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Bömers JP, Holm A, Kazantzi S, Edvinsson L, Mathiesen TI, Haanes KA. Protein kinase C-inhibition reduces critical weight loss and improves functional outcome after experimental subarachnoid haemorrhage. J Stroke Cerebrovasc Dis 2024; 33:107728. [PMID: 38643942 DOI: 10.1016/j.jstrokecerebrovasdis.2024.107728] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2023] [Revised: 04/15/2024] [Accepted: 04/18/2024] [Indexed: 04/23/2024] Open
Abstract
OBJECTIVES Subarachnoid haemorrhage (SAH) carries a high burden of morbidity and mortality. One in three patients develop vasospasm, which is associated with Delayed Cerebral Ischemia. The pathophysiology includes vasoconstrictor receptor upregulation in cerebral arteries. The protein kinase C - inhibitor RO-31-7549 reduces the expression of several vasoconstrictor receptors and normalizes cerebral blood flow in experimental SAH but functional and behavioural effects are unknown. This study was undertaken to analyse functional outcomes up to 14 days after experimental SAH. MATERIALS AND METHODS 54 male rats were randomised to experimental SAH or sham, using the pre-chiasmatic, single injection model, and subsequent treatment or vehicle. 42 remained for final analysis. The animals were euthanized on day 14 or when reaching a humane endpoint. The primary endpoint was overall survival, defined as either spontaneous mortality or when reaching a predefined humane endpoint. The secondary outcomes were differences in the rotating pole test, weight, open field test, novel object recognition and qPCR of selected inflammatory markers. RESULTS In the vehicle group 6/15 rats reached the humane endpoint of >20 % weight loss compared to 1/14 in the treatment group. This resulted in a significant reduced risk of early euthanasia due to >20 % weight loss of HR 0.15 (0.03-0.66, p = 0.04). Furthermore, the treatment group did significantly better on the rotating pole test, RR 0.64 (0.47-0.91, p = 0.02). CONCLUSION RO-31-7549 improved outcomes in terms >20 % weight loss and rotating pole performance after experimental SAH and could be investigated.
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Affiliation(s)
- Jesper P Bömers
- Department of Neurosurgery, Copenhagen University Hospital - Rigshospitalet, Copenhagen, Denmark; Clinical Experimental Research Unit, Translational Research Centre, Copenhagen University Hospital - Rigshospitalet, Glostrup, Denmark.
| | - Anja Holm
- Clinical Experimental Research Unit, Translational Research Centre, Copenhagen University Hospital - Rigshospitalet, Glostrup, Denmark; Center for RNA Medicine, Aalborg University, Copenhagen, Denmark
| | - Spyridoula Kazantzi
- Clinical Experimental Research Unit, Translational Research Centre, Copenhagen University Hospital - Rigshospitalet, Glostrup, Denmark
| | - Lars Edvinsson
- Clinical Experimental Research Unit, Translational Research Centre, Copenhagen University Hospital - Rigshospitalet, Glostrup, Denmark; Department of Clinical Sciences, Lund University, Lund, Sweden
| | - Tiit I Mathiesen
- Department of Neurosurgery, Copenhagen University Hospital - Rigshospitalet, Copenhagen, Denmark; Department of Clinical Medicine, University of Copenhagen, Copenhagen, Denmark; Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Kristian A Haanes
- Clinical Experimental Research Unit, Translational Research Centre, Copenhagen University Hospital - Rigshospitalet, Glostrup, Denmark; Department of Biology, University of Copenhagen, Copenhagen, Denmark
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Edvinsson L, Krause DN. Switching Off Vascular MAPK Signaling: A Novel Strategy to Prevent Delayed Cerebral Ischemia Following Subarachnoid Hemorrhage. Transl Stroke Res 2024:10.1007/s12975-024-01234-z. [PMID: 38334872 DOI: 10.1007/s12975-024-01234-z] [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: 12/10/2023] [Revised: 01/12/2024] [Accepted: 02/01/2024] [Indexed: 02/10/2024]
Abstract
Patients who initially survive the rupture and repair of a brain aneurysm often take a devastating turn for the worse some days later and die or suffer permanent neurologic deficits. This catastrophic sequela is attributed to a delayed phase of global cerebral ischemia (DCI) following aneurysmal subarachnoid hemorrhage (aSAH), but we lack effective treatment. Here we present our view, based on 20 years of research, that the initial drop in blood flow at the time of rupture triggers genomic responses throughout the brain vasculature that manifest days later as increased vasoconstriction and decreased cerebral blood flow. We propose a novel treatment strategy to prevent DCI by early inhibition of the vascular mitogen-activated protein kinase (MAPK) pathway that triggers expression of vasoconstrictor and inflammatory mediators. We summarize evidence from experimental SAH models showing early treatment with MAPK inhibitors "switches off" these detrimental responses, maintains flow, and improves neurological outcome. This promising therapy is currently being evaluated in clinical trials.
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Affiliation(s)
- Lars Edvinsson
- Division of Experimental Vascular Research, Department of Clinical Sciences, Lund University, Sölvegatan 19, 22100, Lund, Sweden.
- Department of Experimental Research, Glostrup Research Institute, CopenhagenUniversity, Copenhagen, Denmark.
| | - Diana N Krause
- Division of Experimental Vascular Research, Department of Clinical Sciences, Lund University, Sölvegatan 19, 22100, Lund, Sweden
- Department of Pharmaceutical Sciences, SchoolofPharmacy&PharmaceuticalSciences, University of California at Irvine, Irvine, CA, USA
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3
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Becker K. Animal Welfare Aspects in Planning and Conducting Experiments on Rodent Models of Subarachnoid Hemorrhage. Cell Mol Neurobiol 2023; 43:3965-3981. [PMID: 37861870 DOI: 10.1007/s10571-023-01418-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Accepted: 09/18/2023] [Indexed: 10/21/2023]
Abstract
Subarachnoid hemorrhage is an acute life-threatening cerebrovascular disease with high socio-economic impact. The most frequent cause, the rupture of an intracerebral aneurysm, is accompanied by abrupt changes in intracerebral pressure, cerebral perfusion pressure and, consequently, cerebral blood flow. As aneurysms rupture spontaneously, monitoring of these parameters in patients is only possible with a time delay, upon hospitalization. To study alterations in cerebral perfusion immediately upon ictus, animal models are mandatory. This article addresses the points necessarily to be included in an animal project proposal according to EU directive 2010/63/EU for the protection of animals used for scientific purposes and herewith offers an insight into animal welfare aspects of using rodent models for the investigation of cerebral perfusion after subarachnoid hemorrhage. It compares surgeries, model characteristics, advantages, and drawbacks of the most-frequently used rodent models-the endovascular perforation model and the prechiasmatic and single or double cisterna magna injection model. The topics of discussing anesthesia, advice on peri- and postanesthetic handling of animals, assessing the severity of suffering the animals undergo during the procedure according to EU directive 2010/63/EU and weighing the use of these in vivo models for experimental research ethically are also presented. In conclusion, rodent models of subarachnoid hemorrhage display pathophysiological characteristics, including changes of cerebral perfusion similar to the clinical situation, rendering the models suited to study the sequelae of the bleeding. A current problem is low standardization of the models, wherefore reporting according to the ARRIVE guidelines is highly recommended. Animal welfare aspects of rodent models of subarachnoid hemorrhage. Rodent models for investigation of cerebral perfusion after subarachnoid hemorrhage are compared regarding surgeries and model characteristics, and 3R measures are suggested. Anesthesia is discussed, and advice given on peri- and postanesthetic handling. Severity of suffering according to 2010/63/EU is assessed and use of these in vivo models weighed ethically.
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Affiliation(s)
- Katrin Becker
- Institute for Translational Neurosurgery, Medical Faculty, RWTH Aachen University, 52074, Aachen, Germany.
- Institute for Cardiovascular Sciences, University Hospital Bonn, 53127, Bonn, Germany.
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Chu MC, Mao WC, Wu HF, Chang YC, Lu TI, Lee CW, Chung YJ, Hsieh TH, Chang HS, Chen YF, Lin CH, Tang CW, Lin HC. Transient plasticity response is regulated by histone deacetylase inhibitor in oxygen-glucose deprivation condition. Pharmacol Rep 2023; 75:1200-1210. [PMID: 37695500 DOI: 10.1007/s43440-023-00525-w] [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: 06/01/2023] [Revised: 08/25/2023] [Accepted: 08/25/2023] [Indexed: 09/12/2023]
Abstract
BACKGROUND The pathological form of synaptic plasticity, ischemic long-term potentiation (iLTP), induced by oxygen and glucose deprivation (OGD), is implicated in the acute phase of stroke with the potentiation of N-methyl-D-aspartate receptor (NMDAR). While there has been widespread attention on the excitatory system, a recent study reported that γ-aminobutyric acid (GABA)ergic system is also involved in iLTP. Valproic acid (VPA), a histone deacetylase inhibitor, protects against ischemic damage. However, whether VPA regulates early phase plasticity in ischemic stroke remains unknown. The present study aims to investigate the potential role and mechanism of VPA in ischemic stroke. METHODS A brief exposure of OGD on the hippocampal slices and the induction of photothrombotic ischemia (PTI) were used as ex vivo and in vivo models of ischemic stroke, respectively. RESULTS Using extracellular recordings, iLTP was induced in the hippocampal Schaffer collateral pathway following OGD exposure. VPA treatment abolished hippocampal iLTP via GABAA receptor enhancement and extracellular signal-regulated kinase (ERK) phosphorylation. Administration of VPA reduced brain infarct volume and motor dysfunction in mice with PTI. Moreover, VPA protected against ischemic injury by upregulating the GABAergic system and ERK phosphorylation, as well as by reducing of matrix metalloproteinase in a PTI-induced ischemic stroke model. CONCLUSIONS Together, this study revealed the protection of VPA in ex vivo OGD-induced pathological form of neuroplasticity and in vivo PTI-induced brain damage and motor dysfunction through rescuing GABAergic deficiency and the pathological hallmarks of ischemia.
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Affiliation(s)
- Ming-Chia Chu
- Department and Institute of Physiology, College of Medicine, National Yang Ming Chiao Tung University, Taipei, Taiwan
| | - Wei-Chang Mao
- Department of Psychiatry, Cheng-Hsin General Hospital, Taipei, Taiwan
| | - Han-Fang Wu
- Department of Optometry, MacKay Medical College, New Taipei City, Taiwan
| | - Yun-Chi Chang
- Department and Institute of Physiology, College of Medicine, National Yang Ming Chiao Tung University, Taipei, Taiwan
| | - Ting-I Lu
- Department and Institute of Physiology, College of Medicine, National Yang Ming Chiao Tung University, Taipei, Taiwan
| | - Chi-Wei Lee
- Department and Institute of Physiology, College of Medicine, National Yang Ming Chiao Tung University, Taipei, Taiwan
| | - Yueh-Jung Chung
- Department and Institute of Physiology, College of Medicine, National Yang Ming Chiao Tung University, Taipei, Taiwan
| | - Tsung-Han Hsieh
- Department and Institute of Physiology, College of Medicine, National Yang Ming Chiao Tung University, Taipei, Taiwan
| | - Hsun-Shuo Chang
- School of Pharmacy, College of Pharmacy, Kaoshiung Medical University, Kaoshiung, Taiwan
| | - Yih-Fung Chen
- School of Pharmacy, College of Pharmacy, Kaoshiung Medical University, Kaoshiung, Taiwan
- Graduate Institute of Natural Products, College of Pharmacy, Kaoshiung Medical University, Kaoshiung, Taiwan
| | - Chia-Hsien Lin
- Department of Health Industry Management, Kainan University, Taoyuan, Taiwan
| | - Chih-Wei Tang
- Department of Neurology, Far Eastern Memorial Hospital, New Taipei City, Taiwan.
| | - Hui-Ching Lin
- Department and Institute of Physiology, College of Medicine, National Yang Ming Chiao Tung University, Taipei, Taiwan.
- Brain Research Center, National Yang Ming Chiao Tung University, Taipei, Taiwan.
- Ph.D. Program in Medical Neuroscience, College of Medical Science and Technology, Taipei Medical University and National Health Research Institute, Taipei, Taiwan.
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Bömers JP, Grell AS, Edvinsson L, Johansson SE, Haanes KA. The MEK Inhibitor Trametinib Improves Outcomes following Subarachnoid Haemorrhage in Female Rats. Pharmaceuticals (Basel) 2022; 15:ph15121446. [PMID: 36558896 PMCID: PMC9785726 DOI: 10.3390/ph15121446] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2022] [Revised: 11/18/2022] [Accepted: 11/19/2022] [Indexed: 11/23/2022] Open
Abstract
Aneurysmal subarachnoid haemorrhage (SAH) is a haemorrhagic stroke that causes approximately 5% of all stroke incidents. We have been working on a treatment strategy that targets changes in cerebrovascular contractile receptors, by blocking the MEK/ERK1/2 signalling pathway. Recently, a positive effect of trametinib was found in male rats, but investigations of both sexes in pre-clinical studies are an important necessity. In the current study, a SAH was induced in female rats, by autologous blood-injection into the pre-chiasmatic cistern. This produces a dramatic, transient increase in intracranial pressure (ICP) and an acute and prolonged decrease in cerebral blood flow. Rats were then treated with either vehicle or three doses of 0.5 mg/kg trametinib (specific MEK/ERK1/2 inhibitor) intraperitoneally at 3, 9, and 24 h after the SAH. The outcome was assessed by a panel of tests, including intracranial pressure (ICP), sensorimotor tests, a neurological outcome score, and myography. We observed a significant difference in arterial contractility and a reduction in subacute increases in ICP when the rats were treated with trametinib. The sensory motor and neurological outcomes in trametinib-treated rats were significantly improved, suggesting that the improved outcome in females is similar to that of males treated with trametinib.
