1
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Lazar M, Moroti R, Barbu EC, Chitu-Tisu CE, Tiliscan C, Erculescu TM, Rosca RR, Frasila S, Schmilevschi ET, Simion V, Duca GT, Padiu IF, Andreescu DI, Anton AN, Pacurar CG, Perdun PM, Petre AM, Oprea CA, Popescu AM, Maria E, Ion DA, Olariu MC. The Impact of HIV on Early Brain Aging-A Pathophysiological (Re)View. J Clin Med 2024; 13:7031. [PMID: 39685490 DOI: 10.3390/jcm13237031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2024] [Revised: 11/14/2024] [Accepted: 11/19/2024] [Indexed: 12/18/2024] Open
Abstract
Background/Objectives: This review aims to provide a comprehensive understanding of how HIV alters normal aging trajectories in the brain, presenting the HIV-related molecular mechanisms and pathophysiological pathways involved in brain aging. The review explores the roles of inflammation, oxidative stress, and viral persistence in the brain, highlighting how these factors contribute to neuronal damage and cognitive impairment and accelerate normal brain aging. Additionally, it also addresses the impact of antiretroviral therapy on brain aging and the biological markers associated with its occurrence. Methods: We extensively searched PubMed for English-language articles published from 2000 to 2024. The following keywords were used in the search: "HIV", "brain", "brain aging", "neuroinflammation", "HAART", and "HAND". This strategy yielded 250 articles for inclusion in our review. Results: A combination of blood-brain barrier dysfunction, with the direct effects of HIV on the central nervous system, chronic neuroinflammation, telomere shortening, neurogenesis impairments, and neurotoxicity associated with antiretroviral treatment (ART), alters and amplifies the mechanisms of normal brain aging. Conclusions: Current evidence suggests that HIV infection accelerates neurodegenerative processes of normal brain aging, leading to cognitive decline and structural brain changes at an earlier age than typically observed in the general population.
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Affiliation(s)
- Mihai Lazar
- Faculty of Medicine, University of Medicine and Pharmacy Carol Davila, No. 37, Dionisie Lupu Street, Sector 2, 020021 Bucharest, Romania
- National Institute for Infectious Diseases Prof. Dr. Matei Bals, No. 1, Calistrat Grozovici Street, Sector 2, 021105 Bucharest, Romania
| | - Ruxandra Moroti
- Faculty of Medicine, University of Medicine and Pharmacy Carol Davila, No. 37, Dionisie Lupu Street, Sector 2, 020021 Bucharest, Romania
- National Institute for Infectious Diseases Prof. Dr. Matei Bals, No. 1, Calistrat Grozovici Street, Sector 2, 021105 Bucharest, Romania
| | - Ecaterina Constanta Barbu
- Faculty of Medicine, University of Medicine and Pharmacy Carol Davila, No. 37, Dionisie Lupu Street, Sector 2, 020021 Bucharest, Romania
| | - Cristina Emilia Chitu-Tisu
- Faculty of Medicine, University of Medicine and Pharmacy Carol Davila, No. 37, Dionisie Lupu Street, Sector 2, 020021 Bucharest, Romania
| | - Catalin Tiliscan
- Faculty of Medicine, University of Medicine and Pharmacy Carol Davila, No. 37, Dionisie Lupu Street, Sector 2, 020021 Bucharest, Romania
- Faculty of Dental Medicine, University of Medicine and Pharmacy Carol Davila, No. 37, Dionisie Lupu Street, Sector 2, 020021 Bucharest, Romania
| | - Teodora Maria Erculescu
- Faculty of Medicine, University of Medicine and Pharmacy Carol Davila, No. 37, Dionisie Lupu Street, Sector 2, 020021 Bucharest, Romania
| | - Ruxandra Raluca Rosca
- Faculty of Medicine, University of Medicine and Pharmacy Carol Davila, No. 37, Dionisie Lupu Street, Sector 2, 020021 Bucharest, Romania
| | - Stefan Frasila
- Faculty of Medicine, University of Medicine and Pharmacy Carol Davila, No. 37, Dionisie Lupu Street, Sector 2, 020021 Bucharest, Romania
| | - Emma Teodora Schmilevschi
- Faculty of Medicine, University of Medicine and Pharmacy Carol Davila, No. 37, Dionisie Lupu Street, Sector 2, 020021 Bucharest, Romania
| | - Vladimir Simion
- Faculty of Medicine, University of Medicine and Pharmacy Carol Davila, No. 37, Dionisie Lupu Street, Sector 2, 020021 Bucharest, Romania
| | - George Theodor Duca
- Faculty of Medicine, University of Medicine and Pharmacy Carol Davila, No. 37, Dionisie Lupu Street, Sector 2, 020021 Bucharest, Romania
| | - Isabela Felicia Padiu
- Faculty of Medicine, University of Medicine and Pharmacy Carol Davila, No. 37, Dionisie Lupu Street, Sector 2, 020021 Bucharest, Romania
| | - Darie Ioan Andreescu
- Faculty of Medicine, University of Medicine and Pharmacy Carol Davila, No. 37, Dionisie Lupu Street, Sector 2, 020021 Bucharest, Romania
| | - Andreea Nicoleta Anton
- Faculty of Medicine, University of Medicine and Pharmacy Carol Davila, No. 37, Dionisie Lupu Street, Sector 2, 020021 Bucharest, Romania
| | - Cosmina Georgiana Pacurar
- Faculty of Medicine, University of Medicine and Pharmacy Carol Davila, No. 37, Dionisie Lupu Street, Sector 2, 020021 Bucharest, Romania
| | - Patricia Maria Perdun
- Faculty of Medicine, University of Medicine and Pharmacy Carol Davila, No. 37, Dionisie Lupu Street, Sector 2, 020021 Bucharest, Romania
| | - Alexandru Mihai Petre
- Faculty of Medicine, University of Medicine and Pharmacy Carol Davila, No. 37, Dionisie Lupu Street, Sector 2, 020021 Bucharest, Romania
| | - Constantin Adrian Oprea
- Faculty of Medicine, University of Medicine and Pharmacy Carol Davila, No. 37, Dionisie Lupu Street, Sector 2, 020021 Bucharest, Romania
| | - Adelina Maria Popescu
- Faculty of Medicine, University of Medicine and Pharmacy Carol Davila, No. 37, Dionisie Lupu Street, Sector 2, 020021 Bucharest, Romania
| | - Enachiuc Maria
- Faculty of Medicine, University of Medicine and Pharmacy Carol Davila, No. 37, Dionisie Lupu Street, Sector 2, 020021 Bucharest, Romania
| | - Daniela Adriana Ion
- Faculty of Medicine, University of Medicine and Pharmacy Carol Davila, No. 37, Dionisie Lupu Street, Sector 2, 020021 Bucharest, Romania
| | - Mihaela Cristina Olariu
- Faculty of Medicine, University of Medicine and Pharmacy Carol Davila, No. 37, Dionisie Lupu Street, Sector 2, 020021 Bucharest, Romania
- National Institute for Infectious Diseases Prof. Dr. Matei Bals, No. 1, Calistrat Grozovici Street, Sector 2, 021105 Bucharest, Romania
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2
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Gonzalez-Garcia P, Fiorillo Moreno O, Zarate Peñata E, Calderon-Villalba A, Pacheco Lugo L, Acosta Hoyos A, Villarreal Camacho JL, Navarro Quiroz R, Pacheco Londoño L, Aroca Martinez G, Moares N, Gabucio A, Fernandez-Ponce C, Garcia-Cozar F, Navarro Quiroz E. From Cell to Symptoms: The Role of SARS-CoV-2 Cytopathic Effects in the Pathogenesis of COVID-19 and Long COVID. Int J Mol Sci 2023; 24:ijms24098290. [PMID: 37175995 PMCID: PMC10179575 DOI: 10.3390/ijms24098290] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Revised: 04/23/2023] [Accepted: 04/26/2023] [Indexed: 05/15/2023] Open
Abstract
Severe Acute Respiratory Syndrome CoronaVirus 2 (SARS-CoV-2) infection triggers various events from molecular to tissue level, which in turn is given by the intrinsic characteristics of each patient. Given the molecular diversity characteristic of each cellular phenotype, the possible cytopathic, tissue and clinical effects are difficult to predict, which determines the heterogeneity of COVID-19 symptoms. The purpose of this article is to provide a comprehensive review of the cytopathic effects of SARS-CoV-2 on various cell types, focusing on the development of COVID-19, which in turn may lead, in some patients, to a persistence of symptoms after recovery from the disease, a condition known as long COVID. We describe the molecular mechanisms underlying virus-host interactions, including alterations in protein expression, intracellular signaling pathways, and immune responses. In particular, the article highlights the potential impact of these cytopathies on cellular function and clinical outcomes, such as immune dysregulation, neuropsychiatric disorders, and organ damage. The article concludes by discussing future directions for research and implications for the management and treatment of COVID-19 and long COVID.
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Affiliation(s)
| | - Ornella Fiorillo Moreno
- Clínica Iberoamerica, Barranquilla 080001, Colombia
- Life Science Research Center, Universidad Simon Bolívar, Barranquilla 080001, Colombia
| | - Eloina Zarate Peñata
- Life Science Research Center, Universidad Simon Bolívar, Barranquilla 080001, Colombia
| | | | - Lisandro Pacheco Lugo
- Life Science Research Center, Universidad Simon Bolívar, Barranquilla 080001, Colombia
| | - Antonio Acosta Hoyos
- Life Science Research Center, Universidad Simon Bolívar, Barranquilla 080001, Colombia
| | | | - Roberto Navarro Quiroz
- Department of Structural and Molecular Biology, Molecular Biology Institute of Barcelona, Spanish National Research Council, 08028 Barcelona, Spain
| | | | - Gustavo Aroca Martinez
- Life Science Research Center, Universidad Simon Bolívar, Barranquilla 080001, Colombia
- School of Medicine, Universidad del Norte, Barranquilla 080001, Colombia
| | - Noelia Moares
- Department of Biomedicine, Biotechnology and Public Health, Faculty of Medicine, University of Cadiz, 11003 Cádiz, Spain
| | - Antonio Gabucio
- Department of Biomedicine, Biotechnology and Public Health, Faculty of Medicine, University of Cadiz, 11003 Cádiz, Spain
| | - Cecilia Fernandez-Ponce
- Institute of Biomedical Research Cadiz (INIBICA), 11009 Cádiz, Spain
- Department of Biomedicine, Biotechnology and Public Health, Faculty of Medicine, University of Cadiz, 11003 Cádiz, Spain
| | - Francisco Garcia-Cozar
- Institute of Biomedical Research Cadiz (INIBICA), 11009 Cádiz, Spain
- Department of Biomedicine, Biotechnology and Public Health, Faculty of Medicine, University of Cadiz, 11003 Cádiz, Spain
| | - Elkin Navarro Quiroz
- Life Science Research Center, Universidad Simon Bolívar, Barranquilla 080001, Colombia
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3
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Noori L, Filip K, Nazmara Z, Mahakizadeh S, Hassanzadeh G, Caruso Bavisotto C, Bucchieri F, Marino Gammazza A, Cappello F, Wnuk M, Scalia F. Contribution of Extracellular Vesicles and Molecular Chaperones in Age-Related Neurodegenerative Disorders of the CNS. Int J Mol Sci 2023; 24:927. [PMID: 36674442 PMCID: PMC9861359 DOI: 10.3390/ijms24020927] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2022] [Revised: 12/22/2022] [Accepted: 12/30/2022] [Indexed: 01/06/2023] Open
Abstract
Many neurodegenerative disorders are characterized by the abnormal aggregation of misfolded proteins that form amyloid deposits which possess prion-like behavior such as self-replication, intercellular transmission, and consequent induction of native forms of the same protein in surrounding cells. The distribution of the accumulated proteins and their correlated toxicity seem to be involved in the progression of nervous system degeneration. Molecular chaperones are known to maintain proteostasis, contribute to protein refolding to protect their function, and eliminate fatally misfolded proteins, prohibiting harmful effects. However, chaperone network efficiency declines during aging, prompting the onset and the development of neurological disorders. Extracellular vesicles (EVs) are tiny membranous structures produced by a wide range of cells under physiological and pathological conditions, suggesting their significant role in fundamental processes particularly in cellular communication. They modulate the behavior of nearby and distant cells through their biological cargo. In the pathological context, EVs transport disease-causing entities, including prions, α-syn, and tau, helping to spread damage to non-affected areas and accelerating the progression of neurodegeneration. However, EVs are considered effective for delivering therapeutic factors to the nervous system, since they are capable of crossing the blood-brain barrier (BBB) and are involved in the transportation of a variety of cellular entities. Here, we review the neurodegeneration process caused mainly by the inefficiency of chaperone systems as well as EV performance in neuropathies, their potential as diagnostic biomarkers and a promising EV-based therapeutic approach.
