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Kuo DP, Chen YC, Cheng SJ, Hsieh KLC, Ou CY, Li YT, Chen CY. Ischemia-reperfusion injury in a salvaged penumbra: Longitudinal high-tesla perfusion magnetic resonance imaging in a rat model. Magn Reson Imaging 2024; 112:47-53. [PMID: 38909765 DOI: 10.1016/j.mri.2024.06.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2024] [Revised: 05/23/2024] [Accepted: 06/20/2024] [Indexed: 06/25/2024]
Abstract
INTRODUCTION Although ischemia-reperfusion (I/R) injury varies between cortical and subcortical regions, its effects on specific regions remain unclear. In this study, we used various magnetic resonance imaging (MRI) techniques to examine the spatiotemporal dynamics of I/R injury within the salvaged ischemic penumbra (IP) and reperfused ischemic core (IC) of a rodent model, with the aim of enhancing therapeutic strategies by elucidating these dynamics. MATERIALS AND METHODS A total of 17 Sprague-Dawley rats were subjected to 1 h of transient middle cerebral artery occlusion with a suture model. MRI, including diffusion tensor imaging (DTI), T2-weighted imaging, perfusion-weighted imaging, and T1 mapping, was conducted at multiple time points for up to 5 days during the I/R phases. The spatiotemporal dynamics of blood-brain barrier (BBB) modifications were characterized through changes in T1 within the IP and IC regions and compared with mean diffusivity (MD), T2, and cerebral blood flow. RESULTS During the I/R phases, the MD of the IC initially decreased, normalized after recanalization, decreased again at 24 h, and peaked on day 5. By contrast, the IP remained relatively stable. Both the IP and IC exhibited hyperperfusion, with the IP reaching its peak at 24 h, followed by resolution, whereas hyperperfusion was maintained in the IC until day 5. Despite hyperperfusion, the IP maintained an intact BBB, whereas the IC experienced persistent BBB leakage. At 24 h, the IC exhibited an increase in the T2 signal, corresponding to regions exhibiting BBB disruption at 5 days. CONCLUSIONS Hyperperfusion and BBB impairment have distinct patterns in the IP and IC. Quantitative T1 mapping may serve as a supplementary tool for the early detection of malignant hyperemia accompanied by BBB leakage, aiding in precise interventions after recanalization. These findings underscore the value of MRI markers in monitoring ischemia-specific regions and customizing therapeutic strategies to improve patient outcomes.
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Affiliation(s)
- Duen-Pang Kuo
- Department of Medical Imaging, Taipei Medical University Hospital, Taipei, Taiwan; Translational Imaging Research Center, Taipei Medical University Hospital, Taipei, Taiwan; Department of Radiology, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan
| | - Yung-Chieh Chen
- Department of Medical Imaging, Taipei Medical University Hospital, Taipei, Taiwan; Translational Imaging Research Center, Taipei Medical University Hospital, Taipei, Taiwan; Department of Radiology, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan
| | - Sho-Jen Cheng
- Department of Medical Imaging, Taipei Medical University Hospital, Taipei, Taiwan; Translational Imaging Research Center, Taipei Medical University Hospital, Taipei, Taiwan
| | - Kevin Li-Chun Hsieh
- Department of Medical Imaging, Taipei Medical University Hospital, Taipei, Taiwan; Translational Imaging Research Center, Taipei Medical University Hospital, Taipei, Taiwan; Department of Radiology, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan
| | - Chen-Yin Ou
- Translational Imaging Research Center, Taipei Medical University Hospital, Taipei, Taiwan
| | - Yi-Tien Li
- Translational Imaging Research Center, Taipei Medical University Hospital, Taipei, Taiwan; Research Center for Neuroscience, Taipei Medical University, Taipei, Taiwan; Ph.D. Program in Medical Neuroscience, College of Medical Science and Technology, Taipei Medical University, Taipei, Taiwan.
| | - Cheng-Yu Chen
- Department of Medical Imaging, Taipei Medical University Hospital, Taipei, Taiwan; Translational Imaging Research Center, Taipei Medical University Hospital, Taipei, Taiwan; Research Center for Artificial Intelligence in Medicine, Taipei Medical University, Taipei, Taiwan; Department of Radiology, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan; Department of Radiology, National Defense Medical Center, Taipei, Taiwan
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Conti E, Carlini N, Piccardi B, Allegra Mascaro AL, Pavone FS. Photothrombotic Middle Cerebral Artery Occlusion in Mice: A Novel Model of Ischemic Stroke. eNeuro 2023; 10:ENEURO.0244-22.2022. [PMID: 36650068 PMCID: PMC9910575 DOI: 10.1523/eneuro.0244-22.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Revised: 10/25/2022] [Accepted: 11/06/2022] [Indexed: 01/19/2023] Open
Abstract
Stroke is one of the main causes of death and disability worldwide. Over the past decades, several animal models of focal cerebral ischemia have been developed allowing to investigate pathophysiological mechanisms underlying stroke progression. Despite intense preclinical research efforts, the need for noninvasive mouse models of vascular occlusion targeting the middle cerebral artery yet avoiding mechanical intervention is still pressing. Here, by applying the photothrombotic stroke model to the distal branch of the middle cerebral artery, we developed a novel strategy to induce a targeted occlusion of a large blood vessel in mice. This approach induces unilateral damage encompassing most of the dorsal cortex from the motor up to the visual regions 1 week after stroke. Pronounced limb dystonia one day after the damage is partially recovered after one week. Furthermore, we observe the insurgence of blood vessel leakage and edema formation in the peri-infarct area. Finally, this model elicits a notable inflammatory response revealed as a strong increase in astrocyte density and morphologic complexity in the perilesional region of the cortex compared with both other regions of the ipsilesional and contralesional hemispheres, and in sham-operated mice. To conclude, the stroke model we developed induces in mice the light-mediated occlusion of one of the main targets of human ischemic stroke, the middle cerebral artery, free from the limitations of commonly used preclinical models.
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Affiliation(s)
- Emilia Conti
- Neuroscience Institute, National Research Council, 56124 Pisa, Italy
- European Laboratory for Non-Linear Spectroscopy, 50019 Sesto Fiorentino, Italy
- Translational Research on Stroke (TREES) Working Group, Florence, Italy
| | - Noemi Carlini
- Neuroscience Institute, National Research Council, 56124 Pisa, Italy
- European Laboratory for Non-Linear Spectroscopy, 50019 Sesto Fiorentino, Italy
| | - Benedetta Piccardi
- Neurofarba Department, University of Florence, 50139 Florence, Italy
- Translational Research on Stroke (TREES) Working Group, Florence, Italy
| | - Anna Letizia Allegra Mascaro
- Neuroscience Institute, National Research Council, 56124 Pisa, Italy
- European Laboratory for Non-Linear Spectroscopy, 50019 Sesto Fiorentino, Italy
- Translational Research on Stroke (TREES) Working Group, Florence, Italy
| | - Francesco Saverio Pavone
- European Laboratory for Non-Linear Spectroscopy, 50019 Sesto Fiorentino, Italy
- Department of Physics and Astronomy, University of Florence, 50019 Sesto Fiorentino, Italy
- National Institute of Optics, National Research Council, 50019 Sesto Fiorentino, Italy
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Optimising the photothrombotic model of stroke in the C57BI/6 and FVB/N strains of mouse. Sci Rep 2022; 12:7598. [PMID: 35534531 PMCID: PMC9085761 DOI: 10.1038/s41598-022-11793-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2021] [Accepted: 04/08/2022] [Indexed: 11/17/2022] Open
Abstract
The photothrombotic stroke model relies on the interaction between photosensitive-dye and light for clot formation. Interestingly, the relationship between the length of light exposure and stroke-outcome has never been examined. This model has yet to be established in the FVB/N strain, even though stroke-outcomes are strain-specific. Therefore, this study aimed to examine the effect of different lengths of light exposure in two strains of mice on photothrombotic stroke. Male FVB/N and C57Bl/6 mice were subjected to stroke using 15, 18, or 20-min light exposure. Mice underwent functional testing for up to 7 days. Infarct volume was assessed with thionin staining, and cellular responses to injury analysed via immunofluorescence at 7-days post-stroke. Blood brain barrier (BBB) breakdown was assessed using Evans blue dye at 4.5-h post-stroke. Increasing light exposure from 15 to 20-min increased infarct volume but not functional deficit. Interestingly, there were strain-specific differences in functional outcomes, with FVB/N mice having less deficit on the hanging wire test than C57BI/6 after 15-min of light exposure. The opposite was seen in the adhesive removal test. There was no difference in the number of neurons, astrocytes, microglia, macrophages, and T cells between the strains, despite FVB/N mice demonstrating greater BBB breakdown and an enlarged spleen post-stroke. Increasing light exposure systematically increases infarct volume but does not worsen functional outcomes. FVB/N and C57Bl/6 mice exhibit subtle differences in functional outcomes post stroke, which highlights the need to choose tests which are appropriate for the mouse strain being used.
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Nishihara H, Engelhardt B. Brain Barriers and Multiple Sclerosis: Novel Treatment Approaches from a Brain Barriers Perspective. Handb Exp Pharmacol 2022; 273:295-329. [PMID: 33237504 DOI: 10.1007/164_2020_407] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Multiple sclerosis (MS) is considered a prototypic organ specific autoimmune disease targeting the central nervous system (CNS). Blood-brain barrier (BBB) breakdown and enhanced immune cell infiltration into the CNS parenchyma are early hallmarks of CNS lesion formation. Therapeutic targeting of immune cell trafficking across the BBB has proven a successful therapy for the treatment of MS, but comes with side effects and is no longer effective once patients have entered the progressive phase of the disease. Beyond the endothelial BBB, epithelial and glial brain barriers establish compartments in the CNS that differ in their accessibility to the immune system. There is increasing evidence that brain barrier abnormalities persist during the progressive stages of MS. Here, we summarize the role of endothelial, epithelial, and glial brain barriers in maintaining CNS immune privilege and our current knowledge on how impairment of these barriers contributes to MS pathogenesis. We discuss how therapeutic stabilization of brain barriers integrity may improve the safety of current therapeutic regimes for treating MS. This may also allow for the development of entirely novel therapeutic approaches aiming to restore brain barriers integrity and thus CNS homeostasis, which may be specifically beneficial for the treatment of progressive MS.
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Correlation Tensor MRI deciphers underlying kurtosis sources in stroke. Neuroimage 2021; 247:118833. [PMID: 34929382 DOI: 10.1016/j.neuroimage.2021.118833] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Revised: 12/15/2021] [Accepted: 12/16/2021] [Indexed: 02/06/2023] Open
Abstract
Noninvasively detecting and characterizing modulations in cellular scale micro-architecture remains a desideratum for contemporary neuroimaging. Diffusion MRI (dMRI) has become the mainstay methodology for probing microstructure, and, in ischemia, its contrasts have revolutionized stroke management. Diffusion kurtosis imaging (DKI) has been shown to significantly enhance the sensitivity of stroke detection compared to its diffusion tensor imaging (DTI) counterparts. However, the interpretation of DKI remains ambiguous as its contrast may arise from competing kurtosis sources related to the anisotropy of tissue components, diffusivity variance across components, and microscopic kurtosis (e.g., arising from cross-sectional variance, structural disorder, and restriction). Resolving these sources may be fundamental for developing more specific imaging techniques for stroke management, prognosis, and understanding its pathophysiology. In this study, we apply Correlation Tensor MRI (CTI) - a double diffusion encoding (DDE) methodology recently introduced for deciphering kurtosis sources based on the unique information captured in DDE's diffusion correlation tensors - to investigate the underpinnings of kurtosis measurements in acute ischemic lesions. Simulations for the different kurtosis sources revealed specific signatures for cross-sectional variance (representing neurite beading), edema, and cell swelling. Ex vivo CTI experiments at 16.4 T were then performed in an experimental photothrombotic stroke model 3 h post-stroke (N = 10), and successfully separated anisotropic, isotropic, and microscopic non-Gaussian diffusion sources in the ischemic lesions. Each of these kurtosis sources provided unique contrasts in the stroked area. Particularly, microscopic kurtosis was shown to be a primary "driver" of total kurtosis upon ischemia; its large increases, coupled with decreases in anisotropic kurtosis, are consistent with the expected elevation in cross-sectional variance, likely linked to beading effects in small objects such as neurites. In vivo experiments at 9.4 T at the same time point (3 h post ischemia, N = 5) demonstrated the stability and relevance of the findings and showed that fixation is not a dominant confounder in our findings. In future studies, the different CTI contrasts may be useful to address current limitations of stroke imaging, e.g., penumbra characterization, distinguishing lesion progression form tissue recovery, and elucidating pathophysiological correlates.
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Conti E, Piccardi B, Sodero A, Tudisco L, Lombardo I, Fainardi E, Nencini P, Sarti C, Allegra Mascaro AL, Baldereschi M. Translational Stroke Research Review: Using the Mouse to Model Human Futile Recanalization and Reperfusion Injury in Ischemic Brain Tissue. Cells 2021; 10:3308. [PMID: 34943816 PMCID: PMC8699609 DOI: 10.3390/cells10123308] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Revised: 11/17/2021] [Accepted: 11/19/2021] [Indexed: 12/20/2022] Open
Abstract
The approach to reperfusion therapies in stroke patients is rapidly evolving, but there is still no explanation why a substantial proportion of patients have a poor clinical prognosis despite successful flow restoration. This issue of futile recanalization is explained here by three clinical cases, which, despite complete recanalization, have very different outcomes. Preclinical research is particularly suited to characterize the highly dynamic changes in acute ischemic stroke and identify potential treatment targets useful for clinical translation. This review surveys the efforts taken so far to achieve mouse models capable of investigating the neurovascular underpinnings of futile recanalization. We highlight the translational potential of targeting tissue reperfusion in fully recanalized mouse models and of investigating the underlying pathophysiological mechanisms from subcellular to tissue scale. We suggest that stroke preclinical research should increasingly drive forward a continuous and circular dialogue with clinical research. When the preclinical and the clinical stroke research are consistent, translational success will follow.
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Affiliation(s)
- Emilia Conti
- Neuroscience Institute, National Research Council, Via G. Moruzzi 1, 56124 Pisa, Italy; (E.C.); (A.L.A.M.)
