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Bagheri M, Habibzadeh S, Moeini M. Transient Changes in Cerebral Tissue Oxygen, Glucose, and Temperature by Microstrokes: A Computational Study. Microcirculation 2024; 31:e12872. [PMID: 38944839 DOI: 10.1111/micc.12872] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2024] [Revised: 05/09/2024] [Accepted: 06/08/2024] [Indexed: 07/02/2024]
Abstract
OBJECTIVE This study focuses on evaluating the disruptions in key physiological parameters during microstroke events to assess their severity. METHODS A mathematical model was developed to simulate the changes in cerebral tissue pO2, glucose concentration, and temperature due to blood flow interruptions. The model considers variations in baseline cerebral blood flow (CBF), capillary density, and blood oxygen/glucose levels, as well as ambient temperature changes. RESULTS Simulations indicate that complete blood flow obstruction still allows for limited glucose availability, supporting nonoxidative metabolism and potentially exacerbating lactate buildup and acidosis. Partial obstructions decrease tissue pO2, with minimal impact on glucose level, which can remain almost unchanged or even slightly increase. Reduced CBF, capillary density, or blood oxygen due to aging or disease enhances hypoxia risk at lower obstruction levels, with capillary density having a significant effect on stroke severity by influencing both pO2 and glucose levels. Conditions could lead to co-occurrence of hypoxia/hypoglycemia or hypoxia/hyperglycemia, each worsening outcomes. Temperature effects were minimal in deep brain regions but varied near the skull by 0.2-0.8°C depending on ambient temperature. CONCLUSIONS The model provides insights into the conditions driving severe stroke outcomes based on estimated levels of hypoxia, hypoglycemia, hyperglycemia, and temperature changes.
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Affiliation(s)
- Marzieh Bagheri
- Department of Chemical Engineering, Amirkabir University of Technology (Tehran Polytechnic), Tehran, Iran
| | - Sajjad Habibzadeh
- Department of Chemical Engineering, Amirkabir University of Technology (Tehran Polytechnic), Tehran, Iran
| | - Mohammad Moeini
- Department of Biomedical Engineering, Amirkabir University of Technology (Tehran Polytechnic), Tehran, Iran
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2
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Glück C, Zhou Q, Droux J, Chen Z, Glandorf L, Wegener S, Razansky D, Weber B, El Amki M. Pia-FLOW: Deciphering hemodynamic maps of the pial vascular connectome and its response to arterial occlusion. Proc Natl Acad Sci U S A 2024; 121:e2402624121. [PMID: 38954543 PMCID: PMC11252916 DOI: 10.1073/pnas.2402624121] [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: 02/07/2024] [Accepted: 06/04/2024] [Indexed: 07/04/2024] Open
Abstract
The pial vasculature is the sole source of blood supply to the neocortex. The brain is contained within the skull, a vascularized bone marrow with a unique anatomical connection to the brain meninges. Recent developments in tissue clearing have enabled detailed mapping of the entire pial and calvarial vasculature. However, what are the absolute flow rate values of those vascular networks? This information cannot accurately be retrieved with the commonly used bioimaging methods. Here, we introduce Pia-FLOW, a unique approach based on large-scale transcranial fluorescence localization microscopy, to attain hemodynamic imaging of the whole murine pial and calvarial vasculature at frame rates up to 1,000 Hz and spatial resolution reaching 5.4 µm. Using Pia-FLOW, we provide detailed maps of flow velocity, direction, and vascular diameters which can serve as ground-truth data for further studies, advancing our understanding of brain fluid dynamics. Furthermore, Pia-FLOW revealed that the pial vascular network functions as one unit for robust allocation of blood after stroke.
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Affiliation(s)
- Chaim Glück
- Institute of Pharmacology and Toxicology, University of Zurich, Zurich8057, Switzerland
- Neuroscience Center Zurich, University of Zurich and ETH Zurich, Zurich8057, Switzerland
| | - Quanyu Zhou
- Institute of Pharmacology and Toxicology, University of Zurich, Zurich8057, Switzerland
- Institute for Biomedical Engineering, Department of Information Technology and Electrical Engineering, ETH Zurich, Zurich8092, Switzerland
| | - Jeanne Droux
- Neuroscience Center Zurich, University of Zurich and ETH Zurich, Zurich8057, Switzerland
- Department of Neurology, University Hospital and University of Zurich, Zurich8091, Switzerland
| | - Zhenyue Chen
- Institute of Pharmacology and Toxicology, University of Zurich, Zurich8057, Switzerland
- Institute for Biomedical Engineering, Department of Information Technology and Electrical Engineering, ETH Zurich, Zurich8092, Switzerland
| | - Lukas Glandorf
- Institute of Pharmacology and Toxicology, University of Zurich, Zurich8057, Switzerland
- Institute for Biomedical Engineering, Department of Information Technology and Electrical Engineering, ETH Zurich, Zurich8092, Switzerland
| | - Susanne Wegener
- Neuroscience Center Zurich, University of Zurich and ETH Zurich, Zurich8057, Switzerland
- Department of Neurology, University Hospital and University of Zurich, Zurich8091, Switzerland
| | - Daniel Razansky
- Institute of Pharmacology and Toxicology, University of Zurich, Zurich8057, Switzerland
- Neuroscience Center Zurich, University of Zurich and ETH Zurich, Zurich8057, Switzerland
- Institute for Biomedical Engineering, Department of Information Technology and Electrical Engineering, ETH Zurich, Zurich8092, Switzerland
| | - Bruno Weber
- Institute of Pharmacology and Toxicology, University of Zurich, Zurich8057, Switzerland
- Neuroscience Center Zurich, University of Zurich and ETH Zurich, Zurich8057, Switzerland
| | - Mohamad El Amki
- Neuroscience Center Zurich, University of Zurich and ETH Zurich, Zurich8057, Switzerland
- Department of Neurology, University Hospital and University of Zurich, Zurich8091, Switzerland
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3
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Huang J, Biessels GJ, de Leeuw FE, Ii Y, Skoog I, Mok V, Chen C, Hilal S. Cerebral microinfarcts revisited: Detection, causes, and clinical relevance. Int J Stroke 2024; 19:7-15. [PMID: 37470314 DOI: 10.1177/17474930231187979] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/21/2023]
Abstract
Cerebral microinfarcts (CMIs) are small ischemic lesions invisible to the naked eye at brain autopsy, while the larger ones (0.5-4 mm in diameter) have been visualized in-vivo on magnetic resonance imaging (MRI). CMIs can be detected on diffusion-weighted imaging (DWI) as incidental small DWI-positive lesions (ISDPLs) and on structural MRI for those confined to the cortex and in the chronic phase. ISDPLs may evolve into old cortical-CMIs, white matter hyperintensities or disappear depending on their location and size. Novel techniques in neuropathology and neuroimaging facilitate the detection of CMIs, which promotes understanding of these lesions. CMIs have heterogeneous causes, involving both cerebral small- and large-vessel disease as well as heart diseases such as atrial fibrillation and congestive heart failure. The underlying mechanisms incorporate vascular remodeling, inflammation, blood-brain barrier leakage, penetrating venule congestion, cerebral hypoperfusion, and microembolism. CMIs lead to clinical outcomes, including cognitive decline, a higher risk of stroke and mortality, and accelerated neurobehavioral disturbances. It has been suggested that CMIs can impair brain function and connectivity beyond the microinfarct core and are also associated with perilesional and global cortical atrophy. This review aims to summarize recent progress in studies involving both cortical-CMIs and ISDPLs since 2017, including their detection, etiology, risk factors, MRI correlates, and clinical consequences.
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Affiliation(s)
- Jiannan Huang
- Saw Swee Hock School of Public Health, National University of Singapore and National University Health System, Singapore
| | - Geert Jan Biessels
- Department of Neurology, UMC Utrecht Brain Center, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Frank-Erik de Leeuw
- Department of Neurology, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Yuichiro Ii
- Department of Neurology, Mie University Graduate School of Medicine, Tsu, Japan
- Department of Neuroimaging and Pathophysiology, Mie University School of Medicine, Tsu, Japan
| | - Ingmar Skoog
- Institute of Neuroscience and Physiology and Centre for Ageing and Health, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
- Department of Psychiatry Cognition and Old Age Psychiatry, Sahlgrenska University Hospital, Region Västra Götaland, Mölndal, Sweden
| | - Vincent Mok
- Division of Neurology, Department of Medicine and Therapeutics, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, Hong Kong
- Lau Tat-chuen Research Centre of Brain Degenerative Diseases in Chinese and Li Ka Shing Institute of Health Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, Hong Kong
| | - Christopher Chen
- Memory Aging and Cognition Centre, National University Health System, Singapore
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Saima Hilal
- Saw Swee Hock School of Public Health, National University of Singapore and National University Health System, Singapore
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
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4
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Polk FD, Hakim MA, Silva JF, Behringer EJ, Pires PW. Endothelial K IR2 channel dysfunction in aged cerebral parenchymal arterioles. Am J Physiol Heart Circ Physiol 2023; 325:H1360-H1372. [PMID: 37801044 PMCID: PMC10907073 DOI: 10.1152/ajpheart.00279.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/12/2023] [Revised: 09/27/2023] [Accepted: 09/28/2023] [Indexed: 10/07/2023]
Abstract
Aging is associated with cognitive decline via incompletely understood mechanisms. Cerebral microvascular dysfunction occurs in aging, particularly impaired endothelium-mediated dilation. Parenchymal arterioles are bottlenecks of the cerebral microcirculation, and dysfunction causes a mismatch in nutrient demand and delivery, leaving neurons at risk. Extracellular nucleotides elicit parenchymal arteriole dilation by activating endothelial purinergic receptors (P2Y), leading to opening of K+ channels, including inwardly-rectifying K+ channels (KIR2). These channels amplify hyperpolarizing signals, resulting in dilation. However, it remains unknown if endothelial P2Y and KIR2 signaling are altered in brain parenchymal arterioles during aging. We hypothesized that aging impairs endothelial P2Y and KIR2 function in parenchymal arterioles. We observed reduced dilation to the purinergic agonist 2-methyl-S-ADP (1 µM) in arterioles from Aged (>24-month-old) mice when compared to Young (4-6 months of age) despite similar hyperpolarization in endothelial cells tubes. No differences were observed in vasodilation or endothelial cell hyperpolarization to activation of small- and intermediate-conductance Ca2+-activated K+ channels (KCa2.3 / KCa3.1) by NS309. Hyperpolarization to 15 mM [K+]E was smaller in Aged than Young mice, despite a paradoxical increased dilation in Aged arterioles to 15 mM [K+]E that was unchanged by endothelium removal. KIR2 Inhibition attenuated vasodilatory responses to 15 mM [K+]E and 1 µM 2-me-S-ADP in both Young and Aged arterioles. Further, we observed a significant increase in myogenic tone in Aged parenchymal arterioles, which was not enhanced by endothelium removal. We conclude that aging impairs endothelial KIR2 channel function in the cerebral microcirculation with possible compensation by smooth muscle cells.
