scholarly journals Role of Intermediate Filaments in Blood–Brain Barrier in Health and Disease

Cells ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1400
Author(s):  
Ece Bayir ◽  
Aylin Sendemir
Keyword(s):  
Endothelial Cells ◽  
Blood Brain Barrier ◽  
Intermediate Filaments ◽  
Intermediate Filament ◽  
Cell Junctions ◽  
Brain Barrier ◽  
Blood Brain ◽  
Health And Disease ◽  
Bbb Permeability ◽  
Cell Cell

The blood–brain barrier (BBB) is a highly selective cellular monolayer unique to the microvasculature of the central nervous system (CNS), and it mediates the communication of the CNS with the rest of the body by regulating the passage of molecules into the CNS microenvironment. Limitation of passage of substances through the BBB is mainly due to tight junctions (TJ) and adherens junctions (AJ) between brain microvascular endothelial cells. The importance of actin filaments and microtubules in establishing and maintaining TJs and AJs has been indicated; however, recent studies have shown that intermediate filaments are also important in the formation and function of cell–cell junctions. The most common intermediate filament protein in endothelial cells is vimentin. Vimentin plays a role in blood–brain barrier permeability in both cell–cell and cell–matrix interactions by affecting the actin and microtubule reorganization and by binding directly to VE-cadherin or integrin proteins. The BBB permeability increases due to the formation of stress fibers and the disruption of VE–cadherin interactions between two neighboring cells in various diseases, disrupting the fiber network of intermediate filament vimentin in different ways. Intermediate filaments may be long ignored key targets in regulation of BBB permeability in health and disease.

scholarly journals Brain Endothelial Cell-Cell Junctions: How to “Open” the Blood Brain Barrier

2008 ◽  
Vol 6 (3) ◽  
pp. 179-192 ◽  
Author(s):  
Svetlana Stamatovic ◽  
Richard Keep ◽  
Anuska Andjelkovic
Keyword(s):  
Endothelial Cell ◽  
Blood Brain Barrier ◽  
Cell Junctions ◽  
Brain Barrier ◽  
Brain Endothelial Cell ◽  
Blood Brain ◽  
Cell Cell

EXTH-17. A FOCUSED ULTRASOUND BLOOD BRAIN BARRIER DISRUPTION MODEL TO TEST THE INFLUENCE OF TIGHT JUNCTION GENES TO TREAT BRAIN TUMORS

2021 ◽  
Vol 23 (Supplement_6) ◽  
pp. vi167-vi167
Author(s):  
Jayashree Iyer ◽  
Adam Akkad ◽  
Nanyun Tang ◽  
Michael Berens ◽  
Frederic Zenhausern ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Tight Junction ◽  
Blood Brain Barrier ◽  
Focused Ultrasound ◽  
Cell Junctions ◽  
Brain Barrier ◽  
Western Blots ◽  
Protective Function ◽  
Blood Brain ◽  
On Chip

Abstract Treating primary or metastatic tumors in the brain (glioblastomas, melanoma, lung cancer, breast cancer) proves challenging by virtue of the protective function of the blood brain barrier (BBB). The tight junction proteins (TJPs) binding the specialized endothelial cells of the BBB largely contribute to the limited permeability of cancer-therapeutic drugs. In both preclinical and clinical models, low intensity focused ultrasound (LIFU) coupled with microbubbles has been proven to safely and transiently open the BBB. Despite this method being established, potential genetic influences on the durability and vulnerability of tight junctions to LIFU have not been elucidated, nor have the determinants of tight junction repair post LIFU been thoroughly investigated. We report the development of an ultrasound transparent organ-on-chip model populated by iPSC-derived endothelial cells (iPSC-EC) co-cultured with astrocytes. We aim to probe the contributions of various tight junction genes to barrier integrity along with the subsequent protein topology involved in reassembly post ultrasound. Thus, this model serves to determine parameters for ultrasound disruption for precision opening of the BBB. The BBB-On-Chip was successfully fabricated and assembled with an optimized technique that has an 80% yield of leak-free devices, with stable cavitation post nanobubble injection. Furthermore, Western blots show expression of claudin-5, a key TJP, in our iPSC-ECs. We have also demonstrated by confocal microscopy that another component of the TJP complex, ZO-1, can be visualized at iPSC-derived cell junctions. Further benchmarking of device-ultrasound interactions, successful iPSC differentiation, tight junction formation, and fabrication of nanobubbles and their assistance in ultrasound BBB disruption will be presented. Efforts are underway to characterize the contributions of tight junction genes and their variations to the integrity and disruption of the BBB.

scholarly journals Apolipoprotein M-bound sphingosine-1-phosphate regulates blood-brain barrier paracellular permeability and transcytosis

