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Pang B, Wu L, Peng Y. In vitro modelling of the neurovascular unit for ischemic stroke research: Emphasis on human cell applications and 3D model design. Exp Neurol 2024; 381:114942. [PMID: 39222766 DOI: 10.1016/j.expneurol.2024.114942] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2024] [Revised: 07/16/2024] [Accepted: 08/29/2024] [Indexed: 09/04/2024]
Abstract
Ischemic stroke has garnered global medical attention as one of the most serious cerebrovascular diseases. The mechanisms involved in both the development and recovery phases of ischemic stroke are complex, involving intricate interactions among different types of cells, each with its own unique functions. To better understand the possible pathogenesis, neurovascular unit (NVU), a concept comprising neurons, endothelial cells, mural cells, glial cells, and extracellular matrix components, has been used in analysing various brain diseases, particularly in ischemic stroke, aiming to depict the interactions between cerebral vasculature and neural cells. While in vivo models often face limitations in terms of reproducibility and the ability to precisely mimic human pathophysiology, it is now important to establish in vitro NVU models for ischemic stroke research. In order to accurately portray the pathological processes occurring within the brain, a diverse array of NVU 2D and 3D in vitro models, each possessing unique characteristics and advantages, have been meticulously developed. This review presents a comprehensive overview of recent advancements in in vitro models specifically tailored for investigating ischemic stroke. Through a systematic categorization of these developments, we elucidate the intricate links between NVU components and the pathogenesis of ischemic stroke. Furthermore, we explore the distinct advantages offered by innovative NVU models, notably 3D models, which closely emulate in vivo conditions. Additionally, an examination of current therapeutic modalities for ischemic stroke developed utilizing in vitro NVU models is provided. Serving as a valuable reference, this review aids in the design and implementation of effective in vitro models for ischemic stroke research.
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Affiliation(s)
- Bo Pang
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100050, China
| | - Lei Wu
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100050, China
| | - Ying Peng
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100050, China.
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2
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Michinaga S. Drug Discovery Research for Traumatic Brain Injury Focused on Functional Molecules in Astrocytes. Biol Pharm Bull 2024; 47:350-360. [PMID: 38296549 DOI: 10.1248/bpb.b23-00731] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/15/2024]
Abstract
Traumatic brain injury (TBI) is severe damage to the head caused by traffic accidents, falls, and sports. Because TBI-induced disruption of the blood-brain barrier (BBB) causes brain edema and neuroinflammation, which are major causes of death or serious disabilities, protection and recovery of BBB function may be beneficial therapeutic strategies for TBI. Astrocytes are key components of BBB integrity, and astrocyte-derived bioactive factors promote and suppress BBB disruption in TBI. Therefore, the regulation of astrocyte function is essential for BBB protection. In the injured cerebrum of TBI model mice, we found that the endothelin ETB receptor, histamine H2 receptor, and transient receptor potential vanilloid 4 (TRPV4) were predominantly expressed in reactive astrocytes. We also showed that repeated administration of an ETB receptor antagonist, H2 receptor agonist, and TRPV4 antagonist alleviated BBB disruption and brain edema in a TBI mouse model. Furthermore, these drugs decreased the expression levels of astrocyte-derived factors promoting BBB disruption and increased the expression levels of astrocyte-derived protective factors in the injured cerebrum after TBI. These results suggest that the ETB receptor, H2 receptor, and TRPV4 are molecules that regulate astrocyte function, and might be attractive candidates for the development of therapeutic drugs for TBI.
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3
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Li Y, Liu C, Chen Z, Lin H, Li X. Netrin-1 protects blood-brain barrier (BBB) integrity after cerebral ischemia-reperfusion by activating the Kruppel-like factor 2 (KLF2)/occludin pathway. J Biochem Mol Toxicol 2024; 38:e23623. [PMID: 38229322 DOI: 10.1002/jbt.23623] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2023] [Revised: 11/04/2023] [Accepted: 12/14/2023] [Indexed: 01/18/2024]
Abstract
Ischemia/reperfusion (I/R)-induced neural damage and neuroinflammation have been associated with pathological progression during stroke. Netrin-1 is an important member of the family of laminin-related secreted proteins, which plays an important role in governing axon elongation. However, it is unknown whether Netrin-1 possesses a beneficial role in stroke. Here, we employed the middle cerebral artery occlusion (MCAO) model to study the function of Netrin-1 in alleviating brain injuries. Our results demonstrate that Netrin-1 rescued poststroke neurological deficits and inhibited production of the inflammatory cytokines such as interleukin 6 (IL-6) and endothelial chemokine (C-X-C motif) ligand 1 (Cxcl1). Importantly, Netrin-1 protected against MCAO-induced dysfunction of the blood-brain barrier (BBB) in mice and a reduction in the expression of the tight junction (TJ) protein occludin. Additionally, we report that Netrin-1 could ameliorate oxygen-glucose deprivation/reoxygenation (OGD/R)-induced injury and prevent aggravation in endothelial monolayer permeability in bEnd.3 human brain microvascular endothelial cells (HBMVECs). Mechanistically, Netrin-1 ameliorated OGD/R-induced decrease in occludin and Kruppel-like factor 2 (KLF2) in HBMVECs. Notably, silencing of KLF2 abolished the beneficial effects of Netrin-1 in protecting endothelial permeability and occludin expression, suggesting that these effects are mediated by KLF2. In conclusion, our findings suggest that Netrin-1 could constitute a novel therapeutic strategy for ischemic stroke.
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Affiliation(s)
- Yuanxiao Li
- Department of Neurology, Fujian Medical University Union Hospital, Fuzhou, Fujian Province, China
| | - Changyun Liu
- Department of Neurology, Fujian Medical University Union Hospital, Fuzhou, Fujian Province, China
| | - Zhiting Chen
- Department of Neurology, Fujian Medical University Union Hospital, Fuzhou, Fujian Province, China
| | - Hanbin Lin
- Department of Neurology, Fujian Medical University Union Hospital, Fuzhou, Fujian Province, China
| | - Xiaofeng Li
- Department of Neurology, Fujian Medical University Union Hospital, Fuzhou, Fujian Province, China
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4
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Han X, Zhou H, Yin J, Zhu J, Yang J, Wan H. Network Analysis and Experimental Verification of the Mechanisms of Hydroxysafflor Yellow A in Ischemic Stroke Following Atherosclerosis. Molecules 2023; 28:7829. [PMID: 38067558 PMCID: PMC10707860 DOI: 10.3390/molecules28237829] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2023] [Revised: 11/19/2023] [Accepted: 11/22/2023] [Indexed: 12/18/2023] Open
Abstract
Hydroxysafflor yellow A (HSYA) is derived from Carthamus tinctorius L. (Honghua in Chinese) and is used to treat cardiovascular and cerebrovascular disease. However, the mechanism by which HSYA treats ischemic stroke following atherosclerosis (ISFA) remains unclear. The targets and pathways of HSYA against ISFA were obtained using network analysis. A total of 3335 potential IFSA-related targets were predicted using the GenCards and Drugbank databases, and a total of 88 potential HSYA-related targets were predicted using the Swiss Target Prediction database. A total of 62 HSYA-related targets against IFSA were obtained. The network was composed of HSYA, 62 targets, and 20 pathways. The top 20 targets were constructed via the protein-protein interaction (PPI) network. Gene Ontology analysis revealed that the targets were involved in signal transduction, protein phosphorylation, the cytoplasm, the plasma membrane, the cytosol, zinc ion binding, ATP binding, protein kinase binding/activity, and enzyme binding. The Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis revealed that the pathways were associated with cancer, inflammatory mediator regulation of the transient receptor potential channels, and microRNA in cancer. Additionally, molecular docking indicated that HSYA mainly interacts with five targets, namely interleukin 1 beta (IL-1β), signal transducer and activator of transcription 3 (STAT3), E1A-binding protein p300 (EP300), protein kinase C alpha (PRKCA), and inhibitor of nuclear factor kappa B kinase subunit beta (IKBKB). In animal experiments, HSYA administration ameliorated the infarct size, neurological deficit score, histopathological changes, carotid intima-media thickness (IMT), and blood lipid level (total cholesterol and triglycerides). Immunochemistry and quantitative PCR showed that HSYA intervention downregulated the expression of STAT3, EP300, PRKCA, and IKBKB, and the enzyme-linked immunoassay showed reduced IL-1β levels. The findings of this study provide a reference for the development of anti-ISFA drugs.
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Affiliation(s)
| | | | | | | | | | - Haitong Wan
- School of Basic Medical Sciences, Zhejiang Chinese Medical University, Hangzhou 310053, China; (X.H.); (H.Z.)
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Torices S, Daire L, Simon S, Naranjo O, Mendoza L, Teglas T, Fattakhov N, Adesse D, Toborek M. Occludin: a gatekeeper of brain Infection by HIV-1. Fluids Barriers CNS 2023; 20:73. [PMID: 37840143 PMCID: PMC10577960 DOI: 10.1186/s12987-023-00476-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2023] [Accepted: 10/09/2023] [Indexed: 10/17/2023] Open
Abstract
Compromised structure and function of the blood-brain barrier (BBB) is one of the pathological hallmarks of brain infection by HIV-1. BBB damage during HIV-1 infection has been associated with modified expression of tight junction (TJ) proteins, including occludin. Recent evidence indicated occludin as a redox-sensitive, multifunctional protein that can act as both an NADH oxidase and influence cellular metabolism through AMPK kinase. One of the newly identified functions of occludin is its involvement in regulating HIV-1 infection. Studies suggest that occludin expression levels and the rate of HIV-1 infection share a reverse, bidirectional relationship; however, the mechanisms of this relationship are unclear. In this review, we describe the pathways involved in the regulation of HIV-1 infection by occludin. We propose that occludin may serve as a potential therapeutic target to control HIV-1 infection and to improve the lives of people living with HIV-1.
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Affiliation(s)
- Silvia Torices
- Department of Biochemistry and Molecular Biology, University of Miami School of Medicine, 528E Gautier Bldg. 1011 NW 15th Street Miami, Miami, FL, 11336, USA
| | - Leah Daire
- Department of Biochemistry and Molecular Biology, University of Miami School of Medicine, 528E Gautier Bldg. 1011 NW 15th Street Miami, Miami, FL, 11336, USA
| | - Sierra Simon
- Department of Biochemistry and Molecular Biology, University of Miami School of Medicine, 528E Gautier Bldg. 1011 NW 15th Street Miami, Miami, FL, 11336, USA
| | - Oandy Naranjo
- Department of Biochemistry and Molecular Biology, University of Miami School of Medicine, 528E Gautier Bldg. 1011 NW 15th Street Miami, Miami, FL, 11336, USA
| | - Luisa Mendoza
- Department of Biochemistry and Molecular Biology, University of Miami School of Medicine, 528E Gautier Bldg. 1011 NW 15th Street Miami, Miami, FL, 11336, USA
| | - Timea Teglas
- Department of Biochemistry and Molecular Biology, University of Miami School of Medicine, 528E Gautier Bldg. 1011 NW 15th Street Miami, Miami, FL, 11336, USA
| | - Nikolai Fattakhov
- Department of Biochemistry and Molecular Biology, University of Miami School of Medicine, 528E Gautier Bldg. 1011 NW 15th Street Miami, Miami, FL, 11336, USA
| | - Daniel Adesse
- Department of Biochemistry and Molecular Biology, University of Miami School of Medicine, 528E Gautier Bldg. 1011 NW 15th Street Miami, Miami, FL, 11336, USA
- Laboratório de Biologia Estrutural, Instituto Oswaldo Cruz, Fiocruz, Rio de Janeiro, Brazil
| | - Michal Toborek
- Department of Biochemistry and Molecular Biology, University of Miami School of Medicine, 528E Gautier Bldg. 1011 NW 15th Street Miami, Miami, FL, 11336, USA.
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Zheng X, Ren B, Gao Y. Tight junction proteins related to blood-brain barrier and their regulatory signaling pathways in ischemic stroke. Biomed Pharmacother 2023; 165:115272. [PMID: 37544283 DOI: 10.1016/j.biopha.2023.115272] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Revised: 07/29/2023] [Accepted: 07/31/2023] [Indexed: 08/08/2023] Open
Abstract
Tight junctions (TJs) are crucial for intercellular connections. The abnormal expression of proteins related to TJs can result in TJ destruction, structural damage, and endothelial and epithelial cell dysfunction. These factors are associated with the occurrence and progression of several diseases. Studies have shown that blood-brain barrier (BBB) damage and dysfunction are the prominent pathological features of stroke. TJs are directly associated with the BBB integrity. In this article, we first discuss the structure and function of BBB TJ-related proteins before focusing on the crucial events that cause TJ dysfunction and BBB damage, as well as the regulatory mechanisms that affect the qualitative and quantitative expression of TJ proteins during ischemic stroke. Multiple regulatory mechanisms, including phosphorylation, matrix metalloproteinases (MMPs), and microRNAs, regulate TJ-related proteins and affect BBB permeability. Some signaling pathways and mechanisms have been demonstrated to have dual functions. Hopefully, our understanding of the regulation of BBB TJs in ischemic stroke will be applied to the development of targeted medications and therapeutic therapies.
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Affiliation(s)
- Xiangyi Zheng
- Dongzhimen Hospital, Beijing University of Chinese Medicine, Beijing, China
| | - Beida Ren
- Dongzhimen Hospital, Beijing University of Chinese Medicine, Beijing, China; Institute for Brain Disorders, Beijing University of Chinese Medicine, Beijing, China.
| | - Ying Gao
- Dongzhimen Hospital, Beijing University of Chinese Medicine, Beijing, China; Institute for Brain Disorders, Beijing University of Chinese Medicine, Beijing, China.
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7
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Hu X, Wang Y, Du W, Liang LJ, Wang W, Jin X. Role of Glial Cell-Derived Oxidative Stress in Blood-Brain Barrier Damage after Acute Ischemic Stroke. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2022; 2022:7762078. [PMID: 36092167 PMCID: PMC9463007 DOI: 10.1155/2022/7762078] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/10/2022] [Accepted: 08/13/2022] [Indexed: 11/18/2022]
Abstract
The integrity of the blood-brain barrier (BBB) is mainly maintained by endothelial cells and basement membrane and could be regulated by pericytes, neurons, and glial cells including astrocytes, microglia, oligodendrocytes (OLs), and oligodendrocyte progenitor cells (OPCs). BBB damage is the main pathological basis of hemorrhage transformation (HT) and vasogenic edema after stroke. In addition, BBB damage-induced HT and vasogenic edema will aggravate the secondary brain tissue damage. Of note, after reperfusion, oxidative stress-initiated cascade plays a critical role in the BBB damage after acute ischemic stroke (AIS). Although endothelial cells are the target of oxidative stress, the role of glial cell-derived oxidative stress in BBB damage after AIS also should receive more attention. In the current review, we first introduce the physiology and pathophysiology of the BBB, then we summarize the possible mechanisms related to BBB damage after AIS. We aim to characterize the role of glial cell-derived oxidative stress in BBB damage after AIS and discuss the role of oxidative stress in astrocytes, microglia cells and oligodendrocytes in after AIS, respectively.
