scholarly journals Annexin A2 Promotes Angiogenesis After Ischemic Stroke Via Annexin A2 Receptor - AKT/ERK Pathways

2021 ◽  
Author(s):  
Wenlu Li ◽  
Haoran Lin ◽  
Zexu Shen ◽  
Yun Bei ◽  
Taofeng Wei ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Ischemic Stroke ◽  
Therapeutic Target ◽  
Focal Cerebral Ischemia ◽  
Aortic Ring ◽  
Tube Formation ◽  
Annexin A2 ◽  
Protective Effects ◽  
Brain Endothelial Cells ◽  
And Migration

Abstract Promoting angiogenesis to restore circulation to the ischemic tissue is still an important therapeutic target in stroke. Here, we ask whether the Ca2+-regulated, phospholipid-and membrane-binding protein-Annexin A2 (ANXA2) may regulate angiogenesis after stroke.Compared with wild type (WT) mice, the density of microvessels in brain and the number of new vessels sprouting from aortic ring were significantly increased in Anxa2 knock-in (ANXA2+/+) mice. After focal cerebral ischemia, proliferation of brain endothelial cells in ANXA2+/+ mice was significantly elevated at 7 days post-stroke, which further improved behavioral recovery. To assess the pro-angiogenic mechanisms of ANXA2, we used brain endothelial cells cultures to investigate its effects on cell tube-formation and migration. Recombinant ANXA2 increased tube-formation and migration of brain endothelial cells either under normal condition or after OGD injury. These protective effects of recombinant ANXA2 were regulated by interaction with ANXA2 receptor (A2R), and the ability of ANXA2-A2R to activate AKT/ERK pathways. Taken together, our study indicates that ANXA2 might be involved in angiogenesis after ischemic stroke. Further investigation of ANXA2-A2R will provide a new therapeutic target for stroke.

scholarly journals Overexpression of Annexin A2 Receptor Inhibits Neovascularization via the Promotion of Krüppel-Like Transcription Factor 2

2018 ◽  
Vol 46 (4) ◽  
pp. 1617-1627 ◽  
Author(s):  
Ting Guo ◽  
Hongyuan Song ◽  
Zichang Zhao ◽  
Zhongtian Qi ◽  
Shihong Zhao
Keyword(s):  
Cell Cycle ◽  
Vascular Endothelial Growth Factor ◽  
Endothelial Cells ◽  
Transcription Factor ◽  
Aortic Ring ◽  
Tube Formation ◽  
Annexin A2 ◽  
Vascular Endothelial ◽  
Related Proteins ◽  
Endothelial Growth Factor

Background/Aims: Annexin A2 receptor (AX2R) can mediate annexin A2 signalling and induce apoptosis in a variety of cells, but its role in neovascularization (NV) remains unclear. Krüppel-like transcription factor 2 (KLF2) is known to be expressed in a range of cell types and to participate in a number of processes during development and disease, such as endothelial homeostasis, vasoregulation and vascular growth/remodelling. The aim of our study was to investigate the role of AX2R in NV and the plausible molecular mechanism. Methods: We constructed a eukaryotic overexpression plasmid for AX2R (Lenti-AX2R) by using polymerase chain reaction (PCR). The full-length human AX2R gene was transfected into human retinal endothelial cells (HRECs) and human umbilical vein endothelial cells (HUVECs) using lentivirus vectors to overexpress AX2R. All experiments were divided into three groups: control, negative control (Lenti-EGFP), and Lenti-AX2R.Cell proliferation, cell migration, tube formation, mouse aortic ring assays and mouse matrigel plug assay were applied to analyse the effect of AX2R in NV. Furthermore, we conducted flow cytometry to evaluate whether AX2R could influence the cell cycle. A series of cell cycle-related proteins including cyclin A1, cyclin B1, cyclin D1, cyclin E1, CDK1, and p-CDC2 were detected by WB. The mRNA and protein levels of KLF2, vascular endothelial growth factor (VEGF) and vascular endothelial growth factor receptor 2 (VEGFR2) were further quantified by RT-PCR and WB to reveal the possible mechanism. Results: Overexpression of AX2R significantly inhibited cell proliferation, migration and tube formation in both types of endothelial cells (ECs), HRECs and HUVECs. It also suppressed vessel sprouting in the mouse aortic ring assay and NV in mouse matrigel plug assay. Furthermore, infection with Lenti-AX2R lentivirus arrested the cell cycle in S/G2 and influenced the expression of a series of cell cycle-related proteins. We also found that the overexpression of AX2R increased the expression of KLF2, mediating VEGF and VEGFR2. Conclusions: Overexpression of AX2R contributes to the inhibition of NV via suppressing KLF2 ubiquitin-dependent protein degradation, which might therefore be a therapeutic option for NV. It could be considered more broadly as an anti-angiogenic agent in the treatment of neovascular-related diseases in the future.

