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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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2
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Yang MF, Sun SY, Lv HG, Wang WQ, Li HX, Sun JY, Zhang ZY. Ravoxertinib Improves Long-Term Neurologic Deficits after Experimental Subarachnoid Hemorrhage through Early Inhibition of Erk1/2. ACS OMEGA 2023; 8:19692-19704. [PMID: 37305289 PMCID: PMC10249378 DOI: 10.1021/acsomega.3c01296] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/26/2023] [Accepted: 05/09/2023] [Indexed: 06/13/2023]
Abstract
Extracellular signal-regulated kinase 1 and 2 (Erk1/2) signaling has been shown to be involved in brain injury after subarachnoid hemorrhage (SAH). A first-in-human phase I study reported that ravoxertinib hydrochloride (RAH), a novel Erk1/2 inhibitor, has an acceptable safety profile and pharmacodynamic effects. Here, we showed that the level of Erk1/2 phosphorylation (p-Erk1/2) was significantly increased in the cerebrospinal fluid (CSF) of aneurysmal subarachnoid hemorrhage (aSAH) patients who developed poor outcomes. In a rat SAH model that was produced by the intracranial endovascular perforation method, western blot observed that the level of p-Erk1/2 was also increased in the CSF and basal cortex, showing a similar trend with aSAH patients. Immunofluorescence and western blot indicated that RAH treatment (i.c.v injection, 30 min post-SAH) attenuates the SAH-induced increase of p-Erk1/2 at 24 h in rats. RAH treatment can improve experimental SAH-induced long-term sensorimotor and spatial learning deficits that are evaluated by the Morris water maze, rotarod test, foot-fault test, and forelimb placing test. Moreover, RAH treatment attenuates neurobehavioral deficits, the blood-brain barrier damage, and cerebral edema at 72 h after SAH in rats. Furthermore, RAH treatment decreases the SAH-elevated apoptosis-related factor active caspase-3 and the necroptosis-related factor RIPK1 expression at 72 h in rats. Immunofluorescence analysis showed that RAH attenuated neuronal apoptosis but not neuronal necroptosis in the basal cortex at 72 h after SAH in rats. Altogether, our results suggest that RAH improves long-term neurologic deficits through early inhibition of Erk1/2 in experimental SAH.
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Affiliation(s)
- Ming-feng Yang
- Department
of Neurology, Second Affiliated Hospital, Shandong First Medical University & Shandong Academy of Medical
Sciences, Tai’an 271016 Shandong, People’s Republic of China
| | - Sheng-yao Sun
- Department
of Neurology, Second Affiliated Hospital, Shandong First Medical University & Shandong Academy of Medical
Sciences, Tai’an 271016 Shandong, People’s Republic of China
| | - Hai-guang Lv
- Department
of Neurology, Second Affiliated Hospital, Shandong First Medical University & Shandong Academy of Medical
Sciences, Tai’an 271016 Shandong, People’s Republic of China
| | - Wei-qi Wang
- Shandong
Provincial Hospital Affiliated to Shandong First Medical University, Ji’nan 250021, Shandong, People’s
Republic of China
| | - Han-xia Li
- Department
of Neurology, Second Affiliated Hospital, Shandong First Medical University & Shandong Academy of Medical
Sciences, Tai’an 271016 Shandong, People’s Republic of China
| | - Jing-yi Sun
- Shandong
Provincial Hospital Affiliated to Shandong First Medical University, Ji’nan 250021, Shandong, People’s
Republic of China
| | - Zong-yong Zhang
- Department
of Neurology, Second Affiliated Hospital, Shandong First Medical University & Shandong Academy of Medical
Sciences, Tai’an 271016 Shandong, People’s Republic of China
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3
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Solár P, Zamani A, Lakatosová K, Joukal M. The blood-brain barrier and the neurovascular unit in subarachnoid hemorrhage: molecular events and potential treatments. Fluids Barriers CNS 2022; 19:29. [PMID: 35410231 PMCID: PMC8996682 DOI: 10.1186/s12987-022-00312-4] [Citation(s) in RCA: 41] [Impact Index Per Article: 20.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Accepted: 01/24/2022] [Indexed: 12/12/2022] Open
Abstract
The response of the blood-brain barrier (BBB) following a stroke, including subarachnoid hemorrhage (SAH), has been studied extensively. The main components of this reaction are endothelial cells, pericytes, and astrocytes that affect microglia, neurons, and vascular smooth muscle cells. SAH induces alterations in individual BBB cells, leading to brain homeostasis disruption. Recent experiments have uncovered many pathophysiological cascades affecting the BBB following SAH. Targeting some of these pathways is important for restoring brain function following SAH. BBB injury occurs immediately after SAH and has long-lasting consequences, but most changes in the pathophysiological cascades occur in the first few days following SAH. These changes determine the development of early brain injury as well as delayed cerebral ischemia. SAH-induced neuroprotection also plays an important role and weakens the negative impact of SAH. Supporting some of these beneficial cascades while attenuating the major pathophysiological pathways might be decisive in inhibiting the negative impact of bleeding in the subarachnoid space. In this review, we attempt a comprehensive overview of the current knowledge on the molecular and cellular changes in the BBB following SAH and their possible modulation by various drugs and substances.
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Affiliation(s)
- Peter Solár
- Department of Anatomy, Cellular and Molecular Neurobiology Research Group, Faculty of Medicine, Masaryk University, 625 00, Brno, Czech Republic
- Department of Neurosurgery, Faculty of Medicine, Masaryk University and St. Anne's University Hospital Brno, Pekařská 53, 656 91, Brno, Czech Republic
| | - Alemeh Zamani
- Department of Anatomy, Cellular and Molecular Neurobiology Research Group, Faculty of Medicine, Masaryk University, 625 00, Brno, Czech Republic
| | - Klaudia Lakatosová
- Department of Anatomy, Cellular and Molecular Neurobiology Research Group, Faculty of Medicine, Masaryk University, 625 00, Brno, Czech Republic
| | - Marek Joukal
- Department of Anatomy, Cellular and Molecular Neurobiology Research Group, Faculty of Medicine, Masaryk University, 625 00, Brno, Czech Republic.
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Erdling A, Johansson SE, Radziwon‐Balicka A, Ansar S, Edvinsson L. Changes in P2Y 6 receptor-mediated vasoreactivity following focal and global ischemia. Physiol Rep 2022; 10:e15283. [PMID: 35466569 PMCID: PMC9035753 DOI: 10.14814/phy2.15283] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2022] [Revised: 04/05/2022] [Accepted: 04/07/2022] [Indexed: 06/14/2023] Open
Abstract
Ischemia, both in the form of focal thromboembolic stroke and following subarachnoid hemorrhage (SAH), causes upregulation of vasoconstrictive receptor systems within the cerebral vasculature. Descriptions regarding changes in purinergic signaling following ischemia are lacking, especially when the importance of purinergic signaling in regulating vascular tone is taken into consideration. This prompted us to evaluate changes in P2Y6 -mediated vasomotor reactivity in two different stroke models in rat. We used wire myography to measure changes in cerebral vasoreactivity to the P2Y6 agonist UDP-β-S following either experimental SAH or transient middle cerebral artery occlusion. Changes in receptor localization or receptor expression were evaluated using immunohistochemistry and quantitative flow cytometry. Transient middle cerebral artery occlusion caused an increase in Emax when compared to sham (233.6 [206.1-258.5]% vs. 161.1 [147.1-242.6]%, p = 0.0365). No such change was seen following SAH. Both stroke models were associated with increased levels of P2Y6 receptor expression in the vascular smooth muscle cells (90.94 [86.99-99.15]% and 93.79 [89.96-96.39]% vs. 80.31 [70.80-80.86]%, p = 0.021) and p = 0.039 respectively. There was no change in receptor localization in either of the stroke models. Based on these findings, we conclude that focal ischemic stroke increases vascular sensitivity to UDP-β-S by upregulating P2Y6 receptors on vascular smooth muscle cells while experimental SAH did not induce changes in vasoreactivity in spite of increased P2Y6 receptor expression.
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Affiliation(s)
- André Erdling
- Department of Clinical SciencesDivision of Experimental Vascular ResearchLund UniversityLundSweden
- Department of Cardiothoracic Surgery, Anesthesiology and Intensive CareSkane University HospitalLundSweden
- Applied Neurovascular ResearchDepartment of Clinical SciencesLund UniversityLundSweden
| | - Sara Ellinor Johansson
- Department of Clinical Experimental ResearchGlostrup Research InstituteRigshospitalet‐GlostrupGlostrupDenmark
| | - Aneta Radziwon‐Balicka
- Department of Clinical Experimental ResearchGlostrup Research InstituteRigshospitalet‐GlostrupGlostrupDenmark
| | - Saema Ansar
- Applied Neurovascular ResearchDepartment of Clinical SciencesLund UniversityLundSweden
| | - Lars Edvinsson
- Department of Clinical SciencesDivision of Experimental Vascular ResearchLund UniversityLundSweden
- Department of Clinical Experimental ResearchGlostrup Research InstituteRigshospitalet‐GlostrupGlostrupDenmark
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Wang HB, Wang WQ, Wu QJ, Hou YJ, Li HX, Yang HJ, Yang MF, Sun BL, Zhang ZY. Negative Allosteric Modulator of mGluR1 Improves Long-Term Neurologic Deficits after Experimental Subarachnoid Hemorrhage. ACS Chem Neurosci 2020; 11:2869-2880. [PMID: 32786302 DOI: 10.1021/acschemneuro.0c00485] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
Abstract
Aneurysmal subarachnoid hemorrhage (SAH) causes permanent neurological sequelae, but the underlying mechanism needs to be further clarified. Here, we show that inhibition of metabotropic glutamate receptor 1 (mGluR1) with negative allosteric modulator JNJ16259685 improves long-term neurobehavioral outcomes in an endovascular perforation model of SAH. JNJ16259685 improves cerebrovascular dysfunction through attenuation of cerebral blood flow (CBF) reduction, cerebral vasoconstrictio, and microthrombosis formation in a rat SAH model. Moreover, JNJ16259685 reduces experimental SAH-induced long-term neuronal damage through alleviation of neuronal death and degeneration. Mechanically, JNJ16259685 maintains phosphorylation of endothelial NO synthase (eNOS) and vasodilator-stimulated phosphoprotein (VASP) and decreases apoptosis-related factors Bax, active caspase-9, and active caspase-3 following experimental SAH. Altogether, our results suggest JNJ16259685 improves long-term functional impairment through neurovascular protection.
