start-ver=1.4 cd-journal=joma no-vol=57 cd-vols= no-issue= article-no= start-page=13381 end-page=13384 dt-received= dt-revised= dt-accepted= dt-pub-year=2021 dt-pub=20211116 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=cis-3-Azido-2-methoxyindolines as safe and stable precursors to overcome the instability of fleeting 3-azidoindoles en-subtitle= kn-subtitle= en-abstract= kn-abstract=Use of 3-azidoindoles in organic synthesis remains a difficult task owing to their instabilities. Herein, we report a general and concise approach for tackling this problem by using 3-azidoindole surrogates. The surrogates are bench-stable, presumably due to the observed intramolecular O-N-beta bonding. The resultant fleeting intermediates undergo capturing in situ to afford 3-substitued indoles through formal ipso-substitution of the azide group by nucleophiles. In these investigations, we found that the fleeting 3-azidoindoles show a C3-electrophilic character for the first time. en-copyright= kn-copyright= en-aut-name=YamashiroToshiki en-aut-sei=Yamashiro en-aut-mei=Toshiki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=AbeTakumi en-aut-sei=Abe en-aut-mei=Takumi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=TaniokaMasaru en-aut-sei=Tanioka en-aut-mei=Masaru kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=KaminoShinichiro en-aut-sei=Kamino en-aut-mei=Shinichiro kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= en-aut-name=SawadaDaisuke en-aut-sei=Sawada en-aut-mei=Daisuke kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=5 ORCID= affil-num=1 en-affil=Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University kn-affil= affil-num=2 en-affil=Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University kn-affil= affil-num=3 en-affil=School of Pharmaceutical Sciences, Aichi Gakuin University kn-affil= affil-num=4 en-affil=School of Pharmaceutical Sciences, Aichi Gakuin University kn-affil= affil-num=5 en-affil=Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University kn-affil= END start-ver=1.4 cd-journal=joma no-vol=28 cd-vols= no-issue=1 article-no= start-page=115189 end-page= dt-received= dt-revised= dt-accepted= dt-pub-year=2020 dt-pub=20200101 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Development and characterization of a 68Ga-labeled A20FMDV2 peptide probe for the PET imaging of αvβ6 integrin-positive pancreatic ductal adenocarcinoma en-subtitle= kn-subtitle= en-abstract= kn-abstract=Pancreatic ductal adenocarcinoma (PDAC) is known to be one of the most lethal cancers. Since the majority of patients are diagnosed at an advanced stage, development of a detection method for PDAC at an earlier stage of disease progression is strongly desirable. Integrin αVβ6 is a promising target for early PDAC detection because its expression increases during precancerous changes. The present study aimed to develop an imaging probe for positron emission tomography (PET) which targets αVβ6 integrin-positive PDAC. We selected A20FMDV2 peptide, which binds specifically to αvβ6 integrin, as a probe scaffold, and 68Ga as a radioisotope. A20FMDV2 peptide has not been previously labeled with 68Ga. A cysteine residue was introduced to the N-terminus of the probe at a site-specific conjugation of maleimide-NOTA (mal-NOTA) chelate. Different numbers of glycine residues were also introduced between cysteine and the A20FMDV2 sequence as a spacer in order to reduce the steric hindrance of the mal-NOTA on the binding probe to αVβ6 integrin. In vitro, the competitive binding assay revealed that probes containing a 6-glycine linker ([natGa]CG6 and [natGa]Ac-CG6) showed high affinity to αVβ6 integrin. Both probes could be labeled by 67/68Ga with high radiochemical yield (>50%) and purity (>98%). On biodistribution analysis, [67Ga]Ac-CG6 showed higher tumor accumulation, faster blood clearance, and lower accumulation in the surrounding organs of pancreas than did [67Ga]CG6. The αVβ6 integrin-positive xenografts were clearly visualized by PET imaging with [68Ga]Ac-CG6. The intratumoral distribution of [68Ga]Ac-CG6 coincided with the αVβ6 integrin-positive regions detected by immunohistochemistry. Thus, [68Ga]Ac-CG6 is a useful peptide probe for the imaging of αVβ6 integrin in PDAC. en-copyright= kn-copyright= en-aut-name=UiTakashi en-aut-sei=Ui en-aut-mei=Takashi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=UedaMasashi en-aut-sei=Ueda en-aut-mei=Masashi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=HigakiYusuke en-aut-sei=Higaki en-aut-mei=Yusuke kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=KaminoShinichiro en-aut-sei=Kamino en-aut-mei=Shinichiro kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= en-aut-name=SanoKohei en-aut-sei=Sano en-aut-mei=Kohei kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=5 ORCID= en-aut-name=KimuraHiroyuki en-aut-sei=Kimura en-aut-mei=Hiroyuki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=6 ORCID= en-aut-name=SajiHideo en-aut-sei=Saji en-aut-mei=Hideo kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=7 ORCID= en-aut-name=EnomotoShuichi en-aut-sei=Enomoto en-aut-mei=Shuichi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=8 ORCID= affil-num=1 en-affil=Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama University kn-affil= affil-num=2 en-affil=Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama University kn-affil= affil-num=3 en-affil=Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama Universit kn-affil= affil-num=4 en-affil=Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama