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Wang Z, Zhao Y, Hou Y, Tang G, Zhang R, Yang Y, Yan X, Fan K. A Thrombin-Activated Peptide-Templated Nanozyme for Remedying Ischemic Stroke via Thrombolytic and Neuroprotective Actions. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2024; 36:e2210144. [PMID: 36730098 DOI: 10.1002/adma.202210144] [Citation(s) in RCA: 20] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2022] [Revised: 12/29/2022] [Indexed: 06/18/2023]
Abstract
Ischemic stroke (IS) is one of the most common causes of disability and death. Thrombolysis and neuroprotection are two current major therapeutic strategies to overcome ischemic and reperfusion damage. In this work, a novel peptide-templated manganese dioxide nanozyme (PNzyme/MnO2 ) is designed that integrates the thrombolytic activity of functional peptides with the reactive oxygen species scavenging ability of nanozymes. Through self-assembled polypeptides that contain multiple functional motifs, the novel peptide-templated nanozyme is able to bind fibrin in the thrombus, cross the blood-brain barrier, and finally accumulate in the ischemic neuronal tissues, where the thrombolytic motif is "switched-on" by the action of thrombin. In mice and rat IS models, the PNzyme/MnO2 prolongs the blood-circulation time and exhibits strong thrombolytic action, and reduces the ischemic damages in brain tissues. Moreover, this peptide-templated nanozyme also effectively inhibits the activation of astrocytes and the secretion of proinflammatory cytokines. These data indicate that the rationally designed PNzyme/MnO2 nanozyme exerts both thrombolytic and neuroprotective actions. Giving its long half-life in the blood and ability to target brain thrombi, the biocompatible nanozyme may serve as a novel therapeutic agent to improve the efficacy and prevent secondary thrombosis during the treatment of IS.
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Affiliation(s)
- Zhuoran Wang
- CAS Engineering Laboratory for Nanozyme, Key Laboratory of Protein and Peptide Pharmaceutical, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, P. R. China
| | - Yue Zhao
- CAS Engineering Laboratory for Nanozyme, Key Laboratory of Protein and Peptide Pharmaceutical, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, P. R. China
- University of Chinese Academy of Sciences, Beijing, 101408, P. R. China
| | - Yaxin Hou
- CAS Engineering Laboratory for Nanozyme, Key Laboratory of Protein and Peptide Pharmaceutical, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, P. R. China
- University of Chinese Academy of Sciences, Beijing, 101408, P. R. China
| | - Guoheng Tang
- CAS Engineering Laboratory for Nanozyme, Key Laboratory of Protein and Peptide Pharmaceutical, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, P. R. China
- University of Chinese Academy of Sciences, Beijing, 101408, P. R. China
| | - Ruofei Zhang
- CAS Engineering Laboratory for Nanozyme, Key Laboratory of Protein and Peptide Pharmaceutical, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, P. R. China
| | - Yili Yang
- China Regional Research Centre, International Centre of Genetic Engineering and Biotechnology, Taizhou, 212200, P. R. China
| | - Xiyun Yan
- CAS Engineering Laboratory for Nanozyme, Key Laboratory of Protein and Peptide Pharmaceutical, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, P. R. China
- University of Chinese Academy of Sciences, Beijing, 101408, P. R. China
