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Le Guennec L, Weiss N. Blood-brain barrier dysfunction in intensive care unit. JOURNAL OF INTENSIVE MEDICINE 2023; 3:303-312. [PMID: 38028637 PMCID: PMC10658046 DOI: 10.1016/j.jointm.2023.01.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/18/2022] [Revised: 01/04/2023] [Accepted: 01/05/2023] [Indexed: 12/01/2023]
Abstract
The central nervous system is characterized by a peculiar vascularization termed blood-brain barrier (BBB), which regulates the exchange of cells and molecules between the cerebral tissue and the whole body. BBB dysfunction is a life-threatening condition since its presence corresponds to a marker of severity in most diseases encountered in the intensive care unit (ICU). During critical illness, inflammatory response, cytokine release, and other phenomena activating the brain endothelium contribute to alterations in the BBB and increase its permeability to solutes, cells, nutrients, and xenobiotics. Moreover, patients in the ICU are often old, with underlying acute or chronic diseases, and overly medicated due to their critical condition; these factors could also contribute to the development of BBB dysfunction. An accurate diagnostic approach is critical for the identification of the mechanisms underlying BBB alterations, which should be rapidly managed by intensivists. Several methods were developed to investigate the BBB and assess its permeability. Nevertheless, in humans, exploration of the BBB requires the use of indirect methods. Imaging and biochemical methods can be used to study the abnormal passage of molecules through the BBB. In this review, we describe the structural and functional characteristics of the BBB, present tools and methods for probing this interface, and provide examples of the main diseases managed in the ICU that are related to BBB dysfunction.
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Affiliation(s)
- Loic Le Guennec
- Département de neurologie, Sorbonne Université, AP-HP Sorbonne Université, Hôpital de la Pitié-Salpêtrière, Unité de Médecine Intensive Réanimation àorientation neurologique, Paris 75013, France
- Groupe de Recherche Clinique en REanimation et Soins intensifs du Patient en Insuffisance Respiratoire aiguE (GRC-RESPIRE) Sorbonne Université, Paris 75013, France
| | - Nicolas Weiss
- Département de neurologie, Sorbonne Université, AP-HP Sorbonne Université, Hôpital de la Pitié-Salpêtrière, Unité de Médecine Intensive Réanimation àorientation neurologique, Paris 75013, France
- Groupe de Recherche Clinique en REanimation et Soins intensifs du Patient en Insuffisance Respiratoire aiguE (GRC-RESPIRE) Sorbonne Université, Paris 75013, France
- Brain Liver Pitié-Salpêtrière (BLIPS) Study Group, INSERM UMR_S 938, Centre de recherche Saint-Antoine, Maladies métaboliques, Biliaires et fibro-inflammatoire du foie, Institute of Cardiometabolism and Nutrition (ICAN), Paris 75013, France
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2
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Ma C, Wolfinger R. A prediction model for blood-brain barrier penetrating peptides based on masked peptide transformers with dynamic routing. Brief Bioinform 2023; 24:bbad399. [PMID: 37985456 DOI: 10.1093/bib/bbad399] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2023] [Revised: 09/26/2023] [Accepted: 10/17/2023] [Indexed: 11/22/2023] Open
Abstract
Blood-brain barrier penetrating peptides (BBBPs) are short peptide sequences that possess the ability to traverse the selective blood-brain interface, making them valuable drug candidates or carriers for various payloads. However, the in vivo or in vitro validation of BBBPs is resource-intensive and time-consuming, driving the need for accurate in silico prediction methods. Unfortunately, the scarcity of experimentally validated BBBPs hinders the efficacy of current machine-learning approaches in generating reliable predictions. In this paper, we present DeepB3P3, a novel framework for BBBPs prediction. Our contribution encompasses four key aspects. Firstly, we propose a novel deep learning model consisting of a transformer encoder layer, a convolutional network backbone, and a capsule network classification head. This integrated architecture effectively learns representative features from peptide sequences. Secondly, we introduce masked peptides as a powerful data augmentation technique to compensate for small training set sizes in BBBP prediction. Thirdly, we develop a novel threshold-tuning method to handle imbalanced data by approximating the optimal decision threshold using the training set. Lastly, DeepB3P3 provides an accurate estimation of the uncertainty level associated with each prediction. Through extensive experiments, we demonstrate that DeepB3P3 achieves state-of-the-art accuracy of up to 98.31% on a benchmarking dataset, solidifying its potential as a promising computational tool for the prediction and discovery of BBBPs.
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Affiliation(s)
- Chunwei Ma
- JMP Statistical Discovery, LLC, Cary, 27513, NC, USA
- Department of Computer Science and Engineering, University at Buffalo, Buffalo, 14260, NY, USA
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3
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Hughes A, Khan DS, Alkins R. Current and Emerging Systems for Focused Ultrasound-Mediated Blood-Brain Barrier Opening. ULTRASOUND IN MEDICINE & BIOLOGY 2023; 49:1479-1490. [PMID: 37100672 DOI: 10.1016/j.ultrasmedbio.2023.02.017] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Revised: 02/09/2023] [Accepted: 02/23/2023] [Indexed: 05/17/2023]
Abstract
With an ever-growing list of neurological applications of focused ultrasound (FUS), there has been a consequent increase in the variety of systems for delivering ultrasound energy to the brain. Specifically, recent successful pilot clinical trials of blood-brain barrier (BBB) opening with FUS have generated substantial interest in the future applications of this relatively novel therapy, with divergent, purpose-built technologies emerging. With many of these technologies at various stages of pre-clinical and clinical investigation, this article seeks to provide an overview and analysis of the numerous medical devices in active use and under development for FUS-mediated BBB opening.
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Affiliation(s)
- Alec Hughes
- School of Medicine, Faculty of Health Sciences, Queen's University, Kingston, ON, Canada
| | - Dure S Khan
- Centre for Neuroscience Studies, Queen's University, Kingston, ON, Canada
| | - Ryan Alkins
- Centre for Neuroscience Studies, Queen's University, Kingston, ON, Canada; Division of Neurosurgery, Department of Surgery, Kingston Health Sciences Centre, Queen's University, Kingston, ON, Canada.
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4
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The Blood–Brain Barrier—A Key Player in Multiple Sclerosis Disease Mechanisms. Biomolecules 2022; 12:biom12040538. [PMID: 35454127 PMCID: PMC9025898 DOI: 10.3390/biom12040538] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Revised: 03/28/2022] [Accepted: 03/30/2022] [Indexed: 02/07/2023] Open
Abstract
Over the past decade, multiple sclerosis (MS), a chronic neuroinflammatory disease with severe personal and social consequences, has undergone a steady increase in incidence and prevalence rates worldwide. Despite ongoing research and the development of several novel therapies, MS pathology remains incompletely understood, and the prospect for a curative treatment continues to be unpromising in the near future. A sustained research effort, however, should contribute to a deeper understanding of underlying disease mechanisms, which will undoubtedly yield improved results in drug development. In recent years, the blood–brain barrier (BBB) has increasingly become the focus of many studies as it appears to be involved in both MS disease onset and progression. More specifically, neurovascular unit damage is believed to be involved in the critical process of CNS immune cell penetration, which subsequently favors the development of a CNS-specific immune response, leading to the classical pathological and clinical hallmarks of MS. The aim of the current narrative review is to merge the relevant evidence on the role of the BBB in MS pathology in a comprehensive and succinct manner. Firstly, the physiological structure and functions of the BBB as a component of the more complex neurovascular unit are presented. Subsequently, the authors review the specific alteration of the BBB encountered in different stages of MS, focusing on both the modifications of BBB cells in neuroinflammation and the CNS penetration of immune cells. Finally, the currently accepted theories on neurodegeneration in MS are summarized.
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5
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Murata Y, Neuhoff S, Rostami-Hodjegan A, Takita H, Al-Majdoub ZM, Ogungbenro K. In Vitro to In Vivo Extrapolation Linked to Physiologically Based Pharmacokinetic Models for Assessing the Brain Drug Disposition. AAPS J 2022; 24:28. [PMID: 35028763 PMCID: PMC8817058 DOI: 10.1208/s12248-021-00675-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Accepted: 12/09/2021] [Indexed: 11/30/2022] Open
Abstract
Drug development for the central nervous system (CNS) is a complex endeavour with low success rates, as the structural complexity of the brain and specifically the blood-brain barrier (BBB) poses tremendous challenges. Several in vitro brain systems have been evaluated, but the ultimate use of these data in terms of translation to human brain concentration profiles remains to be fully developed. Thus, linking up in vitro-to-in vivo extrapolation (IVIVE) strategies to physiologically based pharmacokinetic (PBPK) models of brain is a useful effort that allows better prediction of drug concentrations in CNS components. Such models may overcome some known aspects of inter-species differences in CNS drug disposition. Required physiological (i.e. systems) parameters in the model are derived from quantitative values in each organ. However, due to the inability to directly measure brain concentrations in humans, compound-specific (drug) parameters are often obtained from in silico or in vitro studies. Such data are translated through IVIVE which could be also applied to preclinical in vivo observations. In such exercises, the limitations of the assays and inter-species differences should be adequately understood in order to verify these predictions with the observed concentration data. This report summarizes the state of IVIVE-PBPK-linked models and discusses shortcomings and areas of further research for better prediction of CNS drug disposition. Graphical abstract ![]()
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Affiliation(s)
- Yukiko Murata
- Centre for Applied Pharmacokinetic Research, Division of Pharmacy and Optometry, University of Manchester, Manchester, M13 9PT, UK.,Sohyaku.Innovative Research Division, Mitsubishi Tanabe Pharma Corporation, 1000, Kamoshida-cho, Aoba-ku, Yokohama, Kanagawa, 227-0033, Japan
| | - Sibylle Neuhoff
- Certara UK Ltd, Simcyp Division, 1 Concourse Way, Level 2-Acero, Sheffield, S1 2BJ, UK
| | - Amin Rostami-Hodjegan
- Centre for Applied Pharmacokinetic Research, Division of Pharmacy and Optometry, University of Manchester, Manchester, M13 9PT, UK.,Certara UK Ltd, Simcyp Division, 1 Concourse Way, Level 2-Acero, Sheffield, S1 2BJ, UK
| | - Hiroyuki Takita
- Centre for Applied Pharmacokinetic Research, Division of Pharmacy and Optometry, University of Manchester, Manchester, M13 9PT, UK.,Development Planning, Clinical Development Center, Asahi Kasei Pharma Corporation, Hibiya Mitsui Tower, 1-1-2 Yurakucho, Chiyoda-ku, Tokyo, 100-0006, Japan
| | - Zubida M Al-Majdoub
- Centre for Applied Pharmacokinetic Research, Division of Pharmacy and Optometry, University of Manchester, Manchester, M13 9PT, UK
| | - Kayode Ogungbenro
- Centre for Applied Pharmacokinetic Research, Division of Pharmacy and Optometry, University of Manchester, Manchester, M13 9PT, UK.
