外毛细胞基底侧膜动力蛋白分布均一性的研究  

The Distribution of Prestin on the Whole Basolateral Surface of Outer Hair Cells

作　　者：于宁[1,2] 翟所强[1] 赵红波[2] 

机构地区：[1]解放军总医院耳鼻咽喉-头颈外科解放军耳鼻咽喉科研究所,北京100853 [2]美国肯塔基州立大学医学中心耳鼻咽喉科

出　　处：《听力学及言语疾病杂志》2009年第5期461-464,共4页Journal of Audiology and Speech Pathology

基　　金：国家自然科学基金(30600700;30772413);美国NIH项目NIDCD DC(05989)资助

摘　　要：目的探讨OHC基底部是否存在动力蛋白(Prestin)的表达及其在侧膜三层结构中的定位。方法分别取正常C57小鼠、Wistar大鼠及豚鼠耳蜗的单离外毛细胞,在激光共聚焦显微镜下,利用Prestin特异性抗体与细胞膜标记di-8-ANEPPS双染,对Prestin在单离OHC上的表达与分布情况进行观察。结果OHC基底侧膜存在Prestin抗体的阳性染色,OHC底端亦见阳性染色;②与细胞膜标记di-8-ANEPPS染色相比,Prestin抗体的阳性染色位于细胞膜的外侧;③经低渗细胞外液处理后,OHC侧膜中的质膜层可与内层表皮下池(subsur-fac cisternae,SSC)和中层质膜下小梁(cortical lattice,CL)分离,在激光共聚焦显微镜下,外毛细胞膜最外层的质膜层上可见明显的Prestin抗体阳性染色。结论动力蛋白(Prestin)分布于外毛细胞膜中最外层的质膜层上,在细胞基底部细胞膜上亦有表达。Objective The prestin ,a motor protein responsible for outer hair cell （OHC） electromotility, is expressed on the OHC surface. Previous experiments revealed that OHC electromotility and its associated nonlinear capacitance was mainly located at the OHC lateral wall and was absent at the apical cuticular plate and the basal nucleus pole. Immunofluorescent staining for prestin failed to demonstrate the prestin expression at the OHC basal ends in whole-mount preparation of the organ of Corti. The aim of this study is to investigate the distribution of prestin at OHC. Methods In this experiment, the localization of prestin protein in single dissociated OHCs from cochlea of normal mouse, rat and guinea pig, were examined by immunofluorescent staining and confocal microscopy. Results We found that prestin was uniformly expressed on the OHC basolateral surface, including its basal pole. No staining was observed on the cuticular plate and stereocilia. The OHC lateral wall had a trilaminate organization and was composed of the plasma membrane, cortical lattice, and subsurface cisternae. By with co-staining with a membrane marker di-8-ANEPPS, prestin-labeling was found locating at the outer layer of the OHC lateral wall. Further separating the plasma membrane from the underlying subsurface cisternae, using a hypotonic extracellular solution, prestin-labeling was shown locating at the plasma membrane instead of the subsurface cisternae. Conclusion The data revealed that prestin is expressed in the plasma membrane on the whole OHC basolateral surface.

关 键 词：耳蜗 主动放大机制 外毛细胞电运动 质膜 动力蛋白 

分 类 号：R339.16[医药卫生—人体生理学]