2019 ◽  
Author(s):  
Mette Mathiesen Janiurek ◽  
Christina Christoffersen ◽  
Krzysztof Kucharz ◽  
Martin Lauritzen
Keyword(s):  
Endothelial Cells ◽  
Small Molecules ◽  
Blood Brain Barrier ◽  
Structural Changes ◽  
Brain Barrier ◽  
Cerebral Microvessels ◽  
Apolipoprotein M ◽  
Blood Brain ◽  
Sphingosine 1 Phosphate ◽  
Bbb Permeability

ABTRACTThe blood-brain barrier (BBB) is formed by the endothelial cells lining cerebral microvessels. Here, we report that the BBB permeability is modified by apolipoprotein M (apoM)-bound sphingosine 1-phosphate (S1P). We used two-photon microscopy to monitor changes in BBB permeability in apoM-deficient mice (apoM−/−), showing significant increases in paracellular BBB permeability to small molecules without structural changes in junctional complexes between endothelial cells. Lack of apoM-bound S1P increased vesicle-mediated transfer of albumin across endothelium of brain pial and penetrating arterioles, whereas transcytosis in capillaries and venules remained unchanged. S1PR1 agonist SEW2871 rapidly normalized BBB permeability along both the paracellular and transcellular routes in apoM−/− mice. Thus, apoM-bound S1P maintains low paracellular BBB permeability for small molecules in all cerebral microvessels and low levels of adsorptive transcytosis in penetrating arterioles. Modulation of apoM/S1P-dependent signaling may be a novel strategy for the protection of brain endothelial cells to preserve the BBB function.

scholarly journals Endothelium-Macrophage Crosstalk Mediates Blood-Brain Barrier Dysfunction in Hypertension

Hypertension ◽  
2020 ◽  
Vol 76 (3) ◽  
pp. 795-807 ◽  
Author(s):  
Monica M. Santisteban ◽  
Sung Ji Ahn ◽  
Diane Lane ◽  
Giuseppe Faraco ◽  
Lidia Garcia-Bonilla ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Blood Brain Barrier ◽  
Cooperative Interaction ◽  
Brain Barrier ◽  
Viral Gene ◽  
Ang Ii ◽  
Barrier Dysfunction ◽  
Cerebral Microvessels ◽  
Blood Brain ◽  
Bbb Permeability

Hypertension is a leading cause of stroke and dementia, effects attributed to disrupting delivery of blood flow to the brain. Hypertension also alters the blood-brain barrier (BBB), a critical component of brain health. Although endothelial cells are ultimately responsible for the BBB, the development and maintenance of the barrier properties depend on the interaction with other vascular-associated cells. However, it remains unclear if BBB disruption in hypertension requires cooperative interaction with other cells. Perivascular macrophages (PVM), innate immune cells closely associated with cerebral microvessels, have emerged as major contributors to neurovascular dysfunction. Using 2-photon microscopy in vivo and electron microscopy in a mouse model of Ang II (angiotensin II) hypertension, we found that the vascular segments most susceptible to increased BBB permeability are arterioles and venules >10 µm and not capillaries. Brain macrophage depletion with clodronate attenuates, but does not abolish, the increased BBB permeability in these arterioles where PVM are located. Deletion of AT1R (Ang II type-1 receptors) in PVM using bone marrow chimeras partially attenuated the BBB dysfunction through the free radical-producing enzyme Nox2. In contrast, downregulation of AT1R in cerebral endothelial cells using a viral gene transfer-based approach prevented the BBB disruption completely. The results indicate that while endothelial AT1R, mainly in arterioles and venules, initiate the BBB disruption in hypertension, PVM are required for the full expression of the dysfunction. The findings unveil a previously unappreciated contribution of resident brain macrophages to increased BBB permeability of hypertension and identify PVM as a putative therapeutic target in diseases associated with BBB dysfunction.

scholarly journals Neurothelin: an inducible cell surface glycoprotein of blood-brain barrier-specific endothelial cells and distinct neurons.

1990 ◽  
Vol 110 (4) ◽  
pp. 1261-1274 ◽  
Author(s):  
B Schlosshauer ◽  
K H Herzog
Keyword(s):  
Endothelial Cells ◽  
Cell Surface ◽  
Blood Brain Barrier ◽  
Vascular System ◽  
Chorioallantoic Membrane ◽  
Neural Tissue ◽  
Brain Barrier ◽  
Chick Chorioallantoic Membrane ◽  
Blood Brain ◽  
Cell Cell