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6
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Hanafy AS, Dietrich D, Fricker G, Lamprecht A. Blood-brain barrier models: Rationale for selection. Adv Drug Deliv Rev 2021; 176:113859. [PMID: 34246710 DOI: 10.1016/j.addr.2021.113859] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2021] [Revised: 06/21/2021] [Accepted: 07/01/2021] [Indexed: 01/21/2023]
Abstract
Brain delivery is a broad research area, the outcomes of which are far hindered by the limited permeability of the blood-brain barrier (BBB). Over the last century, research has been revealing the BBB complexity and the crosstalk between its cellular and molecular components. Pathologically, BBB alterations may precede as well as be concomitant or lead to brain diseases. To simulate the BBB and investigate options for drug delivery, several in vitro, in vivo, ex vivo, in situ and in silico models are used. Hundreds of drug delivery vehicles successfully pass preclinical trials but fail in clinical settings. Inadequate selection of BBB models is believed to remarkably impact the data reliability leading to unsatisfactory results in clinical trials. In this review, we suggest a rationale for BBB model selection with respect to the addressed research question and downstream applications. The essential considerations of an optimal BBB model are discussed.
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Affiliation(s)
- Amira Sayed Hanafy
- Department of Pharmaceutics, Institute of Pharmacy, University of Bonn, Bonn, Germany; Department of Pharmaceutics and Pharmaceutical Technology, Faculty of Pharmacy, Pharos University in Alexandria, Alexandria, Egypt
| | - Dirk Dietrich
- Department of Neurosurgery, University Hospital Bonn, Bonn, Germany
| | - Gert Fricker
- Institute of Pharmacy and Molecular Biotechnology, Ruprecht-Karls University, Heidelberg, Germany
| | - Alf Lamprecht
- Department of Pharmaceutics, Institute of Pharmacy, University of Bonn, Bonn, Germany.
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7
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B3Pred: A Random-Forest-Based Method for Predicting and Designing Blood-Brain Barrier Penetrating Peptides. Pharmaceutics 2021; 13:pharmaceutics13081237. [PMID: 34452198 PMCID: PMC8399279 DOI: 10.3390/pharmaceutics13081237] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Revised: 07/07/2021] [Accepted: 07/14/2021] [Indexed: 12/14/2022] Open
Abstract
The blood–brain barrier is a major obstacle in treating brain-related disorders, as it does not allow the delivery of drugs into the brain. We developed a method for predicting blood–brain barrier penetrating peptides to facilitate drug delivery into the brain. These blood–brain barrier penetrating peptides (B3PPs) can act as therapeutics, as well as drug delivery agents. We trained, tested, and evaluated our models on blood–brain barrier peptides obtained from the B3Pdb database. First, we computed a wide range of peptide features. Then, we selected relevant peptide features. Finally, we developed numerous machine-learning-based models for predicting blood–brain barrier peptides using the selected features. The random-forest-based model performed the best with respect to the top 80 selected features and achieved a maximal 85.08% accuracy with an AUROC of 0.93. We also developed a webserver, B3pred, that implements our best models. It has three major modules that allow users to predict/design B3PPs and scan B3PPs in a protein sequence.
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8
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Chowdhury EA, Noorani B, Alqahtani F, Bhalerao A, Raut S, Sivandzade F, Cucullo L. Understanding the brain uptake and permeability of small molecules through the BBB: A technical overview. J Cereb Blood Flow Metab 2021; 41:1797-1820. [PMID: 33444097 PMCID: PMC8327119 DOI: 10.1177/0271678x20985946] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
The brain is the most important organ in our body requiring its unique microenvironment. By the virtue of its function, the blood-brain barrier poses a significant hurdle in drug delivery for the treatment of neurological diseases. There are also different theories regarding how molecules are typically effluxed from the brain. In this review, we comprehensively discuss how the different pharmacokinetic techniques used for measuring brain uptake/permeability of small molecules have evolved with time. We also discuss the advantages and disadvantages associated with these different techniques as well as the importance to utilize the right method to properly assess CNS exposure to drug molecules. Even though very strong advances have been made we still have a long way to go to ensure a reduction in failures in central nervous system drug development programs.
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Affiliation(s)
- Ekram Ahmed Chowdhury
- Department of Pharmaceutical Sciences, Texas Tech University Health Sciences Center, Amarillo, USA
| | - Behnam Noorani
- Department of Pharmaceutical Sciences, Texas Tech University Health Sciences Center, Amarillo, USA
| | - Faleh Alqahtani
- Department of Pharmacology and Toxicology, College of Pharmacy, King Saud University, Riyadh, Saudi Arabia
| | - Aditya Bhalerao
- Department of Foundational Medical Studies, Oakland University William Beaumont School of Medicine, Rochester, USA
| | - Snehal Raut
- Department of Pharmaceutical Sciences, Texas Tech University Health Sciences Center, Amarillo, USA
| | - Farzane Sivandzade
- Department of Foundational Medical Studies, Oakland University William Beaumont School of Medicine, Rochester, USA
| | - Luca Cucullo
- Department of Foundational Medical Studies, Oakland University William Beaumont School of Medicine, Rochester, USA
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9
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Physiology of the cerebrovascular adaptation to pregnancy. HANDBOOK OF CLINICAL NEUROLOGY 2021. [PMID: 32736760 DOI: 10.1016/b978-0-444-64239-4.00004-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/30/2023]
Abstract
The adaptation of the cerebral circulation to pregnancy is unique compared with other organs and circulatory systems, because the brain requires relatively constant blood flow and water and solute composition to maintain homeostasis. Thus, a major adaptation of the maternal cerebrovasculature to pregnancy is to maintain normalcy in the face of expanded plasma volume, increased cardiac output, and high levels of permeability factors. In this chapter, the effect of pregnancy on critical functions of the cerebral circulation is discussed, including changes occurring at the endothelium and blood-brain barrier (BBB), which protect the maternal brain from changes in BBB permeability. Further, pregnancy-induced changes in the structure and function of cerebral arteries, arterioles, and veins will be discussed as they relate to cerebral vascular resistance, hemodynamics, and cerebral blood flow autoregulation.
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10
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Lkhagvasuren B, Mee-Inta O, Zhao ZW, Hiramoto T, Boldbaatar D, Kuo YM. Pancreas-Brain Crosstalk. Front Neuroanat 2021; 15:691777. [PMID: 34354571 PMCID: PMC8329585 DOI: 10.3389/fnana.2021.691777] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Accepted: 06/30/2021] [Indexed: 12/19/2022] Open
Abstract
The neural regulation of glucose homeostasis in normal and challenged conditions involves the modulation of pancreatic islet-cell function. Compromising the pancreas innervation causes islet autoimmunity in type 1 diabetes and islet cell dysfunction in type 2 diabetes. However, despite the richly innervated nature of the pancreas, islet innervation remains ill-defined. Here, we review the neuroanatomical and humoral basis of the cross-talk between the endocrine pancreas and autonomic and sensory neurons. Identifying the neurocircuitry and neurochemistry of the neuro-insular network would provide clues to neuromodulation-based approaches for the prevention and treatment of diabetes and obesity.
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Affiliation(s)
- Battuvshin Lkhagvasuren
- Brain Science Institute, Mongolian National University of Medical Sciences, Ulaanbaatar, Mongolia
| | - Onanong Mee-Inta
- Institute of Basic Medical Sciences, National Cheng Kung University College of Medicine, Tainan, Taiwan
| | - Zi-Wei Zhao
- Institute of Basic Medical Sciences, National Cheng Kung University College of Medicine, Tainan, Taiwan
| | - Tetsuya Hiramoto
- Department of Psychosomatic Medicine, Fukuoka Hospital, National Hospital Organization, Fukuoka, Japan
| | - Damdindorj Boldbaatar
- Brain Science Institute, Mongolian National University of Medical Sciences, Ulaanbaatar, Mongolia
| | - Yu-Min Kuo
- Institute of Basic Medical Sciences, National Cheng Kung University College of Medicine, Tainan, Taiwan.,Department of Cell Biology and Anatomy, National Cheng Kung University College of Medicine, Tainan, Taiwan
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11
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Storelli F, Anoshchenko O, Unadkat JD. Successful Prediction of Human Steady-State Unbound Brain-to-Plasma Concentration Ratio of P-gp Substrates Using the Proteomics-Informed Relative Expression Factor Approach. Clin Pharmacol Ther 2021; 110:432-442. [PMID: 33675056 PMCID: PMC8360000 DOI: 10.1002/cpt.2227] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2020] [Accepted: 01/25/2021] [Indexed: 12/31/2022]
Abstract
In order to optimize central nervous system (CNS) drug development, accurate prediction of the drug's human steady-state unbound brain interstitial fluid-to-plasma concentration ratio (Kp,uu,brain ) is critical, especially for drugs that are effluxed by the multiple drug resistance transporters (e.g., P-glycoprotein, P-gp). Due to lack of good in vitro human blood-brain barrier models, we and others have advocated the use of a proteomics-informed relative expressive factor (REF) approach to predict Kp,uu,brain . Therefore, we tested the success of this approach in humans, with a focus on P-gp substrates, using brain positron emission tomography imaging data for verification. To do so, the efflux ratio (ER) of verapamil, N-desmethyl loperamide, and metoclopramide was determined in human P-gp-transfected MDCKII cells using the Transwell assay. Then, using the ER estimate, Kp,uu,brain of the drug was predicted using REF (ER approach). Alternatively, in vitro passive and P-gp-mediated intrinsic clearances (CLs) of these drugs, estimated using a five-compartmental model, were extrapolated to in vivo using REF (active CL) and brain microvascular endothelial cells protein content (passive CL). The ER approach successfully predicted Kp,uu,brain of all three drugs within twofold of observed data and within 95% confidence interval of the observed data for verapamil and N-desmethyl loperamide. Using the in vitro-to-in vivo extrapolated clearance approach, Kp,uu,brain was reasonably well predicted but not the brain unbound interstitial fluid drug concentration-time profile. Therefore, we propose that the ER approach be used to predict Kp,uu,brain of CNS candidate drugs to enhance their success in development.
