内耳毛细胞静纤毛高度调控分子机制

The underlying mechanism of stereocilia height regulation in inner ear hair cells

内耳毛细胞(hair cell)是动物感知听觉和平衡信息的感受器细胞,负责将机械能信号转换为电信号(即机械-电转换,简称为MET),因位于其上表面的细胞突起——纤毛束(hair bundle)而得名。每个毛细胞的纤毛束包括一根以微管蛋白为骨架的动纤毛(kinocilium)和多根以肌动蛋白为骨架的静纤毛(stereocilia)。动纤毛在纤毛束的发育过程中发挥重要作用,而静纤毛对于机械-电转换必不可少。每个毛细胞中的静纤毛组织成多排高度不同的阶梯状结构,其发育和维持受到严格调控。近年来,随着蛋白质组学、转录组学、超高分辨显微镜等技术的发展,人们对静纤毛高度调控分子机制的认识越来越深入,但仍有很多问题亟待回答。文章对目前已知的静纤毛高度调控的分子机制进行简要介绍。

Inner ear hair cells are the receptor cells for sound and balance sensation in animals, responsible for transducing mechanical signals into electrical signals, a process referred to as mechanoelectrical transduction(MET). Hair cell is named after the hair bundle on its apical surface, which consists of one tubulin-based kinocilium and dozens of actin-based stereocilia. Kinocilium plays an important role in the development of hair bundle, while stereocilia are indispensable for MET. In each hair cell, the stereocilia are organized into several rows of increasing heights, forming a staircase-like pattern. The development and maintenance of stereocilia is tightly regulated. In recent years, the rapid progress in proteomics, transcriptomics, and super-resolution microscopy has shed lights on the underlying mechanism of stereocilia height regulation, but a lot more awaits further investigations. In the present review, we focus on what is known about the mechanism of stereocilia height regulation.