- European Laboratory for Non-Linear Spectroscopy, Via Nello Carrara 1, 50019 Sesto Fiorentino, Italy
| | - Benedetta Piccardi
- Neurofarba Department, University of Florence, Via G. Pieraccini 6, 50139 Florence, Italy; (A.S.); (L.T.); (C.S.)
| | - Alessandro Sodero
- Neurofarba Department, University of Florence, Via G. Pieraccini 6, 50139 Florence, Italy; (A.S.); (L.T.); (C.S.)
| | - Laura Tudisco
- Neurofarba Department, University of Florence, Via G. Pieraccini 6, 50139 Florence, Italy; (A.S.); (L.T.); (C.S.)
| | - Ivano Lombardo
- Department of Biomedical, Experimental and Clinical Sciences, University of Florence, Viale Morgagni 50, 50134 Florence, Italy; (I.L.); (E.F.)
| | - Enrico Fainardi
- Department of Biomedical, Experimental and Clinical Sciences, University of Florence, Viale Morgagni 50, 50134 Florence, Italy; (I.L.); (E.F.)
| | - Patrizia Nencini
- Stroke Unit, Careggi University Hospital, Largo Brambilla 3, 50134 Florence, Italy;
| | - Cristina Sarti
- Neurofarba Department, University of Florence, Via G. Pieraccini 6, 50139 Florence, Italy; (A.S.); (L.T.); (C.S.)
| | - Anna Letizia Allegra Mascaro
- Neuroscience Institute, National Research Council, Via G. Moruzzi 1, 56124 Pisa, Italy; (E.C.); (A.L.A.M.)
- European Laboratory for Non-Linear Spectroscopy, Via Nello Carrara 1, 50019 Sesto Fiorentino, Italy
| | - Marzia Baldereschi
- Neuroscience Institute, National Research Council, Via Madonna del Piano 10, 50019 Sesto Fiorentino, Italy;
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Schoknecht K, Kikhia M, Lemale CL, Liotta A, Lublinsky S, Mueller S, Boehm-Sturm P, Friedman A, Dreier JP. The role of spreading depolarizations and electrographic seizures in early injury progression of the rat photothrombosis stroke model. J Cereb Blood Flow Metab 2021; 41:413-430. [PMID: 32241203 PMCID: PMC7812510 DOI: 10.1177/0271678x20915801] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Spreading depolarization (SD) and seizures are pathophysiological events associated with cerebral ischemia. Here, we investigated their role for injury progression in the cerebral cortex. Cerebral ischemia was induced in anesthetized male Wistar rats using the photothrombosis (PT) stroke model. SD and spontaneous neuronal activity were recorded in the presence of either urethane or ketamine/xylazine anesthesia. Blood-brain barrier (BBB) permeability, cerebral perfusion, and cellular damage were assessed through a cranial window and repeated intravenous injection of fluorescein sodium salt and propidium iodide until 4 h after PT. Neuronal injury and early lesion volume were quantified by stereological cell counting and manual and automated assessment of ex vivo T2-weighted magnetic resonance imaging. Onset SDs originated at the thrombotic core and invaded neighboring cortex, whereas delayed SDs often showed opposite propagation patterns. Seizure induction by 4-aminopyridine caused no increase in lesion volume or neuronal injury in urethane-anesthetized animals. Ketamine/xylazine anesthesia was associated with a lower number of onset SDs, reduced lesion volume, and neuronal injury despite a longer duration of seizures. BBB permeability increase inversely correlated with the number of SDs at 3 and 4 h after PT. Our results provide further evidence that ketamine may counteract the early progression of ischemic injury.
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Affiliation(s)
- Karl Schoknecht
- Center for Stroke Research Berlin (CSB), Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany.,Department of Neurology, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany.,Department of Experimental Neurology, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany.,Neuroscience Research Center, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany.,Institute for Neurophysiology, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany.,Carl-Ludwig-Institute for Physiology, Medical Faculty, University of Leipzig, Leipzig, Germany
| | - Majed Kikhia
- Department of Experimental Neurology, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany.,Einstein Center for Neurosciences Berlin, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Coline L Lemale
- Center for Stroke Research Berlin (CSB), Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany.,Department of Experimental Neurology, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Agustin Liotta
- Neuroscience Research Center, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany.,Institute for Neurophysiology, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany.,Department of Anesthesiology, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Svetlana Lublinsky
- Departments of Physiology & Cell Biology, Cognitive & Brain Sciences, the Zlotowski Center for Neuroscience, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Susanne Mueller
- Center for Stroke Research Berlin (CSB), Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany.,Department of Experimental Neurology, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany.,NeuroCure Cluster of Excellence and Charité Core Facility 7T Experimental MRIs, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Philipp Boehm-Sturm
- Center for Stroke Research Berlin (CSB), Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany.,Department of Experimental Neurology, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany.,NeuroCure Cluster of Excellence and Charité Core Facility 7T Experimental MRIs, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Alon Friedman
- Departments of Physiology & Cell Biology, Cognitive & Brain Sciences, the Zlotowski Center for Neuroscience, Ben-Gurion University of the Negev, Beer-Sheva, Israel.,Department of Medical Neuroscience, Dalhousie University, Halifax, Canada
| | - Jens P Dreier
- Center for Stroke Research Berlin (CSB), Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany.,Department of Neurology, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany.,Department of Experimental Neurology, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany.,Einstein Center for Neurosciences Berlin, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany.,Bernstein Center for Computational Neuroscience Berlin, Humboldt-Universität zu Berlin, Germany
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Schuhmann MK, Stoll G, Papp L, Bohr A, Volkmann J, Fluri F. Electrical Stimulation of the Mesencephalic Locomotor Region Has No Impact on Blood-Brain Barrier Alterations after Cerebral Photothrombosis in Rats. Int J Mol Sci 2019; 20:ijms20164036. [PMID: 31430854 PMCID: PMC6719928 DOI: 10.3390/ijms20164036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2019] [Revised: 08/16/2019] [Accepted: 08/16/2019] [Indexed: 11/16/2022] Open
Abstract
Blood–brain barrier (BBB) disruption is a critical event after ischemic stroke, which results in edema formation and hemorrhagic transformation of infarcted tissue. BBB dysfunction following stroke is partly mediated by proinflammatory agents. We recently have shown that high frequency stimulation of the mesencephalic locomotor region (MLR-HFS) exerts an antiapoptotic and anti-inflammatory effect in the border zone of cerebral photothrombotic stroke in rats. Whether MLR-HFS also has an impact on BBB dysfunction in the early stage of stroke is unknown. In this study, rats were subjected to photothrombotic stroke of the sensorimotor cortex and implantation of a stimulating microelectrode into the ipsilesional MLR. Thereafter, either HFS or sham stimulation of the MLR was applied for 24 h. After scarifying the rats, BBB disruption was assessed by determining albumin extravasation and tight junction integrity (claudin 3, claudin 5, and occludin) using Western blot analyses and immunohistochemistry. In addition, by applying zymography, expression of pro-metalloproteinase-9 (pro-MMP-9) was analyzed. No differences were found regarding infarct size and BBB dysfunction between stimulated and unstimulated animals 24 h after induction of stroke. Our results indicate that MLR-HFS neither improves nor worsens the damaged BBB after stroke. Attenuating cytokines/chemokines in the perilesional area, as mediated by MLR-HFS, tend to play a less significant role in preventing the BBB integrity.
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Affiliation(s)
- Michael K Schuhmann
- Department of Neurology, University Hospital of Würzburg, 97080 Würzburg, Germany
| | - Guido Stoll
- Department of Neurology, University Hospital of Würzburg, 97080 Würzburg, Germany
| | - Lena Papp
- Department of Neurology, University Hospital of Würzburg, 97080 Würzburg, Germany
| | - Arne Bohr
- Department of Neurology, University Hospital of Würzburg, 97080 Würzburg, Germany
| | - Jens Volkmann
- Department of Neurology, University Hospital of Würzburg, 97080 Würzburg, Germany
| | - Felix Fluri
- Department of Neurology, University Hospital of Würzburg, 97080 Würzburg, Germany.
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Sadeghian H, Lacoste B, Qin T, Toussay X, Rosa R, Oka F, Chung DY, Takizawa T, Gu C, Ayata C. Spreading depolarizations trigger caveolin-1-dependent endothelial transcytosis. Ann Neurol 2018; 84:409-423. [PMID: 30014540 PMCID: PMC6153037 DOI: 10.1002/ana.25298] [Citation(s) in RCA: 72] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2018] [Revised: 07/08/2018] [Accepted: 07/11/2018] [Indexed: 12/24/2022]
Abstract
OBJECTIVE Cortical spreading depolarizations (CSDs) are intense and ubiquitous depolarization waves relevant for the pathophysiology of migraine and brain injury. CSDs disrupt the blood-brain barrier (BBB), but the mechanisms are unknown. METHODS A total of six CSDs were evoked over 1 hour by topical application of 300 mM of KCl or optogenetically with 470 nm (blue) LED over the right hemisphere in anesthetized mice (C57BL/6 J wild type, Thy1-ChR2-YFP line 18, and cav-1-/- ). BBB disruption was assessed by Evans blue (2% EB, 3 ml/kg, intra-arterial) or dextran (200 mg/kg, fluorescein, 70,000 MW, intra-arterial) extravasation in parietotemporal cortex at 3 to 24 hours after CSD. Endothelial cell ultrastructure was examined using transmission electron microscopy 0 to 24 hours after the same CSD protocol in order to assess vesicular trafficking, endothelial tight junctions, and pericyte integrity. Mice were treated with vehicle, isoform nonselective rho-associated kinase (ROCK) inhibitor fasudil (10 mg/kg, intraperitoneally 30 minutes before CSD), or ROCK-2 selective inhibitor KD025 (200 mg/kg, per oral twice-daily for 5 doses before CSD). RESULTS We show that CSD-induced BBB opening to water and large molecules is mediated by increased endothelial transcytosis starting between 3 and 6 hours and lasting approximately 24 hours. Endothelial tight junctions, pericytes, and basement membrane remain preserved after CSDs. Moreover, we show that CSD-induced BBB disruption is exclusively caveolin-1-dependent and requires rho-kinase 2 activity. Importantly, hyperoxia failed to prevent CSD-induced BBB breakdown, suggesting that the latter is independent of tissue hypoxia. INTERPRETATION Our data elucidate the mechanisms by which CSDs lead to transient BBB disruption, with diagnostic and therapeutic implications for migraine and brain injury.
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Affiliation(s)
- Homa Sadeghian
- Neurovascular Research Laboratory, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA
| | - Baptiste Lacoste
- The Ottawa Hospital Research Institute, Neuroscience Program, Ottawa, ON, Canada
- Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, ON, Canada
- The University of Ottawa Brain and Mind Research Institute, Ottawa, ON, Canada
- Department of Neurobiology, Harvard Medical School, Boston, MA, USA
| | - Tao Qin
- Neurovascular Research Laboratory, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA
| | - Xavier Toussay
- The Ottawa Hospital Research Institute, Neuroscience Program, Ottawa, ON, Canada
| | - Roberto Rosa
- Department of Neurobiology, Harvard Medical School, Boston, MA, USA
| | - Fumiaki Oka
- Neurovascular Research Laboratory, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA
| | - David Y Chung
- Neurovascular Research Laboratory, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA
| | - Tsubasa Takizawa
- Neurovascular Research Laboratory, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA
| | - Chenghua Gu
- Department of Neurobiology, Harvard Medical School, Boston, MA, USA
| | - Cenk Ayata
- Neurovascular Research Laboratory, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA
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10
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Hoffmann A, Dege T, Kunze R, Ernst AS, Lorenz H, Böhler LI, Korff T, Marti HH, Heiland S, Bendszus M, Helluy X, Pham M. Early Blood-Brain Barrier Disruption in Ischemic Stroke Initiates Multifocally Around Capillaries/Venules. Stroke 2018; 49:1479-1487. [PMID: 29760276 DOI: 10.1161/strokeaha.118.020927] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2017] [Revised: 03/29/2018] [Accepted: 04/10/2018] [Indexed: 02/07/2023]
Abstract
BACKGROUND AND PURPOSE Detection and localization of the early phase of blood-brain barrier disruption (BBBD) in vivo during cerebral ischemia/reperfusion injury remain a major challenge but may be a relevant outcome parameter in stroke. METHODS We studied early BBBD in mice after transient middle cerebral artery occlusion by multimodal, high-field (9.4T) in vivo magnetic resonance imaging, including the contrast agent gadofluorineM as an albumin-binding tracer. GadofluorineM contrast-enhanced magnetic resonance imaging was performed to determine BBBD at 2, 6, and 24 hours after reperfusion. BBBD was confirmed and localized along the microvascular tree by using fluorescent gadofluorineM and immunofluorescence stainings (cluster of differentiation 31, ephrin type-B receptor 4, alpha smooth muscle actin, ionized calcium binding adaptor molecule 1). RESULTS GadofluorineM contrast-enhanced magnetic resonance imaging revealed a multifocal spatial distribution of early BBBD and its close association with the microvasculature at a resolution of 40 μm. GadofluorineM leakage was closely associated with ephrin type-B receptor 4-positive but not alpha smooth muscle actin-positive vessels. The multifocal pattern of early BBBD (already at 2 hours after reperfusion) thus occurred in the distal capillary and venular microvascular bed. These multifocal zones showed distinct imaging signs indicative of early vasogenic edema. The total volume of multifocal early BBBD accurately predicted infarct size at 24 hours after reperfusion. CONCLUSIONS Early BBBD in focal cerebral ischemia initiates multifocally in the distal capillary and venular bed of the cerebral microvasculature. It is closely associated with perimicrovascular vasogenic edema and microglial activation and predicts the extent of final infarction.