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Affiliation(s)
- Flavia Storelli
- Department of PharmaceuticsSchool of PharmacyUniversity of WashingtonSeattleWashingtonUSA
| | - Olena Anoshchenko
- Department of PharmaceuticsSchool of PharmacyUniversity of WashingtonSeattleWashingtonUSA
| | - Jashvant D. Unadkat
- Department of PharmaceuticsSchool of PharmacyUniversity of WashingtonSeattleWashingtonUSA
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12
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Khatoon R, Alam MA, Sharma PK. Current approaches and prospective drug targeting to brain. J Drug Deliv Sci Technol 2021. [DOI: 10.1016/j.jddst.2020.102098] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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13
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Kaya M, Ahishali B. Basic physiology of the blood-brain barrier in health and disease: a brief overview. Tissue Barriers 2021; 9:1840913. [PMID: 33190576 PMCID: PMC7849738 DOI: 10.1080/21688370.2020.1840913] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2020] [Revised: 10/18/2020] [Accepted: 10/19/2020] [Indexed: 12/18/2022] Open
Abstract
The blood-brain barrier (BBB), a dynamic interface between blood and brain constituted mainly by endothelial cells of brain microvessels, robustly restricts the entry of potentially harmful blood-sourced substances and cells into the brain, however, many therapeutically active agents concurrently cannot gain access into the brain at effective doses in the presence of an intact barrier. On the other hand, breakdown of BBB integrity may involve in the pathogenesis of various neurodegenerative diseases. Besides, certain diseases/disorders such as Alzheimer's disease, hypertension, and epilepsy are associated with varying degrees of BBB disruption. In this review, we aim to highlight the current knowledge on the cellular and molecular composition of the BBB with special emphasis on the major transport pathways across the barrier type endothelial cells. We further provide a discussion on the innovative brain drug delivery strategies in which the obstacle formed by BBB interferes with effective pharmacological treatment of neurodegenerative diseases/disorders.
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Affiliation(s)
- Mehmet Kaya
- Koç University School of Medicine Department of Physiology, Koç University Research Center for Translational Medicine, Istanbul, Turkey
| | - Bulent Ahishali
- Koç University School of Medicine Department of Histology and Embryology, Koç University Research Center for Translational Medicine, Istanbul, Turkey
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14
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Okada T, Suzuki H, Travis ZD, Zhang JH. The Stroke-Induced Blood-Brain Barrier Disruption: Current Progress of Inspection Technique, Mechanism, and Therapeutic Target. Curr Neuropharmacol 2020; 18:1187-1212. [PMID: 32484111 PMCID: PMC7770643 DOI: 10.2174/1570159x18666200528143301] [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: 03/31/2020] [Revised: 04/23/2020] [Accepted: 05/23/2020] [Indexed: 02/07/2023] Open
Abstract
Stroke is one of the leading causes of mortality and morbidity worldwide. The blood-brain barrier (BBB) is a characteristic structure of microvessel within the brain. Under normal physiological conditions, the BBB plays a role in the prevention of harmful substances entering into the brain parenchyma within the central nervous system. However, stroke stimuli induce the breakdown of BBB leading to the influx of cytotoxic substances, vasogenic brain edema, and hemorrhagic transformation. Therefore, BBB disruption is a major complication, which needs to be addressed in order to improve clinical outcomes in stroke. In this review, we first discuss the structure and function of the BBB. Next, we discuss the progress of the techniques utilized to study BBB breakdown in in-vitro and in-vivo studies, along with biomarkers and imaging techniques in clinical settings. Lastly, we highlight the mechanisms of stroke-induced neuroinflammation and apoptotic process of endothelial cells causing BBB breakdown, and the potential therapeutic targets to protect BBB integrity after stroke. Secondary products arising from stroke-induced tissue damage provide transformation of myeloid cells such as microglia and macrophages to pro-inflammatory phenotype followed by further BBB disruption via neuroinflammation and apoptosis of endothelial cells. In contrast, these myeloid cells are also polarized to anti-inflammatory phenotype, repairing compromised BBB. Therefore, therapeutic strategies to induce anti-inflammatory phenotypes of the myeloid cells may protect BBB in order to improve clinical outcomes of stroke patients.
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Affiliation(s)
- Takeshi Okada
- Department of Physiology and Pharmacology, Loma Linda University, Loma Linda, CA, USA, Risley Hall, Room 219,
11041 Campus St, Loma Linda, CA 92354, USA,Department of Neurosurgery, Mie University Graduate School of Medicine, Mie, Japan, 2-174 Edobashi, Tsu, Mie 514-8507, Japan
| | - Hidenori Suzuki
- Department of Neurosurgery, Mie University Graduate School of Medicine, Mie, Japan, 2-174 Edobashi, Tsu, Mie 514-8507, Japan
| | - Zachary D Travis
- Department of Physiology and Pharmacology, Loma Linda University, Loma Linda, CA, USA, Risley Hall, Room 219,
11041 Campus St, Loma Linda, CA 92354, USA,Department of Earth and Biological Sciences, Loma Linda University, Loma Linda, CA, USA , Risley Hall, Room 219, 11041 Campus St, Loma Linda, CA 92354, USA
| | - John H Zhang
- Department of Physiology and Pharmacology, Loma Linda University, Loma Linda, CA, USA, Risley Hall, Room 219,
11041 Campus St, Loma Linda, CA 92354, USA,Department of Anesthesiology, Loma Linda University, Loma Linda, CA, USA, Risley Hall, Room 219, 11041 Campus St, Loma Linda, CA 92354, USA,Department of Neurosurgery, Loma Linda University, Loma Linda, CA, USA, Risley Hall, Room 219, 11041 Campus St, Loma Linda, CA 92354, USA
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15
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Kuo CF, Majd S. An Improved in Vitro Blood-Brain Barrier Model for Applications in Therapeutics' Delivery to Brain. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2020; 2020:3331-3334. [PMID: 33018717 DOI: 10.1109/embc44109.2020.9175888] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Blood-brain barrier (BBB) imposes a major obstacle for entry of therapeutics to brain. In vitro BBB models that can provide reliable prediction of therapeutics' ability to cross BBB are thus, critical for the advancement of brain therapeutics. Towards the development of an improved BBB model, here we studied the individual and combinatorial effect of few different culture conditions on the quality of the commonly used trans-well BBB model. Specifically, we investigated how the addition of (i) astrocyte co-culture, (ii) astrocyte-conditioned media (ACM), and (iii) astrocyte co-culture along with ACM, affects the characteristics of BBB. The resultant BBB models were characterized for trans-endothelial electrical resistance (TEER), permeability, and expression of a tight-junction protein ZO-1. We found that addition of ACM and astrocytes, individually, had similar impact on BBB's TEER, increasing it by ~2 fold. Interestingly, the presence of both astrocytes and ACM had a significantly greater impact on TEER and increased it by ~3 fold. Addition of ACM, with and without astrocyte co-culture, led to a reduction in permeability of this BBB model. Moreover, addition of ACM and astrocyte co-culture, both individually and in combination, led to a noticeable increase in ZO-1 expression in the BBB endothelial cells. These findings provide a new approach for further improvement of the commonly used trans-well BBB system.
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Panaro MA, Benameur T, Porro C. Hypothalamic Neuropeptide Brain Protection: Focus on Oxytocin. J Clin Med 2020; 9:jcm9051534. [PMID: 32438751 PMCID: PMC7290962 DOI: 10.3390/jcm9051534] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2020] [Revised: 05/06/2020] [Accepted: 05/14/2020] [Indexed: 02/06/2023] Open
Abstract
Oxytocin (OXT) is hypothalamic neuropeptide synthetized in the brain by magnocellular and parvo cellular neurons of the paraventricular (PVN), supraoptic (SON) and accessory nuclei (AN) of the hypothalamus. OXT acts in the central and peripheral nervous systems via G-protein-coupled receptors. The classical physiological functions of OXT are uterine contractions, the milk ejection reflex during lactation, penile erection and sexual arousal, but recent studies have demonstrated that OXT may have anti-inflammatory and anti-oxidant properties and regulate immune and anti-inflammatory responses. In the pathogenesis of various neurodegenerative diseases, microglia are present in an active form and release high levels of pro-inflammatory cytokines and chemokines that are implicated in the process of neural injury. A promising treatment for neurodegenerative diseases involves new therapeutic approaches targeting activated microglia. Recent studies have reported that OXT exerts neuroprotective effects through the inhibition of production of pro-inflammatory mediators, and in the development of correct neural circuitry. The focus of this review is to attribute a new important role of OXT in neuroprotection through the microglia–OXT interaction of immature and adult brains. In addition, we analyzed the strategies that could enhance the delivery of OXT in the brain and amplify its positive effects.
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Affiliation(s)
- Maria Antonietta Panaro
- Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari, 70125 Bari, Italy;
| | - Tarek Benameur
- Department of Biomedical Sciences, College of Medicine, King Faisal University, 31982 Al-Ahsa, Saudi Arabia;
| | - Chiara Porro
- Department of Clinical and Experimental Medicine, University of Foggia, 71121 Foggia, Italy
- Correspondence:
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Zhang W, Zhu L, An C, Wang R, Yang L, Yu W, Li P, Gao Y. The blood brain barrier in cerebral ischemic injury – Disruption and repair. BRAIN HEMORRHAGES 2020. [DOI: 10.1016/j.hest.2019.12.004] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
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Actin-Binding Protein Cortactin Promotes Pathogenesis of Experimental Autoimmune Encephalomyelitis by Supporting Leukocyte Infiltration into the Central Nervous System. J Neurosci 2020; 40:1389-1404. [PMID: 31911458 DOI: 10.1523/jneurosci.1266-19.2019] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Revised: 12/04/2019] [Accepted: 12/19/2019] [Indexed: 01/21/2023] Open
Abstract
Leukocyte entry into the central nervous system (CNS) is essential for immune surveillance but is also the basis for the development of pathologic inflammatory conditions within the CNS, such as multiple sclerosis and its animal model, experimental autoimmune encephalomyelitis (EAE). The actin-binding protein, cortactin, in endothelial cells is an important player in regulating the interaction of immune cells with the vascular endothelium. Cortactin has been shown to control the integrity of the endothelial barrier and to support neutrophil transendothelial migration in vitro and in vivo in the skin. Here we use cortactin gene-inactivated male and female mice to study the role of this protein in EAE. Inducing EAE by immunization with a myelin oligodendrocyte glycoprotein peptide (MOG35-55) revealed an ameliorated disease course in cortactin gene-deficient female mice compared with WT mice. However, proliferation capacity and expression of IL-17A and IFNγ by cortactin-deficient and WT splenocytes did not differ, suggesting that the lack of cortactin does not affect induction of the immune response. Rather, cortactin deficiency caused decreased vascular permeability and reduced leukocyte infiltration into the brains and spinal cords of EAE mice. Accordingly, cortactin gene-deficient mice had smaller numbers of proinflammatory cuffs, less extensive demyelination, and reduced expression levels of proinflammatory cytokines within the neural tissue compared with WT littermates. Thus, cortactin contributes to the development of neural inflammation by supporting leukocyte transmigration through the blood-brain barrier and, therefore, represents a potential candidate for targeting CNS autoimmunity.SIGNIFICANCE STATEMENT Multiple sclerosis is an autoimmune neuroinflammatory disorder, based on the entry of inflammatory leukocytes into the CNS where these cells cause demyelination and neurodegeneration. Here, we use a mouse model for multiple sclerosis, experimental autoimmune encephalomyelitis, and show that gene inactivation of cortactin, an actin binding protein that modulates actin dynamics and branching, protects against neuroinflammation in experimental autoimmune encephalomyelitis. Leukocyte infiltration into the CNS was inhibited in cortactin-deficient mice, and lack of cortactin in cultured primary brain endothelial cells inhibited leukocyte transmigration. Expression levels of proinflammatory cytokines in the CNS and induction of vascular permeability were reduced. We conclude that cortactin represents a novel potential target for the treatment of multiple sclerosis.
