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Milewski K, Orzeł-Gajowik K, Zielińska M. Mitochondrial Changes in Rat Brain Endothelial Cells Associated with Hepatic Encephalopathy: Relation to the Blood-Brain Barrier Dysfunction. Neurochem Res 2024; 49:1489-1504. [PMID: 35917006 PMCID: PMC11106209 DOI: 10.1007/s11064-022-03698-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Revised: 02/17/2022] [Accepted: 07/14/2022] [Indexed: 12/06/2022]
Abstract
The mechanisms underlying cerebral vascular dysfunction and edema during hepatic encephalopathy (HE) are unclear. Blood-brain barrier (BBB) impairment, resulting from increased vascular permeability, has been reported in acute and chronic HE. Mitochondrial dysfunction is a well-documented result of HE mainly affecting astrocytes, but much less so in the BBB-forming endothelial cells. Here we review literature reports and own experimental data obtained in HE models emphasizing alterations in mitochondrial dynamics and function as a possible contributor to the status of brain endothelial cell mitochondria in HE. Own studies on the expression of the mitochondrial fusion-fission controlling genes rendered HE animal model-dependent effects: increase of mitochondrial fusion controlling genes opa1, mfn1 in cerebral vessels in ammonium acetate-induced hyperammonemia, but a decrease of the two former genes and increase of fis1 in vessels in thioacetamide-induced HE. In endothelial cell line (RBE4) after 24 h ammonia and/or TNFα treatment, conditions mimicking crucial aspects of HE in vivo, we observed altered expression of mitochondrial fission/fusion genes: a decrease of opa1, mfn1, and, increase of the fission related fis1 gene. The effect in vitro was paralleled by the generation of reactive oxygen species, decreased total antioxidant capacity, decreased mitochondrial membrane potential, as well as increased permeability of RBE4 cell monolayer to fluorescein isothiocyanate dextran. Electron microscopy documented enlarged mitochondria in the brain endothelial cells of rats in both in vivo models. Collectively, the here observed alterations of cerebral endothelial mitochondria are indicative of their fission, and decreased potential of endothelial mitochondria are likely to contribute to BBB dysfunction in HE.
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Affiliation(s)
- Krzysztof Milewski
- Department of Neurotoxicology, Mossakowski Medical Research Institute, Polish Academy of Sciences, Pawińskiego St. 5, 02-106, Warsaw, Poland.
| | - Karolina Orzeł-Gajowik
- Department of Neurotoxicology, Mossakowski Medical Research Institute, Polish Academy of Sciences, Pawińskiego St. 5, 02-106, Warsaw, Poland
| | - Magdalena Zielińska
- Department of Neurotoxicology, Mossakowski Medical Research Institute, Polish Academy of Sciences, Pawińskiego St. 5, 02-106, Warsaw, Poland.
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2
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Halder SK, Sapkota A, Milner R. β1 integrins play a critical role maintaining vascular integrity in the hypoxic spinal cord, particularly in white matter. Acta Neuropathol Commun 2024; 12:45. [PMID: 38509621 PMCID: PMC10953150 DOI: 10.1186/s40478-024-01749-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2023] [Accepted: 02/24/2024] [Indexed: 03/22/2024] Open
Abstract
Interactions between extracellular matrix (ECM) proteins and β1 integrins play an essential role maintaining vascular integrity in the brain, particularly under vascular remodeling conditions. As blood vessels in the spinal cord are reported to have distinct properties from those in the brain, here we examined the impact of β1 integrin inhibition on spinal cord vascular integrity, both under normoxic conditions, when blood vessels are stable, and during exposure to chronic mild hypoxia (CMH), when extensive vascular remodeling occurs. We found that a function-blocking β1 integrin antibody triggered a small degree of vascular disruption in the spinal cord under normoxic conditions, but under hypoxic conditions, it greatly enhanced (20-fold) vascular disruption, preferentially in spinal cord white matter (WM). This resulted in elevated microglial activation as well as marked loss of myelin integrity and reduced density of oligodendroglial cells. To understand why vascular breakdown is localized to WM, we compared expression levels of major BBB components of WM and grey matter (GM) blood vessels, but this revealed no obvious differences. Interestingly however, hypoxyprobe staining demonstrated that the most severe levels of spinal cord hypoxia induced by CMH occurred in the WM. Analysis of brain tissue revealed a similar preferential vulnerability of WM tracts to show vascular disruption under these conditions. Taken together, these findings demonstrate an essential role for β1 integrins in maintaining vascular integrity in the spinal cord, and unexpectedly, reveal a novel and fundamental difference between WM and GM blood vessels in their dependence on β1 integrin function during hypoxic exposure. Our data support the concept that the preferential WM vulnerability described may be less a result of intrinsic differences in vascular barrier properties between WM and GM, and more a consequence of differences in vascular density and architecture.
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Affiliation(s)
- Sebok K Halder
- San Diego Biomedical Research Institute, 3525 John Hopkins Court, Suite 200, 92121, San Diego, CA, USA
| | - Arjun Sapkota
- San Diego Biomedical Research Institute, 3525 John Hopkins Court, Suite 200, 92121, San Diego, CA, USA
| | - Richard Milner
- San Diego Biomedical Research Institute, 3525 John Hopkins Court, Suite 200, 92121, San Diego, CA, USA.
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3
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Halder SK, Sapkota A, Milner R. The importance of laminin at the blood-brain barrier. Neural Regen Res 2023; 18:2557-2563. [PMID: 37449589 DOI: 10.4103/1673-5374.373677] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/18/2023] Open
Abstract
The blood-brain barrier is a unique property of central nervous system blood vessels that protects sensitive central nervous system cells from potentially harmful blood components. The mechanistic basis of this barrier is found at multiple levels, including the adherens and tight junction proteins that tightly bind adjacent endothelial cells and the influence of neighboring pericytes, microglia, and astrocyte endfeet. In addition, extracellular matrix components of the vascular basement membrane play a critical role in establishing and maintaining blood-brain barrier integrity, not only by providing an adhesive substrate for blood-brain barrier cells to adhere to, but also by providing guidance cues that strongly influence vascular cell behavior. The extracellular matrix protein laminin is one of the most abundant components of the basement membrane, and several lines of evidence suggest that it plays a key role in directing blood-brain barrier behavior. In this review, we describe the basic structure of laminin and its receptors, the expression patterns of these molecules in central nervous system blood vessels and how they are altered in disease states, and most importantly, how genetic deletion of different laminin isoforms or their receptors reveals the contribution of these molecules to blood-brain barrier function and integrity. Finally, we discuss some of the important unanswered questions in the field and provide a "to-do" list of some of the critical outstanding experiments.
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Affiliation(s)
- Sebok K Halder
- San Diego Biomedical Research Institute, San Diego, CA, USA
| | - Arjun Sapkota
- San Diego Biomedical Research Institute, San Diego, CA, USA
| | - Richard Milner
- San Diego Biomedical Research Institute, San Diego, CA, USA
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Xie Y, Luo Z, Peng W, Liu Y, Yuan F, Xu J, Sun Y, Lu H, Wu T, Jiang L, Hu J. Inhibition of UTX/KDM6A improves recovery of spinal cord injury by attenuating BSCB permeability and macrophage infiltration through the MLCK/p-MLC pathway. J Neuroinflammation 2023; 20:259. [PMID: 37951955 PMCID: PMC10638785 DOI: 10.1186/s12974-023-02936-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2023] [Accepted: 10/18/2023] [Indexed: 11/14/2023] Open
Abstract
Spinal cord injury (SCI) can prompt an immediate disruption to the blood-spinal cord barrier (BSCB). Restoring the integrity of this barrier is vital for the recovery of neurological function post-SCI. The UTX protein, a histone demethylase, has been shown in previous research to promote vascular regeneration and neurological recovery in mice with SCI. However, it is unclear whether UTX knockout could facilitate the recovery of the BSCB by reducing its permeability. In this study, we systematically studied BSCB disruption and permeability at different time points after SCI and found that conditional UTX deletion in endothelial cells (ECs) can reduce BSCB permeability, decrease inflammatory cell infiltration and ROS production, and improve neurological function recovery after SCI. Subsequently, we used RNA sequencing and ChIP-qPCR to confirm that conditional UTX knockout in ECs can down-regulate expression of myosin light chain kinase (MLCK), which specifically mediates myosin light chain (MLC) phosphorylation and is involved in actin contraction, cell retraction, and tight junctions (TJs) protein integrity. Moreover, we found that MLCK overexpression can increase the ratio of p-MLC/MLC, further break TJs, and exacerbate BSCB deterioration. Overall, our findings indicate that UTX knockout could inhibit the MLCK/p-MLC pathway, resulting in decreased BSCB permeability, and ultimately promoting neurological recovery in mice. These results suggest that UTX is a promising new target for treating SCI.
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Affiliation(s)
- Yong Xie
- Department of Spine Surgery and Orthopaedics, Xiangya Hospital, Central South University, Changsha, China
- Key Laboratory of Organ Injury, Aging and Regenerative Medicine of Hunan Province, Changsha, China
- Hunan Engineering Research Center of Sports and Health, Changsha, China
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China
| | - Zixiang Luo
- Department of Spine Surgery and Orthopaedics, Xiangya Hospital, Central South University, Changsha, China
- Key Laboratory of Organ Injury, Aging and Regenerative Medicine of Hunan Province, Changsha, China
- Hunan Engineering Research Center of Sports and Health, Changsha, China
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China
| | - Wei Peng
- Department of Spine Surgery and Orthopaedics, Xiangya Hospital, Central South University, Changsha, China
- Key Laboratory of Organ Injury, Aging and Regenerative Medicine of Hunan Province, Changsha, China
- Hunan Engineering Research Center of Sports and Health, Changsha, China
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China
| | - Yudong Liu
- Department of Spine Surgery and Orthopaedics, Xiangya Hospital, Central South University, Changsha, China
- Key Laboratory of Organ Injury, Aging and Regenerative Medicine of Hunan Province, Changsha, China
- Hunan Engineering Research Center of Sports and Health, Changsha, China
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China
| | - Feifei Yuan
- Department of Spine Surgery and Orthopaedics, Xiangya Hospital, Central South University, Changsha, China
- Key Laboratory of Organ Injury, Aging and Regenerative Medicine of Hunan Province, Changsha, China
- Hunan Engineering Research Center of Sports and Health, Changsha, China
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China
| | - Jiaqi Xu
- Department of Spine Surgery and Orthopaedics, Xiangya Hospital, Central South University, Changsha, China
- Key Laboratory of Organ Injury, Aging and Regenerative Medicine of Hunan Province, Changsha, China
- Hunan Engineering Research Center of Sports and Health, Changsha, China
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China
| | - Yi Sun
- Department of Spine Surgery and Orthopaedics, Xiangya Hospital, Central South University, Changsha, China
- Key Laboratory of Organ Injury, Aging and Regenerative Medicine of Hunan Province, Changsha, China
- Hunan Engineering Research Center of Sports and Health, Changsha, China
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China
| | - Hongbin Lu
- Department of Sports Medicine, Xiangya Hospital, Central South University, Changsha, China
- Key Laboratory of Organ Injury, Aging and Regenerative Medicine of Hunan Province, Changsha, China
- Hunan Engineering Research Center of Sports and Health, Changsha, China
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China
| | - Tianding Wu
- Department of Spine Surgery and Orthopaedics, Xiangya Hospital, Central South University, Changsha, China.
- Key Laboratory of Organ Injury, Aging and Regenerative Medicine of Hunan Province, Changsha, China.
- Hunan Engineering Research Center of Sports and Health, Changsha, China.
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China.
| | - Liyuan Jiang
- Department of Spine Surgery and Orthopaedics, Xiangya Hospital, Central South University, Changsha, China.
- Key Laboratory of Organ Injury, Aging and Regenerative Medicine of Hunan Province, Changsha, China.
- Hunan Engineering Research Center of Sports and Health, Changsha, China.
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China.
| | - Jianzhong Hu
- Department of Spine Surgery and Orthopaedics, Xiangya Hospital, Central South University, Changsha, China.
- Key Laboratory of Organ Injury, Aging and Regenerative Medicine of Hunan Province, Changsha, China.
- Hunan Engineering Research Center of Sports and Health, Changsha, China.
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China.
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Halder SK, Delorme-Walker VD, Milner R. β1 integrin is essential for blood-brain barrier integrity under stable and vascular remodelling conditions; effects differ with age. Fluids Barriers CNS 2023; 20:52. [PMID: 37400852 DOI: 10.1186/s12987-023-00453-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2022] [Accepted: 06/14/2023] [Indexed: 07/05/2023] Open
Abstract
BACKGROUND Maintaining a tight blood-brain barrier (BBB) is an important prerequisite for the preservation of neurological health, though current evidence suggests it declines with age. While extracellular matrix-integrin interactions play critical roles in regulating the balance between vascular stability and remodeling, it remains to be established whether manipulation of integrin function weakens or strengthens vascular integrity. Indeed, recent reports have generated conflicting outcomes in this regard. METHODS Here, in young (8-10 weeks) and aged (20 months) mice, we examined the impact of intraperitoneal injection of a function-blocking β1 integrin antibody, both under normoxic conditions, when the BBB is stable, and during chronic mild hypoxic (CMH; 8% O2) conditions, when a vigorous vascular remodeling response is ongoing. Brain tissue was examined by immunofluorescence (IF) for markers of vascular remodeling and BBB disruption, and microglial activation and proliferation. Data were analyzed using one-way analysis of variance (ANOVA) followed by Tukey's multiple comparison post-hoc test. RESULTS In both young and aged mice, β1 integrin block greatly amplified hypoxia-induced vascular disruption, though it was much less under normoxic conditions. Interestingly, under both normoxic and hypoxic conditions, β1 integrin antibody-induced BBB disruption was greater in young mice. Enhanced BBB breakdown was associated with increased levels of the leaky BBB marker MECA-32 and with greater loss of endothelial tight junction proteins and the adherens protein VE-cadherin. Surprisingly, β1 integrin blockade did not reduce hypoxia-induced endothelial proliferation, nor did it prevent the hypoxia-associated increase in vascularity. Commensurate with the increased vascular disruption, β1 integrin blockade enhanced microglial activation both in young and aged brain, though the impact was much greater in young brain. In vitro studies revealed that β1 integrin blockade also reduced the integrity of a brain endothelial monolayer and triggered disruptions in tight junction proteins. CONCLUSIONS These data demonstrate that β1 integrin plays an essential role in maintaining BBB integrity, both under stable normoxic conditions and during hypoxia-induced vascular remodeling. As β1 integrin blockade had a greater disruptive effect in young brain, effectively shifting the BBB phenotype of young brain towards that of the aged, we speculate that enhancing β1 integrin function at the aged BBB may hold therapeutic potential by reverting the deteriorating BBB phenotype back towards that of the young.
