Analysis of hearing loss induced by a novel environmental factor to develop a preventive method

2018 Fiscal Year Final Research Report

• Project/Area Number: 16K08343
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Environmental and hygienic pharmacy
• Research Institution: Nagoya University
• Principal Investigator: Ohgami Nobutaka 名古屋大学, 医学系研究科, 講師 (80424919)
• Co-Investigator(Kenkyū-buntansha): 矢嶋 伊知朗 名古屋大学, 医学系研究科, 講師 (80469022) ; 飯田 真智子 愛知県心身障害者コロニー発達障害研究所, 周生期学部, 研究員 (60465515)
• Research Collaborator: KATO masashi
• Project Period (FY): 2016-04-01 – 2019-03-31
• Keywords: 難聴 / ラセン神経節 / 元素 / 神経変性

Outline of Final Research Achievements

There is limited information about an association between hearing loss and heavy metals. In previous studies, manganese has been shown to be detected in drinking well water. Also, exposure to manganese has been shown to cause age-related neurodegeneration. However, there is very limited information showing that oral exposure to manganese causes hearing loss in humans and mice. This study demonstrated that oral exposure to manganese via drinking water caused hearing loss with degeneration of spiral ganglion neurons in inner ears which involved decreased expression of c-Ret. This study also demonstrated the association of hearing loss and manganese levels in biological samples in humans.

Free Research Field

環境衛生学

Academic Significance and Societal Importance of the Research Achievements

従来、ヒトを対象にした疫学研究では病態との原因化学物質の関連は解析出来るものの、メカニズムに基づいた予知・予防方法を開発するには限界があった。マンガン（Mn）は必須微量元素であり、Mnの摂取量を制限するのは容易ではなく、全てのヒトにMnの慢性曝露による難聴リスクの可能性がある。本研究のヒトを対象にした疫学研究とマウスを対象にした実験研究の相補的アプローチにより、実験研究で得られたメカニズムをベースにした、Mnが誘発する難聴の予知・予防方法の開発につながる事が期待される。