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Alajangi HK, Kaur M, Sharma A, Rana S, Thakur S, Chatterjee M, Singla N, Jaiswal PK, Singh G, Barnwal RP. Blood-brain barrier: emerging trends on transport models and new-age strategies for therapeutics intervention against neurological disorders. Mol Brain 2022; 15:49. [PMID: 35650613 PMCID: PMC9158215 DOI: 10.1186/s13041-022-00937-4] [Citation(s) in RCA: 29] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Accepted: 05/24/2022] [Indexed: 12/12/2022] Open
Abstract
The integrity of the blood–brain barrier (BBB) is essential for normal central nervous system (CNS) functioning. Considering the significance of BBB in maintaining homeostasis and the neural environment, we aim to provide an overview of significant aspects of BBB. Worldwide, the treatment of neurological diseases caused by BBB disruption has been a major challenge. BBB also restricts entry of neuro-therapeutic drugs and hinders treatment modalities. Hence, currently nanotechnology-based approaches are being explored on large scale as alternatives to conventional methodologies. It is necessary to investigate the in-depth characteristic features of BBB to facilitate the discovery of novel drugs that can successfully cross the barrier and target the disease effectively. It is imperative to discover novel strategies to treat life-threatening CNS diseases in humans. Therefore, insights regarding building blocks of BBB, activation of immune response on breach of this barrier, and various autoimmune neurological disorders caused due to BBB dysfunction are discussed. Further, special emphasis is given on delineating BBB disruption leading to CNS disorders. Moreover, various mechanisms of transport pathways across BBB, several novel strategies, and alternative routes by which drugs can be properly delivered into CNS are also discussed.
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Affiliation(s)
- Hema Kumari Alajangi
- Department of Biophysics, Panjab University, Chandigarh, 160014, India.,University Institute of Pharmaceutical Sciences, Panjab University, Chandigarh, 160014, India
| | - Mandeep Kaur
- Department of Biophysics, Panjab University, Chandigarh, 160014, India
| | - Akanksha Sharma
- Department of Biophysics, Panjab University, Chandigarh, 160014, India.,University Institute of Pharmaceutical Sciences, Panjab University, Chandigarh, 160014, India
| | - Sumedh Rana
- Department of Biophysics, Panjab University, Chandigarh, 160014, India
| | - Shipali Thakur
- Department of Biophysics, Panjab University, Chandigarh, 160014, India
| | - Mary Chatterjee
- Department of Biotechnology, UIET, Panjab University, Chandigarh, 160014, India
| | - Neha Singla
- Department of Biophysics, Panjab University, Chandigarh, 160014, India
| | - Pradeep Kumar Jaiswal
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX, 77843, USA.
| | - Gurpal Singh
- University Institute of Pharmaceutical Sciences, Panjab University, Chandigarh, 160014, India.
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Plasminogen Activators in Neurovascular and Neurodegenerative Disorders. Int J Mol Sci 2021; 22:ijms22094380. [PMID: 33922229 PMCID: PMC8122722 DOI: 10.3390/ijms22094380] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2021] [Revised: 04/14/2021] [Accepted: 04/20/2021] [Indexed: 12/14/2022] Open
Abstract
The neurovascular unit (NVU) is a dynamic structure assembled by endothelial cells surrounded by a basement membrane, pericytes, astrocytes, microglia and neurons. A carefully coordinated interplay between these cellular and non-cellular components is required to maintain normal neuronal function, and in line with these observations, a growing body of evidence has linked NVU dysfunction to neurodegeneration. Plasminogen activators catalyze the conversion of the zymogen plasminogen into the two-chain protease plasmin, which in turn triggers a plethora of physiological events including wound healing, angiogenesis, cell migration and inflammation. The last four decades of research have revealed that the two mammalian plasminogen activators, tissue-type plasminogen activator (tPA) and urokinase-type plasminogen activator (uPA), are pivotal regulators of NVU function during physiological and pathological conditions. Here, we will review the most relevant data on their expression and function in the NVU and their role in neurovascular and neurodegenerative disorders.
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Pétrault M, Casolla B, Ouk T, Cordonnier C, Bérézowski V. Cerebral microbleeds: Beyond the macroscope. Int J Stroke 2019; 14:468-475. [DOI: 10.1177/1747493019830594] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
While being increasingly recognized in clinical routine, brain microbleeds remain a puzzling finding for physicians. These small dot-like lesions are thought to be old perivascular collections of hemosiderin deposits. They can be found in different neurological settings such as cerebrovascular or neurodegenerative diseases. While their microscopic size would suggest considering these lesions as anecdotal, they are now regarded as biomarkers of severity of an underlying cerebrovascular disease. Their natural history and the interactions with surrounding brain cells remain unknown. However, their presence may impact therapeutic decisions. Deciphering the biological mechanisms leading to, or following microbleeds would enable us to address a key question: do microbleeds arise and impact the surrounding parenchyma like a miniature version of intracerebral hemorrhages or do they represent a different kind of injury? We hereby discuss, based on both clinical and experimental literature, the gap between the definition of microbleeds coming from neuroimaging and the pathophysiological hypotheses raised from histopathological and experimental data. Our analysis supports the need for a convergent effort from clinicians and basic scientists to go beyond the current “macro” view and disclose the cellular and molecular insights of these cerebral hemorrhagic microlesions.
