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Weber CM, Moiz B, Clyne AM. Brain microvascular endothelial cell metabolism and its ties to barrier function. VITAMINS AND HORMONES 2024; 126:25-75. [PMID: 39029976 DOI: 10.1016/bs.vh.2024.05.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/21/2024]
Abstract
Brain microvascular endothelial cells, which lie at the interface between blood and brain, are critical to brain energetics. These cells must precisely balance metabolizing nutrients for their own demands with transporting nutrients into the brain to sustain parenchymal cells. It is essential to understand this integrated metabolism and transport so that we can develop better diagnostics and therapeutics for neurodegenerative diseases such as Alzheimer's disease, multiple sclerosis, and traumatic brain injury. In this chapter, we first describe brain microvascular endothelial cell metabolism and how these cells regulate both blood flow and nutrient transport. We then explain the impact of brain microvascular endothelial cell metabolism on the integrity of the blood-brain barrier, as well as how metabolites produced by the endothelial cells impact other brain cells. We detail some ways that cell metabolism is typically measured experimentally and modeled computationally. Finally, we describe changes in brain microvascular endothelial cell metabolism in aging and neurodegenerative diseases. At the end of the chapter, we highlight areas for future research in brain microvascular endothelial cell metabolism. The goal of this chapter is to underscore the importance of nutrient metabolism and transport at the brain endothelium for cerebral health and neurovascular disease treatment.
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Affiliation(s)
- Callie M Weber
- Fischell Department of Bioengineering, University of Maryland, College Park, MD, United States
| | - Bilal Moiz
- Fischell Department of Bioengineering, University of Maryland, College Park, MD, United States
| | - Alisa Morss Clyne
- Fischell Department of Bioengineering, University of Maryland, College Park, MD, United States.
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Abstract
The brain is a complex organ, fundamentally changing across the day to perform basic functions like sleep, thought, and regulating whole-body physiology. This requires a complex symphony of nutrients, hormones, ions, neurotransmitters and more to be properly distributed across the brain to maintain homeostasis throughout 24 hours. These solutes are distributed both by the blood and by cerebrospinal fluid. Cerebrospinal fluid contents are distinct from the general circulation because of regulation at brain barriers including the choroid plexus, glymphatic system, and blood-brain barrier. In this review, we discuss the overlapping circadian (≈24-hour) rhythms in brain fluid biology and at the brain barriers. Our goal is for the reader to gain both a fundamental understanding of brain barriers alongside an understanding of the interactions between these fluids and the circadian timing system. Ultimately, this review will provide new insight into how alterations in these finely tuned clocks may lead to pathology.
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Affiliation(s)
- Velia S Vizcarra
- Center for Translational Neuromedicine, University of Rochester Medical Center, Rochester, NY, 14642, USA
| | - Ryann M Fame
- Department of Neurosurgery, Stanford University School of Medicine, Stanford, CA, 94305, USA
| | - Lauren M Hablitz
- Center for Translational Neuromedicine, University of Rochester Medical Center, Rochester, NY, 14642, USA
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Wu WZ, Bai YP. Endothelial GLUTs and vascular biology. Biomed Pharmacother 2023; 158:114151. [PMID: 36565587 DOI: 10.1016/j.biopha.2022.114151] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Revised: 12/15/2022] [Accepted: 12/21/2022] [Indexed: 12/24/2022] Open
Abstract
Endothelial metabolism is a promising target for vascular functional regulation and disease therapy. Glucose is the primary fuel for endothelial metabolism, supporting ATP generation and endothelial cell survival. Multiple studies have discussed the role of endothelial glucose catabolism, such as glycolysis and oxidative phosphorylation, in vascular functional remodeling. However, the role of the first gatekeepers of endothelial glucose utilization, glucose transporters, in the vasculature has long been neglected. Here, this review summarizes glucose transporter studies in vascular research. We mainly focus on GLUT1 and GLUT3 because they are the most critical glucose transporters responsible for most endothelial glucose uptake. Some interesting topics are also discussed, intending to provide directions for endothelial glucose transporter research in the future.
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Affiliation(s)
- Wan-Zhou Wu
- Department of Geriatric Medicine, Xiangya Hospital, Central South University, Changsha, China; National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China; Center for Vascular Disease and Translational Medicine, Department of Cardiology, The Third Xiangya Hospital, Central South University, Changsha, China
| | - Yong-Ping Bai
- Department of Geriatric Medicine, Xiangya Hospital, Central South University, Changsha, China; National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China.
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Rhea EM, Banks WA. A historical perspective on the interactions of insulin at the blood-brain barrier. J Neuroendocrinol 2021; 33:e12929. [PMID: 33433042 PMCID: PMC8052275 DOI: 10.1111/jne.12929] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/26/2020] [Revised: 11/18/2020] [Accepted: 12/02/2020] [Indexed: 11/30/2022]
Abstract
Subsequent to the discovery of insulin in 1921, the role of insulin in the brain has been investigated throughly. The ability of insulin to act within the brain to regulate peripheral glucose levels helped evolve the research surrounding the ability of insulin to be transported into the brain. Investigations aiming to determine the transport of insulin into the brain from the circulation soon followed. Once it was established that insulin could enter the brain, the ability of insulin to bind brain microvessels and regulators of this process were determined. As technology advanced, quantitative measurements to specify the transport rate of insulin across the blood-brain barrier (BBB) and the impact of physiological conditions and diseases were the logical next steps. Lastly, with the advent of genetic mouse models and high-specificity antagonists, the specific role of the insulin receptor in mediating insulin transport could begin to be explored. In this review, we summarise the main findings throughout the decades regarding the interactions of insulin at the BBB.
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Affiliation(s)
- Elizabeth M. Rhea
- Division of Gerontology and Geriatric Medicine, Department of Medicine, University of Washington School of Medicine, Seattle, Washington, USA 98159
- Geriatrics Research Education and Clinical Center, Veterans Affairs Puget Sound Health Care System, 1660 S Columbian Way, Seattle, Washington, USA 98108
- Corresponding author: Elizabeth M. Rhea;
| | - William A. Banks
- Division of Gerontology and Geriatric Medicine, Department of Medicine, University of Washington School of Medicine, Seattle, Washington, USA 98159
- Geriatrics Research Education and Clinical Center, Veterans Affairs Puget Sound Health Care System, 1660 S Columbian Way, Seattle, Washington, USA 98108
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Verhoog QP, Holtman L, Aronica E, van Vliet EA. Astrocytes as Guardians of Neuronal Excitability: Mechanisms Underlying Epileptogenesis. Front Neurol 2020; 11:591690. [PMID: 33324329 PMCID: PMC7726323 DOI: 10.3389/fneur.2020.591690] [Citation(s) in RCA: 73] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Accepted: 10/26/2020] [Indexed: 12/11/2022] Open
Abstract
Astrocytes are key homeostatic regulators in the central nervous system and play important roles in physiology. After brain damage caused by e.g., status epilepticus, traumatic brain injury, or stroke, astrocytes may adopt a reactive phenotype. This process of reactive astrogliosis is important to restore brain homeostasis. However, persistent reactive astrogliosis can be detrimental for the brain and contributes to the development of epilepsy. In this review, we will focus on physiological functions of astrocytes in the normal brain as well as pathophysiological functions in the epileptogenic brain, with a focus on acquired epilepsy. We will discuss the role of astrocyte-related processes in epileptogenesis, including reactive astrogliosis, disturbances in energy supply and metabolism, gliotransmission, and extracellular ion concentrations, as well as blood-brain barrier dysfunction and dysregulation of blood flow. Since dysfunction of astrocytes can contribute to epilepsy, we will also discuss their role as potential targets for new therapeutic strategies.
