年龄相关听力损失小鼠耳蜗和蜗核组织中MeCP2_BDNF的变化

Changes of MeCP2 and BDNF in the cochlea and cochlear nuclei of BALB/c mice with age-related hearing loss

目的:探讨年龄相关性听力损失小鼠听觉系统中甲基化Cp G结合蛋白2(MeCP2)和脑源性神经营养因子(BDNF)的表达随月龄增长的变化。方法:应用蛋白免疫印迹、荧光定量逆转录多聚酶链反应方法,分别检测3、6、12、18月龄鼠耳蜗和蜗核组织中MeCP2、BDNF的表达。结果:MeCP2、BDNF在4个不同月龄组小鼠耳蜗和蜗核组织中均有表达,随着月龄增加,MeCP2蛋白表达及BDNF m RNA表达水平呈一致性下降趋势,6、12、18月龄组均明显低于3月龄组,各组间比较差异有显著性。结论:年龄相关性听力损失与听觉系统中MeCP2及其相关基因BDNF的表达下调密切相关。

Objective To investigate the changes of methyl-Cp G-binding protein 2(MeCP2), and brain-derived neurotrophic factor(BDNF) expressions in the auditory system of BALB/c mice with age-related hearing loss. Methods The levels of MeCP2 protein in the cochlea and cochlear nuclei of BALB/c mice among four age groups(3-, 6-, 12-and 18-month-old) were detected and compared via Western blot assay. Detection and analysis of the expression of BDNF m RNA in the cochlea and cochlear nuclei were carried out by reverse transcription polymerase chain reaction(RT-PCR) on 3-, 6-, 12-and 18-month-old BALB/c mice, respectively. Results MeCP2 and BDNF were expressed in both cochlea and cochlear nuclei of BALB/c mice in four age groups. Western blot assay showed that the levels of MeCP2 protein in the cochlea and cochlear nuclei tissues of mice gradually decline with the increase of age. Results of RT-PCR demonstrated that the m RNA expression of BDNF decreased as the age increasing. The optical density(OD) ratio of MeCP2 and BDNF were significantly lower in 6-, 12-and 18-monthold mice than in 3-month-old mice, there was a statistically significant difference between each two groups. Conclusion The age-related hearing loss is close related to the consistent age-relatedly down-regulated expression of MeCP2 and its correlation genes BDNF in auditory system.