2760(24)00220-0. [PMID: 39214743 DOI: 10.1016/j.tem.2024.08.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/22/2024] [Revised: 07/30/2024] [Accepted: 08/02/2024] [Indexed: 09/04/2024]
Abstract
Astrocytes, the predominant glial cell type in the mammalian brain, influence a wide variety of brain parameters including neuronal energy metabolism. Exciting recent studies have shown that obesity and diabetes can impact on astrocyte function. We review evidence that dysregulation of astrocytic lipid metabolism and glucose sensing contributes to dysregulation of whole-body energy balance, thermoregulation, and insulin sensitivity. In addition, we consider the overlooked topic of the sex-specific roles of astrocytes and their response to hormonal fluctuations that provide insights into sex differences in metabolic regulation. Finally, we provide an update on potential ways to manipulate astrocyte function, including genetic targeting, optogenetic and chemogenetic techniques, transplantation, and tailored exosome-based therapies, which may lead to improved treatments for metabolic disease.
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Affiliation(s)
- Muhammad Naveed
- Department of Physiology and Pharmacology, School of Medicine and Life Sciences, University of Toledo, Toledo, OH, USA
| | - Kathryn Smedlund
- Department of Physiology and Pharmacology, School of Medicine and Life Sciences, University of Toledo, Toledo, OH, USA
| | - Qi-Gang Zhou
- Department of Clinical Pharmacology, School of Pharmacy, Nanjing Medical University, Nanjing, China
| | - Weikang Cai
- Department of Biomedical Sciences, College of Osteopathic Medicine, New York Institute of Technology, Old Westbury, NY, USA
| | - Jennifer W Hill
- Department of Physiology and Pharmacology, School of Medicine and Life Sciences, University of Toledo, Toledo, OH, USA; Center for Diabetes and Endocrine Research, University of Toledo, Toledo, OH, USA.
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3
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Mendoza-Romero HN, Biddinger JE, Bedenbaugh MN, Simerly RB. Microglia are Required for Developmental Specification of AgRP Innervation in the Hypothalamus of Offspring Exposed to Maternal High Fat Diet During Lactation. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.08.12.607566. [PMID: 39185162 PMCID: PMC11343114 DOI: 10.1101/2024.08.12.607566] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/27/2024]
Abstract
Nutritional fluctuations that occur early in life dictate metabolic adaptations that will affect susceptibility to weight gain and obesity later in life. The postnatal period in mice represents a time of dynamic changes in hypothalamic development and maternal consumption of a high fat diet during the lactation period (MHFD) changes the composition of milk and leads to enhanced susceptibility to obesity in offspring. Agouti-related peptide (AgRP) neurons in the arcuate nucleus of the hypothalamus (ARH) react to changes in multiple metabolic signals and distribute neuroendocrine information to other brain regions, such as the paraventricular hypothalamic nucleus (PVH), which is known to integrate a variety of signals that regulate body weight. Development of neural projections from AgRP neurons to the PVH occurs during the lactation period and these projections are reduced in MHFD offspring, but underlying developmental mechanisms remain largely unknown. Microglia are the resident immune cells of the central nervous system and are involved in refinement of neural connections and modulation of synaptic transmission. Because high fat diet exposure causes activation of microglia in adults, a similar activation may occur in offspring exposed to MHFD and play a role in sculpting hypothalamic feeding circuitry. Genetically targeted axonal labeling and immunohistochemistry were used to visualize AgRP axons and microglia in postnatal mice derived from MHFD dams and morphological changes quantified. The results demonstrate regionally localized changes to microglial morphology in the PVH of MHFD offspring that suggest enhanced surveillance activity and are temporally restricted to the period when AgRP neurons innervate the PVH. In addition, axon labeling experiments confirm a significant decrease in AgRP innervation of the PVH in MHFD offspring and provide direct evidence of synaptic pruning of AgRP inputs to the PVH. Microglial depletion with the Colony-stimulating factor 1 receptor inhibitor PLX5622 determined that the decrease in AgRP innervation observed in MHFD offspring is dependent on microglia, and that microglia are required for weight gain that emerges as early as weaning in offspring of MHFD dams. However, these changes do not appear to be dependent on the degree of microglial mediated synaptic pruning. Together, these findings suggest that microglia are activated by exposure to MHFD and interact directly with AgRP axons during development to permanently alter their density, with implications for developmental programming of metabolic phenotype.
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Affiliation(s)
| | - Jessica E. Biddinger
- Dept of Molecular Physiology & Biophysics, Vanderbilt University, Nashville, TN, 37232, USA
| | - Michelle N. Bedenbaugh
- Dept of Molecular Physiology & Biophysics, Vanderbilt University, Nashville, TN, 37232, USA
| | - Richard B. Simerly
- Dept of Molecular Physiology & Biophysics, Vanderbilt University, Nashville, TN, 37232, USA
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4
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Cutugno G, Kyriakidou E, Nadjar A. Rethinking the role of microglia in obesity. Neuropharmacology 2024; 253:109951. [PMID: 38615749 DOI: 10.1016/j.neuropharm.2024.109951] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2023] [Revised: 04/10/2024] [Accepted: 04/11/2024] [Indexed: 04/16/2024]
Abstract
Microglia are the macrophages of the central nervous system (CNS), implying their role in maintaining brain homeostasis. To achieve this, these cells are sensitive to a plethora of endogenous and exogenous signals, such as neuronal activity, cellular debris, hormones, and pathological patterns, among many others. More recent research suggests that microglia are highly responsive to nutrients and dietary variations. In this context, numerous studies have demonstrated their significant role in the development of obesity under calorie surfeit. Because many reviews already exist on this topic, we have chosen to present the state of our reflections on various concepts put forth in the literature, bringing a new perspective whenever possible. Our literature review focuses on studies conducted in the arcuate nucleus of the hypothalamus, a key structure in the control of food intake. Specifically, we present the recent data available on the modifications of microglial energy metabolism following the consumption of an obesogenic diet and their consequences on hypothalamic neuron activity. We also highlight the studies unraveling the mechanisms underlying obesity-related sexual dimorphism. The review concludes with a list of questions that remain to be addressed in the field to achieve a comprehensive understanding of the role of microglia in the regulation of body energy metabolism. This article is part of the Special Issue on "Microglia".
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Affiliation(s)
- G Cutugno
- University of Bordeaux, INSERM, Neurocentre Magendie, Bordeaux, France
| | - E Kyriakidou
- University of Bordeaux, INSERM, Neurocentre Magendie, Bordeaux, France
| | - A Nadjar
- University of Bordeaux, INSERM, Neurocentre Magendie, Bordeaux, France; Institut Universitaire de France (IUF), France.
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5
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Loganathan N, Lieu CV, Belsham DD. Immortalization and Characterization of GFAP-expressing Glial Cells from the Adult Mouse Hypothalamus, Cortex, and Brain Stem. Neuroscience 2024; 551:43-54. [PMID: 38788830 DOI: 10.1016/j.neuroscience.2024.05.022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2024] [Revised: 04/23/2024] [Accepted: 05/19/2024] [Indexed: 05/26/2024]
Abstract
The generation of astrocyte cell lines from the hypothalamus is key to study glial involvement in hypothalamic physiology, including energy homeostasis. As such, we immortalized astrocytes from the hypothalamus of an adult male CD-1 mouse using SV40 T-antigen to generate the mHypoA-Ast1 cell line. A comparative approach was taken with two other murine GFAP-expressing cell lines that were also generated in this study: a mixed glial cell line from the cortex (mCortA-G1) and an oligodendrocyte cell line from the brainstem (mBstA-Olig1), as well as an established microglial cell line (IMG). mHypoA-Ast1 cells express GFAP, alongside other astrocytic markers such as Aldh1l1, Aqp4, Glt1 and S100b, and express low levels of microglial, ependymal and oligodendrocyte markers. 100 ng/mL lipopolysaccharide (LPS) elevated mRNA levels of Il6, Il1b, Tnfα and Cxcl5 in mHypoA-Ast1 cells after 4 h, while 50 μM palmitate increased Il6 and Chop mRNA, demonstrating the ability of these cells to respond to inflammatory and nutrient signals. Interestingly, co-culture of mHypoA-Ast1 cells with mHypoE-N46 hypothalamic neuronal cells prevented the palmitate-mediated increase in orexigenic neuropeptide Agrp mRNA in mHypoE-N46 cells, suggesting that this cell line can alter neuronal responses to nutrients. In conclusion, we report mHypoA-Ast1 cells representing a functional astrocyte cell line from the adult mouse brain that can be used to study the complex interactions of hypothalamic cells, as well as dysregulation that may occur in disease states, providing a key tool for neuroendocrine research.
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Affiliation(s)
- Neruja Loganathan
- Departments of Physiology, University of Toronto, Toronto, ON, Canada
| | - Calvin V Lieu
- Departments of Physiology, University of Toronto, Toronto, ON, Canada
| | - Denise D Belsham
- Departments of Physiology, University of Toronto, Toronto, ON, Canada; Medicine, University of Toronto, Toronto, ON, Canada.
