Department of Otorhinolaryngology Head-and-Neck Surgery, Seoul National University College of Medicine, Seoul, Republic of Korea.
J Comp Neurol. 2013 May 1;521(7):1470-81. doi: 10.1002/cne.23197.
WD40 repeat protein 1 (WDR1) has been suggested as a protective mechanism or a sign of regeneration in avian cochlea. However, its role in mammalian cochlea has yet to be determined. Hence, we investigated WDR1 expression in sound-overstimulated Sprague-Dawley rats. Rats were divided into three groups (the permanent and temporary threshold shift [PTS and TTS] groups and the control group) according to the extent of noise exposure and euthanized immediately, 3, or 7 days after noise exposure for cochlear harvest. Immunocytochemistry localized WDR1 to outer hair cells, Deiter's cells, outer sulcus cells, and Reissner's membrane in the control group, and the PTS and TTS groups exhibited stronger WDR1 expression in the same cochlear regions than the controls. Moreover, WDR1 expression in these noise-exposed groups was extended to inner hair cells and basal cells of the stria vascularis. The expression of WDR1 in the PTS and TTS groups showed differences in intensity and shifts of localization, based on exposure length and recovery duration. Contrary to the avian cochlea, hair cell regeneration does not naturally occur in the acoustically damaged mammalian cochlea. Therefore, elevated WDR1 expression after acoustic overstimulation in the current experiments may provide a mechanism for protection against noise exposure.
WD40 重复蛋白 1（WDR1）被认为是禽类耳蜗中再生的保护机制或标志。然而，其在哺乳动物耳蜗中的作用尚未确定。因此，我们研究了 WDR1 在声音过度刺激的 Sprague-Dawley 大鼠中的表达。大鼠根据噪声暴露的程度分为三组（永久性和暂时性阈移[PTS 和 TTS]组和对照组），并在噪声暴露后立即、3 天或 7 天处死以收获耳蜗。免疫细胞化学将 WDR1 定位在外毛细胞、Deiter 细胞、外嵴细胞和 Reissner 膜中，在 PTS 和 TTS 组中，与对照组相比，相同耳蜗区域的 WDR1 表达更强。此外，WDR1 在这些噪声暴露组中的表达扩展到了内毛细胞和血管纹的基底细胞。基于暴露长度和恢复持续时间，PTS 和 TTS 组中 WDR1 的表达在强度和定位上存在差异。与禽类耳蜗不同，哺乳动物耳蜗中的毛细胞再生不会自然发生。因此，当前实验中在声过度刺激后 WDR1 表达的升高可能为对抗噪声暴露提供了一种保护机制。
