scholarly journals Inhibiting YAP in Endothelial Cells From Entering the Nucleus Attenuates Blood-Brain Barrier Damage During Ischemia-Reperfusion Injury

2021 ◽  
Vol 12 ◽  
Author(s):  
Shuaishuai Gong ◽  
Huifen Ma ◽  
Fan Zheng ◽  
Juan Huang ◽  
Yuanyuan Zhang ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Ischemic Stroke ◽  
Blood Brain Barrier ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Brain Barrier ◽  
Critical Event ◽  
Blue Dye ◽  
Triphenyltetrazolium Chloride ◽  
Blood Brain

Blood-brain barrier (BBB) damage is a critical event in ischemic stroke, contributing to aggravated brain damage. Endothelial cell form a major component of the BBB, but its regulation in stroke has yet to be clarified. We investigated the function of Yes-associated protein 1 (YAP) in the endothelium on BBB breakdown during cerebral ischemia/reperfusion (I/R) injury. The effects of YAP on BBB dysfunction were explored in middle cerebral artery occlusion/reperfusion (MCAO/R)-injury model mice and using brain microvascular endothelial cells (BMEC) exposed to oxygen-glucose deprivation/reoxygenation (OGD/R) injury. The degree of brain injury was estimated using staining (2,3,5-Triphenyltetrazolium chloride, hematoxylin and eosin) and the detection of cerebral blood flow. BBB breakdown was investigated by examining the leakage of Evans Blue dye and evaluating the expression of tight junction (TJ)-associated proteins and matrix metallopeptidase (MMP) 2 and 9. YAP expression was up-regulated in the nucleus of BMEC after cerebral I/R injury. Verteporfin (YAP inhibitor) down-regulated YAP expression in the nucleus and improved BBB hyperpermeability and TJ integrity disruption stimulated by cerebral I/R. YAP-targeted small interfering RNA (siRNA) exerted the same effects in BMEC cells exposed to OGD/R injury. Our findings provide new insights into the contributions made by YAP to the maintenance of BBB integrity and highlight the potential for YAP to serve as a therapeutic target to modulate BBB integrity following ischemic stroke and related cerebrovascular diseases.

scholarly journals Reduced Levels of A20 Protein Prompted RIPK1-Dependent Apoptosis of Vascular Endothelial Cells and Blood–Brain Barrier Breakdown in CIRI

2021 ◽  
Author(s):  
Ying Li ◽  
Chaonan Yang ◽  
Yuting Yang ◽  
Huijie Li ◽  
Xiaohui Wu ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Blood Brain Barrier ◽  
Ischemia Reperfusion Injury ◽  
Vascular Endothelial Cells ◽  
Ischemia Reperfusion ◽  
Brain Barrier ◽  
Vascular Endothelial ◽  
Ischemic Reperfusion ◽  
Blood Brain ◽  
Cerebral Ischemia Reperfusion Injury

Abstract Blood–brain barrier (BBB) leakage is an important cause of the exacerbation of pathological features of ischemia and reperfusion. However, the specific mechanism of cell death of vascular endothelial cells is not clear. It was found that ischemic reperfusion resulted in RIPK1 activation in vascular endothelial cells and induced cells to undergo subsequent RIPK1-dependent apoptosis (RDA). Inhibition of RIPK1 significantly reduced BBB breakdown and brain damage. The aim of this study is to investigate the mechanism of RIPK1 in the BBB leakage during the ischemia reperfusion procedure.In this study, the role of RIPK1 in the development of cerebral ischemia reperfusion injury (CIRI) was investigated by immunohistochemical approaches on KO or mutant mice. It was discovered by proteomics that autophagy activation resulting from ischemia and reperfusion significantly downregulated the level of A20 protein in vascular endothelial cells. A20 is an important protein that regulates RIPK1 and RDA. It was hypothesized that activation of autophagy in vascular endothelial cells caused by ischemic reperfusion led to a decrease in A20 protein, which, in turn, caused the activation of RIPK1 and the occurrence of RDA, leading to leakage of the blood–brain barrier. The findings in this study revealed the role of RIPK1 in vascular endothelial cell death and BBB leakage upon cerebral ischemia reperfusion injury (CIRI), and these findings provide a novel perspective for the treatment of ischemic reperfusion.

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.

