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Zhao Q, Liow JS, Jee JE, Montero Santamaria J, Pamie-George M, Morse C, Wu S, Zoghbi SS, Kim SW, Innis RB, Pike VW, Telu S. [ 11C]ZTP-1: An Effective Short-Lived Radioligand for PET of Rat and Monkey Brain Phosphodiesterase Type 4 Subtype B. J Nucl Med 2025:jnumed.124.269159. [PMID: 40341096 DOI: 10.2967/jnumed.124.269159] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2024] [Accepted: 03/31/2025] [Indexed: 05/10/2025] Open
Abstract
Phosphodiesterase type 4 subtype B (PDE4B) selectively hydrolyzes cyclic adenosine monophosphate to enact numerous downstream signaling events. PDE4B is widely expressed in the brain and is implicated in several neuropsychiatric disorders. Moreover, PDE4B inhibition shows antiinflammatory and antidepressant-like effects in animal studies. [18F]PF-06445974 has been developed to image human brain PDE4B using PET, thereby providing a tool for pathophysiologic studies and drug development. However, a radioligand labeled with shorter-lived 11C would be an alternative for studies that require more than 1 administration into the same imaging subject on a single day. Methods: 8-Cyclopropyl-10-(3,5-difluoro-4-(methoxy)phenyl)-7,8-dihydropyrido[2',3':4,5]pyrrolo[1,2-a]pyrazin-9(6H)-1 (ZTP-1) was identified as possessing many favorable properties for development as a 11C-labeled PET radioligand, including high PDE4B inhibitory potency, moderate computed lipophilicity, and a methoxy group as a potential labeling site. Here, [11C]ZTP-1 was readily obtained by 11C methylation of a synthesized O-desmethyl precursor. PET imaging of rat and rhesus monkey brains was performed with [11C]ZTP-1 at baseline and after administration of PDE4B- and PDE4D-selective inhibitors. Radiometabolite profiles for [11C]ZTP-1 were also determined ex vivo in rat plasma and brains. Results: [11C]ZTP-1 was obtained in a high activity yield and with high molar activity. Rat and monkey PET imaging showed high whole-brain radioactivity uptake with subsequent gradual washout. Challenge experiments verified a high and PDE4B-selective PET signal in rat and monkey brains. Ex vivo rat brain uptake of [11C]ZTP-1 showed less than 1% radiometabolite contamination at 30 min. Total distribution volume measures in monkey brains quickly reached stability. Conclusion: [11C]ZTP-1 is a promising, shorter-lived alternative to [18F]PF-06445974 for quantifying brain PDE4B in rodents and nonhuman primates with PET and warrants further investigation in humans.
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Affiliation(s)
- Qunchao Zhao
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland
| | - Jeih-San Liow
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland
| | - Joo Eun Jee
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland
| | - Jose Montero Santamaria
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland
| | - Matilah Pamie-George
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland
| | - Cheryl Morse
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland
| | - Shawn Wu
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland
| | - Sami S Zoghbi
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland
| | - Sung Won Kim
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland
| | - Robert B Innis
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland
| | - Victor W Pike
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland
| | - Sanjay Telu
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland
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Nerella SG, Eldridge MAG, Innis RB, Pike VW. PET Reporter Probes for Brain Imaging of Transduced Gene and Cell Expression: Status and Challenges. J Med Chem 2025; 68:2198-2218. [PMID: 39879224 DOI: 10.1021/acs.jmedchem.4c02326] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2025]
Abstract
Gene therapy and cell transduction are gaining interest as therapeutic strategies for neurological and psychiatric disorders. Positron emission tomography (PET) has been established as a uniquely powerful modality for brain molecular imaging in vivo. The utility of PET depends on the development and application of suitably specific radiotracers and/or reporter probes. PET probes are potentially useful to confirm the success of gene therapy or cell transduction without the need for brain biopsy or necroscopy. Probes are needed to target proteins expressed by specific exogenous transgenes or cells and could play a crucial role in elucidating neurobiological mechanisms and in longitudinal tracking of expression for therapeutic applications. This perspective article describes the current status and ongoing challenges for the design and development of PET reporter probes for verifying the expression of reporter genes and cells in the brain. Radiochemical aspects, applications, and translational challenges for diagnostic and therapeutic interventions are highlighted.
