scholarly journals Astrocytes and Pericytes Differentially Modulate Blood—Brain Barrier Characteristics during Development and Hypoxic Insult

2010 ◽  
Vol 31 (2) ◽  
pp. 693-705 ◽  
Author(s):  
Abraham Al Ahmad ◽  
Carole Bürgi Taboada ◽  
Max Gassmann ◽  
Omolara O Ogunshola
Keyword(s):  
Blood Brain Barrier ◽  
Three Dimensional ◽  
In Vitro Models ◽  
Brain Barrier ◽  
Hypoxic Exposure ◽  
Cellular Interactions ◽  
Blood Brain ◽  
Open Questions

Understanding regulation of blood–brain barrier (BBB) is crucial to reduce/prevent its disruption during injury. As high brain complexity makes interpretation of in vivo data challenging, BBB studies are frequently performed using simplified in vitro models. However, many models fail to address the three-dimensional (3D) cellular interactions that occur in vivo, an important feature that may explain discrepancies in translation of in vitro data to the in vivo situation. We have designed and characterized an innovative 3D model that reproduces morphological and functional characteristics of the BBB in vivo and used it to investigate cellular interactions and contribution of astrocytes and pericytes to BBB development. Our model shows that both astrocytes and pericytes significantly suppress endothelial proliferation. In contrast, differential effects on tubulogenesis were observed with astrocytes reducing the number of tubes formed but increasing diameters and length, whereas pericytes had the opposite effect. Pericytes also induce proper localization of barrier proteins, lumen polarization, and functional activity of ATP-binding cassette (ABC) transporters similar to astrocytes, but the presence of both cells is required to maintain optimal barrier characteristics during hypoxic exposure. This model is simple, dynamic, and convenient to study many aspects of BBB function and represents an exciting new tool to address open questions of BBB regulation.

Refining In Vitro Neurotoxicity Testing — The Development of Blood–Brain Barrier Models

2003 ◽  
Vol 31 (3) ◽  
pp. 273-276 ◽  
Author(s):  
Hanna Tähti ◽  
Heidi Nevala ◽  
Tarja Toimela
Keyword(s):  
Blood Brain Barrier ◽  
Cell Lines ◽  
Three Dimensional ◽  
Brain Barrier ◽  
Culture Methods ◽  
Blood Brain ◽  
Capillary Endothelial Cells ◽  
In Vitro Bbb Model

The purpose of this paper is to review the current state of development of advanced in vitro blood–brain barrier (BBB) models. The BBB is a special capillary bed that separates the blood from the central nervous system (CNS) parenchyma. Astrocytes maintain the integrity of the BBB, and, without astrocytic contacts, isolated brain capillary endothelial cells in culture lose their barrier characteristics. Therefore, when developing in vitro BBB models, it is important to add astrocytic factors into the culture system. Recently, novel filter techniques and co-culture methods have made it possible to develop models which resemble the in vivo functions of the BBB in an effective way. With a BBB model, kinetic factors can be added into the in vitro batteries used for evaluating the neurotoxic potential of chemicals. The in vitro BBB model also represents a useful tool for the in vitro prediction of the BBB permeability of drugs, and offers the possibility to scan a large number of drugs for their potential to enter the CNS. Cultured monolayers of brain endothelial cell lines or selected epithelial cell lines, combined with astrocyte and neuron cultures, form a novel three-dimensional technique for the screening of neurotoxic compounds.

scholarly journals EXTH-66. NEO100 TRANSIENTLY OPENS UP THE BLOOD BRAIN BARRIER VIA TIGHT JUNCTION INHIBITION

2020 ◽  
Vol 22 (Supplement_2) ◽  
pp. ii101-ii102
Author(s):  
Thomas Chen ◽  
Weijun Wang ◽  
Nagore Marin Ramos ◽  
Axel Schonthal
Keyword(s):  
Tight Junction ◽  
Blood Brain Barrier ◽  
In Vitro Models ◽  
Brain Barrier ◽  
In Vivo Studies ◽  
Blue Dye ◽  
Blood Brain ◽  
Main Technique

Abstract The blood brain barrier (BBB) prevents effective entry of nearly all therapeutics to the central nervous system (CNS), preventing effective treatment of brain-related malignancies. Intracarotid mannitol injection has been the main technique to transiently open up the BBB, with its attendant variability and complications. A more direct and better tolerated method is needed to open up the BBB. We present our discovery that intraarterial (IA) injection of NEO100, a cGMP-quality form of perillyl alcohol (POH), transiently opens up the BBB in a safe and reversible manner. We used in-vitro models of MDCK1 and patient derived brain endothelial cell (BEC) + astrocyte barriers to determine that NEO100 increased FITC-antibody diffusion across the in-vitro BBB model and decreased trans-epithelial/endothelial electrical resistance (TEER). NEO100 effects on transcellular and paracellular pathways were studied using western blot, flow cytometry, HPLC, fluorescent probes, microarray analysis, and transmission electron microscopy. In-vivo studies were performed using ultrasound-guided intracardiac administration of NEO100 in mice with subsequent intravenous delivery of non-BBB permeable therapeutic agents. We determined that NEO100 transiently disrupts the transcellular pathway by permeabilizing BEC membranes, and the paracellular pathway via delocalization of tight junction proteins. In vivo IA NEO100 administration caused an effective dose- and time-dependent BBB permeabilization, which was reversible and well tolerated by the mice. This was evidenced by the spreading of Evans blue dye, and of therapeutics with different molecular weights, ie methotrexate, anti-PD-1 antibody, and CAR-T cells in the brain. Our results demonstrate that IA NEO100 is able to open the BBB in a controlled and reversible manner, allowing it to facilitate drug delivery to the CNS.