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Affiliation(s)
- Leila Noori
- Department of Biomedicine, Neuroscience and Advanced Diagnostics (BIND), University of Palermo, 90127 Palermo, Italy
- Department of Anatomy, School of Medicine, Tehran University of Medical Sciences, Tehran 1417653761, Iran
| | - Kamila Filip
- Department of Biology, Institute of Biology and Biotechnology, College of Natural Sciences, University of Rzeszow, 35959 Rzeszow, Poland
| | - Zohreh Nazmara
- Department of Neuroscience and Addiction Studies, School of Advanced Technologies in Medicine, Tehran University of Medical Sciences, Tehran 1417653761, Iran
| | - Simin Mahakizadeh
- Department of Anatomy, School of Medicine, Alborz University of Medical Sciences, Karaj 3149779453, Iran
| | - Gholamreza Hassanzadeh
- Department of Anatomy, School of Medicine, Tehran University of Medical Sciences, Tehran 1417653761, Iran
- Department of Neuroscience and Addiction Studies, School of Advanced Technologies in Medicine, Tehran University of Medical Sciences, Tehran 1417653761, Iran
| | - Celeste Caruso Bavisotto
- Department of Biomedicine, Neuroscience and Advanced Diagnostics (BIND), University of Palermo, 90127 Palermo, Italy
- Euro-Mediterranean Institute of Science and Technology (IEMEST), 90139 Palermo, Italy
| | - Fabio Bucchieri
- Department of Biomedicine, Neuroscience and Advanced Diagnostics (BIND), University of Palermo, 90127 Palermo, Italy
| | - Antonella Marino Gammazza
- Department of Biomedicine, Neuroscience and Advanced Diagnostics (BIND), University of Palermo, 90127 Palermo, Italy
| | - Francesco Cappello
- Department of Biomedicine, Neuroscience and Advanced Diagnostics (BIND), University of Palermo, 90127 Palermo, Italy
- Euro-Mediterranean Institute of Science and Technology (IEMEST), 90139 Palermo, Italy
| | - Maciej Wnuk
- Department of Biotechnology, Institute of Biology and Biotechnology, College of Natural Sciences, University of Rzeszow, 35959 Rzeszow, Poland
| | - Federica Scalia
- Department of Biomedicine, Neuroscience and Advanced Diagnostics (BIND), University of Palermo, 90127 Palermo, Italy
- Euro-Mediterranean Institute of Science and Technology (IEMEST), 90139 Palermo, Italy
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4
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Pemberton S, Galindo DC, Schwartz MW, Banks WA, Rhea EM. Endocytosis of insulin at the blood-brain barrier. FRONTIERS IN DRUG DELIVERY 2022; 2:1062366. [PMID: 37936681 PMCID: PMC10629879 DOI: 10.3389/fddev.2022.1062366] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/09/2023]
Abstract
For insulin to act within the brain, it is primarily transported from the blood across the blood-brain barrier (BBB). However, the endocytic machinery necessary for delivering insulin to the brain remains unknown. Additionally, there are processes within the brain endothelial cell that are designed to respond to insulin binding and elicit intracellular signaling. Using pharmacological inhibitors of different types of endocytosis (clathrin-vs. caveolin-mediated), we investigated molecular mediators of both insulin BBB binding in isolated mouse brain microvessels and BBB insulin transport in mice studied by brain perfusion. We found clathrin-mediated mechanisms responsible for insulin surface binding in isolated brain microvessels while caveolin-mediated endocytosis may mediate BBB insulin transport specifically in the hypothalamus. These results further define the molecular machinery necessary for transporting insulin into the CNS and highlight the distinction between insulin internalization for transendothelial transport vs. intracellular signaling.
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Affiliation(s)
- Sarah Pemberton
- Geriatric Research Education and Clinical Center, VA Puget Sound Health Care System, Seattle, WA, United States
| | - Demi C Galindo
- Geriatric Research Education and Clinical Center, VA Puget Sound Health Care System, Seattle, WA, United States
| | - Michael W Schwartz
- Division of Metabolism, Endocrinology and Nutrition, Department of Medicine, School of Medicine, University of Washington, Seattle, WA, United States
| | - William A Banks
- Geriatric Research Education and Clinical Center, VA Puget Sound Health Care System, Seattle, WA, United States
- Division of Gerontology and Geriatric Medicine, Department of Medicine, School of Medicine, University of Washington, Seattle, WA, United States
| | - Elizabeth M Rhea
- Geriatric Research Education and Clinical Center, VA Puget Sound Health Care System, Seattle, WA, United States
- Division of Gerontology and Geriatric Medicine, Department of Medicine, School of Medicine, University of Washington, Seattle, WA, United States
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5
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Killingsworth L, Spudich S. Neuropathogenesis of HIV-1: insights from across the spectrum of acute through long-term treated infection. Semin Immunopathol 2022; 44:709-724. [PMID: 35882661 PMCID: PMC10126949 DOI: 10.1007/s00281-022-00953-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2022] [Accepted: 05/20/2022] [Indexed: 01/16/2023]
Abstract
This review outlines the neuropathogenesis of HIV, from initial HIV entry into the central nervous system (CNS) to chronic infection, focusing on key advancements in the last 5 years. Discoveries regarding acute HIV infection reveal timing and mechanisms of early HIV entry and replication in the CNS, early inflammatory responses, and establishment of genetically distinct viral reservoirs in the brain. Recent studies additionally explore how chronic HIV infection is maintained in the CNS, examining how the virus remains in a latent "hidden" state in diverse cells in the brain, and how this leads to sustained pathological inflammatory responses. Despite viral suppression with antiretroviral therapy, HIV can persist and even replicate in the CNS, and associate with ongoing neuropathology including CD8 + T-lymphocyte mediated encephalitis. Crucial investigation to advance our understanding of the immune mechanisms that both control viral infection and lead to pathological consequences in the brain is necessary to develop treatments to optimize long-term neurologic health in people living with HIV.
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Affiliation(s)
- Lauren Killingsworth
- Department of Neurology, Yale University School of Medicine, 300 George Street, Room 8300c, New Haven, CT, 06520, USA
| | - Serena Spudich
- Department of Neurology, Yale University School of Medicine, 300 George Street, Room 8300c, New Haven, CT, 06520, USA.
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6
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Poustforoosh A, Nematollahi MH, Hashemipour H, Pardakhty A. Recent advances in Bio-conjugated nanocarriers for crossing the Blood-Brain Barrier in (pre-)clinical studies with an emphasis on vesicles. J Control Release 2022; 343:777-797. [DOI: 10.1016/j.jconrel.2022.02.015] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2021] [Revised: 02/10/2022] [Accepted: 02/12/2022] [Indexed: 12/12/2022]
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7
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Apostol CR, Bernard K, Tanguturi P, Molnar G, Bartlett MJ, Szabò L, Liu C, Ortiz JB, Saber M, Giordano KR, Green TRF, Melvin J, Morrison HW, Madhavan L, Rowe RK, Streicher JM, Heien ML, Falk T, Polt R. Design and Synthesis of Brain Penetrant Glycopeptide Analogues of PACAP With Neuroprotective Potential for Traumatic Brain Injury and Parkinsonism. FRONTIERS IN DRUG DISCOVERY 2022; 1. [PMID: 35237767 PMCID: PMC8887546 DOI: 10.3389/fddsv.2021.818003] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
There is an unmet clinical need for curative therapies to treat neurodegenerative disorders. Most mainstay treatments currently on the market only alleviate specific symptoms and do not reverse disease progression. The Pituitary adenylate cyclase-activating polypeptide (PACAP), an endogenous neuropeptide hormone, has been extensively studied as a potential regenerative therapeutic. PACAP is widely distributed in the central nervous system (CNS) and exerts its neuroprotective and neurotrophic effects via the related Class B GPCRs PAC1, VPAC1, and VPAC2, at which the hormone shows roughly equal activity. Vasoactive intestinal peptide (VIP) also activates these receptors, and this close analogue of PACAP has also shown to promote neuronal survival in various animal models of acute and progressive neurodegenerative diseases. However, PACAP's poor pharmacokinetic profile (non-linear PK/PD), and more importantly its limited blood-brain barrier (BBB) permeability has hampered development of this peptide as a therapeutic. We have demonstrated that glycosylation of PACAP and related peptides promotes penetration of the BBB and improves PK properties while retaining efficacy and potency in the low nanomolar range at its target receptors. Furthermore, judicious structure-activity relationship (SAR) studies revealed key motifs that can be modulated to afford compounds with diverse selectivity profiles. Most importantly, we have demonstrated that select PACAP glycopeptide analogues (2LS80Mel and 2LS98Lac) exert potent neuroprotective effects and anti-inflammatory activity in animal models of traumatic brain injury and in a mild-toxin lesion model of Parkinson's disease, highlighting glycosylation as a viable strategy for converting endogenous peptides into robust and efficacious drug candidates.
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Affiliation(s)
- Christopher R Apostol
- Department of Chemistry and Biochemistry, BIO5, The University of Arizona, Tucson, AZ, United States
| | - Kelsey Bernard
- Graduate Interdisciplinary Program in Physiological Sciences, The University of Arizona, Tucson, AZ, United States
| | | | - Gabriella Molnar
- Department of Pharmacology, College of Medicine, The University of Arizona, Tucson, AZ, United States
| | - Mitchell J Bartlett
- Department of Neurology, College of Medicine, The University of Arizona, Tucson, AZ, United States
| | - Lajos Szabò
- Department of Chemistry and Biochemistry, BIO5, The University of Arizona, Tucson, AZ, United States
| | - Chenxi Liu
- Department of Chemistry and Biochemistry, BIO5, The University of Arizona, Tucson, AZ, United States
| | - J Bryce Ortiz
- Barrow Neurological Institute at Phoenix Children's Hospital, The University of Arizona College of Medicine-Phoenix, Phoenix, AZ, United States.,Department of Child Health, The University of Arizona College of Medicine-Phoenix, Phoenix, AZ, United States.,Phoenix Veteran Affairs Health Care System, Phoenix, AZ, United States
| | - Maha Saber
- Barrow Neurological Institute at Phoenix Children's Hospital, The University of Arizona College of Medicine-Phoenix, Phoenix, AZ, United States.,Department of Child Health, The University of Arizona College of Medicine-Phoenix, Phoenix, AZ, United States
| | - Katherine R Giordano
- Barrow Neurological Institute at Phoenix Children's Hospital, The University of Arizona College of Medicine-Phoenix, Phoenix, AZ, United States.,Department of Child Health, The University of Arizona College of Medicine-Phoenix, Phoenix, AZ, United States.,Phoenix Veteran Affairs Health Care System, Phoenix, AZ, United States
| | - Tabitha R F Green
- Department of Child Health, The University of Arizona College of Medicine-Phoenix, Phoenix, AZ, United States
| | - James Melvin
- Department of Child Health, The University of Arizona College of Medicine-Phoenix, Phoenix, AZ, United States.,Department of Biological Sciences, University of Bath, Bath, United Kingdom
| | - Helena W Morrison
- College of Nursing, University of Arizona, Tucson, AZ, United States
| | - Lalitha Madhavan
- Graduate Interdisciplinary Program in Physiological Sciences, The University of Arizona, Tucson, AZ, United States.,Department of Neurology, College of Medicine, The University of Arizona, Tucson, AZ, United States
| | - Rachel K Rowe
- Barrow Neurological Institute at Phoenix Children's Hospital, The University of Arizona College of Medicine-Phoenix, Phoenix, AZ, United States.,Department of Child Health, The University of Arizona College of Medicine-Phoenix, Phoenix, AZ, United States.,Department of Integrative Physiology, University of Colorado Boulder, Boulder, CO, United States
| | - John M Streicher
- Department of Pharmacology, College of Medicine, The University of Arizona, Tucson, AZ, United States
| | - Michael L Heien
- Department of Chemistry and Biochemistry, BIO5, The University of Arizona, Tucson, AZ, United States
| | - Torsten Falk
- Graduate Interdisciplinary Program in Physiological Sciences, The University of Arizona, Tucson, AZ, United States.,Department of Pharmacology, College of Medicine, The University of Arizona, Tucson, AZ, United States.,Department of Neurology, College of Medicine, The University of Arizona, Tucson, AZ, United States
| | - Robin Polt
- Department of Chemistry and Biochemistry, BIO5, The University of Arizona, Tucson, AZ, United States
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8
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Erickson MA, Rhea EM, Knopp RC, Banks WA. Interactions of SARS-CoV-2 with the Blood-Brain Barrier. Int J Mol Sci 2021; 22:2681. [PMID: 33800954 PMCID: PMC7961671 DOI: 10.3390/ijms22052681] [Citation(s) in RCA: 97] [Impact Index Per Article: 32.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Revised: 03/03/2021] [Accepted: 03/04/2021] [Indexed: 01/08/2023] Open
Abstract
Emerging data indicate that neurological complications occur as a consequence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. The blood-brain barrier (BBB) is a critical interface that regulates entry of circulating molecules into the CNS, and is regulated by signals that arise from the brain and blood compartments. In this review, we discuss mechanisms by which SARS-CoV-2 interactions with the BBB may contribute to neurological dysfunction associated with coronavirus disease of 2019 (COVID-19), which is caused by SARS-CoV-2. We consider aspects of peripheral disease, such as hypoxia and systemic inflammatory response syndrome/cytokine storm, as well as CNS infection and mechanisms of viral entry into the brain. We also discuss the contribution of risk factors for developing severe COVID-19 to BBB dysfunction that could increase viral entry or otherwise damage the brain.
