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Paez-Gonzalez P, Lopez-de-San-Sebastian J, Ceron-Funez R, Jimenez AJ, Rodríguez-Perez LM. Therapeutic strategies to recover ependymal barrier after inflammatory damage: relevance for recovering neurogenesis during development. Front Neurosci 2023; 17:1204197. [PMID: 37397456 PMCID: PMC10308384 DOI: 10.3389/fnins.2023.1204197] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2023] [Accepted: 05/22/2023] [Indexed: 07/04/2023] Open
Abstract
The epithelium covering the surfaces of the cerebral ventricular system is known as the ependyma, and is essential for maintaining the physical and functional integrity of the central nervous system. Additionally, the ependyma plays an essential role in neurogenesis, neuroinflammatory modulation and neurodegenerative diseases. Ependyma barrier is severely affected by perinatal hemorrhages and infections that cross the blood brain barrier. The recovery and regeneration of ependyma after damage are key to stabilizing neuroinflammatory and neurodegenerative processes that are critical during early postnatal ages. Unfortunately, there are no effective therapies to regenerate this tissue in human patients. Here, the roles of the ependymal barrier in the context of neurogenesis and homeostasis are reviewed, and future research lines for development of actual therapeutic strategies are discussed.
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Affiliation(s)
- Patricia Paez-Gonzalez
- Department of Cell Biology, Genetics and Physiology, University of Malaga, Málaga, Spain
- Instituto de Investigación Biomédica de Málaga y Plataforma en Nanomedicina-IBIMA Plataforma BIONAND, Málaga, Spain
| | | | - Raquel Ceron-Funez
- Department of Cell Biology, Genetics and Physiology, University of Malaga, Málaga, Spain
| | - Antonio J. Jimenez
- Instituto de Investigación Biomédica de Málaga y Plataforma en Nanomedicina-IBIMA Plataforma BIONAND, Málaga, Spain
| | - Luis Manuel Rodríguez-Perez
- Department of Cell Biology, Genetics and Physiology, University of Malaga, Málaga, Spain
- Instituto de Investigación Biomédica de Málaga y Plataforma en Nanomedicina-IBIMA Plataforma BIONAND, Málaga, Spain
- Department of Human Physiology, Human Histology, Pathological Anatomy and Sports, University of Malaga, Málaga, Spain
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2
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Nelles DG, Hazrati LN. Ependymal cells and neurodegenerative disease: outcomes of compromised ependymal barrier function. Brain Commun 2022; 4:fcac288. [PMID: 36415662 PMCID: PMC9677497 DOI: 10.1093/braincomms/fcac288] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2022] [Revised: 09/13/2022] [Accepted: 11/01/2022] [Indexed: 08/08/2023] Open
Abstract
Within the central nervous system, ependymal cells form critical components of the blood-cerebrospinal fluid barrier and the cerebrospinal fluid-brain barrier. These barriers provide biochemical, immunological and physical protection against the entry of molecules and foreign substances into the cerebrospinal fluid while also regulating cerebrospinal fluid dynamics, such as the composition, flow and removal of waste from the cerebrospinal fluid. Previous research has demonstrated that several neurodegenerative diseases, such as Alzheimer's disease and multiple sclerosis, display irregularities in ependymal cell function, morphology, gene expression and metabolism. Despite playing key roles in maintaining overall brain health, ependymal barriers are largely overlooked and understudied in the context of disease, thus limiting the development of novel diagnostic and treatment options. Therefore, this review explores the anatomical properties, functions and structures that define ependymal cells in the healthy brain, as well as the ways in which ependymal cell dysregulation manifests across several neurodegenerative diseases. Specifically, we will address potential mechanisms, causes and consequences of ependymal cell dysfunction and describe how compromising the integrity of ependymal barriers may initiate, contribute to, or drive widespread neurodegeneration in the brain.
