1
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Wong NR, Rubin LH, Harrington CK, Jenkins KR, Shinehouse LK, Yoon M, Kilgore JJ, Soule AR, Lesniak WG, Rowe SP, Horti AG, Kamath V, Dannals RF, Du Y, Pomper MG, Coughlin JM. Hippocampal Availability of the α7 Nicotinic Acetylcholine Receptor in Recent-Onset Psychosis. JAMA Netw Open 2024; 7:e2427163. [PMID: 39133487 PMCID: PMC11320165 DOI: 10.1001/jamanetworkopen.2024.27163] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/20/2024] [Accepted: 06/13/2024] [Indexed: 08/13/2024] Open
Abstract
Importance Studies using human postmortem tissue and imaging with positron emission tomography (PET) support a low hippocampal availability of the α7 nicotinic acetylcholine receptor (α7-nAChR) in psychotic conditions, particularly in schizophrenia or schizoaffective disorder (nonaffective psychosis). If validated further, the finding may have implications for clinical diagnosis and treatment. Objective To test for lower availability of the α7-nAChR in the hippocampus of individuals with recent-onset psychosis compared with healthy control individuals and its association with lower cognitive performance or higher psychotic symptom burden within recent-onset psychosis. Design, Setting, and Participants In this cross-sectional study, healthy individuals without history of psychosis and patients within 10 years of a first onset of psychotic disorder were recruited from the greater Baltimore, Maryland, and Washington, DC, area. Fluorine 18-labeled ASEM ([18F] ASEM) PET data were acquired from participants enrolled between March 1, 2014, and July 31, 2023, from an academic research institution. Data acquired between March 1, 2014, and January 31, 2018 (n = 26), were published as a pilot study and were combined with new data acquired between January 1, 2019, and July 31, 2023 (n = 33). Main Outcome and Measures Regional [18F]ASEM total distribution volume (VT) that measures α7-nAChR availability, global cognition composite score, and total scores on the Scale for the Assessment of Positive Symptoms and the Scale for the Assessment of Negative Symptoms. Results A total of 59 participants (30 women [51%]; mean [SD] age, 25.5 [5.2] years), including 35 with recent-onset psychosis and 24 healthy controls, completed the study. In age-adjusted analyses, lower hippocampal [18F]ASEM VT was found in individuals with recent-onset psychosis (mean [SE], 17.87 [0.60]) compared with healthy controls (mean [SE], 19.82 [0.73]) (P = .04). In addition, [18F]ASEM VT was lower in individuals with nonaffective psychosis (mean [SE], 16.30 [0.83]) compared with healthy controls (P = .006) or those with affective psychosis (mean [SE], 19.34 [0.80]) (P = .03). Across recent-onset psychosis and after controlling for age, lower hippocampal [18F]ASEM VT was associated with more positive (r = -0.44; P = .009) but not negative symptoms, and higher hippocampal VT was associated with better global cognition composite score (r = 0.38; P = .03). Conclusions and Relevance In this cross-sectional study of individuals with recent-onset psychosis compared with healthy controls, a lower hippocampal α7-nAChR availability was found in recent-onset psychosis, and its availability was lower in those with nonaffective vs affective psychosis. Further study of the association between low availability of the α7-nAChR and recent-onset psychosis is warranted toward informing diagnostic or therapeutic strategies related to these findings.
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Affiliation(s)
- Nicole R. Wong
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Leah H. Rubin
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, Maryland
- Department of Epidemiology, Johns Hopkins University School of Medicine, Baltimore, Maryland
- Department of Molecular and Comparative Pathobiology, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Courtney K. Harrington
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Katelyn R. Jenkins
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Laura K. Shinehouse
- The Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Mark Yoon
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Jessica J. Kilgore
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Ana R. Soule
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Wojciech G. Lesniak
- The Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Steven P. Rowe
- Department of Radiology, University of North Carolina, Chapel Hill
| | - Andrew G. Horti
- The Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Vidyulata Kamath
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Robert F. Dannals
- The Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Yong Du
- The Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Martin G. Pomper
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland
- The Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Jennifer M. Coughlin
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, Maryland
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2
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Du Y, Coughlin JM, Amindarolzarbi A, Sweeney SE, Harrington CK, Brosnan MK, Zandi A, Shinehouse LK, Sanchez ANR, Abdallah R, Holt DP, Fan H, Lesniak WG, Nandi A, Rowe SP, Solnes LB, Dannals RF, Horti AG, Lodge MA, Pomper MG. [ 18F]FNDP PET neuroimaging test-retest repeatability and whole-body dosimetry in humans. Eur J Nucl Med Mol Imaging 2023; 50:3659-3665. [PMID: 37458759 DOI: 10.1007/s00259-023-06331-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2023] [Accepted: 07/04/2023] [Indexed: 10/04/2023]
Abstract
PURPOSE Soluble epoxide hydrolase (sEH) is an enzyme that shapes immune signaling through its role in maintaining the homeostasis of polyunsaturated fatty acids and their related byproducts. [18F]FNDP is a radiotracer developed for use with positron emission tomography (PET) to image sEH, which has been applied to imaging sEH in the brains of healthy individuals. Here, we report the test-retest repeatability of [18F]FNDP brain PET binding and [18F]FNDP whole-body dosimetry in healthy individuals. METHODS Seven healthy adults (4 men, 3 women, ages 40.1 ± 4.6 years) completed [18F]FNDP brain PET on two occasions within a period of 14 days in a test-retest study design. [18F]FNDP regional total distribution volume (VT) values were derived from modeling time-activity data with a metabolite-corrected arterial input function. Test-retest variability, mean absolute deviation, and intraclass correlation coefficient (ICC) were investigated. Six other healthy adults (3 men, 3 women, ages 46.0 ± 7.0 years) underwent [18F]FNDP PET/CT for whole-body dosimetry, which was acquired over 4.5 h, starting immediately after radiotracer administration. Organ-absorbed doses and the effective dose were then estimated. RESULTS The mean test-retest difference in regional VT (ΔVT) was 0.82 ± 5.17%. The mean absolute difference in regional VT was 4.01 ± 3.33%. The ICC across different brain regions ranged from 0.92 to 0.99. The organs with the greatest radiation-absorbed doses included the gallbladder (0.081 ± 0.024 mSv/MBq), followed by liver (0.077 ± 0.018 mSv/MBq) and kidneys (0.063 ± 0.006 mSv/MBq). The effective dose was 0.020 ± 0.003 mSv/MBq. CONCLUSION These data support a favorable test-retest repeatability of [18F]FNDP brain PET regional VT. The radiation dose to humans from each [18F]FNDP PET scan is similar to that of other 18F-based PET radiotracers.
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Affiliation(s)
- Yong Du
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, MD, USA
| | - Jennifer M Coughlin
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins Medical Institutions, Baltimore, MD, USA
| | - Alireza Amindarolzarbi
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, MD, USA
| | - Shannon Eileen Sweeney
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins Medical Institutions, Baltimore, MD, USA
| | - Courtney K Harrington
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins Medical Institutions, Baltimore, MD, USA
| | - Mary Katherine Brosnan
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, MD, USA
| | - Adeline Zandi
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, MD, USA
| | - Laura K Shinehouse
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, MD, USA
| | - Alejandra N Reyes Sanchez
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins Medical Institutions, Baltimore, MD, USA
| | - Rehab Abdallah
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, MD, USA
| | - Daniel P Holt
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, MD, USA
| | - Hong Fan
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, MD, USA
| | - Wojciech G Lesniak
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, MD, USA
| | - Ayon Nandi
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, MD, USA
| | - Steven P Rowe
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, MD, USA
| | - Lilja B Solnes
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, MD, USA
| | - Robert F Dannals
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, MD, USA
| | - Andrew G Horti
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, MD, USA
| | - Martin A Lodge
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, MD, USA
| | - Martin G Pomper
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, MD, USA.
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins Medical Institutions, Baltimore, MD, USA.
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3
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Zhang JJ, Fu H, Lin R, Zhou J, Haider A, Fang W, Elghazawy NH, Rong J, Chen J, Li Y, Ran C, Collier TL, Chen Z, Liang SH. Imaging Cholinergic Receptors in the Brain by Positron Emission Tomography. J Med Chem 2023; 66:10889-10916. [PMID: 37583063 PMCID: PMC10461233 DOI: 10.1021/acs.jmedchem.3c00573] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Indexed: 08/17/2023]
Abstract
Cholinergic receptors represent a promising class of diagnostic and therapeutic targets due to their significant involvement in cognitive decline associated with neurological disorders and neurodegenerative diseases as well as cardiovascular impairment. Positron emission tomography (PET) is a noninvasive molecular imaging tool that has helped to shed light on the roles these receptors play in disease development and their diverse functions throughout the central nervous system (CNS). In recent years, there has been a notable advancement in the development of PET probes targeting cholinergic receptors. The purpose of this review is to provide a comprehensive overview of the recent progress in the development of these PET probes for cholinergic receptors with a specific focus on ligand structure, radiochemistry, and pharmacology as well as in vivo performance and applications in neuroimaging. The review covers the structural design, pharmacological properties, radiosynthesis approaches, and preclinical and clinical evaluations of current state-of-the-art PET probes for cholinergic receptors.