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Affiliation(s)
- Michelle A. Erickson
- Geriatric Research Education and Clinical Center, VA Puget Sound Healthcare System, Seattle, WA 98108, USA; (E.M.R.); (R.C.K.)
- Division of Gerontology and Geriatric Medicine, Department of Medicine, University of Washington School of Medicine, Seattle, WA 98104, USA
| | - Elizabeth M. Rhea
- Geriatric Research Education and Clinical Center, VA Puget Sound Healthcare System, Seattle, WA 98108, USA; (E.M.R.); (R.C.K.)
- Division of Gerontology and Geriatric Medicine, Department of Medicine, University of Washington School of Medicine, Seattle, WA 98104, USA
| | - Rachel C. Knopp
- Geriatric Research Education and Clinical Center, VA Puget Sound Healthcare System, Seattle, WA 98108, USA; (E.M.R.); (R.C.K.)
- Division of Gerontology and Geriatric Medicine, Department of Medicine, University of Washington School of Medicine, Seattle, WA 98104, USA
| | - William A. Banks
- Geriatric Research Education and Clinical Center, VA Puget Sound Healthcare System, Seattle, WA 98108, USA; (E.M.R.); (R.C.K.)
- Division of Gerontology and Geriatric Medicine, Department of Medicine, University of Washington School of Medicine, Seattle, WA 98104, USA
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9
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Rhea EM, Logsdon AF, Hansen KM, Williams LM, Reed MJ, Baumann KK, Holden SJ, Raber J, Banks WA, Erickson MA. The S1 protein of SARS-CoV-2 crosses the blood-brain barrier in mice. Nat Neurosci 2021; 24:368-378. [PMID: 33328624 PMCID: PMC8793077 DOI: 10.1038/s41593-020-00771-8] [Citation(s) in RCA: 259] [Impact Index Per Article: 86.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2020] [Accepted: 11/30/2020] [Indexed: 02/02/2023]
Abstract
It is unclear whether severe acute respiratory syndrome coronavirus 2, which causes coronavirus disease 2019, can enter the brain. Severe acute respiratory syndrome coronavirus 2 binds to cells via the S1 subunit of its spike protein. We show that intravenously injected radioiodinated S1 (I-S1) readily crossed the blood-brain barrier in male mice, was taken up by brain regions and entered the parenchymal brain space. I-S1 was also taken up by the lung, spleen, kidney and liver. Intranasally administered I-S1 also entered the brain, although at levels roughly ten times lower than after intravenous administration. APOE genotype and sex did not affect whole-brain I-S1 uptake but had variable effects on uptake by the olfactory bulb, liver, spleen and kidney. I-S1 uptake in the hippocampus and olfactory bulb was reduced by lipopolysaccharide-induced inflammation. Mechanistic studies indicated that I-S1 crosses the blood-brain barrier by adsorptive transcytosis and that murine angiotensin-converting enzyme 2 is involved in brain and lung uptake, but not in kidney, liver or spleen uptake.
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Affiliation(s)
- Elizabeth M. Rhea
- Geriatrics Research Education and Clinical Center, Veterans Affairs Puget Sound Health Care System, Seattle, WA USA,Division of Gerontology and Geriatric Medicine, Department of Medicine, University of Washington School of Medicine, Seattle, WA USA
| | - Aric F. Logsdon
- Geriatrics Research Education and Clinical Center, Veterans Affairs Puget Sound Health Care System, Seattle, WA USA,Division of Gerontology and Geriatric Medicine, Department of Medicine, University of Washington School of Medicine, Seattle, WA USA
| | - Kim M. Hansen
- Geriatrics Research Education and Clinical Center, Veterans Affairs Puget Sound Health Care System, Seattle, WA USA
| | - Lindsey M. Williams
- Geriatrics Research Education and Clinical Center, Veterans Affairs Puget Sound Health Care System, Seattle, WA USA
| | - May J. Reed
- Geriatrics Research Education and Clinical Center, Veterans Affairs Puget Sound Health Care System, Seattle, WA USA,Division of Gerontology and Geriatric Medicine, Department of Medicine, University of Washington School of Medicine, Seattle, WA USA
| | - Kristen K. Baumann
- Geriatrics Research Education and Clinical Center, Veterans Affairs Puget Sound Health Care System, Seattle, WA USA
| | - Sarah J. Holden
- Department of Behavioral Neurosciences, Oregon Health & Science University, Portland, OR USA
| | - Jacob Raber
- Department of Behavioral Neurosciences, Oregon Health & Science University, Portland, OR USA,Department of Neurology, Psychiatry, and Radiation Medicine; Division of Neuroscience, Departments of Neurology and Radiation Medicine, ONPRC, Oregon Health & Science University, Portland, OR USA
| | - William A. Banks
- Geriatrics Research Education and Clinical Center, Veterans Affairs Puget Sound Health Care System, Seattle, WA USA,Division of Gerontology and Geriatric Medicine, Department of Medicine, University of Washington School of Medicine, Seattle, WA USA,Corresponding author: WAB, 1/810C, 1660 S Columbian Way, Seattle, WA 98108 Phone: 206 764 2701,
| | - Michelle A. Erickson
- Geriatrics Research Education and Clinical Center, Veterans Affairs Puget Sound Health Care System, Seattle, WA USA,Division of Gerontology and Geriatric Medicine, Department of Medicine, University of Washington School of Medicine, Seattle, WA USA
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10
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Joshi BS, Zuhorn IS. Heparan sulfate proteoglycan-mediated dynamin-dependent transport of neural stem cell exosomes in an in vitro blood-brain barrier model. Eur J Neurosci 2020; 53:706-719. [PMID: 32939863 PMCID: PMC7891616 DOI: 10.1111/ejn.14974] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Revised: 08/10/2020] [Accepted: 09/02/2020] [Indexed: 12/12/2022]
Abstract
Drug delivery to the brain is greatly hampered by the presence of the blood–brain barrier (BBB) which tightly regulates the passage of molecules from blood to brain and vice versa. Nanocarriers, in which drugs can be encapsulated, can move across the blood–brain barrier (BBB) via the process of transcytosis, thus showing promise to improve drug delivery to the brain. Here, we demonstrate the use of natural nanovesicles, that is, exosomes, derived from C17.2 neural stem cells (NSCs) to efficiently carry a protein cargo across an in vitro BBB model consisting of human brain microvascular endothelial cells. We show that the exosomes are primarily taken up in brain endothelial cells via endocytosis, while heparan sulfate proteoglycans (HSPGs) act as receptors. Taken together, our data support the view that NSC exosomes may act as biological nanocarriers for efficient passage across the BBB. Nanomedicines that target HSPGs may improve their binding to brain endothelial cells and, possibly, show subsequent transcytosis across the BBB.
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Affiliation(s)
- Bhagyashree S Joshi
- Department of Biomedical Engineering, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Inge S Zuhorn
- Department of Biomedical Engineering, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
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11
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Transport of Extracellular Vesicles across the Blood-Brain Barrier: Brain Pharmacokinetics and Effects of Inflammation. Int J Mol Sci 2020; 21:ijms21124407. [PMID: 32575812 PMCID: PMC7352415 DOI: 10.3390/ijms21124407] [Citation(s) in RCA: 270] [Impact Index Per Article: 67.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Revised: 06/08/2020] [Accepted: 06/10/2020] [Indexed: 01/08/2023] Open
Abstract
Extracellular vesicles can cross the blood–brain barrier (BBB), but little is known about passage. Here, we used multiple-time regression analysis to examine the ability of 10 exosome populations derived from mouse, human, cancerous, and non-cancerous cell lines to cross the BBB. All crossed the BBB, but rates varied over 10-fold. Lipopolysaccharide (LPS), an activator of the innate immune system, enhanced uptake independently of BBB disruption for six exosomes and decreased uptake for one. Wheatgerm agglutinin (WGA) modulated transport of five exosome populations, suggesting passage by adsorptive transcytosis. Mannose 6-phosphate inhibited uptake of J774A.1, demonstrating that its BBB transporter is the mannose 6-phosphate receptor. Uptake rates, patterns, and effects of LPS or WGA were not predicted by exosome source (mouse vs. human) or cancer status of the cell lines. The cell surface proteins CD46, AVβ6, AVβ3, and ICAM-1 were variably expressed but not predictive of transport rate nor responses to LPS or WGA. A brain-to-blood efflux mechanism variably affected CNS retention and explains how CNS-derived exosomes enter blood. In summary, all exosomes tested here readily crossed the BBB, but at varying rates and by a variety of vesicular-mediated mechanisms involving specific transporters, adsorptive transcytosis, and a brain-to-blood efflux system.
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12
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Finke JM, Banks WA. Modulators of IgG penetration through the blood-brain barrier: Implications for Alzheimer's disease immunotherapy. Hum Antibodies 2018; 25:131-146. [PMID: 28035915 DOI: 10.3233/hab-160306] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
This review serves to highlight approaches that may improve the access of antibody drugs to regions of the brain affected by Alzheimer's Disease. While previous antibody drugs have been unsuccessful in treating Alzheimer's disease, recent work demonstrates that Alzheimer's pathology can be modified if these drugs can penetrate the brain parenchyma with greater efficacy. Research in antibody blood-brain barrier drug delivery predominantly follows one of three distinct directions: (1) enhancing influx with reduced antibody size, addition of Trojan horse modules, or blood-brain barrier disruption; (2) modulating trancytotic equilibrium and/or kinetics of the neonatal Fc Receptor; and (3) manipulation of antibody glycan carbohydrate composition. In addition to these topics, recent studies are discussed that reveal a role of glycan sialic acid in suppressing antibody efflux from the brain.
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Affiliation(s)
- John M Finke
- Division of Sciences and Mathematics, Interdisciplinary Arts and Sciences, University of Washington Tacoma, Tacoma, WA, USA
| | - William A Banks
- Geriatric Research Education and Clinical Center, VA Puget Sound Health Care System, Seattle, WA, USA.,Department of Geriatric Medicine, Division of Gerontology and Geriatric Medicine, University of Washington School of Medicine, Seattle, WA, USA
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13
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Matsumoto J, Stewart T, Sheng L, Li N, Bullock K, Song N, Shi M, Banks WA, Zhang J. Transmission of α-synuclein-containing erythrocyte-derived extracellular vesicles across the blood-brain barrier via adsorptive mediated transcytosis: another mechanism for initiation and progression of Parkinson's disease? Acta Neuropathol Commun 2017; 5:71. [PMID: 28903781 PMCID: PMC5598000 DOI: 10.1186/s40478-017-0470-4] [Citation(s) in RCA: 178] [Impact Index Per Article: 25.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2017] [Accepted: 08/24/2017] [Indexed: 02/07/2023] Open
Abstract
Parkinson’s disease (PD) pathophysiology develops in part from the formation, transmission, and aggregation of toxic species of the protein α-synuclein (α-syn). Recent evidence suggests that extracellular vesicles (EVs) may play a vital role in the transport of toxic α-syn between brain regions. Moreover, increasing evidence has highlighted the participation of peripheral molecules, particularly inflammatory species, which may influence or exacerbate the development of PD-related changes to the central nervous system (CNS), although detailed characterization of these species remains to be completed. Despite these findings, little attention has been devoted to erythrocytes, which contain α-syn concentrations ~1000-fold higher than the cerebrospinal fluid, as a source of potentially pathogenic α-syn. Here, we demonstrate that erythrocytes produce α-syn-rich EVs, which can cross the BBB, particularly under inflammatory conditions provoked by peripheral administration of lipopolysaccharide. This transport likely occurs via adsorptive-mediated transcytosis, with EVs that transit the BBB co-localizing with brain microglia. Examination of microglial reactivity upon exposure to α-syn-containing erythrocyte EVs in vitro and in vivo revealed that uptake provoked an increase in microglial inflammatory responses. EVs derived from the erythrocytes of PD patients elicited stronger responses than did those of control subjects, suggesting that inherent characteristics of EVs arising in the periphery might contribute to, or even initiate, CNS α-syn-related pathology. These results provide new insight into the mechanisms by which the brain and periphery communicate throughout the process of synucleinopathy pathogenesis.