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6
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Frago LM, Gómez-Romero A, Collado-Pérez R, Argente J, Chowen JA. Synergism Between Hypothalamic Astrocytes and Neurons in Metabolic Control. Physiology (Bethesda) 2024; 39:0. [PMID: 38530221 DOI: 10.1152/physiol.00009.2024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2024] [Revised: 03/05/2024] [Accepted: 03/22/2024] [Indexed: 03/27/2024] Open
Abstract
Astrocytes are no longer considered as passive support cells. In the hypothalamus, these glial cells actively participate in the control of appetite, energy expenditure, and the processes leading to obesity and its secondary complications. Here we briefly review studies supporting this conclusion and the advances made in understanding the underlying mechanisms.
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Affiliation(s)
- Laura M Frago
- Department of Endocrinology, Hospital Infantil Universitario Niño Jesús, Instituto de Investigación La Princesa, Madrid, Spain
- Department of Pediatrics, Faculty of Medicine, Universidad Autónoma de Madrid, Madrid, Spain
- Centro de Investigación Biomédica en Red de Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos III, Madrid, Spain
| | - Alfonso Gómez-Romero
- Department of Endocrinology, Hospital Infantil Universitario Niño Jesús, Instituto de Investigación La Princesa, Madrid, Spain
- Department of Pediatrics, Faculty of Medicine, Universidad Autónoma de Madrid, Madrid, Spain
| | - Roberto Collado-Pérez
- Department of Endocrinology, Hospital Infantil Universitario Niño Jesús, Instituto de Investigación La Princesa, Madrid, Spain
- Department of Pediatrics, Faculty of Medicine, Universidad Autónoma de Madrid, Madrid, Spain
| | - Jesús Argente
- Department of Endocrinology, Hospital Infantil Universitario Niño Jesús, Instituto de Investigación La Princesa, Madrid, Spain
- Department of Pediatrics, Faculty of Medicine, Universidad Autónoma de Madrid, 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, Campus of International Excellence, 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 de Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos III, Madrid, Spain
- IMDEA Food Institute, Campus of International Excellence, Universidad Autónoma de Madrid, Consejo Superior de Investigaciones Científicas, Madrid, Spain
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7
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Diao S, Chen C, Benani A, Magnan C, Van Steenwinckel J, Gressens P, Cruciani-Guglielmacci C, Jacquens A, Bokobza C. Preterm birth: A neuroinflammatory origin for metabolic diseases? Brain Behav Immun Health 2024; 37:100745. [PMID: 38511150 PMCID: PMC10950814 DOI: 10.1016/j.bbih.2024.100745] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2023] [Revised: 01/16/2024] [Accepted: 02/21/2024] [Indexed: 03/22/2024] Open
Abstract
Preterm birth and its related complications have become more and more common as neonatal medicine advances. The concept of "developmental origins of health and disease" has raised awareness of adverse perinatal events in the development of diseases later in life. To explore this concept, we propose that encephalopathy of prematurity (EoP) as a potential pro-inflammatory early life event becomes a novel risk factor for metabolic diseases in children/adolescents and adulthood. Here, we review epidemiological evidence that links preterm birth to metabolic diseases and discuss possible synergic roles of preterm birth and neuroinflammation from EoP in the development of metabolic diseases. In addition, we explore theoretical underlying mechanisms regarding developmental programming of the energy control system and HPA axis.
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Affiliation(s)
- Sihao Diao
- Université Paris Cité, Inserm, NeuroDiderot, 75019, Paris, France
- Department of Neonatology, Children's Hospital of Fudan University, Shanghai, 201102, China
- Key Laboratory of Neonatal Diseases, National Health Commission, China
| | - Chao Chen
- Department of Neonatology, Children's Hospital of Fudan University, Shanghai, 201102, China
- Key Laboratory of Neonatal Diseases, National Health Commission, China
| | - Alexandre Benani
- CSGA, Centre des Sciences du Goût et de l'Alimentation, UMR 6265 CNRS, INRAE, Institut Agro Dijon, Université Bourgogne Franche-Comté, Dijon, France
| | | | | | - Pierre Gressens
- Université Paris Cité, Inserm, NeuroDiderot, 75019, Paris, France
| | | | - Alice Jacquens
- Université Paris Cité, Inserm, NeuroDiderot, 75019, Paris, France
- Department of Anesthesia and Critical Care, APHP-Sorbonne University, Hôpital La Pitié- Salpêtrière, Paris, France
| | - Cindy Bokobza
- Université Paris Cité, Inserm, NeuroDiderot, 75019, Paris, France
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8
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Sanchez C, Colson C, Gautier N, Noser P, Salvi J, Villet M, Fleuriot L, Peltier C, Schlich P, Brau F, Sharif A, Altintas A, Amri EZ, Nahon JL, Blondeau N, Benani A, Barrès R, Rovère C. Dietary fatty acid composition drives neuroinflammation and impaired behavior in obesity. Brain Behav Immun 2024; 117:330-346. [PMID: 38309640 DOI: 10.1016/j.bbi.2024.01.216] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/11/2023] [Revised: 01/17/2024] [Accepted: 01/20/2024] [Indexed: 02/05/2024] Open
Abstract
Nutrient composition in obesogenic diets may influence the severity of disorders associated with obesity such as insulin-resistance and chronic inflammation. Here we hypothesized that obesogenic diets rich in fat and varying in fatty acid composition, particularly in omega 6 (ω6) to omega 3 (ω3) ratio, have various effects on energy metabolism, neuroinflammation and behavior. Mice were fed either a control diet or a high fat diet (HFD) containing either low (LO), medium (ME) or high (HI) ω6/ω3 ratio. Mice from the HFD-LO group consumed less calories and exhibited less body weight gain compared to other HFD groups. Both HFD-ME and HFD-HI impaired glucose metabolism while HFD-LO partly prevented insulin intolerance and was associated with normal leptin levels despite higher subcutaneous and perigonadal adiposity. Only HFD-HI increased anxiety and impaired spatial memory, together with increased inflammation in the hypothalamus and hippocampus. Our results show that impaired glucose metabolism and neuroinflammation are uncoupled, and support that diets with a high ω6/ω3 ratio are associated with neuroinflammation and the behavioral deterioration coupled with the consumption of diets rich in fat.
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Affiliation(s)
- Clara Sanchez
- Université Côte d'Azur, Institut de Pharmacologie Moléculaire et Cellulaire, CNRS, France
| | - Cécilia Colson
- Université Côte d'Azur, Institut de Pharmacologie Moléculaire et Cellulaire, CNRS, France; Université Côte d'Azur, Institut de Biologie de Valrose, CNRS, INSERM, France
| | - Nadine Gautier
- Université Côte d'Azur, Institut de Biologie de Valrose, CNRS, INSERM, France
| | - Pascal Noser
- Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, Denmark
| | - Juliette Salvi
- Université Bourgogne Franche-Comté, Centre des Sciences du Goût et de l'Alimentation, CNRS, INRAe, France
| | - Maxime Villet
- Université Côte d'Azur, Institut de Pharmacologie Moléculaire et Cellulaire, CNRS, France
| | - Lucile Fleuriot
- Université Côte d'Azur, Institut de Pharmacologie Moléculaire et Cellulaire, CNRS, France
| | - Caroline Peltier
- Université Bourgogne Franche-Comté, Centre des Sciences du Goût et de l'Alimentation, CNRS, INRAe, France
| | - Pascal Schlich
- Université Bourgogne Franche-Comté, Centre des Sciences du Goût et de l'Alimentation, CNRS, INRAe, France
| | - Frédéric Brau
- Université Côte d'Azur, Institut de Pharmacologie Moléculaire et Cellulaire, CNRS, France
| | - Ariane Sharif
- Université de Lille, CHU Lille, Laboratory of Development and Plasticity of the Neuroendocrine Brain, Lille Neurosciences & Cognition, UMR-S 1172, Lille France
| | - Ali Altintas
- Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, Denmark
| | - Ez-Zoubir Amri
- Université Côte d'Azur, Institut de Biologie de Valrose, CNRS, INSERM, France
| | - Jean-Louis Nahon
- Université Côte d'Azur, Institut de Pharmacologie Moléculaire et Cellulaire, CNRS, France
| | - Nicolas Blondeau
- Université Côte d'Azur, Institut de Pharmacologie Moléculaire et Cellulaire, CNRS, France
| | - Alexandre Benani
- Université Bourgogne Franche-Comté, Centre des Sciences du Goût et de l'Alimentation, CNRS, INRAe, France
| | - Romain Barrès
- Université Côte d'Azur, Institut de Pharmacologie Moléculaire et Cellulaire, CNRS, France; Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, Denmark
| | - Carole Rovère
- Université Côte d'Azur, Institut de Pharmacologie Moléculaire et Cellulaire, CNRS, France.
