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Gao F, Du W, Guo C, Geng P, Liu W, Jin X. α7nACh receptor, a promising target to reduce BBB damage by regulating inflammation and autophagy after ischemic stroke. Biomed Pharmacother 2024; 179:117337. [PMID: 39191022 DOI: 10.1016/j.biopha.2024.117337] [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: 05/04/2024] [Revised: 08/13/2024] [Accepted: 08/21/2024] [Indexed: 08/29/2024] Open
Abstract
Increased blood-brain barrier (BBB) permeability can lead to cerebral vasogenic edema and hemorrhagic transformation (HT) after reperfusion with tissue plasminogen activator (tPA), the only United States Food and Drug Administration (FDA)-approved treatment for acute ischemia stroke (AIS). The therapeutic benefits of tPA after AIS are partially outweighed by a more than a six-fold increase in the risk of symptomatic intracerebral hemorrhage. Therefore, strategies to protect the integrity of BBB are urgently needed to reduce HT and vasogenic edema after tPA thrombolysis or endovascular thrombectomy. Interestingly, an NIH study showed that smokers treated with tPA had a significantly lower prevalence of brain hemorrhage than nonsmokers, suggesting that cigarette smoking may protect patients treated with tPA from the side effects of cerebral hemorrhage. Importantly, we recently showed that treatment with nicotine reduces AIS-induced BBB damage and that modulating α7nAChR by modulation could reduce ischemia/reperfusion-induced BBB damage, suggesting that α7nAChR could be a potential target to reduce BBB after AIS. In this review, we first provide an overview of stroke and the impact of α7nAChR activation on BBB damage. Next, we discuss the features and mechanism of BBB destruction after AIS. We then discuss the effect of nicotine effect on BBB integrity as well as the mechanism underlying those effects. Finally, we discuss the side effects and potential strategies for modulating α7nAChR to reduce AIS-induced BBB damage.
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Affiliation(s)
- Fengying Gao
- Department of Emergency, Shanxi Provincial People's Hospital, Taiyuan 030001, 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
| | - Chun Guo
- School of Biosciences, University of Sheffield, Firth Court, Western Bank, Sheffield, UK
| | - Panpan Geng
- 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
| | - Wencao Liu
- Department of Emergency, Shanxi Provincial People's Hospital, Taiyuan 030001, 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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2
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Wang C, Dong J, Huang H, Zhou K, Liu Z, Milner R, Li L. Astrocyte-TREM2 alleviates brain injury by regulating reactive astrocyte states following ischemic stroke. Glia 2024. [PMID: 39056459 DOI: 10.1002/glia.24597] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2024] [Revised: 06/08/2024] [Accepted: 07/14/2024] [Indexed: 07/28/2024]
Abstract
Triggering receptor expressed on myeloid cells 2 (TREM2) has been shown to confer strong neuroprotective effects in acute ischemic stroke (AIS). However, as the vast majority of research findings to date are based on its functions in microglia, the precise role of TREM2 in astrocytes after AIS is unknown. Here, both loss- and gain-of-function experiments were employed to investigate how astrocytic TREM2 influences the pathogenesis of AIS in vivo and in vitro. Our results demonstrated that cerebral ischemia triggered induction of TREM2 expression on reactive astrocytes following AIS. In addition, astrocyte-specific TREM2 knockout mice exhibited much greater brain injury than TREM2 flox/flox controls following AIS, as evidenced by increased cerebral infarct volume, neuronal apoptosis and neurological deficit, which was associated with an increased expression of pro-inflammatory molecule complement component 3 (C3) on reactive astrocytes and activation of microglia/macrophages but decreased expression of S100 calcium binding protein A10 (S100A10) and arginase1 (Arg1) on reactive astrocytes. Mechanistic analyses revealed that astrocytic TREM2 alleviated brain injury by inhibiting detrimental actions of reactive astrocytes but promoting their neuro- and glioprotective actions via the kruppel-like transcription factor-4-nuclear factor-κB axis. Together, this study provides novel evidence for a critical protective role of astrocyte-derived TREM2 in AIS and highlights a potential therapeutic target for the treatment of AIS.
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Affiliation(s)
- Cong Wang
- Department of Neurology and Institute of Neurology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, People's Republic of China
- The Graduate School, Ningxia Medical University, Yinchuan, Ningxia, People's Republic of China
| | - Jing Dong
- Department of Pharmacy, Gongli Hospital, Pudong New Area, Shanghai, Shanghai, People's Republic of China
| | - Heng Huang
- Department of Neurology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, People's Republic of China
| | - Kegui Zhou
- The Graduate School, Ningxia Medical University, Yinchuan, Ningxia, People's Republic of China
| | - Zhenguo Liu
- Department of Neurology, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, People's Republic of China
| | - Richard Milner
- San Diego Biomedical Research Institute, San Diego, California, USA
| | - Longxuan Li
- Department of Neurology and Institute of Neurology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, People's Republic of China
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3
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Hamblin MH, Boese AC, Murad R, Lee JP. MMP-3 Knockout Induces Global Transcriptional Changes and Reduces Cerebral Infarction in Both Male and Female Models of Ischemic Stroke. Int J Mol Sci 2024; 25:7383. [PMID: 39000490 PMCID: PMC11242542 DOI: 10.3390/ijms25137383] [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: 06/01/2024] [Revised: 06/25/2024] [Accepted: 06/25/2024] [Indexed: 07/16/2024] Open
Abstract
Ischemic stroke followed by reperfusion (IR) leads to extensive cerebrovascular injury characterized by neuroinflammation and brain cell death. Inhibition of matrix metalloproteinase-3 (MMP-3) emerges as a promising therapeutic approach to mitigate IR-induced stroke injury. We employed middle cerebral artery occlusion with subsequent reperfusion (MCAO/R) to model ischemic stroke in adult mice. Specifically, we investigated the impact of MMP-3 knockout (KO) on stroke pathophysiology using RNA sequencing (RNA-seq) of stroke brains harvested 48 h post-MCAO. MMP-3 KO significantly reduced brain infarct size following stroke. Notably, RNA-seq analysis showed that MMP-3 KO altered expression of 333 genes (252 downregulated) in male stroke brains and 3768 genes (889 downregulated) in female stroke brains. Functional pathway analysis revealed that inflammation, integrin cell surface signaling, endothelial- and epithelial-mesenchymal transition (EndMT/EMT), and apoptosis gene signatures were decreased in MMP-3 KO stroke brains. Intriguingly, MMP-3 KO downregulated gene signatures more profoundly in females than in males, as indicated by greater negative enrichment scores. Our study underscores MMP-3 inhibition as a promising therapeutic strategy, impacting multiple cellular pathways following stroke.
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Affiliation(s)
- Milton H. Hamblin
- Division of Biomedical Sciences, School of Medicine, University of California, Riverside, Riverside, CA 92521, USA
- Health Sciences Center, Tulane University, New Orleans, LA 70112, USA
| | - Austin C. Boese
- School of Medicine, Emory University, Atlanta, GA 30322, USA;
| | - Rabi Murad
- Bioinformatics, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA 92037, USA;
| | - Jean-Pyo Lee
- Division of Biomedical Sciences, School of Medicine, University of California, Riverside, Riverside, CA 92521, USA
- Department of Physiology, Tulane University School of Medicine, New Orleans, LA 70112, USA
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4
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Sapkota A, Halder SK, Milner R. Cerebral arterioles express the laminin subunits α4 and α5 in conjunction with α6β4 integrin, but strongly downregulate laminin α4 during hypoxia-induced arteriogenic remodeling. Microvasc Res 2024; 152:104625. [PMID: 37979909 PMCID: PMC10872476 DOI: 10.1016/j.mvr.2023.104625] [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: 07/11/2023] [Revised: 10/20/2023] [Accepted: 11/01/2023] [Indexed: 11/20/2023]
Abstract
Previous studies have shown that expression of the endothelial laminin receptor α6β4 integrin in the brain is uniquely restricted to arterioles. As exposure to chronic mild hypoxia (CMH, 8 % O2) stimulates robust angiogenic and arteriogenic remodeling responses in the brain, the goal of this study was to determine how CMH influences cerebrovascular expression of the β4 integrin as well as its potential ligands, laminin 411 and 511, containing the α4 and α5 laminin subunits respectively, and then define how aging impacts this expression. We observed the following: (i) CMH launched a robust arteriogenic remodeling response both in the young (10 weeks) and aged (20 months) brain, correlating with an increased number of β4 integrin+ vessels, (ii) while the laminin α4 subunit is expressed evenly across all cerebral blood vessels, laminin α5 was highly expressed preferentially on β4 integrin+ arterioles, (iii) CMH-induced arteriolar remodeling was associated with strong downregulation of the laminin α4 subunit but no change in the laminin α5 subunit, (iv) in addition to its expression on arterioles, β4 integrin was also expressed at lower levels on capillaries specifically in white matter (WM) tracts but not in the grey matter (GM), and (v), these observations were consistent in both the brain and spinal cord, and age had no obvious impact. Taken together, our findings suggest that laminin 511 may be a specific ligand for α6β4 integrin and that dynamic switching of the laminin subunits α4 and α5 might play an instructive role in arteriogenic remodeling. Furthermore, β4 integrin expression differentiates WM from GM capillaries, highlighting a novel and important difference.
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Affiliation(s)
- Arjun Sapkota
- San Diego Biomedical Research Institute, 3525 John Hopkins Court, Suite 200, San Diego, CA 92121, USA
| | - Sebok K Halder
- San Diego Biomedical Research Institute, 3525 John Hopkins Court, Suite 200, San Diego, CA 92121, USA
| | - Richard Milner
- San Diego Biomedical Research Institute, 3525 John Hopkins Court, Suite 200, San Diego, CA 92121, USA.
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Shaheryar ZA, Khan MA, Hameed H, Mushtaq MN, Muhammad S, Shazly GA, Irfan A, Jardan YAB. Natural Fatty Acid Guards against Brain Endothelial Cell Death and Microvascular Pathology following Ischemic Insult in the Presence of Acute Hyperglycemia. Biomedicines 2023; 11:3342. [PMID: 38137563 PMCID: PMC10742291 DOI: 10.3390/biomedicines11123342] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2023] [Revised: 12/11/2023] [Accepted: 12/12/2023] [Indexed: 12/24/2023] Open
Abstract
Ischemic stroke is worsened by the presence of sudden high blood sugar levels, even in individuals without pre-existing diabetes. This elevated glucose concentration hampers the ability of energy-starved brain cells to efficiently use it as a source of energy. Consequently, this leads to the production of abundant amounts of toxic glucose metabolites, which trigger oxidative stress in the brain milieu, particularly in the microvasculature of the brain. A prominent feature of this oxidative stress is the demise of endothelial cells, causing detrimental changes in blood vessels, including a reduction in their vascular diameter, a decreased efficiency of vessel proliferation, and the impaired integrity of tight junctions. These vascular pathologies contributed to an increase in the volume of damaged tissues (infarct), an exacerbation of brain swelling (edema), and a decline in cognitive and motor functions. In a mouse model of ischemic stroke with induced acute hyperglycemia, a naturally occurring saturated fatty acid provides protective cover to the microvasculature by preventing damage related to oxidative stress. Our current research revealed that lauric acid (LA) attenuated infarct volume and reduced brain edema by reducing endothelial cell death, enhancing vessels' diameter, promoting vascular angiogenesis, and stabilizing barrier functions. Animals administered with this natural compound showed a significant reduction in 4-HNE-positive vessels. In conclusion, natural saturated fatty acids help to preserve brain microvascular functions following ischemic insults in the presence of acute hyperglycemia.
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Affiliation(s)
| | - Mahtab Ahmad Khan
- Faculty of Pharmaceutical Sciences, University of Central Punjab (UCP), Lahore 54000, Pakistan
| | - Huma Hameed
- Faculty of Pharmaceutical Sciences, University of Central Punjab (UCP), Lahore 54000, Pakistan
| | | | - Sajjad Muhammad
- Department of Neurosurgery, University of Helsinki and Helsinki University Hospital, FI-00029 Helsinki, Finland
- Department of Neurosurgery, Medical Faculty, Heinrich Heine University, Moorenstrasse-5, 40225 Düsseldorf, Germany
| | - Gamal A. Shazly
- Department of Pharmaceutics, College of Pharmacy, King Saud University, Riyadh 11451, Saudi Arabia
| | - Ali Irfan
- Department of Chemistry, Government College University Faisalabad, Faisalabad 38000, Pakistan;
| | - Yousef A. Bin Jardan
- Department of Pharmaceutics, College of Pharmacy, King Saud University, Riyadh 11451, Saudi Arabia
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6
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Halder SK, Sapkota A, Milner R. The importance of laminin at the blood-brain barrier. Neural Regen Res 2023; 18:2557-2563. [PMID: 37449589 DOI: 10.4103/1673-5374.373677] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/18/2023] Open
Abstract
The blood-brain barrier is a unique property of central nervous system blood vessels that protects sensitive central nervous system cells from potentially harmful blood components. The mechanistic basis of this barrier is found at multiple levels, including the adherens and tight junction proteins that tightly bind adjacent endothelial cells and the influence of neighboring pericytes, microglia, and astrocyte endfeet. In addition, extracellular matrix components of the vascular basement membrane play a critical role in establishing and maintaining blood-brain barrier integrity, not only by providing an adhesive substrate for blood-brain barrier cells to adhere to, but also by providing guidance cues that strongly influence vascular cell behavior. The extracellular matrix protein laminin is one of the most abundant components of the basement membrane, and several lines of evidence suggest that it plays a key role in directing blood-brain barrier behavior. In this review, we describe the basic structure of laminin and its receptors, the expression patterns of these molecules in central nervous system blood vessels and how they are altered in disease states, and most importantly, how genetic deletion of different laminin isoforms or their receptors reveals the contribution of these molecules to blood-brain barrier function and integrity. Finally, we discuss some of the important unanswered questions in the field and provide a "to-do" list of some of the critical outstanding experiments.
