1
|
Koukalova L, Chmelova M, Amlerova Z, Vargova L. Out of the core: the impact of focal ischemia in regions beyond the penumbra. Front Cell Neurosci 2024; 18:1336886. [PMID: 38504666 PMCID: PMC10948541 DOI: 10.3389/fncel.2024.1336886] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2023] [Accepted: 02/08/2024] [Indexed: 03/21/2024] Open
Abstract
The changes in the necrotic core and the penumbra following induction of focal ischemia have been the focus of attention for some time. However, evidence shows, that ischemic injury is not confined to the primarily affected structures and may influence the remote areas as well. Yet many studies fail to probe into the structures beyond the penumbra, and possibly do not even find any significant results due to their short-term design, as secondary damage occurs later. This slower reaction can be perceived as a therapeutic opportunity, in contrast to the ischemic core defined as irreversibly damaged tissue, where the window for salvation is comparatively short. The pathologies in remote structures occur relatively frequently and are clearly linked to the post-stroke neurological outcome. In order to develop efficient therapies, a deeper understanding of what exactly happens in the exo-focal regions is necessary. The mechanisms of glia contribution to the ischemic damage in core/penumbra are relatively well described and include impaired ion homeostasis, excessive cell swelling, glutamate excitotoxic mechanism, release of pro-inflammatory cytokines and phagocytosis or damage propagation via astrocytic syncytia. However, little is known about glia involvement in post-ischemic processes in remote areas. In this literature review, we discuss the definitions of the terms "ischemic core", "penumbra" and "remote areas." Furthermore, we present evidence showing the array of structural and functional changes in the more remote regions from the primary site of focal ischemia, with a special focus on glia and the extracellular matrix. The collected information is compared with the processes commonly occurring in the ischemic core or in the penumbra. Moreover, the possible causes of this phenomenon and the approaches for investigation are described, and finally, we evaluate the efficacy of therapies, which have been studied for their anti-ischemic effect in remote areas in recent years.
Collapse
Affiliation(s)
- Ludmila Koukalova
- Department of Neuroscience, Second Faculty of Medicine, Charles University, Prague, Czechia
| | - Martina Chmelova
- Department of Neuroscience, Second Faculty of Medicine, Charles University, Prague, Czechia
- Department of Cellular Neurophysiology, Institute of Experimental Medicine of the Czech Academy of Sciences, Prague, Czechia
| | - Zuzana Amlerova
- Department of Neuroscience, Second Faculty of Medicine, Charles University, Prague, Czechia
| | - Lydia Vargova
- Department of Neuroscience, Second Faculty of Medicine, Charles University, Prague, Czechia
- Department of Cellular Neurophysiology, Institute of Experimental Medicine of the Czech Academy of Sciences, Prague, Czechia
| |
Collapse
|
2
|
Seki E, Komori T, Arai N. Expanded ischemic lesion due to herniation leads to axonal injury in a site remote to the primary lesion on autopsy brain with acute focal cerebral ischemia. Neuropathology 2023; 43:373-384. [PMID: 36855231 DOI: 10.1111/neup.12900] [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: 01/10/2023] [Revised: 02/05/2023] [Accepted: 02/11/2023] [Indexed: 03/02/2023]
Abstract
Cerebral ischemia may lead to axonal injury not only at the site of the primary lesion but also in a region remote to the site of insult. In this study, we investigated the effect of herniation on the development of axonal injury at a site remote to the primary lesion during the acute phase of cerebral ischemia. We obtained postmortem brains of 13 cases with acute phase of unilateral cerebral infarction in the territory of the internal carotid artery or middle cerebral artery and seven controls. We classified the brain tissues into herniation and non-herniation groups. Then we examined whether axonal and ischemic changes existed in the corpus callosum contralateral to the ischemic hemisphere and the upper pons. In the herniation group, we detected white-matter lesions by Klüver-Barrera staining, microglial loss by immunohistochemistry for ionized calcium-binding adaptor molecule 1, and axonal injury by immunohistochemistry for amyloid precursor protein. However, none of the aforementioned findings were observed in the non-herniation group. These findings suggest the existence of regional overlap in axonal and ischemic pathologies in remote regions in the presence of herniation. We concluded that herniation may play a significant role in the development of axonal and ischemic changes in the remote region. Our results suggest that axonal injury in a remote region may result from expanded ischemic lesions due to herniation.
Collapse
Affiliation(s)
- Erika Seki
- Laboratory of Neuropathology, Tokyo Metropolitan Institute of Medical Science, Setagaya-ku, Japan
| | - Takashi Komori
- Department of Laboratory Medicine and Pathology (Neuropathology), Tokyo Metropolitan Neurological Hospital, Tokyo Metropolitan Hospital Organization, Fuchu, Japan
| | - Nobutaka Arai
- Laboratory of Neuropathology, Tokyo Metropolitan Institute of Medical Science, Setagaya-ku, Japan
- Department of Laboratory Medicine and Pathology (Neuropathology), Tokyo Metropolitan Neurological Hospital, Tokyo Metropolitan Hospital Organization, Fuchu, Japan
| |
Collapse
|
3
|
Laaksonen M, Rinne J, Rahi M, Posti JP, Laitio R, Kivelev J, Saarenpää I, Laukka D, Frösen J, Ronkainen A, Bendel S, Långsjö J, Ala-Peijari M, Saunavaara J, Parkkola R, Nyman M, Martikainen IK, Dickens AM, Rinne J, Valtonen M, Saari TI, Koivisto T, Bendel P, Roine T, Saraste A, Vahlberg T, Tanttari J, Laitio T. Effect of xenon on brain injury, neurological outcome, and survival in patients after aneurysmal subarachnoid hemorrhage-study protocol for a randomized clinical trial. Trials 2023; 24:417. [PMID: 37337295 DOI: 10.1186/s13063-023-07432-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Accepted: 06/05/2023] [Indexed: 06/21/2023] Open
Abstract
BACKGROUND Aneurysmal subarachnoid hemorrhage (aSAH) is a neurological emergency, affecting a younger population than individuals experiencing an ischemic stroke; aSAH is associated with a high risk of mortality and permanent disability. The noble gas xenon has been shown to possess neuroprotective properties as demonstrated in numerous preclinical animal studies. In addition, a recent study demonstrated that xenon could attenuate a white matter injury after out-of-hospital cardiac arrest. METHODS The study is a prospective, multicenter phase II clinical drug trial. The study design is a single-blind, prospective superiority randomized two-armed parallel follow-up study. The primary objective of the study is to explore the potential neuroprotective effects of inhaled xenon, when administered within 6 h after the onset of symptoms of aSAH. The primary endpoint is the extent of the global white matter injury assessed with magnetic resonance diffusion tensor imaging of the brain. DISCUSSION Despite improvements in medical technology and advancements in medical science, aSAH mortality and disability rates have remained nearly unchanged for the past 10 years. Therefore, new neuroprotective strategies to attenuate the early and delayed brain injuries after aSAH are needed to reduce morbidity and mortality. TRIAL REGISTRATION ClinicalTrials.gov NCT04696523. Registered on 6 January 2021. EudraCT, EudraCT Number: 2019-001542-17. Registered on 8 July 2020.
Collapse
Affiliation(s)
- Mikael Laaksonen
- Department of Perioperative Services, Intensive Care Medicine and Pain Management, Turku University Hospital and University of Turku, P.O. Box 52, FIN-20521, Turku, Finland.
| | - Jaakko Rinne
- Neurocenter, Department of Neurosurgery and Turku Brain Injury Center, Turku University Hospital and University of Turku, Turku, Finland
| | - Melissa Rahi
- Neurocenter, Department of Neurosurgery and Turku Brain Injury Center, Turku University Hospital and University of Turku, Turku, Finland
| | - Jussi P Posti
- Neurocenter, Department of Neurosurgery and Turku Brain Injury Center, Turku University Hospital and University of Turku, Turku, Finland
| | - Ruut Laitio
- Department of Perioperative Services, Intensive Care Medicine and Pain Management, Turku University Hospital and University of Turku, P.O. Box 52, FIN-20521, Turku, Finland
| | - Juri Kivelev
- Neurocenter, Department of Neurosurgery and Turku Brain Injury Center, Turku University Hospital and University of Turku, Turku, Finland
| | - Ilkka Saarenpää
- Neurocenter, Department of Neurosurgery and Turku Brain Injury Center, Turku University Hospital and University of Turku, Turku, Finland
| | - Dan Laukka
- Neurocenter, Department of Neurosurgery and Turku Brain Injury Center, Turku University Hospital and University of Turku, Turku, Finland
| | - Juhana Frösen
- Department of Neurosurgery, Faculty of Medicine and Health Technology, Tampere University Hospital, University of Tampere, Tampere, Finland
| | - Antti Ronkainen
- Department of Neurosurgery, Faculty of Medicine and Health Technology, Tampere University Hospital, University of Tampere, Tampere, Finland
| | - Stepani Bendel
- Department of Intensive Care, Kuopio University Hospital, University of Eastern Finland, Kuopio, Finland
| | - Jaakko Långsjö
- Department of Anesthesiology and Intensive Care, Tampere University Hospital and University of Tampere, Tampere, Finland
| | - Marika Ala-Peijari
- Department of Anesthesiology and Intensive Care, Tampere University Hospital and University of Tampere, Tampere, Finland
| | - Jani Saunavaara
- Department of Medical Physics, Turku University Hospital and University of Turku, Turku, Finland
| | - Riitta Parkkola
- Department of Radiology, Turku University Hospital and University of Turku, Turku, Finland
| | - Mikko Nyman
- Department of Radiology, Turku University Hospital and University of Turku, Turku, Finland
| | - Ilkka K Martikainen
- Department of Radiology, Tampere University Hospital and University of Tampere, Tampere, Finland
| | - Alex M Dickens
- Analysis of the metabolomics, University of Turku, Turku BioscienceTurku, Finland
| | - Juha Rinne
- Turku PET Centre, Turku University Hospital and University of Turku, Turku, Finland
| | - Mika Valtonen
- Department of Perioperative Services, Intensive Care Medicine and Pain Management, Turku University Hospital and University of Turku, P.O. Box 52, FIN-20521, Turku, Finland
| | - Teijo I Saari
- Department of Perioperative Services, Intensive Care Medicine and Pain Management, Turku University Hospital and University of Turku, P.O. Box 52, FIN-20521, Turku, Finland
| | - Timo Koivisto
- Department of Neurosurgery, Kuopio University Hospital, University of Eastern Finland, NeurocenterKuopio, Finland
| | - Paula Bendel
- Department of Radiology, Kuopio University Hospital, Kuopio, Finland
| | - Timo Roine
- Department of Neuroscience and Biomedical Engineering, Aalto University School of Science, Espoo, Finland
| | - Antti Saraste
- Heart Centre, Turku University Hospital, Turku University Hospital and University of Turku, Turku, Finland
| | - Tero Vahlberg
- Department of Biostatistics, University of Turku, Turku, Finland
| | - Juha Tanttari
- Technical Analysis, Elomatic Consulting & Engineering, Thane, India
| | - Timo Laitio
- Department of Perioperative Services, Intensive Care Medicine and Pain Management, Turku University Hospital and University of Turku, P.O. Box 52, FIN-20521, Turku, Finland
| |
Collapse
|
4
|
D'Anna L, Searle G, Harvey K, Matthews PM, Veltkamp R. Time course of neuroinflammation after human stroke - a pilot study using co-registered PET and MRI. BMC Neurol 2023; 23:193. [PMID: 37193998 DOI: 10.1186/s12883-023-03178-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2022] [Accepted: 03/22/2023] [Indexed: 05/18/2023] Open
Abstract
BACKGROUND Microglial activation contributes to both inflammatory damage and repair in experimental ischemic stroke. However, because of the logistical challenges, there have been few clinical imaging studies directly describing inflammatory activation and its resolution after stroke. The purpose of our pilot study was to describe the spatio-temporal profile of brain inflammation after stroke using 18kD translocator protein (TSPO) positron emission tomography (PET) with magnetic resonance (MR) co-registration in the subacute and chronic stage after stroke. METHODS Three patients underwent magnetic resonance imaging (MRI) and PET scans with TSPO ligand [11C]PBR28 15 ± 3 and 90 ± 7 days after an ischaemic stroke. Regions of interest (ROI) were defined on MRI images and applied to the dynamic PET data to derive regional time-activity curves. Regional uptake was quantified as standardised uptake values (SUV) over 60 to 90 min post-injection. ROI analysis was applied to identify binding in the infarct, and in frontal, temporal, parietal, and occipital lobes and cerebellum excluding the infarcted area. RESULTS The mean age of participants was 56 ± 20.4 years and mean infarct volume was 17.9 ± 18.1 ml. [11C]PBR28 showed increased tracer signal in the infarcted area compared to non-infarcted areas of the brain in the subacute phase of stroke (Patient 1 SUV 1.81; Patient 2 SUV 1.15; Patient 3 SUV 1.64). [11C]PBR28 uptake returned to the level of non-infarcted areas at 90 days Patient 1 SUV 0.99; Patient 3 SUV 0.80). No additional upregulation was detected elsewhere at either time point. CONCLUSIONS The neuroinflammatory reaction after ischaemic stroke is limited in time and circumscribed in space suggesting that post-ischaemic inflammation is tightly controlled but regulatory mechanisms.
