1
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Cho YD, Byoun HS, Park KH, Won YI, Lim J. The Impact of Enteral Nimodipine on Endothelial Cell Apoptosis in an Animal Subarachnoid Hemorrhage Model. Neurocrit Care 2024:10.1007/s12028-024-01980-w. [PMID: 38589694 DOI: 10.1007/s12028-024-01980-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Accepted: 03/11/2024] [Indexed: 04/10/2024]
Abstract
BACKGROUND Enteral nimodipine is the most evidence-based and widely used drug for the treatment of delayed cerebral ischemia and is known to have various neuroprotective functions. However, the neuroprotective mechanism of nimodipine still remains unclear, and the effects of nimodipine remain ambiguous. Herein, we studied the effect of enteral nimodipine on endothelial apoptosis after subarachnoid hemorrhage (SAH). METHODS SAH was experimentally introduced in white rabbits (n = 42) that were grouped as follows: enteral nimodipine (SAH-nimodipine group, n = 14), a control that received normal saline (SAH-saline group, n = 13), and a control without hemorrhage (control group, n = 15). On the third day after SAH induction, the brain stem, including the vertebrobasilar vascular system, was extracted. The effects of enteral nimodipine were analyzed by group using histopathologic analysis, including immunohistochemical staining of apoptosis-related proteins (Bcl2 [anti-apoptotic] and Bax [pro-apoptotic]). RESULTS Cytoplasmic vacuolation of smooth muscle cells was observed in two SAH hemorrhagic groups and was more prominent in the SAH-saline group. Endothelial desquamation was observed only in the SAH-saline group. For the basilar artery, expression of Bcl2 and Bax in the SAH-nimodipine group was lower than that in the SAH-saline group, but significant differences were not observed (pBcl2 = 0.311 and pBax = 0.720, respectively). In penetrated arterioles, the expression of Bax in the SAH-nimodipine group was significantly lower than that of the SAH-saline group (p < 0.001). The thickness of the tunica media in the basilar artery was thinner in the SAH-nimodipine group than in the SAH-saline group (p < 0.001). CONCLUSIONS This study suggests that enteral nimodipine may have a neuroprotective function by inhibiting endothelial apoptosis in small arterioles and preventing smooth muscle cell proliferation in large arteries.
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Affiliation(s)
- Young Dae Cho
- Department of Radiology, Seoul National University Hospital and Seoul National University College of Medicine, Seoul, Korea
| | - Hyoung Soo Byoun
- Department of Neurosurgery, Chungnam National University Sejong Hospital, Sejong, South Korea
- Department of Neurosurgery, Chungnam National University School of Medicine, Daejeon, Korea
| | - Kwang Hyon Park
- Department of Neurosurgery, Chungnam National University Sejong Hospital, Sejong, South Korea
| | - Young Il Won
- Department of Neurosurgery, Chungnam National University Sejong Hospital, Sejong, South Korea
| | - Jeongwook Lim
- Department of Neurosurgery, Chungnam National University Sejong Hospital, Sejong, South Korea.
- Department of Neurosurgery, Chungnam National University School of Medicine, Daejeon, Korea.
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2
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Edvinsson L, Krause DN. Switching Off Vascular MAPK Signaling: A Novel Strategy to Prevent Delayed Cerebral Ischemia Following Subarachnoid Hemorrhage. Transl Stroke Res 2024:10.1007/s12975-024-01234-z. [PMID: 38334872 DOI: 10.1007/s12975-024-01234-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2023] [Revised: 01/12/2024] [Accepted: 02/01/2024] [Indexed: 02/10/2024]
Abstract
Patients who initially survive the rupture and repair of a brain aneurysm often take a devastating turn for the worse some days later and die or suffer permanent neurologic deficits. This catastrophic sequela is attributed to a delayed phase of global cerebral ischemia (DCI) following aneurysmal subarachnoid hemorrhage (aSAH), but we lack effective treatment. Here we present our view, based on 20 years of research, that the initial drop in blood flow at the time of rupture triggers genomic responses throughout the brain vasculature that manifest days later as increased vasoconstriction and decreased cerebral blood flow. We propose a novel treatment strategy to prevent DCI by early inhibition of the vascular mitogen-activated protein kinase (MAPK) pathway that triggers expression of vasoconstrictor and inflammatory mediators. We summarize evidence from experimental SAH models showing early treatment with MAPK inhibitors "switches off" these detrimental responses, maintains flow, and improves neurological outcome. This promising therapy is currently being evaluated in clinical trials.