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Affiliation(s)
- Xiaoyan Hu
- Beijing Key Laboratory of Cancer Invasion and Metastasis Research, Department of Histology and Embryology, School of Basic Medical Sciences, Advanced Innovation Center for Human Brain Protection, Capital Medical University, Beijing 100069, China
| | - Yanping Wang
- Department of Neurology, The Second Hospital of Jiaxing City, Jiaxing, 314000 Zhejiang, China
| | - Weihong Du
- Beijing Key Laboratory of Cancer Invasion and Metastasis Research, Department of Histology and Embryology, School of Basic Medical Sciences, Advanced Innovation Center for Human Brain Protection, Capital Medical University, Beijing 100069, China
| | - Li-Jun Liang
- Children's Hospital of Shanxi Province, Taiyuan, Shanxi Province, China
| | - Wei Wang
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Capital Medical University, Beijing 100069, China
| | - Xinchun Jin
- Beijing Key Laboratory of Cancer Invasion and Metastasis Research, Department of Histology and Embryology, School of Basic Medical Sciences, Advanced Innovation Center for Human Brain Protection, Capital Medical University, Beijing 100069, China
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8
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Chen S, Zhang J, Li M, Zhou J, Zhang Y. Danhong injection combined with tPA protects the BBB through Notch-VEGF signaling pathway on long-term outcomes of thrombolytic therapy. Biomed Pharmacother 2022; 153:113288. [PMID: 35717787 DOI: 10.1016/j.biopha.2022.113288] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Revised: 06/08/2022] [Accepted: 06/09/2022] [Indexed: 11/17/2022] Open
Abstract
Current therapy for ischemic stroke primarily relies on tissue plasminogen activator (tPA), but it is limited by narrow treatment time window, bleeding complications and neurotoxicity. The preliminary study of tPA plus Danhong injection (DHI) shows that it can significantly reduce the side effects of tPA and improve its thrombolytic effect, but the mechanism of this action has not been further studied. In this study, the rats were randomly divided into sham group, vehicle group, DHI group (4 mL/kg), tPA group (5 mg/kg) and DHI+tPA group (4 mL/kg+ 2.5 mg/kg), administered intravenously 4.5 h since focal embolic stroke modeling. After 3 days and 7 days of cerebral ischemia, the neurological function of each treatment group was significantly improved compared with the vehicle group. The combination of DHI and tPA significantly reduced Evans blue (EB) penetration as well as the expressions of the proteins MMP-9, PAI-1 and P-selectin, while upregulating the expressions of claudin-5, occludin, and ZO-1 mRNA. Furthermore, the effect of continuous 7-day treatment was more conspicuous than 3-day treatment. Then, it significantly reduced the expressions of the proteins DLL-4 and VEGFR-2, increased the expressions of Notch-1, HIF-1α and HES-1 mRNA, and promoted the expressions of VEGF/HIF-1α-positive cells at 14 days following stroke. Hematoxylin-eosin (HE) staining and transmission electron microscopy (TEM) also showed that it improved pathological changes of ischemic brain tissue and the cerebral cortex micro-structure. These indicate that DHI combined with tPA may significantly ameliorate blood-brain barrier (BBB) disruption by activating Notch-VEGF signaling pathway to promote angiogenesis for long-term outcomes.
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Affiliation(s)
- Simiao Chen
- College of Life Science, Zhejiang Chinese Medical University, 548 Binwen Road, Binjiang District, Hangzhou 310053, China.
| | - Jinghui Zhang
- College of Life Science, Zhejiang Chinese Medical University, 548 Binwen Road, Binjiang District, Hangzhou 310053, China.
| | - Min Li
- College of Life Science, Zhejiang Chinese Medical University, 548 Binwen Road, Binjiang District, Hangzhou 310053, China.
| | - Jing Zhou
- College of Life Science, Zhejiang Chinese Medical University, 548 Binwen Road, Binjiang District, Hangzhou 310053, China.
| | - Yuyan Zhang
- College of Life Science, Zhejiang Chinese Medical University, 548 Binwen Road, Binjiang District, Hangzhou 310053, China.
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Schreiner TG, Romanescu C, Popescu BO. The Blood-Brain Barrier-A Key Player in Multiple Sclerosis Disease Mechanisms. Biomolecules 2022; 12:538. [PMID: 35454127 PMCID: PMC9025898 DOI: 10.3390/biom12040538] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Revised: 03/28/2022] [Accepted: 03/30/2022] [Indexed: 02/07/2023] Open
Abstract
Over the past decade, multiple sclerosis (MS), a chronic neuroinflammatory disease with severe personal and social consequences, has undergone a steady increase in incidence and prevalence rates worldwide. Despite ongoing research and the development of several novel therapies, MS pathology remains incompletely understood, and the prospect for a curative treatment continues to be unpromising in the near future. A sustained research effort, however, should contribute to a deeper understanding of underlying disease mechanisms, which will undoubtedly yield improved results in drug development. In recent years, the blood-brain barrier (BBB) has increasingly become the focus of many studies as it appears to be involved in both MS disease onset and progression. More specifically, neurovascular unit damage is believed to be involved in the critical process of CNS immune cell penetration, which subsequently favors the development of a CNS-specific immune response, leading to the classical pathological and clinical hallmarks of MS. The aim of the current narrative review is to merge the relevant evidence on the role of the BBB in MS pathology in a comprehensive and succinct manner. Firstly, the physiological structure and functions of the BBB as a component of the more complex neurovascular unit are presented. Subsequently, the authors review the specific alteration of the BBB encountered in different stages of MS, focusing on both the modifications of BBB cells in neuroinflammation and the CNS penetration of immune cells. Finally, the currently accepted theories on neurodegeneration in MS are summarized.
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Affiliation(s)
- Thomas Gabriel Schreiner
- Faculty of Medicine, “Carol Davila” University of Medicine and Pharmacy, 050474 Bucharest, Romania;
- Faculty of Medicine, “Gr. T. Popa” University of Medicine and Pharmacy, 700115 Iași, Romania
- Department of Electrical Measurements and Materials, Faculty of Electrical Engineering and Information Technology, Gheorghe Asachi Technical University of Iasi, 21-23 Professor Dimitrie Mangeron Blvd., 700050 Iasi, Romania
| | - Constantin Romanescu
- Faculty of Medicine, “Gr. T. Popa” University of Medicine and Pharmacy, 700115 Iași, Romania
- Clinical Section IV, “St. Parascheva” Infectious Disease Hospital, 700116 Iași, Romania
| | - Bogdan Ovidiu Popescu
- Faculty of Medicine, “Carol Davila” University of Medicine and Pharmacy, 050474 Bucharest, Romania;
- Neurology Department, Colentina Clinical Hospital, 020125 Bucharest, Romania
- Laboratory of Cell Biology, Neurosciences and Experimental Myology, “Victor Babes” National Institute of Pathology, 050096 Bucharest, Romania
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10
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Shen XY, Gao ZK, Han Y, Yuan M, Guo YS, Bi X. Activation and Role of Astrocytes in Ischemic Stroke. Front Cell Neurosci 2021; 15:755955. [PMID: 34867201 PMCID: PMC8635513 DOI: 10.3389/fncel.2021.755955] [Citation(s) in RCA: 66] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Accepted: 10/22/2021] [Indexed: 12/21/2022] Open
Abstract
Ischemic stroke refers to the disorder of blood supply of local brain tissue caused by various reasons. It has high morbidity and mortality worldwide. Astrocytes are the most abundant glial cells in the central nervous system (CNS). They are responsible for the homeostasis, nutrition, and protection of the CNS and play an essential role in many nervous system diseases’ physiological and pathological processes. After stroke injury, astrocytes are activated and play a protective role through the heterogeneous and gradual changes of their gene expression, morphology, proliferation, and function, that is, reactive astrocytes. However, the position of reactive astrocytes has always been a controversial topic. Many studies have shown that reactive astrocytes are a double-edged sword with both beneficial and harmful effects. It is worth noting that their different spatial and temporal expression determines astrocytes’ various functions. Here, we comprehensively review the different roles and mechanisms of astrocytes after ischemic stroke. In addition, the intracellular mechanism of astrocyte activation has also been involved. More importantly, due to the complex cascade reaction and action mechanism after ischemic stroke, the role of astrocytes is still difficult to define. Still, there is no doubt that astrocytes are one of the critical factors mediating the deterioration or improvement of ischemic stroke.
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Affiliation(s)
- Xin-Ya Shen
- Graduate School of Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Zhen-Kun Gao
- Graduate School of Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Yu Han
- Department of Sport Rehabilitation, Shanghai University of Sport, Shanghai, China
| | - Mei Yuan
- Department of Sport Rehabilitation, Shanghai University of Sport, Shanghai, China
| | - Yi-Sha Guo
- Department of Sport Rehabilitation, Shanghai University of Sport, Shanghai, China
| | - Xia Bi
- Department of Rehabilitation Medicine, Shanghai University of Medicine and Health Sciences Affiliated Zhoupu Hospital, Shanghai, China
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11
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Mei W, Zhu B, Shu Y, Liang Y, Lin M, He M, Luo H, Ye J. GDF11 protects against glucotoxicity-induced mice retinal microvascular endothelial cell dysfunction and diabetic retinopathy disease. Mol Cell Endocrinol 2021; 537:111422. [PMID: 34391845 DOI: 10.1016/j.mce.2021.111422] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Revised: 08/08/2021] [Accepted: 08/10/2021] [Indexed: 10/20/2022]
Abstract
Growth differentiation factor 11 (GDF11) has been implicated in the regulation of embryonic development and age-related dysfunction, including the regulation of retinal progenitor cells. However, little is known about the functions of GDF11 in diabetic retinopathy. In this study, we demonstrated that GDF11 treatment improved diabetes-induced retinal cell death, capillary degeneration, pericyte loss, inflammation, and blood-retinal barrier breakdown in mice. Treatment of isolated mouse retinal microvascular endothelial cells with recombinant GDF11 in vitro attenuated glucotoxicity-induced retinal endothelial apoptosis and the inflammatory response. The protective mechanisms exerted are associated with TGF-β/Smad2, PI3k-Akt-FoxO1 activation,and NF-κB pathway inhibition. This study indicated that GDF11 is a novel therapeutic target for diabetic retinopathy.
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Affiliation(s)
- Wen Mei
- Department of Endocrinology, Nanhai District People's Hospital of Foshan, Foping Road 40, Foshan, 528200, Guangdong Province, China; Department of Endocrinology, Wuhan Fourth Hospital, Puai Hospital, Tongji Medical College, Huazhong University of Science and Technology, Hanzheng Road 473, Wuhan, 430070, Hubei Province, China
| | - Biao Zhu
- Department of Stomatology, Fuxing Hospital, Capital Medical University, Fuxingmen Wai Street A 20, Beijing, 100038, China
| | - Yi Shu
- Department of Endocrinology, Nanhai District People's Hospital of Foshan, Foping Road 40, Foshan, 528200, Guangdong Province, China
| | - Yanhua Liang
- Department of Ophthalmology, People's Hospital of Jiangmen, Penglai Road 19, Jiangmen, 529000, Guangdong Province, China
| | - Mei Lin
- Department of Endocrinology, Wuhan Fourth Hospital, Puai Hospital, Tongji Medical College, Huazhong University of Science and Technology, Hanzheng Road 473, Wuhan, 430070, Hubei Province, China.
| | - Mingjuan He
- Department of Endocrinology, Wuhan Fourth Hospital, Puai Hospital, Tongji Medical College, Huazhong University of Science and Technology, Hanzheng Road 473, Wuhan, 430070, Hubei Province, China
| | - Haizhao Luo
- Department of Endocrinology, Nanhai District People's Hospital of Foshan, Foping Road 40, Foshan, 528200, Guangdong Province, China
| | - Jingwen Ye
- Department of Endocrinology, Nanhai District People's Hospital of Foshan, Foping Road 40, Foshan, 528200, Guangdong Province, China
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12
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Venkat P, Ning R, Zacharek A, Culmone L, Liang L, Landschoot-Ward J, Chopp M. Treatment with an Angiopoietin-1 mimetic peptide promotes neurological recovery after stroke in diabetic rats. CNS Neurosci Ther 2020; 27:48-59. [PMID: 33346402 PMCID: PMC7804913 DOI: 10.1111/cns.13541] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Revised: 11/23/2020] [Accepted: 11/24/2020] [Indexed: 12/11/2022] Open
Abstract
Aim Vasculotide (VT), an angiopoietin‐1 mimetic peptide, exerts neuroprotective effects in type one diabetic (T1DM) rats subjected to ischemic stroke. In this study, we investigated whether delayed VT treatment improves long‐term neurological outcome after stroke in T1DM rats. Methods Male Wistar rats were induced with T1DM, subjected to middle cerebral artery occlusion (MCAo) model of stroke, and treated with PBS (control), 2 µg/kg VT, 3 µg/kg VT, or 5.5 µg/kg VT. VT treatment was initiated at 24 h after stroke and administered daily (i.p) for 14 days. We evaluated neurological function, lesion volume, vascular and white matter remodeling, and inflammation in the ischemic brain. In vitro, we evaluated the effects of VT on endothelial cell capillary tube formation and inflammatory responses of primary cortical neurons (PCN) and macrophages. Results Treatment of T1DM‐stroke with 3 µg/kg VT but not 2 µg/kg or 5.5 µg/kg significantly improves neurological function and decreases infarct volume and cell death compared to control T1DM‐stroke rats. Thus, 3 µg/kg VT dose was employed in all subsequent in vivo analysis. VT treatment significantly increases axon and myelin density, decreases demyelination, decreases white matter injury, increases number of oligodendrocytes, and increases vascular density in the ischemic border zone of T1DM stroke rats. VT treatment significantly decreases MMP9 expression and decreases the number of M1 macrophages in the ischemic brain of T1DM‐stroke rats. In vitro, VT treatment significantly decreases endothelial cell death and decreases MCP‐1, endothelin‐1, and VEGF expression under high glucose (HG) and ischemic conditions and significantly increases capillary tube formation under HG conditions when compared to non‐treated control group. VT treatment significantly decreases inflammatory factor expression such as MMP9 and MCP‐1 in macrophages subjected to LPS activation and significantly decreases IL‐1β and MMP9 expression in PCN subjected to ischemia under HG conditions. Conclusion Delayed VT treatment (24 h after stroke) significantly improves neurological function, promotes vascular and white matter remodeling, and decreases inflammation in the ischemic brain after stroke in T1DM rats.
