101
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Lin CC, Lee IT, Chi PL, Hsieh HL, Cheng SE, Hsiao LD, Liu CJ, Yang CM. C-Src/Jak2/PDGFR/PKCδ-dependent MMP-9 induction is required for thrombin-stimulated rat brain astrocytes migration. Mol Neurobiol 2013; 49:658-72. [PMID: 24018979 DOI: 10.1007/s12035-013-8547-y] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2013] [Accepted: 08/27/2013] [Indexed: 12/15/2022]
Abstract
Among matrix metalloproteinases (MMPs), MMP-9 has been observed in patients with brain inflammatory diseases and may contribute to the pathology of brain diseases. Thrombin has been known as a regulator of MMP-9 expression and cells migration. However, the mechanisms underlying thrombin-induced MMP-9 expression in rat brain astrocytes (RBA-1 cells) were not completely understood. Here, we demonstrated that thrombin induced the expression of pro-form MMP-9 in RBA-1 cells and cells migration which were attenuated by pretreatment with the inhibitor of receptor tyrosine kinase (Genistein), c-Src (PP1), Jak2 (AG490), PDGFR (AG1296), PI3K (LY294002), Akt (SH-5), PKCs (Ro318220), PKCδ (Rottlerin), or NF-κB (Bay11-7082) and transfection with siRNA of c-Src, PDGFR, Akt, PKCδ, ATF2, p65, IKKα, or IKKβ. In addition, thrombin-stimulated c-Src, Jak2, or PDGFR phosphorylation was inhibited by a thrombin inhibitor (PPACK), PP1, AG490, or AG1296. Thrombin further stimulated c-Src and PDGFR complex formation in RBA-1 cells. Thrombin also stimulated Akt and PKCδ phosphorylation and PKCδ translocation which were reduced by PPACK, PP1, AG490, AG1296, or LY294002. We further observed that thrombin markedly stimulated ATF2 or IκBα phosphorylation and NF-κB p65 translocation which were inhibited by Rottlerin or LY294002. Finally, thrombin stimulated in vivo binding of p65 to the MMP-9 promoter, which was reduced by pretreatment with Rottlerin or LY294002. These results concluded that in RBA-1 cells, thrombin activated a c-Src/Jak2/PDGFR/PI3K/Akt/PKCδ pathway, which in turn triggered ATF2 and NF-κB activation and ultimately induced MMP-9 expression associated with cell migration.
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Affiliation(s)
- Chih-Chung Lin
- Department of Anesthetics, Chang Gung Memorial Hospital at Lin-Kou and College of Medicine, Chang Gung University, Kwei-Shan, Tao-Yuan, Taiwan
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102
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Birukova AA, Tian X, Tian Y, Higginbotham K, Birukov KG. Rap-afadin axis in control of Rho signaling and endothelial barrier recovery. Mol Biol Cell 2013; 24:2678-88. [PMID: 23864716 PMCID: PMC3756920 DOI: 10.1091/mbc.e13-02-0098] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
This study describes the novel role of Rap1 as a molecular switch for down-regulation of the Rho-dependent pathway of agonist-induced endothelial hyperpermeability. The Rho-Rap-Rac autoregulation loop may represent a fundamental mechanism of homeostasis and be critical for reestablishment of cell monolayer integrity in pathological conditions. Activation of the Rho GTPase pathway determines endothelial cell (EC) hyperpermeability after injurious stimuli. To date, feedback mechanisms of Rho down-regulation critical for barrier restoration remain poorly understood. We tested a hypothesis that Rho down-regulation and barrier recovery of agonist-stimulated ECs is mediated by the Ras family GTPase Rap1. Thrombin-induced EC permeability driven by rapid activation of the Rho GTPase pathway was followed by Src kinase–dependent phosphorylation of the Rap1-specific guanine nucleotide exchange factor (GEF) C3G, activation of Rap1, and initiation of EC barrier recovery. Knockdown experiments showed that Rap1 activation was essential for down-regulation of Rho signaling and actin stress fiber dissolution. Rap1 activation also enhanced interaction between adherens junction (AJ) proteins VE-cadherin and p120-catenin and stimulated AJ reannealing mediated by the Rap1 effector afadin. This mechanism also included Rap1-dependent membrane translocation of the Rac1-specific GEF Tiam1 and activation of Rac1-dependent peripheral cytoskeletal dynamics, leading to resealing of intercellular gaps. These data demonstrate that activation of the Rap1-afadin axis is a physiological mechanism driving restoration of barrier integrity in agonist-stimulated EC monolayers via negative-feedback regulation of Rho signaling, stimulation of actin peripheral dynamics, and reestablishment of cell–cell adhesive complexes.