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Affiliation(s)
- Lars Edvinsson
- Division of Experimental Vascular Research, Department of Clinical Sciences, Lund University, Sölvegatan 19, 22100, Lund, Sweden.
- Department of Experimental Research, Glostrup Research Institute, CopenhagenUniversity, Copenhagen, Denmark.
| | - Diana N Krause
- Division of Experimental Vascular Research, Department of Clinical Sciences, Lund University, Sölvegatan 19, 22100, Lund, Sweden
- Department of Pharmaceutical Sciences, SchoolofPharmacy&PharmaceuticalSciences, University of California at Irvine, Irvine, CA, USA
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3
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Shang W, Chang X, Xu Y, Dong B. A Novel Risk-Predicted Nomogram for Perioperative Ischemic Complications of Endovascular Treatment Among Ruptured Anterior Communicating Artery Aneurysms. World Neurosurg 2023; 173:e391-e400. [PMID: 36803690 DOI: 10.1016/j.wneu.2023.02.061] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2022] [Revised: 02/10/2023] [Accepted: 02/11/2023] [Indexed: 02/19/2023]
Abstract
OBJECTIVE To establish and validate a risk prediction model for perioperative ischemic complication (PIC) of endovascular treatment for ruptured anterior communicating artery aneurysms (ACoAAs). METHODS The general clinical and morphologic data, operation schemes, and treatment outcomes of patients with ruptured ACoAAs treated with endovascular treatment in our center from January 2010 to January 2021 were retrospectively analyzed and assigned to primary (359 patients) and validation (67 patients) cohorts. A risk-predicted nomogram for PIC was developed through multivariate logistic regression analysis in the primary cohort. The discrimination ability, calibration accuracy, and clinical usefulness of the established PIC prediction model were evaluated and verified based on the receiver operating characteristic curves, calibration curves, and decision curve analysis in the primary and external validation cohorts, respectively. RESULTS A total of 426 patients were included, 47 of whom had PIC. The multivariate logistic regression analysis showed that hypertension, Fisher grade, A1 conformation, use of stent-assisted coiling, and aneurysm orientation were independent risk factors for PIC. Then, we developed a simple and easy-to-use nomogram to predict PIC. This nomogram has a good diagnostic performance (area under the curve, 0.773; 95% confidence interval, 0.685-0.862) and calibration accuracy; we then further validated this nomogram by external validation cohort and showed an excellent diagnostic performance and calibration accuracy. Besides, the decision curve analysis confirmed the clinical usefulness of the nomogram. CONCLUSIONS A history of hypertension, high preoperative Fisher grade, complete A1 conformation, use of stent-assisted coiling, and aneurysm orientation (pointing upward) are risk factors for PIC for ruptured ACoAAs. This novel nomogram might serve as a potential early warning sign of PIC for ruptured ACoAAs.
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Affiliation(s)
- Wei Shang
- Dalian Medical University, Dalian, Liaoning Province, China
| | - Xiaoting Chang
- Department of Neurology, The Second Affiliated Hospital of Dalian Medical University, Dalian, Liaoning Province, China
| | - Yousong Xu
- Department of Neurosurgery, The First Affiliated Hospital of Dalian Medical University, Dalian, Liaoning Province, China
| | - Bin Dong
- Dalian Medical University, Dalian, Liaoning Province, China.
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4
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Lauzier DC, Jayaraman K, Yuan JY, Diwan D, Vellimana AK, Osbun J, Chatterjee AR, Athiraman U, Dhar R, Zipfel GJ. Early Brain Injury After Subarachnoid Hemorrhage: Incidence and Mechanisms. Stroke 2023; 54:1426-1440. [PMID: 36866673 PMCID: PMC10243167 DOI: 10.1161/strokeaha.122.040072] [Citation(s) in RCA: 39] [Impact Index Per Article: 39.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/04/2023]
Abstract
Aneurysmal subarachnoid hemorrhage is a devastating condition causing significant morbidity and mortality. While outcomes from subarachnoid hemorrhage have improved in recent years, there continues to be significant interest in identifying therapeutic targets for this disease. In particular, there has been a shift in emphasis toward secondary brain injury that develops in the first 72 hours after subarachnoid hemorrhage. This time period of interest is referred to as the early brain injury period and comprises processes including microcirculatory dysfunction, blood-brain-barrier breakdown, neuroinflammation, cerebral edema, oxidative cascades, and neuronal death. Advances in our understanding of the mechanisms defining the early brain injury period have been accompanied by improved imaging and nonimaging biomarkers for identifying early brain injury, leading to the recognition of an elevated clinical incidence of early brain injury compared with prior estimates. With the frequency, impact, and mechanisms of early brain injury better defined, there is a need to review the literature in this area to guide preclinical and clinical study.