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Affiliation(s)
- Poornima Venkat
- Department of Neurology, Henry Ford Hospital, Detroit, Michigan, USA
| | - Ruizhuo Ning
- Department of Neurology, Henry Ford Hospital, Detroit, Michigan, USA
| | - Alex Zacharek
- Department of Neurology, Henry Ford Hospital, Detroit, Michigan, USA
| | - Lauren Culmone
- Department of Neurology, Henry Ford Hospital, Detroit, Michigan, USA
| | - Linlin Liang
- Department of Neurology, Henry Ford Hospital, Detroit, Michigan, USA
| | | | - Michael Chopp
- Department of Neurology, Henry Ford Hospital, Detroit, Michigan, USA.,Department of Physics, Oakland University, Rochester, Michigan, USA
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13
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Lochhead JJ, Yang J, Ronaldson PT, Davis TP. Structure, Function, and Regulation of the Blood-Brain Barrier Tight Junction in Central Nervous System Disorders. Front Physiol 2020; 11:914. [PMID: 32848858 PMCID: PMC7424030 DOI: 10.3389/fphys.2020.00914] [Citation(s) in RCA: 179] [Impact Index Per Article: 44.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2020] [Accepted: 07/08/2020] [Indexed: 12/16/2022] Open
Abstract
The blood-brain barrier (BBB) allows the brain to selectively import nutrients and energy critical to neuronal function while simultaneously excluding neurotoxic substances from the peripheral circulation. In contrast to the highly permeable vasculature present in most organs that reside outside of the central nervous system (CNS), the BBB exhibits a high transendothelial electrical resistance (TEER) along with a low rate of transcytosis and greatly restricted paracellular permeability. The property of low paracellular permeability is controlled by tight junction (TJ) protein complexes that seal the paracellular route between apposing brain microvascular endothelial cells. Although tight junction protein complexes are principal contributors to physical barrier properties, they are not static in nature. Rather, tight junction protein complexes are highly dynamic structures, where expression and/or localization of individual constituent proteins can be modified in response to pathophysiological stressors. These stressors induce modifications to tight junction protein complexes that involve de novo synthesis of new protein or discrete trafficking mechanisms. Such responsiveness of BBB tight junctions to diseases indicates that these protein complexes are critical for maintenance of CNS homeostasis. In fulfillment of this vital role, BBB tight junctions are also a major obstacle to therapeutic drug delivery to the brain. There is an opportunity to overcome this substantial obstacle and optimize neuropharmacology via acquisition of a detailed understanding of BBB tight junction structure, function, and regulation. In this review, we discuss physiological characteristics of tight junction protein complexes and how these properties regulate delivery of therapeutics to the CNS for treatment of neurological diseases. Specifically, we will discuss modulation of tight junction structure, function, and regulation both in the context of disease states and in the setting of pharmacotherapy. In particular, we will highlight how these properties can be potentially manipulated at the molecular level to increase CNS drug levels via paracellular transport to the brain.
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14
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Michinaga S, Tanabe A, Nakaya R, Fukutome C, Inoue A, Iwane A, Minato Y, Tujiuchi Y, Miyake D, Mizuguchi H, Koyama Y. Angiopoietin-1/Tie-2 signal after focal traumatic brain injury is potentiated by BQ788, an ET B receptor antagonist, in the mouse cerebrum: Involvement in recovery of blood-brain barrier function. J Neurochem 2020; 154:330-348. [PMID: 31957020 DOI: 10.1111/jnc.14957] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2019] [Revised: 12/12/2019] [Accepted: 01/08/2020] [Indexed: 01/05/2023]
Abstract
Angiopoietin-1, an angiogenic factor, stabilizes brain microvessels through Tie-2 receptor tyrosine kinase. In traumatic brain injury, blood-brain barrier (BBB) disruption is an aggravating factor that induces brain edema and neuroinflammation. We previously showed that BQ788, an endothelin ETB receptor antagonist, promoted recovery of BBB function after lateral fluid percussion injury (FPI) in mice. To clarify the mechanisms underlying BBB recovery mediated by BQ788, we examined the involvements of the angiopoietin-1/Tie-2 signal. When angiopoietin-1 production and Tie-2 phosphorylation were assayed by quantitative reverse transcription polymerase chain reaction and western blotting, increased angiopoietin-1 production and Tie-2 phosphorylation were observed in 7-10 days after FPI in the mouse cerebrum, whereas no significant effects were obtained at 5 days. When BQ788 (15 nmol/day, i.c.v.) were administered in 2-5 days after FPI, increased angiopoietin-1 production and Tie-2 phosphorylation were observed. Immunohistochemical observations showed that brain microvessels and astrocytes contained angiopoietin-1 after FPI, and brain microvessels also contained phosphorylated Tie-2. Treatment with endothelin-1 (100 nM) decreased angiopoietin-1 production in cultured astrocytes and the effect was inhibited by BQ788 (1 μM). Five days after FPI, increased extravasation of Evans blue dye accompanied by reduction in claudin-5, occludin, and zonula occludens-1 proteins were observed in mouse cerebrum while these effects of FPI were reduced by BQ788 and exogenous angiopoietin-1 (1 μg/day, i.c.v.). The effects of BQ788 were inhibited by co-administration of a Tie-2 kinase inhibitor (40 nmol/day, i.c.v.). These results suggest that BQ788 administration after traumatic brain injury promotes recovery of BBB function through activation of the angiopoietin-1/Tie-2 signal.
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Affiliation(s)
- Shotaro Michinaga
- Laboratory of Pharmacology, Faculty of Pharmacy, Osaka Ohtani University, Tondabayashi, Osaka, Japan
| | - Ayami Tanabe
- Laboratory of Pharmacology, Faculty of Pharmacy, Osaka Ohtani University, Tondabayashi, Osaka, Japan
| | - Ryusei Nakaya
- Laboratory of Pharmacology, Faculty of Pharmacy, Osaka Ohtani University, Tondabayashi, Osaka, Japan
| | - Chihiro Fukutome
- Laboratory of Pharmacology, Faculty of Pharmacy, Osaka Ohtani University, Tondabayashi, Osaka, Japan
| | - Anna Inoue
- Laboratory of Pharmacology, Faculty of Pharmacy, Osaka Ohtani University, Tondabayashi, Osaka, Japan
| | - Aya Iwane
- Laboratory of Pharmacology, Faculty of Pharmacy, Osaka Ohtani University, Tondabayashi, Osaka, Japan
| | - Yukiko Minato
- Laboratory of Pharmacology, Faculty of Pharmacy, Osaka Ohtani University, Tondabayashi, Osaka, Japan
| | - Yu Tujiuchi
- Laboratory of Pharmacology, Faculty of Pharmacy, Osaka Ohtani University, Tondabayashi, Osaka, Japan
| | - Daisuke Miyake
- Laboratory of Pharmacology, Faculty of Pharmacy, Osaka Ohtani University, Tondabayashi, Osaka, Japan
| | - Hiroyuki Mizuguchi
- Laboratory of Pharmacology, Faculty of Pharmacy, Osaka Ohtani University, Tondabayashi, Osaka, Japan
| | - Yutaka Koyama
- Laboratory of Pharmacology, Kobe Pharmaceutical University, Kobe, Japan
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15
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Moxon JV, Trollope AF, Dewdney B, de Hollander C, Nastasi DR, Maguire JM, Golledge J. The effect of angiopoietin-1 upregulation on the outcome of acute ischaemic stroke in rodent models: A meta-analysis. J Cereb Blood Flow Metab 2019; 39:2343-2354. [PMID: 31581897 PMCID: PMC6893985 DOI: 10.1177/0271678x19876876] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Clinical studies report that low circulating angiopoietin-1 concentration at presentation predicts worse outcomes after ischaemic stroke. Upregulating angiopoietin-1 may therefore have therapeutic benefit for ischaemic stroke. This systematic review assessed whether upregulating angiopoietin-1 improved outcomes in rodent models of ischaemic stroke. Random-effects models quantified the effect of angiopoietin-1 upregulation on stroke severity in terms of the size of cerebral infarction and the extent of blood-brain barrier permeability. Eleven studies utilising rat and mouse models of ischaemic stroke fulfilled the inclusion criteria. Meta-analyses demonstrated that angiopoietin-1 upregulation significantly reduced cerebral infarction size (standardised mean difference: -3.02; 95% confidence intervals: -4.41, -1.63; p < 0.001; n = 171 animals) and improved blood-brain barrier integrity (standardized mean difference: -2.02; 95% confidence intervals: -3.27, -0.77; p = 0.002; n = 129 animals). Subgroup analyses demonstrated that angiopoietin-1 upregulation improved outcomes in models of transient, not permanent cerebral ischaemia. Six studies assessed the effect of angiopoietin-1 upregulation on neurological function; however, inter-study heterogeneity prevented meta-analysis. In conclusion, published rodent data suggest that angiopoietin-1 upregulation improves outcome following temporary cerebral ischaemia by reducing cerebral infarction size and improving blood-brain barrier integrity. Additional research is required to examine the effect of angiopoietin-1 upregulation on neurological function during stroke recovery and investigate the benefit and risks in patients.
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Affiliation(s)
- Joseph V Moxon
- Queensland Research Centre for Peripheral Vascular Disease, James Cook University, Townsville, Australia.,The Australian Institute of Tropical Health and Medicine, James Cook University, Townsville, Australia
| | - Alexandra F Trollope
- Queensland Research Centre for Peripheral Vascular Disease, James Cook University, Townsville, Australia.,The Australian Institute of Tropical Health and Medicine, James Cook University, Townsville, Australia.,Department of Anatomy, James Cook University, Townsville, Australia
| | - Brittany Dewdney
- Queensland Research Centre for Peripheral Vascular Disease, James Cook University, Townsville, Australia.,Faculty of Health, University of Technology Sydney, Sydney, Australia
| | | | - Domenico R Nastasi
- Queensland Research Centre for Peripheral Vascular Disease, James Cook University, Townsville, Australia
| | - Jane M Maguire
- Faculty of Health, University of Technology Sydney, Sydney, Australia
| | - Jonathan Golledge
- Queensland Research Centre for Peripheral Vascular Disease, James Cook University, Townsville, Australia.,The Australian Institute of Tropical Health and Medicine, James Cook University, Townsville, Australia.,Department of Vascular and Endovascular Surgery, The Townsville Hospital, Townsville, Australia
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16
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Yu Y, Fang H, Qiu Z, Xia Z, Zhou B. DHA Attenuates Hypoxia/Reoxygenation Injury by Activating SSeCKS in Human Cerebrovascular Pericytes. Neurochem Res 2019; 45:310-321. [PMID: 31776970 PMCID: PMC6985071 DOI: 10.1007/s11064-019-02915-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2019] [Revised: 11/07/2019] [Accepted: 11/18/2019] [Indexed: 12/11/2022]
Abstract
Docosahexaenoic acid (DHA) can alleviate cerebral ischemia/reperfusion injury by reducing blood–brain barrier permeability and maintaining its integrity, accompanied by an increased Ang-1/Ang-2 ratio; however, the underlying mechanisms of these effects remain unclear. Src-suppressed C kinase substrates (SSeCKS), a substrate of protein kinase C, plays an important role in maintaining cell junctions and cell morphology and regulating cell permeability. However, whether DHA can increase SSeCKS expression and then mediate the Ang-1/Ang-2 ratio still needs to be studied. Human cerebrovascular pericytes (HBVPs) cultured in vitro were divided into groups, treated with or without DHA along with SSeCKS siRNA to knockdown SSeCKS expression, and then subjected to 24 h of hypoxia followed by 6 h of reoxygenation. Cell viability; lactate dehydrogenase (LDH) release; and Ang-1, Ang-2 and VEGF activity were detected by using ELISA kits. The apoptosis rate was assessed by TUNEL flow cytometry. Expression of the SSeCKS, Ang-1, Ang-2 and VEGF proteins was evaluated by western blotting. Pretreatment with 10 μM or 40 μM DHA efficiently attenuated hypoxia/reoxygenation (H/R) injury by activating SSeCKS to increase the Ang-1/Ang-2 ratio and downregulate VEGF expression in HBVPs, as evidenced by decreased LDH release and apoptotic rates and increased HBVPs viability. Meanwhile, after we used SSeCKS siRNA to knock down SSeCKS protein expression, the protective effect of DHA on HBVPs following H/R injury was reversed. In conclusion, DHA can activate SSeCKS to increase the Ang-1/Ang-2 ratio and downregulate VEGF expression in HBVPs, thus reducing H/R injury.
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Affiliation(s)
- Yanli Yu
- Department of Anesthesiology, Renmin Hospital of Wuhan University, Wuhan, 430060, Hubei, China
| | - Haibin Fang
- Department of Anesthesiology, Renmin Hospital of Wuhan University, Wuhan, 430060, Hubei, China
| | - Zhen Qiu
- Department of Anesthesiology, Renmin Hospital of Wuhan University, Wuhan, 430060, Hubei, China
| | - Zhongyuan Xia
- Department of Anesthesiology, Renmin Hospital of Wuhan University, Wuhan, 430060, Hubei, China
| | - Bin Zhou
- Department of Anesthesiology, Renmin Hospital of Wuhan University, Wuhan, 430060, Hubei, China.
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17
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Cong X, Kong W. Endothelial tight junctions and their regulatory signaling pathways in vascular homeostasis and disease. Cell Signal 2019; 66:109485. [PMID: 31770579 DOI: 10.1016/j.cellsig.2019.109485] [Citation(s) in RCA: 132] [Impact Index Per Article: 26.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2019] [Revised: 11/21/2019] [Accepted: 11/21/2019] [Indexed: 12/13/2022]
Abstract
Endothelial tight junctions (TJs) regulate the transport of water, ions, and molecules through the paracellular pathway, serving as an important barrier in blood vessels and maintaining vascular homeostasis. In endothelial cells (ECs), TJs are highly dynamic structures that respond to multiple external stimuli and pathological conditions. Alterations in the expression, distribution, and structure of endothelial TJs may lead to many related vascular diseases and pathologies. In this review, we provide an overview of the assessment methods used to evaluate endothelial TJ barrier function both in vitro and in vivo and describe the composition of endothelial TJs in diverse vascular systems and ECs. More importantly, the direct phosphorylation and dephosphorylation of TJ proteins by intracellular kinases and phosphatases, as well as the signaling pathways involved in the regulation of TJs, including and the protein kinase C (PKC), PKA, PKG, Ras homolog gene family member A (RhoA), mitogen-activated protein kinase (MAPK), phosphatidylinositol 3-kinase (PI3K)/Akt, and Wnt/β-catenin pathways, are discussed. With great advances in this area, targeting endothelial TJs may provide novel treatment for TJ-related vascular pathologies.
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Affiliation(s)
- Xin Cong
- Department of Physiology and Pathophysiology, Peking University School of Basic Medical Sciences, Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education, Beijing Key Laboratory of Cardiovascular Receptors Research, Beijing 100191, China.
| | - Wei Kong
- Department of Physiology and Pathophysiology, Peking University School of Basic Medical Sciences, Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education, Beijing Key Laboratory of Cardiovascular Receptors Research, Beijing 100191, China.
