Wang Ping, Li Haonan, Yu Shuyuan, Jin Peng, Hassan Abdurahman, Du Bo
Department of Otolaryngology-Head and Neck Surgery, First Hospital of Jilin University, #71 Xinmin Street, Changchun 130021,China.
Department of Otolaryngology-Head and Neck Surgery, First Hospital of Jilin University, #71 Xinmin Street, Changchun 130021,China.
Neurosci Lett. 2017 Aug 24;656:83-88. doi: 10.1016/j.neulet.2017.07.028. Epub 2017 Jul 19.
This study aimed to elucidate the protective effect of minocycline against streptomycin-induced damage of cochlear hair cells and its mechanism. Cochlear membranes were isolated from newborn Wistar rats and randomly divided into control, 500μmol/L streptomycin, 100μmol/L minocycline, and streptomycin and minocycline treatment groups. Hair cell survival was analyzed by detecting the expression of 3-nitrotyrosine (3-NT) in cochlear hair cells by immunofluorescence and an enzyme-linked immunosorbent assay. Expression of 3-NT and inducible nitric oxide synthase (iNOS), and poly (ADP-Ribose) polymerase (PARP) and caspase-3 activation were evaluated by western blotting. The results demonstrated hair cell loss at 24h after streptomycin treatment. No change was found in supporting cells of the cochleae. Minocycline pretreatment improved hair cell survival and significantly reduced the expression of iNOS and 3-NT in cochlear tissues compared with the streptomycin treatment group. PARP and caspase-3 activation was increased in the streptomycin treatment group compared with the control group, and pretreatment with minocycline decreased cleaved PARP and activated caspase-3 expression. Minocycline protected cochlear hair cells from injury caused by streptomycin in vitro. The mechanism underlying the protective effect may be associated with the inhibition of excessive formation of nitric oxide, reduction of the nitration stress reaction, and inhibition of PARP and caspase-3 activation in cochlear hair cells. Combined minocycline therapy can be applied to patients requiring streptomycin treatment.
本研究旨在阐明米诺环素对链霉素诱导的耳蜗毛细胞损伤的保护作用及其机制。从新生Wistar大鼠分离出耳蜗膜，随机分为对照组、500μmol/L链霉素组、100μmol/L米诺环素组以及链霉素与米诺环素联合治疗组。通过免疫荧光和酶联免疫吸附测定法检测耳蜗毛细胞中3-硝基酪氨酸（3-NT）的表达，分析毛细胞存活率。通过蛋白质印迹法评估3-NT和诱导型一氧化氮合酶（iNOS）的表达，以及聚（ADP-核糖）聚合酶（PARP）和半胱天冬酶-3的激活情况。结果显示，链霉素处理24小时后出现毛细胞丢失。耳蜗的支持细胞未发现变化。与链霉素治疗组相比，米诺环素预处理提高了毛细胞存活率，并显著降低了耳蜗组织中iNOS和3-NT的表达。与对照组相比，链霉素治疗组中PARP和半胱天冬酶-3的激活增加，米诺环素预处理降低了裂解的PARP和激活的半胱天冬酶-3的表达。米诺环素在体外保护耳蜗毛细胞免受链霉素引起的损伤。其保护作用的潜在机制可能与抑制一氧化氮的过度生成、减轻硝化应激反应以及抑制耳蜗毛细胞中PARP和半胱天冬酶-3的激活有关。米诺环素联合疗法可应用于需要链霉素治疗的患者。