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Affiliation(s)
- Sebok K Halder
- San Diego Biomedical Research Institute, San Diego, CA, USA
| | - Arjun Sapkota
- San Diego Biomedical Research Institute, San Diego, CA, USA
| | - Richard Milner
- San Diego Biomedical Research Institute, San Diego, CA, USA
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7
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Halder SK, Delorme-Walker VD, Milner R. β1 integrin is essential for blood-brain barrier integrity under stable and vascular remodelling conditions; effects differ with age. Fluids Barriers CNS 2023; 20:52. [PMID: 37400852 DOI: 10.1186/s12987-023-00453-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2022] [Accepted: 06/14/2023] [Indexed: 07/05/2023] Open
Abstract
BACKGROUND Maintaining a tight blood-brain barrier (BBB) is an important prerequisite for the preservation of neurological health, though current evidence suggests it declines with age. While extracellular matrix-integrin interactions play critical roles in regulating the balance between vascular stability and remodeling, it remains to be established whether manipulation of integrin function weakens or strengthens vascular integrity. Indeed, recent reports have generated conflicting outcomes in this regard. METHODS Here, in young (8-10 weeks) and aged (20 months) mice, we examined the impact of intraperitoneal injection of a function-blocking β1 integrin antibody, both under normoxic conditions, when the BBB is stable, and during chronic mild hypoxic (CMH; 8% O2) conditions, when a vigorous vascular remodeling response is ongoing. Brain tissue was examined by immunofluorescence (IF) for markers of vascular remodeling and BBB disruption, and microglial activation and proliferation. Data were analyzed using one-way analysis of variance (ANOVA) followed by Tukey's multiple comparison post-hoc test. RESULTS In both young and aged mice, β1 integrin block greatly amplified hypoxia-induced vascular disruption, though it was much less under normoxic conditions. Interestingly, under both normoxic and hypoxic conditions, β1 integrin antibody-induced BBB disruption was greater in young mice. Enhanced BBB breakdown was associated with increased levels of the leaky BBB marker MECA-32 and with greater loss of endothelial tight junction proteins and the adherens protein VE-cadherin. Surprisingly, β1 integrin blockade did not reduce hypoxia-induced endothelial proliferation, nor did it prevent the hypoxia-associated increase in vascularity. Commensurate with the increased vascular disruption, β1 integrin blockade enhanced microglial activation both in young and aged brain, though the impact was much greater in young brain. In vitro studies revealed that β1 integrin blockade also reduced the integrity of a brain endothelial monolayer and triggered disruptions in tight junction proteins. CONCLUSIONS These data demonstrate that β1 integrin plays an essential role in maintaining BBB integrity, both under stable normoxic conditions and during hypoxia-induced vascular remodeling. As β1 integrin blockade had a greater disruptive effect in young brain, effectively shifting the BBB phenotype of young brain towards that of the aged, we speculate that enhancing β1 integrin function at the aged BBB may hold therapeutic potential by reverting the deteriorating BBB phenotype back towards that of the young.
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Affiliation(s)
- Sebok K Halder
- San Diego Biomedical Research Institute, 3525 John Hopkins Court, Suite 200, San Diego, CA, 92121, USA
| | - Violaine D Delorme-Walker
- San Diego Biomedical Research Institute, 3525 John Hopkins Court, Suite 200, San Diego, CA, 92121, USA
| | - Richard Milner
- San Diego Biomedical Research Institute, 3525 John Hopkins Court, Suite 200, San Diego, CA, 92121, USA.
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8
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Thapa K, Shivam K, Khan H, Kaur A, Dua K, Singh S, Singh TG. Emerging Targets for Modulation of Immune Response and Inflammation in Stroke. Neurochem Res 2023; 48:1663-1690. [PMID: 36763312 DOI: 10.1007/s11064-023-03875-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Revised: 01/18/2023] [Accepted: 01/24/2023] [Indexed: 02/11/2023]
Abstract
The inflammatory and immunological responses play a significant role after stroke. The innate immune activation stimulated by microglia during stroke results in the migration of macrophages and lymphocytes into the brain and are responsible for tissue damage. The immune response and inflammation following stroke have no defined targets, and the intricacies of the immunological and inflammatory processes are only partially understood. Innate immune cells enter the brain and meninges during the acute phase, which can cause ischemia damage. Activation of systemic immunity is caused by danger signals sent into the bloodstream by injured brain cells, which is followed by a significant immunodepression that encourages life-threatening infections. Neuropsychiatric sequelae, a major source of post-stroke morbidity, may be induced by an adaptive immune response that is initiated by antigen presentation during the chronic period and is directed against the brain. Thus, the current review discusses the role of immune response and inflammation in stroke pathogenesis, their role in the progression of injury during the stroke, and the emerging targets for the modulation of the mechanism of immune response and inflammation that may have possible therapeutic benefits against stroke.
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Affiliation(s)
- Komal Thapa
- Chitkara College of Pharmacy, Chitkara University, Rajpura, Punjab, 140401, India.,School of Pharmacy, Chitkara University, Rajpura, Himachal Pradesh, 174103, India
| | - Kumar Shivam
- Chitkara College of Pharmacy, Chitkara University, Rajpura, Punjab, 140401, India
| | - Heena Khan
- Chitkara College of Pharmacy, Chitkara University, Rajpura, Punjab, 140401, India
| | - Amarjot Kaur
- Chitkara College of Pharmacy, Chitkara University, Rajpura, Punjab, 140401, India
| | - Kamal Dua
- Discipline of Pharmacy, Graduate School of Health, University of Technology Sydney, Sydney, NSW, 2007, Australia.,Faculty of Health, Australian Research Centre in Complementary & Integrative Medicine, University of Technology Sydney, Ultimo, 2007, Australia
| | - Sachin Singh
- School of Pharmaceutical Sciences, Lovely Professional University, Jalandhar - Delhi G.T. Road, Phagwara, Punjab, 144411, India
| | - Thakur Gurjeet Singh
- Chitkara College of Pharmacy, Chitkara University, Rajpura, Punjab, 140401, India.
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Halder SK, Milner R. Exaggerated hypoxic vascular breakdown in aged brain due to reduced microglial vasculo-protection. Aging Cell 2022; 21:e13720. [PMID: 36130175 PMCID: PMC9649604 DOI: 10.1111/acel.13720] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Revised: 08/04/2022] [Accepted: 08/31/2022] [Indexed: 01/25/2023] Open
Abstract
In a recent study of young mice, we showed that chronic mild hypoxia (CMH, 8% O2 ) triggers transient blood-brain barrier (BBB) disruption, and that microglia play an important vasculo-protective function in maintaining BBB integrity. As hypoxia is a common component of many age-related diseases, here we extended these studies to aged mice and found that hypoxia-induced vascular leak was greatly amplified (5-fold to 10-fold) in aged mice, being particularly high in the olfactory bulb and midbrain. While aged mice showed no obvious difference in the early stages of hypoxic angiogenic remodeling, the compensatory increase in vascularity and vessel maturation was significantly delayed. Compared with young brain, microglia in the normoxic aged brain were markedly activated, and this was further increased under hypoxic conditions, but paradoxically, this correlated with reduced vasculo-protection. Microglial depletion studies showed that microglial still play an important vasculo-protective role in aged brain, but interestingly, partial attenuation of microglial activation with minocycline resulted in fewer vascular leaks and reduced loss of endothelial tight junction proteins. Taken together, these findings suggest that increased BBB disruption in hypoxic aged mice can be explained both by a delayed vascular remodeling response and reduced microglial vasculo-protection. Importantly, they show that overly activated microglia in the aged brain are less effective at maintaining vascular integrity, though this can be improved by reducing microglial activation with minocycline, suggesting therapeutic potential for enhancing BBB integrity in the hypoxia-predisposed elderly population.
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Affiliation(s)
- Sebok K. Halder
- San Diego Biomedical Research InstituteSan DiegoCaliforniaUSA
| | - Richard Milner
- San Diego Biomedical Research InstituteSan DiegoCaliforniaUSA
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10
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Nirwane A, Yao Y. Cell-specific expression and function of laminin at the neurovascular unit. J Cereb Blood Flow Metab 2022; 42:1979-1999. [PMID: 35796497 PMCID: PMC9580165 DOI: 10.1177/0271678x221113027] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Revised: 06/08/2022] [Accepted: 06/19/2022] [Indexed: 11/17/2022]
Abstract
Laminin, a major component of the basal lamina (BL), is a heterotrimeric protein with many isoforms. In the CNS, laminin is expressed by almost all cell types, yet different cells synthesize distinct laminin isoforms. By binding to its receptors, laminin exerts a wide variety of important functions. However, due to the reciprocal and cell-specific expression of laminin in different cells at the neurovascular unit, its functions in blood-brain barrier (BBB) maintenance and BBB repair after injury are not fully understood. In this review, we focus on the expression and functions of laminin and its receptors in the neurovascular unit under both physiological and pathological conditions. We first briefly introduce the structures of laminin and its receptors. Next, the expression and functions of laminin and its receptors in the CNS are summarized in a cell-specific manner. Finally, we identify the knowledge gap in the field and discuss key questions that need to be answered in the future. Our goal is to provide a comprehensive overview on cell-specific expression of laminin and its receptors in the CNS and their functions on BBB integrity.
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Affiliation(s)
- Abhijit Nirwane
- Department of Molecular Pharmacology and Physiology, Morsani College of Medicine, University of South Florida, Tampa, FL, USA
| | - Yao Yao
- Department of Molecular Pharmacology and Physiology, Morsani College of Medicine, University of South Florida, Tampa, FL, USA
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11
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Cegarra C, Cameron B, Chaves C, Dabdoubi T, Do TM, Genêt B, Roudières V, Shi Y, Tchepikoff P, Lesuisse D. An innovative strategy to identify new targets for delivering antibodies to the brain has led to the exploration of the integrin family. PLoS One 2022; 17:e0274667. [PMID: 36108060 PMCID: PMC9477330 DOI: 10.1371/journal.pone.0274667] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2022] [Accepted: 09/01/2022] [Indexed: 11/19/2022] Open
Abstract
Background
Increasing brain exposure of biotherapeutics is key to success in central nervous system disease drug discovery. Accessing the brain parenchyma is especially difficult for large polar molecules such as biotherapeutics and antibodies because of the blood-brain barrier. We investigated a new immunization strategy to identify novel receptors mediating transcytosis across the blood-brain barrier.
Method
We immunized mice with primary non-human primate brain microvascular endothelial cells to obtain antibodies. These antibodies were screened for their capacity to bind and to be internalized by primary non-human primate brain microvascular endothelial cells and Human Cerebral Microvascular Endothelial Cell clone D3. They were further evaluated for their transcytosis capabilities in three in vitro blood-brain barrier models. In parallel, their targets were identified by two different methods and their pattern of binding to human tissue was investigated using immunohistochemistry.
Results
12 antibodies with unique sequence and internalization capacities were selected amongst more than six hundred. Aside from one antibody targeting Activated Leukocyte Cell Adhesion Molecule and one targeting Striatin3, most of the other antibodies recognized β1 integrin and its heterodimers. The antibody with the best transcytosis capabilities in all blood-brain barrier in vitro models and with the best binding capacity was an anti-αnβ1 integrin. In comparison, commercial anti-integrin antibodies performed poorly in transcytosis assays, emphasizing the originality of the antibodies derived here. Immunohistochemistry studies showed specific vascular staining on human and non-human primate tissues.
Conclusions
This transcytotic behavior has not previously been reported for anti-integrin antibodies. Further studies should be undertaken to validate this new mechanism in vivo and to evaluate its potential in brain delivery.
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Affiliation(s)
- Céline Cegarra
- Rare and Neurologic Diseases Research Therapeutic Area, Sanofi, Chilly Mazarin, France
- * E-mail:
| | | | - Catarina Chaves
- Rare and Neurologic Diseases Research Therapeutic Area, Sanofi, Chilly Mazarin, France
| | | | - Tuan-Minh Do
- Rare and Neurologic Diseases Research Therapeutic Area, Sanofi, Chilly Mazarin, France
| | - Bruno Genêt
- Integrated Drug Discovery, Sanofi, Vitry-Sur-Seine, France
| | - Valérie Roudières
- Rare and Neurologic Diseases Research Therapeutic Area, Sanofi, Chilly Mazarin, France
| | - Yi Shi
- Histology, Translational Sciences, Sanofi, Vitry-Sur-Seine, France
| | | | - Dominique Lesuisse
- Rare and Neurologic Diseases Research Therapeutic Area, Sanofi, Chilly Mazarin, France
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12
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Halder SK, Sapkota A, Milner R. The impact of genetic manipulation of laminin and integrins at the blood-brain barrier. Fluids Barriers CNS 2022; 19:50. [PMID: 35690759 PMCID: PMC9188059 DOI: 10.1186/s12987-022-00346-8] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2022] [Accepted: 05/18/2022] [Indexed: 12/26/2022] Open
Abstract
Blood vessels in the central nervous system (CNS) are unique in having high electrical resistance and low permeability, which creates a selective barrier protecting sensitive neural cells within the CNS from potentially harmful components in the blood. The molecular basis of this blood–brain barrier (BBB) is found at the level of endothelial adherens and tight junction protein complexes, extracellular matrix (ECM) components of the vascular basement membrane (BM), and the influence of adjacent pericytes and astrocyte endfeet. Current evidence supports the concept that instructive cues from the BBB ECM are not only important for the development and maturation of CNS blood vessels, but they are also essential for the maintenance of vascular stability and BBB integrity. In this review, we examine the contributions of one of the most abundant ECM proteins, laminin to BBB integrity, and summarize how genetic deletions of different laminin isoforms or their integrin receptors impact BBB development, maturation, and stability.
