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Mills KA, Du Y, Coughlin JM, Foss CA, Horti AG, Jenkins K, Skorobogatova Y, Spiro E, Motley CS, Dannals RF, Song JJ, Choi YR, Redding-Ochoa J, Troncoso J, Dawson VL, Kam TI, Pomper MG, Dawson TM. Exploring [ 11C]CPPC as a CSF1R-targeted PET Imaging Marker for Early Parkinson's Disease Severity. medRxiv 2024:2023.05.28.23290647. [PMID: 37398476 PMCID: PMC10312881 DOI: 10.1101/2023.05.28.23290647] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/04/2023]
Abstract
Neuroinflammation through enhanced innate immunity is thought play a role in the pathogenesis of Parkinson's disease (PD). Methods for monitoring neuroinflammation in living patients with PD are currently limited to positron emission tomography (PET) ligands that lack specificity in labeling immune cells in the nervous system. The colony stimulating factor 1 receptor (CSF1R) plays a crucial role in microglial function, an important cellular contributor to the nervous system's innate immune response. Using immunologic methods, we show that CSF1R in human brain is colocalized with the microglial marker, ionized calcium binding adaptor molecule 1 (Iba1). In PD, CSF1R immunoreactivity is significantly increased in PD across multiple brain regions, with the largest differences in the midbrain versus controls. Autoradiography revealed significantly increased [3H]JHU11761 binding in the inferior parietal cortex of PD patients. PET imaging demonstrated that higher [11C]CPPC binding in the striatum was associated with greater motor disability in PD. Furthermore, increased [11C]CPPC binding in various regions correlated with more severe motor disability and poorer verbal fluency. This study finds that CSF1R expression is elevated in PD and that [11C]CPPC-PET imaging of CSF1R is indicative of motor and cognitive impairments in the early stages of the disease. Moreover, the study underscores the significance of CSF1R as a promising biomarker for neuroinflammation in Parkinson's disease, suggesting its potential use for non-invasive assessment of disease progression and severity, leading to earlier diagnosis and targeted interventions.
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Affiliation(s)
- Kelly A Mills
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
| | - Yong Du
- Johns Hopkins University School of Medicine, Russell H. Morgan Dept. of Radiology and Radiologic Science, Baltimore, MD, USA
| | - Jennifer M Coughlin
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
| | - Catherine A Foss
- Johns Hopkins University School of Medicine, Russell H. Morgan Dept. of Radiology and Radiologic Science, Baltimore, MD, USA
| | - Andrew G Horti
- Johns Hopkins University School of Medicine, Russell H. Morgan Dept. of Radiology and Radiologic Science, Baltimore, MD, USA
| | - Katelyn Jenkins
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
| | - Yana Skorobogatova
- Johns Hopkins University School of Medicine, Russell H. Morgan Dept. of Radiology and Radiologic Science, Baltimore, MD, USA
| | - Ergi Spiro
- Johns Hopkins University School of Medicine, Russell H. Morgan Dept. of Radiology and Radiologic Science, Baltimore, MD, USA
| | - Chelsie S Motley
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
| | - Robert F Dannals
- Johns Hopkins University School of Medicine, Russell H. Morgan Dept. of Radiology and Radiologic Science, Baltimore, MD, USA
| | - Jae-Jin Song
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
- Neuroregeneration and Stem Cell Programs, Institute for Cell Engineering, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Yu Ree Choi
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
- Neuroregeneration and Stem Cell Programs, Institute for Cell Engineering, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Javier Redding-Ochoa
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
- Department of Pathology (Neuropathology), Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Juan Troncoso
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
- Department of Pathology (Neuropathology), Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Valina L Dawson
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
- Neuroregeneration and Stem Cell Programs, Institute for Cell Engineering, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
- Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Tae-In Kam
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
- Neuroregeneration and Stem Cell Programs, Institute for Cell Engineering, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Martin G Pomper
- Johns Hopkins University School of Medicine, Russell H. Morgan Dept. of Radiology and Radiologic Science, Baltimore, MD, USA
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
- Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, MD 21287, US
- Department of Radiology, University of Texas Southwestern School of Medicine, Dallas, TX, USA (current)
| | - Ted M Dawson
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
- Neuroregeneration and Stem Cell Programs, Institute for Cell Engineering, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
- Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, MD 21287, US
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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Rubin LH, Du Y, Sweeney SE, O’Toole R, Harrington CK, Jenkins K, Lesniak WG, Veenhuis RT, Dastgheyb R, Severson J, Fan H, Holt DP, Hall AW, Dannals RF, Horti AG, Pomper MG, Coughlin JM. Pilot imaging of the colony stimulating factor 1 receptor in the brains of virally-suppressed individuals with HIV. AIDS 2023; 37:1419-1424. [PMID: 37070549 PMCID: PMC10330113 DOI: 10.1097/qad.0000000000003572] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/19/2023]
Abstract
OBJECTIVE Neuroimmune activation is a putative driver of cognitive impairment in people with HIV (PWH), even in the age of modern antiretroviral therapy. Nevertheless, imaging of the microglial marker, the 18 kDa translocator protein (TSPO), with positron emission tomography (PET) in treated PWH has yielded inconclusive findings. One potential reason for the varied TSPO results is a lack of cell-type specificity of the TSPO target. DESIGN [ 11 C]CPPC, 5-cyano- N -(4-(4-[ 11 C]methylpiperazin-1-yl)-2-(piperidin-1-yl)phenyl) furan-2-carboxaminde, is a radiotracer for use with PET to image the colony stimulating factor 1 receptor (CSF1R). The CSF1R is expressed on microglia and central nervous system macrophages, with little expression on other cell types. We used [ 11 C]CPPC PET in virally-suppressed- (VS)-PWH and HIV-uninfected individuals to estimate the effect sizes of higher CSF1R in the brains of VS-PWH. METHODS Sixteen VS-PWH and 15 HIV-uninfected individuals completed [ 11 C]CPPC PET. [ 11 C]CPPC binding (V T ) in nine regions was estimated using a one-tissue compartmental model with a metabolite-corrected arterial input function, and compared between groups. RESULTS Regional [ 11 C]CPPC V T did not significantly differ between groups after age- and sex- adjustment [unstandardized beta coefficient ( B ) = 1.84, standard error (SE) = 1.18, P = 0.13]. The effect size was moderate [Cohen's d = 0.56, 95% confidence interval (CI) -0.16, 1.28), with strongest trend of higher V T in VS-PWH in striatum and parietal cortex (each P = 0.04; Cohen's d = 0.71 and 0.72, respectively). CONCLUSIONS A group difference in [ 11 C]CPPC V T was not observed between VS-PWH and HIV-uninfected individuals in this pilot, although the observed effect sizes suggest the study was underpowered to detect regional group differences in binding.
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Affiliation(s)
- Leah H. Rubin
- Department of Neurology, Johns Hopkins Medical Institutions, Baltimore, MD, USA
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins Medical Institutions, Baltimore, MD, USA
- Department of Epidemiology, Johns Hopkins Medical Institutions, Baltimore, MD, USA
- Molecular and Comparative Pathobiology, Johns Hopkins Medical Institutions, Baltimore, MD, USA
| | - Yong Du
- 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
| | - Riley O’Toole
- 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
| | - Katelyn Jenkins
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins Medical Institutions, Baltimore, MD, USA
| | - Wojciech G. Lesniak
- Department of Epidemiology, Johns Hopkins Medical Institutions, Baltimore, MD, USA
| | - Rebecca T. Veenhuis
- Department of Neurology, Johns Hopkins Medical Institutions, Baltimore, MD, USA
- Molecular and Comparative Pathobiology, Johns Hopkins Medical Institutions, Baltimore, MD, USA
| | - Raha Dastgheyb
- Department of Neurology, 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
| | - Daniel P. Holt
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, MD, USA
| | - Andrew W. Hall
- 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 G. Pomper
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins Medical Institutions, Baltimore, MD, USA
- Molecular and Comparative Pathobiology, Johns Hopkins Medical Institutions, Baltimore, MD, USA
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, MD, USA
| | - Jennifer M. Coughlin
- Department of Neurology, Johns Hopkins Medical Institutions, Baltimore, MD, USA
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins Medical Institutions, Baltimore, MD, USA
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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Foss CA, Ordonez AA, Naik R, Das D, Hall A, Wu Y, Dannals RF, Jain SK, Pomper MG, Horti AG. PET/CT imaging of CSF1R in a mouse model of tuberculosis. Eur J Nucl Med Mol Imaging 2022; 49:4088-4096. [PMID: 35713665 PMCID: PMC9922090 DOI: 10.1007/s00259-022-05862-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Accepted: 06/03/2022] [Indexed: 02/03/2023]
Abstract
PURPOSE Macrophages represent an essential means of sequestration and immune evasion for Mycobacterium tuberculosis. Pulmonary tuberculosis (TB) is characterized by dense collections of tissue-specific and recruited macrophages, both of which abundantly express CSF1R on their outer surface. 4-Cyano-N-(5-(1-(dimethylglycyl)piperidin-4-yl)-2',3',4',5'-tetrahydro-[1,1'-biphenyl]-2-yl)-1H-imidazole-2-carboxamide (JNJ-28312141) is a reported high affinity, CSF1R-selective antagonist. We report the radiosynthesis of 4-cyano-N-(5-(1-(N-methyl-N-([11C]methyl)glycyl)piperidin-4-yl)-2',3',4',5'-tetrahydro-[1,1'-biphenyl]-2-yl)-1H-imidazole-2-carboxamide ([11C]JNJ-28312141) and non-invasive detection of granulomatous and diffuse lesions in a mouse model of TB using positron emission tomography (PET). METHODS Nor-methyl-JNJ-28312141 precursor was radiolabeled with [11C]iodomethane to produce [11C]JNJ-28312141. PET/CT imaging was performed in the C3HeB/FeJ murine model of chronic pulmonary TB to co-localize radiotracer uptake with granulomatous lesions observed on CT. Additionally, CSF1R, Iba1 fluorescence immunohistochemistry was performed to co-localize CSF1R target with reactive macrophages in infected and healthy mice. RESULTS Radiosynthesis of [11C]JNJ-28312141 averaged a non-decay-corrected yield of 18.7 ± 2.1%, radiochemical purity of 99%, and specific activity averaging 658 ± 141 GBq/µmol at the end-of-synthesis. PET/CT imaging in healthy mice showed hepatobiliary [13.39-25.34% ID/g, percentage of injected dose per gram of tissue (ID/g)] and kidney uptake (12.35% ID/g) at 40-50 min post-injection. Infected mice showed focal pulmonary lesion uptake (5.58-12.49% ID/g), hepatobiliary uptake (15.30-40.50% ID/g), cervical node uptake, and renal uptake (11.66-29.33% ID/g). The ratio of infected lesioned lung/healthy lung uptake is 5.91:1, while the ratio of lesion uptake to adjacent infected radiolucent lung is 2.8:1. Pre-administration of 1 mg/kg of unlabeled JNJ-28312141 with [11C]JNJ-28312141 in infected animals resulted in substantial blockade. Fluorescence microscopy of infected and uninfected whole lung sections exclusively co-localized CSF1R staining with abundant Iba1 + macrophages. Healthy lung exhibited no CSF1R staining and very few Iba1 + macrophages. CONCLUSION [11C]JNJ-28312141 binds specifically to CSF1R + macrophages and delineates granulomatous foci of disease in a murine model of pulmonary TB.
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Affiliation(s)
- Catherine A Foss
- The Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University, Baltimore, MD, USA.
- Department of Pediatrics, Center for Infection and Inflammation Imaging Research, Baltimore, MD, USA.
| | - Alvaro A Ordonez
- Department of Pediatrics, Center for Infection and Inflammation Imaging Research, Baltimore, MD, USA
| | - Ravi Naik
- The Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University, Baltimore, MD, USA
| | - Deepankar Das
- The Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University, Baltimore, MD, USA
| | - Andrew Hall
- The Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University, Baltimore, MD, USA
| | - Yunkou Wu
- The Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University, Baltimore, MD, USA
| | - Robert F Dannals
- The Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University, Baltimore, MD, USA
| | - Sanjay K Jain
- The Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University, Baltimore, MD, USA
- Department of Pediatrics, Center for Infection and Inflammation Imaging Research, Baltimore, MD, USA
| | - Martin G Pomper
- The Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University, Baltimore, MD, USA
| | - Andrew G Horti
- The Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University, Baltimore, MD, USA
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Coughlin JM, Du Y, Lesniak WG, Harrington CK, Brosnan MK, O'Toole R, Zandi A, Sweeney SE, Abdallah R, Wu Y, Holt DP, Hall AW, Dannals RF, Solnes L, Horti AG, Pomper MG. First-in-human use of 11C-CPPC with positron emission tomography for imaging the macrophage colony-stimulating factor 1 receptor. EJNMMI Res 2022; 12:64. [PMID: 36175737 PMCID: PMC9522955 DOI: 10.1186/s13550-022-00929-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Accepted: 08/24/2022] [Indexed: 11/18/2022] Open
Abstract
Purpose Study of the contribution of microglia to onset and course of several neuropsychiatric conditions is challenged by the fact that these resident immune cells often take on different phenotypes and functions outside the living brain. Imaging microglia with radiotracers developed for use with positron emission tomography (PET) allows researchers to study these cells in their native tissue microenvironment. However, many relevant microglial imaging targets such as the 18 kDa translocator protein are also expressed on non-microglial cells, which can complicate the interpretation of PET findings. 11C-CPPC was developed to image the macrophage colony-stimulating factor 1 receptor, a target that is expressed largely by microglia relative to other cell types in the brain. Our prior work with 11C-CPPC demonstrated its high, specific uptake in brains of rodents and nonhuman primates with neuroinflammation, which supports the current first-in-human evaluation of its pharmacokinetic behavior in the brains of healthy individuals. Methods Eight healthy nonsmoker adults completed a 90-min dynamic PET scan that began with bolus injection of 11C-CPPC. Arterial blood sampling was collected in order to generate a metabolite-corrected arterial input function. Tissue time-activity curves (TACs) were generated using regions of interest identified from co-registered magnetic resonance imaging data. One- and two-tissue compartmental models (1TCM and 2TCM) as well as Logan graphical analysis were compared. Results Cortical and subcortical tissue TACs peaked by 37.5 min post-injection of 11C-CPPC and then declined. The 1TCM was preferred. Total distribution volume (VT) values computed from 1TCM aligned well with those from Logan graphical analysis (t* = 30), with VT values relatively high in thalamus, striatum, and most cortical regions, and with relatively lower VT in hippocampus, total white matter, and cerebellar cortex. Conclusion Our results extend support for the use of 11C-CPPC with PET to study microglia in the human brain. Supplementary Information The online version contains supplementary material available at 10.1186/s13550-022-00929-4.
