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Abstract
The central nervous system is simply divided into two distinct anatomical regions based on the color of tissues, i.e. the gray and white matter. The gray matter is composed of neuronal cell bodies, glial cells, dendrites, immune cells, and the vascular system, while the white matter is composed of concentrated myelinated axonal fibers extending from neuronal soma and glial cells, such as oligodendrocyte precursor cells (OPCs), oligodendrocytes, astrocytes, and microglia. As neuronal cell bodies are located in the gray matter, great attention has been focused mainly on the gray matter regarding the understanding of the functions of the brain throughout the neurophysiological areas, leading to a scenario in which the function of the white matter is relatively underestimated or has not received much attention. However, increasing evidence shows that the white matter plays highly significant and pivotal functions in the brain based on the fact that its abnormalities are associated with numerous neurological diseases. In this review, we will broadly discuss the pathways and functions of myelination, which is one of the main processes that modulate the functions of the white matter, as well as the manner in which its abnormalities are related to neurological disorders.
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Zilkha-Falb R, Kaushansky N, Ben-Nun A. The Median Eminence, A New Oligodendrogenic Niche in the Adult Mouse Brain. Stem Cell Reports 2020; 14:1076-1092. [PMID: 32413277 PMCID: PMC7355143 DOI: 10.1016/j.stemcr.2020.04.005] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2019] [Revised: 04/15/2020] [Accepted: 04/16/2020] [Indexed: 12/17/2022] Open
Abstract
The subventricular zone (SVZ) of the lateral ventricles and the subgranular zone (SGZ) of the dentate gyrus in the hippocampus are known as neurogenic niches. We show that the median eminence (ME) of the hypothalamus comprises BrdU+ newly proliferating cells co-expressing NG2 (oligodendrocyte progenitors) and RIP (pre-myelinating oligodendrocytes), suggesting their differentiation toward mature oligodendrocytes (OLs). ME cells can generate neurospheres (NS) in vitro, which differentiate mostly to OLs compared with SVZ-NS that typically generate neurons. Interestingly, this population of oligodendrocyte progenitors is increased in the ME from experimental autoimmune encephalomyelitis (EAE)-affected mice. Notably, the thrombospondin 1 (TSP1) expressed by astrocytes, acts as negative regulator of oligodendrogenesis in vitro and is downregulated in the ME of EAE mice. Importantly, transplanted ME-NS preferentially differentiate to MBP+ OLs compared with SVZ-NS in Shiverer mice. Hence, discovering the ME as a new site for myelin-producing cells has a great importance for advising future therapy for demyelinating diseases and spinal cord injury.
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Affiliation(s)
- Rina Zilkha-Falb
- Department of Immunology, The Weizmann Institute of Science, Rehovot, Israel.
| | - Nathali Kaushansky
- Department of Immunology, The Weizmann Institute of Science, Rehovot, Israel
| | - Avraham Ben-Nun
- Department of Immunology, The Weizmann Institute of Science, Rehovot, Israel
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53
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Deng G, Morselli LL, Wagner VA, Balapattabi K, Sapouckey SA, Knudtson KL, Rahmouni K, Cui H, Sigmund CD, Kwitek AE, Grobe JL. Single-Nucleus RNA Sequencing of the Hypothalamic Arcuate Nucleus of C57BL/6J Mice After Prolonged Diet-Induced Obesity. Hypertension 2020; 76:589-597. [PMID: 32507042 DOI: 10.1161/hypertensionaha.120.15137] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Prolonged obesity is associated with blunted feeding and thermogenic autonomic responses to leptin, but cardiovascular responses to leptin are maintained. This state of selective leptin resistance is, therefore, proposed to contribute to the pathogenesis and maintenance of obesity-associated hypertension. Cells of the arcuate nucleus of the hypothalamus detect leptin, and although the cellular and molecular mechanisms remain unclear, altered arcuate nucleus biology is hypothesized to contribute to selective leptin resistance. Male C57BL/6J mice were fed a high-fat diet (HFD) or chow from 8 to 18 weeks of age, as this paradigm models selective leptin resistance. Nuclei were then isolated from arcuate nucleus for single-nucleus RNA sequencing. HFD caused expected gains in adiposity and circulating leptin. Twenty-three unique cell-type clusters were identified, and Ingenuity Pathway Analysis was used to explore changes in gene expression patterns due to chronic HFD within each cluster. Notably, gene expression signatures related to leptin signaling exhibited suppression predominantly in neurons identified as the Agouti-related peptide (Agrp) subtype. Ingenuity Pathway Analysis results were also consistent with alterations in CREB (cAMP response element-binding protein) signaling in Agrp neurons after HFD, and reduced phosphorylated CREB was confirmed in arcuate nucleus after prolonged HFD by capillary electrophoresis-based Western blotting. These findings support the concept that prolonged HFD-induced obesity is associated with selective changes in Agrp neuron biology, possibly secondary to altered CREB signaling.
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Affiliation(s)
- Guorui Deng
- From the Department of Neuroscience and Pharmacology (G.D., S.A.S., K.R., H.C.), University of Iowa
| | - Lisa L Morselli
- Division of Endocrinology, Department of Internal Medicine (L.L.M.), University of Iowa
| | - Valerie A Wagner
- Department of Physiology (V.A.W., K.B., C.D.S., A.E.K., J.L.G.), Medical College of Wisconsin, Milwaukee
| | - Kirthikaa Balapattabi
- Department of Physiology (V.A.W., K.B., C.D.S., A.E.K., J.L.G.), Medical College of Wisconsin, Milwaukee
| | - Sarah A Sapouckey
- From the Department of Neuroscience and Pharmacology (G.D., S.A.S., K.R., H.C.), University of Iowa
| | | | - Kamal Rahmouni
- From the Department of Neuroscience and Pharmacology (G.D., S.A.S., K.R., H.C.), University of Iowa.,Obesity Research and Education Initiative (K.R., H.C.), University of Iowa.,Iowa Neuroscience Institute (K.R., H.C.), University of Iowa
| | - Huxing Cui
- From the Department of Neuroscience and Pharmacology (G.D., S.A.S., K.R., H.C.), University of Iowa.,Obesity Research and Education Initiative (K.R., H.C.), University of Iowa.,Iowa Neuroscience Institute (K.R., H.C.), University of Iowa
| | - Curt D Sigmund
- Department of Physiology (V.A.W., K.B., C.D.S., A.E.K., J.L.G.), Medical College of Wisconsin, Milwaukee.,Cardiovascular Center (C.D.S., A.E.K., J.L.G.), Medical College of Wisconsin, Milwaukee
| | - Anne E Kwitek
- Department of Physiology (V.A.W., K.B., C.D.S., A.E.K., J.L.G.), Medical College of Wisconsin, Milwaukee.,Cardiovascular Center (C.D.S., A.E.K., J.L.G.), Medical College of Wisconsin, Milwaukee.,Department of Medicine (A.E.K.), Medical College of Wisconsin, Milwaukee
| | - Justin L Grobe
- Department of Physiology (V.A.W., K.B., C.D.S., A.E.K., J.L.G.), Medical College of Wisconsin, Milwaukee.,Cardiovascular Center (C.D.S., A.E.K., J.L.G.), Medical College of Wisconsin, Milwaukee.,Department of Biomedical Engineering (J.L.G.), Medical College of Wisconsin, Milwaukee.,Comprehensive Rodent Metabolic Phenotyping Core (J.L.G.), Medical College of Wisconsin, Milwaukee
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54
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A GPR17-cAMP-Lactate Signaling Axis in Oligodendrocytes Regulates Whole-Body Metabolism. Cell Rep 2020; 26:2984-2997.e4. [PMID: 30865888 PMCID: PMC6679936 DOI: 10.1016/j.celrep.2019.02.060] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2018] [Revised: 02/02/2019] [Accepted: 02/14/2019] [Indexed: 12/20/2022] Open
Abstract
The CNS plays a pivotal role in energy homeostasis, but whether oligodendrocytes are involved has been largely unexplored. Here, we show that signaling through GPR17, a G-protein-coupled receptor predominantly expressed in the oligodendrocyte lineage, regulates food intake by modulating hypothalamic neuronal activities. GPR17-null mice and mice with an oligodendrocyte-specific knockout of GPR17 have lean phenotypes on a high-fat diet, suggesting that GPR17 regulates body weight by way of oligodendrocytes. Downregulation of GPR17 results in activation of cAMP-protein kinase A (PKA) signaling in oligodendrocytes and upregulated expression of pyruvate dehydrogenase kinase 1 (PDK1), which promotes lactate production. Elevation of lactate activates AKT and STAT3 signaling in the hypothalamic neurons, leading to increased expression of Pomc and suppression of Agrp. Our findings uncover a critical role of oligodendrocytes in metabolic homeostasis, where GPR17 modulates the production of lactate, which, in turn, acts as a metabolic signal to regulate neuronal activity.
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55
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Du X, Zhang Z, Zhou H, Zhou J. Differential Modulators of NG2-Glia Differentiation into Neurons and Glia and Their Crosstalk. Cell Mol Neurobiol 2020; 41:1-15. [PMID: 32285247 DOI: 10.1007/s10571-020-00843-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2020] [Accepted: 04/06/2020] [Indexed: 02/08/2023]
Abstract
As the fifth main cell population in the brain, NG2-glia are also known as oligodendrocyte precursor cells. NG2-glia express receptors and ion channels for fast modulation of neuronal activities and signaling with neuronal synapses, which are of functional significance in both physiological and pathological states. NG2-glia also participate in fast signaling with peripheral neurons via direct synaptic contacts in the brain. These distinctive glia have the unique capability of proliferating and differentiating into oligodendrocytes, which are critical for axonal myelination in the early developing brain. In neurodegenerative diseases, NG2-glia play an important role and undergo morphological modification, adapt the expression of their membrane receptors and ion channels, and display gene-modulated cell reprogramming and excitotoxicity-caused cell death. These modifications directly and indirectly influence populations of neurons and other glial cells. NG2-glia regulate their action and dynamics in response to neuronal behavior and disease, indicating a critical function to preserve and remodel myelin in physiological states and to repair it in pathological states. Here, we review in detail the differential modulators of NG2-glia into neurons and astrocytes, as well as interactions of NG2-glia with neurons, astrocytes, and microglia. We will also summarize a future potential exploitation of NG2-glia.
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Affiliation(s)
- Xiaohuang Du
- Department of Scientific Research, Army Medical University, Chongqing, 400037, China
| | - Zuo Zhang
- National Drug Clinical Trial Institution, Second Affiliated Hospital, Army Medical University, Chongqing, 400037, China
| | - Hongli Zhou
- National Drug Clinical Trial Institution, Second Affiliated Hospital, Army Medical University, Chongqing, 400037, China
| | - Jiyin Zhou
- National Drug Clinical Trial Institution, Second Affiliated Hospital, Army Medical University, Chongqing, 400037, China.
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56
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Debarba LK, Marangon PB, Borges BC, Veida-Silva H, Venâncio JC, Almeida-Pereira G, Antunes-Rodrigues J, Elias LLK. Neonatal nutritional programming induces gliosis and alters the expression of T-cell protein tyrosine phosphatase and connexins in male rats. Horm Behav 2020; 120:104690. [PMID: 31954709 DOI: 10.1016/j.yhbeh.2020.104690] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/14/2019] [Revised: 12/20/2019] [Accepted: 01/12/2020] [Indexed: 01/17/2023]
Abstract
Changes to neonatal nutrition result in long-lasting impairments in energy balance, which may be described as metabolic programing. Astrocytes, which are interconnected by gap junctions, have emerged as important players in the hypothalamic control of food intake. In order to study the effects of nutritional programming on glial morphology and protein expression, cross-fostered male Wistar rats at postnatal day 3 were assigned to three groups based on litter size: small litter (3 pups per dam, SL), normal litter (10 pups per dam, NL), and large litter (16 pups per dam, LL). Rats from the SL group exhibited higher body weight throughout the study and hyperphagia after weaning. LL animals exhibited hyperphagia, high energy efficiency and catch-up of body weight after weaning. Both the SL and LL groups at postnatal day 60 (PN60) exhibited increased levels of plasma leptin, the Lee index (as an index of obesity), adiposity content, immunoreactivity toward T-cell protein tyrosine phosphatase (TCPTP), and glial fibrillary acidic protein (GFAP) in the arcuate nucleus (ARC) of the hypothalamus. Astrocyte morphology was altered in the ARC of SL and LL animals, and this effect occurred in parallel with a reduction in immunoreactivity toward connexin 30 (CX30). The data obtained demonstrate that both neonatal over- and underfeeding promote not only alterations in the metabolic status but also morphological changes in glial cells in parallel with increasing TCPTP and changes in connexin expression.
