scholarly journals Hydralazine is a Suitable Mimetic Agent of Hypoxia to Study the Impact of Hypoxic Stress on In Vitro Blood-Brain Barrier Model

2017 ◽  
Vol 42 (4) ◽  
pp. 1592-1602 ◽  
Author(s):  
Morgane Chatard ◽  
Clémentine Puech ◽  
Nathalie Perek ◽  
Frédéric Roche
Keyword(s):  
Blood Brain Barrier ◽  
Brain Barrier ◽  
Hypoxic Stress ◽  
Cellular Mechanisms ◽  
Blood Brain ◽  
Junction Protein ◽  
Set Up ◽  
In Vitro Bbb Model ◽  
The Impact

Background/Aims: Understanding cellular mechanisms induced by hypoxia is fundamental to reduce blood-brain barrier (BBB) disruption. Nevertheless, the investigation of hypoxia on cellular pathways is complex with true hypoxia because HIF-1α has a short lifetime and rapidly reverts back to a normoxic state. To overcome this difficulty, mimetic agents of the hypoxia pathway have been developed, including the gold standard CoCl2. In this study, we proposed to compare CoCl2 and hydralazine in order to determine a suitable mimetic agent of hypoxia for the study on the BBB. Methods: We studied the cytotoxicity and the impact of these molecules on the integrity of an in vitro BBB model by comparing them to hypoxia controls. Results: We showed that the impact of hypoxic stress in our in vitro BBB model is rather similar between hydralazine and CoCl2. Chemical hypoxic stress led to an increase of BBB permeability either with CoCl2 or hydralazine. Tight junction protein expressions showed that this chemical hypoxic stress decreased ZO-1 but not occluding expressions, and cells had set up a defence mechanism by increasing expression and activity of their efflux transporters. Conclusion: Our results demonstrated that hydralazine is a better mimetic agent and more suitable than CoCl2 because it had the same effect but without the cytotoxic effect on in vitro BBB cells.

The Blood-Brain Barrier

2016 ◽  
Vol 23 (2) ◽  
pp. 124-136 ◽  
Author(s):  
Weihong Pan ◽  
Abba J. Kastin
Keyword(s):  
Blood Brain Barrier ◽  
Relevant Literature ◽  
The Body ◽  
Brain Barrier ◽  
Structural Basis ◽  
Sleep Disruption ◽  
Cellular Mechanisms ◽  
Blood Brain ◽  
Junction Protein ◽  
The Impact

Sleep and its disorders are known to affect the functions of essential organs and systems in the body. However, very little is known about how the blood-brain barrier (BBB) is regulated. A few years ago, we launched a project to determine the impact of sleep fragmentation and chronic sleep restriction on BBB functions, including permeability to fluorescent tracers, tight junction protein expression and distribution, glucose and other solute transporter activities, and mediation of cellular mechanisms. Recent publications and relevant literature allow us to summarize here the sleep-BBB interactions in five sections: (1) the structural basis enabling the BBB to serve as a huge regulatory interface; (2) BBB transport and permeation of substances participating in sleep-wake regulation; (3) the circadian rhythm of BBB function; (4) the effect of experimental sleep disruption maneuvers on BBB activities, including regional heterogeneity, possible threshold effect, and reversibility; and (5) implications of sleep disruption-induced BBB dysfunction in neurodegeneration and CNS autoimmune diseases. After reading the review, the general audience should be convinced that the BBB is an important mediating interface for sleep-wake regulation and a crucial relay station of mind-body crosstalk. The pharmaceutical industry should take into consideration that sleep disruption alters the pharmacokinetics of BBB permeation and CNS drug delivery, being attentive to the chrono timing and activation of co-transporters in subjects with sleep disorders.

scholarly journals Intermittent Hypoxia and Its Impact on Nrf2/HIF-1α Expression and ABC Transporters: An in Vitro Human Blood-Brain Barrier Model Study.

2020 ◽  
Vol 54 (6) ◽  
pp. 1231-1248
Keyword(s):  
Blood Brain Barrier ◽  
Abc Transporters ◽  
Intermittent Hypoxia ◽  
Brain Barrier ◽  
Upper Airways ◽  
Whole Cell ◽  
Blood Brain ◽  
Junction Protein ◽  
The Impact

