Heterozygous mutation of Ush1g/Sans in mice causes early-onset progressive hearing loss, which is recovered by reconstituting the strain-specific mutation in Cdh23
Heterozygous mutation of Ush1g/Sans in mice causes early-onset progressive hearing loss, which is recovered by reconstituting the strain-specific mutation in Cdh23
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DOI：
10.1093/hmg/ddw078
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发表时间：
2016-05-15
影响因子：
3.5
通讯作者：
Kikkawa, Yoshiaki
中科院分区：
文献类型：
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作者：
Miyasaka, Yuki;Shitara, Hiroshi;Kikkawa, Yoshiaki
大多数临床报告表明，先天性极重度听力损失患者存在耳聋基因的隐性突变，而显性等位基因与进行性听力损失（PHL）相关。杰克逊摇床（Ush 1g（js））是隐性耳聋的小鼠模型，其表现出由11号染色体上的Ush 1g/Sans纯合突变引起的先天性深度耳聋。我们发现C57 BL/6 J-Ush 1g（js/+）杂合子小鼠表现出早发性PHL（ePHL），并伴有耳蜗外毛细胞静纤毛的进行性变性。有趣的是，ePHL在具有C3 H/HeN背景的突变小鼠中没有发展，因此表明ePHL发展需要其他遗传因素。因此，我们进行了经典的遗传分析，发现Ush 1g（js/+）小鼠中ePHL的发生与10号染色体中含有钙粘蛋白23基因（Cdh 23）的间隔有关，该基因也是人类耳聋的原因。为了证实这种突变效应，我们通过使用CRISPR/Cas9介导的Cdh 23（c.753A> G）敲入方法产生了C57 BL/6 J-Ush 1g（js/+），Cdh 23（c.753A/G）双杂合小鼠。Cdh 23（c.753A/G）小鼠具有一个碱基替换（A替换为G），纯合A等位基因随年龄增长导致中度听力损失。分析显示C57 BL/6 J-Ush 1g（js/+）小鼠的ePHL和静纤毛变性完全恢复。这些结果清楚地表明，ePHL的发展需要Ush 1g和Cdh 23基因的至少两个突变等位基因。我们的研究结果还表明，由于SANS和CDH 23蛋白在静纤毛中形成复合物，这些蛋白之间的相互作用可能在静纤毛的维持和ePHL的预防中发挥关键作用。
Most clinical reports have suggested that patients with congenital profound hearing loss have recessive mutations in deafness genes, whereas dominant alleles are associated with progressive hearing loss (PHL). Jackson shaker (Ush1g(js)) is a mouse model of recessive deafness that exhibits congenital profound deafness caused by the homozygous mutation of Ush1g/Sans on chromosome 11. We found that C57BL/6J-Ush1g(js/+) heterozygous mice exhibited early-onset PHL (ePHL) accompanied by progressive degeneration of stereocilia in the cochlear outer hair cells. Interestingly, ePHL did not develop in mutant mice with the C3H/HeN background, thus suggesting that other genetic factors are required for ePHL development. Therefore, we performed classical genetic analyses and found that the occurrence of ePHL in Ush1g(js/+) mice was associated with an interval in chromosome 10 that contains the cadherin 23 gene (Cdh23), which is also responsible for human deafness. To confirm this mutation effect, we generated C57BL/6J-Ush1g(js/+), Cdh23(c.753A/G) double-heterozygous mice by using the CRISPR/Cas9-mediated Cdh23(c.753A > G) knock-in method. The Cdh23(c.753A/G) mice harbored a one-base substitution (A for G), and the homozygous A allele caused moderate hearing loss with aging. Analyses revealed the complete recovery of ePHL and stereocilia degeneration in C57BL/6J-Ush1g(js/+) mice. These results clearly show that the development of ePHL requires at least two mutant alleles of the Ush1g and Cdh23 genes. Our results also suggest that because the SANS and CDH23 proteins form a complex in the stereocilia, the interaction between these proteins may play key roles in the maintenance of stereocilia and the prevention of ePHL.