101
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McDowell KP, Berthiaume AA, Tieu T, Hartmann DA, Shih AY. VasoMetrics: unbiased spatiotemporal analysis of microvascular diameter in multi-photon imaging applications. Quant Imaging Med Surg 2021; 11:969-982. [PMID: 33654670 PMCID: PMC7829163 DOI: 10.21037/qims-20-920] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Accepted: 11/17/2020] [Indexed: 01/13/2023]
Abstract
BACKGROUND Multi-photon imaging of the cerebrovasculature provides rich data on the dynamics of cortical arterioles, capillaries, and venules. Vascular diameter is the major determinant of blood flow resistance, and is the most commonly quantified metric in studies of the cerebrovasculature. However, there is a lack of accessible and easy-to-use methods to quantify vascular diameter in imaging data. METHODS We created VasoMetrics, a macro written in ImageJ/Fiji for spatiotemporal analysis of microvascular diameter. The key feature of VasoMetrics is rapid analysis of many evenly spaced cross-sectional lines along the vessel of interest, permitting the extraction of numerous diameter measurements from individual vessels. Here we demonstrated the utility of VasoMetrics by analyzing in vivo multi-photon imaging stacks and movies collected from lightly sedated mice, as well as data from optical coherence tomography angiography (OCTA) of human retina. RESULTS Compared to the standard approach, which is to measure cross-sectional diameters at arbitrary points along a vessel, VasoMetrics accurately reported spatiotemporal features of vessel diameter, reduced measurement bias and time spent analyzing data, and improved the reproducibility of diameter measurements between users. VasoMetrics revealed the dynamics in pial arteriole diameters during vasomotion at rest, as well as changes in capillary diameter before and after pericyte ablation. Retinal arteriole diameter was quantified from a human retinal angiogram, providing proof-of-principle that VasoMetrics can be applied to contrast-enhanced clinical imaging of microvasculature. CONCLUSIONS VasoMetrics is a robust macro for spatiotemporal analysis of microvascular diameter in imaging applications.
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Affiliation(s)
- Konnor P. McDowell
- Center for Developmental Biology and Regenerative Medicine, Seattle Children’s Research Institute, Seattle, WA, USA
| | - Andrée-Anne Berthiaume
- Center for Developmental Biology and Regenerative Medicine, Seattle Children’s Research Institute, Seattle, WA, USA
- Department of Neuroscience, Medical University of South Carolina, Charleston, SC, USA
| | - Taryn Tieu
- Center for Developmental Biology and Regenerative Medicine, Seattle Children’s Research Institute, Seattle, WA, USA
| | - David A. Hartmann
- Department of Neurology & Neurological Sciences, Stanford University School of Medicine, Stanford, CA, USA
| | - Andy Y. Shih
- Center for Developmental Biology and Regenerative Medicine, Seattle Children’s Research Institute, Seattle, WA, USA
- Department of Pediatrics, University of Washington, Seattle, WA, USA
- Department of Bioengineering, University of Washington, Seattle, WA, USA
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102
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Rolfes L, Riek-Burchardt M, Pawlitzki M, Minnerup J, Bock S, Schmidt M, Meuth SG, Gunzer M, Neumann J. Neutrophil granulocytes promote flow stagnation due to dynamic capillary stalls following experimental stroke. Brain Behav Immun 2021; 93:322-330. [PMID: 33486002 DOI: 10.1016/j.bbi.2021.01.011] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Revised: 01/08/2021] [Accepted: 01/11/2021] [Indexed: 12/01/2022] Open
Abstract
Flow stagnation of peri-ischemic capillaries due to dynamic leukocyte stalls has been described to be a contributor to ongoing penumbral injury in transient brain ischemia, but has not been investigated in permanent experimental stroke so far. Moreover, it is discussed that obstructing neutrophils are involved in this process; however, their contribution has not yet been proven. Here, we characterize the dynamics of neutrophil granulocytes in two models of permanent stroke (photothrombosis and permanent middle cerebral artery occlusion) using intravital two-photon fluorescence microscopy. Different to previous studies on LysM-eGFP+ cells we additionally apply a transgenic mouse model with tdTomato-expressing neutrophils to avoid interference from additional immune cell subsets. We identify repetitively occurring capillary stalls of varying duration promoted by neutrophils in both models of permanent cerebral ischemia, validating the suitability of our new transgenic mouse model in determining neutrophil occlusion formation in vivo. Flow cytometric analysis of peripheral blood (PB) and brain tissue from mice subjected to photothrombosis reveal an increase in the total proportion of neutrophils, with selective upregulation of endothelial adherence markers in the PB. In conclusion, the dynamic microcirculatory stall phenomenon that is described after transient ischemia followed by reperfusion also occurs after permanent small- or large-vessel stroke and is clearly attributable to neutrophils.
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Affiliation(s)
- Leoni Rolfes
- Department of Neurology with Institute of Translational Neurology, University Hospital Münster, Germany.
| | | | - Marc Pawlitzki
- Department of Neurology with Institute of Translational Neurology, University Hospital Münster, Germany; Department of Neurology, Otto-von-Guericke University, Magdeburg, Germany.
| | - Jens Minnerup
- Department of Neurology with Institute of Translational Neurology, University Hospital Münster, Germany.
| | - Stefanie Bock
- Department of Neurology with Institute of Translational Neurology, University Hospital Münster, Germany.
| | - Mariella Schmidt
- Department of Neurology with Institute of Translational Neurology, University Hospital Münster, Germany.
| | - Sven G Meuth
- Department of Neurology with Institute of Translational Neurology, University Hospital Münster, Germany; Department of Neurology, University Hospital Düsseldorf, Heinrich-Heine-University Düsseldorf, Germany.
| | - Matthias Gunzer
- Institute for Experimental Immunology and Imaging, University Hospital Essen, Germany.
| | - Jens Neumann
- Department of Neurology, Otto-von-Guericke University, Magdeburg, Germany.
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103
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Yasukagawa M, Shimada A, Shiozaki S, Tobita S, Yoshihara T. Phosphorescent Ir(III) complexes conjugated with oligoarginine peptides serve as optical probes for in vivo microvascular imaging. Sci Rep 2021; 11:4733. [PMID: 33637825 PMCID: PMC7910296 DOI: 10.1038/s41598-021-84115-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Accepted: 01/27/2021] [Indexed: 02/06/2023] Open
Abstract
Imaging the vascular structures of organ and tumor tissues is extremely important for assessing various pathological conditions. Herein we present the new vascular imaging probe BTQ-Rn (n = 8, 12, 16), a phosphorescent Ir(III) complex containing an oligoarginine peptide as a ligand. This microvasculature staining probe can be chemically synthesized, unlike the commonly used tomato lectins labeled with a fluorophore such as fluorescein isothiocyanate (FITC). Intravenous administration of BTQ-R12 to mice and subsequent confocal luminescence microscope measurements enabled in vivo vascular imaging of tumors and various organs, including kidney, liver and pancreas. Dual color imaging of hepatic tissues of living mice fed a high-fat diet using BTQ-R12 and the lipid droplet-specific probe PC6S revealed small and large lipid droplets in the hepatocytes, causing distortion of the sinusoidal structure. BTQ-R12 selectively stains vascular endothelium and thus allows longer-term vascular network imaging compared to fluorescent dextran with a molecular weight of 70 kDa that circulate in the bloodstream. Furthermore, time-gated measurements using this phosphorescent vascular probe enabled imaging of blood vessel structures without interference from autofluorescence.
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Affiliation(s)
- Mami Yasukagawa
- grid.256642.10000 0000 9269 4097Department of Chemistry and Chemical Biology, Graduate School of Science and Technology, Gunma University, 1-5-1 Tenjin-cho, Kiryu, Gunma 376-8515 Japan
| | - Aya Shimada
- grid.256642.10000 0000 9269 4097Department of Chemistry and Chemical Biology, Graduate School of Science and Technology, Gunma University, 1-5-1 Tenjin-cho, Kiryu, Gunma 376-8515 Japan
| | - Shuichi Shiozaki
- grid.256642.10000 0000 9269 4097Department of Chemistry and Chemical Biology, Graduate School of Science and Technology, Gunma University, 1-5-1 Tenjin-cho, Kiryu, Gunma 376-8515 Japan
| | - Seiji Tobita
- grid.256642.10000 0000 9269 4097Department of Chemistry and Chemical Biology, Graduate School of Science and Technology, Gunma University, 1-5-1 Tenjin-cho, Kiryu, Gunma 376-8515 Japan
| | - Toshitada Yoshihara
- grid.256642.10000 0000 9269 4097Department of Chemistry and Chemical Biology, Graduate School of Science and Technology, Gunma University, 1-5-1 Tenjin-cho, Kiryu, Gunma 376-8515 Japan
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104
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Hartung G, Badr S, Moeini M, Lesage F, Kleinfeld D, Alaraj A, Linninger A. Voxelized simulation of cerebral oxygen perfusion elucidates hypoxia in aged mouse cortex. PLoS Comput Biol 2021; 17:e1008584. [PMID: 33507970 PMCID: PMC7842915 DOI: 10.1371/journal.pcbi.1008584] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2020] [Accepted: 11/30/2020] [Indexed: 12/13/2022] Open
Abstract
Departures of normal blood flow and metabolite distribution from the cerebral microvasculature into neuronal tissue have been implicated with age-related neurodegeneration. Mathematical models informed by spatially and temporally distributed neuroimage data are becoming instrumental for reconstructing a coherent picture of normal and pathological oxygen delivery throughout the brain. Unfortunately, current mathematical models of cerebral blood flow and oxygen exchange become excessively large in size. They further suffer from boundary effects due to incomplete or physiologically inaccurate computational domains, numerical instabilities due to enormous length scale differences, and convergence problems associated with condition number deterioration at fine mesh resolutions. Our proposed simple finite volume discretization scheme for blood and oxygen microperfusion simulations does not require expensive mesh generation leading to the critical benefit that it drastically reduces matrix size and bandwidth of the coupled oxygen transfer problem. The compact problem formulation yields rapid and stable convergence. Moreover, boundary effects can effectively be suppressed by generating very large replica of the cortical microcirculation in silico using an image-based cerebrovascular network synthesis algorithm, so that boundaries of the perfusion simulations are far removed from the regions of interest. Massive simulations over sizeable portions of the cortex with feature resolution down to the micron scale become tractable with even modest computer resources. The feasibility and accuracy of the novel method is demonstrated and validated with in vivo oxygen perfusion data in cohorts of young and aged mice. Our oxygen exchange simulations quantify steep gradients near penetrating blood vessels and point towards pathological changes that might cause neurodegeneration in aged brains. This research aims to explain mechanistic interactions between anatomical structures and how they might change in diseases or with age. Rigorous quantification of age-related changes is of significant interest because it might aide in the search for imaging biomarkers for dementia and Alzheimer’s disease. Brain function critically depends on the maintenance of physiological blood supply and metabolism in the cortex. Disturbances to adequate perfusion have been linked to age-related neurodegeneration. However, the precise correlation between age-related hemodynamic changes and the resulting decline in oxygen delivery is not well understood and has not been quantified. Therefore, we introduce a new compact, and therefore highly scalable, computational method for predicting the physiological relationship between hemodynamics and cortical oxygen perfusion for large sections of the cortical microcirculation. We demonstrate the novel mesh generation-free (MGF), multi-scale simulation approach through realistic in vivo case studies of cortical microperfusion in the mouse brain. We further validate mechanistic correlations and a quantitative relationship between blood flow and brain oxygenation using experimental data from cohorts of young, middle aged and old mouse brains. Our computational approach overcomes size and performance limitations of previous unstructured meshing techniques to enable the prediction of oxygen tension with a spatial resolution of least two orders of magnitude higher than previously possible. Our simulation results support the hypothesis that structural changes in the microvasculature induce hypoxic pockets in the aged brain that are absent in the healthy, young mouse.
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Affiliation(s)
- Grant Hartung
- Department of Bioengineering, University of Illinois at Chicago, Chicago, Illinois, United States of America
| | - Shoale Badr
- Department of Bioengineering, University of Illinois at Chicago, Chicago, Illinois, United States of America
| | - Mohammad Moeini
- Polytechnique Montréal, Department of Electrical Engineering, Montreal, Canada
| | - Frédéric Lesage
- Polytechnique Montréal, Department of Electrical Engineering, Montreal, Canada
| | - David Kleinfeld
- Department of Physics, University of California San Diego, San Diego, California, United States of America
| | - Ali Alaraj
- Department of Neurosurgery, University of Illinois at Chicago, Chicago, Illinois, United States of America
| | - Andreas Linninger
- Department of Bioengineering, University of Illinois at Chicago, Chicago, Illinois, United States of America
- Department of Neurosurgery, University of Illinois at Chicago, Chicago, Illinois, United States of America
- * E-mail:
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105
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Underly RG, Shih AY. Rapid, Nitric Oxide Synthesis-Dependent Activation of MMP-9 at Pericyte Somata During Capillary Ischemia in vivo. Front Physiol 2021; 11:619230. [PMID: 33505320 PMCID: PMC7830159 DOI: 10.3389/fphys.2020.619230] [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: 10/19/2020] [Accepted: 12/10/2020] [Indexed: 11/28/2022] Open
Abstract
Nitric oxide serves essential roles in normal vascular physiology, but paradoxically contributes to vascular pathology in disease. During brain ischemia, aberrant nitric oxide levels can cause cellular injury through induction of nitrosative/oxidative stress and post-translational activation of matrix-metalloproteinase-9 (MMP-9). We recently demonstrated that brain pericyte somata were associated with very early and localized MMP-9 activation along capillaries during cerebral ischemia, leading to focal blood-brain barrier disruption. Here, we tested whether this effect was dependent upon nitric oxide production. In vivo two-photon imaging was used to directly visualize MMP9 activity using a FITC-gelatin probe and leakage of intravenous dye during photothrombotically induced capillary ischemia. Results showed that the NOS inhibitor, L-NIL, at concentrations affecting both iNOS and constitutive NOS isoforms, attenuated capillary leakage at pericyte soma-specific locations and substantially reduced FITC-gelatin cleavage. We also found that combined administration of L-NIL and anisomycin, an inhibitor of protein synthesis, led to near complete elimination of FITC-gelatin cleavage and vascular leakage. These results indicate that both nitric oxide synthase and new protein synthesis are involved in the rapid activation of MMP-9 at somata of capillary pericytes during ischemia.
