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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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Li C, Shi L, Wang Y, Peng C, Wu L, Zhang Y, Du Z. High-fat diet exacerbates lead-induced blood-brain barrier disruption by disrupting tight junction integrity. ENVIRONMENTAL TOXICOLOGY 2021; 36:1412-1421. [PMID: 33749115 DOI: 10.1002/tox.23137] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Revised: 03/08/2021] [Accepted: 03/13/2021] [Indexed: 06/12/2023]
Abstract
Environmental exposure to lead (Pb) can damage to the central nervous system (CNS) in humans. High-fat diet (HFD) also has been suggested to impair neurocognitive function. Blood-brain barrier (BBB) is a rigorous permeability barrier for maintaining homeostasis of CNS. The damage of BBB caused by tight junctions (TJs) disruption is central to the etiology of various CNS disorders. This study aimed to investigate whether HFD could exacerbate Pb exposure induced the destruction of BBB integrity by TJs disruption. To this end, we measured cell viability assay, trans-endothelial electrical resistance assay, horseradish peroxidase flux measurement, Western blot analysis, and immunofluorescence experiments. The results showed that palmitic acid (PA), the most common saturated fatty acid found in the human body, can increase the permeability of the BBB in vitro which formed in bEnd.3 cells induced by Pb exposure, and decrease the expression of TJs, such as zonula occludins-1 (ZO-1) and occludin. Besides, we found that PA could promote the up-regulation of matrix metalloproteinase (MMP)-9 expression and activate the c-Jun N-terminal kinase (JNK) pathway induced by Pb. MMP-9 inhibitor or JNK inhibitor could increase BBB integrity and up-regulate the expressions of ZO-1 and occludin after treatment, respectively. Moreover, the JNK inhibitor could down-regulate the expression of MMP-9. In conclusion, these results suggested that HFD exacerbates Pb-induced BBB disruption by disrupting TJs integrity. This may be because PA promotes the activation of JNK pathway and then up-regulated the expression of MMP-9 after Pb-exposure. It is suggested that people with HFD exposed to environmental Pb may cause more serious damage to the CNS.
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Affiliation(s)
- Chao Li
- School of Public Health, North China University of Science and Technology, Tangshan, Hebei, China
- Shandong Academy of Occupational Health and Occupational Medicine, Shandong First Medical University & Shandong Academy of Medical Sciences, Ji'nan, Shandong, China
| | - Liang Shi
- Biomedical Sciences College & Shandong Medicinal Biotechnology Centre, Shandong First Medical University & Shandong Academy of Medical Sciences, Ji'nan, Shandong, China
| | - Yuanbo Wang
- Institute of Plastic Surgery, Weifang Medical University, Weifang, Shandong, China
| | - Cheng Peng
- Shandong Academy of Occupational Health and Occupational Medicine, Shandong First Medical University & Shandong Academy of Medical Sciences, Ji'nan, Shandong, China
- Queensland Alliance for Environmental Health Sciences (QAEHS), The University of Queensland, Brisbane, Queensland, Australia
| | - Lei Wu
- School of Public Health, North China University of Science and Technology, Tangshan, Hebei, China
| | - Yanshu Zhang
- School of Public Health, North China University of Science and Technology, Tangshan, Hebei, China
- Laboratory Animal Center, North China University of Science and Technology, Tangshan, Hebei, China
| | - Zhongjun Du
- Shandong Academy of Occupational Health and Occupational Medicine, Shandong First Medical University & Shandong Academy of Medical Sciences, Ji'nan, Shandong, China
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3
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Chang SK, Kim J, Lee D, Yoo CH, Jin S, Rhee HY, Ryu CW, Lee JK, Cho H, Jahng GH. Mapping of microvascular architecture in the brain of an Alzheimer's disease mouse model using MRI. NMR IN BIOMEDICINE 2021; 34:e4481. [PMID: 33590547 DOI: 10.1002/nbm.4481] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2020] [Revised: 11/15/2020] [Accepted: 01/08/2021] [Indexed: 06/12/2023]
Abstract