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Affiliation(s)
- Sebok K Halder
- San Diego Biomedical Research Institute, 3525 John Hopkins Court, Suite 200, San Diego, CA, 92121, USA
| | - Arjun Sapkota
- San Diego Biomedical Research Institute, 3525 John Hopkins Court, Suite 200, San Diego, CA, 92121, USA
| | - Richard Milner
- San Diego Biomedical Research Institute, 3525 John Hopkins Court, Suite 200, San Diego, CA, 92121, USA.
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Hamblin MH, Murad R, Yin J, Vallim G, Lee JP. Modulation of gene expression on a transcriptome-wide level following human neural stem cell transplantation in aged mouse stroke brains. Exp Neurol 2022; 347:113913. [PMID: 34752785 PMCID: PMC8647207 DOI: 10.1016/j.expneurol.2021.113913] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2021] [Revised: 10/29/2021] [Accepted: 11/01/2021] [Indexed: 01/19/2023]
Abstract
INTRODUCTION Neural stem cell (NSC) transplantation offers great potential for treating ischemic stroke. Clinically, ischemia followed by reperfusion results in robust cerebrovascular injury that upregulates proinflammatory factors, disrupts neurovascular units, and causes brain cell death. NSCs possess multiple actions that can be exploited for reducing the severity of neurovascular injury. Our previous studies in young adult mice showed that human NSC transplantation during the subacute stage diminishes stroke pathophysiology and improves behavioral outcome. METHODS We employed a well-established and commonly used stroke model, middle cerebral artery occlusion with subsequent reperfusion (MCAO/R). Here, we assessed the outcomes of hNSC transplantation 48 h post-MCAO (24 h post-transplant) in aged mouse brains in response to stroke because aging is a crucial risk factor for cerebral ischemia. Next, we tested whether administration of the integrin α5β1 inhibitor, ATN-161, prior to hNSC transplantation further affects stoke outcome as compared with NSCs alone. RNA sequencing (RNA-seq) was used to assess the impact of hNSC transplantation on differentially expressed genes (DEGs) on a transcriptome-wide level. RESULTS Here, we report that hNSC-engrafted brains with or without ATN-161 showed significantly reduced infarct size, and attenuated the induction of proinflammatory factors and matrix metalloproteases. RNA-seq analysis revealed DEGs and molecular pathways by which hNSCs induce a beneficial post-stroke outcome in aged stroke brains. 811 genes were differentially expressed (651 downregulated and 160 upregulated) in hNSC-engrafted stroke brains. Functional pathway analysis identified enriched and depleted pathways in hNSC-engrafted aged mouse stroke brains. Depletion of pathways following hNSC-engraftment included signaling involving neuroinflammation, acute phase response, leukocyte extravasation, and phagosome formation. On the other hand, enrichment of pathways in hNSC-engrafted brains was associated with PPAR signaling, LXR/RXR activation, and inhibition of matrix metalloproteases. Hierarchical cluster analysis of DEGs in hNSC-engrafted brains indicate decreased expression of genes encoding TNF receptors, proinflammatory factors, apoptosis factors, adhesion and leukocyte extravasation, and Toll-like receptors. CONCLUSIONS Our study is the first to show global transcripts differentially expressed following hNSC transplantation in the subacute phase of stroke in aged mice. The outcome of our transcriptome study would be useful to develop new therapies ameliorating early-stage stroke injury.
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Affiliation(s)
- Milton H Hamblin
- Tulane University Health Sciences Center, Tulane University, New Orleans, LA 70112, USA.
| | - Rabi Murad
- Bioinformatics, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA 92037, USA
| | - Jun Yin
- Bioinformatics, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA 92037, USA
| | - Gustavo Vallim
- Department of Physiology, Tulane University School of Medicine, New Orleans, LA 70112, USA
| | - Jean-Pyo Lee
- Department of Physiology, Tulane University School of Medicine, New Orleans, LA 70112, USA.
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14
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Silencing of lncRNA XIST impairs angiogenesis and exacerbates cerebral vascular injury after ischemic stroke. MOLECULAR THERAPY. NUCLEIC ACIDS 2021; 26:148-160. [PMID: 34513301 PMCID: PMC8413678 DOI: 10.1016/j.omtn.2021.06.025] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Accepted: 06/30/2021] [Indexed: 11/22/2022]
Abstract
The aim of this study was to investigate the function and regulatory mechanism of long non-coding RNA (lncRNA) X-inactive-specific transcript (XIST) in cerebral ischemic stroke (CIS). The impact of lncRNA XIST on CIS was evaluated in acute CIS patients, middle cerebral artery occlusion (MCAO) mice, and oxygen-glucose deprivation and restoration brain endothelial cells. Our results demonstrated that the expression of lncRNA XIST decreased during the early stages of CIS but then increased in the later stages in CIS patients and ischemic models in vivo and in vitro. In addition, the serum levels of lncRNA XIST negatively correlated with severity of neurological impairment of CIS patients. Further studies exhibited that lncRNA XIST regulated the expression of proangiogenic factor-integrin α5 (Itgα5) and anti-inflammation factor-Kruppel-like transcription factor 4 (KLF4) by targeting microRNA-92a (miR-92a). Silencing of lncRNA XIST impaired angiogenesis and exacerbated cerebral vascular injury following CIS, leading to larger infarcts and worse neurological deficits in transient MCAO mice. Mechanistic analysis revealed that lncRNA XIST modulated angiogenesis and alleviated cerebral vascular injury following CIS through mediating the miR-92a/Itgα5 or KLF4 axis, respectively. These data indicate that lncRNA XIST confers protection against CIS, providing a valuable target for future prevention and treatment of CIS.
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15
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Amruta N, Bix G. ATN-161 Ameliorates Ischemia/Reperfusion-induced Oxidative Stress, Fibro-inflammation, Mitochondrial damage, and Apoptosis-mediated Tight Junction Disruption in bEnd.3 Cells. Inflammation 2021; 44:2377-2394. [PMID: 34420157 PMCID: PMC8380192 DOI: 10.1007/s10753-021-01509-9] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Revised: 05/25/2021] [Accepted: 06/27/2021] [Indexed: 12/21/2022]
Abstract
We have previously demonstrated the significance of endothelial cell-expressed α5β1 integrin in ischemic stroke, having shown that α5β1 integrin endothelial cell-selective knockout mice are significantly resistance to ischemic stroke injury via preservation of the tight junction protein claudin-5 and subsequent stabilization of the blood–brain barrier (BBB). In addition, inhibition of α5β1 by the small peptide noncompetitive integrin α5 inhibitor, ATN-161, is beneficial in a mouse model of ischemic stroke through reduction of infarct volume, edema, stabilization of the BBB, and reduced inflammation and immune cell infiltration into the brain. In continuation with our previous findings, we have further evaluated the mechanistic role of ATN-161 in vitro and found that oxygen and glucose deprivation and reperfusion (OGD/R)-induced inflammation, oxidative stress, apoptosis, mitochondrial depolarization, and fibrosis attenuate tight junction integrity via induction of α5, NLRP3, p-FAK, and p-AKT signaling in mouse brain endothelial cells. ATN-161 treatment (10 µM) effectively inhibited OGD/R-induced extracellular matrix (ECM) deposition by reducing integrin α5, MMP-9, and fibronectin expression, as well as reducing oxidative stress by reducing mitochondrial superoxide radicals, intracellular ROS, inflammation by reducing NLRP3 inflammasome, tight junction loss by reducing claudin-5 and ZO-1 expression levels, mitochondrial damage by inhibiting mitochondrial depolarization, and apoptosis via regulation of p-FAK and p-AKT levels. Taken together, our results further support therapeutically targeting α5 integrin with ATN-161, a safe, well-tolerated, and clinically validated peptide, in ischemic stroke.
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Affiliation(s)
- Narayanappa Amruta
- Department of Neurosurgery, Clinical Neuroscience Research Center, Tulane University School of Medicine, Room 1349, 131 S. Robertson, Ste 1300, New Orleans, LA, 70112, USA
| | - Gregory Bix
- Department of Neurosurgery, Clinical Neuroscience Research Center, Tulane University School of Medicine, Room 1349, 131 S. Robertson, Ste 1300, New Orleans, LA, 70112, USA. .,Department of Neurology, Tulane University School of Medicine, New Orleans, LA, 70112, USA. .,Tulane Brain Institute, Tulane University, New Orleans, LA, 70112, USA. .,Department of Neurosurgery, Clinical Neuroscience Research Center, Tulane University School of Medicine, Room 1349, 131 S. Robertson, Ste 1300, New Orleans, LA, 70112, USA.
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16
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Targeting RGD-binding integrins as an integrative therapy for diabetic retinopathy and neovascular age-related macular degeneration. Prog Retin Eye Res 2021; 85:100966. [PMID: 33775825 DOI: 10.1016/j.preteyeres.2021.100966] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2021] [Revised: 03/15/2021] [Accepted: 03/19/2021] [Indexed: 12/14/2022]
Abstract
Integrins are a class of transmembrane receptors that are involved in a wide range of biological functions. Dysregulation of integrins has been implicated in many pathological processes and consequently, they are attractive therapeutic targets. In the ophthalmology arena, there is extensive evidence suggesting that integrins play an important role in diabetic retinopathy (DR), age-related macular degeneration (AMD), glaucoma, dry eye disease and retinal vein occlusion. For example, there is extensive evidence that arginyl-glycyl-aspartic acid (Arg-Gly-Asp; RGD)-binding integrins are involved in key disease hallmarks of DR and neovascular AMD (nvAMD), specifically inflammation, vascular leakage, angiogenesis and fibrosis. Based on such evidence, drugs that engage integrin-linked pathways have received attention for their potential to block all these vision-threatening pathways. This review focuses on the pathophysiological role that RGD-binding integrins can have in complex multifactorial retinal disorders like DR, diabetic macular edema (DME) and nvAMD, which are leading causes of blindness in developed countries. Special emphasis will be given on how RGD-binding integrins can modulate the intricate molecular pathways and regulate the underlying pathological mechanisms. For instance, the interplay between integrins and key molecular players such as growth factors, cytokines and enzymes will be summarized. In addition, recent clinical advances linked to targeting RGD-binding integrins in the context of DME and nvAMD will be discussed alongside future potential for limiting progression of these diseases.
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17
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Amruta N, Chastain WH, Paz M, Solch RJ, Murray-Brown IC, Befeler JB, Gressett TE, Longo MT, Engler-Chiurazzi EB, Bix G. SARS-CoV-2 mediated neuroinflammation and the impact of COVID-19 in neurological disorders. Cytokine Growth Factor Rev 2021; 58:1-15. [PMID: 33674185 PMCID: PMC7894219 DOI: 10.1016/j.cytogfr.2021.02.002] [Citation(s) in RCA: 71] [Impact Index Per Article: 23.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Accepted: 02/16/2021] [Indexed: 12/11/2022]
Abstract
SARS-CoV-2 is a novel coronavirus that severely affects the respiratory system, is the cause of the COVID-19 pandemic, and is projected to result in the deaths of 2 million people worldwide. Recent reports suggest that SARS-CoV-2 also affects the central nervous system along with other organs. COVID-19-associated complications are observed in older people with underlying neurological conditions like stroke, Alzheimer's disease, and Parkinson's disease. Hence, we discuss SARS-CoV-2 viral replication and its inflammation-mediated infection. This review also focuses on COVID-19 associated neurological complications in individuals with those complications as well as other groups of people. Finally, we also briefly discuss the current therapies available to treat patients, as well as ongoing available treatments and vaccines for effective cures with a special focus on the therapeutic potential of a small 5 amino acid peptide (PHSCN), ATN-161, that inhibits SARS-CoV-2 spike protein binding to both integrin α5β1 and α5β1/hACE2.
