51
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Koganti PP, Selvaraj V. Lack of adrenal TSPO/PBR expression in hamsters reinforces correlation to triglyceride metabolism. J Endocrinol 2020; 247:1-10. [PMID: 32698131 PMCID: PMC8011561 DOI: 10.1530/joe-20-0189] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Accepted: 07/13/2020] [Indexed: 11/08/2022]
Abstract
Despite being a highly conserved protein, the precise role of the mitochondrial translocator protein (TSPO), previously known as the peripheral benzodiazepine receptor (PBR), remains elusive. The void created by studies that overturned a presumptive model that described TSPO/PBR as a mitochondrial cholesterol transporter for steroidogenesis has been filled with evidence that it can affect mitochondrial metabolic functions across different model systems. We previously reported that TSPO/PBR deficient steroidogenic cells upregulate mitochondrial fatty acid oxidation and presented a strong positive correlation between TSPO/PBR expression and tissues active in triglyceride metabolism or lipid storage. Nevertheless, the highlighting of inconsistencies in prior work has provoked reprisals that threaten to stifle progress. One frequent factoid presented as being supportive of a cholesterol import function is that there are no steroid-synthesizing cell types without high TSPO/PBR expression. In this study, we examine the hamster adrenal gland that is devoid of lipid droplets in the cortex and largely relies on de novo cholesterol biosynthesis and uptake for steroidogenesis. We find that Tspo expression in the hamster adrenal is imperceptible compared to the mouse. This observation is consistent with a substantially low expression of Cpt1a in the hamster adrenal, indicating minimal mitochondrial fatty acid oxidation capacity compared to the mouse. These findings provide further reinforcement that the much sought-after mechanism of TSPO/PBR function remains correlated with the extent of cellular triglyceride metabolism. Thus, TSPO/PBR could have a homeostatic function relevant only to steroidogenic systems that manage triglycerides associated with lipid droplets.
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Affiliation(s)
- Prasanthi P. Koganti
- Department of Animal Science, College of Agriculture and Life Sciences, Cornell University, Ithaca, NY 14853
| | - Vimal Selvaraj
- Department of Animal Science, College of Agriculture and Life Sciences, Cornell University, Ithaca, NY 14853
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52
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Sharma A, Liaw K, Sharma R, Thomas AG, Slusher BS, Kannan S, Kannan RM. Targeting Mitochondria in Tumor-Associated Macrophages using a Dendrimer-Conjugated TSPO Ligand that Stimulates Antitumor Signaling in Glioblastoma. Biomacromolecules 2020; 21:3909-3922. [PMID: 32786523 PMCID: PMC8022998 DOI: 10.1021/acs.biomac.0c01033] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Mitochondria mediate critical cellular processes, including proliferation, apoptosis, and immune responses; as such, their dysfunction is pathogenic in many neurodegenerative disorders and cancers. In glioblastoma, targeted delivery of mitochondria-focused anticancer therapies has failed to translate into clinical success due to the nonspecific cellular localization, heterogeneity of receptor expression across patients, poor transport across biological barriers to reach the brain, tumor, and mitochondria, and systemic side effects. Strategies that can overcome brain and solid tumor barriers and selectively target mitochondria within specific cell types may lead to improvements in glioblastoma treatment. Developments in dendrimer-mediated nanomedicines have shown promise targeting tumor-associated macrophages (TAMs) in glioblastoma, following systemic administration. Here, we present a novel dendrimer conjugated to the translocator protein (18 kDa) (TSPO) ligand 5,7-dimethylpyrazolo[1,5-α]pyrimidin-3-ylacetamide (DPA). We developed a clickable DPA for conjugation on the dendrimer surface and demonstrated in vitro that the dendrimer-DPA conjugate (D-DPA) significantly increases dendrimer colocalization with mitochondria. Compared to free TSPO ligand PK11195, D-DPA stimulates greater antitumor immune signaling. In vivo, we show that D-DPA targets mitochondria specifically within TAMs following systemic administration. Our results demonstrate that dendrimers can achieve TAM-specific targeting in glioblastoma and can be further modified to target specific intracellular compartments for organelle-specific drug delivery.
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53
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Downer OM, Marcus RE, Zürcher NR, Hooker JM. Tracing the History of the Human Translocator Protein to Recent Neurodegenerative and Psychiatric Imaging. ACS Chem Neurosci 2020; 11:2192-2200. [PMID: 32662626 DOI: 10.1021/acschemneuro.0c00362] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
The human 18 kDa translocator protein (TSPO) has been widely used as a measure of glial activation in health and disease. With the continuous progress of radiotracers with increased affinity and selectivity, associations between TSPO expression, disease severity, and progression have been examined, particularly in neurodegenerative disorders such as multiple sclerosis (MS), Parkinson's disease (PD), and amyotrophic lateral sclerosis (ALS). However, findings in psychiatric disorders have prompted reassessment of the interpretation of regional TSPO expression differences in the brain, specifically with respect to potential neuroinflammatory components. This "mini" Review aims to guide readers through the complexity of TSPO imaging research by identifying the successes, challenges, and promising new directions of the field. We will provide a brief history of how TSPO imaging has evolved over the last three decades and present lessons learned in the context of neurodegenerative and psychiatric disorders.
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Affiliation(s)
- Olivia M. Downer
- Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, Massachusetts 02129, United States
| | - Rachel E.G. Marcus
- Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, Massachusetts 02129, United States
| | - Nicole R. Zürcher
- Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, Massachusetts 02129, United States
- Harvard Medical School, Charlestown, Massachusetts 02129, United States
| | - Jacob M. Hooker
- Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, Massachusetts 02129, United States
- Harvard Medical School, Charlestown, Massachusetts 02129, United States
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54
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Rao R, Diharce J, Dugué B, Ostuni MA, Cadet F, Etchebest C. Versatile Dimerisation Process of Translocator Protein (TSPO) Revealed by an Extensive Sampling Based on a Coarse-Grained Dynamics Study. J Chem Inf Model 2020; 60:3944-3957. [DOI: 10.1021/acs.jcim.0c00246] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Rajas Rao
- Université de Paris, Biologie Intégrée du Globule Rouge, UMR_S1134, BIGR, INSERM, F-75015, Paris, France
- Laboratoire d’Excellence GR-Ex, 75015 Paris, France
- Université de la Réunion, Biologie Intégrée du Globule Rouge, UMR_S1134, BIGR, Faculté des Sciences & Technologies Saint-Denis, F-97715 St. Denis, France
| | - Julien Diharce
- Université de Paris, Biologie Intégrée du Globule Rouge, UMR_S1134, BIGR, INSERM, F-75015, Paris, France
- Laboratoire d’Excellence GR-Ex, 75015 Paris, France
- Université de la Réunion, Biologie Intégrée du Globule Rouge, UMR_S1134, BIGR, Faculté des Sciences & Technologies Saint-Denis, F-97715 St. Denis, France
| | - Bérénice Dugué
- Université de Paris, Biologie Intégrée du Globule Rouge, UMR_S1134, BIGR, INSERM, F-75015, Paris, France
- Laboratoire d’Excellence GR-Ex, 75015 Paris, France
- Université de la Réunion, Biologie Intégrée du Globule Rouge, UMR_S1134, BIGR, Faculté des Sciences & Technologies Saint-Denis, F-97715 St. Denis, France
| | - Mariano A. Ostuni
- Université de Paris, Biologie Intégrée du Globule Rouge, UMR_S1134, BIGR, INSERM, F-75015, Paris, France
- Laboratoire d’Excellence GR-Ex, 75015 Paris, France
| | - Frédéric Cadet
- Université de Paris, Biologie Intégrée du Globule Rouge, UMR_S1134, BIGR, INSERM, F-75015, Paris, France
- Laboratoire d’Excellence GR-Ex, 75015 Paris, France
- Université de la Réunion, Biologie Intégrée du Globule Rouge, UMR_S1134, BIGR, Faculté des Sciences & Technologies Saint-Denis, F-97715 St. Denis, France
- PEACCEL, Artificial Intelligence Department, 6 Square Albin Cachot, Box 42, 75013 Paris, France
| | - Catherine Etchebest
- Université de Paris, Biologie Intégrée du Globule Rouge, UMR_S1134, BIGR, INSERM, F-75015, Paris, France
- Laboratoire d’Excellence GR-Ex, 75015 Paris, France
- Université de la Réunion, Biologie Intégrée du Globule Rouge, UMR_S1134, BIGR, Faculté des Sciences & Technologies Saint-Denis, F-97715 St. Denis, France
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55
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Laurell GL, Plavén-Sigray P, Jucaite A, Varrone A, Cosgrove KP, Svarer C, Knudsen GM, Ogden RT, Zanderigo F, Cervenka S, Hillmer AT, Schain M. Nondisplaceable Binding Is a Potential Confounding Factor in 11C-PBR28 Translocator Protein PET Studies. J Nucl Med 2020; 62:412-417. [PMID: 32680926 DOI: 10.2967/jnumed.120.243717] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2020] [Accepted: 06/23/2020] [Indexed: 01/08/2023] Open
Abstract
The PET ligand 11C-PBR28 (N-((2-(methoxy-11C)-phenyl)methyl)-N-(6-phenoxy-3-pyridinyl)acetamide) binds to the 18-kDa translocator protein (TSPO), a biomarker of glia. In clinical studies of TSPO, the ligand total distribution volume, VT, is frequently the reported outcome measure. Since VT is the sum of the ligand-specific distribution volume (VS) and the nondisplaceable-binding distribution volume (VND), differences in VND across subjects and groups will have an impact on VT Methods: Here, we used a recently developed method for simultaneous estimation of VND (SIME) to disentangle contributions from VND and VS Data from 4 previously published 11C-PBR28 PET studies were included: before and after a lipopolysaccharide challenge (8 subjects), in alcohol use disorder (14 patients, 15 controls), in first-episode psychosis (16 patients, 16 controls), and in Parkinson disease (16 patients, 16 controls). In each dataset, regional VT estimates were obtained with a standard 2-tissue-compartment model, and brain-wide VND was estimated with SIME. VS was then calculated as VT - VND VND and VS were then compared across groups, within each dataset. Results: A lower VND was found for individuals with alcohol-use disorder (34%, P = 0.00084) and Parkinson disease (34%, P = 0.0032) than in their corresponding controls. We found no difference in VND between first-episode psychosis patients and their controls, and the administration of lipopolysaccharide did not change VND Conclusion: Our findings suggest that in TSPO PET studies, nondisplaceable binding can differ between patient groups and conditions and should therefore be considered.
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Affiliation(s)
- Gjertrud L Laurell
- Neurobiology Research Unit, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark
| | - Pontus Plavén-Sigray
- Neurobiology Research Unit, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark.,Centre for Psychiatry Research, Department of Clinical Neuroscience, Karolinska Institutet, and Stockholm Health Care Services, Region Stockholm, Stockholm, Sweden
| | - Aurelija Jucaite
- Centre for Psychiatry Research, Department of Clinical Neuroscience, Karolinska Institutet, and Stockholm Health Care Services, Region Stockholm, Stockholm, Sweden.,PET Science Centre, Precision Medicine and Genomics, R&D, AstraZeneca, Stockholm, Sweden
| | - Andrea Varrone
- Centre for Psychiatry Research, Department of Clinical Neuroscience, Karolinska Institutet, and Stockholm Health Care Services, Region Stockholm, Stockholm, Sweden
| | - Kelly P Cosgrove
- PET Center, Department of Radiology and Biomedical Imaging, Yale University, New Haven, Connecticut.,Department of Psychiatry, Yale University, New Haven, Connecticut
| | - Claus Svarer
- Neurobiology Research Unit, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark
| | - Gitte M Knudsen
- Neurobiology Research Unit, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark.,Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | | | - R Todd Ogden
- Department of Biostatistics, Columbia University, New York, New York.,Molecular Imaging and Neuropathology Area, New York State Psychiatric Institute, New York, New York
| | - Francesca Zanderigo
- Department of Biostatistics, Columbia University, New York, New York.,Department of Psychiatry, Columbia University College of Physicians and Surgeons, New York, New York; and
| | - Simon Cervenka
- Centre for Psychiatry Research, Department of Clinical Neuroscience, Karolinska Institutet, and Stockholm Health Care Services, Region Stockholm, Stockholm, Sweden
| | - Ansel T Hillmer
- PET Center, Department of Radiology and Biomedical Imaging, Yale University, New Haven, Connecticut.,Department of Psychiatry, Yale University, New Haven, Connecticut.,Department of Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, Connecticut
| | - Martin Schain
- Neurobiology Research Unit, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark
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56
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Aires ID, Ribeiro-Rodrigues T, Boia R, Catarino S, Girão H, Ambrósio AF, Santiago AR. Exosomes derived from microglia exposed to elevated pressure amplify the neuroinflammatory response in retinal cells. Glia 2020; 68:2705-2724. [PMID: 32645245 DOI: 10.1002/glia.23880] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2020] [Revised: 06/09/2020] [Accepted: 06/10/2020] [Indexed: 12/13/2022]
Abstract
Glaucoma is a degenerative disease that causes irreversible loss of vision and is characterized by retinal ganglion cell (RGC) loss. Others and we have demonstrated that chronic neuroinflammation mediated by reactive microglial cells plays a role in glaucomatous pathology. Exosomes are extracellular vesicles released by most cells, including microglia, that mediate intercellular communication. The role of microglial exosomes in glaucomatous degeneration remains unknown. Taking the prominent role of microglial exosomes in brain neurodegenerative diseases, we studied the contribution of microglial-derived exosomes to the inflammatory response in experimental glaucoma. Microglial cells were exposed to elevated hydrostatic pressure (EHP), to mimic elevated intraocular pressure, the main risk factor for glaucoma. Naïve microglia (BV-2 cells or retinal microglia) were exposed to exosomes derived from BV-2 cells under EHP conditions (BV-Exo-EHP) or cultured in control pressure (BV-Exo-Control). We found that BV-Exo-EHP increased the production of pro-inflammatory cytokines, promoted retinal microglia motility, phagocytic efficiency, and proliferation. Furthermore, the incubation of primary retinal neural cell cultures with BV-Exo-EHP increased cell death and the production of reactive oxygen species. Exosomes derived from retinal microglia (MG-Exo-Control or MG-Exo-EHP) were injected in the vitreous of C57BL/6J mice. MG-Exo-EHP sustained activation of retinal microglia, mediated cell death, and impacted RGC number. Herein, we show that exosomes derived from retinal microglia have an autocrine function and propagate the inflammatory signal in conditions of elevated pressure, contributing to retinal degeneration in glaucomatous conditions.