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Affiliation(s)
- Hong-Bin Wang
- Department of Neurology, Second Affiliated Hospital; Key Laboratory of Cerebral Microcirculation, Shandong First Medical University & Shandong Academy of Medical Sciences, Taian 271016, Shandong, People’s Republic of China
| | - Wei-qi Wang
- Department of Neurology, Second Affiliated Hospital; Key Laboratory of Cerebral Microcirculation, Shandong First Medical University & Shandong Academy of Medical Sciences, Taian 271016, Shandong, People’s Republic of China
- Department of Neurology, Medical College of Qingdao University, Qingdao 266021, Shandong, People’s Republic of China
| | - Qing-Jian Wu
- Department of Emergency, Jining No. 1 People’s Hospital, Jining 272011, People’s Republic of China
| | - Ya-jun Hou
- Department of Neurology, Second Affiliated Hospital; Key Laboratory of Cerebral Microcirculation, Shandong First Medical University & Shandong Academy of Medical Sciences, Taian 271016, Shandong, People’s Republic of China
| | - Han-xia Li
- Department of Neurology, Second Affiliated Hospital; Key Laboratory of Cerebral Microcirculation, Shandong First Medical University & Shandong Academy of Medical Sciences, Taian 271016, Shandong, People’s Republic of China
| | - Hui-juan Yang
- Department of Neurology, Second Affiliated Hospital; Key Laboratory of Cerebral Microcirculation, Shandong First Medical University & Shandong Academy of Medical Sciences, Taian 271016, Shandong, People’s Republic of China
| | - Ming-feng Yang
- Department of Neurology, Second Affiliated Hospital; Key Laboratory of Cerebral Microcirculation, Shandong First Medical University & Shandong Academy of Medical Sciences, Taian 271016, Shandong, People’s Republic of China
| | - Bao-liang Sun
- Department of Neurology, Second Affiliated Hospital; Key Laboratory of Cerebral Microcirculation, Shandong First Medical University & Shandong Academy of Medical Sciences, Taian 271016, Shandong, People’s Republic of China
| | - Zong-yong Zhang
- Department of Neurology, Second Affiliated Hospital; Key Laboratory of Cerebral Microcirculation, Shandong First Medical University & Shandong Academy of Medical Sciences, Taian 271016, Shandong, People’s Republic of China
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6
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Cao L, Lindstedt I, Edvinsson ML, Ping NN, Cao YX, Edvinsson L. Secondhand cigarette smoke induces increased expression of contractile endothelin receptors in rat coronary arteries via a MEK1/2 sensitive mechanism. SCAND CARDIOVASC J 2020; 55:50-55. [PMID: 32400208 DOI: 10.1080/14017431.2020.1762916] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
OBJECTIVES Cigarette smoke, a strong risk factor for cardiovascular diseases, upregulates contractile endothelin (ET) receptors in coronary arteries. The present study examined the effects of second hand cigarette smoke exposure on the contractile endothelin receptors and the role of the MEK1/2 pathway in rat coronary arteries. Design: Rats were exposed to secondhand smoke (SHS) for 8 weeks followed by intraperitoneal injection of a MEK1/2 inhibitor, U0126 daily for another 4 weeks. Contractile responses of isolated coronary arteries were recorded by a sensitive wire myograph. The receptor protein expression levels were examined by Western blotting. Results: The results showed that SHS in vivo caused increased expression of ET receptors ETA and ETB, and that the MEK1/2 blocker U0126 significantly reversed SHS exposure-increased ETA-mediated contractile responses and protein levels. Similar alterations were observed in ETB receptors. U0126 showed dose-dependent effects on SHS-induced response on contractile property and protein levels of the ETB receptor. However, only the higher dose U0126 (15 mg/kg) had inhibitory effects on the ETA receptor. Conclusions: Taken together, our data show that SHS increases contractile ET receptors and MEK1/2 pathway inhibitor offsets SHS exposure-induced ETA and ETB receptor upregulation in rat coronary arteries.
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Affiliation(s)
- Lei Cao
- Division of Experimental Vascular Research, Institute of Clinical Sciences in Lund, Lund University, Lund, Sweden.,Department of Pharmacology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an, Shaanxi, China
| | - Isak Lindstedt
- Division of Experimental Vascular Research, Institute of Clinical Sciences in Lund, Lund University, Lund, Sweden
| | - Marie-Louise Edvinsson
- Division of Experimental Vascular Research, Institute of Clinical Sciences in Lund, Lund University, Lund, Sweden
| | - Na-Na Ping
- Department of Pharmacology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an, Shaanxi, China
| | - Yong-Xiao Cao
- Department of Pharmacology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an, Shaanxi, China
| | - Lars Edvinsson
- Division of Experimental Vascular Research, Institute of Clinical Sciences in Lund, Lund University, Lund, Sweden
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7
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Takemoto Y, Hasegawa Y, Hayashi K, Cao C, Hamasaki T, Kawano T, Mukasa A, Kim-Mitsuyama S. The Stabilization of Central Sympathetic Nerve Activation by Renal Denervation Prevents Cerebral Vasospasm after Subarachnoid Hemorrhage in Rats. Transl Stroke Res 2019; 11:528-540. [DOI: 10.1007/s12975-019-00740-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2019] [Revised: 08/22/2019] [Accepted: 09/20/2019] [Indexed: 02/07/2023]
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8
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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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Liu Y, Chen XL, Xu CB, Cao L, Lin J, Chen G, Li J. Tail vein injection of mmLDL upregulates mouse mesenteric artery ET B receptors via activation of the ERK1/2 pathway. Vascul Pharmacol 2017; 96-98:33-39. [PMID: 28797761 DOI: 10.1016/j.vph.2017.08.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2017] [Revised: 07/03/2017] [Accepted: 08/04/2017] [Indexed: 12/30/2022]
Abstract
Minimally modified low density lipoprotein (mmLDL) is a risk factor for cardiovascular disease. This study investigated the effect of mmLDL on mouse mesenteric artery endothelin type B (ETB) receptors and its molecular mechanism. Mice were injected with normal saline (NS group), mmLDL in the tail vein (mmLDL group), or with both mmLDL and an intraperitoneal injection of the ERK1/2 pathway-specific inhibitor U0126 (mmLDL+U0126 group). The dose-response curve of mesenteric artery contraction induced by sarafotoxin 6c (S6c), the ETB receptor agonist, was measured using a sensitive myograph system. ELISAs, RT-PCR and Western blot were used to determine the serum concentrations of mouse oxidized low density lipoprotein (oxLDL), intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) as well as the expression of ETB receptors, ICAM-1, VCAM-1 and phosphorylated-extracellular signal-regulated kinase 1/2 (p-ERK1/2). The S6c-induced contraction dose-response curve was significantly enhanced by mmLDL treatment and showed a significantly higher Emax value than in the NS group (P<0.001), and the ETB receptor mRNA and protein expression in the vascular wall was significantly higher than in the NS group. The serum concentration and expression of ICAM-1 and VCAM-1 were also increased by mmLDL treatment, but intraperitoneal injection of U0126 inhibited these changes as well as the increase in p-ERK1/2 protein in the vessel wall caused by mmLDL. ICAM-1 and VCAM-1 serum concentrations were positively correlated with the S6c-induced maximum contraction of blood vessels. Increased in vivo levels of mmLDL increased the serum concentrations and expression of ICAM-1 and VCAM-1 by activating the ERK1/2 pathway, resulting in the expression of ETB receptors and the enhancement of contractile function in vascular smooth muscle. Understanding the effect of mmLDL on ETB receptors and its mechanism can provide ideas for cardiovascular disease prevention and treatment.
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Affiliation(s)
- Yang Liu
- Institute of Pharmacy and Pharmacology, University of South China, Hengyang, Hu'nan, China
| | - Xiao-Lan Chen
- The First People's Hospital of Chenzhou, Xiangnan University, Chenzhou, Hu'nan, China
| | - Cang-Bao Xu
- Institute of Basic and Translational Medicine, Xi'an Medical University, Xi'an, China
| | - Lei Cao
- Department of Pharmacology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an, Shaanxi, China
| | - Jie Lin
- The First People's Hospital of Chenzhou, Xiangnan University, Chenzhou, Hu'nan, China
| | - Gen Chen
- The First People's Hospital of Chenzhou, Xiangnan University, Chenzhou, Hu'nan, China
| | - Jie Li
- The First People's Hospital of Chenzhou, Xiangnan University, Chenzhou, Hu'nan, China; Institute of Pharmacy and Pharmacology, University of South China, Hengyang, Hu'nan, China.
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10
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Sun J, Nan G. The extracellular signal-regulated kinase 1/2 pathway in neurological diseases: A potential therapeutic target (Review). Int J Mol Med 2017; 39:1338-1346. [PMID: 28440493 PMCID: PMC5428947 DOI: 10.3892/ijmm.2017.2962] [Citation(s) in RCA: 137] [Impact Index Per Article: 19.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2016] [Accepted: 04/12/2017] [Indexed: 02/06/2023] Open
Abstract
Signaling pathways are critical modulators of a variety of physiological and pathological processes, and the abnormal activation of some signaling pathways can contribute to disease progression in various conditions. As a result, signaling pathways have emerged as an important tool through which the occurrence and development of diseases can be studied, which may then lead to the development of novel drugs. Accumulating evidence supports a key role for extracellular signal-regulated kinase 1/2 (ERK1/2) signaling in the embryonic development of the central nervous system (CNS) and in the regulation of adult brain function. ERK1/2, one of the most well characterized members of the mitogen-activated protein kinase family, regulates a range of processes, from metabolism, motility and inflammation, to cell death and survival. In the nervous system, ERK1/2 regulates synaptic plasticity, brain development and repair as well as memory formation. ERK1/2 is also a potent effector of neuronal death and neuroinflammation in many CNS diseases. This review summarizes recent findings in neurobiological ERK1/2 research, with a special emphasis on findings that clarify our understanding of the processes that regulate the plethora of isoform-specific ERK functions under physiological and pathological conditions. Finally, we suggest some potential therapeutic strategies associated with agents acting on the ERK1/2 signaling to prevent or treat neurological diseases.
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Affiliation(s)
- Jing Sun
- Department of Neurology, China-Japan Union Hospital of Jilin University, Changchun, Jilin 130000, P.R. China
| | - Guangxian Nan
- Department of Neurology, China-Japan Union Hospital of Jilin University, Changchun, Jilin 130000, P.R. China
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11
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Sun J, Nan G. The Mitogen-Activated Protein Kinase (MAPK) Signaling Pathway as a Discovery Target in Stroke. J Mol Neurosci 2016; 59:90-8. [PMID: 26842916 DOI: 10.1007/s12031-016-0717-8] [Citation(s) in RCA: 151] [Impact Index Per Article: 18.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2015] [Accepted: 01/12/2016] [Indexed: 01/08/2023]
Abstract
Protein kinases are critical modulators of a variety of intracellular and extracellular signal transduction pathways, and abnormal phosphorylation events can contribute to disease progression in a variety of diseases. As a result, protein kinases have emerged as important new drug targets for small molecule therapeutics. The mitogen-activated protein kinase (MAPK) signaling pathway transmits signals from the cell membrane to the nucleus in response to a variety of different stimuli. Because this pathway controls a broad spectrum of cellular processes, including growth, inflammation, and stress responses, it is accepted as a therapeutic target for cancer and peripheral inflammatory disorders. There is also increasing evidence that MAPK is an important regulator of ischemic and hemorrhagic cerebral vascular disease, raising the possibility that it might be a drug discovery target for stroke. In this review, we discuss the MAPK signaling pathway in association with its activation in stroke-induced brain injury.
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Affiliation(s)
- Jing Sun
- Department of Neurology, China-Japan Union Hospital of Jilin University, No. 126 Xiantai Street, Changchun, 130000, Jilin, China
| | - Guangxian Nan
- Department of Neurology, China-Japan Union Hospital of Jilin University, No. 126 Xiantai Street, Changchun, 130000, Jilin, China.