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18
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Kunze R, Marti HH. Angioneurins - Key regulators of blood-brain barrier integrity during hypoxic and ischemic brain injury. Prog Neurobiol 2019; 178:101611. [PMID: 30970273 DOI: 10.1016/j.pneurobio.2019.03.004] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Accepted: 03/29/2019] [Indexed: 12/14/2022]
Abstract
The loss of blood-brain barrier (BBB) integrity leading to vasogenic edema and brain swelling is a common feature of hypoxic/ischemic brain diseases such as stroke, but is also central to the etiology of other CNS disorders. In the past decades, numerous proteins, belonging to the family of angioneurins, have gained increasing attention as potential therapeutic targets for ischemic stroke, but also other CNS diseases attributed to BBB dysfunction. Angioneurins encompass mediators that affect both neuronal and vascular function. Recently, increasing evidence has been accumulated that certain angioneurins critically determine disease progression and outcome in stroke among others through multifaceted effects on the compromised BBB. Here, we will give a concise overview about the family of angioneurins. We further describe the most important cellular and molecular components that contribute to structural integrity and low permeability of the BBB under steady-state conditions. We then discuss BBB alterations in ischemic stroke, and highlight underlying cellular and molecular mechanisms. For the most prominent angioneurin family members including vascular endothelial growth factors, angiopoietins, platelet-derived growth factors and erythropoietin, we will summarize current scientific literature from experimental studies in animal models, and if available from clinical trials, on the following points: (i) spatiotemporal expression of these factors in the healthy and hypoxic/ischemic CNS, (ii) impact of loss- or gain-of-function during cerebral hypoxia/ischemia for BBB integrity and beyond, and (iii) potential underlying molecular mechanisms. Moreover, we will highlight novel therapeutic strategies based on the activation of endogenous angioneurins that might improve BBB dysfuntion during ischemic stroke.
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Affiliation(s)
- Reiner Kunze
- Institute of Physiology and Pathophysiology, Heidelberg University, Germany.
| | - Hugo H Marti
- Institute of Physiology and Pathophysiology, Heidelberg University, Germany
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19
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Dual Roles of Astrocyte-Derived Factors in Regulation of Blood-Brain Barrier Function after Brain Damage. Int J Mol Sci 2019; 20:ijms20030571. [PMID: 30699952 PMCID: PMC6387062 DOI: 10.3390/ijms20030571] [Citation(s) in RCA: 156] [Impact Index Per Article: 31.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2018] [Revised: 01/23/2019] [Accepted: 01/27/2019] [Indexed: 12/13/2022] Open
Abstract
The blood-brain barrier (BBB) is a major functional barrier in the central nervous system (CNS), and inhibits the extravasation of intravascular contents and transports various essential nutrients between the blood and the brain. After brain damage by traumatic brain injury, cerebral ischemia and several other CNS disorders, the functions of the BBB are disrupted, resulting in severe secondary damage including brain edema and inflammatory injury. Therefore, BBB protection and recovery are considered novel therapeutic strategies for reducing brain damage. Emerging evidence suggests key roles of astrocyte-derived factors in BBB disruption and recovery after brain damage. The astrocyte-derived vascular permeability factors include vascular endothelial growth factors, matrix metalloproteinases, nitric oxide, glutamate and endothelin-1, which enhance BBB permeability leading to BBB disruption. By contrast, the astrocyte-derived protective factors include angiopoietin-1, sonic hedgehog, glial-derived neurotrophic factor, retinoic acid and insulin-like growth factor-1 and apolipoprotein E which attenuate BBB permeability resulting in recovery of BBB function. In this review, the roles of these astrocyte-derived factors in BBB function are summarized, and their significance as therapeutic targets for BBB protection and recovery after brain damage are discussed.
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20
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Angiopoietin-1 Promotes the Integrity of Neovascularization in the Subcutaneous Matrigel of Type 1 Diabetic Rats. BIOMED RESEARCH INTERNATIONAL 2019; 2019:2016972. [PMID: 30729120 PMCID: PMC6343146 DOI: 10.1155/2019/2016972] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/03/2018] [Accepted: 12/30/2018] [Indexed: 12/21/2022]
Abstract
Objective This study aimed to investigate the effects of Ang-1 on neovascularization of diabetic organs by subcutaneous Matrigel angiogenesis model, established in type 1 diabetic rats. Methods Ang-1 adenoviral vector was constructed. The rat model was established by STZ and divided into four group. The Matrigel was inserted subcutaneously into the abdominal cavity of rats at 8 weeks, the treatment group was injected with Ang-1 adenovirus vector via tail vein, and the rats were sacrificed at 10 weeks. Neovascularization of Matrigel was observed with transmission electron microscopy. The marker of vascular endothelial cell and pericyte were detected by immunofluorescence. Immunohistochemical detection of the neovascular endothelial junction protein was performed. RT-PCR was used to determine protein expression of neovascular in Matrigel. Results Vascular cavity-like structure could be seen in subcutaneous Matrigel of diabetic rats, and the cavity was filled with a lot of red blood cells. Transmission electron microscopy showed that neovascular endothelial structure of the Matrigel was incomplete, while the Ang-1 treatment group had more vascular cavity-like structures, intact vascular endothelial structure, and reduced inflammatory cell infiltration in Matrigel. Additionally, the integrity of vascularization improved, and the marker of pericyte and the cell tight junctions protein was upregulated in Ang-1 treatment group. Conclusion Hyperglycemia could induce pathological angiogenesis in subcutaneous Matrigel of diabetic rats, and Ang-1 could upregulate the expression of intercellular junction protein in subcutaneous Matrigel of diabetic rats and promote the integrity of neovascularization in the subcutaneous Matrigel of diabetic rats.
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21
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Xie H, Lu WC. Inhibition of transient receptor potential vanilloid 4 decreases the expressions of caveolin-1 and caveolin-2 after focal cerebral ischemia and reperfusion in rats. Neuropathology 2018; 38:337-346. [PMID: 29665111 DOI: 10.1111/neup.12469] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2018] [Revised: 02/20/2018] [Accepted: 03/18/2018] [Indexed: 01/26/2023]
Abstract
This study aimed to investigate the effects of transient receptor potential vanilloid 4 (TRPV4) inhibition on blood-brain barrier (BBB) integrity and the expressions of caveolae structural proteins caveolin-1 and caveolin-2 in rats with focal cerebral ischemia and reperfusion. BBB permeability was assessed by Evans blue extravasation. The mRNA and protein expressions of caveolin-1 and caveolin-2 were determined by RT-PCR, Western blot and immunohistochemistry assays. We found that BBB permeability significantly increased and reaches its peak at 72 h of reperfusion in cerebral ischemia-reperfusion rats and is able to be ameliorated by administration of HC-067047, an antagonist of TRPV4. Additionally, it shows a significant upregulation of caveolin-1 and caveolin-2 expression in cerebral microvessels of ischemic tissue. However, treatment with HC-067047 was shown to downregulate caveolin-1 and caveolin-2 expression during cerebral ischemia-reperfusion. This study demonstrates that inhibition of TRPV4 ameliorates BBB leakage induced by ischemia-reperfusion injury through the downregulation of caveolin-1 and caveolin-2.
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Affiliation(s)
- Hui Xie
- Department of Histology and Embryology, College of Basic Medicine, Shenyang Medical College, Shenyang, China
| | - Wei-Cheng Lu
- Department of Neurosurgery, First Affiliated Hospital of China Medical University, Shenyang, China
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22
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S-Nitrosoglutathione Reductase Deficiency Confers Improved Survival and Neurological Outcome in Experimental Cerebral Malaria. Infect Immun 2017; 85:IAI.00371-17. [PMID: 28674030 DOI: 10.1128/iai.00371-17] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2017] [Accepted: 06/26/2017] [Indexed: 11/20/2022] Open
Abstract
Artesunate remains the mainstay of treatment for cerebral malaria, but it is less effective in later stages of disease when the host inflammatory response and blood-brain barrier integrity dictate clinical outcomes. Nitric oxide (NO) is an important regulator of inflammation and microvascular integrity, and impaired NO bioactivity is associated with fatal outcomes in malaria. Endogenous NO bioactivity in mammals is largely mediated by S-nitrosothiols (SNOs). Based on these observations, we hypothesized that animals deficient in the SNO-metabolizing enzyme, S-nitrosoglutathione reductase (GSNOR), which exhibit enhanced S-nitrosylation, would have improved outcomes in a preclinical model of cerebral malaria. GSNOR knockout (KO) mice infected with Plasmodium berghei ANKA had significantly delayed mortality compared to WT animals (P < 0.0001), despite higher parasite burdens (P < 0.01), and displayed markedly enhanced survival versus the wild type (WT) when treated with the antimalarial drug artesunate (77% versus 38%; P < 0.001). Improved survival was associated with higher levels of protein-bound NO, decreased levels of CD4+ and CD8+ T cells in the brain, improved blood-brain barrier integrity, and improved coma scores, as well as higher levels of gamma interferon. GSNOR KO animals receiving WT bone marrow had significantly reduced survival following P. berghei ANKA infection compared to those receiving KO bone barrow (P < 0.001). Reciprocal transplants established that survival benefits of GSNOR deletion were attributable primarily to the T cell compartment. These data indicate a role for GSNOR in the host response to malaria infection and suggest that strategies to disrupt its activity will improve clinical outcomes by enhancing microvascular integrity and modulating T cell tissue tropism.
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23
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Gao H, Chen P, Wei L, Xu J, Liu L, Zhao Y, Hara H, Pan D, Li Z, Cooper DKC, Cai Z, Mou L. Angiopoietin-1 and angiopoietin-2 protect porcine iliac endothelial cells from human antibody-mediated complement-dependent cytotoxicity through phosphatidylinositide 3-kinase/AKT pathway activation. Xenotransplantation 2017; 24. [PMID: 28474373 DOI: 10.1111/xen.12309] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2016] [Revised: 03/16/2017] [Accepted: 03/27/2017] [Indexed: 01/06/2023]
Abstract
Cytokines play crucial roles in inflammation, but their role in xenotransplantation remains elusive. We assessed the role of several cytokines using an in vitro model of human antibody-mediated complement-dependent cytotoxicity (CDC). Recombinant human angiopoietin-1 (Ang-1) protected porcine iliac endothelial cells (PIECs) from human antibody-mediated CDC. Interestingly, human angiopoietin-2 (Ang-2) had a similar protective effect on PIECs. By flow cytometry analysis, the extent of human IgM and IgG binding to PIECs did not decrease when PIECs were exposed to Ang-1/Ang-2. The mRNA level of complement regulators (CD46, CD55, CD59) was not upregulated in PIECs treated with Ang-1/Ang-2, both of which activated the PI3K/AKT pathway in PIECs. Wortmannin, which inhibits phosphatidylinositide 3-kinase (PI3K), suppressed Ang-1/Ang-2-induced AKT phosphorylation and consequent Ang-1/Ang-2-mediated protection of PIECs in human antibody-mediated CDC model. Moreover, dominant negative AKT also suppressed Ang-1/Ang-2-mediated protection of PIECs in this model. In conclusion, our data suggest that human Ang-1/Ang-2 induces the protection of PIECs from human antibody-mediated CDC by activating the PI3K/AKT pathway. Ang-1/Ang-2 is likely to protect porcine endothelial cells and may be beneficial in xenotransplantation research.
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Affiliation(s)
- Hanchao Gao
- Shenzhen Xenotransplantation Medical Engineering Research and Development Center, Shenzhen Second People's Hospital, First Affiliated Hospital of Shenzhen University, Shenzhen, China.,Department of Biochemistry, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
| | - Pengfei Chen
- Shenzhen Xenotransplantation Medical Engineering Research and Development Center, Shenzhen Second People's Hospital, First Affiliated Hospital of Shenzhen University, Shenzhen, China.,Department of Biochemistry, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
| | - Ling Wei
- Shenzhen Xenotransplantation Medical Engineering Research and Development Center, Shenzhen Second People's Hospital, First Affiliated Hospital of Shenzhen University, Shenzhen, China
| | - Jia Xu
- Shenzhen Xenotransplantation Medical Engineering Research and Development Center, Shenzhen Second People's Hospital, First Affiliated Hospital of Shenzhen University, Shenzhen, China
| | - Lu Liu
- Shenzhen Xenotransplantation Medical Engineering Research and Development Center, Shenzhen Second People's Hospital, First Affiliated Hospital of Shenzhen University, Shenzhen, China.,Department of Biochemistry, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
| | - Yanli Zhao
- Shenzhen Xenotransplantation Medical Engineering Research and Development Center, Shenzhen Second People's Hospital, First Affiliated Hospital of Shenzhen University, Shenzhen, China
| | - Hidetaka Hara
- Thomas E. Starzl Transplantation Institute, University of Pittsburgh, Pittsburgh, PA, USA
| | - Dengke Pan
- Key Laboratory of Farm Animal Genetic Resource and Germplasm Innovation of Ministry of Agriculture, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Zesong Li
- Shenzhen Xenotransplantation Medical Engineering Research and Development Center, Shenzhen Second People's Hospital, First Affiliated Hospital of Shenzhen University, Shenzhen, China
| | - David K C Cooper
- Thomas E. Starzl Transplantation Institute, University of Pittsburgh, Pittsburgh, PA, USA
| | - Zhiming Cai
- Shenzhen Xenotransplantation Medical Engineering Research and Development Center, Shenzhen Second People's Hospital, First Affiliated Hospital of Shenzhen University, Shenzhen, China
| | - Lisha Mou
- Shenzhen Xenotransplantation Medical Engineering Research and Development Center, Shenzhen Second People's Hospital, First Affiliated Hospital of Shenzhen University, Shenzhen, China
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Li J, Li C, Yuan W, Wu J, Li J, Li Z, Zhao Y. Mild hypothermia alleviates brain oedema and blood-brain barrier disruption by attenuating tight junction and adherens junction breakdown in a swine model of cardiopulmonary resuscitation. PLoS One 2017; 12:e0174596. [PMID: 28355299 PMCID: PMC5371345 DOI: 10.1371/journal.pone.0174596] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2016] [Accepted: 03/11/2017] [Indexed: 12/21/2022] Open
Abstract
Mild hypothermia improves survival and neurological recovery after cardiac arrest (CA) and cardiopulmonary resuscitation (CPR). However, the mechanism underlying this phenomenon is not fully elucidated. The aim of this study was to determine whether mild hypothermia alleviates early blood-brain barrier (BBB) disruption. We investigated the effects of mild hypothermia on neurologic outcome, survival rate, brain water content, BBB permeability and changes in tight junctions (TJs) and adherens junctions (AJs) after CA and CPR. Pigs were subjected to 8 min of untreated ventricular fibrillation followed by CPR. Mild hypothermia (33°C) was intravascularly induced and maintained at this temperature for 12 h, followed by active rewarming. Mild hypothermia significantly reduced cortical water content, decreased BBB permeability and attenuated TJ ultrastructural and basement membrane breakdown in brain cortical microvessels. Mild hypothermia also attenuated the CPR-induced decreases in TJ (occludin, claudin-5, ZO-1) and AJ (VE-cadherin) protein and mRNA expression. Furthermore, mild hypothermia decreased the CA- and CPR-induced increases in matrix metalloproteinase-9 (MMP-9) and vascular endothelial growth factor (VEGF) expression and increased angiogenin-1 (Ang-1) expression. Our findings suggest that mild hypothermia attenuates the CA- and resuscitation-induced early brain oedema and BBB disruption, and this improvement might be at least partially associated with attenuation of the breakdown of TJ and AJ, suppression of MMP-9 and VEGF expression, and upregulation of Ang-1 expression.