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Affiliation(s)
- Felipe D Polk
- Department of Physiology, University of Arizona, Tucson, Arizona, United States
| | - Md A Hakim
- Loma Linda University, Loma Linda, CA, United States
| | - Josiane F Silva
- Physiology, University of Arizona, Tucson, Arizona, United States
| | - Erik J Behringer
- Basic Sciences, Loma Linda University, Loma Linda, CA, United States
| | - Paulo W Pires
- Physiology, University of Arizona, Tucson, AZ, United States
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5
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Zedde M, Grisendi I, Assenza F, Vandelli G, Napoli M, Moratti C, Lochner P, Seiffge DJ, Piazza F, Valzania F, Pascarella R. The Venular Side of Cerebral Amyloid Angiopathy: Proof of Concept of a Neglected Issue. Biomedicines 2023; 11:2663. [PMID: 37893037 PMCID: PMC10604278 DOI: 10.3390/biomedicines11102663] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2023] [Revised: 09/23/2023] [Accepted: 09/25/2023] [Indexed: 10/29/2023] Open
Abstract
Small vessel diseases (SVD) is an umbrella term including several entities affecting small arteries, arterioles, capillaries, and venules in the brain. One of the most relevant and prevalent SVDs is cerebral amyloid angiopathy (CAA), whose pathological hallmark is the deposition of amyloid fragments in the walls of small cortical and leptomeningeal vessels. CAA frequently coexists with Alzheimer's Disease (AD), and both are associated with cerebrovascular events, cognitive impairment, and dementia. CAA and AD share pathophysiological, histopathological and neuroimaging issues. The venular involvement in both diseases has been neglected, although both animal models and human histopathological studies found a deposition of amyloid beta in cortical venules. This review aimed to summarize the available information about venular involvement in CAA, starting from the biological level with the putative pathomechanisms of cerebral damage, passing through the definition of the peculiar angioarchitecture of the human cortex with the functional organization and consequences of cortical arteriolar and venular occlusion, and ending to the hypothesized links between cortical venular involvement and the main neuroimaging markers of the disease.
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Affiliation(s)
- Marialuisa Zedde
- Neurology Unit, Stroke Unit, AUSL-IRCCS di Reggio Emilia, Via Amendola 2, 42122 Reggio Emilia, Italy
| | - Ilaria Grisendi
- Neurology Unit, Stroke Unit, AUSL-IRCCS di Reggio Emilia, Via Amendola 2, 42122 Reggio Emilia, Italy
| | - Federica Assenza
- Neurology Unit, Stroke Unit, AUSL-IRCCS di Reggio Emilia, Via Amendola 2, 42122 Reggio Emilia, Italy
| | - Gabriele Vandelli
- Neurology Unit, Stroke Unit, AUSL-IRCCS di Reggio Emilia, Via Amendola 2, 42122 Reggio Emilia, Italy
| | - Manuela Napoli
- Neuroradiology Unit, AUSL-IRCCS di Reggio Emilia, Via Amendola 2, 42122 Reggio Emilia, Italy
| | - Claudio Moratti
- Neuroradiology Unit, AUSL-IRCCS di Reggio Emilia, Via Amendola 2, 42122 Reggio Emilia, Italy
| | - Piergiorgio Lochner
- Department of Neurology, Saarland University Medical Center, 66421 Homburg, Germany;
| | - David J. Seiffge
- Department of Neurology, Inselspital, Bern University Hospital, University of Bern, 3010 Bern, Switzerland
| | - Fabrizio Piazza
- CAA and AD Translational Research and Biomarkers Laboratory, School of Medicine and Surgery, University of Milano-Bicocca, Via Cadore 48, 20900 Monza, Italy;
| | - Franco Valzania
- Neurology Unit, Stroke Unit, AUSL-IRCCS di Reggio Emilia, Via Amendola 2, 42122 Reggio Emilia, Italy
| | - Rosario Pascarella
- Neuroradiology Unit, AUSL-IRCCS di Reggio Emilia, Via Amendola 2, 42122 Reggio Emilia, Italy
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6
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Zhu L, Wang M, Liu Y, Fu P, Zhang W, Zhang H, Roe AW, Xi W. Single-microvessel occlusion produces lamina-specific microvascular flow vasodynamics and signs of neurodegenerative change. Cell Rep 2023; 42:112469. [PMID: 37141094 DOI: 10.1016/j.celrep.2023.112469] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2022] [Revised: 01/12/2023] [Accepted: 04/18/2023] [Indexed: 05/05/2023] Open
Abstract
Recent studies have highlighted the importance of understanding the architecture and function of microvasculature, and dysfunction of these microvessels may underlie neurodegenerative disease. Here, we utilize a high-precision ultrafast laser-induced photothrombosis (PLP) method to occlude single capillaries and then quantitatively study the effects on vasodynamics and surrounding neurons. Analysis of the microvascular architecture and hemodynamics after single-capillary occlusion reveals distinct changes upstream vs. downstream branches, which shows rapid regional flow redistribution and local downstream blood-brain barrier (BBB) leakage. Focal ischemia via capillary occlusions surrounding labeled target neurons induces dramatic and rapid lamina-specific changes in neuronal dendritic architecture. Further, we find that micro-occlusion at two different depths within the same vascular arbor results in distinct effects on flow profiles in layers 2/3 vs layer 4. The current results reveal laminar-scale regulation distinctions in microinfarct response and raise the possibility that relatively greater impacts on microvascular function contribute to cognitive decline in neurodegenerative disease.
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Affiliation(s)
- Liang Zhu
- Interdisciplinary Institute of Neuroscience and Technology (ZIINT), The Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou 310020, China; Interdisciplinary Institute of Neuroscience and Technology (ZIINT), College of Biomedical Engineering and Instrument Science, Zhejiang University, Hangzhou 310027, China
| | - Mengqi Wang
- Interdisciplinary Institute of Neuroscience and Technology (ZIINT), The Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou 310020, China
| | - Yin Liu
- Interdisciplinary Institute of Neuroscience and Technology (ZIINT), The Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou 310020, China
| | - Peng Fu
- Interdisciplinary Institute of Neuroscience and Technology (ZIINT), The Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou 310020, China
| | - Weijie Zhang
- Interdisciplinary Institute of Neuroscience and Technology (ZIINT), College of Biomedical Engineering and Instrument Science, Zhejiang University, Hangzhou 310027, China
| | - Hequn Zhang
- Interdisciplinary Institute of Neuroscience and Technology (ZIINT), The Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou 310020, China
| | - Anna Wang Roe
- Interdisciplinary Institute of Neuroscience and Technology (ZIINT), The Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou 310020, China; MOE Frontier Science Center for Brain Research and Brain Machine Integration, Zhejiang University, Hangzhou 310058, China; Key Laboratory of Biomedical Engineering of the Ministry of Education, College of Biomedical Engineering and Instrument Science, Zhejiang University, Hangzhou 310027, China.
| | - Wang Xi
- Interdisciplinary Institute of Neuroscience and Technology (ZIINT), The Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou 310020, China; MOE Frontier Science Center for Brain Research and Brain Machine Integration, Zhejiang University, Hangzhou 310058, China; Key Laboratory of Biomedical Engineering of the Ministry of Education, College of Biomedical Engineering and Instrument Science, Zhejiang University, Hangzhou 310027, China.
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7
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Abstract
Despite enormous advances, cardiovascular disorders are still a major threat to global health and are responsible for one-third of deaths worldwide. Research for new therapeutics and the investigation of their effects on vascular parameters is often limited by species-specific pathways and a lack of high-throughput methods. The complex 3-dimensional environment of blood vessels, intricate cellular crosstalks, and organ-specific architectures further complicate the quest for a faithful human in vitro model. The development of novel organoid models of various tissues such as brain, gut, and kidney signified a leap for the field of personalized medicine and disease research. By utilizing either embryonic- or patient-derived stem cells, different developmental and pathological mechanisms can be modeled and investigated in a controlled in vitro environment. We have recently developed self-organizing human capillary blood vessel organoids that recapitulate key processes of vasculogenesis, angiogenesis, and diabetic vasculopathy. Since then, this organoid system has been utilized as a model for other disease processes, refined, and adapted for organ specificity. In this review, we will discuss novel and alternative approaches to blood vessel engineering and explore the cellular identity of engineered blood vessels in comparison to in vivo vasculature. Future perspectives and the therapeutic potential of blood vessel organoids will be discussed.
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Affiliation(s)
- Kirill Salewskij
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences, Vienna (K.S., J.M.P.).,Vienna BioCenter PhD Program, Doctoral School of the University of Vienna and Medical University of Vienna, Austria (K.S.)
| | - Josef M Penninger
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences, Vienna (K.S., J.M.P.).,Department of Medical Genetics, Life Sciences Institute, University of British Columbia, Vancouver, Canada (J.M.P.)
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8
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Kim MK, Choi W, Moon HJ, Han S, Shin HJ. Targeted photothrombotic subcortical small vessel occlusion using in vivo real-time fiber bundle endomicroscopy in mice. BIOMEDICAL OPTICS EXPRESS 2023; 14:687-702. [PMID: 36874485 PMCID: PMC9979683 DOI: 10.1364/boe.473407] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/19/2022] [Revised: 11/18/2022] [Accepted: 12/23/2022] [Indexed: 06/18/2023]
Abstract
The development of an accurate subcortical small vessel occlusion model for pathophysiological studies of subcortical ischemic stroke is still insignificant. In this study, in vivo real-time fiber bundle endomicroscopy (FBEµ) was applied to develop subcortical photothrombotic small vessel occlusion model in mice with minimal invasiveness. Our FBFµ system made it possible to precisely target specific blood vessels in deep brain and simultaneously observe the clot formation and blood flow blockage inside the target blood vessel during photochemical reactions. A fiber bundle probe was directly inserted into the anterior pretectal nucleus of the thalamus in brain of live mice to induce a targeted occlusion in small vessels. Then, targeted photothrombosis was performed using a patterned laser, observing the process through the dual-color fluorescence imaging. On day one post occlusion, infarct lesions are measured using TTC staining and post hoc histology. The results show that FBEµ applied to targeted photothrombosis can successfully generate a subcortical small vessel occlusion model for lacunar stroke.