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12
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Wang JJ, Chen XL, Xu CB, Jiang GF, Lin J, Liu EQ, Qin XP, Li J. The ERK1/2 pathway participates in the upregulation of the expression of mesenteric artery α1 receptors by intravenous tail injections of mmLDL in mice. Vascul Pharmacol 2015; 77:80-8. [PMID: 26545627 DOI: 10.1016/j.vph.2015.09.007] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2015] [Accepted: 09/19/2015] [Indexed: 12/17/2022]
Abstract
Minimally modified low density lipoprotein (mmLDL) is a risk factor for cardiovascular diseases. However, no studies examining the effect of mmLDL on vascular smooth muscle receptors have been released. The current study investigated the effect of mmLDL on the mesenteric artery α1 adrenoceptor and the molecular mechanisms. Mice were divided into the normal saline (NS), mmLDL, and mmLDL+U0126 groups. In the mmLDL+U0126 group, the animals were subjected to an intravenous tail injection of mmLDL and an intraperitoneal injection of U0126. Vascular tension caused by noradrenaline (NA) in mesenteric arteries was measured with a sensitive myograph system. The serum levels of oxLDL, TNF-α, and IL-1β were detected using enzyme-linked immunosorbent assays. The expressions of the α1 adrenoceptor, the α2 adrenoceptor, TNF-α, IL-1β, and pERK1/2 were detected using real-time polymerase chain reactions and Western blot analysis. Compared with the NS group, the mmLDL group exhibited a noticeably enhanced NA shrinkage dose-response curve and a significantly increased Emax value (P<0.01). Prazosin (α1 adrenoceptor antagonist) caused a noticeable right shift of the dose-response curve. U0126 inhibited the increases in the serum levels and vessel wall expression of IL-1β and TNF-α and enhanced the NA shrinkage dose-response curve caused by mmLDL, as observed by a significantly decreased Emax value (P<0.01). It inhibited the increased α1 adrenoceptor expression caused by mmLDL. The serum levels of IL-1β and TNF-α demonstrated a positive correlation with the NA-induced maximum shrinkage percentage. U0126 inhibited the mmLDL-induced increase in the pERK1/2 protein level in the vessel wall. In conclusion, mmLDL increased the serum levels of IL-1β and TNF-α in vivo by activating the ERK1/2 pathway, which resulted in α1 receptor-mediated vasoconstriction and an increase in the expression of α1 adrenoceptor. The results of this study may provide new ideas for the prevention and cure of cardiovascular diseases in the future.
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Affiliation(s)
- Jun-Jie Wang
- The First People's Hospital of Chenzhou, Xiangnan University, Chenzhou, Hu'nan, China
| | - Xiao-Lan Chen
- The First People's Hospital of Chenzhou, Xiangnan University, Chenzhou, Hu'nan, China
| | - Cang-Bao Xu
- Institute of Basic and Translational Medicine, Xi'an Medical University, Xi'an, China
| | - Gao-Feng Jiang
- Institute of Pharmacy and Pharmacology, University of South China, Hengyang, Hu'nan, China
| | - Jie Lin
- The First People's Hospital of Chenzhou, Xiangnan University, Chenzhou, Hu'nan, China
| | - En-Qi Liu
- Laboratory Animal Center, Xi'an Jiaotong University School of Medicine, Xi'an, China
| | - Xu-Ping Qin
- Institute of Pharmacy and Pharmacology, University of South China, Hengyang, Hu'nan, China
| | - Jie Li
- The First People's Hospital of Chenzhou, Xiangnan University, Chenzhou, Hu'nan, China; Institute of Pharmacy and Pharmacology, University of South China, Hengyang, Hu'nan, China.
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13
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Xiao X, Wang R, Cao L, Shen ZX, Cao YX. The Role of MAPK Pathways in Airborne Fine Particulate Matter-Induced Upregulation of Endothelin Receptors in Rat Basilar Arteries. Toxicol Sci 2015; 149:213-26. [PMID: 26496744 DOI: 10.1093/toxsci/kfv229] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Airborne fine particulate matter (PM(2.5)) increases the risk of cerebrovascular diseases. However, existing experimental data do not sufficiently explain how PM(2.5) affects cerebral vessels. This study sought to examine whether PM(2.5) alters endothelin (ET) receptor expression on rat cerebral arteries and the potential underlying mechanisms. Isolated rat basilar arteries were cultured with PM(2.5) aqueous suspension in the presence of mitogen-activated protein kinase (MAPK) pathway inhibitors. ET receptor-mediated vasomotor functions were recorded by a sensitive myograph. ET(A) and ET(B) receptor mRNA and protein expressions were assessed using quantitative real-time PCR, Western blotting, and immunohistochemistry, respectively. Compared with fresh and culture alone arteries, PM(2.5) significantly enhanced ET(A) and ET(B) receptor-mediated contractions and increased receptor mRNA and protein expressions in basilar arteries, indicating PM(2.5) upregulates ET(A) and ET(B) receptors. Culturing with SB386023 (MEK/ERK1/2 inhibitor), U0126 (ERK1/2 inhibitor), SP600125 [c-Jun N-terminal kinase (JNK) inhibitor], or SB203580 (p38 inhibitor) attenuated PM(2.5)-induced ETB receptor upregulation. PM(2.5)-induced enhancement of ET(A) receptor-mediated contraction and receptor expression was notably inhibited by SB386023 or U0126. However, neither SP600125 nor SB203580 had an effect on PM(2.5)-induced ET(A) receptor upregulation. In conclusion, PM(2.5) upregulates ET(A) and ET(B) receptors in rat basilar arteries. ET(B) receptor upregulation is involved in MEK/ERK1/2, JNK, and p38 MAPK pathways, and ET(A) receptors upregulation is associated with MEK/ERK1/2 pathway.
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Affiliation(s)
- Xue Xiao
- *Department of Pharmacology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an, Shaanxi 710061, China
| | - Rong Wang
- *Department of Pharmacology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an, Shaanxi 710061, China
| | - Lei Cao
- *Department of Pharmacology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an, Shaanxi 710061, China;
| | - Zhen-xing Shen
- Department of Environmental Science and Engineering, Xi'an Jiaotong University, Xi'an, Shaanxi 710049, China
| | - Yong-xiao Cao
- *Department of Pharmacology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an, Shaanxi 710061, China
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14
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Hasegawa Y, Suzuki H, Uekawa K, Kawano T, Kim-Mitsuyama S. Characteristics of Cerebrovascular Injury in the Hyperacute Phase After Induced Severe Subarachnoid Hemorrhage. Transl Stroke Res 2015; 6:458-66. [DOI: 10.1007/s12975-015-0423-9] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2015] [Revised: 08/30/2015] [Accepted: 09/01/2015] [Indexed: 10/23/2022]
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15
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Durgan DJ, Crossland RF, Lloyd EE, Phillips SC, Bryan RM. Increased cerebrovascular sensitivity to endothelin-1 in a rat model of obstructive sleep apnea: a role for endothelin receptor B. J Cereb Blood Flow Metab 2015; 35:402-11. [PMID: 25425077 PMCID: PMC4348382 DOI: 10.1038/jcbfm.2014.214] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/12/2014] [Revised: 09/30/2014] [Accepted: 11/05/2014] [Indexed: 11/09/2022]
Abstract
Obstructive sleep apnea (OSA) is associated with cerebrovascular diseases. However, little is known regarding the effects of OSA on the cerebrovascular wall. We tested the hypothesis that OSA augments endothelin-1 (ET-1) constrictions of cerebral arteries. Repeated apneas (30 or 60 per hour) were produced in rats during the sleep cycle (8 hours) by remotely inflating a balloon implanted in the trachea. Four weeks of apneas produced a 23-fold increase in ET-1 sensitivity in isolated and pressurized posterior cerebral arteries (PCAs) compared with PCAs from sham-operated rats (EC50=10(-9.2) mol/L versus 10(-10.6) mol/L; P<0.001). This increased sensitivity was abolished by the ET-B receptor antagonist, BQ-788. Constrictions to the ET-B receptor agonist, IRL-1620, were greater in PCAs from rats after 2 or 4 weeks of apneas compared with that from sham-operated rats (P=0.013). Increased IRL-1620 constrictions in PCAs from OSA rats were normalized with the transient receptor potential channel (TRPC) blocker, SKF96365, or the Rho kinase (ROCK) inhibitor, Y27632. These data show that OSA increases the sensitivity of PCAs to ET-1 through enhanced ET-B activity, and enhanced activity of TRPCs and ROCK. We conclude that enhanced ET-1 signaling is part of a pathologic mechanism associated with adverse cerebrovascular outcomes of OSA.
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Affiliation(s)
- David J Durgan
- Department of Anesthesiology, Baylor College of Medicine, Houston, Texas, USA
| | - Randy F Crossland
- 1] Department of Anesthesiology, Baylor College of Medicine, Houston, Texas, USA [2] Department of Molecular Physiology and Biophysics (Graduate Program in Cardiovascular Sciences), Baylor College of Medicine, Houston, Texas, USA
| | - Eric E Lloyd
- Department of Anesthesiology, Baylor College of Medicine, Houston, Texas, USA
| | - Sharon C Phillips
- Department of Anesthesiology, Baylor College of Medicine, Houston, Texas, USA
| | - Robert M Bryan
- 1] Department of Anesthesiology, Baylor College of Medicine, Houston, Texas, USA [2] Department of Molecular Physiology and Biophysics (Graduate Program in Cardiovascular Sciences), Baylor College of Medicine, Houston, Texas, USA [3] Department of Medicine (Cardiovascular Sciences), Baylor College of Medicine, Houston, Texas, USA
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16
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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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17
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Liu YH, Liu Y, Chen JY, Zhou YL, Chen ZJ, Yu DQ, Luo JF, Li HL, He YT, Ye P, Ran P, Guo W, Tan N. LDL cholesterol as a novel risk factor for contrast-induced acute kidney injury in patients undergoing percutaneous coronary intervention. Atherosclerosis 2014; 237:453-9. [PMID: 25463073 DOI: 10.1016/j.atherosclerosis.2014.10.022] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/31/2014] [Revised: 09/16/2014] [Accepted: 10/04/2014] [Indexed: 12/29/2022]
Abstract
BACKGROUND Low density lipoprotein cholesterol (LDL-C) is associated with endothelial dysfunction, inflammation and increased vasoconstriction, which are involved in the development of contrast-induced acute kidney injury (CI-AKI). However, whether LDL-C is an independent risk factor of CI-AKI in patients undergoing percutaneous coronary intervention (PCI) is unknown. METHODS We prospectively enrolled 3236 consecutive patients undergoing PCI between January 2010 and September 2012. Multivariate logistic regression analysis was used to determine whether LDL-C is an independent risk factor of CI-AKI. CI-AKI was defined as an absolute increase in serum creatinine of ≥ 0.5 mg/dL or ≥ 25% over the baseline value within 48-72 h after contrast exposure. RESULTS CI-AKI was observed in 338 patients (10.4%). Patients with CI-AKI had a significantly higher rate of in hospital mortality (4.4% vs. 0.5%, p < 0.001), and significantly higher rates of other in hospital complications compared with those without CI-AKI. The LDL-C quartiles were as follows: Q1 (<2.04 mmol/L), Q2 (2.04-2.61 mmol/L), Q3 (2.61-3.21 mmol/L) and Q4 (>3.21 mmol/L). Patients with high baseline LDL-C levels were more likely to develop CI-AKI and composite end points including all-cause mortality, renal replacement therapy, non-fatal myocardial infarction, acute heart failure, target vessel revascularization or cerebrovascular accident during the observation period of hospitalization (8.9%, 9.9%, 10.5%, 12.6%, p = 0.001, and 5.0%, 5.2%, 6.1%, 8.1%, respectively; p = 0.007). Univariate logistic analysis showed that LDL-C levels (increment 1 mmol/L) were significantly associated with CI-AKI (odds ratio = 1.25, 95% confidence interval (CI), 1.11-1.39, p < 0.001). Furthermore, LDL-C remained a significant risk factor of CI-AKI (odds ratio = 1.23, 95% CI, 1.04-1.45, p = 0.014), even after adjusting for potential confounding risk factors. CONCLUSIONS Measurement of plasma LDL-C concentrations in patients undergoing PCI may be helpful to identify those who are at risk of CI-AKI and poor in hospital outcomes.