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9
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Salvi J, Andreoletti P, Audinat E, Balland E, Ben Fradj S, Cherkaoui-Malki M, Heurtaux T, Liénard F, Nédélec E, Rovère C, Savary S, Véjux A, Trompier D, Benani A. Microgliosis: a double-edged sword in the control of food intake. FEBS J 2024; 291:615-631. [PMID: 35880408 DOI: 10.1111/febs.16583] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2022] [Revised: 06/30/2022] [Accepted: 07/25/2022] [Indexed: 02/16/2024]
Abstract
Maintaining energy balance is essential for survival and health. This physiological function is controlled by the brain, which adapts food intake to energy needs. Indeed, the brain constantly receives a multitude of biological signals that are derived from digested foods or that originate from the gastrointestinal tract, energy stores (liver and adipose tissues) and other metabolically active organs (muscles). These signals, which include circulating nutrients, hormones and neuronal inputs from the periphery, collectively provide information on the overall energy status of the body. In the brain, several neuronal populations can specifically detect these signals. Nutrient-sensing neurons are found in discrete brain areas and are highly enriched in the hypothalamus. In turn, specialized brain circuits coordinate homeostatic responses acting mainly on appetite, peripheral metabolism, activity and arousal. Accumulating evidence shows that hypothalamic microglial cells located at the vicinity of these circuits can influence the brain control of energy balance. However, microglial cells could have opposite effects on energy balance, that is homeostatic or detrimental, and the conditions for this shift are not totally understood yet. One hypothesis relies on the extent of microglial activation, and nutritional lipids can considerably change it.
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Affiliation(s)
- Juliette Salvi
- CSGA, Centre des Sciences du Goût et de l'Alimentation, CNRS, INRAE, Institut Agro Dijon, Université Bourgogne Franche-Comté, Dijon, France
| | - Pierre Andreoletti
- Laboratoire Bio-PeroxIL, Université Bourgogne Franche-Comté, Dijon, France
| | - Etienne Audinat
- IGF, Université de Montpellier, CNRS, Inserm, Montpellier, France
| | - Eglantine Balland
- Department of Nutrition, Dietetics and Food, School of Clinical Sciences at Monash Health, Faculty of Medicine, Nursing and Health Sciences, Monash University, Notting Hill, Australia
| | - Selma Ben Fradj
- IPMC, Institut de Pharmacologie Moléculaire et Cellulaire, CNRS, Université Côte d'Azur, Valbonne, France
| | | | - Tony Heurtaux
- Luxembourg Center of Neuropathology (LCNP), Dudelange, Luxembourg
- Department of Life Sciences and Medicine, University of Luxembourg, Belvaux, Luxembourg
| | - Fabienne Liénard
- CSGA, Centre des Sciences du Goût et de l'Alimentation, CNRS, INRAE, Institut Agro Dijon, Université Bourgogne Franche-Comté, Dijon, France
| | - Emmanuelle Nédélec
- CSGA, Centre des Sciences du Goût et de l'Alimentation, CNRS, INRAE, Institut Agro Dijon, Université Bourgogne Franche-Comté, Dijon, France
| | - Carole Rovère
- IPMC, Institut de Pharmacologie Moléculaire et Cellulaire, CNRS, Université Côte d'Azur, Valbonne, France
| | - Stéphane Savary
- Laboratoire Bio-PeroxIL, Université Bourgogne Franche-Comté, Dijon, France
| | - Anne Véjux
- Laboratoire Bio-PeroxIL, Université Bourgogne Franche-Comté, Dijon, France
| | - Doriane Trompier
- Laboratoire Bio-PeroxIL, Université Bourgogne Franche-Comté, Dijon, France
| | - Alexandre Benani
- CSGA, Centre des Sciences du Goût et de l'Alimentation, CNRS, INRAE, Institut Agro Dijon, Université Bourgogne Franche-Comté, Dijon, France
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10
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Delpech JC, Valdearcos M, Nadjar A. Stress and Microglia: A Double-edged Relationship. ADVANCES IN NEUROBIOLOGY 2024; 37:333-342. [PMID: 39207700 DOI: 10.1007/978-3-031-55529-9_18] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/04/2024]
Abstract
Microglia are highly dynamic cells and acquire different activation states to modulate their multiple functions, which are tightly regulated by the central nervous system microenvironment in which they reside. In response to stress, that is to the appearance of non-physiological signals in their vicinity, microglia will adapt their function in order to promote a return to brain homeostasis. However, when these stress signals are chronically present, microglial response may not be adapted and lead to the establishment of a pathological state. The aim of this book chapter is to examine the substantial literature around the ability of acute and chronic stressors to affect microglial structure and function, with a special focus on psychosocial and nutritional stresses. We also discuss the molecular mechanisms known to date that explain the link between exposure to stressors and microglial activation.
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Affiliation(s)
| | - Martin Valdearcos
- Diabetes Center, University of California, San Francisco, San Francisco, CA, USA
| | - Agnès Nadjar
- Neurocentre Magendie, U1215, INSERM-Université de Bordeaux, Bordeaux, France.
- Institut Universitaire de France (IUF), Paris, France.
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11
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Ameroso D, Rios M. Synaptic plasticity and the role of astrocytes in central metabolic circuits. WIREs Mech Dis 2024; 16:e1632. [PMID: 37833830 PMCID: PMC10842964 DOI: 10.1002/wsbm.1632] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2023] [Revised: 09/08/2023] [Accepted: 09/22/2023] [Indexed: 10/15/2023]
Abstract
Neural circuits in the brain, primarily in the hypothalamus, are paramount to the homeostatic control of feeding and energy utilization. They integrate hunger, satiety, and body adiposity cues from the periphery and mediate the appropriate behavioral and physiological responses to satisfy the energy demands of the animal. Notably, perturbations in central homeostatic circuits have been linked to the etiology of excessive feeding and obesity. Considering the ever-changing energy requirements of the animal and required adaptations, it is not surprising that brain-feeding circuits remain plastic in adulthood and are subject to changes in synaptic strength as a consequence of nutritional status. Indeed, synapse density, probability of presynaptic transmitter release, and postsynaptic responses in hypothalamic energy balance centers are tailored to behavioral and physiological responses required to sustain survival. Mounting evidence supports key roles of astrocytes facilitating some of this plasticity. Here we discuss these synaptic plasticity mechanisms and the emerging roles of astrocytes influencing energy and glucose balance control in health and disease. This article is categorized under: Cancer > Molecular and Cellular Physiology Neurological Diseases > Molecular and Cellular Physiology.
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Affiliation(s)
- Dominique Ameroso
- Graduate Program in Neuroscience, Graduate School of Biomedical Sciences, Tufts University School of Medicine, Boston, MA 02111
| | - Maribel Rios
- Graduate Program in Neuroscience, Graduate School of Biomedical Sciences, Tufts University School of Medicine, Boston, MA 02111
- Department of Neuroscience, Tufts University School of Medicine, Boston, MA 02111
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12
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Kim JD, Copperi F, Diano S. Microglia in Central Control of Metabolism. Physiology (Bethesda) 2024; 39:0. [PMID: 37962895 PMCID: PMC11283896 DOI: 10.1152/physiol.00021.2023] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2023] [Revised: 11/12/2023] [Accepted: 11/12/2023] [Indexed: 11/15/2023] Open
Abstract
Beyond their role as brain immune cells, microglia act as metabolic sensors in response to changes in nutrient availability, thus playing a role in energy homeostasis. This review highlights the evidence and challenges of studying the role of microglia in metabolism regulation.
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Affiliation(s)
- Jung Dae Kim
- Institute of Human Nutrition, Columbia University Irving Medical Center, New York, New York, United States
| | - Francesca Copperi
- Institute of Human Nutrition, Columbia University Irving Medical Center, New York, New York, United States
| | - Sabrina Diano
- Institute of Human Nutrition, Columbia University Irving Medical Center, New York, New York, United States
- Department of Molecular Pharmacology and Therapeutics, Columbia University Irving Medical Center, New York, New York, United States
- Department of Physiology and Cellular Biophysics, Columbia University Irving Medical Center, New York, New York, United States
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13
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Dali R, Estrada-Meza J, Langlet F. Tanycyte, the neuron whisperer. Physiol Behav 2023; 263:114108. [PMID: 36740135 DOI: 10.1016/j.physbeh.2023.114108] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2022] [Revised: 01/23/2023] [Accepted: 02/01/2023] [Indexed: 02/05/2023]
Abstract
Reciprocal communication between neurons and glia is essential for normal brain functioning and adequate physiological functions, including energy balance. In vertebrates, the homeostatic process that adjusts food intake and energy expenditure in line with physiological requirements is tightly controlled by numerous neural cell types located within the hypothalamus and the brainstem and organized in complex networks. Within these neural networks, peculiar ependymoglial cells called tanycytes are nowadays recognized as multifunctional players in the physiological mechanisms of appetite control, partly by modulating orexigenic and anorexigenic neurons. Here, we review recent advances in tanycytes' impact on hypothalamic neuronal activity, emphasizing on arcuate neurons.