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Affiliation(s)
- Angelika Hoffmann
- From the Department of Neuroradiology, Heidelberg University Hospital, Germany (A.H., T.D., S.H., M.B., M.P.)
| | - Tassilo Dege
- From the Department of Neuroradiology, Heidelberg University Hospital, Germany (A.H., T.D., S.H., M.B., M.P.)
| | - Reiner Kunze
- Institute of Physiology and Pathophysiology (R.K., A.-S.E., L.-I.B., T.K., H.H.M., X.H.)
| | - Anne-Sophie Ernst
- Institute of Physiology and Pathophysiology (R.K., A.-S.E., L.-I.B., T.K., H.H.M., X.H.).,Heidelberg Biosciences International Graduate School (A.-S.E., L.-I.B.)
| | - Holger Lorenz
- Center of Molecular Biology, University of Heidelberg (ZMBH) (H.L.), Heidelberg University, Germany
| | - Laura-Inés Böhler
- Institute of Physiology and Pathophysiology (R.K., A.-S.E., L.-I.B., T.K., H.H.M., X.H.).,Heidelberg Biosciences International Graduate School (A.-S.E., L.-I.B.)
| | - Thomas Korff
- Institute of Physiology and Pathophysiology (R.K., A.-S.E., L.-I.B., T.K., H.H.M., X.H.)
| | - Hugo H Marti
- Institute of Physiology and Pathophysiology (R.K., A.-S.E., L.-I.B., T.K., H.H.M., X.H.)
| | - Sabine Heiland
- From the Department of Neuroradiology, Heidelberg University Hospital, Germany (A.H., T.D., S.H., M.B., M.P.)
| | - Martin Bendszus
- From the Department of Neuroradiology, Heidelberg University Hospital, Germany (A.H., T.D., S.H., M.B., M.P.)
| | - Xavier Helluy
- Institute of Physiology and Pathophysiology (R.K., A.-S.E., L.-I.B., T.K., H.H.M., X.H.).,Department of Psychology, Institute of Cognitive Neuroscience, Biopsychology (X.H.).,Department of Neurophysiology (X.H.), Ruhr University Bochum, Germany
| | - Mirko Pham
- From the Department of Neuroradiology, Heidelberg University Hospital, Germany (A.H., T.D., S.H., M.B., M.P.).,Department of Neuroradiology, Würzburg University Hospital, Germany (M.P.)
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11
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Bell JS, Spencer JI, Yates RL, DeLuca GC. The cortical blood-brain barrier in multiple sclerosis: a gateway to progression? J Neurol 2018; 265:966-967. [PMID: 29442176 DOI: 10.1007/s00415-017-8727-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2017] [Revised: 12/27/2017] [Accepted: 12/29/2017] [Indexed: 02/06/2023]
Affiliation(s)
- Jack S Bell
- University of Oxford Medical School, Level 2 Academic Centre, John Radcliffe Hospital, Oxford, OX3 9DU, UK
| | - Jonathan I Spencer
- University of Oxford Medical School, Level 2 Academic Centre, John Radcliffe Hospital, Oxford, OX3 9DU, UK
| | - Richard L Yates
- University of Oxford Medical School, Level 2 Academic Centre, John Radcliffe Hospital, Oxford, OX3 9DU, UK
- Nuffield Department of Clinical Neurosciences, Level 1 West Wing, John Radcliffe Hospital, Oxford, OX3 9DU, UK
| | - Gabriele C DeLuca
- Nuffield Department of Clinical Neurosciences, Level 1 West Wing, John Radcliffe Hospital, Oxford, OX3 9DU, UK.
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12
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Abstract
The blood-brain interface (BBI) is the subject of a new named series at Brain, Behavior, and Immunity. It is timely to reflect on a number of advances in the field within the last ten years, which may lead to an increased understanding of human behaviour and a wide range of psychiatric and neurological conditions. We cover discoveries made in solute and cell trafficking, endothelial cell and pericyte biology, extracellular matrix and emerging tools, especially those which will enable study of the human BBI. We now recognize the central role of the BBI in a number of immunopsychiatric syndromes, including sickness behaviour, delirium, septic encephalopathy, cognitive side effects of cytokine-based therapies and the frank psychosis observed in neuronal surface antibody syndromes. In addition, we find ourselves interrogating and modulating the brain across the BBI, during diagnostic investigation and treatment of brain disease. The past ten years of BBI research have been exciting but there is more to come.
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13
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Dreier JP, Lemale CL, Kola V, Friedman A, Schoknecht K. Spreading depolarization is not an epiphenomenon but the principal mechanism of the cytotoxic edema in various gray matter structures of the brain during stroke. Neuropharmacology 2017; 134:189-207. [PMID: 28941738 DOI: 10.1016/j.neuropharm.2017.09.027] [Citation(s) in RCA: 128] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2017] [Revised: 09/16/2017] [Accepted: 09/19/2017] [Indexed: 12/15/2022]
Abstract
Spreading depolarization (SD) is a phenomenon of various cerebral gray matter structures that only occurs under pathological conditions. In the present paper, we summarize the evidence from several decades of research that SD and cytotoxic edema in these structures are largely overlapping terms. SD/cytotoxic edema is a toxic state that - albeit initially reversible - leads eventually to cellular death when it is persistent. Both hemorrhagic and ischemic stroke are among the most prominent causes of SD/cytotoxic edema. SD/cytotoxic edema is the principal mechanism that mediates neuronal death in these conditions. This applies to gray matter structures in both the ischemic core and the penumbra. SD/cytotoxic edema is often a single terminal event in the core whereas, in the penumbra, a cluster of repetitive prolonged SDs is typical. SD/cytotoxic edema also propagates widely into healthy surrounding tissue as short-lasting, relatively harmless events so that regional electrocorticographic monitoring affords even remote detection of ischemic zones. Ischemia cannot only cause SD/cytotoxic edema but it can also be its consequence through inverse neurovascular coupling. Under this condition, ischemia does not start simultaneously in different regions but spreads in the tissue driven by SD/cytotoxic edema-induced microvascular constriction (= spreading ischemia). Spreading ischemia prolongs SD/cytotoxic edema. Thus, it increases the likelihood for the transition from SD/cytotoxic edema into cellular death. Vasogenic edema is the other major type of cerebral edema with relevance to ischemic stroke. It results from opening of the blood-brain barrier. SD/cytotoxic edema and vasogenic edema are distinct processes with important mutual interactions. This article is part of the Special Issue entitled 'Cerebral Ischemia'.
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Affiliation(s)
- Jens P Dreier
- Center for Stroke Research Berlin, Charité-Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Berlin Institute of Health, Berlin, Germany; Departments of Neurology, Charité-Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Berlin Institute of Health, Berlin, Germany; Experimental Neurology, Charité-Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Berlin Institute of Health, Berlin, Germany.
| | - Coline L Lemale
- Center for Stroke Research Berlin, Charité-Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Berlin Institute of Health, Berlin, Germany
| | - Vasilis Kola
- Center for Stroke Research Berlin, Charité-Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Berlin Institute of Health, Berlin, Germany
| | - Alon Friedman
- Department of Physiology and Cell Biology, Zlotowski Center for Neuroscience, Ben-Gurion University of the Negev, Beer-Sheva, Israel; Department of Medical Neuroscience, Faculty of Medicine, Dalhousie University, Halifax, Canada
| | - Karl Schoknecht
- Center for Stroke Research Berlin, Charité-Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Berlin Institute of Health, Berlin, Germany; Experimental Neurology, Charité-Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Berlin Institute of Health, Berlin, Germany
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14
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Lippmann K, Kamintsky L, Kim SY, Lublinsky S, Prager O, Nichtweiss JF, Salar S, Kaufer D, Heinemann U, Friedman A. Epileptiform activity and spreading depolarization in the blood-brain barrier-disrupted peri-infarct hippocampus are associated with impaired GABAergic inhibition and synaptic plasticity. J Cereb Blood Flow Metab 2017; 37:1803-1819. [PMID: 27252228 PMCID: PMC5435286 DOI: 10.1177/0271678x16652631] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Peri-infarct opening of the blood-brain barrier may be associated with spreading depolarizations, seizures, and epileptogenesis as well as cognitive dysfunction. We aimed to investigate the mechanisms underlying neural network pathophysiology in the blood-brain barrier-dysfunctional hippocampus. Photothrombotic stroke within the rat neocortex was associated with increased intracranial pressure, vasogenic edema, and peri-ischemic blood-brain barrier dysfunction that included the ipsilateral hippocampus. Intrahippocampal recordings revealed electrographic seizures within the first week in two-thirds of animals, accompanied by a reduction in gamma and increase in theta frequency bands. Synaptic interactions were studied in parasagittal hippocampal slices at 24 h and seven days post-stroke. Field potential recordings in CA1 and CA3 uncovered multiple population spikes, epileptiform episodes, and spreading depolarizations at 24 h. Input-output analysis revealed that fEPSP-spike coupling was significantly enhanced at seven days. In addition, CA1 feedback and feedforward inhibition were diminished. Slices generating epileptiform activity at seven days revealed impaired bidirectional long-term plasticity following high and low-frequency stimulation protocols. Microarray and PCR data confirmed changes in expression of astrocyte-related genes and suggested downregulation in expression of GABAA-receptor subunits. We conclude that blood-brain barrier dysfunction in the peri-infarct hippocampus is associated with early disinhibition, hyperexcitability, and abnormal synaptic plasticity.
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Affiliation(s)
- Kristina Lippmann
- 1 Institute of Neurophysiology, Charité - University Medicine Berlin, Berlin, Germany.,2 Carl-Ludwig-Institute for Physiology, Leipzig University, Leipzig, Germany
| | - Lyn Kamintsky
- 3 Departments of Physiology and Cell Biology, Cognitive and Brain Sciences, The Zlotowski Center for Neuroscience, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Soo Young Kim
- 4 Helen Wills Neuroscience Institute and the Department of Integrative Biology, University of California, Berkeley, CA, USA
| | - Svetlana Lublinsky
- 3 Departments of Physiology and Cell Biology, Cognitive and Brain Sciences, The Zlotowski Center for Neuroscience, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Ofer Prager
- 3 Departments of Physiology and Cell Biology, Cognitive and Brain Sciences, The Zlotowski Center for Neuroscience, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | | | - Seda Salar
- 1 Institute of Neurophysiology, Charité - University Medicine Berlin, Berlin, Germany
| | - Daniela Kaufer
- 4 Helen Wills Neuroscience Institute and the Department of Integrative Biology, University of California, Berkeley, CA, USA
| | - Uwe Heinemann
- 5 Neuroscience Research Center, Berlin, Germany.,6 Excellence Cluster NeuroCure, Berlin, Germany
| | - Alon Friedman
- 3 Departments of Physiology and Cell Biology, Cognitive and Brain Sciences, The Zlotowski Center for Neuroscience, Ben-Gurion University of the Negev, Beer-Sheva, Israel.,7 Department of Medical Neuroscience, Faculty of Medicine, Dalhousie University, Halifax, Canada
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15
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Choi KH, Kim HS, Park MS, Lee EB, Lee JK, Kim JT, Kim JH, Lee MC, Lee HJ, Cho KH. Overexpression of caveolin-1 attenuates brain edema by inhibiting tight junction degradation. Oncotarget 2016; 7:67857-67867. [PMID: 27708218 PMCID: PMC5356525 DOI: 10.18632/oncotarget.12346] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2016] [Accepted: 09/25/2016] [Indexed: 02/07/2023] Open
Abstract
Cerebral edema from the disruption of the blood-brain barrier (BBB) after cerebral ischemia is a major cause of morbidity and mortality as well as a common event in patients with stroke. Caveolins (Cavs) are thought to regulate BBB functions. Here, we report for the first time that Cav-1 overexpression (OE) decreased brain edema from BBB disruption following ischemic insult. Edema volumes and Cav-1 expression levels were measured following photothrombosis and middle cerebral artery occlusion (MCAO). Endothelial cells that were transduced with a Cav-1 lentiviral expression vector were transplanted into rats. BBB permeability was quantified with Evans blue extravasation. Edema volume was determined from measures of the extravasation area, brain water content, and average fluorescence intensity after Cy5.5 injections. Tight junction (TJ) protein expression was measured with immunoblotting. Cav-1 expression levels and vasogenic brain edema correlated strongly after ischemic insult. Cav-1 expression and BBB disruption peaked 3 d after the MCAO. In addition, intravenous administration of endothelial cells expressing Cav-1 effectively increased the Cav-1 levels 3 d after the MCAO ischemic insult. Importantly, Cav-1 OE ameliorated the vasogenic edema by inhibiting the degradation of TJ protein expression in the acute phase of ischemic stroke. These results suggested that Cav-1 OE protected the integrity of the BBB mainly by preventing the degradation of TJ proteins in rats. These findings need to be confirmed in a clinical setting in human subjects.
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Affiliation(s)
- Kang-Ho Choi
- Department of Neurology, Chonnam National University Hwasun Hospital, Hwasun, Korea
- Department of Neurology, Chonnam National University Medical School, Gwangju, Korea
| | - Hyung-Seok Kim
- Department of Forensic Medicine, Chonnam National University Medical School, Gwangju, Korea
| | - Man-Seok Park
- Department of Neurology, Chonnam National University Medical School, Gwangju, Korea
| | - Eun-Bin Lee
- Department of Neurology, Chonnam National University Medical School, Gwangju, Korea
- Department of Forensic Medicine, Chonnam National University Medical School, Gwangju, Korea
| | - Jung-Kil Lee
- Department of Neurosurgery, Chonnam National University Medical School, Gwangju, Korea
| | - Joon-Tae Kim
- Department of Neurology, Chonnam National University Medical School, Gwangju, Korea
| | - Ja-Hae Kim
- Department of Nuclear Medicine, Chonnam National University Medical School, Gwangju, Korea
| | - Min-Cheol Lee
- Department of Pathology, Chonnam National University Medical School, Gwangju, Korea
| | - Hong-Joon Lee
- Medical Research Institute, Chungang University College of Medicine, Seoul, Korea
| | - Ki-Hyun Cho
- Department of Neurology, Chonnam National University Medical School, Gwangju, Korea
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16
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Meyer zu Horste G, Cordes S, Pfaff J, Mathys C, Mausberg AK, Bendszus M, Pham M, Hartung HP, Kieseier BC. Predicting the Response to Intravenous Immunoglobulins in an Animal Model of Chronic Neuritis. PLoS One 2016; 11:e0164099. [PMID: 27711247 PMCID: PMC5053527 DOI: 10.1371/journal.pone.0164099] [Citation(s) in RCA: 4] [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: 01/26/2016] [Accepted: 09/20/2016] [Indexed: 11/19/2022] Open
Abstract
Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is a disabling autoimmune disorder of the peripheral nervous system (PNS). Intravenous immunoglobulins (IVIg) are effective in CIDP, but the treatment response varies greatly between individual patients. Understanding this interindividual variability and predicting the response to IVIg constitute major clinical challenges in CIDP. We previously established intercellular adhesion molecule (ICAM)-1 deficient non-obese diabetic (NOD) mice as a novel animal model of CIDP. Here, we demonstrate that similar to human CIDP patients, ICAM-1 deficient NOD mice respond to IVIg treatment by clinical and histological measures. Nerve magnetic resonance imaging and histology demonstrated that IVIg ameliorates abnormalities preferentially in distal parts of the sciatic nerve branches. The IVIg treatment response also featured great heterogeneity allowing us to identify IVIg responders and non-responders. An increased production of interleukin (IL)-17 positively predicted IVIg treatment responses. In human sural nerve biopsy sections, high numbers of IL-17 producing cells were associated with younger age and shorter disease duration. Thus, our novel animal model can be utilized to identify prognostic markers of treatment responses in chronic inflammatory neuropathies and we identify IL-17 production as one potential such prognostic marker.
