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Brier LM, Chen S, Sherafati A, Bice AR, Lee JM, Culver JP. Transient disruption of functional connectivity and depression of neural fluctuations in a mouse model of acute septic encephalopathy. Cereb Cortex 2023; 33:3548-3561. [PMID: 35972424 PMCID: PMC10068285 DOI: 10.1093/cercor/bhac291] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2022] [Revised: 07/05/2022] [Accepted: 07/07/2022] [Indexed: 11/13/2022] Open
Abstract
Septic encephalopathy leads to major and costly burdens for a large percentage of admitted hospital patients. Elderly patients are at an increased risk, especially those with dementia. Current treatments are aimed at sedation to combat mental status changes and are not aimed at the underlying cause of encephalopathy. Indeed, the underlying pathology linking together peripheral infection and altered neural function has not been established, largely because good, acutely accessible readouts of encephalopathy in animal models do not exist. Behavioral testing in animals lasts multiple days, outlasting the time frame of acute encephalopathy. Here, we propose optical fluorescent imaging of neural functional connectivity (FC) as a readout of encephalopathy in a mouse model of acute sepsis. Imaging and basic behavioral assessment were performed at baseline, Hr8, Hr24, and Hr72 following injection of either lipopolysaccharide or phosphate buffered saline. Neural FC strength decreased at Hr8 and returned to baseline by Hr72 in motor, somatosensory, parietal, and visual cortical regions. Additionally, neural fluctuations transiently declined at Hr8 and returned to baseline by Hr72. Both FC strength and fluctuation tone correlated with neuroscore indicating this imaging methodology is a sensitive and acute readout of encephalopathy.
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Affiliation(s)
- L M Brier
- Department of Radiology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - S Chen
- Department of Radiology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - A Sherafati
- Department of Physics, Washington University School of Arts and Science, St. Louis, MO 63110, USA
| | - A R Bice
- Department of Radiology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - J M Lee
- Department of Neurology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - J P Culver
- Department of Radiology, Washington University School of Medicine, St. Louis, MO 63110, USA
- Department of Physics, Washington University School of Arts and Science, St. Louis, MO 63110, USA
- Department of Biomedical Engineering, Washington University School of Engineering, St. Louis, MO 63110, USA
- Department of Electrical and Systems Engineering, Washington University School of Engineering, St. Louis, MO 63110, USA
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2
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Jimenez IA, Stilin AP, Morohaku K, Hussein MH, Koganti PP, Selvaraj V. Mitochondrial translocator protein deficiency exacerbates pathology in acute experimental ulcerative colitis. Front Physiol 2022; 13:896951. [PMID: 36060674 PMCID: PMC9437295 DOI: 10.3389/fphys.2022.896951] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Accepted: 07/26/2022] [Indexed: 11/13/2022] Open
Abstract
In human patients and animal models of ulcerative colitis (UC), upregulation of the mitochondrial translocator protein (TSPO) in the colon is consistent with inflammation. Although the molecular function for TSPO remains unclear, it has been investigated as a therapeutic target for ameliorating UC pathology. In this study, we examined the susceptibility of Tspo gene-deleted (Tspo -/- ) mice to insults as provided by the dextran sodium sulfate (DSS)-induced acute UC model. Our results show that UC clinical signs and pathology were severely exacerbated in Tspo -/- mice compared to control Tspo fl/fl cohorts. Histopathology showed extensive inflammation and epithelial loss in Tspo -/- mice that caused an aggravated disease. Colonic gene expression in UC uncovered an etiology linked to precipitous loss of epithelial integrity and disproportionate mast cell activation assessed by tryptase levels in Tspo -/- colons. Evaluation of baseline homeostatic shifts in Tspo -/- colons revealed gene expression changes noted in elevated epithelial Cdx2, mast cell Cd36 and Mcp6, with general indicators of lower proliferation capacity and elevated mitochondrial fatty acid oxidation. These findings demonstrate that intact physiological TSPO function serves to limit inflammation in acute UC, and provide a systemic basis for investigating TSPO-targeting mechanistic therapeutics.
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Affiliation(s)
- Isabel A. Jimenez
- Department of Animal Science, College of Agriculture and Life Sciences, Cornell University, Ithaca, NY, United States,Department of Molecular and Comparative Pathobiology, The Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Allison P. Stilin
- Department of Animal Science, College of Agriculture and Life Sciences, Cornell University, Ithaca, NY, United States
| | - Kanako Morohaku
- Department of Animal Science, College of Agriculture and Life Sciences, Cornell University, Ithaca, NY, United States,School of Science and Technology, Institute of Agriculture, Shinshu University, Nagano, Japan
| | - Mahmoud H. Hussein
- Department of Animal Science, College of Agriculture and Life Sciences, Cornell University, Ithaca, NY, United States
| | - Prasanthi P. Koganti
- Department of Animal Science, College of Agriculture and Life Sciences, Cornell University, Ithaca, NY, United States
| | - Vimal Selvaraj
- Department of Animal Science, College of Agriculture and Life Sciences, Cornell University, Ithaca, NY, United States,*Correspondence: Vimal Selvaraj,
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Misin O, Matilainen M, Nylund M, Honkonen E, Rissanen E, Sucksdorff M, Airas L. Innate Immune Cell–Related Pathology in the Thalamus Signals a Risk for Disability Progression in Multiple Sclerosis. NEUROLOGY - NEUROIMMUNOLOGY NEUROINFLAMMATION 2022; 9:9/4/e1182. [PMID: 35581004 PMCID: PMC9128041 DOI: 10.1212/nxi.0000000000001182] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Accepted: 03/17/2022] [Indexed: 11/16/2022]
Abstract
Background and Objectives Our aim was to investigate whether 18-kDa translocator protein (TSPO) radioligand binding in gray matter (GM) predicts later disability progression in multiple sclerosis (MS). Methods In this prospective imaging study, innate immune cells were investigated in the MS patient brain using PET imaging. The distribution volume ratio (DVR) of the TSPO-binding radioligand [11C]PK11195 was determined in 5 GM regions: thalamus, caudate, putamen, pallidum, and cortical GM. Volumetric brain MRI parameters were obtained for comparison. The Expanded Disability Status Scale (EDSS) score was assessed at baseline and after follow-up of 3.0 ± 0.3 (mean ± SD) years. Disability progression was defined as an EDSS score increase of 1.0 point or 0.5 point if the baseline EDSS score was ≥6.0. A forward-type stepwise logistic regression model was constructed to compare multiple imaging and clinical variables in their ability to predict later disability progression. Results The cohort consisted of 66 patients with MS and 18 healthy controls. Patients with later disability progression (n = 17) had more advanced atrophy in the thalamus, caudate, and putamen at baseline compared with patients with no subsequent worsening. TSPO binding was significantly higher in the thalamus among the patients with later worsening. The thalamic DVR was the only measured imaging variable that remained a significant predictor of disability progression in the regression model. The final model predicted disability progression with 52.9% sensitivity and 93.9% specificity with an area under the curve value of 0.82 (receiver operating characteristic curve). Discussion Increased TSPO radioligand binding in the thalamus has potential in predicting short-term disability progression in MS and seems to be more sensitive for this than GM atrophy measures.
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The pandemic brain: Neuroinflammation in non-infected individuals during the COVID-19 pandemic. Brain Behav Immun 2022; 102:89-97. [PMID: 35181440 PMCID: PMC8847082 DOI: 10.1016/j.bbi.2022.02.018] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Revised: 02/07/2022] [Accepted: 02/13/2022] [Indexed: 01/25/2023] Open
Abstract
While COVID-19 research has seen an explosion in the literature, the impact of pandemic-related societal and lifestyle disruptions on brain health among the uninfected remains underexplored. However, a global increase in the prevalence of fatigue, brain fog, depression and other "sickness behavior"-like symptoms implicates a possible dysregulation in neuroimmune mechanisms even among those never infected by the virus. We compared fifty-seven 'Pre-Pandemic' and fifteen 'Pandemic' datasets from individuals originally enrolled as control subjects for various completed, or ongoing, research studies available in our records, with a confirmed negative test for SARS-CoV-2 antibodies. We used a combination of multimodal molecular brain imaging (simultaneous positron emission tomography / magnetic resonance spectroscopy), behavioral measurements, imaging transcriptomics and serum testing to uncover links between pandemic-related stressors and neuroinflammation. Healthy individuals examined after the enforcement of 2020 lockdown/stay-at-home measures demonstrated elevated brain levels of two independent neuroinflammatory markers (the 18 kDa translocator protein, TSPO, and myoinositol) compared to pre-lockdown subjects. The serum levels of two inflammatory markers (interleukin-16 and monocyte chemoattractant protein-1) were also elevated, although these effects did not reach statistical significance after correcting for multiple comparisons. Subjects endorsing higher symptom burden showed higher TSPO signal in the hippocampus (mood alteration, mental fatigue), intraparietal sulcus and precuneus (physical fatigue), compared to those reporting little/no symptoms. Post-lockdown TSPO signal changes were spatially aligned with the constitutive expression of several genes involved in immune/neuroimmune functions. This work implicates neuroimmune activation as a possible mechanism underlying the non-virally-mediated symptoms experienced by many during the COVID-19 pandemic. Future studies will be needed to corroborate and further interpret these preliminary findings.
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Abstract
In the field of neuropsychiatry, neuroinflammation is one of the prevailing hypotheses to explain the pathophysiology of mood and psychotic disorders. Neuroinflammation encompasses an ill-defined set of pathophysiological processes in the central nervous system that cause neuronal or glial atrophy or death and disruptions in neurotransmitter signaling, resulting in cognitive and behavioral changes. Positron emission tomography for the brain-based translocator protein has been shown to be a useful tool to measure glial activation in neuropsychiatric disorders. Recent neuroimaging studies also indicate a potential disruption in the choroid plexus and blood-brain barrier, which modulate the transfer of ions, molecules, toxins, and cells from the periphery into the brain. Simultaneously, peripheral inflammatory markers have consistently been shown to be altered in mood and psychotic disorders. The crosstalk (i.e., the communication between peripheral and central inflammatory pathways) is not well understood in these disorders, however, and neuroimaging studies hold promise to shed light on this complex process. In the current Perspectives article, we discuss the neuroimaging insights into neuroimmune crosstalk offered in selected works. Overall, evidence exists for peripheral immune cell infiltration into the central nervous system in some patients, but the reason for this is unknown. Future neuroimaging studies should aim to extend our knowledge of this system and the role it likely plays in symptom onset and recurrence.
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Chen Z, Haider A, Chen J, Xiao Z, Gobbi L, Honer M, Grether U, Arnold SE, Josephson L, Liang SH. The Repertoire of Small-Molecule PET Probes for Neuroinflammation Imaging: Challenges and Opportunities beyond TSPO. J Med Chem 2021; 64:17656-17689. [PMID: 34905377 PMCID: PMC9094091 DOI: 10.1021/acs.jmedchem.1c01571] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Neuroinflammation is an adaptive response of the central nervous system to diverse potentially injurious stimuli, which is closely associated with neurodegeneration and typically characterized by activation of microglia and astrocytes. As a noninvasive and translational molecular imaging tool, positron emission tomography (PET) could provide a better understanding of neuroinflammation and its role in neurodegenerative diseases. Ligands to translator protein (TSPO), a putative marker of neuroinflammation, have been the most commonly studied in this context, but they suffer from serious limitations. Herein we present a repertoire of different structural chemotypes and novel PET ligand design for classical and emerging neuroinflammatory targets beyond TSPO. We believe that this Perspective will support multidisciplinary collaborations in academic and industrial institutions working on neuroinflammation and facilitate the progress of neuroinflammation PET probe development for clinical use.
