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Khan MB, Alam H, Siddiqui S, Shaikh MF, Sharma A, Rehman A, Baban B, Arbab AS, Hess DC. Exercise Improves Cerebral Blood Flow and Functional Outcomes in an Experimental Mouse Model of Vascular Cognitive Impairment and Dementia (VCID). Transl Stroke Res 2024; 15:446-461. [PMID: 36689081 PMCID: PMC10363247 DOI: 10.1007/s12975-023-01124-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2022] [Revised: 12/14/2022] [Accepted: 01/04/2023] [Indexed: 01/24/2023]
Abstract
Vascular cognitive impairment and dementia (VCID) are a growing threat to public health without any known treatment. The bilateral common carotid artery stenosis (BCAS) mouse model is valid for VCID. Previously, we have reported that remote ischemic postconditioning (RIPostC) during chronic cerebral hypoperfusion (CCH) induced by BCAS increases cerebral blood flow (CBF), improves cognitive function, and reduces white matter damage. We hypothesized that physical exercise (EXR) would augment CBF during CCH and prevent cognitive impairment in the BCAS model. BCAS was performed in C57/B6 mice of both sexes to establish CCH. One week after the BCAS surgery, mice were randomized to treadmill exercise once daily or no EXR for four weeks. CBF was monitored with an LSCI pre-, post, and 4 weeks post-BCAS. Cognitive testing was performed for post-BCAS after exercise training, and brain tissue was harvested for histopathology and biochemical test. BCAS led to chronic hypoperfusion resulting in impaired cognitive function and other functional outcomes. Histological examination revealed that BCAS caused changes in neuronal morphology and cell death in the cortex and hippocampus. Immunoblotting showed that BCAS was associated with a significant downregulate of AMPK and pAMPK and NOS3 and pNOS3. BCAS also decreased red blood cell (RBC) deformability. EXR therapy increased and sustained improved CBF and cognitive function, muscular strength, reduced cell death, and loss of white matter. EXR is effective in the BCAS model, improving CBF and cognitive function, reducing white matter damage, improving RBC deformability, and increasing RBC NOS3 and AMPK. The mechanisms by which EXR improves CBF and attenuates tissue damage need further investigation.
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Affiliation(s)
- Mohammad Badruzzaman Khan
- Department of Neurology, Medical College of Georgia, Augusta University, 1120 15thStreet, CA 1053, Augusta, GA, 30912, USA.
| | - Haroon Alam
- Department of Neurology, Medical College of Georgia, Augusta University, 1120 15thStreet, CA 1053, Augusta, GA, 30912, USA
| | - Shahneela Siddiqui
- Department of Neurology, Medical College of Georgia, Augusta University, 1120 15thStreet, CA 1053, Augusta, GA, 30912, USA
| | - Muhammad Fasih Shaikh
- Department of Neurology, Medical College of Georgia, Augusta University, 1120 15thStreet, CA 1053, Augusta, GA, 30912, USA
| | - Abhinav Sharma
- Department of Neurology, Medical College of Georgia, Augusta University, 1120 15thStreet, CA 1053, Augusta, GA, 30912, USA
| | - Amna Rehman
- Department of Neurology, Medical College of Georgia, Augusta University, 1120 15thStreet, CA 1053, Augusta, GA, 30912, USA
| | - Babak Baban
- Department of Oral Biology, Dental College of Georgia, Augusta University, Augusta, GA, 30912, USA
| | - Ali S Arbab
- Georgia Cancer Center, Augusta University, Augusta, GA, 30912, USA
| | - David C Hess
- Department of Neurology, Medical College of Georgia, Augusta University, 1120 15thStreet, CA 1053, Augusta, GA, 30912, USA
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2
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Askew KE, Beverley J, Sigfridsson E, Szymkowiak S, Emelianova K, Dando O, Hardingham GE, Duncombe J, Hennessy E, Koudelka J, Samarasekera N, Salman RAS, Smith C, Tavares AAS, Gomez-Nicola D, Kalaria RN, McColl BW, Horsburgh K. Inhibiting CSF1R alleviates cerebrovascular white matter disease and cognitive impairment. Glia 2024; 72:375-395. [PMID: 37909242 PMCID: PMC10952452 DOI: 10.1002/glia.24481] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2023] [Revised: 09/27/2023] [Accepted: 10/04/2023] [Indexed: 11/02/2023]
Abstract
White matter abnormalities, related to poor cerebral perfusion, are a core feature of small vessel cerebrovascular disease, and critical determinants of vascular cognitive impairment and dementia. Despite this importance there is a lack of treatment options. Proliferation of microglia producing an expanded, reactive population and associated neuroinflammatory alterations have been implicated in the onset and progression of cerebrovascular white matter disease, in patients and in animal models, suggesting that targeting microglial proliferation may exert protection. Colony-stimulating factor-1 receptor (CSF1R) is a key regulator of microglial proliferation. We found that the expression of CSF1R/Csf1r and other markers indicative of increased microglial abundance are significantly elevated in damaged white matter in human cerebrovascular disease and in a clinically relevant mouse model of chronic cerebral hypoperfusion and vascular cognitive impairment. Using the mouse model, we investigated long-term pharmacological CSF1R inhibition, via GW2580, and demonstrated that the expansion of microglial numbers in chronic hypoperfused white matter is prevented. Transcriptomic analysis of hypoperfused white matter tissue showed enrichment of microglial and inflammatory gene sets, including phagocytic genes that were the predominant expression modules modified by CSF1R inhibition. Further, CSF1R inhibition attenuated hypoperfusion-induced white matter pathology and rescued spatial learning impairments and to a lesser extent cognitive flexibility. Overall, this work suggests that inhibition of CSF1R and microglial proliferation mediates protection against chronic cerebrovascular white matter pathology and cognitive deficits. Our study nominates CSF1R as a target for the treatment of vascular cognitive disorders with broader implications for treatment of other chronic white matter diseases.
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Affiliation(s)
- Katharine E Askew
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK
| | - Joshua Beverley
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK
| | - Emma Sigfridsson
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK
| | - Stefan Szymkowiak
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK
- UK Dementia Research Institute, University of Edinburgh, Edinburgh, UK
| | - Katherine Emelianova
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK
- UK Dementia Research Institute, University of Edinburgh, Edinburgh, UK
| | - Owen Dando
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK
- UK Dementia Research Institute, University of Edinburgh, Edinburgh, UK
| | - Giles E Hardingham
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK
- UK Dementia Research Institute, University of Edinburgh, Edinburgh, UK
| | - Jessica Duncombe
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK
| | - Edel Hennessy
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK
| | - Juraj Koudelka
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK
- UK Dementia Research Institute, University of Edinburgh, Edinburgh, UK
| | - Neshika Samarasekera
- Centre for Clinical Brain Sciences and Sudden Death Brain Bank, University of Edinburgh, Edinburgh, UK
| | - Rustam Al-Shahi Salman
- Centre for Clinical Brain Sciences and Sudden Death Brain Bank, University of Edinburgh, Edinburgh, UK
| | - Colin Smith
- Centre for Clinical Brain Sciences and Sudden Death Brain Bank, University of Edinburgh, Edinburgh, UK
| | - Adriana A S Tavares
- British Heart Foundation Centre for Cardiovascular Science, University of Edinburgh, Edinburgh, UK
| | - Diego Gomez-Nicola
- School of Biological Sciences, University of Southampton, Southampton, UK
| | - Raj N Kalaria
- Clinical and Translational Research Institute, Newcastle University, Newcastle, UK
| | - Barry W McColl
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK
- UK Dementia Research Institute, University of Edinburgh, Edinburgh, UK
| | - Karen Horsburgh
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK
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3
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Ishikawa H, Shindo A, Mizutani A, Tomimoto H, Lo EH, Arai K. A brief overview of a mouse model of cerebral hypoperfusion by bilateral carotid artery stenosis. J Cereb Blood Flow Metab 2023; 43:18-36. [PMID: 36883344 PMCID: PMC10638994 DOI: 10.1177/0271678x231154597] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Revised: 12/23/2022] [Accepted: 01/04/2023] [Indexed: 03/09/2023]
Abstract
Vascular cognitive impairment (VCI) refers to all forms of cognitive disorder related to cerebrovascular diseases, including vascular mild cognitive impairment, post-stroke dementia, multi-infarct dementia, subcortical ischemic vascular dementia (SIVD), and mixed dementia. Among the causes of VCI, more attention has been paid to SIVD because the causative cerebral small vessel pathologies are frequently observed in elderly people and because the gradual progression of cognitive decline often mimics Alzheimer's disease. In most cases, small vessel diseases are accompanied by cerebral hypoperfusion. In mice, prolonged cerebral hypoperfusion is induced by bilateral carotid artery stenosis (BCAS) with surgically implanted metal micro-coils. This cerebral hypoperfusion BCAS model was proposed as a SIVD mouse model in 2004, and the spreading use of this mouse SIVD model has provided novel data regarding cognitive dysfunction and histological/genetic changes by cerebral hypoperfusion. Oxidative stress, microvascular injury, excitotoxicity, blood-brain barrier dysfunction, and secondary inflammation may be the main mechanisms of brain damage due to prolonged cerebral hypoperfusion, and some potential therapeutic targets for SIVD have been proposed by using transgenic mice or clinically used drugs in BCAS studies. This review article overviews findings from the studies that used this hypoperfused-SIVD mouse model, which were published between 2004 and 2021.
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Affiliation(s)
- Hidehiro Ishikawa
- Neuroprotection Research Laboratory, Departments of Radiology and Neurology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA
- Department of Neurology, Mie University Graduate School of Medicine, Tsu, Japan
| | - Akihiro Shindo
- Department of Neurology, Mie University Graduate School of Medicine, Tsu, Japan
| | - Akane Mizutani
- Department of Neurology, Mie University Graduate School of Medicine, Tsu, Japan
| | - Hidekazu Tomimoto
- Department of Neurology, Mie University Graduate School of Medicine, Tsu, Japan
| | - Eng H Lo
- Neuroprotection Research Laboratory, Departments of Radiology and Neurology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA
| | - Ken Arai
- Neuroprotection Research Laboratory, Departments of Radiology and Neurology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA
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4
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Yu W, Li Y, Hu J, Wu J, Huang Y. A Study on the Pathogenesis of Vascular Cognitive Impairment and Dementia: The Chronic Cerebral Hypoperfusion Hypothesis. J Clin Med 2022; 11:jcm11164742. [PMID: 36012981 PMCID: PMC9409771 DOI: 10.3390/jcm11164742] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2022] [Revised: 07/27/2022] [Accepted: 08/02/2022] [Indexed: 11/16/2022] Open
Abstract
The pathogenic mechanisms underlying vascular cognitive impairment and dementia (VCID) remain controversial due to the heterogeneity of vascular causes and complexity of disease neuropathology. However, one common feature shared among all these vascular causes is cerebral blood flow (CBF) dysregulation, and chronic cerebral hypoperfusion (CCH) is the universal consequence of CBF dysregulation, which subsequently results in an insufficient blood supply to the brain, ultimately contributing to VCID. The purpose of this comprehensive review is to emphasize the important contributions of CCH to VCID and illustrate the current findings about the mechanisms involved in CCH-induced VCID pathological changes. Specifically, evidence is mainly provided to support the molecular mechanisms, including Aβ accumulation, inflammation, oxidative stress, blood-brain barrier (BBB) disruption, trophic uncoupling and white matter lesions (WMLs). Notably, there are close interactions among these multiple mechanisms, and further research is necessary to elucidate the hitherto unsolved questions regarding these interactions. An enhanced understanding of the pathological features in preclinical models could provide a theoretical basis, ultimately achieving the shift from treatment to prevention.
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Affiliation(s)
- Weiwei Yu
- Department of Neurology, Peking University Shenzhen Hospital, 1120 Lianhua Road, Futian District, Shenzhen 518036, China
| | - Yao Li
- Department of Neurology, Peking University Shenzhen Hospital, 1120 Lianhua Road, Futian District, Shenzhen 518036, China
| | - Jun Hu
- Department of Neurology, Peking University Shenzhen Hospital, 1120 Lianhua Road, Futian District, Shenzhen 518036, China
| | - Jun Wu
- Department of Neurology, Peking University Shenzhen Hospital, 1120 Lianhua Road, Futian District, Shenzhen 518036, China
- Correspondence: (J.W.); (Y.H.); Tel.: +86-0755-8392-2833 (J.W.); +86-010-83572857 (Y.H.)
| | - Yining Huang
- Department of Neurology, Peking University First Hospital, 8 Xishiku Street Xicheng District, Beijing 100034, China
- Correspondence: (J.W.); (Y.H.); Tel.: +86-0755-8392-2833 (J.W.); +86-010-83572857 (Y.H.)
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5
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Tan Z, Yang G, Qiu J, Yan W, Liu Y, Ma Z, Li J, Liu J, Shan N. Quercetin Alleviates Demyelination Through Regulating Microglial Phenotype Transformation to Mitigate Neuropsychiatric Symptoms in Mice with Vascular Dementia. Mol Neurobiol 2022; 59:3140-3158. [PMID: 35267135 DOI: 10.1007/s12035-021-02712-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Accepted: 12/21/2021] [Indexed: 12/12/2022]
Abstract
Cerebral hypoperfusion plays a pivotal role in the ictus and development of vascular dementia (VaD) with neuropsychiatric symptoms. To date, few pharmacological interventions for neuropsychiatric symptoms are available in the VaD patients with neuropsychiatric impairments. Here, our results demonstrated that the extent of demyelination was dramatically deteriorated and the thickness of myelin sheath was evidently decreased in the presence of cerebral hypoperfusion, whereas Quercetin possessed the potential of abrogating these effects at least in part, then relieving anxiety and depression-like behavior when mice exposed to bilateral carotid artery stenosis (BCAS)/chronic restraint stress (CRS). The underlying mechanism was that Quercetin facilitated secretion of anti-inflammatory cytokines (IL-4 and IL-10) and in turn decreased production of pro-inflammatory factors (TNF-α and IL-1β) due to regulating microglial phenotype transformation, thereafter enhancing the microglial engulfment ability of myelin fragments in vitro and in vivo. Collectively, the results demonstrated that that Quercetin mediated microglial transformation into anti-inflammatory phenotype to reduce demyelination in ventral hippocampus (vHIP), thereafter mitigating neuropsychiatric deficits (including anxiety and depression). The present research broadens the therapeutic scope of Quercetin in central nervous system (CNS) disorders with presence of white matter damage and/or the insufficient activation of anti-inflammatory microglia, particularly for vascular dementia with/without neuropsychiatric symptoms.