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Affiliation(s)
- Maud Pétrault
- Department of Medical Pharmacology, Univ Lille, Inserm U1171-Degenerative and Vascular Cognitive Disorders, CHU Lille, Lille, France
| | - Barbara Casolla
- Department of Neurology, Univ Lille, Inserm U1171-Degenerative and Vascular Cognitive Disorders, CHU Lille, Lille, France
| | - Thavarak Ouk
- Department of Medical Pharmacology, Univ Lille, Inserm U1171-Degenerative and Vascular Cognitive Disorders, CHU Lille, Lille, France
| | - Charlotte Cordonnier
- Department of Neurology, Univ Lille, Inserm U1171-Degenerative and Vascular Cognitive Disorders, CHU Lille, Lille, France
| | - Vincent Bérézowski
- Department of Medical Pharmacology, Univ Lille, Inserm U1171-Degenerative and Vascular Cognitive Disorders, CHU Lille, Lille, France
- Univ Artois, Lens, France
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Gong P, Li M, Zou C, Tian Q, Xu Z. Tissue Plasminogen Activator Causes Brain Microvascular Endothelial Cell Injury After Oxygen Glucose Deprivation by Inhibiting Sonic Hedgehog Signaling. Neurochem Res 2018; 44:441-449. [PMID: 30552546 PMCID: PMC6394519 DOI: 10.1007/s11064-018-2697-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2018] [Revised: 11/22/2018] [Accepted: 12/10/2018] [Indexed: 11/29/2022]
Abstract
The thrombolytic activity of tissue plasminogen activator (tPA) has undisputed benefits. However, the documented neurotoxicity of tPA raises important issues. Currently, common treatments for stroke might not be optimum if exogenous tPA can pass through the blood–brain barrier and enter the brain, thus adding to the deleterious effects of tPA within the cerebral parenchyma. Here, we determined whether tPA could damage brain microvascular endothelial cells (BMECs) during cerebral ischemia. We showed that treatment of BMECs with tPA decreased trans-endothelial electrical resistance and cell proliferation, and blocked the cell cycle at the G0–G1 phase. In addition, the Sonic hedgehog (Shh) signaling pathway was involved in tPA-induced BMECs dysfunction. However, tPA-enhanced oxygen glucose deprivation-induced BMECs dysfunction was eliminated by Shh administration and the effects could be reversed by Shh inhibitors. Taken together, these results demonstrate that tPA administration might result in damage to the endothelial barrier owing to blocked Shh signaling pathway.
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Affiliation(s)
- Pian Gong
- Department of Neurosurgery, Renmin Hospital of Wuhan University, No. 9 Zhangzhidong Road, Wuchang District, Wuhan, 430072, Hubei Province, China
| | - Mingchang Li
- Department of Neurosurgery, Renmin Hospital of Wuhan University, No. 9 Zhangzhidong Road, Wuchang District, Wuhan, 430072, Hubei Province, China.
| | - Changlin Zou
- Department of Neurosurgery, Renmin Hospital of Wuhan University, No. 9 Zhangzhidong Road, Wuchang District, Wuhan, 430072, Hubei Province, China
| | - Qi Tian
- Department of Neurosurgery, Renmin Hospital of Wuhan University, No. 9 Zhangzhidong Road, Wuchang District, Wuhan, 430072, Hubei Province, China
| | - Zhou Xu
- Department of Neurosurgery, Renmin Hospital of Wuhan University, No. 9 Zhangzhidong Road, Wuchang District, Wuhan, 430072, Hubei Province, China
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Ohkura N, Oiwa H, Ohnishi K, Taniguchi M, Baba K, Atsumi GI. Inhibition of plasminogen activator inhibitor-1 release from human endothelial cells by Angelica keiskei Koidzumi (Ashitaba) chalcones is structure-dependent. JOURNAL OF COMPLEMENTARY MEDICINE RESEARCH 2015; 4:355-7. [PMID: 26649241 PMCID: PMC4665031 DOI: 10.5455/jice.20150910123122] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2015] [Accepted: 08/25/2015] [Indexed: 11/03/2022]
Affiliation(s)
- Naoki Ohkura
- Department of Molecular Physiology and Pathology, School of Pharma-Sciences, Teikyo University, Itabashi, Tokyo, Japan
| | - Hiroaki Oiwa
- Department of Molecular Physiology and Pathology, School of Pharma-Sciences, Teikyo University, Itabashi, Tokyo, Japan
| | | | - Masahiko Taniguchi
- Division of Pharmacognosy, Osaka University of Pharmaceutical Sciences, Takatsuki, Osaka, Japan
| | - Kimiye Baba
- Division of Pharmacognosy, Osaka University of Pharmaceutical Sciences, Takatsuki, Osaka, Japan