Increasing evidence suggests that alterations in cerebral microvasculature play a critical role in the pathogenesis of Alzheimer's disease (AD). The objective of this study was to characterize and evaluate the cerebral microvascular architecture of AD transgenic (Tg) mice and compare it with that of non-Tg mice using brain microvascular indices obtained by MRI. Seven non-Tg mice and 10 5xFAD Tg mice were scanned using a 7-T animal MRI system to measure the transverse relaxation rates of R2 and R2* before and after the injection of the monocrystalline iron oxide nanoparticle contrast agent. After calculating ΔR2* and ΔR2, the vessel size index (VSI), mean vessel diameter (mVD), mean vessel density, mean vessel-weighted image (MvWI) and blood volume fraction (BVf) were mapped. Voxel-based analyses and region of interest (ROI)-based analyses were performed to compare the indices of the non-Tg and Tg groups. Voxel comparisons showed that BVf, mVD, VSI and MvWI were greater in the Tg group than in the non-Tg group. Additionally, the ROI-based analysis showed that ΔR2*, BVf, mVD, MvWI and VSI increased in several brain regions of the Tg group compared with those in the non-Tg group. VSI and mVD increased in Tg mice; these findings indicated microvascular disruption in the brain that could be related to damage to the neurovascular unit in AD caused by cerebral amyloid angiopathy.
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Affiliation(s)
- Suk-Ki Chang
- Hallym University Medical Center, Hwasung, Republic of Korea
| | - JeongYeong Kim
- Department of Physics, Undergraduate School, Kyung Hee University, Seoul, Republic of Korea
| | - DongKyu Lee
- Department of Biomedical Engineering, Ulsan National Institute of Science and Technology, Ulsan, Republic of Korea
| | - Chang Hyun Yoo
- Department of Physics, Graduate School, Kyung Hee University, Seoul, Republic of Korea
| | - Seokha Jin
- Department of Biomedical Engineering, Ulsan National Institute of Science and Technology, Ulsan, Republic of Korea
| | - Hak Young Rhee
- Department of Neurology, Kyung Hee University Hospital at Gangdong, College of Medicine, Kyung Hee University, Seoul, Republic of Korea
| | - Chang-Woo Ryu
- Department of Radiology, Kyung Hee University Hospital at Gangdong, College of Medicine, Kyung Hee University, Seoul, Republic of Korea
| | - Jong Kil Lee
- Department of Pharmacy, College of Pharmacy, Kyung Hee University, Seoul, Republic of Korea
| | - HyungJoon Cho
- Department of Biomedical Engineering, Ulsan National Institute of Science and Technology, Ulsan, Republic of Korea
| | - Geon-Ho Jahng
- Department of Radiology, Kyung Hee University Hospital at Gangdong, College of Medicine, Kyung Hee University, Seoul, Republic of Korea
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Bladt P, den Dekker AJ, Clement P, Achten E, Sijbers J. The costs and benefits of estimating T 1 of tissue alongside cerebral blood flow and arterial transit time in pseudo-continuous arterial spin labeling. NMR IN BIOMEDICINE 2020; 33:e4182. [PMID: 31736223 PMCID: PMC7685117 DOI: 10.1002/nbm.4182] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Revised: 07/09/2019] [Accepted: 08/14/2019] [Indexed: 06/10/2023]
Abstract
Multi-post-labeling-delay pseudo-continuous arterial spin labeling (multi-PLD PCASL) allows for absolute quantification of the cerebral blood flow (CBF) as well as the arterial transit time (ATT). Estimating these perfusion parameters from multi-PLD PCASL data is a non-linear inverse problem, which is commonly tackled by fitting the single-compartment model (SCM) for PCASL, with CBF and ATT as free parameters. The longitudinal relaxation time of tissue T1t is an important parameter in this model, as it governs the decay of the perfusion signal entirely upon entry in the imaging voxel. Conventionally, T1t is fixed to a population average. This approach can cause CBF quantification errors, as T1t can vary significantly inter- and intra-subject. This study compares the impact on CBF quantification, in terms of accuracy and precision, of either fixing T1t , the conventional approach, or estimating it alongside CBF and ATT. It is shown that the conventional approach can cause a significant bias in CBF. Indeed, simulation experiments reveal that if T1t is fixed to a value that is 10% off its true value, this may already result in a bias of 15% in CBF. On the other hand, as is shown by both simulation and real data experiments, estimating T1t along with CBF and ATT results in a loss of CBF precision of the same order, even if the experiment design is optimized for the latter estimation problem. Simulation experiments suggest that an optimal balance between accuracy and precision of CBF estimation from multi-PLD PCASL data can be expected when using the two-parameter estimator with a fixed T1t value between population averages of T1t and the longitudinal relaxation time of blood T1b .
