连接蛋白29在小鼠耳蜗中的表达

Expression of Connexin 29 in mice cochlea

目的研究连接蛋白29(connexin 29,Cx29)在小鼠内耳的表达,探讨Cx29突变致聋的原因。方法野生型小鼠耳蜗冰冻切片,用神经丝蛋白(neurofilament,NF)、髓鞘相关糖蛋白抗体(myelin associated glycoprotein,MAG)和神经胶质纤维酸性蛋白(glial fibrillary acidic protein,GFAP)抗体与Cx29抗体行双重免疫荧光染色,荧光显微镜观察染色结果。结果Cx29主要表达于位听神经和螺旋神经节细胞髓鞘,MAG与Cx29的共同表达于内耳位听神经处,表达呈圈状;GFAP只在内听道以外的脑干部位表达,与Cx29无共同表达;Cx29形成一个个圈样围绕NF;血管纹处可见Cx29微量表达。结论Cx29在小鼠内耳中大量表达,可能对维持小鼠正常听觉功能起重要作用。

Objective To investigate the expression of connexin29 （connexin 29, Cx29）in mice cochlea and explore the reason why mutation of Cx29 caused deafness. Methods Adult wild type mice C57 were decapitated and their cochleas were dissected. After a series of preparations, frozen cochlea sections were cut （7μm）. Immunofluorescent labeling protein and colabeling of Cx29 with neurofilament （NF）, myelin associated glycoprotein （MAG） and glial fibrillary acidic （GFAP） were applied to the sections. Labeled samples were observed by a fluorescent microscope. Results In low-magnification view, Cx29 strongly labeled tracts where the auditory nerve travels inside the cochlea until the border was marked by the glial junction. The stria vascularis was faintly stained. Views obtained at higher magnification showed Cx29 expressed at the myelin of the spiral ganglion neurons and the auditory nerve fibers inside cochleas. Colabeling im munostaining showed MAG expressed in the auditory nerve inside and outside the cochlea and co-expressed with Cx29 only in the auditory nerve inside the cochlea in circular immuno-staining patterns. GFAP was only expressed in the auditory nerve in the bminstem outside the cochlea. There were no co-expressions of GFAP and Cx29. The antibody against , neuro-filament gave an immuno-staining pattem of solid dots which were encircled by Cx29-positive pixels. Conclusion Cx29 strongly expresses in mice cochlea. It suggested that Cx29 should play an important role in the function of mice cochlea,