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Okazawa H, Nogami M, Ishida S, Makino A, Mori T, Kiyono Y, Ikawa M. PET/MRI multimodality imaging to evaluate changes in glymphatic system function and biomarkers of Alzheimer's disease. Sci Rep 2024; 14:12310. [PMID: 38811627 PMCID: PMC11137097 DOI: 10.1038/s41598-024-62806-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2024] [Accepted: 05/20/2024] [Indexed: 05/31/2024] Open
Abstract
The glymphatic system is considered to play a pivotal role in the clearance of disease-causing proteins in neurodegenerative diseases. This study employed MR diffusion tensor imaging (DTI) to evaluate glymphatic system function and its correlation with brain amyloid accumulation levels measured using [11C]Pittsburgh compound-B (PiB) PET/MRI. Fifty-six patients with mild cognitive impairment and early Alzheimer's disease (AD: 70 ± 11 y) underwent [11C]PiB PET/MRI to assess amyloid deposition and were compared with 27 age-matched cognitively normal volunteers (CN: 69 ± 10y). All participants were evaluated for cognitive function using the Mini Mental State Examination (MMSE) before [11C]PiB PET/MRI. DTI images were acquired during the PET/MRI scan with several other MR sequences. The DTI analysis along the perivascular space index (DTI-ALPS index) was calculated to estimate the functional activity of the glymphatic system. Centiloid scale was applied to quantify amyloid deposition levels from [11C]PiB PET images. All patients in the AD group showed positive [11C]PiB accumulation, whereas all CN participants were negative. ALPS-index for all subjects linearly correlated with PiB centiloid, MMSE scores, and hippocampal volume. The correlation between the ALPS-index and PiB accumulation was more pronounced than with any other biomarkers. These findings suggest that glymphatic system dysfunction is a significant factor in the early stages of Alzheimer's disease.
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Affiliation(s)
- Hidehiko Okazawa
- Biomedical Imaging Research Center, University of Fukui, 23-3, Matsuoka-Shimaizuki, Eiheiji-cho, Fukui, 910-1193, Japan.
| | - Munenobu Nogami
- Biomedical Imaging Research Center, University of Fukui, 23-3, Matsuoka-Shimaizuki, Eiheiji-cho, Fukui, 910-1193, Japan
- Department of Radiology, Kobe University Hospital, Kobe, Japan
| | | | - Akira Makino
- Biomedical Imaging Research Center, University of Fukui, 23-3, Matsuoka-Shimaizuki, Eiheiji-cho, Fukui, 910-1193, Japan
| | - Tetsuya Mori
- Biomedical Imaging Research Center, University of Fukui, 23-3, Matsuoka-Shimaizuki, Eiheiji-cho, Fukui, 910-1193, Japan
| | - Yasushi Kiyono
- Biomedical Imaging Research Center, University of Fukui, 23-3, Matsuoka-Shimaizuki, Eiheiji-cho, Fukui, 910-1193, Japan
| | - Masamichi Ikawa
- Biomedical Imaging Research Center, University of Fukui, 23-3, Matsuoka-Shimaizuki, Eiheiji-cho, Fukui, 910-1193, Japan
- Department of Community Health Science, Faculty of Medical Sciences, University of Fukui, Fukui, Japan
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Nishikawa Y, Takahashi N, Nishikawa S, Shimamoto Y, Nishimori K, Kobayashi M, Kimura H, Tsujikawa T, Kasuno K, Mori T, Kiyono Y, Okazawa H, Iwano M. Feasibility of Renal Blood Flow Measurement Using 64Cu-ATSM PET/MRI: A Quantitative PET and MRI Study. Diagnostics (Basel) 2023; 13:diagnostics13101685. [PMID: 37238171 DOI: 10.3390/diagnostics13101685] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2023] [Revised: 04/26/2023] [Accepted: 05/08/2023] [Indexed: 05/28/2023] Open
Abstract
This study aimed to evaluate the renal blood flow (RBF) in patients with chronic kidney disease (CKD) using 64Cu(II)-diacetyl-bis(4-methylthiosemicarbazonate) (64Cu-ATSM) for positron emission tomography (PET)/magnetic resonance imaging (MRI). We included five healthy controls (HCs) and ten patients with CKD. The estimated glomerular filtration rate (eGFR) was calculated from the serum creatinine (cr) and cystatin C (cys) levels. The estimated RBF (eRBF) was calculated using the eGFR, hematocrit, and filtration fraction. A single dose of 64Cu-ATSM (300-400 MBq) was administered for RBF evaluation, and a 40 min dynamic PET scan was performed with simultaneous arterial spin labeling (ASL) imaging. PET-RBF images were obtained from the dynamic PET images at 3 min after injection using the image-derived input function method. The mean eRBF values calculated from various eGFR values differed significantly between the patients and HCs; both groups also differed significantly in terms of the RBF values (mL/min/100 g) measured using PET (151 ± 20 vs. 124 ± 22, p < 0.05) and ASL-MRI (172 ± 38 vs. 125 ± 30, p < 0.001). The ASL-MRI-RBF was positively correlated with the eRBFcr-cys (r = 0.858, p < 0.001). The PET-RBF was positively correlated with the eRBFcr-cys (r = 0.893, p < 0.001). The ASL-RBF was positively correlated with the PET-RBF (r = 0.849, p < 0.001). 64Cu-ATSM PET/MRI demonstrated the reliability of PET-RBF and ASL-RBF by comparing them with eRBF. This is the first study to demonstrate that 64Cu-ATSM-PET is useful for assessing the RBF and is well correlated with ASL-MRI.
