1
|
Xue S, Zhou X, Yang ZH, Si XK, Sun X. Stroke-induced damage on the blood-brain barrier. Front Neurol 2023; 14:1248970. [PMID: 37840921 PMCID: PMC10569696 DOI: 10.3389/fneur.2023.1248970] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2023] [Accepted: 08/08/2023] [Indexed: 10/17/2023] Open
Abstract
The blood-brain barrier (BBB) is a functional phenotype exhibited by the neurovascular unit (NVU). It is maintained and regulated by the interaction between cellular and non-cellular matrix components of the NVU. The BBB plays a vital role in maintaining the dynamic stability of the intracerebral microenvironment as a barrier layer at the critical interface between the blood and neural tissues. The large contact area (approximately 20 m2/1.3 kg brain) and short diffusion distance between neurons and capillaries allow endothelial cells to dominate the regulatory role. The NVU is a structural component of the BBB. Individual cells and components of the NVU work together to maintain BBB stability. One of the hallmarks of acute ischemic stroke is the disruption of the BBB, including impaired function of the tight junction and other molecules, as well as increased BBB permeability, leading to brain edema and a range of clinical symptoms. This review summarizes the cellular composition of the BBB and describes the protein composition of the barrier functional junction complex and the mechanisms regulating acute ischemic stroke-induced BBB disruption.
Collapse
Affiliation(s)
| | | | | | | | - Xin Sun
- Stroke Center, Department of Neurology, The First Hospital of Jilin University, Changchun, China
| |
Collapse
|
2
|
Aragón-González A, Shaw PJ, Ferraiuolo L. Blood-Brain Barrier Disruption and Its Involvement in Neurodevelopmental and Neurodegenerative Disorders. Int J Mol Sci 2022; 23:ijms232315271. [PMID: 36499600 PMCID: PMC9737531 DOI: 10.3390/ijms232315271] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2022] [Revised: 11/28/2022] [Accepted: 11/30/2022] [Indexed: 12/12/2022] Open
Abstract
The blood-brain barrier (BBB) is a highly specialized and dynamic compartment which regulates the uptake of molecules and solutes from the blood. The relevance of the maintenance of a healthy BBB underpinning disease prevention as well as the main pathomechanisms affecting BBB function will be detailed in this review. Barrier disruption is a common aspect in both neurodegenerative diseases, such as amyotrophic lateral sclerosis, and neurodevelopmental diseases, including autism spectrum disorders. Throughout this review, conditions altering the BBB during the earliest and latest stages of life will be discussed, revealing common factors involved. Due to the barrier's role in protecting the brain from exogenous components and xenobiotics, drug delivery across the BBB is challenging. Potential therapies based on the BBB properties as molecular Trojan horses, among others, will be reviewed, as well as innovative treatments such as stem cell therapies. Additionally, due to the microbiome influence on the normal function of the brain, microflora modulation strategies will be discussed. Finally, future research directions are highlighted to address the current gaps in the literature, emphasizing the idea that common therapies for both neurodevelopmental and neurodegenerative pathologies exist.
Collapse
Affiliation(s)
- Ana Aragón-González
- Sheffield Institute for Translational Neuroscience, University of Sheffield, SITraN, 385a Glossop Road, Sheffield S10 2HQ, UK
- Facultad de Medicina, Universidad de Málaga, 29010 Málaga, Spain
| | - Pamela J. Shaw
- Sheffield Institute for Translational Neuroscience, University of Sheffield, SITraN, 385a Glossop Road, Sheffield S10 2HQ, UK
| | - Laura Ferraiuolo
- Sheffield Institute for Translational Neuroscience, University of Sheffield, SITraN, 385a Glossop Road, Sheffield S10 2HQ, UK
- Correspondence: ; Tel.: +44-(0)114-222-2257; Fax: +44-(0)114-222-2290
| |
Collapse
|
3
|
Gruenbaum BF, Zlotnik A, Fleidervish I, Frenkel A, Boyko M. Glutamate Neurotoxicity and Destruction of the Blood–Brain Barrier: Key Pathways for the Development of Neuropsychiatric Consequences of TBI and Their Potential Treatment Strategies. Int J Mol Sci 2022; 23:ijms23179628. [PMID: 36077024 PMCID: PMC9456007 DOI: 10.3390/ijms23179628] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2022] [Revised: 08/17/2022] [Accepted: 08/22/2022] [Indexed: 11/18/2022] Open
Abstract
Traumatic brain injury (TBI) is associated with significant cognitive and psychiatric conditions. Neuropsychiatric symptoms can persist for years following brain injury, causing major disruptions in patients’ lives. In this review, we examine the role of glutamate as an aftereffect of TBI that contributes to the development of neuropsychiatric conditions. We hypothesize that TBI causes long-term blood–brain barrier (BBB) dysfunction lasting many years and even decades. We propose that dysfunction in the BBB is the central factor that modulates increased glutamate after TBI and ultimately leads to neurodegenerative processes and subsequent manifestation of neuropsychiatric conditions. Here, we have identified factors that determine the upper and lower levels of glutamate concentration in the brain after TBI. Furthermore, we consider treatments of disruptions to BBB integrity, including repairing the BBB and controlling excess glutamate, as potential therapeutic modalities for the treatment of acute and chronic neuropsychiatric conditions and symptoms. By specifically focusing on the BBB, we hypothesize that restoring BBB integrity will alleviate neurotoxicity and related neurological sequelae.