| | - Gen-Ichi Atsumi
- Department of Molecular Physiology and Pathology, School of Pharma-Sciences, Teikyo University, Itabashi, Tokyo, Japan
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Abdullah Z, Rakkar K, Bath PMW, Bayraktutan U. Inhibition of TNF-α protects in vitro brain barrier from ischaemic damage. Mol Cell Neurosci 2015; 69:65-79. [PMID: 26546149 DOI: 10.1016/j.mcn.2015.11.003] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2015] [Revised: 09/11/2015] [Accepted: 11/02/2015] [Indexed: 12/11/2022] Open
Abstract
Cerebral ischaemia, associated with neuroinflammation and oxidative stress, is known to perturb blood-brain barrier (BBB) integrity and promote brain oedema formation. Using an in vitro model of human BBB composed of brain microvascular endothelial cells and astrocytes, this study examined whether suppression of TNF-α, a potent pro-inflammatory cytokine, might attenuate ischaemia-mediated cerebral barrier damage. Radical decreases in transendothelial electrical resistance and concomitant increases in paracellular flux across co-cultures exposed to increasing periods of oxygen-glucose deprivation alone (0.5-20 h) or followed by 20 h of reperfusion (OGD ± R) confirmed the deleterious effects of ischaemic injury on cerebral barrier integrity and function which concurred with reductions in tight junction protein (claudin-5 and occludin) expressions. OGD ± R elevated TNF-α secretion, NADPH oxidase activity, O2(-) production, actin stress fibre formation, MMP-2/9 activities and apoptosis in both endothelial cells and astrocytes. Increases in MMP-2 activity were confined to its extracellular isoform and treatments with OGD+R in astrocytes where MMP-9 could not be detected at all. Co-exposure of individual cell lines or co-cultures to an anti-TNF-α antibody dramatically diminished the extent of OGD ± R-evoked oxidative stress, morphological changes, apoptosis, MMP-2/9 activities while improving the barrier function through upregulation of tight junction protein expressions. In conclusion, vitiation of the exaggerated release of TNF-α may be an important therapeutic strategy in preserving cerebral integrity and function during and following a cerebral ischaemic attack.
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Affiliation(s)
- Zuraidah Abdullah
- Stroke, Division of Clinical Neuroscience, University of Nottingham, UK
| | - Kamini Rakkar
- Stroke, Division of Clinical Neuroscience, University of Nottingham, UK
| | - Philip M W Bath
- Stroke, Division of Clinical Neuroscience, University of Nottingham, UK
| | - Ulvi Bayraktutan
- Stroke, Division of Clinical Neuroscience, University of Nottingham, UK.
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MicroRNA-107 contributes to post-stroke angiogenesis by targeting Dicer-1. Sci Rep 2015; 5:13316. [PMID: 26294080 PMCID: PMC4543985 DOI: 10.1038/srep13316] [Citation(s) in RCA: 78] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2015] [Accepted: 07/21/2015] [Indexed: 01/27/2023] Open
Abstract
Previous studies have suggested that microRNA-107 (miR-107) regulates cell migration in tumor and promotes Hypoxia Inducible Factor 1α (HIF1α) regulated angiogenesis under hypoxia. We found that miR-107 was strongly expressed in ischemic boundary zone (IBZ) after permanent middle cerebral artery occlusion (pMCAO) in rats and inhibition of miR-107 could reduce capillary density in the IBZ after stroke. Such finding led us to hypothesize that miR-107 might regulate post-stroke angiogenesis and therefore serve as a therapeutic target. We also found that antagomir-107, a synthetic miR-107 inhibitor, decreased the number of capillaries in IBZ and increased overall infarct volume after pMCAO in rats. We demonstrated that miR-107 could directly down-regulate Dicer-1, a gene that encodes an enzyme essential for processing microRNA (miRNA) precursors. This resulted in translational desupression of VEGF (vascular endothelial growth factor) mRNA, thereby increasing expression of endothelial cell-derived VEGF (VEGF165/VEGF164), leading to angiogenesis after stroke. This process might be a protective mechanism for ischemia-induced cerebral injury and miR-107 might be used as a novel tool in stroke treatment.