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Affiliation(s)
- Yudai Nishikawa
- Department of Nephrology, Faculty of Medical Sciences, University of Fukui, Fukui 910-1193, Japan
| | - Naoki Takahashi
- Department of Nephrology, Faculty of Medical Sciences, University of Fukui, Fukui 910-1193, Japan
| | - Sho Nishikawa
- Department of Nephrology, Faculty of Medical Sciences, University of Fukui, Fukui 910-1193, Japan
| | - Yuki Shimamoto
- Department of Nephrology, Faculty of Medical Sciences, University of Fukui, Fukui 910-1193, Japan
| | - Kazuhisa Nishimori
- Department of Nephrology, Faculty of Medical Sciences, University of Fukui, Fukui 910-1193, Japan
| | - Mamiko Kobayashi
- Department of Nephrology, Faculty of Medical Sciences, University of Fukui, Fukui 910-1193, Japan
| | - Hideki Kimura
- Department of Nephrology, Faculty of Medical Sciences, University of Fukui, Fukui 910-1193, Japan
| | - Tetsuya Tsujikawa
- Biomedical Imaging Research Center, University of Fukui, Fukui 910-1193, Japan
- Department of Radiology, Faculty of Medical Sciences, University of Fukui, Fukui 910-1193, Japan
| | - Kenji Kasuno
- Department of Nephrology, Faculty of Medical Sciences, University of Fukui, Fukui 910-1193, Japan
| | - Tetsuya Mori
- Biomedical Imaging Research Center, University of Fukui, Fukui 910-1193, Japan
| | - Yasushi Kiyono
- Biomedical Imaging Research Center, University of Fukui, Fukui 910-1193, Japan
| | - Hidehiko Okazawa
- Biomedical Imaging Research Center, University of Fukui, Fukui 910-1193, Japan
| | - Masayuki Iwano
- Department of Nephrology, Faculty of Medical Sciences, University of Fukui, Fukui 910-1193, Japan
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Eiro T, Miyazaki T, Hatano M, Nakajima W, Arisawa T, Takada Y, Kimura K, Sano A, Nakano K, Mihara T, Takayama Y, Ikegaya N, Iwasaki M, Hishimoto A, Noda Y, Miyazaki T, Uchida H, Tani H, Nagai N, Koizumi T, Nakajima S, Mimura M, Matsuda N, Kanai K, Takahashi K, Ito H, Hirano Y, Kimura Y, Matsumoto R, Ikeda A, Takahashi T. Dynamics of AMPA receptors regulate epileptogenesis in patients with epilepsy. Cell Rep Med 2023; 4:101020. [PMID: 37080205 DOI: 10.1016/j.xcrm.2023.101020] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2022] [Revised: 02/08/2023] [Accepted: 03/22/2023] [Indexed: 04/22/2023]
Abstract
The excitatory glutamate α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid receptors (AMPARs) contribute to epileptogenesis. Thirty patients with epilepsy and 31 healthy controls are scanned using positron emission tomography with our recently developed radiotracer for AMPARs, [11C]K-2, which measures the density of cell-surface AMPARs. In patients with focal-onset seizures, an increase in AMPAR trafficking augments the amplitude of abnormal gamma activity detected by electroencephalography. In contrast, patients with generalized-onset seizures exhibit a decrease in AMPARs coupled with increased amplitude of abnormal gamma activity. Patients with epilepsy had reduced AMPAR levels compared with healthy controls, and AMPARs are reduced in larger areas of the cortex in patients with generalized-onset seizures compared with those with focal-onset seizures. Thus, epileptic brain function can be regulated by the enhanced trafficking of AMPAR due to Hebbian plasticity with increased simultaneous neuronal firing and compensational downregulation of cell-surface AMPARs by the synaptic scaling.