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Affiliation(s)
- Quirijn P. Verhoog
- Leiden Academic Center for Drug Research, Leiden University, Leiden, Netherlands
- Department of Neuropathology, Amsterdam Neuroscience, Amsterdam UMC, University of Amsterdam, Amsterdam, Netherlands
| | - Linda Holtman
- Leiden Academic Center for Drug Research, Leiden University, Leiden, Netherlands
| | - Eleonora Aronica
- Department of Neuropathology, Amsterdam Neuroscience, Amsterdam UMC, University of Amsterdam, Amsterdam, Netherlands
- Stichting Epilepsie Instellingen Nederland (SEIN), Heemstede, Netherlands
| | - Erwin A. van Vliet
- Department of Neuropathology, Amsterdam Neuroscience, Amsterdam UMC, University of Amsterdam, Amsterdam, Netherlands
- Center for Neuroscience, Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, Netherlands
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Glucose transporters in brain in health and disease. Pflugers Arch 2020; 472:1299-1343. [PMID: 32789766 PMCID: PMC7462931 DOI: 10.1007/s00424-020-02441-x] [Citation(s) in RCA: 219] [Impact Index Per Article: 54.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Revised: 07/20/2020] [Accepted: 07/24/2020] [Indexed: 12/15/2022]
Abstract
Energy demand of neurons in brain that is covered by glucose supply from the blood is ensured by glucose transporters in capillaries and brain cells. In brain, the facilitative diffusion glucose transporters GLUT1-6 and GLUT8, and the Na+-d-glucose cotransporters SGLT1 are expressed. The glucose transporters mediate uptake of d-glucose across the blood-brain barrier and delivery of d-glucose to astrocytes and neurons. They are critically involved in regulatory adaptations to varying energy demands in response to differing neuronal activities and glucose supply. In this review, a comprehensive overview about verified and proposed roles of cerebral glucose transporters during health and diseases is presented. Our current knowledge is mainly based on experiments performed in rodents. First, the functional properties of human glucose transporters expressed in brain and their cerebral locations are described. Thereafter, proposed physiological functions of GLUT1, GLUT2, GLUT3, GLUT4, and SGLT1 for energy supply to neurons, glucose sensing, central regulation of glucohomeostasis, and feeding behavior are compiled, and their roles in learning and memory formation are discussed. In addition, diseases are described in which functional changes of cerebral glucose transporters are relevant. These are GLUT1 deficiency syndrome (GLUT1-SD), diabetes mellitus, Alzheimer’s disease (AD), stroke, and traumatic brain injury (TBI). GLUT1-SD is caused by defect mutations in GLUT1. Diabetes and AD are associated with changed expression of glucose transporters in brain, and transporter-related energy deficiency of neurons may contribute to pathogenesis of AD. Stroke and TBI are associated with changes of glucose transporter expression that influence clinical outcome.
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Wang S, Wong LY, Neumann D, Liu Y, Sun A, Antoons G, Strzelecka A, Glatz JF, Nabben M, Luiken JJ. Augmenting Vacuolar H +-ATPase Function Prevents Cardiomyocytes from Lipid-Overload Induced Dysfunction. Int J Mol Sci 2020; 21:ijms21041520. [PMID: 32102213 PMCID: PMC7073192 DOI: 10.3390/ijms21041520] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2020] [Revised: 02/17/2020] [Accepted: 02/21/2020] [Indexed: 12/14/2022] Open
Abstract
The diabetic heart is characterized by a shift in substrate utilization from glucose to lipids, which may ultimately lead to contractile dysfunction. This substrate shift is facilitated by increased translocation of lipid transporter CD36 (SR-B2) from endosomes to the sarcolemma resulting in increased lipid uptake. We previously showed that endosomal retention of CD36 is dependent on the proper functioning of vacuolar H+-ATPase (v-ATPase). Excess lipids trigger CD36 translocation through inhibition of v-ATPase function. Conversely, in yeast, glucose availability is known to enhance v-ATPase function, allowing us to hypothesize that glucose availability, via v-ATPase, may internalize CD36 and restore contractile function in lipid-overloaded cardiomyocytes. Increased glucose availability was achieved through (a) high glucose (25 mM) addition to the culture medium or (b) adenoviral overexpression of protein kinase-D1 (a kinase mediating GLUT4 translocation). In HL-1 cardiomyocytes, adult rat and human cardiomyocytes cultured under high-lipid conditions, each treatment stimulated v-ATPase re-assembly, endosomal acidification, endosomal CD36 retention and prevented myocellular lipid accumulation. Additionally, these treatments preserved insulin-stimulated GLUT4 translocation and glucose uptake as well as contractile force. The present findings reveal v-ATPase functions as a key regulator of cardiomyocyte substrate preference and as a novel potential treatment approach for the diabetic heart.
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Affiliation(s)
- Shujin Wang
- Department of Genetics & Cell Biology, Faculty of Health, Medicine and Life Sciences, Maastricht University, 6200-MD Maastricht, The Netherlands; (S.W.); (L.-Y.W.); (Y.L.); (A.S.); (A.S.); (M.N.)
| | - Li-Yen Wong
- Department of Genetics & Cell Biology, Faculty of Health, Medicine and Life Sciences, Maastricht University, 6200-MD Maastricht, The Netherlands; (S.W.); (L.-Y.W.); (Y.L.); (A.S.); (A.S.); (M.N.)
- Department of Clinical Genetics, Maastricht University Medical Center+, 6200-MD Maastricht, The Netherlands
| | - Dietbert Neumann
- Departments of Pathology, CARIM School for Cardiovascular Diseases, Maastricht University, 6200-MD Maastricht, The Netherlands;
| | - Yilin Liu
- Department of Genetics & Cell Biology, Faculty of Health, Medicine and Life Sciences, Maastricht University, 6200-MD Maastricht, The Netherlands; (S.W.); (L.-Y.W.); (Y.L.); (A.S.); (A.S.); (M.N.)
| | - Aomin Sun
- Department of Genetics & Cell Biology, Faculty of Health, Medicine and Life Sciences, Maastricht University, 6200-MD Maastricht, The Netherlands; (S.W.); (L.-Y.W.); (Y.L.); (A.S.); (A.S.); (M.N.)
| | - Gudrun Antoons
- Departments of Physiology, CARIM School for Cardiovascular Diseases, Maastricht University, 6200-MD Maastricht, The Netherlands;
| | - Agnieszka Strzelecka
- Department of Genetics & Cell Biology, Faculty of Health, Medicine and Life Sciences, Maastricht University, 6200-MD Maastricht, The Netherlands; (S.W.); (L.-Y.W.); (Y.L.); (A.S.); (A.S.); (M.N.)
| | - Jan F.C. Glatz
- Department of Genetics & Cell Biology, Faculty of Health, Medicine and Life Sciences, Maastricht University, 6200-MD Maastricht, The Netherlands; (S.W.); (L.-Y.W.); (Y.L.); (A.S.); (A.S.); (M.N.)
- Department of Clinical Genetics, Maastricht University Medical Center+, 6200-MD Maastricht, The Netherlands
| | - Miranda Nabben
- Department of Genetics & Cell Biology, Faculty of Health, Medicine and Life Sciences, Maastricht University, 6200-MD Maastricht, The Netherlands; (S.W.); (L.-Y.W.); (Y.L.); (A.S.); (A.S.); (M.N.)
| | - Joost J.F.P. Luiken
- Department of Genetics & Cell Biology, Faculty of Health, Medicine and Life Sciences, Maastricht University, 6200-MD Maastricht, The Netherlands; (S.W.); (L.-Y.W.); (Y.L.); (A.S.); (A.S.); (M.N.)