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Affiliation(s)
- Sridhar Goud Nerella
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland, 20892 United States
| | - Mark A G Eldridge
- Laboratory of Neuropsychology, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland, 20892 United States
- Biosciences Institute, Newcastle University, Newcastle-upon-Tyne, NE1 7RU, U.K
| | - Robert B Innis
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland, 20892 United States
| | - Victor W Pike
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland, 20892 United States
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Li B, Wadhwa P, Lerchner W, Zanotti-Fregonara P, Liow JS, Yan X, Zoghbi SS, Nerella SG, Telu S, Morse CL, Solis O, Gomez JL, Holt DP, Dannals RF, Cummins AC, Innis RB, Pike VW, Richmond BJ, Michaelides M, Eldridge MAG. Evaluation of [ 18F]fluoroestradiol and ChRERα as a gene expression PET reporter system in rhesus monkey brain. Mol Ther 2024; 32:2223-2231. [PMID: 38796702 PMCID: PMC11286805 DOI: 10.1016/j.ymthe.2024.05.031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2023] [Revised: 04/15/2024] [Accepted: 05/23/2024] [Indexed: 05/28/2024] Open
Abstract
Positron emission tomography (PET) reporter systems are a valuable means of estimating the level of expression of a transgene in vivo. For example, the safety and efficacy of gene therapy approaches for the treatment of neurological and neuropsychiatric disorders could be enhanced via the monitoring of exogenous gene expression levels in the brain. The present study evaluated the ability of a newly developed PET reporter system [18F]fluoroestradiol ([18F]FES) and the estrogen receptor-based PET reporter ChRERα, to monitor expression levels of a small hairpin RNA (shRNA) designed to suppress choline acetyltransferase (ChAT) expression in rhesus monkey brain. The ChRERα gene and shRNA were expressed from the same transcript via lentivirus injected into monkey striatum. In two monkeys that received injections of viral vector, [18F]FES binding increased by 70% and 86% at the target sites compared with pre-injection, demonstrating that ChRERα expression could be visualized in vivo with PET imaging. Post-mortem immunohistochemistry confirmed that ChAT expression was significantly suppressed in regions in which [18F]FES uptake was increased. The consistency between PET imaging and immunohistochemical results suggests that [18F]FES and ChRERα can serve as a PET reporter system in rhesus monkey brain for in vivo evaluation of the expression of potential therapeutic agents, such as shRNAs.
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Affiliation(s)
- Bing Li
- Laboratory of Neuropsychology, National Institute of Mental Health, National Institutes of Health, Bethesda, MD 20814, USA
| | - Palak Wadhwa
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, MD 20814, USA
| | - Walter Lerchner
- Laboratory of Neuropsychology, National Institute of Mental Health, National Institutes of Health, Bethesda, MD 20814, USA
| | - Paolo Zanotti-Fregonara
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, MD 20814, USA
| | - Jeih-San Liow
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, MD 20814, USA
| | - Xuefeng Yan
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, MD 20814, USA
| | - Sami S Zoghbi
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, MD 20814, USA
| | - Sridhar Goud Nerella
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, MD 20814, USA
| | - Sanjay Telu
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, MD 20814, USA
| | - Cheryl L Morse
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, MD 20814, USA
| | - Oscar Solis
- Biobehavioral Imaging and Molecular Neuropsychopharmacology Unit, Neuroimaging Research Branch, National Institute on Drug Abuse, National Institutes of Health, Baltimore, MD 21224, USA
| | - Juan L Gomez
- Biobehavioral Imaging and Molecular Neuropsychopharmacology Unit, Neuroimaging Research Branch, National Institute on Drug Abuse, National Institutes of Health, Baltimore, MD 21224, USA
| | - Daniel P Holt
- Department of Radiology, Johns Hopkins School of Medicine, Baltimore, MD 21205, USA
| | - Robert F Dannals
- Department of Radiology, Johns Hopkins School of Medicine, Baltimore, MD 21205, USA
| | - Alex C Cummins
- Laboratory of Neuropsychology, National Institute of Mental Health, National Institutes of Health, Bethesda, MD 20814, USA
| | - Robert B Innis
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, MD 20814, USA
| | - Victor W Pike
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, MD 20814, USA
| | - Barry J Richmond
- Laboratory of Neuropsychology, National Institute of Mental Health, National Institutes of Health, Bethesda, MD 20814, USA
| | - Michael Michaelides
- Biobehavioral Imaging and Molecular Neuropsychopharmacology Unit, Neuroimaging Research Branch, National Institute on Drug Abuse, National Institutes of Health, Baltimore, MD 21224, USA.