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Le Foll C. Hypothalamic Fatty Acids and Ketone Bodies Sensing and Role of FAT/CD36 in the Regulation of Food Intake. Front Physiol 2019; 10:1036. [PMID: 31474875 PMCID: PMC6702519 DOI: 10.3389/fphys.2019.01036] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2019] [Accepted: 07/29/2019] [Indexed: 12/19/2022] Open
Abstract
The obesity and type-2 diabetes epidemic is escalating and represents one of the costliest biomedical challenges confronting modern society. Moreover, the increasing consumption of high fat food is often correlated with an increase in body mass index. In people predisposed to be obese or already obese, the impaired ability of the brain to monitor and respond to alterations in fatty acid (FA) metabolism is increasingly recognized as playing a role in the pathophysiological development of these disorders. The brain senses and regulates metabolism using highly specialized nutrient-sensing neurons located mainly in the hypothalamus. The same neurons are able to detect variation in the extracellular levels of glucose, FA and ketone bodies as a way to monitor nutrient availability and to alter its own activity. In addition, glial cells such as astrocytes create major connections to neurons and form a tight relationship to closely regulate nutrient uptake and metabolism. This review will examine the different pathways by which neurons are able to detect free fatty acids (FFA) to alter its activity and how high fat diet (HFD)-astrocytes induced ketone bodies production interplays with neuronal FA sensing. The role of HFD-induced inflammation and how FA modulate the reward system will also be investigated here.
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Affiliation(s)
- Christelle Le Foll
- Institute of Veterinary Physiology, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland
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20
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Di Marco A, Gonzalez Paz O, Fini I, Vignone D, Cellucci A, Battista MR, Auciello G, Orsatti L, Zini M, Monteagudo E, Khetarpal V, Rose M, Dominguez C, Herbst T, Toledo-Sherman L, Summa V, Muñoz-Sanjuán I. Application of an in Vitro Blood–Brain Barrier Model in the Selection of Experimental Drug Candidates for the Treatment of Huntington’s Disease. Mol Pharm 2019; 16:2069-2082. [DOI: 10.1021/acs.molpharmaceut.9b00042] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Affiliation(s)
| | | | | | | | | | | | | | | | | | | | - Vinod Khetarpal
- CHDI Management, CHDI Foundation, Center Drive Los Angeles 6080, California, United States
| | - Mark Rose
- CHDI Management, CHDI Foundation, Center Drive Los Angeles 6080, California, United States
| | - Celia Dominguez
- CHDI Management, CHDI Foundation, Center Drive Los Angeles 6080, California, United States
| | - Todd Herbst
- CHDI Management, CHDI Foundation, Center Drive Los Angeles 6080, California, United States
| | - Leticia Toledo-Sherman
- CHDI Management, CHDI Foundation, Center Drive Los Angeles 6080, California, United States
| | | | - Ignacio Muñoz-Sanjuán
- CHDI Management, CHDI Foundation, Center Drive Los Angeles 6080, California, United States
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21
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Billington S, Salphati L, Hop CECA, Chu X, Evers R, Burdette D, Rowbottom C, Lai Y, Xiao G, Humphreys WG, Nguyen TB, Prasad B, Unadkat JD. Interindividual and Regional Variability in Drug Transporter Abundance at the Human Blood-Brain Barrier Measured by Quantitative Targeted Proteomics. Clin Pharmacol Ther 2019; 106:228-237. [PMID: 30673124 DOI: 10.1002/cpt.1373] [Citation(s) in RCA: 53] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2018] [Accepted: 01/09/2019] [Indexed: 02/04/2023]
Abstract
For in vitro to in vivo extrapolation (IVIVE) of brain distribution of drugs that are transported at the human blood-brain barrier (BBB), it is important to quantify the interindividual and regional variability of drug transporter abundance at this barrier. Therefore, using quantitative targeted proteomics, we compared the abundance of adenosine triphosphate-binding cassette and solute carrier transporters in brain microvascular endothelial cells (BMECs) isolated from postmortem specimens of two matched brain regions, the occipital (Brodmann Area (BA)17) and parietal (BA39) lobe, from 30 adults. Of the quantifiable transporters, the abundance ranked: glucose transporter (GLUT)1 > breast cancer resistance protein > P-glycoprotein (P-gp) > equilibrative nucleoside transporter (ENT)1 > organic anion-transporting polypeptide (OATP)2B1. The abundance of multidrug resistance protein 1/2/3/4, OATP1A2, organic anion transporter (OAT)3, organic cation transporter (OCT)1/2, OCTN1/2, or ENT2 was below the limit of quantification. Transporter abundance per gram of tissue (scaled using GLUT1 abundance in BMEC vs. brain homogenate) in BA17 was 30-42% higher than BA39. The interindividual variability in transporter abundance (percentage of coefficient of variation (%CV)) was 35-57% (BA17) and 27-46% (BA39). These data can be used in proteomics-informed bottom-up IVIVE to predict human brain drug distribution.
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Affiliation(s)
- Sarah Billington
- Department of Pharmaceutics, University of Washington, Seattle, Washington, USA
| | - Laurent Salphati
- Drug Metabolism and Pharmacokinetics, Genentech, Inc., South San Francisco, California, USA
| | - Cornelis E C A Hop
- Drug Metabolism and Pharmacokinetics, Genentech, Inc., South San Francisco, California, USA
| | - Xiaoyan Chu
- Pharmacokinetics, Pharmacodynamics, and Drug Metabolism, Merck & Co., Kenilworth, New Jersey, USA
| | - Raymond Evers
- Pharmacokinetics, Pharmacodynamics, and Drug Metabolism, Merck & Co., Kenilworth, New Jersey, USA
| | | | | | - Yurong Lai
- Department of Drug Metabolism and Pharmacokinetics, Gilead Sciences, Inc., Foster City, California, USA
| | - Guangqing Xiao
- Department of Drug Metabolism and Pharmacokinetics, Takeda Pharmaceuticals International Co., Cambridge, Massachusetts, USA
| | | | - Tot Bui Nguyen
- Department of Pharmaceutics, University of Washington, Seattle, Washington, USA
| | - Bhagwat Prasad
- Department of Pharmaceutics, University of Washington, Seattle, Washington, USA
| | - Jashvant D Unadkat
- Department of Pharmaceutics, University of Washington, Seattle, Washington, USA
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22
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Quiñonez-Silvero C, Hübner K, Herzog W. Development of the brain vasculature and the blood-brain barrier in zebrafish. Dev Biol 2019; 457:181-190. [PMID: 30862465 DOI: 10.1016/j.ydbio.2019.03.005] [Citation(s) in RCA: 52] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2018] [Revised: 03/06/2019] [Accepted: 03/08/2019] [Indexed: 12/13/2022]
Abstract
To ensure tissue homeostasis the brain needs to be protected from blood-derived fluctuations or pathogens that could affect its function. Therefore, the brain capillaries develop tissue-specific properties to form a selective blood-brain barrier (BBB), allowing the passage of essential molecules to the brain and blocking the penetration of potentially harmful compounds or cells. Previous studies reported the presence of this barrier in zebrafish. The intrinsic features of the zebrafish embryos and larvae in combination with optical techniques, make them suitable for the study of barrier establishment and maturation. In this review, we discuss the most recent contributions to the development and formation of a functional zebrafish BBB. Moreover, we compare the molecular and cellular characteristic of the zebrafish and the mammalian BBB.
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Affiliation(s)
- Claudia Quiñonez-Silvero
- University of Muenster, Muenster, Germany; Cells-in-Motion Cluster of Excellence (EXC 1003 - CiM), University of Muenster, Germany
| | - Kathleen Hübner
- University of Muenster, Muenster, Germany; Cells-in-Motion Cluster of Excellence (EXC 1003 - CiM), University of Muenster, Germany
| | - Wiebke Herzog
- University of Muenster, Muenster, Germany; Cells-in-Motion Cluster of Excellence (EXC 1003 - CiM), University of Muenster, Germany; Max Planck Institute for Molecular Biomedicine, Muenster, Germany.
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Abstract
Treatment of certain central nervous system disorders, including different types of cerebral malignancies, is limited by traditional oral or systemic administrations of therapeutic drugs due to possible serious side effects and/or lack of the brain penetration and, therefore, the efficacy of the drugs is diminished. During the last decade, several new technologies were developed to overcome barrier properties of cerebral capillaries. This review gives a short overview of the structural elements and anatomical features of the blood–brain barrier. The various in vitro (static and dynamic), in vivo (microdialysis), and in situ (brain perfusion) blood–brain barrier models are also presented. The drug formulations and administration options to deliver molecules effectively to the central nervous system (CNS) are presented. Nanocarriers, nanoparticles (lipid, polymeric, magnetic, gold, and carbon based nanoparticles, dendrimers, etc.), viral and peptid vectors and shuttles, sonoporation and microbubbles are briefly shown. The modulation of receptors and efflux transporters in the cell membrane can also be an effective approach to enhance brain exposure to therapeutic compounds. Intranasal administration is a noninvasive delivery route to bypass the blood–brain barrier, while direct brain administration is an invasive mode to target the brain region with therapeutic drug concentrations locally. Nowadays, both technological and mechanistic tools are available to assist in overcoming the blood–brain barrier. With these techniques more effective and even safer drugs can be developed for the treatment of devastating brain disorders.
