Abstract TP108: Blood Occludin Level Indicates the Extent of Early Blood Brain Barrier Damage in Ischemic Stroke

Stroke ◽  
2016 ◽  
Vol 47 (suppl_1) ◽  
Author(s):  
Rong Pan ◽  
Kewei Yu ◽  
Theodore Weatherwax1 ◽  
Handong Zheng ◽  
Yirong Yang ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Blood Brain Barrier ◽  
Evans Blue ◽  
Brain Barrier ◽  
Blue Dye ◽  
Dependent Manner ◽  
Cerebral Microvessels ◽  
Evans Blue Dye ◽  
Blood Brain ◽  
Junction Protein

Background and Purpose: Fear of symptomatic intracerebral hemorrhage (ICH) has been the primary reason for withholding tPA thrombolysis from acute ischemic stroke patients. Early blood brain barrier (BBB) damage is appreciated to be closely associated with post-thrombolysis ICH, while it remains a technical challenge for rapid assessment of BBB damage before tPA administration. Our recent data showed that cerebral ischemia induced rapid degradation of tight junction protein occludin in ischemic cerebromicrovessels. This study further investigates whether the cleaved occludin is released into the blood stream and how blood occludin levels correlate to the extent of ischemic BBB damage. Methods: Male Sprague Dawley rats were subjected to 1.5, 3, 4.5, 12 and 24 hours of middle cerebral artery occlusion (MCAO), followed by 5-min reperfusion. Blood samples were taken before and after MCAO. Blood occludin was assessed by ELISA. BBB permeability was measured by Evans blue dye leakage. Occludin cleavage was identified on immunoblots. Results: MCAO induced Evans blue dye leakage and blood occludin increase in a duration-dependent manner. Blood occludin increase concurrently occurred with the loss of occludin from ischemic cerebral microvessels. Western blot analysis identified two cleaved occludin fragments (31- and 55- kDa) in the blood. Lastly, blood occludin levels remained significantly higher than its basal level within the first 24 hours after MCAO onset. Conclusions: Our results indicate that blood occludin levels correlate well with the extents of BBB damage and thus may serve as a potential biomarker for evaluating the risk of hemorrhagic transformation before tPA administration.

Using Evans Blue Dye to Determine Blood‐Brain Barrier Integrity in Rodents

2019 ◽  
Vol 126 (1) ◽  
Author(s):  
Mariana Pereira de Souza Goldim ◽  
Amanda Della Giustina ◽  
Fabricia Petronilho
Keyword(s):  
Blood Brain Barrier ◽  
Evans Blue ◽  
Brain Barrier ◽  
Blue Dye ◽  
Barrier Integrity ◽  
Evans Blue Dye ◽  
Blood Brain ◽  
Blood Brain Barrier Integrity

The influence of nimodipine on cerebral blood flow autoregulation and blood-brain barrier

1988 ◽  
Vol 69 (6) ◽  
pp. 919-922 ◽  
Author(s):  
Hans-Georg Höllerhage ◽  
Michael R. Gaab ◽  
Matthias Zumkeller ◽  
Gerhard F. Walter
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Blood Brain Barrier ◽  
Evans Blue ◽  
Brain Barrier ◽  
Control Group ◽  
Blue Dye ◽  
Evans Blue Dye ◽  
Blood Brain ◽  
Anesthetized Rats

✓ Twenty anesthetized rats were randomly assigned to a nimodipine-treated group or a control group of 10 rats each. Local cerebral blood flow (lCBF) was measured by means of a surface electrode using the hydrogen clearance technique. Systemic arterial pressure (SAP) was varied with administration of norfenefrine or by hemorrhage in order to obtain SAP/cerebral blood flow (CBF) curves under different conditions. In the control group, a typical autoregulation curve was obtained with an lCBF plateau between 70 and 120 mm Hg SAP. The nimodipine-treated animals, however, showed only a slight diminution in the slope of the curve but no real plateau, indicating impairment of CBF autoregulation. In another series, 20 anesthetized rats were randomly assigned to a treatment group or a control group of 10 animals each. Intravenous Evans blue dye was used as a tracer for blood-brain barrier (BBB) function. In both groups, SAP was raised to a level of 180 mm Hg with administration of norfenefrine for 6 minutes. Extravasation of significantly more Evans blue dye was observed in the nimodipine group than in the control group, indicating impairment of the BBB. It is concluded that nimodipine may impair CBF autoregulation, allowing damage to the BBB under hypertensive conditions.

scholarly journals A Study of the Pathogenesis and Prevention of Central Pontine Myelinolysis in a Rat Model

2006 ◽  
Vol 34 (3) ◽  
pp. 264-271 ◽  
Author(s):  
Q-H Ke ◽  
T-B Liang ◽  
J Yu ◽  
S-S Zheng
Keyword(s):  
Hypertonic Saline ◽  
Blood Brain Barrier ◽  
Evans Blue ◽  
Central Pontine Myelinolysis ◽  
Brain Barrier ◽  
Blue Dye ◽  
Evans Blue Dye ◽  
Pontine Myelinolysis ◽  
Demyelinating Lesions ◽  
Central Pontine

The development of central pontine myelinolysis was studied in rats. Severe hyponatraemia was induced using vasopressin tannate and 2.5% dextrose in water and then rapidly corrected with hypertonic saline alone, hypertonic saline and dexamethasone simultaneously, or hypertonic saline plus dexamethasone 24 h later. The permeability of the blood-brain barrier was evaluated using the extravasation of Evans blue dye and the expression of inducible nitric oxide synthase (iNOS) in the brain was examined using Western blot analysis. Histological sections were examined for demyelinating lesions. In rats receiving hypertonic saline alone, Evans blue dye content and expression of iNOS began to increase 6 and 3 h, respectively, after rapid correction of hyponatraemia and demyelinating lesions were seen. When dexamethasone was given simultaneously with hypertonic saline, these increases were inhibited and demyelinating lesions were absent. These effects were lost if dexamethasone injection was delayed. Disruption of the blood-brain barrier and increased iNOS expression may be involved in the pathogenesis of central pontine myelinolysis, and early treatment with dexamethasone may help prevent the development of central pontine myelinolysis.

