Elucidation of the pathophysiology of EYA4 gene mutation hearing loss using patient-derived iPS cells

2021 Fiscal Year Final Research Report

• Project/Area Number: 19K18816
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 56050:Otorhinolaryngology-related
• Research Institution: Keio University
• Principal Investigator: Saeko Matsuzaki 慶應義塾大学, 医学部(信濃町), 共同研究員 (70573400)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Keywords: EYA4遺伝子 / 遺伝性難聴 / 常染色体優性遺伝 / 進行性感音難聴

Outline of Final Research Achievements

We derived iPS cells from blood samples of 4 cases of EYA4 gene mutation patients and healthy subjects and induced into inner ear cells. The differences of EYA4 protein expression in each case were examined. EYA4 protein expression was observed at a high rate in the cytoplasm of patient-derived inner ear cells, and EYA4 expression in the nucleus also tended to be stronger than that of healthy human-derived inner ear cells. This tendency became stronger as the degree of deafness in the actual patient was heavier. In addition, various stress substances were added to the culture supernatant of inner ear cells to give cell stress, and the survival rate of the cells was examined, and the vulnerability to oxidative stress was particularly confirmed.

Free Research Field

耳鼻咽喉科学

Academic Significance and Societal Importance of the Research Achievements

EYA4遺伝子変異患者4症例および健常者の血液検体から誘導した内耳細胞を比較検討することで、内耳細胞内のEYA4タンパクの発現型に差異があること、またEYA4遺伝子変異難聴（DFNA10）では酸化ストレスの脆弱性が見られることなどが解明された。生体から内耳細胞を採取することは難しいが、疾患特異的iPS細胞研究という手法を用いることで、直接的に検討することが可能となった。今回の研究により、再生医療以外のiPS細胞の活用方法を示すことができた。また、本疾患に酸化ストレスの脆弱性が見られたことから、本疾患の治療薬開発の可能性がある。