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Affiliation(s)
- Diana G Nelles
- Department of Laboratory Medicine and Pathobiology, University of Toronto, 1 King’s College Circle, Toronto, ON M5S 1A8, Canada
- Department of Paediatric Laboratory Medicine, The Hospital for Sick Children, 555 University Ave, Canada
| | - Lili-Naz Hazrati
- Correspondence to: Dr. Lili-Naz Hazrati 555 University Ave, Toronto ON M5G 1X8, Canada E-mail:
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3
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Tu TW, Kovacs ZI, Sundby M, Witko JA, Papadakis GZ, Reid WC, Hammoud DA, Frank JA. Diffusion Tensor Imaging and Chemical Exchange Saturation Transfer MRI Evaluation on the Long-Term Effects of Pulsed Focused Ultrasound and Microbubbles Blood Brain Barrier Opening in the Rat. Front Neurosci 2020; 14:908. [PMID: 32982680 PMCID: PMC7478124 DOI: 10.3389/fnins.2020.00908] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2020] [Accepted: 08/05/2020] [Indexed: 11/16/2022] Open
Abstract
Blood-brain barrier opening (BBBO) with pulsed Focused Ultrasound (pFUS) and microbubbles (MB) has received increasing interest as a method for neurotherapeutics of the central nervous system. In general, conventional MRI [i.e., T2w, T2∗w, gadolinium (Gd) enhanced T1w] is used to monitor the effects of pFUS+MB on BBBO and/or assess whether sonication results in parenchymal damage. This study employed multimodal MRI techniques and 18F-Fludeoxyglucose (FDG) PET to evaluate the effects of single and multiple weekly pFUS+MB sessions on morphology and glucose utilization levels in the rat cortex and hippocampus. pFUS was performed with 0.548 MHz transducer with a slow infusion over 1 min of OptisonTM (5–8 × 107 MB) in nine focal points in cortex and four in hippocampus. During pFUS+MB treatment, Gd-T1w was performed at 3 T to confirm BBBO, along with subsequent T2w, T2∗w, DTI and glucose CEST (glucoCEST)-weighted imaging by high field 9.4 T and compared with FDG-PET and immunohistochemistry. Animals receiving a single pFUS+MB exhibited minimal hypointense voxels on T2∗w. Brains receiving multiple pFUS+MB treatments demonstrated persistent T2w and T2∗ abnormalities associated with changes in DTI and glucoCEST when compared to contralateral parenchyma. Decreased glucoCEST contrast was substantiated by FDG-PET in cortex following multiple sonications. Immunohistochemistry showed significantly dilated vessels and decreased neuronal glucose transporter (GLUT3) expression in sonicated cortex and hippocampus without changes in neuronal counts. These results suggest the importance to standardize MRI protocols in concert with advanced imaging techniques when evaluating long term effects of pFUS+MB BBBO in clinical trials for neurological diseases.
