哺乳动物耳蜗Kölliker器的形态学及退化机制研究

Morphology and degeneration mechanism of Kölliker's organ in mammalian cochlea

目的探索哺乳动物耳蜗Kölliker器退化过程中是否存在自噬现象。方法以P1~P14的SD大鼠耳蜗为研究对象,运用HE染色和透射电镜观察Kölliker器在耳蜗早期发育过程中的显微和亚显微形态学改变,并利用免疫组化、Western blot分子生物学实验观察自噬标记物LC3、Beclin1、P62在早期发育过程中的动态变化。结果利用HE染色及透射电镜大鼠耳蜗Kölliker器支持细胞的形态从底回向顶回逐渐由假复层柱状上皮转变为单层立方上皮,细胞层数和数量逐渐减少,最终形成成熟的内沟区域,并观察到自噬小体。免疫组化耳蜗Kölliker器支持细胞LC3-II、Beclin1、P62呈阳性。Western blot观察到P3~P10自噬相关蛋白呈逐渐下降的趋势。结论哺乳动物耳蜗Kölliker器退化过程中存在时间依赖性的自噬现象。

Objective To investigate whether autophagy exists in the degeneration of Kölliker's organ in the mammalian cochlea.Methods The cochlea of P1,P3,P5,P7,P10 and P14 SD rats were used as the research objects.HE staining and transmission electron microscopy were used to observe the microscopic and submicroscopic morphological changes of Kölliker's organ during the early development of cochlea.Immunohistochemistry and Western blot were used to observe the dynamic changes of autophagy markers LC3,Beclin1 and p62 during the early development.Results Though HE staining and transmission electron microscopy,the shape of Kölliker's organ supporting cells in the rat cochlea gradually changed from basal turn to apical turn,from pseudostratified columnar epithelium to monolayer cuboidal epithelium,the number of cell and cell layers gradually decreased,and finally formed mature inner sulcus area,and autophagosome were also observed.LC3-II,Beclin1,p62 were positive in the Kölliker's organ supporting cells of the cochlea.Western blot showed that p3-p10 autophagy related protein decreased gradually.Conclusion There exits a time-dependent autophagy in the degeneration of Kölliker's organ in mammalian cochlea.