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Affiliation(s)
- Jing-Jing Zhang
- Jiangsu
Co-Innovation Center of Efficient Processing and Utilization of Forest
Resources, Jiangsu Provincial Key Lab for the Chemistry and Utilization
of Agro-Forest Biomass, Jiangsu Key Lab of Biomass-Based Green Fuels
and Chemicals, International Innovation Center for Forest Chemicals
and Materials, College of Chemical Engineering, Nanjing Forestry University, Nanjing, Jiangsu 210037, China
| | - Hualong Fu
- Division
of Nuclear Medicine and Molecular Imaging, Massachusetts General Hospital
& Department of Radiology, Harvard Medical
School, Boston, Massachusetts 02114, United States
- Key
Laboratory of Radiopharmaceuticals, Ministry of Education, College
of Chemistry, Beijing Normal University, Beijing 100875, China
| | - Ruofan Lin
- Jiangsu
Co-Innovation Center of Efficient Processing and Utilization of Forest
Resources, Jiangsu Provincial Key Lab for the Chemistry and Utilization
of Agro-Forest Biomass, Jiangsu Key Lab of Biomass-Based Green Fuels
and Chemicals, International Innovation Center for Forest Chemicals
and Materials, College of Chemical Engineering, Nanjing Forestry University, Nanjing, Jiangsu 210037, China
| | - Jingyin Zhou
- Key
Laboratory of Radiopharmaceuticals, Ministry of Education, College
of Chemistry, Beijing Normal University, Beijing 100875, China
| | - Ahmed Haider
- Division
of Nuclear Medicine and Molecular Imaging, Massachusetts General Hospital
& Department of Radiology, Harvard Medical
School, Boston, Massachusetts 02114, United States
- Department
of Radiology and Imaging Sciences, Emory
University, 1364 Clifton Road, Atlanta, Georgia 30322, United States
| | - Weiwei Fang
- Jiangsu
Co-Innovation Center of Efficient Processing and Utilization of Forest
Resources, Jiangsu Provincial Key Lab for the Chemistry and Utilization
of Agro-Forest Biomass, Jiangsu Key Lab of Biomass-Based Green Fuels
and Chemicals, International Innovation Center for Forest Chemicals
and Materials, College of Chemical Engineering, Nanjing Forestry University, Nanjing, Jiangsu 210037, China
| | - Nehal H. Elghazawy
- Department
of Pharmaceutical, Chemistry, Faculty of Pharmacy & Biotechnology, German University in Cairo, 11835 Cairo, Egypt
| | - Jian Rong
- Division
of Nuclear Medicine and Molecular Imaging, Massachusetts General Hospital
& Department of Radiology, Harvard Medical
School, Boston, Massachusetts 02114, United States
- Department
of Radiology and Imaging Sciences, Emory
University, 1364 Clifton Road, Atlanta, Georgia 30322, United States
| | - Jiahui Chen
- Division
of Nuclear Medicine and Molecular Imaging, Massachusetts General Hospital
& Department of Radiology, Harvard Medical
School, Boston, Massachusetts 02114, United States
- Department
of Radiology and Imaging Sciences, Emory
University, 1364 Clifton Road, Atlanta, Georgia 30322, United States
| | - Yinlong Li
- Division
of Nuclear Medicine and Molecular Imaging, Massachusetts General Hospital
& Department of Radiology, Harvard Medical
School, Boston, Massachusetts 02114, United States
- Department
of Radiology and Imaging Sciences, Emory
University, 1364 Clifton Road, Atlanta, Georgia 30322, United States
| | - Chongzhao Ran
- Athinoula
A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts 02114, United States
| | - Thomas L. Collier
- Division
of Nuclear Medicine and Molecular Imaging, Massachusetts General Hospital
& Department of Radiology, Harvard Medical
School, Boston, Massachusetts 02114, United States
- Department
of Radiology and Imaging Sciences, Emory
University, 1364 Clifton Road, Atlanta, Georgia 30322, United States
| | - Zhen Chen
- Jiangsu
Co-Innovation Center of Efficient Processing and Utilization of Forest
Resources, Jiangsu Provincial Key Lab for the Chemistry and Utilization
of Agro-Forest Biomass, Jiangsu Key Lab of Biomass-Based Green Fuels
and Chemicals, International Innovation Center for Forest Chemicals
and Materials, College of Chemical Engineering, Nanjing Forestry University, Nanjing, Jiangsu 210037, China
- Division
of Nuclear Medicine and Molecular Imaging, Massachusetts General Hospital
& Department of Radiology, Harvard Medical
School, Boston, Massachusetts 02114, United States
| | - Steven H. Liang
- Division
of Nuclear Medicine and Molecular Imaging, Massachusetts General Hospital
& Department of Radiology, Harvard Medical
School, Boston, Massachusetts 02114, United States
- Department
of Radiology and Imaging Sciences, Emory
University, 1364 Clifton Road, Atlanta, Georgia 30322, United States
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4
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Du Y, Coughlin JM, Brosnan MK, Chen A, Shinehouse LK, Abdallah R, Lodge MA, Mathews WB, Liu C, Wu Y, Minn I, Finley P, Hall AW, Lesniak WG, Dannals RF, Horti AG, Pomper MG. First-in-human imaging using [ 11C]MDTC: a radiotracer targeting the cannabinoid receptor type 2. Eur J Nucl Med Mol Imaging 2023; 50:2386-2393. [PMID: 36877235 DOI: 10.1007/s00259-023-06170-y] [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: 01/03/2023] [Accepted: 02/18/2023] [Indexed: 03/07/2023]
Abstract
PURPOSE We report findings from the first-in-human study of [11C]MDTC, a radiotracer developed to image the cannabinoid receptor type 2 (CB2R) with positron emission tomography (PET). METHODS Ten healthy adults were imaged according to a 90-min dynamic PET protocol after bolus intravenous injection of [11C]MDTC. Five participants also completed a second [11C]MDTC PET scan to assess test-retest reproducibility of receptor-binding outcomes. The kinetic behavior of [11C]MDTC in human brain was evaluated using tissue compartmental modeling. Four additional healthy adults completed whole-body [11C]MDTC PET/CT to calculate organ doses and the whole-body effective dose. RESULTS [11C]MDTC brain PET and [11C]MDTC whole-body PET/CT was well-tolerated. A murine study found evidence of brain-penetrant radiometabolites. The model of choice for fitting the time activity curves (TACs) across brain regions of interest was a three-tissue compartment model that includes a separate input function and compartment for the brain-penetrant metabolites. Regional distribution volume (VT) values were low, indicating low CB2R expression in the brain. Test-retest reliability of VT demonstrated a mean absolute variability of 9.91%. The measured effective dose of [11C]MDTC was 5.29 μSv/MBq. CONCLUSION These data demonstrate the safety and pharmacokinetic behavior of [11C]MDTC with PET in healthy human brain. Future studies identifying radiometabolites of [11C]MDTC are recommended before applying [11C]MDTC PET to assess the high expression of the CB2R by activated microglia in human brain.
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Affiliation(s)
- Yong Du
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, 601 N. Caroline St., JHOC 3223, Baltimore, MD, 21287, USA
| | - Jennifer M Coughlin
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins Medical Institutions, Baltimore, MD, 21287, USA
| | - Mary Katherine Brosnan
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, 601 N. Caroline St., JHOC 3223, Baltimore, MD, 21287, USA
| | - Allen Chen
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, 601 N. Caroline St., JHOC 3223, Baltimore, MD, 21287, USA
| | - Laura K Shinehouse
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, 601 N. Caroline St., JHOC 3223, Baltimore, MD, 21287, USA
| | - Rehab Abdallah
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, 601 N. Caroline St., JHOC 3223, Baltimore, MD, 21287, USA
| | - Martin A Lodge
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, 601 N. Caroline St., JHOC 3223, Baltimore, MD, 21287, USA
| | - William B Mathews
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, 601 N. Caroline St., JHOC 3223, Baltimore, MD, 21287, USA
| | - Chen Liu
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, 601 N. Caroline St., JHOC 3223, Baltimore, MD, 21287, USA
| | - Yunkou Wu
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, 601 N. Caroline St., JHOC 3223, Baltimore, MD, 21287, USA
| | - Il Minn
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, 601 N. Caroline St., JHOC 3223, Baltimore, MD, 21287, USA
| | - Paige Finley
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, 601 N. Caroline St., JHOC 3223, Baltimore, MD, 21287, USA
| | - Andrew W Hall
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, 601 N. Caroline St., JHOC 3223, Baltimore, MD, 21287, USA
| | - Wojciech G Lesniak
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, 601 N. Caroline St., JHOC 3223, Baltimore, MD, 21287, USA
| | - Robert F Dannals
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, 601 N. Caroline St., JHOC 3223, Baltimore, MD, 21287, USA
| | - Andrew G Horti
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, 601 N. Caroline St., JHOC 3223, Baltimore, MD, 21287, USA
| | - Martin G Pomper
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, 601 N. Caroline St., JHOC 3223, Baltimore, MD, 21287, USA.
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins Medical Institutions, Baltimore, MD, 21287, USA.
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5
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Fontana IC, Kumar A, Nordberg A. The role of astrocytic α7 nicotinic acetylcholine receptors in Alzheimer disease. Nat Rev Neurol 2023; 19:278-288. [PMID: 36977843 DOI: 10.1038/s41582-023-00792-4] [Citation(s) in RCA: 19] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/27/2023] [Indexed: 03/30/2023]
Abstract
The ongoing search for therapeutic interventions in Alzheimer disease (AD) has highlighted the complexity of this condition and the need for additional biomarkers, beyond amyloid-β (Aβ) and tau, to improve clinical assessment. Astrocytes are brain cells that control metabolic and redox homeostasis, among other functions, and are emerging as an important focus of AD research owing to their swift response to brain pathology in the initial stages of the disease. Reactive astrogliosis - the morphological, molecular and functional transformation of astrocytes during disease - has been implicated in AD progression, and the definition of new astrocytic biomarkers could help to deepen our understanding of reactive astrogliosis along the AD continuum. As we highlight in this Review, one promising biomarker candidate is the astrocytic α7 nicotinic acetylcholine receptor (α7nAChR), upregulation of which correlates with Aβ pathology in the brain of individuals with AD. We revisit the past two decades of research into astrocytic α7nAChRs to shed light on their roles in the context of AD pathology and biomarkers. We discuss the involvement of astrocytic α7nAChRs in the instigation and potentiation of early Aβ pathology and explore their potential as a target for future reactive astrocyte-based therapeutics and imaging biomarkers in AD.
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Affiliation(s)
- Igor C Fontana
- Division of Clinical Geriatrics, Center for Alzheimer Research, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Stockholm, Sweden
| | - Amit Kumar
- Division of Clinical Geriatrics, Center for Alzheimer Research, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Stockholm, Sweden
| | - Agneta Nordberg
- Division of Clinical Geriatrics, Center for Alzheimer Research, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Stockholm, Sweden.
- Theme Inflammation and Aging, Karolinska University Hospital, Stockholm, Sweden.