Collapse
Affiliation(s)
- Lucio D'Anna
- Department of Stroke and Neuroscience, Charing Cross Hospital, Imperial College Healthcare NHS Trust, London, UK
- Department of Brain Sciences, Imperial College London, London, UK
| | | | - Kirsten Harvey
- Department of Brain Sciences, Imperial College London, London, UK
| | - Paul M Matthews
- Department of Brain Sciences, Imperial College London, London, UK
- Dementia Research Institute at Imperial College London, London, UK
| | - Roland Veltkamp
- Department of Brain Sciences, Imperial College London, London, UK.
- Department of Neurology, Alfried-Krupp Krankenhaus Essen, Essen, Germany.
- Department of Neurology, University Hospital Heidelberg, Heidelberg, Germany.
| |
Collapse
|
5
|
Wang Z, Song Y, Bai S, Xiang W, Zhou X, Han L, Zhu D, Guan Y. Imaging of microglia in post-stroke inflammation. Nucl Med Biol 2023; 118-119:108336. [PMID: 37028196 DOI: 10.1016/j.nucmedbio.2023.108336] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2022] [Revised: 03/21/2023] [Accepted: 03/21/2023] [Indexed: 04/03/2023]
Abstract
Microglia constantly survey the central nervous system microenvironment and maintain brain homeostasis. Microglia activation, polarization and inflammatory response are of great importance in the pathophysiology of ischemic stroke. For exploring biochemical processes in vivo, positron emission tomography (PET) is a superior imaging tool. Translocator protein 18 kDa (TSPO), is a validated neuroinflammatory biomarker which is widely used to evaluate various central nervous system (CNS) pathologies in both preclinical and clinical studies. TSPO level can be elevated due to peripheral inflammatory cells infiltration and glial cells activation. Therefore, a clear understanding of the dynamic changes between microglia and TSPO is critical for interpreting PET studies and understanding the pathophysiology after ischemic stroke. Our review discusses alternative biological targets that have attracted considerable interest for the imaging of microglia activation in recent years, and the potential value of imaging of microglia in the assessment of stroke therapies.
Collapse
|
6
|
Effects of HF-rTMS on microglial polarization and white matter integrity in rats with poststroke cognitive impairment. Behav Brain Res 2023; 439:114242. [PMID: 36455674 DOI: 10.1016/j.bbr.2022.114242] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2022] [Revised: 11/24/2022] [Accepted: 11/27/2022] [Indexed: 11/30/2022]
Abstract
Poststroke cognitive impairment (PSCI) occurs frequently after stroke, but effective treatments are lacking. Previous studies have revealed that high-frequency repetitive transcranial magnetic stimulation (HF-rTMS) has a beneficial effect on PSCI, but the mechanism is unclear. This study aimed to evaluate the effect of 10 and 20 Hz HF-rTMS on PSCI and the possible mechanisms. An ischemic stroke rat model was established by transient middle cerebral artery occlusion (tMCAO). The modified neurological deficit score (mNSS) and Morris water maze tests were conducted to assess neurological function and cognitive function. Luxol Fast Blue (LFB) staining was performed to evaluate white matter damage. Proinflammatory and anti-inflammatory cytokines were measured using enzyme-linked immunosorbent assays (ELISA). Immunofluorescence was used to assess microglial activation and polarization. Western blotting was performed to measure JAK2-STAT3 pathway-related protein expression. We found that HF-rTMS decreased the neurological deficit score. Compared with 10 Hz HF-rTMS, 20 Hz HF-rTMS more markedly improved the cognitive function of tMCAO rats at day 28 after operation. Furthermore, 20 Hz HF-rTMS attenuates white matter lesion, decreased proinflammatory cytokine levels, and increased anti-inflammatory cytokine levels. It also decreased the number of CD68- and CD16/32-positive microglia and increased the number of CD206-positive microglia. In addition, p-JAK2, JAK2, p-STAT3 and STAT3 expression was increased. These findings suggest that HF-rTMS improves cognitive function and attenuates white matter lesion in tMCAO rats by shifting microglia toward the M2 phenotype. Mechanisms may be related to regulation JAK2-STAT3 pathways.
Collapse
|
7
|
Juengling FD, Wuest F, Kalra S, Agosta F, Schirrmacher R, Thiel A, Thaiss W, Müller HP, Kassubek J. Simultaneous PET/MRI: The future gold standard for characterizing motor neuron disease-A clinico-radiological and neuroscientific perspective. Front Neurol 2022; 13:890425. [PMID: 36061999 PMCID: PMC9428135 DOI: 10.3389/fneur.2022.890425] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2022] [Accepted: 07/20/2022] [Indexed: 01/18/2023] Open
Abstract
Neuroimaging assessment of motor neuron disease has turned into a cornerstone of its clinical workup. Amyotrophic lateral sclerosis (ALS), as a paradigmatic motor neuron disease, has been extensively studied by advanced neuroimaging methods, including molecular imaging by MRI and PET, furthering finer and more specific details of the cascade of ALS neurodegeneration and symptoms, facilitated by multicentric studies implementing novel methodologies. With an increase in multimodal neuroimaging data on ALS and an exponential improvement in neuroimaging technology, the need for harmonization of protocols and integration of their respective findings into a consistent model becomes mandatory. Integration of multimodal data into a model of a continuing cascade of functional loss also calls for the best attempt to correlate the different molecular imaging measurements as performed at the shortest inter-modality time intervals possible. As outlined in this perspective article, simultaneous PET/MRI, nowadays available at many neuroimaging research sites, offers the perspective of a one-stop shop for reproducible imaging biomarkers on neuronal damage and has the potential to become the new gold standard for characterizing motor neuron disease from the clinico-radiological and neuroscientific perspectives.
Collapse
Affiliation(s)
- Freimut D. Juengling
- Division of Oncologic Imaging, University of Alberta, Edmonton, AB, Canada
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, AB, Canada
- Faculty of Medicine, University Bern, Bern, Switzerland
| | - Frank Wuest
- Division of Oncologic Imaging, University of Alberta, Edmonton, AB, Canada
| | - Sanjay Kalra
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, AB, Canada
- Department of Neurology, University of Alberta, Edmonton, AB, Canada
| | - Federica Agosta
- Division of Neuroscience, San Raffaele Scientific Institute, University Vita Salute San Raffaele, Milan, Italy
| | - Ralf Schirrmacher
- Division of Oncologic Imaging, University of Alberta, Edmonton, AB, Canada
- Medical Isotope and Cyclotron Facility, University of Alberta, Edmonton, AB, Canada
| | - Alexander Thiel
- Lady Davis Institute for Medical Research, Department of Neurology and Neurosurgery, McGill University, Montreal, QC, Canada
| | - Wolfgang Thaiss
- Department of Nuclear Medicine, University of Ulm Medical Center, Ulm, Germany
- Department of Diagnostic and Interventional Radiology, University of Ulm Medical Center, Ulm, Germany
| | - Hans-Peter Müller
- Department of Neurology, Ulm University Medical Center, Ulm, Germany
| | - Jan Kassubek
- Department of Neurology, Ulm University Medical Center, Ulm, Germany
| |
Collapse
|
8
|
Stuckey SM, Ong LK, Collins-Praino LE, Turner RJ. Neuroinflammation as a Key Driver of Secondary Neurodegeneration Following Stroke? Int J Mol Sci 2021; 22:ijms222313101. [PMID: 34884906 PMCID: PMC8658328 DOI: 10.3390/ijms222313101] [Citation(s) in RCA: 49] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2021] [Revised: 11/25/2021] [Accepted: 12/01/2021] [Indexed: 01/13/2023] Open
Abstract
Ischaemic stroke involves the rapid onset of focal neurological dysfunction, most commonly due to an arterial blockage in a specific region of the brain. Stroke is a leading cause of death and common cause of disability, with over 17 million people worldwide suffering from a stroke each year. It is now well-documented that neuroinflammation and immune mediators play a key role in acute and long-term neuronal tissue damage and healing, not only in the infarct core but also in distal regions. Importantly, in these distal regions, termed sites of secondary neurodegeneration (SND), spikes in neuroinflammation may be seen sometime after the initial stroke onset, but prior to the presence of the neuronal tissue damage within these regions. However, it is key to acknowledge that, despite the mounting information describing neuroinflammation following ischaemic stroke, the exact mechanisms whereby inflammatory cells and their mediators drive stroke-induced neuroinflammation are still not fully understood. As a result, current anti-inflammatory treatments have failed to show efficacy in clinical trials. In this review we discuss the complexities of post-stroke neuroinflammation, specifically how it affects neuronal tissue and post-stroke outcome acutely, chronically, and in sites of SND. We then discuss current and previously assessed anti-inflammatory therapies, with a particular focus on how failed anti-inflammatories may be repurposed to target SND-associated neuroinflammation.
Collapse
Affiliation(s)
- Shannon M. Stuckey
- Discipline of Anatomy and Pathology, School of Biomedicine, Faculty of Health and Medical Sciences, The University of Adelaide, Adelaide 5005, Australia; (S.M.S.); (L.E.C.-P.)
| | - Lin Kooi Ong
- School of Pharmacy, Monash University Malaysia, Subang Jaya 47500, Malaysia;
- School of Biomedical Sciences and Pharmacy and the Priority Research Centre for Stroke and Brain Injury, The University of Newcastle, Callaghan 2308, Australia
| | - Lyndsey E. Collins-Praino
- Discipline of Anatomy and Pathology, School of Biomedicine, Faculty of Health and Medical Sciences, The University of Adelaide, Adelaide 5005, Australia; (S.M.S.); (L.E.C.-P.)
| | - Renée J. Turner
- Discipline of Anatomy and Pathology, School of Biomedicine, Faculty of Health and Medical Sciences, The University of Adelaide, Adelaide 5005, Australia; (S.M.S.); (L.E.C.-P.)
