Live imaging of the cochlear mitochondria and reactive oxygen spcies

• Project/Area Number: 23592475
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Otorhinolaryngology
• Research Institution: The University of Tokyo
• Principal Investigator: KIKKAWA Yayoi S. 東京大学, 医学部附属病院, 病院診療医 (00452350)
• Co-Investigator(Kenkyū-buntansha): SAKAMOTO Takashi 東京大学, 医学部附属病院, 講師 (50323548)
• Project Period (FY): 2012-04-01 – 2015-03-31
• Project Status: Completed (Fiscal Year 2014)
• Budget Amount: ¥5,200,000 (Direct Cost: ¥4,000,000、Indirect Cost: ¥1,200,000); Fiscal Year 2013: ¥1,560,000 (Direct Cost: ¥1,200,000、Indirect Cost: ¥360,000); Fiscal Year 2012: ¥1,560,000 (Direct Cost: ¥1,200,000、Indirect Cost: ¥360,000); Fiscal Year 2011: ¥2,080,000 (Direct Cost: ¥1,600,000、Indirect Cost: ¥480,000)
• Keywords: 耳科学 / 抗加齢医学 / 内耳 / 有毛細胞 / 難聴

Outline of Final Research Achievements

In this study, we developed a real-time imaging method of reactive oxygen species (ROS) in the live inner ears (cochlea). Also, we analyzed the mechanisms of cochlear protective agents against ROS.
[Contents] (1) Live ROS imaging in the cochlea. (a) Mouse cochlear explants were imaged using an ultra-high-speed confocal microscope (Nikon A1R). Tomographic images were then 3D reconstructed to pinpoint the active position for producing inner ear ROS. (b) Live, in vivo ROS production was imaged using cochlear-exposed guinea pigs. (2) Monitoring mitochondria distribution in the damaged inner ear: Mouse cochlear explants were incubated in medium containing various concentrations of cisplatin, and mitochondria distribution and ROS production were examined. (3) Elucidation of anti-ROS mechanism in the inner ear: Mouse cochlear explants were cultured in cisplatin-containing medium with hydrogen gas dissolved directly into the media and ROS production and hair cell survival was evaluated.

Research Products

• [Journal Article] Prognostic factors for long-term hearing preservation after canal-tympanoplasty for congenital aural atresia. (2015)
  • Author(s): Sakamoto T, Kikuta S, Kikkawa YS, Kinoshita M, Saito Y, Kobayashi K, Kakigi A, Suzuki M, Yamasoba T
  • Journal Title: Europian Archives of Otorhinolaryngology Volume: 272 Issue: 11 Pages: 3151-6
  • DOI: 10.1007/s00405-014-3164-6
  • Peer Reviewed
• [Journal Article] Hydrogen protects auditory hair cells from cisplatin-induced free radicals (2014)
  • Author(s): Kikkawa Y. S., Nakagawa T., Taniguchi M., and Ito J
  • Journal Title: Neurosci Lett Volume: 579 Pages: 125-129
  • DOI: 10.1016/j.neulet.2014.07.025
  • NAID: 120005466694
  • Peer Reviewed
• [Journal Article] Growth factor-eluting cochlear implant electrode: impact on residual auditory function, insertional trauma, and fibrosis (2014)
  • Author(s): Kikkawa Y. S., Nakagawa T., Ying L., Tabata Y., Tsubouchi H., Ido A., and Ito J.
  • Journal Title: J Transl Med Volume: 12 Issue: 1 Pages: 280-280
  • DOI: 10.1186/s12967-014-0280-4
  • Peer Reviewed / Open Access / Acknowledgement Compliant
• [Journal Article] Favorable prognostic factors for long-term postoperative hearing results after canal tympanoplasty for congenital aural stenosis (2014)
  • Author(s): Sakamoto T, Kikkawa YS, Kikuta S, Kinoshita M, Ueha R, Suzukawa K, Kashio A, Kakigi A, Ito K, Suzuki M, Yamasoba T
  • Journal Title: Otology & Neurotology Volume: 35 Issue: 6 Pages: 966-71
  • DOI: 10.1097/mao.0000000000000335
  • Peer Reviewed