scholarly journals Rho-mediated regulation of tight junctions during monocyte migration across the blood-brain barrier in HIV-1 encephalitis (HIVE)

Blood ◽  
2006 ◽  
Vol 107 (12) ◽  
pp. 4770-4780 ◽  
Author(s):  
Yuri Persidsky ◽  
David Heilman ◽  
James Haorah ◽  
Marina Zelivyanskaya ◽  
Raisa Persidsky ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Tight Junctions ◽  
Blood Brain Barrier ◽  
Rho Kinase ◽  
Dominant Negative ◽  
Brain Barrier ◽  
Monocyte Migration ◽  
Blood Brain ◽  
Hiv 1

AbstractThe blood-brain barrier (BBB) is compromised during progressive HIV-1 infection, but how this occurs is incompletely understood. We studied the integrity of tight junctions (TJs) of brain microvascular endothelial cells (BMVECs) in an in vitro BBB system and in human brain tissues with HIV-1 encephalitis (HIVE). A downregulation of TJ proteins, claudin-5 and occludin, paralleled monocyte migration into the brain during HIVE. Because small G proteins (such as Rho) can play a role in BMVEC TJ assembly, an artificial BBB system explored the relationship among TJs, Rho/Rho kinase (RhoK) activation, and transendothelial monocyte migration. Coculture of monocytes with endothelial cells led to Rho activation and phosphorylation of TJ proteins. Rho and RhoK inhibitors blocked migration of infected and uninfected monocytes. The RhoK inhibitor protected BBB integrity and reversed occludin/claudin-5 phosphorylation associated with monocyte migration. BMVEC transfection with a constitutively active mutant of RhoK led to dislocation of occludin from the membrane and loss of BMVEC cell contacts. When dominant-negative RhoK-transfected BMVECs were used in BBB constructs, monocyte migration was reduced by 84%. Thus, loss of TJ integrity was associated with Rho activation caused by monocyte brain migration, suggesting that Rho/RhoK activation in BMVECs could be an underlying cause of BBB impairment during HIVE.

Adsorptive endocytosis mediates the passage of HIV-1 across the blood-brain barrier: evidence for a post-internalization coreceptor

1998 ◽  
Vol 111 (4) ◽  
pp. 533-540 ◽  
Author(s):  
W.A. Banks ◽  
V. Akerstrom ◽  
A.J. Kastin
Keyword(s):  
Endothelial Cells ◽  
Blood Brain Barrier ◽  
Brain Barrier ◽  
Aids Dementia Complex ◽  
Blood Brain ◽  
Wheatgerm Agglutinin ◽  
Adsorptive Endocytosis ◽  
Hiv 1

HIV-1 induces the AIDS dementia complex and infects brain endothelial and glial cells. Because the endothelial cells comprising the blood-brain barrier (BBB) do not possess CD4 receptors or galactosylceramide binding sites, it is unclear how HIV-1 negotiates the BBB. Previous work has suggested that gp120, the glycoprotein viral coat of HIV-1, is capable of inducing adsorptive endocytosis. Glycoprotein lectins like wheatgerm agglutinin induce adsorptive endocytosis and greatly potentiate the uptake by and passage across mouse endothelial cells in vivo and in vitro. We show here that the wheatgerm agglutinin-induced binding of gp120 is dose-dependent and involves components of the cytoskeleton. The uptake is partially dependent on temperature and energy and is modestly enhanced by potassium depletion. Glycosylation of gp120 is critical for its uptake by adsorptive endocytosis since the non-glycosylated form of gp120 is unaffected by wheatgerm agglutinin. Evidence is presented for the existence of a coreceptor sensitive to protamine sulfate that is primarily involved in membrane fusion after 125I-gp120 has bound to the cell membrane and is probably activated after internalization. This coreceptor probably contains a negatively charged heparin sulfate group and could be a member of the chemokine receptor family.

scholarly journals Blood-Brain Barrier Abnormalities Caused by HIV-1 gp120: Mechanistic and Therapeutic Implications

2012 ◽  
Vol 2012 ◽  
pp. 1-15 ◽  
Author(s):  
Jean-Pierre Louboutin ◽  
David S. Strayer
Keyword(s):  
Endothelial Cells ◽  
Tight Junctions ◽  
Blood Brain Barrier ◽  
Brain Barrier ◽  
Partial Protection ◽  
Therapeutic Implications ◽  
Blood Brain ◽  
Hiv Envelope ◽  
Hiv 1 ◽  
Envelope Gp120