- Correspondence: ; Tel.: +61-8-8313-3114
| |
Collapse
|
9
|
A pilot [ 11C]PBR28 PET/MRI study of neuroinflammation and neurodegeneration in chronic stroke patients. Brain Behav Immun Health 2021; 17:100336. [PMID: 34589819 PMCID: PMC8474408 DOI: 10.1016/j.bbih.2021.100336] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Revised: 08/18/2021] [Accepted: 08/21/2021] [Indexed: 11/24/2022] Open
Abstract
Neuroinflammation occurs in response to acute ischemic stroke, and has been speculated to underlie secondary poststroke pathologies, such as depression, that often develop over time poststroke. However, no study has examined whether neuroinflammation is present in chronic stroke patients (e.g., ≥ 1 year poststroke). This study tested whether neuroinflammation is present in chronic stroke patients, and is associated with neurodegeneration, using [11C]PBR28 PET and diffusion MRI. Eight patients with middle cerebral artery (MCA) ischemic stroke incurred 1–3 years prior and 16 healthy controls underwent [11C]PBR28 PET to measure glial activation and diffusion MRI to measure microstructural integrity by mean diffusivity (MD) and fractional anisotropy (FA) using an integrated PET/MRI scanner. Group differences in [11C]PBR28 binding, MD and FA were analyzed voxelwise across the whole brain excluding the infarct zone defined as voxels containing the infarct in any patient. Compared to controls, patients showed elevations in [11C]PBR28 binding in several brain regions outside the infarct zone, including regions with presumed direct neuroanatomical connections to the infarct (e.g., ipsilesional internal capsule and thalamus) and those without known direct connections (e.g., contralesional thalamus and cingulate gyrus). Patients also showed widespread elevations in MD, with a subset of these regions having reduced FA. In patients, MD was more elevated in regions with co-localized elevations in [11C]PBR28 binding than in contralateral regions without elevations in [11C]PBR28 binding. This pilot study supports the presence of extensive glial activation along with widespread loss in microstructural integrity in non-infarcted tissue in a cohort of patients with chronic MCA stroke. The loss in microstructural integrity was greater in regions with co-localized glial activation. It is possible that stroke risk factors (e.g., hypertension) contributed to these tissue changes in patients. Chronic neuroinflammation speculated to underlie secondary poststroke pathologies such as depression. Measured neuroinflammation in chronic stroke patients using [11C]PBR28 PET. First study showing extensive neuroinflammation in non-infarcted tissue in chronic stroke patients.
Collapse
|
10
|
Pan Y, Jiao Q, Wei W, Zheng T, Yang X, Xin W. Emerging Role of LncRNAs in Ischemic Stroke-Novel Insights into the Regulation of Inflammation. J Inflamm Res 2021; 14:4467-4483. [PMID: 34522116 PMCID: PMC8434908 DOI: 10.2147/jir.s327291] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Accepted: 08/24/2021] [Indexed: 12/14/2022] Open
Abstract
As a crucial kind of pervasive gene, long noncoding RNAs (lncRNAs) are abundant and key players in brain function as well as numerous neurological disorders, especially ischemic stroke. The mechanisms underlying ischemic stroke include angiogenesis, autophagy, apoptosis, cell death, and neuroinflammation. Inflammation plays a vital role in the pathological process of ischemic stroke, and systemic inflammation affects the patient’s prognosis. Although a great deal of research has illustrated that various lncRNAs are closely relevant to regulate neuroinflammation and microglial activation in ischemic stroke, the specific interactional relationships and mechanisms between lncRNAs and neuroinflammation have not been described clearly. This review aimed to summarize the therapeutic effects and action mechanisms of lncRNAs on ischemia by regulating inflammation and microglial activation. In addition, we emphasize that lncRNAs have the potential to modulate inflammation by inhibiting and activating various signaling pathways, such as microRNAs, NF‐κB and ERK.
Collapse
Affiliation(s)
- Yongli Pan
- Department of Neurology, Weifang Medical University, Weifang, Shandong, People's Republic of China
| | - Qingzheng Jiao
- Second Department of Internal Medicine, Gucheng County Hospital, Gucheng, Hebei, People's Republic of China
| | - Wei Wei
- Department of Neurology, Mianyang Central Hospital, Mianyang, Sichuan, People's Republic of China
| | - Tianyang Zheng
- Department of Neurosurgery, The First Hospital of Jilin University, Changchun, Jilin, People's Republic of China
| | - Xinyu Yang
- Department of Neurosurgery, Tianjin Medical University General Hospital, Tianjin, People's Republic of China
| | - Wenqiang Xin
- Department of Neurosurgery, Tianjin Medical University General Hospital, Tianjin, People's Republic of China
| |
Collapse
|
11
|
Hubert V, Hristovska I, Karpati S, Benkeder S, Dey A, Dumot C, Amaz C, Chounlamountri N, Watrin C, Comte J, Chauveau F, Brun E, Marche P, Lerouge F, Parola S, Berthezène Y, Vorup‐Jensen T, Pascual O, Wiart M. Multimodal Imaging with NanoGd Reveals Spatiotemporal Features of Neuroinflammation after Experimental Stroke. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2021; 8:e2101433. [PMID: 34197055 PMCID: PMC8425862 DOI: 10.1002/advs.202101433] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Revised: 05/12/2021] [Indexed: 05/09/2023]
Abstract
The purpose of this study is to propose and validate a preclinical in vivo magnetic resonance imaging (MRI) tool to monitor neuroinflammation following ischemic stroke, based on injection of a novel multimodal nanoprobe, NanoGd, specifically designed for internalization by phagocytic cells. First, it is verified that NanoGd is efficiently internalized by microglia in vitro. In vivo MRI coupled with intravenous injection of NanoGd in a permanent middle cerebral artery occlusion mouse model results in hypointense signals in the ischemic lesion. In these mice, longitudinal two-photon intravital microscopy shows NanoGd internalization by activated CX3CR1-GFP/+ cells. Ex vivo analysis, including phase contrast imaging with synchrotron X-ray, histochemistry, and transmission electron microscopy corroborate NanoGd accumulation within the ischemic lesion and uptake by immune phagocytic cells. Taken together, these results confirm the potential of NanoGd-enhanced MRI as an imaging biomarker of neuroinflammation at the subacute stage of ischemic stroke. As far as it is known, this work is the first to decipher the working mechanism of MR signals induced by a nanoparticle passively targeted at phagocytic cells by performing intravital microscopy back-to-back with MRI. Furthermore, using a gadolinium-based rather than an iron-based contrast agent raises future perspectives for the development of molecular imaging with emerging computed tomography technologies.
Collapse
Affiliation(s)
- Violaine Hubert
- Univ‐LyonIRIS TeamCarMeN LaboratoryInserm U1060INRA U1397INSA LyonUniversité Claude Bernard Lyon 1Groupement Hospitalier Est59 bd. PinelBron69500France
| | - Ines Hristovska
- SYNATAC TeamInstitut NeuroMyoGèneUniversité Claude Bernard Lyon 1CNRS UMR 5310, INSERM U1217Faculté de Médecine et de Pharmacie8 avenue RockefellerLyon69008France
| | - Szilvia Karpati
- Université de LyonÉcole Normale Supérieure de LyonCNRS UMR 5182Université Claude Bernard Lyon 1Laboratoire de ChimieLyonF69342France
| | - Sarah Benkeder
- SYNATAC TeamInstitut NeuroMyoGèneUniversité Claude Bernard Lyon 1CNRS UMR 5310, INSERM U1217Faculté de Médecine et de Pharmacie8 avenue RockefellerLyon69008France
| | - Arindam Dey
- Institut pour l'Avancée des BiosciencesCentre de Recherche UGA / Inserm U 1209 / CNRS UMR 5309Site Santé ‐ Allée des AlpesLa Tronche38700France
| | - Chloé Dumot
- Univ‐LyonIRIS TeamCarMeN LaboratoryInserm U1060INRA U1397INSA LyonUniversité Claude Bernard Lyon 1Groupement Hospitalier Est59 bd. PinelBron69500France
| | - Camille Amaz
- Clinical Investigation CenterHospices Civils de LyonLouis Pradel Hospital28 avenue Doyen LépineBron69500France
| | - Naura Chounlamountri
- SYNATAC TeamInstitut NeuroMyoGèneUniversité Claude Bernard Lyon 1CNRS UMR 5310, INSERM U1217Faculté de Médecine et de Pharmacie8 avenue RockefellerLyon69008France
| | - Chantal Watrin
- SYNATAC TeamInstitut NeuroMyoGèneUniversité Claude Bernard Lyon 1CNRS UMR 5310, INSERM U1217Faculté de Médecine et de Pharmacie8 avenue RockefellerLyon69008France
| | - Jean‐Christophe Comte
- FORGETTING TeamLyon Neuroscience Research Center (CRNL)CNRS UMR5292INSERM U1028Université Claude Bernard Lyon 1Centre Hospitalier Le Vinatier ‐ Bâtiment 462 ‐ Neurocampus Michel Jouvet95 boulevard PinelBron69675France
| | - Fabien Chauveau
- Université de LyonLyon Neuroscience Research Center (CRNL)CNRS UMR5292INSERM U1028Université Claude Bernard Lyon 1Groupement Hospitalier Est ‐ CERMEP59 bd PinelBron Cedex69677France
| | - Emmanuel Brun
- Synchrotron Radiation for Biomedical Research (STROBE)UA7 INSERMUniversité Grenoble AlpesMedical Beamline at the European Synchrotron Radiation Facility71 Avenue des MartyrsGrenoble Cedex 938043France
| | - Patrice Marche
- Institut pour l'Avancée des BiosciencesCentre de Recherche UGA / Inserm U 1209 / CNRS UMR 5309Site Santé ‐ Allée des AlpesLa Tronche38700France
| | - Fréderic Lerouge
- Université de LyonÉcole Normale Supérieure de LyonCNRS UMR 5182Université Claude Bernard Lyon 1Laboratoire de ChimieLyonF69342France
| | - Stéphane Parola
- Université de LyonÉcole Normale Supérieure de LyonCNRS UMR 5182Université Claude Bernard Lyon 1Laboratoire de ChimieLyonF69342France
| | - Yves Berthezène
- Univ‐LyonCreatis LaboratoryCNRS UMR5220Inserm U1044INSA LyonVilleurbanne Cedex69621France
| | - Thomas Vorup‐Jensen
- Department of BiomedicineBiophysical Immunology LaboratoryAarhus UniversityAarhus CDK‐8000Denmark
| | - Olivier Pascual
- SYNATAC TeamInstitut NeuroMyoGèneUniversité Claude Bernard Lyon 1CNRS UMR 5310, INSERM U1217Faculté de Médecine et de Pharmacie8 avenue RockefellerLyon69008France
| | - Marlène Wiart
- Univ‐LyonIRIS TeamCarMeN LaboratoryInserm U1060INRA U1397INSA LyonUniversité Claude Bernard Lyon 1Groupement Hospitalier Est59 bd. PinelBron69500France
| |
Collapse
|
12
|
Filling the gaps on stroke research: Focus on inflammation and immunity. Brain Behav Immun 2021; 91:649-667. [PMID: 33017613 PMCID: PMC7531595 DOI: 10.1016/j.bbi.2020.09.025] [Citation(s) in RCA: 60] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Revised: 09/10/2020] [Accepted: 09/23/2020] [Indexed: 02/08/2023] Open
Abstract
For the last two decades, researchers have placed hopes in a new era in which a combination of reperfusion and neuroprotection would revolutionize the treatment of stroke. Nevertheless, despite the thousands of papers available in the literature showing positive results in preclinical stroke models, randomized clinical trials have failed to show efficacy. It seems clear now that the existing data obtained in preclinical research have depicted an incomplete picture of stroke pathophysiology. In order to ameliorate bench-to-bed translation, in this review we first describe the main actors on stroke inflammatory and immune responses based on the available preclinical data, highlighting the fact that the link between leukocyte infiltration, lesion volume and neurological outcome remains unclear. We then describe what is known on neuroinflammation and immune responses in stroke patients, and summarize the results of the clinical trials on immunomodulatory drugs. In order to understand the gap between clinical trials and preclinical results on stroke, we discuss in detail the experimental results that served as the basis for the summarized clinical trials on immunomodulatory drugs, focusing on (i) experimental stroke models, (ii) the timing and selection of outcome measuring, (iii) alternative entry routes for leukocytes into the ischemic region, and (iv) factors affecting stroke outcome such as gender differences, ageing, comorbidities like hypertension and diabetes, obesity, tobacco, alcohol consumption and previous infections like Covid-19. We can do better for stroke treatment, especially when targeting inflammation following stroke. We need to re-think the design of stroke experimental setups, notably by (i) using clinically relevant models of stroke, (ii) including both radiological and neurological outcomes, (iii) performing long-term follow-up studies, (iv) conducting large-scale preclinical stroke trials, and (v) including stroke comorbidities in preclinical research.