- Correspondence: ; Tel.: +31-43 3881209
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Branca JJV, Maresca M, Morucci G, Mello T, Becatti M, Pazzagli L, Colzi I, Gonnelli C, Carrino D, Paternostro F, Nicoletti C, Ghelardini C, Gulisano M, Di Cesare Mannelli L, Pacini A. Effects of Cadmium on ZO-1 Tight Junction Integrity of the Blood Brain Barrier. Int J Mol Sci 2019; 20:E6010. [PMID: 31795317 PMCID: PMC6928912 DOI: 10.3390/ijms20236010] [Citation(s) in RCA: 48] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2019] [Revised: 11/21/2019] [Accepted: 11/26/2019] [Indexed: 02/06/2023] Open
Abstract
Cadmium (Cd) is a highly toxic environmental pollutant released from the smelting and refining of metals and cigarette smoking. Oral exposure to cadmium may result in adverse effects on a number of tissues, including the central nervous system (CNS). In fact, its toxicity has been related to neurological disorders, as well as neurodegenerative diseases such as Alzheimer's and Parkinson's diseases. Under normal conditions, Cd barely reaches the brain in adults because of the presence of the blood-brain barrier (BBB); however, it has been demonstrated that Cd-dependent BBB alteration contributes to pathogenesis of neurodegeneration. However, the mechanism underlying Cd-dependent BBB alteration remain obscure. Here, we investigated the signaling pathway of Cd-induced tight junction (TJ), F-actin, and vimentin protein disassembly in a rat brain endothelial cell line (RBE4). RBE4 cells treated with 10 μM cadmium chloride (CdCl2) showed a dose- and time-dependent significant increase in reactive oxygen species (ROS) production. This phenomenon was coincident with the alteration of the TJ zonula occludens-1 (ZO-1), F-actin, and vimentin proteins. The Cd-dependent ROS increase elicited the upregulation of GRP78 expression levels, a chaperone involved in endoplasmic reticulum (ER) stress that induces caspase-3 activation. Further signal profiling by the pannexin-1 (PANX1) specific inhibitor 10Panx revealed a PANX1-independent increase in ATP spillage in Cd-treated endothelial cells. Our results point out that a ROS-dependent ER stress-mediated signaling pathway involving caspase-3 activation and ATP release is behind the BBB morphological alterations induced by Cd.
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Affiliation(s)
- Jacopo Junio Valerio Branca
- Department of Experimental and Clinical Medicine, Anatomy and Histology Section, University of Florence, 50134 Florence, Italy; (G.M.); (D.C.); (F.P.); (C.N.); (M.G.)
| | - Mario Maresca
- Department of Neuroscience, Psychology, Drug Research and Child Health (NEUROFARBA), Pharmacology and Toxicology Section, University of Florence, 50139 Florence, Italy; (M.M.); (C.G.); (L.D.C.M.)
| | - Gabriele Morucci
- Department of Experimental and Clinical Medicine, Anatomy and Histology Section, University of Florence, 50134 Florence, Italy; (G.M.); (D.C.); (F.P.); (C.N.); (M.G.)
| | - Tommaso Mello
- Department of Experimental and Clinical Biomedical Sciences “Mario Serio”, University of Florence, 50134 Florence, Italy; (T.M.); (M.B.); (L.P.)
| | - Matteo Becatti
- Department of Experimental and Clinical Biomedical Sciences “Mario Serio”, University of Florence, 50134 Florence, Italy; (T.M.); (M.B.); (L.P.)
| | - Luigia Pazzagli
- Department of Experimental and Clinical Biomedical Sciences “Mario Serio”, University of Florence, 50134 Florence, Italy; (T.M.); (M.B.); (L.P.)
| | - Ilaria Colzi
- Department of Biology, Plant Ecology and Physiology Laboratory, University of Florence, 50121 Florence, Italy; (I.C.); (C.G.)
| | - Cristina Gonnelli
- Department of Biology, Plant Ecology and Physiology Laboratory, University of Florence, 50121 Florence, Italy; (I.C.); (C.G.)
| | - Donatello Carrino
- Department of Experimental and Clinical Medicine, Anatomy and Histology Section, University of Florence, 50134 Florence, Italy; (G.M.); (D.C.); (F.P.); (C.N.); (M.G.)
| | - Ferdinando Paternostro
- Department of Experimental and Clinical Medicine, Anatomy and Histology Section, University of Florence, 50134 Florence, Italy; (G.M.); (D.C.); (F.P.); (C.N.); (M.G.)
| | - Claudio Nicoletti
- Department of Experimental and Clinical Medicine, Anatomy and Histology Section, University of Florence, 50134 Florence, Italy; (G.M.); (D.C.); (F.P.); (C.N.); (M.G.)
| | - Carla Ghelardini
- Department of Neuroscience, Psychology, Drug Research and Child Health (NEUROFARBA), Pharmacology and Toxicology Section, University of Florence, 50139 Florence, Italy; (M.M.); (C.G.); (L.D.C.M.)
| | - Massimo Gulisano
- Department of Experimental and Clinical Medicine, Anatomy and Histology Section, University of Florence, 50134 Florence, Italy; (G.M.); (D.C.); (F.P.); (C.N.); (M.G.)
| | - Lorenzo Di Cesare Mannelli
- Department of Neuroscience, Psychology, Drug Research and Child Health (NEUROFARBA), Pharmacology and Toxicology Section, University of Florence, 50139 Florence, Italy; (M.M.); (C.G.); (L.D.C.M.)
| | - Alessandra Pacini
- Department of Experimental and Clinical Medicine, Anatomy and Histology Section, University of Florence, 50134 Florence, Italy; (G.M.); (D.C.); (F.P.); (C.N.); (M.G.)
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Moura RP, Martins C, Pinto S, Sousa F, Sarmento B. Blood-brain barrier receptors and transporters: an insight on their function and how to exploit them through nanotechnology. Expert Opin Drug Deliv 2019; 16:271-285. [PMID: 30767695 DOI: 10.1080/17425247.2019.1583205] [Citation(s) in RCA: 66] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
INTRODUCTION The blood-brain barrier (BBB) is a highly limiting barrier that prevents the brain from contacting with several circulating molecules, including harmful agents. However, certain systemic nutrients and macromolecules are able to cross the BBB and reach the brain parenchyma, involving the interaction with multiple receptors and/or transporters at the BBB surface. Nanotechnology allows the creation of drug vehicles, functionalized with targeting ligands for binding specific BBB receptors and/or transporters, hence triggering the transport through this biobarrier. AREAS COVERED This review focuses the BBB receptors/transporters to be exploited in regard to their overall structure and biologic function, as well as their role in the development of strategies envisaging drug delivery to the brain. Then, the interplay between the targeting of these BBB receptors/transporters and nanotechnology is explored, as they can increase by several-fold the effectiveness of brain-targeted therapies. EXPERT OPINION Nanomedicine may be particularly useful in brain drug delivery, mainly due to the possibility of functionalizing nanoparticles to target specific receptors/transporters. Since the BBB is endowed with numerous receptors and transporters responsible for regulating the proper metabolic activity of the brain, their targeting can be a promising bypass strategy to circumvent the hurdle that the BBB represents for brain drug delivery.