- Nanozyme Medical Center, School of Basic Medical Sciences, Zhengzhou University, Zhengzhou, 450001, P. R. China
| | - Kelong Fan
- CAS Engineering Laboratory for Nanozyme, Key Laboratory of Protein and Peptide Pharmaceutical, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, P. R. China
- University of Chinese Academy of Sciences, Beijing, 101408, P. R. China
- Nanozyme Medical Center, School of Basic Medical Sciences, Zhengzhou University, Zhengzhou, 450001, P. R. China
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Luger S, Koerbel K, Martinez Oeckel A, Schneider H, Maurer CJ, Hintereder G, Wagner M, Hattingen E, Foerch C. Role of S100B Serum Concentration as a Surrogate Outcome Parameter After Mechanical Thrombectomy. Neurology 2021; 97:e2185-e2194. [PMID: 34635559 PMCID: PMC8641970 DOI: 10.1212/wnl.0000000000012918] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2021] [Accepted: 09/20/2021] [Indexed: 11/24/2022] Open
Abstract
Background and Objectives To establish serum concentration of protein S100B as an objective biomarker surrogate for astroglial tissue damage after mechanical thrombectomy in patients with acute ischemic stroke. Methods This prospective 2-center study recruited patients with acute middle cerebral artery infarctions caused by large vessel occlusion treated with mechanical thrombectomy. Blood samples were collected at day 2 after intervention and analyzed for S100B serum concentrations using ELISA techniques. Infarct size was determined on follow-up brain imaging and functional outcome according to modified Rankin Scale (mRS) was assessed at 90 days. Results A total of 171 patients were included (mean age ± SD: 70 ± 14 years, 42% female). S100B levels correlated with infarct size. Median S100B concentrations at day 2 after intervention were lower in patients with favorable outcome (mRS score 0–1) at 90 days compared to patients with unfavorable outcome (mRS score 2–6) (median 0.10 µg/L [interquartile range 0.07–0.14] vs 0.20 µg/L [0.11–0.48], p < 0.001). Younger age (odds ratio [OR] 1.120 [confidence interval (CI) 1.068–1.174]; p < 0.001), lower National Institutes of Health Stroke Scale score 24 hours after symptom onset (OR 1.232 [CI 1.106–1.372]; p < 0.001), and lower S100B serum concentrations (OR 1.364 [CI 1.105–1.683]; p = 0.004) were independently associated with a favorable outcome. S100B was able to eliminate the lateralization bias associated with the use of mRS for functional outcome assessment at 90 days after stroke. Discussion S100B serum concentrations after mechanical thrombectomy indicate the extent of ischemic tissue damage. This can be assessed rapidly, independent of brain imaging and clinical outcome scales. Following prospective validation in further studies, this may provide an objective surrogate outcome measure both in clinical routine and interventional trials. Classification of Evidence This study provides Class I evidence that S100B 2 days following mechanical thrombectomy for acute ischemic stroke accurately distinguishes favorable from unfavorable functional outcome.
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Affiliation(s)
- Sebastian Luger
- From the Department of Neurology (S.L., K.K., A.M.O., C.F.), Central Laboratory (G.H.), and Institute of Neuroradiology (M.W., E.H.), University Hospital Frankfurt / Goethe University Frankfurt; and Departments of Neurology (H.S.) and Diagnostic and Interventional Radiology and Neuroradiology (C.J.M.), University Hospital Augsburg, Germany.
