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.

Blood-Brain Barrier Dysfunction after Primary Blast Injury in vitro

2013 ◽  
Vol 30 (19) ◽  
pp. 1652-1663 ◽  
Author(s):  
Christopher D. Hue ◽  
Siqi Cao ◽  
Syed F. Haider ◽  
Kiet V. Vo ◽  
Gwen B. Effgen ◽  
...  
Keyword(s):  
Blood Brain Barrier ◽  
Blast Injury ◽  
Brain Barrier ◽  
Barrier Dysfunction ◽  
Primary Blast ◽  
Blood Brain

Repeated Primary Blast Injury Causes Delayed Recovery, but not Additive Disruption, in an In Vitro Blood–Brain Barrier Model

2014 ◽  
Vol 31 (10) ◽  
pp. 951-960 ◽  
Author(s):  
Christopher D. Hue ◽  
Siqi Cao ◽  
Cameron R. “Dale” Bass ◽  
David F. Meaney ◽  
Barclay Morrison
Keyword(s):  
Blood Brain Barrier ◽  
Blast Injury ◽  
Brain Barrier ◽  
Primary Blast ◽  
Blood Brain ◽  
Blood Brain Barrier Model ◽  
Delayed Recovery ◽  
Injury Causes ◽  
Barrier Model

Abstract T P250: Role of Autophagy in Blood-Brain Barrier Disruption and Tight Junction Degradation Under Ischemic Condition

Stroke ◽  
2015 ◽  
Vol 46 (suppl_1) ◽  
Author(s):  
Kyeong-A Kim ◽  
Young-Jun Shin ◽  
Eun-Sun Kim ◽  
Muhammad Akram ◽  
Dabi Noh ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Tight Junction ◽  
Cell Viability ◽  
Blood Brain Barrier ◽  
Neuronal Damage ◽  
Cell Damage ◽  
Brain Barrier ◽  
Blood Brain ◽  
Junction Protein

During ischemic stroke, the integrity of blood-brain barrier (BBB), which shows selective permeability for substances to brain, is significantly damaged amplifying ischemic neuronal damage. There have been attempts to identify the exact mechanism ischemic BBB disruption to minimize brain damage under ischemic stroke. Autophagy is catabolic process which involves degradation and recycling of damaged or unnecessary organelles. However, excessive autophagy can induce cell damage and death under pathological conditions such as ischemia. In this study, we evaluated if autophagy is a key mechanism of BBB dysfunction under ischemic stroke. In vitro BBB model of bEnd.3 cells were exposed to oxygen-glucose deprivation (OGD), an ischemic mimic condition. After exposure to OGD for 18 hours, cell viability was significantly decreased and cellular permeability was impaired. The conversion of LC3-I to LC3-II and puncta of LC3 in bEnd.3 were increased, demonstrating that autophagy is induced under ischemic condition. Modulation of autophagy by 3-methyladenine, an autophagy inhibitor, reversed the conversion of LC3 as well as decreased cell viability, suggesting that autophagy involves in ischemic BBB damage. The level of occludin, a tight junction protein in BBB, was decreased after OGD, and this was reversed by inhibition of autophagy. Our findings showed that induction of autophagy might contribute to increased permeability through occludin degradation in brain endothelial cells under ischemia, providing a new mechanism of BBB disruption in ischemic stroke.

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.

Abstract TP256: Mouse Model of Uremic Cerebral Microbleeds

Stroke ◽  
2016 ◽  
Vol 47 (suppl_1) ◽  
Author(s):  
Wei Ling Lau ◽  
Mary Tarbiat-Boldaji ◽  
Hayley Smalls ◽  
Ane Nunes ◽  
Javad Savoj ◽  
...  
Keyword(s):  
Mouse Model ◽  
Tight Junction ◽  
Blood Brain Barrier ◽  
Cerebral Microbleeds ◽  
Brain Barrier ◽  
Barrier Integrity ◽  
Blood Brain ◽  
Increased Risk ◽  
Junction Protein ◽  
Blood Brain Barrier Integrity

