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Viviano M, Barresi E, Siméon FG, Costa B, Taliani S, Da Settimo F, Pike VW, Castellano S. Essential Principles and Recent Progress in the Development of TSPO PET Ligands for Neuroinflammation Imaging. Curr Med Chem 2022; 29:4862-4890. [PMID: 35352645 PMCID: PMC10080361 DOI: 10.2174/0929867329666220329204054] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2021] [Revised: 12/21/2021] [Accepted: 01/25/2022] [Indexed: 11/22/2022]
Abstract
The translocator protein 18kDa (TSPO) is expressed in the outer mitochondrial membrane and is implicated in several functions, including cholesterol transport and steroidogenesis. Under normal physiological conditions, TSPO is present in very low concentrations in the human brain but is markedly upregulated in response to brain injury and inflammation. This upregulation is strongly associated with activated microglia. Therefore, TSPO is particularly suited for assessing active gliosis associated with brain lesions following injury or disease. For over three decades, TSPO has been studied as a biomarker. Numerous radioligands for positron emission tomography (PET) that target TSPO have been developed for imaging inflammatory progression in the brain. Although [11C]PK11195, the prototypical first-generation PET radioligand, is still widely used for in vivo studies, mainly now as its single more potent R-enantiomer, it has severe limitations, including low sensitivity and poor amenability to quantification. Second-generation radioligands are characterized by higher TSPO specific signals but suffer from other drawbacks, such as sensitivity to the TSPO single nucleotide polymorphism (SNP) rs6971. Therefore, their applications in human studies have the burden of needing to genotype subjects. Consequently, recent efforts are focused on developing improved radioligands that combine the optimal features of the second generation with the ability to overcome the differences in binding affinities across the population. This review presents essential principles in the design and development of TSPO PET ligands and discusses prominent examples among the main chemotypes.
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Affiliation(s)
- Monica Viviano
- Department of Pharmacy, University of Salerno, 84084 Fisciano (SA), Italy
| | | | - Fabrice G. Siméon
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, MD 20892, USA
| | - Barbara Costa
- Department of Pharmacy, University of Pisa, 56126, Pisa, Italy
| | - Sabrina Taliani
- Department of Pharmacy, University of Pisa, 56126, Pisa, Italy
| | | | - Victor W. Pike
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, MD 20892, USA
| | - Sabrina Castellano
- Department of Pharmacy, University of Salerno, 84084 Fisciano (SA), Italy
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52
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The mitochondrial translocator protein (TSPO): a key multifunctional molecule in the nervous system. Biochem J 2022; 479:1455-1466. [PMID: 35819398 DOI: 10.1042/bcj20220050] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Revised: 06/27/2022] [Accepted: 06/28/2022] [Indexed: 12/12/2022]
Abstract
Translocator protein (TSPO, 18 kDa), formerly known as peripheral benzodiazepine receptor, is an evolutionary well-conserved protein located on the outer mitochondrial membrane. TSPO is involved in a variety of fundamental physiological functions and cellular processes. Its expression levels are regulated under many pathological conditions, therefore, TSPO has been proposed as a tool for diagnostic imaging and an attractive therapeutic drug target in the nervous system. Several synthetic TSPO ligands have thus been explored as agonists and antagonists for innovative treatments as neuroprotective and regenerative agents. In this review, we provide state-of-the-art knowledge of TSPO functions in the brain and peripheral nervous system. Particular emphasis is placed on its contribution to important physiological functions such as mitochondrial homeostasis, energy metabolism and steroidogenesis. We also report how it is involved in neuroinflammation, brain injury and diseases of the nervous system.
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Rupprecht R, Wetzel CH, Dorostkar M, Herms J, Albert NL, Schwarzbach J, Schumacher M, Neumann ID. Translocator protein (18kDa) TSPO: a new diagnostic or therapeutic target for stress-related disorders? Mol Psychiatry 2022; 27:2918-2926. [PMID: 35444254 DOI: 10.1038/s41380-022-01561-3] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/29/2022] [Revised: 03/25/2022] [Accepted: 03/31/2022] [Indexed: 12/11/2022]
Abstract
Efficient treatment of stress-related disorders, such as depression, is still a major challenge. The onset of antidepressant drug action is generally quite slow, while the anxiolytic action of benzodiazepines is considerably faster. However, their long-term use is impaired by tolerance development, abuse liability and cognitive impairment. Benzodiazepines act as positive allosteric modulators of ɣ-aminobutyric acid type A (GABAA) receptors. 3α-reduced neurosteroids such as allopregnanolone also are positive allosteric GABAA receptor modulators, however, through a site different from that targeted by benzodiazepines. Recently, the administration of neurosteroids such as brexanolone or zuranolone has been shown to rapidly ameliorate symptoms in post-partum depression or major depressive disorder. An attractive alternative to the administration of exogenous neurosteroids is promoting endogenous neurosteroidogenesis via the translocator protein 18k Da (TSPO). TSPO is a transmembrane protein located primarily in mitochondria, which mediates numerous biological functions, e.g., steroidogenesis and mitochondrial bioenergetics. TSPO ligands have been used in positron emission tomography (PET) studies as putative markers of microglia activation and neuroinflammation in stress-related disorders. Moreover, TSPO ligands have been shown to modulate neuroplasticity and to elicit antidepressant and anxiolytic therapeutic effects in animals and humans. As such, TSPO may open new avenues for understanding the pathophysiology of stress-related disorders and for the development of novel treatment options.
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Affiliation(s)
- Rainer Rupprecht
- Department of Psychiatry and Psychotherapy, University of Regensburg, 93053, Regensburg, Germany.
| | - Christian H Wetzel
- Department of Psychiatry and Psychotherapy, University of Regensburg, 93053, Regensburg, Germany
| | - Mario Dorostkar
- Center for Neuropathology and Prion Research, Ludwig-Maximilian-University Munich, 81377, Munich, Germany
| | - Jochen Herms
- Center for Neuropathology and Prion Research, Ludwig-Maximilian-University Munich, 81377, Munich, Germany.,German Center for Neurodegenerative Diseases (DZNE), 81377, Munich, Germany.,Munich Cluster for Systems Neurology (SyNergy), 81377, Munich, Germany
| | - Nathalie L Albert
- Department of Nuclear Medicine, Ludwig-Maximilian-University Munich, 81377, Munich, Germany
| | - Jens Schwarzbach
- Department of Psychiatry and Psychotherapy, University of Regensburg, 93053, Regensburg, Germany
| | - Michael Schumacher
- Research Unit 1195, INSERM and University Paris-Saclay, 94276, Le Kremlin-Bicêtre, France
| | - Inga D Neumann
- Department of Neurobiology and Animal Physiology, University Regensburg, 93040, Regensburg, Germany
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54
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Wang K, Wang G, Zhou B. TSPO knockdown attenuates OGD/R-induced neuroinflammation and neural apoptosis by decreasing NLRP3 inflammasome activity through PPARγ pathway. Brain Res Bull 2022; 187:1-10. [PMID: 35738501 DOI: 10.1016/j.brainresbull.2022.06.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Revised: 06/11/2022] [Accepted: 06/17/2022] [Indexed: 11/02/2022]
Abstract
Ischemic stroke is a cerebrovascular disease which is related to brain function loss induced by cerebral ischemia. Translocator protein (TSPO) is an important regulator in inflammatory diseases, while its role in ischemic stroke remains largely unknown. This research aimed to explore the role and action mechanism of TSPO in oxygen-glucose deprivation/reperfusion (OGD/R)-induced neuron cell damage. The differentially expressed genes in ischemic stroke were predicted using GSE140275 dataset, DisGeNet, and GeneCards databases. Differentiated SH-SY5Y cells and primary neurons were subjected to transfection, and stimulated with OGD/R or MCC950 (NLRP3 inhibitor). Proteins were detected by western blotting and ELISA. Cell apoptosis was evaluated through CCK-8, caspase-3 activity and TUNEL assays. TSPO was upregulated in ischemic stroke and in SH-SY5Y cells and primary neurons after OGD/R treatment. TSPO silencing attenuated OGD/R-induced inflammation and apoptosis by decreasing NLRP3 inflammasome activity. TSPO downregulation increased PPARγ expression and decreased HMGB1 expression in OGD/R-treated cells, which was reversed by silencing PPARγ. PPARγ knockdown abolished the effect of TSPO silence on NLRP3 inflammasome activity, inflammation, and cell apoptosis in OGD/R-treated cells, while PPARγ overexpression alleviated OGD/R-induced injury in SH-SY5Y cells. In conclusion, TSPO knockdown attenuates neuroinflammation and neural apoptosis by decreasing NLRP3 inflammasome activity through PPARγ pathway.
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Affiliation(s)
- Kai Wang
- Department of Neurosurgery, The Affiliated Huai'an Hospital of Xuzhou Medical University, The Second People's Hospital of Huai'an, Huai'an 223002, Jiangsu, China.
| | - Gang Wang
- Department of Neurology, Nanshi Hospital of Nanyang, Nanyang 473065, Henan, China.
| | - Botao Zhou
- Department of Neurosurgery, The Second Affiliated Hospital of Xuzhou Medical University, Xuzhou 221006, Jiangsu, China.
