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Tada T, Mizuno Y, Shibata Y, Yasui H, Kuge Y. Application of copper (I) selective ligands for PET imaging of reactive oxygen species through metabolic trapping. Nucl Med Biol 2024; 134-135:108914. [PMID: 38733873 DOI: 10.1016/j.nucmedbio.2024.108914] [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: 10/17/2023] [Revised: 03/29/2024] [Accepted: 04/24/2024] [Indexed: 05/13/2024]
Abstract
INTRODUCTION Reactive oxygen species (ROS) are attractive targets for clinical PET imaging. In this study, we hypothesized that PET imaging of ROS would be possible by using chelating ligands (L) that form stable complexes with copper (I) but not with copper (II), based on metabolic trapping. Namely, when [64Cu][CuI(L)2]+ is oxidized by ROS, the oxidized complex will release [64Cu]Cu2+. Then, the released [64Cu]Cu2+ will be trapped inside the cell, resulting in PET signal depending on the redox potential of ROS. To examine the potential of this novel molecular design for ROS imaging, we synthesized copper (I) complexes with bicinchoninic acid (BCA) disodium salt and bathocuproinedisulfonic acid (BCS) disodium salt and evaluated their reactivity with several kinds of ROS. In addition, the cellular uptake of [64Cu][CuI(BCS)2]3- and the stability of [64Cu][CuI(BCS)2]3- in a biological condition were also evaluated. METHODS [64Cu]Cu2+ was reduced to [64Cu]Cu+ by ascorbic acid and coordinated with BCA and BCS in the acetate buffer to synthesize [64Cu][CuI(BCA)2]3- and [64Cu][CuI(BCS)2]3-. The radiochemical yields were determined by thin-layer chromatography (TLC). After [64Cu][CuI(BCS)2]3- was incubated with hydroxyl radical, lipid peroxide, superoxide, and hydrogen peroxide, the percentage of released [64Cu]Cu2+ from the parent complex was evaluated by TLC. HT-1080 human fibrosarcoma cells were treated with 0.1 % Dimethyl sulfoxide (control), imidazole ketone erastin (IKE), or IKE + ferrostatin-1 (Fer-1). Then, the uptake of [64Cu][CuI(BCS)2]3- to HT-1080 cells in each group was evaluated as %Dose/mg protein. Lastly, [64Cu][CuI(BCS)2]3- was incubated in human plasma, and its intact ratio was determined by TLC. RESULTS The radiochemical yield of [64Cu][CuI(BCS)2]3- (86 ± 1 %) was higher than that of [64Cu][CuI(BCA)2]3- (44 ± 3 %). [64Cu][CuI(BCA)2]3- was unstable and partially decomposed on TLC. After [64Cu][CuI(BCS)2]3- was reacted with hydroxyl radical, lipid peroxide, and superoxide, 67 ± 2 %, 44 ± 13 %, and 22 ± 3 % of total radioactivity was detected as [64Cu]Cu2+, respectively. On the other hand, the reaction with hydrogen peroxide did not significantly increase the ratio of [64Cu]Cu2+ (4 ± 1 %). These results suggest that [64Cu][CuI(BCS)2]3- could be used for detecting high-redox-potential ROS such as hydroxyl radical and lipid peroxide with high selectivity. The cellular uptake values of [64Cu][CuI(BCS)2]3- in the control, IKE, and Fer-1 group were 42 ± 2, 54 ± 2, and 47 ± 5 %Dose/mg protein (n = 3), respectively, suggesting the ROS specific uptake of [64Cu][CuI(BCS)2]3-. On the other hand, the intact ratio after the incubation of [64Cu][CuI(BCS)2]3- in human plasma was 9 ± 5 %. CONCLUSION PET imaging of ROS would be possible by using a copper (I) selective ligand, based on metabolic trapping. Although improvement of the membrane permeability and the stability of copper (I) complexes is required, the present results pave the way for the development of novel 64Cu-labeled complexes for PET imaging of ROS.