Introduction: Cerebral microbleeds are more common in chronic kidney disease (CKD) and dialysis patients compared to the general population. Diminished kidney function alone appears to be a risk factor for microbleeds, independent of age and hypertension. Microbleed burden in CKD patients is associated with increased risk of future hemorrhagic stroke and with cognitive dysfunction. The mechanisms that drive uremic microbleed formation are unclear. Hypothesis: We hypothesized that CKD mice are predisposed to develop cerebral microhemorrhages (the pathologic substrate of microbleeds), and that a standardized inflammatory stimulus (lipopolysaccharide, LPS) will amplify microhemorrhage burden in CKD mice compared to non-CKD controls (CTL). We also hypothesized that uremia induces depletion of tight junction proteins, altering blood-brain barrier integrity and representing a potential mechanism of microbleed formation. Methods: Animal groups included CTL (n=3), CKD (n=3), CTL+LPS (n=5) and CKD+LPS (n=5). CKD induction in male C57BL/6 mice was achieved via nephrotoxic adenine diet x18 days. Two weeks following CKD induction, CKD and control mice were treated with LPS 1 mg/kg i.p. dosed at 0, 6 and 24 hours. Brains were harvested one week after LPS injections and 40-micron sections were stained using Prussian blue to identify microhemorrhages. Immunohistochemistry was performed for the blood-brain barrier tight junction protein claudin-5. Results: CKD mice had significantly elevated blood urea nitrogen, and tubulointerstitial fibrosis was present on kidney histology. Total number of microhemorrhages per brain was 2.3±1.5 (mean ± standard error of the mean) for CTL mice, 8.3±1.5 for CKD mice, 23.2±4.2 for CTL+LPS mice, and 27.6±6.2 for CKD+LPS mice (p<0.05 for CKD+LPS vs. CTL). Immunostaining showed decreased claudin-5 expression in CKD mice compared to CTL. Conclusions: We have generated a mouse model that will facilitate future mechanistic studies in the field of uremic microbleeds. Our initial findings suggest that CKD alters blood-brain barrier integrity and that inflammation amplifies development of microbleeds in CKD.

scholarly journals Effects of fasudil on blood-brain barrier integrity

2021 ◽  
Author(s):  
Kei Sato ◽  
Shinsuke Nakagawa ◽  
Yoichi Morofuji ◽  
Yuki Matsunaga ◽  
Takashi Fujimoto ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Ischemic Stroke ◽  
Tight Junction ◽  
Acute Ischemic Stroke ◽  
Blood Brain Barrier ◽  
Tight Junction Protein ◽  
Brain Barrier ◽  
Blood Brain ◽  
Junction Protein ◽  
Culture Models

Abstract Background Cerebral infarction accounts for 85% of all stroke cases. Even in an era of rapid and effective recanalization using an intravascular approach, the majority of patients have poor functional outcomes. Thus, there is an urgent need for the development of therapeutic agents to treat acute ischemic stroke. We evaluated the effect of fasudil, a Rho kinase inhibitor, on blood brain barrier (BBB) functions under normoxia or oxygen-glucose deprivation (OGD) conditions using a primary cell-based in vitro BBB model. Medhods: BBB models from rat primary cultures (brain capillary endothelial cells, astrocytes, and pericytes) were subjected to either normoxia or 6-hour OGD/24-hour reoxygenation. To assess the effects of fasudil on BBB functions, we evaluated real time impedance, transendothelial electrical resistance (TEER), sodium fluorescein permeability, and tight junction protein expression using immunohistochemistry and western blotting. Lastly, to understand the observed protective mechanism on BBB functions by fasudil we examined the role of cyclooxygenase-2 and thromboxane A2 receptor agonist U-46619 in BBB-forming cells. Results We found that treatment with 0.3–30 µM of fasudil increased cellular impedance. Fasudil enhanced barrier properties in a concentration-dependent manner, as measured by an increased (TEER) and decreased permeability. Fasudil also increased the expression of tight junction protein claudin-5. Reductions in TEER and increased permeability were observed after OGD/reoxygenation exposure in mono- and co-culture models. The improvement in BBB integrity by fasudil was confirmed in both of the models, but was significantly higher in the co-culture than in the monoculture model. Treatment with U-46619 did not show significant changes in TEER in the monoculture model, whereas it showed a significant reduction in TEER in the co-culture model. Fasudil significantly improved the U-46619-induced TEER reduction in the co-culture models. Pericytes and astrocytes have opposite effects on endothelial cells and may contribute to endothelial injury in hyperacute ischemic stroke. Overall, fasudil protects the integrity of BBB both by a direct protective effect on endothelial cells and by a pathway mediated via pericytes and astrocytes. Conclusions Our findings suggest that fasudil is a BBB-protective agent against acute ischemic stroke.

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.

Sign in / Sign up

Export Citation Format

Share Document