2009 Fiscal Year Final Research Report
Disturbances of the stria vascularis in mice with genetic abnormalities
| Project/Area Number |
19591963
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Otorhinolaryngology
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| Research Institution | Nagoya University |
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Principal Investigator |
SONE Michihiko Nagoya University, 大学院・医学系研究科, 准教授 (30273238)
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| Co-Investigator(Kenkyū-buntansha) |
NAKASHIMA Tsutomu 名古屋大学, 大学院・医学系研究科, 教授 (30180277)
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| Project Period (FY) |
2007 – 2009
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| Keywords | 蝸牛 / 血管条 / 内耳障害 / 難聴 / メラニン |
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| Research Abstract |
Our findings are the first quantitative evidence to show an age-related overexpression of cochlear melanin and an alteration in the proportion of eumelanin and pheomelanin with aging, suggesting a possible otoprotective function of eumelanin against age-related cochlear deterioration. We focused on the roles of midkine and pleiotrophin in the stria vascularis using mice deficient in these genes. Hearing thresholds examined by auditory brain stem response were significantly higher in midkine knockout and pleiotrophin knockout mice than in wild-type mice. Double knockout mice showed higher thresholds compared to midkine knockout and pleiotrophin knockout mice. The expression of Kir4.1 was weak in the knockout mice and severe vacuolar degeneration was observed by electron microscopy in the intermediate cells of the double knockout mice. The present study demonstrates that midkine and pleiotrophin are essential components for the morphological maintenance of intermediate cell in the stria vascularis.
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