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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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Blixt FW, Haanes KA, Ohlsson L, Dreisig K, Fedulov V, Warfvinge K, Edvinsson L. MEK/ERK/1/2 sensitive vascular changes coincide with retinal functional deficit, following transient ophthalmic artery occlusion. Exp Eye Res 2018; 179:142-149. [PMID: 30439349 DOI: 10.1016/j.exer.2018.11.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2018] [Revised: 10/22/2018] [Accepted: 11/05/2018] [Indexed: 11/27/2022]
Abstract
Retinal ischemia remains a major cause of blindness in the world with few acute treatments available. Recent emphasis on retinal vasculature and the ophthalmic artery's vascular properties after ischemia has shown an increase in vasoconstrictive functionality, as previously observed in cerebral arteries following stroke. Specifically, endothelin-1 (ET-1) receptor-mediated vasoconstriction regulated by the MEK/ERK1/2 pathway. In this study, the ophthalmic artery of rats was occluded for 2 h with the middle cerebral artery occlusion model. MEK/ERK1/2 inhibitor U0126 was administered at 0, 6, and 24 h following reperfusion and the functional properties of the ophthalmic artery were evaluated at 48 h post reperfusion. Additionally, retinal function was evaluated at day 1, 4, and 7 after reperfusion. Occlusion of the ophthalmic artery led to a significant increase of endothelin-1 mediated vasoconstriction which can be attenuated by U0126 treatment, most evident at higher ET-1 concentrations of 10-7 M (Emax151.0 ± 22.0% of 60 mM K+), vs non-treated ischemic arteries Emax 212.1 ± 14.7% of 60 mM K+). Retinal function also deteriorated following ischemia and was improved with treatment with a-wave amplitudes of 725 ± 36 μV in control, 560 ± 21 μV in non-treated, and 668 ± 73 μV in U0126 treated at 2 log cd*s/m2 luminance in the acute stages (1 days post-ischemia). Full spontaneous retinal recovery was observed at day 7 regardless of treatment. In conclusion, this is the first study to show a beneficial in vivo effect of U0126 on vascular contractility following ischemia in the ophthalmic artery. Coupled with the knowledge obtained from cerebral vasculature, these results point towards a novel therapeutic approach following ischemia-related injuries to the eye.
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Affiliation(s)
- Frank W Blixt
- Department of Clinical Sciences, Division of Experimental Vascular Research, Lund University, Lund, Sweden.
| | - Kristian Agmund Haanes
- Department of Clinical Experimental Research, Glostrup Research Institute, Rigshospitalet, Glostrup, Denmark
| | - Lena Ohlsson
- Department of Clinical Sciences, Division of Experimental Vascular Research, Lund University, Lund, Sweden
| | - Karin Dreisig
- Department of Clinical Experimental Research, Glostrup Research Institute, Rigshospitalet, Glostrup, Denmark
| | - Vadim Fedulov
- Department of Clinical Experimental Research, Glostrup Research Institute, Rigshospitalet, Glostrup, Denmark
| | - Karin Warfvinge
- Department of Clinical Sciences, Division of Experimental Vascular Research, Lund University, Lund, Sweden; Department of Clinical Experimental Research, Glostrup Research Institute, Rigshospitalet, Glostrup, Denmark
| | - Lars Edvinsson
- Department of Clinical Sciences, Division of Experimental Vascular Research, Lund University, Lund, Sweden; Department of Clinical Experimental Research, Glostrup Research Institute, Rigshospitalet, Glostrup, Denmark
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Li W, Abdul Y, Ward R, Ergul A. Endothelin and diabetic complications: a brain-centric view. Physiol Res 2018; 67:S83-S94. [PMID: 29947530 DOI: 10.33549/physiolres.933833] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The global epidemic of diabetes is of significant concern. Diabetes associated vascular disease signifies the principal cause of morbidity and mortality in diabetic patients. It is also the most rapidly increasing risk factor for cognitive impairment, a silent disease that causes loss of creativity, productivity, and quality of life. Small vessel disease in the cerebral vasculature plays a major role in the pathogenesis of cognitive impairment in diabetes. Endothelin system, including endothelin-1 (ET-1) and the receptors (ET(A) and ET(B)), is a likely candidate that may be involved in many aspects of the diabetes cerebrovascular disease. In this review, we took a brain-centric approach and discussed the role of the ET system in cerebrovascular and cognitive dysfunction in diabetes.
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Affiliation(s)
- W Li
- Charlie Norwood Veterans Affairs Medical Center, Augusta, Georgia, USA, Department of Physiology, Augusta University, Augusta, Georgia, USA.
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4
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Blixt FW, Haanes KA, Ohlsson L, Tolstrup Christiansen A, Warfvinge K, Edvinsson L. Increased endothelin-1-mediated vasoconstriction after organ culture in rat and pig ocular arteries can be suppressed with MEK/ERK1/2 inhibitors. Acta Ophthalmol 2018; 96:e619-e625. [PMID: 29369532 DOI: 10.1111/aos.13651] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2016] [Accepted: 10/23/2017] [Indexed: 01/19/2023]
Abstract
PURPOSE Even though retinal vascular changes following ischaemia have been poorly understood, the upregulation of vasoconstrictive endothelin-1 (ET-1) receptors (ETA /ETB ) following global cerebral ischaemia has been described. The aim of this study was to investigate whether or not the MEK/ERK1/2 pathway is involved in the observed upregulation and whether specific MEK/ERK1/2 inhibitors U0126 and trametinib can prevent it. METHODS The aim was also to localize ETA and ETB receptors using immunohistochemistry in both fresh rat ophthalmic arteries and after 24-hr organ culture and study the receptors functionally using myography. Pig retinal arteries also underwent 24-hr organ culture to validate similar responses across species and the retinal vasculature. RESULTS Results showed that following organ culture there is a significant increase in ET-1-mediated vasoconstriction, in particular via the ETB receptor. Furthermore, immunohistochemistry revealed a clear increase in pERK in the smooth muscle cells of rat ophthalmic artery. U0126 and trametinib were successful in attenuating the functional vasoconstriction in both rat and pig, as well as restoring immunofluorescence of pERK to fresh levels and counteracting ETB expression in the smooth muscle cells of the rat ophthalmic artery. CONCLUSION This is the first study to show that the MEK/ERK1/2 pathway in responsible for the increase in functional vasoconstriction via ET-1 receptor in rat ophthalmic and pig retinal arteries. Furthermore, this study is the first to suggest a way of inhibiting and preventing such an increase. With these results, we suggest a novel approach in retinal ischaemia therapy.
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Affiliation(s)
- Frank W. Blixt
- Department of Clinical Sciences; Division of Experimental Vascular Research; Lund University; Lund Sweden
| | - Kristian Agmund Haanes
- Department of Clinical Experimental Research; Glostrup Research Institute; Rigshospitalet; Glostrup Denmark
| | - Lena Ohlsson
- Department of Clinical Sciences; Division of Experimental Vascular Research; Lund University; Lund Sweden
| | | | - Karin Warfvinge
- Department of Clinical Experimental Research; Glostrup Research Institute; Rigshospitalet; Glostrup Denmark
| | - Lars Edvinsson
- Department of Clinical Sciences; Division of Experimental Vascular Research; Lund University; Lund Sweden
- Department of Clinical Experimental Research; Glostrup Research Institute; Rigshospitalet; Glostrup Denmark
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Assenzio B, Martin EL, Stankevicius E, Civiletti F, Fontanella M, Boccaletti R, Berardino M, Mazzeo A, Ducati A, Simonsen U, Mascia L. Cerebrospinal fluid from patients with subarachnoid haemorrhage and vasospasm enhances endothelin contraction in rat cerebral arteries. PLoS One 2015; 10:e0116456. [PMID: 25629621 PMCID: PMC4309584 DOI: 10.1371/journal.pone.0116456] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2014] [Accepted: 12/10/2014] [Indexed: 11/18/2022] Open
Abstract
INTRODUCTION Previous studies have suggested that cerebrospinal fluid from patients with subarachnoid hemorrhage (SAH) leads to pronounced vasoconstriction in isolated arteries. We hypothesized that only cerebrospinal fluid from SAH patients with vasospasm would produce an enhanced contractile response to endothelin-1 in rat cerebral arteries, involving both endothelin ETA and ETB receptors. METHODS Intact rat basilar arteries were incubated for 24 hours with cerebrospinal fluid from 1) SAH patients with vasospasm, 2) SAH patients without vasospasm, and 3) control patients. Arterial segments with and without endothelium were mounted in myographs and concentration-response curves for endothelin-1 were constructed in the absence and presence of selective and combined ETA and ETB receptor antagonists. Endothelin concentrations in culture medium and receptor expression were measured. RESULTS Compared to the other groups, the following was observed in arteries exposed to cerebrospinal fluid from patients with vasospasm: 1) larger contractions at lower endothelin concentrations (p<0.05); 2) the increased endothelin contraction was absent in arteries without endothelium; 3) higher levels of endothelin secretion in the culture medium (p<0.05); 4) there was expression of ETA receptors and new expression of ETB receptors was apparent; 5) reduction in the enhanced response to endothelin after ETB blockade in the low range and after ETA blockade in the high range of endothelin concentrations; 6) after combined ETA and ETB blockade a complete inhibition of endothelin contraction was observed. CONCLUSIONS Our experimental findings showed that in intact rat basilar arteries exposed to cerebrospinal fluid from patients with vasospasm endothelin contraction was enhanced in an endothelium-dependent manner and was blocked by combined ETA and ETB receptor antagonism. Therefore we suggest that combined blockade of both receptors may play a role in counteracting vasospasm in patients with SAH.