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Affiliation(s)
- Lucas Kniess Debarba
- Department of Physiology, Ribeirao Preto Medical School, University of Sao Paulo, Sao Paulo, Brazil. 14049-900.
| | - Paula Beatriz Marangon
- Department of Physiology, Ribeirao Preto Medical School, University of Sao Paulo, Sao Paulo, Brazil. 14049-900
| | - Beatriz C Borges
- Department of Physiology, Ribeirao Preto Medical School, University of Sao Paulo, Sao Paulo, Brazil. 14049-900
| | - Hellen Veida-Silva
- Department of Physiology, Ribeirao Preto Medical School, University of Sao Paulo, Sao Paulo, Brazil. 14049-900
| | - Jade Cabestre Venâncio
- Department of Physiology, Ribeirao Preto Medical School, University of Sao Paulo, Sao Paulo, Brazil. 14049-900
| | - Gislaine Almeida-Pereira
- Department of Physiology, Ribeirao Preto Medical School, University of Sao Paulo, Sao Paulo, Brazil. 14049-900
| | - José Antunes-Rodrigues
- Department of Physiology, Ribeirao Preto Medical School, University of Sao Paulo, Sao Paulo, Brazil. 14049-900
| | - Lucila Leico Kagohara Elias
- Department of Physiology, Ribeirao Preto Medical School, University of Sao Paulo, Sao Paulo, Brazil. 14049-900
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57
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De Luca SN, Miller AA, Sominsky L, Spencer SJ. Microglial regulation of satiety and cognition. J Neuroendocrinol 2020; 32:e12838. [PMID: 32097992 DOI: 10.1111/jne.12838] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/13/2019] [Revised: 01/15/2020] [Accepted: 01/28/2020] [Indexed: 12/11/2022]
Abstract
Microglia have been known for decades as key immune cells that shape the central nervous system (CNS) during development and respond to brain pathogens and injury in adult life. Recent findings now suggest that these cells also play a highly complex role in several other functions of the CNS. In this review, we provide a brief overview of the established microglial functions in development and disease. We also discuss emerging research suggesting that microglia are important for both cognitive function and the regulation of food intake. With respect to cognitive function, current data suggest microglia are not indispensable for neurogenesis, synaptogenesis or cognition in the healthy young adult, although they crucially modulate and support these functions. In doing so, they are likely important in supporting the balance between apoptosis and survival of newborn neurones and in orchestrating appropriate synaptic remodelling in response to a learning stimulus. We also explore the possibility of a role for microglia in feeding and satiety. Microglia have been implicated in both appetite suppression with sickness and obesity and in promoting feeding under some conditions and we discuss these findings here, highlighting the contribution of these cells to healthy brain function.
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Affiliation(s)
- Simone N De Luca
- School of Health and Biomedical Sciences, RMIT University, Melbourne, VIC, Australia
| | - Alyson A Miller
- Institute of Cardiovascular & Medical Sciences, British Heart Foundation Glasgow Cardiovascular Research Centre, University of Glasgow, Glasgow, UK
| | - Luba Sominsky
- School of Health and Biomedical Sciences, RMIT University, Melbourne, VIC, Australia
| | - Sarah J Spencer
- School of Health and Biomedical Sciences, RMIT University, Melbourne, VIC, Australia
- ARC Centre of Excellence for Nanoscale Biophotonics, RMIT University, Melbourne, VIC, Australia
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58
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Haynes VR, Michael NJ, van den Top M, Zhao FY, Brown RD, De Souza D, Dodd GT, Spanswick D, Watt MJ. A Neural basis for Octanoic acid regulation of energy balance. Mol Metab 2020; 34:54-71. [PMID: 32180560 PMCID: PMC7011014 DOI: 10.1016/j.molmet.2020.01.002] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/20/2019] [Revised: 12/11/2019] [Accepted: 01/03/2020] [Indexed: 12/13/2022] Open
Abstract
Objectives Nutrient sensing by hypothalamic neurons is critical for the regulation of food intake and energy expenditure. We aimed to identify long- and medium-chain fatty acid species transported into the brain, their effects on energy balance, and the mechanisms by which they regulate activity of hypothalamic neurons. Methods Simultaneous blood and cerebrospinal fluid (CSF) sampling was undertaken in rats and metabolic analyses using radiolabeled fatty acid tracers were performed on mice. Electrophysiological recording techniques were used to investigate signaling mechanisms underlying fatty acid-induced changes in activity of pro-opiomelanocortin (POMC) neurons. Results Medium-chain fatty acid (MCFA) octanoic acid (C8:0), unlike long-chain fatty acids, was rapidly transported into the hypothalamus of mice and almost exclusively oxidized, causing rapid, transient reductions in food intake and increased energy expenditure. Octanoic acid differentially regulates the excitability of POMC neurons, activating these neurons directly via GPR40 and inducing inhibition via an indirect non-synaptic, purine, and adenosine receptor-dependent mechanism. Conclusions MCFA octanoic acid is a central signaling nutrient that targets POMC neurons via distinct direct and indirect signal transduction pathways to instigate changes in energy status. These results could explain the beneficial health effects that accompany MCFA consumption. Octanoic acid (C8:0) is rapidly transported from blood to the cerebrospinal fluid. Octanoic acid rapidly reduces food intake and increases energy expenditure. Octanoic acid targets POMC neurons through direct and indirect signaling pathways. Activation of POMC neurons occurs directly through GPR40. Inhibition occurs through a nonsynaptic, purine and adenosine receptor-dependent mechanism.
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Affiliation(s)
- Vanessa R Haynes
- Department of Physiology, Faculty of Medicine, Dentistry and Health Sciences, University of Melbourne, Melbourne, 3010, VIC, Australia; Metabolic Disease, Obesity and Diabetes Program, Biomedicine Discovery Institute and the Department of Physiology, Monash University, Clayton, 3800, VIC, Australia
| | - Natalie J Michael
- Metabolic Disease, Obesity and Diabetes Program, Biomedicine Discovery Institute and the Department of Physiology, Monash University, Clayton, 3800, VIC, Australia; Center for Hypothalamic Research, Department of Internal Medicine, UT Southwestern Medical Center, Dallas, TX, 75390, USA
| | | | | | - Russell D Brown
- Metabolic Disease, Obesity and Diabetes Program, Biomedicine Discovery Institute and the Department of Physiology, Monash University, Clayton, 3800, VIC, Australia
| | - David De Souza
- Metabolomics Australia, Bio21 Institute, University of Melbourne, Parkville, 3010, VIC, Australia
| | - Garron T Dodd
- Department of Physiology, Faculty of Medicine, Dentistry and Health Sciences, University of Melbourne, Melbourne, 3010, VIC, Australia
| | - David Spanswick
- Metabolic Disease, Obesity and Diabetes Program, Biomedicine Discovery Institute and the Department of Physiology, Monash University, Clayton, 3800, VIC, Australia; Warwick Medical School, University of Warwick, Coventry, CV4 7AL, UK; NeuroSolutions Ltd, Coventry, UK.
| | - Matthew J Watt
- Department of Physiology, Faculty of Medicine, Dentistry and Health Sciences, University of Melbourne, Melbourne, 3010, VIC, Australia.
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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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60
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Zhang SZ, Wang QQ, Yang QQ, Gu HY, Yin YQ, Li YD, Hou JC, Chen R, Sun QQ, Sun YF, Hu G, Zhou JW. NG2 glia regulate brain innate immunity via TGF-β2/TGFBR2 axis. BMC Med 2019; 17:204. [PMID: 31727112 PMCID: PMC6857135 DOI: 10.1186/s12916-019-1439-x] [Citation(s) in RCA: 69] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Accepted: 10/01/2019] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND Brain innate immunity is vital for maintaining normal brain functions. Immune homeostatic imbalances play pivotal roles in the pathogenesis of neurological diseases including Parkinson's disease (PD). However, the molecular and cellular mechanisms underlying the regulation of brain innate immunity and their significance in PD pathogenesis are still largely unknown. METHODS Cre-inducible diphtheria toxin receptor (iDTR) and diphtheria toxin-mediated cell ablation was performed to investigate the impact of neuron-glial antigen 2 (NG2) glia on the brain innate immunity. RNA sequencing analysis was carried out to identify differentially expressed genes in mouse brain with ablated NG2 glia and lipopolysaccharide (LPS) challenge. Neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-treated mice were used to evaluate neuroinflammatory response in the presence or absence of NG2 glia. The survival of dopaminergic neurons or glial cell activation was evaluated by immunohistochemistry. Co-cultures of NG2 glia and microglia were used to examine the influence of NG2 glia to microglial activation. RESULTS We show that NG2 glia are required for the maintenance of immune homeostasis in the brain via transforming growth factor-β2 (TGF-β2)-TGF-β type II receptor (TGFBR2)-CX3C chemokine receptor 1 (CX3CR1) signaling, which suppresses the activation of microglia. We demonstrate that mice with ablated NG2 glia display a profound downregulation of the expression of microglia-specific signature genes and remarkable inflammatory response in the brain following exposure to endotoxin lipopolysaccharides. Gain- or loss-of-function studies show that NG2 glia-derived TGF-β2 and its receptor TGFBR2 in microglia are key regulators of the CX3CR1-modulated immune response. Furthermore, deficiency of NG2 glia contributes to neuroinflammation and nigral dopaminergic neuron loss in MPTP-induced mouse PD model. CONCLUSIONS These findings suggest that NG2 glia play a critical role in modulation of neuroinflammation and provide a compelling rationale for the development of new therapeutics for neurological disorders.
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Affiliation(s)
- Shu-Zhen Zhang
- Institute of Neuroscience, State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 320 Yueyang Road, Shanghai, 200031, China
| | - Qin-Qin Wang
- Institute of Neuroscience, State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 320 Yueyang Road, Shanghai, 200031, China.,School of Future Technology, University of Chinese Academy of Sciences, Beijing, 100049, China.,Neurobiology Key Laboratory, Jining Medical University, Jining, 272067, Shandong, China
| | - Qiao-Qiao Yang
- Institute of Neuroscience, State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 320 Yueyang Road, Shanghai, 200031, China
| | - Huan-Yu Gu
- Jiangsu Key Laboratory of Neurodegeneration, Department of Pharmacology, Nanjing Medical University, Nanjing, 210029, Jiangsu, China
| | - Yan-Qing Yin
- Institute of Neuroscience, State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 320 Yueyang Road, Shanghai, 200031, China
| | - Yan-Dong Li
- Institute of Neuroscience, State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 320 Yueyang Road, Shanghai, 200031, China
| | - Jin-Can Hou
- Institute of Neuroscience, State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 320 Yueyang Road, Shanghai, 200031, China
| | - Rong Chen
- Institute of Neuroscience, State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 320 Yueyang Road, Shanghai, 200031, China.,School of Future Technology, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Qing-Qing Sun
- Institute of Neuroscience, State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 320 Yueyang Road, Shanghai, 200031, China.,School of Future Technology, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Ying-Feng Sun
- Center for Brain Disorders Research, Center of Parkinson's Disease, Beijing Institute for Brain Disorders, Capital Medical University, Beijing, 100053, China
| | - Gang Hu
- Jiangsu Key Laboratory of Neurodegeneration, Department of Pharmacology, Nanjing Medical University, Nanjing, 210029, Jiangsu, China
| | - Jia-Wei Zhou
- Institute of Neuroscience, State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 320 Yueyang Road, Shanghai, 200031, China. .,School of Future Technology, University of Chinese Academy of Sciences, Beijing, 100049, China. .,Co-innovation Center of Neuroregeneration, School of Medicine, Nantong University, Nantong, 226001, Jiangsu, China. .,Shanghai Center for Brain Science and Brain-Inspired Intelligence Technology, Shanghai, 201210, China.