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NADPH oxidase mediates TNF-α-evoked in vitro brain barrier dysfunction: roles of apoptosis and time. Mol Cell Neurosci 2014; 61:72-84. [PMID: 24907586 DOI: 10.1016/j.mcn.2014.06.002] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2014] [Revised: 05/20/2014] [Accepted: 06/02/2014] [Indexed: 11/20/2022] Open
Abstract
The pro-inflammatory cytokine TNF-α severely perturbs the integrity of the blood-brain barrier (BBB). This study explored the specific roles of NADPH oxidase and associated downstream effectors by using human brain microvascular endothelial cells (HBMECs) and human astrocytes (HAs), the key components of BBB, alone or in co-cultures to mimic human BBB. Exposure to TNF-α (6h) impaired BBB integrity as evidenced by marked decreases in transendothelial electrical resistance and concurrent increases in paracellular flux which appeared to subside with time (24h). Increased barrier dysfunction concurred with increases in endothelial NADPH oxidase activity, O2(-) production, actin stress fibre formation, MMP-2/9 activities and concomitant decreases in antioxidant (CuZn-SOD and catalase) and tight junction (claudin-5 and occludin) protein expressions. Conversely, TNF-α did not affect astrocytic MMP activities and antioxidant enzyme expressions. Unlike BBB damage, rates of HBMEC and HA apoptosis increased by time. Suppression of NADPH oxidase by apocynin or diphenyleneiodonium prevented TNF-α-evoked morphological changes and apoptosis, attenuated endothelial MMP activity and helped retain usual tight junction protein expression and barrier function. In conclusion, HBMECs constitute the main source of oxidative stress and basement-membrane degrading endopeptidases in inflammatory conditions associated with excessive release of TNF-α where targeting NADPH oxidase may prove extremely beneficial in maintaining proper barrier activity through prevention of cytoskeletal and tight junction reorganisations.
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Affiliation(s)
- Mark J Fisher
- From the Departments of Neurology, Anatomy & Neurobiology, and Pathology & Laboratory Medicine, UC Irvine School of Medicine, Irvine, CA
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Cho KS, Kwon KJ, Choi CS, Jeon SJ, Kim KC, Park JH, Ko HM, Lee SH, Cheong JH, Ryu JH, Han SH, Shin CY. Valproic acid induces astrocyte-dependent neurite outgrowth from cultured rat primary cortical neuron via modulation of tPA/PAI-1 activity. Glia 2013; 61:694-709. [PMID: 23378038 DOI: 10.1002/glia.22463] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2012] [Accepted: 12/20/2012] [Indexed: 01/31/2023]
Abstract
Tissue plasminogen activator (tPA) is expressed in several regions of brain and plays regulatory roles such as neurite outgrowth, synaptic plasticity and long term potentiation. The activity of tPA is regulated by an endogenous inhibitor plasminogen activator inhibitor-1 (PAI-1), which is expressed mainly in astrocytes. Valproic acid (VPA), a histone deacetylase inhibitor that is used for the treatment of epilepsy and bipolar disorders, promotes neurite extension, neuronal growth and has neuroprotective effect in neurodegenerative diseases. In this study, we examined whether the neurite extension effects of VPA is mediated by modulating tPA/PAI-1 system. VPA dose-dependently increased tPA activity and decreased PAI-1 activity in rat primary astrocytes but not in neurons. PAI-1 protein level secreted into the culture medium but not tPA per se was decreased by VPA. In co-culture system or in neuronal culture stimulated with astrocyte conditioned media but not in pure neuronal cell culture, VPA induced neurite outgrowth via increased tPA activity due to the decreased PAI-1 activity in astrocytes. The decrease in PAI-1 activity and increased neurite extension was regulated via JNK mediated post-transcriptional pathway. The essential role of tPA/PAI-1 system in the regulation of VPA-mediated neurite extension was further demonstrated by experiments using astrocyte conditioned media obtained from tPA or PAI-1 knockout mice. Regulation of PAI-1 activity in astrocyte by VPA may affect both physiological and pathological processes in brain by upregulating tPA activity.
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Affiliation(s)
- Kyu Suk Cho
- Department of Neuroscience, School of Medicine, Konkuk University, Seoul, Korea
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Astrocyte-derived sonic hedgehog contributes to angiogenesis in brain microvascular endothelial cells via RhoA/ROCK pathway after oxygen-glucose deprivation. Mol Neurobiol 2013; 47:976-87. [PMID: 23325464 DOI: 10.1007/s12035-013-8396-8] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2012] [Accepted: 01/02/2013] [Indexed: 10/27/2022]
Abstract
The human adult brain possesses intriguing plasticity, including neurogenesis and angiogenesis, which may be mediated by the activated sonic hedgehog (Shh). By employing a coculture system, brain microvascular endothelial cells (BMECs) cocultured with astrocytes, which were incubated under oxygen-glucose deprivation (OGD) condition, we tested the hypothesis that Shh secreted by OGD-activated astrocytes promotes cerebral angiogenesis following ischemia. The results of this study demonstrated that Shh was mainly secreted by astrocytes and the secretion was significantly upregulated after OGD. The proliferation, migration, and tube formation of BMECs cocultured with astrocytes after OGD were significantly enhanced, but cyclopamine (a Shh antagonist) or 5E1 (an antibody of Shh) reversed the change. Furthermore, silencing Ras homolog gene family, member A (RhoA) of BMECs by RNAi and blocking Rho-dependent kinase (ROCK) by Y27632, a specific antagonist of ROCK, suppressed the upregulation of proliferation, migration, and tube formation of BMECs after OGD. These findings suggested that Shh derived from activated astrocytes stimulated RhoA/ROCK pathway in BMECs after OGD, which might be involved in angiogenesis in vitro.