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Affiliation(s)
- Barbara Assenzio
- Department of Anesthesia and Intensive Care, Azienda Ospedaliera Città della salute e della scienza di Torino, University of Turin, Turin, Italy
| | - Erica L. Martin
- Department of Anesthesia and Intensive Care, Azienda Ospedaliera Città della salute e della scienza di Torino, University of Turin, Turin, Italy
| | - Edgaras Stankevicius
- Institute of Physiology and Pharmacology, Medical Academy, Lithuanian University of Health Sciences, Kaunas, Lithuania
| | - Federica Civiletti
- Department of Anesthesia and Intensive Care, Azienda Ospedaliera Città della salute e della scienza di Torino, University of Turin, Turin, Italy
| | - Marco Fontanella
- Division of Neurosurgery, Department of Neuroscience, Azienda Ospedaliera Città della salute e della scienza di Torino, University of Turin, Turin, Italy
| | - Riccardo Boccaletti
- Division of Neurosurgery, Department of Neuroscience, Azienda Ospedaliera Città della salute e della scienza di Torino, University of Turin, Turin, Italy
| | - Maurizio Berardino
- Department of Anesthesia and Intensive Care, Azienda Ospedaliera Città della salute e della scienza di Torino, University of Turin, Turin, Italy
| | - AnnaTeresa Mazzeo
- Department of Anesthesia and Intensive Care, Azienda Ospedaliera Città della salute e della scienza di Torino, University of Turin, Turin, Italy
| | - Alessandro Ducati
- Division of Neurosurgery, Department of Neuroscience, Azienda Ospedaliera Città della salute e della scienza di Torino, University of Turin, Turin, Italy
| | - Ulf Simonsen
- Department of Biomedicine, Pulmonary and Cardiovascular Pharmacology, University of Aarhus, Aarhus, Denmark
| | - Luciana Mascia
- Department of Anesthesia and Intensive Care, Azienda Ospedaliera Città della salute e della scienza di Torino, University of Turin, Turin, Italy
- * E-mail:
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Edvinsson L, Povlsen GK, Ahnstedt H, Waldsee R. CaMKII inhibition with KN93 attenuates endothelin and serotonin receptor-mediated vasoconstriction and prevents subarachnoid hemorrhage-induced deficits in sensorimotor function. J Neuroinflammation 2014; 11:207. [PMID: 25498987 PMCID: PMC4269841 DOI: 10.1186/s12974-014-0207-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2014] [Accepted: 11/24/2014] [Indexed: 02/04/2023] Open
Abstract
Background It has been suggested that transcriptional upregulation of cerebral artery contractile endothelin (ETB) and 5-hydroxytryptamine (5-HT1B) receptors play an important role in the development of late cerebral ischemia and increased vasoconstriction after subarachnoid hemorrhage (SAH). We tested the hypothesis that inhibition of calcium calmodulin-dependent protein kinase II (CaMKII) may reduce cerebral vasoconstriction mediated by endothelin and serotonin receptors and improve neurological outcome after experimental SAH. Methods SAH was induced in adult rats by injection of 250 μL autologous blood into the basal cisterns. The CaMKII activity in cerebral vessels was studied by Western blot and immunohistochemistry. The vasomotor responses of middle cerebral and basilar arteries were measured in a sensitive myograph system. The functional outcome was examined by the rotating pole test 2 and 3 days after SAH. Results SAH induced a rapid early increase in phosphorylated CaMKII protein at 1 h that was attenuated by cisternal administration of the CaMKII inhibitor KN93 (0.501 μg/kg) 45 min prior and immediately after SAH as evaluated by Western blot. Application of KN93 at 1 h and every 12 h post-SAH significantly reduced vascular CaMKII immunoreactivity at 72 h. In addition, contractile responses of cerebral arteries to endothelin-1 (ET-1) and 5-hydroxycarboxamide (5-CT) were increased at this time-point. KN93 treatment significantly attenuated the contraction induced by ET-1 and 5-CT. Importantly, treatment with the CaMKII inhibitor prevented SAH-induced deficits in neurological function, as evaluated by the rotating pole test, and similar sensorimotor scores were seen in sham-operated animals. Conclusions The present study has shown that SAH is associated with increased contractile responses to ET-1 and 5-CT in cerebral arteries and enhanced early activation of CaMKII. Treatment with the CaMKII inhibitor KN93 attenuated the contractile responses and prevented impaired sensorimotor function after SAH.
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Affiliation(s)
- Lars Edvinsson
- Division of Experimental Vascular Research, Department of Clinical Sciences, Lund University and Lund University Hospital, Lund, SE-221 84, Sweden.
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Regulatory mechanism of endothelin receptor B in the cerebral arteries after focal cerebral ischemia. PLoS One 2014; 9:e113624. [PMID: 25479176 PMCID: PMC4257531 DOI: 10.1371/journal.pone.0113624] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2014] [Accepted: 10/29/2014] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND AND PURPOSE Increased expression of endothelin receptor type B (ETBR), a vasoactive receptor, has recently been implied in the reduced cerebral blood flow and exacerbated neuronal damage after ischemia-reperfusion (I/R). The study explores the regulatory mechanisms of ETBR to identify drug targets to restore normal cerebral artery contractile function as part of successful neuroprotective therapy. METHODS We have employed in vitro methods on human and rat cerebral arteries to study the regulatory mechanisms and the efficacy of target selective inhibitor, Mithramycin A (MitA), to block the ETBR mediated contractile properties. Later, middle cerebral artery occluded (MCAO) rats were used to substantiate the observations. Quantative PCR, immunohistochemistry, western blot and wire myograph methods were employed to study the expression and contractile properties of cerebral arteries. RESULTS Increased expression of specificity protein (Sp1) was observed in human and rat cerebral arteries after organ culture, strongly correlating with the ETBR upregulation. Similar observations were made in MCAO rats. Treatment with MitA, a Sp1 specific inhibitor, significantly downregulated the ETBR mRNA and protein levels. It also significantly reduced the ETBR mediated cerebrovascular contractility. Detailed analysis indicated that ERK1/2 mediated phosphorylation of Sp1 might be essential for ETBR transcription. CONCLUSION Transcription factor Sp1 regulates the ETBR mediated vasoconstriction in focal cerebral ischemia via MEK-ERK signaling, which is also conserved in humans. The results show that MitA can effectively be used to block ETBR mediated vasoconstriction as a supplement to an existing ischemic stroke therapy.
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PGD2 DP1 receptor stimulation following stroke ameliorates cerebral blood flow and outcomes. Neuroscience 2014; 279:260-8. [DOI: 10.1016/j.neuroscience.2014.08.050] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2014] [Revised: 08/18/2014] [Accepted: 08/29/2014] [Indexed: 01/05/2023]
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9
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Xu G, He J, Guo H, Mei C, Wang J, Li Z, Chen H, Mang J, Yang H, Xu Z. Activin A prevents neuron-like PC12 cell apoptosis after oxygen-glucose deprivation. Neural Regen Res 2014; 8:1016-24. [PMID: 25206395 PMCID: PMC4145885 DOI: 10.3969/j.issn.1673-5374.2013.11.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2012] [Accepted: 03/14/2013] [Indexed: 12/22/2022] Open
Abstract
In this study, PC12 cells were induced to differentiate into neuron-like cells using nerve growth factor, and were subjected to oxygen-glucose deprivation. Cells were treated with 0, 10, 20, 30, 50, 100 ng/mL exogenous Activin A. The 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl tetrazolium bromide assay and Hoechst 33324 staining showed that the survival percentage of PC12 cells significantly decreased and the rate of apoptosis significantly increased after oxygen-glucose deprivation. Exogenous Activin A significantly increased the survival percentage of PC12 cells in a dose-dependent manner. Reverse transcription-PCR results revealed a significant increase in Activin receptor IIA, Smad3 and Smad4 mRNA levels, which are key sites in the Activin A/Smads signaling pathway, in neuron-like cells subjected to oxygen-glucose deprivation, while mRNA expression of the apoptosis-regulation gene caspase-3 decreased. Our experimental findings indicate that exogenous Activin A plays an anti-apoptotic role and protects neurons by means of activating the Activin A/Smads signaling pathway.
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Affiliation(s)
- Guihua Xu
- Department of Neurology, China-Japan Union Hospital, Jilin University, Changchun 130033, Jilin Province, China ; Department of Neurology, Changchun Central Hospital, Changchun 130051, Jilin Province, China
| | - Jinting He
- Department of Neurology, China-Japan Union Hospital, Jilin University, Changchun 130033, Jilin Province, China
| | - Hongliang Guo
- Department of Neurology, China-Japan Union Hospital, Jilin University, Changchun 130033, Jilin Province, China
| | - Chunli Mei
- Department of Neurology, China-Japan Union Hospital, Jilin University, Changchun 130033, Jilin Province, China
| | - Jiaoqi Wang
- Department of Neurology, China-Japan Union Hospital, Jilin University, Changchun 130033, Jilin Province, China
| | - Zhongshu Li
- Department of Neurology, China-Japan Union Hospital, Jilin University, Changchun 130033, Jilin Province, China
| | - Han Chen
- Department of Neurology, China-Japan Union Hospital, Jilin University, Changchun 130033, Jilin Province, China
| | - Jing Mang
- Department of Neurology, China-Japan Union Hospital, Jilin University, Changchun 130033, Jilin Province, China
| | - Hong Yang
- Department of Neurology, China-Japan Union Hospital, Jilin University, Changchun 130033, Jilin Province, China
| | - Zhongxin Xu
- Department of Neurology, China-Japan Union Hospital, Jilin University, Changchun 130033, Jilin Province, China
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Characterization of the contractile P2Y14 receptor in mouse coronary and cerebral arteries. FEBS Lett 2014; 588:2936-43. [PMID: 24911208 DOI: 10.1016/j.febslet.2014.05.044] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2014] [Revised: 05/13/2014] [Accepted: 05/21/2014] [Indexed: 01/12/2023]
Abstract
Extracellular UDP-glucose can activate the purinergic P2Y14 receptor. The aim of the present study was to examine the physiological importance of P2Y14 receptors in the vasculature. The data presented herein show that UDP-glucose causes contraction in mouse coronary and basilar arteries. The EC50 values and immunohistochemistry illustrated the strongest P2Y14 receptor expression in the basilar artery. In the presence of pertussis toxin, UDP-glucose inhibited contraction in coronary arteries and in the basilar artery it surprisingly caused relaxation. After organ culture of the coronary artery, the EC50 value decreased and an increased staining for the P2Y14 receptor was observed, showing receptor plasticity.