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Affiliation(s)
- Yuan-hui Liu
- Southern Medical University, Guangzhou 510515, Guangdong, China; Department of Cardiology, Guangdong Cardiovascular Institute, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou 510100, Guangdong, China
| | - Yong Liu
- Department of Cardiology, Guangdong Cardiovascular Institute, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou 510100, Guangdong, China
| | - Ji-yan Chen
- Department of Cardiology, Guangdong Cardiovascular Institute, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou 510100, Guangdong, China
| | - Ying-ling Zhou
- Department of Cardiology, Guangdong Cardiovascular Institute, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou 510100, Guangdong, China
| | - Zhu-jun Chen
- Department of Cardiology, Guangdong Cardiovascular Institute, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou 510100, Guangdong, China
| | - Dan-qing Yu
- Department of Cardiology, Guangdong Cardiovascular Institute, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou 510100, Guangdong, China
| | - Jian-fang Luo
- Department of Cardiology, Guangdong Cardiovascular Institute, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou 510100, Guangdong, China
| | - Hua-long Li
- Department of Cardiology, Guangdong Cardiovascular Institute, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou 510100, Guangdong, China
| | - Yi-ting He
- Department of Cardiology, Guangdong Cardiovascular Institute, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou 510100, Guangdong, China
| | - Piao Ye
- Department of Cardiology, Guangdong Cardiovascular Institute, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou 510100, Guangdong, China
| | - Peng Ran
- Department of Cardiology, Guangdong Cardiovascular Institute, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou 510100, Guangdong, China
| | - Wei Guo
- Department of Cardiology, Guangdong Cardiovascular Institute, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou 510100, Guangdong, China
| | - Ning Tan
- Department of Cardiology, Guangdong Cardiovascular Institute, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou 510100, Guangdong, China.
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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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Chen S, Feng H, Sherchan P, Klebe D, Zhao G, Sun X, Zhang J, Tang J, Zhang JH. Controversies and evolving new mechanisms in subarachnoid hemorrhage. Prog Neurobiol 2014; 115:64-91. [PMID: 24076160 PMCID: PMC3961493 DOI: 10.1016/j.pneurobio.2013.09.002] [Citation(s) in RCA: 270] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2013] [Revised: 09/07/2013] [Accepted: 09/12/2013] [Indexed: 12/13/2022]
Abstract
Despite decades of study, subarachnoid hemorrhage (SAH) continues to be a serious and significant health problem in the United States and worldwide. The mechanisms contributing to brain injury after SAH remain unclear. Traditionally, most in vivo research has heavily emphasized the basic mechanisms of SAH over the pathophysiological or morphological changes of delayed cerebral vasospasm after SAH. Unfortunately, the results of clinical trials based on this premise have mostly been disappointing, implicating some other pathophysiological factors, independent of vasospasm, as contributors to poor clinical outcomes. Delayed cerebral vasospasm is no longer the only culprit. In this review, we summarize recent data from both experimental and clinical studies of SAH and discuss the vast array of physiological dysfunctions following SAH that ultimately lead to cell death. Based on the progress in neurobiological understanding of SAH, the terms "early brain injury" and "delayed brain injury" are used according to the temporal progression of SAH-induced brain injury. Additionally, a new concept of the vasculo-neuronal-glia triad model for SAH study is highlighted and presents the challenges and opportunities of this model for future SAH applications.
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Affiliation(s)
- Sheng Chen
- Department of Neurosurgery, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China; Department of Physiology & Pharmacology, Loma Linda University, Loma Linda, CA, USA
| | - Hua Feng
- Department of Neurosurgery, Southwest Hospital, Third Military Medical University, Chongqing, China
| | - Prativa Sherchan
- Department of Physiology & Pharmacology, Loma Linda University, Loma Linda, CA, USA
| | - Damon Klebe
- Department of Physiology & Pharmacology, Loma Linda University, Loma Linda, CA, USA
| | - Gang Zhao
- Department of Neurology, Xijing Hospital, Fourth Military Medical University, Xi'an, Shanxi, China
| | - Xiaochuan Sun
- Department of Neurosurgery, First Affiliated Hospital, Chongqing Medical University, Chongqing, China
| | - Jianmin Zhang
- Department of Neurosurgery, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China
| | - Jiping Tang
- Department of Physiology & Pharmacology, Loma Linda University, Loma Linda, CA, USA
| | - John H Zhang
- Department of Physiology & Pharmacology, Loma Linda University, Loma Linda, CA, USA; Department of Neurosurgery, Loma Linda University, Loma Linda, CA, USA.
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Johansson SE, Larsen SS, Povlsen GK, Edvinsson L. Early MEK1/2 inhibition after global cerebral ischemia in rats reduces brain damage and improves outcome by preventing delayed vasoconstrictor receptor upregulation. PLoS One 2014; 9:e92417. [PMID: 24642693 PMCID: PMC3958517 DOI: 10.1371/journal.pone.0092417] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2013] [Accepted: 02/21/2014] [Indexed: 11/18/2022] Open
Abstract
Background Global cerebral ischemia following cardiac arrest is associated with increased cerebral vasoconstriction and decreased cerebral blood flow, contributing to delayed neuronal cell death and neurological detriments in affected patients. We hypothesize that upregulation of contractile ETB and 5-HT1B receptors, previously demonstrated in cerebral arteries after experimental global ischemia, are a key mechanism behind insufficient perfusion of the post-ischemic brain, proposing blockade of this receptor upregulation as a novel target for prevention of cerebral hypoperfusion and delayed neuronal cell death after global cerebral ischemia. The aim was to characterize the time-course of receptor upregulation and associated neuronal damage after global ischemia and investigate whether treatment with the MEK1/2 inhibitor U0126 can prevent cerebrovascular receptor upregulation and thereby improve functional outcome after global cerebral ischemia. Incomplete global cerebral ischemia was induced in Wistar rats and the time-course of enhanced contractile responses and the effect of U0126 in cerebral arteries were studied by wire myography and the neuronal cell death by TUNEL. The expression of ETB and 5-HT1B receptors was determined by immunofluorescence. Results Enhanced vasoconstriction peaked in fore- and midbrain arteries 3 days after ischemia. Neuronal cell death appeared initially in the hippocampus 3 days after ischemia and gradually increased until 7 days post-ischemia. Treatment with U0126 normalised cerebrovascular ETB and 5-HT1B receptor expression and contractile function, reduced hippocampal cell death and improved survival rate compared to vehicle treated animals. Conclusions Excessive cerebrovascular expression of contractile ETB and 5-HT1B receptors is a delayed response to global cerebral ischemia peaking 3 days after the insult, which likely contributes to the development of delayed neuronal damage. The enhanced cerebrovascular contractility can be prevented by treatment with the MEK1/2 inhibitor U0126, diminishes neuronal damage and improves survival rate, suggesting MEK1/2 inhibition as a novel strategy for early treatment of neurological consequences following global cerebral ischemia.
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Affiliation(s)
- Sara Ellinor Johansson
- Department of Clinical Experimental Research, Glostrup Research Institute, Glostrup Hospital, Glostrup, Denmark
- * E-mail:
| | - Stine Schmidt Larsen
- Department of Clinical Experimental Research, Glostrup Research Institute, Glostrup Hospital, Glostrup, Denmark
| | - Gro Klitgaard Povlsen
- Department of Clinical Experimental Research, Glostrup Research Institute, Glostrup Hospital, Glostrup, Denmark
| | - Lars Edvinsson
- Department of Clinical Experimental Research, Glostrup Research Institute, Glostrup Hospital, Glostrup, Denmark
- Division of Experimental Vascular Research, Department of Clinical Sciences, Lund University, Lund, Sweden
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Edvinsson L, Larsen SS, Maddahi A, Nielsen J. Plasticity of cerebrovascular smooth muscle cells after subarachnoid hemorrhage. Transl Stroke Res 2014; 5:365-76. [PMID: 24449486 DOI: 10.1007/s12975-014-0331-4] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2013] [Revised: 12/19/2013] [Accepted: 01/06/2014] [Indexed: 12/27/2022]
Abstract
Subarachnoid hemorrhage (SAH) is most often followed by a delayed phase of cerebral ischemia which is associated with high morbidity and mortality rates. The causes underlying this delayed phase are still unsettled, but are believed to include cerebral vasospasm, cortical spreading depression, inflammatory reactions, and microthrombosis. Additionally, a large body of evidence indicates that vascular plasticity plays an important role in SAH pathophysiology, and this review aims to summarize our current knowledge on the phenotypic changes of vascular smooth muscle cells of the cerebral vasculature following SAH. In light of the emerging view that the whole cerebral vasculature and the cells of the brain parenchyma should be viewed as one integrated neurovascular network, phenotypical changes are discussed both for the cerebral arteries and the microvasculature. Furthermore, the intracellular signaling involved in the vascular plasticity is discussed with a focus on the Raf-MEK1/2-ERK1/2 pathway which seems to play a crucial role in SAH pathology.
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Affiliation(s)
- Lars Edvinsson
- Department of Clinical Experimental Research, Glostrup Research Institute, Glostrup University Hospital, Glostrup, Denmark,
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22
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Low density lipoprotein induces upregulation of vasoconstrictive endothelin type B receptor expression. Vascul Pharmacol 2014; 60:42-8. [DOI: 10.1016/j.vph.2013.11.004] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2013] [Revised: 11/25/2013] [Accepted: 11/27/2013] [Indexed: 11/22/2022]
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23
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Cao L, Cao YX, Xu CB, Edvinsson L. Altered endothelin receptor expression and affinity in spontaneously hypertensive rat cerebral and coronary arteries. PLoS One 2013; 8:e73761. [PMID: 24023902 PMCID: PMC3759417 DOI: 10.1371/journal.pone.0073761] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2013] [Accepted: 07/23/2013] [Indexed: 11/21/2022] Open
Abstract
Background Hypertension is associated with arterial hyperreactivity, and endothelin (ET) receptors are involved in vascular pathogenesis. The present study was performed to examine the hypothesis that ET receptors were altered in cerebral and coronary arteries of spontaneously hypertensive rats (SHR). Methodology/Principal Findings Cerebral and coronary arteries were removed from SHR. Vascular contraction was recorded using a sensitive myograph system. Real-time PCR and Western blotting were used to quantify mRNA and protein expression of receptors and essential MAPK pathway molecules. The results demonstrated that both ETA and ETB receptor-mediated contractile responses in SHR cerebral arteries were shifted to the left in a nonparallel manner with increased maximum contraction compared with Wistar-Kyoto (WKY) rats. In SHR coronary arteries, the ETA receptor-mediated contraction curve was shifted to the left in parallel with an increased pEC50 compared with the arteries in WKY rats. There was no significant increase in ETB receptor-mediated contraction in SHR coronary arteries. ETA receptor mRNA and protein expression was increased in SHR cerebral arteries compared with the arteries in WKY rats. However, ETA receptor mRNA and protein levels in coronary arteries and ETB receptor protein levels in cerebral and coronary arteries remained unchanged in SHR compared with WKY rats. Meanwhile, phosphorylated ERK1/2 protein was significantly increased in SHR brain and heart vessels. Conclusions/Significance In SHR cerebral arteries, ETA receptor expression was upregulated. ETA receptor affinity was increased in coronary arteries, and ETB receptor affinity was increased in cerebral arteries. The ERK1/2 activation may be involved in the receptor alterations.