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6
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Tiepolt S, Meyer PM, Patt M, Deuther-Conrad W, Hesse S, Barthel H, Sabri O. PET Imaging of Cholinergic Neurotransmission in Neurodegenerative Disorders. J Nucl Med 2022; 63:33S-44S. [PMID: 35649648 DOI: 10.2967/jnumed.121.263198] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Revised: 05/06/2022] [Indexed: 12/13/2022] Open
Abstract
As a neuromodulator, the neurotransmitter acetylcholine plays an important role in cognitive, mood, locomotor, sleep/wake, and olfactory functions. In the pathophysiology of most neurodegenerative diseases, such as Alzheimer disease (AD) or Lewy body disorder (LBD), cholinergic receptors, transporters, or enzymes are involved and relevant as imaging targets. The aim of this review is to summarize current knowledge on PET imaging of cholinergic neurotransmission in neurodegenerative diseases. For PET imaging of presynaptic vesicular acetylcholine transporters (VAChT), (-)-18F-fluoroethoxybenzovesamicol (18F-FEOBV) was the first PET ligand that could be successfully translated to clinical application. Since then, the number of 18F-FEOBV PET investigations on patients with AD or LBD has grown rapidly and provided novel, important findings concerning the pathophysiology of AD and LBD. Regarding the α4β2 nicotinic acetylcholine receptors (nAChRs), various second-generation PET ligands, such as 18F-nifene, 18F-AZAN, 18F-XTRA, (-)-18F-flubatine, and (+)-18F-flubatine, were developed and successfully translated to human application. In neurodegenerative diseases such as AD and LBD, PET imaging of α4β2 nAChRs is of special value for monitoring disease progression and drugs directed to α4β2 nAChRs. For PET of α7 nAChR, 18F-ASEM and 11C-MeQAA were successfully applied in mild cognitive impairment and AD, respectively. The highest potential for α7 nAChR PET is seen in staging, in evaluating disease progression, and in therapy monitoring. PET of selective muscarinic acetylcholine receptors (mAChRs) is still in an early stage, as the development of subtype-selective radioligands is complicated. Promising radioligands to image mAChR subtypes M1 (11C-LSN3172176), M2 (18F-FP-TZTP), and M4 (11C-MK-6884) were developed and successfully translated to humans. PET imaging of mAChRs is relevant for the assessment and monitoring of therapies in AD and LBD. PET of acetylcholine esterase activity has been investigated since the 1990s. Many PET studies with 11C-PMP and 11C-MP4A demonstrated cortical cholinergic dysfunction in dementia associated with AD and LBD. Recent studies indicated a solid relationship between subcortical and cortical cholinergic dysfunction and noncognitive dysfunctions such as balance and gait in LBD. Taken together, PET of distinct components of cholinergic neurotransmission is of great interest for diagnosis, disease monitoring, and therapy monitoring and to gain insight into the pathophysiology of different neurodegenerative disorders.
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Affiliation(s)
- Solveig Tiepolt
- Department of Nuclear Medicine, University of Leipzig, Leipzig, Germany; and
| | - Philipp M Meyer
- Department of Nuclear Medicine, University of Leipzig, Leipzig, Germany; and
| | - Marianne Patt
- Department of Nuclear Medicine, University of Leipzig, Leipzig, Germany; and
| | | | - Swen Hesse
- Department of Nuclear Medicine, University of Leipzig, Leipzig, Germany; and
| | - Henryk Barthel
- Department of Nuclear Medicine, University of Leipzig, Leipzig, Germany; and
| | - Osama Sabri
- Department of Nuclear Medicine, University of Leipzig, Leipzig, Germany; and
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7
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Nag S, Miranda-Azpiazu P, Jia Z, Datta P, Arakawa R, Moein MM, Yang Z, Tu Y, Lemoine L, Ågren H, Nordberg A, Långström B, Halldin C. Development of 11C-Labeled ASEM Analogues for the Detection of Neuronal Nicotinic Acetylcholine Receptors (α7-nAChR). ACS Chem Neurosci 2022; 13:352-362. [PMID: 35020351 PMCID: PMC8815074 DOI: 10.1021/acschemneuro.1c00730] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
![]()
The
homo-pentameric
alpha 7 receptor is one of the major types
of neuronal nicotinic acetylcholine receptors (α7-nAChRs) related
to cognition, memory formation, and attention processing. The mapping
of α7-nAChRs by PET pulls a lot of attention to realize the
mechanism and development of CNS diseases such as AD, PD, and schizophrenia.
Several PET radioligands have been explored for the detection of the
α7-nAChR. 18F-ASEM is the most functional for in vivo quantification of α7-nAChRs in the human brain.
The first aim of this study was to initially use results from in silico
and machine learning techniques to prescreen and predict the binding
energy and other properties of ASEM analogues and to interpret these
properties in terms of atomic structures using 18F-ASEM
as a lead structure, and second, to label some selected candidates
with carbon-11/hydrogen-3 (11C/3H) and to evaluate
the binding properties in vitro and in vivo using the labeled candidates. In silico predictions are obtained
from perturbation free-energy calculations preceded by molecular docking,
molecular dynamics, and metadynamics simulations. Machine learning
techniques have been applied for the BBB and P-gp-binding properties.
Six analogues of ASEM were labeled with 11C, and three
of them were additionally labeled with 3H. Binding properties
were further evaluated using autoradiography (ARG) and PET measurements
in non-human primates (NHPs). Radiometabolites were measured in NHP
plasma. All six compounds were successfully synthesized. Evaluation
with ARG showed that 11C-Kln83 was preferably binding to
the α7-nAChR. Competition studies showed that 80% of the total
binding was displaced. Further ARG studies using 3H-KIn-83
replicated the preliminary results. In the NHP PET study, the distribution
pattern of 11C-KIn-83 was similar to other α7 nAChR
PET tracers. The brain uptake was relatively low and increased by
the administration of tariquidar, indicating a substrate of P-gp.
The ASEM blocking study showed that 11C-KIn-83 specifically
binds to α7 nAChRs. Preliminary in vitro evaluation
of KIn-83 by ARG with both 11C and 3H and in vivo evaluation in NHP showed favorable properties for
selectively imaging α7-nAChRs, despite a relatively low brain
uptake.
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Affiliation(s)
- Sangram Nag
- Department of Clinical Neuroscience, Centre for Psychiatry Research, Karolinska Institutet and Stockholm County Council, 171 76 Stockholm, Sweden
| | - Patricia Miranda-Azpiazu
- Department of Clinical Neuroscience, Centre for Psychiatry Research, Karolinska Institutet and Stockholm County Council, 171 76 Stockholm, Sweden
| | - Zhisheng Jia
- Department of Clinical Neuroscience, Centre for Psychiatry Research, Karolinska Institutet and Stockholm County Council, 171 76 Stockholm, Sweden
| | - Prodip Datta
- Department of Clinical Neuroscience, Centre for Psychiatry Research, Karolinska Institutet and Stockholm County Council, 171 76 Stockholm, Sweden
| | - Ryosuke Arakawa
- Department of Clinical Neuroscience, Centre for Psychiatry Research, Karolinska Institutet and Stockholm County Council, 171 76 Stockholm, Sweden
| | - Mohammad Mahdi Moein
- Department of Clinical Neuroscience, Centre for Psychiatry Research, Karolinska Institutet and Stockholm County Council, 171 76 Stockholm, Sweden
| | - Zhou Yang
- Department of Physics and Astronomy, Uppsala University, 751 20 Uppsala, Sweden
| | - Yaoquan Tu
- Division of Theoretical Chemistry and Biology, Royal Institute of Technology (KTH), 11428 Stockholm, Sweden
| | - Laetitia Lemoine
- Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, 141 52 Stockholm Sweden
| | - Hans Ågren
- Department of Physics and Astronomy, Uppsala University, 751 20 Uppsala, Sweden
| | - Agneta Nordberg
- Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, 141 52 Stockholm Sweden
- Theme Aging, Karolinska University Hospital, 141 52 Stockholm, Sweden
| | - Bengt Långström
- Department of Chemistry, Uppsala University, 75123 Uppsala, Sweden
| | - Christer Halldin
- Department of Clinical Neuroscience, Centre for Psychiatry Research, Karolinska Institutet and Stockholm County Council, 171 76 Stockholm, Sweden
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8
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Letsinger AC, Gu Z, Yakel JL. α7 nicotinic acetylcholine receptors in the hippocampal circuit: taming complexity. Trends Neurosci 2022; 45:145-157. [PMID: 34916082 PMCID: PMC8914277 DOI: 10.1016/j.tins.2021.11.006] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Revised: 11/04/2021] [Accepted: 11/19/2021] [Indexed: 02/03/2023]
Abstract
Cholinergic innervation of the hippocampus uses the neurotransmitter acetylcholine (ACh) to coordinate neuronal circuit activity while simultaneously influencing the function of non-neuronal cell types. The α7 nicotinic ACh receptor (nAChR) subtype is highly expressed throughout the hippocampus, has the highest calcium permeability compared with other subtypes of nAChRs, and is of high therapeutic interest due to its association with a variety of neurological disorders and neurodegenerative diseases. In this review, we synthesize research describing α7 nAChR properties, function, and relationship to cognitive dysfunction within the hippocampal circuit and highlight approaches to help improve therapeutic development.
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Affiliation(s)
- Ayland C. Letsinger
- Neurobiology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Department of Health and Human Services, Research Triangle Park, Mail Drop F2-08, P.O. Box 12233, Durham, NC, 27709, USA
| | - Zhenglin Gu
- Neurobiology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Department of Health and Human Services, Research Triangle Park, Mail Drop F2-08, P.O. Box 12233, Durham, NC, 27709, USA
| | - Jerrel L. Yakel
- Neurobiology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Department of Health and Human Services, Research Triangle Park, Mail Drop F2-08, P.O. Box 12233, Durham, NC, 27709, USA,Corresponding Author,
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9
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Cao L, Kong Y, Ji B, Ren Y, Guan Y, Ni R. Positron Emission Tomography in Animal Models of Tauopathies. Front Aging Neurosci 2022; 13:761913. [PMID: 35082657 PMCID: PMC8784812 DOI: 10.3389/fnagi.2021.761913] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2021] [Accepted: 11/30/2021] [Indexed: 12/18/2022] Open
Abstract
The microtubule-associated protein tau (MAPT) plays an important role in Alzheimer's disease and primary tauopathy diseases. The abnormal accumulation of tau contributes to the development of neurotoxicity, inflammation, neurodegeneration, and cognitive deficits in tauopathy diseases. Tau synergically interacts with amyloid-beta in Alzheimer's disease leading to detrimental consequence. Thus, tau has been an important target for therapeutics development for Alzheimer's disease and primary tauopathy diseases. Tauopathy animal models recapitulating the tauopathy such as transgenic, knock-in mouse and rat models have been developed and greatly facilitated the understanding of disease mechanisms. The advance in PET and imaging tracers have enabled non-invasive detection of the accumulation and spread of tau, the associated microglia activation, metabolic, and neurotransmitter receptor alterations in disease animal models. In vivo microPET studies on mouse or rat models of tauopathy have provided significant insights into the phenotypes and time course of pathophysiology of these models and allowed the monitoring of treatment targeting at tau. In this study, we discuss the utilities of PET and recently developed tracers for evaluating the pathophysiology in tauopathy animal models. We point out the outstanding challenges and propose future outlook in visualizing tau-related pathophysiological changes in brain of tauopathy disease animal models.
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Affiliation(s)
- Lei Cao
- Institute for Regenerative Medicine, University of Zurich, Zurich, Switzerland
- Changes Technology Corporation Ltd., Shanghai, China
| | - Yanyan Kong
- PET Center, Huashan Hospital, Fudan University, Shanghai, China
| | - Bin Ji
- Department of Radiopharmacy and Molecular Imaging, School of Pharmacy, Fudan University, Shanghai, China
| | - Yutong Ren
- Guangdong Robotics Association, Guangzhou, China
| | - Yihui Guan
- PET Center, Huashan Hospital, Fudan University, Shanghai, China
| | - Ruiqing Ni
- Institute for Regenerative Medicine, University of Zurich, Zurich, Switzerland
- Institute for Biomedical Engineering, ETH Zurich and University of Zurich, Zurich, Switzerland
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10
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Rigney G, Ayubcha C, Werner TJ, Alavi A, Revheim ME. The utility of PET imaging in the diagnosis and management of psychosis: a brief review. Clin Transl Imaging 2021. [DOI: 10.1007/s40336-021-00466-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Abstract
Purpose
Advances in the pathophysiological characterization of psychosis has led to a newfound role of biomarkers in diagnostic and prognostic contexts. Further, advances in the accuracy and sensitivity of nuclear medicine imaging techniques, and specifically positron emission tomography (PET), have improved the ability to diagnose and manage individuals experiencing first-episode psychosis or those at greater risk for developing psychosis.