The blood-brain barrier (BBB) is compromised in many systemic and CNS diseases, including HIV-1 infection of the brain. We studied BBB disruption caused by HIV-1 envelope glycoprotein 120 (gp120) as a model. Exposure to gp120, whether acute [by direct intra-caudate-putamen (CP) injection] or chronic [using SV(gp120), an experimental model of ongoing production of gp120] disrupted the BBB, and led to leakage of vascular contents. Gp120 was directly toxic to brain endothelial cells. Abnormalities of the BBB reflect the activity of matrix metalloproteinases (MMPs). These target laminin and attack the tight junctions between endothelial cells and BBB basal laminae. MMP-2 and MMP-9 were upregulated following gp120-injection. Gp120 reduced laminin and tight junction proteins. Reactive oxygen species (ROS) activate MMPs. Injecting gp120 induced lipid peroxidation. Gene transfer of antioxidant enzymes protected against gp120-induced BBB abnormalities. NMDA upregulates the proform of MMP-9. Using the NMDA receptor (NMDAR-1) inhibitor, memantine, we observed partial protection from gp120-induced BBB injury. Thus, (1) HIV-envelope gp120 disrupts the BBB; (2) this occurs via lesions in brain microvessels, MMP activation and degradation of vascular basement membrane and vascular tight junctions; (3) NMDAR-1 activation plays a role in this BBB injury; and (4) antioxidant gene delivery as well as NMDAR-1 antagonists may protect the BBB.

scholarly journals Intravenous injection of cyclophilin A realizes the transient and reversible opening of barrier of neural vasculature through basigin in endothelial cells

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Narumi Nakada-Honda ◽  
Dan Cui ◽  
Satoshi Matsuda ◽  
Eiji Ikeda
Keyword(s):  
Endothelial Cells ◽  
Single Dose ◽  
Blood Brain Barrier ◽  
Intravenous Injection ◽  
Cyclophilin A ◽  
Brain Barrier ◽  
Blood Brain ◽  
Neural Tissues ◽  
Neural Diseases

AbstractNeural vasculature forms the blood–brain barrier against the delivery of systemically administered therapeutic drugs into parenchyma of neural tissues. Therefore, procedures to open the blood–brain barrier with minimal damage to tissues would lead to the great progress in therapeutic strategy for intractable neural diseases. In this study, through analyses with mouse in vitro brain microvascular endothelial cells and in vivo neural vasculature, we demonstrate that the administration of cyclophilin A (CypA), a ligand of basigin which is expressed in barrier-forming endothelial cells, realizes the artificial opening of blood–brain barrier. Monolayers of endothelial cells lost their barrier properties through the disappearance of claudin-5, an integral tight junction molecule, from cell membranes in a transient and reversible manner. Furthermore, the intravenous injection of a single dose of CypA into mice resulted in the opening of blood–brain barrier for a certain period which enabled the enhanced delivery of systemically administered doxorubicin into the parenchyma of neural tissues. These findings that the pre-injection of a single dose of CypA realizes an artificial, transient as well as reversible opening of blood–brain barrier are considered to be a great step toward the establishment of therapeutic protocols to overcome the intractability of neural diseases.

Modulation of tight junction structure in blood-brain barrier endothelial cells. Effects of tissue culture, second messengers and cocultured astrocytes

1994 ◽  
Vol 107 (5) ◽  
pp. 1347-1357 ◽  
Author(s):  
H. Wolburg ◽  
J. Neuhaus ◽  
U. Kniesel ◽  
B. Krauss ◽  
E.M. Schmid ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Tight Junction ◽  
Tight Junctions ◽  
Blood Brain Barrier ◽  
Barrier Function ◽  
Primary Cultures ◽  
Brain Barrier ◽  
Brain Endothelial Cells ◽  
Blood Brain ◽  
Camp Levels

Tight junctions between endothelial cells of brain capillaries are the most important structural elements of the blood-brain barrier. Cultured brain endothelial cells are known to loose tight junction-dependent blood-brain barrier characteristics such as macromolecular impermeability and high electrical resistance. We have directly analyzed the structure and function of tight junctions in primary cultures of bovine brain endothelial cells using quantitative freeze-fracture electron microscopy, and ion and inulin permeability. The complexity of tight junctions, defined as the number of branch points per unit length of tight junctional strands, decreased 5 hours after culture but thereafter remained almost constant. In contrast, the association of tight junction particles with the cytoplasmic leaflet of the endothelial membrane bilayer (P-face) decreased continuously with a major drop between 16 hours and 24 hours. The complexity of tight junctions could be increased by elevation of intracellular cAMP levels while phorbol esters had the opposite effect. On the other hand, the P-face association of tight junction particles was enhanced by elevation of cAMP levels and by coculture of endothelial cells with astrocytes or exposure to astrocyte-conditioned medium. The latter effect on P-face association was induced by astrocytes but not fibroblasts. Elevation of cAMP levels together with astrocyte-conditioned medium synergistically increased transendothelial electrical resistance and decreased inulin permeability of primary cultures, thus confirming the effects on tight junction structure and barrier function. P-face association of tight junction particles in brain endothelial cells may therefore be a critical feature of blood-brain barrier function that can be specifically modulated by astrocytes and cAMP levels. Our results suggest an important functional role for the cytoplasmic anchorage of tight junction particles for brain endothelial barrier function in particular and probably paracellular permeability in general.