Collapse
|
13
|
Wright P, Veronese M, Mazibuko N, Turkheimer FE, Rabiner EA, Ballard CG, Williams SCR, Hari Narayanan AK, Osrah B, Williams R, Marques TR, Howes OD, Roncaroli F, O'Sullivan MJ. Patterns of Mitochondrial TSPO Binding in Cerebral Small Vessel Disease: An in vivo PET Study With Neuropathological Comparison. Front Neurol 2020; 11:541377. [PMID: 33178101 PMCID: PMC7596201 DOI: 10.3389/fneur.2020.541377] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Accepted: 08/20/2020] [Indexed: 12/11/2022] Open
Abstract
Small vessel disease (SVD) is associated with cognitive impairment in older age and be implicated in vascular dementia. Post-mortem studies show proliferation of activated microglia in the affected white matter. However, the role of inflammation in SVD pathogenesis is incompletely understood and better biomarkers are needed. We hypothesized that expression of the 18 kDa translocator protein (TSPO), a marker of microglial activation, would be higher in SVD. Positron emission tomography (PET) was performed with the second-generation TSPO ligand [11C]PBR28 in 11 participants with SVD. TSPO binding was evaluated by a two-tissue compartment model, with and without a vascular binding component, in white matter hyperintensities (WMH) and normal-appearing white matter (NAWM). In post-mortem tissue, in a separate cohort of individuals with SVD, immunohistochemistry was performed for TSPO and a pan-microglial marker Iba1. Kinetic modeling showed reduced tracer volume and blood volume fraction in WMH compared with NAWM, but a significant increase in vascular binding. Vascular [11C]PBR28 binding was also increased compared with normal-appearing white matter of healthy participants free of SVD. Immunohistochemistry showed a diffuse increase in microglial staining (with Iba1) in sampled tissue in SVD compared with control samples, but with only a subset of microglia staining positively for TSPO. Intense TSPO staining was observed in the vicinity of damaged small blood vessels, which included perivascular macrophages. The results suggest an altered phenotype of activated microglia, with reduced TSPO expression, in the areas of greatest white matter ischemia in SVD, with implications for the interpretation of TSPO PET studies in older individuals or those with vascular risk factors.
Collapse
Affiliation(s)
- Paul Wright
- Department of Neuroimaging, Institute of Psychiatry Psychology & Neuroscience, King's College London, London, United Kingdom
| | - Mattia Veronese
- Department of Neuroimaging, Institute of Psychiatry Psychology & Neuroscience, King's College London, London, United Kingdom
| | - Ndabezinhle Mazibuko
- Department of Neuroimaging, Institute of Psychiatry Psychology & Neuroscience, King's College London, London, United Kingdom
| | - Federico E. Turkheimer
- Department of Neuroimaging, Institute of Psychiatry Psychology & Neuroscience, King's College London, London, United Kingdom
| | - Eugenii A. Rabiner
- Department of Neuroimaging, Institute of Psychiatry Psychology & Neuroscience, King's College London, London, United Kingdom
- Invicro, London, United Kingdom
| | - Clive G. Ballard
- College of Medicine and Health, University of Exeter, Exeter, United Kingdom
| | - Steven C. R. Williams
- Department of Neuroimaging, Institute of Psychiatry Psychology & Neuroscience, King's College London, London, United Kingdom
| | - Avinash Kumar Hari Narayanan
- Division of Neuroscience and Experimental Psychology, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
- Manchester Centre for Clinical Neuroscience, Salford Royal Foundation Trust, Salford, United Kingdom
| | - Bahiya Osrah
- Division of Neuroscience and Experimental Psychology, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
- Manchester Centre for Clinical Neuroscience, Salford Royal Foundation Trust, Salford, United Kingdom
| | - Ricky Williams
- Division of Neuroscience and Experimental Psychology, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
- Manchester Centre for Clinical Neuroscience, Salford Royal Foundation Trust, Salford, United Kingdom
| | - Tiago R. Marques
- Department of Psychosis Studies, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, United Kingdom
| | - Oliver D. Howes
- Department of Psychosis Studies, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, United Kingdom
| | - Federico Roncaroli
- Division of Neuroscience and Experimental Psychology, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
- Manchester Centre for Clinical Neuroscience, Salford Royal Foundation Trust, Salford, United Kingdom
| | - Michael J. O'Sullivan
- Department of Neuroimaging, Institute of Psychiatry Psychology & Neuroscience, King's College London, London, United Kingdom
- University of Queensland Centre for Clinical Research, Brisbane, QLD, Australia
- Department of Neurology, The Royal Brisbane and Women's Hospital, Herston, QLD, Australia
| |
Collapse
|
14
|
Shi K, Tian DC, Li ZG, Ducruet AF, Lawton MT, Shi FD. Global brain inflammation in stroke. Lancet Neurol 2019; 18:1058-1066. [PMID: 31296369 DOI: 10.1016/s1474-4422(19)30078-x] [Citation(s) in RCA: 441] [Impact Index Per Article: 88.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2018] [Revised: 02/11/2019] [Accepted: 02/11/2019] [Indexed: 01/21/2023]
Abstract
Stroke, including acute ischaemic stroke and intracerebral haemorrhage, results in neuronal cell death and the release of factors such as damage-associated molecular patterns (DAMPs) that elicit localised inflammation in the injured brain region. Such focal brain inflammation aggravates secondary brain injury by exacerbating blood-brain barrier damage, microvascular failure, brain oedema, oxidative stress, and by directly inducing neuronal cell death. In addition to inflammation localised to the injured brain region, a growing body of evidence suggests that inflammatory responses after a stroke occur and persist throughout the entire brain. Global brain inflammation might continuously shape the evolving pathology after a stroke and affect the patients' long-term neurological outcome. Future efforts towards understanding the mechanisms governing the emergence of so-called global brain inflammation would facilitate modulation of this inflammation as a potential therapeutic strategy for stroke.
Collapse
Affiliation(s)
- Kaibin Shi
- Tianjin Medical University General Hospital, Tianjin, China; Department of Neurology, and Department of Neurosurgery, Barrow Neurological Institute, St Joseph's Hospital and Medical Center, Phoenix, AZ, USA
| | - De-Cai Tian
- China National Clinical Research Center for Neurological Diseases, Beijing Tiantan Hospital, Capital Medical University, Beijing, China; Tianjin Medical University General Hospital, Tianjin, China
| | - Zhi-Guo Li
- Tianjin Medical University General Hospital, Tianjin, China
| | - Andrew F Ducruet
- Department of Neurology, and Department of Neurosurgery, Barrow Neurological Institute, St Joseph's Hospital and Medical Center, Phoenix, AZ, USA
| | - Michael T Lawton
- Department of Neurology, and Department of Neurosurgery, Barrow Neurological Institute, St Joseph's Hospital and Medical Center, Phoenix, AZ, USA
| | - Fu-Dong Shi
- China National Clinical Research Center for Neurological Diseases, Beijing Tiantan Hospital, Capital Medical University, Beijing, China; Tianjin Medical University General Hospital, Tianjin, China.
| |
Collapse
|
15
|
Thammisetty SS, Pedragosa J, Weng YC, Calon F, Planas A, Kriz J. Age-related deregulation of TDP-43 after stroke enhances NF-κB-mediated inflammation and neuronal damage. J Neuroinflammation 2018; 15:312. [PMID: 30413172 PMCID: PMC6230239 DOI: 10.1186/s12974-018-1350-y] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Accepted: 10/29/2018] [Indexed: 12/13/2022] Open
Abstract
Background TDP-43 has been identified as a disease-associated protein in several chronic neurodegenerative disorders and increasing evidence suggests its potentially pathogenic role following brain injuries. Normally expressed in nucleus, under pathological conditions TDP-43 forms cytoplasmic ubiquitinated inclusions in which it is abnormally phosphorylated and cleaved to generate a 35 and a 25 kDa C-terminal fragments. In the present study, we investigated age-related expression patterns of TDP-43 in neurons and glia and its role as modulator of inflammation following ischemic injury. Methods Wild-type and TDP-43 transgenic mice of different age groups were subjected to transient middle cerebral artery occlusion. The role of TDP-43 in modulation of inflammation was assessed using immunofluorescence, Western blot analysis, and in vivo bioluminescence imaging. Finally, post-mortem stroke human brain sections were analyzed for TDP-43 protein by immunohistochemistry. Results We report here an age-related increase and formation of ubiquitinated TDP-43 cytoplasmic inclusions after stroke. The observed deregulation in TDP-43 expression patterns was associated with an increase in microglial activation and innate immune signaling as revealed by in vivo bioluminescence imaging and immunofluorescence analysis. The presence of ubiquitinated TDP-43 aggregates and its cleaved TDP-35 and TDP-25 fragments was markedly increased in older, 12-month-old mice leading to larger infarctions and a significant increase in in neuronal death. Importantly, unlike the hallmark neuropathological features associated with chronic neurodegenerative disorders, the TDP-43-positive cytoplasmic inclusions detected after stroke were not phosphorylated. Next, we showed that an increase and/or overexpression of the cytoplasmic TDP-43 drives the pathogenic NF-κB response and further increases levels of pro-inflammatory markers and ischemic injury after stroke in age-dependent manner. Finally, analyses of the post-mortem stroke brain tissues revealed the presence of the cytoplasmic TDP-43 immunoreactive structures after human stroke. Conclusion Together, our findings suggest that the level of cytoplasmic TDP-43 increases with aging and may act as an age-related mediator of inflammation and neuronal injury after stroke. Thus, targeting cytoplasmic TDP-43 may have a therapeutic potential after stroke. Electronic supplementary material The online version of this article (10.1186/s12974-018-1350-y) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Sai Sampath Thammisetty
- CERVO Brain Research Centre, Université Laval, 2601 Chemin de la Canardière, Québec, QC, G1J 2G3, Canada.,Faculty of Pharmacy, Université Laval, Québec, QC, G1J2G3, Canada
| | | | - Yuan Cheng Weng
- CERVO Brain Research Centre, Université Laval, 2601 Chemin de la Canardière, Québec, QC, G1J 2G3, Canada
| | - Frédéric Calon
- Research Centre of the CHUQ, Université Laval, Québec, QC, G1J2G3, Canada.,Faculty of Pharmacy, Université Laval, Québec, QC, G1J2G3, Canada
| | | | - Jasna Kriz
- CERVO Brain Research Centre, Université Laval, 2601 Chemin de la Canardière, Québec, QC, G1J 2G3, Canada. .,Department of Psychiatry and Neuroscience, Faculty of Medicine, Université Laval, 2601 Chemin de la Canardière, Québec, QC, G1J2G3, Canada.
| |
Collapse
|
16
|
Selvaraj S, Bloomfield PS, Cao B, Veronese M, Turkheimer F, Howes OD. Brain TSPO imaging and gray matter volume in schizophrenia patients and in people at ultra high risk of psychosis: An [ 11C]PBR28 study. Schizophr Res 2018; 195:206-214. [PMID: 28893493 PMCID: PMC6027955 DOI: 10.1016/j.schres.2017.08.063] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/01/2017] [Revised: 08/31/2017] [Accepted: 08/31/2017] [Indexed: 12/12/2022]
Abstract
Patients with schizophrenia show whole brain and cortical gray matter (GM) volume reductions which are progressive early in their illness. Microglia, the resident immune cells in the CNS, phagocytose neurons and synapses. Some post mortem and in vivo studies in schizophrenia show evidence for elevated microglial activation compared to matched controls. However, it is currently unclear how these results relate to changes in cortical structure. METHODS Fourteen patients with schizophrenia and 14 ultra high risk for psychosis (UHR) subjects alongside two groups of age and genotype matched healthy controls received [11C]PBR28 PET scans to index TSPO expression, a marker of microglial activation and a 3T MRI scan. We investigated the relationship between the volume changes of cortical regions and microglial activation in cortical GM (as indexed by [11C]PBR28 distribution volume ratio (DVR). RESULTS The total cortical GM volume was significantly lower in SCZ than the controls [mean (SD)/cm3: SCZ=448.83 (39.2) and controls=499.6 (59.2) (p=0.02) but not in UHR (mean (SD)=503.06 (57.9) and controls=524.46 (45.3) p=0.3). Regression model fitted the total cortical GM DVR values with the cortical regional volumes in SCZ (r=0.81; p<0.001) and in UHR (r=0.63; p=0.02). We found a significant negative correlation between the TSPO signal and total cortical GM volume in SCZ with the highest absolute correlation coefficient in the right superior-parietal cortex (r=-0.72; p=0.006). CONCLUSIONS These findings suggest that microglial activity is related to the altered cortical volume seen in schizophrenia. Longitudinal investigations are required to determine whether microglial activation leads to cortical gray matter loss.