Collapse
Affiliation(s)
- Benjamin F. Gruenbaum
- Department of Anesthesiology and Perioperative Medicine, Mayo Clinic, Jacksonville, FL 32224, USA
| | - Alexander Zlotnik
- Department of Anesthesiology and Critical Care, Soroka University Medical Center, Ben-Gurion of the Negev, Beer-Sheva 84105, Israel
| | - Ilya Fleidervish
- Department of Physiology and Cell Biology, Faculty of Health Sciences and Zlotowski Center for Neuroscience, Ben-Gurion University of the Negev, Beer-Sheva 84105, Israel
| | - Amit Frenkel
- Department of Anesthesiology and Critical Care, Soroka University Medical Center, Ben-Gurion of the Negev, Beer-Sheva 84105, Israel
| | - Matthew Boyko
- Department of Anesthesiology and Critical Care, Soroka University Medical Center, Ben-Gurion of the Negev, Beer-Sheva 84105, Israel
- Correspondence:
| |
Collapse
|
4
|
Elhussiny MZ, Tran PV, Tsuru Y, Haraguchi S, Gilbert ER, Cline MA, Bungo T, Furuse M, Chowdhury VS. Central Taurine Attenuates Hyperthermia and Isolation Stress Behaviors Augmented by Corticotropin-Releasing Factor with Modifying Brain Amino Acid Metabolism in Neonatal Chicks. Metabolites 2022; 12:metabo12010083. [PMID: 35050205 PMCID: PMC8781603 DOI: 10.3390/metabo12010083] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Revised: 01/13/2022] [Accepted: 01/13/2022] [Indexed: 01/01/2023] Open
Abstract
The objective of this study was to determine the effects of centrally administered taurine on rectal temperature, behavioral responses and brain amino acid metabolism under isolation stress and the presence of co-injected corticotropin-releasing factor (CRF). Neonatal chicks were centrally injected with saline, 2.1 pmol of CRF, 2.5 μmol of taurine or both taurine and CRF. The results showed that CRF-induced hyperthermia was attenuated by co-injection with taurine. Taurine, alone or with CRF, significantly decreased the number of distress vocalizations and the time spent in active wakefulness, as well as increased the time spent in the sleeping posture, compared with the saline- and CRF-injected chicks. An amino acid chromatographic analysis revealed that diencephalic leucine, isoleucine, tyrosine, glutamate, asparagine, alanine, β-alanine, cystathionine and 3-methylhistidine were decreased in response to taurine alone or in combination with CRF. Central taurine, alone and when co-administered with CRF, decreased isoleucine, phenylalanine, tyrosine and cysteine, but increased glycine concentrations in the brainstem, compared with saline and CRF groups. The results collectively indicate that central taurine attenuated CRF-induced hyperthermia and stress behaviors in neonatal chicks, and the mechanism likely involves the repartitioning of amino acids to different metabolic pathways. In particular, brain leucine, isoleucine, cysteine, glutamate and glycine may be mobilized to cope with acute stressors.
Collapse
Affiliation(s)
- Mohamed Z. Elhussiny
- Laboratory of Regulation in Metabolism and Behavior, Graduate School of Bioresource and Bioenvironmental Science, Kyushu University, Fukuoka 819-0395, Japan; (M.Z.E.); (P.V.T.); (Y.T.); (M.F.)
- Department of Animal & Poultry Behavior and Management, Faculty of Veterinary Medicine, Aswan University, Aswan 81528, Egypt
| | - Phuong V. Tran
- Laboratory of Regulation in Metabolism and Behavior, Graduate School of Bioresource and Bioenvironmental Science, Kyushu University, Fukuoka 819-0395, Japan; (M.Z.E.); (P.V.T.); (Y.T.); (M.F.)
| | - Yuriko Tsuru
- Laboratory of Regulation in Metabolism and Behavior, Graduate School of Bioresource and Bioenvironmental Science, Kyushu University, Fukuoka 819-0395, Japan; (M.Z.E.); (P.V.T.); (Y.T.); (M.F.)
| | - Shogo Haraguchi
- Department of Biochemistry, Showa University School of Medicine, Tokyo 142-8555, Japan;
| | - Elizabeth R. Gilbert
- School of Neuroscience, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061-0306, USA; (E.R.G.); (M.A.C.)
| | - Mark A. Cline
- School of Neuroscience, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061-0306, USA; (E.R.G.); (M.A.C.)
| | - Takashi Bungo
- Department of Bioresource Science, Graduate School of Biosphere Science, Hiroshima University, Higashi-Hiroshima 739-8528, Japan;
| | - Mitsuhiro Furuse
- Laboratory of Regulation in Metabolism and Behavior, Graduate School of Bioresource and Bioenvironmental Science, Kyushu University, Fukuoka 819-0395, Japan; (M.Z.E.); (P.V.T.); (Y.T.); (M.F.)
| | - Vishwajit S. Chowdhury
- Laboratory of Regulation in Metabolism and Behavior, Graduate School of Bioresource and Bioenvironmental Science, Kyushu University, Fukuoka 819-0395, Japan; (M.Z.E.); (P.V.T.); (Y.T.); (M.F.)
- Division of Experimental Natural Science, Faculty of Arts and Science, Kyushu University, Fukuoka 819-0395, Japan
- Correspondence:
| |
Collapse
|
5
|
Hinca SB, Salcedo C, Wagner A, Goldeman C, Sadat E, Aibar MMD, Maechler P, Brodin B, Aldana BI, Helms HCC. Brain endothelial cells metabolize glutamate via glutamate dehydrogenase to replenish TCA-intermediates and produce ATP under hypoglycemic conditions. J Neurochem 2020; 157:1861-1875. [PMID: 33025588 DOI: 10.1111/jnc.15207] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Revised: 09/29/2020] [Accepted: 10/01/2020] [Indexed: 12/15/2022]
Abstract
The endothelial cells of the blood-brain barrier participate in the regulation of glutamate concentrations in the brain interstitial fluid by taking up brain glutamate. However, endothelial glutamate metabolism has not been characterized, nor is its role in brain glutamate homeostasis and endothelial energy production known. The aim of this study was to investigate endothelial glutamate dehydrogenase (GDH) expression and glutamate metabolism and probe its functional significance. The primary brain endothelial cells were isolated from bovine and mouse brains, and human brain endothelial cells were derived from induced pluripotent stem cells. GDH expression on the protein level and GDH function were investigated in the model systems using western blotting, confocal microscopy, 13 C-glutamate metabolism, and Seahorse assay. In this study, it was shown that GDH was expressed in murine and bovine brain capillaries and in cultured primary mouse and bovine brain endothelial cells as well as in human-induced pluripotent stem cell-derived endothelial cells. The endothelial GDH expression was confirmed in brain capillaries from mice carrying a central nervous system-specific GDH knockout. Endothelial cells from all tested species metabolized 13 C-glutamate to α-ketoglutarate, which subsequently entered the tricarboxylic acid (TCA)-cycle. Brain endothelial cells maintained mitochondrial oxygen consumption rates, when supplied with glutamate alone, whereas glutamate supplied in addition to glucose did not lead to additional oxygen consumption. In conclusion, brain endothelial cells directly take up and metabolize glutamate and utilize the resulting α-ketoglutarate in the tricarboxylic acid cycle to ultimately yield ATP if glucose is unavailable.
