A potential diagnostic marker for the drowning by investigating intrapulmonary mRNA and miRNA

2021 Fiscal Year Final Research Report

• Project/Area Number: 19K19487
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 58040:Forensics medicine-related
• Research Institution: Yokohama City University
• Principal Investigator: MAEDA Kazuho 横浜市立大学, 医学部, 助教 (40724761)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Keywords: 溺死 / 死因診断マーカー / micro RNA

Outline of Final Research Achievements

The diagnosis of drowning is one of the difficult problems in forensic science. In this study, we investigated a diagnostic marker for drowning, focused on intrapulmonary mRNA and miRNA. In the animal experiments, the expression of aqp5 was reduced and trpv4 was increased in freshwater drowning (FWD) significantly compared with that in saltwater drowning (SWD) and control mice. The miR-185-3p was predicted to bind to aqp5 and its expression was increased significantly in FWD. Consistent with the results in animals, a significant decrease of aqp5 and an increase of trpv4 and miR-185-3p expression was observed in FWD autopsy cases. Due to their small size, miRNAs are less susceptible to postmortem degradation than mRNA. Accordingly, the investigation of intrapulmonary miR-185-3p expression may differentiate between FWD and SWD.

Free Research Field

法医学

Academic Significance and Societal Importance of the Research Achievements

法医学では様々な事案についてその死因を究明することが重要な責務とされている。近年では全国で年間1000例程度の水中死体の法医解剖がなされている。水中死体は解剖所見ならびに諸臓器のプランクトン検査によって溺死と診断される。しかし、死後変化の進行や溺水場所のプランクトンの存在状況によっては溺死の診断根拠となる所見が乏しくなり、診断が困難となる。本研究ではそれらの問題点を解消すべく溺死特異的に発現変動するmRNAとmiRNAを同定し、分子生物学的な指標を用いた新たな溺死診断法の開発を行うことでこれまで診断が困難であった高度腐敗死体やプランクトンの少ない入浴死における溺死診断の実現を目指す。