d-Galactose-induced oxidative stress and mitochondrial dysfunction in the cochlear basilar membrane: an in vitro aging model
d-Galactose-induced oxidative stress and mitochondrial dysfunction in the cochlear basilar membrane: an in vitro aging model
复制标题
d-半乳糖诱导的耳蜗基底膜氧化应激和线粒体功能障碍：体外衰老模型
DOI：
10.1007/s10522-020-09859-x
复制
发表时间：
2020-02-05
期刊：
影响因子：
4.5
通讯作者：
Gong, Shu-Sheng
中科院分区：
文献类型：
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作者：
Guo, Bin;Guo, Qing;Gong, Shu-Sheng
耳蜗基底膜（CBM）包含内毛细胞和外毛细胞，它们将声波转化为电信号并将其传输到中枢听觉系统。耳蜗老化是年龄相关性听力损失的主要原因，可降低信号传输能力。目前还没有理想的CBM体外老化模型。在这项研究中，我们培养的CBM，这是解剖从耳蜗的C57 BL/6小鼠出生后5天，在培养基中含有20 mg/mL，40 mg/mL，或60 mg/mL的d-半乳糖（d-gal）。与对照组相比，d-半乳糖组CBM中衰老相关β-半乳糖苷酶水平呈浓度依赖性升高。此外，线粒体超氧化物的水平和模式的年龄相关的线粒体DNA 3860-bp缺失显着增加。与对照组相比，D-半乳糖组的CBM中线粒体ATP水平和膜电位显著降低。此外，与对照组相比，d-gal组的CBM中观察到毛细胞静纤毛受损和内毛细胞带状突触丢失。在高剂量半乳糖组的CBM中也观察到毛细胞的损失和半胱天冬酶-3介导的外毛细胞凋亡的活化。D-半乳糖在离体耳蜗中引起的损伤与在体耳蜗自然老化中发生的损伤相似。因此，我们认为这是一个成功的体外老化模型，使用培养的CBM。这些结果表明线粒体氧化损伤在老年性耳聋中的作用，并提供了一个可靠的老化模型，在体外研究老年性耳聋的机制。
The cochlear basilar membrane (CBM) contains inner hair cells and outer hair cells that convert sound waves into electrical signals and transmit them to the central auditory system. Cochlear aging, the primary reason of age-related hearing loss, can reduce the signal transmission capacity. There is no ideal in vitro aging model of the CBM. In this study, we cultured the CBM, which was dissected from the cochlea of the C57BL/6 mice 5 days after birth, in a medium containing 20 mg/mL, 40 mg/mL, or 60 mg/mLd-galactose (d-gal). Compared with the control group, the levels of senescence-associated β-galactosidase were increased in a concentration-dependent manner in the CBM of thed-gal groups. In addition, levels of the mitochondrial superoxide and patterns of an age-related mitochondrial DNA3860-bp deletion were significantly increased. The ATP levels and the membrane potential of the mitochondrial were significantly decreased in the CBM of the D-gal groups compared with the control group. Furthermore, in comparison with the control group, damaged hair cell stereocilia and a loss of inner hair cell ribbon synapses were observed in the CBM of thed-gal groups. A loss of hair cells and activation of caspase-3-mediated outer hair cell apoptosis were also observed in the CBM of the high-dosed-gal group. These insults induced by D-gal in the CBM in vitro were similar to the ones that occur in cochlear natural aging in vivo. Thus, we believe that this is a successful in vitro aging model using cultured CBM. These results demonstrate the effects of mitochondrial oxidative damage on presbycusis and provide a reliable aging model to study the mechanisms of presbycusis in vitro.