BACKGROUND/AIMS: Obstructive sleep apnea (OSA) is characterized by repeated episodes of complete or partial obstruction of the upper airways, leading to chronic intermittent hypoxia (IH). OSA patients are considered at high cerebrovascular risk and may also present cognitive impairment. One hypothesis explored is that disturbances may be linked to blood-brain barrier (BBB) dysfunction. The BBB is a protective barrier separating the brain from blood flow. The BBB limits the paracellular pathway through tight and adherens junctions, and the transcellular passage by efflux pumps (ABC transporters). The aims of this study were to evaluate the impact of IH and sustained hypoxia (SH) on a validated in vitro BBB model and to investigate the factors expressed under both conditions. METHODS: Exposure of endothelial cells (HBEC-5i) in our in vitro model of BBB to hypoxia was performed using IH cycles: 1% O2-35 min/18% O2-25 min for 6 cycles or 6 h of SH at 1% O2. After exposure, we studied the cytotoxicity and the level of ROS in our cells. We measured the apparent BBB permeability using sodium fluorescein, FITC-dextran and TEER measurement. Whole cell ELISA were performed to evaluate the expression of tight junctions, ABC transporters, HIF-1α and Nrf2. The functionality of ABC transporters was evaluated with accumulation studies. Immunofluorescence assays were also conducted to illustrate the whole cell ELISAs. RESULTS: Our study showed that 6 h of IH or SH induced a BBB disruption marked by a significant decrease in junction protein expressions (claudin-5, VE-cadherin, ZO-1) and an increase in permeability. We also observed an upregulation in P-gp protein expression and functionality and a downregulation in BCRP. Hypoxia induced production of ROS, Nrf2 and HIF-1α. They were expressed in both sustained and intermittent conditions, but the expression and the activity of P-gp and BCRP were different. CONCLUSION: Understanding these mechanisms seems essential in order to propose new therapeutic strategies for patients with OSA

scholarly journals Dexamethasone Potentiates in Vitro Blood-Brain Barrier Recovery after Primary Blast Injury by Glucocorticoid Receptor-Mediated Upregulation of ZO-1 Tight Junction Protein

2015 ◽  
Vol 35 (7) ◽  
pp. 1191-1198 ◽  
Author(s):  
Christopher D Hue ◽  
Frances S Cho ◽  
Siqi Cao ◽  
Cameron R “Dale” Bass ◽  
David F Meaney ◽  
...  
Keyword(s):  
Glucocorticoid Receptor ◽  
Tight Junction ◽  
Blood Brain Barrier ◽  
Blast Injury ◽  
Brain Barrier ◽  
Primary Blast ◽  
Blood Brain ◽  
Junction Protein ◽  
In Vitro Bbb Model

Owing to the frequent incidence of blast-induced traumatic brain injury (bTBI) in recent military conflicts, there is an urgent need to develop effective therapies for bTBI-related pathologies. Blood-brain barrier (BBB) breakdown has been reported to occur after primary blast exposure, making restoration of BBB function and integrity a promising therapeutic target. We tested the hypothesis that treatment with dexamethasone (DEX) after primary blast injury potentiates recovery of an in vitro BBB model consisting of mouse brain endothelial cells (bEnd.3). DEX treatment resulted in complete recovery of transendothelial electrical resistance and hydraulic conductivity 1 day after injury, compared with 3 days for vehicle-treated injured cultures. Administration of RU486 (mifepristone) inhibited effects of DEX, confirming that barrier restoration was mediated by glucocorticoid receptor signaling. Potentiated recovery with DEX treatment was accompanied by stronger zonula occludens (ZO)-1 tight junction immunostaining and expression, suggesting that increased ZO-1 expression was a structural correlate to BBB recovery after blast. Interestingly, augmented ZO-1 protein expression was associated with specific upregulation of the α+ isoform but not the α− isoform. This is the first study to provide a mechanistic basis for potentiated functional recovery of an in vitro BBB model because of glucocorticoid treatment after primary blast injury.

scholarly journals Miniaturization and Automation of a Human In Vitro Blood–Brain Barrier Model for the High-Throughput Screening of Compounds in the Early Stage of Drug Discovery

Pharmaceutics ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 892
Author(s):  
Elisa L. J. Moya ◽  
Elodie Vandenhaute ◽  
Eleonora Rizzi ◽  
Marie-Christine Boucau ◽  
Johan Hachani ◽  
...  
Keyword(s):  
Drug Discovery ◽  
Blood Brain Barrier ◽  
Early Stage ◽  
Molecular Transport ◽  
Brain Barrier ◽  
Blood Brain ◽  
Cns Drugs ◽  
The Impact ◽  
The Brain

Central nervous system (CNS) diseases are one of the top causes of death worldwide. As there is a difficulty of drug penetration into the brain due to the blood–brain barrier (BBB), many CNS drugs treatments fail in clinical trials. Hence, there is a need to develop effective CNS drugs following strategies for delivery to the brain by better selecting them as early as possible during the drug discovery process. The use of in vitro BBB models has proved useful to evaluate the impact of drugs/compounds toxicity, BBB permeation rates and molecular transport mechanisms within the brain cells in academic research and early-stage drug discovery. However, these studies that require biological material (animal brain or human cells) are time-consuming and involve costly amounts of materials and plastic wastes due to the format of the models. Hence, to adapt to the high yields needed in early-stage drug discoveries for compound screenings, a patented well-established human in vitro BBB model was miniaturized and automated into a 96-well format. This replicate met all the BBB model reliability criteria to get predictive results, allowing a significant reduction in biological materials, waste and a higher screening capacity for being extensively used during early-stage drug discovery studies.