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Morita-Takemura S, Wanaka A. Blood-to-brain communication in the hypothalamus for energy intake regulation. Neurochem Int 2019; 128:135-142. [DOI: 10.1016/j.neuint.2019.04.007] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2018] [Revised: 04/08/2019] [Accepted: 04/11/2019] [Indexed: 01/03/2023]
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Rosin JM, Kurrasch DM. Emerging roles for hypothalamic microglia as regulators of physiological homeostasis. Front Neuroendocrinol 2019; 54:100748. [PMID: 31059719 DOI: 10.1016/j.yfrne.2019.100748] [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: 02/25/2019] [Revised: 04/24/2019] [Accepted: 05/02/2019] [Indexed: 01/22/2023]
Abstract
The hypothalamus is a crucial brain region that responds to external stressors and functions to maintain physiological homeostatic processes, such as core body temperature and energy balance. The hypothalamus regulates homeostasis by producing hormones that thereby influence the production of other hormones that then control the internal milieu of the body. Microglia are resident macrophages and phagocytic immune cells of the central nervous system (CNS), classically known for surveying the brain's environment, responding to neural insults, and disposing of cellular debris. Recent evidence has shown that microglia are also responsive to external stressors and can influence both the development and function of the hypothalamus in a sex-dependent manner. This emerging microglia-hypothalamic interaction raises the intriguing notion that microglia might play an unappreciated role in hypothalamic control of physiological homeostasis. In this review, we briefly outline how the hypothalamus regulates physiological homeostasis and then describe how this literature overlaps with our understanding of microglia's role in the CNS. We also outline the current literature demonstrating how microglia loss or activation affects the hypothalamus, and ultimately homeostasis. We conclude by proposing how microglia could be key regulators of homeostatic processes by sensing cues external to the CNS and transmitting them through the hypothalamus.
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Affiliation(s)
- Jessica M Rosin
- Department of Medical Genetics, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada; Alberta Children's Hospital Research Institute, University of Calgary, Calgary, Alberta, Canada; Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada
| | - Deborah M Kurrasch
- Department of Medical Genetics, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada; Alberta Children's Hospital Research Institute, University of Calgary, Calgary, Alberta, Canada; Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada.
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Rodríguez-Rodríguez A, Lazcano I, Sánchez-Jaramillo E, Uribe RM, Jaimes-Hoy L, Joseph-Bravo P, Charli JL. Tanycytes and the Control of Thyrotropin-Releasing Hormone Flux Into Portal Capillaries. Front Endocrinol (Lausanne) 2019; 10:401. [PMID: 31293518 PMCID: PMC6603095 DOI: 10.3389/fendo.2019.00401] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Accepted: 06/06/2019] [Indexed: 12/17/2022] Open
Abstract
Central and peripheral mechanisms that modulate energy intake, partition and expenditure determine energy homeostasis. Thyroid hormones (TH) regulate energy expenditure through the control of basal metabolic rate and thermogenesis; they also modulate food intake. TH concentrations are regulated by the hypothalamus-pituitary-thyroid (HPT) axis, and by transport and metabolism in blood and target tissues. In mammals, hypophysiotropic thyrotropin-releasing hormone (TRH) neurons of the paraventricular nucleus of the hypothalamus integrate energy-related information. They project to the external zone of the median eminence (ME), a brain circumventricular organ rich in neuron terminal varicosities and buttons, tanycytes, other glial cells and capillaries. These capillary vessels form a portal system that links the base of the hypothalamus with the anterior pituitary. Tanycytes of the medio-basal hypothalamus express a repertoire of proteins involved in transport, sensing, and metabolism of TH; among them is type 2 deiodinase, a source of 3,3',5-triiodo-L-thyronine necessary for negative feedback on TRH neurons. Tanycytes subtypes are distinguished by position and phenotype. The end-feet of β2-tanycytes intermingle with TRH varicosities and terminals in the external layer of the ME and terminate close to the ME capillaries. Besides type 2 deiodinase, β2-tanycytes express the TRH-degrading ectoenzyme (TRH-DE); this enzyme likely controls the amount of TRH entering portal vessels. TRH-DE is rapidly upregulated by TH, contributing to TH negative feedback on HPT axis. Alterations in energy balance also regulate the expression and activity of TRH-DE in the ME, making β2-tanycytes a hub for energy-related regulation of HPT axis activity. β2-tanycytes also express TRH-R1, which mediates positive effects of TRH on TRH-DE activity and the size of β2-tanycyte end-feet contacts with the basal lamina adjacent to ME capillaries. These end-feet associations with ME capillaries, and TRH-DE activity, appear to coordinately control HPT axis activity. Thus, down-stream of neuronal control of TRH release by action potentials arrival in the external layer of the median eminence, imbricated intercellular processes may coordinate the flux of TRH into the portal capillaries. In conclusion, β2-tanycytes appear as a critical cellular element for the somatic and post-secretory control of TRH flux into portal vessels, and HPT axis regulation in mammals.
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Affiliation(s)
- Adair Rodríguez-Rodríguez
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Mexico
| | - Iván Lazcano
- Departamento de Neurobiología Celular y Molecular, Instituto de Neurobiología, Universidad Nacional Autónoma de México, Juriquilla, Mexico
| | - Edith Sánchez-Jaramillo
- Laboratorio de Neuroendocrinología Molecular, Dirección de Investigaciones en Neurociencias, Instituto Nacional de Psiquiatría Ramón de la Fuente Muñiz, Mexico City, Mexico
| | - Rosa María Uribe
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Mexico
| | - Lorraine Jaimes-Hoy
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Mexico
| | - Patricia Joseph-Bravo
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Mexico
| | - Jean-Louis Charli
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Mexico
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Priming of Hypothalamic Ghrelin Signaling and Microglia Activation Exacerbate Feeding in Rats' Offspring Following Maternal Overnutrition. Nutrients 2019; 11:nu11061241. [PMID: 31159189 PMCID: PMC6627862 DOI: 10.3390/nu11061241] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2019] [Revised: 05/29/2019] [Accepted: 05/29/2019] [Indexed: 12/17/2022] Open
Abstract
Maternal overnutrition during pregnancy leads to metabolic alterations, including obesity, hyperphagia, and inflammation in the offspring. Nutritional priming of central inflammation and its role in ghrelin sensitivity during fed and fasted states have not been analyzed. The current study aims to identify the effect of maternal programming on microglia activation and ghrelin-induced activation of hypothalamic neurons leading to food intake response. We employed a nutritional programming model exposing female Wistar rats to a cafeteria diet (CAF) from pre-pregnancy to weaning. Food intake in male offspring was determined daily after fasting and subcutaneous injection of ghrelin. Hypothalamic ghrelin sensitivity and microglia activation was evaluated using immunodetection for Iba-1 and c-Fos markers, and Western blot for TBK1 signaling. Release of TNF-alpha, IL-6, and IL-1β after stimulation with palmitic, oleic, linoleic acid, or C6 ceramide in primary microglia culture were quantified using ELISA. We found that programmed offspring by CAF diet exhibits overfeeding after fasting and peripheral ghrelin administration, which correlates with an increase in the hypothalamic Iba-1 microglia marker and c-Fos cell activation. Additionally, in contrast to oleic, linoleic, or C6 ceramide stimulation in primary microglia culture, stimulation with palmitic acid for 24 h promotes TNF-alpha, IL-6, and IL-1β release and TBK1 activation. Notably, intracerebroventricular (i.c.v.) palmitic acid or LPS inoculation for five days promotes daily increase in food intake and food consumption after ghrelin administration. Finally, we found that i.c.v. palmitic acid substantially activates hypothalamic Iba-1 microglia marker and c-Fos. Together, our results suggest that maternal nutritional programing primes ghrelin sensitivity and microglia activation, which potentially might mirror hypothalamic administration of the saturated palmitic acid.
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Yoo S, Cha D, Kim DW, Hoang TV, Blackshaw S. Tanycyte-Independent Control of Hypothalamic Leptin Signaling. Front Neurosci 2019; 13:240. [PMID: 30941008 PMCID: PMC6433882 DOI: 10.3389/fnins.2019.00240] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2019] [Accepted: 03/01/2019] [Indexed: 12/29/2022] Open
Abstract
Leptin is secreted by adipocytes to regulate appetite and body weight. Recent studies have reported that tanycytes actively transport circulating leptin across the brain barrier into the hypothalamus, and are required for normal levels of hypothalamic leptin signaling. However, direct evidence for leptin receptor (LepR) expression is lacking, and the effect of tanycyte-specific deletion of LepR has not been investigated. In this study, we analyze the expression and function of the tanycytic LepR in mice. Using single-molecule fluorescent in situ hybridization (smfISH), RT-qPCR, single-cell RNA sequencing (scRNA-Seq), and selective deletion of the LepR in tanycytes, we are unable to detect expression of LepR in the tanycytes. Tanycyte-specific deletion of LepR likewise did not affect leptin-induced pSTAT3 expression in hypothalamic neurons, regardless of whether leptin was delivered by intraperitoneal or intracerebroventricular injection. Finally, we use activity-regulated scRNA-Seq (act-Seq) to comprehensively profile leptin-induced changes in gene expression in all cell types in mediobasal hypothalamus. Clear evidence for leptin signaling is only seen in endothelial cells and subsets of neurons, although virtually all cell types show leptin-induced changes in gene expression. We thus conclude that LepR expression in tanycytes is either absent or undetectably low, that tanycytes do not directly regulate hypothalamic leptin signaling through a LepR-dependent mechanism, and that leptin regulates gene expression in diverse hypothalamic cell types through both direct and indirect mechanisms.
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Affiliation(s)
- Sooyeon Yoo
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University, Baltimore, MD, United States
| | - David Cha
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University, Baltimore, MD, United States
| | - Dong Won Kim
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University, Baltimore, MD, United States
| | - Thanh V Hoang
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University, Baltimore, MD, United States
| | - Seth Blackshaw
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University, Baltimore, MD, United States.,Department of Ophthalmology, Johns Hopkins University, Baltimore, MD, United States.,Department of Neurology, Johns Hopkins University, Baltimore, MD, United States.,Center for Human Systems Biology, Johns Hopkins University, Baltimore, MD, United States.,School of Medicine, Institute for Cell Engineering, Johns Hopkins University, Baltimore, MD, United States
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66
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Cakir I, Nillni EA. Endoplasmic Reticulum Stress, the Hypothalamus, and Energy Balance. Trends Endocrinol Metab 2019; 30:163-176. [PMID: 30691778 DOI: 10.1016/j.tem.2019.01.002] [Citation(s) in RCA: 62] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/01/2018] [Revised: 12/17/2018] [Accepted: 01/03/2019] [Indexed: 01/09/2023]
Abstract
Overweight and obesity pose significant health problems globally, and are causatively linked to metabolic dysregulation. The hypothalamus integrates neural, nutritional, and hormonal cues to regulate homeostasis, including circadian rhythm, body temperature, thirst, food intake, energy expenditure, and glucose metabolism. Hypothalamic neuropeptides play a fundamental role in these processes. Studies during the past two decades suggest a role of central endoplasmic reticulum (ER) stress in the pathophysiology of obesity. This review covers recent findings on the role of ER stress and neuropeptide processing in the central regulation of energy homeostasis, with special emphasis on proopiomelanocortin (POMC)-encoding neurons. In addition, the role of neuroinflammation in the context of obesity is briefly discussed.
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Affiliation(s)
- Isin Cakir
- Life Sciences Institute, University of Michigan, Ann Arbor, MI 48109, USA
| | - Eduardo A Nillni
- Department of Medicine, Molecular Biology, Cell Biology, and Biochemistry, Brown University, Providence, RI 02912, USA.
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67
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De Luca SN, Sominsky L, Soch A, Wang H, Ziko I, Rank MM, Spencer SJ. Conditional microglial depletion in rats leads to reversible anorexia and weight loss by disrupting gustatory circuitry. Brain Behav Immun 2019; 77:77-91. [PMID: 30578932 DOI: 10.1016/j.bbi.2018.12.008] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/01/2018] [Revised: 12/04/2018] [Accepted: 12/12/2018] [Indexed: 01/12/2023] Open
Abstract
Microglia are highly sensitive to dietary influence, becoming activated acutely and long-term by high fat diet. However, their role in regulating satiety and feeding in healthy individuals remains unclear. Here we show that microglia are essential for the normal regulation of satiety and metabolism in rats. Short-term microglial depletion in a Cx3cr1-Dtr rat led to a dramatic weight loss that was largely accounted for by an acute reduction in food intake. This weight loss and anorexia were not likely due to a sickness response since the rats did not display peripheral or central inflammation, withdrawal, anxiety-like behavior, or nausea-associated pica. Hormonal and hypothalamic anatomical changes were largely compensatory to the suppressed food intake, which occurred in association with disruption of the gustatory circuitry at the paraventricular nucleus of the thalamus. Thus, microglia are important in supporting normal feeding behaviors and weight, and regulating preference for palatable food. Inhibiting this circuitry is able to over-ride strong compensatory drives to eat, providing a potential target for satiety control.