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Affiliation(s)
- Tetsuro Tada
- Graduate School of Biomedical Science and Engineering, Hokkaido University, Hokkaido 060-0815, Japan
| | - Yuki Mizuno
- Central Institute of Isotope Science, Hokkaido University, Hokkaido 060-0815, Japan; Global Center for Biomedical Science and Engineering, Hokkaido University, Hokkaido 060-0815, Japan.
| | - Yuki Shibata
- Central Institute of Isotope Science, Hokkaido University, Hokkaido 060-0815, Japan
| | - Hironobu Yasui
- Faculty of Veterinary Medicine, Hokkaido University, Hokkaido 060-0818, Japan; One Health Research Center, Hokkaido University, Hokkaido 060-0818, Japan
| | - Yuji Kuge
- Central Institute of Isotope Science, Hokkaido University, Hokkaido 060-0815, Japan; Global Center for Biomedical Science and Engineering, Hokkaido University, Hokkaido 060-0815, Japan
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Huang L, Li Z, Zhang X. Radiotracers for Nuclear Imaging of Reactive Oxygen Species: Advances Made So Far. Bioconjug Chem 2022; 33:749-766. [PMID: 35467335 DOI: 10.1021/acs.bioconjchem.2c00050] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Reactive oxygen species (ROS) are a cluster of highly reactive and short-lived oxygen-containing molecules that lead to metabolic disorders where production exceeds catabolism in an organism. Many specific radiotracers for positron/single-photon emission tomography have been developed to reveal the discrepancy of ROS levels in normal and damaged tissues and further clarify the relationship between ROS and diseases. This review summarizes the advances achieved for the development of ROS radiotracers to date. The structure design, radiosynthesis, and imaging performance of existing radiotracers are discussed with the individual ROS-response mechanisms highlighted.
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Affiliation(s)
- Lumei Huang
- Center for Molecular Imaging and Translational Medicine, State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics, School of Public Health, Xiamen University, Xiang'An South Rd., Xiang'An district, Xiamen 361102, Fujian, China
| | - Zijing Li
- Center for Molecular Imaging and Translational Medicine, State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics, School of Public Health, Xiamen University, Xiang'An South Rd., Xiang'An district, Xiamen 361102, Fujian, China
| | - Xianzhong Zhang
- Center for Molecular Imaging and Translational Medicine, State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics, School of Public Health, Xiamen University, Xiang'An South Rd., Xiang'An district, Xiamen 361102, Fujian, China
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Yamasaki T, Sano K, Mukai T. Redox Monitoring in Nuclear Medical Imaging. Antioxid Redox Signal 2022; 36:797-810. [PMID: 34847731 DOI: 10.1089/ars.2021.0246] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Significance: The imbalance in redox homeostasis is known as oxidative stress, which is relevant to many diseases such as cancer, arteriosclerosis, and neurodegenerative disorders. Overproduction of reactive oxygen species (ROS) is one of the factors that trigger the redox state imbalance in vivo. The ROS have high reactivity and impair biomolecules, whereas antioxidants and antioxidant enzymes, such as ascorbate and glutathione, reduce the overproduction of ROS to rectify the redox imbalance. Owing to this, redox monitoring tools have been developed to understand the redox fluctuations in oxidative stress-related diseases. Recent Advances: In an attempt to monitor redox substances, including ROS and radical species, versatile modalities have been developed, such as electron spin resonance, chemiluminescence, and fluorescence. In particular, many fluorescent probes have been developed that are selective for ROS. This has significantly contributed to understanding the relevance of ROS in disease onset and progression. Critical Issues: To date, the dynamics of ROS and radical fluctuation in in vivo redox states remain unclear, and there are a few methods for the in vivo detection of redox fluctuations. Future Directions: In this review, we summarize the development of radiolabeled probes for monitoring redox-relevant species by nuclear medical imaging that is applicable in vivo. In the future, translational research is likely to be advanced through the development of highly sensitive and in vivo applicable detection methods, such as nuclear medical imaging, to clarify the underlying dynamics of ROS, radicals, and redox substances in many diseases. Antioxid. Redox Signal. 36, 797-810.