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Affiliation(s)
- Rui Pedro Moura
- a CESPU - Instituto de Investigação e Formação Avançada em Ciências e Tecnologias da Saúde , Gandra , Portugal
| | - Cláudia Martins
- b I3S - Instituto de Investigação e Inovação em Saúde , Universidade do Porto , Porto , Portugal.,c INEB - Instituto de Engenharia Biomédica , Universidade do Porto , Porto , Portugal.,d ICBAS - Instituto de Ciências Biomédicas Abel Salazar , Universidade do Porto , Porto , Portugal
| | - Soraia Pinto
- b I3S - Instituto de Investigação e Inovação em Saúde , Universidade do Porto , Porto , Portugal.,c INEB - Instituto de Engenharia Biomédica , Universidade do Porto , Porto , Portugal
| | - Flávia Sousa
- a CESPU - Instituto de Investigação e Formação Avançada em Ciências e Tecnologias da Saúde , Gandra , Portugal.,b I3S - Instituto de Investigação e Inovação em Saúde , Universidade do Porto , Porto , Portugal.,c INEB - Instituto de Engenharia Biomédica , Universidade do Porto , Porto , Portugal.,d ICBAS - Instituto de Ciências Biomédicas Abel Salazar , Universidade do Porto , Porto , Portugal
| | - Bruno Sarmento
- a CESPU - Instituto de Investigação e Formação Avançada em Ciências e Tecnologias da Saúde , Gandra , Portugal.,b I3S - Instituto de Investigação e Inovação em Saúde , Universidade do Porto , Porto , Portugal.,c INEB - Instituto de Engenharia Biomédica , Universidade do Porto , Porto , Portugal
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Veszelka S, Tóth A, Walter FR, Tóth AE, Gróf I, Mészáros M, Bocsik A, Hellinger É, Vastag M, Rákhely G, Deli MA. Comparison of a Rat Primary Cell-Based Blood-Brain Barrier Model With Epithelial and Brain Endothelial Cell Lines: Gene Expression and Drug Transport. Front Mol Neurosci 2018; 11:166. [PMID: 29872378 PMCID: PMC5972182 DOI: 10.3389/fnmol.2018.00166] [Citation(s) in RCA: 74] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2017] [Accepted: 05/01/2018] [Indexed: 01/16/2023] Open
Abstract
Cell culture-based blood-brain barrier (BBB) models are useful tools for screening of CNS drug candidates. Cell sources for BBB models include primary brain endothelial cells or immortalized brain endothelial cell lines. Despite their well-known differences, epithelial cell lines are also used as surrogate models for testing neuropharmaceuticals. The aim of the present study was to compare the expression of selected BBB related genes including tight junction proteins, solute carriers (SLC), ABC transporters, metabolic enzymes and to describe the paracellular properties of nine different culture models. To establish a primary BBB model rat brain capillary endothelial cells were co-cultured with rat pericytes and astrocytes (EPA). As other BBB and surrogate models four brain endothelial cells lines, rat GP8 and RBE4 cells, and human hCMEC/D3 cells with or without lithium treatment (D3 and D3L), and four epithelial cell lines, native human intestinal Caco-2 and high P-glycoprotein expressing vinblastine-selected VB-Caco-2 cells, native MDCK and MDR1 transfected MDCK canine kidney cells were used. To test transporter functionality, the permeability of 12 molecules, glucopyranose, valproate, baclofen, gabapentin, probenecid, salicylate, rosuvastatin, pravastatin, atorvastatin, tacrine, donepezil, was also measured in the EPA and epithelial models. Among the junctional protein genes, the expression level of occludin was high in all models except the GP8 and RBE4 cells, and each model expressed a unique claudin pattern. Major BBB efflux (P-glycoprotein or ABCB1) and influx transporters (GLUT-1, LAT-1) were present in all models at mRNA levels. The transcript of BCRP (ABCG2) was not expressed in MDCK, GP8 and RBE4 cells. The absence of gene expression of important BBB efflux and influx transporters BCRP, MRP6, -9, MCT6, -8, PHT2, OATPs in one or both types of epithelial models suggests that Caco-2 or MDCK models are not suitable to test drug candidates which are substrates of these transporters. Brain endothelial cell lines GP8, RBE4, D3 and D3L did not form a restrictive paracellular barrier necessary for screening small molecular weight pharmacons. Therefore, among the tested culture models, the primary cell-based EPA model is suitable for the functional analysis of the BBB.
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Affiliation(s)
- Szilvia Veszelka
- Biological Barriers Research Group, Institute of Biophysics, Biological Research Centre, Hungarian Academy of Sciences, Szeged, Hungary
| | - András Tóth
- Biological Barriers Research Group, Institute of Biophysics, Biological Research Centre, Hungarian Academy of Sciences, Szeged, Hungary.,Department of Biotechnology, Faculty of Science and Informatics, University of Szeged, Szeged, Hungary
| | - Fruzsina R Walter
- Biological Barriers Research Group, Institute of Biophysics, Biological Research Centre, Hungarian Academy of Sciences, Szeged, Hungary
| | - Andrea E Tóth
- Biological Barriers Research Group, Institute of Biophysics, Biological Research Centre, Hungarian Academy of Sciences, Szeged, Hungary
| | - Ilona Gróf
- Biological Barriers Research Group, Institute of Biophysics, Biological Research Centre, Hungarian Academy of Sciences, Szeged, Hungary.,Doctoral School in Biology, Faculty of Science and Informatics, University of Szeged, Szeged, Hungary
| | - Mária Mészáros
- Biological Barriers Research Group, Institute of Biophysics, Biological Research Centre, Hungarian Academy of Sciences, Szeged, Hungary.,Doctoral School in Theoretical Medicine, Faculty of Medicine, University of Szeged, Szeged, Hungary
| | - Alexandra Bocsik
- Biological Barriers Research Group, Institute of Biophysics, Biological Research Centre, Hungarian Academy of Sciences, Szeged, Hungary
| | - Éva Hellinger
- In Vitro Metabolism Research, Division of Pharmacology and Drug Safety, Gedeon Richter Plc., Budapest, Hungary
| | - Monika Vastag
- In Vitro Metabolism Research, Division of Pharmacology and Drug Safety, Gedeon Richter Plc., Budapest, Hungary
| | - Gábor Rákhely
- Biological Barriers Research Group, Institute of Biophysics, Biological Research Centre, Hungarian Academy of Sciences, Szeged, Hungary.,Department of Biotechnology, Faculty of Science and Informatics, University of Szeged, Szeged, Hungary
| | - Mária A Deli
- Biological Barriers Research Group, Institute of Biophysics, Biological Research Centre, Hungarian Academy of Sciences, Szeged, Hungary
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Nałęcz KA. Solute Carriers in the Blood–Brain Barier: Safety in Abundance. Neurochem Res 2016; 42:795-809. [DOI: 10.1007/s11064-016-2030-x] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2016] [Revised: 07/29/2016] [Accepted: 08/02/2016] [Indexed: 12/22/2022]
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12
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Immortalized endothelial cell lines for in vitro blood–brain barrier models: A systematic review. Brain Res 2016; 1642:532-545. [DOI: 10.1016/j.brainres.2016.04.024] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2016] [Revised: 04/05/2016] [Accepted: 04/12/2016] [Indexed: 12/18/2022]
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13
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Carreras FJ, Aranda CJ, Porcel D, Rodriguez-Hurtado F, Martínez-Agustin O, Zarzuelo A. Expression of glucose transporters in the prelaminar region of the optic-nerve head of the pig as determined by immunolabeling and tissue culture. PLoS One 2015; 10:e0128516. [PMID: 26030125 PMCID: PMC4452482 DOI: 10.1371/journal.pone.0128516] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2014] [Accepted: 04/28/2015] [Indexed: 11/26/2022] Open
Abstract
Background To develop the use of cultured tissue of the prelaminar optic nerve of the pig to explore possible alterations of the astrocyte-axon metabolic pathways in glaucoma, we map the distribution of the glucose transporters GLUT1 and GLUT3 in fresh and cultured tissue. Methods We monitor cell survival in cultures of the prelaminar optic-nerve tissue, measuring necrosis and apoptosis markers biochemically as well as morphologically, and establish the presence of the glucose transporters GLUT1 and GLUT3. We map the distribution of these transporters with immunolabeling in histological sections of the optic nerve using confocal and electronic transmission microscopy. Results We find that the main death type in prelaminar culture is apoptosis. Caspase 7 staining reveals an increment in apoptosis from day 1 to day 4 and a reduction from day 4 to day 8. Western blotting for GLUT1 shows stability with increased culture time. CLSM micrographs locate GLUT1 in the columnar astrocytes and in the area of axonal bundles. Anti-GLUT3 predominantly labels axonal bundles. TEM immunolabeling with colloidal gold displays a very specific distribution of GLUT-1 in the membranes of vascular endothelial cells and in periaxonal astrocyte expansions. The GLUT-3 isoform is observed with TEM only in axons in the axonal bundles. Conclusions Tissue culture is suitable for apoptosis-induction experiments. The results suggest that glucose is transported to the axonal cleft intracytoplasmically and delivered to the cleft by GLUT1 transporters. As monocarboxylate transporters have been reported in the prelaminar region of the optic-nerve head, this area is likely to use both lactate and glucose as energy sources.