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Affiliation(s)
- Jesper Peter Bömers
- Department of Clinical Experimental Research, Glostrup Research Institute, Copenhagen University Hospital—Rigshospitalet, Nordstjernevej 42, DK-2600 Glostrup, Denmark
- Department of Neurosurgery, Copenhagen University Hospital—Rigshospitalet, Blegdamsvej 9, DK-2100 Copenhagen, Denmark
| | - Anne-Sofie Grell
- Department of Clinical Experimental Research, Glostrup Research Institute, Copenhagen University Hospital—Rigshospitalet, Nordstjernevej 42, DK-2600 Glostrup, Denmark
| | - Lars Edvinsson
- Department of Clinical Experimental Research, Glostrup Research Institute, Copenhagen University Hospital—Rigshospitalet, Nordstjernevej 42, DK-2600 Glostrup, Denmark
- Department of Clinical Sciences, Division of Experimental Vascular Research, Lund University, 221 84 Lund, Sweden
| | - Sara Ellinor Johansson
- Department of Clinical Experimental Research, Glostrup Research Institute, Copenhagen University Hospital—Rigshospitalet, Nordstjernevej 42, DK-2600 Glostrup, Denmark
| | - Kristian Agmund Haanes
- Department of Clinical Experimental Research, Glostrup Research Institute, Copenhagen University Hospital—Rigshospitalet, Nordstjernevej 42, DK-2600 Glostrup, Denmark
- Correspondence:
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Schwarting J, Nehrkorn K, Liu H, Plesnila N, Terpolilli NA. Role of Pial Microvasospasms and Leukocyte Plugging for Parenchymal Perfusion after Subarachnoid Hemorrhage Assessed by In Vivo Multi-Photon Microscopy. Int J Mol Sci 2021; 22:8444. [PMID: 34445151 PMCID: PMC8395146 DOI: 10.3390/ijms22168444] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Revised: 05/28/2021] [Accepted: 06/01/2021] [Indexed: 12/05/2022] Open
Abstract
Subarachnoid hemorrhage (SAH) is associated with acute and delayed cerebral ischemia. We suggested spasms of pial arterioles as a possible mechanism; however, it remained unclear whether and how pial microvasospasms (MVSs) induce cerebral ischemia. Therefore, we used in vivo deep tissue imaging by two-photon microscopy to investigate MVSs together with the intraparenchymal microcirculation in a clinically relevant murine SAH model. Male C57BL/6 mice received a cranial window. Cerebral vessels and leukocytes were labelled with fluorescent dyes and imaged by in vivo two-photon microscopy before and three hours after SAH induced by filament perforation. After SAH, a large clot formed around the perforation site at the skull base, and blood distributed along the perivascular space of the middle cerebral artery up to the cerebral cortex. Comparing the cerebral microvasculature before and after SAH, we identified three different patterns of constrictions: pearl string, global, and bottleneck. At the same time, the volume of perfused intraparenchymal vessels and blood flow velocity in individual arterioles were significantly reduced by more than 60%. Plugging of capillaries by leukocytes was observed but infrequent. The current study demonstrates that perivascular blood is associated with spasms of pial arterioles and that these spasms result in a significant reduction in cortical perfusion after SAH. Thus, the pial microvasospasm seems to be an important mechanism by which blood in the subarachnoid space triggers cerebral ischemia after SAH. Identifying the mechanisms of pial vasospasm may therefore result in novel therapeutic options for SAH patients.
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Affiliation(s)
- Julian Schwarting
- Institute for Stroke and Dementia Research, Munich University Hospital, Graduate School of Systemic Neurosciences, Munich Cluster for Systems Neurology (SyNergy), Ludwig-Maximilians-University, 81377 Munich, Germany; (J.S.); (K.N.); (H.L.); (N.A.T.)
- Department of Neurosurgery, Munich University Hospital, 81377 Munich, Germany
| | - Kathrin Nehrkorn
- Institute for Stroke and Dementia Research, Munich University Hospital, Graduate School of Systemic Neurosciences, Munich Cluster for Systems Neurology (SyNergy), Ludwig-Maximilians-University, 81377 Munich, Germany; (J.S.); (K.N.); (H.L.); (N.A.T.)
| | - Hanhan Liu
- Institute for Stroke and Dementia Research, Munich University Hospital, Graduate School of Systemic Neurosciences, Munich Cluster for Systems Neurology (SyNergy), Ludwig-Maximilians-University, 81377 Munich, Germany; (J.S.); (K.N.); (H.L.); (N.A.T.)
| | - Nikolaus Plesnila
- Institute for Stroke and Dementia Research, Munich University Hospital, Graduate School of Systemic Neurosciences, Munich Cluster for Systems Neurology (SyNergy), Ludwig-Maximilians-University, 81377 Munich, Germany; (J.S.); (K.N.); (H.L.); (N.A.T.)
| | - Nicole Angela Terpolilli
- Institute for Stroke and Dementia Research, Munich University Hospital, Graduate School of Systemic Neurosciences, Munich Cluster for Systems Neurology (SyNergy), Ludwig-Maximilians-University, 81377 Munich, Germany; (J.S.); (K.N.); (H.L.); (N.A.T.)
- Department of Neurosurgery, Munich University Hospital, 81377 Munich, Germany
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7
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Rehnström M, Frederiksen SD, Ansar S, Edvinsson L. Transcriptome profiling revealed early vascular smooth muscle cell gene activation following focal ischemic stroke in female rats - comparisons with males. BMC Genomics 2020; 21:883. [PMID: 33297959 PMCID: PMC7726885 DOI: 10.1186/s12864-020-07295-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2020] [Accepted: 11/28/2020] [Indexed: 11/10/2022] Open
Abstract
Background Women account for 60% of all stroke deaths and are more often permanently disabled than men, despite their higher observed stroke incidence. Considering the clinical population affected by stroke, an obvious drawback is that many pre-clinical and clinical studies only investigate young males. To improve therapeutic translation from bench to bedside, we believe that it is advantageous to include both sexes in experimental models of stroke. The aims of this study were to identify early cerebral vascular responses to ischemic stroke in females, compare the differential gene expression patterns with those seen in males, and identify potential new therapeutic targets. Results Transient middle cerebral artery occlusion (tMCAO) was used to induce stroke in both female and male rats, the middle cerebral arteries (MCAs) were isolated 3 h post reperfusion and RNA was extracted. Affymetrix whole transcriptome expression profiling was performed on female (n = 12) MCAs to reveal differentially expressed genes. In total, 1076 genes had an increased expression and 879 genes a decreased expression in the occluded MCAs as compared with the control MCAs from female rats. An enrichment of genes related to apoptosis, regulation of transcription, protein autophosphorylation, inflammation, oxidative stress, and tissue repair and recovery were seen in the occluded MCA. The high expression genes chosen for qPCR verification (Adamts4, Olr1, JunB, Fosl1, Serpine1, S1pr3, Ccl2 and Socs3) were all shown to be upregulated in the same manner in both females and males after tMCAO (p < 0.05; n = 23). When comparing the differentially expressed genes in female MCAs (occluded and non-occluded) with our previous findings in males after tMCAO, a total of 297 genes overlapped (all groups had 32 genes in common). Conclusions The cascades of processes initiated in the vasculature following reperfusion are complex. Dynamic gene expression alterations were observed in the occluded MCAs, and to a less pronounced degree in the non-occluded MCAs. Dysregulation of inflammation and blood-brain barrier breakdown are possible pharmacological targets. The sample of genes (< 1% of the differentially expressed genes) validated for this microarray did not reveal any sex differences. However, sex differences might be observed for other gene targets. Supplementary Information The online version contains supplementary material available at 10.1186/s12864-020-07295-2.
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Affiliation(s)
- Mimmi Rehnström
- Department of Internal Medicine, Lund University Hospital, S22185, Lund, Sweden
| | | | - Saema Ansar
- Department of Clinical Sciences, Neurosurgery, Lund University, Lund, Sweden
| | - Lars Edvinsson
- Department of Internal Medicine, Lund University Hospital, S22185, Lund, Sweden.
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Khey KMW, Huard A, Mahmoud SH. Inflammatory Pathways Following Subarachnoid Hemorrhage. Cell Mol Neurobiol 2019; 40:675-693. [PMID: 31808009 DOI: 10.1007/s10571-019-00767-4] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2019] [Accepted: 11/23/2019] [Indexed: 02/07/2023]
Abstract
Aneurysmal subarachnoid hemorrhage (SAH) is an acute cerebrovascular emergency resulting from the rupture of a brain aneurysm. Despite only accounting for 5% of all strokes, SAH imposes a significant health burden on society due to its relatively young age at onset. Those who survive the initial bleed are often afflicted with severe disabilities thought to result from delayed cerebral ischemia (DCI). Consequently, elucidating the underlying mechanistic pathways implicated in DCI development following SAH remains a priority. Neuroinflammation has recently been implicated as a promising new theory for the development of SAH complications. However, despite this interest, clinical trials have failed to provide consistent evidence for the use of anti-inflammatory agents in SAH patients. This may be explained by the complexity of SAH as a plethora of inflammatory pathways have been shown to be activated in the disease. By determining how these pathways may overlap and interact, we hope to better understand the developmental processes of SAH complications and how to prevent them. The goal of this review is to provide insight into the available evidence regarding the molecular pathways involved in the development of inflammation following SAH and how SAH complications may arise as a result of these inflammatory pathways.
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Affiliation(s)
- Kevin Min Wei Khey
- Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, AB, Canada
| | - Alec Huard
- Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, AB, Canada
| | - Sherif Hanafy Mahmoud
- Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, AB, Canada.
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Christensen ST, Johansson SE, Radziwon-Balicka A, Warfvinge K, Haanes KA, Edvinsson L. MEK1/2 inhibitor U0126, but not nimodipine, reduces upregulation of cerebrovascular contractile receptors after subarachnoid haemorrhage in rats. PLoS One 2019; 14:e0215398. [PMID: 30978262 PMCID: PMC6461292 DOI: 10.1371/journal.pone.0215398] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2019] [Accepted: 04/02/2019] [Indexed: 12/19/2022] Open
Abstract
Vascular pathophysiological changes after haemorrhagic stroke, such as phenotypic modulation of the cerebral arteries and cerebral vasospasms, are associated with delayed cerebral ischemia (DCI) and poor outcome. The only currently approved drug treatment shown to reduce the risk of DCI and improve neurologic outcome after aneurysmal subarachnoid haemorrhage (SAH) is nimodipine, a dihydropyridine L-type voltage-gated Ca2+ channel blocker. MEK1/2 mediated transcriptional upregulation of contractile receptors, including endothelin-1 (ET-1) receptors, has previously been shown to be a factor in the pathology of SAH. The aim of the study was to compare intrathecal and subcutaneous treatment regimens of nimodipine and intrathecal treatment regimens of U0126, a MEK1/2 inhibitor, in a single injection experimental rat SAH model with post 48 h endpoints consisting of wire myography of cerebral arteries, flow cytometry of cerebral arterial tissue and behavioural evaluation. Following ET-1 concentration-response curves, U0126 exposed arteries had a significantly lower ET-1max than vehicle arteries. Arteries from both the intrathecal- and subcutaneous nimodipine treated animals had significantly higher ET-1max contractions than the U0126 arteries. Furthermore, Ca2+ concentration response curves (precontracted with ET-1 and in the presence of nimodipine) showed that nimodipine treatment could result in larger nimodipine insensitive contractions compared to U0126. Flow cytometry showed decreased protein expression of the ETB receptor in U0126 treated cerebral vascular smooth muscle cells compared to vehicle. Only U0126 treatment lowered ET-1max contractions and ETB receptor levels, as well as decreased the contractions involving nimodipine-insensitive Ca2+ channels, when compared to both intrathecal and subcutaneous nimodipine treatment. This indicate that targeting gene expression might be a better strategy than blocking specific receptors or ion channels in future treatments of SAH.
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Affiliation(s)
- Simon T. Christensen
- Department of Clinical Experimental Research, Copenhagen University Hospital, Rigshospitalet-Glostrup, Denmark
| | - Sara E. Johansson
- Department of Clinical Experimental Research, Copenhagen University Hospital, Rigshospitalet-Glostrup, Denmark
| | - Aneta Radziwon-Balicka
- Department of Clinical Experimental Research, Copenhagen University Hospital, Rigshospitalet-Glostrup, Denmark
| | - Karin Warfvinge
- Department of Clinical Experimental Research, Copenhagen University Hospital, Rigshospitalet-Glostrup, Denmark
- Department of Clinical Sciences, Division of Experimental Vascular Research, Lund University, Lund, Sweden
| | - Kristian A. Haanes
- Department of Clinical Experimental Research, Copenhagen University Hospital, Rigshospitalet-Glostrup, Denmark
- * E-mail:
| | - Lars Edvinsson
- Department of Clinical Experimental Research, Copenhagen University Hospital, Rigshospitalet-Glostrup, Denmark
- Department of Clinical Sciences, Division of Experimental Vascular Research, Lund University, Lund, Sweden
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10
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Lin QS, Wang WX, Lin YX, Lin ZY, Yu LH, Kang Y, Kang DZ. Annexin A7 induction of neuronal apoptosis via effect on glutamate release in a rat model of subarachnoid hemorrhage. J Neurosurg 2019; 132:777-787. [PMID: 30717037 DOI: 10.3171/2018.9.jns182003] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2018] [Accepted: 09/28/2018] [Indexed: 01/29/2023]
Abstract
OBJECTIVE Glutamate excitotoxicity and neuronal apoptosis are suggested to contribute to early brain injury after subarachnoid hemorrhage (SAH). Annexin A7 (ANXA7) has been shown to regulate glutamate release. However, the role of ANXA7 in early brain injury after SAH has not been illustrated. In this study, we aimed to investigate the effect of ANXA7 knockdown in reducing the severity of early brain injury after SAH, and determine the underlying mechanisms. METHODS Endovascular perforation was performed to induce SAH in male Sprague-Dawley rats. ANXA7-siRNA was administered via intraventricular injection 5 days before SAH induction. Neurological test, evaluation of SAH grade, assessment of blood-brain barrier (BBB) permeability, measurement of brain water content, Western blot, double immunofluorescence staining, TUNEL staining, and enzyme-linked immunosorbent assay (ELISA) were performed at 24 hours of SAH induction. RESULTS ANXA7 protein expression increased significantly after SAH induction and was seen mainly in neurons. High expression of ANXA7 was associated with poor neurological status. ANXA7 knockdown dramatically ameliorated early brain injury through alleviating BBB disruption and brain edema. Further investigation of the mechanism showed that inhibiting ANXA7 expression can rescue neuronal apoptosis. In addition, ANXA7 knockdown also significantly reduced glutamate release, which was consistent with a significant increase of Bcl-2 expression and decreases of Bax and cleaved caspase-3 expression. CONCLUSIONS ANXA7 can induce neuronal apoptosis by affecting glutamate release in rats with SAH. Downregulating the expression of ANXA7 can significantly attenuate early brain injury after SAH. Future therapy targeting ANXA7 may be a promising new choice.