| | - Kimberly Koerbel
- From the Department of Neurology (S.L., K.K., A.M.O., C.F.), Central Laboratory (G.H.), and Institute of Neuroradiology (M.W., E.H.), University Hospital Frankfurt / Goethe University Frankfurt; and Departments of Neurology (H.S.) and Diagnostic and Interventional Radiology and Neuroradiology (C.J.M.), University Hospital Augsburg, Germany
| | - Ariane Martinez Oeckel
- From the Department of Neurology (S.L., K.K., A.M.O., C.F.), Central Laboratory (G.H.), and Institute of Neuroradiology (M.W., E.H.), University Hospital Frankfurt / Goethe University Frankfurt; and Departments of Neurology (H.S.) and Diagnostic and Interventional Radiology and Neuroradiology (C.J.M.), University Hospital Augsburg, Germany
| | - Hauke Schneider
- From the Department of Neurology (S.L., K.K., A.M.O., C.F.), Central Laboratory (G.H.), and Institute of Neuroradiology (M.W., E.H.), University Hospital Frankfurt / Goethe University Frankfurt; and Departments of Neurology (H.S.) and Diagnostic and Interventional Radiology and Neuroradiology (C.J.M.), University Hospital Augsburg, Germany
| | - Christoph J Maurer
- From the Department of Neurology (S.L., K.K., A.M.O., C.F.), Central Laboratory (G.H.), and Institute of Neuroradiology (M.W., E.H.), University Hospital Frankfurt / Goethe University Frankfurt; and Departments of Neurology (H.S.) and Diagnostic and Interventional Radiology and Neuroradiology (C.J.M.), University Hospital Augsburg, Germany
| | - Gudrun Hintereder
- From the Department of Neurology (S.L., K.K., A.M.O., C.F.), Central Laboratory (G.H.), and Institute of Neuroradiology (M.W., E.H.), University Hospital Frankfurt / Goethe University Frankfurt; and Departments of Neurology (H.S.) and Diagnostic and Interventional Radiology and Neuroradiology (C.J.M.), University Hospital Augsburg, Germany
| | - Marlies Wagner
- From the Department of Neurology (S.L., K.K., A.M.O., C.F.), Central Laboratory (G.H.), and Institute of Neuroradiology (M.W., E.H.), University Hospital Frankfurt / Goethe University Frankfurt; and Departments of Neurology (H.S.) and Diagnostic and Interventional Radiology and Neuroradiology (C.J.M.), University Hospital Augsburg, Germany
| | - Elke Hattingen
- From the Department of Neurology (S.L., K.K., A.M.O., C.F.), Central Laboratory (G.H.), and Institute of Neuroradiology (M.W., E.H.), University Hospital Frankfurt / Goethe University Frankfurt; and Departments of Neurology (H.S.) and Diagnostic and Interventional Radiology and Neuroradiology (C.J.M.), University Hospital Augsburg, Germany
| | - Christian Foerch
- From the Department of Neurology (S.L., K.K., A.M.O., C.F.), Central Laboratory (G.H.), and Institute of Neuroradiology (M.W., E.H.), University Hospital Frankfurt / Goethe University Frankfurt; and Departments of Neurology (H.S.) and Diagnostic and Interventional Radiology and Neuroradiology (C.J.M.), University Hospital Augsburg, Germany
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Ngiam NJH, Tan BYQ, Sia CH, Chan BPL, Anil G, Cunli Y, Holmin S, Anderssen T, Poh KK, Yeo LLL, Sharma VK. Significant aortic stenosis associated with poorer functional outcomes in patients with acute ischaemic stroke undergoing endovascular therapy. Interv Neuroradiol 2020; 26:793-799. [PMID: 32340516 PMCID: PMC7724604 DOI: 10.1177/1591019920920988] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Revised: 03/15/2020] [Accepted: 03/30/2020] [Indexed: 04/05/2024] Open
Abstract
BACKGROUND AND AIM Bi-directional feedback mechanisms exist between the heart and brain, which have been implicated in heart failure. We postulate that aortic stenosis may alter cerebral haemodynamics and influence functional outcomes after endovascular thrombectomy for acute ischaemic stroke. We compared clinical characteristics, echocardiographic profile and outcomes in patients with or without aortic stenosis that underwent endovascular thrombectomy for large vessel occlusion acute ischaemic stroke. METHODS Consecutive acute ischaemic stroke patients with anterior and posterior circulation large vessel occlusion (internal carotid artery, middle cerebral artery and basilar artery) who underwent endovascular thrombectomy were studied. Patients were divided into those with significant aortic stenosis (aortic valve area <1.5 cm2) and without. Univariate and multivariate analyses were employed to compare and determine predictors of functional outcomes measured by modified Rankin scale at three months. RESULTS We identified 26 (8.5%) patients with significant aortic stenosis. These patients were older (median age 76 (interquartile range 68-84) vs. 67 (interquartile range 56-75) years, p = 0.001), but similar in terms of medical comorbidities and echocardiographic profile. Rates of successful recanalisation (73.1% vs. 78.0%), symptomatic intracranial haemorrhage (7.7% and 7.9%) and mortality (11.5% vs. 12.6%) were similar. Significant aortic stenosis was independently associated with poorer functional outcome (modified Rankin scale >2) at three months (adjusted odds ratio 2.7, 95% confidence interval 1.1-7.5, p = 0.048), after adjusting for age, door-to-puncture times, stroke severity and rates of successful recanalisation. CONCLUSION In acute ischaemic stroke patients managed with endovascular thrombectomy, significant aortic stenosis is associated with poor functional outcome despite comparable recanalisation rates. Larger cohort studies are needed to explore this relationship further.
