| 論文種別 | 原著(症例報告除く) |
| 言語種別 | 英語 |
| 査読の有無 | 査読あり |
| 表題 | Comparison of 125I- and 111In-labeled peptide probes for in vivo detection of oxidized low-density lipoprotein in atherosclerotic plaques |
| 掲載誌名 | 正式名：Annals of Nuclear Medicine ISSNコード：1864-6433 |
| 出版社 | Springer Tokyo |
| 巻・号・頁 | 32(6),pp.1-5 |
| 著者・共著者 | Takashi Temma,Naoya Kondo,Keiko Yoda,Kantaro Nishigori,Satoru Onoe,Masashi Shiomi,Masahiro Ono,Hideo Saji |
| 発行年月 | 2018/04/12 |
| 概要 | Objective: Oxidized low-density lipoprotein (OxLDL) plays a pivotal role in atherosclerotic plaque destabilization, which suggests its potential as a nuclear medical imaging target. We previously developed radioiodinated 125I-AHP7, a peptide probe carrying a 7-residue sequence from the OxLDL-binding protein Asp-hemolysin, for specific OxLDL imaging. Although 125I-AHP7 recognized OxLDL, it had low stability. Thus, to improve stability, we designed radiolabeled 22-residue peptide probes, 125I-AHP22 and 111In-AHP22, which include the entire AHP7 sequence, and evaluated the stability, activity, and applications of these probes in vitro and in vivo. Methods: Probes consisting of a 21-residue peptide derived from the Asp-hemolysin sequence and an N-terminal Cys or aminohexanoic acid for labeling with 125I-N-(3-iodophenyl)maleimide or 111In diethylene triamine pentaacetic acid were termed 125I-AHP22 and 111In-AHP22. An in vitro-binding inhibition assay with OxLDL was performed using 125I-AHP7 as a radiotracer. Radioactivity accumulation in the atherosclerotic aorta and plasma intact fraction was evaluated 30 min after intravenous administration of probes in myocardial infarction-prone Watanabe heritable hyperlipidemic (WHHLMI) rabbits. Results: 125I-AHP22 and 111In-AHP22 were synthesized in ~ 360 and 60 min, respectively, with > 98% radiochemical purities after RP-HPLC purification. An in vitro-binding assay revealed similar or greater inhibition of OxLDL binding by both In-AHP22 and I-AHP22 compared to I-AHP7. The fraction of intact 125I-AHP22 and 111In-AHP22 in plasma was estimated to be approximately tenfold higher than that of 125I-AHP7. Both probes were rapidly cleared from the blood. 111In-AHP22 had a 2.3-fold higher accumulation in WHHLMI rabbit aortas compared to control rabbits, which was similar to 125I-AHP7. However, 125I-AHP22 accumulated to similar levels in aortas of WHHLMI and control rabbits due to high nonspecific accumulation in normal aortas that could be due to high lipophilicity. Conclusions: 111In-AHP22, easily prepared within 1 h, showed moderate affinity for OxLDL, high stability in vivo, and high accumulation in atherosclerotic aortas. 111In-AHP22 could be a potential lead compound to develop future effective OxLDL imaging probes. |
| DOI | 10.1007/s12149-018-1255-y |
| PMID | 29651757 |