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Affiliation(s)
- Tsang-Wei Tu
- Molecular Imaging Laboratory, Department of Radiology, Howard University College of Medicine, Washington, DC, United States.,Frank Laboratory, Radiology and Imaging Sciences, Clinical Center, National Institutes of Health (NIH), Bethesda, MD, United States.,Center for Neuroscience and Regenerative Medicine, Henry Jackson Foundation, Bethesda, MD, United States
| | - Zsofia I Kovacs
- Frank Laboratory, Radiology and Imaging Sciences, Clinical Center, National Institutes of Health (NIH), Bethesda, MD, United States.,Institute for Biomedical Engineering, Swiss Federal Institute of Technology, Zurich, Switzerland
| | - Maggie Sundby
- Frank Laboratory, Radiology and Imaging Sciences, Clinical Center, National Institutes of Health (NIH), Bethesda, MD, United States
| | - Jaclyn A Witko
- Frank Laboratory, Radiology and Imaging Sciences, Clinical Center, National Institutes of Health (NIH), Bethesda, MD, United States.,Center for Neuroscience and Regenerative Medicine, Henry Jackson Foundation, Bethesda, MD, United States
| | - Georgios Z Papadakis
- Center for Infectious Disease Imaging, Clinical Center, National Institutes of Health (NIH), Bethesda, MD, United States
| | - William C Reid
- Center for Infectious Disease Imaging, Clinical Center, National Institutes of Health (NIH), Bethesda, MD, United States
| | - Dima A Hammoud
- Center for Infectious Disease Imaging, Clinical Center, National Institutes of Health (NIH), Bethesda, MD, United States
| | - Joseph A Frank
- Frank Laboratory, Radiology and Imaging Sciences, Clinical Center, National Institutes of Health (NIH), Bethesda, MD, United States.,National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health (NIH), Bethesda, MD, United States
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4
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Li N, Yan QT, Jing Q, Pan RY, Wang HJ, Jiang B, Li XJ, Wang Y, Dong JH, Wang XJ, Zhang MJ, Meng QG, Li XZ, Liu ZJ, Gao ZQ, Qu MH. Duodenal-Jejunal Bypass Ameliorates Type 2 Diabetes Mellitus by Activating Insulin Signaling and Improving Glucose Utilization in the Brain. Obes Surg 2019; 30:279-289. [DOI: 10.1007/s11695-019-04153-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
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5
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Al-Ahmad AJ. Comparative study of expression and activity of glucose transporters between stem cell-derived brain microvascular endothelial cells and hCMEC/D3 cells. Am J Physiol Cell Physiol 2017; 313:C421-C429. [PMID: 28993322 DOI: 10.1152/ajpcell.00116.2017] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2017] [Revised: 07/28/2017] [Accepted: 07/28/2017] [Indexed: 12/22/2022]
Abstract
Glucose constitutes a major source of energy of mammalian brains. Glucose uptake at the blood-brain barrier (BBB) occurs through a facilitated glucose transport, through glucose transporter 1 (GLUT1), although other isoforms have been described at the BBB. Mutations in GLUT1 are associated with the GLUT1 deficiency syndrome, yet none of the current in vitro models of the human BBB maybe suited for modeling such a disorder. In this study, we investigated the expression of glucose transporters and glucose diffusion across brain microvascular endothelial cells (BMECs) derived from healthy patient-derived induced pluripotent stem cells (iPSCs). We investigated the expression of different glucose transporters at the BBB using immunocytochemistry and flow cytometry and measured glucose uptake and diffusion across BMEC monolayers obtained from two iPSC lines and from hCMEC/D3 cells. BMEC monolayers showed expression of several glucose transporters, in particular GLUT1, GLUT3, and GLUT4. Diffusion of glucose across the monolayers was mediated via a saturable transcellular mechanism and partially inhibited by pharmacological inhibitors. Taken together, our study suggests the presence of several glucose transporters isoforms at the human BBB and demonstrates the feasibility of modeling glucose across the BBB using patient-derived stem cells.
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Affiliation(s)
- Abraham J Al-Ahmad
- Texas Tech University Health Sciences Center, School of Pharmacy, Department of Pharmaceutical Sciences, Amarillo, Texas
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6
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Elizondo-Vega R, Cortes-Campos C, Barahona MJ, Oyarce KA, Carril CA, García-Robles MA. The role of tanycytes in hypothalamic glucosensing. J Cell Mol Med 2015; 19:1471-82. [PMID: 26081217 PMCID: PMC4511346 DOI: 10.1111/jcmm.12590] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2015] [Accepted: 03/03/2015] [Indexed: 12/23/2022] Open
Abstract
Tanycytes are elongated hypothalamic glial cells that cover the basal walls of the third ventricle; their apical regions contact the cerebrospinal fluid (CSF), and their processes reach hypothalamic neuronal nuclei that control the energy status of an organism. These nuclei maintain the balance between energy expenditure and intake, integrating several peripheral signals and triggering cellular responses that modify the feeding behaviour and peripheral glucose homeostasis. One of the most important and well-studied signals that control this process is glucose; however, the mechanism by which this molecule is sensed remains unknown. We along with others have proposed that tanycytes play a key role in this process, transducing changes in CSF glucose concentration to the neurons that control energy status. Recent studies have demonstrated the expression and function of monocarboxylate transporters and canonical pancreatic β cell glucose sensing molecules, including glucose transporter 2 and glucokinase, in tanycytes. These and other data, which will be discussed in this review, suggest that hypothalamic glucosensing is mediated through a metabolic interaction between tanycytes and neurons through lactate. This article will summarize the recent evidence that supports the importance of tanycytes in hypothalamic glucosensing, and discuss the possible mechanisms involved in this process. Finally, it is important to highlight that a detailed analysis of this mechanism could represent an opportunity to understand the evolution of associated pathologies, including diabetes and obesity, and identify new candidates for therapeutic intervention.