Methods
Literature searches were performed in PubMed, Google Scholar, and Web of Science to identify papers related to the use of PET imaging in the diagnosis or management of psychosis. Search terms used included “positron emission tomography”, “PET imaging”, “psychosis”, “disorders of psychosis”, “schizophrenia”, “biomarkers”, “diagnostic biomarkers”, “prognostic biomarker”, “monitoring biomarker”, “outcome biomarker”, and “predictive biomarker.”
Results
Studies included fell into three categories: those examining microglia, those studying dopamine synthesis capacity, and those examining acetylcholine receptor activity. Microglial imaging has been shown to be ineffective in all patients with psychosis, but some believe it shows promise in a subset of patients with psychosis, although no defining characteristics of said subset have been postulated. Studies of dopamine synthesis capacity suggest that presynaptic dopamine is reliably elevated in patients with psychosis, but levels of dopamine active transporter are not. Further, positron emission tomography (PET) with [18F]fluoro-l-dihydroxyphenylalanine ([18F]FDOPA)-PET has been recently used successfully as a predictive biomarker of dopaminergic treatment response, although more work is needed to validate such findings. Finally, existing studies have also documented lower levels of binding to the α7 nicotinic cholinergic receptor (α7-nAChR) via [18F]-ASEM PET in patients with psychosis, however there is a dearth of prospective, randomized studies evaluating the efficacy of [18F]-ASEM as a diagnostic or monitoring biomarker of any kind.
Conclusion
Molecular imaging has become a useful tool in the diagnosis and management of psychosis. Further work must be done to improve the comparative prognostic value and diagnostic accuracy of different radiotracers.
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11
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Yang T, Wang D, Chen X, Liang Y, Guo F, Wu C, Jia L, Hou Z, Li W, He Z, Wang X. 18F-ASEM Imaging for Evaluating Atherosclerotic Plaques Linked to α7-Nicotinic Acetylcholine Receptor. Front Bioeng Biotechnol 2021; 9:684221. [PMID: 34277585 PMCID: PMC8280778 DOI: 10.3389/fbioe.2021.684221] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Accepted: 05/12/2021] [Indexed: 12/21/2022] Open
Abstract
Background Atherosclerosis is a chronic vascular inflammatory procedure alongside with lipid efflux disorder and foam cell formation. α7-Nicotinic acetylcholine receptor (α7nAChR) is a gated-calcium transmembrane channel widely expressed in neuron and non-neuron cells, such as monocytes and macrophages, activated T cells, dendritic cells, and mast cells. 18F-ASEM is an inhibitor targeted to α7nAChR that had been successfully applied in nervous system diseases. Previous studies had highlighted that α7nAChR was related to the emergency of vulnerable atherosclerotic plaques with excess inflammation cells. Thus, 18F-ASEM could be a complementary diagnostic approach to atherosclerotic plaques. Materials and Methods The synthesis of ASEM precursor and 18F-labeling had been performed successfully. We had established the ApoE–/– mice atherosclerotic plaques model (fed with western diet) and New Zealand rabbits atherosclerotic models (balloon-sprained experiment and western diet). After damage of endothelial cells and primary plaque formation, 18F-ASEM imaging of atherosclerotic plaques linked to α7nAChR had been conducted. In vivo micro-PET/CT imaging of ApoE–/– mice and the control group was performed 1 h after injection of 18F-ASEM (100–150 μCi); PET/CT imaging for rabbits with atherosclerotic plaques and control ones was also performed. Meanwhile, we also conducted CT scan on the abdominal aorta of these rabbits. After that, the animals were sacrificed, and the carotid and abdominal aorta were separately taken out for circular sections. The paraffin-embedded specimens were sectioned with 5 μm thickness and stained with hematoxylin–eosin (H&E) and oil red. Results In vivo vessel binding of 18F-ASEM and α7nAChR expression in the model group with atherosclerosis plaques was significantly higher than that in the control group. PET/CT imaging successfully identified the atherosclerotic plaques in ApoE–/– mice and model rabbits, whereas no obvious signals were detected in normal mice or rabbits. Compared with 18F-FDG, 18F-ASEM had more significant effect on the early monitoring of inflammation in carotid atherosclerotic plaques of ApoE–/– mice and model rabbits. 18F-ASEM had relatively more palpable effect on the imaging of abdominal aorta with atherosclerosis in rabbits. H&E and oil red staining identified the formation of atherosclerotic plaques in model animals, which provided pathological basis for the evaluation of imaging effects. Conclusion We first confirmed 18F-ASEM as radiotracer with good imaging properties for precise identification of atherosclerotic diseases.
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Affiliation(s)
- Tao Yang
- Department of Cardiovascular Surgery, Fu Wai Hospital, Cardiovascular Institute, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Dawei Wang
- Department of Nuclear Medicine, The Sixth Medical Center of PLA General Hospital, Beijing, China
| | - Xiangyi Chen
- Department of Nuclear Medicine, The First College of Clinical Medical Sciences, China Three Gorges University, Yichang, China.,Yichang Central People's Hospital, Yichang, China
| | - Yingkui Liang
- Department of Nuclear Medicine, The Sixth Medical Center of PLA General Hospital, Beijing, China
| | - Feng Guo
- Department of Nuclear Medicine, The Sixth Medical Center of PLA General Hospital, Beijing, China
| | - Chunxiao Wu
- Department of Cardiovascular Surgery, Fu Wai Hospital, Cardiovascular Institute, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Liujun Jia
- Department of Cardiovascular Surgery, Fu Wai Hospital, Cardiovascular Institute, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Zhihui Hou
- Department of Cardiovascular Surgery, Fu Wai Hospital, Cardiovascular Institute, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Wenliang Li
- School of Pharmacy, Jilin Medical University, Jilin City, China
| | - ZuoXiang He
- Department of Nuclear Medicine, Beijing Tsinghua Changgung Hospital, Tsinghua University, Beijing, China
| | - Xin Wang
- Department of Cardiovascular Surgery, Fu Wai Hospital, Cardiovascular Institute, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
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12
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Bao W, Xie F, Zuo C, Guan Y, Huang YH. PET Neuroimaging of Alzheimer's Disease: Radiotracers and Their Utility in Clinical Research. Front Aging Neurosci 2021; 13:624330. [PMID: 34025386 PMCID: PMC8134674 DOI: 10.3389/fnagi.2021.624330] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2020] [Accepted: 02/23/2021] [Indexed: 12/14/2022] Open
Abstract
Alzheimer's Disease (AD), the leading cause of senile dementia, is a progressive neurodegenerative disorder affecting millions of people worldwide and exerting tremendous socioeconomic burden on all societies. Although definitive diagnosis of AD is often made in the presence of clinical manifestations in late stages, it is now universally believed that AD is a continuum of disease commencing from the preclinical stage with typical neuropathological alterations appearing decades prior to its first symptom, to the prodromal stage with slight symptoms of amnesia (amnestic mild cognitive impairment, aMCI), and then to the terminal stage with extensive loss of basic cognitive functions, i.e., AD-dementia. Positron emission tomography (PET) radiotracers have been developed in a search to meet the increasing clinical need of early detection and treatment monitoring for AD, with reference to the pathophysiological targets in Alzheimer's brain. These include the pathological aggregations of misfolded proteins such as β-amyloid (Aβ) plagues and neurofibrillary tangles (NFTs), impaired neurotransmitter system, neuroinflammation, as well as deficient synaptic vesicles and glucose utilization. In this article we survey the various PET radiotracers available for AD imaging and discuss their clinical applications especially in terms of early detection and cognitive relevance.
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Affiliation(s)
- Weiqi Bao
- PET Center, Huanshan Hospital, Fudan University, Shanghai, China
| | - Fang Xie
- PET Center, Huanshan Hospital, Fudan University, Shanghai, China
| | - Chuantao Zuo
- PET Center, Huanshan Hospital, Fudan University, Shanghai, China
| | - Yihui Guan
- PET Center, Huanshan Hospital, Fudan University, Shanghai, China
| | - Yiyun Henry Huang
- Department of Radiology and Biomedical Imaging, PET Center, Yale University School of Medicine, New Haven, CT, United States
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13
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Chaney AM, Lopez-Picon FR, Serrière S, Wang R, Bochicchio D, Webb SD, Vandesquille M, Harte MK, Georgiadou C, Lawrence C, Busson J, Vercouillie J, Tauber C, Buron F, Routier S, Reekie T, Snellman A, Kassiou M, Rokka J, Davies KE, Rinne JO, Salih DA, Edwards FA, Orton LD, Williams SR, Chalon S, Boutin H. Prodromal neuroinflammatory, cholinergic and metabolite dysfunction detected by PET and MRS in the TgF344-AD transgenic rat model of AD: a collaborative multi-modal study. Am J Cancer Res 2021; 11:6644-6667. [PMID: 34093845 PMCID: PMC8171096 DOI: 10.7150/thno.56059] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Accepted: 02/15/2021] [Indexed: 12/25/2022] Open
Abstract
Mouse models of Alzheimer's disease (AD) are valuable but do not fully recapitulate human AD pathology, such as spontaneous Tau fibril accumulation and neuronal loss, necessitating the development of new AD models. The transgenic (TG) TgF344-AD rat has been reported to develop age-dependent AD features including neuronal loss and neurofibrillary tangles, despite only expressing APP and PSEN1 mutations, suggesting an improved modelling of AD hallmarks. Alterations in neuronal networks as well as learning performance and cognition tasks have been reported in this model, but none have combined a longitudinal, multimodal approach across multiple centres, which mimics the approaches commonly taken in clinical studies. We therefore aimed to further characterise the progression of AD-like pathology and cognition in the TgF344-AD rat from young-adults (6 months (m)) to mid- (12 m) and advanced-stage (18 m, 25 m) of the disease. Methods: TgF344-AD rats and wild-type (WT) littermates were imaged at 6 m, 12 m and 18 m with [18F]DPA-714 (TSPO, neuroinflammation), [18F]Florbetaben (Aβ) and [18F]ASEM (α7-nicotinic acetylcholine receptor) and with magnetic resonance spectroscopy (MRS) and with (S)-[18F]THK5117 (Tau) at 15 and 25 m. Behaviour tests were also performed at 6 m, 12 m and 18 m. Immunohistochemistry (CD11b, GFAP, Aβ, NeuN, NeuroChrom) and Tau (S)-[18F]THK5117 autoradiography, immunohistochemistry and Western blot were also performed. Results: [18F]DPA-714 positron emission tomography (PET) showed an increase in neuroinflammation in TG vs wildtype animals from 12 m in the hippocampus (+11%), and at the advanced-stage AD in the hippocampus (+12%), the thalamus (+11%) and frontal cortex (+14%). This finding coincided with strong increases in brain microgliosis (CD11b) and astrogliosis (GFAP) at these time-points as assessed by immunohistochemistry. In vivo [18F]ASEM PET revealed an age-dependent increase uptake in the striatum and pallidum/nucleus basalis of Meynert in WT only, similar to that observed with this tracer in humans, resulting in TG being significantly lower than WT by 18 m. In vivo [18F]Florbetaben PET scanning detected Aβ accumulation at 18 m, and (S)-[18F]THK5117 PET revealed subsequent Tau accumulation at 25m in hippocampal and cortical regions. Aβ plaques were low but detectable by immunohistochemistry from 6 m, increasing further at 12 and 18 m with Tau-positive neurons adjacent to Aβ plaques at 18 m. NeuroChrom (a pan neuronal marker) immunohistochemistry revealed a loss of neuronal staining at the Aβ plaques locations, while NeuN labelling revealed an age-dependent decrease in hippocampal neuron number in both genotypes. Behavioural assessment using the novel object recognition task revealed that both WT & TgF344-AD animals discriminated the novel from familiar object at 3 m and 6 m of age. However, low levels of exploration observed in both genotypes at later time-points resulted in neither genotype successfully completing the task. Deficits in social interaction were only observed at 3 m in the TgF344-AD animals. By in vivo MRS, we showed a decrease in neuronal marker N-acetyl-aspartate in the hippocampus at 18 m (-18% vs age-matched WT, and -31% vs 6 m TG) and increased Taurine in the cortex of TG (+35% vs age-matched WT, and +55% vs 6 m TG). Conclusions: This multi-centre multi-modal study demonstrates, for the first time, alterations in brain metabolites, cholinergic receptors and neuroinflammation in vivo in this model, validated by robust ex vivo approaches. Our data confirm that, unlike mouse models, the TgF344-AD express Tau pathology that can be detected via PET, albeit later than by ex vivo techniques, and is a useful model to assess and longitudinally monitor early neurotransmission dysfunction and neuroinflammation in AD.