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Affiliation(s)
- Inês Dinis Aires
- Coimbra Institute for Clinical and Biomedical Research (iCBR), Faculty of Medicine, University of Coimbra, Coimbra, Portugal.,Center for Innovative Biomedicine and Biotechnology (CIBB), University of Coimbra, Coimbra, Portugal.,Clinical Academic Center of Coimbra (CACC), Coimbra, Portugal
| | - Teresa Ribeiro-Rodrigues
- Coimbra Institute for Clinical and Biomedical Research (iCBR), Faculty of Medicine, University of Coimbra, Coimbra, Portugal.,Center for Innovative Biomedicine and Biotechnology (CIBB), University of Coimbra, Coimbra, Portugal.,Clinical Academic Center of Coimbra (CACC), Coimbra, Portugal
| | - Raquel Boia
- Coimbra Institute for Clinical and Biomedical Research (iCBR), Faculty of Medicine, University of Coimbra, Coimbra, Portugal.,Center for Innovative Biomedicine and Biotechnology (CIBB), University of Coimbra, Coimbra, Portugal.,Clinical Academic Center of Coimbra (CACC), Coimbra, Portugal
| | - Steve Catarino
- Coimbra Institute for Clinical and Biomedical Research (iCBR), Faculty of Medicine, University of Coimbra, Coimbra, Portugal.,Center for Innovative Biomedicine and Biotechnology (CIBB), University of Coimbra, Coimbra, Portugal.,Clinical Academic Center of Coimbra (CACC), Coimbra, Portugal
| | - Henrique Girão
- Coimbra Institute for Clinical and Biomedical Research (iCBR), Faculty of Medicine, University of Coimbra, Coimbra, Portugal.,Center for Innovative Biomedicine and Biotechnology (CIBB), University of Coimbra, Coimbra, Portugal.,Clinical Academic Center of Coimbra (CACC), Coimbra, Portugal
| | - António Francisco Ambrósio
- Coimbra Institute for Clinical and Biomedical Research (iCBR), Faculty of Medicine, University of Coimbra, Coimbra, Portugal.,Center for Innovative Biomedicine and Biotechnology (CIBB), University of Coimbra, Coimbra, Portugal.,Clinical Academic Center of Coimbra (CACC), Coimbra, Portugal.,Association for Innovation and Biomedical Research on Light and Image (AIBILI), Coimbra, Portugal
| | - Ana Raquel Santiago
- Coimbra Institute for Clinical and Biomedical Research (iCBR), Faculty of Medicine, University of Coimbra, Coimbra, Portugal.,Center for Innovative Biomedicine and Biotechnology (CIBB), University of Coimbra, Coimbra, Portugal.,Clinical Academic Center of Coimbra (CACC), Coimbra, Portugal.,Association for Innovation and Biomedical Research on Light and Image (AIBILI), Coimbra, Portugal
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57
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Banati RB, Wilcox P, Xu R, Yin G, Si E, Son ET, Shimizu M, Holsinger RMD, Parmar A, Zahra D, Arthur A, Middleton RJ, Liu GJ, Charil A, Graeber MB. Selective, high-contrast detection of syngeneic glioblastoma in vivo. Sci Rep 2020; 10:9968. [PMID: 32561881 PMCID: PMC7305160 DOI: 10.1038/s41598-020-67036-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2019] [Accepted: 05/19/2020] [Indexed: 01/14/2023] Open
Abstract
Glioblastoma is a highly malignant, largely therapy-resistant brain tumour. Deep infiltration of brain tissue by neoplastic cells represents the key problem of diffuse glioma. Much current research focuses on the molecular makeup of the visible tumour mass rather than the cellular interactions in the surrounding brain tissue infiltrated by the invasive glioma cells that cause the tumour’s ultimately lethal outcome. Diagnostic neuroimaging that enables the direct in vivo observation of the tumour infiltration zone and the local host tissue responses at a preclinical stage are important for the development of more effective glioma treatments. Here, we report an animal model that allows high-contrast imaging of wild-type glioma cells by positron emission tomography (PET) using [18 F]PBR111, a selective radioligand for the mitochondrial 18 kDa Translocator Protein (TSPO), in the Tspo−/− mouse strain (C57BL/6-Tspotm1GuMu(GuwiyangWurra)). The high selectivity of [18 F]PBR111 for the TSPO combined with the exclusive expression of TSPO in glioma cells infiltrating into null-background host tissue free of any TSPO expression, makes it possible, for the first time, to unequivocally and with uniquely high biological contrast identify peri-tumoral glioma cell invasion at preclinical stages in vivo. Comparison of the in vivo imaging signal from wild-type glioma cells in a null background with the signal in a wild-type host tissue, where the tumour induces the expected TSPO expression in the host’s glial cells, illustrates the substantial extent of the peritumoral host response to the growing tumour. The syngeneic tumour (TSPO+/+) in null background (TSPO−/−) model is thus well suited to study the interaction of the tumour front with the peri-tumoral tissue, and the experimental evaluation of new therapeutic approaches targeting the invasive behaviour of glioblastoma.
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Affiliation(s)
- Richard B Banati
- Australian Nuclear Science and Technology Organization, Locked Bag 2001, Kirrawee DC, NSW, 2232, Australia. .,Medical Imaging, Faculty of Medicine and Health, The University of Sydney, 94 Mallett Street, Camperdown, NSW, 2050, Australia.
| | - Paul Wilcox
- Brain Tumour Research, Brain and Mind Centre, Faculty of Medicine and Health, The University of Sydney, 94 Mallett Street, Camperdown, NSW, 2050, Australia
| | - Ran Xu
- Brain Tumour Research, Brain and Mind Centre, Faculty of Medicine and Health, The University of Sydney, 94 Mallett Street, Camperdown, NSW, 2050, Australia
| | - Grace Yin
- Brain Tumour Research, Brain and Mind Centre, Faculty of Medicine and Health, The University of Sydney, 94 Mallett Street, Camperdown, NSW, 2050, Australia
| | - Emily Si
- Brain Tumour Research, Brain and Mind Centre, Faculty of Medicine and Health, The University of Sydney, 94 Mallett Street, Camperdown, NSW, 2050, Australia
| | - Eric Taeyoung Son
- Brain Tumour Research, Brain and Mind Centre, Faculty of Medicine and Health, The University of Sydney, 94 Mallett Street, Camperdown, NSW, 2050, Australia
| | - Mauricio Shimizu
- Brain Tumour Research, Brain and Mind Centre, Faculty of Medicine and Health, The University of Sydney, 94 Mallett Street, Camperdown, NSW, 2050, Australia
| | - R M Damian Holsinger
- Molecular Neuroscience, Brain and Mind Centre, Faculty of Medicine and Health, The University of Sydney, 94 Mallett Street, Camperdown, NSW, 2050, Australia
| | - Arvind Parmar
- Australian Nuclear Science and Technology Organization, Locked Bag 2001, Kirrawee DC, NSW, 2232, Australia
| | - David Zahra
- Australian Nuclear Science and Technology Organization, Locked Bag 2001, Kirrawee DC, NSW, 2232, Australia
| | - Andrew Arthur
- Australian Nuclear Science and Technology Organization, Locked Bag 2001, Kirrawee DC, NSW, 2232, Australia
| | - Ryan J Middleton
- Australian Nuclear Science and Technology Organization, Locked Bag 2001, Kirrawee DC, NSW, 2232, Australia
| | - Guo-Jun Liu
- Australian Nuclear Science and Technology Organization, Locked Bag 2001, Kirrawee DC, NSW, 2232, Australia.,Medical Imaging, Faculty of Medicine and Health, The University of Sydney, 94 Mallett Street, Camperdown, NSW, 2050, Australia
| | - Arnaud Charil
- Australian Nuclear Science and Technology Organization, Locked Bag 2001, Kirrawee DC, NSW, 2232, Australia
| | - Manuel B Graeber
- Brain Tumour Research, Brain and Mind Centre, Faculty of Medicine and Health, The University of Sydney, 94 Mallett Street, Camperdown, NSW, 2050, Australia.
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58
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Hosomi S, Ohnishi M, Ogura H, Shimazu T. Traumatic brain injury-related inflammatory projection: beyond local inflammatory responses. Acute Med Surg 2020; 7:e520. [PMID: 32514363 PMCID: PMC7272327 DOI: 10.1002/ams2.520] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2020] [Revised: 04/24/2020] [Accepted: 04/30/2020] [Indexed: 12/27/2022] Open
Abstract
Acute neuroinflammation induced by microglial activation is key for repair and recovery after traumatic brain injury (TBI) and could be necessary for the clearance of harmful substances, such as cell debris. However, recent clinical and preclinical data have shown that TBI causes chronic neuroinflammation, lasting many years in some cases, and leading to chronic neurodegeneration, dementia, and encephalopathy. To evaluate neuroinflammation in vivo, positron‐emission tomography has been used to target translocator protein, which is upregulated in activated glial cells. Such studies have suggested that remote neuroinflammation induced by regional microglia persists even after reduced inflammatory responses at the injury site. Furthermore, unregulated inflammatory responses are associated with neurodegeneration. Therefore, elucidation of the role of neuroinflammation in TBI pathology is essential for developing new therapeutic targets for TBI. Treatment of associated progressive disorders requires a deeper understanding of how inflammatory responses to injury are triggered, sustained, and resolved and how they impact neuronal function. In this review, we provide a general overview of the dynamics of immune responses to TBI, from acute to chronic neuroinflammation. We discuss the clinical significance of remote ongoing neuroinflammation, termed “brain injury‐related inflammatory projection”. We also highlight positron‐emission tomography imaging as a promising approach needing further development to facilitate an understanding of post‐TBI inflammatory and neurodegenerative processes and to monitor the clinical effects of corresponding new therapeutic strategies.
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Affiliation(s)
- Sanae Hosomi
- Department of Traumatology and Acute Critical Medicine Osaka University Graduate School of Medicine Osaka Japan
| | - Mitsuo Ohnishi
- Department of Acute Medicine and Critical Care Medical Center Osaka National Hospital National Hospital Organization Osaka Japan
| | - Hiroshi Ogura
- Department of Traumatology and Acute Critical Medicine Osaka University Graduate School of Medicine Osaka Japan
| | - Takeshi Shimazu
- Department of Traumatology and Acute Critical Medicine Osaka University Graduate School of Medicine Osaka Japan
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59
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Taliani S, Da Settimo F, Martini C, Laneri S, Novellino E, Greco G. Exploiting the Indole Scaffold to Design Compounds Binding to Different Pharmacological Targets. Molecules 2020; 25:molecules25102331. [PMID: 32429433 PMCID: PMC7287756 DOI: 10.3390/molecules25102331] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2020] [Revised: 05/14/2020] [Accepted: 05/15/2020] [Indexed: 12/14/2022] Open
Abstract
Several indole derivatives have been disclosed by our research groups that have been collaborating for nearly 25 years. The results of our investigations led to a variety of molecules binding selectively to different pharmacological targets, specifically the type A γ-aminobutyric acid (GABAA) chloride channel, the translocator protein (TSPO), the murine double minute 2 (MDM2) protein, the A2B adenosine receptor (A2B AR) and the Kelch-like ECH-associated protein 1 (Keap1). Herein, we describe how these works were conceived and carried out thanks to the versatility of indole nucleus to be exploited in the design and synthesis of drug-like molecules.
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Affiliation(s)
- Sabrina Taliani
- Department of Pharmacy, University of Pisa, Via Bonanno Pisano, 6, 56126 Pisa, Italy; (F.D.S.); (C.M.)
- Correspondence: (S.T.); (G.G.); Tel.: +39-050-2219547 (S.T.); +39-081-678645 (G.G.)
| | - Federico Da Settimo
- Department of Pharmacy, University of Pisa, Via Bonanno Pisano, 6, 56126 Pisa, Italy; (F.D.S.); (C.M.)
| | - Claudia Martini
- Department of Pharmacy, University of Pisa, Via Bonanno Pisano, 6, 56126 Pisa, Italy; (F.D.S.); (C.M.)
| | - Sonia Laneri
- Department of Pharmacy, University of Naples “Federico II”, Via D. Montesano, 49, 80131 Naples, Italy; (S.L.); (E.N.)
| | - Ettore Novellino
- Department of Pharmacy, University of Naples “Federico II”, Via D. Montesano, 49, 80131 Naples, Italy; (S.L.); (E.N.)
| | - Giovanni Greco
- Department of Pharmacy, University of Naples “Federico II”, Via D. Montesano, 49, 80131 Naples, Italy; (S.L.); (E.N.)
- Correspondence: (S.T.); (G.G.); Tel.: +39-050-2219547 (S.T.); +39-081-678645 (G.G.)
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60
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Bertrand SJ, Zhang Z, Patel R, O'Ferrell C, Punjabi NM, Kudchadkar SR, Kannan S. Transient neonatal sleep fragmentation results in long-term neuroinflammation and cognitive impairment in a rabbit model. Exp Neurol 2020; 327:113212. [PMID: 31987835 DOI: 10.1016/j.expneurol.2020.113212] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2019] [Revised: 01/18/2020] [Accepted: 01/24/2020] [Indexed: 12/29/2022]
Abstract
Sleep fragmentation is an increase in sleep-wake transitions without an overall decrease in total sleep time. Sleep fragmentation is well documented during acute and chronic hospitalization and can result in delirium and memory problems in children. Sleep fragmentation is also often noted in neurodevelopmental disorders. However, it is unclear how sleep fragmentation independent of disease affects brain development and function. We hypothesized that acute sleep fragmentation during the neonatal period in otherwise healthy animals would result in neuroinflammation and would be associated with abnormalities in cognitive development. The orbital shaker method was used to fragment sleep for 72 h in postnatal day 3 New Zealand white rabbit kits (fragmentation group). To control for maternal separation, the sham group was separated from the dam and maintained in the same conditions without undergoing sleep fragmentation. A naïve control group remained with the dam. Kits underwent behavioral testing with novel object recognition and spontaneous alternation T-maze tests at 2-3 weeks post-fragmentation and were sacrificed 3-50 days after fragmentation. Sleep fragmentation resulted in acute and chronic changes in microglial morphology in the hippocampus and cortex, and regional differences in mRNA expression of pro- and anti-inflammatory cytokines at 3, 7 and 50 days post-fragmentation. Impaired novel object recognition and a longer latency in T-maze task completion were noted in the fragmented kits. This was in spite of normalization of sleep architecture noted at 2 months of age in these kits. The results indicate that transient neonatal sleep fragmentation results in short-term and long-term immune alterations in the brain, along with diminished performance in cognitive tasks long-term.
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Affiliation(s)
- Sarah J Bertrand
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, United States of America
| | - Zhi Zhang
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, United States of America
| | - Ruchit Patel
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, United States of America
| | - Caroline O'Ferrell
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, United States of America
| | - Naresh M Punjabi
- Department of Medicine, Division of Pulmonary and Critical Care Medicine, Johns Hopkins University School of Medicine, United States of America
| | - Sapna R Kudchadkar
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, United States of America; Department of Pediatrics, Johns Hopkins University School of Medicine, United States of America; Department of Physical Medicine and Rehabilitation, Johns Hopkins University School of Medicine, United States of America.
| | - Sujatha Kannan
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, United States of America.
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61
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Tong J, Williams B, Rusjan PM, Mizrahi R, Lacapère JJ, McCluskey T, Furukawa Y, Guttman M, Ang LC, Boileau I, Meyer JH, Kish SJ. Concentration, distribution, and influence of aging on the 18 kDa translocator protein in human brain: Implications for brain imaging studies. J Cereb Blood Flow Metab 2020; 40:1061-1076. [PMID: 31220997 PMCID: PMC7181090 DOI: 10.1177/0271678x19858003] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Positron emission tomography (PET) imaging of the translocator protein (TSPO) is widely used as a biomarker of microglial activation. However, TSPO protein concentration in human brain has not been optimally quantified nor has its regional distribution been compared to TSPO binding. We determined TSPO protein concentration, change with age, and regional distribution by quantitative immunoblotting in autopsied human brain. Brain TSPO protein concentration (>0.1 ng/µg protein) was higher than those reported by in vitro binding assays by at least 2 to 70 fold. TSPO protein distributed widely in both gray and white matter regions, with distribution in major gray matter areas ranked generally similar to that of PET binding in second-generation radiotracer studies. TSPO protein concentration in frontal cortex was high at birth, declined precipitously during the first three months, and increased modestly during adulthood/senescence (10%/decade; vs. 30% for comparison astrocytic marker GFAP). As expected, TSPO protein levels were significantly increased (+114%) in degenerating putamen in multiple system atrophy, providing further circumstantial support for TSPO as a gliosis marker. Overall, findings show some similarities between TSPO protein and PET binding characteristics in the human brain but also suggest that part of the TSPO protein pool might be less available for radioligand binding.
