NMF308^(nmf/nmf)小鼠耳蜗毛细胞凋亡方式及z-VAD-FMK对毛细胞的保护作用  

Roles of Caspase Inhibitors in Cochlear Hair Cells Survival and Preventing Age-Related Hearing Loss

作　　者：李胜利[1,2,3] 王玉虎[1] 张敏燕 李白芽 郑庆印 朱雯瑾[2] 朱宏亮[2] 

机构地区：[1]西安交通大学第二附属医院科研中心实验室药剂科,西安710004 [2]西安交通大学医学院神经科学研究中心 [3]Case Western Reserve University School of Medicine,Department of Otolaryngology Head & Neck Surgery.Cleveland USA

出　　处：《听力学及言语疾病杂志》2015年第1期50-56,共7页Journal of Audiology and Speech Pathology

基　　金：国家自然科学基金对外交流与合作项目(30210103151);国家自然科学基金项目(81170922);美国NIH项目(R01DC007392)联合资助

摘　　要：目的了解年龄相关性听力损失小鼠耳蜗毛细胞的凋亡方式,探讨半胱氨酸蛋白酶(caspase)抑制剂z-VAD-FMK[z-Val-Ala-Asp(Ome)-fluoromethylketone]防治老年性聋的效果。方法选用新生NMF308nmf/nmf小鼠14只和成年同窝NMF308nmf/nmf小鼠32只,分为新生小鼠腹腔注射组(14只)、成年小鼠腹腔注射组(14只)和成年小鼠圆窗膜注射组(18只),各组又分为治疗组(注射z-VAD-FMK)和对照组[注射二甲基亚枫(dimethylsulfoxide,DMSO)],采用圆窗膜局部和腹腔注射两种方法给药,给药前后行ABR检测,用免疫荧光染色化学技术TUNEL、caspase-3和PI(碘化丙啶)染色标记耳蜗毛细胞,观察各组耳蜗毛细胞的凋亡和存活状况。结果NMF308nmf/nmf小鼠从1月龄开始发生听力减退和毛细胞功能改变,到2月龄时,caspase-3激活表达的毛细胞凋亡现象是毛细胞凋亡出现的最早表现;TUNEL阳性标记特征稍晚出现;PI标记可见毛细胞细胞核固缩和碎片出现的时间从2月龄开始;到3月龄时该种小鼠听力基本丧失,耳蜗毛细胞严重缺失;而应用z-VAD-FMK治疗后,各治疗组小鼠ABR反应阈明显好于对照组;耳蜗毛细胞凋亡数目较对照组减少,存活数明显较对照组多,尤以圆窗膜注射组明显。结论 NMF308nmf/nmf小鼠耳蜗毛细胞的死亡方式以caspase-3凋亡途径为主,应用caspase-3抑制剂zVAD-FMK定向内耳给药,可以阻断caspase-3信号途径激活所导致的毛细胞凋亡,从而有效防治老年性聋。Objective In this study ,we investigated the apoptosis of hair cell in the cochlea of age -related hearing loss（AHL） generated by ENU mutagenesis ,and to study a pan caspase inhibitor （z-VAD -FMK） which is to protect the cochlea hair cells from hearing loss induced by age-related hearing loss（AHL） .Methods Through z-VAD-FMK intraperitoneal injection and round window membrane （RWM） drug were delivered into the Cdh23 nmf308 nmf/nmf mice 5（postnatal days 2 -32） inner ear .ResuIts The results showed that the nmf308 mice with progressive hair cell loss along a base to apex gradient with age-related hearing loss .The cochlear OHCs reduced from 5% ～10% at 1 month to 100% at 3 month in the basal region .Substantial amounts of TUNEL -positive OHCs nuclei appeared at 1 month age ,and activated caspase-3 labeling demonstrated that most OHCs appeared at 2 months age .These suggested that DNA single strand break was attributed primarily to apoptosis of cochlear le_sions ,whereas in the later stage of lesion ,the expansion led to activation of caspase-3 activity reduced with further progression of nuclear condensation in age-related hearing loss .ConcIusion The addition of a pan caspase inhibitor （z -VAD -FMK ） significantly protected the cochlea against the hair cell loss induced by apoptosis .Our study showed that aspase inhibitor ,Z-VAD-FMK appeared to play a prominent role in age-related hearing loss media_ted hair cell death loss induced by apoptosis .Our study showed that aspase inhibitor ,Z-VAD -FMK appeared to play a prominent role in age-related hearing loss mediated hair cell death .

关 键 词：老年性聋 外毛细胞 凋亡 抗凋亡抑制剂 动物模型 

分 类 号：R764.436[医药卫生—耳鼻咽喉科]