Anthropogenic Iron Oxide Nanoparticles Induce Damage to Brain Microvascular Endothelial Cells Forming the Blood-Brain Barrier

2021 ◽  
Author(s):  
Lorena Gárate-Vélez ◽  
Claudia Escudero-Lourdes ◽  
Daniela Salado-Leza ◽  
Armando González-Sánchez ◽  
Ildemar Alvarado-Morales ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Blood Brain Barrier ◽  
Brain Barrier ◽  
Microvascular Endothelial Cells ◽  
Brain Microvascular Endothelial Cells ◽  
Blood Brain ◽  
Fe3o4 Nps ◽  
Microvascular Endothelial ◽  
The Brain

Background: Iron nanoparticles, mainly in magnetite phase (Fe3O4 NPs), are released to the environment in areas with high traffic density and braking frequency. Fe3O4 NPs were found in postmortem human brains and are assumed to get directly into the brain through the olfactory nerve. However, these pollution-derived NPs may also translocate from the lungs to the bloodstream and then, through the blood-brain barrier (BBB), into the brain inducing oxidative and inflammatory responses that contribute to neurodegeneration. Objective: To describe the interaction and toxicity of pollution-derived Fe3O4 NPs on primary rat brain microvascular endothelial cells (rBMECs), main constituents of in vitro BBB models. Methods: Synthetic bare Fe3O4 NPs that mimic the environmental ones (miFe3O4) were synthesized by co-precipitation and characterized using complementary techniques. The rBMECs were cultured in Transwell® plates. The NPs-cell interaction was evaluated through transmission electron microscopy and standard colorimetric in vitro assays. Results: The miFe3O4 NPs, with a mean diameter of 8.45 ± 0.14 nm, presented both magnetite and maghemite phases, and showed super-paramagnetic properties. Results suggest that miFe3O4 NPs are internalized by rBMECs through endocytosis and that they are able to cross the cells monolayer. The lowest miFe3O4 NPs concentration tested induced mid cytotoxicity in terms of 1) membrane integrity (LDH release) and 2) metabolic activity (MTS transformation). Conclusion: Pollution-derived Fe3O4 NPs may interact and cross the microvascular endothelial cells forming the BBB and cause biological damage.

scholarly journals GRL-04810 and GRL-05010, Difluoride-Containing Nonpeptidic HIV-1 Protease Inhibitors (PIs) That Inhibit the Replication of Multi-PI-Resistant HIV-1In Vitroand Possess Favorable Lipophilicity That May Allow Blood-Brain Barrier Penetration

2013 ◽  
Vol 57 (12) ◽  
pp. 6110-6121 ◽  
Author(s):  
Pedro Miguel Salcedo Gómez ◽  
Masayuki Amano ◽  
Sofiya Yashchuk ◽  
Akira Mizuno ◽  
Debananda Das ◽  
...  
Keyword(s):  
Protease Inhibitors ◽  
Blood Brain Barrier ◽  
Wide Spectrum ◽  
Laboratory Strain ◽  
Cyclic Ether ◽  
Brain Barrier ◽  
Blood Brain ◽  
Immunodeficiency Virus ◽  
Hiv 1

ABSTRACTWe designed, synthesized, and identified two novel nonpeptidic human immunodeficiency virus type 1 (HIV-1) protease inhibitors (PIs), GRL-04810 and GRL-05010, containing the structure-based designed privileged cyclic ether-derived nonpeptide P2 ligand,bis-tetrahydrofuranylurethane (bis-THF), and a difluoride moiety, both of which are active against the laboratory strain HIV-1LAI(50% effective concentrations [EC50s], 0.0008 and 0.003 μM, respectively) with minimal cytotoxicity (50% cytotoxic concentrations [CC50s], 17.5 and 37.0 μM, respectively, in CD4+MT-2 cells). The two compounds were active against multi-PI-resistant clinical HIV-1 variants isolated from patients who had no response to various antiviral regimens. GRL-04810 and GRL-05010 also blocked the infectivity and replication of each of the HIV-1NL4-3variants selected by up to 5 μM lopinavir (EC50s, 0.03 and 0.03 μM, respectively) and atazanavir (EC50s, 0.02 and 0.04 μM, respectively). Moreover, they were active against darunavir (DRV)-resistant variants (EC50in 0.03 to 0.034 μM range for GRL-04810 and 0.026 to 0.043 μM for GRL-05010), while DRV had EC50s between 0.02 and 0.174 μM. GRL-04810 had a favorable lipophilicity profile as determined with the partition (logP) and distribution (logD) coefficients of −0.14 and −0.29, respectively. Thein vitroblood-brain barrier (BBB) permeability assay revealed that GRL-04810 and GRL-05010 may have a greater advantage in terms of crossing the BBB than the currently available PIs, with apparent penetration indexes of 47.8 × 10−6and 61.8 × 10−6cm/s, respectively. The present data demonstrate that GRL-04810 and GRL-05010 exert efficient activity against a wide spectrum of HIV-1 variantsin vitroand suggest that two fluorine atoms added to theirbis-THF moieties may well enhance their penetration across the BBB.