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Affiliation(s)
- Junchao Tong
- Preclinical Imaging, Research Imaging
Centre, Centre for Addiction and Mental Health, Toronto, Ontario, Canada
- Human Brain Laboratory, Research Imaging
Centre, Centre for Addiction and Mental Health, Toronto, Ontario, Canada
- Research Imaging Centre and Campbell
Family Mental Health Research Institute, Centre for Addiction and Mental Health,
Toronto, Ontario, Canada
- Junchao Tong, Preclinical Imaging, Centre
for Addiction and Mental Health, 250 College Street, Toronto, Ontario M5T 1R8,
Canada.
| | - Belinda Williams
- Human Brain Laboratory, Research Imaging
Centre, Centre for Addiction and Mental Health, Toronto, Ontario, Canada
- Addiction Imaging Research Group,
Research Imaging Centre, Centre for Addiction and Mental Health, Toronto, Ontario,
Canada
| | - Pablo M. Rusjan
- Research Imaging Centre and Campbell
Family Mental Health Research Institute, Centre for Addiction and Mental Health,
Toronto, Ontario, Canada
| | - Romina Mizrahi
- Research Imaging Centre and Campbell
Family Mental Health Research Institute, Centre for Addiction and Mental Health,
Toronto, Ontario, Canada
| | - Jean-Jacques Lacapère
- Sorbonne Universités-UPMC University of
Paris 06, Département de Chimie, École Normale Supérieure-PSL Research University,
Paris, France
| | - Tina McCluskey
- Human Brain Laboratory, Research Imaging
Centre, Centre for Addiction and Mental Health, Toronto, Ontario, Canada
- Research Imaging Centre and Campbell
Family Mental Health Research Institute, Centre for Addiction and Mental Health,
Toronto, Ontario, Canada
| | - Yoshiaki Furukawa
- Department of Neurology, Juntendo Tokyo
Koto Geriatric Medical Center, and Faculty of Medicine, University & Post
Graduate University of Juntendo, Tokyo, Japan
| | - Mark Guttman
- Centre for Movement Disorders, Toronto,
Ontario, Canada
| | - Lee-Cyn Ang
- Division of Neuropathology, London
Health Science Centre, University of Western Ontario, London, Ontario, Canada
| | - Isabelle Boileau
- Research Imaging Centre and Campbell
Family Mental Health Research Institute, Centre for Addiction and Mental Health,
Toronto, Ontario, Canada
- Addiction Imaging Research Group,
Research Imaging Centre, Centre for Addiction and Mental Health, Toronto, Ontario,
Canada
| | - Jeffrey H Meyer
- Research Imaging Centre and Campbell
Family Mental Health Research Institute, Centre for Addiction and Mental Health,
Toronto, Ontario, Canada
| | - Stephen J Kish
- Human Brain Laboratory, Research Imaging
Centre, Centre for Addiction and Mental Health, Toronto, Ontario, Canada
- Research Imaging Centre and Campbell
Family Mental Health Research Institute, Centre for Addiction and Mental Health,
Toronto, Ontario, Canada
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Bezukladova S, Tuisku J, Matilainen M, Vuorimaa A, Nylund M, Smith S, Sucksdorff M, Mohammadian M, Saunavaara V, Laaksonen S, Rokka J, Rinne JO, Rissanen E, Airas L. Insights into disseminated MS brain pathology with multimodal diffusion tensor and PET imaging. NEUROLOGY(R) NEUROIMMUNOLOGY & NEUROINFLAMMATION 2020; 7:e691. [PMID: 32123046 PMCID: PMC7136049 DOI: 10.1212/nxi.0000000000000691] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/11/2019] [Accepted: 01/09/2020] [Indexed: 01/30/2023]
Abstract
OBJECTIVE To evaluate in vivo the co-occurrence of microglial activation and microstructural white matter (WM) damage in the MS brain and to examine their association with clinical disability. METHODS 18-kDa translocator protein (TSPO) brain PET imaging was performed for evaluation of microglial activation by using the radioligand [11C](R)-PK11195. TSPO binding was evaluated as the distribution volume ratio (DVR) from dynamic PET images. Diffusion tensor imaging (DTI) and conventional MRI (cMRI) were performed at the same time. Mean fractional anisotropy (FA) and mean (MD), axial, and radial (RD) diffusivities were calculated within the whole normal-appearing WM (NAWM) and segmented NAWM regions appearing normal in cMRI. Fifty-five patients with MS and 15 healthy controls (HCs) were examined. RESULTS Microstructural damage was observed in the NAWM of the MS brain. DTI parameters of patients with MS were significantly altered in the NAWM compared with an age- and sex-matched HC group: mean FA was decreased, and MD and RD were increased. These structural abnormalities correlated with increased TSPO binding in the whole NAWM and in the temporal NAWM (p < 0.05 for all correlations; p < 0.01 for RD in the temporal NAWM). Both compromised WM integrity and increased microglial activation in the NAWM correlated significantly with higher clinical disability measured with the Expanded Disability Status Scale score. CONCLUSIONS Widespread structural disruption in the NAWM is linked to neuroinflammation, and both phenomena associate with clinical disability. Multimodal PET and DTI allow in vivo evaluation of widespread MS pathology not visible using cMRI.
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Affiliation(s)
- Svetlana Bezukladova
- From the Turku PET Centre (S.B., J.T., M. Matilainen, A.V., M.N., S.S., M.S., M. Mohammadian, V.S., S.L., J.R., J.O.R., E.R., L.A.), University of Turku and Turku University Hospital; Division of Clinical Neurosciences (A.V., M.N., S.S., M.S., S.L., E.R., L.A.), Turku University Hospital; and Department of Medical Physics (V.S.), Division of Medical Imaging, Turku University Hospital, Finland
| | - Jouni Tuisku
- From the Turku PET Centre (S.B., J.T., M. Matilainen, A.V., M.N., S.S., M.S., M. Mohammadian, V.S., S.L., J.R., J.O.R., E.R., L.A.), University of Turku and Turku University Hospital; Division of Clinical Neurosciences (A.V., M.N., S.S., M.S., S.L., E.R., L.A.), Turku University Hospital; and Department of Medical Physics (V.S.), Division of Medical Imaging, Turku University Hospital, Finland
| | - Markus Matilainen
- From the Turku PET Centre (S.B., J.T., M. Matilainen, A.V., M.N., S.S., M.S., M. Mohammadian, V.S., S.L., J.R., J.O.R., E.R., L.A.), University of Turku and Turku University Hospital; Division of Clinical Neurosciences (A.V., M.N., S.S., M.S., S.L., E.R., L.A.), Turku University Hospital; and Department of Medical Physics (V.S.), Division of Medical Imaging, Turku University Hospital, Finland
| | - Anna Vuorimaa
- From the Turku PET Centre (S.B., J.T., M. Matilainen, A.V., M.N., S.S., M.S., M. Mohammadian, V.S., S.L., J.R., J.O.R., E.R., L.A.), University of Turku and Turku University Hospital; Division of Clinical Neurosciences (A.V., M.N., S.S., M.S., S.L., E.R., L.A.), Turku University Hospital; and Department of Medical Physics (V.S.), Division of Medical Imaging, Turku University Hospital, Finland
| | - Marjo Nylund
- From the Turku PET Centre (S.B., J.T., M. Matilainen, A.V., M.N., S.S., M.S., M. Mohammadian, V.S., S.L., J.R., J.O.R., E.R., L.A.), University of Turku and Turku University Hospital; Division of Clinical Neurosciences (A.V., M.N., S.S., M.S., S.L., E.R., L.A.), Turku University Hospital; and Department of Medical Physics (V.S.), Division of Medical Imaging, Turku University Hospital, Finland
| | - Sarah Smith
- From the Turku PET Centre (S.B., J.T., M. Matilainen, A.V., M.N., S.S., M.S., M. Mohammadian, V.S., S.L., J.R., J.O.R., E.R., L.A.), University of Turku and Turku University Hospital; Division of Clinical Neurosciences (A.V., M.N., S.S., M.S., S.L., E.R., L.A.), Turku University Hospital; and Department of Medical Physics (V.S.), Division of Medical Imaging, Turku University Hospital, Finland
| | - Marcus Sucksdorff
- From the Turku PET Centre (S.B., J.T., M. Matilainen, A.V., M.N., S.S., M.S., M. Mohammadian, V.S., S.L., J.R., J.O.R., E.R., L.A.), University of Turku and Turku University Hospital; Division of Clinical Neurosciences (A.V., M.N., S.S., M.S., S.L., E.R., L.A.), Turku University Hospital; and Department of Medical Physics (V.S.), Division of Medical Imaging, Turku University Hospital, Finland
| | - Mehrbod Mohammadian
- From the Turku PET Centre (S.B., J.T., M. Matilainen, A.V., M.N., S.S., M.S., M. Mohammadian, V.S., S.L., J.R., J.O.R., E.R., L.A.), University of Turku and Turku University Hospital; Division of Clinical Neurosciences (A.V., M.N., S.S., M.S., S.L., E.R., L.A.), Turku University Hospital; and Department of Medical Physics (V.S.), Division of Medical Imaging, Turku University Hospital, Finland
| | - Virva Saunavaara
- From the Turku PET Centre (S.B., J.T., M. Matilainen, A.V., M.N., S.S., M.S., M. Mohammadian, V.S., S.L., J.R., J.O.R., E.R., L.A.), University of Turku and Turku University Hospital; Division of Clinical Neurosciences (A.V., M.N., S.S., M.S., S.L., E.R., L.A.), Turku University Hospital; and Department of Medical Physics (V.S.), Division of Medical Imaging, Turku University Hospital, Finland
| | - Sini Laaksonen
- From the Turku PET Centre (S.B., J.T., M. Matilainen, A.V., M.N., S.S., M.S., M. Mohammadian, V.S., S.L., J.R., J.O.R., E.R., L.A.), University of Turku and Turku University Hospital; Division of Clinical Neurosciences (A.V., M.N., S.S., M.S., S.L., E.R., L.A.), Turku University Hospital; and Department of Medical Physics (V.S.), Division of Medical Imaging, Turku University Hospital, Finland
| | - Johanna Rokka
- From the Turku PET Centre (S.B., J.T., M. Matilainen, A.V., M.N., S.S., M.S., M. Mohammadian, V.S., S.L., J.R., J.O.R., E.R., L.A.), University of Turku and Turku University Hospital; Division of Clinical Neurosciences (A.V., M.N., S.S., M.S., S.L., E.R., L.A.), Turku University Hospital; and Department of Medical Physics (V.S.), Division of Medical Imaging, Turku University Hospital, Finland
| | - Juha O Rinne
- From the Turku PET Centre (S.B., J.T., M. Matilainen, A.V., M.N., S.S., M.S., M. Mohammadian, V.S., S.L., J.R., J.O.R., E.R., L.A.), University of Turku and Turku University Hospital; Division of Clinical Neurosciences (A.V., M.N., S.S., M.S., S.L., E.R., L.A.), Turku University Hospital; and Department of Medical Physics (V.S.), Division of Medical Imaging, Turku University Hospital, Finland
| | - Eero Rissanen
- From the Turku PET Centre (S.B., J.T., M. Matilainen, A.V., M.N., S.S., M.S., M. Mohammadian, V.S., S.L., J.R., J.O.R., E.R., L.A.), University of Turku and Turku University Hospital; Division of Clinical Neurosciences (A.V., M.N., S.S., M.S., S.L., E.R., L.A.), Turku University Hospital; and Department of Medical Physics (V.S.), Division of Medical Imaging, Turku University Hospital, Finland
| | - Laura Airas
- From the Turku PET Centre (S.B., J.T., M. Matilainen, A.V., M.N., S.S., M.S., M. Mohammadian, V.S., S.L., J.R., J.O.R., E.R., L.A.), University of Turku and Turku University Hospital; Division of Clinical Neurosciences (A.V., M.N., S.S., M.S., S.L., E.R., L.A.), Turku University Hospital; and Department of Medical Physics (V.S.), Division of Medical Imaging, Turku University Hospital, Finland.
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63
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Fragola G, Mabb AM, Taylor-Blake B, Niehaus JK, Chronister WD, Mao H, Simon JM, Yuan H, Li Z, McConnell MJ, Zylka MJ. Deletion of Topoisomerase 1 in excitatory neurons causes genomic instability and early onset neurodegeneration. Nat Commun 2020; 11:1962. [PMID: 32327659 PMCID: PMC7181881 DOI: 10.1038/s41467-020-15794-9] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2019] [Accepted: 03/28/2020] [Indexed: 12/14/2022] Open
Abstract
Topoisomerase 1 (TOP1) relieves torsional stress in DNA during transcription and facilitates the expression of long (>100 kb) genes, many of which are important for neuronal functions. To evaluate how loss of Top1 affected neurons in vivo, we conditionally deleted (cKO) Top1 in postmitotic excitatory neurons in the mouse cerebral cortex and hippocampus. Top1 cKO neurons develop properly, but then show biased transcriptional downregulation of long genes, signs of DNA damage, neuroinflammation, increased poly(ADP-ribose) polymerase-1 (PARP1) activity, single-cell somatic mutations, and ultimately degeneration. Supplementation of nicotinamide adenine dinucleotide (NAD+) with nicotinamide riboside partially blocked neurodegeneration, and increased the lifespan of Top1 cKO mice by 30%. A reduction of p53 also partially rescued cortical neuron loss. While neurodegeneration was partially rescued, behavioral decline was not prevented. These data indicate that reducing neuronal loss is not sufficient to limit behavioral decline when TOP1 function is disrupted. Topoisomerase 1 (TOP1) relieves DNA torsional stress during transcription and facilitates the expression of long neuronal genes. Here we show that deletion of Top1 in excitatory neurons leads to early onset neurodegeneration that is partially dependent on p53/PARP1 activation and NAD+ depletion.
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Affiliation(s)
- Giulia Fragola
- Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA.,UNC Neuroscience Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Angela M Mabb
- Neuroscience Institute, Georgia State University, Atlanta, GA, 30303, USA
| | - Bonnie Taylor-Blake
- Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA.,UNC Neuroscience Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Jesse K Niehaus
- UNC Neuroscience Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - William D Chronister
- Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, Charlottesville, VA, 22908, USA
| | - Hanqian Mao
- Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA.,UNC Neuroscience Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Jeremy M Simon
- UNC Neuroscience Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA.,Department of Genetics, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA.,Carolina Institute for Developmental Disabilities, University of North Carolina School of Medicine, Chapel Hill, NC, 27599, USA
| | - Hong Yuan
- Department of Radiology, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA.,Biomedical Imaging Research Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Zibo Li
- Department of Radiology, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA.,Biomedical Imaging Research Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Michael J McConnell
- Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, Charlottesville, VA, 22908, USA.,Department of Neuroscience, University of Virginia School of Medicine, Charlottesville, VA, 22908, USA.,Center for Brain Immunology and Glia, University of Virginia School of Medicine, Charlottesville, VA, 22908, USA.,Center for Public Health Genomics, University of Virginia, School of Medicine, Charlottesville, VA, 22908, USA
| | - Mark J Zylka
- Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA. .,UNC Neuroscience Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA.
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64
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Yuan Y, Wu C, Ling EA. Heterogeneity of Microglia Phenotypes: Developmental, Functional and Some Therapeutic Considerations. Curr Pharm Des 2020; 25:2375-2393. [PMID: 31584369 DOI: 10.2174/1381612825666190722114248] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Accepted: 07/12/2019] [Indexed: 02/06/2023]
Abstract
BACKGROUND Microglia play a pivotal role in maintaining homeostasis in complex brain environment. They first exist as amoeboid microglial cells (AMCs) in the developing brain, but with brain maturation, they transform into ramified microglial cells (RMCs). In pathological conditions, microglia are activated and have been classified into M1 and M2 phenotypes. The roles of AMCs, RMCs and M1/M2 microglia phenotypes especially in pathological conditions have been the focus of many recent studies. METHODS Here, we review the early development of the AMCs and RMCs and discuss their specific functions with reference to their anatomic locations, immunochemical coding etc. M1 and M2 microglia phenotypes in different neuropathological conditions are also reviewed. RESULTS Activated microglia are engaged in phagocytosis, production of proinflammatory mediators, trophic factors and synaptogenesis etc. Prolonged microglia activation, however, can cause damage to neurons and oligodendrocytes. The M1 and M2 phenotypes featured prominently in pathological conditions are discussed in depth. Experimental evidence suggests that microglia phenotype is being modulated by multiple factors including external and internal stimuli, local demands, epigenetic regulation, and herbal compounds. CONCLUSION Prevailing views converge that M2 polarization is neuroprotective. Thus, proper therapeutic designs including the use of anti-inflammatory drugs, herbal agents may be beneficial in suppression of microglial activation, especially M1 phenotype, for amelioration of neuroinflammation in different neuropathological conditions. Finally, recent development of radioligands targeting 18 kDa translocator protein (TSPO) in activated microglia may hold great promises clinically for early detection of brain lesion with the positron emission tomography.
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Affiliation(s)
- Yun Yuan
- Department of Anatomy and Histology/Embryology, Kunming Medical University, 1168 West Chunrong Road, Kunming, China
| | - Chunyun Wu
- Department of Anatomy and Histology/Embryology, Kunming Medical University, 1168 West Chunrong Road, Kunming, China
| | - Eng-Ang Ling
- Department of Anatomy, Yong Loo Lin School of Medicine, 4 Medical Drive, MD10, National University of Singapore, 117594, Singapore
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65
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Betlazar C, Middleton RJ, Banati R, Liu GJ. The Translocator Protein (TSPO) in Mitochondrial Bioenergetics and Immune Processes. Cells 2020; 9:cells9020512. [PMID: 32102369 PMCID: PMC7072813 DOI: 10.3390/cells9020512] [Citation(s) in RCA: 66] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2020] [Revised: 02/19/2020] [Accepted: 02/19/2020] [Indexed: 12/11/2022] Open
Abstract
The translocator protein (TSPO) is an outer mitochondrial membrane protein that is widely used as a biomarker of neuroinflammation, being markedly upregulated in activated microglia in a range of brain pathologies. Despite its extensive use as a target in molecular imaging studies, the exact cellular functions of this protein remain in question. The long-held view that TSPO plays a fundamental role in the translocation of cholesterol through the mitochondrial membranes, and thus, steroidogenesis, has been disputed by several groups with the advent of TSPO knockout mouse models. Instead, much evidence is emerging that TSPO plays a fundamental role in cellular bioenergetics and associated mitochondrial functions, also part of a greater role in the innate immune processes of microglia. In this review, we examine the more direct experimental literature surrounding the immunomodulatory effects of TSPO. We also review studies which highlight a more central role for TSPO in mitochondrial processes, from energy metabolism, to the propagation of inflammatory responses through reactive oxygen species (ROS) modulation. In this way, we highlight a paradigm shift in approaches to TSPO functioning.