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Affiliation(s)
- Min-kyung Kim
- Bionics Research Center, Biomedical Research Division, Korea Institute of Science and Technology (KIST), Seoul, 02792, Republic of Korea
| | - Wonseok Choi
- Bionics Research Center, Biomedical Research Division, Korea Institute of Science and Technology (KIST), Seoul, 02792, Republic of Korea
- Department of Biomedical Engineering, Yonsei University, 1 Yonseidae-gil, Wonju, Gangwon-do, 26493, Republic of Korea
| | - Hyuk-June Moon
- Bionics Research Center, Biomedical Research Division, Korea Institute of Science and Technology (KIST), Seoul, 02792, Republic of Korea
| | - Sungmin Han
- Bionics Research Center, Biomedical Research Division, Korea Institute of Science and Technology (KIST), Seoul, 02792, Republic of Korea
| | - Hyun-joon Shin
- Bionics Research Center, Biomedical Research Division, Korea Institute of Science and Technology (KIST), Seoul, 02792, Republic of Korea
- Division of Bio-Medical Science & Technology, KIST School, Korea University of Science and Technology (UST), Seoul, 02792, Republic of Korea
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9
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Abi Rached NM, Gbotosho OT, Archer DR, Jones JA, Sterling MS, Hyacinth HI. Adhesion molecules and cerebral microvascular hemodynamic abnormalities in sickle cell disease. Front Neurol 2022; 13:976063. [PMID: 36570439 PMCID: PMC9767957 DOI: 10.3389/fneur.2022.976063] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2022] [Accepted: 11/21/2022] [Indexed: 12/12/2022] Open
Abstract
Cerebrovascular abnormalities are a common feature of sickle cell disease that may be associated with risk of vaso-occlusive pain crises, microinfarcts, and cognitive impairment. An activated endothelium and adhesion factors, VCAM-1 and P-selectin, are implicated in sickle cell vasculopathy, including abnormal hemodynamics and leukocyte adherence. This study examined the association between cerebral expression of these adhesion factors and cortical microvascular blood flow dynamics by using in-vivo two-photon microscopy. We also examined the impact of blood transfusion treatment on these markers of vasculopathy. Results showed that sickle cell mice had significantly higher maximum red blood cell (RBC) velocity (6.80 ± 0.25 mm/sec, p ≤ 0.01 vs. 5.35 ± 0.35 mm/sec) and more frequent blood flow reversals (18.04 ± 0.95 /min, p ≤ 0.01 vs. 13.59 ± 1.40 /min) in the cortical microvasculature compared to controls. In addition, sickle cell mice had a 2.6-fold (RFU/mm2) increase in expression of VCAM-1 and 17-fold (RFU/mm2) increase in expression of P-selectin compared to controls. This was accompanied by an increased frequency in leukocyte adherence (4.83 ± 0.57 /100 μm/min vs. 2.26 ± 0.37 /100 μm/min, p ≤ 0.001). We also found that microinfarcts identified in sickle cell mice were 50% larger than in controls. After blood transfusion, many of these parameters improved, as results demonstrated that sickle cell mice had a lower post-transfusion maximum RBC velocity (8.30 ± 0.98 mm/sec vs. 11.29 ± 0.95 mm/sec), lower frequency of blood flow reversals (12.80 ± 2.76 /min vs. 27.75 ± 2.09 /min), and fewer instances of leukocyte adherence compared to their pre-transfusion imaging time point (1.35 ± 0.32 /100 μm/min vs. 3.46 ± 0.58 /100 μm/min). Additionally, we found that blood transfusion was associated with lower expression of adhesion factors. Our results suggest that blood transfusion and adhesion factors, VCAM-1 and P-selectin, are potential therapeutic targets for addressing cerebrovascular pathology, such as vaso-occlusion, in sickle cell disease.
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Affiliation(s)
- Noor Mary Abi Rached
- Neuroscience and Behavioral Biology Undergraduate Program, Emory University, Atlanta, GA, United States
| | - Oluwabukola T. Gbotosho
- Department of Neurology and Rehabilitation Medicine, University of Cincinnati College of Medicine, Cincinnati, OH, United States
| | - David R. Archer
- Aflac Cancer and Blood Disorders Center, Emory University Department of Pediatrics and Children's Healthcare of Atlanta, Atlanta, GA, United States
| | - Jayre A. Jones
- Aflac Cancer and Blood Disorders Center, Emory University Department of Pediatrics and Children's Healthcare of Atlanta, Atlanta, GA, United States
| | - Morgan S. Sterling
- Aflac Cancer and Blood Disorders Center, Emory University Department of Pediatrics and Children's Healthcare of Atlanta, Atlanta, GA, United States
| | - Hyacinth I. Hyacinth
- Department of Neurology and Rehabilitation Medicine, University of Cincinnati College of Medicine, Cincinnati, OH, United States
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10
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Wang Y, LeDue JM, Murphy TH. Multiscale imaging informs translational mouse modeling of neurological disease. Neuron 2022; 110:3688-3710. [PMID: 36198319 DOI: 10.1016/j.neuron.2022.09.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2022] [Revised: 05/26/2022] [Accepted: 09/06/2022] [Indexed: 11/05/2022]
Abstract
Multiscale neurophysiology reveals that simple motor actions are associated with changes in neuronal firing in virtually every brain region studied. Accordingly, the assessment of focal pathology such as stroke or progressive neurodegenerative diseases must also extend widely across brain areas. To derive mechanistic information through imaging, multiple resolution scales and multimodal factors must be included, such as the structure and function of specific neurons and glial cells and the dynamics of specific neurotransmitters. Emerging multiscale methods in preclinical animal studies that span micro- to macroscale examinations fill this gap, allowing a circuit-based understanding of pathophysiological mechanisms. Combined with high-performance computation and open-source data repositories, these emerging multiscale and large field-of-view techniques include live functional ultrasound, multi- and single-photon wide-scale light microscopy, video-based miniscopes, and tissue-penetrating fiber photometry, as well as variants of post-mortem expansion microscopy. We present these technologies and outline use cases and data pipelines to uncover new knowledge within animal models of stroke, Alzheimer's disease, and movement disorders.
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Affiliation(s)
- Yundi Wang
- University of British Columbia, Department of Psychiatry, Kinsmen Laboratory of Neurological Research, Detwiller Pavilion, 2255 Wesbrook Mall, Vancouver, BC V6T 1Z3, Canada; Djavad Mowafaghian Centre for Brain Health, University of British Columbia, 2215 Wesbrook Mall, Vancouver, BC V6T 1Z3, Canada
| | - Jeffrey M LeDue
- University of British Columbia, Department of Psychiatry, Kinsmen Laboratory of Neurological Research, Detwiller Pavilion, 2255 Wesbrook Mall, Vancouver, BC V6T 1Z3, Canada; Djavad Mowafaghian Centre for Brain Health, University of British Columbia, 2215 Wesbrook Mall, Vancouver, BC V6T 1Z3, Canada
| | - Timothy H Murphy
- University of British Columbia, Department of Psychiatry, Kinsmen Laboratory of Neurological Research, Detwiller Pavilion, 2255 Wesbrook Mall, Vancouver, BC V6T 1Z3, Canada; Djavad Mowafaghian Centre for Brain Health, University of British Columbia, 2215 Wesbrook Mall, Vancouver, BC V6T 1Z3, Canada.
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11
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Calabrese B, Jones SL, Shiraishi-Yamaguchi Y, Lingelbach M, Manor U, Svitkina TM, Higgs HN, Shih AY, Halpain S. INF2-mediated actin filament reorganization confers intrinsic resilience to neuronal ischemic injury. Nat Commun 2022; 13:6037. [PMID: 36229429 PMCID: PMC9558009 DOI: 10.1038/s41467-022-33268-y] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2021] [Accepted: 09/09/2022] [Indexed: 12/24/2022] Open
Abstract
During early ischemic brain injury, glutamate receptor hyperactivation mediates neuronal death via osmotic cell swelling. Here we show that ischemia and excess NMDA receptor activation cause actin to rapidly and extensively reorganize within the somatodendritic compartment. Normally, F-actin is concentrated within dendritic spines. However, <5 min after bath-applied NMDA, F-actin depolymerizes within spines and polymerizes into stable filaments within the dendrite shaft and soma. A similar actinification occurs after experimental ischemia in culture, and photothrombotic stroke in mouse. Following transient NMDA incubation, actinification spontaneously reverses. Na+, Cl-, water, and Ca2+ influx, and spine F-actin depolymerization are all necessary, but not individually sufficient, for actinification, but combined they induce activation of the F-actin polymerization factor inverted formin-2 (INF2). Silencing of INF2 renders neurons vulnerable to cell death and INF2 overexpression is protective. Ischemia-induced dendritic actin reorganization is therefore an intrinsic pro-survival response that protects neurons from death induced by cell edema.
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Affiliation(s)
- Barbara Calabrese
- Department of Neurobiology, School of Biological Sciences, University of California, San Diego, and Sanford Consortium for Regenerative Medicine, La Jolla, CA, 92093, USA
| | - Steven L Jones
- Department of Biology, University of Pennsylvania, Philadelphia, PA, 19104-4544, USA
| | | | - Michael Lingelbach
- Neurosciences Interdepartmental Program, Stanford University, Stanford, CA, 94305, USA
| | - Uri Manor
- The Salk Institute for Biological Studies, La Jolla, CA, 92037, USA
| | - Tatyana M Svitkina
- Department of Biology, University of Pennsylvania, Philadelphia, PA, 19104-4544, USA
| | - Henry N Higgs
- Department of Biochemistry, Geisel School of Medicine, Hanover, NH, 03755, USA
| | - Andy Y Shih
- Center for Developmental Biology and Regenerative Medicine, Seattle Children's Research Institute, Seattle, WA, 98101, USA
- Department of Neuroscience, Medical University of South Carolina, Charleston, SC, USA
| | - Shelley Halpain
- Department of Neurobiology, School of Biological Sciences, University of California, San Diego, and Sanford Consortium for Regenerative Medicine, La Jolla, CA, 92093, USA.