Collapse
Affiliation(s)
- Sven B Hinca
- Department of Pharmacy, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Claudia Salcedo
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Antonie Wagner
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Charlotte Goldeman
- Department of Pharmacy, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Edris Sadat
- Department of Pharmacy, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Marco M D Aibar
- Department of Pharmacy, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Pierre Maechler
- Department of Cell Physiology and Metabolism, CMU, University of Geneva, Geneva, Switzerland
| | - Birger Brodin
- Department of Pharmacy, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Blanca I Aldana
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Hans C C Helms
- Department of Pharmacy, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| |
Collapse
|
6
|
Zaragozá R. Transport of Amino Acids Across the Blood-Brain Barrier. Front Physiol 2020; 11:973. [PMID: 33071801 PMCID: PMC7538855 DOI: 10.3389/fphys.2020.00973] [Citation(s) in RCA: 97] [Impact Index Per Article: 19.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Accepted: 07/16/2020] [Indexed: 01/17/2023] Open
Abstract
The blood-brain-barrier (BBB), present in brain capillaries, constitutes an essential barrier mechanism for normal functioning and development of the brain. The presence of tight junctions between adjacent endothelial cells restricts permeability and movement of molecules between extracellular fluid and plasma. The protein complexes that control cell-cell attachment also polarize cellular membrane, so that it can be divided into luminal (blood-facing) and abluminal (brain) sides, and each solute that enters/leaves the brain must cross both membranes. Several amino acid (AA) transport systems with different distributions on both sides of the BBB have been described. In a broad sense, there are at least five different systems of facilitative transporters and all of them are found in the luminal membrane. Some of these transporters are very specific for a small group of substrates and are located exclusively on the luminal side of the BBB. However, the two major facilitative carriers, system L and system y+, are located in both membranes, although asymmetrically. The position of these Na+-independent transporters ensures AA availability in the brain and also its bidirectional transport across the endothelial cells. On the other hand, there are several Na+-dependent transport systems that transport AAs against its concentration gradient together with the movement of Na+ ions. The majority of these active transporters are present exclusively at the abluminal membrane and are responsible for AA efflux from the brain into the endothelial cells. Since they are Na+-coupled, the sodium pump Na+/K+-ATPase is also highly expressed on this abluminal side of the BBB. Once inside the cell, the facilitative transporters located in the luminal membranes mediate export from the endothelial cell to the blood. In summary, the polarized distribution of these transport systems between the luminal and abluminal membranes, and the fact that more than one transporter may carry the same substrate, ensures supply and excretion of AAs in and out of the brain, thereby controlling its homeostasis and proper function.
Collapse
Affiliation(s)
- Rosa Zaragozá
- Department of Human Anatomy and Embriology, School of Medicine, IIS INCLIVA, University of Valencia, Valencia, Spain
| |
Collapse
|
7
|
Oxidative Stress-Mediated Blood-Brain Barrier (BBB) Disruption in Neurological Diseases. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2020. [DOI: 10.1155/2020/4356386] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The blood-brain barrier (BBB), as a crucial gate of brain-blood molecular exchange, is involved in the pathogenesis of multiple neurological diseases. Oxidative stress is caused by an imbalance between the production of reactive oxygen species (ROS) and the scavenger system. Since oxidative stress plays a significant role in the production and maintenance of the BBB, the cerebrovascular system is especially vulnerable to it. The pathways that initiate BBB dysfunction include, but are not limited to, mitochondrial dysfunction, excitotoxicity, iron metabolism, cytokines, pyroptosis, and necroptosis, all converging on the generation of ROS. Interestingly, ROS also provide common triggers that directly regulate BBB damage, parameters including tight junction (TJ) modifications, transporters, matrix metalloproteinase (MMP) activation, inflammatory responses, and autophagy. We will discuss the role of oxidative stress-mediated BBB disruption in neurological diseases, such as hemorrhagic stroke, ischemic stroke (IS), Alzheimer’s disease (AD), Parkinson’s disease (PD), traumatic brain injury (TBI), amyotrophic lateral sclerosis (ALS), and cerebral small vessel disease (CSVD). This review will also discuss the latest clinical evidence of potential biomarkers and antioxidant drugs towards oxidative stress in neurological diseases. A deeper understanding of how oxidative stress damages BBB may open up more therapeutic options for the treatment of neurological diseases.
Collapse
|
8
|
Jung WY, Kim SG, Kim HK, Huh SY, Kim DW, Yoon DU, Yang CH, Kim HY, Jang EY. The Effect of Oral Administration of Black Sticky Rice with Giant Embryo on Brain GABA Concentrations. Psychiatry Investig 2019; 16:615-620. [PMID: 31352770 PMCID: PMC6710419 DOI: 10.30773/pi.2019.05.13.2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/27/2019] [Accepted: 05/13/2019] [Indexed: 12/05/2022] Open
Abstract
OBJECTIVE Black sticky rice with giant embryo (BSRGE) contains high GABA content and affects alcohol-related indices among social drinkers, and alcohol intake and anxiety-related behavior of mice. However, it is unknown whether the intake of BSRGE affects GABAergic activity of brain directly. The purpose of this study is to elucidate the effect of oral administration of BSRGE on brain GABA concentrations compared with commercially available GABA compound and regular feeds. METHODS Twenty-one male C57BL/6 mice were assigned to BSRGE, a regular feed (AIN-76) lacking GABA, and a regular feed containing GABA compound. After feeding freely for 48 h, the cortex and striatum were separated from the brain. An enzyme-linked immunosorbent assay was conducted to measure GABA and glutamate concentrations in mouse brain. RESULTS The GABA concentration of the BSRGE group was higher than that of regular feed and GABA compound group (p<0.001). However, the GABA compound group showed no significant difference from the regular feed group (p=0.50). CONCLUSION Intake of BSRGE containing high GABA content increased GABA concentrations in mouse brain compared with regular feed unlike GABA compound. The results of this study constitute an important basis for further investigations into the clinical applications of BSRGE.