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Affiliation(s)
- Anna A Birukova
- Department of Medicine, Section of Pulmonary and Critical Medicine, Lung Injury Center, University of Chicago, Chicago, IL 60637, USA
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103
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Thrombin Mediates Migration of Rat Brain Astrocytes via PLC, Ca2+, CaMKII, PKCα, and AP-1-Dependent Matrix Metalloproteinase-9 Expression. Mol Neurobiol 2013; 48:616-30. [DOI: 10.1007/s12035-013-8450-6] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2013] [Accepted: 03/25/2013] [Indexed: 12/21/2022]
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104
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Hossain MI, Roulston CL, Kamaruddin MA, Chu PWY, Ng DCH, Dusting GJ, Bjorge JD, Williamson NA, Fujita DJ, Cheung SN, Chan TO, Hill AF, Cheng HC. A truncated fragment of Src protein kinase generated by calpain-mediated cleavage is a mediator of neuronal death in excitotoxicity. J Biol Chem 2013; 288:9696-9709. [PMID: 23400779 DOI: 10.1074/jbc.m112.419713] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Excitotoxicity resulting from overstimulation of glutamate receptors is a major cause of neuronal death in cerebral ischemic stroke. The overstimulated ionotropic glutamate receptors exert their neurotoxic effects in part by overactivation of calpains, which induce neuronal death by catalyzing limited proteolysis of specific cellular proteins. Here, we report that in cultured cortical neurons and in vivo in a rat model of focal ischemic stroke, the tyrosine kinase Src is cleaved by calpains at a site in the N-terminal unique domain. This generates a truncated Src fragment of ~52 kDa, which we localized predominantly to the cytosol. A cell membrane-permeable fusion peptide derived from the unique domain of Src prevents calpain from cleaving Src in neurons and protects against excitotoxic neuronal death. To explore the role of the truncated Src fragment in neuronal death, we expressed a recombinant truncated Src fragment in cultured neurons and examined how it affects neuronal survival. Expression of this fragment, which lacks the myristoylation motif and unique domain, was sufficient to induce neuronal death. Furthermore, inactivation of the prosurvival kinase Akt is a key step in its neurotoxic signaling pathway. Because Src maintains neuronal survival, our results implicate calpain cleavage as a molecular switch converting Src from a promoter of cell survival to a mediator of neuronal death in excitotoxicity. Besides unveiling a new pathological action of Src, our discovery of the neurotoxic action of the truncated Src fragment suggests new therapeutic strategies with the potential to minimize brain damage in ischemic stroke.
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Affiliation(s)
- M Iqbal Hossain
- Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, 30 Flemington Road, Parkville, Victoria 3010, Australia
| | - Carli L Roulston
- O'Brien Institute, 42 Fitzroy Street, Fitzroy, Victoria 3065, Australia; Centre for Eye Research Australia, University of Melbourne, Gisborne Street, East Melbourne 3002, Australia
| | - M Aizuddin Kamaruddin
- Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, 30 Flemington Road, Parkville, Victoria 3010, Australia
| | - Percy W Y Chu
- Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, 30 Flemington Road, Parkville, Victoria 3010, Australia
| | - Dominic C H Ng
- Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, 30 Flemington Road, Parkville, Victoria 3010, Australia
| | - Gregory J Dusting
- O'Brien Institute, 42 Fitzroy Street, Fitzroy, Victoria 3065, Australia; Centre for Eye Research Australia, University of Melbourne, Gisborne Street, East Melbourne 3002, Australia
| | - Jeffrey D Bjorge
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Calgary, Health Sciences Centre, Calgary, Alberta T2N 4N1, Canada
| | - Nicholas A Williamson
- Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, 30 Flemington Road, Parkville, Victoria 3010, Australia
| | - Donald J Fujita
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Calgary, Health Sciences Centre, Calgary, Alberta T2N 4N1, Canada
| | - Steve N Cheung
- Centre for Cellular and Molecular Biology, School of Life and Environmental Sciences, Deakin University, Burwood, Victoria 3125, Australia
| | - Tung O Chan
- Department of Medicine, Center for Translational Medicine, Thomas Jefferson University, Philadelphia, Pennsylvania 19107
| | - Andrew F Hill
- Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, 30 Flemington Road, Parkville, Victoria 3010, Australia
| | - Heung-Chin Cheng
- Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, 30 Flemington Road, Parkville, Victoria 3010, Australia.
