Prasad Sonal, Vona Barbara, Diñeiro Marta, Costales María, González-Aguado Rocío, Fontalba Ana, Diego-Pérez Clara, Subasioglu Asli, Bademci Guney, Tekin Mustafa, Cabanillas Rubén, Cadiñanos Juan, Fridberger Anders
Department of Biomedical and Clinical Sciences, Linköping University, SE-581 83, Linköping, Sweden.
Department of Otorhinolaryngology, Head and Neck Surgery, Tübingen Hearing Research Centre, Eberhard Karls University Tübingen, 72076, Tübingen, Germany.
Commun Biol. 2020 Dec 23;3(1):792. doi: 10.1038/s42003-020-01506-y.
The stereocilia of the inner ear sensory cells contain the actin-binding protein radixin, encoded by RDX. Radixin is important for hearing but remains functionally obscure. To determine how radixin influences hearing sensitivity, we used a custom rapid imaging technique to visualize stereocilia motion while measuring electrical potential amplitudes during acoustic stimulation. Radixin inhibition decreased sound-evoked electrical potentials. Other functional measures, including electrically induced sensory cell motility and sound-evoked stereocilia deflections, showed a minor amplitude increase. These unique functional alterations demonstrate radixin as necessary for conversion of sound into electrical signals at acoustic rates. We identified patients with RDX variants with normal hearing at birth who showed rapidly deteriorating hearing during the first months of life. This may be overlooked by newborn hearing screening and explained by multiple disturbances in postnatal sensory cells. We conclude radixin is necessary for ensuring normal conversion of sound to electrical signals in the inner ear.
内耳感觉细胞的静纤毛含有由RDX编码的肌动蛋白结合蛋白根蛋白。根蛋白对听力很重要，但其功能仍不清楚。为了确定根蛋白如何影响听力敏感性，我们使用了一种定制的快速成像技术来观察静纤毛的运动，同时测量声刺激期间的电位振幅。根蛋白抑制降低了声音诱发的电位。其他功能测量，包括电诱导的感觉细胞运动性和声诱发的静纤毛偏转，显示振幅略有增加。这些独特的功能改变表明根蛋白是将声音以声学速率转换为电信号所必需的。我们鉴定出了出生时听力正常但在生命的头几个月听力迅速恶化的RDX变体患者。这可能会被新生儿听力筛查忽略，并可由产后感觉细胞的多种干扰来解释。我们得出结论，根蛋白是确保内耳声音正常转换为电信号所必需的。