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Giridharan VV, Generoso JS, Lence L, Candiotto G, Streck E, Petronilho F, Pillai A, Sharshar T, Dal-Pizzol F, Barichello T. A crosstalk between gut and brain in sepsis-induced cognitive decline. J Neuroinflammation 2022; 19:114. [PMID: 35606817 PMCID: PMC9125851 DOI: 10.1186/s12974-022-02472-4] [Citation(s) in RCA: 27] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Accepted: 05/11/2022] [Indexed: 01/04/2023] Open
Abstract
BACKGROUND Sepsis is a potentially fatal disease characterized by acute organ failure that affects more than 30 million people worldwide. Inflammation is strongly associated with sepsis, and patients can experience impairments in memory, concentration, verbal fluency, and executive functioning after being discharged from the hospital. We hypothesize that sepsis disrupts the microbiota-gut-brain axis homeostasis triggering cognitive impairment. This immune activation persists during treatment, causing neurological dysfunction in sepsis survivors. METHODS To test our hypothesis, adult Wistar rats were subjected to cecal-ligation and perforation (CLP) or sham (non-CLP) surgeries. The animals were subjected to the [11C]PBR28 positron emission tomography (PET)/computed tomography (CT) imaging at 24 h and 10 days after CLP and non-CLP surgeries. At 24 h and 10 days after surgery, we evaluated the gut microbiome, bacterial metabolites, cytokines, microglia, and astrocyte markers. Ten days after sepsis induction, the animals were subjected to the novel object recognition (NOR) and the Morris water maze (MWM) test to assess their learning and memory. RESULTS Compared to the control group, the 24-h and 10-day CLP groups showed increased [11C]PBR28 uptake, glial cells count, and cytokine levels in the brain. Results show that sepsis modulates the gut villus length and crypt depth, alpha and beta microbial diversities, and fecal short-chain fatty acids (SCFAs). In addition, sepsis surviving animals showed a significant cognitive decline compared with the control group. CONCLUSIONS Since several pharmacological studies have failed to prevent cognitive impairment in sepsis survivors, a better understanding of the function of glial cells and gut microbiota can provide new avenues for treating sepsis patients.
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Affiliation(s)
- Vijayasree V Giridharan
- Faillace Department of Psychiatry and Behavioral Sciences, McGovern Medical School, The University of Texas Health Science Center at Houston (UTHealth), Houston, TX, USA
| | - Jaqueline S Generoso
- Laboratory of Experimental Neurology, Graduate Program in Health Sciences, University of Southern Santa Catarina (UNESC), Criciúma, SC, Brazil
| | - Leonardo Lence
- Laboratory of Experimental Neurology, Graduate Program in Health Sciences, University of Southern Santa Catarina (UNESC), Criciúma, SC, Brazil
| | - Gabriela Candiotto
- Laboratory of Neurometabolic Diseases, Graduate Program in Health Sciences, University of Southern Santa Catarina (UNESC), Criciúma, SC, Brazil
| | - Emílio Streck
- Laboratory of Neurometabolic Diseases, Graduate Program in Health Sciences, University of Southern Santa Catarina (UNESC), Criciúma, SC, Brazil
| | - Fabricia Petronilho
- Laboratory of Experimental Neurology, Graduate Program in Health Sciences, University of Southern Santa Catarina (UNESC), Criciúma, SC, Brazil
| | - Anilkumar Pillai
- Pathophysiology of Neuropsychiatric Disorders Program, Faillace Department of Psychiatry and Behavioral Sciences, McGovern Medical School, The University of Texas Health Science Center at Houston (UTHealth), Houston, TX, USA
- Neuroscience Graduate Program, The University of Texas MD Anderson Cancer Center UTHealth Graduate School of Biomedical Sciences, Houston, TX, USA
- Research and Development, Charlie Norwood VA Medical Center, Augusta, GA, USA
- Department of Psychiatry and Health Behavior, Augusta University, Augusta, GA, USA
| | - Tarek Sharshar
- GHU Paris Psychiatrie et Neuroscience, Neurointensive Care and Neuroanesthesia Department, Paris, France
- Université de Paris Cité, Paris, France
- Institute of Psychiatry and Neurosciences of Paris, NSERM UMR 1266, Paris, France
| | - Felipe Dal-Pizzol
- Laboratory of Experimental Pathophysiology, Graduate Program in Health Sciences, University of Southern Santa Catarina (UNESC), Criciuma, SC, Brazil
| | - Tatiana Barichello
- Faillace Department of Psychiatry and Behavioral Sciences, McGovern Medical School, The University of Texas Health Science Center at Houston (UTHealth), Houston, TX, USA.
- Laboratory of Experimental Pathophysiology, Graduate Program in Health Sciences, University of Southern Santa Catarina (UNESC), Criciuma, SC, Brazil.
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56
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Brown RB, Tozer DJ, Loubière L, Hong YT, Fryer TD, Williams GB, Graves MJ, Aigbirhio FI, O’Brien JT, Markus HS. MINocyclinE to Reduce inflammation and blood brain barrier leakage in small Vessel diseAse (MINERVA) trial study protocol. Eur Stroke J 2022; 7:323-330. [PMID: 36082255 PMCID: PMC9445404 DOI: 10.1177/23969873221100338] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2022] [Accepted: 04/24/2022] [Indexed: 11/16/2022] Open
Abstract
Background: Cerebral small vessel disease (SVD) is a common cause of stroke and cognitive impairment. Recent data has implicated neuroinflammation and increased blood-brain barrier (BBB) permeability in its pathogenesis, but whether such processes are causal and can be therapeutically modified is uncertain. In a rodent model of SVD, minocycline was associated with reduced white matter lesions, inflammation and BBB permeability. Aims: To determine whether blood-brain barrier permeability (measured using dynamic contrast-enhanced MRI) and microglial activation (measured by positron emission tomography using the radioligand 11C-PK11195) can be modified in SVD. Design: Phase II randomised double blind, placebo-controlled trial of minocycline 100 mg twice daily for 3 months in 44 participants with moderate to severe SVD defined as a clinical lacunar stroke and confluent white matter hyperintensities. Outcomes: Primary outcome measures are volume and intensity of focal increases of blood-brain barrier permeability and microglial activation determined using PET-MRI imaging. Secondary outcome measures include inflammatory biomarkers in serum, and change in conventional MRI markers and cognitive performance over 1 year follow up. Discussion: The MINERVA trial aims to test whether minocycline can influence novel pathological processes thought to be involved in SVD progression, and will provide insights into whether central nervous system inflammation in SVD can be therapeutically modulated.
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Affiliation(s)
- Robin B Brown
- Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK
| | - Daniel J Tozer
- Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK
| | - Laurence Loubière
- Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK
| | - Young T Hong
- Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK
- Wolfson Brain Imaging Centre, University of Cambridge, Cambridge, UK
| | - Tim D Fryer
- Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK
- Wolfson Brain Imaging Centre, University of Cambridge, Cambridge, UK
| | - Guy B Williams
- Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK
- Wolfson Brain Imaging Centre, University of Cambridge, Cambridge, UK
| | - Martin J Graves
- Department of Radiology, University of Cambridge, Cambridge, UK
| | - Franklin I Aigbirhio
- Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK
- Wolfson Brain Imaging Centre, University of Cambridge, Cambridge, UK
| | - John T O’Brien
- Department of Psychiatry, University of Cambridge, Cambridge, UK
| | - Hugh S Markus
- Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK
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57
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Ren W, Ji B, Guan Y, Cao L, Ni R. Recent Technical Advances in Accelerating the Clinical Translation of Small Animal Brain Imaging: Hybrid Imaging, Deep Learning, and Transcriptomics. Front Med (Lausanne) 2022; 9:771982. [PMID: 35402436 PMCID: PMC8987112 DOI: 10.3389/fmed.2022.771982] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Accepted: 02/16/2022] [Indexed: 12/26/2022] Open
Abstract
Small animal models play a fundamental role in brain research by deepening the understanding of the physiological functions and mechanisms underlying brain disorders and are thus essential in the development of therapeutic and diagnostic imaging tracers targeting the central nervous system. Advances in structural, functional, and molecular imaging using MRI, PET, fluorescence imaging, and optoacoustic imaging have enabled the interrogation of the rodent brain across a large temporal and spatial resolution scale in a non-invasively manner. However, there are still several major gaps in translating from preclinical brain imaging to the clinical setting. The hindering factors include the following: (1) intrinsic differences between biological species regarding brain size, cell type, protein expression level, and metabolism level and (2) imaging technical barriers regarding the interpretation of image contrast and limited spatiotemporal resolution. To mitigate these factors, single-cell transcriptomics and measures to identify the cellular source of PET tracers have been developed. Meanwhile, hybrid imaging techniques that provide highly complementary anatomical and molecular information are emerging. Furthermore, deep learning-based image analysis has been developed to enhance the quantification and optimization of the imaging protocol. In this mini-review, we summarize the recent developments in small animal neuroimaging toward improved translational power, with a focus on technical improvement including hybrid imaging, data processing, transcriptomics, awake animal imaging, and on-chip pharmacokinetics. We also discuss outstanding challenges in standardization and considerations toward increasing translational power and propose future outlooks.