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Affiliation(s)
- Nicholas JH Ngiam
- Division of Neurology, Department of Medicine, National
University Health System, Singapore, Singapore
| | - Benjamin YQ Tan
- Division of Neurology, Department of Medicine, National
University Health System, Singapore, Singapore
- Yong Loo Lin School of Medicine, National University of
Singapore, Singapore, Singapore
| | - Ching-Hui Sia
- Yong Loo Lin School of Medicine, National University of
Singapore, Singapore, Singapore
- Department of Cardiology, National University Heart Centre
Singapore, National University Health System, Singapore, Singapore
| | - Bernard PL Chan
- Division of Neurology, Department of Medicine, National
University Health System, Singapore, Singapore
| | - Gopinathan Anil
- Yong Loo Lin School of Medicine, National University of
Singapore, Singapore, Singapore
- Division of Interventional Radiology, Department of Diagnostic
Imaging, National University Health System, Singapore, Singapore
| | - Yang Cunli
- Division of Interventional Radiology, Department of Diagnostic
Imaging, National University Health System, Singapore, Singapore
| | - Staffan Holmin
- Deparment of Neuroradiology, Karolinska University Hospital and
Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Tommy Anderssen
- Deparment of Neuroradiology, Karolinska University Hospital and
Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Kian-Keong Poh
- Yong Loo Lin School of Medicine, National University of
Singapore, Singapore, Singapore
- Department of Cardiology, National University Heart Centre
Singapore, National University Health System, Singapore, Singapore
| | - Leonard LL Yeo
- Division of Neurology, Department of Medicine, National
University Health System, Singapore, Singapore
- Yong Loo Lin School of Medicine, National University of
Singapore, Singapore, Singapore
| | - Vijay K Sharma
- Division of Neurology, Department of Medicine, National
University Health System, Singapore, Singapore
- Yong Loo Lin School of Medicine, National University of
Singapore, Singapore, Singapore
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Wang J, Lin X, Mu Z, Shen F, Zhang L, Xie Q, Tang Y, Wang Y, Zhang Z, Yang GY. Rapamycin Increases Collateral Circulation in Rodent Brain after Focal Ischemia as detected by Multiple Modality Dynamic Imaging. Am J Cancer Res 2019; 9:4923-4934. [PMID: 31410191 PMCID: PMC6691378 DOI: 10.7150/thno.32676] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2018] [Accepted: 03/17/2019] [Indexed: 01/09/2023] Open
Abstract
Rationale: Brain collaterals contribute to improving ischemic stroke outcomes. However, dynamic and timely investigations of collateral blood flow and collateral restoration in whole brains of living animals have rarely been reported. Methods: Using multiple modalities of imaging, including synchrotron radiation angiography, laser speckle imaging, and micro-CT imaging, we dynamically explored collateral circulation throughout the whole brain in the rodent middle cerebral artery occlusion model. Results: We demonstrated that compared to control animals, 4 neocollaterals gradually formed between the intra- and extra-arteries in the skull base of model animals after occlusion (p<0.05). Two main collaterals were critical to the supply of blood from the posterior to the middle cerebral artery territory in the deep brain (p<0.05). Abundant small vessel and capillary anastomoses were detected on the surface of the cortex between the posterior and middle cerebral artery and between the anterior and middle cerebral artery (p<0.05). Collateral perfusion occurred immediately (≈15 min) and was maintained for up to 14 days after occlusion. Further study revealed that administration of rapamycin at 15 min after MCAO dilated the existing collateral vessels and promoted collateral perfusion. Principal conclusions: Our results provide evidence of collateral functional perfusion in the skull base, deep brain, and surface of the cortex. Rapamycin was capable of enlarging the diameter of collaterals, potentially extending the time window for ischemic stroke therapy.