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 VLA-4 mediated adhesion of melanoma cells on the blood–brain barrier is the critical cue for melanoma cell intercalation and barrier disruption

2018 ◽  
Vol 39 (10) ◽  
pp. 1995-2010 ◽  
Author(s):  
Ana B García-Martín ◽  
Pascale Zwicky ◽  
Thomas Gruber ◽  
Christoph Matti ◽  
Federica Moalli ◽  
...  
Keyword(s):  
Brain Metastasis ◽  
Blood Brain Barrier ◽  
Barrier Properties ◽  
Melanoma Cells ◽  
Brain Barrier ◽  
Adhesive Interaction ◽  
Inflammatory Conditions ◽  
Blood Brain ◽  
In Vitro Bbb Model

Melanoma is the most aggressive skin cancer in humans. One severe complication is the formation of brain metastasis, which requires extravasation of melanoma cells across the tight blood–brain barrier (BBB). Previously, VLA-4 has been assigned a role for the adhesive interaction of melanoma cells with non-BBB endothelial cells. However, the role of melanoma VLA-4 for breaching the BBB remained unknown. In this study, we used a mouse in vitro BBB model and imaged the shear resistant arrest of melanoma cells on the BBB. Similar to effector T cells, inflammatory conditions of the BBB increased the arrest of melanoma cells followed by a unique post-arrest behavior lacking immediate crawling. However, over time, melanoma cells intercalated into the BBB and compromised its barrier properties. Most importantly, antibody ablation of VLA-4 abrogated melanoma shear resistant arrest on and intercalation into the BBB and protected the BBB from barrier breakdown. A tissue microarray established from human brain metastasis revealed that indeed a majority of 92% of all human melanoma brain metastases stained VLA-4 positive. We propose VLA-4 as a target for the inhibition of brain metastasis formation in the context of personalized medicine identifying metastasizing VLA-4 positive melanoma.

Interferon-β stabilizes barrier characteristics of the blood–brain barrier in four different species in vitro

2008 ◽  
Vol 14 (6) ◽  
pp. 843-852 ◽  
Author(s):  
J Kraus ◽  
K Voigt ◽  
AM Schuller ◽  
M Scholz ◽  
KS Kim ◽  
...  
Keyword(s):  
Blood Brain Barrier ◽  
Treatment Efficacy ◽  
Paracellular Permeability ◽  
Brain Barrier ◽  
Early Event ◽  
Interferon Β ◽  
Recombinant Interferon ◽  
Blood Brain ◽  
In Vitro Bbb Model

Background Blood–brain barrier (BBB) breakdown is an early event in the pathogenesis of multiple sclerosis (MS). In a previous study we have found a direct stabilization of barrier characteristics after treatment of bovine brain capillary endothelial cells (BCECs) with human recombinant interferon-β-1a (IFN-β-1a) in an in vitro BBB model. In the present study we examined the effect of human recombinant IFN-β-1a on the barrier properties of BCECs derived from four different species including humans to predict treatment efficacy of IFN-β-1a in MS patients. Methods We used primary bovine and porcine BCECs, as well as human and murine BCEC cell lines. We investigated the influence of human recombinant IFN-β-1a on the paracellular permeability for 3H-inulin and 14C-sucrose across monolayers of bovine, human, and murine BCECs. In addition, the transendothelial electrical resistance (TEER) was determined in in vitro systems applying porcine and murine BCECS. Results We found a stabilizing effect on the barrier characteristics of BCECs after pretreatment with IFN-β-1a in all applied in vitro models: addition of IFN-β-1a resulted in a significant decrease of the paracellular permeability across monolayers of human, bovine, and murine BCECs. Furthermore, the TEER was significantly increased after pretreatment of porcine and murine BCECs with IFN-β-1a. Conclusion Our data suggest that BBB stabilization by IFN-β-1a may contribute to its beneficial effects in the treatment of MS. A human in vitro BBB model might be useful as bioassay for testing the treatment efficacy of drugs in MS.