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Affiliation(s)
- Wuwei Ren
- School of Information Science and Technology, ShanghaiTech University, Shanghai, China
- Shanghai Engineering Research Center of Energy Efficient and Custom AI IC, Shanghai, China
| | - Bin Ji
- Department of Radiopharmacy and Molecular Imaging, School of Pharmacy, Fudan University, Shanghai, China
| | - Yihui Guan
- PET Center, Huashan Hospital, Fudan University, Shanghai, China
| | - Lei Cao
- Shanghai Changes Tech, Ltd., Shanghai, China
| | - Ruiqing Ni
- Institute for Regenerative Medicine, University of Zurich, Zurich, Switzerland
- Institute for Biomedical Engineering, ETH Zürich and University of Zurich, Zurich, Switzerland
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58
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Masrori P, Beckers J, Gossye H, Van Damme P. The role of inflammation in neurodegeneration: novel insights into the role of the immune system in C9orf72 HRE-mediated ALS/FTD. Mol Neurodegener 2022; 17:22. [PMID: 35303907 PMCID: PMC8932121 DOI: 10.1186/s13024-022-00525-z] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Accepted: 02/25/2022] [Indexed: 12/13/2022] Open
Abstract
Neuroinflammation is an important hallmark of amyotrophic lateral sclerosis (ALS) and frontotemporal lobar degeneration (FTLD). An inflammatory reaction to neuronal injury is deemed vital for neuronal health and homeostasis. However, a continued activation of the inflammatory response can be detrimental to remaining neurons and aggravate the disease process. Apart from a disease modifying role, some evidence suggests that neuroinflammation may also contribute to the upstream cause of the disease. In this review, we will first focus on the role of neuroinflammation in the pathogenesis of chromosome 9 open reading frame 72 gene (C9orf72) hexanucleotide repeat expansions (HRE)-mediated ALS/FTD (C9-ALS/FTD). Additionally, we will discuss evidence from ex vivo and in vivo studies and finally, we briefly summarize the trials and progress of anti-inflammatory therapies.
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Affiliation(s)
- Pegah Masrori
- Department of Neurosciences, Experimental Neurology, and Leuven Brain Institute (LBI), KU Leuven-University of Leuven, 3000, Leuven, Belgium.,Laboratory of Neurobiology, Experimental Neurology, Center for Brain and Disease Research, VIB, Campus Gasthuisberg, O&N5, Herestraat 49, 602, 3000, Leuven, PB, Belgium.,Neurology Department, University Hospitals Leuven, Campus Gasthuisberg, Herestraat 49, 3000, Leuven, Belgium.,Department of Neurology, University Hospital Antwerp, 2650, Edegem, Belgium
| | - Jimmy Beckers
- Department of Neurosciences, Experimental Neurology, and Leuven Brain Institute (LBI), KU Leuven-University of Leuven, 3000, Leuven, Belgium.,Laboratory of Neurobiology, Experimental Neurology, Center for Brain and Disease Research, VIB, Campus Gasthuisberg, O&N5, Herestraat 49, 602, 3000, Leuven, PB, Belgium
| | - Helena Gossye
- Department of Neurology, University Hospital Antwerp, 2650, Edegem, Belgium.,VIB Center for Molecular Neurology, Neurodegenerative Brain Diseases, University of Antwerp, 2000, Antwerp, Belgium.,Department of Biomedical Sciences, University of Antwerp, 2000, Antwerp, Belgium
| | - Philip Van Damme
- Department of Neurosciences, Experimental Neurology, and Leuven Brain Institute (LBI), KU Leuven-University of Leuven, 3000, Leuven, Belgium. .,Laboratory of Neurobiology, Experimental Neurology, Center for Brain and Disease Research, VIB, Campus Gasthuisberg, O&N5, Herestraat 49, 602, 3000, Leuven, PB, Belgium. .,Neurology Department, University Hospitals Leuven, Campus Gasthuisberg, Herestraat 49, 3000, Leuven, Belgium.
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Varlow C, Knight AC, McQuade P, Vasdev N. Characterization of neuroinflammatory positron emission tomography biomarkers in chronic traumatic encephalopathy. Brain Commun 2022; 4:fcac019. [PMID: 35198978 PMCID: PMC8856182 DOI: 10.1093/braincomms/fcac019] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Revised: 11/10/2021] [Accepted: 02/01/2022] [Indexed: 11/12/2022] Open
Abstract
Chronic traumatic encephalopathy is a neurological disorder associated with head trauma and is confirmed upon autopsy. PET imaging of chronic traumatic encephalopathy may provide a means to move towards ante-mortem diagnosis and therapeutic intervention following brain injuries. Characterization of the neuroinflammatory PET biomarkers, 18 kDa translocator protein and monoamine oxidase-B was conducted using [3H]PBR-28 and [3H]L-deprenyl, respectively, in post-mortem chronic traumatic encephalopathy brain tissue. [3H]PBR-28 displayed high specific binding in both chronic traumatic encephalopathy (95.40 ± 1.87%; n = 11 cases) and healthy controls (89.89 ± 8.52%, n = 3 cases). Cell-type expression of the 18 kDa translocator protein was confirmed by immunofluorescence to microglia, astrocyte and macrophage markers. [3H]L-deprenyl also displayed high specific binding in chronic traumatic encephalopathy (96.95 ± 1.43%; n = 12 cases) and healthy controls (93.24 ± 0.43%; n = 2 cases), with the distribution co-localized to astrocytes by immunofluorescence. Saturation analysis was performed to quantify the target density of the 18 kDa translocator protein and monoamine oxidase-B in both chronic traumatic encephalopathy and healthy control tissue. Using [3H]PBR-28, the target density of the 18 kDa translocator protein in healthy controls was 177.91 ± 56.96 nM (n = 7 cases; mean ± standard deviation); however, a highly variable target density (345.84 ± 372.42 nM; n = 11 cases; mean ± standard deviation) was measured in chronic traumatic encephalopathy. [3H]L-deprenyl quantified a monoamine oxidase-B target density of 304.23 ± 115.93 nM (n = 8 cases; mean ± standard deviation) in healthy control tissue and is similar to the target density in chronic traumatic encephalopathy tissues (365.80 ± 128.55 nM; n = 12 cases; mean ± standard deviation). A two-sample t-test determined no significant difference in the target density values of the 18 kDa translocator protein and monoamine oxidase-B between healthy controls and chronic traumatic encephalopathy (P > 0.05), albeit a trend towards increased expression of both targets was observed in chronic traumatic encephalopathy. To our knowledge, this work represents the first in vitro characterization of 18 kDa translocator protein and monoamine oxidase-B in chronic traumatic encephalopathy and reveals the variability in neuroinflammatory pathology following brain injuries. These preliminary findings will be considered when designing PET imaging studies after brain injury and for the ultimate goal of imaging chronic traumatic encephalopathy in vivo.
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Affiliation(s)
- Cassis Varlow
- Azrieli Centre for Neuro-Radiochemistry, Brain Health Imaging Centre, Centre for Addiction and Mental Health, Toronto, ON, Canada M5T 1R8
- Institute of Medical Science, University of Toronto, Toronto, ON, Canada M5S 1A8
| | - Ashley C. Knight
- Azrieli Centre for Neuro-Radiochemistry, Brain Health Imaging Centre, Centre for Addiction and Mental Health, Toronto, ON, Canada M5T 1R8
- Institute of Medical Science, University of Toronto, Toronto, ON, Canada M5S 1A8
| | - Paul McQuade
- Takeda Pharmaceutical Company, Cambridge, MA 02139, USA
| | - Neil Vasdev
- Azrieli Centre for Neuro-Radiochemistry, Brain Health Imaging Centre, Centre for Addiction and Mental Health, Toronto, ON, Canada M5T 1R8
- Institute of Medical Science, University of Toronto, Toronto, ON, Canada M5S 1A8
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60
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Gouilly D, Saint-Aubert L, Ribeiro MJ, Salabert AS, Tauber C, Péran P, Arlicot N, Pariente J, Payoux P. Neuroinflammation PET imaging of the translocator protein (TSPO) in Alzheimer's disease: an update. Eur J Neurosci 2022; 55:1322-1343. [PMID: 35083791 DOI: 10.1111/ejn.15613] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Revised: 01/18/2022] [Accepted: 01/19/2022] [Indexed: 11/28/2022]
Abstract
Neuroinflammation is a significant contributor to Alzheimer's disease (AD). Until now, PET imaging of the translocator protein (TSPO) has been widely used to depict the neuroimmune endophenotype of AD. The aim of this review was to provide an update to the results from 2018 and to advance the characterization of the biological basis of TSPO imaging in AD by re-examining TSPO function and expression and the methodological aspects of interest. Although the biological basis of the TSPO PET signal is obviously related to microglia and astrocytes in AD, the observed process remains uncertain and might not be directly related to neuroinflammation. Further studies are required to re-examine the cellular significance underlying a variation in the PET signal in AD and how it can be impacted by a disease-modifying treatment.