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Affiliation(s)
- Robert G Underly
- Department of Neuroscience, Medical University of South Carolina, Charleston, SC, United States
| | - Andy Y Shih
- Department of Neuroscience, Medical University of South Carolina, Charleston, SC, United States.,Center for Developmental Biology and Regenerative Medicine, Seattle Children's Research Institute, Seattle, WA, United States.,Department of Pediatrics, University of Washington, Seattle, WA, United States.,Department of Bioengineering, University of Washington, Seattle, WA, United States
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106
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Network community structure and resilience to localized damage: Application to brain microcirculation. BRAIN MULTIPHYSICS 2021. [DOI: 10.1016/j.brain.2021.100028] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
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107
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Transcranial chronic optical access to longitudinally measure cerebral blood flow. J Neurosci Methods 2020; 350:109044. [PMID: 33340556 DOI: 10.1016/j.jneumeth.2020.109044] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2020] [Revised: 12/10/2020] [Accepted: 12/11/2020] [Indexed: 11/22/2022]
Abstract
BACKGROUND The regulation of cerebral blood flow is critical for normal brain functioning, and many physiological and pathological conditions can have long-term impacts on cerebral blood flow. However, minimally invasive tools to study chronic changes in animal models are limited. NEW METHOD We developed a minimally invasive surgical technique (cyanoacrylate skull, CAS) allowing us to image cerebral blood flow longitudinally through the intact mouse skull using laser speckle imaging. RESULTS With CAS we were able to detect acute changes in cerebral blood flow induced by hypercapnic challenge. We were also able to image cerebral blood flow dynamics with laser speckle imaging for over 100 days. Furthermore, the relative cerebral blood flow remained stable in mice from 30 days to greater than 100 days after the surgery. COMPARISON WITH EXISTING METHODS Previously, achieving continuous long-term optical access to measure cerebral blood flow in individual vessels in a mouse model involved invasive surgery. In contrast, the CAS technique presented here is relatively non-invasive, as it allows stable optical access through an intact mouse skull. CONCLUSIONS The CAS technique allows researcher to chronically measure cerebral blood flow dynamics for a significant portion of a mouse's lifespan. This approach may be useful for studying changes in blood flow due to cerebral pathology or for examining the therapeutic effects of modifying cerebral blood flow in mouse models relevant to human disease.
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108
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Imaging and optogenetic modulation of vascular mural cells in the live brain. Nat Protoc 2020; 16:472-496. [PMID: 33299155 DOI: 10.1038/s41596-020-00425-w] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Accepted: 09/24/2020] [Indexed: 12/17/2022]
Abstract
Mural cells (smooth muscle cells and pericytes) are integral components of brain blood vessels that play important roles in vascular formation, blood-brain barrier maintenance, and regulation of regional cerebral blood flow (rCBF). These cells are implicated in conditions ranging from developmental vascular disorders to age-related neurodegenerative diseases. Here we present complementary tools for cell labeling with transgenic mice and organic dyes that allow high-resolution intravital imaging of the different mural cell subtypes. We also provide detailed methodologies for imaging of spontaneous and neural activity-evoked calcium transients in mural cells. In addition, we describe strategies for single- and two-photon optogenetics that allow manipulation of the activity of individual and small clusters of mural cells. Together with measurements of diameter and flow in individual brain microvessels, calcium imaging and optogenetics allow the investigation of pericyte and smooth muscle cell physiology and their role in regulating rCBF. We also demonstrate the utility of these tools to investigate mural cells in the context of Alzheimer's disease and cerebral ischemia mouse models. Thus, these methods can be used to reveal the functional and structural heterogeneity of mural cells in vivo, and allow detailed cellular studies of the normal function and pathophysiology of mural cells in a variety of disease models. The implementation of this protocol can take from several hours to days depending on the intended applications.
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109
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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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110
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Fan JL, Rivera JA, Sun W, Peterson J, Haeberle H, Rubin S, Ji N. High-speed volumetric two-photon fluorescence imaging of neurovascular dynamics. Nat Commun 2020; 11:6020. [PMID: 33243995 PMCID: PMC7693336 DOI: 10.1038/s41467-020-19851-1] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2020] [Accepted: 10/13/2020] [Indexed: 02/02/2023] Open
Abstract
Understanding the structure and function of vasculature in the brain requires us to monitor distributed hemodynamics at high spatial and temporal resolution in three-dimensional (3D) volumes in vivo. Currently, a volumetric vasculature imaging method with sub-capillary spatial resolution and blood flow-resolving speed is lacking. Here, using two-photon laser scanning microscopy (TPLSM) with an axially extended Bessel focus, we capture volumetric hemodynamics in the awake mouse brain at a spatiotemporal resolution sufficient for measuring capillary size and blood flow. With Bessel TPLSM, the fluorescence signal of a vessel becomes proportional to its size, which enables convenient intensity-based analysis of vessel dilation and constriction dynamics in large volumes. We observe entrainment of vasodilation and vasoconstriction with pupil diameter and measure 3D blood flow at 99 volumes/second. Demonstrating high-throughput monitoring of hemodynamics in the awake brain, we expect Bessel TPLSM to make broad impacts on neurovasculature research.
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Affiliation(s)
- Jiang Lan Fan
- University of California, Berkeley, CA, USA.,University of California, San Francisco, CA, USA
| | - Jose A Rivera
- Department of Physics, University of California, Berkeley, CA, USA
| | - Wei Sun
- Thorlabs Imaging Systems, Sterling, VA, USA
| | | | | | - Sam Rubin
- Thorlabs Imaging Systems, Sterling, VA, USA.,LightPath Technologies Inc., Orlando, FL, USA
| | - Na Ji
- Department of Physics, University of California, Berkeley, CA, USA. .,Department of Molecular and Cell Biology, University of California, Berkeley, CA, USA. .,Helen Wills Neuroscience Institute, University of California, Berkeley, CA, USA. .,Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA.
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111
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Validation of red blood cell flux and velocity estimations based on optical coherence tomography intensity fluctuations. Sci Rep 2020; 10:19584. [PMID: 33177606 PMCID: PMC7658245 DOI: 10.1038/s41598-020-76774-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2020] [Accepted: 11/02/2020] [Indexed: 01/03/2023] Open
Abstract
We present a validation of red blood cell flux and speed measurements based on the passage of erythrocytes through the OCT’s focal volume. We compare the performance of the so-called RBC-passage OCT technique to co-localized and simultaneously acquired two-photon excitation fluorescence microscopy (TPEF) measurements. Using concurrent multi-modal imaging, we show that fluctuations in the OCT signal display highly similar features to TPEF time traces. Furthermore, we demonstrate an overall difference in RBC flux and speed of 2.5 ± 3.27 RBC/s and 0.12 ± 0.67 mm/s (mean ± S.D.), compared to TPEF. The analysis also revealed that the OCT RBC flux estimation is most accurate between 20 RBC/s to 60 RBC/s, and is severely underestimated at fluxes beyond 80 RBC/s. Lastly, our analysis shows that the RBC speed estimations increase in accuracy as the speed decreases, reaching a difference of 0.16 ± 0.25 mm/s within the 0–0.5 mm/s speed range.
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112
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Turner KL, Gheres KW, Proctor EA, Drew PJ. Neurovascular coupling and bilateral connectivity during NREM and REM sleep. eLife 2020; 9:62071. [PMID: 33118932 PMCID: PMC7758068 DOI: 10.7554/elife.62071] [Citation(s) in RCA: 48] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Accepted: 10/28/2020] [Indexed: 12/11/2022] Open
Abstract
To understand how arousal state impacts cerebral hemodynamics and neurovascular coupling, we monitored neural activity, behavior, and hemodynamic signals in un-anesthetized, head-fixed mice. Mice frequently fell asleep during imaging, and these sleep events were interspersed with periods of wake. During both NREM and REM sleep, mice showed large increases in cerebral blood volume ([HbT]) and arteriole diameter relative to the awake state, two to five times larger than those evoked by sensory stimulation. During NREM, the amplitude of bilateral low-frequency oscillations in [HbT] increased markedly, and coherency between neural activity and hemodynamic signals was higher than the awake resting and REM states. Bilateral correlations in neural activity and [HbT] were highest during NREM, and lowest in the awake state. Hemodynamic signals in the cortex are strongly modulated by arousal state, and changes during sleep are substantially larger than sensory-evoked responses.
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Affiliation(s)
- Kevin L Turner
- Department of Biomedical Engineering, The Pennsylvania State University, University Park, United States.,Center for Neural Engineering, The Pennsylvania State University, University Park, United States
| | - Kyle W Gheres
- Center for Neural Engineering, The Pennsylvania State University, University Park, United States.,Graduate Program in Molecular, Cellular, and Integrative Biosciences, The Pennsylvania State University, University Park, United States
| | - Elizabeth A Proctor
- Department of Biomedical Engineering, The Pennsylvania State University, University Park, United States.,Center for Neural Engineering, The Pennsylvania State University, University Park, United States.,Department of Engineering Science and Mechanics, The Pennsylvania State University, University Park, United States.,Department of Neurosurgery, Penn State College of Medicine, Hershey, United States.,Department of Pharmacology, Penn State College of Medicine, Hershey, United States
| | - Patrick J Drew
- Department of Biomedical Engineering, The Pennsylvania State University, University Park, United States.,Center for Neural Engineering, The Pennsylvania State University, University Park, United States.,Department of Engineering Science and Mechanics, The Pennsylvania State University, University Park, United States.,Department of Neurosurgery, Penn State College of Medicine, Hershey, United States
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113
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Marques Neto SR, Castiglione RC, da Silva TCB, Paes LDS, Pontes A, Oliveira DF, Ferraz EB, Ade Caldas CC, Nascimento JHM, Bouskela E. Effects of high intensity interval training on neuro-cardiovascular dynamic changes and mitochondrial dysfunction induced by high-fat diet in rats. PLoS One 2020; 15:e0240060. [PMID: 33095799 PMCID: PMC7584217 DOI: 10.1371/journal.pone.0240060] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Accepted: 09/18/2020] [Indexed: 11/24/2022] Open
Abstract
BACKGROUND AND AIMS Mitochondrial swelling is involved in the pathogenesis of many human diseases associated with oxidative stress including obesity. One of the strategies for prevention of deleterious effects related to obesity and overweight is engaging in regular physical activity, of which high intensity interval training (HIIT) is efficient in promoting biogenesis and improving the function of mitochondria. Therefore, our aims were to investigate the effects of HIIT on metabolic and neuro-cardiovascular dynamic control and mitochondrial swelling induced by high-fat diet (HFD). METHODS AND RESULTS Twenty-three male Wistar rats (60 - 80g) were divided into 4 subgroups: control (C), HIIT, HFD and HFD+HIIT. The whole experimentation period lasted for 22 weeks and HIIT sessions were performed 5 days a week during the last 4 weeks. At the end of the experiments, fasting glucose and insulin tolerance tests were performed. Cerebral microcirculation was analyzed using cortical intravital microscopy for capillary diameter and functional density. Cardiac function and ergoespirometric parameters were also investigated. Mitochondrial swelling was evaluated on brain and heart extracts. HFD promoted an increase on body adiposity (p<0.001), fasting glucose levels (p<0.001), insulin resistance index (p<0.05), cardiac hypertrophy index (p<0.05) and diastolic blood pressure (p<0.05), along with worsened cardiac function (p<0.05), reduced functional cerebral capillary density (p<0.05) and its diameter (p<0.01), and heart and brain mitochondrial function (p<0.001). HFD did not affect any ergoespirometric parameter. After 4 weeks of training, HIIT was able to improve cardiac hypertrophy index, diastolic blood pressure, cerebral functional capillary density (p<0.01) and heart and brain mitochondrial swelling (p<0.001). CONCLUSION In animals subjected to HFD, HIIT ameliorated both cerebral mitochondrial swelling and functional capillary density, but it did not improve cardiovascular function suggesting that the cardiovascular dysfunction elicited by HFD was not due to heart mitochondrial swelling.