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105
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Abbott NJ, Friedman A. Overview and introduction: the blood-brain barrier in health and disease. Epilepsia 2013; 53 Suppl 6:1-6. [PMID: 23134489 DOI: 10.1111/j.1528-1167.2012.03696.x] [Citation(s) in RCA: 219] [Impact Index Per Article: 19.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
This article introduces the special issue on "Blood-Brain Barrier and Epilepsy." We review briefly current understanding of the structure and function of the blood-brain barrier (BBB), including its development and normal physiology, and ways in which it can be affected in pathology. The BBB formed by the endothelium of cerebral blood vessels is one of three main barrier sites protecting the central nervous system (CNS). The barrier is not a rigid structure, but a dynamic interface with a range of interrelated functions, resulting from extremely effective tight junctions, transendothelial transport systems, enzymes, and regulation of leukocyte permeation, which thereby generates the physical, transport, enzymatic, and immune regulatory functions of the BBB. The brain endothelial cells are important components of a "modular" structure, the neurovascular unit (NVU), with several associated cell types and extracellular matrix components. Modern methods have helped in identifying a range of proteins involved in barrier structure and function, and recent studies have revealed important stages, cell types, and signaling pathways important in BBB development. There is a growing list of CNS pathologies showing BBB dysfunction, with strong evidence that this can play a major role in certain disease etiologies. The articles that follow in this issue summarize in more detail reports and discussions of the recent international meeting on "BBB in Neurological Dysfunctions," which took place recently at Ben-Gurion University of the Negev Desert Campus (Beer-Sheva, Israel), focusing on the link between experimental and clinical studies, and the ways in which these lead to improved drug treatments.
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Affiliation(s)
- N Joan Abbott
- Institute of Pharmaceutical Science, Blood-Brain Barrier Group, King's College London, London, United Kingdom
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106
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Yokoo H, Chiba S, Tomita K, Takashina M, Sagara H, Yagisita S, Takano Y, Hattori Y. Neurodegenerative evidence in mice brains with cecal ligation and puncture-induced sepsis: preventive effect of the free radical scavenger edaravone. PLoS One 2012; 7:e51539. [PMID: 23236515 PMCID: PMC3517559 DOI: 10.1371/journal.pone.0051539] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2012] [Accepted: 11/07/2012] [Indexed: 02/08/2023] Open
Abstract
Sepsis is a major clinical challenge and septic encephalopathy is its nasty complication. The pathogenesis and underlying mechanisms of septic encephalopathy are not well understood. This study sought to fully characterize sepsis-associated biochemical and histopathological changes in brains of mice after cecal ligation and puncture, regarded as a highly clinically relevant animal model of polymicrobial sepsis. Real-time PCR analysis showed that gene expression levels of proinflammatory cytokines, including tumor necrosis factor-α and interleukin-1β, were significantly up-regulated in brain tissues from septic mice, but to a much lesser extent when compared with those in peripheral tissues such as lungs. Blood-brain barrier (BBB) permeability was significantly increased in septic mice, as determined by the measurement of sodium fluorescein and Evans blue content. Sepsis resulted in increases in NADPH oxidase activity and expression of p47phox and p67phox and up-regulation of inducible nitric oxide (NO) synthase in brains, indicating that superoxide, produced by NADPH oxidase, reacts with NO to form peroxynitrite, that maybe lead to the loss of BBB integrity. Light and electron microscopic examination of septic mouse brain showed serious neuronal degeneration, as indicated by hyperchromatic, shrunken, pyknotic, and electron-dense neurons. These histopathogical changes were prevented by treatment with the free radical scavenger edaravone. Together, these results suggest that sepsis can lead to rapid neurodegenerative changes in brains via free radical species production and possibly subsequent injury to the BBB. We may also provide a potentially useful therapeutic tool for treating septic encephalopathy.