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Affiliation(s)
- Piet Bladt
- imec‐Vision Lab, Department of PhysicsUniversity of Antwerp2610AntwerpBelgium
| | - Arnold J. den Dekker
- imec‐Vision Lab, Department of PhysicsUniversity of Antwerp2610AntwerpBelgium
- Delft Center for Systems and ControlDelft University of Technology2628 CDDelftThe Netherlands
| | - Patricia Clement
- Department of Radiology and Nuclear MedicineGhent University9000GhentBelgium
| | - Eric Achten
- Department of Radiology and Nuclear MedicineGhent University9000GhentBelgium
| | - Jan Sijbers
- imec‐Vision Lab, Department of PhysicsUniversity of Antwerp2610AntwerpBelgium
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5
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Cloyd RA, Koren SA, Abisambra JF. Manganese-Enhanced Magnetic Resonance Imaging: Overview and Central Nervous System Applications With a Focus on Neurodegeneration. Front Aging Neurosci 2018; 10:403. [PMID: 30618710 PMCID: PMC6300587 DOI: 10.3389/fnagi.2018.00403] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2018] [Accepted: 11/23/2018] [Indexed: 12/16/2022] Open
Abstract
Manganese-enhanced magnetic resonance imaging (MEMRI) rose to prominence in the 1990s as a sensitive approach to high contrast imaging. Following the discovery of manganese conductance through calcium-permeable channels, MEMRI applications expanded to include functional imaging in the central nervous system (CNS) and other body systems. MEMRI has since been employed in the investigation of physiology in many animal models and in humans. Here, we review historical perspectives that follow the evolution of applied MRI research into MEMRI with particular focus on its potential toxicity. Furthermore, we discuss the more current in vivo investigative uses of MEMRI in CNS investigations and the brief but decorated clinical usage of chelated manganese compound mangafodipir in humans.
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Affiliation(s)
- Ryan A Cloyd
- Department of Physiology, University of Kentucky, Lexington, KY, United States.,College of Medicine, University of Kentucky, Lexington, KY, United States.,Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY, United States
| | - Shon A Koren
- Department of Physiology, University of Kentucky, Lexington, KY, United States.,Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY, United States.,Department of Neuroscience & Center for Translational Research in Neurodegenerative Disease, University of Florida, Gainesville, FL, United States
| | - Jose F Abisambra
- Department of Physiology, University of Kentucky, Lexington, KY, United States.,Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY, United States.,Department of Neuroscience & Center for Translational Research in Neurodegenerative Disease, University of Florida, Gainesville, FL, United States.,Spinal Cord and Brain Injury Research Center, University of Kentucky, Lexington, KY, United States
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6
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Jiang X, Andjelkovic AV, Zhu L, Yang T, Bennett MVL, Chen J, Keep RF, Shi Y. Blood-brain barrier dysfunction and recovery after ischemic stroke. Prog Neurobiol 2017; 163-164:144-171. [PMID: 28987927 DOI: 10.1016/j.pneurobio.2017.10.001] [Citation(s) in RCA: 554] [Impact Index Per Article: 79.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2016] [Revised: 05/30/2017] [Accepted: 10/02/2017] [Indexed: 01/06/2023]
Abstract
The blood-brain barrier (BBB) plays a vital role in regulating the trafficking of fluid, solutes and cells at the blood-brain interface and maintaining the homeostatic microenvironment of the CNS. Under pathological conditions, such as ischemic stroke, the BBB can be disrupted, followed by the extravasation of blood components into the brain and compromise of normal neuronal function. This article reviews recent advances in our knowledge of the mechanisms underlying BBB dysfunction and recovery after ischemic stroke. CNS cells in the neurovascular unit, as well as blood-borne peripheral cells constantly modulate the BBB and influence its breakdown and repair after ischemic stroke. The involvement of stroke risk factors and comorbid conditions further complicate the pathogenesis of neurovascular injury by predisposing the BBB to anatomical and functional changes that can exacerbate BBB dysfunction. Emphasis is also given to the process of long-term structural and functional restoration of the BBB after ischemic injury. With the development of novel research tools, future research on the BBB is likely to reveal promising potential therapeutic targets for protecting the BBB and improving patient outcome after ischemic stroke.