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11
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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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12
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De Mey JGR, Vanhoutte PM. End o' the line revisited: moving on from nitric oxide to CGRP. Life Sci 2014; 118:120-8. [PMID: 24747136 DOI: 10.1016/j.lfs.2014.04.012] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2013] [Revised: 04/04/2014] [Accepted: 04/05/2014] [Indexed: 12/24/2022]
Abstract
When endothelin-1(ET-1) was discovered it was hailed as the prototypical endothelium-derived contracting factor (EDCF). However, over the years little evidence emerged convincingly demonstrating that the peptide actually contributes to moment-to-moment changes in vascular tone elicited by endothelial cells. This has been attributed to the profound inhibitory effect of nitric oxide (NO) on both the production (by the endothelium) and the action (on vascular smooth muscle) of ET-1. Hence, the peptide is likely to initiate acute changes in vascular diameter only under extreme conditions of endothelial dysfunction when the NO bioavailability is considerably reduced if not absent. The present essay discusses whether or not this concept should be revised, in particular in view of the potent inhibitory effect exerted by calcitonin gene related peptide (CGRP) released from sensorimotor nerves on vasoconstrictor responses to ET-1.
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Affiliation(s)
- Jo G R De Mey
- Institute of Molecular Medicine, University of South Denmark, Odense, Denmark; Cardiovascular Research Institute Maastricht, Maastricht, the Netherlands
| | - Paul M Vanhoutte
- Institute of Molecular Medicine, University of South Denmark, Odense, Denmark; Department of Pharmacology and Pharmacy and State Key Laboratory for Pharmaceutical Biotechnology, University of Hong Kong, Hong Kong, China.
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Minimally modified LDL upregulates endothelin type A receptors in rat coronary arterial smooth muscle cells. Mediators Inflamm 2013; 2013:656570. [PMID: 23861561 PMCID: PMC3703896 DOI: 10.1155/2013/656570] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2013] [Accepted: 05/26/2013] [Indexed: 12/21/2022] Open
Abstract
Minimally modified low-density lipoprotein (mmLDL) is a risk factor for cardiovascular disease. The present study investigated the effects of mmLDL on the expression of endothelin type A (ETA) receptors in coronary arteries. Rat coronary arteries were organ-cultured for 24 h. The contractile responses were recorded using a myographic system. ETA receptor mRNA and protein expressions were determined using real-time PCR and western blotting, respectively. The results showed that organ-culturing in the presence of mmLDL enhanced the arterial contractility mediated by the ETA receptor in a concentration-dependent and time-dependent manner. Culturing with mmLDL (10 μg/mL) for 24 h shifted the concentration-contractile curves toward the left significantly with increased Emax of 228% ± 20% from control of 100% ± 10% and significantly increased ETA receptor mRNA and protein levels. Inhibition of the protein kinase C, extracellular signal-related kinases 1 and 2 (ERK1/2), or NF-κB activities significantly attenuated the effects of mmLDL. The c-Jun N-terminal kinase inhibitor or the p38 pathway inhibitor, however, had no such effects. The results indicate that mmLDL upregulates the ETA receptors in rat coronary arterial smooth muscle cells mainly via activating protein kinase C, ERK1/2, and the downstream transcriptional factor, NF-κB.
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14
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Ahnstedt H, Cao L, Krause DN, Warfvinge K, Säveland H, Nilsson OG, Edvinsson L. Male-female differences in upregulation of vasoconstrictor responses in human cerebral arteries. PLoS One 2013; 8:e62698. [PMID: 23658641 PMCID: PMC3639206 DOI: 10.1371/journal.pone.0062698] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2013] [Accepted: 03/25/2013] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND AND PURPOSE Male-female differences may significantly impact stroke prevention and treatment in men and women, however underlying mechanisms for sexual dimorphism in stroke are not understood. We previously found in males that cerebral ischemia upregulates contractile receptors in cerebral arteries, which is associated with lower blood flow. The present study investigates if cerebral arteries from men and women differ in cerebrovascular receptor upregulation. EXPERIMENTAL APPROACH Freshly obtained human cerebral arteries were placed in organ culture, an established model for studying receptor upregulation. 5-hydroxtryptamine type 1B (5-HT1B), angiotensin II type 1 (AT1) and endothelin-1 type A and B (ETA and ETB) receptors were evaluated using wire myograph for contractile responses, real-time PCR for mRNA and immunohistochemistry for receptor expression. KEY RESULTS Vascular sensitivity to angiotensin II and endothelin-1 was markedly lower in cultured cerebral arteries from women as compared to men. ETB receptor-mediated contraction occurred in male but not female arteries. Interestingly, there were similar upregulation in mRNA and expression of 5-HT1B, AT1, and ETB receptors and in local expression of Ang II after organ culture. CONCLUSIONS AND IMPLICATIONS In spite of receptor upregulation after organ culture in both sexes, cerebral arteries from women were significantly less responsive to vasoconstrictors angiotensin II and endothelin-1 as compared to arteries from men. This suggests receptor coupling and/or signal transduction mechanisms involved in cerebrovascular contractility may be suppressed in females. This is the first study to demonstrate sex differences in the vascular function of human brain arteries.
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Affiliation(s)
- Hilda Ahnstedt
- Division of Experimental Vascular Research, Department of Clinical Sciences, Lund University, Lund, Sweden.
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15
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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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16
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Rapid functional upregulation of vasocontractile endothelin ETB receptors in rat coronary arteries. Life Sci 2012; 91:593-9. [DOI: 10.1016/j.lfs.2012.02.009] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2011] [Revised: 02/01/2012] [Accepted: 02/10/2012] [Indexed: 11/23/2022]
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17
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Expressional changes in cerebrovascular receptors after experimental transient forebrain ischemia. PLoS One 2012; 7:e41852. [PMID: 22848635 PMCID: PMC3407123 DOI: 10.1371/journal.pone.0041852] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2012] [Accepted: 06/29/2012] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Global ischemic stroke is one of the most prominent consequences of cardiac arrest, since the diminished blood flow to the brain results in cell damage and sometimes permanently impaired neurological function. The post-arrest period is often characterised by cerebral hypoperfusion due to subacute hemodynamic disturbances, the pathophysiology of which are poorly understood. In two other types of stroke, focal ischemic stroke and subarachnoid hemorrhage, it has earlier been demonstrated that the expression of certain vasoconstrictor receptors is increased in cerebral arteries several days after the insult, a phenomenon that leads to increased contraction of cerebral arteries, reduced perfusion of the affected area and worsened ischemic damage. Based on these findings, the aim of the present study was to investigate if transient global cerebral ischemia is associated with upregulation of vasoconstrictive endothelin and 5-hydroxytryptamine receptors in cerebral arteries. Experimental transient forebrain ischemia of varying durations was induced in male wistar rats, followed by reperfusion for 48 hours. Neurological function was assessed daily by three different tests and cerebrovascular expression and contractile function of endothelin and 5-hydroxytryptamine receptors were evaluated by wire myography, immunohistochemistry and western blotting. RESULTS Transient forebrain ischemia induced neurological deficits as well as functional upregulation of vasoconstrictive ET(B) and 5-HT(1B) receptors in cerebral arteries supplying mid- and forebrain regions. No receptor upregulation was seen in arteries supplying the hindbrain. Immunohistochemical stainings and western blotting demonstrated expressional upregulation of these receptor subtypes in the mid- and forebrain arteries and confirmed that the receptors were located in the smooth muscle layer of the cerebral arteries. CONCLUSIONS This study reveals a new pathophysiological aspect of global ischemic stroke, namely expressional upregulation of vasoconstrictor receptors in cerebral arteries two days after the insult, which might contribute to cerebral hypoperfusion and delayed neuronal damage after cardiac arrest.