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Affiliation(s)
- Zhen Chen
- Division of Nuclear Medicine and Molecular Imaging, Massachusetts General Hospital & Department of Radiology, Harvard Medical School, Boston, MA, 02114, United States
| | - Ahmed Haider
- Division of Nuclear Medicine and Molecular Imaging, Massachusetts General Hospital & Department of Radiology, Harvard Medical School, Boston, MA, 02114, United States
| | - Jiahui Chen
- Division of Nuclear Medicine and Molecular Imaging, Massachusetts General Hospital & Department of Radiology, Harvard Medical School, Boston, MA, 02114, United States
| | - Zhiwei Xiao
- Division of Nuclear Medicine and Molecular Imaging, Massachusetts General Hospital & Department of Radiology, Harvard Medical School, Boston, MA, 02114, United States
| | - Luca Gobbi
- Pharma Research and Early Development, F. Hoffmann-La Roche Ltd, CH-4070 Basel, Switzerland
| | - Michael Honer
- Pharma Research and Early Development, F. Hoffmann-La Roche Ltd, CH-4070 Basel, Switzerland
| | - Uwe Grether
- Pharma Research and Early Development, F. Hoffmann-La Roche Ltd, CH-4070 Basel, Switzerland
| | - Steven E. Arnold
- Department of Neurology and the Massachusetts Alzheimer’s Disease Research Center, Massachusetts General Hospital, Harvard Medical School, 114 16th Street, Charlestown, Massachusetts 02129, USA
| | - Lee Josephson
- Division of Nuclear Medicine and Molecular Imaging, Massachusetts General Hospital & Department of Radiology, Harvard Medical School, Boston, MA, 02114, United States
| | - Steven H. Liang
- Division of Nuclear Medicine and Molecular Imaging, Massachusetts General Hospital & Department of Radiology, Harvard Medical School, Boston, MA, 02114, United States
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Antipsychotics, versatility in action. Proc Natl Acad Sci U S A 2021; 118:2108946118. [PMID: 34244436 DOI: 10.1073/pnas.2108946118] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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Ricigliano VAG, Morena E, Colombi A, Tonietto M, Hamzaoui M, Poirion E, Bottlaender M, Gervais P, Louapre C, Bodini B, Stankoff B. Choroid Plexus Enlargement in Inflammatory Multiple Sclerosis: 3.0-T MRI and Translocator Protein PET Evaluation. Radiology 2021; 301:166-177. [PMID: 34254858 DOI: 10.1148/radiol.2021204426] [Citation(s) in RCA: 63] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Background Choroid plexuses (CPs) have been suggested as a key gateway for inflammation in experimental autoimmune encephalitis, but in vivo evidence of their involvement in multiple sclerosis (MS) is lacking. Purpose To assess CP volumetric and inflammatory changes in patients with MS versus healthy control participants. Materials and Methods This was a secondary analysis of 97 patients (61 with relapsing-remitting MS [RRMS] and 36 with progressive MS) and 44 healthy control participants who participated in three prospective 3.0-T brain MRI studies between May 2009 and September 2017. A subgroup of 37 patients and 19 healthy control participants also underwent translocator protein fluorine 18 (18F)-DPA-714 PET for neuroinflammation. Relapses and disability scores were collected at baseline and over 2 years. CPs were manually segmented on three-dimensional T1-weighted images; other brain volumes were additionally segmented. Volumes were expressed as a ratio of intracranial volume. The 18F-DPA-714 distribution volume ratio was quantified in parenchymal regions, whereas standardized uptake value was used for CP inflammation. Multivariable linear regression analyses were performed to assess CP volumetric and inflammatory differences between patients with MS and healthy control participants and correlations between CP volume and lesion load, brain volumes, 18F-DPA-714 uptake, and annualized relapse rate. Results Ninety-seven patients with MS (mean age, 42 years ± 12 [standard deviation]; 49 women) and 44 healthy control participants (mean age, 39 years ± 14; 23 women) underwent MRI. Thirty-seven patients with MS and 19 healthy control participants underwent PET. CPs were 35% larger in patients with MS (mean value, 15.9 × 10-4 ± 4.5) than in healthy control participants (mean value, 11.8 × 10-4 ± 3.8; P = .004). Subgroup analysis confirmed greater CP volume in patients with RRMS (mean value, 15.5 × 10-4 ± 4.6; P = .008) than in healthy control participants. CP enlargement was greater in patients with active lesions at MRI (mean volume, 18.2 × 10-4 ± 4.9 in patients with lesions that enhanced with gadolinium vs 14.9 × 10-4 ± 4 in patients with lesions that did not enhance with gadolinium; P < .001) and correlated with white matter lesion load (r = 0.39; 95% CI: 0.20, 0.55; P < .001) and 18F-DPA-714 binding in the thalami (r = 0.44; 95% CI: 0.22, 0.72; P = .04) and normal-appearing white matter (r = 0.5; 95% CI: 0.20, 0.71; P = .005). Moreover, it correlated with annualized relapse rate in patients with RRMS (r = 0.37; 95% CI: 0.1, 0.55; P = .005). Finally, patients with MS showed 18.5% higher CP 18F-DPA-714 uptake than control participants (mean value, 0.778 ± 0.23 vs 0.635 ± 0.15, respectively; P = .01). CP volume in patients with RRMS (r = 0.57; 95% CI: 0.37, 0.73; P = .009) correlated with higher 18F-DPA-714 uptake. Conclusion Choroid plexuses (CPs) are enlarged and inflamed in patients with multiple sclerosis (MS), particularly in those with relapsing-remitting MS with inflammatory profiles; CP volumetric analysis could represent an MS imaging marker. © RSNA, 2021 EudraCT no. 2008-004174-40; clinical trial registration nos. NCT02305264 and NCT01651520 Online supplemental material is available for this article.
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Affiliation(s)
- Vito A G Ricigliano
- From the Sorbonne Université, Paris Brain Institute, Institut du Cerveau, Centre National de la Recherche Scientifique, Institut National de la Santé et de la Recherche Médicale, Paris, France (V.A.G.R., E.M., A.C., M.T., M.H., E.P., C.L., B.B., B.S.); Université Paris-Saclay, Commissariat à l'énergie atomique et aux énergies alternatives, Centre National de la Recherche Scientifique, Institut National de la Santé et de la Recherche Médicale, BioMaps, Service Hospitalier Frédéric Joliot, Orsay, France (M.T., M.B., P.G.); Service d'Imagerie Médicale, Hôpital Fondation Adolphe de Rothschild, Paris, France (E.P.); Department of Neurology, Pitié-Salpêtrière Hospital, Assistance Publique des Hôpitaux de Paris, Paris, France (C.L.); and Department of Neurology, St Antoine Hospital, 184, rue du Faubourg St Antoine, Assistance Publique des Hôpitaux de Paris, 75571 Paris, France (B.B., B.S.)
| | - Emanuele Morena
- From the Sorbonne Université, Paris Brain Institute, Institut du Cerveau, Centre National de la Recherche Scientifique, Institut National de la Santé et de la Recherche Médicale, Paris, France (V.A.G.R., E.M., A.C., M.T., M.H., E.P., C.L., B.B., B.S.); Université Paris-Saclay, Commissariat à l'énergie atomique et aux énergies alternatives, Centre National de la Recherche Scientifique, Institut National de la Santé et de la Recherche Médicale, BioMaps, Service Hospitalier Frédéric Joliot, Orsay, France (M.T., M.B., P.G.); Service d'Imagerie Médicale, Hôpital Fondation Adolphe de Rothschild, Paris, France (E.P.); Department of Neurology, Pitié-Salpêtrière Hospital, Assistance Publique des Hôpitaux de Paris, Paris, France (C.L.); and Department of Neurology, St Antoine Hospital, 184, rue du Faubourg St Antoine, Assistance Publique des Hôpitaux de Paris, 75571 Paris, France (B.B., B.S.)
| | - Annalisa Colombi
- From the Sorbonne Université, Paris Brain Institute, Institut du Cerveau, Centre National de la Recherche Scientifique, Institut National de la Santé et de la Recherche Médicale, Paris, France (V.A.G.R., E.M., A.C., M.T., M.H., E.P., C.L., B.B., B.S.); Université Paris-Saclay, Commissariat à l'énergie atomique et aux énergies alternatives, Centre National de la Recherche Scientifique, Institut National de la Santé et de la Recherche Médicale, BioMaps, Service Hospitalier Frédéric Joliot, Orsay, France (M.T., M.B., P.G.); Service d'Imagerie Médicale, Hôpital Fondation Adolphe de Rothschild, Paris, France (E.P.); Department of Neurology, Pitié-Salpêtrière Hospital, Assistance Publique des Hôpitaux de Paris, Paris, France (C.L.); and Department of Neurology, St Antoine Hospital, 184, rue du Faubourg St Antoine, Assistance Publique des Hôpitaux de Paris, 75571 Paris, France (B.B., B.S.)
| | - Matteo Tonietto
- From the Sorbonne Université, Paris Brain Institute, Institut du Cerveau, Centre National de la Recherche Scientifique, Institut National de la Santé et de la Recherche Médicale, Paris, France (V.A.G.R., E.M., A.C., M.T., M.H., E.P., C.L., B.B., B.S.); Université Paris-Saclay, Commissariat à l'énergie atomique et aux énergies alternatives, Centre National de la Recherche Scientifique, Institut National de la Santé et de la Recherche Médicale, BioMaps, Service Hospitalier Frédéric Joliot, Orsay, France (M.T., M.B., P.G.); Service d'Imagerie Médicale, Hôpital Fondation Adolphe de Rothschild, Paris, France (E.P.); Department of Neurology, Pitié-Salpêtrière Hospital, Assistance Publique des Hôpitaux de Paris, Paris, France (C.L.); and Department of Neurology, St Antoine Hospital, 184, rue du Faubourg St Antoine, Assistance Publique des Hôpitaux de Paris, 75571 Paris, France (B.B., B.S.)
| | - Mariem Hamzaoui
- From the Sorbonne Université, Paris Brain Institute, Institut du Cerveau, Centre National de la Recherche Scientifique, Institut National de la Santé et de la Recherche Médicale, Paris, France (V.A.G.R., E.M., A.C., M.T., M.H., E.P., C.L., B.B., B.S.); Université Paris-Saclay, Commissariat à l'énergie atomique et aux énergies alternatives, Centre National de la Recherche Scientifique, Institut National de la Santé et de la Recherche Médicale, BioMaps, Service Hospitalier Frédéric Joliot, Orsay, France (M.T., M.B., P.G.); Service d'Imagerie Médicale, Hôpital Fondation Adolphe de Rothschild, Paris, France (E.P.); Department of Neurology, Pitié-Salpêtrière Hospital, Assistance Publique des Hôpitaux de Paris, Paris, France (C.L.); and Department of Neurology, St Antoine Hospital, 184, rue du Faubourg St Antoine, Assistance Publique des Hôpitaux de Paris, 75571 Paris, France (B.B., B.S.)
