Table_1_Cell-Specific Transcriptome Analysis Shows That Adult Pillar and Deiters' Cells Express Genes Encoding Machinery for Specializations of Cochlear Hair Cells.XLSX

The mammalian auditory sensory epithelium, the organ of Corti, is composed of hair cells and supporting cells. Hair cells contain specializations in the apical, basolateral and synaptic membranes. These specializations mediate mechanotransduction, electrical and mechanical activities and synaptic transmission. Supporting cells maintain homeostasis of the ionic and chemical environment of the cochlea and contribute to the stiffness of the cochlear partition. While spontaneous proliferation and transdifferentiation of supporting cells are the source of the regenerative response to replace lost hair cells in lower vertebrates, supporting cells in adult mammals no longer retain that capability. An important first step to revealing the basic biological properties of supporting cells is to characterize their cell-type specific transcriptomes. Using RNA-seq, we examined the transcriptomes of 1,000 pillar and 1,000 Deiters' cells, as well as the two types of hair cells, individually collected from adult CBA/J mouse cochleae using a suction pipette technique. Our goal was to determine whether pillar and Deiters' cells, the commonly targeted cells for hair cell replacement, express the genes known for encoding machinery for hair cell specializations in the apical, basolateral, and synaptic membranes. We showed that both pillar and Deiters' cells express these genes, with pillar cells being more similar to hair cells than Deiters' cells. The fact that adult pillar and Deiters' cells express the genes cognate to hair cell specializations provides a strong molecular basis for targeting these cells for mammalian hair cell replacement after hair cells are lost due to damage.

哺乳动物听觉感觉上皮即耳蜗器（organ of Corti）由毛细胞与支持细胞组成。毛细胞的顶膜、基底侧膜及突触膜存在特化结构，这些特化结构介导机械转导、电活动、机械活动与突触传递。支持细胞可维持耳蜗内离子与化学环境的稳态，并参与耳蜗分区的刚度维持。在低等脊椎动物中，支持细胞的自发增殖与转分化是替代丢失毛细胞的再生反应来源，但成年哺乳动物的支持细胞已不再保留该能力。解析支持细胞的细胞类型特异性转录组，是揭示其基本生物学特性的重要首要步骤。本研究借助吸液管技术，从成年CBA/J小鼠耳蜗中分别收集1000个柱细胞（pillar cells）、1000个Deiters细胞（Deiters' cells）以及两种毛细胞，通过RNA-seq对其转录组进行检测。本研究的目标在于明确作为毛细胞替换常见靶标的柱细胞与Deiters细胞，是否表达编码毛细胞顶膜、基底侧膜及突触膜特化结构相关蛋白的基因。研究结果显示，柱细胞与Deiters细胞均表达上述基因，且柱细胞相较于Deiters细胞与毛细胞的相似性更高。成年柱细胞与Deiters细胞表达与毛细胞特化结构相关的同源基因，这一发现为毛细胞因损伤丢失后，针对上述细胞开展哺乳动物毛细胞替换治疗提供了坚实的分子基础。