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Kaundal RK, Deshpande TA, Gulati A, Sharma SS. Targeting endothelin receptors for pharmacotherapy of ischemic stroke: current scenario and future perspectives. Drug Discov Today 2012; 17:793-804. [DOI: 10.1016/j.drudis.2012.02.017] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2011] [Revised: 01/01/2012] [Accepted: 02/18/2012] [Indexed: 01/05/2023]
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19
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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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20
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Povlsen GK, Waldsee R, Ahnstedt H, Kristiansen KA, Johansen FF, Edvinsson L. In vivo experimental stroke and in vitro organ culture induce similar changes in vasoconstrictor receptors and intracellular calcium handling in rat cerebral arteries. Exp Brain Res 2012; 219:507-20. [PMID: 22585122 DOI: 10.1007/s00221-012-3108-6] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2012] [Accepted: 04/25/2012] [Indexed: 12/11/2022]
Abstract
Cerebral arteries subjected to different types of experimental stroke upregulate their expression of certain G-protein-coupled vasoconstrictor receptors, a phenomenon that worsens the ischemic brain damage. Upregulation of contractile endothelin B (ET(B)) and 5-hydroxytryptamine 1B (5-HT(1B)) receptors has been demonstrated after subarachnoid hemorrhage and global ischemic stroke, but the situation is less clear after focal ischemic stroke. Changes in smooth muscle calcium handling have been implicated in different vascular diseases but have not hitherto been investigated in cerebral arteries after stroke. Here, we evaluate changes of ET(B) and 5-HT(1B) receptors, intracellular calcium levels, and calcium channel expression in rat middle cerebral artery (MCA) after focal cerebral ischemia and in vitro organ culture, a proposed model of vasoconstrictor receptor changes after stroke. Rats were subjected to 2 h MCA occlusion followed by reperfusion for 1 or 24 h. Alternatively, MCAs from naïve rats were cultured for 1 or 24 h. ET(B) and 5-HT(1B) receptor-mediated contractions were evaluated by wire myography. Receptor and channel expressions were measured by real-time PCR and immunohistochemistry. Intracellular calcium was measured by FURA-2. Expression and contractile functions of ET(B) and 5-HT(1B) receptors were strongly upregulated and slightly downregulated, respectively, 24 h after experimental stroke or organ culture. ET(B) receptor-mediated contraction was mediated by calcium from intracellular and extracellular sources, whereas 5-HT(1B) receptor-mediated contraction was solely dependent on extracellular calcium. Organ culture and stroke increased basal intracellular calcium levels in MCA smooth muscle cells and decreased the expression of inositol triphosphate receptor and transient receptor potential canonical calcium channels, but not voltage-operated calcium channels.
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MESH Headings
- Animals
- Calcium/metabolism
- Cerebral Arteries/drug effects
- Cerebral Arteries/metabolism
- Disease Models, Animal
- Dose-Response Relationship, Drug
- Intracellular Fluid/drug effects
- Intracellular Fluid/metabolism
- Male
- Muscle, Smooth, Vascular/drug effects
- Muscle, Smooth, Vascular/metabolism
- Organ Culture Techniques
- Rats
- Rats, Wistar
- Receptor, Endothelin B/biosynthesis
- Receptor, Serotonin, 5-HT1B/biosynthesis
- Stroke/metabolism
- Vasoconstriction/drug effects
- Vasoconstriction/physiology
- Viper Venoms/pharmacology
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Affiliation(s)
- Gro Klitgaard Povlsen
- Department of Clinical Experimental Research, Glostrup Research Institute, Ndr. Ringvej 69, 2600, Glostrup, Denmark.
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21
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Minimally modified LDL upregulates endothelin type B receptors in rat coronary artery via ERK1/2 MAPK and NF-κB pathways. Biochim Biophys Acta Mol Cell Biol Lipids 2012; 1821:582-9. [DOI: 10.1016/j.bbalip.2011.12.001] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2011] [Revised: 11/22/2011] [Accepted: 12/08/2011] [Indexed: 01/08/2023]
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22
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Mazzuca MQ, Khalil RA. Vascular endothelin receptor type B: structure, function and dysregulation in vascular disease. Biochem Pharmacol 2012; 84:147-62. [PMID: 22484314 DOI: 10.1016/j.bcp.2012.03.020] [Citation(s) in RCA: 109] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2012] [Revised: 03/19/2012] [Accepted: 03/22/2012] [Indexed: 12/21/2022]
Abstract
Endothelin-1 (ET-1) is a major regulator of vascular function, acting via both endothelin receptor type A (ET(A)R) and type B (ET(B)R). Although the role of ET(A)R in vascular smooth muscle (VSM) contraction has been studied, little is known about ET(B)R. ET(B)R is a G-protein coupled receptor with a molecular mass of ~50 kDa and 442 amino acids arranged in seven transmembrane domains. Alternative splice variants of ET(B)R and heterodimerization and cross-talk with ET(A)R may affect the receptor function. ET(B)R has been identified in numerous blood vessels with substantial effects in the systemic, renal, pulmonary, coronary and cerebral circulation. ET(B)R in the endothelium mediates the release of relaxing factors such as nitric oxide, prostacyclin and endothelium-derived hyperpolarizing factor, and could also play a role in ET-1 clearance. ET(B)R in VSM mediates increases in [Ca(2+)](i), protein kinase C, mitogen-activated protein kinase and other pathways of VSM contraction and cell growth. ET-1/ET(A)R signaling has been associated with salt-sensitive hypertension (HTN) and pulmonary arterial hypertension (PAH), and ET(A)R antagonists have shown some benefits in these conditions. In search for other pathogenetic factors and more effective approaches, the role of alterations in endothelial ET(B)R and VSM ET(B)R in vascular dysfunction, and the potential benefits of modulators of ET(B)R in treatment of HTN and PAH are being examined. Combined ET(A)R/ET(B)R antagonists could be more efficacious in the management of conditions involving upregulation of ET(A)R and ET(B)R in VSM. Combined ET(A)R antagonist with ET(B)R agonist may need to be evaluated in conditions associated with decreased endothelial ET(B)R expression/activity.
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Affiliation(s)
- Marc Q Mazzuca
- Vascular Surgery Research Laboratory, Division of Vascular and Endovascular Surgery, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA
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23
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Li J, Cao YX, Liu Y, Xu CB. Minimally modified LDL upregulates endothelin type B receptors in rat basilar artery. Microvasc Res 2012; 83:178-84. [DOI: 10.1016/j.mvr.2011.12.001] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2011] [Revised: 11/22/2011] [Accepted: 12/08/2011] [Indexed: 11/29/2022]
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24
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Coucha M, Li W, Ergul A. The effect of endothelin receptor A antagonism on basilar artery endothelium-dependent relaxation after ischemic stroke. Life Sci 2012; 91:676-80. [PMID: 22365958 DOI: 10.1016/j.lfs.2012.01.020] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2011] [Revised: 12/27/2011] [Accepted: 01/26/2012] [Indexed: 01/01/2023]
Abstract
AIMS Endothelin (ET) receptor A antagonism decreases neuronal damage in experimental models of stroke. Since large arteries like basilar artery contribute significantly to total cerebrovascular resistance and are major determinants of microvascular pressure, dysregulation of basilar artery function may worsen stroke injury. ET-1 is involved in the regulation of basilar constriction. However, whether stroke influences vasoreactivity of basilar artery and to what extent ET-1 contributes to basilar vascular dysfunction after stroke remained unknown. The goal of this study was to test the hypothesis that ET-1 impairs basilar artery vasorelaxation after ischemia/reperfusion (I/R) injury via activation of ET(A) receptor. MAIN METHODS Male Wistar rats were subjected to 3h middle cerebral artery occlusion (MCAO) and 21 h reperfusion. One group received ET(A) receptor antagonist atrasentan (5 mg/kg, i.p.) at reperfusion. At 24h, basilar arteries were isolated from control non-stroked, stroked and stroked+atrasentan-treated animals for vascular reactivity measurements using pressurized arteriograph. KEY FINDINGS Acetylcholine (Ach)-induced maximum relaxation (R(max)) was decreased in stroked animals as compared to non-stroked group and ET(A) antagonism partially restored it. There was also a trend for decreased EC(50) value for the antagonist treatment group indicating improved Ach sensitivity. SIGNIFICANCE These findings suggest that I/R not only affects vessels distal to the occlusion but also impairs relaxation of proximal large vessels. ET-1-mediated basilar artery dysfunction may contribute to neurovascular damage after stroke and early restoration of vascular function by ET receptor antagonism after I/R injury may offer a therapeutic strategy.
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Affiliation(s)
- Maha Coucha
- Department of Physiology, Georgia Health Sciences University, Augusta, GA 30912, United States
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25
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Cao L, Xu CB, Zhang Y, Cao YX, Edvinsson L. Secondhand smoke exposure induces Raf/ERK/MAPK-mediated upregulation of cerebrovascular endothelin ETA receptors. BMC Neurosci 2011; 12:109. [PMID: 22044770 PMCID: PMC3219602 DOI: 10.1186/1471-2202-12-109] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2011] [Accepted: 11/01/2011] [Indexed: 02/02/2023] Open
Abstract
BACKGROUND Cigarette smoking enhances the risk of stroke. However, the underlying molecular mechanisms are largely unknown. The present study established an in vivo rat secondhand cigarette smoking (SHS) model and examined the hypothesis that SHS upregulates endothelin receptors with increased cerebrovascular contraction via the Raf/extracellular signal-regulated kinase (ERK)/mitogen-activated protein kinases (MAPK) pathway. RESULTS Rats were exposed to SHS for up to 8 weeks. The cerebral artery vasoconstriction was recorded by a sensitive myograph. The mRNA and protein expressions for endothelin receptors in cerebral arteries were studied by real-time PCR and Western blot. Compared to fresh air exposed rats, cerebral arteries from SHS rats exhibited stronger contractile responses (P < 0.05) mediated by endothelin type A (ETA) receptors. The expressions of mRNA and protein for ETA receptors in the cerebral arteries from SHS rats were higher (P < 0.05) than that in control. SHS did not affect endothelin type B (ETB) receptor-mediated contractions, mRNA or protein levels. The results suggest that SHS upregulates ETA, but not ETB receptors in vivo. After SHS exposure, the mRNA levels of Raf-1 and ERK1/2, the protein expression of phosphorylated (p)-Raf-1 and p-ERK1/2 were increased (P < 0.05). Raf-1 inhibitor, GW5074 suppressed the enhanced ETA receptor-mediated contraction, mRNA and protein levels induced by SHS. In addition, GW5074 inhibited the SHS-caused increased mRNA and phosphorylated protein levels of Raf-1 and ERK1/2, suggesting that SHS induces activation of the Raf/ERK/MAPK pathway. CONCLUSIONS SHS upregulates cerebrovascular ETA receptors via the Raf/ERK/MAPK pathway, which provides novel understanding of mechanisms involved in SHS-associated stroke.