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Affiliation(s)
- Gerd Meyer zu Horste
- Department of Neurology, Heinrich-Heine-University, Medical Faculty, Düsseldorf, Germany
- Department of Neurology, University Hospital Münster, Münster, Germany
| | - Steffen Cordes
- Department of Neurology, Heinrich-Heine-University, Medical Faculty, Düsseldorf, Germany
| | - Johannes Pfaff
- Department of Neuroradiology, Heidelberg University Hospital, Heidelberg, Germany
| | - Christian Mathys
- Institute of Neuroradiology, Heinrich-Heine-University, Medical Faculty, Düsseldorf, Germany
| | - Anne K. Mausberg
- Department of Neurology, Heinrich-Heine-University, Medical Faculty, Düsseldorf, Germany
| | - Martin Bendszus
- Department of Neuroradiology, Heidelberg University Hospital, Heidelberg, Germany
| | - Mirko Pham
- Department of Neuroradiology, Heidelberg University Hospital, Heidelberg, Germany
| | - Hans-Peter Hartung
- Department of Neurology, Heinrich-Heine-University, Medical Faculty, Düsseldorf, Germany
| | - Bernd C. Kieseier
- Department of Neurology, Heinrich-Heine-University, Medical Faculty, Düsseldorf, Germany
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17
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Cai X, Bandla A, Mao D, Feng G, Qin W, Liao LD, Thakor N, Tang BZ, Liu B. Biocompatible Red Fluorescent Organic Nanoparticles with Tunable Size and Aggregation-Induced Emission for Evaluation of Blood-Brain Barrier Damage. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2016; 28:8760-8765. [PMID: 27511643 DOI: 10.1002/adma.201601191] [Citation(s) in RCA: 61] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2016] [Revised: 05/14/2016] [Indexed: 06/06/2023]
Abstract
Detection of damage to the blood-brain barrier (BBB) is important for the diagnosis of brain diseases and therapeutic drug evaluation. The widely used probe, Evans blue, suffers from low specificity and high toxicity in vivo. It is shown that organic nanoparticles with tuneable size, good biocompatibility, and aggregation-induced emission characteristics offer high detection specificity to detect BBB damage via a photothrombotic ischemia rat model.
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Affiliation(s)
- Xiaolei Cai
- Department of Chemical and Biomolecular Engineering, National University of Singapore, 4 Engineering Drive 4, Singapore, 117585
- NUS Graduate School for Integrative Sciences and Engineering, National University of Singapore, 28 Medical Drive, #05-01, Singapore, 117456
| | - Aishwarya Bandla
- Singapore Institute for Neurotechnology (SINAPSE), National University of Singapore, 28 Medical Drive, Singapore, 117456
- Department of Biomedical Engineering, National University of Singapore, 21 Lower Kent Ridge Road, Singapore, 119077
| | - Duo Mao
- Department of Chemical and Biomolecular Engineering, National University of Singapore, 4 Engineering Drive 4, Singapore, 117585
| | - Guangxue Feng
- Department of Chemical and Biomolecular Engineering, National University of Singapore, 4 Engineering Drive 4, Singapore, 117585
| | - Wei Qin
- Department of Chemistry and Division of Biomedical Engineering, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, 999077
| | - Lun-De Liao
- Singapore Institute for Neurotechnology (SINAPSE), National University of Singapore, 28 Medical Drive, Singapore, 117456.
- Institute of Biomedical Engineering and Nanomedicine, National Health Research Institutes, 35 Keyan Road, Zhunan Town, Miaoli County, 35053, Taiwan.
| | - Nitish Thakor
- Singapore Institute for Neurotechnology (SINAPSE), National University of Singapore, 28 Medical Drive, Singapore, 117456
- Department of Biomedical Engineering, National University of Singapore, 21 Lower Kent Ridge Road, Singapore, 119077
| | - Ben Zhong Tang
- Department of Chemistry and Division of Biomedical Engineering, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, 999077
| | - Bin Liu
- Department of Chemical and Biomolecular Engineering, National University of Singapore, 4 Engineering Drive 4, Singapore, 117585.
- Institute of Materials Research and Engineering, 2 Fusionopolis Way, Innovis, #08-03, Singapore, 138634.
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18
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The Role of Dynamic Contrast-Enhanced MR in Evaluating Level III Collateral Circulation in a Rat Model of Acute Ischemic Stroke. Mol Neurobiol 2016; 54:2731-2738. [PMID: 27003821 DOI: 10.1007/s12035-016-9844-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2016] [Accepted: 03/09/2016] [Indexed: 10/22/2022]
Abstract
The study aimed to investigate the correlations between parameters of permeability magnetic resonance (MR) and the intensity of vasculature in the focal ischemic cortex of a rat model of middle cerebral artery occlusion. In the present study, sham operation or ischemic-reperfusion with tissue plasminogen activator (tPA) thrombolysis were performed in rats. Cranial MR scans and brain tissue samples were obtained from all animals. Brain slices were stained for immunohistological analyses with confocal fluorescence microscopy, and the intensities of microvessels and capillaries were calculated. Consistency between collateral circulation imaging classification and pathological vascular density was analyzed. We found that the K trans value and capillary intensity have the similar trends of declining and increasing, according to different time points, if compared with the sham operation group (P < 0.05). Permeability parameters have better correlations with capillary intensity, and K trans value had the best correlation at 4.5 h (kappa = 0.764, P < 0.001), while injection area under curve (IAUC) at 7 days (kappa = 0.725, P < 0.001). Susceptibility-weighted imaging (SWI) exhibited better correlation with microvessel intensity at both 3 days (kappa = 0.715, P < 0.001) and 7 days (kappa = 0.719, P < 0.001). In conclusion, the permeability parameters, such as IAUC and K trans map, can quantitatively assess capillary intensity, which may indicate angiogenesis categorized as level III collateral circulation after ischemic stroke.
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19
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Salar S, Lapilover E, Müller J, Hollnagel JO, Lippmann K, Friedman A, Heinemann U. Synaptic plasticity in area CA1 of rat hippocampal slices following intraventricular application of albumin. Neurobiol Dis 2016; 91:155-65. [PMID: 26972679 DOI: 10.1016/j.nbd.2016.03.008] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2015] [Revised: 02/16/2016] [Accepted: 03/09/2016] [Indexed: 12/16/2022] Open
Abstract
Epileptogenesis following insults to the brain may be triggered by a dysfunctional blood-brain barrier (BBB) associated with albumin extravasation and activation of astrocytes. Using ex vivo recordings from the BBB-disrupted hippocampus after neocortical photothrombotic stroke, we previously demonstrated abnormal activity-dependent accumulation of extracellular potassium with facilitated generation of seizure like events and spreading depolarizations. Similar changes could be observed after intracerebroventricular (icv) application of albumin. We hypothesized that alterations in extracellular potassium and glutamate homeostasis might lead to alterations in synaptic interactions. We therefore assessed the effects of icv albumin on homo- and heterosynaptic plasticity in hippocampal CA1, 24h after a single injection or 7days after continuous infusion of icv albumin. We demonstrate alterations in both homo- and heterosynaptic plasticity compared to control conditions in ex vivo slice studies. Albumin-treated tissue reveals (1) reduced long-term depression following low-frequency stimulation; (2) increased long-term potentiation of population spikes in response to 20Hz stimulation; (3) potentiated responses to Schaffer collateral stimulation following high-frequency stimulation of the direct cortical input and low-frequency stimulation of alveus and finally, (4) TGFβ receptor II (TGFβR-II) involvement in albumin-induced homosynaptic plasticity changes. We conclude that albumin-induced network hyperexcitability is associated with abnormal homo- and heterosynaptic plasticity that could partly be reversed by interference with TGFβR-II-mediated signaling and therefore it might be an important factor in the process of epileptogenesis.
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Affiliation(s)
- Seda Salar
- Neuroscience Research Center and Institute of Neurophysiology, Charite-University Medicine Berlin, Berlin, Germany
| | - Ezequiel Lapilover
- Neuroscience Research Center and Institute of Neurophysiology, Charite-University Medicine Berlin, Berlin, Germany
| | - Julia Müller
- Neuroscience Research Center and Institute of Neurophysiology, Charite-University Medicine Berlin, Berlin, Germany
| | - Jan-Oliver Hollnagel
- Neuroscience Research Center and Institute of Neurophysiology, Charite-University Medicine Berlin, Berlin, Germany
| | - Kristina Lippmann
- Neuroscience Research Center and Institute of Neurophysiology, Charite-University Medicine Berlin, Berlin, Germany
| | - Alon Friedman
- Neuroscience Research Center and Institute of Neurophysiology, Charite-University Medicine Berlin, Berlin, Germany; Departments of Cognitive and Brain Sciences, Zlotowski Center for Neuroscience, Ben-Gurion University of the Negev, Beer-Sheva, Israel; Department of Medical Neuroscience, Faculty of Medicine, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Uwe Heinemann
- Neuroscience Research Center and Institute of Neurophysiology, Charite-University Medicine Berlin, Berlin, Germany.
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20
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De Bock M, Van Haver V, Vandenbroucke RE, Decrock E, Wang N, Leybaert L. Into rather unexplored terrain-transcellular transport across the blood-brain barrier. Glia 2016; 64:1097-123. [DOI: 10.1002/glia.22960] [Citation(s) in RCA: 92] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2015] [Revised: 11/16/2015] [Accepted: 12/03/2015] [Indexed: 01/22/2023]
Affiliation(s)
- Marijke De Bock
- Physiology Group, Department of Basic Medical Sciences; Ghent University; Ghent Belgium
| | - Valérie Van Haver
- Physiology Group, Department of Basic Medical Sciences; Ghent University; Ghent Belgium
| | - Roosmarijn E. Vandenbroucke
- Inflammation Research Center, VIB; Ghent Belgium
- Department of Biomedical Molecular Biology; Ghent University; Ghent Belgium
| | - Elke Decrock
- Physiology Group, Department of Basic Medical Sciences; Ghent University; Ghent Belgium
| | - Nan Wang
- Physiology Group, Department of Basic Medical Sciences; Ghent University; Ghent Belgium
| | - Luc Leybaert
- Physiology Group, Department of Basic Medical Sciences; Ghent University; Ghent Belgium
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21
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In vitro seizure like events and changes in ionic concentration. J Neurosci Methods 2015; 260:33-44. [PMID: 26300181 DOI: 10.1016/j.jneumeth.2015.08.014] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2015] [Revised: 08/06/2015] [Accepted: 08/12/2015] [Indexed: 11/20/2022]
Abstract
BACKGROUND In vivo, seizure like events are associated with increases in extracellular K(+) concentration, decreases in extracellular Ca(2+) concentration, diphasic changes in extracellular sodium, chloride, and proton concentration, as well as changes of extracellular space size. These changes point to mechanisms underlying the induction, spread and termination of seizure like events. METHODS We investigated the potential role of alterations of the ionic environment on the induction of seizure like events-considering a review of the literature and own experimental work in animal and human slices. RESULTS Increasing extracellular K(+) concentration, lowering extracellular Mg(2+) concentration, or lowering extracellular Ca(2+) concentration can induce seizure like events. In human tissue from epileptic patients, elevation of K(+) concentration induces seizure like events in the dentate gyrus and subiculum. A combination of elevated K(+) concentration and 4-AP or bicuculline can induce seizure like events in neocortical tissue. CONCLUSIONS These protocols provide insight into the mechanisms involved in seizure initiation, spread and termination. Moreover, pharmacological studies as well as studies on mechanisms underlying pharmacoresistance are feasible.
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Liu DF, Qian C, An YL, Chang D, Ju SH, Teng GJ. Magnetic resonance imaging of post-ischemic blood-brain barrier damage with PEGylated iron oxide nanoparticles. NANOSCALE 2014; 6:15161-7. [PMID: 25374303 DOI: 10.1039/c4nr03942d] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Blood-brain barrier (BBB) damage during ischemia may induce devastating consequences like cerebral edema and hemorrhagic transformation. This study presents a novel strategy for dynamically imaging of BBB damage with PEGylated supermagnetic iron oxide nanoparticles (SPIONs) as contrast agents. The employment of SPIONs as contrast agents made it possible to dynamically image the BBB permeability alterations and ischemic lesions simultaneously with T2-weighted MRI, and the monitoring could last up to 24 h with a single administration of PEGylated SPIONs in vivo. The ability of the PEGylated SPIONs to highlight BBB damage by MRI was demonstrated by the colocalization of PEGylated SPIONs with Gd-DTPA after intravenous injection of SPION-PEG/Gd-DTPA into a mouse. The immunohistochemical staining also confirmed the leakage of SPION-PEG from cerebral vessels into parenchyma. This study provides a novel and convenient route for imaging BBB alteration in the experimental ischemic stroke model.
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Affiliation(s)
- Dong-Fang Liu
- Jiangsu Key Laboratory of Molecular and Functional Imaging, Department of Radiology, Medical School, Zhongda Hospital, Southeast University, No. 87, Dingjiaqiao, Nanjing 210009, China.
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Ruck T, Bittner S, Epping L, Herrmann AM, Meuth SG. Isolation of primary murine brain microvascular endothelial cells. J Vis Exp 2014:e52204. [PMID: 25489873 PMCID: PMC4354020 DOI: 10.3791/52204] [Citation(s) in RCA: 63] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
The blood-brain-barrier is ultrastructurally assembled by a monolayer of brain microvascular endothelial cells (BMEC) interconnected by a junctional complex of tight and adherens junctions. Together with other cell-types such as astrocytes or pericytes, they form the neurovascular unit (NVU), which specifically regulates the interchange of fluids, molecules and cells between the peripheral blood and the CNS. Through this complex and dynamic system BMECs are involved in various processes maintaining the homeostasis of the CNS. A dysfunction of the BBB is observed as an essential step in the pathogenesis of many severe CNS diseases. However, specific and targeted therapies are very limited, as the underlying mechanisms are still far from being understood. Animal and in vitro models have been extensively used to gain in-depth understanding of complex physiological and pathophysiological processes. By reduction and simplification it is possible to focus the investigation on the subject of interest and to exclude a variety of confounding factors. However, comparability and transferability are also reduced in model systems, which have to be taken into account for evaluation. The most common animal models are based on mice, among other reasons, mainly due to the constantly increasing possibilities of methodology. In vitro studies of isolated murine BMECs might enable an in-depth analysis of their properties and of the blood-brain-barrier under physiological and pathophysiological conditions. Further insights into the complex mechanisms at the BBB potentially provide the basis for new therapeutic strategies. This protocol describes a method to isolate primary murine microvascular endothelial cells by a sequence of physical and chemical purification steps. Special considerations for purity and cultivation of MBMECs as well as quality control, potential applications and limitations are discussed.