scholarly journals Role of Phosphorylated HDAC4 in Stroke-Induced Angiogenesis

2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
Juan Liu ◽  
Xiang Zhou ◽  
Qing Li ◽  
Shu-Min Zhou ◽  
Bin Hu ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Histone Deacetylases ◽  
Tube Formation ◽  
Protective Mechanism ◽  
Protective Effects ◽  
Vegf Signaling ◽  
Expression Of Genes ◽  
And Migration

Acetylation or deacetylation of chromatin proteins and transcription factors is part of a complex signaling system that is involved in the control of neurological disorders. Recent studies have demonstrated that histone deacetylases (HDACs) exert protective effects in attenuating neuronal injury after ischemic insults. Class IIa HDAC4 is highly expressed in the brain, and neuronal activity depends on the nucleocytoplasmic shuttling of HDAC4. However, little is known about HDAC4 and its roles in ischemic stroke. In this study, we report that phosphorylation of HDAC4 was remarkably upregulated after stroke and blockade of HDAC4 phosphorylation with GÖ6976 repressed stroke-induced angiogenesis. Phosphorylation of HDAC4 was also increased in endothelial cells hypoxia model and suppression of HDAC4 phosphorylation inhibited the tube formation and migration of endothelial cells in vitro. Furthermore, in addition to the inhibition of angiogenesis, blockade of HDAC4 phosphorylation suppressed the expression of genes downstream of HIF-VEGF signaling in vitro and in vivo. These data indicate that phosphorylated HDAC4 may serve as an important regulator in stroke-induced angiogenesis. The protective mechanism of phosphorylated HDAC4 is associated with HIF-VEGF signaling, implicating a novel therapeutic target in stroke.

Abstract 101: MiR-4260 Promotes the Proliferation, Migration, and Tube Formation of Human Umbilical Vein Endothelial Cells

2015 ◽  
Vol 117 (suppl_1) ◽  
Author(s):  
Qi Sun ◽  
Dongcao Lv ◽  
Qiulian Zhou ◽  
Yihua Bei ◽  
Junjie Xiao
Keyword(s):  
Endothelial Cells ◽  
Target Genes ◽  
Cell Function ◽  
Umbilical Vein ◽  
Tube Formation ◽  
Endothelial Cell Function ◽  
Human Umbilical Vein ◽  
And Migration ◽  
Umbilical Vein Endothelial Cells

MicroRNAs (miRNAs, miRs), endogenous small non-coding RNA, have been shown to act as essential regulators in angiogenesis which plays important roles in improving blood flow and cardiac function following myocardial infarction. The current study investigated the potential of miR-4260 in endothelial cell function and angiogenesis using human umbilical vein endothelial cells (HUVEC). Our data demonstrated that overexpression of miR-4260 was associated with increased proliferation and migration of HUVEC using EdU incorporation assay (17.25%±1.31 vs 25.78%±1.24 in nc-mimics vs miR-4260 mimics, respectively) and wound healing assay, respectively. While downregulation of miR-4260 inhibited the proliferation (17.90%±1.37 vs 10.66%±1.41 in nc-inhibitor vs miR-4260 inhibitor, respectively) and migration of HUVEC. Furthermore, we found that miR-4260 mimics increased (129.75±3.68 vs 147±3.13 in nc-mimics vs miR-4260 mimics, respectively), while miR-4260 inhibitor decreased the tube formation of HUVECs in vitro (123.25±2.17 vs 92±4.45 in nc-inhibitor vs miR-4260 inhibitor expression, respectively). Our data indicate that miR-4260 contributes to the proliferation, migration and tube formation of endothelial cells, and might be essential regulators for angiogenesis. Further study is needed to investigate the underlying mechanism that mediates the role of miR-4260 in angiogenesis by identifying its putative downstream target genes.