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Affiliation(s)
- Sebok K Halder
- San Diego Biomedical Research Institute, 3525 John Hopkins Court, Suite 200, San Diego, CA, 92121, USA
| | - Violaine D Delorme-Walker
- San Diego Biomedical Research Institute, 3525 John Hopkins Court, Suite 200, San Diego, CA, 92121, USA
| | - Richard Milner
- San Diego Biomedical Research Institute, 3525 John Hopkins Court, Suite 200, San Diego, CA, 92121, USA.
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6
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Optimization of Parylene C and Parylene N thin films for use in cellular co-culture and tissue barrier models. Sci Rep 2023; 13:4262. [PMID: 36918711 PMCID: PMC10015097 DOI: 10.1038/s41598-023-31305-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2022] [Accepted: 03/09/2023] [Indexed: 03/16/2023] Open
Abstract
Parylene has been used widely used as a coating on medical devices. It has also been used to fabricate thin films and porous membranes upon which to grow cells. Porous membranes are integral components of in vitro tissue barrier and co-culture models, and their interaction with cells and tissues affects the performance and physiological relevance of these model systems. Parylene C and Parylene N are two biocompatible Parylene variants with potential for use in these models, but their effect on cellular behavior is not as well understood as more commonly used cell culture substrates, such as tissue culture treated polystyrene and glass. Here, we use a simple approach for benchtop oxygen plasma treatment and investigate the changes in cell spreading and extracellular matrix deposition as well as the physical and chemical changes in material surface properties. Our results support and build on previous findings of positive effects of plasma treatment on Parylene biocompatibility while showing a more pronounced improvement for Parylene C compared to Parylene N. We measured relatively minor changes in surface roughness following plasma treatments, but significant changes in oxygen concentration at the surface persisted for 7 days and was likely the dominant factor in improving cellular behavior. Overall, this study offers facile and relatively low-cost plasma treatment protocols that provide persistent improvements in cell-substrate interactions on Parylene that match and exceed tissue culture polystyrene.
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7
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Harris WJ, Asselin MC, Hinz R, Parkes LM, Allan S, Schiessl I, Boutin H, Dickie BR. In vivo methods for imaging blood-brain barrier function and dysfunction. Eur J Nucl Med Mol Imaging 2023; 50:1051-1083. [PMID: 36437425 PMCID: PMC9931809 DOI: 10.1007/s00259-022-05997-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Accepted: 10/09/2022] [Indexed: 11/29/2022]
Abstract
The blood-brain barrier (BBB) is the interface between the central nervous system and systemic circulation. It tightly regulates what enters and is removed from the brain parenchyma and is fundamental in maintaining brain homeostasis. Increasingly, the BBB is recognised as having a significant role in numerous neurological disorders, ranging from acute disorders (traumatic brain injury, stroke, seizures) to chronic neurodegeneration (Alzheimer's disease, vascular dementia, small vessel disease). Numerous approaches have been developed to study the BBB in vitro, in vivo, and ex vivo. The complex multicellular structure and effects of disease are difficult to recreate accurately in vitro, and functional aspects of the BBB cannot be easily studied ex vivo. As such, the value of in vivo methods to study the intact BBB cannot be overstated. This review discusses the structure and function of the BBB and how these are affected in diseases. It then discusses in depth several established and novel methods for imaging the BBB in vivo, with a focus on MRI, nuclear imaging, and high-resolution intravital fluorescence microscopy.
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Affiliation(s)
- William James Harris
- Geoffrey Jefferson Brain Research Centre, Manchester Academic Health Science Centre, Northern Care Alliance & University of Manchester, Manchester, UK
- Division of Neuroscience, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, M13 9PL, Manchester, UK
| | - Marie-Claude Asselin
- Division of Informatics, Imaging and Data Sciences, School of Health Sciences, University of Manchester, Manchester, UK
| | - Rainer Hinz
- Wolfson Molecular Imaging Centre, University of Manchester, Manchester, UK
| | - Laura Michelle Parkes
- Geoffrey Jefferson Brain Research Centre, Manchester Academic Health Science Centre, Northern Care Alliance & University of Manchester, Manchester, UK
- Division of Neuroscience, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, M13 9PL, Manchester, UK
| | - Stuart Allan
- Geoffrey Jefferson Brain Research Centre, Manchester Academic Health Science Centre, Northern Care Alliance & University of Manchester, Manchester, UK
- Division of Neuroscience, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, M13 9PL, Manchester, UK
| | - Ingo Schiessl
- Geoffrey Jefferson Brain Research Centre, Manchester Academic Health Science Centre, Northern Care Alliance & University of Manchester, Manchester, UK
- Division of Neuroscience, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, M13 9PL, Manchester, UK
| | - Herve Boutin
- Geoffrey Jefferson Brain Research Centre, Manchester Academic Health Science Centre, Northern Care Alliance & University of Manchester, Manchester, UK.
- Division of Neuroscience, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, M13 9PL, Manchester, UK.
- Wolfson Molecular Imaging Centre, University of Manchester, Manchester, UK.
| | - Ben Robert Dickie
- Geoffrey Jefferson Brain Research Centre, Manchester Academic Health Science Centre, Northern Care Alliance & University of Manchester, Manchester, UK
- Division of Informatics, Imaging and Data Sciences, School of Health Sciences, University of Manchester, Manchester, UK
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Abstract
The endothelium is a dynamic, semipermeable layer lining all blood vessels, regulating blood vessel formation and barrier function. Proper composition and function of the endothelial barrier are required for fluid homeostasis, and clinical conditions characterized by barrier disruption are associated with severe morbidity and high mortality rates. Endothelial barrier properties are regulated by cell-cell junctions and intracellular signaling pathways governing the cytoskeleton, but recent insights indicate an increasingly important role for integrin-mediated cell-matrix adhesion and signaling in endothelial barrier regulation. Here, we discuss diseases characterized by endothelial barrier disruption, and provide an overview of the composition of endothelial cell-matrix adhesion complexes and associated signaling pathways, their crosstalk with cell-cell junctions, and with other receptors. We further present recent insights into the role of cell-matrix adhesions in the developing and mature/adult endothelium of various vascular beds, and discuss how the dynamic regulation and turnover of cell-matrix adhesions regulates endothelial barrier function in (patho)physiological conditions like angiogenesis, inflammation and in response to hemodynamic stress. Finally, as clinical conditions associated with vascular leak still lack direct treatment, we focus on how understanding of endothelial cell-matrix adhesion may provide novel targets for treatment, and discuss current translational challenges and future perspectives.
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Affiliation(s)
- Jurjan Aman
- Department of Pulmonology, Amsterdam University Medical Center, the Netherlands (J.A.)
| | - Coert Margadant
- Department of Medical Oncology, Amsterdam University Medical Center, the NetherlandsInstitute of Biology, Leiden University, the Netherlands (C.M.)
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9
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Harding IC, O'Hare NR, Vigliotti M, Caraballo A, Lee CI, Millican K, Herman IM, Ebong EE. Developing a transwell millifluidic device for studying blood-brain barrier endothelium. LAB ON A CHIP 2022; 22:4603-4620. [PMID: 36326069 DOI: 10.1039/d2lc00657j] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Blood-brain barrier (BBB) endothelial cell (EC) function depends on flow conditions and on supportive cells, like pericytes and astrocytes, which have been shown to be both beneficial and detrimental for brain EC function. Most studies investigating BBB EC function lack physiological relevance, using sub-physiological shear stress magnitudes and/or omitting pericytes and astrocytes. In this study, we developed a millifluidic device compatible with standard transwell inserts to investigate BBB function. In contrast to standard polydimethylsiloxane (PDMS) microfluidic devices, this model allows for easy, reproducible shear stress exposure without common limitations of PDMS devices such as inadequate nutrient diffusion and air bubble formation. In no-flow conditions, we first used the device to examine the impact of primary human pericytes and astrocytes on human brain microvascular EC (HBMEC) barrier integrity. Astrocytes, pericytes, and a 1-to-1 ratio of both cell types increased HBMEC barrier integrity via reduced 3 and 40 kDa fluorescent dextran permeability and increased claudin-5 expression. There were differing levels of low 3 kDa permeability in HBMEC-pericyte, HBMEC-astrocyte, and HBMEC-astrocyte-pericyte co-cultures, while levels of low 40 kDa permeability were consistent across co-cultures. The 3 kDa findings suggest that pericytes provide more barrier support to the BBB model compared to astrocytes, although both supportive cell types are permeability reducers. Incorporation of 24-hour 12 dynes per cm2 flow significantly reduced dextran permeability in HBMEC monolayers, but not in the tri-culture model. These results indicate that tri-culture may exert more pronounced impact on overall BBB permeability than flow exposure. In both cases, monolayer and tri-culture, flow exposure interestingly reduced HBMEC expression of both claudin-5 and occludin. ZO-1 expression, and localization at cell-cell junctions increased in the tri-culture but exhibited no apparent change in the HBMEC monolayer. Under flow conditions, we also observed HBMEC alignment in the tri-culture but not in HBMEC monolayers, indicating supportive cells and flow are both essential to observe brain EC alignment in vitro. Collectively, these results support the necessity of physiologically relevant, multicellular BBB models when investigating BBB EC function. Consideration of the roles of shear stress and supportive cells within the BBB is critical for elucidating the physiology of the neurovascular unit.
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Affiliation(s)
- Ian C Harding
- Department of Bioengineering, Northeastern University, Boston, MA, USA
| | - Nicholas R O'Hare
- Department of Chemical Engineering, Northeastern University, 360 Huntington Avenue, 129 Interdisciplinary Science and Engineering Complex, Boston, MA, 02115, USA.
| | - Mark Vigliotti
- Department of Chemical Engineering, Northeastern University, 360 Huntington Avenue, 129 Interdisciplinary Science and Engineering Complex, Boston, MA, 02115, USA.
| | - Alex Caraballo
- Department of Chemical Engineering, Northeastern University, 360 Huntington Avenue, 129 Interdisciplinary Science and Engineering Complex, Boston, MA, 02115, USA.
| | - Claire I Lee
- Department of Bioengineering, Northeastern University, Boston, MA, USA
| | - Karina Millican
- Department of Bioengineering, Northeastern University, Boston, MA, USA
| | - Ira M Herman
- Department of Developmental, Molecular, and Chemical Biology, Tufts School of Graduate Biomedical Sciences, Boston, MA, USA
- Center for Innovations in Wound Healing Research, Tufts University School of Medicine, Boston, MA, USA
| | - Eno E Ebong
- Department of Bioengineering, Northeastern University, Boston, MA, USA
- Department of Chemical Engineering, Northeastern University, 360 Huntington Avenue, 129 Interdisciplinary Science and Engineering Complex, Boston, MA, 02115, USA.
- Department of Neuroscience, Albert Einstein College of Medicine, New York, NY, USA
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10
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Nirwane A, Yao Y. Cell-specific expression and function of laminin at the neurovascular unit. J Cereb Blood Flow Metab 2022; 42:1979-1999. [PMID: 35796497 PMCID: PMC9580165 DOI: 10.1177/0271678x221113027] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Revised: 06/08/2022] [Accepted: 06/19/2022] [Indexed: 11/17/2022]
Abstract
Laminin, a major component of the basal lamina (BL), is a heterotrimeric protein with many isoforms. In the CNS, laminin is expressed by almost all cell types, yet different cells synthesize distinct laminin isoforms. By binding to its receptors, laminin exerts a wide variety of important functions. However, due to the reciprocal and cell-specific expression of laminin in different cells at the neurovascular unit, its functions in blood-brain barrier (BBB) maintenance and BBB repair after injury are not fully understood. In this review, we focus on the expression and functions of laminin and its receptors in the neurovascular unit under both physiological and pathological conditions. We first briefly introduce the structures of laminin and its receptors. Next, the expression and functions of laminin and its receptors in the CNS are summarized in a cell-specific manner. Finally, we identify the knowledge gap in the field and discuss key questions that need to be answered in the future. Our goal is to provide a comprehensive overview on cell-specific expression of laminin and its receptors in the CNS and their functions on BBB integrity.
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Affiliation(s)
- Abhijit Nirwane
- Department of Molecular Pharmacology and Physiology, Morsani College of Medicine, University of South Florida, Tampa, FL, USA
| | - Yao Yao
- Department of Molecular Pharmacology and Physiology, Morsani College of Medicine, University of South Florida, Tampa, FL, USA
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11
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Davis CM, Lyon-Scott K, Varlamov EV, Zhang WH, Alkayed NJ. Role of Endothelial STAT3 in Cerebrovascular Function and Protection from Ischemic Brain Injury. Int J Mol Sci 2022; 23:12167. [PMID: 36293020 PMCID: PMC9602684 DOI: 10.3390/ijms232012167] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2022] [Revised: 10/04/2022] [Accepted: 10/08/2022] [Indexed: 02/25/2024] Open
Abstract
STAT3 plays a protective role against ischemic brain injury; however, it is not clear which brain cell type mediates this effect, and by which mechanism. We tested the hypothesis that endothelial STAT3 contributes to protection from cerebral ischemia, by preserving cerebrovascular endothelial function and blood-brain barrier (BBB) integrity. The objective of this study was to determine the role of STAT3 in cerebrovascular endothelial cell (EC) survival and function, and its role in tissue outcome after cerebral ischemia. We found that in primary mouse brain microvascular ECs, STAT3 was constitutively active, and its phosphorylation was reduced by oxygen-glucose deprivation (OGD), recovering after re-oxygenation. STAT3 inhibition, using two mechanistically different pharmacological inhibitors, increased EC injury after OGD. The sub-lethal inhibition of STAT3 caused endothelial dysfunction, demonstrated by reduced nitric oxide release in response to acetylcholine and reduced barrier function of the endothelial monolayer. Finally, mice with reduced endothelial STAT3 (Tie2-Cre; STAT3flox/wt) sustained larger brain infarcts after middle cerebral artery occlusion (MCAO) compared to wild-type (WT) littermates. We conclude that STAT3 is vital to maintaining cerebrovascular integrity, playing a role in EC survival and function, and protection against cerebral ischemia. Endothelial STAT3 may serve as a potential target in preventing endothelial dysfunction after stroke.