University kn-affil= affil-num=5 en-affil=Graduate School of Pharmaceutical Sciences, Kyoto University kn-affil= affil-num=6 en-affil=Graduate School of Pharmaceutical Sciences, Kyoto University kn-affil= affil-num=7 en-affil=Graduate School of Pharmaceutical Sciences, Kyoto University kn-affil= affil-num=8 en-affil=RIKEN Center for Life Science Technologies kn-affil= en-keyword=αvβ6 integrin kn-keyword=αvβ6 integrin en-keyword=Pancreatic ductal adenocarcinoma kn-keyword=Pancreatic ductal adenocarcinoma en-keyword=Gallium-68 kn-keyword=Gallium-68 en-keyword=A20FMDV2 peptide kn-keyword=A20FMDV2 peptide en-keyword=Positron emission tomography kn-keyword=Positron emission tomography END start-ver=1.4 cd-journal=joma no-vol=43 cd-vols= no-issue=6 article-no= start-page=372 end-page=378 dt-received= dt-revised= dt-accepted= dt-pub-year=2016 dt-pub=201606 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Noninvasive evaluation of nicotinic acetylcholine receptor availability in mouse brain using single-photon emission computed tomography with [(123)I]5IA. en-subtitle= kn-subtitle= en-abstract= kn-abstract=INTRODUCTION:
Nicotinic acetylcholine receptors (nAChRs) are of great interest because they are implicated in higher brain functions. Nuclear medical imaging is one of the useful techniques for noninvasive evaluation of physiological and pathological function in living subjects. Recent progress in nuclear medical imaging modalities enables the clear visualization of the organs of small rodents. Thus, translational research using nuclear medical imaging in transgenic mice has become possible and helps to elucidate human disease pathology. However, imaging of α4β2 nAChRs in the mouse brain has not yet been performed. The purpose of this study was to assess the feasibility of single-photon emission computed tomography (SPECT) with 5-[(123)I]iodo-3-[2(S)-azetidinylmethoxy]pyridine ([(123)I]5IA) for evaluating α4β2 nAChR availability in the mouse brain.
METHODS:
A 60-min dynamic SPECT imaging session of α4β2 nAChRs in the mouse brain was performed. The regional distribution of radioactivity in the SPECT images was compared to the density of α4β2 nAChRs measured in an identical mouse. Alteration of nAChR density in the brains of Tg2576 mice was also evaluated.
RESULTS:
The mouse brain was clearly visualized by [(123)I]5IA-SPECT and probe accumulation was significantly inhibited by pretreatment with (-)-nicotine. The regional distribution of radioactivity in SPECT images showed a significant positive correlation with α4β2 nAChR density measured in an identical mouse brain. Moreover, [(123)I]5IA-SPECT was able to detect the up-regulation of α4β2 nAChRs in the brains of Tg2576 transgenic mice.
CONCLUSIONS:
[(123)I]5IA-SPECT imaging would be a promising tool for evaluating α4β2 nAChR availability in the mouse brain and may be useful in translational research focused on nAChR-related diseases. en-copyright= kn-copyright= en-aut-name=MatsuuraYuki en-aut-sei=Matsuura en-aut-mei=Yuki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=UedaMasashi en-aut-sei=Ueda en-aut-mei=Masashi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=HigakiYusuke en-aut-sei=Higaki en-aut-mei=Yusuke kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=WatanabeKeiko en-aut-sei=Watanabe en-aut-mei=Keiko kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= en-aut-name=HabaraShogo en-aut-sei=Habara en-aut-mei=Shogo kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=5 ORCID= en-aut-name=KaminoShinichiro en-aut-sei=Kamino en-aut-mei=Shinichiro kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=6 ORCID= en-aut-name=SajiHideo en-aut-sei=Saji en-aut-mei=Hideo kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=7 ORCID= en-aut-name=EnomotoShuichi en-aut-sei=Enomoto en-aut-mei=Shuichi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=8 ORCID= affil-num=1 en-affil=Department of Pharmaceutical Analytical Chemistry, Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama University kn-affil= affil-num=2 en-affil=Department of Pharmaceutical Analytical Chemistry, Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama University kn-affil= affil-num=3 en-affil=Department of Pharmaceutical Analytical Chemistry, Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama University kn-affil= affil-num=4 en-affil=Department of Pharmaceutical Analytical Chemistry, Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama University kn-affil= affil-num=5 en-affil=Department of Pharmaceutical Analytical Chemistry, Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama University kn-affil= affil-num=6 en-affil=Department of Pharmaceutical Analytical Chemistry, Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama University kn-affil= affil-num=7 en-affil=Department of Patho-Functional Bioanalysis, Graduate School of Pharmaceutical Sciences, Kyoto University kn-affil= affil-num=8 en-affil=Department of Pharmaceutical Analytical Chemistry, Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama University kn-affil= en-keyword=5-[(123)I]iodo-3-(2(S)-azetidinylmethoxy)pyridine ([(123)I]5IA) kn-keyword=5-[(123)I]iodo-3-(2(S)-azetidinylmethoxy)pyridine ([(123)I]5IA) en-keyword=Alzheimer's disease kn-keyword=Alzheimer's disease en-keyword=Mouse kn-keyword=Mouse en-keyword=Nicotinic acetylcholine receptor (nAChR) kn-keyword=Nicotinic acetylcholine receptor (nAChR) en-keyword=Single-photon emission computed tomography (SPECT) kn-keyword=Single-photon emission computed tomography (SPECT) en-keyword=Tg2576 kn-keyword=Tg2576 END