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Affiliation(s)
- Narayanappa Amruta
- Department of Neurosurgery, Clinical Neuroscience Research Center, Tulane University School of Medicine, New Orleans, LA, 70112, USA
| | - Wesley H Chastain
- Department of Neurosurgery, Clinical Neuroscience Research Center, Tulane University School of Medicine, New Orleans, LA, 70112, USA
| | - Meshi Paz
- Department of Neurosurgery, Clinical Neuroscience Research Center, Tulane University School of Medicine, New Orleans, LA, 70112, USA
| | - Rebecca J Solch
- Department of Neurology, Tulane University School of Medicine, New Orleans, LA, 70112, USA
| | - Isabel C Murray-Brown
- Department of Neurosurgery, Clinical Neuroscience Research Center, Tulane University School of Medicine, New Orleans, LA, 70112, USA
| | - Jaime B Befeler
- Department of Neurosurgery, Clinical Neuroscience Research Center, Tulane University School of Medicine, New Orleans, LA, 70112, USA
| | - Timothy E Gressett
- Department of Neurosurgery, Clinical Neuroscience Research Center, Tulane University School of Medicine, New Orleans, LA, 70112, USA
| | - Michele T Longo
- Department of Neurology, Tulane University School of Medicine, New Orleans, LA, 70112, USA; Tulane Brain Institute, Tulane University, New Orleans, LA, 70112, USA
| | - Elizabeth B Engler-Chiurazzi
- Department of Neurosurgery, Clinical Neuroscience Research Center, Tulane University School of Medicine, New Orleans, LA, 70112, USA; Tulane Brain Institute, Tulane University, New Orleans, LA, 70112, USA
| | - Gregory Bix
- Department of Neurosurgery, Clinical Neuroscience Research Center, Tulane University School of Medicine, New Orleans, LA, 70112, USA; Department of Neurology, Tulane University School of Medicine, New Orleans, LA, 70112, USA; Tulane Brain Institute, Tulane University, New Orleans, LA, 70112, USA.
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18
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Al-Ahmad AJ, Pervaiz I, Karamyan VT. Neurolysin substrates bradykinin, neurotensin and substance P enhance brain microvascular permeability in a human in vitro model. J Neuroendocrinol 2021; 33:e12931. [PMID: 33506602 PMCID: PMC8166215 DOI: 10.1111/jne.12931] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Revised: 12/09/2020] [Accepted: 12/10/2020] [Indexed: 12/31/2022]
Abstract
Increased brain microvascular permeability and disruption of blood-brain barrier (BBB) function are among hallmarks of several acute neurodegenerative disorders, including stroke. Numerous studies suggest the involvement of bradykinin (BK), neurotensin (NT) and substance P (SP) in BBB impairment and oedema formation after stroke; however, there is paucity of data in regard to the direct effects of these peptides on the brain microvascular endothelial cells (BMECs) and BBB. The present study aimed to evaluate the direct effects of BK, NT and SP on the permeability of BBB in an in vitro model based on human induced pluripotent stem cell (iPSC)-derived BMECs. Our data indicate that all three peptides increase BBB permeability in a concentration-dependent manner in an in vitro model formed from two different iPSC lines (CTR90F and CTR65M) and widely used hCMEC/D3 human BMECs. The combination of BK, NT and SP at a sub-effective concentration also resulted in increased BBB permeability in the iPSC-derived model indicating potentiation of their action. Furthermore, we observed abrogation of BK, NT and SP effects with pretreatment of pharmacological blockers targeting their specific receptors. Additional mechanistic studies indicate that the short-term effects of these peptides are not mediated through alteration of tight-junction proteins claudin-5 and occludin, but likely involve redistribution of F-actin and secretion of vascular endothelial growth factor. This is the first experimental study to document the increased permeability of the BBB in response to direct action of NT in an in vitro model. In addition, our study confirms the expected but not well-documented, direct effect of SP on BBB permeability and adds to the well-recognised actions of BK on BBB. Lastly, we demonstrate that peptidase neurolysin can neutralise the effects of these peptides on BBB, suggesting potential therapeutic implications.
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Affiliation(s)
- Abraham J Al-Ahmad
- Department of Pharmaceutical Sciences and Center for Blood Brain Barrier Research, School of Pharmacy, TTUHSC, Amarillo, TX, USA
| | - Iqra Pervaiz
- Department of Pharmaceutical Sciences and Center for Blood Brain Barrier Research, School of Pharmacy, TTUHSC, Amarillo, TX, USA
| | - Vardan T Karamyan
- Department of Pharmaceutical Sciences and Center for Blood Brain Barrier Research, School of Pharmacy, TTUHSC, Amarillo, TX, USA
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19
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Halder SK, Milner R. Mild hypoxia triggers transient blood-brain barrier disruption: a fundamental protective role for microglia. Acta Neuropathol Commun 2020; 8:175. [PMID: 33115539 PMCID: PMC7592567 DOI: 10.1186/s40478-020-01051-z] [Citation(s) in RCA: 50] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Accepted: 10/02/2020] [Indexed: 12/11/2022] Open
Abstract
We recently demonstrated that when mice are exposed to chronic mild hypoxia (CMH, 8% O2), blood vessels in the spinal cord show transient vascular leak that is associated with clustering and activation of microglia around disrupted vessels. Importantly, microglial depletion profoundly increased hypoxia-induced vascular leak, implying that microglia play a critical role maintaining vascular integrity in the hypoxic spinal cord. The goal of the current study was to examine if microglia play a similar vasculo-protective function in the brain. Employing extravascular fibrinogen leak as an index of blood-brain barrier (BBB) disruption, we found that CMH provoked transient vascular leak in cerebral blood vessels that was associated with activation and aggregation of Mac-1-positive microglia around leaky vessels. Interestingly, CMH-induced vascular leak showed regional selectivity, being much more prevalent in the brainstem and olfactory bulb than the cerebral cortex and cerebellum. Pharmacological depletion of microglia with the colony stimulating factor-1 receptor inhibitor PLX5622, had no effect under normoxic conditions, but markedly increased hypoxia-induced cerebrovascular leak in all regions examined. As in the spinal cord, this was associated with endothelial induction of MECA-32, a marker of leaky CNS endothelium, and greater loss of endothelial tight junction proteins. Brain regions displaying the highest levels of hypoxic-induced vascular leak also showed the greatest levels of angiogenic remodeling, suggesting that transient BBB disruption may be an unwanted side-effect of hypoxic-induced angiogenic remodeling. As hypoxia is common to a multitude of human diseases including obstructive sleep apnea, lung disease, and age-related pulmonary, cardiac and cerebrovascular dysfunction, our findings have important translational implications. First, they point to a potential pathogenic role of chronic hypoxia in triggering BBB disruption and subsequent neurological dysfunction, and second, they demonstrate an important protective role for microglia in maintaining vascular integrity in the hypoxic brain.
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Affiliation(s)
- Sebok K. Halder
- San Diego Biomedical Research Institute, 10865 Road to the Cure, Suite 100, San Diego, CA 92121 USA
| | - Richard Milner
- San Diego Biomedical Research Institute, 10865 Road to the Cure, Suite 100, San Diego, CA 92121 USA
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20
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Bicker J, Alves G, Fonseca C, Falcão A, Fortuna A. Repairing blood-CNS barriers: Future therapeutic approaches for neuropsychiatric disorders. Pharmacol Res 2020; 162:105226. [PMID: 33007420 DOI: 10.1016/j.phrs.2020.105226] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/09/2020] [Revised: 09/21/2020] [Accepted: 09/22/2020] [Indexed: 12/19/2022]
Abstract
Central nervous system (CNS) drug development faces significant difficulties that translate into high rates of failure and lack of innovation. The pathophysiology of neurological and psychiatric disorders often results in the breakdown of blood-CNS barriers, disturbing the CNS microenvironment and worsening disease progression. Therefore, restoring the integrity of blood-CNS barriers may have a beneficial influence in several CNS disorders and improve treatment outcomes. In this review, pathways that may be modulated to protect blood-CNS barriers from neuroinflammatory and oxidative insults are featured. First, the participation of the brain endothelium and glial cells in disruption processes is discussed. Then, the relevance of regulatory systems is analysed, specifically the hypothalamic-pituitary axis, the renin-angiotensin system, sleep and circadian rhythms, and glutamate neurotransmission. Lastly, compounds of endogenous and exogenous origin that are known to mediate the repair of blood-CNS barriers are presented. We believe that enhancing the protection of blood-CNS barriers is a promising therapeutic strategy to pursue in the future.
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Affiliation(s)
- Joana Bicker
- University of Coimbra, Faculty of Pharmacy, Coimbra, Portugal; University of Coimbra, Coimbra Institute for Biomedical Imaging and Translational Research, Coimbra, Portugal.
| | - Gilberto Alves
- CICS-UBI, Health Sciences Research Center, University of Beira Interior, Covilhã, Portugal
| | - Carla Fonseca
- University of Coimbra, Faculty of Pharmacy, Coimbra, Portugal
| | - Amílcar Falcão
- University of Coimbra, Faculty of Pharmacy, Coimbra, Portugal; University of Coimbra, Coimbra Institute for Biomedical Imaging and Translational Research, Coimbra, Portugal
| | - Ana Fortuna
- University of Coimbra, Faculty of Pharmacy, Coimbra, Portugal; University of Coimbra, Coimbra Institute for Biomedical Imaging and Translational Research, Coimbra, Portugal
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21
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Huang Q, Wang X, Lin X, Zhang J, You X, Shao A. The Role of Transient Receptor Potential Channels in Blood-Brain Barrier Dysfunction after Ischemic Stroke. Biomed Pharmacother 2020; 131:110647. [PMID: 32858500 DOI: 10.1016/j.biopha.2020.110647] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2020] [Revised: 08/11/2020] [Accepted: 08/16/2020] [Indexed: 12/25/2022] Open
Abstract
Stroke is the leading cause of long-term disability, demanding an ever-increasing need to find treatment. Transient receptor potential (TRP) channels are nonselective Ca2+-permeable channels, among which TRPC, TRPM, and TRPV are widely expressed in the brain. Dysfunction of the blood brain barrier (BBB) is a core feature of stroke and is associated with severity of injury. As studies have shown, TRP channels influence various neuronal functions by regulating the BBB. Here, we briefly review the role of TRP channel in the BBB dysfunction after stroke, and explore the therapeutic potential of TRP-targeted therapy.
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Affiliation(s)
- Qingxia Huang
- Department of Echocardiography, The Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, China
| | - Xiaoyu Wang
- Department of Neurosurgery, The Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, China
| | - Xianyi Lin
- Department of anesthesiology, Sir run run shaw hospital, school of medicine, zhejiang university, China
| | - Jianmin Zhang
- Department of Neurosurgery, The Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, China; Brain Research Institute, Zhejiang University, Hangzhou, China; Collaborative Innovation Center for Brain Science, Zhejiang University, Hangzhou, China
| | - Xiangdong You
- Department of Echocardiography, The Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, China.
| | - Anwen Shao
- Department of Neurosurgery, The Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, China.
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22
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Grant SM, DeMorrow S. Bile Acid Signaling in Neurodegenerative and Neurological Disorders. Int J Mol Sci 2020; 21:E5982. [PMID: 32825239 PMCID: PMC7503576 DOI: 10.3390/ijms21175982] [Citation(s) in RCA: 80] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Revised: 08/18/2020] [Accepted: 08/19/2020] [Indexed: 12/13/2022] Open
Abstract
Bile acids are commonly known as digestive agents for lipids. The mechanisms of bile acids in the gastrointestinal track during normal physiological conditions as well as hepatic and cholestatic diseases have been well studied. Bile acids additionally serve as ligands for signaling molecules such as nuclear receptor Farnesoid X receptor and membrane-bound receptors, Takeda G-protein-coupled bile acid receptor and sphingosine-1-phosphate receptor 2. Recent studies have shown that bile acid signaling may also have a prevalent role in the central nervous system. Some bile acids, such as tauroursodeoxycholic acid and ursodeoxycholic acid, have shown neuroprotective potential in experimental animal models and clinical studies of many neurological conditions. Alterations in bile acid metabolism have been discovered as potential biomarkers for prognosis tools as well as the expression of various bile acid receptors in multiple neurological ailments. This review explores the findings of recent studies highlighting bile acid-mediated therapies and bile acid-mediated signaling and the roles they play in neurodegenerative and neurological diseases.
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Affiliation(s)
- Stephanie M. Grant
- Division of Pharmacology and Toxicology, College of Pharmacy, The University of Texas at Austin, Austin, TX 78712, USA;
- Department of Internal Medicine, Dell Medical School, The University of Texas at Austin, Austin, TX 78712, USA
| | - Sharon DeMorrow
- Division of Pharmacology and Toxicology, College of Pharmacy, The University of Texas at Austin, Austin, TX 78712, USA;
- Department of Internal Medicine, Dell Medical School, The University of Texas at Austin, Austin, TX 78712, USA
- Research Division, Central Texas Veterans Healthcare System, Austin, TX 78712, USA
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23
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Edwards DN, Salmeron K, Lukins DE, Trout AL, Fraser JF, Bix GJ. Integrin α5β1 inhibition by ATN-161 reduces neuroinflammation and is neuroprotective in ischemic stroke. J Cereb Blood Flow Metab 2020; 40:1695-1708. [PMID: 31575337 PMCID: PMC7370357 DOI: 10.1177/0271678x19880161] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Stroke remains a leading cause of death and disability with limited therapeutic options. Endothelial cell β1 integrin receptors play a direct role in blood-brain barrier (BBB) dysfunction through regulation of tight junction proteins and infiltrating leukocytes, potentially mediated by β1 integrins. Following tandem transient common carotid artery/middle cerebral artery occlusion on wild-type mice, we administered the integrin a5b1 inhibitor, ATN-161, intraperitoneal (IP) injection at 1 mg/kg acutely after reperfusion, on post-stroke day (PSD)1 and PSD2. Systemic changes (heart rate, pulse distension, and body temperature) were determined. Additionally, infarct volume and edema were determined by 2,3-triphenyltetrazolium chloride and magnetic resonance imaging, while neurological changes were evaluated using an 11-point Neuroscore. Brain immunohistochemistry was performed for claudin-5, α5β1, IgG, and CD45 + cells, and quantitative polymerase chain reaction (qPCR) was performed for matrix metalloproteinase-9 (MMP-9), interleukin (IL)-1β, collagen IV, and CXCL12. ATN-161 significantly reduced integrin α5β1 expression in the surrounding peri-infarct region with no systemic changes. Infarct volume, edema, and functional deficit were significantly reduced in ATN-161-treated mice. Furthermore, ATN-161 treatment reduced IgG extravasation into the parenchyma through conserved claudin-5, collagen IV, CXCL12 while reducing MMP-9 transcription. Additionally, IL-1β and CD45 + cells were reduced in the ipsilateral cortex following ATN-161 administration. Collectively, ATN-161 may be a promising novel stroke therapy by reducing post-stroke inflammation and BBB permeability.