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Kim SY, Buckwalter M, Soreq H, Vezzani A, Kaufer D. Blood-brain barrier dysfunction-induced inflammatory signaling in brain pathology and epileptogenesis. Epilepsia 2012; 53 Suppl 6:37-44. [PMID: 23134494 PMCID: PMC3703535 DOI: 10.1111/j.1528-1167.2012.03701.x] [Citation(s) in RCA: 92] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The protection of the brain from blood-borne toxins, proteins, and cells is critical to the brain's normal function. Accordingly, a compromise in the blood-brain barrier (BBB) function accompanies many neurologic disorders, and is tightly associated with brain inflammatory processes initiated by both infiltrating leukocytes from the blood, and activation of glial cells. Those inflammatory processes contribute to determining the severity and prognosis of numerous neurologic disorders, and can both cause, and result from BBB dysfunction. In this review we examine the role of BBB and inflammatory responses, in particular activation of transforming grown factor β (TGFβ) signaling, in epilepsy, stroke, and Parkinson's disease.
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Affiliation(s)
- Soo Young Kim
- Department of Integrative Biology & Helen Wills Neuroscience Institute, UC Berkeley, Berkeley, California, U.S.A
| | - Marion Buckwalter
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, California, U.S.A
| | - Hermona Soreq
- The Edmond and Lily Safra Center for Brain Sciences and the Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Annamaria Vezzani
- Department of Neuroscience, Mario Negri Institute for Pharmacological Research, Milan, Italy
| | - Daniela Kaufer
- Department of Integrative Biology & Helen Wills Neuroscience Institute, UC Berkeley, Berkeley, California, U.S.A
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Teng H, Chopp M, Hozeska-Solgot A, Shen L, Lu M, Tang C, Zhang ZG. Tissue plasminogen activator and plasminogen activator inhibitor 1 contribute to sonic hedgehog-induced in vitro cerebral angiogenesis. PLoS One 2012; 7:e33444. [PMID: 22432023 PMCID: PMC3303815 DOI: 10.1371/journal.pone.0033444] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2011] [Accepted: 02/09/2012] [Indexed: 01/14/2023] Open
Abstract
The molecular mechanisms underlying cerebral angiogenesis have not been fully investigated. Using primary mouse brain endothelial cells (MBECs) and a capillary-like tube formation assay, we investigated whether the sonic hedgehog (Shh) signaling pathway is coupled with the plasminogen/plasmin system in mediating cerebral angiogenesis. We found that incubation of MBECs with recombinant human Shh (rhShh) substantially increased the tube formation in naïve MBECs. This was associated with increases in tissue plasminogen activator (tPA) activation and reduction of plasminogen activator inhibitor 1 (PAI-1). Blockage of the Shh pathway with cyclopamine abolished the induction of tube formation and the effect of rhShh on tPA and PAI-1. Addition of PAI-1 reduced rhShh-augmented tube formation. Genetic ablation of tPA in MBECs impaired tube formation and downregulated of vascular endothelial growth factor (VEGF) and angiopoietin 1 (Ang1). Addition of rhShh to tPA−/− MBECs only partially restored the tube formation and upregulated Ang1, but not VEGF, although rhShh increased VEGF and Ang1 expression on wild-type MBECs. Complete restoration of tube formation in tPA−/− MBECs was observed only when both exogenous Shh and tPA were added. The present study provides evidence that tPA and PAI-1 contribute to Shh-induced in vitro cerebral angiogenesis.
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Affiliation(s)
- Hua Teng
- Department of Neurology, Henry Ford Hospital, Detroit, Michigan, United States of America
| | - Michael Chopp
- Department of Neurology, Henry Ford Hospital, Detroit, Michigan, United States of America
- Department of Physics, Oakland University, Rochester, Michigan, United States of America
| | - Ann Hozeska-Solgot
- Department of Neurology, Henry Ford Hospital, Detroit, Michigan, United States of America
| | - Lihong Shen
- Department of Neurology, Henry Ford Hospital, Detroit, Michigan, United States of America
| | - Mei Lu
- Department of Biostatistics and Research Epidemiology, Henry Ford Hospital, Detroit, Michigan, United States of America
| | - Clark Tang
- Department of Neurology, Henry Ford Hospital, Detroit, Michigan, United States of America
| | - Zheng Gang Zhang
- Department of Neurology, Henry Ford Hospital, Detroit, Michigan, United States of America
- * E-mail:
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Yang F, Liu S, Wang SJ, Yu C, Paganini-Hill A, Fisher MJ. Tissue plasminogen activator expression and barrier properties of human brain microvascular endothelial cells. Cell Physiol Biochem 2011; 28:631-8. [PMID: 22178875 DOI: 10.1159/000335785] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/17/2011] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND Tissue plasminogen activator (tPA) regulates fibrinolysis and is routinely used as ischemic stroke pharmacotherapy. We hypothesized that brain microvascular tPA expression and barrier properties of endothelial cells are substantially related. METHODS Human brain microvascular endothelial cells were incubated with two agents known to modify cAMP pathways: forskolin and rolipram. We analyzed development of endothelial barrier properties, i.e., trans-endothelial electrical resistance (TEER), permeability of endothelial cell monolayer, expression of influx transporter glut-1 and endothelial tight junction molecules occludin and claudin-5, tPA antigen release, and levels of endothelial tPA mRNA. RESULTS Forskolin plus rolipram-treated endothelial cells showed increased TEER compared to controls (174±20% of control at day six, p<0.01), while permeability to albumin and 70kDa dextran was reduced (21±6.8% of control and 3.8±0.3% of control, respectively, p<0.001). In addition, occludin and claudin-5 protein were up-regulated, occludin mRNA was increased to 206±60% of control (p<0.05), glut-1 mRNA was increased to 196±68% of control (p<0.05), levels of tPA protein were reduced to 35±7.0% of control (p<0.001) after six days, and tPA mRNA was reduced to 32±7.7% of control (p<0.01). TPA and occludin mRNA levels were inversely associated (r=-0.68, p<0.05). CONCLUSIONS In this in vitro model, barrier properties were strongly linked (by inverse association) with tPA expression of brain microvascular endothelial cells.