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Affiliation(s)
- Zihu Tan
- Department of Geriatrics, Hubei Provincial Hospital of Traditional Chinese Medicine, Wuhan, 430061, China.,Affiliated Hospital of Hubei University of Chinese Medicine, Wuhan, 430061, China.,Hubei Provincial Academy of Traditional Chinese Medicine, 430061, Wuhan, Hubei, People's Republic of China
| | - Guang Yang
- Department of Geriatrics, Hubei Provincial Hospital of Traditional Chinese Medicine, Wuhan, 430061, China.,Affiliated Hospital of Hubei University of Chinese Medicine, Wuhan, 430061, China.,Hubei Provincial Academy of Traditional Chinese Medicine, 430061, Wuhan, Hubei, People's Republic of China
| | - Jing Qiu
- Department of Geriatrics, Hubei Provincial Hospital of Traditional Chinese Medicine, Wuhan, 430061, China.,Affiliated Hospital of Hubei University of Chinese Medicine, Wuhan, 430061, China.,Hubei Provincial Academy of Traditional Chinese Medicine, 430061, Wuhan, Hubei, People's Republic of China
| | - Wenjing Yan
- Clinical College of Traditional Chinese Medicine, Hubei University of Chinese Medicine, Wuhan, 430061, China
| | - Yu Liu
- Department of Geriatrics, Hubei Provincial Hospital of Traditional Chinese Medicine, Wuhan, 430061, China.,Affiliated Hospital of Hubei University of Chinese Medicine, Wuhan, 430061, China.,Hubei Provincial Academy of Traditional Chinese Medicine, 430061, Wuhan, Hubei, People's Republic of China
| | - Zhengling Ma
- Clinical College of Traditional Chinese Medicine, Hubei University of Chinese Medicine, Wuhan, 430061, China
| | - Jia Li
- College of Acupuncture and Orthopedics, Hubei University of Chinese Medicine/Hubei Provincial Collaborative Innovation Center of Preventive Treatment By Acupuncture and Moxibustion, Wuhan, 430061, China
| | - Jing Liu
- College of Acupuncture and Orthopedics, Hubei University of Chinese Medicine/Hubei Provincial Collaborative Innovation Center of Preventive Treatment By Acupuncture and Moxibustion, Wuhan, 430061, China
| | - Nan Shan
- Department of Geriatrics, Hubei Provincial Hospital of Traditional Chinese Medicine, Wuhan, 430061, China. .,Affiliated Hospital of Hubei University of Chinese Medicine, Wuhan, 430061, China. .,Hubei Provincial Academy of Traditional Chinese Medicine, 430061, Wuhan, Hubei, People's Republic of China.
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6
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Hall GR, Boehm-Sturm P, Dirnagl U, Finke C, Foddis M, Harms C, Koch SP, Kuchling J, Madan CR, Mueller S, Sassi C, Sotiropoulos SN, Trueman RC, Wallis MD, Yildirim F, Farr TD. Long-Term Connectome Analysis Reveals Reshaping of Visual, Spatial Networks in a Model With Vascular Dementia Features. Stroke 2022; 53:1735-1745. [PMID: 35105183 PMCID: PMC9022688 DOI: 10.1161/strokeaha.121.036997] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/05/2022]
Abstract
Connectome analysis of neuroimaging data is a rapidly expanding field that offers the potential to diagnose, characterize, and predict neurological disease. Animal models provide insight into biological mechanisms that underpin disease, but connectivity approaches are currently lagging in the rodent.
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Affiliation(s)
- Gerard R Hall
- School of Life Sciences, University of Nottingham, United Kingdom (G.R.H., R.C.T., M.D.W., T.D.F.)
| | - Philipp Boehm-Sturm
- Department of Experimental Neurology, Center for Stroke Research Berlin, Charité-Universitätsmedizin Berlin (P.B.-S., U.D., M.F., C.H., S.P.K., S.M., C.S., T.D.F.).,corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin and Berlin Institute of Health, Germany. NeuroCure Cluster of Excellence and Charité Core Facility 7T Experimental MRIs, Charité-Universitätsmedizin Berlin, Germany. (P.B.-S., U.D., M.F., C.H., S.P.K., S.M., C.S., F.Y., T.D.F.)
| | - Ulrich Dirnagl
- Department of Experimental Neurology, Center for Stroke Research Berlin, Charité-Universitätsmedizin Berlin (P.B.-S., U.D., M.F., C.H., S.P.K., S.M., C.S., T.D.F.).,corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin and Berlin Institute of Health, Germany. NeuroCure Cluster of Excellence and Charité Core Facility 7T Experimental MRIs, Charité-Universitätsmedizin Berlin, Germany. (P.B.-S., U.D., M.F., C.H., S.P.K., S.M., C.S., F.Y., T.D.F.).,German Center for Neurodegenerative Diseases, Berlin Site, Germany (U.D.)
| | - Carsten Finke
- Department of Neurology, Charité-Universitätsmedizin Berlin, Germany. (C.F., J.K.).,Berlin School of Mind and Brain, Humboldt Universität zu Berlin, Germany (C.F.)
| | - Marco Foddis
- Department of Experimental Neurology, Center for Stroke Research Berlin, Charité-Universitätsmedizin Berlin (P.B.-S., U.D., M.F., C.H., S.P.K., S.M., C.S., T.D.F.).,corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin and Berlin Institute of Health, Germany. NeuroCure Cluster of Excellence and Charité Core Facility 7T Experimental MRIs, Charité-Universitätsmedizin Berlin, Germany. (P.B.-S., U.D., M.F., C.H., S.P.K., S.M., C.S., F.Y., T.D.F.)
| | - Christoph Harms
- Department of Experimental Neurology, Center for Stroke Research Berlin, Charité-Universitätsmedizin Berlin (P.B.-S., U.D., M.F., C.H., S.P.K., S.M., C.S., T.D.F.).,corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin and Berlin Institute of Health, Germany. NeuroCure Cluster of Excellence and Charité Core Facility 7T Experimental MRIs, Charité-Universitätsmedizin Berlin, Germany. (P.B.-S., U.D., M.F., C.H., S.P.K., S.M., C.S., F.Y., T.D.F.)
| | - Stefan Paul Koch
- Department of Experimental Neurology, Center for Stroke Research Berlin, Charité-Universitätsmedizin Berlin (P.B.-S., U.D., M.F., C.H., S.P.K., S.M., C.S., T.D.F.).,corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin and Berlin Institute of Health, Germany. NeuroCure Cluster of Excellence and Charité Core Facility 7T Experimental MRIs, Charité-Universitätsmedizin Berlin, Germany. (P.B.-S., U.D., M.F., C.H., S.P.K., S.M., C.S., F.Y., T.D.F.)
| | - Joseph Kuchling
- Experimental and Clinical Research Center, Max Delbrueck Center for Molecular Medicine and Charité-Universitätsmedizin Berlin (J.K.).,Department of Neurology, Charité-Universitätsmedizin Berlin, Germany. (C.F., J.K.)
| | | | - Susanne Mueller
- Department of Experimental Neurology, Center for Stroke Research Berlin, Charité-Universitätsmedizin Berlin (P.B.-S., U.D., M.F., C.H., S.P.K., S.M., C.S., T.D.F.).,corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin and Berlin Institute of Health, Germany. NeuroCure Cluster of Excellence and Charité Core Facility 7T Experimental MRIs, Charité-Universitätsmedizin Berlin, Germany. (P.B.-S., U.D., M.F., C.H., S.P.K., S.M., C.S., F.Y., T.D.F.)
| | - Celeste Sassi
- Department of Experimental Neurology, Center for Stroke Research Berlin, Charité-Universitätsmedizin Berlin (P.B.-S., U.D., M.F., C.H., S.P.K., S.M., C.S., T.D.F.).,corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin and Berlin Institute of Health, Germany. NeuroCure Cluster of Excellence and Charité Core Facility 7T Experimental MRIs, Charité-Universitätsmedizin Berlin, Germany. (P.B.-S., U.D., M.F., C.H., S.P.K., S.M., C.S., F.Y., T.D.F.)
| | - Stamatios N Sotiropoulos
- Sir Peter Mansfield Imaging Centre, School of Medicine, University of Nottingham, United Kingdom (S.N.S.).,Centre for Functional MRI of the Brain, University of Oxford, United Kingdom (S.N.S.)
| | - Rebecca C Trueman
- School of Life Sciences, University of Nottingham, United Kingdom (G.R.H., R.C.T., M.D.W., T.D.F.)
| | - Marcus D Wallis
- School of Life Sciences, University of Nottingham, United Kingdom (G.R.H., R.C.T., M.D.W., T.D.F.)
| | - Ferah Yildirim
- corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin and Berlin Institute of Health, Germany. NeuroCure Cluster of Excellence and Charité Core Facility 7T Experimental MRIs, Charité-Universitätsmedizin Berlin, Germany. (P.B.-S., U.D., M.F., C.H., S.P.K., S.M., C.S., F.Y., T.D.F.).,NeuroCure Cluster of Excellence and Department of Psychiatry and Psychotherapy, Charité-Universitätsmedizin Berlin, Germany. (F.Y.)
| | - Tracy D Farr
- School of Life Sciences, University of Nottingham, United Kingdom (G.R.H., R.C.T., M.D.W., T.D.F.).,Department of Experimental Neurology, Center for Stroke Research Berlin, Charité-Universitätsmedizin Berlin (P.B.-S., U.D., M.F., C.H., S.P.K., S.M., C.S., T.D.F.).,corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin and Berlin Institute of Health, Germany. NeuroCure Cluster of Excellence and Charité Core Facility 7T Experimental MRIs, Charité-Universitätsmedizin Berlin, Germany. (P.B.-S., U.D., M.F., C.H., S.P.K., S.M., C.S., F.Y., T.D.F.)
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7
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Li M, Kitamura A, Beverley J, Koudelka J, Duncombe J, Lennen R, Jansen MA, Marshall I, Platt B, Wiegand UK, Carare RO, Kalaria RN, Iliff JJ, Horsburgh K. Impaired Glymphatic Function and Pulsation Alterations in a Mouse Model of Vascular Cognitive Impairment. Front Aging Neurosci 2022; 13:788519. [PMID: 35095472 PMCID: PMC8793139 DOI: 10.3389/fnagi.2021.788519] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2021] [Accepted: 12/07/2021] [Indexed: 12/24/2022] Open
Abstract
Large vessel disease and carotid stenosis are key mechanisms contributing to vascular cognitive impairment (VCI) and dementia. Our previous work, and that of others, using rodent models, demonstrated that bilateral common carotid stenosis (BCAS) leads to cognitive impairment via gradual deterioration of the neuro-glial-vascular unit and accumulation of amyloid-β (Aβ) protein. Since brain-wide drainage pathways (glymphatic) for waste clearance, including Aβ removal, have been implicated in the pathophysiology of VCI via glial mechanisms, we hypothesized that glymphatic function would be impaired in a BCAS model and exacerbated in the presence of Aβ. Male wild-type and Tg-SwDI (model of microvascular amyloid) mice were subjected to BCAS or sham surgery which led to a reduction in cerebral perfusion and impaired spatial learning acquisition and cognitive flexibility. After 3 months survival, glymphatic function was evaluated by cerebrospinal fluid (CSF) fluorescent tracer influx. We demonstrated that BCAS caused a marked regional reduction of CSF tracer influx in the dorsolateral cortex and CA1-DG molecular layer. In parallel to these changes increased reactive astrogliosis was observed post-BCAS. To further investigate the mechanisms that may lead to these changes, we measured the pulsation of cortical vessels. BCAS impaired vascular pulsation in pial arteries in WT and Tg-SwDI mice. Our findings show that BCAS influences VCI and that this is paralleled by impaired glymphatic drainage and reduced vascular pulsation. We propose that these additional targets need to be considered when treating VCI.
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Affiliation(s)
- Mosi Li
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, United Kingdom
- Edinburgh Medical School, UK Dementia Research Institute, University of Edinburgh, Edinburgh, United Kingdom
| | - Akihiro Kitamura
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, United Kingdom
- Department of Neurology, Shiga University of Medical Science, Otsu, Japan
| | - Joshua Beverley
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, United Kingdom
| | - Juraj Koudelka
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, United Kingdom
| | - Jessica Duncombe
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, United Kingdom
| | - Ross Lennen
- Centre for Cardiovascular Science, University of Edinburgh, Edinburgh, United Kingdom
| | - Maurits A Jansen
- Centre for Cardiovascular Science, University of Edinburgh, Edinburgh, United Kingdom
| | - Ian Marshall
- Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, United Kingdom
| | - Bettina Platt
- School of Medicine, Medical Sciences and Nutrition, College of Life Sciences and Medicine, University of Aberdeen, Aberdeen, United Kingdom
| | - Ulrich K Wiegand
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, United Kingdom
| | - Roxana O Carare
- Faculty of Medicine, University of Southampton, Southampton, United Kingdom
| | - Rajesh N Kalaria
- Translational and Clinical Research Institute, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Jeffrey J Iliff
- VISN 20 Mental Illness Research, Education and Clinical Center, VA Puget Sound Health Care System, Seattle, WA, United States
- Department of Psychiatry and Behavioral Sciences, University of Washington School of Medicine, Seattle, WA, United States
- Department of Neurology, University of Washington School of Medicine, Seattle, WA, United States
| | - Karen Horsburgh
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, United Kingdom
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8
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Mun J, Jung J, Park C. Effects of cerebral hypoperfusion on the cerebral white matter: a meta‑analysis. Acta Neurobiol Exp (Wars) 2021; 81:295-306. [PMID: 34672300 DOI: 10.21307/ane-2021-029] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Decreased cerebral blood flow (CBF) in aging is known to induce aging‑related cerebral deteriorations, such as neuronal degeneration, white matter (WM) alterations, and vascular deformations. However, the effects of cerebral hypoperfusion on WM alterations remain unclear. This study investigates the relationship between cerebral hypoperfusion and WM total volume changes by assessing the trends in CBF and WM changes by meta‑analysis. In this meta‑analysis, the differences in CBF were compared according to cerebral hypoperfusion type and the effect of cerebral hypoperfusion on the total volume of WM changes in rodents. Using subgroup analysis, 13 studies were evaluated for comparing CBF according to the type of cerebral hypoperfusion; 12 studies were evaluated for comparing the effects of cerebral hypoperfusion on the total volume of WM changes. Our meta‑analysis shows that the total volume of WM decreases with a decrease in CBF. However, the reduction in\r\nthe total volume of WM was greater in normal aging mice than in the cerebral hypoperfusion model mice. These results suggest that the reduction of cerebral WM volume during the aging process is affected by other factors in addition to a decrease in CBF.