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Affiliation(s)
- Hiroki Yokoo
- Department of Molecular and Medical Pharmacology, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama, Japan.
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107
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Whitney M, Savariar EN, Friedman B, Levin RA, Crisp JL, Glasgow HL, Lefkowitz R, Adams SR, Steinbach P, Nashi N, Nguyen QT, Tsien RY. Ratiometric Activatable Cell-Penetrating Peptides Provide Rapid In Vivo Readout of Thrombin Activation. Angew Chem Int Ed Engl 2012. [DOI: 10.1002/ange.201205721] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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108
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Whitney M, Savariar EN, Friedman B, Levin RA, Crisp JL, Glasgow HL, Lefkowitz R, Adams SR, Steinbach P, Nashi N, Nguyen QT, Tsien RY. Ratiometric activatable cell-penetrating peptides provide rapid in vivo readout of thrombin activation. Angew Chem Int Ed Engl 2012; 52:325-30. [PMID: 23080482 PMCID: PMC3694763 DOI: 10.1002/anie.201205721] [Citation(s) in RCA: 91] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2012] [Revised: 09/01/2012] [Indexed: 01/10/2023]
Affiliation(s)
- Michael Whitney
- Department of Pharmacology, UCSD School of Medicine, University of California San Diego, La Jolla, USA
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109
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Abstract
Mechanisms of ischemic neuronal and vascular injury remain obscure. Here we test the hypothesis that thrombin, a blood-borne coagulation factor, contributes to neurovascular injury during acute focal ischemia. Stroke was induced in adult Sprague Dawley rats by occluding the middle cerebral artery. Intra-arterial thrombin infusion during ischemia significantly increased vascular disruption and cellular injury. Intravenous infusion of argatroban, a direct thrombin inhibitor, alleviated neurovascular injury. Immunostaining showed thrombin on neurons in the ischemic core. Using an activatable cell-penetrating peptide engineered to detect thrombin activity, we discovered that thrombin proteolytic activity was specifically associated with neuronal damage during ischemia. Protease activated receptor-1, the presumptive thrombin receptor, appeared to mediate ischemic neurovascular injury. Furthermore, rats receiving thrombin during ischemia showed cognitive deficit, whereas rats receiving argatroban retained intact learning and memory. These results suggest a potential role for thrombin contributing to neurovascular injury and several potential avenues for neuroprotection.
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110
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Keep RF, Hua Y, Xi G. Intracerebral haemorrhage: mechanisms of injury and therapeutic targets. Lancet Neurol 2012; 11:720-31. [PMID: 22698888 DOI: 10.1016/s1474-4422(12)70104-7] [Citation(s) in RCA: 891] [Impact Index Per Article: 74.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Intracerebral haemorrhage accounts for about 10-15% of all strokes and is associated with high mortality and morbidity. No successful phase 3 clinical trials for this disorder have been completed. In the past 6 years, the number of preclinical and clinical studies focused on intracerebral haemorrhage has risen. Important advances have been made in animal models of this disorder and in our understanding of mechanisms underlying brain injury after haemorrhage. Several therapeutic targets have subsequently been identified that are now being pursued in clinical trials. Many clinical trials have been based on limited preclinical data, and guidelines to justify taking preclinical results to the clinic are needed.
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Affiliation(s)
- Richard F Keep
- Department of Neurosurgery, University of Michigan, Ann Arbor, MI 48109, USA.
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111
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Astrogliosis: a target for intervention in intracerebral hemorrhage? Transl Stroke Res 2012; 3:80-7. [PMID: 24323864 DOI: 10.1007/s12975-012-0165-x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2012] [Revised: 03/23/2012] [Accepted: 03/27/2012] [Indexed: 01/18/2023]
Abstract
Intracerebral hemorrhage (ICH) is a debilitating neurological injury, accounting for 10-15 % of all strokes. Despite neurosurgical intervention and supportive care, the 30-day mortality rate remains ~50 %, with ICH survivors frequently displaying neurological impairments and requiring long-term assisted care. Unfortunately, the lack of medical interventions to improve clinical outcomes has led to the notion that ICH is the least treatable form of stroke. Hence, additional studies are warranted to better understand the pathophysiology of ICH. Astrogliosis is an underlying astrocytic response to a wide range of brain injuries and postulated to have both beneficial and detrimental effects. However, the molecular mechanisms and functional roles of astrogliosis remain least characterized following ICH. Herein, we review the functional roles of astrogliosis in brain injuries and raise the prospects of therapeutically targeting astrogliosis after ICH.