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Affiliation(s)
- Tobias Ruck
- Department of Neurology, University of Münster;
| | - Stefan Bittner
- Department of Neurology, University of Münster; Interdisciplinary Center for Clinical Research (IZKF) Münster
| | - Lisa Epping
- Department of Neurology, University of Münster
| | | | - Sven G Meuth
- Department of Neurology, University of Münster; Institute of Physiology I - Neuropathophysiology I, University of Münster
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Schoknecht K, David Y, Heinemann U. The blood-brain barrier-gatekeeper to neuronal homeostasis: clinical implications in the setting of stroke. Semin Cell Dev Biol 2014; 38:35-42. [PMID: 25444848 DOI: 10.1016/j.semcdb.2014.10.004] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2014] [Revised: 10/24/2014] [Accepted: 10/31/2014] [Indexed: 12/23/2022]
Abstract
The blood-brain barrier is part of the neurovascular unit and serves as a functional and anatomical barrier between the blood and the extracellular space. It controls the flow of solutes in and out of the brain thereby providing an optimal environment for neuronal functioning. Paracellular transport between endothelial cells is restricted by tight junctions and transendothelial transport is reduced and more selective compared to capillaries of other organs. Further, the blood-brain barrier is involved in controlling blood flow and it is the site for signaling damage of the nervous system to the peripheral immune system. As an important player in brain homeostasis, blood-brain barrier dysfunction has been implicated in the pathophysiology of many brain diseases including stroke, traumatic brain injury, brain tumors, epilepsy and neurodegenerative disorders. In this article - highlighting recent advances in basic science - we review the features of the blood-brain barrier and their significance for neuronal homeostasis to discuss clinical implications for neurological complications following cerebral ischemia.
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Affiliation(s)
- Karl Schoknecht
- Institute for Neurophysiology, Charité - University Medicine Berlin, Germany
| | - Yaron David
- Departments of Physiology & Cell Biology, Cognitive & Brain Sciences, The Zlotowski Center for Neuroscience, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Uwe Heinemann
- Institute for Neurophysiology, Charité - University Medicine Berlin, Germany.
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25
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Schoknecht K, Prager O, Vazana U, Kamintsky L, Harhausen D, Zille M, Figge L, Chassidim Y, Schellenberger E, Kovács R, Heinemann U, Friedman A. Monitoring stroke progression: in vivo imaging of cortical perfusion, blood-brain barrier permeability and cellular damage in the rat photothrombosis model. J Cereb Blood Flow Metab 2014; 34:1791-801. [PMID: 25160672 PMCID: PMC4269756 DOI: 10.1038/jcbfm.2014.147] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/30/2014] [Revised: 07/15/2014] [Accepted: 07/21/2014] [Indexed: 11/09/2022]
Abstract
Focal cerebral ischemia is among the main causes of death and disability worldwide. The ischemic core often progresses, invading the peri-ischemic brain; however, assessing the propensity of the peri-ischemic brain to undergo secondary damage, understanding the underlying mechanisms, and adjusting treatment accordingly remain clinically unmet challenges. A significant hallmark of the peri-ischemic brain is dysfunction of the blood-brain barrier (BBB), yet the role of disturbed vascular permeability in stroke progression is unclear. Here we describe a longitudinal in vivo fluorescence imaging approach for the evaluation of cortical perfusion, BBB dysfunction, free radical formation and cellular injury using the photothrombosis vascular occlusion model in male Sprague Dawley rats. Blood-brain barrier dysfunction propagated within the peri-ischemic brain in the first hours after photothrombosis and was associated with free radical formation and cellular injury. Inhibiting free radical signaling significantly reduced progressive cellular damage after photothrombosis, with no significant effect on blood flow and BBB permeability. Our approach allows a dynamic follow-up of cellular events and their response to therapeutics in the acutely injured cerebral cortex.
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Affiliation(s)
- Karl Schoknecht
- Institute for Neurophysiology, Charité-University Medicine Berlin, Berlin, Germany
| | - Ofer Prager
- Departments of Physiology and Cell Biology, Cognitive and Brain Sciences, The Zlotowski Center for Neuroscience, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Udi Vazana
- Departments of Physiology and Cell Biology, Cognitive and Brain Sciences, The Zlotowski Center for Neuroscience, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Lyn Kamintsky
- Departments of Physiology and Cell Biology, Cognitive and Brain Sciences, The Zlotowski Center for Neuroscience, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Denise Harhausen
- Department of Experimental Neurology, Center for Stroke Research Berlin (CSB), Charité-University Medicine Berlin, Berlin, Germany
| | - Marietta Zille
- Department of Experimental Neurology, Center for Stroke Research Berlin (CSB), Charité-University Medicine Berlin, Berlin, Germany
| | - Lena Figge
- Department of Radiology, Charité-University Medicine Berlin, Berlin, Germany
| | - Yoash Chassidim
- Departments of Physiology and Cell Biology, Cognitive and Brain Sciences, The Zlotowski Center for Neuroscience, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Eyk Schellenberger
- Department of Radiology, Charité-University Medicine Berlin, Berlin, Germany
| | - Richard Kovács
- Institute for Neurophysiology, Charité-University Medicine Berlin, Berlin, Germany
| | - Uwe Heinemann
- Institute for Neurophysiology, Charité-University Medicine Berlin, Berlin, Germany
| | - Alon Friedman
- 1] Departments of Physiology and Cell Biology, Cognitive and Brain Sciences, The Zlotowski Center for Neuroscience, Ben-Gurion University of the Negev, Beer-Sheva, Israel [2] Department of Medical Neuroscience, Faculty of Medicine, Dalhousie University, Halifax, Canada
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Nathoo N, Yong VW, Dunn JF. Understanding disease processes in multiple sclerosis through magnetic resonance imaging studies in animal models. NEUROIMAGE-CLINICAL 2014; 4:743-56. [PMID: 24936425 PMCID: PMC4053634 DOI: 10.1016/j.nicl.2014.04.011] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/28/2014] [Revised: 04/21/2014] [Accepted: 04/22/2014] [Indexed: 01/11/2023]
Abstract
There are exciting new advances in multiple sclerosis (MS) resulting in a growing understanding of both the complexity of the disorder and the relative involvement of grey matter, white matter and inflammation. Increasing need for preclinical imaging is anticipated, as animal models provide insights into the pathophysiology of the disease. Magnetic resonance (MR) is the key imaging tool used to diagnose and to monitor disease progression in MS, and thus will be a cornerstone for future research. Although gadolinium-enhancing and T2 lesions on MRI have been useful for detecting MS pathology, they are not correlative of disability. Therefore, new MRI methods are needed. Such methods require validation in animal models. The increasing necessity for MRI of animal models makes it critical and timely to understand what research has been conducted in this area and what potential there is for use of MRI in preclinical models of MS. Here, we provide a review of MRI and magnetic resonance spectroscopy (MRS) studies that have been carried out in animal models of MS that focus on pathology. We compare the MRI phenotypes of animals and patients and provide advice on how best to use animal MR studies to increase our understanding of the linkages between MR and pathology in patients. This review describes how MRI studies of animal models have been, and will continue to be, used in the ongoing effort to understand MS. MRI studies of pathology in various animal models of MS are reviewed. MRI phenotypes in animal models of MS and MS patients are compared. Animal MRI can increase understanding of links between MR and pathology in patients.
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Affiliation(s)
- Nabeela Nathoo
- Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada
- Department of Radiology, University of Calgary, Calgary, Alberta, Canada
| | - V. Wee Yong
- Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada
- Department of Clinical Neurosciences, University of Calgary, Calgary, Alberta, Canada
| | - Jeff F. Dunn
- Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada
- Department of Radiology, University of Calgary, Calgary, Alberta, Canada
- Department of Clinical Neurosciences, University of Calgary, Calgary, Alberta, Canada
- Experimental Imaging Centre, University of Calgary, Calgary, Alberta, Canada
- Corresponding author at: Department of Radiology, University of Calgary, 3330 Hospital Drive, N.W., Calgary, Alberta T2N 4N1, Canada.
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He Z, Wang X, Wu Y, Jia J, Hu Y, Yang X, Li J, Fan M, Zhang L, Guo J, Leung MCP. Treadmill pre-training ameliorates brain edema in ischemic stroke via down-regulation of aquaporin-4: an MRI study in rats. PLoS One 2014; 9:e84602. [PMID: 24416250 PMCID: PMC3886991 DOI: 10.1371/journal.pone.0084602] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2013] [Accepted: 11/15/2013] [Indexed: 01/23/2023] Open
Abstract
Objective Treadmill pre-training can ameliorate blood brain barrier (BBB) dysfunction in ischemia-reperfusion injury, however, its role in ischemic brain edema remains unclear. This study assessed the neuroprotective effects induced by treadmill pre-training, particularly on brain edema in transient middle cerebral artery occluded model. Methods Transient middle cerebral artery occlusion to induce stroke was performed on rats after 2 weeks of treadmill pre-training. Magnetic resonance imaging (MRI) was used to evaluate the dynamic impairment of cerebral edema after ischemia-reperfusion injury. In addition, measurements of wet and dry brain weight, Evans Blue assay and Garcia scores were performed to investigate the cerebral water content, BBB permeability and neurologic deficit, respectively. Moreover, during ischemia-reperfusion injury, the expression of Aquaporin 4 (AQP4) was detected using immunofluorescence and Western bloting analyses. Results Treadmill pre-training improved the relative apparent diffusion coefficient (rADC) loss in the ipsilateral cortex and striatum at 1 hour and 2.5 hours after cerebral ischemia. In the treadmill pre-training group, T2W1 values of the ipsilateral cortex and striatum increased less at 7.5 hours, 1 day, and 2 days after stroke while the brain water content decreased at 2 days after ischemia. Regarding the BBB permeability, the semi-quantitative amount of contrast agent leakage of treadmill pre-training group significantly decreased. Less Evans Blue exudation was also observed in treadmill pre-training group at 2 days after stroke. In addition, treadmill pre-training mitigated the Garcia score deficits at 2 days after stroke. Immunofluorescence staining and Western blotting results showed a significant decrease in the expression of AQP4 after treadmill ischemia following pre-training. Conclusions Treadmill pre-training may reduce cerebral edema and BBB dysfunction during cerebral ischemia/reperfusion injury via the down-regulation of AQP4.
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Affiliation(s)
- Zhijie He
- Department of Rehabilitation, Huashan Hospital, Fudan University, Shanghai, China
| | - Xiaolou Wang
- Department of Rehabilitation, Huashan Hospital, Fudan University, Shanghai, China
| | - Yi Wu
- Department of Rehabilitation, Huashan Hospital, Fudan University, Shanghai, China
| | - Jie Jia
- Department of Rehabilitation, Huashan Hospital, Fudan University, Shanghai, China
- * E-mail: (JJ); (JG)
| | - Yongshan Hu
- Department of Rehabilitation, Huashan Hospital, Fudan University, Shanghai, China
- State Key Laboratory of Medical Neurobiology, Shanghai Medical College, Fudan University, Shanghai, China
| | - Xiaojiao Yang
- Department of Rehabilitation, Huashan Hospital, Fudan University, Shanghai, China
| | - Jianqi Li
- Shanghai Key Laboratory of Magnetic Resonance, Department of Physics, East China Normal University, Shanghai, China
| | - Mingxia Fan
- Shanghai Key Laboratory of Magnetic Resonance, Department of Physics, East China Normal University, Shanghai, China
| | - Li Zhang
- Department of Rehabilitation, Huashan Hospital, Fudan University, Shanghai, China
| | - Jinchun Guo
- State Key Laboratory of Medical Neurobiology, Shanghai Medical College, Fudan University, Shanghai, China
- * E-mail: (JJ); (JG)
| | - Mason C. P. Leung
- Department of Rehabilitation Sciences, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong, SAR, China
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28
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Ofek K, Schoknecht K, Melamed-Book N, Heinemann U, Friedman A, Soreq H. Fluoxetine induces vasodilatation of cerebral arterioles by co-modulating NO/muscarinic signalling. J Cell Mol Med 2014; 16:2736-44. [PMID: 22697296 PMCID: PMC4118242 DOI: 10.1111/j.1582-4934.2012.01596.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Ischaemic stroke patients treated with Selective Serotonin Reuptake Inhibitors (SSRI) show improved motor, cognitive and executive functions, but the underlying mechanism(s) are incompletely understood. Here, we report that cerebral arterioles in the rat brain superfused with therapeutically effective doses of the SSRI fluoxetine showed consistent, dose-dependent vasodilatation (by 1.2 to 1.6-fold), suppressible by muscarinic and nitric oxide synthase (NOS) antagonists [atropine, NG-nitro-l-arginine methyl ester (l-NAME)] but resistant to nicotinic and serotoninergic antagonists (mecamylamine, methylsergide). Fluoxetine administered 10–30 min. following experimental vascular photo-thrombosis increased arterial diameter (1.3–1.6), inducing partial, but lasting reperfusion of the ischaemic brain. In brain endothelial b.End.3 cells, fluoxetine induced rapid muscarinic receptor-dependent increases in intracellular [Ca2+] and promoted albumin- and eNOS-dependent nitric oxide (NO) production and HSP90 interaction. In vitro, fluoxetine suppressed recombinant human acetylcholinesterase (rhAChE) activity only in the presence of albumin. That fluoxetine induces vasodilatation of cerebral arterioles suggests co-promotion of endothelial muscarinic and nitric oxide signalling, facilitated by albumin-dependent inhibition of serum AChE.
