A new mouse mutant of the Cdh23 gene with early-onset hearing loss facilitates evaluation of otoprotection drugs

Original Article

The Pharmacogenomics Journal advance online publication 20 July 2010; doi: 10.1038/tpj.2010.60

F Han1,4, H Yu1,4, C Tian1, H E Chen1, C Benedict-Alderfer1, Y Zheng1, Q Wang1,5, X Han1 and Q Y Zheng1,2,3

1. Department of Otolaryngology-HNS, Case Western Reserve University, Cleveland, OH, USA
2. Department of Genetics, Case Western Reserve University, Cleveland, OH, USA
3. Case Comprehensive Cancer Center, Case Western Reserve University, Cleveland, OH, USA

Correspondence: Dr QY Zheng, Department of Otolaryngology-HNS, Case Western Reserve University, 11100 Euclid Avenue, LKS 5045, Cleveland, OH 44106, USA. E-mail: qing.zheng@case.edu

4These authors contributed equally to this work.

5Current address: Department of Otolaryngology and HNS, Chinese PLA Institute of Otolaryngology, Chinese PLA General Hospital, 28 Fuxing Road, Beijing 100853 China.

Received 4 November 2009; Revised 4 June 2010; Accepted 14 June 2010; Published online 20 July 2010.
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Abstract

We report a novel mutation (erlong, erl) of the cadherin 23 (Cdh23) gene in a mouse model for DFNB12 characterized by progressive hearing loss beginning from postnatal day 27 (P27). Genetic and sequencing analysis revealed a 208 T >C transition causing an amino-acid substitution (70S–P). Caspase expression was upregulated in mutant inner ears. Hearing was preserved (up to 35-dB improvement) in pan-caspase inhibitor Z-VAD-FMK-treated mutants compared with untreated mutants (P<0.05). Outer hair cell (OHC) loss in the cochleae of Z-VAD-FMK-treated mutants was significantly reduced compared with those of untreated mice. Thus, the erl mutation can lead to hearing loss through apoptosis. This is the first genetic mouse model of hearing loss shown to respond to otoprotective drug therapy. The short interval from initial hearing loss to deafness (P27–P90) makes this model ideal for screening and validating otoprotective drugs.