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Affiliation(s)
- Silvio R. Marques Neto
- Laboratory for Clinical and Experimental Research on Vascular Biology (BioVasc), Biomedical Center, State University of Rio de Janeiro, Rio de Janeiro, RJ, Brazil
- Physical Activity Sciences Laboratory (LACAF), Physical Activity Sciences Postgraduate Program, Salgado de Oliveira University (UNIVERSO), Niteroi, RJ, Brazil
- Exercise Physiology Laboratory, School of Physical Education, Estácio de Sá University, Rio de Janeiro, RJ, Brazil
- Health Science School, Universidade do Grande Rio, Duque de Caxias, RJ, Brazil
| | - Raquel C. Castiglione
- Laboratory for Clinical and Experimental Research on Vascular Biology (BioVasc), Biomedical Center, State University of Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| | - Teresa C. B. da Silva
- Laboratory for Clinical and Experimental Research on Vascular Biology (BioVasc), Biomedical Center, State University of Rio de Janeiro, Rio de Janeiro, RJ, Brazil
- Health Science School, Universidade do Grande Rio, Duque de Caxias, RJ, Brazil
| | - Lorena da S. Paes
- Laboratory for Clinical and Experimental Research on Vascular Biology (BioVasc), Biomedical Center, State University of Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| | - Aiza Pontes
- Laboratory for Clinical and Experimental Research on Vascular Biology (BioVasc), Biomedical Center, State University of Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| | - Dahienne F. Oliveira
- Cardiac Electrophysiology Laboratory, Carlos Chagas Filho Institute of Biophysics, Federal University of Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| | - Emanuelle B. Ferraz
- Cardiac Electrophysiology Laboratory, Carlos Chagas Filho Institute of Biophysics, Federal University of Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| | - Carla Christina Ade Caldas
- Physical Activity Sciences Laboratory (LACAF), Physical Activity Sciences Postgraduate Program, Salgado de Oliveira University (UNIVERSO), Niteroi, RJ, Brazil
| | - José Hamilton M. Nascimento
- Cardiac Electrophysiology Laboratory, Carlos Chagas Filho Institute of Biophysics, Federal University of Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| | - Eliete Bouskela
- Laboratory for Clinical and Experimental Research on Vascular Biology (BioVasc), Biomedical Center, State University of Rio de Janeiro, Rio de Janeiro, RJ, Brazil
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Takahashi T, Zhang H, Kawakami R, Yarinome K, Agetsuma M, Nabekura J, Otomo K, Okamura Y, Nemoto T. PEO-CYTOP Fluoropolymer Nanosheets as a Novel Open-Skull Window for Imaging of the Living Mouse Brain. iScience 2020; 23:101579. [PMID: 33083745 PMCID: PMC7554658 DOI: 10.1016/j.isci.2020.101579] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Revised: 08/20/2020] [Accepted: 09/15/2020] [Indexed: 01/30/2023] Open
Abstract
In vivo two-photon deep imaging with a broad field of view has revealed functional connectivity among brain regions. Here, we developed a novel observation method that utilizes a polyethylene-oxide-coated CYTOP (PEO-CYTOP) nanosheet with a thickness of ∼130 nm that exhibited a water retention effect and a hydrophilized adhesive surface. PEO-CYTOP nanosheets firmly adhered to brain surfaces, which suppressed bleeding from superficial veins. By taking advantage of the excellent optical properties of PEO-CYTOP nanosheets, we performed in vivo deep imaging in mouse brains at high resolution. Moreover, PEO-CYTOP nanosheets enabled to prepare large cranial windows, achieving in vivo imaging of neural structure and Ca2+ elevation in a large field of view. Furthermore, the PEO-CYTOP nanosheets functioned as a sealing material, even after the removal of the dura. These results indicate that this method would be suitable for the investigation of neural functions that are composed of interactions among multiple regions. PEO-CYTOP nanosheet enables in vivo deep brain imaging in a vast field of view The 130 nm thickness and the hydrophilized surface realize the strong adhesiveness Suppressions of bleeding from the surface and inflammation in long-term are achieved The vast and transparent cranial window with natural curvature of the surface
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Affiliation(s)
- Taiga Takahashi
- Biophotonics Research Group, Exploratory Research Center on Life and Living Systems (ExCELLS), National Institutes of Natural Sciences, Higashiyama 5-1, Myodaiji, Okazaki, Aichi 444-8787, Japan.,Division of Biophotonics, National Institute for Physiological Sciences, National Institutes of Natural Sciences, Higashiyama 5-1, Myodaiji, Okazaki, Aichi 444-8787, Japan.,School of Life Science, The Graduate University for Advanced Studies (SOKENDAI), Higashiyama 5-1, Myodaiji, Okazaki, Aichi 444-8787, Japan.,Research Institute for Electronic Science, Hokkaido University, Hokkaido, Kita 20 Nishi 10, Kita-ku, Sapporo, Hokkaido 001-0020, Japan.,Graduate School of Information Science and Technology Hokkaido University, Hokkaido, Kita 20 Nishi 10, Kita-ku, Sapporo, Hokkaido 001-0020, Japan
| | - Hong Zhang
- Department of Applied Chemistry, School of Engineering, Tokai University, 4-1-1 Kitakaname, Hiratsuka, Kanagawa 259-1292, Japan.,Micro/Nano Technology Center, Tokai University, 4-1-1 Kitakaname, Hiratsuka, Kanagawa 259-1292, Japan
| | - Ryosuke Kawakami
- Research Institute for Electronic Science, Hokkaido University, Hokkaido, Kita 20 Nishi 10, Kita-ku, Sapporo, Hokkaido 001-0020, Japan.,Graduate School of Information Science and Technology Hokkaido University, Hokkaido, Kita 20 Nishi 10, Kita-ku, Sapporo, Hokkaido 001-0020, Japan.,Department of Molecular Medicine for Pathogenesis, Graduate School of Medicine Ehime University, Shitsukawa 454, Toon, Ehime 791-0295, Japan
| | - Kenji Yarinome
- Course of Applied Science, Graduate School of Engineering, Tokai University, 4-1-1 Kitakaname, Hiratsuka, Kanagawa 259-1292, Japan
| | - Masakazu Agetsuma
- Division of Homeostatic Development, National Institute for Physiological Sciences, National Institutes of Natural Sciences, Okazaki, 444-8585, Japan
| | - Junichi Nabekura
- School of Life Science, The Graduate University for Advanced Studies (SOKENDAI), Higashiyama 5-1, Myodaiji, Okazaki, Aichi 444-8787, Japan.,Division of Homeostatic Development, National Institute for Physiological Sciences, National Institutes of Natural Sciences, Okazaki, 444-8585, Japan
| | - Kohei Otomo
- Biophotonics Research Group, Exploratory Research Center on Life and Living Systems (ExCELLS), National Institutes of Natural Sciences, Higashiyama 5-1, Myodaiji, Okazaki, Aichi 444-8787, Japan.,Division of Biophotonics, National Institute for Physiological Sciences, National Institutes of Natural Sciences, Higashiyama 5-1, Myodaiji, Okazaki, Aichi 444-8787, Japan.,School of Life Science, The Graduate University for Advanced Studies (SOKENDAI), Higashiyama 5-1, Myodaiji, Okazaki, Aichi 444-8787, Japan.,Research Institute for Electronic Science, Hokkaido University, Hokkaido, Kita 20 Nishi 10, Kita-ku, Sapporo, Hokkaido 001-0020, Japan.,Graduate School of Information Science and Technology Hokkaido University, Hokkaido, Kita 20 Nishi 10, Kita-ku, Sapporo, Hokkaido 001-0020, Japan
| | - Yosuke Okamura
- Department of Applied Chemistry, School of Engineering, Tokai University, 4-1-1 Kitakaname, Hiratsuka, Kanagawa 259-1292, Japan.,Micro/Nano Technology Center, Tokai University, 4-1-1 Kitakaname, Hiratsuka, Kanagawa 259-1292, Japan.,Course of Applied Science, Graduate School of Engineering, Tokai University, 4-1-1 Kitakaname, Hiratsuka, Kanagawa 259-1292, Japan
| | - Tomomi Nemoto
- Biophotonics Research Group, Exploratory Research Center on Life and Living Systems (ExCELLS), National Institutes of Natural Sciences, Higashiyama 5-1, Myodaiji, Okazaki, Aichi 444-8787, Japan.,Division of Biophotonics, National Institute for Physiological Sciences, National Institutes of Natural Sciences, Higashiyama 5-1, Myodaiji, Okazaki, Aichi 444-8787, Japan.,School of Life Science, The Graduate University for Advanced Studies (SOKENDAI), Higashiyama 5-1, Myodaiji, Okazaki, Aichi 444-8787, Japan.,Research Institute for Electronic Science, Hokkaido University, Hokkaido, Kita 20 Nishi 10, Kita-ku, Sapporo, Hokkaido 001-0020, Japan.,Graduate School of Information Science and Technology Hokkaido University, Hokkaido, Kita 20 Nishi 10, Kita-ku, Sapporo, Hokkaido 001-0020, Japan
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115
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Xiong J, Wang W, Wang C, Zhong C, Ruan R, Mao Z, Liu Z. Visualizing Peroxynitrite in Microvessels of the Brain with Stroke Using an Engineered Highly Specific Fluorescent Probe. ACS Sens 2020; 5:3237-3245. [PMID: 33092345 DOI: 10.1021/acssensors.0c01555] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Stroke is one of the leading causes of death and disability in the world, which is associated with malfunction of reactive oxygen species and reactive nitrogen species (ROS/RNS) in cerebral microvessels. In vivo monitoring these species, such as ONOO-, with high selectivity in stroke process is of great significance for early diagnoses and therapies of the disease. Herein, by engineering an indoline-2,3-dione moiety as the recognizing domain, we proposed a novel fluorescence probe Rd-PN2 with highly specific response toward ONOO-, even in the coexistence of other ROS/RNS with high concentration. Rd-PN2 showed high sensitivity and reaction speed in response to ONOO- and exhibited satisfying performances in tracking the endogenously generated ONOO- in living cells and zebrafish. Accordingly, Rd-PN2 can furnish real-time and in vivo visualizing of ONOO- in cerebral microvessels of mice with ischemic and hemorrhagic strokes under two-photon microscopy. This work presented a precisely modulated fluorescence probe for real-time visualizing of ONOO- production in cerebral micovessels, which will also help to acquire more accurate information in the studies of ONOO- functions in the future.
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Affiliation(s)
- Jianhua Xiong
- Hubei Collaborative Innovation Center for Advanced Organic Chemical Materials & Ministry of Education Key Laboratory for the Synthesis and Application of Organic Functional Molecules, College of Chemistry and Chemical Engineering, Hubei University, Wuhan 430062, China
| | - Weiwei Wang
- Hubei Collaborative Innovation Center for Advanced Organic Chemical Materials & Ministry of Education Key Laboratory for the Synthesis and Application of Organic Functional Molecules, College of Chemistry and Chemical Engineering, Hubei University, Wuhan 430062, China
| | - Caixia Wang
- Hubei Collaborative Innovation Center for Advanced Organic Chemical Materials & Ministry of Education Key Laboratory for the Synthesis and Application of Organic Functional Molecules, College of Chemistry and Chemical Engineering, Hubei University, Wuhan 430062, China
| | - Cheng Zhong
- Hubei Key Laboratory on Organic and Polymeric Optoelectronic Materials, College of Chemistry and Molecular Sciences, Wuhan University, Wuhan, Hubei 430072, China
| | - Renqiang Ruan
- Hubei Collaborative Innovation Center for Advanced Organic Chemical Materials & Ministry of Education Key Laboratory for the Synthesis and Application of Organic Functional Molecules, College of Chemistry and Chemical Engineering, Hubei University, Wuhan 430062, China
| | - Zhiqiang Mao
- Hubei Collaborative Innovation Center for Advanced Organic Chemical Materials & Ministry of Education Key Laboratory for the Synthesis and Application of Organic Functional Molecules, College of Chemistry and Chemical Engineering, Hubei University, Wuhan 430062, China
| | - Zhihong Liu
- Hubei Collaborative Innovation Center for Advanced Organic Chemical Materials & Ministry of Education Key Laboratory for the Synthesis and Application of Organic Functional Molecules, College of Chemistry and Chemical Engineering, Hubei University, Wuhan 430062, China
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116
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Echagarruga CT, Gheres KW, Norwood JN, Drew PJ. nNOS-expressing interneurons control basal and behaviorally evoked arterial dilation in somatosensory cortex of mice. eLife 2020; 9:e60533. [PMID: 33016877 PMCID: PMC7556878 DOI: 10.7554/elife.60533] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Accepted: 10/02/2020] [Indexed: 12/19/2022] Open
Abstract
Cortical neural activity is coupled to local arterial diameter and blood flow. However, which neurons control the dynamics of cerebral arteries is not well understood. We dissected the cellular mechanisms controlling the basal diameter and evoked dilation in cortical arteries in awake, head-fixed mice. Locomotion drove robust arterial dilation, increases in gamma band power in the local field potential (LFP), and increases calcium signals in pyramidal and neuronal nitric oxide synthase (nNOS)-expressing neurons. Chemogenetic or pharmocological modulation of overall neural activity up or down caused corresponding increases or decreases in basal arterial diameter. Modulation of pyramidal neuron activity alone had little effect on basal or evoked arterial dilation, despite pronounced changes in the LFP. Modulation of the activity of nNOS-expressing neurons drove changes in the basal and evoked arterial diameter without corresponding changes in population neural activity.
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Affiliation(s)
| | - Kyle W Gheres
- Molecular, Cellular, and Integrative Biology Graduate Program, Pennsylvania State UniversityUniversity ParkUnited States
| | - Jordan N Norwood
- Cell and Developmental Biology Graduate Program, Pennsylvania State UniversityUniversity ParkUnited States
| | - Patrick J Drew
- Bioengineering Graduate Program, Pennsylvania State UniversityUniversity ParkUnited States
- Molecular, Cellular, and Integrative Biology Graduate Program, Pennsylvania State UniversityUniversity ParkUnited States
- Cell and Developmental Biology Graduate Program, Pennsylvania State UniversityUniversity ParkUnited States
- Departments of Engineering Science and Mechanics, Biomedical Engineering, and Neurosurgery, Pennsylvania State UniversityUniversity ParkUnited States
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117
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He Y, Wang M, Yu X. High spatiotemporal vessel-specific hemodynamic mapping with multi-echo single-vessel fMRI. J Cereb Blood Flow Metab 2020; 40:2098-2114. [PMID: 31696765 PMCID: PMC7786852 DOI: 10.1177/0271678x19886240] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
High-resolution fMRI enables noninvasive mapping of the hemodynamic responses from individual penetrating vessels in animal brains. Here, a 2D multi-echo single-vessel fMRI (MESV-fMRI) method has been developed to map the fMRI signal from arterioles and venules with a 100 ms sampling rate at multiple echo times (TE, 3-30 ms) and short acquisition windows (<1 ms). The T2*-weighted signal shows the increased extravascular effect on venule voxels as a function of TE. In contrast, the arteriole voxels show an increased fMRI signal with earlier onset than venules voxels at the short TE (3 ms) with increased blood inflow and volume effects. MESV-fMRI enables vessel-specific T2* mapping and presents T2*-based fMRI time courses with higher contrast-to-noise ratios (CNRs) than the T2*-weighted fMRI signal at a given TE. The vessel-specific T2* mapping also allows semi-quantitative estimation of the oxygen saturation levels (Y) and their changes (ΔY) at a given blood volume fraction upon neuronal activation. The MESV-fMRI method enables vessel-specific T2* measurements with high spatiotemporal resolution for better modeling of the fMRI signal based on the hemodynamic parameters.
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Affiliation(s)
- Yi He
- Translational Neuroimaging and Neural Control Group, High Field Magnetic Resonance Department, Max Planck Institute for Biological Cybernetics, Tuebingen, Germany.,Graduate Training Centre of Neuroscience, International Max Planck Research School, University of Tuebingen, Tuebingen, Germany.,Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Hvidovre, Hvidovre, Denmark
| | - Maosen Wang
- Translational Neuroimaging and Neural Control Group, High Field Magnetic Resonance Department, Max Planck Institute for Biological Cybernetics, Tuebingen, Germany.,Graduate Training Centre of Neuroscience, International Max Planck Research School, University of Tuebingen, Tuebingen, Germany
| | - Xin Yu
- Translational Neuroimaging and Neural Control Group, High Field Magnetic Resonance Department, Max Planck Institute for Biological Cybernetics, Tuebingen, Germany.,Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA
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118
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Medin aggregation causes cerebrovascular dysfunction in aging wild-type mice. Proc Natl Acad Sci U S A 2020; 117:23925-23931. [PMID: 32900929 DOI: 10.1073/pnas.2011133117] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Medin is the most common amyloid known in humans, as it can be found in blood vessels of the upper body in virtually everybody over 50 years of age. However, it remains unknown whether deposition of Medin plays a causal role in age-related vascular dysfunction. We now report that aggregates of Medin also develop in the aorta and brain vasculature of wild-type mice in an age-dependent manner. Strikingly, genetic deficiency of the Medin precursor protein, MFG-E8, eliminates not only vascular aggregates but also prevents age-associated decline of cerebrovascular function in mice. Given the prevalence of Medin aggregates in the general population and its role in vascular dysfunction with aging, targeting Medin may become a novel approach to sustain healthy aging.