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Affiliation(s)
- F. Javier Carreras
- Department of Surgery (Ophthalmology), Faculty of Medicine, University of Granada, Granada, Spain
- * E-mail:
| | - Carlos J. Aranda
- Department of Biochemistry and Molecular Biology II, Faculty of Pharmacy, University of Granada, Granada, Spain
| | - David Porcel
- Center of Scientific Instrumentation, University of Granada, Granada, Spain
| | | | - Olga Martínez-Agustin
- Department of Biochemistry and Molecular Biology II, Faculty of Pharmacy, University of Granada, and Networked Biomedical Research Center for Hepatic and Digestive Diseases (CIBEREHD), Granada, Spain
| | - Antonio Zarzuelo
- Department of Pharmacology, Faculty of Pharmacy, University of Granada, and Networked Biomedical Research Center for Hepatic and Digestive Diseases (CIBEREHD), Granada, Spain
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14
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Campos-Bedolla P, Walter FR, Veszelka S, Deli MA. Role of the Blood–Brain Barrier in the Nutrition of the Central Nervous System. Arch Med Res 2014; 45:610-38. [DOI: 10.1016/j.arcmed.2014.11.018] [Citation(s) in RCA: 114] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2014] [Accepted: 11/24/2014] [Indexed: 12/22/2022]
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15
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Affiliation(s)
- Yarong He
- From the Emergency Department, West China Hospital, Sichuan University, Chengdu, Sichuan, People's Republic of China (Y.H., Y.C.); Laboratory of Neurobiology and Genetics, The Rockefeller University, New York, NY (Y.Y.); and Department of Pharmacological Sciences, Stony Brook University, NY (S.E.T.)
| | - Yao Yao
- From the Emergency Department, West China Hospital, Sichuan University, Chengdu, Sichuan, People's Republic of China (Y.H., Y.C.); Laboratory of Neurobiology and Genetics, The Rockefeller University, New York, NY (Y.Y.); and Department of Pharmacological Sciences, Stony Brook University, NY (S.E.T.)
| | - Stella E Tsirka
- From the Emergency Department, West China Hospital, Sichuan University, Chengdu, Sichuan, People's Republic of China (Y.H., Y.C.); Laboratory of Neurobiology and Genetics, The Rockefeller University, New York, NY (Y.Y.); and Department of Pharmacological Sciences, Stony Brook University, NY (S.E.T.)
| | - Yu Cao
- From the Emergency Department, West China Hospital, Sichuan University, Chengdu, Sichuan, People's Republic of China (Y.H., Y.C.); Laboratory of Neurobiology and Genetics, The Rockefeller University, New York, NY (Y.Y.); and Department of Pharmacological Sciences, Stony Brook University, NY (S.E.T.).
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16
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Bianco AC, Anderson G, Forrest D, Galton VA, Gereben B, Kim BW, Kopp PA, Liao XH, Obregon MJ, Peeters RP, Refetoff S, Sharlin DS, Simonides WS, Weiss RE, Williams GR. American Thyroid Association Guide to investigating thyroid hormone economy and action in rodent and cell models. Thyroid 2014; 24:88-168. [PMID: 24001133 PMCID: PMC3887458 DOI: 10.1089/thy.2013.0109] [Citation(s) in RCA: 143] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
BACKGROUND An in-depth understanding of the fundamental principles that regulate thyroid hormone homeostasis is critical for the development of new diagnostic and treatment approaches for patients with thyroid disease. SUMMARY Important clinical practices in use today for the treatment of patients with hypothyroidism, hyperthyroidism, or thyroid cancer are the result of laboratory discoveries made by scientists investigating the most basic aspects of thyroid structure and molecular biology. In this document, a panel of experts commissioned by the American Thyroid Association makes a series of recommendations related to the study of thyroid hormone economy and action. These recommendations are intended to promote standardization of study design, which should in turn increase the comparability and reproducibility of experimental findings. CONCLUSIONS It is expected that adherence to these recommendations by investigators in the field will facilitate progress towards a better understanding of the thyroid gland and thyroid hormone dependent processes.
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Affiliation(s)
- Antonio C. Bianco
- Division of Endocrinology, Diabetes and Metabolism, University of Miami Miller School of Medicine, Miami, Florida
| | - Grant Anderson
- Department of Pharmacy Practice and Pharmaceutical Sciences, College of Pharmacy, University of Minnesota Duluth, Duluth, Minnesota
| | - Douglas Forrest
- Laboratory of Endocrinology and Receptor Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland
| | - Valerie Anne Galton
- Department of Physiology and Neurobiology, Dartmouth Medical School, Lebanon, New Hampshire
| | - Balázs Gereben
- Department of Endocrine Neurobiology, Institute of Experimental Medicine, Hungarian Academy of Sciences, Budapest, Hungary
| | - Brian W. Kim
- Division of Endocrinology, Diabetes and Metabolism, University of Miami Miller School of Medicine, Miami, Florida
| | - Peter A. Kopp
- Division of Endocrinology, Metabolism, and Molecular Medicine, and Center for Genetic Medicine, Feinberg School of Medicine, Northwestern University, Chicago, Illinois
| | - Xiao Hui Liao
- Section of Adult and Pediatric Endocrinology, Diabetes, and Metabolism, The University of Chicago, Chicago, Illinois
| | - Maria Jesus Obregon
- Institute of Biomedical Investigation (IIB), Spanish National Research Council (CSIC) and Autonomous University of Madrid, Madrid, Spain
| | - Robin P. Peeters
- Division of Endocrinology, Department of Internal Medicine, Erasmus Medical Center, Rotterdam, The Netherlands
| | - Samuel Refetoff
- Section of Adult and Pediatric Endocrinology, Diabetes, and Metabolism, The University of Chicago, Chicago, Illinois
| | - David S. Sharlin
- Department of Biological Sciences, Minnesota State University, Mankato, Minnesota
| | - Warner S. Simonides
- Laboratory for Physiology, Institute for Cardiovascular Research, VU University Medical Center, Amsterdam, The Netherlands
| | - Roy E. Weiss
- Section of Adult and Pediatric Endocrinology, Diabetes, and Metabolism, The University of Chicago, Chicago, Illinois
| | - Graham R. Williams
- Department of Medicine, Imperial College London, Hammersmith Campus, London, United Kingdom
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17
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Minagar A, Maghzi AH, McGee JC, Alexander JS. Emerging roles of endothelial cells in multiple sclerosis pathophysiology and therapy. Neurol Res 2012; 34:738-45. [PMID: 22828184 DOI: 10.1179/1743132812y.0000000072] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Although multiple sclerosis (MS) has traditionally been viewed and researched as an immune-mediated demyelinating and neurodegenerative disease of the human central nervous system (CNS), its highly complex pathogenesis clearly includes a significant vascular inflammatory component and many therapeutic approaches achieve benefit by direct or indirect effects on cerebrovascular endothelial cells. Cerebral endothelial cells create and separate the compartments of the peripheral circulation and CNS creating the blood-brain barrier (BBB), a selectively permeable boundary layer between these spaces. Interactions between activated leukocytes and cerebral endothelium play essential roles in mediating their trans-BBB diapedesis during normal immune surveillance and during pathogenesis of neuroinflammatory diseases like MS. Extravasation of activated and committed leukocytes from the peripheral circulation through the endothelial layer of the BBB into the CNS milieu is the most fundamental step in formation of MS lesions. During MS pathogenesis, once the activated leukocytes enter the CNS environment, they propagate a massive wave of destruction which culminates in the loss of both myelin/oligodendrocyte complex and neurodegeneration. Multiple clinical and basic scientific observations support endothelial cell 'stress' and apoptosis as a hallmark characteristic of MS. The manipulation of the endothelial biology aiming to block trans-endothelial migration of activated immune cells into the CNS is a potent form of treatment for MS achieving significant reductions in disease activity and new lesion formation. In particular, endothelial microparticles are now well-recognized as important biomarkers and mediators of this type of stress. In this review, we discuss recent findings and new advances in our knowledge regarding leukocyte migration through the endothelial frontier of the BBB and how this can be exploited toward treating MS patients.
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18
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Cura AJ, Carruthers A. AMP kinase regulation of sugar transport in brain capillary endothelial cells during acute metabolic stress. Am J Physiol Cell Physiol 2012; 303:C806-14. [PMID: 22763120 DOI: 10.1152/ajpcell.00437.2011] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
AMP-dependent kinase (AMPK) and GLUT1-mediated sugar transport in blood-brain barrier endothelial cells are activated during acute cellular metabolic stress. Using murine brain microvasculature endothelium bEnd.3 cells, we show that AMPK phosphorylation and stimulation of 3-O-methylglucose transport by the AMPK agonist AICAR are inhibited in a dose-dependent manner by the AMPK antagonist Compound C. AMPK α1- or AMPK α2-knockdown by RNA interference or AMPK inhibition by Compound C reduces AMPK phosphorylation and 3-O-methylglucose transport stimulation induced by cellular glucose-depletion, by potassium cyanide (KCN), or by carbonyl cyanide-p-trifluoromethoxy-phenylhydrazone (FCCP). Cell surface biotinylation studies reveal that plasma membrane GLUT1 levels are increased two- to threefold by cellular glucose depletion, AICAR or KCN treatment, and that these increases are prevented by Compound C and by AMPK α1- or α2-knockdown. These results support the hypothesis that AMPK activation in blood-brain barrier-derived endothelial cells directs the trafficking of GLUT1 intracellular pools to the plasma membrane, thereby increasing endothelial sugar transport capacity.