Collapse
Affiliation(s)
- Sudhakar Selvaraj
- Department of Psychiatry and Behavioural Sciences, The University of Texas Health Science Center at Houston, Houston, TX 77054, USA; Psychiatric Imaging Group, MRC Clinical Sciences Centre, Institute of Clinical Sciences, Imperial College London, Hammersmith Hospital, London, W12 0NN, UK.
| | - Peter S Bloomfield
- Psychiatric Imaging Group, MRC Clinical Sciences Centre, Institute of Clinical Sciences, Imperial College London, Hammersmith Hospital, London, W12 0NN, UK
| | - Bo Cao
- Department of Psychiatry and Behavioural Sciences, The University of Texas Health Science Center at Houston, Houston, TX 77054, USA
| | - Mattia Veronese
- Centre for Neuroimaging Sciences, IoPPN, King's College London, Box PO89, De Crespigny Park, London SE5 8AF, UK
| | - Federico Turkheimer
- Centre for Neuroimaging Sciences, IoPPN, King's College London, Box PO89, De Crespigny Park, London SE5 8AF, UK
| | - Oliver D Howes
- Psychiatric Imaging Group, MRC Clinical Sciences Centre, Institute of Clinical Sciences, Imperial College London, Hammersmith Hospital, London, W12 0NN, UK; Department of Psychosis Studies, Institute of Psychiatry, Psychology & Neuroscience, King's College London, De Crespigny Park, London SE5 8AF, UK
| |
Collapse
|
17
|
Zinnhardt B, Wiesmann M, Honold L, Barca C, Schäfers M, Kiliaan AJ, Jacobs AH. In vivo imaging biomarkers of neuroinflammation in the development and assessment of stroke therapies - towards clinical translation. Theranostics 2018; 8:2603-2620. [PMID: 29774062 PMCID: PMC5956996 DOI: 10.7150/thno.24128] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2017] [Accepted: 01/31/2018] [Indexed: 01/01/2023] Open
Abstract
Modulation of the inflammatory microenvironment after stroke opens a new avenue for the development of novel neurorestorative therapies in stroke. Understanding the spatio-temporal profile of (neuro-)inflammatory imaging biomarkers in detail thereby represents a crucial factor in the development and application of immunomodulatory therapies. The early integration of quantitative molecular imaging biomarkers in stroke drug development may provide key information about (i) early diagnosis and follow-up, (ii) spatio-temporal drug-target engagement (pharmacodynamic biomarker), (iii) differentiation of responders and non-responders in the patient cohort (inclusion/exclusion criteria; predictive biomarkers), and (iv) the mechanism of action. The use of targeted imaging biomarkers for may thus allow clinicians to decipher the profile of patient-specific inflammatory activity and the development of patient-tailored strategies for immunomodulatory and neuro-restorative therapies in stroke. Here, we highlight the recent developments in preclinical and clinical molecular imaging biomarkers of neuroinflammation (endothelial markers, microglia, MMPs, cell labeling, future developments) in stroke and outline how imaging biomarkers can be used in overcoming current translational roadblocks and attrition in order to advance new immunomodulatory compounds within the clinical pipeline.
Collapse
Affiliation(s)
- Bastian Zinnhardt
- European Institute for Molecular Imaging (EIMI), Westfälische Wilhelms University Münster, Münster, Germany
- EU 7 th FP Programme “Imaging Inflammation in Neurodegenerative Diseases (INMiND)”
- Cells in Motion (CiM) Cluster of Excellence, University of Münster, Münster, Germany
- PET Imaging in Drug Design and Development (PET3D)
- Department of Nuclear Medicine, Universitätsklinikum Münster, Münster, Germany
| | - Maximilian Wiesmann
- Department of Anatomy, Radboud university medical center, Donders Institute for Brain, Cognition & Behaviour, Nijmegen, The Netherlands
| | - Lisa Honold
- European Institute for Molecular Imaging (EIMI), Westfälische Wilhelms University Münster, Münster, Germany
| | - Cristina Barca
- European Institute for Molecular Imaging (EIMI), Westfälische Wilhelms University Münster, Münster, Germany
- PET Imaging in Drug Design and Development (PET3D)
| | - Michael Schäfers
- European Institute for Molecular Imaging (EIMI), Westfälische Wilhelms University Münster, Münster, Germany
- Cells in Motion (CiM) Cluster of Excellence, University of Münster, Münster, Germany
- Department of Nuclear Medicine, Universitätsklinikum Münster, Münster, Germany
| | - Amanda J Kiliaan
- Department of Anatomy, Radboud university medical center, Donders Institute for Brain, Cognition & Behaviour, Nijmegen, The Netherlands
| | - Andreas H Jacobs
- European Institute for Molecular Imaging (EIMI), Westfälische Wilhelms University Münster, Münster, Germany
- EU 7 th FP Programme “Imaging Inflammation in Neurodegenerative Diseases (INMiND)”
- Cells in Motion (CiM) Cluster of Excellence, University of Münster, Münster, Germany
- PET Imaging in Drug Design and Development (PET3D)
- Department of Geriatrics, Johanniter Hospital, Evangelische Kliniken, Bonn, Germany
| |
Collapse
|
18
|
Chiang GC, Hu J, Morris E, Wang Y, Gauthier SA. Quantitative Susceptibility Mapping of the Thalamus: Relationships with Thalamic Volume, Total Gray Matter Volume, and T2 Lesion Burden. AJNR Am J Neuroradiol 2018; 39:467-472. [PMID: 29371258 DOI: 10.3174/ajnr.a5537] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2017] [Accepted: 11/15/2017] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE Both thalamic iron deposition and atrophy have been reported in patients with multiple sclerosis compared with healthy controls, but how they are related is unclear. The purpose of this study was to understand the pathophysiologic basis for this iron deposition. MATERIALS AND METHODS Ninety-five patients with relapsing-remitting multiple sclerosis underwent 3T MR imaging with a standardized protocol that included quantitative susceptibility mapping to measure iron concentration and a 3D T1 echo-spoiled gradient-echo sequence to obtain thalamic volumes. Volumes of interest were manually delineated on the quantitative susceptibility map to encompass both thalami. Multivariate regression analyses were performed to identify the association between thalamic susceptibility and volume. Associations between thalamic susceptibility and total gray matter volume, cortical thickness, and T2 lesion volume were also assessed. RESULTS The relative susceptibility of the thalamus was associated with T2 lesion volume (P = .015) and was higher in the presence of enhancing lesions (P = .013). The relative susceptibility of the thalami was not associated with thalamic volumes, total gray matter volumes, or cortical thickness (P > .05). CONCLUSIONS Iron levels in the thalami are associated with T2 lesion burden and the presence of enhancing lesions, but not with thalamic or gray matter volumes, suggesting that iron accumulation is associated with white matter inflammation rather than gray matter neurodegeneration.
Collapse
Affiliation(s)
- G C Chiang
- From the Departments of Radiology (G.C.C., J.H., Y.W.)
| | - J Hu
- From the Departments of Radiology (G.C.C., J.H., Y.W.)
| | - E Morris
- Neurology (E.M., S.A.G.), Weill Cornell Medical College, NewYork-Presbyterian Hospital, New York, New York
| | - Y Wang
- From the Departments of Radiology (G.C.C., J.H., Y.W.)
| | - S A Gauthier
- Neurology (E.M., S.A.G.), Weill Cornell Medical College, NewYork-Presbyterian Hospital, New York, New York
| |
Collapse
|
19
|
Evans NR, Tarkin JM, Buscombe JR, Markus HS, Rudd JHF, Warburton EA. PET imaging of the neurovascular interface in cerebrovascular disease. Nat Rev Neurol 2017; 13:676-688. [PMID: 28984315 DOI: 10.1038/nrneurol.2017.129] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Cerebrovascular disease encompasses a range of pathologies that affect different components of the cerebral vasculature and brain parenchyma. Large artery atherosclerosis, acute cerebral ischaemia, and intracerebral small vessel disease all demonstrate altered metabolic processes that are key to their pathogenesis. Although structural imaging techniques such as MRI are the mainstay of clinical care and research in cerebrovascular disease, they have limited ability to detect these pathophysiological processes in vivo. By contrast, PET can detect and quantify metabolic processes that are relevant to each facet of cerebrovascular disease. Information obtained from PET studies has helped to shape the understanding of key concepts in cerebrovascular medicine, including vulnerable atherosclerotic plaque, salvageable ischaemic penumbra, neuroinflammation and selective neuronal loss after ischaemic insult. PET has also helped to elucidate the relationships between chronic hypoxia, neuroinflammation, and amyloid-β deposition in cerebral small vessel disease. This Review describes how PET-based imaging of metabolic processes at the neurovascular interface has contributed to our understanding of cerebrovascular disease.
Collapse
Affiliation(s)
- Nicholas R Evans
- Department of Clinical Neurosciences, University of Cambridge, Box 83, Addenbrooke's Hospital, Hills Road, Cambridge CB2 0QQ, UK
| | - Jason M Tarkin
- Division of Cardiovascular Medicine, Department of Medicine, University of Cambridge, Box 157, Addenbrooke's Hospital, Hills Road, Cambridge CB2 0QQ, UK
| | - John R Buscombe
- Department of Nuclear Medicine, Box 219, Cambridge University Hospitals NHS Foundation Trust, Hills Road, Cambridge CB2 0QQ, UK
| | - Hugh S Markus
- Department of Clinical Neurosciences, University of Cambridge, Box 83, Addenbrooke's Hospital, Hills Road, Cambridge CB2 0QQ, UK
| | - James H F Rudd
- Division of Cardiovascular Medicine, Department of Medicine, University of Cambridge, Box 157, Addenbrooke's Hospital, Hills Road, Cambridge CB2 0QQ, UK
| | - Elizabeth A Warburton
- Department of Clinical Neurosciences, University of Cambridge, Box 83, Addenbrooke's Hospital, Hills Road, Cambridge CB2 0QQ, UK
| |
Collapse
|
20
|
Jang SH, Lee HD. Gait deterioration due to neural degeneration of the corticoreticular pathway: a case report. Neural Regen Res 2016; 11:687-8. [PMID: 27212936 PMCID: PMC4870932 DOI: 10.4103/1673-5374.180759] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Affiliation(s)
- Sung Ho Jang
- Department of Physical Medicine and Rehabilitation, College of Medicine, Yeungnam University, Namku, Daegu, Republic of Korea
| | - Han Do Lee
- Department of Physical Medicine and Rehabilitation, College of Medicine, Yeungnam University, Namku, Daegu, Republic of Korea
| |
Collapse
|
21
|
Weishaupt N, Zhang A, Deziel RA, Tasker RA, Whitehead SN. Prefrontal Ischemia in the Rat Leads to Secondary Damage and Inflammation in Remote Gray and White Matter Regions. Front Neurosci 2016; 10:81. [PMID: 26973455 PMCID: PMC4773446 DOI: 10.3389/fnins.2016.00081] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2016] [Accepted: 02/18/2016] [Indexed: 12/31/2022] Open
Abstract
Secondary damage processes, such as inflammation and oxidative stress, can exacerbate an ischemic lesion and spread to adjacent brain regions. Yet, few studies investigate how regions remote from the infarct could also suffer from degeneration and inflammation in the aftermath of a stroke. To find out to what extent far-remote brain regions are affected after stroke, we used a bilateral endothelin-1-induced prefrontal infarct rat model. Brain regions posterior to the prefrontal cortical infarct were analyzed for ongoing neurodegeneration using FluoroJadeB (FJB) and for neuroinflammation using Iba1 and OX-6 immunohistochemistry 28 days post-stroke. The FJB-positive dorsomedial nucleus of the thalamus (DMN) and retrosplenial area (RSA) of the cortex displayed substantial neuroinflammation. Significant neuronal loss was only observed within the cortex. Significant microglia recruitment and activation in the FJB-positive internal capsule indicates remote white matter pathology. These findings demonstrate that even regions far remote from an infarct are affected predictably based on anatomical connectivity, and that white matter inflammation is an integral part of remote pathology. The delayed nature of this pathology makes it a valid target for preventative treatment, potentially with an extended time window of opportunity for therapeutic intervention using anti-inflammatory agents.