Intravenous Fibroblast Growth Factor Penetrates the Blood-Brain Barrier and Protects Hippocampal Neurons Against Ischemia-Reperfusion Injury

1998 ◽  
Vol 49 (1) ◽  
pp. 77-84 ◽  
Author(s):  
Pedro Cuevas M.D., Ph.D., F.A.C.A. ◽  
Fernando Carceller M.D., Ph.D. ◽  
Isabel Muñoz-Willery B.Sc., Ph.D. ◽  
Guillermo Giménez-Gallego B.Sc., Ph.D.
Keyword(s):  
Growth Factor ◽  
Reperfusion Injury ◽  
Fibroblast Growth Factor ◽  
Blood Brain Barrier ◽  
Hippocampal Neurons ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Brain Barrier ◽  
Fibroblast Growth ◽  
Blood Brain

scholarly journals Lipid Reshaping and Lipophagy Are Induced in a Modeled Ischemia-Reperfusion Injury of Blood Brain Barrier

2019 ◽  
Vol 20 (15) ◽  
pp. 3752 ◽  
Author(s):  
Elena Lonati ◽  
Paola Antonia Corsetto ◽  
Gigliola Montorfano ◽  
Stefania Zava ◽  
Tatiana Carrozzini ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Blood Brain Barrier ◽  
Ischemia Reperfusion Injury ◽  
Neutral Lipids ◽  
Ischemia Reperfusion ◽  
Neurovascular Unit ◽  
Standard Condition ◽  
Brain Barrier ◽  
Inflammatory Status ◽  
Blood Brain

Ischemic-reperfusion (I/R) injury induced a remodeling of protein and lipid homeostasis, under oxidative stress and inflammatory status. Starvation occurring during I/R is a condition leading to autophagy activation, which allows abnormal material clearance or amino acid, or both, and fatty acid (FA) recycling essential for survival. This study investigated the lipid reshaping, peroxidation, and related-signaling pathways, in rat brain endothelial cells (RBE4) subjected to 3 h of oxygen and glucose deprivation (OGD) and restoration of standard condition (I/R in vitro model). Lipids and proteins were analyzed after 1 or 24 h of oxygen and nutrient restoration. Together with the oxidative stress and inflammatory status, I/R injury induced a reshaping of neutral lipids and biogenesis of lipid droplets (LD) with excessive lipid storage. The increase of LC3-II/LC3-I ratio, an autophagy marker, and LC3 co-localization with LD suggest the activation of lipophagy machinery to counteract the cell engulfment. Lipophagy leads to cholesterol ester (CE) hydrolysis, increasing free cholesterol (FC) secretion, which occurred by specific transporters or unconventional exocytosis pathways, or both. Here, we propose that an unconventional spreading of FC and other lipid metabolites may influence the neurovascular unit (NVU) cells, contributing to Blood brain barrier (BBB) alteration or adaptation, or both, to the cumulative effects of several transient ischemia.

scholarly journals Targeting blood-brain barrier leakage for visualizing , monitoring, and evaluating ischemia reperfusion injury with Rus-Tc99m Probe

2020 ◽  
Author(s):  
Shuaishuai Gong ◽  
Jieman Wang ◽  
Zhuo Chen ◽  
Xuewei Pan ◽  
Yunhao Wu ◽  
...  
Keyword(s):  
Real Time ◽  
Blood Brain Barrier ◽  
Ischemia Reperfusion Injury ◽  
Protective Efficacy ◽  
Ischemia Reperfusion ◽  
In Vitro Study ◽  
Brain Barrier ◽  
Blue Staining ◽  
Blood Brain

Abstract Background : Cerebral ischemia-reperfusion (I/R) injury as a serious threat to human health is characterized by cerebral endothelial leakage, as a result of the damage of blood-brain barrier (BBB). It is thus quite attractive to realize real-time monitoring of BBB damage for therapeutic surveillance.Methods : In this study, a radioactive probe is constructed by conjugating ruscogenin (Rus), a neuroprotectants, to technetium-99m (Tc 99m ) to assess the damage of cerebral endothelial in BBB.Results : In vitro study proves that the probe can penetrate more efficiently in damaged BBB. Then, longitudinal nuclear imaging distinguishes mice with BBB leakage from normal ones, which is validated by evans blue staining of brain tissue. Higher nuclear signal also correlates with poorer blood circulation in brain. Further, by visualizing brain signal during drug treatment, the probe finds that the most obvious protective efficacy of Rus occurs at 12 h post administration, which is superior than edaravone (Edara).Conclusion : Altogether, the probe is promising to monitor I/R injury real-time by radioactive-imaging of BBB integrity. Importantly, Rus as a neuroprotectants may serve as a potential theranostic agent for I/R treatment.

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