scholarly journals Modulation of Wnt/β-catenin signaling promotes blood-brain barrier phenotype in cultured brain endothelial cells

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Marlyn D. Laksitorini ◽  
Vinith Yathindranath ◽  
Wei Xiong ◽  
Sabine Hombach-Klonisch ◽  
Donald W. Miller
Keyword(s):  
Endothelial Cells ◽  
Wnt Signaling ◽  
Blood Brain Barrier ◽  
Brain Barrier ◽  
Brain Endothelial Cells ◽  
Cancer Resistance ◽  
Blood Brain ◽  
Culture Model ◽  
External Activation

AbstractWnt/β-catenin signaling is important for blood-brain barrier (BBB) development and is implicated in BBB breakdown under various pathophysiological conditions. In the present study, a comprehensive characterization of the relevant genes, transport and permeability processes influenced by both the autocrine and external activation of Wnt signaling in human brain endothelial cells was examined using hCMEC/D3 culture model. The hCMEC/D3 expressed a full complement of Wnt ligands and receptors. Preventing Wnt ligand release from hCMEC/D3 produced minimal changes in brain endothelial function, while inhibition of intrinsic/autocrine Wnt/β-catenin activity through blocking β-catenin binding to Wnt transcription factor caused more modest changes. In contrast, activation of Wnt signaling using exogenous Wnt ligand (Wnt3a) or LiCl (GSK3 inhibitor) improved the BBB phenotypes of the hCMEC/D3 culture model, resulting in reduced paracellular permeability, and increased P-glycoprotein (P-gp) and breast cancer resistance associated protein (BCRP) efflux transporter activity. Further, Wnt3a reduced plasmalemma vesicle associated protein (PLVAP) and vesicular transport activity in hCMEC/D3. Our data suggest that this in vitro model of the BBB has a more robust response to exogenous activation of Wnt/β-catenin signaling compared to autocrine activation, suggesting that BBB regulation may be more dependent on external activation of Wnt signaling within the brain microvasculature.

scholarly journals Cerebromicrovascular endothelial cells are resistant to l-glutamate

2008 ◽  
Vol 295 (4) ◽  
pp. R1099-R1108 ◽  
Author(s):  
Ferenc Domoki ◽  
Béla Kis ◽  
Tamás Gáspár ◽  
Ferenc Bari ◽  
David W. Busija
Keyword(s):  
Endothelial Cells ◽  
Blood Brain Barrier ◽  
Primary Cultures ◽  
Glucose Deprivation ◽  
Brain Barrier ◽  
Cranial Window ◽  
Blood Brain ◽  
Microvascular Cells

Cerebral microvascular endothelial cells (CMVECs) have recently been implicated as targets of excitotoxic injury by l-glutamate (l-glut) or N-methyl-d-aspartate (NMDA) in vitro. However, high levels of l-glut do not compromise the function of the blood-brain barrier in vivo. We sought to determine whether primary cultures of rat and piglet CMVECs or cerebral microvascular pericytes (CMVPCs) are indeed sensitive to l-glut or NMDA. Viability was unaffected by 8-h exposure to 1–10 mM l-glut or NMDA in CMVECs or CMVPCs isolated from both species. Furthermore, neither 1 mM l-glut nor NMDA augmented cell death induced by 12-h oxygen-glucose deprivation in rat CMVECs or by 8-h medium withdrawal in CMVPCs. Additionally, transendothelial electrical resistance of rat CMVEC-astrocyte cocultures or piglet CMVEC cultures were not compromised by up to 24-h exposure to 1 mM l-glut or NMDA. The Ca2+ ionophore calcimycin (5 μM), but not l-glut (1 mM), increased intracellular Ca2+ levels in rat CMVECs and CMVPCs assessed with fluo-4 AM fluorescence and confocal microscopy. CMVEC-dependent pial arteriolar vasodilation to hypercapnia and bradykinin was unaffected by intracarotid infusion of l-glut in anesthetized piglets by closed cranial window/intravital microscopy. We conclude that cerebral microvascular cells are insensitive and resistant to glutamatergic stimuli in accordance with their in vivo role as regulators of potentially neurotoxic amino acids across the blood-brain barrier.

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