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119
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Regeneration of the neurogliovascular unit visualized in vivo by transcranial live-cell imaging. J Neurosci Methods 2020; 343:108808. [DOI: 10.1016/j.jneumeth.2020.108808] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2020] [Revised: 06/02/2020] [Accepted: 06/11/2020] [Indexed: 12/15/2022]
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120
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Kedarasetti RT, Turner KL, Echagarruga C, Gluckman BJ, Drew PJ, Costanzo F. Functional hyperemia drives fluid exchange in the paravascular space. Fluids Barriers CNS 2020; 17:52. [PMID: 32819402 PMCID: PMC7441569 DOI: 10.1186/s12987-020-00214-3] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Accepted: 08/09/2020] [Indexed: 12/20/2022] Open
Abstract
The brain lacks a conventional lymphatic system to remove metabolic waste. It has been proposed that directional fluid movement through the arteriolar paravascular space (PVS) promotes metabolite clearance. We performed simulations to examine if arteriolar pulsations and dilations can drive directional CSF flow in the PVS and found that arteriolar wall movements do not drive directional CSF flow. We propose an alternative method of metabolite clearance from the PVS, namely fluid exchange between the PVS and the subarachnoid space (SAS). In simulations with compliant brain tissue, arteriolar pulsations did not drive appreciable fluid exchange between the PVS and the SAS. However, when the arteriole dilated, as seen during functional hyperemia, there was a marked exchange of fluid. Simulations suggest that functional hyperemia may serve to increase metabolite clearance from the PVS. We measured blood vessels and brain tissue displacement simultaneously in awake, head-fixed mice using two-photon microscopy. These measurements showed that brain deforms in response to pressure changes in PVS, consistent with our simulations. Our results show that the deformability of the brain tissue needs to be accounted for when studying fluid flow and metabolite transport.
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Affiliation(s)
- Ravi Teja Kedarasetti
- Center for Neural Engineering, The Pennsylvania State University, University Park, PA, USA
- Department of Engineering Science and Mechanics, The Pennsylvania State University, University Park, PA, USA
| | - Kevin L Turner
- Center for Neural Engineering, The Pennsylvania State University, University Park, PA, USA
- Department of Biomedical Engineering, The Pennsylvania State University, University Park, PA, USA
| | - Christina Echagarruga
- Center for Neural Engineering, The Pennsylvania State University, University Park, PA, USA
- Department of Biomedical Engineering, The Pennsylvania State University, University Park, PA, USA
| | - Bruce J Gluckman
- Center for Neural Engineering, The Pennsylvania State University, University Park, PA, USA
- Department of Engineering Science and Mechanics, The Pennsylvania State University, University Park, PA, USA
- Department of Neurosurgery, The Pennsylvania State University, University Park, PA, USA
- Department of Biomedical Engineering, The Pennsylvania State University, University Park, PA, USA
| | - Patrick J Drew
- Center for Neural Engineering, The Pennsylvania State University, University Park, PA, USA.
- Department of Engineering Science and Mechanics, The Pennsylvania State University, University Park, PA, USA.
- Department of Neurosurgery, The Pennsylvania State University, University Park, PA, USA.
- Department of Biomedical Engineering, The Pennsylvania State University, University Park, PA, USA.
| | - Francesco Costanzo
- Center for Neural Engineering, The Pennsylvania State University, University Park, PA, USA.
- Department of Engineering Science and Mechanics, The Pennsylvania State University, University Park, PA, USA.
- Department of Biomedical Engineering, The Pennsylvania State University, University Park, PA, USA.
- Department of Mathematics, The Pennsylvania State University, University Park, PA, USA.
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121
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Non-invasive in-vivo 3-D imaging of small animals using spatially filtered enhanced truncated-correlation photothermal coherence tomography. Sci Rep 2020; 10:13743. [PMID: 32792647 PMCID: PMC7426848 DOI: 10.1038/s41598-020-70815-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2019] [Accepted: 06/30/2020] [Indexed: 11/08/2022] Open
Abstract
We present enhanced truncated-correlation phototothermal coherence tomography (eTC-PCT) for non-invasive three-dimensional imaging of small animals. Tumor detection is reported in a mouse thigh by injecting cancerous cells in the thigh followed by eTC-PCT imaging. Detection of the tumor 3 days after injection may lead to potential for using the eTC-PCT method for cancer treatment studies. eTC-PCT was also applied successfully to non-invasive in-vivo mouse brain structural imaging. A unique spatial-gradient-gate adaptive filter was introduced in a scanned mode along the (x,y) coordinates of camera images from different sub-cranial depths, revealing absorber true spatial extent from diffusive photothermal images and restoring pre-diffusion lateral image resolution beyond the Rayleigh criterion limit in diffusion-wave imaging science. The spatial resolution and contrast enhancement demonstrated in photothermal in-vivo and ex-vivo images of the mouse brain revealed not only vascular structures but also other brain structures, such as the brain hemispheres, cerebellum, and olfactory lobes.
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122
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Fu X, Sompol P, Brandon JA, Norris CM, Wilkop T, Johnson LA, Richards CI. In Vivo Single-Molecule Detection of Nanoparticles for Multiphoton Fluorescence Correlation Spectroscopy to Quantify Cerebral Blood Flow. NANO LETTERS 2020; 20:6135-6141. [PMID: 32628854 PMCID: PMC8405275 DOI: 10.1021/acs.nanolett.0c02280] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
We present the application of multiphoton in vivo fluorescence correlation spectroscopy (FCS) of fluorescent nanoparticles for the measurement of cerebral blood flow with excellent spatial and temporal resolution. Through the detection of single nanoparticles within the complex vessel architecture of a live mouse, this new approach enables the quantification of nanoparticle dynamics occurring within the vasculature along with simultaneous measurements of blood flow properties in the brain. In addition to providing high resolution blood flow measurements, this approach enables real-time quantification of nanoparticle concentration, degradation, and transport. This method is capable of quantifying flow rates at each pixel with submicron resolution to enable monitoring of dynamic changes in flow rates in response to changes in the animal's physiological condition. Scanning the excitation beam using FCS provides pixel by pixel mapping of flow rates with subvessel resolution across capillaries 300 μm deep in the brains of mice.
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Affiliation(s)
- Xu Fu
- Department of Chemistry, University of Kentucky, Lexington, Kentucky 40506, United States
| | - Pradoldej Sompol
- Sanders-Brown Center on Aging, University of Kentucky, Lexington, Kentucky 40536, United States
| | - Jason A Brandon
- Department of Physiology, University of Kentucky, Lexington, Kentucky 40536, United States
| | - Christopher M Norris
- Sanders-Brown Center on Aging, University of Kentucky, Lexington, Kentucky 40536, United States
| | - Thomas Wilkop
- Light Microscopy Core, University of Kentucky, Lexington, Kentucky 40536, United States
| | - Lance A Johnson
- Sanders-Brown Center on Aging, University of Kentucky, Lexington, Kentucky 40536, United States
- Department of Physiology, University of Kentucky, Lexington, Kentucky 40536, United States
| | - Christopher I Richards
- Department of Chemistry, University of Kentucky, Lexington, Kentucky 40506, United States
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123
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Wang Y, Liang G, Liu F, Chen Q, Xi L. A Long-Term Cranial Window for High-Resolution Photoacoustic Imaging. IEEE Trans Biomed Eng 2020; 68:706-711. [PMID: 32746074 DOI: 10.1109/tbme.2020.3012663] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
OBJECTIVE In this study, we introduce the design, fabrication, and assessment of an optically and acoustically transparent, long-term and biocompatible cranial window for high-resolution photoacoustic microscopy of rat cerebral cortex. METHODS The cranial window is fabricated with a polydimethylsiloxane (PDMS) layer bonded with a glass ring (outer diameter: 8 mm, inner diameter: 5 mm) via air plasma cleaning. A detailed comparison of image quality was performed with the implantation of cranial windows using different thicknesses of the PDMS film, and the cover glass. In addition, long-term in vivo monitoring of rat cerebral cortex was conducted to evaluate the stability of the cranial window. Furthermore, we successfully applied this window for longitudinal photoacoustic imaging in freely moving rats. RESULTS Based on a detailed evaluation, the cranial window fabricated with PDMS has a better imaging quality compared with a conventional cover-glass-based cranial window. The optimal film thickness is 50 μm considering the elastic deforming capability of PDMS. The cranial window maintained good quality for 21 and 12 days in anesthetized and free moving rats, respectively. CONCLUSION The cranial window has a good imaging quality for both anesthetized and behaving rats, enabling long-term, high-resolution, and steady photoacoustic imaging of cerebral vasculatures. SIGNIFICANCE Based on the studies of both anesthetized and behaving rats, the proposed cranial window has the potential to be used in the longitudinal in vivo study of chronic brain diseases in freely moving rodents.
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124
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Portörő I, Mukli P, Kocsis L, Hermán P, Caccia D, Perrella M, Mozzarelli A, Ronda L, Mathe D, Eke A. Model-based evaluation of the microhemodynamic effects of PEGylated HBOC molecules in the rat brain cortex: a laser speckle imaging study. BIOMEDICAL OPTICS EXPRESS 2020; 11:4150-4175. [PMID: 32923034 PMCID: PMC7449705 DOI: 10.1364/boe.388089] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/2020] [Revised: 04/24/2020] [Accepted: 05/04/2020] [Indexed: 06/11/2023]
Abstract
Hemoglobin-based oxygen carriers (HBOCs) were developed with the aim of substituting transfusions in emergency events. However, they exhibit adverse events, such as nitric oxide (NO) scavenging, vasoactivity, enhanced platelet aggregation, presently hampering their clinical application. The impact of two prototypical PEGylated HBOCs, Euro-PEG-Hb and PEG-HbO2, endowed by different oxygen affinities and hydrodynamic volumes, was assessed on the cerebrocortical parenchymal microhemodynamics, and extravasation through the blood-brain-barrier (BBB) by laser speckle contrast imaging (LSCI) method and near-infrared (NIR) imaging, respectively. By evaluating voxel-wise cerebrocortical red blood cell velocity, non-invasively for its mean kernel-wise value ( v ¯ RBC ), and model-derived kernel-wise predictions for microregional tissue hematocrit, THt, and fractional change in hematocrit-corrected vascular resistance, R', as measures of potential adverse effects (enhanced platelet aggregation and vasoactivity, respectively) we found i) no significant difference between tested HBOCs in the systemic and microregional parameters, and in the relative spatial dispersion of THt, and R' as additional measures of HBOC-related adverse effects, and ii) no extravasation through BBB by Euro-PEG-Hb. We conclude that Euro-PEG-Hb does not exhibit adverse effects in the brain microcirculation that could be directly attributed to NO scavenging.
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Affiliation(s)
- István Portörő
- Institute of Translational Medicine, Semmelweis University, Hungary
- These authors contributed equally to this work
| | - Péter Mukli
- Institute of Translational Medicine, Semmelweis University, Hungary
- Department of Physiology, Semmelweis University, Hungary
- These authors contributed equally to this work
| | - László Kocsis
- Institute of Translational Medicine, Semmelweis University, Hungary
| | - Péter Hermán
- Department of Radiology and Biomedical Imaging, Yale University, New Haven, CT 06520, USA
| | - Dario Caccia
- Department of Biomedical Science and Technology, University of Milan, Italy
- Department of Food and Drug, University of Parma, Italy
| | - Michele Perrella
- Department of Biomedical Science and Technology, University of Milan, Italy
| | - Andrea Mozzarelli
- Department of Food and Drug, University of Parma, Italy
- Institute of Biophysics, National Research Council, Pisa, Italy
- Biopharmanet-TEC, University of Parma, Italy
| | - Luca Ronda
- Institute of Biophysics, National Research Council, Pisa, Italy
- Biopharmanet-TEC, University of Parma, Italy
- Department of Medicine and Surgery, University of Parma, Parma, Italy
| | - Domokos Mathe
- CROmed Research and Service Centers Ltd., Budapest, Hungary
| | - Andras Eke
- Institute of Translational Medicine, Semmelweis University, Hungary
- Department of Physiology, Semmelweis University, Hungary
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125
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Kedarasetti RT, Drew PJ, Costanzo F. Arterial pulsations drive oscillatory flow of CSF but not directional pumping. Sci Rep 2020; 10:10102. [PMID: 32572120 PMCID: PMC7308311 DOI: 10.1038/s41598-020-66887-w] [Citation(s) in RCA: 49] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2020] [Accepted: 05/28/2020] [Indexed: 01/05/2023] Open
Abstract
The brain lacks a traditional lymphatic system for metabolite clearance. The existence of a "glymphatic system" where metabolites are removed from the brain's extracellular space by convective exchange between interstitial fluid (ISF) and cerebrospinal fluid (CSF) along the paravascular spaces (PVS) around cerebral blood vessels has been controversial. While recent work has shown clear evidence of directional flow of CSF in the PVS in anesthetized mice, the driving force for the observed fluid flow remains elusive. The heartbeat-driven peristaltic pulsation of arteries has been proposed as a probable driver of directed CSF flow. In this study, we use rigorous fluid dynamic simulations to provide a physical interpretation for peristaltic pumping of fluids. Our simulations match the experimental results and show that arterial pulsations only drive oscillatory motion of CSF in the PVS. The observed directional CSF flow can be explained by naturally occurring and/or experimenter-generated pressure differences.
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Affiliation(s)
- Ravi Teja Kedarasetti
- Department of Engineering Science and Mechanics, The Pennsylvania State University, University Park, PA, United States
- Center for Neural Engineering, The Pennsylvania State University, University Park, PA, United States
| | - Patrick J Drew
- Department of Engineering Science and Mechanics, The Pennsylvania State University, University Park, PA, United States
- Center for Neural Engineering, The Pennsylvania State University, University Park, PA, United States
- Department of Biomedical Engineering, The Pennsylvania State University, University Park, PA, United States
- Department of Neurosurgery, The Pennsylvania State University, University Park, PA, United States
| | - Francesco Costanzo
- Department of Engineering Science and Mechanics, The Pennsylvania State University, University Park, PA, United States.
- Center for Neural Engineering, The Pennsylvania State University, University Park, PA, United States.
- Department of Biomedical Engineering, The Pennsylvania State University, University Park, PA, United States.
- Department of Mathematics, The Pennsylvania State University, University Park, PA, United States.
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126
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Park SY, Matte A, Jung Y, Ryu J, Anand WB, Han EY, Liu M, Carbone C, Melisi D, Nagasawa T, Locascio JJ, Lin CP, Silberstein LE, De Franceschi L. Pathologic angiogenesis in the bone marrow of humanized sickle cell mice is reversed by blood transfusion. Blood 2020; 135:2071-2084. [PMID: 31990287 PMCID: PMC7273832 DOI: 10.1182/blood.2019002227] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2019] [Accepted: 01/18/2020] [Indexed: 12/27/2022] Open
Abstract
Sickle cell disease (SCD) is a monogenic red blood cell (RBC) disorder with high morbidity and mortality. Here, we report, for the first time, the impact of SCD on the bone marrow (BM) vascular niche, which is critical for hematopoiesis. In SCD mice, we find a disorganized and structurally abnormal BM vascular network of increased numbers of highly tortuous arterioles occupying the majority of the BM cavity, as well as fragmented sinusoidal vessels filled with aggregates of erythroid and myeloid cells. By in vivo imaging, sickle and control RBCs have significantly slow intravascular flow speeds in sickle cell BM but not in control BM. In sickle cell BM, we find increased reactive oxygen species production in expanded erythroblast populations and elevated levels of HIF-1α. The SCD BM exudate exhibits increased levels of proangiogenic growth factors and soluble vascular cell adhesion molecule-1. Transplantation of SCD mouse BM cells into wild-type mice recapitulates the SCD vascular phenotype. Our data provide a model of SCD BM, in which slow RBC flow and vaso-occlusions further diminish local oxygen availability in the physiologic hypoxic BM cavity. These events trigger a milieu that is conducive to aberrant vessel growth. The distorted neovascular network is completely reversed by a 6-week blood transfusion regimen targeting hemoglobin S to <30%, highlighting the plasticity of the vascular niche. A better insight into the BM microenvironments in SCD might provide opportunities to optimize approaches toward efficient and long-term hematopoietic engraftment in the context of curative therapies.