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Affiliation(s)
- Rafik Dali
- Department of biomedical sciences, University of Lausanne, 1005 Lausanne, Switzerland
| | - Judith Estrada-Meza
- Department of biomedical sciences, University of Lausanne, 1005 Lausanne, Switzerland
| | - Fanny Langlet
- Department of biomedical sciences, University of Lausanne, 1005 Lausanne, Switzerland.
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14
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Bouyakdan K, Manceau R, Robb JL, Rodaros D, Fulton S, Alquier T. Role of astroglial ACBP in energy metabolism flexibility and feeding responses to metabolic challenges in male mice. J Neuroendocrinol 2022; 34:e13218. [PMID: 36471907 DOI: 10.1111/jne.13218] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/01/2022] [Revised: 10/26/2022] [Accepted: 11/10/2022] [Indexed: 11/19/2022]
Abstract
Acyl-CoA binding protein (ACBP), also known as diazepam binding inhibitor (DBI), has recently emerged as a hypothalamic and brainstem gliopeptide regulating energy balance. Previous work has shown that the ACBP-derived octadecaneuropeptide exerts strong anorectic action via proopiomelanocortin (POMC) neuron activation and the melanocortin-4 receptor. Importantly, targeted ACBP loss-of-function in astrocytes promotes hyperphagia and diet-induced obesity while its overexpression in arcuate astrocytes reduces feeding and body weight. Despite this knowledge, the role of astroglial ACBP in adaptive feeding and metabolic responses to acute metabolic challenges has not been investigated. Using different paradigms, we found that ACBP deletion in glial fibrillary acidic protein (GFAP)-positive astrocytes does not affect weight loss when obese male mice are transitioned from a high fat diet to a chow diet, nor metabolic parameters in mice fed with a normal chow diet (e.g., energy expenditure, body temperature) during fasting, cold exposure and at thermoneutrality. In contrast, astroglial ACBP deletion impairs meal pattern and feeding responses during refeeding after a fast and during cold exposure, thereby showing that ACBP is required to stimulate feeding in states of increased energy demand. These findings challenge the general view that astroglial ACBP exerts anorectic effects and suggest that regulation of feeding by ACBP is dependent on metabolic status.
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Affiliation(s)
- Khalil Bouyakdan
- Centre de Recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), Montreal Diabetes Research Center, and Departments of Medicine and Neurosciences and Nutrition, Université de Montréal, Montréal, Quebec, Canada
| | - Romane Manceau
- Centre de Recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), Montreal Diabetes Research Center, and Departments of Medicine and Neurosciences and Nutrition, Université de Montréal, Montréal, Quebec, Canada
| | - Josephine L Robb
- Centre de Recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), Montreal Diabetes Research Center, and Departments of Medicine and Neurosciences and Nutrition, Université de Montréal, Montréal, Quebec, Canada
| | - Demetra Rodaros
- Centre de Recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), Montreal Diabetes Research Center, and Departments of Medicine and Neurosciences and Nutrition, Université de Montréal, Montréal, Quebec, Canada
| | - Stephanie Fulton
- Centre de Recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), Montreal Diabetes Research Center, and Departments of Medicine and Neurosciences and Nutrition, Université de Montréal, Montréal, Quebec, Canada
| | - Thierry Alquier
- Centre de Recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), Montreal Diabetes Research Center, and Departments of Medicine and Neurosciences and Nutrition, Université de Montréal, Montréal, Quebec, Canada
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15
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Campillo BW, Galguera D, Cerdan S, López-Larrubia P, Lizarbe B. Short-term high-fat diet alters the mouse brain magnetic resonance imaging parameters consistently with neuroinflammation on males and metabolic rearrangements on females. A pre-clinical study with an optimized selection of linear mixed-effects models. Front Neurosci 2022; 16:1025108. [PMID: 36507349 PMCID: PMC9729798 DOI: 10.3389/fnins.2022.1025108] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2022] [Accepted: 10/20/2022] [Indexed: 11/25/2022] Open
Abstract
Introduction High-fat diet (HFD) consumption is known to trigger an inflammatory response in the brain that prompts the dysregulation of energy balance, leads to insulin and leptin resistance, and ultimately obesity. Obesity, at the same, has been related to cerebral magnetic resonance imaging (MRI) alterations, but the onset of HFD-induced neuroinflammation, however, has been principally reported on male rodents and by ex vivo methods, with the effects on females and the origin of MRI changes remaining unassessed. Methods We characterized the onset and evolution of obesity on male and female mice during standard or HFD administration by physiological markers and multiparametric MRI on four cerebral regions involved in appetite regulation and energy homeostasis. We investigated the effects of diet, time under diet, brain region and sex by identifying their significant contributions to sequential linear mixed-effects models, and obtained their regional neurochemical profiles by high-resolution magic angle spinning spectroscopy. Results Male mice developed an obese phenotype paralleled by fast increases in magnetization transfer ratio values, while females delayed the obesity progress and showed no MRI-signs of cerebral inflammation, but larger metabolic rearrangements on the neurochemical profile. Discussion Our study reveals early MRI-detectable changes compatible with the development of HFD-induced cerebral cytotoxic inflammation on males but suggest the existence of compensatory metabolic adaptations on females that preclude the corresponding detection of MRI alterations.
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Affiliation(s)
- Basilio Willem Campillo
- Instituto de Investigaciones Biomédicas Alberto Sols (IIBm), Consejo Superior de Investigaciones Científicas-Universidad Autónoma de Madrid (CSIC-UAM), Madrid, Spain
| | - David Galguera
- Instituto de Investigaciones Biomédicas Alberto Sols (IIBm), Consejo Superior de Investigaciones Científicas-Universidad Autónoma de Madrid (CSIC-UAM), Madrid, Spain
| | - Sebastian Cerdan
- Instituto de Investigaciones Biomédicas Alberto Sols (IIBm), Consejo Superior de Investigaciones Científicas-Universidad Autónoma de Madrid (CSIC-UAM), Madrid, Spain
| | - Pilar López-Larrubia
- Instituto de Investigaciones Biomédicas Alberto Sols (IIBm), Consejo Superior de Investigaciones Científicas-Universidad Autónoma de Madrid (CSIC-UAM), Madrid, Spain,Pilar López-Larrubia,
| | - Blanca Lizarbe
- Instituto de Investigaciones Biomédicas Alberto Sols (IIBm), Consejo Superior de Investigaciones Científicas-Universidad Autónoma de Madrid (CSIC-UAM), Madrid, Spain,Departamento de Bioquímica, Universidad Autónoma de Madrid (UAM), Instituto de Investigaciones Biomédicas Alberto Sols (CSIC-UAM), Madrid, Spain,*Correspondence: Blanca Lizarbe,
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16
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Basilico B, Ferrucci L, Khan A, Di Angelantonio S, Ragozzino D, Reverte I. What microglia depletion approaches tell us about the role of microglia on synaptic function and behavior. Front Cell Neurosci 2022; 16:1022431. [PMID: 36406752 PMCID: PMC9673171 DOI: 10.3389/fncel.2022.1022431] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2022] [Accepted: 10/17/2022] [Indexed: 11/06/2022] Open
Abstract
Microglia are dynamic cells, constantly surveying their surroundings and interacting with neurons and synapses. Indeed, a wealth of knowledge has revealed a critical role of microglia in modulating synaptic transmission and plasticity in the developing brain. In the past decade, novel pharmacological and genetic strategies have allowed the acute removal of microglia, opening the possibility to explore and understand the role of microglia also in the adult brain. In this review, we summarized and discussed the contribution of microglia depletion strategies to the current understanding of the role of microglia on synaptic function, learning and memory, and behavior both in physiological and pathological conditions. We first described the available microglia depletion methods highlighting their main strengths and weaknesses. We then reviewed the impact of microglia depletion on structural and functional synaptic plasticity. Next, we focused our analysis on the effects of microglia depletion on behavior, including general locomotor activity, sensory perception, motor function, sociability, learning and memory both in healthy animals and animal models of disease. Finally, we integrated the findings from the reviewed studies and discussed the emerging roles of microglia on the maintenance of synaptic function, learning, memory strength and forgetfulness, and the implications of microglia depletion in models of brain disease.