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Affiliation(s)
- Toshihide Yamasaki
- Laboratory of Biophysical Chemistry, Kobe Pharmaceutical University, Kobe, Japan
| | - Kohei Sano
- Laboratory of Biophysical Chemistry, Kobe Pharmaceutical University, Kobe, Japan
| | - Takahiro Mukai
- Laboratory of Biophysical Chemistry, Kobe Pharmaceutical University, Kobe, Japan
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Imaging of innate immunity activation in vivo with a redox-tuned PET reporter. Nat Biotechnol 2022; 40:965-973. [DOI: 10.1038/s41587-021-01169-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Accepted: 11/19/2021] [Indexed: 12/26/2022]
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Chen Z, Haider A, Chen J, Xiao Z, Gobbi L, Honer M, Grether U, Arnold SE, Josephson L, Liang SH. The Repertoire of Small-Molecule PET Probes for Neuroinflammation Imaging: Challenges and Opportunities beyond TSPO. J Med Chem 2021; 64:17656-17689. [PMID: 34905377 PMCID: PMC9094091 DOI: 10.1021/acs.jmedchem.1c01571] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Neuroinflammation is an adaptive response of the central nervous system to diverse potentially injurious stimuli, which is closely associated with neurodegeneration and typically characterized by activation of microglia and astrocytes. As a noninvasive and translational molecular imaging tool, positron emission tomography (PET) could provide a better understanding of neuroinflammation and its role in neurodegenerative diseases. Ligands to translator protein (TSPO), a putative marker of neuroinflammation, have been the most commonly studied in this context, but they suffer from serious limitations. Herein we present a repertoire of different structural chemotypes and novel PET ligand design for classical and emerging neuroinflammatory targets beyond TSPO. We believe that this Perspective will support multidisciplinary collaborations in academic and industrial institutions working on neuroinflammation and facilitate the progress of neuroinflammation PET probe development for clinical use.
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Affiliation(s)
- Zhen Chen
- Division of Nuclear Medicine and Molecular Imaging, Massachusetts General Hospital & Department of Radiology, Harvard Medical School, Boston, MA, 02114, United States
| | - Ahmed Haider
- Division of Nuclear Medicine and Molecular Imaging, Massachusetts General Hospital & Department of Radiology, Harvard Medical School, Boston, MA, 02114, United States
| | - Jiahui Chen
- Division of Nuclear Medicine and Molecular Imaging, Massachusetts General Hospital & Department of Radiology, Harvard Medical School, Boston, MA, 02114, United States
| | - Zhiwei Xiao
- Division of Nuclear Medicine and Molecular Imaging, Massachusetts General Hospital & Department of Radiology, Harvard Medical School, Boston, MA, 02114, United States
| | - Luca Gobbi
- Pharma Research and Early Development, F. Hoffmann-La Roche Ltd, CH-4070 Basel, Switzerland
| | - Michael Honer
- Pharma Research and Early Development, F. Hoffmann-La Roche Ltd, CH-4070 Basel, Switzerland
| | - Uwe Grether
- Pharma Research and Early Development, F. Hoffmann-La Roche Ltd, CH-4070 Basel, Switzerland
| | - Steven E. Arnold
- Department of Neurology and the Massachusetts Alzheimer’s Disease Research Center, Massachusetts General Hospital, Harvard Medical School, 114 16th Street, Charlestown, Massachusetts 02129, USA
| | - Lee Josephson
- Division of Nuclear Medicine and Molecular Imaging, Massachusetts General Hospital & Department of Radiology, Harvard Medical School, Boston, MA, 02114, United States
| | - Steven H. Liang
- Division of Nuclear Medicine and Molecular Imaging, Massachusetts General Hospital & Department of Radiology, Harvard Medical School, Boston, MA, 02114, United States
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Shukuri M, Uchino M, Sakamaki T, Onoe S, Hosoi R, Todoroki K, Arano Y, Sakai T, Akizawa H, Inoue O. Ex vivo imaging and analysis of ROS generation correlated with microglial activation in rat model with acute neuroinflammation induced by intrastriatal injection of LPS. Biochem Biophys Res Commun 2021; 584:101-106. [PMID: 34781201 DOI: 10.1016/j.bbrc.2021.11.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Accepted: 11/02/2021] [Indexed: 11/25/2022]
Abstract
Neuroinflammation and oxidative stress are hallmarks of neurodegenerative diseases. Microglia, the major important regulators of neuroinflammation, are activated in response to excessive generation of reactive oxygen species (ROS) from damaged cells and resulting in elevated and sustained damages. However, the relationship between microglia and ROS-regulatory system in the early stages of neuroinflammation prior to the appearance of neuronal damages have not been elucidated in detail. In this study, we analyzed the time-dependent changes in ROS generation during acute neuroinflammation in rats that were given an intrastriatal injection of lipopolysaccharide (LPS). We evaluated the effects of minocycline, an anti-inflammatory antibiotic, and N,N'-dimethylthiourea (DMTU), a radical scavenger, to understand the correlation between activated microglia and ROS generation. Ex vivo fluorescence imaging using dihydroethidium (DHE) clearly demonstrated an increased ROS level in the infused side of striatum in the rats treated with LPS. The level of ROS was changed in time-dependent manner, and the highest level of ROS was observed on day 3 after the infusion of LPS. Immunohistochemical studies revealed that time-dependent changes in ROS generation were well correlated to the presence of activated microglia. The inhibition of microglial activation by minocycline remarkably reduced ROS levels in the LPS-injected striatum, which indicated that the increased ROS generation caused by LPS was induced by activated microglia. DMTU decreased ROS generation and resulted in remarkable inhibitory effect on microglial activation. This study demonstrated that ROS generation during acute neuroinflammation induced by LPS was considerably associated with microglial activation, in an intact rat brain. The results provides a basis for understanding the interaction of ROS-regulatory system and activated microglia during neuroinflammation underlying neurodegenerative diseases.