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Affiliation(s)
- Calina Betlazar
- Human Health, Australian Nuclear Science and Technology Organisation, New Illawarra Road, Lucas Heights, NSW 2234, Australia; (R.J.M.); (R.B.)
- Discipline of Medical Imaging & Radiation Sciences, Faculty of Medicine and Health, Brain and Mind Centre, University of Sydney, 94 Mallett Street, Camperdown, NSW 2050, Australia
- Correspondence: (C.B.); (G-J.L.)
| | - Ryan J. Middleton
- Human Health, Australian Nuclear Science and Technology Organisation, New Illawarra Road, Lucas Heights, NSW 2234, Australia; (R.J.M.); (R.B.)
| | - Richard Banati
- Human Health, Australian Nuclear Science and Technology Organisation, New Illawarra Road, Lucas Heights, NSW 2234, Australia; (R.J.M.); (R.B.)
- Discipline of Medical Imaging & Radiation Sciences, Faculty of Medicine and Health, Brain and Mind Centre, University of Sydney, 94 Mallett Street, Camperdown, NSW 2050, Australia
| | - Guo-Jun Liu
- Human Health, Australian Nuclear Science and Technology Organisation, New Illawarra Road, Lucas Heights, NSW 2234, Australia; (R.J.M.); (R.B.)
- Discipline of Medical Imaging & Radiation Sciences, Faculty of Medicine and Health, Brain and Mind Centre, University of Sydney, 94 Mallett Street, Camperdown, NSW 2050, Australia
- Correspondence: (C.B.); (G-J.L.)
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66
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Fu Y, Wang D, Wang H, Cai M, Li C, Zhang X, Chen H, Hu Y, Zhang X, Ying M, He W, Zhang J. TSPO deficiency induces mitochondrial dysfunction, leading to hypoxia, angiogenesis, and a growth-promoting metabolic shift toward glycolysis in glioblastoma. Neuro Oncol 2020; 22:240-252. [PMID: 31563962 PMCID: PMC7442372 DOI: 10.1093/neuonc/noz183] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
BACKGROUND The ligands of mitochondrial translocator protein (TSPO) have been widely used as diagnostic biomarkers for glioma. However, the true biological actions of TSPO in vivo and its role in glioma tumorigenesis remain elusive. METHODS TSPO knockout xenograft and spontaneous mouse glioma models were employed to assess the roles of TSPO in the pathogenesis of glioma. A Seahorse Extracellular Flux Analyzer was used to evaluate mitochondrial oxidative phosphorylation and glycolysis in TSPO knockout and wild-type glioma cells. RESULTS TSPO deficiency promoted glioma cell proliferation in vitro in mouse GL261 cells and patient-derived stem cell-like GBM1B cells. TSPO knockout increased glioma growth and angiogenesis in intracranial xenografts and a mouse spontaneous glioma model. Loss of TSPO resulted in a greater number of fragmented mitochondria, increased glucose uptake and lactic acid conversion, decreased oxidative phosphorylation, and increased glycolysis. CONCLUSION TSPO serves as a key regulator of glioma growth and malignancy by controlling the metabolic balance between mitochondrial oxidative phosphorylation and glycolysis.1. TSPO deficiency promotes glioma growth and angiogenesis.2. TSPO regulates the balance between mitochondrial oxidative phosphorylation and glycolysis.
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Affiliation(s)
- Yi Fu
- Department of Immunology, Research Center on Pediatric Development and Diseases, 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
| | - Dongdong Wang
- Department of Immunology, Research Center on Pediatric Development and Diseases, 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, Research Center on Pediatric Development and Diseases, 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, Research Center on Pediatric Development and Diseases, 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 Li
- Department of Immunology, Research Center on Pediatric Development and Diseases, 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, Research Center on Pediatric Development and Diseases, 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, Research Center on Pediatric Development and Diseases, 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, Research Center on Pediatric Development and Diseases, 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
| | - Xuan Zhang
- Department of Rheumatology and Clinical Immunology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Mingyao Ying
- Hugo W. Moser Research Institute at Kennedy Krieger, and Department of Neurology, Johns Hopkins School of Medicine, Baltimore, Maryland, USA
| | - Wei He
- Department of Immunology, Research Center on Pediatric Development and Diseases, 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, Research Center on Pediatric Development and Diseases, 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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The Acute and Early Effects of Whole-Brain Irradiation on Glial Activation, Brain Metabolism, and Behavior: a Positron Emission Tomography Study. Mol Imaging Biol 2020; 22:1012-1020. [PMID: 32052277 PMCID: PMC7343765 DOI: 10.1007/s11307-020-01483-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Purpose Radiotherapy is a frequently applied treatment modality for brain tumors. Concomitant irradiation of normal brain tissue can induce various physiological responses. The aim of this study was to investigate whether acute and early-delayed effects of brain irradiation on glial activation and brain metabolism can be detected with positron emission tomography (PET) and whether these effects are correlated with behavioral changes. Procedures Rats underwent 0-, 10-, or 25-Gy whole-brain irradiation. At 3 and 31 days post irradiation, 1-(2-chlorophenyl)-N-[11C]methyl-(1-methylpropyl)-3-isoquinoline carboxamide ([11C]PK11195) and 2-deoxy-2-[18F]fluoro-d-glucose ([18F]FDG) PET scans were acquired to detect changes in glial activation (neuroinflammation) and glucose metabolism, respectively. The open-field test (OFT) was performed on days 6 and 27 to assess behavioral changes. Results Twenty-five-gray-irradiated rats showed higher [11C]PK11195 uptake in most brain regions than controls on day 3 (striatum, hypothalamus, accumbens, septum p < 0.05), although some brain regions had lower uptake (cerebellum, parietal association/retrosplenial visual cortex, frontal association/motor cortex, somatosensory cortex, p < 0.05). On day 31, several brain regions in 25-Gy-irradiated rats still showed significantly higher [11C]PK11195 uptake than controls and 10-Gy-irradiated group (p < 0.05). Within-group analysis showed that [11C]PK11195 uptake in individual brain regions of 25-Gy treated rats remained stable or slightly increased between days 3 and 31. In contrast, a significant reduction (p < 0.05) in tracer uptake between days 3 and 31 was found in all brain areas of controls and 10-Gy-irradiated animals. Moreover, 10-Gy treatment led to a significantly higher [18F]FDG uptake on day 3 (p < 0.05). [18F]FDG uptake decreased between days 3 and 31 in all groups; no significant differences between groups were observed anymore on day 31, except for increased uptake in the hypothalamus in the 10-Gy group. The OFT did not show any significant differences between groups. Conclusions Non-invasive PET imaging indicated that brain irradiation induces neuroinflammation and a metabolic flare, without causing acute or early-delayed behavioral changes. Electronic supplementary material The online version of this article (10.1007/s11307-020-01483-y) contains supplementary material, which is available to authorized users.
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Pannell M, Economopoulos V, Wilson TC, Kersemans V, Isenegger PG, Larkin JR, Smart S, Gilchrist S, Gouverneur V, Sibson NR. Imaging of translocator protein upregulation is selective for pro-inflammatory polarized astrocytes and microglia. Glia 2020; 68:280-297. [PMID: 31479168 PMCID: PMC6916298 DOI: 10.1002/glia.23716] [Citation(s) in RCA: 74] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2019] [Revised: 08/08/2019] [Accepted: 08/20/2019] [Indexed: 01/06/2023]
Abstract
Translocator protein (TSPO) expression is increased in activated glia, and has been used as a marker of neuroinflammation in PET imaging. However, the extent to which TSPO upregulation reflects a pro- or anti-inflammatory phenotype remains unclear. Our aim was to determine whether TSPO upregulation in astrocytes and microglia/macrophages is limited to a specific inflammatory phenotype. TSPO upregulation was assessed by flow cytometry in cultured astrocytes, microglia, and macrophages stimulated with lipopolysaccharide (LPS), tumor necrosis factor (TNF), or interleukin-4 (Il-4). Subsequently, mice were injected intracerebrally with either a TNF-inducing adenovirus (AdTNF) or IL-4. Glial expression of TSPO and pro-/anti-inflammatory markers was assessed by immunohistochemistry/fluorescence and flow cytometry. Finally, AdTNF or IL-4 injected mice underwent PET imaging with injection of the TSPO radioligand 18 F-DPA-713, followed by ex vivo autoradiography. TSPO expression was significantly increased in pro-inflammatory microglia/macrophages and astrocytes both in vitro, and in vivo after AdTNF injection (p < .001 vs. control hemisphere), determined both histologically and by FACS. Both PET imaging and autoradiography revealed a significant (p < .001) increase in 18 F-DPA-713 binding in the ipsilateral hemisphere of AdTNF-injected mice. In contrast, no increase in either TSPO expression assessed histologically and by FACS, or ligand binding by PET/autoradiography was observed after IL-4 injection. Taken together, these results suggest that TSPO imaging specifically reveals the pro-inflammatory population of activated glial cells in the brain in response to inflammatory stimuli. Since the inflammatory phenotype of glial cells is critical to their role in neurological disease, these findings may enhance the utility and application of TSPO imaging.
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Affiliation(s)
- Maria Pannell
- Department of OncologyCancer Research UK and Medical Research Council Oxford Institute for Radiation Oncology, University of OxfordOxfordUK
| | - Vasiliki Economopoulos
- Department of OncologyCancer Research UK and Medical Research Council Oxford Institute for Radiation Oncology, University of OxfordOxfordUK
| | | | - Veerle Kersemans
- Department of OncologyCancer Research UK and Medical Research Council Oxford Institute for Radiation Oncology, University of OxfordOxfordUK
| | | | - James R. Larkin
- Department of OncologyCancer Research UK and Medical Research Council Oxford Institute for Radiation Oncology, University of OxfordOxfordUK
| | - Sean Smart
- Department of OncologyCancer Research UK and Medical Research Council Oxford Institute for Radiation Oncology, University of OxfordOxfordUK
| | - Stuart Gilchrist
- Department of OncologyCancer Research UK and Medical Research Council Oxford Institute for Radiation Oncology, University of OxfordOxfordUK
| | | | - Nicola R. Sibson
- Department of OncologyCancer Research UK and Medical Research Council Oxford Institute for Radiation Oncology, University of OxfordOxfordUK
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69
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Backhaus P, Roll W, Beuker C, Zinnhardt B, Seifert R, Wenning C, Eisenblätter M, Thomas C, Schmidt-Pogoda A, Strunk D, Wagner S, Faust A, Tüttelmann F, Röpke A, Jacobs AH, Stummer W, Wiendl H, Meuth SG, Schäfers M, Grauer O, Minnerup J. Initial experience with [ 18F]DPA-714 TSPO-PET to image inflammation in primary angiitis of the central nervous system. Eur J Nucl Med Mol Imaging 2020; 47:2131-2141. [PMID: 31960097 PMCID: PMC7338821 DOI: 10.1007/s00259-019-04662-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2019] [Accepted: 12/16/2019] [Indexed: 12/16/2022]
Abstract
Purpose Primary angiitis of the central nervous system (PACNS) is a heterogeneous, rare, and poorly understood inflammatory disease. We aimed at non-invasive imaging of activated microglia/macrophages in patients with PACNS by PET-MRI targeting the translocator protein (TSPO) with [18F]DPA-714 to potentially assist differential diagnosis, therapy monitoring, and biopsy planning. Methods In total, nine patients with ischemic stroke and diagnosed or suspected PACNS underwent [18F]DPA-714-PET-MRI. Dynamic PET scanning was performed for 60 min after injection of 233 ± 19 MBq [18F]DPA-714, and MRI was simultaneously acquired. Results In two PACNS patients, [18F]DPA-714 uptake patterns exceeded MRI correlates of infarction, whereas uptake was confined to the infarct in four patients where initial suspicion of PACNS could not be confirmed. About three patients with PACNS or cerebral predominant lymphocytic vasculitis showed no or only faintly increased uptake. Short-term [18F]DPA-714-PET follow-up in a patient with PACNS showed reduced lesional [18F]DPA-714 uptake after anti-inflammatory treatment. Biopsy in the same patient pinpointed the source of tracer uptake to TSPO-expressing immune cells. Conclusions [18F]DPA-714-PET imaging may facilitate the diagnosis and treatment monitoring of PACNS. Further studies are needed to fully understand the potential of TSPO-PET in deciphering the heterogeneity of the disease. Electronic supplementary material The online version of this article (10.1007/s00259-019-04662-4) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Philipp Backhaus
- Department of Nuclear Medicine, University Hospital Münster, Münster, Germany. .,European Institute for Molecular Imaging, University of Münster, Münster, Germany.
| | - Wolfgang Roll
- Department of Nuclear Medicine, University Hospital Münster, Münster, Germany
| | - Carolin Beuker
- Department of Neurology with Institute of Translational Neurology, University Hospital Münster, Münster, Germany
| | - Bastian Zinnhardt
- Department of Nuclear Medicine, University Hospital Münster, Münster, Germany.,European Institute for Molecular Imaging, University of Münster, Münster, Germany
| | - Robert Seifert
- Department of Nuclear Medicine, University Hospital Münster, Münster, Germany.,European Institute for Molecular Imaging, University of Münster, Münster, Germany
| | - Christian Wenning
- Department of Nuclear Medicine, University Hospital Münster, Münster, Germany
| | - Michel Eisenblätter
- Institute of Clinical Radiology, University Hospital Münster, Münster, Germany
| | - Christian Thomas
- Institute of Neuropathology, University Hospital Münster, Münster, Germany
| | - Antje Schmidt-Pogoda
- Department of Neurology with Institute of Translational Neurology, University Hospital Münster, Münster, Germany
| | - Daniel Strunk
- Department of Neurology with Institute of Translational Neurology, University Hospital Münster, Münster, Germany
| | - Stefan Wagner
- Department of Nuclear Medicine, University Hospital Münster, Münster, Germany
| | - Andreas Faust
- European Institute for Molecular Imaging, University of Münster, Münster, Germany
| | - Frank Tüttelmann
- Institute of Human Genetics, University Hospital Münster, Münster, Germany
| | - Albrecht Röpke
- Institute of Human Genetics, University Hospital Münster, Münster, Germany
| | - Andreas H Jacobs
- European Institute for Molecular Imaging, University of Münster, Münster, Germany.,Department of Geriatrics, Johanniter Hospital, Evangelische Kliniken, Bonn, Germany
| | - Walter Stummer
- Department of Neurosurgery, University Hospital Münster, Münster, Germany
| | - Heinz Wiendl
- Department of Neurology with Institute of Translational Neurology, University Hospital Münster, Münster, Germany
| | - Sven G Meuth
- Department of Neurology with Institute of Translational Neurology, University Hospital Münster, Münster, Germany
| | - Michael Schäfers
- Department of Nuclear Medicine, University Hospital Münster, Münster, Germany.,European Institute for Molecular Imaging, University of Münster, Münster, Germany
| | - Oliver Grauer
- Department of Neurology with Institute of Translational Neurology, University Hospital Münster, Münster, Germany
| | - Jens Minnerup
- Department of Neurology with Institute of Translational Neurology, University Hospital Münster, Münster, Germany
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Murtaj V, Belloli S, Di Grigoli G, Pannese M, Ballarini E, Rodriguez-Menendez V, Marmiroli P, Cappelli A, Masiello V, Monterisi C, Bellelli G, Panina-Bordignon P, Moresco RM. Age and Sex Influence the Neuro-inflammatory Response to a Peripheral Acute LPS Challenge. Front Aging Neurosci 2019; 11:299. [PMID: 31749696 PMCID: PMC6848890 DOI: 10.3389/fnagi.2019.00299] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2019] [Accepted: 10/17/2019] [Indexed: 12/21/2022] Open
Abstract
Aging is associated with an exaggerated response to peripheral inflammatory challenges together with behavioral and cognitive deficits. Studies considering both age and sex remain limited, despite sex dimorphism of astrocytes and microglial cells is largely recognized. To fill this knowledge gap, we investigated the effect of a single intraperitoneal lipopolysaccharide (LPS) administration in adult and aged mice. We assessed the expression of different inflammatory mediators, and the microglial response through binding of [18F]-VC701 tracer to translocator protein (TSPO) receptors in the male and female brain. Aged female brain showed a higher pro-inflammatory response to LPS compared to adult female and to aged male, as revealed by ex vivo binding to TSPO receptors and pro-inflammatory mediator transcript levels. The highest astroglial reaction was observed in the brain of aged females. Differently to the other groups of animals, in aged males LPS challenge did not affect transcription of triggering receptor expressed on myeloid cells 2 (TREM2). In conclusion, our study shows that in the mouse’s brain the neuro-inflammatory response to an acute peripheral insult is sex- and age-dependent. Moreover, our results might set the basis for further studies aimed at identifying sex-related targets involved in the modulation of the aberrant neuro-inflammatory response that characterizes aging. This knowledge could be relevant for the treatment of conditions such as delirium and dementia.