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Affiliation(s)
- Jennifer M Coughlin
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins Medical Institutions, Baltimore, MD, USA.,Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, MD, USA
| | - Yong Du
- 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
| | - 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
| | - Riley O'Toole
- Department of Psychiatry and Behavioral Sciences, 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
| | - Shannon Eileen Sweeney
- 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
| | - Yunkou Wu
- 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
| | - Andrew W Hall
- 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
| | - Lilja Solnes
- 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 G Pomper
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins Medical Institutions, Baltimore, MD, USA. .,Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, MD, USA.
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7
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Coughlin JM, Slania S, Du Y, Shinehouse LK, Brosnan MK, Azad BB, Holt DP, Fan H, Lesniak WG, Minn I, Rowe SP, Dannals RF, Horti AG, Pomper MG. First-in-human neuroimaging of soluble epoxide hydrolase using [ 18F]FNDP PET. Eur J Nucl Med Mol Imaging 2021; 48:3122-3128. [PMID: 33585963 PMCID: PMC10129439 DOI: 10.1007/s00259-021-05231-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2020] [Accepted: 02/01/2021] [Indexed: 01/11/2023]
Abstract
PURPOSE Soluble epoxide hydrolase (sEH) is an enzyme with putative effect on neuroinflammation through its influence on the homeostasis of polyunsaturated fatty acids and related byproducts. sEH is an enzyme that metabolizes anti-inflammatory epoxy fatty acids to the corresponding, relatively inert 1,2-diols. A high availability or activity of sEH promotes vasoconstriction and inflammation in local tissues that may be linked to neuropsychiatric diseases. We developed [18F]FNDP to study sEH in vivo with positron emission tomography (PET). METHODS Brain PET using bolus injection of [18F]FNDP followed by emission imaging lasting 90 or 180 min was completed in healthy adults (5 males, 2 females, ages 40-53 years). The kinetic behavior of [18F]FNDP was evaluated using a radiometabolite-corrected arterial plasma input function with compartmental or graphical modeling approaches. RESULTS [18F]FNDP PET was without adverse effects. Akaike information criterion favored the two-tissue compartment model (2TCM) in all ten regions of interest. Regional total distribution volume (VT) values from each compartmental model and Logan analysis were generally well identified except for corpus callosum VT using the 2TCM. Logan analysis was assessed as the choice model due to stability of regional VT values from 90-min data and due to high correlation of Logan-derived regional VT values with those from the 2TCM. [18F]FNDP binding was higher in human cerebellar cortex and thalamus relative to supratentorial cortical regions, which aligns with reported expression patterns of the epoxide hydrolase 2 gene in human brain. CONCLUSION These data support further use of [18F]FNDP PET to study sEH in human brain.
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Affiliation(s)
- Jennifer M Coughlin
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins Medical Institutions, Baltimore, MD, USA.,Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, MD, USA
| | - Stephanie Slania
- Biomedical Engineering, Johns Hopkins Medical Institutions, Baltimore, MD, USA
| | - Yong Du
- 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
| | - Mary Katherine Brosnan
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, MD, USA
| | - Babak Behnam Azad
- 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
| | - Il Minn
- 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
| | - 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 G Pomper
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins Medical Institutions, Baltimore, MD, USA. .,Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, MD, USA. .,Biomedical Engineering, Johns Hopkins Medical Institutions, Baltimore, MD, USA.
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8
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Hu F, Morris PJ, Bonaventura J, Fan H, Mathews WB, Holt DP, Lam S, Boehm M, Dannals RF, Pomper MG, Michaelides M, Horti AG. 18F-labeled radiotracers for in vivo imaging of DREADD with positron emission tomography. Eur J Med Chem 2020; 213:113047. [PMID: 33280897 DOI: 10.1016/j.ejmech.2020.113047] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2020] [Revised: 11/08/2020] [Accepted: 11/21/2020] [Indexed: 12/17/2022]
Abstract
Designer Receptors Exclusively Activated by Designer Drugs (DREADD) are a preclinical chemogenetic approach with clinical potential for various disorders. In vivo visualization of DREADDs has been achieved with positron emission tomography (PET) using 11C radiotracers. The objective of this study was to develop DREADD radiotracers labeled with 18F for a longer isotope half-life. A series of non-radioactive fluorinated analogs of clozapine with a wide range of in vitro binding affinities for the hM3Dq and hM4Di DREADD receptors has been synthesized for PET. Compound [18F]7b was radiolabeled via a modified 18F-deoxyfluorination protocol with a commercial ruthenium reagent. [18F]7b demonstrated encouraging PET imaging properties in a DREADD hM3Dq transgenic mouse model, whereas the radiotracer uptake in the wild type mouse brain was low. [18F]7b is a promising long-lived alternative to the DREADD radiotracers [11C]clozapine ([11C]CLZ) and [11C]deschloroclozapine ([11C]DCZ).
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Affiliation(s)
- Feng Hu
- Division of Nuclear Medicine and Molecular Imaging, Department of Radiology, Johns Hopkins School of Medicine, Baltimore, MD, 21205, USA
| | - Patrick J Morris
- Division of Preclinical Innovation, National Center for Advancing Translational Sciences, National Institutes of Health, Rockville, MD, 20850, USA
| | - Jordi Bonaventura
- Biobehavioral Imaging and Molecular Neuropsychopharmacology Unit, National Institute on Drug Abuse Intramural Research Program, Baltimore, MD, 21224, USA
| | - Hong Fan
- Division of Nuclear Medicine and Molecular Imaging, Department of Radiology, Johns Hopkins School of Medicine, Baltimore, MD, 21205, USA
| | - William B Mathews
- Division of Nuclear Medicine and Molecular Imaging, Department of Radiology, Johns Hopkins School of Medicine, Baltimore, MD, 21205, USA
| | - Daniel P Holt
- Division of Nuclear Medicine and Molecular Imaging, Department of Radiology, Johns Hopkins School of Medicine, Baltimore, MD, 21205, USA
| | - Sherry Lam
- Biobehavioral Imaging and Molecular Neuropsychopharmacology Unit, National Institute on Drug Abuse Intramural Research Program, Baltimore, MD, 21224, USA
| | - Matthew Boehm
- Biobehavioral Imaging and Molecular Neuropsychopharmacology Unit, National Institute on Drug Abuse Intramural Research Program, Baltimore, MD, 21224, USA
| | - Robert F Dannals
- Division of Nuclear Medicine and Molecular Imaging, Department of Radiology, Johns Hopkins School of Medicine, Baltimore, MD, 21205, USA
| | - Martin G Pomper
- Division of Nuclear Medicine and Molecular Imaging, Department of Radiology, Johns Hopkins School of Medicine, Baltimore, MD, 21205, USA
| | - Michael Michaelides
- Biobehavioral Imaging and Molecular Neuropsychopharmacology Unit, National Institute on Drug Abuse Intramural Research Program, Baltimore, MD, 21224, USA; Department of Psychiatry and behavioral Sciences, Johns Hopkins School of Medicine, Baltimore, MD, 221205, USA
| | - Andrew G Horti
- Division of Nuclear Medicine and Molecular Imaging, Department of Radiology, Johns Hopkins School of Medicine, Baltimore, MD, 21205, USA.
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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10
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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Mathews WB, Wu Y, Horti AG, Naik R, Hall AW, Holt DP, Dannals RF. Radiosynthesis and validation of [5-cyano-N
-(4-(4-[11
C]methylpiperazin-1-yl)-2-(piperidin-1-yl)phenyl) furan-2-carboxamide] ([11
C]CPPC), a PET radiotracer for imaging CSF1R, a microglia-specific marker. J Labelled Comp Radiopharm 2019; 62:903-908. [DOI: 10.1002/jlcr.3806] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2019] [Revised: 09/06/2019] [Accepted: 09/10/2019] [Indexed: 11/06/2022]
Affiliation(s)
- William B. Mathews
- Division of Nuclear Medicine and Molecular Imaging, Department of Radiology; The Johns Hopkins University School of Medicine; Baltimore Maryland USA
| | - Yunkou Wu
- Division of Nuclear Medicine and Molecular Imaging, Department of Radiology; The Johns Hopkins University School of Medicine; Baltimore Maryland USA
| | - Andrew G. Horti
- Division of Nuclear Medicine and Molecular Imaging, Department of Radiology; The Johns Hopkins University School of Medicine; Baltimore Maryland USA
| | - Ravi Naik
- Division of Nuclear Medicine and Molecular Imaging, Department of Radiology; The Johns Hopkins University School of Medicine; Baltimore Maryland USA
| | - Andrew W. Hall
- Division of Nuclear Medicine and Molecular Imaging, Department of Radiology; The Johns Hopkins University School of Medicine; Baltimore Maryland USA
| | - Daniel P. Holt
- Division of Nuclear Medicine and Molecular Imaging, Department of Radiology; The Johns Hopkins University School of Medicine; Baltimore Maryland USA
| | - Robert F. Dannals
- Division of Nuclear Medicine and Molecular Imaging, Department of Radiology; The Johns Hopkins University School of Medicine; Baltimore Maryland USA
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12
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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13
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Bonaventura J, Eldridge MAG, Hu F, Gomez JL, Sanchez-Soto M, Abramyan AM, Lam S, Boehm MA, Ruiz C, Farrell MR, Moreno A, Galal Faress IM, Andersen N, Lin JY, Moaddel R, Morris PJ, Shi L, Sibley DR, Mahler SV, Nabavi S, Pomper MG, Bonci A, Horti AG, Richmond BJ, Michaelides M. High-potency ligands for DREADD imaging and activation in rodents and monkeys. Nat Commun 2019; 10:4627. [PMID: 31604917 PMCID: PMC6788984 DOI: 10.1038/s41467-019-12236-z] [Citation(s) in RCA: 93] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2019] [Accepted: 08/13/2019] [Indexed: 11/10/2022] Open
Abstract
Designer Receptors Exclusively Activated by Designer Drugs (DREADDs) are a popular chemogenetic technology for manipulation of neuronal activity in uninstrumented awake animals with potential for human applications as well. The prototypical DREADD agonist clozapine N-oxide (CNO) lacks brain entry and converts to clozapine, making it difficult to apply in basic and translational applications. Here we report the development of two novel DREADD agonists, JHU37152 and JHU37160, and the first dedicated 18F positron emission tomography (PET) DREADD radiotracer, [18F]JHU37107. We show that JHU37152 and JHU37160 exhibit high in vivo DREADD potency. [18F]JHU37107 combined with PET allows for DREADD detection in locally-targeted neurons, and at their long-range projections, enabling noninvasive and longitudinal neuronal projection mapping. Designer Receptors Exclusively Activated by Designer Drugs (DREADDs) are a powerful tool for neuroscience, but the standard DREADD ligand, CNO, has significant drawbacks. Here the authors report two novel high-potency DREADD ligands and a novel DREADD radiotracer for imaging purposes.