Collapse
Affiliation(s)
- Woo-Young Jung
- Department of Psychiatry, Pusan National University Yangsan Hospital, Yangsan, Republic of Korea
| | - Sung-Gon Kim
- Department of Psychiatry, Pusan National University Yangsan Hospital, Yangsan, Republic of Korea.,Department of Psychiatry, Pusan National University School of Medicine, Yangsan, Republic of Korea
| | - Hyeon-Kyeong Kim
- Medical Research Institute, Pusan National University, Busan, Republic of Korea
| | - Sung-Young Huh
- Department of Psychiatry, Pusan National University Yangsan Hospital, Yangsan, Republic of Korea
| | - Dae-Wook Kim
- Department of Psychiatry, Pusan National University Yangsan Hospital, Yangsan, Republic of Korea
| | - Dong-Uk Yoon
- Department of Psychiatry, Pusan National University Yangsan Hospital, Yangsan, Republic of Korea
| | - Chae Ha Yang
- Department of Physiology, College of Korean Medicine, Daegu Haany University, Daegu, Republic of Korea
| | - Hee Young Kim
- Department of Physiology, College of Korean Medicine, Daegu Haany University, Daegu, Republic of Korea
| | - Eun Young Jang
- Department of Physiology, College of Korean Medicine, Daegu Haany University, Daegu, Republic of Korea.,Research Center for Convergence Toxicology, Korea Institute of Toxicology, Daegeon, Republic of Korea
| |
Collapse
|
9
|
Hladky SB, Barrand MA. Elimination of substances from the brain parenchyma: efflux via perivascular pathways and via the blood-brain barrier. Fluids Barriers CNS 2018; 15:30. [PMID: 30340614 PMCID: PMC6194691 DOI: 10.1186/s12987-018-0113-6] [Citation(s) in RCA: 133] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2018] [Accepted: 08/30/2018] [Indexed: 02/06/2023] Open
Abstract
This review considers efflux of substances from brain parenchyma quantified as values of clearances (CL, stated in µL g-1 min-1). Total clearance of a substance is the sum of clearance values for all available routes including perivascular pathways and the blood-brain barrier. Perivascular efflux contributes to the clearance of all water-soluble substances. Substances leaving via the perivascular routes may enter cerebrospinal fluid (CSF) or lymph. These routes are also involved in entry to the parenchyma from CSF. However, evidence demonstrating net fluid flow inwards along arteries and then outwards along veins (the glymphatic hypothesis) is still lacking. CLperivascular, that via perivascular routes, has been measured by following the fate of exogenously applied labelled tracer amounts of sucrose, inulin or serum albumin, which are not metabolized or eliminated across the blood-brain barrier. With these substances values of total CL ≅ 1 have been measured. Substances that are eliminated at least partly by other routes, i.e. across the blood-brain barrier, have higher total CL values. Substances crossing the blood-brain barrier may do so by passive, non-specific means with CLblood-brain barrier values ranging from < 0.01 for inulin to > 1000 for water and CO2. CLblood-brain barrier values for many small solutes are predictable from their oil/water partition and molecular weight. Transporters specific for glucose, lactate and many polar substrates facilitate efflux across the blood-brain barrier producing CLblood-brain barrier values > 50. The principal route for movement of Na+ and Cl- ions across the blood-brain barrier is probably paracellular through tight junctions between the brain endothelial cells producing CLblood-brain barrier values ~ 1. There are large fluxes of amino acids into and out of the brain across the blood-brain barrier but only small net fluxes have been observed suggesting substantial reuse of essential amino acids and α-ketoacids within the brain. Amyloid-β efflux, which is measurably faster than efflux of inulin, is primarily across the blood-brain barrier. Amyloid-β also leaves the brain parenchyma via perivascular efflux and this may be important as the route by which amyloid-β reaches arterial walls resulting in cerebral amyloid angiopathy.
Collapse
Affiliation(s)
- Stephen B. Hladky
- Department of Pharmacology, University of Cambridge, Cambridge, CB2 1PD UK
| | - Margery A. Barrand
- Department of Pharmacology, University of Cambridge, Cambridge, CB2 1PD UK
| |
Collapse
|
10
|
Zhang D, Mably AJ, Walsh DM, Rowan MJ. Peripheral Interventions Enhancing Brain Glutamate Homeostasis Relieve Amyloid β- and TNFα- Mediated Synaptic Plasticity Disruption in the Rat Hippocampus. Cereb Cortex 2018; 27:3724-3735. [PMID: 27390019 DOI: 10.1093/cercor/bhw193] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Dysregulation of glutamate homeostasis in the interstitial fluid of the brain is strongly implicated in causing synaptic dysfunction in many neurological and psychiatric illnesses. In the case of Alzheimer's disease (AD), amyloid β (Aβ)-mediated disruption of synaptic plasticity and memory can be alleviated by interventions that directly remove glutamate or block certain glutamate receptors. An alternative strategy is to facilitate the removal of excess glutamate from the nervous system by activating peripheral glutamate clearance systems. One such blood-based system, glutamate oxaloacetate transaminase (GOT), is activated by oxaloacetate, which acts as a co-substrate. We report here that synthetic and AD brain-derived Aβ-mediated inhibition of synaptic long-term potentiation in the hippocampus is alleviated by oxaloacetate. Moreover the effect of oxaloacetate was GOT-dependent. The disruptive effects of a general inhibitor of excitatory amino acid transport or TNFα, a pro-inflammatory mediator of Aβ action, were also reversed by oxaloacetate. Furthermore, another intervention that increases peripheral glutamate clearance, peritoneal dialysis, mimicked the beneficial effect of oxaloacetate. These findings lend support to the promotion of the peripheral clearance of glutamate as a means to alleviate synaptic dysfunction that is caused by impaired glutamate homeostasis in the brain.
Collapse
Affiliation(s)
- Dainan Zhang
- Department of Pharmacology and Therapeutics, and Trinity College Institute of Neuroscience, Trinity College, Dublin 2, Ireland
| | - Alexandra J Mably
- Laboratory for Neurodegenerative Research, Ann Romney Center for Neurologic Diseases, Brigham & Women's Hospital, Harvard Institute of Medicine, 77 Avenue Louis Pasteur, Boston, MA 02115, USA
| | - Dominic M Walsh
- Laboratory for Neurodegenerative Research, Ann Romney Center for Neurologic Diseases, Brigham & Women's Hospital, Harvard Institute of Medicine, 77 Avenue Louis Pasteur, Boston, MA 02115, USA
| | - Michael J Rowan
- Department of Pharmacology and Therapeutics, and Trinity College Institute of Neuroscience, Trinity College, Dublin 2, Ireland
| |
Collapse
|
11
|
Bai W, Zhou YG. Homeostasis of the Intraparenchymal-Blood Glutamate Concentration Gradient: Maintenance, Imbalance, and Regulation. Front Mol Neurosci 2017; 10:400. [PMID: 29259540 PMCID: PMC5723322 DOI: 10.3389/fnmol.2017.00400] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2017] [Accepted: 11/20/2017] [Indexed: 12/25/2022] Open
Abstract
It is widely accepted that glutamate is the most important excitatory neurotransmitter in the central nervous system (CNS). However, there is also a large amount of glutamate in the blood. Generally, the concentration gradient of glutamate between intraparenchymal and blood environments is stable. However, this gradient is dramatically disrupted under a variety of pathological conditions, resulting in an amplifying cascade that causes a series of pathological reactions in the CNS and peripheral organs. This eventually seriously worsens a patient’s prognosis. These two “isolated” systems are rarely considered as a whole even though they mutually influence each other. In this review, we summarize what is currently known regarding the maintenance, imbalance and regulatory mechanisms that control the intraparenchymal-blood glutamate concentration gradient, discuss the interrelationships between these systems and further explore their significance in clinical practice.