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Affiliation(s)
- Valentina Murtaj
- PhD Program in Neuroscience, School of Medicine and Surgery, University of Milano-Bicocca, Monza, Italy.,PET and Nuclear Medicine Unit, San Raffaele Scientific Institute, Milan, Italy
| | - Sara Belloli
- PET and Nuclear Medicine Unit, San Raffaele Scientific Institute, Milan, Italy.,Institute of Molecular Bioimaging and Physiology of National Reasearch Council, Segrate, Italy
| | - Giuseppe Di Grigoli
- PET and Nuclear Medicine Unit, San Raffaele Scientific Institute, Milan, Italy.,Institute of Molecular Bioimaging and Physiology of National Reasearch Council, Segrate, Italy
| | - Maria Pannese
- Neuroimmunology Unit, Division of Neuroscience, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Elisa Ballarini
- Milan Center for Neuroscience, School of Medicine and Surgery, University of Milano-Bicocca, Monza, Italy.,Department of Medicine and Surgery, Tecnomed Foundation, University of Milano-Bicocca, Monza, Italy
| | - Virginia Rodriguez-Menendez
- Milan Center for Neuroscience, School of Medicine and Surgery, University of Milano-Bicocca, Monza, Italy.,Department of Medicine and Surgery, Tecnomed Foundation, University of Milano-Bicocca, Monza, Italy
| | - Paola Marmiroli
- Milan Center for Neuroscience, School of Medicine and Surgery, University of Milano-Bicocca, Monza, Italy.,Department of Medicine and Surgery, Tecnomed Foundation, University of Milano-Bicocca, Monza, Italy
| | - Andrea Cappelli
- Department of Biotechnology, Chemistry and Pharmacy, University of Siena, Siena, Italy
| | - Valeria Masiello
- PET and Nuclear Medicine Unit, San Raffaele Scientific Institute, Milan, Italy
| | - Cristina Monterisi
- Department of Medicine and Surgery, Tecnomed Foundation, University of Milano-Bicocca, Monza, Italy
| | - Giuseppe Bellelli
- Acute Geriatric Unit, School of Medicine and Surgery, San Gerardo Hospital, University of Milano-Bicocca, Monza, Italy
| | - Paola Panina-Bordignon
- Neuroimmunology Unit, Division of Neuroscience, IRCCS San Raffaele Scientific Institute, Milan, Italy.,School of Medicine and Surgery, San Raffaele Vita-Salute University, Milan, Italy
| | - Rosa Maria Moresco
- PET and Nuclear Medicine Unit, San Raffaele Scientific Institute, Milan, Italy.,Department of Medicine and Surgery, Tecnomed Foundation, University of Milano-Bicocca, Monza, Italy
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Yilmaz C, Karali K, Fodelianaki G, Gravanis A, Chavakis T, Charalampopoulos I, Alexaki VI. Neurosteroids as regulators of neuroinflammation. Front Neuroendocrinol 2019; 55:100788. [PMID: 31513776 DOI: 10.1016/j.yfrne.2019.100788] [Citation(s) in RCA: 118] [Impact Index Per Article: 23.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/20/2019] [Revised: 08/12/2019] [Accepted: 09/07/2019] [Indexed: 02/07/2023]
Abstract
Neuroinflammation is a physiological protective response in the context of infection and injury. However, neuroinflammation, especially if chronic, may also drive neurodegeneration. Neurodegenerative diseases, such as multiple sclerosis (MS), Alzheimer's disease (AD), Parkinson's disease (PD) and traumatic brain injury (TBI), display inflammatory activation of microglia and astrocytes. Intriguingly, the central nervous system (CNS) is a highly steroidogenic environment synthesizing steroids de novo, as well as metabolizing steroids deriving from the circulation. Neurosteroid synthesis can be substantially affected by neuroinflammation, while, in turn, several steroids, such as 17β-estradiol, dehydroepiandrosterone (DHEA) and allopregnanolone, can regulate neuroinflammatory responses. Here, we review the role of neurosteroids in neuroinflammation in the context of MS, AD, PD and TBI and describe underlying molecular mechanisms. Moreover, we introduce the concept that synthetic neurosteroid analogues could be potentially utilized for the treatment of neurodegenerative diseases in the future.
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Affiliation(s)
- Canelif Yilmaz
- Institute of Clinical Chemistry and Laboratory Medicine, University Clinic Carl Gustav Carus, TU Dresden, 01307 Dresden, Germany
| | - Kanelina Karali
- Department of Pharmacology, Medical School, University of Crete, Heraklion, Greece; Institute of Molecular Biology & Biotechnology, Foundation of Research & Technology-Hellas, Heraklion, Greece
| | - Georgia Fodelianaki
- Institute of Clinical Chemistry and Laboratory Medicine, University Clinic Carl Gustav Carus, TU Dresden, 01307 Dresden, Germany
| | - Achille Gravanis
- Department of Pharmacology, Medical School, University of Crete, Heraklion, Greece; Institute of Molecular Biology & Biotechnology, Foundation of Research & Technology-Hellas, Heraklion, Greece
| | - Triantafyllos Chavakis
- Institute of Clinical Chemistry and Laboratory Medicine, University Clinic Carl Gustav Carus, TU Dresden, 01307 Dresden, Germany; Centre for Cardiovascular Science, Queen's Medical Research Institute, University of Edinburgh, Edinburgh, UK
| | - Ioannis Charalampopoulos
- Department of Pharmacology, Medical School, University of Crete, Heraklion, Greece; Institute of Molecular Biology & Biotechnology, Foundation of Research & Technology-Hellas, Heraklion, Greece
| | - Vasileia Ismini Alexaki
- Institute of Clinical Chemistry and Laboratory Medicine, University Clinic Carl Gustav Carus, TU Dresden, 01307 Dresden, Germany.
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Wu CY, Chen YY, Lin JJ, Li JP, Chen JK, Hsieh TC, Kao CH. Development of a novel radioligand for imaging 18-kD translocator protein (TSPO) in a rat model of Parkinson's disease. BMC Med Imaging 2019; 19:78. [PMID: 31533645 PMCID: PMC6751751 DOI: 10.1186/s12880-019-0375-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2019] [Accepted: 08/18/2019] [Indexed: 01/24/2023] Open
Abstract
Purpose The inflammation reaction in the brain may stimulate damage repair or possibly lead to secondary brain injury. It is often associated with activated microglia, which would overexpress 18-kDa translocator protein (TSPO). In this study, we successfully developed a new TSPO radioligand, [18F]-2-(4-fluoro-2-(p-tolyloxy)phenyl)-1,2-dihydroisoquinolin-3(4H)-one ([18F]FTPQ), and evaluate its potential to noninvasively detect brain changes in a rat model of Parkinson’s disease (PD). Procedures The precursor (8) for [18F]FTPQ preparation was synthesized via six steps. Radiofluorination was carried out in the presence of a copper catalyst, and the crude product was purified by high-performance liquid chromatography (HPLC) to give the desired [18F]FTPQ. The rat model of PD was established by the injection of 6-OHDA into the right hemisphere of male 8-week-old Sprague-Dawley rats. MicroPET/CT imaging and immunohistochemistry (IHC) were performed to characterize the biological properties of [18F]FTPQ. Results The overall chemical yield for the precursor (8) was around 14% after multi-step synthesis. The radiofluorination efficiency of [18F]FTPQ was 60 ± 5%. After HPLC purification, the radiochemical purity was higher than 98%. The overall radiochemical yield was approximately 19%. The microPET/CT images demonstrated apparent striatum accumulation in the brains of PD rats at the first 30 min after intravenous injection of [18F]FTPQ. Besides, longitudinal imaging found the uptake of [18F]FTPQ in the brain may reflect the severity of PD. The radioactivity accumulated in the ipsilateral hemisphere of PD rats at 1, 2, and 3 weeks after 6-OHDA administration was 1.84 ± 0.26, 3.43 ± 0.45, and 5.58 ± 0.72%ID/mL, respectively. IHC revealed that an accumulation of microglia/macrophages and astrocytes in the 6-OHDA-injected hemisphere. Conclusions In this study, we have successfully synthesized [18F]FTPQ with acceptable radiochemical yield and demonstrated the feasibility of [18F]FTPQ as a TSPO radioligand for the noninvasive monitoring the disease progression of PD. Electronic supplementary material The online version of this article (10.1186/s12880-019-0375-8) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Chun-Yi Wu
- Department of Biomedical Imaging and Radiological Science, China Medical University, No.91, Hsueh-Shih Road, Taichung, Taiwan, 40402.,Master Program for Biomedical Engineering, China Medical University, No.91, Hsueh-Shih Road, Taichung, Taiwan, 40402
| | - Yang-Yi Chen
- Department of Biomedical Imaging and Radiological Sciences, National Yang-Ming University, No.155, Sec.2, Linong Street, Taipei, Taiwan, 11221
| | - Jia-Jia Lin
- Department of Biomedical Imaging and Radiological Science, China Medical University, No.91, Hsueh-Shih Road, Taichung, Taiwan, 40402
| | - Jui-Ping Li
- Institute of Biomedical Engineering and Nanomedicine, National Health Research Institutes, 35 Keyan Road, Zhunan, Miaoli County, Taiwan, 35053
| | - Jen-Kun Chen
- Institute of Biomedical Engineering and Nanomedicine, National Health Research Institutes, 35 Keyan Road, Zhunan, Miaoli County, Taiwan, 35053
| | - Te-Chun Hsieh
- Department of Biomedical Imaging and Radiological Science, China Medical University, No.91, Hsueh-Shih Road, Taichung, Taiwan, 40402. .,Graduate Institute of Biomedical Sciences and School of Medicine, College of Medicine, China Medical University, No.91, Hsueh-Shih Road, Taichung, Taiwan, 40402.
| | - Chia-Hung Kao
- Graduate Institute of Biomedical Sciences and School of Medicine, College of Medicine, China Medical University, No.91, Hsueh-Shih Road, Taichung, Taiwan, 40402. .,Department of Nuclear Medicine and PET Center, and Center of Augmented Intelligence in Healthcare, China Medical University Hospital, No. 2, Yude Road, North District, Taichung City, Taiwan, 40447. .,Department of Bioinformatics and Medical Engineering, Asia University, 500, Lioufeng Rd., Wufeng, Taichung, Taiwan, 41354.
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Rashid K, Akhtar-Schaefer I, Langmann T. Microglia in Retinal Degeneration. Front Immunol 2019; 10:1975. [PMID: 31481963 PMCID: PMC6710350 DOI: 10.3389/fimmu.2019.01975] [Citation(s) in RCA: 200] [Impact Index Per Article: 40.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2019] [Accepted: 08/05/2019] [Indexed: 12/18/2022] Open
Abstract
The retina is a complex tissue with multiple cell layers that are highly ordered. Its sophisticated structure makes it especially sensitive to external or internal perturbations that exceed the homeostatic range. This necessitates the continuous surveillance of the retina for the detection of noxious stimuli. This task is mainly performed by microglia cells, the resident tissue macrophages which confer neuroprotection against transient pathophysiological insults. However, under sustained pathological stimuli, microglial inflammatory responses become dysregulated, often worsening disease pathology. In this review, we provide an overview of recent studies that depict microglial responses in diverse retinal pathologies that have degeneration and chronic immune reactions as key pathophysiological components. We also discuss innovative immunomodulatory therapy strategies that dampen the detrimental immunological responses to improve disease outcome.
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Affiliation(s)
- Khalid Rashid
- Laboratory for Experimental Immunology of the Eye, Department of Ophthalmology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - Isha Akhtar-Schaefer
- Laboratory for Experimental Immunology of the Eye, Department of Ophthalmology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - Thomas Langmann
- Laboratory for Experimental Immunology of the Eye, Department of Ophthalmology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany.,Center for Molecular Medicine Cologne, Cologne, Germany
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Dahoun T, Calcia MA, Veronese M, Bloomfield P, Reis Marques T, Turkheimer F, Howes OD. The association of psychosocial risk factors for mental health with a brain marker altered by inflammation: A translocator protein (TSPO) PET imaging study. Brain Behav Immun 2019; 80:742-750. [PMID: 31112791 DOI: 10.1016/j.bbi.2019.05.023] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/16/2019] [Accepted: 05/16/2019] [Indexed: 12/11/2022] Open
Abstract
Psychiatric disorders associated with psychosocial risk factors, including depression and psychosis, have been shown to demonstrate increased microglia activity. Whilst preclinical studies indicate that psychosocial stress leads to increased levels of microglia in the frontal cortex, no study has yet been performed in humans. This study aimed at investigating whether psychosocial risk factors for depression and/or psychosis would be associated with alterations in a brain marker expressed by microglia, the translocator specific protein (TSPO) in humans. We used [11C]-PBR28 Positron Emission Tomography on healthy subjects exposed to childhood and adulthood psychosocial risk factors (high-risk group, N = 12) and age- and sex-matched healthy controls not exposed to childhood and adulthood psychosocial risk factors (low-risk group, N = 12). The [11C]-PBR28 volume of distribution (VT) and Distribution Volume Ratio (DVR) were measured in the total gray matter, and frontal, parietal, temporal, occipital lobes. Levels of childhood trauma, anxiety and depression were measured using respectively the Childhood Trauma Questionnaire, State-anxiety questionnaire and Beck Depression Inventory. Compared to the low-risk group, the high-risk group did not exhibit significant differences in the mean [11C]-PBR28 VT (F(1,20) = 1.619, p = 0.218) or DVR (F(1,22) = 0.952, p = 0.340) on any region. There were no significant correlations between the [11C]-PBR28 VT and DVRs in total gray matter and frontal lobe and measures of childhood trauma, anxiety and depression. Psychosocial risk factors for depression and/or psychosis are unlikely to be associated with alterations in [11C]-PBR28 binding, indicating that alterations in TSPO expression reported in these disorders is unlikely to be caused by psychosocial risk factors alone.
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Affiliation(s)
- Tarik Dahoun
- Psychiatric Imaging Group MRC London Institute of Medical Sciences, Hammersmith Hospital, London W12 0NN, UK; Institute of Clinical Sciences, Faculty of Medicine, Imperial College, Hammersmith Hospital, London W12 0NN, UK; Department of Psychiatry, University of Oxford, Warneford Hospital, Oxford OX37 JX, UK
| | - Marilia A Calcia
- Institute of Psychiatry, Neurology and Neuroscience (IoPPN), King's College London, London SE5 8AF, UK
| | - Mattia Veronese
- Centre for Neuroimaging Sciences, Institute of Psychiatry, Neurology and Neuroscience (IoPPN), King's College London, London SE5 8AF, UK
| | - Peter Bloomfield
- Psychiatric Imaging Group MRC London Institute of Medical Sciences, Hammersmith Hospital, London W12 0NN, UK; Institute of Clinical Sciences, Faculty of Medicine, Imperial College, Hammersmith Hospital, London W12 0NN, UK
| | - Tiago Reis Marques
- Psychiatric Imaging Group MRC London Institute of Medical Sciences, Hammersmith Hospital, London W12 0NN, UK; Institute of Clinical Sciences, Faculty of Medicine, Imperial College, Hammersmith Hospital, London W12 0NN, UK; Institute of Psychiatry, Neurology and Neuroscience (IoPPN), King's College London, London SE5 8AF, UK
| | - Federico Turkheimer
- Centre for Neuroimaging Sciences, Institute of Psychiatry, Neurology and Neuroscience (IoPPN), King's College London, London SE5 8AF, UK
| | - Oliver D Howes
- Psychiatric Imaging Group MRC London Institute of Medical Sciences, Hammersmith Hospital, London W12 0NN, UK; Institute of Clinical Sciences, Faculty of Medicine, Imperial College, Hammersmith Hospital, London W12 0NN, UK; Institute of Psychiatry, Neurology and Neuroscience (IoPPN), King's College London, London SE5 8AF, UK.