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Abstract
BACKGROUND Drug delivery to the brain is a major roadblock to treatment of Alzheimer's disease. Recent results of the PRIME study indicate that increasing brain penetration of antibody drugs improves Alzheimer's treatment outcomes. New approaches are needed to better accomplish this goal. Based on prior evidence, the hypothesis that glycan modification alters antibody blood-brain barrier permeability was tested here. METHODS The blood-brain barrier permeability coefficient Pe of different glycosylated states of anti-amyloid IgG was measured using in vitro models of brain microvascular endothelial cells. Monoclonal antibodies 4G8, with sialic acid, and 6E10, lacking sialic acid, were studied. The amount of sialic acid was determined using quantitative and semi-quantitative surface plasmon resonance methods. RESULTS Influx of IgG was not saturable and was largely insensitive to IgG species and glycosylation state. By contrast, efflux of 4G8 efflux was significantly lower than both albumin controls and 6E10. Removal of α2,6-linked sialic acid group present on 12% of 4G8 completely restored efflux to that of 6E10 but increasing the α2,6-sialylated fraction to 15% resulted in no change. Removal of the Fc glycan from 4G8 partially restored efflux. Alternate sialic acid groups with α2,3 and α2,8 linkages, nor on the Fc glycan, were not detected at significant levels on either 4G8 or 6E10. CONCLUSIONS These results support a model in which surface-sialylated 4G8 inhibits its own efflux and that of asialylated 4G8. GENERAL SIGNIFICANCE Glycan modification has the potential to increase antibody drug penetration into the brain through efflux inhibition.
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Wächter C, Eiden LE, Naumann N, Depboylu C, Weihe E. Loss of cerebellar neurons in the progression of lentiviral disease: effects of CNS-permeant antiretroviral therapy. J Neuroinflammation 2016; 13:272. [PMID: 27737697 PMCID: PMC5064958 DOI: 10.1186/s12974-016-0726-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2016] [Accepted: 09/20/2016] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND The majority of investigations on HIV-associated neurocognitive disorders (HAND) neglect the cerebellum in spite of emerging evidence for its role in higher cognitive functions and dysfunctions in common neurodegenerative diseases. METHODS We systematically investigated the molecular and cellular responses of the cerebellum as contributors to lentiviral infection-induced neurodegeneration, in the simian immunodeficiency virus (SIV)-infected rhesus macaque model for HIV infection and HAND. Four cohorts of animals were studied: non-infected controls, SIV-infected asymptomatic animals, and SIV-infected AIDS-diseased animals with and without brain-permeant antiretroviral treatment. The antiretroviral utilized was 6-chloro-2',3'-dideoxyguanosine (6-Cl-ddG), a CNS-permeable nucleoside reverse transcriptase inhibitor. Quantitation of granule cells and Purkinje cells, of an established biomarker of SIV infection (gp41), of microglial/monocyte/macrophage markers (IBA-1, CD68, CD163), and of the astroglial marker (GFAP) were used to reveal cell-specific cerebellar responses to lentiviral infection and antiretroviral therapy (ART). The macromolecular integrity of the blood brain barrier was tested by albumin immunohistochemistry. RESULTS Productive CNS infection was observed in the symptomatic stage of disease, and correlated with extensive microglial/macrophage and astrocyte activation, and widespread macromolecular blood brain barrier defects. Signs of productive infection, and inflammation, were reversed upon treatment with 6-Cl-ddG, except for a residual low-grade activation of microglial cells and astrocytes. There was an extensive loss of granule cells in the SIV-infected asymptomatic cohort, which was further increased in the symptomatic stage of the disease and persisted after 6-Cl-ddG (administered after the onset of symptoms of AIDS). In the symptomatic stage, Purkinje cell density was reduced. Purkinje cell loss was likewise unaffected by 6-Cl-ddG treatment at this time. CONCLUSIONS Our findings suggest that neurodegenerative mechanisms are triggered by SIV infection early in the disease process, i. e., preceding large-scale cerebellar productive infection and marked neuroinflammation. These affect primarily granule cells early in disease, with later involvement of Purkinje cells, indicating differential vulnerability of the two neuronal populations. The results presented here indicate a role for the cerebellum in neuro-AIDS. They also support the conclusion that, in order to attenuate the development of motor and cognitive dysfunctions in HIV-positive individuals, CNS-permeant antiretroviral therapy combined with anti-inflammatory and neuroprotective treatment is indicated even before overt signs of CNS inflammation occur.
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Affiliation(s)
- Christian Wächter
- Molecular Neuroscience, Institute of Anatomy and Cell Biology, Philipps University Marburg, Robert-Koch-Str. 8, 35032, Marburg, Germany
| | - Lee E Eiden
- Section on Molecular Neuroscience, Laboratory of Cellular and Molecular Regulation, National Institute of Mental Health, NIH, Bethesda, MD, USA
| | - Nedye Naumann
- Molecular Neuroscience, Institute of Anatomy and Cell Biology, Philipps University Marburg, Robert-Koch-Str. 8, 35032, Marburg, Germany
| | - Candan Depboylu
- Molecular Neuroscience, Institute of Anatomy and Cell Biology, Philipps University Marburg, Robert-Koch-Str. 8, 35032, Marburg, Germany.,Experimental Neurology, Department of Neurology, Philipps University Marburg, Marburg, Germany
| | - Eberhard Weihe
- Molecular Neuroscience, Institute of Anatomy and Cell Biology, Philipps University Marburg, Robert-Koch-Str. 8, 35032, Marburg, Germany.
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Banks WA. From blood-brain barrier to blood-brain interface: new opportunities for CNS drug delivery. Nat Rev Drug Discov 2016; 15:275-92. [PMID: 26794270 DOI: 10.1038/nrd.2015.21] [Citation(s) in RCA: 711] [Impact Index Per Article: 88.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
One of the biggest challenges in the development of therapeutics for central nervous system (CNS) disorders is achieving sufficient blood-brain barrier (BBB) penetration. Research in the past few decades has revealed that the BBB is not only a substantial barrier for drug delivery to the CNS but also a complex, dynamic interface that adapts to the needs of the CNS, responds to physiological changes, and is affected by and can even promote disease. This complexity confounds simple strategies for drug delivery to the CNS, but provides a wealth of opportunities and approaches for drug development. Here, I review some of the most important areas that have recently redefined the BBB and discuss how they can be applied to the development of CNS therapeutics.
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Affiliation(s)
- William A Banks
- Veterans Affairs Puget Sound Health Care System, Geriatrics Research Education and Clinical Center and Department of Medicine, University of Washington School of Medicine, Division of Gerontology and Geriatric Medicine, 1660 South Columbian Way, Seattle, Washington 98108, USA
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Sampey GC, Saifuddin M, Schwab A, Barclay R, Punya S, Chung MC, Hakami RM, Zadeh MA, Lepene B, Klase ZA, El-Hage N, Young M, Iordanskiy S, Kashanchi F. Exosomes from HIV-1-infected Cells Stimulate Production of Pro-inflammatory Cytokines through Trans-activating Response (TAR) RNA. J Biol Chem 2015; 291:1251-66. [PMID: 26553869 DOI: 10.1074/jbc.m115.662171] [Citation(s) in RCA: 159] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2015] [Indexed: 12/22/2022] Open
Abstract
HIV-1 infection results in a chronic illness because long-term highly active antiretroviral therapy can lower viral titers to an undetectable level. However, discontinuation of therapy rapidly increases virus burden. Moreover, patients under highly active antiretroviral therapy frequently develop various metabolic disorders, neurocognitive abnormalities, and cardiovascular diseases. We have previously shown that exosomes containing trans-activating response (TAR) element RNA enhance susceptibility of undifferentiated naive cells to HIV-1 infection. This study indicates that exosomes from HIV-1-infected primary cells are highly abundant with TAR RNA as detected by RT-real time PCR. Interestingly, up to a million copies of TAR RNA/μl were also detected in the serum from HIV-1-infected humanized mice suggesting that TAR RNA may be stable in vivo. Incubation of exosomes from HIV-1-infected cells with primary macrophages resulted in a dramatic increase of proinflammatory cytokines, IL-6 and TNF-β, indicating that exosomes containing TAR RNA could play a direct role in control of cytokine gene expression. The intact TAR molecule was able to bind to PKR and TLR3 effectively, whereas the 5' and 3' stems (TAR microRNAs) bound best to TLR7 and -8 and none to PKR. Binding of TAR to PKR did not result in its phosphorylation, and therefore, TAR may be a dominant negative decoy molecule in cells. The TLR binding through either TAR RNA or TAR microRNA potentially can activate the NF-κB pathway and regulate cytokine expression. Collectively, these results imply that exosomes containing TAR RNA could directly affect the proinflammatory cytokine gene expression and may explain a possible mechanism of inflammation observed in HIV-1-infected patients under cART.
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Affiliation(s)
- Gavin C Sampey
- From the Laboratory of Molecular Virology, George Mason University, Manassas, Virginia 20110
| | - Mohammed Saifuddin
- From the Laboratory of Molecular Virology, George Mason University, Manassas, Virginia 20110
| | - Angela Schwab
- From the Laboratory of Molecular Virology, George Mason University, Manassas, Virginia 20110
| | - Robert Barclay
- From the Laboratory of Molecular Virology, George Mason University, Manassas, Virginia 20110
| | - Shreya Punya
- From the Laboratory of Molecular Virology, George Mason University, Manassas, Virginia 20110
| | - Myung-Chul Chung
- From the Laboratory of Molecular Virology, George Mason University, Manassas, Virginia 20110
| | - Ramin M Hakami
- From the Laboratory of Molecular Virology, George Mason University, Manassas, Virginia 20110
| | - Mohammad Asad Zadeh
- From the Laboratory of Molecular Virology, George Mason University, Manassas, Virginia 20110
| | | | - Zachary A Klase
- the Department of Biological Sciences, University of the Sciences, Philadelphia, Pennsylvania 19104
| | - Nazira El-Hage
- the Department of Immunology, Herbert Wertheim College of Medicine, Miami, Florida 33199, and
| | - Mary Young
- the Department of Medicine, Women's Intra-Agency HIV Study, Georgetown University, Washington, D. C. 20007
| | - Sergey Iordanskiy
- From the Laboratory of Molecular Virology, George Mason University, Manassas, Virginia 20110,
| | - Fatah Kashanchi
- From the Laboratory of Molecular Virology, George Mason University, Manassas, Virginia 20110,
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Thakur S, Kesharwani P, Tekade RK, Jain NK. Impact of pegylation on biopharmaceutical properties of dendrimers. POLYMER 2015. [DOI: 10.1016/j.polymer.2014.12.051] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Ashraf T, Jiang W, Hoque MT, Henderson J, Wu C, Bendayan R. Role of anti-inflammatory compounds in human immunodeficiency virus-1 glycoprotein120-mediated brain inflammation. J Neuroinflammation 2014; 11:91. [PMID: 24884548 PMCID: PMC4046047 DOI: 10.1186/1742-2094-11-91] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2014] [Accepted: 04/15/2014] [Indexed: 11/16/2022] Open
Abstract
BACKGROUND Neuroinflammation is a common immune response associated with brain human immunodeficiency virus-1 (HIV-1) infection. Identifying therapeutic compounds that exhibit better brain permeability and can target signaling pathways involved in inflammation may benefit treatment of HIV-associated neurological complications. The objective of this study was to implement an in vivo model of brain inflammation by intracerebroventricular administration of the HIV-1 viral coat protein gp120 in rats and to examine anti-inflammatory properties of HIV adjuvant therapies such as minocycline, chloroquine and simvastatin. METHODS Male Wistar rats were administered a single dose of gp120ADA (500 ng) daily for seven consecutive days, intracerebroventricularly, with or without prior intraperitoneal administration of minocycline, chloroquine or simvastatin. Maraviroc, a CCR5 antagonist, was administered intracerebroventricularly prior to gp120 administration for seven days as control. Real-time qPCR was used to assess gene expression of inflammatory markers in the frontal cortex, hippocampus and striatum. Interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α) secretion in cerebrospinal fluid (CSF) was measured applying ELISA. Protein expression of mitogen-activated protein kinases (MAPKs) (extracellular signal-related kinase 1/2 (ERK1/2), c-Jun N-terminal kinases (JNKs) and P38 kinases (P38Ks)) was detected using immunoblot analysis. Student's t-test and ANOVA were applied to determine statistical significance. RESULTS In gp120ADA-injected rats, mRNA transcripts of interleukin-1β (IL-1β) and inducible nitric oxide synthase (iNOS) were significantly elevated in the frontal cortex, striatum and hippocampus compared to saline or heat-inactivated gp120-injected controls. In CSF, a significant increase in TNF-α and IL-1β was detected. Maraviroc reduced upregulation of these markers suggesting that the interaction of R5-tropic gp120 to CCR5 chemokine receptor is critical for induction of an inflammatory response. Minocycline, chloroquine or simvastatin attenuated upregulation of IL-1β and iNOS transcripts in different brain regions. In CSF, minocycline suppressed TNF-α and IL-1β secretion, whereas chloroquine attenuated IL-1β secretion. In gp120-injected animals, activation of ERK1/2 and JNKs was observed in the hippocampus and ERK1/2 activation was significantly reduced by the anti-inflammatory agents. CONCLUSIONS Our data demonstrate that anti-inflammatory compounds can completely or partially reverse gp120-associated brain inflammation through an interaction with MAPK signaling pathways and suggest their potential role in contributing towards the prevention and treatment of HIV-associated neurological complications.