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112
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Bodmer D, Vaughan KA, Zacharia BE, Hickman ZL, Connolly ES. The Molecular Mechanisms that Promote Edema After Intracerebral Hemorrhage. Transl Stroke Res 2012; 3:52-61. [PMID: 24323861 DOI: 10.1007/s12975-012-0162-0] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2012] [Revised: 03/19/2012] [Accepted: 03/21/2012] [Indexed: 01/01/2023]
Abstract
Intracerebral hemorrhage (ICH) is a devastating type of stroke with no effective therapies. Clinical advances in ICH treatment are limited by an incomplete understanding of the molecular mechanisms responsible for secondary injury and poor outcome. Increasing evidence suggests that cerebral edema is a major contributor to secondary injury and poor outcome in ICH. ICH activates specific signaling pathways that promote edema and damage neuronal tissue. By increasing our understanding of these pathways, we may be able to target them pharmaceutically to reduce edema in ICH patients. In this review, we focus on three major signaling pathways that promote edema after ICH: (1) the coagulation cascade and thrombin, (2) the inflammatory response and matrix metalloproteinases, and (3) the complement cascade and hemoglobin toxicity. We will describe the experimental evidence that confirms these pathways promote edema in ICH, discuss potential targets for new therapies, and comment on important directions for future research.
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Affiliation(s)
- Daniel Bodmer
- Department of Neurological Surgery, The Neurological Institute, Columbia University College of Physicians and Surgeons, New York, NY, 10032, USA
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113
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Liu DZ, Ander BP. Cell cycle inhibition without disruption of neurogenesis is a strategy for treatment of aberrant cell cycle diseases: an update. ScientificWorldJournal 2012; 2012:491737. [PMID: 22547985 PMCID: PMC3323905 DOI: 10.1100/2012/491737] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2011] [Accepted: 11/17/2011] [Indexed: 12/12/2022] Open
Abstract
Since publishing our earlier report describing a strategy for the treatment of central nervous system (CNS) diseases by inhibiting the cell cycle and without disrupting neurogenesis (Liu et al. 2010), we now update and extend this strategy to applications in the treatment of cancers as well. Here, we put forth the concept of "aberrant cell cycle diseases" to include both cancer and CNS diseases, the two unrelated disease types on the surface, by focusing on a common mechanism in each aberrant cell cycle reentry. In this paper, we also summarize the pharmacological approaches that interfere with classical cell cycle molecules and mitogenic pathways to block the cell cycle of tumor cells (in treatment of cancer) as well as to block the cell cycle of neurons (in treatment of CNS diseases). Since cell cycle inhibition can also block proliferation of neural progenitor cells (NPCs) and thus impair brain neurogenesis leading to cognitive deficits, we propose that future strategies aimed at cell cycle inhibition in treatment of aberrant cell cycle diseases (i.e., cancers or CNS diseases) should be designed with consideration of the important side effects on normal neurogenesis and cognition.
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Affiliation(s)
- Da-Zhi Liu
- Department of Neurology and the MIND Institute, University of California at Davis, Sacramento, CA 95817, USA.
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114
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Excitatory and Mitogenic Signaling in Cell Death, Blood-brain Barrier Breakdown, and BBB Repair after Intracerebral Hemorrhage. Transl Stroke Res 2012; 3:62-9. [PMID: 24323862 DOI: 10.1007/s12975-012-0147-z] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2012] [Revised: 02/18/2012] [Accepted: 02/22/2012] [Indexed: 02/06/2023]
Abstract
Intracerebral hemorrhage (ICH) results in the release of a large number of endogenous molecules, including glutamate, Ca(2+), ROS, thrombin, heme, iron, TNF-α, and others. These molecules participate in excitatory and mitogenic signaling transduction in which N-methyl-D-aspartate (NMDA) receptors and Src family kinases (SFKs) are implicated. Mitogenic signaling initiates the cell cycle for normal cell division of microglia and neural progenitor cells, whereas aberrant mitogenic signaling causes toxicity, killing neurons, astrocytes, and brain microvascular endothelial cells in neurological diseases including ICH. In this review, we summarize (1) how SFKs modulate NMDA receptors to kill neurons following ICH and (2) how SFKs modulate mitogenic signaling transduction to kill neurons and play a role in disrupting the blood-brain barrier (BBB) immediately following ICH and in repairing the BBB during the recovery phases weeks following ICH.