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24
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Penetration of the blood-brain barrier by peripheral neuropeptides: new approaches to enhancing transport and endogenous expression. Cell Tissue Res 2018; 375:287-293. [PMID: 30535799 DOI: 10.1007/s00441-018-2959-y] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2018] [Accepted: 11/06/2018] [Indexed: 12/15/2022]
Abstract
The blood-brain barrier (BBB) is a structural and functional barrier between the interstitial fluid of the brain and the blood; the barrier maintains the precisely controlled biochemical environment that is necessary for neural function. This constellation of endothelial cells, macrophages, pericytes, and astrocytes forms the neurovascular unit which is the structural and functional unit of the blood-brain barrier. Peptides enter and exit the CNS by transport systems expressed by the capillary endothelial cells of the neurovascular unit. Limiting the transport of peptides and proteins into the brain are efflux transporters like P-gp are transmembrane proteins present on the luminal side of the cerebral capillary endothelium and their function is to promote transit and excretion of drugs from the brain to the blood. Nanocarrier systems have been developed to exploit transport systems for enhanced BBB transport. Recent approaches for enhancing endogenous peptide expression are discussed.
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25
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Xu L, Nirwane A, Yao Y. Basement membrane and blood-brain barrier. Stroke Vasc Neurol 2018; 4:78-82. [PMID: 31338215 PMCID: PMC6613871 DOI: 10.1136/svn-2018-000198] [Citation(s) in RCA: 158] [Impact Index Per Article: 26.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2018] [Accepted: 11/16/2018] [Indexed: 12/24/2022] Open
Abstract
The blood–brain barrier (BBB) is a highly complex and dynamic structure, mainly composed of brain microvascular endothelial cells, pericytes, astrocytes and the basement membrane (BM). The vast majority of BBB research focuses on its cellular constituents. Its non-cellular component, the BM, on the other hand, is largely understudied due to its intrinsic complexity and the lack of research tools. In this review, we focus on the role of the BM in BBB integrity. We first briefly introduce the biochemical composition and structure of the BM. Next, the biological functions of major components of the BM in BBB formation and maintenance are discussed. Our goal is to provide a concise overview on how the BM contributes to BBB integrity.
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Affiliation(s)
- Lingling Xu
- Department of Pharmaceutical and Biomedical Sciences, University of Georgia, Athens, Georgia, USA
| | - Abhijit Nirwane
- Department of Pharmaceutical and Biomedical Sciences, University of Georgia, Athens, Georgia, USA
| | - Yao Yao
- Department of Pharmaceutical and Biomedical Sciences, University of Georgia, Athens, Georgia, USA
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26
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Yang C, Hawkins KE, Doré S, Candelario-Jalil E. Neuroinflammatory mechanisms of blood-brain barrier damage in ischemic stroke. Am J Physiol Cell Physiol 2018; 316:C135-C153. [PMID: 30379577 DOI: 10.1152/ajpcell.00136.2018] [Citation(s) in RCA: 430] [Impact Index Per Article: 71.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
As part of the neurovascular unit, the blood-brain barrier (BBB) is a unique, dynamic regulatory boundary that limits and regulates the exchange of molecules, ions, and cells between the blood and the central nervous system. Disruption of the BBB plays an important role in the development of neurological dysfunction in ischemic stroke. Blood-borne substances and cells have restricted access to the brain due to the presence of tight junctions between the endothelial cells of the BBB. Following stroke, there is loss of BBB tight junction integrity, leading to increased paracellular permeability, which results in vasogenic edema, hemorrhagic transformation, and increased mortality. Thus, understanding principal mediators and molecular mechanisms involved in BBB disruption is critical for the development of novel therapeutics to treat ischemic stroke. This review discusses the current knowledge of how neuroinflammation contributes to BBB damage in ischemic stroke. Specifically, we provide an updated overview of the role of cytokines, chemokines, oxidative and nitrosative stress, adhesion molecules, matrix metalloproteinases, and vascular endothelial growth factor as well as the role of different cell types in the regulation of BBB permeability in ischemic stroke.
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Affiliation(s)
- Changjun Yang
- Department of Neuroscience, McKnight Brain Institute, University of Florida , Gainesville, Florida
| | - Kimberly E Hawkins
- Department of Neuroscience, McKnight Brain Institute, University of Florida , Gainesville, Florida
| | - Sylvain Doré
- Department of Neuroscience, McKnight Brain Institute, University of Florida , Gainesville, Florida.,Departments of Anesthesiology, Neurology, Psychiatry, Psychology, and Pharmaceutics, McKnight Brain Institute, University of Florida , Gainesville, Florida
| | - Eduardo Candelario-Jalil
- Department of Neuroscience, McKnight Brain Institute, University of Florida , Gainesville, Florida
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27
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Magdoom KN, Delgado F, Bohórquez AC, Brown AC, Carney PR, Rinaldi C, Mareci TH, Ewing JR, Sarntinoranont M. Longitudinal evaluation of tumor microenvironment in rat focal brainstem glioma using diffusion and perfusion MRI. J Magn Reson Imaging 2018; 49:1322-1332. [PMID: 30318760 DOI: 10.1002/jmri.26315] [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: 01/06/2018] [Revised: 08/09/2018] [Accepted: 08/10/2018] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Brainstem gliomas are aggressive and difficult to treat. Growth of these tumors may be characterized with MRI methods. PURPOSE To visualize longitudinal changes in tumor volume, vascular leakiness, and tissue microstructure in an animal model of brainstem glioma. STUDY TYPE Prospective animal model. ANIMAL MODEL Male Sprague-Dawley rats (n = 9) were imaged with 9L gliosarcoma cells infused into the pontine reticular formation of the brainstem. The MRI tumor microenvironment was studied at 3 and 10 days postimplantation of tumor cells. FIELD STRENGTH/SEQUENCE Diffusion tensor imaging (DTI) and dynamic contrast-enhanced (DCE)-MRI were performed at 4.7T using spin-echo multislice echo planar imaging and gradient echo multislice imaging, respectively. ASSESSMENT Tumor leakiness was assessed by the forward volumetric transfer constant, Ktrans , estimated from DCE-MRI data. Tumor structure was evaluated with fractional anisotropy (FA) obtained from DTI. Tumor volumes, delineated by a T1 map, T2 -weighted image, FA, and DCE signal enhancement were compared. STATISTICAL TESTS Changes in the assessed parameters within and across the groups (ie, rats 3 and 10 days post tumor cell implantation) were evaluated with Wilcoxon rank-sum tests. RESULTS Day 3 tumors were visible mainly on contrast-enhanced images, while day 10 tumors were visible in both contrast-enhanced and diffusion-weighted images. Mean Ktrans at day 10 was 41% lower than at day 3 (P = 0.23). In day 10 tumors, FA was regionally lower in the tumor compared to normal tissue (P = 0.0004), and tumor volume, segmented based on FA map, was significantly smaller (P ≤ 0.05) than that obtained from other contrasts. DATA CONCLUSION Contrast-enhanced MRI was found to be more sensitive in detecting early-stage tumor boundaries than other contrasts. Areas of the tumor outlined by DCE-MRI and DTI were significantly different. Over the observed period of tumor growth, average vessel leakiness decreased with tumor progression. LEVEL OF EVIDENCE 2 Technical Efficacy: Stage 3 J. Magn. Reson. Imaging 2019;49:1322-1332.
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Affiliation(s)
- Kulam Najmudeen Magdoom
- Department of Mechanical and Aerospace Engineering, University of Florida, Gainesville, Florida, USA
| | - Francisco Delgado
- J. Crayton Pruitt Family Department of Biomedical Engineering, Gainesville, Florida, USA
| | - Ana C Bohórquez
- J. Crayton Pruitt Family Department of Biomedical Engineering, Gainesville, Florida, USA
| | - Alec C Brown
- Department of Biochemistry and Molecular Biology, University of Florida, Gainesville, Florida, USA
| | - Paul R Carney
- Department of Neurology and Neuroscience Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Carlos Rinaldi
- J. Crayton Pruitt Family Department of Biomedical Engineering, Gainesville, Florida, USA.,Department of Chemical Engineering University of Florida, Gainesville, Florida, USA
| | - Thomas H Mareci
- J. Crayton Pruitt Family Department of Biomedical Engineering, Gainesville, Florida, USA.,Department of Biochemistry and Molecular Biology, University of Florida, Gainesville, Florida, USA
| | - James R Ewing
- Department of Neurology, Henry Ford Hospital, Detroit, Michigan, USA
| | - Malisa Sarntinoranont
- Department of Mechanical and Aerospace Engineering, University of Florida, Gainesville, Florida, USA.,J. Crayton Pruitt Family Department of Biomedical Engineering, Gainesville, Florida, USA
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Ni W, Chen W, Lu Y. Emerging findings into molecular mechanism of brain metastasis. Cancer Med 2018; 7:3820-3833. [PMID: 29992751 PMCID: PMC6089171 DOI: 10.1002/cam4.1667] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2018] [Revised: 05/26/2018] [Accepted: 06/16/2018] [Indexed: 12/29/2022] Open
Abstract
Brain metastasis is an important cause of morbidity and mortality in cancer patients. Hence, the need to develop improved therapies to prevent and treat metastasis to the brain is becoming urgent. Recent studies in this area are bringing about some advanced progress on brain metastasis. It was concluded that the occurrence and poor prognosis of brain metastasis have been mostly attributed to the exclusion of anticancer drugs from the brain by the blood-brain barrier. And several highly potent new generation targeted drugs with enhanced CNS distribution have been developed constantly. However, the noted "seed and soil" hypothesis also suggests that the outcome of metastasis depends on the relationship between unique tumor cells and the specific organ microenvironment. Moreover, increasing studies in multiple tumor types demonstrated that brain metastasis has great molecular differences between primary tumors and extracranial metastasis to a large extent. Here, the authors summarized the most common malignancies that could lead to brain metastasis-lung cancer, breast cancer and melanoma and their related mutated factors. Only by comprehending a deeper understanding of the molecular mechanisms, more effective brain-specific therapies will be developed for brain metastasis.