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Affiliation(s)
- David C. Lauzier
- Department of Neurological Surgery, Washington University School of Medicine
| | - Keshav Jayaraman
- Department of Neurological Surgery, Washington University School of Medicine
| | - Jane Y. Yuan
- Department of Neurological Surgery, Washington University School of Medicine
| | - Deepti Diwan
- Department of Neurological Surgery, Washington University School of Medicine
| | - Ananth K. Vellimana
- Department of Neurological Surgery, Washington University School of Medicine
- Department of Neurology, Washington University School of Medicine
- Mallinckrodt Institute of Radiology, Washington University School of Medicine
| | - Joshua Osbun
- Department of Neurological Surgery, Washington University School of Medicine
- Department of Neurology, Washington University School of Medicine
- Mallinckrodt Institute of Radiology, Washington University School of Medicine
| | - Arindam R. Chatterjee
- Department of Neurological Surgery, Washington University School of Medicine
- Department of Neurology, Washington University School of Medicine
- Mallinckrodt Institute of Radiology, Washington University School of Medicine
| | | | - Rajat Dhar
- Department of Neurology, Washington University School of Medicine
| | - Gregory J. Zipfel
- Department of Neurological Surgery, Washington University School of Medicine
- Department of Neurology, Washington University School of Medicine
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5
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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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6
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Malinova V, Bleuel K, Stadelmann C, Iliev B, Tsogkas I, Psychogios MN, Rohde V, Mielke D. The impact of transcranial direct current stimulation on cerebral vasospasm in a rat model of subarachnoid hemorrhage. J Cereb Blood Flow Metab 2021; 41:2000-2009. [PMID: 33504272 PMCID: PMC8323336 DOI: 10.1177/0271678x21990130] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Transcranial direct current stimulation (tDCS) has been shown to induce changes in cortical excitability and perfusion in a rat ischemic stroke model. Since perfusion disturbances are a common phenomenon, not only in ischemic but also in hemorrhagic stroke, tDCS might have a possible beneficial effect on cerebral perfusion in hemorrhagic stroke as well. We applied tDCS in a rat model of subarachnoid hemorrhage (SAH) and evaluated its impact on vasospasm. SAH was induced using the double-hemorrhage rat model. TDCS was applied on day 3 and 4. For vasospasm assessment magnetic resonance angiography was performed on day 1, day 2 and day 5. A total of 147 rats were operated, whereat 72 rats died before day 5 and 75 rats survived the whole experiment and could be analyzed. The cathodal group consisted of 26 rats, the anodal group included 24 rats. Thirteen rats served as controls without tDCS, and twelve rats underwent a sham operation. The cathodal group revealed the lowest incidence of new vasospasm on day 5 (p = 0.01), and the lowest mean number of vasospastic vessels per rat (p = 0.02). TDCS influences the vasospasm incidence in an SAH-model in rats, where cathodal-tDCS was associated with a lower vasospasm incidence and severity.