Collapse
Affiliation(s)
- Wei Bai
- Molecular Biology Center, State Key Laboratory of Trauma, Burn, and Combined Injury, Research Institute of Surgery and Daping Hospital, Third Military Medical University, Chongqing, China
| | - Yuan-Guo Zhou
- Molecular Biology Center, State Key Laboratory of Trauma, Burn, and Combined Injury, Research Institute of Surgery and Daping Hospital, Third Military Medical University, Chongqing, China
| |
Collapse
|
12
|
Helms HC, Aldana BI, Groth S, Jensen MM, Waagepetersen HS, Nielsen CU, Brodin B. Characterization of the L-glutamate clearance pathways across the blood-brain barrier and the effect of astrocytes in an in vitro blood-brain barrier model. J Cereb Blood Flow Metab 2017; 37:3744-3758. [PMID: 28145808 PMCID: PMC5718321 DOI: 10.1177/0271678x17690760] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The aim was to characterize the clearance pathways for L-glutamate from the brain interstitial fluid across the blood-brain barrier using a primary in vitro bovine endothelial/rat astrocyte co-culture. Transporter profiling was performed using uptake studies of radiolabeled L-glutamate with co-application of transporter inhibitors and competing amino acids. Endothelial abluminal L-glutamate uptake was almost abolished by co-application of an EAAT-1 specific inhibitor, whereas luminal uptake was inhibited by L-glutamate and L-aspartate (1 mM). L-glutamate uptake followed Michaelis-Menten-like kinetics with high and low affinity at the abluminal and luminal membrane, respectively. This indicated that L-glutamate is taken up via EAAT-1 at the abluminal membrane and exits at the luminal membrane via a low affinity glutamate/aspartate transporter. Metabolism of L-glutamate and transport of metabolites was examined using [U-13C] L-glutamate. Intact L-glutamate and metabolites derived from oxidative metabolism were transported through the endothelial cells. High amounts of L-glutamate-derived lactate in the luminal medium indicated cataplerosis via malic enzyme. Thus, L-glutamate can be transported intact from brain to blood via the concerted action of abluminal and luminal transport proteins, but the total brain clearance is highly dependent on metabolism in astrocytes and endothelial cells followed by transport of metabolites.
Collapse
Affiliation(s)
- Hans Cc Helms
- 1 Department of Pharmacy, The Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Blanca I Aldana
- 2 Department of Drug Design and Pharmacology, The Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Simon Groth
- 1 Department of Pharmacy, The Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Morten M Jensen
- 1 Department of Pharmacy, The Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Helle S Waagepetersen
- 2 Department of Drug Design and Pharmacology, The Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Carsten U Nielsen
- 1 Department of Pharmacy, The Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.,3 Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, Odense M, Denmark
| | - Birger Brodin
- 1 Department of Pharmacy, The Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| |
Collapse
|
13
|
Jiang X, Andjelkovic AV, Zhu L, Yang T, Bennett MVL, Chen J, Keep RF, Shi Y. Blood-brain barrier dysfunction and recovery after ischemic stroke. Prog Neurobiol 2017; 163-164:144-171. [PMID: 28987927 DOI: 10.1016/j.pneurobio.2017.10.001] [Citation(s) in RCA: 599] [Impact Index Per Article: 74.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2016] [Revised: 05/30/2017] [Accepted: 10/02/2017] [Indexed: 01/06/2023]
Abstract
The blood-brain barrier (BBB) plays a vital role in regulating the trafficking of fluid, solutes and cells at the blood-brain interface and maintaining the homeostatic microenvironment of the CNS. Under pathological conditions, such as ischemic stroke, the BBB can be disrupted, followed by the extravasation of blood components into the brain and compromise of normal neuronal function. This article reviews recent advances in our knowledge of the mechanisms underlying BBB dysfunction and recovery after ischemic stroke. CNS cells in the neurovascular unit, as well as blood-borne peripheral cells constantly modulate the BBB and influence its breakdown and repair after ischemic stroke. The involvement of stroke risk factors and comorbid conditions further complicate the pathogenesis of neurovascular injury by predisposing the BBB to anatomical and functional changes that can exacerbate BBB dysfunction. Emphasis is also given to the process of long-term structural and functional restoration of the BBB after ischemic injury. With the development of novel research tools, future research on the BBB is likely to reveal promising potential therapeutic targets for protecting the BBB and improving patient outcome after ischemic stroke.
Collapse
Affiliation(s)
- Xiaoyan Jiang
- Pittsburgh Institute of Brain Disorders & Recovery and Department of Neurology, University of Pittsburgh, Pittsburgh, PA 15213, USA; State Key Laboratory of Medical Neurobiology, Institute of Brain Sciences and Collaborative Innovation Center for Brain Science, Fudan University, Shanghai 200032, China
| | | | - Ling Zhu
- Pittsburgh Institute of Brain Disorders & Recovery and Department of Neurology, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Tuo Yang
- Pittsburgh Institute of Brain Disorders & Recovery and Department of Neurology, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Michael V L Bennett
- State Key Laboratory of Medical Neurobiology, Institute of Brain Sciences and Collaborative Innovation Center for Brain Science, Fudan University, Shanghai 200032, China; Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Jun Chen
- Pittsburgh Institute of Brain Disorders & Recovery and Department of Neurology, University of Pittsburgh, Pittsburgh, PA 15213, USA; State Key Laboratory of Medical Neurobiology, Institute of Brain Sciences and Collaborative Innovation Center for Brain Science, Fudan University, Shanghai 200032, China
| | - Richard F Keep
- Department of Neurosurgery, University of Michigan, Ann Arbor, MI 48109, USA.
| | - Yejie Shi
- Pittsburgh Institute of Brain Disorders & Recovery and Department of Neurology, University of Pittsburgh, Pittsburgh, PA 15213, USA.
| |
Collapse
|
14
|
Saidijam M, Karimi Dermani F, Sohrabi S, Patching SG. Efflux proteins at the blood-brain barrier: review and bioinformatics analysis. Xenobiotica 2017; 48:506-532. [PMID: 28481715 DOI: 10.1080/00498254.2017.1328148] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
1. Efflux proteins at the blood-brain barrier provide a mechanism for export of waste products of normal metabolism from the brain and help to maintain brain homeostasis. They also prevent entry into the brain of a wide range of potentially harmful compounds such as drugs and xenobiotics. 2. Conversely, efflux proteins also hinder delivery of therapeutic drugs to the brain and central nervous system used to treat brain tumours and neurological disorders. For bypassing efflux proteins, a comprehensive understanding of their structures, functions and molecular mechanisms is necessary, along with new strategies and technologies for delivery of drugs across the blood-brain barrier. 3. We review efflux proteins at the blood-brain barrier, classified as either ATP-binding cassette (ABC) transporters (P-gp, BCRP, MRPs) or solute carrier (SLC) transporters (OATP1A2, OATP1A4, OATP1C1, OATP2B1, OAT3, EAATs, PMAT/hENT4 and MATE1). 4. This includes information about substrate and inhibitor specificity, structural organisation and mechanism, membrane localisation, regulation of expression and activity, effects of diseases and conditions and the principal technique used for in vivo analysis of efflux protein activity: positron emission tomography (PET). 5. We also performed analyses of evolutionary relationships, membrane topologies and amino acid compositions of the proteins, and linked these to structure and function.