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Affiliation(s)
- Tamima Ashraf
- Department of Pharmaceutical Sciences, Leslie Dan Faculty of Pharmacy, University of Toronto, 144 College Street, Room 1001, Toronto, ON M5S 3 M2, Canada
| | - Wenlei Jiang
- Department of Pharmaceutical Sciences, Leslie Dan Faculty of Pharmacy, University of Toronto, 144 College Street, Room 1001, Toronto, ON M5S 3 M2, Canada
| | - Md Tozammel Hoque
- Department of Pharmaceutical Sciences, Leslie Dan Faculty of Pharmacy, University of Toronto, 144 College Street, Room 1001, Toronto, ON M5S 3 M2, Canada
| | - Jeffrey Henderson
- Department of Pharmaceutical Sciences, Leslie Dan Faculty of Pharmacy, University of Toronto, 144 College Street, Room 1001, Toronto, ON M5S 3 M2, Canada
| | - Chiping Wu
- Department of Pharmaceutical Sciences, Leslie Dan Faculty of Pharmacy, University of Toronto, 144 College Street, Room 1001, Toronto, ON M5S 3 M2, Canada
| | - Reina Bendayan
- Department of Pharmaceutical Sciences, Leslie Dan Faculty of Pharmacy, University of Toronto, 144 College Street, Room 1001, Toronto, ON M5S 3 M2, Canada
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20
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Innate Immunity in the CNS: Redefining the Relationship between the CNS and Its Environment. Neuron 2013; 78:214-32. [DOI: 10.1016/j.neuron.2013.04.005] [Citation(s) in RCA: 202] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/04/2013] [Indexed: 12/13/2022]
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21
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Smith MW, Al-Jayyoussi G, Gumbleton M. Peptide sequences mediating tropism to intact blood-brain barrier: an in vivo biodistribution study using phage display. Peptides 2012; 38:172-80. [PMID: 22955033 DOI: 10.1016/j.peptides.2012.06.019] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/07/2012] [Revised: 06/25/2012] [Accepted: 06/26/2012] [Indexed: 12/15/2022]
Abstract
Peptide motifs that demonstrate tropism for the blood brain barrier (BBB) are of real translational value in developing innovative delivery strategies for biological brain targeted therapies. In vivo peptide-phage display affords peptide selection against the full complement of biological markers within the correct cellular macro- and micro-environments. Here a stringent in vivo biopanning protocol was employed in the rat aimed at identifying cyclic 7-mer peptide motifs that mediate tropism to brain microvasculature. Five rounds of biopanning identified 349 unique peptide motifs in the brain tissue gray matter compartment (microvasculature and parenchyma). While in general no consensus was evident linking peptide physico-chemical properties and brain tropism, peptides bearing c-SxTSSTx-c or c-xxxSSTx-c motifs were found to be present in high abundance. Based on amino acid frequency distribution of the 349 unique peptides sequences a theoretical 'idealized' peptide pattern, c-PP(S/P)SSST-c, could be derived. For the most abundant experimental peptide sequence found in brain tissue, c-SYTSSTM-c, an in vivo pharmacokinetic and whole body tissue biodistribution study was performed. Based upon tissue exposure data (i.e. tissue AUC((0-infinity))) the sequence c-SYTSSTM-c efficiently retargeted phage virions to the brain providing an approximate 5-fold greater (P<0.05) accumulation in brain over control phage; in all other organs no significant (P>0.05) difference in tissue tropism between c-SYTSSTM-c and control phages were evident. This peptide and more generally the peptide motifs, -SxTSSTx- or -xxxSSTx-, warrant further investigation as agents mediating sequence-dependent tropism to brain microvasculature potentially able to deliver biologic cargo to the CNS.
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Affiliation(s)
- Mathew W Smith
- Cardiff School of Pharmacy & Pharmaceutical Sciences, Cardiff University, Cardiff, United Kingdom
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22
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Dohgu S, Ryerse JS, Robinson SM, Banks WA. Human immunodeficiency virus-1 uses the mannose-6-phosphate receptor to cross the blood-brain barrier. PLoS One 2012; 7:e39565. [PMID: 22761827 PMCID: PMC3382565 DOI: 10.1371/journal.pone.0039565] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2012] [Accepted: 05/27/2012] [Indexed: 12/03/2022] Open
Abstract
HIV-1 circulates both as free virus and within immune cells, with the level of free virus being predictive of clinical course. Both forms of HIV-1 cross the blood-brain barrier (BBB) and much progress has been made in understanding the mechanisms by which infected immune cells cross the blood-brain barrier BBB. How HIV-1 as free virus crosses the BBB is less clear as brain endothelial cells are CD4 and galactosylceramide negative. Here, we found that HIV-1 can use the mannose-6 phosphate receptor (M6PR) to cross the BBB. Brain perfusion studies showed that HIV-1 crossed the BBB of all brain regions consistent with the uniform distribution of M6PR. Ultrastructural studies showed HIV-1 crossed by a transcytotic pathway consistent with transport by M6PR. An in vitro model of the BBB was used to show that transport of HIV-1 was inhibited by mannose, mannan, and mannose-6 phosphate and that enzymatic removal of high mannose oligosaccharide residues from HIV-1 reduced transport. Wheatgerm agglutinin and protamine sulfate, substances known to greatly increase transcytosis of HIV-1 across the BBB in vivo, were shown to be active in the in vitro model and to act through a mannose-dependent mechanism. Transport was also cAMP and calcium-dependent, the latter suggesting that the cation-dependent member of the M6PR family mediates HIV-1 transport across the BBB. We conclude that M6PR is an important receptor used by HIV-1 to cross the BBB.
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Affiliation(s)
- Shinya Dohgu
- Department of Pharmaceutical Care and Health Sciences, Faculty of Pharmaceutical Sciences, Fukuoka University, Fukuoka, Japan
| | - Jan S. Ryerse
- Department of Pathology, Saint Louis University Health Sciences Center, St. Louis, Missouri, United States of America
| | - Sandra M. Robinson
- Division of Geriatric Medicine, Department of Internal Medicine, Saint Louis University School of Medicine, St. Louis, Missouri, United States of America
| | - William A. Banks
- Geriatric Research Educational and Clinical Center-Veterans Affairs Puget Sound Health Care System, Seattle, Washington, United States of America
- Division of Gerontology and Geriatric Medicine, Department of Medicine, University of Washington, Seattle, Washington, United States of America
- * E-mail:
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Malakoutikhah M, Teixidó M, Giralt E. Schleuservermittelter Transport von Wirkstoffen ins Gehirn. Angew Chem Int Ed Engl 2011. [DOI: 10.1002/ange.201006565] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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Malakoutikhah M, Teixidó M, Giralt E. Shuttle-Mediated Drug Delivery to the Brain. Angew Chem Int Ed Engl 2011; 50:7998-8014. [DOI: 10.1002/anie.201006565] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2010] [Revised: 01/17/2011] [Indexed: 12/12/2022]
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25
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Strazza M, Pirrone V, Wigdahl B, Nonnemacher MR. Breaking down the barrier: the effects of HIV-1 on the blood-brain barrier. Brain Res 2011; 1399:96-115. [PMID: 21641584 DOI: 10.1016/j.brainres.2011.05.015] [Citation(s) in RCA: 150] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2010] [Revised: 05/06/2011] [Accepted: 05/07/2011] [Indexed: 01/13/2023]
Abstract
Human immunodeficiency virus type 1 (HIV-1) primarily infects CD4(+) T cells and cells of the monocyte-macrophage lineage, resulting in immunodeficiency in an infected patient. Along with this immune deficiency, HIV-1 has been linked to a number of neurological symptoms in the absence of opportunistic infections or other co-morbidities, suggesting that HIV-1 is able to cross the blood-brain barrier (BBB), enter the central nervous system (CNS), and cause neurocognitive impairment. HIV-1-infected monocyte-macrophages traverse the BBB and enter the CNS throughout the course of HIV-1 disease. Once in the brain, both free virus and virus-infected cells are able to infect neighboring resident microglia and astrocytes and possibly other cell types. HIV-1-infected cells in both the periphery and the CNS give rise to elevated levels of viral proteins, including gp120, Tat, and Nef, and of host inflammatory mediators such as cytokines and chemokines. It has been shown that the viral proteins may act alone or in concert with host cytokines and chemokines, affecting the integrity of the BBB. The pathological end point of these interactions may facilitate a positive feedback loop resulting in increased penetration of HIV into the CNS. It is proposed in this review that the dysregulation of the BBB during and after neuroinvasion is a critical component of the neuropathogenic process and that dysregulation of this protective barrier is caused by a combination of viral and host factors including secreted viral proteins, components of the inflammatory process, the aging process, therapeutics, and drug or alcohol abuse.
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Affiliation(s)
- Marianne Strazza
- Department of Microbiology and Immunology, and Center for Molecular Virology and Translational Neuroscience, Institute for Molecular Medicine and Infectious Disease, Drexel University College of Medicine, Philadelphia, PA 19102, USA
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Guo JL, Lee VMY. Seeding of normal Tau by pathological Tau conformers drives pathogenesis of Alzheimer-like tangles. J Biol Chem 2011; 286:15317-31. [PMID: 21372138 DOI: 10.1074/jbc.m110.209296] [Citation(s) in RCA: 459] [Impact Index Per Article: 35.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Neurofibrillary tangles (NFTs) in Alzheimer disease and related tauopathies are composed of insoluble hyperphosphorylated Tau protein, but the mechanisms underlying the conversion of highly soluble Tau into insoluble NFTs remain elusive. Here, we demonstrate that introduction of minute quantities of misfolded preformed Tau fibrils (Tau pffs) into Tau-expressing cells rapidly recruit large amounts of soluble Tau into filamentous inclusions resembling NFTs with unprecedented efficiency, suggesting a "seeding"-recruitment process as a highly plausible mechanism underlying NFT formation in vivo. Consistent with the emerging concept of prion-like transmissibility of disease-causing amyloidogenic proteins, we found that spontaneous uptake of Tau pffs into cells is likely mediated by endocytosis, suggesting a potential mechanism for the propagation of Tau lesions in tauopathy brains. Furthermore, sequestration of soluble Tau by pff-induced Tau aggregates attenuates microtubule overstabilization in Tau-expressing cells, supporting the hypothesis of a Tau loss-of-function toxicity in cells harboring NFTs. In summary, our study establishes a cellular system that robustly develops authentic NFT-like Tau aggregates, which provides mechanistic insights into NFT pathogenesis and a potential tool for identifying Tau-based therapeutics.