scholarly journals Estrogen-Receptor-Mediated Protection of Cerebral Endothelial Cell Viability and Mitochondrial Function after Ischemic Insult in vitro

2009 ◽  
Vol 30 (3) ◽  
pp. 545-554 ◽  
Author(s):  
Jiabin Guo ◽  
Diana N Krause ◽  
James Horne ◽  
John H Weiss ◽  
Xuejun Li ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Estrogen Receptor ◽  
Endothelial Cell ◽  
Cell Viability ◽  
Mitochondrial Function ◽  
Protective Effects ◽  
Brain Endothelial Cells ◽  
Ischemic Insult ◽  
Mitochondrial Superoxide

Protective effects of estrogen against experimental stroke and neuronal ischemic insult are well-documented, but it is not known whether estrogen prevents ischemic injury to brain endothelium, a key component of the neurovascular unit. Increasing evidence indicates that estrogen exerts protective effects through mitochondrial mechanisms. We previously found 17β-estradiol (E2) to improve mitochondrial efficiency and reduce mitochondrial superoxide in brain blood vessels and endothelial cells. Thus we hypothesized E2 will preserve mitochondrial function and protect brain endothelial cells against ischemic damage. To test this, an in vitro ischemic model, oxygen-glucose deprivation (OGD)/reperfusion, was applied to immortalized mouse brain endothelial cells (bEnd.3). OGD/reperfusion-induced cell death was prevented by long-term (24, 48 h), but not short-term (0.5, 12 h), pretreatment with 10 nmol/L E2. Protective effects of E2 on endothelial cell viability were mimicked by an estrogen-receptor (ER) agonist selective for ERα (PPT), but not by one selective for ERβ (DPN). In addition, E2 significantly decreased mitochondrial superoxide and preserved mitochondrial membrane potential and ATP levels in early stages of OGD/reperfusion. All of the E2 effects were blocked by the ER antagonist, ICI-182,780. These findings indicate that E2 can preserve endothelial mitochondrial function and provide protection against ischemic injury through ER-mediated mechanisms.

scholarly journals Annexin A2 is a Robo4 ligand that modulates ARF6 activation-associated cerebral trans-endothelial permeability

2018 ◽  
Vol 39 (10) ◽  
pp. 2048-2060 ◽  
Author(s):  
Wenlu Li ◽  
Zhigang Chen ◽  
Jing Yuan ◽  
Zhanyang Yu ◽  
Chongjie Cheng ◽  
...  
Keyword(s):  
Neurological Disorders ◽  
Endothelial Permeability ◽  
Annexin A2 ◽  
Protective Effects ◽  
Brain Endothelial Cells ◽  
Cerebrovascular Injury ◽  
Junctional Proteins ◽  
Cell Membrane Protein ◽  
Intractable Problem ◽  
Adp Ribosylation Factor

Blood–brain barrier (BBB) disruption in neurological disorders remains an intractable problem with limited therapeutic options. Here, we investigate whether the endothelial cell membrane protein annexin A2 (ANXA2) may play a role in reducing trans-endothelial permeability and maintaining cerebrovascular integrity after injury. Compared with wild-type mice, the expression of cerebral endothelial junctional proteins was reduced in E15.5 and adult ANXA2 knockout mice, along with increased leakage of small molecule tracers. In human brain endothelial cells that were damaged by hypoxia plus IL-1β, treatment with recombinant ANXA2 (rA2) rescued the expression of junctional proteins and decreased trans-endothelial permeability. These protective effects were mediated in part by interactions with F-actin and VE-cadherin, and the ability of rA2 to modulate signaling via the roundabout guidance receptor 4 (Robo4)-paxillin-ADP-ribosylation factor 6 (ARF6) pathway. Taken together, these observations suggest that ANXA2 may be associated with the maintenance of endothelial tightness after cerebrovascular injury. ANXA2-mediated pathways should be further explored as potential therapeutic targets for protecting the BBB in neurological disorders.