| | - Emilie Poirion
- From the Sorbonne Université, Paris Brain Institute, Institut du Cerveau, Centre National de la Recherche Scientifique, Institut National de la Santé et de la Recherche Médicale, Paris, France (V.A.G.R., E.M., A.C., M.T., M.H., E.P., C.L., B.B., B.S.); Université Paris-Saclay, Commissariat à l'énergie atomique et aux énergies alternatives, Centre National de la Recherche Scientifique, Institut National de la Santé et de la Recherche Médicale, BioMaps, Service Hospitalier Frédéric Joliot, Orsay, France (M.T., M.B., P.G.); Service d'Imagerie Médicale, Hôpital Fondation Adolphe de Rothschild, Paris, France (E.P.); Department of Neurology, Pitié-Salpêtrière Hospital, Assistance Publique des Hôpitaux de Paris, Paris, France (C.L.); and Department of Neurology, St Antoine Hospital, 184, rue du Faubourg St Antoine, Assistance Publique des Hôpitaux de Paris, 75571 Paris, France (B.B., B.S.)
| | - Michel Bottlaender
- From the Sorbonne Université, Paris Brain Institute, Institut du Cerveau, Centre National de la Recherche Scientifique, Institut National de la Santé et de la Recherche Médicale, Paris, France (V.A.G.R., E.M., A.C., M.T., M.H., E.P., C.L., B.B., B.S.); Université Paris-Saclay, Commissariat à l'énergie atomique et aux énergies alternatives, Centre National de la Recherche Scientifique, Institut National de la Santé et de la Recherche Médicale, BioMaps, Service Hospitalier Frédéric Joliot, Orsay, France (M.T., M.B., P.G.); Service d'Imagerie Médicale, Hôpital Fondation Adolphe de Rothschild, Paris, France (E.P.); Department of Neurology, Pitié-Salpêtrière Hospital, Assistance Publique des Hôpitaux de Paris, Paris, France (C.L.); and Department of Neurology, St Antoine Hospital, 184, rue du Faubourg St Antoine, Assistance Publique des Hôpitaux de Paris, 75571 Paris, France (B.B., B.S.)
| | - Philippe Gervais
- From the Sorbonne Université, Paris Brain Institute, Institut du Cerveau, Centre National de la Recherche Scientifique, Institut National de la Santé et de la Recherche Médicale, Paris, France (V.A.G.R., E.M., A.C., M.T., M.H., E.P., C.L., B.B., B.S.); Université Paris-Saclay, Commissariat à l'énergie atomique et aux énergies alternatives, Centre National de la Recherche Scientifique, Institut National de la Santé et de la Recherche Médicale, BioMaps, Service Hospitalier Frédéric Joliot, Orsay, France (M.T., M.B., P.G.); Service d'Imagerie Médicale, Hôpital Fondation Adolphe de Rothschild, Paris, France (E.P.); Department of Neurology, Pitié-Salpêtrière Hospital, Assistance Publique des Hôpitaux de Paris, Paris, France (C.L.); and Department of Neurology, St Antoine Hospital, 184, rue du Faubourg St Antoine, Assistance Publique des Hôpitaux de Paris, 75571 Paris, France (B.B., B.S.)
| | - Céline Louapre
- From the Sorbonne Université, Paris Brain Institute, Institut du Cerveau, Centre National de la Recherche Scientifique, Institut National de la Santé et de la Recherche Médicale, Paris, France (V.A.G.R., E.M., A.C., M.T., M.H., E.P., C.L., B.B., B.S.); Université Paris-Saclay, Commissariat à l'énergie atomique et aux énergies alternatives, Centre National de la Recherche Scientifique, Institut National de la Santé et de la Recherche Médicale, BioMaps, Service Hospitalier Frédéric Joliot, Orsay, France (M.T., M.B., P.G.); Service d'Imagerie Médicale, Hôpital Fondation Adolphe de Rothschild, Paris, France (E.P.); Department of Neurology, Pitié-Salpêtrière Hospital, Assistance Publique des Hôpitaux de Paris, Paris, France (C.L.); and Department of Neurology, St Antoine Hospital, 184, rue du Faubourg St Antoine, Assistance Publique des Hôpitaux de Paris, 75571 Paris, France (B.B., B.S.)
| | - Benedetta Bodini
- From the Sorbonne Université, Paris Brain Institute, Institut du Cerveau, Centre National de la Recherche Scientifique, Institut National de la Santé et de la Recherche Médicale, Paris, France (V.A.G.R., E.M., A.C., M.T., M.H., E.P., C.L., B.B., B.S.); Université Paris-Saclay, Commissariat à l'énergie atomique et aux énergies alternatives, Centre National de la Recherche Scientifique, Institut National de la Santé et de la Recherche Médicale, BioMaps, Service Hospitalier Frédéric Joliot, Orsay, France (M.T., M.B., P.G.); Service d'Imagerie Médicale, Hôpital Fondation Adolphe de Rothschild, Paris, France (E.P.); Department of Neurology, Pitié-Salpêtrière Hospital, Assistance Publique des Hôpitaux de Paris, Paris, France (C.L.); and Department of Neurology, St Antoine Hospital, 184, rue du Faubourg St Antoine, Assistance Publique des Hôpitaux de Paris, 75571 Paris, France (B.B., B.S.)
| | - Bruno Stankoff
- From the Sorbonne Université, Paris Brain Institute, Institut du Cerveau, Centre National de la Recherche Scientifique, Institut National de la Santé et de la Recherche Médicale, Paris, France (V.A.G.R., E.M., A.C., M.T., M.H., E.P., C.L., B.B., B.S.); Université Paris-Saclay, Commissariat à l'énergie atomique et aux énergies alternatives, Centre National de la Recherche Scientifique, Institut National de la Santé et de la Recherche Médicale, BioMaps, Service Hospitalier Frédéric Joliot, Orsay, France (M.T., M.B., P.G.); Service d'Imagerie Médicale, Hôpital Fondation Adolphe de Rothschild, Paris, France (E.P.); Department of Neurology, Pitié-Salpêtrière Hospital, Assistance Publique des Hôpitaux de Paris, Paris, France (C.L.); and Department of Neurology, St Antoine Hospital, 184, rue du Faubourg St Antoine, Assistance Publique des Hôpitaux de Paris, 75571 Paris, France (B.B., B.S.)
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9
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Proteomics of Multiple Sclerosis: Inherent Issues in Defining the Pathoetiology and Identifying (Early) Biomarkers. Int J Mol Sci 2021; 22:ijms22147377. [PMID: 34298997 PMCID: PMC8306353 DOI: 10.3390/ijms22147377] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2021] [Revised: 06/25/2021] [Accepted: 06/29/2021] [Indexed: 02/06/2023] Open
Abstract
Multiple Sclerosis (MS) is a demyelinating disease of the human central nervous system having an unconfirmed pathoetiology. Although animal models are used to mimic the pathology and clinical symptoms, no single model successfully replicates the full complexity of MS from its initial clinical identification through disease progression. Most importantly, a lack of preclinical biomarkers is hampering the earliest possible diagnosis and treatment. Notably, the development of rationally targeted therapeutics enabling pre-emptive treatment to halt the disease is also delayed without such biomarkers. Using literature mining and bioinformatic analyses, this review assessed the available proteomic studies of MS patients and animal models to discern (1) whether the models effectively mimic MS; and (2) whether reasonable biomarker candidates have been identified. The implication and necessity of assessing proteoforms and the critical importance of this to identifying rational biomarkers are discussed. Moreover, the challenges of using different proteomic analytical approaches and biological samples are also addressed.
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10
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Shen J, Yang B, Xie Z, Wu H, Zheng Z, Wang J, Wang P, Zhang P, Li W, Ye Z, Yu C. Cell-Type-Specific Gene Modules Related to the Regional Homogeneity of Spontaneous Brain Activity and Their Associations With Common Brain Disorders. Front Neurosci 2021; 15:639527. [PMID: 33958982 PMCID: PMC8093778 DOI: 10.3389/fnins.2021.639527] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Accepted: 03/25/2021] [Indexed: 12/13/2022] Open
Abstract
Mapping gene expression profiles to neuroimaging phenotypes in the same anatomical space provides opportunities to discover molecular substrates for human brain functional properties. Here, we aimed to identify cell-type-specific gene modules associated with the regional homogeneity (ReHo) of spontaneous brain activity and their associations with brain disorders. Fourteen gene modules were consistently associated with ReHo in the three datasets, five of which showed cell-type-specific expression (one neuron-endothelial module, one neuron module, one astrocyte module and two microglial modules) in two independent cell series of the human cerebral cortex. The neuron-endothelial module was mainly enriched for transporter complexes, the neuron module for the synaptic membrane, the astrocyte module for amino acid metabolism, and microglial modules for leukocyte activation and ribose phosphate biosynthesis. In enrichment analyses of cell-type-specific modules for 10 common brain disorders, only the microglial module was significantly enriched for genes obtained from genome-wide association studies of multiple sclerosis (MS) and Alzheimer’s disease (AD). The ReHo of spontaneous brain activity is associated with the gene expression profiles of neurons, astrocytes, microglia and endothelial cells. The microglia-related genes associated with MS and AD may provide possible molecular substrates for ReHo abnormality in both brain disorders.
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Affiliation(s)
- Junlin Shen
- Department of Radiology and Tianjin Key Laboratory of Functional Imaging, Tianjin Medical University General Hospital, Tianjin, China
| | - Bingbing Yang
- Department of Radiology and Tianjin Key Laboratory of Functional Imaging, Tianjin Medical University General Hospital, Tianjin, China
| | - Zhonghua Xie
- Department of Mathematics, School of Science, Tianjin University of Science and Technology, Tianjin, China
| | - Heng Wu
- Tianjin Key Laboratory of Lung Cancer Metastasis and Tumor Microenvironment, Tianjin Lung Cancer Institute, Tianjin Medical University General Hospital, Tianjin, China
| | - Zhanye Zheng
- Department of Pharmacology, School of Basic Medical Science, Tianjin Medical University, Tianjin, China
| | - Jianhua Wang
- Department of Pharmacology, School of Basic Medical Science, Tianjin Medical University, Tianjin, China
| | - Ping Wang
- School of Medical Imaging and Tianjin Key Laboratory of Functional Imaging, Tianjin Medical University, Tianjin, China
| | - Peng Zhang
- Department of Radiology, National Clinical Research Center for Cancer, Tianjin Medical University Cancer Institute and Hospital, Tianjin, China.,Key Laboratory of Cancer Prevention and Therapy, Tianjin, China.,Tianjin's Clinical Research Center for Cancer, Tianjin, China
| | - Wei Li
- Department of Radiology, National Clinical Research Center for Cancer, Tianjin Medical University Cancer Institute and Hospital, Tianjin, China.,Key Laboratory of Cancer Prevention and Therapy, Tianjin, China.,Tianjin's Clinical Research Center for Cancer, Tianjin, China
| | - Zhaoxiang Ye
- Department of Radiology, National Clinical Research Center for Cancer, Tianjin Medical University Cancer Institute and Hospital, Tianjin, China.,Key Laboratory of Cancer Prevention and Therapy, Tianjin, China.,Tianjin's Clinical Research Center for Cancer, Tianjin, China
| | - Chunshui Yu
- Department of Radiology and Tianjin Key Laboratory of Functional Imaging, Tianjin Medical University General Hospital, Tianjin, China
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11
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Immunoregulatory Effects of Tolerogenic Probiotics in Multiple Sclerosis. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2021; 1286:87-105. [PMID: 33725347 DOI: 10.1007/978-3-030-55035-6_6] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Gut microbiota has essential roles in the prevention and progression of multiple sclerosis (MS). The association between the gut microbiota and the central nervous system (CNS) or immune system response of MS patients has been documented in many studies. The composition of the gut microbiota could lead to sensitization or resistance against promotion and development of MS disease. Probiotics are the major part of gut microflorapopulation and could be substituted with tolerogenic probiotics that protect the CNS against autoimmune responses. Tolerogenic probiotics with anti-inflammatory and immuno-modulatory properties have effects on intestinal flora and can reestablish regulatory mucosal and systemic immune responses. Probiotics are able to prevent and restore excessive activation of inflammatory responses, especially autoreactive T cells and inflammatory cytokines. Tolerogenic probiotics, through induction of regulatory T cells and increase of anti-inflammatory cytokines, play a crucial role in controlling inflammation and maintaining tolerance and hemostasis. Therefore, probiotics can be considered as a preventive or therapeutic tool in MS. In the present review, we focus on the immunoregulatory effects of tolerogenic probiotics on the severity of disease, as well as Th1, Th2, and Treg populations in different experimental and human studies of MS.