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Affiliation(s)
- Keren Ofek
- Edmond and Lily Safra Center for Brain Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel
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29
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Stroke-induced brain parenchymal injury drives blood-brain barrier early leakage kinetics: a combined in vivo/in vitro study. J Cereb Blood Flow Metab 2014; 34:95-107. [PMID: 24084699 PMCID: PMC3887349 DOI: 10.1038/jcbfm.2013.169] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/06/2013] [Revised: 08/14/2013] [Accepted: 09/02/2013] [Indexed: 12/13/2022]
Abstract
The disappointing clinical outcomes of neuroprotectants challenge the relevance of preclinical stroke models and data in defining early cerebrovascular events as potential therapeutic targets. The kinetics of blood-brain barrier (BBB) leakage after reperfusion and the link with parenchymal lesion remain debated. By using in vivo and in vitro approaches, we conducted a kinetic analysis of BBB dysfunction during early reperfusion. After 60 minutes of middle cerebral artery occlusion followed by reperfusion times up to 24 hours in mice, a non-invasive magnetic resonance imaging method, through an original sequence of diffusion-weighted imaging, determined brain water mobility in microvascular compartments (D*) apart from parenchymal compartments (apparent diffusion coefficient). An increase in D* found at 4 hours post reperfusion concurred with the onset of both Evans blue/Dextran extravasations and in vitro BBB opening under oxygen-glucose deprivation and reoxygenation (R). The BBB leakage coincided with an emerging cell death in brain tissue as well as in activated glial cells in vitro. The co-culture of BBB endothelial and glial cells evidenced a recovery of endothelium tightness when glial cells were absent or non-injured during R. Preserving the ischemic brain parenchymal cells within 4 hours of reperfusion may improve therapeutic strategies for cerebrovascular protection against stroke.
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30
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Nathoo N, Yong VW, Dunn JF. Using magnetic resonance imaging in animal models to guide drug development in multiple sclerosis. Mult Scler 2013; 20:3-11. [PMID: 24263386 DOI: 10.1177/1352458513512709] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Major advances are taking place in the development of therapeutics for multiple sclerosis (MS), with a move past traditional immunomodulatory/immunosuppressive therapies toward medications aimed at promoting remyelination or neuroprotection. With an increase in diversity of MS therapies comes the need to assess the effectiveness of such therapies. Magnetic resonance imaging (MRI) is one of the main tools used to evaluate the effectiveness of MS therapeutics in clinical trials. As all new therapeutics for MS are tested in animal models first, it is logical that MRI be incorporated into preclinical studies assessing therapeutics. Here, we review key papers showing how MR imaging has been combined with a range of animal models to evaluate potential therapeutics for MS. We also advise on how to maximize the potential for incorporating MRI into preclinical studies evaluating possible therapeutics for MS, which should improve the likelihood of discovering new medications for the condition.
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Affiliation(s)
- Nabeela Nathoo
- Hotchkiss Brain Institute, University of Calgary, Canada
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31
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Stubbs DJ, Yamamoto AK, Menon DK. Imaging in sepsis-associated encephalopathy--insights and opportunities. Nat Rev Neurol 2013; 9:551-61. [PMID: 23999468 DOI: 10.1038/nrneurol.2013.177] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Sepsis-associated encephalopathy (SAE) refers to a clinical spectrum of acute neurological dysfunction that arises in the context of sepsis. Although the pathophysiology of SAE is incompletely understood, it is thought to involve endothelial activation, blood-brain barrier leakage, inflammatory cell migration, and neuronal loss with neurotransmitter imbalance. SAE is associated with a high risk of mortality. Imaging studies using MRI and CT have demonstrated changes in the brains of patients with SAE that are also seen in disorders such as stroke. Next-generation imaging techniques such as magnetic resonance spectroscopy, diffusion tensor imaging and PET, as well as experimental imaging modalities, provide options for early identification of patients with SAE, and could aid in identification of pathophysiological processes that represent possible therapeutic targets. In this Review, we explore the recent literature on imaging in SAE, relating the findings of these studies to pathological data and experimental studies to obtain insights into the pathophysiology of sepsis-associated neurological dysfunction. Furthermore, we suggest how novel imaging technologies can be used for early-stage proof-of-concept and proof-of-mechanism translational studies, which may help to improve diagnosis in SAE.
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Affiliation(s)
- Daniel J Stubbs
- Division of Anaesthesia, Department of Medicine, University of Cambridge, Addenbrooke's Hospital, Hills Road, Cambridge CB2 2QQ, UK
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Wunder A, Schoknecht K, Stanimirovic DB, Prager O, Chassidim Y. Imaging blood-brain barrier dysfunction in animal disease models. Epilepsia 2013; 53 Suppl 6:14-21. [PMID: 23134491 DOI: 10.1111/j.1528-1167.2012.03698.x] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The blood-brain barrier (BBB) is a highly complex structure, which separates the extracellular fluid of the central nervous system (CNS) from the blood of CNS vessels. A wide range of neurologic conditions, including stroke, epilepsy, Alzheimer's disease, and brain tumors, are associated with perturbations of the BBB that contribute to their pathology. The common consequence of a BBB dysfunction is increased permeability, leading to extravasation of plasma constituents and vasogenic brain edema. The BBB impairment can persist for long periods, being involved in secondary inflammation and neuronal dysfunction, thus contributing to disease pathogenesis. Therefore, reliable imaging of the BBB impairment is of major importance in both clinical management of brain diseases and in experimental research. From landmark studies by Ehrlich and Goldman, the use of dyes (probes) has played a critical role in understanding BBB functions. In recent years methodologic advances in morphologic and functional brain imaging have provided insight into cellular and molecular interactions underlying BBB dysfunction in animal disease models. These imaging techniques, which range from in situ staining to noninvasive in vivo imaging, have different spatial resolution, sensitivity, and capacity for quantitative and kinetic measures of the BBB impairment. Despite significant advances, the translation of these techniques into clinical applications remains slow. This review outlines key recent advances in imaging techniques that have contributed to the understanding of BBB dysfunction in disease and discusses major obstacles and opportunities to advance these techniques into the clinical realm.
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Affiliation(s)
- Andreas Wunder
- Department of Experimental Neurology, Center for Stroke Research Berlin, Charité-University Medicine Berlin, Berlin, Germany.
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Kang EJ, Major S, Jorks D, Reiffurth C, Offenhauser N, Friedman A, Dreier JP. Blood-brain barrier opening to large molecules does not imply blood-brain barrier opening to small ions. Neurobiol Dis 2013; 52:204-18. [PMID: 23291193 DOI: 10.1016/j.nbd.2012.12.007] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2012] [Revised: 11/10/2012] [Accepted: 12/20/2012] [Indexed: 10/27/2022] Open
Abstract
Neuroimaging of exogenous tracer extravasation has become the technique of choice in preclinical and clinical studies of blood-brain barrier permeability. Such tracers have a larger molecular weight than small ions, neurotransmitters and many drugs. Therefore, it is assumed that tracer extravasation indicates both permeability to these and the cancelation of the electrical polarization across the barrier. Electrophysiological anomalies following intracarotideal administration of dehydrocholate, a bile salt causing extravasation of the albumin-binding tracer Evans blue, seemingly supported this. By contrast, electron microscopic studies suggested a different hierarchical pattern of blood-brain barrier dysfunction, a milder degree of impairment being characterized by increased function of the transcellular pathway and a severe degree by opening of the tight junctions. This would imply that the extravasation of macromolecules can occur before disruption of the electrical barrier. However, functional evidence for this has been lacking. Here, we further investigated the electrophysiological anomalies following intracarotideal application of dehydrocholate in rats and found that it caused focal cerebral ischemia by middle cerebral artery thrombosis, the electrophysiological recordings being characteristic of long-lasting spreading depolarization. These observations indicated that intracarotideal dehydrocholate is not a suitable model to study the isolated dysfunction of the blood-brain barrier. Second, we studied the topical application of dehydrocholate to the brain and the application of mannitol into the carotid artery. In both models, we found significant extravasation of Evans blue but no changes in either extracellular potassium or the CO(2)-dependent intracortical direct current deflection. The latter is assumed to depend on the proton gradient across the barrier in rats which we confirmed in additional experiments in vivo and in vitro. The stability of the extracellular potassium concentration and the CO(2)-dependent direct current deflection are two functional tests which indicate the integrity of the electrical barrier. Hence, our results provide functional evidence that the blood-brain barrier opening to large molecules does not necessarily imply the opening to small ions consistent with the hierarchy of damage in the previous electron microscopic studies.
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Affiliation(s)
- E J Kang
- Department of Experimental Neurology, Charité Universitätsmedizin, 10117 Berlin, Germany
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34
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Weise G, Stoll G. Magnetic resonance imaging of blood brain/nerve barrier dysfunction and leukocyte infiltration: closely related or discordant? Front Neurol 2012; 3:178. [PMID: 23267343 PMCID: PMC3527731 DOI: 10.3389/fneur.2012.00178] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2012] [Accepted: 12/03/2012] [Indexed: 11/13/2022] Open
Abstract
Unlike other organs the nervous system is secluded from the rest of the organism by the blood brain barrier (BBB) or blood nerve barrier (BNB) preventing passive influx of fluids from the circulation. Similarly, leukocyte entry to the nervous system is tightly controlled. Breakdown of these barriers and cellular inflammation are hallmarks of inflammatory as well as ischemic neurological diseases and thus represent potential therapeutic targets. The spatiotemporal relationship between BBB/BNB disruption and leukocyte infiltration has been a matter of debate. We here review contrast-enhanced magnetic resonance imaging (MRI) as a non-invasive tool to depict barrier dysfunction and its relation to macrophage infiltration in the central and peripheral nervous system under pathological conditions. Novel experimental contrast agents like Gadofluorine M (Gf) allow more sensitive assessment of BBB dysfunction than conventional Gadolinium (Gd)-DTPA enhanced MRI. In addition, Gf facilitates visualization of functional and transient alterations of the BBB remote from lesions. Cellular contrast agents such as superparamagnetic iron oxide particles (SPIO) and perfluorocarbons enable assessment of leukocyte (mainly macrophage) infiltration by MR technology. Combined use of these MR contrast agents disclosed that leukocytes can enter the nervous system independent from a disturbance of the BBB, and vice versa, a dysfunctional BBB/BNB by itself is not sufficient to attract inflammatory cells from the circulation. We will illustrate these basic imaging findings in animal models of multiple sclerosis, cerebral ischemia, and traumatic nerve injury and review corresponding findings in patients.
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Affiliation(s)
- Gesa Weise
- Department of Neurology, University of Wuerzburg Wuerzburg, Germany ; Fraunhofer Institute for Cell Therapy and Immunology Leipzig, Germany ; Translational Center for Regenerative Medicine Leipzig, Germany
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Lapilover EG, Lippman K, Salar S, Maslarova A, Dreier JP, Heinemann U, Friedman A. Peri-infarct blood-brain barrier dysfunction facilitates induction of spreading depolarization associated with epileptiform discharges. Neurobiol Dis 2012; 48:495-506. [PMID: 22782081 PMCID: PMC3588590 DOI: 10.1016/j.nbd.2012.06.024] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2012] [Revised: 06/12/2012] [Accepted: 06/27/2012] [Indexed: 11/17/2022] Open
Abstract
Recent studies showed that spreading depolarizations (SDs) occurs abundantly in patients following ischemic stroke and experimental evidence suggests that SDs recruit tissue at risk into necrosis. We hypothesized that BBB opening with consequent alterations of the extracellular electrolyte composition and extravasation of albumin facilitates generation of SDs since albumin mediates an astrocyte transcriptional response with consequent disturbance of potassium and glutamate homeostasis. Here we show extravasation of Evans blue-albumin complex into the hippocampus following cortical photothrombotic stroke in the neighboring neocortex. Using extracellular field potential recordings and exposure to serum electrolytes we observed spontaneous SDs in 80% of hippocampal slices obtained from rats 24 h after cortical photothrombosis. Hippocampal exposure to albumin for 24 h through intraventricular application together with serum electrolytes lowered the threshold for the induction of SDs in most slices irrespective of the pathway of stimulation. Exposing acute slices from naive animals to albumin led also to a reduced SD threshold. In albumin-exposed slices the onset of SDs was usually associated with larger stimulus-induced accumulation of extracellular potassium, and preceded by epileptiform activity, which was also observed during the recovery phase of SDs. Application of ifenprodil (3 μM), an NMDA-receptor type 2 B antagonist, blocked stimulus dependent epileptiform discharges and generation of SDs in slices from animals treated with albumin in-vivo. We suggest that BBB opening facilitates the induction of peri-infarct SDs through impaired homeostasis of K+.
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Affiliation(s)
- EG Lapilover
- Institute of Neurophysiology, Charité Universitätsmedizin, 13347 Berlin, Germany
| | - K. Lippman
- Institute of Neurophysiology, Charité Universitätsmedizin, 13347 Berlin, Germany
| | - S. Salar
- Institute of Neurophysiology, Charité Universitätsmedizin, 13347 Berlin, Germany
| | - A. Maslarova
- Institute of Neurophysiology, Charité Universitätsmedizin, 13347 Berlin, Germany
| | - JP Dreier
- Center for Stroke Research Berlin, Charité Universitätsmedizin, 10117 Berlin, Germany
- Department of Experimental Neurology, Charité Universitätsmedizin, 10117 Berlin, Germany
- Department of Neurology, Charité Universitätsmedizin, 10117 Berlin, Germany
| | - U. Heinemann
- Institute of Neurophysiology, Charité Universitätsmedizin, 13347 Berlin, Germany
- Neurocure Research Center, Charité Universitätsmedizin, 13347 Berlin, Germany
| | - A. Friedman
- Institute of Neurophysiology, Charité Universitätsmedizin, 13347 Berlin, Germany
- Department of Physiology and Neurobiology, Faculty of Health Sciences and Zlotowski Center for Neuroscience, Ben-Gurion University of the Negev, Beer-Sheva, 84105, Israel
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Boltze J, Kleinschnitz C, Reymann KG, Reiser G, Wagner DC, Kranz A, Michalski D. Neurovascular pathophysiology in cerebral ischemia, dementia and the ageing brain - current trends in basic, translational and clinical research. EXPERIMENTAL & TRANSLATIONAL STROKE MEDICINE 2012; 4:14. [PMID: 22883324 PMCID: PMC3431988 DOI: 10.1186/2040-7378-4-14] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2012] [Accepted: 08/03/2012] [Indexed: 06/01/2023]
Abstract
The 7th International Symposium on Neuroprotection and Neurorepair was held from May 2nd to May 5th, 2012 in Potsdam, Germany. The symposium, which directly continues the successful Magdeburg meeting series, attracted over 330 colleagues from 29 countries to discuss recent findings and advances in the field. The focus of the 2012 symposium was widened from stroke and traumatic brain injury to neurodegenerative diseases, notably dementia, and more generally the ageing brain. Thereby, emphasis was given on neurovascular aspects of neurodegeneration and stroke including the blood-brain barrier, recent findings regarding the pathomechanism of Alzheimer's disease, and brain imaging approaches. In addition, neurobiochemical aspects of neuroprotection, the role of astrogliosis, the clinical progress of cell-based approaches as well as translational hurdles and opportunities were discussed in-depth. This review summarizes some of the most stimulating discussions and reports from the meeting.