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Affiliation(s)
- Dominique Gouilly
- ToNIC, Toulouse NeuroImaging Center, Université de Toulouse, Inserm, UPS, France
| | - Laure Saint-Aubert
- ToNIC, Toulouse NeuroImaging Center, Université de Toulouse, Inserm, UPS, France
| | - Maria-Joao Ribeiro
- Department of Nuclear Medicine, CHU, Tours, France.,UMR 1253, iBrain, Université de Tours, France.,Inserm CIC 1415, CHRU, Tours, France
| | - Anne-Sophie Salabert
- ToNIC, Toulouse NeuroImaging Center, Université de Toulouse, Inserm, UPS, France.,Department of Nuclear Medicine, CHU, Toulouse, France
| | | | - Patrice Péran
- ToNIC, Toulouse NeuroImaging Center, Université de Toulouse, Inserm, UPS, France
| | - Nicolas Arlicot
- UMR 1253, iBrain, Université de Tours, France.,Inserm CIC 1415, CHRU, Tours, France
| | - Jérémie Pariente
- ToNIC, Toulouse NeuroImaging Center, Université de Toulouse, Inserm, UPS, France.,Department of Cognitive Neurology, Epilepsy and Movement Disorders, CHU, Toulouse, France.,Center of Clinical Investigations (CIC1436), CHU, Toulouse, France
| | - Pierre Payoux
- ToNIC, Toulouse NeuroImaging Center, Université de Toulouse, Inserm, UPS, France.,Department of Nuclear Medicine, CHU, Toulouse, France
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Freyssin A, Rioux Bilan A, Fauconneau B, Galineau L, Serrière S, Tauber C, Perrin F, Guillard J, Chalon S, Page G. Trans ε-Viniferin Decreases Amyloid Deposits With Greater Efficiency Than Resveratrol in an Alzheimer's Mouse Model. Front Neurosci 2022; 15:803927. [PMID: 35069106 PMCID: PMC8770934 DOI: 10.3389/fnins.2021.803927] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2021] [Accepted: 12/14/2021] [Indexed: 11/25/2022] Open
Abstract
In a previous study, we showed that viniferin decreased amyloid deposits and reduced neuroinflammation in APPswePS1dE9 transgenic mice between 3 and 6 months of age. In the present study, wild type and APPswePS1dE9 transgenic mice were treated from 7 to 11 or from 3 to 12 months by a weekly intraperitoneal injection of either 20 mg/kg viniferin or resveratrol or their vehicle, the polyethylene glycol 200 (PEG 200). The cognitive status of the mice was evaluated by the Morris water maze test. Then, amyloid burden and neuroinflammation were quantified by western-blot, Enzyme-Linked ImmunoSorbent Assay (ELISA), immunofluorescence, and in vivo micro-Positon Emission Tomography (PET) imaging. Viniferin decreased hippocampal amyloid load and deposits with greater efficiency than resveratrol, and both treatments partially prevented the cognitive decline. Furthermore, a significant decrease in brain uptake of the TSPO PET tracer [18F]DPA-714 was observed with viniferin compared to resveratrol. Expression of GFAP, IBA1, and IL-1β were decreased by viniferin but PEG 200, which was very recently shown to be a neuroinflammatory inducer, masked the neuroprotective power of viniferin.
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Affiliation(s)
- Aline Freyssin
- EA3808 Neurovascular Unit and Cognitive Disorders, University of Poitiers, Poitiers, France
| | - Agnès Rioux Bilan
- EA3808 Neurovascular Unit and Cognitive Disorders, University of Poitiers, Poitiers, France
| | - Bernard Fauconneau
- EA3808 Neurovascular Unit and Cognitive Disorders, University of Poitiers, Poitiers, France
| | - Laurent Galineau
- UMR 1253, iBrain, Inserm, Faculty of Medicine, Université de Tours, Tours, France
| | - Sophie Serrière
- UMR 1253, iBrain, Inserm, Faculty of Medicine, Université de Tours, Tours, France
| | - Clovis Tauber
- UMR 1253, iBrain, Inserm, Faculty of Medicine, Université de Tours, Tours, France
| | - Flavie Perrin
- UMR CNRS 7285 IC2MP, Team 5 Organic Synthesis, University of Poitiers, Poitiers, France
| | - Jérôme Guillard
- UMR CNRS 7285 IC2MP, Team 5 Organic Synthesis, University of Poitiers, Poitiers, France
| | - Sylvie Chalon
- UMR 1253, iBrain, Inserm, Faculty of Medicine, Université de Tours, Tours, France
| | - Guylène Page
- EA3808 Neurovascular Unit and Cognitive Disorders, University of Poitiers, Poitiers, France
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62
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Cao L, Kong Y, Ji B, Ren Y, Guan Y, Ni R. Positron Emission Tomography in Animal Models of Tauopathies. Front Aging Neurosci 2022; 13:761913. [PMID: 35082657 PMCID: PMC8784812 DOI: 10.3389/fnagi.2021.761913] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2021] [Accepted: 11/30/2021] [Indexed: 12/18/2022] Open
Abstract
The microtubule-associated protein tau (MAPT) plays an important role in Alzheimer's disease and primary tauopathy diseases. The abnormal accumulation of tau contributes to the development of neurotoxicity, inflammation, neurodegeneration, and cognitive deficits in tauopathy diseases. Tau synergically interacts with amyloid-beta in Alzheimer's disease leading to detrimental consequence. Thus, tau has been an important target for therapeutics development for Alzheimer's disease and primary tauopathy diseases. Tauopathy animal models recapitulating the tauopathy such as transgenic, knock-in mouse and rat models have been developed and greatly facilitated the understanding of disease mechanisms. The advance in PET and imaging tracers have enabled non-invasive detection of the accumulation and spread of tau, the associated microglia activation, metabolic, and neurotransmitter receptor alterations in disease animal models. In vivo microPET studies on mouse or rat models of tauopathy have provided significant insights into the phenotypes and time course of pathophysiology of these models and allowed the monitoring of treatment targeting at tau. In this study, we discuss the utilities of PET and recently developed tracers for evaluating the pathophysiology in tauopathy animal models. We point out the outstanding challenges and propose future outlook in visualizing tau-related pathophysiological changes in brain of tauopathy disease animal models.
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Affiliation(s)
- Lei Cao
- Institute for Regenerative Medicine, University of Zurich, Zurich, Switzerland
- Changes Technology Corporation Ltd., Shanghai, China
| | - Yanyan Kong
- PET Center, Huashan Hospital, Fudan University, Shanghai, China
| | - Bin Ji
- Department of Radiopharmacy and Molecular Imaging, School of Pharmacy, Fudan University, Shanghai, China
| | - Yutong Ren
- Guangdong Robotics Association, Guangzhou, China
| | - Yihui Guan
- PET Center, Huashan Hospital, Fudan University, Shanghai, China
| | - Ruiqing Ni
- Institute for Regenerative Medicine, University of Zurich, Zurich, Switzerland
- Institute for Biomedical Engineering, ETH Zurich and University of Zurich, Zurich, Switzerland
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63
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Nylund M, Sucksdorff M, Matilainen M, Polvinen E, Tuisku J, Airas L. Phenotyping of multiple sclerosis lesions according to innate immune cell activation using 18 kDa translocator protein-PET. Brain Commun 2022; 4:fcab301. [PMID: 34993478 PMCID: PMC8727984 DOI: 10.1093/braincomms/fcab301] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Revised: 10/22/2021] [Accepted: 10/29/2021] [Indexed: 12/27/2022] Open
Abstract
Chronic active lesions are promotors of neurodegeneration and disease progression in multiple sclerosis. They harbour a dense rim of activated innate immune cells at the lesion edge, which promotes lesion growth and thereby induces damage. Conventional MRI is of limited help in identifying the chronic active lesions, so alternative imaging modalities are needed. Objectives were to develop a PET-based automated analysis method for phenotyping of chronic lesions based on lesion-associated innate immune cell activation and to comprehensively evaluate the prevalence of these lesions in the various clinical subtypes of multiple sclerosis, and their association with disability. In this work, we use 18 kDa translocator protein-PET imaging for phenotyping chronic multiple sclerosis lesions at a large scale. For this, we identified 1510 white matter T1-hypointense lesions from 91 multiple sclerosis patients (67 relapsing–remitting patients and 24 secondary progressive patients). Innate immune cell activation at the lesion rim was measured using PET imaging and the 18 kDa translocator protein-binding radioligand 11C-PK11195. A T1-hypointense lesion was classified as rim-active if the distribution volume ratio of 11C-PK11195-binding was low in the plaque core and considerably higher at the plaque edge. If no significant ligand binding was observed, the lesion was classified as inactive. Plaques that had considerable ligand binding both in the core and at the rim were classified as overall-active. Conventional MRI and disability assessment using the Expanded Disability Status Scale were performed at the time of PET imaging. In the secondary progressive cohort, an average of 19% (median, interquartile range: 11–26) of T1 lesions were rim-active in each individual patient, compared to 10% (interquartile range: 0–20) among relapsing–remitting patients (P = 0.009). Secondary progressive patients had a median of 3 (range: 0–11) rim-active lesions, versus 1 (range: 0–18) among relapsing–remitting patients (P = 0.029). Among those patients who had rim-active lesions (n = 63), the average number of active voxels at the rim was higher among secondary progressive compared to relapsing–remitting patients (median 158 versus 74; P = 0.022). The number of active voxels at the rim correlated significantly with the Expanded Disability Status Scale (R = 0.43, P < 0.001), and the volume of the rim-active lesions similarly correlated with the Expanded Disability Status Scale (R = 0.45, P < 0.001). Our study is the first to report in vivo phenotyping of chronic lesions at large scale, based on 18 kDa translocator protein-PET. Patients with higher disability displayed a higher proportion of rim-active lesions. The in vivo lesion phenotyping methodology offers a new tool for individual assessment of smouldering (rim-active) lesion burden.
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Affiliation(s)
- Marjo Nylund
- Turku PET Centre, Turku, Finland.,Clinical Neurosciences, University of Turku, Turku, Finland.,Neurocenter, Turku University Hospital, Turku, Finland
| | - Marcus Sucksdorff
- Turku PET Centre, Turku, Finland.,Clinical Neurosciences, University of Turku, Turku, Finland.,Neurocenter, Turku University Hospital, Turku, Finland
| | - Markus Matilainen
- Turku PET Centre, Turku, Finland.,Faculty of Science and Engineering, Åbo Akademi University, Turku, Finland
| | - Eero Polvinen
- Turku PET Centre, Turku, Finland.,Clinical Neurosciences, University of Turku, Turku, Finland.,Neurocenter, Turku University Hospital, Turku, Finland
| | | | - Laura Airas
- Turku PET Centre, Turku, Finland.,Clinical Neurosciences, University of Turku, Turku, Finland.,Neurocenter, Turku University Hospital, Turku, Finland
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Hu C, Li H, Li J, Luo X, Hao Y. Microglia: Synaptic modulator in autism spectrum disorder. Front Psychiatry 2022; 13:958661. [PMID: 36465285 PMCID: PMC9714329 DOI: 10.3389/fpsyt.2022.958661] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Accepted: 10/28/2022] [Indexed: 11/18/2022] Open
Abstract
Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterized by variable impairment of social communication and repetitive behaviors, highly restricted interests, and/or sensory behaviors beginning early in life. Many individuals with ASD have dysfunction of microglia, which may be closely related to neuroinflammation, making microglia play an important role in the pathogenesis of ASD. Mounting evidence indicates that microglia, the resident immune cells of the brain, are required for proper brain function, especially in the maintenance of neuronal circuitry and control of behavior. Dysfunction of microglia will ultimately affect the neural function in a variety of ways, including the formation of synapses and alteration of excitatory-inhibitory balance. In this review, we provide an overview of how microglia actively interact with neurons in physiological conditions and modulate the fate and functions of synapses. We put a spotlight on the multi-dimensional neurodevelopmental roles of microglia, especially in the essential influence of synapses, and discuss how microglia are currently thought to influence ASD progression.