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75
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Xia Y, Ledwitch K, Kuenze G, Duran A, Li J, Sanders CR, Manning C, Meiler J. A unified structural model of the mammalian translocator protein (TSPO). JOURNAL OF BIOMOLECULAR NMR 2019; 73:347-364. [PMID: 31243635 PMCID: PMC8006375 DOI: 10.1007/s10858-019-00257-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2019] [Accepted: 06/10/2019] [Indexed: 05/10/2023]
Abstract
The translocator protein (TSPO), previously known as the peripheral benzodiazepine receptor (PBR), is a membrane protein located on the outer mitochondrial membrane. Experimentally-derived structures of mouse TSPO (mTSPO) and its homologs from bacterial species have been determined by NMR spectroscopy and X-ray crystallography, respectively. These structures and ligand interactions within the TSPO binding pocket display distinct differences. Here, we leverage experimental and computational studies to derive a unified structural model of mTSPO in the presence and absence of the TSPO ligand, PK11195, and study the effects of DPC detergent micelles on the TSPO structure and ligand binding. From this work, we conclude that that the lipid-mimetic system used to solubilize mTSPO for NMR studies thermodynamically destabilizes the protein, introduces structural perturbations, and alters the characteristics of ligand binding. Furthermore, we used Rosetta to construct a unified mTSPO model that reconciles deviating features of the mammalian and bacterial TSPO. These deviating features are likely a consequence of the detergent system used for structure determination of mTSPO by NMR. The unified mTSPO model agrees with available experimental NMR data, appears to be physically realistic (i.e. thermodynamically not frustrated as judged by the Rosetta energy function), and simultaneously shares the structural features observed in sequence-conserved regions of the bacterial proteins. Finally, we identified the binding site for an imaging ligand VUIIS8310 that is currently positioned for clinical translation using NMR spectroscopy and propose a computational model of the VUIIS8310-mTSPO complex.
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Affiliation(s)
- Yan Xia
- Center for Structural Biology, Vanderbilt University, Nashville, TN, 37240, USA
- Department of Chemistry, Vanderbilt University, Nashville, TN, 37235, USA
| | - Kaitlyn Ledwitch
- Center for Structural Biology, Vanderbilt University, Nashville, TN, 37240, USA
- Department of Chemistry, Vanderbilt University, Nashville, TN, 37235, USA
| | - Georg Kuenze
- Center for Structural Biology, Vanderbilt University, Nashville, TN, 37240, USA
- Department of Chemistry, Vanderbilt University, Nashville, TN, 37235, USA
| | - Amanda Duran
- Center for Structural Biology, Vanderbilt University, Nashville, TN, 37240, USA
- Department of Chemistry, Vanderbilt University, Nashville, TN, 37235, USA
| | - Jun Li
- Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, TN, 37232, USA
| | - Charles R Sanders
- Department of Biochemistry, Vanderbilt University, Nashville, TN, 37240, USA
| | - Charles Manning
- Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, TN, 37232, USA
| | - Jens Meiler
- Center for Structural Biology, Vanderbilt University, Nashville, TN, 37240, USA.
- Department of Chemistry, Vanderbilt University, Nashville, TN, 37235, USA.
- Department of Chemistry, Center for Structural Biology, Vanderbilt University, MRBIII 5144B, Nashville, TN, 37232, USA.
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76
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Perani D, Iaccarino L, Lammertsma AA, Windhorst AD, Edison P, Boellaard R, Hansson O, Nordberg A, Jacobs AH. A new perspective for advanced positron emission tomography-based molecular imaging in neurodegenerative proteinopathies. Alzheimers Dement 2019; 15:1081-1103. [PMID: 31230910 DOI: 10.1016/j.jalz.2019.02.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2018] [Revised: 01/21/2019] [Accepted: 02/20/2019] [Indexed: 12/12/2022]
Abstract
Recent studies in neurodegenerative conditions have increasingly highlighted that the same neuropathology can trigger different clinical phenotypes or, vice-versa, that similar phenotypes can be triggered by different neuropathologies. This evidence has called for the adoption of a pathology spectrum-based approach to study neurodegenerative proteinopathies. These conditions share brain deposition of abnormal protein aggregates, leading to aberrant biochemical, metabolic, functional, and structural changes. Positron emission tomography (PET) is a well-recognized and unique tool for the in vivo assessment of brain neuropathology, and novel PET techniques are emerging for the study of specific protein species. Today, key applications of PET range from early research and clinical diagnostic tools to their use in clinical trials for both participants screening and outcome evaluation. This position article critically reviews the role of distinct PET molecular tracers for different neurodegenerative proteinopathies, highlighting their strengths, weaknesses, and opportunities, with special emphasis on methodological challenges and future applications.
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Affiliation(s)
- Daniela Perani
- Vita-Salute San Raffaele University, Nuclear Medicine Unit San Raffaele Hospital, Division of Neuroscience San Raffaele Scientific Institute, Milan, Italy
| | - Leonardo Iaccarino
- Vita-Salute San Raffaele University, Nuclear Medicine Unit San Raffaele Hospital, Division of Neuroscience San Raffaele Scientific Institute, Milan, Italy
| | - Adriaan A Lammertsma
- Department of Radiology and Nuclear Medicine, VU University Medical Center, Amsterdam, The Netherlands
| | - Albert D Windhorst
- Department of Radiology and Nuclear Medicine, VU University Medical Center, Amsterdam, The Netherlands
| | - Paul Edison
- Division of Brain Sciences, Department of Medicine, Imperial College London, London, UK; Neurology Imaging Unit, Imperial College London, London, UK
| | - Ronald Boellaard
- Department of Radiology and Nuclear Medicine, Amsterdam University Medical Centres, Amsterdam, The Netherlands
| | - Oskar Hansson
- Clinical Memory Research Unit, Department of Clinical Sciences, Lund University, Lund, Sweden; Memory Clinic, Skåne University Hospital, Malmö, Sweden
| | - Agneta Nordberg
- Division of Clinical Geriatrics, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Center for Alzheimer Research, Stockholm, Sweden
| | - Andreas H Jacobs
- European Institute for Molecular Imaging, University of Münster, Münster, Germany; Evangelische Kliniken Bonn gGmbH, Johanniter Krankenhaus, Bonn, Germany.
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77
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Kim B, Fukuda M, Lee J, Su D, Sanu S, Silvin A, Khoo ATT, Kwon T, Liu X, Chi W, Liu X, Choi S, Wan DSY, Park S, Kim J, Ginhoux F, Je HS, Chang Y. Visualizing Microglia with a Fluorescence Turn‐On Ugt1a7c Substrate. Angew Chem Int Ed Engl 2019. [DOI: 10.1002/ange.201903058] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Affiliation(s)
- Beomsue Kim
- Singapore Bioimaging Consortium Agency for Science Technology and Research (A*STAR) Singapore 138667 Singapore
| | - Masahiro Fukuda
- Program in Neuroscience and Behavioral Disorders Duke-NUS Medical School Singapore 169857 Singapore
| | - Jung‐Yeol Lee
- Department of Chemistry Pohang University of Science and Technology Pohang 37673 Korea
- Singapore Bioimaging Consortium Agency for Science Technology and Research (A*STAR) Singapore 138667 Singapore
- Present address: New drug discovery center DGMIF Daegu 41061 Korea
| | - Dongdong Su
- Singapore Bioimaging Consortium Agency for Science Technology and Research (A*STAR) Singapore 138667 Singapore
| | - Srikanta Sanu
- Singapore Bioimaging Consortium Agency for Science Technology and Research (A*STAR) Singapore 138667 Singapore
| | - Aymeric Silvin
- Singapore Immunology Network A*STAR Singapore 138648 Singapore
| | - Audrey T. T. Khoo
- Program in Neuroscience and Behavioral Disorders Duke-NUS Medical School Singapore 169857 Singapore
| | - Taejoon Kwon
- Department of Biomedical Engineering Ulsan National Institute of Science and Technology Ulsan 44919 Korea
| | - Xiao Liu
- Department of Chemistry Pohang University of Science and Technology Pohang 37673 Korea
- Center for Self-assembly and Complexity Institute for Basic Science (IBS) Pohang 37673 Korea
| | - Weijie Chi
- Singapore University of Technology and Design Singapore 487372 Singapore
| | - Xiaogang Liu
- Singapore University of Technology and Design Singapore 487372 Singapore
| | - Sejong Choi
- Department of Chemistry Seoul National University Seoul 08826 Korea
| | - Diana S. Y. Wan
- Singapore Bioimaging Consortium Agency for Science Technology and Research (A*STAR) Singapore 138667 Singapore
| | - Sung‐Jin Park
- Singapore Bioimaging Consortium Agency for Science Technology and Research (A*STAR) Singapore 138667 Singapore
| | - Jin‐Soo Kim
- Center for Genome Engineering IBS Daejeon 34047 Korea
| | - Florent Ginhoux
- Singapore Immunology Network A*STAR Singapore 138648 Singapore
| | - H. Shawn Je
- Program in Neuroscience and Behavioral Disorders Duke-NUS Medical School Singapore 169857 Singapore
| | - Young‐Tae Chang
- Department of Chemistry Pohang University of Science and Technology Pohang 37673 Korea
- Singapore Bioimaging Consortium Agency for Science Technology and Research (A*STAR) Singapore 138667 Singapore
- Center for Self-assembly and Complexity Institute for Basic Science (IBS) Pohang 37673 Korea
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78
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Rizzo G, Veronese M, Tonietto M, Bodini B, Stankoff B, Wimberley C, Lavisse S, Bottlaender M, Bloomfield PS, Howes O, Zanotti-Fregonara P, Turkheimer FE, Bertoldo A. Generalization of endothelial modelling of TSPO PET imaging: Considerations on tracer affinities. J Cereb Blood Flow Metab 2019; 39:874-885. [PMID: 29135382 PMCID: PMC6501510 DOI: 10.1177/0271678x17742004] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The 18 kDa translocator protein (TSPO) is a marker of microglia activation and the main target of positron emission tomography (PET) ligands for neuroinflammation. Previous works showed that accounting for TSPO endothelial binding improves PET quantification for [11C]PBR28, [18F]DPA714 and [11C]-R-PK11195. It is still unclear, however, whether the vascular signal is tracer-dependent. This work aims to explore the relationship between the TSPO vascular and tissue components for PET tracers with varying affinity, also assessing the impact of affinity towards the differentiability amongst kinetics and the ensuing ligand amenability to cluster analysis for the extraction of a reference region. First, we applied the compartmental model accounting for vascular binding to [11C]-R-PK11195 data from six healthy subjects. Then, we compared the [11C]-R-PK11195 vascular binding estimates with previously published values for [18F]DPA714 and [11C]PBR28. Finally, we determined the suitability for reference region extraction by calculating the angle between grey and white matter kinetics. Our results showed that endothelial binding is common to all TSPO tracers and proportional to their affinity. By consequence, grey and white matter kinetics were most similar for the radioligand with the highest affinity (i.e. [11C]PBR28), hence poorly suited for the extraction of a reference region using supervised clustering.
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Affiliation(s)
- Gaia Rizzo
- 1 Department of Information Engineering, Padova University, Padova, Italy
| | - Mattia Veronese
- 2 Department of Neuroimaging, King's College London, London, UK
| | - Matteo Tonietto
- 3 UPMC, Institut du Cerveau et de la Moelle épinière, Hôpital de la Pitié Salpêtrière, Sorbonne Universités, Paris, France
| | - Benedetta Bodini
- 3 UPMC, Institut du Cerveau et de la Moelle épinière, Hôpital de la Pitié Salpêtrière, Sorbonne Universités, Paris, France.,4 Assistance Publique des Hopitaux de Paris, APHP, Hôpital Saint Antoine, Paris, France
| | - Bruno Stankoff
- 3 UPMC, Institut du Cerveau et de la Moelle épinière, Hôpital de la Pitié Salpêtrière, Sorbonne Universités, Paris, France.,4 Assistance Publique des Hopitaux de Paris, APHP, Hôpital Saint Antoine, Paris, France.,5 IMIV, Inserm, CEA, Paris-Sud Univ, Université Paris Saclay, Orsay, France
| | - Catriona Wimberley
- 5 IMIV, Inserm, CEA, Paris-Sud Univ, Université Paris Saclay, Orsay, France
| | - Sonia Lavisse
- 6 Département de Recherche Fondamentale (DRF), Institut d'Imagerie Biomédicale (I2BM), Fontenay-aux-Roses, France.,7 Centre National de la Recherche Scientifique (CNRS), Université Paris-Sud, Université Paris-Saclay, Fontenay-aux-Roses, France
| | - Michel Bottlaender
- 5 IMIV, Inserm, CEA, Paris-Sud Univ, Université Paris Saclay, Orsay, France.,8 Neurospin, CEA, Gif-sur-Yvette, France
| | | | - Oliver Howes
- 9 Institute of Clinical Sciences, Imperial College London, London, UK.,10 Department of Psychosis Studies, King's College London, London, UK
| | - Paolo Zanotti-Fregonara
- 11 Houston Methodist Hospital, PET Core Facility, Research Institute, Stanley H. Appel Department of Neurology, Houston, Texas, USA
| | | | - Alessandra Bertoldo
- 1 Department of Information Engineering, Padova University, Padova, Italy.,12 Padua Neuroscience Center, University of Padova, Padova, Italy
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79
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Kim B, Fukuda M, Lee J, Su D, Sanu S, Silvin A, Khoo ATT, Kwon T, Liu X, Chi W, Liu X, Choi S, Wan DSY, Park S, Kim J, Ginhoux F, Je HS, Chang Y. Visualizing Microglia with a Fluorescence Turn‐On Ugt1a7c Substrate. Angew Chem Int Ed Engl 2019; 58:7972-7976. [DOI: 10.1002/anie.201903058] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2019] [Indexed: 12/26/2022]
Affiliation(s)
- Beomsue Kim
- Singapore Bioimaging Consortium Agency for Science Technology and Research (A*STAR) Singapore 138667 Singapore
| | - Masahiro Fukuda
- Program in Neuroscience and Behavioral Disorders Duke-NUS Medical School Singapore 169857 Singapore
| | - Jung‐Yeol Lee
- Department of Chemistry Pohang University of Science and Technology Pohang 37673 Korea
- Singapore Bioimaging Consortium Agency for Science Technology and Research (A*STAR) Singapore 138667 Singapore
- Present address: New drug discovery center DGMIF Daegu 41061 Korea
| | - Dongdong Su
- Singapore Bioimaging Consortium Agency for Science Technology and Research (A*STAR) Singapore 138667 Singapore
| | - Srikanta Sanu
- Singapore Bioimaging Consortium Agency for Science Technology and Research (A*STAR) Singapore 138667 Singapore
| | - Aymeric Silvin
- Singapore Immunology Network A*STAR Singapore 138648 Singapore
| | - Audrey T. T. Khoo
- Program in Neuroscience and Behavioral Disorders Duke-NUS Medical School Singapore 169857 Singapore
| | - Taejoon Kwon
- Department of Biomedical Engineering Ulsan National Institute of Science and Technology Ulsan 44919 Korea
| | - Xiao Liu
- Department of Chemistry Pohang University of Science and Technology Pohang 37673 Korea
- Center for Self-assembly and Complexity Institute for Basic Science (IBS) Pohang 37673 Korea
| | - Weijie Chi
- Singapore University of Technology and Design Singapore 487372 Singapore
| | - Xiaogang Liu
- Singapore University of Technology and Design Singapore 487372 Singapore
| | - Sejong Choi
- Department of Chemistry Seoul National University Seoul 08826 Korea
| | - Diana S. Y. Wan
- Singapore Bioimaging Consortium Agency for Science Technology and Research (A*STAR) Singapore 138667 Singapore
| | - Sung‐Jin Park
- Singapore Bioimaging Consortium Agency for Science Technology and Research (A*STAR) Singapore 138667 Singapore
| | - Jin‐Soo Kim
- Center for Genome Engineering IBS Daejeon 34047 Korea
| | - Florent Ginhoux
- Singapore Immunology Network A*STAR Singapore 138648 Singapore
| | - H. Shawn Je
- Program in Neuroscience and Behavioral Disorders Duke-NUS Medical School Singapore 169857 Singapore
| | - Young‐Tae Chang
- Department of Chemistry Pohang University of Science and Technology Pohang 37673 Korea
- Singapore Bioimaging Consortium Agency for Science Technology and Research (A*STAR) Singapore 138667 Singapore
- Center for Self-assembly and Complexity Institute for Basic Science (IBS) Pohang 37673 Korea
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80
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Synthesis and in vitro evaluation of new translocator protein ligands designed for positron emission tomography. Future Med Chem 2019; 11:539-550. [PMID: 30888874 DOI: 10.4155/fmc-2018-0444] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
AIM Dysregulated levels of the translocator protein TSPO 18 KDa have been reported in several disorders, particularly neurodegenerative diseases. This makes TSPO an interesting target for the development of diagnostic biomarkers. Even though several radioligands have already been developed for in vivo TSPO imaging, the ideal TSPO radiotracer has still not been found. RESULTS Here, we report the chemical synthesis of a set of new TSPO ligands designed for future application in positron emission tomography, together with the determination of their biological activity and applied 11C-labeling strategy. CONCLUSION The lead compound of our series, (R)-[11C]Me@NEBIQUINIDE, showed very promising results and is therefore proposed to be further evaluated under in vivo settings.