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14
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Longitudinal PET Imaging of α7 Nicotinic Acetylcholine Receptors with [ 18F]ASEM in a Rat Model of Parkinson's Disease. Mol Imaging Biol 2021; 22:348-357. [PMID: 31286348 DOI: 10.1007/s11307-019-01400-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
PURPOSE The nicotinic acetylcholine alpha-7 receptors (α7R) are involved in a number of neuropsychiatric and neurodegenerative brain disorders such as Parkinson's disease (PD). However, their specific pathophysiologic roles are still unclear. In this context, we studied the evolution of these receptors in vivo by positron emission tomography (PET) imaging using the recently developed tracer 3-(1,4-diazabicyclo[3.2.2]nonan-4-yl)-6-[18F]fluorodibenzo[b,d]thiophene-5,5-dioxide) in a rat model mimicking early stages of PD. PROCEDURES PET imaging of α7R was performed at 3, 7, and 14 days following a partial striatal unilateral lesion with 6-hydroxydopamine in adult rats. After the last imaging experiments, the status of nigro-striatal dopamine neurons as well as different markers of neuroinflammation was evaluated on brain sections by autoradiographic and immunofluorescent experiments. RESULTS We showed an early and transitory rise in α7R expression in the lesioned striatum and substantia nigra, followed by over-expression of several gliosis activation markers in these regions of interest. CONCLUSIONS These findings support a longitudinally follow-up of α7R in animal models of PD and highlight the requirement to use a potential neuroprotective approach through α7R ligands at the early stages of PD.
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15
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Gamage R, Wagnon I, Rossetti I, Childs R, Niedermayer G, Chesworth R, Gyengesi E. Cholinergic Modulation of Glial Function During Aging and Chronic Neuroinflammation. Front Cell Neurosci 2020; 14:577912. [PMID: 33192323 PMCID: PMC7594524 DOI: 10.3389/fncel.2020.577912] [Citation(s) in RCA: 68] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Accepted: 09/07/2020] [Indexed: 12/12/2022] Open
Abstract
Aging is a complex biological process that increases the risk of age-related cognitive degenerative diseases such as dementia, including Alzheimer’s disease (AD), Lewy Body Dementia (LBD), and mild cognitive impairment (MCI). Even non-pathological aging of the brain can involve chronic oxidative and inflammatory stress, which disrupts the communication and balance between the brain and the immune system. There has been an increasingly strong connection found between chronic neuroinflammation and impaired memory, especially in AD. While microglia and astrocytes, the resident immune cells of the central nervous system (CNS), exerting beneficial effects during the acute inflammatory phase, during chronic neuroinflammation they can become more detrimental. Central cholinergic circuits are involved in maintaining normal cognitive function and regulating signaling within the entire cerebral cortex. While neuronal-glial cholinergic signaling is anti-inflammatory and anti-oxidative, central cholinergic neuronal degeneration is implicated in impaired learning, memory sleep regulation, and attention. Although there is evidence of cholinergic involvement in memory, fewer studies have linked the cholinergic anti-inflammatory and anti-oxidant pathways to memory processes during development, normal aging, and disease states. This review will summarize the current knowledge of cholinergic effects on microglia and astroglia, and their role in both anti-inflammatory and anti-oxidant mechanisms, concerning normal aging and chronic neuroinflammation. We provided details on how stimulation of α7 nicotinic acetylcholine (α7nACh) receptors can be neuroprotective by increasing amyloid-β phagocytosis, decreasing inflammation and reducing oxidative stress by promoting the nuclear factor erythroid 2-related factor 2 (Nrf2) pathways and decreasing the release of pro-inflammatory cytokines. There is also evidence for astroglial α7nACh receptor stimulation mediating anti-inflammatory and antioxidant effects by inhibiting the nuclear factor-κB (NF-κB) pathway and activating the Nrf2 pathway respectively. We conclude that targeting cholinergic glial interactions between neurons and glial cells via α7nACh receptors could regulate neuroinflammation and oxidative stress, relevant to the treatment of several neurodegenerative diseases.
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Affiliation(s)
- Rashmi Gamage
- Department of Pharmacology, School of Medicine, Western Sydney University, Penrith, NSW, Australia
| | - Ingrid Wagnon
- Department of Pharmacology, School of Medicine, Western Sydney University, Penrith, NSW, Australia
| | - Ilaria Rossetti
- Department of Pharmacology, School of Medicine, Western Sydney University, Penrith, NSW, Australia
| | - Ryan Childs
- Department of Pharmacology, School of Medicine, Western Sydney University, Penrith, NSW, Australia
| | - Garry Niedermayer
- School of Science, Western Sydney University, Penrith, NSW, Australia
| | - Rose Chesworth
- School of Medicine, Western Sydney University, Penrith, NSW, Australia
| | - Erika Gyengesi
- Department of Pharmacology, School of Medicine, Western Sydney University, Penrith, NSW, Australia
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16
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Du Y, Minn I, Foss C, Lesniak WG, Hu F, Dannals RF, Pomper MG, Horti AG. PET imaging of soluble epoxide hydrolase in non-human primate brain with [ 18F]FNDP. EJNMMI Res 2020; 10:67. [PMID: 32572592 PMCID: PMC7310027 DOI: 10.1186/s13550-020-00657-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Accepted: 06/09/2020] [Indexed: 02/07/2023] Open
Abstract
Purpose Soluble epoxide hydrolase (sEH) is a promising candidate positron emission tomography (PET) imaging biomarker altered in various disorders, including vascular cognitive impairment (VCI), Alzheimer’s disease (AD), Parkinson’s disease (PD), stroke, and depression, known to regulate levels of epoxyeicosatrienoic acids (EETs) and play an important role in neurovascular coupling. [18F]FNDP, a PET radiotracer for imaging sEH, was evaluated through quantitative PET imaging in the baboon brain, radiometabolite analysis, and radiation dosimetry estimate. Methods Baboon [18F]FNDP dynamic PET studies were performed at baseline and with blocking doses of the selective sEH inhibitor AR-9281 to evaluate sEH binding specificity. Radiometabolites of [18F]FNDP in mice and baboons were measured by high-performance liquid chromatography. Regional brain distribution volume (VT) of [18F]FNDP was computed from PET using radiometabolite-corrected arterial input functions. Full body distribution of [18F]FNDP was studied in CD-1 mice, and the human effective dose was estimated using OLINDA/EXM software. Results [18F]FNDP exhibited high and rapid brain uptake in baboons. AR-9281 blocked [18F]FNDP uptake dose-dependently with a baseline VT of 10.9 ± 2.4 mL/mL and a high-dose blocking VT of 1.0 ± 0.09 mL/mL, indicating substantial binding specificity (91.70 ± 1.74%). The VND was estimated as 0.865 ± 0.066 mL/mL. The estimated occupancy values of AR-9281 were 99.2 ± 1.1% for 1 mg/kg, 88.6 ± 1.3% for 0.1 mg/kg, and 33.8 ± 3.8% for 0.02 mg/kg. Murine biodistribution of [18F]FNDP enabled an effective dose estimate for humans (0.032 mSv/MBq). [18F]FNDP forms hydrophilic radiometabolites in murine and non-human primate plasma. However, only minute amounts of the radiometabolites entered the animal brain (< 2% in mice). Conclusions [18F]FNDP is a highly sEH-specific radiotracer that is suitable for quantitative PET imaging in the baboon brain. [18F]FNDP holds promise for translation to human subjects.
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Affiliation(s)
- Yong Du
- Division of Nuclear Medicine and Molecular Imaging, The Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, 601 North Caroline Street, JHOC 3223, Baltimore, MD, 21287, USA.
| | - Il Minn
- Division of Nuclear Medicine and Molecular Imaging, The Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, 601 North Caroline Street, JHOC 3223, Baltimore, MD, 21287, USA
| | - Catherine Foss
- Division of Nuclear Medicine and Molecular Imaging, The Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, 601 North Caroline Street, JHOC 3223, Baltimore, MD, 21287, USA
| | - Wojciech G Lesniak
- Division of Nuclear Medicine and Molecular Imaging, The Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, 601 North Caroline Street, JHOC 3223, Baltimore, MD, 21287, USA
| | - Feng Hu
- Division of Nuclear Medicine and Molecular Imaging, The Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, 601 North Caroline Street, JHOC 3223, Baltimore, MD, 21287, USA
| | - Robert F Dannals
- Division of Nuclear Medicine and Molecular Imaging, The Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, 601 North Caroline Street, JHOC 3223, Baltimore, MD, 21287, USA
| | - Martin G Pomper
- Division of Nuclear Medicine and Molecular Imaging, The Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, 601 North Caroline Street, JHOC 3223, Baltimore, MD, 21287, USA
| | - Andrew G Horti
- Division of Nuclear Medicine and Molecular Imaging, The Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, 601 North Caroline Street, JHOC 3223, Baltimore, MD, 21287, USA.