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12
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Xue Y, Georgakopoulou T, van der Wijk AE, Józsa TI, van Bavel E, Payne SJ. Quantification of hypoxic regions distant from occlusions in cerebral penetrating arteriole trees. PLoS Comput Biol 2022; 18:e1010166. [PMID: 35930591 PMCID: PMC9385041 DOI: 10.1371/journal.pcbi.1010166] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Revised: 08/17/2022] [Accepted: 07/14/2022] [Indexed: 11/18/2022] Open
Abstract
The microvasculature plays a key role in oxygen transport in the mammalian brain. Despite the close coupling between cerebral vascular geometry and local oxygen demand, recent experiments have reported that microvascular occlusions can lead to unexpected distant tissue hypoxia and infarction. To better understand the spatial correlation between the hypoxic regions and the occlusion sites, we used both in vivo experiments and in silico simulations to investigate the effects of occlusions in cerebral penetrating arteriole trees on tissue hypoxia. In a rat model of microembolisation, 25 μm microspheres were injected through the carotid artery to occlude penetrating arterioles. In representative models of human cortical columns, the penetrating arterioles were occluded by simulating the transport of microspheres of the same size and the oxygen transport was simulated using a Green’s function method. The locations of microspheres and hypoxic regions were segmented, and two novel distance analyses were implemented to study their spatial correlation. The distant hypoxic regions were found to be present in both experiments and simulations, and mainly due to the hypoperfusion in the region downstream of the occlusion site. Furthermore, a reasonable agreement for the spatial correlation between hypoxic regions and occlusion sites is shown between experiments and simulations, which indicates the good applicability of in silico models in understanding the response of cerebral blood flow and oxygen transport to microemboli. The brain function depends on the continuous oxygen supply through the bloodstream inside the microvasculature. Occlusions in the microvascular network will disturb the oxygen delivery in the brain and result in hypoxic tissues that can lead to infarction and cognitive dysfunction. To aid in understanding the formation of hypoxic tissues caused by micro-occlusions in the penetrating arteriole trees, we use rodent experiments and simulations of human vascular networks to study the spatial correlations between the hypoxic regions and the occlusion locations. Our results suggest that hypoxic regions can form distally from the occlusion site, which agrees with the previous observations in the rat brain. These distant hypoxic regions are primarily due to the lack of blood flow in the brain tissues downstream of the occlusion. Moreover, a reasonable agreement of the spatial relationship is found between the experiments and the simulations, which indicates the applicability of in silico models to study the effects of microemboli on the brain tissue.
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Affiliation(s)
- Yidan Xue
- Institute of Biomedical Engineering, Department of Engineering Science, University of Oxford, Oxford, United Kingdom
| | - Theodosia Georgakopoulou
- Department of Biomedical Engineering and Physics, Amsterdam University Medical Centers, University of Amsterdam, Amsterdam, The Netherlands
| | - Anne-Eva van der Wijk
- Department of Biomedical Engineering and Physics, Amsterdam University Medical Centers, University of Amsterdam, Amsterdam, The Netherlands
| | - Tamás I. Józsa
- Institute of Biomedical Engineering, Department of Engineering Science, University of Oxford, Oxford, United Kingdom
| | - Ed van Bavel
- Department of Biomedical Engineering and Physics, Amsterdam University Medical Centers, University of Amsterdam, Amsterdam, The Netherlands
| | - Stephen J. Payne
- Institute of Biomedical Engineering, Department of Engineering Science, University of Oxford, Oxford, United Kingdom
- Institute of Applied Mechanics, National Taiwan University, Taipei, Taiwan
- * E-mail:
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13
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Reeson P, Schager B, Van Sprengel M, Brown CE. Behavioral and Neural Activity-Dependent Recanalization of Plugged Capillaries in the Brain of Adult and Aged Mice. Front Cell Neurosci 2022; 16:876746. [PMID: 35722620 PMCID: PMC9204343 DOI: 10.3389/fncel.2022.876746] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Accepted: 04/12/2022] [Indexed: 11/13/2022] Open
Abstract
The capillaries of the brain, owing to their small diameter and low perfusion pressure, are vulnerable to interruptions in blood flow. These tiny occlusions can have outsized consequences on angioarchitecture and brain function; especially when exacerbated by disease states or accumulate with aging. A distinctive feature of the brain’s microvasculature is the ability for active neurons to recruit local blood flow. The coupling of neural activity to blood flow could play an important role in recanalizing obstructed capillaries. To investigate this idea, we experimentally induced capillary obstructions in mice by injecting fluorescent microspheres and then manipulated neural activity levels though behavioral or pharmacologic approaches. We show that engaging adult and aged mice with 12 h exposure to an enriched environment (group housing, novel objects, exercise wheels) was sufficient to significantly reduce the density of obstructed capillaries throughout the forebrain. In order to more directly manipulate neural activity, we pharmacologically suppressed or increased neuronal activity in the somatosensory cortex. When we suppressed cortical activity, recanalization was impaired given the density of obstructed capillaries was significantly increased. Conversely, increasing cortical activity improved capillary recanalization. Since systemic cardiovascular factors (changes in heart rate, blood pressure) could explain these effects on recanalization, we demonstrate that unilateral manipulations of neural activity through whisker trimming or injection of muscimol, still had significant and hemisphere specific effects on recanalization, even in mice exposed to enrichment where cardiovascular effects would be evident in both hemispheres. In summary, our studies reveal that neural activity bi-directionally regulates the recanalization of obstructed capillaries. Further, we show that stimulating brain activity through behavioral engagement (i.e., environmental enrichment) can promote vascular health throughout the lifespan.
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Affiliation(s)
- Patrick Reeson
- Division of Medical Sciences, University of Victoria, Victoria, BC, Canada
| | - Ben Schager
- Division of Medical Sciences, University of Victoria, Victoria, BC, Canada
| | | | - Craig E. Brown
- Division of Medical Sciences, University of Victoria, Victoria, BC, Canada
- Department of Psychiatry, University of British Columbia, Vancouver, BC, Canada
- *Correspondence: Craig E. Brown,
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14
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Localizing Microemboli within the Rodent Brain through Block-Face Imaging and Atlas Registration. eNeuro 2021; 8:ENEURO.0216-21.2021. [PMID: 34272259 PMCID: PMC8342264 DOI: 10.1523/eneuro.0216-21.2021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Revised: 06/27/2021] [Accepted: 07/07/2021] [Indexed: 12/01/2022] Open
Abstract
Brain microinfarcts are prevalent in humans, however because of the inherent difficulty of identifying and localizing individual microinfarcts, brain-wide quantification is impractical. In mice, microinfarcts have been created by surgically introducing microemboli into the brain, but a major limitation of this model is the absence of automated methods to identify and localize individual occlusions. We present a novel and semi-automated workflow to identify the anatomic location of fluorescent emboli (microspheres) within the mouse brain through histologic processing and atlas registration. By incorporating vibratome block-face imaging with the QuickNII brain registration tool, we show that the anatomic location of microspheres can be accurately registered to brain structures within the Allen mouse brain (AMB) atlas (e.g., somatomotor areas, hippocampal region, visual areas, etc.). Compared with registering images of slide mounted sections to the AMB atlas, microsphere location was more accurately determined when block-face images were used. As a proof of principle, using this workflow we compared the distribution of microspheres within the brains of mice that were either perfused or immersion fixed. No significant effect of perfusion on total microsphere number or location was detected. In general, microspheres were distributed brain-wide, with the largest density found in the thalamus. In sum, our block-face imaging workflow enables efficient characterization of the widespread distribution of fluorescent microemboli, facilitating future investigation into the impact of microinfarct load and location on brain health.
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15
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A simulation study investigating potential diffusion-based MRI signatures of microstrokes. Sci Rep 2021; 11:14229. [PMID: 34244549 PMCID: PMC8271016 DOI: 10.1038/s41598-021-93503-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Accepted: 06/22/2021] [Indexed: 02/06/2023] Open
Abstract
Recent studies suggested that cerebrovascular micro-occlusions, i.e. microstokes, could lead to ischemic tissue infarctions and cognitive deficits. Due to their small size, identifying measurable biomarkers of these microvascular lesions remains a major challenge. This work aims to simulate potential MRI signatures combining arterial spin labeling (ASL) and multi-directional diffusion-weighted imaging (DWI). Driving our hypothesis are recent observations demonstrating a radial reorientation of microvasculature around the micro-infarction locus during recovery in mice. Synthetic capillary beds, randomly- and radially-oriented, and optical coherence tomography (OCT) angiograms, acquired in the barrel cortex of mice (n = 5) before and after inducing targeted photothrombosis, were analyzed. Computational vascular graphs combined with a 3D Monte-Carlo simulator were used to characterize the magnetic resonance (MR) response, encompassing the effects of magnetic field perturbations caused by deoxyhemoglobin, and the advection and diffusion of the nuclear spins. We quantified the minimal intravoxel signal loss ratio when applying multiple gradient directions, at varying sequence parameters with and without ASL. With ASL, our results demonstrate a significant difference (p < 0.05) between the signal-ratios computed at baseline and 3 weeks after photothrombosis. The statistical power further increased (p < 0.005) using angiograms measured at week 4. Without ASL, no reliable signal change was found. We found that higher ratios, and accordingly improved significance, were achieved at lower magnetic field strengths (e.g., B0 = 3T) and shorter echo time TE (< 16 ms). Our simulations suggest that microstrokes might be characterized through ASL-DWI sequence, providing necessary insights for posterior experimental validations, and ultimately, future translational trials.
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16
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Abstract
The distribution of blood throughout the brain is facilitated by highly interconnected capillary networks. However, the steps involved in the construction of these networks has remained unclear. We used in vivo two-photon imaging through noninvasive cranial windows to study the engineering of capillary networks in the cerebral cortex of mouse neonates. We find that angiogenic activity originates at ascending venules, which undergo a burst of sprouting in the second postnatal week. This sprouting activity first establishes long paths to connect venules to blood input from neighboring arterioles, and then expands capillary interconnectivity with a multitude of short-range connections. Our study provides an experimental foundation to understand how capillary networks are shaped in the living mammalian brain during postnatal development. Capillary networks are essential for distribution of blood flow through the brain, and numerous other homeostatic functions, including neurovascular signal conduction and blood–brain barrier integrity. Accordingly, the impairment of capillary architecture and function lies at the root of many brain diseases. Visualizing how brain capillary networks develop in vivo can reveal innate programs for cerebrovascular growth and repair. Here, we use longitudinal two-photon imaging through noninvasive thinned skull windows to study a burst of angiogenic activity during cerebrovascular development in mouse neonates. We find that angiogenesis leading to the formation of capillary networks originated exclusively from cortical ascending venules. Two angiogenic sprouting activities were observed: 1) early, long-range sprouts that directly connected venules to upstream arteriolar input, establishing the backbone of the capillary bed, and 2) short-range sprouts that contributed to expansion of anastomotic connectivity within the capillary bed. All nascent sprouts were prefabricated with an intact endothelial lumen and pericyte coverage, ensuring their immediate perfusion and stability upon connection to their target vessels. The bulk of this capillary expansion spanned only 2 to 3 d and contributed to an increase of blood flow during a critical period in cortical development.