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Affiliation(s)
- Simone N De Luca
- School of Health and Biomedical Sciences, RMIT University, Melbourne, Vic. 3138, Australia
| | - Luba Sominsky
- School of Health and Biomedical Sciences, RMIT University, Melbourne, Vic. 3138, Australia
| | - Alita Soch
- School of Health and Biomedical Sciences, RMIT University, Melbourne, Vic. 3138, Australia
| | - Hao Wang
- School of Health and Biomedical Sciences, RMIT University, Melbourne, Vic. 3138, Australia
| | - Ilvana Ziko
- School of Health and Biomedical Sciences, RMIT University, Melbourne, Vic. 3138, Australia
| | - Michelle M Rank
- School of Health and Biomedical Sciences, RMIT University, Melbourne, Vic. 3138, Australia
| | - Sarah J Spencer
- School of Health and Biomedical Sciences, RMIT University, Melbourne, Vic. 3138, Australia.
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Rodríguez E, Guerra M, Peruzzo B, Blázquez JL. Tanycytes: A rich morphological history to underpin future molecular and physiological investigations. J Neuroendocrinol 2019; 31:e12690. [PMID: 30697830 DOI: 10.1111/jne.12690] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/14/2018] [Revised: 01/21/2019] [Accepted: 01/22/2019] [Indexed: 01/04/2023]
Abstract
Tanycytes are located at the base of the brain and retain characteristics from their developmental origins, such as radial glial cells, throughout their life span. With transport mechanisms and modulation of tight junction proteins, tanycytes form a bridge connecting the cerebrospinal fluid with the external limiting basement membrane. They also retain the powers of self-renewal and can differentiate to generate neurones and glia. Similar to radial glia, they are a heterogeneous family with distinct phenotypes. Although the four subtypes so far distinguished display distinct characteristics, further research is likely to reveal new subtypes. In this review, we have re-visited the work of the pioneers in the field, revealing forgotten work that is waiting to inspire new research with today's cutting-edge technologies. We have conducted a systematic ultrastructural study of α-tanycytes that resulted in a wealth of new information, generating numerous questions for future study. We also consider median eminence pituicytes, a closely-related cell type to tanycytes, and attempt to relate pituicyte fine morphology to molecular and functional mechanism. Our rationale was that future research should be guided by a better understanding of the early pioneering work in the field, which may currently be overlooked when interpreting newer data or designing new investigations.
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Affiliation(s)
- Esteban Rodríguez
- Facultad de Medicina, Instituto de Anatomía, Histología y Patología, Universidad Austral de Chile, Valdivia, Chile
| | - Montserrat Guerra
- Facultad de Medicina, Instituto de Anatomía, Histología y Patología, Universidad Austral de Chile, Valdivia, Chile
| | - Bruno Peruzzo
- Facultad de Medicina, Instituto de Anatomía, Histología y Patología, Universidad Austral de Chile, Valdivia, Chile
| | - Juan Luis Blázquez
- Departamento de Anatomía e Histología Humanas, Facultad de Medicina, Universidad de Salamanca, Salamanca, Spain
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Debarba LK, Vechiato FMV, Veida-Silva H, Borges BC, Jamur MC, Antunes-Rodrigues J, Elias LLK. The role of TCPTP on leptin effects on astrocyte morphology. Mol Cell Endocrinol 2019; 482:62-69. [PMID: 30572001 DOI: 10.1016/j.mce.2018.12.010] [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: 09/08/2018] [Revised: 11/25/2018] [Accepted: 12/15/2018] [Indexed: 12/19/2022]
Abstract
Leptin and LPS has been implicated in the development of hypothalamic astrogliosis in rodents. Astrocytes, which are interconnected by gap junction proteins, have emerged as important players in the control of energy homeostasis exerted by the hypothalamus. To investigate the hypothesis of action of T-cell protein tyrosine phosphatase (TCPTP) on the astrocyte morphology, astrocytes from the hypothalamus of one-day-old rats were stimulated with leptin and LPS (used as a positive control). Leptin and LPS induced a marked increase in astrocyte size, an increase in Ptpn2 (TCPTP gene) and gap junction alpha-1 protein, - Gja1 (connexin 43 - CX43 gene) mRNA expression and a decrease in gap junction protein, alpha 6 - Gja6 (CX30 gene) mRNA expression. Remarkably, these effects on astrocytes morphology and connexins were prevented by Ptpn2 siRNA. Astrocytes are known to produce cytokines; here we show that TCPTP acts as an important regulator of the cytokines and it possesses a reciprocal interplay with protein tyrosine phosphatase 1B (PTP1B). Our findings demonstrate that leptin and LPS alter astrocyte morphology by increasing TCPTP, which in turn modulates connexin 30 (CX30) and connexin 43 (CX43) expression. TCPTP and PTP1B seem to act in the regulation of cytokine production in astrocytes.
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Affiliation(s)
- Lucas Kniess Debarba
- Department of Physiology, Ribeirao Preto Medical School, University of Sao Paulo, Sao Paulo, Brazil.
| | | | - Hellen Veida-Silva
- Department of Physiology, Ribeirao Preto Medical School, University of Sao Paulo, Sao Paulo, Brazil
| | - Beatriz C Borges
- Department of Physiology, Ribeirao Preto Medical School, University of Sao Paulo, Sao Paulo, Brazil
| | - Maria Célia Jamur
- Department of Cell and Molecular Biology and Pathogenic Bioagents, Ribeirao Preto Medical School, University of Sao Paulo, Sao Paulo, 14049-900, Brazil
| | - José Antunes-Rodrigues
- Department of Physiology, Ribeirao Preto Medical School, University of Sao Paulo, Sao Paulo, Brazil
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Marek V, Potey A, Réaux-Le-Goazigo A, Reboussin E, Charbonnier A, Villette T, Baudouin C, Rostène W, Denoyer A, Mélik Parsadaniantz S. Blue light exposure in vitro causes toxicity to trigeminal neurons and glia through increased superoxide and hydrogen peroxide generation. Free Radic Biol Med 2019; 131:27-39. [PMID: 30496813 DOI: 10.1016/j.freeradbiomed.2018.11.029] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/17/2018] [Revised: 11/22/2018] [Accepted: 11/22/2018] [Indexed: 01/08/2023]
Abstract
Today the noxiousness of blue light from natural and particularly artificial (fluorescent tubes, LED panels, visual displays) sources is actively discussed in the context of various ocular diseases. Many of them have an important neurologic component and are associated with ocular pain. This neuropathic signal is provided by nociceptive neurons from trigeminal ganglia. However, the phototoxicity of blue light on trigeminal neurons has not been explored so far. The aim of the present in vitro study was to investigate the cytotoxic impact of various wavebands of visible light (410-630 nm) on primary cell culture of mouse trigeminal neural and glial cells. Three-hour exposure to narrow wavebands of blue light centered at 410, 440 and 480 nm of average 1.1 mW/cm2 irradiance provoked cell death, altered cell morphology and induced oxidative stress and inflammation. These effects were not observed for other tested visible wavebands. We observed that neurons and glial cells processed the light signal in different manner, in terms of resulting superoxide and hydrogen peroxide generation, inflammatory biomarkers expression and phototoxic mitochondrial damage. We analyzed the pathways of photic signal reception, and we proposed that, in trigeminal cells, in addition to widely known mitochondria-mediated light absorption, light could be received by means of non-visual opsins, melanopsin (opn4) and neuropsin (opn5). We also investigated the mechanisms underlying the observed phototoxicity, further suggesting an important role of the endoplasmic reticulum in neuronal transmission of blue-light-toxic message. Taken together, our results give some insight into circuit of tangled pain and photosensitivity frequently observed in patients consulting for these ocular symptoms.
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Affiliation(s)
- V Marek
- R&D, Essilor International, Paris, France; Sorbonne Université, INSERM, CNRS, Institut de la Vision, Paris, France.
| | - A Potey
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, Paris, France
| | | | - E Reboussin
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, Paris, France
| | - A Charbonnier
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, Paris, France
| | - T Villette
- R&D, Essilor International, Paris, France
| | - C Baudouin
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, Paris, France; Centre Hospitalier Nationale d'Ophtalmologie des Quinze-Vingts, Paris, France; Versailles-Saint-Quentin-en-Yvelines Université, Versailles, France
| | - W Rostène
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, Paris, France
| | - A Denoyer
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, Paris, France; Centre Hospitalier Nationale d'Ophtalmologie des Quinze-Vingts, Paris, France; CHU Robert Debré, Université Reims Champagne-Ardenne, Reims, France
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Langlet F. Tanycyte Gene Expression Dynamics in the Regulation of Energy Homeostasis. Front Endocrinol (Lausanne) 2019; 10:286. [PMID: 31133987 PMCID: PMC6514105 DOI: 10.3389/fendo.2019.00286] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/25/2019] [Accepted: 04/18/2019] [Indexed: 01/01/2023] Open
Abstract
Animal survival relies on a constant balance between energy supply and energy expenditure, which is controlled by several neuroendocrine functions that integrate metabolic information and adapt the response of the organism to physiological demands. Polarized ependymoglial cells lining the floor of the third ventricle and sending a single process within metabolic hypothalamic parenchyma, tanycytes are henceforth described as key components of the hypothalamic neural network controlling energy balance. Their strategic position and peculiar properties convey them diverse physiological functions ranging from blood/brain traffic controllers, metabolic modulators, and neural stem/progenitor cells. At the molecular level, these functions rely on an accurate regulation of gene expression. Indeed, tanycytes are characterized by their own molecular signature which is mostly associated to their diverse physiological functions, and the detection of variations in nutrient/hormone levels leads to an adequate modulation of genetic profile in order to ensure energy homeostasis. The aim of this review is to summarize recent knowledge on the nutritional control of tanycyte gene expression.
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Roujeau C, Jockers R, Dam J. Endospanin 1 Determines the Balance of Leptin-Regulated Hypothalamic Functions. Neuroendocrinology 2019; 108:132-141. [PMID: 30326479 DOI: 10.1159/000494557] [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: 07/21/2018] [Accepted: 10/16/2018] [Indexed: 11/19/2022]
Abstract
Endospanin 1 (Endo1), a protein encoded in humans by the same gene than the leptin receptor (ObR), and increased by diet-induced obesity, is an important regulator of ObR trafficking and cell surface exposure, determining leptin signaling strength. Defective intracellular trafficking of the leptin receptor to the neuronal plasma membrane has been proposed as a mechanism underlying the development of leptin resistance observed in human obesity. More recently, Endo1 has emerged as a mediator of "selective leptin resistance." The underlying mechanisms of the latter are not completely understood, but the possibility of differential activation of leptin signaling pathways was suggested among others. In this respect, the expression level of Endo1 is crucial for the appropriate balance between different leptin signaling pathways and leptin functions in the hypothalamus and is likely participating in selective leptin resistance for the control of energy and glucose homeostasis.
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Affiliation(s)
- Clara Roujeau
- Inserm U1016, CNRS UMR 8104, Institut Cochin, Université Paris Descartes, Sorbonne Paris Cité, Paris, France
| | - Ralf Jockers
- Inserm U1016, CNRS UMR 8104, Institut Cochin, Université Paris Descartes, Sorbonne Paris Cité, Paris, France
| | - Julie Dam
- Inserm U1016, CNRS UMR 8104, Institut Cochin, Université Paris Descartes, Sorbonne Paris Cité, Paris,
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Rahman MH, Kim MS, Lee IK, Yu R, Suk K. Interglial Crosstalk in Obesity-Induced Hypothalamic Inflammation. Front Neurosci 2018; 12:939. [PMID: 30618568 PMCID: PMC6300514 DOI: 10.3389/fnins.2018.00939] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2018] [Accepted: 11/29/2018] [Indexed: 12/29/2022] Open
Abstract
Glial cells have recently gained particular attention for their close involvement in neuroinflammation and metabolic disorders including obesity and diabetes. In the central nervous system (CNS), different types of resident glial cells have been documented to express several signaling molecules and related receptors, and their crosstalks have been implicated in physiology and pathology of the CNS. Emerging evidence illustrates that malfunctioning glia and their products are an important component of hypothalamic inflammation. Recent studies have suggested that glia–glia crosstalk is a pivotal mechanism of overnutrition-induced chronic hypothalamic inflammation, which might be intrinsically associated with obesity/diabetes and their pathological consequences. This review covers the recent advances in the molecular aspects of interglial crosstalk in hypothalamic inflammation, proposing a central role of such a crosstalk in the development of obesity, diabetes, and related complications. Finally, we discuss the possibilities and challenges of targeting glial cells and their crosstalk for a better understanding of hypothalamic inflammation and related metabolic dysfunctions.