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Affiliation(s)
- Cong Hu
- Division of Child Healthcare, Department of Pediatrics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Heli Li
- Division of Child Healthcare, Department of Pediatrics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Jinhui Li
- Division of Child Healthcare, Department of Pediatrics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Xiaoping Luo
- Department of Pediatrics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Yan Hao
- Division of Child Healthcare, Department of Pediatrics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
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65
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The 18 kDa translocator protein is associated with microglia in the hippocampus of non-demented elderly subjects. AGING BRAIN 2022; 2:100045. [PMID: 36908874 PMCID: PMC9997180 DOI: 10.1016/j.nbas.2022.100045] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2022] [Revised: 06/22/2022] [Accepted: 06/24/2022] [Indexed: 11/23/2022] Open
Abstract
Increase in the brain expression of the 18 kDa translocator protein (TSPO) is considered as a marker of neuroinflammation in the context of brain diseases, such as Alzheimer's disease (AD). However, in non-demented subjects with Alzheimer's neuropathology, TSPO accumulation in hippocampus subdivisions has not been fully characterized. To determine if TSPO is associated with the presence of amyloid β plaques and/or phosphorylated Tau accumulation, we analyzed hippocampal sections using immunohistochemistry of 14 non-demented subjects with positive staining for Aβ and/or phosphorylated Tau. TSPO expression was heterogenous with higher accumulation in the CA2/3 and subiculum subfields of the hippocampus. Its distribution closely resembled that of the microglial IBA1 marker and of the Aβ42 amyloid form. In addition, positive correlations were observed between TSPO and IBA1 densities in CA4, CA2/3 and the subiculum but not with either the astrocyte GFAP marker or the AD-type Aβ and Tau markers. This study sustains the hypothesis that TSPO is mainly associated with microglia and in Aβ42-rich subdivisions in the hippocampus of non-demented elderly individuals.
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66
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Jia H, Xie T. Tracers progress for positron emission tomography imaging of glial-related disease. J Biomed Res 2022; 36:321-335. [PMID: 36131689 PMCID: PMC9548440 DOI: 10.7555/jbr.36.20220017] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Glial cells play an essential part in the neuron system. They can not only serve as structural blocks in the human brain but also participate in many biological processes. Extensive studies have shown that astrocytes and microglia play an important role in neurodegenerative diseases, such as Alzheimer's disease, Parkinson's disease, Huntington's disease, as well as glioma, epilepsy, ischemic stroke, and infections. Positron emission tomography is a functional imaging technique providing molecular-level information before anatomic changes are visible and has been widely used in many above-mentioned diseases. In this review, we focus on the positron emission tomography tracers used in pathologies related to glial cells, such as glioma, Alzheimer's disease, and neuroinflammation.
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Affiliation(s)
- Haoran Jia
- Institute of Radiation Medicine, Fudan University, Shanghai 200032, China
| | - Tianwu Xie
- Institute of Radiation Medicine, Fudan University, Shanghai 200032, China
- Tianwu Xie, Institute of Radiation Medicine, Fudan University, 2094 Xietu Road, Shanghai 200032, China. Tel: +86-21-64048363, E-mail:
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67
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Joo YH, Lee MW, Son YD, Chang KA, Yaqub M, Kim HK, Cumming P, Kim JH. In Vivo Cerebral Translocator Protein (TSPO) Binding and Its Relationship with Blood Adiponectin Levels in Treatment-Naïve Young Adults with Major Depression: A [ 11C]PK11195 PET Study. Biomedicines 2021; 10:biomedicines10010034. [PMID: 35052718 PMCID: PMC8773340 DOI: 10.3390/biomedicines10010034] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2021] [Revised: 12/05/2021] [Accepted: 12/20/2021] [Indexed: 12/15/2022] Open
Abstract
Adiponectin is an adipokine that mediates cellular cholesterol efflux and plays important roles in neuroinflammatory processes. In this study, we undertook positron emission tomography (PET) with the translocator protein (TSPO) ligand [11C]PK11195 and measured serum adiponectin levels in groups of treatment-naïve young adult patients with major depressive disorder (MDD) and matched healthy controls. Thirty treatment-naïve MDD patients (median age: 24 years) and twenty-three healthy controls underwent [11C]PK11195 PET. We quantified TSPO availability in brain as the [11C]PK11195 binding potential (BPND) using a reference tissue model in conjunction with the supervised cluster analysis (SVCA4) algorithm. Age, sex distribution, body mass index, and serum adiponectin levels did not differ between the groups. Between-group analysis using a region-of-interest approach showed significantly higher [11C]PK11195 BPND in the left anterior and right posterior cingulate cortices in MDD patients than in controls. Serum adiponectin levels had significant negative correlations with [11C]PK11195 BPND in the bilateral hippocampus in MDD patients, but significant positive correlations in the bilateral hippocampus in the control group. Our results indicate significantly higher TSPO binding in the anterior and posterior cingulate cortices in treatment-naïve young MDD patients, suggesting microglial activation in these limbic regions, which are involved in cognitive and emotional processing. The opposite correlations between [11C]PK11195 BPND in the hippocampus with serum adiponectin levels in MDD and control groups suggest that microglial activation in the hippocampus may respond differentially to adiponectin signaling in MDD and healthy subjects, possibly with respect to microglial phenotype.
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Affiliation(s)
- Yo-Han Joo
- Neuroscience Research Institute, Gachon University, Incheon 21565, Korea; (Y.-H.J.); (M.-W.L.); (Y.-D.S.); (K.-A.C.); (H.-K.K.)
| | - Min-Woo Lee
- Neuroscience Research Institute, Gachon University, Incheon 21565, Korea; (Y.-H.J.); (M.-W.L.); (Y.-D.S.); (K.-A.C.); (H.-K.K.)
| | - Young-Don Son
- Neuroscience Research Institute, Gachon University, Incheon 21565, Korea; (Y.-H.J.); (M.-W.L.); (Y.-D.S.); (K.-A.C.); (H.-K.K.)
- Department of Biomedical Engineering, College of Health Science, Gachon University, Incheon 21936, Korea
- Gachon Advanced Institute for Health Science and Technology, Graduate School, Gachon University, Incheon 21565, Korea
| | - Keun-A Chang
- Neuroscience Research Institute, Gachon University, Incheon 21565, Korea; (Y.-H.J.); (M.-W.L.); (Y.-D.S.); (K.-A.C.); (H.-K.K.)
- Gachon Advanced Institute for Health Science and Technology, Graduate School, Gachon University, Incheon 21565, Korea
- Department of Pharmacology, Gachon University College of Medicine, Gachon University, Incheon 21936, Korea
| | - Maqsood Yaqub
- Department of Radiology and Nuclear Medicine, Amsterdam University Medical Centers, 1081 HV Amsterdam, The Netherlands;
| | - Hang-Keun Kim
- Neuroscience Research Institute, Gachon University, Incheon 21565, Korea; (Y.-H.J.); (M.-W.L.); (Y.-D.S.); (K.-A.C.); (H.-K.K.)
- Department of Biomedical Engineering, College of Health Science, Gachon University, Incheon 21936, Korea
- Gachon Advanced Institute for Health Science and Technology, Graduate School, Gachon University, Incheon 21565, Korea
| | - Paul Cumming
- Department of Nuclear Medicine, Inselspital, Bern University, CH-3010 Bern, Switzerland;
- School of Psychology and Counselling, Queensland University of Technology, Brisbane 4059, Australia
| | - Jong-Hoon Kim
- Neuroscience Research Institute, Gachon University, Incheon 21565, Korea; (Y.-H.J.); (M.-W.L.); (Y.-D.S.); (K.-A.C.); (H.-K.K.)