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Affiliation(s)
- Xiaoyan Jiang
- Pittsburgh Institute of Brain Disorders & Recovery and Department of Neurology, University of Pittsburgh, Pittsburgh, PA 15213, USA; State Key Laboratory of Medical Neurobiology, Institute of Brain Sciences and Collaborative Innovation Center for Brain Science, Fudan University, Shanghai 200032, China
| | | | - Ling Zhu
- Pittsburgh Institute of Brain Disorders & Recovery and Department of Neurology, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Tuo Yang
- Pittsburgh Institute of Brain Disorders & Recovery and Department of Neurology, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Michael V L Bennett
- State Key Laboratory of Medical Neurobiology, Institute of Brain Sciences and Collaborative Innovation Center for Brain Science, Fudan University, Shanghai 200032, China; Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Jun Chen
- Pittsburgh Institute of Brain Disorders & Recovery and Department of Neurology, University of Pittsburgh, Pittsburgh, PA 15213, USA; State Key Laboratory of Medical Neurobiology, Institute of Brain Sciences and Collaborative Innovation Center for Brain Science, Fudan University, Shanghai 200032, China
| | - Richard F Keep
- Department of Neurosurgery, University of Michigan, Ann Arbor, MI 48109, USA.
| | - Yejie Shi
- Pittsburgh Institute of Brain Disorders & Recovery and Department of Neurology, University of Pittsburgh, Pittsburgh, PA 15213, USA.
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7
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Kong LL, Wang ZY, Hu JF, Yuan YH, Li H, Chen NH. Inhibition of chemokine-like factor 1 improves blood-brain barrier dysfunction in rats following focal cerebral ischemia. Neurosci Lett 2016; 627:192-8. [DOI: 10.1016/j.neulet.2016.06.003] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2016] [Revised: 05/07/2016] [Accepted: 06/01/2016] [Indexed: 01/30/2023]
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8
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Debacker CS, Daoust A, Köhler S, Voiron J, Warnking JM, Barbier EL. Impact of tissue T 1 on perfusion measurement with arterial spin labeling. Magn Reson Med 2016; 77:1656-1664. [PMID: 27136322 DOI: 10.1002/mrm.26255] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2016] [Revised: 03/18/2016] [Accepted: 04/02/2016] [Indexed: 12/20/2022]
Abstract
PURPOSE Arterial spin labeling (ASL) may provide quantitative maps of cerebral blood flow (CBF). Because labeled water exchanges with tissue water, this study evaluates the influence of tissue T1 on CBF quantification using ASL. METHODS To locally modify T1 , a low dose of manganese (Mn) was intracerebrally injected in one hemisphere of 19 rats (cortex or striatum). Tissue T1 and CBF were mapped using inversion recovery and continuous ASL experiments at 4.7T. RESULTS Mn reduced the tissue T1 by more than 30% but had little impact on other tissue properties as assessed via dynamic susceptibility and diffusion MRI. Using a single-compartment model, the use of a single tissue T1 value yielded a mean relative ipsilateral (Mn-injected) to contralateral (noninjected) CBF difference of -34% in cortex and -22% in striatum tissue. With a T1 map, these values became -7% and +8%, respectively. CONCLUSION A low dose of Mn reduces the tissue T1 without modifying CBF. Heterogeneous T1 impacts the ASL estimate of CBF in a region-dependent way. In animals, and when T1 modifications exceed the accuracy with which the tissue T1 can be determined, an estimate of tissue T1 should be obtained when quantifying CBF with an ASL technique. Magn Reson Med 77:1656-1664, 2017. © 2016 International Society for Magnetic Resonance in Medicine.