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Affiliation(s)
- Lei Cao
- Division of Experimental Vascular Research, Institute of Clinical Science in Lund, Lund University, Sweden
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26
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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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28
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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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29
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Sandhu H, Xu CB, Edvinsson L. Alteration in contractile G-protein coupled receptor expression by moist snuff and nicotine in rat cerebral arteries. Toxicol Appl Pharmacol 2011; 252:138-49. [PMID: 21316381 DOI: 10.1016/j.taap.2011.01.016] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2010] [Revised: 12/22/2010] [Accepted: 01/25/2011] [Indexed: 10/18/2022]
Abstract
The cardiovascular risk for users of use of Swedish snus/American snuff (moist tobacco) has been debated for a long time. The present study was designed to examine the effects of water- or lipid-soluble (DMSO-soluble) snus and nicotine, the most important substance in tobacco, on the expression of vasocontractile G-protein coupled receptors (GPCR), such as endothelin ET(B), serotonin 5-HT(1B), and thromboxane A(2) TP receptors, in rat cerebral arteries. Studies show that these vasocontractile GPCR show alterations by lipid-soluble cigarette smoke particles via activation of mitogen-activated protein kinases (MAPK). However, the effects of moist tobacco on the expression of GPCR are less studied. Rat middle cerebral arteries were isolated and organ cultured in serum-free medium for 24h in the presence of water-soluble snus (WSS), DMSO-soluble snus (DSS), or nicotine. The dose of snus and nicotine was kept at plasma level of snus users (25ng nicotine/ml). A high dose (250ng nicotine/ml) was also included due to the previous results showing alteration in the GPCR expression by nicotine at this concentration. Contractile responses to the ET(B) receptor agonist sarafotoxin 6c, 5-HT(1B) receptor agonist 5-carboxamidotryptamine, and TP receptor agonist U46619 were investigated by a sensitive myograph. The expression of ET(B), 5-HT(1B), and TP receptors was studied at mRNA and protein levels using quantitative real-time PCR and immunohistochemistry, respectively. Organ culture with WSS or DSS (25ng nicotine/ml) lowered the 5-HT(1B) receptor-mediated contraction. Furthermore, DSS shifted the TP receptor-mediated contraction curve left-wards with a stronger contraction. High dose of nicotine (250ng nicotine/ml) increased the ET(B) receptor-mediated contraction. The combined 5-HT(1B) and 5-HT(2A) receptor-mediated contraction was increased, and both the 5-CT and TxA2 induced contractions were left-ward shifted by WSS, DSS, or nicotine (250ng nicotine/ml). Only the DSS group showed that the increase of 5-HT(1B) receptor-mediated contraction occurred at the transcriptional level, demonstrated by an increased mRNA expression for the receptor. Thus, snus and nicotine alter the GPCR expression in the cerebral arteries, which may be involved in cerebral vascular disease.
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Affiliation(s)
- Hardip Sandhu
- Department of Clinical Experimental Research, Glostrup Research Institute, Ndr. Ringvej 69, 2600 Glostrup, Denmark.
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30
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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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Kelly-Cobbs AI, Harris AK, Elgebaly MM, Li W, Sachidanandam K, Portik-Dobos V, Johnson M, Ergul A. Endothelial endothelin B receptor-mediated prevention of cerebrovascular remodeling is attenuated in diabetes because of up-regulation of smooth muscle endothelin receptors. J Pharmacol Exp Ther 2010; 337:9-15. [PMID: 21205912 DOI: 10.1124/jpet.110.175380] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Structure and function of the cerebrovasculature is critical for ischemic stroke outcome. We showed that diabetes causes cerebrovascular remodeling by activation of the endothelin A (ET(A)) receptors. The goal of this study was to test the hypotheses that vasculoprotective endothelial ET(B) receptors are decreased and pharmacological inhibition of the ET(B) receptor augments vascular remodeling of middle cerebral arteries (MCAs) in type 2 diabetes. MCA structure, matrix metalloprotease (MMP) activity, and matrix proteins as well as ET(A) and ET(B) receptor profiles were assessed in control Wistar and diabetic Goto-Kakizaki rats treated with vehicle, the ET(B) receptor antagonist (2R,3R,4S)-4-(1,3-benzodioxol-5-yl)-1-[2-[(2,6-diethylphenyl)amino]-2-oxoethyl]-2-(4-propoxyphenyl)pyrrolidine-3-carboxylic acid (A192621) (30 mg/kg/day), or the dual ET receptor antagonist bosentan (100 mg/kg/day) for 4 weeks. Diabetes increased vascular smooth muscle (VSM) ET(A) and ET(B) receptors; the increase was prevented by chronic bosentan treatment. MCA wall thickness was increased in diabetes, and this was associated with increased MMP-2 activity and collagen deposition but reduced MMP-13 activity. Because of up-regulation of VSM ET receptors in diabetes, selective ET(B) receptor antagonism with A192621 blunts this response, and combined ET(A) and ET(B) receptor blockade with bosentan completely prevents this response. On the other hand, A192621 treatment augmented remodeling in control animals, indicating a physiological protective role for this receptor subtype. Attenuation of changes in ET receptor profile with bosentan treatment suggests that ET-1 has a positive feedback on the expression of its receptors in the cerebrovasculature. These results emphasize that ET receptor antagonism may yield different results in healthy and diseased states.
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Affiliation(s)
- Aisha I Kelly-Cobbs
- Department of Physiology, Medical College of Georgia, Augusta, GA 30912, USA
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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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Waldsee R, Ahnstedt H, Eftekhari S, Edvinsson L. Involvement of calcium-calmodulin-dependent protein kinase II in endothelin receptor expression in rat cerebral arteries. Am J Physiol Heart Circ Physiol 2009; 298:H823-32. [PMID: 20008273 DOI: 10.1152/ajpheart.00759.2009] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Experimental cerebral ischemia and organ culture of cerebral arteries result in the enhanced expression of endothelin ET(B) receptors in smooth muscle cells via increased transcription. The present study was designed to evaluate the involvement of calcium-calmodulin-dependent protein kinase (CAMK) in the transcriptional expression of endothelin receptors after organ culture. Rat basilar arteries were incubated for 24 h with or without the CAMK inhibitor KN93 or ERK1/2 inhibitor U0126. The contractile responses to endothelin-1 (ET-1; ET(A) and ET(B) receptor agonist) and sarafotoxin 6c (S6c; ET(B) receptor agonist) were studied using a sensitive myograph. The mRNA levels of the ET(A) and ET(B) receptors and CAMKII were determined by real-time PCR, and their protein levels were evaluated by immunohistochemistry and Western blot. The mRNA levels of CAMKII and the ET(B) receptor increased during organ culture, but there was no change in the expression of the ET(A) receptor. This effect was abolished by coincubation with KN93 or U0126. In functional studies, both inhibitors attenuated the S6c-induced contraction. Incubating the arteries with KN93, but not U0126, decreased the amount of phosphorylated CAMKII. The inhibitors had no effect on the levels of myosin light chain during organ culture, as measured by Western blot. CAMKII is involved in the upregulation of the endothelin ET(B) receptor and interacts with the ERK1/2 pathway to enhance receptor expression. CAMKII has no effect on the contractile apparatus in rat cerebral arteries.
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Affiliation(s)
- Roya Waldsee
- Department of Clinical Sciences, Lund University and Lund University Hospital, Sweden.
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Hein TW, Ren Y, Yuan Z, Xu W, Somvanshi S, Nagaoka T, Yoshida A, Kuo L. Functional and molecular characterization of the endothelin system in retinal arterioles. Invest Ophthalmol Vis Sci 2009; 50:3329-36. [PMID: 19151386 DOI: 10.1167/iovs.08-3129] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
PURPOSE Activation of the endothelin (ET) system has been implicated in the pathogenesis of retinal ischemic disease. Although ET-1, the predominant endogenous isoform of ET, has been shown to cause constriction of retinal vessels, the expression and functional significance of its synthesis and the involved specific ET receptors in retinal arterioles remain unknown. The authors examined the roles of ET(A) and ET(B) receptors and of endothelin-converting enzyme (ECE)-1 in ET-1-induced vasomotor responses of single retinal arterioles. METHODS To exclude systemic confounding effects, porcine retinal arterioles were isolated for vasoreactivity and molecular studies. RESULTS Isolated and pressurized retinal arterioles developed basal tone and constricted in a manner dependent on concentration to ET-1. ET-1 precursor big ET-1 elicited time-dependent vasoconstriction over 20 minutes, which was blocked by the ECE-1 inhibitor phosphoramidon. ET(A) receptor antagonist BQ123 inhibited most (approximately 90%) of vasoconstrictions to ET-1 and big ET-1. ET(B) receptor agonist sarafotoxin also elicited concentration-dependent constriction of retinal arterioles but with significantly less potency than ET-1. ET(B) receptor antagonist BQ788 abolished vasoconstriction to sarafotoxin but only slightly reduced responses to ET-1 and big ET-1. Protein and mRNA expressions of ET(A), ET(B), and ECE-1 were detected in retinal arterioles. Immunohistochemistry revealed ET(A) and ET(B) receptors predominantly in smooth muscle and ECE-1 predominantly in endothelium and smooth muscle. CONCLUSIONS ET-1 elicits constriction of retinal arterioles predominantly through the activation of smooth muscle ET(A) receptors. Endogenous production of ET-1 from vascular ECE-1 is sufficient to evoke ET(A) receptor-dependent constriction in retinal arterioles.