- Gachon Advanced Institute for Health Science and Technology, Graduate School, Gachon University, Incheon 21565, Korea
- Department of Psychiatry, Gachon University College of Medicine, Gil Medical Center, Gachon University, Incheon 21565, Korea
- Correspondence: ; Tel.: +82-32-460-2696
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α-Synuclein Overexpression Increases Dopamine D2/3 Receptor Binding and Immune Activation in a Model of Early Parkinson’s Disease. Biomedicines 2021; 9:biomedicines9121876. [PMID: 34944691 PMCID: PMC8698691 DOI: 10.3390/biomedicines9121876] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2021] [Revised: 12/01/2021] [Accepted: 12/07/2021] [Indexed: 12/14/2022] Open
Abstract
Progressive degeneration of dopaminergic neurons, immune activation, and α-synuclein pathology characterize Parkinson’s disease (PD). We previously reported that unilateral intranigral injection of recombinant adeno-associated viral (rAAV) vectors encoding wild-type human α-synuclein produced a rat model of early PD with dopamine terminal dysfunction. Here we tested the hypothesis that decreases in dopamine result in increased postsynaptic dopamine D2/D3 receptor expression, neuroinflammation, and reduced synaptic vesicle glycoprotein 2A (SV2A) density. Rats were injected with rAAV encoding α-synuclein or green fluorescent protein and subjected to non-pharmacological motor tests, before euthanization at 12 weeks post-injection. We performed: (1) in situ hybridization of nigral tyrosine hydroxylase mRNA, (2) HPLC of striatal dopamine content, and (3) autoradiography with [3H]raclopride, [3H]DTBZ, [3H]GBR12935, [3H]PK11195, and [3H]UCB-J to measure binding at D2/3 receptors, vesicular monoamine transporter 2, dopamine transporters, mitochondrial translocator protein, and SV2A, respectively. rAAV-α-synuclein induced motor asymmetry and reduced tyrosine hydroxylase mRNA and dopamine content in ipsilateral brain regions. This was paralleled by elevated ipsilateral postsynaptic dopamine D2/3 receptor expression and immune activation, with no changes to synaptic SV2A density. In conclusion, α-synuclein overexpression results in dopaminergic degeneration that induced compensatory increases in D2/3 binding and immune activation, recapitulating many of the pathological characteristics of PD.
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69
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Leroy C, Saba W. Contribution of TSPO imaging in the understanding of the state of gliosis in substance use disorders. Eur J Nucl Med Mol Imaging 2021; 49:186-200. [PMID: 34041563 DOI: 10.1007/s00259-021-05408-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Accepted: 05/10/2021] [Indexed: 12/17/2022]
Abstract
PURPOSE Recent research in last years in substance use disorders (SUD) synthesized a proinflammatory hypothesis of SUD based on reported pieces of evidence of non-neuronal central immune signalling pathways modulated by drug of abuse and that contribute to their pharmacodynamic actions. Positron emission tomography has been shown to be a precious imaging technique to study in vivo neurochemical processes involved in SUD and to highlight the central immune signalling actions of drugs of abuse. METHODS In this review, we investigate the contribution of the central immune system, with a particular focus on translocator protein 18 kDa (TSPO) imaging, associated with a series of drugs involved in substance use disorders (SUD) specifically alcohol, opioids, tobacco, methamphetamine, cocaine, and cannabis. RESULTS The large majority of preclinical and clinical studies presented in this review converges towards SUD modulation of the neuroimmune responses and TSPO expression and speculated a pivotal positioning in the pathogenesis of SUD. However, some contradictions concerning the same drug or between preclinical and clinical studies make it difficult to draw a clear picture about the significance of glial state in SUD. DISCUSSION Significant disparities in clinical and biological characteristics are present between investigated populations among studies. Heterogeneity in genetic factors and other clinical co-morbidities, difficult to be reproduced in animal models, may affect findings. On the other hand, technical aspects including study designs, radioligand limitations, or PET imaging quantification methods could impact the study results and should be considered to explain discrepancies in outcomes. CONCLUSION The supposed neuroimmune component of SUD provides new therapeutic approaches in the prediction and treatment of SUD pointing to the central immune signalling.
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Affiliation(s)
- Claire Leroy
- Université Paris-Saclay, CEA, CNRS, Inserm, BioMaps, Service Hospitalier Frédéric Joliot, 4 place du général Leclerc, 91401, Orsay, France
| | - Wadad Saba
- Université Paris-Saclay, CEA, CNRS, Inserm, BioMaps, Service Hospitalier Frédéric Joliot, 4 place du général Leclerc, 91401, Orsay, France.
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70
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De Picker LJ, Haarman BCM. Applicability, potential and limitations of TSPO PET imaging as a clinical immunopsychiatry biomarker. Eur J Nucl Med Mol Imaging 2021; 49:164-173. [PMID: 33735406 DOI: 10.1007/s00259-021-05308-0] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Accepted: 03/08/2021] [Indexed: 02/08/2023]
Abstract
PURPOSE TSPO PET imaging may hold promise as a single-step diagnostic work-up for clinical immunopsychiatry. This review paper on the clinical applicability of TSPO PET for primary psychiatric disorders discusses if and why TSPO PET imaging might become the first clinical immunopsychiatry biomarker and the investment prerequisites and scientific advancements needed to accommodate this transition from bench to bedside. METHODS We conducted a systematic search of the literature to identify clinical studies of TSPO PET imaging in patients with primary psychiatric disorders. We included both original case-control studies as well as longitudinal cohort studies of patients with a primary psychiatric diagnosis. RESULTS Thirty-one original studies met our inclusion criteria. In the field of immunopsychiatry, TSPO PET has until now mostly been studied in schizophrenia and related psychotic disorders, and to a lesser extent in mood disorders and neurodevelopmental disorders. Quantitative TSPO PET appears most promising as a predictive biomarker for the transdiagnostic identification of subgroups or disease stages that could benefit from immunological treatments, or as a prognostic biomarker forecasting patients' illness course. Current scanning protocols are still too unreliable, impractical and invasive for clinical use in symptomatic psychiatric patients. CONCLUSION TSPO PET imaging in its present form does not yet offer a sufficiently attractive cost-benefit ratio to become a clinical immunopsychiatry biomarker. Its translation to psychiatric clinical practice will depend on the prioritising of longitudinal research and the establishment of a uniform protocol rendering clinically meaningful TSPO uptake quantification at the shortest possible scan duration without arterial cannulation.
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Affiliation(s)
- Livia J De Picker
- University Psychiatric Hospital Campus Duffel, Stationsstraat 22C, 2570, Duffel, Belgium.
- Collaborative Antwerp Psychiatric Research Institute, University of Antwerp, Wilrijkstraat 1, 2650, Edegem, Belgium.
| | - Benno C M Haarman
- Department of Psychiatry, University Medical Center Groningen, University of Groningen, Hanzeplein 1, 9700RA, Groningen, The Netherlands
- Rob Giel Research Center (RGOc), University Medical Center Groningen, University of Groningen, Hanzeplein 1, 9700RA, Groningen, The Netherlands
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Zinnhardt B, Roncaroli F, Foray C, Agushi E, Osrah B, Hugon G, Jacobs AH, Winkeler A. Imaging of the glioma microenvironment by TSPO PET. Eur J Nucl Med Mol Imaging 2021; 49:174-185. [PMID: 33721063 DOI: 10.1007/s00259-021-05276-5] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Accepted: 02/18/2021] [Indexed: 12/13/2022]
Abstract
Gliomas are highly dynamic and heterogeneous tumours of the central nervous system (CNS). They constitute the most common neoplasm of the CNS and the second most common cause of death from intracranial disease after stroke. The advances in detailing the genetic profile of paediatric and adult gliomas along with the progress in MRI and PET multimodal molecular imaging technologies have greatly improved prognostic stratification of patients with glioma and informed on treatment decisions. Amino acid PET has already gained broad clinical application in the study of gliomas. PET imaging targeting the translocator protein (TSPO) has recently been applied to decipher the heterogeneity and dynamics of the tumour microenvironment (TME) and its various cellular components especially in view of targeted immune therapies with the goal to delineate pro- and anti-glioma immune cell modulation. The current review provides a comprehensive overview on the historical developments of TSPO PET for gliomas and summarizes the most relevant experimental and clinical data with regard to the assessment and quantification of various cellular components with the TME of gliomas by in vivo TSPO PET imaging.
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Affiliation(s)
- Bastian Zinnhardt
- European Institute for Molecular Imaging (EIMI), Westfälische Wilhelms-University Münster (WWU), Münster, Germany
- Biomarkers and Translational Technologies, Roche Pharma Research and Early Development, Roche Innovation Center Basel, F. Hoffmann-La Roche Ltd., Basel, Switzerland
| | - Federico Roncaroli
- Geoffrey Jefferson Brain Research Centre, Manchester Academic Health Science Centre, Manchester, UK
- Division of Neuroscience and Experimental Psychology, School of Biological Sciences, Faculty of Brain and Mental Health, University of Manchester, Manchester, UK
| | - Claudia Foray
- European Institute for Molecular Imaging (EIMI), Westfälische Wilhelms-University Münster (WWU), Münster, Germany
| | - Erjon Agushi
- Geoffrey Jefferson Brain Research Centre, Manchester Academic Health Science Centre, Manchester, UK
- Division of Neuroscience and Experimental Psychology, School of Biological Sciences, Faculty of Brain and Mental Health, University of Manchester, Manchester, UK
| | - Bahiya Osrah
- Geoffrey Jefferson Brain Research Centre, Manchester Academic Health Science Centre, Manchester, UK
- Division of Neuroscience and Experimental Psychology, School of Biological Sciences, Faculty of Brain and Mental Health, University of Manchester, Manchester, UK
| | - Gaëlle Hugon
- Laboratoire d'Imagerie Biomédicale Multimodale (BioMaps), CEA, CNRS, Inserm, Université Paris-Saclay, Orsay, France
| | - Andreas H Jacobs
- European Institute for Molecular Imaging (EIMI), Westfälische Wilhelms-University Münster (WWU), Münster, Germany
- Department of Geriatrics and Neurology, Johanniter Hospital, Bonn, Germany
| | - Alexandra Winkeler
- Laboratoire d'Imagerie Biomédicale Multimodale (BioMaps), CEA, CNRS, Inserm, Université Paris-Saclay, Orsay, France.
- CEA, DRF, JOLIOT, SHFJ, Orsay, France.