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Affiliation(s)
| | - Laura Ferrucci
- Department of Physiology and Pharmacology, Sapienza University of Rome, Rome, Italy
| | - Azka Khan
- Department of Physiology and Pharmacology, Sapienza University of Rome, Rome, Italy
| | - Silvia Di Angelantonio
- Department of Physiology and Pharmacology, Sapienza University of Rome, Rome, Italy
- Center for Life Nano- and Neuro-Science, Istituto Italiano di Tecnologia, Rome, Italy
| | - Davide Ragozzino
- Laboratory Affiliated to Institute Pasteur Italia – Fondazione Cenci Bolognetti, Department of Physiology and Pharmacology, Sapienza University of Rome, Rome, Italy
- Santa Lucia Foundation (IRCCS Fondazione Santa Lucia), Rome, Italy
- *Correspondence: Davide Ragozzino,
| | - Ingrid Reverte
- Department of Physiology and Pharmacology, Sapienza University of Rome, Rome, Italy
- Santa Lucia Foundation (IRCCS Fondazione Santa Lucia), Rome, Italy
- Ingrid Reverte,
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17
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Trends in Gliosis in Obesity, and the Role of Antioxidants as a Therapeutic Alternative. Antioxidants (Basel) 2022; 11:antiox11101972. [PMID: 36290695 PMCID: PMC9598641 DOI: 10.3390/antiox11101972] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2022] [Revised: 09/23/2022] [Accepted: 09/29/2022] [Indexed: 11/16/2022] Open
Abstract
Obesity remains a global health problem. Chronic low-grade inflammation in this pathology has been related to comorbidities such as cognitive alterations that, in the long term, can lead to neurodegenerative diseases. Neuroinflammation or gliosis in patients with obesity and type 2 diabetes mellitus has been related to the effect of adipokines, high lipid levels and glucose, which increase the production of free radicals. Cerebral gliosis can be a risk factor for developing neurodegenerative diseases, and antioxidants could be an alternative for the prevention and treatment of neural comorbidities in obese patients. AIM Identify the immunological and oxidative stress mechanisms that produce gliosis in patients with obesity and propose antioxidants as an alternative to reducing neuroinflammation. METHOD Advanced searches were performed in scientific databases: PubMed, ProQuest, EBSCO, and the Science Citation index for research on the physiopathology of gliosis in obese patients and for the possible role of antioxidants in its management. CONCLUSION Patients with obesity can develop neuroinflammation, conditioned by various adipokines, excess lipids and glucose, which results in an increase in free radicals that must be neutralized with antioxidants to reduce gliosis and the risk of long-term neurodegeneration.
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18
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Zhou R, He M, Fan J, Li R, Zuo Y, Li B, Gao G, Sun T. The role of hypothalamic endoplasmic reticulum stress in schizophrenia and antipsychotic-induced weight gain: A narrative review. Front Neurosci 2022; 16:947295. [PMID: 36188456 PMCID: PMC9523121 DOI: 10.3389/fnins.2022.947295] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2022] [Accepted: 08/29/2022] [Indexed: 11/21/2022] Open
Abstract
Schizophrenia (SCZ) is a serious mental illness that affects 1% of people worldwide. SCZ is associated with a higher risk of developing metabolic disorders such as obesity. Antipsychotics are the main treatment for SCZ, but their side effects include significant weight gain/obesity. Despite extensive research, the underlying mechanisms by which SCZ and antipsychotic treatment induce weight gain/obesity remain unclear. Hypothalamic endoplasmic reticulum (ER) stress is one of the most important pathways that modulates inflammation, neuronal function, and energy balance. This review aimed to investigate the role of hypothalamic ER stress in SCZ and antipsychotic-induced weight gain/obesity. Preliminary evidence indicates that SCZ is associated with reduced dopamine D2 receptor (DRD2) signaling, which significantly regulates the ER stress pathway, suggesting the importance of ER stress in SCZ and its related metabolic disorders. Antipsychotics such as olanzapine activate ER stress in hypothalamic neurons. These effects may induce decreased proopiomelanocortin (POMC) processing, increased neuropeptide Y (NPY) and agouti-related protein (AgRP) expression, autophagy, and leptin and insulin resistance, resulting in hyperphagia, decreased energy expenditure, and central inflammation, thereby causing weight gain. By activating ER stress, antipsychotics such as olanzapine activate hypothalamic astrocytes and Toll-like receptor 4 signaling, thereby causing inflammation and weight gain/obesity. Moreover, evidence suggests that antipsychotic-induced ER stress may be related to their antagonistic effects on neurotransmitter receptors such as DRD2 and the histamine H1 receptor. Taken together, ER stress inhibitors could be a potential effective intervention against SCZ and antipsychotic-induced weight gain and inflammation.
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Affiliation(s)
- Ruqin Zhou
- School of Chemistry, Chemical Engineering and Life Sciences, Wuhan University of Technology, Wuhan, China
| | - Meng He
- School of Chemistry, Chemical Engineering and Life Sciences, Wuhan University of Technology, Wuhan, China
- *Correspondence: Meng He,
| | - Jun Fan
- School of Chemistry, Chemical Engineering and Life Sciences, Wuhan University of Technology, Wuhan, China
| | - Ruoxi Li
- School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Yufeng Zuo
- School of Chemistry, Chemical Engineering and Life Sciences, Wuhan University of Technology, Wuhan, China
| | - Benben Li
- School of Chemistry, Chemical Engineering and Life Sciences, Wuhan University of Technology, Wuhan, China
| | - Guanbin Gao
- State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan, China
- Guanbin Gao,
| | - Taolei Sun
- School of Chemistry, Chemical Engineering and Life Sciences, Wuhan University of Technology, Wuhan, China
- Taolei Sun,
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19
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Ben Fradj S, Nédélec E, Salvi J, Fouesnard M, Huillet M, Pallot G, Cansell C, Sanchez C, Philippe C, Gigot V, Lemoine A, Trompier D, Henry T, Petrilli V, Py BF, Guillou H, Loiseau N, Ellero-Simatos S, Nahon JL, Rovère C, Grober J, Boudry G, Douard V, Benani A. Evidence for Constitutive Microbiota-Dependent Short-Term Control of Food Intake in Mice: Is There a Link with Inflammation, Oxidative Stress, Endotoxemia, and GLP-1? Antioxid Redox Signal 2022; 37:349-369. [PMID: 35166124 DOI: 10.1089/ars.2021.0095] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Aims: Although prebiotics, probiotics, and fecal transplantation can alter the sensation of hunger and/or feeding behavior, the role of the constitutive gut microbiota in the short-term regulation of food intake during normal physiology is still unclear. Results: An antibiotic-induced microbiota depletion study was designed to compare feeding behavior in conventional and microbiota-depleted mice. Tissues were sampled to characterize the time profile of microbiota-derived signals in mice during consumption of either standard or high-fat food for 1 h. Pharmacological and genetic tools were used to evaluate the contribution of postprandial endotoxemia and inflammatory responses in the short-term regulation of food intake. We observed constitutive microbial and macronutrient-dependent control of food intake at the time scale of a meal; that is, within 1 h of food introduction. Specifically, microbiota depletion increased food intake, and the microbiota-derived anorectic effect became significant during the consumption of high-fat but not standard food. This anorectic effect correlated with a specific postprandial microbial metabolic signature, and did not require postprandial endotoxemia or an NOD-, LRR-, and Pyrin domain-containing protein 3-inflammasome-mediated inflammatory response. Innovation and Conclusion: These findings show that the gut microbiota controls host appetite at the time scale of a meal under normal physiology. Interestingly, a microbiota-derived anorectic effect develops specifically with a high-fat meal, indicating that gut microbiota activity is involved in the satietogenic properties of foods. Antioxid. Redox Signal. 37, 349-369.