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Huang L, Hou Y, Wang L, Xu X, Guan Q, Li X, Chen Y, Zhou W. p38 Inhibitor Protects Mitochondrial Dysfunction by Induction of DJ-1 Mitochondrial Translocation After Subarachnoid Hemorrhage. J Mol Neurosci 2018; 66:163-171. [PMID: 30242669 DOI: 10.1007/s12031-018-1131-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2018] [Accepted: 07/19/2018] [Indexed: 12/20/2022]
Abstract
p38 mitogen-activated protein kinase (MAPK) is a major player in mitochondrial dysfunction after subarachnoid hemorrhage (SAH). Moreover, DJ-1, which responds to oxidative stress and translocates to mitochondria, maintains mitochondrial homeostasis. Although a few studies have demonstrated that DJ-1 indirectly regulates p38 activation, the relationship between DJ-1 and p38 in mitochondrial dysfunction after SAH has not been delineated. Using an in vitro SAH model, alterations in p38, p-p38, DJ-1, and autophagic-related protein expression were detected. As expected, p38 inhibitor significantly blocked excessive expression of p38 and p-p38 after SAH, whereas total DJ-1 expression and mitochondrial DJ-1 were up-regulated. Further analysis showed that p38 inhibitor significantly blocked oxyhemoglobin (OxyHb) induced mitochondrial dysfunction, including mitochondrial membrane potential depolarization and reactive oxygen species (ROS) release. In addition, p38 inhibitor restored OxyHb-induced abnormal autophagic flux at the initiation and formation stage by regulating Atg5, beclin-1, the ratio of LC3-II/LC3-I, and p62 expression. This study suggested that overexpression of p38 induced the accumulation of mitochondrial dysfunction partly due to abnormal activation of autophagy, which largely relied on DJ-1 mitochondrial translocation.
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Affiliation(s)
- Liyong Huang
- Department of Neurosurgery, The First Affiliated Hospital of Xinxiang Medical University, Weihui, 453100, Henan, China
| | - Yaqing Hou
- Department of Neurosurgery, The First Affiliated Hospital of Xinxiang Medical University, Weihui, 453100, Henan, China
| | - Lei Wang
- Department of Neurosurgery, The First Affiliated Hospital of Xinxiang Medical University, Weihui, 453100, Henan, China
| | - Xiahui Xu
- Department of Neurosurgery, The First Affiliated Hospital of Xinxiang Medical University, Weihui, 453100, Henan, China
| | - Qingkai Guan
- Department of Neurosurgery, The First Affiliated Hospital of Xinxiang Medical University, Weihui, 453100, Henan, China
| | - Xiangsheng Li
- Department of Neurosurgery, The First Affiliated Hospital of Xinxiang Medical University, Weihui, 453100, Henan, China
| | - Ying Chen
- College of Life Science, Henan Normal University, Xinxiang, 453007, Henan, China
| | - Wenke Zhou
- Department of Neurosurgery, The First Affiliated Hospital of Xinxiang Medical University, Weihui, 453100, Henan, China.
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12
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Song S, Chen Y, Han F, Dong M, Xiang X, Sui J, Li Y, Yang H, Liu J. Aloperine activates the Nrf2-ARE pathway when ameliorating early brain injury in a subarachnoid hemorrhage model. Exp Ther Med 2018; 15:3847-3855. [PMID: 29563984 PMCID: PMC5858125 DOI: 10.3892/etm.2018.5896] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2017] [Accepted: 10/13/2017] [Indexed: 12/14/2022] Open
Abstract
Aloperine (ALO) exhibits neuroprotective effects against oxidative stress in vitro; however, its protective effect in early brain injury (EBI) following experimental subarachnoid hemorrhage (SAH) remains to be elucidated. The aim of the current study was to evaluate the antioxidant activity of ALO in EBI, and its association with nuclear factor erythroid-related factor 2 and the antioxidant responsive element (Nrf2-ARE) survival pathway. In the present study, an experimental SAH model was induced in rats following a prechiasmatic cistern injection. All rats were randomly divided into five groups: Sham, SAH, SAH+ vehicle, and an SAH+ ALO group (including low and high doses). ALO was administrated intraperitoneally at 2 and 24 h following induction of the SAH model. Brain samples were collected from each group at 48 h after SAH induction. Subsequently, western blotting, immunohistochemistry and cell apoptosis assays were performed, along with assessments for brain edema, neurological deficit, and the activity of oxidant/antioxidant factors. It was observed that the expression of Nrf2-ARE pathway-associated agents, including Nrf2, and heme oxygenase-1, were markedly increased in the high concentration ALO group compared with that of the SAH group. In addition, the level of oxidative damage was reduced. Furthermore, early brain damage, including brain edema, neurological deficit and cellular apoptosis were significantly ameliorated. In conclusion, the results of the present study indicate that ALO can ameliorate oxidative damage against EBI following SAH, most likely via the Nrf2-ARE survival pathway.
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Affiliation(s)
- Shibin Song
- Department of Neurosurgery, Affiliated Hospital of Guizhou Medical University, Guiyang, Guizhou 550004, P.R. China
| | - Yimin Chen
- Department of Neurosurgery, Affiliated Hospital of Guizhou Medical University, Guiyang, Guizhou 550004, P.R. China
| | - Feng Han
- Department of Neurosurgery, Affiliated Hospital of Guizhou Medical University, Guiyang, Guizhou 550004, P.R. China
| | - Minghao Dong
- Department of Neurosurgery, Affiliated Hospital of Guizhou Medical University, Guiyang, Guizhou 550004, P.R. China
| | - Xin Xiang
- Department of Neurosurgery, Affiliated Hospital of Guizhou Medical University, Guiyang, Guizhou 550004, P.R. China
| | - Jianmei Sui
- Department of Neurosurgery, Affiliated Hospital of Guizhou Medical University, Guiyang, Guizhou 550004, P.R. China
| | - Yuming Li
- Department of Neurosurgery, Affiliated Hospital of Guizhou Medical University, Guiyang, Guizhou 550004, P.R. China
| | - Hua Yang
- Department of Neurosurgery, Affiliated Hospital of Guizhou Medical University, Guiyang, Guizhou 550004, P.R. China
| | - Jian Liu
- Department of Neurosurgery, Affiliated Hospital of Guizhou Medical University, Guiyang, Guizhou 550004, P.R. China
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13
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Leclerc JL, Garcia JM, Diller MA, Carpenter AM, Kamat PK, Hoh BL, Doré S. A Comparison of Pathophysiology in Humans and Rodent Models of Subarachnoid Hemorrhage. Front Mol Neurosci 2018; 11:71. [PMID: 29623028 PMCID: PMC5875105 DOI: 10.3389/fnmol.2018.00071] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2017] [Accepted: 02/20/2018] [Indexed: 01/03/2023] Open
Abstract
Non-traumatic subarachnoid hemorrhage (SAH) affects an estimated 30,000 people each year in the United States, with an overall mortality of ~30%. Most cases of SAH result from a ruptured intracranial aneurysm, require long hospital stays, and result in significant disability and high fatality. Early brain injury (EBI) and delayed cerebral vasospasm (CV) have been implicated as leading causes of morbidity and mortality in these patients, necessitating intense focus on developing preclinical animal models that replicate clinical SAH complete with delayed CV. Despite the variety of animal models currently available, translation of findings from rodent models to clinical trials has proven especially difficult. While the explanation for this lack of translation is unclear, possibilities include the lack of standardized practices and poor replication of human pathophysiology, such as delayed cerebral vasospasm and ischemia, in rodent models of SAH. In this review, we summarize the different approaches to simulating SAH in rodents, in particular elucidating the key pathophysiology of the various methods and models. Ultimately, we suggest the development of standardized model of rodent SAH that better replicates human pathophysiology for moving forward with translational research.
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Affiliation(s)
- Jenna L Leclerc
- Department of Anesthesiology, University of Florida, Gainesville, FL, United States.,Department of Neuroscience, Center for Translational Research in Neurodegenerative Disease, McKnight Brain Institute, University of Florida, Gainesville, FL, United States
| | - Joshua M Garcia
- Department of Anesthesiology, University of Florida, Gainesville, FL, United States
| | - Matthew A Diller
- Department of Anesthesiology, University of Florida, Gainesville, FL, United States
| | - Anne-Marie Carpenter
- Department of Anesthesiology, University of Florida, Gainesville, FL, United States
| | - Pradip K Kamat
- Department of Anesthesiology, University of Florida, Gainesville, FL, United States
| | - Brian L Hoh
- Department of Neuroscience, Center for Translational Research in Neurodegenerative Disease, McKnight Brain Institute, University of Florida, Gainesville, FL, United States.,Department of Neurosurgery, University of Florida, Gainesville, FL, United States
| | - Sylvain Doré
- Department of Anesthesiology, University of Florida, Gainesville, FL, United States.,Department of Neuroscience, Center for Translational Research in Neurodegenerative Disease, McKnight Brain Institute, University of Florida, Gainesville, FL, United States.,Department of Neurology, Psychiatry, and Pharmaceutics, University of Florida, Gainesville, FL, United States
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Proteomic Expression Changes in Large Cerebral Arteries After Experimental Subarachnoid Hemorrhage in Rat Are Regulated by the MEK-ERK1/2 Pathway. J Mol Neurosci 2017; 62:380-394. [PMID: 28741142 PMCID: PMC5541124 DOI: 10.1007/s12031-017-0944-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2017] [Accepted: 06/28/2017] [Indexed: 12/13/2022]
Abstract
Subarachnoid hemorrhage (SAH) is a serious clinical condition where leakage of blood into the subarachnoid space causes an acute rise in intracranial pressure and reduces cerebral blood flow, which may lead to delayed cerebral ischemia and poor outcome. In experimental SAH, we have previously shown that the outcome can be significantly improved by early inhibition of the MAPK/ERK kinase/extracellular signal-regulated kinase (MEK/ERK1/2) pathway. The aim of this study was to apply mass spectrometry to investigate the overall late effects of experimental SAH on cerebrovascular protein expression. SAH was induced in rats that were treated with the MEK1/2 inhibitor U0126 or vehicle. Neurological outcome was assessed using a battery of behavioral tests. Specific protein expression of large cerebral arteries was analyzed quantitatively with high-throughput tandem mass spectrometry. SAH resulted in a marked reduction of neurological scores, which was counteracted by U0126 treatment. Mass spectrometry analysis demonstrated regulation of 184 proteins after SAH, regulations that were in part prevented by U0126 treatment. Network analysis identified several protein networks including a strong structural network centered around 14-3-3. Additionally, protein networks with functions in mRNA metabolism and protein folding were identified. Treatment with U0126 inhibited cerebral vessel wall pERK1/2 expression and significantly improved outcome of the rats. In conclusion, we show that SAH induces a broad array of specific changes in the overall protein networks in cerebral artery smooth muscle cells and suggest that this is essential for understanding the vascular pathophysiology after SAH.
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15
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Liu Q, Gonzales RJ. Targeting mitogen-activated protein kinase in acute ischaemic stroke. Acta Physiol (Oxf) 2017; 219:712-714. [PMID: 28035739 DOI: 10.1111/apha.12848] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Q. Liu
- Department of Neurology; Barrow Neurological Institute; Phoenix AZ USA
| | - R. J. Gonzales
- Department of Basic Medical Sciences; University of Arizona; Phoenix AZ USA
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16
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Mostajeran M, Edvinsson L, Warfvinge K, Singh R, Ansar S. Inhibition of mitogen-activated protein kinase 1/2 in the acute phase of stroke improves long-term neurological outcome and promotes recovery processes in rats. Acta Physiol (Oxf) 2017; 219:814-824. [PMID: 26595054 DOI: 10.1111/apha.12632] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2015] [Revised: 10/30/2015] [Accepted: 11/16/2015] [Indexed: 01/11/2023]
Abstract
AIM Extracellular signal-regulated kinase (ERK) 1/2 is activated during acute phase of stroke and contributes to stroke pathology. We have found that acute treatment with MEK1/2 inhibitors decreases infarct size and neurological deficits 2 days after experimental stroke. However, it is not known whether benefits of this inhibition persist long-term. Therefore, the aim of this study was to assess neurological function, infarct size and recovery processes 14 days after stroke in male rats to determine long-term outcome following acute treatment with the MEK1/2 inhibitor U0126. METHODS Transient middle cerebral artery occlusion was induced in male rats. U0126 or vehicle was given at 0 and 24 h of reperfusion. Neurological function was assessed by staircase, 6-point and 28-point neuroscore tests up to 14 days after induction of stroke. At day 14, infarct volumes were determined and recovery processes were evaluated by measuring protein expression of the tyrosine kinase receptor Tie-2 and nestin. Levels of p-ERK1/2 protein were determined. RESULTS Acute treatment with U0126 significantly improved long-term functional recovery, reduced infarct size, and enhanced Tie-2 and nestin protein expression at 14 days post-stroke. There was no residual blockade of p-ERK1/2 at this time point. CONCLUSION It is demonstrated that benefits of early treatment with U0126 persist beyond subacute phase of ischaemic stroke in male rats. Prevention of ERK1/2 activation in the acute phase results in improved long-term functional outcome and enhances later-stage recovery processes. These results expand our understanding of the benefits and promise of using MEK1/2 inhibitors in stroke recovery.