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Affiliation(s)
- Md Habibur Rahman
- Department of Pharmacology, Brain Science and Engineering Institute, BK21 Plus KNU Biomedical Convergence Program, School of Medicine, Kyungpook National University, Daegu, South Korea
| | - Min-Seon Kim
- Division of Endocrinology and Metabolism, University of Ulsan College of Medicine, Seoul, South Korea
| | - In-Kyu Lee
- Department of Internal Medicine, Division of Endocrinology and Metabolism, School of Medicine, Kyungpook National University, Daegu, South Korea
| | - Rina Yu
- Department of Food Science and Nutrition, University of Ulsan, Ulsan, South Korea
| | - Kyoungho Suk
- Department of Pharmacology, Brain Science and Engineering Institute, BK21 Plus KNU Biomedical Convergence Program, School of Medicine, Kyungpook National University, Daegu, South Korea
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Bentivoglio M, Kristensson K, Rottenberg ME. Circumventricular Organs and Parasite Neurotropism: Neglected Gates to the Brain? Front Immunol 2018; 9:2877. [PMID: 30619260 PMCID: PMC6302769 DOI: 10.3389/fimmu.2018.02877] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2018] [Accepted: 11/22/2018] [Indexed: 12/20/2022] Open
Abstract
Circumventricular organs (CVOs), neural structures located around the third and fourth ventricles, harbor, similarly to the choroid plexus, vessels devoid of a blood-brain barrier (BBB). This enables them to sense immune-stimulatory molecules in the blood circulation, but may also increase chances of exposure to microbes. In spite of this, attacks to CVOs by microbes are rarely described. It is here highlighted that CVOs and choroid plexus can be infected by pathogens circulating in the bloodstream, providing a route for brain penetration, as shown by infections with the parasites Trypanosoma brucei. Immune responses elicited by pathogens or systemic infections in the choroid plexus and CVOs are briefly outlined. From the choroid plexus trypanosomes can seed into the ventricles and initiate accelerated infiltration of T cells and parasites in periventricular areas. The highly motile trypanosomes may also enter the brain parenchyma from the median eminence, a CVO located at the base of the third ventricle, by crossing the border into the BBB-protected hypothalamic arcuate nuclei. A gate may, thus, be provided for trypanosomes to move into brain areas connected to networks of regulation of circadian rhythms and sleep-wakefulness, to which other CVOs are also connected. Functional imbalances in these networks characterize human African trypanosomiasis, also called sleeping sickness. They are distinct from the sickness response to bacterial infections, but can occur in common neuropsychiatric diseases. Altogether the findings lead to the question: does the neglect in reporting microbe attacks to CVOs reflect lack of awareness in investigations or of gate-opening capability by microbes?
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Affiliation(s)
- Marina Bentivoglio
- Department of Neuroscience Biomedicine and Movement Sciences, University of Verona, Verona, Italy
| | | | - Martin E. Rottenberg
- Department Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden
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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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76
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Abstract
Animal models are valuable for the study of complex behaviours and physiology such as the control of appetite because genetic, pharmacological and surgical approaches allow the investigation of underlying mechanisms. However, the majority of such studies are carried out in just two species, laboratory mice and rats. These conventional laboratory species have been intensely selected for high growth rate and fecundity, and have a high metabolic rate and short lifespan. These aspects limit their translational relevance for human appetite control. This review will consider the value of studies carried out in a seasonal species, the Siberian hamster, which shows natural photoperiod-regulated annual cycles in appetite, growth and fattening. Such studies reveal that this long-term control is not simply an adjustment of the known hypothalamic neuronal systems that control hunger and satiety in the short term. Long-term cyclicity is probably driven by hypothalamic tanycytes, glial cells that line the ventricular walls of the hypothalamus. These unique cells sense nutrients and metabolic hormones, integrate seasonal signals and effect plasticity of surrounding neural circuits through their function as a stem cell niche in the adult. Studies of glial cell function in the hypothalamus offer new potential for identifying central targets for appetite and body weight control amenable to dietary or pharmacological manipulation.
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77
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Fluorescent blood-brain barrier tracing shows intact leptin transport in obese mice. Int J Obes (Lond) 2018; 43:1305-1318. [PMID: 30283080 PMCID: PMC6760579 DOI: 10.1038/s41366-018-0221-z] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Revised: 07/20/2018] [Accepted: 09/02/2018] [Indexed: 12/13/2022]
Abstract
Background/objectives Individuals carrying loss-of-function gene mutations for the adipocyte hormone leptin are morbidly obese, but respond favorably to replacement therapy. Recombinant leptin is however largely ineffective for the vast majority of obese individuals due to leptin resistance. One theory underlying leptin resistance is impaired leptin transport across the blood–brain-barrier (BBB). Here, we aim to gain new insights into the mechanisms of leptin BBB transport, and its role in leptin resistance. Methods We developed a novel tool for visualizing leptin transport using infrared fluorescently labeled leptin, combined with tissue clearing and light-sheet fluorescence microscopy. We corroborated these data using western blotting. Results Using 3D whole brain imaging, we display comparable leptin accumulation in circumventricular organs of lean and obese mice, predominantly in the choroid plexus (CP). Protein quantification revealed comparable leptin levels in microdissected mediobasal hypothalami (MBH) of lean and obese mice (p = 0.99). We further found increased leptin receptor expression in the CP (p = 0.025, p = 0.0002) and a trend toward elevated leptin protein levels in the MBH (p = 0.17, p = 0.078) of obese mice undergoing weight loss interventions by calorie restriction or exendin-4 treatment. Conclusions Overall, our findings suggest a crucial role for the CP in controlling the transport of leptin into the cerebrospinal fluid and from there to target areas such as the MBH, potentially mediated via the leptin receptor. Similar leptin levels in circumventricular organs and the MBH of lean and obese mice further suggest intact leptin BBB transport in leptin resistant mice.
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78
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Abstract
Neuron-glia antigen 2-expressing glial cells (NG2 glia) serve as oligodendrocyte progenitors during development and adulthood. However, recent studies have shown that these cells represent not only a transitional stage along the oligodendroglial lineage, but also constitute a specific cell type endowed with typical properties and functions. Namely, NG2 glia (or subsets of NG2 glia) establish physical and functional interactions with neurons and other central nervous system (CNS) cell types, that allow them to constantly monitor the surrounding neuropil. In addition to operating as sensors, NG2 glia have features that are expected for active modulators of neuronal activity, including the expression and release of a battery of neuromodulatory and neuroprotective factors. Consistently, cell ablation strategies targeting NG2 glia demonstrate that, beyond their role in myelination, these cells contribute to CNS homeostasis and development. In this review, we summarize and discuss the advancements achieved over recent years toward the understanding of such functions, and propose novel approaches for further investigations aimed at elucidating the multifaceted roles of NG2 glia.
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79
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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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80
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Prevot V, Dehouck B, Sharif A, Ciofi P, Giacobini P, Clasadonte J. The Versatile Tanycyte: A Hypothalamic Integrator of Reproduction and Energy Metabolism. Endocr Rev 2018; 39:333-368. [PMID: 29351662 DOI: 10.1210/er.2017-00235] [Citation(s) in RCA: 147] [Impact Index Per Article: 24.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/01/2017] [Accepted: 01/12/2018] [Indexed: 12/16/2022]
Abstract
The fertility and survival of an individual rely on the ability of the periphery to promptly, effectively, and reproducibly communicate with brain neural networks that control reproduction, food intake, and energy homeostasis. Tanycytes, a specialized glial cell type lining the wall of the third ventricle in the median eminence of the hypothalamus, appear to act as the linchpin of these processes by dynamically controlling the secretion of neuropeptides into the portal vasculature by hypothalamic neurons and regulating blood-brain and blood-cerebrospinal fluid exchanges, both processes that depend on the ability of these cells to adapt their morphology to the physiological state of the individual. In addition to their barrier properties, tanycytes possess the ability to sense blood glucose levels, and play a fundamental and active role in shuttling circulating metabolic signals to hypothalamic neurons that control food intake. Moreover, accumulating data suggest that, in keeping with their putative descent from radial glial cells, tanycytes are endowed with neural stem cell properties and may respond to dietary or reproductive cues by modulating hypothalamic neurogenesis. Tanycytes could thus constitute the missing link in the loop connecting behavior, hormonal changes, signal transduction, central neuronal activation and, finally, behavior again. In this article, we will examine these recent advances in the understanding of tanycytic plasticity and function in the hypothalamus and the underlying molecular mechanisms. We will also discuss the putative involvement and therapeutic potential of hypothalamic tanycytes in metabolic and fertility disorders.
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Affiliation(s)
- Vincent Prevot
- Inserm, Laboratory of Development and Plasticity of the Neuroendocrine Brain, Jean-Pierre Aubert Research Center, Lille, France.,University of Lille, FHU 1000 Days for Health, School of Medicine, Lille, France
| | - Bénédicte Dehouck
- Inserm, Laboratory of Development and Plasticity of the Neuroendocrine Brain, Jean-Pierre Aubert Research Center, Lille, France.,University of Lille, FHU 1000 Days for Health, School of Medicine, Lille, France
| | - Ariane Sharif
- Inserm, Laboratory of Development and Plasticity of the Neuroendocrine Brain, Jean-Pierre Aubert Research Center, Lille, France.,University of Lille, FHU 1000 Days for Health, School of Medicine, Lille, France
| | - Philippe Ciofi
- Inserm, Neurocentre Magendie, Bordeaux, France.,Université de Bordeaux, Bordeaux, France
| | - Paolo Giacobini
- Inserm, Laboratory of Development and Plasticity of the Neuroendocrine Brain, Jean-Pierre Aubert Research Center, Lille, France.,University of Lille, FHU 1000 Days for Health, School of Medicine, Lille, France
| | - Jerome Clasadonte
- Inserm, Laboratory of Development and Plasticity of the Neuroendocrine Brain, Jean-Pierre Aubert Research Center, Lille, France.,University of Lille, FHU 1000 Days for Health, School of Medicine, Lille, France
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81
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Xu C, Messina A, Somm E, Miraoui H, Kinnunen T, Acierno J, Niederländer NJ, Bouilly J, Dwyer AA, Sidis Y, Cassatella D, Sykiotis GP, Quinton R, De Geyter C, Dirlewanger M, Schwitzgebel V, Cole TR, Toogood AA, Kirk JM, Plummer L, Albrecht U, Crowley WF, Mohammadi M, Tena-Sempere M, Prevot V, Pitteloud N. KLB, encoding β-Klotho, is mutated in patients with congenital hypogonadotropic hypogonadism. EMBO Mol Med 2018; 9:1379-1397. [PMID: 28754744 PMCID: PMC5623842 DOI: 10.15252/emmm.201607376] [Citation(s) in RCA: 60] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Congenital hypogonadotropic hypogonadism (CHH) is a rare genetic form of isolated gonadotropin‐releasing hormone (GnRH) deficiency caused by mutations in > 30 genes. Fibroblast growth factor receptor 1 (FGFR1) is the most frequently mutated gene in CHH and is implicated in GnRH neuron development and maintenance. We note that a CHH FGFR1 mutation (p.L342S) decreases signaling of the metabolic regulator FGF21 by impairing the association of FGFR1 with β‐Klotho (KLB), the obligate co‐receptor for FGF21. We thus hypothesized that the metabolic FGF21/KLB/FGFR1 pathway is involved in CHH. Genetic screening of 334 CHH patients identified seven heterozygous loss‐of‐function KLB mutations in 13 patients (4%). Most patients with KLB mutations (9/13) exhibited metabolic defects. In mice, lack of Klb led to delayed puberty, altered estrous cyclicity, and subfertility due to a hypothalamic defect associated with inability of GnRH neurons to release GnRH in response to FGF21. Peripheral FGF21 administration could indeed reach GnRH neurons through circumventricular organs in the hypothalamus. We conclude that FGF21/KLB/FGFR1 signaling plays an essential role in GnRH biology, potentially linking metabolism with reproduction.