Collapse
Affiliation(s)
- Nina Weishaupt
- Department of Anatomy and Cell Biology, Schulich School of Medicine and Dentistry, University of Western Ontario London, ON, Canada
| | - Angela Zhang
- Department of Anatomy and Cell Biology, Schulich School of Medicine and Dentistry, University of Western Ontario London, ON, Canada
| | - Robert A Deziel
- Department of Biomedical Sciences, University of Prince Edward Island Charlottetown, PEI, Canada
| | - R Andrew Tasker
- Department of Biomedical Sciences, University of Prince Edward Island Charlottetown, PEI, Canada
| | - Shawn N Whitehead
- Department of Anatomy and Cell Biology, Schulich School of Medicine and Dentistry, University of Western Ontario London, ON, Canada
| |
Collapse
|
22
|
Janssen B, Vugts DJ, Funke U, Molenaar GT, Kruijer PS, van Berckel BNM, Lammertsma AA, Windhorst AD. Imaging of neuroinflammation in Alzheimer's disease, multiple sclerosis and stroke: Recent developments in positron emission tomography. Biochim Biophys Acta Mol Basis Dis 2015; 1862:425-41. [PMID: 26643549 DOI: 10.1016/j.bbadis.2015.11.011] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2015] [Revised: 10/09/2015] [Accepted: 11/19/2015] [Indexed: 12/13/2022]
Abstract
Neuroinflammation is thought to play a pivotal role in many diseases affecting the brain, including Alzheimer's disease, multiple sclerosis and stroke. Neuroinflammation is characterised predominantly by microglial activation, which can be visualised using positron emission tomography (PET). Traditionally, translocator protein 18kDa (TSPO) is the target for imaging of neuroinflammation using PET. In this review, recent preclinical and clinical research using PET in Alzheimer's disease, multiple sclerosis and stroke is summarised. In addition, new molecular targets for imaging of neuroinflammation, such as monoamine oxidases, adenosine receptors and cannabinoid receptor type 2, are discussed. This article is part of a Special Issue entitled: Neuro Inflammation edited by Helga E. de Vries and Markus Schwaninger.
Collapse
Affiliation(s)
- Bieneke Janssen
- Department of Radiology & Nuclear Medicine, VU University Medical Center, Amsterdam, The Netherlands.
| | - Danielle J Vugts
- Department of Radiology & Nuclear Medicine, VU University Medical Center, Amsterdam, The Netherlands
| | - Uta Funke
- Department of Radiology & Nuclear Medicine, VU University Medical Center, Amsterdam, The Netherlands; BV Cyclotron VU, Amsterdam, The Netherlands
| | - Ger T Molenaar
- Department of Radiology & Nuclear Medicine, VU University Medical Center, Amsterdam, The Netherlands; BV Cyclotron VU, Amsterdam, The Netherlands
| | | | - Bart N M van Berckel
- Department of Radiology & Nuclear Medicine, VU University Medical Center, Amsterdam, The Netherlands
| | - Adriaan A Lammertsma
- Department of Radiology & Nuclear Medicine, VU University Medical Center, Amsterdam, The Netherlands
| | - Albert D Windhorst
- Department of Radiology & Nuclear Medicine, VU University Medical Center, Amsterdam, The Netherlands.
| |
Collapse
|
23
|
|
24
|
Characterization of Behaviour and Remote Degeneration Following Thalamic Stroke in the Rat. Int J Mol Sci 2015; 16:13921-36. [PMID: 26090717 PMCID: PMC4490531 DOI: 10.3390/ijms160613921] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2015] [Revised: 05/18/2015] [Accepted: 06/11/2015] [Indexed: 11/17/2022] Open
Abstract
Subcortical ischemic strokes are among the leading causes of cognitive impairment. Selective atrophy of remote brain regions connected to the infarct is thought to contribute to deterioration of cognitive functions. The mechanisms underlying this secondary degenerative process are incompletely understood, but are thought to include inflammation. We induce ischemia by unilateral injection of endothelin-I into the rat dorsomedial thalamic nucleus, which has defined reciprocal connections to the frontal cortex. We use a comprehensive test battery to probe for changes in behaviour, including executive functions. After a four-week recovery period, brain sections are stained with markers for degeneration, microglia, astrocytes and myelin. Degenerative processes are localized within the stroke core and along the full thalamocortical projection, which does not translate into measurable behavioural deficits. Significant microglia recruitment, astrogliosis or myelin loss along the axonal projection or within the frontal cortex cannot be detected. These findings indicate that critical effects of stroke-induced axonal degeneration may only be measurable beyond a threshold of stroke severity and/or follow a different time course. Further investigations are needed to clarify the impact of inflammation accompanying axonal degeneration on delayed remote atrophy after stroke.
Collapse
|
25
|
Lourbopoulos A, Ertürk A, Hellal F. Microglia in action: how aging and injury can change the brain's guardians. Front Cell Neurosci 2015; 9:54. [PMID: 25755635 PMCID: PMC4337366 DOI: 10.3389/fncel.2015.00054] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2014] [Accepted: 02/03/2015] [Indexed: 01/03/2023] Open
Abstract
Neuroinflammation, the inflammatory response in the central nervous system (CNS), is a major determinant of neuronal function and survival during aging and disease progression. Microglia, as the resident tissue-macrophages of the brain, provide constant support to surrounding neurons in healthy brain. Upon any stress signal (such as trauma, ischemia, inflammation) they are one of the first cells to react. Local and/or peripheral signals determine microglia stress response, which can vary within a continuum of states from beneficial to detrimental for neuronal survival, and can be shaped by aging and previous insults. In this review, we discuss the roles of microglia upon an ischemic or traumatic injury, and give our perspective how aging may contribute to microglia behavior in the injured brain. We speculate that a deeper understanding of specific microglia identities will pave the way to develop more potent therapeutics to treat the diseases of aging brain.
Collapse
Affiliation(s)
- Athanasios Lourbopoulos
- Laboratory of Experimental Stroke Research, Institute for Stroke and Dementia Research (ISD), University of Munich Medical School Munich, Germany
| | - Ali Ertürk
- Laboratory of Acute Brain Injury, Institute for Stroke and Dementia Research (ISD), University of Munich Medical School Munich, Germany
| | - Farida Hellal
- Laboratory of Experimental Stroke Research, Institute for Stroke and Dementia Research (ISD), University of Munich Medical School Munich, Germany
| |
Collapse
|
26
|
In vivo analysis of neuroinflammation in the late chronic phase after experimental stroke. Neuroscience 2015; 292:71-80. [PMID: 25701708 DOI: 10.1016/j.neuroscience.2015.02.024] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2014] [Revised: 02/09/2015] [Accepted: 02/11/2015] [Indexed: 01/28/2023]
Abstract
BACKGROUND AND PURPOSE In vivo imaging of inflammatory processes is a valuable tool in stroke research. We here investigated the combination of two imaging modalities in the chronic phase after cerebral ischemia: magnetic resonance imaging (MRI) using intravenously applied ultra small supraparamagnetic iron oxide particles (USPIO), and positron emission tomography (PET) with the tracer [(11)C]PK11195. METHODS Rats were subjected to permanent middle cerebral artery occlusion (pMCAO) by the macrosphere model and monitored by MRI and PET for 28 or 56 days, followed by immunohistochemical endpoint analysis. To our knowledge, this is the first study providing USPIO-MRI data in the chronic phase up to 8 weeks after stroke. RESULTS Phagocytes with internalized USPIOs induced MRI-T2(∗) signal alterations in the brain. Combined analysis with [(11)C]PK11195-PET allowed quantification of phagocytic activity and other neuroinflammatory processes. From 4 weeks after induction of ischemia, inflammation was dominated by phagocytes. Immunohistochemistry revealed colocalization of Iba1+ microglia with [(11)C]PK11195 and ED1/CD68 with USPIOs. USPIO-related iron was distinguished from alternatively deposited iron by assessing MRI before and after USPIO application. Tissue affected by non-phagocytic inflammation during the first week mostly remained in a viably vital but remodeled state after 4 or 8 weeks, while phagocytic activity was associated with severe injury and necrosis accordingly. CONCLUSIONS We conclude that the combined approach of USPIO-MRI and [(11)C]PK11195-PET allows to observe post-stroke inflammatory processes in the living animal in an intraindividual and longitudinal fashion, predicting long-term tissue fate. The non-invasive imaging methods do not affect the immune system and have been applied to human subjects before. Translation into clinical applications is therefore feasible.
Collapse
|
27
|
|
28
|
PET imaging in ischemic cerebrovascular disease: current status and future directions. Neurosci Bull 2014; 30:713-32. [PMID: 25138055 DOI: 10.1007/s12264-014-1463-y] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2014] [Accepted: 04/10/2014] [Indexed: 01/08/2023] Open
Abstract
Cerebrovascular diseases are caused by interruption or significant impairment of the blood supply to the brain, which leads to a cascade of metabolic and molecular alterations resulting in functional disturbance and morphological damage. These pathophysiological changes can be assessed by positron emission tomography (PET), which permits the regional measurement of physiological parameters and imaging of the distribution of molecular markers. PET has broadened our understanding of the flow and metabolic thresholds critical for the maintenance of brain function and morphology: in this application, PET has been essential in the transfer of the concept of the penumbra (tissue with perfusion below the functional threshold but above the threshold for the preservation of morphology) to clinical stroke and thereby has had great impact on developing treatment strategies. Radioligands for receptors can be used as early markers of irreversible neuronal damage and thereby can predict the size of the final infarcts; this is also important for decisions concerning invasive therapy in large ("malignant") infarctions. With PET investigations, the reserve capacity of blood supply to the brain can be tested in obstructive arteriosclerosis of the supplying arteries, and this again is essential for planning interventions. The effect of a stroke on the surrounding and contralateral primarily unaffected tissue can be investigated, and these results help to understand the symptoms caused by disturbances in functional networks. Chronic cerebrovascular disease causes vascular cognitive disorders, including vascular dementia. PET permits the detection of the metabolic disturbances responsible for cognitive impairment and dementia, and can differentiate vascular dementia from degenerative diseases. It may also help to understand the importance of neuroinflammation after stroke and its interaction with amyloid deposition in the development of dementia. Although the clinical application of PET investigations is limited, this technology had and still has a great impact on research into cerebrovascular diseases.