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Affiliation(s)
- Vesna Malinova
- Department of Neurosurgery, University Medical Center Göttingen, Göttingen, Germany
| | - Kim Bleuel
- Department of Neurosurgery, University Medical Center Göttingen, Göttingen, Germany
| | - Christine Stadelmann
- Department of Neuropathology, University Medical Center Göttingen, Göttingen, Germany
| | - Bogdan Iliev
- Department of Neurosurgery, University Medical Center Göttingen, Göttingen, Germany
| | - Ioannis Tsogkas
- Department of Neuroradiology, Clinic of Radiology and Nuclear Medicine, University Medicine Basel, Basel, Switzerland.,Department of Neuroradiology, University Medical Center Göttingen, Göttingen, Germany
| | - Marios N Psychogios
- Department of Neuroradiology, Clinic of Radiology and Nuclear Medicine, University Medicine Basel, Basel, Switzerland.,Department of Neuroradiology, University Medical Center Göttingen, Göttingen, Germany
| | - Veit Rohde
- Department of Neurosurgery, University Medical Center Göttingen, Göttingen, Germany
| | - Dorothee Mielke
- Department of Neurosurgery, University Medical Center Göttingen, Göttingen, Germany
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7
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Lidington D, Wan H, Bolz SS. Cerebral Autoregulation in Subarachnoid Hemorrhage. Front Neurol 2021; 12:688362. [PMID: 34367053 PMCID: PMC8342764 DOI: 10.3389/fneur.2021.688362] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Accepted: 06/25/2021] [Indexed: 12/28/2022] Open
Abstract
Subarachnoid hemorrhage (SAH) is a devastating stroke subtype with a high rate of mortality and morbidity. The poor clinical outcome can be attributed to the biphasic course of the disease: even if the patient survives the initial bleeding emergency, delayed cerebral ischemia (DCI) frequently follows within 2 weeks time and levies additional serious brain injury. Current therapeutic interventions do not specifically target the microvascular dysfunction underlying the ischemic event and as a consequence, provide only modest improvement in clinical outcome. SAH perturbs an extensive number of microvascular processes, including the “automated” control of cerebral perfusion, termed “cerebral autoregulation.” Recent evidence suggests that disrupted cerebral autoregulation is an important aspect of SAH-induced brain injury. This review presents the key clinical aspects of cerebral autoregulation and its disruption in SAH: it provides a mechanistic overview of cerebral autoregulation, describes current clinical methods for measuring autoregulation in SAH patients and reviews current and emerging therapeutic options for SAH patients. Recent advancements should fuel optimism that microvascular dysfunction and cerebral autoregulation can be rectified in SAH patients.
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Affiliation(s)
- Darcy Lidington
- Department of Physiology, University of Toronto, Toronto, ON, Canada.,Toronto Centre for Microvascular Medicine at the Ted Rogers Centre for Heart Research Translational Biology and Engineering Program, University of Toronto, Toronto, ON, Canada
| | - Hoyee Wan
- Department of Physiology, University of Toronto, Toronto, ON, Canada.,Toronto Centre for Microvascular Medicine at the Ted Rogers Centre for Heart Research Translational Biology and Engineering Program, University of Toronto, Toronto, ON, Canada
| | - Steffen-Sebastian Bolz
- Department of Physiology, University of Toronto, Toronto, ON, Canada.,Toronto Centre for Microvascular Medicine at the Ted Rogers Centre for Heart Research Translational Biology and Engineering Program, University of Toronto, Toronto, ON, Canada.,Heart & Stroke/Richard Lewar Centre of Excellence for Cardiovascular Research, University of Toronto, Toronto, ON, Canada
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8
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Koide M, Ferris HR, Nelson MT, Wellman GC. Impaired Cerebral Autoregulation After Subarachnoid Hemorrhage: A Quantitative Assessment Using a Mouse Model. Front Physiol 2021; 12:688468. [PMID: 34168571 PMCID: PMC8218876 DOI: 10.3389/fphys.2021.688468] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Accepted: 04/26/2021] [Indexed: 01/01/2023] Open
Abstract
Subarachnoid hemorrhage (SAH) is a common form of hemorrhagic stroke associated with high rates of mortality and severe disability. SAH patients often develop severe neurological deficits days after ictus, events attributed to a phenomenon referred to as delayed cerebral ischemia (DCI). Recent studies indicate that SAH-induced DCI results from a multitude of cerebral circulatory disturbances including cerebral autoregulation malfunction. Cerebral autoregulation incorporates the influence of blood pressure (BP) on arterial diameter in the homeostatic regulation of cerebral blood flow (CBF), which is necessary for maintaining constant brain perfusion during physiological swings in systemic BP. In this study, we quantitatively examined the impact of SAH on cerebral autoregulation using a mouse endovascular perforation model and a newly developed approach combining absolute and relative CBF measurements. This method enables a direct quantitative comparison of cerebral autoregulation between individual animals (e.g., SAH vs. control or sham-operated mice), which cannot be done solely using relative CBF changes by laser Doppler flowmetry. Here, absolute CBF was measured via injection of fluorescent microspheres at a baseline BP. In separate groups of animals, in vivo laser Doppler flowmetry was used to measure relative CBF changes over a range of BP using phlebotomy and the pressor phenylephrine to lower and raise BP, respectively. Absolute CBF measurements from microspheres were then used to calibrate laser Doppler measurements to calculate the relationship between CBF and BP, i.e., “cerebral autoregulation curves.” Un-operated and sham-operated groups exhibited similar cerebral autoregulatory curves, showing comparable levels of relatively constant CBF over a range of BP from ~80 mmHg to ~130 mmHg. In contrast, SAH animals exhibited a narrower autoregulatory range of BP, which was primarily due to a decrease in the upper limit of BP whereby cerebral autoregulation was maintained. Importantly, SAH animals also exhibited a marked decrease in CBF throughout the entire range of BP. In sum, this study provides evidence of the dramatic reduction in cortical CBF and the diminished range of autoregulation after SAH. Furthermore, this novel methodology should pave the way for future studies examining pathological mechanisms and/or therapeutic strategies targeting impaired cerebral autoregulation, a pathology common to many cardiovascular and cerebrovascular disorders.