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17
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Schmid F, Conti G, Jenny P, Weber B. The severity of microstrokes depends on local vascular topology and baseline perfusion. eLife 2021; 10:60208. [PMID: 34003107 PMCID: PMC8421069 DOI: 10.7554/elife.60208] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Accepted: 05/17/2021] [Indexed: 01/26/2023] Open
Abstract
Cortical microinfarcts are linked to pathologies like cerebral amyloid angiopathy and dementia. Despite their relevance for disease progression, microinfarcts often remain undetected and the smallest scale of blood flow disturbance has not yet been identified. We employed blood flow simulations in realistic microvascular networks from the mouse cortex to quantify the impact of single-capillary occlusions. Our simulations reveal that the severity of a microstroke is strongly affected by the local vascular topology and the baseline flow rate in the occluded capillary. The largest changes in perfusion are observed in capillaries with two inflows and two outflows. This specific topological configuration only occurs with a frequency of 8%. The majority of capillaries have one inflow and one outflow and is likely designed to efficiently supply oxygen and nutrients. Taken together, microstrokes bear potential to induce a cascade of local disturbances in the surrounding tissue, which might accumulate and impair energy supply locally.
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Affiliation(s)
- Franca Schmid
- Institute of Pharmacology and Toxicology, University of Zurich, Zurich, Switzerland.,Institute of Fluid Dynamics, ETH Zurich, Zurich, Switzerland
| | - Giulia Conti
- Institute of Fluid Dynamics, ETH Zurich, Zurich, Switzerland
| | - Patrick Jenny
- Institute of Fluid Dynamics, ETH Zurich, Zurich, Switzerland
| | - Bruno Weber
- Institute of Pharmacology and Toxicology, University of Zurich, Zurich, Switzerland.,Neuroscience Center Zurich, University and ETH Zurich, Zurich, Switzerland
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18
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Reeson P, Brown CE. New Vistas in Stroke Treatment: Targeting the Endothelium to Restore Blood Flow. Circ Res 2021; 128:383-385. [PMID: 33539221 DOI: 10.1161/circresaha.121.318671] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Patrick Reeson
- Division of Medical Sciences, University of Victoria, BC, Canada (P.R., C.E.B.)
| | - Craig E Brown
- Division of Medical Sciences, University of Victoria, BC, Canada (P.R., C.E.B.).,Department of Psychiatry, University of British Columbia, Vancouver, Canada (C.E.B.)
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19
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Erdener ŞE, Tang J, Kılıç K, Postnov D, Giblin JT, Kura S, Chen ICA, Vayisoğlu T, Sakadžić S, Schaffer CB, Boas DA. Dynamic capillary stalls in reperfused ischemic penumbra contribute to injury: A hyperacute role for neutrophils in persistent traffic jams. J Cereb Blood Flow Metab 2021; 41:236-252. [PMID: 32237951 PMCID: PMC8370003 DOI: 10.1177/0271678x20914179] [Citation(s) in RCA: 63] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Ever since the introduction of thrombolysis and the subsequent expansion of endovascular treatments for acute ischemic stroke, it remains to be identified why the actual outcomes are less favorable despite recanalization. Here, by high spatio-temporal resolution imaging of capillary circulation in mice, we introduce the pathological phenomenon of dynamic flow stalls in cerebral capillaries, occurring persistently in salvageable penumbra after reperfusion. These stalls, which are different from permanent cellular plugs of no-reflow, were temporarily and repetitively occurring in the capillary network, impairing the overall circulation like small focal traffic jams. In vivo microscopy in the ischemic penumbra revealed leukocytes traveling slowly through capillary lumen or getting stuck, while red blood cell flow was being disturbed in the neighboring segments under reperfused conditions. Stall dynamics could be modulated, by injection of an anti-Ly6G antibody specifically targeting neutrophils. Decreased number and duration of stalls were associated with improvement in penumbral blood flow within 2-24 h after reperfusion along with increased capillary oxygenation, decreased cellular damage and improved functional outcome. Thereby, dynamic microcirculatory stall phenomenon can be a contributing factor to ongoing penumbral injury and is a potential hyperacute mechanism adding on previous observations of detrimental effects of activated neutrophils in ischemic stroke.
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Affiliation(s)
- Şefik E Erdener
- Neurophotonics Center, Department of Biomedical Engineering, Boston University, Boston, MA, USA.,Optics Division, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA
| | - Jianbo Tang
- Neurophotonics Center, Department of Biomedical Engineering, Boston University, Boston, MA, USA.,Optics Division, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA
| | - Kıvılcım Kılıç
- Neurophotonics Center, Department of Biomedical Engineering, Boston University, Boston, MA, USA
| | - Dmitry Postnov
- Neurophotonics Center, Department of Biomedical Engineering, Boston University, Boston, MA, USA.,Institute of Biomedical Sciences, Faculty of Health and Medical Sciences, Copenhagen University, Copenhagen, Denmark
| | - John T Giblin
- Neurophotonics Center, Department of Biomedical Engineering, Boston University, Boston, MA, USA
| | - Sreekanth Kura
- Neurophotonics Center, Department of Biomedical Engineering, Boston University, Boston, MA, USA
| | - I-Chun A Chen
- Neurophotonics Center, Department of Biomedical Engineering, Boston University, Boston, MA, USA
| | - Tuğberk Vayisoğlu
- Neurophotonics Center, Department of Biomedical Engineering, Boston University, Boston, MA, USA
| | - Sava Sakadžić
- Optics Division, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA
| | - Chris B Schaffer
- Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY, USA
| | - David A Boas
- Neurophotonics Center, Department of Biomedical Engineering, Boston University, Boston, MA, USA
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20
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Nie S, Shen C, Guo Y, Hou X, Hong Y, Xu S, Lv R, Liu X. Preliminary Findings on Visual Event-Related Potential P3 in Asymptomatic Patients with Cerebral Small Vessel Disease. Neuropsychiatr Dis Treat 2021; 17:3379-3394. [PMID: 34848959 PMCID: PMC8626861 DOI: 10.2147/ndt.s338717] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/10/2021] [Accepted: 11/09/2021] [Indexed: 01/12/2023] Open
Abstract
BACKGROUND Cerebral small vessel disease is the primary cause of cognitive impairment. Therefore, early recognition is of great significance. Some studies have shown that asymptomatic cerebral small vessel disease (aCSVD) patients have abnormal neurocognitive function, but this is not readily apparent at the initial stage. The objective of this paper was to assess visual spatial attention by event-related potential (ERP) examination and to analyze the relationship between ERP data and clinical characteristics in patients with aCSVD. METHODS We selected 25 aCSVD patients and enrolled 23 age-matched normal subjects as the control group. We measured the latency and amplitude of original/corresponding differential ERP components using the modified visual oddball paradigm, which included a standard stimulus, target stimulus, and new stimulus. Additionally, we selected aberrant ERP components to study the correlations between the ERP data and clinical characteristics of the patients with aCSVD. RESULTS We found not only lower amplitude but also significantly longer P3 latency in the aCSVD patients. The above results were further verified by analyzing the different components (target minus standard and novel minus standard) of P3. Furthermore, abnormal ERPs in the aCSVD patients were closely related to the changes observed with imaging. CONCLUSION It was demonstrated that the speed and capability of processing visual spatial information was impaired in aCSVD patients compared with healthy controls. Thus, ERP examination could detect the presence of attentional deficits and might become a rapid and sensitive method for the early diagnosis of aCSVD. However, its availability needs further investigation.
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Affiliation(s)
- Shanjing Nie
- Department of Geriatrics, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, Shandong, People's Republic of China.,Department of Geriatric Neurology, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, Shandong, People's Republic of China.,Anti-Aging Monitoring Laboratory, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, Shandong, People's Republic of China
| | - Chao Shen
- Department of Geriatrics, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, Shandong, People's Republic of China.,Department of Geriatric Neurology, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, Shandong, People's Republic of China
| | - Yunliang Guo
- Department of Geriatrics, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, Shandong, People's Republic of China.,Department of Geriatric Neurology, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, Shandong, People's Republic of China.,Anti-Aging Monitoring Laboratory, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, Shandong, People's Republic of China
| | - Xunyao Hou
- Department of Geriatrics, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, Shandong, People's Republic of China.,Department of Geriatric Neurology, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, Shandong, People's Republic of China.,Anti-Aging Monitoring Laboratory, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, Shandong, People's Republic of China
| | - Yan Hong
- Department of Geriatrics, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, Shandong, People's Republic of China.,Department of Geriatric Neurology, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, Shandong, People's Republic of China.,Anti-Aging Monitoring Laboratory, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, Shandong, People's Republic of China
| | - Song Xu
- Department of Geriatrics, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, Shandong, People's Republic of China.,Department of Geriatric Neurology, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, Shandong, People's Republic of China.,Anti-Aging Monitoring Laboratory, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, Shandong, People's Republic of China
| | - Renjun Lv
- Shandong Provincial Hospital, Shandong First Medical University & Shandong Academy of Medical Sciences, Jinan, Shandong, People's Republic of China
| | - Xueping Liu
- Department of Geriatrics, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, Shandong, People's Republic of China.,Department of Geriatric Neurology, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, Shandong, People's Republic of China.,Anti-Aging Monitoring Laboratory, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, Shandong, People's Republic of China
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21
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Watson AN, Berthiaume AA, Faino AV, McDowell KP, Bhat NR, Hartmann DA, Shih AY. Mild pericyte deficiency is associated with aberrant brain microvascular flow in aged PDGFRβ +/- mice. J Cereb Blood Flow Metab 2020; 40:2387-2400. [PMID: 31987006 PMCID: PMC7820684 DOI: 10.1177/0271678x19900543] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The receptor tyrosine kinase PDGFRβ is essential for pericyte migration to the endothelium. In mice lacking one allele of PDGFRβ (PDGFRβ+/-), previous reports have described an age-dependent loss of pericytes in the brain, leading to cerebrovascular dysfunction and subsequent neurodegeneration reminiscent of that seen in Alzheimer's disease and vascular dementia. We examined 12-20-month-old PDGFRβ+/- mice to better understand how pericyte loss affects brain microvascular structure and perfusion in vivo. We observed a mild reduction of cortical pericyte number in PDGFRβ+/- mice (27% fewer cell bodies) compared to controls, but no decrease in pericyte coverage of the endothelium. This mild degree of pericyte loss caused no discernable change in cortical microvascular density, length, basal diameter or reactivity to hypercapnia. Yet, it was associated with an increase in basal blood cell velocity, primarily in pre-capillary arterioles. Taken together, our results suggest that mild pericyte loss can lead to aberrant cerebral blood flow despite a lack of apparent effect on microvascular structure and reactivity.