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Affiliation(s)
- M. Mostajeran
- Division of Experimental Vascular Research; Department of Clinical Sciences; Lund University; Lund Sweden
| | - L. Edvinsson
- Division of Experimental Vascular Research; Department of Clinical Sciences; Lund University; Lund Sweden
| | - K. Warfvinge
- Division of Experimental Vascular Research; Department of Clinical Sciences; Lund University; Lund Sweden
| | - R. Singh
- Division of Experimental Vascular Research; Department of Clinical Sciences; Lund University; Lund Sweden
| | - S. Ansar
- Division of Experimental Vascular Research; Department of Clinical Sciences; Lund University; Lund Sweden
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17
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Nonose Y, Gewehr PE, Almeida RF, da Silva JS, Bellaver B, Martins LAM, Zimmer ER, Greggio S, Venturin GT, Da Costa JC, Quincozes-Santos A, Pellerin L, de Souza DO, de Assis AM. Cortical Bilateral Adaptations in Rats Submitted to Focal Cerebral Ischemia: Emphasis on Glial Metabolism. Mol Neurobiol 2017; 55:2025-2041. [PMID: 28271402 DOI: 10.1007/s12035-017-0458-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2016] [Accepted: 02/13/2017] [Indexed: 11/30/2022]
Abstract
This study was performed to evaluate the bilateral effects of focal permanent ischemia (FPI) on glial metabolism in the cerebral cortex. Two and 9 days after FPI induction, we analyze [18F]FDG metabolism by micro-PET, astrocyte morphology and reactivity by immunohistochemistry, cytokines and trophic factors by ELISA, glutamate transporters by RT-PCR, monocarboxylate transporters (MCTs) by western blot, and substrate uptake and oxidation by ex vivo slices model. The FPI was induced surgically by thermocoagulation of the blood in the pial vessels of the motor and sensorimotor cortices in adult (90 days old) male Wistar rats. Neurochemical analyses were performed separately on both ipsilateral and contralateral cortical hemispheres. In both cortical hemispheres, we observed an increase in tumor necrosis factor alpha (TNF-α), interleukin-1β (IL-1β), and glutamate transporter 1 (GLT-1) mRNA levels; lactate oxidation; and glutamate uptake and a decrease in brain-derived neurotrophic factor (BDNF) after 2 days of FPI. Nine days after FPI, we observed an increase in TNF-α levels and a decrease in BDNF, GLT-1, and glutamate aspartate transporter (GLAST) mRNA levels in both hemispheres. Additionally, most of the unilateral alterations were found only in the ipsilateral hemisphere and persisted until 9 days post-FPI. They include diminished in vivo glucose uptake and GLAST expression, followed by increased glial fibrillary acidic protein (GFAP) gray values, astrocyte reactivity, and glutamate oxidation. Astrocytes presented signs of long-lasting reactivity, showing a radial morphology. In the intact hemisphere, there was a decrease in MCT2 levels, which did not persist. Our study shows the bilateralism of glial modifications following FPI, highlighting the role of energy metabolism adaptations on brain recovery post-ischemia.
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Affiliation(s)
- Yasmine Nonose
- Postgraduate Program in Biological Sciences: Biochemistry, ICBS, Universidade Federal do Rio Grande do Sul (UFRGS), Rua Ramiro Barcelos, 2600 - Anexo Santa Cecília, Porto Alegre, RS, 90035-003, Brazil
| | - Pedro E Gewehr
- Postgraduate Program in Biological Sciences: Biochemistry, ICBS, Universidade Federal do Rio Grande do Sul (UFRGS), Rua Ramiro Barcelos, 2600 - Anexo Santa Cecília, Porto Alegre, RS, 90035-003, Brazil
| | - Roberto F Almeida
- Postgraduate Program in Biological Sciences: Biochemistry, ICBS, Universidade Federal do Rio Grande do Sul (UFRGS), Rua Ramiro Barcelos, 2600 - Anexo Santa Cecília, Porto Alegre, RS, 90035-003, Brazil
| | - Jussemara S da Silva
- Postgraduate Program in Biological Sciences: Biochemistry, ICBS, Universidade Federal do Rio Grande do Sul (UFRGS), Rua Ramiro Barcelos, 2600 - Anexo Santa Cecília, Porto Alegre, RS, 90035-003, Brazil
| | - Bruna Bellaver
- Postgraduate Program in Biological Sciences: Biochemistry, ICBS, Universidade Federal do Rio Grande do Sul (UFRGS), Rua Ramiro Barcelos, 2600 - Anexo Santa Cecília, Porto Alegre, RS, 90035-003, Brazil
| | - Leo A M Martins
- Postgraduate Program in Biological Sciences: Biochemistry, ICBS, Universidade Federal do Rio Grande do Sul (UFRGS), Rua Ramiro Barcelos, 2600 - Anexo Santa Cecília, Porto Alegre, RS, 90035-003, Brazil
| | - Eduardo R Zimmer
- Postgraduate Program in Biological Sciences: Biochemistry, ICBS, Universidade Federal do Rio Grande do Sul (UFRGS), Rua Ramiro Barcelos, 2600 - Anexo Santa Cecília, Porto Alegre, RS, 90035-003, Brazil.,Brain Institute of Rio Grande do Sul, Pontifícia Universidade Católica do Rio Grande do Sul (PUCRS), Porto Alegre, RS, 90619-900, Brazil
| | - Samuel Greggio
- Brain Institute of Rio Grande do Sul, Pontifícia Universidade Católica do Rio Grande do Sul (PUCRS), Porto Alegre, RS, 90619-900, Brazil
| | - Gianina T Venturin
- Brain Institute of Rio Grande do Sul, Pontifícia Universidade Católica do Rio Grande do Sul (PUCRS), Porto Alegre, RS, 90619-900, Brazil
| | - Jaderson C Da Costa
- Brain Institute of Rio Grande do Sul, Pontifícia Universidade Católica do Rio Grande do Sul (PUCRS), Porto Alegre, RS, 90619-900, Brazil
| | - André Quincozes-Santos
- Postgraduate Program in Biological Sciences: Biochemistry, ICBS, Universidade Federal do Rio Grande do Sul (UFRGS), Rua Ramiro Barcelos, 2600 - Anexo Santa Cecília, Porto Alegre, RS, 90035-003, Brazil.,Department of Biochemistry, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, 90035-003, Brazil
| | - Luc Pellerin
- Department of Physiology, University of Lausanne, 1005, Lausanne, Switzerland
| | - Diogo O de Souza
- Postgraduate Program in Biological Sciences: Biochemistry, ICBS, Universidade Federal do Rio Grande do Sul (UFRGS), Rua Ramiro Barcelos, 2600 - Anexo Santa Cecília, Porto Alegre, RS, 90035-003, Brazil.,Department of Biochemistry, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, 90035-003, Brazil
| | - Adriano M de Assis
- Postgraduate Program in Biological Sciences: Biochemistry, ICBS, Universidade Federal do Rio Grande do Sul (UFRGS), Rua Ramiro Barcelos, 2600 - Anexo Santa Cecília, Porto Alegre, RS, 90035-003, Brazil.
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Hasegawa Y, Suzuki H, Uekawa K, Kawano T, Kim-Mitsuyama S. Characteristics of Cerebrovascular Injury in the Hyperacute Phase After Induced Severe Subarachnoid Hemorrhage. Transl Stroke Res 2015; 6:458-66. [DOI: 10.1007/s12975-015-0423-9] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2015] [Revised: 08/30/2015] [Accepted: 09/01/2015] [Indexed: 10/23/2022]
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Carbone F, Teixeira PC, Braunersreuther V, Mach F, Vuilleumier N, Montecucco F. Pathophysiology and Treatments of Oxidative Injury in Ischemic Stroke: Focus on the Phagocytic NADPH Oxidase 2. Antioxid Redox Signal 2015; 23:460-89. [PMID: 24635113 PMCID: PMC4545676 DOI: 10.1089/ars.2013.5778] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
SIGNIFICANCE Phagocytes play a key role in promoting the oxidative stress after ischemic stroke occurrence. The phagocytic NADPH oxidase (NOX) 2 is a membrane-bound enzyme complex involved in the antimicrobial respiratory burst and free radical production in these cells. RECENT ADVANCES Different oxidants have been shown to induce opposite effects on neuronal homeostasis after a stroke. However, several experimental models support the detrimental effects of NOX activity (especially the phagocytic isoform) on brain recovery after stroke. Therapeutic strategies selectively targeting the neurotoxic ROS and increasing neuroprotective oxidants have recently produced promising results. CRITICAL ISSUES NOX2 might promote carotid plaque rupture and stroke occurrence. In addition, NOX2-derived reactive oxygen species (ROS) released by resident and recruited phagocytes enhance cerebral ischemic injury, activating the inflammatory apoptotic pathways. The aim of this review is to update evidence on phagocyte-related oxidative stress, focusing on the role of NOX2 as a potential therapeutic target to reduce ROS-related cerebral injury after stroke. FUTURE DIRECTIONS Radical scavenger compounds (such as Ebselen and Edaravone) are under clinical investigation as a therapeutic approach against stroke. On the other hand, NOX inhibition might represent a promising strategy to prevent the stroke-related injury. Although selective NOX inhibitors are not yet available, nonselective compounds (such as apocynin and fasudil) provided encouraging results in preclinical studies. Whereas additional studies are needed to better evaluate this therapeutic potential in human beings, the development of specific NOX inhibitors (such as monoclonal antibodies, small-molecule inhibitors, or aptamers) might further improve brain recovery after stroke.
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Affiliation(s)
- Federico Carbone
- 1 Division of Cardiology, Foundation for Medical Researches, Department of Medical Specialties, University of Geneva , Geneva, Switzerland .,2 Department of Internal Medicine, University of Genoa School of Medicine , IRCCS Azienda Ospedaliera Universitaria San Martino-IST Istituto Nazionale per la Ricerca sul Cancro, Genoa, Italy
| | - Priscila Camillo Teixeira
- 3 Division of Laboratory Medicine, Department of Genetics and Laboratory Medicine, Geneva University Hospitals , Geneva, Switzerland
| | - Vincent Braunersreuther
- 1 Division of Cardiology, Foundation for Medical Researches, Department of Medical Specialties, University of Geneva , Geneva, Switzerland
| | - François Mach
- 1 Division of Cardiology, Foundation for Medical Researches, Department of Medical Specialties, University of Geneva , Geneva, Switzerland
| | - Nicolas Vuilleumier
- 3 Division of Laboratory Medicine, Department of Genetics and Laboratory Medicine, Geneva University Hospitals , Geneva, Switzerland
| | - Fabrizio Montecucco
- 1 Division of Cardiology, Foundation for Medical Researches, Department of Medical Specialties, University of Geneva , Geneva, Switzerland .,2 Department of Internal Medicine, University of Genoa School of Medicine , IRCCS Azienda Ospedaliera Universitaria San Martino-IST Istituto Nazionale per la Ricerca sul Cancro, Genoa, Italy .,3 Division of Laboratory Medicine, Department of Genetics and Laboratory Medicine, Geneva University Hospitals , Geneva, Switzerland
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20
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Waldsee R, Eftekhari S, Ahnstedt H, Johnson LE, Edvinsson L. CaMKII and MEK1/2 inhibition time-dependently modify inflammatory signaling in rat cerebral arteries during organ culture. J Neuroinflammation 2014; 11:90. [PMID: 24886705 PMCID: PMC4039324 DOI: 10.1186/1742-2094-11-90] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2013] [Accepted: 05/01/2014] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND Cerebral ischemia induces transcriptional upregulation of inflammatory genes in the brain parenchyma and in cerebral arteries, thereby contributing to the infarct development. The present study was designed to evaluate the involvement of calcium-calmodulin-dependent protein kinase (CaMKII) II and extracellular signal-regulated kinase1/2 (ERK1/2) on inflammatory mediators in rat cerebral arteries using organ culture as a method for inducing ischemic-like vascular wall changes. METHODS Rat basilar arteries were cultured in serum-free medium for 0, 3, 6 or 24 hours in the presence or absence of the CaMKII inhibitor KN93 or the MEK1/2 inhibitor U0126. Protein expression of activated CaMKII, ERK1/2, and inflammatory-associated protein kinases and mediators were examined with western blot and immunohistochemistry. Caspase-3 mRNA levels in basilar arteries were studied with real-time PCR. RESULTS Western blot evaluation showed that organ culture induced a significant increase in phosphorylated ERK1/2 at 3, 6 and 24 hours, while CaMKII was found to be already activated in fresh non-incubated arteries and to decrease with incubation time. The addition of U0126 or KN93 decreased levels of phosphorylated c-Jun N-terminal kinase and p-p38, as evaluated by immunohistochemistry. KN93 affected the increase in caspase-3 mRNA expression only when given at the start of incubation, while U0126 had an inhibitory effect when given up to six hours later. Tumor necrosis factor receptor 1 was elevated after organ culture. This inflammatory marker was reduced by both of the two different protein kinase inhibitors. CONCLUSIONS The novel findings of the present study are that the cross-talk between the two protein kinases and the inhibition of CaMKII or MEK1/2 in a time-dependent manner attenuates inflammatory-associated protein kinases and mediators, suggesting that they play a role in cerebrovascular inflammation.
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Affiliation(s)
| | | | | | | | - Lars Edvinsson
- Department of Clinical Sciences, Division of Experimental Vascular Research, Lund University, Sölvegatan 17, SE-221 84 Lund, Sweden.
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21
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Subarachnoid Hemorrhage: a Review of Experimental Studies on the Microcirculation and the Neurovascular Unit. Transl Stroke Res 2014; 5:174-89. [DOI: 10.1007/s12975-014-0323-4] [Citation(s) in RCA: 93] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2013] [Revised: 12/20/2013] [Accepted: 01/03/2014] [Indexed: 11/29/2022]
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22
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Zhou XM, Zhou ML, Zhang XS, Zhuang Z, Li T, Shi JX, Zhang X. Resveratrol prevents neuronal apoptosis in an early brain injury model. J Surg Res 2014; 189:159-65. [PMID: 24602480 DOI: 10.1016/j.jss.2014.01.062] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2013] [Revised: 01/29/2014] [Accepted: 01/31/2014] [Indexed: 10/25/2022]
Abstract
BACKGROUND Resveratrol has been shown to attenuate cerebral vasospasm after subarachnoid hemorrhage (SAH); however, no study has explored its neuroprotective effect in early brain injury (EBI) after experimental SAH. The aim of this study was to evaluate the antiapoptotic function of resveratrol in EBI and its relationship with the PI3K/Akt survival pathway. METHODS Experimental SAH was induced in adult male rats by prechiasmatic cistern injection. Control and SAH rats were divided into six groups and treated with low (20 mg/kg) or high (60 mg/kg) concentrations of resveratrol with or without LY294002 cotreatment. Brain samples of the rats were analyzed by immunohistochemistry, immunofluorescence staining, Western blotting, and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) apoptosis assays. RESULTS High-concentration but not low-concentration resveratrol treatment in SAH rats led to a significant increase in phosphorylated Akt (p-Akt) protein levels compared with SAH rats without treatment. In addition, p-Akt-positive cells mainly colocalized with NeuN-positive cells. Neuronal apoptosis in SAH rat brain was attenuated by high-concentration resveratrol treatment. The antiapoptotic effect of resveratrol in SAH rats could be partially abrogated by the PI3K/Akt signaling inhibitor LY294002. CONCLUSIONS Our results show that resveratrol has an antiapoptotic effect in EBI and that resveratrol might act through the PI3K/Akt signaling pathway.
