CAJ | 학술논문

目的观察年龄相关性听力损失小鼠耳蜗毛细胞的死亡方式,探讨老年性聋的分子机制.方法随机选用5～7只28、30和60天龄的NMF308~(nmf/nmf)小鼠,应用ABR和DPOAE检测听功能,用免疫荧光染色组织化学技术TUNEL,Caspase-3和碘化丙啶(PI)染色标记并观察耳蜗毛细胞.结果 NMF308~(nmf/nmf)小鼠从1月龄开始发生听功能减退和毛细胞改变,到2月龄时出现明显的TUNEL阳性标记,是毛细胞凋亡的最早表现;Caspase -3阳性表达的毛细胞凋亡现象稍晚出现;PI标记可见2～3月龄开始出现毛细胞细胞核固缩和碎片;到3月龄时听功能基本丧失,耳蜗毛细胞严重缺失.结论老年性聋的早期首先出现耳蜗毛细胞出现DNA单链断裂,随后Caspase-3信号途径激活,导致耳蜗毛细胞凋亡.
목적 관찰년령상관성은력손실소서이와모세포적사망방식,탐토노년성롱적분자궤제.방법 수궤선용5～7지28、30화60천령적NMF308~(nmf/nmf)소서,응용ABR화DPOAE검측은공능,용면역형광염색조직화학기술TUNEL,Caspase-3화전화병정(PI)염색표기병관찰이와모세포.결과 NMF308~(nmf/nmf)소서종1월령개시발생은공능감퇴화모세포개변,도2월령시출현명현적TUNEL양성표기,시모세포조망적최조표현;Caspase -3양성표체적모세포조망현상초만출현;PI표기가견2～3월령개시출현모세포세포핵고축화쇄편;도3월령시은공능기본상실,이와모세포엄중결실.결론 노년성롱적조기수선출현이와모세포출현DNA단련단렬,수후Caspase-3신호도경격활,도치이와모세포조망.
Objective In this study,we investigated the hair cell apoptosis and the molecular mechanisms in age-related hearing IOSS mouse cochlea.Methods All animals were assessed by ABR and DPOAE analysis in both ears.TUNEL(Terminal dexynucleotidyl transferase(TdT)mediated dUTP Nick End Labeling)and PI were used to identify DNA fiagments and caspase-3 activities in hair cells.Results The results showed that the nmf308 mice had progressive hair cell loss along with age.The cochlear OHCs were reduced 5%～10% at 1 month and 100% at 3 month in the basal region.Substantial amounts of TUNEL-postive OHCs nuclei were observed at age of 1 month,and activated caspase-3 labeling OHCs were most obviously observed at age of 2 months.Conclusion These results suggest that DNA single strand break is attributed primarily to apoptosis of cochlear lesion,and activation of caspase-3 at leter stage leads to the hair cell apoptiovs of nuclear condensation in age-related hearing loss mouse cochlea.