不同月龄小鼠蜗神经核中甲基化CpG结合蛋白2的表达及临床意义

Expression of the methyl-CpG-binding protein 2 in the cochlear nuclei of BALB/c mice of different ages

目的探讨年龄相关性听力减退小鼠蜗神经核中甲基化CpG结合蛋白2(MeCP2)的表达差异及临床意义。方法分别取3、6、12、18月龄BALB/c小鼠测定其听性脑干反应阈值,应用半定量逆转录多聚酶链反应方法,检测36、1、2、18月龄鼠蜗神经核中MeCP2的表达。结果 3、6、12月龄鼠8 kHz听阈分别为(24.8±5.1)(、51.5±6.7)和(92.5±7.5)dB SPL,18月龄组120 dB SPL刺激声无诱发反应。MeCP2在各组小鼠蜗神经核中均有表达,随着月龄增加MeCP2呈下降趋势,各组间差异有显著统计学意义(P<0.01)。结论 MeCP2在年龄相关性听力减退小鼠蜗神经核中的表达水平呈增龄相关性降低,可能与蜗神经核的老化及老年性耳聋的发生有关。

Objective To investigate the variance of the methyl-CpG-binding protein 2（MeCP2） expression in the cochlear nuclei of BALB/c mice with age-related hearing loss.Methods The auditory brain stem response（ABR） thresholds in 3,6,12 and 18 month old BLAB/c mice were measured.The expression of MeCP2 mRNA was detected and compared in the cochlear nuclei of BALB/c mice among four age groups（3-,6-,12-and 18-month-old） by reverse transcription polymerase chain reaction（RT-PCR）.Results The ABR thresholds in 3,6 and 12 month old BALB/c mice were（24.8±5.1）,（51.5±6.7） and（92.5±7.5） dB SPL,respectively.In 18 month old group,there were no responses evoked by 120 dB SPL stimular sound.MeCP2 expressed in the cochlear nuclei of BALB/c mice,the mRNA expression of MeCP2 gradually decreased as the age increasing,there was a statistically significant difference between each two groups（P0.01）.Conclusions The decrease of the MeCP2 expression level in the cochlear nuclei is correlated with the degree of aging,which indicates that MeCP2 may take part in the aging of cochlear nuclei,and it may have some relation to presbycusis.