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Affiliation(s)
- Roberto Elizondo-Vega
- Laboratorio de Biología Celular, Departamento de Biología Celular, Facultad de Ciencias Biológicas, Universidad de Concepción, Concepción, Chile
| | | | - Maria J Barahona
- Laboratorio de Biología Celular, Departamento de Biología Celular, Facultad de Ciencias Biológicas, Universidad de Concepción, Concepción, Chile
| | - Karina A Oyarce
- Laboratorio de Biología Celular, Departamento de Biología Celular, Facultad de Ciencias Biológicas, Universidad de Concepción, Concepción, Chile
| | - Claudio A Carril
- Laboratorio de Biología Celular, Departamento de Biología Celular, Facultad de Ciencias Biológicas, Universidad de Concepción, Concepción, Chile
| | - Maria A García-Robles
- Laboratorio de Biología Celular, Departamento de Biología Celular, Facultad de Ciencias Biológicas, Universidad de Concepción, Concepción, Chile
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7
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Fuente-Martín E, García-Cáceres C, Granado M, de Ceballos ML, Sánchez-Garrido MÁ, Sarman B, Liu ZW, Dietrich MO, Tena-Sempere M, Argente-Arizón P, Díaz F, Argente J, Horvath TL, Chowen JA. Leptin regulates glutamate and glucose transporters in hypothalamic astrocytes. J Clin Invest 2012; 122:3900-13. [PMID: 23064363 DOI: 10.1172/jci64102] [Citation(s) in RCA: 155] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2012] [Accepted: 08/27/2012] [Indexed: 01/08/2023] Open
Abstract
Glial cells perform critical functions that alter the metabolism and activity of neurons, and there is increasing interest in their role in appetite and energy balance. Leptin, a key regulator of appetite and metabolism, has previously been reported to influence glial structural proteins and morphology. Here, we demonstrate that metabolic status and leptin also modify astrocyte-specific glutamate and glucose transporters, indicating that metabolic signals influence synaptic efficacy and glucose uptake and, ultimately, neuronal function. We found that basal and glucose-stimulated electrical activity of hypothalamic proopiomelanocortin (POMC) neurons in mice were altered in the offspring of mothers fed a high-fat diet. In adulthood, increased body weight and fasting also altered the expression of glucose and glutamate transporters. These results demonstrate that whole-organism metabolism alters hypothalamic glial cell activity and suggest that these cells play an important role in the pathology of obesity.