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72
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Wimberley C, Buvat I, Boutin H. Imaging translocator protein expression with positron emission tomography. Eur J Nucl Med Mol Imaging 2021; 49:74-76. [PMID: 34729627 DOI: 10.1007/s00259-021-05601-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Affiliation(s)
- Catriona Wimberley
- Edinburgh Imaging QMRI, BioQuarter, University of Edinburgh, Edinburgh, EH16 4SB, UK.,Centre for Clinical Brain Sciences, Chancellor's Building, BioQuarter, University of Edinburgh, Edinburgh, EH14 4SB, UK
| | - Irene Buvat
- Institut Curie, Université PSL, Inserm, U1288 LITO, Orsay, France
| | - Hervé Boutin
- Division of Neuroscience and Experimental Psychology, School of Biological Sciences, Faculty of Brain and Mental Health, University of Manchester, Manchester, M13 9PL, UK. .,Wolfson Molecular Imaging Centre, University of Manchester, Manchester, M20 3LJ, UK. .,Geoffrey Jefferson Brain Research Centre, Manchester Academic Health Science Centre, Northern Care Alliance & University of Manchester, Manchester, UK.
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73
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de Fraga LS, Tassinari ID, Jantsch J, Guedes RP, Bambini-Junior V. 'A picture is worth a thousand words': The use of microscopy for imaging neuroinflammation. Clin Exp Immunol 2021; 206:325-345. [PMID: 34596237 DOI: 10.1111/cei.13669] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Revised: 09/21/2021] [Accepted: 09/22/2021] [Indexed: 01/08/2023] Open
Abstract
Since the first studies of the nervous system by the Nobel laureates Camillo Golgi and Santiago Ramon y Cajal using simple dyes and conventional light microscopes, microscopy has come a long way to the most recent techniques that make it possible to perform images in live cells and animals in health and disease. Many pathological conditions of the central nervous system have already been linked to inflammatory responses. In this scenario, several available markers and techniques can help imaging and unveil the neuroinflammatory process. Moreover, microscopy imaging techniques have become even more necessary to validate the large quantity of data generated in the era of 'omics'. This review aims to highlight how to assess neuroinflammation by using microscopy as a tool to provide specific details about the cell's architecture during neuroinflammatory conditions. First, we describe specific markers that have been used in light microscopy studies and that are widely applied to unravel and describe neuroinflammatory mechanisms in distinct conditions. Then, we discuss some important methodologies that facilitate the imaging of these markers, such as immunohistochemistry and immunofluorescence techniques. Emphasis will be given to studies using two-photon microscopy, an approach that revolutionized the real-time assessment of neuroinflammatory processes. Finally, some studies integrating omics with microscopy will be presented. The fusion of these techniques is developing, but the high amount of data generated from these applications will certainly improve comprehension of the molecular mechanisms involved in neuroinflammation.
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Affiliation(s)
- Luciano Stürmer de Fraga
- Programa de Pós-Graduação em Ciências Biológicas: Fisiologia, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil.,Centro de Pesquisa Experimental, Hospital de Clínicas de Porto Alegre (HCPA), Porto Alegre, Brazil
| | - Isadora D'Ávila Tassinari
- Programa de Pós-Graduação em Ciências Biológicas: Fisiologia, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil.,Centro de Pesquisa Experimental, Hospital de Clínicas de Porto Alegre (HCPA), Porto Alegre, Brazil
| | - Jeferson Jantsch
- Programa de Pós-Graduação em Biociências, Universidade Federal de Ciências da Saúde de Porto Alegre (UFCSPA), Porto Alegre, Brazil
| | - Renata Padilha Guedes
- Programa de Pós-Graduação em Biociências, Universidade Federal de Ciências da Saúde de Porto Alegre (UFCSPA), Porto Alegre, Brazil
| | - Victorio Bambini-Junior
- School of Pharmacy and Biomedical Sciences, University of Central Lancashire (UCLan), Preston, UK
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74
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Zhou R, Ji B, Kong Y, Qin L, Ren W, Guan Y, Ni R. PET Imaging of Neuroinflammation in Alzheimer's Disease. Front Immunol 2021; 12:739130. [PMID: 34603323 PMCID: PMC8481830 DOI: 10.3389/fimmu.2021.739130] [Citation(s) in RCA: 46] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2021] [Accepted: 08/27/2021] [Indexed: 12/15/2022] Open
Abstract
Neuroinflammation play an important role in Alzheimer's disease pathogenesis. Advances in molecular imaging using positron emission tomography have provided insights into the time course of neuroinflammation and its relation with Alzheimer's disease central pathologies in patients and in animal disease models. Recent single-cell sequencing and transcriptomics indicate dynamic disease-associated microglia and astrocyte profiles in Alzheimer's disease. Mitochondrial 18-kDa translocator protein is the most widely investigated target for neuroinflammation imaging. New generation of translocator protein tracers with improved performance have been developed and evaluated along with tau and amyloid imaging for assessing the disease progression in Alzheimer's disease continuum. Given that translocator protein is not exclusively expressed in glia, alternative targets are under rapid development, such as monoamine oxidase B, matrix metalloproteinases, colony-stimulating factor 1 receptor, imidazoline-2 binding sites, cyclooxygenase, cannabinoid-2 receptor, purinergic P2X7 receptor, P2Y12 receptor, the fractalkine receptor, triggering receptor expressed on myeloid cells 2, and receptor for advanced glycation end products. Promising targets should demonstrate a higher specificity for cellular locations with exclusive expression in microglia or astrocyte and activation status (pro- or anti-inflammatory) with highly specific ligand to enable in vivo brain imaging. In this review, we summarised recent advances in the development of neuroinflammation imaging tracers and provided an outlook for promising targets in the future.
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Affiliation(s)
- Rong Zhou
- Department of Nephrology, Yangpu Hospital, School of Medicine, Tongji University, Shanghai, China
| | - Bin Ji
- Department of Radiopharmacy and Molecular Imaging, School of Pharmacy, Fudan University, Shanghai, China
| | - Yanyan Kong
- Positron Emission Tomography (PET) Center, Huashan Hospital, Fudan University, Shanghai, China
| | - Limei Qin
- Inner Mongolia Baicaotang Qin Chinese Mongolia Hospital, Hohhot, China
| | - Wuwei Ren
- School of Information Science and Technology, Shanghaitech University, Shanghai, China
| | - Yihui Guan
- Positron Emission Tomography (PET) Center, Huashan Hospital, Fudan University, Shanghai, China
| | - Ruiqing Ni
- Institute for Regenerative Medicine, University of Zurich, Zurich, Switzerland
- Institute for Biomedical Engineering, University of Zurich & Eidgenössische Technische Hochschule Zürich (ETH Zurich), Zurich, Switzerland
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75
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Amor S, Nutma E, Marzin M, Puentes F. Imaging immunological processes from blood to brain in amyotrophic lateral sclerosis. Clin Exp Immunol 2021; 206:301-313. [PMID: 34510431 PMCID: PMC8561688 DOI: 10.1111/cei.13660] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Revised: 08/18/2021] [Accepted: 08/29/2021] [Indexed: 12/12/2022] Open
Abstract
Neuropathology studies of amyotrophic lateral sclerosis (ALS) and animal models of ALS reveal a strong association between aberrant protein accumulation and motor neurone damage, as well as activated microglia and astrocytes. While the role of neuroinflammation in the pathology of ALS is unclear, imaging studies of the central nervous system (CNS) support the idea that innate immune activation occurs early in disease in both humans and rodent models of ALS. In addition, emerging studies also reveal changes in monocytes, macrophages and lymphocytes in peripheral blood as well as at the neuromuscular junction. To more clearly understand the association of neuroinflammation (innate and adaptive) with disease progression, the use of biomarkers and imaging modalities allow monitoring of immune parameters in the disease process. Such approaches are important for patient stratification, selection and inclusion in clinical trials, as well as to provide readouts of response to therapy. Here, we discuss the different imaging modalities, e.g. magnetic resonance imaging, magnetic resonance spectroscopy and positron emission tomography as well as other approaches, including biomarkers of inflammation in ALS, that aid the understanding of the underlying immune mechanisms associated with motor neurone degeneration in ALS.
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Affiliation(s)
- Sandra Amor
- Department of Pathology, Amsterdam UMC Location VUmc, Amsterdam, the Netherlands.,Department of Neuroscience and Trauma, Blizard Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, London, UK
| | - Erik Nutma
- Department of Pathology, Amsterdam UMC Location VUmc, Amsterdam, the Netherlands
| | - Manuel Marzin
- Department of Pathology, Amsterdam UMC Location VUmc, Amsterdam, the Netherlands
| | - Fabiola Puentes
- Department of Neuroscience and Trauma, Blizard Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, London, UK
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76
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Beaino W, Janssen B, Vugts DJ, de Vries HE, Windhorst AD. Towards PET imaging of the dynamic phenotypes of microglia. Clin Exp Immunol 2021; 206:282-300. [PMID: 34331705 PMCID: PMC8561701 DOI: 10.1111/cei.13649] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Revised: 07/21/2021] [Accepted: 07/21/2021] [Indexed: 02/06/2023] Open
Abstract
There is increasing evidence showing the heterogeneity of microglia activation in neuroinflammatory and neurodegenerative diseases. It has been hypothesized that pro‐inflammatory microglia are detrimental and contribute to disease progression, while anti‐inflammatory microglia play a role in damage repair and remission. The development of therapeutics targeting the deleterious glial activity and modulating it into a regenerative phenotype relies heavily upon a clearer understanding of the microglia dynamics during disease progression and the ability to monitor therapeutic outcome in vivo. To that end, molecular imaging techniques are required to assess microglia dynamics and study their role in disease progression as well as to evaluate the outcome of therapeutic interventions. Positron emission tomography (PET) is such a molecular imaging technique, and provides unique capabilities for non‐invasive quantification of neuroinflammation and has the potential to discriminate between microglia phenotypes and define their role in the disease process. However, several obstacles limit the possibility for selective in vivo imaging of microglia phenotypes mainly related to the poor characterization of specific targets that distinguish the two ends of the microglia activation spectrum and lack of suitable tracers. PET tracers targeting translocator protein 18 kDa (TSPO) have been extensively explored, but despite the success in evaluating neuroinflammation they failed to discriminate between microglia activation statuses. In this review, we highlight the current knowledge on the microglia phenotypes in the major neuroinflammatory and neurodegenerative diseases. We also discuss the current and emerging PET imaging targets, the tracers and their potential in discriminating between the pro‐ and anti‐inflammatory microglia activation states.