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Affiliation(s)
- Selma Ben Fradj
- CSGA, Centre des Sciences du Goût et de l'Alimentation, CNRS (UMR6265), INRAE (UMR1324), Institut Agro Dijon, Université Bourgogne Franche-Comté, Dijon, France
| | - Emmanuelle Nédélec
- CSGA, Centre des Sciences du Goût et de l'Alimentation, CNRS (UMR6265), INRAE (UMR1324), Institut Agro Dijon, Université Bourgogne Franche-Comté, Dijon, France
| | - Juliette Salvi
- CSGA, Centre des Sciences du Goût et de l'Alimentation, CNRS (UMR6265), INRAE (UMR1324), Institut Agro Dijon, Université Bourgogne Franche-Comté, Dijon, France
| | - Mélanie Fouesnard
- Institut Micalis, INRAE (UMR1319), AgroParisTech, Université Paris-Saclay, Jouy-en-Josas, France.,Institut NuMeCan, INRAE (UMR1341), INSERM (UMR1241), Université de Rennes 1, St-Gilles, France
| | - Marine Huillet
- Toxalim (Research Centre in Food Toxicology), Université de Toulouse 3, INRAE (UMR1331), ENVT, INP-Purpan, Université Paul Sabatier, Toulouse, France
| | - Gaëtan Pallot
- Centre de Recherche Lipides, Nutrition, Cancer, INSERM (UMR1231), Institut Agro Dijon, Université Bourgogne Franche-Comté, Dijon, France
| | - Céline Cansell
- IPMC, Institut de Pharmacologie Moléculaire et Cellulaire, CNRS (UMR7275), Université Côte d'Azur, Valbonne, France
| | - Clara Sanchez
- IPMC, Institut de Pharmacologie Moléculaire et Cellulaire, CNRS (UMR7275), Université Côte d'Azur, Valbonne, France
| | - Catherine Philippe
- Institut Micalis, INRAE (UMR1319), AgroParisTech, Université Paris-Saclay, Jouy-en-Josas, France
| | - Vincent Gigot
- CSGA, Centre des Sciences du Goût et de l'Alimentation, CNRS (UMR6265), INRAE (UMR1324), Institut Agro Dijon, Université Bourgogne Franche-Comté, Dijon, France
| | - Aleth Lemoine
- CSGA, Centre des Sciences du Goût et de l'Alimentation, CNRS (UMR6265), INRAE (UMR1324), Institut Agro Dijon, Université Bourgogne Franche-Comté, Dijon, France
| | - Doriane Trompier
- CSGA, Centre des Sciences du Goût et de l'Alimentation, CNRS (UMR6265), INRAE (UMR1324), Institut Agro Dijon, Université Bourgogne Franche-Comté, Dijon, France
| | - Thomas Henry
- CIRI, Centre International de Recherche en Infectiologie, Inserm (U1111), CNRS (UMR5308), ENS de Lyon, Université Claude Bernard Lyon 1, Lyon, France
| | - Virginie Petrilli
- Centre de Recherche en Cancérologie de Lyon, Inserm (U1052), CNRS (UMR5286), Université de Lyon 1, Lyon, France
| | - Benedicte F Py
- CIRI, Centre International de Recherche en Infectiologie, Inserm (U1111), CNRS (UMR5308), ENS de Lyon, Université Claude Bernard Lyon 1, Lyon, France
| | - Hervé Guillou
- Toxalim (Research Centre in Food Toxicology), Université de Toulouse 3, INRAE (UMR1331), ENVT, INP-Purpan, Université Paul Sabatier, Toulouse, France
| | - Nicolas Loiseau
- Toxalim (Research Centre in Food Toxicology), Université de Toulouse 3, INRAE (UMR1331), ENVT, INP-Purpan, Université Paul Sabatier, Toulouse, France
| | - Sandrine Ellero-Simatos
- Toxalim (Research Centre in Food Toxicology), Université de Toulouse 3, INRAE (UMR1331), ENVT, INP-Purpan, Université Paul Sabatier, Toulouse, France
| | - Jean-Louis Nahon
- IPMC, Institut de Pharmacologie Moléculaire et Cellulaire, CNRS (UMR7275), Université Côte d'Azur, Valbonne, France
| | - Carole Rovère
- IPMC, Institut de Pharmacologie Moléculaire et Cellulaire, CNRS (UMR7275), Université Côte d'Azur, Valbonne, France
| | - Jacques Grober
- Centre de Recherche Lipides, Nutrition, Cancer, INSERM (UMR1231), Institut Agro Dijon, Université Bourgogne Franche-Comté, Dijon, France
| | - Gaelle Boudry
- Institut NuMeCan, INRAE (UMR1341), INSERM (UMR1241), Université de Rennes 1, St-Gilles, France
| | - Véronique Douard
- Institut Micalis, INRAE (UMR1319), AgroParisTech, Université Paris-Saclay, Jouy-en-Josas, France
| | - Alexandre Benani
- CSGA, Centre des Sciences du Goût et de l'Alimentation, CNRS (UMR6265), INRAE (UMR1324), Institut Agro Dijon, Université Bourgogne Franche-Comté, Dijon, France
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Nampoothiri S, Nogueiras R, Schwaninger M, Prevot V. Glial cells as integrators of peripheral and central signals in the regulation of energy homeostasis. Nat Metab 2022; 4:813-825. [PMID: 35879459 PMCID: PMC7613794 DOI: 10.1038/s42255-022-00610-z] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/03/2021] [Accepted: 06/15/2022] [Indexed: 01/03/2023]
Abstract
Communication between the periphery and the brain is key for maintaining energy homeostasis. To do so, peripheral signals from the circulation reach the brain via the circumventricular organs (CVOs), which are characterized by fenestrated vessels lacking the protective blood-brain barrier (BBB). Glial cells, by virtue of their plasticity and their ideal location at the interface of blood vessels and neurons, participate in the integration and transmission of peripheral information to neuronal networks in the brain for the neuroendocrine control of whole-body metabolism. Metabolic diseases, such as obesity and type 2 diabetes, can disrupt the brain-to-periphery communication mediated by glial cells, highlighting the relevance of these cell types in the pathophysiology of such complications. An improved understanding of how glial cells integrate and respond to metabolic and humoral signals has become a priority for the discovery of promising therapeutic strategies to treat metabolic disorders. This Review highlights the role of glial cells in the exchange of metabolic signals between the periphery and the brain that are relevant for the regulation of whole-body energy homeostasis.
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Affiliation(s)
- Sreekala Nampoothiri
- Univ. Lille, Inserm, CHU Lille, Laboratory of Development and Plasticity of the Neuroendocrine Brain, Lille Neuroscience & Cognition, UMR-S1172, EGID, DISTALZ, Lille, France
| | - Ruben Nogueiras
- Universidade de Santiago de Compostela-Instituto de Investigation Sanitaria, Santiago de Compostela, Spain
- CIBER Fisiopatologia de la Obesidad y Nutrition, Santiago de Compostela, Spain
| | - Markus Schwaninger
- Institute for Experimental and Clinical Pharmacology and Toxicology, University of Lübeck, Lübeck, Germany
| | - Vincent Prevot
- Univ. Lille, Inserm, CHU Lille, Laboratory of Development and Plasticity of the Neuroendocrine Brain, Lille Neuroscience & Cognition, UMR-S1172, EGID, DISTALZ, Lille, France.
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21
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Mendes NF, Velloso LA. Perivascular macrophages in high-fat diet-induced hypothalamic inflammation. J Neuroinflammation 2022; 19:136. [PMID: 35681242 PMCID: PMC9185933 DOI: 10.1186/s12974-022-02519-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Accepted: 06/01/2022] [Indexed: 02/06/2023] Open
Abstract
Brain macrophages and microglia are centrally involved in immune surveillance of the central nervous system. Upon inflammatory stimuli, they become reactive and release key molecules to prevent further damage to the neuronal network. In the hypothalamic area, perivascular macrophages (PVMs) are the first line of host defence against pathogenic organisms, particles and/or substances from the blood. They are distributed throughout the circumventricular organ median eminence, wrapping endothelial cells from fenestrated portal capillaries and in the hypothalamic vascular network, where they are localised in the perivascular space of the blood-brain barrier (BBB). Some studies have indicated that PVMs from the hypothalamus increase the expression of inducible nitric oxide synthase and vascular endothelial growth factor upon feeding for a long time on a high-fat diet. This adaptive response contributes to the impairment of glucose uptake, facilitates BBB leakage and leads to increased lipid and inflammatory cell influx towards the hypothalamic parenchyma. Despite these early findings, there is still a lack of studies exploring the mechanisms by which PVMs contribute to the development of obesity-related hypothalamic dysfunction, particularly at the early stages when there is chemotaxis of peripheral myeloid cells into the mediobasal hypothalamus. Here, we reviewed the studies involving the ontogeny, hallmarks and main features of brain PVMs in vascular homeostasis, inflammation and neuroendocrine control. This review provides a framework for understanding the potential involvement of PVMs in diet-induced hypothalamic inflammation.
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Affiliation(s)
- Natalia F Mendes
- Laboratory of Cell Signaling, Obesity and Comorbidities Research Center, University of Campinas, Rua Carl Von Linnaeus s/n, Instituto de Biologia - Bloco Z. Campus Universitário Zeferino Vaz - Barão Geraldo, Campinas, SP, 13083-864, Brazil.
| | - Licio A Velloso
- Laboratory of Cell Signaling, Obesity and Comorbidities Research Center, University of Campinas, Rua Carl Von Linnaeus s/n, Instituto de Biologia - Bloco Z. Campus Universitário Zeferino Vaz - Barão Geraldo, Campinas, SP, 13083-864, Brazil.,National Institute of Science and Technology on Neuroimmunomodulation, Rio de Janeiro, Brazil
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22
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Folick A, Cheang RT, Valdearcos M, Koliwad SK. Metabolic factors in the regulation of hypothalamic innate immune responses in obesity. Exp Mol Med 2022; 54:393-402. [PMID: 35474339 PMCID: PMC9076660 DOI: 10.1038/s12276-021-00666-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2021] [Accepted: 05/13/2021] [Indexed: 12/14/2022] Open
Abstract
The hypothalamus is a central regulator of body weight and energy homeostasis. There is increasing evidence that innate immune activation in the mediobasal hypothalamus (MBH) is a key element in the pathogenesis of diet-induced obesity. Microglia, the resident immune cells in the brain parenchyma, have been shown to play roles in diverse aspects of brain function, including circuit refinement and synaptic pruning. As such, microglia have also been implicated in the development and progression of neurological diseases. Microglia express receptors for and are responsive to a wide variety of nutritional, hormonal, and immunological signals that modulate their distinct functions across different brain regions. We showed that microglia within the MBH sense and respond to a high-fat diet and regulate the function of hypothalamic neurons to promote food intake and obesity. Neurons, glia, and immune cells within the MBH are positioned to sense and respond to circulating signals that regulate their capacity to coordinate aspects of systemic energy metabolism. Here, we review the current knowledge of how these peripheral signals modulate the innate immune response in the MBH and enable microglia to regulate metabolic control.