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Affiliation(s)
- Ashley N Watson
- Department of Neuroscience, Medical University of South Carolina, Charleston, SC, USA
| | - Andree-Anne Berthiaume
- Department of Neuroscience, Medical University of South Carolina, Charleston, SC, USA.,Center for Developmental Biology and Regenerative Medicine, Seattle Children's Research Institute, Seattle, WA, USA
| | - Anna V Faino
- Children's Core for Biomedical Statistics, Seattle Children's Research Institute, Seattle, WA, USA
| | - Konnor P McDowell
- Department of Neuroscience, Medical University of South Carolina, Charleston, SC, USA.,Center for Developmental Biology and Regenerative Medicine, Seattle Children's Research Institute, Seattle, WA, USA
| | - Narayan R Bhat
- Department of Neuroscience, Medical University of South Carolina, Charleston, SC, USA
| | - David A Hartmann
- Department of Neuroscience, Medical University of South Carolina, Charleston, SC, USA
| | - Andy Y Shih
- Department of Neuroscience, Medical University of South Carolina, Charleston, SC, USA.,Center for Developmental Biology and Regenerative Medicine, Seattle Children's Research Institute, Seattle, WA, USA.,Children's Core for Biomedical Statistics, Seattle Children's Research Institute, Seattle, WA, USA.,Department of Pediatrics, University of Washington, Seattle, WA, USA
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22
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Zhang Y, Bander ED, Lee Y, Muoser C, Schaffer CB, Nishimura N. Microvessel occlusions alter amyloid-beta plaque morphology in a mouse model of Alzheimer's disease. J Cereb Blood Flow Metab 2020; 40:2115-2131. [PMID: 31744388 PMCID: PMC7786844 DOI: 10.1177/0271678x19889092] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/28/2019] [Revised: 09/04/2019] [Accepted: 10/03/2019] [Indexed: 11/16/2022]
Abstract
Vascular dysfunction is correlated to the incidence and severity of Alzheimer's disease. In a mouse model of Alzheimer's disease (APP/PS1) using in vivo, time-lapse, multiphoton microscopy, we found that occlusions of the microvasculature alter amyloid-beta (Aβ) plaques. We used several models of vascular injury that varied in severity. Femtosecond laser-induced occlusions in single capillaries generated a transient increase in small, cell-sized, Aβ deposits visualized with methoxy-X04, a label of fibrillar Aβ. After occlusions of penetrating arterioles, some plaques changed morphology, while others disappeared, and some new plaques appeared within a week after the lesion. Antibody labeling of Aβ revealed a transient increase in non-fibrillar Aβ one day after the occlusion that coincided with the disappearance of methoxy-X04-labeled plaques. Four days after the lesion, anti-Aβ labeling decreased and only remained in patches unlabeled by methoxy-X04 near microglia. Histology in two additional models, sparse embolic occlusions from intracarotid injections of beads and infarction from photothrombosis, demonstrated increased labeling intensity in plaques after injury. These results suggest that microvascular lesions can alter the deposition and clearance of Aβ and confirm that Aβ plaques are dynamic structures, complicating the interpretation of plaque burden as a marker of Alzheimer's disease progression.
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Affiliation(s)
- Yuying Zhang
- Nancy E. and Peter C. Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY, USA
| | - Evan D Bander
- Nancy E. and Peter C. Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY, USA
| | - Yurim Lee
- Nancy E. and Peter C. Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY, USA
| | - Celia Muoser
- Nancy E. and Peter C. Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY, USA
| | - Chris B Schaffer
- Nancy E. and Peter C. Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY, USA
| | - Nozomi Nishimura
- Nancy E. and Peter C. Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY, USA
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23
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Williamson MR, Franzen RL, Fuertes CJA, Dunn AK, Drew MR, Jones TA. A Window of Vascular Plasticity Coupled to Behavioral Recovery after Stroke. J Neurosci 2020; 40:7651-7667. [PMID: 32873722 PMCID: PMC7531554 DOI: 10.1523/jneurosci.1464-20.2020] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Revised: 08/03/2020] [Accepted: 08/25/2020] [Indexed: 12/13/2022] Open
Abstract
Stroke causes remodeling of vasculature surrounding the infarct, but whether and how vascular remodeling contributes to recovery are unclear. We established an approach to monitor and compare changes in vascular structure and blood flow with high spatiotemporal precision after photothrombotic infarcts in motor cortex using longitudinal 2-photon and multiexposure speckle imaging in mice of both sexes. A spatially graded pattern of vascular structural remodeling in peri-infarct cortex unfolded over the first 2 weeks after stroke, characterized by vessel loss and formation, and selective stabilization of a subset of new vessels. This vascular structural plasticity was coincident with transient activation of transcriptional programs relevant for vascular remodeling, reestablishment of peri-infarct blood flow, and large improvements in motor performance. Local vascular plasticity was strongly predictive of restoration of blood flow, which was in turn predictive of behavioral recovery. These findings reveal the spatiotemporal evolution of vascular remodeling after stroke and demonstrate that a window of heightened vascular plasticity is coupled to the reestablishment of blood flow and behavioral recovery. Our findings support that neovascularization contributes to behavioral recovery after stroke by restoring blood flow to peri-infarct regions. These findings may inform strategies for enhancing recovery from stroke and other types of brain injury.SIGNIFICANCE STATEMENT An improved understanding of neural repair could inform strategies for enhancing recovery from stroke and other types of brain injury. Stroke causes remodeling of vasculature surrounding the lesion, but whether and how the process of vascular remodeling contributes to recovery of behavioral function have been unclear. Here we used longitudinal in vivo imaging to track vascular structure and blood flow in residual peri-infarct cortex after ischemic stroke in mice. We found that stroke created a restricted period of heightened vascular plasticity that was associated with restoration of blood flow, which was in turn predictive of recovery of motor function. Therefore, our findings support that vascular remodeling facilitates behavioral recovery after stroke by restoring blood flow to peri-infarct cortex.
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Affiliation(s)
| | | | | | - Andrew K Dunn
- Institute for Neuroscience
- Department of Biomedical Engineering
| | - Michael R Drew
- Institute for Neuroscience
- Center for Learning and Memory and Department of Neuroscience, University of Texas at Austin, Austin, Texas 78712
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24
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Lubart A, Benbenishty A, Har-Gil H, Laufer H, Gdalyahu A, Assaf Y, Blinder P. Single Cortical Microinfarcts Lead to Widespread Microglia/Macrophage Migration Along the White Matter. Cereb Cortex 2020; 31:248-266. [PMID: 32954425 DOI: 10.1093/cercor/bhaa223] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2018] [Revised: 05/13/2020] [Accepted: 06/08/2020] [Indexed: 12/31/2022] Open
Abstract
Loss of cognitive function with aging is a complex and poorly understood process. Recently, clinical research has linked the occurrence of cortical microinfarcts to cognitive decline. Cortical microinfarcts form following the occlusion of penetrating vessels and are considered to be restricted to the proximity of the occluded vessel. Whether and how such local events propagate and affect remote brain regions remain unknown. To this end, we combined histological analysis and longitudinal diffusion tensor imaging (DTI), following the targeted-photothrombotic occlusion of single cortical penetrating vessels. Occlusions resulted in distant tissue reorganization across the mouse brain. This remodeling co-occurred with the formation of a microglia/macrophage migratory path along subcortical white matter tracts, reaching the contralateral hemisphere through the corpus callosum and leaving a microstructural signature detected by DTI-tractography. CX3CR1-deficient mice exhibited shorter trail lengths, differential remodeling, and only ipsilateral white matter tract changes. We concluded that microinfarcts lead to brain-wide remodeling in a microglial CX3CR1-dependent manner.
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Affiliation(s)
- Alisa Lubart
- Sagol School of Neuroscience, Tel Aviv University, Tel Aviv-Yafo, Israel
| | - Amit Benbenishty
- Sagol School of Neuroscience, Tel Aviv University, Tel Aviv-Yafo, Israel.,Biological Regulation Department, The Weizmann Institute of Science, Rehovot, Israel
| | - Hagai Har-Gil
- Sagol School of Neuroscience, Tel Aviv University, Tel Aviv-Yafo, Israel
| | - Hadas Laufer
- Sagol School of Neuroscience, Tel Aviv University, Tel Aviv-Yafo, Israel
| | - Amos Gdalyahu
- Neurobiology, Biochemistry and Biophysics School, Tel Aviv University, Tel Aviv-Yafo, Israel
| | - Yaniv Assaf
- Sagol School of Neuroscience, Tel Aviv University, Tel Aviv-Yafo, Israel.,Neurobiology, Biochemistry and Biophysics School, Tel Aviv University, Tel Aviv-Yafo, Israel
| | - Pablo Blinder
- Sagol School of Neuroscience, Tel Aviv University, Tel Aviv-Yafo, Israel.,Neurobiology, Biochemistry and Biophysics School, Tel Aviv University, Tel Aviv-Yafo, Israel
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25
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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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26
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Grant RI, Hartmann DA, Underly RG, Berthiaume AA, Bhat NR, Shih AY. Organizational hierarchy and structural diversity of microvascular pericytes in adult mouse cortex. J Cereb Blood Flow Metab 2019; 39:411-425. [PMID: 28933255 PMCID: PMC6399730 DOI: 10.1177/0271678x17732229] [Citation(s) in RCA: 155] [Impact Index Per Article: 31.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Smooth muscle cells and pericytes, together called mural cells, coordinate many distinct vascular functions. Canonically, smooth muscle cells are ring-shaped and cover arterioles with circumferential processes, whereas pericytes extend thin processes that run longitudinally along capillaries. In between these canonical mural cell types are cells with features of both smooth muscle cells and pericytes. Recent studies suggest that these transitional cells are critical for controlling blood flow to the capillary bed during health and disease, but there remains confusion on how to identify them and where they are located in the brain microvasculature. To address this issue, we measured the morphology, vascular territory, and α-smooth muscle actin content of structurally diverse mural cells in adult mouse cortex. We first imaged intact 3D vascular networks to establish the locations of major gradations in mural cell appearance as arterioles branched into capillaries. We then imaged individual mural cells occupying the regions within these gradations. This revealed two transitional cells that were often similar in appearance, but with sharply contrasting levels of α-smooth muscle actin. Our findings highlight the diversity of mural cell morphologies in brain microvasculature, and provide guidance for identification and categorization of mural cell types.