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Lillicrap T, Tahtalı M, Neely A, Wang X, Bivard A, Lueck C. A model based on the Pennes bioheat transfer equation is valid in normal brain tissue but not brain tissue suffering focal ischaemia. AUSTRALASIAN PHYSICAL & ENGINEERING SCIENCES IN MEDICINE 2017; 40:841-850. [PMID: 29098600 DOI: 10.1007/s13246-017-0595-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2017] [Accepted: 10/18/2017] [Indexed: 11/29/2022]
Abstract
Ischaemic stroke is a major public health issue in both developed and developing nations. Hypothermia is believed to be neuroprotective in cerebral ischaemia. Conversely, elevated brain temperature is associated with poor outcome after ischaemic stroke. Mechanisms of heat exchange in normally-perfused brain are relatively well understood, but these mechanisms have not been studied as extensively during focal cerebral ischaemia. A finite element model (FEM) of heat exchange during focal ischaemia in the human brain was developed, based on the Pennes bioheat equation. This model incorporated healthy (normally-perfused) brain tissue, tissue that was mildly hypoperfused but not at risk of cell death (referred to as oligaemia), tissue that was hypoperfused and at risk of death but not dead (referred to as penumbra) and tissue that had died as a result of ischaemia (referred to as infarct core). The results of simulations using this model were found to match previous in-vivo temperature data for normally-perfused brain. However, the results did not match what limited data are available for hypoperfused brain tissue, in particular the penumbra, which is the focus of acute neuroprotective treatments such as hypothermia. These results suggest that the assumptions of the Pennes bioheat equation, while valid in the brain under normal circumstances, are not valid during focal ischaemia. Further investigation into the heat exchange profiles that do occur during focal ischaemia may yield results for clinical trials of therapeutic hypothermia.
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Affiliation(s)
| | - Murat Tahtalı
- School of Engineering and IT, UNSW Canberra, Canberra, Australia
| | - Andrew Neely
- School of Engineering and IT, UNSW Canberra, Canberra, Australia
| | - Xiaofei Wang
- National University of Singapore, Singapore, Singapore
| | - Andrew Bivard
- Hunter Medical Research Institute, Newcastle, NSW, Australia
| | - Christian Lueck
- Medical School, Australian National University, Canberra, Australia.,Neurology Department, The Canberra Hospital, Canberra, Australia
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Abstract
Over the last few decades, the management of acute ischemic stroke has undergone significant advancements with the introduction of intravenous thrombolysis and more recently punctuated by the success of endovascular mechanical thrombectomy trials for large vessel occlusion. These advancements have transformed the practice of neurocritical care. In this review, we present a case-based discussion of common brain reperfusion techniques with an emphasis on complication recognition and management. The article encompasses recent evidence-based recommendations as well as some of our own institutional protocols.