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81
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Konsman JP. Inflammation and Depression: A Nervous Plea for Psychiatry to Not Become Immune to Interpretation. Pharmaceuticals (Basel) 2019; 12:ph12010029. [PMID: 30769887 PMCID: PMC6469164 DOI: 10.3390/ph12010029] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2019] [Revised: 02/10/2019] [Accepted: 02/12/2019] [Indexed: 01/08/2023] Open
Abstract
The possibility that inflammation plays a causal role in major depression is an important claim in the emerging field of immunopsychiatry and has generated hope for new treatments. The aims of the present review are first to provide some historical background and to consider the evidence in favor of the claim that inflammation is causally involved in major depression. The second part discusses some of the possibilities allowed for by the use of broad ‘umbrella’ concepts, such as inflammation and stress, in terms of proposing new working hypotheses and potential mechanisms. The third part reviews proposed biomarkers of inflammation and depression and the final part addresses how elements discussed in the preceding sections are used in immunopsychiatry. The ‘umbrella’ concepts of inflammation and stress, as well as insufficiently-met criteria based inferences and reverse inferences are being used to some extent in immunopsychiatry. The field is therefore encouraged to specify concepts and constructs, as well as to consider potential alternative interpretations and explanations for findings obtained. The hope is that pointing out some of the potential problems will allow for a clearer picture of immunopsychiatry’s current strengths and limitations and help the field mature.
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Affiliation(s)
- Jan Pieter Konsman
- Aquitaine Institute for Integrative and Cognitive Neuroscience (INCIA) UMR CNRS 5287, University of Bordeaux, 146 rue Léo Saignat, 33076 Bordeaux, France.
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82
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Bisicchia E, Sasso V, Molinari M, Viscomi MT. Plasticity of microglia in remote regions after focal brain injury. Semin Cell Dev Biol 2019; 94:104-111. [PMID: 30703556 DOI: 10.1016/j.semcdb.2019.01.011] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2018] [Revised: 01/22/2019] [Accepted: 01/22/2019] [Indexed: 02/06/2023]
Abstract
The CNS is endowed with an intrinsic ability to recover from and adapt secondary compensatory mechanisms to injury. The basis of recovery stems from brain plasticity, defined as the brain's ability to make adaptive changes on structural and functional levels, ranging from molecular, synaptic, and cellular changes in response to alterations in their environment. In this multitude of responses, microglia have an active role and contribute to brain plasticity through their dynamic responses. This review will provide an overview of microglial responses in the context of acute CNS injury and their function in post-traumatic repair and assess the changes that are induced by damage in remote areas from, but functionally connected to, the primary site of injury. In the second section, we highlight the effects of several therapeutic approaches, with particular interest paid to specialized pro-resolving lipid mediators, in modulating microglial responses in remote regions and enhancing long-term functional recovery via suppression of neurodegenerative cascades that are induced by damage, which may contribute to a translational bridge from bench to bedside.
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Affiliation(s)
- Elisa Bisicchia
- Laboratory of Experimental Neurorehabilitation, IRCCS Santa Lucia Foundation, Rome, Italy
| | - Valeria Sasso
- Laboratory of Experimental Neurorehabilitation, IRCCS Santa Lucia Foundation, Rome, Italy
| | - Marco Molinari
- Laboratory of Experimental Neurorehabilitation, IRCCS Santa Lucia Foundation, Rome, Italy
| | - Maria Teresa Viscomi
- Fondazione Policlinico Universitario A. Gemelli, Università Cattolica del S. Cuore, Rome, Italy.
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Azrad M, Zeineh N, Weizman A, Veenman L, Gavish M. The TSPO Ligands 2-Cl-MGV-1, MGV-1, and PK11195 Differentially Suppress the Inflammatory Response of BV-2 Microglial Cell to LPS. Int J Mol Sci 2019; 20:ijms20030594. [PMID: 30704062 PMCID: PMC6387401 DOI: 10.3390/ijms20030594] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2018] [Revised: 01/16/2019] [Accepted: 01/18/2019] [Indexed: 02/07/2023] Open
Abstract
The 18 kDa Translocator Protein (TSPO) is a marker for microglial activation as its expression is enhanced in activated microglia during neuroinflammation. TSPO ligands can attenuate neuroinflammation and neurotoxicity. In the present study, we examined the efficacy of new TSPO ligands designed by our laboratory, MGV-1 and 2-Cl-MGV-1, in mitigating an in vitro neuroinflammatory process compared to the classic TSPO ligand, PK 11195. We exposed BV-2 microglial cells to lipopolysaccharide (LPS) for 24 h to induce inflammatory response and added the three TSPO ligands: (1) one hour before LPS treatment (pretreatment), (2) simultaneously with LPS (cotreatment), and (3) one hour after LPS exposure (post-treatment). We evaluated the capability of TSPO ligands to reduce the levels of three glial inflammatory markers: cyclooxygenase-2 (COX-2), inducible nitric oxide synthase (iNOS), and nitric oxide (NO). We compared the effects of the two novel ligands to PK 11195. Both 2-Cl-MGV-1 and MGV-1 reduced the levels of glial COX-2, iNOS, and NO in LPS-treated BV-2 cells more efficiently than PK 11195. Notably, even when added after exposure to LPS, all ligands were able to suppress the inflammatory response. Due to their pronounced anti-inflammatory activity, 2-Cl-MGV-1 and MGV-1 may serve as potential therapeutics in neuroinflammatory and neurodegenerative diseases.
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Affiliation(s)
- Maya Azrad
- The Ruth and Bruce Rappaport Faculty of Medicine, Technion Institute of Technology, Haifa 31096, Israel.
| | - Nidal Zeineh
- The Ruth and Bruce Rappaport Faculty of Medicine, Technion Institute of Technology, Haifa 31096, Israel.
| | - Abraham Weizman
- Research Unit at Geha Mental Health Center and the Laboratory of Biological Psychiatry, Felsenstein Medical Research Center, Petah Tikva 4910002, Israel.
- Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel.
| | - Leo Veenman
- The Ruth and Bruce Rappaport Faculty of Medicine, Technion Institute of Technology, Haifa 31096, Israel.
| | - Moshe Gavish
- The Ruth and Bruce Rappaport Faculty of Medicine, Technion Institute of Technology, Haifa 31096, Israel.
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84
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Horiguchi Y, Ohta N, Yamamoto S, Koide M, Fujino Y. Midazolam suppresses the lipopolysaccharide-stimulated immune responses of human macrophages via translocator protein signaling. Int Immunopharmacol 2019; 66:373-382. [DOI: 10.1016/j.intimp.2018.11.050] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2018] [Revised: 11/27/2018] [Accepted: 11/28/2018] [Indexed: 12/11/2022]
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85
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Luo LF, Weng JF, Cen M, Dong XQ, Yu WH, Du Q, Yang DB, Zheng YK, Hu W, Yu L, Luo SD. Prognostic significance of serum translocator protein in patients with traumatic brain injury. Clin Chim Acta 2019; 488:25-30. [DOI: 10.1016/j.cca.2018.10.035] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2018] [Revised: 10/28/2018] [Accepted: 10/28/2018] [Indexed: 10/28/2022]
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86
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Microglial markers in the frontal cortex are related to cognitive dysfunctions in major depressive disorder. J Affect Disord 2018; 241:305-310. [PMID: 30142589 DOI: 10.1016/j.jad.2018.08.021] [Citation(s) in RCA: 66] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/19/2018] [Revised: 07/14/2018] [Accepted: 08/07/2018] [Indexed: 12/27/2022]
Abstract
BACKGROUND Evidence suggests that microglia-mediated processes are implicated in the pathophysiology of major depressive disorder (MDD). The relationship between these processes and cognitive dysfunctions has not been explored. METHODS We recruited 50 never-medicated patients with MDD and 30 healthy control subjects. We used [18F]-FEPPA positron emission tomography (PET) to examine translocator protein total distribution volume (TSPO VT), a marker of microglia. Cognitive functions were evaluated with the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) (attention, immediate and delyed memory, language, and visuospatial functions). RESULTS Patients with MDD showed elevated TSPO VT in all regions of interest (white matter, grey matter, frontal cortex, temporal cortex, and hippocampus) and were impaired on the attention and delayed memory domains of the RBANS. In the frontal cortex, increased TSPO VT was associated with lower scores on the RBANS attention domain when the analysis was corrected for age, gender, education, and depressive symptoms. LIMITATIONS Affective functions were not investigated, the specificity of [18F]-FEPPA binding is limited, TSPO may reflect microglia/macrophage density rather than activation, and the sample was not balanced (more patients were included than controls). CONCLUSIONS Attentional dysfunctions may be associated with microglial pathology in the frontal cortex of untreated patients with MDD.
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87
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Suh M, Lee DS. Brain Theranostics and Radiotheranostics: Exosomes and Graphenes In Vivo as Novel Brain Theranostics. Nucl Med Mol Imaging 2018; 52:407-419. [PMID: 30538772 PMCID: PMC6261865 DOI: 10.1007/s13139-018-0550-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2018] [Revised: 09/10/2018] [Accepted: 10/05/2018] [Indexed: 12/17/2022] Open
Abstract
Brain disease is one of the greatest threats to public health. Brain theranostics is recently taking shape, indicating the treatments of stroke, inflammatory brain disorders, psychiatric diseases, neurodevelopmental disease, and neurodegenerative disease. However, several factors, such as lack of endophenotype classification, blood-brain barrier (BBB), target determination, ignorance of biodistribution after administration, and complex intercellular communication between brain cells, make brain theranostics application difficult, especially when it comes to clinical application. So, a more thorough understanding of each aspect is needed. In this review, we focus on recent studies regarding the role of exosomes in intercellular communication of brain cells, therapeutic effect of graphene quantum dots, transcriptomics/epitranscriptomics approach for target selection, and in vitro/in vivo considerations.
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Affiliation(s)
- Minseok Suh
- Department of Nuclear Medicine, Seoul National University College of Medicine, Seoul, 03080 Republic of Korea
- Department of Molecular Medicine and Biopharmaceutical Sciences, Graduate School of Convergence Science and Technology, Seoul National University, Seoul, 03080 Republic of Korea
| | - Dong Soo Lee
- Department of Nuclear Medicine, Seoul National University College of Medicine, Seoul, 03080 Republic of Korea
- Department of Molecular Medicine and Biopharmaceutical Sciences, Graduate School of Convergence Science and Technology, Seoul National University, Seoul, 03080 Republic of Korea
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88
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Plavén-Sigray P, Schain M, Zanderigo F, Rabiner EA, Gunn RN, Ogden RT, Cervenka S. Accuracy and reliability of [ 11C]PBR28 specific binding estimated without the use of a reference region. Neuroimage 2018; 188:102-110. [PMID: 30500425 DOI: 10.1016/j.neuroimage.2018.11.020] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2018] [Revised: 11/06/2018] [Accepted: 11/16/2018] [Indexed: 12/22/2022] Open
Abstract
[11C]PBR28 is a positron emission tomography radioligand used to examine the expression of the 18 kDa translocator protein (TSPO). TSPO is located in glial cells and can function as a marker for immune activation. Since TSPO is expressed throughout the brain, no true reference region exists. For this reason, an arterial input function is required for accurate quantification of [11C]PBR28 binding and the most common outcome measure is the total distribution volume (VT). Notably, VT reflects both specific binding and non-displaceable binding. Therefore, estimates of specific binding, such as binding potential (e.g. BPND) and specific distribution volume (VS) should theoretically be more sensitive to underlying differences in TSPO expression. It is unknown, however, if unbiased and accurate estimates of these outcome measures are obtainable for [11C]PBR28. The Simultaneous Estimation (SIME) method uses time-activity-curves from multiple brain regions with the aim to obtain a brain-wide estimate of the non-displaceable distribution volume (VND), which can subsequently be used to improve the estimation of BPND and VS. In this study we evaluated the accuracy of SIME-derived VND, and the reliability of resulting estimates of specific binding for [11C]PBR28, using a combination of simulation experiments and in vivo studies in healthy humans. The simulation experiments, based on data from 54 unique [11C]PBR28 examinations, showed that VND values estimated using SIME were both precise and accurate. Data from a pharmacological competition challenge (n = 5) showed that SIME provided VND values that were on average 19% lower than those obtained using the Lassen plot, but similar to values obtained using the Likelihood-Estimation of Occupancy technique. Test-retest data (n = 11) showed that SIME-derived VS values exhibited good reliability and precision, while larger variability was observed in SIME-derived BPND values. The results support the use of SIME for quantifying specific binding of [11C]PBR28, and suggest that VS can be used in complement to the conventional outcome measure VT. Additional studies in patient cohorts are warranted.
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Affiliation(s)
- Pontus Plavén-Sigray
- Centre for Psychiatry Research, Department of Clinical Neuroscience, Karolinska Institutet, & Stockholm Health Care Services, Stockholm County Council, Karolinska University Hospital, SE-171 76 Stockholm, Sweden.
| | - Martin Schain
- Neurobiology Research Unit, Copenhagen University Hospital, Copenhagen, Denmark
| | - Francesca Zanderigo
- Department of Psychiatry, Columbia University, New York, NY, USA; Molecular Imaging and Neuropathology Division, New York State Psychiatric Institute, New York, USA
| | | | | | - Roger N Gunn
- Invicro LLC, London, UK; Division of Brain Sciences, Imperial College London, London, UK
| | - R Todd Ogden
- Department of Psychiatry, Columbia University, New York, NY, USA; Molecular Imaging and Neuropathology Division, New York State Psychiatric Institute, New York, USA; Department of Biostatistics, Mailman School of Public Health, Columbia University, New York, USA
| | - Simon Cervenka
- Centre for Psychiatry Research, Department of Clinical Neuroscience, Karolinska Institutet, & Stockholm Health Care Services, Stockholm County Council, Karolinska University Hospital, SE-171 76 Stockholm, Sweden
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89
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Chaney A, Williams SR, Boutin H. In vivo molecular imaging of neuroinflammation in Alzheimer's disease. J Neurochem 2018; 149:438-451. [PMID: 30339715 PMCID: PMC6563454 DOI: 10.1111/jnc.14615] [Citation(s) in RCA: 59] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2018] [Revised: 09/24/2018] [Accepted: 09/27/2018] [Indexed: 12/11/2022]
Abstract
It has become increasingly evident that neuroinflammation plays a critical role in the pathophysiology of Alzheimer's disease (AD) and other neurodegenerative disorders. Increased glial cell activation is consistently reported in both rodent models of AD and in AD patients. Moreover, recent genome wide association studies have revealed multiple genes associated with inflammation and immunity are significantly associated with an increased risk of AD development (e.g. TREM2). Non‐invasive in vivo detection and tracking of neuroinflammation is necessary to enhance our understanding of the contribution of neuroinflammation to the initiation and progression of AD. Importantly, accurate methods of quantifying neuroinflammation may aid early diagnosis and serve as an output for therapeutic monitoring and disease management. This review details current in vivo imaging biomarkers of neuroinflammation being explored and summarizes both pre‐clinical and clinical results from molecular imaging studies investigating the role of neuroinflammation in AD, with a focus on positron emission tomography and magnetic resonance spectroscopy (MRS). ![]()
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Affiliation(s)
- Aisling Chaney
- School of Health Sciences, Division of Informatics, Faculty of Biology, Medicine and Health, Manchester Academic Health Sciences Centre University of Manchester, Manchester, UK.,Wolfson Molecular Imaging Centre, Faculty of Biology, Medicine and Health and Manchester Academic Health Sciences Centre, University of Manchester, Manchester, UK
| | - Steve R Williams
- School of Health Sciences, Division of Informatics, Faculty of Biology, Medicine and Health, Manchester Academic Health Sciences Centre University of Manchester, Manchester, UK
| | - Herve Boutin
- Wolfson Molecular Imaging Centre, Faculty of Biology, Medicine and Health and Manchester Academic Health Sciences Centre, University of Manchester, Manchester, UK.,School of Biological Sciences, Division of Neuroscience and Experimental Psychology, Faculty of Biology, Medicine and Health, Manchester Academic Health Sciences Centre, University of Manchester, Manchester, UK
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90
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Transcriptional regulation of Translocator protein (18 kDa) (TSPO) in microglia requires Pu.1, Ap1 and Sp factors. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2018; 1861:1119-1133. [PMID: 30412797 DOI: 10.1016/j.bbagrm.2018.10.018] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2018] [Revised: 10/12/2018] [Accepted: 10/31/2018] [Indexed: 11/21/2022]
Abstract
Mitochondrial Translocator protein (18 kDa) (TSPO) is strongly expressed in reactive microglia and serves as a therapeutic target for alleviation of neuronal degeneration. However, little is known about TSPO's transcriptional regulation in microglia. The aim of this study was to identify genetic elements and transcription factors required for basal and inducible TSPO expression in microglia. Murine Tspo promoter was cloned into the pGL4.10 luciferase vector and functionally characterized in BV-2 cells. Deletion mutagenesis indicated that -845 bases upstream were sufficient to reconstitute near maximal promoter activity in BV-2. Deletion of -593 to -520 sequences, which harbour an Ap1, Ets.2 and Nkx3.1 site which also serves as a non-canonical binding site for Sp1-family transcription factors, led to a dramatic decrease in both basal and LPS induced promoter activity. Further deletion of -168 to -39 sequences, which contains four GC boxes, also led to a significant decrease in promoter activity. Targeted mutations of Ap1, Ets.2, Nkx3.1/Sp1/3/4 and the GC boxes led to significant decreases in promoter activity. ChIP-qPCR revealed that Pu.1, Ap1, Stat3, Sp1, Sp3 and Sp4 bind to the endogenous Tspo promoter. Notably, binding of these factors, with the exception of Stat3, was significantly enhanced upon LPS treatment. RNAi silencing of Pu.1, cJun, cFos, Sp1, Sp3, Sp4 and Stat3 strongly lowered Tspo promoter activity while Ap1 silencing inhibited LPS induced increase in Tspo protein levels. These findings demonstrate that consensus binding sequences for Ap1, Ets.2, distal as well as proximal Sp1/3/4 sites regulate basal and LPS induced Tspo promoter activity in microglia.