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Affiliation(s)
- Juyeon Mun
- Department of Biomedical Science, Graduate School, Kyung Hee University, Seoul, Republic of Korea
- Department of Anatomy and Neurobiology, College of Medicine, Kyung Hee University, Seoul, Republic of Korea
| | - Junyang Jung
- Department of Biomedical Science, Graduate School, Kyung Hee University, Seoul, Republic of Korea
- Department of Anatomy and Neurobiology, College of Medicine, Kyung Hee University, Seoul, Republic of Korea
| | - Chan Park
- Department of Biomedical Science, Graduate School, Kyung Hee University, Seoul, Republic of Korea
- Department of Anatomy and Neurobiology, College of Medicine, Kyung Hee University, Seoul, Republic of Korea;
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9
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Sigfridsson E, Marangoni M, Hardingham GE, Horsburgh K, Fowler JH. Deficiency of Nrf2 exacerbates white matter damage and microglia/macrophage levels in a mouse model of vascular cognitive impairment. J Neuroinflammation 2020; 17:367. [PMID: 33261626 PMCID: PMC7709339 DOI: 10.1186/s12974-020-02038-2] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Accepted: 11/17/2020] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND Chronic cerebral hypoperfusion causes damage to the brain's white matter underpinning vascular cognitive impairment. Inflammation and oxidative stress have been proposed as key pathophysiological mechanisms of which the transcription factor Nrf2 is a master regulator. We hypothesised that white matter pathology, microgliosis, blood-brain barrier breakdown and behavioural deficits induced by chronic hypoperfusion would be exacerbated in mice deficient in the transcription factor Nrf2. METHODS Mice deficient in Nrf2 (male heterozygote or homozygous for Nrf2 knockout) or wild-type littermates on a C57Bl6/J background underwent bilateral carotid artery stenosis (BCAS) to induce chronic cerebral hypoperfusion or sham surgery and survived for a further 6 weeks. White matter pathology was assessed with MAG immunohistochemistry as a marker of altered axon-glial integrity; alterations to astrocytes and microglia/macrophages were assessed with GFAP and Iba1 immunohistochemistry, and blood-brain barrier breakdown was assessed with IgG immunohistochemistry. Behavioural alterations were assessed using 8-arm radial arm maze, and alterations to Nrf2-related and inflammatory-related genes were assessed with qRT-PCR. RESULTS Chronic cerebral hypoperfusion induced white matter pathology, elevated microglial/macrophage levels and blood-brain barrier breakdown in white matter tracts that were increased in Nrf2+/- mice and further exacerbated by the complete absence of Nrf2. Chronic hypoperfusion induced white matter astrogliosis and induced an impairment in behaviour assessed with radial arm maze; however, these measures were not affected by Nrf2 deficiency. Although Nrf2-related antioxidant gene expression was not altered by chronic cerebral hypoperfusion, there was evidence for elevated pro-inflammatory related gene expression following chronic hypoperfusion that was not affected by Nrf2 deficiency. CONCLUSIONS The results demonstrate that the absence of Nrf2 exacerbates white matter pathology and microgliosis following cerebral hypoperfusion but does not affect behavioural impairment.
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Affiliation(s)
- Emma Sigfridsson
- Centre for Discovery Brain Sciences, University of Edinburgh, Chancellor’s Building, 49 Little France Crescent, Edinburgh, EH16 4SB UK
| | - Martina Marangoni
- Centre for Discovery Brain Sciences, University of Edinburgh, Chancellor’s Building, 49 Little France Crescent, Edinburgh, EH16 4SB UK
- Present address: Department of Health Sciences, University of Florence, Florence, Italy
| | - Giles E. Hardingham
- Centre for Discovery Brain Sciences, University of Edinburgh, Chancellor’s Building, 49 Little France Crescent, Edinburgh, EH16 4SB UK
- The UK Dementia Research Institute, University of Edinburgh, Edinburgh, UK
| | - Karen Horsburgh
- Centre for Discovery Brain Sciences, University of Edinburgh, Chancellor’s Building, 49 Little France Crescent, Edinburgh, EH16 4SB UK
| | - Jill H. Fowler
- Centre for Discovery Brain Sciences, University of Edinburgh, Chancellor’s Building, 49 Little France Crescent, Edinburgh, EH16 4SB UK
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10
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Stringer MS, Lee H, Huuskonen MT, MacIntosh BJ, Brown R, Montagne A, Atwi S, Ramirez J, Jansen MA, Marshall I, Black SE, Zlokovic BV, Benveniste H, Wardlaw JM. A Review of Translational Magnetic Resonance Imaging in Human and Rodent Experimental Models of Small Vessel Disease. Transl Stroke Res 2020; 12:15-30. [PMID: 32936435 PMCID: PMC7803876 DOI: 10.1007/s12975-020-00843-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Revised: 08/16/2020] [Accepted: 08/19/2020] [Indexed: 12/29/2022]
Abstract
Cerebral small vessel disease (SVD) is a major health burden, yet the pathophysiology remains poorly understood with no effective treatment. Since much of SVD develops silently and insidiously, non-invasive neuroimaging such as MRI is fundamental to detecting and understanding SVD in humans. Several relevant SVD rodent models are established for which MRI can monitor in vivo changes over time prior to histological examination. Here, we critically review the MRI methods pertaining to salient rodent models and evaluate synergies with human SVD MRI methods. We found few relevant publications, but argue there is considerable scope for greater use of MRI in rodent models, and opportunities for harmonisation of the rodent-human methods to increase the translational potential of models to understand SVD in humans. We summarise current MR techniques used in SVD research, provide recommendations and examples and highlight practicalities for use of MRI SVD imaging protocols in pre-selected, relevant rodent models.
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Affiliation(s)
- Michael S Stringer
- Brain Research Imaging Centre, Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, UK.,UK Dementia Research Institute, Edinburgh Medical School, University of Edinburgh, Edinburgh, UK
| | - Hedok Lee
- Department of Anesthesiology, Yale School of Medicine, Yale University, New Haven, CT, USA
| | - Mikko T Huuskonen
- Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA.,Department of Physiology and Neuroscience, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Bradley J MacIntosh
- Heart and Stroke Foundation Canadian Partnership for Stroke Recovery, Sunnybrook Research Institute, University of Toronto, Toronto, ON, Canada.,Department of Medical Biophysics, University of Toronto, Toronto, ON, Canada.,Hurvitz Brain Sciences Research Program, Sunnybrook Research Institute, Toronto, ON, Canada
| | - Rosalind Brown
- Brain Research Imaging Centre, Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, UK.,UK Dementia Research Institute, Edinburgh Medical School, University of Edinburgh, Edinburgh, UK
| | - Axel Montagne
- Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA.,Department of Physiology and Neuroscience, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Sarah Atwi
- Heart and Stroke Foundation Canadian Partnership for Stroke Recovery, Sunnybrook Research Institute, University of Toronto, Toronto, ON, Canada.,Department of Medical Biophysics, University of Toronto, Toronto, ON, Canada
| | - Joel Ramirez
- Heart and Stroke Foundation Canadian Partnership for Stroke Recovery, Sunnybrook Research Institute, University of Toronto, Toronto, ON, Canada.,Hurvitz Brain Sciences Research Program, Sunnybrook Research Institute, Toronto, ON, Canada
| | - Maurits A Jansen
- Edinburgh Preclinical Imaging, Centre for Cardiovascular Science, University of Edinburgh, Edinburgh, UK
| | - Ian Marshall
- Brain Research Imaging Centre, Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, UK.,UK Dementia Research Institute, Edinburgh Medical School, University of Edinburgh, Edinburgh, UK
| | - Sandra E Black
- Heart and Stroke Foundation Canadian Partnership for Stroke Recovery, Sunnybrook Research Institute, University of Toronto, Toronto, ON, Canada.,Hurvitz Brain Sciences Research Program, Sunnybrook Research Institute, Toronto, ON, Canada.,Department of Medicine (Neurology), University of Toronto, Toronto, ON, Canada
| | - Berislav V Zlokovic
- Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA.,Department of Physiology and Neuroscience, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Helene Benveniste
- Department of Anesthesiology, Yale School of Medicine, Yale University, New Haven, CT, USA
| | - Joanna M Wardlaw
- Brain Research Imaging Centre, Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, UK. .,UK Dementia Research Institute, Edinburgh Medical School, University of Edinburgh, Edinburgh, UK.
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11
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Gong X, Shan W, Yuan K, Lu Z, Zhang M, Lu J, Zhang X, Huang X, Guo H, Peng M, Liu X, Zhao X, Xu G. Dietary Inflammatory Index and Leukoaraiosis in Patients with Ischemic Stroke. J Nutr Health Aging 2020; 24:473-477. [PMID: 32346684 DOI: 10.1007/s12603-020-1351-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
OBJECTIVES Diet may change the chronic levels of systemic inflammation, which in turn influence the development of leukoaraiosis (LA). This study aimed to examine the association between dietary inflammatory index (DII) and LA in patients with ischemic stroke. METHODS Patients with first-ever ischemic stroke were enrolled from two centers. A semi-quantitative food frequency questionnaire (FFQ) was used to evaluate diet contents. The DII score of each patient was calculated based on the reported diet contents. Presence and degree of LA were evaluated with a magnetic resonance imaging (MRI) scan. LA was graded according to Fazekas scale. RESULTS Of the 497 enrolled patients, 337 (67.8%) were detected with LA. Patients with LA had a higher DII score (0.23 vs -0.88, P < 0.001). Logistic regression analysis detected that patients with highest quartile of DII score had an OR of 3.61 (95% CI: 2.05-6.36, P < 0.001) for LA compared with those with lowest quartile of DII. After adjusting for major confounders, the highest DII quartile remained as an independent predictor for LA (OR = 2.66, 95% CI: 1.41-5.00, P = 0.008). CONCLUSIONS A pro-inflammatory diet pattern, as indicated by higher DII values, appears to be associated with a higher risk of LA. This result suggested that dietary-mediated inflammation may involved in the pathogenesis of LA, which warrant further study.
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Affiliation(s)
- X Gong
- Gelin Xu, Department of Neurology, Jinling Hospital, First School of Clinical Medicine, Southern Medical University, 305 East Zhongshan Road, Nanjing, 210002, Jiangsu Province, China. Tel: (+) 86- 18951919349; E-Mail: ; Xiongfei Zhao, Department of Neurology, Cardiovascular and Cerebrovascular Disease Hospital of Meishan, Meishan 620000, Sichuan, China. Tel: (+) 86-13609147368;
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12
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Mustapha M, Nassir CMNCM, Aminuddin N, Safri AA, Ghazali MM. Cerebral Small Vessel Disease (CSVD) - Lessons From the Animal Models. Front Physiol 2019; 10:1317. [PMID: 31708793 PMCID: PMC6822570 DOI: 10.3389/fphys.2019.01317] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2018] [Accepted: 09/30/2019] [Indexed: 12/28/2022] Open
Abstract
Cerebral small vessel disease (CSVD) refers to a spectrum of clinical and imaging findings resulting from pathological processes of various etiologies affecting cerebral arterioles, perforating arteries, capillaries, and venules. Unlike large vessels, it is a challenge to visualize small vessels in vivo, hence the difficulty to directly monitor the natural progression of the disease. CSVD might progress for many years during the early stage of the disease as it remains asymptomatic. Prevalent among elderly individuals, CSVD has been alarmingly reported as an important precursor of full-blown stroke and vascular dementia. Growing evidence has also shown a significant association between CSVD's radiological manifestation with dementia and Alzheimer's disease (AD) pathology. Although it remains contentious as to whether CSVD is a cause or sequelae of AD, it is not far-fetched to posit that effective therapeutic measures of CSVD would mitigate the overall burden of dementia. Nevertheless, the unifying theory on the pathomechanism of the disease remains elusive, hence the lack of effective therapeutic approaches. Thus, this chapter consolidates the contemporary insights from numerous experimental animal models of CSVD, to date: from the available experimental animal models of CSVD and its translational research value; the pathomechanical aspects of the disease; relevant aspects on systems biology; opportunities for early disease biomarkers; and finally, converging approaches for future therapeutic directions of CSVD.