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Affiliation(s)
- Esther Fuente-Martín
- Hospital Infantil Universitario Niño Jesús, Department of Endocrinology, Instituto de Investigación La Princesa, Madrid, Spain
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8
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Del Bigio MR. Ependymal cells: biology and pathology. Acta Neuropathol 2010; 119:55-73. [PMID: 20024659 DOI: 10.1007/s00401-009-0624-y] [Citation(s) in RCA: 234] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2009] [Revised: 12/03/2009] [Accepted: 12/04/2009] [Indexed: 11/28/2022]
Abstract
The literature was reviewed to summarize the current understanding of the role of ciliated ependymal cells in the mammalian brain. Previous reviews were summarized. Publications from the past 10 years highlight interactions between ependymal cells and the subventricular zone and the possible role of restricted ependymal populations in neurogenesis. Ependymal cells provide trophic support and possibly metabolic support for progenitor cells. Channel proteins such as aquaporins may be important for determining water fluxes at the ventricle wall. The junctional and anchoring proteins are now fairly well understood, as are proteins related to cilia function. Defects in ependymal adhesion and cilia function can cause hydrocephalus through several different mechanisms, one possibility being loss of patency of the cerebral aqueduct. Ependymal cells are susceptible to infection by a wide range of common viruses; while they may act as a line of first defense, they eventually succumb to repeated attacks in long-lived organisms. Ciliated ependymal cells are almost certainly important during brain development. However, the widespread absence of ependymal cells from the adult human lateral ventricles suggests that they may have only regionally restricted value in the mature brain of large size.
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Affiliation(s)
- Marc R Del Bigio
- Department of Pathology, University of Manitoba, Winnipeg, MB, Canada.
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Arluison M, Quignon M, Nguyen P, Thorens B, Leloup C, Penicaud L. Distribution and anatomical localization of the glucose transporter 2 (GLUT2) in the adult rat brain--an immunohistochemical study. J Chem Neuroanat 2005; 28:117-36. [PMID: 15482899 DOI: 10.1016/j.jchemneu.2004.05.009] [Citation(s) in RCA: 112] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2003] [Revised: 01/05/2004] [Accepted: 05/23/2004] [Indexed: 11/17/2022]
Abstract
The aim of this work was to study the distribution and cellular localization of GLUT2 in the rat brain by light and electron microscopic immunohistochemistry, whereas our ultrastructural observations will be reported in a second paper. Confirming previous results, we show that GLUT2-immunoreactive profiles are present throughout the brain, especially in the limbic areas and related nuclei, whereas they appear most concentrated in the ventral and medial regions close to the midline. Using cresyl violet counterstaining and double immunohistochemical staining for glial or neuronal markers (GFAp, CAII and NeuN), we show that two limited populations of oligodendrocytes and astrocytes cell bodies and processes are immunoreactive for GLUT2, whereas a cross-reaction with GLUT1 cannot be ruled out. In addition, we report that the nerve cell bodies clearly immunostained for GLUT2 were scarce (although numerous in the dentate gyrus granular layer in particular), whereas the periphery of numerous nerve cells appeared labeled for this transporter. The latter were clustered in the dorsal endopiriform nucleus and neighboring temporal and perirhinal cortex, in the dorsal amygdaloid region, and in the paraventricular and reuniens thalamic nuclei, whereas they were only a few in the hypothalamus. Moreover, a group of GLUT2-immunoreactive nerve cell bodies was localized in the dorsal medulla oblongata while some large multipolar nerve cell bodies peripherally labeled for GLUT2 were scattered in the caudal ventral reticular formation. This anatomical localization of GLUT2 appears characteristic and different from that reported for the neuronal transporter GLUT3 and GLUT4. Indeed, the possibility that GLUT2 may be localized in the sub-plasmalemnal region of neurones and/or in afferent nerve fibres remains to be confirmed by ultrastructural observations. Because of the neuronal localization of GLUT2, and of its distribution relatively similar to glucokinase, it may be hypothesized that this transporter is, at least partially, involved in cerebral glucose sensing.
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Affiliation(s)
- Michel Arluison
- Laboratoire de Cytologie, Université Pierre et Marie Curie (Paris 6), CNRS UMR 7101 (Neurobiologie des Signaux Intercellulaires), 7 quai Saint Bernard, 75252 Paris Cedex 05, France.