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Affiliation(s)
- Roger I Grant
- 1 Department of Neuroscience, Medical University of South Carolina, Charleston, SC, USA
| | - David A Hartmann
- 1 Department of Neuroscience, Medical University of South Carolina, Charleston, SC, USA
| | - Robert G Underly
- 1 Department of Neuroscience, Medical University of South Carolina, Charleston, SC, USA
| | | | - Narayan R Bhat
- 1 Department of Neuroscience, Medical University of South Carolina, Charleston, SC, USA
| | - Andy Y Shih
- 1 Department of Neuroscience, Medical University of South Carolina, Charleston, SC, USA.,2 Center for Biomedical Imaging, Medical University of South Carolina, Charleston, SC, USA
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27
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Hyacinth HI, Sugihara CL, Spencer TL, Archer DR, Shih AY. Higher prevalence of spontaneous cerebral vasculopathy and cerebral infarcts in a mouse model of sickle cell disease. J Cereb Blood Flow Metab 2019; 39:342-351. [PMID: 28925802 PMCID: PMC6365608 DOI: 10.1177/0271678x17732275] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Stroke is a dramatic complication of sickle cell disease (SCD), which is associated with cerebral vasculopathies including moya moya, intravascular thrombi, cerebral hyperemia, and increased vessel tortuosity. The spontaneous occurrence of these pathologies in the sickle cell mouse model has not been described. Here, we studied Townes humanized sickle cell and age-matched control mice that were 13 months old. We used in vivo two-photon microscopy to assess blood flow dynamics, vascular topology, and evidence of cerebral vasculopathy. Results showed that compared to controls, sickle cell mice had significantly higher red blood cell (RBC) velocity (0.73 mm/s vs. 0.55 mm/s, p = 0.013), capillary vessel diameter (4.84 µM vs. 4.50 µM, p = 0.014), and RBC volume flux (0.015 nL/s vs. 0.010 nL/s, p = 0.021). Also, sickle cell mice had significantly more tortuous capillary vessels ( p < 0.0001) and significantly shorter capillary vessel branches ( p = 0.0065) compared to controls. Sickle cell mice also had significantly higher number of capillary occlusive events (3.4% vs. 1.9%, p < 0.0001) and RBC stalls (3.8% vs. 2.1%, p < 0.0001) in the cerebral capillary bed. In post-mortem immunohistochemical analyses, sickle cell mice had a 2.5-fold higher frequency of cortical microinfarcts compared to control mice. Our results suggest that aged Townes sickle cell mice spontaneously develop SCD-associated cerebral vasculopathy.
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Affiliation(s)
- Hyacinth I Hyacinth
- 1 Department of Pediatrics, Aflac Cancer and Blood Disorder Center of Children's Healthcare of Atlanta and Emory University, Atlanta, GA, USA
| | - Courtney L Sugihara
- 2 Neuroscience and Behavioral Biology Program, Emory University, Atlanta, GA, USA
| | - Thomas L Spencer
- 3 Department of Mechanical Engineering, Georgia Technical Institute, Atlanta, GA, USA
| | - David R Archer
- 1 Department of Pediatrics, Aflac Cancer and Blood Disorder Center of Children's Healthcare of Atlanta and Emory University, Atlanta, GA, USA
| | - Andy Y Shih
- 4 Department of Neurosciences, Medical University of South Carolina, Charleston, SC, USA.,5 Center for Biomedical Imaging, Medical University of South Carolina, Charleston, SC, USA
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28
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Hierro-Bujalance C, Bacskai BJ, Garcia-Alloza M. In Vivo Imaging of Microglia With Multiphoton Microscopy. Front Aging Neurosci 2018; 10:218. [PMID: 30072888 PMCID: PMC6060250 DOI: 10.3389/fnagi.2018.00218] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2018] [Accepted: 06/26/2018] [Indexed: 01/04/2023] Open
Abstract
Neuroimaging has become an unparalleled tool to understand the central nervous system (CNS) anatomy, physiology and neurological diseases. While an altered immune function and microglia hyperactivation are common neuropathological features for many CNS disorders and neurodegenerative diseases, direct assessment of the role of microglial cells remains a challenging task. Non-invasive neuroimaging techniques, including magnetic resonance imaging (MRI), positron emission tomography (PET) and single positron emission computed tomography (SPECT) are widely used for human clinical applications, and a variety of ligands are available to detect neuroinflammation. In animal models, intravital imaging has been largely used, and minimally invasive multiphoton microcopy (MPM) provides high resolution detection of single microglia cells, longitudinally, in living brain. In this study, we review in vivo real-time MPM approaches to assess microglia in preclinical studies, including individual cell responses in surveillance, support, protection and restoration of brain tissue integrity, synapse formation, homeostasis, as well as in different pathological situations. We focus on in vivo studies that assess the role of microglia in mouse models of Alzheimer’s disease (AD), analyzing microglial motility and recruitment, as well as the role of microglia in anti-amyloid-β treatment, as a key therapeutic approach to treat AD. Altogether, MPM provides a high contrast and high spatial resolution approach to follow microglia chronically in vivo in complex models, supporting MPM as a powerful tool for deep intravital tissue imaging.
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Affiliation(s)
- Carmen Hierro-Bujalance
- Division of Physiology, School of Medicine, Instituto de Investigación e Innovación en Ciencias Biomedicas de la Provincia de Cadiz (INiBICA), Universidad de Cádiz, Cádiz, Spain
| | - Brian J Bacskai
- Alzheimer Research Unit, Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Harvard University, Boston, MA, United States
| | - Monica Garcia-Alloza
- Division of Physiology, School of Medicine, Instituto de Investigación e Innovación en Ciencias Biomedicas de la Provincia de Cadiz (INiBICA), Universidad de Cádiz, Cádiz, Spain
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29
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The pial vasculature of the mouse develops according to a sensory-independent program. Sci Rep 2018; 8:9860. [PMID: 29959346 PMCID: PMC6026131 DOI: 10.1038/s41598-018-27910-3] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2018] [Accepted: 06/12/2018] [Indexed: 12/15/2022] Open
Abstract
The cerebral vasculature is organized to supply the brain’s metabolic needs. Sensory deprivation during the early postnatal period causes altered neural activity and lower metabolic demand. Neural activity is instructional for some aspects of vascular development, and deprivation causes changes in capillary density in the deprived brain region. However, it is not known if the pial arteriole network, which contains many leptomeningeal anastomoses (LMAs) that endow the network with redundancy against occlusions, is also affected by sensory deprivation. We quantified the effects of early-life sensory deprivation via whisker plucking on the densities of LMAs and penetrating arterioles (PAs) in anatomically-identified primary sensory regions (vibrissae cortex, forelimb/hindlimb cortex, visual cortex and auditory cortex) in mice. We found that the densities of penetrating arterioles were the same across cortical regions, though the hindlimb representation had a higher density of LMAs than other sensory regions. We found that the densities of PAs and LMAs, as well as quantitative measures of network topology, were not affected by sensory deprivation. Our results show that the postnatal development of the pial arterial network is robust to sensory deprivation.
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30
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Pires PW. Cannabinoids during ischemic strokes: friends or foes? Am J Physiol Heart Circ Physiol 2018; 314:H1155-H1156. [PMID: 29522356 PMCID: PMC6032081 DOI: 10.1152/ajpheart.00107.2018] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/07/2018] [Revised: 02/28/2018] [Accepted: 03/05/2018] [Indexed: 02/01/2023]
Affiliation(s)
- Paulo W Pires
- Department of Pharmacology, Center for Cardiovascular Research, Reno School of Medicine, University of Nevada , Reno, Nevada
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31
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Hartmann DA, Hyacinth HI, Liao FF, Shih AY. Does pathology of small venules contribute to cerebral microinfarcts and dementia? J Neurochem 2018; 144:517-526. [PMID: 28950410 PMCID: PMC5869083 DOI: 10.1111/jnc.14228] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2017] [Revised: 09/08/2017] [Accepted: 09/18/2017] [Indexed: 12/28/2022]
Abstract
Microinfarcts are small, but strikingly common, ischemic brain lesions in the aging human brain. There is mounting evidence that microinfarcts contribute to vascular cognitive impairment and dementia, but the origins of microinfarcts are unclear. Understanding the vascular pathologies that cause microinfarcts may yield strategies to prevent their occurrence and reduce their deleterious effects on brain function. Current thinking suggests that cortical microinfarcts arise from the occlusion of penetrating arterioles, which are responsible for delivering oxygenated blood to small volumes of tissue. Unexpectedly, pre-clinical studies have shown that the occlusion of penetrating venules, which drain deoxygenated blood from cortex, lead to microinfarcts that appear identical to those resulting from arteriole occlusion. Here we discuss the idea that cerebral venule pathology could be an overlooked source for brain microinfarcts in humans. This article is part of the Special Issue "Vascular Dementia". Cover Image for this Issue: doi: 10.1111/jnc.14167.
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Affiliation(s)
- David A. Hartmann
- Department of Neurosciences, Medical University of South Carolina, Charleston, SC, USA
| | - Hyacinth I. Hyacinth
- Aflac Cancer and Blood Disorder Center, Children’s Healthcare of Atlanta and Emory University Department of Pediatrics, Atlanta, USA
| | - Francesca-Fang Liao
- Department of Pharmacology, The University of Tennessee Health Science Center, Memphis, Tennessee, USA
| | - Andy Y. Shih
- Department of Neurosciences, Medical University of South Carolina, Charleston, SC, USA
- Center for Biomedical Imaging, Medical University of South Carolina, Charleston, SC, USA
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32
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Shih AY, Hyacinth HI, Hartmann DA, van Veluw SJ. Rodent Models of Cerebral Microinfarct and Microhemorrhage. Stroke 2018; 49:803-810. [PMID: 29459393 DOI: 10.1161/strokeaha.117.016995] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2017] [Revised: 12/21/2017] [Accepted: 01/09/2018] [Indexed: 12/25/2022]
Affiliation(s)
- Andy Y Shih
- From the Department of Neuroscience (A.Y.S., D.A.H.) and Center for Biomedical Imaging (A.Y.S.), Medical University of South Carolina, Charleston, SC; Aflac Cancer and Blood Disorder Center, Children's Healthcare of Atlanta and Emory University Department of Pediatrics, GA (H.I.H.); and Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Boston, MA (S.J.v.V.).
| | - Hyacinth I Hyacinth
- From the Department of Neuroscience (A.Y.S., D.A.H.) and Center for Biomedical Imaging (A.Y.S.), Medical University of South Carolina, Charleston, SC; Aflac Cancer and Blood Disorder Center, Children's Healthcare of Atlanta and Emory University Department of Pediatrics, GA (H.I.H.); and Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Boston, MA (S.J.v.V.)
| | - David A Hartmann
- From the Department of Neuroscience (A.Y.S., D.A.H.) and Center for Biomedical Imaging (A.Y.S.), Medical University of South Carolina, Charleston, SC; Aflac Cancer and Blood Disorder Center, Children's Healthcare of Atlanta and Emory University Department of Pediatrics, GA (H.I.H.); and Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Boston, MA (S.J.v.V.)
| | - Susanne J van Veluw
- From the Department of Neuroscience (A.Y.S., D.A.H.) and Center for Biomedical Imaging (A.Y.S.), Medical University of South Carolina, Charleston, SC; Aflac Cancer and Blood Disorder Center, Children's Healthcare of Atlanta and Emory University Department of Pediatrics, GA (H.I.H.); and Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Boston, MA (S.J.v.V.)