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Affiliation(s)
- Clément S Debacker
- INSERM U1216, Grenoble, France.,Université Grenoble Alpes, Grenoble Institut des Neurosciences, GIN, Grenoble, France.,Bruker BioSpin MRI, Ettligen, Germany
| | - Alexia Daoust
- INSERM U1216, Grenoble, France.,Université Grenoble Alpes, Grenoble Institut des Neurosciences, GIN, Grenoble, France
| | | | | | - Jan M Warnking
- INSERM U1216, Grenoble, France.,Université Grenoble Alpes, Grenoble Institut des Neurosciences, GIN, Grenoble, France
| | - Emmanuel L Barbier
- INSERM U1216, Grenoble, France.,Université Grenoble Alpes, Grenoble Institut des Neurosciences, GIN, Grenoble, France
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9
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Phenotyping the central nervous system of the embryonic mouse by magnetic resonance microscopy. Neuroimage 2014; 97:95-106. [PMID: 24769183 DOI: 10.1016/j.neuroimage.2014.04.043] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2013] [Revised: 04/07/2014] [Accepted: 04/13/2014] [Indexed: 11/20/2022] Open
Abstract
Genetic mouse models of neurodevelopmental disorders are being massively generated, but technologies for their high-throughput phenotyping are missing. The potential of high-resolution magnetic resonance imaging (MRI) for structural phenotyping has been demonstrated before. However, application to the embryonic mouse central nervous system has been limited by the insufficient anatomical detail. Here we present a method that combines staining of live embryos with a contrast agent together with MR microscopy after fixation, to provide unprecedented anatomical detail at relevant embryonic stages. By using this method we have phenotyped the embryonic forebrain of Robo1/2(-/-) double mutant mice enabling us to identify most of the well-known anatomical defects in these mutants, as well as novel more subtle alterations. We thus demonstrate the potential of this methodology for a fast and reliable screening of subtle structural abnormalities in the developing mouse brain, as those associated to defects in disease-susceptibility genes of neurologic and psychiatric relevance.
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Gottschalk S, Engelmann J, Rolla GA, Botta M, Parker D, Mishra A. Comparative in vitro studies of MR imaging probes for metabotropic glutamate subtype-5 receptor targeting. Org Biomol Chem 2014; 11:6131-41. [PMID: 23925571 DOI: 10.1039/c3ob41297k] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
A series of magnetic resonance imaging probes has been evaluated to target selectively the metabotropic glutamate receptor subtype 5 (mGluR5). Eight imaging probes based on the contrast agent [Gd·DOTA], previously derived by linking it to a series of specific and selective mGluR5 antagonists, have been extensively tested for their functionality in vitro. The Nuclear Magnetic Relaxation Dispersion (NMRD) profiles of selected probes have been examined via field-cycling relaxometry in the presence and absence of a model protein. The properties of the targeted contrast agents were evaluated using a primary astrocyte model, as these cells mimic the in vivo situation effectively. The probes were non-toxic (up to 200 μM) to these mGluR5 expressing primary cells. Cellular proton longitudinal relaxation rate enhancements of up to 35% were observed by MRI at 200 μM of probe concentration. The antagonistic effect of all compounds was tested using an assay measuring changes of intracellular calcium levels. Furthermore, treatment at two different temperatures (4 °C vs. 37 °C) and of an mGluR5-negative cell line provided further insight into the selectivity and specificity of these probes towards cell surface mGluR5. Finally, two out of eight probes demonstrated an antagonistic effect as well as significant enhancement of receptor mediated cellular relaxation rates, strongly suggesting that they would be viable probes for the mapping of mGluR5 by MRI in vivo.
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Affiliation(s)
- Sven Gottschalk
- High-Field Magnetic Resonance, Max Planck Institute for Biological Cybernetics, Spemannstrasse 41, Tuebingen, D-72076, Germany.