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Affiliation(s)
- Cheng Xu
- Service of Endocrinology, Diabetology & Metabolism, Lausanne University Hospital, Lausanne, Switzerland
| | - Andrea Messina
- Service of Endocrinology, Diabetology & Metabolism, Lausanne University Hospital, Lausanne, Switzerland
| | - Emmanuel Somm
- Service of Endocrinology, Diabetology & Metabolism, Lausanne University Hospital, Lausanne, Switzerland
| | - Hichem Miraoui
- Service of Endocrinology, Diabetology & Metabolism, Lausanne University Hospital, Lausanne, Switzerland
| | - Tarja Kinnunen
- Department of Biology, School of Applied Sciences, University of Huddersfield, Huddersfield, UK
| | - James Acierno
- Service of Endocrinology, Diabetology & Metabolism, Lausanne University Hospital, Lausanne, Switzerland
| | - Nicolas J Niederländer
- Service of Endocrinology, Diabetology & Metabolism, Lausanne University Hospital, Lausanne, Switzerland
| | - Justine Bouilly
- Service of Endocrinology, Diabetology & Metabolism, Lausanne University Hospital, Lausanne, Switzerland
| | - Andrew A Dwyer
- Service of Endocrinology, Diabetology & Metabolism, Lausanne University Hospital, Lausanne, Switzerland.,University of Lausanne Institute of Higher Education and Research in Healthcare, Lausanne, Switzerland
| | - Yisrael Sidis
- Service of Endocrinology, Diabetology & Metabolism, Lausanne University Hospital, Lausanne, Switzerland
| | - Daniele Cassatella
- Service of Endocrinology, Diabetology & Metabolism, Lausanne University Hospital, Lausanne, Switzerland
| | - Gerasimos P Sykiotis
- Service of Endocrinology, Diabetology & Metabolism, Lausanne University Hospital, Lausanne, Switzerland
| | - Richard Quinton
- Institute for Genetic Medicine, University of Newcastle-on-Tyne, Newcastle-on Tyne, UK
| | - Christian De Geyter
- Clinic of Gynecological Endocrinology and Reproductive Medicine, University Hospital, University of Basel, Basel, Switzerland
| | - Mirjam Dirlewanger
- Pediatric Endocrine and Diabetes Unit, Children's Hospital, University Hospitals and Faculty of Medicine, Geneva, Switzerland
| | - Valérie Schwitzgebel
- Pediatric Endocrine and Diabetes Unit, Children's Hospital, University Hospitals and Faculty of Medicine, Geneva, Switzerland
| | - Trevor R Cole
- Department of Clinical Genetics, Birmingham Women's Hospital, Birmingham, UK
| | - Andrew A Toogood
- Department of Endocrinology, Queen Elizabeth Hospital, University Hospitals Birmingham, Birmingham, UK
| | - Jeremy Mw Kirk
- Department of Endocrinology, Birmingham Children's Hospital, Birmingham, UK
| | - Lacey Plummer
- National Center for Translational Research in Reproduction and Infertility, Harvard Reproductive Endocrine Sciences Center of the Department of Medicine, Massachusetts General Hospital, Boston, MA, USA
| | - Urs Albrecht
- Department of Biology, Biochemistry, Faculty of Science, University of Fribourg, Fribourg, Switzerland
| | - William F Crowley
- National Center for Translational Research in Reproduction and Infertility, Harvard Reproductive Endocrine Sciences Center of the Department of Medicine, Massachusetts General Hospital, Boston, MA, USA
| | - Moosa Mohammadi
- Department of Biochemistry & Molecular Pharmacology, New York University School of Medicine, New York, NY, USA
| | - Manuel Tena-Sempere
- Department of Cell Biology, Physiology and Immunology, University of Cordoba, Cordoba, Spain.,Instituto Maimonides de Investigación Biomédica de Cordoba (IMIBIC/HURS), Cordoba, Spain.,CIBER Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos III, Cordoba, Spain
| | - Vincent Prevot
- Inserm, Laboratory of Development and Plasticity of the Neuroendocrine Brain, JPARC, Lille, France.,FHU 1000 Days for Health, School of Medicine, University of Lille, Lille, France
| | - Nelly Pitteloud
- Service of Endocrinology, Diabetology & Metabolism, Lausanne University Hospital, Lausanne, Switzerland
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82
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Calarco CA, Li Z, Taylor SR, Lee S, Zhou W, Friedman JM, Mineur YS, Gotti C, Picciotto MR. Molecular and cellular characterization of nicotinic acetylcholine receptor subtypes in the arcuate nucleus of the mouse hypothalamus. Eur J Neurosci 2018; 48:10.1111/ejn.13966. [PMID: 29791746 PMCID: PMC6251769 DOI: 10.1111/ejn.13966] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2018] [Revised: 04/26/2018] [Accepted: 05/09/2018] [Indexed: 12/22/2022]
Abstract
Nicotine, acting through nicotinic acetylcholine receptors (nAChRs), increases the firing rate of both orexigenic agouti-related peptide (AgRP) and anorexigenic pro-opiomelanocortin (POMC) neurons in the arcuate nucleus of the hypothalamus (ARC), yet nicotine and other nAChR agonists decrease food intake in mice. Viral-mediated knockdown of the β4 nAChR subunit in all neuronal cell types in the ARC prevents the nicotinic agonist cytisine from decreasing food intake, but it is not known whether the β4 subunit is selectively expressed in anorexigenic neurons or how other nAChR subtypes are distributed in this nucleus. Using translating ribosome affinity purification (TRAP) on ARC tissue from mice with ribosomes tagged in either AgRP or POMC cells, we examined nAChR subunit mRNA levels using real-time PCR. Both AgRP and POMC cells express a comparable panel of nAChR subunits with differences in α7 mRNA levels and a trend for difference in α4 levels, but no differences in β4 expression. Immunoprecipitation of assembled nAChRs revealed that the β4 subunit forms assembled channels with α3, β2 and α4, but not other subunits found in the ARC. Finally, using cell type-selective, virally delivered small hairpin RNAs targeting either the β4 or α7 subunit, we examined the contribution of each subunit in either AgRP or POMC cells to the behavioural response to nicotine, refining the understanding of nicotinic regulation of this feeding circuit. These experiments identify a more complex set of nAChRs expressed in ARC than in other hypothalamic regions. Thus, the ARC appears to be a particular target of nicotinic modulation.
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Affiliation(s)
- Cali A. Calarco
- Department of Psychiatry and Interdepartmental Neuroscience Program, Yale University School of Medicine, New Haven, CT 06508, USA
| | | | - Seth R. Taylor
- Department of Psychiatry and Interdepartmental Neuroscience Program, Yale University School of Medicine, New Haven, CT 06508, USA
| | - Somin Lee
- Department of Psychiatry and Interdepartmental Neuroscience Program, Yale University School of Medicine, New Haven, CT 06508, USA
| | - Wenliang Zhou
- Department of Psychiatry and Interdepartmental Neuroscience Program, Yale University School of Medicine, New Haven, CT 06508, USA
| | | | - Yann S. Mineur
- Department of Psychiatry and Interdepartmental Neuroscience Program, Yale University School of Medicine, New Haven, CT 06508, USA
| | | | - Marina R. Picciotto
- Department of Psychiatry and Interdepartmental Neuroscience Program, Yale University School of Medicine, New Haven, CT 06508, USA
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83
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Batailler M, Chesneau D, Derouet L, Butruille L, Segura S, Cognié J, Dupont J, Pillon D, Migaud M. Pineal-dependent increase of hypothalamic neurogenesis contributes to the timing of seasonal reproduction in sheep. Sci Rep 2018; 8:6188. [PMID: 29670193 PMCID: PMC5906660 DOI: 10.1038/s41598-018-24381-4] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2017] [Accepted: 03/26/2018] [Indexed: 11/20/2022] Open
Abstract
To survive in temperate latitudes, species rely on the photoperiod to synchronize their physiological functions, including reproduction, with the predictable changes in the environment. In sheep, exposure to decreasing day length reactivates the hypothalamo-pituitary-gonadal axis, while during increasing day length, animals enter a period of sexual rest. Neural stem cells have been detected in the sheep hypothalamus and hypothalamic neurogenesis was found to respond to the photoperiod. However, the physiological relevance of this seasonal adult neurogenesis is still unexplored. This longitudinal study, therefore aimed to thoroughly characterize photoperiod-stimulated neurogenesis and to investigate whether the hypothalamic adult born-cells were involved in the seasonal timing of reproduction. Results showed that time course of cell proliferation reached a peak in the middle of the period of sexual activity, corresponding to decreasing day length period. This enhancement was suppressed when animals were deprived of seasonal time cues by pinealectomy, suggesting a role of melatonin in the seasonal regulation of cell proliferation. Furthermore, when the mitotic blocker cytosine-b-D-arabinofuranoside was administered centrally, the timing of seasonal reproduction was affected. Overall, our findings link the cyclic increase in hypothalamic neurogenesis to seasonal reproduction and suggest that photoperiod-regulated hypothalamic neurogenesis plays a substantial role in seasonal reproductive physiology.
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Affiliation(s)
- Martine Batailler
- INRA, UMR 85 Physiologie de la Reproduction et des Comportements, F-37380, Nouzilly, France.,CNRS, UMR7247, F-37380, Nouzilly, France.,Université de Tours, F-37041, Tours, France.,Institut Français du Cheval et de l'Equitation (IFCE), F-37380, Nouzilly, France
| | - Didier Chesneau
- INRA, UMR 85 Physiologie de la Reproduction et des Comportements, F-37380, Nouzilly, France.,CNRS, UMR7247, F-37380, Nouzilly, France.,Université de Tours, F-37041, Tours, France.,Institut Français du Cheval et de l'Equitation (IFCE), F-37380, Nouzilly, France
| | - Laura Derouet
- INRA, UMR 85 Physiologie de la Reproduction et des Comportements, F-37380, Nouzilly, France.,CNRS, UMR7247, F-37380, Nouzilly, France.,Université de Tours, F-37041, Tours, France.,Institut Français du Cheval et de l'Equitation (IFCE), F-37380, Nouzilly, France
| | - Lucile Butruille
- INRA, UMR 85 Physiologie de la Reproduction et des Comportements, F-37380, Nouzilly, France.,CNRS, UMR7247, F-37380, Nouzilly, France.,Université de Tours, F-37041, Tours, France.,Institut Français du Cheval et de l'Equitation (IFCE), F-37380, Nouzilly, France
| | - Stéphanie Segura
- INRA, UMR 85 Physiologie de la Reproduction et des Comportements, F-37380, Nouzilly, France.,CNRS, UMR7247, F-37380, Nouzilly, France.,Université de Tours, F-37041, Tours, France.,Institut Français du Cheval et de l'Equitation (IFCE), F-37380, Nouzilly, France
| | - Juliette Cognié
- INRA, UMR 85 Physiologie de la Reproduction et des Comportements, F-37380, Nouzilly, France.,CNRS, UMR7247, F-37380, Nouzilly, France.,Université de Tours, F-37041, Tours, France.,Institut Français du Cheval et de l'Equitation (IFCE), F-37380, Nouzilly, France
| | - Joëlle Dupont
- INRA, UMR 85 Physiologie de la Reproduction et des Comportements, F-37380, Nouzilly, France.,CNRS, UMR7247, F-37380, Nouzilly, France.,Université de Tours, F-37041, Tours, France.,Institut Français du Cheval et de l'Equitation (IFCE), F-37380, Nouzilly, France
| | - Delphine Pillon
- INRA, UMR 85 Physiologie de la Reproduction et des Comportements, F-37380, Nouzilly, France.,CNRS, UMR7247, F-37380, Nouzilly, France.,Université de Tours, F-37041, Tours, France.,Institut Français du Cheval et de l'Equitation (IFCE), F-37380, Nouzilly, France
| | - Martine Migaud
- INRA, UMR 85 Physiologie de la Reproduction et des Comportements, F-37380, Nouzilly, France. .,CNRS, UMR7247, F-37380, Nouzilly, France. .,Université de Tours, F-37041, Tours, France. .,Institut Français du Cheval et de l'Equitation (IFCE), F-37380, Nouzilly, France.