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Affiliation(s)
- Xiao-Ming Zhou
- Department of Neurosurgery, Jinling Hospital, School of Medicine, Second Military Medical University, Shanghai, China
| | - Meng-Liang Zhou
- Department of Neurosurgery, Jinling Hospital, School of Medicine, Nanjing University, Nanjing, Jiangsu Province, China.
| | - Xiang-Sheng Zhang
- Department of Neurosurgery, Jinling Hospital, School of Medicine, Second Military Medical University, Shanghai, China
| | - Zong Zhuang
- Department of Neurosurgery, Jinling Hospital, School of Medicine, Nanjing University, Nanjing, Jiangsu Province, China
| | - Tao Li
- Department of Neurosurgery, Jinling Hospital, School of Medicine, Nanjing University, Nanjing, Jiangsu Province, China
| | - Ji-Xin Shi
- Department of Neurosurgery, Jinling Hospital, School of Medicine, Nanjing University, Nanjing, Jiangsu Province, China
| | - Xin Zhang
- Department of Neurosurgery, Jinling Hospital, School of Medicine, Second Military Medical University, Shanghai, China; Department of Neurosurgery, Jinling Hospital, School of Medicine, Nanjing University, Nanjing, Jiangsu Province, China.
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Edvinsson L, Larsen SS, Maddahi A, Nielsen J. Plasticity of cerebrovascular smooth muscle cells after subarachnoid hemorrhage. Transl Stroke Res 2014; 5:365-76. [PMID: 24449486 DOI: 10.1007/s12975-014-0331-4] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2013] [Revised: 12/19/2013] [Accepted: 01/06/2014] [Indexed: 12/27/2022]
Abstract
Subarachnoid hemorrhage (SAH) is most often followed by a delayed phase of cerebral ischemia which is associated with high morbidity and mortality rates. The causes underlying this delayed phase are still unsettled, but are believed to include cerebral vasospasm, cortical spreading depression, inflammatory reactions, and microthrombosis. Additionally, a large body of evidence indicates that vascular plasticity plays an important role in SAH pathophysiology, and this review aims to summarize our current knowledge on the phenotypic changes of vascular smooth muscle cells of the cerebral vasculature following SAH. In light of the emerging view that the whole cerebral vasculature and the cells of the brain parenchyma should be viewed as one integrated neurovascular network, phenotypical changes are discussed both for the cerebral arteries and the microvasculature. Furthermore, the intracellular signaling involved in the vascular plasticity is discussed with a focus on the Raf-MEK1/2-ERK1/2 pathway which seems to play a crucial role in SAH pathology.
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Affiliation(s)
- Lars Edvinsson
- Department of Clinical Experimental Research, Glostrup Research Institute, Glostrup University Hospital, Glostrup, Denmark,
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Povlsen GK, Johansson SE, Larsen CC, Samraj AK, Edvinsson L. Early events triggering delayed vasoconstrictor receptor upregulation and cerebral ischemia after subarachnoid hemorrhage. BMC Neurosci 2013; 14:34. [PMID: 23496889 PMCID: PMC3618233 DOI: 10.1186/1471-2202-14-34] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2012] [Accepted: 03/07/2013] [Indexed: 11/17/2022] Open
Abstract
BACKGROUND Upregulation of vasoconstrictor receptors in cerebral arteries, including endothelin B (ETB) and 5-hydroxytryptamine 1B (5-HT(1B)) receptors, has been suggested to contribute to delayed cerebral ischemia, a feared complication after subarachnoid hemorrhage (SAH). This receptor upregulation has been shown to be mediated by intracellular signalling via the mitogen activated protein kinase kinase (MEK1/2)--extracellular regulated kinase 1/2 (ERK1/2) pathway. However, it is not known what event(s) that trigger MEK-ERK1/2 activation and vasoconstrictor receptor upregulation after SAH.We hypothesise that the drop in cerebral blood flow (CBF) and wall tension experienced by cerebral arteries in acute SAH is a key triggering event. We here investigate the importance of the duration of this acute CBF drop in a rat SAH model in which a fixed amount of blood is injected into the prechiasmatic cistern either at a high rate resulting in a short acute CBF drop or at a slower rate resulting in a prolonged acute CBF drop. RESULTS We demonstrate that the duration of the acute CBF drop is determining for a) degree of early ERK1/2 activation in cerebral arteries, b) delayed upregulation of vasoconstrictor receptors in cerebral arteries and c) delayed CBF reduction, neurological deficits and mortality. Moreover, treatment with an inhibitor of MEK-ERK1/2 signalling during an early time window from 6 to 24 h after SAH was sufficient to completely prevent delayed vasoconstrictor receptor upregulation and improve neurological outcome several days after the SAH. CONCLUSIONS Our findings suggest a series of events where 1) the acute CBF drop triggers early MEK-ERK1/2 activation, which 2) triggers the transcriptional upregulation of vasoconstrictor receptors in cerebral arteries during the following days, where 3) the resulting enhanced cerebrovascular contractility contribute to delayed cerebral ischemia.
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Affiliation(s)
- Gro Klitgaard Povlsen
- Department of Clinical Experimental Research, Glostrup Research Institute, Glostrup University Hospital, Nordre Ringvej 69, Glostrup, DK 2600, Denmark
| | - Sara Ellinor Johansson
- Department of Clinical Experimental Research, Glostrup Research Institute, Glostrup University Hospital, Nordre Ringvej 69, Glostrup, DK 2600, Denmark
| | | | - Ajoy Kumar Samraj
- Department of Clinical Experimental Research, Glostrup Research Institute, Glostrup University Hospital, Nordre Ringvej 69, Glostrup, DK 2600, Denmark
| | - Lars Edvinsson
- Department of Clinical Experimental Research, Glostrup Research Institute, Glostrup University Hospital, Nordre Ringvej 69, Glostrup, DK 2600, Denmark
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Ansar S, Eftekhari S, Waldsee R, Nilsson E, Nilsson O, Säveland H, Edvinsson L. MAPK signaling pathway regulates cerebrovascular receptor expression in human cerebral arteries. BMC Neurosci 2013; 14:12. [PMID: 23343134 PMCID: PMC3663811 DOI: 10.1186/1471-2202-14-12] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2012] [Accepted: 12/26/2012] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Cerebral ischemia results in enhanced expression of contractile cerebrovascular receptors, such as endothelin type B (ET(B)), 5-hydroxytryptamine type 1B (5-HT(1B)), angiotensin II type 1 (AT(1)) and thromboxane (TP) receptors in the cerebral arteries within the ischemic area. The receptor upregulation occurs via activation of the mitogen-activated protein kinases (MAPK) pathway. Previous studies have shown that inhibitors of the MAPK pathway diminished the ischemic area and contractile cerebrovascular receptors after experimental cerebral ischemia. The aim of this study was to examine if the upregulation of contractile cerebrovascular receptors after 48 h of organ culture of human cerebral arteries involves MAPK pathways and if it can be prevented by a MEK1/2 inhibitor. Human cerebral arteries were obtained from patients undergoing intracranial tumor surgery. The vessels were divided into ring segments and incubated for 48 h in the presence or absence of the specific MEK1/2 inhibitor U0126. The vessels were then examined by using in vitro pharmacological methods and protein immunohistochemistry. RESULTS After organ culture of the cerebral arteries the contractile responses to endothelin (ET)-1, angiotensin (Ang) II and thromboxane (TP) were enhanced in comparison with fresh human arteries. However, 5-carboxamidotryptamine (5-CT) induced decreased contractile responses after organ culture as compared to fresh arteries. Incubation with U0126 diminished the maximum contraction elicited by application of ET-1, Ang II and U46619 in human cerebral arteries. In addition, the MEK1/2 inhibitor decreased the contractile response to 5-CT. Immunohistochemistry revealed that organ culture resulted in increased expression of endothelin ET(A), endothelin ET(B) angiotensin AT(2), 5-hydroxytryptamine 5-HT(1B) and thromboxane A2 receptors, and elevated levels of activated pERK1/2, all localized to the smooth muscle cells of the cerebral arteries. Co-incubation with U0126 normalized these proteins. CONCLUSION The study demonstrated that there is a clear association between human cerebrovascular receptor upregulation via transcription involving activation of the MAPK pathway after organ culture. Inhibition of the MAPK pathways attenuated the vasoconstriction mediated by ET, AT and TP receptors in human cerebral arteries and the enhanced expression of their receptors. The results indicate that MAPK inhibition might be a novel target for treatment of cerebrovascular disorders.
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Affiliation(s)
- Saema Ansar
- Department of Clinical Sciences, Division of Experimental Vascular Research, Lund University, Lund, Sweden.
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Fujimoto M, Suzuki H, Shiba M, Shimojo N, Imanaka-Yoshida K, Yoshida T, Kanamaru K, Matsushima S, Taki W. Tenascin-C induces prolonged constriction of cerebral arteries in rats. Neurobiol Dis 2013; 55:104-9. [PMID: 23333289 DOI: 10.1016/j.nbd.2013.01.007] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2012] [Revised: 12/10/2012] [Accepted: 01/10/2013] [Indexed: 12/13/2022] Open
Abstract
Tenascin-C (TNC), a matricellular protein, is induced in association with cerebral vasospasm after subarachnoid hemorrhage. The aim of this study was to assess the vasoconstrictive effects of TNC and its mechanisms of action on cerebral arteries in vivo. Two dosages (1 and 10μg) of TNC were administered intracisternally to healthy rats, and the effects were evaluated by neurobehavioral tests and India-ink angiography at 24, 48, and 72h after the administration. Western blotting and immunohistochemistry were performed to explore the underlying mechanisms on constricted cerebral arteries after 24h. The effects of toll-like receptor 4 (TLR4) antagonists (LPS-RS), c-Jun N-terminal kinase (JNK), and p38 inhibitors (SP600125 and SB203580) on TNC-induced vasoconstriction were evaluated at 24h. Higher dosages of TNC induced more severe cerebral arterial constriction, which continued for more than 72h. TNC administration also upregulated TLR4, and activated JNK and p38 in the smooth muscle cell layer of the constricted cerebral artery. LPS-RS blocked TNC-induced TLR4 upregulation, JNK and p38 activation, and vasoconstrictive effects. SP600125 and SB203580 abolished TNC-induced TLR4 upregulation and vasoconstrictive effects. TNC may cause prolonged cerebral arterial constriction via TLR4 and activation of JNK and p38, which may upregulate TLR4. These findings suggest that TNC causes cerebral vasospasm and provides a novel therapeutic approach against it.
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Affiliation(s)
- Masashi Fujimoto
- Department of Neurosurgery, Mie University Graduate School of Medicine, 2-174 Edobashi, Tsu, Mie, Japan
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Cao L, Xu CB, Zhang Y, Cao YX, Edvinsson L. Secondhand cigarette smoke exposure causes upregulation of cerebrovascular 5-HT(1) (B) receptors via the Raf/ERK/MAPK pathway in rats. Acta Physiol (Oxf) 2013; 207:183-93. [PMID: 22883081 DOI: 10.1111/j.1748-1716.2012.02478.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2012] [Revised: 05/03/2012] [Accepted: 08/06/2012] [Indexed: 11/28/2022]
Abstract
AIM Cigarette smoke exposure increases the risk of stroke. Upregulation of 5-hydroxytryptamine 1B (5-HT(1) (B) ) receptors is associated with the pathogenesis of cerebral ischaemia. This study examined the hypothesis that the expression of 5-HT(1) (B) receptors is altered in brain vessels after secondhand smoke (SHS) exposure. METHODS Rats were exposed to SHS in vivo for 200 min daily for 8 weeks. The contractile responses of isolated cerebral arteries were studies by a sensitive myograph. The mRNA and protein expression for 5-HT(1) (B) receptors were examined by real-time PCR, Western blot and immunofluorescence respectively. In addition, the phosphorylation of Raf/extracellular signal-regulated kinase (ERK)/mitogen-activated protein kinases (MAPK) pathway was evaluated. RESULTS The results showed that SHS exposure shifted the 5-HT(1) (B) receptor-mediated concentration-contraction curve towards the left with a markedly increased maximal contraction. Furthermore, there were significant elevations in mRNA level and protein expression of 5-HT(1) (B) receptors in SHS-exposed rats. Immunostaining revealed that the 5-HT(1) (B) receptors were localized to the smooth muscle cells of cerebral arteries. SHS was also found to induce the phosphorylation of Raf-1 and ERK1/2 proteins. The administration of a Raf-1 inhibitor GW5074 attenuated the 5-HT(1) (B) receptor upregulation. CONCLUSION Secondhand smoke exposure upregulates cerebrovascular 5-HT(1) (B) receptors in rats. The receptor upregulation is associated with Raf/ERK/MAPK activation.