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Affiliation(s)
- Catherine M. Davis
- Department of Anesthesiology & Perioperative Medicine, Oregon Health & Science University, 3181 S.W. Sam Jackson Pk. Rd., UHN-2, Portland, OR 97239-3098, USA
| | - Kristin Lyon-Scott
- Department of Anesthesiology & Perioperative Medicine, Oregon Health & Science University, 3181 S.W. Sam Jackson Pk. Rd., UHN-2, Portland, OR 97239-3098, USA
| | - Elena V. Varlamov
- Department of Medicine, Division of Endocrinology and Department of Neurological Surgery, Oregon Health & Science University, 3181 S.W. Sam Jackson Pk. Rd., UHN-2, Portland, OR 97239-3098, USA
| | - Wenri H. Zhang
- Department of Anesthesiology & Perioperative Medicine, Oregon Health & Science University, 3181 S.W. Sam Jackson Pk. Rd., UHN-2, Portland, OR 97239-3098, USA
| | - Nabil J. Alkayed
- Department of Anesthesiology & Perioperative Medicine, Oregon Health & Science University, 3181 S.W. Sam Jackson Pk. Rd., UHN-2, Portland, OR 97239-3098, USA
- The Knight Cardiovascular Institute, Oregon Health & Science University, 3181 S.W. Sam Jackson Pk. Rd., UHN-2, Portland, OR 97239-3098, USA
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12
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Cegarra C, Cameron B, Chaves C, Dabdoubi T, Do TM, Genêt B, Roudières V, Shi Y, Tchepikoff P, Lesuisse D. An innovative strategy to identify new targets for delivering antibodies to the brain has led to the exploration of the integrin family. PLoS One 2022; 17:e0274667. [PMID: 36108060 PMCID: PMC9477330 DOI: 10.1371/journal.pone.0274667] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2022] [Accepted: 09/01/2022] [Indexed: 11/19/2022] Open
Abstract
Background
Increasing brain exposure of biotherapeutics is key to success in central nervous system disease drug discovery. Accessing the brain parenchyma is especially difficult for large polar molecules such as biotherapeutics and antibodies because of the blood-brain barrier. We investigated a new immunization strategy to identify novel receptors mediating transcytosis across the blood-brain barrier.
Method
We immunized mice with primary non-human primate brain microvascular endothelial cells to obtain antibodies. These antibodies were screened for their capacity to bind and to be internalized by primary non-human primate brain microvascular endothelial cells and Human Cerebral Microvascular Endothelial Cell clone D3. They were further evaluated for their transcytosis capabilities in three in vitro blood-brain barrier models. In parallel, their targets were identified by two different methods and their pattern of binding to human tissue was investigated using immunohistochemistry.
Results
12 antibodies with unique sequence and internalization capacities were selected amongst more than six hundred. Aside from one antibody targeting Activated Leukocyte Cell Adhesion Molecule and one targeting Striatin3, most of the other antibodies recognized β1 integrin and its heterodimers. The antibody with the best transcytosis capabilities in all blood-brain barrier in vitro models and with the best binding capacity was an anti-αnβ1 integrin. In comparison, commercial anti-integrin antibodies performed poorly in transcytosis assays, emphasizing the originality of the antibodies derived here. Immunohistochemistry studies showed specific vascular staining on human and non-human primate tissues.
Conclusions
This transcytotic behavior has not previously been reported for anti-integrin antibodies. Further studies should be undertaken to validate this new mechanism in vivo and to evaluate its potential in brain delivery.
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Affiliation(s)
- Céline Cegarra
- Rare and Neurologic Diseases Research Therapeutic Area, Sanofi, Chilly Mazarin, France
- * E-mail:
| | | | - Catarina Chaves
- Rare and Neurologic Diseases Research Therapeutic Area, Sanofi, Chilly Mazarin, France
| | | | - Tuan-Minh Do
- Rare and Neurologic Diseases Research Therapeutic Area, Sanofi, Chilly Mazarin, France
| | - Bruno Genêt
- Integrated Drug Discovery, Sanofi, Vitry-Sur-Seine, France
| | - Valérie Roudières
- Rare and Neurologic Diseases Research Therapeutic Area, Sanofi, Chilly Mazarin, France
| | - Yi Shi
- Histology, Translational Sciences, Sanofi, Vitry-Sur-Seine, France
| | | | - Dominique Lesuisse
- Rare and Neurologic Diseases Research Therapeutic Area, Sanofi, Chilly Mazarin, France
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13
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Gu YH, Hawkins BT, Izawa Y, Yoshikawa Y, Koziol JA, Del Zoppo GJ. Intracerebral hemorrhage and thrombin-induced alterations in cerebral microvessel matrix. J Cereb Blood Flow Metab 2022; 42:1732-1747. [PMID: 35510668 PMCID: PMC9441730 DOI: 10.1177/0271678x221099092] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Four phase III clinical trials of oral direct factor Xa or thrombin inhibitors demonstrated significantly lower intracranial hemorrhage compared to warfarin in patients with nonvalvular-atrial fibrillation. This is counter-intuitive to the principle that inhibiting thrombosis should increase hemorrhagic risk. We tested the novel hypothesis that anti-thrombin activity decreases the risk of intracerebral hemorrhage by directly inhibiting thrombin-mediated degradation of cerebral microvessel basal lamina matrix, responsible for preventing hemorrhage. Collagen IV, laminin, and perlecan each contain one or more copies of the unique α-thrombin cleavage site consensus sequence. In blinded controlled experiments, α-thrombin significantly degraded each matrix protein in vitro and in vivo in a concentration-dependent fashion. In vivo stereotaxic injection of α-thrombin significantly increased permeability, local IgG extravasation, and hemoglobin (Hgb) deposition together with microvessel matrix degradation in a mouse model. In all formats the direct anti-thrombin dabigatran completely inhibited matrix degradation by α-thrombin. Fourteen-day oral exposure to dabigatran etexilate-containing chow completely inhibited matrix degradation, the permeability to large molecules, and cerebral hemorrhage associated with α-thrombin. These experiments demonstrate that thrombin can degrade microvessel matrix, leading to hemorrhage, and that inhibition of microvessel matrix degradation by α-thrombin decreases cerebral hemorrhage. Implications for focal ischemia and other conditions are discussed.
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Affiliation(s)
- Yu-Huan Gu
- Division of Hematology, Department of Medicine, University of Washington School of Medicine, Seattle, WA, USA
| | - Brian T Hawkins
- Division of Hematology, Department of Medicine, University of Washington School of Medicine, Seattle, WA, USA.,Duke University Center for WaSH-AID, Department of Eklectrical and Computer Engineering, Duke University, Durham, NC, USA
| | - Yoshikane Izawa
- Division of Hematology, Department of Medicine, University of Washington School of Medicine, Seattle, WA, USA.,Department of Neurology, Keio University School of Medicine, Tokyo, Japan
| | - Yoji Yoshikawa
- Division of Hematology, Department of Medicine, University of Washington School of Medicine, Seattle, WA, USA
| | - James A Koziol
- Department of Molecular Medicine, Scripps Research Institute, La Jolla, CA, USA
| | - Gregory J Del Zoppo
- Division of Hematology, Department of Medicine, University of Washington School of Medicine, Seattle, WA, USA.,Department of Neurology, University of Washington School of Medicine, Seattle, WA, USA
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14
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Abstract
The central nervous system (CNS) has been viewed as an immunologically privileged site, but emerging works are uncovering a large array of neuroimmune interactions primarily occurring at its borders. CNS barriers sites host diverse population of both innate and adaptive immune cells capable of, directly and indirectly, influence the function of the residing cells of the brain parenchyma. These structures are only starting to reveal their role in controlling brain function under normal and pathological conditions and represent an underexplored therapeutic target for the treatment of brain disorders. This review will highlight the development of the CNS barriers to host neuro-immune interactions and emphasize their newly described roles in neurodevelopmental, neurological, and neurodegenerative disorders, particularly for the meninges.
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Affiliation(s)
- Natalie M Frederick
- Department of Neurosciences, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio, USA
| | - Gabriel A Tavares
- Department of Neurosciences, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio, USA
| | - Antoine Louveau
- Department of Neurosciences, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio, USA.,Department of Molecular Medicine, Cleveland Clinic College of Medicine, Case Western Reserve University, Cleveland, Ohio, USA.,Kent University, Neurosciences, School of Biomedical Sciences, Cleveland, Ohio, USA
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15
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Lansdell TA, Chambers LC, Dorrance AM. Endothelial Cells and the Cerebral Circulation. Compr Physiol 2022; 12:3449-3508. [PMID: 35766836 DOI: 10.1002/cphy.c210015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Endothelial cells form the innermost layer of all blood vessels and are the only vascular component that remains throughout all vascular segments. The cerebral vasculature has several unique properties not found in the peripheral circulation; this requires that the cerebral endothelium be considered as a unique entity. Cerebral endothelial cells perform several functions vital for brain health. The cerebral vasculature is responsible for protecting the brain from external threats carried in the blood. The endothelial cells are central to this requirement as they form the basis of the blood-brain barrier. The endothelium also regulates fibrinolysis, thrombosis, platelet activation, vascular permeability, metabolism, catabolism, inflammation, and white cell trafficking. Endothelial cells regulate the changes in vascular structure caused by angiogenesis and artery remodeling. Further, the endothelium contributes to vascular tone, allowing proper perfusion of the brain which has high energy demands and no energy stores. In this article, we discuss the basic anatomy and physiology of the cerebral endothelium. Where appropriate, we discuss the detrimental effects of high blood pressure on the cerebral endothelium and the contribution of cerebrovascular disease endothelial dysfunction and dementia. © 2022 American Physiological Society. Compr Physiol 12:3449-3508, 2022.
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Affiliation(s)
- Theresa A Lansdell
- Department of Pharmacology and Toxicology, College of Osteopathic Medicine, Michigan State University, East Lansing, MI, 48824, USA
| | - Laura C Chambers
- Department of Pharmacology and Toxicology, College of Osteopathic Medicine, Michigan State University, East Lansing, MI, 48824, USA
| | - Anne M Dorrance
- Department of Pharmacology and Toxicology, College of Osteopathic Medicine, Michigan State University, East Lansing, MI, 48824, USA
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16
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Halder SK, Sapkota A, Milner R. The impact of genetic manipulation of laminin and integrins at the blood-brain barrier. Fluids Barriers CNS 2022; 19:50. [PMID: 35690759 PMCID: PMC9188059 DOI: 10.1186/s12987-022-00346-8] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2022] [Accepted: 05/18/2022] [Indexed: 12/26/2022] Open
Abstract
Blood vessels in the central nervous system (CNS) are unique in having high electrical resistance and low permeability, which creates a selective barrier protecting sensitive neural cells within the CNS from potentially harmful components in the blood. The molecular basis of this blood–brain barrier (BBB) is found at the level of endothelial adherens and tight junction protein complexes, extracellular matrix (ECM) components of the vascular basement membrane (BM), and the influence of adjacent pericytes and astrocyte endfeet. Current evidence supports the concept that instructive cues from the BBB ECM are not only important for the development and maturation of CNS blood vessels, but they are also essential for the maintenance of vascular stability and BBB integrity. In this review, we examine the contributions of one of the most abundant ECM proteins, laminin to BBB integrity, and summarize how genetic deletions of different laminin isoforms or their integrin receptors impact BBB development, maturation, and stability.
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Affiliation(s)
- Sebok K Halder
- San Diego Biomedical Research Institute, 3525 John Hopkins Court, Suite 200, San Diego, CA, 92121, USA
| | - Arjun Sapkota
- San Diego Biomedical Research Institute, 3525 John Hopkins Court, Suite 200, San Diego, CA, 92121, USA
| | - Richard Milner
- San Diego Biomedical Research Institute, 3525 John Hopkins Court, Suite 200, San Diego, CA, 92121, USA.
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17
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Blood-brain barrier leakage in Alzheimer's disease: From discovery to clinical relevance. Pharmacol Ther 2022; 234:108119. [PMID: 35108575 PMCID: PMC9107516 DOI: 10.1016/j.pharmthera.2022.108119] [Citation(s) in RCA: 44] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Revised: 01/14/2022] [Accepted: 01/18/2022] [Indexed: 12/16/2022]
Abstract
Alzheimer's disease (AD) is the most common form of dementia. AD brain pathology starts decades before the onset of clinical symptoms. One early pathological hallmark is blood-brain barrier dysfunction characterized by barrier leakage and associated with cognitive decline. In this review, we summarize the existing literature on the extent and clinical relevance of barrier leakage in AD. First, we focus on AD animal models and their susceptibility to barrier leakage based on age and genetic background. Second, we re-examine barrier dysfunction in clinical and postmortem studies, summarize changes that lead to barrier leakage in patients and highlight the clinical relevance of barrier leakage in AD. Third, we summarize signaling mechanisms that link barrier leakage to neurodegeneration and cognitive decline in AD. Finally, we discuss clinical relevance and potential therapeutic strategies and provide future perspectives on investigating barrier leakage in AD. Identifying mechanistic steps underlying barrier leakage has the potential to unravel new targets that can be used to develop novel therapeutic strategies to repair barrier leakage and slow cognitive decline in AD and AD-related dementias.
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18
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Abstract
The brain harbors a unique ability to, figuratively speaking, shift its gears. During wakefulness, the brain is geared fully toward processing information and behaving, while homeostatic functions predominate during sleep. The blood-brain barrier establishes a stable environment that is optimal for neuronal function, yet the barrier imposes a physiological problem; transcapillary filtration that forms extracellular fluid in other organs is reduced to a minimum in brain. Consequently, the brain depends on a special fluid [the cerebrospinal fluid (CSF)] that is flushed into brain along the unique perivascular spaces created by astrocytic vascular endfeet. We describe this pathway, coined the term glymphatic system, based on its dependency on astrocytic vascular endfeet and their adluminal expression of aquaporin-4 water channels facing toward CSF-filled perivascular spaces. Glymphatic clearance of potentially harmful metabolic or protein waste products, such as amyloid-β, is primarily active during sleep, when its physiological drivers, the cardiac cycle, respiration, and slow vasomotion, together efficiently propel CSF inflow along periarterial spaces. The brain's extracellular space contains an abundance of proteoglycans and hyaluronan, which provide a low-resistance hydraulic conduit that rapidly can expand and shrink during the sleep-wake cycle. We describe this unique fluid system of the brain, which meets the brain's requisites to maintain homeostasis similar to peripheral organs, considering the blood-brain-barrier and the paths for formation and egress of the CSF.
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Affiliation(s)
- Martin Kaag Rasmussen
- Center for Translational Neuromedicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Humberto Mestre
- Center for Translational Neuromedicine, University of Rochester Medical Center, Rochester, New York
| | - Maiken Nedergaard
- Center for Translational Neuromedicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Center for Translational Neuromedicine, University of Rochester Medical Center, Rochester, New York
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19
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Markowicz-Piasecka M, Markiewicz A, Darłak P, Sikora J, Adla SK, Bagina S, Huttunen KM. Current Chemical, Biological, and Physiological Views in the Development of Successful Brain-Targeted Pharmaceutics. Neurotherapeutics 2022; 19:942-976. [PMID: 35391662 PMCID: PMC9294128 DOI: 10.1007/s13311-022-01228-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/24/2022] [Indexed: 12/13/2022] Open
Abstract
One of the greatest challenges with successful pharmaceutical treatments of central nervous system (CNS) diseases is the delivery of drugs into their target sites with appropriate concentrations. For example, the physically tight blood-brain barrier (BBB) effectively blocks compounds from penetrating into the brain, also by the action of metabolizing enzymes and efflux transport mechanisms. However, many endogenous compounds, including both smaller compounds and macromolecules, like amino acids, sugars, vitamins, nucleosides, hormones, steroids, and electrolytes, have their peculiar internalization routes across the BBB. These delivery mechanisms, namely carrier-mediated transport and receptor-mediated transcytosis have been utilized to some extent in brain-targeted drug development. The incomplete knowledge of the BBB and the smaller than a desirable number of chemical tools have hindered the development of successful brain-targeted pharmaceutics. This review discusses the recent advancements achieved in the field from the point of medicinal chemistry view and discusses how brain drug delivery can be improved in the future.