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Affiliation(s)
- Masayo Koide
- Department of Pharmacology, Larner College of Medicine, University of Vermont, Burlington, VT, United States.,Vermont Center for Cardiovascular and Brain Health, Larner College of Medicine, University of Vermont, Burlington, VT, United States
| | - Hannah R Ferris
- Department of Pharmacology, Larner College of Medicine, University of Vermont, Burlington, VT, United States
| | - Mark T Nelson
- Department of Pharmacology, Larner College of Medicine, University of Vermont, Burlington, VT, United States.,Vermont Center for Cardiovascular and Brain Health, Larner College of Medicine, University of Vermont, Burlington, VT, United States.,Division of Cardiovascular Sciences, University of Manchester, Manchester, United Kingdom
| | - George C Wellman
- Department of Pharmacology, Larner College of Medicine, University of Vermont, Burlington, VT, United States
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9
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Failed Neuroprotection of Combined Inhibition of L-Type and ASIC1a Calcium Channels with Nimodipine and Amiloride. Int J Mol Sci 2020; 21:ijms21238921. [PMID: 33255506 PMCID: PMC7727815 DOI: 10.3390/ijms21238921] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2020] [Revised: 11/19/2020] [Accepted: 11/20/2020] [Indexed: 01/15/2023] Open
Abstract
Effective pharmacological neuroprotection is one of the most desired aims in modern medicine. We postulated that a combination of two clinically used drugs-nimodipine (L-Type voltage-gated calcium channel blocker) and amiloride (acid-sensing ion channel inhibitor)-might act synergistically in an experimental model of ischaemia, targeting the intracellular rise in calcium as a pathway in neuronal cell death. We used organotypic hippocampal slices of mice pups and a well-established regimen of oxygen-glucose deprivation (OGD) to assess a possible neuroprotective effect. Neither nimodipine (at 10 or 20 µM) alone or in combination with amiloride (at 100 µM) showed any amelioration. Dissolved at 2.0 Vol.% dimethyl-sulfoxide (DMSO), the combination of both components even increased cell damage (p = 0.0001), an effect not observed with amiloride alone. We conclude that neither amiloride nor nimodipine do offer neuroprotection in an in vitro ischaemia model. On a technical note, the use of DMSO should be carefully evaluated in neuroprotective experiments, since it possibly alters cell damage.
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10
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Geraghty JR, Davis JL, Testai FD. Neuroinflammation and Microvascular Dysfunction After Experimental Subarachnoid Hemorrhage: Emerging Components of Early Brain Injury Related to Outcome. Neurocrit Care 2019; 31:373-389. [PMID: 31012056 PMCID: PMC6759381 DOI: 10.1007/s12028-019-00710-x] [Citation(s) in RCA: 78] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Aneurysmal subarachnoid hemorrhage has a high mortality rate and, for those who survive this devastating injury, can lead to lifelong impairment. Clinical trials have demonstrated that cerebral vasospasm of larger extraparenchymal vessels is not the sole contributor to neurological outcome. Recently, the focus of intense investigation has turned to mechanisms of early brain injury that may play a larger role in outcome, including neuroinflammation and microvascular dysfunction. Extravasated blood after aneurysm rupture results in a robust inflammatory response characterized by activation of microglia, upregulation of cellular adhesion molecules, recruitment of peripheral immune cells, as well as impaired neurovascular coupling, disruption of the blood-brain barrier, and imbalances in endogenous vasodilators and vasoconstrictors. Each of these phenomena is either directly or indirectly associated with neuronal death and brain injury. Here, we review recent studies investigating these various mechanisms in experimental models of subarachnoid hemorrhage with special emphasis on neuroinflammation and its effect on microvascular dysfunction. We discuss the various therapeutic targets that have risen from these mechanistic studies and suggest the utility of a multi-targeted approach to preventing delayed injury and improving outcome after subarachnoid hemorrhage.