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Affiliation(s)
- Muzaimi Mustapha
- Department of Neurosciences, School of Medical Sciences, Universiti Sains Malaysia, Kubang Kerian, Malaysia
| | | | - Niferiti Aminuddin
- Department of Neurosciences, School of Medical Sciences, Universiti Sains Malaysia, Kubang Kerian, Malaysia
- Department of Basic Medical Sciences, Kulliyyah of Pharmacy, International Islamic University Malaysia, Kuantan, Malaysia
| | - Amanina Ahmad Safri
- Department of Neurosciences, School of Medical Sciences, Universiti Sains Malaysia, Kubang Kerian, Malaysia
| | - Mazira Mohamad Ghazali
- Department of Neurosciences, School of Medical Sciences, Universiti Sains Malaysia, Kubang Kerian, Malaysia
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13
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Wang M, Qin C, Luo X, Wang J, Wang X, Xie M, Hu J, Cao J, Hu T, Goldman SA, Nedergaard M, Wang W. Astrocytic connexin 43 potentiates myelin injury in ischemic white matter disease. Am J Cancer Res 2019; 9:4474-4493. [PMID: 31285774 PMCID: PMC6599652 DOI: 10.7150/thno.31942] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2018] [Accepted: 04/19/2019] [Indexed: 01/05/2023] Open
Abstract
Rational: Myelin loss is a characteristic feature of both ischemic white matter disease and its associated vascular dementia, and is a hallmark of chronic cerebral hypoperfusion due to carotid artery stenosis. Yet the cellular mechanisms involved in ischemic dysmyelination are not well-understood, and no effective treatment has emerged to prevent or slow hypoperfusion-related demyelination. In a study employing the bilateral common carotid artery stenosis (BCAS) mouse model, we found reduced cerebral blood flow velocity and arteriolar pulsatility, and confirmed that prolonged BCAS provoked myelin disruption. These pathological features were associated with marked cognitive decline, in the absence of evident damage to axons. Methods: To assess the role of astroglial communication in BCAS-associated demyelination, we investigated the effect of deleting or inhibiting connexin 43 (Cx43), a constituent of astroglial gap junctions and hemichannels. Results: Genetic deletion and pharmacological inhibition of gap junctions both protected myelin integrity and rescued cognitive decline in the BCAS-treated mice. Gap junction inhibition also suppressed the transient increase in extracellular glutamate observed in the callosal white matter of wild-type mice exposed to BCAS. Conclusion: These findings suggest that astrocytic Cx43 may be a viable target for attenuating the demyelination and cognitive decline associated with chronic cerebral hypoperfusion.
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14
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Wang F, Cao Y, Ma L, Pei H, Rausch WD, Li H. Dysfunction of Cerebrovascular Endothelial Cells: Prelude to Vascular Dementia. Front Aging Neurosci 2018; 10:376. [PMID: 30505270 PMCID: PMC6250852 DOI: 10.3389/fnagi.2018.00376] [Citation(s) in RCA: 91] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2018] [Accepted: 10/29/2018] [Indexed: 12/19/2022] Open
Abstract
Vascular dementia (VaD) is the second most common type of dementia after Alzheimer's disease (AD), characterized by progressive cognitive impairment, memory loss, and thinking or speech problems. VaD is usually caused by cerebrovascular disease, during which, cerebrovascular endothelial cells (CECs) are vulnerable. CEC dysfunction occurs before the onset of VaD and can eventually lead to dysregulation of cerebral blood flow and blood-brain barrier damage, followed by the activation of glia and inflammatory environment in the brain. White matter, neuronal axons, and synapses are compromised in this process, leading to cognitive impairment. The present review summarizes the mechanisms underlying CEC impairment during hypoperfusion and pathological role of CECs in VaD. Through the comprehensive examination and summarization, endothelial nitric oxide synthase (eNOS)/nitric oxide (NO) signaling pathway, Ras homolog gene family member A (RhoA) signaling pathway, and CEC-derived caveolin-1 (CAV-1) are proposed to serve as targets of new drugs for the treatment of VaD.
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Affiliation(s)
- Feixue Wang
- Department of Geriatrics, Xiyuan Hospital of China Academy of Chinese Medical Sciences, Beijing, China
| | - Yu Cao
- Department of Geriatrics, Xiyuan Hospital of China Academy of Chinese Medical Sciences, Beijing, China
| | - Lina Ma
- Department of Geriatrics, Xiyuan Hospital of China Academy of Chinese Medical Sciences, Beijing, China
| | - Hui Pei
- Department of Geriatrics, Xiyuan Hospital of China Academy of Chinese Medical Sciences, Beijing, China
| | - Wolf Dieter Rausch
- Department for Biomedical Sciences, Institute of Medical Biochemistry, University of Veterinary Medicine Vienna, Vienna, Austria
| | - Hao Li
- Department of Geriatrics, Xiyuan Hospital of China Academy of Chinese Medical Sciences, Beijing, China
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15
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Sigfridsson E, Marangoni M, Johnson JA, Hardingham GE, Fowler JH, Horsburgh K. Astrocyte-specific overexpression of Nrf2 protects against optic tract damage and behavioural alterations in a mouse model of cerebral hypoperfusion. Sci Rep 2018; 8:12552. [PMID: 30135571 PMCID: PMC6105641 DOI: 10.1038/s41598-018-30675-4] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2017] [Accepted: 07/30/2018] [Indexed: 12/19/2022] Open
Abstract
Mouse models have shown that cerebral hypoperfusion causes white matter disruption and memory impairment relevant to the study of vascular cognitive impairment and dementia. The associated mechanisms include inflammation and oxidative stress are proposed to drive disruption of myelinated axons within hypoperfused white matter. The aim of this study was to determine if increased endogenous anti-oxidant and anti-inflammatory signalling in astrocytes was protective in a model of mild cerebral hypoperfusion. Transgenically altered mice overexpressing the transcription factor Nrf2 (GFAP-Nrf2) and wild type littermates were subjected to bilateral carotid artery stenosis or sham surgery. Behavioural alterations were assessed using the radial arm maze and tissue was collected for pathology and transcriptome analysis six weeks post-surgery. GFAP-Nrf2 mice showed less pronounced behavioural impairments compared to wild types following hypoperfusion, paralleled by reduced optic tract white matter disruption and astrogliosis. There was no effect of hypoperfusion on anti-oxidant gene alterations albeit the levels were increased in GFAP-Nrf2 mice. Instead, pro-inflammatory gene expression was determined to be significantly upregulated in the optic tract of hypoperfused wild type mice but differentially affected in GFAP-Nrf2 mice. In particular, complement components (C4 and C1q) were increased in wild type hypoperfused mice but expressed at levels similar to controls in hypoperfused GFAP-Nrf2 mice. This study provides evidence that overexpression of Nrf2 in astrocytes exerts beneficial effects through repression of inflammation and supports the potential use of Nrf2-activators in the amelioration of cerebrovascular-related inflammation and white matter degeneration.
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Affiliation(s)
- Emma Sigfridsson
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK
| | - Martina Marangoni
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK
- Department of Health Sciences, University of Florence, Florence, Italy
| | - Jeffrey A Johnson
- Division of Pharmaceutical Sciences, University of Wisconsin, Madison, USA
- Molecular and Environmental Toxicology Center, University of Wisconsin, Madison, USA
- Center for Neuroscience, University of Wisconsin, Madison, USA
- Waisman Center, University of Wisconsin, Madison, USA
| | - Giles E Hardingham
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK
- Edinburgh Medical School, University of Edinburgh, Edinburgh, UK
- The UK Dementia Research Institute, University of Edinburgh, Edinburgh, UK
| | - Jill H Fowler
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK.
| | - Karen Horsburgh
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK.
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16
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Fowler JH, McQueen J, Holland PR, Manso Y, Marangoni M, Scott F, Chisholm E, Scannevin RH, Hardingham GE, Horsburgh K. Dimethyl fumarate improves white matter function following severe hypoperfusion: Involvement of microglia/macrophages and inflammatory mediators. J Cereb Blood Flow Metab 2018; 38:1354-1370. [PMID: 28606007 PMCID: PMC6077928 DOI: 10.1177/0271678x17713105] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The brain's white matter is highly vulnerable to reductions in cerebral blood flow via mechanisms that may involve elevated microgliosis and pro-inflammatory pathways. In the present study, the effects of severe cerebral hypoperfusion were investigated on white matter function and inflammation. Male C57Bl/6J mice underwent bilateral common carotid artery stenosis and white matter function was assessed at seven days with electrophysiology in response to evoked compound action potentials (CAPs) in the corpus callosum. The peak latency of CAPs and axonal refractoriness was increased following hypoperfusion, indicating a marked functional impairment in white matter, which was paralleled by axonal and myelin pathology and increased density and numbers of microglia/macrophages. The functional impairment in peak latency was significantly correlated with increased microglia/macrophages. Dimethyl fumarate (DMF; 100 mg/kg), a drug with anti-inflammatory properties, was found to reduce peak latency but not axonal refractoriness. DMF had no effect on hypoperfusion-induced axonal and myelin pathology. The density of microglia/macrophages was significantly increased in vehicle-treated hypoperfused mice, whereas DMF-treated hypoperfused mice had similar levels to that of sham-treated mice. The study suggests that increased microglia/macrophages following cerebral hypoperfusion contributes to the functional impairment in white matter that may be amenable to modulation by DMF.
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Affiliation(s)
- Jill H Fowler
- 1 Centre for Neuroregeneration, University of Edinburgh, Edinburgh, UK
| | - Jamie McQueen
- 1 Centre for Neuroregeneration, University of Edinburgh, Edinburgh, UK.,2 Centre for Integrative Physiology, University of Edinburgh, Edinburgh, UK
| | - Philip R Holland
- 1 Centre for Neuroregeneration, University of Edinburgh, Edinburgh, UK.,3 Current Address: Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
| | - Yasmina Manso
- 1 Centre for Neuroregeneration, University of Edinburgh, Edinburgh, UK.,4 Current Address: Developmental Neurobiology and Regeneration Lab, Parc Científic de Barcelona, Spain
| | - Martina Marangoni
- 1 Centre for Neuroregeneration, University of Edinburgh, Edinburgh, UK.,5 Current Address: Department of Health Sciences, University of Florence, Florence, Italy
| | - Fiona Scott
- 1 Centre for Neuroregeneration, University of Edinburgh, Edinburgh, UK
| | - Emma Chisholm
- 1 Centre for Neuroregeneration, University of Edinburgh, Edinburgh, UK
| | | | - Giles E Hardingham
- 2 Centre for Integrative Physiology, University of Edinburgh, Edinburgh, UK.,7 The UK Dementia Research Institute at The University of Edinburgh
| | - Karen Horsburgh
- 1 Centre for Neuroregeneration, University of Edinburgh, Edinburgh, UK.,8 Centre for Cognitive Ageing and Cognitive Epidemiology, University of Edinburgh, Edinburgh, UK
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17
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Chronic cerebral hypoperfusion: a key mechanism leading to vascular cognitive impairment and dementia. Closing the translational gap between rodent models and human vascular cognitive impairment and dementia. Clin Sci (Lond) 2017; 131:2451-2468. [PMID: 28963120 DOI: 10.1042/cs20160727] [Citation(s) in RCA: 225] [Impact Index Per Article: 32.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2017] [Revised: 08/28/2017] [Accepted: 09/04/2017] [Indexed: 12/15/2022]
Abstract
Increasing evidence suggests that vascular risk factors contribute to neurodegeneration, cognitive impairment and dementia. While there is considerable overlap between features of vascular cognitive impairment and dementia (VCID) and Alzheimer's disease (AD), it appears that cerebral hypoperfusion is the common underlying pathophysiological mechanism which is a major contributor to cognitive decline and degenerative processes leading to dementia. Sustained cerebral hypoperfusion is suggested to be the cause of white matter attenuation, a key feature common to both AD and dementia associated with cerebral small vessel disease (SVD). White matter changes increase the risk for stroke, dementia and disability. A major gap has been the lack of mechanistic insights into the evolution and progress of VCID. However, this gap is closing with the recent refinement of rodent models which replicate chronic cerebral hypoperfusion. In this review, we discuss the relevance and advantages of these models in elucidating the pathogenesis of VCID and explore the interplay between hypoperfusion and the deposition of amyloid β (Aβ) protein, as it relates to AD. We use examples of our recent investigations to illustrate the utility of the model in preclinical testing of candidate drugs and lifestyle factors. We propose that the use of such models is necessary for tackling the urgently needed translational gap from preclinical models to clinical treatments.
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18
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Chronic cerebral hypoperfusion alters amyloid-β peptide pools leading to cerebral amyloid angiopathy, microinfarcts and haemorrhages in Tg-SwDI mice. Clin Sci (Lond) 2017; 131:2109-2123. [PMID: 28667120 DOI: 10.1042/cs20170962] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2017] [Revised: 06/22/2017] [Accepted: 06/29/2017] [Indexed: 02/07/2023]
Abstract
Cerebral hypoperfusion is an early feature of Alzheimer's disease (AD) that influences the progression from mild cognitive impairment to dementia. Understanding the mechanism is of critical importance in the search for new effective therapies. We hypothesized that cerebral hypoperfusion promotes the accumulation of amyloid-β (Aβ) and degenerative changes in the brain and is a potential mechanism contributing to development of dementia. To address this, we studied the effects of chronic cerebral hypoperfusion induced by bilateral carotid artery stenosis on Aβ peptide pools in a transgenic mouse model of AD (transgenic mice with Swedish, Dutch and Iowa mutations in human amyloid precursor protein (APP) (Tg-SwDI)). Cerebrovascular integrity was characterized by quantifying the occurrence of microinfarcts and haemorrhages and compared with wild-type mice without Aβ. A significant increase in soluble Aβ peptides (Aβ40/42) was detected after 1 month of hypoperfusion in the parenchyma in parallel with elevated APP and APP proteolytic products. Following 3 months, a significant increase in insoluble Aβ40/42 was determined in the parenchyma and vasculature. Microinfarct load was significantly increased in the Tg-SwDI as compared with wild-type mice and further exacerbated by hypoperfusion at 1 and 3 months. In addition, the number of Tg-SwDI hypoperfused mice with haemorrhages was increased compared with hypoperfused wild-type mice. Soluble parenchymal Aβ was associated with elevated NADPH oxidase-2 (NOX2) which was exacerbated by 1-month hypoperfusion. We suggest that in response to hypoperfusion, increased Aβ production/deposition may contribute to degenerative processes by triggering oxidative stress promoting cerebrovascular disruption and the development of microinfarcts.
