scholarly journals Genetic disruption of the Blood Brain Barrier leads to protective barrier formation at the Glia Limitans

2020 ◽  
Author(s):  
Pierre-Louis Hollier ◽  
Sarah Guimbal ◽  
Pierre Mora ◽  
Aïssata Diop ◽  
Lauriane Cornuault ◽  
...  
Keyword(s):  
Multiple Sclerosis ◽  
Tight Junction ◽  
Blood Brain Barrier ◽  
Treatment Strategies ◽  
Brain Barrier ◽  
Double Barrier ◽  
Cns Inflammation ◽  
Glia Limitans ◽  
Inflammatory Conditions ◽  
Blood Brain

AbstractRecent work demonstrated that Central Nervous System (CNS) inflammation induces endothelial Blood Brain Barrier (BBB) opening as well as the formation of a tight junction barrier between reactive astrocytes at the Glia Limitans. We hypothesized that these two barriers may be reciprocally regulated by each other state and further, that the CNS parenchyma may acquire protection from the reactive astrocytic Glia Limitans not only in neuro-inflammation but also when BBB integrity is compromised under resting condition, without pathology. Previous studies identified Sonic hedgehog (Shh) astrocytic secretion as implicated in stabilizing the BBB during neuropathology and we recently demonstrated that desert hedgehog (Dhh) is expressed at the BBB in adults.Here we unraveled the role of the morphogen Dhh in maintaining BBB tightness and, using endothelial Dhh knockdown as a model of permeable BBB, we demonstrated that a double barrier system comprising both the BBB and Glia Limitans, is implemented in the CNS and regulated by a crosstalk going from endothelial cell to astrocytes.First, we showed that, under neuro-inflammatory conditions, Dhh expression is severely down regulated at the BBB and that Dhh is necessary for endothelial intercellular junction integrity as Dhh knockdown leads to CNS vascular leakage. We then demonstrated that, in Dhh endothelial knockout (DhhECKO) mice which display an open BBB, astrocytes are reactive and express the tight junction Claudin 4 (Cldn4) and showed that astrocytes can respond to signals secreted by the permeable endothelial BBB by becoming reactive and expressing Cldn4. To examine the consequences of the above results on disease severity, we finally induced multiple sclerosis in DhhECKO mice versus control littermates and showed that the pathology is less severe in the knockout animals due to Glia Limitans tightening, in response to BBB leakage, which drives inflammatory infiltrate entrapment into the perivascular space. Altogether these results suggest that genetic disruption of the BBB generates endothelial signals capable of driving the implementation of a secondary barrier at the Glia Limitans to protect the parenchyma. The concept of a reciprocally regulated CNS double barrier system has implications for treatment strategies in both the acute and chronic phases of multiple sclerosis pathophysiology.

scholarly journals Human Brain Endothelial CXCR2 is Inflammation-Inducible and Mediates CXCL5- and CXCL8-Triggered Paraendothelial Barrier Breakdown

2019 ◽  
Vol 20 (3) ◽  
pp. 602 ◽  
Author(s):  
Axel Haarmann ◽  
Michael Schuhmann ◽  
Christine Silwedel ◽  
Camelia-Maria Monoranu ◽  
Guido Stoll ◽  
...  
Keyword(s):  
Multiple Sclerosis ◽  
Tight Junction ◽  
Human Brain ◽  
Blood Brain Barrier ◽  
Barrier Function ◽  
Morphological Changes ◽  
Brain Barrier ◽  
Microvascular Endothelial Cell ◽  
Inflammatory Conditions ◽  
Blood Brain