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Affiliation(s)
- Travis W Hein
- Department of Ophthalmology, Scott and White Eye Institute, Temple, Texas 76504, USA.
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Nilsson D, Gustafsson L, Wackenfors A, Gesslein B, Edvinsson L, Paulsson P, Ingemansson R, Malmsjö M. Up-regulation of endothelin type B receptors in the human internal mammary artery in culture is dependent on protein kinase C and mitogen-activated kinase signaling pathways. BMC Cardiovasc Disord 2008; 8:21. [PMID: 18778461 PMCID: PMC2553399 DOI: 10.1186/1471-2261-8-21] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2008] [Accepted: 09/08/2008] [Indexed: 11/24/2022] Open
Abstract
Background Up-regulation of vascular endothelin type B (ETB) receptors is implicated in the pathogenesis of cardiovascular disease. Culture of intact arteries has been shown to induce similar receptor alterations and has therefore been suggested as a suitable method for, ex vivo, in detail delineation of the regulation of endothelin receptors. We hypothesize that mitogen-activated kinases (MAPK) and protein kinase C (PKC) are involved in the regulation of endothelin ETB receptors in human internal mammary arteries. Methods Human internal mammary arteries were obtained during coronary artery bypass graft surgery and were studied before and after 24 hours of organ culture, using in vitro pharmacology, real time PCR and Western blot techniques. Sarafotoxin 6c and endothelin-1 were used to examine the endothelin ETA and ETB receptor effects, respectively. The involvement of PKC and MAPK in the endothelin receptor regulation was examined by culture in the presence of antagonists. Results The endohtelin-1-induced contraction (after endothelin ETB receptor desensitization) and the endothelin ETA receptor mRNA expression levels were not altered by culture. The sarafotoxin 6c contraction, endothelin ETB receptor protein and mRNA expression levels were increased after organ culture. This increase was antagonized by; (1) PKC inhibitors (10 μM bisindolylmaleimide I and 10 μM Ro-32-0432), and (2) inhibitors of the p38, extracellular signal related kinases 1 and 2 (ERK1/2) and C-jun terminal kinase (JNK) MAPK pathways (10 μM SB203580, 10 μM PD98059 and 10 μM SP600125, respectively). Conclusion In conclusion, PKC and MAPK seem to be involved in the up-regulation of endothelin ETB receptor expression in human internal mammary arteries. Inhibiting these intracellular signal transduction pathways may provide a future therapeutic target for hindering the development of vascular endothelin ETB receptor changes in cardiovascular disease.
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Affiliation(s)
- David Nilsson
- Department of Medicine, Lund University Hospital, Sweden.
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Liu J, Zhao M, Cui G, Zhang X, Wang J, Peng S. Methyl (11aS)-1,2,3,5,11,11a-hexahydro-3,3-dimethyl-1-oxo-6H-imidazo-[3',4':1,2]pyridin[3,4-b]indol-2-substituted acetates: synthesis and three-dimensional quantitative structure-activity relationship investigation as a class of novel vasodilators. J Med Chem 2008; 51:4715-23. [PMID: 18616237 DOI: 10.1021/jm800249j] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
To find selective inhibitor of phosphodiesterase type 5 (PDE5), the essential structure elements of clinically used drugs sildenafil, vardenafil, and tadalafil were combined and a tetracyclic parent was constructed to which in 2-positions substituted acetic acid methylesters were introduced to form 17 novel vasodilators, methyl (11aS)-1,2,3,5,11,11a-hexahydro-3,3-dimethyl-1-oxo-6H-imidazo[3',4':1,2]- pyridin[3,4-b]indol-2-substituted acetates. By molecular field analysis (MFA), an equation of three-dimensional quantitative structure-activity relationship (3D QSAR) was established, which not only revealed the dependence of the in vitro vasorelaxation activities on the structures but also pointed out the way to design new lead compounds properly. Docking these novel vasodilators into the hydrophobic pocket of phosphodiesterase type 5 (PDE5) revealed that their adaptabilities to this pocket did significantly affect on their vasorelaxation activity. Actually, the docking adaptabilities of these novel vasodilators to PDE5 were consistent with the conformational requirements of them to MFA and with the crystal conformation of two representatives.
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Affiliation(s)
- Jiawang Liu
- College of Pharmaceutical Sciences, Capital Medical UniVersity, Beijing 100069, PR China
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Johnsson E, Maddahi A, Wackenfors A, Edvinsson L. Enhanced expression of contractile endothelin ETB receptors in rat coronary artery after organ culture. Eur J Pharmacol 2008; 582:94-101. [DOI: 10.1016/j.ejphar.2007.12.030] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2007] [Revised: 10/28/2007] [Accepted: 12/16/2007] [Indexed: 10/24/2022]
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Nilsson D, Wackenfors A, Gustafsson L, Ugander M, Ingemansson R, Edvinsson L, Malmsjö M. PKC and MAPK signalling pathways regulate vascular endothelin receptor expression. Eur J Pharmacol 2008; 580:190-200. [DOI: 10.1016/j.ejphar.2007.10.071] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2007] [Revised: 10/12/2007] [Accepted: 10/18/2007] [Indexed: 01/24/2023]
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Endothelin receptor-mediated vasodilatation: Effects of organ culture. Eur J Pharmacol 2008; 579:233-40. [DOI: 10.1016/j.ejphar.2007.09.031] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2007] [Revised: 08/08/2007] [Accepted: 09/25/2007] [Indexed: 11/18/2022]
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Vikman P, Edvinsson L. Gene expression profiling in the human middle cerebral artery after cerebral ischemia. Eur J Neurol 2007; 13:1324-32. [PMID: 17116215 DOI: 10.1111/j.1468-1331.2006.01496.x] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
We have investigated the gene expression in human middle cerebral artery (MCA) after ischemia. Ischemic stroke affects the perfusion in the affected area and experimental cerebral ischemia results in upregulation of vasopressor receptors in the MCA leading to the ischemic area. We obtained human MCA samples distributing to the ischemic area, 7-10 days post-stroke. The gene expression was examined with real-time polymerase chain reaction (PCR) and microarray, proteins were studied with immunohistochemistry. We investigated genes previously shown to be upregulated in animal models of cerebral ischemia (e.g. ET(A), ET(B), AT1, AT2, and 5-HT(2A/1B/1D)). Their mRNA expression was increased compared with controls, consistent with findings in experimental stroke. Immunohistochemistry showed upregulation of the receptors localized on the smooth muscle cells. The gene expression was profiled with microarray and seven genes chosen for further investigation with real-time PCR; ELK3, LY64, Metallothionin IG, POU3F4, Actin alpha2, RhoA and smoothelin. Six of these were regulated the same way when confirming array expression with real-time PCR. Gene expression studies in the human MCA leading to the ischemic region is similar to that seen after MCA occlusion in rats. We found new genes that support the dynamic changes that occur in the MCA distributing to the ischemic region.
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Affiliation(s)
- P Vikman
- Department of Experimental Vascular Research, Institution of Medicine, Lund University, Lund, Sweden.
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Henriksson M, Stenman E, Vikman P, Edvinsson L. Protein kinase C inhibition attenuates vascular ETB receptor upregulation and decreases brain damage after cerebral ischemia in rat. BMC Neurosci 2007; 8:7. [PMID: 17212812 PMCID: PMC1770924 DOI: 10.1186/1471-2202-8-7] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2006] [Accepted: 01/09/2007] [Indexed: 11/10/2022] Open
Abstract
Background Protein kinase C (PKC) is known to be involved in the pathophysiology of experimental cerebral ischemia. We have previously shown that after transient middle cerebral artery occlusion, there is an upregulation of endothelin receptors in the ipsilateral middle cerebral artery. The present study aimed to examine the effect of the PKC inhibitor Ro-32-0432 on endothelin receptor upregulation, infarct volume and neurology outcome after middle cerebral artery occlusion in rat. Results At 24 hours after transient middle cerebral artery occlusion (MCAO), the contractile endothelin B receptor mediated response and the endothelin B receptor protein expression were upregulated in the ipsilateral but not the contralateral middle cerebral artery. In Ro-32-0432 treated rats, the upregulated endothelin receptor response was attenuated. Furthermore, Ro-32-0432 treatment decreased the ischemic brain damage significantly and improved neurological scores. Immunohistochemistry showed fainter staining of endothelin B receptor protein in the smooth muscle cells of the ipsilateral middle cerebral artery of Ro-32-0432 treated rats compared to control. Conclusion The results suggest that treatment with Ro-32-0432 in ischemic stroke decreases the ischemic infarction area, neurological symptoms and associated endothelin B receptor upregulation. This provides a new perspective on possible mechanisms of actions of PKC inhibition in cerebral ischemia.