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Affiliation(s)
- Wissam Beaino
- Department of Radiology and Nuclear Medicine, Tracer Center Amsterdam, Amsterdam UMC, Vrije Universiteit, Amsterdam, the Netherlands
| | - Bieneke Janssen
- Department of Radiology and Nuclear Medicine, Tracer Center Amsterdam, Amsterdam UMC, Vrije Universiteit, Amsterdam, the Netherlands
| | - Danielle J Vugts
- Department of Radiology and Nuclear Medicine, Tracer Center Amsterdam, Amsterdam UMC, Vrije Universiteit, Amsterdam, the Netherlands
| | - Helga E de Vries
- Department of Molecular Cell Biology and Immunology, MS Center Amsterdam, Amsterdam Neuroscience, Amsterdam UMC, Vrije Universiteit, Amsterdam, the Netherlands
| | - Albert D Windhorst
- Department of Radiology and Nuclear Medicine, Tracer Center Amsterdam, Amsterdam UMC, Vrije Universiteit, Amsterdam, the Netherlands
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77
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Tournier B, Ceyzériat K, Bouteldja FN, Millet P. Amyloid and Tau Induce Cell Death Independently of TSPO Polymerization and Density Changes. ACS OMEGA 2021; 6:18719-18727. [PMID: 34337211 PMCID: PMC8319921 DOI: 10.1021/acsomega.1c01678] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Accepted: 06/29/2021] [Indexed: 06/13/2023]
Abstract
Apoptosis-dependent cell death of astrocytes has been described in Alzheimer's disease and is linked to the presence of two markers of the pathology: the β-amyloid peptide (Aβ) and the hyperphosphorylated Tau protein. Astrocytes also show reactive states characterized by the overexpression of the 18 kDa translocator protein (TSPO). However, TSPO is also known, in other areas of research, to participate in cell proliferation and death. Regulation of its function by autopolymerization has been described, but its involvement in apoptosis remains unknown. The aim was to determine the effects of Aβ, Tau, and TSPO antagonists on proliferation/cell death and TSPO polymerization in the C6 astrocytic cell line. The dose-effect on cell death in response to Aβ and Tau was observed but without alterations of TSPO density and polymerization. In contrast, nanomolar doses of antagonists stimulated cell proliferation, although micromolar doses induced cell death with a reduction in TSPO density and an increase in the ratio between the 36 and the 72 kDa TSPO polymers. Therefore, an alteration in the density and polymerization of TSPO appears to be related to cell death induced by TSPO antagonisms. In contrast, Aβ- and Tau-induced death seems to be independent of TSPO alterations. In conclusion, even if its role in cell death and proliferation is demonstrated, TSPO seems to, in the context of Alzheimer's disease, rather represent a marker of the activity of astrocytes than of cell death.
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Affiliation(s)
- Benjamin
B. Tournier
- Department
of Psychiatry, University Hospitals of Geneva, 1205 Genève, Switzerland
- Department
of Psychiatry, University of Geneva, 1211 Genève, Switzerland
| | - Kelly Ceyzériat
- Department
of Psychiatry, University Hospitals of Geneva, 1205 Genève, Switzerland
- Department
of Psychiatry, University of Geneva, 1211 Genève, Switzerland
- Division
of Nuclear Medicine and Molecular Imaging, Diagnostic Department, University Hospitals of Geneva, 1205 Genève, Switzerland
- Division
of Radiation Oncology, Department of Oncology, University Hospitals of Geneva, 1205 Genève, Switzerland
| | - Farha N. Bouteldja
- Department
of Psychiatry, University Hospitals of Geneva, 1205 Genève, Switzerland
- Department
of Psychiatry, University of Geneva, 1211 Genève, Switzerland
| | - Philippe Millet
- Department
of Psychiatry, University Hospitals of Geneva, 1205 Genève, Switzerland
- Department
of Psychiatry, University of Geneva, 1211 Genève, Switzerland
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78
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Zhang H, Wang H, Gao F, Yang J, Xu Y, Fu Y, Cai M, Zhang X, Yang Q, Tong K, Hu Y, Chen H, Ma C, He W, Zhang J. TSPO deficiency accelerates amyloid pathology and neuroinflammation by impairing microglial phagocytosis. Neurobiol Aging 2021; 106:292-303. [PMID: 34340010 DOI: 10.1016/j.neurobiolaging.2021.06.020] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2019] [Revised: 06/08/2021] [Accepted: 06/25/2021] [Indexed: 12/25/2022]
Abstract
Increasing evidence has placed inflammation and immune dysfunction at the center of the pathogenesis of Alzheimer's disease (AD). The mitochondrial protein translocator protein (18 kDa) (TSPO) is highly upregulated in microglia and astrocytes in response to inflammatory stimulation. However, the biological action of TSPO in the pathogenesis of AD has not been determined to date. In this study, we showed that TSPO expression was upregulated in brain tissues from AD patients and AD model mice. APP/PS1 mice lacking TSPO generated significantly higher levels of Aβ1-40 and Aβ1-42 peptides and more Aβ plaques, as well as enhanced microglial activation, in the brain. TSPO-deficient microglia cultured in vitro showed a significant decrease in the ability to phagocytose Aβ peptides or latex beads and generated more proinflammatory cytokines (TNF-α and IL-1β) in response to Aβ peptides. Our findings suggest that TSPO has protective functions against neuroinflammation and Aβ pathogenesis in AD. TSPO may be a potential drug target for the development of drugs that have therapeutic or preventive effects in neuroinflammatory diseases.
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Affiliation(s)
- Han Zhang
- Department of Immunology, CAMS Key Laboratory for T Cell and Immunotherapy, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and School of Basic Medicine, Peking Union Medical College, State Key Laboratory of Medical Molecular Biology, Beijing, China
| | - Huaishan Wang
- Department of Immunology, CAMS Key Laboratory for T Cell and Immunotherapy, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and School of Basic Medicine, Peking Union Medical College, State Key Laboratory of Medical Molecular Biology, Beijing, China
| | - Fei Gao
- Department of Immunology, CAMS Key Laboratory for T Cell and Immunotherapy, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and School of Basic Medicine, Peking Union Medical College, State Key Laboratory of Medical Molecular Biology, Beijing, China
| | - Jia Yang
- Department of Immunology, CAMS Key Laboratory for T Cell and Immunotherapy, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and School of Basic Medicine, Peking Union Medical College, State Key Laboratory of Medical Molecular Biology, Beijing, China
| | - Yi Xu
- Department of Immunology, CAMS Key Laboratory for T Cell and Immunotherapy, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and School of Basic Medicine, Peking Union Medical College, State Key Laboratory of Medical Molecular Biology, Beijing, China
| | - Yi Fu
- Department of Immunology, CAMS Key Laboratory for T Cell and Immunotherapy, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and School of Basic Medicine, Peking Union Medical College, State Key Laboratory of Medical Molecular Biology, Beijing, China
| | - Menghua Cai
- Department of Immunology, CAMS Key Laboratory for T Cell and Immunotherapy, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and School of Basic Medicine, Peking Union Medical College, State Key Laboratory of Medical Molecular Biology, Beijing, China
| | - Xue Zhang
- Department of Immunology, CAMS Key Laboratory for T Cell and Immunotherapy, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and School of Basic Medicine, Peking Union Medical College, State Key Laboratory of Medical Molecular Biology, Beijing, China
| | - Qi Yang
- Department of Immunology, CAMS Key Laboratory for T Cell and Immunotherapy, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and School of Basic Medicine, Peking Union Medical College, State Key Laboratory of Medical Molecular Biology, Beijing, China
| | - Kexin Tong
- Department of Immunology, CAMS Key Laboratory for T Cell and Immunotherapy, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and School of Basic Medicine, Peking Union Medical College, State Key Laboratory of Medical Molecular Biology, Beijing, China
| | - Yu Hu
- Department of Immunology, CAMS Key Laboratory for T Cell and Immunotherapy, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and School of Basic Medicine, Peking Union Medical College, State Key Laboratory of Medical Molecular Biology, Beijing, China
| | - Hui Chen
- Department of Immunology, CAMS Key Laboratory for T Cell and Immunotherapy, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and School of Basic Medicine, Peking Union Medical College, State Key Laboratory of Medical Molecular Biology, Beijing, China
| | - Chao Ma
- Department of Human Anatomy, Histology and Embryology, Institute of Basic Medical Sciences, Neuroscience Center, Chinese Academy of Medical Sciences, School of Basic Medicine, Peking Union Medical College, Beijing, China
| | - Wei He
- Department of Immunology, CAMS Key Laboratory for T Cell and Immunotherapy, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and School of Basic Medicine, Peking Union Medical College, State Key Laboratory of Medical Molecular Biology, Beijing, China.
| | - Jianmin Zhang
- Department of Immunology, CAMS Key Laboratory for T Cell and Immunotherapy, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and School of Basic Medicine, Peking Union Medical College, State Key Laboratory of Medical Molecular Biology, Beijing, China.
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