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Affiliation(s)
- Jordi Bonaventura
- Biobehavioral Imaging and Molecular Neuropsychopharmacology Unit, National Institute on Drug Abuse Intramural Research Program, Baltimore, MD, 21224, USA
| | - Mark A G Eldridge
- Laboratory of Neuropsychology, National Institute of Mental Health Intramural Research Program, Bethesda, MD, 20892, USA
| | - Feng Hu
- Department of Radiology Johns Hopkins School of Medicine, Baltimore, MD, 21205, USA
| | - Juan L Gomez
- Biobehavioral Imaging and Molecular Neuropsychopharmacology Unit, National Institute on Drug Abuse Intramural Research Program, Baltimore, MD, 21224, USA
| | - Marta Sanchez-Soto
- Molecular Neuropharmacology Section, National Institute of Neurological Disorders and Stroke Intramural Research Program, Bethesda, MD, 20814, USA
| | - Ara M Abramyan
- Computational Chemistry and Molecular Biophysics Unit, National Institute on Drug Abuse Intramural Research Program, Baltimore, MD, 21224, USA
| | - Sherry Lam
- Biobehavioral Imaging and Molecular Neuropsychopharmacology Unit, National Institute on Drug Abuse Intramural Research Program, Baltimore, MD, 21224, USA
| | - Matthew A Boehm
- Biobehavioral Imaging and Molecular Neuropsychopharmacology Unit, National Institute on Drug Abuse Intramural Research Program, Baltimore, MD, 21224, USA
| | - Christina Ruiz
- Department of Neurobiology & Behavior, University of California, Irvine, CA, 92697, USA
| | - Mitchell R Farrell
- Department of Neurobiology & Behavior, University of California, Irvine, CA, 92697, USA
| | - Andrea Moreno
- Department of Molecular Biology and Genetics, Dandrite, Aarhus University, 8000 Aarhus C, Aarhus, Denmark
| | - Islam Mustafa Galal Faress
- Department of Molecular Biology and Genetics, Dandrite, Aarhus University, 8000 Aarhus C, Aarhus, Denmark
| | - Niels Andersen
- Department of Molecular Biology and Genetics, Dandrite, Aarhus University, 8000 Aarhus C, Aarhus, Denmark
| | - John Y Lin
- School of Medicine, College of Health and Medicine, University of Tasmania, Tasmania, TAS, 7000, Australia
| | - Ruin Moaddel
- Laboratory of Clinical Investigation, National Institute on Aging Intramural Research Program, Baltimore, MD, 21224, USA
| | - Patrick J Morris
- National Center for Advancing Translational Sciences, Rockville, MD, 20850, USA
| | - Lei Shi
- Computational Chemistry and Molecular Biophysics Unit, National Institute on Drug Abuse Intramural Research Program, Baltimore, MD, 21224, USA
| | - David R Sibley
- Molecular Neuropharmacology Section, National Institute of Neurological Disorders and Stroke Intramural Research Program, Bethesda, MD, 20814, USA
| | - Stephen V Mahler
- Department of Neurobiology & Behavior, University of California, Irvine, CA, 92697, USA
| | - Sadegh Nabavi
- Department of Molecular Biology and Genetics, Dandrite, Aarhus University, 8000 Aarhus C, Aarhus, Denmark
| | - Martin G Pomper
- Department of Radiology Johns Hopkins School of Medicine, Baltimore, MD, 21205, USA
| | - Antonello Bonci
- Synaptic Plasticity Section, National Institute on Drug Abuse Intramural Research Program, Baltimore, MD, 21224, USA
| | - Andrew G Horti
- Department of Radiology Johns Hopkins School of Medicine, Baltimore, MD, 21205, USA.
| | - Barry J Richmond
- Laboratory of Neuropsychology, National Institute of Mental Health Intramural Research Program, Bethesda, MD, 20892, USA.
| | - Michael Michaelides
- Biobehavioral Imaging and Molecular Neuropsychopharmacology Unit, National Institute on Drug Abuse Intramural Research Program, Baltimore, MD, 21224, USA. .,Department of Psychiatry, Johns Hopkins School of Medicine, Baltimore, MD, 21205, USA.
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14
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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15
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Naik R, Valentine H, Dannals RF, Wong DF, Horti AG. Synthesis and Evaluation of a New 18F-Labeled Radiotracer for Studying the GABA B Receptor in the Mouse Brain. ACS Chem Neurosci 2018; 9:1453-1461. [PMID: 29498831 DOI: 10.1021/acschemneuro.8b00038] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
New GABAB agonists, fluoropyridyl ether analogues of baclofen, have been synthesized as potential PET radiotracers. The compound with highest inhibition binding affinity as well as greatest agonist response, ( R)-4-amino-3-(4-chloro-3-((2-fluoropyridin-4-yl)methoxy)phenyl)butanoic acid (1b), was radiolabeled with 18F with good radiochemical yield, high radiochemical purity, and high molar radioactivity. The regional brain distribution of the radiolabeled ( R)-4-amino-3-(4-chloro-3-((2-[18F]fluoropyridin-4-yl)methoxy)phenyl)butanoic acid, [18F]1b, was studied in CD-1 male mice. The study demonstrated that [18F]1b enters the mouse brain (1% ID/g tissue). The accumulation of [18F]1b in the mouse brain was inhibited (35%) by preinjection of GABAB agonist 1a, suggesting that the radiotracer brain uptake is partially mediated by GABAB receptors. The presented data demonstrate a feasibility of imaging of GABAB receptors in rodents and justify further development of GABAB PET tracers with improved specific binding and greater blood-brain barrier permeability.
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Affiliation(s)
- Ravi Naik
- Department of Radiology, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21287 United States
| | - Heather Valentine
- Department of Radiology, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21287 United States
| | - Robert F. Dannals
- Department of Radiology, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21287 United States
| | - Dean F. Wong
- Department of Radiology, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21287 United States
| | - Andrew G. Horti
- Department of Radiology, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21287 United States
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16
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Azad BB, Holt DP, Ravert HT, Horti AG, Dannals RF. An optimized radiosynthesis of [ 18 F]FNDP, a positron emission tomography radiotracer for imaging soluble epoxide hydrolase (sEH). J Labelled Comp Radiopharm 2018; 61:567-572. [PMID: 29529708 PMCID: PMC6574083 DOI: 10.1002/jlcr.3620] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2018] [Revised: 02/27/2018] [Accepted: 03/01/2018] [Indexed: 01/16/2023]
Abstract
In this concise practitioner protocol, the radiochemical synthesis of [18 F]FNDP suitable for human positron emission tomography studies is described and the results from validation productions are presented. The high specific activity radiotracer product is prepared as a sterile, apyrogenic solution that conforms to current Good Manufacturing Practice requirements.
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Affiliation(s)
- Babak Behnam Azad
- Division of Nuclear Medicine, Department of Radiology, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Daniel P Holt
- Division of Nuclear Medicine, Department of Radiology, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Hayden T Ravert
- Division of Nuclear Medicine, Department of Radiology, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Andrew G Horti
- Division of Nuclear Medicine, Department of Radiology, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Robert F Dannals
- Division of Nuclear Medicine, Department of Radiology, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
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17
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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: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [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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18
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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19
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Naik R, Valentine H, Hall A, Mathews WB, Harris JC, Carter CS, Dannals RF, Wong DF, Horti AG. Development of a radioligand for imaging V 1a vasopressin receptors with PET. Eur J Med Chem 2017; 139:644-656. [PMID: 28843869 DOI: 10.1016/j.ejmech.2017.08.037] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2017] [Revised: 08/15/2017] [Accepted: 08/16/2017] [Indexed: 10/19/2022]
Abstract
A series of vasopressin receptor V1a ligands have been synthesized for positron emission tomography (PET) imaging. The lead compound (1S,5R)-1 ((4-(1H-indol-3-yl)-3-methoxyphenyl) ((1S,5R)-1,3,3-trimethyl-6-azabicyclo[3.2.1]octan-6-yl)methanone) and its F-ethyl analog 6c exhibited the best combination of high binding affinity and optimal lipophilicity within the series. (1S,5R)-1 was radiolabeled with 11C for PET studies. [11CH3](1S,5R)-1 readily entered the mouse (4.7% ID/g tissue) and prairie vole brains (∼2% ID/g tissue) and specifically (30-34%) labeled V1a receptor. The common animal anesthetic Propofol significantly blocked the brain uptake of [11CH3](1S,5R)-1 in the mouse brain, whereas anesthetics Ketamine and Saffan increased the uptake variability. Future PET imaging studies with V1a radiotracers in non-human primates should be performed in awake animals or using anesthetics that do not affect the V1a receptor.
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Affiliation(s)
- Ravi Naik
- Department of Radiology, The Johns Hopkins University School of Medicine, Baltimore 21287, USA
| | - Heather Valentine
- Department of Radiology, The Johns Hopkins University School of Medicine, Baltimore 21287, USA
| | - Andrew Hall
- Department of Radiology, The Johns Hopkins University School of Medicine, Baltimore 21287, USA
| | - William B Mathews
- Department of Radiology, The Johns Hopkins University School of Medicine, Baltimore 21287, USA
| | - James C Harris
- Department of Radiology, The Johns Hopkins University School of Medicine, Baltimore 21287, USA
| | - C Sue Carter
- The Kinsey Institute, Indiana University, Bloomington, IN 47405, USA
| | - Robert F Dannals
- Department of Radiology, The Johns Hopkins University School of Medicine, Baltimore 21287, USA
| | - Dean F Wong
- Department of Radiology, The Johns Hopkins University School of Medicine, Baltimore 21287, USA
| | - Andrew G Horti
- Department of Radiology, The Johns Hopkins University School of Medicine, Baltimore 21287, USA.
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20
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Moldovan RP, Deuther-Conrad W, Horti AG, Brust P. Synthesis and Preliminary Biological Evaluation of Indol-3-yl-oxoacetamides as Potent Cannabinoid Receptor Type 2 Ligands. Molecules 2017; 22:molecules22010077. [PMID: 28054997 PMCID: PMC6155603 DOI: 10.3390/molecules22010077] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2016] [Revised: 12/22/2016] [Accepted: 12/22/2016] [Indexed: 11/22/2022] Open
Abstract
A small series of indol-3-yl-oxoacetamides was synthesized starting from the literature known N-(adamantan-1-yl)-2-(5-(furan-2-yl)-1-pentyl-1H-indol-3-yl)-2-oxoacetamide (5) by substituting the 1-pentyl-1H-indole subunit. Our preliminary biological evaluation showed that the fluorinated derivative 8 is a potent and selective CB2 ligand with Ki = 6.2 nM.
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Affiliation(s)
- Rareş-Petru Moldovan
- Helmholtz-Zentrum Dresden-Rossendorf e.V., Institute of Radiopharmaceutical Cancer Research, Permoserstr. 15, 04318 Leipzig, Germany.
| | - Winnie Deuther-Conrad
- Helmholtz-Zentrum Dresden-Rossendorf e.V., Institute of Radiopharmaceutical Cancer Research, Permoserstr. 15, 04318 Leipzig, Germany.
| | - Andrew G Horti
- Johns Hopkins School of Medicine, Division of Nuclear Medicine and Molecular Imaging, Department of Radiology, Baltimore, MD 21287, USA.
| | - Peter Brust
- Helmholtz-Zentrum Dresden-Rossendorf e.V., Institute of Radiopharmaceutical Cancer Research, Permoserstr. 15, 04318 Leipzig, Germany.
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21
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Tamborini L, Chen Y, Foss CA, Pinto A, Horti AG, Traynelis SF, De Micheli C, Mease RC, Hansen KB, Conti P, Pomper MG. Development of Radiolabeled Ligands Targeting the Glutamate Binding Site of the N-Methyl-d-aspartate Receptor as Potential Imaging Agents for Brain. J Med Chem 2016; 59:11110-11119. [PMID: 28002957 DOI: 10.1021/acs.jmedchem.6b01344] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Abnormal activity of various N-methyl-d-aspartate receptor (NMDAR) subtypes has been implicated in a wide variety of neurological disorders such as Alzheimer's disease, schizophrenia, and epilepsy. Imaging agents for PET and SPECT that target NMDARs in a subtype-selective fashion may enable better characterization of those disorders and enhance drug development. On the basis of a pyrazoline derivative that demonstrated neuroprotective effects in vivo, we synthesized a series of para-substituted analogues and measured their affinities to various NMDAR subtypes. Compounds 4a-c and 4e showed greater, nanomolar affinity for the GluN1/2A subtype versus GluN1/2B. Dicarbomethoxy (pro-drug) analogues of [124/125I]4d and [11C]4e (i.e., [124/125I]11d and [11C]11e) were generated and tested for NMDAR binding specificity in ex vivo autoradiography and brain biodistribution studies. Although NMDAR-specific binding could be demonstrated for [125I]11d and [11C]11e through autoradiography and biodistribution studies, imaging of neither [124I]11d nor [11C]11e could demonstrate brain penetration sufficient for detection by PET.