Collapse
|
29
|
Ribeiro MJ, Vercouillie J, Debiais S, Cottier JP, Bonnaud I, Camus V, Banister S, Kassiou M, Arlicot N, Guilloteau D. Could (18) F-DPA-714 PET imaging be interesting to use in the early post-stroke period? EJNMMI Res 2014; 4:28. [PMID: 25006546 PMCID: PMC4077629 DOI: 10.1186/s13550-014-0028-4] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2014] [Accepted: 05/07/2014] [Indexed: 12/13/2022] Open
Abstract
Background Cerebral stroke is a severe and frequent condition that requires rapid and reliable diagnosis. If administered shortly after the first symptoms manifest themselves, IV thrombolysis has been shown to increase the functional prognosis by restoring brain reperfusion. However, a better understanding of the pathophysiology of stroke should help to identify potential new therapeutic targets. Stroke is known to induce an inflammatory brain reaction that involves overexpression of the 18-kDa translocator protein (TSPO) in glial cells and infiltrated leukocytes, which can be visualised by positron emission tomography (PET). We aimed to evaluate post-stroke neuroinflammation using the PET TSPO radioligand 18 F-DPA-714. Methods Nine patients underwent 18 F-DPA-714 PET and magnetic resonance imaging (MRI) between 8 and 18 days after the ictus. Co-registration of MRI and PET images was used to define three volumes of interest (VOIs): core infarction, contralateral region, and cerebellum ipsilateral to the stroke lesion. Time activity curves were obtained from each VOI, and ratios of mean and maximum activities between the VOIs were calculated. Results We observed an increased uptake of 18 F-DPA-714 co-localised with the infarct tissue and extension beyond the region corresponding to the damage in the blood brain barrier. No correlation was identified between 18 F-DPA-714 uptake and infarct volume. 18 F-DPA-714 uptake in ischemic lesion (mainly associated with TSPO expression in the infarct area and in the surrounding neighbourhood) slowly decreased from 10 min pi to the end of the PET acquisition, remaining higher than that in both contralateral region and ipsilateral cerebellum. Conclusion Our results show that 18 F-DPA-714 uptake after acute ischemia is mainly associated with TSPO expression in the infarct area and in the surrounding neighbourhood. We also demonstrated that the kinetics of 18 F-DPA-714 differs in injured tissue compared to normal tissue. Therefore, 18 F-DPA-714 may be useful in assessing the extent of neuroinflammation associated with acute stroke and could also help to predict clinical outcomes and functional recovery, as well as to assess therapeutic strategies, such as the use of neuroprotective/anti-inflammatory drugs.
Collapse
Affiliation(s)
- Maria-Joao Ribeiro
- Université François Rabelais de Tours, Tours, UMR-S930, France ; Inserm U930, University of Tours, Tours 37000, France ; CHRU Tours, Tours 37000, France ; CIC-IT INSERM 806 Ultrasons et Radiopharmaceutiques, Tours, France ; Service de Médecine Nucléaire, Hôpital Bretonneau, 2, Boulevard Tonnellé, Tours CEDEX 37044, France
| | - Johnny Vercouillie
- Université François Rabelais de Tours, Tours, UMR-S930, France ; Inserm U930, University of Tours, Tours 37000, France
| | | | - Jean-Philippe Cottier
- Université François Rabelais de Tours, Tours, UMR-S930, France ; Inserm U930, University of Tours, Tours 37000, France ; CHRU Tours, Tours 37000, France
| | | | - Vincent Camus
- Université François Rabelais de Tours, Tours, UMR-S930, France ; Inserm U930, University of Tours, Tours 37000, France ; CHRU Tours, Tours 37000, France ; CIC INSERM 202, Tours, France
| | - Samuel Banister
- School of Chemistry, University of Sydney, Sydney 2006, New South Wales, Australia ; Brain and Mind Research Institute, Sydney 2050, New South Wales, Australia
| | - Michael Kassiou
- School of Chemistry, University of Sydney, Sydney 2006, New South Wales, Australia ; Brain and Mind Research Institute, Sydney 2050, New South Wales, Australia ; Discipline of Medical Radiation Sciences, University of Sydney, Sydney 2006, New South Wales, Australia
| | - Nicolas Arlicot
- Université François Rabelais de Tours, Tours, UMR-S930, France ; Inserm U930, University of Tours, Tours 37000, France ; CHRU Tours, Tours 37000, France
| | - Denis Guilloteau
- Université François Rabelais de Tours, Tours, UMR-S930, France ; Inserm U930, University of Tours, Tours 37000, France ; CHRU Tours, Tours 37000, France ; CIC-IT INSERM 806 Ultrasons et Radiopharmaceutiques, Tours, France ; CIC INSERM 202, Tours, France
| |
Collapse
|
30
|
Lai C, Zhou HC, Ma XH, Zhang HX. Quantitative evaluation of the axonal degeneration of central motor neurons in chronic cerebral stroke with diffusion tensor imaging. Acta Radiol 2014; 55:114-20. [PMID: 23873888 DOI: 10.1177/0284185113492456] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Conventional magnetic resonance imaging (MRI) can only show the degeneration-induced morphological changes but fail to quantitatively reveal the degree and extent of the axonal damage of nerve fibers. Diffusion tensor imaging (DTI) has the ability to detect the diffusion of water molecules and thus suitable to the study of axonal degeneration of central motor neurons. PURPOSE To illustrate and quantitatively evaluate the axonal degeneration of central motor neurons in patients with chronic cerebral stroke. MATERIAL AND METHODS DTI and conventional MRI were carried out with 10 normal control subjects and 25 patients who suffered from chronic cerebral stroke in the region supplied by middle cerebral artery and had varying degrees of limb movement disorders (the mean time of onset was 2.5 months), to measure the fractional anisotropy (FA), volume ratio (VR), apparent diffusion coefficient (ADC), tensor eigenvalues (λ1, λ2, and λ3), and signal intensity (SI) on T2-weighted images, of the central motor fibers (pyramidal tract) in the plane of cerebral peduncle. Results from the ipsilateral side were compared with those from the contralateral side in the same patient and with those from normal control. RESULTS The axonal degeneration of central motor neurons manifests in DTI as the decline of FA of the pyramidal tract and the reduction and distortion of the high signal area. While all the FA, VR, ADC, and λ1 in the ipsilateral side reduce on DTI, λ3 increases; the T2-weighted signals exhibit no significant differences among groups. CONCLUSION The changes and diffusions of water molecule associated with the axonal degeneration of central motor neurons after chronic cerebral stroke can be detected by DTI, which can directly quantitatively reflect the degree and extent of axonal degeneration of central motor neurons and can compensate the shortcomings of conventional MRI and diffusion-weighted imaging (DWI).
Collapse
Affiliation(s)
- Can Lai
- Department of Radiology, Children’s Hospital, Zhejiang University School of Medicine, Hangzhou, PR China
| | - Hai-Chun Zhou
- Department of Radiology, Children’s Hospital, Zhejiang University School of Medicine, Hangzhou, PR China
| | - Xiao-Hui Ma
- Department of Radiology, Children’s Hospital, Zhejiang University School of Medicine, Hangzhou, PR China
| | - Hong-Xi Zhang
- Department of Radiology, Children’s Hospital, Zhejiang University School of Medicine, Hangzhou, PR China
| |
Collapse
|
31
|
Tarulli E, Chaudhuri JD, Gretka V, Hoyles A, Morshead CM, Stanisz GJ. Effectiveness of micron-sized superparamagnetic iron oxide particles as markers for detection of migration of bone marrow-derived mesenchymal stromal cells in a stroke model. J Magn Reson Imaging 2014; 37:1409-18. [PMID: 23712844 DOI: 10.1002/jmri.23897] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2011] [Accepted: 09/18/2012] [Indexed: 01/30/2023] Open
Abstract
PURPOSE To evaluate the feasibility of using micron-sized superparamagnetic iron oxide particles (MPIOs) as an effective labeling agent for monitoring bone marrow-derived mesenchymal stromal cell (BMSC) migration in the brain using magnetic resonance imaging (MRI) in a rat model of stroke and whether the accumulation of MPIO-labeled BMSCs can be differentiated from the accumulation of free MPIO particles or hemoglobin breakdown at a site of neuronal damage. MATERIALS AND METHODS In this study BMSCs were labeled with iron oxide and their pattern of migration following intravenous injection in a rat stroke model was monitored using a clinical MRI system followed by standard histopathology. The migration pattern was compared between intravenous injection of BMSCs alone, BMSCs labeled with MPIOs, and MPIO particles alone. RESULTS The results demonstrated that while MRI was highly sensitive in the detection of iron oxide particle-containing cells in areas of neuronal ischemia, the true origin of cells containing iron oxide particles remains ambiguous. Therefore, detection of iron particles may not be a suitable strategy for the detection of BMSCs in the brain in a stroke model. CONCLUSION This study suggests that the use of MPIOs as labeling agents are insufficient to conclusively determine the localization of iron within cells in regions of neuronal ischemia and hemorrhage.
Collapse
Affiliation(s)
- Emidio Tarulli
- Department of Medical Biophysics, University of Toronto, Toronto, Ontario, Canada
| | | | | | | | | | | |
Collapse
|
32
|
Smith CJ, Lawrence CB, Rodriguez-Grande B, Kovacs KJ, Pradillo JM, Denes A. The immune system in stroke: clinical challenges and their translation to experimental research. J Neuroimmune Pharmacol 2013; 8:867-87. [PMID: 23673977 DOI: 10.1007/s11481-013-9469-1] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2012] [Accepted: 04/28/2013] [Indexed: 12/27/2022]
Abstract
Stroke represents an unresolved challenge for both developed and developing countries and has a huge socio-economic impact. Although considerable effort has been made to limit stroke incidence and improve outcome, strategies aimed at protecting injured neurons in the brain have all failed. This failure is likely to be due to both the incompleteness of modelling the disease and its causes in experimental research, and also the lack of understanding of how systemic mechanisms lead to an acute cerebrovascular event or contribute to outcome. Inflammation has been implicated in all forms of brain injury and it is now clear that immune mechanisms profoundly influence (and are responsible for the development of) risk and causation of stroke, and the outcome following the onset of cerebral ischemia. Until very recently, systemic inflammatory mechanisms, with respect to common comorbidities in stroke, have largely been ignored in experimental studies. The main aim is therefore to understand interactions between the immune system and brain injury in order to develop novel therapeutic approaches. Recent data from clinical and experimental research clearly show that systemic inflammatory diseases -such as atherosclerosis, obesity, diabetes or infection - similar to stress and advanced age, are associated with dysregulated immune responses which can profoundly contribute to cerebrovascular inflammation and injury in the central nervous system. In this review, we summarize recent advances in the field of inflammation and stroke, focusing on the challenges of translation between pre-clinical and clinical studies, and potential anti-inflammatory/immunomodulatory therapeutic approaches.
Collapse
Affiliation(s)
- Craig J Smith
- Stroke and Vascular Research Centre, Institute of Cardiovascular Sciences, University of Manchester, Manchester Academic Health Science Centre, Salford Royal Foundation Trust, Salford M6 8HD, UK.
| | | | | | | | | | | |
Collapse
|
33
|
Affiliation(s)
- Wolf-Dieter Heiss
- From the Max Planck Institute for Neurological Research, Cologne, Germany
| |
Collapse
|
34
|
Gulyás B, Tóth M, Schain M, Airaksinen A, Vas Á, Kostulas K, Lindström P, Hillert J, Halldin C. Evolution of microglial activation in ischaemic core and peri-infarct regions after stroke: A PET study with the TSPO molecular imaging biomarker [ C]vinpocetine. J Neurol Sci 2012; 320:110-7. [DOI: 10.1016/j.jns.2012.06.026] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2012] [Revised: 05/03/2012] [Accepted: 06/23/2012] [Indexed: 01/17/2023]
|
35
|
Radlinska BA, Blunk Y, Leppert IR, Minuk J, Pike GB, Thiel A. Changes in callosal motor fiber integrity after subcortical stroke of the pyramidal tract. J Cereb Blood Flow Metab 2012; 32:1515-24. [PMID: 22434071 PMCID: PMC3421088 DOI: 10.1038/jcbfm.2012.37] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
In the healthy brain, there are close correlations between task-related activation of the primary motor cortex (M1), the magnitude of interhemispheric inhibition, and microstructural properties of transcallosal fiber tracts. After subcortical stroke affecting the pyramidal tract (PT), an abnormal pattern of bilateral activity develops in M1. With this prospective longitudinal study, we aimed to determine whether a morphological correlate of poststroke disinhibition could be measured within 20 days and 6 months of PT stroke. Using diffusion tensor imaging with tractography, we delineated transcallosal motor fibers (CMF) in nine PT stroke patients, six patients with subcortical infarct not affecting the PT (NonPT) and six transient ischemic attack patients. We compared changes in CMF fractional anisotropy ratios (rFA) with rFA in a distinct bundle of callosal occipital fibers (COF). At the initial time point, there were no significant differences in rFA between groups and fiber bundles. At follow-up, PT-group rFA(CMF) was significantly lower than PT-group rFA(COF) and NonPT-group rFA(CMF). PT-group rFA(CMF) decreased over time and correlated with rFA of the PT (rFA(PT)) retrograde to the infarct at 6 months. Our data suggest a progressive degenerative transsynaptic effect of PT stroke on CMF, which could be a morphological correlate of transcallosal disinhibition.