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84
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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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85
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Pellegrino G, Trubert C, Terrien J, Pifferi F, Leroy D, Loyens A, Migaud M, Baroncini M, Maurage CA, Fontaine C, Prévot V, Sharif A. A comparative study of the neural stem cell niche in the adult hypothalamus of human, mouse, rat and gray mouse lemur (Microcebus murinus). J Comp Neurol 2018; 526:1419-1443. [PMID: 29230807 DOI: 10.1002/cne.24376] [Citation(s) in RCA: 55] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2017] [Revised: 11/08/2017] [Accepted: 11/27/2017] [Indexed: 12/20/2022]
Abstract
The adult brain contains niches of neural stem cells that continuously add new neurons to selected circuits throughout life. Two niches have been extensively studied in various mammalian species including humans, the subventricular zone of the lateral ventricles and the subgranular zone of the hippocampal dentate gyrus. Recently, studies conducted mainly in rodents have identified a third neurogenic niche in the adult hypothalamus. In order to evaluate whether a neural stem cell niche also exists in the adult hypothalamus in humans, we performed multiple immunofluorescence labeling to assess the expression of a panel of neural stem/progenitor cell (NPC) markers (Sox2, nestin, vimentin, GLAST, GFAP) in the human hypothalamus and compared them with the mouse, rat and a non-human primate species, the gray mouse lemur (Microcebus murinus). Our results show that the adult human hypothalamus contains four distinct populations of cells that express the five NPC markers: (a) a ribbon of small stellate cells that lines the third ventricular wall behind a hypocellular gap, similar to that found along the lateral ventricles, (b) ependymal cells, (c) tanycytes, which line the floor of the third ventricle in the tuberal region, and (d) a population of small stellate cells in the suprachiasmatic nucleus. In the mouse, rat and mouse lemur hypothalamus, co-expression of NPC markers is primarily restricted to tanycytes, and these species lack a ventricular ribbon. Our work thus identifies four cell populations with the antigenic profile of NPCs in the adult human hypothalamus, of which three appear specific to humans.
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Affiliation(s)
- Giuliana Pellegrino
- Inserm, Jean-Pierre Aubert Research Center, Development and Plasticity of the Neuroendocrine Brain, Lille Cedex, France.,University of Lille, School of Medicine, Lille Cedex, France
| | - Claire Trubert
- Inserm, Jean-Pierre Aubert Research Center, Development and Plasticity of the Neuroendocrine Brain, Lille Cedex, France.,University of Lille, School of Medicine, Lille Cedex, France
| | - Jérémy Terrien
- MECADEV UMR 7179, Centre National de la Recherche Scientifique, Muséum National d'Histoire Naturelle, Brunoy, France
| | - Fabien Pifferi
- MECADEV UMR 7179, Centre National de la Recherche Scientifique, Muséum National d'Histoire Naturelle, Brunoy, France
| | - Danièle Leroy
- Inserm, Jean-Pierre Aubert Research Center, Development and Plasticity of the Neuroendocrine Brain, Lille Cedex, France
| | - Anne Loyens
- Inserm, Jean-Pierre Aubert Research Center, Development and Plasticity of the Neuroendocrine Brain, Lille Cedex, France
| | - Martine Migaud
- INRA, UMR 85 Physiologie de la Reproduction et des Comportements, Nouzilly, France.,CNRS, UMR7247, Nouzilly, France; Université de Tours, Tours, France.,Institut Français du Cheval et de l'Equitation (IFCE), Nouzilly, France
| | - Marc Baroncini
- Inserm, Jean-Pierre Aubert Research Center, Development and Plasticity of the Neuroendocrine Brain, Lille Cedex, France.,University of Lille, School of Medicine, Lille Cedex, France.,Department of Neurosurgery, Lille University Hospital, Lille, France
| | - Claude-Alain Maurage
- Inserm, Jean-Pierre Aubert Research Center, Development and Plasticity of the Neuroendocrine Brain, Lille Cedex, France.,University of Lille, School of Medicine, Lille Cedex, France.,Department of Neuropathology, Lille University Hospital, Lille, France
| | - Christian Fontaine
- University of Lille, School of Medicine, Lille Cedex, France.,Laboratory of Anatomy, Lille University Hospital, Lille, France
| | - Vincent Prévot
- Inserm, Jean-Pierre Aubert Research Center, Development and Plasticity of the Neuroendocrine Brain, Lille Cedex, France.,University of Lille, School of Medicine, Lille Cedex, France
| | - Ariane Sharif
- Inserm, Jean-Pierre Aubert Research Center, Development and Plasticity of the Neuroendocrine Brain, Lille Cedex, France.,University of Lille, School of Medicine, Lille Cedex, France
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86
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Heeley N, Kirwan P, Darwish T, Arnaud M, Evans ML, Merkle FT, Reimann F, Gribble FM, Blouet C. Rapid sensing of l-leucine by human and murine hypothalamic neurons: Neurochemical and mechanistic insights. Mol Metab 2018; 10:14-27. [PMID: 29439854 PMCID: PMC5985239 DOI: 10.1016/j.molmet.2018.01.021] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/05/2018] [Revised: 01/24/2018] [Accepted: 01/29/2018] [Indexed: 11/27/2022] Open
Abstract
Objective Dietary proteins are sensed by hypothalamic neurons and strongly influence multiple aspects of metabolic health, including appetite, weight gain, and adiposity. However, little is known about the mechanisms by which hypothalamic neural circuits controlling behavior and metabolism sense protein availability. The aim of this study is to characterize how neurons from the mediobasal hypothalamus respond to a signal of protein availability: the amino acid l-leucine. Methods We used primary cultures of post-weaning murine mediobasal hypothalamic neurons, hypothalamic neurons derived from human induced pluripotent stem cells, and calcium imaging to characterize rapid neuronal responses to physiological changes in extracellular l-Leucine concentration. Results A neurochemically diverse subset of both mouse and human hypothalamic neurons responded rapidly to l-leucine. Consistent with l-leucine's anorexigenic role, we found that 25% of mouse MBH POMC neurons were activated by l-leucine. 10% of MBH NPY neurons were inhibited by l-leucine, and leucine rapidly reduced AGRP secretion, providing a mechanism for the rapid leucine-induced inhibition of foraging behavior in rodents. Surprisingly, none of the candidate mechanisms previously implicated in hypothalamic leucine sensing (KATP channels, mTORC1 signaling, amino-acid decarboxylation) were involved in the acute activity changes produced by l-leucine. Instead, our data indicate that leucine-induced neuronal activation involves a plasma membrane Ca2+ channel, whereas leucine-induced neuronal inhibition is mediated by inhibition of a store-operated Ca2+ current. Conclusions A subset of neurons in the mediobasal hypothalamus rapidly respond to physiological changes in extracellular leucine concentration. Leucine can produce both increases and decreases in neuronal Ca2+ concentrations in a neurochemically-diverse group of neurons, including some POMC and NPY/AGRP neurons. Our data reveal that leucine can signal through novel mechanisms to rapidly affect neuronal activity. A neurochemically diverse group of mouse and human hypothalamic neurons rapidly sense and respond to l-leucine. Leucine can produce neuronal activation or neuronal inhibition via distinct and novel Ca2+ signaling mechanisms. Leucine activates 25% ARH POMC neurons. Leucine inhibits 10% ARH NPY/AGRP neurons and reduces AGRP secretion from fasted mediobasal hypothalamic slices.
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Affiliation(s)
- Nicholas Heeley
- MRC Metabolic Diseases Unit, University of Cambridge Metabolic Research Laboratories, WT-MRC Institute of Metabolic Science, University of Cambridge, Cambridge CB2 OQQ, UK
| | - Peter Kirwan
- MRC Metabolic Diseases Unit, University of Cambridge Metabolic Research Laboratories, WT-MRC Institute of Metabolic Science, University of Cambridge, Cambridge CB2 OQQ, UK
| | - Tamana Darwish
- MRC Metabolic Diseases Unit, University of Cambridge Metabolic Research Laboratories, WT-MRC Institute of Metabolic Science, University of Cambridge, Cambridge CB2 OQQ, UK
| | - Marion Arnaud
- MRC Metabolic Diseases Unit, University of Cambridge Metabolic Research Laboratories, WT-MRC Institute of Metabolic Science, University of Cambridge, Cambridge CB2 OQQ, UK
| | - Mark L Evans
- MRC Metabolic Diseases Unit, University of Cambridge Metabolic Research Laboratories, WT-MRC Institute of Metabolic Science, University of Cambridge, Cambridge CB2 OQQ, UK
| | - Florian T Merkle
- MRC Metabolic Diseases Unit, University of Cambridge Metabolic Research Laboratories, WT-MRC Institute of Metabolic Science, University of Cambridge, Cambridge CB2 OQQ, UK
| | - Frank Reimann
- MRC Metabolic Diseases Unit, University of Cambridge Metabolic Research Laboratories, WT-MRC Institute of Metabolic Science, University of Cambridge, Cambridge CB2 OQQ, UK
| | - Fiona M Gribble
- MRC Metabolic Diseases Unit, University of Cambridge Metabolic Research Laboratories, WT-MRC Institute of Metabolic Science, University of Cambridge, Cambridge CB2 OQQ, UK
| | - Clemence Blouet
- MRC Metabolic Diseases Unit, University of Cambridge Metabolic Research Laboratories, WT-MRC Institute of Metabolic Science, University of Cambridge, Cambridge CB2 OQQ, UK.
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87
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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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88
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Robins SC, Kokoeva MV. NG2-Glia, a New Player in Energy Balance. Neuroendocrinology 2018; 107:305-312. [PMID: 29506015 DOI: 10.1159/000488111] [Citation(s) in RCA: 7] [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: 12/04/2017] [Accepted: 03/03/2018] [Indexed: 11/19/2022]
Abstract
There is increasing evidence that glia act not only as neuronal support cells, but that they can also influence physiological outcomes via effects on neural signalling. The role of NG2-glia in this regard is especially enigmatic, as they are known to interact with neural circuits but their precise functions other than as oligodendrocyte progenitor cells remain elusive. Here, we summarise recent evidence suggesting that NG2-glia play a role in the maintenance of energy homeostasis, most notably via the support of leptin-sensing neural circuits. We also discuss the potential clinical implication of these findings specifically in the context of cranial radiation therapy.
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89
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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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90
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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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91
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Abstract
Leptin is an adipocyte-derived hormone, which contributes to the homeostatic regulation of energy balance and metabolism through humoral and neural pathways. Leptin acts on the neurons in certain brain areas such as the hypothalamus, hippocampus, and brain stem to regulate food intake, thermogenesis, energy expenditure, and homeostasis of glucose/lipid metabolism. The pathologically increased circulating leptin is a biomarker of leptin resistance, which is common in obese individuals. Leptin resistance is defined by a reduced sensitivity or a failure in response of the brain to leptin, showing a decrease in the ability of leptin to suppress appetite or enhance energy expenditure, which causes an increased food intake and finally leads to overweight, obesity, cardiovascular diseases, and other metabolic disorders. Leptin resistance is a challenge for clinical treatment or drug discovery of obesity. Until recently, emerging evidence has been showing novel mechanisms of the leptin resistance. Here, we summarized the advances and controversy of leptin resistance and associated diseases, for better understanding the physiology and pathophysiology of leptin as well as the new strategies for treating obesity and metabolic disorders.
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92
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Birey F, Kokkosis AG, Aguirre A. Oligodendroglia-lineage cells in brain plasticity, homeostasis and psychiatric disorders. Curr Opin Neurobiol 2017; 47:93-103. [PMID: 29073529 DOI: 10.1016/j.conb.2017.09.016] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2017] [Revised: 09/20/2017] [Accepted: 09/25/2017] [Indexed: 12/11/2022]
Abstract
Adult oligodendrocyte progenitor cells are uniformly distributed in both gray and white matter, displaying robust proliferative and migratory potential during health and disease. Recently, developments in new experimental approaches have brought about several novel insights about NG2-glia and myelinating oligodendrocytes, indicating a diverse toolkit of functions in experience-dependent myelination and homeostasis in the adult CNS. In this review, we summarize some of the topical studies that highlight newly emerging findings implicating oligodendroglia-lineage cells in brain plasticity, homeostasis and pathophysiology of neuropsychiatric disorders.