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Affiliation(s)
- Lucia Tamborini
- Department of Pharmaceutical Sciences, Università degli Studi di Milano , Via Mangiagalli 25, 20133 Milano, Italy
| | - Ying Chen
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical School , Baltimore, Maryland 21287, United States
| | - Catherine A Foss
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical School , Baltimore, Maryland 21287, United States
| | - Andrea Pinto
- Department of Pharmaceutical Sciences, Università degli Studi di Milano , Via Mangiagalli 25, 20133 Milano, Italy
| | - Andrew G Horti
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical School , Baltimore, Maryland 21287, United States
| | - Stephen F Traynelis
- Department of Pharmacology, Emory University School of Medicine , Atlanta, Georgia 30322, United States
| | - Carlo De Micheli
- Department of Pharmaceutical Sciences, Università degli Studi di Milano , Via Mangiagalli 25, 20133 Milano, Italy
| | - Ronnie C Mease
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical School , Baltimore, Maryland 21287, United States
| | - Kasper B Hansen
- Department of Biomedical & Pharmaceutical Sciences, University of Montana , 32 Campus Drive, Missoula, Montana 59812, United States
| | - Paola Conti
- Department of Pharmaceutical Sciences, Università degli Studi di Milano , Via Mangiagalli 25, 20133 Milano, Italy
| | - Martin G Pomper
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical School , Baltimore, Maryland 21287, United States
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22
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Moldovan RP, Teodoro R, Gao Y, Deuther-Conrad W, Kranz M, Wang Y, Kuwabara H, Nakano M, Valentine H, Fischer S, Pomper MG, Wong DF, Dannals RF, Brust P, Horti AG. Development of a High-Affinity PET Radioligand for Imaging Cannabinoid Subtype 2 Receptor. J Med Chem 2016; 59:7840-55. [PMID: 27500461 DOI: 10.1021/acs.jmedchem.6b00554] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Cannabinoid receptors type 2 (CB2) represent a target with increasing importance for neuroimaging due to its upregulation under various pathological conditions. Encouraged by preliminary results obtained with [(11)C](Z)-N-(3-(2-methoxyethyl)-4,5-dimethylthiazol-2(3H)-ylidene)-2,2,3,3-tetramethyl-cyclopropanecarboxamide ([(11)C]A-836339, [(11)C]1) in a mouse model of acute neuroinflammation (induced by lipopolysaccharide, LPS), we designed a library of fluorinated analogues aiming for an [(18)F]-labeled radiotracer with improved CB2 binding affinity and selectivity. Compound (Z)-N-(3-(4-fluorobutyl)-4,5-dimethylthiazol-2(3H)-ylidene)-2,2,3,3-tetramethyl-cyclopropanecarboxamide (29) was selected as the ligand with the highest CB2 affinity (Ki = 0.39 nM) and selectivity over those of CB1 (factor of 1000). [(18)F]29 was prepared starting from the bromo precursor (53). Specific binding was shown in vitro, whereas fast metabolism was observed in vivo in CD-1 mice. Animal PET revealed a brain uptake comparable to that of [(11)C]1. In the LPS-treated mice, a 20-30% higher uptake in brain was found in comparison to that in nontreated mice (n = 3, P < 0.05).
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Affiliation(s)
- Rareş-Petru Moldovan
- Helmholtz-Zentrum Dresden-Rossendorf e.V., Institute of Radiopharmaceutical Cancer Research , Leipzig, Germany
| | - Rodrigo Teodoro
- Helmholtz-Zentrum Dresden-Rossendorf e.V., Institute of Radiopharmaceutical Cancer Research , Leipzig, Germany
| | - Yongjun Gao
- Johns Hopkins School of Medicine , Department of Radiology, Baltimore, 21287 United States
| | - Winnie Deuther-Conrad
- Helmholtz-Zentrum Dresden-Rossendorf e.V., Institute of Radiopharmaceutical Cancer Research , Leipzig, Germany
| | - Mathias Kranz
- Helmholtz-Zentrum Dresden-Rossendorf e.V., Institute of Radiopharmaceutical Cancer Research , Leipzig, Germany
| | - Yuchuan Wang
- Johns Hopkins School of Medicine , Department of Radiology, Baltimore, 21287 United States
| | - Hiroto Kuwabara
- Johns Hopkins School of Medicine , Department of Radiology, Baltimore, 21287 United States
| | - Masayoshi Nakano
- Johns Hopkins School of Medicine , Department of Radiology, Baltimore, 21287 United States
| | - Heather Valentine
- Johns Hopkins School of Medicine , Department of Radiology, Baltimore, 21287 United States
| | - Steffen Fischer
- Helmholtz-Zentrum Dresden-Rossendorf e.V., Institute of Radiopharmaceutical Cancer Research , Leipzig, Germany
| | - Martin G Pomper
- Johns Hopkins School of Medicine , Department of Radiology, Baltimore, 21287 United States
| | - Dean F Wong
- Johns Hopkins School of Medicine , Department of Radiology, Baltimore, 21287 United States
| | - Robert F Dannals
- Johns Hopkins School of Medicine , Department of Radiology, Baltimore, 21287 United States
| | - Peter Brust
- Helmholtz-Zentrum Dresden-Rossendorf e.V., Institute of Radiopharmaceutical Cancer Research , Leipzig, Germany
| | - Andrew G Horti
- Johns Hopkins School of Medicine , Department of Radiology, Baltimore, 21287 United States
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Horti AG, Wang Y, Minn I, Lan X, Wang J, Koehler RC, Alkayed NJ, Dannals RF, Pomper MG. 18F-FNDP for PET Imaging of Soluble Epoxide Hydrolase. J Nucl Med 2016; 57:1817-1822. [PMID: 27417650 DOI: 10.2967/jnumed.116.173245] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2016] [Accepted: 05/16/2016] [Indexed: 12/29/2022] Open
Abstract
Soluble epoxide hydrolase (sEH) is a bifunctional enzyme located within cytosol and peroxisomes that converts epoxides to the corresponding diols and hydrolyzes phosphate monoesters. It serves to inactivate epoxyeicosatrienoic acids (EETs), which are generated in the brain to couple neuronal activity and cerebral blood flow in normal and pathologic states. Altered regulation of sEH was observed previously in various neuropathologic disorders including vascular dementia and stroke. Inhibitors of sEH are pursued as agents to mitigate neuronal damage after stroke. We developed N-(3,3-diphenylpropyl)-6-18F-fluoronicotinamide (18F-FNDP), which proved highly specific for imaging of sEH in the mouse and nonhuman primate brain with PET. METHODS 18F-FNDP was synthesized from the corresponding bromo precursor. sEH inhibitory activity of 18F-FNDP was measured using an sEH inhibitor screening assay kit. Biodistribution was undertaken in CD-1 mice. Binding specificity was assayed in CD-1 and sEH knock-out mice and Papio anubis (baboon) through pretreatment with an sEH inhibitor to block sEH binding. Dynamic PET imaging with arterial blood sampling was performed in 3 baboons, with regional tracer binding quantified using distribution volume. The metabolism of 18F-FNDP in baboons was assessed using high-performance liquid chromatography. RESULTS 18F-FNDP (inhibition binding affinity constant, 1.73 nM) was prepared in 1 step in a radiochemical yield of 14% ± 7%, specific radioactivity in the range of 888-3,774 GBq/μmol, and a radiochemical purity greater than 99% using an automatic radiosynthesis module. The time of preparation was about 75 min. In CD-1 mice, regional uptake followed the pattern of striatum > cortex > hippocampus > cerebellum, consistent with the known brain distribution of sEH, with 5.2% injected dose per gram of tissue at peak uptake. Blockade of 80%-90% was demonstrated in all brain regions. Minimal radiotracer uptake was present in sEH knock-out mice. PET baboon brain distribution paralleled that seen in mouse, with a marked blockade (95%) noted in all regions indicating sEH-mediated uptake of 18F-FNDP. Two hydrophilic metabolites were identified, with 20% parent compound present at 90 min after injection in baboon plasma. CONCLUSION 18F-FNDP can be synthesized in suitable radiochemical yield and high specific radioactivity and purity. In vivo imaging experiments demonstrated that 18F-FNDP targeted sEH in murine and nonhuman primate brain specifically. 18F-FNDP is a promising PET radiotracer likely to be useful for understanding the role of sEH in a variety of conditions affecting the central nervous system.
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Affiliation(s)
- Andrew G Horti
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, Maryland
| | - Yuchuan Wang
- 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
| | - Xi Lan
- Department of Neurology, Anesthesiology & Critical Care Medicine, Johns Hopkins Medical Institutions, Baltimore, Maryland; and
| | - Jian Wang
- Department of Neurology, Anesthesiology & Critical Care Medicine, Johns Hopkins Medical Institutions, Baltimore, Maryland; and
| | - Raymond C Koehler
- Department of Neurology, Anesthesiology & Critical Care Medicine, Johns Hopkins Medical Institutions, Baltimore, Maryland; and
| | - Nabil J Alkayed
- Department of Anesthesiology & Perioperative Medicine, Knight Cardiovascular Institute, Oregon Health & Science University, Portland, Oregon
| | - Robert F Dannals
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, Maryland
| | - Martin G Pomper
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, Maryland
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Horti AG, Wong DF. Clinical Perspective and Recent Development of PET Radioligands for Imaging Cerebral Nicotinic Acetylcholine Receptors. PET Clin 2016; 4:89-100. [PMID: 20046884 DOI: 10.1016/j.cpet.2009.04.014] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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25
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Horti AG. Development of [(18)F]ASEM, a specific radiotracer for quantification of the α7-nAChR with positron-emission tomography. Biochem Pharmacol 2015; 97:566-575. [PMID: 26232729 DOI: 10.1016/j.bcp.2015.07.030] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2015] [Accepted: 07/24/2015] [Indexed: 12/20/2022]
Abstract
The alpha-7 subtype of the nicotinic acetylcholine receptor (α7-nAChR) is fundamental to physiology; it mediates various brain functions and represents an important target for drug discovery. Exploration of the brain nicotinic acetylcholine receptors (nAChRs) using positron-emission tomography (PET) will make it possible to better understand the important role of this receptor and to study its involvement in schizophrenia, bipolar disorder, Alzheimer's and Parkinson's diseases, drug dependence, inflammation and many other disorders and simplify the development of nicotinic drugs for treatment of these disorders. Until recently, PET imaging of α7-nAChRs has been impeded by the absence of good radiotracers. This review describes various endeavors to develop α7-nAChR PET tracers by several research groups including the author's group. Most initial PET tracers for imaging α7-nAChRs did not exhibit suitable imaging properties due to their low specific binding. Newly discovered [(18)F]ASEM is the first highly specific α7-nAChR radioligand and in 2014 it was translated to human PET imaging.
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Affiliation(s)
- Andrew G Horti
- Department of Radiology, The Johns Hopkins School of Medicine, 600 North Wolfe Street, Baltimore, MD 21287-0816, USA.
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26
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Tuan EW, Horti AG, Olson TT, Gao Y, Stockmeier CA, Al-Muhtasib N, Bowman Dalley C, Lewin AE, Wolfe BB, Sahibzada N, Xiao Y, Kellar KJ. AT-1001 Is a Partial Agonist with High Affinity and Selectivity at Human and Rat α3β4 Nicotinic Cholinergic Receptors. Mol Pharmacol 2015; 88:640-9. [PMID: 26162864 DOI: 10.1124/mol.115.099978] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2015] [Accepted: 07/08/2015] [Indexed: 11/22/2022] Open
Abstract
AT-1001 [N-(2-bromophenyl)-9-methyl-9-azabicyclo[3.3.1] nonan-3-amine] is a high-affinity and highly selective ligand at α3β4 nicotinic cholinergic receptors (nAChRs) that was reported to decrease nicotine self-administration in rats. It was initially reported to be an antagonist at rat α3β4 nAChRs heterologously expressed in HEK293 cells. Here we compared AT-1001 actions at rat and human α3β4 and α4β2 nAChRs similarly expressed in HEK 293 cells. We found that, as originally reported, AT-1001 is highly selective for α3β4 receptors over α4β2 receptors, but its binding selectivity is much greater at human than at rat receptors, because of a higher affinity at human than at rat α3β4 nAChRs. Binding studies in human and rat brain and pineal gland confirmed the selectivity of AT-1001 for α3β4 nAChRs and its higher affinity for human compared with rat receptors. In patch-clamp electrophysiology studies, AT-1001 was a potent partial agonist with 65-70% efficacy at both human and rat α3β4 nAChRs. It was also a less potent and weaker (18%) partial agonist at α4β2 nAChRs. Both α3β4 and α4β2 nAChRs are upregulated by exposure of cells to AT-1001 for 3 days. Similarly, AT-1001 desensitized both receptor subtypes in a concentration-dependent manner, but it was 10 and 30 times more potent to desensitize human α3β4 receptors than rat α3β4 and human α4β2 receptors, respectively. After exposure to AT-1001, the time to recovery from desensitization was longest for the human α3β4 nAChR and shortest for the human α4β2 receptor, suggesting that recovery from desensitization is primarily related to the dissociation of the ligand from the receptor.