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Affiliation(s)
- Joseph R Geraghty
- Department of Neurology and Rehabilitation, College of Medicine, University of Illinois at Chicago, 912 S. Wood St. Suite 174N, Chicago, IL, 60612, USA.
- Medical Scientist Training Program, University of Illinois at Chicago, Chicago, IL, USA.
| | - Joseph L Davis
- Department of Neurology and Rehabilitation, College of Medicine, University of Illinois at Chicago, 912 S. Wood St. Suite 174N, Chicago, IL, 60612, USA
| | - Fernando D Testai
- Department of Neurology and Rehabilitation, College of Medicine, University of Illinois at Chicago, 912 S. Wood St. Suite 174N, Chicago, IL, 60612, USA
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11
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Griffiths S, Clark J, Adamides AA, Ziogas J. The role of haptoglobin and hemopexin in the prevention of delayed cerebral ischaemia after aneurysmal subarachnoid haemorrhage: a review of current literature. Neurosurg Rev 2019; 43:1273-1288. [PMID: 31493061 DOI: 10.1007/s10143-019-01169-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2019] [Revised: 07/23/2019] [Accepted: 08/26/2019] [Indexed: 01/01/2023]
Abstract
Delayed cerebral ischaemia (DCI) after aneurysmal subarachnoid haemorrhage (aSAH) is a major cause of mortality and morbidity. The pathophysiology of DCI after aSAH is thought to involve toxic mediators released from lysis of red blood cells within the subarachnoid space, including free haemoglobin and haem. Haptoglobin and hemopexin are endogenously produced acute phase proteins that are involved in the clearance of these toxic mediators. The aim of this review is to investigate the pathophysiological mechanisms involved in DCI and the role of both endogenous as well as exogenously administered haptoglobin and hemopexin in the prevention of DCI.
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Affiliation(s)
- Sean Griffiths
- Department of Neurosurgery, Royal Melbourne Hospital, 300 Grattan St, Parkville, 3050, Australia. .,Western Hospital, 160 Gordon St, Footscray, 3011, Australia.
| | - Jeremy Clark
- Department of Neurosurgery, Royal Melbourne Hospital, 300 Grattan St, Parkville, 3050, Australia
| | - Alexios A Adamides
- Department of Neurosurgery, Royal Melbourne Hospital, 300 Grattan St, Parkville, 3050, Australia
| | - James Ziogas
- Department of Pharmacology and Therapeutics, University of Melbourne, Parkville, 3010, Australia
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12
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Koide M, Moshkforoush A, Tsoukias NM, Hill-Eubanks DC, Wellman GC, Nelson MT, Dabertrand F. The yin and yang of K V channels in cerebral small vessel pathologies. Microcirculation 2018; 25. [PMID: 29247493 DOI: 10.1111/micc.12436] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2017] [Accepted: 12/08/2017] [Indexed: 12/14/2022]
Abstract
Cerebral SVDs encompass a group of genetic and sporadic pathological processes leading to brain lesions, cognitive decline, and stroke. There is no specific treatment for SVDs, which progress silently for years before becoming clinically symptomatic. Here, we examine parallels in the functional defects of PAs in CADASIL, a monogenic form of SVD, and in response to SAH, a common type of hemorrhagic stroke that also targets the brain microvasculature. Both animal models exhibit dysregulation of the voltage-gated potassium channel, KV 1, in arteriolar myocytes, an impairment that compromises responses to vasoactive stimuli and impacts CBF autoregulation and local dilatory responses to neuronal activity (NVC). However, the extent to which this channelopathy-like defect ultimately contributes to these pathologies is unknown. Combining experimental data with computational modeling, we describe the role of KV 1 channels in the regulation of myocyte membrane potential at rest and during the modest increase in extracellular potassium associated with NVC. We conclude that PA resting membrane potential and myogenic tone depend strongly on KV 1.2/1.5 channel density, and that reciprocal changes in KV channel density in CADASIL and SAH produce opposite effects on extracellular potassium-mediated dilation during NVC.