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Affiliation(s)
| | - Kathleen Salmeron
- Department of Neuroscience, University of Kentucky, Lexington, USA.,Department of Physiology, University of Kentucky, Lexington, USA
| | | | - Amanda L Trout
- Department of Neurology, University of Kentucky, Lexington, USA
| | - Justin F Fraser
- Department of Neuroscience, University of Kentucky, Lexington, USA.,Department of Radiology, University of Kentucky, Lexington, USA.,Department of Neurology, University of Kentucky, Lexington, USA.,Department of Neurosurgery, University of Kentucky, Lexington, USA.,Center for Advanced Translational Stroke Science, University of Kentucky, Lexington, USA
| | - Gregory J Bix
- Department of Neuroscience, University of Kentucky, Lexington, USA.,Department of Neurology, University of Kentucky, Lexington, USA.,Department of Neurosurgery, University of Kentucky, Lexington, USA.,Center for Advanced Translational Stroke Science, University of Kentucky, Lexington, USA.,Sanders-Brown Center on Aging, University of Kentucky, Lexington, USA
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24
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Amruta N, Rahman AA, Pinteaux E, Bix G. Neuroinflammation and fibrosis in stroke: The good, the bad and the ugly. J Neuroimmunol 2020; 346:577318. [PMID: 32682140 PMCID: PMC7794086 DOI: 10.1016/j.jneuroim.2020.577318] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2020] [Revised: 07/01/2020] [Accepted: 07/03/2020] [Indexed: 02/08/2023]
Abstract
Stroke is the leading cause of death and the main cause of disability in surviving patients. The detrimental interaction between immune cells, glial cells, and matrix components in stroke pathology results in persistent inflammation that progresses to fibrosis. A substantial effort is being directed toward understanding the exact neuroinflammatory events that take place as a result of stroke. The initiation of a potent cytokine response, along with immune cell activation and infiltration in the ischemic core, has massive acute deleterious effects, generally exacerbated by comorbid inflammatory conditions. There is secondary neuroinflammation that promotes further injury, resulting in cell death, but conversely plays a beneficial role, by promoting recovery. This highlights the need for a better understanding of the neuroinflammatory and fibrotic processes, as well as the need to identify new mechanisms and potential modulators. In this review, we summarize several aspects of stroke-induced inflammation, fibrosis, and include a discussion of cytokine inhibitors/inducers, immune cells, and fibro-inflammation signaling inhibitors in order to identify new pharmacological means of intervention.
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Affiliation(s)
- Narayanappa Amruta
- Department of Neurosurgery, Clinical Neuroscience Research Center, Tulane University School of Medicine, New Orleans, LA 70112, USA.
| | - Abir A Rahman
- Department of Neurosurgery, Clinical Neuroscience Research Center, Tulane University School of Medicine, New Orleans, LA 70112, USA.
| | - Emmanuel Pinteaux
- Faculty of Biology, Medicine and Health, A.V. Hill Building, University of Manchester, Oxford Road, Manchester, M13 9PT, United Kingdom.
| | - Gregory Bix
- Department of Neurosurgery, Clinical Neuroscience Research Center, Tulane University School of Medicine, New Orleans, LA 70112, USA; Faculty of Biology, Medicine and Health, A.V. Hill Building, University of Manchester, Oxford Road, Manchester, M13 9PT, United Kingdom; Tulane Brain Institute, Tulane University, New Orleans, LA 70118, USA.
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25
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Gautam J, Xu L, Nirwane A, Nguyen B, Yao Y. Loss of mural cell-derived laminin aggravates hemorrhagic brain injury. J Neuroinflammation 2020; 17:103. [PMID: 32252790 PMCID: PMC7133020 DOI: 10.1186/s12974-020-01788-3] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2020] [Accepted: 03/25/2020] [Indexed: 02/05/2023] Open
Abstract
BACKGROUND Mural cells synthesize and deposit laminin to the basement membrane. To investigate the function of mural cell-derived laminin, we generated a mutant mouse line lacking mural cell-derived laminin (termed PKO). In a previous study, we showed that the PKO mice were grossly normal under homeostatic condition, but developed blood-brain barrier (BBB) breakdown with advanced age (> 8 months), suggesting that these mutants are intrinsically weak. Based on these findings, we hypothesized that PKO mice have exacerbated injuries in pathological conditions. METHODS Using collagenase-induced intracerebral hemorrhage (ICH) as an injury model, we examined various stroke outcomes, including hematoma volume, neurological function, neuronal death, BBB integrity, paracellular/transcellular transport, inflammatory cell infiltration, and brain water content, in PKO mice and their wildtype littermates at young age (6-8 weeks). In addition, transmission electron microscopy (TEM) analysis and an in vitro ICH model were used to investigate the underlying molecular mechanisms. RESULTS Compared to age-matched wildtype littermates, PKO mice display aggravated stroke outcomes, including larger hematoma size, worse neurological function, increased neuronal cell death, enhanced BBB permeability, increased transcytosis, and elevated inflammatory cell infiltration. These mutants also exhibit high baseline brain water content independent of aquaporin-4 (AQP4). In addition, mural cell-derived laminin significantly reduced caveolin-1 without affecting tight junction proteins in the in vitro ICH model. CONCLUSIONS These results suggest that mural cell-derived laminin attenuates BBB damage in ICH via decreasing caveolin-1 and thus transcytosis, regulates brain water homeostasis, and plays a beneficial role in ICH.
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Affiliation(s)
- Jyoti Gautam
- Department of Pharmaceutical and Biomedical Sciences, University of Georgia, 240 W Green Street, Athens, GA, 30602, USA
| | - Lingling Xu
- Department of Pharmaceutical and Biomedical Sciences, University of Georgia, 240 W Green Street, Athens, GA, 30602, USA
| | - Abhijit Nirwane
- Department of Pharmaceutical and Biomedical Sciences, University of Georgia, 240 W Green Street, Athens, GA, 30602, USA
| | - Benjamin Nguyen
- Department of Pharmaceutical and Biomedical Sciences, University of Georgia, 240 W Green Street, Athens, GA, 30602, USA
| | - Yao Yao
- Department of Pharmaceutical and Biomedical Sciences, University of Georgia, 240 W Green Street, Athens, GA, 30602, USA.
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26
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Affiliation(s)
- Minkyung Kang
- From the Department of Pharmaceutical and Biomedical Sciences, University of Georgia, Athens, GA
| | - Yao Yao
- From the Department of Pharmaceutical and Biomedical Sciences, University of Georgia, Athens, GA
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27
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A critical role for microglia in maintaining vascular integrity in the hypoxic spinal cord. Proc Natl Acad Sci U S A 2019; 116:26029-26037. [PMID: 31772011 DOI: 10.1073/pnas.1912178116] [Citation(s) in RCA: 57] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Hypoxic preconditioning reduces disease severity in a mouse model of multiple sclerosis (MS), in part by enhancing the barrier properties of spinal cord blood vessels. Because other studies have shown that similar levels of hypoxia transiently increase permeability of central nervous system (CNS) blood vessels, the goal of this study was to define the impact of chronic mild hypoxia (CMH, 8% O2) on the integrity of spinal cord blood vessels and the responses of neighboring glial cells. Using extravascular fibrinogen as a marker of vascular disruption, we found that CMH triggered transient vascular leak in spinal cord blood vessels, particularly in white matter, which was associated with clustering and activation of Mac-1-positive microglia around disrupted vessels. Microglial depletion with the colony stimulating factor-1 receptor (CSF-1R) inhibitor PLX5622, while having no effect under normoxic conditions, profoundly increased vascular leak in both white and gray matter during CMH, and this was associated with disruption of astrocyte-vascular coupling and enhanced loss of tight junction proteins. Microglial repair of leaky blood vessels was blocked by a peptide that inhibits the interaction between fibrinogen and its Mac-1 integrin receptor. These findings highlight an important role for microglia in maintaining vascular integrity in the hypoxic spinal cord and suggest that a fibrinogen-Mac-1 interaction underpins this response. As relative hypoxia is experienced in many situations including high altitude, lung disease, obstructive sleep apnea, and age-related CNS ischemia/hypoxia, our findings have important implications regarding the critical role of microglia in maintaining vascular integrity in the CNS.
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28
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Abstract
The endothelium physically separates blood from surrounding tissue and yet allows for the regulated passage of nutrients, waste, and leukocytes into and out of the circulation. Trans-endothelium flux occurs across endothelial cells (transcellular) and between endothelial cells (paracellular). Paracellular endothelial barrier function depends on the regulation of cell-cell junctions. Interestingly, a functional relationship between cell-cell junctions and cell-matrix adhesions has long been appreciated but the molecular mechanisms underpinning this relationship are not fully understood. Here we review the evidence that supports the notion that cell-matrix interactions contribute to the regulation of cell-cell junctions, focusing primarily on the important adherens junction protein VE-cadherin. In particular, we will discuss recent insights gained into how integrin signaling impacts VE-cadherin stability in adherens junctions and endothelial barrier function.
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Affiliation(s)
- Fadi E Pulous
- Department of Pediatrics, Aflac Cancer and Blood Disorders Center (FEP, BGP) and Cancer Biology Graduate Program (FEP), Emory University School of Medicine, Atlanta, GA, USA
| | - Brian G Petrich
- Department of Pediatrics, Aflac Cancer and Blood Disorders Center (FEP, BGP) and Cancer Biology Graduate Program (FEP), Emory University School of Medicine, Atlanta, GA, USA
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29
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Costea L, Mészáros Á, Bauer H, Bauer HC, Traweger A, Wilhelm I, Farkas AE, Krizbai IA. The Blood-Brain Barrier and Its Intercellular Junctions in Age-Related Brain Disorders. Int J Mol Sci 2019; 20:ijms20215472. [PMID: 31684130 PMCID: PMC6862160 DOI: 10.3390/ijms20215472] [Citation(s) in RCA: 57] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2019] [Revised: 10/30/2019] [Accepted: 11/01/2019] [Indexed: 12/14/2022] Open
Abstract
With age, our cognitive skills and abilities decline. Maybe starting as an annoyance, this decline can become a major impediment to normal daily life. Recent research shows that the neurodegenerative disorders responsible for age associated cognitive dysfunction are mechanistically linked to the state of the microvasculature in the brain. When the microvasculature does not function properly, ischemia, hypoxia, oxidative stress and related pathologic processes ensue, further damaging vascular and neural function. One of the most important and specialized functions of the brain microvasculature is the blood-brain barrier (BBB), which controls the movement of molecules between blood circulation and the brain parenchyma. In this review, we are focusing on tight junctions (TJs), the multiprotein complexes that play an important role in establishing and maintaining barrier function. After a short introduction of the cell types that modulate barrier function via intercellular communication, we examine how age, age related pathologies and the aging of the immune system affects TJs. Then, we review how the TJs are affected in age associated neurodegenerative disorders: Alzheimer's disease and Parkinson's disease. Lastly, we summarize the TJ aspects of Huntington's disease and schizophrenia. Barrier dysfunction appears to be a common denominator in neurological disorders, warranting detailed research into the molecular mechanisms behind it. Learning the commonalities and differences in the pathomechanism of the BBB injury in different neurological disorders will predictably lead to development of new therapeutics that improve our life as we age.
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Affiliation(s)
- Laura Costea
- Institute of Life Sciences, Vasile Goldiş Western University of Arad, 310414 Arad, Romania.
| | - Ádám Mészáros
- Institute of Biophysics, Biological Research Centre, 6726 Szeged, Hungary.
- Doctoral School of Biology, University of Szeged, 6726 Szeged, Hungary.
| | - Hannelore Bauer
- Department of Biological Sciences, University of Salzburg, 5020 Salzburg, Austria.
| | - Hans-Christian Bauer
- Institute of Tendon and Bone Regeneration, Paracelsus Medical University-Spinal Cord Injury and Tissue Regeneration Center Salzburg, 5020 Salzburg, Austria.
| | - Andreas Traweger
- Institute of Tendon and Bone Regeneration, Paracelsus Medical University-Spinal Cord Injury and Tissue Regeneration Center Salzburg, 5020 Salzburg, Austria.
| | - Imola Wilhelm
- Institute of Life Sciences, Vasile Goldiş Western University of Arad, 310414 Arad, Romania.
- Institute of Biophysics, Biological Research Centre, 6726 Szeged, Hungary.
| | - Attila E Farkas
- Institute of Biophysics, Biological Research Centre, 6726 Szeged, Hungary.
- Department of Physiology, Anatomy and Neuroscience, University of Szeged, 6726 Szeged, Hungary.
| | - István A Krizbai
- Institute of Life Sciences, Vasile Goldiş Western University of Arad, 310414 Arad, Romania.
- Institute of Biophysics, Biological Research Centre, 6726 Szeged, Hungary.