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Affiliation(s)
- Fan Yang
- Departments of Neurology, University of California-Irvine, 101 The City Drive South, Orange, CA 92868, USA
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Xing C, Arai K, Park KP, Lo EH. Induction of vascular endothelial growth factor and matrix metalloproteinase-9 via CD47 signaling in neurovascular cells. Neurochem Res 2010; 35:1092-7. [PMID: 20364320 DOI: 10.1007/s11064-010-0159-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/17/2010] [Indexed: 01/15/2023]
Abstract
Neurovascular injury comprises a wide spectrum of pathophysiology that underlies the progression of brain injury after cerebral ischemia. Recently, it has been shown that activation of the integrin-associated protein CD47 mediates the development of blood-brain barrier injury and edema after cerebral ischemia. However, the mechanisms that mediate these complex neurovascular effects of CD47 remain to be elucidated. Here, we compare the effects of CD47 signaling in brain endothelial cells, astrocytes, and pericytes. Exposure to 4N1 K, a specific CD47-activating peptide derived from the major CD47 ligand thrombospondin-1, upregulated two major neurovascular mediators, vascular endothelial growth factor (VEGF) and matrix metalloproteinase-9 (MMP-9), in brain endothelial cells and astrocytes. No changes were detected in pericytes. These findings may provide a potential mechanism for CD47-induced changes in blood-brain barrier homeostasis, and further suggest that CD47 may be a relevant neurovascular target in stroke.
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Affiliation(s)
- Changhong Xing
- Neuroprotection Research Laboratory, Department of Radiology and Neurology, Massachusetts General Hospital, Harvard Medical School, MGH East, 149-2401, 13th St, Charlestown, MA 02129, USA
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Hultman K, Björklund U, Hansson E, Jern C. Potentiating effect of endothelial cells on astrocytic plasminogen activator inhibitor type-1 gene expression in an in vitro model of the blood–brain barrier. Neuroscience 2010; 166:408-15. [DOI: 10.1016/j.neuroscience.2010.01.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2009] [Revised: 12/10/2009] [Accepted: 01/03/2010] [Indexed: 10/20/2022]
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Lu TS, Avraham HK, Seng S, Tachado SD, Koziel H, Makriyannis A, Avraham S. Cannabinoids inhibit HIV-1 Gp120-mediated insults in brain microvascular endothelial cells. THE JOURNAL OF IMMUNOLOGY 2009; 181:6406-16. [PMID: 18941231 DOI: 10.4049/jimmunol.181.9.6406] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
HIV-1 infection has significant effect on the immune system as well as on the nervous system. Breakdown of the blood-brain barrier (BBB) is frequently observed in patients with HIV-associated dementia (HAD) despite lack of productive infection of human brain microvascular endothelial cells (HBMEC). Cellular products and viral proteins secreted by HIV-1 infected cells, such as the HIV-1 Gp120 envelope glycoprotein, play important roles in BBB impairment and HIV-associated dementia development. HBMEC are a major component of the BBB. Using cocultures of HBMEC and human astrocytes as a model system for human BBB as well as in vivo model, we show for the first time that cannabinoid agonists inhibited HIV-1 Gp120-induced calcium influx mediated by substance P and significantly decreased the permeability of HBMEC as well as prevented tight junction protein down-regulation of ZO-1, claudin-5, and JAM-1 in HBMEC. Furthermore, cannabinoid agonists inhibited the transmigration of human monocytes across the BBB and blocked the BBB permeability in vivo. These results demonstrate that cannabinoid agonists are able to restore the integrity of HBMEC and the BBB following insults by HIV-1 Gp120. These studies may lead to better strategies for treatment modalities targeted to the BBB following HIV-1 infection of the brain based on cannabinoid pharmacotherapies.