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19
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Manso Y, Holland PR, Kitamura A, Szymkowiak S, Duncombe J, Hennessy E, Searcy JL, Marangoni M, Randall AD, Brown JT, McColl BW, Horsburgh K. Minocycline reduces microgliosis and improves subcortical white matter function in a model of cerebral vascular disease. Glia 2017; 66:34-46. [PMID: 28722234 DOI: 10.1002/glia.23190] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2016] [Revised: 06/26/2017] [Accepted: 06/27/2017] [Indexed: 12/19/2022]
Abstract
Chronic cerebral hypoperfusion is a key mechanism associated with white matter disruption in cerebral vascular disease and dementia. In a mouse model relevant to studying cerebral vascular disease, we have previously shown that cerebral hypoperfusion disrupts axon-glial integrity and the distribution of key paranodal and internodal proteins in subcortical myelinated axons. This disruption of myelinated axons is accompanied by increased microglia and cognitive decline. The aim of the present study was to investigate whether hypoperfusion impairs the functional integrity of white matter, its relation with axon-glial integrity and microglial number, and whether by targeting microglia these effects can be improved. We show that in response to increasing durations of hypoperfusion, the conduction velocity of myelinated fibres in the corpus callosum is progressively reduced and that paranodal and internodal axon-glial integrity is disrupted. The number of microglial cells increases in response to hypoperfusion and correlates with disrupted paranodal and internodal integrity and reduced conduction velocities. Further minocycline, a proposed anti-inflammatory and microglia inhibitor, restores white matter function related to a reduction in the number of microglia. The study suggests that microglial activation contributes to the structural and functional alterations of myelinated axons induced by cerebral hypoperfusion and that dampening microglia numbers/proliferation should be further investigated as potential therapeutic benefit in cerebral vascular disease.
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Affiliation(s)
- Yasmina Manso
- Centre for Neuroregeneration, University of Edinburgh, Chancellor's Building, 49 Little France Crescent, Edinburgh, EH16 4SB, United Kingdom
| | - Philip R Holland
- Centre for Neuroregeneration, University of Edinburgh, Chancellor's Building, 49 Little France Crescent, Edinburgh, EH16 4SB, United Kingdom
| | - Akihiro Kitamura
- Centre for Neuroregeneration, University of Edinburgh, Chancellor's Building, 49 Little France Crescent, Edinburgh, EH16 4SB, United Kingdom
| | - Stefan Szymkowiak
- University of Edinburgh, The Roslin Institute, Easter Bush, Edinburgh, EH25 9RG
| | - Jessica Duncombe
- Centre for Neuroregeneration, University of Edinburgh, Chancellor's Building, 49 Little France Crescent, Edinburgh, EH16 4SB, United Kingdom
| | - Edel Hennessy
- Centre for Neuroregeneration, University of Edinburgh, Chancellor's Building, 49 Little France Crescent, Edinburgh, EH16 4SB, United Kingdom
| | - James L Searcy
- Centre for Neuroregeneration, University of Edinburgh, Chancellor's Building, 49 Little France Crescent, Edinburgh, EH16 4SB, United Kingdom
| | - Martina Marangoni
- Centre for Neuroregeneration, University of Edinburgh, Chancellor's Building, 49 Little France Crescent, Edinburgh, EH16 4SB, United Kingdom
| | - Andrew D Randall
- University of Exeter Medical School, University of Exeter, Exeter, UK
| | - Jon T Brown
- University of Exeter Medical School, University of Exeter, Exeter, UK
| | - Barry W McColl
- University of Edinburgh, The Roslin Institute, Easter Bush, Edinburgh, EH25 9RG.,UK Dementia Research Institute, University of Edinburgh, Edinburgh Medical School, 47 Little France Crescent, Edinburgh, EH16 4TJ, UK
| | - Karen Horsburgh
- Centre for Neuroregeneration, University of Edinburgh, Chancellor's Building, 49 Little France Crescent, Edinburgh, EH16 4SB, United Kingdom
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20
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Kitamura A, Manso Y, Duncombe J, Searcy J, Koudelka J, Binnie M, Webster S, Lennen R, Jansen M, Marshall I, Ihara M, Kalaria RN, Horsburgh K. Long-term cilostazol treatment reduces gliovascular damage and memory impairment in a mouse model of chronic cerebral hypoperfusion. Sci Rep 2017; 7:4299. [PMID: 28655874 PMCID: PMC5487324 DOI: 10.1038/s41598-017-04082-0] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2017] [Accepted: 05/09/2017] [Indexed: 01/07/2023] Open
Abstract
Chronic cerebral hypoperfusion is a major cause of age-related vascular cognitive impairment. A well-characterised mouse model has shown that hypoperfusion results in gliovascular and white matter damage and impaired spatial working memory. In this study, we assessed whether cilostazol, a phosphodiesterase III inhibitor, could protect against these changes. Adult, male C57Bl/6J mice were subjected to bilateral common carotid artery stenosis or a sham operation and fed normal or cilostazol diet for three months. Cilostazol treatment reduced the impairment in working memory and white matter function after hypoperfusion. Endothelial adhesion molecules and gliosis, increased after hypoperfusion, were ameliorated with cilostazol treatment. Interestingly, the improvement in working memory was closely correlated with reduced microglia and endothelial adhesion molecules. Further, the number of stroke lesions after hypoperfusion was reduced in the cilostazol-treated group. Altogether cilostazol showed potential to ameliorate the gliovascular damage and working memory impairments after hypoperfusion possibly via endothelial protection supporting its potential use in the treatment of vascular cognitive impairment.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | - Masafumi Ihara
- National Cerebral and Cardiovascular Center, Osaka, Japan
| | - Raj N Kalaria
- Institute of Neuroscience, Newcastle University, Newcastle, UK
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21
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Struys T, Govaerts K, Oosterlinck W, Casteels C, Bronckaers A, Koole M, Van Laere K, Herijgers P, Lambrichts I, Himmelreich U, Dresselaers T. In vivo evidence for long-term vascular remodeling resulting from chronic cerebral hypoperfusion in mice. J Cereb Blood Flow Metab 2017; 37:726-739. [PMID: 26994041 PMCID: PMC5381461 DOI: 10.1177/0271678x16638349] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
We have characterized both acute and long-term vascular and metabolic effects of unilateral common carotid artery occlusion in mice by in vivo magnetic resonance imaging and positron emission tomography. This common carotid artery occlusion model induces chronic cerebral hypoperfusion and is therefore relevant to both preclinical stroke studies, where it serves as a control condition for a commonly used mouse model of ischemic stroke, and neurodegeneration, as chronic hypoperfusion is causative to cognitive decline. By using perfusion magnetic resonance imaging, we demonstrate that under isoflurane anesthesia, cerebral perfusion levels recover gradually over one month. This recovery is paralleled by an increase in lumen diameter and altered tortuosity of the contralateral internal carotid artery at one year post-ligation as derived from magnetic resonance angiography data. Under urethane/α-chloralose anesthesia, no acute perfusion differences are observed, but the vascular response capacity to hypercapnia is found to be compromised. These hemispheric perfusion alterations are confirmed by water [15O]-H2O positron emission tomography. Glucose metabolism ([18F]-FDG positron emission tomography) or white matter organization (diffusion-weighted magnetic resonance imaging) did not show any significant alterations. In conclusion, permanent unilateral common carotid artery occlusion results in acute and long-term vascular remodeling, which may have immediate consequences for animal models of stroke but also vascular dementia.
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Affiliation(s)
- Tom Struys
- 1 Biomedical Research Institute - Morphology Research Group, Hasselt University, Hasselt, Belgium
| | - Kristof Govaerts
- 2 Biomedical MRI Unit - MoSAIC, Department of Imaging & Pathology, KU Leuven, Leuven, Belgium
| | - Wouter Oosterlinck
- 3 Research Unit of Experimental Cardiac Surgery, Department of Cardiovascular Sciences, KU Leuven, Leuven, Belgium
| | - Cindy Casteels
- 4 Nuclear Medicine - MoSAIC, Department of Imaging & Pathology, KU Leuven, Leuven, Belgium
| | - Annelies Bronckaers
- 1 Biomedical Research Institute - Morphology Research Group, Hasselt University, Hasselt, Belgium
| | - Michel Koole
- 4 Nuclear Medicine - MoSAIC, Department of Imaging & Pathology, KU Leuven, Leuven, Belgium
| | - Koen Van Laere
- 4 Nuclear Medicine - MoSAIC, Department of Imaging & Pathology, KU Leuven, Leuven, Belgium
| | - Paul Herijgers
- 3 Research Unit of Experimental Cardiac Surgery, Department of Cardiovascular Sciences, KU Leuven, Leuven, Belgium
| | - Ivo Lambrichts
- 1 Biomedical Research Institute - Morphology Research Group, Hasselt University, Hasselt, Belgium
| | - Uwe Himmelreich
- 2 Biomedical MRI Unit - MoSAIC, Department of Imaging & Pathology, KU Leuven, Leuven, Belgium
| | - Tom Dresselaers
- 2 Biomedical MRI Unit - MoSAIC, Department of Imaging & Pathology, KU Leuven, Leuven, Belgium.,5 Radiology, University Hospitals, Leuven, Belgium
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22
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Boehm-Sturm P, Füchtemeier M, Foddis M, Mueller S, Trueman RC, Zille M, Rinnenthal JL, Kypraios T, Shaw L, Dirnagl U, Farr TD. Neuroimaging Biomarkers Predict Brain Structural Connectivity Change in a Mouse Model of Vascular Cognitive Impairment. Stroke 2017; 48:468-475. [PMID: 28070001 PMCID: PMC5266417 DOI: 10.1161/strokeaha.116.014394] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2016] [Revised: 11/01/2016] [Accepted: 11/28/2016] [Indexed: 12/11/2022]
Abstract
BACKGROUND AND PURPOSE Chronic hypoperfusion in the mouse brain has been suggested to mimic aspects of vascular cognitive impairment, such as white matter damage. Although this model has attracted attention, our group has struggled to generate a reliable cognitive and pathological phenotype. This study aimed to identify neuroimaging biomarkers of brain pathology in aged, more severely hypoperfused mice. METHODS We used magnetic resonance imaging to characterize brain degeneration in mice hypoperfused by refining the surgical procedure to use the smallest reported diameter microcoils (160 μm). RESULTS Acute cerebral blood flow decreases were observed in the hypoperfused group that recovered over 1 month and coincided with arterial remodeling. Increasing hypoperfusion resulted in a reduction in spatial learning abilities in the water maze that has not been previously reported. We were unable to observe severe white matter damage with histology, but a novel approach to analyze diffusion tensor imaging data, graph theory, revealed substantial reorganization of the hypoperfused brain network. A logistic regression model from the data revealed that 3 network parameters were particularly efficient at predicting group membership (global and local efficiency and degrees), and clustering coefficient was correlated with performance in the water maze. CONCLUSIONS Overall, these findings suggest that, despite the autoregulatory abilities of the mouse brain to compensate for a sudden decrease in blood flow, there is evidence of change in the brain networks that can be used as neuroimaging biomarkers to predict outcome.
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Affiliation(s)
- Philipp Boehm-Sturm
- From the Department of Experimental Neurology, Center for Stroke Research Berlin (CSB) (P.B.-S., M.F., M.F., S.M., M.Z., U.D., T.D.F.), Charité Core Facility 7T Experimental MRIs (P.B.-S., S.M.), Department of Neuropathology (J.L.R.), and German Centre for Neurodegenerative Diseases (DZNE), Berlin site (M.F., U.D.), Charité University Medicine Berlin, Germany; and School of Life Sciences (R.C.T., T.D.F.) and School of Mathematics (T.K., L.S.), University of Nottingham, United Kingdom
| | - Martina Füchtemeier
- From the Department of Experimental Neurology, Center for Stroke Research Berlin (CSB) (P.B.-S., M.F., M.F., S.M., M.Z., U.D., T.D.F.), Charité Core Facility 7T Experimental MRIs (P.B.-S., S.M.), Department of Neuropathology (J.L.R.), and German Centre for Neurodegenerative Diseases (DZNE), Berlin site (M.F., U.D.), Charité University Medicine Berlin, Germany; and School of Life Sciences (R.C.T., T.D.F.) and School of Mathematics (T.K., L.S.), University of Nottingham, United Kingdom
| | - Marco Foddis
- From the Department of Experimental Neurology, Center for Stroke Research Berlin (CSB) (P.B.-S., M.F., M.F., S.M., M.Z., U.D., T.D.F.), Charité Core Facility 7T Experimental MRIs (P.B.-S., S.M.), Department of Neuropathology (J.L.R.), and German Centre for Neurodegenerative Diseases (DZNE), Berlin site (M.F., U.D.), Charité University Medicine Berlin, Germany; and School of Life Sciences (R.C.T., T.D.F.) and School of Mathematics (T.K., L.S.), University of Nottingham, United Kingdom
| | - Susanne Mueller
- From the Department of Experimental Neurology, Center for Stroke Research Berlin (CSB) (P.B.-S., M.F., M.F., S.M., M.Z., U.D., T.D.F.), Charité Core Facility 7T Experimental MRIs (P.B.-S., S.M.), Department of Neuropathology (J.L.R.), and German Centre for Neurodegenerative Diseases (DZNE), Berlin site (M.F., U.D.), Charité University Medicine Berlin, Germany; and School of Life Sciences (R.C.T., T.D.F.) and School of Mathematics (T.K., L.S.), University of Nottingham, United Kingdom
| | - Rebecca C Trueman
- From the Department of Experimental Neurology, Center for Stroke Research Berlin (CSB) (P.B.-S., M.F., M.F., S.M., M.Z., U.D., T.D.F.), Charité Core Facility 7T Experimental MRIs (P.B.-S., S.M.), Department of Neuropathology (J.L.R.), and German Centre for Neurodegenerative Diseases (DZNE), Berlin site (M.F., U.D.), Charité University Medicine Berlin, Germany; and School of Life Sciences (R.C.T., T.D.F.) and School of Mathematics (T.K., L.S.), University of Nottingham, United Kingdom
| | - Marietta Zille
- From the Department of Experimental Neurology, Center for Stroke Research Berlin (CSB) (P.B.-S., M.F., M.F., S.M., M.Z., U.D., T.D.F.), Charité Core Facility 7T Experimental MRIs (P.B.-S., S.M.), Department of Neuropathology (J.L.R.), and German Centre for Neurodegenerative Diseases (DZNE), Berlin site (M.F., U.D.), Charité University Medicine Berlin, Germany; and School of Life Sciences (R.C.T., T.D.F.) and School of Mathematics (T.K., L.S.), University of Nottingham, United Kingdom
| | - Jan Leo Rinnenthal
- From the Department of Experimental Neurology, Center for Stroke Research Berlin (CSB) (P.B.-S., M.F., M.F., S.M., M.Z., U.D., T.D.F.), Charité Core Facility 7T Experimental MRIs (P.B.-S., S.M.), Department of Neuropathology (J.L.R.), and German Centre for Neurodegenerative Diseases (DZNE), Berlin site (M.F., U.D.), Charité University Medicine Berlin, Germany; and School of Life Sciences (R.C.T., T.D.F.) and School of Mathematics (T.K., L.S.), University of Nottingham, United Kingdom
| | - Theodore Kypraios
- From the Department of Experimental Neurology, Center for Stroke Research Berlin (CSB) (P.B.-S., M.F., M.F., S.M., M.Z., U.D., T.D.F.), Charité Core Facility 7T Experimental MRIs (P.B.-S., S.M.), Department of Neuropathology (J.L.R.), and German Centre for Neurodegenerative Diseases (DZNE), Berlin site (M.F., U.D.), Charité University Medicine Berlin, Germany; and School of Life Sciences (R.C.T., T.D.F.) and School of Mathematics (T.K., L.S.), University of Nottingham, United Kingdom
| | - Laurence Shaw
- From the Department of Experimental Neurology, Center for Stroke Research Berlin (CSB) (P.B.-S., M.F., M.F., S.M., M.Z., U.D., T.D.F.), Charité Core Facility 7T Experimental MRIs (P.B.-S., S.M.), Department of Neuropathology (J.L.R.), and German Centre for Neurodegenerative Diseases (DZNE), Berlin site (M.F., U.D.), Charité University Medicine Berlin, Germany; and School of Life Sciences (R.C.T., T.D.F.) and School of Mathematics (T.K., L.S.), University of Nottingham, United Kingdom
| | - Ulrich Dirnagl
- From the Department of Experimental Neurology, Center for Stroke Research Berlin (CSB) (P.B.-S., M.F., M.F., S.M., M.Z., U.D., T.D.F.), Charité Core Facility 7T Experimental MRIs (P.B.-S., S.M.), Department of Neuropathology (J.L.R.), and German Centre for Neurodegenerative Diseases (DZNE), Berlin site (M.F., U.D.), Charité University Medicine Berlin, Germany; and School of Life Sciences (R.C.T., T.D.F.) and School of Mathematics (T.K., L.S.), University of Nottingham, United Kingdom
| | - Tracy D Farr
- From the Department of Experimental Neurology, Center for Stroke Research Berlin (CSB) (P.B.-S., M.F., M.F., S.M., M.Z., U.D., T.D.F.), Charité Core Facility 7T Experimental MRIs (P.B.-S., S.M.), Department of Neuropathology (J.L.R.), and German Centre for Neurodegenerative Diseases (DZNE), Berlin site (M.F., U.D.), Charité University Medicine Berlin, Germany; and School of Life Sciences (R.C.T., T.D.F.) and School of Mathematics (T.K., L.S.), University of Nottingham, United Kingdom.