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Recombinant T cell receptor ligand treatment improves neurological outcome in the presence of tissue plasminogen activator in experimental ischemic stroke. Transl Stroke Res 2014; 5:612-7. [PMID: 24953050 DOI: 10.1007/s12975-014-0348-8] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2014] [Revised: 05/09/2014] [Accepted: 05/19/2014] [Indexed: 11/27/2022]
Abstract
RTL1000 is a partial human MHC molecule coupled to a human myelin peptide. We previously demonstrated that RTL1000 was protective against experimental ischemic stroke in HLA-DR2 transgenic (DR2-Tg) mice. Since thrombolysis with recombinant tissue plasminogen activator (t-PA) is a standard therapy for stroke, we determined if RTL1000 efficacy is altered when combined with t-PA in experimental stroke. Male DR2-Tg mice underwent 60 min of intraluminal middle cerebral artery occlusion (MCAO). t-PA or vehicle was infused intravenously followed by either a single or four daily subcutaneous injections of RTL1000 or vehicle. Infarct size was measured by 2, 3, 5-triphenyltetrazolium chloride staining at 24 or 96 h of reperfusion. Our data showed that t-PA alone reduced infarct size when measured at 24 h but not at 96 h after MCAO. RTL1000 alone reduced infarct size both at 24 and 96 h after MCAO. Combining RTL1000 with t-PA did not alter its ability to reduce infarct size at either 24 or 96 h after MCAO and provides additional protection in t-PA treated mice at 24 h after ischemic stroke. Taken together, RTL1000 treatment alone improves outcome and provides additional protection in t-PA-treated mice in experimental ischemic stroke.
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Lin L, Bivard A, Levi CR, Parsons MW. Comparison of Computed Tomographic and Magnetic Resonance Perfusion Measurements in Acute Ischemic Stroke. Stroke 2014; 45:1727-32. [DOI: 10.1161/strokeaha.114.005419] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Longting Lin
- From the Stroke Research Program, Hunter Medical Research Institute (L.L., A.B., C.R.L., M.W.P.) and Department of Neurology, John Hunter Hospital (C.R.L., M.W.P.), The University of Newcastle, Newcastle, New South Wales, Australia
| | - Andrew Bivard
- From the Stroke Research Program, Hunter Medical Research Institute (L.L., A.B., C.R.L., M.W.P.) and Department of Neurology, John Hunter Hospital (C.R.L., M.W.P.), The University of Newcastle, Newcastle, New South Wales, Australia
| | - Christopher R. Levi
- From the Stroke Research Program, Hunter Medical Research Institute (L.L., A.B., C.R.L., M.W.P.) and Department of Neurology, John Hunter Hospital (C.R.L., M.W.P.), The University of Newcastle, Newcastle, New South Wales, Australia
| | - Mark W. Parsons
- From the Stroke Research Program, Hunter Medical Research Institute (L.L., A.B., C.R.L., M.W.P.) and Department of Neurology, John Hunter Hospital (C.R.L., M.W.P.), The University of Newcastle, Newcastle, New South Wales, Australia
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Sealock R, Zhang H, Lucitti JL, Moore SM, Faber JE. Congenic fine-mapping identifies a major causal locus for variation in the native collateral circulation and ischemic injury in brain and lower extremity. Circ Res 2013; 114:660-71. [PMID: 24300334 DOI: 10.1161/circresaha.114.302931] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
RATIONALE Severity of tissue injury in occlusive disease is dependent on the extent (number and diameter) of collateral vessels, which varies widely among healthy mice and humans. However, the causative genetic elements are unknown. Recently, much of the variation among different mouse strains, including C57Bl/6J (B6, high extent) and BALB/cByJ (Bc, low extent), was linked to a quantitative trait locus on chromosome 7 (Candq1). OBJECTIVE We used congenic mapping to refine Candq1 and its candidate genes to create an isogenic strain set with large differences in collateral extent to assess their impact and the impact of Candq1, alone, on ischemic injury. METHODS AND RESULTS Six congenic strains possessing portions of Candq1 introgressed from B6 into Bc were generated and phenotyped. Candq1 was refined from 27 to 0.737 Mb with full retention of effect, that is, return or rescue of phenotypes from the poor values in Bc to nearly those of wild-type B6 in the B6/B6 congenic mice as follows: 83% rescue of low pial collateral extent and 4.5-fold increase in blood flow and 85% reduction of infarct volume after middle cerebral artery occlusion; 54% rescue of low skeletal muscle collaterals and augmented recovery of perfusion (83%) and function after femoral artery ligation. Gene deletion and in silico analysis further delineated the candidate genes. CONCLUSIONS We have significantly refined Candq1 (now designated determinant of collateral extent 1; Dce1), demonstrated that genetic background-dependent variation in collaterals is a major factor underlying differences in ischemic tissue injury, and generated a congenic strain set with wide allele dose-dependent variation in collateral extent for use in investigations of the collateral circulation.