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Affiliation(s)
- Edward W Tuan
- Department of Pharmacology & Physiology, Georgetown University School of Medicine, Washington, DC (E.W.T., T.T.O., N.A.-M., C.B.D., A.E.L., B.B.W., N.S., Y.X., K.J.K.); Department of Radiology Division of Nuclear Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland (A.G.H., Y.G.); and Department of Psychiatry and Human Behavior, University of Mississippi Medical Center, Jackson, Mississippi (C.A.S.)
| | - Andrew G Horti
- Department of Pharmacology & Physiology, Georgetown University School of Medicine, Washington, DC (E.W.T., T.T.O., N.A.-M., C.B.D., A.E.L., B.B.W., N.S., Y.X., K.J.K.); Department of Radiology Division of Nuclear Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland (A.G.H., Y.G.); and Department of Psychiatry and Human Behavior, University of Mississippi Medical Center, Jackson, Mississippi (C.A.S.)
| | - Thao T Olson
- Department of Pharmacology & Physiology, Georgetown University School of Medicine, Washington, DC (E.W.T., T.T.O., N.A.-M., C.B.D., A.E.L., B.B.W., N.S., Y.X., K.J.K.); Department of Radiology Division of Nuclear Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland (A.G.H., Y.G.); and Department of Psychiatry and Human Behavior, University of Mississippi Medical Center, Jackson, Mississippi (C.A.S.)
| | - Yongiun Gao
- Department of Pharmacology & Physiology, Georgetown University School of Medicine, Washington, DC (E.W.T., T.T.O., N.A.-M., C.B.D., A.E.L., B.B.W., N.S., Y.X., K.J.K.); Department of Radiology Division of Nuclear Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland (A.G.H., Y.G.); and Department of Psychiatry and Human Behavior, University of Mississippi Medical Center, Jackson, Mississippi (C.A.S.)
| | - Craig A Stockmeier
- Department of Pharmacology & Physiology, Georgetown University School of Medicine, Washington, DC (E.W.T., T.T.O., N.A.-M., C.B.D., A.E.L., B.B.W., N.S., Y.X., K.J.K.); Department of Radiology Division of Nuclear Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland (A.G.H., Y.G.); and Department of Psychiatry and Human Behavior, University of Mississippi Medical Center, Jackson, Mississippi (C.A.S.)
| | - Nour Al-Muhtasib
- Department of Pharmacology & Physiology, Georgetown University School of Medicine, Washington, DC (E.W.T., T.T.O., N.A.-M., C.B.D., A.E.L., B.B.W., N.S., Y.X., K.J.K.); Department of Radiology Division of Nuclear Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland (A.G.H., Y.G.); and Department of Psychiatry and Human Behavior, University of Mississippi Medical Center, Jackson, Mississippi (C.A.S.)
| | - Carrie Bowman Dalley
- Department of Pharmacology & Physiology, Georgetown University School of Medicine, Washington, DC (E.W.T., T.T.O., N.A.-M., C.B.D., A.E.L., B.B.W., N.S., Y.X., K.J.K.); Department of Radiology Division of Nuclear Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland (A.G.H., Y.G.); and Department of Psychiatry and Human Behavior, University of Mississippi Medical Center, Jackson, Mississippi (C.A.S.)
| | - Amanda E Lewin
- Department of Pharmacology & Physiology, Georgetown University School of Medicine, Washington, DC (E.W.T., T.T.O., N.A.-M., C.B.D., A.E.L., B.B.W., N.S., Y.X., K.J.K.); Department of Radiology Division of Nuclear Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland (A.G.H., Y.G.); and Department of Psychiatry and Human Behavior, University of Mississippi Medical Center, Jackson, Mississippi (C.A.S.)
| | - Barry B Wolfe
- Department of Pharmacology & Physiology, Georgetown University School of Medicine, Washington, DC (E.W.T., T.T.O., N.A.-M., C.B.D., A.E.L., B.B.W., N.S., Y.X., K.J.K.); Department of Radiology Division of Nuclear Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland (A.G.H., Y.G.); and Department of Psychiatry and Human Behavior, University of Mississippi Medical Center, Jackson, Mississippi (C.A.S.)
| | - Niaz Sahibzada
- Department of Pharmacology & Physiology, Georgetown University School of Medicine, Washington, DC (E.W.T., T.T.O., N.A.-M., C.B.D., A.E.L., B.B.W., N.S., Y.X., K.J.K.); Department of Radiology Division of Nuclear Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland (A.G.H., Y.G.); and Department of Psychiatry and Human Behavior, University of Mississippi Medical Center, Jackson, Mississippi (C.A.S.)
| | - Yingxian Xiao
- Department of Pharmacology & Physiology, Georgetown University School of Medicine, Washington, DC (E.W.T., T.T.O., N.A.-M., C.B.D., A.E.L., B.B.W., N.S., Y.X., K.J.K.); Department of Radiology Division of Nuclear Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland (A.G.H., Y.G.); and Department of Psychiatry and Human Behavior, University of Mississippi Medical Center, Jackson, Mississippi (C.A.S.)
| | - Kenneth J Kellar
- Department of Pharmacology & Physiology, Georgetown University School of Medicine, Washington, DC (E.W.T., T.T.O., N.A.-M., C.B.D., A.E.L., B.B.W., N.S., Y.X., K.J.K.); Department of Radiology Division of Nuclear Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland (A.G.H., Y.G.); and Department of Psychiatry and Human Behavior, University of Mississippi Medical Center, Jackson, Mississippi (C.A.S.)
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27
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Wong DF, Kuwabara H, Pomper M, Holt DP, Brasic JR, George N, Frolov B, Willis W, Gao Y, Valentine H, Nandi A, Gapasin L, Dannals RF, Horti AG. Human brain imaging of α7 nAChR with [(18)F]ASEM: a new PET radiotracer for neuropsychiatry and determination of drug occupancy. Mol Imaging Biol 2015; 16:730-8. [PMID: 25145965 DOI: 10.1007/s11307-014-0779-3] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
PURPOSE Using the α7-nAChR radiotracer, [(18)F]ASEM, we present the first successful human positron emission tomography (PET) studies. Rodent occupancy with three clinically employed α7-nAChR drugs confirms the specificity of the radiotracer. PROCEDURES Five healthy male subjects were imaged for 90 min following IV [(18)F]ASEM. Two subjects were scanned for the second time (test/retest; TRV). Mouse biodistribution of [(18)F]ASEM was carried out in CD1 mice injected with using human equivalent doses of DMXB-A, EVP-6124, and varenicline to block specific binding. RESULTS [(18)F]ASEM readily entered the brain and peaked at 15 min post-injection with reversible kinetics and a peak %SUV of about 400 %. The regional human brain distribution of [(18)F]ASEM matched previous in vitro data and baboon PET results. The precuneus, parietal, occipital, cingulate cortexes, putamen, and thalamus showed high values of distribution volume (>20 ml/ml) and binding potentials >1 with TRV averaged 10.8 ± 5.1 %. In mouse distribution studies, there was significant dose-dependent blockade in the mouse brain with DMXB-A as well as the other two α7-nAChR drugs. CONCLUSIONS The characteristics of [(18)F]ASEM are consistent with the ability to quantify α7-nAChR in the human brain. [(18)F]ASEM is suitable for imaging neuropsychiatric disorders and target engagement (receptor occupancy) of potential α7-nAChR drugs.
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Affiliation(s)
- Dean F Wong
- Department of Radiology, School of Medicine, The Johns Hopkins University, Baltimore, MD, USA,
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Savonenko AV, Melnikova T, Wang Y, Ravert H, Gao Y, Koppel J, Lee D, Pletnikova O, Cho E, Sayyida N, Hiatt A, Troncoso J, Davies P, Dannals RF, Pomper MG, Horti AG. Cannabinoid CB2 Receptors in a Mouse Model of Aβ Amyloidosis: Immunohistochemical Analysis and Suitability as a PET Biomarker of Neuroinflammation. PLoS One 2015; 10:e0129618. [PMID: 26086915 PMCID: PMC4472959 DOI: 10.1371/journal.pone.0129618] [Citation(s) in RCA: 74] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2014] [Accepted: 05/11/2015] [Indexed: 11/18/2022] Open
Abstract
In Alzheimer's disease (AD), one of the early responses to Aβ amyloidosis is recruitment of microglia to areas of new plaque. Microglial receptors such as cannabinoid receptor 2 (CB2) might be a suitable target for development of PET radiotracers that could serve as imaging biomarkers of Aβ-induced neuroinflammation. Mouse models of amyloidosis (J20APPswe/ind and APPswe/PS1ΔE9) were used to investigate the cellular distribution of CB2 receptors. Specificity of CB2 antibody (H60) was confirmed using J20APPswe/ind mice lacking CB2 receptors. APPswe/PS1ΔE9 mice were used in small animal PET with a CB2-targeting radiotracer, [11C]A836339. These studies revealed increased binding of [11C]A836339 in amyloid-bearing mice. Specificity of the PET signal was confirmed in a blockade study with a specific CB2 antagonist, AM630. Confocal microscopy revealed that CB2-receptor immunoreactivity was associated with astroglial (GFAP) and, predominantly, microglial (CD68) markers. CB2 receptors were observed, in particular, in microglial processes forming engulfment synapses with Aβ plaques. In contrast to glial cells, neuron (NeuN)-derived CB2 signal was equal between amyloid-bearing and control mice. The pattern of neuronal CB2 staining in amyloid-bearing mice was similar to that in human cases of AD. The data collected in this study indicate that Aβ amyloidosis without concomitant tau pathology is sufficient to activate CB2 receptors that are suitable as an imaging biomarker of neuroinflammation. The main source of enhanced CB2 PET binding in amyloid-bearing mice is increased CB2 immunoreactivity in activated microglia. The presence of CB2 immunoreactivity in neurons does not likely contribute to the enhanced CB2 PET signal in amyloid-bearing mice due to a lack of significant neuronal loss in this model. However, significant loss of neurons as seen at late stages of AD might decrease the CB2 PET signal due to loss of neuronally-derived CB2. Thus this study in mouse models of AD indicates that a CB2-specific radiotracer can be used as a biomarker of neuroinflammation in the early preclinical stages of AD, when no significant neuronal loss has yet developed.
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Affiliation(s)
- Alena V. Savonenko
- Department of Pathology, The Johns Hopkins University School of Medicine, Baltimore, MD, United States of America
- Departments of Neurology, The Johns Hopkins University School of Medicine, Baltimore, MD, United States of America
- * E-mail: (AGH); (AS)
| | - Tatiana Melnikova
- Department of Pathology, The Johns Hopkins University School of Medicine, Baltimore, MD, United States of America
| | - Yuchuan Wang
- Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, MD, United States of America
| | - Hayden Ravert
- Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, MD, United States of America
| | - Yongjun Gao
- Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, MD, United States of America
| | - Jeremy Koppel
- Litwin-Zucker Research Center, Feinstein Institute for Medical Research, North-Shore Long Island Jewish Health System, Manhasset, NY, United States of America
| | - Deidre Lee
- Department of Pathology, The Johns Hopkins University School of Medicine, Baltimore, MD, United States of America
| | - Olga Pletnikova
- Department of Pathology, The Johns Hopkins University School of Medicine, Baltimore, MD, United States of America
| | - Eugenia Cho
- Department of Pathology, The Johns Hopkins University School of Medicine, Baltimore, MD, United States of America
| | - Nuzhat Sayyida
- Department of Pathology, The Johns Hopkins University School of Medicine, Baltimore, MD, United States of America
| | - Andrew Hiatt
- MAPP Biopharmaceutical Inc, San-Diego, CA, United States of America
| | - Juan Troncoso
- Department of Pathology, The Johns Hopkins University School of Medicine, Baltimore, MD, United States of America
- Departments of Neurology, The Johns Hopkins University School of Medicine, Baltimore, MD, United States of America
| | - Peter Davies
- Litwin-Zucker Research Center, Feinstein Institute for Medical Research, North-Shore Long Island Jewish Health System, Manhasset, NY, United States of America
| | - Robert F. Dannals
- Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, MD, United States of America
| | - Martin G. Pomper
- Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, MD, United States of America
| | - Andrew G. Horti
- Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, MD, United States of America
- * E-mail: (AGH); (AS)
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Ravert HT, Holt DP, Gao Y, Horti AG, Dannals RF. Microwave-assisted radiosynthesis of [(18) F]ASEM, a radiolabeled α7-nicotinic acetylcholine receptor antagonist. J Labelled Comp Radiopharm 2015; 58:180-2. [PMID: 25720955 DOI: 10.1002/jlcr.3275] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2014] [Revised: 01/14/2015] [Accepted: 01/18/2015] [Indexed: 11/07/2022]
Abstract
An improvement of the original radiochemical synthesis of [(18) F]ASEM, an α7-nicotinic acetylcholinergic receptor radioligand, is reported. The new procedure utilizes microwave-assisted radiofluorination. In addition, a new preparative HPLC method was developed to eliminate a chemical impurity in the final product. Quality control procedures were also enhanced to improve detection of product with enhanced resolution of potential impurities. [(18) F]ASEM was produced in 20.1 ± 8.9% non-decay corrected (NDC) yield with an average synthesis time of 57 min and an average specific radioactivity of 856 ± 332 GBq/µmol (23 ± 9 Ci/µmol).
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Affiliation(s)
- Hayden T Ravert
- Division of Nuclear Medicine, Department of Radiology, The Johns Hopkins University School of Medicine, 600 North Wolfe Street, Nelson B1-152, Baltimore, MD, 21287, USA
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Volk DW, Eggan SM, Horti AG, Wong DF, Lewis DA. Reciprocal alterations in cortical cannabinoid receptor 1 binding relative to protein immunoreactivity and transcript levels in schizophrenia. Schizophr Res 2014; 159:124-9. [PMID: 25107849 PMCID: PMC4177350 DOI: 10.1016/j.schres.2014.07.017] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/03/2014] [Revised: 07/08/2014] [Accepted: 07/09/2014] [Indexed: 11/18/2022]
Abstract
The deleterious effects of cannabis use in schizophrenia have been linked, in part, to underlying disturbances in endogenous cannabinoid signaling in the prefrontal cortex. However, while receptor autoradiography studies of the primary cannabinoid receptor (CB1R) have consistently found higher CB1R binding in the prefrontal cortex in schizophrenia, deficits in CB1R mRNA levels and protein immunoreactivity have also been reported in the illness. To investigate this apparent discrepancy, we quantified CB1R binding using receptor autoradiography with the selective CB1R ligand [(3)H]-OMAR in the prefrontal cortex of 21 subjects with schizophrenia who were previously found to have lower levels of both CB1R mRNA using in situ hybridization and CB1R protein using radioimmunocytochemistry relative to matched healthy comparison subjects. We observed higher levels of [(3)H]-OMAR binding in the prefrontal cortex of schizophrenia subjects that did not appear to be attributable to psychotropic medications or substance abuse. The combination of lower levels of CB1R mRNA and immunoreactivity with higher CB1R receptor binding may reflect 1) altered trafficking of the receptor resulting in higher levels of membrane-bound CB1R or 2) higher CB1R affinity. In either case, greater CB1R receptor availability may contribute to the increased susceptibility of schizophrenia subjects to the deleterious effects of cannabis use.