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12
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Singhal T, Rissanen E, Ficke J, Cicero S, Carter K, Weiner HL. Widespread Glial Activation in Primary Progressive Multiple Sclerosis Revealed by 18F-PBR06 PET: A Clinically Feasible, Individualized Approach. Clin Nucl Med 2021; 46:136-137. [PMID: 33208611 PMCID: PMC7774808 DOI: 10.1097/rlu.0000000000003398] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2020] [Revised: 09/28/2020] [Indexed: 11/25/2022]
Abstract
ABSTRACT A 64-year-old man with primary progressive multiple sclerosis (Expanded Disability Status Scale 3.5) underwent PET using 18F-PBR06, a second-generation 18-kDa translocator protein ligand targeting activated brain microglia and astrocytes. Voxel-by-voxel statistical comparison of patient's PET images (acquired 60-90 minutes postinjection) with a healthy control data set was performed to generate a 3-dimensional z-score map of increased radiotracer uptake, which showed widespread increased glial activation in normal-appearing cerebral white matter, white matter lesional and perilesional areas, brainstem and cerebellum. In contrast, patient's 3-T MRI scan showed only a few small white matter brain lesions without contrast enhancement.
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Affiliation(s)
- Tarun Singhal
- From the PET Imaging Program in Neurologic Diseases
- Partners Multiple Sclerosis Center, Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA
| | | | - John Ficke
- From the PET Imaging Program in Neurologic Diseases
| | | | | | - Howard L. Weiner
- Partners Multiple Sclerosis Center, Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA
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13
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Goud NS, Bhattacharya A, Joshi RK, Nagaraj C, Bharath RD, Kumar P. Carbon-11: Radiochemistry and Target-Based PET Molecular Imaging Applications in Oncology, Cardiology, and Neurology. J Med Chem 2021; 64:1223-1259. [PMID: 33499603 DOI: 10.1021/acs.jmedchem.0c01053] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The positron emission tomography (PET) molecular imaging technique has gained its universal value as a remarkable tool for medical diagnosis and biomedical research. Carbon-11 is one of the promising radiotracers that can report target-specific information related to its pharmacology and physiology to understand the disease status. Currently, many of the available carbon-11 (t1/2 = 20.4 min) PET radiotracers are heterocyclic derivatives that have been synthesized using carbon-11 inserted different functional groups obtained from primary and secondary carbon-11 precursors. A spectrum of carbon-11 PET radiotracers has been developed against many of the upregulated and emerging targets for the diagnosis, prognosis, prediction, and therapy in the fields of oncology, cardiology, and neurology. This review focuses on the carbon-11 radiochemistry and various target-specific PET molecular imaging agents used in tumor, heart, brain, and neuroinflammatory disease imaging along with its associated pathology.
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Affiliation(s)
- Nerella Sridhar Goud
- Department of Neuroimaging and Interventional Radiology (NIIR), National Institute of Mental Health and Neuro Sciences (NIMHANS), Bengaluru 560 029, India
| | - Ahana Bhattacharya
- Department of Neuroimaging and Interventional Radiology (NIIR), National Institute of Mental Health and Neuro Sciences (NIMHANS), Bengaluru 560 029, India
| | - Raman Kumar Joshi
- Department of Neuroimaging and Interventional Radiology (NIIR), National Institute of Mental Health and Neuro Sciences (NIMHANS), Bengaluru 560 029, India
| | - Chandana Nagaraj
- Department of Neuroimaging and Interventional Radiology (NIIR), National Institute of Mental Health and Neuro Sciences (NIMHANS), Bengaluru 560 029, India
| | - Rose Dawn Bharath
- Department of Neuroimaging and Interventional Radiology (NIIR), National Institute of Mental Health and Neuro Sciences (NIMHANS), Bengaluru 560 029, India
| | - Pardeep Kumar
- Department of Neuroimaging and Interventional Radiology (NIIR), National Institute of Mental Health and Neuro Sciences (NIMHANS), Bengaluru 560 029, India
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14
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Barros C, Fernandes A. Linking Cognitive Impairment to Neuroinflammation in Multiple Sclerosis using neuroimaging tools. Mult Scler Relat Disord 2020; 47:102622. [PMID: 33227630 DOI: 10.1016/j.msard.2020.102622] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Revised: 11/08/2020] [Accepted: 11/09/2020] [Indexed: 12/24/2022]
Abstract
Multiple sclerosis (MS) is a complex chronic immune disease in the central nervous system, causing neurological disability among young and middle-aged adults. Impaired cognition is now emerging as a major clinical symptom being present in more than 50% of MS patients. Recent data support that neuroinflammation mediated by glial cells plays a key part in MS course and, particularly, microglia is responsible for the pruning of synapses possibly impacting on vital neural networks maintenance. However, the knowledge of microglia-mediated mechanisms underlying cognitive impairment in MS is poor and unfortunately, there are no medicines to overcome this "invisible" symptom. Interestingly, the use of powerful diagnostic imaging tools as structural and functional MRI as well as PET brought new insights into some biological mechanisms, but no link between the possibility to use early visible alterations to predict cognitive deficits was clarified yet. In this review, we focus on the interplay between MS-related cognitive structures and neuroinflammation, specifically the presence of microglia and their reactivity. Moreover, we also discuss new imaging tools to assess cognitive impairment and to track microglia activation. Understanding the role of microglia in cognitive impairment and how it can be prevented may be a promising contribution to innovative therapeutic strategies that culminate in the improvement of MS patients' life quality.
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Affiliation(s)
- Catarina Barros
- Neuron-Glia Biology in Health and Disease, Research Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy, Universidade de Lisboa, Portugal
| | - Adelaide Fernandes
- Neuron-Glia Biology in Health and Disease, Research Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy, Universidade de Lisboa, Portugal; Department of Biochemistry and Human Biology, Faculty of Pharmacy, Universidade de Lisboa, Portugal.
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15
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Wang Z, Mascarenhas C, Jia X. Positron Emission Tomography After Ischemic Brain Injury: Current Challenges and Future Developments. Transl Stroke Res 2020; 11:628-642. [PMID: 31939060 DOI: 10.1007/s12975-019-00765-0] [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: 08/06/2019] [Revised: 11/22/2019] [Accepted: 12/04/2019] [Indexed: 12/19/2022]
Abstract
Positron emission tomography (PET) is widely used in clinical and animal studies, along with the development of diverse tracers. The biochemical characteristics of PET tracers may help uncover the pathophysiological consequences of cardiac arrest (CA) and ischemic stroke, which include cerebral ischemia and reperfusion, depletion of oxygen and glucose, and neuroinflammation. PubMed was searched for studies of the application of PET for "cardiac arrest," "ischemic stroke," and "targeted temperature management." Available studies were included and classified according to the biochemical properties involved and metabolic processes of PET tracers, and were summarized. The mechanisms of ischemic brain injuries were investigated by PET with various tracers to elucidate the pathological process from the initial decrease of cerebral blood flow (CBF) to the subsequent abnormalities in energy and oxygen metabolism, to the monitoring of inflammation. In general, the trends of cerebral blood flow and oxygen metabolism after ischemic attack are not unidirectional but closely related to the time point of injury and recovery. Glucose metabolism after injury showed significant differences in different brain regions whereas global cerebral metabolic rate of glucose (CMRglc) declined. PET monitoring of neuroinflammation shows comparable efficacy to immunostaining. The technology of PET targeting in brain metabolism and the development of tracers provide new tools to track and evaluate the brain's pathological changes after ischemic brain injury. Despite no existing evidence for an available PET-based prediction method, discoveries of new tracers are expected to provide more possibilities for the whole field.
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Affiliation(s)
- Zhuoran Wang
- Department of Critical Care Medicine, Zhongnan Hospital of Wuhan University, Wuhan, 43007, China.,Department of Neurosurgery, University of Maryland School of Medicine, 10 South Pine Street, MSTF Building 823, Baltimore, MD, 21201, USA
| | - Conrad Mascarenhas
- Department of Neurosurgery, University of Maryland School of Medicine, 10 South Pine Street, MSTF Building 823, Baltimore, MD, 21201, USA
| | - Xiaofeng Jia
- Department of Neurosurgery, University of Maryland School of Medicine, 10 South Pine Street, MSTF Building 823, Baltimore, MD, 21201, USA. .,Department of Orthopedics, University of Maryland School of Medicine, Baltimore, MD, 21201, USA. .,Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, MD, 21201, USA. .,Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA. .,Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA.
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16
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Abstract
Emerging data point to important contributions of both autoimmune inflammation and progressive degeneration in the pathophysiology of multiple sclerosis (MS). Unfortunately, after decades of intensive investigation, the fundamental cause remains unknown. A large body of research on the immunobiology of MS has resulted in a variety of anti-inflammatory therapies that are highly effective at reducing brain inflammation and clinical/radiological relapses. However, despite potent suppression of inflammation, benefit in the more important and disabling progressive phase is extremely limited; thus, progressive MS has emerged as the greatest challenge for the MS research and clinical communities. Data obtained over the years point to a complex interplay between environment (e.g., the near-absolute requirement of Epstein-Barr virus exposure), immunogenetics (strong associations with a large number of immune genes), and an ever more convincing role of an underlying degenerative process resulting in demyelination (in both white and grey matter regions), axonal and neuro-synaptic injury, and a persistent innate inflammatory response with a seemingly diminishing role of T cell-mediated autoimmunity as the disease progresses. Together, these observations point toward a primary degenerative process, one whose cause remains unknown but one that entrains a nearly ubiquitous secondary autoimmune response, as a likely sequence of events underpinning this disease. Here, we briefly review what is known about the potential pathophysiological mechanisms, focus on progressive MS, and discuss the two main hypotheses of MS pathogenesis that are the topic of vigorous debate in the field: whether primary autoimmunity or degeneration lies at the foundation. Unravelling this controversy will be critically important for developing effective new therapies for the most disabling later phases of this disease.