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Affiliation(s)
- Jiebin Li
- Beijing Key Laboratory of Cardiopulmonary-Cerebral Resuscitation, Department of Emergency Medicine, Beijing Chaoyang Hospital, Capital Medical University, Beijing, China
| | - Chunsheng Li
- Beijing Key Laboratory of Cardiopulmonary-Cerebral Resuscitation, Department of Emergency Medicine, Beijing Chaoyang Hospital, Capital Medical University, Beijing, China
- * E-mail:
| | - Wei Yuan
- Beijing Key Laboratory of Cardiopulmonary-Cerebral Resuscitation, Department of Emergency Medicine, Beijing Chaoyang Hospital, Capital Medical University, Beijing, China
| | - Junyuan Wu
- Beijing Key Laboratory of Cardiopulmonary-Cerebral Resuscitation, Department of Emergency Medicine, Beijing Chaoyang Hospital, Capital Medical University, Beijing, China
| | - Jie Li
- Department of Emergency Medicine, Beijing FuXing Hospital, Capital Medical University, Beijing, China
| | - Zhenhua Li
- Department of Emergency Medicine, Beijing Friendship Hospital, Capital Medical University, Beijing, China
| | - Yongzhen Zhao
- Beijing Key Laboratory of Cardiopulmonary-Cerebral Resuscitation, Department of Emergency Medicine, Beijing Chaoyang Hospital, Capital Medical University, Beijing, China
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25
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Kanazawa M, Takahashi T, Nishizawa M, Shimohata T. Therapeutic Strategies to Attenuate Hemorrhagic Transformation After Tissue Plasminogen Activator Treatment for Acute Ischemic Stroke. J Atheroscler Thromb 2017; 24:240-253. [PMID: 27980241 PMCID: PMC5383539 DOI: 10.5551/jat.rv16006] [Citation(s) in RCA: 60] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2016] [Accepted: 11/09/2016] [Indexed: 01/11/2023] Open
Abstract
This review focuses on the mechanisms and emerging concepts of stroke and therapeutic strategies for attenuating hemorrhagic transformation (HT) after tissue plasminogen activator (tPA) treatment for acute ischemic stroke (AIS). The therapeutic time window for tPA treatment has been extended. However, the patients who are eligible for tPA treatment are still <5% of all patients with AIS. The risk of serious or fatal symptomatic hemorrhage increases with delayed initiation of treatment. HT is thought to be caused by 1) ischemia/reperfusion injury; 2) the toxicity of tPA itself; 3) inflammation; and/or 4) remodeling factor-mediated effects. Modulation of these pathophysiologies is the basis of direct therapeutic strategies to attenuate HT after tPA treatment. Several studies have revealed that matrix metalloproteinases and free radicals are potential therapeutic targets. In addition, we have demonstrated that the inhibition of the vascular endothelial growth factor-signaling pathway and supplemental treatment with a recombinant angiopoietin-1 protein might be a promising therapeutic strategy for attenuating HT after tPA treatment through vascular protection. Moreover, single-target therapies could be insufficient for attenuating HT after tPA treatment and improving the therapeutic outcome of patients with AIS. We recently identified progranulin, which is a growth factor and a novel target molecule with multiple therapeutic effects. Progranulin might be a therapeutic target that protects the brain through suppression of vascular remodeling (vascular protection), neuroinflammation, and/or neuronal death (neuroprotection). Clinical trials which evaluate the effects of anti-VEGF drugs or PGRN-based treatment with tPA will be might worthwhile.
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Affiliation(s)
- Masato Kanazawa
- Department of Neurology, Brain Research Institute, Niigata University, Niigata, Japan
| | - Tetsuya Takahashi
- Department of Neurology, Brain Research Institute, Niigata University, Niigata, Japan
| | - Masatoyo Nishizawa
- Department of Neurology, Brain Research Institute, Niigata University, Niigata, Japan
| | - Takayoshi Shimohata
- Department of Neurology, Brain Research Institute, Niigata University, Niigata, Japan
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26
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Li L, Wang N, Jin Q, Wu Q, Liu Y, Wang Y. Protection of Tong-Qiao-Huo-Xue Decoction against Cerebral Ischemic Injury through Reduction Blood–Brain Barrier Permeability. Chem Pharm Bull (Tokyo) 2017; 65:1004-1010. [DOI: 10.1248/cpb.c17-00267] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
- Lili Li
- Key Laboratory of Xin’an Medicine, Ministry of Education
- Institute for Pharmacodynamics and Safety Evaluation of Chinese Medicine, Anhui Academy of Chinese Medicine
- College of Pharmacy, Anhui University of Chinese Medicine
| | - Ning Wang
- Key Laboratory of Xin’an Medicine, Ministry of Education
- Institute for Pharmacodynamics and Safety Evaluation of Chinese Medicine, Anhui Academy of Chinese Medicine
- College of Pharmacy, Anhui University of Chinese Medicine
| | - Qizhong Jin
- Key Laboratory of Xin’an Medicine, Ministry of Education
- Institute for Pharmacodynamics and Safety Evaluation of Chinese Medicine, Anhui Academy of Chinese Medicine
| | - Qian Wu
- Key Laboratory of Xin’an Medicine, Ministry of Education
- Institute for Pharmacodynamics and Safety Evaluation of Chinese Medicine, Anhui Academy of Chinese Medicine
| | - Yafang Liu
- Key Laboratory of Xin’an Medicine, Ministry of Education
- Institute for Pharmacodynamics and Safety Evaluation of Chinese Medicine, Anhui Academy of Chinese Medicine
- College of Pharmacy, Anhui University of Chinese Medicine
| | - Yan Wang
- Key Laboratory of Xin’an Medicine, Ministry of Education
- Institute for Pharmacodynamics and Safety Evaluation of Chinese Medicine, Anhui Academy of Chinese Medicine
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Chen X, Wang Q, Zhan L, Shu A. Effects and mechanisms of docosahexaenoic acid on the generation of angiopoietin-2 by rat brain microvascular endothelial cells under an oxygen- and glucose-deprivation environment. SPRINGERPLUS 2016; 5:1518. [PMID: 27652091 PMCID: PMC5017979 DOI: 10.1186/s40064-016-3067-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/23/2016] [Accepted: 08/12/2016] [Indexed: 01/06/2023]
Abstract
Objective The aim of this study was to investigate the effects of docosahexaenoic acid (DHA) on the generation of angiopoietin-2 (Ang-2) by rat brain microvascular endothelial cells under an oxygen- and glucose-deprivation environment (OGD), and its relationship, if any, with cyclooxygenase 2 (COX-2) expression. Methods Annexin V and propidium iodide apoptosis assay was used to detect apoptosis. Enzyme linked immunosorbent assay was used to detect Ang-2, vascular endothelial growth factor (VEGF), prostaglandin E2 (PGE2), and prostaglandin I2 (PGI2) content. Reverse transcription polymerase chain reaction (RT-PCR) was used to detect Ang-2 and VEGF mRNA expression. Western blot was used to detect expression of COX-2 protein. Results DHA reduced the apoptosis rate (P = 0.026) and decreased the secretion of Ang-2, VEGF, PGE2, and PGI2 (P = 0.006, P = 0.000, P = 0.002, P = 0.004 respectively). The relative expression of Ang2 and Vegf mRNA, as well as COX-2 expression, also decreased (P = 0.000, P = 0.005, P = 0.007 respectively). These effects were antagonized by GW9662 (peroxisome proliferator-activated receptor-γ antagonist). COX-2 protein expression levels were positively correlated with Ang2 and Vegf mRNA expression levels (γ = 0.69, P = 0.038 and γ = 0.76, P = 0.032, respectively). Ang-2 and VEGF mRNA levels were positively correlated with Ang-2 (γ = 0.84, P = 0.012) and VEGF (γ = 0.71, P = 0.036) secretion levels respectively. Conclusion DHA reduced apoptosis induced by an OGD environment, thus decreasing Ang-2 and VEGF synthesis. This phenomenon was associated with a decrease in COX-2 protein expression, PGE2 and PGI2 secretion, and generation regulation via intracellular transcriptional pathways.
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Affiliation(s)
- Xiaobo Chen
- Department of Anesthesiology, Three Gorges University People's Hospital, The First People's Hospital of Yichang, No. 2 Jiefang Road, Yichang, 443000 Hubei China
| | - Qiang Wang
- Department of Anesthesiology, Three Gorges University People's Hospital, The First People's Hospital of Yichang, No. 2 Jiefang Road, Yichang, 443000 Hubei China
| | - Leyun Zhan
- Department of Anesthesiology, Three Gorges University People's Hospital, The First People's Hospital of Yichang, No. 2 Jiefang Road, Yichang, 443000 Hubei China
| | - Aihua Shu
- Department of Anesthesiology, Three Gorges University People's Hospital, The First People's Hospital of Yichang, No. 2 Jiefang Road, Yichang, 443000 Hubei China
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Pan Q, He C, Liu H, Liao X, Dai B, Chen Y, Yang Y, Zhao B, Bihl J, Ma X. Microvascular endothelial cells-derived microvesicles imply in ischemic stroke by modulating astrocyte and blood brain barrier function and cerebral blood flow. Mol Brain 2016; 9:63. [PMID: 27267759 PMCID: PMC4897950 DOI: 10.1186/s13041-016-0243-1] [Citation(s) in RCA: 71] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2016] [Accepted: 05/25/2016] [Indexed: 01/12/2023] Open
Abstract
BACKGROUND Endothelial cell (EC) released microvesicles (EMVs) can affect various target cells by transferring carried genetic information. Astrocytes are the main components of the blood brain barrier (BBB) structure in the brain and participate in regulating BBB integrity and blood flow. The interactions between ECs and astrocytes are essential for BBB integrity in homeostasis and pathological conditions. Here, we studied the effects of human brain microvascular ECs released EMVs on astrocyte functions. Additionally, we investigated the effects of EMVs treated astrocytes on regulating BBB function and cerebral ischemic damage. RESULTS EMVs prepared from ECs cultured in normal condition (n-EMVs) or oxygen and glucose deprivation (OGD-EMVs) condition had diverse effects on astrocytes. The n-EMVs promoted, while the OGD-EMVs inhibited the proliferation of astrocytes via regulating PI3K/Akt pathway. Glial fibrillary acidic protein (GFAP) expression (marker of astrocyte activation) was up-regulated by n-EMVs, while down-regulated by OGD-EMVs. Meanwhile, n-EMVs inhibited but OGD-EMVs promoted the apoptosis of astrocytes accompanied by up/down-regulating the expression of Caspase-9 and Bcl-2. In the BBB model of ECs-astrocytes co-culture, the n-EMVs, conversely to OGD-EMVs, decreased the permeability of BBB accompanied with up-regulation of zonula occudens-1(ZO-1) and Claudin-5. In a transient cerebral ischemia mouse model, n-EMVs ameliorated, while OGD-EMVs aggravated, BBB disruption, local cerebral blood flow (CBF) reduction, infarct volume and neurological deficit score. CONCLUSIONS Our data suggest that EMVs diversely modulate astrocyte functions, BBB integrity and CBF, and could serve as a novel therapeutic target for ischemic stroke.
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Affiliation(s)
- Qunwen Pan
- Guangdong Key Laboratory of Age-Related Cardiac and Cerebral Diseases, Institute of Neurology, Affiliated Hospital of Guangdong Medical University, Zhanjiang, 524001, China
| | - Caixia He
- Guangdong Key Laboratory of Age-Related Cardiac and Cerebral Diseases, Institute of Neurology, Affiliated Hospital of Guangdong Medical University, Zhanjiang, 524001, China.,Guangdong Medical University, Zhanjiang, 524001, China
| | - Hua Liu
- College of Health Science, Wuhan Sports University, Wuhan, Hubei, 430000, China
| | - Xiaorong Liao
- Guangdong Key Laboratory of Age-Related Cardiac and Cerebral Diseases, Institute of Neurology, Affiliated Hospital of Guangdong Medical University, Zhanjiang, 524001, China
| | - Bingyan Dai
- Guangdong Key Laboratory of Age-Related Cardiac and Cerebral Diseases, Institute of Neurology, Affiliated Hospital of Guangdong Medical University, Zhanjiang, 524001, China
| | - Yanfang Chen
- Guangdong Key Laboratory of Age-Related Cardiac and Cerebral Diseases, Institute of Neurology, Affiliated Hospital of Guangdong Medical University, Zhanjiang, 524001, China.,Department of Pharmacology and Toxicology, Wright State University, Dayton, OH, 45435, USA.,Department of Neurology, Boonshoft School of Medicine, Wright State University, Dayton, OH, 45435, USA
| | - Yi Yang
- College of Health Science, Wuhan Sports University, Wuhan, Hubei, 430000, China
| | - Bin Zhao
- Guangdong Key Laboratory of Age-Related Cardiac and Cerebral Diseases, Institute of Neurology, Affiliated Hospital of Guangdong Medical University, Zhanjiang, 524001, China
| | - Ji Bihl
- Guangdong Key Laboratory of Age-Related Cardiac and Cerebral Diseases, Institute of Neurology, Affiliated Hospital of Guangdong Medical University, Zhanjiang, 524001, China. .,Department of Pharmacology and Toxicology, Wright State University, Dayton, OH, 45435, USA.
| | - Xiaotang Ma
- Guangdong Key Laboratory of Age-Related Cardiac and Cerebral Diseases, Institute of Neurology, Affiliated Hospital of Guangdong Medical University, Zhanjiang, 524001, China.
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29
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Shimizu M, Inoue N, Kuroda M, Mizuta M, Sugimoto N, Kaneda H, Ohta K, Yachie A. Angiopoietin-1 and -2 as markers for disease severity in hemolytic uremic syndrome induced by enterohemorrhagic Escherichia coli. Clin Exp Nephrol 2016; 21:76-82. [PMID: 26945868 DOI: 10.1007/s10157-016-1254-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2016] [Accepted: 02/24/2016] [Indexed: 11/30/2022]
Abstract
BACKGROUND Angiopoietin (Ang)-1 and -2 play important roles in maintaining vascular homeostasis. This study aimed to assess the roles of angiopoietin (Ang)-1 and -2 and to investigate the clinical significance of their serum levels in patients with hemolytic uremic syndrome (HUS) induced by enterohemorrhagic Escherichia coli (EHEC). METHODS Twenty patients with HUS and 15 healthy controls were studied. Serum Ang-1 and Ang-2 levels were quantified using enzyme-linked immunosorbent assay. The results were compared with the clinical features of HUS. RESULTS During the HUS phase, serum Ang-1 levels were significantly decreased, whereas serum Ang-2 levels and the Ang-2/Ang-1 ratio were significantly elevated. Compared with patients without encephalopathy, serum Ang-2 levels and Ang-2/Ang-1 ratio were significantly elevated in patients with encephalopathy. Patients with HUS and serum Ang-2 levels of >7061 pg/mL or Ang2/Ang1 ratios of >2.29 were at high risk of encephalopathy. Serum Ang-1 levels were significantly decreased in patients in the pre-HUS phase compared with those in healthy controls. CONCLUSION Disruption of homeostasis of vascular endothelial function by Ang-1 and -2 may be closely associated with the development of HUS. Serum Ang-1 and -2 levels and the Ang-2/Ang-1 ratio may be promising indicators of disease activity in HUS and the development of encephalopathy.