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Affiliation(s)
- Shin-Young Park
- Transfusion Medicine, Boston Children's Hospital and Harvard Medical School, Boston, MA
| | - Alessandro Matte
- Department of Medicine, University of Verona and Azienda Ospedaliera Universitaria Integrata Verona, Verona, Italy
| | - Yookyung Jung
- Center for Molecular Spectroscopy and Dynamics, Institute for Basic Science, Seoul, Republic of Korea
- Center for Systems Biology and Wellman Center for Photomedicine, Massachusetts General Hospital and Harvard Medical School, Boston, MA
| | - Jina Ryu
- Transfusion Medicine, Boston Children's Hospital and Harvard Medical School, Boston, MA
| | - Wilson Babu Anand
- Department of Medicine, University of Verona and Azienda Ospedaliera Universitaria Integrata Verona, Verona, Italy
| | - Eun-Young Han
- Transfusion Medicine, Boston Children's Hospital and Harvard Medical School, Boston, MA
| | - Min Liu
- Transfusion Medicine, Boston Children's Hospital and Harvard Medical School, Boston, MA
| | - Carmine Carbone
- Department of Medicine, University of Verona and Azienda Ospedaliera Universitaria Integrata Verona, Verona, Italy
| | - Davide Melisi
- Department of Medicine, University of Verona and Azienda Ospedaliera Universitaria Integrata Verona, Verona, Italy
| | - Takashi Nagasawa
- Laboratory of Stem Cell Biology and Developmental Immunology, Graduate School of Frontier Biosciences and Graduate School of Medicine, Osaka University, Osaka, Japan
| | - Joseph J Locascio
- Massachusetts Alzheimer's Disease Research Center, Massachusetts General Hospital and Harvard Medical School, Boston, MA; and
| | - Charles P Lin
- Center for Systems Biology and Wellman Center for Photomedicine, Massachusetts General Hospital and Harvard Medical School, Boston, MA
| | - Leslie E Silberstein
- Transfusion Medicine, Boston Children's Hospital and Harvard Medical School, Boston, MA
- Harvard Stem Cell Institute, Cambridge, MA
| | - Lucia De Franceschi
- Department of Medicine, University of Verona and Azienda Ospedaliera Universitaria Integrata Verona, Verona, Italy
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127
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Sancho M, Welsh DG. K IR channels in the microvasculature: Regulatory properties and the lipid-hemodynamic environment. CURRENT TOPICS IN MEMBRANES 2020; 85:227-259. [PMID: 32402641 DOI: 10.1016/bs.ctm.2020.01.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
Abstract
Basal tone and perfusion control is set in cerebral arteries by the sensing of pressure and flow, key hemodynamic stimuli. These forces establish a contractile foundation within arterial networks upon which local neurovascular stimuli operate. This fundamental process is intimately tied to arterial VM and the rise in cytosolic [Ca2+] by the graded opening of voltage-operated Ca2+ channels. Arterial VM is in turn controlled by a dynamic interaction among several resident ion channels, KIR being one of particular significance. As the name suggests, KIR displays strong inward rectification, retains a small outward component, potentiated by extracellular K+ and blocked by micromolar Ba2+. Cerebrovascular KIR is unique from other K+ currents as it is present in both smooth muscle and endothelium yet lacking in classical regulatory modulation. Such observations have fostered the view that KIR is nothing more than a background conductance, activated by extracellular K+ and which passively facilitates dilation. Recent work in cell model systems has; however, identified two membrane lipids, phosphatidylinositol 4,5-bisphosphate (PIP2) and cholesterol, that interact with KIR2.x, to stabilize the channel in the preferred open or silent state, respectively. Translating this unique form of regulation, recent studies have demonstrated that specific lipid-protein interactions enable unique KIR populations to sense distinct hemodynamic stimuli and set basal tone. This review summarizes the current knowledge of vascular KIR channels and how the lipid and hemodynamic impact their activity.
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Affiliation(s)
- Maria Sancho
- Robarts Research Institute and the Department of Physiology & Pharmacology, University of Western Ontario, London, ON, Canada
| | - Donald G Welsh
- Robarts Research Institute and the Department of Physiology & Pharmacology, University of Western Ontario, London, ON, Canada.
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128
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Liu H, Chen X, Deng X, Zhuang Z, Tong S, Xie W, Li J, Qiu P, Wang K. In vivo deep-brain blood flow speed measurement through third-harmonic generation imaging excited at the 1700-nm window. BIOMEDICAL OPTICS EXPRESS 2020; 11:2738-2744. [PMID: 32499956 PMCID: PMC7249836 DOI: 10.1364/boe.389662] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Revised: 03/14/2020] [Accepted: 04/15/2020] [Indexed: 05/28/2023]
Abstract
Measurement of the hemodynamic physical parameter blood flow speed in the brain in vivo is key to understanding brain physiology and pathology. 2-photon fluorescence microscopy with single blood vessel resolution is typically used, which necessitates injection of toxic fluorescent dyes. Here we demonstrate a label-free nonlinear optical technique, third-harmonic generation microscopy excited at the 1700-nm window, that is promising for such measurement. Using a simple femtosecond laser system based on soliton self-frequency shift, we can measure blood flow speed through the whole cortical grey matter, even down to the white matter layer. Together with 3-photon fluorescence microscopy, we further demonstrate that the blood vessel walls generate strong THG signals, and that plasma and circulating blood cells are mutually exclusive in space. This technique can be readily applied to brain research.
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Affiliation(s)
- Hongji Liu
- Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen, 518060, China
| | - Xinlin Chen
- Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen, 518060, China
| | - Xiangquan Deng
- Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen, 518060, China
| | - Ziwei Zhuang
- Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen, 518060, China
| | - Shen Tong
- Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen, 518060, China
| | - Weixin Xie
- College of Electronics and information engineering, Shenzhen University, Shenzhen, 518060, China
| | - Jia Li
- Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen, 518060, China
| | - Ping Qiu
- Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen, 518060, China
| | - Ke Wang
- Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen, 518060, China
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129
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He XF, Zeng YX, Li G, Feng YK, Wu C, Liang FY, Zhang Y, Lan Y, Xu GQ, Pei Z. Extracellular ASC exacerbated the recurrent ischemic stroke in an NLRP3-dependent manner. J Cereb Blood Flow Metab 2020; 40:1048-1060. [PMID: 31216943 PMCID: PMC7181081 DOI: 10.1177/0271678x19856226] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Using a photothrombotic mouse model of single stroke, we show that a single stroke onset increases the nuclear factor-κB (NF-κB), NLR family CARD domain containing protein 4 (NLRC4), and absent in melanoma 2 (AIM2) inflammasomes, as well as the mRNA levels of NLRP3. Next, using a photothrombotic mouse model of recurrent stroke, we found that recurrent strokes increased the activation of NLRP3, exacerbated the brain damage and the pro-inflammatory response in wild type (WT) mice, but not in NLRP3 knockout (NLRP3 KO) mice. Additionally, we found that apoptosis-associated speck-like protein containing a CARD (ASC) protein level surrounding the infarct area was comparatively increased, but that ASC specks outside of microglia in both the ipsilateral and contralateral of stroke site were decreased in NLRP3 KO mice relative to wild-type (WT) controls, and the number of ASC specks surrounding the second infarct area was positively correlated to the damage scores. Mechanistically, we found that recombinant ASC (RecASC) activated NLRP3 and induced pro-inflammatory responses, exacerbating the outcome of ischemic stroke, in WT mice, but not in NLRP3 KO mice. We therefore conclude that the NLRP3 inflammasome is activated by two attacks of stroke, which act together with ASC to exacerbate recurrent strokes.
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Affiliation(s)
- Xiao-Fei He
- Department of Neurology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Yi-Xuan Zeng
- Department of Neurology, Shenzhen 2nd People's Hospital, The First Affiliated Hospital of Shenzhen University, Health Science Center, Shenzhen, Guangdong, China
| | - Ge Li
- Guangdong Provincial Key Labortory of Labortory Animals, Guangdong Laboratory Animals Monitoring Institute, Guangzhou, China
| | - Yu-Kun Feng
- Department of Neurology, The Fifth Affiliated Hospital, Sun Yat-sen University, Zhuhai, China
| | - Cheng Wu
- Department of Rehabilitation Medicine, Guangzhou First People's Hospital, Guangzhou Medical University, Guangzhou, China
| | - Feng-Yin Liang
- Department of Neurology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Yu Zhang
- Guangdong Provincial Key Labortory of Labortory Animals, Guangdong Laboratory Animals Monitoring Institute, Guangzhou, China
| | - Yue Lan
- Department of Rehabilitation Medicine, Guangzhou First People's Hospital, Guangzhou Medical University, Guangzhou, China.,Department of Rehabilitation Medicine, The Second Affiliated Hospital of South China University of Technology, Guangzhou, China
| | - Guang-Qing Xu
- Department of Rehabilitation Medicine, Beijing Tiantan Hospital, Capital Medical University, Beijing, China.,China National Clinical Research Center for Neurological Diseases, Beijing, China
| | - Zhong Pei
- Department of Neurology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
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130
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Ma J, Ma Y, Shuaib A, Winship IR. Impaired Collateral Flow in Pial Arterioles of Aged Rats During Ischemic Stroke. Transl Stroke Res 2020; 11:243-253. [PMID: 31203565 PMCID: PMC7067739 DOI: 10.1007/s12975-019-00710-1] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Revised: 05/02/2019] [Accepted: 06/05/2019] [Indexed: 02/05/2023]
Abstract
Cerebral collateral circulation and age are critical factors in determining outcome from acute ischemic stroke. Aging may lead to rarefaction of cerebral collaterals, and thereby accelerate ischemic injury by reducing penumbral blood flow. Dynamic changes in pial collaterals after onset of cerebral ischemia may vary with age but have not been extensively studied. Here, laser speckle contrast imaging (LSCI) and two-photon laser scanning microscopy (TPLSM) were combined to monitor cerebral pial collaterals between the anterior cerebral artery (ACA) and the middle cerebral artery (MCA) in young adult and aged male Sprague Dawley rats during distal middle cerebral artery occlusion (dMCAo). Histological analysis showed that aged rats had significantly greater volumes of ischemic damage than young rats. LSCI showed that cerebral collateral perfusion declined over time after stroke in aged and young rats, and that this decline was significantly greater in aged rats. TPLSM demonstrated that pial arterioles narrowed faster after dMCAo in aged rats compared to young adult rats. Notably, while arteriole vessel narrowing was comparable 4.5 h after ischemic onset in aged and young adult rats, red blood cell velocity was stable in young adults but declined over time in aged rats. Overall, red blood cell flux through pial arterioles was significantly reduced at all time-points after 90 min post-dMCAo in aged rats relative to young adult rats. Thus, collateral failure is more severe in aged rats with significantly impaired pial collateral dynamics (reduced diameter, red blood cell velocity, and red blood cell flux) relative to young adult rats.
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Affiliation(s)
- Junqiang Ma
- Neurochemical Research Unit, Department of Psychiatry, Faculty of Medicine and Dentistry, University of Alberta, 12-127 Clinical Sciences Building, Edmonton, AB, T6G 2R3, Canada
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, AB, Canada
- First Affiliated Hospital, Shantou University Medical College, Shantou, Guangdong, China
| | - Yonglie Ma
- Neurochemical Research Unit, Department of Psychiatry, Faculty of Medicine and Dentistry, University of Alberta, 12-127 Clinical Sciences Building, Edmonton, AB, T6G 2R3, Canada
| | - Ashfaq Shuaib
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, AB, Canada
- Division of Neurology, Department of Medicine, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada
| | - Ian R Winship
- Neurochemical Research Unit, Department of Psychiatry, Faculty of Medicine and Dentistry, University of Alberta, 12-127 Clinical Sciences Building, Edmonton, AB, T6G 2R3, Canada.
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, AB, Canada.
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131
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Bardet SM, Cortese J, Blanc R, Mounayer C, Rouchaud A. Multiphoton microscopy for pre-clinical evaluation of flow-diverter stents for treating aneurysms. J Neuroradiol 2020; 48:200-206. [PMID: 32205257 DOI: 10.1016/j.neurad.2020.03.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2019] [Revised: 03/09/2020] [Accepted: 03/10/2020] [Indexed: 12/17/2022]
Abstract
BACKGROUND Conventional histological analyses are the gold standard for the study of aneurysms and vascular pathologies in pre-clinical research. Over the past decade, in vivo and ex vivo imaging using multiphoton microscopy have emerged as powerful pre-clinical tools for detailed tissue analyses that can assess morphology, the extracellular matrix (ECM), cell density and vascularisation. Multiphoton microscopy allows for deeper tissue penetration with minor phototoxicity. OBJECTIVE The present study aimed to demonstrate the current status of multimodality imaging, including multiphoton microscopy, for detailed analyses of neo-endothelialisation and ECM evolution after flow-diverter stent (FDS) treatment in an experimental rabbit model of aneurysms. METHODS Multiphoton microscopy tools for assessing autofluorescence and second harmonic generation (SHG) signals from biological tissues were used to evaluate the endovascular treatment of intracranial aneurysms in an animal model of aneurysms (pig, rabbit). Results from multiphoton microscopy were compared to those from standard histology, electronic and bright field microscopy. CONCLUSIONS The present study describes novel evaluation modes based on multiphoton microscopy for visualising tissue morphology (e.g., collagen, elastin, and cells) to qualify and quantify the extent of neo-intimal formation of covered arteries and device integration into the arterial wall using a rabbit model of intracranial aneurysms treated with FDS.
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Affiliation(s)
- Sylvia M Bardet
- University of Limoges, 123, avenue Albert-Thomas, XLIM UMR CNRS 7252, 87060 Limoges, France.
| | - Jonathan Cortese
- Bichat University Hospital, INSERM U1148-LVTS, Paris, France; Bicetre Hospital, Department of Interventional Neuroradiology, Paris, France
| | - Raphaël Blanc
- Department of Interventional Neuroradiology, Fondation Ophtalmologique Adolphe-de-Rothschild, Paris, France
| | - Charbel Mounayer
- University of Limoges, 123, avenue Albert-Thomas, XLIM UMR CNRS 7252, 87060 Limoges, France; University Hospital, Department of Interventional Neuroradiology, Limoges, France
| | - Aymeric Rouchaud
- University of Limoges, 123, avenue Albert-Thomas, XLIM UMR CNRS 7252, 87060 Limoges, France; University Hospital, Department of Interventional Neuroradiology, Limoges, France.