Collapse
Affiliation(s)
- Basia A Radlinska
- Department of Neurology and Neurosurgery, Montréal Neurological Institute, Montréal, Quebec, Canada
| | | | | | | | | | | |
Collapse
|
36
|
Qin W, Zhang M, Piao Y, Guo D, Zhu Z, Tian X, Li K, Yu C. Wallerian degeneration in central nervous system: dynamic associations between diffusion indices and their underlying pathology. PLoS One 2012; 7:e41441. [PMID: 22829950 PMCID: PMC3400645 DOI: 10.1371/journal.pone.0041441] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2012] [Accepted: 06/21/2012] [Indexed: 11/24/2022] Open
Abstract
Background Although diffusion tensor imaging has been used to monitor Wallerian degeneration, the exact relationship between the evolution of diffusion indices and its underlying pathology, especially in central nervous system, remains largely unknown. Here we aimed to address this question using a cat Wallerian degeneration model of corticospinal tract. Methodology/Principal Findings Twenty-five domestic mature Felis catus were included in the present study. The evolution of diffusion indices, including mean diffusivity (MD), fractional anisotropy (FA), primary (λ1) and transverse eigenvalues (λ23) of the degenerated corticospinal tract, were observed at baseline (before modeling) and at 2, 4, 6, 8, 10, 15, 20, 25, 30, 45 and 60 days after modeling in 4 cats. Pathological examinations were performed at eight time points mentioned above. Wallerian degeneration can be detected as early as the 2nd day after modeling by both diffusion tensor imaging and pathology. According to the evolution of diffusion indices, Wallerian degeneration can be classified into 2 stages. During the early stage (within 8 days after modeling), progressive disintegration of axons and myelin sheaths underlies the decreases in FA and λ1 and the increase in λ23. However, during the late stage (after 8 days), the gradual increases in FA, MD and λ1 and the unchanged λ23 seem to be a comprehensive reflection of the pathological processes including microglia activation, myelin clearance, and astrocytosis. Conclusions/Significance Our findings help the understanding of the altered diffusion indices in the context of pathology and suggest that diffusion tensor imaging has the potential to monitor the processes of Wallerian degeneration in the central nervous system in vivo after acute damage.
Collapse
Affiliation(s)
- Wen Qin
- Department of Radiology, Tianjin Medical University General Hospital, Tianjin, China
- Department of Radiology, Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Min Zhang
- Department of Radiology, Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Yueshan Piao
- Department of Pathology, Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Deyu Guo
- Department of Experimental Animal, Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Zixin Zhu
- Department of Experimental Animal, Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Xin Tian
- Department of Experimental Animal, Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Kuncheng Li
- Department of Radiology, Xuanwu Hospital, Capital Medical University, Beijing, China
- * E-mail: (KL); (CY)
| | - Chunshui Yu
- Department of Radiology, Tianjin Medical University General Hospital, Tianjin, China
- Department of Radiology, Xuanwu Hospital, Capital Medical University, Beijing, China
- * E-mail: (KL); (CY)
| |
Collapse
|
37
|
Jacobs AH, Tavitian B. Noninvasive molecular imaging of neuroinflammation. J Cereb Blood Flow Metab 2012; 32:1393-415. [PMID: 22549622 PMCID: PMC3390799 DOI: 10.1038/jcbfm.2012.53] [Citation(s) in RCA: 188] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/03/2011] [Revised: 03/05/2012] [Accepted: 03/23/2012] [Indexed: 12/23/2022]
Abstract
Inflammation is a highly dynamic and complex adaptive process to preserve and restore tissue homeostasis. Originally viewed as an immune-privileged organ, the central nervous system (CNS) is now recognized to have a constant interplay with the innate and the adaptive immune systems, where resident microglia and infiltrating immune cells from the periphery have important roles. Common diseases of the CNS, such as stroke, multiple sclerosis (MS), and neurodegeneration, elicit a neuroinflammatory response with the goal to limit the extent of the disease and to support repair and regeneration. However, various disease mechanisms lead to neuroinflammation (NI) contributing to the disease process itself. Molecular imaging is the method of choice to try to decipher key aspects of the dynamic interplay of various inducers, sensors, transducers, and effectors of the orchestrated inflammatory response in vivo in animal models and patients. Here, we review the basic principles of NI with emphasis on microglia and common neurologic disease mechanisms, the molecular targets which are being used and explored for imaging, and molecular imaging of NI in frequent neurologic diseases, such as stroke, MS, neurodegeneration, epilepsy, encephalitis, and gliomas.
Collapse
Affiliation(s)
- Andreas H Jacobs
- European Institute for Molecular Imaging (EIMI) at the Westfalian Wilhelms-University of Münster (WWU), Münster, Germany.
| | | |
Collapse
|
38
|
Affiliation(s)
- Chelsea S Kidwell
- Department of Neurology, Georgetown University, 4000 Reservoir Road, Suite 150, Washington, DC 20007, USA.
| | | |
Collapse
|
39
|
Walimuni IS, Abid H, Hasan KM. A computational framework to quantify tissue microstructural integrity using conventional MRI macrostructural volumetry. Comput Biol Med 2011; 41:1073-81. [PMID: 21130424 DOI: 10.1016/j.compbiomed.2010.10.009] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2010] [Revised: 10/24/2010] [Accepted: 10/26/2010] [Indexed: 10/18/2022]
|
40
|
Affiliation(s)
- Alexander Thiel
- From the Department of Neurology (A.T.), McGill University, Montreal, Canada; Jewish General Hospital (A.T.), Montreal, Canada; and Max-Planck-Institute for Neurological Research (W.-D.H.), Cologne, Germany
| | - Wolf-Dieter Heiss
- From the Department of Neurology (A.T.), McGill University, Montreal, Canada; Jewish General Hospital (A.T.), Montreal, Canada; and Max-Planck-Institute for Neurological Research (W.-D.H.), Cologne, Germany
| |
Collapse
|
41
|
Imaging Brain Microglial Activation Using Positron Emission Tomography and Translocator Protein-Specific Radioligands. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2011; 101:19-39. [DOI: 10.1016/b978-0-12-387718-5.00002-x] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
|
42
|
Nuclear neuroimaging in acute and subacute ischemic stroke. Ann Nucl Med 2010; 24:629-38. [DOI: 10.1007/s12149-010-0421-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2010] [Accepted: 08/12/2010] [Indexed: 10/18/2022]
|
43
|
Arlicot N, Petit E, Katsifis A, Toutain J, Divoux D, Bodard S, Roussel S, Guilloteau D, Bernaudin M, Chalon S. Detection and quantification of remote microglial activation in rodent models of focal ischaemia using the TSPO radioligand CLINDE. Eur J Nucl Med Mol Imaging 2010; 37:2371-80. [PMID: 20814674 DOI: 10.1007/s00259-010-1598-7] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2010] [Accepted: 08/09/2010] [Indexed: 01/09/2023]
Abstract
PURPOSE Neuroinflammation is involved in stroke pathophysiology and might be imaged using radioligands targeting the 18 kDa translocator protein (TSPO). METHODS We studied microglial reaction in brain areas remote from the primary lesion site in two rodent models of focal cerebral ischaemia (permanent or transient) using [125I]-CLINDE, a promising TSPO single photon emission computed tomography radioligand. RESULTS In a mouse model of permanent middle cerebral artery occlusion (MCAO), ex vivo autoradiographic studies demonstrated, besides in the ischaemic territory, accumulation of [125I]-CLINDE in the ipsilateral thalamus with a binding that progressed up to 3 weeks after MCAO. [125I]-CLINDE binding markedly decreased in animals pre-injected with either unlabelled CLINDE or PK11195, while no change was observed with flumazenil pre-treatment, demonstrating TSPO specificity. In rats subjected to transient MCAO, [125I]-CLINDE binding in the ipsilateral thalamus and substantia nigra pars reticulata (SNr) was significantly higher than that in contralateral tissue. Moreover, [125I]-CLINDE binding in the thalamus and SNr was quantitatively correlated to the ischaemic volume assessed by MRI in the cortex and striatum, respectively. CONCLUSION Clinical consequences of secondary neuronal degeneration in stroke might be better treated thanks to the discrimination of neuronal processes using in vivo molecular imaging and potent TSPO radioligands like CLINDE to guide therapeutic interventions.
Collapse
Affiliation(s)
- Nicolas Arlicot
- UMR Inserm U 930, CNRS ERL 3106, Université François Rabelais de Tours, CHRU de Tours, Tours, France.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
44
|
Thiel A, Radlinska BA, Paquette C, Sidel M, Soucy JP, Schirrmacher R, Minuk J. The temporal dynamics of poststroke neuroinflammation: a longitudinal diffusion tensor imaging-guided PET study with 11C-PK11195 in acute subcortical stroke. J Nucl Med 2010; 51:1404-12. [PMID: 20720039 DOI: 10.2967/jnumed.110.076612] [Citation(s) in RCA: 110] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
UNLABELLED Animal experiments suggest that 2 different types of activated microglia (AMG) cells occur in the brain after a stroke: local AMG in the area of the infarct and remote AMG, which occurs along affected fiber tracts. We used (11)C-PK11195 PET to image AMG in vivo after stroke in humans in a prospective longitudinal study to investigate the temporal dynamics of AMG and relate local and remote AMG activity to pyramidal tract (PT) damage using diffusion tensor imaging (DTI). METHODS Eighteen patients underwent DTI-MRI, (11)C-PK11195 PET, and behavioral testing within 2 wk and 6 mo of acute subcortical stroke. In 12 patients, the PT was affected by the stroke (PT group), and in 6 patients it was not (non-PT group). Standardized volumes of interest (VOIs) were placed along the PT at the level of the brain stem, semioval center, and infarct. Tracer uptake ratios (ipsilateral to contralateral) were calculated for each VOI and related to tract damage (measured as fractional anisotropy ratio) and clinical outcome. Six controls underwent the same protocol but only once. RESULTS In both patient groups, local AMG activity in the infarct was increased initially and significantly decreased over the follow-up period. In contrast, remote AMG was detected only in the PT group in the brain stem along the affected tract and persisted during follow-up. No AMG was observed retrograde to the lesion at any time. Remote AMG activity along the affected PT in the brain stem correlated with initial PT damage as measured by DTI in the same tract portion. Local AMG activity in the infarct correlated with anterograde PT damage only at follow-up. After controlling for PT damage, initial AMG activity in the brain stem showed a positive correlation with clinical outcome, whereas persisting AMG activity in the infarct tended to be negatively correlated. CONCLUSION DTI-guided (11)C-PK11195 PET in acute subcortical stroke demonstrates differential temporal dynamics of local and remote AMG. Activity of both types related to anterograde PT damage as measured by DTI and might contribute differently to clinical outcome.
Collapse
Affiliation(s)
- Alexander Thiel
- Department of Neurology and Neurosurgery, McGill University, Montreal, Quebec, Canada.
| | | | | | | | | | | | | |
Collapse
|