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Affiliation(s)
- David W Volk
- Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA 15213, United States.
| | - Stephen M Eggan
- Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA 15213, United States
| | - Andrew G Horti
- Department of Radiology, Johns Hopkins University, Baltimore, MD 21287, United States
| | - Dean F Wong
- Department of Radiology, Johns Hopkins University, Baltimore, MD 21287, United States; Department of Psychiatry, Johns Hopkins University, Baltimore, MD 21287, United States; Department of Neuroscience, Johns Hopkins University, Baltimore, MD 21287, United States
| | - David A Lewis
- Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA 15213, United States; Department of Neuroscience, University of Pittsburgh, Pittsburgh, PA 15213, United States
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Horti AG, Gao Y, Kuwabara H, Wang Y, Abazyan S, Yasuda RP, Tran T, Xiao Y, Sahibzada N, Holt DP, Kellar KJ, Pletnikov MV, Pomper MG, Wong DF, Dannals RF. 18F-ASEM, a radiolabeled antagonist for imaging the α7-nicotinic acetylcholine receptor with PET. J Nucl Med 2014; 55:672-7. [PMID: 24556591 DOI: 10.2967/jnumed.113.132068] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
UNLABELLED The α7-nicotinic cholinergic receptor (α7-nAChR) is a key mediator of brain communication and has been implicated in a wide variety of central nervous system disorders. None of the currently available PET radioligands for α7-nAChR are suitable for quantitative PET imaging, mostly because of insufficient specific binding. The goal of this study was to evaluate the potential of (18)F-ASEM ((18)F-JHU82132) as an α7-nAChR radioligand for PET. METHODS The inhibition binding assay and receptor functional properties of ASEM were assessed in vitro. The brain regional distribution of (18)F-ASEM in baseline and blockade were evaluated in DISC1 mice (dissection) and baboons (PET). RESULTS ASEM is an antagonist for the α7-nAChR with high binding affinity (Ki = 0.3 nM). (18)F-ASEM readily entered the baboon brain and specifically labeled α7-nAChR. The in vivo specific binding of (18)F-ASEM in the brain regions enriched with α7-nAChRs was 80%-90%. SSR180711, an α7-nAChR-selective partial agonist, blocked (18)F-ASEM binding in the baboon brain in a dose-dependent manner, suggesting that the binding of (18)F-ASEM was mediated by α7-nAChRs and the radioligand was suitable for drug evaluation studies. In the baboon baseline studies, the brain regional volume of distribution (VT) values for (18)F-ASEM were 23 (thalamus), 22 (insula), 18 (hippocampus), and 14 (cerebellum), whereas in the binding selectivity (blockade) scan, all regional VT values were reduced to less than 4. The range of regional binding potential values in the baboon brain was from 3.9 to 6.6. In vivo cerebral binding of (18)F-ASEM and α7-nAChR expression in mutant DISC1 mice, a rodent model of schizophrenia, was significantly lower than in control animals, which is in agreement with previous postmortem human data. CONCLUSION (18)F-ASEM holds promise as a radiotracer with suitable imaging properties for quantification of α7-nAChR in the human brain.
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Affiliation(s)
- Andrew G Horti
- Department of Radiology, Johns Hopkins School of Medicine, Baltimore, Maryland
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Gao Y, Kellar KJ, Yasuda RP, Tran T, Xiao Y, Dannals RF, Horti AG. Derivatives of dibenzothiophene for positron emission tomography imaging of α7-nicotinic acetylcholine receptors. J Med Chem 2013; 56:7574-89. [PMID: 24050653 DOI: 10.1021/jm401184f] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
A new series of derivatives of 3-(1,4-diazabicyclo[3.2.2]nonan-4-yl)dibenzo[b,d]thiophene 5,5-dioxide with high binding affinities and selectivity for α7-nicotinic acetylcholine receptors (α7-nAChRs) (Ki = 0.4-20 nM) has been synthesized for positron emission tomography (PET) imaging of α7-nAChRs. Two radiolabeled members of the series [(18)F]7a (Ki = 0.4 nM) and [(18)F]7c (Ki = 1.3 nM) were synthesized. [(18)F]7a and [(18)F]7c readily entered the mouse brain and specifically labeled α7-nAChRs. The α7-nAChR selective ligand 1 (SSR180711) blocked the binding of [(18)F]7a in the mouse brain in a dose-dependent manner. The mouse blocking studies with non-α7-nAChR central nervous system drugs demonstrated that [(18)F]7a is highly α7-nAChR selective. In agreement with its binding affinity the binding potential of [(18)F]7a (BPND = 5.3-8.0) in control mice is superior to previous α7-nAChR PET radioligands. Thus, [(18)F]7a displays excellent imaging properties in mice and has been chosen for further evaluation as a potential PET radioligand for imaging of α7-nAChR in non-human primates.
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Affiliation(s)
- Yongjun Gao
- Russell H. Morgan Department of Radiology and Radiological Sciences, Division of Nuclear Medicine, The Johns Hopkins University School of Medicine , 600 North Wolfe Street, Baltimore, Maryland 21287-0816, United States
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Wong DF, Kuwabara H, Kim J, Brasic JR, Chamroonrat W, Gao Y, Valentine H, Willis W, Mathur A, McCaul ME, Wand G, Gean EG, Dannals RF, Horti AG. PET imaging of high-affinity α4β2 nicotinic acetylcholine receptors in humans with 18F-AZAN, a radioligand with optimal brain kinetics. J Nucl Med 2013; 54:1308-14. [PMID: 23801676 DOI: 10.2967/jnumed.112.108001] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
UNLABELLED We evaluated (-)-2-(6-[(18)F]fluoro-2,3'-bipyridin-5'-yl)-7-methyl-7-aza-bicyclo[2.2.1]heptane ((18)F-AZAN), a novel radiotracer that binds to α4β2 nicotinic acetylcholine receptors (α4β2-nAChRs) and shows high specific binding and rapid and reversible kinetics in the baboon and human brain. METHODS We tested safety tolerability and test-retest reliability (n = 5) and proposed initial quantification of (18)F-AZAN receptors in 3 healthy human subjects who had nicotine exposure and 9 who did not. We also present a receptor blocking study in a nicotine subject dosed with the α4β2-nAChR-selective partial agonist varenicline. RESULTS Radiation dosimetry PET/CT experiments indicated that most human organs received doses between 0.008 and 0.015 mSv/MBq, with an effective dose of approximately 0.014 mSv/MBq. The tracer rapidly entered the brain, and the peak was reached before 20 min, even for thalamus. Ninety-minute scans were sufficient for (18)F-AZAN to obtain the ratio at equilibrium of specifically bound radioligand to nondisplaceable radioligand in tissue (BPND) using plasma reference graphical analysis, which showed excellent reproducibility of BPND (test-retest variability < 10%) in the nAChR-rich brain regions. Regional plasma reference graphical analysis BP(ND) values exceeded 2 in the midbrain tegmental nuclei, lateral geniculate body, and thalamus for nonsmokers (n = 9) but were less than 1 in the nAChR-poor brain regions. There was a dramatic reduction of (18)F-AZAN brain uptake in smokers and varenicline-treated subjects. CONCLUSION (18)F-AZAN is a highly specific, safe, and effective PET radioligand for human subjects that requires only 90 min of PET scanning to estimate high-affinity α4β2-nAChR in the living human brain.
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Affiliation(s)
- Dean F Wong
- Department of Radiology, School of Medicine, Johns Hopkins University, Baltimore, Maryland, USA.
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Horti AG, Kuwabara H, Holt DP, Dannals RF, Wong DF. Recent PET radioligands with optimal brain kinetics for imaging nicotinic acetylcholine receptors. J Labelled Comp Radiopharm 2013; 56:159-66. [DOI: 10.1002/jlcr.3020] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2012] [Revised: 11/27/2012] [Accepted: 12/07/2012] [Indexed: 01/28/2023]
Affiliation(s)
- Andrew G. Horti
- Division of Nuclear Medicine, Department of Radiology; Johns Hopkins University; Baltimore; MD; USA
| | - Hiroto Kuwabara
- Division of Nuclear Medicine, Department of Radiology; Johns Hopkins University; Baltimore; MD; USA
| | - Daniel P. Holt
- Division of Nuclear Medicine, Department of Radiology; Johns Hopkins University; Baltimore; MD; USA
| | - Robert F. Dannals
- Division of Nuclear Medicine, Department of Radiology; Johns Hopkins University; Baltimore; MD; USA
| | - Dean F. Wong
- Division of Nuclear Medicine, Department of Radiology; Johns Hopkins University; Baltimore; MD; USA
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Horti AG, Ravert HT, Gao Y, Holt DP, Bunnelle WH, Schrimpf MR, Li T, Ji J, Valentine H, Scheffel U, Kuwabara H, Wong DF, Dannals RF. Synthesis and evaluation of new radioligands [(11)C]A-833834 and [(11)C]A-752274 for positron-emission tomography of α7-nicotinic acetylcholine receptors. Nucl Med Biol 2013; 40:395-402. [PMID: 23294899 DOI: 10.1016/j.nucmedbio.2012.11.013] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2012] [Revised: 10/31/2012] [Accepted: 11/20/2012] [Indexed: 01/31/2023]
Abstract
INTRODUCTION α7-nicotinic acetylcholine receptor (α7-nAChR) is one of the major neuronal nAChR subtypes. α7-nAChR is involved in variety of neuronal processes and disorders including schizophrenia and Alzheimer's disease. A number of α7-nAChR PET radioligands have been developed, but a quality radiotracer remains to be discovered. METHODS High binding affinity α7-nAChR ligands A-833834 and A-752274 were radiolabeled with (11)C. Baseline and blockade biodistribution studies in the mouse brain of [(11)C]A-833834 (5-(6-(5-[(11)C]methylhexahydropyrrolo[3,4-c]pyrrol-2(1H)-yl)pyridazin-3-yl)-1H-indole) and [(11)C]A-752274 (2-(6-[(11)C]methyl-3,6-diazabicyclo[3.2.0]heptan-3-yl)-7-(6-methyl-3,6-diazabicyclo[3.2.0]heptan-3-yl)-9H-fluoren-9-one) were performed. [(11)C]A-752274 was evaluated in a baseline baboon PET study. RESULTS [(11)C]A-833834 and [(11)C]A-752274 were synthesized by radiomethylation of corresponding des-methyl precursors. The radioligands were prepared with radiochemical yield of 12%-32%, high specific radioactivity (330-403GBq/μmol) and radiochemical purity>95%. Dissection studies with [(11)C]A-833834 demonstrated low specific α7-nAChR binding in the mouse brain. [(11)C]A-752274 specifically (~50%) labeled α7-nAChR in the mouse thalamus. However, [(11)CA-752274 exhibited low brain uptake in baboon (%SUV<100). CONCLUSION Two novel α7-nAChR ligands radioligands were synthesized and studied in animals. Specific binding of [(11)C]A-833834 in the mouse brain is low due to the insufficient binding affinity of the radioligand. The very high binding affinity [(11)C]A-752274 exhibited good specific binding in the α7-nAChR-rich mouse brain regions. The low uptake of [(11)C]A-752274 in the baboon brain is due to its high hydrophilicity, rapid metabolism or other properties. Future development of α7-nAChR PET radioligands will be based on compounds with high binding affinities and good blood-brain barrier permeability.
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Affiliation(s)
- Andrew G Horti
- Division of Nuclear Medicine, Department of Radiology, Johns Hopkins School of Medicine, Baltimore, MD 21205, USA.