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23
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Substantial Reduction of Parenchymal Cerebral Blood Flow in Mice with Bilateral Common Carotid Artery Stenosis. Sci Rep 2016; 6:32179. [PMID: 27535801 PMCID: PMC4989493 DOI: 10.1038/srep32179] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2016] [Accepted: 08/03/2016] [Indexed: 01/06/2023] Open
Abstract
The bilateral common carotid artery stenosis (BCAS) mouse model, which replicates chronic cerebral hypoperfusion and white matter ischemic lesions, is considered to model some aspects of vascular cognitive impairment. Cerebral blood flow (CBF) changes in the brain surface post-BCAS have been demonstrated by laser speckle flowmetry, but CBF levels in the brain parenchyma remain unknown. Adult C57BL/6J male mice were subjected to BCAS using external microcoils. Brain magnetic resonance angiography (MRA) was conducted to visualize the intracranial main arteries while arterial spin labeling (ASL) was used to measure cortical and subcortical parenchymal CBF levels before and after BCAS. Brain MRA showed anterior circulation flow was substantially decreased until 14 days post-BCAS, which gradually but incompletely recovered over the following 14 days, with probable growth of collaterals from the posterior cerebral artery. ASL showed that cortical and subcortical parenchymal CBF remained decreased at approximately 50% of the baseline level during 1 and 14 days post-BCAS, recovering to approximately 70% at day 28. CBF levels in the parenchyma were lower than the cortical superficial region in the BCAS model and remained decreased without recovery during the first 2 weeks post-BCAS. These results suggest that the BCAS model reliably replicates chronic cerebral hypoperfusion.
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Sitagliptin attenuated brain damage and cognitive impairment in mice with chronic cerebral hypo-perfusion through suppressing oxidative stress and inflammatory reaction. J Hypertens 2016; 33:1001-13. [PMID: 25689400 DOI: 10.1097/hjh.0000000000000529] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
BACKGROUND Sitagliptin, a new antidiabetic drug that inhibits dipeptidyl peptidase (DPP)-4 enzyme activity, has been reported to possess neuroprotective property. We tested the protective effects of sitagliptin against chronic cerebral hypoperfusion (CHP) in mice after bilateral carotid artery stenosis (BCAS). METHOD Thirty C57BL/6 mice were divided into three groups: sham control (n = 10), CHP (n = 10) and CHP-sitagliptin (orally 600 mg/kg/day) (n = 10). Working memory was assessed with novel-object recognition test. MRI was performed at day 0 and day 90 after BCAS procedure prior to sacrifice. RESULTS Immunohistochemical (IHC) staining showed significantly enhanced white matter lesions, microglia activation and astrocytosis of white matter in CHP group than in sham control, but the changes were significantly suppressed after sitagliptin treatment (all P < 0.01). The mRNA expressions of inflammatory [tumour necrosis factor-alpha (TNF-α), monocyte chemoattractant protein (MCP-1) and matrix metalloproteinase (MMP)-2] and apoptotic (Bax) biomarkers showed an identical pattern, whereas the anti-inflammatory (interleukin, IL-10) and antiapoptotic (Bcl-2) biomarkers showed an opposite pattern compared with that of IHC among all groups (all P < 0.01). The protein expressions of oxidative stress (NOX-I, NOX-II, nitrotyrosin, oxidized protein), inflammatory [nuclear factor-kappa B (NF-κB), TNF-α and MMP-2], apoptotic [mitochondrial Bax, cleaved poly(ADP-ribose) polymerase (PARP)] and DNA-damage (γ-H2AX) markers showed an identical pattern, while expression pattern of antiapoptotic marker (Bcl-2) was opposite to that of IHC (all P < 0.01). Glycogen-like peptide-1 receptor protein expression progressively increased from sham control to CHP-sitagliptin (P < 0.01). The short-term working-memory loss and MRI/diffusion tensor imaging (DTI) showed a pattern identical to that of IHC in all groups (all P < 0.01). CONCLUSION Sitagliptin protected against cognitive impairment and brain damage in a murine CHP model.
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25
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Wu M, Kumar A, Yang S. Development and aging of superficial white matter myelin from young adulthood to old age: Mapping by vertex-based surface statistics (VBSS). Hum Brain Mapp 2016; 37:1759-69. [PMID: 26955787 DOI: 10.1002/hbm.23134] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2015] [Revised: 01/07/2016] [Accepted: 01/26/2016] [Indexed: 11/06/2022] Open
Abstract
Superficial white matter (SWM) lies immediately beneath cortical gray matter and consists primarily of short association fibers. The characteristics of SWM and its development and aging were seldom examined in the literature and warrant further investigation. Magnetization transfer imaging is sensitive to myelin changes in the white matter. Using an innovative multimodal imaging analysis approach, vertex-based surface statistics (VBSS), the current study vertexwise mapped age-related changes of magnetization transfer ratio (MTR) in SWM from young adulthood to old age (30-85 years, N = 66). Results demonstrated regionally selective and temporally heterochronologic changes of SWM MTR with age, including (1) inverted U-shaped trajectories of SWM MTR in the rostral middle frontal, medial temporal, and temporoparietal regions, suggesting continuing myelination and protracted maturation till age 40-50 years and accelerating demyelination at age 60 and beyond, (2) linear decline of SWM MTR in the middle and superior temporal, and pericalcarine areas, indicating early maturation and less acceleration in age-related degeneration, and (3) no significant changes of SWM MTR in the primary motor, somatosensory and auditory regions, suggesting resistance to age-related deterioration. We did not observe similar patterns of changes in cortical thickness in our sample, suggesting the observed SWM MTR changes are not due to cortical atrophy. Hum Brain Mapp 37:1759-1769, 2016. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Minjie Wu
- Department of Psychiatry, University of Illinois at Chicago, Chicago, Illinois
| | - Anand Kumar
- Department of Psychiatry, University of Illinois at Chicago, Chicago, Illinois
| | - Shaolin Yang
- Department of Psychiatry, University of Illinois at Chicago, Chicago, Illinois.,Department of Radiology, University of Illinois at Chicago, Chicago, Illinois.,Department of Bioengineering, University of Illinois at Chicago, Chicago, Illinois
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26
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Schmidt R, Seiler S, Loitfelder M. Longitudinal change of small-vessel disease-related brain abnormalities. J Cereb Blood Flow Metab 2016; 36:26-39. [PMID: 25899293 PMCID: PMC4758559 DOI: 10.1038/jcbfm.2015.72] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/20/2015] [Accepted: 03/16/2015] [Indexed: 12/31/2022]
Abstract
Knowledge about the longitudinal change of cerebral small-vessel disease–related magnetic resonance imaging abnormalities increases our pathophysiologic understanding of cerebral microangiopathy. The change of specific lesion types may also serve as secondary surrogate endpoint in clinical trials. A surrogate endpoint needs to progress fast enough to allow monitoring of treatment effects within a reasonable time period, and change of the brain abnormality needs to be correlated with clinical change. Confluent white matter lesions show fast progression and correlations with cognitive decline. Thus, the change of confluent white matter lesions may be used as a surrogate marker in proof-of-concept trials with small patient numbers needed to show treatment effects on lesion progression. Nonetheless if the expected change in cognitive performance resulting from treatment effects on lesion progression is used as outcome, the sample size needed to show small to moderate treatment effects becomes very large. Lacunes may also fulfill the prerequisites of a surrogate marker, but in the general population the incidence of lacunes over short observational periods is small. For other small-vessel disease–related brain abnormalities including microbleeds and microstructural changes in normal-appearing white matter longitudinal change and correlations with clinical decline is not yet fully determined.
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Affiliation(s)
- Reinhold Schmidt
- Department of Neurology, Medical University of Graz, Graz, Austria
| | - Stephan Seiler
- Department of Neurology, Medical University of Graz, Graz, Austria
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27
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Holland PR, Searcy JL, Salvadores N, Scullion G, Chen G, Lawson G, Scott F, Bastin ME, Ihara M, Kalaria R, Wood ER, Smith C, Wardlaw JM, Horsburgh K. Gliovascular disruption and cognitive deficits in a mouse model with features of small vessel disease. J Cereb Blood Flow Metab 2015; 35:1005-14. [PMID: 25669904 PMCID: PMC4640247 DOI: 10.1038/jcbfm.2015.12] [Citation(s) in RCA: 77] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/29/2014] [Revised: 01/12/2015] [Accepted: 01/13/2015] [Indexed: 01/23/2023]
Abstract
Cerebral small vessel disease (SVD) is a major cause of age-related cognitive impairment and dementia. The pathophysiology of SVD is not well understood and is hampered by a limited range of relevant animal models. Here, we describe gliovascular alterations and cognitive deficits in a mouse model of sustained cerebral hypoperfusion with features of SVD (microinfarcts, hemorrhage, white matter disruption) induced by bilateral common carotid stenosis. Multiple features of SVD were determined on T2-weighted and diffusion-tensor magnetic resonance imaging scans and confirmed by pathologic assessment. These features, which were absent in sham controls, included multiple T2-hyperintense infarcts and T2-hypointense hemosiderin-like regions in subcortical nuclei plus increased cerebral atrophy compared with controls. Fractional anisotropy was also significantly reduced in several white matter structures including the corpus callosum. Investigation of gliovascular changes revealed a marked increase in microvessel diameter, vascular wall disruption, fibrinoid necrosis, hemorrhage, and blood-brain barrier alterations. Widespread reactive gliosis, including displacement of the astrocytic water channel, aquaporin 4, was observed. Hypoperfused mice also demonstrated deficits in spatial working and reference memory tasks. Overall, gliovascular disruption is a prominent feature of this mouse, which could provide a useful model for early-phase testing of potential SVD treatment strategies.
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Affiliation(s)
- Philip R Holland
- Centre for Neuroregeneration, Centre for Cognitive Ageing and Cognitive Epidemiology, University of Edinburgh, Edinburgh, UK
| | - James L Searcy
- Centre for Neuroregeneration, University of Edinburgh, Edinburgh, UK
| | | | - Gillian Scullion
- Centre for Neuroregeneration, University of Edinburgh, Edinburgh, UK
| | - Guiquan Chen
- Centre for Neuroregeneration, University of Edinburgh, Edinburgh, UK
| | - Greig Lawson
- Centre for Neuroregeneration, University of Edinburgh, Edinburgh, UK
| | - Fiona Scott
- Centre for Neuroregeneration, University of Edinburgh, Edinburgh, UK
| | - Mark E Bastin
- Centre for Cognitive Ageing and Cognitive Epidemiology, Scottish Imaging Network, A Platform for Scientific Collaboration (SINAPSE), Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, UK
| | - Masafumi Ihara
- Department of Stroke and Cerebrovascular Diseases, National Cerebral and Cardiovascular Center Hospital, Osaka, Japan
| | - Rajesh Kalaria
- Institute of Neuroscience, Newcastle University, Campus for Ageing and Vitality, Newcastle upon Tyne, UK
| | - Emma R Wood
- Centre for Cognitive and Neural Systems and Centre for Cognitive Ageing and Cognitive Epidemiology, University of Edinburgh, Edinburgh, UK
| | - Colin Smith
- Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, UK
| | - Joanna M Wardlaw
- Centre for Cognitive Ageing and Cognitive Epidemiology, Scottish Imaging Network, A Platform for Scientific Collaboration (SINAPSE), Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, UK
| | - Karen Horsburgh
- Centre for Neuroregeneration, Centre for Cognitive Ageing and Cognitive Epidemiology, University of Edinburgh, Edinburgh, UK
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Widya RL, Kroft LJM, Altmann-Schneider I, van den Berg-Huysmans AA, van der Bijl N, de Roos A, Lamb HJ, van Buchem MA, Slagboom PE, van Heemst D, van der Grond J. Visceral adipose tissue is associated with microstructural brain tissue damage. Obesity (Silver Spring) 2015; 23:1092-6. [PMID: 25919926 DOI: 10.1002/oby.21048] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/02/2014] [Accepted: 01/18/2015] [Indexed: 11/05/2022]
Abstract
OBJECTIVE Obesity has been associated with microstructural brain tissue damage. Different fat compartments demonstrate different metabolic and endocrine behaviors. The aim was to investigate the individual associations between abdominal visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) and microstructural integrity in the brain. METHODS This study comprised 243 subjects aged 65.4 ± 6.7 years. The associations between abdominal VAT and SAT, assessed by CT, and magnetization transfer imaging markers of brain microstructure for gray and white matter were analyzed and adjusted for confounding factors. RESULTS VAT was associated with normalized MTR peak height in gray (β -0.216) and white matter (β -0.240) (both P < 0.01) after adjustment for confounding factors. After adjustment for sex, age, and descent, SAT was associated with normalized MTR peak height in gray and white matter, but not after additional correction for BMI, hypertension, current smoking, statin use, and type 2 diabetes (respectively, β -0.055 and β 0.035, both P > 0.05). Stepwise linear regression analysis showed that only VAT was associated with normalized MTR peak height in gray and white matter (both P < 0.001). CONCLUSIONS Our data indicate that increased abdominal VAT rather than SAT is associated with microstructural brain tissue damage in elderly individuals.