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Affiliation(s)
- Johannes Boltze
- Fraunhofer-Institute for Cell Therapy and Immunology, Perlickstr. 1, D-04103 Leipzig, Germany
- Translational Centre for Regenerative Medicine, University of Leipzig, Philipp-Rosenthal-Str. 55, D-04103 Leipzig, Germany
| | - Christoph Kleinschnitz
- Department of Neurology, University of Würzburg, Josef-Schneider-Str. 11, D-97080 Würzburg, Germany
| | - Klaus G Reymann
- Leibniz Institute for Neurobiology, Project Group Neuropharmacology, Brenneckestr. 6, D-39118 Magdeburg, Germany
- German Centre for Neurodegenerative Diseases (DZNE), site Magdeburg, Leipziger Str. 44, D-39120 Magdeburg, Germany
| | - Georg Reiser
- Institute of Neurobiochemistry, Otto-von-Guericke-University Magdeburg, Leipziger Str. 44, D-39120 Magdeburg, Germany
| | - Daniel-Christoph Wagner
- Fraunhofer-Institute for Cell Therapy and Immunology, Perlickstr. 1, D-04103 Leipzig, Germany
- Translational Centre for Regenerative Medicine, University of Leipzig, Philipp-Rosenthal-Str. 55, D-04103 Leipzig, Germany
| | - Alexander Kranz
- Fraunhofer-Institute for Cell Therapy and Immunology, Perlickstr. 1, D-04103 Leipzig, Germany
- Translational Centre for Regenerative Medicine, University of Leipzig, Philipp-Rosenthal-Str. 55, D-04103 Leipzig, Germany
| | - Dominik Michalski
- Department of Neurology, University of Leipzig, Liebigstr. 20, D-04103, Leipzig Germany
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Levi H, Schoknecht K, Prager O, Chassidim Y, Weissberg I, Serlin Y, Friedman A. Stimulation of the sphenopalatine ganglion induces reperfusion and blood-brain barrier protection in the photothrombotic stroke model. PLoS One 2012; 7:e39636. [PMID: 22745798 PMCID: PMC3382129 DOI: 10.1371/journal.pone.0039636] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2012] [Accepted: 05/27/2012] [Indexed: 01/22/2023] Open
Abstract
Purpose The treatment of stroke remains a challenge. Animal studies showing that electrical stimulation of the sphenopalatine ganglion (SPG) exerts beneficial effects in the treatment of stroke have led to the initiation of clinical studies. However, the detailed effects of SPG stimulation on the injured brain are not known. Methods The effect of acute SPG stimulation was studied by direct vascular imaging, fluorescent angiography and laser Doppler flowmetry in the sensory motor cortex of the anaesthetized rat. Focal cerebral ischemia was induced by the rose bengal (RB) photothrombosis method. In chronic experiments, SPG stimulation, starting 15 min or 24 h after photothrombosis, was given for 3 h per day on four consecutive days. Structural damage was assessed using histological and immunohistochemical methods. Cortical functions were assessed by quantitative analysis of epidural electro-corticographic (ECoG) activity continuously recorded in behaving animals. Results Stimulation induced intensity- and duration-dependent vasodilation and increased cerebral blood flow in both healthy and photothrombotic brains. In SPG-stimulated rats both blood brain-barrier (BBB) opening, pathological brain activity and lesion volume were attenuated compared to untreated stroke animals, with no apparent difference in the glial response surrounding the necrotic lesion. Conclusion SPG-stimulation in rats induces vasodilation of cortical arterioles, partial reperfusion of the ischemic lesion, and normalization of brain functions with reduced BBB dysfunction and stroke volume. These findings support the potential therapeutic effect of SPG stimulation in focal cerebral ischemia even when applied 24 h after stroke onset and thus may extend the therapeutic window of currently administered stroke medications.
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Affiliation(s)
- Haviv Levi
- Departments of Physiology and Neurobiology, Zlotowski Center for Neuroscience, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Karl Schoknecht
- Institute of Neurophysiology, Neurocure Research Center, Charité Universitätsmedizin, Berlin, Germany
| | - Ofer Prager
- Departments of Physiology and Neurobiology, Zlotowski Center for Neuroscience, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Yoash Chassidim
- Departments of Physiology and Neurobiology, Zlotowski Center for Neuroscience, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Itai Weissberg
- Departments of Physiology and Neurobiology, Zlotowski Center for Neuroscience, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Yonatan Serlin
- Departments of Physiology and Neurobiology, Zlotowski Center for Neuroscience, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Alon Friedman
- Departments of Physiology and Neurobiology, Zlotowski Center for Neuroscience, Ben-Gurion University of the Negev, Beer-Sheva, Israel
- Institute of Neurophysiology, Neurocure Research Center, Charité Universitätsmedizin, Berlin, Germany
- * E-mail:
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Stoll G, Basse-Lüsebrink T, Weise G, Jakob P. Visualization of inflammation using19F-magnetic resonance imaging and perfluorocarbons. WILEY INTERDISCIPLINARY REVIEWS-NANOMEDICINE AND NANOBIOTECHNOLOGY 2012; 4:438-47. [DOI: 10.1002/wnan.1168] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
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Weise G, Basse-Lüsebrink TC, Kleinschnitz C, Kampf T, Jakob PM, Stoll G. In vivo imaging of stepwise vessel occlusion in cerebral photothrombosis of mice by 19F MRI. PLoS One 2011; 6:e28143. [PMID: 22194810 PMCID: PMC3240623 DOI: 10.1371/journal.pone.0028143] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2011] [Accepted: 11/02/2011] [Indexed: 01/20/2023] Open
Abstract
Background 19F magnetic resonance imaging (MRI) was recently introduced as a promising technique for in vivo cell tracking. In the present study we compared 19F MRI with iron-enhanced MRI in mice with photothrombosis (PT) at 7 Tesla. PT represents a model of focal cerebral ischemia exhibiting acute vessel occlusion and delayed neuroinflammation. Methods/Principal Findings Perfluorocarbons (PFC) or superparamagnetic iron oxide particles (SPIO) were injected intravenously at different time points after photothrombotic infarction. While administration of PFC directly after PT induction led to a strong 19F signal throughout the entire lesion, two hours delayed application resulted in a rim-like 19F signal at the outer edge of the lesion. These findings closely resembled the distribution of signal loss on T2-weighted MRI seen after SPIO injection reflecting intravascular accumulation of iron particles trapped in vessel thrombi as confirmed histologically. By sequential administration of two chemically shifted PFC compounds 0 and 2 hours after illumination the different spatial distribution of the 19F markers (infarct core/rim) could be visualized in the same animal. When PFC were applied at day 6 the fluorine marker was only detected after long acquisition times ex vivo. SPIO-enhanced MRI showed slight signal loss in vivo which was much more prominent ex vivo indicative for neuroinflammation at this late lesion stage. Conclusion Our study shows that vessel occlusion can be followed in vivo by 19F and SPIO-enhanced high-field MRI while in vivo imaging of neuroinflammation remains challenging. The timing of contrast agent application was the major determinant of the underlying processes depicted by both imaging techniques. Importantly, sequential application of different PFC compounds allowed depiction of ongoing vessel occlusion from the core to the margin of the ischemic lesions in a single MRI measurement.
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Affiliation(s)
- Gesa Weise
- Department of Neurology, University of Würzburg, Würzburg, Germany
- Interdisciplinary Center for Clinical Research Würzburg, University of Würzburg, Würzburg, Germany
| | - Thomas C. Basse-Lüsebrink
- Department of Neurology, University of Würzburg, Würzburg, Germany
- Department of Physics, EPV, University of Würzburg, Würzburg, Germany
- Interdisciplinary Center for Clinical Research Würzburg, University of Würzburg, Würzburg, Germany
| | | | - Thomas Kampf
- Department of Physics, EPV, University of Würzburg, Würzburg, Germany
| | - Peter M. Jakob
- Department of Physics, EPV, University of Würzburg, Würzburg, Germany
- Interdisciplinary Center for Clinical Research Würzburg, University of Würzburg, Würzburg, Germany
| | - Guido Stoll
- Department of Neurology, University of Würzburg, Würzburg, Germany
- Interdisciplinary Center for Clinical Research Würzburg, University of Würzburg, Würzburg, Germany
- * E-mail:
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Palmer AM. Immunomodulatory medicines for multiple sclerosis: Progress and prospects. Drug Dev Res 2011. [DOI: 10.1002/ddr.20476] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Broux B, Pannemans K, Zhang X, Markovic-Plese S, Broekmans T, Eijnde BO, Van Wijmeersch B, Somers V, Geusens P, van der Pol S, van Horssen J, Stinissen P, Hellings N. CX(3)CR1 drives cytotoxic CD4(+)CD28(-) T cells into the brain of multiple sclerosis patients. J Autoimmun 2011; 38:10-9. [PMID: 22123179 DOI: 10.1016/j.jaut.2011.11.006] [Citation(s) in RCA: 101] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2011] [Revised: 11/10/2011] [Accepted: 11/12/2011] [Indexed: 10/25/2022]
Abstract
Immunosenescence, or ageing of the immune system, contributes to the increased morbidity and mortality seen in the elderly population. Premature immunosenescence is shown to occur in a subgroup of patients with autoimmune diseases. One of the main characteristics of immunosenescence is the expansion of CD4(+)CD28(-) T cells in the blood. In this study, we investigate the potential contribution of these cells to disease processes in a subgroup of multiple sclerosis (MS) and rheumatoid arthritis (RA) patients. Characterization of CD4(+)CD28(-) T cells in patients and healthy controls reveals that they have an inflammation-seeking effector-memory T cell phenotype with cytotoxic properties, as they expel cytotoxic granules in response to a polyclonal stimulus or MS-related autoantigens. We identify CX(3)CR1, the fractalkine receptor, as a selective marker to discriminate CD4(+)CD28(-) T cells from their CD4(+)CD28(+) counterparts. CX(3)CR1 expression enables CD4(+)CD28(-) T cells to migrate towards a fractalkine gradient in vitro. In addition, we find increased levels of fractalkine in the cerebrospinal fluid and inflammatory lesions of MS patients. We demonstrate for the first time that CD4(+)CD28(-) T cells accumulate in MS lesions of a subgroup of patients. Moreover, we have indications that these cells are cytotoxic in the target tissue. Overall, our findings suggest that CD4(+)CD28(-) T cells migrate in response to a chemotactic gradient of fractalkine to sites of inflammation, where they contribute to the inflammatory processes in a subgroup of patients with MS and RA.
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Affiliation(s)
- Bieke Broux
- Hasselt University, Biomedical Research Institute and transnationale Universiteit Limburg, School of Life Sciences, Agoralaan, Building C, 3590 Diepenbeek, Belgium.
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Karetko-Sysa M, Skangiel-Kramska J, Nowicka D. Disturbance of perineuronal nets in the perilesional area after photothrombosis is not associated with neuronal death. Exp Neurol 2011; 231:113-26. [PMID: 21683696 DOI: 10.1016/j.expneurol.2011.05.022] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2011] [Revised: 04/26/2011] [Accepted: 05/22/2011] [Indexed: 11/28/2022]
Abstract
Perineuronal nets (PNNs) are a condensed form of extracellular matrix that covers the surface of a subset of neurons. Their presence limits neuronal plasticity and may protect neurons against harmful agents. Here we analyzed the relationship between spatiotemporal changes in PNN expression and cell death markers after focal cortical photothrombotic stroke in rats. We registered a substantial decrease in PNN density using Wisteria floribunda agglutinin staining and CAT-315 and brevican immunoreactivity; the decrease occurred not only in the lesion core but also in the perilesional and remote cortex as well as in homotopic contralateral cortical regions. Fluoro Jade C and TUNEL staining in perilesional and remote areas, however, showed a low density of dying cells. Our results suggest that the PNN reduction was not a result of cellular death and could be considered an attempt to create conditions favorable for synaptic remodeling.
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Affiliation(s)
- Magdalena Karetko-Sysa
- Department of Molecular and Cellular Neurobiology, The Nencki Institute of Experimental Biology, Warsaw, Poland
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Weissberg I, Reichert A, Heinemann U, Friedman A. Blood-brain barrier dysfunction in epileptogenesis of the temporal lobe. EPILEPSY RESEARCH AND TREATMENT 2011; 2011:143908. [PMID: 22937228 PMCID: PMC3420538 DOI: 10.1155/2011/143908] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/11/2010] [Accepted: 03/14/2011] [Indexed: 01/16/2023]
Abstract
Epilepsy of the temporal lobe (TLE) is the most common form of focal epilepsy, and in adults, it most frequently develops after injury. However, the mechanisms by which a normal functioning brain turns into an epileptic one still remain obscure. Recent studies point to vascular involvement and particularly blood-brain barrier (BBB) dysfunction in the development of epilepsy. The BBB is a specialized structure which functions to control the neuronal extracellular milieu. BBB dysfunction is found in many diseases of the central nervous system, including stroke, traumatic injuries, tumors and infections. Interestingly, all these insults may initiate an epileptogenic process which eventually leads to spontaneous, recurrent seizures. This epileptogenic time frame usually lasts weeks, months, or even years in man, and days to weeks in rodents and may serve as a "window of opportunity" for the prevention of epilepsy. However, no prevention strategy exists, stressing the importance of research into the mechanisms of epileptogenesis. Here, we will underscore recent experiments suggesting that BBB dysfunction directly induces epileptogenesis. We will provide new evidence to support the hypothesis that BBB breakdown and specifically exposure of temporal lobe structures to the most common serum protein, albumin, is sufficient to induce epileptogenesis.