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Affiliation(s)
- Miho Shukuri
- Laboratory of Physical Chemistry, Showa Pharmaceutical University, 3-3165 Higashi-Tamagawagakuen, Machida, Tokyo, 194-8543, Japan.
| | - Miyu Uchino
- Laboratory of Physical Chemistry, Showa Pharmaceutical University, 3-3165 Higashi-Tamagawagakuen, Machida, Tokyo, 194-8543, Japan
| | - Takafumi Sakamaki
- Laboratory of Physical Chemistry, Showa Pharmaceutical University, 3-3165 Higashi-Tamagawagakuen, Machida, Tokyo, 194-8543, Japan
| | - Satoru Onoe
- Laboratory of Physical Chemistry, Showa Pharmaceutical University, 3-3165 Higashi-Tamagawagakuen, Machida, Tokyo, 194-8543, Japan.
| | - Rie Hosoi
- Division of Health Sciences, Graduate School of Medicine, Osaka University, 1-7 Yamadaoka, Suita, Osaka, 565-0871, Japan.
| | - Kenichiro Todoroki
- Department of Analytical and Bio-Analytical Chemistry, School of Pharmaceutical Sciences, University of Shizuoka, 52-1 Yada, Suruga-ku, Shizuoka, 422-8526, Japan.
| | - Yasushi Arano
- Graduate School of Pharmaceutical Sciences, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba, 260-8675, Japan.
| | - Toshihiro Sakai
- Hanwa Intelligent Medical Center, Hanwa Daini Senboku Hospital, 3176 Fukaikitamachi, Naka-ku, Sakai, Osaka, 599-8271, Japan.
| | - Hiromichi Akizawa
- Laboratory of Physical Chemistry, Showa Pharmaceutical University, 3-3165 Higashi-Tamagawagakuen, Machida, Tokyo, 194-8543, Japan.
| | - Osamu Inoue
- Hanwa Intelligent Medical Center, Hanwa Daini Senboku Hospital, 3176 Fukaikitamachi, Naka-ku, Sakai, Osaka, 599-8271, Japan.
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Shan L, Li H, Min L, Weng Y, Wang X, Hu Y. Bischler-Napieralski Synthesis of 6-Alkynyl Phenanthridines Based on Tf 2O-Promoted Electrophilic Activation of N-Aryl-2-propynamides. J Org Chem 2021; 86:15726-15732. [PMID: 34618460 DOI: 10.1021/acs.joc.1c01543] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
An efficient method for the synthesis of 6-alkynyl phenanthridines was developed. The method offered the first example to use 2-propynamides as substrates in the Bischler-Napieralski reaction and to create alkynylnitrilium triflates as new active intermediates in organic synthesis.