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Affiliation(s)
- Magdalena Markowicz-Piasecka
- Laboratory of Bioanalysis, Department of Pharmaceutical Chemistry, Drug Analysis and Radiopharmacy, Medical University of Lodz, ul. Muszyńskiego1, 90-151 Lodz, Poland
| | - Agata Markiewicz
- Students Research Group, Laboratory of Bioanalysis, Department of Pharmaceutical Chemistry, Drug Analysis and Radiopharmacy, Medical University of Lodz, ul. Muszyńskiego 1, 90-151 Lodz, Poland
| | - Patrycja Darłak
- Students Research Group, Laboratory of Bioanalysis, Department of Pharmaceutical Chemistry, Drug Analysis and Radiopharmacy, Medical University of Lodz, ul. Muszyńskiego 1, 90-151 Lodz, Poland
| | - Joanna Sikora
- Department of Bioinorganic Chemistry, Medical University of Lodz, Medical University of Lodz, ul. Muszyńskiego1, 90-151 Lodz, Poland
| | - Santosh Kumar Adla
- School of Pharmacy, Faculty of Health Sciences, University of Eastern Finland, Yliopistonranta 1C, POB 1627, 70211 Kuopio, Finland
- Institute of Organic Chemistry and Biochemistry (IOCB), Czech Academy of Sciences, Flemingovo Namesti 542/2, 160 00 Prague, Czech Republic
| | - Sreelatha Bagina
- Charles River Discovery Research Services Finland Oy, Neulaniementie 4, 70210 Kuopio, Finland
| | - Kristiina M. Huttunen
- School of Pharmacy, Faculty of Health Sciences, University of Eastern Finland, Yliopistonranta 1C, POB 1627, 70211 Kuopio, Finland
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20
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Cader Z. Human Blood-Brain-Barrier In Vitro Models: Overview and Applications. Handb Exp Pharmacol 2022; 273:205-222. [PMID: 34935086 DOI: 10.1007/164_2021_562] [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] [Indexed: 06/14/2023]
Abstract
The human blood-brain-barrier (BBB) is a vital structure for brain health. Conversely it represents a challenge in drug development programmes that require breaching of the barrier in order to access the central nervous system. Very often brain disorders have early dysfunction of the BBB implicating an important role in pathogenesis and disease progression. The development of human in vitro models is a major advance to allow experimental studies and screening assays, although there remain outstanding questions for the field. In this chapter, the current state of the art will be reviewed, with the complementary innovative approaches to in vitro modelling described, from simple 2D-cultures to more complex multi-cell type micro-physiological systems.
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Affiliation(s)
- Zameel Cader
- Translational Molecular Neuroscience Group, University of Oxford, Oxford, UK.
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21
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del Zoppo GJ, Moskowitz MA, Nedergaard M. The Neurovascular Unit and Responses to Ischemia. Stroke 2022. [DOI: 10.1016/b978-0-323-69424-7.00007-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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22
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Long RKM, Piatti L, Korbmacher F, Bernabeu M. Understanding parasite-brain microvascular interactions with engineered 3D blood-brain barrier models. Mol Microbiol 2021; 117:693-704. [PMID: 34837419 DOI: 10.1111/mmi.14852] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Accepted: 11/23/2021] [Indexed: 01/25/2023]
Abstract
Microbial interactions with the blood-brain barrier (BBB) can be highly pathogenic and are still not well understood. Among these, parasites present complex interactions with the brain microvasculature that are difficult to decipher using experimental animal models or reductionist 2D in vitro cultures. Novel 3D engineered blood-brain barrier models hold great promise to overcome limitations in traditional research approaches. These models better mimic the intricate 3D architecture of the brain microvasculature and recapitulate several aspects of BBB properties, physiology, and function. Moreover, they provide improved control over biophysical and biochemical experimental parameters and are compatible with advanced imaging and molecular biology techniques. Here, we review design considerations and methodologies utilized to successfully engineer BBB microvessels. Finally, we highlight the advantages and limitations of existing engineered models and propose applications to study parasite interactions with the BBB, including mechanisms of barrier disruption.
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Affiliation(s)
- Rory K M Long
- European Molecular Biology Laboratory (EMBL) Barcelona, Barcelona, Spain
| | - Livia Piatti
- European Molecular Biology Laboratory (EMBL) Barcelona, Barcelona, Spain
| | | | - Maria Bernabeu
- European Molecular Biology Laboratory (EMBL) Barcelona, Barcelona, Spain
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23
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Halder SK, Milner R. The impact of chronic mild hypoxia on cerebrovascular remodelling; uncoupling of angiogenesis and vascular breakdown. Fluids Barriers CNS 2021; 18:50. [PMID: 34789271 PMCID: PMC8597176 DOI: 10.1186/s12987-021-00284-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2021] [Accepted: 11/01/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Chronic mild hypoxia (CMH, 8% O2) stimulates robust vascular remodelling in the brain, but it also triggers transient vascular disruption. This raises the fundamental question: is the vascular leak an unwanted side-effect of angiogenic remodelling or is it a pathological response, unrelated to endothelial proliferation, in which declining oxygen levels trigger endothelial dysfunction? METHODS To answer this question, mice were exposed to CMH (8% O2) for periods up to 14 days, after which, brain tissue was examined by immunofluorescence (IF) to determine which type of blood vessel (arteriole, capillary or venule) was most commonly associated with endothelial proliferation and vascular leak and how this correlated with tight junction protein expression. Vascular perfusion was examined using DiI. Data were analysed using one-way analysis of variance (ANOVA) followed by Tukey's multiple comparison post-hoc test. RESULTS The following was observed: (1) most endothelial proliferation and extravascular fibrinogen leak occurred in capillaries and to a lesser degree in venules, (2) much to our surprise, endothelial proliferation and extravascular fibrinogen leak never colocalized, (3) interestingly however, endothelial proliferation was strongly associated with an intravascular fibrinogen staining pattern not seen in stable blood vessels, (4) DiI perfusion studies revealed that angiogenic vessels were adequately perfused, suggesting that fibrinogen retention in angiogenic vessels is not due to temporary closure of the vessel, but more likely because fibrinogen is retained within the vessel wall, (5) bromodeoxyuridine (BrdU) labelling as a means to more permanently label proliferating endothelial cells, confirmed lack of any connection between endothelial proliferation and extravascular fibrinogen leak, while (6) in contrast, proliferating microglia were detected within extravascular leaks. CONCLUSIONS Taken together, our findings support the concept that in the short-term, hypoxia-induced endothelial proliferation triggers transient fibrinogen deposition within the walls of angiogenic blood vessels, but no overt vascular leak occurs in these vessels. Importantly, endothelial proliferation and extravascular fibrinogen leaks never co-localize, demonstrating that extravascular leak is not an unwanted side-effect of angiogenic endothelial proliferation, but rather a dysfunctional vascular response to hypoxia that occurs in a distinct group of non-angiogenic blood vessels.
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Affiliation(s)
- Sebok K Halder
- San Diego Biomedical Research Institute, 10865 Road to the Cure, Suite 100, San Diego, CA, 92121, USA
| | - Richard Milner
- San Diego Biomedical Research Institute, 10865 Road to the Cure, Suite 100, San Diego, CA, 92121, USA.
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24
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Deshayes de Cambronne R, Fouet A, Picart A, Bourrel AS, Anjou C, Bouvier G, Candeias C, Bouaboud A, Costa L, Boulay AC, Cohen-Salmon M, Plu I, Rambaud C, Faurobert E, Albigès-Rizo C, Tazi A, Poyart C, Guignot J. CC17 group B Streptococcus exploits integrins for neonatal meningitis development. J Clin Invest 2021; 131:136737. [PMID: 33465054 DOI: 10.1172/jci136737] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2020] [Accepted: 01/13/2021] [Indexed: 12/28/2022] Open
Abstract
Group B Streptococcus (GBS) is the major cause of human neonatal infections. A single clone, designated CC17-GBS, accounts for more than 80% of meningitis cases, the most severe form of the infection. However, the events allowing blood-borne GBS to penetrate the brain remain largely elusive. In this study, we identified the host transmembrane receptors α5β1 and αvβ3 integrins as the ligands of Srr2, a major CC17-GBS-specific adhesin. Two motifs located in the binding region of Srr2 were responsible for the interaction between CC17-GBS and these integrins. We demonstrated in a blood-brain-barrier cellular model that both integrins contributed to the adhesion and internalization of CC17-GBS. Strikingly, both integrins were overexpressed during the postnatal period in the brain vessels of the blood-brain barrier and blood-cerebrospinal fluid barrier and contributed to juvenile susceptibility to CC17 meningitis. Finally, blocking these integrins decreased the ability of CC17-GBS to cross into the CNS of juvenile mice in an in vivo model of meningitis. Our study demonstrated that CC17-GBS exploits integrins in order to cross the brain vessels, leading to meningitis. Importantly, it provides host molecular insights into neonate's susceptibility to CC17-GBS meningitis, thereby opening new perspectives for therapeutic and prevention strategies of GBS-elicited meningitis.
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Affiliation(s)
| | - Agnès Fouet
- Université de Paris, Institut Cochin, INSERM, U1016, CNRS, UMR8104, Paris, France
| | - Amandine Picart
- Université de Paris, Institut Cochin, INSERM, U1016, CNRS, UMR8104, Paris, France
| | - Anne-Sophie Bourrel
- Université de Paris, Institut Cochin, INSERM, U1016, CNRS, UMR8104, Paris, France.,Hôpitaux Universitaires Paris Centre, Cochin, Assistance Publique Hôpitaux de Paris, France
| | - Cyril Anjou
- Université de Paris, Institut Cochin, INSERM, U1016, CNRS, UMR8104, Paris, France
| | - Guillaume Bouvier
- Structural Bioinformatics Unit, Department of Structural Biology and Chemistry, Institut Pasteur, CNRS UMR3528, C3BI, Paris, France
| | - Cristina Candeias
- Université de Paris, Institut Cochin, INSERM, U1016, CNRS, UMR8104, Paris, France
| | - Abdelouhab Bouaboud
- Université de Paris, Institut Cochin, INSERM, U1016, CNRS, UMR8104, Paris, France
| | - Lionel Costa
- Université de Paris, Institut Cochin, INSERM, U1016, CNRS, UMR8104, Paris, France
| | - Anne-Cécile Boulay
- Center for Interdisciplinary Research in Biology (CIRB), Collège de France, CNRS UMR7241, INSERM U1050, PSL Research University, Paris, France
| | - Martine Cohen-Salmon
- Center for Interdisciplinary Research in Biology (CIRB), Collège de France, CNRS UMR7241, INSERM U1050, PSL Research University, Paris, France
| | - Isabelle Plu
- Sorbonne Université/Département de Neuropathologie Raymond Escourolle - Hôpital Pitié-Salpêtrière - Assistance Publique-Hôpitaux de Paris, France
| | - Caroline Rambaud
- Université de Versailles Saint Quentin en Yvelines (Université Paris-Saclay)/Service d'anatomie-pathologique et médecine légale, Hôpital Raymond Poincaré, Garches, France
| | - Eva Faurobert
- INSERM U1209, CNRS UMR 5309, Institute for Advanced Biosciences, France/Université Grenoble Alpes, La Tronche, France
| | - Corinne Albigès-Rizo
- INSERM U1209, CNRS UMR 5309, Institute for Advanced Biosciences, France/Université Grenoble Alpes, La Tronche, France
| | - Asmaa Tazi
- Université de Paris, Institut Cochin, INSERM, U1016, CNRS, UMR8104, Paris, France.,Hôpitaux Universitaires Paris Centre, Cochin, Assistance Publique Hôpitaux de Paris, France.,Centre National de Référence des Streptocoques, France
| | - Claire Poyart
- Université de Paris, Institut Cochin, INSERM, U1016, CNRS, UMR8104, Paris, France.,Hôpitaux Universitaires Paris Centre, Cochin, Assistance Publique Hôpitaux de Paris, France.,Centre National de Référence des Streptocoques, France
| | - Julie Guignot
- Université de Paris, Institut Cochin, INSERM, U1016, CNRS, UMR8104, Paris, France
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25
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Zhang S, Xie B, Wang L, Yang H, Zhang H, Chen Y, Wang F, Liu C, He H. Macrophage-mediated vascular permeability via VLA4/VCAM1 pathway dictates ascites development in ovarian cancer. J Clin Invest 2021; 131:140315. [PMID: 33295887 DOI: 10.1172/jci140315] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Accepted: 11/25/2020] [Indexed: 12/14/2022] Open
Abstract
The development of ascites correlates with advanced stage disease and poor prognosis in ovarian cancer. Vascular permeability is the key pathophysiological change involved in ascites development. Previously, we provided evidence that perivascular M2-like macrophages protect the vascular barrier through direct contact with endothelial cells (ECs). Here, we investigated the molecular mechanism and its clinical significance in the ovarian cancer setting. We found that upon direct coculture with the endothelium, M2 macrophages tuned down their VLA4 and reduced the levels of VCAM1 in ECs. On the other hand, ectopically overexpressing VLA4 in macrophages or VCAM1 in ECs induced hyperpermeability. Mechanistically, downregulation of VLA4 or VCAM1 led to reduced levels of RAC1 and ROS, which resulted in decreased phosphorylation of PYK2 (p-PYK2) and VE-cadherin (p-VE-cad), hence enhancing cell adhesion. Furthermore, targeting the VLA4/VCAM1 axis augmented vascular integrity and abrogated ascites formation in vivo. Finally, VLA4 expression on the macrophages isolated from ascites dictated permeability ex vivo. Importantly, VLA4 antibody acted synergistically with bevacizumab to further enhance the vascular barrier. Taking these data together, we reveal here that M2 macrophages regulate the vascular barrier though the VCAM1/RAC1/ROS/p-PYK2/p-VE-cad cascade, which provides specific therapeutic targets for the treatment of malignant ascites.