Chemokines (C-X-C) motif ligand (CXCL) 5 and 8 are overexpressed in patients with multiple sclerosis, where CXCL5 serum levels were shown to correlate with blood–brain barrier dysfunction as evidenced by gadolinium-enhanced magnetic resonance imaging. Here, we studied the potential role of CXCL5/CXCL8 receptor 2 (CXCR2) as a regulator of paraendothelial brain barrier function, using the well-characterized human cerebral microvascular endothelial cell line hCMEC/D3. Low basal CXCR2 mRNA and protein expression levels in hCMEC/D3 were found to strongly increase under inflammatory conditions. Correspondingly, immunohistochemistry of brain biopsies from two patients with active multiple sclerosis revealed upregulation of endothelial CXCR2 compared to healthy control tissue. Recombinant CXCL5 or CXCL8 rapidly and transiently activated Akt/protein kinase B in hCMEC/D3. This was followed by a redistribution of tight junction-associated protein zonula occludens-1 (ZO-1) and by the formation of actin stress fibers. Functionally, these morphological changes corresponded to a decrease of paracellular barrier function, as measured by a real-time electrical impedance-sensing system. Importantly, preincubation with the selective CXCR2 antagonist SB332235 partially prevented chemokine-induced disturbance of both tight junction morphology and function. We conclude that human brain endothelial CXCR2 may contribute to blood–brain barrier disturbance under inflammatory conditions with increased CXCL5 and CXCL8 expression, where CXCR2 may also represent a novel pharmacological target for blood–brain barrier stabilization.

scholarly journals Blood–brain barrier genetic disruption leads to protective barrier formation at the Glia Limitans

PLoS Biology ◽  
2020 ◽  
Vol 18 (11) ◽  
pp. e3000946
Author(s):  
Pierre Mora ◽  
Pierre-Louis Hollier ◽  
Sarah Guimbal ◽  
Alice Abelanet ◽  
Aïssata Diop ◽  
...  
Keyword(s):  
Multiple Sclerosis ◽  
Blood Brain Barrier ◽  
Resting State ◽  
Brain Barrier ◽  
Protective Effects ◽  
Cns Inflammation ◽  
Glia Limitans ◽  
Protective Barrier ◽  
Blood Brain ◽  
Bbb Opening

Inflammation of the central nervous system (CNS) induces endothelial blood–brain barrier (BBB) opening as well as the formation of a tight junction barrier between reactive astrocytes at the Glia Limitans. We hypothesized that the CNS parenchyma may acquire protection from the reactive astrocytic Glia Limitans not only during neuroinflammation but also when BBB integrity is compromised in the resting state. Previous studies found that astrocyte-derived Sonic hedgehog (SHH) stabilizes the BBB during CNS inflammatory disease, while endothelial-derived desert hedgehog (DHH) is expressed at the BBB under resting conditions. Here, we investigated the effects of endothelial Dhh on the integrity of the BBB and Glia Limitans. We first characterized DHH expression within endothelial cells at the BBB, then demonstrated that DHH is down-regulated during experimental autoimmune encephalomyelitis (EAE). Using a mouse model in which endothelial Dhh is inducibly deleted, we found that endothelial Dhh both opens the BBB via the modulation of forkhead box O1 (FoxO1) transcriptional activity and induces a tight junctional barrier at the Glia Limitans. We confirmed the relevance of this glial barrier system in human multiple sclerosis active lesions. These results provide evidence for the novel concept of “chronic neuroinflammatory tolerance” in which BBB opening in the resting state is sufficient to stimulate a protective barrier at the Glia Limitans that limits the severity of subsequent neuroinflammatory disease. In summary, genetic disruption of the BBB generates endothelial signals that drive the formation under resting conditions of a secondary barrier at the Glia Limitans with protective effects against subsequent CNS inflammation. The concept of a reciprocally regulated CNS double barrier system has implications for treatment strategies in both the acute and chronic phases of multiple sclerosis pathophysiology.