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Affiliation(s)
- Anthony J Cura
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, USA
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19
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Redzic Z. Molecular biology of the blood-brain and the blood-cerebrospinal fluid barriers: similarities and differences. Fluids Barriers CNS 2011; 8:3. [PMID: 21349151 PMCID: PMC3045361 DOI: 10.1186/2045-8118-8-3] [Citation(s) in RCA: 251] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2010] [Accepted: 01/18/2011] [Indexed: 01/11/2023] Open
Abstract
Efficient processing of information by the central nervous system (CNS) represents an important evolutionary advantage. Thus, homeostatic mechanisms have developed that provide appropriate circumstances for neuronal signaling, including a highly controlled and stable microenvironment. To provide such a milieu for neurons, extracellular fluids of the CNS are separated from the changeable environment of blood at three major interfaces: at the brain capillaries by the blood-brain barrier (BBB), which is localized at the level of the endothelial cells and separates brain interstitial fluid (ISF) from blood; at the epithelial layer of four choroid plexuses, the blood-cerebrospinal fluid (CSF) barrier (BCSFB), which separates CSF from the CP ISF, and at the arachnoid barrier. The two barriers that represent the largest interface between blood and brain extracellular fluids, the BBB and the BCSFB, prevent the free paracellular diffusion of polar molecules by complex morphological features, including tight junctions (TJs) that interconnect the endothelial and epithelial cells, respectively. The first part of this review focuses on the molecular biology of TJs and adherens junctions in the brain capillary endothelial cells and in the CP epithelial cells. However, normal function of the CNS depends on a constant supply of essential molecules, like glucose and amino acids from the blood, exchange of electrolytes between brain extracellular fluids and blood, as well as on efficient removal of metabolic waste products and excess neurotransmitters from the brain ISF. Therefore, a number of specific transport proteins are expressed in brain capillary endothelial cells and CP epithelial cells that provide transport of nutrients and ions into the CNS and removal of waste products and ions from the CSF. The second part of this review concentrates on the molecular biology of various solute carrier (SLC) transport proteins at those two barriers and underlines differences in their expression between the two barriers. Also, many blood-borne molecules and xenobiotics can diffuse into brain ISF and then into neuronal membranes due to their physicochemical properties. Entry of these compounds could be detrimental for neural transmission and signalling. Thus, BBB and BCSFB express transport proteins that actively restrict entry of lipophilic and amphipathic substances from blood and/or remove those molecules from the brain extracellular fluids. The third part of this review concentrates on the molecular biology of ATP-binding cassette (ABC)-transporters and those SLC transporters that are involved in efflux transport of xenobiotics, their expression at the BBB and BCSFB and differences in expression in the two major blood-brain interfaces. In addition, transport and diffusion of ions by the BBB and CP epithelium are involved in the formation of fluid, the ISF and CSF, respectively, so the last part of this review discusses molecular biology of ion transporters/exchangers and ion channels in the brain endothelial and CP epithelial cells.
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Affiliation(s)
- Zoran Redzic
- Department of Physiology, Faculty of Medicine, Kuwait University, SAFAT 13110, Kuwait.
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20
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Strilić B, Kucera T, Lammert E. Formation of cardiovascular tubes in invertebrates and vertebrates. Cell Mol Life Sci 2010; 67:3209-18. [PMID: 20490602 PMCID: PMC11115780 DOI: 10.1007/s00018-010-0400-0] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2010] [Revised: 04/17/2010] [Accepted: 05/03/2010] [Indexed: 12/13/2022]
Abstract
The cardiovascular system developed early in evolution and is pivotal for the transport of oxygen, nutrients, and waste products within the organism. It is composed of hollow tubular structures and has a high level of complexity in vertebrates. This complexity is, at least in part, due to the endothelial cell lining of vertebrate blood vessels. However, vascular lumen formation by endothelial cells is still controversially discussed. For example, it has been suggested that the lumen mainly forms via coalescence of large intracellular vacuoles generated by pinocytosis. Alternatively, it was proposed that the vascular lumen initiates extracellularly between adjacent apical endothelial cell surfaces. Here we discuss invertebrate and vertebrate cardiovascular lumen formation and highlight the possible modes of blood vessel formation. Finally, we point to the importance of a better understanding of vascular lumen formation for treating human pathologies, including cancer and coronary heart disease.
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Affiliation(s)
- Boris Strilić
- Institute of Metabolic Physiology, Heinrich-Heine-University Düsseldorf, 40225 Düsseldorf, Germany.
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21
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Miecz D, Januszewicz E, Czeredys M, Hinton BT, Berezowski V, Cecchelli R, Nałecz KA. Localization of organic cation/carnitine transporter (OCTN2) in cells forming the blood-brain barrier. J Neurochem 2007; 104:113-23. [PMID: 17995936 DOI: 10.1111/j.1471-4159.2007.05024.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Carnitine beta-hydroxy-gamma-(trimethylammonio)butyrate - a compound necessary in the peripheral tissues for a transfer of fatty acids for their oxidation within the cell, accumulates in the brain despite low beta-oxidation in this organ. In order to enter the brain, carnitine has to cross the blood-brain barrier formed by capillary endothelial cells which are in close interaction with astrocytes. Previous studies, demonstrating expression of mRNA coding two carnitine transporters - organic cation/carnitine transporter 2 (OCTN2) and B(0,+) in endothelial cells, did not give any information on carnitine transporters polarity in endothelium. Therefore more detailed experiments were performed on expression and localization of a high affinity carnitine transporter OCTN2 in an in vitro model of the blood-brain barrier by real-time PCR, western blot analysis, and immunocytochemistry. The amount of mRNA was comparable in endothelial cells and kidney, when referred to house-keeping genes, it was, however, significantly lower in astrocytes. Polarity of OCTN2 localization was further studied in an in vitro model of the blood-brain barrier with use of anti-OCTN2 antibodies. Z-axis analysis of the confocal microscope pictures of endothelial cells, with anti-P-glycoprotein antibodies as the marker of apical membrane, showed OCTN2 localization at the basolateral membrane and in the cytoplasmic region in the vicinity of nuclei. Localization of OCTN2 suggest that carnitine can be also transported from the brain, playing an important role in removal of certain acyl esters.
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Affiliation(s)
- Dorota Miecz
- Nencki Institute of Experimental Biology, Warszawa, Poland
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22
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Lok J, Gupta P, Guo S, Kim WJ, Whalen MJ, van Leyen K, Lo EH. Cell-cell signaling in the neurovascular unit. Neurochem Res 2007; 32:2032-45. [PMID: 17457674 DOI: 10.1007/s11064-007-9342-9] [Citation(s) in RCA: 165] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2007] [Accepted: 03/23/2007] [Indexed: 12/13/2022]
Abstract
Historically, the neuron has been the conceptual focus for almost all of neuroscience research. In recent years, however, the concept of the neurovascular unit has emerged as a new paradigm for investigating both physiology and pathology in the CNS. This concept proposes that a purely neurocentric focus is not sufficient, and emphasizes that all cell types in the brain including neuronal, glial and vascular components, must be examined in an integrated context. Cell-cell signaling and coupling between these different compartments form the basis for normal function. Disordered signaling and perturbed coupling form the basis for dysfunction and disease. In this mini-review, we will survey four examples of this phenomenon: hemodynamic neurovascular coupling linking blood flow to brain activity; cellular communications that evoke the blood-brain barrier phenotype; parallel systems that underlie both neurogenesis and angiogenesis in the CNS; and finally, the potential exchange of trophic factors that may link neuronal, glial and vascular homeostasis.