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Affiliation(s)
- Andrew Folick
- Diabetes Center and Division of Endocrinology and Metabolism, Department of Medicine, University of California, San Francisco, CA, USA
| | - Rachel T Cheang
- Diabetes Center and Division of Endocrinology and Metabolism, Department of Medicine, University of California, San Francisco, CA, USA
| | - Martin Valdearcos
- Diabetes Center and Division of Endocrinology and Metabolism, Department of Medicine, University of California, San Francisco, CA, USA.
| | - Suneil K Koliwad
- Diabetes Center and Division of Endocrinology and Metabolism, Department of Medicine, University of California, San Francisco, CA, USA.
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23
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Sa M, Park MG, Lee CJ. Role of Hypothalamic Reactive Astrocytes in Diet-Induced Obesity. Mol Cells 2022; 45:65-75. [PMID: 35236781 PMCID: PMC8907000 DOI: 10.14348/molcells.2022.2044] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2021] [Revised: 01/07/2022] [Accepted: 01/12/2022] [Indexed: 11/30/2022] Open
Abstract
Hypothalamus is a brain region that controls food intake and energy expenditure while sensing signals that convey information about energy status. Within the hypothalamus, molecularly and functionally distinct neurons work in concert under physiological conditions. However, under pathological conditions such as in diet-induced obesity (DIO) model, these neurons show dysfunctional firing patterns and distorted regulation by neurotransmitters and neurohormones. Concurrently, resident glial cells including astrocytes dramatically transform into reactive states. In particular, it has been reported that reactive astrogliosis is observed in the hypothalamus, along with various neuroinflammatory signals. However, how the reactive astrocytes control and modulate DIO by influencing neighboring neurons is not well understood. Recently, new lines of evidence have emerged indicating that these reactive astrocytes directly contribute to the pathology of obesity by synthesizing and tonically releasing the major inhibitory transmitter GABA. The released GABA strongly inhibits the neighboring neurons that control energy expenditure. These surprising findings shed light on the interplay between reactive astrocytes and neighboring neurons in the hypothalamus. This review summarizes recent discoveries related to the functions of hypothalamic reactive astrocytes in obesity and raises new potential therapeutic targets against obesity.
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Affiliation(s)
- Moonsun Sa
- KU-KIST Graduate School of Converging Science and Technology, Korea University, Seoul 02841, Korea
- Center for Cognition and Sociality, Institute for Basic Science (IBS), Daejeon 34126, Korea
| | - Mingu Gordon Park
- KU-KIST Graduate School of Converging Science and Technology, Korea University, Seoul 02841, Korea
- Center for Cognition and Sociality, Institute for Basic Science (IBS), Daejeon 34126, Korea
| | - C. Justin Lee
- KU-KIST Graduate School of Converging Science and Technology, Korea University, Seoul 02841, Korea
- Center for Cognition and Sociality, Institute for Basic Science (IBS), Daejeon 34126, Korea
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24
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Engel DF, Velloso LA. The timeline of neuronal and glial alterations in experimental obesity. Neuropharmacology 2022; 208:108983. [PMID: 35143850 DOI: 10.1016/j.neuropharm.2022.108983] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Revised: 01/03/2022] [Accepted: 02/02/2022] [Indexed: 12/14/2022]
Abstract
In experimental models, hypothalamic dysfunction is a key component of the pathophysiology of diet-induced obesity. Early after the introduction of a high-fat diet, neurons, microglia, astrocytes and tanycytes of the mediobasal hypothalamus undergo structural and functional changes that impact caloric intake, energy expenditure and systemic glucose tolerance. Inflammation has emerged as a central component of this response, and as in other inflammatory conditions, there is a time course of events that determine the fate of distinct cells involved in the central regulation of whole-body energy homeostasis. Here, we review the work that identified key mechanisms, cellular players and temporal features of diet-induced hypothalamic abnormalities.
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Affiliation(s)
- Daiane F Engel
- School of Pharmacy, Federal University of Ouro Preto, Brazil
| | - Licio A Velloso
- Laboratory of Cell Signaling, Obesity and Comorbidities Research Center, University of Campinas, Brazil.
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25
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Bhusal A, Rahman MH, Suk K. Hypothalamic inflammation in metabolic disorders and aging. Cell Mol Life Sci 2021; 79:32. [PMID: 34910246 PMCID: PMC11071926 DOI: 10.1007/s00018-021-04019-x] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Revised: 09/01/2021] [Accepted: 10/29/2021] [Indexed: 12/15/2022]
Abstract
The hypothalamus is a critical brain region for the regulation of energy homeostasis. Over the years, studies on energy metabolism primarily focused on the neuronal component of the hypothalamus. Studies have recently uncovered the vital role of glial cells as an additional player in energy balance regulation. However, their inflammatory activation under metabolic stress condition contributes to various metabolic diseases. The recruitment of monocytes and macrophages in the hypothalamus helps sustain such inflammation and worsens the disease state. Neurons were found to actively participate in hypothalamic inflammatory response by transmitting signals to the surrounding non-neuronal cells. This activation of different cell types in the hypothalamus leads to chronic, low-grade inflammation, impairing energy balance and contributing to defective feeding habits, thermogenesis, and insulin and leptin signaling, eventually leading to metabolic disorders (i.e., diabetes, obesity, and hypertension). The hypothalamus is also responsible for the causation of systemic aging under metabolic stress. A better understanding of the multiple factors contributing to hypothalamic inflammation, the role of the different hypothalamic cells, and their crosstalks may help identify new therapeutic targets. In this review, we focus on the role of glial cells in establishing a cause-effect relationship between hypothalamic inflammation and the development of metabolic diseases. We also cover the role of other cell types and discuss the possibilities and challenges of targeting hypothalamic inflammation as a valid therapeutic approach.
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Affiliation(s)
- Anup Bhusal
- Department of Pharmacology, School of Medicine, Kyungpook National University, Daegu, 41944, Republic of Korea
- BK21 Plus KNU Biomedical Convergence Program, Department of Biomedical Science, School of Medicine, Kyungpook National University, Daegu, 41944, Republic of Korea
| | - Md Habibur Rahman
- Department of Pharmacology, School of Medicine, Kyungpook National University, Daegu, 41944, Republic of Korea
- Division of Endocrinology, Department of Medicine, Rutgers Robert Wood Johnson Medical School, New Brunswick, NJ, 08901, USA
| | - Kyoungho Suk
- Department of Pharmacology, School of Medicine, Kyungpook National University, Daegu, 41944, Republic of Korea.
- BK21 Plus KNU Biomedical Convergence Program, Department of Biomedical Science, School of Medicine, Kyungpook National University, Daegu, 41944, Republic of Korea.
- Brain Science and Engineering Institute, Kyungpook National University, Daegu, 41944, Republic of Korea.
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26
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Hypothalamic Astrocytes as a Specialized and Responsive Cell Population in Obesity. Int J Mol Sci 2021; 22:ijms22126176. [PMID: 34201099 PMCID: PMC8228119 DOI: 10.3390/ijms22126176] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2021] [Revised: 06/03/2021] [Accepted: 06/04/2021] [Indexed: 12/11/2022] Open
Abstract
Astrocytes are a type of glial cell anatomically and functionally integrated into the neuronal regulatory circuits for the neuroendocrine control of metabolism. Being functional integral compounds of synapses, astrocytes are actively involved in the physiological regulatory aspects of metabolic control, but also in the pathological processes that link neuronal dysfunction and obesity. Between brain areas, the hypothalamus harbors specialized functional circuits that seem selectively vulnerable to metabolic damage, undergoing early cellular rearrangements which are thought to be at the core of the pathogenesis of diet-induced obesity. Such changes in the hypothalamic brain region consist of a rise in proinflammatory cytokines, the presence of a reactive phenotype in astrocytes and microglia, alterations in the cytoarchitecture and synaptology of hypothalamic circuits, and angiogenesis, a phenomenon that cannot be found elsewhere in the brain. Increasing evidence points to the direct involvement of hypothalamic astrocytes in such early metabolic disturbances, thus moving the study of these glial cells to the forefront of obesity research. Here we provide a comprehensive review of the most relevant findings of molecular and pathophysiological mechanisms by which hypothalamic astrocytes might be involved in the pathogenesis of obesity.