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Affiliation(s)
- Lidong Shan
- Key Laboratory of Bioorganic Phosphorus Chemistry and Chemical Biology (Ministry of Education), Department of Chemistry, Tsinghua University, Beijing 100084, P.R. China
| | - Hongchen Li
- Key Laboratory of Bioorganic Phosphorus Chemistry and Chemical Biology (Ministry of Education), Department of Chemistry, Tsinghua University, Beijing 100084, P.R. China
| | - Lin Min
- Key Laboratory of Bioorganic Phosphorus Chemistry and Chemical Biology (Ministry of Education), Department of Chemistry, Tsinghua University, Beijing 100084, P.R. China
| | - Yunxiang Weng
- Key Laboratory of Bioorganic Phosphorus Chemistry and Chemical Biology (Ministry of Education), Department of Chemistry, Tsinghua University, Beijing 100084, P.R. China
| | - Xinyan Wang
- Key Laboratory of Bioorganic Phosphorus Chemistry and Chemical Biology (Ministry of Education), Department of Chemistry, Tsinghua University, Beijing 100084, P.R. China
| | - Yuefei Hu
- Key Laboratory of Bioorganic Phosphorus Chemistry and Chemical Biology (Ministry of Education), Department of Chemistry, Tsinghua University, Beijing 100084, P.R. China
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Niwa T, Nishibashi K, Sato H, Ujiie K, Yamashita K, Egami H, Hamashima Y. Structure Dependence in Asymmetric Deprotonative Fluorination and Fluorocyclization Reactions of Allylamine Derivatives with Linked Binaphthyl Dicarboxylate Phase-Transfer Catalyst. J Am Chem Soc 2021; 143:16599-16609. [PMID: 34590843 DOI: 10.1021/jacs.1c06783] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The asymmetric fluorofunctionalization of γ,γ-disubstituted allylamine derivatives (e.g., 3, 7, and 8) was investigated using our dianionic phase-transfer catalyst. Depending on the substituents on the alkene moiety, the reaction afforded chiral allylic fluorides and fluorinated dihydrooxazines in a highly enantioselective manner (up to 99% ee). The absolute stereochemistry of these products was found to be opposite to that in our previously reported fluorocyclization of γ-monosubstituted allylic amides (e.g., 13 and 14). To probe this interesting phenomenon, we investigated the influence of the substitution pattern of the alkene moiety on the reaction by means of NMR experiments and kinetic studies. The rate laws of the deprotonative fluorination and the fluorocyclization of γ,γ-disubstituted substrates were v = k[cat]0.6, while that of the fluorocyclization of γ-monosubstituted substrates was v = k[substrate][cat]0.4. An exponent of less than 1 suggests the involvement of an aggregated state of the catalyst ion pair in the catalytic cycle. Interestingly, a positive nonlinear effect was observed in the reactions of the γ,γ-disubstituted substrates, while a negative nonlinear effect was observed in the case of the γ-monosubstituted substrates. Thus, the reaction pathway depends on the presence or absence of an alkyl substituent at the γ position of the substrates, and on the basis of our mechanistic studies we propose that the active catalytic species for γ,γ-disubstituted substrates is a catalyst ion pair aggregate, whereas that for γ-monosubstituted substrates is the more active monomeric catalyst ion pair species, even though its concentration would be low.
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Affiliation(s)
- Tomoki Niwa
- School of Pharmaceutical Sciences, University of Shizuoka, 52-1 Yada, Suruga-ku, Shizuoka 422-8526, Japan
| | - Kousuke Nishibashi
- School of Pharmaceutical Sciences, University of Shizuoka, 52-1 Yada, Suruga-ku, Shizuoka 422-8526, Japan
| | - Hitomi Sato
- School of Pharmaceutical Sciences, University of Shizuoka, 52-1 Yada, Suruga-ku, Shizuoka 422-8526, Japan
| | - Kiyoshi Ujiie
- School of Pharmaceutical Sciences, University of Shizuoka, 52-1 Yada, Suruga-ku, Shizuoka 422-8526, Japan
| | - Kenji Yamashita
- School of Pharmaceutical Sciences, University of Shizuoka, 52-1 Yada, Suruga-ku, Shizuoka 422-8526, Japan
| | - Hiromichi Egami
- School of Pharmaceutical Sciences, University of Shizuoka, 52-1 Yada, Suruga-ku, Shizuoka 422-8526, Japan
| | - Yoshitaka Hamashima
- School of Pharmaceutical Sciences, University of Shizuoka, 52-1 Yada, Suruga-ku, Shizuoka 422-8526, Japan