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Affiliation(s)
- Tsuyoshi Eiro
- Department of Physiology, Yokohama City University Graduate School of Medicine, Yokohama 236-0004, Japan; Department of Psychiatry, Yokohama City University Graduate School of Medicine, Yokohama 236-0004, Japan
| | - Tomoyuki Miyazaki
- Department of Physiology, Yokohama City University Graduate School of Medicine, Yokohama 236-0004, Japan
| | - Mai Hatano
- Department of Physiology, Yokohama City University Graduate School of Medicine, Yokohama 236-0004, Japan
| | - Waki Nakajima
- Department of Physiology, Yokohama City University Graduate School of Medicine, Yokohama 236-0004, Japan
| | - Tetsu Arisawa
- Department of Physiology, Yokohama City University Graduate School of Medicine, Yokohama 236-0004, Japan
| | - Yuuki Takada
- Department of Physiology, Yokohama City University Graduate School of Medicine, Yokohama 236-0004, Japan
| | - Kimito Kimura
- Department of Physiology, Yokohama City University Graduate School of Medicine, Yokohama 236-0004, Japan
| | - Akane Sano
- Department of Physiology, Yokohama City University Graduate School of Medicine, Yokohama 236-0004, Japan
| | - Kotaro Nakano
- Department of Physiology, Yokohama City University Graduate School of Medicine, Yokohama 236-0004, Japan
| | - Takahiro Mihara
- Department of Health Data Science, Yokohama City University Graduate School of Data Science, Yokohama 236-0004, Japan
| | - Yutaro Takayama
- Department of Neurosurgery, Yokohama City University Graduate School of Medicine, Yokohama 236-0004, Japan
| | - Naoki Ikegaya
- Department of Neurosurgery, Yokohama City University Graduate School of Medicine, Yokohama 236-0004, Japan
| | - Masaki Iwasaki
- Department of Neurosurgery, National Center Hospital, National Center of Neurology and Psychiatry, Kodaira 187-8551, Japan
| | - Akitoyo Hishimoto
- Department of Psychiatry, Yokohama City University Graduate School of Medicine, Yokohama 236-0004, Japan
| | - Yoshihiro Noda
- Department of Neuropsychiatry, Keio University School of Medicine, Tokyo 160-0016, Japan
| | - Takahiro Miyazaki
- Department of Neuropsychiatry, Keio University School of Medicine, Tokyo 160-0016, Japan
| | - Hiroyuki Uchida
- Department of Neuropsychiatry, Keio University School of Medicine, Tokyo 160-0016, Japan
| | - Hideaki Tani
- Department of Neuropsychiatry, Keio University School of Medicine, Tokyo 160-0016, Japan
| | - Nobuhiro Nagai
- Department of Neuropsychiatry, Keio University School of Medicine, Tokyo 160-0016, Japan
| | - Teruki Koizumi
- Department of Neuropsychiatry, Keio University School of Medicine, Tokyo 160-0016, Japan
| | - Shinichiro Nakajima
- Department of Neuropsychiatry, Keio University School of Medicine, Tokyo 160-0016, Japan
| | - Masaru Mimura
- Department of Neuropsychiatry, Keio University School of Medicine, Tokyo 160-0016, Japan
| | - Nozomu Matsuda
- Department of Neurology, Fukushima Medical University, Fukushima 960-1295, Japan
| | - Kazuaki Kanai
- Department of Neurology, Fukushima Medical University, Fukushima 960-1295, Japan
| | - Kazuhiro Takahashi
- Advanced Clinical Research Center, Fukushima Global Medical Science Center, Fukushima Medical University, Fukushima 960-1295, Japan
| | - Hiroshi Ito
- Advanced Clinical Research Center, Fukushima Global Medical Science Center, Fukushima Medical University, Fukushima 960-1295, Japan; Department of Radiology and Nuclear Medicine, Fukushima Medical University, Fukushima 960-1295, Japan
| | - Yoji Hirano
- Department of Neuropsychiatry, Graduate School of Medical Sciences, Kyushu University, Fukuoka 812-8582, Japan; Department of Psychiatry, Division of Clinical Neuroscience, Faculty of Medicine, University of Miyazaki, 5200 Kihara, Kiyotake, Miyazaki 889-1692, Japan
| | - Yuichi Kimura
- Faculty of Informatics, Cyber Informatics Research Institute, Kindai University, Higashi-Osaka 577-8502, Japan
| | - Riki Matsumoto
- Division of Neurology, Kobe University Graduate School of Medicine, Kobe 650-0017, Japan
| | - Akio Ikeda
- Department of Epilepsy, Movement Disorders and Physiology, Kyoto University Graduate School of Medicine, Kyoto 606-8507, Japan
| | - Takuya Takahashi
- Department of Physiology, Yokohama City University Graduate School of Medicine, Yokohama 236-0004, Japan; The University of Tokyo, International Research Center for Neurointelligence, Tokyo 113-0033, Japan.