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Affiliation(s)
- Masaki Shimizu
- Department of Pediatrics, School of Medicine, Institute of Medical, Pharmaceutical and Health Sciences, Kanazawa University, 13-1 Takara-machi, Kanazawa, 920-8641, Japan.
| | - Natsumi Inoue
- Department of Pediatrics, School of Medicine, Institute of Medical, Pharmaceutical and Health Sciences, Kanazawa University, 13-1 Takara-machi, Kanazawa, 920-8641, Japan
| | - Mondo Kuroda
- Department of Pediatrics, School of Medicine, Institute of Medical, Pharmaceutical and Health Sciences, Kanazawa University, 13-1 Takara-machi, Kanazawa, 920-8641, Japan
| | - Mao Mizuta
- Department of Pediatrics, School of Medicine, Institute of Medical, Pharmaceutical and Health Sciences, Kanazawa University, 13-1 Takara-machi, Kanazawa, 920-8641, Japan
| | - Naotoshi Sugimoto
- Department of Physiology, School of Medicine, Institute of Medical, Pharmaceutical and Health Sciences, Kanazawa University, Kanazawa, Japan
| | - Hisashi Kaneda
- Department of Pediatrics, Toyama City Hospital, Toyama, Japan
| | - Kazuhide Ohta
- Department of Pediatrics, Kanazawa Medical Center, Kanazawa, Japan
| | - Akihiro Yachie
- Department of Pediatrics, School of Medicine, Institute of Medical, Pharmaceutical and Health Sciences, Kanazawa University, 13-1 Takara-machi, Kanazawa, 920-8641, Japan
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30
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Lucke-Wold BP, Logsdon AF, Smith KE, Turner RC, Alkon DL, Tan Z, Naser ZJ, Knotts CM, Huber JD, Rosen CL. Bryostatin-1 Restores Blood Brain Barrier Integrity following Blast-Induced Traumatic Brain Injury. Mol Neurobiol 2015; 52:1119-1134. [PMID: 25301233 PMCID: PMC5000781 DOI: 10.1007/s12035-014-8902-7] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2014] [Accepted: 09/24/2014] [Indexed: 02/08/2023]
Abstract
Recent wars in Iraq and Afghanistan have accounted for an estimated 270,000 blast exposures among military personnel. Blast traumatic brain injury (TBI) is the 'signature injury' of modern warfare. Blood brain barrier (BBB) disruption following blast TBI can lead to long-term and diffuse neuroinflammation. In this study, we investigate for the first time the role of bryostatin-1, a specific protein kinase C (PKC) modulator, in ameliorating BBB breakdown. Thirty seven Sprague-Dawley rats were used for this study. We utilized a clinically relevant and validated blast model to expose animals to moderate blast exposure. Groups included: control, single blast exposure, and single blast exposure + bryostatin-1. Bryostatin-1 was administered i.p. 2.5 mg/kg after blast exposure. Evan's blue, immunohistochemistry, and western blot analysis were performed to assess injury. Evan's blue binds to albumin and is a marker for BBB disruption. The single blast exposure caused an increase in permeability compared to control (t = 4.808, p < 0.05), and a reduction back toward control levels when bryostatin-1 was administered (t = 5.113, p < 0.01). Three important PKC isozymes, PKCα, PKCδ, and PKCε, were co-localized primarily with endothelial cells but not astrocytes. Bryostatin-1 administration reduced toxic PKCα levels back toward control levels (t = 4.559, p < 0.01) and increased the neuroprotective isozyme PKCε (t = 6.102, p < 0.01). Bryostatin-1 caused a significant increase in the tight junction proteins VE-cadherin, ZO-1, and occludin through modulation of PKC activity. Bryostatin-1 ultimately decreased BBB breakdown potentially due to modulation of PKC isozymes. Future work will examine the role of bryostatin-1 in preventing chronic neurodegeneration following repetitive neurotrauma.
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Affiliation(s)
- Brandon P Lucke-Wold
- Department of Neurosurgery, West Virginia University School of Medicine, Morgantown, WV, 26506, USA
- The Center for Neuroscience, West Virginia University School of Medicine, Morgantown, WV, 26506, USA
| | - Aric F Logsdon
- The Center for Neuroscience, West Virginia University School of Medicine, Morgantown, WV, 26506, USA
- Department of Basic Pharmaceutical Sciences, West Virginia University School of Pharmacy, Morgantown, WV, 26506, USA
| | - Kelly E Smith
- The Center for Neuroscience, West Virginia University School of Medicine, Morgantown, WV, 26506, USA
- Department of Basic Pharmaceutical Sciences, West Virginia University School of Pharmacy, Morgantown, WV, 26506, USA
| | - Ryan C Turner
- Department of Neurosurgery, West Virginia University School of Medicine, Morgantown, WV, 26506, USA
- The Center for Neuroscience, West Virginia University School of Medicine, Morgantown, WV, 26506, USA
| | - Daniel L Alkon
- Blanchette Rockefeller Neurosciences Institute, Morgantown, WV, 26506, USA
| | - Zhenjun Tan
- Department of Neurosurgery, West Virginia University School of Medicine, Morgantown, WV, 26506, USA
- The Center for Neuroscience, West Virginia University School of Medicine, Morgantown, WV, 26506, USA
| | - Zachary J Naser
- Department of Neurosurgery, West Virginia University School of Medicine, Morgantown, WV, 26506, USA
- The Center for Neuroscience, West Virginia University School of Medicine, Morgantown, WV, 26506, USA
- Office of Professional Studies in Health Sciences, Drexel University College of Medicine, Philadelphia, PA, 19102, USA
| | - Chelsea M Knotts
- Department of Neurosurgery, West Virginia University School of Medicine, Morgantown, WV, 26506, USA
| | - Jason D Huber
- The Center for Neuroscience, West Virginia University School of Medicine, Morgantown, WV, 26506, USA
- Department of Basic Pharmaceutical Sciences, West Virginia University School of Pharmacy, Morgantown, WV, 26506, USA
| | - Charles L Rosen
- Department of Neurosurgery, West Virginia University School of Medicine, Morgantown, WV, 26506, USA.
- The Center for Neuroscience, West Virginia University School of Medicine, Morgantown, WV, 26506, USA.
- Department of Neurosurgery, West Virginia University School of Medicine, One Medical Center Drive, Suite 4300, Health Sciences Center, PO Box 9183, Morgantown, WV, 26506-9183, USA.
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Tan Z, Lucke-Wold BP, Logsdon AF, Turner RC, Tan C, Li X, Hongpaison J, Alkon DL, Simpkins JW, Rosen CL, Huber JD. Bryostatin extends tPA time window to 6 h following middle cerebral artery occlusion in aged female rats. Eur J Pharmacol 2015; 764:404-412. [PMID: 26189021 PMCID: PMC4698807 DOI: 10.1016/j.ejphar.2015.07.035] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2015] [Revised: 07/14/2015] [Accepted: 07/15/2015] [Indexed: 02/08/2023]
Abstract
Blood-brain barrier (BBB) disruption and hemorrhagic transformation (HT) following ischemic/reperfusion injury contributes to post-stroke morbidity and mortality. Bryostatin, a potent protein kinase C (PKC) modulator, has shown promise in treating neurological injury. In the present study, we tested the hypothesis that administration of bryostatin would reduce BBB disruption and HT following acute ischemic stroke; thus, prolonging the time window for administering recombinant tissue plasminogen activator (r-tPA). Acute cerebral ischemia was produced by reversible occlusion of the right middle cerebral artery (MCAO) in 18-20-month-old female rats using an autologous blood clot with delayed r-tPA reperfusion. Bryostatin (or vehicle) was administered at 2 h post-MCAO and r-tPA was administered at 6 h post-MCAO. Functional assessment, lesion volume, and hemispheric swelling measurements were performed at 24 h post-MCAO. Assessment of BBB permeability, measurement of hemoglobin, assessment of matrix metalloproteinase (MMP) levels by gel zymography, and measurement of PKCε, PKCα, PKCδ expression by western blot were conducted at 24 h post-MCAO. Rats treated with bryostatin prior to r-tPA administration had decreased mortality and hemispheric swelling when compared with rats treated with r-tPA alone. Administration of bryostatin also limited BBB disruption and HT and down-regulated MMP-9 expression while up-regulating PKCε expression at 24 h post-MCAO. Bryostatin administration ameliorates BBB disruption and reduces the risk of HT by down-regulating MMP-9 activation and up-regulating PKCε. In this proof-of-concept study, bryostatin treatment lengthened the time-to-treatment window and enhanced the efficacy and safety of thrombolytic therapy.
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Affiliation(s)
- Zhenjun Tan
- Department of Neurosurgery, School of Medicine, United States
| | | | - Aric F Logsdon
- Department of Basic Pharmaceutical Science, School of Pharmacy, United States
| | - Ryan C Turner
- Department of Neurosurgery, School of Medicine, United States
| | - Cong Tan
- Department of Physiology and Pharmacology, School of Medicine, United States
| | - Xinlan Li
- Department of Neurosurgery, School of Medicine, United States
| | - Jarin Hongpaison
- Blanchette Rockfeller Neuroscience Institute, West Virginia University, United States
| | - Daniel L Alkon
- Blanchette Rockfeller Neuroscience Institute, West Virginia University, United States
| | - James W Simpkins
- Department of Physiology and Pharmacology, School of Medicine, United States
| | - Charles L Rosen
- Department of Neurosurgery, School of Medicine, United States
| | - Jason D Huber
- Department of Basic Pharmaceutical Science, School of Pharmacy, United States.
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Wevers NR, de Vries HE. Morphogens and blood-brain barrier function in health and disease. Tissue Barriers 2015; 4:e1090524. [PMID: 27141417 DOI: 10.1080/21688370.2015.1090524] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2015] [Revised: 08/26/2015] [Accepted: 08/30/2015] [Indexed: 12/22/2022] Open
Abstract
The microvasculature of the brain forms a protective blood-brain barrier (BBB) that ensures a homeostatic environment for the central nervous system (CNS), which is essential for optimal brain functioning. The barrier properties of the brain endothelial cells are maintained by cells surrounding the capillaries, such as astrocytes and pericytes. Together with the endothelium and a basement membrane, these supporting cells form the neurovascular unit (NVU). Accumulating evidence indicates that the supporting cells of the NVU release a wide variety of soluble factors that induce and control barrier properties in a concentration-dependent manner. The current review provides a comprehensive overview of how such factors, called morphogens, influence BBB integrity and functioning. Since impaired BBB function is apparent in numerous CNS disorders and is often associated with disease severity, we also discuss the potential therapeutic value of these morphogens, as they may represent promising therapies for a wide variety of CNS disorders.
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Affiliation(s)
| | - Helga E de Vries
- Department of Molecular Cell Biology and Immunology; Neuroscience Campus Amsterdam, VU University Medical Center ; Amsterdam, The Netherlands
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33
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Retinoic acid ameliorates blood–brain barrier disruption following ischemic stroke in rats. Pharmacol Res 2015; 99:125-36. [DOI: 10.1016/j.phrs.2015.05.014] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/14/2015] [Revised: 05/30/2015] [Accepted: 05/31/2015] [Indexed: 01/28/2023]
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Zhao Q, Hu J, Xiang J, Gu Y, Jin P, Hua F, Zhang Z, Liu Y, Zan K, Zhang Z, Zu J, Yang X, Shi H, Zhu J, Xu Y, Cui G, Ye X. Intranasal administration of human umbilical cord mesenchymal stem cells-conditioned medium enhances vascular remodeling after stroke. Brain Res 2015; 1624:489-496. [PMID: 26279113 DOI: 10.1016/j.brainres.2015.08.003] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2015] [Revised: 08/04/2015] [Accepted: 08/05/2015] [Indexed: 01/24/2023]
Abstract
Stem cell-based treatments have been reported to be a potential strategy for stroke. However, tumorigenic potential and low survival rates of transplanted cells could attenuate the efficacy of the stem cell-based treatments. The application of stem cell-condition medium (CM) may be a practicable approach to conquer these limitations. In this study, we investigated whether intranasal administration of human umbilical cord mesenchymal stem cells (hUCMSCs)-CM has the therapeutic effects in rats after stroke. Adult male rats were subjected to middle cerebral artery occlusion (MCAo) and were treated by intranasal routine with or without hUCMSCs-CM (1 ml/kg/d), starting 24h after MCAo and daily for 14 days. Neurological functional tests, blood brain barrier (BBB) leakage, were measured. Angiogenesis and angiogenic factor expression were measured by immunohistochemistry, and Western blot, respectively. hUCMSCs-CM treatment of stroke by intranasal routine starting 24h after MCAo in rats significantly enhances BBB functional integrity and promotes functional outcome but does not decrease lesion volume compared to rats in DMEM/F12 medium control group and saline control group. Treatment of ischemic rats with hUCMSCs-CM by intranasal routine also significantly decreases the levels of Ang2 and increases the levels of both Ang1 and Tie2 in the ischemic brain. To take together, increased expression of Ang1 and Tie2 and decreased expression of Ang2, induced by hUCMSCs-CM treatment, contribute to vascular remodeling in the ischemic brain which plays an important role in functional outcome after stroke.
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Affiliation(s)
- Qiuchen Zhao
- Department of Neurology, Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, Jiangsu, China
| | - Jinxia Hu
- Department of Neurology, The Affiliated Hospital of Xuzhou Medical College, Xuzhou, Jiangsu, China
| | - Jie Xiang
- Department of Rehabilitation Medicine, The Affiliated Hospital of Xuzhou Medical College, Xuzhou, Jiangsu, China
| | - Yuming Gu
- Department of Interventional Radiology, The Affiliated Hospital of Xuzhou Medical College, Xuzhou, Jiangsu, China
| | - Peisheng Jin
- Department of Plastic Surgery, The Affiliated Hospital of Xuzhou Medical College, Xuzhou, Jiangsu, China
| | - Fang Hua
- Department of Neurology, The Affiliated Hospital of Xuzhou Medical College, Xuzhou, Jiangsu, China
| | - Zunsheng Zhang
- Department of Neurology, The Affiliated Hospital of Xuzhou Medical College, Xuzhou, Jiangsu, China
| | - Yonghai Liu
- Department of Neurology, The Affiliated Hospital of Xuzhou Medical College, Xuzhou, Jiangsu, China
| | - Kun Zan
- Department of Neurology, The Affiliated Hospital of Xuzhou Medical College, Xuzhou, Jiangsu, China
| | - Zuohui Zhang
- Department of Neurology, The Affiliated Hospital of Xuzhou Medical College, Xuzhou, Jiangsu, China
| | - Jie Zu
- Department of Neurology, The Affiliated Hospital of Xuzhou Medical College, Xuzhou, Jiangsu, China
| | - Xinxin Yang
- Department of Neurology, The Affiliated Hospital of Xuzhou Medical College, Xuzhou, Jiangsu, China
| | - Hongjuan Shi
- Department of Neurology, The Affiliated Hospital of Xuzhou Medical College, Xuzhou, Jiangsu, China
| | - Jienan Zhu
- Department of Neurology, The Affiliated Hospital of Xuzhou Medical College, Xuzhou, Jiangsu, China
| | - Yun Xu
- Department of Neurology, Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, Jiangsu, China
| | - Guiyun Cui
- Department of Neurology, The Affiliated Hospital of Xuzhou Medical College, Xuzhou, Jiangsu, China
| | - Xinchun Ye
- Department of Neurology, The Affiliated Hospital of Xuzhou Medical College, Xuzhou, Jiangsu, China.