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Affiliation(s)
- Peter K Stys
- Department of Clinical Neurosciences, Hotchkiss Brain Institute, Medicine University of Calgary, Calgary, Alberta, Canada
| | - Shigeki Tsutsui
- Department of Clinical Neurosciences, Hotchkiss Brain Institute, Medicine University of Calgary, Calgary, Alberta, Canada
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17
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Sucksdorff M, Tuisku J, Matilainen M, Vuorimaa A, Smith S, Keitilä J, Rokka J, Parkkola R, Nylund M, Rinne J, Rissanen E, Airas L. Natalizumab treatment reduces microglial activation in the white matter of the MS brain. NEUROLOGY-NEUROIMMUNOLOGY & NEUROINFLAMMATION 2019; 6:e574. [PMID: 31355310 PMCID: PMC6624093 DOI: 10.1212/nxi.0000000000000574] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/19/2018] [Accepted: 04/02/2019] [Indexed: 01/31/2023]
Abstract
Objective To evaluate whether natalizumab treatment reduces microglial activation in MS. Methods We measured microglial activation using the 18-kDa translocator protein (TSPO)-binding radioligand [11C]PK11195 and PET imaging in 10 patients with MS before and after 1 year treatment with natalizumab. Microglial activation was evaluated as the distribution volume ratio (DVR) of the specifically bound radioligand in brain white and gray matter regions of interest. MRI and disability measurements were performed for comparison. Evaluation was performed identically with 11 age- and sex-matched patients with MS who had no MS therapy. Results Natalizumab treatment reduced microglial activation in the normal-appearing white matter (NAWM; baseline DVR vs DVR after 1 year of treatment 1.25 vs 1.22, p = 0.014, Wilcoxon) and at the rim of chronic lesions (baseline DVR vs DVR after 1 year of treatment 1.24 vs 1.18, p = 0.014). In patients with MS with no treatment, there was an increase in microglial activation at the rim of chronic lesions (1.23 vs 1.27, p = 0.045). No alteration was observed in microglial activation in gray matter areas. In the untreated patient group, higher microglial activation at baseline was associated with more rapid disability progression during an average of 4 years of follow-up. Conclusions TSPO-PET imaging can be used as a tool to assess longitudinal changes in microglial activation in the NAWM and in the perilesional areas in the MS brain in vivo. Natalizumab treatment reduces the diffuse compartmentalized CNS inflammation related to brain resident innate immune cells.
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Affiliation(s)
- Marcus Sucksdorff
- Turku PET Centre (M.S., J.T., M.M., A.V., S.S., J.K., J. Rokka, M.N., J. Rinne, E.R., L.A.), Turku University Hospital and University of Turku; Division of Clinical Neurosciences (M.S., M.N., J. Rinne, E.R., L.A.), Turku University Hospital and University of Turku; and Department of Radiology (R.P.), University Hospital and University of Turku, Finland
| | - Jouni Tuisku
- Turku PET Centre (M.S., J.T., M.M., A.V., S.S., J.K., J. Rokka, M.N., J. Rinne, E.R., L.A.), Turku University Hospital and University of Turku; Division of Clinical Neurosciences (M.S., M.N., J. Rinne, E.R., L.A.), Turku University Hospital and University of Turku; and Department of Radiology (R.P.), University Hospital and University of Turku, Finland
| | - Markus Matilainen
- Turku PET Centre (M.S., J.T., M.M., A.V., S.S., J.K., J. Rokka, M.N., J. Rinne, E.R., L.A.), Turku University Hospital and University of Turku; Division of Clinical Neurosciences (M.S., M.N., J. Rinne, E.R., L.A.), Turku University Hospital and University of Turku; and Department of Radiology (R.P.), University Hospital and University of Turku, Finland
| | - Anna Vuorimaa
- Turku PET Centre (M.S., J.T., M.M., A.V., S.S., J.K., J. Rokka, M.N., J. Rinne, E.R., L.A.), Turku University Hospital and University of Turku; Division of Clinical Neurosciences (M.S., M.N., J. Rinne, E.R., L.A.), Turku University Hospital and University of Turku; and Department of Radiology (R.P.), University Hospital and University of Turku, Finland
| | - Sarah Smith
- Turku PET Centre (M.S., J.T., M.M., A.V., S.S., J.K., J. Rokka, M.N., J. Rinne, E.R., L.A.), Turku University Hospital and University of Turku; Division of Clinical Neurosciences (M.S., M.N., J. Rinne, E.R., L.A.), Turku University Hospital and University of Turku; and Department of Radiology (R.P.), University Hospital and University of Turku, Finland
| | - Joonas Keitilä
- Turku PET Centre (M.S., J.T., M.M., A.V., S.S., J.K., J. Rokka, M.N., J. Rinne, E.R., L.A.), Turku University Hospital and University of Turku; Division of Clinical Neurosciences (M.S., M.N., J. Rinne, E.R., L.A.), Turku University Hospital and University of Turku; and Department of Radiology (R.P.), University Hospital and University of Turku, Finland
| | - Johanna Rokka
- Turku PET Centre (M.S., J.T., M.M., A.V., S.S., J.K., J. Rokka, M.N., J. Rinne, E.R., L.A.), Turku University Hospital and University of Turku; Division of Clinical Neurosciences (M.S., M.N., J. Rinne, E.R., L.A.), Turku University Hospital and University of Turku; and Department of Radiology (R.P.), University Hospital and University of Turku, Finland
| | - Riitta Parkkola
- Turku PET Centre (M.S., J.T., M.M., A.V., S.S., J.K., J. Rokka, M.N., J. Rinne, E.R., L.A.), Turku University Hospital and University of Turku; Division of Clinical Neurosciences (M.S., M.N., J. Rinne, E.R., L.A.), Turku University Hospital and University of Turku; and Department of Radiology (R.P.), University Hospital and University of Turku, Finland
| | - Marjo Nylund
- Turku PET Centre (M.S., J.T., M.M., A.V., S.S., J.K., J. Rokka, M.N., J. Rinne, E.R., L.A.), Turku University Hospital and University of Turku; Division of Clinical Neurosciences (M.S., M.N., J. Rinne, E.R., L.A.), Turku University Hospital and University of Turku; and Department of Radiology (R.P.), University Hospital and University of Turku, Finland
| | - Juha Rinne
- Turku PET Centre (M.S., J.T., M.M., A.V., S.S., J.K., J. Rokka, M.N., J. Rinne, E.R., L.A.), Turku University Hospital and University of Turku; Division of Clinical Neurosciences (M.S., M.N., J. Rinne, E.R., L.A.), Turku University Hospital and University of Turku; and Department of Radiology (R.P.), University Hospital and University of Turku, Finland
| | - Eero Rissanen
- Turku PET Centre (M.S., J.T., M.M., A.V., S.S., J.K., J. Rokka, M.N., J. Rinne, E.R., L.A.), Turku University Hospital and University of Turku; Division of Clinical Neurosciences (M.S., M.N., J. Rinne, E.R., L.A.), Turku University Hospital and University of Turku; and Department of Radiology (R.P.), University Hospital and University of Turku, Finland
| | - Laura Airas
- Turku PET Centre (M.S., J.T., M.M., A.V., S.S., J.K., J. Rokka, M.N., J. Rinne, E.R., L.A.), Turku University Hospital and University of Turku; Division of Clinical Neurosciences (M.S., M.N., J. Rinne, E.R., L.A.), Turku University Hospital and University of Turku; and Department of Radiology (R.P.), University Hospital and University of Turku, Finland
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18
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Vainio SK, Dickens AM, Tuisku J, Eskola O, Solin O, Löyttyniemi E, Anthony DC, Rinne JO, Airas L, Haaparanta-Solin M. Cessation of anti-VLA-4 therapy in a focal rat model of multiple sclerosis causes an increase in neuroinflammation. EJNMMI Res 2019; 9:38. [PMID: 31073768 PMCID: PMC6509289 DOI: 10.1186/s13550-019-0508-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2019] [Accepted: 04/15/2019] [Indexed: 11/21/2022] Open
Abstract
Background Positron emission tomography (PET) can be used for in vivo evaluation of the pathology associated with multiple sclerosis. We investigated the use of longitudinal PET imaging and the 18-kDa translocator protein (TSPO) binding radioligand [18F]GE-180 to detect changes in a chronic multiple sclerosis-like focal delayed-type hypersensitivity experimental autoimmune encephalomyelitis (fDTH-EAE) rat model during and after anti-VLA-4 monoclonal antibody (mAb) treatment. Thirty days after lesion activation, fDTH-EAE rats were treated with the anti-VLA-4 mAb (n = 4) or a control mAb (n = 4; 5 mg/kg, every third day, subcutaneously) for 31 days. Animals were imaged with [18F]GE-180 on days 30, 44, 65, 86 and 142. Another group of animals (n = 4) was used for visualisation the microglia with Iba-1 at day 44 after a 2-week treatment period. Results After a 2-week treatment period on day 44, there was a declining trend (p = 0.067) in [18F]GE-180-binding in the anti-VLA-4 mAb-treated animals versus controls. However, cessation of treatment for 4 days after a 31-day treatment period increased [18F]GE-180 binding in animals treated with anti-VLA-4 mAb compared to the control group (p = 0.0003). There was no difference between the groups in TSPO binding by day 142. Conclusions These results demonstrated that cessation of anti-VLA-4 mAb treatment for 4 days caused a transient rebound increase in neuroinflammation. This highlights the usefulness of serial TSPO imaging in the fDTH-EAE model to better understand the rebound phenomenon.
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Affiliation(s)
- S K Vainio
- Turku PET Centre, Preclinical PET Imaging, University of Turku, Tykistökatu 6 A, 20520, Turku, Finland. .,MediCity Research Laboratory, University of Turku, Turku, Finland.