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11
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Detante O, Valable S, de Fraipont F, Grillon E, Barbier EL, Moisan A, Arnaud J, Moriscot C, Segebarth C, Hommel M, Remy C, Richard MJ. Magnetic resonance imaging and fluorescence labeling of clinical-grade mesenchymal stem cells without impacting their phenotype: study in a rat model of stroke. Stem Cells Transl Med 2012. [PMID: 23197812 DOI: 10.5966/sctm.2011-0043] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Human mesenchymal stem cells (hMSCs) have strong potential for cell therapy after stroke. Tracking stem cells in vivo following a graft can provide insight into many issues regarding optimal route and/or dosing. hMSCs were labeled for magnetic resonance imaging (MRI) and histology with micrometer-sized superparamagnetic iron oxides (M-SPIOs) that contained a fluorophore. We assessed whether M-SPIO labeling obtained without the use of a transfection agent induced any cell damage in clinical-grade hMSCs and whether it may be useful for in vivo MRI studies after stroke. M-SPIOs provided efficient intracellular hMSC labeling and did not modify cell viability, phenotype, or in vitro differentiation capacity. Following grafting in a rat model of stroke, labeled hMSCs could be detected using both in vivo MRI and fluorescent microscopy until 4 weeks following transplantation. However, whereas good label stability and unaffected hMSC viability were observed in vitro, grafted hMSCs may die and release iron particles in vivo.
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Affiliation(s)
- Olivier Detante
- Institut National de Santé et de Recherche Médicale, Grenoble, France.
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Calcitonin gene-related peptide prevents blood–brain barrier injury and brain edema induced by focal cerebral ischemia reperfusion. ACTA ACUST UNITED AC 2011; 171:19-25. [DOI: 10.1016/j.regpep.2011.05.014] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2010] [Revised: 05/13/2011] [Accepted: 05/30/2011] [Indexed: 11/21/2022]
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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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Marushima A, Suzuki K, Nagasaki Y, Yoshitomi T, Toh K, Tsurushima H, Hirayama A, Matsumura A. Newly Synthesized Radical-Containing Nanoparticles Enhance Neuroprotection After Cerebral Ischemia-Reperfusion Injury. Neurosurgery 2011; 68:1418-25; discussion 1425-6. [DOI: 10.1227/neu.0b013e31820c02d9] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
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The impact of erythropoietin on short-term changes in phosphorylation of brain protein kinases in a rat model of traumatic brain injury. J Cereb Blood Flow Metab 2010; 30:361-9. [PMID: 19809465 PMCID: PMC2949118 DOI: 10.1038/jcbfm.2009.222] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
We found that recombinant human erythropoietin (rhEPO) reduced significantly the development of brain edema in a rat model of diffuse traumatic brain injury (TBI) (impact-acceleration model). In this study, we investigated the molecular and intracellular changes potentially involved in these immediate effects. Brain tissue nitric oxide (NO) synthesis, phosphorylation level of two protein kinases (extracellular-regulated kinase (ERK)-1/-2 and Akt), and brain water content were measured 1 (H1) and 2 h (H2) after insult. Posttraumatic administration of rhEPO (5,000 IU/kg body weight, intravenously, 30 mins after injury) reduced TBI-induced upregulation of ERK phosphorylation, although it increased Akt phosphorylation at H1. These early molecular changes were associated with a reduction in brain NO synthesis at H1 and with an attenuation of brain edema at H2. Intraventricular administration of the ERK-1/-2 inhibitor, U0126, or the Akt inhibitor, LY294002, before injury showed that ERK was required for brain edema formation, and that rhEPO-induced reduction of edema could involve the ERK pathway. These results were obtained in the absence of any evidence of blood-brain barrier damage on contrast-enhanced magnetic resonance images. The findings of our study indicate that the anti edematous effect of rhEPO could be mediated through an early inhibition of ERK phosphorylation after diffuse TBI.
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Planas AM. Noninvasive Brain Imaging in Small Animal Stroke Models: MRI and PET. NEUROMETHODS 2010. [DOI: 10.1007/978-1-60761-750-1_11] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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