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Affiliation(s)
- Lei Cao
- Division of Experimental Vascular Research, Institute of Clinical Sciences in Lund, Lund University, Sweden
- * E-mail:
| | - Yong-Xiao Cao
- Department of Pharmacology, Xi’an Jiaotong University College of Medicine, Xi’an, Shaanxi, People’s Republic of China
| | - Cang-Bao Xu
- Division of Experimental Vascular Research, Institute of Clinical Sciences in Lund, Lund University, Sweden
- Institute of Basic and Translational Medicine, Xi’an Medical University, Xi’an, Shaanxi, People’s Republic of China
| | - Lars Edvinsson
- Division of Experimental Vascular Research, Institute of Clinical Sciences in Lund, Lund University, Sweden
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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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25
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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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26
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Povlsen GK, Johansson SE, Larsen CC, Samraj AK, Edvinsson L. Early events triggering delayed vasoconstrictor receptor upregulation and cerebral ischemia after subarachnoid hemorrhage. BMC Neurosci 2013; 14:34. [PMID: 23496889 PMCID: PMC3618233 DOI: 10.1186/1471-2202-14-34] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2012] [Accepted: 03/07/2013] [Indexed: 11/17/2022] Open
Abstract
BACKGROUND Upregulation of vasoconstrictor receptors in cerebral arteries, including endothelin B (ETB) and 5-hydroxytryptamine 1B (5-HT(1B)) receptors, has been suggested to contribute to delayed cerebral ischemia, a feared complication after subarachnoid hemorrhage (SAH). This receptor upregulation has been shown to be mediated by intracellular signalling via the mitogen activated protein kinase kinase (MEK1/2)--extracellular regulated kinase 1/2 (ERK1/2) pathway. However, it is not known what event(s) that trigger MEK-ERK1/2 activation and vasoconstrictor receptor upregulation after SAH.We hypothesise that the drop in cerebral blood flow (CBF) and wall tension experienced by cerebral arteries in acute SAH is a key triggering event. We here investigate the importance of the duration of this acute CBF drop in a rat SAH model in which a fixed amount of blood is injected into the prechiasmatic cistern either at a high rate resulting in a short acute CBF drop or at a slower rate resulting in a prolonged acute CBF drop. RESULTS We demonstrate that the duration of the acute CBF drop is determining for a) degree of early ERK1/2 activation in cerebral arteries, b) delayed upregulation of vasoconstrictor receptors in cerebral arteries and c) delayed CBF reduction, neurological deficits and mortality. Moreover, treatment with an inhibitor of MEK-ERK1/2 signalling during an early time window from 6 to 24 h after SAH was sufficient to completely prevent delayed vasoconstrictor receptor upregulation and improve neurological outcome several days after the SAH. CONCLUSIONS Our findings suggest a series of events where 1) the acute CBF drop triggers early MEK-ERK1/2 activation, which 2) triggers the transcriptional upregulation of vasoconstrictor receptors in cerebral arteries during the following days, where 3) the resulting enhanced cerebrovascular contractility contribute to delayed cerebral ischemia.
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Affiliation(s)
- Gro Klitgaard Povlsen
- Department of Clinical Experimental Research, Glostrup Research Institute, Glostrup University Hospital, Nordre Ringvej 69, Glostrup, DK 2600, Denmark
| | - Sara Ellinor Johansson
- Department of Clinical Experimental Research, Glostrup Research Institute, Glostrup University Hospital, Nordre Ringvej 69, Glostrup, DK 2600, Denmark
| | | | - Ajoy Kumar Samraj
- Department of Clinical Experimental Research, Glostrup Research Institute, Glostrup University Hospital, Nordre Ringvej 69, Glostrup, DK 2600, Denmark
| | - Lars Edvinsson
- Department of Clinical Experimental Research, Glostrup Research Institute, Glostrup University Hospital, Nordre Ringvej 69, Glostrup, DK 2600, Denmark
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27
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Ansar S, Eftekhari S, Waldsee R, Nilsson E, Nilsson O, Säveland H, Edvinsson L. MAPK signaling pathway regulates cerebrovascular receptor expression in human cerebral arteries. BMC Neurosci 2013; 14:12. [PMID: 23343134 PMCID: PMC3663811 DOI: 10.1186/1471-2202-14-12] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2012] [Accepted: 12/26/2012] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Cerebral ischemia results in enhanced expression of contractile cerebrovascular receptors, such as endothelin type B (ET(B)), 5-hydroxytryptamine type 1B (5-HT(1B)), angiotensin II type 1 (AT(1)) and thromboxane (TP) receptors in the cerebral arteries within the ischemic area. The receptor upregulation occurs via activation of the mitogen-activated protein kinases (MAPK) pathway. Previous studies have shown that inhibitors of the MAPK pathway diminished the ischemic area and contractile cerebrovascular receptors after experimental cerebral ischemia. The aim of this study was to examine if the upregulation of contractile cerebrovascular receptors after 48 h of organ culture of human cerebral arteries involves MAPK pathways and if it can be prevented by a MEK1/2 inhibitor. Human cerebral arteries were obtained from patients undergoing intracranial tumor surgery. The vessels were divided into ring segments and incubated for 48 h in the presence or absence of the specific MEK1/2 inhibitor U0126. The vessels were then examined by using in vitro pharmacological methods and protein immunohistochemistry. RESULTS After organ culture of the cerebral arteries the contractile responses to endothelin (ET)-1, angiotensin (Ang) II and thromboxane (TP) were enhanced in comparison with fresh human arteries. However, 5-carboxamidotryptamine (5-CT) induced decreased contractile responses after organ culture as compared to fresh arteries. Incubation with U0126 diminished the maximum contraction elicited by application of ET-1, Ang II and U46619 in human cerebral arteries. In addition, the MEK1/2 inhibitor decreased the contractile response to 5-CT. Immunohistochemistry revealed that organ culture resulted in increased expression of endothelin ET(A), endothelin ET(B) angiotensin AT(2), 5-hydroxytryptamine 5-HT(1B) and thromboxane A2 receptors, and elevated levels of activated pERK1/2, all localized to the smooth muscle cells of the cerebral arteries. Co-incubation with U0126 normalized these proteins. CONCLUSION The study demonstrated that there is a clear association between human cerebrovascular receptor upregulation via transcription involving activation of the MAPK pathway after organ culture. Inhibition of the MAPK pathways attenuated the vasoconstriction mediated by ET, AT and TP receptors in human cerebral arteries and the enhanced expression of their receptors. The results indicate that MAPK inhibition might be a novel target for treatment of cerebrovascular disorders.
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Affiliation(s)
- Saema Ansar
- Department of Clinical Sciences, Division of Experimental Vascular Research, Lund University, Lund, Sweden.
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28
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Cao L, Xu CB, Zhang Y, Cao YX, Edvinsson L. Secondhand cigarette smoke exposure causes upregulation of cerebrovascular 5-HT(1) (B) receptors via the Raf/ERK/MAPK pathway in rats. Acta Physiol (Oxf) 2013; 207:183-93. [PMID: 22883081 DOI: 10.1111/j.1748-1716.2012.02478.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2012] [Revised: 05/03/2012] [Accepted: 08/06/2012] [Indexed: 11/28/2022]
Abstract
AIM Cigarette smoke exposure increases the risk of stroke. Upregulation of 5-hydroxytryptamine 1B (5-HT(1) (B) ) receptors is associated with the pathogenesis of cerebral ischaemia. This study examined the hypothesis that the expression of 5-HT(1) (B) receptors is altered in brain vessels after secondhand smoke (SHS) exposure. METHODS Rats were exposed to SHS in vivo for 200 min daily for 8 weeks. The contractile responses of isolated cerebral arteries were studies by a sensitive myograph. The mRNA and protein expression for 5-HT(1) (B) receptors were examined by real-time PCR, Western blot and immunofluorescence respectively. In addition, the phosphorylation of Raf/extracellular signal-regulated kinase (ERK)/mitogen-activated protein kinases (MAPK) pathway was evaluated. RESULTS The results showed that SHS exposure shifted the 5-HT(1) (B) receptor-mediated concentration-contraction curve towards the left with a markedly increased maximal contraction. Furthermore, there were significant elevations in mRNA level and protein expression of 5-HT(1) (B) receptors in SHS-exposed rats. Immunostaining revealed that the 5-HT(1) (B) receptors were localized to the smooth muscle cells of cerebral arteries. SHS was also found to induce the phosphorylation of Raf-1 and ERK1/2 proteins. The administration of a Raf-1 inhibitor GW5074 attenuated the 5-HT(1) (B) receptor upregulation. CONCLUSION Secondhand smoke exposure upregulates cerebrovascular 5-HT(1) (B) receptors in rats. The receptor upregulation is associated with Raf/ERK/MAPK activation.
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Affiliation(s)
- L. Cao
- Division of Experimental Vascular Research; Department of Clinical Sciences; Lund University; Lund; Sweden
| | - C. B. Xu
- Division of Experimental Vascular Research; Department of Clinical Sciences; Lund University; Lund; Sweden
| | - Y. Zhang
- Division of Experimental Vascular Research; Department of Clinical Sciences; Lund University; Lund; Sweden
| | - Y. X. Cao
- Department of Pharmacology; Xi'an Jiaotong University College of Medicine; Xi'an; Shaanxi; China
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Caner B, Hou J, Altay O, Fuj M, Zhang JH. Transition of research focus from vasospasm to early brain injury after subarachnoid hemorrhage. J Neurochem 2012; 123 Suppl 2:12-21. [DOI: 10.1111/j.1471-4159.2012.07939.x] [Citation(s) in RCA: 119] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Basak Caner
- Department of Physiology; Loma Linda University, School of Medicine; Loma Linda; California; USA
| | - Jack Hou
- Department of Physiology; Loma Linda University, School of Medicine; Loma Linda; California; USA
| | - Orhan Altay
- Department of Physiology; Loma Linda University, School of Medicine; Loma Linda; California; USA
| | - Mutsumi Fuj
- Department of Physiology; Loma Linda University, School of Medicine; Loma Linda; California; USA
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30
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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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31
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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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32
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Cao L, Zhang Y, Cao YX, Edvinsson L, Xu CB. Cigarette smoke upregulates rat coronary artery endothelin receptors in vivo. PLoS One 2012; 7:e33008. [PMID: 22412974 PMCID: PMC3296776 DOI: 10.1371/journal.pone.0033008] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2011] [Accepted: 02/02/2012] [Indexed: 11/28/2022] Open
Abstract
BACKGROUND Cigarette smoking is a strong cardiovascular risk factor and endothelin (ET) receptors are related to coronary artery diseases. The present study established an in vivo secondhand smoke (SHS) exposure model and investigated the hypothesis that cigarette smoke induces ET receptor upregulation in rat coronary arteries and its possible underlying mechanisms. METHODOLOGY/PRINCIPAL FINDINGS Rats were exposed to SHS for 200 min daily for 8 weeks. The coronary arteries were isolated and examined. The vasoconstriction was studied by a sensitive myograph. The expression of mRNA and protein for receptors was examined by real-time PCR, Western blot and immunofluorescence. Compared to fresh air exposure, SHS increased contractile responses mediated by endothelin type A (ET(A)) and type B (ET(B)) receptors in coronary arteries. In parallel, the expression of mRNA and protein for ET(A) and ET(B) receptors of smoke exposed rats were higher than that of animals exposed to fresh air, suggesting that SHS upregulates ET(A) and ET(B) receptors in coronary arteries in vivo. Immunofluorescence staining showed that the enhanced receptor expression was localized to the smooth muscle cells of coronary arteries. The protein levels of phosphorylated (p)-Raf-1 and p-ERK1/2 in smoke exposed rats were significantly higher than in control rats, demonstrating that SHS induces the activation of the Raf/ERK/MAPK pathway. Treatment with Raf-1 inhibitor GW5074 suppressed SHS-induced enhanced contraction mediated by ET(A) receptors, and inhibited the elevated mRNA and protein levels of ET(A) and ET(B) receptors caused by SHS. The results of correlation and regression analysis showed that phosphorylation of Raf and ERK1/2 were independent determinants to affect protein expression of ET(B) and ET(A) receptors. CONCLUSIONS/SIGNIFICANCE Cigarette smoke upregulates ET(B) and ET(A) receptors in rat coronary artery, which is associated with the activation of the Raf/ERK/MAPK pathway.