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Affiliation(s)
- Ralph L Widya
- Department of Radiology, Leiden University Medical Center, Leiden, The Netherlands
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Altmann-Schneider I, de Craen AJM, van den Berg-Huysmans AA, Slagboom P, Westendorp RG, van Buchem MA, van der Grond J. An in vivo study on brain microstructure in biological and chronological ageing. PLoS One 2015; 10:e0120778. [PMID: 25807271 PMCID: PMC4373824 DOI: 10.1371/journal.pone.0120778] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2014] [Accepted: 01/27/2015] [Indexed: 11/28/2022] Open
Abstract
This study aimed to investigate whether magnetization transfer imaging (MTI) parameters of cortical gray and white matter and subcortical gray matter structures differ between subjects enriched for human familial longevity and control subjects to provide a thorough description of the brain phenotype of familial longevity. Moreover, we aimed to describe cerebral ageing effects on MTI parameters in an elderly cohort. All subjects were included from the Leiden Longevity Study and underwent 3 Tesla MTI of the brain. In total, 183 offspring of nonagenarian siblings, who are enriched for familial factors of longevity, were contrasted with 163 environmentally and age-matched controls. No differences in cortical and subcortical gray matter and white matter MTI parameters were found between offspring and control subjects using histogram-based and voxel-wise analyses. Cortical gray matter and white matter MTI parameters decreased with increasing chronological age (all p < 0.001). Decrease of white matter magnetization transfer ratio (MTR) was homogeneous throughout the whole mean white matter skeleton except for parts of the callosal splenium and partly the posterior limb of the internal capsule and superior region of the corona radiata (p < 0.05). Mean MTR of subcortical gray matter structures decreased with increasing age (p amygdala, caudate nucleus and putamen < 0.001; p pallidum = 0.001, p thalamus = 0.002). In conclusion, the brain phenotype of human familial longevity is - at a mean age of 66 years - not characterized by preserved macromolecular brain tissue integrity.
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Affiliation(s)
- Irmhild Altmann-Schneider
- Department of Radiology, Leiden University Medical Center, Leiden, The Netherlands
- Department of Gerontology and Geriatrics, Leiden University Medical Center, Leiden, The Netherlands
- Netherlands Consortium for Healthy Ageing, Leiden, The Netherlands
| | - Anton J. M. de Craen
- Department of Gerontology and Geriatrics, Leiden University Medical Center, Leiden, The Netherlands
- Netherlands Consortium for Healthy Ageing, Leiden, The Netherlands
| | | | - Pieternella Slagboom
- Department of Molecular Epidemiology, Leiden University Medical Center, Leiden, The Netherlands
- Netherlands Consortium for Healthy Ageing, Leiden, The Netherlands
| | - Rudi G.J. Westendorp
- Department of Gerontology and Geriatrics, Leiden University Medical Center, Leiden, The Netherlands
- Netherlands Consortium for Healthy Ageing, Leiden, The Netherlands
- Faculty of Health and Medical Sciences, Department of Public Health, University of Copenhagen, Copenhagen, Denmark
| | - Mark A. van Buchem
- Department of Radiology, Leiden University Medical Center, Leiden, The Netherlands
- Netherlands Consortium for Healthy Ageing, Leiden, The Netherlands
| | - Jeroen van der Grond
- Department of Radiology, Leiden University Medical Center, Leiden, The Netherlands
- Netherlands Consortium for Healthy Ageing, Leiden, The Netherlands
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30
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Vascular change and opposing effects of the angiotensin type 2 receptor in a mouse model of vascular cognitive impairment. J Cereb Blood Flow Metab 2015; 35:476-84. [PMID: 25492118 PMCID: PMC4348389 DOI: 10.1038/jcbfm.2014.221] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/05/2014] [Revised: 11/03/2014] [Accepted: 11/10/2014] [Indexed: 01/16/2023]
Abstract
Our aims were to assess the spatiotemporal development of brain pathology in a mouse model of chronic hypoperfusion using magnetic resonance imaging (MRI), and to test whether the renin-angiotensin system (RAS) can offer therapeutic benefit. For the first time, different patterns of cerebral blood flow alterations were observed in hypoperfused mice that ranged from an immediate and dramatic to a delayed decrease in cerebral perfusion. Diffusion tensor imaging revealed increases in several quantitative parameters in different brain regions that are indicative of white-matter degeneration; this began around 3 weeks after induction of hypoperfusion. While this model may be more variable than previously reported, neuroimaging tools represent a promising way to identify surrogate markers of pathology. Vascular remodelling was observed in hypoperfused mice, particularly in the anterior part of the Circle of Willis. While the angiotensin II receptor type 2 agonist, Compound 21 (C21), did not influence this response, it did promote expansion of the basilar artery in microcoil animals. Furthermore, C21-treated animals exhibited increased brain lymphocyte infiltration, and importantly, C21 had opposing effects on spatial reference memory in hypoperfused and sham mice. These results suggest that the RAS may have a role in vascular cognitive impairment.
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31
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Hypertension fails to disrupt white matter integrity in young or aged Fisher (F44) Cyp1a1Ren2 transgenic rats. J Cereb Blood Flow Metab 2015; 35:188-92. [PMID: 25407269 PMCID: PMC4426747 DOI: 10.1038/jcbfm.2014.201] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/17/2014] [Revised: 10/13/2014] [Accepted: 10/20/2014] [Indexed: 11/08/2022]
Abstract
Hypertension is linked with an increased risk of white matter hyperintensities; however, recent findings have questioned this association. We examined whether hypertension and additional cerebrovascular risk factors impacted on white matter integrity in an inducible hypertensive rat. No white matter hyperintensities were observed on magnetic resonance imaging either alone or in conjunction with ageing and high-fat diet. Aged hypertensive rats that were fed a high-fat diet had moderately reduced fractional anisotropy in the corpus callosum with no overt pathological features. Herein we show that moderate hypertension alone or with additional risk factors has minimal impact on white matter integrity in this model.
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Hinman JD, Lee MD, Tung S, Vinters HV, Carmichael ST. Molecular disorganization of axons adjacent to human lacunar infarcts. ACTA ACUST UNITED AC 2015; 138:736-45. [PMID: 25614025 DOI: 10.1093/brain/awu398] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Cerebral microvascular disease predominantly affects brain white matter and deep grey matter, resulting in ischaemic damage that ranges from lacunar infarcts to white matter hyperintensities seen on magnetic resonance imaging. These lesions are common and result in both clinical stroke syndromes and accumulate over time, resulting in cognitive deficits and dementia. Magnetic resonance imaging studies suggest that these lesions progress over time, accumulate adjacent to prior lesions and have a penumbral region susceptible to further injury. The pathological correlates of this adjacent injury in surviving myelinated axons have not been previously defined. In this study, we sought to determine the molecular organization of axons in tissue adjacent to lacunar infarcts and in the regions surrounding microinfarcts, by determining critical elements in axonal function: the morphology and length of node of Ranvier segments and adjacent paranodal segments. We examined post-mortem brain tissue from six patients with lacunar infarcts and tissue from two patients with autosomal dominant retinal vasculopathy and cerebral leukoencephalopathy (previously known as hereditary endotheliopathy with retinopathy, nephropathy and stroke) who accumulate progressive white matter ischaemic lesions in the form of lacunar and microinfarcts. In axons adjacent to lacunar infarcts yet extending up to 150% of the infarct diameter away, both nodal and paranodal length increase by ∼20% and 80%, respectively, reflecting a loss of normal cell-cell adhesion and signalling between axons and oligodendrocytes. Using premorbid magnetic resonance images, brain regions from patients with retinal vasculopathy and cerebral leukoencephalopathy that harboured periventricular white matter hyperintensities were selected and the molecular organization of axons was determined within these regions. As in regions adjacent to lacunar infarcts, nodal and paranodal length in white matter of these patients is increased. Myelin basic protein and neurofilament immunolabelling demonstrates that axons in these adjacent regions have preserved axonal cytoskeleton organization and are generally myelinated. This indicates that the loss of normal axonal microdomain architecture results from disrupted axoglial signalling in white matter adjacent to lacunar and microinfarcts. The loss of the normal molecular organization of nodes and paranodes is associated with axonal degeneration and may lead to impaired conduction velocity across surviving axons after stroke. These findings demonstrate that the degree of white matter injury associated with cerebral microvascular disease extends well beyond what can be identified using imaging techniques and that an improved understanding of the neurobiology in these regions can drive new therapeutic strategies for this disease entity.
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Affiliation(s)
- Jason D Hinman
- 1 Departments of Neurology, David Geffen School of Medicine, University of California Los Angeles, USA
| | - Monica D Lee
- 1 Departments of Neurology, David Geffen School of Medicine, University of California Los Angeles, USA
| | - Spencer Tung
- 2 Department of Pathology and Laboratory Medicine, Section of Neuropathology, David Geffen School of Medicine, University of California Los Angeles, USA
| | - Harry V Vinters
- 1 Departments of Neurology, David Geffen School of Medicine, University of California Los Angeles, USA 2 Department of Pathology and Laboratory Medicine, Section of Neuropathology, David Geffen School of Medicine, University of California Los Angeles, USA
| | - S Thomas Carmichael
- 1 Departments of Neurology, David Geffen School of Medicine, University of California Los Angeles, USA
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33
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White matter tract and glial-associated changes in 5-hydroxymethylcytosine following chronic cerebral hypoperfusion. Brain Res 2014; 1592:82-100. [DOI: 10.1016/j.brainres.2014.09.060] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2014] [Revised: 09/24/2014] [Accepted: 09/25/2014] [Indexed: 12/26/2022]
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34
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McQueen J, Reimer MM, Holland PR, Manso Y, McLaughlin M, Fowler JH, Horsburgh K. Restoration of oligodendrocyte pools in a mouse model of chronic cerebral hypoperfusion. PLoS One 2014; 9:e87227. [PMID: 24498301 PMCID: PMC3911923 DOI: 10.1371/journal.pone.0087227] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2013] [Accepted: 12/25/2013] [Indexed: 12/05/2022] Open
Abstract
Chronic cerebral hypoperfusion, a sustained modest reduction in cerebral blood flow, is associated with damage to myelinated axons and cognitive decline with ageing. Oligodendrocytes (the myelin producing cells) and their precursor cells (OPCs) may be vulnerable to the effects of hypoperfusion and in some forms of injury OPCs have the potential to respond and repair damage by increased proliferation and differentiation. Using a mouse model of cerebral hypoperfusion we have characterised the acute and long term responses of oligodendrocytes and OPCs to hypoperfusion in the corpus callosum. Following 3 days of hypoperfusion, numbers of OPCs and mature oligodendrocytes were significantly decreased compared to controls. However following 1 month of hypoperfusion, the OPC pool was restored and increased numbers of oligodendrocytes were observed. Assessment of proliferation using PCNA showed no significant differences between groups at either time point but showed reduced numbers of proliferating oligodendroglia at 3 days consistent with the loss of OPCs. Cumulative BrdU labelling experiments revealed higher numbers of proliferating cells in hypoperfused animals compared to controls and showed a proportion of these newly generated cells had differentiated into oligodendrocytes in a subset of animals. Expression of GPR17, a receptor important for the regulation of OPC differentiation following injury, was decreased following short term hypoperfusion. Despite changes to oligodendrocyte numbers there were no changes to the myelin sheath as revealed by ultrastructural assessment and fluoromyelin however axon-glial integrity was disrupted after both 3 days and 1 month hypoperfusion. Taken together, our results demonstrate the initial vulnerability of oligodendroglial pools to modest reductions in blood flow and highlight the regenerative capacity of these cells.