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Hosoi R, Fujii Y, Hiroyuki O, Shukuri M, Nishiyama S, Kanazawa M, Todoroki K, Arano Y, Sakai T, Tsukada H, Inoue O. Evaluation of intracellular processes in quinolinic acid-induced brain damage by imaging reactive oxygen species generation and mitochondrial complex I activity. EJNMMI Res 2021; 11:99. [PMID: 34628558 PMCID: PMC8502189 DOI: 10.1186/s13550-021-00841-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Accepted: 09/17/2021] [Indexed: 11/10/2022] Open
Abstract
PURPOSE Our study aimed to elucidate the intracellular processes associated with quinolinic acid (QA)-induced brain injury by acquiring semiquantitative fluorescent images of reactive oxygen species (ROS) generation and positron emission tomography (PET) images of mitochondrial complex I (MC-I) activity. METHODS Ex vivo fluorescent imaging with dihydroethidium (DHE) and PET scans with 18F-BCPP-EF were conducted at 3 h and 24 h after QA injection into the rat striatum. Immunohistochemical studies were performed 24 h after QA injection into the rat brain using monoclonal antibodies against neuronal nuclei (NeuN) and CD11b. RESULTS A strong DHE-derived fluorescent signal was detected in a focal area within the QA-injected striatum 3 h after QA injection, and increased fluorescent signal spread throughout the striatum and parts of the cerebral cortex after 24 h. By contrast, 18F-BCPP-EF uptake in the QA-injected rat brain was unchanged after 3 h and markedly decreased after 24 h, not only in the striatum but also in the cerebral hemisphere. The fluorescent signal in the striatum 24 h after QA injection colocalised with microglial marker expression. CONCLUSIONS We successfully obtained functional images of focal ROS generation during the early period of excitotoxic injury, and microglial ROS generation and mitochondrial dysfunction were observed during the progression of the inflammatory response. Both ex vivo DHE imaging and in vivo 18F-BCPP-EF-PET were sufficiently sensitive to detect the respective processes of QA-induced brain damage. Our study contributes to the functional imaging of multiple events during the pathological process.
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Affiliation(s)
- Rie Hosoi
- Division of Health Sciences, Graduate School of Medicine, Osaka University, 1-7 Yamadaoka, Suita, Osaka, 565-0871, Japan.
| | - Yuka Fujii
- Division of Health Sciences, Graduate School of Medicine, Osaka University, 1-7 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Ohba Hiroyuki
- Central Research Laboratory, Hamamatsu Photonics K. K, 5000 Hirakuchi, Hamakita, Hamamatsu, Shizuoka, 434-8601, Japan
| | - Miho Shukuri
- Laboratory of Physical Chemistry, Showa Pharmaceutical University, 3-3165 Higashi-Tamagawagakuen, Machida, Tokyo, 194-8543, Japan
| | - Shingo Nishiyama
- Central Research Laboratory, Hamamatsu Photonics K. K, 5000 Hirakuchi, Hamakita, Hamamatsu, Shizuoka, 434-8601, Japan
| | - Masakatsu Kanazawa
- Central Research Laboratory, Hamamatsu Photonics K. K, 5000 Hirakuchi, Hamakita, Hamamatsu, Shizuoka, 434-8601, Japan
| | - Kenichiro Todoroki
- Department of Analytical and Bio-Analytical Chemistry, School of Pharmaceutical Sciences, University of Shizuoka, 52-1 Yada, Suruga-ku, Shizuoka, Shizuoka, 422-8526, Japan
| | - Yasushi Arano
- Graduate School of Pharmaceutical Sciences, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba, Chiba, 260-8675, Japan
| | - Toshihiro Sakai
- Hanwa Intelligent Medical Center, Hanwa Daini Senboku Hospital, 3176 Fukaikitamachi, Naka-ku, Sakai, Osaka, 599-8271, Japan
| | - Hideo Tsukada
- Central Research Laboratory, Hamamatsu Photonics K. K, 5000 Hirakuchi, Hamakita, Hamamatsu, Shizuoka, 434-8601, Japan
| | - Osamu Inoue
- Hanwa Intelligent Medical Center, Hanwa Daini Senboku Hospital, 3176 Fukaikitamachi, Naka-ku, Sakai, Osaka, 599-8271, Japan
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Zhou R, Ji B, Kong Y, Qin L, Ren W, Guan Y, Ni R. PET Imaging of Neuroinflammation in Alzheimer's Disease. Front Immunol 2021; 12:739130. [PMID: 34603323 PMCID: PMC8481830 DOI: 10.3389/fimmu.2021.739130] [Citation(s) in RCA: 46] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2021] [Accepted: 08/27/2021] [Indexed: 12/15/2022] Open
Abstract