| | - A M Dickens
- Turku Centre for Biotechnology, University of Turku, Turku, Finland.,Department of Pharmacology, University of Oxford, Oxford, UK
| | - J Tuisku
- Turku PET Centre, Clinical Neurology, Turku University Hospital, Turku, Finland
| | - O Eskola
- Turku PET Centre, Radiopharmaceutical Chemistry Laboratory, University of Turku, Turku, Finland
| | - O Solin
- Turku PET Centre, Radiopharmaceutical Chemistry Laboratory, University of Turku, Turku, Finland.,Department of Chemistry, University of Turku, Turku, Finland.,Accelerator Laboratory, Åbo Akademi University, Turku, Finland
| | - E Löyttyniemi
- Department of Biostatistics, University of Turku, Turku, Finland
| | - D C Anthony
- Department of Pharmacology, University of Oxford, Oxford, UK
| | - J O Rinne
- Turku PET Centre, Clinical Neurology, Turku University Hospital, Turku, Finland
| | - L Airas
- Turku PET Centre, Clinical Neurology, Turku University Hospital, Turku, Finland.,Division of Clinical Neurosciences, Turku University Hospital, Turku, Finland.,Department of Clinical Medicine, University of Turku, Turku, Finland
| | - M Haaparanta-Solin
- Turku PET Centre, Preclinical PET Imaging, University of Turku, Tykistökatu 6 A, 20520, Turku, Finland.,MediCity Research Laboratory, University of Turku, Turku, Finland
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19
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Magro-Checa C, Steup-Beekman GM, Huizinga TW, van Buchem MA, Ronen I. Laboratory and Neuroimaging Biomarkers in Neuropsychiatric Systemic Lupus Erythematosus: Where Do We Stand, Where To Go? Front Med (Lausanne) 2018; 5:340. [PMID: 30564579 PMCID: PMC6288259 DOI: 10.3389/fmed.2018.00340] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2018] [Accepted: 11/19/2018] [Indexed: 01/18/2023] Open
Abstract
Systemic lupus erythematosus (SLE) is a chronic autoimmune disease characterized by multi-systemic involvement. Nervous system involvement in SLE leads to a series of uncommon and heterogeneous neuropsychiatric (NP) manifestations. Current knowledge on the underlying pathogenic processes and their subsequent pathophysiological changes leading to NP-SLE manifestations is incomplete. Several putative laboratory biomarkers have been proposed as contributors to the genesis of SLE-related nervous system damage. Alongside the laboratory biomarkers, several neuroimaging tools have shown to reflect the nature of tissue microstructural damage associated with SLE, and thus were suggested to contribute to the understanding of the pathophysiological changes and subsequently help in clinical decision making. However, the number of useful biomarkers in NP-SLE in clinical practice is disconcertingly modest. In some cases it is not clear whether the biomarker is truly involved in pathogenesis, or the result of non-specific pathophysiological changes in the nervous system (e.g., neuroinflammation) or whether it is the consequence of a concomitant underlying abnormality related to SLE activity. In order to improve the diagnosis of NP-SLE and provide a better targeted care to these patients, there is still a need to develop and validate a range of biomarkers that reliably capture the different aspects of disease heterogeneity. This article critically reviews the current state of knowledge on laboratory and neuroimaging biomarkers in NP-SLE, discusses the factors that need to be addressed to make these biomarkers suitable for clinical application, and suggests potential future research paths to address important unmet needs in the NP-SLE field.
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Affiliation(s)
- César Magro-Checa
- Department of Rheumatology, Leiden University Medical Center, Leiden, Netherlands.,Department of Rheumatology, Zuyderland Medical Center, Heerlen, Netherlands
| | | | - Tom W Huizinga
- Department of Rheumatology, Leiden University Medical Center, Leiden, Netherlands
| | - Mark A van Buchem
- Department of Radiology, Leiden University Medical Center, Leiden, Netherlands.,Department of Radiology, C.J. Gorter Center for High Field MRI, Leiden University Medical Center, Leiden, Netherlands
| | - Itamar Ronen
- Department of Radiology, C.J. Gorter Center for High Field MRI, Leiden University Medical Center, Leiden, Netherlands
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20
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Chaney AM, Johnson EM, Cropper HC, James ML. PET Imaging of Neuroinflammation Using [11C]DPA-713 in a Mouse Model of Ischemic Stroke. J Vis Exp 2018. [PMID: 29985311 PMCID: PMC6101726 DOI: 10.3791/57243] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Neuroinflammation is central to the pathological cascade following ischemic stroke. Non-invasive molecular imaging methods have the potential to provide critical insights into the temporal dynamics and role of certain neuroimmune interactions in stroke. Specifically, Positron Emission Tomography (PET) imaging of translocator protein 18 kDa (TSPO), a marker of activated microglia and peripheral myeloid-lineage cells, provides a means to detect and track neuroinflammation in vivo. Here, we present a method to accurately quantify neuroinflammation using [11C]N,N-Diethyl-2-[2-(4-methoxyphenyl)-5,7-dimethylpyrazolo[1,5-a]pyrimidin-3-yl]acetamide ([11C]DPA-713), a promising second generation TSPO-PET radiotracer, in distal middle cerebral artery occlusion (dMCAO) compared to sham-operated mice. MRI was performed 2 days post-dMCAO surgery to confirm stroke and define the infarct location and volume. PET/Computed Tomography (CT) imaging was carried out 6 days post-dMCAO to capture the peak increase in TSPO levels following stroke. Quantitation of PET images was conducted to assess the uptake of [11C]DPA-713 in the brain and spleen of dMCAO and sham mice to assess central and peripheral levels of inflammation. In vivo [11C]DPA-713 brain uptake was confirmed using ex vivo autoradiography.
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Affiliation(s)
| | | | | | - Michelle L James
- Department of Radiology, Stanford University; Department of Neurology and Neurological Sciences, Stanford University;
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21
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Tang D, Fujinaga M, Hatori A, Zhang Y, Yamasaki T, Xie L, Mori W, Kumata K, Liu J, Manning HC, Huang G, Zhang MR. Evaluation of the novel TSPO radiotracer 2-(7-butyl-2-(4-(2-([ 18F]fluoroethoxy)phenyl)-5-methylpyrazolo[1,5-a]pyrimidin-3-yl)-N,N-diethylacetamide in a preclinical model of neuroinflammation. Eur J Med Chem 2018; 150:1-8. [PMID: 29505933 DOI: 10.1016/j.ejmech.2018.02.076] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2017] [Revised: 02/23/2018] [Accepted: 02/23/2018] [Indexed: 12/13/2022]
Abstract
Translocator Protein (18 kDa, TSPO) is regarded as a useful biomarker for neuroinflammation imaging. TSPO PET imaging could be used to understand the role of neuroinflammation in brain diseases and as a tool for evaluating novel therapeutic effects. As a promising TSPO probe, [18F]DPA-714 is highly specific and offers reliable quantification of TSPO in vivo. In this study, we further radiosynthesized and evaluated another novel TSPO probe, 2-(7-butyl-2-(4-(2-[18F]fluoroethoxy)phenyl)-5-methylpyrazolo[1,5-a]pyrimidin-3-yl)-N,N-diethylacetamide ([18F]VUIIS1018A), which features a 700-fold higher binding affinity for TSPO than that of [18F]DPA-714. We evaluated the performance of [18F]VUIIS1018A using dynamic in vivo PET imaging, radiometabolite analysis, in vitro autoradiography assays, biodistribution analysis, and blocking assays. In vivo study using this probe demonstrated high signal-to-noise ratio, binding potential (BPND), and binding specificity in preclinical neuroinflammation studies. Taken together, these findings indicate that [18F]VUIIS1018A may serve as a novel TSPO PET probe for neuroinflammation imaging.
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Affiliation(s)
- Dewei Tang
- Shanghai Key Laboratory for Molecular Imaging, Shanghai University of Medicine and Health Sciences, Shanghai 201318, China; Department of Nuclear Medicine, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, 160 Pu Jian Road, Shanghai 200127, China; Vanderbilt University Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, TN, United States
| | - Masayuki Fujinaga
- Department of Radiopharmaceuticals Development, National Institute of Radiological Science, National Institute for Quantum and Radiological Science and Technology, Chiba, Japan
| | - Akiko Hatori
- Department of Radiopharmaceuticals Development, National Institute of Radiological Science, National Institute for Quantum and Radiological Science and Technology, Chiba, Japan
| | - Yiding Zhang
- Department of Radiopharmaceuticals Development, National Institute of Radiological Science, National Institute for Quantum and Radiological Science and Technology, Chiba, Japan
| | - Tomoteru Yamasaki
- Department of Radiopharmaceuticals Development, National Institute of Radiological Science, National Institute for Quantum and Radiological Science and Technology, Chiba, Japan
| | - Lin Xie
- Department of Radiopharmaceuticals Development, National Institute of Radiological Science, National Institute for Quantum and Radiological Science and Technology, Chiba, Japan
| | - Wakana Mori
- Department of Radiopharmaceuticals Development, National Institute of Radiological Science, National Institute for Quantum and Radiological Science and Technology, Chiba, Japan
| | - Katsushi Kumata
- Department of Radiopharmaceuticals Development, National Institute of Radiological Science, National Institute for Quantum and Radiological Science and Technology, Chiba, Japan
| | - Jianjun Liu
- Shanghai Key Laboratory for Molecular Imaging, Shanghai University of Medicine and Health Sciences, Shanghai 201318, China; Department of Nuclear Medicine, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, 160 Pu Jian Road, Shanghai 200127, China; Institute of Clinical Nuclear Medicine, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200127, China
| | - H Charles Manning
- Vanderbilt University Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, TN, United States
| | - Gang Huang
- Shanghai Key Laboratory for Molecular Imaging, Shanghai University of Medicine and Health Sciences, Shanghai 201318, China; Institute of Clinical Nuclear Medicine, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200127, China; Institute of Health Sciences, Shanghai Jiao Tong University School of Medicine (SJTUSM) & Shanghai Institute for Biological Sciences (SIBS), Chinese Academy of Sciences (CAS), Shanghai 200025, China.
| | - Ming-Rong Zhang
- Department of Radiopharmaceuticals Development, National Institute of Radiological Science, National Institute for Quantum and Radiological Science and Technology, Chiba, Japan.
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22
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O'Loughlin E, Madore C, Lassmann H, Butovsky O. Microglial Phenotypes and Functions in Multiple Sclerosis. Cold Spring Harb Perspect Med 2018; 8:8/2/a028993. [PMID: 29419406 DOI: 10.1101/cshperspect.a028993] [Citation(s) in RCA: 61] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Microglia are the resident immune cells that constantly survey the central nervous system. They can adapt to their environment and respond to injury or insult by altering their morphology, phenotype, and functions. It has long been debated whether microglial activation is detrimental or beneficial in multiple sclerosis (MS). Recently, the two opposing yet connected roles of microglial activation have been described with the aid of novel microglial markers, RNA profiling, and in vivo models. In this review, microglial phenotypes and functions in the context of MS will be discussed with evidence from both human pathological studies, in vitro and in vivo models. Microglial functional diversity-phagocytosis, antigen presentation, immunomodulation, support, and repair-will also be examined in detail. In addition, this review discusses the emerging evidence for microglia-related targets as biomarkers and therapeutic targets for MS.