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30
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Overexpression of α5β1 integrin and angiopoietin-1 co-operatively promote blood-brain barrier integrity and angiogenesis following ischemic stroke. Exp Neurol 2019; 321:113042. [DOI: 10.1016/j.expneurol.2019.113042] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2019] [Revised: 08/18/2019] [Accepted: 08/20/2019] [Indexed: 12/24/2022]
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31
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Nakamura K, Ikeuchi T, Nara K, Rhodes CS, Zhang P, Chiba Y, Kazuno S, Miura Y, Ago T, Arikawa-Hirasawa E, Mukouyama YS, Yamada Y. Perlecan regulates pericyte dynamics in the maintenance and repair of the blood-brain barrier. J Cell Biol 2019; 218:3506-3525. [PMID: 31541017 PMCID: PMC6781430 DOI: 10.1083/jcb.201807178] [Citation(s) in RCA: 50] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2018] [Revised: 02/10/2019] [Accepted: 07/31/2019] [Indexed: 01/24/2023] Open
Abstract
Ischemic stroke causes blood-brain barrier (BBB) breakdown due to significant damage to the integrity of BBB components. Recent studies have highlighted the importance of pericytes in the repair process of BBB functions triggered by PDGFRβ up-regulation. Here, we show that perlecan, a major heparan sulfate proteoglycan of basement membranes, aids in BBB maintenance and repair through pericyte interactions. Using a transient middle cerebral artery occlusion model, we found larger infarct volumes and more BBB leakage in conditional perlecan (Hspg2)-deficient (Hspg2 - / - -TG) mice than in control mice. Control mice showed increased numbers of pericytes in the ischemic lesion, whereas Hspg2 - / - -TG mice did not. At the mechanistic level, pericytes attached to recombinant perlecan C-terminal domain V (perlecan DV, endorepellin). Perlecan DV enhanced the PDGF-BB-induced phosphorylation of PDGFRβ, SHP-2, and FAK partially through integrin α5β1 and promoted pericyte migration. Perlecan therefore appears to regulate pericyte recruitment through the cooperative functioning of PDGFRβ and integrin α5β1 to support BBB maintenance and repair following ischemic stroke.
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Affiliation(s)
- Kuniyuki Nakamura
- Molecular Biology Section, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD .,Department of Medicine and Clinical Science, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Tomoko Ikeuchi
- Molecular Biology Section, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD
| | - Kazuki Nara
- Molecular Biology Section, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD.,Tohoku University School of Medicine, Sendai, Japan
| | - Craig S Rhodes
- Molecular Biology Section, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD
| | - Peipei Zhang
- Molecular Biology Section, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD
| | - Yuta Chiba
- Molecular Biology Section, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD
| | - Saiko Kazuno
- Laboratory of Proteomics and Biomolecular Science, Research Support Center, Juntendo University Graduate School of Medicine, Tokyo, Japan
| | - Yoshiki Miura
- Laboratory of Proteomics and Biomolecular Science, Research Support Center, Juntendo University Graduate School of Medicine, Tokyo, Japan
| | - Tetsuro Ago
- Department of Medicine and Clinical Science, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Eri Arikawa-Hirasawa
- Research Institute for Diseases of Old Age, Juntendo University Graduate School of Medicine, Tokyo, Japan
| | - Yoh-Suke Mukouyama
- Laboratory of Stem Cell and Neuro-Vascular Biology, Cell and Developmental Biology Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD
| | - Yoshihiko Yamada
- Molecular Biology Section, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD
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32
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Edwards DN, Bix GJ. The Inflammatory Response After Ischemic Stroke: Targeting β 2 and β 1 Integrins. Front Neurosci 2019; 13:540. [PMID: 31191232 PMCID: PMC6546847 DOI: 10.3389/fnins.2019.00540] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Accepted: 05/09/2019] [Indexed: 12/20/2022] Open
Abstract
Ischemic stroke is a leading cause of death and disability with limited therapeutic options. Resulting inflammatory mechanisms after reperfusion (removal of the thrombus) result in cytokine activation, calcium influx, and leukocytic infiltration to the area of ischemia. In particular, leukocytes migrate toward areas of inflammation by use of integrins, particularly integrins β1 and β2. Integrins have been shown to be necessary for leukocyte adhesion and migration, and thus are of immediate interest in many inflammatory diseases, including ischemic stroke. In this review, we identify the main integrins involved in leukocytic migration following stroke (α L β2, αDβ2, α4β1, and α5β1) and targeted clinical therapeutic interventions.
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Affiliation(s)
- Danielle N. Edwards
- Sanders–Brown Center on Aging, University of Kentucky, Lexington, KY, United States
- Department of Neuroscience, University of Kentucky, Lexington, KY, United States
| | - Gregory J. Bix
- Department of Neurology, University of Kentucky, Lexington, KY, United States
- Department of Neurosurgery, University of Kentucky, Lexington, KY, United States
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33
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Nirwane A, Johnson J, Nguyen B, Miner JH, Yao Y. Mural cell-derived laminin-α5 plays a detrimental role in ischemic stroke. Acta Neuropathol Commun 2019; 7:23. [PMID: 30777135 PMCID: PMC6378751 DOI: 10.1186/s40478-019-0676-8] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2018] [Accepted: 02/10/2019] [Indexed: 12/12/2022] Open
Abstract
At the blood-brain barrier (BBB), laminin-α5 is predominantly synthesized by endothelial cells and mural cells. Endothelial laminin-α5 is dispensable for BBB maintenance under homeostatic conditions but inhibits inflammatory cell extravasation in pathological conditions. Whether mural cell-derived laminin-α5 is involved in vascular integrity regulation, however, remains unknown. To answer this question, we generated transgenic mice with laminin-α5 deficiency in mural cells (α5-PKO). Under homeostatic conditions, no defects in BBB integrity and cerebral blood flow (CBF) were observed in α5-PKO mice, suggesting that mural cell-derived laminin-α5 is dispensable for BBB maintenance and CBF regulation under homeostatic conditions. After ischemia-reperfusion (MCAO) injury, however, α5-PKO mice displayed less severe neuronal injury, including reduced infarct volume, decreased neuronal death, and improved neurological function. In addition, α5-PKO mice also showed attenuated vascular damage (milder BBB disruption, reduced inflammatory cell infiltration, decreased brain edema, and diminished hemorrhagic transformation). Mechanistic studies revealed less severe tight junction protein (TJP) loss and pericyte coverage reduction in α5-PKO mice after ischemia-reperfusion injury, indicating that the attenuated ischemic injury in α5-PKO mice is possibly due to less severe vascular damage. These findings suggest that mural cell-derived laminin-α5 plays a detrimental role in ischemic stroke and that inhibiting its signaling may have a neuroprotective effect.
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34
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Kant R, Halder SK, Bix GJ, Milner R. Absence of endothelial α5β1 integrin triggers early onset of experimental autoimmune encephalomyelitis due to reduced vascular remodeling and compromised vascular integrity. Acta Neuropathol Commun 2019; 7:11. [PMID: 30678721 PMCID: PMC6346510 DOI: 10.1186/s40478-019-0659-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2018] [Accepted: 01/08/2019] [Indexed: 01/21/2023] Open
Abstract
Early in the development of multiple sclerosis (MS) and its mouse model experimental autoimmune encephalomyelitis (EAE), vascular integrity is compromised. This is accompanied by a marked vascular remodeling response, though it is currently unclear whether this is an adaptive vascular repair mechanism or is part of the pathogenic process. In light of the well-described angiogenic role for the α5β1 integrin, the goal of this study was to evaluate how genetic deletion of endothelial α5 integrin (α5-EC-KO mice) impacts vascular remodeling and repair following vascular disruption during EAE pathogenesis, and how this subsequently influences clinical progression and inflammatory demyelination. Immunofluorescence staining revealed that fibronectin and α5 integrin expression were strongly upregulated on spinal cord blood vessels during the pre-symptomatic phase of EAE. Interestingly, α5-EC-KO mice showed much earlier onset and faster progression of EAE, though peak disease severity and chronic disease activity were no different from wild-type mice. At the histological level, earlier disease onset in α5-EC-KO mice correlated with accelerated vascular disruption and increased leukocyte infiltration into the spinal cord. Significantly, spinal cord blood vessels in α5-EC-KO mice showed attenuated endothelial proliferation during the pre-symptomatic phase of EAE which resulted in reduced vascular density at later time-points. Under pro-inflammatory conditions, primary cultures of α5KO brain endothelial cells showed reduced proliferation potential. These findings suggest that α5β1 integrin-mediated angiogenic remodeling represents an important repair mechanism that counteracts vascular disruption during the early stages of EAE development.
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35
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Wang HJ, Wei JY, Liu DX, Zhuang SF, Li Y, Liu H, Ban M, Fang WG, Cao L, Zhao WD, Chen YH. Endothelial Atg7 Deficiency Ameliorates Acute Cerebral Injury Induced by Ischemia/Reperfusion. Front Neurol 2018; 9:998. [PMID: 30555402 PMCID: PMC6280951 DOI: 10.3389/fneur.2018.00998] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2018] [Accepted: 11/05/2018] [Indexed: 12/24/2022] Open
Abstract
Ischemic strokes often result in cerebral injury due to ischemia/reperfusion (I/R). Although the local inflammatory responses are known to play a primary role in the brain I/R injury, the underlying mechanism remains unclear. In the current study, we investigated the effect of brain endothelial Atg7 (autophagy related 7) depletion in the acute brain injury induced by ischemia and reperfusion. Endothelial knockout of Atg7 in mice (Atg7 eKO) was found to significantly attenuate both the infarct volume and the neurological defects induced by I/R when compared to the controls. In fact, brain inflammatory responses induced by I/R were alleviated by the Atg7 eKO. Furthermore, an increased expression of pro-inflammatory cytokines, including IL-1β, IL-6, IL-8, and TNF-α, was observed in brain endothelial cells in response to oxygen/glucose depletion/reoxygenation, which was decreased by the shRNA-mediated Atg7 knockdown. Interestingly, Atg7 knockdown reduced IKKβ phosphorylation, leading to NF-κB deactivation and downregulation of the pro-inflammatory cytokines mRNA levels. Further, Atg7 transcriptional regulation function is independent of its role in autophagy. Taken together, our results demonstrated that brain endothelial Atg7 contributes to brain damage during I/R by modulating the expression of pro-inflammatory cytokines. Depletion of Atg7 in brain endothelium has a neuroprotective effect against the ischemia/reperfusion-induced acute cerebral injury during stroke.
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Affiliation(s)
- Hui-Jie Wang
- Key Laboratory of Cell Biology, Ministry of Public Health, and Key Laboratory of Medical Cell Biology, Ministry of Education, Department of Developmental Cell Biology, China Medical University, Shenyang, China
| | - Jia-Yi Wei
- Key Laboratory of Cell Biology, Ministry of Public Health, and Key Laboratory of Medical Cell Biology, Ministry of Education, Department of Developmental Cell Biology, China Medical University, Shenyang, China
| | - Dong-Xin Liu
- Key Laboratory of Cell Biology, Ministry of Public Health, and Key Laboratory of Medical Cell Biology, Ministry of Education, Department of Developmental Cell Biology, China Medical University, Shenyang, China
| | - Shi-Fang Zhuang
- Key Laboratory of Cell Biology, Ministry of Public Health, and Key Laboratory of Medical Cell Biology, Ministry of Education, Department of Developmental Cell Biology, China Medical University, Shenyang, China
| | - Yuan Li
- Key Laboratory of Cell Biology, Ministry of Public Health, and Key Laboratory of Medical Cell Biology, Ministry of Education, Department of Developmental Cell Biology, China Medical University, Shenyang, China
| | - Hui Liu
- Key Laboratory of Cell Biology, Ministry of Public Health, and Key Laboratory of Medical Cell Biology, Ministry of Education, Department of Developmental Cell Biology, China Medical University, Shenyang, China
| | - Meng Ban
- Key Laboratory of Cell Biology, Ministry of Public Health, and Key Laboratory of Medical Cell Biology, Ministry of Education, Department of Developmental Cell Biology, China Medical University, Shenyang, China
| | - Wen-Gang Fang
- Key Laboratory of Cell Biology, Ministry of Public Health, and Key Laboratory of Medical Cell Biology, Ministry of Education, Department of Developmental Cell Biology, China Medical University, Shenyang, China
| | - Liu Cao
- Key Laboratory of Cell Biology, Ministry of Public Health, and Key Laboratory of Medical Cell Biology, Ministry of Education, Department of Developmental Cell Biology, China Medical University, Shenyang, China
| | - Wei-Dong Zhao
- Key Laboratory of Cell Biology, Ministry of Public Health, and Key Laboratory of Medical Cell Biology, Ministry of Education, Department of Developmental Cell Biology, China Medical University, Shenyang, China
| | - Yu-Hua Chen
- Key Laboratory of Cell Biology, Ministry of Public Health, and Key Laboratory of Medical Cell Biology, Ministry of Education, Department of Developmental Cell Biology, China Medical University, Shenyang, China
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36
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Edwards DN, Bix GJ. Roles of blood-brain barrier integrins and extracellular matrix in stroke. Am J Physiol Cell Physiol 2018; 316:C252-C263. [PMID: 30462535 DOI: 10.1152/ajpcell.00151.2018] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Ischemicstroke is a leading cause of death and disability in the United States, but recent advances in treatments [i.e., endovascular thrombectomy and tissue plasminogen activator (t-PA)] that target the stroke-causing blood clot, while improving overall stroke mortality rates, have had much less of an impact on overall stroke morbidity. This may in part be attributed to the lack of therapeutics targeting reperfusion-induced injury after the blood clot has been removed, which, if left unchecked, can expand injury from its core into the surrounding at risk tissue (penumbra). This occurs in two phases of increased permeability of the blood-brain barrier, a physical barrier that under physiologic conditions regulates brain influx and efflux of substances and consists of tight junction forming endothelial cells (and transporter proteins), astrocytes, pericytes, extracellular matrix, and their integrin cellular receptors. During, embryonic development, maturity, and following stroke reperfusion, cerebral vasculature undergoes significant changes including changes in expression of integrins and degradation of surrounding extracellular matrix. Integrins, heterodimers with α and β subunits, and their extracellular matrix ligands, a collection of proteoglycans, glycoproteins, and collagens, have been modestly studied in the context of stroke compared with other diseases (e.g., cancer). In this review, we describe the effect that various integrins and extracellular matrix components have in embryonic brain development, and how this changes in both maturity and in the poststroke environment. Particular focus will be on how these changes in integrins and the extracellular matrix affect blood-brain barrier components and their potential as diagnostic and therapeutic targets for ischemic stroke.