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115
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Alabanza LM, Bynoe MS. Thrombin induces an inflammatory phenotype in a human brain endothelial cell line. J Neuroimmunol 2012; 245:48-55. [PMID: 22381244 DOI: 10.1016/j.jneuroim.2012.02.004] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2011] [Revised: 01/20/2012] [Accepted: 02/06/2012] [Indexed: 12/31/2022]
Abstract
In this study, we utilized the human brain endothelial cell line, hCMEC/D3, to determine the effects of the coagulation factor, thrombin, on the human blood-brain barrier (BBB). We show that thrombin increased the mRNA and cell surface levels of ICAM-1 and VCAM-1 in hCMEC/D3 cells. Thrombin similarly upregulated several chemokines implicated in human neurological conditions. Additionally, the paracellular permeability of the human BBB in vitro was also increased following thrombin treatment. Overall, this study demonstrates that thrombin can effectively induce an inflamed phenotype in an in vitro human BBB.
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Affiliation(s)
- Leah M Alabanza
- Department of Microbiology and Immunology, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853, USA
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116
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Thrombin in Ischemic Stroke Targeting. Transl Stroke Res 2012. [DOI: 10.1007/978-1-4419-9530-8_9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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117
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Lapchak PA. Identifying Vascular Targets to Treat Hemorrhagic Stroke. Transl Stroke Res 2012. [DOI: 10.1007/978-1-4419-9530-8_2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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118
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Chen-Roetling J, Liu W, Regan RF. Iron accumulation and neurotoxicity in cortical cultures treated with holotransferrin. Free Radic Biol Med 2011; 51:1966-74. [PMID: 21939754 PMCID: PMC3345563 DOI: 10.1016/j.freeradbiomed.2011.08.021] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/18/2011] [Revised: 08/19/2011] [Accepted: 08/22/2011] [Indexed: 01/13/2023]
Abstract
Nonheme iron accumulates in CNS tissue after ischemic and hemorrhagic insults and may contribute to cell loss. The source of this iron has not been precisely defined. After blood-brain barrier disruption, CNS cells may be exposed to plasma concentrations of transferrin-bound iron (TBI), which exceed that in the CSF by over 50-fold. In this study, the hypothesis that these concentrations of TBI produce cell iron accumulation and neurotoxicity was tested in primary cortical cultures. Treatment with 0.5-3mg/ml holotransferrin for 24h resulted in the loss of 20-40% of neurons, associated with increases in malondialdehyde, ferritin, heme oxygenase-1, and iron; transferrin receptor-1 expression was reduced by about 50%. Deferoxamine, 2,2'-bipyridyl, Trolox, and ascorbate prevented all injury, but apotransferrin was ineffective. Cell TBI accumulation was significantly reduced by deferoxamine, 2,2'-bipyridyl, and apotransferrin, but not by ascorbate or Trolox. After treatment with (55)Fe-transferrin, approximately 40% of cell iron was exported within 16h. Net export was increased by deferoxamine and 2,2'-bipyridyl, but not by apotransferrin. These results suggest that downregulation of transferrin receptor-1 expression is insufficient to prevent iron-mediated death when neurons are exposed to plasma concentrations of TBI. Chelator therapy may be beneficial for acute CNS injuries associated with loss of blood-brain barrier integrity.