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Affiliation(s)
- Shibo Zhang
- Guangdong Provincial Key Laboratory of Biomedical Imaging and Guangdong Provincial Engineering Research Center of Molecular Imaging, The Fifth Affiliated Hospital, Sun Yat-sen University, Zhuhai, China
| | - Bingfan Xie
- Department of Gynaecology, The Fifth Affiliated Hospital of Sun Yat-sen University, Zhuhai, China
| | - Lijie Wang
- Guangdong Provincial Key Laboratory of Biomedical Imaging and Guangdong Provincial Engineering Research Center of Molecular Imaging, The Fifth Affiliated Hospital, Sun Yat-sen University, Zhuhai, China
| | - Hua Yang
- Department of Gynaecology, The Fifth Affiliated Hospital of Sun Yat-sen University, Zhuhai, China
| | - Haopei Zhang
- Guangdong Provincial Key Laboratory of Biomedical Imaging and Guangdong Provincial Engineering Research Center of Molecular Imaging, The Fifth Affiliated Hospital, Sun Yat-sen University, Zhuhai, China
| | - Yuming Chen
- Guangdong Provincial Key Laboratory of Biomedical Imaging and Guangdong Provincial Engineering Research Center of Molecular Imaging, The Fifth Affiliated Hospital, Sun Yat-sen University, Zhuhai, China
| | - Feng Wang
- Department of Gynaecology, The Fifth Affiliated Hospital of Sun Yat-sen University, Zhuhai, China
| | - Changqing Liu
- Department of Gynaecology, The Fifth Affiliated Hospital of Sun Yat-sen University, Zhuhai, China
| | - Huanhuan He
- Guangdong Provincial Key Laboratory of Biomedical Imaging and Guangdong Provincial Engineering Research Center of Molecular Imaging, The Fifth Affiliated Hospital, Sun Yat-sen University, Zhuhai, China
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26
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Schofield CL, Rodrigo-Navarro A, Dalby MJ, Van Agtmael T, Salmeron-Sanchez M. Biochemical‐ and Biophysical‐Induced Barriergenesis in the Blood–Brain Barrier: A Review of Barriergenic Factors for Use in In Vitro Models. ADVANCED NANOBIOMED RESEARCH 2021. [DOI: 10.1002/anbr.202000068] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Affiliation(s)
| | | | - Matthew J. Dalby
- Centre for the Cellular Microenvironment University of Glasgow Glasgow UK
| | - Tom Van Agtmael
- Institute of Cardiovascular and Medical Sciences University of Glasgow Glasgow UK
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27
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Cameron T, Bennet T, Rowe EM, Anwer M, Wellington CL, Cheung KC. Review of Design Considerations for Brain-on-a-Chip Models. MICROMACHINES 2021; 12:441. [PMID: 33921018 PMCID: PMC8071412 DOI: 10.3390/mi12040441] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Revised: 04/12/2021] [Accepted: 04/12/2021] [Indexed: 02/06/2023]
Abstract
In recent years, the need for sophisticated human in vitro models for integrative biology has motivated the development of organ-on-a-chip platforms. Organ-on-a-chip devices are engineered to mimic the mechanical, biochemical and physiological properties of human organs; however, there are many important considerations when selecting or designing an appropriate device for investigating a specific scientific question. Building microfluidic Brain-on-a-Chip (BoC) models from the ground-up will allow for research questions to be answered more thoroughly in the brain research field, but the design of these devices requires several choices to be made throughout the design development phase. These considerations include the cell types, extracellular matrix (ECM) material(s), and perfusion/flow considerations. Choices made early in the design cycle will dictate the limitations of the device and influence the end-point results such as the permeability of the endothelial cell monolayer, and the expression of cell type-specific markers. To better understand why the engineering aspects of a microfluidic BoC need to be influenced by the desired biological environment, recent progress in microfluidic BoC technology is compared. This review focuses on perfusable blood-brain barrier (BBB) and neurovascular unit (NVU) models with discussions about the chip architecture, the ECM used, and how they relate to the in vivo human brain. With increased knowledge on how to make informed choices when selecting or designing BoC models, the scientific community will benefit from shorter development phases and platforms curated for their application.
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Affiliation(s)
- Tiffany Cameron
- School of Biomedical Engineering, University of British Columbia, Vancouver, BC V6T 1Z4, Canada; (T.C.); (T.B.)
- Centre for Blood Research, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - Tanya Bennet
- School of Biomedical Engineering, University of British Columbia, Vancouver, BC V6T 1Z4, Canada; (T.C.); (T.B.)
- Centre for Blood Research, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - Elyn M. Rowe
- Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, BC V6T 1Z4, Canada; (E.M.R.); (M.A.); (C.L.W.)
- Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - Mehwish Anwer
- Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, BC V6T 1Z4, Canada; (E.M.R.); (M.A.); (C.L.W.)
- Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - Cheryl L. Wellington
- Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, BC V6T 1Z4, Canada; (E.M.R.); (M.A.); (C.L.W.)
- Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - Karen C. Cheung
- School of Biomedical Engineering, University of British Columbia, Vancouver, BC V6T 1Z4, Canada; (T.C.); (T.B.)
- Centre for Blood Research, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
- Department of Electrical & Computer Engineering, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
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28
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Nyúl-Tóth Á, Tarantini S, DelFavero J, Yan F, Balasubramanian P, Yabluchanskiy A, Ahire C, Kiss T, Csipo T, Lipecz A, Farkas AE, Wilhelm I, Krizbai IA, Tang Q, Csiszar A, Ungvari Z. Demonstration of age-related blood-brain barrier disruption and cerebromicrovascular rarefaction in mice by longitudinal intravital two-photon microscopy and optical coherence tomography. Am J Physiol Heart Circ Physiol 2021; 320:H1370-H1392. [PMID: 33543687 PMCID: PMC8260380 DOI: 10.1152/ajpheart.00709.2020] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Revised: 01/21/2021] [Accepted: 01/21/2021] [Indexed: 12/25/2022]
Abstract
Age-related blood-brain barrier (BBB) disruption and cerebromicrovascular rarefaction contribute importantly to the pathogenesis of both vascular cognitive impairment and dementia (VCID) and Alzheimer's disease (AD). Recent advances in geroscience research enable development of novel interventions to reverse age-related alterations of the cerebral microcirculation for prevention of VCID and AD. To facilitate this research, there is an urgent need for sensitive and easy-to-adapt imaging methods that enable longitudinal assessment of changes in BBB permeability and brain capillarization in aged mice and that could be used in vivo to evaluate treatment efficiency. To enable longitudinal assessment of changes in BBB permeability in aged mice equipped with a chronic cranial window, we adapted and optimized two different intravital two-photon imaging approaches. By assessing relative fluorescence changes over the baseline within a volume of brain tissue, after qualitative image subtraction of the brain microvasculature, we confirmed that, in 24-mo-old C57BL/6J mice, cumulative permeability of the microvessels to fluorescent tracers of different molecular masses (0.3 to 40 kDa) is significantly increased compared with that of 5-mo-old mice. Real-time recording of vessel cross-sections showed that apparent solute permeability of single microvessels is significantly increased in aged mice vs. young mice. Cortical capillary density, assessed both by intravital two-photon microscopy and optical coherence tomography was also decreased in aged mice vs. young mice. The presented methods have been optimized for longitudinal (over the period of 36 wk) in vivo assessment of cerebromicrovascular health in preclinical geroscience research.NEW & NOTEWORTHY Methods are presented for longitudinal detection of age-related increase in blood-brain barrier permeability and microvascular rarefaction in the mouse cerebral cortex by intravital two-photon microscopy and optical coherence tomography.
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Affiliation(s)
- Ádám Nyúl-Tóth
- Vascular Cognitive Impairment and Neurodegeneration Program, Oklahoma Center For Geroscience and Healthy Aging, Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma
- International Training Program in Geroscience, Institute of Biophysics, Biological Research Centre, Eötvös Loránd Research Network, Szeged, Hungary
| | - Stefano Tarantini
- Vascular Cognitive Impairment and Neurodegeneration Program, Oklahoma Center For Geroscience and Healthy Aging, Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma
- International Training Program in Geroscience, Doctoral School of Basic and Translational Medicine/Department of Public Health, Semmelweis University, Budapest, Hungary
- Department of Health Promotion Sciences, College of Public Health, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma
| | - Jordan DelFavero
- Vascular Cognitive Impairment and Neurodegeneration Program, Oklahoma Center For Geroscience and Healthy Aging, Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma
| | - Feng Yan
- Stephenson School of Biomedical Engineering, Gallogly College of Engineering, The University of Oklahoma, Norman, Oklahoma
| | - Priya Balasubramanian
- Vascular Cognitive Impairment and Neurodegeneration Program, Oklahoma Center For Geroscience and Healthy Aging, Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma
| | - Andriy Yabluchanskiy
- Vascular Cognitive Impairment and Neurodegeneration Program, Oklahoma Center For Geroscience and Healthy Aging, Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma
| | - Chetan Ahire
- Vascular Cognitive Impairment and Neurodegeneration Program, Oklahoma Center For Geroscience and Healthy Aging, Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma
| | - Tamas Kiss
- Vascular Cognitive Impairment and Neurodegeneration Program, Oklahoma Center For Geroscience and Healthy Aging, Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma
- International Training Program in Geroscience, Theoretical Medicine Doctoral School/Departments of Medical Physics and Informatics and Cell Biology and Molecular Medicine, University of Szeged, Szeged, Hungary
| | - Tamas Csipo
- Vascular Cognitive Impairment and Neurodegeneration Program, Oklahoma Center For Geroscience and Healthy Aging, Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma
- International Training Program in Geroscience, Doctoral School of Basic and Translational Medicine/Department of Public Health, Semmelweis University, Budapest, Hungary
| | - Agnes Lipecz
- Vascular Cognitive Impairment and Neurodegeneration Program, Oklahoma Center For Geroscience and Healthy Aging, Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma
- International Training Program in Geroscience, Doctoral School of Basic and Translational Medicine/Department of Public Health, Semmelweis University, Budapest, Hungary
| | - Attila E Farkas
- International Training Program in Geroscience, Institute of Biophysics, Biological Research Centre, Eötvös Loránd Research Network, Szeged, Hungary
- Department of Physiology, Anatomy and Neuroscience, University of Szeged, Szeged, Hungary
| | - Imola Wilhelm
- International Training Program in Geroscience, Institute of Biophysics, Biological Research Centre, Eötvös Loránd Research Network, Szeged, Hungary
- Institute of Life Sciences, Vasile Goldiş Western University of Arad, Arad, Romania
| | - István A Krizbai
- International Training Program in Geroscience, Institute of Biophysics, Biological Research Centre, Eötvös Loránd Research Network, Szeged, Hungary
- Institute of Life Sciences, Vasile Goldiş Western University of Arad, Arad, Romania
| | - Qinggong Tang
- Stephenson School of Biomedical Engineering, Gallogly College of Engineering, The University of Oklahoma, Norman, Oklahoma
| | - Anna Csiszar
- Vascular Cognitive Impairment and Neurodegeneration Program, Oklahoma Center For Geroscience and Healthy Aging, Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma
- International Training Program in Geroscience, Doctoral School of Basic and Translational Medicine/Department of Public Health, Semmelweis University, Budapest, Hungary
- International Training Program in Geroscience, Theoretical Medicine Doctoral School/Departments of Medical Physics and Informatics and Cell Biology and Molecular Medicine, University of Szeged, Szeged, Hungary
| | - Zoltan Ungvari
- Vascular Cognitive Impairment and Neurodegeneration Program, Oklahoma Center For Geroscience and Healthy Aging, Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma
- International Training Program in Geroscience, Doctoral School of Basic and Translational Medicine/Department of Public Health, Semmelweis University, Budapest, Hungary
- Department of Health Promotion Sciences, College of Public Health, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma
- International Training Program in Geroscience, Theoretical Medicine Doctoral School/Departments of Medical Physics and Informatics and Cell Biology and Molecular Medicine, University of Szeged, Szeged, Hungary
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29
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Nemchek V, Haan EM, Mavros R, Macuiba A, Kerr AL. Voluntary exercise ameliorates the good limb training effect in a mouse model of stroke. Exp Brain Res 2021; 239:687-697. [PMID: 33388904 DOI: 10.1007/s00221-020-05994-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2020] [Accepted: 11/19/2020] [Indexed: 12/24/2022]
Abstract
Stroke is the leading cause of long-term disability in the United States, making research on rehabilitation imperative. Stroke rehabilitation typically focuses on recovery of the impaired limb, although this process is tedious. Compensatory use of the intact limb after stroke is more efficient, but it is known to negatively impact the impaired limb. Exercise may help with this problem; research has shown that exercise promotes neuronal growth and prevents cell death. This study used a mouse model to investigate if post-stroke exercise could prevent deterioration of the function of the impaired limb despite compensatory training of the intact limb. Results showed that mice that exercised, in combination with intact limb training, demonstrated improved functional outcome compared to mice that received no training or compensatory limb training only. These findings suggest that exercise can prevent the deterioration of impaired limb functional outcome that is typically seen with intact limb use.
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Affiliation(s)
- Victoria Nemchek
- Neuroscience Program, Illinois Wesleyan University, Bloomington, IL, USA
| | - Emma M Haan
- Department of Psychology, Illinois Wesleyan University, Bloomington, IL, USA
| | - Rachel Mavros
- Department of Psychology, Illinois Wesleyan University, Bloomington, IL, USA
| | - Amanda Macuiba
- Department of Psychology, Illinois Wesleyan University, Bloomington, IL, USA
| | - Abigail L Kerr
- Department of Psychology, Illinois Wesleyan University, Bloomington, IL, USA.
- Neuroscience Program, Illinois Wesleyan University, Bloomington, IL, USA.
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30
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Nian K, Harding IC, Herman IM, Ebong EE. Blood-Brain Barrier Damage in Ischemic Stroke and Its Regulation by Endothelial Mechanotransduction. Front Physiol 2020; 11:605398. [PMID: 33424628 PMCID: PMC7793645 DOI: 10.3389/fphys.2020.605398] [Citation(s) in RCA: 72] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2020] [Accepted: 11/27/2020] [Indexed: 12/21/2022] Open
Abstract
Ischemic stroke, a major cause of mortality in the United States, often contributes to disruption of the blood-brain barrier (BBB). The BBB along with its supportive cells, collectively referred to as the “neurovascular unit,” is the brain’s multicellular microvasculature that bi-directionally regulates the transport of blood, ions, oxygen, and cells from the circulation into the brain. It is thus vital for the maintenance of central nervous system homeostasis. BBB disruption, which is associated with the altered expression of tight junction proteins and BBB transporters, is believed to exacerbate brain injury caused by ischemic stroke and limits the therapeutic potential of current clinical therapies, such as recombinant tissue plasminogen activator. Accumulating evidence suggests that endothelial mechanobiology, the conversion of mechanical forces into biochemical signals, helps regulate function of the peripheral vasculature and may similarly maintain BBB integrity. For example, the endothelial glycocalyx (GCX), a glycoprotein-proteoglycan layer extending into the lumen of bloods vessel, is abundantly expressed on endothelial cells of the BBB and has been shown to regulate BBB permeability. In this review, we will focus on our understanding of the mechanisms underlying BBB damage after ischemic stroke, highlighting current and potential future novel pharmacological strategies for BBB protection and recovery. Finally, we will address the current knowledge of endothelial mechanotransduction in BBB maintenance, specifically focusing on a potential role of the endothelial GCX.