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Affiliation(s)
- Danielle N Edwards
- Sanders-Brown Center on Aging, University of Kentucky , Lexington, Kentucky.,Department of Neuroscience, University of Kentucky , Lexington, Kentucky
| | - Gregory J Bix
- Sanders-Brown Center on Aging, University of Kentucky , Lexington, Kentucky.,Department of Neuroscience, University of Kentucky , Lexington, Kentucky.,Department of Neurology, University of Kentucky , Lexington, Kentucky.,Department of Neurosurgery, University of Kentucky , Lexington, Kentucky
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37
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Li Y, Zhu ZY, Huang TT, Zhou YX, Wang X, Yang LQ, Chen ZA, Yu WF, Li PY. The peripheral immune response after stroke-A double edge sword for blood-brain barrier integrity. CNS Neurosci Ther 2018; 24:1115-1128. [PMID: 30387323 PMCID: PMC6490160 DOI: 10.1111/cns.13081] [Citation(s) in RCA: 57] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2018] [Revised: 10/09/2018] [Accepted: 10/09/2018] [Indexed: 02/07/2023] Open
Abstract
The blood‐brain barrier (BBB) is a highly regulated interface that separates the peripheral circulation and the brain. It plays a vital role in regulating the trafficking of solutes, fluid, and cells at the blood‐brain interface and maintaining the homeostasis of brain microenvironment for normal neuronal activity. Growing evidence has led to the realization that ischemic stroke elicits profound immune responses in the circulation and the activation of multiple subsets of immune cells, which in turn affect both the early disruption and the later repair of the BBB after stroke. Distinct phenotypes or subsets of peripheral immune cells along with diverse intracellular mechanisms contribute to the dynamic changes of BBB integrity after stroke. This review focuses on the interaction between the peripheral immune cells and the BBB after ischemic stroke. Understanding their reciprocal interaction may generate new directions for stroke research and may also drive the innovation of easy accessible immune modulatory treatment strategies targeting BBB in the pursuit of better stroke recovery.
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Affiliation(s)
- Yan Li
- Department of Anesthesiology, Renji Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai, China
| | - Zi-Yu Zhu
- Department of Anesthesiology, Renji Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai, China
| | - Ting-Ting Huang
- Department of Anesthesiology, Renji Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai, China
| | - Yu-Xi Zhou
- Department of Anesthesiology, Renji Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai, China
| | - Xin Wang
- Department of Anesthesiology, Renji Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai, China
| | - Li-Qun Yang
- Department of Anesthesiology, Renji Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai, China
| | - Zeng-Ai Chen
- Department of Radiology, Renji Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai, China
| | - Wei-Feng Yu
- Department of Anesthesiology, Renji Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai, China
| | - Pei-Ying Li
- Department of Anesthesiology, Renji Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai, China
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38
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Abdullahi W, Tripathi D, Ronaldson PT. Blood-brain barrier dysfunction in ischemic stroke: targeting tight junctions and transporters for vascular protection. Am J Physiol Cell Physiol 2018; 315:C343-C356. [PMID: 29949404 DOI: 10.1152/ajpcell.00095.2018] [Citation(s) in RCA: 335] [Impact Index Per Article: 55.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The blood-brain barrier (BBB) is a physical and biochemical barrier that precisely controls cerebral homeostasis. It also plays a central role in the regulation of blood-to-brain flux of endogenous and exogenous xenobiotics and associated metabolites. This is accomplished by molecular characteristics of brain microvessel endothelial cells such as tight junction protein complexes and functional expression of influx and efflux transporters. One of the pathophysiological features of ischemic stroke is disruption of the BBB, which significantly contributes to development of brain injury and subsequent neurological impairment. Biochemical characteristics of BBB damage include decreased expression and altered organization of tight junction constituent proteins as well as modulation of functional expression of endogenous BBB transporters. Therefore, there is a critical need for development of novel therapeutic strategies that can protect against BBB dysfunction (i.e., vascular protection) in the setting of ischemic stroke. Such strategies include targeting tight junctions to ensure that they maintain their correct structure or targeting transporters to control flux of physiological substrates for protection of endothelial homeostasis. In this review, we will describe the pathophysiological mechanisms in cerebral microvascular endothelial cells that lead to BBB dysfunction following onset of stroke. Additionally, we will utilize this state-of-the-art knowledge to provide insights on novel pharmacological strategies that can be developed to confer BBB protection in the setting of ischemic stroke.
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Affiliation(s)
- Wazir Abdullahi
- Department of Pharmacology, College of Medicine, University of Arizona , Tucson, Arizona
| | - Dinesh Tripathi
- Department of Pharmacology, College of Medicine, University of Arizona , Tucson, Arizona
| | - Patrick T Ronaldson
- Department of Pharmacology, College of Medicine, University of Arizona , Tucson, Arizona
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Piro JR, Suidan GL, Quan J, Pi Y, O'Neill SM, Ilardi M, Pozdnyakov N, Lanz TA, Xi H, Bell RD, Samad TA. Inhibition of 2-AG hydrolysis differentially regulates blood brain barrier permeability after injury. J Neuroinflammation 2018; 15:142. [PMID: 29759062 PMCID: PMC5952841 DOI: 10.1186/s12974-018-1166-9] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2018] [Accepted: 04/18/2018] [Indexed: 12/16/2022] Open
Abstract
Background Acute neurological insults caused by infection, systemic inflammation, ischemia, or traumatic injury are often associated with breakdown of the blood-brain barrier (BBB) followed by infiltration of peripheral immune cells, cytotoxic proteins, and water. BBB breakdown and extravasation of these peripheral components into the brain parenchyma result in inflammation, oxidative stress, edema, excitotoxicity, and neurodegeneration. These downstream consequences of BBB dysfunction can drive pathophysiological processes and play a substantial role in the morbidity and mortality of acute and chronic neurological insults, and contribute to long-term sequelae. Preserving or rescuing BBB integrity and homeostasis therefore represents a translational research area of high therapeutic potential. Methods Induction of general and localized BBB disruption in mice was carried out using systemic administration of LPS and focal photothrombotic ischemic insult, respectively, in the presence and absence of the monoacylglycerol lipase (MAGL) inhibitor, CPD-4645. The effects of CPD-4645 treatment were assessed by gene expression analysis performed on neurovascular-enriched brain fractions, cytokine and inflammatory mediator measurement, and functional assessment of BBB permeability. The mechanism of action of CPD-4645 was studied pharmacologically using inverse agonists/antagonists of the cannabinoid receptors CB1 and CB2. Results Here, we demonstrate that the neurovasculature exhibits a unique transcriptional signature following inflammatory insults, and pharmacological inhibition of MAGL using a newly characterized inhibitor rescues the transcriptional profile of brain vasculature and restores its functional homeostasis. This pronounced effect of MAGL inhibition on blood-brain barrier permeability is evident following both systemic inflammatory and localized ischemic insults. Mechanistically, the protective effects of the MAGL inhibitor are partially mediated by cannabinoid receptor signaling in the ischemic brain insult. Conclusions Our results support considering MAGL inhibitors as potential therapeutics for BBB dysfunction and cerebral edema associated with inflammatory brain insults. Electronic supplementary material The online version of this article (10.1186/s12974-018-1166-9) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Justin R Piro
- Pfizer Worldwide Research & Development, Cambridge, MA, 02139, USA. .,Present Address: Abbvie Inc., 200 Sidney St., Cambridge, MA, 02139, USA.
| | - Georgette L Suidan
- Pfizer Worldwide Research & Development, Cambridge, MA, 02139, USA.,Present Address: Biogen, 225 Binney St., Cambridge, MA, 02142, USA
| | - Jie Quan
- Pfizer Worldwide Research & Development, Cambridge, MA, 02139, USA
| | - YeQing Pi
- Pfizer Worldwide Research & Development, Cambridge, MA, 02139, USA.,Present Address: Biogen, 225 Binney St., Cambridge, MA, 02142, USA
| | - Sharon M O'Neill
- Pfizer Worldwide Research & Development, Cambridge, MA, 02139, USA.,Present Address: Biogen, 225 Binney St., Cambridge, MA, 02142, USA
| | - Marissa Ilardi
- Pfizer Worldwide Research & Development, Cambridge, MA, 02139, USA.,Present Address: NYU School of Medicine, 550 1st Ave., New York, NY, 10016, USA
| | | | - Thomas A Lanz
- Pfizer Worldwide Research & Development, Cambridge, MA, 02139, USA.,Present Address: Biogen, 225 Binney St., Cambridge, MA, 02142, USA
| | - Hualin Xi
- Pfizer Worldwide Research & Development, Cambridge, MA, 02139, USA.,Present Address: Abbvie Inc., 200 Sidney St., Cambridge, MA, 02139, USA
| | - Robert D Bell
- Pfizer Worldwide Research & Development, Cambridge, MA, 02139, USA
| | - Tarek A Samad
- Pfizer Worldwide Research & Development, Cambridge, MA, 02139, USA. .,Present Address: Sanofi R&D, 49 New York Ave., Framingham, MA, 01701, USA.
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Bilateral carotid artery stenosis causes unexpected early changes in brain extracellular matrix and blood-brain barrier integrity in mice. PLoS One 2018; 13:e0195765. [PMID: 29649307 PMCID: PMC5897017 DOI: 10.1371/journal.pone.0195765] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2017] [Accepted: 03/28/2018] [Indexed: 12/21/2022] Open
Abstract
Bilateral carotid artery stenosis (BCAS) is one experimental model of vascular dementia thought to preferentially impact brain white matter. Indeed, few studies report hippocampal and cortical pathology prior to 30 days post-stenosis; though it is unclear whether those studies examined regions outside the white matter. Since changes in the blood-brain barrier (BBB) permeability precede more overt brain pathology in various diseases, we hypothesized that changes within the BBB and/or BBB-associated extracellular matrix (ECM) could occur earlier after BCAS in the hippocampus, cortex and striatum and be a precursor of longer term pathology. Here, C57Bl/6 mice underwent BCAS or sham surgeries and changes in the BBB and ECM were analyzed by collagen IV (vascular basement membrane component), α5 integrin (marker of endothelial activation), claudin-5 and occludin (tight junction proteins), Evans blue (permeability marker), Ki-67 (cell proliferation marker), and GFAP and CD11b (glial cell markers) immunohistochemistry after 14 days. Significant changes in markers of cerebrovascular integrity and glial activation were detected, not only in the striatum, but also in the hippocampus and cortex. In conclusion, this study demonstrates for the first time that changes in the BBB/ECM occur shortly after BCAS and within multiple brain regions and suggests such changes might underlie the gradual development of BCAS non-white matter pathology.
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Izawa Y, Gu YH, Osada T, Kanazawa M, Hawkins BT, Koziol JA, Papayannopoulou T, Spatz M, Del Zoppo GJ. β1-integrin-matrix interactions modulate cerebral microvessel endothelial cell tight junction expression and permeability. J Cereb Blood Flow Metab 2018; 38:641-658. [PMID: 28787238 PMCID: PMC5888854 DOI: 10.1177/0271678x17722108] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Acutely following focal cerebral ischemia disruption of the microvessel blood-brain barrier allows transit of plasma proteins into the neuropil as edema formation that coincides with loss of microvessel endothelial β1-integrins. We extend previous findings to show that interference with endothelial β1-integrin-matrix adhesion by the monoclonal IgM Ha2/5 increases the permeability of primary cerebral microvascular endothelial cell monolayers through reorganization of claudin-5, occludin, and zonula occludens-1 (ZO-1) from inter-endothelial borders. Interference with β1-integrin-matrix adhesion initiates F-actin conformational changes that coincide with claudin-5 redistribution. β1-integrin-matrix interference simultaneously increases phosphorylation of myosin light chain (MLC), while inhibition of MLC kinase (MLCK) and Rho kinase (ROCK) abolishes the Ha2/5-dependent increased endothelial permeability by 6 h after β1-integrin-matrix interference. These observations are supported by concordant observations in the cortex of a high-quality murine conditional β1-integrin deletion construct. Together they support the hypothesis that detachment of β1-integrins from abluminal matrix ligands increases vascular endothelial permeability through reorganization of tight junction (TJ) proteins via altered F-actin conformation, and indicate that the β1-integrin-MLC signaling pathway is engaged when β1-integrin detachment occurs. These findings provide a novel approach to the research and treatment of cerebral disorders where the breakdown of the blood-brain barrier accounts for their progression and complication.
