PDF(Pubmed)
Abstract：
Tmc1 and Tmc2 are essential pore-forming subunits of mechanosensory transduction channels localized to the tips of stereovilli in auditory and vestibular hair cells of the inner ear. To investigate expression and function of Tmc1 and Tmc2 in vestibular organs, we used quantitative polymerase chain reaction (qPCR), fluorescence in situ hybridization - hairpin chain reaction (FISH-HCR), immunostaining, FM1-43 uptake and we measured vestibular evoked potentials (VsEPs) and vestibular ocular reflexes (VORs). We found that Tmc1 and Tmc2 showed dynamic developmental changes, differences in regional expression patterns, and overall expression levels which differed between the utricle and saccule. These underlying changes contributed to unanticipated phenotypic loss of VsEPs and VORs in Tmc1 KO mice. In contrast, Tmc2 KO mice retained VsEPs despite the loss of the calcium buffering protein calretinin, a characteristic biomarker of mature striolar calyx-only afferents. Lastly, we found that neonatal Tmc1 gene replacement therapy is sufficient to restore VsEP in Tmc1 KO mice for up to six months post-injection.
摘要：
Tmc1和Tmc2是位于内耳听觉和前庭毛细胞中立体绒毛尖端的机械感觉传导通道的重要孔形成亚基。探讨Tmc1和Tmc2在前庭器官中的表达及功能,我们使用定量聚合酶链反应（qPCR），荧光原位杂交-发夹链反应（FISH-HCR），免疫染色，FM1-43摄取，我们测量了前庭诱发电位（VsEP）和前庭眼反射（VORs）。我们发现Tmc1和Tmc2表现出动态的发育变化，区域表达模式的差异，和整体表达水平在囊和囊之间不同。这些潜在的变化导致了Tmc1KO小鼠中VsEP和VOR的意外表型丧失。相比之下,Tmc2KO小鼠保留了VsEP，尽管钙缓冲蛋白钙的损失，成熟的纹状体花萼传入的特征性生物标志物。最后,我们发现,新生儿Tmc1基因替代疗法足以在注射后6个月内恢复Tmc1KO小鼠的VsEP.
