Activation of Wnt/β‐catenin signaling by lithium chloride attenuates d ‐galactose‐induced neurodegeneration in the auditory cortex of a rat model of aging

作者：Mingyu Xia, Xue‐Yan Zhao, Qilin Huang, Haiying Sun, Chen Sun, Jie Yuan, Chang He, Yu Sun, Xiang Huang, Wen Kong, Weijia Kong · 发表于：FEBS Open Bio · 年份：2017 · DOI：10.1002/2211-5463.12220 · 被引用次数：78 · 研究领域：Biochemical effects in animals、Antioxidants, Aging, Portulaca oleracea、Neurogenesis and neuroplasticity mechanisms

Degeneration of the central auditory system, which is characterized by reduced understanding of speech and source localization of sounds, is an important cause of age‐related hearing loss (presbycusis). Accumulating evidence has demonstrated that Wnt/β‐catenin signaling plays an essential role in the development of the auditory system but its potential role in presbycusis remains unclear. In this study, we used a rat model of aging, created by chronic systemic exposure to d‐galactose (d‐gal), and explored changes in Wnt/β‐catenin signaling in the auditory cortex. A decrease in Wnt/β‐catenin signaling in the auditory cortex was found in both naturally aging and d‐gal‐mimetic aging rats, as indicated by increased GSK3β activity and decreased β‐catenin activity. Moreover, lithium chloride (Licl), an activator of Wnt signaling pathway, was administered long term to 15‐month‐old d‐gal‐treated rats. Activation of Wnt/β‐catenin signaling by Licl attenuated d‐gal‐induced auditory cortex apoptosis and neurodegeneration. Bmi1, a transcription factor implicated in antiaging and resistance to apoptosis, can be modulated by β‐catenin activity. Here, we showed that the expression of Bmi1 was reduced and the expression of its downstream genes, p16INK4a, p19Arf, and p53 were increased in the auditory cortex both of naturally aging and d‐gal‐mimetic aging rats. In addition, Licl significantly increased Bmi1 expression and reduced p16INK4a, p19Arf, and p53 expression. Our results indicated tha...