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Affiliation(s)
- Lei Cao
- Division of Experimental Vascular Research, Institute of Clinical Science in Lund, Lund University, Lund, Sweden
| | - Yaping Zhang
- Division of Experimental Vascular Research, Institute of Clinical Science in Lund, Lund University, Lund, Sweden
| | - Yong-Xiao Cao
- Department of Pharmacology, Xi'an Jiaotong University College of Medicine, Xi'an, Shaanxi, People's Republic of China
| | - Lars Edvinsson
- Division of Experimental Vascular Research, Institute of Clinical Science in Lund, Lund University, Lund, Sweden
| | - Cang-Bao Xu
- Division of Experimental Vascular Research, Institute of Clinical Science in Lund, Lund University, Lund, Sweden
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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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Kikkawa Y, Matsuo S, Kameda K, Hirano M, Nakamizo A, Sasaki T, Hirano K. Mechanisms underlying potentiation of endothelin-1-induced myofilament Ca(2+) sensitization after subarachnoid hemorrhage. J Cereb Blood Flow Metab 2012; 32:341-52. [PMID: 21952110 PMCID: PMC3272600 DOI: 10.1038/jcbfm.2011.132] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Increased vascular smooth muscle contractility has an important role in the development of cerebral vasospasm after subarachnoid hemorrhage (SAH). Myofilament Ca(2+) sensitivity is a major determinant of smooth muscle contractility. We investigated changes in the Ca(2+)-sensitizing effect of endothelin-1 (ET-1) and the mechanisms underlying ET-1-induced Ca(2+) sensitization after SAH using a rabbit SAH model. After SAH, the contractile response to ET-1 was enhanced, and the ET(A) receptor expression was upregulated in the basilar artery. In α-toxin-permeabilized preparations, ET-1 induced enhanced and prolonged contraction after SAH, suggesting that ET-1-induced Ca(2+) sensitization is potentiated after SAH. Endothelin-1-induced Ca(2+) sensitization became less sensitive to inhibitors of Rho-associated coiled-coil protein kinase (ROCK) and protein kinase C (PKC) after SAH. The expression of PKCα, ROCK2, PKC-potentiated phosphatase inhibitor of 17 kDa (CPI-17) and myosin phosphatase target subunit 1 (MYPT1) was upregulated, and the level of phosphorylation of CPI-17 and MYPT1 was elevated after SAH. This study demonstrated for the first time that the Ca(2+)-sensitizing effect of ET-1 on myofilaments is potentiated after SAH. The increased expression and activity of PKCα, ROCK2, CPI-17, and MYPT1, as well as the upregulation of ET(A) receptor expression are suggested to underlie the enhanced and prolonged Ca(2+) sensitization induced by ET-1.
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Affiliation(s)
- Yuichiro Kikkawa
- Division of Molecular Cardiology, Research Institute of Angiocardiology, Graduate School of Medical Sciences, Kyushu University, Higashi-ku, Fukuoka, Japan
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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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36
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Inhibition of cerebrovascular raf activation attenuates cerebral blood flow and prevents upregulation of contractile receptors after subarachnoid hemorrhage. BMC Neurosci 2011; 12:107. [PMID: 22032648 PMCID: PMC3219635 DOI: 10.1186/1471-2202-12-107] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2011] [Accepted: 10/27/2011] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Late cerebral ischemia carries high morbidity and mortality after subarachnoid hemorrhage (SAH) due to reduced cerebral blood flow (CBF) and the subsequent cerebral ischemia which is associated with upregulation of contractile receptors in the vascular smooth muscle cells (SMC) via activation of mitogen-activated protein kinase (MAPK) of the extracellular signal-regulated kinase (ERK)1/2 signal pathway. We hypothesize that SAH initiates cerebrovascular ERK1/2 activation, resulting in receptor upregulation. The raf inhibitor will inhibit the molecular events upstream ERK1/2 and may provide a therapeutic window for treatment of cerebral ischemia after SAH. RESULTS Here we demonstrate that SAH increases the phosphorylation level of ERK1/2 in cerebral vessels and reduces the neurology score in rats in additional with the CBF measured by an autoradiographic method. The intracisternal administration of SB-386023-b, a specific inhibitor of raf, given 6 h after SAH, aborts the receptor changes and protects the brain from the development of late cerebral ischemia at 48 h. This is accompanied by reduced phosphorylation of ERK1/2 in cerebrovascular SMC. SAH per se enhances contractile responses to endothelin-1 (ET-1), 5-carboxamidotryptamine (5-CT) and angiotensin II (Ang II), upregulates ETB, 5-HT1B and AT1 receptor mRNA and protein levels. Treatment with SB-386023-b given as late as at 6 h but not at 12 h after the SAH significantly decreased the receptor upregulation, the reduction in CBF and the neurology score. CONCLUSION These results provide evidence for a role of the ERK1/2 pathway in regulation of expression of cerebrovascular SMC receptors. It is suggested that raf inhibition may reduce late cerebral ischemia after SAH and provides a realistic time window for therapy.
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Edvinsson L, Povlsen GK. Late cerebral ischaemia after subarachnoid haemorrhage: is cerebrovascular receptor upregulation the mechanism behind? Acta Physiol (Oxf) 2011; 203:209-24. [PMID: 21087418 DOI: 10.1111/j.1748-1716.2010.02227.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Late cerebral ischaemia after subarachnoid haemorrhage (SAH) carries high morbidity and mortality because of reduced cerebral blood flow (CBF) and subsequent cerebral ischaemia. This is associated with upregulation of contractile receptors in cerebral artery smooth muscles via the activation of intracellular signalling. In addition, delayed cerebral ischaemia after SAH is associated with inflammation and disruption of the blood-brain barrier (BBB). This article reviews recent evidence concerning the roles of vasoconstrictor receptor upregulation, inflammation and BBB breakdown in delayed cerebral ischaemia after SAH. In addition, recent studies investigating the role of various intracellular signalling pathways in these processes and the possibilities of targeting signalling components in SAH treatment are discussed. Studies using a rat SAH model have demonstrated that cerebral arteries increase their sensitivity to endogenous agonists such as ET-1 and 5-HT by increasing their smooth muscle expression of receptors for these after SAH. This is associated with reduced CBF and neurological deficits. A number of signal transduction components mediating this receptor upregulation have been identified, including the MEK-ERK1/2 pathway. Inhibition of MEK-ERK1/2 signalling has been shown to prevent cerebrovascular receptor upregulation and normalize CBF and neurological function after SAH in rats. At the same time, in rat SAH, certain cytokines and BBB-regulating proteins are upregulated in cerebral artery smooth muscles and treatment with MEK-ERK1/2 inhibitors prevents the induction of these proteins. Thus, inhibitors of MEK-ERK1/2 signalling exert multimodal beneficial effects in SAH.
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Affiliation(s)
- L Edvinsson
- Department of Medicine, Institute of Clinical Sciences, University of Lund, Sweden.
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Maddahi A, Kruse LS, Chen QW, Edvinsson L. The role of tumor necrosis factor-α and TNF-α receptors in cerebral arteries following cerebral ischemia in rat. J Neuroinflammation 2011; 8:107. [PMID: 21871121 PMCID: PMC3177895 DOI: 10.1186/1742-2094-8-107] [Citation(s) in RCA: 68] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2011] [Accepted: 08/28/2011] [Indexed: 12/21/2022] Open
Abstract
Background Tumour necrosis factor-α (TNF-α) is a pleiotropic pro-inflammatory cytokine, which is rapidly upregulated in the brain after injury. TNF-α acts by binding to its receptors, TNF-R1 (p55) and TNF-R2 (p75), on the cell surface. The aim of this study was first to investigate if there is altered expression of TNF-α and TNF-α receptors in cerebral artery walls following global or focal ischemia, and after organ culture. Secondly, we asked if the expression was regulated via activation of the MEK-ERK1/2 pathway. Methods The hypothesis was tested in vivo after subarachnoid hemorrhage (SAH) and middle cerebral artery occlusion (MCAO), and in vitro by organ culture of isolated cerebral arteries. The localization and amount of TNF-α, TNF-α receptor 1 and 2 proteins were analysed by immunohistochemistry and western blot after 24 and 48 h of organ culture and at 48 h following SAH or MCAO. In addition, cerebral arteries were incubated for 24 or 48 h in the absence or presence of a B-Raf inhibitor (SB386023-b), a MEK- inhibitor (U0126) or an NF-κB inhibitor (IMD-0354), and protein expression evaluated. Results Immunohistochemistry revealed enhanced expression of TNF-α, TNF-R1 and TNF-R2 in the walls of cerebral arteries at 48 h after MCAO and SAH compared with control. Co-localization studies showed that TNF-α, TNF-R1 and TNF-R2 were primarily localized to the cell membrane and the cytoplasm of the smooth muscle cells (SMC). There was, in addition, some expression of TNF-R2 in the endothelial cells. Immunohistochemistry and western blot analysis showed that these proteins were upregulated after 24 and 48 h in culture, and this upregulation reached an apparent maximum at 48 h of organ culture. Treatment with U0126 significantly reduced the enhanced SMC expression of TNF-α, TNF-R1 and TNF-R2 immunoreactivities after 24 and 48 h of organ culture. The Raf and NF-κB inhibitors significantly reduced organ culture induced TNF-α expression while they had minor effects on the TNF-α receptors. Conclusion The present study shows that cerebral ischemia and organ culture induce expression of TNF-α and its receptors in the walls of cerebral arteries and that upregulation is transcriptionally regulated via the MEK/ERK pathway.
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Affiliation(s)
- Aida Maddahi
- Department of Clinical Sciences, Division of Experimental Vascular Research, Lund University, Lund, Sweden.