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Affiliation(s)
- Wenting Ni
- Jiangsu Key Laboratory for Pharmacology and Safety Evaluation of Chinese Materia MedicaSchool of PharmacyNanjing University of Chinese MedicineNanjingChina
| | - Wenxing Chen
- Jiangsu Key Laboratory for Pharmacology and Safety Evaluation of Chinese Materia MedicaSchool of PharmacyNanjing University of Chinese MedicineNanjingChina
- Jiangsu Collaborative Innovation Center of Traditional Chinese Medicine (TCM) Prevention and Treatment of TumorNanjingChina
| | - Yin Lu
- Jiangsu Key Laboratory for Pharmacology and Safety Evaluation of Chinese Materia MedicaSchool of PharmacyNanjing University of Chinese MedicineNanjingChina
- Jiangsu Collaborative Innovation Center of Traditional Chinese Medicine (TCM) Prevention and Treatment of TumorNanjingChina
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29
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Johnson AC, Hammer ES, Sakkaki S, Tremble SM, Holmes GL, Cipolla MJ. Inhibition of blood-brain barrier efflux transporters promotes seizure in pregnant rats: Role of circulating factors. Brain Behav Immun 2018; 67:13-23. [PMID: 28739514 PMCID: PMC5696046 DOI: 10.1016/j.bbi.2017.07.017] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/02/2017] [Revised: 07/18/2017] [Accepted: 07/20/2017] [Indexed: 11/17/2022] Open
Abstract
Seizure-provoking factors circulate late in gestation during normal pregnancy, but do not readily gain access to the brain due to the protective nature of the blood-brain barrier. In particular, efflux transporters are powerful ATP-driven pumps that actively prevent unwanted compounds from entering the brain. We hypothesized that acute inhibition of efflux transporters at the blood-brain barrier would result in spontaneous seizures in pregnant rats. We further hypothesized that the blood-brain barrier protects the maternal brain from seizure by increasing expression and/or activity of p-glycoprotein (P-gp), a major efflux transporter. Main blood-brain barrier efflux transporters were inhibited in-vivo in nonpregnant (Nonpreg) and pregnant (Preg; d19) Sprague Dawley rats (n=8/group). Seizures were monitored in conscious animals for 8h via chronically implanted electroencephalography (EEG) electrodes in the hippocampus and motor cortex and time-synced video. P-gp activity was measured via a calcein accumulation assay in freshly isolated cortical and hippocampal capillaries from Preg (d20) and Nonpreg rats (n=8-16/group), to assess regional susceptibility to transporter inhibition. P-gp expression, capillary density, and microglial activation as a measure of neuroinflammation were quantified using immunohistochemistry (n=4-6/group). Efflux transporter inhibition elicited hippocampal seizures within 1h in 100% of Preg rats that was not associated with neuroinflammation or elevated tumor necrosis factor alpha (TNFα) or vascular endothelial growth factor (VEGF), but negatively correlated with levels of estradiol. Hippocampal seizures were considerably less prevalent in Nonpreg rats. However, behavioral seizures in the motor cortex developed of similar severity in both groups of rats, demonstrating regional heterogeneity in response to efflux transporter inhibition. Basal P-gp activity was similar between groups, however, exposure to serum from Preg rats significantly decreased P-gp activity in the hippocampus, but not cortex, compared to serum from Nonpreg rats (0.29±0.1units/s in Preg vs. 0.06±0.02units/s in Nonpreg rats; p<0.05) that was not associated with elevated TNFα or VEGF. Thus, pregnancy differentially increased the susceptibility of the hippocampus to seizures in response to blood-brain barrier efflux transporter inhibition that may be due to the inhibitory effect of circulating factors in pregnancy on P-gp activity in the hippocampus.
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Affiliation(s)
- Abbie C Johnson
- Department of Neurological Sciences, University of Vermont Larner College of Medicine, Burlington, VT 05405, USA.
| | - Erica S Hammer
- Department of Obstetrics, Gynecology, and Reproductive Sciences, University of Vermont Larner College of Medicine, Burlington, VT 05405, USA.
| | - Sophie Sakkaki
- Department of Neurological Sciences, University of Vermont Larner College of Medicine, Burlington, VT 05405, USA.
| | - Sarah M Tremble
- Department of Neurological Sciences, University of Vermont Larner College of Medicine, Burlington, VT 05405, USA.
| | - Gregory L Holmes
- Department of Neurological Sciences, University of Vermont Larner College of Medicine, Burlington, VT 05405, USA.
| | - Marilyn J Cipolla
- Department of Neurological Sciences, University of Vermont Larner College of Medicine, Burlington, VT 05405, USA; Department of Obstetrics, Gynecology, and Reproductive Sciences, University of Vermont Larner College of Medicine, Burlington, VT 05405, USA; Department of Pharmacology, University of Vermont Larner College of Medicine, Burlington, VT 05405, USA.
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Desai BS, Monahan AJ, Carvey PM, Hendey B. Blood–Brain Barrier Pathology in Alzheimer's and Parkinson's Disease: Implications for Drug Therapy. Cell Transplant 2017; 16:285-99. [PMID: 17503739 DOI: 10.3727/000000007783464731] [Citation(s) in RCA: 215] [Impact Index Per Article: 30.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
The blood–brain barrier (BBB) is a tightly regulated barrier in the central nervous system. Though the BBB is thought to be intact during neurodegenerative diseases such as Alzheimer's (AD) and Parkinson's disease (PD), recent evidence argues otherwise. Dysfunction of the BBB may be involved in disease progression, eliciting of peripheral immune response, and, most importantly, altered drug efficacy. In this review, we will give a brief overview of the BBB, its components, and their functions. We will critically evaluate the current literature in AD and PD BBB pathology resulting from insult, neuroinflammation, and neurodegeneration. Specifically, we will discuss alterations in tight junction, transport and endothelial cell surface proteins, and vascular density changes, all of which result in altered permeability. Finally, we will discuss the implications of BBB dysfunction in current and future therapeutics. Developing a better appreciation of BBB dysfunction in AD and PD may not only provide novel strategies in treatment, but will prove an interesting milestone in understanding neurodegenerative disease etiology and progression.
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Affiliation(s)
- Brinda S Desai
- Department of Pharmacology, Rush University Medical Center, Chicago, IL 60612, USA.
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McInerney MP, Short JL, Nicolazzo JA. Neurovascular Alterations in Alzheimer's Disease: Transporter Expression Profiles and CNS Drug Access. AAPS JOURNAL 2017; 19:940-956. [PMID: 28462473 DOI: 10.1208/s12248-017-0077-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/26/2017] [Accepted: 03/15/2017] [Indexed: 01/05/2023]
Abstract
Despite a century of steady and incremental progress toward understanding the underlying biochemical mechanisms, Alzheimer's disease (AD) remains a complicated and enigmatic disease, and greater insight will be necessary before substantive clinical success is realised. Over the last decade in particular, a large body of work has highlighted the cerebral microvasculature as an anatomical region with an increasingly apparent role in the pathogenesis of AD. The causative interplay and temporal cascade that manifest between the brain vasculature and the wider disease progression of AD are not yet fully understood, and further inquiry is required to properly characterise these relationships. The purpose of this review is to highlight the recent advancements in research implicating neurovascular factors in AD, at both the molecular and anatomical levels. We begin with a brief introduction of the biochemical and genetic aspects of AD, before reviewing the essential concepts of the blood-brain barrier (BBB) and the neurovascular unit (NVU). In detail, we then examine the evidence demonstrating involvement of BBB dysfunction in AD pathogenesis, highlighting the importance of neurovascular components in AD. Lastly, we include within this review research that focuses on how altered properties of the BBB in AD impact upon CNS exposure of therapeutic agents and the potential clinical impact that this may have on people with this disease.
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Affiliation(s)
- Mitchell P McInerney
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, VIC, 3052, Australia
| | - Jennifer L Short
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, 3052, VIC, Australia
| | - Joseph A Nicolazzo
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, VIC, 3052, Australia.
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Pikor NB, Cupovic J, Onder L, Gommerman JL, Ludewig B. Stromal Cell Niches in the Inflamed Central Nervous System. THE JOURNAL OF IMMUNOLOGY 2017; 198:1775-1781. [DOI: 10.4049/jimmunol.1601566] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/07/2016] [Accepted: 10/19/2016] [Indexed: 11/19/2022]
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Erdő F, Denes L, de Lange E. Age-associated physiological and pathological changes at the blood-brain barrier: A review. J Cereb Blood Flow Metab 2017; 37:4-24. [PMID: 27837191 PMCID: PMC5363756 DOI: 10.1177/0271678x16679420] [Citation(s) in RCA: 279] [Impact Index Per Article: 39.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/21/2016] [Revised: 10/21/2016] [Accepted: 10/24/2016] [Indexed: 12/13/2022]
Abstract
The age-associated decline of the neurological and cognitive functions becomes more and more serious challenge for the developed countries with the increasing number of aged populations. The morphological and biochemical changes in the aging brain are the subjects of many extended research projects worldwide for a long time. However, the crucial role of the blood-brain barrier (BBB) impairment and disruption in the pathological processes in age-associated neurodegenerative disorders received special attention just for a few years. This article gives an overview on the major elements of the blood-brain barrier and its supporting mechanisms and also on their alterations during development, physiological aging process and age-associated neurodegenerative disorders (Alzheimer's disease, multiple sclerosis, Parkinson's disease, pharmacoresistant epilepsy). Besides the morphological alterations of the cellular elements (endothelial cells, astrocytes, pericytes, microglia, neuronal elements) of the BBB and neurovascular unit, the changes of the barrier at molecular level (tight junction proteins, adheres junction proteins, membrane transporters, basal lamina, extracellular matrix) are also summarized. The recognition of new players and initiators of the process of neurodegeneration at the level of the BBB may offer new avenues for novel therapeutic approaches for the treatment of numerous chronic neurodegenerative disorders currently without effective medication.