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Affiliation(s)
- Elaine O'Loughlin
- Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts 02115
| | - Charlotte Madore
- Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts 02115
| | - Hans Lassmann
- Center for Brain Research, Medical University of Vienna, A-1090 Vienna, Austria
| | - Oleg Butovsky
- Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts 02115.,Evergrande Center for Immunologic Diseases, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts 02115
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23
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Coupling between physiological TSPO expression in brain and myocardium allows stabilization of late-phase cerebral [18F]GE180 PET quantification. Neuroimage 2018; 165:83-91. [DOI: 10.1016/j.neuroimage.2017.10.006] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2017] [Revised: 09/29/2017] [Accepted: 10/03/2017] [Indexed: 01/31/2023] Open
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24
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Beaino W, Janssen B, Kooij G, van der Pol SMA, van Het Hof B, van Horssen J, Windhorst AD, de Vries HE. Purinergic receptors P2Y12R and P2X7R: potential targets for PET imaging of microglia phenotypes in multiple sclerosis. J Neuroinflammation 2017; 14:259. [PMID: 29273052 PMCID: PMC5741931 DOI: 10.1186/s12974-017-1034-z] [Citation(s) in RCA: 79] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2017] [Accepted: 12/11/2017] [Indexed: 12/12/2022] Open
Abstract
Background Microglia are major players in the pathogenesis of multiple sclerosis (MS) and may play a dual role in disease progression. The activation status of microglia in vivo is highly dynamic and occurs as a continuum, with the pro-inflammatory and anti-inflammatory phenotypes on either end of this spectrum. Little is known about in vivo dynamics of microglia phenotypes in MS due to the lack of diagnostic tools. Positron emission tomography (PET) imaging is a powerful non-invasive technique that allows real-time imaging of microglia activation phenotypes in the central nervous system, depending on the availability of selective PET tracers. Our objective is to investigate and characterize the expression of the purinergic receptors P2Y12R and P2X7R as potential targets for PET tracer development and subsequent PET imaging in order to evaluate the dynamics of microglia status in vivo. Methods We used immunohistochemical analysis to explore the expression of P2Y12R and P2X7R in experimental autoimmune encephalomyelitis (EAE) post-mortem tissues and different stages of well-characterized MS lesions. We evaluated by quantitative real-time polymerase chain reaction the expression of P2Y12R and P2X7R in human polarized microglia, and we performed autoradiography binding assay with radiolabeled P2Y12R and P2X7R antagonists using MS and rat EAE tissues. Results Here, we demonstrate that P2X7R is associated with a pro-inflammatory phenotype of human microglia in vitro, and is highly expressed in microglia in MS lesions as well as during the peak of EAE. In contrast, P2Y12R was associated with an anti-inflammatory phenotype in human microglia in vitro and was expressed at lower levels in active inflammatory MS lesions compared to normal-appearing white matter (NAWM) and similarly in EAE, while its expression increased in the remission phase of EAE. Binding of radiolabeled tracers specific for P2Y12R and P2X7R on ex vivo tissues validated the value of these receptors as PET imaging targets for microglia phenotypes in vivo. Conclusion Our results suggest that P2Y12R and P2X7R are excellent targets for PET imaging to discriminate distinct microglia phenotypes in MS. Ultimately, this may provide insight into the role of microglia in disease progression and monitor novel treatment strategies to alter microglia phenotype. Electronic supplementary material The online version of this article (10.1186/s12974-017-1034-z) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Wissam Beaino
- Department of Radiology and Nuclear Medicine, VU University Medical Center, Amsterdam, The Netherlands.
| | - Bieneke Janssen
- Department of Radiology and Nuclear Medicine, VU University Medical Center, Amsterdam, The Netherlands
| | - Gijs Kooij
- Department of Molecular Cell Biology and Immunology, VUmc MS Center Amsterdam, Amsterdam Neuroscience, VU University Medical Center, Amsterdam, The Netherlands
| | - Susanne M A van der Pol
- Department of Molecular Cell Biology and Immunology, VUmc MS Center Amsterdam, Amsterdam Neuroscience, VU University Medical Center, Amsterdam, The Netherlands
| | - B van Het Hof
- Department of Molecular Cell Biology and Immunology, VUmc MS Center Amsterdam, Amsterdam Neuroscience, VU University Medical Center, Amsterdam, The Netherlands
| | - Jack van Horssen
- Department of Molecular Cell Biology and Immunology, VUmc MS Center Amsterdam, Amsterdam Neuroscience, VU University Medical Center, Amsterdam, The Netherlands
| | - Albert D Windhorst
- Department of Radiology and Nuclear Medicine, VU University Medical Center, Amsterdam, The Netherlands
| | - Helga E de Vries
- Department of Molecular Cell Biology and Immunology, VUmc MS Center Amsterdam, Amsterdam Neuroscience, VU University Medical Center, Amsterdam, The Netherlands
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25
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Bunai T, Terada T, Kono S, Yokokura M, Yoshikawa E, Futatsubashi M, Miyajima H, Ouchi Y. Neuroinflammation following disease modifying therapy in multiple sclerosis: A pilot positron emission tomography study. J Neurol Sci 2017; 385:30-33. [PMID: 29406909 DOI: 10.1016/j.jns.2017.12.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2017] [Revised: 12/04/2017] [Accepted: 12/05/2017] [Indexed: 11/20/2022]
Abstract
INTRODUCTION Chronic activation of microglia accelerates the neurodegenerative process in multiple sclerosis (MS). Although disease modifying therapy (DMT) is reportedly effective for neuroinflammatory responses in MS, the progression of neuroinflammation after DMT remains unclear. METHODS We evaluated microglial activation in six clinically stable relapsing-remitting MS patients after DMT by quantifying changes in translocator protein (TSPO) density using PET with [11C]DPA713, a selective TSPO tracer for microglial activation. All patients underwent [11C]DPA713 PET scans twice, and the scans were conducted one year apart. The binding potential (BPND) of the tracer was estimated using a simplified reference tissue model. RESULTS [11C]DPA713 BPND measured at 6months after DMT was significantly higher in the MS group than that in the control group. Compared with the first PET measurement, the one-year PET measurement revealed significantly elevated [11C]DPA713 BPND in broader brain regions covering the temporal and parietal cortices after one year of DMT. CONCLUSIONS The current results indicate that microglial activation may proceed in the entire brain of clinically stable MS patients even after receiving DMT.
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Affiliation(s)
- Tomoyasu Bunai
- Department of Biofunctional Imaging, Preeminent Medical Photonics Education & Research Center, Hamamatsu University School of Medicine, Hamamatsu, Japan
| | - Tatsuhiro Terada
- Department of Biofunctional Imaging, Preeminent Medical Photonics Education & Research Center, Hamamatsu University School of Medicine, Hamamatsu, Japan
| | - Satoshi Kono
- First Department of Medicine, Hamamatsu University School of Medicine, Hamamatsu, Japan
| | - Masamichi Yokokura
- Department of Psychiatry, Hamamatsu University School of Medicine, Hamamatsu, Japan
| | - Etsuji Yoshikawa
- Central Research Laboratory, Hamamatsu Photonics K.K., Hamamatsu, Japan
| | | | - Hiroaki Miyajima
- First Department of Medicine, Hamamatsu University School of Medicine, Hamamatsu, Japan
| | - Yasuomi Ouchi
- Department of Biofunctional Imaging, Preeminent Medical Photonics Education & Research Center, Hamamatsu University School of Medicine, Hamamatsu, Japan.
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26
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In Vivo PET Imaging of Adenosine 2A Receptors in Neuroinflammatory and Neurodegenerative Disease. CONTRAST MEDIA & MOLECULAR IMAGING 2017; 2017:6975841. [PMID: 29348737 PMCID: PMC5733838 DOI: 10.1155/2017/6975841] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/10/2017] [Accepted: 10/18/2017] [Indexed: 01/01/2023]
Abstract
Adenosine receptors are G-protein coupled P1 purinergic receptors that are broadly expressed in the peripheral immune system, vasculature, and the central nervous system (CNS). Within the immune system, adenosine 2A (A2A) receptor-mediated signaling exerts a suppressive effect on ongoing inflammation. In healthy CNS, A2A receptors are expressed mainly within the neurons of the basal ganglia. Alterations in A2A receptor function and expression have been noted in movement disorders, and in Parkinson's disease pharmacological A2A receptor antagonism leads to diminished motor symptoms. Although A2A receptors are expressed only at a low level in the healthy CNS outside striatum, pathological challenge or inflammation has been shown to lead to upregulation of A2A receptors in extrastriatal CNS tissue, and this has been successfully quantitated using in vivo positron emission tomography (PET) imaging and A2A receptor-binding radioligands. Several radioligands for PET imaging of A2A receptors have been developed in recent years, and A2A receptor-targeting PET imaging may thus provide a potential additional tool to evaluate various aspects of neuroinflammation in vivo. This review article provides a brief overview of A2A receptors in healthy brain and in a selection of most important neurological diseases and describes the recent advances in A2A receptor-targeting PET imaging studies.
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27
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Owen DR, Narayan N, Wells L, Healy L, Smyth E, Rabiner EA, Galloway D, Williams JB, Lehr J, Mandhair H, Peferoen LA, Taylor PC, Amor S, Antel JP, Matthews PM, Moore CS. Pro-inflammatory activation of primary microglia and macrophages increases 18 kDa translocator protein expression in rodents but not humans. J Cereb Blood Flow Metab 2017; 37:2679-2690. [PMID: 28530125 PMCID: PMC5536262 DOI: 10.1177/0271678x17710182] [Citation(s) in RCA: 131] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The 18kDa Translocator Protein (TSPO) is the most commonly used tissue-specific marker of inflammation in positron emission tomography (PET) studies. It is expressed in myeloid cells such as microglia and macrophages, and in rodent myeloid cells expression increases with cellular activation. We assessed the effect of myeloid cell activation on TSPO gene expression in both primary human and rodent microglia and macrophages in vitro, and also measured TSPO radioligand binding with 3H-PBR28 in primary human macrophages. As observed previously, we found that TSPO expression increases (∼9-fold) in rodent-derived macrophages and microglia upon pro-inflammatory stimulation. However, TSPO expression does not increase with classical pro-inflammatory activation in primary human microglia (fold change 0.85 [95% CI 0.58-1.12], p = 0.47). In contrast, pro-inflammatory activation of human monocyte-derived macrophages is associated with a reduction of both TSPO gene expression (fold change 0.60 [95% CI 0.45-0.74], p = 0.02) and TSPO binding site abundance (fold change 0.61 [95% CI 0.49-0.73], p < 0.0001). These findings have important implications for understanding the biology of TSPO in activated macrophages and microglia in humans. They are also clinically relevant for the interpretation of PET studies using TSPO targeting radioligands, as they suggest changes in TSPO expression may reflect microglial and macrophage density rather than activation phenotype.
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Affiliation(s)
- David R Owen
- 1 Division of Brain Sciences, Department of Medicine Hammersmith Hospital, Imperial College London, London, UK
| | - Nehal Narayan
- 2 Nuffield Department of Orthopaedics, Rheumatology & Musculoskeletal Sciences, Botnar Research Centre, University of Oxford, Oxford, UK
| | - Lisa Wells
- 3 Imanova Centre for Imaging Science, Hammersmith Hospital, London, UK
| | - Luke Healy
- 4 Neuroimmunology Unit, Montreal Neurological Institute, McGill University, Montreal, Quebec, Canada
| | - Erica Smyth
- 3 Imanova Centre for Imaging Science, Hammersmith Hospital, London, UK
| | - Eugenii A Rabiner
- 3 Imanova Centre for Imaging Science, Hammersmith Hospital, London, UK.,5 Centre for Neuroimaging Sciences, King's College, London, UK
| | - Dylan Galloway
- 6 Division of Biomedical Sciences, Faculty of Medicine, Memorial University of Newfoundland, St. John's, Newfoundland
| | - John B Williams
- 6 Division of Biomedical Sciences, Faculty of Medicine, Memorial University of Newfoundland, St. John's, Newfoundland
| | - Joshua Lehr
- 6 Division of Biomedical Sciences, Faculty of Medicine, Memorial University of Newfoundland, St. John's, Newfoundland
| | - Harpreet Mandhair
- 2 Nuffield Department of Orthopaedics, Rheumatology & Musculoskeletal Sciences, Botnar Research Centre, University of Oxford, Oxford, UK
| | - Laura An Peferoen
- 7 Pathology Department, VU Medical Centre, VU University of Amsterdam, The Netherlands
| | - Peter C Taylor
- 2 Nuffield Department of Orthopaedics, Rheumatology & Musculoskeletal Sciences, Botnar Research Centre, University of Oxford, Oxford, UK
| | - Sandra Amor
- 7 Pathology Department, VU Medical Centre, VU University of Amsterdam, The Netherlands.,8 Neuroimmunology Unit, Blizard Institute, Barts and the London School of medicine & Dentistry Queen Mary University of London, UK
| | - Jack P Antel
- 4 Neuroimmunology Unit, Montreal Neurological Institute, McGill University, Montreal, Quebec, Canada
| | - Paul M Matthews
- 1 Division of Brain Sciences, Department of Medicine Hammersmith Hospital, Imperial College London, London, UK.,9 UK Dementia Research Institute, Imperial College London, London, UK
| | - Craig S Moore
- 6 Division of Biomedical Sciences, Faculty of Medicine, Memorial University of Newfoundland, St. John's, Newfoundland
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28
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Vāvere AL, Scott PJH. Clinical Applications of Small-molecule PET Radiotracers: Current Progress and Future Outlook. Semin Nucl Med 2017; 47:429-453. [PMID: 28826519 DOI: 10.1053/j.semnuclmed.2017.05.001] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Radiotracers, or radiopharmaceuticals, are bioactive molecules tagged with a radionuclide used for diagnostic imaging or radiotherapy and, when a positron-emitting radionuclide is chosen, the radiotracers are used for PET imaging. The development of novel PET radiotracers in many ways parallels the development of new pharmaceuticals, and small molecules dominate research and development pipelines in both disciplines. The 4 decades since the introduction of [18F]FDG have seen the development of many small molecule PET radiotracers. Ten have been approved by the US Food and Drug Administration as of 2016, whereas hundreds more are being evaluated clinically. These radiotracers are being used in personalized medicine and to support drug discovery programs where they are greatly improving our understanding of and ability to treat diseases across many areas of medicine including neuroscience, cardiovascular medicine, and oncology.