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Affiliation(s)
| | | | - Raymond F. Regan
- Corresponding Author: Department of Emergency Medicine, Thomas Jefferson University, 1025 Walnut Street, College Building Room 813, Philadelphia, PA 19107, Telephone: 215-955-2695; FAX: 215-923-6225
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119
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Liu DZ, Sharp FR. The dual role of SRC kinases in intracerebral hemorrhage. ACTA NEUROCHIRURGICA. SUPPLEMENT 2011; 111:77-81. [PMID: 21725735 DOI: 10.1007/978-3-7091-0693-8_13] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Src kinase signaling has been implicated in multiple mechanisms of intracerebral hemorrhage (ICH). These include (1) thrombin-mediated mitogenic stress, (2) excitatory amino acid (AA)-mediated excitatory toxicity, (3) vascular endothelial growth factor (VEGF) and matrix metalloproteinases (MMPs)-mediated changes of vascular permeability, (4) cytokines-mediated inflammatory responses, and (5) others. These work together after ICH, causing brain injuries in the acute stage and self-repair in the recovery stage. We found that acute administration of the Src inhibitor, PP2, blocks the blood-brain barrier (BBB) breakdown and brain edema that occurs after ICH. However, delayed and chronic administration of PP2 prevents the BBB repair and edema resolution after ICH. These results led us to suggest that the two contradictory findings share the same principles at least in part via activation of Src kinases in acute or recovery stages after ICH. Acute Src kinase activation after ICH leads to BBB damage, and chronic Src kinase activation after ICH leads to BBB repair.
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Affiliation(s)
- Da-Zhi Liu
- Department of Neurology and the MIND Institute, University of California at Davis Medical Center, Sacramento, CA 95817, USA.
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120
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Lapchak PA, Wu Q. Vascular Dysfunction in Brain Hemorrhage: Translational Pathways to Developing New Treatments from Old Targets. JOURNAL OF NEUROLOGY & NEUROPHYSIOLOGY 2011; 2011:S1-e001. [PMID: 22400125 PMCID: PMC3293216 DOI: 10.4172/2155-9562.s1-e001] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Hemorrhagic stroke which is a form of stroke that affects 20% of all stroke patients is a devastating condition for which new treatments must be developed. Current treatment methods are quite insufficient to reduce long term morbidity and high mortality rate, up to 50%, associated with bleeding into critical brain structures, into ventricular spaces and within the subarachnoid space. During the last 10-15 years, significant advances in the understanding of important mechanisms that contribute to cell death and clinical deficits have been made. The most important observations revolve around a key set of basic mechanisms that are altered in brain bleeding models, including activation of membrane metalloproteinases, oxidative stress and both inflammatory and coagulation pathways. Moreover, it is now becoming apparent that brain hemorrhage can activate the ischemic stroke cascade in neurons, glial cells and the vascular compartment. The activation of multiple pathways allows comes the opportunity to intervene pharmacologically using monotherapy or combination therapy. Ultimately, combination therapy or pleiotropic compounds with multi-target activities should prove to be more efficacious than any single therapy alone. This article provides a comprehensive look at possible targets for small molecule intervention as well as some new approaches that result in metabolic down-regulation or inhibition of multiple pathways simultaneously.
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Affiliation(s)
- Paul A. Lapchak
- Director of Translational Research, Cedars-Sinai Medical Center, Department of Neurology, Davis Research Building, D- 2091, 110 N, George Burns Road, Los Angeles, CA 90048 USA
| | - Qiang Wu
- Project Scientist, Cedars-Sinai Medical Center, Department of Neurology, Davis Research Building, D-2094E, 110 N. George Burns Road, Los Angeles, CA 90048 USA
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Katsuki H. Exploring neuroprotective drug therapies for intracerebral hemorrhage. J Pharmacol Sci 2010; 114:366-78. [PMID: 21081835 DOI: 10.1254/jphs.10r05cr] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Intracerebral hemorrhage (ICH) is a devastating neurological disorder with high mortality and poor prognosis, for which virtually no effective drug therapies are available at present. Experimental animal models, based on intrastriatal injection of collagenase or autologous blood, have enabled great advances in elucidation of cellular/molecular events contributing to brain pathogenesis associated with ICH. Many lines of evidence indicate that blood constituents, including hemoglobin-derived products as well as proteases such as thrombin, play important roles in the pathogenic events. Inflammatory reactions involving neutrophils, activated microglia, and production of proinflammatory cytokines also constitute a critical aspect of pathology leading to neurodegeneration and tissue damage. Efforts are continuing to find drugs that potentially alleviate pathological and neurological outcomes of ICH. Various drugs that possess antioxidative, anti-inflammatory or neurotrophic/neuroprotective properties have been demonstrated to produce therapeutic effects on ICH animal models. Drugs already in clinical use such as minocycline, statins, and several nuclear receptor ligands are among the list of effective drugs, but whether they also show therapeutic efficacy in human ICH patients remains unproven. Here, current knowledge of ICH pathogenesis and problems arising with respect to exploration of new drug candidates are discussed.
