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

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.

Author(s):  
Lorena Gárate-Vélez ◽  
Claudia Escudero-Lourdes ◽  
Daniela Salado-Leza ◽  
Armando González-Sánchez ◽  
Ildemar Alvarado-Morales ◽  
...  

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.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Marlyn D. Laksitorini ◽  
Vinith Yathindranath ◽  
Wei Xiong ◽  
Sabine Hombach-Klonisch ◽  
Donald W. Miller

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.


2008 ◽  
Vol 295 (4) ◽  
pp. R1099-R1108 ◽  
Author(s):  
Ferenc Domoki ◽  
Béla Kis ◽  
Tamás Gáspár ◽  
Ferenc Bari ◽  
David W. Busija

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.


2011 ◽  
Vol 32 (1) ◽  
pp. 177-189 ◽  
Author(s):  
Katayun Cohen-Kashi-Malina ◽  
Itzik Cooper ◽  
Vivian I Teichberg

At high concentrations, glutamate (Glu) exerts potent neurotoxic properties, leading to irreversible brain damages found in numerous neurological disorders. The accepted notion that Glu homeostasis in brain interstitial fluid is maintained primarily through the activity of Glu transporters present on glial cells does not take into account the possible contribution of endothelial cells constituting the blood-brain barrier (BBB) to this process. Here, we present evidence for the presence of the Glu transporters, excitatory amino-acid transporters (EAATs) 1 to 3, in porcine brain endothelial cells (PBECs) and show their participation in Glu uptake into PBECs. Moreover, transport of Glu across three in vitro models of the BBB is investigated for the first time, and evidence for Glu transport across the BBB in both directions is presented. Our results provide evidence that the BBB can function in the efflux mode to selectively remove Glu, via specific transporters, from the abluminal side (brain) into the luminal compartment (blood). Furthermore, we found that glial cells lining the BBB have an active role in the efflux process by taking up Glu and releasing it, through hemichannels, anion channels, and possibly the reversal of its EAATs, in close proximity to ECs, which in turn take up Glu and release it to the blood.


1997 ◽  
Vol 17 (4) ◽  
pp. 464-469 ◽  
Author(s):  
Marie-Pierre Dehouck ◽  
Paul Vigne ◽  
Gérard Torpier ◽  
Jean Philippe Breittmayer ◽  
Roméo Cecchelli ◽  
...  

Endothelial cells and pericytes are closely associated in brain capillaries. Together with astrocytic foot processes, they form the blood–brain barrier. Capillaries were isolated from bovine brain cortex. Pure populations of endothelial cells and pericytes were isolated and cultured in vitro. Polarized monolayers of endothelial cells preferentially secreted immunoreactive endothelin-1 (Et-1) at their abluminal (brain-facing) membrane. They did not express receptors for Et-1. Pericytes expressed BQ-123-sensitive ETA receptors for endothelins as evidenced by 125I-Et-1 binding experiments. These receptors were coupled to phospholipase C as demonstrated by intracellular calcium measurements using indo-1-loaded cells. Addition of Et-1 to pericytes induced marked changes in the cell morphology that were associated with a reorganization of F-actin and intermediate filaments. It is concluded that Et-1 is a paracrine mediator at the bovine blood–brain barrier and that capillary pericytes are target cells for endothelium-derived Et-1.


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