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Atay LO, Saka E, Akdemir UO, Yetim E, Balcı E, Arsava EM, Topcuoglu MA. Hybrid PET/MRI with Flutemetamol and FDG in Alzheimer's Disease Clinical Continuum. Curr Alzheimer Res 2023; 20:481-495. [PMID: 38050727 DOI: 10.2174/0115672050243131230925034334] [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: 12/28/2022] [Revised: 07/26/2023] [Accepted: 08/17/2023] [Indexed: 12/06/2023]
Abstract
AIMS We aimed to investigate the interaction between β -amyloid (Aβ) accumulation and cerebral glucose metabolism, cerebral perfusion, and cerebral structural changes in the Alzheimer's disease (AD) clinical continuum. BACKGROUND Utility of positron emission tomography (PET) / magnetic resonance imaging (MRI) hybrid imaging for diagnostic categorization of the AD clinical continuum including subjective cognitive decline (SCD), amnestic mild cognitive impairment (aMCI) and Alzheimer's disease dementia (ADD) has not been fully crystallized. OBJECTIVE To evaluate the interaction between Aβ accumulation and cerebral glucose metabolism, cerebral perfusion, and cerebral structural changes such as cortex thickness or cerebral white matter disease burden and to detect the discriminative yields of these imaging modalities in the AD clinical continuum. METHODS Fifty patients (20 women and 30 men; median age: 64 years) with clinical SCD (n=11), aMCI (n=17) and ADD (n=22) underwent PET/MRI with [18F]-fluoro-D-glucose (FDG) and [18F]- Flutemetamol in addition to cerebral blood flow (CBF) and quantitative structural imaging along with detailed cognitive assessment. RESULTS High Aβ deposition (increased temporal [18F]-Flutemetamol standardized uptake value ratio (SUVr) and centiloid score), low glucose metabolism (decreased temporal lobe and posterior cingulate [18F]-FDG SUVr), low parietal CBF and right hemispheric cortical thickness were independent predictors of low cognitive test performance. CONCLUSION Integrated use of structural, metabolic, molecular (Aβ) and perfusion (CBF) parameters contribute to the discrimination of SCD, aMCI, and ADD.
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Affiliation(s)
- Lutfiye Ozlem Atay
- Department of Nuclear Medicine, Faculty of Medicine, Gazi University, Ankara, Turkey
| | - Esen Saka
- Department of Neurology, Faculty of Medicine, Hacettepe University, Ankara, Turkey
| | - Umit Ozgur Akdemir
- Department of Nuclear Medicine, Faculty of Medicine, Gazi University, Ankara, Turkey
| | - Ezgi Yetim
- Department of Neurology, Faculty of Medicine, Hacettepe University, Ankara, Turkey
| | - Erdem Balcı
- Department of Nuclear Medicine, Faculty of Medicine, Gazi University, Ankara, Turkey
| | - Ethem Murat Arsava
- Department of Neurology, Faculty of Medicine, Hacettepe University, Ankara, Turkey
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Evaluation of (R)-[ 11C]PK11195 PET/MRI for Spinal Cord-Related Neuropathic Pain in Patients with Cervical Spinal Disorders. J Clin Med 2022; 12:jcm12010116. [PMID: 36614916 PMCID: PMC9821277 DOI: 10.3390/jcm12010116] [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: 11/25/2022] [Revised: 12/19/2022] [Accepted: 12/21/2022] [Indexed: 12/28/2022] Open
Abstract
Activated microglia are involved in secondary injury after acute spinal cord injury (SCI) and in development of spinal cord-related neuropathic pain (NeP). The aim of the study was to assess expression of translocator protein 18 kDa (TSPO) as an indicator of microglial activation and to investigate visualization of the dynamics of activated microglia in the injured spinal cord using PET imaging with (R)-[11C]PK11195, a specific ligand for TSPO. In SCI chimeric animal models, TSPO was expressed mainly in activated microglia. Accumulation of (R)-[3H]PK11195 was confirmed in autoradiography and its dynamics in the injured spinal cord were visualized by (R)-[11C]PK11195 PET imaging in the acute phase after SCI. In clinical application of (R)-[11C]PK11195 PET/MRI of the cervical spinal cord in patients with NeP related to cervical disorders, uptake was found in cases up to 10 months after injury or surgery. No uptake could be visualized in the injured spinal cord in patients with chronic NeP at more than 1 year after injury or surgery, regardless of the degree of NeP. However, a positive correlation was found between standardized uptake value ratio and the severity of NeP, suggesting the potential of clinical application for objective evaluation of chronic NeP.