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Affiliation(s)
- Masayo Koide
- Department of Pharmacology, University of Vermont, Burlington, VT, USA
| | - Arash Moshkforoush
- Department of Biomedical Engineering, Florida International University, Miami, FL, USA
| | - Nikolaos M Tsoukias
- Department of Biomedical Engineering, Florida International University, Miami, FL, USA
| | | | - George C Wellman
- Department of Pharmacology, University of Vermont, Burlington, VT, USA
| | - Mark T Nelson
- Department of Pharmacology, University of Vermont, Burlington, VT, USA.,Institute of Cardiovascular Sciences, University of Manchester, Manchester, UK
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Lidington D, Kroetsch JT, Bolz SS. Cerebral artery myogenic reactivity: The next frontier in developing effective interventions for subarachnoid hemorrhage. J Cereb Blood Flow Metab 2018; 38:17-37. [PMID: 29135346 PMCID: PMC5757446 DOI: 10.1177/0271678x17742548] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Aneurysmal subarachnoid hemorrhage (SAH) is a devastating cerebral event that kills or debilitates the majority of those afflicted. The blood that spills into the subarachnoid space stimulates profound cerebral artery vasoconstriction and consequently, cerebral ischemia. Thus, once the initial bleeding in SAH is appropriately managed, the clinical focus shifts to maintaining/improving cerebral perfusion. However, current therapeutic interventions largely fail to improve clinical outcome, because they do not effectively restore normal cerebral artery function. This review discusses emerging evidence that perturbed cerebrovascular "myogenic reactivity," a crucial microvascular process that potently dictates cerebral perfusion, is the critical element underlying cerebral ischemia in SAH. In fact, the myogenic mechanism could be the reason why many therapeutic interventions, including "Triple H" therapy, fail to deliver benefit to patients. Understanding the molecular basis for myogenic reactivity changes in SAH holds the key to develop more effective therapeutic interventions; indeed, promising recent advancements fuel optimism that vascular dysfunction in SAH can be corrected to improve outcome.
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Affiliation(s)
- Darcy Lidington
- 1 Department of Physiology, University of Toronto, Toronto, Canada.,2 Toronto Centre for Microvascular Medicine at TBEP, University of Toronto, Toronto, Canada
| | - Jeffrey T Kroetsch
- 1 Department of Physiology, University of Toronto, Toronto, Canada.,2 Toronto Centre for Microvascular Medicine at TBEP, University of Toronto, Toronto, Canada
| | - Steffen-Sebastian Bolz
- 1 Department of Physiology, University of Toronto, Toronto, Canada.,2 Toronto Centre for Microvascular Medicine at TBEP, University of Toronto, Toronto, Canada.,3 Heart & Stroke/Richard Lewar Centre of Excellence for Cardiovascular Research, University of Toronto, Toronto, Canada
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Delayed Cerebral Ischemia after Subarachnoid Hemorrhage: Beyond Vasospasm and Towards a Multifactorial Pathophysiology. Curr Atheroscler Rep 2017; 19:50. [PMID: 29063300 DOI: 10.1007/s11883-017-0690-x] [Citation(s) in RCA: 182] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
PURPOSE OF REVIEW Delayed cerebral ischemia (DCI) is common after subarachnoid hemorrhage (SAH) and represents a significant cause of poor functional outcome. DCI was mainly thought to be caused by cerebral vasospasm; however, recent clinical trials have been unable to confirm this hypothesis. Studies in humans and animal models have since supported the notion of a multifactorial pathophysiology of DCI. This review summarizes some of the main mechanisms under investigation including cerebral vascular dysregulation, microthrombosis, cortical spreading depolarizations, and neuroinflammation. RECENT FINDINGS Recent guidelines have differentiated between DCI and angiographic vasospasm and have highlighted roles of the microvasculature, coagulation and fibrinolytic systems, cortical spreading depressions, and the contribution of the immune system to DCI. Many therapeutic interventions are underway in both preclinical and clinical studies to target these novel mechanisms as well as studies connecting these mechanisms to one another. Clinical trials to date have been largely unsuccessful at preventing or treating DCI after SAH. The only successful pharmacologic intervention is the calcium channel antagonist, nimodipine. Recent studies have provided evidence that cerebral vasospasm is not the sole contributor to DCI and that additional mechanisms may play equal if not more important roles.
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