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Affiliation(s)
- Itai Weissberg
- Departments of Physiology and Neurobiology, Ben-Gurion University of the Negev, Beersheva 84105, Israel
| | - Aljoscha Reichert
- Neurocure Research Center, Institute of Neurophysiology, Charité Universitätsmedizin, Berlin 10117, Germany
| | - Uwe Heinemann
- Neurocure Research Center, Institute of Neurophysiology, Charité Universitätsmedizin, Berlin 10117, Germany
| | - Alon Friedman
- Departments of Physiology and Neurobiology, Ben-Gurion University of the Negev, Beersheva 84105, Israel
- Neurocure Research Center, Institute of Neurophysiology, Charité Universitätsmedizin, Berlin 10117, Germany
- Biomedical Engineering, Ben-Gurion University of the Negev, Beersheva 84105, Israel
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Pillai DR, Heidemann RM, Kumar P, Shanbhag N, Lanz T, Dittmar MS, Sandner B, Beier CP, Weidner N, Greenlee MW, Schuierer G, Bogdahn U, Schlachetzki F. Comprehensive small animal imaging strategies on a clinical 3 T dedicated head MR-scanner; adapted methods and sequence protocols in CNS pathologies. PLoS One 2011; 6:e16091. [PMID: 21326876 PMCID: PMC3034718 DOI: 10.1371/journal.pone.0016091] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2010] [Accepted: 12/09/2010] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Small animal models of human diseases are an indispensable aspect of pre-clinical research. Being dynamic, most pathologies demand extensive longitudinal monitoring to understand disease mechanisms, drug efficacy and side effects. These considerations often demand the concomitant development of monitoring systems with sufficient temporal and spatial resolution. METHODOLOGY AND RESULTS This study attempts to configure and optimize a clinical 3 Tesla magnetic resonance scanner to facilitate imaging of small animal central nervous system pathologies. The hardware of the scanner was complemented by a custom-built, 4-channel phased array coil system. Extensive modification of standard sequence protocols was carried out based on tissue relaxometric calculations. Proton density differences between the gray and white matter of the rodent spinal cord along with transverse relaxation due to magnetic susceptibility differences at the cortex and striatum of both rats and mice demonstrated statistically significant differences. The employed parallel imaging reconstruction algorithms had distinct properties dependent on the sequence type and in the presence of the contrast agent. The attempt to morphologically phenotype a normal healthy rat brain in multiple planes delineated a number of anatomical regions, and all the clinically relevant sequels following acute cerebral ischemia could be adequately characterized. Changes in blood-brain-barrier permeability following ischemia-reperfusion were also apparent at a later time. Typical characteristics of intra-cerebral haemorrhage at acute and chronic stages were also visualized up to one month. Two models of rodent spinal cord injury were adequately characterized and closely mimicked the results of histological studies. In the employed rodent animal handling system a mouse model of glioblastoma was also studied with unequivocal results. CONCLUSIONS The implemented customizations including extensive sequence protocol modifications resulted in images of high diagnostic quality. These results prove that lack of dedicated animal scanners shouldn't discourage conventional small animal imaging studies.
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Affiliation(s)
- Deepu R. Pillai
- Department of Neurology, Regensburg University Medical Centre, Regensburg, Germany
- Department of Genetics and Neurobiology, Biozentrum, Julius-Maximilians-Universität Würzburg, Würzburg, Germany
| | - Robin M. Heidemann
- Department of Neurophysics, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany
- Siemens Healthcare Sector, Erlangen, Germany
| | - Praveen Kumar
- Department of Neurology, Regensburg University Medical Centre, Regensburg, Germany
- Department of Neurology, University Medical Centre, RWTH Aachen, Aachen, Germany
| | - Nagesh Shanbhag
- Department of Neurology, Regensburg University Medical Centre, Regensburg, Germany
| | - Titus Lanz
- RAPID Biomedical GmbH, Würzburg-Rimpar, Germany
| | - Michael S. Dittmar
- Department of Anaesthesiology, Regensburg University Medical Centre, Regensburg, Germany
| | - Beatrice Sandner
- Department of Neurology, Regensburg University Medical Centre, Regensburg, Germany
| | - Christoph P. Beier
- Department of Neurology, Regensburg University Medical Centre, Regensburg, Germany
- Department of Neurology, University Medical Centre, RWTH Aachen, Aachen, Germany
| | - Norbert Weidner
- Department of Neurology, Regensburg University Medical Centre, Regensburg, Germany
- Institute for Paraplegia, University of Heidelberg, Heidelberg, Germany
| | - Mark W. Greenlee
- Institute for Experimental Psychology, University of Regensburg, Regensburg, Germany
| | - Gerhard Schuierer
- Center for Neuroradiology, Regensburg University Medical Centre and Bezirksklinikum Regensburg, Regensburg, Germany
| | - Ulrich Bogdahn
- Department of Neurology, Regensburg University Medical Centre, Regensburg, Germany
| | - Felix Schlachetzki
- Department of Neurology, Regensburg University Medical Centre, Regensburg, Germany
- * E-mail:
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Wuerfel E, Infante-Duarte C, Glumm R, Wuerfel JT. Gadofluorine M-enhanced MRI shows involvement of circumventricular organs in neuroinflammation. J Neuroinflammation 2010; 7:70. [PMID: 20955604 PMCID: PMC2978145 DOI: 10.1186/1742-2094-7-70] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2010] [Accepted: 10/18/2010] [Indexed: 01/06/2023] Open
Abstract
Background Circumventricular organs (CVO) are cerebral areas with incomplete endothelial blood-brain barrier (BBB) and therefore regarded as "gates to the brain". During inflammation, they may exert an active role in determining immune cell recruitment into the brain. Methods In a longitudinal study we investigated in vivo alterations of CVO during neuroinflammation, applying Gadofluorine M- (Gf) enhanced magnetic resonance imaging (MRI) in experimental autoimmune encephalomyelitis, an animal model of multiple sclerosis. SJL/J mice were monitored by Gadopentate dimeglumine- (Gd-DTPA) and Gf-enhanced MRI after adoptive transfer of proteolipid-protein-specific T cells. Mean Gf intensity ratios were calculated individually for different CVO and correlated to the clinical disease course. Subsequently, the tissue distribution of fluorescence-labeled Gf as well as the extent of cellular inflammation was assessed in corresponding histological slices. Results We could show that the Gf signal intensity of the choroid plexus, the subfornicular organ and the area postrema increased significantly during experimental autoimmune encephalomyelitis, correlating with (1) disease severity and (2) the delay of disease onset after immunization. For the choroid plexus, the extent of Gf enhancement served as a diagnostic criterion to distinguish between diseased and healthy control mice with a sensitivity of 89% and a specificity of 80%. Furthermore, Gf improved the detection of lesions, being particularly sensitive to optic neuritis. In correlated histological slices, Gf initially accumulated in the extracellular matrix surrounding inflammatory foci and was subsequently incorporated by macrophages/microglia. Conclusion Gf-enhanced MRI provides a novel highly sensitive technique to study cerebral BBB alterations. We demonstrate for the first time in vivo the involvement of CVO during the development of neuroinflammation.
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Affiliation(s)
- Eva Wuerfel
- Experimental and Clinical Research Center, Charité - University Medicine Berlin, Charitéplatz 1, 10117 Berlin, Germany.
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Abstract
PURPOSE OF REVIEW Inflammation is an important component not only in autoimmune but also in ischemic/degenerative disorders of the central nervous system (CNS). We here review magnetic resonance imaging (MRI)-based techniques to visualize neuroinflammation in vivo. RECENT FINDINGS Iron oxide particles such as superparamagnetic iron oxide (SPIO) and ultrasmall SPIO (USPIO) are phagocytosed by hematogeneous macrophages upon systemic application into the circulation and allow in-vivo tracking of infiltration to the CNS due to their paramagnetic effect by MRI in experimental CNS disorders, and also in multiple sclerosis and stroke. Thereby, the size and application scheme of the iron particles is critical for interpretation of the MRI data which in addition to neuroinflammation involves passive diffusion and intravascular trapping. Targeting of inflammatory, activation-dependent enzymes such as myeloperoxidase or immune function molecules by MR contrast agents represents a molecular approach to visualize critical steps of lesion development caused by neuroinflammation. Clinical studies with Gd-DTPA in conjunction with experimental investigations employing more sensitive MR contrast agents such as gadofluorine revealed that breakdown of the blood-brain barrier and SPIO/USPIO-related macrophage infiltration occur mostly independently. SUMMARY Cellular and targeted molecular MRI provides important insights into the dynamics of neuroinflammation.
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Different strokes for different folks: the rich diversity of animal models of focal cerebral ischemia. J Cereb Blood Flow Metab 2010; 30:1412-31. [PMID: 20485296 PMCID: PMC2949237 DOI: 10.1038/jcbfm.2010.66] [Citation(s) in RCA: 218] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
No single animal model is able to encompass all of the variables known to affect human ischemic stroke. This review highlights the major strengths and weaknesses of the most commonly used animal models of acute ischemic stroke in the context of matching model and experimental aim. Particular emphasis is placed on the relationships between outcome and underlying vascular variability, physiologic control, and use of models of comorbidity. The aim is to provide, for novice and expert alike, an overview of the key controllable determinants of experimental stroke outcome to help ensure the most effective application of animal models to translational research.
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Pillai DR, Dittmar MS, Baldaranov D, Heidemann RM, Henning EC, Schuierer G, Bogdahn U, Schlachetzki F. Cerebral ischemia-reperfusion injury in rats--a 3 T MRI study on biphasic blood-brain barrier opening and the dynamics of edema formation. J Cereb Blood Flow Metab 2009; 29:1846-55. [PMID: 19654585 PMCID: PMC2848453 DOI: 10.1038/jcbfm.2009.106] [Citation(s) in RCA: 119] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Serial magnetic resonance imaging (MRI) was performed to investigate the temporal and spatial relationship between the biphasic nature of blood-brain barrier (BBB) opening and, in parallel, edema formation after ischemia-reperfusion (I/R) injury in rats. T(2)-weighted imaging combined with T(2)-relaxometry, mainly for edema assessment, was performed at 1 h after ischemia, after reperfusion, and at 4, 24 and 48 h after reperfusion. T(1)-weighted imaging was performed before and after gadolinium contrast at the last three time points to assess BBB integrity. The biphasic course of BBB opening with a significant reduction in BBB permeability at 24 h after reperfusion, associated with a progressive expansion of leaky BBB volume, was accompanied by a peak ipsilateral edema formation. In addition, at 4 h after reperfusion, edema formation could also be detected at the contralateral striatum as determined by the elevated T(2)-values that persisted to varying degrees, indicative of widespread effects of I/R injury. The observations of this study may indicate a dynamic temporal shift in the mechanisms responsible for biphasic BBB permeability changes, with complex relations to edema formation. Stroke therapy aimed at vasogenic edema and drug delivery for neuroprotection may also be guided according to the functional status of the BBB, and these findings have to be confirmed in human stroke.
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Affiliation(s)
- Deepu R Pillai
- Department of Neurology, Regensburg University Medical Center, Regensburg, Germany
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49
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Spatial diversity of blood-brain barrier alteration and macrophage invasion in experimental autoimmune encephalomyelitis: a comparative MRI study. Exp Neurol 2009; 220:207-11. [PMID: 19733560 DOI: 10.1016/j.expneurol.2009.08.027] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2009] [Revised: 08/07/2009] [Accepted: 08/28/2009] [Indexed: 11/20/2022]
Abstract
Inflammation plays a central role in the development of numerous disorders of the central nervous system (CNS) such as multiple sclerosis (MS). For a long time it was assumed that recruitment of macrophages into the CNS and breakdown of the blood-brain barrier (BBB) are closely linked. In the present study we challenge this concept. We used small superparamagnetic iron oxide particles (SPIO)-enhanced T2-weighted (T2-w) magnetic resonance imaging (MRI) on a routine 1.5 T MRI unit to follow macrophage infiltration in experimental autoimmune encephalomyelitis (EAE), the animal model of MS. After an initial SPIO-enhanced MRI, gadofluorine M (Gf), an experimental contrast agent which proved to be more sensitive in detecting BBB leakage than gadolinium (Gd)-DTPA (Bendszus, M., Ladewig, G., Jestaedt, L., Misselwitz, B., Solymosi, L., Toyka, K.V., Stoll, G., Gadofluorine-M enhancement allows more sensitive detection of inflammatory CNS lesions than T2-w imaging: a quantitative MRI study. Brain 2008; 1-12), was applied to the same animals followed by a second scan. Areas with SPIO-induced signal loss on T2-w MRI indicative of recent macrophage infiltration were matched with areas showing Gf enhancement as a measure of BBB disturbance. Overall 87 EAE lesions showed iron-related signal loss, while 57 lesions showed Gf enhancement. By direct comparison we could detect concomitant SPIO-induced signal loss and Gf enhancement only in a small minority of lesions. In conclusion, our findings show macrophage infiltration in the CNS during EAE in areas with a closed BBB for humoral factors. This holds true despite the use of a more sensitive MR contrast agent for BBB disruption than Gd-DTPA. Our experimental observations may have implications for disease monitoring in MS patients by MRI which guides treatment decisions.
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50
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Prager O, Chassidim Y, Klein C, Levi H, Shelef I, Friedman A. Dynamic in vivo imaging of cerebral blood flow and blood-brain barrier permeability. Neuroimage 2009; 49:337-44. [PMID: 19682584 DOI: 10.1016/j.neuroimage.2009.08.009] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2009] [Revised: 07/01/2009] [Accepted: 08/05/2009] [Indexed: 12/19/2022] Open
Abstract
The brain is characterized by an extremely rich blood supply, regulated by changes in blood vessel diameter and blood flow, depending on metabolic demands. The blood-brain barrier (BBB)-a functional and structural barrier separating the intravascular and neuropil compartments-characterizes the brain's vascular bed and is essential for normal brain functions. Disruptions to the regional cerebral blood supply, to blood drainage and to BBB properties have been described in most common neurological disorders, but there is a lack of quantitative methods for assessing blood flow dynamics and BBB permeability in small blood vessels under both physiological and pathological conditions. Here, we present a quantitative image analysis approach that allows the characterization of relative changes in the regional cerebral blood flow (rCBF) and BBB properties in small surface cortical vessels. In experiments conducted using the open window technique in rats, a fluorescent tracer was injected into the tail vein, and images of the small vessels at the surface of the cortex were taken using a fast CCD camera. Pixel-based image analysis included registration and characterization of the changes in fluorescent intensity, followed by cluster analysis. This analysis enabled the characterization of rCBF in small arterioles and venules and changes in BBB permeability. The method was implemented successfully under experimental conditions, including increased rCBF induced by neural stimulation, bile salt-induced BBB breakdown, and photothrombosis-mediated local ischemia. The new approach may be used to study changes in rCBF, neurovascular coupling and BBB permeability under normal and pathological brain conditions.
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Affiliation(s)
- Ofer Prager
- Department of Physiology, Soroka University Medical Center and Zlotowski Center for Neuroscience, Ben-Gurion University of the Negev, Beer-Sheva, Israel
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