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132
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Han X, Chai Z, Ping X, Song LJ, Ma C, Ruan Y, Jin X. In vivo Two-Photon Imaging Reveals Acute Cerebral Vascular Spasm and Microthrombosis After Mild Traumatic Brain Injury in Mice. Front Neurosci 2020; 14:210. [PMID: 32210758 PMCID: PMC7077429 DOI: 10.3389/fnins.2020.00210] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2019] [Accepted: 02/25/2020] [Indexed: 12/23/2022] Open
Abstract
Mild traumatic brain injury (mTBI), or concussion, is reported to interfere with cerebral blood flow and microcirculation in patients, but our current understanding is quite limited and the results are often controversial. Here we used longitudinal in vivo two-photon imaging to investigate dynamic changes in cerebral vessels and velocities of red blood cells (RBC) following mTBI. Closed-head mTBI induced using a controlled cortical impact device resulted in a significant reduction of dwell time in a Rotarod test but no significant change in water maze test. Cerebral blood vessels were repeatedly imaged through a thinned skull window at baseline, 0.5, 1, 6 h, and 1 day following mTBI. In both arterioles and capillaries, their diameters and RBC velocities were significantly decreased at 0.5, 1, and 6 h after injury, and recovered in 1 day post-mTBI. In contrast, decreases in the diameter and RBC velocity of venules occurred only in 0.5–1 h after mTBI. We also observed formation and clearance of transient microthrombi in capillaries within 1 h post-mTBI. We concluded that in vivo two-photon imaging is useful for studying earlier alteration of vascular dynamics after mTBI and that mTBI induced reduction of cerebral blood flow, vasospasm, and formation of microthrombi in the acute stage following injury. These changes may contribute to early brain functional deficits of mTBI.
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Affiliation(s)
- Xinjia Han
- Spinal Cord and Brain Injury Research Group, Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, IN, United States.,Department of Anatomy and Cell Biology, Indiana University School of Medicine, Indianapolis, IN, United States.,Department of Obstetrics and Gynecology, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou, China.,GHM Institute of CNS Regeneration (GHMICR), Jinan University, Guangzhou, China
| | - Zhi Chai
- Neurobiology Research Center, Shanxi Key Laboratory of Innovative Drugs for Serious Illness, College of Basic Medicine, Shaanxi University of Chinese Medicine, Jinzhong, China
| | - Xingjie Ping
- Spinal Cord and Brain Injury Research Group, Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, IN, United States.,Department of Anatomy and Cell Biology, Indiana University School of Medicine, Indianapolis, IN, United States
| | - Li-Juan Song
- Neurobiology Research Center, Shanxi Key Laboratory of Innovative Drugs for Serious Illness, College of Basic Medicine, Shaanxi University of Chinese Medicine, Jinzhong, China
| | - Cungen Ma
- Neurobiology Research Center, Shanxi Key Laboratory of Innovative Drugs for Serious Illness, College of Basic Medicine, Shaanxi University of Chinese Medicine, Jinzhong, China
| | - Yiwen Ruan
- GHM Institute of CNS Regeneration (GHMICR), Jinan University, Guangzhou, China.,Co-innovation Center of Neuroregeneration, Nantong University, Nantong, China
| | - Xiaoming Jin
- Spinal Cord and Brain Injury Research Group, Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, IN, United States.,Department of Anatomy and Cell Biology, Indiana University School of Medicine, Indianapolis, IN, United States
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133
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Li B, Ohtomo R, Thunemann M, Adams SR, Yang J, Fu B, Yaseen MA, Ran C, Polimeni JR, Boas DA, Devor A, Lo EH, Arai K, Sakadžić S. Two-photon microscopic imaging of capillary red blood cell flux in mouse brain reveals vulnerability of cerebral white matter to hypoperfusion. J Cereb Blood Flow Metab 2020; 40:501-512. [PMID: 30829101 PMCID: PMC7026840 DOI: 10.1177/0271678x19831016] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/17/2018] [Revised: 01/19/2019] [Accepted: 01/21/2019] [Indexed: 01/15/2023]
Abstract
Despite the importance of understanding the regulation of microvascular blood flow in white matter, no data on subcortical capillary blood flow parameters are available, largely due to the lack of appropriate imaging methods. To address this knowledge gap, we employed two-photon microscopy using a far-red fluorophore Alexa680 and photon-counting detection to measure capillary red blood cell (RBC) flux in both cerebral gray and white matter, in isoflurane-anesthetized mice. We have found that in control animals, baseline capillary RBC flux in the white matter was significantly higher than in the adjacent cerebral gray matter. In response to mild hypercapnia, RBC flux in the white matter exhibited significantly smaller fractional increase than in the gray matter. Finally, during global cerebral hypoperfusion, RBC flux in the white matter was reduced significantly in comparison to the controls, while RBC flux in the gray matter was preserved. Our results suggest that blood flow in the white matter may be less efficiently regulated when challenged by physiological perturbations as compared to the gray matter. Importantly, the blood flow in the white matter may be more susceptible to hypoperfusion than in the gray matter, potentially exacerbating the white matter deterioration in brain conditions involving global cerebral hypoperfusion.
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Affiliation(s)
- Baoqiang Li
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA
| | - Ryo Ohtomo
- Departments of Radiology and Neurology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA
| | - Martin Thunemann
- Department of Neurosciences, University of California San Diego, La Jolla, CA, USA
| | - Stephen R Adams
- Department of Pharmacology, University of California, San Diego, La Jolla, CA, USA
| | - Jing Yang
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA
| | - Buyin Fu
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA
| | - Mohammad A Yaseen
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA
| | - Chongzhao Ran
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA
| | - Jonathan R Polimeni
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA
| | - David A Boas
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA
- Department of Biomedical Engineering, Boston University, Boston, MA, USA
| | - Anna Devor
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA
- Department of Neurosciences, University of California San Diego, La Jolla, CA, USA
- Department of Radiology, University of California San Diego, La Jolla, CA, USA
| | - Eng H Lo
- Departments of Radiology and Neurology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA
| | - Ken Arai
- Departments of Radiology and Neurology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA
| | - Sava Sakadžić
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA
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134
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Shrestha B, DeLuna F, Anastasio MA, Yong Ye J, Brey EM. Photoacoustic Imaging in Tissue Engineering and Regenerative Medicine. TISSUE ENGINEERING. PART B, REVIEWS 2020; 26:79-102. [PMID: 31854242 PMCID: PMC7041335 DOI: 10.1089/ten.teb.2019.0296] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Accepted: 12/13/2019] [Indexed: 12/16/2022]
Abstract
Several imaging modalities are available for investigation of the morphological, functional, and molecular features of engineered tissues in small animal models. While research in tissue engineering and regenerative medicine (TERM) would benefit from a comprehensive longitudinal analysis of new strategies, researchers have not always applied the most advanced methods. Photoacoustic imaging (PAI) is a rapidly emerging modality that has received significant attention due to its ability to exploit the strong endogenous contrast of optical methods with the high spatial resolution of ultrasound methods. Exogenous contrast agents can also be used in PAI for targeted imaging. Applications of PAI relevant to TERM include stem cell tracking, longitudinal monitoring of scaffolds in vivo, and evaluation of vascularization. In addition, the emerging capabilities of PAI applied to the detection and monitoring of cancer and other inflammatory diseases could be exploited by tissue engineers. This article provides an overview of the operating principles of PAI and its broad potential for application in TERM. Impact statement Photoacoustic imaging, a new hybrid imaging technique, has demonstrated high potential in the clinical diagnostic applications. The optical and acoustic aspect of the photoacoustic imaging system works in harmony to provide better resolution at greater tissue depth. Label-free imaging of vasculature with this imaging can be used to track and monitor disease, as well as the therapeutic progression of treatment. Photoacoustic imaging has been utilized in tissue engineering to some extent; however, the full benefit of this technique is yet to be explored. The increasing availability of commercial photoacoustic systems will make application as an imaging tool for tissue engineering application more feasible. This review first provides a brief description of photoacoustic imaging and summarizes its current and potential application in tissue engineering.
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Affiliation(s)
- Binita Shrestha
- Department of Biomedical Engineering, University of Texas at San Antonio, San Antonio, Texas
| | - Frank DeLuna
- Department of Biomedical Engineering, University of Texas at San Antonio, San Antonio, Texas
| | - Mark A. Anastasio
- Department of Bioengineering, University of Illinois at Urbana-Champaign, Urbana, Illinois
| | - Jing Yong Ye
- Department of Biomedical Engineering, University of Texas at San Antonio, San Antonio, Texas
| | - Eric M. Brey
- Department of Biomedical Engineering, University of Texas at San Antonio, San Antonio, Texas
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135
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Narita A, Ohkubo M. A pitfall of using the circular-edge technique with image averaging for spatial resolution measurement in iteratively reconstructed CT images. J Appl Clin Med Phys 2020; 21:144-151. [PMID: 31957969 PMCID: PMC7020989 DOI: 10.1002/acm2.12821] [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] [Subscribe] [Scholar Register] [Received: 06/03/2019] [Revised: 10/07/2019] [Accepted: 12/17/2019] [Indexed: 12/19/2022] Open
Abstract
The circular‐edge technique using a low‐contrast cylindrical object is commonly used to measure the modulation transfer functions (MTFs) in computed tomography (CT) images reconstructed with iterative reconstruction (IR) algorithms. This method generally entails averaging multiple images of the cylinder to reduce the image noise. We suspected that the cylinder edge shape depicted in the IR images might exhibit slight deformation with respect to the true shape because of the intrinsic nonlinearity of IR algorithms. Image averaging can reduce the image noise, but does not effectively improve the deformation of the edge shape; thereby causing errors in the MTF measurements. We address this issue and propose a method to correct the MTF. We scanned a phantom including cylindrical objects with a CT scanner (Ingenuity Elite, Philips Healthcare). We obtained cylinder images with iterative model reconstruction (IMR) algorithms. The images suggested that the depicted edge shape deforms and fluctuates depending on slice positions. Because of this deformation, image averaging can potentially cause additional blurring. We define the deformation function D that describes the additional blurring, and obtain D by analyzing multiple images. The MTF measured by the circular‐edge method (referred to as MTF') can be thought of as the multiplication of the true MTF by the Fourier transformation (FT) of D. We thus obtain the corrected MTF (MTFcorrected) by dividing MTF' by the FT of D. We validate our correction method by comparing the calculated images based on the convolution theorem using MTF' and MTFcorrected with the actual images obtained with the scanner. The calculated image using MTFcorrected is more similar to the actual image compared with the image calculated using MTF', particularly in edge regions. We describe a pitfall in MTF measurement using the circular‐edge technique with image averaging, and suggest a method to correct it.
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Affiliation(s)
- Akihiro Narita
- Graduate School of Health Sciences, Niigata University, Chuo-ku, Niigata, Japan
| | - Masaki Ohkubo
- Graduate School of Health Sciences, Niigata University, Chuo-ku, Niigata, Japan
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136
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Zhang Q, Roche M, Gheres KW, Chaigneau E, Kedarasetti RT, Haselden WD, Charpak S, Drew PJ. Cerebral oxygenation during locomotion is modulated by respiration. Nat Commun 2019; 10:5515. [PMID: 31797933 PMCID: PMC6893036 DOI: 10.1038/s41467-019-13523-5] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2019] [Accepted: 11/12/2019] [Indexed: 12/17/2022] Open
Abstract
In the brain, increased neural activity is correlated with increases of cerebral blood flow and tissue oxygenation. However, how cerebral oxygen dynamics are controlled in the behaving animal remains unclear. We investigated to what extent cerebral oxygenation varies during locomotion. We measured oxygen levels in the cortex of awake, head-fixed mice during locomotion using polarography, spectroscopy, and two-photon phosphorescence lifetime measurements of oxygen sensors. We find that locomotion significantly and globally increases cerebral oxygenation, specifically in areas involved in locomotion, as well as in the frontal cortex and the olfactory bulb. The oxygenation increase persists when neural activity and functional hyperemia are blocked, occurred both in the tissue and in arteries feeding the brain, and is tightly correlated with respiration rate and the phase of respiration cycle. Thus, breathing rate is a key modulator of cerebral oxygenation and should be monitored during hemodynamic imaging, such as in BOLD fMRI.
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Affiliation(s)
- Qingguang Zhang
- Department of Engineering Science and Mechanics, The Pennsylvania State University, University Park, PA, USA
| | - Morgane Roche
- Institut National de la Santé et de la Recherche Médicale, U1128, Paris, France.,Laboratory of Neurophysiology and New Microscopies, Université Paris Descartes, Paris, France
| | - Kyle W Gheres
- Graduate Program in Molecular Cellular and Integrative Biosciences, The Pennsylvania State University, University Park, PA, USA
| | - Emmanuelle Chaigneau
- Institut National de la Santé et de la Recherche Médicale, U1128, Paris, France.,Laboratory of Neurophysiology and New Microscopies, Université Paris Descartes, Paris, France
| | - Ravi T Kedarasetti
- Department of Engineering Science and Mechanics, The Pennsylvania State University, University Park, PA, USA
| | - William D Haselden
- Medical Scientist Training Program and Neuroscience Graduate Program, The Pennsylvania State University, University Park, PA, USA
| | - Serge Charpak
- Institut National de la Santé et de la Recherche Médicale, U1128, Paris, France.,Laboratory of Neurophysiology and New Microscopies, Université Paris Descartes, Paris, France
| | - Patrick J Drew
- Department of Engineering Science and Mechanics, The Pennsylvania State University, University Park, PA, USA. .,Department of Neurosurgery and Department of Biomedical Engineering, The Pennsylvania State University, University Park, PA, USA.
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137
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Shin P, Choi W, Joo J, Oh WY. Quantitative hemodynamic analysis of cerebral blood flow and neurovascular coupling using optical coherence tomography angiography. J Cereb Blood Flow Metab 2019; 39:1983-1994. [PMID: 29757059 PMCID: PMC6775585 DOI: 10.1177/0271678x18773432] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Functional hyperemia in the rat cortex was investigated using high-speed optical coherence tomography (OCT) angiography and Doppler OCT. OCT angiography (OCTA) was performed to image the hemodynamic stimulus-response over a wide field of view. Temporal changes in vessel diameters in different vessel compartments, which were determined as the diameters of erythrocyte flows in OCT angiograms, were measured in order to monitor localized hemodynamic changes. Our results showed that the dilation of arterioles at the site of activation was accompanied by the dilation of upstream arteries. Relatively negligible dilation was observed in veins. An increase in the OCTA signal was observed during stimulus in multiple capillaries, which may imply that capillary blood flow increases as a result of the expanded arterial blood volume. These results agree with previous observations using two-photon laser scanning microscopy (TPLSM). Doppler OCT was performed to quantitatively measure stimulus-induced blood flow response in pial arteries. The measurement showed small but clear hemodynamic response in upstream arteries with diameters exceeding 100 μm. Our results demonstrate the potential of OCTA and Doppler OCT for the investigation of neurovascular coupling in small animal models.