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91
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Zhang XY, Zhang LM, Mi WD, Li YF. Translocator protein ligand, YL-IPA08, attenuates lipopolysaccharide-induced depression-like behavior by promoting neural regeneration. Neural Regen Res 2018; 13:1937-1944. [PMID: 30233067 PMCID: PMC6183040 DOI: 10.4103/1673-5374.239442] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/11/2018] [Indexed: 11/14/2022] Open
Abstract
Translocator protein has received attention for its involvement in the pathogenesis of depression. This study assessed the effects of the new translocator protein ligand, YL-IPA08, on alleviating inflammation-induced depression-like behavior in mice and investigated its mechanism of action. Mice were intracerebroventricularly injected with 1, 10, 100 or 1000 ng lipopolysaccharide. The tail-suspension test and the forced swimming test confirmed that 100 ng lipopolysaccharide induced depression-like behavior. A mouse model was then established by intraventricular injection of 100 ng lipopolysaccharide. On days 16-24 after model establishment, mice were intragastrically administered 3 mg/kg YL-IPA08 daily. Immunohistochemistry was used to determine BrdU and NeuN expression in the hippocampus. YL-IPA08 effectively reversed the depression-like behavior of lipopolysaccharide-treated mice, restored body mass, increased the number of BrdU-positive cells, and the number and proportion of BrdU and NeuN double-positive cells. These findings indicate that YL-IPA08 can attenuate lipopolysaccharide-induced depression-like behavior in mice by promoting the formation of hippocampal neurons.
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Affiliation(s)
- Xiao-Ying Zhang
- Anesthesia and Operation Center, Chinese PLA General Hospital, Beijing, China
- State Key Laboratory of Toxicology and Medical Countermeasures, Beijing, China
| | - Li-Ming Zhang
- Anesthesia and Operation Center, Chinese PLA General Hospital, Beijing, China
| | - Wei-Dong Mi
- State Key Laboratory of Toxicology and Medical Countermeasures, Beijing, China
| | - Yun-Feng Li
- Anesthesia and Operation Center, Chinese PLA General Hospital, Beijing, China
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92
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Huang S, Li C, Guo J, Zhang L, Wu S, Wang H, Liang S. Monitoring the Progression of Chronic Liver Damage in Rats Using [18F]PBR06. Mol Imaging Biol 2018; 21:669-675. [DOI: 10.1007/s11307-018-1282-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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93
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Singh A, Kendall SL, Campanella M. Common Traits Spark the Mitophagy/Xenophagy Interplay. Front Physiol 2018; 9:1172. [PMID: 30294276 PMCID: PMC6158333 DOI: 10.3389/fphys.2018.01172] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2018] [Accepted: 08/03/2018] [Indexed: 12/16/2022] Open
Abstract
Selective autophagy contributes to the wellbeing of eukaryotic cells by recycling cellular components, disposing damaged organelles, and removing pathogens, amongst others. Both the quality control process of selective mitochondrial autophagy (Mitophagy) and the defensive process of intracellular pathogen-engulfment (Xenophagy) are facilitated via protein assemblies which have shared molecules, a prime example being the Tank-Binding Kinase 1 (TBK1). TBK1 plays a central role in the immunity response driven by Xenophagy and was recently shown to be an amplifying mechanism in Mitophagy, bring to attention the potential cross talk between the two processes. Here we draw parallels between Xenophagy and Mitophagy, speculating on the inhibitory mechanisms of specific proteins (e.g., the 18 kDa protein TSPO), how the preferential sequestering toward one of the two pathways may undermine the other, and in this way impair cellular response to pathogens and cellular immunity. We believe that an in depth understanding of the commonalities may present an opportunity to design novel therapeutic strategies targeted at both the autonomous and non-autonomous processes of selective autophagy.
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Affiliation(s)
- Aarti Singh
- Department of Comparative Biomedical Sciences, Royal Veterinary College, London, United Kingdom
| | - Sharon L Kendall
- Department of Pathology and Pathogen Biology, Royal Veterinary College, Hertfordshire, United Kingdom
| | - Michelangelo Campanella
- Department of Comparative Biomedical Sciences, Royal Veterinary College, London, United Kingdom.,UCL Consortium for Mitochondrial Research, London, United Kingdom
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94
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Betlazar C, Harrison-Brown M, Middleton RJ, Banati R, Liu GJ. Cellular Sources and Regional Variations in the Expression of the Neuroinflammatory Marker Translocator Protein (TSPO) in the Normal Brain. Int J Mol Sci 2018; 19:ijms19092707. [PMID: 30208620 PMCID: PMC6163555 DOI: 10.3390/ijms19092707] [Citation(s) in RCA: 75] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2018] [Revised: 09/09/2018] [Accepted: 09/09/2018] [Indexed: 02/07/2023] Open
Abstract
The inducible expression of the mitochondrial translocator protein 18 kDa (TSPO) by activated microglia is a prominent, regular feature of acute and chronic-progressive brain pathology. This expression is also the rationale for the continual development of new TSPO binding molecules for the diagnosis of "neuroinflammation" by molecular imaging. However, there is in the normal brain an ill-defined, low-level constitutive expression of TSPO. Taking advantage of healthy TSPO knockout mouse brain tissue to validate TSPO antibody specificity, this study uses immunohistochemistry to determine the regional distribution and cellular sources of TSPO in the normal mouse brain. Fluorescence microscopy revealed punctate TSPO immunostaining in vascular endothelial cells throughout the brain. In the olfactory nerve layers and glomeruli of the olfactory bulb, choroid plexus and ependymal layers, we confirm constitutive TSPO expression levels similar to peripheral organs, while some low TSPO expression is present in regions of known neurogenesis, as well as cerebellar Purkinje cells. The distributed-sparse expression of TSPO in endothelial mitochondria throughout the normal brain can be expected to give rise to a low baseline signal in TSPO molecular imaging studies. Finally, our study emphasises the need for valid and methodologically robust verification of the selectivity of TSPO ligands through the use of TSPO knockout tissues.
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Affiliation(s)
- Calina Betlazar
- Australian Nuclear Science and Technology Organisation, New Illawarra Road, Lucas Heights, NSW 2234, Australia.
- Discipline of Medical Imaging & Radiation Sciences, Faculty of Medicine and Health, Brain and Mind Centre, University of Sydney, 94 Mallett Street, Camperdown, NSW 2050, Australia.
| | - Meredith Harrison-Brown
- Australian Nuclear Science and Technology Organisation, New Illawarra Road, Lucas Heights, NSW 2234, Australia.
- Discipline of Medical Imaging & Radiation Sciences, Faculty of Medicine and Health, Brain and Mind Centre, University of Sydney, 94 Mallett Street, Camperdown, NSW 2050, Australia.
| | - Ryan J Middleton
- Australian Nuclear Science and Technology Organisation, New Illawarra Road, Lucas Heights, NSW 2234, Australia.
| | - Richard Banati
- Australian Nuclear Science and Technology Organisation, New Illawarra Road, Lucas Heights, NSW 2234, Australia.
- Discipline of Medical Imaging & Radiation Sciences, Faculty of Medicine and Health, Brain and Mind Centre, University of Sydney, 94 Mallett Street, Camperdown, NSW 2050, Australia.
| | - Guo-Jun Liu
- Australian Nuclear Science and Technology Organisation, New Illawarra Road, Lucas Heights, NSW 2234, Australia.
- Discipline of Medical Imaging & Radiation Sciences, Faculty of Medicine and Health, Brain and Mind Centre, University of Sydney, 94 Mallett Street, Camperdown, NSW 2050, Australia.
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95
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Högel H, Rissanen E, Vuorimaa A, Airas L. Positron emission tomography imaging in evaluation of MS pathology in vivo. Mult Scler 2018; 24:1399-1412. [DOI: 10.1177/1352458518791680] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Positron emission tomography (PET) gives an opportunity to quantitate the expression of specific molecular targets in vivo and longitudinally in brain and thus enhances our possibilities to understand and follow up multiple sclerosis (MS)-related pathology. For successful PET imaging, one needs a relevant target molecule within the brain, to which a blood–brain barrier–penetrating specific radioligand will bind. 18-kDa translocator protein (TSPO)-binding radioligands have been used to detect activated microglial cells at different stages of MS, and remyelination has been measured using amyloid PET. Several PET ligands for the detection of other inflammatory targets, besides TSPO, have been developed but not yet been used for imaging MS patients. Finally, synaptic density evaluation has been successfully tested in human subjects and gives opportunities for the evaluation of the development of cortical and deep gray matter pathology in MS. This review will discuss PET imaging modalities relevant for MS today.
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Affiliation(s)
- Heidi Högel
- Turku PET Centre, Turku University Hospital and University of Turku, Turku, Finland/Division of Clinical Neurosciences, Turku University Hospital and University of Turku, Turku, Finland
| | - Eero Rissanen
- Turku PET Centre, Turku University Hospital and University of Turku, Turku, Finland/Division of Clinical Neurosciences, Turku University Hospital and University of Turku, Turku, Finland
| | - Anna Vuorimaa
- Turku PET Centre, Turku University Hospital and University of Turku, Turku, Finland/Division of Clinical Neurosciences, Turku University Hospital and University of Turku, Turku, Finland
| | - Laura Airas
- Turku PET Centre, Turku University Hospital and University of Turku, Turku, Finland/Division of Clinical Neurosciences, Turku University Hospital and University of Turku, Turku, Finland
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96
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97
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Bhoola NH, Mbita Z, Hull R, Dlamini Z. Translocator Protein (TSPO) as a Potential Biomarker in Human Cancers. Int J Mol Sci 2018; 19:ijms19082176. [PMID: 30044440 PMCID: PMC6121633 DOI: 10.3390/ijms19082176] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2018] [Revised: 06/21/2018] [Accepted: 06/24/2018] [Indexed: 11/17/2022] Open
Abstract
TSPO is a receptor involved in the regulation of cellular proliferation, apoptosis and mitochondrial functions. Previous studies showed that the expression of TSPO protein correlated positively with tumour malignancy and negatively with patient survival. The aim of this study was to determine the transcription of Tspo mRNA in various types of normal and cancer tissues. In situ hybridization was performed to localise the Tspo mRNA in various human normal and cancer tissues. The relative level of Tspo mRNA was quantified using fluorescent intensity and visual estimation of colorimetric staining. RT-PCR was used to confirm these mRNA levels in normal lung, lung cancer, liver cancer, and cervical cancer cell lines. There was a significant increase in the level of transcription in liver, prostate, kidney, and brain cancers while a significant decrease was observed in cancers of the colon and lung. Quantitative RT-PCR confirmed that the mRNA levels of Tspo are higher in a normal lung cell line than in a lung cancer cell line. An increase in the expression levels of Tspo mRNA is not necessarily a good diagnostic biomarker in most cancers with changes not being large enough to be significantly different when detected by in situ hybridisation.
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Affiliation(s)
- Nimisha H Bhoola
- Faculty of Health Sciences, University of the Witwatersrand, Johannesburg 2193, South Africa.
| | - Zukile Mbita
- Department of Biochemistry, Microbiology and Biotechnology, University of Limpopo, Private Bag X1106, Sovenga 0727, South Africa.
| | - Rodney Hull
- Research, Innovation & Engagements Portfolio, Mangosuthu University of Technology, Durban 4031, South Africa.
| | - Zodwa Dlamini
- Research, Innovation & Engagements Portfolio, Mangosuthu University of Technology, Durban 4031, South Africa.
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98
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Pantaleão L, Rocha GHO, Reutelingsperger C, Tiago M, Maria-Engler SS, Solito E, Farsky SP. Connections of annexin A1 and translocator protein-18 kDa on toll like receptor stimulated BV-2 cells. Exp Cell Res 2018; 367:282-290. [DOI: 10.1016/j.yexcr.2018.04.008] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2017] [Revised: 04/06/2018] [Accepted: 04/07/2018] [Indexed: 01/27/2023]
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99
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Translocator protein (18kDa TSPO) binding, a marker of microglia, is reduced in major depression during cognitive-behavioral therapy. Prog Neuropsychopharmacol Biol Psychiatry 2018; 83:1-7. [PMID: 29269262 DOI: 10.1016/j.pnpbp.2017.12.011] [Citation(s) in RCA: 64] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/18/2017] [Revised: 11/27/2017] [Accepted: 12/18/2017] [Indexed: 12/27/2022]
Abstract
Prior studies indicated that neuroinflammation might play a role in the pathophysiology of major depressive disorder (MDD). The purpose of this study was to examine changes in a microglial marker in the brain of patients with MDD during cognitive-behavioral therapy (CBT) and supportive psychotherapy (SPT). Participants were newly diagnosed patients with MDD receiving CBT (n=20) or SPT (n=20) who were compared with 20 healthy control subjects. We used [18F]-FEPPA positron emission tomography (PET) to examine translocator protein total distribution volume (TSPO VT), a marker of microglial density and inflammation. Patients were scanned before and after CBT and SPT. Before therapy, TSPO VT was significantly elevated in neocortical grey matter, frontal cortex, temporal cortex, and hippocampus in MDD relative to the control subjects. In the CBT group, but not in the SPT group, TSPO VT was significantly reduced during the treatment period. Reductions in TSPO VT were correlated with the amelioration of depressive symptoms. This correlation was consistent in the hippocampus in both CBT and SPT groups. In conclusion, CBT, when it reduced symptoms, also decreased TSPO VT. Efficient psychosocial interventions were accompanied by the normalization of a glial marker in the brain of patients with MDD, which may indicate reduced pro-inflammatory activity.
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100
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Koumine Attenuates Neuroglia Activation and Inflammatory Response to Neuropathic Pain. Neural Plast 2018; 2018:9347696. [PMID: 29770147 PMCID: PMC5889871 DOI: 10.1155/2018/9347696] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2017] [Revised: 10/24/2017] [Accepted: 02/13/2018] [Indexed: 01/12/2023] Open
Abstract
Despite decades of studies, the currently available drugs largely fail to control neuropathic pain. Koumine—an alkaloidal constituent derived from the medicinal plant Gelsemium elegans Benth.—has been shown to possess analgesic and anti-inflammatory properties; however, the underlying mechanisms remain unclear. In this study, we aimed to investigate the analgesic and anti-inflammatory effects and the possible underlying mechanisms of koumine. The analgesic and anti-inflammatory effects of koumine were explored by using chronic constriction injury of the sciatic nerve (CCI) neuropathic pain model in vivo and LPS-induced injury in microglia BV2 cells in vitro. Immunofluorescence staining and Western blot analysis were used to assess the modulator effect of koumine on microglia and astrocyte activation after CCI surgery. Enzyme-linked immunosorbent assay (ELISA) was used to evaluate the levels of proinflammatory cytokines. Western blot analysis and quantitative real-time polymerase chain reaction (qPCR) were used to examine the modulator effect of koumine on microglial M1 polarization. We found that single or repeated treatment of koumine can significantly reduce neuropathic pain after nerve injury. Moreover, koumine showed inhibitory effects on CCI-evoked microglia and astrocyte activation and reduced proinflammatory cytokine production in the spinal cord in rat CCI models. In BV2 cells, koumine significantly inhibited microglia M1 polarization. Furthermore, the analgesic effect of koumine was inhibited by a TSPO antagonist PK11195. These findings suggest that the analgesic effects of koumine on CCI-induced neuropathic pain may result from the inhibition of microglia activation and M1 polarization as well as the activation of astrocytes while sparing the anti-inflammatory responses to neuropathic pain.
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