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33
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Summers PM, Hartmann DA, Hui ES, Nie X, Deardorff RL, McKinnon ET, Helpern JA, Jensen JH, Shih AY. Functional deficits induced by cortical microinfarcts. J Cereb Blood Flow Metab 2017; 37:3599-3614. [PMID: 28090802 PMCID: PMC5669342 DOI: 10.1177/0271678x16685573] [Citation(s) in RCA: 78] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Clinical studies have revealed a strong link between increased burden of cerebral microinfarcts and risk for cognitive impairment. Since the sum of tissue damage incurred by microinfarcts is a miniscule percentage of total brain volume, we hypothesized that microinfarcts disrupt brain function beyond the injury site visible to histological or radiological examination. We tested this idea using a mouse model of microinfarcts, where single penetrating vessels that supply mouse cortex were occluded by targeted photothrombosis. We found that in vivo structural and diffusion MRI reliably reported the acute microinfarct core, based on spatial co-registrations with post-mortem stains of neuronal viability. Consistent with our hypothesis, c-Fos assays for neuronal activity and in vivo imaging of single vessel hemodynamics both reported functional deficits in viable peri-lesional tissues beyond the microinfarct core. We estimated that the volume of tissue with functional deficit in cortex was at least 12-fold greater than the volume of the microinfarct core. Impaired hemodynamic responses in peri-lesional tissues persisted at least 14 days, and were attributed to lasting deficits in neuronal circuitry or neurovascular coupling. These data show how individually miniscule microinfarcts could contribute to broader brain dysfunction during vascular cognitive impairment and dementia.
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Affiliation(s)
- Philipp M Summers
- 1 Department of Neurosciences, Medical University of South Carolina, Charleston, SC, USA
| | - David A Hartmann
- 1 Department of Neurosciences, Medical University of South Carolina, Charleston, SC, USA
| | - Edward S Hui
- 2 Department of Diagnostic Radiology, The University of Hong Kong, Hong Kong
| | - Xingju Nie
- 3 Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC, USA.,4 Center for Biomedical Imaging, Medical University of South Carolina, Charleston, SC, USA
| | - Rachael L Deardorff
- 3 Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC, USA.,4 Center for Biomedical Imaging, Medical University of South Carolina, Charleston, SC, USA
| | - Emilie T McKinnon
- 3 Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC, USA.,4 Center for Biomedical Imaging, Medical University of South Carolina, Charleston, SC, USA
| | - Joseph A Helpern
- 1 Department of Neurosciences, Medical University of South Carolina, Charleston, SC, USA.,3 Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC, USA.,4 Center for Biomedical Imaging, Medical University of South Carolina, Charleston, SC, USA
| | - Jens H Jensen
- 3 Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC, USA.,4 Center for Biomedical Imaging, Medical University of South Carolina, Charleston, SC, USA
| | - Andy Y Shih
- 1 Department of Neurosciences, Medical University of South Carolina, Charleston, SC, USA.,4 Center for Biomedical Imaging, Medical University of South Carolina, Charleston, SC, USA
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34
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van Veluw SJ, Shih AY, Smith EE, Chen C, Schneider JA, Wardlaw JM, Greenberg SM, Biessels GJ. Detection, risk factors, and functional consequences of cerebral microinfarcts. Lancet Neurol 2017; 16:730-740. [PMID: 28716371 PMCID: PMC5861500 DOI: 10.1016/s1474-4422(17)30196-5] [Citation(s) in RCA: 204] [Impact Index Per Article: 29.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2017] [Revised: 04/17/2017] [Accepted: 06/01/2017] [Indexed: 02/07/2023]
Abstract
Cerebral microinfarcts are small lesions that are presumed to be ischaemic. Despite the small size of these lesions, affected individuals can have hundreds to thousands of cerebral microinfarcts, which cause measurable disruption to structural brain connections, and are associated with dementia that is independent of Alzheimer's disease pathology or larger infarcts (ie, lacunar infarcts, and large cortical and non-lacunar subcortical infarcts). Substantial progress has been made with regard to understanding risk factors and functional consequences of cerebral microinfarcts, partly driven by new in-vivo detection methods and the development of animal models that closely mimic multiple aspects of cerebral microinfarcts in human beings. Evidence from these advances suggests that cerebral microinfarcts can be manifestations of both small vessel and large vessel disease, that cerebral microinfarcts are independently associated with cognitive impairment, and that these lesions are likely to cause damage to brain structure and function that extends beyond their actual lesion boundaries. Criteria for the identification of cerebral microinfarcts with in-vivo MRI are provided to support further studies of the association between these lesions and cerebrovascular disease and dementia.
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Affiliation(s)
- Susanne J van Veluw
- Department of Neurology, Brain Center Rudolf Magnus, University Medical Center Utrecht, Utrecht, Netherlands; Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Andy Y Shih
- Department of Neuroscience, Medical University of South Carolina, Charleston, SC, USA
| | - Eric E Smith
- Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Christopher Chen
- Memory Ageing and Cognition Centre, National University Health System, Singapore
| | - Julie A Schneider
- Rush Alzheimer's Disease Center, Rush University Medical Center, Chicago, IL, USA
| | - Joanna M Wardlaw
- Centre for Clinical Brain Sciences and Centre for Cognitive Ageing and Cognitive Epidemiology, University of Edinburgh, Edinburgh, UK
| | - Steven M Greenberg
- Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Geert Jan Biessels
- Department of Neurology, Brain Center Rudolf Magnus, University Medical Center Utrecht, Utrecht, Netherlands.
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35
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Pericytes as Inducers of Rapid, Matrix Metalloproteinase-9-Dependent Capillary Damage during Ischemia. J Neurosci 2017; 37:129-140. [PMID: 28053036 DOI: 10.1523/jneurosci.2891-16.2016] [Citation(s) in RCA: 127] [Impact Index Per Article: 18.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2016] [Revised: 10/20/2016] [Accepted: 11/01/2016] [Indexed: 11/21/2022] Open
Abstract
Blood-brain barrier disruption (BBB) and release of toxic blood molecules into the brain contributes to neuronal injury during stroke and other cerebrovascular diseases. While pericytes are builders and custodians of the BBB in the normal brain, their impact on BBB integrity during ischemia remains unclear. We imaged pericyte-labeled transgenic mice with in vivo two-photon microscopy to examine the relationship between pericytes and blood plasma leakage during photothrombotic occlusion of cortical capillaries. Upon cessation of capillary flow, we observed that plasma leakage occurred with three times greater frequency in regions where pericyte somata adjoined the endothelium. Pericyte somata covered only 7% of the total capillary length in cortex, indicating that a disproportionate amount of leakage occurred from a small fraction of the capillary bed. Plasma leakage was preceded by rapid activation of matrix metalloproteinase (MMP) at pericyte somata, which was visualized at high resolution in vivo using a fluorescent probe for matrix metalloproteinase-2/9 activity, fluorescein isothiocyanate (FITC)-gelatin. Coinjection of an MMP-9 inhibitor, but not an MMP-2 inhibitor, reduced pericyte-associated FITC-gelatin fluorescence and plasma leakage. These results suggest that pericytes contribute to rapid and localized proteolytic degradation of the BBB during cerebral ischemia. SIGNIFICANCE STATEMENT Pericytes are a key component of the neurovascular unit and are essential for normal BBB function. However, during acute ischemia, we find that pericytes are involved in creating rapid and heterogeneous BBB disruption in the capillary bed. The mechanism by which pericytes contribute to BBB damage warrants further investigation, as it may yield new therapeutic targets for acute stroke injury and other neurological diseases involving capillary flow impairment.
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Islam MM, Tsujikawa T, Mori T, Kiyono Y, Okazawa H. Pixel-by-pixel precise delay correction for measurement of cerebral hemodynamic parameters in H 215O PET study. Ann Nucl Med 2017; 31:283-294. [PMID: 28243845 PMCID: PMC5397462 DOI: 10.1007/s12149-017-1156-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2017] [Accepted: 01/30/2017] [Indexed: 11/25/2022]
Abstract
OBJECTIVE A new method of delay time estimation was proposed to measure precise cerebral blood flow (CBF) and arterial-to-capillary blood volume (V 0) using 15O-water PET. METHODS Nineteen patients with unilateral arterial stenoocclusive lesions were studied to evaluate hemodynamic status before treatment. The delay time of each pixel was calculated using least squares fitting with an arterial blood input curve adjusted to the internal carotid artery counts at the skull base. Pixel-by-pixel delay estimation provided a delay map image that could be used for precise calculation of CBF and V 0 using a one-tissue compartment model, and the values from this method were compared with those from the slice-by-slice correction method. RESULTS The affected side showed a longer delay time than the contralateral cerebral hemisphere. Although the mean cortical CBF values were not different between the two methods, the slice-by-slice delay correction overestimated CBF in the hypo perfused area. The scatter plot of V 0 pixel values showed significant difference between the two correction methods where the slice-by-slice delay correction significantly overestimated V 0 in the whole brain (P < 0.05). CONCLUSION Pixel-by-pixel delay correction provides delay images as well as better estimation of CBF and V 0, thus offering useful and beneficial information for the treatment of cerebrovascular disease.
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Affiliation(s)
- Muhammad M Islam
- Biomedical Imaging Research Center, University of Fukui, 23-3, Matsuoka-Shimaizuki, Eiheiji-cho, Fukui, 910-1193, Japan
| | - Tetsuya Tsujikawa
- Biomedical Imaging Research Center, University of Fukui, 23-3, Matsuoka-Shimaizuki, Eiheiji-cho, Fukui, 910-1193, Japan
| | - Tetsuya Mori
- Biomedical Imaging Research Center, University of Fukui, 23-3, Matsuoka-Shimaizuki, Eiheiji-cho, Fukui, 910-1193, Japan
| | - Yasushi Kiyono
- Biomedical Imaging Research Center, University of Fukui, 23-3, Matsuoka-Shimaizuki, Eiheiji-cho, Fukui, 910-1193, Japan
| | - Hidehiko Okazawa
- Biomedical Imaging Research Center, University of Fukui, 23-3, Matsuoka-Shimaizuki, Eiheiji-cho, Fukui, 910-1193, Japan.
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