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Affiliation(s)
- Tzong-Shi Lu
- Division of Experimental Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA 02115, USA
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19
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Eisert WG, Schlachetzki F. Vascular endothelium and the blood-brain barrier. HANDBOOK OF CLINICAL NEUROLOGY 2008; 92:197-214. [PMID: 18790276 DOI: 10.1016/s0072-9752(08)01910-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Affiliation(s)
- Wolfgang G Eisert
- Center for Thrombosis and Atherosclerosis Research, University of Hanover, Hanover, Germany.
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20
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Frueh FW, Lesko LJ, Burckart GJ. Progress in the Direct Application of Pharmacogenomics to Patient Care: Sustaining innovation. Biomol Ther (Seoul) 2007. [DOI: 10.4062/biomolther.2007.15.1.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
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21
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Kim JW, Lee SY, Joo SH, Song MR, Shin CY. Beyond Clot Dissolution; Role of Tissue Plasminogen Activator in Central Nervous System. Biomol Ther (Seoul) 2007. [DOI: 10.4062/biomolther.2007.15.1.016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
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22
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Yang H, Liang Z, Li J, Cheng X, Luo N, Ju G. Optimized and efficient preparation of astrocyte cultures from rat spinal cord. Cytotechnology 2006; 52:87-97. [PMID: 19002867 PMCID: PMC3449418 DOI: 10.1007/s10616-006-9033-4] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2006] [Accepted: 10/13/2006] [Indexed: 10/23/2022] Open
Abstract
Astrocytes constitute a major class of glial cells in the CNS, and play crucial roles in physiological functioning, performance and maintenance of the CNS, as well as promotion of neuronal migration and maturation. Astrocytes have also been directly and indirectly implicated in the pathophysiology of various trauma occurrences, development of neurodegenerative diseases and nerve regeneration. To further understand mechanisms by which astrocytes elicit these effects, the first critical step in the study of astrocytes is the preparation of purified astrocytes cultures. Here we describe a simple and convenient procedure for producing rat primary astrocyte cultures of high purity, viability and proliferation. For astrocyte culture, we have optimized the isolation procedures and cultivation conditions including coating substrates, enzyme digestion, seeding density and composition of the culture medium. Using immunofluorescent antibodies against GFAP and OX-42 in combination of Hoechst 33342 fluorescent staining, we found that the purity of the astrocyte cultures was >99%. Astrocytes had high viability as measured by 3-(4, 5-dimethyl-2-yl)-2, 5-diphenyl-2H-tetrazolium bromide (MTT) assay. In addition, flow cytometric analysis was used to measure and observe variations in the cell cycle after 1-2 passages and proliferation of astrocytes was detected with a high percentage of cells stand in S+G(2)/M phase. Therefore, the method described here is ideal for experiments, which require highly pure astrocyte cultures.
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Affiliation(s)
- Hao Yang
- The Institute of Neuroscience, The Fourth Military Medical University, Xi’an, Shaanxi 710032 P.R. China
| | - Zhe Liang
- The Institute of Neuroscience, The Fourth Military Medical University, Xi’an, Shaanxi 710032 P.R. China
| | - Jingwen Li
- The Institute of Neuroscience, The Fourth Military Medical University, Xi’an, Shaanxi 710032 P.R. China
| | - Xiping Cheng
- The Institute of Neuroscience, The Fourth Military Medical University, Xi’an, Shaanxi 710032 P.R. China
| | - Na Luo
- The Institute of Neuroscience, The Fourth Military Medical University, Xi’an, Shaanxi 710032 P.R. China
| | - Gong Ju
- The Institute of Neuroscience, The Fourth Military Medical University, Xi’an, Shaanxi 710032 P.R. China
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23
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Fletcher NF, Brayden DJ, Brankin B, Worrall S, Callanan JJ. Growth and characterisation of a cell culture model of the feline blood–brain barrier. Vet Immunol Immunopathol 2006; 109:233-44. [PMID: 16182376 DOI: 10.1016/j.vetimm.2005.08.025] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2005] [Revised: 07/15/2005] [Accepted: 08/15/2005] [Indexed: 01/30/2023]
Abstract
An in vitro model of the feline blood-brain barrier was developed using primary cultures of brain capillary endothelial cells derived from adult cats. They were grown in the presence of astrocytes obtained from newborn kittens. Feline endothelial cell cultures were characterised by uptake of DiI-acetylated low-density lipoprotein (DiI-Ac-LDL) and expression of von Willebrand factor. Astrocytes were characterised based on their expression of glial fibrillary acidic protein (GFAP). Electron microscopy revealed junctional specialisation between endothelial cells. Occludin and ZO-1 expression by the endothelial cell cultures was detected by Western blot analysis. Barrier function of co-cultured endothelial cells and astrocytes was confirmed by a transendothelial electrical resistance (TEER) value of 30-35 Omegacm2 and apparent permeability coefficients (Papp) for FD-40 (FITC-dextran, 40 kDa) of 4x10(-6) cm/s and for FD-4 (4kDa) of 1.92x10(-5) cm/s. In endothelial cell monolayers grown with astrocyte-conditioned medium, the TEER value was lower (20-25 Omegacm2), and Papp of FD-40 and FD-4 was higher at 6.27x10(-6) and 3.96x10(-5) cm/s, respectively. This model should have useful applications in the examination of events occurring at the BBB early in FIV infection, and may provide knowledge applicable to HIV infection.
