Baicalin reduces the permeability of the blood–brain barrier during hypoxia in vitro by increasing the expression of tight junction proteins in brain microvascular endothelial cells

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.

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MicroRNA-30a regulates acute cerebral ischemia-induced blood–brain barrier damage through ZnT4/zinc pathway

Journal of Cerebral Blood Flow & Metabolism ◽

10.1177/0271678x20926787 ◽

2020 ◽

pp. 0271678X2092678 ◽

Cited By ~ 1

Author(s):

Peng Wang ◽

Rong Pan ◽

John Weaver ◽

Mengjie Jia ◽

Xue Yang ◽

...

Keyword(s):

Ischemic Stroke ◽

Cerebral Ischemia ◽

Tight Junction ◽

Blood Brain Barrier ◽

Brain Barrier ◽

Tight Junction Proteins ◽

Blood Brain ◽

Acute Cerebral Ischemia ◽

Junction Proteins

The mechanism of early blood–brain barrier (BBB) disruption after stroke has been intensively studied but still not fully understood. Here, we report that microRNA-30a (miR-30a) could mediate BBB damage using both cellular and animal models of ischemic stroke. In the experiments in vitro, inhibition of miR-30a decreased BBB permeability, prevented the degradation of tight junction proteins, and reduced intracellular free zinc in endothelial cells. We found that the zinc transporter ZnT4 was a direct target of negative regulation by miR-30a, and ZnT4/zinc signaling pathway contributed significantly to miR-30a-mediated BBB damage. Consistent with these in vitro findings, treatment with miR-30a inhibitor reduced zinc accumulation, increased the expression of ZnT4, and prevented the loss of tight junction proteins in microvessels of ischemic animals. Furthermore, inhibition of miR-30a, even at 90 min post onset of middle cerebral artery occlusion, prevented BBB damage, reduced infarct volume, and ameliorated neurological deficits. Together, our findings provide novel insights into the mechanisms of cerebral ischemia-induced BBB disruption and indicate miR-30a as a regulator of BBB function that can be an effective therapeutic target for ischemic stroke.

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Correlation of tight junction morphology with the expression of tight junction proteins in blood-brain barrier endothelial cells

European Journal of Cell Biology ◽

10.1078/0171-9335-00101 ◽

2000 ◽

Vol 79 (10) ◽

pp. 707-717 ◽

Cited By ~ 132

Author(s):

Stefan Liebner ◽

Uwe Kniesel ◽

Hubert Kalbacher ◽

Hartwig Wolburg

Keyword(s):

Endothelial Cells ◽

Tight Junction ◽

Blood Brain Barrier ◽

Brain Barrier ◽

Tight Junction Proteins ◽

Blood Brain ◽

Junction Proteins

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Isolation and Culture of Brain Microvascular Endothelial Cells for In Vitro Blood-Brain Barrier Studies

Neurotrophic Factors - Methods in Molecular Biology ◽

10.1007/978-1-4939-7571-6_23 ◽

2017 ◽

pp. 315-331 ◽

Cited By ~ 13

Author(s):

Hector Rosas-Hernandez ◽

Elvis Cuevas ◽

Susan M. Lantz ◽

Merle G. Paule ◽

Syed F. Ali

Keyword(s):

Endothelial Cells ◽

Blood Brain Barrier ◽

Brain Barrier ◽

Microvascular Endothelial Cells ◽

Brain Microvascular Endothelial Cells ◽

Blood Brain ◽

Microvascular Endothelial

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Culturing of Rodent Brain Microvascular Endothelial Cells for In Vitro Modeling of the Blood-Brain Barrier

Blood-Brain Barrier - Neuromethods ◽

10.1007/978-1-4939-8946-1_3 ◽

2018 ◽

pp. 45-54

Author(s):

Malgorzata Burek ◽

Carola Y. Förster

Keyword(s):

Endothelial Cells ◽

Blood Brain Barrier ◽

Brain Barrier ◽

Microvascular Endothelial Cells ◽

Brain Microvascular Endothelial Cells ◽

In Vitro Modeling ◽

Rodent Brain ◽

Blood Brain ◽

Microvascular Endothelial

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The blood-brain barrier studied in vitro across species

PLoS ONE ◽

10.1371/journal.pone.0236770 ◽

2021 ◽

Vol 16 (3) ◽

pp. e0236770

Author(s):

Maj Schneider Thomsen ◽

Nanna Humle ◽

Eva Hede ◽

Torben Moos ◽

Annette Burkhart ◽

...

Keyword(s):

Tight Junction ◽

Cell Size ◽

Blood Brain Barrier ◽

Transferrin Receptor ◽

Brain Barrier ◽

Tight Junction Proteins ◽

Apparent Permeability ◽

Blood Brain ◽

Junction Proteins

The blood-brain barrier (BBB) is formed by brain capillary endothelial cells (BECs) supported by pericytes and astrocytes. The BBB maintains homeostasis and protects the brain against toxic substances circulating in the blood, meaning that only a few drugs can pass the BBB. Thus, for drug screening, understanding cell interactions, and pathology, in vitro BBB models have been developed using BECs from various animal sources. When comparing models of different species, differences exist especially in regards to the transendothelial electrical resistance (TEER). Thus, we compared primary mice, rat, and porcine BECs (mBECs, rBECs, and pBECs) cultured in mono- and co-culture with astrocytes, to identify species-dependent differences that could explain the variations in TEER and aid to the selection of models for future BBB studies. The BBB models based on primary mBECs, rBECs, and pBECs were evaluated and compared in regards to major BBB characteristics. The barrier integrity was evaluated by the expression of tight junction proteins and measurements of TEER and apparent permeability (Papp). Additionally, the cell size, the functionality of the P-glycoprotein (P-gp) efflux transporter, and the expression of the transferrin receptor were evaluated and compared. Expression and organization of tight junction proteins were in all three species influenced by co-culturing, supporting the findings, that TEER increases after co-culturing with astrocytes. All models had functional polarised P-gp efflux transporters and expressed the transferrin receptor. The most interesting discovery was that even though the pBECs had higher TEER than rBECs and mBECs, the Papp did not show the same variation between species, which could be explained by a significantly larger cell size of pBECs. In conclusion, our results imply that the choice of species for a given BBB study should be defined from its purpose, instead of aiming to reach the highest TEER, as the models studied here revealed similar BBB properties.

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