scholarly journals Endogenous THBD (Thrombomodulin) Mediates Angiogenesis in the Ischemic Brain—Brief Report

2020 ◽  
Vol 40 (12) ◽  
pp. 2837-2844 ◽  
Author(s):  
Jan Wenzel ◽  
Dimitrios Spyropoulos ◽  
Julian Christopher Assmann ◽  
Mahtab Ahmad Khan ◽  
Ines Stölting ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Ischemic Stroke ◽  
Middle Cerebral Artery ◽  
Cerebral Artery ◽  
Soluble Form ◽  
Stroke Outcome ◽  
Brain Endothelial Cells ◽  
Ischemic Brain ◽  
Infarct Area ◽  
The Brain

Objective: THBD (thrombomodulin) is part of the anticoagulant protein C-system that acts at the endothelium and is involved in anti-inflammatory and barrier-stabilizing processes. A recombinant soluble form of THBD was shown to have protective effects in different organs, but how the endogenous THBD is regulated during ischemia, particularly in the brain is not known to date. The aim of this study was to investigate the role of THBD, especially in brain endothelial cells, during ischemic stroke. Approach and Results: To induce ischemic brain damage, we occluded the middle cerebral artery of mice. We found an increased endothelial expression of Thbd in the peri-infarct area, whereas in the core of the ischemic tissue Thbd expression was decreased compared with the contralateral side. We generated a novel Cre/loxP-based mouse line that allows for the inducible deletion of Thbd specifically in brain endothelial cells, which worsened stroke outcome 48 hours after middle cerebral artery occlusion. Unexpectedly, we found no signs of increased coagulation, thrombosis, or inflammation in the brain but decreased vessel diameters and impaired angiogenesis in the peri-infarct area that led to a reduced overall vessel length 1 week after stroke induction. Conclusions: Endogenous THBD acts as a protective factor in the brain during ischemic stroke and enhances vessel diameter and proliferation. These previously unknown properties of THBD could offer new opportunities to affect vessel function after ischemia and thereby improve stroke outcome.

scholarly journals Effective silencing of miR-126 after ischemic stroke by means of intravenous α-tocopherol–conjugated heteroduplex oligonucleotide in mice

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Motohiro Suzuki ◽  
Satoru Ishibashi ◽  
Eri Iwasawa ◽  
Takahiro Oguma ◽  
Yasuhiro Saito ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Ischemic Stroke ◽  
Endothelial Function ◽  
Therapeutic Option ◽  
New Technology ◽  
Brain Endothelial Cells ◽  
Stroke Model ◽  
Delivery Method ◽  
Ischemic Brain ◽  
Efficient Delivery

AbstractBrain endothelial cells (BECs) are involved in the pathogenesis of ischemic stroke. Recently, several microRNAs (miRNAs) in BECs were reported to regulate the endothelial function in ischemic brain. Therefore, modulation of miRNAs in BECs by a therapeutic oligonucleotide to inhibit miRNA (antimiR) could be a useful strategy for treating ischemic stroke. However, few attempts have been made to achieve this strategy via systemic route due to lack of efficient delivery-method toward BECs. Here, we have developed a new technology for delivering an antimiR into BECs and silencing miRNAs in BECs, using a mouse ischemic stroke model. We designed a heteroduplex oligonucleotide, comprising an antimiR against miRNA-126 (miR-126) known as the endothelial-specific miRNA and its complementary RNA, conjugated to α-tocopherol as a delivery ligand (Toc-HDO targeting miR-126). Intravenous administration of Toc-HDO targeting miR-126 remarkably suppressed miR-126 expression in ischemic brain of the model mice. In addition, we showed that Toc-HDO targeting miR-126 was delivered into BECs more efficiently than the parent antimiR in ischemic brain, and that it was delivered more effectively in ischemic brain than non-ischemic brain of this model mice. Our study highlights the potential of this technology as a new clinical therapeutic option for ischemic stroke.