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.

Abstract TP340: The Level of Occludin in Blood as a Potential Biomarker for Blood-Brain Barrier Damage and Predicting Hemorrhage Transformation After Acute Ischemic Stroke

Stroke ◽  
2020 ◽  
Vol 51 (Suppl_1) ◽  
Author(s):  
Zhifeng Qi ◽  
Ke Jian Liu
Keyword(s):  
Ischemic Stroke ◽  
Acute Ischemic Stroke ◽  
Blood Brain Barrier ◽  
Brain Infarction ◽  
Critical Role ◽  
Onset Time ◽  
Brain Barrier ◽  
Cerebral Microvessels ◽  
Blood Brain ◽  
Potential Biomarker

Fear of hemorrhage transformation (HT) has been the primary reason for withholding the effective recanalization therapies (thrombolysis or thrombectomy) from most acute ischemic stroke (AIS) patients. Currently there is no reliable indicator available to predict HT before recanalization. The degradation of tight junction proteins plays a critical role in blood-brain barrier (BBB) disruption in ischemic stroke. We hypothesize that since occludin fragment in peripheral blood is derived from the degradation of occludin on cerebral microvessels, elevated blood occludin level directly reflects BBB disruption and may serve as a biomarker for BBB damage to predict the risk of HT after recanalization. In this study, we determined occludin fragment in the blood of rats, non-human primates and human patients after AIS using ELISA assay, and evaluated its level with BBB damage, HT, and other neurological outcomes. We found that ischemia induced rapid occludin degradation and BBB disruption, while occludin fragment was released into the blood circulation. Cerebral ischemia resulted in a dramatic increase of occludin fragments in rat blood samples after 4-hr ischemia, which was correlated well with occludin loss from ischemic cerebral microvessels. In the blood sample from ischemic rhesus monkeys, occludin level significantly increased after 2h ischemia from baseline, which correlated well with brain infarction shown in MRI images. We further collected the sera of AIS patients as early as they arrived at hospital. Our results indicated that the level of occludin increased in accord with ischemia onset time and neurological dysfunctions. The level of blood occludin in AIS patients with HT was much higher that those without HT. Together, our findings from rats, non-human primates and patients suggest that the level of occludin fragment in blood could serve as a biomarker for HT and neurological outcome following AIS, which could be used to safely guide recanalization for AIS in the clinic.

scholarly journals FGF21 Protects against Aggravated Blood-Brain Barrier Disruption after Ischemic Focal Stroke in Diabetic db/db Male Mice via Cerebrovascular PPARγ Activation

2020 ◽  
Vol 21 (3) ◽  
pp. 824 ◽  
Author(s):  
Yinghua Jiang ◽  
Li Lin ◽  
Ning Liu ◽  
Qingzhi Wang ◽  
Jing Yuan ◽  
...  
Keyword(s):  
Dna Binding ◽  
Blood Brain Barrier ◽  
Binding Activity ◽  
Brain Barrier ◽  
Fibroblast Growth Factor 21 ◽  
Mrna Levels ◽  
Dependent Manner ◽  
Dna Binding Activity ◽  
Blood Brain ◽  
Junction Protein

Recombinant fibroblast growth factor 21 (rFGF21) has been shown to be potently beneficial for improving long-term neurological outcomes in type 2 diabetes mellitus (T2DM) stroke mice. Here, we tested the hypothesis that rFGF21 protects against poststroke blood–brain barrier (BBB) damage in T2DM mice via peroxisome proliferator-activated receptor gamma (PPARγ) activation in cerebral microvascular endothelium. We used the distal middle cerebral occlusion (dMCAO) model in T2DM mice as well as cultured human brain microvascular endothelial cells (HBMECs) subjected to hyperglycemic and inflammatory injury in the current study. We detected a significant reduction in PPARγ DNA-binding activity in the brain tissue and mRNA levels of BBB junctional proteins and PPARγ-targeting gene CD36 and FABP4 in cerebral microvasculature at 24 h after stroke. Ischemic stroke induced a massive BBB leakage two days after stroke in T2DM mice compared to in their lean controls. Importantly, all abnormal changes were significantly prevented by rFGF21 administration initiated at 6 h after stroke. Our in vitro experimental results also demonstrated that rFGF21 protects against hyperglycemia plus interleukin (IL)-1β-induced transendothelial permeability through upregulation of junction protein expression in an FGFR1 activation and PPARγ activity elevation-dependent manner. Our data suggested that rFGF21 has strong protective effects on acute BBB leakage after diabetic stroke, which is partially mediated by increasing PPARγ DNA-binding activity and mRNA expression of BBB junctional complex proteins. Together with our previous investigations, rFGF21 might be a promising candidate for treating diabetic stroke.

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