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Affiliation(s)
- L. Cao
- Division of Experimental Vascular Research; Department of Clinical Sciences; Lund University; Lund; Sweden
| | - C. B. Xu
- Division of Experimental Vascular Research; Department of Clinical Sciences; Lund University; Lund; Sweden
| | - Y. Zhang
- Division of Experimental Vascular Research; Department of Clinical Sciences; Lund University; Lund; Sweden
| | - Y. X. Cao
- Department of Pharmacology; Xi'an Jiaotong University College of Medicine; Xi'an; Shaanxi; China
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Maddahi A, Povlsen GK, Edvinsson L. Regulation of enhanced cerebrovascular expression of proinflammatory mediators in experimental subarachnoid hemorrhage via the mitogen-activated protein kinase kinase/extracellular signal-regulated kinase pathway. J Neuroinflammation 2012; 9:274. [PMID: 23259581 PMCID: PMC3573995 DOI: 10.1186/1742-2094-9-274] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2012] [Accepted: 11/29/2012] [Indexed: 12/25/2022] Open
Abstract
BACKGROUND Subarachnoid hemorrhage (SAH) is associated with high morbidity and mortality. It is suggested that the associated inflammation is mediated through activation of the mitogen-activated protein kinase (MAPK) pathway which plays a crucial role in the pathogenesis of delayed cerebral ischemia after SAH. The aim of this study was first to investigate the timecourse of altered expression of proinflammatory cytokines and matrix metalloproteinase in the cerebral arteries walls following SAH. Secondly, we investigated whether administration of a specific mitogen-activated protein kinase kinase (MEK)1/2 inhibitor, U0126, given at 6 h after SAH prevents activation of the MEK/extracellular signal-regulated kinase 1/2 pathway and the upregulation of cerebrovascular inflammatory mediators and improves neurological function. METHODS SAH was induced in rats by injection of 250 μl of autologous blood into basal cisterns. U0126 was given intracisternally using two treatment regimens: (A) treatments at 6, 12, 24 and 36 h after SAH and experiments terminated at 48 h after SAH, or (B) treatments at 6, 12, and 24 h after SAH and terminated at 72 h after SAH. Cerebral arteries were harvested and interleukin (IL)-6, IL-1β, tumor necrosis factor α (TNF)α, matrix metalloproteinase (MMP)-9 and phosphorylated ERK1/2 (pERK1/2) levels investigated by immunohistochemistry. Early activation of pERK1/2 was measured by western blot. Functional neurological outcome after SAH was also analyzed. RESULTS Expression levels of IL-1β, IL-6, MMP-9 and pERK1/2 proteins were elevated over time with an early increase at around 6 h and a late peak at 48 to 72 h post-SAH in cerebral arteries. Enhanced expression of TNFα in cerebral arteries started at 24 h and increased until 96 h. In addition, SAH induced sensorimotor and spontaneous behavior deficits in the animals. Treatment with U0126 starting at 6 h after SAH prevented activation of MEK-ERK1/2 signaling. Further, U0126 significantly decreased the upregulation of inflammation proteins at 48 and 72 h following SAH and improved neurological function. We found no differences between treatment regimens A and B. CONCLUSIONS These results show that SAH induces early activation of the MEK-ERK1/2 pathway in cerebral artery walls, which is associated with upregulation of proinflammatory cytokines and MMP-9. Inhibition of the MEK-ERK1/2 pathway by U0126 starting at 6 h post-SAH prevented upregulation of cytokines and MMP-9 in cerebral vessels, and improved neurological outcome.
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Affiliation(s)
- Aida Maddahi
- Department of Clinical Sciences, Division of Experimental Vascular Research, Lund University, Lund, Sweden.
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29
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Sehba FA, Friedrich V. Cerebral microvasculature is an early target of subarachnoid hemorrhage. ACTA NEUROCHIRURGICA. SUPPLEMENT 2012; 115:199-205. [PMID: 22890669 DOI: 10.1007/978-3-7091-1192-5_37] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Most subarachnoid hemorrhage (SAH) patients exhibit clinical signs of cerebral ischemia at admission but no angiographic vasospasm. Consequently, the source of early cerebral ischemia is not understood. Parenchymal microvessels may contribute to early cerebral ischemia, but the low resolution of current imaging has prevented their analysis in SAH patients. Animal studies demonstrated that early after SAH structure and function of parenchymal vessels are compromised to the level that may very well contribute to early ischemia. We review these studies.
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Affiliation(s)
- Fatima A Sehba
- Department of Neurosurgery and Neurosciences, Mount Sinai School of Medicine, New York, NY 10029, USA.
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Kamp MA, Dibué M, Schneider T, Steiger HJ, Hänggi D. Calcium and potassium channels in experimental subarachnoid hemorrhage and transient global ischemia. Stroke Res Treat 2012; 2012:382146. [PMID: 23251831 PMCID: PMC3518967 DOI: 10.1155/2012/382146] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2012] [Accepted: 10/27/2012] [Indexed: 11/23/2022] Open
Abstract
Healthy cerebrovascular myocytes express members of several different ion channel families which regulate resting membrane potential, vascular diameter, and vascular tone and are involved in cerebral autoregulation. In animal models, in response to subarachnoid blood, a dynamic transition of ion channel expression and function is initiated, with acute and long-term effects differing from each other. Initial hypoperfusion after exposure of cerebral vessels to oxyhemoglobin correlates with a suppression of voltage-gated potassium channel activity, whereas delayed cerebral vasospasm involves changes in other potassium channel and voltage-gated calcium channels expression and function. Furthermore, expression patterns and function of ion channels appear to differ between main and small peripheral vessels, which may be key in understanding mechanisms behind subarachnoid hemorrhage-induced vasospasm. Here, changes in calcium and potassium channel expression and function in animal models of subarachnoid hemorrhage and transient global ischemia are systematically reviewed and their clinical significance discussed.
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Affiliation(s)
- Marcel A. Kamp
- Department for Neurosurgery, Medical Faculty, Heinrich Heine University, Moorenstraße 5, 40225 Düsseldorf, Germany
- Institute for Neurophysiology, University of Cologne, Robert-Koch-Straße 39, 50931 Cologne, Germany
| | - Maxine Dibué
- Department for Neurosurgery, Medical Faculty, Heinrich Heine University, Moorenstraße 5, 40225 Düsseldorf, Germany
- Institute for Neurophysiology, University of Cologne, Robert-Koch-Straße 39, 50931 Cologne, Germany
- Center of Molecular Medicine, Cologne, Germany
| | - Toni Schneider
- Institute for Neurophysiology, University of Cologne, Robert-Koch-Straße 39, 50931 Cologne, Germany
- Center of Molecular Medicine, Cologne, Germany
| | - Hans-Jakob Steiger
- Department for Neurosurgery, Medical Faculty, Heinrich Heine University, Moorenstraße 5, 40225 Düsseldorf, Germany
| | - Daniel Hänggi
- Department for Neurosurgery, Medical Faculty, Heinrich Heine University, Moorenstraße 5, 40225 Düsseldorf, Germany
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Sun L, Zhang W, Wang X, Song J, Li M. Inhibition of protein kinase C signal reduces ET receptor expression and basilar vasospasm after subarachnoid hemorrhage in rats. J Integr Neurosci 2012; 11:439-51. [DOI: 10.1142/s0219635212500288] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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Ahnstedt H, Stenman E, Cao L, Henriksson M, Edvinsson L. Cytokines and growth factors modify the upregulation of contractile endothelin ET(A) and ET(B) receptors in rat cerebral arteries after organ culture. Acta Physiol (Oxf) 2012; 205:266-78. [PMID: 22145714 DOI: 10.1111/j.1748-1716.2011.02392.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2011] [Revised: 09/20/2011] [Accepted: 11/30/2011] [Indexed: 11/30/2022]
Abstract
AIM Experimental cerebral ischaemia and organ culture of cerebral arteries induce an increased endothelin ET(B) receptor-mediated contraction. The aim of this study was to examine whether cytokines and growth factors, known to be activated in ischaemia, can influence the expression and function of endothelin receptors after organ culture. METHODS Rat middle cerebral arteries were cultured for 24 h at 37 °C in humidified 5% CO(2) and air in culture medium alone, or with tumour necrosis factor-α (TNF-α), interleukin-1β (IL-1β), platelet-derived growth factor (PDGF), epidermal growth factor (EGF) or basic fibroblast growth factor (bFGF). Concentration-response curves were obtained for sarafotoxin 6c (ET(B) receptor agonist) and endothelin-1 (here ET(A) receptor agonist, because of ET(B) receptor desensitization). The receptor mRNA expression was examined by real-time PCR and the protein expression by immunohistochemistry and Western blot. RESULTS Tumour necrosis factor-α (100 ng mL(-1) ) and EGF (20 ng mL(-1) ) potentiated the ET(B) receptor-mediated contraction (increase in pEC(50) without change in E(max) ). bFGF (10 ng mL(-1) ) and IL-1β (10 ng mL(-1) ) induced an enhanced ET(A) receptor-mediated contraction. bFGF (10 ng mL(-1) ) significantly increased the ET(B) mRNA level, and EGF (20 ng mL(-1) ) increased the ET(A) receptor protein. Increased ET(B) receptor mRNA and protein level also were observed after treatment with IL-1β (10 ng mL(-1) ). CONCLUSION This study shows that TNF-α, IL-1β, EGF and bFGF can modify the expression and function of endothelin receptors during organ culture. Because there is similar receptor upregulation in experimental stroke, the effect of cytokines and growth factors on endothelin receptor upregulation is an interesting aspect to study in vivo.
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Affiliation(s)
- H. Ahnstedt
- Division of Experimental Vascular Research; Department of Clinical Sciences; Lund University; Lund; Sweden
| | - E. Stenman
- Division of Experimental Vascular Research; Department of Clinical Sciences; Lund University; Lund; Sweden
| | - L. Cao
- Division of Experimental Vascular Research; Department of Clinical Sciences; Lund University; Lund; Sweden
| | - M. Henriksson
- Division of Experimental Vascular Research; Department of Clinical Sciences; Lund University; Lund; Sweden
| | - L. Edvinsson
- Division of Experimental Vascular Research; Department of Clinical Sciences; Lund University; Lund; Sweden
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Inhibition of cerebrovascular raf activation attenuates cerebral blood flow and prevents upregulation of contractile receptors after subarachnoid hemorrhage. BMC Neurosci 2011; 12:107. [PMID: 22032648 PMCID: PMC3219635 DOI: 10.1186/1471-2202-12-107] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2011] [Accepted: 10/27/2011] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Late cerebral ischemia carries high morbidity and mortality after subarachnoid hemorrhage (SAH) due to reduced cerebral blood flow (CBF) and the subsequent cerebral ischemia which is associated with upregulation of contractile receptors in the vascular smooth muscle cells (SMC) via activation of mitogen-activated protein kinase (MAPK) of the extracellular signal-regulated kinase (ERK)1/2 signal pathway. We hypothesize that SAH initiates cerebrovascular ERK1/2 activation, resulting in receptor upregulation. The raf inhibitor will inhibit the molecular events upstream ERK1/2 and may provide a therapeutic window for treatment of cerebral ischemia after SAH. RESULTS Here we demonstrate that SAH increases the phosphorylation level of ERK1/2 in cerebral vessels and reduces the neurology score in rats in additional with the CBF measured by an autoradiographic method. The intracisternal administration of SB-386023-b, a specific inhibitor of raf, given 6 h after SAH, aborts the receptor changes and protects the brain from the development of late cerebral ischemia at 48 h. This is accompanied by reduced phosphorylation of ERK1/2 in cerebrovascular SMC. SAH per se enhances contractile responses to endothelin-1 (ET-1), 5-carboxamidotryptamine (5-CT) and angiotensin II (Ang II), upregulates ETB, 5-HT1B and AT1 receptor mRNA and protein levels. Treatment with SB-386023-b given as late as at 6 h but not at 12 h after the SAH significantly decreased the receptor upregulation, the reduction in CBF and the neurology score. CONCLUSION These results provide evidence for a role of the ERK1/2 pathway in regulation of expression of cerebrovascular SMC receptors. It is suggested that raf inhibition may reduce late cerebral ischemia after SAH and provides a realistic time window for therapy.
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Edvinsson L, Povlsen GK. Late cerebral ischaemia after subarachnoid haemorrhage: is cerebrovascular receptor upregulation the mechanism behind? Acta Physiol (Oxf) 2011; 203:209-24. [PMID: 21087418 DOI: 10.1111/j.1748-1716.2010.02227.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Late cerebral ischaemia after subarachnoid haemorrhage (SAH) carries high morbidity and mortality because of reduced cerebral blood flow (CBF) and subsequent cerebral ischaemia. This is associated with upregulation of contractile receptors in cerebral artery smooth muscles via the activation of intracellular signalling. In addition, delayed cerebral ischaemia after SAH is associated with inflammation and disruption of the blood-brain barrier (BBB). This article reviews recent evidence concerning the roles of vasoconstrictor receptor upregulation, inflammation and BBB breakdown in delayed cerebral ischaemia after SAH. In addition, recent studies investigating the role of various intracellular signalling pathways in these processes and the possibilities of targeting signalling components in SAH treatment are discussed. Studies using a rat SAH model have demonstrated that cerebral arteries increase their sensitivity to endogenous agonists such as ET-1 and 5-HT by increasing their smooth muscle expression of receptors for these after SAH. This is associated with reduced CBF and neurological deficits. A number of signal transduction components mediating this receptor upregulation have been identified, including the MEK-ERK1/2 pathway. Inhibition of MEK-ERK1/2 signalling has been shown to prevent cerebrovascular receptor upregulation and normalize CBF and neurological function after SAH in rats. At the same time, in rat SAH, certain cytokines and BBB-regulating proteins are upregulated in cerebral artery smooth muscles and treatment with MEK-ERK1/2 inhibitors prevents the induction of these proteins. Thus, inhibitors of MEK-ERK1/2 signalling exert multimodal beneficial effects in SAH.
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Affiliation(s)
- L Edvinsson
- Department of Medicine, Institute of Clinical Sciences, University of Lund, Sweden.
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Maddahi A, Kruse LS, Chen QW, Edvinsson L. The role of tumor necrosis factor-α and TNF-α receptors in cerebral arteries following cerebral ischemia in rat. J Neuroinflammation 2011; 8:107. [PMID: 21871121 PMCID: PMC3177895 DOI: 10.1186/1742-2094-8-107] [Citation(s) in RCA: 68] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2011] [Accepted: 08/28/2011] [Indexed: 12/21/2022] Open
Abstract
Background Tumour necrosis factor-α (TNF-α) is a pleiotropic pro-inflammatory cytokine, which is rapidly upregulated in the brain after injury. TNF-α acts by binding to its receptors, TNF-R1 (p55) and TNF-R2 (p75), on the cell surface. The aim of this study was first to investigate if there is altered expression of TNF-α and TNF-α receptors in cerebral artery walls following global or focal ischemia, and after organ culture. Secondly, we asked if the expression was regulated via activation of the MEK-ERK1/2 pathway. Methods The hypothesis was tested in vivo after subarachnoid hemorrhage (SAH) and middle cerebral artery occlusion (MCAO), and in vitro by organ culture of isolated cerebral arteries. The localization and amount of TNF-α, TNF-α receptor 1 and 2 proteins were analysed by immunohistochemistry and western blot after 24 and 48 h of organ culture and at 48 h following SAH or MCAO. In addition, cerebral arteries were incubated for 24 or 48 h in the absence or presence of a B-Raf inhibitor (SB386023-b), a MEK- inhibitor (U0126) or an NF-κB inhibitor (IMD-0354), and protein expression evaluated. Results Immunohistochemistry revealed enhanced expression of TNF-α, TNF-R1 and TNF-R2 in the walls of cerebral arteries at 48 h after MCAO and SAH compared with control. Co-localization studies showed that TNF-α, TNF-R1 and TNF-R2 were primarily localized to the cell membrane and the cytoplasm of the smooth muscle cells (SMC). There was, in addition, some expression of TNF-R2 in the endothelial cells. Immunohistochemistry and western blot analysis showed that these proteins were upregulated after 24 and 48 h in culture, and this upregulation reached an apparent maximum at 48 h of organ culture. Treatment with U0126 significantly reduced the enhanced SMC expression of TNF-α, TNF-R1 and TNF-R2 immunoreactivities after 24 and 48 h of organ culture. The Raf and NF-κB inhibitors significantly reduced organ culture induced TNF-α expression while they had minor effects on the TNF-α receptors. Conclusion The present study shows that cerebral ischemia and organ culture induce expression of TNF-α and its receptors in the walls of cerebral arteries and that upregulation is transcriptionally regulated via the MEK/ERK pathway.