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Affiliation(s)
- Jing L Guo
- Department of Pathology and Laboratory Medicine, Institute on Aging and Center for Neurodegenerative Disease Research, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania 19104, USA
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Malakoutikhah M, Prades R, Teixidó M, Giralt E. N-Methyl Phenylalanine-Rich Peptides as Highly Versatile Blood−Brain Barrier Shuttles. J Med Chem 2010; 53:2354-63. [DOI: 10.1021/jm901654x] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Affiliation(s)
- Morteza Malakoutikhah
- Institute for Research in Biomedicine (IRB Barcelona), Barcelona Science Park, Baldiri Reixac 10, E-08028 Barcelona, Spain
| | - Roger Prades
- Institute for Research in Biomedicine (IRB Barcelona), Barcelona Science Park, Baldiri Reixac 10, E-08028 Barcelona, Spain
| | - Meritxell Teixidó
- Institute for Research in Biomedicine (IRB Barcelona), Barcelona Science Park, Baldiri Reixac 10, E-08028 Barcelona, Spain
| | - Ernest Giralt
- Institute for Research in Biomedicine (IRB Barcelona), Barcelona Science Park, Baldiri Reixac 10, E-08028 Barcelona, Spain
- Department of Organic Chemistry, University of Barcelona, Martí i Franquès 1-11, Barcelona, Spain
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Banks WA. Mouse models of neurological disorders: a view from the blood-brain barrier. Biochim Biophys Acta Mol Basis Dis 2009; 1802:881-8. [PMID: 19879356 DOI: 10.1016/j.bbadis.2009.10.011] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2009] [Revised: 10/20/2009] [Accepted: 10/23/2009] [Indexed: 12/16/2022]
Abstract
The number of disease models that involve an aspect of blood-brain barrier (BBB) dysregulation have increased tremendously. The main factors contributing to this expansion have been an increased number of diseases in which the BBB is known to be involved, an increase in the known functions of the BBB, and an increase in the number of models and tools with which those diverse functions can be studied. In many cases, the BBB may be a target of disease; current thinking would include hypertensive encephalopathy and perhaps stroke in this category. Another category are those diseases in which special attributes of the BBB may predispose to disease; for example, the ability of a pathogen to cross the BBB often depends on the pathogen's ability to invoke transcytotic pathways in the brain endothelial or choroid plexus cell. Of special interest are those diseases in which the BBB may be the primary seat of disease or play a major role in the onset or progression of the disease. An increasing number of diseases are so categorized in which BBB dysfunction or dysregulation plays a major role; this review highlights such roles for the BBB including those proposed for Alzheimer's disease and obesity.
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Affiliation(s)
- William A Banks
- GRECC, Veterans Affairs Medical Center-St. Louis and Saint Louis University School of Medicine, Division of Geriatrics, Department of Internal Medicine, 915 N. Grand Blvd, St. Louis, MO 63106, USA.
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Dietrich JB. Alteration of blood-brain barrier function by methamphetamine and cocaine. Cell Tissue Res 2009; 336:385-92. [PMID: 19350275 DOI: 10.1007/s00441-009-0777-y] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2008] [Accepted: 02/03/2009] [Indexed: 01/06/2023]
Abstract
The integrity of the blood-brain barrier (BBB) plays an important role in maintaining a safe neural microenvironment in the brain. Loss of BBB integrity has been recognized as a major cause of profound brain alterations. Psychoactive drugs such as methamphetamine (METH) or cocaine are well-known drugs of abuse that can alter the permeability of the BBB via various mechanisms. In addition, the neurotoxicity of METH is well documented, and alterations in BBB function can contribute to this toxicity. A great deal of effort has been devoted to understanding the cellular and molecular mechanisms of the action of these drugs in the central nervous system. However, only a few investigations have focused on the effects of METH and cocaine on BBB function. The aim of this short review is to summarize our present knowledge of this subject.
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Affiliation(s)
- J B Dietrich
- Inserm U575, 5 Rue B. Pascal, 67084, Strasbourg, France.
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30
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Smith MW, Gumbleton M. Endocytosis at the blood–brain barrier: From basic understanding to drug delivery strategies. J Drug Target 2008; 14:191-214. [PMID: 16777679 DOI: 10.1080/10611860600650086] [Citation(s) in RCA: 107] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
The blood-brain barrier (BBB) protects the central nervous system (CNS) from potentially harmful xenobiotics and endogenous molecules. Anatomically, it comprises the brain microvasculature whose functionality is nevertheless influenced by associated astrocyte, pericyte and neuronal cells. The highly restrictive paracellular pathway within brain microvasculature restricts significant CNS penetration to only those drugs whose physicochemical properties afford ready penetration into hydrophobic cell membranes or are capable of exploiting endogenous active transport processes such as solute carriers or endocytosis pathways. Endocytosis at the BBB is an essential pathway by which the brain obtains its nutrients and affords communication with the periphery. The development of strategies to exploit these endocytic pathways for the purposes of drug delivery to the CNS is still an immature field although some impressive results have been documented with the targeting of particular receptors. This current article initially provides an overview of general endocytosis processes and pathways showing evidence of their functional existence within the BBB. Subsequent sections provide, in an entity-specific manner, comprehensive reviews on BBB transport investigations of endocytosis involving: transferrin and the targeting of the transferrin receptor; hormones; cytokines; cell penetrating peptides; microorganisms and toxins, and nanoparticles aimed at more effectively delivering drugs to the CNS.
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Affiliation(s)
- Mathew W Smith
- Pharmaceutical Cell Biology, Welsh School of Pharmacy, Cardiff University, Redwood Building, Cardiff CF10 3XF, UK
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Tight junction regulation by morphine and HIV-1 tat modulates blood-brain barrier permeability. J Clin Immunol 2008; 28:528-41. [PMID: 18574677 DOI: 10.1007/s10875-008-9208-1] [Citation(s) in RCA: 75] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2008] [Accepted: 05/19/2008] [Indexed: 12/13/2022]
Abstract
Human immunodeficiency virus (HIV)-1 patients who abuse opiates are at a greater risk of developing neurological complications of AIDS. Alterations in blood-brain barrier (BBB) integrity are associated with cytoskeletal disorganization and disruption of tight junction (TJ) integrity. We hypothesize that opiates in combination with HIV-1 viral proteins can modulate TJ expression in primary brain microvascular endothelial cells (BMVEC), thereby compromising BBB integrity and exacerbating HIV-1 neuropathogenesis. We investigated the effect of morphine and/or tat on the expression of TJ proteins ZO-1, JAM-2, Occludin and P-glycoprotein and the functional effects of TJ modulation in BMVEC. Morphine and/or tat, via the activation of pro-inflammatory cytokines, intracellular Ca(2+) release, and activation of myosin light chain kinase, modulated TJ expression resulting in decreased transendothelial electric resistance and enhanced transendothelial migration across the BBB. These studies may lead to the development of novel anti-HIV-1 therapeutics that target specific TJ proteins, thus preventing TJ disruption in opiate using HIV-1 patients.
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Human immunodeficiency virus type 1 infection increases the in vivo capacity of peripheral monocytes to cross the blood-brain barrier into the brain and the in vivo sensitivity of the blood-brain barrier to disruption by lipopolysaccharide. J Virol 2008; 82:7591-600. [PMID: 18508884 DOI: 10.1128/jvi.00768-08] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Human immunodeficiency virus type 1 (HIV-1), introduced into the brain by HIV-1-infected monocytes which migrate across the blood-brain barrier (BBB), infects resident macrophages and microglia and initiates a process that causes HIV-1-associated neurocognitive disorders. The mechanism by which HIV-1 infection circumvents the BBB-restricted passage of systemic leukocytes into the brain and disrupts the integrity of the BBB is not known. Circulating lipopolysaccharide (LPS), which can compromise the integrity of the BBB, is significantly increased in HIV-1-infected individuals. We hypothesized that HIV-1 infection increases monocyte capacity to migrate across the BBB, which is further facilitated by a compromise of BBB integrity mediated by the increased systemic LPS levels present in HIV-1-infected individuals. To investigate this possibility, we examined the in vivo BBB migration of monocytes derived from our novel mouse model, JR-CSF/EYFP mice, which are transgenic for both a long terminal repeat-regulated full-length infectious HIV-1 provirus and ROSA-26-regulated enhanced yellow fluorescent protein. We demonstrated that JR-CSF/EYFP mouse monocytes displayed an increased capacity to enter the brain by crossing either an intact BBB or a BBB whose integrity was partially compromised by systemic LPS. We also demonstrated that the JR-CSF mouse BBB was more susceptible to disruption by systemic LPS than the control wild-type mouse BBB. These results demonstrated that HIV-1 infection increased the ability of monocytes to enter the brain and increased the sensitivity of the BBB to disruption by systemic LPS, which is elevated in HIV-1-infected individuals. These mice represent a new in vivo system for studying the mechanism by which HIV-1-infected monocytes migrate into the brain.
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Mahajan SD, Aalinkeel R, Sykes DE, Reynolds JL, Bindukumar B, Adal A, Qi M, Toh J, Xu G, Prasad PN, Schwartz SA. Methamphetamine alters blood brain barrier permeability via the modulation of tight junction expression: Implication for HIV-1 neuropathogenesis in the context of drug abuse. Brain Res 2008; 1203:133-48. [PMID: 18329007 DOI: 10.1016/j.brainres.2008.01.093] [Citation(s) in RCA: 91] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2007] [Revised: 01/29/2008] [Accepted: 01/30/2008] [Indexed: 10/22/2022]
Abstract
The pathogenesis of human immunodeficiency virus (HIV) associated encephalopathy is attributed to infiltration of the central nervous system (CNS) by HIV-1 infected mononuclear cells that transmigrate across the blood brain barrier (BBB). The endothelial tight junctions (TJ) of the blood brain barrier (BBB) play a critical role in controlling cellular traffic into the CNS. Neuropathogenesis of HIV-1 is exacerbated by drugs of abuse such as methamphetamine (Meth) which are capable of dysregulating BBB function. HIV-1 viral proteins like gp120 are both neurotoxic and cytotoxic and have been implicated in the development of HIV-1 dementia (HAD). We hypothesize that gp120 in synergy with Meth can alter BBB permeability via the modulation of tight junction expression. We investigated the effect of Meth and/or gp120 on the basal expression of TJ proteins ZO-1, JAM-2, Occludin, Claudin-3 and Claudin-5, using in vitro cultures of the primary brain microvascular endothelial cells (BMVEC). Further, the functional effects of TJ modulation were assessed using an in vitro BBB model, that allowed measurement of BBB permeability using TEER measurements and transendothelial migration of immunocompetent cells. Our results show that both Meth and gp120 individually and in combination, modulated TJ expression, and these effects involved Rho-A activation. Further, both Meth and gp120 alone and in combination significantly decreased transendothelial resistance across the in vitro BBB and the enhanced transendothelial migration of immunocompetent cells across the BBB. An understanding of the mechanisms of BBB breakdown that lead to neurotoxicity is crucial to the development of therapeutic modalities for Meth abusing HAD patients.
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Affiliation(s)
- Supriya D Mahajan
- Department of Medicine, Division of Allergy, Immunology, and Rheumatology, 301 Multi Research Building, Buffalo General Hospital, 100 High Street, Buffalo, NY 14203, USA.
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Lipopolysaccharide-enhanced transcellular transport of HIV-1 across the blood-brain barrier is mediated by the p38 mitogen-activated protein kinase pathway. Exp Neurol 2008; 210:740-9. [PMID: 18295207 DOI: 10.1016/j.expneurol.2007.12.028] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2007] [Revised: 12/12/2007] [Accepted: 12/29/2007] [Indexed: 11/21/2022]
Abstract
Chronic systemic inflammation in the late stage of human immunodeficiency virus type-1 (HIV-1) infection could increase neuroinvasion of infected monocytes and cell-free virus, causing an aggravation of neurological disorders in AIDS patients. We previously showed that the peripheral administration of lipopolysaccharide (LPS) enhanced the uptake across the blood-brain barrier (BBB) of the HIV-1 viral protein gp120. Brain microvessel endothelial cells are targets of LPS. Here, we investigated whether the direct interaction between LPS and the BBB also affected HIV-1 transport using primary mouse brain microvessel endothelial cells (BMECs). LPS produced a dose (1-100 microg/mL)- and time (0.5-4 h)-dependent increase in HIV-1 transport and a decrease in transendothelial electrical resistance (TEER). Whereas indomethacin (cyclooxygenase inhibitor) and L-NAME (NO synthase inhibitor) did not affect the LPS-induced changes in HIV-1 transport or TEER, pentoxifylline (TNF-alpha inhibitor) attenuated the decrease in TEER induced by LPS, but not the LPS-induced increase in HIV-1 transport. LPS also increased the phosphorylation of p44/42 MAPK and p38 MAPK but not that of JNK. U0126 (p44/42 MAPK inhibitor) and SP600125 (JNK inhibitor) did not inhibit the LPS-induced increase in HIV-1 transport although U0126 attenuated the reduction in TEER. SB203580 (p38 MAPK inhibitor) inhibited the LPS-induced increase in HIV-1 transport without affecting TEER. Thus, LPS-enhanced HIV-1 transport is independent of changes in TEER and so is attributed to increased transcellular trafficking of HIV-1 across the BBB. These results show that LPS increases HIV-1 transcellular transport across the BBB by a pathway that is mediated by p38 MAPK phosphorylation in BMECs.