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Edvinsson LIH, Povlsen GK. Vascular plasticity in cerebrovascular disorders. J Cereb Blood Flow Metab 2011; 31:1554-71. [PMID: 21559027 PMCID: PMC3137480 DOI: 10.1038/jcbfm.2011.70] [Citation(s) in RCA: 79] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/17/2011] [Revised: 04/06/2011] [Accepted: 04/06/2011] [Indexed: 12/31/2022]
Abstract
Cerebral ischemia remains a major cause of morbidity and mortality with little advancement in subacute treatment options. This review aims to cover and discuss novel insight obtained during the last decade into plastic changes in the vasoconstrictor receptor profiles of cerebral arteries and microvessels that takes place after different types of stroke. Receptors like the endothelin type B, angiotensin type 1, and 5-hydroxytryptamine type 1B/1D receptors are upregulated in the smooth muscle layer of cerebral arteries after different types of ischemic stroke as well as after subarachnoid hemorrhage, yielding rather dramatic changes in the contractility of the vessels. Some of the signal transduction processes mediating this receptor upregulation have been elucidated. In particular the extracellular regulated kinase 1/2 pathway, which is activated early in the process, has proven to be a promising therapeutic target for prevention of vasoconstrictor receptor upregulation after stroke. Together, those findings provide new perspectives on the pathophysiology of ischemic stroke and point toward a novel way of reducing vasoconstriction, neuronal cell death, and thus neurologic deficits after stroke.
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Affiliation(s)
- Lars I H Edvinsson
- Department of Clinical Experimental Research, Copenhagen University, Glostrup Hospital Research Park, Copenhagen, Denmark.
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Blockade of the MEK/ERK pathway with a raf inhibitor prevents activation of pro-inflammatory mediators in cerebral arteries and reduction in cerebral blood flow after subarachnoid hemorrhage in a rat model. J Cereb Blood Flow Metab 2011; 31:144-54. [PMID: 20424636 PMCID: PMC3049479 DOI: 10.1038/jcbfm.2010.62] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Cerebral ischemia that develops after subarachnoid hemorrhage (SAH) carries high morbidity and mortality. Inflammatory mediators are involved in the development of cerebral ischemia through activation of the mitogen-activated protein kinase pathway. We hypothesized that blockade of the MAPkinase/ERK (MEK)/extracellular signal-regulated kinase (ERK) pathway upstream with a specific raf inhibitor would prevent SAH-induced activation of the cerebrovascular inflammatory response. The raf inhibitor SB-386023-b was injected intracisternally in our rat model at 0, 6, or 12 hours after the SAH. After 48 hours, cerebral arteries were harvested, and iNOS, interleukin (IL)-6, IL-1β, matrix metalloproteinase (MMP)-9, tissue inhibitors of metalloproteinase (TIMP)-1, and phosphorylated ERK1/2 were investigated by immunofluorescence, real-time polymerase chain reaction (PCR), and Western blot analysis. Cerebral blood flow (CBF) was measured using autoradiography. Protein levels of MMP-9, TIMP-1, iNOS, IL-6, and IL-1β were increased after SAH, as were mRNA levels of IL-6, MMP-9, and TIMP-1. After SAH, pERK1/2 was increased, but CBF was reduced. Treatment with SB-386023-b at 0 or 6 hours after SAH normalized CBF and prevented SAH-induced upregulation of MMPs, pro-inflammatory cytokines, and pERK1/2 proteins. These results suggested that inhibition of MEK/ERK signal transduction by a specific raf inhibitor administered up to 6 hours after SAH normalized the expression of pro-inflammatory mediators and extracellular matrix-related genes.
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Suzuki H, Hasegawa Y, Kanamaru K, Zhang JH. Mitogen-activated protein kinases in cerebral vasospasm after subarachnoid hemorrhage: a review. ACTA NEUROCHIRURGICA. SUPPLEMENT 2011; 110:133-9. [PMID: 21116928 DOI: 10.1007/978-3-7091-0353-1_23] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
BACKGROUND Mitogen-activated protein kinases (MAPKs) have been implicated in the pathogenesis of cerebral vasospasm after subarachnoid hemorrhage. The goal of this review is to bring together recent diverse data concerning the roles of MAPKs in cerebral vasospasm and to consider the future research. METHOD A review of publications in the National Library of Medicine and National Institutes of Health database was conducted in August 2009 using specific keyword search terms pertaining to subarachnoid hemorrhage and MAPKs. FINDINGS There are nine in vitro studies and 17 in vivo studies published. Most of previous studies used MAPK inhibitors or their upstream molecule inhibitors, and showed that MAPK inhibitions prevented vasospasm. The MAPK cascade appears to interact with other signaling molecules, and MAPK may be an important final common pathway for the signaling transduction during cerebral vasospasm. However, the mechanism by which MAPK causes sustained vascular smooth muscle contraction remains unclear. In addition, the role of endogenous MAPK inhibitors, MAPK phosphatases, has not been investigated in cerebral vasospasm. CONCLUSIONS The experimental data support the causative role of MAPK in cerebral vasospasm and warrant further research.
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Affiliation(s)
- Hidenori Suzuki
- Department of Physiology, Loma Linda University School of Medicine, Risley Hall, Room 223, Loma Linda, CA 92354, USA
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Sehba FA, Pluta RM, Zhang JH. Metamorphosis of subarachnoid hemorrhage research: from delayed vasospasm to early brain injury. Mol Neurobiol 2010; 43:27-40. [PMID: 21161614 PMCID: PMC3023855 DOI: 10.1007/s12035-010-8155-z] [Citation(s) in RCA: 231] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2010] [Accepted: 11/24/2010] [Indexed: 01/07/2023]
Abstract
Delayed vasospasm that develops 3–7 days after aneurysmal subarachnoid hemorrhage (SAH) has traditionally been considered the most important determinant of delayed ischemic injury and poor outcome. Consequently, most therapies against delayed ischemic injury are directed towards reducing the incidence of vasospasm. The clinical trials based on this strategy, however, have so far claimed limited success; the incidence of vasospasm is reduced without reduction in delayed ischemic injury or improvement in the long-term outcome. This fact has shifted research interest to the early brain injury (first 72 h) evoked by SAH. In recent years, several pathological mechanisms that activate within minutes after the initial bleed and lead to early brain injury are identified. In addition, it is found that many of these mechanisms evolve with time and participate in the pathogenesis of delayed ischemic injury and poor outcome. Therefore, a therapy or therapies focused on these early mechanisms may not only prevent the early brain injury but may also help reduce the intensity of later developing neurological complications. This manuscript reviews the pathological mechanisms of early brain injury after SAH and summarizes the status of current therapies.
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Affiliation(s)
- Fatima A Sehba
- Department of Neurosurgery, Mount Sinai School of Medicine, Box 1136, New York, NY 10029, USA.
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Reynaud O, Ciobanu L. Post-processing correction of magnetization transfer effects in FENSI perfusion MRI data. Magn Reson Med 2010; 65:457-62. [PMID: 20859996 DOI: 10.1002/mrm.22625] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2010] [Revised: 07/14/2010] [Accepted: 08/10/2010] [Indexed: 12/20/2022]
Abstract
Magnetization transfer effects induced by repetitive saturation pulses employed in flow enhancement of signal intensity imaging sequences currently prevent quantitative, in vivo, cerebral perfusion studies. This study investigates the magnitude of these effects and introduces a post-processing correction protocol. The study shows that the magnetization transfer effect is consistent across individuals, which enables the derivation of a correction factor to be applied in post-acquisition. Our results, obtained for cerebral flux in white and gray matter in rodent brains, are in agreement with cerebral blood flow measurements previously reported in the literature.
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Xu CB, Sun Y, Edvinsson L. Cardiovascular risk factors regulate the expression of vascular endothelin receptors. Pharmacol Ther 2010; 127:148-55. [DOI: 10.1016/j.pharmthera.2010.04.013] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2010] [Accepted: 04/29/2010] [Indexed: 10/19/2022]
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Sandhu H, Ansar S, Edvinsson L. Comparison of MEK/ERK pathway inhibitors on the upregulation of vascular G-protein coupled receptors in rat cerebral arteries. Eur J Pharmacol 2010; 644:128-37. [PMID: 20615400 DOI: 10.1016/j.ejphar.2010.06.053] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2010] [Revised: 06/04/2010] [Accepted: 06/24/2010] [Indexed: 12/01/2022]
Abstract
Organ culture is an in vitro method for investigating cellular mechanisms involved in upregulation of vasocontractile G-protein coupled receptors. We hypothesize that mitogen-activated-protein kinase (MEK) and/or extracellular-signal-regulated kinase (ERK) specific inhibitors will attenuate the G-protein coupled receptor expression following organ culture. Rat cerebral arteries were incubated 48h in the presence of MEK/ERK specific inhibitors U0126, PD98059, SL327, or AG126 for different time periods. Contractile responses by activation of endothelin receptor type A and type B, serotonin receptor 5-HT(1B), prostanoid TP receptor, and angiotensin II receptor type 1 and type 2 were investigated. Results were verified by measurement of mRNA with real time PCR and by protein immunohistochemistry. Organ culture induced transcriptional upregulation of endothelin ET(B) receptor and of serotonin 5-HT(1B) receptor on translational level and increased respective contractions. The prostanoid TP receptor mediated contraction curve was left-wards shifted by organ culture. Organ culture was associated with elevated pERK1/2 in the vascular smooth muscle cells: the MEK1/2 inhibitor U0126 attenuated the endothelin ET(B) receptor mediated contraction at post-translational level or by changing the receptor affinities. The serotonin 5-HT(1B) receptor and prostanoid TP receptor mediated contractions were abolished by U0126. Administration of U0126 6h after start of incubation blocked the receptor upregulation. In conclusion, MEK specific inhibitor U0126 is a potent inhibitor of G-protein coupled receptor alteration seen during organ culture. Given the ability to inhibit G-protein coupled receptor alteration at the clinically relevant time-point 6h post incubation makes it an attractive therapeutic agent for in vivo studies.
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Affiliation(s)
- Hardip Sandhu
- Department of Clinical Experimental Research, Glostrup Research Institute, Glostrup University Hospital, Denmark.