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27
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Folick A, Koliwad SK, Valdearcos M. Microglial Lipid Biology in the Hypothalamic Regulation of Metabolic Homeostasis. Front Endocrinol (Lausanne) 2021; 12:668396. [PMID: 34122343 PMCID: PMC8191416 DOI: 10.3389/fendo.2021.668396] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/16/2021] [Accepted: 05/05/2021] [Indexed: 12/18/2022] Open
Abstract
In mammals, myeloid cells help maintain the homeostasis of peripheral metabolic tissues, and their immunologic dysregulation contributes to the progression of obesity and associated metabolic disease. There is accumulating evidence that innate immune cells also serve as functional regulators within the mediobasal hypothalamus (MBH), a critical brain region controlling both energy and glucose homeostasis. Specifically, microglia, the resident parenchymal myeloid cells of the CNS, play important roles in brain physiology and pathology. Recent studies have revealed an expanding array of microglial functions beyond their established roles as immune sentinels, including roles in brain development, circuit refinement, and synaptic organization. We showed that microglia modulate MBH function by transmitting information resulting from excess nutrient consumption. For instance, microglia can sense the excessive consumption of saturated fats and instruct neurons within the MBH accordingly, leading to responsive alterations in energy balance. Interestingly, the recent emergence of high-resolution single-cell techniques has enabled specific microglial populations and phenotypes to be profiled in unprecedented detail. Such techniques have highlighted specific subsets of microglia notable for their capacity to regulate the expression of lipid metabolic genes, including lipoprotein lipase (LPL), apolipoprotein E (APOE) and Triggering Receptor Expressed on Myeloid Cells 2 (TREM2). The discovery of this transcriptional signature highlights microglial lipid metabolism as a determinant of brain health and disease pathogenesis, with intriguing implications for the treatment of brain disorders and potentially metabolic disease. Here we review our current understanding of how changes in microglial lipid metabolism could influence the hypothalamic control of systemic metabolism.
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Affiliation(s)
- Andrew Folick
- Diabetes Center, University of California, San Francisco, San Francisco, CA, United States
- Department of Medicine, University of California, San Francisco, San Francisco, CA, United States
| | - Suneil K. Koliwad
- Diabetes Center, University of California, San Francisco, San Francisco, CA, United States
- Department of Medicine, University of California, San Francisco, San Francisco, CA, United States
| | - Martin Valdearcos
- Diabetes Center, University of California, San Francisco, San Francisco, CA, United States
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28
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High-fat diet impairs duodenal barrier function and elicits glia-dependent changes along the gut-brain axis that are required for anxiogenic and depressive-like behaviors. J Neuroinflammation 2021; 18:115. [PMID: 33993886 PMCID: PMC8126158 DOI: 10.1186/s12974-021-02164-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Accepted: 04/30/2021] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND Mood and metabolic disorders are interrelated and may share common pathological processes. Autonomic neurons link the brain with the gastrointestinal tract and constitute a likely pathway for peripheral metabolic challenges to affect behaviors controlled by the brain. The activities of neurons along these pathways are regulated by glia, which exhibit phenotypic shifts in response to changes in their microenvironment. How glial changes might contribute to the behavioral effects of consuming a high-fat diet (HFD) is uncertain. Here, we tested the hypothesis that anxiogenic and depressive-like behaviors driven by consuming a HFD involve compromised duodenal barrier integrity and subsequent phenotypic changes to glia and neurons along the gut-brain axis. METHODS C57Bl/6 male mice were exposed to a standard diet or HFD for 20 weeks. Bodyweight was monitored weekly and correlated with mucosa histological damage and duodenal expression of tight junction proteins ZO-1 and occludin at 0, 6, and 20 weeks. The expression of GFAP, TLR-4, BDNF, and DCX were investigated in duodenal myenteric plexus, nodose ganglia, and dentate gyrus of the hippocampus at the same time points. Dendritic spine number was measured in cultured neurons isolated from duodenal myenteric plexuses and hippocampi at weeks 0, 6, and 20. Depressive and anxiety behaviors were also assessed by tail suspension, forced swimming, and open field tests. RESULTS HFD mice exhibited duodenal mucosa damage with marked infiltration of immune cells and decreased expression of ZO-1 and occludin that coincided with increasing body weight. Glial expression of GFAP and TLR4 increased in parallel in the duodenal myenteric plexuses, nodose ganglia, and hippocampus in a time-dependent manner. Glial changes were associated with a progressive decrease in BDNF, and DCX expression, fewer neuronal dendritic spines, and anxiogenic/depressive symptoms in HFD-treated mice. Fluorocitrate (FC), a glial metabolic poison, abolished these effects both in the enteric and central nervous systems and prevented behavioral alterations at week 20. CONCLUSIONS HFD impairs duodenal barrier integrity and produces behavioral changes consistent with depressive and anxiety phenotypes. HFD-driven changes in both peripheral and central nervous systems are glial-dependent, suggesting a potential glial role in the alteration of the gut-brain signaling that occurs during metabolic disorders and psychiatric co-morbidity.
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Microglia-Neuron Crosstalk in Obesity: Melodious Interaction or Kiss of Death? Int J Mol Sci 2021; 22:ijms22105243. [PMID: 34063496 PMCID: PMC8155827 DOI: 10.3390/ijms22105243] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2021] [Revised: 05/11/2021] [Accepted: 05/13/2021] [Indexed: 12/11/2022] Open
Abstract
Diet-induced obesity can originate from the dysregulated activity of hypothalamic neuronal circuits, which are critical for the regulation of body weight and food intake. The exact mechanisms underlying such neuronal defects are not yet fully understood, but a maladaptive cross-talk between neurons and surrounding microglial is likely to be a contributing factor. Functional and anatomical connections between microglia and hypothalamic neuronal cells are at the core of how the brain orchestrates changes in the body's metabolic needs. However, such a melodious interaction may become maladaptive in response to prolonged diet-induced metabolic stress, thereby causing overfeeding, body weight gain, and systemic metabolic perturbations. From this perspective, we critically discuss emerging molecular and cellular underpinnings of microglia-neuron communication in the hypothalamic neuronal circuits implicated in energy balance regulation. We explore whether changes in this intercellular dialogue induced by metabolic stress may serve as a protective neuronal mechanism or contribute to disease establishment and progression. Our analysis provides a framework for future mechanistic studies that will facilitate progress into both the etiology and treatments of metabolic disorders.
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30
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Hypothalamic Microglial Heterogeneity and Signature under High Fat Diet-Induced Inflammation. Int J Mol Sci 2021; 22:ijms22052256. [PMID: 33668314 PMCID: PMC7956484 DOI: 10.3390/ijms22052256] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Revised: 02/18/2021] [Accepted: 02/19/2021] [Indexed: 12/17/2022] Open
Abstract
Under high-fat feeding, the hypothalamus atypically undergoes pro-inflammatory signaling activation. Recent data from transcriptomic analysis of microglia from rodents and humans has allowed the identification of several microglial subpopulations throughout the brain. Numerous studies have clarified the roles of these cells in hypothalamic inflammation, but how each microglial subset plays its functions upon inflammatory stimuli remains unexplored. Fortunately, these data unveiling microglial heterogeneity have triggered the development of novel experimental models for studying the roles and characteristics of each microglial subtype. In this review, we explore microglial heterogeneity in the hypothalamus and their crosstalk with astrocytes under high fat diet-induced inflammation. We present novel currently available ex vivo and in vivo experimental models that can be useful when designing a new research project in this field of study. Last, we examine the transcriptomic data already published to identify how the hypothalamic microglial signature changes upon short-term and prolonged high-fat feeding.
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Mechanisms Underlying the Cognitive and Behavioural Effects of Maternal Obesity. Nutrients 2021; 13:nu13010240. [PMID: 33467657 PMCID: PMC7829712 DOI: 10.3390/nu13010240] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Revised: 01/11/2021] [Accepted: 01/11/2021] [Indexed: 12/14/2022] Open
Abstract
The widespread consumption of 'western'-style diets along with sedentary lifestyles has led to a global epidemic of obesity. Epidemiological, clinical and preclinical evidence suggests that maternal obesity, overnutrition and unhealthy dietary patterns programs have lasting adverse effects on the physical and mental health of offspring. We review currently available preclinical and clinical evidence and summarise possible underlying neurobiological mechanisms by which maternal overnutrition may perturb offspring cognitive function, affective state and psychosocial behaviour, with a focus on (1) neuroinflammation; (2) disrupted neuronal circuities and connectivity; and (3) dysregulated brain hormones. We briefly summarise research implicating the gut microbiota in maternal obesity-induced changes to offspring behaviour. In animal models, maternal obesogenic diet consumption disrupts CNS homeostasis in offspring, which is critical for healthy neurodevelopment, by altering hypothalamic and hippocampal development and recruitment of glial cells, which subsequently dysregulates dopaminergic and serotonergic systems. The adverse effects of maternal obesogenic diets are also conferred through changes to hormones including leptin, insulin and oxytocin which interact with these brain regions and neuronal circuits. Furthermore, accumulating evidence suggests that the gut microbiome may directly and indirectly contribute to these maternal diet effects in both human and animal studies. As the specific pathways shaping abnormal behaviour in offspring in the context of maternal obesogenic diet exposure remain unknown, further investigations are needed to address this knowledge gap. Use of animal models permits investigation of changes in neuroinflammation, neurotransmitter activity and hormones across global brain network and sex differences, which could be directly and indirectly modulated by the gut microbiome.
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