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Affiliation(s)
- Jamie McQueen
- Centre for Neuroregeneration, University of Edinburgh, Edinburgh, United Kingdom
- Centre for Cognitive Ageing and Cognitive Epidemiology, University of Edinburgh, Edinburgh, United Kingdom
| | - Michell M. Reimer
- Centre for Neuroregeneration, University of Edinburgh, Edinburgh, United Kingdom
- Centre for Cognitive Ageing and Cognitive Epidemiology, University of Edinburgh, Edinburgh, United Kingdom
| | - Philip R. Holland
- Centre for Neuroregeneration, University of Edinburgh, Edinburgh, United Kingdom
- Centre for Cognitive Ageing and Cognitive Epidemiology, University of Edinburgh, Edinburgh, United Kingdom
| | - Yasmina Manso
- Centre for Neuroregeneration, University of Edinburgh, Edinburgh, United Kingdom
| | - Mark McLaughlin
- School of Veterinary Medicine, Division of Veterinary Biosciences, University of Glasgow, Glasgow, United Kingdom
| | - Jill H. Fowler
- Centre for Neuroregeneration, University of Edinburgh, Edinburgh, United Kingdom
| | - Karen Horsburgh
- Centre for Neuroregeneration, University of Edinburgh, Edinburgh, United Kingdom
- Centre for Cognitive Ageing and Cognitive Epidemiology, University of Edinburgh, Edinburgh, United Kingdom
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35
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Ihara M, Taguchi A, Maki T, Washida K, Tomimoto H. A mouse model of chronic cerebral hypoperfusion characterizing features of vascular cognitive impairment. Methods Mol Biol 2014; 1135:95-102. [PMID: 24510857 DOI: 10.1007/978-1-4939-0320-7_8] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Vascular dementia or vascular cognitive impairment occurs as a result of persistently compromised blood flow to the brain and represents the second most common type of dementia after Alzheimer's disease. In order to investigate its underlying mechanisms, a mouse model of chronic cerebral hypoperfusion has been developed, which involves the narrowing of the bilateral common carotid arteries with newly designed microcoils. This mouse model provides a unique platform to investigate the mechanisms of angiogenesis following chronic cerebral hypoperfusion and to explore potential drugs or cell therapies designed to enhance angiogenesis as a preclinical step toward developing novel treatments for dementia of vascular origin.
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Affiliation(s)
- Masafumi Ihara
- Department of Stroke and Cerebrovascular Diseases, National Cerebral and Cardiovascular Center, Osaka, Japan
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36
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Bink DI, Ritz K, Aronica E, van der Weerd L, Daemen MJAP. Mouse models to study the effect of cardiovascular risk factors on brain structure and cognition. J Cereb Blood Flow Metab 2013; 33:1666-84. [PMID: 23963364 PMCID: PMC3824184 DOI: 10.1038/jcbfm.2013.140] [Citation(s) in RCA: 67] [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: 03/22/2013] [Revised: 06/24/2013] [Accepted: 07/16/2013] [Indexed: 12/13/2022]
Abstract
Recent clinical data indicates that hemodynamic changes caused by cardiovascular diseases such as atherosclerosis, heart failure, and hypertension affect cognition. Yet, the underlying mechanisms of the resulting vascular cognitive impairment (VCI) are poorly understood. One reason for the lack of mechanistic insights in VCI is that research in dementia primarily focused on Alzheimer's disease models. To fill in this gap, we critically reviewed the published data and various models of VCI. Typical findings in VCI include reduced cerebral perfusion, blood-brain barrier alterations, white matter lesions, and cognitive deficits, which have also been reported in different cardiovascular mouse models. However, the tests performed are incomplete and differ between models, hampering a direct comparison between models and studies. Nevertheless, from the currently available data we conclude that a few existing surgical animal models show the key features of vascular cognitive decline, with the bilateral common carotid artery stenosis hypoperfusion mouse model as the most promising model. The transverse aortic constriction and myocardial infarction models may be good alternatives, but these models are as yet less characterized regarding the possible cerebral changes. Mixed models could be used to study the combined effects of different cardiovascular diseases on the deterioration of cognition during aging.
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Affiliation(s)
- Diewertje I Bink
- Department of Pathology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
- Department of Radiology, Leiden University Medical Center, Leiden, The Netherlands
| | - Katja Ritz
- Department of Pathology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Eleonora Aronica
- Department of Pathology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
- SEIN—Stichting Epilepsie Instellingen Nederland, Heemstede, The Netherlands
- Swammerdam Institute for Life Sciences, Center for Neuroscience, University of Amsterdam, Amsterdam, The Netherlands
| | - Louise van der Weerd
- Department of Radiology, Leiden University Medical Center, Leiden, The Netherlands
| | - Mat JAP Daemen
- Department of Pathology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
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37
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Demyelination in mild cognitive impairment suggests progression path to Alzheimer's disease. PLoS One 2013; 8:e72759. [PMID: 24023644 PMCID: PMC3758332 DOI: 10.1371/journal.pone.0072759] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2013] [Accepted: 07/16/2013] [Indexed: 12/03/2022] Open
Abstract
The preclinical Alzheimer's disease (AD) - amnestic mild cognitive impairment (MCI) - is manifested by phenotypes classified into exclusively memory (single-domain) MCI (sMCI) and multiple-domain MCI (mMCI). We suggest that typical MCI-to-AD progression occurs through the sMCI-to-mMCI sequence as a result of the extension of initial pathological processes. To support this hypothesis, we assess myelin content with a Magnetization Transfer Ratio (MTR) in 21 sMCI and 21 mMCI patients and in 42 age-, sex-, and education-matched controls. A conjunction analysis revealed MTR reduction shared by sMCI and mMCI groups in the medial temporal lobe and posterior structures including white matter (WM: splenium, posterior corona radiata) and gray matter (GM: hippocampus; parahippocampal and lingual gyri). A disjunction analysis showed the spread of demyelination to prefrontal WM and insula GM in executive mMCI. Our findings suggest that demyelination starts in the structures affected by neurofibrillary pathology; its presence correlates with the clinical picture and indicates the method of MCI-to-AD progression. In vivo staging of preclinical AD can be developed in terms of WM/GM demyelination.
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38
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Borghesani PR, Madhyastha TM, Aylward EH, Reiter MA, Swarny BR, Schaie KW, Willis SL. The association between higher order abilities, processing speed, and age are variably mediated by white matter integrity during typical aging. Neuropsychologia 2013; 51:1435-44. [PMID: 23507612 DOI: 10.1016/j.neuropsychologia.2013.03.005] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2012] [Revised: 02/09/2013] [Accepted: 03/06/2013] [Indexed: 01/02/2023]
Abstract
Although aging is associated with changes in brain structure and cognition it remains unclear which specific structural changes mediate individual cognitive changes. Several studies have reported that white matter (WM) integrity, as assessed by diffusion tensor imaging (DTI), mediates, in part, age-related differences in processing speed (PS). There is less evidence for WM integrity mediating age-related differences in higher order abilities (e.g., memory and executive functions). In 165 typically aging adults (age range 54-89) we show that WM integrity in select cerebral regions is associated with higher cognitive abilities and accounts variance not accounted for by PS or age. Specifically, voxel-wise analyses using tract-based spatial statistics (TBSS) revealed that WM integrity was associated with reasoning, cognitive flexibility and PS, but not memory or word fluency, after accounting for age and gender. While cerebral fractional anisotropy (FA) was only associated with PS; mean (MD), axial (AD) and radial (RD) diffusivity were associated with reasoning and flexibility. Reasoning was selectively associated with left prefrontal AD, while cognitive flexibility was associated with MD, AD and RD throughout the cerebrum. Average WM metrics within select WM regions of interest accounted for 18% and 29% of the variance in reasoning and flexibility, respectively, similar to the amount of variance accounted for by age. WM metrics mediated ~50% of the age-related variance in reasoning and flexibility and different proportions, 11% for reasoning and 44% for flexibility, of the variance accounted for by PS. In sum, (i) WM integrity is significantly, but variably, related to specific higher cognitive abilities and can account for a similar proportion of variance as age, and (ii) while FA is selectively associated with PS; while MD, AD and RD are associated with reasoning, flexibility and PS. This illustrates both the anatomical and cognitive selectivity of structure-cognition relationships in the aging brain.
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Affiliation(s)
- Paul R Borghesani
- Department of Psychiatry and Behavioral Sciences, University of Washington, Seattle, WA, USA.
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Hainsworth AH, Brittain JF, Khatun H. Pre-clinical models of human cerebral small vessel disease: utility for clinical application. J Neurol Sci 2012; 322:237-40. [PMID: 22698483 DOI: 10.1016/j.jns.2012.05.046] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2012] [Revised: 05/18/2012] [Accepted: 05/23/2012] [Indexed: 12/11/2022]
Abstract
Small vessel disease (SVD) is a frequent cause of vascular cognitive impairment (VCI), encompassing vascular dementia. SVD is characterised by vasculopathy in deep penetrating arteries, diffuse white matter lesions (seen radiologically as leukoaraiosis) and focal, lacunar infarcts. Risk factors are age and hypertension but the pathogenic mechanism is unknown. Recent systematic reviews assessed experimental models of SVD or VCI. Chronically hypertensive animals (e.g. stroke-prone spontaneously hypertensive rats) display some features of SVD vasculopathy, such as vessel wall thickening. White matter lesions are seen in chronic hypoperfusion states (e.g. carotid occlusion/stenosis models). Small focal infarcts are induced by targeted ischemic challenge (surgical occlusion of a small artery, or stereotaxic endothelin-1 injection). Some degree of cognitive impairment is detectable in most cerebrovascular models, probably reflecting the broad neuroanatomical mapping of cognitive function. Important confounds to be considered in animal models of VCI are somatosensory impairment and hippocampal damage. Advances in clinical understanding will come from targeting specific questions on some aspect of SVD (e.g. vasculopathy, white matter damage) to the appropriate model in vivo. In vivo models of SVD are likely to benefit experimental studies of pathological processes, interactions with other brain disease states (such as Alzheimer disease), and therapeutic strategies.
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Affiliation(s)
- Atticus H Hainsworth
- Stroke & Dementia Research Centre, St George's University of London, London, United Kingdom.
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40
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Abstract
Myelinated axons have a distinct protein architecture essential for action potential propagation, neuronal communication, and maintaining cognitive function. Damage to myelinated axons, associated with cerebral hypoperfusion, contributes to age-related cognitive decline. We sought to determine early alterations in the protein architecture of myelinated axons and potential mechanisms after hypoperfusion. Using a mouse model of hypoperfusion, we assessed changes in proteins critical to the maintenance of paranodes, nodes of Ranvier, axon-glial integrity, axons, and myelin by confocal laser scanning microscopy. As early as 3 d after hypoperfusion, the paranodal septate-like junctions were damaged. This was marked by a progressive reduction of paranodal Neurofascin signal and a loss of septate-like junctions. Concurrent with paranodal disruption, there was a significant increase in nodal length, identified by Nav1.6 staining, with hypoperfusion. Disruption of axon-glial integrity was also determined after hypoperfusion by changes in the spatial distribution of myelin-associated glycoprotein staining. These nodal/paranodal changes were more pronounced after 1 month of hypoperfusion. In contrast, the nodal anchoring proteins AnkyrinG and Neurofascin 186 were unchanged and there were no overt changes in axonal and myelin integrity with hypoperfusion. A microarray analysis of white matter samples indicated that there were significant alterations in 129 genes. Subsequent analysis indicated alterations in biological pathways, including inflammatory responses, cytokine-cytokine receptor interactions, blood vessel development, and cell proliferation processes. Our results demonstrate that hypoperfusion leads to a rapid disruption of key proteins critical to the stability of the axon-glial connection that is mediated by a diversity of molecular events.
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41
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Ihara M, Tomimoto H. Lessons from a mouse model characterizing features of vascular cognitive impairment with white matter changes. J Aging Res 2011; 2011:978761. [PMID: 22132331 PMCID: PMC3216359 DOI: 10.4061/2011/978761] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2011] [Accepted: 07/26/2011] [Indexed: 01/13/2023] Open
Abstract
With the demographic shift in age in advanced countries inexorably set to progress in the 21st century, dementia will become one of the most important health problems worldwide. Vascular cognitive impairment is the second most common type of dementia after Alzheimer's disease and is frequently responsible for the cognitive decline of the elderly. It is characterized by cerebrovascular white matter changes; thus, in order to investigate the underlying mechanisms involved in white matter changes, a mouse model of chronic cerebral hypoperfusion has been developed, which involves the narrowing of the bilateral common carotid arteries with newly designed microcoils. The purpose of this paper is to provide a comprehensive summary of the achievements made with the model that shows good reproducibility of the white matter changes characterized by blood-brain barrier disruption, glial activation, oxidative stress, and oligodendrocyte loss following chronic cerebral hypoperfusion. Detailed characterization of this model may help to decipher the substrates associated with impaired memory and move toward a more integrated therapy of vascular cognitive impairment.
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Affiliation(s)
- Masafumi Ihara
- Department of Neurology, Kyoto University Graduate School of Medicine, 54 Kawahara-cho, Shogoin, Sakyo, Kyoto 606-8507, Japan
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42
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Heterogeneity in age-related white matter changes. Acta Neuropathol 2011; 122:171-85. [PMID: 21706175 DOI: 10.1007/s00401-011-0851-x] [Citation(s) in RCA: 225] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2011] [Revised: 06/15/2011] [Accepted: 06/16/2011] [Indexed: 10/18/2022]
Abstract
White matter changes occur endemically in routine magnetic resonance imaging (MRI) scans of elderly persons. MRI appearance and histopathological correlates of white matter changes are heterogeneous. Smooth periventricular hyperintensities, including caps around the ventricular horns, periventricular lining and halos are likely to be of non-vascular origin. They relate to a disruption of the ependymal lining with subependymal widening of the extracellular space and have to be differentiated from subcortical and deep white matter abnormalities. For the latter a distinction needs to be made between punctate, early confluent and confluent types. Although punctate white matter lesions often represent widened perivascular spaces without substantial ischemic tissue damage, early confluent and confluent lesions correspond to incomplete ischemic destruction. Punctate abnormalities on MRI show a low tendency for progression, while early confluent and confluent changes progress rapidly. The causative and modifying pathways involved in the occurrence of sporadic age-related white matter changes are still incompletely understood, but recent microarray and genome-wide association approaches increased the notion of pathways that might be considered as targets for therapeutic intervention. The majority of differentially regulated transcripts in white matter lesions encode genes associated with immune function, cell cycle, proteolysis, and ion transport. Genome-wide association studies identified six SNPs mapping to a locus on chromosome 17q25 to be related to white matter lesion load in the general population. We also report first and preliminary data that demonstrate apolipoprotein E (ApoE) immunoreactivity in white matter lesions and support epidemiological findings indicating that ApoE is another factor possibly related to white matter lesion occurrence. Further insights come from modern MRI techniques, such as diffusion tensor and magnetization transfer imaging, as they provide tools for the characterization of normal-appearing brain tissue beyond what can be expected from standard MRI scans. There is a need for additional pre- and postmortem studies in humans, including these new imaging techniques.
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