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Affiliation(s)
- Keqing Nian
- Department of Bioengineering, Northeastern University, Boston, MA, United States
| | - Ian C Harding
- Department of Bioengineering, Northeastern University, Boston, MA, United States
| | - Ira M Herman
- Department of Development, Molecular, and Chemical Biology, Tufts Sackler School of Graduate Biomedical Sciences, Boston, MA, United States.,Center for Innovations in Wound Healing Research, Tufts University School of Medicine, Boston, MA, United States
| | - Eno E Ebong
- Department of Bioengineering, Northeastern University, Boston, MA, United States.,Department of Chemical Engineering, Northeastern University, Boston, MA, United States.,Department of Neuroscience, Albert Einstein College of Medicine, New York, NY, United States
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31
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Freitas-Andrade M, Raman-Nair J, Lacoste B. Structural and Functional Remodeling of the Brain Vasculature Following Stroke. Front Physiol 2020; 11:948. [PMID: 32848875 PMCID: PMC7433746 DOI: 10.3389/fphys.2020.00948] [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: 05/11/2020] [Accepted: 07/14/2020] [Indexed: 12/12/2022] Open
Abstract
Maintenance of cerebral blood vessel integrity and regulation of cerebral blood flow ensure proper brain function. The adult human brain represents only a small portion of the body mass, yet about a quarter of the cardiac output is dedicated to energy consumption by brain cells at rest. Due to a low capacity to store energy, brain health is heavily reliant on a steady supply of oxygen and nutrients from the bloodstream, and is thus particularly vulnerable to stroke. Stroke is a leading cause of disability and mortality worldwide. By transiently or permanently limiting tissue perfusion, stroke alters vascular integrity and function, compromising brain homeostasis and leading to widespread consequences from early-onset motor deficits to long-term cognitive decline. While numerous lines of investigation have been undertaken to develop new pharmacological therapies for stroke, only few advances have been made and most clinical trials have failed. Overall, our understanding of the acute and chronic vascular responses to stroke is insufficient, yet a better comprehension of cerebrovascular remodeling following stroke is an essential prerequisite for developing novel therapeutic options. In this review, we present a comprehensive update on post-stroke cerebrovascular remodeling, an important and growing field in neuroscience, by discussing cellular and molecular mechanisms involved, sex differences, limitations of preclinical research design and future directions.
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Affiliation(s)
| | - Joanna Raman-Nair
- Neuroscience Program, Ottawa Hospital Research Institute, Ottawa, ON, Canada
| | - Baptiste Lacoste
- Neuroscience Program, Ottawa Hospital Research Institute, Ottawa, ON, Canada
- Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada
- Brain and Mind Research Institute, University of Ottawa, Ottawa, ON, Canada
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32
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Edwards DN, Salmeron K, Lukins DE, Trout AL, Fraser JF, Bix GJ. Integrin α5β1 inhibition by ATN-161 reduces neuroinflammation and is neuroprotective in ischemic stroke. J Cereb Blood Flow Metab 2020; 40:1695-1708. [PMID: 31575337 PMCID: PMC7370357 DOI: 10.1177/0271678x19880161] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Stroke remains a leading cause of death and disability with limited therapeutic options. Endothelial cell β1 integrin receptors play a direct role in blood-brain barrier (BBB) dysfunction through regulation of tight junction proteins and infiltrating leukocytes, potentially mediated by β1 integrins. Following tandem transient common carotid artery/middle cerebral artery occlusion on wild-type mice, we administered the integrin a5b1 inhibitor, ATN-161, intraperitoneal (IP) injection at 1 mg/kg acutely after reperfusion, on post-stroke day (PSD)1 and PSD2. Systemic changes (heart rate, pulse distension, and body temperature) were determined. Additionally, infarct volume and edema were determined by 2,3-triphenyltetrazolium chloride and magnetic resonance imaging, while neurological changes were evaluated using an 11-point Neuroscore. Brain immunohistochemistry was performed for claudin-5, α5β1, IgG, and CD45 + cells, and quantitative polymerase chain reaction (qPCR) was performed for matrix metalloproteinase-9 (MMP-9), interleukin (IL)-1β, collagen IV, and CXCL12. ATN-161 significantly reduced integrin α5β1 expression in the surrounding peri-infarct region with no systemic changes. Infarct volume, edema, and functional deficit were significantly reduced in ATN-161-treated mice. Furthermore, ATN-161 treatment reduced IgG extravasation into the parenchyma through conserved claudin-5, collagen IV, CXCL12 while reducing MMP-9 transcription. Additionally, IL-1β and CD45 + cells were reduced in the ipsilateral cortex following ATN-161 administration. Collectively, ATN-161 may be a promising novel stroke therapy by reducing post-stroke inflammation and BBB permeability.
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Affiliation(s)
| | - Kathleen Salmeron
- Department of Neuroscience, University of Kentucky, Lexington, USA.,Department of Physiology, University of Kentucky, Lexington, USA
| | | | - Amanda L Trout
- Department of Neurology, University of Kentucky, Lexington, USA
| | - Justin F Fraser
- Department of Neuroscience, University of Kentucky, Lexington, USA.,Department of Radiology, University of Kentucky, Lexington, USA.,Department of Neurology, University of Kentucky, Lexington, USA.,Department of Neurosurgery, University of Kentucky, Lexington, USA.,Center for Advanced Translational Stroke Science, University of Kentucky, Lexington, USA
| | - Gregory J Bix
- Department of Neuroscience, University of Kentucky, Lexington, USA.,Department of Neurology, University of Kentucky, Lexington, USA.,Department of Neurosurgery, University of Kentucky, Lexington, USA.,Center for Advanced Translational Stroke Science, University of Kentucky, Lexington, USA.,Sanders-Brown Center on Aging, University of Kentucky, Lexington, USA
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33
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Ulbrich P, Khoshneviszadeh M, Jandke S, Schreiber S, Dityatev A. Interplay between perivascular and perineuronal extracellular matrix remodelling in neurological and psychiatric diseases. Eur J Neurosci 2020; 53:3811-3830. [DOI: 10.1111/ejn.14887] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2020] [Revised: 05/29/2020] [Accepted: 06/18/2020] [Indexed: 12/31/2022]
Affiliation(s)
- Philipp Ulbrich
- German Center for Neurodegenerative Diseases (DZNE) Magdeburg Germany
- Department of Neurology Otto‐von‐Guericke University Magdeburg Germany
| | - Mahsima Khoshneviszadeh
- German Center for Neurodegenerative Diseases (DZNE) Magdeburg Germany
- Department of Neurology Otto‐von‐Guericke University Magdeburg Germany
| | - Solveig Jandke
- German Center for Neurodegenerative Diseases (DZNE) Magdeburg Germany
- Department of Neurology Otto‐von‐Guericke University Magdeburg Germany
| | - Stefanie Schreiber
- German Center for Neurodegenerative Diseases (DZNE) Magdeburg Germany
- Department of Neurology Otto‐von‐Guericke University Magdeburg Germany
- Center for Behavioral Brain Sciences (CBBS) Magdeburg Germany
| | - Alexander Dityatev
- German Center for Neurodegenerative Diseases (DZNE) Magdeburg Germany
- Center for Behavioral Brain Sciences (CBBS) Magdeburg Germany
- Medical Faculty Otto‐von‐Guericke University Magdeburg Germany
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34
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Stubbs EB. Targeting the blood-nerve barrier for the management of immune-mediated peripheral neuropathies. Exp Neurol 2020; 331:113385. [PMID: 32562668 DOI: 10.1016/j.expneurol.2020.113385] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Revised: 06/03/2020] [Accepted: 06/15/2020] [Indexed: 02/07/2023]
Abstract
Healthy peripheral nerves encounter, with increased frequency, numerous chemical, biological, and biomechanical forces. Over time and with increasing age, these forces collectively contribute to the pathophysiology of a spectrum of traumatic, metabolic, and/or immune-mediated peripheral nerve disorders. The blood-nerve barrier (BNB) serves as a critical first-line defense against chemical and biologic insults while biomechanical forces are continuously buffered by a dense array of longitudinally orientated epineural collagen fibers exhibiting high-tensile strength. As emphasized throughout this Experimental Neurology Special Issue, the BNB is best characterized as a functionally dynamic multicellular vascular unit comprised of not only highly specialized endoneurial endothelial cells, but also associated perineurial cells, pericytes, Schwann cells, basement membrane, and invested axons. The composition of the BNB, while anatomically distinct, is not functionally dissimilar to that of the well characterized neurovascular unit of the central nervous system. While the BNB lacks a glial limitans and an astrocytic endfoot layer, the primary function of both vascular units is to establish, maintain, and protect an optimal endoneurial (PNS) or interstitial (CNS) fluid microenvironment that is vital for proper neuronal function. Altered endoneurial homeostasis as a secondary consequence of BNB dysregulation is considered an early pathological event in the course of a variety of traumatic, immune-mediated, or metabolically acquired peripheral neuropathies. In this review, emerging experimental advancements targeting the endoneurial microvasculature for the therapeutic management of immune-mediated inflammatory peripheral neuropathies, including the AIDP variant of Guillain-Barré syndrome, are discussed.
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Affiliation(s)
- Evan B Stubbs
- Research Service (151), Department of Veterans Affairs, Edward Hines Jr. VA Hospital, Hines, IL 60141, USA; Department of Ophthalmology, Loyola University Health Science Division, Maywood, IL 60153, USA.
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35
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Erickson MA, Wilson ML, Banks WA. In vitro modeling of blood-brain barrier and interface functions in neuroimmune communication. Fluids Barriers CNS 2020; 17:26. [PMID: 32228633 PMCID: PMC7106666 DOI: 10.1186/s12987-020-00187-3] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2020] [Accepted: 03/18/2020] [Indexed: 02/07/2023] Open
Abstract
Neuroimmune communication contributes to both baseline and adaptive physiological functions, as well as disease states. The vascular blood-brain barrier (BBB) and associated cells of the neurovascular unit (NVU) serve as an important interface for immune communication between the brain and periphery through the blood. Immune functions and interactions of the BBB and NVU in this context can be categorized into at least five neuroimmune axes, which include (1) immune modulation of BBB impermeability, (2) immune regulation of BBB transporters, secretions, and other functions, (3) BBB uptake and transport of immunoactive substances, (4) immune cell trafficking, and (5) BBB secretions of immunoactive substances. These axes may act separately or in concert to mediate various aspects of immune signaling at the BBB. Much of what we understand about immune axes has been from work conducted using in vitro BBB models, and recent advances in BBB and NVU modeling highlight the potential of these newer models for improving our understanding of how the brain and immune system communicate. In this review, we discuss how conventional in vitro models of the BBB have improved our understanding of the 5 neuroimmune axes. We further evaluate the existing literature on neuroimmune functions of novel in vitro BBB models, such as those derived from human induced pluripotent stem cells (iPSCs) and discuss their utility in evaluating aspects of neuroimmune communication.
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Affiliation(s)
- Michelle A Erickson
- Geriatric Research Education and Clinical Center, VA Puget Sound Healthcare System, Seattle, WA, 98108, USA.,Division of Gerontology and Geriatric Medicine, Department of Medicine, University of Washington, Seattle, WA, 98104, USA
| | - Miranda L Wilson
- Geriatric Research Education and Clinical Center, VA Puget Sound Healthcare System, Seattle, WA, 98108, USA
| | - William A Banks
- Geriatric Research Education and Clinical Center, VA Puget Sound Healthcare System, Seattle, WA, 98108, USA. .,Division of Gerontology and Geriatric Medicine, Department of Medicine, University of Washington, Seattle, WA, 98104, USA.
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Abstract
Increased microvessel density in the peri-infarct region has been reported and has been correlated with longer survival times in ischemic stroke patients and has improved outcomes in ischemic animal models. This raises the possibility that enhancement of angiogenesis is one of the strategies to facilitate functional recovery after ischemic stroke. Blood vessels and neuronal cells communicate with each other using various mediators and contribute to the pathophysiology of cerebral ischemia as a unit. In this mini-review, we discuss how angiogenesis might couple with axonal outgrowth/neurogenesis and work for functional recovery after cerebral ischemia. Angiogenesis occurs within 4 to 7 days after cerebral ischemia in the border of the ischemic core and periphery. Post-ischemic angiogenesis may contribute to neuronal remodeling in at least two ways and is thought to contribute to functional recovery. First, new blood vessels that are formed after ischemia are thought to have a role in the guidance of sprouting axons by vascular endothelial growth factor and laminin/β1-integrin signaling. Second, blood vessels are thought to enhance neurogenesis in three stages: 1) Blood vessels enhance proliferation of neural stem/progenitor cells by expression of several extracellular signals, 2) microvessels support the migration of neural stem/progenitor cells toward the peri-infarct region by supplying oxygen, nutrients, and soluble factors as well as serving as a scaffold for migration, and 3) oxygenation induced by angiogenesis in the ischemic core is thought to facilitate the differentiation of migrated neural stem/progenitor cells into mature neurons. Thus, the regions of angiogenesis and surrounding tissue may be coupled, representing novel treatment targets.
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Affiliation(s)
- Masahiro Hatakeyama
- Department of Neurology, Brain Research Institute, Niigata University, Niigata, Japan
| | - Itaru Ninomiya
- Department of Neurology, Brain Research Institute, Niigata University, Niigata, Japan
| | - Masato Kanazawa
- Department of Neurology, Brain Research Institute, Niigata University, Niigata, Japan
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Ghosh S, Lalani R, Patel V, Bhowmick S, Misra A. Surface engineered liposomal delivery of therapeutics across the blood brain barrier: recent advances, challenges and opportunities. Expert Opin Drug Deliv 2019; 16:1287-1311. [DOI: 10.1080/17425247.2019.1676721] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Affiliation(s)
- Saikat Ghosh
- Department of Pharmaceutics, Faculty of Pharmacy, Kalabhavan Campus, The Maharaja Sayajirao University of Baroda, Vadodara, India
- Formulation Development Department-Novel Drug Delivery Systems, Sun Pharmaceutical Industries Ltd, Vadodara, India
| | - Rohan Lalani
- Department of Pharmaceutics, Faculty of Pharmacy, Kalabhavan Campus, The Maharaja Sayajirao University of Baroda, Vadodara, India
- Formulation Development Department-Novel Drug Delivery Systems, Sun Pharmaceutical Industries Ltd, Vadodara, India
| | - Vivek Patel
- Department of Pharmaceutics, Faculty of Pharmacy, Kalabhavan Campus, The Maharaja Sayajirao University of Baroda, Vadodara, India
| | - Subhas Bhowmick
- Department of Pharmaceutics, Faculty of Pharmacy, Kalabhavan Campus, The Maharaja Sayajirao University of Baroda, Vadodara, India
- Formulation Development Department-Novel Drug Delivery Systems, Sun Pharmaceutical Industries Ltd, Vadodara, India
| | - Ambikanandan Misra
- Department of Pharmaceutics, Faculty of Pharmacy, Kalabhavan Campus, The Maharaja Sayajirao University of Baroda, Vadodara, India
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A critical role for microglia in maintaining vascular integrity in the hypoxic spinal cord. Proc Natl Acad Sci U S A 2019; 116:26029-26037. [PMID: 31772011 DOI: 10.1073/pnas.1912178116] [Citation(s) in RCA: 57] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Hypoxic preconditioning reduces disease severity in a mouse model of multiple sclerosis (MS), in part by enhancing the barrier properties of spinal cord blood vessels. Because other studies have shown that similar levels of hypoxia transiently increase permeability of central nervous system (CNS) blood vessels, the goal of this study was to define the impact of chronic mild hypoxia (CMH, 8% O2) on the integrity of spinal cord blood vessels and the responses of neighboring glial cells. Using extravascular fibrinogen as a marker of vascular disruption, we found that CMH triggered transient vascular leak in spinal cord blood vessels, particularly in white matter, which was associated with clustering and activation of Mac-1-positive microglia around disrupted vessels. Microglial depletion with the colony stimulating factor-1 receptor (CSF-1R) inhibitor PLX5622, while having no effect under normoxic conditions, profoundly increased vascular leak in both white and gray matter during CMH, and this was associated with disruption of astrocyte-vascular coupling and enhanced loss of tight junction proteins. Microglial repair of leaky blood vessels was blocked by a peptide that inhibits the interaction between fibrinogen and its Mac-1 integrin receptor. These findings highlight an important role for microglia in maintaining vascular integrity in the hypoxic spinal cord and suggest that a fibrinogen-Mac-1 interaction underpins this response. As relative hypoxia is experienced in many situations including high altitude, lung disease, obstructive sleep apnea, and age-related CNS ischemia/hypoxia, our findings have important implications regarding the critical role of microglia in maintaining vascular integrity in the CNS.