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10
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Arluison M, Quignon M, Thorens B, Leloup C, Penicaud L. Immunocytochemical localization of the glucose transporter 2 (GLUT2) in the adult rat brain. II. Electron microscopic study. J Chem Neuroanat 2005; 28:137-46. [PMID: 15482900 DOI: 10.1016/j.jchemneu.2004.06.002] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2003] [Revised: 05/12/2004] [Accepted: 06/02/2004] [Indexed: 11/28/2022]
Abstract
Following a former immunohistochemical study in the rat brain [Arluison, M., Quignon, M., Nguyen, P., Thorens, B., Leloup, C., Penicaud, L. Distribution and anatomical localization of the glucose transporter 2 (GLUT2) in the adult rat brain. I. Immunohistochemical study. J. Chem. Neuroanat., in press], we have analyzed the ultrastructural localization of GLUT2 in representative and/or critical areas of the forebrain and hindbrain. In agreement with previous results, we observe few oligodendrocyte and astrocyte cell bodies discretely labeled for GLUT2 in large myelinated fibre bundles and most brain areas examined, whereas the reactive glial processes are more numerous and often localized in the vicinity of nerve terminals and/or dendrites or dendritic spines forming synaptic contacts. Only some of them appear closely bound to unlabeled nerve cell bodies and dendrites. Furthermore, the nerve cell bodies prominently immunostained for GLUT2 are scarce in the brain nuclei examined, whereas the labeled dendrites and dendritic spines are relatively numerous and frequently engaged in synaptic junctions. In conformity with the observation of GLUT2-immunoreactive rings at the periphery of numerous nerve cell bodies in various brain areas (see previous paper), we report here that some neuronal perikarya of the dorsal endopiriform nucleus/perirhinal cortex exhibit some patches of immunostaining just below the plasma membrane. However, the presence of many GLUT2-immunoreactive nerve terminals and/or astrocyte processes, some of them being occasionally attached to nerve cell bodies and dendrites, could also explain the pericellular labeling observed. The results here reported support the idea that GLUT2 may be expressed by some cerebral neurones possibly involved in glucose sensing, as previously discussed. However, it is also possible that this transporter participate in the regulation of neurotransmitter release and, perhaps, in the release of glucose by glial cells.
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Affiliation(s)
- Michel Arluison
- Laboratoire de Cytologie, CNRS UMR 7101, Neurobiologie des Signaux Intercellulaires, Université Pierre et Marie Curie (Paris 6), 7 quai Saint Bernard, 75252 Paris Cedex 05, France.
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11
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Hisano S, Nogami H. Transporters in the neurohypophysial neuroendocrine system, with special reference to vesicular glutamate transporters (BNPI and DNPI): a review. Microsc Res Tech 2002; 56:122-31. [PMID: 11810715 DOI: 10.1002/jemt.10014] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Recent advances in gene technology have helped to identify novel proteins and allowed study of their distribution and functions in the mammalian brain. One class of these proteins is that of transporters, which exist in plasma and organellar membranes of neurons and other cells to move substances selectively across membranes. These transporters can be categorized further into subclasses by their structural property, substrate selectivity, and site of action. Some of them have been identified in the hypothalamus, which is the only brain site where a neural signal is converted to a humoral one, namely, a hormone for a target organ. This unique neural mechanism has long attracted attention as the neuroendocrine system, part of which has been extensively studied as the hypothalamic-neurohypophysial system involved in secretion of vasopressin and oxytocin. However, transporters in this system have been less well studied. A morphological examination of novel transporters would give us cues to a better understanding of the neuronal organization and function of the system. In this review, we first summarize recent findings on expression of transporter gene and immunoreactivity in the hypothalamus. In the second part, we explain our observations on two vesicular glutamate (inorganic phosphate) transporters (BNPI and DNPI) in the supraoptic and paraventricular nuclei and neurohypophysis. Further study of these and other transporters will provide a basis on which to reevaluate the organization and function of the hypothalamic-neurohypophysial system.
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Affiliation(s)
- Setsuji Hisano
- Laboratory of Neuroendocrinology, Institute of Basic Medical Sciences, University of Tsukuba, Tsukuba 305-8575, Ibaraki, Japan.
