Analysis of the functional roles of TRPM4 in the mammalian cochlea

2016 Fiscal Year Final Research Report

• Project/Area Number: 26462568
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Otorhinolaryngology
• Research Institution: Osaka University (2015-2016); Juntendo University (2014)
• Principal Investigator: Murata Junko 大阪大学, 医学系研究科, 招へい准教授 (80332740)
• Co-Investigator(Renkei-kenkyūsha): Okada Hiroko 順天堂大学, 医学部 耳鼻咽喉科学講座, 助教 (20433774)
• Project Period (FY): 2014-04-01 – 2017-03-31
• Keywords: TRPM4 / 内耳発生 / 内有毛細胞 / 血管条辺縁細胞 / 聴性脳幹反応

Outline of Final Research Achievements

We showed that in the cochleae of adult mice, the specific TRPM4-immuoreactivity was observed in the basolateral side of inner hair cells and in the apical side of marginal cells of stria vascularis by using the rabbit anti-TRPM4 polyclonal antibody. Additionally, the mRNA of TRPM4 was up-regulated both in the organ of Corti and in the stria vascularis at the stage when the auditory sense of mice is established. The examination using the auditory brain stem response (ABR) revealed that the hearing threshold was elevated in the TRPM4 knock-out mice compared to the wild type especially at the stage older than 17 weeks old. The spatial-temporal expression pattern of TRPM4 implicated that TRPM4, at least partially, may contribute the repolarization of inner hair cells and the transfer of potassium ion through the marginal cells to the endolymphatic space. The results of ABR suggest the TRPM4 gene may be related to the progressive hearing loss of the human.

Free Research Field

耳鼻咽喉科学