| | - Mark A G Eldridge
- Laboratory of Neuropsychology, National Institute of Mental Health, National Institutes of Health, Bethesda, MD 20814, USA.
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Liu F, Yao Y, Zhu B, Yu Y, Ren R, Hu Y. The novel imaging methods in diagnosis and assessment of cerebrovascular diseases: an overview. Front Med (Lausanne) 2024; 11:1269742. [PMID: 38660416 PMCID: PMC11039813 DOI: 10.3389/fmed.2024.1269742] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2023] [Accepted: 03/27/2024] [Indexed: 04/26/2024] Open
Abstract
Cerebrovascular diseases, including ischemic strokes, hemorrhagic strokes, and vascular malformations, are major causes of morbidity and mortality worldwide. The advancements in neuroimaging techniques have revolutionized the field of cerebrovascular disease diagnosis and assessment. This comprehensive review aims to provide a detailed analysis of the novel imaging methods used in the diagnosis and assessment of cerebrovascular diseases. We discuss the applications of various imaging modalities, such as computed tomography (CT), magnetic resonance imaging (MRI), positron emission tomography (PET), and angiography, highlighting their strengths and limitations. Furthermore, we delve into the emerging imaging techniques, including perfusion imaging, diffusion tensor imaging (DTI), and molecular imaging, exploring their potential contributions to the field. Understanding these novel imaging methods is necessary for accurate diagnosis, effective treatment planning, and monitoring the progression of cerebrovascular diseases.
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Affiliation(s)
- Fei Liu
- Neuroscience Intensive Care Unit, The Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Ying Yao
- Neuroscience Intensive Care Unit, The Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Bingcheng Zhu
- Department of Radiology, The Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Yue Yu
- Neuroscience Intensive Care Unit, The Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Reng Ren
- Neuroscience Intensive Care Unit, The Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Yinghong Hu
- Neuroscience Intensive Care Unit, The Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
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Nerella SG, Michaelides M, Minamimoto T, Innis RB, Pike VW, Eldridge MAG. PET reporter systems for the brain. Trends Neurosci 2023; 46:941-952. [PMID: 37734962 PMCID: PMC10592100 DOI: 10.1016/j.tins.2023.08.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Revised: 07/18/2023] [Accepted: 08/23/2023] [Indexed: 09/23/2023]
Abstract
Positron emission tomography (PET) can be used as a noninvasive method to longitudinally monitor and quantify the expression of proteins in the brain in vivo. It can be used to monitor changes in biomarkers of mental health disorders, and to assess therapeutic interventions such as stem cell and molecular genetic therapies. The utility of PET monitoring depends on the availability of a radiotracer with good central nervous system (CNS) penetration and high selectivity for the target protein. This review evaluates existing methods for the visualization of reporter proteins and/or protein function using PET imaging, focusing on engineered systems, and discusses possible approaches for future success in the development of high-sensitivity and high-specificity PET reporter systems for the brain.
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Affiliation(s)
- Sridhar Goud Nerella
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, MD 20892, USA.
| | - Michael Michaelides
- Biobehavioral Imaging and Molecular Neuropsychopharmacology Unit, National Institute on Drug Abuse, National Institutes of Health, Baltimore, MD 21224, USA
| | - Takafumi Minamimoto
- Department of Functional Brain Imaging, National Institutes for Quantum Science and Technology, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555, Japan
| | - Robert B Innis
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, MD 20892, USA
| | - Victor W Pike
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, MD 20892, USA
| | - Mark A G Eldridge
- Laboratory of Neuropsychology, National Institute of Mental Health, National Institutes of Health, Bethesda, MD, USA.
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