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Affiliation(s)
- Josephine Lok
- Neuroprotection Research Laboratory, Department of Radiology, Massachusetts General Hospital, MGH East 149-2401, Charlestown, MA 02129, USA
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23
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Perrière N, Yousif S, Cazaubon S, Chaverot N, Bourasset F, Cisternino S, Declèves X, Hori S, Terasaki T, Deli M, Scherrmann JM, Temsamani J, Roux F, Couraud PO. A functional in vitro model of rat blood-brain barrier for molecular analysis of efflux transporters. Brain Res 2007; 1150:1-13. [PMID: 17434463 DOI: 10.1016/j.brainres.2007.02.091] [Citation(s) in RCA: 118] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2006] [Revised: 02/09/2007] [Accepted: 02/11/2007] [Indexed: 11/15/2022]
Abstract
Physiological studies of the blood-brain barrier (BBB) are often performed in rats. We describe the functional characterization of a reproducible in vitro model of the rat BBB and its validation for investigating mechanisms involved in BBB regulation. Puromycin-purified primary cultures of brain endothelial cells, co-cultured with astrocytes in the presence of hydrocortisone (HC) and cAMP, presented low sucrose permeability (< or =0.1 x 10(-3) cm/min) and high transendothelial electrical resistance (> or =270 Omega cm(2)). Expression of specific BBB markers and their transcripts was detected by immunostaining and RT-PCR, respectively: tight junction proteins (claudin-3 and -5, ZO-1 and occludin) and transporters (P-gp, Bcrp and Oatp-2). RT-PCR experiments demonstrated a role of treatment by astrocytes, HC and cAMP in regulation of the transcript level of tight junction proteins (claudin-5 and ZO-1) as well as transporters (Mdr1a, Mrp3, Mrp4, Bcrp, Glut-1), while transcript level of Mdr1b was significantly decreased. The functionality of efflux pumps (P-gp, Mrps and Bcrp) was demonstrated in the presence of specific inhibitors (PSC833, MK571 or Ko143, respectively) by (i) assessing the uptake of the common substrates rhodamine 123 and daunorubicin and (ii) evaluating apical to basolateral and basolateral to apical polarized transport of daunorubicin. In addition, a good correlation (R=0.94) was obtained between the permeability coefficients of a series of compounds of various lipophilicity and their corresponding in vivo rodent blood-brain transfer coefficients. Taken together, our results provide compelling evidence that puromycin-purified rat brain endothelial cells constitute a reliable model of the rat BBB for physiological and pharmacological characterization of BBB transporters.
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Affiliation(s)
- Nicolas Perrière
- Institut Cochin, Département Biologie Cellulaire, Paris 75014, France.
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24
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Kemper EM, Leenders W, Küsters B, Lyons S, Buckle T, Heerschap A, Boogerd W, Beijnen JH, van Tellingen O. Development of luciferase tagged brain tumour models in mice for chemotherapy intervention studies. Eur J Cancer 2006; 42:3294-303. [PMID: 17027258 DOI: 10.1016/j.ejca.2006.07.013] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2006] [Accepted: 07/26/2006] [Indexed: 10/24/2022]
Abstract
The blood-brain barrier (BBB) is considered one of the major causes for the low efficacy of cytotoxic compounds against primary brain tumours. The aim of this study was to develop intracranial tumour models in mice featuring intact or locally disrupted BBB properties, which can be used in testing chemotherapy against brain tumours. These tumours were established by intracranial injection of suspensions of different tumour cell lines. All cell lines had been transfected with luciferase to allow non-invasive imaging of tumour development using a super-cooled CCD-camera. Following their implantation, tumours developed which displayed the infiltrative, invasive or expansive growth patterns that are also found in primary brain cancer or brain metastases. Contrast-enhanced magnetic resonance imaging showed that the Mel57, K1735Br2 and RG-2 lesions grow without disruption of the BBB, whereas the BBB was leaky in the U87MG and VEGF-A-transfected Mel57 lesions. This was confirmed by immunohistochemistry. Bioluminescence measurements allowed the visualisation of tumour burden already within 4 days after injection of the tumour cells. The applicability of our models for performing efficacy studies was demonstrated in an experiment using temozolomide as study drug. In conclusion, we have developed experimental brain tumour models with partly disrupted, or completely intact BBB properties. In vivo imaging by luciferase allows convenient follow-up of tumour growth and these models will be useful for chemotherapeutic intervention studies.
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Affiliation(s)
- E M Kemper
- Department of Clinical Chemistry, The Netherlands Cancer Institute/Antoni van Leeuwenhoek Huis, Plesmanlaan 121, 1066 CX Amsterdam, The Netherlands
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25
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Hundal Ø. Major depressive disorder viewed as a dysfunction in astroglial bioenergetics. Med Hypotheses 2006; 68:370-7. [PMID: 16978794 DOI: 10.1016/j.mehy.2006.06.050] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2006] [Revised: 06/13/2006] [Accepted: 06/15/2006] [Indexed: 12/21/2022]
Abstract
For many years scientists and physicians have pondered upon the apparent connection between depressive disorder and diabetes mellitus. Several epidemiologic studies confirm that diabetics have increased incidence of depression, and vice versa. In addition: depressive, non-diabetic patients have several insulin- and glucose-metabolism disturbances, probably exerting a compensatory reaction to the malfunction in the depressed brain as these disturbances are normalised in remission. After the discovery of PET-scanning, such studies have shown that patients with depressive disorder have reduced glucose metabolism in frontal parts of the brain. The present hypothesis regards the PET findings as observations of the primary pathophysiology of depression. Furthermore: two studies of post mortem samples from depressed patients show reduced numbers of astroglia. This is in accordance to the mentioned insulin disturbances, as only astroglia, not neurons, have insulin-sensitive glucose metabolism. Hence: the astroglia, not necessarily the neurons, are proposed to be the type of cells in which the disease resides. Most probably depressive disorder is a multitude of diseases, explaining the apparent multitude of symptoms, and the fact that different patients do respond to different drugs. Therefore: one can only formulate the hypothesis by mentioning a common denominator to these specific malfunctions, namely: disturbed glucose metabolism in the depressed brain. The present paper reviews several findings and proposes that attenuated cerebral glucose metabolism in frontal parts of the brain, in the astroglia, is the cause of depressive disorder.
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26
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Abbott NJ, Rönnbäck L, Hansson E. Astrocyte-endothelial interactions at the blood-brain barrier. Nat Rev Neurosci 2006; 7:41-53. [PMID: 16371949 DOI: 10.1038/nrn1824] [Citation(s) in RCA: 3637] [Impact Index Per Article: 202.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The blood-brain barrier, which is formed by the endothelial cells that line cerebral microvessels, has an important role in maintaining a precisely regulated microenvironment for reliable neuronal signalling. At present, there is great interest in the association of brain microvessels, astrocytes and neurons to form functional 'neurovascular units', and recent studies have highlighted the importance of brain endothelial cells in this modular organization. Here, we explore specific interactions between the brain endothelium, astrocytes and neurons that may regulate blood-brain barrier function. An understanding of how these interactions are disturbed in pathological conditions could lead to the development of new protective and restorative therapies.
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Affiliation(s)
- N Joan Abbott
- Wolfson Centre for Age-Related Diseases, King's College London, UK.
