自噬对噪声性耳聋急性损伤期毛细胞凋亡的作用机制研究  

Mechanism of autophagy on the apoptosis of hair cells during acute damage of noise deafness

作　　者：李林[1] 于佳雪 黄宏明[2] 崔勇[2] 盛晓丽[2] LI Lin;YU Jiaxue;HUANG Hongming;CUI Yong;SHENG XiaoLi(Department of Otolaryngology Head and Neck Surgery,Zhuhai Hospital of Guangdong Provincial People′ Hospital / Zhuhai Golden Bay Central Hospital,Zhuhai,Guangdong 519040,China;Department of Otorhinolaryngology,Guangdong Academy of Medicine Sciences/Guangdong General Hospital,Guangzhou,Guangdong 510080,China)

机构地区：[1]广东省人民医院珠海医院/广东省珠海市金湾中心医院耳鼻喉头颈外科,519040 [2]广东省医学科学院/广东省人民医院耳鼻咽喉头颈外科,510080

出　　处：《重庆医学》2022年第7期1112-1116,共5页Chongqing medicine

基　　金：广东省医学科研基金项目(B2019095)。

摘　　要：目的探讨自噬在噪声性耳聋防治中的作用及机制。方法建立大鼠噪声性耳聋模型。随机分为3个组:对照组(每次2 mL生理盐水);自噬激动剂雷帕霉素(RAP)组(每次7.5 mg/kg);自噬抑制剂3-甲基嘌呤(3MA)组(每次30 mg/kg 3MA),以上各组均于噪声暴露前24、暴露前2 h和暴露后即刻进行腹腔注射。听觉脑干反应(ABR)阈值检测评估大鼠ABR情况。应用双重免疫荧光染色检测氧化应激(OS)标记物3-硝基酪氨酸(3-NT)阳性表达细胞。Western blot检测自噬标记LC3-Ⅱ/LC3-Ⅰ和Beclin-1表达水平。使用TUNEL法检测细胞凋亡。结果噪声暴露后小鼠ABR阈值较暴露前升高。RAP组在噪声暴露后1、12、24 h各时间点的ABR阈值较对照组均明显增加;而3MA组在以上各时间点的ABR阈值较对照组则明显减少(均P<0.05);噪声暴露后各耳蜗毛细胞自噬标记蛋白表达水平较暴露前明显升高。RAP组噪声暴露1、12、24 h耳蜗毛细胞自噬标记蛋白表达水平明显高于对照组,而3MA组以上各时间点耳蜗毛细胞自噬标记蛋白表达水平则明显低于对照组(均P<0.05);噪声暴露后各组耳蜗毛细胞3-NT水平明显较暴露前增高,RAP组暴露1、12、24 h 3-NT水平较对照组增加;而3MA组以上各时间点3-NT水平较对照组减少(均P<0.05);噪声暴露后各组耳蜗毛细胞凋亡较暴露前明显增加,RAP组耳蜗毛细胞凋亡较对照组增加,而3MA组耳蜗毛细胞凋亡较对照组减少(均P<0.05)。结论在噪声性耳聋损伤的急性期,自噬表达明显上调,并通过OS途径诱导毛细胞凋亡;抑制自噬能够明显改善毛细胞程序性凋亡的发生,进而改善听力。Objective To investigate the role and mechanism of autophagy in the prevention and treatment of noise-induced deafness.Methods The rat model of noise-induced deafness was established.The rats were randomly divided into three groups:the control group(2 mL saline daily);the autophagy agonist rapamycin(RAP)group(7.5 mg/kg daily);the autophagy inhibitor 3 methylpurine(3MA)group(30 mg/kg daily).Auditory brainstem response(ABR)threshold assay was used to assess the auditory threshold shift in rats.Double immunofluorescence staining was applied to detect positive cells for the reactive oxygen species(ROS)marker 3-nitrotyrosine(3-NT).Western blot was used to detect the expression levels of autophagy marker proteins LC3-II/LC3-I and Beclin-1.Apoptosis was detected by using the TUNEL method.Results The ABR threshold was higher after noise exposure than before exposure.Compared with the control group,the ABR thresholds of the RAP group at the time point of 1,12,and 24 h after noise exposure were significantly increased;while the ABR thresholds of the 3MA group at the above time points were significantly lower than those of the control group(all P<0.05).The expression levels of autophagy marker proteins in cochlear hair cells after exposure were significantly higher than those before exposure.The expression levels of autophagy marker proteins in cochlear hair cells in the RAP group were significantly higher than those in the control group after 1,12,and 24 h of noise exposure,while the expression levels of autophagy marker proteins in cochlear hair cells in the 3MA group at the time points above were significantly lower than those in the control group(all P<0.05).The level of 3-NT in cochlear hair cells after noise exposure was significantly higher than that before exposure.The level of 3-NT in cochlear hair cells in the RAP group was higher than that in the control group after noise exposure for 1,12,and 24 h,while the expression level of autophagy 3-NT in cochlear hair cells in the 3MA group at the time points above were s

关 键 词：自噬 噪声性耳聋 氧化应激 耳蜗 毛细胞 

分 类 号：R764.433[医药卫生—耳鼻咽喉科]