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Affiliation(s)
- Paul Shin
- Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Republic of Korea.,KI for Health Science and Technology, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Republic of Korea
| | - WooJhon Choi
- KI for Health Science and Technology, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Republic of Korea
| | - JongYoon Joo
- Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Republic of Korea.,KI for Health Science and Technology, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Republic of Korea
| | - Wang-Yuhl Oh
- Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Republic of Korea.,KI for Health Science and Technology, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Republic of Korea
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138
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Klein SP, De Sloovere V, Meyfroidt G, Depreitere B. Autoregulation assessment by direct visualisation of pial arterial blood flow in the piglet brain. Sci Rep 2019; 9:13333. [PMID: 31527671 PMCID: PMC6746693 DOI: 10.1038/s41598-019-50046-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2019] [Accepted: 09/04/2019] [Indexed: 12/22/2022] Open
Abstract
Impairment of cerebrovascular autoregulation (CAR) is common after brain injury, although the pathophysiology remains elusive. The mechanisms of vascular dysregulation, their impact on brain function, and potential therapeutic implications are still incompletely understood. Clinical assessment of CAR remains challenging. Observational studies suggest that CAR impairment is associated with worse outcomes, and that optimization of cerebral blood flow (CBF) by individual arterial blood pressure (ABP) targets could potentially improve outcome. We present a porcine closed cranial window model that measures the hemodynamic response of pial arterioles, the main site of CBF control, based on changes in their diameter and red blood cell velocity. This quantitative direct CAR assessment is compared to laser Doppler flow (LDF). CAR breakpoints are determined by segmented regression analysis and validated using LDF and brain tissue oxygen pressure. Using a standardized cortical impact, CAR impairment in traumatic brain injury can be studied using our method of combining pial arteriolar diameter and RBC velocity to quantify RBC flux in a large animal model. The model has numerous potential applications to investigate CAR physiology and pathophysiology of CAR impairment after brain injury, the impact of therapeutic interventions, drugs, and other confounders, or to develop personalized ABP management strategies.
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Affiliation(s)
- S P Klein
- Department of Neurosurgery, University Hospitals Leuven, Leuven, Belgium.
| | - V De Sloovere
- Department of Anesthesiology, University Hospitals Leuven, Leuven, Belgium
| | - G Meyfroidt
- Department of Intensive Care Medicine, University Hospitals Leuven, Leuven, Belgium
| | - B Depreitere
- Department of Neurosurgery, University Hospitals Leuven, Leuven, Belgium
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139
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Taylor AJ, Kim JH, Singh V, Halfen EJ, Pfeuffer J, Ress D. More than BOLD: Dual-spin populations create functional contrast. Magn Reson Med 2019; 83:681-694. [PMID: 31423634 DOI: 10.1002/mrm.27941] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Revised: 07/16/2019] [Accepted: 07/21/2019] [Indexed: 11/06/2022]
Abstract
PURPOSE Functional MRI contrast has generally been associated with changes in transverse relaxivity caused by blood oxygen concentration, the so-called blood oxygen level dependent contrast. However, this interpretation of fMRI contrast has been called into question by several recent experiments at high spatial resolution. Experiments were conducted to examine contrast dependencies that cannot be explained only by differences in relaxivity in a single-spin population. METHODS Measurements of functional signal and contrast were obtained in human early visual cortex during a high-contrast visual stimulation over a large range of TEs and for several flip angles. Small voxels (1.5 mm) were used to restrict the measurements to cortical gray matter in early visual areas identified using retinotopic mapping procedures. RESULTS Measurements were consistent with models that include 2 spin populations. The dominant population has a relatively short transverse lifetime that is strongly modulated by activation. However, functional contrast is also affected by volume changes between this short-lived population and the longer-lived population. CONCLUSION Some of the previously observed "nonclassical" behaviors of functional contrast can be explained by these interacting dual-spin populations.
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Affiliation(s)
- Amanda J Taylor
- Department of Neuroscience, Baylor College of Medicine, Houston, Texas
| | - Jung H Kim
- Department of Neuroscience, Baylor College of Medicine, Houston, Texas
| | | | | | - Josef Pfeuffer
- Siemens Healthcare, Application Development, Erlangen, Germany
| | - David Ress
- Department of Neuroscience, Baylor College of Medicine, Houston, Texas
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140
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Erdener ŞE, Dalkara T. Small Vessels Are a Big Problem in Neurodegeneration and Neuroprotection. Front Neurol 2019; 10:889. [PMID: 31474933 PMCID: PMC6707104 DOI: 10.3389/fneur.2019.00889] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2019] [Accepted: 08/01/2019] [Indexed: 12/11/2022] Open
Abstract
The cerebral microcirculation holds a critical position to match the high metabolic demand by neuronal activity. Functionally, microcirculation is virtually inseparable from other nervous system cells under both physiological and pathological conditions. For successful bench-to-bedside translation of neuroprotection research, the role of microcirculation in acute and chronic neurodegenerative disorders appears to be under-recognized, which may have contributed to clinical trial failures with some neuroprotectants. Increasing data over the last decade suggest that microcirculatory impairments such as endothelial or pericyte dysfunction, morphological irregularities in capillaries or frequent dynamic stalls in blood cell flux resulting in excessive heterogeneity in capillary transit may significantly compromise tissue oxygen availability. We now know that ischemia-induced persistent abnormalities in capillary flow negatively impact restoration of reperfusion after recanalization of occluded cerebral arteries. Similarly, microcirculatory impairments can accompany or even precede neural loss in animal models of several neurodegenerative disorders including Alzheimer's disease. Macrovessels are relatively easy to evaluate with radiological or experimental imaging methods but they cannot faithfully reflect the downstream microcirculatory disturbances, which may be quite heterogeneous across the tissue at microscopic scale and/or happen fast and transiently. The complexity and size of the elements of microcirculation, therefore, require utilization of cutting-edge imaging techniques with high spatiotemporal resolution as well as multidisciplinary team effort to disclose microvascular-neurodegenerative connection and to test treatment approaches to advance the field. Developments in two photon microscopy, ultrafast ultrasound, and optical coherence tomography provide valuable experimental tools to reveal those microscopic events with high resolution. Here, we review the up-to-date advances in understanding of the primary microcirculatory abnormalities that can result in neurodegenerative processes and the combined neurovascular protection approaches that can prevent acute as well as chronic neurodegeneration.
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Affiliation(s)
- Şefik Evren Erdener
- Institute of Neurological Sciences and Psychiatry, Hacettepe University, Ankara, Turkey
| | - Turgay Dalkara
- Institute of Neurological Sciences and Psychiatry, Hacettepe University, Ankara, Turkey.,Department of Neurology, Faculty of Medicine, Hacettepe University, Ankara, Turkey
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141
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Liu H, Deng X, Tong S, He C, Cheng H, Zhuang Z, Gan M, Li J, Xie W, Qiu P, Wang K. In Vivo Deep-Brain Structural and Hemodynamic Multiphoton Microscopy Enabled by Quantum Dots. NANO LETTERS 2019; 19:5260-5265. [PMID: 31268725 DOI: 10.1021/acs.nanolett.9b01708] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Visualizing deep-brain vasculature and hemodynamics is key to understanding brain physiology and pathology. Among the various adopted imaging modalities, multiphoton microscopy (MPM) is well-known for its deep-brain structural and hemodynamic imaging capability. However, the largest imaging depth in MPM is limited by signal depletion in the deep brain. Here we demonstrate that quantum dots are an enabling material for significantly deeper structural and hemodynamic MPM in mouse brain in vivo. We characterized both three-photon excitation and emission parameters for quantum dots: the measured three-photon cross sections of quantum dots are 4-5 orders of magnitude larger than those of conventional fluorescent dyes excited at the 1700 nm window, while the three-photon emission spectrum measured in the circulating blood in vivo shows a slight red shift and broadening compared with ex vivo measurement. On the basis of these measured results, we further demonstrate both structural and hemodynamic three-photon microscopy in the mouse brain in vivo labeled by quantum dots, at record depths among all MPM modalities at all demonstrated excitation wavelengths.
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Affiliation(s)
- Hongji Liu
- Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Physics and Optoelectronic Engineering , Shenzhen University , Shenzhen , 518060 , China
| | - Xiangquan Deng
- Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Physics and Optoelectronic Engineering , Shenzhen University , Shenzhen , 518060 , China
| | - Shen Tong
- Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Physics and Optoelectronic Engineering , Shenzhen University , Shenzhen , 518060 , China
| | - Chen He
- Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Physics and Optoelectronic Engineering , Shenzhen University , Shenzhen , 518060 , China
| | - Hui Cheng
- Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Physics and Optoelectronic Engineering , Shenzhen University , Shenzhen , 518060 , China
| | - Ziwei Zhuang
- Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Physics and Optoelectronic Engineering , Shenzhen University , Shenzhen , 518060 , China
| | - Mengyao Gan
- Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Physics and Optoelectronic Engineering , Shenzhen University , Shenzhen , 518060 , China
| | - Jia Li
- Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Physics and Optoelectronic Engineering , Shenzhen University , Shenzhen , 518060 , China
| | - Weixin Xie
- College of Electronics and Information Engineering , Shenzhen University , Shenzhen , 518060 , China
| | - Ping Qiu
- Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Physics and Optoelectronic Engineering , Shenzhen University , Shenzhen , 518060 , China
| | - Ke Wang
- Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Physics and Optoelectronic Engineering , Shenzhen University , Shenzhen , 518060 , China
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142
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Orsini F, Fumagalli S, Császár E, Tóth K, De Blasio D, Zangari R, Lénárt N, Dénes Á, De Simoni MG. Mannose-Binding Lectin Drives Platelet Inflammatory Phenotype and Vascular Damage After Cerebral Ischemia in Mice via IL (Interleukin)-1α. Arterioscler Thromb Vasc Biol 2019; 38:2678-2690. [PMID: 30354247 PMCID: PMC6221395 DOI: 10.1161/atvbaha.118.311058] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Supplemental Digital Content is available in the text. Objective— Circulating complement factors are activated by tissue damage and contribute to acute brain injury. The deposition of MBL (mannose-binding lectin), one of the initiators of the lectin complement pathway, on the cerebral endothelium activated by ischemia is a major pathogenic event leading to brain injury. The molecular mechanisms through which MBL influences outcome after ischemia are not understood yet. Approach and Results— Here we show that MBL-deficient (MBL−/−) mice subjected to cerebral ischemia display better flow recovery and less plasma extravasation in the brain than wild-type mice, as assessed by in vivo 2-photon microscopy. This results in reduced vascular dysfunction as shown by the shift from a pro- to an anti-inflammatory vascular phenotype associated with MBL deficiency. We also show that platelets directly bind MBL and that platelets from MBL−/− mice have reduced inflammatory phenotype as indicated by reduced IL-1α (interleukin-1α) content, as early as 6 hours after ischemia. Cultured human brain endothelial cells subjected to oxygen-glucose deprivation and exposed to platelets from MBL−/− mice present less cell death and lower CXCL1 (chemokine [C-X-C motif] ligand 1) release (downstream to IL-1α) than those exposed to wild-type platelets. In turn, MBL deposition on ischemic vessels significantly decreases after ischemia in mice treated with IL-1 receptor antagonist compared with controls, indicating a reciprocal interplay between MBL and IL-1α facilitating endothelial damage. Conclusions— We propose MBL as a hub of pathogenic vascular events. It acts as an early trigger of platelet IL-1α release, which in turn favors MBL deposition on ischemic vessels promoting an endothelial pro-inflammatory phenotype.
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Affiliation(s)
- Franca Orsini
- From the Department of Neuroscience, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Milano, Italy (F.O., S.F., D.D.B., R.Z., M.-G.D.S.)
| | - Stefano Fumagalli
- From the Department of Neuroscience, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Milano, Italy (F.O., S.F., D.D.B., R.Z., M.-G.D.S.)
| | - Eszter Császár
- Laboratory of Neuroimmunology, Institute of Experimental Medicine, Budapest, Hungary (E.C., K.T., N.L., A.D.)
| | - Krisztina Tóth
- Laboratory of Neuroimmunology, Institute of Experimental Medicine, Budapest, Hungary (E.C., K.T., N.L., A.D.)
| | - Daiana De Blasio
- From the Department of Neuroscience, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Milano, Italy (F.O., S.F., D.D.B., R.Z., M.-G.D.S.)
| | - Rosalia Zangari
- From the Department of Neuroscience, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Milano, Italy (F.O., S.F., D.D.B., R.Z., M.-G.D.S.)
| | - Nikolett Lénárt
- Laboratory of Neuroimmunology, Institute of Experimental Medicine, Budapest, Hungary (E.C., K.T., N.L., A.D.)
| | - Ádám Dénes
- Laboratory of Neuroimmunology, Institute of Experimental Medicine, Budapest, Hungary (E.C., K.T., N.L., A.D.)
| | - Maria-Grazia De Simoni
- From the Department of Neuroscience, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Milano, Italy (F.O., S.F., D.D.B., R.Z., M.-G.D.S.)
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143
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Balbi M, Vanni MP, Vega MJ, Silasi G, Sekino Y, Boyd JD, LeDue JM, Murphy TH. Longitudinal monitoring of mesoscopic cortical activity in a mouse model of microinfarcts reveals dissociations with behavioral and motor function. J Cereb Blood Flow Metab 2019; 39:1486-1500. [PMID: 29521138 PMCID: PMC6681536 DOI: 10.1177/0271678x18763428] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/26/2017] [Revised: 01/29/2018] [Accepted: 02/01/2018] [Indexed: 12/14/2022]
Abstract
Small vessel disease is characterized by sporadic obstruction of small vessels leading to neuronal cell death. These microinfarcts often escape detection by conventional magnetic resonance imaging and are identified only upon postmortem examination. Our work explores a brain-wide microinfarct model in awake head-fixed mice, where occlusions of small penetrating arterioles are reproduced by endovascular injection of fluorescent microspheres. Mesoscopic functional connectivity was mapped longitudinally in awake GCaMP6 mice using genetically encoded calcium indicators for transcranial wide-field calcium imaging. Microsphere occlusions were quantified and changes in cerebral blood flow were measured with laser speckle imaging. The neurodeficit score in microinfarct mice was significantly higher than in sham, indicating impairment in motor function. The novel object recognition test showed a reduction in the discrimination index in microinfarct mice compared to sham. Graph-theoretic analysis of functional connectivity did not reveal significant differences in functional connectivity between sham and microinfarct mice. While behavioral tasks revealed impairments following microinfarct induction, the absence of measurable functional alterations in cortical activity has a less straightforward interpretation. The behavioral alterations produced by this model are consistent with alterations observed in human patients suffering from microinfarcts and support the validity of microsphere injection as a microinfarct model.