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Khan NA, Di Cello F, Stins M, Kim KS. Gp120-mediated cytotoxicity of human brain microvascular endothelial cells is dependent on p38 mitogen-activated protein kinase activation. J Neurovirol 2007; 13:242-51. [PMID: 17613714 DOI: 10.1080/13550280701286531] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Breakdown of the blood-brain barrier has been shown to contribute to neurological disorders that are prevalent in human immunodeficiency virus type 1 (HIV-1)-infected individuals, but the mechanisms involved in HIV-1-associated blood-brain barrier dysfunction remain incompletely understood. Using human brain microvascular endothelial cells (HBMECs) that constitute the blood-brain barrier, the authors determined the cytotoxic effects of gp120 on HBMECs. The authors showed that gp120 induced cytotoxicity of HBMECs derived from children, which required cotreatment with interferon (IFN)-gamma. IFN-gamma treatment exhibited up-regulation of the chemokine receptors CCR3 and CCR5 in children's HBMECs. In contrast, HBMECs isolated from adults were not responsive to gp120-mediated cytotoxicity. Peptides of gp120 representing binding regions for CD4 and chemokine receptors as well as CD4 antibody inhibited gp120-mediated cytotoxicity of HBMECs. RANTES, as expected, inhibited M-tropic gp120-mediated HBMEC cytotoxicity, whereas stromal cell-derived factor (SDF)-1alpha failed to inhibit T-tropic gp120-mediated cytotoxicity. Of interest, gp120 peptides representing non-CD4/non-chemokine receptor binding regions inhibited gp120-mediated HBMEC cytotoxicity. In addition, the authors showed that gp120-mediated HBMEC cytotoxicity involved p38 mitogen-activated protein kinase pathway. Taken together, these findings showed that gp120, in the presence of IFN-gamma, can cause dysfunction of the blood-brain barrier endothelium via MAPK pathways involving several gp120-HBMEC interactions.
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Affiliation(s)
- Naveed Ahmed Khan
- Division of Pediatric Infectious Diseases, Johns Hopkins University School of Medicine, Baltimore, Maryland 21287, USA
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36
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Abstract
The specialized cerebral microvascular endothelium interacts with the cellular milieu of the brain and extracellular matrix to form a neurovascular unit, one aspect of which is a regulated interface between the blood and central nervous system (CNS). The concept of this blood-brain barrier (BBB) as a dynamically regulated system rather than a static barrier has wide-ranging implications for pathophysiology of the CNS. While in vitro models of the BBB are useful for screening drugs targeted to the CNS and indispensable for studies of cerebral endothelial cell biology, the complex interactions of the neurovascular unit make animal-based models and methods essential tools for understanding the pathophysiology of the BBB. BBB dysfunction is a complication of neurodegenerative disease and brain injury. Studies on animal models have shown that diseases of the periphery, such as diabetes and inflammatory pain, have deleterious effects on the BBB which may contribute to neurological complications associated with these conditions. Furthermore, genetic and/or epigenetic abnormalities in constituents of the BBB may be significant contributing factors in disease etiology. Research that approaches the BBB as a dynamic system integrated with both the CNS and the periphery is therefore critical to understanding and treating diseases of the CNS. Herein, we review various methodological approaches used to study BBB function in the context of disease. These include measurement of transport between blood and brain, imaging-based technologies, and genomic/proteomic approaches.
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Witt KA, Davis TP. CNS drug delivery: opioid peptides and the blood-brain barrier. AAPS JOURNAL 2006; 8:E76-88. [PMID: 16584136 PMCID: PMC2751425 DOI: 10.1208/aapsj080109] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Peptides are key regulators in cellular and intercellular physiological responses and possess enormous promise for the treatment of pathological conditions. Opioid peptide activity within the central nervous system (CNS) is of particular interest for the treatment of pain owing to the elevated potency of peptides and the centrally mediated actions of pain processes. Despite this potential, peptides have seen limited use as clinically viable drugs for the treatment of pain. Reasons for the limited use are primarily based in the physiochemical and biochemical nature of peptides. Numerous approaches have been devised in an attempt to improve peptide drug delivery to the brain, with variable results. This review describes different approaches to peptide design/modification and provides examples of the value of these strategies to CNS delivery of peptide drugs. The various modes of modification of therapeutic peptides may be amalgamated, creating more efficacious "hybrid" peptides, with synergistic delivery to the CNS. The ongoing development of these strategies provides promise that peptide drugs may be useful for the treatment of pain and other neurologically-based disease states in the future.
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Affiliation(s)
- Ken A. Witt
- />Pharmaceutical Sciences, School of Pharmacy, Southern Illinois University, Edwardsville, 200 University Park Drive, 62026 Edwardsville, IL. USA
| | - Thomas P. Davis
- />Department of Medical Pharmacology, College of Medicine, The University of Arizona, LSN 542, 1501 N. Campbell Avenue, P.O. Box 245050, 85724 Tucson, Arizona
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Abstract
Since identification of the human immunodeficiency virus-1 (HIV-1), numerous studies suggest a link between neurological impairments, in particular dementia, with acquired immunodeficiency syndrome (AIDS) with alarming occurrence worldwide. Approximately, 60% of HIV-infected people show some form of neurological impairment, and neuropathological changes are found in 90% of autopsied cases. Approximately 30% of untreated HIV-infected persons may develop dementia. The mechanisms behind these pathological changes are still not understood. Mounting data obtained by in vivo and in vitro experiments suggest that neuronal apoptosis is a major feature of HIV associated dementia (HAD), which can occur in the absence of direct infection of neurons. The major pathway of neuronal apoptosis occurs indirectly through release of neurotoxins by activated cells in the central nervous system (CNS) involving the induction of excitotoxicity and oxidative stress. In addition a direct mechanism induced by viral proteins in the pathogenesis of HAD may also play a role. This review focuses on the molecular mechanisms of HIV-associated dementia and possible therapeutic strategies.
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Affiliation(s)
- Hakan Ozdener
- Monell Chemical Senses Center, 3500 Market Street, Philadelphia, PA 19104, USA.
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Banks WA, Kumar VB, Franko MW, Bess JW, Arthur LO. Evidence that the species barrier of human immunodeficiency virus-1 does not extend to uptake by the blood--brain barrier: comparison of mouse and human brain microvessels. Life Sci 2005; 77:2361-8. [PMID: 15946698 DOI: 10.1016/j.lfs.2004.11.041] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2004] [Accepted: 11/17/2004] [Indexed: 11/15/2022]
Abstract
HIV-1 within the CNS produces a neuroAIDS syndrome and may act as a reservoir for reinfection of the peripheral tissues. Study of how HIV-1 crosses the blood-brain barrier (BBB) has been hampered by the lack of nonprimate animal models. However, BBB transport of HIV-1 does not involve any of the known steps conferring species specificity, including binding to CD4 receptors. In vivo and in vitro studies show that HIV-1 and its glycoprotein coat, gp120, are taken up and transported across the BBB of the mouse. Here, we compared the ability of gp120 and HIV-1 to be taken up by isolated brain microvessels (IBM) freshly isolated from mice, from post-mortem human brain, and from mice that had been treated in a manner analogous to the human material (mouse post-mortem). Freshly isolated mouse IBM took up more gp120 and HIV-1 than the human or mouse post-mortem cells. We found no difference between the ability of mouse post-mortem and human IBM to take up either gp120 or HIV-1. Wheatgerm agglutinin has been previously shown to stimulate gp120 and HIV-1 uptake by the BBB; here, it stimulated the uptake of gp120 and of HIV-1 by both mouse post-mortem and human IBM, although stimulated uptake was greatest for fresh mouse IBM. These results show that the mouse can be used to study the initial phases of HIV-1 uptake by the BBB.
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Affiliation(s)
- William A Banks
- GRECC, Veterans Affairs Medical Center--St. Louis and Saint Louis University School of Medicine, Division of Geriatrics, Department of Internal Medicine, St. Louis, MO 63106, USA.
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Abstract
In recent years, there have been several important advancements in the development of neuropeptide therapeutics. Nevertheless, the targeting of peptide drugs to the CNS remains a formidable obstacle. Delivery of peptide drugs is limited by their poor bioavailability to the brain due to low metabolic stability, high clearance by the liver, and the presence of the blood brain barrier (BBB). Multiple strategies have been devised in an attempt to improve peptide drug delivery to the brain, with variable results. In this review, we discuss several of the strategies that have been used to improve both bioavailability and BBB transport, with an emphasis on antibody based vector delivery, useful for large peptides/small proteins, and glycosylation, useful for small peptides. Further development of these delivery methods may finally enable peptide drugs to be useful for the treatment of neurological disease states.
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Affiliation(s)
- Richard D Egleton
- Department of Medical Pharmacology, University of Arizona College of Medicine, Tucson, Arizona 85724, USA.
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Nakaoke R, Ryerse JS, Niwa M, Banks WA. Human immunodeficiency virus type 1 transport across the in vitro mouse brain endothelial cell monolayer. Exp Neurol 2005; 193:101-9. [PMID: 15817268 DOI: 10.1016/j.expneurol.2004.11.020] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2004] [Accepted: 11/16/2004] [Indexed: 11/29/2022]
Abstract
Human immunodeficiency virus type 1 (HIV-1) is associated with a neuroinflammatory dementia. Cognitive impairment remains a common complication of late-stage HIV-1 infection. Previous studies have shown that entry of HIV-1 into the central nervous system (CNS) occurs soon after infection. For these reasons, it is important to understand how HIV-1 crosses the BBB. We used primary mouse brain microvessel endothelial cell (MBEC) monolayer models to study interactions between brain endothelial cells and radioactively labeled HIV-1 CL4 (131I-HIV-1), which had been rendered noninfectious with aldithiol, and compared to radioactively labeled bovine serum albumin (131I-BSA or 125I-BSA) and detected HIV-1 on MBEC monolayer with electron microscopic analysis. The permeability of the monolayers to HIV-1 was measured by determining the percent material transported (PMT). Luminal to abluminal PMT of 131I-HIV-1 was 4.65 times greater than that of the much smaller 131I-BSA, showing that the MBEC monolayer is more permeable to HIV-1 than to BSA. Electron microscopy showed that HIV-1 was transported through a trans-cellular pathway from luminal side to basolateral space with some virus associated with the nucleus. Unlabeled HIV-1 did not affect the transport of 131I-HIV-1 or break down the MBEC monolayer. Wheatgerm agglutinin (WGA) increased 131I-HIV-1 penetration across the MBEC monolayer, consistent with absorptive endocytosis as the mechanism for HIV-1 penetration. The enhanced transport of HIV-1 was unidirectional, as the abluminal to luminal PMT of 131I-HIV-1 was not different from that of BSA nor enhanced by WGA. Characterization of the radioactivity transported from the luminal to abluminal chamber on Sepharose 4B-200 columns showed the transported radioactivity represented intact virus. MBEC monolayers preloaded from the luminal surface with 131I-HIV-1 showed most of the virus was retained by the endothelial cells, while the remainder was effluxed mainly to the luminal surface. MBEC monolayers preloaded from the abluminal surface with 131I-HIV-1 retained little virus and most of the virus was effluxed mainly to the abluminal surface. In conclusion, cell-free, intact 131I-HIV-1 crossed brain endothelial cell monolayers unidirectionally in the luminal to abluminal direction through an adsorptive endocytotic pathway. HIV-1 taken up from luminal side by monolayers of brain endothelial cells was mainly released to the luminal side. HIV-1 efflux mechanisms are different from influx mechanisms.
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Affiliation(s)
- Ryota Nakaoke
- Geriatric Research, Educational, and Clinical Center, Veterans Affairs Medical Center, St. Louis, MO 63106, USA
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Banks WA, Robinson SM, Nath A. Permeability of the blood–brain barrier to HIV-1 Tat. Exp Neurol 2005; 193:218-27. [PMID: 15817280 DOI: 10.1016/j.expneurol.2004.11.019] [Citation(s) in RCA: 122] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2004] [Revised: 11/09/2004] [Accepted: 11/16/2004] [Indexed: 11/28/2022]
Abstract
Infection with human immunodeficiency virus-1 (HIV-1) is associated with dysfunctions of the central nervous system (CNS). HIV-1 induces its effects on the CNS by a variety of mechanisms, including by shedding the neurotoxic viral proteins such as gp120 and Tat. Both HIV-1 and gp120 have been shown to cross the blood-brain barrier (BBB). It is has not been determined, however, whether blood-borne Tat can cross the BBB. Here, we found that Tat crosses the BBB by a nonsaturable mechanism with a unidirectional influx rate of about 0.490 microl/g/min. About 0.126% of an intravenous dose of Tat enters each g of brain. Radioactively labeled albumin injected simultaneously did not cross the BBB. The hypothalamus, occipital cortex, and hippocampus were the regions of the brain most permeable to Tat. Nonsaturable brain-to-blood efflux also occurred, most likely with reabsorption into the blood of the cerebrospinal fluid. In conclusion, we found that Tat crossed the BBB bidirectionally. Such permeability could provide a mechanism by which Tat produced on one side of the BBB could affect neural or immune function on the other side.