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Li AJ, Oomura Y, Sasaki K, Suzuki K, Tooyama I, Hanai K, Kimura H, Hori T. A single pre-training glucose injection induces memory facilitation in rodents performing various tasks: contribution of acidic fibroblast growth factor. Neuroscience 1998; 85:785-94. [PMID: 9639272 DOI: 10.1016/s0306-4522(97)00630-1] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Effects of a pre-training intraperitoneal glucose injection on learning and memory were tested using two tasks: passive avoidance and Morris water maze. In the former task, mice that had received glucose 2 h prior (but not 1, 3, or 5 h prior) to a trial that combined acquisition with passive avoidance of foot shock showed a significantly increased retention latency when tested 24 h later. Thus, this effect was time-dependent, and it was also found to be dose-dependent by further experiment. In contrast, 2-deoxy-D-glucose and fructose had no such effect. In the Morris water maze task, glucose injection 2 or 3 h before a block of trials enhanced the spatial memory performance of mice. These glucose-induced memory-facilitation effects were abolished by an intracerebroventricular injection of anti-acidic fibroblast growth factor antibody 30 min before the glucose injection, suggesting a critical role for endogenous acidic fibroblast growth factor in this facilitatory effect. Furthermore, continuous intracerebroventricular infusion of acidic fibroblast growth factor in rats significantly increased retention latency (when tested repeatedly on successive days using a passive avoidance task). Our earlier studies demonstrated that brain acidic fibroblast growth factor is produced in the ependymal cells of the cerebroventricular system, and is released into the cerebrospinal fluid following either a meal or a (intraperitoneal or intracerebroventricular) glucose injection. This released acidic fibroblast growth factor also diffuses into the brain parenchyma, and is taken up by neurons in the hippocampus, hypothalamus, and elsewhere in the brain some 2 h after the meal or glucose injection. These and the present findings indicate (i) that pre-training glucose injection improves memory performance, and (ii) that acidic fibroblast growth factor, especially by its action within the hippocampus, is involved in this enhancement process.
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Affiliation(s)
- A J Li
- Department of Physiology, Faculty of Medicine, Kyushu University, Fukuoka, Japan
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13
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Yu S, Ding WG. The 45 kDa form of glucose transporter 1 (GLUT1) is localized in oligodendrocyte and astrocyte but not in microglia in the rat brain. Brain Res 1998; 797:65-72. [PMID: 9630522 DOI: 10.1016/s0006-8993(98)00372-2] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
We and others have previously reported that glucose transporter 1 (GLUT1)-like 45 kDa protein is localized to parenchymal cells in the brain. However, the precise cellular localization has remained unclear. In the present study, we examined the cellular localization of GLUT1 in the rat brain by double immunostaining methods and immunoelectron microscopic analysis using a rabbit antiserum specific to GLUT1. Western blot analysis of the rat brain revealed that the antiserum detected a strong band with a molecular weight of 45 kDa and a weak band of about 55 kDa, which corresponded respectively to the known molecular weights of the GLUT1 proteins in the brain parenchymal cells and the brain microvessels. Immunohistochemical staining revealed a large number of GLUT1-immunoreactive glial cells and microvessels in almost every region of the brain. Double immunofluorescence analysis demonstrated that the GLUT1-like 45 kDa protein occurred in many galactocerebroside-positive oligodendrocytes and in some glial fibrillary acidic protein (GFAP)-positive astrocytes. No GLUT1-immunoreactivity was observed in OX42-positive microglia. Immunoelectron microscopic examination confirmed that the GLUT1-immunoreactivity was mainly localized in the cytoplasm of the oligodendrocytes and astrocytes. The results indicate that the 45 kDa form of GLUT1 protein exists in the glial cells including astrocytes and oligodendrocytes.
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Affiliation(s)
- S Yu
- Institute of Molecular Neurobiology, Shiga University of Medical Science, Otsu 520-2192, Japan
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