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Costea L, Mészáros Á, Bauer H, Bauer HC, Traweger A, Wilhelm I, Farkas AE, Krizbai IA. The Blood-Brain Barrier and Its Intercellular Junctions in Age-Related Brain Disorders. Int J Mol Sci 2019; 20:ijms20215472. [PMID: 31684130 PMCID: PMC6862160 DOI: 10.3390/ijms20215472] [Citation(s) in RCA: 57] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2019] [Revised: 10/30/2019] [Accepted: 11/01/2019] [Indexed: 12/14/2022] Open
Abstract
With age, our cognitive skills and abilities decline. Maybe starting as an annoyance, this decline can become a major impediment to normal daily life. Recent research shows that the neurodegenerative disorders responsible for age associated cognitive dysfunction are mechanistically linked to the state of the microvasculature in the brain. When the microvasculature does not function properly, ischemia, hypoxia, oxidative stress and related pathologic processes ensue, further damaging vascular and neural function. One of the most important and specialized functions of the brain microvasculature is the blood-brain barrier (BBB), which controls the movement of molecules between blood circulation and the brain parenchyma. In this review, we are focusing on tight junctions (TJs), the multiprotein complexes that play an important role in establishing and maintaining barrier function. After a short introduction of the cell types that modulate barrier function via intercellular communication, we examine how age, age related pathologies and the aging of the immune system affects TJs. Then, we review how the TJs are affected in age associated neurodegenerative disorders: Alzheimer's disease and Parkinson's disease. Lastly, we summarize the TJ aspects of Huntington's disease and schizophrenia. Barrier dysfunction appears to be a common denominator in neurological disorders, warranting detailed research into the molecular mechanisms behind it. Learning the commonalities and differences in the pathomechanism of the BBB injury in different neurological disorders will predictably lead to development of new therapeutics that improve our life as we age.
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Affiliation(s)
- Laura Costea
- Institute of Life Sciences, Vasile Goldiş Western University of Arad, 310414 Arad, Romania.
| | - Ádám Mészáros
- Institute of Biophysics, Biological Research Centre, 6726 Szeged, Hungary.
- Doctoral School of Biology, University of Szeged, 6726 Szeged, Hungary.
| | - Hannelore Bauer
- Department of Biological Sciences, University of Salzburg, 5020 Salzburg, Austria.
| | - Hans-Christian Bauer
- Institute of Tendon and Bone Regeneration, Paracelsus Medical University-Spinal Cord Injury and Tissue Regeneration Center Salzburg, 5020 Salzburg, Austria.
| | - Andreas Traweger
- Institute of Tendon and Bone Regeneration, Paracelsus Medical University-Spinal Cord Injury and Tissue Regeneration Center Salzburg, 5020 Salzburg, Austria.
| | - Imola Wilhelm
- Institute of Life Sciences, Vasile Goldiş Western University of Arad, 310414 Arad, Romania.
- Institute of Biophysics, Biological Research Centre, 6726 Szeged, Hungary.
| | - Attila E Farkas
- Institute of Biophysics, Biological Research Centre, 6726 Szeged, Hungary.
- Department of Physiology, Anatomy and Neuroscience, University of Szeged, 6726 Szeged, Hungary.
| | - István A Krizbai
- Institute of Life Sciences, Vasile Goldiş Western University of Arad, 310414 Arad, Romania.
- Institute of Biophysics, Biological Research Centre, 6726 Szeged, Hungary.
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Bhowmick S, D'Mello V, Caruso D, Wallerstein A, Abdul-Muneer P. Impairment of pericyte-endothelium crosstalk leads to blood-brain barrier dysfunction following traumatic brain injury. Exp Neurol 2019; 317:260-270. [DOI: 10.1016/j.expneurol.2019.03.014] [Citation(s) in RCA: 62] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2019] [Revised: 03/25/2019] [Accepted: 03/25/2019] [Indexed: 01/17/2023]
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Lee TH, Hsieh ST, Chiang HY. Fibronectin inhibitor pUR4 attenuates tumor necrosis factor α-induced endothelial hyperpermeability by modulating β1 integrin activation. J Biomed Sci 2019; 26:37. [PMID: 31096970 PMCID: PMC6521375 DOI: 10.1186/s12929-019-0529-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2018] [Accepted: 05/05/2019] [Indexed: 01/02/2023] Open
Abstract
BACKGROUND The blood-spinal cord barrier (BSCB) is composed of a monolayer of endothelium linked with tight junctions and extracellular matrix (ECM)-rich basement membranes and is surrounded by astrocyte foot processes. Endothelial permeability is regulated by interaction between endothelial cells and ECM proteins. Fibronectin (FN) is a principal ECM component of microvessels. Excessive FN deposition disrupts cell-cell adhesion in fibroblasts through β1 integrin ligation. To determine whether excessive FN deposition contributes to the disruption of endothelial integrity, we used an in vitro model of the endothelial monolayer to investigate whether the FN inhibitor pUR4 prevents FN deposition into the subendothelial matrix and attenuates endothelial leakage. METHODS To correlate the effects of excessive FN accumulation in microvessels on BSCB disruption, spinal nerve ligation-which induces BSCB leakage-was applied, and FN expression in the spinal cord was evaluated through immunohistochemistry and immunoblotting. To elucidate the effects by which pUR4 modulates endothelial permeability, brain-derived endothelial (bEND.3) cells treated with tumor necrosis factor (TNF)-α were used to mimic a leaky BSCB. A bEND.3 monolayer was preincubated with pUR4 before TNF-α treatment. The transendothelial electrical resistance (TEER) measurement and transendothelial permeability assay were applied to assess the endothelial integrity of the bEND.3 monolayer. Immunofluorescence analysis and immunoblotting were performed to evaluate the inhibitory effects of pUR4 on TNF-α-induced FN deposition. To determine the mechanisms underlying pUR4-mediated endothelial permeability, cell morphology, stress fiber formation, myosin light chain (MLC) phosphorylation, and β1 integrin-mediated signaling were evaluated through immunofluorescence analysis and immunoblotting. RESULTS Excessive FN was accumulated in the microvessels of the spinal cord after spinal nerve ligation; moreover, pUR4 inhibited TNF-α-induced FN deposition in the bEND.3 monolayer and maintained intact TEER and endothelial permeability. Furthermore, pUR4 reduced cell morphology alteration, actin stress fiber formation, and MLC phosphorylation, thereby attenuating paracellular gap formation. Moreover, pUR4 reduced β1 integrin activation and downstream signaling. CONCLUSIONS pUR4 reduces TNF-α-induced β1 integrin activation by depleting ECM FN, leading to a decrease in endothelial hyperpermeability and maintenance of monolayer integrity. These findings suggest therapeutic benefits of pUR4 in pathological vascular leakage treatment.
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Affiliation(s)
- Ting-Hein Lee
- Department of Anatomy, College of Medicine, Chang Gung University, 259 Wenhua 1st Rd., Guishan Dist, Taoyuan City, 33302, Taiwan.,Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan.,Division of Cardiology, Department of Internal Medicine, Chang Gung Memorial Hospital, Linkou, Taiwan
| | - Sung-Tsang Hsieh
- Department of Anatomy and Cell Biology, College of Medicine, National Taiwan University, Taipei, Taiwan.,Graduate Institute of Brain and Mind Sciences, College of Medicine, National Taiwan University, Taipei, Taiwan.,Department of Neurology, National Taiwan University Hospital, Taipei, Taiwan
| | - Hou-Yu Chiang
- Department of Anatomy, College of Medicine, Chang Gung University, 259 Wenhua 1st Rd., Guishan Dist, Taoyuan City, 33302, Taiwan. .,Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan. .,Division of Cardiology, Department of Internal Medicine, Chang Gung Memorial Hospital, Linkou, Taiwan.
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42
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Kanazawa M, Takahashi T, Ishikawa M, Onodera O, Shimohata T, Del Zoppo GJ. Angiogenesis in the ischemic core: A potential treatment target? J Cereb Blood Flow Metab 2019; 39:753-769. [PMID: 30841779 PMCID: PMC6501515 DOI: 10.1177/0271678x19834158] [Citation(s) in RCA: 76] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The ischemic penumbra is both a concept in understanding the evolution of cerebral tissue injury outcome of focal ischemia and a potential therapeutic target for ischemic stroke. In this review, we examine the evidence that angiogenesis can contribute to beneficial outcomes following focal ischemia in model systems. Several studies have shown that, following cerebral ischemia, endothelial proliferation and subsequent angiogenesis can be detected beginning four days after cerebral ischemia in the border of the ischemic core, or in the ischemic periphery, in rodent and non-human primate models, although initial signals appear within hours of ischemia onset. Components of the neurovascular unit, its participation in new vessel formation, and the nature of the core and penumbra responses to experimental focal cerebral ischemia, are considered here. The potential co-localization of vascular remodeling and axonal outgrowth following focal cerebral ischemia based on the definition of tissue remodeling and the processes that follow ischemic stroke are also considered. The region of angiogenesis in the ischemic core and its surrounding tissue (ischemic periphery) may be a novel target for treatment. We summarize issues that are relevant to model studies of focal cerebral ischemia looking ahead to potential treatments.
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Affiliation(s)
- Masato Kanazawa
- 1 Department of Neurology, Brain Research Institute, Niigata University, Niigata, Japan
| | - Tetsuya Takahashi
- 1 Department of Neurology, Brain Research Institute, Niigata University, Niigata, Japan
| | - Masanori Ishikawa
- 1 Department of Neurology, Brain Research Institute, Niigata University, Niigata, Japan
| | - Osamu Onodera
- 1 Department of Neurology, Brain Research Institute, Niigata University, Niigata, Japan
| | - Takayoshi Shimohata
- 2 Department of Neurology and Geriatrics, Gifu University Graduate School of Medicine, Gifu, Japan
| | - Gregory J Del Zoppo
- 3 Department of Medicine (Division of Hematology), University of Washington, Seattle, WA, USA.,4 Department of Neurology, University of Washington, Seattle, WA, USA
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43
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Girolamo F, Errede M, Longo G, Annese T, Alias C, Ferrara G, Morando S, Trojano M, Kerlero de Rosbo N, Uccelli A, Virgintino D. Defining the role of NG2-expressing cells in experimental models of multiple sclerosis. A biofunctional analysis of the neurovascular unit in wild type and NG2 null mice. PLoS One 2019; 14:e0213508. [PMID: 30870435 PMCID: PMC6417733 DOI: 10.1371/journal.pone.0213508] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2018] [Accepted: 02/24/2019] [Indexed: 01/09/2023] Open
Abstract
During experimental autoimmune encephalomyelitis (EAE), a model for multiple sclerosis associated with blood-brain barrier (BBB) disruption, oligodendrocyte precursor cells (OPCs) overexpress proteoglycan nerve/glial antigen 2 (NG2), proliferate, and make contacts with the microvessel wall. To explore whether OPCs may actually be recruited within the neurovascular unit (NVU), de facto intervening in its cellular and molecular composition, we quantified by immunoconfocal morphometry the presence of OPCs in contact with brain microvessels, during postnatal cerebral cortex vascularization at postnatal day 6, in wild-type (WT) and NG2 knock-out (NG2KO) mice, and in the cortex of adult naïve and EAE-affected WT and NG2KO mice. As observed in WT mice during postnatal development, a higher number of juxtavascular and perivascular OPCs was revealed in adult WT mice during EAE compared to adult naïve WT mice. In EAE-affected mice, OPCs were mostly associated with microvessels that showed altered claudin-5 and occludin tight junction (TJ) staining patterns and barrier leakage. In contrast, EAE-affected NG2KO mice, which did not show any significant increase in vessel-associated OPCs, seemed to retain better preserved TJs and BBB integrity. As expected, absence of NG2, in both OPCs and pericytes, led to a reduced content of vessel basal lamina molecules, laminin, collagen VI, and collagen IV. In addition, analysis of the major ligand/receptor systems known to promote OPC proliferation and migration indicated that vascular endothelial growth factor A (VEGF-A), platelet-derived growth factor-AA (PDGF-AA), and the transforming growth factor-β (TGF-β) were the molecules most likely involved in proliferation and recruitment of vascular OPCs during EAE. These results were confirmed by real time-PCR that showed Fgf2, Pdgfa and Tgfb expression on isolated cerebral cortex microvessels and by dual RNAscope-immunohistochemistry/in situ hybridization (IHC/ISH), which detected Vegfa and Vegfr2 transcripts on cerebral cortex sections. Overall, this study suggests that vascular OPCs, in virtue of their developmental arrangement and response to neuroinflammation and growth factors, could be integrated among the classical NVU cell components. Moreover, the synchronized activation of vascular OPCs and pericytes during both BBB development and dysfunction, points to NG2 as a key regulator of vascular interactions.