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Affiliation(s)
- Robert Sealock
- From the Departments of Cell Biology and Physiology (R.S., H.Z., J.L.L., J.E.F.) and Surgery (S.M.M.), and The McAllister Heart Institute (H.Z., J.L.L., J.E.F.), School of Medicine, University of North Carolina at Chapel Hill, NC
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Liebeskind DS, Alexandrov AV. Advanced multimodal CT/MRI approaches to hyperacute stroke diagnosis, treatment, and monitoring. Ann N Y Acad Sci 2012; 1268:1-7. [PMID: 22994214 DOI: 10.1111/j.1749-6632.2012.06719.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Multimodal CT/MRI has dramatically changed the approach to ischemic stroke management, as noninvasive CT/MRI images detail brain tissue or parenchyma, angiography or vessel status, and collateral perfusion or blood flow in regions of the brain vulnerable to ischemic injury. Such snapshots of the dynamic process of cerebral ischemia may be used to gauge reversibility and therapeutic opportunities. Treatment of acute stroke may be rapidly tailored to clinical scenarios based on imaging correlation of ischemia, vessel status, and perfusion. Serial or repeated imaging from the initial presentation to later stages of the hospital course may illustrate infarct growth, persisting occlusion, reocclusion, recanalization, reperfusion, and hemorrhagic transformation. From acute stroke to rehabilitation phases and subsequent prevention, multimodal CT/MRI has emerged as a key tool to track the process of stroke and the impact of our therapeutic interventions.
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Affiliation(s)
- David S Liebeskind
- UCLA Stroke Center, Los Angeles, California, Los Angeles, California, USA.
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Albumin therapy enhances collateral perfusion after laser-induced middle cerebral artery branch occlusion: a laser speckle contrast flow study. J Cereb Blood Flow Metab 2012; 32:2012-22. [PMID: 22781334 PMCID: PMC3493990 DOI: 10.1038/jcbfm.2012.102] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Laser speckle contrast (LSC) was used to compare the extent of cortical ischemia in two inbred mouse strains that differed in their degree of collateral circulation, after laser occlusion of the distal middle cerebral artery, and after treatment with 25% albumin (ALB) or saline (control). Sequential LSC images acquired over ∼90 minutes were coaligned, converted to relative flow, and normalized to baseline. After 3-day survival, infarction was quantified by triphenyl tetrazolium chloride or magnetic resonance imaging. In the sparsely collateralized BALB/c strain, mean flow fell to 13% to 14% and 33% to 34% of baseline in central (core) and peripheral (penumbral) regions of interest, and ALB treatment at 30 minutes enhanced perfusion in both regions by ∼2-fold relative to saline, restoring flow to the benign-oligemic range centrally, and to the hyperemic range peripherally. The ALB-induced increment in parenchymal perfusion was disproportionate to the subtle flow increase in the occluded artery itself, suggesting that ALB improved collateral circulation. Cortical infarction in BALB/c mice was reduced 45% by ALB treatment. In contrast to BALB/c mice, the better-collateralized CD-1 strain developed milder ischemia, had smaller infarcts, and showed no differential benefit of ALB. We conclude that where native collateralization is insufficient (BALB/c strain), ALB treatment exerts a significant therapeutic effect after ischemia by augmenting collateral perfusion.
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