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Okazawa H, Ikawa M, Tsujikawa T, Mori T, Makino A, Kiyono Y, Nakamoto Y, Kosaka H, Yoneda M. Cerebral Oxidative Stress in Early Alzheimer’s Disease Evaluated by 64Cu-ATSM PET/MRI: A Preliminary Study. Antioxidants (Basel) 2022; 11:antiox11051022. [PMID: 35624886 PMCID: PMC9138060 DOI: 10.3390/antiox11051022] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Revised: 05/16/2022] [Accepted: 05/20/2022] [Indexed: 12/17/2022] Open
Abstract
Oxidative stress imaging using diacetyl-bis (N4-methylthiosemicarbazone) (Cu-ATSM) was applied to the evaluation of patients with early Alzheimer’s disease (eAD). Ten eAD patients (72 ± 9 years) and 10 age-matched healthy controls (HCs) (73 ± 9 years) participated in this study. They underwent dynamic PET/MRI using 11C-PiB and 64Cu-ATSM with multiple MRI sequences. To evaluate cerebral oxidative stress, three parameters of 64Cu-ATSM PET were compared: standardized uptake value (SUV), tracer influx rate (Kin), and a rate constant k3. The input functions were estimated by the image-derived input function method. The relative differences were analyzed by statistical parametric mapping (SPM) using SUV and Kin images. All eAD patients had positive and HC subjects had negative PiB accumulation, and MMSE scores were significantly different between them. The 64Cu-ATSM accumulation tended to be higher in eAD than in HCs for both SUV and Kin. When comparing absolute values, eAD patients had a greater Kin in the posterior cingulate cortex and a greater k3 in the hippocampus compared with lobar cortical values of HCs. In SPM analysis, eAD had an increased left operculum and decreased bilateral hippocampus and anterior cingulate cortex compared to HCs. 64Cu-ATSM PET/MRI and tracer kinetic analysis elucidated cerebral oxidative stress in the eAD patients, particularly in the cingulate cortex and hippocampus.
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Affiliation(s)
- Hidehiko Okazawa
- Biomedical Imaging Research Center, University of Fukui, Fukui 910-1193, Japan; (M.I.); (T.T.); (T.M.); (A.M.); (Y.K.); (M.Y.)
- Correspondence: ; Tel.: +81-77661-8491
| | - Masamichi Ikawa
- Biomedical Imaging Research Center, University of Fukui, Fukui 910-1193, Japan; (M.I.); (T.T.); (T.M.); (A.M.); (Y.K.); (M.Y.)
- Second Department of Internal Medicine, Faculty of Medical Sciences, University of Fukui, Fukui 910-1193, Japan;
| | - Tetsuya Tsujikawa
- Biomedical Imaging Research Center, University of Fukui, Fukui 910-1193, Japan; (M.I.); (T.T.); (T.M.); (A.M.); (Y.K.); (M.Y.)
| | - Tetsuya Mori
- Biomedical Imaging Research Center, University of Fukui, Fukui 910-1193, Japan; (M.I.); (T.T.); (T.M.); (A.M.); (Y.K.); (M.Y.)
| | - Akira Makino
- Biomedical Imaging Research Center, University of Fukui, Fukui 910-1193, Japan; (M.I.); (T.T.); (T.M.); (A.M.); (Y.K.); (M.Y.)
| | - Yasushi Kiyono
- Biomedical Imaging Research Center, University of Fukui, Fukui 910-1193, Japan; (M.I.); (T.T.); (T.M.); (A.M.); (Y.K.); (M.Y.)
| | - Yasunari Nakamoto
- Second Department of Internal Medicine, Faculty of Medical Sciences, University of Fukui, Fukui 910-1193, Japan;
| | - Hirotaka Kosaka
- Department of Neuropsychiatry, Faculty of Medical Sciences, University of Fukui, Fukui 910-1193, Japan;
| | - Makoto Yoneda
- Biomedical Imaging Research Center, University of Fukui, Fukui 910-1193, Japan; (M.I.); (T.T.); (T.M.); (A.M.); (Y.K.); (M.Y.)
- Faculty of Nursing and Social Welfare Science, Fukui Prefectural University, Fukui 910-1195, Japan
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Tao AJ, Gadbois GE, Buczynski SA, Ferguson FM. Targeted protein degradation: Emerging concepts and protein state-specific targeting principles. Curr Opin Chem Biol 2022; 67:102114. [PMID: 35042023 PMCID: PMC9701552 DOI: 10.1016/j.cbpa.2021.102114] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Revised: 12/09/2021] [Accepted: 12/20/2021] [Indexed: 12/11/2022]
Abstract
Targeted protein degraders are heterobifunctional small molecules that link a target ligand or bait to an E3-ligase binder via a chemical spacer. Upon entering the cell, these ligands trigger the formation of a ternary complex between the target protein, degrader and E3-ligase, which leads to target polyubiquitination and proteasomal degradation. In recent years, TPD has expanded rapidly as a field, becoming the modality of choice in drug discovery and chemical probe development. This has been driven by the unique pharmacology of these molecules, which allows for fast and reversible knockdown of the target protein. Recent studies have demonstrated that degraders with specificity for a defined subpopulation of a protein-of-interest can be developed, giving rise to the emerging concept of protein state-specific targeting. In this article, we review advances towards developing degraders that differentiate between target protein subpopulations based on their; activation state, oligomerization state, cellular localization state, and cell type.