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Affiliation(s)
- Franciska Erdő
- Faculty of Information Technology and Bionics, Pázmány Péter Catholic University, Budapest, Hungary
| | - László Denes
- Institute of Pharmacology & Pharmacotherapy, Semmelweis University, Budapest, Hungary
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Nagata K, Yamazaki T, Takano D, Maeda T, Fujimaki Y, Nakase T, Sato Y. Cerebral circulation in aging. Ageing Res Rev 2016; 30:49-60. [PMID: 27484894 DOI: 10.1016/j.arr.2016.06.001] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2016] [Revised: 05/31/2016] [Accepted: 06/01/2016] [Indexed: 12/20/2022]
Abstract
Cerebral circulation is known to be protected by the regulatory function against the hypoperfusion that will affect the cognitive function as a result of brain ischemia and energy failure. The regulatory function includes cerebrovascular autoregulation, chemical control, metabolic control, and neurogenic control, and those compensatory mechanisms can be influenced by hypertension, atherosclerosis, cardiac diseases, cerebrovascular diseases and aging. On the other hand, large and/or small infarction, intracranial hemorrhage, subarachnoid hemorrhage, atherosclerosis, amylod angiopathy are also more directly associated with cognitive decline not only in those with vascular cognitive impairment or vascular dementia but also those with Alzheimer's disease.
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Affiliation(s)
- Ken Nagata
- Department of Neurology, Clinical Research Institute, Yokohama General Hospital, Yokohama, Japan.
| | - Takashi Yamazaki
- Department of Neurology, Clinical Research Institute, Yokohama General Hospital, Yokohama, Japan
| | - Daiki Takano
- Department of Neurology, Clinical Research Institute, Yokohama General Hospital, Yokohama, Japan
| | - Tetsuya Maeda
- Department of Neurology and Gerontology, Iwate Medical University, Morioka, Japan
| | - Yumi Fujimaki
- Department of Neurology, Research Institute for Brain and Blood Vessels, Akita, Japan
| | - Taizen Nakase
- Department of Neurology, Research Institute for Brain and Blood Vessels, Akita, Japan
| | - Yuichi Sato
- Department of Neurology, Noshiro Yamamoto Medical Association Hospital, Noshiro, Japan
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Abstract
Many patients with lung cancer, breast cancer, and melanoma develop brain metastases that are resistant to conventional therapy. The median survival for untreated patients is 1 to 2 months, which may be extended to 6 months with surgery, radiotherapy, and chemotherapy. The outcome of metastasis depends on multiple interactions of unique metastatic cells with host homeostatic mechanisms which the tumor cells exploit for their survival and proliferation. The blood-brain barrier is leaky in metastases that are larger than 0.5-mm diameter because of production of vascular endothelial growth factor by metastatic cells. Brain metastases are surrounded and infiltrated by microglia and activated astrocytes. The interaction with astrocytes leads to up-regulation of multiple genes in the metastatic cells, including several survival genes that are responsible for the increased resistance of tumor cells to cytotoxic drugs. These findings substantiate the importance of the "seed and soil" hypothesis and that successful treatment of brain metastases must include targeting of the organ microenvironment.
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36
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Burgess A, Hynynen K. Microbubble-Assisted Ultrasound for Drug Delivery in the Brain and Central Nervous System. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2016; 880:293-308. [PMID: 26486344 DOI: 10.1007/978-3-319-22536-4_16] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The blood-brain barrier is a serious impediment to the delivery of pharmaceutical treatments for brain diseases, including cancer, neurodegenerative and neuropsychatric diseases. Focused ultrasound, when combined with microbubbles, has emerged as an effective method to transiently and locally open the blood-brain barrier to promote drug delivery to the brain. Focused ultrasound has been used to successfully deliver a wide variety of therapeutic agents to pre-clinical disease models. The requirement for clinical translation of focused ultrasound technology is considered.
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Affiliation(s)
- Alison Burgess
- Physical Sciences, Sunnybrook Research Institute, Toronto, ON, Canada
| | - Kullervo Hynynen
- Physical Sciences, Sunnybrook Research Institute, Toronto, ON, Canada. .,Medical Biophysics, University of Toronto, Toronto, ON, Canada.
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37
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Potential of Neural Stem Cell-Based Therapy for Parkinson's Disease. PARKINSONS DISEASE 2015; 2015:571475. [PMID: 26664823 PMCID: PMC4664819 DOI: 10.1155/2015/571475] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/25/2015] [Accepted: 11/03/2015] [Indexed: 12/14/2022]
Abstract
Neural stem cell (NSC) transplantation is an emerging strategy for restoring neuronal function in neurological disorders, such as Parkinson's disease (PD), which is characterized by a profound and selective loss of nigrostriatal dopaminergic (DA) neurons. Adult neurogenesis generates newborn neurons that can be observed at specialized niches where endothelial cells (ECs) play a significant role in regulating the behavior of NSCs, including self-renewal and differentiating into all neural lineage cells. In this minireview, we highlight the importance of establishing an appropriate microenvironment at the target site of NSC transplantation, where grafted cells integrate into the surroundings in order to enhance DA neurotransmission. Using a novel model of NSC-EC coculture, it is possible to combine ECs with NSCs, to generate such a neurovascular microenvironment. With appropriate NSCs selected, the composition of the transplant can be investigated through paracrine and juxtacrine signaling within the neurovascular unit (NVU). With target site cellular and acellular compartments of the microenvironment recognized, guided DA differentiation of NSCs can be achieved. As differentiated DA neurons integrate into the existing nigrostriatal DA pathway, the symptoms of PD can potentially be alleviated by reversing characteristic neurodegeneration.
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38
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Johnson AC, Cipolla MJ. The cerebral circulation during pregnancy: adapting to preserve normalcy. Physiology (Bethesda) 2015; 30:139-47. [PMID: 25729059 DOI: 10.1152/physiol.00048.2014] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
The adaptation of the brain and cerebral circulation to pregnancy are unique compared with other organs and circulatory systems, ultimately functioning to maintain brain homeostasis. In this review, the effect of pregnancy on critical functions of the cerebral circulation is discussed, including changes occurring at the endothelium and blood-brain barrier, and changes in the structure and function of cerebral arteries and arterioles, hemodynamics, and cerebral blood flow autoregulation.
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Affiliation(s)
- Abbie C Johnson
- Department of Neurological Sciences, University of Vermont College of Medicine, Burlington, Vermont
| | - Marilyn J Cipolla
- Department of Neurological Sciences, University of Vermont College of Medicine, Burlington, Vermont
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39
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Blood–Brain Barrier Permeability and Brain Uptake Mechanism of Kainic Acid and Dihydrokainic Acid. Neurochem Res 2014; 40:542-9. [DOI: 10.1007/s11064-014-1499-4] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2014] [Revised: 12/02/2014] [Accepted: 12/02/2014] [Indexed: 01/09/2023]
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40
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Sanchez-Covarrubias L, Slosky LM, Thompson BJ, Davis TP, Ronaldson PT. Transporters at CNS barrier sites: obstacles or opportunities for drug delivery? Curr Pharm Des 2014; 20:1422-49. [PMID: 23789948 DOI: 10.2174/13816128113199990463] [Citation(s) in RCA: 154] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2013] [Accepted: 06/18/2013] [Indexed: 01/11/2023]
Abstract
The blood-brain barrier (BBB) and blood-cerebrospinal fluid (BCSF) barriers are critical determinants of CNS homeostasis. Additionally, the BBB and BCSF barriers are formidable obstacles to effective CNS drug delivery. These brain barrier sites express putative influx and efflux transporters that precisely control permeation of circulating solutes including drugs. The study of transporters has enabled a shift away from "brute force" approaches to delivering drugs by physically circumventing brain barriers towards chemical approaches that can target specific compounds of the BBB and/or BCSF barrier. However, our understanding of transporters at the BBB and BCSF barriers has primarily focused on understanding efflux transporters that efficiently prevent drugs from attaining therapeutic concentrations in the CNS. Recently, through the characterization of multiple endogenously expressed uptake transporters, this paradigm has shifted to the study of brain transporter targets that can facilitate drug delivery (i.e., influx transporters). Additionally, signaling pathways and trafficking mechanisms have been identified for several endogenous BBB/BCSF transporters, thereby offering even more opportunities to understand how transporters can be exploited for optimization of CNS drug delivery. This review presents an overview of the BBB and BCSF barrier as well as the many families of transporters functionally expressed at these barrier sites. Furthermore, we present an overview of various strategies that have been designed and utilized to deliver therapeutic agents to the brain with a particular emphasis on those approaches that directly target endogenous BBB/BCSF barrier transporters.
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Affiliation(s)
| | | | | | | | - Patrick T Ronaldson
- Department of Medical Pharmacology, College of Medicine, University of Arizona, 1501 North Campbell Avenue, P.O. Box 245050, Tucson, AZ, 85724-5050.
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Schoknecht K, David Y, Heinemann U. The blood-brain barrier-gatekeeper to neuronal homeostasis: clinical implications in the setting of stroke. Semin Cell Dev Biol 2014; 38:35-42. [PMID: 25444848 DOI: 10.1016/j.semcdb.2014.10.004] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2014] [Revised: 10/24/2014] [Accepted: 10/31/2014] [Indexed: 12/23/2022]
Abstract
The blood-brain barrier is part of the neurovascular unit and serves as a functional and anatomical barrier between the blood and the extracellular space. It controls the flow of solutes in and out of the brain thereby providing an optimal environment for neuronal functioning. Paracellular transport between endothelial cells is restricted by tight junctions and transendothelial transport is reduced and more selective compared to capillaries of other organs. Further, the blood-brain barrier is involved in controlling blood flow and it is the site for signaling damage of the nervous system to the peripheral immune system. As an important player in brain homeostasis, blood-brain barrier dysfunction has been implicated in the pathophysiology of many brain diseases including stroke, traumatic brain injury, brain tumors, epilepsy and neurodegenerative disorders. In this article - highlighting recent advances in basic science - we review the features of the blood-brain barrier and their significance for neuronal homeostasis to discuss clinical implications for neurological complications following cerebral ischemia.
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Affiliation(s)
- Karl Schoknecht
- Institute for Neurophysiology, Charité - University Medicine Berlin, Germany
| | - Yaron David
- Departments of Physiology & Cell Biology, Cognitive & Brain Sciences, The Zlotowski Center for Neuroscience, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Uwe Heinemann
- Institute for Neurophysiology, Charité - University Medicine Berlin, Germany.