The blood-brain barrier is characterized by still poorly understood barrier and transport functions performed by specialized endothelial cells. Hybridoma technology has been used to identify a protein termed neurothelin that is specific for these endothelial cells. Neurothelin is defined by the species-specific mouse mAb 1W5 raised against lentil-lectin-binding proteins of neural tissue from embryonic chick. In the posthatch chick, neurothelin expression is found on endothelial cells within the brain but not on those of the systemic vascular system. Injection of the monoclonal antibody in vivo leads to labeling of brain capillaries, indicating that the corresponding antigen is expressed on the luminal surface of brain endothelial cells. Transplantation of embryonic mouse brain onto the chick chorioallantoic membrane results in rodent brain vascularization by the avian vascular system. Subsequently, normally mAb 1W5-negative endothelial cells, originating from blood vessels of the chick chorioallantoic membrane, are induced to express neurothelin when they are in contact with mouse neural tissue. In contrast to differentiated brain neurons that do not express neurothelin, neurons of the nonvascularized chick retina synthesize neurothelin. However, neurothelin is not found on retinal ganglion cell axons terminating on 1W5-negative brain cells. 1W5 immunoreactivity was also found in the pigment epithelium that forms the blood-eye barrier. Putting epithelial cells into culture results in concentration of neurothelin at cell-cell contact sites, leaving other cell surface areas devoid of antigen. Therefore, the distribution of neurothelin appears to be regulated by cell-cell interactions. In Western blot analysis, neurothelin was identified as a protein with a molecular mass of approximately 43 kD. The protein bears at least one intramolecular disulfide bridge and sulfated glucuronic acid as well as alpha-D-substituted mannose/glucose moieties. The exclusive neurothelin expression in the posthatch chick on endothelial cells of the central nervous system but not on systemic endothelial cells makes neurothelin a marker specific for blood-brain barrier-forming endothelial cells. The spatiotemporally regulated neurothelin expression in neurons suggests an interaction between vascularization and neuronal differentiation.

scholarly journals Reversible blood-brain barrier opening utilizing the membrane active peptide melittin in vitro and in vivo

2021 ◽  
Author(s):  
Raleigh M. Linville ◽  
Alexander Komin ◽  
Xiaoyan Lan ◽  
Jackson G. DeStefano ◽  
Chengyan Chu ◽  
...  
Keyword(s):  
Blood Brain Barrier ◽  
Cell Junctions ◽  
Brain Barrier ◽  
Active Peptide ◽  
Blood Brain ◽  
Barrier Opening ◽  
The Brain ◽  
Blood Brain Barrier Opening ◽  
Cell Cell

AbstractThe blood-brain barrier (BBB) tightly controls entry of molecules and cells into the brain, restricting the delivery of therapeutics. Blood-brain barrier opening (BBBO) utilizes reversible disruption of cell-cell junctions between brain microvascular endothelial cells to enable transient entry into the brain. Development of BBBO techniques has been hindered by a lack of physiological models for in vitro study. Here, we utilize an in vitro tissue-engineered microvessel model to demonstrate that melittin, a membrane active peptide present in bee venom, supports BBBO. From endothelial and neuronal viability studies, we identify the accessible concentration range for BBBO. We then use a tissue-engineered model of the human BBB to optimize dosing and elucidate the mechanism of opening. Melittin and other membrane active variants transiently increase paracellular permeability via disruption of cell-cell junctions. In mice, we demonstrate a minimum clinically effective intra-arterial dose of 3 μM·min melittin, which is reversible within one day and neurologically safe. Melittin-induced BBBO represents a novel platform for delivery of therapeutics into the brain.

scholarly journals Activation of Frizzled-7 attenuates blood–brain barrier disruption through Dvl/β-catenin/WISP1 signaling pathway after intracerebral hemorrhage in mice

2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Wei He ◽  
Qin Lu ◽  
Prativa Sherchan ◽  
Lei Huang ◽  
Xin Hu ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Intracerebral Hemorrhage ◽  
Signaling Pathway ◽  
Brain Edema ◽  
Blood Brain Barrier ◽  
Neurological Function ◽  
Brain Barrier ◽  
Secondary Brain Injury ◽  
Blood Brain ◽  
Bbb Permeability