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Affiliation(s)
- Aida Maddahi
- Department of Clinical Sciences, Division of Experimental Vascular Research, Lund University, Lund, Sweden.
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Edvinsson LIH, Povlsen GK. Vascular plasticity in cerebrovascular disorders. J Cereb Blood Flow Metab 2011; 31:1554-71. [PMID: 21559027 PMCID: PMC3137480 DOI: 10.1038/jcbfm.2011.70] [Citation(s) in RCA: 79] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/17/2011] [Revised: 04/06/2011] [Accepted: 04/06/2011] [Indexed: 12/31/2022]
Abstract
Cerebral ischemia remains a major cause of morbidity and mortality with little advancement in subacute treatment options. This review aims to cover and discuss novel insight obtained during the last decade into plastic changes in the vasoconstrictor receptor profiles of cerebral arteries and microvessels that takes place after different types of stroke. Receptors like the endothelin type B, angiotensin type 1, and 5-hydroxytryptamine type 1B/1D receptors are upregulated in the smooth muscle layer of cerebral arteries after different types of ischemic stroke as well as after subarachnoid hemorrhage, yielding rather dramatic changes in the contractility of the vessels. Some of the signal transduction processes mediating this receptor upregulation have been elucidated. In particular the extracellular regulated kinase 1/2 pathway, which is activated early in the process, has proven to be a promising therapeutic target for prevention of vasoconstrictor receptor upregulation after stroke. Together, those findings provide new perspectives on the pathophysiology of ischemic stroke and point toward a novel way of reducing vasoconstriction, neuronal cell death, and thus neurologic deficits after stroke.
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Affiliation(s)
- Lars I H Edvinsson
- Department of Clinical Experimental Research, Copenhagen University, Glostrup Hospital Research Park, Copenhagen, Denmark.
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Ahnstedt H, Säveland H, Nilsson O, Edvinsson L. Human cerebrovascular contractile receptors are upregulated via a B-Raf/MEK/ERK-sensitive signaling pathway. BMC Neurosci 2011; 12:5. [PMID: 21223556 PMCID: PMC3023719 DOI: 10.1186/1471-2202-12-5] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2010] [Accepted: 01/11/2011] [Indexed: 11/11/2022] Open
Abstract
Background Cerebral ischemia results in a rapid increase in contractile cerebrovascular receptors, such as the 5-hydroxytryptamine type 1B (5-HT1B), angiotensin II type 1 (AT1), and endothelin type B (ETB) receptors, in the vessel walls within the ischemic region, which further impairs local blood flow and aggravates tissue damage. This receptor upregulation occurs via activation of the mitogen-activated protein kinase pathway. We therefore hypothesized an important role for B-Raf, the first signaling molecule in the pathway. To test our hypothesis, human cerebral arteries were incubated at 37°C for 48 h in the absence or presence of a B-Raf inhibitor: SB-386023 or SB-590885. Contractile properties were evaluated in a myograph and protein expression of the individual receptors and activated phosphorylated B-Raf (p-B-Raf) was evaluated immunohistochemically. Results 5-HT1B, AT1, and ETB receptor-mediated contractions were significantly reduced by application of SB-590885, and to a smaller extent by SB-386023. A marked reduction in AT1 receptor immunoreactivity was observed after treatment with SB-590885. Treatment with SB-590885 and SB-386023 diminished the culture-induced increase of p-B-Raf immunoreactivity. Conclusions B-Raf signaling has a key function in the altered expression of vascular contractile receptors observed after organ culture. Therefore, specific targeting of B-Raf might be a novel approach to reduce tissue damage after cerebral ischemia by preventing the previously observed upregulation of contractile receptors in smooth muscle cells.
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Affiliation(s)
- Hilda Ahnstedt
- Department of Clinical Sciences, Lund University, Sweden.
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Blockade of the MEK/ERK pathway with a raf inhibitor prevents activation of pro-inflammatory mediators in cerebral arteries and reduction in cerebral blood flow after subarachnoid hemorrhage in a rat model. J Cereb Blood Flow Metab 2011; 31:144-54. [PMID: 20424636 PMCID: PMC3049479 DOI: 10.1038/jcbfm.2010.62] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Cerebral ischemia that develops after subarachnoid hemorrhage (SAH) carries high morbidity and mortality. Inflammatory mediators are involved in the development of cerebral ischemia through activation of the mitogen-activated protein kinase pathway. We hypothesized that blockade of the MAPkinase/ERK (MEK)/extracellular signal-regulated kinase (ERK) pathway upstream with a specific raf inhibitor would prevent SAH-induced activation of the cerebrovascular inflammatory response. The raf inhibitor SB-386023-b was injected intracisternally in our rat model at 0, 6, or 12 hours after the SAH. After 48 hours, cerebral arteries were harvested, and iNOS, interleukin (IL)-6, IL-1β, matrix metalloproteinase (MMP)-9, tissue inhibitors of metalloproteinase (TIMP)-1, and phosphorylated ERK1/2 were investigated by immunofluorescence, real-time polymerase chain reaction (PCR), and Western blot analysis. Cerebral blood flow (CBF) was measured using autoradiography. Protein levels of MMP-9, TIMP-1, iNOS, IL-6, and IL-1β were increased after SAH, as were mRNA levels of IL-6, MMP-9, and TIMP-1. After SAH, pERK1/2 was increased, but CBF was reduced. Treatment with SB-386023-b at 0 or 6 hours after SAH normalized CBF and prevented SAH-induced upregulation of MMPs, pro-inflammatory cytokines, and pERK1/2 proteins. These results suggested that inhibition of MEK/ERK signal transduction by a specific raf inhibitor administered up to 6 hours after SAH normalized the expression of pro-inflammatory mediators and extracellular matrix-related genes.
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Suzuki H, Hasegawa Y, Kanamaru K, Zhang JH. Mitogen-activated protein kinases in cerebral vasospasm after subarachnoid hemorrhage: a review. ACTA NEUROCHIRURGICA. SUPPLEMENT 2011; 110:133-9. [PMID: 21116928 DOI: 10.1007/978-3-7091-0353-1_23] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
BACKGROUND Mitogen-activated protein kinases (MAPKs) have been implicated in the pathogenesis of cerebral vasospasm after subarachnoid hemorrhage. The goal of this review is to bring together recent diverse data concerning the roles of MAPKs in cerebral vasospasm and to consider the future research. METHOD A review of publications in the National Library of Medicine and National Institutes of Health database was conducted in August 2009 using specific keyword search terms pertaining to subarachnoid hemorrhage and MAPKs. FINDINGS There are nine in vitro studies and 17 in vivo studies published. Most of previous studies used MAPK inhibitors or their upstream molecule inhibitors, and showed that MAPK inhibitions prevented vasospasm. The MAPK cascade appears to interact with other signaling molecules, and MAPK may be an important final common pathway for the signaling transduction during cerebral vasospasm. However, the mechanism by which MAPK causes sustained vascular smooth muscle contraction remains unclear. In addition, the role of endogenous MAPK inhibitors, MAPK phosphatases, has not been investigated in cerebral vasospasm. CONCLUSIONS The experimental data support the causative role of MAPK in cerebral vasospasm and warrant further research.
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Affiliation(s)
- Hidenori Suzuki
- Department of Physiology, Loma Linda University School of Medicine, Risley Hall, Room 223, Loma Linda, CA 92354, USA
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Cui GY, Gao XM, Qi SH, Gillani A, Gao L, Shen X, Zhang YD. The action of thrombin in intracerebral hemorrhage induced brain damage is mediated via PKCα/PKCδ signaling. Brain Res 2010; 1398:86-93. [PMID: 21172324 DOI: 10.1016/j.brainres.2010.11.095] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2010] [Revised: 11/25/2010] [Accepted: 11/30/2010] [Indexed: 10/18/2022]
Abstract
The present study investigates the role of protein kinase C alpha/delta (PKCα/PKCδ) in brain injury induced by intracerebral hemorrhage (ICH) by utilizing a rat model that received intracerebral injections of autologous blood and thrombin (TM). The activation and expression of PKC and PKCδ were analyzed by Western blot and immunohistochemistry. A PKC inhibitor, dihydrochloride (H7), was administrated intraperitoneally after injury to evaluate the effect of inhibition of PKC on ICH and TM induced brain damage. Our data indicate that both ICH and TM increased the expression of PKCα/PKCδ in the brain tissue, and PKCα expression peaked at 6h, while PKCδ expression reached its maximum value at 72h post-injury. Administration of H7 significantly reduced the inflammatory cells infiltrate, permeability of brain-blood barrier (BBB), brain edema, and neuronal death. We conclude that both PKCα and PKCδ play important roles in ICH and TM-induced brain injury, and dihydrochloride (H7) can attenuate brain damage after ICH.
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Affiliation(s)
- Gui-Yun Cui
- Department of Neurology, Nanjing Brain Hospital, Nanjing Medical University, No. 264 Guangzhou Road, Nanjing 210029, PR China
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Neurogenic inflammation: a study of rat trigeminal ganglion. J Headache Pain 2010; 11:485-95. [PMID: 20931347 PMCID: PMC3476228 DOI: 10.1007/s10194-010-0260-x] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2010] [Accepted: 09/14/2010] [Indexed: 01/01/2023] Open
Abstract
Calcitonin gene-related peptide (CGRP) is linked to neurogenic inflammation and to migraine. Activation of the trigeminovascular system plays a prominent role during migraine attacks with the release of CGRP. The trigeminal ganglion (TG) contains three main cell types: neurons, satellite glial cells (SGC) and Schwann cells; the first two have before been studied in vitro separately. Culture of rat TG provides a method to induce inflammation and the possibility to evaluate the different cell types in the TG simultaneously. We investigated expression levels of various inflammatory cytokines on mRNA level using RT-PCR arrays and qRT-PCR; furthermore expression at protein level was studied using immunohistochemistry. We report that (1) organ culture of the TG is possible with preserved morphology, (2) organ culture is associated with enhanced expression of cytokines and mitogen-activated protein kinases (MAPKs) primarily in neurons, (3) CGRP can induce expression of some cytokines and (4) cytokine expression is still upregulated following MAPK pathway inhibition by MEK inhibitor U0126 and pp38 inhibitor SB202192, but the cytokine expression is abolished when co-incubating with the JNK inhibitor SP600125. This method may be of value to examine local TG inflammation, putatively involved in the pathophysiology of some forms of primary headaches.
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Xu CB, Sun Y, Edvinsson L. Cardiovascular risk factors regulate the expression of vascular endothelin receptors. Pharmacol Ther 2010; 127:148-55. [DOI: 10.1016/j.pharmthera.2010.04.013] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2010] [Accepted: 04/29/2010] [Indexed: 10/19/2022]
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Sandhu H, Ansar S, Edvinsson L. Comparison of MEK/ERK pathway inhibitors on the upregulation of vascular G-protein coupled receptors in rat cerebral arteries. Eur J Pharmacol 2010; 644:128-37. [PMID: 20615400 DOI: 10.1016/j.ejphar.2010.06.053] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2010] [Revised: 06/04/2010] [Accepted: 06/24/2010] [Indexed: 12/01/2022]
Abstract
Organ culture is an in vitro method for investigating cellular mechanisms involved in upregulation of vasocontractile G-protein coupled receptors. We hypothesize that mitogen-activated-protein kinase (MEK) and/or extracellular-signal-regulated kinase (ERK) specific inhibitors will attenuate the G-protein coupled receptor expression following organ culture. Rat cerebral arteries were incubated 48h in the presence of MEK/ERK specific inhibitors U0126, PD98059, SL327, or AG126 for different time periods. Contractile responses by activation of endothelin receptor type A and type B, serotonin receptor 5-HT(1B), prostanoid TP receptor, and angiotensin II receptor type 1 and type 2 were investigated. Results were verified by measurement of mRNA with real time PCR and by protein immunohistochemistry. Organ culture induced transcriptional upregulation of endothelin ET(B) receptor and of serotonin 5-HT(1B) receptor on translational level and increased respective contractions. The prostanoid TP receptor mediated contraction curve was left-wards shifted by organ culture. Organ culture was associated with elevated pERK1/2 in the vascular smooth muscle cells: the MEK1/2 inhibitor U0126 attenuated the endothelin ET(B) receptor mediated contraction at post-translational level or by changing the receptor affinities. The serotonin 5-HT(1B) receptor and prostanoid TP receptor mediated contractions were abolished by U0126. Administration of U0126 6h after start of incubation blocked the receptor upregulation. In conclusion, MEK specific inhibitor U0126 is a potent inhibitor of G-protein coupled receptor alteration seen during organ culture. Given the ability to inhibit G-protein coupled receptor alteration at the clinically relevant time-point 6h post incubation makes it an attractive therapeutic agent for in vivo studies.
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Affiliation(s)
- Hardip Sandhu
- Department of Clinical Experimental Research, Glostrup Research Institute, Glostrup University Hospital, Denmark.