Neuroinflammation play an important role in Alzheimer's disease pathogenesis. Advances in molecular imaging using positron emission tomography have provided insights into the time course of neuroinflammation and its relation with Alzheimer's disease central pathologies in patients and in animal disease models. Recent single-cell sequencing and transcriptomics indicate dynamic disease-associated microglia and astrocyte profiles in Alzheimer's disease. Mitochondrial 18-kDa translocator protein is the most widely investigated target for neuroinflammation imaging. New generation of translocator protein tracers with improved performance have been developed and evaluated along with tau and amyloid imaging for assessing the disease progression in Alzheimer's disease continuum. Given that translocator protein is not exclusively expressed in glia, alternative targets are under rapid development, such as monoamine oxidase B, matrix metalloproteinases, colony-stimulating factor 1 receptor, imidazoline-2 binding sites, cyclooxygenase, cannabinoid-2 receptor, purinergic P2X7 receptor, P2Y12 receptor, the fractalkine receptor, triggering receptor expressed on myeloid cells 2, and receptor for advanced glycation end products. Promising targets should demonstrate a higher specificity for cellular locations with exclusive expression in microglia or astrocyte and activation status (pro- or anti-inflammatory) with highly specific ligand to enable in vivo brain imaging. In this review, we summarised recent advances in the development of neuroinflammation imaging tracers and provided an outlook for promising targets in the future.
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Affiliation(s)
- Rong Zhou
- Department of Nephrology, Yangpu Hospital, School of Medicine, Tongji University, Shanghai, China
| | - Bin Ji
- Department of Radiopharmacy and Molecular Imaging, School of Pharmacy, Fudan University, Shanghai, China
| | - Yanyan Kong
- Positron Emission Tomography (PET) Center, Huashan Hospital, Fudan University, Shanghai, China
| | - Limei Qin
- Inner Mongolia Baicaotang Qin Chinese Mongolia Hospital, Hohhot, China
| | - Wuwei Ren
- School of Information Science and Technology, Shanghaitech University, Shanghai, China
| | - Yihui Guan
- Positron Emission Tomography (PET) Center, Huashan Hospital, Fudan University, Shanghai, China
| | - Ruiqing Ni
- Institute for Regenerative Medicine, University of Zurich, Zurich, Switzerland
- Institute for Biomedical Engineering, University of Zurich & Eidgenössische Technische Hochschule Zürich (ETH Zurich), Zurich, Switzerland
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Imaging Biomarkers for Monitoring the Inflammatory Redox Landscape in the Brain. Antioxidants (Basel) 2021; 10:antiox10040528. [PMID: 33800685 PMCID: PMC8065574 DOI: 10.3390/antiox10040528] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Revised: 03/21/2021] [Accepted: 03/25/2021] [Indexed: 12/27/2022] Open
Abstract
Inflammation is one key process in driving cellular redox homeostasis toward oxidative stress, which perpetuates inflammation. In the brain, this interplay results in a vicious cycle of cell death, the loss of neurons, and leakage of the blood–brain barrier. Hence, the neuroinflammatory response fuels the development of acute and chronic inflammatory diseases. Interrogation of the interplay between inflammation, oxidative stress, and cell death in neurological tissue in vivo is very challenging. The complexity of the underlying biological process and the fragility of the brain limit our understanding of the cause and the adequate diagnostics of neuroinflammatory diseases. In recent years, advancements in the development of molecular imaging agents addressed this limitation and enabled imaging of biomarkers of neuroinflammation in the brain. Notable redox biomarkers for imaging with positron emission tomography (PET) tracers are the 18 kDa translocator protein (TSPO) and monoamine oxygenase B (MAO–B). These findings and achievements offer the opportunity for novel diagnostic applications and therapeutic strategies. This review summarizes experimental as well as established pharmaceutical and biotechnological tools for imaging the inflammatory redox landscape in the brain, and provides a glimpse into future applications.