scholarly journals ALCAM (CD166) is involved in extravasation of monocytes rather than T cells across the blood–brain barrier

2016 ◽  
Vol 37 (8) ◽  
pp. 2894-2909 ◽  
Author(s):  
Ruth Lyck ◽  
Marc-André Lécuyer ◽  
Michael Abadier ◽  
Christof B Wyss ◽  
Christoph Matti ◽  
...  
Keyword(s):  
Blood Brain Barrier ◽  
Brain Barrier ◽  
Th1 Cells ◽  
Human Brain Tissue ◽  
Autoimmune Encephalomyelitis ◽  
Tissue Samples ◽  
Blood Brain ◽  
Static Conditions ◽  
In Vitro Bbb Model

Activated leukocyte cell adhesion molecule (ALCAM) has been proposed to mediate leukocyte migration across the blood–brain barrier (BBB) in multiple sclerosis or experimental autoimmune encephalomyelitis (EAE). Here, we confirmed vascular ALCAM expression in human brain tissue samples in situ and on two different human in vitro BBB models. Antibody-mediated inhibition of ALCAM reduced diapedesis of human CD4+ Th1 but not of Th17 cells across the human BBB in vitro. In accordance to human Th1 cells, mouse Th1 cells showed reduced diapedesis across an ALCAM−/− in vitro BBB model under static but no longer under flow conditions. In contrast to the limited role of ALCAM in T cell extravasation across the BBB, we found a contribution of ALCAM to rolling, adhesion, and diapedesis of human CD14+ monocytes across the human BBB under flow and static conditions. Taken together, our study highlights the potential differences in the CNS expression of ALCAM in mouse and human and supports a prominent role for ALCAM in the multi-step extravasation of monocytes across the BBB.

scholarly journals Biotransformation modulates the penetration of metallic nanomaterials across an artificial blood–brain barrier model

2021 ◽  
Vol 118 (28) ◽  
pp. e2105245118
Author(s):  
Zhiling Guo ◽  
Peng Zhang ◽  
Swaroop Chakraborty ◽  
Andrew J Chetwynd ◽  
Fazel Abdolahpur Monikh ◽  
...  
Keyword(s):  
Blood Brain Barrier ◽  
Brain Barrier ◽  
Complex Nature ◽  
Blood Brain ◽  
Blood Brain Barrier Model ◽  
Subsequent Behavior ◽  
Neurological Effects ◽  
In Vitro Bbb Model ◽  
The Brain

Understanding the potential of nanomaterials (NMs) to cross the blood–brain barrier (BBB), as a function of their physicochemical properties and subsequent behavior, fate, and adverse effect beyond that point, is vital for evaluating the neurological effects arising from their unintentional entry into the brain, which is yet to be fully explored. This is not only due to the complex nature of the brain but also the existing analytical limitations for characterization and quantification of NMs in the complex brain environment. By using a fit-for-purpose analytical workflow and an in vitro BBB model, we show that the physiochemical properties of metallic NMs influence their biotransformation in biological matrices, which in turn modulates the transport form, efficiency, amounts, and pathways of NMs through the BBB and, consequently, their neurotoxicity. The data presented here will support in silico modeling and prediction of the neurotoxicity of NMs and facilitate the tailored design of safe NMs.

scholarly journals Cellular Prion Protein Participates in Amyloid-β Transcytosis across the Blood—Brain Barrier

2012 ◽  
Vol 32 (4) ◽  
pp. 628-632 ◽  
Author(s):  
Thorsten Pflanzner ◽  
Benjamin Petsch ◽  
Bettina André-Dohmen ◽  
Andreas Müller-Schiffmann ◽  
Sabrina Tschickardt ◽  
...  
Keyword(s):  
Prion Protein ◽  
Blood Brain Barrier ◽  
Amyloid Β ◽  
Cellular Prion Protein ◽  
Brain Barrier ◽  
Putative Receptor ◽  
Blood Brain ◽  
In Vitro Bbb Model

The blood—brain barrier (BBB) facilitates amyloid-β (Aβ) exchange between the blood and the brain. Here, we found that the cellular prion protein (PrPc), a putative receptor implicated in mediating Aβ neurotoxicity in Alzheimer's disease (AD), participates in Aβ transcytosis across the BBB. Using an in vitro BBB model, [125I]-Aβ1–40 transcytosis was reduced by genetic knockout of PrPc or after addition of a competing PrPc-specific antibody. Furthermore, we provide evidence that PrPc is expressed in endothelial cells and, that monomeric Aβ1–40 binds to PrPc. These observations provide new mechanistic insights into the role of PrPc in AD.

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