Collapse
Affiliation(s)
- Massoud Saidijam
- a Department of Molecular Medicine and Genetics , Research Centre for Molecular Medicine, School of Medicine, Hamadan University of Medical Sciences , Hamadan , Iran and
| | - Fatemeh Karimi Dermani
- a Department of Molecular Medicine and Genetics , Research Centre for Molecular Medicine, School of Medicine, Hamadan University of Medical Sciences , Hamadan , Iran and
| | - Sareh Sohrabi
- a Department of Molecular Medicine and Genetics , Research Centre for Molecular Medicine, School of Medicine, Hamadan University of Medical Sciences , Hamadan , Iran and
| | - Simon G Patching
- b School of BioMedical Sciences and the Astbury Centre for Structural Molecular Biology, University of Leeds , Leeds , UK
| |
Collapse
|
15
|
Weiler A, Volkenhoff A, Hertenstein H, Schirmeier S. Metabolite transport across the mammalian and insect brain diffusion barriers. Neurobiol Dis 2017; 107:15-31. [PMID: 28237316 DOI: 10.1016/j.nbd.2017.02.008] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2016] [Revised: 01/02/2017] [Accepted: 02/20/2017] [Indexed: 12/31/2022] Open
Abstract
The nervous system in higher vertebrates is separated from the circulation by a layer of specialized endothelial cells. It protects the sensitive neurons from harmful blood-derived substances, high and fluctuating ion concentrations, xenobiotics or even pathogens. To this end, the brain endothelial cells and their interlinking tight junctions build an efficient diffusion barrier. A structurally analogous diffusion barrier exists in insects, where glial cell layers separate the hemolymph from the neural cells. Both types of diffusion barriers, of course, also prevent influx of metabolites from the circulation. Because neuronal function consumes vast amounts of energy and necessitates influx of diverse substrates and metabolites, tightly regulated transport systems must ensure a constant metabolite supply. Here, we review the current knowledge about transport systems that carry key metabolites, amino acids, lipids and carbohydrates into the vertebrate and Drosophila brain and how this transport is regulated. Blood-brain and hemolymph-brain transport functions are conserved and we can thus use a simple, genetically accessible model system to learn more about features and dynamics of metabolite transport into the brain.
Collapse
Affiliation(s)
- Astrid Weiler
- Institut für Neuro- und Verhaltensbiologie, Universität Münster, Badestr. 9, 48149 Münster, Germany
| | - Anne Volkenhoff
- Institut für Neuro- und Verhaltensbiologie, Universität Münster, Badestr. 9, 48149 Münster, Germany
| | - Helen Hertenstein
- Institut für Neuro- und Verhaltensbiologie, Universität Münster, Badestr. 9, 48149 Münster, Germany
| | - Stefanie Schirmeier
- Institut für Neuro- und Verhaltensbiologie, Universität Münster, Badestr. 9, 48149 Münster, Germany.
| |
Collapse
|
16
|
Erdő F, Denes L, de Lange E. Age-associated physiological and pathological changes at the blood-brain barrier: A review. J Cereb Blood Flow Metab 2017; 37:4-24. [PMID: 27837191 PMCID: PMC5363756 DOI: 10.1177/0271678x16679420] [Citation(s) in RCA: 302] [Impact Index Per Article: 37.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/21/2016] [Revised: 10/21/2016] [Accepted: 10/24/2016] [Indexed: 12/13/2022]
Abstract
The age-associated decline of the neurological and cognitive functions becomes more and more serious challenge for the developed countries with the increasing number of aged populations. The morphological and biochemical changes in the aging brain are the subjects of many extended research projects worldwide for a long time. However, the crucial role of the blood-brain barrier (BBB) impairment and disruption in the pathological processes in age-associated neurodegenerative disorders received special attention just for a few years. This article gives an overview on the major elements of the blood-brain barrier and its supporting mechanisms and also on their alterations during development, physiological aging process and age-associated neurodegenerative disorders (Alzheimer's disease, multiple sclerosis, Parkinson's disease, pharmacoresistant epilepsy). Besides the morphological alterations of the cellular elements (endothelial cells, astrocytes, pericytes, microglia, neuronal elements) of the BBB and neurovascular unit, the changes of the barrier at molecular level (tight junction proteins, adheres junction proteins, membrane transporters, basal lamina, extracellular matrix) are also summarized. The recognition of new players and initiators of the process of neurodegeneration at the level of the BBB may offer new avenues for novel therapeutic approaches for the treatment of numerous chronic neurodegenerative disorders currently without effective medication.