Neurofilament levels are associated with blood–brain barrier integrity, lymphocyte extravasation, and risk factors following the first demyelinating event in multiple sclerosis

2020 ◽  
pp. 135245852091237 ◽  
Author(s):  
Tomas Uher ◽  
Mason McComb ◽  
Shery Galkin ◽  
Barbora Srpova ◽  
Johanna Oechtering ◽  
...  
Keyword(s):  
Risk Factors ◽  
Multiple Sclerosis ◽  
Blood Brain Barrier ◽  
Immune Cell ◽  
Disease Onset ◽  
Cell Subset ◽  
Immunoglobulin M ◽  
Brain Barrier ◽  
Cns Inflammation ◽  
Blood Brain

Background: Increased blood brain barrier (BBB) permeability, CNS inflammation and neuroaxonal damage are pathological hallmarks in early multiple sclerosis (MS). Objective: To investigate the associations of neurofilament light chain (NfL) levels with measures of BBB integrity and central nervous system (CNS) inflammation in MS during the first demyelinating event. Methods: Blood and cerebrospinal fluid (CSF) were obtained from 142 MS (McDonald 2017) treatment-naive patients from the SET study (63% female; age: 29.7 ± 7.9 years) following the disease onset. NfL, albumin, immunoglobulin G (IgG), and immunoglobulin M (IgM) levels were measured in CSF and blood samples. Albumin quotient was computed as a marker of BBB integrity. Immune cell subset counts in CSF were measured using flow cytometry. MS risk factors, such as Human leukocyte antigen DRB1 locus gene ( HLA DRB1)*1501, anti-Epstein–Barr virus (EBV) antibodies, and 25-hydroxy vitamin D3, were also measured. Results: Higher serum NfL (sNfL) levels were associated with higher albumin quotient ( p < 0.001), CSF CD80+ ( p = 0.012), and CD80+ CD19+ ( p = 0.015) cell frequency. sNfL levels were also associated with contrast-enhancing and T2 lesions on brain magnetic resonance imaging (MRI; all p ⩽ 0.001). Albumin quotient was not associated with any of the MS risk factors assessed. sNfL levels were associated with anti-EBV viral capsid antigen (VCA) IgG levels ( p = 0.0026). Conclusion: sNfL levels during the first demyelinating event of MS are associated with greater impairment of BBB integrity, immune cell extravasation, and brain lesion activity on MRI.

scholarly journals Glucocorticoid effects on endothelial barrier function in the murine brain endothelial cell line cEND incubated with sera from patients with multiple sclerosis

2010 ◽  
Vol 16 (3) ◽  
pp. 293-302 ◽  
Author(s):  
Kinga G Blecharz ◽  
Aiden Haghikia ◽  
Mariusz Stasiolek ◽  
Niels Kruse ◽  
Detlev Drenckhahn ◽  
...  
Keyword(s):  
Gene Expression ◽  
Multiple Sclerosis ◽  
Endothelial Cell ◽  
Tight Junction ◽  
Blood Brain Barrier ◽  
Brain Barrier ◽  
Barrier Integrity ◽  
Blood Brain ◽  
Junction Protein ◽  
Blood Brain Barrier Integrity

Compromised blood—brain barrier integrity is a major hallmark of active multiple sclerosis (MS). Alterations in brain endothelial tight junction protein and gene expression occur early during neuroinflammation but there is little known about the underlying mechanisms. In this study, we analysed barrier compromising effects of sera from MS patients and barrier restoring effects of glucocorticoids on blood—brain barrier integrity in vitro. cEND murine brain microvascular endothelial cell monolayers were incubated with sera from patients in active phase of disease or in relapse. Data were compared with effects of the glucocorticoid dexamethasone alone or in combination with MS sera on barrier integrity. Tight junction protein levels and gene expression were evaluated concomitant with barrier integrity. We reveal downregulation of claudin-5 and occludin protein and mRNA and an accompanying upregulation in expression of matrix metalloproteinase MMP-9 after incubation with serum from active disease and remission and also a minor reconstitution of barrier functions related to dexamethasone treatment. Moreover, we for the first time describe downregulation of claudin-5 and occludin protein after incubation of cEND cells with sera from patients in remission phase of MS. Our findings reveal direct and differential effects of MS sera on blood-brain barrier integrity.

