Qin Tianli, Bronner Marianne E
Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, 91125, USA.
Dev Biol. 2025 Aug;524:97-104. doi: 10.1016/j.ydbio.2025.05.007. Epub 2025 May 9.
The inner ear is an intricate structure that houses six sensory organs responsible for both hearing and balance. The development of the inner ear begins with the formation of the otic placode, a transient ectodermal thickening that emerges early during embryonic development. The otic placode undergoes a series of morphological changes, from thickening to invagination and then pinching off from the ectoderm to form the otic vesicle, which further differentiates into the specialized structures of the inner ear. These developmental processes require a coordinated interplay between intrinsic transcription factors and extrinsic signaling molecules, which regulate the patterning, proliferation, and differentiation of the inner ear components. In this review, we focus on the role of Sonic hedgehog (Shh) signaling in the development of the mammalian inner ear. We explore how Shh signaling is involved at multiple stages of inner ear development, including the patterning of the otic vesicle and the differentiation of specific cell types within the cochlea. Additionally, we discuss the mechanisms by which Shh signaling integrates with other signaling pathways and transcription factors to ensure the proper development and function of the inner ear. Understanding the molecular basis of these processes provides valuable insights into inner ear development and its disorders.
内耳是一个复杂的结构，包含六个负责听觉和平衡的感觉器官。内耳的发育始于耳基板的形成，耳基板是胚胎发育早期出现的一种短暂的外胚层增厚。耳基板经历一系列形态变化，从增厚到内陷，然后从外胚层分离形成耳泡，耳泡进一步分化为内耳的特殊结构。这些发育过程需要内在转录因子和外在信号分子之间的协同相互作用，它们调节内耳各组成部分的模式形成、增殖和分化。在这篇综述中，我们重点关注音猬因子（Shh）信号通路在哺乳动物内耳发育中的作用。我们探讨Shh信号通路如何参与内耳发育的多个阶段，包括耳泡的模式形成以及耳蜗内特定细胞类型的分化。此外，我们讨论Shh信号通路与其他信号通路和转录因子整合以确保内耳正常发育和功能的机制。了解这些过程的分子基础为内耳发育及其疾病提供了有价值的见解。