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Affiliation(s)
- Marie Henriksson
- Division of Experimental Vascular Research, Department of Clinical Sciences in Lund, Lund University, Sweden
| | - Emelie Stenman
- Division of Experimental Vascular Research, Department of Clinical Sciences in Lund, Lund University, Sweden
| | - Petter Vikman
- Division of Experimental Vascular Research, Department of Clinical Sciences in Lund, Lund University, Sweden
| | - Lars Edvinsson
- Division of Experimental Vascular Research, Department of Clinical Sciences in Lund, Lund University, Sweden
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Beg SS, Hansen-Schwartz JA, Vikman PJ, Xu CB, Edvinsson LI. Protein kinase C inhibition prevents upregulation of vascular ET(B) and 5-HT(1B) receptors and reverses cerebral blood flow reduction after subarachnoid haemorrhage in rats. J Cereb Blood Flow Metab 2007; 27:21-32. [PMID: 16736053 DOI: 10.1038/sj.jcbfm.9600313] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The pathogenesis of cerebral ischaemia after subarachnoid haemorrhage (SAH) still remains elusive. The purpose of the present study was to examine whether specific protein kinas C (PKC) inhibition in rats could alter the transcriptional SAH induced Endothelin (ET) type B and 5-hydroxytryptamine type 1B (5-HT(1B)) receptor upregulation and prevent the associated cerebral blood flow (CBF) reduction. The PKC inhibitor RO-31-7549 or vehicle was injected intracisternally after the induced SAH in rats (n=3 to 10 in each groups for each method). The involvement of the PKC isoforms was investigated with Western blot; only PKCdelta and PKCalpha subtypes were increased after SAH RO-31-7549 treatment abolished this. At 2 days after the SAH basilar and middle cerebral arteries were harvested and the contractile response to endothelin-1 (ET-1; ET(A) and ET(B) receptor agonist) and 5-carboxamidotryptamine (5-CT; 5-HT(1) receptor agonist) were investigated with a myograph. The contractile responses to ET-1 and 5-CT were increased (P<0.05) after SAH compared with sham operated rats. In parallel, the ET(B) and 5-HT(1B) receptor mRNA and protein expression were significantly elevated after SAH, as analysed by quantitative real-time polymerase chain reaction and immunohistochemistry, respectively. Administration of RO-31-7549 prevented the upregulated contraction elicited by application of ET-1 and 5-CT in cerebral arteries and kept the ET(B) and 5-HT(1B) receptor mRNA and protein levels at pre-SAH levels. Regional and global CBF evaluated by an autoradiographic technique were reduced by 60%+/-4% after SAH (P<0.05) and prevented by treatment with RO-31-7549. Our study suggests that PKC plays an important role in the pathogenesis of cerebral ischaemia after SAH.
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Affiliation(s)
- Saema S Beg
- Department of Clinical Sciences, Division of Experimental Vascular Research, Lund University Hospital, Lund, Sweden.
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Henriksson M, Vikman P, Stenman E, Beg S, Edvinsson L. Inhibition of PKC activity blocks the increase of ETB receptor expression in cerebral arteries. BMC Pharmacol 2006; 6:13. [PMID: 17129394 PMCID: PMC1698473 DOI: 10.1186/1471-2210-6-13] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2006] [Accepted: 11/28/2006] [Indexed: 11/10/2022] Open
Abstract
Background Previous studies have shown that there is a time-dependent upregulation of contractile endothelin B (ETB) receptors in middle cerebral arteries (MCA) after organ culture. This upregulation is dependent on mitogen-activated protein kinases and possibly protein kinase C (PKC). The aim of this study was to examine the effect of PKC inhibitors with different profiles on the upregulation of contractile ETB receptors in rat MCA. Artery segments were incubated for 24 hours at 37°C. To investigate involvement of PKC, inhibitors were added to the medium before incubation. The contractile endothelin-mediated responses were measured and real-time PCR was used to detect endothelin receptor mRNA levels. Furthermore, immunohistochemistry was used to demonstrate the ETB receptor protein distribution in the MCA and Western blot to measure which of the PKC subtypes that were affected by the inhibitors. Results The PKC inhibitors bisindolylmaleimide I, Ro-32-0432 and PKC inhibitor 20–28 attenuated the ETB receptor mediated contractions. Furthermore, Ro-32-0432 and bisindolylmaleimide I decreased ETB receptor mRNA levels while PKC inhibitor 20–28 reduced the amount of receptor protein on smooth muscle cells. PKC inhibitor 20–28 also decreased the protein levels of the five PKC subtypes studied (α, βI, γ, δ and ε). Conclusion The results show that PKC inhibitors are able to decrease the ETB receptor contraction and expression in MCA smooth muscle cells following organ culture. The PKC inhibitor 20–28 affects the protein levels, while Ro-32-0432 and bisindolylmaleimide I affect the mRNA levels, suggesting differences in activity profile. Since ETB receptor upregulation is seen in cerebral ischemia, the results of the present study provide a way to interfere with the vascular involvement in cerebral ischemia.
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Affiliation(s)
- Marie Henriksson
- Division of Experimental Vascular Research, Clinical Sciences, Lund University, Lund, Sweden
| | - Petter Vikman
- Division of Experimental Vascular Research, Clinical Sciences, Lund University, Lund, Sweden
| | - Emelie Stenman
- Division of Experimental Vascular Research, Clinical Sciences, Lund University, Lund, Sweden
| | - Saema Beg
- Division of Experimental Vascular Research, Clinical Sciences, Lund University, Lund, Sweden
| | - Lars Edvinsson
- Division of Experimental Vascular Research, Clinical Sciences, Lund University, Lund, Sweden
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Henriksson M, Stenman E, Vikman P, Edvinsson L. MEK1/2 inhibition attenuates vascular ETA and ETB receptor alterations after cerebral ischaemia. Exp Brain Res 2006; 178:470-6. [PMID: 17091294 DOI: 10.1007/s00221-006-0753-7] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2006] [Accepted: 10/06/2006] [Indexed: 11/26/2022]
Abstract
Cerebral ischaemia is associated with elevated levels of endothelin B (ETB) receptors in the ipsilateral middle cerebral artery (MCA). This up-regulation of ET receptors occurs via de novo transcription involving mitogen-activated protein kinases (MAPK). The aim of this study was to examine the effect of inhibition of the MAP kinase/ERK kinase (MEK)1/2 on ET receptor alteration, brain damage, and neurology in experimental cerebral ischaemia. Transient middle cerebral artery occlusion (MCAO) was induced in male Wistar rats by the intraluminal filament technique. The animals received 100 mg/kg intraperitoneally of the MEK1/2 inhibitor U0126 or vehicle in conjunction with the occlusion. After 24 h, the rats were decapitated and the brains removed. The middle cerebral arteries were dissected out and examined with myographs or immunohistochemistry. The ischaemic areas of the brains were compared. After the MCAO, the contractile responses of the ETA and ETB receptors were augmented in the ipsilateral MCA. U0126 decreased this alteration in ET receptor response. Furthermore, treatment with U0126 significantly decreased the brain damage and improved neurological scores. Immunohistochemistry showed that there were lower protein levels of phosphorylated extracellular signal-regulated kinases (ERK)1/2 and phosphorylated transcription factor Elk-1 in the U0126-treated rats compared to control. The results show that treatment with the MEK1/2 inhibitor U0126 in ischaemic stroke decreases brain damage, neurological symptoms, and ET receptor alteration. The vascular effects of U0126 provide new perspective on possible mechanisms of actions of MAPK inhibition in cerebral ischaemia.
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Affiliation(s)
- Marie Henriksson
- Division of Experimental Vascular Research, Department of Clinical Sciences in Lund, BMC A13, Lund University, Lund, 221 84 Sweden.
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Eskesen K, Edvinsson L. Upregulation of endothelin ETB receptor-mediated vasoconstriction in rat coronary artery after organ culture. Eur J Pharmacol 2006; 539:192-4. [PMID: 16725137 DOI: 10.1016/j.ejphar.2006.04.024] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2005] [Revised: 04/20/2006] [Accepted: 04/25/2006] [Indexed: 11/20/2022]
Abstract
The aim of this study was to examine if endothelin ET(B) receptor-mediated contraction occurred in isolated segments of rat coronary arteries during organ culture. Presence of contractile endothelin ET(B) receptors was studied by measuring the change in isometric tension in rings of left anterior descending coronary arteries isolated from hearts of rats as response to application of the selective endothelin ET(B) receptor agonist, Sarafotoxin 6c and endothelin-1. In segments cultured 1 day in serum free Dulbecco's Modified Eagle's Medium, Sarafotoxin 6c induced a concentration dependent contraction with a pEC(50) value of 10.4+/-0.21 and a maximal response of 3.9+/-0.25 mN/mm (n=15). The maximal contraction was significantly larger than the responses measured in fresh tissue, where the mean value of the maximal contractions was 0.22+/-0.03 mN/mm (n=17). The increased contraction to Sarafotoxin 6c after culturing could be eliminated with addition of the transcriptional blocker, actinomycin D, to the culture medium or be significantly attenuated by application of the translational inhibitor, cycloheximide. The vasoconstrictor effect of endothelin-1 or to depolarisation by high K(+)-solution was not modified after 1 day in culture medium. The experiments indicate that organ culture of rat coronary arteries upregulate endothelin ET(B) receptor-mediated contraction by inducing synthesis of new protein.
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Affiliation(s)
- Karen Eskesen
- Department of Clinical Experimental Research, University Hospital of Glostrup, Glostrup 2600, Denmark.