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Affiliation(s)
- F Birey
- Stanford University, Department of Psychiatry and Behavioral Sciences, United States
| | - A G Kokkosis
- SUNY, Stony Brook, Department of Pharmacological Sciences, United States
| | - A Aguirre
- SUNY, Stony Brook, Department of Pharmacological Sciences, United States.
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93
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Xie Y, Dorsky RI. Development of the hypothalamus: conservation, modification and innovation. Development 2017; 144:1588-1599. [PMID: 28465334 DOI: 10.1242/dev.139055] [Citation(s) in RCA: 94] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The hypothalamus, which regulates fundamental aspects of physiological homeostasis and behavior, is a brain region that exhibits highly conserved anatomy across vertebrate species. Its development involves conserved basic mechanisms of induction and patterning, combined with a more plastic process of neuronal fate specification, to produce brain circuits that mediate physiology and behavior according to the needs of each species. Here, we review the factors involved in the induction, patterning and neuronal differentiation of the hypothalamus, highlighting recent evidence that illustrates how changes in Wnt/β-catenin signaling during development may lead to species-specific form and function of this important brain structure.
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Affiliation(s)
- Yuanyuan Xie
- Department of Neurobiology and Anatomy, University of Utah, Salt Lake City, UT 84112, USA
| | - Richard I Dorsky
- Department of Neurobiology and Anatomy, University of Utah, Salt Lake City, UT 84112, USA
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94
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Mohr MA, DonCarlos LL, Sisk CL. Inhibiting Production of New Brain Cells during Puberty or Adulthood Blunts the Hormonally Induced Surge of Luteinizing Hormone in Female Rats. eNeuro 2017; 4:ENEURO.0133-17.2017. [PMID: 29098175 PMCID: PMC5666323 DOI: 10.1523/eneuro.0133-17.2017] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2017] [Revised: 10/09/2017] [Accepted: 10/16/2017] [Indexed: 01/15/2023] Open
Abstract
New cells are added during both puberty and adulthood to hypothalamic regions that govern reproduction, homeostasis, and social behaviors, yet the functions of these late-born cells remain elusive. Here, we pharmacologically inhibited cell proliferation in ventricular zones during puberty or in adulthood and determined subsequent effects on the hormone-induced surge of luteinizing hormone (LH) in female rats. Initial neuroanatomical analyses focused on verifying incorporation, activation, and pharmacological inhibition of pubertally or adult born cells in the anteroventral periventricular nucleus (AVPV) of the hypothalamus because of the essential role of the AVPV in triggering the preovulatory LH surge in females. We first showed that approximately half of the pubertally born AVPV cells are activated by estradiol plus progesterone (P) treatment, as demonstrated by Fos expression, and that approximately 10% of pubertally born AVPV cells express estrogen receptor alpha (ERα). Next, we found that mitotic inhibition through intracerebroventricular (ICV) administration of cytosine β-D-arabinofuranoside (AraC), whether during puberty or in adulthood, decreased the number of new cells added to the AVPV and the suprachiasmatic nucleus (SCN), and also blunted and delayed the hormone-induced LH surge. These studies do not prove, but are highly suggestive, that ongoing postnatal addition of new cells in periventricular brain regions, including the AVPV and SCN, may be important to the integrity of female reproduction.
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Affiliation(s)
- Margaret A. Mohr
- Neuroscience Program, Michigan State University, East Lansing, MI 48824
| | - Lydia L. DonCarlos
- Department of Cell and Molecular Physiology, Stritch School of Medicine, Loyola University Chicago, Maywood, IL 60153
| | - Cheryl L. Sisk
- Neuroscience Program, Michigan State University, East Lansing, MI 48824
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95
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Balia M, Benamer N, Angulo MC. A specific GABAergic synapse onto oligodendrocyte precursors does not regulate cortical oligodendrogenesis. Glia 2017; 65:1821-1832. [PMID: 28795438 DOI: 10.1002/glia.23197] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2017] [Revised: 07/12/2017] [Accepted: 07/14/2017] [Indexed: 01/13/2023]
Abstract
In the brain, neurons establish bona fide synapses onto oligodendrocyte precursor cells (OPCs), but the function of these neuron-glia synapses remains unresolved. A leading hypothesis suggests that these synapses regulate OPC proliferation and differentiation. However, a causal link between synaptic activity and OPC cellular dynamics is still missing. In the developing somatosensory cortex, OPCs receive a major type of synapse from GABAergic interneurons that is mediated by postsynaptic γ2-containing GABAA receptors. Here we genetically silenced these receptors in OPCs during the critical period of cortical oligodendrogenesis. We found that the inactivation of γ2-mediated synapses does not impact OPC proliferation and differentiation or the propensity of OPCs to myelinate their presynaptic interneurons. However, this inactivation causes a progressive and specific depletion of the OPC pool that lacks γ2-mediated synaptic activity without affecting the oligodendrocyte production. Our results show that, during cortical development, the γ2-mediated interneuron-to-OPC synapses do not play a role in oligodendrogenesis and suggest that these synapses finely tune OPC self-maintenance capacity. They also open the interesting possibility that a particular synaptic signaling onto OPCs plays a specific role in OPC function according to the neurotransmitter released, the identity of presynaptic neurons or the postsynaptic receptors involved.
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Affiliation(s)
- Maddalena Balia
- Laboratory of Neurophysiology and New Microscopies, INSERM U1128, Paris, France.,Université Paris Descartes, Sorbonne Paris Cité, France
| | - Najate Benamer
- Laboratory of Neurophysiology and New Microscopies, INSERM U1128, Paris, France.,Université Paris Descartes, Sorbonne Paris Cité, France
| | - María Cecilia Angulo
- Laboratory of Neurophysiology and New Microscopies, INSERM U1128, Paris, France.,Université Paris Descartes, Sorbonne Paris Cité, France
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96
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Butruille L, Batailler M, Mazur D, Prévot V, Migaud M. Seasonal reorganization of hypothalamic neurogenic niche in adult sheep. Brain Struct Funct 2017; 223:91-109. [DOI: 10.1007/s00429-017-1478-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2017] [Accepted: 07/16/2017] [Indexed: 01/09/2023]
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97
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Valdearcos M, Douglass JD, Robblee MM, Dorfman MD, Stifler DR, Bennett ML, Gerritse I, Fasnacht R, Barres BA, Thaler JP, Koliwad SK. Microglial Inflammatory Signaling Orchestrates the Hypothalamic Immune Response to Dietary Excess and Mediates Obesity Susceptibility. Cell Metab 2017; 26:185-197.e3. [PMID: 28683286 PMCID: PMC5569901 DOI: 10.1016/j.cmet.2017.05.015] [Citation(s) in RCA: 277] [Impact Index Per Article: 39.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/10/2016] [Revised: 04/13/2017] [Accepted: 05/29/2017] [Indexed: 01/08/2023]
Abstract
Dietary excess triggers accumulation of pro-inflammatory microglia in the mediobasal hypothalamus (MBH), but the components of this microgliosis and its metabolic consequences remain uncertain. Here, we show that microglial inflammatory signaling determines the immunologic response of the MBH to dietary excess and regulates hypothalamic control of energy homeostasis in mice. Either pharmacologically depleting microglia or selectively restraining microglial NF-κB-dependent signaling sharply reduced microgliosis, an effect that includes prevention of MBH entry by bone-marrow-derived myeloid cells, and greatly limited diet-induced hyperphagia and weight gain. Conversely, forcing microglial activation through cell-specific deletion of the negative NF-κB regulator A20 induced spontaneous MBH microgliosis and cellular infiltration, reduced energy expenditure, and increased both food intake and weight gain even in absence of a dietary challenge. Thus, microglial inflammatory activation, stimulated by dietary excess, orchestrates a multicellular hypothalamic response that mediates obesity susceptibility, providing a mechanistic rationale for non-neuronal approaches to treat metabolic diseases.
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Affiliation(s)
- Martin Valdearcos
- The Diabetes Center, University of California San Francisco, San Francisco, CA 94143, USA
| | - John D Douglass
- University of Washington Diabetes Institute, University of Washington, Seattle, WA 98109, USA; Department of Medicine, University of Washington, Seattle, WA 98109, USA
| | - Megan M Robblee
- The Diabetes Center, University of California San Francisco, San Francisco, CA 94143, USA
| | - Mauricio D Dorfman
- University of Washington Diabetes Institute, University of Washington, Seattle, WA 98109, USA; Department of Medicine, University of Washington, Seattle, WA 98109, USA
| | - Daniel R Stifler
- The Diabetes Center, University of California San Francisco, San Francisco, CA 94143, USA
| | - Mariko L Bennett
- Department of Neurobiology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Irene Gerritse
- The Diabetes Center, University of California San Francisco, San Francisco, CA 94143, USA; Graduate School of Life Sciences, University of Utrecht, 3584 CL Utrecht, the Netherlands
| | - Rachael Fasnacht
- University of Washington Diabetes Institute, University of Washington, Seattle, WA 98109, USA; Department of Medicine, University of Washington, Seattle, WA 98109, USA
| | - Ben A Barres
- Department of Neurobiology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Joshua P Thaler
- University of Washington Diabetes Institute, University of Washington, Seattle, WA 98109, USA; Department of Medicine, University of Washington, Seattle, WA 98109, USA.
| | - Suneil K Koliwad
- The Diabetes Center, University of California San Francisco, San Francisco, CA 94143, USA; Department of Medicine, University of California San Francisco, San Francisco, CA 94143, USA.
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98
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Abstract
The hypothalamic control of metabolism appears to be a puzzle that cannot be explained by neuronal function alone. Zhang and colleagues (2017) add a few new pieces by demonstrating that astrocytes critically modulate neural circuits controlling energy homeostasis through nutritional-status-dependent morphological plasticity and IKKβ/NF-κB signaling, which modulate extracellular neurotransmitter bioavailability.
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Affiliation(s)
- Ariane Sharif
- INSERM, Laboratory of Development and Plasticity of the Neuroendocrine Brain, Jean-Pierre Aubert Research Center, UMR_S1172, School of Medicine, University of Lille, F-59000 Lille, France
| | - Vincent Prevot
- INSERM, Laboratory of Development and Plasticity of the Neuroendocrine Brain, Jean-Pierre Aubert Research Center, UMR_S1172, School of Medicine, University of Lille, F-59000 Lille, France.
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99
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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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100
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Rizzoti K, Lovell-Badge R. Pivotal role of median eminence tanycytes for hypothalamic function and neurogenesis. Mol Cell Endocrinol 2017; 445:7-13. [PMID: 27530416 DOI: 10.1016/j.mce.2016.08.020] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/30/2016] [Accepted: 08/11/2016] [Indexed: 01/15/2023]
Abstract
Along with the sub-ventricular zone of the forebrain lateral ventricles and the sub-granular zone of the dentate gyrus in the hippocampus, the hypothalamus has recently emerged as a third gliogenic and neurogenic niche in the central nervous system. The hypothalamus is the main regulator of body homeostasis because it centralizes peripheral information to regulate crucial physiological functions through the pituitary gland and the autonomic nervous system. Its ability to sense signals originating outside the brain relies on its exposure to blood-born molecules through the median eminence, which is localized outside the blood brain barrier. Within the hypothalamus, a population of specialized radial glial cells, the tanycytes, control exposure to blood-born signals by acting both as sensors and regulators of the hypothalamic input and output. In addition, lineage-tracing experiments have recently revealed that tanycytes represent a population of hypothalamic stem cells, defining them as a pivotal cell type within the hypothalamus. Hypothalamic neurogenesis has moreover been shown to have an important role in feeding control and energy metabolism, which challenges previous knowledge and offers new therapeutic options.
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Affiliation(s)
- Karine Rizzoti
- The Francis Crick Institute, Mill Hill Laboratory, The Ridgeway, Mill Hill, London NW7 1AA, UK.
| | - Robin Lovell-Badge
- The Francis Crick Institute, Mill Hill Laboratory, The Ridgeway, Mill Hill, London NW7 1AA, UK.
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