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Levo-tetrahydropalmatine attenuates mouse blood-brain barrier injury induced by focal cerebral ischemia and reperfusion: Involvement of Src kinase. Sci Rep 2015; 5:11155. [PMID: 26059793 PMCID: PMC4461916 DOI: 10.1038/srep11155] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2015] [Accepted: 05/18/2015] [Indexed: 11/18/2022] Open
Abstract
The restoration of blood flow following thrombolytic therapy causes ischemia and reperfusion (I/R) injury leading to blood-brain barrier (BBB) disruption and subsequent brain edema in patients of ischemic stroke. Levo-tetrahydropalmatine (l-THP) occurs in Corydalis genus and some other plants. However, whether l-THP exerts protective role on BBB disrpution following cerebral I/R remains unclear. Male C57BL/6N mice (23 to 28 g) were subjected to 90 min middle cerebral artery occlusion, followed by reperfusion for 24 h. l-THP (10, 20, 40 mg/kg) was administrated by gavage 60 min before ischemia. We found I/R evoked Evans blue extravasation, albumin leakage, brain water content increase, cerebral blood flow decrease, cerebral infarction and neurological deficits, all of which were attenuated by l-THP treatment. Meanwhile, l-THP inhibited tight junction (TJ) proteins down-expression, Src kinase phosphorylation, matrix metalloproteinases-2/9 (MMP-2/9) and caveolin-1 activation. In addition, surface plasmon resonance revealed binding of l-THP to Src kinase with high affinity. Then we found Src kinase inhibitor PP2 could attenuate Evans blue dye extravasation and inhibit the caveolin-1, MMP-9 activation, occludin down-expression after I/R, respectively. In conclusion, l-THP attenuated BBB injury and brain edema, which were correlated with inhibiting the Src kinase phosphorylation.
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Zhang HF, Li TB, Liu B, Lou Z, Zhang JJ, Peng JJ, Zhang XJ, Ma QL, Peng J, Luo XJ. Inhibition of myosin light chain kinase reduces NADPH oxidase-mediated oxidative injury in rat brain following cerebral ischemia/reperfusion. NAUNYN-SCHMIEDEBERG'S ARCHIVES OF PHARMACOLOGY 2015; 388:953-63. [PMID: 25920934 DOI: 10.1007/s00210-015-1125-2] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2015] [Accepted: 04/08/2015] [Indexed: 11/29/2022]
Abstract
Previous studies have demonstrated that nicotinamide adenine dinucleotide phosphate (NADPH) oxidase (NOX)-mediated oxidative stress plays a key role in brain injury following cerebral ischemia/reperfusion (I/R) and myosin regulatory light chain kinase (MLCK) has been reported to be involved in NOX activation in lung endothelium. This study was performed to explore the correlation between MLCK and NOX following cerebral I/R and the underlying mechanisms. Sprague-Dawley (SD) rats were subjected to 2 h middle cerebral artery occlusion and 24 h reperfusion to establish a model of focal cerebral I/R injury. At the end of experiments, neurological function, infarct volume, cellular apoptosis, activities of MLCK and NOX, messenger RNA (mRNA) and protein expression of NOX (NOX1-NOX4), phosphorylation level of myosin regulatory light chain (MLC20) and hydrogen peroxide (H2O2) level were determined. The results showed that I/R treatment led to increase in neurological deficit score, infarct volume and cellular apoptosis, accompanied by the elevated activities of MLCK and NOX, expressions of NOX2 and NOX4, levels of phosphorylation MLC20 and H2O2, these effects were attenuated by MLCK specific inhibitor (ML-7). NOX inhibitors (diphenylene iodonium (DPI) or apocynin) were able to achieve similar results to that of ML-7 except no effect on MLCK activity and MLC20 phosphorylation. These results suggest that activation of MLCK contributes to cerebral I/R oxidative injury through upregulation of NOX2 and NOX4 expression, which is involved in phosphorylation of MLC20.
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Affiliation(s)
- Hong-Feng Zhang
- Department of Pharmacology, School of Pharmaceutical Sciences, Central South University, Changsha, 410078, China
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Blood-brain barrier breakdown involves four distinct stages of vascular damage in various models of experimental focal cerebral ischemia. J Cereb Blood Flow Metab 2015; 35:292-303. [PMID: 25425076 PMCID: PMC4426746 DOI: 10.1038/jcbfm.2014.199] [Citation(s) in RCA: 151] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/25/2014] [Revised: 10/16/2014] [Accepted: 10/17/2014] [Indexed: 12/18/2022]
Abstract
Ischemic stroke not only impairs neuronal function but also affects the cerebral vasculature as indicated by loss of blood-brain barrier (BBB) integrity. Therefore, therapeutical recanalization includes an enhanced risk for hemorrhagic transformation and bleeding, traditionally attributed to a 'reperfusion injury'. To investigate the mechanisms underlying ischemia-/reperfusion-related BBB opening, we applied multiple immunofluorescence labeling and electron microscopy in a rat model of thromboembolic stroke as well as mouse models of permanent and transient focal cerebral ischemia. In these models, areas exhibiting BBB breakdown were identified by extravasation of intravenously administered fluorescein isothiocyanate (FITC)-albumin. After 24 hours, expression of markers for tight and adherens junctions in areas of FITC-albumin leakage consistently remained unaltered in the applied models. However, lectin staining with isolectin B4 indicated structural alterations in the endothelium, which were confirmed by electron microscopy. While ultrastructural alterations in endothelial cells did not differ between the applied models including the reperfusion scenario, we regularly identified vascular alterations, which we propose to reflect four distinct stages of BBB breakdown with ultimate loss of endothelial cells. Therefore, our data strongly suggest that ischemia-related BBB failure is predominantly caused by endothelial degeneration. Thus, protecting endothelial cells may represent a promising therapeutical approach in addition to the established recanalizing strategies.
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The angiopoietin/TIE receptor system: Focusing its role for ischemia-reperfusion injury. Cytokine Growth Factor Rev 2014; 26:281-91. [PMID: 25466648 DOI: 10.1016/j.cytogfr.2014.10.013] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2014] [Revised: 10/23/2014] [Accepted: 10/30/2014] [Indexed: 02/07/2023]
Abstract
Ischemia and reperfusion (I/R) are of fatal consequence for the affected organs, as they provoke a profound inflammatory reaction. This thoroughly destroys cells and tissues, inducing functional failure or even complete loss of organ function. Since I/R is primarily a vascular problem, the interaction between the endothelium and the surrounding environment is of great significance. The angiopoietins (ANG) and the TIE receptors are key players for the vascular homeostasis. This review summarizes biochemical and cellular mechanisms leading to I/R injury. After a brief introduction to the ANG/TIE system, a comprehensive overview of its role for the development of I/R syndrome is given. Finally, current therapeutic approaches to mitigate the consequences of I/R by modulating ANG/TIE signaling are reviewed in detail.
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Attenuated Blood-Brain Barrier Dysfunction by XQ-1H Following Ischemic Stroke in Hyperlipidemic Rats. Mol Neurobiol 2014; 52:162-75. [DOI: 10.1007/s12035-014-8851-1] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2014] [Accepted: 07/31/2014] [Indexed: 01/16/2023]
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Electroacupuncture treatment improves neurological function associated with regulation of tight junction proteins in rats with cerebral ischemia reperfusion injury. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2014; 2014:989340. [PMID: 25009574 PMCID: PMC4070389 DOI: 10.1155/2014/989340] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/02/2014] [Accepted: 05/26/2014] [Indexed: 11/30/2022]
Abstract
Strategies to develop effective neuroprotective therapy to reduce brain damage and related behavioral deficits in stroke patients are of great significance. Electroacupuncture (EA), which derives from traditional Chinese medicine, may be effective as a complementary and alternative method for promoting recovery of neurological function and quality of life. Adult Sprague-Dawley rats were randomly divided into 3 groups: (1) sham, (2) middle cerebral artery occlusion (MCAO) model groups of 2 h MCAO followed by 1, 3, 5, or 7 d of reperfusion, and (3) EA groups of 2 h MCAO followed by 1, 3, 5, or 7 d of reperfusion. EA groups received EA therapy by needling at GV20 and left ST36. The results show that EA therapy improved the neurological function and reduced infarct volume, confirmed by modified neurological severity scores and TTC staining. Real-time PCR, immunohistochemistry, and western blot assay verified that EA upregulated the expression of tight junction (TJ) claudin-5, occludin, and zonula occluding-1 from 1 to 7 d after reperfusion. Our findings suggest that EA reduces brain damage and related behavioral deficits via upregulation of the TJ proteins.
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Kawamura K, Takahashi T, Kanazawa M, Igarashi H, Nakada T, Nishizawa M, Shimohata T. Effects of angiopoietin-1 on hemorrhagic transformation and cerebral edema after tissue plasminogen activator treatment for ischemic stroke in rats. PLoS One 2014; 9:e98639. [PMID: 24896569 PMCID: PMC4045756 DOI: 10.1371/journal.pone.0098639] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2013] [Accepted: 05/06/2014] [Indexed: 01/01/2023] Open
Abstract
An angiogenesis factor, angiopoietin-1 (Ang1), is associated with the blood-brain barrier (BBB) disruption after focal cerebral ischemia. However, whether hemorrhagic transformation and cerebral edema after tissue plasminogen activator (tPA) treatment are related to the decrease in Ang1 expression in the BBB remains unknown. We hypothesized that administering Ang1 might attenuate hemorrhagic transformation and cerebral edema after tPA treatment by stabilizing blood vessels and inhibiting hyperpermeability. Sprague-Dawley rats subjected to thromboembolic focal cerebral ischemia were assigned to a permanent ischemia group (permanent middle cerebral artery occlusion; PMCAO) and groups treated with tPA at 1 h or 4 h after ischemia. Endogenous Ang1 expression was observed in pericytes, astrocytes, and neuronal cells. Western blot analyses revealed that Ang1 expression levels on the ischemic side of the cerebral cortex were decreased in the tPA-1h, tPA-4h, and PMCAO groups as compared to those in the control group (P = 0.014, 0.003, and 0.014, respectively). Ang1-positive vessel densities in the tPA-4h and PMCAO groups were less than that in the control group (p = 0.002 and <0.001, respectively) as well as that in the tPA-1h group (p = 0.047 and 0.005, respectively). These results suggest that Ang1-positive vessel density was maintained when tPA was administered within the therapeutic time window (1 h), while it was decreased when tPA treatment was given after the therapeutic time window (4 h). Administering Ang1 fused with cartilage oligomeric protein (COMP) to supplement this decrease has the potential to suppress hemorrhagic transformation as measured by hemoglobin content in a whole cerebral homogenate (p = 0.007) and cerebral edema due to BBB damage (p = 0.038), as compared to administering COMP protein alone. In conclusion, Ang1 might be a promising target molecule for developing vasoprotective therapies for controlling hemorrhagic transformation and cerebral edema after tPA treatment.
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Affiliation(s)
- Kunio Kawamura
- Department of Neurology, Brain Research Institute, Niigata University, Niigata, Japan
| | - Tetsuya Takahashi
- Department of Neurology, Brain Research Institute, Niigata University, Niigata, Japan
| | - Masato Kanazawa
- Department of Neurology, Brain Research Institute, Niigata University, Niigata, Japan
| | - Hironaka Igarashi
- Department of Center for Integrated Human Brain Science, Brain Research Institute, Niigata University, Niigata, Japan
| | - Tsutomu Nakada
- Department of Center for Integrated Human Brain Science, Brain Research Institute, Niigata University, Niigata, Japan
| | - Masatoyo Nishizawa
- Department of Neurology, Brain Research Institute, Niigata University, Niigata, Japan
| | - Takayoshi Shimohata
- Department of Neurology, Brain Research Institute, Niigata University, Niigata, Japan
- * E-mail:
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Redzic ZB, Rabie T, Sutherland BA, Buchan AM. Differential effects of paracrine factors on the survival of cells of the neurovascular unit during oxygen glucose deprivation. Int J Stroke 2013; 10:407-14. [PMID: 24206924 DOI: 10.1111/ijs.12197] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2013] [Accepted: 08/05/2013] [Indexed: 12/12/2022]
Abstract
BACKGROUND Disruption of the neurovascular unit following cerebral ischemia affects protective function of the blood-brain barrier, thus contributing to vasogenic edema and hemorrhagic transformation. AIMS This study explored the effects of mediators released from neurovascular unit cells on death of brain endothelial cells, astrocytes, pericytes, and microglia during oxygen glucose deprivation. METHODS Rat primary cell cultures were exposed either to oxygen glucose deprivation or control conditions. Cell death and released angiogenic factors were assessed from media collected from cultures. For some experiments, astrocyte-conditioned media, pericyte-conditioned media, and microglia-conditioned media, collected from the corresponding cell culture after six-hour oxygen glucose deprivation, were added to the media during oxygen glucose deprivation incubations. RESULTS Brain endothelial cells were more susceptible to death following oxygen glucose deprivation than other neurovascular unit cells. Neither astrocyte-conditioned media nor vascular endothelial growth factor165 were protective for pericytes or brain endothelial cells during oxygen glucose deprivation. Vascular endothelial growth factor receptor antagonist significantly reduced cell death of brain endothelial cells treated with astrocyte-conditioned media or vascular endothelial growth factor165. Pericyte-conditioned media were protective for brain endothelial cells and microglia, but this was not mediated by pericyte-released angiopoietin 1. Soluble angiopoietin 1/angiopoietin 2 receptor Tie2 was protective for brain endothelial cells. Microglia-conditioned media were protective for astrocytes and brain endothelial cells, possibly through transforming growth factor β1 or interleukin 6. CONCLUSION Microglia-derived signaling molecules, but not angiogenic factors, were protective for neurovascular unit cells during oxygen glucose deprivation. This finding could identify a potential therapeutic target for ischemic stroke.