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Affiliation(s)
- Matilde Balbi
- Department of Psychiatry, Kinsmen
Laboratory of Neurological Research, University of British Columbia, Vancouver,
British Columbia, Canada
| | - Matthieu P Vanni
- Department of Psychiatry, Kinsmen
Laboratory of Neurological Research, University of British Columbia, Vancouver,
British Columbia, Canada
| | - Max J Vega
- Department of Psychology, Motivated
Cognition Lab, University of British Columbia, Vancouver, British Columbia,
Canada
| | - Gergely Silasi
- Department of Psychiatry, Kinsmen
Laboratory of Neurological Research, University of British Columbia, Vancouver,
British Columbia, Canada
| | - Yuki Sekino
- Department of Psychiatry, Kinsmen
Laboratory of Neurological Research, University of British Columbia, Vancouver,
British Columbia, Canada
| | - Jamie D Boyd
- Department of Psychiatry, Kinsmen
Laboratory of Neurological Research, University of British Columbia, Vancouver,
British Columbia, Canada
| | - Jeffrey M LeDue
- Department of Psychiatry, Kinsmen
Laboratory of Neurological Research, University of British Columbia, Vancouver,
British Columbia, Canada
- Djavad Mowafaghian Center for Brain
Health, University of British Columbia, Vancouver, British Columbia, Canada
| | - Timothy H Murphy
- Department of Psychiatry, Kinsmen
Laboratory of Neurological Research, University of British Columbia, Vancouver,
British Columbia, Canada
- Djavad Mowafaghian Center for Brain
Health, University of British Columbia, Vancouver, British Columbia, Canada
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144
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Lee SH, Choe YH, Kang RH, Kim YR, Kim NH, Kang S, Kim Y, Park S, Hyun YM, Kim D. A bright blue fluorescent dextran for two-photon in vivo imaging of blood vessels. Bioorg Chem 2019; 89:103019. [DOI: 10.1016/j.bioorg.2019.103019] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2019] [Revised: 05/01/2019] [Accepted: 05/28/2019] [Indexed: 01/06/2023]
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145
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Luo F, Wu L, Zhang Z, Zhu Z, Liu Z, Guo B, Li N, Ju J, Zhou Q, Li S, Yang X, Mak S, Han Y, Sun Y, Wang Y, Zhang G, Zhang Z. The dual-functional memantine nitrate MN-08 alleviates cerebral vasospasm and brain injury in experimental subarachnoid haemorrhage models. Br J Pharmacol 2019; 176:3318-3335. [PMID: 31180578 DOI: 10.1111/bph.14763] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2018] [Revised: 05/26/2019] [Accepted: 06/03/2019] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND AND PURPOSE Cerebral vasospasm and neuronal apoptosis after subarachnoid haemorrhage (SAH) is the major cause of morbidity and mortality in SAH patients. So far, single-target agents have not prevented its occurrence. Memantine, a non-competitive NMDA re3ceptor antagonist, is known to alleviate brain injury and vasospasm in experimental models of SAH. Impairment of NO availability also contributes to vasospasm. Recently, we designed and synthesized a memantine nitrate MN-08, which has potent dual functions: neuroprotection and vasodilation. Here, we have tested the therapeutic effects of MN-08 in animal models of SAH. EXPERIMENTAL APPROACH Binding to NMDA receptors (expressed in HEK293 cells), NO release and vasodilator effects of MN-08 were assessed in vitro. Therapeutic effects of MN-08 were investigated in vivo, using rat and rabbit SAH models. KEY RESULTS MN-08 bound to the NMDA receptor, slowly releasing NO in vitro and in vivo. Consequently, MN-08 relaxed the pre-contracted middle cerebral artery ex vivo and increased blood flow velocity in small vessels of the mouse cerebral cortex. It did not, however, lower systemic blood pressure. In an endovascular perforation rat model of SAH, MN-08 improved the neurological scores and ameliorated cerebral vasospasm. Moreover, MN-08 also alleviated cerebral vasospasm in a cisterna magna single-injection model in rabbits. MN-08 attenuated neural cell apoptosis in both rat and rabbit models of SAH. Importantly, the therapeutic benefit of MN-08 was greater than that of memantine. CONCLUSION AND IMPLICATIONS MN-08 has neuroprotective potential and can ameliorate vasospasm in experimental SAH models.
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Affiliation(s)
- Fangcheng Luo
- Institute of New Drug Research and Guangzhou Key Laboratory of Innovative Chemical Drug Research in Cardio-cerebrovascular Diseases, Jinan University College of Pharmacy, Guangzhou, China
| | - Liangmiao Wu
- Institute of New Drug Research and Guangzhou Key Laboratory of Innovative Chemical Drug Research in Cardio-cerebrovascular Diseases, Jinan University College of Pharmacy, Guangzhou, China
| | - Zhixiang Zhang
- Institute of New Drug Research and Guangzhou Key Laboratory of Innovative Chemical Drug Research in Cardio-cerebrovascular Diseases, Jinan University College of Pharmacy, Guangzhou, China
| | - Zeyu Zhu
- Institute of New Drug Research and Guangzhou Key Laboratory of Innovative Chemical Drug Research in Cardio-cerebrovascular Diseases, Jinan University College of Pharmacy, Guangzhou, China
| | - Zheng Liu
- Institute of New Drug Research and Guangzhou Key Laboratory of Innovative Chemical Drug Research in Cardio-cerebrovascular Diseases, Jinan University College of Pharmacy, Guangzhou, China
| | - Baojian Guo
- Institute of New Drug Research and Guangzhou Key Laboratory of Innovative Chemical Drug Research in Cardio-cerebrovascular Diseases, Jinan University College of Pharmacy, Guangzhou, China
| | - Ning Li
- Institute of New Drug Research and Guangzhou Key Laboratory of Innovative Chemical Drug Research in Cardio-cerebrovascular Diseases, Jinan University College of Pharmacy, Guangzhou, China
| | - Jun Ju
- School of Chemical Biology and Biotechnology, Peking University Shenzhen Graduate School, Shenzhen, China
| | - Qiang Zhou
- School of Chemical Biology and Biotechnology, Peking University Shenzhen Graduate School, Shenzhen, China
| | - Shupeng Li
- School of Chemical Biology and Biotechnology, Peking University Shenzhen Graduate School, Shenzhen, China
| | - Xifei Yang
- Key Laboratory of Modern Toxicology of Shenzhen, Center for Disease Control and Prevention, Shenzhen, China
| | - Shinghung Mak
- State Key Laboratory of Chinese Medicine and Molecular Pharmacology (Incubation), The Hong Kong Polytechnic University Shenzhen Research Institute, Shenzhen, China.,Department of Applied Biology and Chemical Technology, Institute of Modern Chinese Medicine, The Hong Kong Polytechnic University, Hung Hom, Hong Kong, China
| | - Yifan Han
- State Key Laboratory of Chinese Medicine and Molecular Pharmacology (Incubation), The Hong Kong Polytechnic University Shenzhen Research Institute, Shenzhen, China.,Department of Applied Biology and Chemical Technology, Institute of Modern Chinese Medicine, The Hong Kong Polytechnic University, Hung Hom, Hong Kong, China
| | - Yewei Sun
- Institute of New Drug Research and Guangzhou Key Laboratory of Innovative Chemical Drug Research in Cardio-cerebrovascular Diseases, Jinan University College of Pharmacy, Guangzhou, China
| | - Yuqiang Wang
- Institute of New Drug Research and Guangzhou Key Laboratory of Innovative Chemical Drug Research in Cardio-cerebrovascular Diseases, Jinan University College of Pharmacy, Guangzhou, China
| | - Gaoxiao Zhang
- Institute of New Drug Research and Guangzhou Key Laboratory of Innovative Chemical Drug Research in Cardio-cerebrovascular Diseases, Jinan University College of Pharmacy, Guangzhou, China
| | - Zaijun Zhang
- Institute of New Drug Research and Guangzhou Key Laboratory of Innovative Chemical Drug Research in Cardio-cerebrovascular Diseases, Jinan University College of Pharmacy, Guangzhou, China.,International Cooperative Laboratory of Traditional Chinese Medicine Modernization and Innovative Drug Development of Chinese Ministry of Education (MOE), Jinan University College of Pharmacy, Guangzhou, China
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146
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Lin S, Cheng H, Zhang S, Ye C, Pan X, Tao A, Xu X, Qu J, Liang Y. Parapapillary Choroidal Microvasculature Dropout Is Associated With the Decrease in Retinal Nerve Fiber Layer Thickness: A Prospective Study. Invest Ophthalmol Vis Sci 2019; 60:838-842. [PMID: 30811547 DOI: 10.1167/iovs.18-26115] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose To explore the correlation between longitudinal changes of peripapillary retinal nerve fiber layer (RNFL) thickness and the presence of parapapillary choroidal microvasculature dropout (MvD). Methods This is a longitudinal cohort study. All patients with normal-tension glaucoma (NTG) were recruited from the Wenzhou Glaucoma Progression Study. The presence of MvD was determined using optical coherence tomography (OCT) angiography and the RNFL thickness was evaluated by spectral-domain OCT. All assessments were performed both at baseline and at every 3-month follow-up for at least 18 months. Results Seventy-one eyes were included. The presence of MvD was observed in 23 NTG eyes (32.4%). Eyes with MvD had a thinner RNFL (68.8 ± 9.6 vs. 76.2 ± 16.7 μm, P = 0.016) and a faster rate of RNFL loss (-1.2 ± 1.5 vs. -0.4 ± 1.4 μm/y, P = 0.036) compared with those without MvD. In a univariate analysis of rates of RNFL loss, the presence of MvD at baseline (β = -0.83 ± 0.38, P = 0.033) was significantly associated with progressive RNFL loss. After adjusting for age, female sex, mean follow-up IOP, axial length, central corneal thickness, and mean deviation, the presence of MvD at baseline (β = -0.85 ± 0.41, P = 0.041) was significantly associated with faster rates of RNFL loss in the multivariate analysis. Conclusions There is a significant correlation between the presence of MvD and decrease in RNFL thickness in NTG patients. Our study further supported that the presence of MvD is a predictor of longitudinal RNFL damage in glaucoma.
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Affiliation(s)
- Sigeng Lin
- The Eye Hospital, School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, China
| | - Huanhuan Cheng
- The Eye Hospital, School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, China
| | - Shaodan Zhang
- The Eye Hospital, School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, China
| | - Cong Ye
- The Eye Hospital, School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, China
| | - Xiafei Pan
- The Eye Hospital, School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, China
| | - Aizhu Tao
- The Eye Hospital, School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, China
| | - Xiang Xu
- The Eye Hospital, School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, China
| | - Jia Qu
- The Eye Hospital, School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, China
| | - Yuanbo Liang
- The Eye Hospital, School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, China
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147
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Stoll G, Nieswandt B. Thrombo-inflammation in acute ischaemic stroke — implications for treatment. Nat Rev Neurol 2019; 15:473-481. [DOI: 10.1038/s41582-019-0221-1] [Citation(s) in RCA: 120] [Impact Index Per Article: 24.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/15/2019] [Indexed: 01/17/2023]
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148
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Chaigneau E, Roche M, Charpak S. Unbiased Analysis Method for Measurement of Red Blood Cell Size and Velocity With Laser Scanning Microscopy. Front Neurosci 2019; 13:644. [PMID: 31316334 PMCID: PMC6610068 DOI: 10.3389/fnins.2019.00644] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2019] [Accepted: 06/05/2019] [Indexed: 12/28/2022] Open
Abstract
Two-photon laser scanning microscopy is widely used to measure blood hemodynamics in brain blood vessels. Still, the algorithms used so far to extract red blood cell (RBC) size and velocity from line-scan acquisitions have ignored the extent to which scanning speed influences the measurements. Here, we used a theoretical approach that takes into account the velocity and direction of both scanning mirrors and RBCs during acquisition to provide an algorithm that measures the real RBC size and velocity. We validate our approach in brain vessels of anesthetized mice, and demonstrate that it corrects online measurement errors that can reach several 10s of percent as well as data previously acquired. To conclude, our analysis allows unbiased comparisons of blood hemodynamic parameters from brain capillaries and large vessels in control and pathological animal models.
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Affiliation(s)
| | | | - Serge Charpak
- INSERM U1128, Laboratory of Neurophysiology and New Microscopy, Université Paris Descartes, Paris, France
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149
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Direct wavefront sensing enables functional imaging of infragranular axons and spines. Nat Methods 2019; 16:615-618. [PMID: 31209383 DOI: 10.1038/s41592-019-0434-7] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2018] [Accepted: 04/29/2019] [Indexed: 11/09/2022]
Abstract
We advance two-photon microscopy for near-diffraction-limited imaging up to 850 µm below the pia in awake mice. Our approach combines direct wavefront sensing of light from a guidestar (formed by descanned fluorescence from Cy5.5-conjugated dextran in brain microvessels) with adaptive optics to compensate for tissue-induced aberrations in the wavefront. We achieve high signal-to-noise ratios in recordings of glutamate release from thalamocortical axons and calcium transients in spines of layer 5b basal dendrites during active tactile sensing.
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150
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Evans TA, Barkauskas DS, Silver J. Intravital imaging of immune cells and their interactions with other cell types in the spinal cord: Experiments with multicolored moving cells. Exp Neurol 2019; 320:112972. [PMID: 31234058 DOI: 10.1016/j.expneurol.2019.112972] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Revised: 05/25/2019] [Accepted: 06/04/2019] [Indexed: 12/25/2022]
Abstract
Intravital imaging of the immune system is a powerful technique for studying biology of the immune response in the spinal cord using a variety of disease models ranging from traumatic injury to autoimmune disorders. Here, we will discuss specific technical aspects as well as many intriguing biological phenomena that have been revealed with the use of intravital imaging for investigation of the immune system in the spinal cord. We will discuss surgical techniques for exposing and stabilizing the spine that are critical for obtaining images, visualizing immune and CNS cells with genetically expressed fluorescent proteins, fluorescent labeling techniques and briefly discuss some of the challenges of image analysis.
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Affiliation(s)
- Teresa A Evans
- Department of Pediatrics, Stanford University, Stanford, CA, USA.
| | | | - Jerry Silver
- Department of Neurosciences, Case Western Reserve University, Cleveland, OH, USA
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