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27
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Roux F, Couraud PO. Rat brain endothelial cell lines for the study of blood-brain barrier permeability and transport functions. Cell Mol Neurobiol 2005; 25:41-58. [PMID: 15962508 DOI: 10.1007/s10571-004-1376-9] [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] [Indexed: 10/25/2022]
Abstract
(1) In vitro models of the BBB have been developed from cocultures between bovine, porcine, rodent or human brain capillary endothelial cells with rodent or human astrocytes. Since most in vivo BBB studies have been performed with small laboratory animals, especially rats, it is important to establish a rat brain endothelial (RBE) cell culture system that will allow correlations between in vitro and in vivo results. The present review will constitute a brief description of the best characterized RBE cell lines (RBE4, GP8/3.9, GPNT, RBEC1, TR-BBBs and rBCEC4 cell lines) and will summarize their recent and important contribution to our current knowledge of the BBB transport functions and permeability to blood-borne solutes, drugs, and cells. (2) In most cases, primary cultures of RBE cells were transduced with an immortalizing gene (SV40 or polyoma virus large T-antigen or adenovirus E1A), either by transfection of plasmid DNA or by infection using retroviral vectors. In one case however, the conditionally immortalized TR-BBB cell line was derived from primary cultures of brain endothelial cells of SV40-T-expressing transgenic rats. (3) All cell lines appear to have an endothelial morphology. The absence of foci formation would mean that the cells are not transformed. The endothelial origin is shown by the expression of Factor VIII-related antigen. Immortalized RBE cells express all the enzymes and transporters that are considered as specific for the blood-brain barrier endothelium, with similar characteristics to those expected from in vivo analyses, but at a significantly lower level. Some RBE cell lines are responsive to astroglial factors, such as RBE4 cells, rBEC4, and TR-BBB cells. None of the immortalized RBE cell lines appear to generate the necessary restrictive paracellular barrier properties that would allow to use them in transendothelial permeability screening. (4) RBE cell lines have been used to demonstrate that transporters such as organic cation transporter/carnitine transporter, serotonin transporter, and the ATA2 system A isoform are expressed in rat brain endothelium. When the transporter is shown to be expressed with the same properties in the immortalized RBE cells as in vivo, regulation studies may be initiated even if the transporter is down-regulated. Pharmacological applications have been proposed with well-characterized transporters such as monocarboxylic acid transporter-1, large neutral amino acid tansporter-1, nucleoside carrier systems, and P-glycoprotein. RBE cell monolayers have also been used to investigate the mechanism of the transendothelial transport of large molecules, such as immunoliposomes or nanoparticles, potentially useful as drug delivery vectors to the brain. (5) RBE4 and GP8 cell lines have been extensively used to demonstrate that intercellular adhesion molecule-1 (ICAM-1) engagement in brain endothelial cells triggers multiple signal transduction pathways. Using functional assays, it was established that ICAM-1 signaling is intimately and actively involved in facilitating lymphocyte infiltration. (6) Several RBE cell lines have been described, which constitute tentative in vitro models of the rat BBB. The major limitation of these models generally appears to be due to their relatively high paracellular permeability to small molecules, thus limiting their use for permeability studies. The strategies developed for the production of these RBE cell lines will enable the characterization of still more efficient permeability models, as well as the immortalization of human brain endothelial cells.
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Perrière N, Demeuse P, Garcia E, Regina A, Debray M, Andreux JP, Couvreur P, Scherrmann JM, Temsamani J, Couraud PO, Deli MA, Roux F. Puromycin-based purification of rat brain capillary endothelial cell cultures. Effect on the expression of blood-brain barrier-specific properties. J Neurochem 2005; 93:279-89. [PMID: 15816851 DOI: 10.1111/j.1471-4159.2004.03020.x] [Citation(s) in RCA: 241] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
One of the main difficulties with primary rat brain endothelial cell (RBEC) cultures is obtaining pure cultures. The variation in purity limits the achievement of in vitro models of the rat blood-brain barrier. As P-glycoprotein expression is known to be much higher in RBECs than in any contaminating cells, we have tested the effect of five P-glycoprotein substrates (vincristine, vinblastine, colchicine, puromycin and doxorubicin) on RBEC cultures, assuming that RBECs would resist the treatment with these toxic compounds whereas contaminating cells would not. Treatment with either 4 microg/mL puromycin for the first 2 days of culture or 3 microg/mL puromycin for the first 3 days showed the best results without causing toxicity to the cells. Transendothelial electrical resistance was significantly increased in cell monolayers treated with puromycin compared with untreated cell monolayers. When cocultured with astrocytes in the presence of cAMP, the puromycin-treated RBEC monolayer showed a highly reduced permeability to sodium fluorescein (down to 0.75 x 10(-6) cm/s) and a high electrical resistance (up to 500 Omega x cm(2)). In conclusion, this method of RBEC purification will allow the production of in vitro models of the rat blood-brain barrier for cellular and molecular biology studies as well as pharmacological investigations.
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Affiliation(s)
- N Perrière
- CNRS UMR 7157, INSERM U705, University Paris 7, University Paris 5, Hôpital Fernand Widal, Paris, France
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Qutub AA, Hunt CA. Glucose transport to the brain: a systems model. ACTA ACUST UNITED AC 2005; 49:595-617. [PMID: 16269321 DOI: 10.1016/j.brainresrev.2005.03.002] [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: 08/24/2004] [Revised: 03/02/2005] [Accepted: 03/09/2005] [Indexed: 02/07/2023]
Abstract
Glucose transport to the brain involves sophisticated interactions of solutes, transporters, enzymes, and cell signaling processes, within an intricate spatial architecture. The dynamics of the transport are influenced by the adaptive nature of the blood-brain barrier (BBB), the semi-impermeable membranes of brain capillaries. As both the gate and the gatekeeper between blood-borne nutrients and brain tissue, the BBB helps govern brain homeostasis. Glucose in the blood must cross the BBB's luminal and abluminal membranes to reach neural tissue. A robust representation of the glucose transport mechanism can highlight a target for brain therapeutic intervention, help characterize mechanisms behind several disease phenotypes, or suggest a new delivery route for drugs. The challenge for researchers is understanding the relationships between influential physiological variables in vivo, and using that knowledge to predict how alterations or interventions affect glucose transport. This paper reviews factors influencing glucose transport and approaches to representing blood-to-brain glucose transport including in vitro, in vivo, and kinetic models. Applications for different models are highlighted, while their limitations in answering arising questions about the human in vivo BBB lead to a discussion of an alternate approach. A developing complex systems simulation is introduced, initiating a single platform to represent the dynamics of glucose transport across the adapting human blood-brain barrier.
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Affiliation(s)
- Amina A Qutub
- Joint Graduate Group in Bioengineering, University of California, Berkeley and San Francisco, USA.
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Zovein A, Flowers-Ziegler J, Thamotharan S, Shin D, Sankar R, Nguyen K, Gambhir S, Devaskar SU. Postnatal hypoxic-ischemic brain injury alters mechanisms mediating neuronal glucose transport. Am J Physiol Regul Integr Comp Physiol 2004; 286:R273-82. [PMID: 14525722 DOI: 10.1152/ajpregu.00160.2003] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We examined the effect of hypoxic ischemia and hypoxia vs. normoxia on postnatal murine brain substrate transporter concentrations and function. We detected a transient increase in the neuronal brain glucose transporter isoform (GLUT-3) in response to hypoxic ischemia after 4 h of reoxygenation. This increase was associated with no change in GLUT-1 (blood-brain barrier/glial isoform), monocarboxylate transporter isoforms 1 and 2, synapsin I (neuronal marker), or Bax (proapoptotic protein) but with a modest increase in Bcl-2 (antiapoptotic mitochondrial protein) protein concentrations. At 24 h of reoxygenation, the increase in GLUT-3 disappeared but was associated with a decline in Bcl-2 protein concentrations and the Bcl2:Bax ratio, an increase in caspase-3 enzyme activity (apoptotic effector enzyme), and extensive DNA fragmentation, which persisted later in time (48 h) only in the hippocampus. Hypoxia alone in the absence of ischemia was associated with a transient but modest increase in GLUT-3 and synapsin I protein concentrations, which did not cause significant apoptosis and/or necrosis. Assessment of glucose transporter function by 2-deoxyglucose (2-DG) uptake using two distinct techniques, namely positron emission tomography (PET) and the modified Sokoloff method, revealed a discrepancy due to glucose uptake by extracranial Harderian glands that masked the accurate detection of intracranial brain glucose uptake by PET scanning. The modified Sokoloff method assessing 2-DG uptake revealed that the transient increase in GLUT-3 was critical in protecting against a decline in brain glucose uptake. We conclude that hypoxic-ischemic brain injury is associated with transient compensatory changes targeted at protecting glucose delivery to fuel cellular energy metabolism, which then may delay the processes of apoptosis and cell necrosis.
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Affiliation(s)
- Ann Zovein
- Division of Neonatology and Developmental Biology, Department of Pediatrics, David Geffen School of Medicine, Los Angeles, CA, USA
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