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17
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Donat CK, Hansen HH, Hansen HD, Mease RC, Horti AG, Pomper MG, L’Estrade ET, Herth MM, Peters D, Knudsen GM, Mikkelsen JD. In Vitro and In Vivo Characterization of Dibenzothiophene Derivatives [ 125I]Iodo-ASEM and [ 18F]ASEM as Radiotracers of Homo- and Heteromeric α7 Nicotinic Acetylcholine Receptors. Molecules 2020; 25:molecules25061425. [PMID: 32245032 PMCID: PMC7144377 DOI: 10.3390/molecules25061425] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2020] [Revised: 02/25/2020] [Accepted: 02/27/2020] [Indexed: 12/18/2022] Open
Abstract
The α7 nicotinic acetylcholine receptor (α7 nAChR) is involved in several cognitive and physiologic processes; its expression levels and patterns change in neurologic and psychiatric diseases, such as schizophrenia and Alzheimer’s disease, which makes it a relevant drug target. Development of selective radioligands is important for defining binding properties and occupancy of novel molecules targeting the receptor. We tested the in vitro binding properties of [125I]Iodo-ASEM [(3-(1,4-diazabycyclo[3.2.2]nonan-4-yl)-6-(125I-iododibenzo[b,d]thiopentene 5,5-dioxide)] in the mouse, rat and pig brain using autoradiography. The in vivo binding properties of [18F]ASEM were investigated using positron emission tomography (PET) in the pig brain. [125I]Iodo-ASEM showed specific and displaceable high affinity (~1 nM) binding in mouse, rat, and pig brain. Binding pattern overlapped with [125I]α-bungarotoxin, specific binding was absent in α7 nAChR gene-deficient mice and binding was blocked by a range of α7 nAChR orthosteric modulators in an affinity-dependent order in the pig brain. Interestingly, relative to the wild-type, binding in β2 nAChR gene-deficient mice was lower for [125I]Iodo-ASEM (58% ± 2.7%) than [125I]α-bungarotoxin (23% ± 0.2%), potentially indicating different binding properties to heteromeric α7β2 nAChR. [18F]ASEM PET in the pig showed high brain uptake and reversible tracer kinetics with a similar spatial distribution as previously reported for α7 nAChR. Blocking with SSR-180,711 resulted in a significant decrease in [18F]ASEM binding. Our findings indicate that [125I]Iodo-ASEM allows sensitive and selective imaging of α7 nAChR in vitro, with better signal-to-noise ratio than previous tracers. Preliminary data of [18F]ASEM in the pig brain demonstrated principal suitable kinetic properties for in vivo quantification of α7 nAChR, comparable to previously published data.
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Affiliation(s)
- Cornelius K. Donat
- Neurobiology Research Unit, Copenhagen University Hospital, Rigshospitalet, DK-2100 Copenhagen, Denmark; (H.H.H.); (H.D.H.); (E.T.L.); (G.M.K.)
- Department of Brain Sciences, Imperial College London, London W12 0 LS, UK
- Correspondence: (C.K.D.); (J.D.M.); Tel.: +45-40205378 (J.D.M)
| | - Henrik H. Hansen
- Neurobiology Research Unit, Copenhagen University Hospital, Rigshospitalet, DK-2100 Copenhagen, Denmark; (H.H.H.); (H.D.H.); (E.T.L.); (G.M.K.)
| | - Hanne D. Hansen
- Neurobiology Research Unit, Copenhagen University Hospital, Rigshospitalet, DK-2100 Copenhagen, Denmark; (H.H.H.); (H.D.H.); (E.T.L.); (G.M.K.)
| | - Ronnie C. Mease
- Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA; (R.C.M.); (A.G.H.); (M.G.P.)
| | - Andrew G. Horti
- Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA; (R.C.M.); (A.G.H.); (M.G.P.)
| | - Martin G. Pomper
- Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA; (R.C.M.); (A.G.H.); (M.G.P.)
| | - Elina T. L’Estrade
- Neurobiology Research Unit, Copenhagen University Hospital, Rigshospitalet, DK-2100 Copenhagen, Denmark; (H.H.H.); (H.D.H.); (E.T.L.); (G.M.K.)
- Department of Drug Design and Pharmacology, University of Copenhagen, Jagtvej 162, 2100 Copenhagen, Denmark;
- Department of Clinical Physiology, Nuclear Medicine & PET, Rigshospitalet, Blegdamsvej 9, 2100 Copenhagen, Denmark
| | - Matthias M. Herth
- Department of Drug Design and Pharmacology, University of Copenhagen, Jagtvej 162, 2100 Copenhagen, Denmark;
- Department of Clinical Physiology, Nuclear Medicine & PET, Rigshospitalet, Blegdamsvej 9, 2100 Copenhagen, Denmark
| | | | - Gitte M. Knudsen
- Neurobiology Research Unit, Copenhagen University Hospital, Rigshospitalet, DK-2100 Copenhagen, Denmark; (H.H.H.); (H.D.H.); (E.T.L.); (G.M.K.)
| | - Jens D. Mikkelsen
- Neurobiology Research Unit, Copenhagen University Hospital, Rigshospitalet, DK-2100 Copenhagen, Denmark; (H.H.H.); (H.D.H.); (E.T.L.); (G.M.K.)
- Correspondence: (C.K.D.); (J.D.M.); Tel.: +45-40205378 (J.D.M)
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18
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Coughlin JM, Rubin LH, Du Y, Rowe SP, Crawford JL, Rosenthal HB, Frey SM, Marshall ES, Shinehouse LK, Chen A, Speck CL, Wang Y, Lesniak WG, Minn I, Bakker A, Kamath V, Smith GS, Albert MS, Azad BB, Dannals RF, Horti A, Wong DF, Pomper MG. High Availability of the α7-Nicotinic Acetylcholine Receptor in Brains of Individuals with Mild Cognitive Impairment: A Pilot Study Using 18F-ASEM PET. J Nucl Med 2020; 61:423-426. [PMID: 31420499 PMCID: PMC9374031 DOI: 10.2967/jnumed.119.230979] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2019] [Accepted: 07/23/2019] [Indexed: 01/05/2023] Open
Abstract
Emerging evidence supports a hypothesized role for the α7-nicotinic acetylcholine receptor (α7-nAChR) in the pathophysiology of Alzheimer's disease. 18F-ASEM (3-(1,4-diazabicyclo[3.2.2]nonan-4-yl)-6-18F-fluorodibenzo[b,d]thiophene 5,5-dioxide) is a radioligand for estimating the availability of α7-nAChR in the brain in vivo with PET. Methods: In this cross-sectional study, 14 patients with mild cognitive impairment (MCI), a prodromal stage to dementia, and 17 cognitively intact, elderly controls completed 18F-ASEM PET. For each participant, binding in each region of interest was estimated using Logan graphical analysis with a metabolite-corrected arterial input function. Results: Higher 18F-ASEM binding was observed in MCI patients than in controls across all regions, supporting higher availability of α7-nAChR in MCI. 18F-ASEM binding was not associated with verbal memory in this small MCI sample. Conclusion: These data support use of 18F-ASEM PET to examine further the relationship between α7-nAChR availability and MCI.
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Affiliation(s)
- Jennifer M Coughlin
- Department of Psychiatry, Johns Hopkins Medical Institutions, Baltimore, Maryland
- Department of Radiology, Johns Hopkins Medical Institutions, Baltimore, Maryland
| | - Leah H Rubin
- Department of Psychiatry, Johns Hopkins Medical Institutions, Baltimore, Maryland
- Department of Neurology, Johns Hopkins Medical Institutions, Baltimore, Maryland
- Department of Epidemiology, Johns Hopkins Medical Institutions, Baltimore, Maryland; and
| | - Yong Du
- Department of Radiology, Johns Hopkins Medical Institutions, Baltimore, Maryland
| | - Steven P Rowe
- Department of Radiology, Johns Hopkins Medical Institutions, Baltimore, Maryland
| | - Jeffrey L Crawford
- Department of Psychiatry, Johns Hopkins Medical Institutions, Baltimore, Maryland
| | - Hailey B Rosenthal
- Department of Radiology, Johns Hopkins Medical Institutions, Baltimore, Maryland
| | - Sarah M Frey
- Department of Radiology, Johns Hopkins Medical Institutions, Baltimore, Maryland
| | - Erica S Marshall
- Department of Radiology, Johns Hopkins Medical Institutions, Baltimore, Maryland
| | - Laura K Shinehouse
- Department of Radiology, Johns Hopkins Medical Institutions, Baltimore, Maryland
| | - Allen Chen
- Department of Radiology, Johns Hopkins Medical Institutions, Baltimore, Maryland
| | - Caroline L Speck
- Department of Psychiatry, Johns Hopkins Medical Institutions, Baltimore, Maryland
| | - Yuchuan Wang
- Department of Radiology, Johns Hopkins Medical Institutions, Baltimore, Maryland
| | - Wojciech G Lesniak
- Department of Radiology, Johns Hopkins Medical Institutions, Baltimore, Maryland
| | - Il Minn
- Department of Radiology, Johns Hopkins Medical Institutions, Baltimore, Maryland
| | - Arnold Bakker
- Department of Psychiatry, Johns Hopkins Medical Institutions, Baltimore, Maryland
| | - Vidyulata Kamath
- Department of Psychiatry, Johns Hopkins Medical Institutions, Baltimore, Maryland
| | - Gwenn S Smith
- Department of Psychiatry, Johns Hopkins Medical Institutions, Baltimore, Maryland
- Department of Radiology, Johns Hopkins Medical Institutions, Baltimore, Maryland
| | - Marilyn S Albert
- Department of Neurology, Johns Hopkins Medical Institutions, Baltimore, Maryland
| | - Babak Behnam Azad
- Department of Radiology, Johns Hopkins Medical Institutions, Baltimore, Maryland
| | - Robert F Dannals
- Department of Radiology, Johns Hopkins Medical Institutions, Baltimore, Maryland
| | - Andrew Horti
- Department of Radiology, Johns Hopkins Medical Institutions, Baltimore, Maryland
| | - Dean F Wong
- Department of Psychiatry, Johns Hopkins Medical Institutions, Baltimore, Maryland
- Department of Radiology, Johns Hopkins Medical Institutions, Baltimore, Maryland
- Department of Neurology, Johns Hopkins Medical Institutions, Baltimore, Maryland
- Department of Neuroscience, Johns Hopkins Medical Institutions, Baltimore, Maryland
| | - Martin G Pomper
- Department of Psychiatry, Johns Hopkins Medical Institutions, Baltimore, Maryland
- Department of Radiology, Johns Hopkins Medical Institutions, Baltimore, Maryland
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19
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Coughlin JM, Horti AG, Pomper MG. Opportunities in precision psychiatry using PET neuroimaging in psychosis. Neurobiol Dis 2019; 131:104428. [PMID: 30904669 PMCID: PMC6744961 DOI: 10.1016/j.nbd.2019.03.016] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2018] [Revised: 03/15/2019] [Accepted: 03/19/2019] [Indexed: 12/21/2022] Open
Abstract
With the movement toward precision medicine in healthcare, recent studies of individuals with psychosis have begun to explore positron emission tomography (PET) as a tool to test for biochemical signatures that may distinguish subtypes of psychosis that guide subtype-specific therapeutic interventions. This review presents selected PET findings that exemplify early promise in using molecular imaging to predict treatment response, provide rationale for new therapeutic targets, and monitor target engagement in biomarker-defined subtypes of psychosis. PET data, among other data types, may prove useful in the scientific pursuit of identifying precision strategies to improve clinical outcomes for individuals with psychosis.
