Functional analysis for sexual maturation in extracellular vesicles using miRNA knockdown schistosomes

2018 Fiscal Year Final Research Report

• Project/Area Number: 16K08756
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Parasitology (including sanitary zoology)
• Research Institution: Tokyo Medical and Dental University
• Principal Investigator: KUMAGAI Takashi 東京医科歯科大学, 大学院医歯学総合研究科, 助教 (40369054)
• Research Collaborator: SHIMOGAWARA Rieko ; OHTA Nobuo
• Project Period (FY): 2016-04-01 – 2019-03-31
• Keywords: 住血吸虫 / 細胞外小胞 / miR-Bantam / miRNA Tough Decoy

Outline of Final Research Achievements

Schistosomiasis is an endemic parasite in the tropics and subtropics, and, unlike hermaphrodite flukes, it is an evolutionarily early organism in which male and female worms are separated. The schistosomes which become pairing between male and female in the blood vessel, ingest the red blood cells to induce growth, sexual maturation and oviposition. We have found that release of cells called extracellular vesicles which are involved in signal transduction between individuals, were increased by pairing of males and females and ingestion of red blood cells. In particular, it has been found that the amount of gene expression regulatory molecule called miRNA in the vesicle also increases. In this research project, we observed the function of miRNA by simultaneously expressing an inhibitory molecule called miRNA decoy that suppresses the expression of this miRNA.

Free Research Field

寄生虫学

Academic Significance and Societal Importance of the Research Achievements

住血吸虫症は年間２億人以上の感染者と、30万人近くの死亡者を引き起こし、顧みられない熱帯病の一つとしても注目されている寄生虫疾患である。効果的な治療薬はあるものの、ワクチンは存在せず、なかなか根絶に至っていない。この病気の主な原因は成虫の産み出す虫卵が、肝臓や腸管組織に詰まり周辺組織を壊死させることで引き起こされる。住血吸虫は雌雄異体の寄生虫としては、進化的にも初期の生物であり、産卵誘導に必要な雌雄コミュニケーションはシンプルかつ、基本的であると考えられる。細胞外小胞を用いた雌雄コミュニケーションへの理解は、生物学だけでなく、医学上の住血吸虫対策においても意義があると考えられる。