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42
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Drug Access to the Central Nervous System in Alzheimer’s Disease: Preclinical and Clinical Insights. Pharm Res 2014; 32:819-39. [DOI: 10.1007/s11095-014-1522-0] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2014] [Accepted: 09/12/2014] [Indexed: 12/12/2022]
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43
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Affiliation(s)
- Yarong He
- From the Emergency Department, West China Hospital, Sichuan University, Chengdu, Sichuan, People's Republic of China (Y.H., Y.C.); Laboratory of Neurobiology and Genetics, The Rockefeller University, New York, NY (Y.Y.); and Department of Pharmacological Sciences, Stony Brook University, NY (S.E.T.)
| | - Yao Yao
- From the Emergency Department, West China Hospital, Sichuan University, Chengdu, Sichuan, People's Republic of China (Y.H., Y.C.); Laboratory of Neurobiology and Genetics, The Rockefeller University, New York, NY (Y.Y.); and Department of Pharmacological Sciences, Stony Brook University, NY (S.E.T.)
| | - Stella E Tsirka
- From the Emergency Department, West China Hospital, Sichuan University, Chengdu, Sichuan, People's Republic of China (Y.H., Y.C.); Laboratory of Neurobiology and Genetics, The Rockefeller University, New York, NY (Y.Y.); and Department of Pharmacological Sciences, Stony Brook University, NY (S.E.T.)
| | - Yu Cao
- From the Emergency Department, West China Hospital, Sichuan University, Chengdu, Sichuan, People's Republic of China (Y.H., Y.C.); Laboratory of Neurobiology and Genetics, The Rockefeller University, New York, NY (Y.Y.); and Department of Pharmacological Sciences, Stony Brook University, NY (S.E.T.).
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44
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Vendel E, de Lange ECM. Functions of the CB1 and CB 2 receptors in neuroprotection at the level of the blood-brain barrier. Neuromolecular Med 2014; 16:620-42. [PMID: 24929655 DOI: 10.1007/s12017-014-8314-x] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2014] [Accepted: 05/14/2014] [Indexed: 12/30/2022]
Abstract
The cannabinoid (CB) receptors are the main targets of the cannabinoids, which include plant cannabinoids, endocannabinoids and synthetic cannabinoids. Over the last few years, accumulated evidence has suggested a role of the CB receptors in neuroprotection. The blood-brain barrier (BBB) is an important brain structure that is essential for neuroprotection. A link between the CB receptors and the BBB is thus likely, but this possible connection has only recently gained attention. Cannabinoids and the BBB share the same mechanisms of neuroprotection and both protect against excitotoxicity (CB1), cell death (CB1), inflammation (CB2) and oxidative stress (possibly CB independent)-all processes that also damage the BBB. Several examples of CB-mediated protection of the BBB have been found, such as inhibition of leukocyte influx and induction of amyloid beta efflux across the BBB. Moreover, the CB receptors were shown to improve BBB integrity, particularly by restoring the tightness of the tight junctions. This review demonstrated that both CB receptors are able to restore the BBB and neuroprotection, but much uncertainty about the underlying signaling cascades still exists and further investigation is needed.
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Affiliation(s)
- Esmée Vendel
- Division of Pharmacology, Leiden Academic Centre for Drug Research, Leiden University, Einsteinweg 55, 2333CC, PO Box 9502, 2300 RA, Leiden, The Netherlands
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45
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Subarachnoid Hemorrhage: a Review of Experimental Studies on the Microcirculation and the Neurovascular Unit. Transl Stroke Res 2014; 5:174-89. [DOI: 10.1007/s12975-014-0323-4] [Citation(s) in RCA: 93] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2013] [Revised: 12/20/2013] [Accepted: 01/03/2014] [Indexed: 11/29/2022]
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46
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Yao Y, Tsirka SE. Monocyte chemoattractant protein-1 and the blood-brain barrier. Cell Mol Life Sci 2014; 71:683-97. [PMID: 24051980 PMCID: PMC3946874 DOI: 10.1007/s00018-013-1459-1] [Citation(s) in RCA: 129] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2013] [Revised: 07/20/2013] [Accepted: 08/19/2013] [Indexed: 12/17/2022]
Abstract
The blood-brain barrier (BBB) is a dynamic structure that maintains the homeostasis of the brain and thus proper neurological functions. BBB compromise has been found in many pathological conditions, including neuroinflammation. Monocyte chemoattractant protein-1 (MCP1), a chemokine that is transiently and significantly up-regulated during inflammation, is able to disrupt the integrity of BBB and modulate the progression of various diseases, including excitotoxic injury and hemorrhage. In this review, we first introduce the biochemistry and biology of MCP1, and then summarize the effects of MCP1 on BBB integrity as well as individual BBB components.
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Affiliation(s)
- Yao Yao
- Program in Molecular and Cellular Pharmacology, Department of Pharmacological Sciences, BST8-192, Stony Brook University, Stony Brook, NY 11794-8651 USA
- Laboratory of Neurobiology and Genetics, The Rockefeller University, New York, NY 10065 USA
| | - Stella E. Tsirka
- Program in Molecular and Cellular Pharmacology, Department of Pharmacological Sciences, BST8-192, Stony Brook University, Stony Brook, NY 11794-8651 USA
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47
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Ball K, Bouzom F, Scherrmann JM, Walther B, Declèves X. A Physiologically Based Modeling Strategy during Preclinical CNS Drug Development. Mol Pharm 2014; 11:836-48. [DOI: 10.1021/mp400533q] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Kathryn Ball
- Centre de Pharmacocinétique et Métabolisme, Groupe de Recherche Servier, Orléans, France
| | - François Bouzom
- Centre de Pharmacocinétique et Métabolisme, Groupe de Recherche Servier, Orléans, France
| | - Jean-Michel Scherrmann
- Neuropsychopharmacologie
des addictions (CNRS UMR 8206), Faculté de Pharmacie, Université Paris Descartes, Paris, France
- INSERM U705, Neuropsychopharmacologie des addictions, Paris, France
| | - Bernard Walther
- Centre de Pharmacocinétique et Métabolisme, Groupe de Recherche Servier, Orléans, France
| | - Xavier Declèves
- Neuropsychopharmacologie
des addictions (CNRS UMR 8206), Faculté de Pharmacie, Université Paris Descartes, Paris, France
- INSERM U705, Neuropsychopharmacologie des addictions, Paris, France
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48
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49
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Wong AD, Ye M, Levy AF, Rothstein JD, Bergles DE, Searson PC. The blood-brain barrier: an engineering perspective. FRONTIERS IN NEUROENGINEERING 2013; 6:7. [PMID: 24009582 PMCID: PMC3757302 DOI: 10.3389/fneng.2013.00007] [Citation(s) in RCA: 375] [Impact Index Per Article: 34.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/02/2013] [Accepted: 08/07/2013] [Indexed: 12/03/2022]
Abstract
It has been more than 100 years since Paul Ehrlich reported that various water-soluble dyes injected into the circulation did not enter the brain. Since Ehrlich's first experiments, only a small number of molecules, such as alcohol and caffeine have been found to cross the blood-brain barrier, and this selective permeability remains the major roadblock to treatment of many central nervous system diseases. At the same time, many central nervous system diseases are associated with disruption of the blood-brain barrier that can lead to changes in permeability, modulation of immune cell transport, and trafficking of pathogens into the brain. Therefore, advances in our understanding of the structure and function of the blood-brain barrier are key to developing effective treatments for a wide range of central nervous system diseases. Over the past 10 years it has become recognized that the blood-brain barrier is a complex, dynamic system that involves biomechanical and biochemical signaling between the vascular system and the brain. Here we reconstruct the structure, function, and transport properties of the blood-brain barrier from an engineering perspective. New insight into the physics of the blood-brain barrier could ultimately lead to clinical advances in the treatment of central nervous system diseases.
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Affiliation(s)
- Andrew D. Wong
- Department of Materials Science and Engineering, Johns Hopkins UniversityBaltimore, MD, USA
- Institute for Nanobiotechnology, Johns Hopkins UniversityBaltimore, MD, USA
| | - Mao Ye
- Department of Materials Science and Engineering, Johns Hopkins UniversityBaltimore, MD, USA
- Institute for Nanobiotechnology, Johns Hopkins UniversityBaltimore, MD, USA
| | - Amanda F. Levy
- Department of Materials Science and Engineering, Johns Hopkins UniversityBaltimore, MD, USA
- Institute for Nanobiotechnology, Johns Hopkins UniversityBaltimore, MD, USA
| | - Jeffrey D. Rothstein
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins UniversityBaltimore, MD, USA
- Brain Sciences Institute, Johns Hopkins UniversityBaltimore, MD, USA
| | - Dwight E. Bergles
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins UniversityBaltimore, MD, USA
| | - Peter C. Searson
- Department of Materials Science and Engineering, Johns Hopkins UniversityBaltimore, MD, USA
- Institute for Nanobiotechnology, Johns Hopkins UniversityBaltimore, MD, USA
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Weise G, Stoll G. Magnetic resonance imaging of blood brain/nerve barrier dysfunction and leukocyte infiltration: closely related or discordant? Front Neurol 2012; 3:178. [PMID: 23267343 PMCID: PMC3527731 DOI: 10.3389/fneur.2012.00178] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2012] [Accepted: 12/03/2012] [Indexed: 11/13/2022] Open
Abstract
Unlike other organs the nervous system is secluded from the rest of the organism by the blood brain barrier (BBB) or blood nerve barrier (BNB) preventing passive influx of fluids from the circulation. Similarly, leukocyte entry to the nervous system is tightly controlled. Breakdown of these barriers and cellular inflammation are hallmarks of inflammatory as well as ischemic neurological diseases and thus represent potential therapeutic targets. The spatiotemporal relationship between BBB/BNB disruption and leukocyte infiltration has been a matter of debate. We here review contrast-enhanced magnetic resonance imaging (MRI) as a non-invasive tool to depict barrier dysfunction and its relation to macrophage infiltration in the central and peripheral nervous system under pathological conditions. Novel experimental contrast agents like Gadofluorine M (Gf) allow more sensitive assessment of BBB dysfunction than conventional Gadolinium (Gd)-DTPA enhanced MRI. In addition, Gf facilitates visualization of functional and transient alterations of the BBB remote from lesions. Cellular contrast agents such as superparamagnetic iron oxide particles (SPIO) and perfluorocarbons enable assessment of leukocyte (mainly macrophage) infiltration by MR technology. Combined use of these MR contrast agents disclosed that leukocytes can enter the nervous system independent from a disturbance of the BBB, and vice versa, a dysfunctional BBB/BNB by itself is not sufficient to attract inflammatory cells from the circulation. We will illustrate these basic imaging findings in animal models of multiple sclerosis, cerebral ischemia, and traumatic nerve injury and review corresponding findings in patients.
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Affiliation(s)
- Gesa Weise
- Department of Neurology, University of Wuerzburg Wuerzburg, Germany ; Fraunhofer Institute for Cell Therapy and Immunology Leipzig, Germany ; Translational Center for Regenerative Medicine Leipzig, Germany
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