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Lorking N, Murray AD, O'Brien JT. The use of positron emission tomography/magnetic resonance imaging in dementia: A literature review. Int J Geriatr Psychiatry 2021; 36:1501-1513. [PMID: 34490651 DOI: 10.1002/gps.5586] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Revised: 04/22/2021] [Accepted: 05/17/2021] [Indexed: 11/08/2022]
Abstract
OBJECTIVES Positron emission tomography-magnetic resonance imaging (PET/MRI) is an emerging hybrid imaging system in clinical nuclear medicine. Research demonstrates a comparative utility to current unimodal and hybrid methods, including PET-computed tomography (PET/CT), in several medical subspecialities such as neuroimaging. The aim of this review is to critically evaluate the literature from 2016 to 2021 using PET/MRI for the investigation of patients with mild cognitive impairment or dementia, and discuss the evidence base for widening its application into clinical practice. METHODS A comprehensive literature search using the PubMed database was conducted to retrieve studies using PET/MRI in relation to the topics of mild cognitive impairment, dementia, or Alzheimer's disease between January 2016 and January 2021. This search strategy enabled studies on all dementia types to be included in the analysis. Studies were required to have a minimum of 10 human subjects and incorporate simultaneous PET/MRI. RESULTS A total of 116 papers were retrieved, with 39 papers included in the final selection. These were broadly categorised into reviews (12), technical/methodological papers (11) and new data studies (16). For the current review, discussion focused on findings from the new data studies. CONCLUSIONS PET/MRI offers additional insight into the underlying anatomical, metabolic and functional changes associated with dementia when compared with unimodal methods and PET/CT, particularly relating to brain regions including the hippocampus and default mode network. Furthermore, the improved diagnostic utility of PET/MRI, as reported by radiologists, offers improved classification of dementia patients, with important implications for clinical management.
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Affiliation(s)
- Nicole Lorking
- School of Medicine, University of Aberdeen, Scotland, UK
| | | | - John T O'Brien
- Department of Psychiatry, University of Cambridge, Cambridge, UK
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Abstract
PET/MR imaging is in routine clinical use and is at least as effective as PET/CT for oncologic and neurologic studies with advantages with certain PET radiopharmaceuticals and applications. In addition, whole body PET/MR imaging substantially reduces radiation dosages compared with PET/CT which is particularly relevant to pediatric and young adult population. For cancer imaging, assessment of hepatic, pelvic, and soft-tissue malignancies may benefit from PET/MR imaging. For neurologic imaging, volumetric brain MR imaging can detect regional volume loss relevant to cognitive impairment and epilepsy. In addition, the single-bed position acquisition enables dynamic brain PET imaging without extending the total study length which has the potential to enhance the diagnostic information from PET.
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Affiliation(s)
- Farshad Moradi
- Department of Radiology, Stanford University, 300 Pasteur Drive, H2200, Stanford, CA 94305, USA.
| | - Andrei Iagaru
- Department of Radiology, Stanford University, 300 Pasteur Drive, H2200, Stanford, CA 94305, USA
| | - Jonathan McConathy
- Department of Radiology, University of Alabama at Birmingham, 619 19th Street South, JT 773, Birmingham, AL 35249, USA
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Zeng HM, Han HB, Zhang QF, Bai H. Application of modern neuroimaging technology in the diagnosis and study of Alzheimer's disease. Neural Regen Res 2021; 16:73-79. [PMID: 32788450 PMCID: PMC7818875 DOI: 10.4103/1673-5374.286957] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Neurological abnormalities identified via neuroimaging are common in patients with Alzheimer’s disease. However, it is not yet possible to easily detect these abnormalities using head computed tomography in the early stages of the disease. In this review, we evaluated the ways in which modern imaging techniques such as positron emission computed tomography, single photon emission tomography, magnetic resonance spectrum imaging, structural magnetic resonance imaging, magnetic resonance diffusion tensor imaging, magnetic resonance perfusion weighted imaging, magnetic resonance sensitive weighted imaging, and functional magnetic resonance imaging have revealed specific changes not only in brain structure, but also in brain function in Alzheimer’s disease patients. The reviewed literature indicated that decreased fluorodeoxyglucose metabolism in the temporal and parietal lobes of Alzheimer’s disease patients is frequently observed via positron emission computed tomography. Furthermore, patients with Alzheimer’s disease often show a decreased N-acetylaspartic acid/creatine ratio and an increased myoinositol/creatine ratio revealed via magnetic resonance imaging. Atrophy of the entorhinal cortex, hippocampus, and posterior cingulate gyrus can be detected early using structural magnetic resonance imaging. Magnetic resonance sensitive weighted imaging can show small bleeds and abnormal iron metabolism. Task-related functional magnetic resonance imaging can display brain function activity through cerebral blood oxygenation. Resting functional magnetic resonance imaging can display the functional connection between brain neural networks. These are helpful for the differential diagnosis and experimental study of Alzheimer’s disease, and are valuable for exploring the pathogenesis of Alzheimer’s disease.