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Affiliation(s)
- Hiroshi Katsuki
- Department of Chemico-Pharmacological Sciences, Graduate School of Pharmaceutical Sciences, Kumamoto University, 5-1 Oe-honmachi, Kumamoto 862-0973, Japan.
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Cardiac arrest-induced regional blood-brain barrier breakdown, edema formation and brain pathology: a light and electron microscopic study on a new model for neurodegeneration and neuroprotection in porcine brain. J Neural Transm (Vienna) 2010; 118:87-114. [PMID: 20963453 DOI: 10.1007/s00702-010-0486-4] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2010] [Accepted: 08/30/2010] [Indexed: 12/23/2022]
Abstract
Brief cardiac arrest and survival is often associated with marked neurological alterations related to cognitive and sensory motor functions. However, detail studies using selective vulnerability of brain after cardiac arrest in animal models are still lacking. We examined selective vulnerability of five brain regions in our well-established cardiac arrest model in pigs. Using light and electron microscopic techniques in combinations with immunohistochemistry, we observed that 5, 30, 60 and 180 min after cardiac arrest results in progressive neuronal damage that was most marked in the thalamus followed by cortex, hippocampus, hypothalamus and the brain stem. The neuronal damages are largely evident in the areas showing leakage of serum albumin in the neuropil. Furthermore, a tight correlation was seen between neuronal damage and increase in brain water content and Na(+) indicating vasogenic edema formation after cardiac arrest. Damage to myelinated fibers and loss of myelin as seen using Luxol fast blue and myelin basic protein (MBP) immunoreactivity is clearly evident in the brain areas exhibiting neuronal damage. Upregulation of GFAP positive astrocytes closely corresponds with neuronal damages in different brain areas after cardiac arrest. At the ultrastructural level, perivascular edema together with neuronal, glial and endothelia cell damages is frequent in the brain areas showing albumin leakage. Damage to both pre- and post-synaptic membrane is also common. Treatment with methylene blue, an antioxidant markedly reduced neuronal damage, leakage of albumin, overexpression of GFAP and damage to myelin following cardiac arrest. Taken together, these observations suggest that (a) cardiac arrest is capable to induce selective neuronal, glial and myelin damage in different parts of the pig brain, and (b) antioxidant methylene blue is capable to induce neuroprotection by reducing BBB disruption. These observations strongly suggest that the model could be used to explore new therapeutic agents to enhance neurorepair following cardiac arrest-induced brain damage for therapeutic purposes.
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Liu DZ, Ander BP, Sharp FR. Cell cycle inhibition without disruption of neurogenesis is a strategy for treatment of central nervous system diseases. Neurobiol Dis 2009; 37:549-57. [PMID: 19944161 DOI: 10.1016/j.nbd.2009.11.013] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2009] [Revised: 11/10/2009] [Accepted: 11/18/2009] [Indexed: 12/12/2022] Open
Abstract
Classically, the cell cycle is regarded as the process leading to cellular proliferation. However, increasing evidence over the last decade supports the notion that neuronal cell cycle re-entry results in post-mitotic death. A mature neuron that re-enters the cell cycle can neither advance to a new G0 quiescent state nor revert to its earlier G0 state. This presents a critical dilemma to the neuron from which death may be an unavoidable but necessary outcome for adult neurons attempting to complete the cell cycle. In contrast, tumor cells that undergo aberrant cell cycle re-entry divide and can survive. Thus, cell cycle inhibition strategies are of interest in cancer treatment but may also represent an important means of protecting neurons. In this review, we put forth the concept of the "expanded cell cycle" and summarize the cell cycle proteins, signal transduction events and mitogenic molecules that can drive a neuron into the cell cycle in various CNS diseases. We also discuss the pharmacological approaches that interfere with the mitogenic pathways and prevent mature neurons from attempting cell cycle re-entry, protecting them from cell death. Lastly, future attempts at blocking the cell cycle to rescue mature neurons from injury should be designed so as to not block normal neurogenesis.
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Affiliation(s)
- Da-Zhi Liu
- Department of Neurology and the M.I.N.D. Institute, University of California at Davis, Sacramento, CA 95817, USA.
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