Collapse
Affiliation(s)
- Franciska Erdő
- Faculty of Information Technology and Bionics, Pázmány Péter Catholic University, Budapest, Hungary
| | - László Denes
- Institute of Pharmacology & Pharmacotherapy, Semmelweis University, Budapest, Hungary
| | | |
Collapse
|
17
|
|
18
|
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: 4.3] [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]
|
19
|
Sakurai T, Akanuma SI, Usui T, Kubo Y, Tachikawa M, Hosoya KI. Excitatory Amino Acid Transporter 1-Mediated L-Glutamate Transport at the Inner Blood-Retinal Barrier: Possible Role in L-Glutamate Elimination from the Retina. Biol Pharm Bull 2016; 38:1087-91. [PMID: 26133720 DOI: 10.1248/bpb.b15-00226] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The purpose of this study was to elucidate the transport mechanism(s) of L-glutamate (L-Glu), a neuroexcitatory neurotransmitter, in the inner blood-retinal barrier (BRB). The L-Glu transport was evaluated by an in vitro uptake study with a conditionally-immortalized rat retinal capillary endothelial cell line, TR-iBRB2 cells. L-Glu uptake by TR-iBRB2 exhibited time- and concentration-dependence, and was composed of high- and low-affinity processes with Michaelis-Menten constants (Km) of 19.3 µM and 275 µM, respectively. Under Na(+)-free conditions, L-Glu uptake by TR-iBRB2 involved one-saturable kinetics with a Km of 190 µM, which is similar to that of the low-affinity process of L-Glu uptake under normal conditions. Moreover, substrates/inhibitors of system Xc(-), which is involved in blood-to-retina transport of compounds across the inner BRB, strongly inhibited the L-Glu uptake under Na(+)-free conditions, suggesting that Na(+)-independent low-affinity L-Glu transport at the inner BRB is carried out by system Xc(-). Regarding the Na(+)-dependent high affinity process of L-Glu transport at the inner BRB, L-Glu uptake by TR-iBRB2 under normal conditions was significantly inhibited by substrates/inhibitors of excitatory amino acid transporter (EAAT) 1-5, but not alanine-serine-cysteine transporters. Reverse-transcription polymerase chain reaction (RT-PCR) analysis and immunoblot analysis demonstrated that mRNA and protein of EAAT1 are expressed in TR-iBRB2 cells, whereas mRNAs and/or proteins of EAAT2-5 are not. Immunohistochemical analysis revealed that EAAT1 protein is localized on the abluminal membrane of the retinal capillaries. In conclusion, EAAT1 most likely mediates Na(+)-dependent high-affinity L-Glu transport at the inner BRB and appears to take part in L-Glu elimination from the retina across the inner BRB.
Collapse
Affiliation(s)
- Tatsuhiko Sakurai
- Department of Pharmaceutics, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama
| | | | | | | | | | | |
Collapse
|
20
|
Ashby EL, Kierzkowska M, Hull J, Kehoe PG, Hutson SM, Conway ME. Altered Expression of Human Mitochondrial Branched Chain Aminotransferase in Dementia with Lewy Bodies and Vascular Dementia. Neurochem Res 2016; 42:306-319. [PMID: 26980008 PMCID: PMC5283609 DOI: 10.1007/s11064-016-1855-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2015] [Revised: 01/27/2016] [Accepted: 01/28/2016] [Indexed: 11/22/2022]
Abstract
Cytosolic and mitochondrial human branched chain aminotransferase (hBCATc and hBCATm, respectively) play an integral role in brain glutamate metabolism. Regional increased levels of hBCATc in the CA1 and CA4 region of Alzheimer’s disease (AD) brain together with increased levels of hBCATm in frontal and temporal cortex of AD brains, suggest a role for these proteins in glutamate excitotoxicity. Glutamate toxicity is a key pathogenic feature of several neurological disorders including epilepsy associated dementia, AD, vascular dementia (VaD) and dementia with Lewy bodies (DLB). To further understand if these increases are specific to AD, the expression profiles of hBCATc and hBCATm were examined in other forms of dementia including DLB and VaD. Similar to AD, levels of hBCATm were significantly increased in the frontal and temporal cortex of VaD cases and in frontal cortex of DLB cases compared to controls, however there were no observed differences in hBCATc between groups in these areas. Moreover, multiple forms of hBCATm were observed that were particular to the disease state relative to matched controls. Real-time PCR revealed similar expression of hBCATm mRNA in frontal and temporal cortex for all cohort comparisons, whereas hBCATc mRNA expression was significantly increased in VaD cases compared to controls. Collectively our results suggest that hBCATm protein expression is significantly increased in the brains of DLB and VaD cases, similar to those reported in AD brain. These findings indicate a more global response to altered glutamate metabolism and suggest common metabolic responses that might reflect shared neurodegenerative mechanisms across several forms of dementia.
Collapse
Affiliation(s)
- Emma L Ashby
- Department of Applied Science, University of the West of England, Coldharbour Lane, Bristol, BS16 1QY, UK
| | - Marta Kierzkowska
- Department of Applied Science, University of the West of England, Coldharbour Lane, Bristol, BS16 1QY, UK
| | - Jonathon Hull
- Department of Applied Science, University of the West of England, Coldharbour Lane, Bristol, BS16 1QY, UK
| | - Patrick G Kehoe
- Dementia Research Group, Faculty of Medicine and Dentistry, University of Bristol, Bristol, BS16 1LE, UK
| | - Susan M Hutson
- Human Nutrition, Foods, and Exercise, Virginia Tech, 1981 Kraft Drive, 1008 ILSB, Blacksburg, VA, 24060, USA
| | - Myra E Conway
- Department of Applied Science, University of the West of England, Coldharbour Lane, Bristol, BS16 1QY, UK.
| |
Collapse
|
21
|
Castillo J, Loza MI, Mirelman D, Brea J, Blanco M, Sobrino T, Campos F. A novel mechanism of neuroprotection: Blood glutamate grabber. J Cereb Blood Flow Metab 2016; 36:292-301. [PMID: 26661174 PMCID: PMC4759671 DOI: 10.1177/0271678x15606721] [Citation(s) in RCA: 67] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/11/2015] [Accepted: 07/19/2015] [Indexed: 12/22/2022]
Abstract
Glutamate excitotoxicity is a primary contributor of ischemic neuronal death and other cellular components of the neurovascular unit. Several strategies have been developed against glutamate excitotoxicity, however none of them have not shown positive results in the clinical practice so far. Nowadays, the concept of blood/brain glutamate grabbing or scavenging is well recognized as a novel and attractive protective strategy to reduce the excitotoxic effect of excess extracellular glutamate that accumulates in the brain following an ischemic stroke. The main advantage of this novel therapeutic strategy is that it occurs in the blood circulation and therefore does not affect the normal brain neurophysiology, as it has been described for other drug treatments used against glutamate excitotoxicity. In this work we report all experimental data from the beginning of our studies, focused on stroke pathology, and we describe new findings about the potential application of this therapy. Future clinical trials will allow to know the real efficacy of this novel therapeutic strategy in stroke patients.