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Affiliation(s)
- Jennifer M Coughlin
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, USA; Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
| | - Andrew G Horti
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Martin G Pomper
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, USA; Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, MD, USA
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20
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Ouach A, Vercouillie J, Bertrand E, Rodrigues N, Pin F, Serriere S, Boiaryna L, Chartier A, Percina N, Tangpong P, Gulhan Z, Mothes C, Deloye JB, Guilloteau D, Page G, Suzenet F, Buron F, Chalon S, Routier S. Bis(het)aryl-1,2,3-triazole quinuclidines as α7 nicotinic acetylcholine receptor ligands: Synthesis, structure affinity relationships, agonism activity, [18F]-radiolabeling and PET study in rats. Eur J Med Chem 2019; 179:449-469. [DOI: 10.1016/j.ejmech.2019.06.049] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2019] [Revised: 06/16/2019] [Accepted: 06/17/2019] [Indexed: 12/12/2022]
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21
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Utkin YN. Aging Affects Nicotinic Acetylcholine Receptors in Brain. Cent Nerv Syst Agents Med Chem 2019; 19:119-124. [PMID: 30894113 DOI: 10.2174/1871524919666190320102834] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Revised: 02/28/2019] [Accepted: 03/08/2019] [Indexed: 06/09/2023]
Abstract
BACKGROUND Aging is a common and inevitable stage in the life cycle of higher organisms. Different organs, including the central nervous system, are affected by aging in different ways. Many processes are involved in aging, and neurodegeneration is one of the aging processes in which the central nervous system is engaged. Brain degeneration during normal aging underlies cognitive disorders experienced by older people. Not all molecular mechanisms associated with age-related neurodegeneration are fully understood; however, there is a whole range of data on the participation of nicotinic acetylcholine receptors in the processes of aging and neurodegeneration. Two main subtypes of nicotinic acetylcholine receptor α7 and α4β2 present in the central nervous system are affected by these processes. The loss of these receptor subtypes during normal aging is one of the reasons for the cognitive impairments. The decrease in nicotinic acetylcholine receptors is also very important for the pathogenesis of age-related neurodegenerative diseases. Thus, the drugs enhancing receptor functions may be considered promising for the treatment of cognitive dysfunction in the aged people. CONCLUSION To achieve healthy longevity, the molecular processes that occur during aging should be established. In this regard, the participation and role of nicotinic acetylcholine receptors in the brain aging and degeneration are considered in this review.
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Affiliation(s)
- Yuri N Utkin
- Laboratory of Molecular Toxinology, Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry RAS, Moscow, Russian Federation
- National University of Science and Technology MISIS, 119049 Moscow, Russian Federation
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22
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Coughlin J, Du Y, Crawford JL, Rubin LH, Behnam Azad B, Lesniak WG, Horti AG, Schretlen DJ, Sawa A, Pomper MG. The availability of the α7 nicotinic acetylcholine receptor in recent-onset psychosis: a study using 18F-ASEM PET. J Nucl Med 2018; 60:jnumed.118.213686. [PMID: 30573639 DOI: 10.2967/jnumed.118.213686] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2018] [Accepted: 05/31/2018] [Indexed: 11/16/2022] Open
Abstract
Limited postmortem evidence suggests a diminished availability of the α7 nicotinic acetylcholine receptor (α7-nAChR) in hippocampus in psychosis. Methods: In this cross-sectional PET study, we used 18F-ASEM, a radiotracer targeting the α7-nAChR, with positron emission tomography to compare the binding of 18F-ASEM in hippocampus between individuals with recent-onset psychosis and healthy controls. Results: Individuals with recent-onset psychosis [non-affective psychosis (NP) or affective psychosis], and particularly those with NP, showed lower hippocampal binding of 18F-ASEM than healthy controls. Among patients, lower binding was associated with lower performance in two cognitive domains after controlling for age. Conclusion: Low availability of the α7-nAChR in hippocampus may be linked to recent-onset of psychosis. Further study is needed to assess its clinical relationship to neuropsychiatric symptoms.
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Affiliation(s)
| | - Yong Du
- Johns Hopkins Medical Institutions, United States
| | | | - Leah H Rubin
- Johns Hopkins Medical Institutions, United States
| | | | | | | | | | - Akira Sawa
- Johns Hopkins Medical Institutions, United States
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23
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Teodoro R, Scheunemann M, Wenzel B, Peters D, Deuther-Conrad W, Brust P. Synthesis and radiofluorination of novel fluoren-9-one based derivatives for the imaging of α7 nicotinic acetylcholine receptor with PET. Bioorg Med Chem Lett 2018; 28:1471-1475. [PMID: 29628323 DOI: 10.1016/j.bmcl.2018.03.081] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2018] [Accepted: 03/29/2018] [Indexed: 12/15/2022]
Abstract
By structure-activity relationship studies on the tilorone scaffold, the 'one armed' substituted dibenzothiophenes and the fluoren-9-ones were identified as the most potential α7 nAChR ligands. While the suitability of dibenzothiophene derivatives as PET tracers is recognized, the potential of fluoren-9-ones is insufficiently investigated. We herein report on a series of fluoren-9-one based derivatives targeting α7 nAChR with compounds 8a and 8c possessing the highest affinity and selectivity. Accordingly, with [18F]8a and [18F]8c we designed and initially evaluated the first fluoren-9-one derived α7 nAChR selective PET ligands. A future application of these radioligands is facilitated by the herein presented successful implementation of fully automated radiosynthesis.
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Affiliation(s)
- Rodrigo Teodoro
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiopharmaceutical Cancer Research, Permoserstraße 15, Leipzig 04318, Germany.
| | - Matthias Scheunemann
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiopharmaceutical Cancer Research, Permoserstraße 15, Leipzig 04318, Germany
| | - Barbara Wenzel
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiopharmaceutical Cancer Research, Permoserstraße 15, Leipzig 04318, Germany
| | - Dan Peters
- DanPET AB, Rosenstigen 7, Malmö SE-21619, Sweden
| | - Winnie Deuther-Conrad
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiopharmaceutical Cancer Research, Permoserstraße 15, Leipzig 04318, Germany
| | - Peter Brust
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiopharmaceutical Cancer Research, Permoserstraße 15, Leipzig 04318, Germany
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24
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Wong DF, Kuwabara H, Horti AG, Roberts JM, Nandi A, Cascella N, Brasic J, Weerts EM, Kitzmiller K, Phan JA, Gapasin L, Sawa A, Valentine H, Wand G, Mishra C, George N, McDonald M, Lesniak W, Holt DP, Azad BB, Dannals RF, Kem W, Freedman R, Gjedde A. Brain PET Imaging of α7-nAChR with [18F]ASEM: Reproducibility, Occupancy, Receptor Density, and Changes in Schizophrenia. Int J Neuropsychopharmacol 2018; 21. [PMID: 29522184 PMCID: PMC6030963 DOI: 10.1093/ijnp/pyy021] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
BACKGROUND The α7 nicotinic acetylcholine receptor increasingly has been implicated in normal brain physiology, as well as in neuropsychiatric disorders. The highly cortical distribution of α7 nicotinic acetylcholine receptor suggests a role in cognition. METHODS We expanded the first-in-human PET imaging of α7 nicotinic acetylcholine receptor with [18F]ASEM from 5 to 21 healthy nonsmoking volunteers and added a feasibility study in 6 male patients with schizophrenia. Study aims included: (1) confirmation of test-retest reproducibility of [18F]ASEM binding, (2) demonstration of specificity by competition with DMXB-A, an α7 nicotinic acetylcholine receptor partial agonist, (3) estimation of [18F]ASEM binding potentials and α7 nicotinic acetylcholine receptor density in vivo in humans, and (4) demonstrating the feasibility of studying α7 nicotinic acetylcholine receptor as a target for schizophrenia. RESULTS Test-retest PET confirmed reproducibility (>90%) (variability ≤7%) of [18F]ASEM volume of distribution (VT) estimates in healthy volunteers. Repeated sessions of PET in 5 healthy subjects included baseline and effect of inhibition after oral administration of 150 mg DMXB-A. From reduction of binding potentials, we estimated the dose-dependent occupancy of α7 nicotinic acetylcholine receptor by DMXB-A at 17% to 49% for plasma concentrations at 60 to 200 nM DMXB-A. In agreement with evidence postmortem, α7 nicotinic acetylcholine receptor density averaged 0.67 to 0.82 nM and inhibitor affinity constant averaged 170 to 385 nM. Median VT in a feasibility study of 6 patients with schizophrenia was lower than in healthy volunteers in cingulate cortex, frontal cortex, and hippocampus (P = 0.02, corrected for multiple comparions, Mann-Whitney test). CONCLUSIONS The current results confirm the reproducibility of [18F]ASEM VT estimates and the specificity of the tracer for α7 nicotinic acetylcholine receptor. Preliminary findings from our feasibility study of [18F]ASEM binding in patients with schizophrenia are suggestive and provide guidance for future studies with more subjects.