Abstract Background Destruction of blood–brain barrier (BBB) ​​is one of the main mechanisms of secondary brain injury following intracerebral hemorrhage (ICH). Frizzled-7 is a key protein expressed on the surface of endothelial cells that controls vascular permeability through the Wnt-canonical pathway involving WNT1-inducible signaling pathway protein 1 (WISPI). This study aimed to investigate the role of Frizzled-7 signaling in BBB preservation after ICH in mice. Methods Adult CD1 mice were subjected to sham surgery or collagenase-induced ICH. Frizzled-7 activation or knockdown was performed by administration of Clustered Regularly Interspaced Palindromic Repeats (CRISPR) by intracerebroventricular injection at 48 h before ICH induction. WISP1 activation or WISP1 knockdown was performed to evaluate the underlying signaling pathway. Post-ICH assessments included neurobehavior, brain edema, BBB permeability, hemoglobin level, western blot and immunofluorescence. Results The brain expressions of Frizzled-7 and WISP1 significantly increased post-ICH. Frizzled-7 was expressed in endothelial cells, astrocytes, and neurons after ICH. Activation of Frizzled-7 significantly improved neurological function, reduced brain water content and attenuated BBB permeability to large molecular weight substances after ICH. Whereas, knockdown of Frizzled-7 worsened neurological function and brain edema after ICH. Activation of Frizzled-7 significantly increased the expressions of Dvl, β-Catenin, WISP1, VE-Cadherin, Claudin-5, ZO-1 and reduced the expression of phospho-β-Catenin. WISP1 knockdown abolished the effects of Frizzled-7 activation on the expressions of VE-Cadherin, Claudin-5 and ZO-1 at 24 h after ICH. Conclusions Frizzled-7 activation potentially attenuated BBB permeability and improved neurological deficits after ICH through Dvl​​/β-Catenin/WISP1 pathway. Frizzled-7 may be a potential target for the development of ICH therapeutic drugs.

scholarly journals Screening for Interacting Proteins with Peptide Biomarker of Blood–Brain Barrier Alteration under Inflammatory Conditions

2021 ◽  
Vol 22 (9) ◽  
pp. 4725
Author(s):  
Karina Vargas-Sanchez ◽  
Monica Losada-Barragán ◽  
Maria Mogilevskaya ◽  
Susana Novoa-Herrán ◽  
Yehidi Medina ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Blood Brain Barrier ◽  
Neurovascular Unit ◽  
Specific Interaction ◽  
Brain Barrier ◽  
Mass Spectrometry Analysis ◽  
Peptide Ligand ◽  
Inflammatory Conditions ◽  
Blood Brain ◽  
Potential Biomarker

Neurodegenerative diseases are characterized by increased permeability of the blood–brain barrier (BBB) due to alterations in cellular and structural components of the neurovascular unit, particularly in association with neuroinflammation. A previous screening study of peptide ligands to identify molecular alterations of the BBB in neuroinflammation by phage-display, revealed that phage clone 88 presented specific binding affinity to endothelial cells under inflammatory conditions in vivo and in vitro. Here, we aimed to identify the possible target receptor of the peptide ligand 88 expressed under inflammatory conditions. A cross-link test between phage-peptide-88 with IL-1β-stimulated human hCMEC cells, followed by mass spectrometry analysis, was used to identify the target of peptide-88. We modeled the epitope–receptor molecular interaction between peptide-88 and its target by using docking simulations. Three proteins were selected as potential target candidates and tested in enzyme-linked immunosorbent assays with peptide-88: fibronectin, laminin subunit α5 and laminin subunit β-1. Among them, only laminin subunit β-1 presented measurable interaction with peptide-88. Peptide-88 showed specific interaction with laminin subunit β-1, highlighting its importance as a potential biomarker of the laminin changes that may occur at the BBB endothelial cells under pathological inflammation conditions.

scholarly journals Dual Roles of Astrocyte-Derived Factors in Regulation of Blood-Brain Barrier Function after Brain Damage

2019 ◽  
Vol 20 (3) ◽  
pp. 571 ◽  
Author(s):  
Shotaro Michinaga ◽  
Yutaka Koyama
Keyword(s):  
Brain Damage ◽  
Blood Brain Barrier ◽  
Brain Barrier ◽  
Blood Brain ◽  
Secondary Damage ◽  
The Central Nervous System ◽  
Bbb Permeability ◽  
Novel Therapeutic Strategies ◽  
Glial Derived Neurotrophic Factor ◽  
Endothelial Growth Factors

The blood-brain barrier (BBB) is a major functional barrier in the central nervous system (CNS), and inhibits the extravasation of intravascular contents and transports various essential nutrients between the blood and the brain. After brain damage by traumatic brain injury, cerebral ischemia and several other CNS disorders, the functions of the BBB are disrupted, resulting in severe secondary damage including brain edema and inflammatory injury. Therefore, BBB protection and recovery are considered novel therapeutic strategies for reducing brain damage. Emerging evidence suggests key roles of astrocyte-derived factors in BBB disruption and recovery after brain damage. The astrocyte-derived vascular permeability factors include vascular endothelial growth factors, matrix metalloproteinases, nitric oxide, glutamate and endothelin-1, which enhance BBB permeability leading to BBB disruption. By contrast, the astrocyte-derived protective factors include angiopoietin-1, sonic hedgehog, glial-derived neurotrophic factor, retinoic acid and insulin-like growth factor-1 and apolipoprotein E which attenuate BBB permeability resulting in recovery of BBB function. In this review, the roles of these astrocyte-derived factors in BBB function are summarized, and their significance as therapeutic targets for BBB protection and recovery after brain damage are discussed.

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