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Affiliation(s)
- Amy L Vāvere
- Department of Diagnostic Imaging, St. Jude Children's Research Hospital, Memphis, TN
| | - Peter J H Scott
- Department of Radiology, University of Michigan, Ann Arbor, MI.
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29
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Sucksdorff M, Rissanen E, Tuisku J, Nuutinen S, Paavilainen T, Rokka J, Rinne J, Airas L. Evaluation of the Effect of Fingolimod Treatment on Microglial Activation Using Serial PET Imaging in Multiple Sclerosis. J Nucl Med 2017; 58:1646-1651. [PMID: 28336784 DOI: 10.2967/jnumed.116.183020] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2016] [Accepted: 03/13/2017] [Indexed: 01/07/2023] Open
Abstract
Traditionally, multiple sclerosis (MS) has been considered a white matter disease with focal inflammatory lesions. It is, however, becoming clear that significant pathology, such as microglial activation, also takes place outside the plaque areas, that is, in areas of normal-appearing white matter (NAWM) and gray matter (GM). Microglial activation can be detected in vivo using 18-kDa translocator protein (TSPO)-binding radioligands and PET. It is unknown whether fingolimod affects microglial activation in MS. The aim of this study was to investigate whether serial PET can be used to evaluate the effect of fingolimod treatment on microglial activation. Methods: Ten relapsing-remitting MS patients were studied using the TSPO radioligand 11C-(R)-PK11195. Imaging was performed at baseline and after 8 and 24 wk of fingolimod treatment. Eight healthy individuals were imaged for comparison. Microglial activation was evaluated as distribution volume ratio of 11C-(R)-PK11195. Results: The patients had MS for an average of 7.9 ± 4.3 y (mean ± SD), their total relapses averaged 4 ± 2.4, and their Expanded Disability Status Scale was 2.7 ± 0.5. The patients were switched to fingolimod because of safety reasons or therapy escalation. The mean washout period before the initiation of fingolimod was 2.3 ± 1.1 mo. The patients were clinically stable on fingolimod. At baseline, microglial activation was significantly higher in the combined NAWM and GM areas of MS patients than in healthy controls (P = 0.021). 11C-(R)-PK11195 binding was reduced (-12.31%) within the combined T2 lesion area after 6 mo of fingolimod treatment (P = 0.040) but not in the areas of NAWM or GM. Conclusion: Fingolimod treatment reduced microglial/macrophage activation at the site of focal inflammatory lesions, presumably by preventing leukocyte trafficking from the periphery. It did not affect the widespread, diffuse microglial activation in the NAWM and GM. The study opens new vistas for designing future therapeutic studies in MS that use the evaluation of microglial activation as an imaging outcome measure.
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Affiliation(s)
- Marcus Sucksdorff
- Division of Clinical Neurosciences, Turku University Hospital, Kiinamyllynkatu 4-8, Turku, Finland; and .,Turku PET Centre, Clinical Neurology, University of Turku, Kiinamyllynkatu 4-8, Turku, Finland
| | - Eero Rissanen
- Division of Clinical Neurosciences, Turku University Hospital, Kiinamyllynkatu 4-8, Turku, Finland; and.,Turku PET Centre, Clinical Neurology, University of Turku, Kiinamyllynkatu 4-8, Turku, Finland
| | - Jouni Tuisku
- Turku PET Centre, Clinical Neurology, University of Turku, Kiinamyllynkatu 4-8, Turku, Finland
| | - Salla Nuutinen
- Division of Clinical Neurosciences, Turku University Hospital, Kiinamyllynkatu 4-8, Turku, Finland; and
| | - Teemu Paavilainen
- Turku PET Centre, Clinical Neurology, University of Turku, Kiinamyllynkatu 4-8, Turku, Finland
| | - Johanna Rokka
- Turku PET Centre, Clinical Neurology, University of Turku, Kiinamyllynkatu 4-8, Turku, Finland
| | - Juha Rinne
- Division of Clinical Neurosciences, Turku University Hospital, Kiinamyllynkatu 4-8, Turku, Finland; and.,Turku PET Centre, Clinical Neurology, University of Turku, Kiinamyllynkatu 4-8, Turku, Finland
| | - Laura Airas
- Division of Clinical Neurosciences, Turku University Hospital, Kiinamyllynkatu 4-8, Turku, Finland; and.,Turku PET Centre, Clinical Neurology, University of Turku, Kiinamyllynkatu 4-8, Turku, Finland
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30
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Abstract
The discovery and development of central nervous system (CNS) drugs is an extremely challenging process requiring large resources, timelines, and associated costs. The high risk of failure leads to high levels of risk. Over the past couple of decades PET imaging has become a central component of the CNS drug-development process, enabling decision-making in phase I studies, where early discharge of risk provides increased confidence to progress a candidate to more costly later phase testing at the right dose level or alternatively to kill a compound through failure to meet key criteria. The so called "3 pillars" of drug survival, namely; tissue exposure, target engagement, and pharmacologic activity, are particularly well suited for evaluation by PET imaging. This review introduces the process of CNS drug development before considering how PET imaging of the "3 pillars" has advanced to provide valuable tools for decision-making on the critical path of CNS drug development. Finally, we review the advances in PET science of biomarker development and analysis that enable sophisticated drug-development studies in man.
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Affiliation(s)
- Roger N Gunn
- Imanova Ltd, London, United Kingdom; Division of Brain Sciences, Imperial College London, London, United Kingdom; Department of Engineering Science, Institute of Biomedical Engineering, University of Oxford, Oxford, United Kingdom.
| | - Eugenii A Rabiner
- Imanova Ltd, London, United Kingdom; Department of Neuroimaging, Institute of Psychiatry, Psychology and Neuroscience (IoPPN), King's College London, London, United Kingdom
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31
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Airas L, Rissanen E, Rinne J. Imaging of microglial activation in MS using PET: Research use and potential future clinical application. Mult Scler 2016; 23:496-504. [PMID: 27760860 DOI: 10.1177/1352458516674568] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Multiple sclerosis (MS) is a complex disease, where several processes can be selected as a target for positron emission topography (PET) imaging. Unlike magnetic resonance imaging (MRI), PET provides specific and quantitative information, and unlike neuropathology, it can be non-invasively applied to living patients, which enables longitudinal follow-up of the MS pathology. In the study of MS, PET can be useful for in vivo evaluation of specific pathological characteristics at various stages of the disease. Increased understanding of the progressive MS pathology will enhance the treatment options of this undertreated condition. The ultimate goal of developing and expanding PET in the study of MS is to have clinical non-invasive in vivo imaging biomarkers of neuroinflammation that will help to establish prognosis and accurately measure response to therapeutics. This topical review provides an overview of the promises and challenges of the use of PET in MS.
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Affiliation(s)
- Laura Airas
- Division of Clinical Neurosciences, Turku University Hospital and University of Turku, Turku, Finland; Turku PET Centre, Turku University Hospital and University of Turku, Turku, Finland
| | - Eero Rissanen
- Division of Clinical Neurosciences, Turku University Hospital and University of Turku, Turku, Finland; Turku PET Centre, Turku University Hospital and University of Turku, Turku, Finland
| | - Juha Rinne
- Division of Clinical Neurosciences, Turku University Hospital and University of Turku, Turku, Finland; Turku PET Centre, Turku University Hospital and University of Turku, Turku, Finland
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32
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Albrecht DS, Granziera C, Hooker JM, Loggia ML. In Vivo Imaging of Human Neuroinflammation. ACS Chem Neurosci 2016; 7:470-83. [PMID: 26985861 DOI: 10.1021/acschemneuro.6b00056] [Citation(s) in RCA: 133] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Neuroinflammation is implicated in the pathophysiology of a growing number of human disorders, including multiple sclerosis, chronic pain, traumatic brain injury, and amyotrophic lateral sclerosis. As a result, interest in the development of novel methods to investigate neuroinflammatory processes, for the purpose of diagnosis, development of new therapies, and treatment monitoring, has surged over the past 15 years. Neuroimaging offers a wide array of non- or minimally invasive techniques to characterize neuroinflammatory processes. The intent of this Review is to provide brief descriptions of currently available neuroimaging methods to image neuroinflammation in the human central nervous system (CNS) in vivo. Specifically, because of the relatively widespread accessibility of equipment for nuclear imaging (positron emission tomography [PET]; single photon emission computed tomography [SPECT]) and magnetic resonance imaging (MRI), we will focus on strategies utilizing these technologies. We first provide a working definition of "neuroinflammation" and then discuss available neuroimaging methods to study human neuroinflammatory processes. Specifically, we will focus on neuroimaging methods that target (1) the activation of CNS immunocompetent cells (e.g. imaging of glial activation with TSPO tracer [(11)C]PBR28), (2) compromised BBB (e.g. identification of MS lesions with gadolinium-enhanced MRI), (3) CNS-infiltration of circulating immune cells (e.g. tracking monocyte infiltration into brain parenchyma with iron oxide nanoparticles and MRI), and (4) pathological consequences of neuroinflammation (e.g. imaging apoptosis with [(99m)Tc]Annexin V or iron accumulation with T2* relaxometry). This Review provides an overview of state-of-the-art techniques for imaging human neuroinflammation which have potential to impact patient care in the foreseeable future.
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Affiliation(s)
| | - Cristina Granziera
- Neuro-Immunology,
Neurology Division, Department of Clinical Neurosciences, Centre Hospitalier
Universitaire Vaudois and University of Lausanne, CH-1011 Lausanne, Switzerland
- LTS5, Ecole
Polytechnique
Fédérale de Lausanne, CH-1015 Lausanne, Switzerland
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