Collapse
Affiliation(s)
- José Castillo
- Department of Neurology, Clinical University Hospital, Universidade de Santiago de Compostela, Health Research Institute of Santiago de Compostela, Santiago de Compostela, Spain
| | - María Isabel Loza
- Department of Pharmacology, Universidade de Santiago de Compostela, Discovery group BioFarma, Health Research Institute of Santiago de Compostela, Santiago de Compostela, Spain BioFarma Research Group, Centro de Investigación en Medicina Molecular y Enfermedades Crónicas (CIMUS), University of Santiago de Compostela, Santiago de Compostela, Spain
| | - David Mirelman
- Department of Biological Chemistry, Weizmann Institute of Science, Rehovot, Israel
| | - José Brea
- Department of Pharmacology, Universidade de Santiago de Compostela, Discovery group BioFarma, Health Research Institute of Santiago de Compostela, Santiago de Compostela, Spain BioFarma Research Group, Centro de Investigación en Medicina Molecular y Enfermedades Crónicas (CIMUS), University of Santiago de Compostela, Santiago de Compostela, Spain
| | - Miguel Blanco
- Department of Neurology, Clinical University Hospital, Universidade de Santiago de Compostela, Health Research Institute of Santiago de Compostela, Santiago de Compostela, Spain
| | - Tomás Sobrino
- Department of Neurology, Clinical University Hospital, Universidade de Santiago de Compostela, Health Research Institute of Santiago de Compostela, Santiago de Compostela, Spain
| | - Francisco Campos
- Department of Neurology, Clinical University Hospital, Universidade de Santiago de Compostela, Health Research Institute of Santiago de Compostela, Santiago de Compostela, Spain
| |
Collapse
|
22
|
Pérez-Mato M, Iglesias-Deus A, Rujido S, da Silva-Candal A, Sobrino T, Couce ML, Fraga JM, Castillo J, Campos F. Potential protective role of endogenous glutamate-oxaloacetate transaminase against glutamate excitotoxicity in fetal hypoxic-ischaemic asphyxia. Dev Med Child Neurol 2016. [PMID: 26205194 DOI: 10.1111/dmcn.12851] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
AIM Fetal blood contains higher concentrations of glutamate-oxaloacetate transaminase (GOT; a blood enzyme able to metabolize glutamate) than maternal blood. The aim of this study was to determine the relationship between GOT and glutamate levels in arterial blood samples from umbilical cord in control newborn infants and newborn infants with hypoxic-ischaemic insult and/or symptoms of hypoxia-ischemia after delivery. METHOD A total of 46 newborn infants (28 females, 18 males) were prospectively included in the study. Twenty-three infants (18 females, five males) were included as control participants and 23 (10 females, 13 males) were included as newborn infants at risk of adverse neurological outcome (defined as umbilical blood with pH <7.1). RESULTS Analysis of glutamate concentration and GOT activity in umbilical blood samples showed that newborn infants with pH <7.1 had higher levels of glutamate (142.4 μmol/L [SD 61.4] vs 62.8 μmol/L [SD 25.5]; p<0.001) and GOT (83.1 U/L [SD 60.9] vs 34.9 U/L [SD 18.2]; p<0.001) compared to newborn infants without fetal distress. Analysis of Apgar scores and blood pH values (markers of perinatal distress) showed that conditions of severe distress were associated with higher glutamate and GOT levels. INTERPRETATION During fetal development, the ability of GOT to metabolize glutamate suggests that this enzyme can act as an endogenous protective mechanism in the control of glutamate homeostasis.
Collapse
Affiliation(s)
- María Pérez-Mato
- Clinical Neurosciences Research Laboratory, Clinical University Hospital, Health Research Institute of Santiago de Compostela (IDIS), University of Santiago de Compostela, Santiago de Compostela, A Coruña, Spain
| | - Alicia Iglesias-Deus
- Neonatology Unit, Department of Pediatrics, Hospital Clinico Universitario de Santiago, Health Research Institute of Santiago de Compostela (IDIS), Santiago de Compostela, A Coruña, Spain
| | - Susana Rujido
- Neonatology Unit, Department of Pediatrics, Hospital Clinico Universitario de Santiago, Health Research Institute of Santiago de Compostela (IDIS), Santiago de Compostela, A Coruña, Spain
| | - Andrés da Silva-Candal
- Clinical Neurosciences Research Laboratory, Clinical University Hospital, Health Research Institute of Santiago de Compostela (IDIS), University of Santiago de Compostela, Santiago de Compostela, A Coruña, Spain
| | - Tomás Sobrino
- Clinical Neurosciences Research Laboratory, Clinical University Hospital, Health Research Institute of Santiago de Compostela (IDIS), University of Santiago de Compostela, Santiago de Compostela, A Coruña, Spain
| | - María-Luz Couce
- Neonatology Unit, Department of Pediatrics, Hospital Clinico Universitario de Santiago, Health Research Institute of Santiago de Compostela (IDIS), Santiago de Compostela, A Coruña, Spain
| | - José María Fraga
- Neonatology Unit, Department of Pediatrics, Hospital Clinico Universitario de Santiago, Health Research Institute of Santiago de Compostela (IDIS), Santiago de Compostela, A Coruña, Spain
| | - José Castillo
- Clinical Neurosciences Research Laboratory, Clinical University Hospital, Health Research Institute of Santiago de Compostela (IDIS), University of Santiago de Compostela, Santiago de Compostela, A Coruña, Spain
| | - Francisco Campos
- Clinical Neurosciences Research Laboratory, Clinical University Hospital, Health Research Institute of Santiago de Compostela (IDIS), University of Santiago de Compostela, Santiago de Compostela, A Coruña, Spain
| |
Collapse
|
23
|
Chen JT, Chen TG, Chang YC, Chen CY, Chen RM. Roles of NMDARs in maintenance of the mouse cerebrovascular endothelial cell-constructed tight junction barrier. Toxicology 2016; 339:40-50. [DOI: 10.1016/j.tox.2015.11.006] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2015] [Revised: 11/18/2015] [Accepted: 11/28/2015] [Indexed: 10/22/2022]
|
24
|
MRS of brain metabolite levels demonstrates the ability of scavenging of excess brain glutamate to protect against nerve agent induced seizures. Int J Mol Sci 2015; 16:3226-36. [PMID: 25648322 PMCID: PMC4346891 DOI: 10.3390/ijms16023226] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2014] [Accepted: 01/29/2015] [Indexed: 11/16/2022] Open
Abstract
This study describes the use of in vivo magnetic resonance spectrocopy (MRS) to monitor brain glutamate and lactate levels in a paraoxon (PO) intoxication model. Our results show that the administration of recombinant glutamate-oxaloacetate transaminase (rGOT) in combination with oxaloacetate (OxAc) significantly reduces the brain-accumulated levels of glutamate. Previously we have shown that the treatment causes a rapid decrease of blood glutamate levels and creates a gradient between the brain and blood glutamate levels which leads to the efflux of excess brain glutamate into the blood stream thereby reducing its potential to cause neurological damage. The fact that this treatment significantly decreased the brain glutamate and lactate levels following PO intoxication suggests that it could become a new effective neuroprotective agent.
Collapse
|
25
|
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: 10.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2014] [Accepted: 11/24/2014] [Indexed: 12/22/2022]
|