scholarly journals In vitro microfluidic modelling of the human blood-brain-barrier microvasculature and testing of nanocarrier transport

2020 ◽  
Author(s):  
Marco Campisi ◽  
Sharon W. L. Lee ◽  
Tatsuya Osaki ◽  
Luca Possenti ◽  
Clara Mattu ◽  
...  
Keyword(s):  
Blood Brain Barrier ◽  
Induced Pluripotent Stem Cell ◽  
In Vitro Models ◽  
Brain Barrier ◽  
Fibrin Gel ◽  
Blood Brain ◽  
Brain Pericytes ◽  
Induced Pluripotent

The blood-brain barrier (BBB) protects the brain from pathogens but also hinders drug delivery to the central nervous system. Most of the BBB models developed up to date failed to reproduce the human anatomical complexity of brain barriers, contributing to less predictive experimental platforms and poor patient outcomes. To overcome those limitations, the development of reliable in vitro models represents a crucial step towards more effective therapies. This contribution was focused on the development of an in vitro microfluidic model of the BBB able to replicate the human neurovascular organization. The microfluidic model included human induced pluripotent stem cell-derived endothelial cells, brain pericytes, and astrocytes as self-assembled microvascular networks in a 3-dimensional fibrin gel. As previously demonstrated, the BBB model exhibited perfusable and selective microvasculature, with permeability lower than conventional in vitro models and comparable with in vivo rat brain. Permeability of polystyrene nanoparticles (NPs) and synthesized polyurethane NP was measured across the BBB model as compared to conventional Transwell assays. This physiologically relevant BBB model offers an innovative and valuable platform to preclinically predict transport efficacy of drugs and carriers.

scholarly journals Biochemical‐ and Biophysical‐Induced Barriergenesis in the Blood–Brain Barrier: A Review of Barriergenic Factors for Use in In Vitro Models

2021 ◽  
Vol 1 (5) ◽  
pp. 2170051
Author(s):  
Christina L. Schofield ◽  
Aleixandre Rodrigo-Navarro ◽  
Matthew J. Dalby ◽  
Tom Van Agtmael ◽  
Manuel Salmeron-Sanchez
Keyword(s):  
Blood Brain Barrier ◽  
In Vitro Models ◽  
Brain Barrier ◽  
Blood Brain

Understanding the Physiology of the Blood-Brain Barrier: In Vitro Models

Physiology ◽  
1998 ◽  
Vol 13 (6) ◽  
pp. 287-293 ◽  
Author(s):  
Gerald A. Grant ◽  
N. Joan Abbott ◽  
Damir Janigro
Keyword(s):  
Central Nervous System ◽  
Tissue Culture ◽  
Nervous System ◽  
Blood Brain Barrier ◽  
In Vitro Models ◽  
Brain Barrier ◽  
Blood Brain ◽  
Brain Tissue Culture ◽  
The Brain

Endothelial cells exposed to inductive central nervous system factors differentiate into a blood-brain barrier phenotype. The blood-brain barrier frequently obstructs the passage of chemotherapeutics into the brain. Tissue culture systems have been developed to reproduce key properties of the intact blood-brain barrier and to allow for testing of mechanisms of transendothelial drug permeation.

Activation of PKC modulates blood-brain barrier endothelial cell permeability changes induced by hypoxia and posthypoxic reoxygenation

2005 ◽  
Vol 289 (5) ◽  
pp. H2012-H2019 ◽  
Author(s):  
Melissa A. Fleegal ◽  
Sharon Hom ◽  
Lindsay K. Borg ◽  
Thomas P. Davis
Keyword(s):  
Blood Brain Barrier ◽  
Paracellular Permeability ◽  
Cell Permeability ◽  
Brain Barrier ◽  
Cerebral Microvessels ◽  
Permeability Changes ◽  
Blood Brain ◽  
Brain Microvessel

The blood-brain barrier (BBB) is a metabolic and physiological barrier important for maintaining brain homeostasis. The aim of this study was to determine the role of PKC activation in BBB paracellular permeability changes induced by hypoxia and posthypoxic reoxygenation using in vitro and in vivo BBB models. In rat brain microvessel endothelial cells (RMECs) exposed to hypoxia (1% O2-99% N2; 24 h), a significant increase in total PKC activity was observed, and this was reduced by posthypoxic reoxygenation (95% room air-5% CO2) for 2 h. The expression of PKC-βII, PKC-γ, PKC-η, PKC-μ, and PKC-λ also increased following hypoxia (1% O2-99% N2; 24 h), and these protein levels remained elevated following posthypoxic reoxygenation (95% room air-5% CO2; 2 h). Increases in the expression of PKC-ε and PKC-ζ were also observed following posthypoxic reoxygenation (95% room air-5% CO2; 2 h). Moreover, inhibition of PKC with chelerythrine chloride (10 μM) attenuated the hypoxia-induced increases in [14C]sucrose permeability. Similar to what was observed in RMECs, total PKC activity was also stimulated in cerebral microvessels isolated from rats exposed to hypoxia (6% O2-94% N2; 1 h) and posthypoxic reoxygenation (room air; 10 min). In contrast, hypoxia (6% O2-94% N2; 1 h) and posthypoxic reoxygenation (room air; 10 min) significantly increased the expression levels of only PKC-γ and PKC-θ in the in vivo hypoxia model. These data demonstrate that hypoxia-induced BBB paracellular permeability changes occur via a PKC-dependent mechanism, possibly by differentially regulating the protein expression of the 11 PKC isozymes.

Sign in / Sign up

Export Citation Format

Share Document