Search for extracellular vesicles that contribute to the reduction of radiation-induced tissue damage and application to radiation emergency medicine

2020 Fiscal Year Final Research Report

• Project/Area Number: 18K18190
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 63020:Radiation influence-related
• Research Institution: Hirosaki University
• Principal Investigator: Yamaguchi Masaru 弘前大学, 保健学研究科, 助教 (00782822)
• Project Period (FY): 2018-04-01 – 2021-03-31
• Keywords: 放射線被ばく / 急性放射線症候群 / 放射線緩和剤 / 放射線防護剤 / 細胞外小胞 / TPO受容体作動薬

Outline of Final Research Achievements

Survival of lethal dose radiation-exposed mice was confirmed by administration of TPO receptor agonists, and megakaryocyte hematopoiesis was observed in the spleen and lungs of surviving individuals. These are thought to be involved in the suppression of thrombocytopenia induced in acute radiation syndrome. In microarray analysis and PCR analysis using circulating RNA, the expression of miR-296-5p, miR-486-5p, and miR-328-3p associated with leukemia development was significantly suppressed by drug administration. It was suggested that it may be a miRNA that shows the damage induced by acute radiation syndrome and/or drug-induced mitigative information. Furthermore, it was suggested that serum exosomes in surviving individuals may have a life-saving effect on individuals exposed to lethal doses of radiation.

Free Research Field

放射線科学、放射線生物学、放射線防護学、被ばく医療、血液学、バイオマーカー

Academic Significance and Societal Importance of the Research Achievements

福島第一原発事故に伴う廃炉作業や除染作業に伴う被ばくリスク、更に核関連施設での事故や今後の核テロの脅威に対しても早急に対策を講じる必要がある。細胞外小胞には、由来する細胞の種類に依存した多様な種類の分子が含まれ、放射線損傷又は障害軽減応答に特異的な分子が内在している可能性があり、生体内分子を緊急被ばく医療対策に応用することを視野に入れた新たなアプローチとなる。さらに、放射線による組織障害を治癒再生する可能性が期待され、がん放射線治療に伴う副作用軽減の開発に向けた示唆が得られる。また、これまでに医療被ばくががん発症率向上に寄与するという報告もあり、医療被ばく対策の一助にもなり得る。