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Affiliation(s)
- Nicola F Fletcher
- Department of Veterinary Pathology, University College Dublin, Belfield, Dublin 4, Ireland.
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Abstract
Pericytes are known to regulate brain capillary endothelial functions. The purpose of this study was to define the hemostatic regulatory role of human brain pericytes. We used blood-brain barrier models consisting of human pericytes grown on transwell membrane inserts and cocultured with human brain microvascular endothelial cells (HBEC), or pericytes grown in direct contact with HBEC. When grown in cocultures in which pericytes were physically separated from endothelial cells, pericytes induced significant changes in endothelial tissue plasminogen activator (tPA) messenger ribonucleic acid (mRNA) and protein: tPA mRNA level was decreased in pericyte cocultures (52%+/-25% of monocultures, P < 0.05) and tPA protein level was decreased (66%+/-23% of monocultures, P < 0.05). Pericyte effects on endothelial fibrinolysis were enhanced when the two cell types were cocultured in direct contact, with tPA protein reduced in cocultures compared with monocultures (25%+/-15% of monocultures, P < 0.05). Endotoxin (lipopolysaccharide (LPS)), used as a standardized stimulus to define brain-specific inflammation-induced change, amplified pericyte-induced enhanced release of the tPA inhibitor plasminogen activator inhibitor-1 (PAI-1); the latter was released by endothelial cells first cocultured with pericytes and then incubated with LPS in the absence of pericytes. Pericytes (in contrast to endothelial cells and astrocytes) were found to be the principal in vitro source of the serpin protease nexin-1 (PN-1), known to have primarily antithrombin effects. These in vitro findings suggest that pericytes negatively regulate brain endothelial cell fibrinolysis, while pericyte expression of PN-1 may provide endogenous anticoagulant activity.
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Affiliation(s)
- Jeong Ai Kim
- Department of Neurology, University of California, Irvine, California, USA
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Cambier S, Gline S, Mu D, Collins R, Araya J, Dolganov G, Einheber S, Boudreau N, Nishimura SL. Integrin alpha(v)beta8-mediated activation of transforming growth factor-beta by perivascular astrocytes: an angiogenic control switch. THE AMERICAN JOURNAL OF PATHOLOGY 2005; 166:1883-94. [PMID: 15920172 PMCID: PMC1602409 DOI: 10.1016/s0002-9440(10)62497-2] [Citation(s) in RCA: 141] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Brain hemorrhage is a severe complication of both neoplastic and nonneoplastic brain disease. Mice deficient in the alpha(v)beta8 integrin display defective brain vessel formation resulting in hemorrhage and perinatal death, but the mechanism of brain hemorrhage is unknown. Because the alpha(v)beta8 integrin is expressed by astrocytes and not expressed by endothelium, paracrine interactions between astrocytes and endothelial cells could contribute to the maintenance of brain vessel integrity. We have investigated the mechanisms underlying astrocytic-endothelial paracrine signaling and have found that integrin-mediated activation of transforming growth factor (TGF)-beta by astrocytes influences endothelial cell function. Thus, we identified the integrin alpha(v)beta8 in human perivascular glial cell processes surrounding developing blood vessels. Human astrocytic alpha(v)beta8 was a major cell surface receptor for latent TGF-beta, and alpha(v)beta8-dependent activation of TGF-beta was the major mechanism of TGF-beta activation in primary cultures of astrocytes or freshly dissociated fetal brain cells. This activation of TGF-beta was sufficient to inhibit endothelial migration in fibrin gels and to alter expression of genes affecting proteolytic and angiogenic pathways. Taken together, our data suggest that astrocytic alpha(v)beta8 acts as a central regulator of brain vessel homeostasis through regulation of TGF-beta activation and expression of TGF-beta-responsive genes that promote vessel differentiation and stabilization, most notably plasminogen activator inhibitor-1 and thrombospondin-1.
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Affiliation(s)
- Stephanie Cambier
- Department of Pathology, University of California San Francisco, San Francisco, CA 94110, USA
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Kim JA, Tran ND, Zhou W, Fisher M. Dipyridamole enhances tissue plasminogen activator release by brain capillary endothelial cells. Thromb Res 2005; 115:435-8. [PMID: 15733978 DOI: 10.1016/j.thromres.2004.10.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2004] [Revised: 10/01/2004] [Accepted: 10/01/2004] [Indexed: 11/16/2022]
Affiliation(s)
- Jeong A Kim
- Department of Neurology, University of California, Irvine, Orange, CA 92868-5120, USA
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