scholarly journals Platelet Endothelial Cell Adhesion Molecule-1, a Putative Receptor for the Adhesion of Streptococcus pneumoniae to the Vascular Endothelium of the Blood-Brain Barrier

2014 ◽  
Vol 82 (9) ◽  
pp. 3555-3566 ◽  
Author(s):  
Federico Iovino ◽  
Grietje Molema ◽  
Jetta J. E. Bijlsma
Keyword(s):  
Endothelial Cells ◽  
Endothelial Cell ◽  
Streptococcus Pneumoniae ◽  
Blood Brain Barrier ◽  
Vascular Endothelium ◽  
Brain Barrier ◽  
Content Type ◽  
Blood Brain ◽  
Endothelial Cell Adhesion

ABSTRACTThe Gram-positive bacteriumStreptococcus pneumoniaeis the main causative agent of bacterial meningitis.S. pneumoniaeis thought to invade the central nervous system via the bloodstream by crossing the vascular endothelium of the blood-brain barrier. The exact mechanism by which pneumococci cross endothelial cell barriers before meningitis develops is unknown. Here, we investigated the role of PECAM-1/CD31, one of the major endothelial cell adhesion molecules, inS. pneumoniaeadhesion to vascular endothelium of the blood-brain barrier. Mice were intravenously infected with pneumococci and sacrificed at various time points to represent stages preceding meningitis. Immunofluorescent analysis of brain tissue of infected mice showed that pneumococci colocalized with PECAM-1. In human brain microvascular endothelial cells (HBMEC) incubated withS. pneumoniae, we observed a clear colocalization between PECAM-1 and pneumococci. Blocking of PECAM-1 reduced the adhesion ofS. pneumoniaeto endothelial cellsin vitro, implying that PECAM-1 is involved in pneumococcal adhesion to the cells. Furthermore, using endothelial cell protein lysates, we demonstrated thatS. pneumoniaephysically binds to PECAM-1. Moreover, bothin vitroandin vivoPECAM-1 colocalizes with theS. pneumoniaeadhesion receptor pIgR. Lastly, immunoprecipitation experiments revealed that PECAM-1 can physically interact with pIgR. In summary, we show for the first time that blood-borneS. pneumoniaecolocalizes with PECAM-1 expressed by brain microvascular endothelium and that, in addition, they colocalize with pIgR. We hypothesize that this interaction plays a role in pneumococcal binding to the blood-brain barrier vasculature prior to invasion into the brain.

scholarly journals The Proteasome-Ubiquitin System Is Required for Efficient Killing of Intracellular Streptococcus pneumoniae by Brain Endothelial Cells

mBio ◽  
2014 ◽  
Vol 5 (4) ◽  
Author(s):  
Federico Iovino ◽  
Henrik Gradstedt ◽  
Jetta J. Bijlsma
Keyword(s):  
Endothelial Cells ◽  
Streptococcus Pneumoniae ◽  
Blood Brain Barrier ◽  
Confocal Imaging ◽  
Brain Barrier ◽  
High Morbidity ◽  
Content Type ◽  
Blood Brain ◽  
Ubiquitin System

ABSTRACTStreptococcus pneumoniae(pneumococcus) is a Gram-positive bacterium that causes serious invasive diseases, such as pneumonia, bacteremia, and meningitis, with high morbidity and mortality throughout the world. Before causing invasive disease,S. pneumoniaeencounters cellular barriers, which are often composed of endothelial cells, like the alveolar-capillary barrier and the blood-brain barrier.S. pneumoniaeadheres to endothelial cells and may invade them, which requires an efficient host response to the intracellular bacteria. The precise intracellular fate ofS. pneumoniaeduring infection still remains a subject of debate. The proteasome-ubiquitin system is largely responsible for the degradation of misfolded, damaged, or no-longer-useful proteins. Recently, the role of the proteasome-ubiquitin system in the clearing of invading bacteria and viruses has been more closely studied. In this study, we show that inhibition of the proteasome-ubiquitin system leads to a marked increase inS. pneumoniaesurvival inside host cells. Immunofluorescence analysis showed that intracellular pneumococci colocalized with proteasome and ubiquitin in human endothelial cellsin vitro. Confocal imaging analysis demonstrated that in the brains of mice intravenously infected withS. pneumoniae, the bacteria were inside endothelial cells, where they colocalized with proteasome and ubiquitin signals. In conclusion, our data indicate that a fully functional proteasome-ubiquitin system in endothelial cells is crucial for efficient killing of intracellularS. pneumoniae.IMPORTANCEBacterial meningitis is a serious invasive disease with high morbidity and mortality. How bacteria traverse the blood-brain barrierin vivoand what mechanisms are employed by the host to prevent invasion are still unclear. Our data show that inhibition of the proteasome-ubiquitin systemin vitroleads to a significant increase inS. pneumoniaesurvival inside brain endothelial cells. Confocal imaging analysis of brain tissue from mice intravenously infected with pneumococci demonstrated that the bacteria are inside brain microvascular endothelial cells, where they associate with the proteasome and ubiquitin. This is, as far as we know, the first report that demonstrates thatStreptococcus pneumoniaeinvades endothelial cells of the blood-brain barrierin vivo. The host requires the proteasome-ubiquitin system for an efficient decimation of intracellularS. pneumoniae.