Protective effects of carnosine against malondialdehyde-induced toxicity towards cultured rat brain endothelial cells

1997 ◽  
Vol 238 (3) ◽  
pp. 135-138 ◽  
Author(s):  
Alan R Hipkiss ◽  
Jane E Preston ◽  
David T.M Himswoth ◽  
Viki C Worthington ◽  
N.Joan Abbot
Keyword(s):  
Endothelial Cells ◽  
Rat Brain ◽  
Protective Effects ◽  
Brain Endothelial Cells ◽  
Rat Brain Endothelial Cells

scholarly journals The TDP43 CFTS Affect Brain Endothelial Cell Functions by Regulating YAP and Tight Junction Proteins in Cerebral Ischemic Injury.

2021 ◽  
Author(s):  
Xiaotian Xu ◽  
Changwen Zhang ◽  
Jianxiong Jiang ◽  
Mei Xin ◽  
Jiukuan Hao
Keyword(s):  
Endothelial Cells ◽  
Ischemic Stroke ◽  
Protein Expression ◽  
Tight Junction ◽  
Signaling Pathway ◽  
Ischemic Injury ◽  
Hippo Signaling ◽  
Brain Endothelial Cells ◽  
Hippo Signaling Pathway ◽  
Cerebral Ischemic

Abstract Background: As important components of the blood-brain barrier (BBB), brain endothelial cells (ECs) interact with pericytes, astrocytes, neurons, microglia and extracellular matrix in the neurovascular unit to maintain central nerve system (CNS) homeostasis and regulate neurological functions. Pathological changes in brain endothelium plays an important role in progression of ischemic stroke. The compromised BBB under ischemic stroke condition causes neuronal damage. However, the pathophysiological mechanisms of BBB in normal and under ischemic stroke condition has not been fully elucidated.Methods: C57bl/6 mice were subjected to 1-hour transient middle cerebral occlusion (tMCAO) model, and collected the brain samples after reperfusion for 24hours, 72hours and 1week. Lentivirus (YAP/TAZ shRNA), adenovirus (YAPS112A), TDP43 siRNA, TDP43-CTFS35 overexpression plasmid, Oxygen-glucose deprivation (OGD), and lipopolysaccharides (LPS) were applied to brain endothelial cells in vitro experiments. Brain endothelial cells (ECs) functions were tested by cell proliferation, migration and cell viability. Hippo signaling pathway was examined by immunofluorescence and western blotting.Results: The present study demonstrates that TDP43 is an essential gene to regulate brain ECs normal function, and knockdown of TDP43 reduces tight junction protein expression and inhibits brain ECs migration. Furthermore, ischemic injury and inflammation induce cytoplasmic TDP43-CTFS35 aggregation brain ECs, which weaken TDP43 full-length’s function leading to impairing tight junction (TJ) protein expression and cell migration. The expression of cytoplasmic TDP43-CTFS35 in brain ECs increased at 24 hours and 72 hours after MCAO, but disappeared at 1 week after MCAO. The expressions of TJ proteins, ZO-1 and claudin-5, and expression of P-YAP are associated with the dynamic changes of TDP43-CTFS35 expression in brain ECs after MCAO. The underlying mechanism of TDP43-CTFS35’s effects on brain ECs is that TDP43-CTFS35 turns off the Hippo signaling pathway by inhibition of PMST1/2 phosphorylation leading to de-phosphorylate YAP, and subsequently causes brain ECs functional changes.Conclusions: The present study provides new insight knowledge regarding the mechanisms of brain vascular ECs regulation and pathological change in the BBB after cerebral ischemic injury.

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