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Affiliation(s)
- William A Banks
- Division of Geriatrics, Department of Internal Medicine, GRECC, Veterans Affairs Medical Center-St. Louis and Saint Louis University School of Medicine, 915 N. Grand Boulevard, St. Louis, MO 63106, USA.
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Nakaoke R, Banks WA. In vitro methods in the study of viral and prion permeability across the blood-brain barrier. Cell Mol Neurobiol 2005; 25:171-80. [PMID: 15966106 DOI: 10.1007/s10571-004-1381-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
(1) Infectious agents capable of entering the central nervous system (CNS) produce some of the most dreaded diseases known to man. The infectious agent within the CNS is often protected by the blood-brain barrier (BBB), shielded from endogenous and exogenous anti-infectious agents. (2) The use of in vitro methods offers many advantages to the study of how infectious agents interact with the BBB. Two such agents which negotiate the BBB early in the course of disease before damage to the BBB are the autoimmune deficiency syndrome virus, or human immunodeficiency virus 1, and scrapie prion. Our laboratories have used in vitro methods to study these agents. (3) Here, we review some of the results form our laboratories and those of others.
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Affiliation(s)
- Ryota Nakaoke
- Department of Pharmacology 1, Nagasaki University School of Medicine, Nagasaki, Japan
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Egleton RD, Davis TP. Development of neuropeptide drugs that cross the blood-brain barrier. Neurotherapeutics 2005. [DOI: 10.1007/bf03206641] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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Banks WA, Robinson SM, Wolf KM, Bess JW, Arthur LO. Binding, internalization, and membrane incorporation of human immunodeficiency virus-1 at the blood-brain barrier is differentially regulated. Neuroscience 2004; 128:143-53. [PMID: 15450361 DOI: 10.1016/j.neuroscience.2004.06.021] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/23/2004] [Indexed: 11/24/2022]
Abstract
Human immunodeficiency virus (HIV)-1 within the CNS induces neuro-acquired immunodeficiency syndrome and acts as a reservoir for reinfection of peripheral tissues. HIV-1 crosses the blood-brain barrier (BBB) within infected immune cells and as cell-free virus by a CD4-independent mechanism. Which proteins control free virus transport across the BBB are unknown, but work with wheatgerm agglutinin (WGA) and heparin suggests that heparan sulfate proteoglycans, sialic acid, and N-acetyl-beta-D-glucosaminyl acid bind HIV-1. Here, we found that an HIV-1 T-tropic virus was taken up by mouse brain endothelial cells in vitro and crossed the BBB in vivo and could be effluxed as intact virus. Uptake was stimulated by WGA and protamine sulfate (PS) and inhibited by heparin. BBB uptake of virus involved four distinguishable binding sites: i) reversible cell surface binding involving gp120 and sensitive to PS/heparin but insensitive to WGA; internalization with a ii) WGA-sensitive site binding gp120 and iii) a PS/heparin-sensitive site not involving gp120; iv) membrane incorporation not affected by WGA, heparin, or PS. In conclusion, binding, internalization, and membrane incorporation are separately regulated steps likely determining whether HIV-1 is incorporated into brain endothelial cells, transported across them, or returned to the circulation.
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Affiliation(s)
- W A Banks
- GRECC, Veterans Affairs Medical Center-St. Louis and St. Louis University School of Medicine, Division of Geriatrics, Department of Internal Medicine, St. Louis, MO 63106, USA.
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Moroo I, Ujiie M, Walker BL, Tiong JWC, Vitalis TZ, Karkan D, Gabathuler R, Moise AR, Jefferies WA. Identification of a novel route of iron transcytosis across the mammalian blood-brain barrier. Microcirculation 2004; 10:457-62. [PMID: 14745458 DOI: 10.1038/sj.mn.7800213] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2002] [Accepted: 01/19/2003] [Indexed: 11/09/2022]
Abstract
OBJECTIVE This study was undertaken to assess the role of p97 (also known as melanotransferrin) in the transfer of iron into the brain, because the passage of most large molecules is limited by the presence of the blood-brain barrier, including that of the serum iron transporter transferrin. METHODS To study the function of the soluble form of p97, we followed the uptake of radioiodinated and 55Fe loaded p97 and transferrin by the brain during a 24-hour period. RESULTS We show that the soluble form of p97 has the ability to transcytose across the murine blood-brain barrier, and its transcytosis can be inhibited in a specific manner. We also provide evidence that p97 transports iron into the brain more efficiently than transferrin. CONCLUSIONS These data support the idea that p97 is an important iron transporter across the blood-brain barrier in normal physiology and possibly in neurodegenerative diseases, such as Alzheimer disease, in which iron homeostasis in the brain becomes disrupted.
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Affiliation(s)
- Iku Moroo
- Biotechnology Laboratory, University of British Columbia, Vancouver, Canada
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Ahr B, Robert-Hebmann V, Devaux C, Biard-Piechaczyk M. Apoptosis of uninfected cells induced by HIV envelope glycoproteins. Retrovirology 2004; 1:12. [PMID: 15214962 PMCID: PMC446229 DOI: 10.1186/1742-4690-1-12] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2004] [Accepted: 06/23/2004] [Indexed: 02/02/2023] Open
Abstract
Apoptosis, or programmed cell death, is a key event in biologic homeostasis but is also involved in the pathogenesis of many human diseases including human immunodeficiency virus (HIV) infection. Although multiple mechanisms contribute to the gradual T cell decline that occurs in HIV-infected patients, programmed cell death of uninfected bystander T lymphocytes, including CD4+ and CD8+ T cells, is an important event leading to immunodeficiency. The HIV envelope glycoproteins (Env) play a crucial role in transducing this apoptotic signal after binding to its receptors, the CD4 molecule and a coreceptor, essentially CCR5 and CXCR4. Depending on Env presentation, the receptor involved and the complexity of target cell contact, apoptosis induction is related to death receptor and/or mitochondria-dependent pathways. This review summarizes current knowledge of Env-mediated cell death leading to T cell depletion and clinical complications and covers the sometimes conflicting studies that address the possible mechanisms of T cell death.
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Affiliation(s)
- Barbara Ahr
- Laboratoire Infections Rétrovirales et Signalisation Cellulaire, CNRS UMR 5121-UM1, Institut de Biologie, 4, Bd Henri IV, CS 89508, 34960 Montpellier Cedex 2, France
| | - Véronique Robert-Hebmann
- Laboratoire Infections Rétrovirales et Signalisation Cellulaire, CNRS UMR 5121-UM1, Institut de Biologie, 4, Bd Henri IV, CS 89508, 34960 Montpellier Cedex 2, France
| | - Christian Devaux
- Laboratoire Infections Rétrovirales et Signalisation Cellulaire, CNRS UMR 5121-UM1, Institut de Biologie, 4, Bd Henri IV, CS 89508, 34960 Montpellier Cedex 2, France
| | - Martine Biard-Piechaczyk
- Laboratoire Infections Rétrovirales et Signalisation Cellulaire, CNRS UMR 5121-UM1, Institut de Biologie, 4, Bd Henri IV, CS 89508, 34960 Montpellier Cedex 2, France
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Banks WA, Niehoff ML, Adessi C, Soto C. Passage of murine scrapie prion protein across the mouse vascular blood–brain barrier. Biochem Biophys Res Commun 2004; 318:125-30. [PMID: 15110762 DOI: 10.1016/j.bbrc.2004.04.009] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2004] [Indexed: 10/26/2022]
Abstract
Prions are the infectious agents associated with transmissible spongiform encephalopathies and are composed mainly of a misfolded form of the endogenous prion protein. Prion protein must enter the brain to produce disease. Previous work has emphasized various mechanisms which partially bypass the blood-brain barrier (BBB). Here, we used the brain perfusion method to directly assess the ability of mouse scrapie protein (PrP(SC)) to cross the mouse BBB independent of the influences of neural pathways or circulating immune cells. We found that PrP(SC) oligomers rapidly crossed the BBB without disrupting it with a unidirectional influx rate of about 4.4microl/g-min. HPLC and capillary depletion confirmed that PrP(SC) crossed the entire width of the capillary wall to enter brain parenchyma. PrP(SC) also entered the cerebrospinal fluid (CSF) compartment. These results show that a prion protein can cross the intact BBB to enter both the parenchymal and CSF compartments of the brain.
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Affiliation(s)
- William A Banks
- GRECC, Veterans Affairs Medical Center-St. Louis and Division of Geriatrics, Department of Internal Medicine, Saint Louis University School of Medicine, 915 N. Grand Blvd., St. Louis, MO 63106, USA.
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Khan NA, Di Cello F, Nath A, Kim KS. Human immunodeficiency virus type 1 tat-mediated cytotoxicity of human brain microvascular endothelial cells. J Neurovirol 2004; 9:584-93. [PMID: 14602571 DOI: 10.1080/13550280390218760] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/30/2022]
Abstract
Human immunodeficiency virus (HIV)-1 infection is often complicated with neurologic disorders, but the pathogenesis of HIV-1 encephalopathy is incompletely understood. Tat (HIV-1 transactivator protein) is released from HIV-1-infected cells and has been detected in the sera and cerebrospinal fluid of HIV-1-infected patients. Tat, along with increased inflammatory cytokines such as interferon-gamma (IFN-gamma), have been implicated in the pathogenesis of HIV-1-associated blood-brain barrier dysfunction. The present study examined the effects of Tat and IFN-gamma on human brain microvascular endothelial cells (HBMECs), which constitute the blood-brain barrier. Tat produced cytotoxicity of HBMECs, but required IFN-gamma. IFN-gamma treatment of HBMECs up-regulates vascular endothelial growth factor receptor-2 (VEGFR2/KDR), which is known to be the receptor for Tat. Tat activated KDR in the presence of IFN-gamma, and Tat-mediated cytopathic changes involve its interaction with KDR and phosphatidylinositol 3-kinase (PI3K). Further understanding and characterization of Tat-HBMEC interactions should help us understand HIV-1 neuropathogenesis and develop strategies to prevent HIV-1 encephalopathy.
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Affiliation(s)
- Naveed Ahmed Khan
- Division of Pediatric Infectious Diseases, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
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Stins MF, Pearce D, Di Cello F, Erdreich-Epstein A, Pardo CA, Sik Kim K. Induction of intercellular adhesion molecule-1 on human brain endothelial cells by HIV-1 gp120: role of CD4 and chemokine coreceptors. J Transl Med 2003; 83:1787-98. [PMID: 14691297 DOI: 10.1097/01.lab.0000107008.13321.c8] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
Central nervous system dysfunction is commonly observed in children with HIV-1 infection, but the mechanisms whereby HIV-1 causes encephalopathy are not completely understood. We have previously shown that human brain microvascular endothelial cells (HBMEC) from children are responsive to gp120 derived from X4 HIV-1 by increasing expression of intercellular adhesion molecule (ICAM)-1 and vascular cell adhesion molecule-1. However, the mechanisms involved in gp120-mediated up-regulation of cell adhesion molecule expression is unclear. In the present study, we found that gp120 derived from both X4 and R5 HIV-1 induced increased expression of ICAM-1 on HBMEC, but the degree of this up-regulation differed among the various HBMEC isolates. The up-regulation of ICAM-1 was inhibited by anti-CD4 antibodies as well as by specific antibodies directed against chemokine receptors and small-molecule coreceptor inhibitors. Anti-CD4 antibodies inhibited the increase in ICAM-1 expression mediated by gp120 derived from X4 and R5 HIV-1, whereas antibodies against chemokine receptors displayed a differential inhibition depending on the source of gp120. Both X4 and R5 gp120-induced ICAM-1 expression was sensitive to pertussis toxin and involved the nuclear factor-kB pathway. These findings indicate a direct involvement of CD4 and a differential involvement of chemokine receptors in the activation of pediatric HBMEC by X4 and R5 gp120. The activation of brain endothelium of children by HIV-1 protein gp120 by way of CD4 and chemokine receptors may have implications for the pathogenesis of HIV-1 encephalopathy in the pediatric population.
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Affiliation(s)
- Monique F Stins
- Department of Pediatrics, Johns Hopkins School of Medicine, Baltimore, Maryland 21205, USA.
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