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Larsen CC, Povlsen GK, Rasmussen MNP, Edvinsson L. Improvement in neurological outcome and abolition of cerebrovascular endothelin B and 5-hydroxytryptamine 1B receptor upregulation through mitogen-activated protein kinase kinase 1/2 inhibition after subarachnoid hemorrhage in rats. J Neurosurg 2010; 114:1143-53. [PMID: 20597604 DOI: 10.3171/2010.6.jns1018] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
OBJECT Delayed cerebral ischemia after subarachnoid hemorrhage (SAH) remains a major cause of death and disability. It has been hypothesized that cerebrovascular upregulation of vasoconstrictor receptors is a key step in the development of delayed cerebral ischemia. Upregulation of endothelin-B (ET(B)) and 5-hydroxytryptamine 1B (5-HT(1B)) receptors has been demonstrated in cerebral artery smooth muscles in the delayed ischemic phase after experimental SAH, and intracellular signaling via the mitogen-activated protein kinase kinase (MEK)-extracellular signal-regulated kinase 1/2 pathway has been shown to be involved in this upregulation. The aim in the present study was to determine whether treatment with the MEK1/2 inhibitor U0126 can prevent cerebrovascular receptor upregulation and improve functional outcome after experimental SAH in rats. METHODS Subarachnoid hemorrhage was induced in male Sprague-Dawley rats by the injection of 250 μl of autologous blood into the basal cisterns. Either U0126 or vehicle was intracisternally administered at 6, 12, 24, and 36 hours after SAH. Smooth muscle ET(B) and 5-HT(1B) receptor upregulation was studied in isolated cerebral artery segments through immunohistochemical and myographic studies of contractile responses to receptor-specific agonists. Gross sensorimotor function in the rats after SAH was assessed using a rotating pole test. RESULTS Contractile concentration-response curves for middle cerebral artery (MCA) and basilar artery (BA) segments to endothelin-1 (ET-1) and 5-carboxamidotryptamine (5-CT) were shifted leftward for SAH-induced compared with shamoperated rats due to enhanced contractile responses to individual doses of the agonists (for example, contractile responses of the BA to 3 × 10(-10) M of ET-1 and 3 × 10(-7) M of 5-CT were 9.98 ± 5.01% and 16.75 ± 3.62% of the maximal contractile capacity, respectively, in sham-operated rats and 62.78 ± 9.9% and 45.44 ± 10.62%, respectively, in SAH-induced rats). In vivo treatment with 0.19 μg/kg U0126 normalized responses in the SAH-induced rats to levels in the sham-operated rats. Protein expression of ET(B) and 5-HT(1B) receptors in cerebrovascular smooth muscles from SAH-induced rats was increased to 175 ± 33.17% and 167.7 ± 24.74%, respectively, of the levels in sham-operated rats. Endothelin-B and 5-HT(1B) expression levels in U0126-treated SAH-induced rats were at the levels in sham-operated rats (101.9 ± 13.38% and 91.44 ± 16.75%, respectively). In a rotating pole test used to assess gross sensorimotor function on the 2nd day after surgery, sham-operated rats achieved an average score of 5.37 ± 0.23, SAH-induced rats scored 3.35 ± 0.67, and SAH-induced U0126-treated rats scored 5.00 ± 0.4. CONCLUSIONS The authors demonstrated that experimental SAH induces upregulation of ET(B) and 5-HT(1B) receptors in cerebrovascular smooth muscles and that treatment with the MEK1/2 inhibitor U0126 abolishes this receptor upregulation. They also demonstrated that experimental SAH results in sensorimotor deficits as assessed by a rotating pole test. These deficits were alleviated by U0126 treatment, suggesting that cerebrovascular receptor upregulation is critical for the functional outcome of delayed cerebral ischemia. The authors suggest that inhibition of MEK1/2 may be a promising new SAH treatment strategy.
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NF-kappaB signaling mediates vascular smooth muscle endothelin type B receptor expression in resistance arteries. Eur J Pharmacol 2010; 637:148-54. [DOI: 10.1016/j.ejphar.2010.04.006] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2009] [Revised: 03/09/2010] [Accepted: 04/04/2010] [Indexed: 12/15/2022]
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Maddahi A, Edvinsson L. Cerebral ischemia induces microvascular pro-inflammatory cytokine expression via the MEK/ERK pathway. J Neuroinflammation 2010; 7:14. [PMID: 20187933 PMCID: PMC2837637 DOI: 10.1186/1742-2094-7-14] [Citation(s) in RCA: 106] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2010] [Accepted: 02/26/2010] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Cerebral ischemia from middle cerebral artery wall (MCA) occlusion results in increased expression of cerebrovascular endothelin and angiotensin receptors and activation of the mitogen-activated protein kinase (MAPK) pathway, as well as reduced local cerebral blood flow and increased levels of pro-inflammatory mediators in the infarct region. In this study, we hypothesised that inhibition of the cerebrovascular inflammatory reaction with a specific MEK1/2 inhibitor (U0126) to block transcription or a combined receptor blockade would reduce infarct size and improve neurological score. METHODS Rats were subjected to a 2-hours middle cerebral artery occlusion (MCAO) followed by reperfusion for 48 hours. Two groups of treated animals were studied; (i) one group received intraperitoneal administration of a specific MEK1/2 inhibitor (U0126) starting at 0, 6, or 12 hours after the occlusion, and (ii) a second group received two specific receptor antagonists (a combination of the angiotensin AT1 receptor inhibitor Candesartan and the endothelin ETA receptor antagonist ZD1611), given immediately after occlusion. The middle cerebral arteries, microvessels and brain tissue were harvested; and the expressions of tumor necrosis factor-alpha (TNF-alpha), interleukin-1ss (IL-1ss), interleukin-6 (IL-6), inducible nitric oxide synthase (iNOS) and phosphorylated ERK1/2, p38 and JNK were analysed using immunohistochemistry. RESULTS We observed an infarct volume of 25 +/- 2% of total brain volume, and reduced neurological function 2 days after MCAO followed by 48 hours of recirculation. Immunohistochemistry revealed enhanced expression of TNF-alpha, IL-1ss, IL-6 and iNOS, as well as elevated levels of phosphorylated ERK1/2 in smooth muscle cells of ischemic MCA and in associated intracerebral microvessels. U0126, given intraperitoneal at zero or 6 hours after the ischemic event, but not at 12 hours, reduced the infarct volume (11.7 +/- 2% and 15 +/- 3%, respectively), normalized pERK1/2, and prevented elevation of the expressions of TNF-alpha IL-1ss, IL-6 and iNOS. Combined inhibition of angiotensin AT1 and endothelin ETA receptors decreased the volume of brain damaged (12.3 +/- 3; P < 0.05) but only slightly reduced MCAO-induced enhanced expression of iNOS and cytokines CONCLUSION The present study shows elevated microvascular expression of TNF-alpha, IL-1ss, IL-6 and iNOS following focal ischemia, and shows that this expression is transcriptionally regulated via the MEK/ERK pathway.
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Affiliation(s)
- Aida Maddahi
- Department of Internal Medicine, Institute of Clinical Sciences, Lund University, Sweden.
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Oxidized low-density lipoprotein-induced matrix metalloproteinase-9 expression via PKC-delta/p42/p44 MAPK/Elk-1 cascade in brain astrocytes. Neurotox Res 2009; 17:50-65. [PMID: 19554388 DOI: 10.1007/s12640-009-9077-2] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2009] [Accepted: 06/15/2009] [Indexed: 10/20/2022]
Abstract
After ischemic injury to brain, disruption of the blood-brain barrier (BBB) raises the possibility of exposing the central nervous system (CNS) to oxidized low-density lipoprotein (oxLDL), a risk factor implicated in neurodegenerative diseases. Matrix metalloproteinases (MMPs), especially MMP-9, contribute to extracellular matrix (ECM) remodeling during the CNS diseases. However, the molecular mechanisms underlying oxLDL-induced MMP-9 expression in astrocytes remained unclear. Here, we reported that oxLDL induced MMP-9 expression via a PKC-delta/p42/p44 MAPK-dependent Elk-1 activation in rat brain astrocyte (RBA)-1 cells, revealed by gelatin zymography, RT-PCR, and Western blotting analyses. These responses were attenuated by pretreatment with pharmacological inhibitors and transfection with dominant negative mutants. Moreover, Elk-1-mediated MMP-9 gene transcription was confirmed by transfection with an Elk-1 binding site-mutated MMP-9 promoter construct (mt-Ets-MMP9), which blocked oxLDL-stimulated MMP-9 luciferase activity. Understanding the regulatory mechanisms by which oxLDL induced MMP-9 expression in astrocytes might provide a new therapeutic strategy of brain diseases.
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Cetas JS, Lee DR, Alkayed NJ, Wang R, Iliff JJ, Heinricher MM. Brainstem control of cerebral blood flow and application to acute vasospasm following experimental subarachnoid hemorrhage. Neuroscience 2009; 163:719-29. [PMID: 19539726 DOI: 10.1016/j.neuroscience.2009.06.031] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2009] [Revised: 06/10/2009] [Accepted: 06/12/2009] [Indexed: 11/19/2022]
Abstract
Symptomatic ischemia following aneurysmal subarachnoid hemorrhage (SAH) is common but poorly understood and inadequately treated. Severe constriction of the major arteries at the base of the brain, termed vasospasm, traditionally has been thought to be a proximal event underlying these ischemias, although microvascular changes also have been described. The vast majority of studies aimed at understanding the pathogenesis of ischemic deficits, and vasospasm have focused on the interaction of the "spasmogen" of the extravasated blood with the smooth muscle and endothelium of the arteries. This has led to a comparative neglect of the contribution of the CNS to the maintenance of cerebral perfusion. In the present study, we focused on the role of the rostral ventromedial medulla (RVM) in modulating cerebral perfusion at rest and following an experimental SAH in the rat. Changes in cerebral blood flow (CBF) were measured using laser-Doppler flowmetry and three-dimensional optical microangiography. Focal application of a GABA(A) receptor agonist and antagonist was used to respectively inactivate and activate the RVM. We show here that the RVM modulates cerebral blood flow under resting conditions, and further, contributes to restoration of cerebral perfusion following a high-grade SAH. Failure of this brainstem compensatory mechanism could be significant for acute perfusion deficits seen in patients following subarachnoid hemorrhage.
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Affiliation(s)
- J S Cetas
- Department of Neurological Surgery, Oregon Health & Science University, 3181 Southwest Sam Jackson Park Road, Portland, OR 97239-3098, USA.
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Maddahi A, Chen Q, Edvinsson L. Enhanced cerebrovascular expression of matrix metalloproteinase-9 and tissue inhibitor of metalloproteinase-1 via the MEK/ERK pathway during cerebral ischemia in the rat. BMC Neurosci 2009; 10:56. [PMID: 19497125 PMCID: PMC2700114 DOI: 10.1186/1471-2202-10-56] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2008] [Accepted: 06/04/2009] [Indexed: 12/30/2022] Open
Abstract
Background Cerebral ischemia is usually characterized by a reduction in local blood flow and metabolism and by disruption of the blood-brain barrier in the infarct region. The formation of oedema and opening of the blood-brain barrier in stroke is associated with enhanced expression of metalloproteinase-9 (MMP-9) and tissue inhibitor of metalloproteinase-1 (TIMP-1). Results Here, we found an infarct volume of 24.8 ± 2% and a reduced neurological function after two hours of middle cerebral artery occlusion (MCAO), followed by 48 hours of recirculation in rat. Immunocytochemistry and confocal microscopy revealed enhanced expression of MMP-9, TIMP-1, and phosphorylated ERK1/2 in the smooth muscle cells of the ischemic MCA and associated intracerebral microvessels. The specific MEK1/2 inhibitor U0126, given intraperitoneal zero or 6 hours after the ischemic event, reduced the infarct volume significantly (11.8 ± 2% and 14.6 ± 3%, respectively; P < 0.05), improved neurological function, normalized expression of phosphorylated ERK1/2, and reduced expression of MMP-9 and TIMP-1 in the vessel walls. Administration of U0126 12 hours after MCAO did not alter the expression of MMP-9. Immunocytochemistry showed no overlap in expression between MMP-9/TIMP-1 and the astrocyte/glial cell marker GFAP in the vessel walls. Conclusion These data are the first to show that the elevated vascular expression of MMP-9 and TIMP-1, associated with breakdown of the blood-brain barrier following focal ischemia, are transcriptionally regulated via the MEK/ERK pathway.
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Affiliation(s)
- Aida Maddahi
- Department of Clinical Sciences, Division of Experimental Vascular Research, Lund University, Lund, Sweden.
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van der Merwe JQ, Moreau F, MacNaughton WK. Protease-activated receptor-2 stimulates intestinal epithelial chloride transport through activation of PLC and selective PKC isoforms. Am J Physiol Gastrointest Liver Physiol 2009; 296:G1258-66. [PMID: 19359428 DOI: 10.1152/ajpgi.90425.2008] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Serine proteases play important physiological roles through their activity at G protein-coupled protease-activated receptors (PARs). We examined the roles that specific phospholipase (PL) C and protein kinase (PK) C (PKC) isoforms play in the regulation of PAR(2)-stimulated chloride secretion in intestinal epithelial cells. Confluent SCBN epithelial monolayers were grown on Snapwell supports and mounted in modified Ussing chambers. Short-circuit current (I(sc)) responses to basolateral application of the selective PAR(2) activating peptide, SLIGRL-NH(2), were monitored as a measure of net electrogenic ion transport caused by PAR(2) activation. SLIGRL-NH(2) induced a transient I(sc) response that was significantly reduced by inhibitors of PLC (U73122), phosphoinositol-PLC (ET-18), phosphatidylcholine-PLC (D609), and phosphatidylinositol 3-kinase (PI3K; LY294002). Immunoblot analysis revealed the phosphorylation of both PLCbeta and PLCgamma following PAR(2) activation. Pretreatment of the cells with inhibitors of PKC (GF 109203X), PKCalpha/betaI (Gö6976), and PKCdelta (rottlerin), but not PKCzeta (selective pseudosubstrate inhibitor), also attenuated this response. Cellular fractionation and immunoblot analysis, as well as confocal immunocytochemistry, revealed increases of PKCbetaI, PKCdelta, and PKCepsilon, but not PKCalpha or PKCzeta, in membrane fractions following PAR(2) activation. Pretreatment of the cells with U73122, ET-18, or D609 inhibited PKC activation. Inhibition of PI3K activity only prevented PKCdelta translocation. Immunoblots revealed that PAR(2) activation induced phosphorylation of both cRaf and ERK1/2 via PKCdelta. Inhibition of PKCbetaI and PI3K had only a partial effect on this response. We conclude that basolateral PAR(2)-induced chloride secretion involves activation of PKCbetaI and PKCdelta via a PLC-dependent mechanism resulting in the stimulation of cRaf and ERK1/2 signaling.
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