Nanotechnology: its application in treating Neurodegenerative diseases

2020 ◽  
Vol 19 ◽  
Author(s):  
Falaq Naz ◽  
Yasir Hasan Siddique
Keyword(s):  
Quality Of Life ◽  
Neurodegenerative Diseases ◽  
Blood Brain Barrier ◽  
Huntington Disease ◽  
Treatment Strategies ◽  
Present Review ◽  
Brain Barrier ◽  
Treatment Level ◽  
Blood Brain

: Neurodegenerative diseases including Alzheimer’s, Parkinson’s and Huntington disease are have serious concern due to its effect on the quality of life of affected persons. Neurodegenerative diseases have some limitations for both diagnostic as well as at treatment level. Introducing nanotechnology, for the treatment of these diseases may contribute significantly in solving the problem. There are several treatment strategies for the neurodegenerative diseases, but their limitations are the entry into the due to the presence of the blood-brain barrier (BBB). The present review highlights the application of nanotechnology during last 20 years for the treatment of neurodegenerative diseases.

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 Lipid polymeric nanoparticles modified with tight junction-modulating peptides promote afatinib delivery across a blood–brain barrier model

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Yu-Li Lo ◽  
Hua-Ching Lin ◽  
Shu-Ting Hong ◽  
Chih-Hsien Chang ◽  
Chen-Shen Wang ◽  
...  
Keyword(s):  
Brain Metastases ◽  
Tight Junction ◽  
Blood Brain Barrier ◽  
Polymeric Nanoparticles ◽  
Growth Factor Receptor ◽  
Brain Barrier ◽  
Polymeric Nanoparticle ◽  
Blood Brain ◽  
Blood Brain Barrier Model ◽  
Delivery Platform

Abstract Background Brain metastases from non-small cell lung cancer (NSCLC) remain one of the most challenging malignancies. Afatinib (Afa) is an orally administered irreversible ErbB family blocker approved for epidermal growth factor receptor (EGFR)-mutated NSCLC. However, the incidence of brain metastases in patients with NSCLC and EGFR mutation is high. One of the major obstacles in the treatment of brain metastases is to transport drugs across the blood–brain barrier (BBB). A lipid polymeric nanoparticle (LPN) modified with a tight junction-modulating peptide is a potential formulation to deliver therapeutics across the BBB. FD7 and CCD are short peptides that perturb the tight junctions (TJs) of the BBB. In this study, the use of LPN modified with FD7 or CCD as a delivery platform was explored to enhance Afa delivery across the BBB model of mouse brain-derived endothelial bEnd.3 cells. Results Our findings revealed that Afa/LPN-FD7 and Afa/LPN-CCD exhibited a homogeneous shape, a uniform nano-scaled particle size, and a sustained-release profile. FD7, CCD, Afa/LPN-FD7, and Afa/LPN-CCD did not cause a significant cytotoxic effect on bEnd.3 cells. Afa/LPN-FD7 and Afa/LPN-CCD across the bEnd.3 cells enhanced the cytotoxicity of Afa on human lung adenocarcinoma PC9 cells. FD7 and CCD-modulated TJ proteins, such as claudin 5 and ZO-1, reduced transendothelial electrical resistance, and increased the permeability of paracellular markers across the bEnd.3 cells. Afa/LPN-FD7 and Afa/LPN-CCD were also partially transported through clathrin- and caveolae-mediated transcytosis, revealing the effective activation of paracellular and transcellular pathways to facilitate Afa delivery across the BBB and cytotoxicity of Afa on PC9 cells. Conclusion TJ-modulating peptide-modified LPN could be a prospective platform for the delivery of chemotherapeutics across the BBB to the brain for the potential treatment of the BM of NSCLC.

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