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Affiliation(s)
- Hong-Mei Zeng
- Department of Neurology, Third Affiliated Hospital of Guizhou Medical University, Duyun; Department of Neurology, Affiliated Hospital of Guizhou Medical University, Guiyang, Guizhou Province, China
| | - Hua-Bo Han
- Department of Radiology, Third Affiliated Hospital of Guizhou Medical University, Duyun, Guizhou Province, China
| | - Qi-Fang Zhang
- Key Laboratory of Endemic and Ethnic Diseases of Ministry of Education, and Key Laboratory of Medical Molecular Biology, Guizhou Medical University, Guiyang, Guizhou Province, China
| | - Hua Bai
- Department of Neurology, Third Affiliated Hospital of Guizhou Medical University, Duyun; Department of Neurology, Affiliated Hospital of Guizhou Medical University, Guiyang; Medical Experiment Center, Third Affiliated Hospital of Guizhou Medical University, Duyun, Guizhou Province, China
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Okazawa H, Ikawa M, Tsujikawa T, Makino A, Mori T, Kiyono Y, Kosaka H. Noninvasive Measurement of [ 11C]PiB Distribution Volume Using Integrated PET/MRI. Diagnostics (Basel) 2020; 10:diagnostics10120993. [PMID: 33255169 PMCID: PMC7760725 DOI: 10.3390/diagnostics10120993] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Revised: 11/18/2020] [Accepted: 11/22/2020] [Indexed: 11/16/2022] Open
Abstract
A noninvasive image-derived input function (IDIF) method using PET/MRI was applied to quantitative measurements of [11C] Pittsburgh compound-B (PiB) distribution volume (DV) and compared with other metrics. Fifty-three patients suspected of early dementia (71 ± 11 y) underwent 70 min [11C]PiB PET/MRI. Nineteen of them (68 ± 11 y) without head motion during the scan were enrolled in this study and compared with 16 age-matched healthy controls (CTL: 68 ± 11 y). The dynamic frames reconstructed from listmode PET data were used for DV calculation. IDIF with metabolite correction was applied to the Logan plot method, and DV was normalized into DV ratio (DVR) images using the cerebellar reference (DVRL). DVR and standardized uptake value ratio (SUVR) images were also calculated using the reference tissue graphical method (DVRr) and the 50–70 min static data with cerebellar reference, respectively. Cortical values were compared using the 3D-T1WI MRI segmentation. All patients were assigned to the early Alzheimer’s disease (eAD) group because of positive [11C]PiB accumulation. The correlations of regional values were better for DVRL vs. DVRr (r2 = 0.97) than for SUVR vs. DVRr (r2 = 0.88). However, all metrics clearly differentiated eAD from CTL with appropriate thresholds. Noninvasive quantitative [11C]PiB PET/MRI measurement provided equivalent DVRs with the two methods. SUVR images showed acceptable results despite inferior variability and image quality to DVR images.
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Affiliation(s)
- Hidehiko Okazawa
- Biomedical Imaging Research Center, University of Fukui, Eiheiji-cho 910-1193, Japan; (M.I.); (T.T.); (A.M.); (T.M.); (Y.K.)
- Correspondence: ; Tel.: +81-776-61-8491
| | - Masamichi Ikawa
- Biomedical Imaging Research Center, University of Fukui, Eiheiji-cho 910-1193, Japan; (M.I.); (T.T.); (A.M.); (T.M.); (Y.K.)
- Department of Advanced Medicine for Community Healthcare, Faculty of Medical Sciences, University of Fukui, Fukui 910-1193, Japan
| | - Tetsuya Tsujikawa
- Biomedical Imaging Research Center, University of Fukui, Eiheiji-cho 910-1193, Japan; (M.I.); (T.T.); (A.M.); (T.M.); (Y.K.)
| | - Akira Makino
- Biomedical Imaging Research Center, University of Fukui, Eiheiji-cho 910-1193, Japan; (M.I.); (T.T.); (A.M.); (T.M.); (Y.K.)
| | - Tetsuya Mori
- Biomedical Imaging Research Center, University of Fukui, Eiheiji-cho 910-1193, Japan; (M.I.); (T.T.); (A.M.); (T.M.); (Y.K.)
| | - Yasushi Kiyono
- Biomedical Imaging Research Center, University of Fukui, Eiheiji-cho 910-1193, Japan; (M.I.); (T.T.); (A.M.); (T.M.); (Y.K.)
| | - Hirotaka Kosaka
- Department of Neuropsychiatry, Faculty of Medical Sciences, University of Fukui, Fukui 910-1193, Japan;
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PET Imaging for Oxidative Stress in Neurodegenerative Disorders Associated with Mitochondrial Dysfunction. Antioxidants (Basel) 2020; 9:antiox9090861. [PMID: 32937849 PMCID: PMC7554831 DOI: 10.3390/antiox9090861] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Revised: 09/11/2020] [Accepted: 09/12/2020] [Indexed: 02/07/2023] Open
Abstract
Oxidative stress based on mitochondrial dysfunction is assumed to be the principal molecular mechanism for the pathogenesis of many neurodegenerative disorders. However, the effects of oxidative stress on the neurodegeneration process in living patients remain to be elucidated. Molecular imaging with positron emission tomography (PET) can directly evaluate subtle biological changes, including the redox status. The present review focuses on recent advances in PET imaging for oxidative stress, in particular the use of the Cu-ATSM radioligand, in neurodegenerative disorders associated with mitochondrial dysfunction. Since reactive oxygen species are mostly generated by leakage of excess electrons from an over-reductive state due to mitochondrial respiratory chain impairment, PET with 62Cu-ATSM, the accumulation of which depends on an over-reductive state, is able to image oxidative stress. 62Cu-ATSM PET studies demonstrated enhanced oxidative stress in the disease-related brain regions of patients with mitochondrial disease, Parkinson’s disease, and amyotrophic lateral sclerosis. Furthermore, the magnitude of oxidative stress increased with disease severity, indicating that oxidative stress based on mitochondrial dysfunction contributes to promoting neurodegeneration in these diseases. Oxidative stress imaging has improved our insights into the pathological mechanisms of neurodegenerative disorders, and is a promising tool for monitoring further antioxidant therapies.