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.

scholarly journals In vitro models of the blood–brain barrier: An overview of commonly used brain endothelial cell culture models and guidelines for their use

2016 ◽  
Vol 36 (5) ◽  
pp. 862-890 ◽  
Author(s):  
Hans C Helms ◽  
N Joan Abbott ◽  
Malgorzata Burek ◽  
Romeo Cecchelli ◽  
Pierre-Olivier Couraud ◽  
...  
Keyword(s):  
Cell Culture ◽  
Endothelial Cell ◽  
Blood Brain Barrier ◽  
Brain Parenchyma ◽  
Brain Barrier ◽  
Blood Brain ◽  
Culture Models ◽  
Cell Culture Models ◽  
The Brain

The endothelial cells lining the brain capillaries separate the blood from the brain parenchyma. The endothelial monolayer of the brain capillaries serves both as a crucial interface for exchange of nutrients, gases, and metabolites between blood and brain, and as a barrier for neurotoxic components of plasma and xenobiotics. This “blood-brain barrier” function is a major hindrance for drug uptake into the brain parenchyma. Cell culture models, based on either primary cells or immortalized brain endothelial cell lines, have been developed, in order to facilitate in vitro studies of drug transport to the brain and studies of endothelial cell biology and pathophysiology. In this review, we aim to give an overview of established in vitro blood–brain barrier models with a focus on their validation regarding a set of well-established blood–brain barrier characteristics. As an ideal cell culture model of the blood–brain barrier is yet to be developed, we also aim to give an overview of the advantages and drawbacks of the different models described.

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 CoQ10 Deficient Endothelial Cell Culture Model for the Investigation of CoQ10 Blood–Brain Barrier Transport

2020 ◽  
Vol 9 (10) ◽  
pp. 3236
Author(s):  
Luke Wainwright ◽  
Iain P. Hargreaves ◽  
Ana R. Georgian ◽  
Charles Turner ◽  
R. Neil Dalton ◽  
...  
Keyword(s):  
Cell Culture ◽  
Endothelial Cell ◽  
Blood Brain Barrier ◽  
Advanced Glycation Endproducts ◽  
Brain Barrier ◽  
High Dose ◽  
Blood Brain ◽  
Coq10 Deficiency ◽  
The Brain

Primary coenzyme Q10 (CoQ10) deficiency is unique among mitochondrial respiratory chain disorders in that it is potentially treatable if high-dose CoQ10 supplements are given in the early stages of the disease. While supplements improve peripheral abnormalities, neurological symptoms are only partially or temporarily ameliorated. The reasons for this refractory response to CoQ10 supplementation are unclear, however, a contributory factor may be the poor transfer of CoQ10 across the blood–brain barrier (BBB). The aim of this study was to investigate mechanisms of CoQ10 transport across the BBB, using normal and pathophysiological (CoQ10 deficient) cell culture models. The study identifies lipoprotein-associated CoQ10 transcytosis in both directions across the in vitro BBB. Uptake via SR-B1 (Scavenger Receptor) and RAGE (Receptor for Advanced Glycation Endproducts), is matched by efflux via LDLR (Low Density Lipoprotein Receptor) transporters, resulting in no “net” transport across the BBB. In the CoQ10 deficient model, BBB tight junctions were disrupted and CoQ10 “net” transport to the brain side increased. The addition of anti-oxidants did not improve CoQ10 uptake to the brain side. This study is the first to generate in vitro BBB endothelial cell models of CoQ10 deficiency, and the first to identify lipoprotein-associated uptake and efflux mechanisms regulating CoQ10 distribution across the BBB. The results imply that the uptake of exogenous CoQ10 into the brain might be improved by the administration of LDLR inhibitors, or by interventions to stimulate luminal activity of SR-B1 transporters.

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