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Affiliation(s)
- Zoran B Redzic
- Acute Stroke Programme, Radcliffe Department of Medicine, University of Oxford, Oxford, UK; Department of Physiology, Faculty of Medicine, Kuwait University, Safat, Kuwait
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Hu YJ, Wang YD, Tan FQ, Yang WX. Regulation of paracellular permeability: factors and mechanisms. Mol Biol Rep 2013; 40:6123-42. [PMID: 24062072 DOI: 10.1007/s11033-013-2724-y] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2012] [Accepted: 09/14/2013] [Indexed: 12/20/2022]
Abstract
Epithelial permeability is composed of transcellular permeability and paracellular permeability. Paracellular permeability is controlled by tight junctions (TJs). Claudins and occludin are two major transmembrane proteins in TJs, which directly determine the paracellular permeability to different ions or large molecules. Intracellular signaling pathways including Rho/Rho-associated protein kinase, protein kinase Cs, and mitogen-activated protein kinase, modulate the TJ proteins to affect paracellular permeability in response for diverse stimuli. Cytokines, growth factors and hormones in organism can regulate the paracellular permeability via signaling pathway. The transcellular transporters such as Na-K-ATPase, Na(+)-coupled transporters and chloride channels, can interact with paracellular transport and regulate the TJs. In this review, we summarized the factors affecting paracellular permeability and new progressions of the related mechanism in recent studies, and pointed out further research areas.
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Affiliation(s)
- Yan-Jun Hu
- Department of Reproductive Endocrinology, Women's Hospital, School of Medicine, Zhejiang University, Hangzhou, 310006, People's Republic of China
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Xia YP, He QW, Li YN, Chen SC, Huang M, Wang Y, Gao Y, Huang Y, Wang MD, Mao L, Hu B. Recombinant human sonic hedgehog protein regulates the expression of ZO-1 and occludin by activating angiopoietin-1 in stroke damage. PLoS One 2013; 8:e68891. [PMID: 23894369 PMCID: PMC3720889 DOI: 10.1371/journal.pone.0068891] [Citation(s) in RCA: 75] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2013] [Accepted: 06/01/2013] [Indexed: 01/23/2023] Open
Abstract
This study examines the regulating effect of Sonic Hedgehog (Shh) on the permeability of the blood-brain barrier (BBB) in cerebral ischemia. By employing permanent middle cerebral artery occlusion (pMCAO) model, we find that Shh significantly decreases brain edema and preserves BBB permeability. Moreover, Shh increases zonula occludens-1 (ZO-1), occludin and angiopiotetin-1 (Ang-1) expression in the ischemic penumbra. Blockage of Shh with cyclopamine abolishes the effects of Shh on brain edema, BBB permeability and ZO-1, occludin, Ang-1 expression. Primary brain microvessel endothelial cells (BMECs) and astrocytes were pre-treated with Shh, cyclopamine, Ang-1-neutralizing antibody, and subjected to oxygen-glucose deprivation (OGD). Results show that the Ang-1 protein level in the culture medium of Shh-treated astrocytes is significantly higher. Shh also increased ZO-1, occludin and Ang-1 expression in BMECs, while cyclopamine and Ang-1-neutralizing antibody inhibited the effects of Shh on the ZO-1 and occludin expression, respectively. This study suggests that, under ischemic insults, Shh triggers Ang-1 production predominantly in astrocytes, and the secreted Ang-1 acts on BMECs, thereby upregulating ZO-1 and occludin to repair the tight junction and ameliorate the brain edema and BBB leakage.
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Affiliation(s)
- Yuan-peng Xia
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Quan-wei He
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Ya-nan Li
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Sheng-cai Chen
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Ming Huang
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Yong Wang
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Yuan Gao
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Yan Huang
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Meng-die Wang
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Ling Mao
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Bo Hu
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
- * E-mail:
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Green tea polyphenols alleviate early BBB damage during experimental focal cerebral ischemia through regulating tight junctions and PKCalpha signaling. Altern Ther Health Med 2013; 13:187. [PMID: 23870286 PMCID: PMC3723424 DOI: 10.1186/1472-6882-13-187] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2012] [Accepted: 07/17/2013] [Indexed: 11/22/2022]
Abstract
Background It has been supposed that green tea polyphenols (GTPs) have neuroprotective effects on brain damage after brain ischemia in animal experiments. Little is known regarding GTPs’ protective effects against the blood-brain barrier (BBB) disruption after ischemic stroke. We investigated the effects of GTPs on the expression of claudin-5, occludin, and ZO-1, and the corresponding cellular mechanisms involved in the early stage of cerebral ischemia. Methods Male Wistar rats were subjected to a middle cerebral artery occlusion (MCAO) for 0, 30, 60, and 120 min. GTPs (400 mg/kg/day) or vehicle was administered by intragastric gavage twice a day for 30 days prior to MCAO. At different time points, the expression of claudin-5, occludin, ZO-1, and PKCα signaling pathway in microvessel fragments of cerebral ischemic tissue were evaluated. Results GTPs reduced BBB permeability at 60 min and 120 min after ischemia as compared with the vehicle group. Transmission electron microscopy also revealed that GTPs could reverse the opening of tight junction (TJ) barrier at 60 min and 120 min after MACO. The decreased mRNA and protein expression levels of claudin-5, occludin, and ZO-1 in microvessel fragments of cerebral ischemic tissue were significantly prevented by treatment with GTPs at the same time points after ischemia in rats. Furthermore, GTPs could attenuate the increase in the expression levels of PKCα mRNA and protein caused by cerebral ischemia. Conclusions These results demonstrate that GTPs may act as a potential neuroprotective agent against BBB damage at the early stage of focal cerebral ischemia through the regulation of TJ and PKCα signaling.
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Moriyama Y, Takagi N, Hashimura K, Itokawa C, Tanonaka K. Intravenous injection of neural progenitor cells facilitates angiogenesis after cerebral ischemia. Brain Behav 2013; 3:43-53. [PMID: 23532762 PMCID: PMC3607146 DOI: 10.1002/brb3.113] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/18/2012] [Revised: 11/19/2012] [Accepted: 11/26/2012] [Indexed: 01/19/2023] Open
Abstract
Earlier we demonstrated that the injection of neural progenitor cells (NPCs) has therapeutic potential for the improvement of learning dysfunction after cerebral ischemia. However, it remained to be clarified how transplantation of NPCs can improve ischemia-induced dysfunction. In this study, we examined whether intravenous injection of NPCs after cerebral ischemia could enhance angiogenesis by affecting the expression of angiogenic factors. The injection of NPCs on day 7 after cerebral ischemia enhanced angiogenesis on day 28. Vascular endothelial growth factor (VEGF) and its receptor VEGFR2 were increased in expression by the NPC injection. The level of angiopoietin-1 (Ang-1), an angiogenic factor, but not that of Ang-2, which acts as an antagonist for the Ang-1 receptor, was also increased on day 28. In addition, the expression of Ang-1 receptor Tie2 was enhanced in brain capillaries. Furthermore, the amounts of tight junctional proteins, which are in the blood-brain barrier and whose expression occurs downstream of Ang-1/Tie2 signaling, were increased by the NPC injection. These results suggest that the NPC injection promoted angiogenesis through Ang-1/Tie2 and/or VEGF/VEGFR2 signaling in brain capillaries after cerebral ischemia. Such signaling might have the potential for causing vascular stabilization and maturation for a long period after cerebral ischemia.
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Affiliation(s)
- Yoshiyuki Moriyama
- Department of Molecular and Cellular Pharmacology, Tokyo University of Pharmacy and Life Sciences 1432-1 Horinouchi, Hachioji, Tokyo, 192-0392, Japan
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Krueger M, Härtig W, Reichenbach A, Bechmann I, Michalski D. Blood-brain barrier breakdown after embolic stroke in rats occurs without ultrastructural evidence for disrupting tight junctions. PLoS One 2013; 8:e56419. [PMID: 23468865 PMCID: PMC3582567 DOI: 10.1371/journal.pone.0056419] [Citation(s) in RCA: 126] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2012] [Accepted: 01/09/2013] [Indexed: 12/27/2022] Open
Abstract
The term blood-brain barrier (BBB) relates to the ability of cerebral vessels to hold back hydrophilic and large molecules from entering the brain, thereby crucially contributing to brain homeostasis. In fact, experimental opening of endothelial tight junctions causes a breakdown of the BBB evidenced as for instance by albumin leakage. This and similar observations led to the conclusion that BBB breakdown is predominantly mediated by damage to tight junction complexes, but evidentiary ultrastructural data are rare. Since functional deficits of the BBB contribute to an increased risk of hemorrhagic transformation and brain edema after stroke, which both critically impact on the clinical outcome, we studied the mechanism of BBB breakdown using an embolic model of focal cerebral ischemia in Wistar rats to closely mimic the essential human pathophysiology. Ischemia-induced BBB breakdown was detected using intravenous injection of FITC-albumin and tight junctions in areas of FITC-albumin extravasation were subsequently studied using fluorescence and electron microscopy. Against our expectation, 25 hours after ischemia induction the morphology of tight junction complexes (identified ultrastructurally and using antibodies against the transcellular proteins occludin and claudin-5) appeared to be regularly maintained in regions where FITC-albumin massively leaked into the neuropil. Furthermore, occludin signals along pan-laminin-labeled vessels in the affected hemisphere equaled the non-affected contralateral side (ratio: 0.966 vs. 0.963; P = 0.500). Additional ultrastructural analyses at 5 and 25 h after ischemia induction clearly indicated FITC-albumin extravasation around vessels with intact tight junctions, while the endothelium exhibited enhanced transendothelial vesicle trafficking and signs of degeneration. Thus, BBB breakdown and leakage of FITC-albumin cannot be correlated with staining patterns for common tight junction proteins alone. Understanding the mechanisms causing functional endothelial alterations and endothelial damage is likely to provide novel protective targets in stroke.
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Affiliation(s)
- Martin Krueger
- Institute of Anatomy, University of Leipzig, Leipzig, Germany
- * E-mail: (MK); (DM)
| | - Wolfgang Härtig
- Paul Flechsig Institute of Brain Research, University of Leipzig, Leipzig, Germany
| | - Andreas Reichenbach
- Paul Flechsig Institute of Brain Research, University of Leipzig, Leipzig, Germany
| | - Ingo Bechmann
- Institute of Anatomy, University of Leipzig, Leipzig, Germany
| | - Dominik Michalski
- Department of Neurology, University of Leipzig, Leipzig, Germany
- * E-mail: (MK); (DM)
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Morin-Brureau M, De Bock F, Lerner-Natoli M. Organotypic brain slices: a model to study the neurovascular unit micro-environment in epilepsies. Fluids Barriers CNS 2013; 10:11. [PMID: 23391266 PMCID: PMC3605299 DOI: 10.1186/2045-8118-10-11] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2012] [Accepted: 01/28/2013] [Indexed: 12/22/2022] Open
Abstract
Background It is now recognized that the neuro-vascular unit (NVU) plays a key role in several neurological diseases including epilepsy, stroke, Alzheimer’s disease, multiple sclerosis and the development of gliomas. Most of these disorders are associated with NVU dysfunction, due to overexpression of inflammatory factors such as vascular endothelial growth factor (VEGF). Various in vitro models have been developed previously to study the micro-environment of the blood–brain barrier (BBB). However none of these in vitro models contained a complete complement of NVU cells, nor maintained their interactions, thus minimizing the influence of the surrounding tissue on the BBB development and function. The organotypic hippocampal culture (OHC) is an integrative in vitro model that allows repeated manipulations over time to further understand the development of cell circuits or the mechanisms of brain diseases. Methods/design OHCs were cultured from hippocampi of 6–7 day-old Sprague Dawley rats. After 2 weeks in culture, seizures were induced by application of kainate or bicuculline into culture medium. The regulation of BBB integrity under physiological and pathological conditions was evaluated by immunostaining of the main tight junction (TJ) proteins and of the basal membrane of microvessels. To mimic or prevent BBB disassembly, we used diverse pro- or anti-angiogenic treatments. Discussion This study demonstrates that NVU regulation can be investigated using OHCs. We observed in this model system an increase in vascularization and a down-regulation of TJ proteins, similar to the vascular changes described in a chronic focus of epileptic patients, and in rodent models of epilepsy or inflammation. We observed that Zonula occludens-1 (ZO-1) protein disappeared after seizures associated with neuronal damage. In these conditions, the angiopoeitin-1 system was down-regulated, and the application of r-angiopoeitin-1 allowed TJ re-assembly. This article demonstrates that organotypic culture is a useful model to decipher the links between epileptic activity and vascular damage, and also to investigate NVU regulation in diverse neurological disorders.
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Affiliation(s)
- Mélanie Morin-Brureau
- Institut de Génomique Fonctionnelle, CNRS UMR5203, INSERM U661, Université Montpellier 1, 2, Montpellier, France.
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Khan M, Dhammu TS, Sakakima H, Shunmugavel A, Gilg AG, Singh AK, Singh I. The inhibitory effect of S-nitrosoglutathione on blood-brain barrier disruption and peroxynitrite formation in a rat model of experimental stroke. J Neurochem 2012; 123 Suppl 2:86-97. [PMID: 23050646 PMCID: PMC3481195 DOI: 10.1111/j.1471-4159.2012.07947.x] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The hallmark of stroke injury is endothelial dysfunction leading to blood-brain barrier (BBB) leakage and edema. Among the causative factors of BBB disruption are accelerating peroxynitrite formation and the resultant decreased bioavailability of nitric oxide (NO). S-nitrosoglutathione (GSNO), an S-nitrosylating agent, was found not only to reduce the levels of peroxynitrite but also to protect the integrity of BBB in a rat model of cerebral ischemia and reperfusion (IR). A treatment with GSNO (3 μmol/kg) after IR reduced 3-nitrotyrosine levels in and around vessels and maintained NO levels in brain. This mechanism protected endothelial function by reducing BBB leakage, increasing the expression of Zonula occludens-1 (ZO-1), decreasing edema, and reducing the expression of matrix metalloproteinase-9 and E-selectin in the neurovascular unit. An administration of the peroxynitrite-forming agent 3-morpholino sydnonimine (3 μmol/kg) at reperfusion increased BBB leakage and decreased the expression of ZO-1, supporting the involvement of peroxynitrite in BBB disruption and edema. Mechanistically, the endothelium-protecting action of GSNO was invoked by reducing the activity of nuclear factor kappa B and increasing the expression of S-nitrosylated proteins. Taken together, the results support the ability of GSNO to improve endothelial function by reducing nitroxidative stress in stroke.
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Affiliation(s)
- Mushfiquddin Khan
- Department of Pediatrics, Medical University of South Carolina, Charleston, SC
| | - Tajinder S Dhammu
- Department of Pediatrics, Medical University of South Carolina, Charleston, SC
| | - Harutoshi Sakakima
- Department of Pediatrics, Medical University of South Carolina, Charleston, SC
| | | | - Anne G Gilg
- Department of Pediatrics, Medical University of South Carolina, Charleston, SC
| | - Avtar K. Singh
- Department of Pathology and Laboratory Medicine, Medical University of South Carolina, Charleston, SC
- Ralph H. Johnson VA Medical Center, Charleston, SC
| | - Inderjit Singh
- Department of Pediatrics, Medical University of South Carolina, Charleston, SC
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