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Beg SAS, Hansen-Schwartz JA, Vikman PJ, Xu CB, Edvinsson LIH. ERK1/2 inhibition attenuates cerebral blood flow reduction and abolishes ET(B) and 5-HT(1B) receptor upregulation after subarachnoid hemorrhage in rat. J Cereb Blood Flow Metab 2006; 26:846-56. [PMID: 16251886 DOI: 10.1038/sj.jcbfm.9600236] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Upregulation of endothelin B (ET(B)) and 5-hydroxytryptamine 1B (5-HT(1B)) receptors via transcription has been found after experimental subarachnoid hemorrhage (SAH), and this is associated with enhanced phosphorylation of the mitogen-activated protein kinase (MAPK) extracellular signal-regulated kinase (ERK1/2). In the present study, we hypothesized that inhibition of ERK1/2 alters the ET(B) and 5-HT(1B) receptor upregulation and at the same time prevents the sustained cerebral blood flow (CBF) reduction associated with SAH. The ERK1/2 inhibitor SB386023-b was injected intracisternally in conjunction with and after the induced SAH in rats. At 2 days after the SAH, cerebral arteries were harvested for quantitative real-time polymerase chain reaction, immunohistochemistry and analysis of contractile responses to endothelin-1 (ET-1; ET(A) and ET(B) receptor agonist) and 5-carboxamidotryptamine (5-CT; 5-HT1 receptor agonist) in a sensitive myograph. To investigate if ERK1/2 inhibition had an influence on the local and global CBF after SAH, an autoradiographic technique was used. At 48 h after induced SAH, global and regional CBF were reduced by 50%. This reduction was prevented by treatment with SB386023-b. The ERK1/2 inhibition also decreased the maximum contraction elicited by application of ET-1 and 5-CT in cerebral arteries compared with SAH. In parallel, ERK1/2 inhibition downregulated ET(B) and 5-HT(1B) receptor messenger ribonucleic acid and protein levels compared with the SAH. Cerebral ischemia after SAH involves vasoconstriction and subsequent reduction in the CBF. The results suggest that ERK1/2 inhibition might be a potential treatment for the prevention of cerebral vasospasm and ischemia associated with SAH.
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MESH Headings
- Animals
- Autoradiography
- Brain/blood supply
- Brain/physiopathology
- Cerebral Arteries/drug effects
- Cerebral Arteries/physiology
- Cerebrovascular Circulation/drug effects
- Cerebrovascular Circulation/physiology
- Disease Models, Animal
- Endothelin-1/pharmacology
- Enzyme Inhibitors/pharmacology
- Extracellular Signal-Regulated MAP Kinases/antagonists & inhibitors
- Extracellular Signal-Regulated MAP Kinases/drug effects
- Extracellular Signal-Regulated MAP Kinases/metabolism
- Immunohistochemistry
- Male
- Muscle Contraction/drug effects
- Muscle Contraction/physiology
- Muscle, Smooth, Vascular/drug effects
- Muscle, Smooth, Vascular/metabolism
- RNA, Messenger/analysis
- Rats
- Rats, Sprague-Dawley
- Receptor, Endothelin B/metabolism
- Receptor, Serotonin, 5-HT1B/metabolism
- Regional Blood Flow
- Reverse Transcriptase Polymerase Chain Reaction
- Serotonin Receptor Agonists/pharmacology
- Subarachnoid Hemorrhage/metabolism
- Subarachnoid Hemorrhage/physiopathology
- Up-Regulation
- Vasoconstriction/drug effects
- Vasoconstriction/physiology
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Affiliation(s)
- Saema A S Beg
- Department of Clinical Sciences, Division of Experimental Vascular Research, Lund University Hospital, Lund, Sweden.
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Jamali R, Edvinsson L. Involvement of protein kinases on the upregulation of endothelin receptors in rat basilar and mesenteric arteries. Exp Biol Med (Maywood) 2006; 231:403-11. [PMID: 16565436 DOI: 10.1177/153537020623100406] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Endothelin(B) (ET(B)) receptors are upregulated in experimental stroke or after 24 hrs of organ culture. This upregulation is manifested both as stronger contraction and as an increase in ET(B) receptor messenger RNA (mRNA) levels. The present study was designed to evaluate the importance of protein kinases (c-Jun N-terminal kinase [JNK], protein kinase C [PKC], and extracellular signal-regulated kinase [ERK1/2]) in ET(B) receptor upregulation after organ culture. Rat basilar and mesenteric arteries were incubated for 24 hrs in Dulbecco's modified Eagle's medium (DMEM) with or without the PKC inhibitor, RO-31-7549; the ERK1/2 inhibitor, SB386023; or the JNK inhibitor, SP600125, added 3, 6, or 12 hrs after initiation of incubation. Subsequently, vessel segments were mounted in myographs and the contractile responses to ET-1 and sarafotoxin 6c were studied. The ET(B) and ET(A) receptor mRNA levels were determined with a real-time polymerase chain reaction (PCR). The cellular localization and protein level of ET(B) receptors were evaluated by immunohistochemistry. The PKC and ERK1/2 inhibitors attenuated the contraction induced by S6c in the basilar arteries more than in the mesenteric arteries. The efficiency of the inhibitors was proportional to the incubation time. Real-time PCR showed a decrease in the ET(B) receptor mRNA levels in arteries treated with PKC or ERK inhibitors. The JNK inhibitor had a significant inhibitory effect on ET(B) receptor upregulation in the basilar arteries. Immunohistochemistry revealed that the ET(B) receptor upregulation occured in the smooth-muscle cells and that it had the same pattern as in the quantitative PCR. Our results show that the PKC, ERK1/2, and JNK are more important for the upregulation of contractile ET(B) receptors in cerebral arteries compared with mesenteric arteries. ERK1/2 seems to be more important for the ET(B) receptor upregulation, as compared with PKC and JNK. The evaluation of the time dependency suggests that the phenomenon can be reversed even after its initiation.
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Affiliation(s)
- Roya Jamali
- Division of Experimental Vascular Research, Wallenberg Neurocentrum, BMC A13, Lund University, SE-221 85 Lund, Sweden.
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Granström BW, Xu CB, Nilsson E, Vikman P, Edvinsson L. Smoking particles enhance endothelin A and endothelin B receptor-mediated contractions by enhancing translation in rat bronchi. BMC Pulm Med 2006; 6:6. [PMID: 16539723 PMCID: PMC1448182 DOI: 10.1186/1471-2466-6-6] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2005] [Accepted: 03/15/2006] [Indexed: 12/11/2022] Open
Abstract
Background Smoking is known to cause chronic inflammatory changes in the bronchi and to contribute to airway hyper-reactivity, such as in bronchial asthma. To study the effect of smoking on the endothelin system in rat airways, bronchial segments were exposed to DMSO-soluble smoking particles (DSP) from cigarette smoke, to nicotine and to DMSO, respectively. Methods Isolated rat bronchial segments were cultured for 24 hours in the presence or absence of DSP, nicotine or DMSO alone. Contractile responses to sarafotoxin 6c (a selective agonist for ETB receptors) and endothelin-1 (an ETA and ETB receptor agonist) were studied by use of a sensitive myograph. Before ET-1 was introduced, the ETB receptors were desensitized by use of S6c. The remaining contractility observed was considered to be the result of selective activation of the ETA receptors. ETA and ETB receptor mRNA expression was analyzed using real-time quantitative PCR. The location and concentration of ETA and ETB receptors were studied by means of immunohistochemistry together with confocal microscopy after overnight incubation with selective antibodies. Results After being cultured together with DSP for 24 hours the bronchial segments showed an increased contractility mediated by ETA and ETB receptors, whereas culturing them together with nicotine did not affect their contractility. The up-regulation of their contractility was blunted by cycloheximide treatment, a translational inhibitor. No significant change in the expression of ETA and ETB receptor mRNA through exposure to DMSO or to nicotine exposure alone occurred, although immunohistochemistry revealed a clear increase in ETA and ETB receptors in the smooth muscle after incubation in the presence of DSP. Taken as a whole, this is seen as the presence of a translation mechanism. Conclusion The increased contractility of rat bronchi when exposed to DSP appears to be due to a translation mechanism.
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Affiliation(s)
- Bengt W Granström
- Department of Medicine, Clinical sciences, Lund, Lund University, Sweden
| | - Cang-Bao Xu
- Department of Medicine, Clinical sciences, Lund, Lund University, Sweden
| | - Elisabeth Nilsson
- Department of Medicine, Clinical sciences, Lund, Lund University, Sweden
| | - Petter Vikman
- Department of Medicine, Clinical sciences, Lund, Lund University, Sweden
| | - Lars Edvinsson
- Department of Medicine, Clinical sciences, Lund, Lund University, Sweden
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Cao YX, Xu CB, Luo GG, Edvinsson L. Up-Regulation of alpha1A-Adrenoceptors in Rat Mesenteric Artery Involves Intracellular Signal Pathways. Basic Clin Pharmacol Toxicol 2006; 98:61-7. [PMID: 16433893 DOI: 10.1111/j.1742-7843.2006.pto_240.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The aim of the present study was to investigate if there is an altered expression of alpha-adrenoceptors during organ culture of rat mesenteric artery segments by using a sensitive pharmacological method and molecular biological techniques. Noradrenalin (NA) induced contraction via alpha1-adrenoceptors. The contraction and alpha1A-adrenoceptor mRNA levels were elevated during organ culture. Transcriptional inhibitor actinomycin D, translational inhibitor cycloheximide, protein kinase C inhibitors (staurosporine and RO31-8220) and mitogen-activated protein kinase (MAPK) pathway inhibitors (SB386023, U0126 and SB239063) prevented the increase in NA-induced contractions. The amount of alpha1A-adrenoceptor mRNA was significantly lower in the artery segments cultured for 1 day in the presence of specific MAPK extracellular signal-regulated protein kinase1/2 pathway inhibitor SB386023 than that of the cultured controls. SB386023 did not affect alpha2-adrenoceptor mRNA level. Our results suggest that the up-regulation of alpha1A-adrenoceptors involves transcription and intracellular signal transduction via the protein kinase C and the ERK 1/2 pathways.
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Affiliation(s)
- Yong-Xiao Cao
- Division of Experimental Vascular Research, Institution of Medicine, Lund University, Sweden
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