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Larsen CC, Povlsen GK, Rasmussen MNP, Edvinsson L. Improvement in neurological outcome and abolition of cerebrovascular endothelin B and 5-hydroxytryptamine 1B receptor upregulation through mitogen-activated protein kinase kinase 1/2 inhibition after subarachnoid hemorrhage in rats. J Neurosurg 2010; 114:1143-53. [PMID: 20597604 DOI: 10.3171/2010.6.jns1018] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
OBJECT Delayed cerebral ischemia after subarachnoid hemorrhage (SAH) remains a major cause of death and disability. It has been hypothesized that cerebrovascular upregulation of vasoconstrictor receptors is a key step in the development of delayed cerebral ischemia. Upregulation of endothelin-B (ET(B)) and 5-hydroxytryptamine 1B (5-HT(1B)) receptors has been demonstrated in cerebral artery smooth muscles in the delayed ischemic phase after experimental SAH, and intracellular signaling via the mitogen-activated protein kinase kinase (MEK)-extracellular signal-regulated kinase 1/2 pathway has been shown to be involved in this upregulation. The aim in the present study was to determine whether treatment with the MEK1/2 inhibitor U0126 can prevent cerebrovascular receptor upregulation and improve functional outcome after experimental SAH in rats. METHODS Subarachnoid hemorrhage was induced in male Sprague-Dawley rats by the injection of 250 μl of autologous blood into the basal cisterns. Either U0126 or vehicle was intracisternally administered at 6, 12, 24, and 36 hours after SAH. Smooth muscle ET(B) and 5-HT(1B) receptor upregulation was studied in isolated cerebral artery segments through immunohistochemical and myographic studies of contractile responses to receptor-specific agonists. Gross sensorimotor function in the rats after SAH was assessed using a rotating pole test. RESULTS Contractile concentration-response curves for middle cerebral artery (MCA) and basilar artery (BA) segments to endothelin-1 (ET-1) and 5-carboxamidotryptamine (5-CT) were shifted leftward for SAH-induced compared with shamoperated rats due to enhanced contractile responses to individual doses of the agonists (for example, contractile responses of the BA to 3 × 10(-10) M of ET-1 and 3 × 10(-7) M of 5-CT were 9.98 ± 5.01% and 16.75 ± 3.62% of the maximal contractile capacity, respectively, in sham-operated rats and 62.78 ± 9.9% and 45.44 ± 10.62%, respectively, in SAH-induced rats). In vivo treatment with 0.19 μg/kg U0126 normalized responses in the SAH-induced rats to levels in the sham-operated rats. Protein expression of ET(B) and 5-HT(1B) receptors in cerebrovascular smooth muscles from SAH-induced rats was increased to 175 ± 33.17% and 167.7 ± 24.74%, respectively, of the levels in sham-operated rats. Endothelin-B and 5-HT(1B) expression levels in U0126-treated SAH-induced rats were at the levels in sham-operated rats (101.9 ± 13.38% and 91.44 ± 16.75%, respectively). In a rotating pole test used to assess gross sensorimotor function on the 2nd day after surgery, sham-operated rats achieved an average score of 5.37 ± 0.23, SAH-induced rats scored 3.35 ± 0.67, and SAH-induced U0126-treated rats scored 5.00 ± 0.4. CONCLUSIONS The authors demonstrated that experimental SAH induces upregulation of ET(B) and 5-HT(1B) receptors in cerebrovascular smooth muscles and that treatment with the MEK1/2 inhibitor U0126 abolishes this receptor upregulation. They also demonstrated that experimental SAH results in sensorimotor deficits as assessed by a rotating pole test. These deficits were alleviated by U0126 treatment, suggesting that cerebrovascular receptor upregulation is critical for the functional outcome of delayed cerebral ischemia. The authors suggest that inhibition of MEK1/2 may be a promising new SAH treatment strategy.
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Maddahi A, Edvinsson L. Cerebral ischemia induces microvascular pro-inflammatory cytokine expression via the MEK/ERK pathway. J Neuroinflammation 2010; 7:14. [PMID: 20187933 PMCID: PMC2837637 DOI: 10.1186/1742-2094-7-14] [Citation(s) in RCA: 106] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2010] [Accepted: 02/26/2010] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Cerebral ischemia from middle cerebral artery wall (MCA) occlusion results in increased expression of cerebrovascular endothelin and angiotensin receptors and activation of the mitogen-activated protein kinase (MAPK) pathway, as well as reduced local cerebral blood flow and increased levels of pro-inflammatory mediators in the infarct region. In this study, we hypothesised that inhibition of the cerebrovascular inflammatory reaction with a specific MEK1/2 inhibitor (U0126) to block transcription or a combined receptor blockade would reduce infarct size and improve neurological score. METHODS Rats were subjected to a 2-hours middle cerebral artery occlusion (MCAO) followed by reperfusion for 48 hours. Two groups of treated animals were studied; (i) one group received intraperitoneal administration of a specific MEK1/2 inhibitor (U0126) starting at 0, 6, or 12 hours after the occlusion, and (ii) a second group received two specific receptor antagonists (a combination of the angiotensin AT1 receptor inhibitor Candesartan and the endothelin ETA receptor antagonist ZD1611), given immediately after occlusion. The middle cerebral arteries, microvessels and brain tissue were harvested; and the expressions of tumor necrosis factor-alpha (TNF-alpha), interleukin-1ss (IL-1ss), interleukin-6 (IL-6), inducible nitric oxide synthase (iNOS) and phosphorylated ERK1/2, p38 and JNK were analysed using immunohistochemistry. RESULTS We observed an infarct volume of 25 +/- 2% of total brain volume, and reduced neurological function 2 days after MCAO followed by 48 hours of recirculation. Immunohistochemistry revealed enhanced expression of TNF-alpha, IL-1ss, IL-6 and iNOS, as well as elevated levels of phosphorylated ERK1/2 in smooth muscle cells of ischemic MCA and in associated intracerebral microvessels. U0126, given intraperitoneal at zero or 6 hours after the ischemic event, but not at 12 hours, reduced the infarct volume (11.7 +/- 2% and 15 +/- 3%, respectively), normalized pERK1/2, and prevented elevation of the expressions of TNF-alpha IL-1ss, IL-6 and iNOS. Combined inhibition of angiotensin AT1 and endothelin ETA receptors decreased the volume of brain damaged (12.3 +/- 3; P < 0.05) but only slightly reduced MCAO-induced enhanced expression of iNOS and cytokines CONCLUSION The present study shows elevated microvascular expression of TNF-alpha, IL-1ss, IL-6 and iNOS following focal ischemia, and shows that this expression is transcriptionally regulated via the MEK/ERK pathway.
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Affiliation(s)
- Aida Maddahi
- Department of Internal Medicine, Institute of Clinical Sciences, Lund University, Sweden.
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Ansar S, Larsen C, Maddahi A, Edvinsson L. Subarachnoid hemorrhage induces enhanced expression of thromboxane A2 receptors in rat cerebral arteries. Brain Res 2009; 1316:163-72. [PMID: 20026315 DOI: 10.1016/j.brainres.2009.12.031] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2009] [Revised: 12/08/2009] [Accepted: 12/12/2009] [Indexed: 10/20/2022]
Abstract
Cerebral ischemia remains the key cause of morbidity and mortality after subarachnoid hemorrhage (SAH) with a pathogenesis that is still poorly understood. The aim of the present study was to examine the involvement of thromboxane A(2) receptors (TP) in the pathophysiology of cerebral ischemia after SAH in cerebral arteries. SAH was induced in rats by injecting 250 microl of blood into the prechiasmatic cistern. Two days after the SAH, cerebral arteries were harvested and contractile responses to the TP receptor agonist U46619 were investigated with myographs. In addition, the contractile responses were examined after pretreatment with selective TP receptor antagonist GR3219b. The TP receptor RNA and protein levels were analyzed by quantitative real-time PCR and immunohistochemistry, respectively. The global and regional cerebral blood flows (CBFs) were quantified with an autoradiographic technique. SAH resulted in enhanced contractile responses to U46619 as compared to sham. The TP receptor antagonist GR3219b abolished the enhanced contractile responses to U46619 observed after SAH. The TP receptor mRNA level was elevated after SAH as compared to sham. The level of TP receptor protein on the smooth muscle cells (SMCs) was increased in SAH compared to sham. Global and regional CBFs were reduced in SAH as compared to sham. The results demonstrate that SAH results in CBF reduction and this is associated with the enhanced expression of TP receptors in the SMC of cerebral arteries and microvessels.
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Affiliation(s)
- Saema Ansar
- Division of Experimental Vascular Research, Department of Clinical Sciences, Lund University, Sweden.
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Ansar S, Edvinsson L. Equal contribution of increased intracranial pressure and subarachnoid blood to cerebral blood flow reduction and receptor upregulation after subarachnoid hemorrhage. Laboratory investigation. J Neurosurg 2009; 111:978-87. [PMID: 19408972 DOI: 10.3171/2007.3.16738] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
OBJECT Cerebral ischemia remains the key cause of disability and death in the late phase after subarachnoid hemorrhage (SAH), and its pathogenesis is still poorly understood. The purpose of this study was to examine whether the change in intracranial pressure or the extravasated blood causes the late cerebral ischemia and the upregulation of receptors or the cerebral vasoconstriction observed following SAH. METHODS Rats were allocated to 1 of 3 experimental conditions: 1) cisternal injection of 250 microl blood (SAH Group), 2) cisternal injection of 250 microl NaCl (Saline Group), or 3) the same procedure but without fluid injection (Sham Group). Two days after the procedure, the basilar and middle cerebral arteries were harvested, and contractile responses to endothelin (ET)-1 and 5-carboxamidotryptamine (5-CT) were investigated by means of myography. In addition, real-time polymerase chain reaction was used to determine the mRNA levels for ET(A), ET(B), and 5-HT(1) receptors. Regional and global cerebral blood flow (CBF) were quantified by means of an autoradiographic technique. RESULTS Compared with the sham condition, both SAH and saline injection resulted in significantly enhanced contraction of cerebral arteries in response to ET-1 and 5-CT. Regional and global CBF were reduced both in the Saline and SAH groups compared with the Sham Group. The mRNA levels for ET(B) and 5-HT(1B) receptors were upregulated after SAH and saline injection compared with the sham procedure. The effects in all parameters were more pronounced for SAH than for saline injection. CONCLUSIONS This study revealed that both the elevation of intracranial pressure and subarachnoid blood per se contribute approximately equally to the late CBF reductions and receptor upregulation following SAH.
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Affiliation(s)
- Saema Ansar
- Department of Clinical Sciences, Division of Experimental Vascular Research, Lund University, Lund, Sweden.
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Maddahi A, Chen Q, Edvinsson L. Enhanced cerebrovascular expression of matrix metalloproteinase-9 and tissue inhibitor of metalloproteinase-1 via the MEK/ERK pathway during cerebral ischemia in the rat. BMC Neurosci 2009; 10:56. [PMID: 19497125 PMCID: PMC2700114 DOI: 10.1186/1471-2202-10-56] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2008] [Accepted: 06/04/2009] [Indexed: 12/30/2022] Open
Abstract
Background Cerebral ischemia is usually characterized by a reduction in local blood flow and metabolism and by disruption of the blood-brain barrier in the infarct region. The formation of oedema and opening of the blood-brain barrier in stroke is associated with enhanced expression of metalloproteinase-9 (MMP-9) and tissue inhibitor of metalloproteinase-1 (TIMP-1). Results Here, we found an infarct volume of 24.8 ± 2% and a reduced neurological function after two hours of middle cerebral artery occlusion (MCAO), followed by 48 hours of recirculation in rat. Immunocytochemistry and confocal microscopy revealed enhanced expression of MMP-9, TIMP-1, and phosphorylated ERK1/2 in the smooth muscle cells of the ischemic MCA and associated intracerebral microvessels. The specific MEK1/2 inhibitor U0126, given intraperitoneal zero or 6 hours after the ischemic event, reduced the infarct volume significantly (11.8 ± 2% and 14.6 ± 3%, respectively; P < 0.05), improved neurological function, normalized expression of phosphorylated ERK1/2, and reduced expression of MMP-9 and TIMP-1 in the vessel walls. Administration of U0126 12 hours after MCAO did not alter the expression of MMP-9. Immunocytochemistry showed no overlap in expression between MMP-9/TIMP-1 and the astrocyte/glial cell marker GFAP in the vessel walls. Conclusion These data are the first to show that the elevated vascular expression of MMP-9 and TIMP-1, associated with breakdown of the blood-brain barrier following focal ischemia, are transcriptionally regulated via the MEK/ERK pathway.
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Affiliation(s)
- Aida Maddahi
- Department of Clinical Sciences, Division of Experimental Vascular Research, Lund University, Lund, Sweden.
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