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Affiliation(s)
- Francesco Girolamo
- Department of Basic Medical Sciences, Neurosciences and Sense Organs, University of Bari School of Medicine, Bari, Italy
- * E-mail: (DV); (FG)
| | - Mariella Errede
- Department of Basic Medical Sciences, Neurosciences and Sense Organs, University of Bari School of Medicine, Bari, Italy
| | - Giovanna Longo
- Department of Basic Medical Sciences, Neurosciences and Sense Organs, University of Bari School of Medicine, Bari, Italy
| | - Tiziana Annese
- Department of Basic Medical Sciences, Neurosciences and Sense Organs, University of Bari School of Medicine, Bari, Italy
| | - Carlotta Alias
- B+LabNet—Environmental Sustainability Lab, University of Brescia, Brescia, Italy
| | - Giovanni Ferrara
- Department of Neurosciences, Ophthalmology, Genetics, Rehabilitation and Child Health, University of Genoa, Genoa, Italy
| | - Sara Morando
- Department of Neurosciences, Ophthalmology, Genetics, Rehabilitation and Child Health, University of Genoa, Genoa, Italy
| | - Maria Trojano
- Department of Basic Medical Sciences, Neurosciences and Sense Organs, University of Bari School of Medicine, Bari, Italy
| | - Nicole Kerlero de Rosbo
- Department of Neurosciences, Ophthalmology, Genetics, Rehabilitation and Child Health, University of Genoa, Genoa, Italy
| | - Antonio Uccelli
- Department of Neurosciences, Ophthalmology, Genetics, Rehabilitation and Child Health, University of Genoa, Genoa, Italy
- Center of Excellence for Biomedical Research (CEBR), University of Genoa, Genoa, Italy
- Ospedale Policlinico San Martino–IRCCS, Genoa, Italy
| | - Daniela Virgintino
- Department of Basic Medical Sciences, Neurosciences and Sense Organs, University of Bari School of Medicine, Bari, Italy
- * E-mail: (DV); (FG)
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Nirwane A, Yao Y. Laminins and their receptors in the CNS. Biol Rev Camb Philos Soc 2019; 94:283-306. [PMID: 30073746 DOI: 10.1111/brv.12454] [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: 04/20/2018] [Revised: 07/05/2018] [Accepted: 07/09/2018] [Indexed: 01/24/2023]
Abstract
Laminin, an extracellular matrix protein, is widely expressed in the central nervous system (CNS). By interacting with integrin and non-integrin receptors, laminin exerts a large variety of important functions in the CNS in both physiological and pathological conditions. Due to the existence of many laminin isoforms and their differential expression in various cell types in the CNS, the exact functions of each individual laminin molecule in CNS development and homeostasis remain largely unclear. In this review, we first briefly introduce the structure and biochemistry of laminins and their receptors. Next, the dynamic expression of laminins and their receptors in the CNS during both development and in adulthood is summarized in a cell-type-specific manner, which allows appreciation of their functional redundancy/compensation. Furthermore, we discuss the biological functions of laminins and their receptors in CNS development, blood-brain barrier (BBB) maintenance, neurodegeneration, stroke, and neuroinflammation. Last, key challenges and potential future research directions are summarized and discussed. Our goals are to provide a synthetic review to stimulate future studies and promote the formation of new ideas/hypotheses and new lines of research in this field.
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Affiliation(s)
- Abhijit Nirwane
- Department of Pharmaceutical and Biomedical Sciences, University of Georgia, 240 W Green Street, Athens, GA 30602, U.S.A
| | - Yao Yao
- Department of Pharmaceutical and Biomedical Sciences, University of Georgia, 240 W Green Street, Athens, GA 30602, U.S.A
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45
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Greene C, Hanley N, Campbell M. Claudin-5: gatekeeper of neurological function. Fluids Barriers CNS 2019; 16:3. [PMID: 30691500 PMCID: PMC6350359 DOI: 10.1186/s12987-019-0123-z] [Citation(s) in RCA: 280] [Impact Index Per Article: 56.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2018] [Accepted: 01/11/2019] [Indexed: 02/07/2023] Open
Abstract
Tight junction proteins of the blood–brain barrier are vital for maintaining integrity of endothelial cells lining brain blood vessels. The presence of these protein complexes in the space between endothelial cells creates a dynamic, highly regulated and restrictive microenvironment that is vital for neural homeostasis. By limiting paracellular diffusion of material between blood and brain, tight junction proteins provide a protective barrier preventing the passage of unwanted and potentially damaging material. Simultaneously, this protective barrier hinders the therapeutic effectiveness of central nervous system acting drugs with over 95% of small molecule therapeutics unable to bypass the blood–brain barrier. At the blood–brain barrier, claudin-5 is the most enriched tight junction protein and its dysfunction has been implicated in neurodegenerative disorders such as Alzheimer’s disease, neuroinflammatory disorders such as multiple sclerosis as well as psychiatric disorders including depression and schizophrenia. By regulating levels of claudin-5, it is possible to abrogate disease symptoms in many of these disorders. This review will give an overview of the blood–brain barrier and the role of tight junction complexes in maintaining blood–brain barrier integrity before focusing on the role of claudin-5 and its regulation in homeostatic and pathological conditions. We will also summarise therapeutic strategies to restore integrity of cerebral vessels by targeting tight junction protein complexes.
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Affiliation(s)
- Chris Greene
- Trinity College Dublin, Smurfit Institute of Genetics, Dublin 2, Ireland
| | - Nicole Hanley
- Trinity College Dublin, Smurfit Institute of Genetics, Dublin 2, Ireland
| | - Matthew Campbell
- Trinity College Dublin, Smurfit Institute of Genetics, Dublin 2, Ireland.
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46
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Halder SK, Kant R, Milner R. Chronic mild hypoxia increases expression of laminins 111 and 411 and the laminin receptor α6β1 integrin at the blood-brain barrier. Brain Res 2018; 1700:78-85. [PMID: 30006296 PMCID: PMC6231956 DOI: 10.1016/j.brainres.2018.07.012] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2018] [Revised: 07/05/2018] [Accepted: 07/09/2018] [Indexed: 11/23/2022]
Abstract
The laminin family of glycoproteins are major constituents of the basal lamina of blood vessels, and play a fundamental role in promoting endothelial differentiation and blood-brain barrier (BBB) stability. Chronic mild hypoxia (CMH), in which mice are exposed to 8% O2 for two weeks, induces a strong vascular remodeling response in the central nervous system (CNS) that includes endothelial proliferation, angiogenesis, arteriogenesis as well as increased expression of tight junction proteins, suggestive of enhanced vascular integrity. As previous studies highlight an important role for laminin in promoting vascular differentiation and BBB stability, the goal of this study was to determine if CMH influences the expression of the laminins and their cell surface receptors in cerebral blood vessels. Our studies revealed that over a 14 day period of CMH, blood vessels in the brain showed strong upregulation of the specific laminin subunits α1 and α4, corresponding to increased expression of laminins 111 and 411 respectively, with no discernible changes in the expression levels of the α2 or α5 laminin subunits. This was accompanied by marked endothelial upregulation of the laminin receptor α6β1 integrin but no alterations in the other laminin receptors α1β1 integrin or dystroglycan. In light of the instructive role for laminins in promoting vascular differentiation and stability, these data suggest that upregulation of the laminin-α6β1 integrin axis is part of the molecular response triggered by mild hypoxia that leads to enhanced BBB stability.
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Affiliation(s)
- Sebok K Halder
- Department of Molecular Medicine, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, United States.
| | - Ravi Kant
- Department of Molecular Medicine, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, United States.
| | - Richard Milner
- Department of Molecular Medicine, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, United States.
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47
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Edwards DN, Bix GJ. Roles of blood-brain barrier integrins and extracellular matrix in stroke. Am J Physiol Cell Physiol 2018; 316:C252-C263. [PMID: 30462535 DOI: 10.1152/ajpcell.00151.2018] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Ischemicstroke is a leading cause of death and disability in the United States, but recent advances in treatments [i.e., endovascular thrombectomy and tissue plasminogen activator (t-PA)] that target the stroke-causing blood clot, while improving overall stroke mortality rates, have had much less of an impact on overall stroke morbidity. This may in part be attributed to the lack of therapeutics targeting reperfusion-induced injury after the blood clot has been removed, which, if left unchecked, can expand injury from its core into the surrounding at risk tissue (penumbra). This occurs in two phases of increased permeability of the blood-brain barrier, a physical barrier that under physiologic conditions regulates brain influx and efflux of substances and consists of tight junction forming endothelial cells (and transporter proteins), astrocytes, pericytes, extracellular matrix, and their integrin cellular receptors. During, embryonic development, maturity, and following stroke reperfusion, cerebral vasculature undergoes significant changes including changes in expression of integrins and degradation of surrounding extracellular matrix. Integrins, heterodimers with α and β subunits, and their extracellular matrix ligands, a collection of proteoglycans, glycoproteins, and collagens, have been modestly studied in the context of stroke compared with other diseases (e.g., cancer). In this review, we describe the effect that various integrins and extracellular matrix components have in embryonic brain development, and how this changes in both maturity and in the poststroke environment. Particular focus will be on how these changes in integrins and the extracellular matrix affect blood-brain barrier components and their potential as diagnostic and therapeutic targets for ischemic stroke.
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Affiliation(s)
- Danielle N Edwards
- Sanders-Brown Center on Aging, University of Kentucky , Lexington, Kentucky.,Department of Neuroscience, University of Kentucky , Lexington, Kentucky
| | - Gregory J Bix
- Sanders-Brown Center on Aging, University of Kentucky , Lexington, Kentucky.,Department of Neuroscience, University of Kentucky , Lexington, Kentucky.,Department of Neurology, University of Kentucky , Lexington, Kentucky.,Department of Neurosurgery, University of Kentucky , Lexington, Kentucky
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48
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Labus J, Wöltje K, Stolte KN, Häckel S, Kim KS, Hildmann A, Danker K. IL-1β promotes transendothelial migration of PBMCs by upregulation of the FN/α 5β 1 signalling pathway in immortalised human brain microvascular endothelial cells. Exp Cell Res 2018; 373:99-111. [PMID: 30342992 DOI: 10.1016/j.yexcr.2018.10.002] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2018] [Revised: 09/29/2018] [Accepted: 10/05/2018] [Indexed: 02/06/2023]
Abstract
Neuroinflammation is often associated with pathological changes in the function of the blood-brain barrier (BBB) caused by disassembly of tight and adherens junctions that under physiological conditions are important for the maintenance of the BBB integrity. Consequently, in inflammation the BBB becomes dysfunctional, facilitating leukocyte traversal of the barrier and accumulation of immune cells within the brain. The extracellular matrix (ECM) also contributes to BBB integrity but the significance of the main ECM receptors, the β1 integrins also expressed on endothelial cells, is less well understood. To evaluate whether β1 integrin function is affected during inflammation and impacts barrier function, we used a transformed human brain microvascular endothelial cell (THBMEC)-based Interleukin 1β (IL-1β)-induced inflammatory in vitro BBB model. We demonstrate that IL-1β increases cell-matrix adhesion and induces a redistribution of active β1 integrins to the basal surface. In particular, binding of α5β1 integrin to its ligand fibronectin is enhanced and α5β1 integrin-dependent signalling is upregulated. Additionally, localisation of the tight junction protein claudin-5 is altered. Blockade of the α5β1 integrin reduces the IL-1β-induced transendothelial migration of peripheral blood mononuclear cells (PBMCs). These data imply that IL-1β-induced inflammation not only destabilizes tight junctions but also increases α5β1 integrin-dependent cell-matrix adhesion to fibronectin.
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Affiliation(s)
- Josephine Labus
- Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Institute of Biochemistry, Charitéplatz 1, 10117 Berlin, Germany
| | - Kerstin Wöltje
- Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Institute of Biochemistry, Charitéplatz 1, 10117 Berlin, Germany
| | - Kim Natalie Stolte
- Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Institute of Biochemistry, Charitéplatz 1, 10117 Berlin, Germany
| | - Sonja Häckel
- Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Institute of Biochemistry, Charitéplatz 1, 10117 Berlin, Germany
| | - Kwang Sik Kim
- Division of Pediatric Infectious Diseases, Johns Hopkins University School of Medicine, 200 North Wolfe Street, 21287 Baltimore, USA
| | - Annette Hildmann
- Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Institute of Biochemistry, Charitéplatz 1, 10117 Berlin, Germany
| | - Kerstin Danker
- Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Institute of Biochemistry, Charitéplatz 1, 10117 Berlin, Germany.
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Halder SK, Kant R, Milner R. Hypoxic pre-conditioning suppresses experimental autoimmune encephalomyelitis by modifying multiple properties of blood vessels. Acta Neuropathol Commun 2018; 6:86. [PMID: 30176931 PMCID: PMC6122733 DOI: 10.1186/s40478-018-0590-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2018] [Accepted: 08/27/2018] [Indexed: 12/26/2022] Open
Abstract
While hypoxic pre-conditioning protects against neurological disease the underlying mechanisms have yet to be fully defined. As chronic mild hypoxia (CMH, 10% O2) triggers profound vascular remodeling in the central nervous system (CNS), the goal of this study was to examine the protective potential of hypoxic pre-conditioning in the experimental autoimmune encephalomyelitis (EAE) model of multiple sclerosis (MS) and then determine how CMH influences vascular integrity and the underlying cellular and molecular mechanisms during EAE. We found that mice exposed to CMH at the same time as EAE induction were strongly protected against the development of EAE progression, as assessed both at the clinical level and at the histopathological level by reduced levels of inflammatory leukocyte infiltration, vascular breakdown and demyelination. Mechanistically, our studies indicate that CMH protects, at least in part, by enhancing several properties of blood vessels that contribute to vascular integrity, including reduced expression of the endothelial activation molecules VCAM-1 and ICAM-1, maintained expression of endothelial tight junction proteins ZO-1 and occludin, and upregulated expression of the leukocyte inhibitory protein laminin-111 in the vascular basement membrane. Taken together, these data suggest that optimization of BBB integrity is an important mechanism underlying the protective effect of hypoxic pre-conditioning.
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50
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Noumbissi ME, Galasso B, Stins MF. Brain vascular heterogeneity: implications for disease pathogenesis and design of in vitro blood-brain barrier models. Fluids Barriers CNS 2018; 15:12. [PMID: 29688865 PMCID: PMC5911972 DOI: 10.1186/s12987-018-0097-2] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2018] [Accepted: 04/13/2018] [Indexed: 12/22/2022] Open
Abstract
The vertebrate blood–brain barrier (BBB) is composed of cerebral microvascular endothelial cells (CEC). The BBB acts as a semi-permeable cellular interface that tightly regulates bidirectional molecular transport between blood and the brain parenchyma in order to maintain cerebral homeostasis. The CEC phenotype is regulated by a variety of factors, including cells in its immediate environment and within functional neurovascular units. The cellular composition of the brain parenchyma surrounding the CEC varies between different brain regions; this difference is clearly visible in grey versus white matter. In this review, we discuss evidence for the existence of brain vascular heterogeneity, focusing on differences between the vessels of the grey and white matter. The region-specific differences in the vasculature of the brain are reflective of specific functions of those particular brain areas. This BBB-endothelial heterogeneity may have implications for the course of pathogenesis of cerebrovascular diseases and neurological disorders involving vascular activation and dysfunction. This heterogeneity should be taken into account when developing BBB-neuro-disease models representative of specific brain areas.
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Affiliation(s)
- Midrelle E Noumbissi
- Malaria Research Institute, Dept. Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, 615 N. Wolfe Street, SPH East 4135, Baltimore, MD, 21205, USA
| | - Bianca Galasso
- Malaria Research Institute, Dept. Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, 615 N. Wolfe Street, SPH East 4135, Baltimore, MD, 21205, USA
| | - Monique F Stins
- Malaria Research Institute, Dept. Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, 615 N. Wolfe Street, SPH East 4135, Baltimore, MD, 21205, USA.
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