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Affiliation(s)
- Yoshikane Izawa
- 1 Division of Hematology, Department of Medicine, University of Washington School of Medicine, Seattle, WA, USA.,2 Department of Neurology, Keio University School of Medicine, Tokyo, Japan
| | - Yu-Huan Gu
- 1 Division of Hematology, Department of Medicine, University of Washington School of Medicine, Seattle, WA, USA
| | - Takashi Osada
- 1 Division of Hematology, Department of Medicine, University of Washington School of Medicine, Seattle, WA, USA.,2 Department of Neurology, Keio University School of Medicine, Tokyo, Japan
| | - Masato Kanazawa
- 1 Division of Hematology, Department of Medicine, University of Washington School of Medicine, Seattle, WA, USA.,3 Department of Neurology, Brain Research Institute, Niigata University, Niigata, Japan
| | - Brian T Hawkins
- 1 Division of Hematology, Department of Medicine, University of Washington School of Medicine, Seattle, WA, USA.,4 Discovery, Science, & Technology, RTI International, Research Triangle Park, NC, USA
| | - James A Koziol
- 5 Department of Molecular and Experimental Medicine, The Scripps Research Institute, La Jolla, CA, USA
| | - Thalia Papayannopoulou
- 1 Division of Hematology, Department of Medicine, University of Washington School of Medicine, Seattle, WA, USA
| | - Maria Spatz
- 6 Stroke Branch, National Institute of Neurological Disorders and Stroke, Bethesda, MD, USA
| | - Gregory J Del Zoppo
- 1 Division of Hematology, Department of Medicine, University of Washington School of Medicine, Seattle, WA, USA.,7 Department of Neurology, University of Washington School of Medicine, Seattle, WA, USA
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Lv J, Hu W, Yang Z, Li T, Jiang S, Ma Z, Chen F, Yang Y. Focusing on claudin-5: A promising candidate in the regulation of BBB to treat ischemic stroke. Prog Neurobiol 2017; 161:79-96. [PMID: 29217457 DOI: 10.1016/j.pneurobio.2017.12.001] [Citation(s) in RCA: 92] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2017] [Revised: 10/20/2017] [Accepted: 12/03/2017] [Indexed: 12/11/2022]
Abstract
Claudin-5 is a tight junction (TJ) protein in the blood-brain barrier (BBB) that has recently attracted increased attention. Numerous studies have demonstrated that claudin-5 regulates the integrity and permeability of the BBB. Increased claudin-5 expression plays a neuroprotective role in neurological diseases, particularly in cerebral ischemic stroke. Moreover, claudin-5 might be a potential marker for early hemorrhagic transformation detection in ischemic stroke. In light of the distinctive effects of claudin-5 on the nervous system, we present the elaborate network of roles that claudin-5 plays in ischemic stroke. In this review, we first introduce basic knowledge regarding the BBB and the claudin family, the characterization and regulation of claudin-5, and association between claudin-5 and other TJ proteins. Subsequently, we describe BBB dysfunction and neuron-specific drivers of pathogenesis of ischemic stroke, including inflammatory disequilibrium and oxidative stress. Furthermore, we summarize promising ischemic stroke treatments that target the BBB via claudin-5, including modified rt-PA therapy, pharmacotherapy, hormone treatment, receptor-targeted therapy, gene therapy, and physical therapy. This review highlights recent advances and provides a comprehensive summary of claudin-5 in the regulation of the BBB and may be helpful for drug design and clinical therapy for treatment of ischemic stroke.
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Affiliation(s)
- Jianjun Lv
- Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education. Faculty of Life Sciences, Northwest University, 229 Taibai North Road, Xi'an 710069, China; Department of Biomedical Engineering, The Fourth Military Medical University, 169 Changle West Road, Xi'an 710032, China
| | - Wei Hu
- Department of Biomedical Engineering, The Fourth Military Medical University, 169 Changle West Road, Xi'an 710032, China; Department of Immunology, The Fourth Military Medical University, 169 Changle West Road, Xi'an 710032, China
| | - Zhi Yang
- Department of Biomedical Engineering, The Fourth Military Medical University, 169 Changle West Road, Xi'an 710032, China
| | - Tian Li
- Department of Biomedical Engineering, The Fourth Military Medical University, 169 Changle West Road, Xi'an 710032, China
| | - Shuai Jiang
- Department of Aerospace Medicine, The Fourth Military Medical University, 169 Changle West Road, Xi'an 710032, China
| | - Zhiqiang Ma
- Department of Thoracic Surgery, Tangdu Hospital, The Fourth Military Medical University, 1 Xinsi Road, Xi'an 710038, China
| | - Fulin Chen
- Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education. Faculty of Life Sciences, Northwest University, 229 Taibai North Road, Xi'an 710069, China
| | - Yang Yang
- Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education. Faculty of Life Sciences, Northwest University, 229 Taibai North Road, Xi'an 710069, China; Department of Biomedical Engineering, The Fourth Military Medical University, 169 Changle West Road, Xi'an 710032, China.
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Lacolley P, Regnault V, Segers P, Laurent S. Vascular Smooth Muscle Cells and Arterial Stiffening: Relevance in Development, Aging, and Disease. Physiol Rev 2017; 97:1555-1617. [DOI: 10.1152/physrev.00003.2017] [Citation(s) in RCA: 332] [Impact Index Per Article: 47.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2017] [Revised: 05/15/2017] [Accepted: 05/26/2017] [Indexed: 12/18/2022] Open
Abstract
The cushioning function of large arteries encompasses distension during systole and recoil during diastole which transforms pulsatile flow into a steady flow in the microcirculation. Arterial stiffness, the inverse of distensibility, has been implicated in various etiologies of chronic common and monogenic cardiovascular diseases and is a major cause of morbidity and mortality globally. The first components that contribute to arterial stiffening are extracellular matrix (ECM) proteins that support the mechanical load, while the second important components are vascular smooth muscle cells (VSMCs), which not only regulate actomyosin interactions for contraction but mediate also mechanotransduction in cell-ECM homeostasis. Eventually, VSMC plasticity and signaling in both conductance and resistance arteries are highly relevant to the physiology of normal and early vascular aging. This review summarizes current concepts of central pressure and tensile pulsatile circumferential stress as key mechanical determinants of arterial wall remodeling, cell-ECM interactions depending mainly on the architecture of cytoskeletal proteins and focal adhesion, the large/small arteries cross-talk that gives rise to target organ damage, and inflammatory pathways leading to calcification or atherosclerosis. We further speculate on the contribution of cellular stiffness along the arterial tree to vascular wall stiffness. In addition, this review provides the latest advances in the identification of gene variants affecting arterial stiffening. Now that important hemodynamic and molecular mechanisms of arterial stiffness have been elucidated, and the complex interplay between ECM, cells, and sensors identified, further research should study their potential to halt or to reverse the development of arterial stiffness.
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Affiliation(s)
- Patrick Lacolley
- INSERM, U1116, Vandœuvre-lès-Nancy, France; Université de Lorraine, Nancy, France; IBiTech-bioMMeda, Department of Electronics and Information Systems, Ghent University, Gent, Belgium; Department of Pharmacology, European Georges Pompidou Hospital, Assistance Publique Hôpitaux de Paris, France; PARCC INSERM, UMR 970, Paris, France; and University Paris Descartes, Paris, France
| | - Véronique Regnault
- INSERM, U1116, Vandœuvre-lès-Nancy, France; Université de Lorraine, Nancy, France; IBiTech-bioMMeda, Department of Electronics and Information Systems, Ghent University, Gent, Belgium; Department of Pharmacology, European Georges Pompidou Hospital, Assistance Publique Hôpitaux de Paris, France; PARCC INSERM, UMR 970, Paris, France; and University Paris Descartes, Paris, France
| | - Patrick Segers
- INSERM, U1116, Vandœuvre-lès-Nancy, France; Université de Lorraine, Nancy, France; IBiTech-bioMMeda, Department of Electronics and Information Systems, Ghent University, Gent, Belgium; Department of Pharmacology, European Georges Pompidou Hospital, Assistance Publique Hôpitaux de Paris, France; PARCC INSERM, UMR 970, Paris, France; and University Paris Descartes, Paris, France
| | - Stéphane Laurent
- INSERM, U1116, Vandœuvre-lès-Nancy, France; Université de Lorraine, Nancy, France; IBiTech-bioMMeda, Department of Electronics and Information Systems, Ghent University, Gent, Belgium; Department of Pharmacology, European Georges Pompidou Hospital, Assistance Publique Hôpitaux de Paris, France; PARCC INSERM, UMR 970, Paris, France; and University Paris Descartes, Paris, France
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Shi J, Chen X, Li H, Wu Y, Wang S, Shi W, Chen J, Ni Y. Neuron-autonomous transcriptome changes upon ischemia/reperfusion injury. Sci Rep 2017; 7:5800. [PMID: 28724924 PMCID: PMC5517505 DOI: 10.1038/s41598-017-05342-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2016] [Accepted: 05/30/2017] [Indexed: 01/22/2023] Open
Abstract
Ischemic stroke and the following reperfusion, an acute therapeutic intervention, can cause irreversible brain damages. However, the underlying pathological mechanisms are still under investigation. To obtain a comprehensive, real-time view of the cell-autonomous mechanisms involved in ischemic stroke and reperfusion, we applied the next-generation sequencing (NGS) technology to characterize the temporal changes in gene expression profiles using primarily cultured hippocampal neurons under an oxygen-glucose deprivation/reperfusion (OGD/R) condition. We first identified the differentially expressed genes (DEGs) between normal cultured neurons, neurons with OGD, and neurons with OGD followed by reperfusion for 6 h, 12 h, and 18 h, respectively. We then performed bioinformatics analyses, including gene ontological (GO) and pathway analysis and co-expression network analysis to screen for novel key pathways and genes involved in the pathology of OGD/R. After we confirmed the changes of selected key genes in hippocampal cultures with OGD/R, we further validated their expression changes in an in vivo ischemic stroke model (MCAO). Finally, we demonstrated that prevention of the up-regulation of a key gene (Itga5) associated with OGD/R promoted hippocampal neuronal survival. Our research thereby provided novel insights into the molecular mechanisms in ischemic stroke pathophysiology and potential targets for therapeutic intervention after ischemic stroke.
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Affiliation(s)
- Jinlong Shi
- Jiangsu Clinical Medicine Center of Tissue Engineering and Nerve Injury Repair and Department of Neurosurgery, Affiliated Hospital of Nantong University, 20 Xisi Road, Nantong, 226001, Jiangsu, China
| | - Xia Chen
- Basic Medical Research Center, Medical School, Nantong University, 19 Qixiu Road, Nantong, 226001, Jiangsu, China.
| | - Haiying Li
- Department of Pediatrics, Affiliated Hospital of Nantong University, 20 Xisi Road, Nantong, 226001, Jiangsu, China
| | - Youjia Wu
- Department of Pediatrics, Affiliated Hospital of Nantong University, 20 Xisi Road, Nantong, 226001, Jiangsu, China
| | - Shouyan Wang
- Basic Medical Research Center, Medical School, Nantong University, 19 Qixiu Road, Nantong, 226001, Jiangsu, China
| | - Wei Shi
- Jiangsu Clinical Medicine Center of Tissue Engineering and Nerve Injury Repair and Department of Neurosurgery, Affiliated Hospital of Nantong University, 20 Xisi Road, Nantong, 226001, Jiangsu, China
| | - Jian Chen
- Jiangsu Clinical Medicine Center of Tissue Engineering and Nerve Injury Repair and Department of Neurosurgery, Affiliated Hospital of Nantong University, 20 Xisi Road, Nantong, 226001, Jiangsu, China
| | - Yaohui Ni
- Jiangsu Clinical Medicine Center of Tissue Engineering and Nerve Injury Repair and Department of Neurology, Affiliated Hospital of Nantong University, 20 Xisi Road, Nantong, 226001, Jiangsu, China.
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McMillin M, DeMorrow S. Effects of bile acids on neurological function and disease. FASEB J 2016; 30:3658-3668. [PMID: 27468758 DOI: 10.1096/fj.201600275r] [Citation(s) in RCA: 113] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2016] [Accepted: 07/18/2016] [Indexed: 12/14/2022]
Abstract
Bile acids are synthesized from cholesterol and are known to be involved with the emulsification and digestion of dietary lipids and fat-soluble vitamins. Outside of this role, bile acids can act as cell signaling effectors through binding and activating receptors on both the cell membrane and nucleus. Numerous reports have investigated these signaling pathways in conditions where the liver is damaged. More recently, effort has been made to investigate the role of bile acids in diseases outside of those associated with liver damage. This review summarizes recent findings on the influences that bile acids can exert in normal neurological function and their contribution to diseases of the nervous system, with the intent of highlighting the role of these metabolites as potential players in neurological disorders.-McMillin, M., DeMorrow, S. Effects of bile acids on neurological function and disease.
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Affiliation(s)
- Matthew McMillin
- Texas A&M University Health Science Center, College of Medicine, Department of Internal Medicine, Temple, Texas, USA; and.,Central Texas Veterans Health Care System, Temple, Texas, USA
| | - Sharon DeMorrow
- Texas A&M University Health Science Center, College of Medicine, Department of Internal Medicine, Temple, Texas, USA; and .,Central Texas Veterans Health Care System, Temple, Texas, USA
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