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Massa F, Grisanti S, Brugnolo A, Doglione E, Orso B, Morbelli S, Bauckneht M, Origone P, Filippi L, Arnaldi D, De Carli F, Pardini M, Pagani M, Nobili F, Girtler N. The role of anterior prefrontal cortex in prospective memory: an exploratory FDG-PET study in early Alzheimer's disease. Neurobiol Aging 2020; 96:117-127. [PMID: 33002765 DOI: 10.1016/j.neurobiolaging.2020.09.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Revised: 08/25/2020] [Accepted: 09/01/2020] [Indexed: 12/31/2022]
Abstract
From previous studies in healthy volunteers the prefrontal regions are deeply involved in prospective memory (PM), although little is known about the functional neural basis of PM in prodromal Alzheimer's disease (AD). To this end, we retrospectively recruited 18 patients with mild cognitive impairment caused by AD and 23 matched healthy control subjects who had undergone 18F-fluorodeoxyglucose positron emission tomography and the PM-specific paradigm test. Brain metabolism was correlated with the PM score in the 2 groups separately to find those brain areas correlated with PM performance, which were then used as a hub for an inter-regional metabolic connectivity analyses (inter-regional correlation analysis). Of note, in mild cognitive impairment caused by AD, but not in healthy control subjects, PM score positively correlated with metabolic levels in the right anterior prefrontal cortex (middle and inferior frontal gyri), which disclosed a loss of interhemispheric connectivity in the inter-regional correlation analysis. According to our findings, the functioning of the right anterior prefrontal cortex and its interhemispheric metabolic connectivity is crucial in early AD to sustain PM performance, which deteriorates along with progressive metabolic failure of the interconnected areas.
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Affiliation(s)
- Federico Massa
- Department of Neuroscience, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health (DINOGMI), University of Genoa, Genoa, Italy.
| | - Stefano Grisanti
- Department of Neuroscience, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health (DINOGMI), University of Genoa, Genoa, Italy
| | - Andrea Brugnolo
- Department of Neuroscience, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health (DINOGMI), University of Genoa, Genoa, Italy; IRCCS Ospedale Policlinico San Martino, Genoa, Italy
| | | | - Beatrice Orso
- Department of Neuroscience, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health (DINOGMI), University of Genoa, Genoa, Italy
| | - Silvia Morbelli
- IRCCS Ospedale Policlinico San Martino, Genoa, Italy; Department of Health Science (DISSAL), University of Genoa, Italy
| | - Matteo Bauckneht
- IRCCS Ospedale Policlinico San Martino, Genoa, Italy; Department of Health Science (DISSAL), University of Genoa, Italy
| | - Paola Origone
- Department of Neuroscience, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health (DINOGMI), University of Genoa, Genoa, Italy; IRCCS Ospedale Policlinico San Martino, Genoa, Italy
| | - Laura Filippi
- Department of Neuroscience, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health (DINOGMI), University of Genoa, Genoa, Italy
| | - Dario Arnaldi
- Department of Neuroscience, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health (DINOGMI), University of Genoa, Genoa, Italy; IRCCS Ospedale Policlinico San Martino, Genoa, Italy
| | - Fabrizio De Carli
- Institute of Bioimaging and Molecular Physiology, Consiglio Nazionale delle Ricerche (CNR), Genoa, Italy
| | - Matteo Pardini
- Department of Neuroscience, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health (DINOGMI), University of Genoa, Genoa, Italy; IRCCS Ospedale Policlinico San Martino, Genoa, Italy
| | - Marco Pagani
- Institute of Cognitive Sciences and Technologies, Consiglio Nazionale delle Ricerche (CNR), Rome, Italy; Department of Medical Radiation Physics and Nuclear Medicine, Karolinska Hospital, Stockholm, Sweden
| | - Flavio Nobili
- Department of Neuroscience, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health (DINOGMI), University of Genoa, Genoa, Italy; IRCCS Ospedale Policlinico San Martino, Genoa, Italy
| | - Nicola Girtler
- Department of Neuroscience, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health (DINOGMI), University of Genoa, Genoa, Italy; IRCCS Ospedale Policlinico San Martino, Genoa, Italy
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