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Affiliation(s)
- Dean F Wong
- Russell H. Morgan Department of Radiology and Radiological Sciences, Baltimore, Maryland,Department of Psychiatry and Behavioral Sciences, Baltimore, Maryland,Solomon Snyder Department of Neuroscience, Baltimore, Maryland,Department of Neurology, Baltimore, Maryland,Johns Hopkins University School of Medicine, Baltimore, Maryland,Correspondence: Dean F. Wong, MD, PhD, Radiology, Nuclear Medicine, Johns Hopkins Medical Institutions, JHOC Room 3244, Baltimore, MD ()
| | - Hiroto Kuwabara
- Russell H. Morgan Department of Radiology and Radiological Sciences, Baltimore, Maryland
| | - Andrew G Horti
- Russell H. Morgan Department of Radiology and Radiological Sciences, Baltimore, Maryland
| | - Joshua M Roberts
- Russell H. Morgan Department of Radiology and Radiological Sciences, Baltimore, Maryland
| | - Ayon Nandi
- Russell H. Morgan Department of Radiology and Radiological Sciences, Baltimore, Maryland
| | - Nicola Cascella
- Russell H. Morgan Department of Radiology and Radiological Sciences, Baltimore, Maryland,Sheppard-Pratt Hospital, Baltimore, Maryland
| | - James Brasic
- Russell H. Morgan Department of Radiology and Radiological Sciences, Baltimore, Maryland
| | - Elise M Weerts
- Department of Psychiatry and Behavioral Sciences, Baltimore, Maryland
| | - Kelly Kitzmiller
- Russell H. Morgan Department of Radiology and Radiological Sciences, Baltimore, Maryland
| | - Jenny A Phan
- Russell H. Morgan Department of Radiology and Radiological Sciences, Baltimore, Maryland,Department of Biomedicine, Aarhus University, Aarhus, Denmark,Department of Nuclear Medicine and PET Centre, Aarhus University Hospital, Aarhus, Denmark
| | - Lorena Gapasin
- Russell H. Morgan Department of Radiology and Radiological Sciences, Baltimore, Maryland
| | - Akira Sawa
- Department of Psychiatry and Behavioral Sciences, Baltimore, Maryland
| | - Heather Valentine
- Russell H. Morgan Department of Radiology and Radiological Sciences, Baltimore, Maryland
| | - Gary Wand
- Department of Psychiatry and Behavioral Sciences, Baltimore, Maryland,Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Chakradhar Mishra
- Russell H. Morgan Department of Radiology and Radiological Sciences, Baltimore, Maryland
| | - Noble George
- Russell H. Morgan Department of Radiology and Radiological Sciences, Baltimore, Maryland
| | - Michael McDonald
- Russell H. Morgan Department of Radiology and Radiological Sciences, Baltimore, Maryland
| | - Wojtek Lesniak
- Russell H. Morgan Department of Radiology and Radiological Sciences, Baltimore, Maryland
| | - Daniel P Holt
- Russell H. Morgan Department of Radiology and Radiological Sciences, Baltimore, Maryland
| | - Babak B Azad
- Russell H. Morgan Department of Radiology and Radiological Sciences, Baltimore, Maryland
| | - Robert F Dannals
- Russell H. Morgan Department of Radiology and Radiological Sciences, Baltimore, Maryland
| | - William Kem
- Russell H. Morgan Department of Radiology and Radiological Sciences, Baltimore, Maryland,Department of Pharmacology and Therapeutics, University of Florida, Gainesville, Florida
| | - Robert Freedman
- Department of Psychiatry, University of Colorado, Aurora, Colorado
| | - Albert Gjedde
- Russell H. Morgan Department of Radiology and Radiological Sciences, Baltimore, Maryland,Department of Nuclear Medicine, University of Southern Denmark, Odense, Denmark
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25
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Coughlin JM, Slania S, Du Y, Rosenthal HB, Lesniak WG, Minn I, Smith GS, Dannals RF, Kuwabara H, Wong DF, Wang Y, Horti AG, Pomper MG. 18F-XTRA PET for Enhanced Imaging of the Extrathalamic α4β2 Nicotinic Acetylcholine Receptor. J Nucl Med 2018; 59:1603-1608. [PMID: 29496987 DOI: 10.2967/jnumed.117.205492] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2017] [Accepted: 02/03/2018] [Indexed: 11/16/2022] Open
Abstract
Reduced density of the α4β2 nicotinic acetylcholine receptor (α4β2-nAChR) in the cortex and hippocampus of the human brain has been reported in aging and patients with neurodegenerative disease. This study assessed the pharmacokinetic behavior of 18F-(-)-JHU86428 (18F-XTRA), a new radiotracer for in vivo PET imaging of the α4β2-nAChR, particularly in extrathalamic regions of interest in which the α4β2-nAChR is less densely expressed than in thalamus. 18F-XTRA was also used to evaluate the α4β2-nAChR in the hippocampus in human aging. Methods: Seventeen healthy nonsmoker adults (11 men, 6 women; age, 30-82 y) underwent PET neuroimaging over 90 or 180 min in a high-resolution research tomograph after bolus injection of 18F-XTRA. Methods to quantify binding of 18F-XTRA to the α4β2-nAChR in the human brain were compared, and the relationship between age and binding in the hippocampus was tested. Results: 18F-XTRA rapidly entered the brain, and time-activity curves peaked within 10 min after injection for extrathalamic regions and at approximately 70 min in the thalamus. The 2-tissue-compartment model (2TCM) predicted the regional time-activity curves better than the 1-tissue-compartment model, and total distribution volume (VT) was well identified by the 2TCM in all ROIs. VT values estimated using Logan analysis with metabolite-corrected arterial input were highly correlated with those from the 2TCM in all regions, and values from 90-min scan duration were on average within 5% of those values from 180 min of data. Parametric images of VT were consistent with the known distribution of the α4β2-nAChR across the brain. Finally, an inverse correlation between VT in the hippocampus and age was observed. Conclusion: Our results extend support for use of 18F-XTRA with 90 min of emission scanning in quantitative human neuroimaging of the extrathalamic α4β2-nAChR, including in studies of aging.
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Affiliation(s)
- Jennifer M Coughlin
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins Medical Institutions, Baltimore, Maryland.,Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, Maryland
| | - Stephanie Slania
- Department of Biomedical Engineering, Johns Hopkins Medical Institutions, Baltimore, Maryland
| | - Yong Du
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, Maryland
| | - Hailey B Rosenthal
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, Maryland
| | - Wojciech G Lesniak
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, Maryland
| | - Il Minn
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, Maryland
| | - Gwenn S Smith
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins Medical Institutions, Baltimore, Maryland.,Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, Maryland
| | - Robert F Dannals
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, Maryland
| | - Hiroto Kuwabara
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, Maryland
| | - Dean F Wong
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins Medical Institutions, Baltimore, Maryland.,Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, Maryland.,Department of Neuroscience, Johns Hopkins Medical Institutions, Baltimore, Maryland; and.,Department of Neurology, Johns Hopkins Medical Institutions, Baltimore, Maryland
| | - Yuchuan Wang
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, Maryland
| | - Andrew G Horti
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, Maryland
| | - Martin G Pomper
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins Medical Institutions, Baltimore, Maryland .,Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, Maryland.,Department of Biomedical Engineering, Johns Hopkins Medical Institutions, Baltimore, Maryland
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Narayanaswami V, Dahl K, Bernard-Gauthier V, Josephson L, Cumming P, Vasdev N. Emerging PET Radiotracers and Targets for Imaging of Neuroinflammation in Neurodegenerative Diseases: Outlook Beyond TSPO. Mol Imaging 2018; 17:1536012118792317. [PMID: 30203712 PMCID: PMC6134492 DOI: 10.1177/1536012118792317] [Citation(s) in RCA: 117] [Impact Index Per Article: 19.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2018] [Revised: 05/31/2018] [Accepted: 07/09/2018] [Indexed: 11/16/2022] Open
Abstract
The dynamic and multicellular processes of neuroinflammation are mediated by the nonneuronal cells of the central nervous system, which include astrocytes and the brain's resident macrophages, microglia. Although initiation of an inflammatory response may be beneficial in response to injury of the nervous system, chronic or maladaptive neuroinflammation can have harmful outcomes in many neurological diseases. An acute neuroinflammatory response is protective when activated neuroglia facilitate tissue repair by releasing anti-inflammatory cytokines and neurotrophic factors. On the other hand, chronic neuroglial activation is a major pathological mechanism in neurodegenerative diseases, likely contributing to neuronal dysfunction, injury, and disease progression. Therefore, the development of specific and sensitive probes for positron emission tomography (PET) studies of neuroinflammation is attracting immense scientific and clinical interest. An early phase of this research emphasized PET studies of the prototypical imaging biomarker of glial activation, translocator protein-18 kDa (TSPO), which presents difficulties for quantitation and lacks absolute cellular specificity. Many alternate molecular targets present themselves for PET imaging of neuroinflammation in vivo, including enzymes, intracellular signaling molecules as well as ionotropic, G-protein coupled, and immunoglobulin receptors. We now review the lead structures in radiotracer development for PET studies of neuroinflammation targets for neurodegenerative diseases extending beyond TSPO, including glycogen synthase kinase 3, monoamine oxidase-B, reactive oxygen species, imidazoline-2 binding sites, cyclooxygenase, the phospholipase A2/arachidonic acid pathway, sphingosine-1-phosphate receptor-1, cannabinoid-2 receptor, the chemokine receptor CX3CR1, purinergic receptors: P2X7 and P2Y12, the receptor for advanced glycation end products, Mer tyrosine kinase, and triggering receptor expressed on myeloid cells-1. We provide a brief overview of the cellular expression and function of these targets, noting their selectivity for astrocytes and/or microglia, and highlight the classes of PET radiotracers that have been investigated in early-stage preclinical or clinical research studies of neuroinflammation.
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Affiliation(s)
- Vidya Narayanaswami
- Division of Nuclear Medicine and Molecular Imaging, Massachusetts General Hospital, Boston, MA, USA
- Azrieli Centre for Neuro-Radiochemistry, Research Imaging Centre, Centre for Addiction and Mental Health & Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada
| | - Kenneth Dahl
- Division of Nuclear Medicine and Molecular Imaging, Massachusetts General Hospital, Boston, MA, USA
- Azrieli Centre for Neuro-Radiochemistry, Research Imaging Centre, Centre for Addiction and Mental Health & Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada
- Department of Radiology, Harvard Medical School, Boston, MA, USA
| | - Vadim Bernard-Gauthier
- Division of Nuclear Medicine and Molecular Imaging, Massachusetts General Hospital, Boston, MA, USA
- Department of Radiology, Harvard Medical School, Boston, MA, USA
| | - Lee Josephson
- Division of Nuclear Medicine and Molecular Imaging, Massachusetts General Hospital, Boston, MA, USA
- Department of Radiology, Harvard Medical School, Boston, MA, USA
| | - Paul Cumming
- School of Psychology and Counselling and IHBI, Queensland University of Technology, Brisbane, Queensland, Australia
- QIMR Berghofer Medical Research Institute, Herston, Queensland, Australia
| | - Neil Vasdev
- Division of Nuclear Medicine and Molecular Imaging, Massachusetts General Hospital, Boston, MA, USA
- Azrieli Centre for Neuro-Radiochemistry, Research Imaging Centre, Centre for Addiction and Mental Health & Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada
- Department of Radiology, Harvard Medical School, Boston, MA, USA
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