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Brašić JR, Cascella N, Kumar A, Zhou Y, Hilton J, Raymont V, Crabb A, Guevara MR, Horti AG, Wong DF. Positron emission tomography experience with 2-[¹⁸F]fluoro-3-(2(S)-azetidinylmethoxy)pyridine (2-[¹⁸F]FA) in the living human brain of smokers with paranoid schizophrenia. Synapse 2012; 66:352-68. [PMID: 22169936 PMCID: PMC3445266 DOI: 10.1002/syn.21520] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2011] [Accepted: 11/18/2011] [Indexed: 11/10/2022]
Abstract
Utilizing postmortem data (Breese et al. [2000] Neuropsychopharmacology 23:351-364), we hypothesized that the densities of high-affinity neuronal α4β2 nicotinic acetylcholine receptors (nAChRs) in the brain exist in a continuum from highest to lowest as follows: smokers without schizophrenia > smokers with schizophrenia > nonsmokers without schizophrenia > nonsmokers with schizophrenia. Application of the Kruskal-Wallis Test (Statacorp, 2003) to the postmortem data (Breese et al. [2000] Neuropsychopharmacology 23:351-364) confirmed the hypothesized order in the cortex and the hippocampus and attained significance in the caudate and the thalamus. Positron emission tomography (PET) was performed for 60 min at 6 h after the intravenous administration of 444 megabequerels [MBq] (12 mCi) 2-[¹⁸F]fluoro-3-(2(S)-azetidinylmethoxy)pyridine (2-[¹⁸F]FA), a radiotracer for high-affinity neuronal α4β2 nAChRs, as a bolus plus continuous infusion to 10 adults (seven men and three women) (six smokers including five with paranoid schizophrenia and four nonsmokers) ranging in age from 22 to 56 years (mean 40.1, standard deviation 13.6). The thalamic nondisplaceable binding potential (BP(ND) ) was 1.32 ± 0.19 (mean ± standard deviation) for healthy control nonsmokers; 0.50 ± 0.19 for smokers with paranoid schizophrenia; and 0.51 for the single smoker without paranoid schizophrenia. The thalamic BP(ND) s of nonsmokers were significantly higher than those of smokers who smoked cigarettes a few hours before the scans (P = 0.0105) (StataCorp, 2003), which was likely due to occupancy of nAChRs by inhaled nicotine in smokers. Further research is needed to rule out the effects of confounding variables.
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Affiliation(s)
- James Robert Brašić
- Division of Nuclear Medicine, The Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Johns Hopkins Outpatient Center, Baltimore, Maryland 21287-0807, USA.
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Kuwabara H, Wong DF, Gao Y, Valentine H, Holt DP, Ravert HT, Dannals RF, Horti AG. PET Imaging of Nicotinic Acetylcholine Receptors in Baboons with 18F-AZAN, a Radioligand with Improved Brain Kinetics. J Nucl Med 2011; 53:121-9. [DOI: 10.2967/jnumed.111.092338] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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Potter R, Horti AG, Ravert HT, Holt DP, Finley P, Scheffel U, Dannals RF, Wahl RL. Synthesis and in vivo evaluation of (S)-6-(4-fluorophenoxy)-3-((1-[11C]methylpiperidin-3-yl)methyl)-2-o-tolylquinazolin-4(3H)-one, a potential PET tracer for growth hormone secretagogue receptor (GHSR). Bioorg Med Chem 2011; 19:2368-72. [PMID: 21388815 DOI: 10.1016/j.bmc.2011.02.021] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2010] [Revised: 02/04/2011] [Accepted: 02/11/2011] [Indexed: 10/18/2022]
Abstract
The peptide hormone ghrelin mediates through action on its receptor, the growth hormone secretagogue receptor (GHSR), and is known to play an important role in a variety of metabolic functions including appetite stimulation, weight gain, and suppression of insulin secretion. In light of the fact that obesity is one of the major health problems plaguing the modern society, the ghrelin signaling system continues to remain an important and attractive pharmacological target for the treatment of obesity. In vivo imaging of the GHSR could shed light on the mechanism by which ghrelin affects feeding behavior and thus offers a new therapeutic perspective for the development of effective treatments. Recently, a series of piperidine-substituted quinazolinone derivatives was reported to be selective and potent GHSR antagonists with high binding affinities. Described herein is the synthesis, in vitro, and in vivo evaluation of (S)-6-(4-fluorophenoxy)-3-((1-[(11)C]methylpiperidin-3-yl)methyl)-2-o-tolylquinazolin-4(3H)-one ([(11)C]1), a potential PET radioligand for imaging GHSR.
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Affiliation(s)
- Rachel Potter
- Division of Nuclear Medicine, Department of Radiology, The Johns Hopkins University School of Medicine, 600 North Wolfe Street, Baltimore, MD 21287-0816, USA
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Abstract
Improved syntheses of 7-methyl-2-exo-[3'-(2-bromopyridin-3-yl)-5'-pyridinyl]-7-azabicyclo[2.2.1]heptanes (3) and 7-methyl-2-exo-[3'-(6-bromopyridin-2-yl)-5'-pyridinyl]-7-azabicyclo[2.2.1]heptanes (4), precursors for PET radioligands [(18)F]XTRA (1) and [(18)F]AZAN (2), involving a key Stille coupling step followed by deprotection of Boc group and N-methylation are described. The new synthetic procedures provided the title compounds in more than 40% overall yields.
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Affiliation(s)
- Yongjun Gao
- Russell H. Morgan Department of Radiology and Radiological Sciences, School of Medicine, Johns Hopkins University, 600 North Wolfe Street, Baltimore, Maryland 21287-0816
| | - Haofan Wang
- Russell H. Morgan Department of Radiology and Radiological Sciences, School of Medicine, Johns Hopkins University, 600 North Wolfe Street, Baltimore, Maryland 21287-0816
| | - Ronnie C. Mease
- Russell H. Morgan Department of Radiology and Radiological Sciences, School of Medicine, Johns Hopkins University, 600 North Wolfe Street, Baltimore, Maryland 21287-0816
| | - Martin G. Pomper
- Russell H. Morgan Department of Radiology and Radiological Sciences, School of Medicine, Johns Hopkins University, 600 North Wolfe Street, Baltimore, Maryland 21287-0816
| | - Andrew G. Horti
- Russell H. Morgan Department of Radiology and Radiological Sciences, School of Medicine, Johns Hopkins University, 600 North Wolfe Street, Baltimore, Maryland 21287-0816
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Horti AG, Dannals RF. Recent advances in the medicinal radiochemistry of radioligands for cerebral in vivo imaging. Curr Top Med Chem 2010; 10:1476. [PMID: 20868362 DOI: 10.2174/156802610793176800] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2009] [Accepted: 04/15/2010] [Indexed: 11/22/2022]
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Horti AG, Dannals RF. Current topics in the development of radioligands for positron-emission tomography imaging. Curr Top Med Chem 2010; 10:1584. [PMID: 20868363 DOI: 10.2174/156802610793176765] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2009] [Accepted: 04/15/2010] [Indexed: 11/22/2022]
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Horti AG, Gao Y, Ravert HT, Finley P, Valentine H, Wong DF, Endres CJ, Savonenko AV, Dannals RF. Synthesis and biodistribution of [11C]A-836339, a new potential radioligand for PET imaging of cannabinoid type 2 receptors (CB2). Bioorg Med Chem 2010; 18:5202-7. [PMID: 20554448 PMCID: PMC2903661 DOI: 10.1016/j.bmc.2010.05.058] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2010] [Revised: 05/17/2010] [Accepted: 05/20/2010] [Indexed: 12/22/2022]
Abstract
Recently, A-836339 [2,2,3,3-tetramethylcyclopropanecarboxylic acid [3-(2-methoxyethyl)-4,5-dimethyl-3H-thiazol-(2Z)-ylidene]amide] (1) was reported to be a selective CB2 agonist with high binding affinity. Here we describe the radiosynthesis of [11C]A-836339 ([11C]1) via its desmethyl precursor as a candidate radioligand for imaging CB2 receptors with positron-emission tomography (PET). Whole body and the regional brain distribution of [11C]1 in control CD1 mice demonstrated that this radioligand exhibits specific uptake in the CB2-rich spleen and little specific in vivo binding in the control mouse brain. However, [11C]1 shows specific cerebral uptake in the lipopolysaccharide (LPS)-induced mouse model of neuroinflammation and in the brain areas with Abeta amyloid plaque deposition in a mouse model of Alzheimer's disease (APPswe/PS1dE9 mice). These data establish a proof of principle that CB2 receptors binding in the neuroinflammation and related disorders can be measured in vivo.
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Affiliation(s)
- Andrew G Horti
- Division of Nuclear Medicine, Department of Radiology, Johns Hopkins Medical Institutions, 600 North Wolfe Street, Baltimore, MD 21287-0816, USA.
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Gao Y, Ravert HT, Kuwabara H, Xiao Y, Endres CJ, Hilton J, Holt DP, Kumar A, Alexander M, Wong DF, Dannals RF, Horti AG. Synthesis and biological evaluation of novel carbon-11 labeled pyridyl ethers: candidate ligands for in vivo imaging of alpha4beta2 nicotinic acetylcholine receptors (alpha4beta2-nAChRs) in the brain with positron emission tomography. Bioorg Med Chem 2009; 17:4367-77. [PMID: 19481945 DOI: 10.1016/j.bmc.2009.05.021] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2009] [Revised: 05/05/2009] [Accepted: 05/09/2009] [Indexed: 10/20/2022]
Abstract
The most abundant subtype of cerebral nicotinic acetylcholine receptors (nAChR), alpha4beta2, plays a critical role in various brain functions and pathological states. Imaging agents suitable for visualization and quantification of alpha4beta2 nAChRs by positron emission tomography (PET) would present unique opportunities to define the function and pharmacology of the nAChRs in the living human brain. In this study, we report the synthesis, nAChR binding affinity, and pharmacological properties of several novel 3-pyridyl ether compounds. Most of these derivatives displayed a high affinity to the nAChR and a high subtype selectivity for alpha4beta2-nAChR. Three of these novel nAChR ligands were radiolabeled with the positron-emitting isotope (11)C and evaluated in animal studies as potential PET radiotracers for imaging of cerebral nAChRs with improved brain kinetics.
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Affiliation(s)
- Yongjun Gao
- Department of Radiology, Division of Nuclear Medicine, PET Center, The Johns Hopkins University School of Medicine, Baltimore, MD 21287-0816, USA
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Mukhin AG, Kimes AS, Chefer SI, Matochik JA, Contoreggi CS, Horti AG, Vaupel DB, Pavlova O, Stein EA. Greater nicotinic acetylcholine receptor density in smokers than in nonsmokers: a PET study with 2-18F-FA-85380. J Nucl Med 2008; 49:1628-35. [PMID: 18794265 DOI: 10.2967/jnumed.108.050716] [Citation(s) in RCA: 105] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
UNLABELLED Assays of human postmortem brain tissue have revealed that smokers have greater densities of high-affinity nicotinic acetylcholine receptors (nAChRs) in several brain regions than do nonsmokers or exsmokers. Quantitative PET imaging of nAChRs in humans has recently been reported using the alpha4beta2* subtype-specific radioligand 2-(18)F-FA-85380 (2FA). METHODS We used PET and 2FA to measure total volumes of distribution corrected for the free fraction of 2FA in plasma (V(T)/f(P)) in 10 nonsmokers and 6 heavy smokers (>14 cigarettes/d; abstinent for >36 h). Dynamic PET scans were performed over 8 h, commencing immediately after a bolus injection of 2FA. Anatomic sampling was performed on PET images that were coregistered to MR images acquired from each volunteer. Data were analyzed by Logan plots and by 1- and 2-tissue-compartment models using unbound, unmetabolized arterial 2FA concentration as the input function. RESULTS All modeling methods yielded similar results. V(T)/f(P) was significantly higher in smokers than in nonsmokers in all brain regions tested, except the thalamus. We used measures of V(T)/f(P) and estimates of nondisplaceable volume of distribution and found 25%-200% higher values in smokers than in nonsmokers for the volume of distribution for the specific binding compartment in the frontal cortex, midbrain, putamen, pons, cerebellum, and corpus callosum. These findings were consistent with voxel-based analysis using statistical parametric mapping. CONCLUSION Our findings suggest that PET with 2FA can be used to study the role of nicotine-induced upregulation of nAChRs in active smokers and during smoking cessation.