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Ikawa M, Okazawa H, Yoneda M. Molecular imaging for mitochondrial metabolism and oxidative stress in mitochondrial diseases and neurodegenerative disorders. Biochim Biophys Acta Gen Subj 2020; 1865:129832. [PMID: 33358866 DOI: 10.1016/j.bbagen.2020.129832] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2020] [Revised: 12/09/2020] [Accepted: 12/18/2020] [Indexed: 12/13/2022]
Abstract
BACKGROUND Increasing evidence from pathological and biochemical investigations suggests that mitochondrial metabolic impairment and oxidative stress play a crucial role in the pathogenesis of mitochondrial diseases, such as mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS) syndrome, and various neurodegenerative disorders. Recent advances in molecular imaging technology with positron emission tomography (PET) and functional magnetic resonance imaging (MRI) have accomplished a direct and non-invasive evaluation of the pathophysiological changes in living patients. SCOPE OF REVIEW In this review, we focus on the latest achievements of molecular imaging for mitochondrial metabolism and oxidative stress in mitochondrial diseases and neurodegenerative disorders. MAJOR CONCLUSIONS Molecular imaging with PET and MRI exhibited mitochondrial metabolic changes, such as enhanced glucose utilization with lactic acid fermentation, suppressed fatty acid metabolism, decreased TCA-cycle metabolism, impaired respiratory chain activity, and increased oxidative stress, in patients with MELAS syndrome. In addition, PET imaging clearly demonstrated enhanced cerebral oxidative stress in patients with Parkinson's disease or amyotrophic lateral sclerosis. The magnitude of oxidative stress correlated well with clinical severity in patients, indicating that oxidative stress based on mitochondrial dysfunction is associated with the neurodegenerative changes in these diseases. GENERAL SIGNIFICANCE Molecular imaging is a promising tool to improve our knowledge regarding the pathogenesis of diseases associated with mitochondrial dysfunction and oxidative stress, and this would facilitate the development of potential antioxidants and mitochondrial therapies.
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Affiliation(s)
- Masamichi Ikawa
- Second Department of Internal Medicine, Faculty of Medical Sciences, University of Fukui, Fukui, Japan; Biomedical Imaging Research Center, University of Fukui, Fukui, Japan; Department of Advanced Medicine for Community Healthcare, Faculty of Medical Sciences, University of Fukui, Fukui, Japan.
| | - Hidehiko Okazawa
- Biomedical Imaging Research Center, University of Fukui, Fukui, Japan
| | - Makoto Yoneda
- Biomedical Imaging Research Center, University of Fukui, Fukui, Japan; Faculty of Nursing and Social Welfare Science, Fukui Prefectural University, Fukui, 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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Egami H, Hotta R, Otsubo M, Rouno T, Niwa T, Yamashita K, Hamashima Y. Asymmetric Dearomatizing Fluoroamidation of Indole Derivatives with Dianionic Phase-Transfer Catalyst. Org Lett 2020; 22:5656-5660. [DOI: 10.1021/acs.orglett.0c02026] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Hiromichi Egami
- School of Pharmaceutical Sciences, University of Shizuoka, 52-1 Yada, Suruga-ku, Shizuoka 422-8526, Japan
| | - Ryo Hotta
- School of Pharmaceutical Sciences, University of Shizuoka, 52-1 Yada, Suruga-ku, Shizuoka 422-8526, Japan
| | - Minami Otsubo
- School of Pharmaceutical Sciences, University of Shizuoka, 52-1 Yada, Suruga-ku, Shizuoka 422-8526, Japan
| | - Taiki Rouno
- School of Pharmaceutical Sciences, University of Shizuoka, 52-1 Yada, Suruga-ku, Shizuoka 422-8526, Japan
| | - Tomoki Niwa
- School of Pharmaceutical Sciences, University of Shizuoka, 52-1 Yada, Suruga-ku, Shizuoka 422-8526, Japan
| | - Kenji Yamashita
- School of Pharmaceutical Sciences, University of Shizuoka, 52-1 Yada, Suruga-ku, Shizuoka 422-8526, Japan
| | - Yoshitaka Hamashima
- School of Pharmaceutical Sciences, University of Shizuoka, 52-1 Yada, Suruga-ku, Shizuoka 422-8526, Japan
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