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Affiliation(s)
- Alexey G Mukhin
- National Institute on Drug Abuse Intramural Research Program, National Institutes of Health, Department of Health and Human Services, Baltimore, Maryland, USA
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Gao Y, Kuwabara H, Spivak CE, Xiao Y, Kellar K, Ravert HT, Kumar A, Alexander M, Hilton J, Wong DF, Dannals RF, Horti AG. Discovery of (−)-7-Methyl-2-exo-[3′-(6-[18F]fluoropyridin-2-yl)-5′-pyridinyl]-7-azabicyclo[2.2.1]heptane, a Radiolabeled Antagonist for Cerebral Nicotinic Acetylcholine Receptor (α4β2-nAChR) with Optimal Positron Emission Tomography Imaging Properties. J Med Chem 2008; 51:4751-64. [DOI: 10.1021/jm800323d] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Yongjun Gao
- Department of Radiology, Division of Nuclear Medicine, The Johns Hopkins University School of Medicine, 600 North Wolfe Street, Baltimore, Maryland 21287-0816, Cellular Neurophysiology Section, Cellular Neurobiology Branch, IRP, National Institute on Drug Abuse, 333 Cassell Drive, Baltimore, Maryland 21224, and Georgetown University, 3900 Reservoir Road, Washington, D.C. 20007
| | - Hiroto Kuwabara
- Department of Radiology, Division of Nuclear Medicine, The Johns Hopkins University School of Medicine, 600 North Wolfe Street, Baltimore, Maryland 21287-0816, Cellular Neurophysiology Section, Cellular Neurobiology Branch, IRP, National Institute on Drug Abuse, 333 Cassell Drive, Baltimore, Maryland 21224, and Georgetown University, 3900 Reservoir Road, Washington, D.C. 20007
| | - Charles E. Spivak
- Department of Radiology, Division of Nuclear Medicine, The Johns Hopkins University School of Medicine, 600 North Wolfe Street, Baltimore, Maryland 21287-0816, Cellular Neurophysiology Section, Cellular Neurobiology Branch, IRP, National Institute on Drug Abuse, 333 Cassell Drive, Baltimore, Maryland 21224, and Georgetown University, 3900 Reservoir Road, Washington, D.C. 20007
| | - Yingxian Xiao
- Department of Radiology, Division of Nuclear Medicine, The Johns Hopkins University School of Medicine, 600 North Wolfe Street, Baltimore, Maryland 21287-0816, Cellular Neurophysiology Section, Cellular Neurobiology Branch, IRP, National Institute on Drug Abuse, 333 Cassell Drive, Baltimore, Maryland 21224, and Georgetown University, 3900 Reservoir Road, Washington, D.C. 20007
| | - Kenneth Kellar
- Department of Radiology, Division of Nuclear Medicine, The Johns Hopkins University School of Medicine, 600 North Wolfe Street, Baltimore, Maryland 21287-0816, Cellular Neurophysiology Section, Cellular Neurobiology Branch, IRP, National Institute on Drug Abuse, 333 Cassell Drive, Baltimore, Maryland 21224, and Georgetown University, 3900 Reservoir Road, Washington, D.C. 20007
| | - Hayden T. Ravert
- Department of Radiology, Division of Nuclear Medicine, The Johns Hopkins University School of Medicine, 600 North Wolfe Street, Baltimore, Maryland 21287-0816, Cellular Neurophysiology Section, Cellular Neurobiology Branch, IRP, National Institute on Drug Abuse, 333 Cassell Drive, Baltimore, Maryland 21224, and Georgetown University, 3900 Reservoir Road, Washington, D.C. 20007
| | - Anil Kumar
- Department of Radiology, Division of Nuclear Medicine, The Johns Hopkins University School of Medicine, 600 North Wolfe Street, Baltimore, Maryland 21287-0816, Cellular Neurophysiology Section, Cellular Neurobiology Branch, IRP, National Institute on Drug Abuse, 333 Cassell Drive, Baltimore, Maryland 21224, and Georgetown University, 3900 Reservoir Road, Washington, D.C. 20007
| | - Mohab Alexander
- Department of Radiology, Division of Nuclear Medicine, The Johns Hopkins University School of Medicine, 600 North Wolfe Street, Baltimore, Maryland 21287-0816, Cellular Neurophysiology Section, Cellular Neurobiology Branch, IRP, National Institute on Drug Abuse, 333 Cassell Drive, Baltimore, Maryland 21224, and Georgetown University, 3900 Reservoir Road, Washington, D.C. 20007
| | - John Hilton
- Department of Radiology, Division of Nuclear Medicine, The Johns Hopkins University School of Medicine, 600 North Wolfe Street, Baltimore, Maryland 21287-0816, Cellular Neurophysiology Section, Cellular Neurobiology Branch, IRP, National Institute on Drug Abuse, 333 Cassell Drive, Baltimore, Maryland 21224, and Georgetown University, 3900 Reservoir Road, Washington, D.C. 20007
| | - Dean F. Wong
- Department of Radiology, Division of Nuclear Medicine, The Johns Hopkins University School of Medicine, 600 North Wolfe Street, Baltimore, Maryland 21287-0816, Cellular Neurophysiology Section, Cellular Neurobiology Branch, IRP, National Institute on Drug Abuse, 333 Cassell Drive, Baltimore, Maryland 21224, and Georgetown University, 3900 Reservoir Road, Washington, D.C. 20007
| | - Robert F. Dannals
- Department of Radiology, Division of Nuclear Medicine, The Johns Hopkins University School of Medicine, 600 North Wolfe Street, Baltimore, Maryland 21287-0816, Cellular Neurophysiology Section, Cellular Neurobiology Branch, IRP, National Institute on Drug Abuse, 333 Cassell Drive, Baltimore, Maryland 21224, and Georgetown University, 3900 Reservoir Road, Washington, D.C. 20007
| | - Andrew G. Horti
- Department of Radiology, Division of Nuclear Medicine, The Johns Hopkins University School of Medicine, 600 North Wolfe Street, Baltimore, Maryland 21287-0816, Cellular Neurophysiology Section, Cellular Neurobiology Branch, IRP, National Institute on Drug Abuse, 333 Cassell Drive, Baltimore, Maryland 21224, and Georgetown University, 3900 Reservoir Road, Washington, D.C. 20007
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46
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Fan H, Kotsikorou E, Hoffman AF, Ravert HT, Holt D, Hurst DP, Lupica CR, Reggio PH, Dannals RF, Horti AG. Analogs of JHU75528, a PET ligand for imaging of cerebral cannabinoid receptors (CB1): development of ligands with optimized lipophilicity and binding affinity. Eur J Med Chem 2008; 44:593-608. [PMID: 18511157 DOI: 10.1016/j.ejmech.2008.03.040] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2007] [Revised: 03/21/2008] [Accepted: 03/27/2008] [Indexed: 11/16/2022]
Abstract
Cyano analogs of Rimonabant with high binding affinity for the cerebral cannabinoid receptor (CB1) and with optimized lipophilicity have been synthesized as potential positron emission tomography (PET) ligands. The best ligands of the series are optimal targets for the future radiolabeling with PET isotopes and in vivo evaluation as radioligands with enhanced properties for PET imaging of CB1 receptors in human subjects. Extracellular electrophysiological recordings in rodent brain slices demonstrated that JHU75528, 4, the lead compound of the new series, has functional CB antagonist properties that are consistent with its structural relationship to Rimonabant. Molecular modeling analysis revealed an important role of the binding of the cyano group with the CB1 binding pocket.
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Affiliation(s)
- Hong Fan
- PET Center, Division of Nuclear Medicine, Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
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47
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Chefer SI, Kimes AS, Matochik JA, Horti AG, Kurian V, Shumway D, Domino EF, London ED, Mukhin AG. Estimation of D2-like receptor occupancy by dopamine in the putamen of hemiparkinsonian Monkeys. Neuropsychopharmacology 2008; 33:270-8. [PMID: 17429408 DOI: 10.1038/sj.npp.1301404] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
To advance understanding of the neurochemical changes in Parkinson's disease (PD), we compared D2-like dopamine receptor occupancy by dopamine in the control and lesioned putamen of four pig-tailed macaques treated unilaterally with MPTP. PET and in vitro binding techniques were used to measure binding potential (BP(*)) and density of D2-like dopamine receptors (B(max)), respectively. As would be expected in PD, relatively higher values of BP(*) and B(max) and less amphetamine-induced decrease in [(11)C]raclopride binding were observed in the lesioned compared with the contralateral putamen in each animal. The percent differences between lesioned and contralateral sides were similar whether the measurements were of [(11)C]raclopride BP(*) or B(max) values, measured in vivo and in vitro, respectively. As [(11)C]raclopride BP(*) is a measure of the density of D2-like dopamine receptors available for radioligand binding (i.e., not occupied by dopamine), these findings suggest that the fractional occupancy of receptors by endogenous dopamine in the lesioned putamen is nearly equal to that in the contralateral putamen. Therefore, the absolute number of receptors occupied by dopamine, which is a product of receptor density and fractional occupancy by dopamine, is greater in the lesioned than in the contralateral putamen. One possible explanation for the lack of differences in fractional occupancy of D2 receptors by dopamine (despite a loss in available dopamine) is a lesion-induced increase in a portion of low-affinity D2 receptors to a state of high affinity for dopamine.
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Affiliation(s)
- Svetlana I Chefer
- Neuroimaging Research Branch, Intramural Research Program, National Institute on Drug Abuse, NIH/DHHS, Baltimore, MD, USA
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48
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Chefer SI, Pavlova OA, Zhang Y, Vaupel DB, Kimes AS, Horti AG, Stein E, Mukhin AG. NIDA522131, a new radioligand for imaging extrathalamic nicotinic acetylcholine receptors: in vitro and in vivo evaluation. J Neurochem 2007; 104:306-15. [PMID: 17986233 DOI: 10.1111/j.1471-4159.2007.05009.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A novel radioligand, 6-chloro-3-((2-(S)-azetidinyl)methoxy)-5-(2-fluoropyridin-4-yl)pyridine (NIDA522131), for imaging extrathalamic nicotinic acetylcholine receptors (nAChRs) was characterized in vitro and in vivo using positron emission tomography. The K(d) and T(1/2) of dissociation of NIDA522131 binding measured at 37 degrees C in vitro were 4.9 +/- 0.4 pmol/L and 81 +/- 5 min, respectively. The patterns of radioactivity distribution in monkey brain in vivo was similar to that of 2-[(18)F]fluoro-3-(2(S)-azetidinylmethoxy)pyridine (2FA), a radioligand that has been successfully used in humans, and matched the alpha(4)beta(2)* nAChRs distribution. Comparison between [(18)F]NIDA522131 and 2FA demonstrated better in vivo binding properties of the new radioligand and substantially greater radioactivity accumulation in brain. Consistent with [(18)F]NIDA522131 elevated affinity for nAChRs and its increased lipophilicity, both, the total and non-displaceable distribution volumes were substantially higher than those of 2FA. Estimated binding potential values in different brain regions, characterizing the specificity of receptor binding, were 3-4 fold higher for [(18)F]NIDA522131 than those of 2FA. Pharmacological evaluation in mice demonstrated a toxicity that was comparable to 2FA and is in agreement with a 2300 fold higher affinity at alpha(4)beta(2)* versus alpha(3)beta(4)* nAChRs. These results suggest that [(18)F]NIDA522131 is a promising positron emission tomography radioligand for studying extrathalamic nAChR in humans.
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Affiliation(s)
- Svetlana I Chefer
- Neuroimaging Research Branch, Intramural Research Program, National Institute on Drug Abuse, National Institute of Health, Department of Health and Human Services, Baltimore, Maryland, USA
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49
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Gao Y, Horti AG, Kuwabara H, Ravert HT, Hilton J, Holt DP, Kumar A, Alexander M, Endres CJ, Wong DF, Dannals RF. Derivatives of (−)-7-Methyl-2-(5-(pyridinyl)pyridin-3-yl)-7-azabicyclo[2.2.1]heptane Are Potential Ligands for Positron Emission Tomography Imaging of Extrathalamic Nicotinic Acetylcholine Receptors. J Med Chem 2007; 50:3814-24. [PMID: 17629263 DOI: 10.1021/jm070224t] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A series of novel racemic 7-methyl-2-(5-(pyridinyl)pyridin-3-yl)-7-azabicyclo[2.2.1]heptane derivatives with picomolar in vitro binding affinity at nicotinic acetylcholine receptors (nAChRs) were synthesized and their enantiomers were resolved by semipreparative chiral HPLC. The (-)-enantiomers showed substantially greater in vitro inhibition binding affinity than the corresponding (+)-enantiomers. The compounds with best binding affinities have been radiolabeled with positron emitting isotopes 11C and 18F as potential radioligands for positron emission tomography imaging of the nAChR. In vivo enantioselectivity of the radiolabeled (-)-7-methyl-2-(5-(pyridinyl)pyridin-3-yl)-7-azabicyclo[2.2.1]heptane derivatives was observed in biodistribution studies in rodents and baboon. One of the radiolabeled compounds, (-)-7-methyl-2-exo-[3'-(2-[18F]fluoropyridin-5-yl))-5'-pyridinyl]-7-azabicyclo[2.2.1]heptane, exhibited good properties as a first practical PET radioligand for imaging of extrathalamic nAChR in baboon brain and holds promise for further investigation for human studies.
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Affiliation(s)
- Yongjun Gao
- Division of Nuclear Medicine, Department of Radiology, The Johns Hopkins University School of Medicine, 600 North Wolfe Street, Baltimore, MD 21287-0816, USA
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50
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Gao Y, Ravert HT, Holt D, Dannals RF, Horti AG. 6-Chloro-3-(((1-[11C]methyl)-2-(S)-pyrrolidinyl)methoxy)-5-(2-fluoropyridin-4-yl)pyridine ([11C]JHU85270), a potent ligand for nicotinic acetylcholine receptor imaging by positron emission tomography. Appl Radiat Isot 2007; 65:947-51. [PMID: 17566748 DOI: 10.1016/j.apradiso.2007.04.013] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2006] [Revised: 03/16/2007] [Accepted: 04/25/2007] [Indexed: 11/17/2022]
Abstract
6-Chloro-3-((1-methyl)-2-(S)-pyrrolidinyl)methoxy)-5-(2-fluoropyridin-4-yl)pyridine (JHU85270), a novel high-affinity ligand for the alpha4beta2 nicotine acetylcholine receptor (nAChR) (K(i)=86, 115 pM; K(i)(JHU85270)/K(i)(epibatidine)=1.7) with a log D(7.4)=1.6 was synthesized in 56% overall yield. [(11)C]JHU85270 was synthesized from [(11)C]-methyl iodide and the corresponding normethyl precursor. The average time of radiosynthesis, purification, and formulation was 37 min from the end of bombardment. The average radiochemical yield of [(11)C]JHU85270 was 37%+/-3% (non-decay corrected). The average specific radioactivity was 398+/-165 GBq/micromol (10750+/-4468 mCi/micromol) and the radiochemical purity was greater than 99%.
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Affiliation(s)
- Yongjun Gao
- Division of Nuclear Medicine, Department of Radiology, The Johns Hopkins University, School of Medicine, 600 North Wolfe Street, Baltimore, MD 21287-0816, USA
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